TITLE:
Quantitative Morphometric Characteristics of the Varthur Catchment Area, Bangalore Urban District, Karnataka, Using Geospatial Techniques
AUTHORS:
L. Muni Krishna, H. C. Vajrappa
KEYWORDS:
Morphometric Analysis, Varthur Catchment, Dakshina Pinakini River Basin, GIS, Remote Sensing, Watershed Prioritisation
JOURNAL NAME:
Open Journal of Geology,
Vol.16 No.7,
July
8,
2026
ABSTRACT: The Varthur Catchment area lies in the southern part of Bangalore Urban District, Karnataka, between 12˚48'24.52"N to 12˚53'59.85"N and 77˚24'59.95"E to 77˚30'6.72"E, covering an area of 284 km2. Drainage characteristics were extracted from SRTM DEM and IRS P6 LISS III imagery using ArcGIS 10.2.2, and the catchment was delineated into ten sub-watersheds. The catchment is a 5th-order basin with a dendritic drainage pattern. The mean bifurcation ratio is 3.1, total stream length is 327 km, and mean drainage density is 1.31 km/km2, indicating moderate permeability. The elongation ratio (0.064) and circularity ratio (0.53) reflect a structurally controlled, elongated basin. Hypsometric analysis yields an integral of 0.46, placing the basin in the mature stage of geomorphic development, with about 54% of the original landmass already eroded. Sub-watershed prioritisation using the composite parameter method identifies SWS-1 and SWS-7 as high-priority zones requiring urgent soil conservation measures and SWS-2, SWS-3, SWS-4, SWS-5, SWS-6, SWS-9, and SWS-10 are classified as moderate priority, indicating moderate infiltration capacity, while SWS-8 shows the lowest erosion risk. The findings provide a baseline for watershed management and sustainable land- and water-resource planning.