集水區降雨逕流歷程之連續性模擬

Continuous Simulations for Watershed Rainfall-runoff Processes

李光敦(Kwan-Tun Lee) ； 洪夢秋(Meng-Chiu Hung) ； 林怡廷(Yi-Ting Lin) ； 張進鑫(Chin-Hsin Chang)

《農業工程學報》 52卷2期 (2006/06) Pp. 12-22

https://doi.org/10.29974/JTAE.200606.0002

摘要

傳統水文模式均祇分別針對長期距流量或是短期距流量進行模擬，因此長期距模式無法模擬颱洪暴雨期間流量急遽上升之現象，而短期距模式則無法模擬地下水流從土壤含水層緩慢釋出之情形。故本研究建立連續型逕流模式，結合地形指數模式與運動波－地貌瞬時單位歷線模式，以進行日流量模擬與小時流量模擬。研究中並由累積雨量制訂出模式串接標準，銜接日流量模式與小時流量模式，以進行集水區降雨逕流歷程之連續性模擬。因此在無降雨或低降雨強度情況下，可藉由日流量模式模擬集水區地下水流的退水過程；而於高強度集中降雨之颱洪時期，則可藉由小時流量模式掌握洪峰流量及尖峰到達時刻。因此本研究所建立之連續型逕流模擬方式，可適切反應出長期距與短期距之集水區逕流現象。
本研究以橫溪集水區為例，利用數值高程模式求得地形指數模式及運動波－地貌瞬時單位歷線模式中所需之地文因子，以進行日流量及颱洪流量之模擬。研究中並配合地理資訊系統ArcView GIS應用軟體，建立集水區地文與水文資訊查詢系統，將模式操作轉換為視窗化介面，使用者僅須以滑鼠點選集水區河川網路上任一位置點，即可進行該指定位置點以上地文因子之查詢，以及集水區之長、短期距的降雨逕流演算。

關鍵字

連續性逕流模擬 ； 地形指數模式 ； 運動波－地貌瞬時單位歷線模式 ； 地理資訊系統 ； 日流量模式 ； 小時流量模式

並列摘要

Conventional hydrologic models are usually only applied to long-term or short-term runoff simulations. Consequently, the long-term runoff model cannot adequately simulate the rapid rising discharge during typhoons, and the short-term runoff model cannot well simulate the runoff slow flowing out of the subsurface stratum. The TOPMODEL and the kinematic-wave based geomorphic IUH model were developed for daily flow and storm runoff simulations, respectively. A criterion was developed with cumulated rainfall to link these two models to form a continuous runoff simulations. The daily runoff model can well simulate the recession process of groundwater during no/low rainfall. While applying hourly simulation model, especially for the predictions of storm peak flow and time to peak, a better performance can be found in hourly-flow simulations. Therefore, the runoff situations of daily flow and storm runoff can be both reflected adequately with the continuous runoff simulations.
The Heng-Chi watershed is adopted for applying the TOPMODEL and the KW-GIUH model for long/short terms runoff simulations. The geomorphic parameters of the watershed were calculated by using a digital elevation model. The continuous runoff simulations were embedded into an ArcView GIS platform to form a geomorphic- hydrologic inquiry system for practical applications. The operation of runoff modeling was then transferred onto a convenient Windows based interface. When using the inquiry system, users can interactively select a location for a subwatershed outlet by simply clicking on the desired point within the watershed stream network, and then the geomorphic factors and runoff calculations can be performed.

並列關鍵字

Continuous runoff simulations ； TOPMODEL ； Kinematic-wave based geomorphic IUH model ； Geographic information system ； Daily flow model ； Storm event model