Assessment of Groundwater Pollution Vulnerability, Hazard and Risk in a Semi-Arid Region

Abstract

The Mio-plio-quaternary aquifer of the Djelfa Syncline is part of a region in Algeria which is characterized by the lack of surface water resources and located in a semi-arid climate. Since alluvial aquifers, and among them our aquifer, are the most vulnerable because of thier direct exposure to the pollution caused by the infiltrated pollutants, this work focused on the assessement of groundwater pollution vulnerability, hazard and risk. Thus, several methods were used; for this purpose, such as the DRASTIC and WQI methods mapped using a GIS. The results obtained clearly show a low to moderate vulnerability. The DRASTIC model and its validation based on the correlation with WQI revealed a low correlation (WQ I vs D I : 0.221). Since the vulnerability model does not match with the groundwater quality, pollution risk was assessed by combining vulnerabilty and hazard (i.e, water quality). The risk map illustrated three levels ranging from low to high risk. This map should be helpful in decision making and groundwater management through avoiding high risk areas.

Application of geochemical tracers for the investigations of groundwater resources in semi‐arid region (Central‐East Tunisia)

“…In this context, in order to minimize the groundwater quality degradation by the nitrate contamination, it is useful to realize a code for the good fertilizers use (Ghouili et al, 2018) and/or to reduce their excessive use in the irrigated zones. As well, the installation of new wells should take into consideration the high risk areas, which are more vulnerable to pollution (Haied et al, 2021). Furthermore, regions with moderate vulnerability (moderate WQI; Figure 7) are suitable for the implantation of new wells for human uses.…”

“…Their importance is mainly manifested by their use as valuable water resources especially for drinking purposes (Narsimha & Wu, 2019) and for livestock farming and irrigation purposes (Skevas, 2020). Actually, groundwater is the principal resource used in semi‐arid zones to supply the excessive water demand related to: (i) agricultural and industrial purposes and (ii) to drinking needs (Haied et al, 2021). The threat of water scarcity is a major problem of the modern world (Kraiem et al, 2014).…”

“…The salinization, which is one of the main dangers to groundwater in those zones, is related to the marine intrusion, climate change and industrial and agricultural activities (Rafik et al, 2021). Indeed, the climate changes that providing a global temperatures increase can cause the water resources vulnerability increase (Taabni & El Jihad, 2012, cited in Haied et al, 2021). The fast population growth has led to a significant increase in water demand to supply human needs (Kammoun et al, 2018).…”

“…For example, in order to define the more vulnerable zones to the salinity and the anthropogenic pollution, the water quality index (WQI) was computed to assess the groundwater suitability for human uses. According to Haied et al (2021), many studies have shown the importance of the correlation between natural and/or anthropogenic pollution and the vulnerability model. Recently, some models have been used in order to assess the groundwater vulnerability to pollution, such as the DRASTIC model (Chukwuma et al, 2023; Haied et al, 2021; Liang et al, 2016).…”

“…For example, in order to define the more vulnerable zones to the salinity and the anthropogenic pollution, the water quality index (WQI) was computed to assess the groundwater suitability for human uses. According to Haied et al (2021), many studies have shown the importance of the correlation between natural and/or anthropogenic pollution and the vulnerability model.…”