A geochemical study on the usability of wells water south Sinjar Mountain, Northern Iraq

Abstract

Groundwater is critical in countries with arid to semi-arid climates and limited surface water availability. Groundwater use is strongly related to its quality. The most important elements influencing groundwater quality are the type of underlying rock, the amount of rainfall, and the type of soil through which surface water seeps into subsurface layers. The study area extends south of Sinjar Mountain and toward the town of Baaj. It is around 60 kilometers long and 30 km wide. The water catchment region on Sinjar Mountain’s southern flank replenishes groundwater. Residents in this area rely on well water to support their civil and agricultural needs due to a lack of surface water and poor rainfall, which can fall below 350 mm/year on average. Chemical analyses (Ca2+, Mg2+, Na+, K+, HCO3-, SO42-, Cl-, NO3-) and physical tests (electrical conductivity (E.c.) and total dissolved salts (TDS)) were used to estimate the drinking water quality index (WQI) and irrigation water classification parameters (percentage of sodium adsorption, SAR; percentage of sodium, SSP; percentage of magnesium, MAR; Permeability Index, PI, and Kelly’s Ratio, KR). The upper part of the investigated area represents an underground water reservoir in limestone strata, which are designated as good for drinking purposes, encouraging the development of many residential complexes in the region. The lower section depicts groundwater reservoirs in the evaporite strata, as well as the influence of infiltrated water containing the dissolving products of gypsum and carbonate rock fragments, which are classed as poor to unsuitable for drinking. Most wells indicated that their water was appropriate for irrigation. This serves to revitalize agricultural operations in the region, whether through supplementary irrigation or irrigation of farms distributed around the region.