Evaluating the Impacts of Pumping on Aquifer Depletion in Arid Regions Using MODFLOW, ANFIS and ANN

Mohammed R Almuhaylan,Abdul Razzaq Ghumman,Yousry M Ghazaw,Md Shafiquzzaman,Ibrahim Saleh Al-Salamah,Afaq Ahmad,Husnain Haider

doi:10.3390/w12082297

Abstract

In arid regions, the groundwater drawdown consistently increases, and even for a constant pumping rate, long-term predictions remain a challenge. The present research applies the modular three-dimensional finite-difference groundwater flow (MODFLOW) model to a unique aquifer facing challenges of undefined boundary conditions. Artificial neural networks (ANN) and adaptive neuro fuzzy inference systems (ANFIS) have also been investigated for predicting groundwater levels in the aquifer. A framework is developed for evaluating the impact of various scenarios of groundwater pumping on aquifer depletion. A new code in MATLAB was written for predictions of aquifer depletion using ANN/ANFIS. The geotechnical, meteorological, and hydrological data, including discharge and groundwater levels from 1980 to 2018 for wells in Qassim, were collected from the ministry concerned. The Nash–Sutcliffe efficiency and mean square error examined the performance of the models. The study found that the existing pumping rates can result in an alarming drawdown of 105 m in the next 50 years. Appropriate water conservation strategies for maintaining the existing pumping rate can reduce the impact on aquifer depletion by 33%.

Highlights

Groundwater modeling for sustainable management is an important field in regions that use groundwater as their main water supply
In the case of artificial neural networks (ANN) models, comparatively better performance was observed for ANNs with 10 hidden neurons in both the two-layer and three-layer architecture, as compared with those having 5 or 15 neurons
Model run for simulation of groundwater levels

Summary

Introduction

Groundwater modeling for sustainable management is an important field in regions that use groundwater as their main water supply. The matter becomes more serious where the recharge to the aquifer is limited and the groundwater is depleting at an alarming rate (Figure 1). It is a hot issue and relevant research has been addressing various issues of groundwater worldwide [1,2,3]. There are several challenges in groundwater modeling used to provide some of the basic information for engineering designs, sustainable groundwater planning, and environmental impact assessment. Challenges exist in understanding system dynamics and the flow patterns, analyzing the groundwater responses to stresses in the system, and assessing the sustainable groundwater yield. Groundwater modeling is an area of continued research, as identified by several publications [4,5,6,7,8,9]

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Conclusion