19 results

Diagnosis of the Accelerated Soil Erosion in São Paulo State (Brazil) by the Soil Lifetime Index Methodology

Grasiela de Oliveira Rodrigues Medeiros, Angelica Giarolla, Gilvan Sampaio, Mara de Andrade Marinho

12/Dec/2016

ABSTRACT: The soil is a key component of the Earth System, and is currently under high pressure, due to the increasing global demands for food, energy and fiber. Moreover, the management of agricultural systems is often inadequate and ignores the agricultural suitability of lands, and particularly the vulnerability of soils. This paper demonstrates the application of the concept of the Soil Lifetime Index (SLtI) for the entire state of São Paulo, at a spatial resolution of 30 m. The SLtI […]

Estimates of Annual Soil Loss Rates in the State of São Paulo, Brazil

Grasiela de Oliveira Rodrigues Medeiros, Angelica Giarolla, Gilvan Sampaio, Mara de Andrade Marinho

12/Dec/2016

ABSTRACT: Soil is a natural resource that has been affected by human pressures beyond its renewal capacity. For this reason, large agricultural areas that were productive have been abandoned due to soil degradation, mainly caused by the erosion process. The objective of this study was to apply the Universal Soil Loss Equation to generate more recent estimates of soil loss rates for the state of São Paulo using a database with information from medium resolution (30 m). The results showed […]

SELECTION OF SAMPLING DENSITY BASED ON DATA FROM AREAS ALREADY MAPPED FOR TRAINING DECISION TREE MODELS IN DIGITAL SOIL MAPPING

Tatiane Bagatini, Elvio Giasson, Rodrigo Teske

01/Jul/2015

In order to study sampling techniques useful for digital soil mapping (DSM), we evaluated the effect of changes in sampling density, based on data from areas already mapped by traditional methods, in regard to the accuracy of decision trees models for generating soil maps using DSM. In two watersheds in northwestern Rio Grande do Sul, Brazil, 1:50,000 scale conventional soils maps were used as reference maps. From the ASTER – GDEM Global Digital Elevation Model and the hydrographic network, maps […]

Surface mapping, organic matter and water stocks in peatlands of the Serra do Espinhaço meridional – Brazil

Márcio Luiz da Silva, Alexandre Christófaro Silva, Bárbara Pereira Christófaro Silva, Uidemar Morais Barral, Pablo Gomes e Souza Soares, Pablo Vidal-Torrado

01/Oct/2013

Peatlands are soil environments that store carbon and large amounts of water, due to their composition (90 % water), low hydraulic conductivity and a sponge-like behavior. It is estimated that peat bogs cover approximately 4.2 % of the Earth’s surface and stock 28.4 % of the soil carbon of the planet. Approximately 612 000 ha of peatlands have been mapped in Brazil, but the peat bogs in the Serra do Espinhaço Meridional (SdEM) were not included. The objective of this […]

Surface runoff in a watershed estimated by dynamic and distributed modeling

Samuel Beskow, Carlos Rogério de Mello, Gilberto Coelho, Antônio Marciano da Silva, Marcelo Ribeiro Viola

01/Feb/2009

Knowledge on the surface runoff in watersheds is very important for a good conservation of natural resources. However, surface runoff is a complex and dynamic process, especially in the context of spatial variability. An application of the Geographical Information System (GIS) tools in small grid cells is therefore adequate. This way, it is possible to consider the spatial behavior of variables associated to the origin of surface runoff. This study aimed to program the Hydrological Models SCS-CN (SCS-Curve Number) and […]

Bibliometrics, history and geography of Brazilian research on accelerated soil erosion

Alberto Giaroli de Oliveira Pereira Barretto, Marcelo Geraldo Estriga Barros, Gerd Sparovek

01/Dec/2008

Soil science history studies are rare and the Brazilian scientific community has not given substantial attention to this subject yet. The present study focused on the formation of research on accelerated soil erosion in the Brazil from a bibliometric perspective. A comprehensive database of published scientific papers was organized in a relational database and analyzed by SQL queries and GIS tools. These data were used to calculate quantitative indicators and spatial distribution patterns. Results indicate a recent development of research […]

Coverage and potential use of a soil profile database in Brazil

Marcelo Muniz Benedetti, Gerd Sparovek, Miguel Cooper, Nilton Curi, Amaury de Carvalho Filho

01/Dec/2008

Brazilian soil science is outstanding in tropical soil research, with a wealth of information on the soils of the country. However, this knowledge is not readily available. The aim of this study was to increase the range of a national soil profile database, based on soil surveys of wide extent. The soil taxonomy was updated based on the latest version of the Brazilian Soil Classification System. The updated database was also evaluated for coverage and potential for quantitative analyses. For […]

Environmental stratification in the Santana river watershed, south of Bahia, Brazil

Danusa Oliveira Campos, Cristina Carole Muggler, Elpidio Inácio Fernandes Filho, Mauricio Santana Moreau

01/Dec/2008

Many environmental problems in the watershed of the Santana River are caused by anthropogenic influence and the impact of economic activities. To attenuate these conflicts and to ensure the conservation and sustainability of this regionally extremely important area, the environment must be better understood. The aim of this study was an environmental stratification of the catchment of the River Rio Santana, in the South of Bahia, Brazil, based on the analysis of inter-relations between landscape components. Vegetation, geology and topography […]

Multiple logistic regression applied to soil survey in rio grande do sul state, Brazil

Samuel Ribeiro Figueiredo, Elvio Giasson, Carlos Gustavo Tornquist, Paulo César do Nascimento

01/Dec/2008

Logistic nominal regressions establish mathematical relations between continuous or discrete independent variables and discrete dependent variables. The prediction potential of the occurrence and distribution of soil classes in the region Ibirubá and Quinze de Novembro, RS, Brazil was evaluated. Using a digital elevation model (DEM) with 90 m resolution, were calculated several topographic characteristics (elevation, slope, and curvature) and hydrographic variables (distance to rivers, flow length, topographical wetness index, and stream power index). Multiple logistic regressions were established between the […]

Erosion study in the Ceveiro watershed (Piracicaba, SP). II – Interpreting soil loss tolerance using the Soil Useful Life Index methodology

Mara de Andrade Marinho Weill, Gerd Sparovek

01/Apr/2008

Accelerated soil erosion, a process basically induced by human activities contributes greatly to the degradation of arable land quality throughout the world, and is the main non-point source of surface water resource pollution. Considering the effective demand for developing indicators to evaluate the impact of soil erosion on soil quality in agriculture production systems, the objective of this study was to develop an index with a predictive value to be applied as a planning tool for interpreting soil loss tolerance […]

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