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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.

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Abstract
In this research, while studying climate conditions in the current period and analyzing changes in temperature, precipitation level, and the sunlight received, current conditions were also analyzed based on daily data from synoptic stations in the region, which had meteorological data recorded for at least 30 years. Given the environmental conditions necessary for the growth of rice, the availability of its phenological data, its high-low temperature thresholds, the Degree Day systems needed for the completion of its life cycle, and the phenological processes related to its economic production, a suitable agricultural calendar was specified. During the March-July period, this calendar showed variations in different provinces. Based on the current temperature conditions and the probable continued warming trend of the planet in the decades to come, nwoDscale was applied to the output from the atmospheric general circulation model MCdaH3 under  scenario using LARS-WG5 model. In this study, years between 1969 and 1990 were used as the base period, while years between 2046 and 2065 were studied as the future period. Temperature and precipitation conditions for the future period were simulated. Obtained output was then studied and compared with temperature conditions that were suitable for the plant to grow in the region. With some differences, results showed that the agricultural calendar for rice in Gilan and Mazandaran provinces will shift to winter. Given the different temperature conditions of Golestan province, its agricultural calendar will shift to spring.