A landscape is the visible features of an area of land , its landforms , and how they integrate with natural or human-made features, often considered in terms of their aesthetic appeal. A landscape includes the physical elements of geophysically defined landforms such as mountains , hills , water bodies such as rivers , lakes , ponds and the sea , living elements of land cover including indigenous vegetation , human elements including different forms of land use , buildings, and structures , and transitory elements such as lighting and weather conditions. Combining both their physical origins and the cultural overlay of human presence, often created over millennia, landscapes reflect a living synthesis of people and place that is vital to local and national identity .
220-523: A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation . About one-third of the land surface of the Earth is arid or semi-arid . This includes much of the polar regions , where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by
440-528: A mammal adapted to desert life. It minimizes its water loss by producing concentrated urine and dry dung , and is able to lose 40% of its body weight through water loss without dying of dehydration. Carnivores can obtain much of their water needs from the body fluids of their prey. Many other hot desert animals are nocturnal , seeking out shade during the day or dwelling underground in burrows. At depths of more than 50 cm (20 in), these remain at between 30 and 32 °C (86 and 90 °F) regardless of
660-452: A sand blasting mechanism which grinds away solid objects in its path as the kinetic energy of the wind is transferred to the ground. The sand eventually ends up deposited in level areas known as sand-fields or sand-seas, or piled up in dunes. Many people think of deserts as consisting of extensive areas of billowing sand dunes because that is the way they are often depicted on TV and in films, but deserts do not always look like this. Across
880-427: A semi-arid climate and are less extreme than regular deserts. Like arid deserts, temperatures can vary greatly in semi deserts. They share some characteristics of a true desert and are usually located at the edge of deserts and continental dry areas. They usually receive precipitation from 250 to 500 mm (9.8 to 19.7 in) but this can vary due to evapotranspiration and soil nutrition. Semi-deserts can be found in
1100-936: A 1,300 m (14,000 sq ft) collector in Coimbatore , India, used for drying marigolds. Solar distillation can be used to make saline or brackish water potable. The first recorded instance of this was by 16th-century Arab alchemists. A large-scale solar distillation project was first constructed in 1872 in the Chilean mining town of Las Salinas. The plant, which had solar collection area of 4,700 m (51,000 sq ft), could produce up to 22,700 L (5,000 imp gal; 6,000 US gal) per day and operate for 40 years. Individual still designs include single-slope, double-slope (or greenhouse type), vertical, conical, inverted absorber, multi-wick, and multiple effect. These stills can operate in passive, active, or hybrid modes. Double-slope stills are
1320-612: A building for better daylighting , selecting materials with favorable thermal mass or light-dispersing properties, and organize spaces that naturally circulate air . In 2011, the International Energy Agency said that "the development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. It will increase countries' energy security through reliance on an indigenous, inexhaustible, and mostly import-independent resource, enhance sustainability , reduce pollution , lower
1540-624: A classic and much-imitated status within the Chinese tradition. Both the Roman and Chinese traditions typically show grand panoramas of imaginary landscapes, generally backed with a range of spectacular mountains – in China often with waterfalls and in Rome often including sea, lakes or rivers. These were frequently used to bridge the gap between a foreground scene with figures and a distant panoramic vista,
1760-535: A conventional steam-generator to produce superheated steam for a turbine/generator as used in any conventional coal, oil, or nuclear power plant. A 100-megawatt turbine would need a tank about 9.1 metres (30 ft) tall and 24 metres (79 ft) in diameter to drive it for four hours by this design. Several parabolic trough power plants in Spain and solar power tower developer SolarReserve use this thermal energy storage concept. The Solana Generating Station in
1980-634: A cooking container. These cookers reach temperatures of 315 °C (599 °F) and above but require direct light to function properly and must be repositioned to track the Sun. Solar concentrating technologies such as parabolic dish, trough and Scheffler reflectors can provide process heat for commercial and industrial applications. The first commercial system was the Solar Total Energy Project (STEP) in Shenandoah, Georgia, US where
2200-649: A cultural group. Culture is the agent, the natural area is the medium, the cultural landscape is the result. A cultural landscape, as defined by the World Heritage Committee , is the "cultural properties [that] represent the combined works of nature and of man." The World Heritage Committee identifies three categories of cultural landscape, ranging from (i) those landscapes most deliberately 'shaped' by people, through (ii) full range of 'combined' works, to (iii) those least evidently 'shaped' by people (yet highly valued). The three categories extracted from
2420-435: A desert conglomerate . In time, bacteria that live on the surface of the stones accumulate a film of minerals and clay particles, forming a shiny brown coating known as desert varnish . Other non-sandy deserts consist of exposed outcrops of bedrock , dry soils or aridisols , and a variety of landforms affected by flowing water , such as alluvial fans , sinks or playas , temporary or permanent lakes , and oases. A hamada
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#17327724641042640-504: A destructive effect on the exposed rocky surfaces. The repeated fluctuations put a strain on exposed rock and the flanks of mountains crack and shatter. Fragmented strata slide down into the valleys where they continue to break into pieces due to the relentless sun by day and chill by night. Successive strata are exposed to further weathering. The relief of the internal pressure that has built up in rocks that have been underground for aeons can cause them to shatter. Exfoliation also occurs when
2860-488: A few miles above Tintern Abbey is an obvious example. More recently, Matthew Arnold 's " The Scholar Gipsy " (1853) praises the Oxfordshire countryside, and W. H. Auden 's " In Praise of Limestone " (1948) uses a limestone landscape as an allegory. Subgenres of topographical poetry include the country house poem , written in 17th-century England to compliment a wealthy patron, and the prospect poem , describing
3080-494: A field of 114 parabolic dishes provided 50% of the process heating, air conditioning and electrical requirements for a clothing factory. This grid-connected cogeneration system provided 400 kW of electricity plus thermal energy in the form of 401 kW steam and 468 kW chilled water and had a one-hour peak load thermal storage. Evaporation ponds are shallow pools that concentrate dissolved solids through evaporation . The use of evaporation ponds to obtain salt from seawater
3300-475: A full-scale steam engine powered by low-pressure water, enabling him to patent the entire solar engine system by 1912. Shuman built the world's first solar thermal power station in Maadi , Egypt , between 1912 and 1913. His plant used parabolic troughs to power a 45–52 kilowatts (60–70 hp ) engine that pumped more than 22,000 litres (4,800 imp gal; 5,800 US gal) of water per minute from
3520-512: A high altitude, where the temperature is low, water vapor condenses into clouds, which rain onto the Earth's surface, completing the water cycle . The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as wind, cyclones and anticyclones . Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14 °C. By photosynthesis , green plants convert solar energy into chemically stored energy, which produces food, wood and
3740-592: A kilometre-wide scale; instead, he defines 'landscape'—regardless of scale—as "the template on which spatial patterns influence ecological processes". Some define 'landscape' as an area containing two or more ecosystems in close proximity. The discipline of landscape science has been described as "bring[ing] landscape ecology and urban ecology together with other disciplines and cross-disciplinary fields to identify patterns and understand social-ecological processes influencing landscape change". A 2000 paper entitled "Geography and landscape science" states that "The whole of
3960-529: A landscape is a heterogeneous land area composed of a cluster of interacting ecosystems that is repeated in similar form throughout, whereby they list woods, meadows, marshes and villages as examples of a landscape's ecosystems, and state that a landscape is an area at least a few kilometres wide. John A. Wiens opposes the traditional view expounded by Carl Troll , Isaak S. Zonneveld, Zev Naveh, Richard T. T. Forman/Michel Godron and others that landscapes are arenas in which humans interact with their environments on
4180-626: A landscape or place. John Denham 's 1642 poem "Cooper's Hill" established the genre, which peaked in popularity in 18th-century England. Examples of topographical verse date, however, to the Late Classical period, and can be found throughout the Medieval era and during the Renaissance . Though the earliest examples come mostly from continental Europe, the topographical poetry in the tradition originating with Denham concerns itself with
4400-497: A landscape or scenery, topographical poetry often, at least implicitly, addresses a political issue or the meaning of nationality in some way. The description of the landscape therefore becomes a poetic vehicle for a political message. For example, in John Denham's "Cooper's Hill", the speaker discusses the merits of the recently executed Charles I . The Vision on Mount Snowdon .................................and on
4620-458: A landscape that brings together multiple stakeholders, who collaborate to integrate policy and practice for their different land use objectives, with the purpose of achieving sustainable landscapes. It recognises that, for example, one river basin can supply water for towns and agriculture, timber and food crops for smallholders and industry, and habitat for biodiversity; the way in which each one of these sectors pursues its goals can have impacts on
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#17327724641044840-405: A landscape was Joseph Addison in 1712. The term landscape architecture was invented by Gilbert Laing Meason in 1828 and was first used as a professional title by Frederick Law Olmsted in 1863. During the latter 19th century, the term landscape architect became used by professional people who designed landscapes. Frederick Law Olmsted used the term 'landscape architecture' as a profession for
5060-572: A large area of sunlight to a hot spot, often to drive a steam turbine . Photovoltaics (PV) were initially solely used as a source of electricity for small and medium-sized applications, from the calculator powered by a single solar cell to remote homes powered by an off-grid rooftop PV system. Commercial concentrated solar power plants were first developed in the 1980s. Since then, as the cost of solar panels has fallen, grid-connected solar PV systems ' capacity and production has doubled about every three years . Three-quarters of new generation capacity
5280-410: A low basal metabolic rate and by remaining underground during the heat of the day, reducing loss of water through its skin and respiratory system when at rest. Herbivorous mammals obtain moisture from the plants they eat. Species such as the addax antelope , dik-dik , Grant's gazelle and oryx are so efficient at doing this that they apparently never need to drink. The camel is a superb example of
5500-457: A marked effect on the degree of aridity and the plant and animal life that can be sustained. Rain falling in the cold season may be more effective at promoting plant growth, and defining the boundaries of deserts and the semiarid regions that surround them on the grounds of precipitation alone is problematic. A semi-arid desert or a steppe is a version of the arid desert with much more rainfall, vegetation and higher humidity. These regions feature
