中尺度流域土地利用变化对土壤侵蚀的影响——以孤山川流域为例

Effects of Land Use Change on Soil Erosion in Mesoscale Watershed——A Case Study at Gushanchuan Watershed

[目的]探究中尺度孤山川流域土地利用/覆盖变化对土壤侵蚀的影响,为认识理解黄河泥沙变化,完善土壤侵蚀模型提供理论支持。[方法]根据TM影像及中国土壤流失方程(CSLE)获取流域土地利用/覆盖数据与表征土壤侵蚀的植被作用因子,通过土地利用变化转移矩阵,重点分析流域土地利用/覆盖变化引起的植被作用因子的变化。[结果]1975—1997年间,孤山川流域植被作用因子随着草地减少,耕地增加和植被覆盖度降低而增大,而在1997—2012年间,流域植被作用因子随着草地增加,耕地减少和植被覆盖度升高而增大。[结论]林地和草地是重要的林草措施,因此增加林草种植面积,对于减少土壤侵蚀具有重要意义。

[Objective]The effects of land use/land cover change on soil erosion at Gushanchuan watershed was illustrate for better understanding the dynamic of sediments in Yellow River in order to provide theoretical support for improvement of soil erosion model.[Methods]Based on the data of land use and land cover derived from Landsat TM image,and of vegetation factor derived from Chinese soil loss equation（CSLE）,transition matrix of land use change was used to analyze vegetation factor variation caused by land use/cover changes.[Results]From 1975 to 1997,vegetation factor increased with the decrease of grass land,and the increase of vegetation cover and cultivated land.While from 1997 to 2012,though opposite facts happened,i.e.,grass land and vegetation cover increased,whereas cultivated land decreased,these still resulted to increase of vegetation factor.[Conclusion]As the most important measures,grassland and forestland should be increased.This is of great significance for controlling soil erosion.