雨型與入滲對運動波漫地流之影響分析研究

Abstract

本研究利用一維運動波理論及Green-Ampt入滲理論，探討雨型與入滲對漫地流之影響。研究中，考慮入滲作用下，首先分析降雨時間分佈分別為均勻型、後退型、前進型及中央型對漫地流之影響，再進一步將四種雨型應用於降雨空間分佈，分析移動暴雨產生之時空變化降雨對漫地流之影響。結果顯示，雨型與入滲影響運動波漫地流甚鉅。不同雨型所產生之最大流量，以後退型為最大，中央型次之，均勻型最小。最大流量之發生時間，則以前進型最早，後退型最晚。此外，入滲作用不但會減少最大流量，亦可能改變逕流歷線型態。

In this study, based on one-dimensional kinematic wave overland flow theory and Green-Ampt infiltration theory, the effects of rainfall patterns and infiltration on overland flow are examined. First, four hypothetical rainfall patterns, including uniform, delayed, advanced, and intermediate rainfall patterns, in temporal distribution are used to conduct this examination. The moving storm with different rainfall patterns in spatial distribution is then applied to further investigations. The results show that the overland flow is significantly related to the rainfall patterns and infiltration. The delayed rainfall pattern produces larger peak discharge with the latest occurrence than the other three ones. The peak discharge of the uniform rainfall pattern is largely underestimated as compared with the other three rainfall patterns. For the advanced rainfall pattern, the time to peak discharge is shorter than those of the others. In addition, the infiltration could not only decrease the discharge but also affect the runoff pattern of overland flow.