考虑坡度因子与时序问题的小流域退耕还林时空决策分析

实施退耕还林是中国的一项重大生态工程。退耕还林不仅要考虑耕地的坡度因子,也要考虑时间顺序问题。研究利用SPOT-5遥感影像获取耕地信息,基于数字高程模型(DEM,Digital Elevation Model)获取坡度。利用GIS的空间分析功能,得到不同坡度范围内的耕地分布。经统计,35°以上耕地6.05 hm2是首先需要退耕还林的区域;25°~35°范围的坡耕地为220.45 hm2是必须退耕还林的区域;15°~25°范围的坡耕地2 373.15 hm2,是退耕还林的备选区。本研究为小流域的退耕还林时空决策分析提供了参考和借鉴。

Time-Spatial Decision-Making Analysis about Returning Farmland to Forest in Little Valley Considering Slope Factor and Time Sequence

The implementation of returning farmland to forest is an important ecological engineering in China.It should not only con-sider the slope factor of cultivated land, but also want to consider the time sequence problem.In this article, farmland information was obtained according to SPOT-5 image.Slope was obtained based on DEM ( Digital Elevation Model) .Using GIS ( Geographic Infor-mation System) spatial analysis, get farmlands within different slope.There are 6.05 hm2 farmlands above 35°, which are the first need of the region returning farmland to forest.Farmlands within 25°~35°are prerequisite returning farmland to forest regions, and its area is 220.45 hm2 .Farmlands within 15°~25°are alternative returning farmland to forest regions, and its area is 2 373.15 hm2 . This research can provide reference for time-spatial decision-making analysis of returning farmland to forest in the small watershed.