This paper presents a methodology to minimize the slope softening effect caused by pixel variations in the Digital Elevation Model (DEM) interpolation used in Geographic Information Systems. The studied area is part of Rio Piracicaba (São Paulo State, Brazil) watershed, located in a very steep site in order to point out the high variability slope aspects of the region. Slope maps with 100, 125, 200 and 250 m pixels were produced. Transects were overlayed on them to provide data for correlation analysis. The method confirmed the high variability among the slope maps. Furthermore, alternatives to avoid the slope softening effect and data precision losses were established.
slope; imagery; geographic information system; watershed; accuracy
