Abstract
Snow Water Equivalent (SWE) represents the amount of water stored in the snowpack. Is a strong predictor for water availability especially during the snowmelt season. In-situ measurements of SWE are difficult to conduct and are not representative due to the extreme weather conditions and the complex topography of mountains. Although current satellite missions do not provide direct SWE observation, they allow us to extract important proxy information, crucial for SWE retrieval. In this work, we propose two different approaches to reconstruct SWE over mountainous catchments through the exploiting of remote sensing data. The first approach is based on Differential Interferometry techniques. For this purpose, SAOCOM and Sentinel-1 images are used. This technique is based on the theoretical relation between interferometric phase and changes of SWE. The second approach is based on a fusion of optical and radar images with in-situ data. Different optical data (i.e., MODIS and Sentinel-2) are merged to provide high-resolution and daily information about the snow persistence, that is correlated to the snow amount on the ground. Sentinel-1 provides information about the melting phases, in detail about the runoff onset. In-situ data are also exploited to estimate the potential melting through a degree day model. The two methods allow the SWE reconstruction at a resolution of a few tens of meters. By comparing the results of both methods over the winter season in the Senales catchment (South Tyrol, Italy) a bias of 24 mm was found. An additional test site in Mendoza (Argentina) is also been studied by using of SAOCOM data.