Indicateurs sur la ressource en eau estimés par une modélisation pluie-débit régionalisée : la base de données Web LoiEau

摘要

A parsimonious conceptual approach has been developed for the quantification and management of water resources in territories without information. The LoiEau Web database, presented in this article, is the result of applying this method to the outlet of more than 130 000 ungauged catchments over the French territory. The regional approach exploits recent and good quality hydro-meteorological information that is as exhaustive as possible (the SAFRAN reanalysis and the Hydro database) and is the result of methodological advances made in determining a well-optimized structure of a daily hydrological model adapted to a varied range of hydrological process, constrained by only two parameters to allow its regionalization and use on ungauged basins. The LoiEau Web database provides simulated hydrological data from 1958 to 2018 at daily time steps, from which multiple hydrological indicators are extracted to characterize water resources (low flow, seasonality, mean annual streamflow). This database is distributedviaa Web interface. Uncertainties were calculated by resampling of the observed data and allowed to calculate confidence intervals for each hydrological index on each catchment. A confidence index in the method is also proposed for each catchment in order to qualify the degree of applicability of results in the event that local specificities make them inappropriate.