Hydrologic response of arid and semi-arid river basins in Iraq under a changing climate

Abstract

An assessment of the total hydrologic response of arid and semi-arid river basins to various scenarios of climate change by considering evapotranspiration, streamflow, and snowmelt is essential for sustainable management of water resources. The Diyala River Basin in Iraq has been chosen as a typical case study of dozens of river basins in arid and semi-arid regions. Here, the LASRS-WG, the Soil and Water Assessment Tool (SWAT), and the SWAT Calibration and Uncertainty Program (CUP) were used to evaluate the total response by considering three Representative Concentration Pathways (RCPs); RCPs 2.6, 4.5, and 8.5 over three periods, 2021–2040, 2041–2061, and 2061–2080, were considered. The results indicate that by the year 2080, the basin will experience a temperature increase by 6.6, 10.1, and 16.6% for RCP 2.6, RCP 4.5, and RCP 8.5, respectively. The corresponding reduction in precipitation will be 3.2, 6.4, and 8.7%, resulting in 38.8, 47.9, and 52.8% fall in streamflow for RCPs 2.6, 4.5, and 8.5, respectively. Due to the increase in temperature, an earlier and less contribution of snowmelt is expected in the projected streamflow. Our findings provide a useful reference and a guide to decision makers for developing adaption plans to sustainably manage water resources in the Diyala River Basin and other similar basins in arid and semi-arid regions.

Impact of climate change on future precipitation amounts, seasonal distribution, and streamflow in the Omo-Gibe basin, Ethiopia

“…The previous studies are supports this study's results according to (Kabobah et al, 2016), streamflow will change and decrease in the future due to climate change and its dependence on rainfall. Another study similarity suggests that future decreases in streamflow will be linked to projected decreases in precipitation (Saeed et al, 2022), as confirmed by this study's results. The change and decrease in streamflow shown by this study in the RCP 4.5 and RCP 8.5 global emissions scenarios are consistent with previous research (Amisigo et al, 2015).…”

Monitoring and analysis of snow cover change in an alpine mountainous area in the Tianshan Mountains, China

“…In arid and semi-arid areas, water derived from the melting of snow and ice is the main source of riverine recharge (Li et al, 2013;Miller et al, 2021;Saeed et al, 2022). In the context of global warming, snow and glaciers melt rapidly, which increases streamflow, resulting in many snowmelt-based flood events (Liu et al, 2015;Uwamahoro et al, 2021).…”

Potential Impact of Global Warming on Climate and Streamflow of Adhaim River Basin, Iraq

“…The Tmin, Tmax, wind speed, relative humidity, and solar radiation for Stations 1 and 2 were downloaded from Climate Forecasting System Reanalysis (CFSR). The CFSR weather data were recommended in SWAT applications in ungagged watersheds or missing data [40,32].…”

“…The projected streamflow modeled by Hilo et al [31] using the SWAT model and six Global Circulation Models (GCMs) indicated that the projected streamflow of Lesser Zab River tends to decline from 176.5 m 3 /s recorded in the period from 1980-2013 to 167 m 3 /s in the middle of the current century. Saeed et al [32] applied the Long Ashton Research Station-Weather Generator model (LARS-WG) and SWAT models in Diyala River basin using weather data for 2080 under five GCMs. The results indicated that streamflow of Diyala River tends to decrease by 38.8, 47.9, and 52.8% under Representative Concentration Pathways (RCPs) 2.6, 4.5, and 8.5, respectively, compared with observed streamflow recorded from 1990 to 2019.…”