5720-422: A mental construct but as an objectively given 'organic entity', a harmonic individuum of space . Ernst Neef defines landscapes as sections within the uninterrupted earth-wide interconnection of geofactors which are defined as such on the basis of their uniformity in terms of a specific land use, and are thus defined in an anthropocentric and relativistic way. According to Richard Forman and Michael Godron ,
5940-483: A number of ways, generally combining total precipitation, number of days on which this falls, temperature, and humidity, and sometimes additional factors. For example, Phoenix, Arizona , receives less than 250 mm (9.8 in) of precipitation per year, and is immediately recognized as being located in a desert because of its aridity-adapted plants. The North Slope of Alaska's Brooks Range also receives less than 250 mm (9.8 in) of precipitation per year and
6160-575: A persistent problem for landscape artists. A major contrast between landscape painting in the West and East Asia has been that while in the West until the 19th century it occupied a low position in the accepted hierarchy of genres , in East Asia the classic Chinese mountain-water ink painting was traditionally the most prestigious form of visual art. However, in the West, history painting came to require an extensive landscape background where appropriate, so
6380-538: A portion of this energy. Use of solar for heating can roughly be divided into passive solar concepts and active solar concepts, depending on whether active elements such as sun tracking and solar concentrator optics are used. Thermal mass is any material that can be used to store heat—heat from the Sun in the case of solar energy. Common thermal mass materials include stone, cement, and water. Historically they have been used in arid climates or warm temperate regions to keep buildings cool by absorbing solar energy during
6600-514: A reaction against urbanism and industrialisation and a new emphasis on the beauty and value of nature and landscape. However, it was also a revolt against aristocratic social and political norms of the Age of Enlightenment , as well a reaction against the scientific rationalisation of nature. The poet William Wordsworth was a major contributor to the literature of landscape, as was his contemporary poet and novelist Walter Scott . Scott's influence
6820-512: A reference to the energy retained by storing heat before turning it into electricity, versus converting heat directly into electricity. The molten salt mixtures vary. The most extended mixture contains sodium nitrate , potassium nitrate and calcium nitrate . It is non-flammable and non-toxic, and has already been used in the chemical and metals industries as a heat-transport fluid. Hence, experience with such systems exists in non-solar applications. The salt melts at 131 °C (268 °F). It
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7040-468: A series of carefully composed scenes, unrolling like a scroll of landscape paintings. The English landscape garden , also called English landscape park or simply the 'English garden', is a style of parkland garden intended to look as though it might be a natural landscape, although it may be very extensively re-arranged. It emerged in England in the early 18th century, and spread across Europe, replacing
7260-423: A series of long, linear dunes known as seif dunes may form. These also occur parallel to a strong wind that blows in one general direction. Transverse dunes run at a right angle to the prevailing wind direction. Star dunes are formed by variable winds, and have several ridges and slip faces radiating from a central point. They tend to grow vertically; they can reach a height of 500 m (1,600 ft), making them
7480-412: A small part in the near-ultraviolet . Most of the world's population live in areas with insolation levels of 150–300 watts/m , or 3.5–7.0 kWh /m per day. Solar radiation is absorbed by the Earth's land surface, oceans – which cover about 71% of the globe – and atmosphere. Warm air containing evaporated water from the oceans rises, causing atmospheric circulation or convection . When the air reaches
7700-461: A sparse trophic network . Plant growth is limited by rainfall , temperature extremes and desiccating winds. Deserts have strong temporal variability in the availability of resources due to the total amount of annual rainfall and the size of individual rainfall events. Resources are often ephemeral or episodic, and this triggers sporadic animal movements and 'pulse and reserve' or 'boom-bust' ecosystem dynamics. Erosion and sedimentation are high due to
7920-439: A steady wind begins to blow, fine particles lying on the exposed ground begin to vibrate. At greater wind speeds, some particles are lifted into the air stream. When they land, they strike other particles which may be jerked into the air in their turn, starting a chain reaction . Once ejected, these particles move in one of three possible ways, depending on their size, shape and density; suspension , saltation or creep. Suspension
8140-488: A steam engine. In 1908 Shuman formed the Sun Power Company with the intent of building larger solar power plants. He, along with his technical advisor A.S.E. Ackermann and British physicist Sir Charles Vernon Boys , developed an improved system using mirrors to reflect solar energy upon collector boxes, increasing heating capacity to the extent that water could now be used instead of ether. Shuman then constructed
8360-584: A storm that may be many kilometers away. Most deserts are in basins with no drainage to the sea but some are crossed by exotic rivers sourced in mountain ranges or other high rainfall areas beyond their borders. The River Nile , the Colorado River and the Yellow River do this, losing much of their water through evaporation as they pass through the desert and raising groundwater levels nearby. There may also be underground sources of water in deserts in
8580-585: A strong sense of place, but the emphasis is on individual plant forms and human and animal figures rather than the overall landscape setting. For a coherent depiction of a whole landscape, some rough system of perspective, or scaling for distance, is needed, and this seems from literary evidence to have first been developed in Ancient Greece in the Hellenistic period, although no large-scale examples survive. More ancient Roman landscapes survive, from
8800-442: A tenth of their electricity from solar, with China making up more than half of solar growth. Almost half the solar power installed in 2022 was mounted on rooftops . Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated heat is then used as a heat source for a conventional power plant. A wide range of concentrating technologies exists;
9020-485: A tolerable level. In many ways, birds are the ablest to do this of the higher animals. They can move to areas of greater food availability as the desert blooms after local rainfall and can fly to faraway waterholes. In hot deserts, gliding birds can remove themselves from the over-heated desert floor by using thermals to soar in the cooler air at great heights. In order to conserve energy, other desert birds run rather than fly. The cream-colored courser flits gracefully across
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9240-632: A type of cold desert . While they do not lack water, having a persistent cover of snow and ice, this is merely due to marginal evaporation rates and low precipitation. The McMurdo dry valleys of Antarctica, which lack water (whether rain, ice, or snow) much like a non-polar desert and even have such desert features as hypersaline lakes and intermittent streams that resemble (except for being frozen at their surfaces) hot or cold deserts for extreme aridity and lack of precipitation of any kind. Extreme winds and not seasonal heat desiccate these nearly-lifeless terrains. The concept of "biological desert" redefines
9460-405: A vast range of landscapes including the icy landscapes of polar regions , mountainous landscapes, vast arid desert landscapes, islands , and coastal landscapes, densely forested or wooded landscapes including past boreal forests and tropical rainforests and agricultural landscapes of temperate and tropical regions. The activity of modifying the visible features of an area of land
9680-414: A year; they have no annual seasonal cycle of precipitation and experience twelve-month periods with no rainfall at all. Arid deserts receive between 25 and 200 mm (1 and 8 in) in a year and semiarid deserts between 200 and 500 mm (8 and 20 in). However, such factors as the temperature, humidity, rate of evaporation and evapotranspiration, and the moisture storage capacity of the ground have
9900-470: Is 150 km (93 mi) long and is the largest oasis in the Libyan Desert. A lake occupied this depression in ancient times and thick deposits of sandy-clay resulted. Wells are dug to extract water from the porous sandstone that lies underneath. Seepages may occur in the walls of canyons and pools may survive in deep shade near the dried up watercourse below. Lakes may form in basins where there
10120-422: Is a biannual solar-powered car race, where teams from universities and enterprises compete over 3,021 kilometres (1,877 mi) across central Australia from Darwin to Adelaide . In 1987, when it was founded, the winner's average speed was 67 kilometres per hour (42 mph) and by 2007 the winner's average speed had improved to 90.87 kilometres per hour (56.46 mph). The North American Solar Challenge and
10340-439: Is a classic example of passive solar design. The most recent approaches to solar design use computer modeling tying together solar lighting , heating and ventilation systems in an integrated solar design package. Active solar equipment such as pumps, fans, and switchable windows can complement passive design and improve system performance. Urban heat islands (UHI) are metropolitan areas with higher temperatures than that of
10560-537: Is a jumble of eroded sandstone outcrops , canyons , blocks, pinnacles , fissures , slabs and ravines . In some places the wind has carved holes or arches, and in others, it has created mushroom-like pillars narrower at the base than the top. On the Colorado Plateau , it is water that has been the prevailing eroding force. Here, rivers, such as the Colorado , have cut their way over the millennia through
10780-450: Is a passive solar ventilation system composed of a vertical shaft connecting the interior and exterior of a building. As the chimney warms, the air inside is heated, causing an updraft that pulls air through the building. Performance can be improved by using glazing and thermal mass materials in a way that mimics greenhouses. Deciduous trees and plants have been promoted as a means of controlling solar heating and cooling. When planted on
11000-541: Is a type of desert landscape consisting of a high rocky plateau where the sand has been removed by aeolian processes . Other landforms include plains largely covered by gravels and angular boulders, from which the finer particles have been stripped by the wind. These are called "reg" in the western Sahara, "serir" in the eastern Sahara, "gibber plains" in Australia and "saï" in central Asia. The Tassili Plateau in Algeria
11220-409: Is an essential source of renewable energy , and its technologies are broadly characterized as either passive solar or active solar depending on how they capture and distribute solar energy or convert it into solar power. Active solar techniques include the use of photovoltaic systems , concentrated solar power , and solar water heating to harness the energy. Passive solar techniques include designing
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#173277246410411440-403: Is blown away by the wind the stones jiggle themselves into place; alternatively, stones previously below ground may in some way work themselves to the surface. Very little further erosion takes place after the formation of a pavement, and the ground becomes stable. Evaporation brings moisture to the surface by capillary action and calcium salts may be precipitated, binding particles together to form
11660-482: Is causing a loss of cultural identity, as many modern buildings share similar palettes, diluting local characteristics. Researchers have proposed more unified cityscape approaches to address these color landscape issues and help cities preserve their distinctive identities and create vibrant, emotionally engaging urban environments. The word landscape ( landscipe or landscaef ) arrived in England —and therefore into
11880-441: Is challenging; a feasible alternative is hydrogen production from protons, though use of water as the source of electrons (as plants do) requires mastering the multielectron oxidation of two water molecules to molecular oxygen. Some have envisaged working solar fuel plants in coastal metropolitan areas by 2050 – the splitting of seawater providing hydrogen to be run through adjacent fuel-cell electric power plants and
