Contribution of Open Access Global SAR Mosaics to Soil Survey Programs at Regional Level: A Case Study in North-Eastern Patagonia

Abstract

The Japan Aerospace Agency (JAXA) recently released multi-temporalglobal SAR mosaics derived from a 4-year data acquisition project (2007?2010) of the Advanced Land Observing Satellite (ALOS) PALSAR, L-band at 25 m spatial resolution. These open access data sets could assist traditional soil surveys and/or digital soil mapping programs undertaken at regional and subregional scales. Through improving mapping accuracy and reducing fieldwork time, together with digital identification and classification of landscape types and geomorphic features,soil survey programs could be completed over extensive areas currently lacking reliable soil information. Argentina is a country that needs to establish operational digital soil mapping (DSM) initiatives to address challenges and potential solutions of soil surveys at detailed and semi-detailed scales. These efforts could provide useful soil information to complement or update existing soil survey data, and document methods and results. Although remote sensing has been recognized as an efficient technology to support data gathering and information generation for soil and terrainmapping, the Argentine national knowledge of how to operationalize these techniques is still incomplete. Limited research has been carried out on the potential of microwave remote sensing data for spatial estimation of different topsoil properties,excepting soil moisture. This chapter intends to narrow down this knowledge gap by assessing the potential of ALOS PALSAR image mosaics for identifying and mapping land covers, as soil cartographic base, or as a value-added layer for integration in thematic soil mapping. The chapter also analyses changes in L-band backscatter overtime, and their relation to land degradation processes. To this end, a test area covering the north-eastern Patagonia region was chosen for its diversity of geology, geomorphology, soil, and land use, as well as for the existing soil expertise and an ongoing regional soil-mapping project.