Spatial Variability of Groundwater Quality for Freshwater Production in a Semi-Arid Area

Qi Zhang,Baohua Zhou,Fang Dong,Zhanhong Liu,Yaser Ostovari

doi:10.3390/w13213024

Abstract

Presenting groundwater quality assessment for different usages using one index is helpful to monitor the quality of this invaluable resource and reduce the cost of freshwater production, particularly in arid and semi-arid regions. The drinking groundwater quality index (DGWQI) is one the best indicators for groundwater quality assessment. Therefore, the purpose of the present research was to assess and map the groundwater quality of an aquifer for freshwater production in a semi-arid region, using GIS-based spatial analysis of DGWQI. For this goal, mean data from 70 wells collected during 2010–2018 were used. Results showed that total dissolved solids (TDS), electrical conductivity (EC), and total hardness (TH) had the highest impact on groundwater quality that exceed the permissible range for drinking purposes. Results also revealed that 42% of samples had a DGWQI value between 0 and 100 (appropriate quality class). Sensitivity analysis determined that Mg2+, EC, and TDS with highest mean variation indexes of 18.98, 20.68, and 19.04, respectively, were the most sensitive parameters in the calculation of DGWQI. According to R2 and RMSE, the ordinary kriging and spherical semi-variogram model had good performance for spatial analysis for all DGWQI, Mg2+, EC, and TDS. The DGWQI map showed that in the southern parts the groundwater (50% of the area) had unsuitable quality for drinking.

Highlights

IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
The pH varied in the range 7.30 to 8.25 (Table 1), indicating that the groundwater is mainly alkaline, which can be related to the dominant carbonate formations in the study site
This research was conducted to investigate the groundwater quality of the Marvdasht aquifer, for drinking purposes by using data collected for five years (2010–2018)

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Groundwater is a vital natural resource in the arid and semi-arid regions [1,2,3,4], where freshwater for human consumption is generally scarce [4,5,6]. Due to rapid population growth, the need for fresh water is increasing worldwide [7,8,9]. Freshwater resources are limited, and their distribution is heterogeneous. In Iran, a shortage of freshwater resources is an obstacle to economic, social, and cultural development [3,10,11,12]

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Conclusion