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Abstract

Landsat 7 Enhanced Thematic Mapper Plus image data was used to identify and map lateritic soil zones in the Phrae basin which is one of the largest intermountain basins in northern Thailand. The lateritic soil zones were discriminated using band ratio and principal component analysis. The lateritic soil detection images were processed by band ratio (band 3 / band 1), principal component analysis of bands 1 and 3, and principal component analysis of bands 1, 3, 4, and 5. The results of these three indices were superimposed using GIS to define a preliminary lateritic soil image of the study area. A threshold method was used for converting a grey scale image into a binary image. Different threshold values were used to find the most probable areas of lateritic soil zones in the image. The threshold values were determined from a published geological map and known lateritic soil areas with good exposure in the image. The quality of the results was evaluated by the normalized difference vegetation index. Field investigation was carried out to substantiate the remote sensing investigation and the laboratory GIS analysis. This method can also be applied to other lateritic soil and iron oxide regions.

Imagens Landsat-7/Etm+ E SRTM Como Ferramentas Auxiliares Na Identificação De Perfis Lateríticos – Exemplo Em Bom Jesus Da Penha (Mg).

“…A investigação dos perfis lateríticos com uso de Landsat-7/ETM+ foi alvo de uma série de trabalhos, como Soe et al (2008), Dogan (2009) e Madeira et al (2010). Aqui optou-se por aplicar as composições propostas por Andrews Deller ( 2006) para imagens de satélite Landsat-7/ETM+.…”

Investigating Lateritic Soil Properties and Impacts from Quarrying Activity on Communities in Southern Thailand: A Case Study

“…Soil quarry locations are indicated on GIS maps supplemented by survey data to assist planners when sourcing materials and for mitigating likely impacts on the communities. Scope of the website may be extended in the future to include soil deposits in other provinces [6].…”