What physical feature serves as a "safety-valve" overflow basin for flooding?

Answer and Explanation:

The Tonle Sap lake serves as a "safety-valve" overflow basin for flooding. It is located in Camboya. Its extension varies according to the season. The lake might occupy 2500 km² during the dry season but can reach up to 16000 km² during the wet season.

The Tonle Sap lake is fed by numerous rivers from different latitudes and altitudes, and it is tributary of the Sap river that flows towards the southeast and joins the Mekong river, conforming together the Basac river.

The Tonle Sap river is reversible, also according to the season.  When the Monzon rains enhance the Mekong river´s level, the curse of water of the Tonle Sap river inverts flowing towards back the northeast. The Tonle Sap river stops providing water to the Mekong and begins to provide water to the Tonle Sap Lake. This last one sharply elevates its level.

Once the wet season is over, the Tonle Sap river redirects its water back to its original direction.

The Tonle Sap lake acts as a regulator of the Mekong Lake´s course.

This lake is very rich in resources, especially fishes that live in these waters, and are the feeding source of most Vietnamese.

covalent bonding is a form of chemical bonding between two non metallic atoms which is characterized by the sharing of pairs of electrons between atoms and other covalent bonds.

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