Characterisation of drainage pattern and sinuosity indices of Subarnarekha Riverbasin using Remote Sensing and GIS techniques

Geological structure and topography of any basin area control the drainage pattern, similarly slope, underlying topographyanderosional capacity also affect upon the shape of a river path. The streamshaving high meandering form have more sinuous path. Subarnarekha basin, which is located inChotonagpur Plateau regionand passes through three states, viz., Jharkhand, Odisha and West Bengal,haveall kindsof drainage pattern. Present study attemptsto understand the drainage pattern and underlying factorswhich affecting the changing of sinuous path of river,with the help of topographic maps, DEM and satellite imageries. All the indiceslike-Standard Sinuosity Index (SSI), Hydraulic Sinuosity (HSI) and Topographic Sinuosity Index (TSI) are calculatedusing ArcGIS 10.6 software. The study depicts the significant inverse correlation between the sinuosity indicesand channel gradient (R2=0.47).In upper part of Subarnarekha river, sinuosity of the river ismainlymaintained by topographical inferencesbut in middle-and lower-part hydraulicfactorsbecome important.