EGU21-5502, updated on 07 Aug 2023
https://doi.org/10.5194/egusphere-egu21-5502
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Comparison of two flood forecasting approaches over High Atlas Mountains basins in Morocco

El Khalki El Mahdi1, Yves Tramblay2, Arnau Amengual3, Victor Homar3, Romualdo Romero3, Mohammed El Mehdi Saidi1, and Meriem Alaouri4
El Khalki El Mahdi et al.
  • 1Geosciences and Environment Laboratory, Cadi Ayyad University, 40000 Marrakesh, Morocco
  • 2HydroSciences Montpellier (Univ. Montpellier, CNRS, IRD), 34000 Montpellier, France
  • 3Grup de Meteorologia, Departament de Fisica, Universtat de les Illes Balears, 07001 Palma de Mallorca, Spain
  • 4The Department of National Meteorology (DMN), 20000 Casablanca, Morocco

This study aims to compare flood forecasting approaches adapted to the context of Morocco, for two catchments (Rheraya and Ourika) located in the High Atlas Mountains. We evaluated the performances of flash-flood forecasts using two approaches; one relying on event-based hydrological modelling, and the second, a generalized least squares regression model linking event rainfall, antecedent soil moisture and runoff. The meteorological forecasts considered were provided by the AROME (Application of Research to Operations at Mesoscale), ALADIN (Aire Limited Dynamic Adaptation International Development) and WRF (Weather Research and Forecasting) models. For both approaches, three soil moisture data sources (in-situ measurements, ESA-CCI remote sensing data and ERA5 reanalysis) were compared to estimate the initial soil wetness conditions before flood events. Results showed that the AROME and WRF models better simulate precipitation amounts than ALADIN, mostly due to their better ability to reproduce convective events. The comparison between the two flood forecasting approaches showed that the regression model outperforms the hydrological model-based approach, due to fewer calibration parameters and a better robustness. The best results were obtained with the combination of the WRF forecasts with antecedent soil moisture from ERA5. This type of approach needs to be tested in other basins of North Africa where data are available, in order to develop flood forecasting in these regions, which are strongly vulnerable to flash floods.

How to cite: El Mahdi, E. K., Tramblay, Y., Amengual, A., Homar, V., Romero, R., Saidi, M. E. M., and Alaouri, M.: Comparison of two flood forecasting approaches over High Atlas Mountains basins in Morocco, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5502, https://doi.org/10.5194/egusphere-egu21-5502, 2021.

Displays

Display file