Multi-Objective Hydro-Economic Modeling for Sustainable Groundwater Management

Groundwater sustainability may refer to its exploitation and use for the present needs while maintaining the resource for future generations without unacceptable environmental, economic, and social consequences. For transitioning toward groundwater resource sustainability, specific adaptive management policies should be developed to achieve pre-specified goals. Focusing on demand side measures, this paper develops and applies a hydro-economic based multi-objective optimization model for sustainable groundwater management. Solution to the model develops a tradeoff surface between possible loss to long-term agricultural profit, groundwater level, and required energy for groundwater pumping. Farming practice and cropping pattern, quantity and timing of groundwater pumping, and energy consumption are optimized for transitioning toward long term groundwater sustainability. The simulation model is coupled with a multi-objective particle swarm optimization algorithm for developing a set of non-dominated optimal solutions for sustaining groundwater table in a groundwater basin in Isfahan, Iran. Recovery time of transitioning to groundwater sustainability is dynamically varied to assess the impact of different strategies on agricultural economy, mean annual groundwater level drop, and required energy for pumping. Results show that the optimal strategy for sustaining groundwater level at its present condition would result in 17% reduction in agricultural profit to the region. The same strategy would reduce energy use for groundwater pumping by more than 19%, compared to the business as usual strategy.