Risk Evaluation for Seawater Intrusion Based on GIS:A Case Study in the Bao'an District of Shenzhen City
Ruirui Zhao · Dizhi ke-ji qingbao · 2009
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 km2,accounting for 46.7% of the study area.