Análise da erosão do solo usando a EUPS, através de técnicas de sensoriamento remoto e geoprocessamento / Soil erosion analysis, using the USLE, using both remote sensing and geoprocessing techniques

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

14/11/1996

RESUMO

The Universal Soil Loss Equation (USLE) has been used within geographical information systems targeting the development of means of producing basic planning information. Remote sensing data have been used to map the most dynamic side of erosion: land use and management. Overestimations of erosion and Natural Erosion Potential have been regularly obtained, though, in bidimensional models. Due to the newness of these studies there is not enough data trying to explain why these overestimations occur. This present work developed two hypotheses: first, that the derivation of the land use factor (factor C)based either on aerophotography or orbital imagery takes to similar final results, in terms of soil loss prediction, and that the topographic factor is the main cause of out-of-scope values when using USLE for slopes longer than 300m. TM-Landsat imagery and erial photography produced different results in terms of punctual erosion, but much coherent in a synoptic view of the geographical distribution of erosion on the catchment. Higher values concentrated, for both products, around natural drainage, which reflects the strong influence of the topographic factor, mainly the slope-length fraction. The results show the necessity of a more accurate regression equation for slope length if USLE is to be used to predict erosion in small catchments. This model shall support the presence of values as high as those found in nature. A bidimensional model for slope length must also consider the presence of roads and terracing, as well as other structures that might alter run-off direction. Finally, it was demonstrated that it is possible to conduct all the modeling steps, including out-put, within one geographic information system alone, avoiding time consumption through software migration, the only limitation being the correct choice of the system to be used.

ASSUNTO(S)

sumare (sp) microbacia do côrrego pinheirinho (sp) erosão solos microbacias sistemas de informação geográfica encostas equação universal de perda de solo (eups) imagem orbital fotografia aérea planejamento agrícola drenagem sig soil erosion geographic information systems hypotheses aerial photography topography land management drainage slopes land use

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