Assessment of Groundwater Balance Terms Based on the Cross-Calibration of Two Different Independent Approaches

A reliable groundwater balance assessment is a fundamental tool for any effective resource exploitation plan. Nevertheless, some terms of the balance equation are, generally, very difficult to be estimated, even on average, especially when large and heterogeneous groundwater bodies are considered. In this work, a methodology for mutually calibrating groundwater balances carried out by means of different methods is proposed, also capable of providing an average estimation of the specific yield of the considered aquifer, as by-product. The method has been applied to the porous aquifer of the Tavoliere di Puglia located in Southern Italy. The plain is mostly exploited for agricultural uses and the aquifer represents the main source of the district water supply. A long time series of groundwater balances has been calibrated by assessing the average value of the term "inflow/outflow", which had not been previously considered. Furthermore, the average value of the specific yield of the considered aquifer has been assessed.