This review was conducted to highlight the most influential factors and specify the trends reducing uncertainty and increasing the accuracy of soil and water assessment tool (SWAT)-based hydrological models. Although the resolution of input data on the results of SWAT-based hydrological models has been extensively determined. There is still a gap in providing comprehensive review framework to be emerged for identifying the impact of the data resolution and accuracy. The factors taken into consideration in this study were the impact of digital elevation model (DEM) resolution, soil data resolution, land use and land cover (LULC) resolution, and the impact of weather data resolution. Identifying the best DEM resolution depends on the watershed response and hydrological processes. However, for sediment yield estimation, more attention should be paid to the accuracy of soil data. Furthermore, the impact of LULC resolution on the accuracy of streamflow is still not sufficiently understood, whereas fine resolution is required for an accurate simulation of the sediment yield. Sub-daily precipitation data is essential for an accurate estimation of streamflow. Despite the fact that climate forecast system reanalysis (CFSR) and tropical rainfall measuring mission (TRMM) are the most widely used climate products, climate hazards group infrared precipitation with station data (CHIRPS) produces an adequate estimation for streamflow when there is insufficient gauged data. However, other aspects have not been deeply taken into consideration, including the interactive and complementary impacts of these factors. Thus, more attention and focus should be given to these issues. This review and evaluation can be a significant guide for selecting the suitable input data to implement efficient SWAT-based watershed models.

HIGHLIGHTS. The research introduces pre-dam construction investigation.No previous studies explain the impact of climate change on streamflow and sediment yield

Makhool Dam is a proposed structure on the Tigris River in the Salah al-Din Governorate, northwest of Baiji. The reservoir's sediment sources encompass the Tigris River, the Greater Zab River, and the Lesser Zab River. Climate change exerts a significant influence on both sediment accumulation within the dam reservoir and associated water resources. This paper specifically investigates the impact of climate change on sediment dynamics within the Makhool Dam reservoir. HEC-RAS 6.3.1 has been used to simulate the sediment dynamics and flow for the three rivers entering the reservoir. The SSP2-4.5 and SSP5-8.5 emission scenarios were applied to the 2021-2040, 2041-2060, 2061-2080, and 2081-2100 of 2021–2100. The calibration process of the model was performed using recorded water surface elevation measurements. The model was validated using the sediment concentrations at the proposed Makhool Dam. The sediment mass decreases along the rivers from upstream to downstream. The sediment mass is anticipated to decrease by approximately 20% and 35% from 2021 to 2100 under the SSP2-4.5 and SSP5-8.5 scenarios, respectively. For the studied future period, the estimated annual sediment deposition under the SSP2-4.5 and SSP5-8.5 scenarios is around 22×106 tons and 19×106 tons, respectively. In addition, under these scenarios, the potential life of the Makhool Reservoir is expected to be 95.7 and 109.5 years, respectively. The findings of this paper can play a vital role in supporting planners and decision-makers in performing efficient strategies for climate change adaptation and mitigating the impact of climate change.