TONLE SAP

Khmer Bng Tnl Sab natural floodplain reservoir, central Cambodia. The lake is drained during the dry season by the Sab River (Tnl Sab) across the muddy Val Pc plain southeastward to the Mekong River. Called by the French Grand Lac (Great Lake), the lake is fed by numerous erratic tributaries and also by the Srng and Sn rivers, which are perennial northern tributaries. Many of the lake and river tributaries were dammed after 1975. During the June-to-November monsoonal regime, the swollen Mekong reverses the southeastward flow of the Sab River, which increases Tonle Sap's area from about 1,050 square miles (2,700 square km) to about 4,000 square miles (10,360 square km); its depth also increases from 310 feet (0.93 m) to 3045 feet (914 m), permitting vessels with 9 feet (3 m) of draft to navigate it up through the various tributaries, on which are situated the towns of Kmpng Thum (Kompong Thom), Siemrab, Batdmbng (Battambang), and Pouthisat (Pursat). During the rainy season the lake's width increases from about 22 miles (35 km) to 65 miles (105 km). At low water it is little more than a reed-infested swamp, with channels for fishing craft. The lake, the largest freshwater body in Southeast Asia, supports a large carp-breeding and carp-harvesting industry, with numerous floating fishing villages. The fermented and salted fish are staples of the Cambodian diet.