12100-630: Is continuous above 5,600 m (18,400 ft). Nevertheless, there is some plant life in the Atacama, in the form of specialist plants that obtain moisture from dew and the fogs that blow in from the Pacific. When rain falls in deserts, as it occasionally does, it is often with great violence. The desert surface is evidence of this with dry stream channels known as arroyos or wadis meandering across its surface. These can experience flash floods , becoming raging torrents with surprising rapidity after
12320-622: Is found in Australian aboriginal myths (also known as Dreamtime or Dreaming stories, songlines , or Aboriginal oral literature ), the stories traditionally performed by Aboriginal peoples within each of the language groups across Australia. All such myths variously tell significant truths within each Aboriginal group's local landscape . They effectively layer the whole of the Australian continent's topography with cultural nuance and deeper meaning, and empower selected audiences with
12540-763: Is generally limited to the toy market as the surface-area to payload-weight ratio is relatively high. The Squad Solar is a Neighborhood Electric Vehicle that has a solar roof and can be plugged into a normal 120 volt outlet to be charged. Solar chemical processes use solar energy to drive chemical reactions. These processes offset energy that would otherwise come from a fossil fuel source and can also convert solar energy into storable and transportable fuels. Solar induced chemical reactions can be divided into thermochemical or photochemical . A variety of fuels can be produced by artificial photosynthesis . The multielectron catalytic chemistry involved in making carbon-based fuels (such as methanol ) from reduction of carbon dioxide
12760-476: Is higher than that of forests or the sea. A desert is a region of land that is very dry because it receives low amounts of precipitation (usually in the form of rain, but it may be snow, mist or fog), often has little coverage by plants, and in which streams dry up unless they are supplied by water from outside the area. Deserts generally receive less than 250 mm (10 in) of precipitation each year. The potential evapotranspiration may be large but (in
12980-399: Is kept liquid at 288 °C (550 °F) in an insulated "cold" storage tank. The liquid salt is pumped through panels in a solar collector where the focused irradiance heats it to 566 °C (1,051 °F). It is then sent to a hot storage tank. This is so well insulated that the thermal energy can be usefully stored for up to a week. When electricity is needed, the hot salt is pumped to
13200-554: Is often classified as a cold desert. Other regions of the world have cold deserts, including areas of the Himalayas and other high-altitude areas in other parts of the world. Polar deserts cover much of the ice-free areas of the Arctic and Antarctic. A non-technical definition is that deserts are those parts of Earth's surface that have insufficient vegetation cover to support a human population. Potential evapotranspiration supplements
13420-433: Is often less than 40 mm or 1.5 in) to being very far from the nearest available sources of moisture and are often in the lee of mountain ranges. Montane deserts are normally cold, or may be scorchingly hot by day and very cold by night as is true of the northeastern slopes of Mount Kilimanjaro . Polar deserts such as McMurdo Dry Valleys remain ice-free because of the dry katabatic winds that flow downhill from
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#173277246410413640-588: Is one of the oldest applications of solar energy. Modern uses include concentrating brine solutions used in leach mining and removing dissolved solids from waste streams. Clothes lines , clotheshorses , and clothes racks dry clothes through evaporation by wind and sunlight without consuming electricity or gas. In some states of the United States legislation protects the "right to dry" clothes. Unglazed transpired collectors (UTC) are perforated sun-facing walls used for preheating ventilation air. UTCs can raise
13860-420: Is only possible for particles less than 0.1 mm (0.0039 in) in diameter. In a dust storm, these fine particles are lifted up and wafted aloft to heights of up to 6 km (3.7 mi). They reduce visibility and can remain in the atmosphere for days on end, conveyed by the trade winds for distances of up to 6,000 km (3,700 mi). Denser clouds of dust can be formed in stronger winds, moving across
14080-576: Is recommended by the World Health Organization as a viable method for household water treatment and safe storage. Over two million people in developing countries use this method for their daily drinking water. Solar energy may be used in a water stabilization pond to treat waste water without chemicals or electricity. A further environmental advantage is that algae grow in such ponds and consume carbon dioxide in photosynthesis, although algae may produce toxic chemicals that make
14300-432: Is referred to as landscaping . There are several definitions of what constitutes a landscape, depending on context. In common usage however, a landscape refers either to all the visible features of an area of land (usually rural), often considered in terms of aesthetic appeal, or to a pictorial representation of an area of countryside, specifically within the genre of landscape painting . When people deliberately improve
14520-489: Is solar, with both millions of rooftop installations and gigawatt-scale photovoltaic power stations continuing to be built. In 2023, solar power generated 5.5% (1,631 TWh) of global electricity and over 1% of primary energy , adding twice as much new electricity as coal. Along with onshore wind power , utility-scale solar is the source with the cheapest levelised cost of electricity for new installations in most countries. As of 2023, 33 countries generated more than
14740-486: Is sufficient precipitation or meltwater from glaciers above. They are usually shallow and saline, and wind blowing over their surface can cause stress, moving the water over nearby low-lying areas. When the lakes dry up, they leave a crust or hardpan behind. This area of deposited clay, silt or sand is known as a playa . The deserts of North America have more than one hundred playas, many of them relics of Lake Bonneville which covered parts of Utah, Nevada and Idaho during
14960-677: Is the Atacama Desert . It is virtually devoid of life because it is blocked from receiving precipitation by the Andes mountains to the east and the Chilean Coast Range to the west. The cold Humboldt Current and the anticyclone of the Pacific are essential to keep the dry climate of the Atacama. The average precipitation in the Chilean region of Antofagasta is just 1 mm (0.039 in) per year. Some weather stations in
15180-513: Is the box cooker first built by Horace de Saussure in 1767. A basic box cooker consists of an insulated container with a transparent lid. It can be used effectively with partially overcast skies and will typically reach temperatures of 90–150 °C (194–302 °F). Panel cookers use a reflective panel to direct sunlight onto an insulated container and reach temperatures comparable to box cookers. Reflector cookers use various concentrating geometries (dish, trough, Fresnel mirrors) to focus light on
15400-420: Is the dominant application of solar hot water with an installed capacity of 18 GW th as of 2005. In the United States, heating, ventilation and air conditioning (HVAC) systems account for 30% (4.65 EJ/yr) of the energy used in commercial buildings and nearly 50% (10.1 EJ/yr) of the energy used in residential buildings. Solar heating, cooling and ventilation technologies can be used to offset
15620-450: Is the key to plant growth. It can only take place during the day as energy from the sun is required, but during the day, many deserts become very hot. Opening stomata to allow in the carbon dioxide necessary for the process causes evapotranspiration , and conservation of water is a top priority for desert vegetation. Some plants have resolved this problem by adopting crassulacean acid metabolism , allowing them to open their stomata during
15840-425: Is the science of studying and improving relationships between ecological processes in the environment and particular ecosystems. This is done within a variety of landscape scales, development spatial patterns, and organizational levels of research and policy. Landscape is a central concept in landscape ecology. It is, however, defined in quite different ways. For example: Carl Troll conceives of landscape not as
16060-429: Is the specializations of mammalian kidneys shown by desert-inhabiting species. Many examples of convergent evolution have been identified in desert organisms, including between cacti and Euphorbia , kangaroo rats and jerboas , Phrynosoma and Moloch lizards. Deserts present a very challenging environment for animals. Not only do they require food and water but they also need to keep their body temperature at
16280-527: Is very cold and carries little moisture so little precipitation occurs and what does fall, usually snow, is carried along in the often strong wind and may form blizzards, drifts and dunes similar to those caused by dust and sand in other desert regions. In Antarctica , for example, the annual precipitation is about 50 mm (2 in) on the central plateau and some ten times that amount on some major peninsulas. Based on precipitation alone, hyperarid deserts receive less than 25 mm (1 in) of rainfall
16500-726: The Gossamer Penguin made the first piloted flights powered solely by photovoltaics. This was quickly followed by the Solar Challenger which crossed the English Channel in July 1981. In 1990 Eric Scott Raymond in 21 hops flew from California to North Carolina using solar power. Developments then turned back to unmanned aerial vehicles (UAV) with the Pathfinder (1997) and subsequent designs, culminating in
16720-460: The Helios which set the altitude record for a non-rocket-propelled aircraft at 29,524 metres (96,864 ft) in 2001. The Zephyr , developed by BAE Systems , is the latest in a line of record-breaking solar aircraft, making a 54-hour flight in 2007, and month-long flights were envisioned by 2010. From March 2015 to July 2016, Solar Impulse , an electric aircraft , successfully circumnavigated
16940-693: The Atacama Desert . Deserts of this type are often long and narrow and bounded to the east by mountain ranges. They occur in Namibia , Chile , southern California and Baja California . Other coastal deserts influenced by cold currents are found in Western Australia , the Arabian Peninsula and Horn of Africa , and the western fringes of the Sahara. In 1961, Peveril Meigs divided desert regions on Earth into three categories according to
17160-535: The English language —after the fifth century, following the arrival of the Anglo-Saxons ; these terms referred to a system of human-made spaces on the land. The term landscape emerged around the turn of the sixteenth century to denote a painting whose primary subject matter was natural scenery. Land (a word from Germanic origin) may be taken in its sense of something to which people belong (as in England being
17380-488: The Nile River to adjacent cotton fields. Although the outbreak of World War I and the discovery of cheap oil in the 1930s discouraged the advancement of solar energy, Shuman's vision, and basic design were resurrected in the 1970s with a new wave of interest in solar thermal energy. In 1916 Shuman was quoted in the media advocating solar energy's utilization, saying: We have proved the commercial profit of sun power in
17600-562: The Urlandschaft (transl. original landscape) or landscape that existed before major human induced changes and the Kulturlandschaft (transl. 'cultural landscape') a landscape created by human culture. The major task of geography was to trace the changes in these two landscapes. It was Carl O. Sauer , a human geographer , who was probably the most influential in promoting and developing the idea of cultural landscapes. Sauer
17820-462: The biomass from which fossil fuels are derived. The total solar energy absorbed by Earth's atmosphere, oceans and land masses is approximately 122 PW·year = 3,850,000 exajoules (EJ) per year. In 2002 (2019), this was more energy in one hour (one hour and 25 minutes) than the world used in one year. Photosynthesis captures approximately 3,000 EJ per year in biomass. The potential solar energy that could be used by humans differs from
