臺北都市化對溫度、雨量與GPS可降水量之影響

Impact of Taipei urbanization on temperature, rainfall and precipitable water vapor from GPS signal

蘇冠臻(Kuan-Chan Su) ； 葉大綱(Ta-Kang Yeh) ； 詹士樑(Shih-Liang Chan) ； 洪景山(Jing-Shan Hong)

《大氣科學》 47卷2期 (2019/06) Pp. 203-227

https://doi.org/10.3966/025400022019064702004

摘要

臺灣在都市高度發展下，高溫於市區集中，產生都市熱島，也使降雨量與雨帶分佈產生變化。GPS氣象學（GPS Meteorology, GPSMet）利用GPS長久發展歷史與高精度訊號，反演出大氣可降水量（Precipitable Water Vapor, PWV），其為產生降雨的先期指標，而溫度變化為影響大氣可降水量高低之因子。故本次研究大臺北地區在都市化影響下，2006年至2015年之夏冬季溫度、大氣可降水與降雨量現象與變化。結果顯示大臺北地區確實存在熱島效應，十年中夏季熱島強度最高達到1.2℃，冬季達到0.8℃，夏季熱島現象較明顯。而大臺北地區十年溫度趨勢夏冬季表現不一，夏季十年間約升溫0.8℃，而冬季大部分區域有低溫趨勢，2006年至2015年約降溫0.5℃。冷熱區十年間皆有擴大現象，熱島強度也隨時間增加。大氣可降水十年內有增加趨勢，約8.8 mm，而暖化與熱島作用影響下，大氣可降水在夏季和市區有較高表現，且十年中在市區有較高增加量。降雨量在可降水整體增加下，夏冬季無論在市郊區也整體增加約50.9 mm，且雨量乾溼區差距隨時間進一步加大。溫度、大氣可降水與降雨量彼此相關係數達0.3以上，而大氣可降水與降雨量相關性呈中度以上相關。面對未來都市地區因氣候變遷造成更多熱浪與水患之可能，施政者需加強留意規劃防、減災軟硬體設施，避免造成無法彌補之災害。

關鍵字

GPS氣象學 ； 可降水量 ； 熱島效應 ； 全球暖化

並列摘要

In the process of urbanization in Taiwan, the high temperature in the urban areas has lead to heat island, which changes the rainfall strengths and raining zones. By the high development of GPS system, Precipitable Water Vapor (PWV) can be calculated from the GPS signals. PWV is the early indicator of the rainfall, and affected by the level of the temperature. Therefore, the purpose of this study is to investigate the performance of three orientations - temperature, PWV and rainfall. The above parameters are divided into summer and winter, to obtain the influence of urbanization in Taipei from 2006 to 2015. The results showed that there surely has heat island in Taipei. The phenomenon performed much obvious in summer than that in winter. The former reached 1.2℃ and the latter reached only 0.8℃. Nonetheless, the warming phenomenon reflected differently in summer and winter. The former's temperature rose 0.8℃ and the latter dropped about 0.5℃. Not only the hot and cold area expanded within ten years, the heat island but also increased as time goes on. The PWV increased within ten years reached about 8.8 mm. Under the influence of heat island and global warming, the PWV performed evidently in summer. With the increments of the PWV, despite the weather and the areas, the rainfall increased 50.9 mm overall. The wet and dry areas also expanded along the time. The correlation coefficient of the temperature, PWV and rainfall achieved larger than 0.3. The correlation coefficient between the PWV and rainfall was even clearer. To face the heatwave and flooding caused by the climatic change in the future, the government needs to pay more attention on disaster prevention, avoid causing irreparable mistakes and damages.

並列關鍵字

GPS Meteorology ； precipitable water vapor ； heat island effect ； global warming