西江干流敏感生态需水量研究

西江干流是珠江流域内最重要的鱼类产卵场分布区和鱼类洄游通道,其敏感生态需水可由控制断面的鱼类繁殖期适宜生态流量来确定。针对西江干流河道实际情况,选取迁江站和梧州站作为控制断面,依据西江鱼类产卵繁殖所需流速,采用生境模拟法估算西江干流迁江站、梧州站断面生态敏感期的适宜生态流量分别为1 722 m3/s、5 213 m3/s,敏感生态需水量分别为183亿m3、575亿m3,并利用Tennant法对计算结果进行了分析评价。该研究结果为西江干流的鱼类生境保护及水资源配置提供了技术依据。     

北引渠首工程鱼道方案设计

北引渠首工程过鱼设施的修建主要是解决嫩江中游一些经济鱼类的短距离生殖和索饵洄游,以及一些珍稀濒危冷水性鱼类的封冰前越冬洄游。对北引渠首工程的过鱼设施进行了研究、方案论证和设计,结合工程的运行调度,最终选择了能够较好适应低水头特点的原生态式鱼道。     

长江上游铜鱼产卵流速特性分析北大核心

长江上游是国家级珍稀特有鱼类保护区,上游水电工程的运行改变了保护区江段的水文情势,对鱼类产卵行为造成了一定影响。以铜鱼产卵场典型断面为基础,分析流量、水位和流速等指标的变化特性及其与铜鱼产卵规模的相关性认为,铜鱼产卵需要流速上涨刺激,对流速上涨的速率、波动次数、波动幅度等暂无明确要求,每年1月~7月流速最大差值是铜鱼产卵规模的指示性指标,与铜鱼产卵规模正相关。保护区流速受上、下游水库联合调度影响,只有同时采取生态调度,才能更好地满足保护区河道的生态保护要求。     

长江上游铜鱼产卵流速特性分析

长江上游是国家级珍稀特有鱼类保护区,上游水电工程的运行改变了保护区江段的水文情势,对鱼类产卵行为造成了一定影响。以铜鱼产卵场典型断面为基础,分析流量、水位和流速等指标的变化特性及其与铜鱼产卵规模的相关性认为,铜鱼产卵需要流速上涨刺激,对流速上涨的速率、波动次数、波动幅度等暂无明确要求,每年1月~7月流速最大差值是铜鱼产卵规模的指示性指标,与铜鱼产卵规模正相关。保护区流速受上、下游水库联合调度影响,只有同时采取生态调度,才能更好地满足保护区河道的生态保护要求。     

水文变异下淮河长吻鮠生境变化与适宜流量组合推荐

以淮河干流鱼类长吻鮠为保护目标,建立长吻鮠分时期生态需求与流量之间的概念性模型。对FLOWS法进行改进,加入水文变异前后长吻鮠生态环境对比分析,根据分析结果推荐一组适于长吻鮠生长繁殖的流量组合。结果表明,在环境流量成分的对比分析中,变异前的高脉冲流量历时长、发生时间合适,变异后发生洪水的频率增高,变异前的流量更适于长吻鮠的生长繁殖;在相关水力参数满足程度的对比分析中,在长吻鮠生长繁殖的各个时期,变异前的流量条件均优于变异后。选取变异前的平水年1970年的流量作为基础,推荐适宜流量组合,即产卵期的流量为545~1 212m~3/s,幼鱼索饵期应大于1 750 m~3/s,越冬期应大于等于74 m~3/s。该研究可为保护淮河珍稀物种,为淮河生态调度提供依据。     

补偿中华鲟产卵场水动力环境的梯级水库联合生态调度研究

三峡—葛洲坝梯级水利枢纽工程的建设和运行阻隔了长江部分洄游鱼类的洄游通道,梯级水库的联合调度运行改变了坝下河道天然径流过程,对被迫在坝下形成新产卵场的珍稀水生物中华鲟的产卵繁殖产生一定影响。为有效保护中华鲟资源,在明确梯级水库调度运行与中华鲟产卵场产卵适合度相关性分析的基础上,提出优化三峡下泄流量和葛洲坝运行方式相结合的三峡—葛洲坝梯级水库生态调度方式,以补偿中华鲟产卵栖息所需的河流生境。通过以三峡水库的实际来流过程输入水库生态调度模型,得出中华鲟产卵期(每年10—12月)补偿其产卵栖息水环境的梯级水库联合生态调度方式。根据梯级水库生态调度与现有调度结果进行分析比较结果表明:梯级水库联合生态调度可在满足三峡水库常规调度目标的基础上同时满足中华鲟产卵所需的生态流量,配合葛洲坝电厂优化调度运行方式,可有效增加坝下中华鲟产卵场水动力环境产卵适合度,补偿梯级水库运行对中华鲟产卵生境造成的不利影响。     

