Detection of aufeis-related flood areas in a time series of high resolution SAR images using curvelet transform and unsupervised classification

Due to their weather and illumination independence and due to their large area coverage at high spatial resolution, Synthetic Aperture Radar (SAR) images have been recognized as a valuable data source for the mapping and tracking of aufeis flooding events. We modified and utilized the change detection approach of [1], based on wavelet analysis to map aufeis-related flooding on the Sagavanirktok River in northern Alaska, collected in the spring of 2015. This paper provides near real-time monitoring by generating detailed flood parameters such as flood classification probabilities, flood-related backscatter changes, and flood extent. The generated flood maps show the spatial extent and day-to-day progression of the 2015 flooding event across a 1004 km 2 area, that was determined by processing a series of seven TerraSAR-X datasets. From our analysis, we learned that in early to late April, the formation of aufeis from the Sagavanirktok River crossed the Dalton Highway at several points. In late April to early May, associated warm temperatures led to open water flooding, which flooded the Sagavanirktok River at several locations. It can be argued that along the Sagavanirktok River, warm temperatures led to aufeis growth with the distribution of flow moving from the western channel to the eastern channel.