An immiscible two-phase flow numerical model in the porous media is developed using the interior penalty Discontinuous Galerkin (DG) finite element method. As a novel approach, the implicit pressure explicit saturation (IMPES) in conjunction with the second-order Lax–Wendroff based on the Taylor expansion was used. Further, the exchanging numerical fluxes were stabilized using projection of the velocity field in the H (div) vectorial interpolation space for improvement of results at heterogeneities. At the end of each time step, nonphysical oscillations were removed using the modified Chavent–Jaffre slope limiter and the calculated saturation values were modified. In order to assess the performance of this novel approach, the Buckley–Leverett and Mc Worther benchmark problems were considered. The model efficiency and capabilities have also been evaluated using two test cases for high heterogeneous porous media.

The extensive exploitation of water resources in Chaharmahal va Bakhtiari province has led to a destructive impact on the water balance and quality of the region. In order to evaluate water quality of the study area, water quality parameters from 132 wells were analyzed to prepare spatial distribution maps of the IRWQI index. To analyze spatial and temporal rainfall anomalies, the SPI index was spatially interpolated using the ordinary Kriging method. Principal component analysis was used to investigate the relationship between water quality parameters. The suitability of data for PCA was evaluated by the Kaiser–Meyer–Olkin and Bartlett tests. Additionally, water balance components of the study area, including surface runoff and ground water, were simulated using the WetSpass-M model. According to the results of the IRWQI index, 54 wells, mostly located in built-up and agricultural lands, had poor quality․ Investigation of the average groundwater quality during the years 2007 to 2017 shows that the trend of groundwater quality decreased. Comparison of drought and water quality maps showed similar patterns so that in areas with extreme drought, water quality was bad. The highest and lowest recorded concentrations for nitrates were related to built-up and rangeland lands with concentrations of 35 and 21 mg/l, respectively. Comparison among land use classes showed that in the rangelands, groundwater quality was better and nitrate level was lower compared to agricultural and built-up areas. Overall, the results of this study show that water quality can be affected by land use types and water balance components.

Southern Iraq or lower Mesopotamia has a crucial role in Iraq’s economy due to its agricultural resources and unique wetland areas. Today southern Iraq, which is historically considered the birthplace of the development of early farming communities and the domestication of plants, is experiencing a drastic water resources crisis which is driven by both natural and human-induced reasons such as climate change, long periodical drought and water resources mismanagement practices. Despite the severity of the crisis, there is a lack of integrated and comprehensive assessments addressing the current state of water resources in southern Iraq. This paper aims to fill this gap by providing an in-depth review of the factors affecting water resources in the region. The current situation of water resources is analyzed using different indicators such as water availability in marshes, salinity variation along Shatt al-Arab river and surface of cultivated areas. This paper reviews previous studies, summarizes the current situation, analyzes the key challenges, and explores a range of potential solutions for further investigation. This study analysis is essential for guiding advanced research efforts that offer deeper insight into the challenges and propose practical solutions. This paper identifies key topics for future research to address the water crisis.