防水閘門設置對都會區排水及淹水改善之效益評估

Floodgates Effectiveness on the Improvement of Drainage and Inundation in Urban Areas

王嘉瑜(Jia-Yu Wang)

指導教授 ： 張倉榮

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(2017年)

https://doi.org/10.6342/NTU201704480

摘要

隨著經濟發展，都會區的建物和不透水鋪面積不斷增加，在其遭遇短延時暴雨或颱風等強降雨事件時愈來愈容易發生積淹水情況，造成生命財產的損失。為降低都會區的淹水損失，政府已立法規定建築物的出入口處須設置防水閘門。由於建築物出入口的位置和大小不盡相同，需針對每出入口設置特定尺寸的防水閘門，因此本研究改在道路邊緣設置防水閘門，結合以道路作為暫時性排水系統的概念，來降低都會區的淹水損失。
本研究為探討防水閘門對都會區之淹水改善效益，選擇全區域及重點區兩種防水閘門設置方式與60、90、120公分三種防水閘門設置高度，將其組合成六種防水閘門設置策略。以降雨情境進行淹水模擬，結合超越機率的概念，計算出各策略下都會區淹水的年平均損失及年平均效益。最終，以益本比評估出本研究區域的最佳防水閘門設置策略。
本研究以臺北市文山區木柵次分區作為研究區域，六種防水閘門設置策略的效益分析結果顯示：在相同設置高度下，防水閘門設置方式以重點區設置方式的年平均效益較好；而相同設置方式下，防水閘門設置高度皆以高度120公分的年平均效益較好。益本比分析結果，以重點區設置方式較具經濟可行性，且以防水閘門設置高度90公分是本研究區域的最佳設置策略；而全區域設置方式在任何高度下皆不具經濟可行性。

關鍵字

防水閘門 ； 效益分析

並列摘要

With the development of the social economy, the building and impervious paving in urban are dramatically increased. However, in recent years short duration rain and typhoon events frequently occur in urban area, which rainfall is more than the drainage capacity of storm sewer systems. Therefore, flooding in urban areas has been occurring more and brings damage to the public and the economy on various aspect. In order to reduce losses, the government has stipulated that the entrance and exit of the building must sets floodgates. Because the size and position of buildings’ gateways are different, we must set the specific size of floodgates for buildings’ gateways. Therefore, we use the idea which street as a short drain system, we can set floodgates at the edge of street to reduce losses.
The study explores that floodgates effects on the improvement of drainage and inundation in urban areas. Therefore, the study selected two floodgates set modes, which are full set mode and partial set mode and three floodgates set heights, which are 60, 90, 120 centimeters. Two floodgates set modes and three floodgates heights combined into six kinds of floodgates set strategy. Six floodgates set strategies and return periods rainfalls are inputted into flood model to simulate. Next, annual loss, annual benefit of the strategies were calculated by flooding loss and probability of excess. Finally, we used the annual average loss, annual average benefit and benefit ratio to evaluate what kind of set strategies is the best economic feasibility of set strategy in the study area.
In the study, Muzha drainage basin in Wenshan District, Taipei, is selected as the study area. In same height, the annual average benefit of partial set mode is better. In same set mode, the annual average benefit of floodgates set height 120 centimeters is better. The result of benefit-cost ratio analysis is that the partial set mode with set height 90 centimeters means the best economic feasibility of set strategy, and the full set mode with any set height is not economic feasibility.

並列關鍵字

Floodgates ； Benefit Analysis

參考文獻

45. 梁益詮，2016年，都會區街道與雨水下水道水流互動之快速淹水模擬，國立臺灣大學生物環境系統工程學系碩士論文。

31. 廖烜欣，2009年，街道與雨水下水道淹排水模式之研究，國立成功大學水利及海洋工程研究所碩士論文。

44. 陳冠文，2015年，不同雨水下水道人孔入流模擬方法對都會區地表淹水與下水道水理之比較，國立臺灣大學生物環境系統工程學系碩士論文。

43. 王嘉和，2015年，新一代都會區地表與雨水下水道水流互動之淹水模擬，國立臺灣大學生物環境系統工程學系博士論文。

24. 糠瑞林，2005年，區域淹水風險評估及其未確定性分析，國立臺灣大學生物環境系統工程學系博士論文。