Drought forecasting model for future climate change effects in a regional catchment area in northern iraq

Abstract

Climate change plays a crucial role in shaping the hydrological dynamics of rivers owing to its immediate implications on the driving meteorological parameters. Therefore, Understanding climate change and its implications is essential for sustainable water resource management. This study aims to assess the extent of climate change and its effects on streamflow in the Mosul Dam watershed Under three global warming Representative Concentration Pathways scenarios (i.e., 2.6, 4.5, and 8.5) based on mean climate data extracted from four Global Circulation Models (i.e., Beijing Climate Center, China, Commonwealth Scientific and Industrial Research Organization, Australia, Met Office Hadley Center, United Kingdom, and Norwegian Climate Center, Norway). For this purpose, the stochastic weather generator model (LARS – WG) and soil and water assessment tool (SWAT) were used. The hydrological model (SWAT) was calibrated and validated for 2001-2013 and 2014-2020, respectively. The performance of the swat model according to the four statistical parameters (i.e., coefficient of determination, Nash-Sutclife, Root mean square error to the standard deviation, and percent bias test) was classified as very good for two calibration and validation processes. Additionally, results showed that the mean temperature would probably rise by 1.3, 2.4, and 4.5°C under RCP 2.6, RCP 4.5, and RCP 8.5 at the end of this century, respectively. At the end of the century, the simulated average annual precipitation decreased from 772 mm/y to 756.7 and 741.6 mm/y under RCP4.5 and RCP8.5, respectively. In contrast, under the RCP2.6 scenario, the mean annual precipitation increased to 803 mm/year. As a result, the projected mean annual streamflow decreased from 501.52 m3/s to 429.7, 391.9, and 376.6 m3/s at the end of the century under RCP2.6, RCP4.5, and RCP8.5, respectively. Finally, the study region will potentially face water shortage due to climate change, exacerbated by population growth and increased water demands from agriculture and municipalities. Therefore, this paper emphasizes the need for reevaluating and adapting to accommodate changing streamflow patterns, ensuring a sustainable water supply for human needs while protecting the environment.

Keywords

• climate change tigris river streamflow lars
• wg swat model