JWSS - Journal of Water and Soil Science

Excessive groundwater abstraction is a major environmental and economic challenge in Iran’s arid and semi-arid regions. This study examined farmers’ perceptions of groundwater over-abstraction and its perceived socioeconomic consequences in the Siminehroud catchment. Data from 373 questionnaires were analyzed using descriptive statistics, Mann–Whitney U tests, and chi-square tests. Effect sizes were reported, and p-values were adjusted using the Benjamini–Hochberg procedure. Overall, 41.8% of respondents believed that groundwater over-abstraction was occurring in their locality. Respondents with this perception were younger (median 48.5 versus 53 years; p<0.001), and the proportion with this perception was lower among users of piped water conveyance than among users of traditional canals (24.2% versus 45.6%; p=0.001). Both associations remained significant after false-discovery-rate adjustment. The most frequently perceived consequences of groundwater-level decline were declining farm income, loss of irrigated land, changes in cropping patterns, and increased migration. The findings indicate that groundwater management in Siminehroud should incorporate aquifer monitoring, improved water conveyance, and social interventions tailored to users’ characteristics.
 

Managed Aquifer Recharge (MAR) using treated wastewater is a viable strategy for water-resource sustainability in arid regions; however, the simultaneous assessment of its hydrogeological and economic aspects remains challenging. The objective of this study was to hydro-economically evaluate the implementation of an MAR project in the Qotb-Abad Plain by integrating numerical modeling and cost-benefit analysis (CBA). The quantitative and qualitative responses of the aquifer were simulated using the MODFLOW and MT3DMS models to estimate changes in groundwater levels, nitrate concentrations, and total dissolved solids (TDS). Economic benefits, including pumping energy savings, the value of stored water, and improvements in water quality, were evaluated alongside capital and operational costs under lower- and upper-bound scenarios. Subsequently, economic indicators, including net present value (NPV), benefit-cost ratio (BCR), internal rate of return (IRR), and payback period, were calculated. The results indicated that implementing MAR with an annual treated wastewater volume of 1.898 million m³ resulted in an approximately 4.5 m rise in groundwater level, accompanied by reductions in TDS from 1859 to 1752 mg/L and in nitrate concentration from 22.2 to 15.4 mg/L by the end of the five-year simulation period. Under the upper-bound scenario, the NPV, BCR, and payback period were 43.7 billion Rials, 1.36, and 3.23 years, respectively. In contrast, the lower-bound scenario was not economically justified, as its BCR was less than 1. Overall, integrating numerical modeling with cost-benefit analysis provides a comprehensive framework for supporting groundwater-management decision-making.