总溶解气体过饱和对鱼类影响研究进展

高坝下泄洪水导致大坝下游河道水体总溶解气体(TDG)过饱和,威胁着下游鱼类的生存。目前,高坝泄洪引起的TDG过饱和问题及其对鱼类的影响,已成为备受关注的生态环境问题之一。针对国内已有的研究,从气体过饱和引起的鱼类气泡病症状、耐受性、回避性等方面进行了总结。发现鱼类对TDG过饱和的耐受性阈值并未确定,TDG过饱和对鱼类影响的解决方案尚未明确。提出进一步开展野外原位观测试验,着手TDG与其他环境因子的耦合作用对鱼类的影响研究,以及利用多学科交叉的方法揭示TDG过饱和对鱼类影响的内在机制,有助于水库调度方案和鱼类保护措施的制定。     

过饱和总溶解气体释放过程预测

通过室内试验,研究泄流水体中过饱和总溶解气体的释放过程,分析了影响气体从水中释放的主要因素。利用原型观测资料对已有的过饱和总溶解气体释放的数学模型进行验证,同时对释放系数公式进行了修正。在此基础上预测了金沙江某电站下游河段过饱和总溶解气体的沿程释放规律。     

水利工程总溶解气体过饱和问题探讨

从对总溶解气体(TDG)过饱和概念的分析入手,阐述TDG过饱和的危害。通过对不同典型水体TDG饱和度的测量,表明泄流可以导致水体TDG含量增加甚至过饱和。在此基础上,采用试验研究的方法,探讨了TDG过饱和产生原因及其释放过程,表明水利工程泄流引起的TDG过饱和与泄流掺气、压力、紊动强度、水温等要素相关,并由此提出减缓水利工程TDG过饱和影响的建议。     

高坝下游水中总溶解气体过饱和研究进展

随着水电工程的不断兴起,高坝建设引起的过饱和水体问题日渐突出。总结了近年来国内外的的研究成果,从鱼类的耐受性、鱼类对过饱和总溶解气体(TDG)的规避效应以及过饱和TDG对鱼类的致死机理3方面分析了过饱和TDG与下游水生生物之间的相互作用,并提出了一些研究思路和想法。此外,还重点论述了促进过饱和TDG释放速率方面取得的进展和不足之处,指出实际工况条件下过饱和TDG的释放易受河流形态等周边环境影响,而实验条件下无法准确反映实际工况,今后室内试验和原型观测需进一步加强。而如何在安全行洪的前提下实现快速高效的TDG释放是该领域下一步研究的重点。     

中国高坝工程过饱和总溶解气体研究进展

高坝泄洪会导致下游水体总溶解气体过饱和,鱼类长期处于这种环境容易患气泡病甚至死亡.为保护生态环境,找出切实可行的TDG饱和度消减措施,我国针对高坝泄洪导致的总溶解气体过饱和现象开展了大量研究.对高坝工程过饱和溶解气体的产生、释放过程、鱼类对过饱和溶解气体耐受性、TDG饱和度预测模型及TDG过饱和减缓措施的研究成果进行了总结,同时针对已有研究成果的不足提出了建议,旨在为进一步开展研究工作提供参考.     

龚嘴水电站总溶解气体过饱和原型观测结果分析

大坝泄水对环境的不利影响之一是会产生总溶解气体(TDG)过饱和现象,导致鱼类患气泡病甚至死亡.在理论分析的基础上,建立了基于面流消能的TDG过饱和浓度预测公式.该预测公式采用平均静水压强作为自变量进行TDG饱和度计算,避免了以往采用很难精确定量的动水压强进行TDG预测而带来的不便.通过对大渡河上龚嘴水电站泄洪期间TDG...     