长江上游珍稀特有鱼类繁殖生长的关键环境因子研究启动会在渝召开

2012年7月1日,由中国三峡集团组织,中国水利水电科学研究院承担,长江水文上游局、长江科学院、清华大学协作开展的长江上游珍稀特有鱼类繁殖生长的关键环境因子研究启动会在渝召开。金沙江下游4个梯级电站的建设运行将改变长江上游珍稀特有鱼类保护区河段的河流生态特性,进而对鱼类自然繁殖生长产生明显影响。因此,开展保护区珍稀特有鱼类繁殖生长的关键栖息地和关键环境因子研究,了解环境因子     

水库建设影响河流鱼类生境的保护研究

由于水库的建设会对河流产生阻隔,从而影响鱼类洄游、产卵、索饵等,本文以赤峰市东台子水库为例,结合西拉木伦河流域特征、水库特性及鱼类生活习性、繁殖特征等,简要阐述了通过采取水库生态调度、鱼类增殖放流站及鱼道建设等保护措施,对河道内的鱼类生境进行有效保护,可减少水库工程建设对鱼类生境的影响。     

向家坝蓄水前后长江上游珍稀特有鱼类国家级自然保护区物理完整性评价

采用流量过程变异程度、高流量频率、高流量历时偏差、岸坡稳定性、栖息地类型多样性、底质类型多样性、河岸植被覆盖度、垂向透水性等8项指标对向家坝蓄水前后长江上游珍稀特有鱼类国家级自然保护区部分关键河段的物理完整性进行了评价研究。结果表明:赤水河的物理完整性远高于长江干流,长江干流的3个河段中江津段的物理完整性较高,其次是宜宾和合江。向家坝蓄水前后,高流量频率、高流量历时偏差、栖息地类型多样性、垂向透水性等4项指标差异较大。向家坝蓄水对保护区关键河段水文过程,特别是脉冲流量及其持续时间、底质中值粒径和水深、流速的分布等具有一定程度的影响。研究结果可为长江上游干支流物理完整性评价提供借鉴。     

大坝对长江流域洄游鱼类的影响

大坝的隔离,使长江与通江湖泊的关系受到威胁,洄游性鱼类失去了原有丰富的栖息地,直接影响到一些江湖洄游性鱼类的生长与繁殖.根据对不同时期的渔获物组成、三口分流水量和分流比、中游及洞庭湖鱼苗产量、四大家鱼产量、四大家鱼在鱼类资源中的比例和监利四大家鱼鱼苗径流量的统计分析,得出了大坝对以四大家鱼为代表的江湖洄游性鱼类资源量的影响.结果表明,大坝对长江中下游鱼类物种组成和丰度有一定影响,优势物种趋于集中,大坝对水文规律的调节对鱼类的产卵量有一定不利影响,江湖关系的连通度决定着洄游性鱼类的生长与繁殖.为降低工程对生态的影响,水库的运行,特别是在产卵期应结合生态的需要,应进行优化调度.     

Bayesian network models for environmental flow decision‐making: 1. Latrobe River Australia

Current methods underpinning environmental flow (eFlow) decisions often lack transparency, do not adequately consider uncertainties and rarely include adaptive management principles. We report the development and application of an eFlow Bayesian Network (BN) model that links four flow components with an ecological model to predict the spawning and recruitment of two important native fish species, the Australian Grayling and River Blackfish, in the highly regulated and flow‐stressed lower Latrobe River in Victoria, Australia. Autumn high flows, in conjunction with low stream temperature, are critical for Grayling spawning. The BN model was used to predict the probability of spawning and recruitment of these two native fish species for four flow scenarios. Quantitative data, flow simulation models and expert judgement were used to parameterize the BN model. The model results showed clearly that currently, and into the future, there is a very low likelihood of spawning and recruitment of Australian Grayling in the lower Latrobe. River Blackfish are minimally affected by the predicted reductions in flow and increased stream temperatures. Management scenarios aimed at modifying flows and stream temperatures to increase the likelihood of successful spawning and recruitment of Australian Grayling were assessed. Self‐sustaining populations of Australian Grayling could conceivably be achieved in the upper reaches of this river if fish passage was provided through an on‐stream reservoir. A major benefit in building and applying an eFlow BN model is that it can facilitate meaningful analysis and discussion of the ecological effects of particular eFlow regimes. Copyright © 2010 John Wiley & Sons, Ltd.     

