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99-404: The term "Great Basin" is applied to hydrographic , biological , floristic , physiographic, topographic , and ethnographic geographic areas. The name was originally coined by John C. Frémont , who, based on information gleaned from Joseph R. Walker as well as his own travels, recognized the hydrographic nature of the landform as "having no connection to the ocean". The hydrographic definition

198-408: A drop in the ground surface. In unconsolidated aquifers, groundwater is produced from pore spaces between particles of gravel, sand, and silt. If the aquifer is confined by low-permeability layers, the reduced water pressure in the sand and gravel causes slow drainage of water from the adjoining confining layers. If these confining layers are composed of compressible silt or clay, the loss of water to

297-402: A former lake bed, has experienced rates of subsidence of up to 40 centimetres (1 foot 4 inches) per year. For coastal cities, subsidence can increase the risk of other environmental issues, such as sea level rise . For example, Bangkok is expected to have 5.138 million people exposed to coastal flooding by 2070 because of these combining factors. If the surface water source

396-1076: A global level, although priority chemicals will vary by country. There is a lot of heterogeneity of hydrogeologic properties. For this reason, salinity of groundwater is often highly variable over space. This contributes to highly variable groundwater security risks even within a specific region. Salinity in groundwater makes the water unpalatable and unusable and often occurs in coastal areas, for example in Bangladesh and East and West Africa. Municipal and industrial water supplies are provided through large wells. Multiple wells for one water supply source are termed "wellfields", which may withdraw water from confined or unconfined aquifers. Using groundwater from deep, confined aquifers provides more protection from surface water contamination. Some wells, termed "collector wells", are specifically designed to induce infiltration of surface (usually river) water. Aquifers that provide sustainable fresh groundwater to urban areas and for agricultural irrigation are typically close to

495-489: A hazard to navigation such as rocks, shoals , reefs and other features that obstruct ship passage. Bottom measurements also include collection of the nature of the bottom as it pertains to effective anchoring. Unlike oceanography, hydrography will include shore features, natural and manmade, that aid in navigation. Therefore, a hydrographic survey may include the accurate positions and representations of hills , mountains and even lights and towers that will aid in fixing

594-408: A home and then returned to the ground in another well. During cold seasons, because it is relatively warm, the water can be used in the same way as a source of heat for heat pumps that is much more efficient than using air. Groundwater makes up about thirty percent of the world's fresh water supply, which is about 0.76% of the entire world's water, including oceans and permanent ice. About 99% of

693-770: A language in the Numic language group. To close a 1951 Indian Claims Commission case, the Western Shoshone Claims Distribution Act of 2004 established the United States payment of $ 117 million to the Great Basin tribe for the acquisition of 39,000 square miles (100,000 km). European exploration of the Great Basin occurred during the 18th century Spanish colonization of the Americas . The first immigrant American to cross

792-519: A long time without severe consequences. Nevertheless, over the long term the average rate of seepage above a groundwater source is the upper bound for average consumption of water from that source. Groundwater is naturally replenished by surface water from precipitation , streams , and rivers when this recharge reaches the water table. Groundwater can be a long-term ' reservoir ' of the natural water cycle (with residence times from days to millennia), as opposed to short-term water reservoirs like

891-722: A permanently reduced capacity to hold water. The city of New Orleans, Louisiana is actually below sea level today, and its subsidence is partly caused by removal of groundwater from the various aquifer/aquitard systems beneath it. In the first half of the 20th century, the San Joaquin Valley experienced significant subsidence , in some places up to 8.5 metres (28 feet) due to groundwater removal. Cities on river deltas, including Venice in Italy, and Bangkok in Thailand, have experienced surface subsidence; Mexico City, built on

990-421: A preference for multi-use surveys, so that the same data collected for nautical charting purposes can also be used for bathymetric portrayal. Even though, in places, hydrographic survey data may be collected in sufficient detail to portray bottom topography in some areas, hydrographic charts only show depth information relevant for safe navigation and should not be considered as a product that accurately portrays

1089-621: A remit to gather and distribute charts to HM Ships. Within a year existing charts from the previous two centuries had been collated, and the first catalog published. The first chart produced under the direction of the Admiralty , was a chart of Quiberon Bay in Brittany , and it appeared in 1800. Under Captain Thomas Hurd the department received its first professional guidelines, and the first catalogs were published and made available to

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1188-640: A sectional flow rate of moving water through a section and or current. Uncrewed Surface Vessels (USVs) and are commonly used for hydrographic surveys - they are often equipped with some sort of sonar. Single-beam echosounders, multibeam echosounders , and side scan sonars are all frequently used in hydrographic applications. The knowledge gained from these surveys aid in disaster planning, port and harbor maintenance, and various other coastal planning activities. Hydrographic services in most countries are carried out by specialized hydrographic offices . The international coordination of hydrographic efforts lies with

