Evaluation of seawater intrusion degree in Xingcheng city, Liaoning province by entropy weight method and attribute recognition model

Based on the results of field survey and sample testing,we select five groundwater chemical factors (Cl⁻, TDS, SO₄²⁻, A and SAR) as evaluation indices and uses the entropy weight–attribute recognition method to evaluate the degree of seawater intrusion in Xingcheng city, Liaoning province, China. Results show that 42% of the 50 sampling sites are mild seawater intrusion degree and 4% are serious degree. Mild intrusion areas are mainly distributed in the Heinikeng-Zhongxing-Miaohoutou village, the Hulitao-Wangjiahezi village ,the estuaries of the Yantai, Dongsha and Xingcheng Rivers, whereas serious intrusion areas are mainly distributed in the Zhoujiawopu-Qingtun-Haitao village. The consistency rate between the evaluation results of entropy weight–attribute recognition method and that of the chloride ion single index method is 66%, while the entropy weight–attribute recognition method can more accurately evaluate the distribution and degree of seawater intrusion. The obtained evaluation results could provide a scientific basis for preventing and controlling seawater intrusion and the sustainable utilization of groundwater resources in the study area.