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51-752: The Thar Desert , also known as the Great Indian Desert , is an arid region in the north-western part of the Indian subcontinent that covers an area of 200,000 km (77,000 sq mi) in India and Pakistan . It is the world's 18th-largest desert , and the world's 9th-largest hot subtropical desert . About 85% of the Thar Desert is in India, and about 15% is in Pakistan. The Thar Desert
102-653: A country have become erodible. For example, on the Madagascar high central plateau , which constitutes approximately ten percent of that country's land area, most of the land area is devegetated, and gullies have eroded into the underlying soil to form distinctive gulleys called lavakas . These are typically 40 meters (130 ft) wide, 80 meters (260 ft) long and 15 meters (49 ft) deep. Some areas have as many as 150 lavakas/square kilometer, and lavakas may account for 84% of all sediments carried off by rivers. This siltation results in discoloration of rivers to
153-468: A dark red brown color and leads to fish kills. In addition, sedimentation of river basins implies sediment management and siltation costs.The cost of removing an estimated 135 million m of accumulated sediments due to water erosion only is likely exceeding 2.3 billion euro (€) annually in the EU and UK, with large regional differences between countries. Erosion is also an issue in areas of modern farming, where
204-432: A grain, such as pits, fractures, ridges, and scratches. These are most commonly evaluated on quartz grains, because these retain their surface markings for long periods of time. Surface texture varies from polished to frosted, and can reveal the history of transport of the grain; for example, frosted grains are particularly characteristic of aeolian sediments, transported by wind. Evaluation of these features often requires
255-458: A higher density and viscosity . In typical rivers the largest carried sediment is of sand and gravel size, but larger floods can carry cobbles and even boulders . Wind results in the transportation of fine sediment and the formation of sand dune fields and soils from airborne dust. Glaciers carry a wide range of sediment sizes, and deposit it in moraines . The overall balance between sediment in transport and sediment being deposited on
306-426: A hydrodynamic sorting process within the marine environment leading to a seaward fining of sediment grain size. One cause of high sediment loads is slash and burn and shifting cultivation of tropical forests. When the ground surface is stripped of vegetation and then seared of all living organisms, the upper soils are vulnerable to both wind and water erosion. In a number of regions of the earth, entire sectors of
357-622: A local community, the Bishnois , has made special efforts to protect them. Other mammals in the Thar Desert include a subspecies of red fox ( Vulpes vulpes pusilla ) and the caracal , and a number of reptiles dwell there too. The region is a haven for 141 species of migratory and resident desert birds, including harriers , falcons , buzzards , kestrels , vultures , short-toed eagles ( Circaetus gallicus ), tawny eagles ( Aquila rapax ), greater spotted eagles ( Aquila clanga ), and laggar falcons ( Falco jugger ). The Indian peafowl
408-636: A paleo channel of Ghaggar-Hakra River - identified with the paleo Sarasvati River , after confluence with Sutlej flowed into the Nara river - a delta channel of the Indus River , changed its course, leaving the Ghaggar-Hakra as a system of monsoon-fed rivers which did not reach the sea and now ends in the Thar desert. Around 5,000 years ago when the monsoons that fed the rivers diminished further,
459-470: A result, can cause exposed sediment to become more susceptible to erosion and delivery to the marine environment during rainfall events. Sediment can negatively affect corals in many ways, such as by physically smothering them, abrading their surfaces, causing corals to expend energy during sediment removal, and causing algal blooms that can ultimately lead to less space on the seafloor where juvenile corals (polyps) can settle. When sediments are introduced into
510-408: Is a major opium production and consumption area. P. cineraria wood is reported to contain high calorific value and provide high-quality fuel wood. The lopped branches are good as fencing material. Its roots also encourage nitrogen fixation, which produces higher crop yields. Desert safaris on camels have become increasingly popular around Jaisalmer. Domestic and international tourists frequent
