Multi-scale analysis of intrinsic soil factors from SAR-based mapping of drying rates

Intrinsic soil factors affect and are affected by the spatial variation of soil properties. Therefore, intrinsic soil factors may both characterize and serve as an indicator for soil taxonomy. Difficulties in inferring intrinsic soil properties hamper attempts to assess their variability, on both local and regional/broad scales. Radar remote sensing might facilitate a breakthrough in this field, due to its sensitivity to the soil water content. In this research, a raster Geographic Information System (GIS) methodology is developed for combining multi-temporal ERS-2 SAR and Landsat TM data, which allows the estimation of drying rate patterns in bare soil surfaces. The drying rates provide further indication about intrinsic soil properties. The multi-scale behaviour of soil-drying rates is described using the richness-area curves and characteristic curves are determined to four soil formations typical to a climatic gradient between Mediterranean and semi-arid environments in Israel. To the best of our knowledge, this is one of the first attempts to document the effect of intrinsic soil factors on the soil system at the regional scale. The results achieved here demonstrate the connection between drying rates, richness-area variation and soil hydraulic conductivity of the four soil formations.