GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 3.2 ___ GNGTS 2023 Detecting the hydraulic behavior of a mountain permafrost subsoil with an infiltration experiment and ERT time-lapse measurements M. Pavoni 1 , J. Boaga 1 , A. Carrera 2 , G. Zuecco 3 , L. Carturan 3 , M. Zumiani 4 1 Department of Geosciences, University of Padova, Padua, Italy 2 Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Legnaro, Italy 3 Department of Land, Environment, Agriculture and Forestry, University of Padova, Legnaro, Italy 4 Servizio Geologico, Provincia Autonoma di Trento, Italy ABSTRACT Rock glaciers are important and common permafrost morphologies found in high Alpine mountain environments (Janke et al., 2013). These geomorphological landforms consist of a coarse surface of debris and blocks that insulates a frozen subsoil layer. In Alpine areas, even if the permafrost-derived groundwater significantly concurs to the local streamflow (Wagner et al. 2016), their hydraulic behavior and their role in the catchment’s hydrology is not well known as for moraines, talus and hillslope aquifers (Pauritsch et al., 2017). To investigate runoff processes occurring in rock glacier environments, geochemical surveys of spring waters (emerging downslope of rock glaciers) have been used in the past. As shown in Fig.1, in ice‐rich rock glaciers a continuous frozen layer is typically considered as an aquiclude (Giardino et al. 1992). Krainer et al. (2007) defined a supra-permafrost flow component, derived from precipitation and snow-ice melting, and a deeper and slower sub-permafrost flow component at the bottom of an ice-rich rock glacier in the Austrian Alps. Harrington et al. (2018) estimated as unconfined aquifer an inactive rock glacier in Canada (Helen Creek, Alberta), due to the discontinuous ground ice distribution that is acting as an aquitard.