甘肃省2004-2009年土地沙漠化时空变化分析

基于遥感和GIS技术,选取2004年和2009年的TM和ETM遥感数据,并辅以甘肃省地形图及其他资料,通过野外调查和人机交互解译,采用转移矩阵分析研究甘肃省沙漠化土地面积、程度、类型变化及区域分异,并对其变化因素进行了分析.结果表明,总体上甘肃省沙漠化土地面积在减少,沙漠化程度在减轻,土地沙漠化呈现逆转的态势,但玛曲县沙漠化土地面积有所增加.一方面是由于气候变化和降水减少,导致黄河河道来水量减少,河道滩地裸露,原来的水域变化为固定沙地；另一方面是由于过度放牧,使大面积的非沙漠化土地变为流动、固定、半固定沙地,导致沙漠化进一步加剧.

Spatial and Temporal Changes of Aeolian Desertification Land from 2004 to 2009 in Gansu Province,China

Supported by remote sensing data and geographic information system, based on land topographic maps and other materials, we extracted aeolian desertification land information of Gansu Province in 2004 and 2009 through field investigation and man-machine interactive interpretation of TM and ETM images, then we analyzed the area, degrees, types and spatial variation of the aeolian desertification land in Gansu Province using the transfer matrix method. Results showed the aeolian desertification land area decreased, the desertification degree reduced, and land desertification showed an obvious reversing trend as a whole, only in Maqu County the aeolian desertification land area increased. The reasons for aeolian desertification land area increase in the Maqu County are that previous water areas are converted into fixed sandy lands due to decreased river inflow and previous non-desertification lands into desertification lands due to over-grazing.