Land surface water depression formed a wider waters. Causes can be divided into construction by Lake, Crater Lake, glacial lakes, dammed lake, b055 , artificial lake. By lake water salinity level can be divided into saltwater and freshwater.
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hú pō
Lake of the general. Large inland stagnant water, the expansion of part of the river, blocking into the reservoir or intermittent or has previously been covered with water in the lake bed
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No. 3
Lake of the general. Wang Tao, etc. "Our lake": "lake can be divided into freshwater lakes, lagoons and salt three." Wang Tao, etc. "Our lake": "Lake is a lake, the lake and the water contains minerals, organic matter and biological composed of paradox. "
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No. 4
Lakes (-pō): land surface water depression formed a wider waters. Causes can be divided into construction by Lake, Crater Lake, glacial lakes, dammed lake, b055 lake, artificial lake. By lake water salinity level can be divided into saltwater and freshwater.
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Definitions
Water on land depressions formed ﹑ ﹑ commutation waters relatively slow wide body of water. In geological tectonic movement ﹑ ﹑ glaciation, such as river erosion, surface formation of many depressions, water into the lake. Reservoir open pit depressions formed by damming the water and also is out of the lake, said the artificial lake. Lakes because of unusually slow and commutation Unlike rivers, the ocean does not occur because of the direct link which is different from the sea. Under the impact of natural and geographical conditions basin, the lake water and lake water ﹑ matter interaction, mutual restraint, so that the lake evolving. Lake called mixed, multi dialect title. China used to use the pool Pei ﹑ ﹑ ﹑ Ze Hai Dang ﹑ ﹑ ﹑ bubble Park lake ﹑ ﹑ lakes are all wrong and Noel's nickname. Inland basin slowly flowing or stagnant bodies of water. Strict distinction between the definition of lakes, ponds, swamps, rivers, and other non-marine water body has not been fully established, however, generally believed that the river sport faster; within the swamp grow a lot of grass, trees or shrubs; ponds smaller than lakes. By definition geology, lakes are temporary bodies of water. In the global hydrological cycle, the role of small freshwater lakes, the water is only 0.009% of its total global water, still less than 0.0075% of the total fresh water on land. However, fresh water is more than 98% of the water available for use. The world's total of 125,000 cubic kilometers of freshwater lakes (30,000 cubic miles) of fresh water about 4/5 of the Great Lakes in the store at 40. Although the lakes around the world, but the lake water in North America, Africa and Asia accounted for 70 percent of the world's total water, and less the rest of the continent lakes. Scientific research is the lake limnology, lake limnology homemade formation process according to the classification of lakes and lake. Particularly large basin by tectonic crustal movement that formed in the late Miocene broad and gentle crustal movement across the South and South-Eastern Europe led to the majority of the inland sea, separated, and now there are remnants of inland water bodies Caspian Sea, the Aral Sea as well as numerous small lakes. Constructed on land can rise hindered the formation of a natural river basin, the Great Basin of South Australia, some of Africa's lakes and mountains of northern Lake Champlain is the product of the United States this role. In addition, the formation of the basin fault also plays an important role in two of the world's deepest lake Baikal and Lake Tanganyika basin is the graben complex formation. These two lakes and other graben lake, those lakes are modern times and the Red Sea in the East African Rift Valley lakes especially in the oldest. Volcanic activity can form various types of lake, located in the main types of existing remnants of the caldera or crater lake. Oregon's Crater Lake is a typical example. Substances can be blocked by a landslide lake formed valley, but this may be a temporary lake. Glaciation can form a large number of lakes in the northern hemisphere is such a role in the formation of many lakes, the lake is ice retreat during the formation of the mechanical abrasive action, or due to the ice sheet boundary from ice damming. Moraine formed on the lake basin plays an important role in New York's Finger Lakes (Finger Lakes) is the terminal moraine dammed made. There are several ways fluvial basin formation, the most important role of a waterfall, blocking tributary sediment deposition river delta, upstream sediment transport due to the tidal action of blocking the river shape changes (ie, oxbow lakes and levee Lake) and the dissolution of groundwater lakes formed. Some coastal areas, coastal currents can accumulate large amounts of sediment blocking the river. In addition, wind, movement activities and meteorites are likely to form a lake. Lake sediments is dominated by detrital material (clay, silt and sand), organic debris, chemical precipitation or a mixture of these substances formed. The relative amount of each depends on the natural conditions of sediments, the climate and the relative age of the lake basin. The main chemical sediments in lakes calcium, sodium, magnesium carbonate, dolomite, gypsum, rock salt