561-557: Is a resident breeder in the Thar region. The peacock is designated as the national bird of India and the provincial bird of the Punjab (Pakistan) . It can be seen sitting on khejri or pipal trees in villages or Deblina. The natural vegetation of this dry area is classified as northwestern thorn scrub forest (i.e. small, loosely-scattered patches of greenery). The densities and sizes of these green patches increase from west to east, following an increase in rainfall. The primary vegetation of
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#1732797835963612-539: Is about 4.56% of the total geographical area of India. More than 60% of the desert lies in the Indian state of Rajasthan ; the portion in India also extends into Gujarat , Punjab , and Haryana . The portion in Pakistan extends into the provinces of Sindh and Punjab (the portion in the latter province is referred to as the Cholistan Desert ). The Indo-Gangetic Plain lies to the north, west and northeast of
663-551: Is expected to be delivered to the outlet of the river. The sediment transfer and deposition can be modelled with sediment distribution models such as WaTEM/SEDEM. In Europe, according to WaTEM/SEDEM model estimates the Sediment Delivery Ratio is about 15%. Watershed development near coral reefs is a primary cause of sediment-related coral stress. The stripping of natural vegetation in the watershed for development exposes soil to increased wind and rainfall and, as
714-581: Is measured on a log base 2 scale, called the "Phi" scale, which classifies particles by size from "colloid" to "boulder". The shape of particles can be defined in terms of three parameters. The form is the overall shape of the particle, with common descriptions being spherical, platy, or rodlike. The roundness is a measure of how sharp grain corners are. This varies from well-rounded grains with smooth corners and edges to poorly rounded grains with sharp corners and edges. Finally, surface texture describes small-scale features such as scratches, pits, or ridges on
765-585: Is one of the most heavily populated desert areas in the world with the main occupations of its inhabitants being agriculture and animal husbandry. Agricultural production is mainly from kharif crops , which are grown in the summer season and seeded in June and July. These are then harvested in September and October and include bajra , pulses such as guar , jowar ( Sorghum vulgare ), maize ( zea mays ), sesame and groundnuts . The Thar region of Rajasthan
816-930: Is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation ; if buried, they may eventually become sandstone and siltstone ( sedimentary rocks ) through lithification . Sediments are most often transported by water ( fluvial processes ), but also wind ( aeolian processes ) and glaciers . Beach sands and river channel deposits are examples of fluvial transport and deposition , though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments. Sediment can be classified based on its grain size , grain shape, and composition. Sediment size
867-545: The Indus Valley Civilisation (IVC) prospered in this area, with the rise of numerous IVC urban sites at Kalibangan ( Rajasthan ), Banawali and Rakhigarhi ( Haryana ), Dholavira and Lothal ( Gujarat ) along this course. 4,000 years ago when monsoons diminished even further, the dried-up Harkra become an intermittent river, and the urban Harappan civilisation declined, becoming localized in smaller agricultural communities. The northeastern part of
918-476: The subtropics ; these regions include parts of Africa , Asia , South America , North America , and Australia . The distribution of aridity at any time is largely the result of the general circulation of the atmosphere . The latter does change significantly over time through climate change . For example, temperature increase by 1.5–2.1 percent across the Nile Basin over the next 30–40 years could change
969-533: The Bhatti rulers of Multhan because they wanted to end the slave raids that were made by the Turkic ruler of Ghazni, but the alliance was broken apart by Alp Tigin in 977 CE. Bhati dominions continued to shift southwards: they ruled Multan, then finally got pushed into Cholistan and Jaisalmer, where Rawal Devaraja built Dera Rawal / Derawar . Jaisalmer was founded as the new capital in 1156 by Maharawal Jaisal Singh and
1020-456: The Indian section of the Thar to Pakistani Thar, whilst thousands of Hindu families also migrated from Pakistani Thar to the Indian section. Arid Aridity is the condition of a region that severely lacks available water, to the extent of hindering or preventing the growth and development of plant and animal life. Regions with arid climates tend to lack vegetation and are called xeric or desertic . Most arid climates are located in
