Promoting the integration of Engineering, Ecology and Limnology: the Ecohydrological approach applied to Amazon reservoir construction.

Amazon watersheds are a complex ecosystem: the interaction between terrestrial and aquatic ecosystems and the water level fluctuations are the main forcing function that regulates the biodiversity, the evolutionary processes and the interaction between terrestrial and aquatic biota in the large internal deltas, the extensive floodplains regions and the network of channels, creeks, rivers, meanders and lakes (Haffer, 2008). Chemical and physical environment resulting from the inundation periods and the forest, promotes a chain of morphological, anatomical, physiological, geological and ethological adaptations with its characteristics structures (Junk et al., 1989; Alho, 2008). Food chains show large changes in their connections and organization during and after the flooding period (Junk, 1997). Reservoirs disrupt the dynamics of these ecosystems and change the organization patterns of floodplains, lakes creeks and rivers (Tundisi et al., 2008c). Large reservoirs affect the forest cover, due to deforestation of the future inundation area; reservoir also changes the fluvial dynamics, upstream and downstream the Power Plant Unit (Agostinho et al., 2009). In order to preserve the main ecological functions of the Amazonian ecosystems it is necessary to introduce ecohydrological concepts combined with engineering procedures in the construction of the Amazonian reservoirs. This also includes the perspectives of the influence of future climatic changes in the hydrological cycles (Martinelli et al., 2012). Since hydropower from the Amazon watershed is essential to Brazil, a well designed operation system for reservoir construction, should consider: