Emergency Action Plan for Flash Flood Due to Dambreak - Case study:
Shahrchai Dam, Urmia (Iran)
Abstract
Emergency Action Plan for Flash Flood Due to Dambreak - Case study:
Shahrchai Dam, Urmia (Iran) Seyed M. Heidaria, Seyed Jalal Heidarib a
Department of Civil Engineering, Sharif University of Technology,
Tehran, Iran. (SeyedMHeidari@gmail.com) b Department of Civil
Engineering, Betasaze Corporation, Mashhad, Iran.
(j.heidari37@gmail.com) Abstract: A large number of dams have been built
on the upstream of residential regions. Flash flood from these dams’
failure is a constant threat to the thousands of lives and
million-dollar municipal facilities in downstream. Therefore, it is
crucial to identify potentially flooded areas and develop an early
warning system for downstream cities to mitigate the loss of life and
financial damages. We prepared an emergency action plan (EAP) for flash
floods in Iran for the first time in this work. Shahrchai Dam was
selected as the case study since it is a large dam with a 220 million m2
capacity reservoir and is located close to a large city, Urmia, with
667,000 population and more than 197,000 households. We used HEC-RAS to
model dambreak for two scenarios, piping and overtopping. ArcGIS was
employed to identify flooded regions in downstream. The escape time was
estimated based on the time that first waves reach residential zones.
Time was 170 and 140 minutes for the piping and overtopping scenario,
respectively. Water depth and water velocity were mapped for each
scenario for flooded areas in downstream to identify secure shelters.
EAP was developed for residential, commercial, and municipal buildings
located in the flooded areas. Nine hospitals, four hotels, six mosques,
more than ten municipal buildings, 54 public, and private schools, and
five universities are determined within the flooded regions and
considered in the EAP. We divided these regions into five categories,
with three to five subcategories based on population and building types.
For each subcategory, we identified an evacuation plan with detailed
guidelines for residents and involved municipal organizations to avoid
chaotic behaviors, which usually happens during flash floods. Results
from this study are useful for educating people to be prepared for
disasters like flash floods. Municipal policymakers can also use the
findings to legislate required rules to protect urban areas from future
floods and reduce associated fatality and financial costs.
Acknowledgment: Authors would like to appreciate Sharif University of
Technology and Dr. Fardin Jafarzadeh for their supports.