Hydrology
Leyla Babaie; Hirad Abghari; Raoof Mostafazadeh
Abstract
The occurrence of low flow and high flow periods in watersheds is a part of a river's regime. In recent years, changes in river flow and its intensification have impacted the production and utilization of river flows as well as water management, making it an important area of study. Evaluating various ...
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The occurrence of low flow and high flow periods in watersheds is a part of a river's regime. In recent years, changes in river flow and its intensification have impacted the production and utilization of river flows as well as water management, making it an important area of study. Evaluating various characteristics of the flow regime of natural rivers can help understand how river discharge changes due to climatic. In this study, changes in high flow and low flow indices at the Bitas watershed, Mahabad-chai, which monitors a naturally flowing river upstream of Mahabad Dam, were assessed for the period from 1963 to 2020. The results indicated that the Number Spell index was 144 during high flow periods and 253 during low flow periods. The Single Longest index was 1,635 for low flow periods and 163 for high flow periods. The average peak flow and average duration of peak flow indices for high flow periods were 22.6, and for low flow periods, they were 0.33. Additionally, the mean duration was 29.6 for high flow and 54.82 for low flow. According to the results, the total duration index for high flow periods fluctuated between 3 and 163, while the total duration index for low flow was 241. The findings of this study can be used to better understand changes in the natural flow regime, variations in the timing and frequency of low and high flow events, and ultimately to optimize the management of inflow to Mahabad Dam.
watershed
Ali Parvish; Hirad Abghari
Abstract
Watershed management, regardless of the role of local and state operators, will derail water and soil conservation policies and have many negative impacts and consequences in the long term. One of the water supply sources of Lake Urmia is the Baranduzchay River basin. Due to the increasing consumption ...
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Watershed management, regardless of the role of local and state operators, will derail water and soil conservation policies and have many negative impacts and consequences in the long term. One of the water supply sources of Lake Urmia is the Baranduzchay River basin. Due to the increasing consumption behavior of the population, sand mining and exploitation of this river is increasing day by day. Due to the need and importance of flood management and flood control to prevent social and economic problems, this research was carried out with the aim of studying the effects of non-standard sand mining on the hydraulic discharge of the river. The study area is located in the Baranduzchay River in West Azerbaijan Province, Urmia County. In this research, a section of the river from the geographic coordinates 490675 UTM and 4121955 UTM (upstream) to the geographic coordinates 490995 UTM and 4125550 UTM (downstream) is examined. In this research, topographic information is used before harvesting the riverbed and riverbank materials and the triangular irregular network (TIN) is extracted to verify the elevation features using the HEC-GeoRAS plugin, which is a bridge between the hydraulic model of HEC- RAS and ArcGIS: The effects of excessive sand mining on the hydraulic and hydrological properties of the river were studied. According to the research objective, the effects of extracting 1 to 2 meters of hydraulic runoff were simulated. This research showed that when the depth of the river bed increases by one to two meters, the cross section