發展綠屋頂水文模式與應用於減洪效用分析

Developing Green Roof Hydrological Model and Application in Stormwater Reduction Analysis

羅唯瑄(Wei-Hsuan Lo)

指導教授 ： 童慶斌

國立臺灣大學/生物資源暨農學院/生物環境系統工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.00465

摘要

面對都市化不透水鋪面逐年增加，以及氣候變遷下極端天氣衝擊，新興都市洪水管理以分散式系統取代傳統集中處理快速排除策略，綠屋頂是其中廣為推行、頗為有效的方案之一，然而相較於國外積極投入綠屋頂研究，以台灣氣候環境背景為主的綠屋頂水文研究卻顯不足，因此，本研究目的是發展以水平衡為架構的綠屋頂水文模式，並經過綠屋頂實驗觀測資料進行參數推估與模式驗證，透過觀測資料與模式應用探討綠屋頂的減洪效用，了解此模式作為洪水管理評估工具的服務能力。
本研究發展的綠屋頂水文模式NTU-GR (National Taiwan University— Hydrological Model for Green Roof)提供入滲或逕流優先計算的方法，模式參數推估可以分為透過實驗獲得的介質物理特性參數與反向推求的檢定參數兩類。以降雨事件進行模擬，驗證結果效率係數平均大於0.7，顯示本模式可以合理的預測綠屋頂的水文表現。觀測資料的減洪效用分析結果，大型降雨(總雨量大於20公厘)平均可以滯留體積、尖峰削減達到五成，尖峰延遲0~1小時。應用模式分析綠屋頂面對歷史颱風事件以及設計暴雨的減洪表現，結果顯示綠屋頂無法有效削減長延時、高強度類型降雨事件的尖峰流量，需要提高介質厚度或是搭配其他措施以協助洪水管理達到現有排水系統設計標準。本研究也初步探討綠屋頂承擔其它地區尖峰量達成整體減洪目標的能力，分析結果以額外承擔的綠屋頂面積大小倍數呈現，可以提供未來綠屋頂作為減洪措施的規劃設計參考之用。本研究發展綠屋頂水文模式應用於量化綠屋頂減洪能力，後續可以結合其它分散式雨水截流措施，完成整合社區尺度的洪水管理，加強都市面對洪水衝擊的調適能力。

關鍵字

綠屋頂 ； 實驗設計 ； 水文模式 ； 減洪措施 ； 模擬

並列摘要

As impervious area increasing due to the urbanization, along with the impact of the climate change, a new strategy for the urban stormwater management is the distributed system, instead of the traditional centralized treatment and the rapid drainage system. Green roofs are one of the widely-implemented and effective measures. However, compared to other countries’ considerable research on the green roof, the associated research based on Taiwan’s climate and environment is relatively insufficient. Therefore, the purpose of this study is developing the water-balance hydrological model for the green roof, acquiring parameters and validating the model through experimental data. Also, through the observation and model application, the stormwater reduction performance of the green roof is evaluated in order to assess the service it can provide in stormwater management.
The hydrological model for the green roof, NTU-GR, is introduced in this research, providing different priority calculation methods on the infiltration versus the runoff. The parameters used in this model can be divided into two categories; one is the physical characteristics of the medium, which can be obtained through the experiments, and the other comes from the calibration procedure. Based on the rainfall event, the model validation shows the average Nash coefficient is higher than 0.7, which implies the applicability of the model. According to the analysis of the observation data, green roofs can delay the peak for 0~1 hours, and retain 50% of total volume as well as peak value under the large rainfall events, which mean the total rainfall greater than 20 mm. Applying the model to appraise the green roof performance under the historic typhoon and design rainfall cases shows that green roof is not effective in terms of the long duration and high intensity rainfall event; in other words, it is necessary to increase the medium depth or cooperate with other measures to reach the limitation of the present drainage system. This study also preliminarily explores the ability of green roofs to take over other regions’ stormwater in expression of the additional green roof area so that it can achieve the overall stormwater reduction goal, thereby used as the planning and design tool in the future. In summary, this study develops the hydrological model and quantifies the green roof performance of the stormwater reduction. In the future, it is considered to combine with other distributed measures and incorporate into a community-scale stormwater management tool to enhance the adaptation of the stormwater impact in the urban.

並列關鍵字

Green Roof ； Experiment Design ； Hydrological Model ； Stormwater Reduction Measure ； Simulation

參考文獻

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