Impact of the Mekong River Flow Alteration on the Tonle Sap Food Pulse



Impact of the Mekong River Flow Alteration on the Tonle Sap Food Pulse
Matti Kummu and Juha Sarkkula

Rapid development in the upper reaches of the Mekong River,  in  the  form  of  construction  of  large  hydropower dams and reservoirs, large irrigation schemes, and rapid urban  development,  is  putting  water  resources  under
stress. Recent studies have concluded that these developments will lead to flow alterations in the Mekong River. These  flow  alterations  would  threaten  the  sensitive ecosystems  downstream,  particularly  Tonle  Sap  River,
Tonle Sap Lake, its floodplain, and its gallery forest and protected areas, by changing the flood-pulse system of the lake. This article estimates the changes in parameters of the Tonle Sap flood pulse due to the aforementioned
flow alterations. The impacts on the flooded area and loss of gallery forest and protected areas were analyzed using geographic  information  system–based  methods.  Relatively small rises in the dry-season lake water level would
permanently  inundate  disproportionately  large  areas  of floodplain, rendering it inaccessible to floodplain vegetation and eroding the productivity basis of the ecosystem. It is highly important to maintain the natural hydrological pattern of the Mekong River, particularly the dry-season water levels,  to preserve Tonle Sap  Lake’s ecosystem productivity.



Royal Swedish Academy of Sciences 2008
Ambio Vol.37 No.3, May 2008, pp. 185-192