Comparação de abordagens metodológicas para avaliação do potencial de ocorrência de processos erosivos na Bacia Hidrográfica do Córrego do Jaú, Aparecida D’Oeste – SP
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Data
2019-02-28
Autores
Carvalho, Mariana Barbosa de
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Universidade Estadual Paulista (Unesp)
Resumo
A erosão, especialmente do tipo acelerada, é um fenômeno com grande potencial de causar degradação ambiental, diminuindo a produção de alimentos, provocando a desertificação de áreas, o assoreamento de rios, o deslizamento de solo, entre outros. Dessa forma, o estudo dos processos erosivos e suas consequências é de fundamental importância em diversas áreas do conhecimento, exatamente para que possam ser propostas formas de remediar os casos já existentes e prevenir possíveis próximas ocorrências. Dentre os tipos de erosão existentes destaca-se a hídrica, e os parâmetros envolvidos nesse cenário podem ser diversos, envolvendo tanto fatores naturais, como as propriedades do solo, o clima e o relevo, quanto antropogênicos, como a ocupação do solo e técnicas de manejo. Além disso, uma ferramenta muito utilizada nos estudos de suscetibilidade à erosão é o SIG, ou Sistemas de Informações Geográficas, devido à sua capacidade de armazenar, manipular, analisar e apresentar dados distribuídos espacialmente e georreferenciados. O uso dessa ferramenta proporciona tanto a melhora na precisão dos valores obtidos, quanto diminui o tempo consumido durante os cálculos. Assim, o objetivo deste trabalho foi avaliar os resultados de diferentes abordagens de avaliação do potencial de ocorrência de erosão na Bacia Hidrográfica do Córrego do Jaú, em Aparecida D’Oeste – SP, envolvendo diversos parâmetros naturais e antrópicos, e utilizando sistemas de informações geográficas, de forma a verificar a aplicabilidade desses métodos na bacia de estudo. Para o estudo proposto foram aplicados os métodos da Vulnerabilidade Natural à Erosão (VNE) e adaptações da Equação Universal da Perda de Solo (USLE), além da comparação dos resultados com registros de processos erosivos na área de estudo. Em todos os casos analisados o fator uso e cobertura do solo foi de grande importância para o resultado final, assim como o fator topográfico. Verificou-se ainda que o método do VNE gerou os mapas mais abrangentes e os menores valores de susceptibilidade à erosão, enquanto os mapas da USLE com o fator LS simplificado e o uso do fator práticas conservacionistas foi considerado como a representação mais fiel da área de estudo.
Erosion, especially the accelerated type, is a phenomenon with high potential to cause environmental degradation, declining food production, causing desertification of areas, siltation of rivers, landslides, among others. Thus, the study of erosion and its consequences is of fundamental importance in many areas of knowledge, so that ways to remedy existing cases of it and prevent possible subsequent occurrences can be proposed. Among the existing types of erosion, the one caused by water stands out, and the parameters involved in this scenario may be diverse, involving both natural factors, such as soil properties, climate and relief, and anthropogenic ones, such as soil occupation and management. In addition, a tool widely used in erosion susceptibility studies is GIS, due to its ability to store, manipulate, analyze and present spatially distributed and geo-referenced data. The use of this tool provides both the improvement in the accuracy of the values obtained and the reduction of time consumed during calculations. So, the objective of this study was to evaluate the results of different approaches to assess the potential for erosion occurrence in the Córrego do Jaú watershed, in Aparecida D'Oeste – SP, involving several natural and anthropic parameters, and using geographic information systems, in order to verify the applicability of these methods in the study basin. For the proposed study, the methods of the Natural Vulnerability to Erosion (VNE) and adaptations of the Universal Soil Loss Equation (USLE) were applied, in addition to comparing the results with records of erosion processes in the region of study. In all cases analyzed, the use and land cover factor was of great importance for the final result, as well as the topographic factor. It was also verified that the VNE method generated the most comprehensive maps and the lowest values of susceptibility to erosion, whereas the USLE maps with the simplified LS factor and the use of the conservationist practices factor was considered as the most faithful representation of the studied area.
Erosion, especially the accelerated type, is a phenomenon with high potential to cause environmental degradation, declining food production, causing desertification of areas, siltation of rivers, landslides, among others. Thus, the study of erosion and its consequences is of fundamental importance in many areas of knowledge, so that ways to remedy existing cases of it and prevent possible subsequent occurrences can be proposed. Among the existing types of erosion, the one caused by water stands out, and the parameters involved in this scenario may be diverse, involving both natural factors, such as soil properties, climate and relief, and anthropogenic ones, such as soil occupation and management. In addition, a tool widely used in erosion susceptibility studies is GIS, due to its ability to store, manipulate, analyze and present spatially distributed and geo-referenced data. The use of this tool provides both the improvement in the accuracy of the values obtained and the reduction of time consumed during calculations. So, the objective of this study was to evaluate the results of different approaches to assess the potential for erosion occurrence in the Córrego do Jaú watershed, in Aparecida D'Oeste – SP, involving several natural and anthropic parameters, and using geographic information systems, in order to verify the applicability of these methods in the study basin. For the proposed study, the methods of the Natural Vulnerability to Erosion (VNE) and adaptations of the Universal Soil Loss Equation (USLE) were applied, in addition to comparing the results with records of erosion processes in the region of study. In all cases analyzed, the use and land cover factor was of great importance for the final result, as well as the topographic factor. It was also verified that the VNE method generated the most comprehensive maps and the lowest values of susceptibility to erosion, whereas the USLE maps with the simplified LS factor and the use of the conservationist practices factor was considered as the most faithful representation of the studied area.
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Palavras-chave
Erosão, USLE, Vulnerabilidade, SIG, Erosion, Vulnerability, GIS