Dissertação apresentada como um dos requisitos à obtenção do Grau de Mestre em SensoriamentoRemot... more Dissertação apresentada como um dos requisitos à obtenção do Grau de Mestre em SensoriamentoRemoto Porto Alegre (RS), Brasil. Dezembro de 1995 AGRADECIMENTOS Ao professorMoacir A. Berlato,por ter me aceito como seu orientado no Curso de pós-graduação em SensoriamentoRemoto; Ao professor Vitor Haertel, por ter aceitado a co-orientação e pelo apoio no sentido de concretizar o intercâmbio do CEPSRM com outras entidades; Ao professorAtos FreitasGrawunder,coordenador do Curso de Pós-graduação em Economia Rural da UFRGS, pelo auxílio na estruturação da presente dissertação; À Cooperativa Tritícola Mista Alto Jacuí Ltda, pelo apoio de campo e atenção dedicada à execução do trabalho, muitas vezes deslocando técnicos importantes de suas funções para o levantamento das informações necessárias; Ao professorAlfonsoRissoque, atravésda troca de idéiase sugestões, contribuiu na montagem do projeto; Ao Engenheiro Agrônomo Eduardo Juan Ruiz Posse, professor da Universidad Nacionalde Córdoba,RepúblicaArgentina,pela amizade e parceria na realização de tarefas e sugestões em assuntos relacionados à execução do trabalho; Aos colegas do curso de mestrado que compartilharam dificuldades e confraternizaram em vários eventos, tornando mais agradável o período do curso; Aos funcionáriostécnicos e administrativosdo CEPSRM que, de uma ou outra forma, prestaram sua colaboração à solução dos problemas surgidos durante o curso e contribuíram para a conclusão deste estudo. II USO DE SISTEMAS DE INFORMAÇÃO GEOGRÁFICA COMO SUBSÍDIO SINOPSE Os Sistemas de Informação Geográfica vêm sendo cada vez mais utilizados em estudos envolvendo o planejamento e gerenciamento de recursos e meio-ambiente. A agricultura é uma das atividades humanas mais intimamente relacionadas com o meioambiente. Este trabalho investiga o emprego desses sistemas para integrar diferentes informações relacionadas à produção agrícola e obter respostas que subsidiem o planejamentoem regiõesagrícolas.A área estudada é uma localidade do município de Nãome-Toque, situado no planalto médio do Rio Grande do Sul, entre as coordenadas 28°21' e 28<>J4'sul e 53°40'e53°57'oeste. Os resultados evidenciaramas vantagens dos Sistemas de Informação Geográfica sobre os métodos convencionaisde análise, especialmenteno que se refere à velocidade, precisão e à associação dos dados de interesse à sua localização geográfica. ABSTRACT Geographic information systems have been widely used in studies involving naturalresourcesand environment planningand management. Agriculture is one of human activitiesthat most relate to the environment. This work investigates the use of geographic informationsystemsin order to integrateinformationrelatedto crop production and support agriculturalmanagementactivities.The studysitearea is located in Rio Grande do Sul State, Southern Brazil, within the "Planalto Médio" region in Não-me-Toque county (latitudes 28°21' to 28°34' South and longitudes 53°40'e 53°57' West). Results indicated the advantages of using geographic information systems when compared to the traditional methods,mainlydue to time consuming,precision and the possibilityof pointing data to its geographic position. IV
This paper presents some results of a project under development by PUCRS and AES Sul Distribuidor... more This paper presents some results of a project under development by PUCRS and AES Sul Distribuidora Gaúcha de Energia. One of the main objectives of the project is to build up a decision support system (DSS) in order to reduce time and to improve quality on planing and management of the energy distribution. This DSS aims to integrate data from different sources and types and to generate information for decision making on strategic and operational levels. The work describes the methodology followed in order to adjust an existing spatial database to a known coordinate system and to link it to the enterprise's corporative relational database, using Novo Hamburgo city, Rio Grande do Sul State, as study area. Results showed that existing spatial and attribute data can be integrated through a Geographic Information System, which facilitates queries and analyses over the whole area of interest of the company, enabling simulations to evaluate network charge and future demands and impacts. It makes possible in the future easily update the spatial and attribute data by field work using GPS, as well as better geographically distribute the field teams. keywords: geographic information systems, energy distributions, decision support systems.
