基于GIS的区域景观生态风险分析——以渭河下游河流沿线区域为例

Analysis on Regional Landscape Ecological Risk Based on GIS——A Case Study along the Lower Reaches of the Weihe River

以渭河下游河流沿线区域2000年的土地利用图为例,通过计算各景观格局指数,引入生态风险指数,利用地统计学的Kriging方法和GIS软件,对生态风险指数进行采样和空间插值,得到了基于景观结构的生态风险分布图。通过对生态风险指数进行分类,将整个区域划分为低风险区、较低风险区、中等风险区、较高风险区和高风险区5类。结果表明:高风险区主要位于由北向南的黄河水域区、自东向西流经研究区的渭河部分主河道区和大荔县沙苑农场的沙区。低风险区主要位于西安市城区、秦岭北坡海拔1300 m以上的山区和大荔县沙苑农场境内的林区。

In this paper, the image of land use in the lower reaches of the Weihe River in 2000 is used to compute the landscape pattern indices by introducing ecological risk index （ERI）. After the ERI values are sampled and interpolated using kriging method of geostatistics and GIS software, the spatial distribution image of ERI is de- rived based on the landscape structure. By classifying ERI values, five kinds of ecological risk regions, i.e. the regions with extremely low ecological risk, low ecological risk, moderate ecological risk, high ecological risk and extremely high ecological risk, are plotted in the study area. The results show the regions with high ecological risk are mainly distributed in the Yellow River area from the north to the south, along some mainstream channel sections of the Weihe River from the east to the west and in Shayuan Farm in Dali County. The regions with low ecological risk are mainly located in the urban area of Xi＇an City, mountainous region over 1 300 m a. s. 1. on northern slope of the Qinling Mountain and forested area of Shayuan Farm in Dali County. Study on regional landscape ecological risk can provide the quantitative decision-making basis and theoretic support for entironment management.