應用設計雨型歷線推估中寮溪集水區暴雨流量歷線

Application of Design Hyetographs to Estimate Stormflow Hydrographs of Chungliaoshi Watershed

10.29995/JSHR.200606.0001

盧惠生(Hui-Sheng Lu)；林壯沛(Jaung-Pey Lin)；黃良鑫(Liang-Shin Hwang)；林介龍(Chieh-Lung Lin)

設計雨型歷線 ； 暴雨流量歷線 ； 中寮溪集水區 ； Design Hyetograph ； Stormflow Hydrograph ； Chungliaoshi Watershed

坡地防災學報

5卷1期（2006 / 06 / 01）

1 - 14

繁體中文

本文以林業試驗所六龜試驗林的中寮溪集水區暴雨流量資料，建立SCS逕流曲線指數法之CN值，獲得中寮溪集水區CN值爲70。再以中寮溪集水區降雨－延時－頻率推估式，採用美國土壤保育局之逕流曲線指數法，推估超滲雨量，同時以三角單位歷線法及24小時設計雨型歷線推估式，推估不同頻率年暴雨流量歷線。根據推估之暴雨流量歷線，獲悉中寮溪集水區頻率年：1、2.33、5、10、20、25、50、100年；暴雨量：307.3mm、360.9mm、417.2mm、475.9mm、542.9mm、566.4mm、646.2mm、737.1mm；暴雨流量：206.7mm、256.7mm、310.1mm、366.3mm、431.8mm、453.9mm、531.7mm、620.9mm；洪峰流量：5.7cms/km2、7.0cms/km2、8.3cms/km2、9.7cms/km2、11.3cms/km2、11.8cms/km2、13.7cms/km2、15.8cms/km2。當集水區CN值確定時，影響SCS逕流曲線指數法推估暴雨流量歷線的重要參數爲坡面逕流流速。坡面流速在10cm/sec以下，坡面逕流流速增加，集流時間減小速度甚快，洪峰流量增加速度亦甚快。

The curve number of Chungliaoshi watershed at Liouquei experimental forest of Taiwan Forest Research Institute was 70 from analysis of measured stormflow data. The rainfall excess from 24-hour rainfall of different recurrence years in Chungliaoshi watershed was calculated by SCS curve number method. Then, the stormflow hydrographs of Chungliaoshi watershed were estimated with triangular unit hydrograph method and design hyetograph estimated equations. As recurrence years were 1, 2.33, 5, 10, 20, 25, 50, 100 years, storm rainfall were 307.3mm, 360.9mm, 417.2mm, 475.9mm, 542.9mm, 566.4mm, 646.2mm, 737.1mm, and stormflows were 206.7mm, 256.7mm, 310.1mm, 366.3mm, 431.8mm, 453.9mm, 531.7mm, 620.9mm, as well as peak flows were 5.7cms/km2, 7.0cms/km2, 8.3cms/km2, 9.7cms/km2, 11.3cms/km2, 11.8cms/km2, 13.7cms/km2, 15.8cms/km2. When curve number had unique number, runoff velocity was the important parameter of SCS curve number method to estimate stormflow hydrograph. Based on the sensitivity analysis, time of concentration decreased faster and peak flow increased quicker as runoff velocity less than 10cm/sec on hillslope increased.