Rev. Bras. Ciênc. Solo.2025;49:e0240108.
Modeling the effect of terracing on runoff control in a rural catchment in southern Brazil
Larissa Werle 
, Jean Paolo Gomes Minella , Gustavo Henrique Merten , Douglas Rodrigo Kaiser , Alexandre Schlesner , Alice Prates Bisso Dambroz , Blayon Eduardo Hammes , Felipe Bernardi
16/Jun/2025
DOI: 10.36783/18069657rbcs20240108
Graphical Abstract
Highlights
Hydrological monitoring of experimental catchments combined with modeling of surface runoff at the event scale contributes to the planning and management of rural catchments.
This study demonstrate the effectiveness of conservation practices in croplands and the importance of their contribution to reduce surface runoff.
The presence of retention broad-based terraces contributed to reducing total runoff volume and to attenuating peak flow in the main fluvial channel of the catchment.
ABSTRACT
Extreme weather events, such as heavy rains and droughts, necessitate the rapid adaptation of production systems to prevent the degradation of natural resources and to maximize production potential. Defining adaptive practices requires an in-depth understanding of the factors that control the formation and propagation of surface runoff and the identification of specific practices tailored to each location. No-till system, coupled with complementary storm runoff management practices, is effective in controlling surface runoff and related processes. However, the planning of the capacity and allocation of these practices, considering the specific interaction of controlling factors in each catchment, is not well understood. Planning conservation practices at the catchment scale through hydrological modeling and monitoring presents an efficient alternative, as it integrates the controlling factors that govern storm runoff dynamics. This study sought to understand the influence of different levels of conservation intervention (surface runoff control practices) on the hydrological behavior of the experimental catchment of the Guarda Mor River (southern Brazil). The method relied on monitoring hydrological variables (rainfall and streamflow) at the catchment outlet and on the physiographic characterization of the catchment, including the spatial variability of soils, topography, land use, and soil management. After analyzing a significant set of rainfall-runoff events, the generation and propagation of surface runoff were modeled (calibration and validation) using the Limburg Soil Erosion Model. The impacts of two conservation intervention scenarios were tested: buffer strips plus well-managed no-till (Scenario 1) and retention broad-based terraces plus well-managed no-till (Scenario 2). Conservation practices were assessed by evaluating the following hydrologic parameters: surface runoff volume, peak flow, and time to peak. Simulation results indicate that both intervention levels effectively controlled surface runoff. Scenario 1 resulted in an average reduction in surface runoff volume and peak flow attenuation of 7 and 6 %, respectively. Scenario 2 achieved an average decrease in surface runoff volume and peak flow attenuation of 30 and 28 %, respectively. These results quantitatively demonstrate the positive impact of soil and water conservation practices on the drainage network. The impacts of the two scenarios in the time to peak were not significantly altered, except for one event. Catchment-scale conservation planning is an efficient and promising strategy for improving conservation agriculture, underscoring its importance in water resource management and promoting environmental services.
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