GIS approach to scale issues of perimeter-based shape indices for drainage basins |
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| Authors: | ANDRÁS BÁRDOSSY FRIDJOF SCHMIDT |
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| Institution: | Institute of Hydraulic Engineering (IWS), University of Stuttgart , Pfaffenwaldring 61, D-70550, Stuttgart, Germany E-mail: andras.bardossv@iws.uni-stuttgart.de fridiof.schmidt@iws.uni-stuttgart.de |
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| Abstract: | Abstract Shape indices have been in use for several decades to describe the characteristics and hydrological properties of drainage basins. Due to the fractal behaviour of the basin boundary, perimeter-based shape indices depend on the scale at which they are determined. Therefore, these indices cannot objectively compare drainage basins across a range of scales and basin sizes. This paper presents an objective GIS-based methodology for determining scale-dependent shape indices from gridded drainage basin representations. The scale effect is addressed by defining a representative scale at which the indices should be determined, based on a threshold symmetric difference between two grids representing the drainage basin at different resolutions. |
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| Keywords: | drainage basin morphometry shape indices compactness index fractal geometry fractal dimension symmetric difference scale dependency |
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