1287-488: A ship's position, as well as the physical aspects of the sea and seabed. Hydrography, mostly for reasons of safety, adopted a number of conventions that have affected its portrayal of the data on nautical charts. For example, hydrographic charts are designed to portray what is safe for navigation, and therefore will usually tend to maintain least depths and occasionally de-emphasize the actual submarine topography that would be portrayed on bathymetric charts . The former are

1386-399: Is a highly useful and often abundant resource. Most land areas on Earth have some form of aquifer underlying them, sometimes at significant depths. In some cases, these aquifers are rapidly being depleted by the human population. Such over-use, over-abstraction or overdraft can cause major problems to human users and to the environment. The most evident problem (as far as human groundwater use

1485-466: Is also subject to substantial evaporation, a groundwater source may become saline . This situation can occur naturally under endorheic bodies of water, or artificially under irrigated farmland. In coastal areas, human use of a groundwater source may cause the direction of seepage to ocean to reverse which can also cause soil salinization . As water moves through the landscape, it collects soluble salts, mainly sodium chloride . Where such water enters

1584-632: Is an additional water source that was not used previously. First, flood mitigation schemes, intended to protect infrastructure built on floodplains, have had the unintended consequence of reducing aquifer recharge associated with natural flooding. Second, prolonged depletion of groundwater in extensive aquifers can result in land subsidence , with associated infrastructure damage – as well as, third, saline intrusion . Fourth, draining acid sulphate soils, often found in low-lying coastal plains, can result in acidification and pollution of formerly freshwater and estuarine streams. Groundwater

1683-511: Is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table . Groundwater is recharged from the surface; it may discharge from the surface naturally at springs and seeps , and can form oases or wetlands . Groundwater is also often withdrawn for agricultural , municipal , and industrial use by constructing and operating extraction wells . The study of

1782-417: Is concerned) is a lowering of the water table beyond the reach of existing wells. As a consequence, wells must be drilled deeper to reach the groundwater; in some places (e.g., California , Texas , and India ) the water table has dropped hundreds of feet because of extensive well pumping. The GRACE satellites have collected data that demonstrates 21 of Earth's 37 major aquifers are undergoing depletion. In

1881-412: Is fresh water located in the subsurface pore space of soil and rocks . It is also water that is flowing within aquifers below the water table . Sometimes it is useful to make a distinction between groundwater that is closely associated with surface water , and deep groundwater in an aquifer (called " fossil water " if it infiltrated into the ground millennia ago ). Groundwater can be thought of in

1980-545: Is less visible and more difficult to clean up than pollution in rivers and lakes. Groundwater pollution most often results from improper disposal of wastes on land. Major sources include industrial and household chemicals and garbage landfills , excessive fertilizers and pesticides used in agriculture, industrial waste lagoons, tailings and process wastewater from mines, industrial fracking , oil field brine pits, leaking underground oil storage tanks and pipelines, sewage sludge and septic systems . Additionally, groundwater

2079-433: Is more commonly called hydrometry or hydrology . Hydrography of rivers and streams is also an integral part of water management. Most reservoirs in the United States use dedicated stream gauging and rating tables to determine inflows into the reservoir and outflows to irrigation districts, water municipalities and other users of captured water. River/stream hydrographers use handheld and bank mounted devices, to capture

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2178-549: Is nicknamed "The Loneliest Road in America", and Nevada State Route 375 is designated the "Extraterrestrial Highway". The Great Basin is traversed by several rail lines including the Union Pacific Railroad 's Overland Route (Union Pacific Railroad) through Reno and Ogden , Feather River Route , Central Corridor and Los Angeles and Salt Lake Railroad . There has been a succession of indigenous peoples of

2277-468: Is rapidly increasing with population growth, while climate change is imposing additional stress on water resources and raising the probability of severe drought occurrence. The anthropogenic effects on groundwater resources are mainly due to groundwater pumping and the indirect effects of irrigation and land use changes. Groundwater plays a central role in sustaining water supplies and livelihoods in sub-Saharan Africa . In some cases, groundwater

2376-560: Is susceptible to saltwater intrusion in coastal areas and can cause land subsidence when extracted unsustainably, leading to sinking cities (like Bangkok ) and loss in elevation (such as the multiple meters lost in the Central Valley of California ). These issues are made more complicated by sea level rise and other effects of climate change , particularly those on the water cycle . Earth's axial tilt has shifted 31 inches because of human groundwater pumping. Groundwater