18040-741: The fine arts , architecture , industrial design , geology and the earth sciences , environmental psychology , geography , and ecology . The activities of a landscape architect can range from the creation of public parks and parkways to site planning for campuses and corporate office parks, from the design of residential estates to the design of civil infrastructure and the management of large wilderness areas or reclamation of degraded landscapes such as mines or landfills . Landscape architects work on all types of structures and external space – large or small, urban , suburban and rural , and with "hard" (built) and "soft" (planted) materials, while paying attention to ecological sustainability . For
18260-620: The horse latitudes at 30° to 35° North and South. These belts are associated with the subtropical anticyclone and the large-scale descent of dry air. The Sahara Desert is of this type. Mid-latitude deserts occur between 30° and 50° North and South. They are mostly in areas remote from the sea where most of the moisture has already precipitated from the prevailing winds. They include the Tengger and Sonoran Deserts . Monsoon deserts are similar. They occur in regions where large temperature differences occur between sea and land. Moist warm air rises over
18480-415: The windward slope of the mountain range . When they descend on the leeward side, they warm and their capacity to hold moisture increases so an area with relatively little precipitation occurs. The Taklamakan Desert is an example, lying in the rain shadow of the Himalayas and receiving less than 38 mm (1.5 in) precipitation annually. Other areas are arid by virtue of being a very long way from
18700-627: The 16th through the 20th centuries—from Edmund Spenser to Sylvia Plath —correspondent to each type, from "Walks and Surveys", to "Mountains, Hills, and the View from Above", to "Violation of Nature and the Landscape", to "Spirits and Ghosts." Common aesthetic registers of which topographical poetry makes use include pastoral imagery, the sublime , and the picturesque , which include images of rivers, ruins, moonlight, birdsong, and clouds, peasants, mountains, caves, and waterscapes. Though describing
18920-464: The 1st century BCE onwards, especially frescos of landscapes decorating rooms that have been preserved at archaeological sites of Pompeii , Herculaneum and elsewhere, and mosaics . The Chinese ink painting tradition of shan shui ("mountain-water"), or "pure" landscape, in which the only sign of human life is usually a sage, or a glimpse of his hut, uses sophisticated landscape backgrounds to figure subjects, and landscape art of this period retains
19140-467: The Anglo-Chinese garden, and the philosophy of Jean-Jacques Rousseau (1712 – 1778). The English garden usually included a lake, sweeps of gently rolling lawns set against groves of trees, and recreations of classical temples, Gothic ruins, bridges, and other picturesque architecture, designed to recreate an idyllic pastoral landscape. The work of Lancelot "Capability" Brown and Humphry Repton
19360-492: The Atacama have never received rain. Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971. It is so arid that mountains that reach as high as 6,885 m (22,589 ft) are completely free of glaciers and, in the southern part from 25°S to 27°S, may have been glacier-free throughout the Quaternary , though permafrost extends down to an altitude of 4,400 m (14,400 ft) and
19580-554: The Cerro Dominador plant is capable of generating around 110 MW of power. The plant has an advanced storage system enabling it to generate electricity for up to 17.5 hours without direct solar radiation, which allows it to provide a stable electricity supply without interruptions if required. The Project secured up to 950 GW·h per year sale. Another project is the María Elena plant is a 400 MW thermo-solar complex in
19800-550: The Committee's Operational Guidelines, are as follows: The Chinese garden is a landscape garden style which has evolved over three thousand years. It includes both the vast gardens of the Chinese emperors and members of the Imperial Family, built for pleasure and to impress, and the more intimate gardens created by scholars, poets, former government officials, soldiers and merchants, made for reflection and escape from
20020-557: The Earth's surface and the general being that which can be seen by an observer. An example of this second usage can be found as early as 1662 in the Book of Common Prayer : There are several words that are frequently associated with the word landscape: Geomorphology is the scientific study of the origin and evolution of topographic and bathymetric features created by physical or chemical processes operating at or near Earth's surface. Geomorphologists seek to understand why landscapes look
20240-482: The English landscape found in the works of John Constable , J. M. W. Turner and Samuel Palmer . However all these had difficulty establishing themselves in the contemporary art market, which still preferred history paintings and portraits. In Europe, as John Ruskin said, and Sir Kenneth Clark confirmed, landscape painting was the "chief artistic creation of the nineteenth century", and "the dominant art", with
20460-504: The Equator-facing side of a building because they will interfere with winter solar availability. They can, however, be used on the east and west sides to provide a degree of summer shading without appreciably affecting winter solar gain . Solar cookers use sunlight for cooking, drying, and pasteurization . They can be grouped into three broad categories: box cookers, panel cookers, and reflector cookers. The simplest solar cooker
20680-571: The Origin of Our Ideas of the Sublime and Beautiful (1757) was also an influential text, as was Longinus ' On the Sublime (early A.D., Greece), which was translated into English from the French in 1739. From the 18th century, a taste for the sublime in the natural landscape emerged alongside the idea of the sublime in language; that is elevated rhetoric or speech. A topographical poem that influenced
20900-488: The Roman emperor Tiberius . The first modern greenhouses were built in Europe in the 16th century to keep exotic plants brought back from explorations abroad. Greenhouses remain an important part of horticulture today. Plastic transparent materials have also been used to similar effect in polytunnels and row covers . Development of a solar-powered car has been an engineering goal since the 1980s. The World Solar Challenge
21120-569: The Romantics, was James Thomson 's The Seasons (1726–30). The changing landscape, brought about by the industrial and agricultural revolutions , with the expansion of the city and depopulation of the countryside, was another influences on the growth of the Romantic movement in Britain. The poor condition of workers, the new class conflicts, and the pollution of the environment all led to
21340-499: The Sun. Active solar techniques use photovoltaics, concentrated solar power , solar thermal collectors , pumps, and fans to convert sunlight into useful output. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce
21560-462: The U.S. has six hours of storage by molten salt. In Chile, The Cerro Dominador power plant has a 110 MW solar-thermal tower, the heat is transferred to molten salts . The molten salts then transfer their heat in a heat exchanger to water, generating superheated steam, which feeds a turbine that transforms the kinetic energy of the steam into electric energy using the Rankine cycle . In this way,
21780-657: The Universal Exposition in Paris, Augustin Mouchot successfully demonstrated a solar steam engine but could not continue development because of cheap coal and other factors. In 1897, Frank Shuman , a US inventor, engineer and solar energy pioneer built a small demonstration solar engine that worked by reflecting solar energy onto square boxes filled with ether, which has a lower boiling point than water and were fitted internally with black pipes which in turn powered
22000-528: The absence of available water) the actual evapotranspiration may be close to zero. Semi-deserts are regions which receive between 250 and 500 mm (10 and 20 in) and when clad in grass, these are known as steppes . Most deserts on Earth such as the Sahara Desert , Grand Australian Desert and the Great Basin Desert , occur in low altitudes . One of the driest places on Earth
22220-460: The accumulated wisdom and knowledge of Australian Aboriginal ancestors back to time immemorial . In the West pastoral poetry represent the earliest form of landscape literature, though this literary genre presents an idealized landscape peopled by shepherds and shepherdesses, and creates "an image of a peaceful uncorrupted existence; a kind of prelapsarian world". The pastoral has its origins in
22440-675: The aesthetic appearance of a piece of land—by changing contours and vegetation, etc.—it is said to have been landscaped , though the result may not constitute a landscape according to some definitions. Color landscapes blend artificial elements like buildings, roads, and pavements with natural features such as mountains, forests, plants, sky, and rivers. These compositions of distant and near views can significantly impact people's emotions. As urbanization rapidly advances, urban color landscape design has become essential for cities to differentiate and symbolize their unique character and atmosphere. However, this transformation has created challenges. First,
22660-400: The air but soon fall back to earth, ejecting other particles in the process. Their weight prevents them from being airborne for long and most only travel a distance of a few meters (yards). The sand streams along above the surface of the ground like a fluid, often rising to heights of about 30 cm (12 in). In a really severe steady blow, 2 m (6 ft 7 in) is about as high as
22880-472: The amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location. Deserts are formed by weathering processes as large variations in temperature between day and night put strains on the rocks , which consequently break in pieces. Although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter, and
23100-720: The amount of precipitation they received. In this now widely accepted system, extremely arid lands have at least twelve consecutive months without precipitation, arid lands have less than 250 mm (9.8 in) of annual precipitation, and semiarid lands have a mean annual precipitation of between 250 and 500 mm (9.8 and 19.7 in). Both extremely arid and arid lands are considered to be deserts while semiarid lands are generally referred to as steppes when they are grasslands. Deserts are also classified, according to their geographical location and dominant weather pattern, as trade wind, mid-latitude, rain shadow, coastal, monsoon, or polar deserts . Trade wind deserts occur either side of
23320-420: The amount of solar energy present near the surface of the planet because factors such as geography, time variation, cloud cover, and the land available to humans limit the amount of solar energy that we can acquire. In 2021, Carbon Tracker Initiative estimated the land area needed to generate all our energy from solar alone was 450,000 km — or about the same as the area of Sweden , or the area of Morocco , or
23540-596: The area of California (0.3% of the Earth's total land area). Solar technologies are categorized as either passive or active depending on the way they capture, convert and distribute sunlight and enable solar energy to be harnessed at different levels around the world, mostly depending on the distance from the Equator. Although solar energy refers primarily to the use of solar radiation for practical ends, all types of renewable energy, other than geothermal power and tidal power , are derived either directly or indirectly from
23760-411: The barren rock is to be found in the so-called Dry Valleys of Antarctica that almost never get snow, which can have ice-encrusted saline lakes that suggest evaporation far greater than the rare snowfall due to the strong katabatic winds that even evaporate ice. Deserts, both hot and cold, play a part in moderating Earth's temperature, because they reflect more of the incoming light and their albedo
23980-456: The capture of large quantities of solar energy . English desert and its Romance cognates (including Italian and Portuguese deserto , French désert and Spanish desierto ) all come from the ecclesiastical Latin dēsertum (originally "an abandoned place"), a participle of dēserere , "to abandon". The correlation between aridity and sparse population is complex and dynamic, varying by culture, era, and technologies; thus
