人类活动影响下科尔沁沙地沙漠化动态的敏感性分析及灰色预测

利用90年代1◊25万和1◊50万的TM遥感影像及GIS获得的数据,结合该区70、80年代遥感调查数据,分析了科尔沁地区6个县的土地覆盖类型和潜在沙漠化动态及敏感因子。结果表明,1980～1990年该区的沙化面积从53%扩大到70%,林地下降10.7%,草地增加8.38%,主要为低覆盖草地。由于10年来人口密度增加了10人·km^-2,耕地平均增加了7%,人口增加和活动是土地覆盖变化的敏感性因子。分析该区沙漠化的自然因素表明气候变化导致沙漠化的正逆过程,人类活动是近代该区沙漠化加剧的直接原因。灰色预测表明该地区2000年以后人口增加,而沙漠化呈增加和减少两种趋势.

Sensitivity analysis and grey forecast on the dynamics of desertification of Kerqin sandy land under humain activities

Using remote sensing pictures acquired by Landsat TM1◊250000 and 1◊500000 in 1990s and GISdata,combining with the results of remote sensing investigation from 1970s to 1980s, the types of land cover,potential dynamics of desertification and sensitive factors in six counties of Kerqin sandy land were analyzed.From 1980s to 1990s.the desertification area in the region increased from 53% to 70%,forested land decreased by 10.7%,and grassland area increased by 8.38%,with a major increase of lowly covered land.Due to the increase of human population density by 10 persons·km^-2 in recent ten years,the cultivated land was increased by 7% on average.Population increase and human activities were the sensitive factors affecting the change of land cover.The analysis of natural factors influencing desertification shows that climate change might result in the processing of desertification,and human activity is the direct cause aggravating the desertification of Kerqin sandy land at modern time.The grey forecast shows that the human population would increase,and the desertification tended to increase or decrease after the year of 2000.