Abstract
• Connection between LARS-WG and SWAT models presented successful simulation for current and future climate and hydrological systems in ARB. • ARB tend to become hotter and drier by 2080 due to global warming. • Adaptation strategies should be applied in water resources management of ARB. Global warming induces to increase of greenhouse gases in the atmosphere and plays a crucial role in determining the future trend in climatology and hydrology of a watershed. This paper aims to investigate the implications of global warming on future climate and its consequents on streamflow of the Adhaim River Basin (ARB). For this purpose, the Long Ashton Research Station-Weather Generator (LARS-WG) and Soil and Water Assessment Tool (SWAT)-Based models were implemented. The climate and hydrologic records for the period 1990-2019 were used as a Reference Period (RP) and projected to 2080 under Representative Concentration Pathways (RCPs 2.6, 4.5, and 8.5) and five Global Climate Models (GCMs). The results show that the region of ARB tends to become hotter and drier with an increase in mean temperature by 1.2, 2.9, and 4.6 °C under the considered RCPs, respectively. However, precipitation tends to decrease from 366 mm/y in RP to 320.2, 302, and 300.5 mm/y by 2080 under the considered RCPs. Consequently, the streamflow will decrease to about 28, 26, and 24 m3/s by 2080 under the considered RCPs, respectively, compared with 28.96 m3/s in RP. Therefore, adaptation strategies are highly recommended to alleviate the negative impacts of climate change, and the implications of climate change on groundwater, water demand, and adaptation plans should be investigated in future studies.