and sulfate. Lakes contain high concentrations of sodium is called Bitter Lake, containing sodium carbonate alkali lake called Lake. Since different chemical nature basin erosion products, therefore, the world is also changing the chemical composition of the lake, but in most cases, the main component is similar. Lake water is defined as the total salt concentration of ions, the amount is usually based on the salt of sodium, potassium, magnesium, calcium, carbonate, silicate, and to calculate the concentration of halide. Inland Sea has a high salt content. Great Salt Lake in Utah salt volume of about 200 000 milligrams per liter. The maximum density of water temperature varies with depth, most of the lake close to the maximum density temperature 4 ℃ (39 ℉), the formation of ice near 0 ℃, with surface cooling down to 4 ℃, the vertical mixing occurs when the lake . If the density increases with depth, the lake is considered stable; if the density decreases with depth, indicates the existence of an unstable condition lake. Since the cooling and warming processes, surface water layer density increases, so that the water mass sinking, causing mixing, a phenomenon known as lake water circulation or convection. Lakes calorie estimates include the following major factors ︰ net incoming solar radiation, the net exchange from the lake surface and atmospheric scattering of long-wave radiation, surface boundary surface sensible heat and latent heat transport processes, as well as through river runoff, precipitation, groundwater inflow and outflow of heat, geothermal heat conduction and kinetic energy consumption. Water movement caused mainly ︰ wind power, hydraulic gradient and result in a horizontal or vertical density gradients caused by force. Lake the wind energy to the lake, causing the water sports. Hydraulic effect caused by the flow out of the lake. Lake internal pressure gradient and density gradient from the water, sediment concentration or mass concentration of dissolved due to changes in the water can cause movement. Lake stream is the result of interaction between the various forces, but in many cases a few specific force plays a dominant role. When there is no horizontal pressure gradients, no friction, horizontal flow by the Coriolis force affecting the northern hemisphere will tend to the right. When the pressure gradient from the dominant role, then this force and the Coriolis force combine to form the so-called geostrophic flow. This only occurs in large lakes. Due to the pressure gradient wind action or inclination to make the water flow generated gradient. Lake caused by the wind flow is most common. In a large deep-water lake, in theory, the partial flow along the surface flow of wind to the right 45 °, and the deep, flow gradually weakened, and further bias to the right. Wind effects can not reach the depth below the water flow in the direction opposite to the wind direction. For the mid-latitude large and deep lakes such depth of about 100 meters (328 feet). Langmuir (Langmuir) is a small circulation circulation phenomenon caused by the wind on the water, when the wind blows, you can observe many parallel to the surface ripples generated, and can be extended to a considerable distance, appeared at a relatively sinking corrugated, corrugated between the relative increase in the circulation of this phenomenon can also be mixed by the lake in the heat sink caused. Lake waves and more wind caused by the lake. Wind on a calm lake, first make vast lake fluctuations and ripple formation have more rules, and to a lesser extent, the expansion of the capillary waves in the same direction. The increase in wave height and wind speed, duration of action and was blown away function. However, even in the largest lakes, it does not appear the phenomenon of ocean waves. Lake with waves and waves propagate along the direction perpendicular to the wind direction peak, if more than four times the wavelength of depth, velocity is approximately equal to the square root of the product of the depth and gravity; square root if the water depth is large, the velocity and wavelength. Due to persistent pressure gradient caused by wind and lake tilt, when the external force will cause the water flow is stopped, so that the lake restoration. This process is called static vibration. The basic static vibration of a single section, but the occurrence of harmonics, it can also be a multi-section. Along the long axis of the wind blowing narrow lake, then more appear longitudinal static vibration, while across the narrow lake is mostly static lateral vibration occurs. Interior lakes static vibration is caused by thermal stratification. Lake water is obtained primarily through runoff into the lake, the lake precipitation and groundwater. Lakes of Lake illiquid (no surface or underground exit) and circulation lake (there are surface or underground exit) two. Lake water does not flow in the evaporation leads to increased consumption of water salinity, circulation lake by surface or underground water runoff flows away, the net difference between the amount of revenue and expenditure of the lake, with periodic or aperiodic changes into and out of traffic and traffic changes, this difference causes a change in the water level. Water level usually rises during the rainy season or later, evaporation season decline. In the main supply meltwater lakes, water level changes both with hot season and corresponding with the rainy season.
