New - April 2020 - ESPERE Version 2 

ESPERE is a Microsoft Excel 2016© application which allows to apply several commonly-used methods to rapidly and simultaneously estimate groundwater recharge. According to the available data, the user can apply and compare the results of:

• three empirical methods (Guttman, Turc and Kessler),
• three slightly different water budget methods (Thornthwaite, Dingman and Edijatno & Michel),
• the water table fluctuation (WTF) method,
• and three hydrograph separation algorithms (Wallingford, Chapman and Eckhardt).

Based on various approaches that make use of different types of data, ESPERE provides both an estimate of aquifer recharge and a confidence interval on the results. ESPERE has been designed to limit as much as possible the number and type of parameters to be provided by the user, so that it can be applied in a large number of contexts, including those where knowledge is limited. 

The first version of ESPERE (v1.52) can be freely downloaded on the BRGM website since 2016. To account for user feedbacks, ESPERE has been recently improved and new facilities were added. A new release is now available (v2.44 available in April 2020) which includes the following developments: 

1. WTF method implementation accounts for the continuously aquifer drainage (correction for the unrealized recessions are added to the water level rise); 
2. ESPERE version 2 proposes automatic estimation of several parameters such as the effective precipitation infiltration ratio for water budget methods, the specific yield for WTF, the recession coefficient and BFImax for the hydrograph separation algorithms; 
3. The Edijatno & Michel water budget method was added in ESPERE version 2; 
4. Missing values in water level time series and discharge time series are automatically filled in. 

A User Guide is provided with this new release of ESPERE. It is a short translation of the detailed report BRGM/RP-69538-FR (in french). The User Guide rapidly describes the new facilities included in ESPERE version 2. It also comprises a step-by-step tutorial to run a simulation with ESPERE version 2. Finally, all the improvements and corrections implemented since the release 1.52 are listed in Annex.