中国北方农牧交错带耕地动态变化的遥感监测

Dynamic change monitoring of cultivated land in a typical farming-pastoral ecotone in Northern China by remote sensing

以中国北方农牧交错带典型地区（科尔沁左翼后旗）的耕地资源作为研究对象,在RS和GIS的支持下,利用遥感影像（MSS,TM）重建了科尔沁左翼后旗1975、1985、1995、2000和2005年耕地的土地利用/覆盖变化信息.研究结果表明：1975～2005年间耕地面积整体上增加但增加的幅度略有不同;1995～2000年间耕地的土地利用动态度最大,而2000～2005年间耕地的土地利用动态度相对较小;1975～2000年间耕地整体重心向西迁移,2000年后耕地的重心缓慢向东迁移;1975～2005年间耕地面积的增加主要来自对草地的开垦和沼泽的围垦,耕地面积的减少主要由于耕地撂荒转变为草地（2000年前）、退耕转变为草地（2000年以后）和耕地的沙化、盐碱化等退化的发生;人口的不断增加和宏观政策的导向是影响科尔沁左翼后旗耕地动态变化的主要原因.

Taking the cultivated land of Keerqinzuoyihouqi in the interlock area of farming-pasturing typical region in Northern China as the research object, using TM, MSS, the information of land use/cover change （LUCC） in 1975, 1985, 1995, 2000 and 2005 was reconstructed, based on RS and GIS technique. The results show that cultivated land area increases yearly in different degrees from 1975 to 2005. From 1975 to 2000, cultivated land use dynamic degree is the biggest, from 1975 to 2000, it is relatively smaller. From 1975 to 2000, cultivated land center moves to west, but beginning to move to east slowly after 2000. From 1975 to 2000, the increase of cultivated land area is mainly from grass and swamp. The decrease of cultivated land area is mainly from cultivated land abandoned（before 2000）, mandatory conversion of marginal cultivated land to forestland and grassland （after 2000）, desertification and salinization. Population increase and macroscopic policy are the major forces for cultivated land change of the studied area.