Keywords
Groundwater recharge; estimation; uncertainty; ESPERE
Location
Session B5: Managing Uncertainty
Start Date
11-7-2016 5:10 PM
End Date
11-7-2016 5:30 PM
Abstract
Groundwater resource assessment is a major concern for water managers who have to balance water demands and resources at a basin or territory scale. One operational way to address this question is to estimate the part of recharge which is linked to precipitation. Many methods to estimate groundwater recharge are described in the literature, varying in terms of time scale and the nature of the data they treat. They do not always provide a suitable estimate of uncertainty. To obtain both a realistic estimation of groundwater recharge and a confidence interval at the hydrogeological basin scale, we propose a multi-method approach combined with a gridded water budget approach at the system scale. Firstly, ESPERE, a recharge estimation tool combining several analytical methods has been developed and then applied to nine French hydrogeological case studies. The methods implemented in ESPERE are based either on climate data, discharges or piezometric levels time-series processing. This first approach addresses uncertainties linked to the estimation methods themselves. It also highlights the variability of recharge due to the interannual variability of meteorological data. Then, a spatialized approach was applied, in order to address spatial variability of meteorological data and parameters that control the water infiltration toward the aquifer. It relies on numerical treatments chaining cartographic data processing and water budget calculation with a resolution of 8 km. The combination of both approaches allows providing recharge time series at the system scale, homogeneous recharge maps at the regional scale and uncertainty estimation associated to the calculation methods.
Included in
Civil Engineering Commons, Data Storage Systems Commons, Environmental Engineering Commons, Hydraulic Engineering Commons, Other Civil and Environmental Engineering Commons
Groundwater recharge and associated uncertainty estimation combining multi-method and multi-scale approaches
Session B5: Managing Uncertainty
Groundwater resource assessment is a major concern for water managers who have to balance water demands and resources at a basin or territory scale. One operational way to address this question is to estimate the part of recharge which is linked to precipitation. Many methods to estimate groundwater recharge are described in the literature, varying in terms of time scale and the nature of the data they treat. They do not always provide a suitable estimate of uncertainty. To obtain both a realistic estimation of groundwater recharge and a confidence interval at the hydrogeological basin scale, we propose a multi-method approach combined with a gridded water budget approach at the system scale. Firstly, ESPERE, a recharge estimation tool combining several analytical methods has been developed and then applied to nine French hydrogeological case studies. The methods implemented in ESPERE are based either on climate data, discharges or piezometric levels time-series processing. This first approach addresses uncertainties linked to the estimation methods themselves. It also highlights the variability of recharge due to the interannual variability of meteorological data. Then, a spatialized approach was applied, in order to address spatial variability of meteorological data and parameters that control the water infiltration toward the aquifer. It relies on numerical treatments chaining cartographic data processing and water budget calculation with a resolution of 8 km. The combination of both approaches allows providing recharge time series at the system scale, homogeneous recharge maps at the regional scale and uncertainty estimation associated to the calculation methods.
