| Summary: | 碩士 === 國立臺灣海洋大學 === 河海工程學系 === 102 === Due to the rapid development of urbanization in Taiwan, there are some environmental problems have emerged, such as: increasing carbon dioxide, increasing impermeable pavement, flooding, and heat island effect. To solve those problems, the increasing green space should be the most effective way. However, the way was limited by high land price and few unused space. The low elevation green land is a new way to approach the land development that works with nature to manage stormwater. This technique can effectively decrease rainfall runoff by storage volume and infiltration.
The main purpose of this study is establishing the low elevation green land hydrological model based on infiltration, drainage, flooding and other drainage mechanisms. This model estimates rainfall intensity depth by Horner formula, calculates the effective rainfall volume by U.S. Soil Conservation Service, and design the outflow by Orifice Hydraulics. The simulation calculation program was written in Microsoft Office Excel. The variable factors of this model included: rainfall type, green land area ratio, green land depth, and drainage height. The major outputs are that low elevation green land rated base area. Using the model result, the peak flow decreasing amount was analyzed.
In this study, the rainfall was design by 90 minutes rainfall, return period: 2, 5, and 10 years of Taipei City. The major finding is that when low elevation green land rated 30% base area, low elevation green land depth is 0.4m, drainage height is 0.1m, and drainage diameter is 0.1m, the peak flow was decreased 100% volume.
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