Modeling the Yield–Evaporation–Spill in the Reservoir Storage Process: The Regulation Triangle Diagram

From the dimensionless reservoir water budget equation, a graphical method to model the yield–spill–evaporation loss trade-off in the reservoir storage process was built. The reservoir inflows were transformed into three parts that sum to the total mean inflow for long-term operation: evaporation, spill and yield. A regulation triangle diagram (RTD) has been proposed to provide a better understanding of the reservoir storage process as a function of reservoir capacity, hydrological river regime, evaporation and reservoir morphology. The inflows were assumed to be serially uncorrelated and to originate from a Gamma probability distribution function. The diagrams were developed using the Monte Carlo method, while the graphics were developed for intermittent rivers with a coefficient of variation of annual inflows that ranges from 0.6 to 1.6. In the model, the reservoir is a single over-year system, and the values are referenced to the steady state conditions.     

The Volga: Management issues in the largest river basin in Europe

The Volga is the longest river in Europe and 16th longest in the world. The riverine landscape of the Volga is of exceptional scientific and economic importance to Russia; the basin contains approximately 40% of the Russian population and relates to 45% of the country's industrial and agricultural produce. The Volga River drains an area of 1.4 million km², covering various biomes from taiga to semidesert. Anthropogenic impacts in the 20th century include pollution as well as hydropower production and navigation purposes, incurring a cost for its historically important migratory fish (e.g., sturgeons) and related fisheries. River basin management in Russia, since 2006, is based on the water code that determines federal competencies in water management. Extensive water quality monitoring programmes provide feedback to regional managers. Monitoring of biological parameters is spatially limited and should be extended in order to provide sufficient data for informed management. Some initiatives have been implemented in recent decades in order to restore the ecological health of the river and manage fisheries resources (e.g., restocking programmes and the definition of total allowable catches). As recreational fishing is popular but presently unregulated in Russia, we suggest additional monitoring. Finally, the headwaters and lower river floodplain of the Volga have remained as free‐flowing and relatively undisturbed systems. Because reference conditions with low levels of anthropogenic disturbance cannot be found in Central European lowland rivers, both the headwaters and lower Volga floodplains below Volgograd are of great importance on European level.     

流域水库群水资源调度系统开发及应用

构建了流域水库群水资源调度系统。该系统采用框架结构,与GIS无缝连接并利于添加模型;内嵌GIS控件面轻松实现图形导航、放大、缩小、漫游、标注、图层控制管理;采用分布式流域水文预报模型有效解决了山区降雨分布不均匀问题,提高了水情预报精度。通过2009年＂莫拉克＂台风降雨过程的霍童溪流域水库群预报调度计算表明：流域水库群水资源调度系统的应用可提高水资源利用率。     

三峡水库2003年蓄水对长江中下游水情影响分析

三峡工程经过近10 a的建设于2003年6月上旬蓄水至135 m,工程进入围堰发电运行期,10月由于航运等方面的需要,水库第2次蓄水至139 m.水库蓄水减少了上游来水,使中下游的水情发生了相应的变化,其变化也引起了社会各界的关心.根据三峡水库的蓄水情况,对2003年三峡水库蓄水期间长江中下游主要站螺山、汉口、大通站水位、流量进行研究,分析三峡水库蓄水对长江中下游水情的影响.     

三峡水库蓄水运行后荆江河道特性变化研究

由于三峡水库的蓄水运行、上游建库和水土保持工程的逐步实施,三峡水库入库泥沙量和出库泥沙量均出现大幅减少,坝下游河道将在较长时期内产生较大幅度的沿程冲刷,荆江河段首当其冲.根据三峡水库蓄水运行后荆江河段实测资料,分析了荆江河道特性变化情况,并结合数学模型计算成果,从河型、河势和河床形态等方面对荆江河道特性变化趋势进行了预估.研究结果表明:三峡水库蓄水运行后,荆江河段河道特性总体不会有重大改变,但各河段河势将在长时期内有不同程度的调整,河势调整过程中相应岸段崩岸在所难免.为保障荆江的防洪安全,维护健康长江,促进人水和谐,针对本河段河道特性的变化情况,提出了应对建议和措施.     

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.     

