土地沙漠化动态监测的遥感与GIS一体化探讨——以龙羊峡库区为例

DYNAMIC MONITORING OF LAND DESERTIFICATION BY RS AND GIS —A Case Study in Longyangxia Reservoir Area

以龙羊峡库区为试验区 ,实现遥感与GIS一体化 ,建立了龙羊峡库区地理信息系统 ,在此基础上 ,探讨了高寒干旱与半干旱地区土地沙漠化动态监测有关问题。研究结果表明 ,自 1 987～ 1 996年库区土地沙漠化日趋严重 ,十年来严重沙漠化土地扩大了 1 89km2 ,以每年 2 1km2 的速度扩展。土地沙漠化正过程处于强烈发展态势 ,库区土地沙漠化普遍发生。

Land desertification is one of the serious problems in environmental degeneration and has been paid a great attention to. By taking Longyangxia Reservoir area of Qinghai Province as the study area, in this paper, a dynamic monitoring of land desertification in this area is carried out by means of remote sensing (RS) and geographical information system (GIS). The results show that land desertification occurs extensively in the reservoir area, its area occupied 71.5% of the total in 1996, in which the areas of seriously desertified land, strongly desertifying land, desertifying land, and potentially desertifying land occupied 10.9%, 1.3%, 10.3% and 49% of the total respectively. Land desertification is becoming more serious, and the area of seriously desertified land enlarged for 189km 2 within 10 years. The overall trend of land desertification develops towards a positive direction although a reverse occurs in partial area. During the period from 1987 to 1996, the areas evolved from strongly desertifying land, desertifying land and potentially desertifying land to seriously desertified land in the reservoir area were 71.27, 83.51, and 83.89km 2 respectively, and the areas reversed from seriously desertified land to these three kinds were 12.13, 10.53, and 22.90km 2 respectively during the same period.