Defining geomorphological unities from navigation and validation of fields by using GPS and Geographic Informaton System: the case of Rio Castelo watershed

Abstract

The present work describes the static and kinematic procedures for surveying,
controlling and navigation of point features determined by Geodesic GPS in order
to aid the field work of defining the geomorphological units as input for the
physiographic characterization and geoenvironmental diagnosis of Rio Castelo
Watershed (SBHRC), located on the south of Espírito Santo’s State, Brazil. The
SBHRC has an area about 1500 Km² covering 6 districts. Because of the extent of
the study area and the work scale of 1:75,000, the survey would be too expensive or
even unfeasible if there weren’t a perfect synchronization and between the field
positioning and data stored in the cartographic base. The primary definition of
geomorphologic units is part of the physiographic characterization of the study area,
object of studies of geoenvironmental diagnosis and zoning. GIS and image
processing tools for LANDSAT TM5 and SRTM Radar images were used in the
associated with GPS equipments to field validation were used in the
geomorphologic compartmentation. The utilization of GPS, orbital imagery and GIS
altogether allowed elaborating a product of detailed environmental analysis, in a
proper scale, validated by the evaluations in loco and with great potential for
systematic evaluation of natural resources.