Quantitative analysis of morphometric parameters of Kali River basin, southern India, using bearing azimuth and drainage (bAd) calculator and GIS

Abstract This study deals with the application of visual basic program ‘bearing, azimuth and drainage (bAd) calculator’ which employs a new and easy methodology for extraction of watershed morphometric parameters. Using bAd calculator, morphometric analysis was carried out for the Kali River basin of southwest coast of India. The basin forms a part of the Western Ghats, which is an important mountain range of the Indian sub-continent and runs nearly parallel to the coast. Spatial maps of six morphometric parameters have been prepared from the results obtained. Various linear, areal, shape and relief morphometric parameters of fifth and sixth order basins have been calculated and interpreted. Majority of the sub-basins show less uniform values (~3 to 4) of Rbm which indicate the uniform and systematic branching pattern of streams. High Dd zones are found in the Western Ghats region, whereas low Dd zones are observed in the eastern part of the basin and near the estuary. The eastern part of the basin shows low Fs values, whereas NW and SW parts of the basin show high Fs values. Compared to manual measurement, bAd calculator requires minimal time to quantify the morphometric parameters. Experimental results show that the software is effective in calculating drainage parameters such as drainage density, frequency, bifurcation ratio, etc., using the text file of ESRI shapefile.