75-555: Powai Lake (Pronunciation: [pəʋəiː] ) is an artificial lake , situated in Mumbai , in the Powai valley, where a Powai village with a cluster of huts existed. The city suburb called Powai shares its name with the lake. Indian Institute of Technology Bombay , one of the premier institutions of science and technology in India, is located to the east of the lake. Another famous institution,
150-550: A tourist attraction . Before the lake was built by the British , in 1799 AD , the estate where the lake is now was leased on a yearly rent to Dr. Scott. After his death in 1816, the government took control of the estate in 1826 and leased it to Framaji Kavasji, then the vice-president of the Agricultural and Horticultural Society of Western India after whom the lake was named when it was built in 1891. A stream tributary of
225-409: A body of water from 2 hectares (5 acres) to 8 hectares (20 acres). Pioneering animal ecologist Charles Elton regarded lakes as waterbodies of 40 hectares (99 acres) or more. The term lake is also used to describe a feature such as Lake Eyre , which is a dry basin most of the time but may become filled under seasonal conditions of heavy rainfall. In common usage, many lakes bear names ending with
300-495: A catchment of 6.61 km (part of the Powai-Kanheri hill ranges which also drain into the adjoining Vihar Lake and Tulsi Lake ). The dam, built in stone masonry has a height varying from 3 m to 6m with top level of the dam kept at E.L. 58.5 m (with Town hall datum). Government of Maharashtra reports that due to eutrophication of the lake water from untreated sewage and garbage from nearby residential and slum colonies,
375-500: A comprehensive analysis of the origin of lakes and proposed what is a widely accepted classification of lakes according to their origin. This classification recognizes 11 major lake types that are divided into 76 subtypes. The 11 major lake types are: Tectonic lakes are lakes formed by the deformation and resulting lateral and vertical movements of the Earth's crust. These movements include faulting, tilting, folding, and warping. Some of
450-402: A form of organic lake. They form where a buildup of partly decomposed plant material in a wet environment leaves the vegetated surface below the water table for a sustained period of time. They are often low in nutrients and mildly acidic, with bottom waters low in dissolved oxygen. Artificial lakes or anthropogenic lakes are large waterbodies created by human activity . They can be formed by
525-538: A higher perimeter to area ratio than other lake types. These form where sediment from a tributary blocks the main river. These form where sediment from the main river blocks a tributary, usually in the form of a levee . Lakes formed by other processes responsible for floodplain basin creation. During high floods they are flushed with river water. There are four types: 1. Confluent floodplain lake, 2. Contrafluent-confluent floodplain lake, 3. Contrafluent floodplain lake, 4. Profundal floodplain lake. A solution lake
600-510: A hypolimnion; accordingly, very shallow lakes are excluded from this classification system. Based upon their thermal stratification, lakes are classified as either holomictic , with a uniform temperature and density from top to bottom at a given time of year, or meromictic , with layers of water of different temperature and density that do not intermix. The deepest layer of water in a meromictic lake does not contain any dissolved oxygen so there are no living aerobic organisms . Consequently,
675-428: A lake consists of a large area of standing water that occupies an extensive closed depression in limestone, it is also called a karst lake . Smaller solution lakes that consist of a body of standing water in a closed depression within a karst region are known as karst ponds. Limestone caves often contain pools of standing water, which are known as underground lakes . Classic examples of solution lakes are abundant in
750-470: A large number of studies agree that small ponds are much more abundant than large lakes. For example, one widely cited study estimated that Earth has 304 million lakes and ponds, and that 91% of these are 1 hectare (2.5 acres) or less in area. Despite the overwhelming abundance of ponds, almost all of Earth's lake water is found in fewer than 100 large lakes; this is because lake volume scales superlinearly with lake area. Extraterrestrial lakes exist on
825-528: A major shift from the hypertrophic condition to mesotrophic condition by adopting a novel technique of aeration and bioremediation . This has resulted in the lake being used for fishing and recreational purposes. The Lake's water depth is reported to have reduced to as little as 0.33 metres (1.1 ft) at some locations, on account of the large inflow of sewage, domestic waste water and silt from surrounding residential and industrial areas. Brihanmumbai Municipal Corporation (BMC) has therefore plans to desilt
