曾文溪上游地區1970年至2014年年一日最大雨量之頻率分析

Frequency Analysis of Annual 1-day Maximum Rainfall in the Upstream Drainage Area of Zeng-Wen River

沈少文(Shaw-Wen Sheen)

《作物、環境與生物資訊》 13卷1期 (2016/03) Pp. 1-12

https://doi.org/10.30061/CEB.201603_13(1).0001

摘要

本研究分析曾文溪上游地區馬頭山、里佳與水山等三雨量測站1970 至2014 年年一日最大雨量，使用Gumbel 分配計算來推測重現期距1.11 年至1,000 年年一日最大雨量，同時建立年一日最大雨量95%和99%信賴區間。研究發現，馬頭山雨量測站年一日最大雨量歷年平均數328 mm，中位數300mm，里佳雨量測站歷年平均數360 mm，中位數320 mm，水山雨量測站歷年平均數251mm，中位數234 mm。又當重現期距100 年時，馬頭山雨量測站年一日最大雨量851mm，為歷年年一日最大雨量平均數2.59 倍，里佳雨量測站年一日最大雨量1,081 mm，為歷年年一日最大雨量平均數3.00 倍，水山雨量測站年一日最大雨量684 mm，為歷年年一日最大雨量平均數2.72 倍。研究亦發現，馬頭山雨量測站平均100 年出現一次的年一日最大雨量有95%機率位於654 mm 與1,047mm 之間，里佳雨量測站平均100 年出現一次的年一日最大雨量有95%機率位於810mm 與1,352 mm 之間，水山雨量測站平均100 年出現一次的年一日最大雨量有95%機率位於521 mm 與846 mm 之間。根據本研究關於曾文溪馬頭山、里佳與水山雨量測站頻率分析結果，將可有助於了解曾文溪上游地區水文環境。

關鍵字

年一日最大雨量 ； 頻率分析 ； 重現期距 ； 曾文溪

並列摘要

The aim of this study is to analyze annual 1-day maximum rainfall recorded at Ma-Tou-Shan, Li-Jia, and Shui-Shan rainfall stations in the upstream drainage area of Zeng-Wen river in the period of 19702014. The Gumbel probability distribution statistics was adopted to estimate annual 1-day maximum rainfall with the return periods of 1.11 to 1,000 years. This study also estimated the confidence intervals (95% and 99%) for annual 1-day maximum rainfall. Results showed that the mean annual 1-day maximum rainfall was 328 mm with the median of 300 mm at Ma-Tou-Shan station. The mean and the median values of annual 1-day maximum rainfall were 360 mm and 320 mm, respectively, at Li-Jia station, while these values were 251 mm and 234 mm, respectively, at Shui-Shan station. The annual 1-day maximum rainfall was 851 mm with return period of 100 years at Ma-Tou-Shan station, ca. 2.59 times of the mean annual 1-day maximum rainfall. The value was 1,081 mm at Li-Jia station and was three times of the mean annual 1-day maximum rainfall. It was 684 mm at Shui-Shan station, ca. 2.72 times of the mean annual 1-day maximum rainfall. The 95% confidence intervals for annual 1-day maximum rainfall with return period of 100 years at Ma-Tou-Shan, Li-Jia, and Shui-Shan stations were 654-1,047, 810-1,352, and 521-846 mm, respectively. The experimental results may help further understand the hydrological environment in the upstream drainage area of Zeng-Wen river.

並列關鍵字

Annual one-day maximum rainfall ； Frequency analysis ； Return period ； Zen-Wen river