黄土丘陵区燕沟流域土地利用变化与优化调控

采用GIS空间分析技术，分析和概括了1966－2000年期间燕沟流域土地利用变化时空过程及其基本特征：解析了土地利用变化的主要成因；总结了1997年以来土地利用结构优化调控的主要特点；评价了土地利用结构优化调控后的生态环境效益、经济效益及其可持续发展性。籍此希望揭示出黄土丘陵区土地利用变化与优化调控所具有的一些共性特点和规律。

Land Use Change and Its Regulation of Yangou Watershed in Loess Hilly-gully Region

Based on the topographic map in 1966, remote sensing image in 1988 and land use survey in 2000, three land use maps were made in Yangou watershed. And assisted by spatial analysis techniques of GJS, the spatial and temporal differentiation of land use change was analyzed in that watershed. As a result, this paper found: (1)Land use change of Yangou watershed could be divided into three phases from 1949 to 2000. The main character of prophase (1949-1988) was that slope land was expansively cultivated and natural forestland was continuously destroyed. The land use structure of the watershed was steady comparatively in 1989 to 1996. The key period of regulating land use structure of the watershed was in 1997 to 2000. Land use structure during the period showed sharp changes along with the reduction of vast farmland, a speedy increase in orchard and got-up grassland and a increase in open woodland. (2)During 1997 to 2000, the important measures of regulating land use structure of the watershed included formulating the operating rules, drafting the practicable plan, regulating the land use structure based on the topographic slopes, selecting and fostering rural industries and playing the rational roles of administrators, researchers and farmers. (3)The benefit analysis of soil & water conservation and rural economic development based on the land use scenario in 2000 indicated that the percentage of reduction sediment was 80%, that of permanent vegetation cover was 78.48%, per capita GDP was 1541 yuan(RMB) in 2000 and 4311 yuan in 2010. Its rural economic development was verified to be sustainable by predicting the changes of per capita basic farmland, orchard area and sheep in 2040.