Stelian Ion

Mathematical modeling of the erosion processes in hydrographic basins

The erosion is a complex process determined by many physical, chemical, biological factors, affects the environment in a number of ways, and has a significant impact on the conservation and exploitation of natural resources, as well as on the quality of life. Due to its complexity, it is crucial to build a good erosion model in accordance with the envisaged main effects. The most determinant factors in the soil erosion - the process we focus in this article - are water dynamics, soil particle cohesion, and the cover plant presence. Our study focuses on the topography influence on water dynamics, the interactions plant cover - water flow, soil particle detachment - plant cover. We also analyze the model sensitivity to the variation of some soil parameters.

Water ow on vegetated hill. 1D shallow water equation type model

Abstract A mathematical model for the water ow on a hill covered by variable distributed vegetation is proposed in this article. The model takes into account the variation of the geometrical properties of the terrain surface, but it assumes that the surface exhibits large curvature radius. After describing some theoretical properties for this model, we introduce a simplified model and a well-balanced numerical approximation scheme for it. Some mathematical properties with physical relevance are discussed and finally, some numerical results are presented.

Modeling the water and sediment dynamics in vegetative filter strips

The primary goal of our study is to model the plant cover influence on water and soil erosion dynamics. The mathematical model consists in Saint-Venant equations coupled with the multiple particle class Hairsine-Rose soil erosion model. The numerical solutions are obtained from a finite volume scheme used to discretize the continuum model, where a second order fractional time step is applied for time integration. The numerical scheme is well-balanced and preserves the positivity of water depth and sediment density functions. The presence of the soil erosion equations do not imposes any restriction on the magnitude of the time step. Secondarily, we apply the general model to study the sediment transport in a vegetative buffer.