Translated from Gidrotekhnicheskoe Stroitel 'stvo, No. 12, December 2009, pp. 28 -32. Food provision and rationing of the supply are basic factors when preserving a variety of fish species and their populations in a water body.In conformity with effective nature-conserving legislation of the Russian Federation where farming activity is conducted in water entities of piscicultural value, including the operation of hydroelectric power plants, measures should be specified for the preservation of the water entities, biological water resources, and the water regime, and measures should be taken to preserve the habitats of the animal world, and conditions for their reproduction, feeding, and migration paths.Based on the Water Code of the Russian Federation [1] and the Status [2], water resources are utilized in accordance with the Rules of reservoir usage [1]. Organizations operating water-power and water-development works are obliged to ensure filling and drawdown regimes of reservoirs, observing piscicultural demands in sections assuming significance for the preservation and reproduction of fish resources.The Rules for utilization for the water resources of a reservoir represent the principal document on which management of the water regime of a reservoir is based. Dispatcher schedules for structure operation as a function of the water reserve in the reservoir at the time that a decision is made are developed as a component part of these Rules. The punctuality of decision making from several days to one month will depend on irregularity of the water influx to the reservoir, and on the requirements of water consumers as to the operating regime of the structures. A characteristic of water-level dynamics in a reservoirthe rate at which the horizon rises or falls in a specified time interval -is not stipulated on despatchers' schedules. This characteristic assumes critical, frequently determining significance, for both the safety of the water-development works, and also for pisciculture in the reservoirs. Such a position results in noncorrespondence with, and occasionally in contradiction to the reservoir's water-or power-supply demands in a zone of the despatcher's schedule on the one hand, and with respect to the rate at which the reservoir must drawndown to provide this supply on the other. This situation is characteristic when the interests of pisciculture are considered in the requirements for the reservoir's operating regime.In this paper, one approach to development of a regime for the filling and drawdown of reservoirs with consideration of piscicultural requirements is analyzed using the Kovda series of reservoirs as an example.The reservoirs in the Kovda series are referred to as lacustrine reservoirs, and are large water bodies with an overall surface area of 2, 800 km2 at the normal backwater level. These reservoirs are component parts of the White Sea Basin (Kandalaksha Gulf), and are located in the territory of Karelia and the Murmansk Oblast (Fig. 1).The water resources of the Kovda River Basin are util...
The development of the power industry necessit@tes the creation of cascades of hydroelectric stations with reservoirs regulating the streamflow, which are an integral part of power and water-management systems.Streamflow regulation by reservoirs, among which carryover reservoirs are gaining ever greater influence, leads to an increase of the range of variations of the water level in reservoirs during drawdown and filling.During fluctuations of the level between the normal pool (NPL) and dead storage level (DSL), periodic storage and release of groundwaters occur, i.e., the "subsurface" reservoir also participates along with the main reservoir in streamflow regulation.In water-management and hydropower calculations a quantitative evaluation of the interaction of subsurface and surface waters, as a rule, is not taken into account.Qualitatively, the indicated interaction of subsurface and surface waters during fluctuations of the water level in a reservoir related to its drawdown in the low-flow period and filling in the flood period is expressed in the following.During a rise of the water level additional seepage into the bank zone occurs in the form of a groundwater wedge and during falling of the level the part of the water stored in the soil is released into the reservoir.The water-management effect of the operation of the subsurface reservoir can be estimated by means of the water-balance equation used in calculating streamflow regulation in