描述水文频率曲线的一种新的数学模型

Method and Application of Simulating Hydrological Frequency with Polynomial in One Indetermiate

水文频率曲线的绘制常用的两种方法是"求矩适线法"及"三点适线法",除此以外,还可以用其它的方法,其中,用一元多次函数直接描述水文频率曲线,具有简单、实用的特点,其数学模型为Qp=a0+a1p+a2p2+……+anpn,n为奇数,一般取5或7即可。通过实例确定了系数a0、a1…an的值,求出了指定频率的流量,并与"求矩适线法"进行了比较,"一元多次函数法"在多数情况下优于"求矩适线法",能满足水文分析的精度要求,当频率过小时(如小于0.5%),"一元多次函数法"误差较大。

The common two methods of drawing hydrological frequency curve are 'seeking-matrix curve fitting' and 'three-point curve fitting'. In addition, there are other methods. Among these methods, 'polynomial in one indeterminate' may be used to simulate hydrological frequency curve, it is very simple and practical, its mathematical model is Qp=a0+a1p+a2p2+......+anpn, n is odd number, and it is usually 5 or 7. With an example, the way of describing hydrological frequency is discussed. Then mathematical model of simulating hydrological frequency is set up. Comparing with traditional method, it can satisfy hydrological analysis demand. Meanwhile, the scope of application of the method is also discussed.