【摘要】 基于EOS-MODIS遥感数据,利用GIS计算出归一化植被指数(NDVI)和植被覆盖指数(PV),计算得到荒漠化指数(DI)对浑善达克沙地荒漠化进行识别,根据像元数统计不同荒漠化类型的面积及其变化数据,再分析荒漠化面积与气象要素的相关性,进而得出近13 a在气候波动下浑善达克沙地荒漠化的动态变化。结果表明:浑善达克沙地年平均气温呈下降趋势,年平均降水量呈增加趋势,且平均降水量对荒漠化动态变化的影响比平均气温对荒漠化动态变化的影响大。在气候波动影响下浑善达克沙地以荒漠化面积缩小为主,中度荒漠化,重度荒漠化和极重度荒漠化对荒漠化的演替贡献较大,表现为高程度荒漠化向低程度荒漠化转换。空间分布上,表现为西部极重度荒漠化面积明显减少,主要转化为重度荒漠化类型,东中部重度荒漠化明显减少,主要转化为未荒漠化和轻度荒漠化类型。更多还原

【Abstract】 In recent years,the desertification has been researched deeply,especially the Hunshandake Desert,which is one of the most serious desertification areas in China and also one of the important sources of dust from East Asia,threating local people’s life and economy. For the evolution of desertification is a complex process,it is necessary to study it in all aspects. This paper used GIS to calculate the normalized vegetation index(NDVI)and vegetative cover index(PV)based on EOS-MODIS remote sensing data. Then the desertification index(DI)was obtained to identify the desertification of Hunshandake Desert. The areas of different types of desertification were calculated based on pixel scale. Moreover,the correlation between desertification areas and meteorological elements was analyzed to obtain the dynamic change of desertification of Hunshandake Desert in recent13 years. The result indicated that annual mean temperature was decreasing and the mean precipitation was increasing in Hunshandake Desert. The influence of precipitation on dynamic changes of desertification was larger than that of temperature. The desertification area was decreasing in recent 13 years under the climate fluctuation.The changes of moderate,severe and extreme desertification were obvious which was represented by the conversion from extreme desertification to mild desertification. Spatially,the area of extreme desertification in the west of Hunshandake Desert was obviously decreasing which converted into severe desertification. However,the areas of severe desertification in the east and middle parts of Hunshandake Desert were decreasing which converted into normal and mild desertification. The current position of desertification seems to be better,it maybe the project of Conversion of Cropland to Forest or Grassland or it may result in the change climate. Thus,there are some uncertain situations that need us for a further study.更多还原