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#1732787422095900-489: A natural outflow and lose water solely by evaporation or underground seepage, or both. These are termed endorheic lakes. Many lakes are artificial and are constructed for hydroelectric power generation, aesthetic purposes, recreational purposes, industrial use, agricultural use, or domestic water supply . The number of lakes on Earth is undetermined because most lakes and ponds are very small and do not appear on maps or satellite imagery . Despite this uncertainty,
975-403: A result of meandering. The slow-moving river forms a sinuous shape as the outer side of bends are eroded away more rapidly than the inner side. Eventually a horseshoe bend is formed and the river cuts through the narrow neck. This new passage then forms the main passage for the river and the ends of the bend become silted up, thus forming a bow-shaped lake. Their crescent shape gives oxbow lakes
1050-535: A result of the 1959 Hebgen Lake earthquake . Most landslide lakes disappear in the first few months after formation, but a landslide dam can burst suddenly at a later stage and threaten the population downstream when the lake water drains out. In 1911, an earthquake triggered a landslide that blocked a deep valley in the Pamir Mountains region of Tajikistan , forming the Sarez Lake . The Usoi Dam at
1125-422: A variation in density because of thermal gradients. Stratification can also result from a density variation caused by gradients in salinity. In this case, the hypolimnion and epilimnion are separated not by a thermocline but by a halocline , which is sometimes referred to as a chemocline . Lakes are informally classified and named according to the seasonal variation in their lake level and volume. Some of
1200-443: Is sag ponds . Volcanic lakes are lakes that occupy either local depressions, e.g. craters and maars , or larger basins, e.g. calderas , created by volcanism . Crater lakes are formed in volcanic craters and calderas, which fill up with precipitation more rapidly than they empty via either evaporation, groundwater discharge, or a combination of both. Sometimes the latter are called caldera lakes, although often no distinction
1275-459: Is 42.70 mg/litre on the surface and 119 mg/litre at the bottom of the lake. Appreciating the problem of silting, growth of water hyacinth, weed, and eutrophication of the lake, the IIT Bombay's Class of 1980 launched a "Revitalization of Powai Lake" with the objective of restoring the lake to its original pristine and sustainable form by adopting Eco-friendly designs and materials for
1350-524: Is 7 km . The dam height was raised in 1872 resulting in increase of water supply from 32 million gallons (catering to a population of 0.7 million) to 36 million gallons. The lake and its catchment are protected by the Brihanmumbai Municipal Corporation and Sanjay Gandhi National Park Authority. The catchment areas of Vihar lake has high hills rising on all sides. The seclusion, protection, and security provided under
1425-403: Is a lake occupying a basin formed by surface dissolution of bedrock. In areas underlain by soluble bedrock, its solution by precipitation and percolating water commonly produce cavities. These cavities frequently collapse to form sinkholes that form part of the local karst topography . Where groundwater lies near the grounds surface, a sinkhole will be filled water as a solution lake. If such
1500-468: Is dammed behind an ice shelf that is attached to the coastline. They are mostly found in Antarctica. Fluvial (or riverine) lakes are lakes produced by running water. These lakes include plunge pool lakes , fluviatile dams and meander lakes. The most common type of fluvial lake is a crescent-shaped lake called an oxbow lake due to the distinctive curved shape. They can form in river valleys as
1575-452: Is made. An example is Crater Lake in Oregon , in the caldera of Mount Mazama . The caldera was created in a massive volcanic eruption that led to the subsidence of Mount Mazama around 4860 BCE. Other volcanic lakes are created when either rivers or streams are dammed by lava flows or volcanic lahars . The basin which is now Malheur Lake , Oregon was created when a lava flow dammed
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#17327874220951650-568: Is now involved with The lake is about 40 kilometres (25 mi) from Mumbai 's downtown by road and is approached via Kurla or through Santa Cruz and Andheri . Kanjurmarg on the Central Line (Mumbai Suburban Railway) of the Mumbai Suburban Railway is the nearest railway station to the lake. The airport is also nearby. It is reported that the average rainfall at Powai is about 2,540 millimetres (100 in), and
1725-429: Is unknown but is estimated to be at least 2 million. Finland has 168,000 lakes of 500 square metres (5,400 sq ft) in area, or larger, of which 57,000 are large (10,000 square metres (110,000 sq ft) or larger). Most lakes have at least one natural outflow in the form of a river or stream , which maintain a lake's average level by allowing the drainage of excess water. Some lakes do not have