总溶解气体过饱和含沙水体对齐口裂腹鱼影响的实验研究

高坝泄洪形成总溶解气体(Total Dissolved Gas,TDG)过饱和的含沙水流,由于泥沙的作用,加剧了对高坝下游鱼类的影响。为探讨TDG过饱和含沙水体对鱼类影响的规律,以齐口裂腹鱼幼鱼为实验对象,选取中值粒径为7.4μm的泥沙,对TDG饱和度为100%、120%、125%、130%、135%、140%的水体,分别设置0、20、60、80 mg/L的含沙量实验工况,开展含沙水体TDG过饱和的持续暴露实验。实验结果表明,含沙量不同但TDG饱和度保持为100%不变的实验组中,未出现实验鱼死亡现象。TDG饱和度为130%时,含沙量为0、20、60、80 mg/L的实验组中,实验鱼的半致死时间分别为15.3 h、10.75 h、8.3 h、7.85 h。在TDG饱和度相同时,含沙量越高半致死时间越短,但高含沙量实验组(60 mg/L,80m g/L)的半致死时间相差不大;含沙量相同时,TDG饱和度越高,半致死时间越短。     

金沙江上游梯级联合泄洪对下游河段总溶解性气体过饱和累积影响研究

水电工程建成运行后,泄水建筑物在泄水过程中由于水头高、流速大,会形成强掺气水流。水流进入到水垫塘内时,由于压强的升高导致大量的气体溶解成为溶解气体,从而造成总溶解气体过饱和(Total dissolved gas,简称TDG)现象。本文通过对金沙江上游叶巴滩、拉哇及巴塘三个梯级进行预测分析,研究梯级联合泄洪工况下对总溶解性气体过饱和的累积影响,同时根据研究结果提出减缓影响的建议。     

高坝泄水产生溶解气体过饱和水体对鱼类影响的模拟研究

采用高坝泄洪TDG生成预测模型,考虑泄洪水流的非恒定流特征及过饱和TDG水流在河道内的一维动力学释放,模拟某待建坝高289m的高坝工程以单泄洪洞分别持续泄洪不同时间,下游河段内TDG饱和度水体对鱼类影响。以已有鱼类研究成果为标准,研究得到,泄洪流量一定,泄洪持续时间延长,TDG过饱和水体对下河道内鱼类的影响区域从坝下逐渐向下游延长。当泄洪流量、泄洪时间一定,坝下游河道内TDG过饱和水流对鱼类的影响区域沿河流方向逐渐减小。     

风速对过饱和总溶解气体释放速率的影响

通过不同风速下的过饱和总溶解气体(TDG)室内释放试验,研究风速对过饱和TDG释放过程的影响,并根据已有释放模型对释放系数进行估算,建立了过饱和TDG释放系数与风速的定量关系式。结果表明在8.5~9.5℃条件下,风速较小时,水体中过饱和TDG释放相当缓慢,随着风速的增大,过饱和TDG的释放速率显著增大;在无风工况下,TDG释放系数为0.005 42 h-1;当风速为1.08~11.33 m/s时,TDG释放系数为0.007 09~0.066 68 h-1;相对释放系数为1~12.303,拟合的相对释放系数与风速的定量关系式计算偏差在-11.76%~10.21%之间。     

Tolerance and avoidance mechanisms of the rare and endemic fish of the upper Yangtze River to total dissolved gas supersaturation by hydropower stations

Several superhigh dams (greater than 200 m in height) and many high dams have been built in the upper Yangtze River basin in recent years, and these dams have made total dissolved gas (TDG) supersaturation a serious environmental problem. A few studies have examined the tolerance and avoidance characteristics of rare and endemic fish in TDG‐supersaturated water in the upper Yangtze River over the past 10 years. These studies focused on specific species and specific sizes and did not identify a regular pattern that can be applied to all resident fish in the upper Yangtze River. However, elucidating this type of pattern is crucial for fishery management and dam operations in the upper Yangtze River. Data on the median lethal time (LT₅₀), horizontal avoidance percentage, and vertical water depth of three rare and endemic species in the upper Yangtze River from previous studies were used in the current work. An exponential relationship was found between LT₅₀ of fish and TDG supersaturation. The avoidance percentage of fish has a linear relationship with TDG supersaturation. Fish in the upper Yangtze River can use depth compensation to avoid the threat of TDG when the saturation is 130% or above but rarely avoid the threat of TDG when the saturation is less than 125%. We also described the tolerance and avoidance characteristics of fish in a TDG‐supersaturated river downstream from a super‐high dam. When the dam discharged a two‐year flood, the LT₅₀ values of fish downstream ranged from 9.1 to 27.5 hr regardless of depth compensation. The avoidance percentage of resident fish ranged from 8.4 to 44.8%. The resident fish swam to a water depth of 2.43–3.33 m to avoid the threat of TDG.     

