Modeling the Complex Dynamics of Landscape Development: Applications for Land Management

Erosion on military lands limits Army training activities, and may cause environmental problems both at training sites and downstream. Thus, remedial soil and land conservation plans are vitally important to stabilize erosion and use the land more safely for Army activities while complying with environmental regulations and standards. The channel-hillslope integrated landscape development (CHILD) model is a dynamic, physicallybased, spatially distributed numerical framework for modeling soil erosion and landscape evolution, originally developed at MIT. Potential uses of CHILD include understanding the sensitivity of earth surface to changes in climate, land cover conditions and anthropogenic disturbances. In this paper, we present recent advances in the CHILD model with example numerical simulations. These are the effects of vegetation-erosion coupling on the short and long-term response of erosion rates and landscape topography, and modeling gully development by plunge-pool erosion at the gully head and widening by bank failures. CHILD simulations using a dynamic plant growth component show vegetation loss as an important factor accelerating erosion rates in decadal time scales. Over the long term, vegetation may change the dominant erosion process on the landscape, create episodicity in the sediment yields, and alter the visual appearance of landforms. Landscapes modeled using the new gully erosion module in CHILD produce landforms that compare well with the observed gullies in the Army training areas in Fort Carson and Pinon Canyon Maneuver Sites in Colorado. These results show potential applicability of the model for short and long-term land management purposes in the army lands.