Case Study 1: Integrated Analysis of a Humid Tropical Region — The Amazon Basin

Abstract

The Amazon makes for an excellent test case for developing a model of how hydrological and biogeochemical cycles function at the land surface on regional to continental scales. With an area of 6 Mkm² containing the largest stand of tropical rainforest in the world, it contributes 15% of the global freshwater discharged to the oceans, and condensational energy release from convective precipitation is of sufficient magnitude to influence global climatic patterns. Its major tributaries represent different climate, soil, and topographic regimes. It is large scale and represents a series of hydrological and chemical regimes that are not atypical of world rivers (Stallard and Edmond 1983). As much of the Amazon is mostly undisturbed by anthropogenic activity, it provides one of the few opportunities left to develop models of how basins function, against which future change can be assessed. It is also relatively well-characterised, even over large scales. Given the heterogeneous nature of precipitation and precipitation Instrumentation, river discharge is perhaps the most robust integrator of the long-term hydrological properties of a drainage basin.