Evaluating the quality of groundwater in the Zagora region, Southeast Morocco, using GIS and the Water Quality Index (WQI)

Abstract

Groundwater serves as a crucial water source for diverse human activities in arid and semi-arid areas, particularly in the Zagora region. The present research aims to assess the physicochemical parameters and their spatial distribution in the groundwater of the study region. The water quality data from nine designated wells were monitored during December 2020 and December 2021 in the Zagora region. Water samples from various wells in the Zagora region were examined for a range of physicochemical parameters. Twelve parameters related to groundwater quality, including chloride (Cl−), dissolved oxygen (O2), bicarbonate (HCO3−), sulphate (SO42-), nitrate (NO3−), nitrite (NO2−), calcium (Ca2+), magnesium (Mg2+), hydrogen ion concentration (pH), electrical conductivity (EC), sodium (Na+) and potassium (K+) were subjected to analysis. ArcGIS software was utilized to generate a themed map that illustrates the variability of the Water Quality Index (WQI) using a Geographic Information System (GIS). The WQI map demonstrated that the groundwater quality is poorer in the areas upstream. With 44.44% of groundwater tests in this area falling into the unfit for drinking category, it is not appropriate for human consumption. Moreover, water quality variations highlight anthropogenic impacts, emphasizing the need for effective management to mitigate groundwater contamination and pollution.

Keywords

• Groundwater
• physicochemical parameters
• geographic information system (GIS)
• water quality index (WQI)
• Zagora