Sediment yield in Paraopeba River Basin – MG, Brazil

Abstract

Sediment delivery rate (SDR) is traditionally defined as a fraction of upland gross erosion that is transported through the outlet of a given basin, thus representing an index of the sediment transport efficiency. The objective of this study was to evaluate a model-based approach for SDR determination in the Paraopeba River Basin (PRB), located at the central region of Minas Gerais State, Southeastern Brazil. The empirical model known as RUSLE, which stands for Revised Universal Loss Equation, was used embedded in a geographical information system (GIS) to estimate the soil erosion potential. Based on a monitoring network, considering the period between 1997 and 2008, the sediment transport was determined in five sub-basins of the PRB. The average water erosion for PRB was 2.7 ton ha 21 yr 21 , while the sediment transport varied from 0.25 to 1.63 ton ha 21 yr 21 . Considering the area and the slope as the independent variables, three empirical models were applied for estimating SDR. The results showed adequate fit for the proposed model, resulting in improvements for SDR estimates in PRB. On evaluating only sub-basins, the observed average SDR was 0.38, while the corresponding estimated value was 0.37. It was found that the three traditional equations did not generate acceptable results and this can be explained by the overestimation of SDR values for PRB.

To What Extent Can a Sediment Yield Model Be Trusted? A Case Study from the Passaúna Catchment, Brazil

“…The most erodible soils, dominated by Distrofic Latossol (Oxisol), are located in the northern part of the catchment, according to the soil map provided by the Brazilian Agricultural Corporation (EMBRAPA) [67]. The results are also aligned with further literature values in that geographic area, which also assessed that the K Factor for Latossol (Oxisol) is in the range of 0.019-0.026 t ha h ha −1 MJ −1 mm −1 [68][69][70][71]. The western part of the catchment, which is also dominated by Oxisol, showed low soil erodibility with values reaching up to 0.013 t ha h ha −1 MJ −1 mm −1 .…”

“…further literature values in that geographic area, which also assessed that the K Factor for Latossol (Oxisol) is in the range of 0.019-0.026 t ha h ha −1 MJ −1 mm −1 [68][69][70][71]. The western part of the catchment, which is also dominated by Oxisol, showed low soil erodibility with values reaching up to 0.013 t ha h ha −1 MJ −1 mm −1 .…”

Water erosion vulnerability and sediment delivery rate in upper Iguaçu river basin – Paraná

“…This spatial variability has been observed in other studies, like that of De Vente et al (2008), who obtained a SDR that varied from 0.03 to 55% for in 61 subbasins in Spain. Likewise, Van Rompaey, Krasa and Dostal (2007) Water erosion vulnerability and sediment delivery rate in upper Iguaçu river basin -Paraná hand, Beskow et al (2009), examining the Rio Grande River Basin in the state of Minas Gerais, found an average value of 1.62% for a drainage area greater than 6,000 km 2 , whereas Durães, Mello and Beskow (2016), upon inspection of the Paraopeba River Basin's SDR, discovered values varying from 8.6% to 66% for an area of 8,659 km 2 . In accordance with Brown et al (2005), the impacts of alterations in the use of soil in drainage basins concerning superficial runoff can, in general, be evaluated in terms of maximum and minimum outflow.…”

“…As monitoring soil management and conservational practices are difficult to achieve via satellite imaging, since they represent a small portion of the basin, this variable was considered to be 1. It must be highlighted that this same thought was used in various works, such as those of Pradhan et al (2012), Vemu andPinnamaneni (2011), Silva, Montenegro andSantos (2012), Oliveira et al (2014) and Durães, Mello and Beskow (2016). The values of C used in this study were obtained from the literature presented in Table 4.…”

USLE K-Factor Method Selection for a Tropical Catchment

“…The SDR spatial distribution can be observed in Figure 6B and it is mainly determined by the land topography. However, in some cases, the spatial heterogeneity of the SDR is not represented in the sediment yield modelling in the context of watersheds, and it is computed as a single ratio to multiply by the average gross erosion of the area [7,56]. We found a SDR value of approximately 5% in the Córrego Água Azul catchment.…”