Spatially distributed modeling of stream flow during storm events

The purpose of this paper is to present a new approach for the spatially di stributed modeling of water flow during storm events. Distributed modeling of flow during storm events is an important basis for any environmental mod eling, including turbidity or sediment transport. During the initial phase of a rainstorm, surface runoff is the main contributor of flow. To provide the spatial components for distributed hydrological modeling a Geographic I nformation System (GIS) was used to map and visualize contributing areas ar ound a stream channel. Stream segments were defined using the hydrologic re sponse unit (HRU) concept. Lateral flows were derived from GIS output for e ach segment of the stream and at each time interval of the rain storm and w ere routed using the kinematic routing equation. This approach is new in hy drological modeling and can be used to enhance many existing simulations. T he model is also unique in the fine time scale (i.e., intervals are on the order of minutes). Model results showed good correlation with measured disc harge values; however, further studies of contributing area behavior, its r elationship with soil types and slope categories, and the influence of wate rshed size are needed to improve model performance. This model will be used in the future as the basis to model turbidity in streams.