Fluvial erosion in a catchment cultivated with no-tillage at the edge of the southern Brazilian plateau.

Autor: Bernardi F; Graduate Program in Soil Science, Federal University of Santa Maria, Santa Maria, Brazil., Minella JPG; Department of Soils, Federal University of Santa Maria, Santa Maria, Brazil. jean.minella@ufsm.br., Dambroz APB; Graduate Program in Soil Science, Federal University of Santa Maria, Santa Maria, Brazil., Schlesner A; Graduate Program in Soil Science, Federal University of Santa Maria, Santa Maria, Brazil., Merten GH; Department of Civil Engineering, University of Minnesota-Duluth, Duluth, USA., Mao L; Department of Geography, University of Lincon, Lincon, England., Evrard O; Laboratoire des Sciences du Climat et de l'Environnement, Unité Mixte de Recherche (CEA-CNRS-UVSQ), Université Paris-Saclay, Saclay, France., Piccilli DGA; Department of Sanitary and Environmental Engineering, Federal University of Santa Maria, Santa Maria, Brazil., Dalmolin RSD; Department of Soils, Federal University of Santa Maria, Santa Maria, Brazil., de Araújo Pedron F; Department of Soils, Federal University of Santa Maria, Santa Maria, Brazil.
Jazyk: angličtina
Zdroj: Environmental monitoring and assessment [Environ Monit Assess] 2024 Dec 03; Vol. 197 (1), pp. 9. Date of Electronic Publication: 2024 Dec 03.
DOI: 10.1007/s10661-024-13440-1
Abstrakt: The dynamics of fluvial erosion responds to soil erosion and surface runoff on hillslopes due to land use and environmental fragility, conditioned by the soil, geology, relief, and rainfall rate. Despite the increasing problems associated with fluvial erosion in Brazil, little information is available on bedload transport in headwater catchments under intense agricultural activity. Therefore, this study sought to characterize the fluvial erosion processes and bedload dynamics in an experimental catchment in southern Brazil located at the edge of the Brazilian Meridional plateau, which is representative of a large area of high environmental fragility and intense agricultural activity in Southern Brazil. The Guarda Mor River drains a headwater catchment (18.5 km 2 ) with undulating and hilly terrain with fragile soils and intense agricultural activity controlling fine and coarse sediment supply downstream. During 11 major rainfall-runoff events, monitoring was conducted to measure streamflow, bedload transport rates, sediment size, and hydraulic parameters, such as Manning's n values and viscous layer thicknesses. A rating curve was established based on 40 streamflow and bedload discharge measurements taken at different water levels and stages along the hydrograph. In addition, a river portion (gravel bed) was characterized as well as the granulometric characteristics of its surface and subsurface layers. The results showed that the transport pattern is influenced by factors other than hydraulic parameters alone, including the interdependence between successive events, armoring effects, and hysteresis. These factors are strongly related to the surface runoff and erosion observed on the hillslopes, which define the streamflow energy and the supply of sand fraction, respectively. A discussion is held on the bedload transport dynamics under non-equilibrium conditions in the modeling of fluvial erosion processes.
Competing Interests: Declarations. Ethical approval: Not applicable.
(© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)
Databáze: MEDLINE
Externí odkaz: