基于遥感的矿区土地荒漠化动态及驱动机制

Dynamic change of land desertification and its driving mechanism in Yushenfu mining area based on remote sensing

为探讨人类活动和自然因素在榆神府矿区土地荒漠化发展变化中的相对作用,采用1989,2002,2011年3期TM遥感数据,分析了土地荒漠化现状及动态变化,结合主成分分析法确定了人类活动和气候因素在矿区土地荒漠化发展变化中的相对作用。结果表明:1通过建立NDVI(构归一化植被指数)和Albedo(地表反射率)的空间关系,结合典型区分析,可将榆神矿区荒漠化程度分为5种类型;2矿区土地荒漠化空间分带性显著,以毛乌素沙地和黄土高原接壤带为界,矿区西部荒漠化程度较重而东部荒漠化程度较轻;3研究期矿区土地荒漠化面积不断减少,1989—2002年间减少了39.7%,2002—2011年间减少了27.7%,荒漠化程度呈逆转趋势;4荒漠化变化在空间上差异较大,矿区西部荒漠化明显逆转,东部荒漠化程度呈现逆转—发展的趋势;5人类活动、气候因素决定了本区荒漠化演化方向,其贡献率分别为62.16%,14.18%。研究结果表明,推行保水采煤技术、禁牧及植树造林等是抑制本区荒漠化发展的有效途径。

Human activities and natural factors are two kinds of driving force in land desertification. The present study attempts to identify their relative roles in the land desertification of Yushenfu coal mining area. The study utilized the three stages TM remote sensing image data of 1989,2002 and 2011 on 1 ∶ 50 000 scale for land desertification mapping and its dynamic change analysis. Combined with principal component analysis（ PCA）,the relative roles of human activities and natural factors in land desertification were identified in the study area. The results are： ① Based on the remote sensing image data,the expressions of normalized difference vegetation index（ NDVI） and Albedo can be derived to rank desertification in the study area. ② The spatial distribution of land desertification presents a clear zonation pattern in mining area,the desertification in the Western mining area is heavier than that of the Eastern part. ③Land desertification area decreases 36. 7% and 27. 7% during the periods 1989—2002 and 2002—2011 respectively,which makes the desertification show a reversal trend. ④ The spatial distribution of land desertification is very different from West to East. The very severe and severe desertification areas decrease over the time in the Western mining area obviously,while there is a trend of rehabilitation firstly and then improvement in the East.⑤ Coal mining activities and climate change account for 62. 16% and 14. 18% of the total variance,suggesting the main driving force of land desertification is human activities. The results show that water protected coal mine,grazing prohibition and tree planting are the only way to rehabilitate the land degradation in Yushenfu coal mining area.