Subpixel Flood Inundation Mapping Based on Spatial–Spectral Information in Irregular Regions

Subpixel flood inundation mapping (SPFIM) could handle the mixed pixels to obtain the spatial distribution of flood inundation at subpixel scale. However, the spatial–spectral information of flood inundation used by SPFIM is usually constructed in a specified rectangular local window, and the number of spectral bands utilized by SPFIM is also little. To solve this problem, this letter proposes SPFIM based on spatial–spectral information in irregular regions (SSIIIRs). In SSIIR, the extended random walker algorithm is used to calculate the spatial correlation in irregular regions to obtain spatial information, and the normalized model is constructed to calculate the all spectral bands in irregular regions to yield spectral information. With the help of SSIIIRs, the flood inundation mapping result is improved. The experimental results show that SSIIIR produces the better flood inundation mapping result than the traditional SPFIM methods.