Direct and Inverse Modeling of Seawater Intrusion: A Perspective

Sea Water Intrusion (SWI) is one of the major hydrological problem in coastal aquifers. This global issue is aggravated by increasing demands for freshwater in coastal regions. In this paper, different approaches of modeling SWI and the parameters affecting the process of SWI are introduced. This is followed by the discussion on the numerical models to solve the complex, three dimensional (3D) groundwater and solute transport problems in coastal aquifer. The importance of considering aquifer characteristics while modeling the groundwater system for flow and solute transport is emphasized. A brief discussion on previous methodology, novelty and limitations on direct simulation of SWI are tabulated. The significant aspects to be considered while direct modeling of coastal aquifers are discussed and the recent focus of research in this area of interest are stated. In direct modeling, information on aquifer parameters are often unknown, therefore, an inverse approach is explained briefly. The previous studies relating to determistic inverse modeling for coupled groundwater flow and solute transport problems reported in literature are summarized. The insights about prior information, estimated parameter sensitivities, variances and correlations are reported. The paper identifies some of the existing gaps in the modeling of SWI based on the previous work and provides comprehensive understanding on direct and deterministic inverse SWI modeling