Tonlé Sap, truly vast stream; crisp, not salty, ordinarily meant "Awesome Lake") alludes to a regularly immersed freshwater lake, the Tonlé Sap Lake and an appended waterway, the 120 km (75 mi) long Tonlé Sap River, that associates the lake to the Mekong River. They shape the focal piece of a complex hydrological framework, arranged in the 12,876 km2 (4,971 sq mi) Cambodian floodplain secured with a mosaic of regular and agrarian living spaces that the Mekong renews with water and residue every year. The focal plain development is the consequence of a huge number of years of Mekong alluvial statement and release. From a geographical point of view, the Tonlé Sap Lake and Tonlé Sap River are an ebb and flow solidify outline portrayal of the gradually, however continually moving Lower Mekong Basin. Yearly variance of the Mekong's water volume, supplemented by the Asian Monsoon administration causes the extraordinary stream inversion of the Tonle Sap River.
The Tonlé Sap Lake possesses a land discouragement (the most minimal lying territory) of the immense alluvial and lacustrine floodplain in the Lower Mekong Basin, which had been actuated by the crash of the Indian Plate with the Eurasian Plate. The lake's size, length and water volume fluctuates extensively throughout a year from a region of around 2,500 km2 (965 sq mi), a volume of 1 km3 (0.24 cu mi) and a length of 160 km (99 mi) toward the finish of the dry season in late April to a range of up to 16,000 km2 (6,178 sq mi), a volume of 80 km3 (19 cu mi) and a length of 250 km (160 mi) as the Mekong most extreme and the pinnacle of the South-West storm's precipitation come full circle in September and early October.
As one of the world's most differed and beneficial biological systems the district has dependably been of focal significance for Cambodia's sustenance arrangement. It demonstrated prepared to do to a great extent keeping up the Angkorean human advancement, the biggest pre-mechanical settlement complex in world history. Either straightforwardly or in a roundabout way it influences the work of expansive quantities of an overwhelmingly country populace right up 'til today. Concerning a developing and relocating populace, ineffectual organization and far reaching impassion towards ecological issues the lake and its encompassing biological community is going under expanding weight from over-misuse and natural surroundings corruption, discontinuity and misfortune. All Mekong riparian states have either reported or effectively actualized arrangements to progressively abuse the stream's hydroelectric potential. A progression of global offices that dam the stream's standard is probably going to be the gravest threat yet for the whole Tonle Sap eco-locale.
The biggest freshwater lake in Southeast Asia, that contains an extraordinary expansive assortment of interconnected eco-locales with a high level of biodiversity is a biodiversity hotspot and was assigned as an UNESCO biosphere save in 1997.