Hydrology of the Mediterranean and Semiarid Regions (Proceedings of an international symposium held at Montpellier, April 2003). IAHS Publ. no. 278, 2003, pp. 484–491.

1 Laboratoire Hydrosciences Montpellier (UMR 5569 CNRS-IRD-UM2), Université Montpellier II, Maison des Sciences de l'Eau, F-34095 Montpellier Cedex 5, France

2 Département Sciences de l’Environnement et Santé Publique, Université Montpellier 1, Faculté de Pharmacie, F-34060 Montpellier Cedex 5, France

Abstract Flash floods have been monitored in three small Mediterranean catchments. The temporal evolution of suspended solid, nitrogen and phosphorus concentrations has been measured. Continuous rainfall and discharge data are also available for each river. Total suspended solid, nitrogen and phosphorus loads have been calculated for twenty sampled floods. This study demonstrates that there is no significant correlation between discharge and concentration, for either suspended solids, or for total phosphorus and nitrogen. An attempt to link the measured loads to hydrological descriptors shows that the main explanatory factor is the rain depth for total nitrogen loads, the peak flow for the total phosphorus loads and the antecedent 30-day cumulative rainfall for the suspended solid loads.

Key words flash flood; Mediterranean rivers; nutrient loads; statistical analysis; suspended solid loads