Groundwater Quality Patterns and Spatiotemporal Change in Depletion in the Regions of the Arabian Shield and Arabian Shelf

Abstract

Groundwater quality is a critical issue in arid and semiarid countries, where it is one of the most reliable sources of water on which people depend. Water quality is a vital concern in the Kingdom of Saudi Arabia as it affects the health of its people, the growth of its agriculture, and its economic development. In this study, the objectives were to: (1) investigate the depletion rate of groundwater storage (GWS) in the study area by using Gravity Recovery and Climate Experiment (GRACE) data from April 2002 to April 2016 to quantify terrestrial water storage; (2) determine the ionic composition of cations and anions for 24 samples (12 samples from Arabian Shield and 12 from Arabian Shelf in Saudi Arabia); and (3) assess the water quality of the aquifer. The results show a GRACE-derived GWS depletion of − 2 ± 0.13 km 3 /year. Ionic compositions reveal two main groups: group I, with well depths of 144-607 m, and group II, with well depths of 12-150 m. Group I waters (all from the Saq aquifer) appear to be fossil waters, while group II waters (alluvial aquifer) appear to be mixed waters. As illustrated by the use of a Piper diagram, 85% of the samples in Arabian Shelf are characterized as a mixed water of calcium, magnesium, chloride, and sulfate (SO 4). In the Arabian Shield, 50% of the samples are characterized as Ca-Cl waters. Since most of the samples (98%) are from domestic wells used for drinking water and have the potential for radioactivity in the groundwater, it is essential to complete radioactive analysis and confirm acceptable water quality, based on the standards of the Water Health Organization and the Saudi Arabian Standards Organization. Keywords Groundwater quality • Groundwater depletion • Arabian Shield • Arabian Shelf • GRACE • Hydrochemical • Cations • Anions istry of Water and Environment, Tabuk Branch, for their help with analyzing the water quality of the samples that were used in this project.

Hydrochemical and Quality Assessment of Groundwater Resources in Al-Madinah City, Western Saudi Arabia

“…Thus, there is an option for an increase in the concentrations of soluble ions dissolved in the groundwater. This result is in agreement with the results of Al-Barakah et al [58] and Fallatah [2] on their study of Arabian Shield groundwater.…”

“…Most of the groundwater in Al-Madinah is used for agricultural purposes [45]. These results are in agreement with the study of Fallatah [2] and Sharaf [4].…”

“…Most of the groundwater in Al-Madinah is used for agricultural purposes [45]. These results are in agreement with the study of Fallatah [2] and Sharaf [4]. Based on the calculated values of the water quality index (WQI), about 3.7% of the water samples were suitable for drinking purpose (class II), and 9.3% were very poor water (class IV).…”

“…The Kingdom of Saudi Arabia (KSA), located in an arid environment, has limited renewable water resources [1]. There is a potential risk of water scarcity in the future due to a rapidly changing climate and anthropogenic activities [2]. The kingdom depends largely on the desalination of seawater and groundwater for different purposes such as drinking, irrigation, and industry [3].…”

Hydrogeophysical Study of Sub-Basaltic Alluvial Aquifer in the Southern Part of Al-Madinah Al-Munawarah, Saudi Arabia

“…It has precipitation of around 111 mm/year in the Makkah area, while the average precipitation reaches 500 mm/year in the southern parts of the country [1]. Al-Madinah Al-Munwarah is an example of the megacities in Saudi Arabia, where the surface water is scarce, while it is subjected to a water stress consumption due to the rapidly increasing population, either from local migrations or as seasonal visitors (Figure 1) [2]. This forced the governmental authorities to pump out/the fossil groundwater extensively to cover the increasing water demands for agricultural, industrial, and human activities [3].…”