Submitted to: Water Erosion Prediction Project Documentation
Publication Type: Book / Chapter
Publication Acceptance Date: 8/10/1995
Publication Date: N/A
Technical Abstract: A continuous simulation erosion model, such as WEPP, requires a plant growth component in order to simulate the growth of plants and their impact on the hydrologic and erosion processes. This chapter describes the growth models used within the WEPP computer program to predict the development of cropland and rangeland plants. The purpose of the growth models is to predict temporal changes in plant and residue variables such as canopy cover, canopy height, root development, and biomass produced by the plants which is removed during a harvest operation or ends up as surface residue material. Cropland and rangeland plant growth are simulated in separate submodels of the WEPP model. The plant growth component provides information to the water balance component (Chapter 5) which allows estimation of daily water use by the plants and extraction of water from the soil layers. Canopy cover and height information are passed to the erosion component (Chapter 11) for use in estimation of interrill soil detachment. The amount of residue remaining after harvest, or residue created by leaf drop during senescence is sent to the residue decomposition and management component (Chapter 9) of the WEPP model. Crop yield predicted by the plant growth component is available as a model output, and the user may alter the biomass production and predicted crop yield through cautious adjustment of the plant-specific input parameters.