南水北调中线工程不同调水方案下的汉江水华发生概率计算模型

为了评估南水北调中线工程对汉江中下游水华的影响，在汉江水华发生成因机理分析结果的基础上，对汉江水华发生的概率进行了定性分析；提出汉江水华发生概率的计算模型，并对汉江水华发生的概率进行了定量计算。该模型由水体富营养化模型、河流一维水动力学模型以及随机数生成模型组成，它不仅可以模拟汉江水华发生的机理，而且可以对诱发水华的各种因子进行随机抽样组合，从而求出各方案实施后汉江水华的发生概率。计算结果表明南水北调中线工程调水方案实施后将增加汉江水华发生的概率，而引江济汉工程的兴建将大大减少汉江水华发生的概率。汉江自身的水污染治理是减少水华发生概率的最根本措施。丹江口水库和引江济汉工程的联合调度将减小汉江水华发生的概率。

Water bloom occurrence probability calculation model in Hanjiang River under different water transfer schemes of the middle route of South to North Water Transfer Project

The model for calculating the occurrence probability of water bloom in Hanjiang River was put forward and the probability was calculated quantitatively. The model consists of a water body eutrophication model, a 1-D river hydrodynamic model and a random generation model. It not only simulates the generation mechanism of water bloom,but also randomly assembles all sorts of factors inducing water bloom. The calculation results indicate that the probability of water bloom occurrence will increase if 82×108m3 or 145×108m3 water was transferred from Hanjiang River. But the probability will remarkably decrease if the diversion project for transferring the water from Yangtze River to Hanjiang River is established. The water pollution control of Hanjiang is the most important measure for reducing the occurrence probability of water bloom. The joint regulation of Danjiankou reservoir and water transfer project from Yangtze River to Hanjiang River will reduce the occurrence probability of water bloom in Hanjiang River.