2475-400: Is the most accessed source of freshwater around the world, including as drinking water , irrigation , and manufacturing . Groundwater accounts for about half of the world's drinking water, 40% of its irrigation water, and a third of water for industrial purposes. Another estimate stated that globally groundwater accounts for about one third of all water withdrawals , and surface water for

2574-536: Is the most commonly used, and is the only one with a definitive border. The other definitions yield not only different geographical boundaries of "Great Basin" regions but regional borders that vary from source to source. The Great Basin Desert is defined by plant and animal communities, and, according to the National Park Service , its boundaries approximate the hydrographic Great Basin but exclude

2673-520: Is the result of extension and thinning of the lithosphere , which is composed of crust and upper mantle . Extensional environments like the Basin and Range are characterized by listric normal faulting , or faults that level out with depth. Opposing normal faults link at depth producing a horst and graben geometry, where horst refers to the upthrown fault block and graben to the down dropped fault block. Sediment build-up over thousands of years filled

2772-456: Is used for irrigation. Occasionally, sedimentary or "fossil" aquifers are used to provide irrigation and drinking water to urban areas. In Libya, for example, Muammar Gaddafi's Great Manmade River project has pumped large amounts of groundwater from aquifers beneath the Sahara to populous areas near the coast. Though this has saved Libya money over the alternative, seawater desalination,

2871-598: The Cui-ui sucker fish (endangered 1967) and the Lahontan cutthroat trout (threatened 1970). Large invertebrates include tarantulas (genus Aphonopelma ) and Mormon crickets . Exotic species, including chukar , grey partridge , and Himalayan snowcock , have been successfully introduced to the Great Basin, although the latter has only thrived in the Ruby Mountains . Cheatgrass , an invasive species which

2970-701: The Great Basin fence lizard , longnose leopard lizard and horned lizard are common, especially in lower elevations. Rattlesnakes and gopher snakes are also present. The Inyo Mountains salamander is endangered. Shorebirds such as phalaropes and curlews can be found in wet areas. American white pelicans are common at Pyramid Lake . Golden eagles are also very common in the Great Basin. Mourning dove , western meadowlark , black-billed magpie , and common raven are other common bird species. Two endangered species of fish are found in Pyramid Lake:

3069-722: The Humboldt Sink are a few of the "drains" in the Great Basin. The Salton Sink is another closed basin within the Great Basin. The Great Basin Divide separates the Great Basin from the watersheds draining to the Pacific Ocean. The southernmost portion of the Great Basin is the watershed area of the Laguna Salada . The Great Basin's longest and largest river is the Bear River of 350 mi (560 km), and

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3168-630: The International Hydrographic Organization . The United Kingdom Hydrographic Office is one of the oldest, supplying a wide range of charts covering the globe to other countries, allied military organizations and the public. In the United States, the hydrographic charting function has been carried out since 1807 by the Office of Coast Survey of the National Oceanic and Atmospheric Administration within

3267-585: The Punjab region of India , for example, groundwater levels have dropped 10 meters since 1979, and the rate of depletion is accelerating. A lowered water table may, in turn, cause other problems such as groundwater-related subsidence and saltwater intrusion . Another cause for concern is that groundwater drawdown from over-allocated aquifers has the potential to cause severe damage to both terrestrial and aquatic ecosystems – in some cases very conspicuously but in others quite imperceptibly because of

3366-419: The U.S. Department of Commerce and the U.S. Army Corps of Engineers . Groundwater This is an accepted version of this page Groundwater is the water present beneath Earth 's surface in rock and soil pore spaces and in the fractures of rock formations . About 30 percent of all readily available fresh water in the world is groundwater. A unit of rock or an unconsolidated deposit

3465-653: The United States , and California annually withdraws the largest amount of groundwater of all the states. Underground reservoirs contain far more water than the capacity of all surface reservoirs and lakes in the US, including the Great Lakes . Many municipal water supplies are derived solely from groundwater. Over 2 billion people rely on it as their primary water source worldwide. Human use of groundwater causes environmental problems. For example, polluted groundwater

3564-465: The cold Great Basin and Oregon High Deserts in the north. The deserts can be distinguished by their plants: the Joshua tree and creosote bush occur in the hot deserts, while the cold deserts have neither. The cold deserts are generally higher than the hot and have more even spread of precipitation throughout the year. The climate and flora of the Great Basin are strongly dependent on elevation; as

3663-442: The hydraulic pressure of groundwater in the pore spaces of the aquifer and the aquitard supports some of the weight of the overlying sediments. When groundwater is removed from aquifers by excessive pumping, pore pressures in the aquifer drop and compression of the aquifer may occur. This compression may be partially recoverable if pressures rebound, but much of it is not. When the aquifer gets compressed, it may cause land subsidence,

