Mapping Spatial and Temporal Patterns of Soil Moisture with ASAR Imagery in the Alps

This study presents an analysis on the retrieval of soil moisture content from medium resolution wide swath SAR images for monitoring regional scale spatial and temporal patterns of this variable in the challenging Alpine environment. The possibility to retrieve soil moisture content from satellite high resolution SAR imagery in Alpine areas was successfully investigated in a previous contribution. The rationale behind this work is the fact that multi-scale and multi-sensor products could lead to a more general and comprehensive understanding of the phenomena at the ground, since different perspectives and trade-offs among spatial and temporal resolution can be exploited. In more detail, the analysis proposed here aims at: i) assessing the effectiveness of the proposed retrieval algorithm when applied to medium resolution wide swath SAR imagery; and ii) investigating the feasibility of mapping spatial patterns and temporal dynamics of soil moisture content at a regional scale. ENVISAT ASAR Wide Swath images acquired over the Alto Adige/Sud Tirol Province during the years 2010-2011 are used for the experimental analysis. Achieved results are compared with ground measurements and meteorological data, indicating good agreement in terms of both spatial distribution and temporal dynamics of estimated soil moisture content values.