Overland flow connectivity : theory and application at the interrill scale
(2010)
Files
PhD_MAntoine.pdf
Open Access - Adobe PDF
- 4.79 MB
Details
- Authors
- Supervisors
- Abstract
- (en) To predict the hydrological response of a hillslope to a rainfall event, the spatial configuration of soil roughness needs to be taken into account. Quantitative expressions of hydrological connectivity based on topography may improve the prediction of overland flow propagation, especially if the connectivity concept is applied at the subgrid scale of current hillslope models, which corresponds to the interrill scale. Our first objective was to measure the effect of micro-topography on overland flow. Some of the water is stored in depressions (depression storage) and some is temporarily stored in the flowing water layer (surface detention). To measure those storages, we used a new molding technique that reproduced realistic but waterproof soil surfaces, which were subjected to artificial runoff. The evolution of both storages following rainfall was related to the cumulative rainfall erosivity value. Our second objective was to find runoff-relevant connectivity properties of micro-topography. Based on numerical runoff experiments, we found that, among a number of existing structural connectivity indices and a proposed new functional connectivity index (namely the Relative Surface Connection function), the RSC function was the most robust and directly linkable to the runoff dynamics. Our last objective was to introduce the connectivity properties captured by the RSC function at the subgrid (interrill) scale in distributed hydrological models. A corrective procedure was proposed to combine both surface detention and depression storage dynamics. It allows mimicking the hydraulic behavior of small plots where the effect of the micro-topography is characterized by few (1 or 2) effective parameters implementable in hillslope models.
- Affiliations
Citations
Antoine, M. (2010). Overland flow connectivity : theory and application at the interrill scale. https://hdl.handle.net/2078.5/131011