Author(s): Chintu Lai; Ting-Kuei Tsay; Chen-Ho Chien; Chih-Hung Tan; I-Ling Wu; Nan-Ching Wu; Chi-Yao Lin
Linked Author(s): Chintu Lai
Keywords: Realtime simulation; Flood forecasting; Modeling and simulation; River basin; ; Dynamic hydrology; Data/Modeling integration; Unsteady-flow modeling; Computer graphics; Combined simulation of flood and tidal flow; Warning system of extremes; GIS application in modeling
Abstract: An effort to develop and implement an effective, realtime flood-forecast model system, with specific applications to the Tamsui River basin as its immediate objective, was undertaken by the NTU Hydroinformatic R&D Group. The Tamsui River system is a life artery of the Greater Metropolitan Taipei area, which has been repeatedly afflicted by floods of extraordinary magnitudes. First, a deterministic, comprehensive, basin-wide unsteady river- flow model has been successfully developed. In addition to building a general numerical simulation model, the work has also included the aspects of, effecting realtime/forecast simulation, enhancing automatic model handling, extending modeling scope and capability, improving flow-resistance coefficient calibration techniques, and refining the over-bank flow evaluation process. The present model affords fairly reasonable and dependable stage prediction for several forecast hours, which can be extended by a few special techniques, including stochastics- and physics-based methods and eye-judgment means. For upstream boundaries, a rainfall-stage model has been developed to obtain the boundary-stage data from the rainfall data further upland. This further upland point can, in turn, be linked to another, called typhoon-rainfall, model, for yet another extension, to as much as 24 hour flood forecasting. At the river-mouth boundary, a physics-based model gives accurate prediction of the astronomical tides, to which a storm surge could be added if needed. The river channel flood-stage forecast model can be enhanced by addition of a GIS-based flood-inundation zone estimation model. When the flood water begins flowing over to the surrounding area, the former evaluates the total volume of the effluent from the lateral outflow, the latter then converts this volume into the corresponding inundated area. As the last stage of the system development, all the component models of the system must be well integrated, and the integrated system must be properly implemented. To this end, several desirable and helpful model features have been designed and effected, such as the friendly I/O interface, an easily operable and reliable hydrological data base, and the multiple-use access to such a base. 3224 September 11~16, 2005, Seoul, Korea
Year: 2005