Contribution of intercepted subsurface flow to road runoff and sediment transport in a logging‐disturbed tropical catchment |
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| Authors: | J N Negishi R C Sidle A D Ziegler S Noguchi N Abdul Rahim |
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| Institution: | 1. Department of Geography, National University of Singapore, Singapore;2. Geohazards Division, Disaster Prevention Research Institute, Kyoto University, Japan;3. Geography Department, University of Hawaii, USA;4. Forestry and Forest Products Research Institute, Tohoku Branch, Japan;5. Forest Research Institute Malaysia, Malaysia |
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| Abstract: | Hydrological and sediment fluxes were monitored for a 1 yr period in a tropical headwater catchment where a 3 yr old logging road caused substantial Hortonian overland flow (HOF) and intercepted subsurface flow (ISSF). On a 51·5 m road section, ISSF became an increasingly important component of total road runoff, up to more than 90% for large storms. The proportion of ISSF contributed by road cuts along more or less planar slopes compared with ISSF from a zero‐order basin (convergent slopes) truncated by the road declined with increasing rainfall. During the monitored storms that generated ISSF along the road, on average, 28% of sediment export and 79% of runoff from the road section were directly attributable to ISSF. Estimates of total sediment export from the road surface (170 t ha?1 yr?1) and suspended sediment export from the logging‐disturbed catchment (4 t ha?1 yr?1) were exceptionally high despite 3 yr of recovery. ISSF caused not only additional road‐generated sediment export, but also exacerbated HOF‐driven erosion by creating a poor foundation for vegetation recovery on the road surface. Copyright © 2007 John Wiley & Sons, Ltd. |
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| Keywords: | cutbank seepage logging impacts hydrogeomorphic controls sediment yield tropics |
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