General Hydrologic System Model

A lumped, deterministic, nonlinear mathematical model is developed and proposed for the simulation of hydrologic systems. The model is developed from expansion of a general storage function of input and output in Taylor's series about a steady state. The model recommended for practical application is based on the system model in the form of a third-order differential equation. It is a quasi-nonlinear model because the coefficients of the differential equation are considered as functions of the peak discharge of direct runoff. In the analysis of the model, watershed it taken as the hydrologic system. Nine watersheds with more than 70 major and minor storms were used in the analysis and verification of the recommended model. The results indicate a very satisfactory simulation of watershed hydrologic systems by the model.