EVALUATING A MULTI-VELOCITY HYDROLOGICAL PARAMETERIZATION IN THE AMAZON BASIN

Abstract

This paper describes a multi-velocity TOPMODEL approach applied to the Amazon basin. Comparison with the original TOPMODEL approach evaluates this new approach in terms of hydrograph simulation, physical meaning of the parameters and sub-surface flow generation. The new meteorological data and the improvements in estimates of area and distances may be responsible for higher efficiencies of both model approaches. Hydrograph simulation indicates, since the parameters are constrained according to literature review, that the multi-velocity approach performs quite better and the sub-surface flow parcel in the total flow is consistent with tracer studies carried out in the basin. There are evidences that higher values of saturated hydraulic transmissivity in the original model approach are a model response to compensate the spatial invariant velocity parameterization and/or the grid resolution. The multi-velocity model approach seems to be a suitable alternative, since it represents in a better way the sub-surface flow and whence saturated areas in Amazon basin.