WSB DA: Water Surface Boundary Detection Algorithm Using Landsat 8 OLI Data
The satellite remote sensing technique provides a comprehensive output, which helps to assess the wetland condition and regional to global hydrological cycle. Several algorithms facilitate the delineation of water surface boundary, but these are computationally difficult and vulnerable to unrealistic representation of the inland wetlands. The objective of this study is to develop a semiautomated, generic, parameter free, and multispectral water surface boundary detection algorithm (WSB DA) to delineate the free water surface boundary of wetlands. The uniqueness of WSBDA is that, it is a combination of five different methods: 1) standard water indices (e.g. AWEInsh, MNDWI, and NDWI6 3) 2) the tasseled cap transformation; 3) hue saturation value (HSV) color transformation; 4) high pass filtering; and 5) vector analysis. Furthermore, this algorithm uses "ultra blue" rather than "normal blue" band of the Landsat 8 OLI image. The final output of the WSB DA is verified using detailed GPS survey points and real time photographic evidences of Sambhar Lake. Additionally, the proposed algorithm provides appropriate results for other wetland test sites, i.e. Great Salt Lake, Chilka Lake, and parts of Sundarban Delta. The WSB DA allows extraction of water surface boundary in a simple way, which is currently nonexistent for extremely shallow wetlands. Moreover, the WSB DA is a reasonable proxy for the establishment of free water surface boundary detection, which allows for avoiding extensive ground survey.
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing