Sustainable exploitation of groundwater resources considering the effects of climate change and land use to provide adaptation solutions (case study of the Hashtgerd plain)

Population growth and increasing demand for water have posed a significant challenge to access to safe water resources. Climate change and land use in the not-too-distant future add to the complexity of this challenge. Therefore, it is essential to achieve reliable methods for predicting changes in aquifer storage to plan for the sustainable use of groundwater resources. This study aimed to investigate the management, protection, and sustainable use of groundwater resources under climate change and land use change conditions. In this regard, groundwater supply and demand in one of the important plains in Iran (Hashtgerd plain) for 2020 as the base year was simulated to forecast the trends until 2050 by considering climate change and land use to develop management scenarios to adapt to these conditions using the WEAP model. First, climate change prediction was performed using the HadGEM2-ES model under two emission scenarios, RCP2.6, and RCP8.5, of the IPCC Fifth Assessment Report. The LARS-WG model was used to downscale the climatic data, while land use mapping was performed using Landsat satellite images of 1990, 2005, and 2020 in ENVI 5.3 software. Then, the Markov chain method implemented in TerrSet software was used to model land use change for 2050. The effect of climate change and land use on the decrease of groundwater level was then simulated using the MODFLOW model for the period 2020-2050. In order to manage the water allocation in the area, the information obtained from MODFLOW was transferred to the WEAP model using Link Kitchen interface software. The effects of various management scenarios such as increasing irrigation efficiency, reducing the loss of drinking water distribution networks, and allocating water from the transmission line were evaluated on the adaptation to climate change and land use for a 30-year period. The results showed that with the simultaneous consideration of climate change and land use in the most critical state, the average drop in groundwater level would reach 58 m during the study period, and aquifer reserves will be reduced by more than 50%. The evaluation of management scenarios showed that their implementation not only will protect aquifer reserves but, in addition to meeting 100% of the water needs, will result in sustainable exploitation of groundwater resources.

Automated summary

Population growth and increasing demand for water pose a challenge to access to safe water resources, especially considering the complexity added by climate change and land use. This study aimed to investigate methods of managing, protecting, and sustainably using groundwater resources under changing climate and land use conditions. The results showed that effective management scenarios can protect aquifer reserves and ensure sustainable exploitation of groundwater resources.