Screening of Earthen Levees using TerraSAR-X Radar Imagery

This paper presents early results of applying the TerraSAR-X multi-polarized data to the task of identifying problems on earthen levees. This application could save levee managers much time and expense in monitoring levees by prioritizing them according to urgency for closer inspection and analysis. One particular sign of potential impending levee failure is the appearance of a slough slide. Early detection of these from a remote sensing approach could save time versus direct inspection. Furthermore, the potential to use the SAR data to identify soil properties that could lead to future slides is being investigated. We are applying a number of classification algorithms to this problem, including Shannon entropy based classification and texture analysis using wavelet decomposition. Furthermore, a multi-temporal approach using imagery from successive orbits in a change-detection application shows promise in responding to changes in vegetation that correlate with the presence of a slide. The study area is a section of the lower Mississippi River valley in the southern USA, where earthen flood control levees are maintained by the US Army Corps of Engineers. Early results are promising, although additional data is needed for better assessment of the results.