Influência das características naturais das bacias de drenagem sobre as propriedades físico-químicas do rio Solimões/Amazonas e seus principais tributários brasileiros

Abstract

The natural characteristics of the drainage basin significantly influence the chemical composition of the water. In the present study we evaluated the influence of relief, hydromorphic soils, floodplains and concentration in stream sediment, carbon, phosphorus and nitrogen and also the pH. To quantify the natural features were used high-resolution images integrated into a geographic information system (GIS). The geochemical parameters were average values Cruise CAMREX project. To evaluate the influence of natural factors on water quality analyzes were performed multiple linear regression (stepwise). Particulate matter from rivers, total suspended sediment (TSS) and particulate organic carbon (POC), were strongly correlated with the average slope upstream watershed. The percentage of Andean land exerts a strong influence on the chemical composition of water, while the percentage of land shell was not significant in the study. Dissolved organic carbon (DOC) correlated with the percentage of floodplains and hydromorphic podzols in upstream watersheds. The dissolved inorganic carbon (DIC) and total phosphorus (TP) and total nitrogen (TN) had significant correlation with the amount raised in the drainage basin. The pH correlated with the relief that helps with carbonates of marine origin and also percentage of hydromorphic podzols that provide considerable amount of humic and fulvic acids to the river system. This work opens a new perspective in predicting water quality at any point of the Amazon basin, since currently offers high-resolution images that allow quantifying the natural characteristics of the basin and through the equations generated by the models quantify the different forms of C, P, N, but also for the pH and sediments.