水面蒸发对南水北调江苏段调水效率的影响

为了掌握南水北调东线江苏境内工程输水河道和调蓄湖库水面蒸发损失水量,及其所造成的泵站机组损失功率,了解水面蒸发对工程调水效率的影响,分析比较了适用于工程所在地区的水面蒸发量计算模型和计算公式,计算了工程沿线输水河道和调蓄湖库的水面蒸发量,分析了工程水面蒸发量的时间和空间分布特征.通过积分,计算了水面蒸发造成的各梯级泵站的流量损失和输入功率损失,求解并分析了水面蒸发对整个江苏段工程调水效率的影响.结果表明：工程沿线水面年蒸发量自南向北、西北方向逐渐递增;蒸发量夏季最高,冬季最低;全线平均水面年蒸发量为862.2 mm.洪泽湖、骆马湖、白马湖和输水河道蒸发损失水量分别占总蒸发损失水量的77.7%,13.3%,3.6%和5.4%,蒸发损失水量约占源头泵站抽水量的17.46%,使工程平均调水效率降低10.33%.调水工程可以考虑采用管道输水,从而避免蒸发损失.

Effects of water surface evaporation on water transfer efficiency for Jiangsu section of South-to-North Water Diversion Project

In order to know the evaporating capacity of channel and lake reservoir water surface along Jiangsu section of the Eastern Route of South-to-North Water Diversion Project(JERP),its power loss of the pumping stations and its influence on water transfer efficiency of JERP,evaporating capacity calculating models and formulae which are suitable for the areas where JERP locates were analyzed and compared.Evaporating capacity of every channel and lake reservoir water surface along JERP was calculated by integral.Both spacial and temporal distribution characteristics of the evaporating capacities of water surfacs were analyzed.The discharge loss and input power loss of every step pumping stations caused by water surface evaporation were calculated.The effect of water surface evaporation on water transfer efficiency of JERP was computed and analyzed.The results show that the evaporating capacities of water surfaces gradually increase from south to north and north- west,and are largest in summer and least in winter.The annual average evaporating capacity of water surfaces amounts to 862.2 mm.The evaporation water volume losses of Hongze Lake,Luoma Lake,Baima Lake and water transfer channels are 77.7%,13.3%,3.6% and 5.4% of the total evaporation water volume loss respectively.17.46% of the water pumped by source pumping stations loses for evaporation,which causes water transfer efficiency of JERP to decrease by 10.33%,and that is a considerable energy loss.Pipelines could be considered for the great water transfer projects which could avoid evaporating capacity of water surface.