the following form:where Qsti~ is the storage discharge, i.e., the difference between the inflowing Qinij and regulated Wregij discharges; Quseii, Qseepij, Qwdrij, respectively, the discharge being used, s e . . . . eepag discharge, and withdrawals of water from the reservoir; At, duration of the calculated time interval; i, number of the section; j, number of the time interval.With consideration of the interaction of subsurface and surface waters Eq. (I) will take the following form:where Qsubsij is the effect of interaction of the subsurface and surface runoffs.The effect of the interaction of the subsurface and surface runoffs depends on the hydrogeological parameters of the water-bearing rocks (permeability coefficient, hydraulic diffusivity, storage coefficient, etc.).Furthermore, the selection of the scheme of the hydrogeological conditions and method of calculation is important.The dynamics of groundwaters in such a formulation corresponds to a free-surface, unsteady, nonuniform seepage flow.It is necessary to verify that in an examination of the given problem, seepage into the bank strip, which does not enter into the zone of influence of seepage under the retaining structures, is taken into account.In the general case the problem reduces to the solution of a nonlinear differential equation of three-dimensional seepage flow.For the case of flow in a homogeneous bed the equation looks so:Translated from Gidrotekhnicheskoe Stroitei's
A procedure is developed for analysis of scheduled generation at HPP using run-off-forming data relative to water reserves.To organize reliable fuel and energy supply, it is necessary to schedule power generation at hydroelectric plants (HPP) with maximum lead time [9]. The procedures currently used for the scheduling of power generation at HPP are based on data relative to the forecasting of water flow in river basins, or on scheduled generation normally adopted as the average-multiyear value. These forecasts are short-range, since the volume of inflow becomes known with little lead time.The scheduling of power generation in the second quarter for HPP is critical, since scheduling errors will make themselves felt during subsequent operation of the HPP throughout the reminder of the year. Fulfillment of scheduling indicators on the high side for power generation at HPP will result in excessive drawdown of the reservoirs, and inevitable significant losses in generation in subsequent months of the year. In isolated power systems with a predominance of hydraulic capacities, such overestimation is also fraught with disruption in power supply to consumers.Underestimation of power generation at HPP will result in the need to off-load its surpluses to the wholesale market, which cannot always be done considering constraints placed on the regimes of other generating sources.Of the basic factors affecting power generation at HPP in the second quarter, it is proposed that run-off-forming (water locked in snow that has fallen over the entire watershed for site in question) and climatic (characteristic features of atmospheric circulation) factors be utilized.We examined three alternative models: consideration of the individual effect of each of the above-indicated factors on power generation at HPP in the second quarter, and consideration of their combined effect.The goal of this study was to develop a procedure ensuring maximum timeliness in the prediction of power generation with observance of its accuracy requirements.Testing of the procedure was approved for the Rybinsk HPP on the Volga River, and the Votkinsk HPP on the Kama River. Here, annual data on water locked in snow during the period of observance from 1980 through 1998 with a ten-day measurement frequency from January through March, and indicators of characteristic features of atmospheric circulation over the northern hemisphere (from 40°N and higher) from 1980 through 1998 with a monthly measurement frequency were used.The period from 1980 through 1998 was adopted for derivation of a computational model. Estimates of the quality of values forecast for power generation at the HPP in the second quarter were made on the basis of statistical methods for the period from 2002 through 2006.The influence exerted on power generation at the HPP only by the water locked in snow that had fallen over the entire watershed of the HPP sites under consideration was considered in the first alternate structural scheme of the model.Analysis of scheduled power generation was based ...