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Distributed
World Lake is widely distributed, many Chinese lakes, covering an area greater than one square kilometer in about 2300, with a total area of over 71,000 square kilometers. Another said of 2848, an area of 83,400 square kilometers. Qinghai Lake area of over 4000 square kilometers, is China's largest lake. Tibet Namco, the lake elevation of 4718 meters in the world, the lake area of 1000 square kilometers of lakes, is the highest elevation lakes. Located on Mt Tianchi (Chinese Korean border lake), water depth of 373 meters, is China's deepest lake. Kranjcar Yi Salt Lake Qaidam Basin, with rich reserves of salt lakes known to the world.
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Lake
Refers to the storage Carolina lake surface depressions. Flat topography and morphology of the original lake bottom, largely depends on the lake causes. According basin formation factors play a leading role, the lake summarized into the following categories: structural basin by the tectonic movement of the crust (such as faults and folds) formed; due to growth and decline or retreat of glaciers and ice breaking ice crater lake formed after the eruption of the dormant crater;; water flow or water erosion formed by dissolution; landslides or volcanic eruptions ﹑ landslide blocked the valley so that the material forming the lake basin or valley uneven heating glacial lake formed into the lake; wind erosion formed by the wind blowing into the lake; Additionally, there are a large meteorite hit the ground, such as the formation of the meteorite lake.
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Lake evolution
Once the lake formed, by external factors and the continuing role of natural internal processes and a variety of evolving. Into rivers carry a lot of sediment and biological debris deposited in the lake year after year, the lake gradually silted into the land, or with the development of the coastal zone of aquatic plants, and gradually become swamps; under dry weather conditions inland lakes due to climate variability, meltwater reduced groundwater levels drop so the water supply is insufficient to compensate for evaporation losses, often caused by dry lake retreat, or salts accumulate in the basin concentrated, water is increasingly salinization eventually become playa Some lakes due to export cut, the lake outflow and dry. In addition, due to crustal movement at climate change and changes in other factors formed lakes, lakes undergo repeated reduction and enlargement process, regardless of which way the natural evolution of the lake through the results will eventually die.
