下水道系統入流方式與進水口堵塞效應對都會區淹水模擬之影響

Pluvial Flooding Modelling in Urban Areas: The Roles of Storm Sewer Inlet Type and Inlet Clogging Effect

郭哲豪(Che-Hao Kuo)

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(2019年)

https://doi.org/10.6342/NTU201903734

摘要

當降雨發生於都會區時，需藉由雨水下水道系統將地表逕流排至河川或海域以避免積淹水災情發生，然而近年來氣候變遷及極端氣候影響之下，若下水道系統因強降雨導致垃圾及落葉堆積於側溝之格柵進水口造成堵塞之情況，則使水流無法順暢進入下水道系統，進而增加都會區積淹水事件發生機率。
本研究為探討不同雨水入流下水道系統方式及進水口堵塞對都會區淹水模擬之影響，先比較雨水由人孔與側溝進水口入流之差異，分析何種入流方式於模擬中有較佳之表現，從結果中發現以進水口方式較佳但仍有誤差，故再以進水口入流方式考量0%~100%堵塞情況，並考量全區進水口皆堵塞及僅相鄰路樹進水口之部分堵塞情境，分析進水口無堵塞、進水口皆堵塞及僅相鄰路樹進水口之部分堵塞三種情境之淹水情況，藉由準確度、偵測率、精確度及預兆得分和雨水下水道水位進行分析探討，以探討何種雨水入流方式與堵塞情境有較佳表現。
本研究以臺北市文山區木柵次分區作為研究區域，並透過兩場歷史事件進行評估，其結果顯示以進水口入流無論是在地表淹水範圍或下水道水位皆較貼近調查情況，而部分堵塞情境在堵塞係數20%時能使模擬結果較無堵塞更接近實際淹水調查之情形，因此進行都會區淹水模擬時，應多加考量進水口以及鄰路樹部分堵塞的情況。

關鍵字

都會區快速淹水模式 ； 交互演算 ； 堵塞因子 ； 格柵進水口 ； 雨水下水道

並列摘要

In recent years, the effects of climate change and extreme weather have caused more and more rainfall intensity, more and more flooding events, and the increased rainfall intensity to move the garbage and leaves on roads. If the garbage and fallen leaves block road drains, it will increase the probability of urban flooding events.
This study analyzes urban flooding simulations with various methods of coupling one sewer flow model and one overland flow model. The runoff enters the sewer system by manholes and road drains respectively. The flooding simulation results show that the road drainage method has better evaluation results. However, there are still some errors compared with the observation data. Therefore, this study considers the blockage of road drains and sets the 0% to 100% clogging factors as the set value with reference to relevant literature.
This study uses three kinds of road drain clogging scenarios for urban flooding simulation. 1. All road drains are not clogged, 2. All road drains are clogged, 3. road drains around road trees are clogged. And use Accuracy(ACC), Probability of Detection(POD), Precision or Predictive(PPV), Threat Score(TS) and the water level at the WL gauge to analyze which clogging scenarios have better urban flooding simulation results.
In this study, the Muzha sub-catchment area of Wenshan District in Taipei City is selected as the research area. Two historical flooding events are used to evaluate the above scenarios. The best flooding simulation result is this scenario in 20% clogging factor of road drains around road trees.

並列關鍵字

2D Rapid flood model ； Dynamic flow interaction ； Clogging factor ； Grate inlet ； Storm sewer flow

參考文獻

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