This study presents a methodological proposal for landslide susceptibility mapping in the municip... more This study presents a methodological proposal for landslide susceptibility mapping in the municipality of Porto Alegre using a GIS approach. Variables, such as slope gradient, geology, distance from faults, upslope contributing area and potential runoff were considered the main conditioning factors of landslides. After pre-processing, all data layers were standardized using fuzzy functions and direct assignment of notes. Then, the degree to which each parameter is related to landslides was determined using the analytical hierarchy process method. The integration of the conditioning factors was based on the Weighted Linear Combination technique. The performance of susceptibility models was measured using success and prediction rates and computing the area under the curve.
... Heinrich Hasenack; Eliseu Weber; Rejane Valdameri ... Pode-se entender o planejamento como a ... more ... Heinrich Hasenack; Eliseu Weber; Rejane Valdameri ... Pode-se entender o planejamento como a aplicação racional do conhecimento do homem ao processo de tomada de decisões para conseguir uma ótima utilização dos recursos, a fim de obter o máximo de benefícios para ...
RESUMO: A interpolação é um procedimento comum para estimar dados de radiação onde não há registr... more RESUMO: A interpolação é um procedimento comum para estimar dados de radiação onde não há registros, mas geralmente não considera o efeito do relevo sobre a interceptação da luz solar. Em regiões acidentadas a quantidade e a duração da radiação solar recebida por locais com diferentes características topográficas apresenta forte variação, afetando a qualidade da produção ali obtida, especialmente no caso da viticultura. O objetivo deste estudo foi estimar a insolação potencial em superfícies inclinadas na zona de produção vitícola da Serra Gaúcha utilizando Modelo Digital de Elevação (MDE) e Sistema de Informação Geográfica (SIG). A duração da insolação foi estimada a partir do cálculo de um diagrama de obstrução para cada pixel do MDE e do percurso do Sol, variando seus ângulos azimutal e zenital em intervalos de 30 minutos, no primeiro decêndio de janeiro. Os resultados mostraram que a distribuição espacial da insolação apresenta uma alta variabilidade dentro da região, com difere...
The purpose of this study was to observe the influence of regional aspects such as climate, manag... more The purpose of this study was to observe the influence of regional aspects such as climate, management and occupancy of the soybean crops neighborhood, on the temporal evolution of the NDVI/NOAA images. The study was performed during 1999/2000, in the northwest region of Rio Grande do Sul - Brazil, and LANDSAT images were used to determine soybeans areas, and images of maximum monthly NDVI/NOAA, to monitor the temporal evolution of the NDVI. The NDVI values, extracted over selected areas in the LANDSAT images, were used to trace the spectral profiles and to identify groups with similar patterns of NDVI evolution (Ward grouping method). The results showed that it is possible to state that the NOAA images are a particularly useful instrument to monitor the surface, and that they express different conditions of cover and use in the neighborhood of soybeans crops. Pages: 197-204
Geoprocessing and remote sensing technologies enable real-time obtention of precise information w... more Geoprocessing and remote sensing technologies enable real-time obtention of precise information with a low cost/benefit ratio on the extent and conditions of crop development, which may render the current Brazilian harvest monitoring and forecast system more efficient and dynamic on a regional and national scale. The purpose of the present study was to analyze the temporal evolution of the normalized difference vegetation index (NDVI), obtained from NOAA-14 images in areas covered by pixels with variable proportion of soybeans, on for the purpose of monitoring soybean crops in regions where harvests are forecast. The study was performed during the agricultural year of 1999/2000, in the northwest region of the state of Rio Grande do Sul, and LANDSAT TM 7 images were used to determine areas planted with soy beans, and NOAA-14 images of maximum monthly NDVI, to monitor the temporal evolution of the NDVI in these areas. The NDVI values were extracted on sample windows over areas with va...
