Seasonal Monitoring of Snow Properties by WCR and up-GPR

The upward Ground Penetrating Radar (upGPR) permits to monitor in time lapse the snow properties using a single antenna or an array of several antennas, disposed on the soil and radiating upward (on the snow). Water Content Reflectometer (WCR) is a special TDR (Time Domain Reflectometer) system to monitor the electrical permittivity of soil and snow. We discuss the effectiveness of an integrated monitoring using an up-GPR with an antenna of 1500 MHz and WCR sensor on the snow and into the ground. The data acquisition refers to the winter season 2014-15, in a test site of interest for monitoring and prediction of avalanche phenonema in the Italian alps, at elevation of 2.100 m a.s.l. GPR data permit to monitor the different phases of snow accumulation and layering of the snowpack during the season, while the analisys of WCR data allow us to estimate with good accuracy density and water content of the snow. Particularly, the uppermost layers are characterized by density in the range between 250-300 kg/m3, while at deeper level, density values are around 400-450 kg/m3.