1800-759: The Malheur River . Among all lake types, volcanic crater lakes most closely approximate a circular shape. Glacial lakes are lakes created by the direct action of glaciers and continental ice sheets. A wide variety of glacial processes create enclosed basins. As a result, there are a wide variety of different types of glacial lakes and it is often difficult to define clear-cut distinctions between different types of glacial lakes and lakes influenced by other activities. The general types of glacial lakes that have been recognized are lakes in direct contact with ice, glacially carved rock basins and depressions, morainic and outwash lakes, and glacial drift basins. Glacial lakes are
1875-630: The Mithi river , which served the Powai village's water needs, was dammed in 1891, during the British period. It was initially to augment water supply to Bombay city (now called Mumbai), by constructing two dams of 10 m to store the rain water flowing from the lower slopes of the Western Ghats and streams from the eastern and northeastern slopes of hills. It was planned as an antiwater famine measure, to
1950-708: The National Institute of Industrial Engineering (NITIE), is also located close to the lake. Housing complexes and plush hotels are developed all around the lake periphery. Population around the lake has thus substantially increased over the years. When it was built, the lake had an area of about 2.1 square kilometres (520 acres) and the depth varied from about 3 metres (9.8 ft) (at the periphery) to 12 metres (39 ft) at its deepest. The Powai Lake has gone through many stages of water quality degradation. The lake water which used to supply drinking water for Mumbai has been declared unfit to drink. The lake remains
2025-554: The Proto-Indo-European root * leǵ- ('to leak, drain'). Cognates include Dutch laak ('lake, pond, ditch'), Middle Low German lāke ('water pooled in a riverbed, puddle') as in: de:Wolfslake , de:Butterlake , German Lache ('pool, puddle'), and Icelandic lækur ('slow flowing stream'). Also related are the English words leak and leach . There is considerable uncertainty about defining
2100-579: The Tulsi Lake and the Powai Lake (shown in map). It partly meets the drinking water needs of the Mumbai region. It supplies only 3% of the Mumbai city's water requirement, after filtration at Bhandup where the large water filtration plant is located. With the few thousand wells feeding the population of Mumbai tending to go dry during summer, the acute shortage of water resulted in protests by
2175-399: The density of water varies with temperature, with a maximum at +4 degrees Celsius, thermal stratification is an important physical characteristic of a lake that controls the fauna and flora , sedimentation, chemistry, and other aspects of individual lakes. First, the colder, denser water typically forms a layer near the bottom, which is called the hypolimnion . Second, normally overlying
2250-481: The water cycle , the processes by which water moves around the Earth. Most lakes are freshwater and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater . Lakes vary significantly in surface area and volume of water. Lakes are typically larger and deeper than ponds , which are also water-filled basins on land, although there are no official definitions or scientific criteria distinguishing
2325-615: The Bombay Blasts on 12 March 1993 due to perceived threats to the Mumbai public, as the lake is located in the Sanjay Gandhi National Park . It can still be viewed in many Bollywood movies in a long shot taken from Mumbai Film City, as seen in the Infobox. Impoundment of Mithi River, 20 km (12 mi) north of Mumbai, was effected to store the rainwater from a catchment area of 18.96 km to create
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2400-798: The Bombay Presidency Angling Association was formed in 1936. In 1955, under the Societies Registration Act 1860, it was registered as the Maharashtra State Angling Association (MSAA) and the lake is now under their control. Realising the gravity of the environmental pollution, the MSAA has revised its constitution "to actively care for, clean, develop, maintain, and beautify the Environment at Powai Lake." MSAA
2475-545: The Earth by extraterrestrial objects (either meteorites or asteroids ). Examples of meteorite lakes are Lonar Lake in India, Lake El'gygytgyn in northeast Siberia, and the Pingualuit crater lake in Quebec, Canada. As in the cases of El'gygytgyn and Pingualuit, meteorite lakes can contain unique and scientifically valuable sedimentary deposits associated with long records of paleoclimatic changes. In addition to
2550-571: The Lusatian Lake District, Germany. In India, Sudarshana Lake is a historical artificial lake located in the semi-arid region of Girnar, Gujarat, originally constructed during the reign of Chandragupta Maurya. See: List of notable artificial lakes in the United States Meteorite lakes, also known as crater lakes (not to be confused with volcanic crater lakes ), are created by catastrophic impacts with
