Aplicação de dados SRTM à modelagem da erosão em microbacias por geoprocessamento / Application of srtm data to the modelling of erosion in watersheds using geoprocessing

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The Universal Soil-Loss Equation (USLE) is a widely used method for calculating annual soil erosion losses, based on rainfall, soil type, topographic and land-use parameters. This study was designed to apply SRTM data for erosion modeling through USLE. The analysis of two watersheds in Maranhão showed the feasibility of remote sensing applications beyond land-use survey, since SRTM was used for watershed and drainage extraction, topographic factor (LS) estimates and for the refining of pedological maps, allowing the substitution of maps of limited detail and availability. Topographic factor (from SRTM), climate erosivity, soil erodibility and land use factor, adapted from soil conservation research, were overlaid to the calculation of Natural Erosion Potential (NEP), annual soil loss and erosion expectation. Results showed low overall erosion levels, below 10t/ha.year, under forests, degraded natural vegetation or pastures (31,185.23ha or 94.55% of the study area). In agricultural areas (1,642.14ha or 4.98% of the study area), an intense erosion process occur, with soil loss rates above 40t/ha.year. Results indicated LS factor to prevail over erosivity (R) and erodibility (K) factor in the distribution of natural potential erosion. Otherwise, land-use and managing practices factor (CP) prevailed in the distribution of annual effective erosion and of the calculated soil loss expectation.

ASSUNTO(S)

sensoriamento remoto

ACESSO AO ARTIGO

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