Habitat associations of upper Volga river fishes: Effects of reservoirs

Habitat associations of upper Volga river fishes are defined within a cycle of spawning, feeding and overwintering migrations. The migration cycles of resident riverine fishes are categorized as obligate rheophils, limno-rheophils and limnophils. Forty-four fish species in 14 families occurred in the upper Volga River before regulation. Four mainstem reservoirs were constructed on the upper Volga between 1937 and 1957: Ivankovo, Uglich, Rybinsk and Gorky. They are maintained in a stage of delayed and sustained annual flood pulse. Additional impacts of reservoir construction include the creation of a new pelagic habitat, replacement of floodplains by lacustrine littoral and sublittoral habitats, creation of a complex bathyal habitat from former river channels and replacement of riverine flow patterns by pelagic water mass circulations. Populations of rheophilic species declined, while a new pelagophilic fish guild developed. Forty-six fish species are now present; seven species were lost and nine introduced after impoundment. Spawning, feeding and wintering habitats are outlined for reservoir guilds. Ichthyomass increased three to four times following reservoir construction and commercial fish harvest from Rybinsk Reservoir between 1945 and 1992 ranged from 2220 to 4304 t/y. Reservoirs of the upper Volga have limited bioproductivity due to a deficiency and uneven distribution of reproductive habitats, decreasing bottom irregularity, seasonal anomalies of flooding and draining of the littoral and sublittoral and underestimating the importance of tributaries. Lack of littoral reproductive habitat can be remedied by increasing the area of protected littoral through the construction of chains of small islands, diking and reclamation of bogged areas. Improved reproduction of migrating local stocks can be achieved by removing sand bars across tributary mouths, construction of artificial spawning grounds and restoration and preservation of preferred habitats in the main channel.     

水电工程建设前后外来鱼类入侵问题初步研究

随着我国水电工程建设的不断推进,工程建设和运行中产生的外来鱼类入侵问题受到越来越多的关注。以研究资料较为丰富的雅砻江二滩库区、长江三峡库区、黄河上游龙羊峡至刘家峡河段作为典型研究区域,系统梳理了库区河段外来鱼类的种类组成、资源量、生态特征和引种途径等。研究发现:库区外来鱼类中的经济鱼类主要由人为有意引种而引入,而小型鱼类主要是人类无意引种而带入;水库蓄水初期库区河段由于水动力学过程变化和营养盐输入增加,库区水体初级生产力大幅提高,这为外来鱼类的定植和扩散提供了丰富的饵料来源;外来鱼类进入库区后通过与土著鱼类竞争饵料资源和生活空间、破坏土著鱼类的种群补充、污染土著鱼类的种质资源等,造成库区河段土著鱼类的种类和种群数量显著下降。为降低外来鱼类造成的生态危害,提出了严控人为引种和传播、及时预警和监测、加强土著鱼类保护、降低外来鱼类种群数量等对策措施。     

Quantitative evaluation of fish alternative habitats in the Luosuo RiverEI北大核心CSCD

针对罗梭江替代生境适宜度及影响因素尚缺乏定量分析的问题,选取澜沧江干流特有经济鱼类中国结鱼(Tor sinensis)为目标物种,基于河流内流量增加法(IFIM),结合二维水动力模型和鱼类栖息地适宜性曲线,建立了罗梭江典型鱼类的栖息地评价模型,分析了替代生境适宜度及其影响因子。结果表明:罗梭江作为澜沧江最大支流,能为中国结鱼提供良好产卵场,产卵场在丰水期(7—9月)数量和质量较优,高质量产卵场主要分布于河流蜿蜒处;罗梭江不适宜成鱼全年栖息,尤其在枯水期(2—4月),成鱼产卵及育肥适宜度最差。在罗梭江替代生境后期管理中,建议优先加强对河流弯道处的生境保护及捕捞管理,同时重视其关联干流的生态保护。     

岷江下游航电梯级生态流量协同造峰调度研究

岷江下游4个水电梯级的开发将对最下游梯级水电站(龙溪口)坝址下长江上游珍稀、特有鱼类国家级自然保护区内的重点保护鱼类产卵、繁殖关键生命周期的洪峰流量过程产生影响。因此,有必要开展梯级电站生态流量联合调度研究。研究认为,在鱼类产卵高峰期的7~8月,梯级电站可分预泄-敞泄-回蓄3个阶段实施造峰调度,老木孔,东岗岩,犍为和龙溪4个梯级同步敞泄,保证洪峰顺利通过各梯级,维持下游天然水文过程;洪水过后,采取专门的调度措施回蓄,延长回蓄时间,保证退水过程与天然洪峰保持基本一致,避免造成下游减脱水过程。研究方案的实施可为下游长江珍稀特有鱼类提供类似天然的水文过程,减轻水电梯级开发对鱼类产卵的影响。     

