| 摘要: | 淺處(<20m)的垂直井溫可能受到季節的影響，一天的量測並不有代表性，表層土壤溫度(surface soil temperature簡稱SST)則變化更大，且有地理上及時間上的差異。SST為瞭解地下熱傳的重要邊界條件，本研究之目的，希望實地量測嘉南地區的SST並探討其與土地利用之關係。研究結果顯示可將埋設溫度計的土地分為四類:建築、樹林、草地及裸土(含舖面)， 本區2017年實測SST比氣溫高(本區年均溫約23.9-25.2 °C)，所以除了受到氣溫影響，也受到日照影響；有陰影遮蔽，例如樹林及建築物，SST約為23.8-26.2 °C，會比較接近氣溫；沒有遮蔽，例如裸土溫度約26.0-28.3 °C，因為直接日曬會造成SST升高。 垂直井溫推估現在的SST，其值大約介於24.5-28.5 ℃。將觀測井半徑100m內的土地利用分為五類:樹林、建物、旱地(作物及草地)、空地(裸土、道路及操場)、魚塭(靜止水體)，統計其面積的百分比，求取最接近的井溫之現在SST，結果樹林25.6 ℃、建物25.9 ℃、旱地25.2 ℃、空地27.6 ℃、魚塭26.8 ℃，平均誤差約0.51℃。以面積推算之SST與2015年垂直井溫推算之現在SST比較大致上有正比關係，本研究數據支持井溫受到土地利用之影響。
For the purposes of hot spring and Surface Soil Temperature (SST or Ground Surface Temperature-GST) is defined as the surface or near-surface temperature of the ground (soil, bedrock, or surficial deposit, measured in the uppermost centimeters of the ground. SST is the temperature in the upper boundary of subsurface temperature-depth curve which is an important parameter for the understanding of the subsurface heat transfer and climate. In this research, temperature data loggers were setup for collecting SST on the Chianan plain to study the correlation between SST and different land covers. The results show that study sites of Chianan plain include 4 types of land cove: building, trees, grass and bare soil. The values of SST in 2017 are 23.8-28.3 °C while the average annual air temperature are 23.9-25.2 °C. The temperatures for trees and building are lower, 23.8-26.2 °C while those temperatures are higher in bare soil 26.0-28.3 °C, with no shadow to shield the solar radiation. The present SST from temperature-depth curve in Chianan plain are 24.5-28.5 ℃. The land covers around the observation well with a radius of 100 m include 5 types: trees, building, crop(grass), bare soil(pavement), and fish pond. The present SST values are correlated with percentages of land cover area to estimate the temperature in different land covers. The best fitting temperatures are 25.6, 25.9, 25.2, 27.6, and 26.8 ℃ for trees, building, crop, bare soil, fish pond, respectively, with an average error of 0.5 ℃. The present SST from temperature-depth curve and the SST estimated by land cover area show a positive correlation which indicate the upper boundary of temperature-depth curves are affected by land covers. |
