在总结前人关于海水入侵危险性评价研究的基础上,提出了基于GIS的层次分析法和模糊综合评判法,并以深圳市宝安区为例建立了海水入侵危险性评价体系。首先研究了宝安区海水入侵现状;然后选取了含水层结构、地下水氯离子质量浓度、地下水水位、地形地貌、与海岸线距离、地下水开采、土地利用类型7个评估因子;再利用层次分析法确定了各评估因子的权重,根据模糊综合评判法的原理,经过模糊运算得到危险性级别;最后运用GIS空间分析功能实现了海水入侵灾害危险性区划。结果表明:评价结果与该地区的海水入侵现状吻合较好。高危险区和较高危险区面积达107.77 km2,占研究区总面积的46.7%。
By reviewing previous studies on risk evaluation of seawater intrusion, the fuzzy hierarchy comprehensive evaluation based on GIS is proposed and risk evaluation system for seawater intrusion is developed by the example of the Bao'an District of Shenzhen City. Based upon the analysis of current seawater intrusion in the study area, 7 evaluation factors are selected for risk assessment, including aquifer structure, the concentration of Cl^-, groundwater level, geomorphology, the distance of coastline, groundwater exploitation and land use types. Then, after using the analytic hierarchy process to ascertain the weight value of each evaluation factor, the risk level is obtained by fuzzy calculation according to the theory of the fuzzy comprehensive assessment. Finally, the risk regionalization of seawater intrusion is carried out with aid of spatial analysis in GIS. The results show that, the risk zonation matches well with the current situation of seawater intrusion. The total area of high-hazard and relatively high-hazard zone is about 107.77 km^2, accounting for 46.7% of the study area.