1071-422: The Thar Desert is composed of trees, shrubs , and perennial herb species, including: The endemic floral species include Calligonum polygonoides , Prosopis cineraria , Acacia nilotica , Tamarix aphylla , and Cenchrus biflorus . The Thar people are the natives of the area. The Thar Desert is the most widely populated desert in the world, with a population density of 83 people per km. In India,
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#17327978359631122-555: The Thar Desert lies between the Aravalli Hills . The desert stretches to Punjab and Haryana in the north, to the Great Rann of Kutch along the coast, and to the alluvial plains of the Indus River in the west and northwest. Much of the desert area is covered by huge, shifting sand dunes that receive sediments from the alluvial plains and the coast. The sand is highly mobile due to the strong winds that rise each year before
1173-836: The Thar Desert. It was built to halt any spreading of the desert into fertile areas. There are several protected areas in the Thar Desert: Some wildlife species that are fast vanishing in other parts of India are found in the desert in large numbers, including the blackbuck ( Antilope cervicapra ), chinkara ( Gazella bennettii ), and Indian wild ass ( Equus hemionus khur ) in the Rann of Kutch . This may be partly because they are well adapted to this environment: they are smaller than similar animals that live in other environments, and they are mainly nocturnal. It may also be because grasslands in this region have not been transformed into cropland as fast as in other regions, and because
1224-469: The Thar desert, the Rann of Kutch lies to its south, and the Aravali Range borders the desert to the east. The most recent paleontological discovery in 2023 from the Thar Desert in India, dating back to 167 million years ago, pertains to a herbivorous dinosaur group known as dicraeosaurids . This discovery marks the first of its kind to be unearthed in India and is also the oldest specimen of
1275-600: The bed is given by the Exner equation . This expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This equation is important in that changes in the power of the flow change the ability of the flow to carry sediment, and this is reflected in the patterns of erosion and deposition observed throughout a stream. This can be localized, and simply due to small obstacles; examples are scour holes behind boulders, where flow accelerates, and deposition on
1326-579: The body of water. Terrigenous material is often supplied by nearby rivers and streams or reworked marine sediment (e.g. sand ). In the mid-ocean, the exoskeletons of dead organisms are primarily responsible for sediment accumulation. Deposited sediments are the source of sedimentary rocks , which can contain fossils of the inhabitants of the body of water that were, upon death, covered by accumulating sediment. Lake bed sediments that have not solidified into rock can be used to determine past climatic conditions. The major areas for deposition of sediments in
1377-417: The coastal regions of the ocean, the proportion of land, marine, and organic-derived sediment that characterizes the seafloor near sources of sediment output is altered. In addition, because the source of sediment (i.e., land, ocean, or organically) is often correlated with how coarse or fine sediment grain sizes that characterize an area are on average, grain size distribution of sediment will shift according to
1428-507: The desert seeking adventure on camels for one to several days. This ecotourism industry ranges from cheaper backpacker treks to plush Arabian night-style campsites replete with banquets and cultural performances. During the treks, tourists are able to view the fragile and beautiful ecosystem of the Thar Desert. This form of tourism provides income to many operators and camel owners in Jaisalmer, as well as employment for many camel trekkers in
1479-408: The desert to shift. To counteract this problem, sand dunes are stabilised by first erecting micro windbreak barriers with scrub material and then by afforestation of the treated dunes—planting the seedlings of shrubs (such as phog , senna , and castor oil plant ) and trees (such as gum acacia , Prosopis juliflora , and lebbek tree ). The 649-km-long Indira Gandhi Canal brings fresh water to
1530-593: The desert villages nearby. People from various parts of the world come to see the Pushkar ka Mela (Pushkar Fair) and oases. The government of India initiated departmental exploration for oil in 1955 and 1956 in the Jaisalmer area, Oil India Limited discovered natural gas in 1988 in the Jaisalmer basin . The Desert National Park in Jaisalmer district has a collection of 180-million-year- old animal and plant fossils. Jaisalmer State 's historical foundations are in
