Abstract:
The terrain of Bharathapuzha watershed has been analysed using (DTA) to derive
various geomorphometric parameters which are of importance in hydrological applications.
The DTA was conducted using different operations especially the DEM hydro-processing
tool box of the Free and Open Source Software (FOSS) GIS software ILWIS. The
Bharathapuzha river basin taken for the study was of an area of 3844.32 km2. The Digital
Terrain Analysis of Bharathapuzha watershed resulted in the creation of slope map, aspect
map, drainage density map, stream order map, longest flow length map, sub-catchments map,
sub-watersheds of tributaries map etc. The morphometric parameters of Bharathapuzha river
basin like Stream order (Nu), Mean stream length (Lsm), Stream length ratio (Rl), Mean
bifurcation ratio (Rbm), Drainage density (Dd), Drainage texture (T), Stream frequency (Fs),
Form factor (Ff), Length of overland flow (Lg), Relief (R), Relief ratio (Rr), Basin length,
Sinuosity Index (SI) have been found. The slope of the basin varied from 0 to 70. The basin
was found to be of elongated nature with moderate relief and slopes. The extracted drainage
network was classified according to Strahler system of classification and it reveals that the
terrain exhibits dendritic drainage pattern. The study area is well drained in nature with the
stream order varying from 1 to 6. The basin is dominated by lower order streams and the total
length of the stream is maximum is first order streams. The quantitative analysis of linear and
relief parameters using GIS is found to be of immense utility in linear basin evolution, basin
prioritization for soil and water conservation and natural resource management.
