EGU22-2494, updated on 05 Jan 2023
EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Storm movement effects on the flash flood response of the Kan catchment

Shahin Khosh Bin Ghomash1, Daniel Bachmann1, Daniel Caviedes-Voullième2, and Christoph Hinz3
Shahin Khosh Bin Ghomash et al.
  • 1Magdeburg-Stendal University of Applied Sciences, Department of Water, Environment, Construction and Safety, Magdeburg, Germany
  • 2Jülich Supercomputing Centre (JSC) & Institute for Bio- and Geosciences (IBG), Forschungszentrum Jülich, Germany
  • 3Chair of Hydrology, Brandenburg University of Technology Cottbus-Senftenberg, Germany

Rainfall is a complex, spatial and temporally variated process and one of the core inputs for hydrological and hydrodynamic modelling. Most rainfalls are known to be moving storms with varying directions and velocities. Storm movement is known to be an important influence on runoff generation, both affecting peak discharge and the shape of hydrographs. Therefore, exploring the extent rainfall dynamics affect runoff generation and consequently flooded areas, can be an asset in effective flood risk management.

In this work, we study how storm movement (e.g. characterized by velocity and direction) can affect surface flow generation, water levels and flooded areas within a catchment. Moreover, the influence of rainfall temporal variability in correlation with storm movement is taken into account. This is achieved by means of numerical-based, spatially explicit surface flow simulations using the tool ProMaIDes (2021), a free software for risk-based evaluation of flood risk mitigation measures. The storm events are generated using a microcanonical random cascade model and further on trajected across the catchment area.

The study area is the Kan river catchment located in the province of Tehran (Iran) with a total area of 836 km², which has experienced multiple flooding events in recent years. Due to its semi-arid climate, steep topography with narrow valleys, this area has high potential for flash flood occurrence as a result of high intensity precipitation.

The results of this study show a range of possible magnitudes of influence of rainfall movement on the catchment´s runoff response. The resulting flood maps highlight the importance of rainfall velocity and most importantly the direction of the movement in the estimation of flood events as well as their likelihood in catchment area. Moreover, its shown that the magnitude of influence of storm velocity and direction on discharge  strongly depends on the location within the river network which it is measured.

ProMaIDes (2021): Protection Measures against Inundation Decision support.

How to cite: Khosh Bin Ghomash, S., Bachmann, D., Caviedes-Voullième, D., and Hinz, C.: Storm movement effects on the flash flood response of the Kan catchment, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2494,, 2022.