COMPUTATIONAL DISCRETIZATION EFFECT ON RAINFALL-RUNOFF SIMULATION

Modeling catchment runoff require spatial discretization of the catchment for computation. This study investigates the effect that the size of the computational discretization has on the results of a simulation. Three different types of models (namely, a rational formula model, an Australian nonlinear conceptual model (RORB), and a physical-process-based distributed model (HEC-1) were tested by applying them to a hypothetical catchment. For each model the spatial discretization size for computations was systematically decreased, while all other catchment and model parameters were held constant. It was observed that even for a simple, homogeneous, hypothetical catchment the simulated runoff results are significantly affected by the computational spatial size of the catchment used regardless of the type of model applied to the catchment.