Caracterização dos padrões de drenagem a partir de técnicas de sensoriamento remoto para uso em levantamentos de reconhecimento (alta intensidade) de solos.

Abstract

Detailed soil surveys have attached growing importance in recent years. In this context, remote sensing products and techniques have been used successfully for a number of researchers to speed up analysis and mapping processes. The present study was based on 1984-TM/LANDSAT-5 imagery of the region of Alto Rio Sucuru - Semi-arid Zone of the State of Paraíba. It reports a pedological analysis of this area, presents geological, pedological and land use information and studies their influence on the composition and the characteristics of the drainage pattens of the soil units presented on the High-Intensity Reconnaissance Survey made of on a scale of 1:100.000. An interpretation methodology of low spatial resolution data as well as a ground work approach were both applied. Using the method of the mapping unit, the composition and the characteristics of the drainage pattern mapped from the TM/LANDSAT-5 imagery were studied. This methodology was applied later on topographical maps elaborated by SUDENE and compared to the method of circular samples. A 73 soil spots set, grouped into 16 mapping units, was identified. The study of the drainage pattern of these units revealed a good unit differentiation results, e.g. between the units composed by PODZÓLICOS VERMELHO AMARELO EUTRÓFICOS (Eutrophic Red Yellow Podzolic) and REGOSSOLCS EUTRÓFiCOS (Eutrophic Regosois) and those composed by BRUNOS NÃO CÁLCICOS (Non Calcic Brown Soils) and LITÓLSCOS EUTRÓFICOS (Eutrophic Lithosols). Satisfactory results for the quantitative drainage parameters, specially for the drainage density and river frequency, were remarked from the drainage map Although the efficiency of the method of circular samples on soil differentiation was confirmed, the methodology proposed here presented more satisfactory results, by allowing a better analysis of mapping units irregardless their morphology, structure and shape.