3762-422: The mariner 's tools to avoid accident. The latter are best representations of the actual seabed, as in a topographic map, for scientific and other purposes. Trends in hydrographic practice since c. 2003–2005 have led to a narrowing of this difference, with many more hydrographic offices maintaining "best observed" databases, and then making navigationally "safe" products as required. This has been coupled with

3861-405: The vadose zone below plant roots and is often expressed as a flux to the water table surface. Groundwater recharge also encompasses water moving away from the water table farther into the saturated zone. Recharge occurs both naturally (through the water cycle ) and through anthropogenic processes (i.e., "artificial groundwater recharge"), where rainwater and/or reclaimed water is routed to

3960-534: The Basin and Range Province contains the Great Basin, but extends into eastern Oregon , southern Idaho , and the Colorado River watershed and the northwest corner of Arizona ). The Basin and Range region is the product of geological forces stretching the Earth's crust, creating many north–south trending mountain ranges. These ranges are separated by flat valleys or basins. These hundreds of ranges make Nevada

4059-563: The Fremont built small villages and grew crops like corn and squash. Seven hundred years ago, the Shoshone inhabited the area after the Fremont. They were hunter-gathers and lived in temporary homes to be able to follow animal herds and collect plants. Now, Shoshone descendants live in nearby areas. Other tribes in the area included the Ute , Mono , and Northern Paiute . All of the tribes speak

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4158-465: The Great Basin . Paleo-Indian habitation by the Great Basin tribes began as early as 10,000 B.C. . Archaeological evidence of habitation sites along the shore of Lake Lahontan date from the end of the ice age when its shoreline was approximately 500 feet (150 m) higher along the sides of the surrounding mountains. The Paleo-Indians were mainly hunters and hunted bison, the extinct mammoth, and extinct ground sloth. For housing, since they followed

4257-772: The Great Basin from the Sierra Nevada was Jedediah Strong Smith in 1827. Peter Skene Ogden of the British Hudson's Bay Company explored the Great Salt Lake and Humboldt River regions in the late 1820s, following the eastern side of the Sierra Nevada to the Gulf of California. Benjamin Bonneville explored the northeast portion during an 1832 expedition . The United States had acquired claims to

4356-745: The Great Basin into three ecoregions roughly according to latitude: the Northern Basin and Range ecoregion , the Central Basin and Range ecoregion , and the Mojave Basin and Range ecoregion . Great Basin wildlife includes pronghorn , mule deer , mountain lion , and lagomorphs such as black-tailed jackrabbit and desert cottontail and the coyotes that prey on them. Packrats , kangaroo rats and other small rodents are also common, and are predominantly nocturnal. Elk and bighorn sheep are present but uncommon. Small lizards such as

4455-473: The Great Basin's central Lahontan subregion. The hydrographic Great Basin contains multiple deserts and ecoregions , each with its own distinctive set of flora and fauna. The ecological boundaries and divisions in the Great Basin are unclear. The Great Basin overlaps four different deserts: portions of the hot Mojave and Colorado (a region within the Sonoran Desert ) Deserts to the south, and

4554-489: The United States . The "section" is somewhat larger than the hydrographic definition. The Great Basin culture area , or indigenous peoples of the Great Basin , is a cultural classification of indigenous peoples of the Americas and a cultural region located between the Rocky Mountains and the Sierra Nevada. The culture area covers approximately 400,000 sq mi (1,000,000 km), or just less than twice

4653-458: The actual shape of the bottom. The soundings selected from the raw source depth data for placement on the nautical chart are selected for safe navigation and are biased to show predominantly the shallowest depths that relate to safe navigation. For instance, if there is a deep area that can not be reached because it is surrounded by shallow water, the deep area may not be shown. The color filled areas that show different ranges of shallow water are not

4752-561: The age of groundwater obtained from different parts of the Great Artesian Basin, hydrogeologists have found it increases in age across the basin. Where water recharges the aquifers along the Eastern Divide , ages are young. As groundwater flows westward across the continent, it increases in age, with the oldest groundwater occurring in the western parts. This means that in order to have travelled almost 1000 km from

4851-614: The animals they were hunting, they had no permanent villages. The next group to live in the area was the Great Basin Desert Archaic, from approximately 9,000 to 1,500 years ago. They hunted animals like mule deer and antelope and gathered onions, wild rye, and pinyon pine nuts. Then, from 1,500 to 700 years ago, the Fremont lived in the area. Unlike the Paleo-Indians, who moved around to follow bison herds,

