水保监测与应用技术基于RS和GIS的敦煌市沙漠化动态监测

目的]研究敦煌市沙漠化动态变化特征,为敦煌市沙漠化防治和文物保护工作提供理论依据.方法]基于遥感和GIS技术,选取2004和2009年的TM和ETM遥感数据进行调查判读.结果]敦煌市沙漠化土地面积为1.97×106 hm2,占土地总面积的73.8％;研究期内沙漠化土地总面积减少9 102.59 hm2,年变化率-0.001％;极重度沙漠化向重度、中度和轻度沙漠化转变,沙漠化程度整体减轻.结论]研究区植被盖度有所好转,沙漠化程度在减缓,但土地沙漠化趋势尚未根本改变,防沙治沙仍是敦煌市的长期任务.

Desertification Monitoring of Dunhuang City Based on GIS and RS

Objective] Studying the dynamic change of desertification in Dunhuang City in order to provide a support for desertification prevention and cultural relics protection. Methods] Based on the remote sensing data and geographic information system, the TM and ETM images were determined by field investigation and man-machine interactive interpretation. Aerial land desertification information of Dunhuang City from 2004 to 2009 were extracted. Results] There were 1.97×10⁶ hm² desertification land in the whole city, covered 73.8% of the total land area. The total desertification land was reduced about 9 102.59 hm² during the study period, the annual decrease ratio is -0.001%.Very severe desertification lands reversed to severe, moderate and light desertification land. The desertification was alleviated largely. Conclusion] Vegetation coverage is improved in the study area, which made the desertification slowed down and reversed, but desertification had not been fundamentally changed, desertification prevention will still be a long-term task for Dunhuang City.