ABSTRACT
The development process of a watershed is dynamic. Predictions of rainfall and runoff from a watershed rely on numerical modeling techniques that apply the concept of system to define the relationships among the rainfall as the input, the watershed as the throughput, and the outflow as the output. Hydrologic planning is a study to determine the design flows at the major design points based on the local climate and watershed information. An urban stormwater drainage system consists of the following components: watershed areas to generate storm runoff, waterways to collect runoff, detention facilities to store runoff, diversion facilities to transfer runoff out of the watershed, and inflow facilities to receive the runoff flows pumped into the watershed. Prediction techniques of stormwater hydrograph are generally classified into two major categories: unit hydrograph (UG) method and kinematic wave (KW) approach. The KW procedure requires the conversion of the real watershed into its virtual rectangle on the KW plane.
