Consulta: subjectFacets:"Digital elevation model"
Registros recuperados: 9
Data/hora: 09/06/2024 13:55:59

QUALITY OF A DIGITAL TERRAIN MODEL FOR SANTA CATARINA STATE
Provedor de dados: 70
Autores: Caten,Alexandre Ten; Dalmolin,Ricardo S. D.; Boeing,Evandro L.; Vitalis,Fernando A.; Silva,Walquíria C. Da.
ABSTRACT: Relief characterization using a digital terrain model (DTM) is widely applied in erosion, soil and vegetation modeling. However, factors, such as acquisition technology and the spatial resolution of the digital model, affect modeling results. The aim of this study was to characterize noises in a DTM of the entire state of Santa Catarina recently made available through the state's Sustainable Economic Development Secretary and to evaluate different methods of interpolation and smoothing of the original 1 m resolution to a new digital model with a spatial resolution of 15 m. Using the SAGA GIS program, spurious data that appeared as peaks and sinks were removed from the digital model. Of five processing procedures, the following three were used for...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Digital elevation model; Geomorphometry; Slope; Digital soil mapping; Aerial imagery.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000601261

Prediction of soil orders with high spatial resolution: response of different classifiers to sampling density
Provedor de dados: 86
Autores: Sarmento,Eliana Casco; Giasson,Elvio; Weber,Eliseu; Flores,Carlos Alberto; Hasenack,Heinrich.
The objective of this work was to evaluate sampling density on the prediction accuracy of soil orders, with high spatial resolution, in a viticultural zone of Serra Gaúcha, Southern Brazil. A digital elevation model (DEM), a cartographic base, a conventional soil map, and the Idrisi software were used. Seven predictor variables were calculated and read along with soil classes in randomly distributed points, with sampling densities of 0.5, 1, 1.5, 2, and 4 points per hectare. Data were used to train a decision tree (Gini) and three artificial neural networks: adaptive resonance theory, fuzzy ARTMap; self‑organizing map, SOM; and multi‑layer perceptron, MLP. Estimated maps were compared with the conventional soil map to calculate omission and commission...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Appellation of origin; Decision tree; Digital elevation model; Geographic information systems; Neural network; Soil mapping.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000900025

Computer-assisted cartography using topographic properties: precision and accuracy of local soil maps in central Mexico
Provedor de dados: 90
Autores: Cruz-Cárdenas,Gustavo; Ortiz-Solorio,Carlos Alberto; Ojeda-Trejo,Enrique; Martínez-Montoya,Juan Felipe; Sotelo-Ruiz,Erasto Domingo; Licona-Vargas,Atenogenes Leobardo.
Map units directly related to properties of soil-landscape are generated by local soil classes. Therefore to take into consideration the knowledge of farmers is essential to automate the procedure. The aim of this study was to map local soil classes by computer-assisted cartography (CAC), using several combinations of topographic properties produced by GIS (digital elevation model, aspect, slope, and profile curvature). A decision tree was used to find the number of topographic properties required for digital cartography of the local soil classes. The maps produced were evaluated based on the attributes of map quality defined as precision and accuracy of the CAC-based maps. The evaluation was carried out in Central Mexico using three maps of local soil...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Decision tree; Digital elevation model; Map quality.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000300003

Assessing Water Erosion Processes in Degraded Area Using Unmanned Aerial Vehicle Imagery
Provedor de dados: 90
Autores: Siqueira Junior,Paulo; Silva,Marx Leandro Naves; Cândido,Bernardo Moreira; Avalos,Fabio Arnaldo Pomar; Batista,Pedro Velloso Gomes; Curi,Nilton; Lima,Wellington de; Quinton,John Norman.
ABSTRACT The use of Unmanned Aerial Vehicles (UAVs) and Structure from Motion (SfM) techniques can contribute to increase the accessibility, accuracy, and resolution of Digital Elevation Models (DEMs) used for soil erosion monitoring. This study aimed to evaluate the use of four DEMs obtained over a year to monitor erosion processes in an erosion-degraded area, with occurrence of rill and gully erosions, and its correlation with accumulated rainfall during the studied period. The DEMs of Geomorphic Change Detection (GCD) of horizontal and vertical resolutions of 0.10 and 0.06 m were obtained. It was possible to detect events of erosion and deposition volumes of the order of 2 m3, with a volumetric error of ∼50 %, in rills and gullies in the initial stage...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gully; UAV; Digital elevation model; Structure-from-motion.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100525

