Influence of different relief information sources on the geomorphological characterization of small watersheds

Mathematical models have been widely used to quantify hydrological processes for various practical purposes. These depend on geomorphological attributes which are derived from relief information represented by Digital Elevation Models (DEM). The objective of this study was evaluate the influence sources (ASTER, SRTM-30, SRTM-90, and TOPO) over characterization five Brazilian watersheds. Geoprocessing tools were applied extraction following each DEM: drainage area, perimeter, watershed slope; length slope main stream; total streams; bifurcation, stream area ratios; highest order stream. differences in values calculated relation reference DEM (TOPO). It found that: i) bifurcation ratio most sensitive parameters regarding source; ii) flat watersheds more susceptible altimetric errors; iii) ASTER did not adequately represent networks watersheds; iv) increased as decreased. results indicate that may exert use attributes.