1581-604: The dry season. The salt comes from the weathering of rocks in the region. Lithic tools belonging to the prehistoric Aterian culture of the Maghreb have been discovered in Middle Paleolithic deposits in the Thar Desert. The climate is arid and subtropical. Average temperature varies with season, and extremes can range from near-freezing in the winter to more than 50 °C in the summer months. Average annual rainfall ranges from 100 to 500 mm, and occurs during
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1632-458: The economic decline, but the kingdom nevertheless became impoverished. To make matters worse, there was a severe drought and a resulting famine from 1895 to 1900, during the reign of Maharawal Salivahan Singh, which caused the widespread loss of the livestock upon which the increasingly agriculturally based kingdom had come to rely. In 1965 and 1971, population exchanges took place in the Thar between India and Pakistan; 3,500 Muslims shifted from
1683-422: The edges and corners of particle are. Complex mathematical formulas have been devised for its precise measurement, but these are difficult to apply, and most geologists estimate roundness from comparison charts. Common descriptive terms range from very angular to angular to subangular to subrounded to rounded to very rounded, with increasing degree of roundness. Surface texture describes the small-scale features of
1734-510: The flow. In geography and geology , fluvial sediment processes or fluvial sediment transport are associated with rivers and streams and the deposits and landforms created by sediments. It can result in the formation of ripples and dunes , in fractal -shaped patterns of erosion, in complex patterns of natural river systems, and in the development of floodplains and the occurrence of flash floods . Sediment moved by water can be larger than sediment moved by air because water has both
1785-655: The group ever recorded in the global fossil record. During the Last Glacial Maximum 20,000 before present, an approximately 2,400,000 square kilometres (930,000 sq mi) ice sheet covered the Tibetan Plateau , causing excessive radiative forcing i.e. the ice in Tibet reflected at least four times more radiation energy per unit area into space than ice at higher latitudes , which further cooled overlying atmosphere at that time. This impacted
1836-414: The inhabitants comprise Hindus , Jains , Sikhs , and Muslims . In Pakistan, inhabitants include both Muslims and Hindus. About 40% of the total population of Rajasthan lives in the Thar Desert. The main occupations of the inhabitants are agriculture and animal husbandry . Jodhpur , the largest city in the region, lies in the scrub forest zone at the desert's perimeter. Bikaner and Jaisalmer are
1887-539: The inside of meander bends. Erosion and deposition can also be regional; erosion can occur due to dam removal and base level fall. Deposition can occur due to dam emplacement that causes the river to pool and deposit its entire load, or due to base level rise. Seas, oceans, and lakes accumulate sediment over time. The sediment can consist of terrigenous material, which originates on land, but may be deposited in either terrestrial, marine, or lacustrine (lake) environments, or of sediments (often biological) originating in
1938-538: The large empire ruled by the Bhati dynasty. The empire stretched from what is now Ghazni in modern-day Afghanistan to what is Sialkot , Lahore and Rawalpindi in modern-day Pakistan to the region that is Bhatinda and Hanumangarh in modern-day India. The empire crumbled over time because of continuous invasions from central Asia. According to Satish Chandra, the Hindu Shahis of Afghanistan made an alliance with
1989-432: The largest cities located entirely in the desert. In the true desert areas, the only sources of water for animals or humans are small, scattered ponds - some that are natural ( tobas ) and some that are human-made ( johads ). The persistence of water scarcity heavily influences life in all areas of the Thar, prompting many inhabitants to adopt a nomadic lifestyle. Most of the permanent human settlements are located near
2040-406: The long, intermediate, and short axis lengths of the particle. The form ψ l {\displaystyle \psi _{l}} varies from 1 for a perfectly spherical particle to very small values for a platelike or rodlike particle. An alternate measure was proposed by Sneed and Folk: which, again, varies from 0 to 1 with increasing sphericity. Roundness describes how sharp