Translated from Gidrotekhnicheskoe Stroitel 'stvo, No. 10, October 2012, pp. 26 -29. The effect of constraints placed on rate of change of water level in a reservoir on the power-generating performance indicators of a hydroelectric power plant, for example, the Sayano-Shushenskaya HPP, is examined. Variation in power-generating performance indicators of the Krasnoyarsk HHP is determined with use of these constraints placed on the Sayano-Shushenskaya HPP.The safety of water-development works (WDW) of a hydroproject, the population and agricultural entities situated downstream, and the surrounding environment, as well as the operational reliability of the power-generating entity, are determined largely by utilization of the water resources in the reservoir.A characteristic of the dynamics of the change in the water level within the reservoir -the rate at which the horizon ascends or descends in a design time interval on the dispatcher's chart -has gone unregulated. This characteristic, however, assumes importance and frequently decisive significant for the safety of water-development works.Fluctuations of the water level of the reservoir during its service are accompanied by reconfiguration of the stressstrain and filtration states in the mass of the bed. Zones of excess pressure in which failure processes of the mass evolve, may develop during rapid drawdown of the reservoir. Moreover, failure will occur due to intergrowth of large permeable cracks, whereas the concentration of fine cracks remains as before [1]. Also, rapid filling or drawdown of the water level may have an unfavorable effect on the position of the depression curve of an earth-fill (hydraulicked) dam and the banks, resulting in diminution of the safety of the WDW.As a result of manifestation of phenomena exerting a negative influence on the safety of the WDW, the need has arisen for use of certain constraints on the operating regime of the reservoir.It should be remembered that in analyzing the passage of maximum flow rates with a design probability exceeding the limitation placed on the rate of filling of the reservoir, however, these constrains have not been expanded to cover the entire year.Use of constraints on the rate of change of the water level in the reservoir will effect a change in its operating regime, and as a result, a change in the operating regime of the hydroelectric power plant [2]. In turn, a change in the operating regime of a power plant located upstream on the river may influence operation of plants residing downstream. This paper examines the effect of limitations placed on the rate of change of the water level in the reservoir on the power-generating indicators of the plant's performance as exemplified by the Sayano-Shushenskaya HPP, and also evaluates the consequence of use of this constraint on similar performance indicators of the Krasnoyarsk HPP.In addition to flow regulation preferentially for purposes of power generation, the Sayano-Shushenskaya hydroelectric complex is used for demands of water transport, communal...
The Volga-Kama hydraulic power grid comprises 11 large hydroelectric power plants with a total capacity of 11,358 MW, nine of which are in continuous use (Ivan'kov, Uglich, Rybinsk, Gor'ki, Kama, Votskin, Lenin Plant on the Volga, Saratov, and Volgograd). The Cheboksari and Lower Kama hydroelectric power plants are in temporary use, since the parameters of their hydraulic power systems, such as the full reservoir bench mark and the dead storage capacity bench mark, do not meet the designed levels.The Cheboksari hydroelectric power plant is now in operation at a constant reservoir bench mark of 63 m, and the Lower Kama hydroelectric power plant at a bench mark of 62 m. The reservoir performs only daily flow control, which substantially reduces the energy indicators of the hydroelectric power plant.Plans to fill the reservoir to the design levels once the water management facilities have been constructed have encountered objections on the part of local institutions, which have raised a number of standard reasons.Since the facilities of the power grid are not yet complete, it is not possible to meet the design energy indicators of f the hydroelectric power plants or to ensure through navigation with registered depths. According to data collected by Gidroproekt, losses in hydroelectric power amount to 2.70 billion kWh in terms of average long-term yield, 380 MW in terms of rated power, and 1314 MW in terms of the available power for the middle of December. The design analysis aimed at increasing the full reservoir bench marks of the Cheboksari reservoir to 65 m did not lead to positive results in the analyses carried out by the State and Ecology Commissions. Thus, no f'mal decisions have yet been made regarding utilization of the effective capacities of the reservoirs of the Cheboksari and Lower Kama hydroelectric power plants, and it would appear that the hydroelectric power plants will continue to function with reduced bench marks for the next few years.Moreover, new problems have arisen during the time the hydraulic power system has been in operation. These problems, which had to do with economic development on the Lower Volga, had not been encountered previously in the planning process. They were associated with the increased level of the Caspian Sea and with considerable losses suffered by the economies of the Astrakhan and Volgograd districts, districts whose economic health requires flow rates in the range 25,000-28,000 m3/sec. On the basis of data collected by planning organizations, with 1% probability, the flow rate amounts to 40,000 m3/sec, assuming full use of the reserves of the reservoirs. According to results of a study carried out by the FTsP Institute, entitled "Protection Against Flooding and Underfiooding of Cities, Populated Centers, Public Works, and Valuable Land in the Russian Federation," it was estimated that it would cost 1948 million rubles (in 1991 prices) to implement basic engineering and technical measures to protect public works against flooding by flood waters from the Lower Volga Riv...
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