Groundwater Models: How the Science Can Empower the Management?

Protection, restoration and development of groundwater supplies and remediation of contaminated aquifers are the driving issues in groundwater resource management. These issues are further triggered on and driven by the population expansion and increasing demands. To transform the ‘vicious circles’ of groundwater availabilities into ‘virtuous circles’ of demands, understanding of the aquifer behavior in response to imposed stresses and/or strains is essentially required. If groundwater management strategies are directed towards balancing the exploitations in demand side with the fortune of supply side, the goals of groundwater management can be achieved when the tools used for solution of the management problems are derived considering mechanisms of supply-distribution-availability of the resource in the system. Groundwater modeling is one of the management tools being used in the hydro-geological sciences for the assessment of the resource potential and prediction of future impact under different stresses/constraints. Construction of a groundwater model follows a set of assumptions describing the system’s composition, the transport processes that take place in it, the mechanisms that govern them, and the relevant medium properties. There are numerous computer codes of groundwater models available worldwide dealing variety of problems related to; flow and contaminants transport modeling, rates and location of pumping, artificial recharge, changes in water quality etc. Each model has its own merits and limitations and hence no model is unique to a given groundwater system. Management of a system means making decisions aiming at accomplishing the system’s goal without violating specified technical and non-technical constrains imposed on it. A complete groundwater management model is the combination of groundwater simulation models and the optimization methods. A management approach has its own mathematical logic and constraints complemented by the simulation models. It is simulation models, which actually impart groundwater sciences to the management to evaluate potentiality and the fate of the resource for different options and constrained cases. Thus, to meet the increasing demands of water for variety of uses when the supply-side becomes a limiting case or being dragged by the pollution threats, the uses of groundwater models to the management problems are bound to increase and new modeling techniques with inclusion of more real world complexities with improved predictive capacity are bound to dominate the decision process. N.C. Ghosh and K.D. Sharma 116