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Lakes morphological parameters
The decision to form the lake in its genesis and development process. Average depth of tectonic lake shore steep, but with the change of the lake, and some tectonic lake some features may gradually disappear. Crater lake is usually a small area, great depth. As China Tianchi area of only 9.8 square kilometers, and a depth of 373 meters. Lake morphology affect the distribution of physical and chemical properties of water and aquatic organisms. Lakes morphological parameters are: area, generally refers to the highest water level of the lake area. Volume refers to the volume of water storage basin, which varies with the water level. Length, measured along the lake side furthest away from the shortest distance between two points on the shore of the lake based on morphology, may be linear length, it could be a line length. Width, maximum width and the average width of the former is the largest relative distance between the two sides is approximately perpendicular to the direction of the length of the line, which is the area divided by length. Length of coastline, the highest level refers to the length of the lake at the edge. Shoreline development factor, referring to the ratio of the length of the shoreline of the lake area equal to the circumference of a circle. Lakes recharge coefficient, the ratio of the area of the lake basin and the lake area. Lake islands rate, the ratio of the total area of the lake islands and lakes area. The maximum depth of the vertical distance, the maximum water level and the deepest point of the lake. The average depth of the lake volume and the corresponding quotient of the lake area. Lakes quantitative morphological parameters characterizing various aspects of lake morphology, lakes (reservoirs) ﹑ planning design and management of basic data can also be used to compare the hydrological characteristics of the different lakes.
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Lake classification
Tectonic lake: the lake basin crust constructed role in the formation of internal forces formed by the reservoir. Its characteristics are shaped narrow lake, depth and clarity, such as Dianchi Lake, Yunnan Erhai and Fuxian plateau; Qinghai Lake, Xinjiang Kanas Lake. (Another example is the famous Great Rift Valley along Lake Malawi, Lake Tanganyika, Lake Victoria) tectonic lake generally have very distinct morphological characteristics, namely the steep lakeshore development and construction lines along the lake are generally deep. Also often arranged in a series of construction lines constructed in accordance with lakes. Crater Lake: Department of volcanic eruptions of water from the mouth after hibernation, its shape is round or oval, steep lakeshore, lake unfathomable, such as Mt Tianchi depth of 373 meters, is China's first deepwater s lakes. Lake: the volcano's magma, landslides caused by earthquakes and landslides and mudslides caused by glaciers, such as congestion bed, cut off the water outlet, the upper part of the river water into the lake, such as the Five Jingpohu so on. Karst lake: by dissolution of carbonate formation after long-term water formed karst depressions, sinkholes and other karst funnel or blocked, the lake formed by the catchment, such as Guizhou Weining Caohai. Weining has a view of the sea floor suburbs, CASTLE overlooking the lake and saw Bibowanqing, alluring; lake on the island Chui Court exquisite, flowers and trees, has said the water park. Glacial lake: the potholes and clogged moraine glacial valley lakes formed by water erosion formed by the glaciers digging. If Fukang Tianchi, also known as the Jade Pool, legend has it that the Queen Mother bathing place. Great Lakes, Finland, Sweden, many lakes. Aeolian Lake: Desert dune depressions dive below the surface of the sand dunes around it by adding together seepage lakes, such as Dunhuang near Crescent Lake, surrounded by sand hills, water resembles a crescent moon, clear as the emerald lake . River into the lake: swing and diversion of rivers and lakes formed. It can be divided into three categories: First, because the river swing, its natural water retention dike to plug into the tributaries and lakes. As Poyang Lake, Dongting Lake, Jianghan Lakes (Yunmengze area), Taihu. Second, because the river itself is congestion foreign sediment, water vent poor retention of water into the lake. Nansi etc. as Sulu border. Third, the river cut Bay straightened abandoned river oxbow lake formed. Such as Inner Mongolia Wuliangsuhai. Sea into the lake: As part of the bay makes sedimentation and marine division is made, often referred to as lagoons, such as the Caspian Sea, West Lake in Hangzhou, Ningbo East Lake. About a few years ago, the West Lake is a shallow bay, and later due to the Qiantang tidal entrained sediment deposited in the bay near the mouth constantly, so the bay and ocean waters completely separated from the sea by gradually fade before the formation of today's West. Lagoon: a sandbar because the Gulf is closed and turned into the lake, it is generally in the sea. These lakes could have been the Gulf, and later at sea in the Gulf due to sediment deposition, resorted to the sea forming a sandbar, and then separating the bay and ocean, and thus become lakes. "Purging" the word rare in modern Chinese, is a halogen salt land of Italy, due to the more common in Japanese, and made a lot of people thought it was the characters, it is not. Because many people do not know, "diarrhea" word, so often regarded it wrong became "lagoon." 