A landscape approach to assess impacts of hydrological changes to vegetation communities of the Tonle Sap Floodplain

Abstract

The Tonle Sap is South East Asia’s largest lake and Cambodia’s most important fishery. The hydrology of the Tonle Sap is directly linked to water levels of the Mekong River, which will experience major alterations as a response to hydropower development, irrigation, and climate change. This paper proposes a landscape approach to understand the impacts of hydrological alteration on the floodplain’s terrestrial vegetation. A land cover map, a digital elevation map and historical water records were used to create histograms of water depth for key vegetation communities. These histograms were used to create maps of vegetation coverage probability for future scenarios of hydrological changes. Selected scenarios of water resources development and climate change were used to demonstrate how vegetation could shift within the floodplain. This approach generated satisfactory results for land cover classes that extend over large portions of the floodplain such as wet season rice, abandoned fields, flooded shrubland and open lake.