HR: 1330h
AN: H42C-1101    [PDF]
TI: Impacts of Groundwater Dynamics on Landscape Evolution
AU: * Huang, X
EM: xjhuang@psu.edu
AF: Pennsylvania State University, 212B Sackett Building, University Park, PA 16802 United States
AU: Niemann, J
EM: jniemann@engr.colostate.edu
AF: Colorado State University, A226 Engineering Building, Fort Collins, CO 80523 United States
AB: Many numerical models have been developed recently to describe the evolution of landscapes under tectonic, hillslope, and fluvial processes. In most of these models, hydrological processes such as precipitation, infiltration, and groundwater flow are greatly simplified or neglected to facilitate efficient computation. These hydrologic processes ultimately determine the movement and distribution of water, which control soil erosion and sediment transport. Groundwater is one of the most important hydrologic components because it influences soil moisture conditions and the partitioning of precipitation between surface runoff and infiltration. In addition, when groundwater returns to the land surface, it can produce saturated seepage faces, which are often associated with amphitheatre-like channel sources. Groundwater has been considered in several recent landscape evolution models by introducing an effective precipitation rate that equals the difference between the precipitation rate and an infiltration rate. In these models, the infiltrating water is simply removed from the simulation, so groundwater discharge is not possible. This paper presents a new method to consider groundwater in models of landscape evolution. The two-dimensional Dupuit equation is used to describe the groundwater flow in a homogeneous isotropic unconfined aquifer. The aquifer can represent the regolith and the impervious layer under the aquifer can be an irregular bedrock surface. The groundwater table is tracked by simulating this equation, and the locations and amounts of groundwater discharge are calculated through a comparison of the groundwater table and the land surface. The results from this model are compared with those from traditional models. Under certain circumstances, groundwater has an important impact on the slope-area relationship and other measures of basin morphology.
DE: 1800 HYDROLOGY
DE: 1815 Erosion and sedimentation
DE: 1824 Geomorphology (1625)
DE: 1829 Groundwater hydrology
DE: 1854 Precipitation (3354)
SC: Hydrology [H]
MN: 2003 Fall Meeting