2091-435: The marine environment include: One other depositional environment which is a mixture of fluvial and marine is the turbidite system, which is a major source of sediment to the deep sedimentary and abyssal basins as well as the deep oceanic trenches . Any depression in a marine environment where sediments accumulate over time is known as a sediment trap . The null point theory explains how sediment deposition undergoes
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2142-579: The onset of the monsoon . The Luni River is the only river in the desert. Rainfall is 100 to 500 mm (4 to 20 in) per year, almost all of it between June and September. Saltwater lakes within the Thar Desert include the Sambhar , Kuchaman, Didwana , Pachpadra , and Phalodi in Rajasthan and Kharaghoda in Gujarat. These lakes receive and collect rainwater during monsoon and evaporate during
2193-424: The region from semi-arid to arid, significantly reducing the land usable for agriculture . In addition, changes in land use can increase demands on soil water and thereby increase aridity. This climatology -related article is a stub . You can help Misplaced Pages by expanding it . Sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion , and
2244-628: The regional climate. Without the thermal low pressure caused by the heating, there was no monsoon over the Indian subcontinent . This lack of monsoon caused extensive rainfall over the Sahara , expansion of the Thar Desert, more dust deposited into the Arabian Sea , a lowering of the biotic life zones on the Indian subcontinent, and animals responded to this shift in climate with the Javan rusa deer migrating into India. 10,000-8,000 years ago
2295-491: The relative input of land (typically fine), marine (typically coarse), and organically-derived (variable with age) sediment. These alterations in marine sediment characterize the amount of sediment suspended in the water column at any given time and sediment-related coral stress. In July 2020, marine biologists reported that aerobic microorganisms (mainly), in " quasi-suspended animation ", were found in organically-poor sediments, up to 101.5 million years old, 250 feet below
2346-473: The removal of native vegetation for the cultivation and harvesting of a single type of crop has left the soil unsupported. Many of these regions are near rivers and drainages. Loss of soil due to erosion removes useful farmland, adds to sediment loads, and can help transport anthropogenic fertilizers into the river system, which leads to eutrophication . The Sediment Delivery Ratio (SDR) is fraction of gross erosion (interill, rill, gully and stream erosion) that
2397-503: The short July-to-September southwest monsoon. The desert has both a very dry part (the Marusthali region in the west) and a semidesert part (in the east) that has fewer sand dunes and slightly more precipitation. The soil of the Thar Desert remains dry for much of the year, so it is prone to wind erosion . High-velocity winds blow soil from the desert, depositing some of it on neighboring fertile lands, and causing sand dunes within
2448-473: The state took its name from the capital. On 11 December 1818 Jaisalmer became a British protectorate through the Rajputana Agency . Because the kingdom's main source of income had long been levies on caravans , its economy suffered after Bombay became a major port, and sea trade largely replaced trade along the traditional land routes. Maharawals Ranjit Singh and Bairi Sal Singh tried to reverse
2499-445: The surface of the grain. Form (also called sphericity ) is determined by measuring the size of the particle on its major axes. William C. Krumbein proposed formulas for converting these numbers to a single measure of form, such as where D L {\displaystyle D_{L}} , D I {\displaystyle D_{I}} , and D S {\displaystyle D_{S}} are
2550-530: The two seasonal streams of the Karon-Jhar hills. Potable groundwater is also rare in the Thar Desert. Much of it tastes sour due to dissolved minerals. Potable water is mostly available only deep underground. When wells are dug that happen to yield sweet tasting water, people tend to settle near them, but such wells are difficult and dangerous to dig, sometimes claiming the lives of the well-diggers. Crowded housing conditions are common in some areas. The Thar
2601-494: The use of a scanning electron microscope . Composition of sediment can be measured in terms of: This leads to an ambiguity in which clay can be used as both a size-range and a composition (see clay minerals ). Sediment is transported based on the strength of the flow that carries it and its own size, volume, density, and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, while larger or denser particles will be more likely to fall through
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