GIS技术支持下的土地盐碱化敏感性评价

Evaluation of Sensitivity to Alkali-saline Land Supported by GIS

在生态环境较脆弱的吉林省西部地区,应用GIS多边形叠置分析技术划分了6395个评价单元,选取了6项土地盐碱化敏感性指标,将土地盐碱化的敏感程度分为非敏感、轻度敏感、中度敏感和极敏感4级。采用层次分析和二级模糊综合评判相结合的方法进行敏感性评价,并通过GIS技术实现评价结果的分区和可视化。结果表明,采用的评价方法能够有效提高评价精度。研究区土地盐碱化以中度敏感为主,轻度敏感和非敏感次之,极敏感地区占土地总面积的份额最小。

In order to evaluate the sensitivity to alkali-saline land in the West of Jilin Province with the fragile eco-environmental problems, 6 395 cells had been divided with the help of the polygon overlaying method of GIS and 6 indexes were chosen. The degree of sensitivity had been divided into nonsensitivity, low-sensitivity, high-sensitivity and the highest-sensitivity. The AHP model was used to ascertain the weight of evaluating indexes, and the Fuzzy model was used to evaluate the level of sensitivity to alkali-saline land,which could supply the useful basis to the division of the sub areas and visualization of result by GIS technology. The result showed that the above methods could improve the precision of evaluation. The alkali-saline land in the West of Jilin Province is dominated by high-sensitivity. The low-sensitivity and the nonsensitivity were take second place, and the highest-sensitivity was the least.