探討環境與地理因子對高齡化農村熱環境的影響: 以雲林縣為例

Abstract

近年來，在氣候變遷的影響下，極端高溫事件越來越頻繁地發生，使得人們面臨比以往更嚴峻的熱壓力。當人們長期暴露於高溫中，可能導致健康問題，特別像是經濟地位較低、老年人以及其他弱勢群體等更需要注意。除此之外，土地利用和覆蓋的變化（LULC）也會影響熱環境。雖然農村地區的土地利用變化相對都市較小，但非植被區域的擴張仍會影響該地區溫度的變化。為了瞭解農村地區年長者的熱壓力，並且降低暴露於高溫的風險，本研究的目標為分析在過去研究中較少被關注的農村地區熱環境和熱舒適。

本研究的研究樣區是雲林縣，雲林除了是一個重要的農業大縣之外，老年人口比例也相對較高。因此，為了找出雲林地區熱環境的時空特徵，首先分析了氣象參數（溫度、相對濕度、風速和平均輻射溫度）的空間分佈。接著，使用了生理等效溫度（physiological equivalent temperature, PET）作為熱舒適指標，用來分析農村地區老年人的熱舒適。並且，使用Python套件Pythermalcomfort進行PET和相關參數的計算。而土地利用與覆蓋的資料則是從衛星Landsat9的遙測資料進行監督式分類所獲取。

本研究首先分析了雲林地區年長者的熱舒適度和環境，並且揭示了幾個PET較高的熱點和時間點。另外，研究也顯示在農村地區土地利用對熱環境的影響為人造物和裸露地兩種土地利用與覆蓋的地表溫度較高。此外，在未來情境的熱舒適分析中，研究顯示年長者的不舒適(PET超過42°C)發生頻率有增加的趨勢。除此之外，本研究還試圖利用暴露度識別在不同情境下可能受到熱傷害的人群，以利相關政策擬定與資源分配。最後，研究總結相關單位所提出的一些熱傷害防治與相關建議，例如增加綠地、提供適當的遮蔭，以及在較涼爽的時間(4:00至7:00之間)進行體力活動等，提供相關單位參考。總之，本研究利用PET找出高齡農村地區在夏季時風險較高的時段和地區，期望可以提供熱風險預防參考的相關資訊。

In recent years, under the influence of climate changes, more and more extreme heat events have occurred and make people face more frequent heat stress than before. Moreover, long-term exposure to high temperatures may cause health issues, especially the people of low economic status, elderly and other vulnerable groups. In addition, changes in land use and land cover (LULC) also affect the thermal environment. Although land-use change in rural areas is relatively milder than that in urban areas, the expansion of non-vegetation areas still influences the variation of temperature in those areas. To quantify the heat stress and reduce the risk of long-term exposure to high temperatures of elderly in rural areas, the goal of this study is to analyze the spatial-temporal characteristics of the thermal environment and heat-related comfortability of aging rural areas, which have been rarely mentioned in the past research.

The study area of this research is Yunlin County, an important agricultural county with a relatively high degree of aging. To find the spatial-temporal characteristics of the thermal environment in Yunlin, the spatial distribution of meteorological parameters (temperature, relative humidity, wind velocity, and mean radiant temperature) were analyzed. Furthermore, to evaluate the effects of spatial characteristics on the human comfortability in this aging rural area, a thermal comfort index physiological equivalent temperature (PET) was utilized. In addition, the data of LULC is acquired from the remote sensing images with the supervised classification. The PET and the relevant parameters in the Yunlin area are calculated using the meteorological data of Yunlin and surrounding weather stations with the Python package, Pythermalcomfort.

This study first analyzed the thermal comfort and environment for the elderly in Yunlin, revealing several hotspots and time with high PET. The impact of land use on thermal conditions was also showed, with built-up and bare soil areas displaying higher temperatures. In addition, for the projection of future scenarios showed a trend of discomfort for the elderly is increasing, with a high frequency of PET exceeding 42°C. This study also tried to identify the individual who may be affected by the heat injuries under different scenarios by exposure analysis. Finally, some heat preventions and suggestions were summarized, increasing greenery, ensuring suitable shading, seeking cooler spaces on hot days, and scheduling physically demanding activities during cooler hours (between 4:00 and 7:00), etc.. In conclusion, this study utilized PET to identify high-risk periods and locations for aging rural areas in Yunlin during the summer, with the goal of providing valuable information of heat risks.