梯级水电站间河道型水库非恒定流调节

梯级水电站河道中的下游库区水流处于准稳态时，非恒定流态与河道初始条件及上、下游边界条件有关．通过对初始条件和边界条件的动态调节，协调上、下游电站日放水过程，以达到有效利用水资源的目的．     

Experimental study on total dissolved gas supersaturation in water

More and more high dams have been constructed and operated in China. The total dissolved gas (TDG) supersaturation caused by dam discharge leads to gas bubble disease or even death of fish. Through a series of experiments, the conditions and requirements of supersaturated TDG generation were examined in this study. The results show that pressure (water depth), aeration, and bubble dissolution time are required for supersaturated TDG generation, and the air-water contact area and turbulence intensity are the...     

In situ study on the impact of total dissolved gas supersaturation on endemic fish in the Upper Yangtze River

Total dissolved gas (TDG) supersaturation in the upper Yangtze River caused by high spill rates upstream of hydroelectric dams has become a serious environmental problem in recent years. TDG supersaturation downstream of the Xiangjiaba Dam was investigated during flood periods in 2014 and 2015. Alongside this, an in situ study was conducted to evaluate the impacts of TDG supersaturation on grass carp (Ctenopharyngodon idellus) and rock carp (Procypris rabaudi). TDG supersaturation levels ranged from 115% to 131% in 2014 and from 118% to 128% in 2015. During 2014, TDG supersaturation first decreased and then increased and finally remained relatively stable. In contrast, the TDG supersaturation level remained between 122–126% for a relatively long time in the 2015 study period. During 2014, grass carp confined to water depths of 0–1 and 1–2 m began to die after 45 hr of exposure, and most grass carp died between 90 and 130 hr when TDG supersaturation level was greater than 127%. The first observed death during 2015 occurred after 30‐hr exposure. The survival of rock carp was greater than 50% when they were restricted to water depths of 0–1 m. Only three rock carp died when they were confined to water depths of 0–2 m, and no dead fish were recorded at water depths of 0–3 m.     

梯级水电站间水库调节效益偿付方法研究

１９９７年１２月１４日，四川省人民政府颁布第９５号政府令《四川省流域梯级水电站间水库调节效益偿付管理办法》，这也是我国第一部有关河流水电梯级开发过程中进行水库调节效益偿付的地方性法规。但由于缺乏一上游水库对下北级电站调节效益的规范的计算方法，实施情况不尽如人意。为此，依据该法规，按“有”“无”原则进行水库调节效益计算的方法，提出了“核定电量基数”的概念，给出了下流站对上游水库的效益偿付公式，并以嘉     

梯级水电站水库洪水补偿调度方式应用研究

文章分析了宝兴河流域梯级水电站确定洪水补偿调度方式的必要性,根据流域防洪特点将划分宝兴河流域梯级水电站水库群防洪系统结构,应用水库群洪水补偿调度通用模型计算分析。通过实例研究表明,应用洪水补偿调度方式,可以更好的实现削峰目标,有效减轻电站及下游防洪控制点的防洪压力。     

白水河梯级电站的调度工作

梯级水电站的优化调度，是为了充分利用水力资源、发挥梯级水电站的整体优势、提高水电站经济效益并达到使电网安全运行的目的。结合白水河梯级电站的调度工作具体阐述要做好梯级水电站的调度工作，需要调度值班员与各电站运行员及水文站工作人员的密切配合，相互协作。图1幅。