TITLE:
Rainfall-Runoff Simulation and Modelling Using HEC-HMS and HEC-RAS Models: Case Study Tabuk, Saudi Arabia
AUTHORS:
Ali Alsubeai, Suzette R. Burckhard
KEYWORDS:
Remote Sensing, Climate Variability, Watershed Modeling, Arid Region
JOURNAL NAME:
Natural Resources,
Vol.12 No.10,
October
21,
2021
ABSTRACT: Flooding regimes in arid regions are heavily
influenced by climate change, water shortage, water regulations, and increased
water demands. The low amount of annual precipitation due to the desert climate
may lead to false estimations of flooding hazards. This study analyzed flash
floods caused by short-intense rainstorms. The objective of this study was to
determine flood risk related to identified precipitation depths. The project
quantized the runoff corresponding to different design storms and used
hydraulics and geospatial data to determine flood elevations. The study
constructed hydrologic and hydraulic models to quantify flood hazards in the
adjacent area of Wadi Abu Nashayfah. Peak discharges for the wadi were computed
by using observed rainfall data, and the output of this process was applied to
compute water surface elevations within the flow channel. At upstream, there is a high potential of flooding when Wadi Abu Nashayfah receives a minimum of 25 mm of rain
which generates 40.60 m3/s of peak discharge, thus, at this point
the stream will overtop its banks and risking the adjacent area. In the second case, flow will
overtop its banks when the channel receives at least 35 mm of rain and peak
discharge level to 67.20 m3/s. While flow will reach bank full point
if wadi Abu Nashayfah receives 10.00 mm of rain and generates 14.80 m3/s
of streams downstream. The depth of precipitation at which the channel was
overtopped was determined in several locations. The predicted overtopping was
compared to historic events with good agreement.