人口大量且快速的向生活機能完善的大都市集中，造成都市密度不斷提高，導致高溫化，使得都市的溫度比四周的郊區還來的高，就如同一座熱島，形成了都市的「熱島效應」。根據研究指出熱島效應的產生主要原因之一為都市設計規劃時未有周詳的環境考量，故改善對策之一應針對建成區域之建築與景觀配置進行探討，包括擴大都市綠地或增加植栽數量，在都市微氣候的相關研究中指出，「綠覆率」的提升可改善都市熱環境，都市熱島效應的解析證明，綠地確實可降低環境溫度，且植栽的配置也會對氣流產生影響。因此，延續97、98年度之研究計畫，本計畫將針對植栽、透水鋪面及其他材料鋪面，探討其蒸發散作用對都市降溫以減緩都市熱島效應之研究，本研究分兩年度進行，第一年度主要以實際測量、建立微氣候資料庫、建構數值模型、並進行實驗量測數據與數值模擬驗證。第二年度針對不同變數(街道走向、植栽、透水鋪面)進行模擬、比較與分析。藉由微氣候資料庫及數值模擬，分析不同街道尺度對都市微氣候之影響，並以標準有效溫度(SET)評估戶外空間舒適度，進而透過數值模擬，以無因次圖表分析不同植栽類型及鋪面材料對減緩都市熱島之效益，並提出減緩都市熱島效應之因應改善策略。
Due to the rapid increase of population in city areas, the phenomena increase the density of city and result in heat island effect. According to the previous investigations, one of the reasons for the heat island effect is the neglect of environmental aspects during the planning stages. Thus, one of the improving strategies is to study the layouts of architecture and landscape in built environment including expansion of green areas and increase of planting numbers. Many of research relating to urban climate indicate that the increase of green coverage ratio can improve the quality of thermal environment. In the analyses of urban heat island, it shows that greening area can be useful to reduce the environmental temperature and the arrangements of greening can drive the air flow. Therefore, continuing the research funded by NSC in 2008 and 2009, the current study will study the evaporation effects of planting, pervious and other pavements on the mitigation of heat island effect. The research will be divided into two years. The first year will include 3 parts of the whole study including carrying on the field measurement, building the database of micro-climate, and verifying the CFD model by the comparisons with experimental data. The second year will continue the woks by parameter study including street directions, planting layouts and pavement types by means of CFD study. Through the analyses of micro-climate database and numerical study, the study aims at finding the effects of each parameter on the micro-climate and the comfort level of outdoor spaces by SET. The study will also condense the data into nondimensional graphs which can be used to understand the detailed information of each parameter on mitigating heat island effect. Finally, the improving strategies for the mitigating heat island effect will be given based on the 2 years works.
