Scale Issues in Hydrological Geomorphology and Developing Scale Invariance in Surface Flow Hydrology

ABSTRACT: It is found that basin hydrological response in relations with the drainage basin dominating geomorphological parameters is directly influenced by the scale of DEM resolution. A Scale Invariant model for the topographic index distribution (Pradhan et al., 2004a) has fulfilled a part of this gap. A scale independent relationship in flood routing models in a distributed hydrological model is yet to be developed. To overcome this problem, scale laws that govern the relation in digital elevation data resolution on upslope contributing area has been analyzed and a mathematical formulation has been derived that successfully downscaled the upslope contributing area from coarse resolution DEM to target fine resolution DEM. The method to downscale the upslope contributing area is used to obtain the similar distribution of depth, cross-section and kinematic wave celerity from different DEM resolutions in Kamishiiba catchment (210 km2) and to develop a scale invariant model in the surface flow hydrology