近50a来科尔沁地区沙漠化土地的动态监测结果与分析

在明确了沙漠化土地的程度分级及其指标、监测方法的基础上,对科尔沁地区近50 a来的沙漠化土地进行了遥感动态监测和分析。结果表明:科尔沁地区20世纪50年代未至70年代中期,是沙漠化土地扩展速度最快的一个时期,总面积增加了9 084 km²。从70年代中期到80年代后期,沙漠化土地继续呈快速增长之势,增加了9 624 km²;进入90年代,沙漠化过程呈现出逆转的趋势,沙漠化土地总面积由1987年的61 008 km²,减少到2000年的50 142 km²,减少了10 866 km²。就近50 a来沙漠化土地变化的整体而言,经历了发展-再发展-逆转的过程。到2000年,科尔沁地区的沙漠化态势依然是严峻的。但从整个发展过程来看,沙漠化已呈现逆转的趋势。整个区域的生态环境在改善,环境容量在提高,继续发展下去,有望进入良性循环以保障生态环境与社会经济的可持续发展。

Dynamic Monitor to Evolvement of Sandy Desertified Land in Horqin Region for the Last 5 Decades, China

The evolvement of sandy desertified land in Horqin region for the last 5 decades was dynamically monitored and analyzed based on the grading indexes of desertified lands and the effective monitoring method.In the 20th Century,the desertified land developed at the most fast speed from late 1950s to middle 1970s and the total area had increased by 9 084 km²;the development of desertified land lasted its fast-developing trend from middle 1970s to late 1980s and the total area had increased by 9 624 km²;as entering 1990s the processes of desertification became inversed,the total area had decreased from 61 008 km² in year 1987 to 50 142 km² in year 2000 and had decreased by 10 866 km² during the 13 years.In the past 50 years the desertified land has generally experienced the processes of developing → further developing → inversing.Although the status of desertified land development was still arduous by year 2000,the revising trend is hopeful.If the trend of eco-environment being improved and the environmental caring capacity being heightened is going on the eco-environment and the social economy are possibly entering the sustainable development.