4950-405: The aquifer reduces the water pressure in the confining layer, causing it to compress from the weight of overlying geologic materials. In severe cases, this compression can be observed on the ground surface as subsidence . Unfortunately, much of the subsidence from groundwater extraction is permanent (elastic rebound is small). Thus, the subsidence is not only permanent, but the compressed aquifer has

5049-525: The aquifers are likely to run dry in 60 to 100 years. Groundwater provides critical freshwater supply, particularly in dry regions where surface water availability is limited. Globally, more than one-third of the water used originates from underground. In the mid-latitude arid and semi-arid regions lacking sufficient surface water supply from rivers and reservoirs, groundwater is critical for sustaining global ecology and meeting societal needs of drinking water and food production. The demand for groundwater

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5148-601: The area of the hydrographic Great Basin. The hydrographic Great Basin is a 209,162-square-mile (541,730 km) area that once drained internally. All precipitation in the region evaporated, sank underground or flowed into lakes (mostly saline). As observed by Fremont, creeks, streams, or rivers find no outlet to either the Gulf of Mexico or the Pacific Ocean . The region is bounded by the Wasatch Mountains to

5247-598: The atmosphere and fresh surface water (which have residence times from minutes to years). Deep groundwater (which is quite distant from the surface recharge) can take a very long time to complete its natural cycle. The Great Artesian Basin in central and eastern Australia is one of the largest confined aquifer systems in the world, extending for almost 2 million km . By analysing the trace elements in water sourced from deep underground, hydrogeologists have been able to determine that water extracted from these aquifers can be more than 1 million years old. By comparing

5346-510: The atmosphere through evapotranspiration , these salts are left behind. In irrigation districts, poor drainage of soils and surface aquifers can result in water tables' coming to the surface in low-lying areas. Major land degradation problems of soil salinity and waterlogging result, combined with increasing levels of salt in surface waters. As a consequence, major damage has occurred to local economies and environments. Aquifers in surface irrigated areas in semi-arid zones with reuse of

5445-420: The basin experiences a semi-arid or arid climate with warm summers and cold winters. However, some of the mountainous areas in the basin are high enough in elevation to experience an alpine climate . Due to the region's altitude and aridity, most areas in the Great Basin experience a substantial diurnal temperature variation . Hydrography Hydrography is the branch of applied sciences which deals with

5544-536: The best data available and will caveat its nature in a caution note or in the legend of the chart. A hydrographic survey is quite different from a bathymetric survey in some important respects, particularly in a bias toward least depths due to the safety requirements of the former and geomorphologic descriptive requirements of the latter. Historically, this could include echosoundings being conducted under settings biased toward least depths, but in modern practice hydrographic surveys typically attempt to best measure

5643-491: The current population growth rate. Global groundwater depletion has been calculated to be between 100 and 300 km per year. This depletion is mainly caused by "expansion of irrigated agriculture in drylands ". The Asia-Pacific region is the largest groundwater abstractor in the world, containing seven out of the ten countries that extract most groundwater (Bangladesh, China, India, Indonesia, Iran, Pakistan and Turkey). These countries alone account for roughly 60% of

5742-507: The data are interchangeable, but marine hydrographic data will be particularly directed toward marine navigation and safety of that navigation. Marine resource exploration and exploitation is a significant application of hydrography, principally focused on the search for hydrocarbons . Hydrographical measurements include the tidal , current and wave information of physical oceanography. They include bottom measurements, with particular emphasis on those marine geographical features that pose

5841-403: The depths observed, with the adjustments for navigational safety being applied after the fact. Hydrography of streams will include information on the stream bed, flows , water quality and surrounding land. Basin or interior hydrography pays special attention to rivers and potable water although if collected data is not for ship navigational uses, and is intended for scientific usage, it

5940-456: The distribution and movement of groundwater is hydrogeology , also called groundwater hydrology . Typically, groundwater is thought of as water flowing through shallow aquifers, but, in the technical sense, it can also contain soil moisture , permafrost (frozen soil), immobile water in very low permeability bedrock , and deep geothermal or oil formation water. Groundwater is hypothesized to provide lubrication that can possibly influence

6039-684: The down-faulted basins between ranges and created relatively flat lacustrine plains from Pleistocene lake beds of the Great Basin. For example, after forming about 32,000 years ago , Lake Bonneville overflowed about 14,500 years ago in the Bonneville Flood through Red Rock Pass and lowered to the "Provo Lake" level (the Great Salt Lake , Utah Lake , Sevier Lake , Rush Lake , and Little Salt Lake remain). Lake Lahontan , Lake Manly , and Lake Mojave were similar Pleistocene lakes. The Great Basin physiographic section of

