三峡初期蓄水对典型鱼类栖息地适宜性的影响

三峡工程是长江中游干流最大的骨干工程,蓄水后下游水文情势发生明显改变。分析水库运行后下游水文情势的改变情况,将为了解大型水利工程对河流健康状况的影响程度和开展生态保护提供有意义的信息和帮助。本文选择宜昌站作为研究对象,并以中华鲟和四大家鱼为典型代表物种,研究三峡工程初期蓄水对下游生态系统的影响。结果表明,三峡工程蓄水运行后,坝下宜昌站生态水文条件发生明显变化,主要表现为多年平均水温上升,多年平均流量、水位和含沙量下降;非汛期的水温以及汛期的流量、水位和含沙量月径流过程明显改变;下游生态水文条件的改变,导致中华鲟鲟卵孵化适宜度和四大家鱼产卵适宜度明显降低;栖息地内生态水文条件的变化是影响中华鲟鲟卵孵化和四大家鱼产卵行为的关键因素,而不是影响中华鲟产卵和四大家鱼鱼卵孵化的关键因素。     

三峡水库135 m蓄水过程分析

三峡水库135m蓄水是逐步发挥三峡工程综合效益，保证三期工程顺利施工的关键。2003年6月10日22时三峡水库如期蓄水至135m，标志着三峡工程进入了建设施工与生产运行并重的崭新阶段。为此，就135m蓄水对坝址上游、两坝间、葛洲坝下游水位变化的影响，蓄水期间三峡泄水建筑物的逐步启用，蓄水后水库回水末端的确定，梯级枢纽形成后水库调度中存在的问题等进行了较为详细的分析，从而为梯级水库调度和后期三峡工程的156、175m蓄水提供借鉴。     

水库蓄水初期水质分析及影响因素

对某大型水库蓄水初期水质空间分布进行了调查分析。设置了2个断面共5个采样点,进行每周1次共5次的跟踪监测。在库区淹没土壤类型调查和土壤浸出试验的基础上,根据库容曲线,计算土壤浸出物对水库水质的贡献值及单位面积土壤主要污染物的浸出量,并探讨土壤浸出对水库水质的影响趋势。结果表明:水库库区土壤养分在蓄水初期对水质有一定影响,这种影响随着水质的不断交换将逐渐减弱并达到新的动态平衡。     

自重与初次蓄水对特高拱坝应力的影响

以小湾拱坝为例,对不同自重施加方式及初次蓄水条件下大坝的应力进行了三维数值仿真分析。对不同施工方案的应力对比研究结果表明,自重施加方式、封拱灌浆过程及初次蓄水均对坝体应力分布有较大影响,自重全部由梁承担过小地估计了坝体上游拉应力,而整体施加自重、水压时,计算得到的拉应力偏大,从计算精度考虑,小湾拱坝应力计算按10次以上的分期浇筑、分期封拱及分期蓄水过程模拟为宜。     

The distribution and turnover of benthic organic matter in a lowland river: influence of hydrology,seston load and impoundment

The standing stocks of benthic organic matter (BOM) and some of its biochemical compounds (particulate organic carbon, particulate nitrogen, protein, and chlorophyll a) were investigated in the upper 12 cm of the sediments at several sampling sites in a free‐flowing and in an impounded river section of the lowland River Spree (Germany). Several environmental variables were recorded, in order to determine their potential influence on the organic matter content in the sediments. It was shown that the organic matter content in the upper sediment layers was mainly determined by the local hydrological regime, which was best reflected by the particle size distribution at the sampling sites. For the deepest investigated sediment strata, no influencing factors could be determined. The amount and quality of suspended matter was of minor importance to sediment composition. Also seasonal effects could not be detected. The impounded river section exhibited less seasonal variation in organic matter storage, as well as shorter carbon turnover lengths, longer carbon turnover times and lower rates of annual organic matter recycling than the free‐flowing river section, which indicates that changes in river hydraulics result in alterations to the organic matter budget. These alterations could be related to the changed mesohabitat composition and to the higher standing stocks of organic matter in the impounded river reach. We conclude that both morphological and hydrological alterations affect the structure and function of running water ecosystems because of their negative effect on the organic matter cycling. Copyright © 2002 John Wiley & Sons, Ltd.     

