Technical Studies


Study on Guidelines and Modeling for Floodplain Delineation

The study, beside continuing the comparison work on hydrodynamic analysis and floodwater computation modeling established in year one, has been extended to cover applied assessment on additional analysis models. In hydrodynamic analysis, given that the retention function method which has worked well with assessing the Tamsui river and Chotsui Shih, it is prudent that varied hydrodynamic models, such as the boring model, retention function and topographical unit history modeling, be included to further enhance the practicality of said method of hydrodynamic analysis. Under which, an array of criteria, content and processes established in year one would be applied to assessing the Tung Kang Shih, complete with descriptive assessment. In hydrological computation, a pseudo two-dimensional floodwater model that closely represent the actual physical conditions is adopted for assessment purposes, made in conjunction with the river hydrodynamic modeling and flood-zone hydrological modeling. Meanwhile, the Geographic Information System (GIS) has been adopted not only to establish digitized topography data for digitizing the topography maps, but can also be used for sorting numeral topography data as key input data for the flooding model, i.e. the grid and parameter data of a given flood zone, allowing a final flooding map be produced by plotting in the simulation findings onto basic topography maps. This would allow computational analysis be conducted and a flooding parameter and depth of the probable flooding zone along a riverbank be established. Lastly a recapitulation summarizing the assessment findings concluded from the method and modeling adopted in the above mentioned hydrodynamic and hydrological analyses, together with study findings derived from pertinent data and auxiliary tools adopted for profiling and mapping a flooding zone, would facilitate subsequent criteria review and amendment work be implemented.