HR: 1340h
AN: H53D-0491    [Abstracts]
TI: Adding Multiple-Species Sediment Transport to the Integrated Hydrology Model (InHM)
AU: * Heppner, C S
EM: hepp@pangea.stanford.edu
AF: Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115 United States
AU: Ran, Q
EM: qhran@pangea.stanford.edu
AF: Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115 United States
AU: VanderKwaak, J E
EM: kwaak@pangea.stanford.edu
AF: 3DGeo Development Inc., 4633 Old Ironsides Drive, Suite 401, Santa Clara, CA 95054 United States
AU: Loague, K
EM: keith@pangea.stanford.edu
AF: Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115 United States
AB: A multiple species sediment transport algorithm has been added to the comprehensive hydrologic-response model known as the Integrated Hydrology Model (InHM). The new sediment transport algorithm simulates both rainsplash detachment and hydraulically-driven erosion, transport, and deposition of multiple sediment species. Rainsplash erosion is calculated as a function of rainfall intensity, particle size, surface water depth, the species' source fraction, and a coefficient related to groundcover percentage. The effect of particle size on rainsplash detachment is considered using an empirical size-dependent scaling factor. Hydraulic erosion/deposition is conceptualized as a kinetic transfer process. The sediment concentration in the flow evolves towards the equilibrium sediment transport capacity, calculated from transient flow properties, at a rate determined by surface and sediment properties. The hydraulic erosion component of the model allows for consideration of both cohesion and armoring of smaller species by larger immobile species. Two published datasets, each with multiple plot-scale erosion experiments, were used to test the sediment transport model. Rainsplash erosion data from 10 experimental plots with slopes ranging from 4 to 17 degrees and groundcovers ranging from 18 to 94 percent were used to test the rainsplash erosion component of the model, and to determine the relationship between the rainsplash coefficient and groundcover percentage. Data from two other experimental plots were used to test the multiple species hydraulic erosion component of the model. A split-sample approach was used with each dataset to calibrate and validate model parameters related to rainsplash erosion and surface erodibility. The performance of the sediment transport component of InHM, in both calibration and validation phases, was judged to be successful, based upon quantitative statistical criteria.
DE: 1815 Erosion
DE: 1826 Geomorphology: hillslope (1625)
DE: 1847 Modeling
DE: 1850 Overland flow
DE: 1862 Sediment transport (4558)
SC: Hydrology [H]
MN: Fall Meeting 2005