2625-936: The Powai Lake at a cost of US$ 9 million. Many crocodiles have been seen on the lake side. White-throated kingfisher , small blue kingfisher , Indian spot-billed duck , spotted dove , a few purple swamphens , purple-rumped sunbirds , bronze-winged and pheasant-tailed jacanas , ashy prinias , brahminy kite , red-vented , red-whiskered and white-browed bulbuls , cormorants , lesser whistling ducks , grey , purple and Indian pond herons , little , intermediate egret and great egrets , peregrine falcon , greater coucal , rose-ringed and Alexandrine parakeets , Eurasian marsh harrier (possibly winter visitor), woolly-necked stork (winter visitor) hoopoe and whiskered terns . butterflies , honey bees , bumble bees and beetles have also been sighted. Balsam bushes, in their full bloom, in pink-purple color are seen around
2700-590: The Powai Lake. Vihar reservoir was the first piped water supply scheme of Mumbai. In 1850, Captain Crawford submitted a report favouring the Vihar Scheme for the Mumbai city's water supply needs. Work on the "Vihar Water Works" commenced in January 1856 and was completed in 1860, during the governorship of John Lord Elphinstone . The Brihanmumbai Municipal Corporation (BMC), a Govt. body which controls
2775-515: The Sanjay Gandhi National Park has ensured well wooded hill slopes and abundant natural regeneration. Higher percentage of khair species has been noted in the catchment area of the lake. As the lake is situated inside the Sanjay Gandhi National Park, the flora and fauna reported for the park would be relevant to the lake. However, fresh water crocodiles Mugger or Marsh crocodiles ( Crocodilus palustris ) are known to inhabit
2850-463: The Vihar Lake. The Powai-Kanheri hill ranges form the catchment area, which drains the rain water into the lake. For this purpose, three earthen embankment dams with a masonry spillway section were constructed to create a reservoir of 9200 million gallons capacity at the full reservoir level of 80.42 metres. The lake has a maximum water depth of 34 m and a minimum of 12 m. The lakes water spread area
2925-866: The base of the valley has remained in place for more than 100 years but the terrain below the lake is in danger of a catastrophic flood if the dam were to fail during a future earthquake. Tal-y-llyn Lake in north Wales is a landslide lake dating back to the last glaciation in Wales some 20000 years ago. Aeolian lakes are produced by wind action . These lakes are found mainly in arid environments, although some aeolian lakes are relict landforms indicative of arid paleoclimates . Aeolian lakes consist of lake basins dammed by wind-blown sand; interdunal lakes that lie between well-oriented sand dunes ; and deflation basins formed by wind action under previously arid paleoenvironments. Moses Lake in Washington , United States,
3000-621: The condition of Powai Lake and included the Lake in its list of ten major lakes in the country for revival and improvements. The restoration/revival programme, fully funded by the NLCP, was launched in April 2002, and implemented by Bombay Municipal Corporation (BMC) now called Brihanmumbai Municipal Corporation (BMC), the Government of Maharashtra and as a result the status of the lake has undergone
3075-915: The courses of mature rivers, where a river channel has widened over a basin formed by eroded floodplains and wetlands . Some lakes are found in caverns underground . Some parts of the world have many lakes formed by the chaotic drainage patterns left over from the last ice age . All lakes are temporary over long periods of time , as they will slowly fill in with sediments or spill out of the basin containing them. Artificially controlled lakes are known as reservoirs , and are usually constructed for industrial or agricultural use, for hydroelectric power generation, for supplying domestic drinking water , for ecological or recreational purposes, or for other human activities. The word lake comes from Middle English lake ('lake, pond, waterway'), from Old English lacu ('pond, pool, stream'), from Proto-Germanic * lakō ('pond, ditch, slow moving stream'), from
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3150-518: The creation of lakes by the disruption of preexisting drainage networks, it also creates within arid regions endorheic basins that contain salt lakes (also called saline lakes). They form where there is no natural outlet, a high evaporation rate and the drainage surface of the water table has a higher-than-normal salt content. Examples of these salt lakes include Great Salt Lake and the Dead Sea . Another type of tectonic lake caused by faulting
3225-622: The difference between lakes and ponds , and neither term has an internationally accepted definition across scientific disciplines or political boundaries. For example, limnologists have defined lakes as water bodies that are simply a larger version of a pond, which can have wave action on the shoreline or where wind-induced turbulence plays a major role in mixing the water column. None of these definitions completely excludes ponds and all are difficult to measure. For this reason, simple size-based definitions are increasingly used to separate ponds and lakes. Definitions for lake range in minimum sizes for
