Determination of sensitivity of drainage morphometry towards hydrological response interactions for various datasets

A network of drainage patterns and associated morphometric analysis are important as it forms various attributes of a watershed. Analysis of these attributes is carried out by spatial analysis which is essential for studying several hydrological response interactions within the watershed catchment area. In the present work, five stream networks of a head watershed Verakhadi were derived from SOI toposheet (scale = 1:50,000), SRTM-GL1, AW3D30, GDEM-V2 and CartoDEM-V3.1. The calculated basin morphometric attributes of drainage network derived from all four 30-m-resolution satellite-based DEMs were compared with SOI toposheet-based drainage network which is essential for estimating the accuracy of watershed hydrological response to a natural event (storm). The capability of all four satellite-based DEMs to represent linear, areal and relief aspect of the drainage basin was evaluated. Morphometric parameter comparison of stream network derived from various DEMs is an indirect way of assessing the relative vertical accuracy of DEM. It is observed that DEMs with same spatial resolution can have variable morphometry derivatives due to different data acquisition and data processing techniques used for DEM generation. The outcome of this study will help to understand the complexity and susceptibility of the various morphometric factors arises while dealing with different data acquisition and processing techniques. The study suggests that SRTM-GL1 performs better in terms of drainage delineation and basin morphometry, followed by AW3D30, CartoDEM-V3.1 and GDEM-V2 when compared with SOI toposheet-derived terrain attributes.