Spatio-temporal characteristics of heavy precipitation events observed over the last decade on the eastern French Mediterranean coastal area

Abstract

Study region

eastern part of the French Mediterranean coastal area.

Study focus

This work focuses on the heavy precipitation events that have affected the eastern part of the French Mediterranean coastal area over the last decade and the river discharges associated with these events. The aim is to make a throughout analysis of the spatio-temporal characteristics of heavy precipitation events, and to evaluate whether a high flow event is associated with them when looking at river discharges on affected catchments.

New hydrological insights for the region

Based on radar-based precipitation grids, 158 heavy precipitation events (HPEs) affected the study area over the period 2007–2020. In addition, 65 % of HPEs were associated with a high flow event (HFE) on one or more gauged catchments. Results show that HPEs were more frequent during the beginning of summer and autumn. A large portion of autumn and winter HPEs were associated with a HFE. Looking at the spatio-temporal characteristics of the HPEs, their mean duration was 20 hours, with 42 % of the events lasting less than 6 hours. Some common characteristics among the HPEs that caused HFEs were identified: all HPEs lasting more than 30 hours and all HPEs with catchment precipitation accumulation above 150 mm were associated with a HFE.