3300-536: The exception of criterion 3, the others have been accepted or elaborated upon by other hydrology publications. The majority of lakes on Earth are freshwater , and most lie in the Northern Hemisphere at higher latitudes . Canada , with a deranged drainage system , has an estimated 31,752 lakes larger than 3 square kilometres (1.2 sq mi) in surface area. The total number of lakes in Canada
3375-422: The hypolimnion is a transition zone known as the metalimnion . Finally, overlying the metalimnion is a surface layer of warmer water with a lower density, called the epilimnion . This typical stratification sequence can vary widely, depending on the specific lake or the time of year, or a combination of both. The classification of lakes by thermal stratification presupposes lakes with sufficient depth to form
3450-907: The intentional damming of rivers and streams, rerouting of water to inundate a previously dry basin , or the deliberate filling of abandoned excavation pits by either precipitation runoff , ground water , or a combination of both. Artificial lakes may be used as storage reservoirs that provide drinking water for nearby settlements , to generate hydroelectricity , for flood management , for supplying agriculture or aquaculture , or to provide an aquatic sanctuary for parks and nature reserves . The Upper Silesian region of southern Poland contains an anthropogenic lake district consisting of more than 4,000 water bodies created by human activity. The diverse origins of these lakes include: reservoirs retained by dams, flooded mines, water bodies formed in subsidence basins and hollows, levee ponds, and residual water bodies following river regulation. Same for
3525-471: The karst regions at the Dalmatian coast of Croatia and within large parts of Florida . A landslide lake is created by the blockage of a river valley by either mudflows , rockslides , or screes . Such lakes are most common in mountainous regions. Although landslide lakes may be large and quite deep, they are typically short-lived. An example of a landslide lake is Quake Lake , which formed as
3600-548: The lake in sustainable numbers. As it is difficult to sight them in the lake, the park has set up a Crocodile Park’ to view the reptiles of different sizes. Limnological studies carried out by the Central Public Health Engineering Research Institute, Nagpur, India, in 1964, indicated an unstable thermal stratification in the lake waters. The dissolved oxygen (DO) values were found to increase in some months and carbon dioxide
3675-654: The lake level. Vihar Lake Vihar Lake (Pronunciation: [ʋiɦaːɾ] ) is located near Vihar village on the Mithi River within the precincts of the Borivali National Park , also called the Sanjay Gandhi National Park , in North Mumbai . When built in 1860 (construction started in 1856), it was considered as the largest lake in Mumbai in the Salsette group of islands. It is hemmed between
3750-517: The lake overflows for about sixty days each year. The overflow from the lake flows into the Mithi River . Silt studies conducted in 1995 estimates in that 4500 lakh cubic metres of silt has been deposited in the lake since its construction. It supplied two million gallons of water to Bombay (now Mumbai) when it was built. Following the construction of the Tansa dam and creation of the reservoir, in 1892, Powai waters were used for irrigation. The lake drains
3825-424: The lake periphery, like a carpet. Lake A lake is an often naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land . Lakes lie completely on land and are separate from the ocean , although they may be connected with the ocean by rivers . Lakes, as with other bodies of water , are part of
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#17327874220953900-399: The lake water is unfit for drinking water use. Hence, the lake is now used for recreation, gardening, cattle washing and fishing. The water of the lake is also supplied to Aarey colony and Larsen & Toubro for non domestic uses. Dissolved Oxygen (DO) level at the bottom of the lake is reported to be 0.71 mg/litre and at surface 4.11 mg/litre, average value of pH is 7.2 and COD
3975-451: The lake's affairs has also acquired agricultural land in the catchment area of the Vihar lake as a sanitary precaution. By road, it is 31 km (19 mi) from Mumbai. Access by suburban electric train is to Kurla or Andheri and then by road. Access to the lake for the general public has been curtailed since 13 March 1993 (Source: Official BMC Board installed at the gate) following
4050-657: The largest lakes on Earth are rift lakes occupying rift valleys, e.g. Central African Rift lakes and Lake Baikal . Other well-known tectonic lakes, Caspian Sea , the Sea of Aral , and other lakes from the Pontocaspian occupy basins that have been separated from the sea by the tectonic uplift of the sea floor above the ocean level. Often, the tectonic action of crustal extension has created an alternating series of parallel grabens and horsts that form elongate basins alternating with mountain ranges. Not only does this promote
