Predicting the alleviation of nitrate contamination in aquifers by conducting management scenarios using the PMWIN software: Application in the Andimeshk plain, Iran

Nitrate (NO3) is one of the most important contaminants of subterranean aquifers and has been stated as a worldwide concern. As available systems in Iran have failed to examine and control the quality of groundwater resources, the effective quality management of aquifers in the country is faced with many challenges. In this study, we implement management scenarios to predict the concentrations of NO3 introduction in the case study region. Firstly, NO3 was established as the main contaminant in the Andimeshk Plain (area of interest), then the quantitative model of NO3 contamination of the plain using PMWIN software was prepared, and finally, the temporal and spatial changes in the plain were investigated. Our findings showed that by reducing NO3 by around 25 and 50% in the agricultural zones, NO3 concentration drops about 2.11 and 11.87 mg/L per month, respectively. Moreover, the results of our study indicated that at a 50% NO3 decrease, the minimum and maximum concentrations of NO3 in Andimeshk Plain will be 9.48 and 38.51 mg/L, respectively, well below the actual concentrations (73.69 mg/L). Overall, we suggest that the methodology developed in this work can act as a primary step for the implementation of active NO3 reduction scenarios. [Display omitted] •On the basis of MODFLOW model, PMWIN software proved effective in simulating the NO3 concentration in the Andimeshk plain.•NO3 content in GW resources is increased during wet seasons owing to NO3 leaching.•NO3 concentrations in agricultural areas are reduced by 25 and 50 percent, or 2.11 and 11.87 mg/L per month, respectively.