COMPUTATIONAL DISCRETIZATION EFFECT ON RAINFALL-RUNOFF SIMULATION

Modeling catchment runoff require spatial discretization of the catchm ent 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, a n Australian nonlinear conceptual model (RORB), and a physical-process -based distributed model (HEC-1) were tested by applying them to a hyp othetical catchment. For each model the spatial discretization size fo r computations was systematically decreased, while all other catchment and model parameters were held constant. It was observed that even fo r a simple, homogeneous, hypothetical catchment the simulated runoff r esults are significantly affected by the computational spatial size of the catchment used regardless of the type of model applied to the cat chment.