4125-528: The layers of sediment at the bottom of a meromictic lake remain relatively undisturbed, which allows for the development of lacustrine deposits . In a holomictic lake, the uniformity of temperature and density allows the lake waters to completely mix. Based upon thermal stratification and frequency of turnover, holomictic lakes are divided into amictic lakes , cold monomictic lakes , dimictic lakes , warm monomictic lakes, polymictic lakes , and oligomictic lakes. Lake stratification does not always result from
4200-560: The level of a lake are controlled by the difference between the input and output compared to the total volume of the lake. Significant input sources are precipitation onto the lake, runoff carried by streams and channels from the lake's catchment area, groundwater channels and aquifers, and artificial sources from outside the catchment area. Output sources are evaporation from the lake, surface and groundwater flows, and any extraction of lake water by humans. As climate conditions and human water requirements vary, these will create fluctuations in
4275-587: The local residents in June 1845. A two-man committee, appointed by the British rulers of the time, to examine the grievances of the agitators concurred with water shortage problem and stressed the urgent need to solve the water supply problem of Mumbai. The Committee appointed by the government located suitable sites to construct dams and create reservoirs to store the monsoon flows of the Mithi river catchment, which resulted in presently existing Vihar Lake, Tulsi Lake, and
4350-481: The mainland; lakes cut off from larger lakes by a bar; or lakes divided by the meeting of two spits. Organic lakes are lakes created by the actions of plants and animals. On the whole they are relatively rare in occurrence and quite small in size. In addition, they typically have ephemeral features relative to the other types of lakes. The basins in which organic lakes occur are associated with beaver dams, coral lakes, or dams formed by vegetation. Peat lakes are
4425-424: The mode of origin, lakes have been named and classified according to various other important factors such as thermal stratification , oxygen saturation, seasonal variations in lake volume and water level, salinity of the water mass, relative seasonal permanence, degree of outflow, and so on. The names used by the lay public and in the scientific community for different types of lakes are often informally derived from
4500-485: The moon Titan , which orbits the planet Saturn . The shape of lakes on Titan is very similar to those on Earth. Lakes were formerly present on the surface of Mars, but are now dry lake beds . In 1957, G. Evelyn Hutchinson published a monograph titled A Treatise on Limnology , which is regarded as a landmark discussion and classification of all major lake types, their origin, morphometric characteristics, and distribution. Hutchinson presented in his publication
4575-415: The morphology of the lakes' physical characteristics or other factors. Also, different cultures and regions of the world have their own popular nomenclature. One important method of lake classification is on the basis of thermal stratification, which has a major influence on the animal and plant life inhabiting a lake, and the fate and distribution of dissolved and suspended material in the lake. For example,
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#17327874220954650-406: The most numerous lakes in the world. Most lakes in northern Europe and North America have been either influenced or created by the latest, but not last, glaciation, to have covered the region. Glacial lakes include proglacial lakes , subglacial lakes , finger lakes , and epishelf lakes. Epishelf lakes are highly stratified lakes in which a layer of freshwater, derived from ice and snow melt,
4725-791: The names include: Lakes may be informally classified and named according to the general chemistry of their water mass. Using this classification method, the lake types include: A paleolake (also palaeolake ) is a lake that existed in the past when hydrological conditions were different. Quaternary paleolakes can often be identified on the basis of relict lacustrine landforms, such as relict lake plains and coastal landforms that form recognizable relict shorelines called paleoshorelines . Paleolakes can also be recognized by characteristic sedimentary deposits that accumulated in them and any fossils that might be contained in these sediments. The paleoshorelines and sedimentary deposits of paleolakes provide evidence for prehistoric hydrological changes during
4800-562: The organic-rich deposits of pre-Quaternary paleolakes are important either for the thick deposits of oil shale and shale gas contained in them, or as source rocks of petroleum and natural gas . Although of significantly less economic importance, strata deposited along the shore of paleolakes sometimes contain coal seams . Lakes have numerous features in addition to lake type, such as drainage basin (also known as catchment area), inflow and outflow, nutrient content, dissolved oxygen , pollutants , pH , and sedimentation . Changes in