24200-545: The capture of solar energy to optimize the productivity of plants. Techniques such as timed planting cycles, tailored row orientation, staggered heights between rows and the mixing of plant varieties can improve crop yields. While sunlight is generally considered a plentiful resource, the exceptions highlight the importance of solar energy to agriculture. During the short growing seasons of the Little Ice Age , French and English farmers employed fruit walls to maximize
24420-522: The cellular structure of which has been modified to allow them to store water. When rain falls, the water is rapidly absorbed by the shallow roots and retained to allow them to survive until the next downpour, which may be months or years away. The giant saguaro cacti of the Sonoran Desert form "forests", providing shade for other plants and nesting places for desert birds. Saguaro grows slowly but may live for up to two hundred years. The surface of
24640-455: The classics, and many of the various types of topographical verse, such as river, ruin, or hilltop poems were established by the early 17th century. Alexander Pope 's "Windsor Forest" (1713) and John Dyer 's " Grongar Hill ' (1762) are two other familiar examples. George Crabbe , the Suffolk regional poet, also wrote topographical poems, as did William Wordsworth , of which Lines written
24860-613: The coldest part of the year. Animals adapted to live in deserts are called xerocoles . There is no evidence that body temperature of mammals and birds is adaptive to the different climates, either of great heat or cold. In fact, with a very few exceptions, their basal metabolic rate is determined by body size, irrespective of the climate in which they live. Many desert animals (and plants) show especially clear evolutionary adaptations for water conservation or heat tolerance and so are often studied in comparative physiology , ecophysiology , and evolutionary physiology . One well-studied example
25080-551: The collection of solar energy. These walls acted as thermal masses and accelerated ripening by keeping plants warm. Early fruit walls were built perpendicular to the ground and facing south, but over time, sloping walls were developed to make better use of sunlight. In 1699, Nicolas Fatio de Duillier even suggested using a tracking mechanism which could pivot to follow the Sun. Applications of solar energy in agriculture aside from growing crops include pumping water, drying crops, brooding chicks and drying chicken manure. More recently
25300-595: The collision between airborne particles and by the impacts of saltating sand grains landing on the ground. The mechanism is little understood but the particles usually have a negative charge when their diameter is under 250 μm and a positive one when they are over 500 μm. Deserts and semi-deserts are home to ecosystems with low or very low biomass and primary productivity in arid or semi-arid climates. They are mostly found in subtropical high-pressure belts and major continental rain shadows . Primary productivity depends on low densities of small photoautotrophs that sustain
25520-582: The color of the underlying surface. The desert lark takes frequent dust baths which ensures that it matches its environment. Water and carbon dioxide are metabolic end products of oxidation of fats, proteins, and carbohydrates. Oxidising a gram of carbohydrate produces 0.60 grams of water; a gram of protein produces 0.41 grams of water; and a gram of fat produces 1.07 grams of water, making it possible for xerocoles to live with little or no access to drinking water. The kangaroo rat for example makes use of this water of metabolism and conserves water both by having
25740-465: The concept of desert, without the characteristic of aridity, not lacking water, but instead lacking life. Such places can be so-called "ocean deserts", which are mostly at the centers of gyres , but also hypoxic or anoxic waters such as dead zones . Deserts usually have a large diurnal and seasonal temperature range, with high daytime temperatures falling sharply at night. The diurnal range may be as much as 20 to 30 °C (36 to 54 °F) and
25960-434: The costs of mitigating global warming .... these advantages are global". The Earth receives 174 petawatts (PW) of incoming solar radiation ( insolation ) at the upper atmosphere . Approximately 30% is reflected back to space while the rest, 122 PW, is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with
26180-479: The day and radiating stored heat to the cooler atmosphere at night. However, they can be used in cold temperate areas to maintain warmth as well. The size and placement of thermal mass depend on several factors such as climate, daylighting, and shading conditions. When duly incorporated, thermal mass maintains space temperatures in a comfortable range and reduces the need for auxiliary heating and cooling equipment. A solar chimney (or thermal chimney, in this context)
26400-507: The desert floor to scarify the seed coat. The seed of the mesquite tree, which grows in deserts in the Americas, is hard and fails to sprout even when planted carefully. When it has passed through the gut of a pronghorn it germinates readily, and the little pile of moist dung provides an excellent start to life well away from the parent tree. The stems and leaves of some plants lower the surface velocity of sand-carrying winds and protect
26620-500: The desert need special adaptations to survive in the harsh environment. Plants tend to be tough and wiry with small or no leaves, water-resistant cuticles , and often spines to deter herbivory . Some annual plants germinate , bloom and die in the course of a few weeks after rainfall, while other long-lived plants survive for years and have deep root systems able to tap underground moisture. Animals need to keep cool and find enough food and water to survive. Many are nocturnal , and stay in
26840-620: The development of extremely subtle realist techniques for depicting light and weather. The popularity of landscapes in the Netherlands was in part a reflection of the virtual disappearance of religious painting in a Calvinist society, and the decline of religious painting in the 18th and 19th centuries all over Europe combined with Romanticism to give landscapes a much greater and more prestigious place in 19th-century art than they had assumed before. In England, landscapes had initially been mostly backgrounds to portraits, typically suggesting
27060-620: The disciplines involved in landscape research will be referred to as landscape science, although this term was used first in 1885 by the geographers Oppel and Troll". A 2013 guest editorial defines landscape science as "research that seeks to understand the relationship between people and their environment, with a focus on land use change and data pertaining to land resources at the landscape scale". The Great Soviet Encyclopedia of 1979 defines landscape science as "the branch of physical geography that deals with natural territorial complexes (or geographic complexes, geosystems) as structural parts of
27280-583: The driest season, and others curl their leaves up to reduce transpiration. Others, such as aloes , store water in succulent leaves or stems or in fleshy tubers. Desert plants maximize water uptake by having shallow roots that spread widely, or by developing long taproots that reach down to deep rock strata for ground water. The saltbush in Australia has succulent leaves and secretes salt crystals, enabling it to live in saline areas. In common with cacti, many have developed spines to ward off browsing animals. Some desert plants produce seed which lies dormant in
27500-434: The earth's geographic mantle" and states that "The basis of landscape science is the theory that the geographic landscape is the primary element in the physicogeo-graphical differentiation of the earth. Landscape science deals with the origin, structure, and dynamics of landscapes, the laws of the development and arrangement of landscapes, and the transformation of landscapes by the economic activity of man.", and asserts that it
27720-453: The external temperature. Jerboas , desert rats , kangaroo rats and other small rodents emerge from their burrows at night and so do the foxes, coyotes, jackals and snakes that prey on them. Kangaroos keep cool by increasing their respiration rate, panting, sweating and moistening the skin of their forelegs with saliva . Mammals living in cold deserts have developed greater insulation through warmer body fur and insulating layers of fat beneath
27940-414: The field. The surface of Earth is modified by a combination of surface processes that sculpt landscapes, and geologic processes that cause tectonic uplift and subsidence , and shape the coastal geography . Surface processes comprise the action of water , wind , ice , fire , and living things on the surface of the Earth, along with chemical reactions that form soils and alter material properties,
28160-458: The fine glass surfaces of solar power plants. Metal grills would allow a high percentage of sunlight to enter the mirrors and solar panels while also preventing most damage. Sunlight has influenced building design since the beginning of architectural history. Advanced solar architecture and urban planning methods were first employed by the Greeks and Chinese , who oriented their buildings toward
28380-521: The fine material has been blown away and the surface consists of a mosaic of smooth stones, often forming desert pavements , and little further erosion takes place. Other desert features include rock outcrops , exposed bedrock and clays once deposited by flowing water. Temporary lakes may form and salt pans may be left when waters evaporate. There may be underground sources of water, in the form of springs and seepages from aquifers . Where these are found, oases can occur. Plants and animals living in
28600-700: The first great poet associated with the Fields and Gardens poetry genre. Many landscape photographs show little or no human activity and are created in the pursuit of a pure, unsullied depiction of nature devoid of human influence, instead featuring subjects such as strongly defined landforms, weather, and ambient light. As with most forms of art, the definition of a landscape photograph is broad, and may include urban settings, industrial areas, and nature photography . Notable landscape photographers include Ansel Adams , Galen Rowell , Edward Weston , Ben Heine , Mark Gray and Fred Judge . The earliest forms of art around
28820-728: The first solar-powered crossing of the Pacific Ocean, and the Sun21 catamaran made the first solar-powered crossing of the Atlantic Ocean in the winter of 2006–2007. There were plans to circumnavigate the globe in 2010. In 1974, the unmanned AstroFlight Sunrise airplane made the first solar flight. On 29 April 1979, the Solar Riser made the first flight in a solar-powered, fully controlled, man-carrying flying machine, reaching an altitude of 40 ft (12 m). In 1980,
29040-495: The first time when designing Central Park , New York City , US. Here the combination of traditional landscape gardening and the emerging field of city planning gave landscape architecture its unique focus. This use of the term landscape architect became established after Frederick Law Olmsted Jr. and others founded the American Society of Landscape Architects (ASLA) in 1899. Possibly the earliest landscape literature
29260-593: The focus of the Sustainable Development Goals . Integrated landscape management is increasingly taken up at the national, local and international level, for example the UN Environment Programme states that "UNEP champions the landscape approach de facto as it embodies the main elements of integrated ecosystem management ". Landscape archaeology or landscape history is the study of the way in which humanity has changed
29480-570: The form of springs , aquifers , underground rivers or lakes. Where these lie close to the surface, wells can be dug and oases may form where plant and animal life can flourish. The Nubian Sandstone Aquifer System under the Sahara Desert is the largest known accumulation of fossil water . The Great Man-Made River is a scheme launched by Libya's Muammar Gaddafi to tap this aquifer and supply water to coastal cities. Kharga Oasis in Egypt
29700-551: The formation of deep sedimentary basins where the surface of Earth drops and is filled with material eroded from other parts of the landscape. The Earth surface and its topography therefore are an intersection of climatic, hydrologic , and biologic action with geologic processes. Desert , Plain , Taiga , Tundra , Wetland , Mountain , Mountain range , Cliff , Coast , Littoral zone , Glacier , Polar regions of Earth , Shrubland , Forest , Rainforest , Woodland , Jungle , Moors , Steppe , Valley . Landscape ecology
