Water and Irrigation Management

Water and Irrigation Management

Impact of climate change in design discharge and sediment yield in urban streams (Case study: Soulghan hydrometric station)

Document Type : Research Paper

Authors
1 Shahid Beheshti university, Department of Civil, Water and Environment Engineering
2 Shahid Beheshti university, Department of civil , Water and Environment Engineering
10.22059/jwim.2026.414072.1302
Abstract
In this study, the impact of climate change on the design discharge and sediment loading in the Kan River was studied using data from the Soulghan hydrometric station. The effective discharge, the full-flow discharge, and the discharges with return periods of 1.58 and 2.33 years were calculated for current and future conditions under three climate scenarios SSP126, SSP245, and SSP585. The results showed that the effective discharge under current conditions is about 5.05 m3 / s, which transports more than 69.4 percent of the sediment, but in the future, with the decrease in the amplitude of the flows, the effective discharge will decrease to about 2.76 to 2.86 m3 / s, carrying more than 91 percent of the accumulated sediment. The sensitivity index of sediment transport to discharge also decreased from 1.32 in the past to about 0.45 to 0.49 in the future, indicating a decrease in the sharp jump in sediment with an increase in discharge. The LARS-WG model performed well in generating future climate data (r=0.97), (RMSE=2.57), and the LSTM and SVM machine learning models performed well with a correlation coefficient of about 0.90 and an NSE efficiency coefficient higher than 0.79 were able to predict discharge and sediment with acceptable accuracy. The results indicate increased flow fluctuations, increased frequency of extreme events, and redistribution of sediment load towards flows with lower amplitude due to climate change, which requires a review of the hydraulic design and management of urban waterways.
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Articles in Press, Accepted Manuscript
Available Online from 16 June 2026