Benefits to 0+ fishes of connecting man‐made waterbodies to the lower River Trent,England

Floodplain waterbodies are reputed to enhance recruitment of riverine fish populations via provision of spawning and nursery habitat, refuge from floods, and increased availability of planktonic food resources compared with main river channels. Notwithstanding, there have been few parallel studies of fishes and their food resources at both main river and floodplain sites. Thus, this study investigated the 0+ fishes, zooplankton and phytoplankton (chlorophyll a) at four main river and four (man‐made) floodplain sites on the lower River Trent, England, between May 1999 and October 2004 inclusive. All sites shared the same key fish species, and there were no consistent differences in the densities, growth or condition of 0+ fishes from main river and floodplain sites. Similarly, all sites shared the same key zooplankton taxa. However, zooplankton densities, notably of large‐bodied cladocerans, and chlorophyll a concentrations, were significantly higher at floodplain sites than at main river sites. Thus, connection of man‐made waterbodies has the potential to enhance recruitment of riverine fish populations via provision of important spawning and nursery habitat, and superior feeding opportunities for 0+ fishes compared with main river channels. Copyright © 2007 John Wiley & Sons, Ltd.     

近年来长江水功能区水质达标情况分析

根据近5 a来长江流域水资源质量公报和水资源公报等方面的监测数据,初步分析了长江干流及主要支流水功能区一级区和二级区中饮用水源区水质达标情况,并对主要污染物质变化情况进行了讨论。分析结果表明:①水功能区一级区达标率明显提高,其中河流达标率始终高于湖库,湖库达标率年内变幅较大;②水功能区二级区达标情况虽然也提高了11.6%,但湖库饮用水源地达标率仍然处于下降状态;③从长江流域水资源二级区看,各河段水功能区一级区达标率都有所改善,改善最明显的是宜宾—宜昌江段,其次是岷沱江,除金沙江石鼓以下干流和嘉陵江等山区河流外,大部分江段枯季达标率相对较差,说明长江水质总体尚好的主要原因是巨大的水环境容量;④河流饮用水源区达标率比较高,但年内变幅也较大,改善比较大的是宜宾—宜昌干流和湖口以下干流,分别提高了50.6%和29.2%,乌江有所退步,达标率下降了21.6%,主要超标项目是总磷;⑤随着点源治理效果显现,总磷已经超过氨氮和化学需氧量(COD),成为长江几乎所有水体最主要的超标项目。总之,要进一步提高长江水质达标率,需要根据各水域主要污染源,精准控源,科学调控和持久发力。     

ECOLOGICAL FUNCTIONS OF FISH BYPASS CHANNELS IN STREAMS: MIGRATION CORRIDOR AND HABITAT FOR RHEOPHILIC SPECIES

The introduction of weirs into stream ecosystems resulted in modifications of serial continuity and in the decline of riverine fish species. Successful river restoration requires information on the ecological functionality of fish bypass channels that are considered an ecological improvement according to the European Water Framework Directive. In this study, we compared the functionality of three nature‐oriented fish passes as compensatory habitats and migration corridors for fishes. Fish passes differed significantly from upstream and downstream reaches of the weirs, revealing higher current speed, lower water depth, smaller channel width and greater habitat variability. Following these structural differences, they provided key habitats for juvenile, small and rheophilic fishes that are typically underrepresented in highly modified water bodies. All fish passes were used as migration corridors, with increased fish movements during high discharge and at spawning periods. Because river stretches with high variability of current speed and water depth are scarce in highly modified water bodies, fish passes can play an important role as compensatory habitats and should thus be considered more intensively in habitat assessments and river restoration. Ideally, fish bypasses should mirror the natural discharge dynamics and consider all occurring fish species and sizes. Copyright © 2011 John Wiley & Sons, Ltd.     

长江上游鱼类资源变迁及其保护评析

长江上游地区既是众多珍稀、特有鱼类的主要分布区,又是我国水电开发的主要基地,因此,开展水电建设对生态环境带来的影响及生态环境保护方面的研究具有十分重要的意义。对长江上游鱼类资源特点、现状及其保护情况进行了分析总结。随着水资源开发等人类活动的日益加剧,长江上游出现鱼类生物多样性下降、渔业资源衰退、物种加速濒危等问题;虽然采取了包括自然保护区和人工繁殖放流站建设在内的一些措施,并取得了一定效果,但长江上游鱼类仍面临巨大的生存威胁。产生这些问题的原因既有渔猎技术的改进,也有水电工程建设。在分析长江上游鱼类资源存在问题的基础上,提出了相应的保护措施。