29920-456: The fragmentation of harder granites , limestone and sandstone . There is a certain critical size (about 0.5 mm) below which further temperature-induced weathering of rocks does not occur and this provides a minimum size for sand grains. As the mountains are eroded, more and more sand is created. At high wind speeds, sand grains are picked up off the surface and blown along, a process known as saltation . The whirling airborne grains act as
30140-476: The globe. It is a single-seat plane powered by solar cells and capable of taking off under its own power. The design allows the aircraft to remain airborne for several days. A solar balloon is a black balloon that is filled with ordinary air. As sunlight shines on the balloon, the air inside is heated and expands, causing an upward buoyancy force, much like an artificially heated hot air balloon . Some solar balloons are large enough for human flight, but usage
30360-439: The ground from erosion. Even small fungi and microscopic plant organisms found on the soil surface (so-called cryptobiotic soil ) can be a vital link in preventing erosion and providing support for other living organisms. Cold deserts often have high concentrations of salt in the soil. Grasses and low shrubs are the dominant vegetation here and the ground may be covered with lichens . Most shrubs have spiny leaves and shed them in
30580-432: The ground on its long legs, stopping periodically to snatch up insects. Like other desert birds, it is well-camouflaged by its coloring and can merge into the landscape when stationary. The sandgrouse is an expert at this and nests on the open desert floor dozens of kilometers (miles) away from the waterhole it needs to visit daily. Some small diurnal birds are found in very restricted localities where their plumage matches
30800-426: The ground rises quickly through a small pocket of cooler, low-pressure air above forming a whirling column of particles, a dust devil . Sandstorms occur with much less frequency than dust storms. They are often preceded by severe dust storms and occur when the wind velocity increases to a point where it can lift heavier particles. These grains of sand, up to about 0.5 mm (0.020 in) in diameter are jerked into
31020-493: The gypsum and forming crystals known as selenite . The crystals left behind by this process are eroded by the wind and deposited as vast white dune fields that resemble snow-covered landscapes. These types of dune are rare, and only form in closed arid basins that retain the highly soluble gypsum that would otherwise be washed into the sea. A large part of the surface area of the world's deserts consists of flat, stone-covered plains dominated by wind erosion. In " eolian deflation ",
31240-428: The high desert floor, creating canyons that are over a mile (6,000 feet or 1,800 meters) deep in places, exposing strata that are over two billion years old. Sand and dust storms are natural events that occur in arid regions where the land is not protected by a covering of vegetation. Dust storms usually start in desert margins rather than the deserts themselves where the finer materials have already been blown away. As
31460-782: The high elevations of the Tabernas Desert (and some parts of the Spanish Plateu ), The Sahel , The Eurasian Steppe , most of Central Asia , the Western US , most of Northern Mexico , portions of South America (especially in Argentina ) and the Australian Outback . They usually feature BSh (hot steppe) or BSk (temperate steppe) in the Köppen climate classification . Coastal deserts are mostly found on
31680-454: The import of water from an outside source. Many trade routes have been forged across deserts, especially across the Sahara , and traditionally were used by caravans of camels carrying salt, gold, ivory and other goods. Large numbers of slaves were also taken northwards across the Sahara. Some mineral extraction also takes place in deserts, and the uninterrupted sunlight gives potential for
31900-581: The incoming air temperature up to 22 °C (40 °F) and deliver outlet temperatures of 45–60 °C (113–140 °F). The short payback period of transpired collectors (3 to 12 years) makes them a more cost-effective alternative than glazed collection systems. As of 2003, over 80 systems with a combined collector area of 35,000 square metres (380,000 sq ft) had been installed worldwide, including an 860 m (9,300 sq ft) collector in Costa Rica used for drying coffee beans and
32120-521: The lack of heat to aid in the evaporation process. Deserts are sometimes classified as "hot" or "cold", "semiarid" or "coastal". The characteristics of hot deserts include high temperatures in summer; greater evaporation than precipitation, usually exacerbated by high temperatures, strong winds and lack of cloud cover; considerable variation in the occurrence of precipitation, its intensity and distribution; and low humidity. Winter temperatures vary considerably between different deserts and are often related to
32340-454: The land of the English). The suffix -scape is equivalent to the more common English suffix -ship. The roots of -ship are etymologically akin to Old English sceppan or scyppan , meaning to shape . The suffix -schaft is related to the verb schaffen , so that -ship and shape are also etymologically linked. The modern form of the word, with its connotations of scenery, appeared in
32560-428: The land with a billowing leading edge. The sunlight can be obliterated and it may become as dark as night at ground level. In a study of a dust storm in China in 2001, it was estimated that 6.5 million tons of dust were involved, covering an area of 134,000,000 km (52,000,000 sq mi). The mean particle size was 1.44 μm. A much smaller scale, short-lived phenomenon can occur in calm conditions when hot air near
32780-475: The land, deposits its water content and circulates back to sea. Further inland, areas receive very little precipitation. The Thar Desert near the India/Pakistan border is of this type. In some parts of the world, deserts are created by a rain shadow effect. Orographic lift occurs as air masses rise to pass over high ground. In the process they cool and lose much of their moisture by precipitation on
33000-721: The last ice age when the climate was colder and wetter. These include the Great Salt Lake , Utah Lake , Sevier Lake and many dry lake beds. The smooth flat surfaces of playas have been used for attempted vehicle speed records at Black Rock Desert and Bonneville Speedway and the United States Air Force uses Rogers Dry Lake in the Mojave Desert as runways for aircraft and the Space Shuttle . Deserts have been defined and classified in
33220-408: The late sixteenth century when the term landschap was introduced by Dutch painters who used it to refer to paintings of inland natural or rural scenery. The word landscape , first recorded in 1598, was borrowed from a Dutch painters' term. The popular conception of the landscape that is reflected in dictionaries conveys both a particular and a general meaning, the particular referring to an area of
33440-509: The life processes of plants. Potential evapotranspiration , then, is the amount of water that could evaporate in any given region. As an example, Tucson, Arizona receives about 300 mm (12 in) of rain per year, however about 2,500 mm (98 in) of water could evaporate over the course of a year. In other words, about eight times more water could evaporate from the region than actually falls as rain. Rates of evapotranspiration in cold regions such as Alaska are much lower because of
33660-411: The location of the desert on the continental landmass and the latitude. Daily variations in temperature can be as great as 22 °C (40 °F) or more, with heat loss by radiation at night being increased by the clear skies. Cold deserts, sometimes known as temperate deserts, occur at higher latitudes than hot deserts, and the aridity is caused by the dryness of the air. Some cold deserts are far from
33880-404: The measurement of precipitation in providing a scientific measurement-based definition of a desert. The water budget of an area can be calculated using the formula P − PE ± S , wherein P is precipitation, PE is potential evapotranspiration rates and S is the amount of surface storage of water. Evapotranspiration is the combination of water loss through atmospheric evaporation and through
34100-508: The more formal, symmetrical jardin à la française of the 17th century as the principal style for large parks and gardens in Europe. The English garden (and later French landscape garden ) presented an idealized view of nature. It drew inspiration from paintings of landscapes by Claude Lorraine and Nicolas Poussin , and from the classic Chinese gardens of the East, which had recently been described by European travellers and were realized in
34320-512: The most developed are the parabolic trough, the solar tower collectors, the concentrating linear Fresnel reflector, and the Stirling dish. Various techniques are used to track the Sun and focus light. In all of these systems, a working fluid is heated by the concentrated sunlight, and is then used for power generation or energy storage. Designs need to account for the risk of a dust storm , hail , or another extreme weather event that can damage
34540-422: The most economical for decentralized domestic purposes, while active multiple effect units are more suitable for large-scale applications. Solar water disinfection (SODIS) involves exposing water-filled plastic polyethylene terephthalate (PET) bottles to sunlight for several hours. Exposure times vary depending on weather and climate from a minimum of six hours to two days during fully overcast conditions. It
34760-616: The nearest available sources of moisture. Montane deserts are arid places with a very high altitude ; the most prominent example is found north of the Himalayas, in the Kunlun Mountains and the Tibetan Plateau . Many locations within this category have elevations exceeding 3,000 m (9,800 ft) and the thermal regime can be hemiboreal . These places owe their profound aridity (the average annual precipitation
34980-508: The need for alternative resources and are generally considered demand-side technologies. In 2000, the United Nations Development Programme , UN Department of Economic and Social Affairs, and World Energy Council published an estimate of the potential solar energy that could be used by humans each year. This took into account factors such as insolation, cloud cover, and the land that is usable by humans. It
35200-407: The night to allow CO 2 to enter, and close them during the day, or by using C4 carbon fixation . Many desert plants have reduced the size of their leaves or abandoned them altogether. Cacti are present in both North and South America with a post-Gondwana origin. The genus is desert specialist, and in most species, the leaves have been dispensed with and the chlorophyll displaced into the trunks,
35420-471: The northern Chilean region of Antofagasta employing molten salt technology. Solar power , also known as solar electricity, is the conversion of energy from sunlight into electricity , either directly using photovoltaics (PV) or indirectly using concentrated solar power . Solar panels use the photovoltaic effect to convert light into an electric current . Concentrated solar power systems use lenses or mirrors and solar tracking systems to focus
35640-526: The ocean and others are separated by mountain ranges from the sea, and in both cases, there is insufficient moisture in the air to cause much precipitation. The largest of these deserts are found in Central Asia. Others occur on the eastern side of the Rocky Mountains , the eastern side of the southern Andes and in southern Australia. Polar deserts are a particular class of cold desert. The air
35860-423: The others. The intention is to minimise conflict between these different land use objectives and ecosystem services . This approach draws on landscape ecology, as well as many related fields that also seek to integrate different land uses and users, such as watershed management . Proponents of integrated landscape management argue that it is well-suited to address complex global challenges, such as those that are
36080-425: The outer surfaces of rocks split off in flat flakes. This is believed to be caused by the stresses put on the rock by repeated thermal expansions and contractions which induces fracturing parallel to the original surface. Chemical weathering processes probably play a more important role in deserts than was previously thought. The necessary moisture may be present in the form of dew or mist. Ground water may be drawn to
