中文摘要：

本文利用Landsat-TM和MODIS遥感影像,结合遥感、GIS空间分析及数理统计等技术方法,研究了1989～2010年海南岛西部沙化土地时空变化过程及其与气候因子的关系.结果表明：1）1989～2010年海南岛西部非沙化面积显著上升,总体增速为9.2km2/a,不同程度沙化区域面积均显著下降,轻度沙化区面积变化在沙化控制中起主导作用,重度沙化区面积下降最为显著;2）1990～2010年土地转移分析表明,20年中研究区域沙化土地面积总体降低174.04km2,其中67.67％的区域为轻度沙化土地,非沙化区域、轻度沙化区域、中度沙化区域以及重度沙化区域发生转化的面积分别达到1.59％、94.67％、98.02％和99.46％,沙化土地转换频繁,非沙化区域相对稳定;3）沙化土地主要分布在海岸带区域,植被覆盖度低,人类活动频繁,变化波动剧烈.2000年以来植被覆盖总体上升,其中西海岸的中部和北部植被覆盖显著上升,沙化土地得到明显改善;4）相关性分析表明：非沙化面积与年降水、年均温均呈显著正相关,相关系数分别为0.82（p＜0.01）和0.73（p＜0.05）,气温和降水是海南岛西部土地沙化的重要驱动因子,其中降水对土地沙化的影响相对较大.

英文摘要：

Land desertification is one of the most serious ecological problems in the world. Detection and attribution of land desertification has become a research focus in recent years. The social and economic status is influenced by desertification more significantly in the developed coastal areas. Hainan Island is a typical coastal region with severe desertification in China. With the impact of topography, western Hainan Island is tropical semi-arid region with the average annual temperature （24.92℃） and annual precipitation （987.56mm） in 60 years. The distribution of precipitation in a year is non-uniformity, mainly distributed in second half of the year. Annual evaporation of the region is far larger than the annual rainfall. Therefore, the incoordination of water and heat condition causes severe land desertification in west coastal region of Hainan Island. In this study, we collect Landsat-TM imageug （9 periods）, MODIS data （322 periods） and meteorological data of western Hainan Island, and extract land desertification information of study area based on difference of spectral characteristics. Then we use multiple methods and RS/GIS techniques, to analyze the spatial-temporal patterns of land desertification and their relationship to climate variations in western Hainan Island during 1989 ～ 2010. The main conclusions are as follows： （1） The non-desertification area has been sharply increasing at a rate of 9.2km2/a during 1989～2010. The decreasing of mild desertification area played an important role in the desertification control with 193.57km2 （64.2%） decreased, and the severe desertification area showed the most abrupt decline （24.26km2, 91.0% ）. （2） Based on a transition matrix of desertification land in western Hainan Island, the desertification area decreased by 174.04km2 consisting mainly of moderate desertification area （67.67%）. During the 20 years＇ period, the desertification land types that had changed were non-desertification land （1.59%）, mild desertificati