Fluvial landforms were analysed at regional scale in terms of their dissection, channel patterns and other geomorphic features to give support to geomorphological and geological mapping of central Amazon. The confluence region of Japurá and Solimões rivers and 200km downstream were studied using remote sensing (Landsat Thematic Mapper images, radar mosaics, 1:250,000), hydrological map and also considering the information from RADAM project maps. This area has been recently reinterpreted for SIVAM project and requires a high number of scenes due to its dense rainforest cover and persistent clouds.

The Lower Solimões and the Japurá rivers develop a wide Holocene floodplain that crosses two sedimentary units of the Solimões basin. On its north western to south eastern course, Solimões changes from meandering to braided pattern and cut Tertiary sediments of the Solimões Formation on the right margin, and Pleistocene sediments identified as the Içá Formation on the left margin. The first one can be identified based on its dissection pattern with a relatively high drainage density. The drainage network is neotectonically controlled and two main directions of the streams were observed: NE-SW for the main channels and lakes, and NW-SE for the secondary channels.

On the north eastern region, on the left margin, a reworked surface texture on image reveals a dissection pattern with a lower drainage density, also presenting linear segments on its drainage network. The W-E and NW-SE directions mark a recent morphotectonic evolution printed on the rivers. In addition, Pleistocene sediments show old meander scrolls and paleochannels as common geomorphic features easily observed on images.

The remote sensing data is being extremely useful under a mega-geomorphology perspective, enabling strong associations between the dissection patterns of the Lower Solimões region and their lithological units.