O estudo da variabilidade temporal do NDVI tem dado bons indicativos de como os ecossistemas resp... more O estudo da variabilidade temporal do NDVI tem dado bons indicativos de como os ecossistemas respondem às condições climáticas e ao manejo. Este trabalho busca avaliar a evolução temporal do NDVI no Estado do Rio Grande do Sul e no Uruguai, região com predomínio de vegetação campestre, a fim de fornecer subsídios para mapear seus remanescentes. A série temporal analisada contém 205 imagens de NDVI do sensor MODIS para o período de 2000 a 2009. Resultados preliminares mostram a tendência de decréscimo dos valores médios de NDVI considerando-se toda a área coberta pela imagem e que contém toda a variabilidade de cobertura do solo, assim como em amostras das regiões geomorfológicas do Planalto da Campanha e Depressão Central Gaúcha. Comparando com as ocorrências de La Niña para o mesmo período pode-se concluir que também estes eventos podem influenciar na tendência de diminuição da biomassa na região, pois tem provocado efeitos de seca recorrente. Esta diminuição da biomassa poderá ter...
The objective of this work was to evaluate sampling density on the prediction accuracy of soil or... more 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 errors, overall accuracy, and quantity and allocation disagreement. The decision tree was less sensitive to sampling density and had the highest accuracy and consistence. The SOM was the less sensitive and most consistent network. The MLP had a critical minimum and showed high inconsistency, whereas fuzzy ARTMap was more sensitive and less accurate. Results indicate that sampling densities used in conventional soil surveys can serve as a reference to predict soil orders in Serra Gaúcha.
Most of the world population lives in cities and Brazil follows this rule. Various objective and ... more Most of the world population lives in cities and Brazil follows this rule. Various objective and criteria were use to plan urban areas in Brazil, not allways taking into account what is really important. The city plans are elaborated with the aim to regulate the soil use and to preserve life quality. Different methods are used, involving statistics, mapping, zoning,
Traditional soil surveys follow a specific methodology to identify, characterize, and fit mapping... more Traditional soil surveys follow a specific methodology to identify, characterize, and fit mapping units in a classification system and to spatialize them in order to produce soil maps. The need for observation and characterization on field, associated with the physical and chemical analyses, makes the surveys expensive and therefore scarce. The low number of surveys stimulated the development of models for digital soil mapping, whose results proved to be possible to predict and spatialize many soil characteristics. However, conventional soil surveys remain important as a basis for the development of digital soil mapping models, setting a reason to continue the development of methodologies to improve the conventional surveys. Technologies like GPS and GIS contribute to make field observation and soil sampling more objective and make the mapping process and the production of hardmaps easier and faster. The objective of this study was to develop methodologies to integrate cartographic base elements with field work, using GIS and GPS in an area corresponding to 20 topographic charts in scale 1:50,000 in the State of Rio Grande do Sul, Southern Brazil, to obtain soil mapping based on the Brazilian Soil Classification System. The result obtained was a georeferenced digitized soil map, continuous for the whole region, free of inconsistency among neighbor map sheets and with attributes associated with the mapping units. These characteristics allow the use and application of the soil map for many purposes like zoning, diagnosis, suitability analysis as well as serving as a basis to the development of models for digital soil mapping.
Based on the analytical results described above, the vineyard soils of the Columbia Basin can be ... more Based on the analytical results described above, the vineyard soils of the Columbia Basin can be readily distinguished from those of the Willamette Valley and Snake River Valley. Relative to Columbia Basin soils, Willamette Valley soils are higher in iron, manganese, titanium, and organic matter, and lower in calcium, soluble salts, and pH. The contrasts in soil chemistry are attributable to significant differences in climate and soil parent material. The Willamette Valley receives 100 cm of annual precipitation, which is four times the average for the Columbia Basin, and Willamette Valley vineyard soils are developed not in loess, but in deeply weathered colluvium derived from basalt and sedimentary rocks (5). The sampled vineyard soils of the Snake River Valley could be distinguished from those of the Columbia Basin by lower concentrations of iron, manganese, and titanium and higher concentrations of soluble salts. The differences in soil chemistry can be attributed primarily to c...
