Unplanned pumping of groundwater in the past two decades has caused many regional problems and tensions, leading to seawater intrusion into coastal aquifers. The main objective of this paper is the use of a Multi-Criteria Decision-Making (MCDM) approach combining with numerical simulation for reducing seawater intrusion in the Tajan coastal aquifer located on the southern seashores of the Caspian Sea, Iran, taking into account economic, social, and environmental issues. The MODFLOW code was used to simulate the groundwater flow. MT3DMS and SEAWAT codes were used to simulate the solute transport and seawater intrusion. A 10-year period from 2010 to 2020 was simulated for evaluating the current conditions and forecasting the future conditions of the aquifer. The results indicated an increase in the extent of seawater intrusion. To assess the proposed eleven curative solutions, the economic, social, and environmental criteria such as efficiency of applying of curative solutions in improvement of the aquifer's water level and efficiency of applying of curative solutions on reduction in the extent of the seawater intrusion were weighted using the Analytic Hierarchy Process (AHP) method. The results of the AHP method showed that the criterion of efficiency of applying of curative solutions in improvement of the aquifer's water level with the weight of 0.311 was the most important one. Three multi-criteria decision making methods namely, Simple Additive Weighting (SAW), Technique for Order Performance by Similarity (TOPSIS), and VIse Kriterijumska Optimizacija kompromisno Resenje (VIKOR) were utilized to select the best curative solution. The solution of 10% reduction of pumping rate and the construction of Gelvard dam in the SAW and TOPSIS methods and the solution of 3% reduction of pumping rate and the construction of Gelvard dam in the VIKOR method ranked first. Combined techniques namely, the Rank Average Method, Borda's Method, and Copeland's Method were used to develop a consensus on prioritizing curative solutions for the Tajan Aquifer. The results of these techniques showed that the solution of 10% reduction in pumping rate along with the construction of the Gelvard dam was the best. The results of simulating this solution demonstrated a 1.91 m improvement in the groundwater level of the aquifer in the MODFLOW code and a 361.5-m recede in seawater intrusion length along the coast in the SEAWAT code.

过去二十年来无计划地抽取地下水造成了许多区域问题和紧张局势，导致海水侵入沿海含水层。本文的主要目标是使用多标准决策 (MCDM) 方法结合数值模拟来减少位于伊朗里海南部海岸的 Tajan 沿海含水层的海水入侵，同时考虑到经济、社会和环境问题。MODFLOW 代码用于模拟地下水流。MT3DMS 和 SEAWAT 代码用于模拟溶质运输和海水入侵。模拟了 2010 年至 2020 年的 10 年期间，以评估含水层的当前状况并预测含水层的未来状况。结果表明海水入侵的程度有所增加。为评估提议的 11 种治疗方案，对经济、社会和环境标准进行加权，例如使用治疗溶液改善含水层水位的效率和使用治疗溶液减少海水入侵程度的效率。层次分析法 (AHP) 方法。层次分析法的结果表明，以0.311为权重的治疗性溶液在改善含水层水位方面的应用效率是最重要的标准。利用三种多标准决策方法，即简单加法加权 (SAW)、相似性订单性能技术 (TOPSIS) 和 VIse Kriterijumska Optimizacija kompromisno Resenje (VIKOR) 来选择最佳治疗解决方案。SAW法和TOPSIS法中抽水量降低10%解决Gelvard大坝施工，VIKOR法中抽水量降低3%解决Gelvard大坝施工排名第一。综合技术，即等级平均法、Borda 法和 Copeland 法，被用来就 Tajan 含水层的优先治疗解决方案达成共识。这些技术的结果表明，随着 Gelvard 大坝的建设，抽水量降低 10% 的解决方案是最好的。