4875-600: The restoration works. Some of the tasks proposed to be undertaken with the funds donated by IIT, Bombay included: The project was proposed to be professionally managed with a project manager working under directives of IIT Bombay with an "Oversight Committee" to monitor objectives set for the restoration work. In 1995, the National Lake Conservation Plan (NLCP) of the Ministry of Environment and Forests (MoE&F), Government of India, reviewed
4950-433: The southeast of Vihar Lake (a much larger lake) also for water supply to Mumbai city. The scheme was taken in hand in 1889. Though it was completed within a year at an initial cost of more than Rs. 6,50,000 and started providing two million gallons of water per day, it had to be abandoned due to the hue and cry against the quality of the water. Five lakhs of rupees more were spent on the scheme in 1919 in an attempt to restore
5025-597: The supply at least for the suburbs but this, too, was given up with the development of the Tansa works. After the drinking water supply objective was abandoned in the early 1890s, in view of poor quality of the water due to pollution, water hyacinth and weeds , untreated sewage and large silt deposit, the lake was leased to the Western India Fishing Association, a quasi government organisation , who used it for fish culture and angling . Later,
5100-404: The thermal stratification, as well as the degree and frequency of mixing, has a strong control over the distribution of oxygen within the lake. Professor F.-A. Forel , also referred to as the "Father of limnology", was the first scientist to classify lakes according to their thermal stratification. His system of classification was later modified and improved upon by Hutchinson and Löffler. As
5175-456: The times that they existed. There are two types of paleolake: Paleolakes are of scientific and economic importance. For example, Quaternary paleolakes in semidesert basins are important for two reasons: they played an extremely significant, if transient, role in shaping the floors and piedmonts of many basins; and their sediments contain enormous quantities of geologic and paleontologic information concerning past environments. In addition,
5250-641: The two. Lakes are also distinct from lagoons , which are generally shallow tidal pools dammed by sandbars or other material at coastal regions of oceans or large lakes. Most lakes are fed by springs , and both fed and drained by creeks and rivers , but some lakes are endorheic without any outflow, while volcanic lakes are filled directly by precipitation runoffs and do not have any inflow streams. Natural lakes are generally found in mountainous areas (i.e. alpine lakes ), dormant volcanic craters , rift zones and areas with ongoing glaciation . Other lakes are found in depressed landforms or along
5325-467: The word pond , and a lesser number of names ending with lake are, in quasi-technical fact, ponds. One textbook illustrates this point with the following: "In Newfoundland, for example, almost every lake is called a pond, whereas in Wisconsin, almost every pond is called a lake." One hydrology book proposes to define the term "lake" as a body of water with the following five characteristics: With
5400-545: The year 2006, finding sweet water at the Mahim Creek (a semi enclosed area), where fresh water and sea water meet, created a lot of excitement among the public. The health department of BMC who analysed the water sample from the site found that salt level in the sea water was as low as 600 particle per million (ppm), compared to the normal level 10000000 particle per million (ppm). The National Institute of Oceanography , Goa who were also consulted stated that this phenomenon
5475-412: Was found to be less at the surface than at the bottom. In cooler season, the surface water was found to be less alkaline, which could be attributed to the photosynthesis activity of the algae. The pH stratification was found to be unstable. Interrelation was attributed to fluctuations in the chlorophyll, pH and DO values and nitrates were generally absent on the surface and no sulphates were detected. In
5550-490: Was not unusual and could have been caused by heavy rainfall and low tide. This necessitated the Maharashtra Government to intervene and examine the issue rationally to convince the excited public. BMC Commissioner gave a press statement stating: The Mahim creek is located in a semi-enclosed area where fresh water and sea water mix especially during low tide, which caused the dilution. Also, the Vihar Lake on
5625-617: Was originally a shallow natural lake and an example of a lake basin dammed by wind-blown sand. China's Badain Jaran Desert is a unique landscape of megadunes and elongated interdunal aeolian lakes, particularly concentrated in the southeastern margin of the desert. Shoreline lakes are generally lakes created by blockage of estuaries or by the uneven accretion of beach ridges by longshore and other currents. They include maritime coastal lakes, ordinarily in drowned estuaries; lakes enclosed by two tombolos or spits connecting an island to
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