嘉陵江流域土壤侵蚀变化遥感分析

Remote sensing analysis on soil erosion in the Jialingjiang basin

嘉陵江流域是长江流域水土流失较严重的地区,上世纪80年代末国家实施了“长治”工程,对包括嘉陵江中下游地区的“四大片”地区进行了有计划的水土流失综合治理。本文在全国第一和第二次全国土壤侵蚀调查的基础上,对嘉陵江流域实施“长治”工程以来近十几年来的土壤侵蚀变化状况进行了对比分析,结果表明嘉陵江流域侵蚀面积和侵蚀总量都明显减少,其中土壤侵蚀面积减少了11 087.3km2,而土壤侵蚀总量减少了5 746.7万t/a。同时对嘉陵江流域侵蚀变化的原因进行了分析,研究表明近十几年来,流域生态环境的改善,尤其是林地和草地面积的增加是其土壤侵蚀变化的主要原因;另外,流域各种大中型水利工程的建设以及降雨量的减少也是该流域土壤侵蚀变化的重要原因。此次研究对于检测嘉陵江流域“长治”工程的实施效果和今后流域的规划和治理具有重要的现实意义。

The Jialingjiang basin is one of severe soil erosion areas in the Changjiang basin. Based on the first and second investigations of soil erosion in China, the paper compared the spatial change of soil erosion in the past years in the Jialingjiang basin in which 1 1087.3km^2 soil erosion area was decreased and 5 746.7×10^4t/a soil erosion quantity was decreased. Meanwhile the paper analyzed the reasons of the soil erosion change which included the increase of wood- and grass-land, the decrease of rainfall, and the construction of hydro-projects. The research has an important significance in assessing the effect of ＂Changzhi＂ engineering in the Jialingjiang basin and the planning and management of basin in the future.