陕北农牧交错带土地荒漠化动态变化研究

应用遥感技术与GIS相结合的方法,对陕北农牧交错带不同时期的遥感影像进行校正、增强和自动分类识别,得到1986,1993和2000年3个时期土地荒漠化分布图(数字地图)、空间数据库及其面积统计。结果表明,近15年来该地区土地荒漠化面积增加,严重荒漠化土地大幅度减少,中度和轻度荒漠化土地增多;荒漠化土地的时空转换频繁且复杂,耕地沙化和林地退化是土地荒漠化的主要来源,基本农田建设和生态自然恢复使荒漠化土地发生逆转,区域土地荒漠化得到有效控制,但土地生态系统还相当脆弱;其中人畜数量增加、社会经济发展是驱动荒漠化的主要因子。

Study on dynamic changes of desertification of interlaced zone for agriculture and animal husbandry in northern Shaanxi

Integrating RS with GIS,distribution maps of land desertification (digital map),space data base and their statistics in the year of 1986,1993 and 2000 were obtained by correcting,amplifying and auto classifying the RS images of interlaced zone for agriculture and animal husbandry in northern Shaanxi.The results showed that:In the last 15 years,the area of land desertification was extended and worsened.While the land of serious desertification was diminished by a big margin,the moderate and light desertification was increased;The change of time and space of desertification was frequent and complicated due to cultivated land desertification and forest land degradation;Fundamental farmland construction and ecological natural recovery reversed the land of desertification;Regional land desertification had been under control,but the land ecosystem was so fragile that desertification was liable to occur.The rising number of people and livestock and the social economic development were primary elements of causing desertification.