Regulation of sediment regime of river ecosystems

Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 23–28, August, 1991.     

Ecological connectivity in alluvial river ecosystems and its disruption by flow regulation

The dynamic nature of alluvial floodplain rivers is a function of flow and sediment regimes interacting with the physiographic features and vegetation cover of the landscape. During seasonal inundation, the flood pulse forms a ‘moving littoral’ that traverses the plain, increasing productivity and enhancing connectivity. The range of spatio-temporal connectivity between different biotopes, coupled with variable levels of natural disturbance, determine successional patterns and habitat heterogeneity that are responsible for maintaining the ecological integrity of floodplain river systems. Flow regulation by dams, often compounded by other modifications such as levee construction, normally results in reduced connectivity and altered successional trajectories in downstream reaches. Flood peaks are typically reduced by river regulation, which reduces the frequency and extent of floodplain inundation. A reduction in channel-forming flows reduces channel migration, an important phenomenon in maintaining high levels of habitat diversity across floodplains. The seasonal timing of floods may be shifted by flow regulation, with major ramifications for aquatic and terrestrial biota. Truncation of sediment transport may result in channel degradation for many kilometres downstream from a dam. Deepening of the channel lowers the water-table, which affects riparian vegetation dynamics and reduces the effective base level of tributaries, which results in rejuvenation and erosion. Ecological integrity in floodplain rivers is based in part on a diversity of water bodies with differing degrees of connectivity with the main river channel. Collectively, these water bodies occupy a wide range of successional stages, thereby forming a mosaic of habitat patches across the floodplain, This diversity is maintained by a balance between the trend toward terrestrialization and flow disturbances that renew connectivity and reset successional sequences. To counter the influence of river regulation, restoration efforts should focus on reestablishing dynamic connectivity between the channel and floodplain water bodies.     

基于生态指标的水库影响下河流水文情势评价

本文通过基于FDC的生态指标综合评价了太子河流域上水库建设对水文情势的影响.结果表明:(1)水库建设后,秋季高流量组分与发生频率减小,春季和夏季低流量组分值显著增加;(2)年生态盈余受水库影响小,生态赤字受水库影响较大,季节生态指标受水库影响较大,尤其在春季和夏季.     

River-bed quarry excavations and their effect on the hydraulic regime of river flow

Conclusion The proposed hydraulic calculation is sufficiently universal. It makes it possible to take into account, under conditions of the two-dimensional problem, the effect of the length of a quarry, its depth, ratios of the upstream and downstream slopes of the quarry, and surface roughness within the quarry excavation on a drop of the water level. As a first approximation the proposed method can be applied also to the case of the three-dimensional problem.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 5, pp. 19–21, May, 1991.     

用变化范围法(RVA)确定河流环境流量

介绍了确定河流环境流量的一种新方法--变化范围法(RVA)的形成、研究现状及应用进展.在分析水文变化指标(IHA)的基础上,总结未受干扰的时间序列中的流量范围作为初始的环境流量范围,并通过监测生态影响来修正该流量范围,并论述了水文变化指标与变化范围法的关系.     

浅析黄河小浪底水库异重流演进规律

通过实测资料对小浪底水库异重流演进规律的初步分析,定性地提出了影响其运动的因素;同时,对某些影响因素进行了定量分析,得出了异重流到达小浪底大坝坝前的条件和时间的经验公式。验证了范家骅在水槽内异重流潜入条件试验的研究成果。     

河道生态环境需水研究方法比较

对近年来的河道生态环境需水研究方法进行了回顾和分析,包括水文学法、水力学法、水文—生物分析法、生境模拟法、综合法以及作者参与研究的环境功能设定法等。文章对这些方法的理论基础、优缺点、适用范围进行了重点研究和评述,并结合我国情况分析了其在国内的应用前景。认为水文学法、生境模拟法、综合法和环境功能设定法相对来说都较适合于我国研究,其中生境模拟法由于实施比较复杂,应用性受到一定的限制。     

Effects of regulation on the flow regime of the river Murray,Australia

The flow regime of the River Murray has changed markedly over the last century, and especially the last 50 years, through increased diversions, construction of dams, weirs and levees and changes in operational procedures. A model developed by the Murray–Darling Basin Commission is used to compare simulated natural (unregulated) flows at eight stations with those at seven consecutive stages in the development of regulation. Monthly and annual average flows and coefficients of variation and skewness were computed, and the flow-duration, peak-flow and low-flow characteristics curves plotted. The results confirm that average monthly and annual flows are now considerably lower than those which prevailed under natural conditions. The seasonal distribution of flows has changed in the upper Murray, owing to the influence of dams. Flow-duration characteristics now vary considerably along the river, whereas there was little change under natural conditions. The effect of regulation on flow-duration characteristics is minimal at Albury and becomes more pronounced downstream; it is most apparent in regard to flows exceeded 20–80% of the time. The magnitude of average annual floods (annual exceedance probability 50%) has been reduced by over 50% at all stations, but big floods (average recurrence interval 20 years or more) are little affected. Further, the low flows for a given annual non-exceedance probability are higher under regulated conditions than those under natural conditions. These changes have profound implications for communities of native plants and animals in both riverine and floodplain environments, and also for the long-term utility of the river as a resource.     

