Multi-objective optimal model for sustainable management of groundwater resources in an arid and semiarid area using a coupled optimization-simulation modeling.

Mahmoud Mohammad Rezapour Tabari,Mehdi Eilbeigi,Manouchehr Chitsazan

doi:10.1007/s11356-021-16918-4

Abstract

Excessive exploitation of groundwater resources can increase the concentration of pollutants in addition to the progressive drawdown of groundwater table. In this research, to achieve aquifer quantitative and qualitative (QQ) sustainable development, an optimal scenario for withdrawing from operation wells is proposed. At the first step, the aquifer QQ simulation was carried out with the GMS model. The developed code in MATLAB2018b in the second step provides the link between the simulation and the NSGA-II optimization tools. In the third step, a multi-objective coupled optimization-simulation model based on GMS and NSGA-II developed. Finally, optimal scenario was chosen based on applying the multiple criteria decision-making (MCDM) and Berda Aggregation Method (BAM). The results show that reducing the current withdrawal rate to 51.55% can establish the QQ stability of the aquifer. This decrease in groundwater abstraction has led to a 4.6m increase in groundwater level (GWL) over 3years (average 19cm per month). The spatial and temporal distribution of nitrate concentration after applying the optimal discharge of wells shows the nitrate concentration in central and eastern parts of the aquifer has greatly reduced. Developed sustainable management model can be used to provide a real operation planning of wells to improvement of the QQ status of groundwater in each unconfined aquifer.

Highlights

Groundwater resources are one of the main and most important components of water supply in the domestic, agricultural, and industrial sectors
Due to the high application of the GMS model and its very appropriate accuracy in investigating the quantitative and qualitative behavior of the aquifer, code was prepared in MATLAB environment with the aim of establishing link between this software and multi-objective optimization algorithms
Three objective functions were formulated to minimize the sum of drawdown of GWTL in drinking wells, minimize the sum of nitrate concentration in cells containing operation wells, and minimize the sum of withdrawal rate from wells during planning horizon

Summary

Introduction

Groundwater resources are one of the main and most important components of water supply in the domestic, agricultural, and industrial sectors. Many studies have been proposed and successfully applied to real-world groundwater systems since the 1970s to manage groundwater resources and create sustainable conditions using simulation and optimization tools In these models, due to the lack of access to important quality parameters such as nitrate and the complexities of aquifer quality modeling, the water quality of the aquifer is usually less considered in development of operation polices of groundwater. Due to the lack of access to important quality parameters such as nitrate and the complexities of aquifer quality modeling, the water quality of the aquifer is usually less considered in development of operation polices of groundwater These models use an aquifer simulation model (which can be an analytical solution or well-known codes such as MODFLOW) and an optimization tool to solve groundwater resource management problems. The net annual return from the basin during three strategies increased to 257% (in wet period), 167% (in normal period), and 112% (in dry period) of the present net annual return

Methods

Results

Conclusion