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6138-514: The east, the Sierra Nevada and Cascade Ranges to the west, and the Snake River Basin to the north. The south rim is less distinct. The Great Basin includes most of Nevada , half of Utah , substantial portions of Oregon and California , and small areas of Idaho , Wyoming , and Baja California, Mexico . The term "Great Basin" is slightly misleading; the region comprises many small basins. The Great Salt Lake , Pyramid Lake , and

6237-732: The eastern regions of the 1848 California Gold Rush , with its immigrants crossing the Great Basin on the California Trail along Nevada's Humboldt River to Carson Pass in the Sierras. The Oregon Territory was established in 1848 and the Utah Territory in 1850. In 1869 the First transcontinental railroad was completed at Promontory Summit in the Great Basin. Around 1902, the San Pedro, Los Angeles and Salt Lake Railroad

6336-402: The elevation increases, the temperature decreases and precipitation increases. Because of this, forests can occur at higher elevations. Utah juniper / single-leaf pinyon (southern regions) and mountain mahogany (northern regions) form open pinyon-juniper woodland on the slopes of most ranges. Stands of limber pine and Great Basin bristlecone pine ( Pinus longaeva ) can be found in some of

6435-581: The entire world, and produced over 130,000 charts annually, of which about half were sold. The word hydrography comes from the Ancient Greek ὕδωρ ( hydor ), "water" and γράφω ( graphō ), "to write". Large-scale hydrography is usually undertaken by national or international organizations which sponsor data collection through precise surveys and publish charts and descriptive material for navigational purposes. The science of oceanography is, in part, an outgrowth of classical hydrography. In many respects

6534-495: The equivalent of contours on a topographic map since they are often drawn seaward of the actual shallowest depth portrayed. A bathymetric chart does show marine topology accurately. Details covering the above limitations can be found in Part ;1 of Bowditch's American Practical Navigator . Another concept that affects safe navigation is the sparsity of detailed depth data from high resolution sonar systems. In more remote areas,

6633-494: The establishment of the United Kingdom Hydrographic Office , Royal Navy captains were responsible for the provision of their own charts. In practice this meant that ships often sailed with inadequate information for safe navigation, and that when new areas were surveyed, the data rarely reached all those who needed it. The Admiralty appointed Alexander Dalrymple as Hydrographer in 1795, with

6732-404: The extended period over which the damage occurs. The importance of groundwater to ecosystems is often overlooked, even by freshwater biologists and ecologists. Groundwaters sustain rivers, wetlands , and lakes , as well as subterranean ecosystems within karst or alluvial aquifers. Not all ecosystems need groundwater, of course. Some terrestrial ecosystems – for example, those of

6831-407: The extent, depth and thickness of water-bearing sediments and rocks. Before an investment is made in production wells, test wells may be drilled to measure the depths at which water is encountered and collect samples of soils, rock and water for laboratory analyses. Pumping tests can be performed in test wells to determine flow characteristics of the aquifer. The characteristics of aquifers vary with

6930-472: The geology and structure of the substrate and topography in which they occur. In general, the more productive aquifers occur in sedimentary geologic formations. By comparison, weathered and fractured crystalline rocks yield smaller quantities of groundwater in many environments. Unconsolidated to poorly cemented alluvial materials that have accumulated as valley -filling sediments in major river valleys and geologically subsiding structural basins are included among

7029-404: The globe includes canals redirecting surface water, groundwater pumping, and diverting water from dams. Aquifers are critically important in agriculture. Deep aquifers in arid areas have long been water sources for irrigation. A majority of extracted groundwater, 70%, is used for agricultural purposes. In India, 65% of the irrigation is from groundwater and about 90% of extracted groundwater

7128-416: The ground surface (within a couple of hundred metres) and have some recharge by fresh water. This recharge is typically from rivers or meteoric water (precipitation) that percolates into the aquifer through overlying unsaturated materials. In general, the irrigation of 20% of farming land (with various types of water sources) accounts for the production of 40% of food production. Irrigation techniques across

7227-516: The higher ranges. In riparian areas with dependable water cottonwoods ( Populus fremontii ) and quaking aspen ( Populus tremuloides ) groves exist. Because the forest ecosystem is distinct from a typical desert, some authorities, such as the World Wildlife Fund , separate the mountains of the Great Basin desert into their own ecoregion: the Great Basin montane forests . Many rare and endemic species occur in this ecoregion, because

7326-597: The individual mountain ranges are isolated from each other. During the Last Glacial Period , the Great Basin was wetter. As it dried during the Holocene epoch, some species retreated to the higher isolated mountains and have high genetic diversity. Other authorities divide the Great Basin into different ecoregions, depending on their own criteria. Armen Takhtajan defined the "Great Basin floristic province". The U.S. Environmental Protection Agency divides

