宁夏沙地遥感宏观动态研究

Macro-scale Survey and Dynamic Studies of Sandy Land in Ningxia by Remote Sensing

以宁夏1996年和2000年的TM影像为信息源,在全数字方式下运用遥感技术与地理信息系统技术结合建立了两期宁夏沙地数据库。通过分析得出:2000年宁夏有沙地面积313498hm2,与1996年相比新增加4894hm2、减少29705hm2、净减少24811hm2,净减少了7 333%。沙地占全区总土地面积的比例由1996年的6 533%减少到2000年的6 054%,平均每年净减少0 120%。同时,分析了全区沙地变化的驱动因子。沙地增加的主要因素是草地沙漠化和耕地沙化,两者分别占沙地总增加量的78 463%和13 302%;沙地减少的相互主要因素是沙地开垦为耕地和沙地恢复草被变为草地,两者分别占沙地总减少量的50 025%和46 666%。

By using digital method of remote sensing and geographical information system techniques, TM images of 1996 and 2000 have been interpreted to establish the database of sandy land of the two periods in Ningxia Region. In the study, the definition of the sandy land is the land that is covered by sand and the vegetation coverage is lower than 5%, and it includes sand desert. There are as much as \{313 498\} hm2 sandy lands in Ningxia Region in 2000 and \{24 811\} hm2 less than that in 1996, the sandy land deceased by 7\^334%. The percentage of sandy land area to the whole area decreased from 6\^533% in 1996 to 6\^054% in 2000, and decreased 0\^120% each year. Further, the factors causing sandy land change were analyzed. The factors causing sandy land increasing are grassland desertification and cultivated land desertification, and they occupied 78\^463% and 13\^302%, respectively. The factors causing sandy land decreasing are that sandy lands were cultivated and planted grass, and they occupied 50\^025% and 46\^666% in order.