1. Flood control features: the lagoon drainage can vent area, which rarely floods. 2. Coastal protection functions: there on the sandbar outside the storm surge barrier to prevent erosion of coastal erosion. 3. Natural farms: lagoon fish, shrimp, shellfish and crab nurseries, but also close to the natural farm fishermen. 4. Because there are often outside the lagoon sandbar as breakwaters, the inner calm, it can sometimes be converted into artificial harbor Famous lagoon: Chiku Lagoon, Gezuoneihai, Kohler lagoon
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Water sports
By movement elements with characteristic time of change into periodic motion, such as lakes lake wave ripples waves ﹑ ﹑ wave ripples generated along the lake flows; aperiodic sports such as rafting ﹑ throughput streaming. Press the mixture into movement pattern changes in water ﹑ ﹑ ﹑ lake current wave and the wave ripples and so on. Vertical position by movement occurred in the lake can be divided into surface movement and internal movement. Various forms of exercise often affect each other, combined with each other. Water sports in the form of a layer structure depends on the lake, the internal density distribution, the force of the cyclical nature ﹑ ﹑ ﹑ lasted spatial distribution, basin morphology and other factors. After the external force stops, the water movement hindered by viscous friction force and effect and lake borders gradually decay, and, eventually disappear.
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Lake level
Variation divided by two kinds of periodic and aperiodic, periodic changes in water supply depends. Precipitation recharge lakes, the highest water level during the rainy season, dry season minimum; snow melt water supply mainly highland lakes, the highest level in the summer, the lowest in the winter; groundwater recharge lakes, the water level changes are generally not. Some lakes due to tidal lake breeze ﹑ ﹑ such as freezing and melting snow day impact of cyclical changes in Lake Victoria in Africa because of the lake breeze effect, mean water level is higher than daytime nighttime 9.9 cm. Aperiodic variations are often due to wind pressure ﹑ ﹑ caused by heavy rain. Taihu Lake in China continued strong northeasterly winds caused by changes in the role of water in the same period, to make the water level rose 1.1 meters upwind shore, on the leeward shore water level dropped 0.75 meters. In addition, due to changes in the earth's crust cut ﹑ human activities such as power generation and irrigation also allows the water level under the Hukou river changed greatly.
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Lake thermal characteristics
Lake absorb solar energy, heat gains, while ﹑ water through surface evaporation and surface active radiation convection heat exchange with the atmosphere, such as the loss of heat. Heat transport and exchange of lakes, lake heat balance equation can be expressed and calculated (see lake thermal dynamics). Since some elements of the heat balance of the lake (such as lakes evaporation rate) is not easy to accurately measured, and thus often used to express the lake water temperature thermal dynamics. Solar radiation is the major surface of the water temperature increases, the lower the water temperature of the water is mainly caused by convection and turbulent mixing. Water can also be caused due to different temperature density differences, resulting in lower water layer convection loop unstable, convective circulation reached at a depth of more water converge. Wind disturbance can produce shallow lakes with temperature phenomena in any season; while the wind disturbance for the deepwater lakes only involves the upper lake, which in the upper and lower vertical produce different temperature distribution. ﹑ Water temperature variation between the upper layer of the middle layer is called a sharp thermocline. Water temperature has a certain annual and diurnal variation that is most obvious in the lake surface, weakened with increasing depth. The freezing point of water depends on salinity and hydrostatic pressure. In addition, the lake freezes also concerned with the wind, in the same climatic conditions, different lake or a different part of the lake, freezing phenomenon is not simultaneously (see lake ice conditions).
