【摘要】 针对水文过程中存在的许多随机不确定性因素,本文以Nash模型为基础,利用随机微分方程理论,在确定性汇流模型中引入随机输入项,建立了输入具有白噪声特性的随机Nash汇流模型,求解得到出流过程均值和方差的解析解和数值解,并利用出流过程的均值和方差确定各时刻出流过程的概率分布。该方法借助于各时刻的方差得到流量过程的分布概率,从而考虑预报的不确定性,为防洪决策提供预报值的不确定度,有利于降低水库调洪风险率。更多还原

【Abstract】 Since too many random uncertain factors exist in hydrological processes,the theory of stochastic differential equation is adopted and random input term is introduced.On the basis of the Nash model of n=3,Nash stochastic flow concentration model whose input terms have characteristics of white noise was established,and then,analytical solution and numerical solution of mean and variance of the outflow process were derived.In the mean time,the probability distribution of the outflow process at specific moment was attained with the help of mean and variance of the outflow process.The model can obtain the probabilities distribution of the outflow process by means of variance at specific moment,thus the uncertainties of the prediction are considered which can quantify the uncertainties of predictaion in flood control decision so as to consider the risk loss of decision.更多还原