基于GIS和PSR模型的农用地资源评价研究

利用Arc／Info和“压力-状态-响应”(PSR)模型，选取土壤污染综合指数作为一个压力指标，对江汉平原后湖地区农用地进行了环境质量评价，从而为该地区合理的土地利用规划和环境保护提供依据。引入PSR模型和特尔菲法确定样区评价因子，层次分析法计算相应因子的权系数；利用Arc／Info矢量化相关图层和进行缓冲区分析后建立空间数据库；然后根据各评价因子的属性确定其分值函数，通过对样点数据进行量化后采用多因子综合指数和法计算环境质量指数，划分级别；应用Arc／Info实现相关结果的输出。结果表明：后湖地区农用地环境质量中等偏上，其中二、三级地分别占47．27％和35．83％；通过对土壤污染状况和农用地环境质量等级进行分析，发现二者存在明显的正相关性。

Research on Cropland Resource Evaluation Based on GIS and PSR Model

The resource and environmental quality evaluation is carried out in the Houhu farm enterprise of Jianghan Plain based on Arc/Info and the press-state-response model(PSR) which selects the soil integrated pollution index as a pressure index. The evaluation results can provide gist for reasonable land-utilization programming and environmental protection. To begin with, the factors affecting resource and environmental quality are decided by Delphi and PSR model and the weight of corresponding factors is calculated by AHP method. Then Arc/Info is used to establish spatial database by digitizing relational layers and developing buffer analysis. Furthermore, according to membership function of evaluation factors, original data of the specimens and the synthetic index method, environmental quality indexes of assessment units for cropland are calculated and the quality grades are divided by frequency distribution of synthetic index values. Finally, the map and data set of results in the Houhu farm enterprise are obtained automatically with Arc/Info. Results indicate that the environmental quality in this area is in medium and high side, the percentage of area in level 2 and 3 amounts to 47.27% and 35.83% respectively. By analyzing correlation between the soil contaminated status and environmental quality of cropland, the prominent plus correlation exists between both.