Application of Stochastic System Theory for Rainfall Runoff Analysis

通过流域储水量非线性关系的时空变化参数的变化，对山地小流域的洪水径流过程进行了研究。采用随机系统理论对参数进行辨识。研究结果总结如下：1。利用随机系统理论，将参数论证应用于状态空间的表述。时变蓄水参数的变化与以沟流为代表的山坡上快速水流的产生密切相关，通过识别其变化可以反比估计平均水流压力。本文介绍了一种模型，在该模型中，储水量Sc用于连接通流为主和快流（以沟流为代表）为主时流域储水量与流量之间的关系。结果表明，仅用降雨和流量数据进行非线性滤波即可估计出Sc。并给出了用Sc识别参数的方法。澄清径流模型参数的空间变化对集总问题具有重要意义。

Studies are made on flood runoff processes in small mountainous basin through variation in timespace-varying parameters of the nonlinear relationship between basin storage and dischage. An identification method of the parameters is used by the stochastic system theory.The results are summarized as follows:1. Parameter argumentation is utilized in state space formulation by using stochashic system theory.2. The variations of time-varying storage parameters are closely related to the generation of fast flowe on a hillslope as represented by gully runoffs,and it is possible to inversely estimate the average flow-ststes by identification of the variations.3. A model,in which storage Sc is used to join the ralationship between basin storage and discharge when throughflows predominate and that when fast flows (represented by gully flow) predominate,is introduced. It is shown that Sc can be estimated by nonlinear filtering with only rainfall and discharge data. The method of identifying the parameters using Sc are also shown.4. It is important for lumping problem to clarify space variations of runoff model parameters.