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43 results

Soil Erodibility under Natural Rainfall Conditions as the K Factor of the Universal Soil Loss Equation and Application of the Nomograph for a Subtropical Ultisol

Elemar Antonino Cassol, Tiago Stumpf da Silva, Flávio Luiz Foletto Eltz, Renato Levien

03/May/2018

ABSTRACT: Erodibility represents the intrinsic susceptibility of the soil to the erosion process, represented by the K factor in the Universal Soil Loss Equation (USLE). In Brazil, there are few field experiments determined with a series larger than ten years of data, which are the most reliable for quantifying the K factor. The aim of this study was to determine the K factor of the USLE by the direct method, relating soil losses determined in the field under standard conditions […]

Multivariate Analysis of Erosivity Indices and Rainfall Physical Characteristics Associated with Rainfall Patterns in Rio de Janeiro

Roriz Luciano Machado, Daniel Fonseca de Carvalho, Janaina Ribeiro Costa Rouws, Wilk Sampaio de Almeida, Paulo Tarso Sanches de Oliveira

21/Nov/2017

ABSTRACT The identification of areas with greater erosive potential is important for planning soil and water conservation. The objective of this study was to evaluate the physical characteristics of rainfall events in the state of Rio de Janeiro, Brazil, and their interactions with rainfall patterns through multivariate statistical analysis. Rainfall depth, kinetic energy, 30-min intensity (I30), duration of rainfall events, and the erosivity indices KE >10, KE >25, and EI30 in 36 locations (stations) were subjected to principal component analysis […]

NITROGEN LOSS BY EROSION FROM MECHANICALLY TILLED AND UNTILLED SOIL UNDER SUCCESSIVE SIMULATED RAINFALLS

Julieta Bramorski, Paulo Cesar Ocheuze Trivelin, Silvio Crestana

01/Jul/2015

The description of the fate of fertilizer-derived nitrogen (N) in agricultural systems is an essential tool to enhance management practices that maximize nutrient use by crops and minimize losses. Soil erosion causes loss of nutrients such as N, causing negative effects on surface and ground water quality, aside from losses in agricultural productivity by soil depletion. Studies correlating the percentage of fertilizer-derived N (FDN) with soil erosion rates and the factors involved in this process are scarce. The losses of […]

Identifying sources of sediment production in a hillside catchment area

Pablo Miguel, Ricardo Simão Diniz Dalmolin, Fabrício de Araújo Pedron, Jean Michel Moura-Bueno, Tales Tiecher

01/Apr/2014

Land use outside of its agricultural suitability is the main cause of degradation of natural resources due to anthropogenic activities. Agricultural activities are among those that most disturb the environment, exposing the soil to the action of water erosion and accelerating the transfer of sediments into bodies of water. In recent years, the fingerprinting method for identifying sources of sediment has been successfully used throughout the world; however, such studies in Brazil are still incipient. This study aims to estimate […]

The contribution of sediment sources in a rural catchment under no-tillage

Tales Tiecher, Jean Paolo Gomes Minella, Pablo Miguel, Jimmy Walter Rasche Alvarez, André Pellegrini, Viviane Capoane, [...]

01/Apr/2014

Knowledge of the main diffuse sources of sediment production can enhance efficiency in use of public resources invested in management strategies that seek to mitigate sediment transfer to waterways from catchment areas. The aim of the present study was to evaluate the sediment sources in a rural catchment with predominance of annual crops under a no-tillage system and with intense and inappropriate exploitation of natural resources (soil and water) by quantifying the relative contribution of roads and croplands in the […]

Sensitivity analysis of the parameters of the SWAT model and simulation of the hydrosedimentological processes in a watershed in the northeastern region of Brazil

Ricardo de Aragão, Marcus Aurélio Soares Cruz, Julio Roberto Araujo de Amorim, Luciana Coêlho Mendonça, Eduardo Eneas de Figueiredo, Vajapeyam S. Srinivasan

01/Aug/2013

Erosion has been recognized as the main cause of soil degradation and is accelerated by human intervention in watersheds, causing losses to the agricultural sector and damaging the environment. To estimate the impacts caused by land use or climate changes on hydrosedimentological processes, physically-based distributed models have been shown to be quite effective. In this study, the SWAT model was calibrated and validated for two subwatersheds of the Japaratuba Mirim river watershed, one located upstream of the Fazenda Pão de […]

Erodibility, soil cover and management and conservation practices in rainfed ultisol

Eliete Nazaré Eduardo, Daniel Fonseca de Carvalho, Roriz Luciano Machado, Paula Fernanda Chaves Soares, Wilk Sampaio de Almeida

01/Jun/2013

The soil loss prediction models have become important tools for conservation planning, being fundamental the local estimation of the parameters that influence the erosion processes. The objective of this work was to determine the soil erodibility (K factor), soil cover and management factor (C factor) and conservation practice factor (P factor) of the Universal Soil Erosion Equation (USLE), in an Ultisol. Soil losses (SL) were measured in Wischmeier standard-plots from 2006 to 2011, with the respective erosivity index (EI30). Soil […]

Soil losses from typic cambisols and red latosol as related to three erosive rainfall patterns

Regimeire Freitas Aquino, Marx Leandro Naves Silva, Diego Antonio França de Freitas, Nilton Curi, Junior Cesar Avanzi

01/Feb/2013

Rainfall erosivity is one of the main factors related to water erosion in the tropics. This work focused on relating soil loss from a typic dystrophic Tb Haplic Cambisol (CXbd) and a typic dystrophic Red Latosol (LVdf) to different patterns of natural erosive rainfall. The experimental plots of approximately 26 m2 (3 x 8.67 m) consisted of a CXbd area with a 0.15 m m-1 slope and a LVdf area with 0.12 m m-1 slope, both delimited by galvanized plates. […]

Rainfall simulator thrust type with hydraulically moved arms: fabrication and calibration

Ildegardis Bertol, Camilo Bertol, Fabrício Tondello Barbosa

01/Dec/2012

The use of rain simulators is fundamental to study rainfall erosion. They are used to monitor the experimental conditions, particularly the rain characteristics and to understand the soil erosion process better. Several types of rainfall simulators have been developed since 1930 around the world. Currently, the Swanson model is the most commonly used. However, a small number of these simulators is fully operational in Brazil, due to the high degree of wear and difficulties of maintenance. The purpose of this […]

Use of the swat model for hydro-sedimentologic simulation in a small rural watershed

Talita Uzeika, Gustavo H Merten, Jean P.G Minella, Michele Moro

01/Apr/2012

Mathematical models have great potential to support land use planning, with the goal of improving water and land quality. Before using a model, however, the model must demonstrate that it can correctly simulate the hydrological and erosive processes of a given site. The SWAT model (Soil and Water Assessment Tool) was developed in the United States to evaluate the effects of conservation agriculture on hydrological processes and water quality at the watershed scale. This model was initially proposed for use […]

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