Dissertação apresentada como um dos requisitos à obtenção do Grau de Mestre em SensoriamentoRemot... more Dissertação apresentada como um dos requisitos à obtenção do Grau de Mestre em SensoriamentoRemoto Porto Alegre (RS), Brasil. Dezembro de 1995 AGRADECIMENTOS Ao professorMoacir A. Berlato,por ter me aceito como seu orientado no Curso de pós-graduação em SensoriamentoRemoto; Ao professor Vitor Haertel, por ter aceitado a co-orientação e pelo apoio no sentido de concretizar o intercâmbio do CEPSRM com outras entidades; Ao professorAtos FreitasGrawunder,coordenador do Curso de Pós-graduação em Economia Rural da UFRGS, pelo auxílio na estruturação da presente dissertação; À Cooperativa Tritícola Mista Alto Jacuí Ltda, pelo apoio de campo e atenção dedicada à execução do trabalho, muitas vezes deslocando técnicos importantes de suas funções para o levantamento das informações necessárias; Ao professorAlfonsoRissoque, atravésda troca de idéiase sugestões, contribuiu na montagem do projeto; Ao Engenheiro Agrônomo Eduardo Juan Ruiz Posse, professor da Universidad Nacionalde Córdoba,RepúblicaArgentina,pela amizade e parceria na realização de tarefas e sugestões em assuntos relacionados à execução do trabalho; Aos colegas do curso de mestrado que compartilharam dificuldades e confraternizaram em vários eventos, tornando mais agradável o período do curso; Aos funcionáriostécnicos e administrativosdo CEPSRM que, de uma ou outra forma, prestaram sua colaboração à solução dos problemas surgidos durante o curso e contribuíram para a conclusão deste estudo. II USO DE SISTEMAS DE INFORMAÇÃO GEOGRÁFICA COMO SUBSÍDIO SINOPSE Os Sistemas de Informação Geográfica vêm sendo cada vez mais utilizados em estudos envolvendo o planejamento e gerenciamento de recursos e meio-ambiente. A agricultura é uma das atividades humanas mais intimamente relacionadas com o meioambiente. Este trabalho investiga o emprego desses sistemas para integrar diferentes informações relacionadas à produção agrícola e obter respostas que subsidiem o planejamentoem regiõesagrícolas.A área estudada é uma localidade do município de Nãome-Toque, situado no planalto médio do Rio Grande do Sul, entre as coordenadas 28°21' e 28<>J4'sul e 53°40'e53°57'oeste. Os resultados evidenciaramas vantagens dos Sistemas de Informação Geográfica sobre os métodos convencionaisde análise, especialmenteno que se refere à velocidade, precisão e à associação dos dados de interesse à sua localização geográfica. ABSTRACT Geographic information systems have been widely used in studies involving naturalresourcesand environment planningand management. Agriculture is one of human activitiesthat most relate to the environment. This work investigates the use of geographic informationsystemsin order to integrateinformationrelatedto crop production and support agriculturalmanagementactivities.The studysitearea is located in Rio Grande do Sul State, Southern Brazil, within the "Planalto Médio" region in Não-me-Toque county (latitudes 28°21' to 28°34' South and longitudes 53°40'e 53°57' West). Results indicated the advantages of using geographic information systems when compared to the traditional methods,mainlydue to time consuming,precision and the possibilityof pointing data to its geographic position. IV
This paper presents some results of a project under development by PUCRS and AES Sul Distribuidor... more This paper presents some results of a project under development by PUCRS and AES Sul Distribuidora Gaúcha de Energia. One of the main objectives of the project is to build up a decision support system (DSS) in order to reduce time and to improve quality on planing and management of the energy distribution. This DSS aims to integrate data from different sources and types and to generate information for decision making on strategic and operational levels. The work describes the methodology followed in order to adjust an existing spatial database to a known coordinate system and to link it to the enterprise's corporative relational database, using Novo Hamburgo city, Rio Grande do Sul State, as study area. Results showed that existing spatial and attribute data can be integrated through a Geographic Information System, which facilitates queries and analyses over the whole area of interest of the company, enabling simulations to evaluate network charge and future demands and impacts. It makes possible in the future easily update the spatial and attribute data by field work using GPS, as well as better geographically distribute the field teams. keywords: geographic information systems, energy distributions, decision support systems.
