Abstract
A runoff simulation system for large river basins is presented. A watershed basin is subdivided into grid boxes which corre-spond to the ones of numerical atmospheric models. The inputs to the system are hydrologic variables for grid boxes, which are assumed to be computed by numerical atmospheric models. Runoff from each grid box is calculated and routed along channel networks. The system is applied to the Chao Phraya River Basin. River discharges at many hydrological stations are simulated and model performances are evaluated.