7425-467: The largest single watershed is the Humboldt River drainage of roughly 17,000 sq mi (44,000 km). Most Great Basin precipitation is snow, and the precipitation that neither evaporates nor is extracted for human use will sink into groundwater aquifers , while evaporation of collected water occurs from geographic sinks . Lake Tahoe , North America's largest alpine lake , is part of

7524-518: The local hydrogeology , may draw in non-potable water or saltwater intrusion from hydraulically connected aquifers or surface water bodies. This can be a serious problem, especially in coastal areas and other areas where aquifer pumping is excessive. Subsidence occurs when too much water is pumped out from underground, deflating the space below the above-surface, and thus causing the ground to collapse. The result can look like craters on plots of land. This occurs because, in its natural equilibrium state,

7623-402: The making of charts to aid navigation, by individual mariners as they navigated into new waters. These were usually the private property, even closely held secrets, of individuals who used them for commercial or military advantage. As transoceanic trade and exploration increased, hydrographic surveys started to be carried out as an exercise in their own right, and the commissioning of surveys

7722-411: The measurement and description of the physical features of oceans , seas , coastal areas , lakes and rivers , as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activities, including economic development, security and defense, scientific research, and environmental protection. The origins of hydrography lay in

7821-535: The most mountainous state in the country. The Great Basin's two most populous metropolitan areas are the Reno-Sparks metropolitan area to the west and the Wasatch Front to the east (with the latter being significantly more populous than the former). The region between these two areas is sparsely populated, but includes the smaller cities of Elko , Ely , Wendover , West Wendover , and Winnemucca . To

7920-412: The most productive sources of groundwater. Fluid flows can be altered in different lithological settings by brittle deformation of rocks in fault zones ; the mechanisms by which this occurs are the subject of fault zone hydrogeology . Reliance on groundwater will only increase, mainly due to growing water demand by all sectors combined with increasing variation in rainfall patterns . Groundwater

8019-404: The movement of faults . It is likely that much of Earth 's subsurface contains some water, which may be mixed with other fluids in some instances. Groundwater is often cheaper, more convenient and less vulnerable to pollution than surface water . Therefore, it is commonly used for public drinking water supplies. For example, groundwater provides the largest source of usable water storage in

8118-903: The north are; in California Susanville , in Oregon Burns and Hines , in Idaho Malad and in Wyoming Evanston . To the south are Cedar City , Tonopah , and Bishop and the very southern area of the basin has the communities of Pahrump , Palmdale , Victorville , and Palm Springs . Interstate Highways traversing the Great Basin are Interstate 80 (I-80) and I-15 , and I-70 and I-84 have their respective endpoints within its boundaries. Other major roadways are U.S. Route 6 (US 6), US 50 , US 93 , US 95 and US 395 . The section of US 50 between Delta, Utah , and Fallon, Nevada ,

8217-502: The only available depth information has been collected with lead lines. This collection method drops a weighted line to the bottom at intervals and records the depth, often from a rowboat or sail boat. There is no data between soundings or between sounding lines to guarantee that there is not a hazard such as a wreck or a coral head waiting there to ruin a sailor's day. Often, the navigation of the collecting boat does not match today's GPS navigational accuracies. The hydrographic chart will use

8316-671: The open deserts and similar arid environments – exist on irregular rainfall and the moisture it delivers to the soil, supplemented by moisture in the air. While there are other terrestrial ecosystems in more hospitable environments where groundwater plays no central role, groundwater is in fact fundamental to many of the world's major ecosystems. Water flows between groundwaters and surface waters. Most rivers, lakes, and wetlands are fed by, and (at other places or times) feed groundwater, to varying degrees. Groundwater feeds soil moisture through percolation, and many terrestrial vegetation communities depend directly on either groundwater or

8415-470: The other two thirds. Groundwater provides drinking water to at least 50% of the global population. About 2.5 billion people depend solely on groundwater resources to satisfy their basic daily water needs. A similar estimate was published in 2021 which stated that "groundwater is estimated to supply between a quarter and a third of the world's annual freshwater withdrawals to meet agricultural, industrial and domestic demands." Global freshwater withdrawal

8514-683: The percolated soil moisture above the aquifer for at least part of each year. Hyporheic zones (the mixing zone of streamwater and groundwater) and riparian zones are examples of ecotones largely or totally dependent on groundwater. A 2021 study found that of ~39 million investigated groundwater wells 6-20% are at high risk of running dry if local groundwater levels decline by a few meters, or – as with many areas and possibly more than half of major aquifers  – continue to decline. Fresh-water aquifers, especially those with limited recharge by snow or rain, also known as meteoric water , can be over-exploited and depending on

