大坝下游定点区域溶解氧饱和度预测

大坝通过坝身泄流时，巨大的洪水卷吸空气中的大量气体直泻到下游河床，造成下游河道特别是近坝区域气体含量过饱和，给下游水生生物带来不利影响，其中鱼类气泡病就是水体气体过饱和造成的典型病症。为探明大坝泄流对坝下河道溶解氧饱和度的影响，以三峡 葛洲坝区域坝下近坝区定点区域的溶解氧实测资料为基础，建立溶解氧饱和度的BP网络预测模型，对大坝不同运行工况进行下游溶解氧饱和度的预测仿真计算，并将仿真预测值与实测及数值模拟结果进行比较分析。结果得出BP网络模型能很好地逼近坝下近坝区指定区域的溶解氧饱和度，可根据大坝运行工况对下游水体溶解氧饱和度进行快速预测，为有效控制坝下水体溶解氧饱和度提供借鉴

PREDICTION OF DISSOLVED OXYGEN SATURATION IN FIXED AREA DOWNSTREAM OF THE DAM

When the dam discharges water,huge flood takes a lot of gases and rushes down to the lower riverbed,which makes the total dissolved gas supersaturated especially near the dam area and has negative effect on downstream aquatic life.The gas bubble disease of fish is the typical symptom caused by gas supersaturation.In order to investigate the influence of dam discharge to the dissolved oxygen saturation in downstream,based on the measured data of the Three Gorges-Gezhouba Dam area in downstream near the dam the BP network prediction model of dissolved oxygen saturation was built.At the same time,the paper used the BP prediction model to simulate the dam downstream dissolved oxygen saturation at the different operating conditions of the dam.Through the comparison between the result of simulation to measured data and the result of numerical simulation,it was confirmed that BP network model could be a good approximation to the dissolved oxygen saturation in the appointed area of the dam downstream.By use of the BP network model,it can be predicted that the dissolved oxygen saturation of the dam downstream by different operation conditions of dam.So this model can provide the reference for the effective control of dissolved oxygen saturation in the downstream of the dam.