Modelling groundwater-stream water interactions in the Taro River hydrogeological basin (western Emilia-Romagna Regione, northern Italy)

Abstract

The Taro River Hydrogeological Basin (TRHB) is a small fandelta and alluvial fan depositional systems water bearing stack included in the Quaternary Po River Basin and located in the Western Emilia-Romagna Region of Italy, between the margin of the Northern Apennines and the Po River. The thickness of the fresh water bearing, part of TRHB, ranges from a few meters to more than seven hundred meters. Almost 90 Mm3 of groundwater and 50 Mm3 of stream water are yearly subtracted from the TRHB to sustain economic activities and drinking water demand of Parma Province population. A 3D mathematical model of TRHB has been built to evaluate the long-term sustainability of this consumption. The subsurface 3D finite element model is coupled via Cauchy type boundary conditions to a 1D finite element model of the Taro and Po rivers. This model of TRHB has been directly calibrated under transient-state conditions, simulating groundwater seepage and stream ows in the period between May 20th 2005 and October 31st 2006. Coupling of the 3D subsurface model with the 1D surface model leaded to a reliable assessment of stream-aquifer connectivity, aquifer recharge and mapping of exchange areas under the most various stages of the river flow.