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

本研究旨在建立坡面改良复垦地径流特征的定量评价方法。研究结果主要有以下几点：1.建立了一个集总径流模型KiWS模型（Runoff Model combined Kinematic Wave and Storage Tanks），用于洪水和枯水径流的连续分析.为解决集总KiWS模型和LST-Ⅱ模型（长短期径流模型）模拟洪峰流量及其出现时间的问题，在径流分析的降雨序列输入中引入延迟函数。根据流域模型坡长的分布特征和滞时方程，应用实用的汇流时间公式，对该函数进行了评价。并通过对增田吹填区的数据处理表明，存在的问题得到了改善.对忽略了河道径流计算的坡面径流简化模型进行了检验，并从流域模型集总的角度评价了其适用性。提出了有序流域模型中与贡献坡度h有关的最优模型参数的估算公式.指出所提出的径流模型和分析方法可以定量探讨退耕地坡面改良后径流特性的变化.本文用水文频率分析法对1988年7月15日在滨田发生的历史局部暴雨量的重现期进行了分析。

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.