The combined use of reflectance, emissivity and elevation Aster/Terra data for tropical soil studies
Provedor de dados: 90
Autores: Breunig,Fábio Marcelo; Galvão,Lênio Soares; Formaggio,Antonio Roberto; Couto,Eduardo Guimarães.
Reflectance, emissivity and elevation data of the sensor ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer)/Terra were used to characterize soil composition variations according to the toposequence position. Normalized data of SWIR (shortwave infrared) reflectance and TIR (thermal infrared) emissivity, coupled to a soil-fraction image from a spectral mixture model, were evaluated to separate bare soils from nonphotosynthetic vegetation. Regression relationships of some soil properties with reflectance and emissivity data were then applied on the exposed soil pixels. The resulting estimated values were plotted on the ASTER-derived digital elevation model. Results showed that the SWIR bands 5 and 6 and the TIR bands 10 and 14 measured the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Digital elevation model; Soil constituents; Remote sensing; Topography.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000600027

Methodology for the spatialisation of a reference evapotranspiration from SRTM data
Provedor de dados: 124
Autores: Oliveira,Joaquim Branco de; Arraes,Francisco Dirceu Duarte; Viana,Paula Carneiro.
The aim of this work was to develop a methodology for the spatialisation of mean monthly reference evapotranspiration for the State of Ceará, using the Hargreaves and Samani equation, from estimated air-temperature data based on digital elevation models. The study area is located in northeastern Brazil, between the latitudes 2.5º and 8º South and longitudes 37º and 42º West. The data used in the study are from the network of meteorological stations of the National Institute of Meteorology. The equation proposed by Hargreaves and Samani was used to estimate ET, being spatialised in the form of maps using the Idrisi Andes© software for the manipulation of digital data of latitude, longitude and altitude in order to obtain the variables of the equation. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Digital elevation model; Hargreaves and Samani; Air temperature; GIS.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902013000300005

Digital soilscape mapping of tropical hillslope areas by neural networks
Provedor de dados: 63
Autores: CarvalhoJunior,Waldir de; Chagas,César da Silva; FernandesFilho,Elpídio Inácio; Vieira,Carlos Antonio Oliveira; Schaefer,Carlos Ernesto Gonçalves; Bhering,Silvio Barge; Francelino,Marcio Rocha.
Geomorphometric variables are applied in digital soil mapping because of their strong correlation with the disposition and distribution of pedological components of the landscapes. In this research, the relationship between environmental components of tropical hillslope areas in the Rio de Janeiro State, Brazil, artificial neural networks (ANN), and maximum likelihood algorithm (MaxLike) were evaluated with the aid of geoprocessing techniques. ANN and MaxLike were applied to soilscape mapping and the results were compared to the original map. The ANN architectures with seven and five neurons in the hidden layer produced the best classifications when using samples obtained systematically. When random samples were applied, the best neural net architectures...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Geomorphometric attribute; Digital soil mapping; Digital elevation model.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162011000600014

Microbiological Indicators of Soil Quality Under Native Forests are Influenced by Topographic Factors
Provedor de dados: 42
Autores: TEIXEIRA,ANITA F.S.; SILVA,JACQUELINE S.; VILELA,LAÍZE A.F.; COSTA,PATRÍCIA F.; COSTA,ELAINE M. DA; GUIMARÃES,AMANDA A.; SANTOS,JESSÉ V. DOS; SILVA,SÉRGIO H.G.; CARNEIRO,MARCO AURÉLIO C.; MOREIRA,FATIMA M.S.
Abstract: Several microbiological indicators of soil quality present high sensitivity, but little is known about the influence of topographic factors on them. This work aimed to evaluate variability of biological indicators of soil quality across a hillslope under native forest and the influence of topographic factors on them. Four positions on a hillslope were evaluated. Activity of the enzymes β-glucosidase, acid phosphatase, urease and fluorescein diacetate (FDA) hydrolysis were determined, as well as basal and substrate-induced respiration, and density of microorganisms: total bacteria, total fungi, actinobacteria, phosphate solubilizers, ammonifiers, native rhizobia, free-living N2-fixing bacteria, spores of arbuscular mycorrhizal fungi and percentage...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biological indicators; Digital elevation model; Enzymes; Microbial activity; Random forest.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000700866

Simple Air Temperature Estimation Method from MODIS Satellite Images on a Regional Scale
Provedor de dados: 117
Autores: Flores P,Fabiola; Lillo S,Mario.
Agricultural studies on a regional scale about water balance and evapotranspiration estimation, among others, require estimating air temperature (Ta) spatial variation since the generally low density of weather stations does not allow obtaining such data for a specific area. The aim of this study was to estimate air temperature through atmospheric profiles provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on a regional level. One of the present-day methodologies estimates Ta through vertical temperature profiles, which is why modifications to this methodology were proposed for zoning, surface elevation, and pressure/altitude ratios. By applying this new methodology, better Ta estimates were obtained by replacing the MODIS sensor...
Tipo: Journal article
Palavras-chave: MODIS; Atmospheric profile; Digital elevation model.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000300011