基于GIS的宁夏土壤侵蚀敏感性与景观生态风险评价

为了探究宁夏土壤侵蚀的空间差异,识别土壤侵蚀敏感性区域,利用气象、植被、DEM、土壤、土地利用等数据,结合GIS技术和Fragstats 4.2软件,构建土壤侵蚀敏感性和景观生态风险的综合评价模型,对研究区进行了土壤侵蚀和景观的综合生态风险评价与分析。结果表明:(1)在综合风险评价中,宁夏由低到高5个风险等级的面积占比依次为34.97%,33.56%,15.03%,11.57%,4.88%。(2)从县域尺度上看,高风险区集中分布在西吉、彭阳、隆德部分地区; 较高风险区分布在南部山区及盐池最南部; 中等风险区主要分布在海原、同心等地,较低等级以下风险区在各县(区)均有分布。(3)宁夏耕地、草地面积占比最大,共计占比达69.7%,在不同土地利用类型中,各风险等级占比不同。由此可知,宁夏土壤侵蚀敏感性空间分布差异显著,低、较低风险等级区域分布范围广泛。

A GIS-based Soil Erosion Sensitivity and Landscape Ecological Risk Assessment in Ningxia,Northwestern China

In order to explore the spatial differences of soil erosion in Ningxia, we identified soil erosion sensitive areas, and conducted a comprehensive ecological risk assessment and analysis of soil erosion and landscape in the study area. Meteorological, vegetation, DEM, soil, land use and other data, combined with GIS technology and Fragstats 4.2 software were mainly used to build a comprehensive evaluation model of soil erosion sensitivity and landscape ecological risk. The main results are as follows.(1)In the comprehensive risk assessment, the proportions of the five risk levels from low to high in Ningxia are 34.97%, 33.56%, 15.03%, 11.57%, 4.88%.(2)On the county scale, high-risk areas are concentrated in parts of Xiji, Pengyang, and Longde; higher-risk areas are located in the southern mountainous areas and the southernmost part of Yanchi; medium-risk areas are mainly located in Haiyuan, Tongxin, etc. The risk areas below the lower level are distributed in all counties(districts).(3)Cultivated land and grassland area accounted for the largest proportion in Ningxia, accounting for 69.7% in total. Different types of land use have different risk levels. It can be seen that the spatial distribution of soil erosion susceptibility in Ningxia is significantly different, and the areas with low risk levels are widely distributed.