Impact of climate change on hydrochemical properties and quality of groundwater for domestic and irrigation purposes in arid environment: a case study of Al-Baha region, Saudi Arabia

Groundwater over-exploitation, rising temperature and declined precipitation, have resulted in groundwater quality deterioration, subsequently affecting human health and agricultural productivity. Therefore, to evaluate the suitability of groundwater for domestic and irrigation purposes, groundwater samples were collected from 88 locations in Sarat Al-Baha region, Saudi Arabia. The hydrochemical characteristics were assessed to evaluate the suitability of groundwater for drinking and irrigation purposes. The results revealed that most groundwater samples were medium to highly salinity hazards; nevertheless, no sodicity hazards were expected. By using the water quality indices, 70.5% of studied waters were class II. Nevertheless, 91% of collected samples were in acceptable concentrations of heavy metals and nitrate. The saturation index showed that the groundwater was largely under-saturated with most minerals, indicating a possibility of salinity increase due to increasing the concentration of iron, calcium, magnesium, sodium, chloride and sulfate due to the dissolution of under-saturated minerals. Due to the increased salinity levels, more than 90% of the collected groundwater samples showed low quality for irrigation due to higher potential for salinity problems. Furthermore, the development of salinity of groundwater in Sarat Al-Baha could be the result of the increased temperatures and decreased rainfall. Therefore, it is recommended to implement appropriate management practices to optimize groundwater usage and decrease the potential of further deterioration in its quality. The discharge of groundwater need to be controlled, strictly preventing the drilling of new wells. It is also important to assess the suitability of planted crops, and implement proper water management practices to sustain groundwater resources in Sarat Al-Baha region. The approach used in this study can be used to alike environment worldwide.