三峡工程运用初期荆江河段调关弯道冲淤演变试验研究

三峡水库修建后,由于水库调蓄作用,进入坝下游荆江河道的水沙过程发生了显著变化。荆江河道产生较明显的冲刷,已引起局部河段的河势调整,将在相当长时期内对两岸堤防、已建护岸工程和河道整治工程及河道的稳定产生不同程度影响,进而影响该地区的防洪、航运、生态与环境,以及河流的综合服务功能的正常发挥。采用长江防洪实体动床模型试验,研究了三峡工程运用初期不同时期荆江重点险工段调关弯道的冲淤变化过程,并在此基础上预测河势调整趋势。研究成果可为该段河道的治理和河势控制工程规划、设计等提供技术参考。     

Minimizing environmental impact whilst securing drinking water quantity and quality demands from a reservoir

Complying with the demands of drinking water supply whilst minimizing environmental impact poses a great challenge in water management. This study investigates the potential of withdrawal management of drinking water reservoirs to alleviate the disruption of the river continuum by a reservoir dam with respect to temperature and discharge. The aim is the identification of an optimal withdrawal strategy to provide a near‐natural discharge temperature and flow for the downstream river without jeopardizing drinking water production. First, we identify the applicability of new withdrawal regimes for raw water security and downstream river demands. Second, we search for an ideal withdrawal regime in scenario simulations using a numerical reservoir model (“General Lake Model”). The scenarios on a drinking water reservoir in Germany demonstrate that we are able to derive an optimized reservoir management. The numerical model is provided for operators as a simple and efficient tool for optimizing the withdrawal strategy within reservoir management.     

Discharge pulses of hydroelectric dams and their effects in the downstream limnological conditions: a case study in a large tropical river (SE Brazil)

To address daily fluctuations in electricity demands, the quantities of water passing through the turbines of hydropower plants can vary significantly (up to fourfold) during a 24‐h cycle. This study evaluates the effects of hourly variations in water discharges on the limnological conditions observed in two below‐dam river stretches. The study reservoirs, Capivara and Taquaruçu, are the 9th and 10th reservoirs in a cascade of dams in the Paranapanema River in south‐east Brazil. The reservoirs exhibit different trophic conditions, water retention times, thermal regimes and spillway positions. Capivara Reservoir is deeper, meso‐eutrophic, with a high water retention time and hypolimnetic discharges (32 m) varying between 500 and 1400 m³ s^?1. In contrast, Taquaruçu Reservoir is relatively shallow, oligo‐mesotrophic, and has a low retention time, with water discharges varying between 500 and 2000 m³ s^?1. Its turbine water intake zone also is more superficial (7 m). For two periods of the year, winter and summer, profiles of limnological measurements were developed in the lacustrine (above‐dam site) zones of the reservoirs, as well as in the downstream river stretches (below‐dam site). In both cases, the sampling was carried out at 4‐h intervals over a complete nictemeral cycle. The results demonstrated that the reservoir operating regime (water discharge variations) promoted significant differences in the conditions of the river below the dams, especially for water velocity, turbidity, and nutrient and suspended solids concentrations. The reservoir physical characteristics, including depth, thermal stratification and outlet structure, are also key factors influencing the limnology and water quality at the below‐dam sampling sites. In the case of Capivara Reservoir, for example, the low dissolved oxygen concentration (<5.0 mg L^?1) in its bottom water layer was transferred to the downstream river stretches during the summer. These study results demonstrated that it is important to continue such investigations as a means of verifying whether or not these high‐amplitude/low‐frequency variations could negatively affect the downstream river biota.     

基于水文学与水力学方法的雅砻江水情预报模型

以雅砻江官地水库至河口为对象,建立一个基于水文学与水力学方法相耦合的水情预报模型。其中,官地水库出流作为模型入流边界,官地水库至二滩水库河道汇流采用马斯京根河道演算法模拟;官地水库至二滩水库区间入流采用基于栅格的新安江模型模拟,以使模拟结果具有一定的预见期;二滩水库按水库调度规则计算水库出流;二滩水库至河口对完全圣维南方程组采用一维非恒定流隐式差分求解,模拟出沿河道任意断面水情过程,从而使具有预见期的水文预报成果沿河道方向得到了延伸,实现了对二滩水库至河口段水情的精准预报和过程控制。采用2007—2009年日系列资料对模型进行严格的率定与验证后发现,小得石站最高水位的绝对误差均小于0.3 m,桐子林站最大流量的相对误差均小于10%,日模拟的确定性系数均高于0.989,高精度的模拟结果证实了模型的合理性和有效性。     