This study presents a methodological proposal for landslide susceptibility mapping in the municip... more This study presents a methodological proposal for landslide susceptibility mapping in the municipality of Porto Alegre using a GIS approach. Variables, such as slope gradient, geology, distance from faults, upslope contributing area and potential runoff were considered the main conditioning factors of landslides. After pre-processing, all data layers were standardized using fuzzy functions and direct assignment of notes. Then, the degree to which each parameter is related to landslides was determined using the analytical hierarchy process method. The integration of the conditioning factors was based on the Weighted Linear Combination technique. The performance of susceptibility models was measured using success and prediction rates and computing the area under the curve.
... Heinrich Hasenack; Eliseu Weber; Rejane Valdameri ... Pode-se entender o planejamento como a ... more ... Heinrich Hasenack; Eliseu Weber; Rejane Valdameri ... Pode-se entender o planejamento como a aplicação racional do conhecimento do homem ao processo de tomada de decisões para conseguir uma ótima utilização dos recursos, a fim de obter o máximo de benefícios para ...
RESUMO: A interpolação é um procedimento comum para estimar dados de radiação onde não há registr... more RESUMO: A interpolação é um procedimento comum para estimar dados de radiação onde não há registros, mas geralmente não considera o efeito do relevo sobre a interceptação da luz solar. Em regiões acidentadas a quantidade e a duração da radiação solar recebida por locais com diferentes características topográficas apresenta forte variação, afetando a qualidade da produção ali obtida, especialmente no caso da viticultura. O objetivo deste estudo foi estimar a insolação potencial em superfícies inclinadas na zona de produção vitícola da Serra Gaúcha utilizando Modelo Digital de Elevação (MDE) e Sistema de Informação Geográfica (SIG). A duração da insolação foi estimada a partir do cálculo de um diagrama de obstrução para cada pixel do MDE e do percurso do Sol, variando seus ângulos azimutal e zenital em intervalos de 30 minutos, no primeiro decêndio de janeiro. Os resultados mostraram que a distribuição espacial da insolação apresenta uma alta variabilidade dentro da região, com difere...
The purpose of this study was to observe the influence of regional aspects such as climate, manag... more The purpose of this study was to observe the influence of regional aspects such as climate, management and occupancy of the soybean crops neighborhood, on the temporal evolution of the NDVI/NOAA images. The study was performed during 1999/2000, in the northwest region of Rio Grande do Sul - Brazil, and LANDSAT images were used to determine soybeans areas, and images of maximum monthly NDVI/NOAA, to monitor the temporal evolution of the NDVI. The NDVI values, extracted over selected areas in the LANDSAT images, were used to trace the spectral profiles and to identify groups with similar patterns of NDVI evolution (Ward grouping method). The results showed that it is possible to state that the NOAA images are a particularly useful instrument to monitor the surface, and that they express different conditions of cover and use in the neighborhood of soybeans crops. Pages: 197-204
Geoprocessing and remote sensing technologies enable real-time obtention of precise information w... more Geoprocessing and remote sensing technologies enable real-time obtention of precise information with a low cost/benefit ratio on the extent and conditions of crop development, which may render the current Brazilian harvest monitoring and forecast system more efficient and dynamic on a regional and national scale. The purpose of the present study was to analyze the temporal evolution of the normalized difference vegetation index (NDVI), obtained from NOAA-14 images in areas covered by pixels with variable proportion of soybeans, on for the purpose of monitoring soybean crops in regions where harvests are forecast. The study was performed during the agricultural year of 1999/2000, in the northwest region of the state of Rio Grande do Sul, and LANDSAT TM 7 images were used to determine areas planted with soy beans, and NOAA-14 images of maximum monthly NDVI, to monitor the temporal evolution of the NDVI in these areas. The NDVI values were extracted on sample windows over areas with va...