36300-429: The outside world. They create an idealized miniature landscape, which is meant to express the harmony that should exist between man and nature. A typical Chinese garden is enclosed by walls and includes one or more ponds, scholar's rocks , trees and flowers, and an assortment of halls and pavilions within the garden, connected by winding paths and zig-zag galleries. By moving from structure to structure, visitors can view
36520-464: The parks or estates of a landowner, though mostly painted in London by an artist who had never visited the site. the English tradition was founded by Anthony van Dyck and other, mostly Flemish , artists working in England. By the beginning of the 19th century the English artists with the highest modern reputations were mostly dedicated landscapists, showing the wide range of Romantic interpretations of
36740-463: The people in their paintings to figures subsumed within broader, regionally specific landscapes. The geographer Otto Schlüter is credited with having first formally used "cultural landscape" as an academic term in the early 20th century. In 1908, Schlüter argued that by defining geography as a Landschaftskunde (landscape science) this would give geography a logical subject matter shared by no other discipline. He defined two forms of landscape:
36960-479: The period before 1800, the history of landscape gardening (later called landscape architecture) is largely that of master planning and garden design for manor houses , palaces and royal properties, religious complexes, and centers of government. An example is the extensive work by André Le Nôtre at Vaux-le-Vicomte and at the Palace of Versailles for King Louis XIV of France . The first person to write of making
37180-515: The physical appearance of the environment - both present and past. Landscape generally refers to both natural environments and environments constructed by human beings. Natural landscapes are considered to be environments that have not been altered by humans in any shape or form. Cultural landscapes , on the other hand, are environments that have been altered in some manner by people (including temporary structures and places, such as campsites, that are created by human beings). Among archaeologists,
37400-516: The planned South African Solar Challenge are comparable competitions that reflect an international interest in the engineering and development of solar powered vehicles. Some vehicles use solar panels for auxiliary power, such as for air conditioning, to keep the interior cool, thus reducing fuel consumption. In 1975, the first practical solar boat was constructed in England. By 1995, passenger boats incorporating PV panels began appearing and are now used extensively. In 1996, Kenichi Horie made
37620-561: The pure water by-product going directly into the municipal water system. In addition, chemical energy storage is another solution to solar energy storage. Hydrogen production technologies have been a significant area of solar chemical research since the 1970s. Aside from electrolysis driven by photovoltaic or photochemical cells, several thermochemical processes have also been explored. One such route uses concentrators to split water into oxygen and hydrogen at high temperatures (2,300–2,600 °C or 4,200–4,700 °F). Another approach uses
37840-518: The result that in the following period people were "apt to assume that the appreciation of natural beauty and the painting of landscape is a normal and enduring part of our spiritual activity" Solar energy Solar energy is the radiant energy from the Sun 's light and heat , which can be harnessed using a range of technologies such as solar electricity , solar thermal energy (including solar water heating ) and solar architecture . It
38060-546: The resulting fragments and rubble strewn over the desert floor are further eroded by the wind. This picks up particles of sand and dust, which can remain airborne for extended periods – sometimes causing the formation of sand storms or dust storms . Wind-blown sand grains striking any solid object in their path can abrade the surface. Rocks are smoothed down, and the wind sorts sand into uniform deposits. The grains end up as level sheets of sand or are piled high in billowing sand dunes . Other deserts are flat, stony plains where all
38280-436: The rock surface experiences even greater temperature differentials. During the day the sky is usually clear and most of the sun 's radiation reaches the ground, but as soon as the sun sets, the desert cools quickly by radiating heat into space. In hot deserts, the temperature during daytime can exceed 45 °C (113 °F) in summer and plunge below freezing point at night during winter. Such large temperature variations have
38500-501: The sand stream can rise as the largest sand grains do not become airborne at all. They are transported by creep, being rolled along the desert floor or performing short jumps. During a sandstorm, the wind-blown sand particles become electrically charged . Such electric fields , which range in size up to 80 kV/m, can produce sparks and cause interference with telecommunications equipment. They are also unpleasant for humans and can cause headaches and nausea. The electric fields are caused by
38720-630: The scroll itself. Many painters also wrote poetry, especially in the scholar-official or literati tradition. Landscape images were present in the early Shijing and the Chuci , but in later poetry the emphasis changed, as in painting to the Shan shui ( Chinese : 山水 lit. "mountain-water") style featuring wild mountains, rivers and lakes, rather than landscape as a setting for a human presence. Shanshui poetry traditional Chinese : 山水詩 ; simplified Chinese : 山水诗 developed in China during
38940-435: The shade or underground during the heat of the day. They tend to be efficient at conserving water, extracting most of their needs from their food and concentrating their urine . Some animals remain in a state of dormancy for long periods, ready to become active again during the rare rainfall. They then reproduce rapidly while conditions are favorable before returning to dormancy. People have struggled to live in deserts and
39160-440: The sheet consists of thin horizontal layers of coarse silt and very fine to medium grain sand, separated by layers of coarse sand and pea-gravel which are a single grain thick. These larger particles anchor the other particles in place and may also be packed together on the surface so as to form a miniature desert pavement. Small ripples form on the sand sheet when the wind exceeds 24 km/h (15 mph). They form perpendicular to
39380-615: The shore I found myself of a huge sea of mist, Which meek and silent rested at my feet. A hundred hills their dusky backs upheaved All over this still ocean, and beyond, Far, far beyond, the vapours shot themselves In headlands, tongues, and promontory shapes, Into the sea, the real sea, that seemed To dwindle and give up its majesty, Usurped upon as far as sight could reach. from The Prelude (1805), Book 13, lines 41-51. by William Wordsworth One important aspect of British Romanticism – evident in painting and literature as well as in politics and philosophy –
39600-445: The skin and various thermoregulatory strategies to maintain its body temperature in one of the harshest environments on Earth. Landscape The character of a landscape helps define the self-image of the people who inhabit it and a sense of place that differentiates one region from other regions. It is the dynamic backdrop to people's lives. Landscape can be as varied as farmland, a landscape park or wilderness . The Earth has
39820-411: The skin. The arctic weasel has a metabolic rate that is two or three times as high as would be expected for an animal of its size. Birds have avoided the problem of losing heat through their feet by not attempting to maintain them at the same temperature as the rest of their bodies, a form of adaptive insulation. The emperor penguin has dense plumage, a downy under layer, an air insulation layer next to
40040-466: The soil until sparked into growth by rainfall. With annuals , such plants grow with great rapidity and may flower and set seed within weeks, aiming to complete their development before the last vestige of water dries up. For perennial plants, reproduction is more likely to be successful if the seed germinates in a shaded position, but not so close to the parent plant as to be in competition with it. Some seed will not germinate until it has been blown about on
40260-414: The south to provide light and warmth. The common features of passive solar architecture are orientation relative to the Sun, compact proportion (a low surface area to volume ratio), selective shading (overhangs) and thermal mass . When these features are tailored to the local climate and environment, they can produce well-lit spaces that stay in a comfortable temperature range. Socrates ' Megaron House
40480-477: The southern side of a building in the northern hemisphere or the northern side in the southern hemisphere, their leaves provide shade during the summer, while the bare limbs allow light to pass during the winter. Since bare, leafless trees shade 1/3 to 1/2 of incident solar radiation, there is a balance between the benefits of summer shading and the corresponding loss of winter heating. In climates with significant heating loads, deciduous trees should not be planted on
40700-463: The sparse vegetation cover and the activities of large mammals and people. Plants and animals in deserts are mostly adapted to extreme and prolonged water deficits , but their reproductive phenology often responds to short episodes of surplus. Competitive interactions are weak. Plants face severe challenges in arid environments. Problems they need to solve include how to obtain enough water, how to avoid being eaten and how to reproduce. Photosynthesis
40920-407: The stability and rate of change of topography under the force of gravity , and other factors, such as (in the very recent past) human alteration of the landscape. Many of these factors are strongly mediated by climate . Geologic processes include the uplift of mountain ranges , the growth of volcanoes , isostatic changes in land surface elevation (sometimes in response to surface processes), and
41140-439: The surface by evaporation and the formation of salt crystals may dislodge rock particles as sand or disintegrate rocks by exfoliation. Shallow caves are sometimes formed at the base of cliffs by this means. As the desert mountains decay, large areas of shattered rock and rubble occur. The process continues and the end products are either dust or sand. Dust is formed from solidified clay or volcanic deposits whereas sand results from
41360-462: The surface of the ground. Dunes are sometimes solitary, but they are more often grouped together in dune fields. When these are extensive, they are known as sand seas or ergs . The shape of the dune depends on the characteristics of the prevailing wind. Barchan dunes are produced by strong winds blowing across a level surface and are crescent-shaped with the concave side away from the wind. When there are two directions from which winds regularly blow,
41580-861: The surrounding environment. The higher temperatures result from increased absorption of solar energy by urban materials such as asphalt and concrete, which have lower albedos and higher heat capacities than those in the natural environment. A straightforward method of counteracting the UHI effect is to paint buildings and roads white and to plant trees in the area. Using these methods, a hypothetical "cool communities" program in Los Angeles has projected that urban temperatures could be reduced by approximately 3 °C at an estimated cost of US$ 1 billion, giving estimated total annual benefits of US$ 530 million from reduced air-conditioning costs and healthcare savings. Agriculture and horticulture seek to optimize
41800-573: The surrounding mountains. Former desert areas presently in non-arid environments, such as the Sandhills in Nebraska , are known as paleodeserts. In the Köppen climate classification system, deserts are classed as BWh (hot desert) or BWk (temperate desert). In the Thornthwaite climate classification system , deserts would be classified as arid megathermal climates. Polar deserts are
42020-610: The surrounding semi-arid lands for millennia. Nomads have moved their flocks and herds to wherever grazing is available, and oases have provided opportunities for a more settled way of life. The cultivation of semi-arid regions encourages erosion of soil and is one of the causes of increased desertification. Desert farming is possible with the aid of irrigation , and the Imperial Valley in California provides an example of how previously barren land can be made productive by