浅谈三峡水库139 m水位蓄水

2003年10月，国务院批准三峡水库枯水期蓄水至139m水位。在枢纽及库区相关工作准备就绪后，10月26日开始蓄水。11月5日，水库水位蓄到139m，从而提前发挥三峡工程防洪、发电、航运三大效益，其中航运效益尤为突出。     

NATURAL REGENERATION OF FISH ASSEMBLAGES IN THE PILICA RIVER AFTER A REDUCTION OF POINT‐SOURCE POLLUTION

Electrofishing was conducted along the Pilica River, the biggest West tributary of the Vistula, Poland. This paper presents a comparison between the 1990s (1994–1995, 63 sites) and 2000s (2003–2005, 64 sites), that is, because the water quality started improving after 1989. In the Pilica, there is an increased risk of masking relationships between fish distribution and abiotic factors because a dam without a fish pass was constructed in the middle course of the river in 1973, perhaps resulting in fewer possibilities for potential colonizers reaching river fragments fit for colonization. The main aim of this study was to check if natural fish fauna regeneration took place in the river following a significant sewage input reduction. The fish samples were classified with a Kohonen artificial neural network and assigned to two main clusters (X and Y) and, respectively, two pairs of subclusters (X₁, X₂; Y₁, Y₂) of neurons. No species attained its significantly highest biomass and/or frequency (expressed as IndVal) in X₂ (in which samples from the 1990s dominated), whereas 21 species did so in Y₁ or Y₂ (containing almost all of the samples from the 2000s), better testifying to the aquatic environment at the sites where the samples assigned to two latter subclusters come from. Moreover, significantly higher values for Y₁ and/or Y₂ when compared with X₂ were recorded in the richness of the fish species, the total fish biomass and total rheophilic fish biomass. In summary, the positive reaction of ichthyofauna to the improvement of the water quality, stated after 1989, was not recorded during the sampling in 1994–1995, but with a considerable delay in 2003–2005. It should be emphasized that the improvement in fish assemblages was recorded in the Pilica both upstream and downstream from the dam reservoir. A good ecological status was recorded even for some samples from the 1990s. They were collected in the lower river course, where the fish could move freely from the Vistula. This testifies the combined role of the presence of potential colonizers and the functioning ecological corridors for fish assemblages in a river system under human impact. Copyright © 2012 John Wiley & Sons, Ltd.     

EFFECTS OF FLOW RELEASES ON MACROINVERTEBRATE ASSEMBLAGES IN THE INDIAN AND HUDSON RIVERS IN THE ADIRONDACK MOUNTAINS OF NORTHERN NEW YORK

The effects of flow releases (daily during spring and four times weekly during summer) from a small impoundment on macroinvertebrate assemblages in the lower Indian River and upper Hudson River of northern New York were assessed during the summers of 2005 and 2006. Community indices, feeding guilds, dominant species and Bray–Curtis similarities at three sites on the Indian River, below a regulated impoundment, were compared with those at four control sites on the Cedar River, below a run‐of‐the‐river impoundment of comparable size. The same indices at four less‐likely affected sites on the Hudson River, below the mouth of the Indian River, were compared with those at an upstream control site on the Hudson River. Results show that the function and apparent health of macroinvertebrate communities were generally unaffected by atypical flow regimes and/or altered water quality at study reaches downstream from both dams in the Indian, Cedar and Hudson Rivers. The lentic nature of releases from both impoundments, however, produced significant changes in the structure of assemblages at Indian and Cedar River sites immediately downstream from both dams, moderate effects at two Indian River sites 2.4 and 4.0 km downstream from its dam, little or no effect at three Cedar River sites 7.2–34.2 km downstream from its dam, and no effect at any Hudson River site. Bray–Curtis similarities indicate that assemblages did not differ significantly among sites within similar impact categories. The paucity of scrapers at all Indian River sites, and the predominance of filter‐feeding Simulium gouldingi and Pisidium compressum immediately below Abanakee dam, show that only minor differences in dominant species and trophic structure of macroinvertebrate communities occurred at affected sites in the Indian River compared to the Cedar River. Thus, flow releases had only a small, localized effect on macroinvertebrate communities in the Indian River. Copyright © 2011 John Wiley & Sons, Ltd.     

蒲石河抽水蓄能电站初期蓄水及调度运行研究

蒲石河抽水蓄能电站初期蓄水既要满足下游综合用水要求,又要确保电站首台机组投产发电。为此,结合施工度汛等要求,论证蓄水时机、分析下游用水要求、制定蓄水原则,提出水库初期蓄水方案和调度运行方式,为电站早日在电网中发挥作用提供保障。