基于GIS和USLE的鄱阳湖流域土壤侵蚀敏感性评价

水土流失是鄱阳湖流域严重的生态环境问题。以USLE模型为基础，结合鄱阳湖流域自然环境特征，确定评价指标及其分级标准。运用GIS技术，实现研究区土壤侵蚀敏感性综合评价，揭示其流域空间分异特征及规律，并对流域土壤侵蚀产生的原因进行分析，提出了调控措施。研究表明：流域土壤侵蚀敏感性主要以中度和高度敏感为主，不敏感、轻度和极度敏感所占比例较少。从空间分布上来看，极敏感地区集中分布在赣东南部的宁都县和会昌县，赣中吉安县和泰和县，赣西北的万载县，赣东北的德兴市和上饶市；高度敏感地区主要分布在赣江、抚河、信江、饶河及修水这5条河流域中、上游河流两岸和鄱阳湖滨湖地区，以及坡度<25°的坡耕地、疏幼林地；中度敏感性地区分布面积最广，在整个流域内各地貌和用地类型(除水域外)上均有分布；轻度敏感性地区主要分布在赣西南的井冈山市、万安县、赣县、大余县一带，呈月牙形分布；不敏感地区以鄱阳湖及五河沿线向四周呈辐射状分布，还包括赣西北的拓林水库、赣西江口水库和赣东洪门水库等区域。

Soil Erosion Sensitivity Assessment for Poyang Lake Basin Based on GIS and USLE

Soil and water loss is one of serious ecological and environmental problems in Poyang Lake basin.USI,E and UIS,together with basin natural environment characteristics data,were used to determine several soil erosion sensitivity factors and its criteria grade for the evaluation of soil erosion sensitivity and reveal the spatial differentiation characteristics and soil erosion sensitivity in the basin.The causes of soil erosion were analyzed and a proposal on regulatory mechanisms was put forward.The study showed that soil erosion in the study area was mainly at medium and high sensitive levels.Spatially,extreme sensitivity areas were mainly distributed in Ningdu,H uichang,Ji'an,Taihe and Wanzai Counties,as well as Dexing and Shangrao Cities.High sensitive areas were mainly located in the two sides of the middle and up stream of the Uanjiang,Fuhe,Xinjiang,Raohe and Xiushui rivers and in the lakeshore area of Poyang Lake,as well as G250 farmlands and sparse young forest lands.Medium sensitivity areas were extensively distributed in the whole basin including different types of geomorphology and landuse(except water bodies).Low sensitivity areas were mainly distributed in the Jinggangshan City and Wan'an,Uan and Dayu Counties with the crescent shaped distribution.Non-sensitive areas were centered at Poyang Lake and spread radially including Tuolin,Jiangkou and Hongmen reservotrs areas.