Investigation of flooding of downstream areas due to the occurrence of the probable maximum flood in Ghare Aghach earth dam

Subject Areas : hydraulic structures

Sayyed Ali Shahrezaie ¹ , Mahdi Radfa ² , Elham Ghanbari Adivi ³

1 - Department of Water Science and Engineering - Water Resources, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran.
2 - Department of Water Science and Engineering - Faculty of Agriculture, Shahrekord University, Shahrekord, Iran.
3 - Department of Water Science and Engineering - Faculty of Agriculture, Shahrekord University, Shahrekord, Iran.

Received: 2021-08-14 Accepted : 2021-09-13 Published : 2021-08-23

Keywords: Flood zoning, Ghare Aghach earth dam, Probable Maximum Flood, RAS Mapper Environment,

Abstract :

One of the most important issues in the field of scientific computational hydraulic aspects of the river is the routing of permanent and non-permanent flows. Investigation of flood zoning with different return periods can be named as one of the most important issues in the field of flood management. In the present study, using HEC-RAS software, the flood susceptibility of the downstream areas due to the occurrence of the probable maximum flood in Ghare Aghach dam has been investigated. The research results are displayed in the RAS Mapper environment. The results showed that contrary to what was thought, due to the fact that the overflow of Ghare Aghach dam has been controlled based on the highest probable maximum flood; so this flood will not cause failure in Ghare Aghach dam of overtopping type. The maximum flow from the dam overflow occurred 435 minutes after model simulation and is 171.72 cubic meters per second. According to the results of the Google Earth model, the flooding area of the downstream areas when has reached its peak flow; it is approximately equal to 5.73 square kilometers. The radius of flooding at the moment when has reached its peak flow relative to the coastline, around the villages of Mehrgerd and Hosseinabad is equal to 196 and 1858 meters, respectively. The main residential areas around the villages of Mehrgerd, Hosseinabad and Kasgan Sofla are approximately 60, 587 and 689 meters away from the coastline with the water flow obtained during the peak flow time, respectively.