盐池县沙漠化土地动态变化影响因素分析

通过分析宁夏盐池县土地沙漠化的资料和5个时期的陆地卫星遥感影像,研究了1961—2005年间该县的土地沙漠化动态变化规律,探讨了影响土地沙漠化动态变化的因素。研究表明:1983—1989年是盐池县土地沙漠化趋势急剧扩大的阶段;2001—2005年,除固定沙漠化土地面积在小幅增加外,流动、半固定和总的沙漠化土地面积均在减少。影响土地沙漠化动态变化的因素包括降水量、蒸发量等,但起决定性作用的是退耕还林还草、草地禁牧、禁止乱砍乱挖和植树造林等措施。

Affecting Factors of Dynamic Variation of Deserted Land in Yanchi County

The paper studies the laws of dynamic variation of deserted land in Yanchi County of Ningxia Province in period of 1961 to 2005 and approaches to the factors that effect dynamic variation of deserted land by using data of deserted land and landsat remote sensing images in the five periods.The outcomes show that a) in the periods of 1983 to 1989,it is the phase for sudden extension of the areas of deserted land;b) in the periods of 2001 to 2005,the areas of moving,semi-fixed and total deserted land are all reduced except fixed deserted land.The affecting factors include precipitation and evaporation,but the decisive factors are the conversion of cropland to forest,banning grazing,forbidding cutting trees at random and afforestation.