Change of Flood Runoff form for Long Term and Run-off Model Parameters in Reclamation Area

本研究旨在建立改良坡面复垦土地径流特征的定量评价方法。主要研究成果如下：1.建立了集总径流模型--KIWS模型(运动波与蓄水池相结合的径流模型)，用于洪水和枯水径流的分析。在径流分析的降雨序列输入中引入延迟函数，解决了集总径流模型和LST-II模型(长短期径流模型)模拟的洪峰流量及其出现时间的问题。根据流域模型中坡长的分布特征，应用集结时间的实用公式，建立了滞后时间方程，对该函数进行了评价。并通过对松田垦区数据的处理表明，这些问题得到了改善。省略了简化的坡面流型径流模型，对渠道径流计算进行了检验，并结合集总流域模型对模型的适用性进行了评价。并针对有序流域模型中的贡献坡长h，提出了最优模型参数的估计公式。提出的径流模型和分析方法为定量探讨改良坡耕地径流特征的变化提供了可能。利用水文频率分析方法，对滨田1988年7月15日历史局地暴雨的重现期进行了估算。

This study aims to establish the quantitative evaluation method of runoff characteristics in reclamation land at improved slope. Main points of the study results are as follows :1. A lumped runoff model named KiWS Model (Runoff Model combined Kinematic Wave and Storage Tanks) is developed for analyzing both flood and low water run-off successively.2. A delayed function is introduced to input rainfall sequence of runoff analysis for dissolution of the problems on peak discharge and its occurrence time simulated by the lumped KiWS model and LST-II model (Long and short terms runoff model). The function is evaluated from the distribution characteristics of slope length in a basin model and the equation of lag time applied the practical formula for the concentration time. And it is showed by dealing with the date in MASUDA Reclamation basin that the problems are improved.3. Simplified runoff model of overland flow type omitted the calculation of channel flow is examined and the applicability is evaluated in relation of lumping the watershed model. And the estimating formulae for optimum model parameters have been proposed in relation to the contributing slope lengt h in the ordered watershed model.4. It is pointed out that the quantitative discussion on change of runoff characteristics in reclamation land at improved slope is possible by the proposed runoff model and analytical method.5. The return period for the amount of historical localized heavy rainfall at HAMADA in July 15, 1988 is evaluated by a hydrologic frequency analysis.