1998—2009年洞里萨湖流域湿地时空变化特征研究

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

以洞里萨湖流域湿地为研究区,利用1988年、1991年、1995年、2005年、2007年、2009年6期Landsat TM影像数据,采用全局空间自相关和空间转移矩阵,对洞里萨湖流域湿地格局变化进行研究。结果表明:洞里萨湖流域湿度指数的全局Moran’s I值为0.789~0.831(P<0.01),呈显著的正空间自相关,但空间集聚程度呈现下降趋势,降速为每年0.52%。6个时期洞里萨湖流域湿度指数呈现下降趋势,降速为每年0.02%,其中2007年全区湿度指数最低。在空间上,湿度指数由内向外呈现“高—低—高”的分布特征,植被性湿地从1988年的18 580.21 km^2减少为2009年的18 435.24 km^2,非植被性湿地从1988年的3 739.64 km^2减少为2009年的3 510.50 km^2,洞里萨湖流域大面积的植被砍伐对1998—2009年湿地面积的减少有重要影响。该研究可为洞里萨湖流域湿地资源的可持续发展提供参考。

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 in2009. 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.