HR: 1340h
AN: H13H-1405    [Abstracts]
TI: Modeling of forest roads impact on hydrological response
AU: * Rulli, M
EM: cristina.rulli@polimi.it
AF: Politecnico di Milano, Piazza L. Da Vinci, 32, Milan, I-20133 Italy
AU: Rosso, R
EM: renzo.rosso@polimi.it
AF: Politecnico di Milano, Piazza L. Da Vinci, 32, Milan, I-20133 Italy
AU: Moreni, S
EM: stefano.moreni@polimi.it
AF: Politecnico di Milano, Piazza L. Da Vinci, 32, Milan, I-20133 Italy
AU: Vigan•, M
EM: mattia.vigan•@polimi.it
AF: Politecnico di Milano, Piazza L. Da Vinci, 32, Milan, I-20133 Italy
AB: Forest roads can influence the hydrologic response of upland catchments, this including river geomorphology. The presence of compacted or paved roads increases overland flow because infiltration is reduced, and the natural flow pathways are modified due to interception by road cutslopes, that convey upslope runoff, this including both surface and part of subsurface flows. Roadways, and especially roadside ditches, route road-generated runoff to the stream network. This occurs at river crossing culverts or through gullies that can be incised below road drainage facilities that are not directly stream connected, depending on the characteristics of the receiving areas. This can lead to significant changes of the natural stream network and of storm hydrographs in small catchments. The capture and redirection of road-generated water fluxes involve also geomorphic effects as the formation of gullies, the migration of channel, the triggering of shallow landslide and debris-flows. To understand the impact of forest roads on hydrologic response one need to represent the geometric and topologic interconnectivity between forest roads, road drainage systems, watershed topography and stream network. This allows for the detection of each road segment sub basin, the computation of the relative contributing area, and the extraction of a drainage network that takes into account the presence of the road network. This approach is developed here to represent the distributed hydrologic fluxes and the resulting catchment response for an experimental basin where a number of roads built in the fifties are monitored. The study area is the H.J.Andrews Experimental Forest Watershed 3 (WS3), located in the Lookout Creek basin, Western Oregon Cascades. Hydrologic simulations show that one requires a detailed description of catchment topography to capture the effect of forest roads on water flows.
DE: 1625 Geomorphology and weathering (0790, 1824, 1825, 1826, 1886)
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1805 Computational hydrology
DE: 1850 Overland flow
SC: Hydrology [H]
MN: Fall Meeting 2005