The Spatial-temporal Changes of Wetland in the Tonle Sap Lake Basin from 1988 to 2009

In this study, Tonle Sap Lake Basin was selected as the study area. Based on the Landsat TM image data in 6 years (1988, 1991, 1995, 2005, 2007, 2009), spatial-temporal variation characteristics of the wetland were studied by means of tasseled cap, spatial autocorrelation analysis and transition matrix. The results showed that the global Moran's I of the humidity index of the wetland was between 0.789−0.831 (P<0.01), showing a significant positive spatial autocorrelation, but the degree of spatial agglomeration showed a downward trend with a rate of 0.52% every year. In the six periods, the humidity index of the wetland showed a downward trend with a rate of 0.02% every year, and the humidity index in 2007 was the lowest. The humidity index showed the distribution pattern of 'high-low-high' from inside to outside. Vegetation wetlands decreased from 18 580.21 km² in 1988 to 18 435.24 km² in 2009, and non-vegetation wetlands decreased from 3 739.64 km² in 1988 to 3 510.50 km² in 2009. Large-scale deforestation in the Tonle Sap Lake Basin had an important impact on the reduction of wetland area in 1998−2009. This study can provide a certain reference value for the sustainable development of wetland resources in the Tonle Sap Lake Basin.