Hydrology and Sedimentology of Dynamic Rill Networks. Volume 1. Erosion Model forDynamic Rill Networks. Part A. Introduction and Overview. Part B. Erosion Model Development

摘要

Presented is the development of a dynamic erosion model based on fundamentalconcepts of hydrology, sedimentology and probability. The model predicts erosion rates for varying surface conditions and will ultimately be used to evaluate new and existing tillage systems without requiring extensive apriori field measurements. In addition, the dynamic erosion model can be used to assess the impact of rill density, surface roughness, channel network development and numerous other erosion sub-processes on sediment yield. The dynamic erosion model contains a deterministic runoff and erosion component applied to a stochastically generated random surface. The random surface is generated using a defined random roughness and correlation length for a specified covariance function. The resulting flow networks are defined with a digital elevation model applied to the generated surface. The erosion component models interrill erosion delivered to the flow network, and rill erosion based on shear excess principles. In addition, rill geometry for a rectangular cross-section is based on flow conditions, soil properties and surface geometry.