Plinius Conference Abstracts
Vol. 17, Plinius17-87, 2022
17th Plinius Conference on Mediterranean Risks
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Changes in flood hazards in North Africa and implications for flood frequency analysis

Yves Tramblay1, El Mahdi El Khalki2, Lahcen Benaabidate3, Tayeb Boulmaiz4, Hamouda Boutaghane5, Hamouda Dakhlaoui6, Lahoucine Hanich7, Wolfgang Ludwig8, Mohamed Meddi9, Mahrez Sadaoui8, Mohamed El Mehdi Saidi7, and Gil Mahé1
Yves Tramblay et al.
  • 1HSM (Univ. Montpellier, CNRS, IRD), Montpellier, France
  • 2International Water Research Institute , Mohammed Vi Polytechnic University (UM6P), Benguerir, Morocco
  • 3Laboratory of Functional Ecology and Environment Engineering, University of Sidi Mohamed Ben Abdellah, Fes, Morocco
  • 4Materials, Energy Systems Technology and Environment Laboratory, Ghardaia University, Ghardaia, Algeria
  • 5Laboratory of Soil and Hydraulic, Badji Mokhtar Annaba University, Annaba, Algeria
  • 6Laboratoire de Modélisation en Hydraulique et Environnement (LMHE), Ecole Nationale des Ingénieurs de Tunis (ENIT), Tunis, Tunisia / Ecole Nationale d’Architecture et d’Urbanisme, Université de Carthage, Sidi Bou Said, Tunisia
  • 7L3G Laboratory, Earth Sciences Department, Faculty of Sciences and Techniques, Cadi Ayyad University, Marrakech, 40000, Morocco
  • 8Centre de Formation et de Recherche sur les Environnements Méditerranéens, CNRS, UMR 5110, Perpignan, France
  • 9Water and Environmental Engineering Laboratory (LGEE), Higher National School of Hydraulics, Blida, Algeria

Maghreb countries are strongly impacted by floods, causing twice as many deaths as in southern European countries in recent decades. However, due to the lack of data accessibility, there are no studies to analyze whether the frequency or intensity of floods are changing at the regional scale. In this work, a recent database of daily river discharge data from 58 basins located in Algeria, Morocco and Tunisia with on average 32 years of complete records over the time period 1970-2017 is considered to analyze the evolution of floods. A peaks-over-threshold sampling of flood events is considered, to detect trends on the annual frequency and the magnitude of floods. The results illustrate the complexity of conducting trend detection in a context of high inter-annual variability, with spurious trends detected in several cases due to isolated extreme events. Overall, few statistically significant trends are detected on the intensity of floods but an increase in flood frequency is detected in one-third of the basins. The results are interpreted in relation to land-use change, river regulation by dams and reservoirs, and climatic change. Recommendations concerning the use of frequency analysis approaches on floods in this region are given.

How to cite: Tramblay, Y., El Khalki, E. M., Benaabidate, L., Boulmaiz, T., Boutaghane, H., Dakhlaoui, H., Hanich, L., Ludwig, W., Meddi, M., Sadaoui, M., El Mehdi Saidi, M., and Mahé, G.: Changes in flood hazards in North Africa and implications for flood frequency analysis, 17th Plinius Conference on Mediterranean Risks, Frascati, Rome, Italy, 12–15 Oct 2021, Plinius17-87,, 2021.