This work has been developed in the National Park of Jau, middle course of Negro River, Amazonas State. On a map constructed from aerial photographs and satellite images, covering around 190 km2 of the study area at scale 1:80 000, it has been identified 9 geomorphological units:
- Plateau presenting relief of gentle hills on the edges (corresponding to forest vegetation);
- Proto-depression at 1st stage of development (zones with slight deficiency of drainage covered by forest
- vegetation);
- Proto-depressions at 2nd stage of development (corresponding to high campinarana vegetation);
- Proto-depressions at 3rd stage of development (corresponding to low campinarana vegetation);
- Depressions (corresponding to campina vegetation);
- 1st floodplain;
- 2nd floodplain;
- Terraces and
- Paleochannel.
In the area of field study a transect survey heading south was executed along 4 300m, from the right margin of Jau River until the zone of depressions of the Jau - Carabinani divide. The units of geomorphology and vegetation as well as the soil information adquired with the auger were placed along the topographic profile obtained. It was noticed good correspondence between soil, vegetation and geomorphology features. The last 230m were studied in toposequence, with 11 points of auger sounding and 3 trenches placed from the top of a gentle hill, covered by forest, to the depression, covered by open vegetation (campina). The data shows the existence of a oxisol/spodosol system, where the last one develops, from downslope to upslope, at the expenses of the first one and, locally, of the sandstone of Formaçao Prosperança. This transformation is related to the clay, iron and organic matter exportation, and migth explain the lowering and the morphology of the relief.