8613-467: The public and to other nations as well. In 1829, Rear-Admiral Sir Francis Beaufort , as Hydrographer, developed the eponymous Scale , and introduced the first official tide tables in 1833 and the first " Notices to Mariners " in 1834. The Hydrographic Office underwent steady expansion throughout the 19th century; by 1855, the Chart Catalogue listed 1,981 charts giving a definitive coverage over

8712-423: The same terms as surface water : inputs, outputs and storage. The natural input to groundwater is seepage from surface water. The natural outputs from groundwater are springs and seepage to the oceans. Due to its slow rate of turnover, groundwater storage is generally much larger (in volume) compared to inputs than it is for surface water. This difference makes it easy for humans to use groundwater unsustainably for

8811-416: The source of recharge in 1 million years, the groundwater flowing through the Great Artesian Basin travels at an average rate of about 1 metre per year. Groundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer . This process usually occurs in

8910-968: The southern " panhandle ". The Great Basin Province was defined by botanist Armen Takhtajan to extend well beyond the boundaries of the hydrographically defined Great Basin: it includes the Snake River Plain , the Colorado Plateau , the Uinta Basin , and parts of Arizona north of the Mogollon Rim . The Great Basin physiographic section is a geographic division of the Basin and Range Province defined by Nevin Fenneman in 1931. The United States Geological Survey adapted Fenneman's scheme in their Physiographic division of

9009-497: The subsurface. The high specific heat capacity of water and the insulating effect of soil and rock can mitigate the effects of climate and maintain groundwater at a relatively steady temperature . In some places where groundwater temperatures are maintained by this effect at about 10 °C (50 °F), groundwater can be used for controlling the temperature inside structures at the surface. For example, during hot weather relatively cool groundwater can be pumped through radiators in

9108-615: The territory north of the 42nd parallel via the 1819 Adams–Onís Treaty with Spain and 1846 Oregon Treaty with Britain. The US gained claims to most of the rest of the Great Basin via the 1848 Mexican Cession . The first non-indigenous settlement was in 1847 in the Great Salt Lake Valley, leading to the first American religious settlement effort of the Mormon provisional State of Deseret in 1849 in present-day Utah and northern Nevada. Later settlements were connected with

9207-408: The unavoidable irrigation water losses percolating down into the underground by supplemental irrigation from wells run the risk of salination . Surface irrigation water normally contains salts in the order of 0.5 g/L or more and the annual irrigation requirement is in the order of 10,000 m /ha or more so the annual import of salt is in the order of 5,000 kg/ha or more. Under

9306-519: The world's liquid fresh water is groundwater. Global groundwater storage is roughly equal to the total amount of freshwater stored in the snow and ice pack, including the north and south poles. This makes it an important resource that can act as a natural storage that can buffer against shortages of surface water , as in during times of drought . The volume of groundwater in an aquifer can be estimated by measuring water levels in local wells and by examining geologic records from well-drilling to determine

9405-420: The world's total groundwater withdrawal. Groundwater may or may not be a safe water source. In fact, there is considerable uncertainty with groundwater in different hydrogeologic contexts: the widespread presence of contaminants such as arsenic , fluoride and salinity can reduce the suitability of groundwater as a drinking water source. Arsenic and fluoride have been considered as priority contaminants at

9504-402: Was constructed in the lower basin and Mojave Desert for California-Nevada rail service to Las Vegas, Nevada. The climate varies throughout the Great Basin by elevation, latitude, and other factors. Higher elevations tend to be cooler and receive more precipitation. The western areas of the basin tend to be drier than the eastern areas because of the rain shadow of the Sierra Nevada . Most of

9603-451: Was increasingly done by governments and special hydrographic offices. National organizations, particularly navies , realized that the collection, systematization and distribution of this knowledge gave it great organizational and military advantages. Thus were born dedicated national hydrographic organizations for the collection, organization, publication and distribution of hydrography incorporated into charts and sailing directions. Prior to

9702-402: Was probably around 600 km per year in 1900 and increased to 3,880 km per year in 2017. The rate of increase was especially high (around 3% per year) during the period 1950–1980, partly due to a higher population growth rate, and partly to rapidly increasing groundwater development, particularly for irrigation. The rate of increase is (as per 2022) approximately 1% per year, in tune with

9801-421: Was unintentionally introduced, forms a critical portion of their diets. Feral horses ( mustangs ) and feral burros are highly reproductive, and ecosystem-controversial, alien species. Most of the Great Basin is open range and domestic cattle and sheep are widespread. The Great Basin includes valleys, basins, lakes and mountain ranges of the Basin and Range Province . The basin and range topography

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