Detection and Delineation of Water Bodies in Hilly Region using CartoDEM SRTM and ASTER GDEM Data

Detection and delineation of Water Body Area (WBA), particularly over inaccessible hilly region is not always possible in view of time, resources and cost issues. An automated procedure for detection and delineation of water bodies in the hilly region was performed using satellite-derived DEMs. CartoDEM, SRTM and ASTER GDEM data with 30, 90 and 30 m resolutions, respectively to generate the Elevation Points Features (EPF) in GIS platform. Total 7194906 EPFs were generated using these three DEMs. Contour and slope maps were also prepared to eliminate the outlier EPFs (non-water bodies) with flattered surface logic. Flattened area on DEMs, connected contour at edges of water bodies and 0° to 0.5° slopping area were considered as WBA in the region (2311 Km2) of Western Ghat (India). The nearest neighbor to cubic convolution conversion of DEMs was found useful for detection of boundary of water bodies more precisely. These results were validated from Landsat-8 satellite images and topographic maps (Survey of India). About 3.09% from CartoDEM, 2.22% area from ASTER GDEM and 4.38% from SRTM DEM were estimated as WBA. CartoDEM data can be suggested for precise detection of smaller water bodies in hilly region. Methodology formulated in this study could be used as a rapid assessment tool for detection of water bodies, especially in the inaccessible region for better water resources management.