1. Effects of dam break on downstream dam and lands using GIS and Hec Ras: a decision basis for the safe operation of two successive dams.
- Author
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Amini, Ata, Bahrami, Jamil, and Miraki, Azad
- Subjects
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DAM failures , *DAMS , *DAM safety , *FLOOD routing , *DIGITAL elevation models , *LAND use - Abstract
Proper placement of dams along a river entails a lot of studies including the impact of the upstream dam on downstream dams and lands. In case of inaccurate placement of the dams, the flood arisen from the failure of the upstream dam break leads to the breakage of downstream dams. In this research, the reservoir volumes of two successive dams were optimized to evaluate the stability of the downstream dam and present a decision basis for dams' safety. To this end, the two successive dams of Vahdat located at the upstream of the Zhave dam, in the Sirvan basin, Kurdistan province, Iran were investigated. The HEC-RAS model was applied to the simulation of the upstream dam failure and the routing of the following flood up to the downstream dam reservoir. The digital elevation model, DEM, concerning the study area was derived. After converting DEM to Triangulated Irregular Networks, TIN, the required parameters and the lines pertaining to the cross sections were drawn on the river via ArcMap software. The cross sections were modified by field surveys, and the Manning coefficient was measured for different zones. By inputting the input hydrographs as well as the data related to the dam side wall and sluice gates, several likely scenarios were defined and performed in HEC-RAS. The scenarios were taken into account based on different volumes of water in the reservoirs along with piping and overtopping for the dam breaks. The results showed that in most situations, the upstream dam failure yields the downstream dam break. The maximum height of water in the reservoir so that it will not lead to overtopping breakage due to the upstream dam failure was 1295 m above sea level which was equivalent to 6.43 × 107 m3. In case of upstream dam failure, the water volume of the downstream dam exceeds the above-mentioned critical values, the latter would likely undergo the breakage. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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