Comparison between detailed digital and conventional soil maps of an area with complex geology

Autor: Osmar Bazaglia Filho, Rodnei Rizzo, Igo Fernando Lepsch, Hélio do Prado, Felipe Haenel Gomes, Jairo Antonio Mazza, José Alexandre Melo Demattê
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Revista Brasileira de Ciência do Solo, Vol 37, Iss 5, Pp 1136-1148 (2013)
Druh dokumentu: article
ISSN: 1806-9657
0100-0683
DOI: 10.1590/S0100-06832013000500003
Popis: Since different pedologists will draw different soil maps of a same area, it is important to compare the differences between mapping by specialists and mapping techniques, as for example currently intensively discussed Digital Soil Mapping. Four detailed soil maps (scale 1:10.000) of a 182-ha sugarcane farm in the county of Rafard, São Paulo State, Brazil, were compared. The area has a large variation of soil formation factors. The maps were drawn independently by four soil scientists and compared with a fifth map obtained by a digital soil mapping technique. All pedologists were given the same set of information. As many field expeditions and soil pits as required by each surveyor were provided to define the mapping units (MUs). For the Digital Soil Map (DSM), spectral data were extracted from Landsat 5 Thematic Mapper (TM) imagery as well as six terrain attributes from the topographic map of the area. These data were summarized by principal component analysis to generate the map designs of groups through Fuzzy K-means clustering. Field observations were made to identify the soils in the MUs and classify them according to the Brazilian Soil Classification System (BSCS). To compare the conventional and digital (DSM) soil maps, they were crossed pairwise to generate confusion matrices that were mapped. The categorical analysis at each classification level of the BSCS showed that the agreement between the maps decreased towards the lower levels of classification and the great influence of the surveyor on both the mapping and definition of MUs in the soil map. The average correspondence between the conventional and DSM maps was similar. Therefore, the method used to obtain the DSM yielded similar results to those obtained by the conventional technique, while providing additional information about the landscape of each soil, useful for applications in future surveys of similar areas.
Databáze: Directory of Open Access Journals
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