水位变化下膨胀土岸坡渗流场和稳定性分析

河水位的升降变化对含裂隙的非饱和膨胀土岸坡稳定性有着显著的影响。水位的变化引起岸坡内地下水位的变化是非饱和到饱和的过程。运用非饱和渗流理论,模拟了在河水位升降过程中膨胀土岸坡暂态渗流场的变化,分析水位变动时孔隙水压力的变化,同时对某岸坡进行了稳定性评价,研究了在水位变化以及裂隙深度变化条件下的岸坡稳定性。结果表明:水位升降对岸坡内部渗流场的影响具有明显的分带性,在经过水位变化过程后,岸坡稳定性有降低趋势,且岸坡表层的裂隙对稳定性的影响没有水位变化的影响大。     

The effect of Keepit Dam on the temperature regime of the Namoi River,Australia

Modifications to water temperature caused by the release of hypolimnetic water from thermally stratified reservoirs pose a major threat to the aquatic biota of lowland rivers in Australia's Murray–Darling basin. Keepit Dam is earmarked as one of several deep‐release structures in the basin causing ecologically significant temperature modification over a large length of river. This study utilized discrete and continuously monitored historical water temperature data from stream gauging stations, together with reservoir thermal profile data, to assess the impacts of Keepit Dam on the thermal regime of the Namoi River. Modifications to selected components of the river's annual temperature cycle were quantified in relation to a pre‐dam temperature regime estimated from statistical models incorporating catchment, hydrological and sample attributes. Keepit Dam has modified the thermal regime of the Namoi River. The effect was greatest immediately downstream from the dam where the annual maximum daily temperature was approximately 5.0 °C lower and occurred three weeks later than the pre‐dam condition. This change was sufficient to disrupt thermal spawning cues for selected Australian native fish species. The magnitude of disturbance progressively diminished with distance from the dam. Key aspects of the river's annual temperature cycle were largely restored to the pre‐dam condition within 100 river km downstream from the dam, which is closer than previous estimates. However, there was marked inter‐annual variation in the magnitude of thermal modification and ecological impact as a result of year to year changes in tributary flow and reservoir behaviour. Copyright © 2002 John Wiley & Sons, Ltd.     

水库运用对河流水文情势影响的IHA法评价——以伊河陆浑水库为例

水流是河流生物环境的主要决定因素之一,影响生物群落组成及其多样性。水利工程会改变河流天然径流过程,研究河流的水文情势具有十分重要的意义。基于龙门镇水文站实测流量数据,采用IHA法就陆浑水库运用对伊河径流过程的影响进行了评价。结果表明,陆浑水库的运用对龙门镇水文站水文年极值出现时间变化的影响不大,而对月流量、年极值、频率、延时和变化率指标改变显著,明显改变了下游河道水文情势,对下游河道内的水生态环境产生了较大影响。     

From a continuous thermal profile to a stepped one: The effect of run of river hydropower plants on the river thermal regime

Both reservoirs and run of river power plants affect the thermal regime of rivers but despite the higher number of the latter few studies have focused on their effect. In this study, we investigated the water thermal regime of Serio River (Northern Italy), a subalpine river regulated by a reservoir and characterized by a cascade system of run of river power plants. Water temperature has been monitored continuously for more than 4 years at the extremes of 4 stretches subjected to water diversion and thermal alterations have been quantified. Our results show that hydroelectric power plants act locally causing a considerable thermal alteration that increases with the distance from the diversion weir. Indeed, within the by-passed stretch, the rate of warming doubles the natural gradient (0.47°C/km vs. 0.19°C/km annually) with peaks in summer (0.73–0.90°C/km on average). By contrast, the run of river power plants keep the water temperature almost constant in the diversion channels. Thus, a cascade system of run of river plants shifts the overall riverine thermal regime from a continuous to a “stepped” longitudinal profile. Results highlight that the thermal effects of run of rivers plants are not negligible and should be considered and monitored continuously. Since there are thousands of hydropower plants powered by flowing waters it is time to consider their thermal impacts in environmental flow policies and bioassessment programs.     