O estudo da variabilidade temporal do NDVI tem dado bons indicativos de como os ecossistemas resp... more O estudo da variabilidade temporal do NDVI tem dado bons indicativos de como os ecossistemas respondem às condições climáticas e ao manejo. Este trabalho busca avaliar a evolução temporal do NDVI no Estado do Rio Grande do Sul e no Uruguai, região com predomínio de vegetação campestre, a fim de fornecer subsídios para mapear seus remanescentes. A série temporal analisada contém 205 imagens de NDVI do sensor MODIS para o período de 2000 a 2009. Resultados preliminares mostram a tendência de decréscimo dos valores médios de NDVI considerando-se toda a área coberta pela imagem e que contém toda a variabilidade de cobertura do solo, assim como em amostras das regiões geomorfológicas do Planalto da Campanha e Depressão Central Gaúcha. Comparando com as ocorrências de La Niña para o mesmo período pode-se concluir que também estes eventos podem influenciar na tendência de diminuição da biomassa na região, pois tem provocado efeitos de seca recorrente. Esta diminuição da biomassa poderá ter...
The objective of this work was to evaluate sampling density on the prediction accuracy of soil or... more 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 errors, overall accuracy, and quantity and allocation disagreement. The decision tree was less sensitive to sampling density and had the highest accuracy and consistence. The SOM was the less sensitive and most consistent network. The MLP had a critical minimum and showed high inconsistency, whereas fuzzy ARTMap was more sensitive and less accurate. Results indicate that sampling densities used in conventional soil surveys can serve as a reference to predict soil orders in Serra Gaúcha.
Most of the world population lives in cities and Brazil follows this rule. Various objective and ... more Most of the world population lives in cities and Brazil follows this rule. Various objective and criteria were use to plan urban areas in Brazil, not allways taking into account what is really important. The city plans are elaborated with the aim to regulate the soil use and to preserve life quality. Different methods are used, involving statistics, mapping, zoning,
Traditional soil surveys follow a specific methodology to identify, characterize, and fit mapping... more Traditional soil surveys follow a specific methodology to identify, characterize, and fit mapping units in a classification system and to spatialize them in order to produce soil maps. The need for observation and characterization on field, associated with the physical and chemical analyses, makes the surveys expensive and therefore scarce. The low number of surveys stimulated the development of models for digital soil mapping, whose results proved to be possible to predict and spatialize many soil characteristics. However, conventional soil surveys remain important as a basis for the development of digital soil mapping models, setting a reason to continue the development of methodologies to improve the conventional surveys. Technologies like GPS and GIS contribute to make field observation and soil sampling more objective and make the mapping process and the production of hardmaps easier and faster. The objective of this study was to develop methodologies to integrate cartographic base elements with field work, using GIS and GPS in an area corresponding to 20 topographic charts in scale 1:50,000 in the State of Rio Grande do Sul, Southern Brazil, to obtain soil mapping based on the Brazilian Soil Classification System. The result obtained was a georeferenced digitized soil map, continuous for the whole region, free of inconsistency among neighbor map sheets and with attributes associated with the mapping units. These characteristics allow the use and application of the soil map for many purposes like zoning, diagnosis, suitability analysis as well as serving as a basis to the development of models for digital soil mapping.
Based on the analytical results described above, the vineyard soils of the Columbia Basin can be ... more Based on the analytical results described above, the vineyard soils of the Columbia Basin can be readily distinguished from those of the Willamette Valley and Snake River Valley. Relative to Columbia Basin soils, Willamette Valley soils are higher in iron, manganese, titanium, and organic matter, and lower in calcium, soluble salts, and pH. The contrasts in soil chemistry are attributable to significant differences in climate and soil parent material. The Willamette Valley receives 100 cm of annual precipitation, which is four times the average for the Columbia Basin, and Willamette Valley vineyard soils are developed not in loess, but in deeply weathered colluvium derived from basalt and sedimentary rocks (5). The sampled vineyard soils of the Snake River Valley could be distinguished from those of the Columbia Basin by lower concentrations of iron, manganese, and titanium and higher concentrations of soluble salts. The differences in soil chemistry can be attributed primarily to c...
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