城郊的熱通量模擬與量測

Abstract

可感熱通量為城市和城郊微氣候的重要控制因子。本論文為了研究垂直可感熱通量的傳輸，進行了城郊街谷的實地量測實驗和模式模擬。實驗地點位於台灣省台中縣清水鎮的一處高寬比(建築物高/道路寬)約為0.88的街谷，於該地點的谷內和屋頂上進行風速、空氣溫度、可感熱通量、表面溫度和淨輻射量的量測。 基於對街谷的高寬比和迴流區位置的瞭解，本文建立了兩個僅考量屋頂部分的一維模式以及兩個包含街谷整體的二維模式，來預測城市街谷的可感熱通量。研究結果顯示一維模式的預測值與實驗值最為相符。此外，街谷內的冠層可感熱通量約為屋頂上參考點的40%。

Sensible heat flux is a key parameter controlling the micrometeorology of the urban and suburban areas. In order to understanding the vertical transport of sensible heat fluxes, this study presented field measurements and estimations of the sensible heat fluxes over a suburban street canyon. The experimental site is located in a street canyon with an aspect ratio (Building Height/Road Width) of 0.88 in Taichung, Taiwan. Wind speed, air temperature, sensible heat flux, surface temperature, and net radiation were measured within and above the street canyon. By knowing the aspect ratio of the street canyon and the partition of recirculation region, two one-dimensional models of roof part and two two-dimensional models of street canyon were adopted for estimating sensible heat fluxes from the urban street canyon. Our results showed the one-dimensional modeled and observed sensible heat fluxes were in good agreement. The sensible heat flux at the canyon was almost 40% of that at the reference layer above the roof.