Study of the distributed hydrologic response of the Claduègne catchment (Ardèche) using dense networks of rain and water level gauges
| Autor: | Hachgenei, N., Nord, Guillaume, Braud, Isabelle |
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| Přispěvatelé: | Irstea Publications, Migration, Institut des Géosciences de l’Environnement (IGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), RiverLy (UR Riverly), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | TERENO International Conference 2018 TERENO International Conference 2018, Oct 2018, Berlin, Germany. pp.1 |
| Popis: | International audience; Flash floods are amongst the most important natural hazards in Europe, particularly in the Mediterranean region creating economical damage and life risk. This study investigates the hydrological response to rainfall events over the period 2012-2015 on different spatial scales for 13 small to meso-scale partially nested Mediterranean catchments of 0.17 km2 to 42 km2 in the Ardèche region. The Claduègne catchment, which contains all the other catchments, is part of the OZCAR network. This catchment can be separated into two distinctively different parts with a basaltic plateau in the upstream part and sedimentary rock in the downstream part (each about 50%). The sub-catchments are distributed over these two parts and different land use forms (forest, cultivated soils and grasslands). For most of the sub-catchments, no discharge rating curve exists, so the focus of the analysis mainly lies on the time component of the hydrological response as well as on descriptors of the rainfall-runoff event and catchment properties. Several characteristic times were calculated for each catchment based on a set of 49 to 158 events depending on the catchment and various statistical methods were applied in order to estimate the importance of different factors on the hydrological response on two levels: (A) inter-comparison of the catchments with regards to their properties and averaged event characteristics. (B) comparison of the storm events for each catchment considered separately with regards to the rain characteristics, initial degree of wetness and saisonnality. Besides the catchment's size, we found the geology to be an important factor influencing the catchments' response, with the catchments in the sedimentary part reacting faster. The precipitation was shown to be typically more intense for short time steps (e.g. hourly) in the sedimentary part of the catchment. On the catchment-level, a strong seasonal variation of event characteristics was found. The most intense, shortest events take place in autumn, while the events in spring are particularly long and slow. The degree of wetness is generally much higher in winter than in summer. Furthermore, two sub-catchments have singular behaviors. One was shown to react much faster and one much slower than expected. This suggests in-situ investigations in order to understand the hydrological mechanisms. A simple estimate of lag time was shown to be able to characterize a catchment's dynamic and provide an estimate of time of concentration, if calculated for a selection of impulsive events. |
| Databáze: | OpenAIRE |
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