河流水质随机分析模型及其应用

本文以河流ＣＢＯＤ－ＮＢＯＤ－ＤＯ水质方程为例，推导出计算河流水随机分析新模型，该模型将水不质基本方程的各个参数扩展为随机变量，并分解出均值方程一随机脉动量方程，然后求状态变量的积分解和分布矩；其次，利用分布矩和Ｆｏｋｋｅｒ－Ｐｌａｎｃｋ方程产生概述密度函数，模型被应用于清安河的水质模拟，与 ｏｎｔｅＣａｒｌｏ模型和实测资料吻合良好

Stochastic analysis model and its application for river water quality

The CBOD-NBOD-DO equations for river water quality modelling are studied to develop stochastic analysis model for predicting the river water quality. First, the basic governing equations are expanded to include stochastic terms. Stochastic terms are separated from nonfluctuating terms, and the resulting set of equations is solved simultaneously. Solutions are used to calculate the moments of the output variables. Second, the moments are used in conjunction with the Fok-ker-Planck equation to produce an analytical solution for the probability density functions of the dependent variables. The model is used to calculate water quality for Qingao river. The calculated results are in good agreement with Monte Carlo model and field data.