变化范围法评估北江流域水文情势变化

通过分析北江石角站实测径流资料,应用变化范围法(RVA)评估北江流域水文情势变化.认为总体上属低改变度到中改变度阶段,个别指标达到高改变度;干支流径流式水库,其枯水期运行调度对北江流域水文情势影响较大,而汛期运行调度对水文情势影响较小;飞来峡水库运行对北江中下游水文情势的改变幅度不大,但个别水文改变指标(IHA)改变度较高,有必要进一步优化飞来峡水库调度方案,减轻对北江河流自然生态的破坏,把IHA改变度降至最低,实现人水和谐.     

水库河道供水对辽河干流水质影响评价

本文通过大量的水质实测资料,分析了辽河干流水质污染状况,评价了水库供水对辽河干流水质状况的影响,指出水质影响评价对辽河干流水环境治理具有重要的指导意义.     

东庄水库水沙特性及渭河下游的影响

通过分析泾河张家山站实测水文资料，得出泾河水、沙年内间的分配关系，最大流量、最大含沙量出现时间及洪水过程的水沙关系等。同时还分析了利用东庄水库如何消除渭河拦门沙、减轻渭河下游防洪负担的途径以及泾河高含沙水流对渭河下游的作用等。     

穿黄工程与河势防洪研究

南水北调中线穿黄工程与河势防洪研究,经历了10多年的时间,由多家科研单位先后开展了现场调查、原型资料分析、数学模型计算,并分别在4座不同比尺的泥沙模型上,进行了不同工况和过河长度方案试验.综合分析其研究成果,可见各家所得的研究成果能相互印证,规律一致;从河势和防洪角度分析,孤柏嘴3 km隧洞方案优于其他方案.     

运用健康生态系统理念治理陡河水库水环境

陡河水库是建于1956年的大型水利枢纽工程。除具有防洪、工农业生产供水功能外．还担负着向唐山市区提供生活用水的任务,也是曹妃甸工业区唯一的水源地．其水质的好坏直接关系到市区每个人的身体健康,关系到当地社会稳定和经济发展。为保护水质,近年陡河水库管理处通过植树种草、投放“食藻鱼”等构建健康生态系统．对改善水库水质起到了积极作用。     

白石水库水情自动测报系统

介绍了白石水库水库自动测报系统的组成及工作原理。本系统是针对国内水情自动测报的现状,将不同国家的设备组合到一起,设计并调试成功了接口电路,采用优化组合的方法,实现了全套进口设备的功能。     

冯家山水库淤积及异重流排沙技术

阐述了异重流排沙技术在冯家山水库排沙减淤工作中的应用,分析了异重流排沙效果及存在的问题,并就减少水库泥沙淤积问题提出了建议,供相关单位参考。     

水库健康调度与河流健康生命探讨

为使水库能改善和维持河流健康生命,达到人水和谐的目的,提出了河流健康调度的定义及内涵,并对其理论、相关措施作了初步探讨,指出新的调度方式可能产生的新问题。     

河库联合调度预报技术探析

贺江流域2013.8暴雨洪水期间,通过准确入库洪水预报,以贺江下游重要城镇安全泄洪量为控制,科学合理利用合面狮水库成功进行调蓄错峰,取得良好的防洪效果,分析了开展河库联合调度预报的技术路线及方法,为广泛开展河库联合调度预报服务提供参考及借鉴。     

金沙河水库除险加固工程设计

金沙河水库建成至今已42年,水库大坝安全鉴定工作中发现：水库防洪标准偏低,主副坝下游坝坡存在集中渗漏和散浸区,溢洪道面板裂缝严重,泄水管(坝下埋管)严重漏水等质量隐患。经过对各种方案的研究提出了相应的工程措施：提高防洪标准的工程措施为坝顶加防浪墙或戴帽加防浪墙的形式;根据下游坝坡集中渗漏和散浸的不同成因和地质条件分别采用旋喷墙和薄壁塑性混凝土防渗墙的新技术进行处理。目前,工程除险加固正在实施中,其加固经验可供类似工程借鉴。     

闹得海水库库区及下游河道的变化

多沙河流上的滞洪水库，能强烈改变水流泥沙过程、水沙搭配关系，将大水泥沙转化为小水泥沙，淤坏河槽，改变泥沙淤积部位，改变河道特性。     

镇扬河段和畅洲汊道近期河势演变分析

长江镇扬河段位于长江下游江苏省境内,上起三江口,下迄五峰山,自上而下分为:仪征水道、世业洲汊道、六圩弯道、和畅洲汊道以及大港水道,河道演变剧烈.主要从分流比、平面形态及河道深槽变化情况,对和畅洲口门控制工程、12 m深水航道潜坝2项工程建成后对该汊道河势演变进行分析.结果表明,2项控制工程对和畅洲汊道左右汊分流比的调节...