Effect of Evaluation Factors Selection on the Seawater Intrusion Evaluation Based on the Fuzzy Mathematic Method

Abstract

Taking Cl-, mineralization (M), salinization coefficient (A), sodium absorption ratio (SAR) and SO42- as the evaluation factors, we established a comprehensive evaluation method for seawater intrusion based on the fuzzy mathematic model. Sample data from two different sites are chosen to investigate the effect of evaluation factor selection on the overall evaluation result of seawater intrusion. The correlation analysis results show that Cl-, A and SO42- expect SAR present a good lineal relationship with M. The evaluation results of the seawater intrusion degree based on the fuzzy evaluation method is much more severe than that based on the single-factor method, indicating that the fuzzy evaluation method could be a more reliable way for the assessment of seawater intrusion. Nevertheless, whether removing the individual evaluation factor of SO42- or SAR away, some evaluation results get changed, confirming that the proper selection of evaluation factors has a significant effect on the overall evaluation result of seawater intrusion. In order to establish a reliable evaluation index system of seawater intrusion, it is necessary to do a lot of survey work to find out which evaluation factors can really reflect the seawater intrusion degree and their proper ranking values.