Spatially distributed impacts of climate change and groundwater demand on the water resources in a wadi system

Abstract

Abstract. Understanding current and possible future alterations of water resources under climate change and increased water demand allows for better water and environmental management decisions in arid regions. This study aims at analyzing the impact of groundwater demand and climate change on groundwater sustainability and hydrologic regime alterations in a wadi system in central Iran. A hydrologic model is used to assess streamflow and groundwater recharge of the Halilrood Basin on a daily time step under five different scenarios over the baseline period (1979–2009) and for two future scenario periods (near future: 2030–2059 and far future: 2070–2099). The Indicators of Hydrologic Alteration (IHA) with a set of 32 parameters are used in conjunction with the Range of Variability Approach (RVA) to evaluate hydrologic regime change in the river. The results show that groundwater recharge is expected to decrease and is not able to fulfill the increasing water demand in the far future scenario. The Halilrood River will undergo low and moderate streamflow alteration under both stressors during the near future as RVA alteration is classified as “high” for only three indicators, whereas stronger alteration is expected in the far future, with 11 indicators in the high range. Absolute changes in hydrologic indicators are stronger when both climate change and groundwater demand are considered in the far future simulations, since 27 indicators show significant changes, and the RVA shows high and moderate levels of changes for 18 indicators. Considering the evaluated RVA changes, future impacts on the freshwater ecosystems in the Halilrood Basin will be severe. The developed approach can be transferred to other wadi regions for a spatially distributed assessment of water resources sustainability.

Unveiling hydrological dynamics in data-scarce regions: experiences from the Ethiopian Rift Valley Lakes Basin

“…It can simulate the quantity and quality of water resources from a hydrological response unit at the basin scale. SWAT is also suitable to assess the impact of climate change (Mahmoodi et al, 2021a), land cover change (Tigabu et al, 2019) and land use change (Wagner et al, 2023;McGinn et al, 2021), and watershed management practices on water resources (Mahmoodi et al, 2021b). Moreover, it has been proven to be capable of modeling in data-scarce regions (Wagner et al, 2012;Tigabu et al, 2023).…”

Unveiling Hydrological Dynamics in Data-Scarce Regions: A Comprehensive Integrated Approach

“…Currently, SWAT+ is tested in few watersheds across the world, where the results from SWAT+ are favorable compared to the previous model version (Wagner et al, 2022) It can simulate the quantity and quality of water resources from a hydrological response unit to basin scale. SWAT is also suitable to assess the impact of climate change (Mahmoodi et al, 2021a), land cover change (Tigabu et al, 2019) and land use change (McGinn et al, 2021, and watershed management practices on water resources (Mahmoodi et al, 2021b) Moreover, it has been proven capable of modeling in data scarce regions (Tigabu et al, 2023, Wagner et al, 2012. To depict the spatial heterogeneity of a watershed, each watershed is divided into multiple homogenous hydrological response units based on a unique combination of land-use, slope and soil characteristics (HRU).…”

Groundwater management in the state of Piauí (Brazil) on the climate change context

“…In a similar proposal, Melo and Wendland (2017), when simulating the recharge volume and the water level in the outcrop zone of the Guarani Aquifer System for citrus, pasture, eucalyptus, and sugarcane areas, showed that recharge rates will be more negatively affected in the last two, especially for the sugarcane area, due to the high evapotranspiration rates of the culture. Mahmoodi et al (2021) and Wu et al (2020) show that the combined action of climate change and demand for groundwater accentuate the negative effects on aquifer systems. It is noteworthy that Wu et al (2020) demonstrate that when considering only the effects of climate change, there was an increase in aquifer storage; however, in the scenario of climate change and demand, there was storage decay.…”