Published in Proceedings of the Symposium on Modelling Soil Erosion, Sediment Transport and Closely related Hydrological Processes, Vienna, July 1998, IAHSA Publ. no. 249
LUBOS MITAS
National Center for Supercomputing Applications, 405 N. Mathews Ave, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
HELENA MITASOVA
Geographic Modeling Systems Laboratory, Department of Geography, 220 Davenport Hall, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
Abstract New generation of simulation tools for modeling soil erosion, sediment transport and deposition by overland water flow in complex landscapes is presented. The simulations are based on the solution of bivariate continuity equations describing water and sediment transport over 3D terrain with variable climatic, soil and land cover conditions. Underlying equations are solved by advanced computational approaches based on stochastic projection techniques (Green's function Monte Carlo), providing the robustness and flexibility necessary for complex conditions and multiscale implementation. %with spatially variable accuracy/resolution. The processing, analysis and visualization of data and results are performed using an emerging multidimensional dynamic GIS technology. The possibilities of using the simulations as a tool for finding optimal land use patterns with minimized erosion risk are evaluated by comparing computer optimized land use scenario with the traditional landuse design.
Figures Figures 1, 2, 3.
Fig. 1 Terrain model with (a) traditional land use and linear erosion features, (b) simulated sediment flow, (c) erosion/deposition pattern for bare soil in the agricultural field and a 70 mm/hr rainfall excess.
Fig. 2 Terrain model with (a) observed depths of colluvial deposits, (b) simulated sediment flow, (c) erosion/deposition pattern for vegetative cover in the agricultural field and a 20 mm/hr rainfall excess.
Fig. 3 Terrain model with (a) computer designed land use, (b) simulated sediment flow, (c) erosion/deposition pattern for bare soil in the agricultural field and a 70 mm/hr rainfall excess.
Fig. 4 Illustration of the Green's function Monte Carlo method and its multi-scale implementation: (a)sediment flow rates estimated with 20,000 sampling points and (b) 2 million sampling points; (c) net erosion/deposition estimated with spatially variable resolution and accuracy.
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