Seyd Fateme Hashemi, Ali Shahnazari,
Volume 0, Issue 0 (3-1921)
Abstract
Huge floods carrying enormous amounts of transported silt occur annually in the Talar River's catchment area in the province of Mazandaran. In order to investigate the sediment transport from the specified watershed, samples were collected at five different time intervals, specifically on May 22nd, 2018; May 20th, 2018; May 17th, 2018; and May 16th, 2018. The study focused on two dates, 17.11 and 5.11, and a specific stretch of land measuring 16.75 km between Darya Malakala-Najjarkala and Arab Roshan, located outside the urban area. The purpose was to analyse the patterns of sedimentation and erosion throughout a five-year period (2016-2021) using the HEC-RAS model. Inspected. The sediment transport and volume of sediment were analysed and studied based on the long-term statistics of the Kiakla hydrometric station. This analysis focused on flood conditions with return periods of 2, 10, 25, 50, and 100 years for the watershed of the station. The findings indicate that the cumulative sediment input at the start of the simulation period is 0.9 million tonnes lower than the total sediment at the end of the period. Additionally, the river is susceptible to erosion in the majority of situations. Furthermore, during the initial period (22.4-24.7), the sediment's mean height measures 11 cm, with a substantial sedimentation of 6 million tonnes. The deposition during the second period (2018-05-20) amounts to roughly 1 million tonnes. In the third quarter, there is a relatively consistent pattern. During the fourth phase, the erosion conditions, in terms of both depth and volume, are unsuitable for harvesting. During the fifth phase, which lasted from 11.5 to 16.75, the erosion amounted to approximately 8.3 million tonnes. The erosion height change in the fifth interval ranges from 10 to 20 cm. All distances are measured in km from the sea. Under such circumstances, sediment removal is unfeasible, but it is advisable to consider flood management and river engineering measures.
