溪頭地區降雨強度特性之研究

Abstract

本研究蒐集台大實驗林溪頭營林區內較完整之苗圃雨量站1966∼1995年連續30年之雨量資料，以對數皮爾遜第三型分佈法分析不同回歸年之雨量。再利用1996∼2003年之小時雨量資料分析降雨強度式包括：物部式、Talbot式、Sherman式及Horner式等，探討各回歸年適用之不同參數變化情形。研究成果如下： 一、不同回歸年之物部式 n值會隨回歸年的增加而減少，溪頭地區之n值介於0.7∼0.35之間。 二、固定參數之降雨強度式在山區之適用性不佳。

The annual maximum daily rainfall data of the Nursery Rainfall Station in the Chi-Tou forest recreation area between 1966 and 1995 inclusive (thirty years in total) were made using the log Pearson Type III distribution method. We analyzed the rainfall intensity, based on the data for hourly rainfall from 1996 to 2003. The parameters were modified through a formula taking advantage of various types of equations for rainfall intensity, including Monobe formula, Talbot-type, Sherman-type and Horner-type during the different return periods. The findings are as follows: 1.The n value decreases as the return period increases if specific coefficient method to derive the n in the Monobe formula is used, and it is in the range of 0.35 to 0.7 in Chi-Tou area. 2.The equations for rainfall intensity with constant parameters are not suitable for use in the mountain areas.