Technical Note: A hydrological routing scheme for the Ecosystem Demography model (ED2+R)

Abstract

Land surface models are excellent tools for studying how climate change and land use affect surface hydrology. However, in order to assess the impacts of earth processes on river flows, simulated changes in runoff need to be routed through the landscape using a hydrological transport scheme. In this Technical Note we describe the integration of the Ecosystem Demography (ED2) model with a hydrological routing scheme. ED2 is a terrestrial biosphere model capable of incorporating sub-grid scale ecosystem heterogeneity arising from land-use change, making it ideally suited for investigating combined impacts of changes in climate, atmospheric carbon dioxide concentrations, and land-cover on the water cycle. The resulting ED2+R model calculates the lateral propagation of surface and subsurface runoff resulting from the terrestrial biosphere models’ vertical water balance in order to determine spatio-temporal patterns of river flows within the simulated region. We evaluated the ED2+R model in the Tapajós, a large river basin in southeastern Amazonia, Brazil. The results showed that the integration of ED2 with the lateral routing scheme substantially improves the ability of the model to reproduce daily to decadal river flow dynamics in the Tapajós.