The Hydrological Status Concept: Application at a Temporary River (Candelaro,Italy)

In achieving the final objective of the European Water Framework Directive, the evaluation of the ‘hydrological status’ of a water body in a catchment is of the utmost importance. It represents the divergence of the actual hydrological regime from its ‘natural’ condition and may thus provide crucial information about the ecological status of a river. In this paper, a new approach in evaluating the hydrological status of a temporary river was tested. The flow regime of a river has been classified through the analysis of two metrics: the permanence of flow and the predictability of no‐flow conditions that were evaluated on monthly streamflow data. This method was applied to the Candelaro river basin (Puglia, Italy) where we had to face the problem of limited data availability. The Soil and Water Assessment Tool model was used when streamflow data were not available, and a geographic information system procedure was applied to estimate potential water abstractions from the river. Four types of rivers were identified whose regimes may exert a control on aquatic life. By using the two metrics as coordinates in a plot, a graphic representation of the regime can be visualized in a point. Hydrological perturbations associated with water abstractions, point discharges and the presence of a reservoir were assessed by comparing the position of the two points representing the regime before and after the impacts. The method is intended to be used with biological metrics in order to define the ecological status of a stream, and it could also be used in planning the ‘measures’ aimed at fulfilling the Water Framework Directive goals. Copyright © 2014 John Wiley & Sons, Ltd.     

Strategy for phytoplankton studies in inland water bodies subject to cultural eutrophication

In this article basic approaches to phytoplankton studies in eutrophication‐impacted water bodies are reviewed. Assessments of nutrient loading and chlorophyll ‘a'‐total phosphorus relationships are made for the Kuibyshev reservoir, a model water body in the research work of the Institute of Ecology of the Volga River Basin of the USSR Academy of Sciences. The phytoplankton's response to fluctuating nitrogen and phosphorus concentrations has been studied using field observations as well as in experiments with a continuous ‘group culture’. Particular attention is given in this article to methodological aspects of such studies.     

调水背景下丹江口水库优化调度与效益分析

针对南水北调中线一期工程建成调水这一新常态下丹江口水库调度问题,从丹江口水库蓄水、供水、发电等不同运行任务出发,通过设定弃水最小化、发电量最大化调度目标函数和不同供水调度情景,建立了丹江口水库优化调度模型,构建满足丹江口水库调度运行方式的求解空间,采用1956—2015年丹江口天然入库径流系列,运用较成熟的动态规划优化算法对丹江口优化调度进行模拟,研究水源地枢纽丹江口水库不同调度目标函数和运行方式对下游区域水文情势和供需水平衡的影响,试图为提出可权衡汉江流域多方用水需求的丹江口调度运行方式提供基础支撑。结果表明:考虑南水北调中线一期工程引水后,采用丹江口优化调度方案的下泄水量>272亿m³,能够满足下游基础供水需求。     

三峡工程运用初期上荆江杨家脑至郝穴河床冲淤变化试验研究

三峡水库修建后,由于水库调蓄作用,进入坝下游荆江河道的水沙过程发生了显著变化,荆江河道产生较明显的冲刷,已引起局部河段的河势调整,将在相当长时期内对两岸堤防、已建护岸工程和河道整治工程及河道的稳定产生不同程度影响,进而影响该地区的防洪、航运、生态与环境以及河流的综合服务功能的正常发挥.利用长江防洪实体动床模型试验研究了...     

三峡水库坝下游河道反应与治理对策探讨

受三峡水库蓄水拦沙影响,坝下游河道将发生长距离、长时期的调整,并引起河势调整、崩岸增加、枯水位下降、荆江三口分流减少等河道反应,需采取科学的应对措施。介绍了国外关于均衡河流与优良河道形态的描述,引入传统五行系统观,分析了比降、流速、床沙、悬沙、水深5个因子的循环激励与制约关系,阐述了河流演变系统自动调整与再平衡过程。为应对河道反应,提出了河道整治与崩岸治理、水库优化调度、河道监测与分析研究等对策,探讨了河道治理原则和典型河段治理思路,建议采用护底加糙、口门改道、潜坝限流等整治措施,以期为坝下游河道保护与治理提供参考。     

小浪底水库运用初期游荡性河道整治应与挖河固堤相结合

小浪底水库运用初期，改变了下游来水来沙条件，游荡性河段将普遍遭受冲刷，尽管河床下切可以促进河道稳定，但还不能摆脱横河、斜河等畸形河势的威胁，近期黄科院开展的游荡性河道挖河固堤模型试验结果表明，在游荡性河段只要挖河方案可行，可以达到规顺河势的目的，小浪底水库运用初期下泄清水为游荡性河道局部河段采用挖河方式规顺河势创造了条件，因此这期间游荡性河道整治应与挖河固堤相结合，在局部河段实施挖河疏浚，以促进游荡性河段河道的稳定。