42240-431: The tallest type of dune. Rounded mounds of sand without a slip face are the rare dome dunes, found on the upwind edges of sand seas. In deserts where large amounts of limestone mountains surround a closed basin , such as at White Sands National Park in south-central New Mexico , occasional storm runoff transports dissolved limestone and gypsum into a low-lying pan within the basin where the water evaporates, depositing
42460-409: The technology has been embraced by vintners , who use the energy generated by solar panels to power grape presses. Greenhouses convert solar light to heat, enabling year-round production and the growth (in enclosed environments) of specialty crops and other plants not naturally suited to the local climate. Primitive greenhouses were first used during Roman times to produce cucumbers year-round for
42680-550: The term landscape can refer to the meanings and alterations people mark onto their surroundings. As such, landscape archaeology is often employed to study the human use of land over extensive periods of time. Landscape archaeology can be summed up by Nicole Branton's statement: The concept of cultural landscapes can be found in the European tradition of landscape painting . From the 16th century onwards, many European artists painted landscapes in favor of people, diminishing
42900-404: The theory did not entirely work against the development of landscape painting – for several centuries landscapes were regularly promoted to the status of history painting by the addition of small figures to make a narrative scene, typically religious or mythological. Dutch Golden Age painting of the 17th century saw the dramatic growth of landscape painting, in which many artists specialized, and
43120-496: The third and fourth centuries AD and left most of the varied landscapes of China largely unrepresented. Shan shui painting and poetry shows imaginary landscapes, though with features typical of some parts of South China; they remain popular to the present day. Fields and Gardens poetry ( simplified Chinese : 田园诗 ; traditional Chinese : 田園詩 ; pinyin : tiányuán shī ; Wade–Giles : t'ien-yuan-shih ; lit. 'fields and gardens poetry'), in poetry )
43340-414: The total installed capacity of solar hot water systems was approximately 436 thermal gigawatt (GW th ), and China is the world leader in their deployment with 309 GW th installed, taken up 71% of the market. Israel and Cyprus are the per capita leaders in the use of solar hot water systems with over 90% of homes using them. In the United States, Canada, and Australia, heating swimming pools
43560-409: The traditional color landscapes in some cities have been heavily influenced by natural geography, climate, local materials, ethnic culture, religion, and socioeconomic factors. Second, the growing problem of "color pollution" - through bright, solid-colored buildings, billboards, and lighting clusters - adversely affects people physically and psychologically. Third, homogenization of colors between cities
43780-699: The tropics and have more particularly proved that after our stores of oil and coal are exhausted the human race can receive unlimited power from the rays of the Sun. Solar hot water systems use sunlight to heat water. In middle geographical latitudes (between 40 degrees north and 40 degrees south), 60 to 70% of the domestic hot water use, with water temperatures up to 60 °C (140 °F), can be provided by solar heating systems. The most common types of solar water heaters are evacuated tube collectors (44%) and glazed flat plate collectors (34%) generally used for domestic hot water; and unglazed plastic collectors (21%) used mainly to heat swimming pools. As of 2015,
44000-405: The trunk is folded like a concertina , allowing it to expand, and a large specimen can hold eight tons of water after a good downpour. Other xerophytic plants have developed similar strategies by a process known as convergent evolution . They limit water loss by reducing the size and number of stomata, by having waxy coatings and hairy or tiny leaves. Some are deciduous, shedding their leaves in
44220-493: The use of the word desert can cause confusion. In English before the 20th century, desert was often used in the sense of "unpopulated area", without specific reference to aridity ; but today the word is most often used in its climate-science sense (an area of low precipitation). Phrases such as " desert island " and " Great American Desert ", or Shakespeare 's "deserts of Bohemia " ( The Winter's Tale ) in previous centuries did not necessarily imply sand or aridity; their focus
44440-410: The view from a distance or a temporal view into the future, with the sense of opportunity or expectation. When understood broadly as landscape poetry and when assessed from its establishment to the present, topographical poetry can take on many formal situations and types of places. Kenneth Baker, in his "Introduction to The Faber Book of Landscape Poetry , identifies 37 varieties and compiles poems from
44660-456: The water unusable. Molten salt can be employed as a thermal energy storage method to retain thermal energy collected by a solar tower or solar trough of a concentrated solar power plant so that it can be used to generate electricity in bad weather or at night. It was demonstrated in the Solar Two project from 1995 to 1999. The system is predicted to have an annual efficiency of 99%,
44880-408: The way they do, to understand landform history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling . Geomorphology is practiced within physical geography , geology , geodesy , engineering geology , archaeology and geotechnical engineering . This broad base of interests contributes to many research styles and interests within
45100-476: The western edges of continental land masses in regions where cold currents approach the land or cold water upwellings rise from the ocean depths. The cool winds crossing this water pick up little moisture and the coastal regions have low temperatures and very low rainfall, the main precipitation being in the form of fog and dew. The range of temperatures on a daily and annual scale is relatively low, being 11 °C (20 °F) and 5 °C (9 °F) respectively in
45320-404: The wind blows, saltation and creep take place on the windward side of the dune and individual grains of sand move uphill. When they reach the crest, they cascade down the far side. The upwind slope typically has a gradient of 10° to 20° while the lee slope is around 32°, the angle at which loose dry sand will slip. As this wind-induced movement of sand grains takes place, the dune moves slowly across
45540-400: The wind continually removes fine-grained material, which becomes wind-blown sand. This exposes coarser-grained material, mainly pebbles with some larger stones or cobbles , leaving a desert pavement , an area of land overlaid by closely packed smooth stones forming a tessellated mosaic. Different theories exist as to how exactly the pavement is formed. It may be that after the sand and dust
45760-510: The wind direction and gradually move across the surface as the wind continues to blow. The distance between their crests corresponds to the average length of jumps made by particles during saltation. The ripples are ephemeral and a change in wind direction causes them to reorganise. Sand dunes are accumulations of windblown sand piled up in mounds or ridges. They form downwind of copious sources of dry, loose sand and occur when topographic and climatic conditions cause airborne particles to settle. As
45980-458: The works of the Greek poet Theocritus (c. 316 - c. 260 BC). The Romantic period poet William Wordsworth created a modern, more realistic form of pastoral with Michael, A Pastoral Poem (1800). An early form of landscape poetry, Shanshui poetry , developed in China during the third and fourth centuries A.D. Topographical poetry is a genre of poetry that describes, and often praises,
46200-464: The world depict little that could really be called landscape , although ground-lines and sometimes indications of mountains, trees or other natural features are included. The earliest "pure landscapes" with no human figures are frescos from Minoan Greece of around 1500 BCE. Hunting scenes, especially those set in the enclosed vista of the reed beds of the Nile Delta from Ancient Egypt, can give
46420-475: The world, around 20% of desert is sand, varying from only 2% in North America to 30% in Australia and over 45% in Central Asia. Where sand does occur, it is usually in large quantities in the form of sand sheets or extensive areas of dunes . A sand sheet is a near-level, firm expanse of partially consolidated particles in a layer that varies from a few centimeters to a few meters thick. The structure of
46640-457: Was a change in the way people perceived and valued the landscape. In particular, after William Gilpin 's Observations on the River Wye was published in 1770, the idea of the picturesque began to influence artists and viewers. Gilpin advocated approaching the landscape "by the rules of picturesque beauty," which emphasized contrast and variety. Edmund Burke 's A Philosophical Enquiry into
46860-433: Was a contrasting poetic movement which lasted for centuries, with a focused on the nature found in gardens, in backyards, and in the cultivated countryside. Fields and Gardens poetry is one of many Classical Chinese poetry genres . One of the main practitioners of the Fields and Gardens poetry genre was Tao Yuanming (also known as Tao Qian (365–427), among other names or versions of names). Tao Yuanming has been regarded as
47080-407: Was determined to stress the agency of culture as a force in shaping the visible features of the Earth's surface in delimited areas. Within his definition, the physical environment retains a central significance, as the medium with and through which human cultures act. His classic definition of a 'cultural landscape' reads as follows: The cultural landscape is fashioned from a natural landscape by
47300-529: Was felt throughout Europe, as well as on major Victorian novelists in Britain, such as Emily Brontë , Mrs Gaskell , George Eliot , and Thomas Hardy , as well as John Cowper Powys in the 20th-century. Margaret Drabble in A Writer's Britain suggests that Thomas Hardy "is perhaps the greatest writer of rural life and landscape" in English. Among European writers influenced by Scott were Frenchmen Honoré de Balzac and Alexandre Dumas and Italian Alessandro Manzoni . Manzoni's famous novel The Betrothed
47520-513: Was founded in Russia in the early 20th century by L. S. Berg and others, and outside Russia by the German S. Passarge. The conception of landscape as the relationship between various components of natural environments and geochemisty was devoted by soviet scientist Viktor Sochava, based on the ideas of american geographer George Van Dyne Integrated landscape management is a way of managing
47740-457: Was inspired by Walter Scott 's Ivanhoe . Also influenced by Romanticism's approach to landscape was the American novelist Fenimore Cooper , who was admired by Victor Hugo and Balzac and characterized as the "American Scott ." Landscape in Chinese poetry has often been closely tied to Chinese landscape painting, which developed much earlier than in the West. Many poems evoke specific paintings, and some are written in more empty areas of
47960-469: Was particularly influential. By the end of the 18th century the English garden was being imitated by the French landscape garden, and as far away as St. Petersburg, Russia, in Pavlovsk , the gardens of the future Emperor Paul . It also had a major influence on the form of the public parks and gardens which appeared around the world in the 19th century. Landscape architecture is a multi-disciplinary field, incorporating aspects of botany , horticulture ,
48180-461: Was stated that solar energy has a global potential of 1,600 to 49,800 exajoules (4.4 × 10 to 1.4 × 10 kWh) per year (see table below) . Quantitative relation of global solar potential vs. the world's primary energy consumption : Source: United Nations Development Programme – World Energy Assessment (2000) Solar thermal technologies can be used for water heating, space heating, space cooling and process heat generation. In 1878, at
48400-457: Was the sparse population. Deserts occupy about one third of Earth's land surface. Bottomlands may be salt -covered flats. Eolian processes are major factors in shaping desert landscapes. Polar deserts (also seen as "cold deserts") have similar features, except the main form of precipitation is snow rather than rain. Antarctica is the world's largest cold desert (composed of about 98% thick continental ice sheet and 2% barren rock). Some of
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