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Radiation and optical characteristics of the lake
Determine the radiation characteristics of the lake water temperature, affecting the distribution of physical and chemical properties of the lake, and the lake ﹑ various biological reproduction and growth and development are also related to the radiation characteristics of the lake. Shot in the sunlight portion of the lake into the water, and some is reflected. Sunlight entering the water body partially absorbed, some scattered, even in shallow lakes are only a small part of the lake is absorbed by the water layer. Lake incident sunlight most significant portion of the water absorbed by the upper layer, only 1 to 30% aqueous layer reached a depth of 1 m, 5 m deep penetration of only 0 to 5%, 10 m deep into the at less than 1%. Water absorption of solar light scattering ability of sunlight and water, various suspended solids and particle size of the number, the greater the mass, the more the suspension ﹑ particles absorb and scatter light, the stronger, while the scattering component to the surface smaller. The depth of light penetration into the water, with the increasing turbidity of the water is reduced (see lake optical phenomenon). In turbid lake light only a few meters deep, and in the clear water, the 200-meter-deep water can still exist faint light.
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Chemical characteristics of the lake
According to the water contained in the different types of major ions, the lake water is usually divided into carbonate water ﹑ sulfate and chloride water. Chemical Type lake water reflects the process of change with changes in water salinity caused. Salinity of the lake region disparity, there are seasonal changes. China's freshwater lakes ﹑ mainly concentrated in the Yangtze River Plain, the salinity of the lake is generally 150 to 500 mg / l. Lagoons and salt lakes are mainly distributed in the Qinghai-Tibet Plateau ﹑ Inner Mongolia and Xinjiang regions. Most of the salinity of the lagoon from 1 to 20 g / l concentration of the increasing trend. Salt Lake mineralization is generally 300 g / l, chemical type complete. Dissolved nutrients and organic matter in the oxygen content of bio-gas ﹑ free carbon dioxide, water, nitrogen, phosphorus, silicon, potassium, zinc, iron and other aquatic organisms in the lake has a special significance.
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Lake resources
The lake is an important component of the global water resources on Earth lakes (including saltwater and freshwater ﹑ Salt Lake) with a total area of about 2,058,700 square kilometers, with a total of about 176,400 cubic kilometers of water, which accounts for about 52 percent of freshwater reserves, about the world's fresh water reserves of 0.26%. Lake can be constantly updated, the update of different lakes varies, depending on the length of the lake to replace its volume and the lake into Lake ﹑ annual runoff. Chinese Poyang Lake water updated only once 9.6 days, updated every Taihu Lake about 299 days. Freshwater lakes is very uneven geographical distribution of reserves, ﹑ Baikal Lake Tanganyika and Lake Superior Great Lakes saved 40 of the world's fresh water accounts for the world's total freshwater lakes 4/5. China's total freshwater Dongting Lake, Poyang Lake ﹑ ﹑ ﹑ Taihu, Chaohu and Hongze Lake is approximately 55.3 billion m. Vessels conducive lake is an important part of the waterway transport. Lakes rich in fish, shrimp ﹑ ﹑ ﹑ crab shell, producing Lin Ling ﹑ ﹑ ﹑ lotus gravy and reeds, is an important source of Fisheries and light materials. Lake as a tourist resource, is increasingly valued. Irrational exploitation of lake resources will cause attenuation of fishery resources in the lake, the lake area is reduced and marsh land around the lake and other adverse consequences.
