STM Journals Peer-reviewed research from Consortium e-Learning Network

Journal of Water Resource Engineering and Management

Groundwater Darcy Velocity from underground Temperature: A Focus on the City of Turin (NW Italy)

  1. Diego Barbero
  2. Andrea Maroni
  3. Sandra Peyrot

Abstract

We report on an application of a methodology for inferring water transfer in a shallow aquifer by using analytical models of interpretation of heat transport by advection and conduction in permeable horizons. In this research, we highlight as the statistical interpretation of thermal data is a tool to obtain a quantitative estimation of the horizontal component of the Darcy velocity in a shallow aquifer. This study is based on the collection of temperature data, recorded in boreholes entirely developed within the Quaternary fluvial and outwash deposits, in which the heat transfer is affected both by advection and conduction with an important contribution, in the first several meters of the subsurface, by the seasonal climatic oscillations on temperature distribution. As an example of application of the methodology, we select the city of Turin (NW Piedmont Region) where an important shallow aquifer occurs. The shallow subsoil of Turin city consists of Pleistocene fluvial and outwash sediments with gravelly and sandy texture linked to the amount of Alpine watercourses that have modeled the major Alpine fan on which the city of Turin is built. The shallow aquifer, hosted in the Quaternary cover, shows a thickness ranging between 20 and 50 meters depth. The application of the statistical analysis to thermometric data (i.e. processing also the data with disturbances connected to seasonal fluctuations) returns values with an attenuation of the Darcy velocity. The application of the method to thermometric data only affected by seasonal fluctuation returns velocity results with differences up to 4 orders of magnitude that suggests the method is not applied; whereas, the application of the analysis of the data collected below the seasonal fluctuations depth range, returns velocity results of about 10-5–10-6 m·s-1 and thermal profiles that suggest an aquifer in perfect thermal equilibrium.

Keywords

Support