A comparative study of automatic drainage network extraction using ASTER GDEM, SRTM DEM and Cartosat-1 DEM in parts of Kosi basin, Bihar, India

Abstract The present study attempts to evaluate and compare the different open source 30 m resolution spaceborne digital elevation models (DEM) based on their automatic drainage network extraction efficiency. Digital elevation models from three satellite data i.e., ASTER GDEM, SRTM DEM and Cartosat-1 DEM have been employed for the extraction of stream networks. The study was carried out in the watershed situated in parts of Saharsa, Madhepura and Supaul district along the river Kosi, Bihar. Analysis was performed in ArcMap10.3 software wherein, three different thresholds of flow accumulation were used to assess the comparative evaluation. Morphometric parameters were analysed using geographical information system (GIS). The evaluation and quantification of morphometric parameters provide an effective basis for the comparison of extracted stream networks based on hydrological and morphological characteristics. Comparison and selection of appropriate DEM products for quantitative and qualitative hydrological studies are lacking in the present study area. This comparative study is helpful in selecting suitable DEM products out of the three commonly available free datasets for delineating streams in this floodplain with little variation in elevation and slope. The findings can be beneficial for using appropriate DEM data in various morphometric, prioritization, management and other GIS applications in parts of Kosi basin.