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Encyclopedia
hupo Lake lake Relatively closed depressions in the accumulation of water on land. This relatively closed depressions called the lake. Lakes basin is a comprehensive body of water interacting with the movement, because the lake exchange of matter and energy, resulting in a series of physical, chemical and biological processes, which constitute a unique lake ecosystem. On the lake with a total area of about 2,058,700 square kilometers of Earth, accounting for 1.5% of the total area of the continent. A total of about 176,400 cubic kilometers of water lakes, which accounted for about 52 percent of freshwater storage. Due to historical reasons and habits, call around China for many lakes, such as Lake Park, Ze, lake, sea (son), Noel, Nao, wrong, Chaka, Chur, Kule, pool, swing, Waterfront, pond, lake, and bubbles. Causes and types according to Genesis, the lake can be broadly divided into the following types. Lake directly by the tectonic structure of the movement (fracture, fold, graben, etc.) so that the ground water from lakes depression. Such lakes quay steep greater depth. Glacial lake of glacial erosion and sedimentation to form lakes. Glacial erosion surface water after the formation of depressions formed by glacial lakes, known as glacial lake; lake after glaciers retreat, mix the gravel on the ground piled high around the middle of the low lying land, or blockage formed part of the riverbed, said the ice Moraine Lake. Crater lake of lava and volcanic detritus accumulate around the crater that formed the crater lake depressions formed poly water. Its roughly circular or horseshoe shape, surface area and catchment area are not large, deep lake. Generally located in areas of volcanic activity in ancient and modern times. Lake due to earthquakes, landslides, landslides, mudslides, or volcanic eruption moraine lava and debris clogging the river and the formation of lakes. Wind into the lake due to the ground to form a long-term effect of wind and water erosion depressions formed lakes. Depressions between dunes water can also be formed into a lake wind. Such lakes are characterized by flat lake, lakeshore than the rule, small area, no exit shallow lake variation, high salinity, and many more seasonal lake (intermittent lakes) appear. Because hydraulic alluvial lake water erosion and siltation of lakes formed. According to the characteristics of different water effects such lakes can be divided into the following categories: ① the river into the lake. Due to river diversion, straightening, siltation forming a part of the original river basin. Such Lake area is small, keep the original river channel shape, deep concave bank steep, lake and river waters flood interlinked, also known as oxbow lakes, bow lake, Crescent Lake, and many more distributed along the river. ② floodplain lake. As the water in the floodplain water erosion after the formation of depressions formed lakes. ③ embankment breach lake. When severe erosion embankment burst water lakes formed. ④ □ lake. Shallow bay lake due to siltation mouth of the bay and ocean isolation is formed. Atoll reef development are formed around the part of the body of water is also such a case. Also known as the Sea traces lake, the sea into the lake, remnants Lake. Since lake water is dissolved in the dissolution of water to produce depressions formed by dissolution of the lake. Limestone and other soluble rocks distributed in a wider area, followed by the formation of surface water or groundwater dissolution karst lakes, groundwater, or because certain salts dissolved in soil subsidence caused by the collapse made lake, etc., are dissolved in the lake. Organic lake by the accumulation of organic matter, such as aquatic plants or corals formed lakes. Artificial lake is generally known as the reservoir (see Reservoir hydrological effects). From the genesis point of view, these lakes tectonic lake, crater lake within the Department battalion force formed; lake may be formed by a force within the camp may also be formed by a force outside the camp; rest of the lake is mainly composed of various types of Camp force formation. Most lakes are often outside the camps, including Camp forces and formed under the combined effect of the force. In addition, there are classified according to certain characteristics of individual lakes. Eg: In accordance with the relationship between the lake and runoff into the lake outflow lakes and inland lakes, or drainage lake (Lake throughput) and non-drainage lake (Non-throughput Lake); according to water heat conditions, will be divided into a tropical freshwater lake, Lake temperate and boreal lakes; nutrient content in accordance with the lake as nitrogen, phosphorus, water, biomass and green water pH, biological oxygen demand, water color and transparency composite indicator of water quality, the lake is divided into eutrophic lake, nutrition Type the lake and oligotrophic lake; according to salinity water can be divided into freshwater lakes (lake salinity generally refers to less than 1%), lagoons, salt (generally refers to water salinity more than 24.7 percent). Lake basin morphology in the development process and constantly changing their shape, morphology study lakes to help research the origin of the lake, the lake's volume calculation, study lake physicochemical properties and hydrological regime