Modelling Water Flow and Sediment Transport in Paddy Cascades in Northwest Vietnam
Rebecca Schaufelberger, Carsten Marohn, Georg Cadisch
University of Hohenheim, Inst. of Plant Production and Agroecology in the Tropics and Subtropics, Germany
Deforested mountainous watersheds in SE Asia under continuous maize cropping are prone to erosion. Erosion decreases soil fertility in the uplands and may have fertilising or silting effects on paddy fields in the lowlands. In paddies, ponding water and decreased flow velocity of run-off cause settling of suspended particles carrying nutrients and organic matter. LUCIA (Land Use Change Impact Assessment tool), a spatially explicit and dynamic model developed at the University of Hohenheim simulates water and nutrient cycles, plant growth and erosion on landscape-scale. However, paddy cascades, their specific topography and bunds and their influence on deposition are not part of the model up to now. The aim of this study was a) to develop a standalone model simulating water flow and sediment transport in paddy cascades that can be integrated into LUCIA, b) a first plausibility validation of the new model based on field data from Northern Vietnam.
Keywords: Hydrology, landscape modelling, paddy model
Contact Address: Rebecca Schaufelberger, University of Hohenheim, Inst. of Plant Production and Agroecology in the Tropics and Subtropics, 70593 Stuttgart, Germany, e-mail: r.schaufelbergeruni-hohenheim.de