Evaluation of morphometric parameters of drainage

Authors: Hasan Ozdemir Deanne Bird

Publish Date: 2008/02/21

Volume: 56, Issue: 7, Pages: 1405-1415

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Abstract

An evaluation of morphometric parameters of two drainage networks derived from different sources was done to determine the influence of subbasins to flooding on the main channel in the Havran River basin BalıkesirTurkey Drainage networks for the subbasins were derived from both topographic maps scaled 125000 and a 10m resolution digital elevation model DEM using geographic information systems GIS Blue lines representing fluvial channels on the topographic maps were accepted as a drainage network which does not depict all exterior links in the basin The second drainage network was extracted from the DEM using minimum accumulation area threshold to include all exterior links Morphometric parameters were applied to the two types of drainage networks at subbasin levels These parameters were used to assess the influence of the subbasins on the main channel with respect to flooding The results show that the drainage network of subbasin 4—where a dam was constructed on its outlet to mitigate potential floods—has a lower influence morphometrically to produce probable floods on the main channel than that of subbasins 1 3 and 5 The construction of the dam will help reduce flooding on the main channel from subbasin 4 but it will not prevent potential flooding from subbasin 1 3 and 5 which join the main channel downstream of subbasin 4 Therefore flood mitigation efforts should be considered in order to protect the settlement and agricultural lands on the floodplain downstream of the dam In order to increase our understanding of flood hazards and to determine appropriate mitigation solutions drainage morphometry research should be included as an essential component to hydrologic studies

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