A stand age based sediment transport model

Our sediment transport model is developed using the hydrologic cycle as representative of the routing of water through a watershed. The elements of the hydrologic cycle described are rainfall, interception of rainfall, evaporation, infiltration, surface flow, groundwater flow, and stream flow. Surface flow is used as the transport mechanism for sediment. These elements of the hydrologic cycle are incorporated in a digital elevation model to predict the effects of forest stand age on the processes of erosion and sediment transport. A multiple regression model is used to generate soil depths throughout a watershed based on slope and elevation. A combination of continuous and discrete models is used to evaluate areas shielded from erosion by the forest canopy based on stand age. The production of large woody debris is modeled using an augmented Leslie matrix. A Markov chain predicts the production of organic debris and the volume contributed to sediment transport. The entire model is applicable in areas such as the small, steep watersheds of Northern California. It is capable of generating stand age distributions and occupancy areas for managed lands, as well as successional and old growth forests. The model can be used for evaluating habitat based on unit hydrographs, erosion, and sediment transport.