現今有超過半數以上的人居住在都市化之地區，加上受到極端氣候之影響、人口群聚效益之結果，導致都會區之各類型產業活動和都市基礎設施建設更容易受到衝擊，災害風險提高。因此如何減輕都市化地區受極端氣候之影響，降低淹水風險、減少潛勢地區的脆弱度，建構一個適應災害環境，且與災害共存之城市，是一個非常重要之議題。目前研究尚缺乏去探討地表逕流與都市下水道工程之間所衍生的衝擊與影響，再經由模擬研究範圍之水環境特性，探討不同降雨型式下，研究範圍在設置低衝擊開發設施設置前後對逕流量之削減效率，並以海綿城市之概念，檢視是否達到減少下游衝擊之目標。
本研究利用都市暴雨逕流管理模式（Storm Water Management Model, SWMM）模擬短延時豪雨（事件一）和尖峰豪雨（事件二），因強降雨所產生之地表逕流，期望透過改變地區基礎設施及引入低衝擊開發的概念，來降低極端氣候所帶來之衝擊與影響。本研究以林口新市鎮為例，分別在事件一、事件二設置低衝擊開發設施，研究顯示洪峰削減率為61.51%與62.31%。綜合上述模擬結果，設置低衝擊開發設施可有效降低地表逕流，達到逕流削減、改善淹水問題等目標與效益
More than half of the population now lives in urbanized areas. As a result of the effects of extreme climate and the benefits of population clustering, all kind of industrial activities and urban infrastructure in urbanized areas are easier to be impacted and rising disaster risks. Therefore, it’s a very important issue that how to reduce the effects of extreme climate in urbanized areas, lowering flooding risk, decreasing the vulnerability of potential areas and construct a city which can adapt to the environment of disaster and coexist with it. The research currently still lacks discussing impact and influence which between the surface runoff and city sewer engineering. Through the simulation of the scope of the water environment characteristics and different rainfall types, research scope in the setting of facilities of low impacted development sets up runoff in cutting efficiency. It’s the concept of integrated flow management to examine whether to achieve target that reducing downstream impact.
The research simulate short-delay heavy rain （Event1） and peak heavy rain （Event2） by Storm Water Management Model, SWMM. Because of surface runoff by downpour, it expects to reduce influence of extreme climate by changing regional infrastructure and introducing the concept of Low-Impact Development. This study takes Linkou New Town in New Taipei City for example. It sets up Low-Impact Development facilities in Event 1 and Event 2 respectively. It demonstrates that reduction rate of flood peak are 61.51% and 62.31%. As shown above the simulation results, there are goals and benefit by setting up Low-Impact Development facilities can efficiently reduce surface runoff, achieve surface reduction and improve flooding problems.
