Trend-surfaces analysis of morphometric parameters: A case-study in southearstern Brazil
Date created: | Last Updated:
: DOI | ARK
Creating DOI. Please wait...
Description: Trend-surface analysis was carried out on data from morphometric parameters isobase and hydraulic gradient. The study area, located in the eastern border of Quadrilátero Ferrífero, southeastern Brazil, presents four main geomorphological units, one characterized by fluvial dissection, two of mountainous relief, with a scarp of hundreds of meters of fall between them, and a flat plateau in the central portion of the fluvially-dissected terrains. Morphometric maps were evaluated in GRASS-GIS and statistics were made on R statistical language, using the spatial package. Analysis of Variance (ANOVA) was made to test the significance of each surface and the significance of increasing polynomial degree. The best results were achieved with 6th-order surface for isobase and 2nd-order surface for hydraulic gradient. Shape and orientation of residuals maps contours for selected trends were compared with structures inferred from several morphometric maps, and a good correlation is present.