Lecture 2 Reservoir Capacity Yield Analysis
Lectuure 2Reservoir Capaccity Yield Analysis(h(howtto sizei a reserrvoiri andd measure ititsperforrmance)CVEN 5838 Aug 28, 2008
Reservoir Yield: Controolled Release from areservoiri ((or system off reservoirs).i )Often expressed as a ratio of % of mean annnual flow.flow EE.g.,g 70% yield means thereservoir can provide a regulated release ofo 70% of the mean annual flow.The Yield depends on the active storage capacitycof the reservoirReliability of Yield: probability that areservoir will be able to meet thedemand in any particular time interval(usually a year)Reliability Ns/NNs is number of intervals in whichdemand was met; N is the totalnumber of intervalsFirm Yield: can be met 100% of timeCVEN 5838 Aug 28, 2008
Estimating Active Storage CapacityMass Balance Equuation of ReservoirsSt-1 Qt – Rt – Lt StWhereSt-1 is storage at end of previouss time intervalSt is storage at end of current time intervalQt is inflows at current time inteervalRt is release at current time inteervalLt isi lloss ((evap/seepage)/) att currrentt timetiintervali tlReservoirs have a fixed storage caapacity, K, soSt K for each intervalCVEN 5838 Aug 28, 2008
Mass Diagram Anallysis (Rippl) MethodFind the maximum positive cumulative diffeerence between a sequence of preprespecifiedp((desired)) reservoir releases Rt annd known inflows Qt.Record of historical inflows is used, typically40Example: Nine periodperiod-ofof--record flows:35[1, 3, 3, 5, 8, 6, 7, 2, 1]2.3.Plot cumulativesAdd demand lineFind max deficitinflow volumme11.3025Rt 44201510501CVEN 5838 Aug 28, 200823InflowCumulative Inflow45time6789
Mass Diagram Anallysis (Rippl) MethodRepeat the hydrologic sequencee in case critical period is at endStart demand line at full reservoirCalculate ActiveStorage Ka as maxaccumulated storageover 2 successiveperiods of recordCVEN 5838 Aug 28, 2008Rt 44
Mass Diagram Anallysis (Rippl) MethodThe maximum capacity is determmined by the Critical PeriodCritical Drawdown Period:Longest period from fullreservoir condition toemptinessCritical Period:Longest period from fullcondition,ditiththroughhemptiness and to a fullcondition againgCVEN 5838 Aug 28, 2008
Problems with Masss Diagram Method¾Reservoir release needs to be constant (this is notaccurate for monthly intervaal as demands are oftenseasonal)¾Assumes that future hydroloogy is like the past¾Cannot compute storage size for a given reliability¾Evaporation and other losses that depend on level inreservoir cannot be factoredd into analysisCVEN 5838 Aug 28, 2008
Reservoir Planning by Simulation¾Simulation models are basedd on mass balance equationsand take into account all timee-varying processes as well aselevation--based processes ((losses)elevationSimulation based techniquess are called Behavior Analysis¾Why is it difficult to use simuulation for reservoir sizing?¾Another type of “simulation” is based on deficit instead ofstorage.storage This solves some of the simulation problemsproblems.¾Approach is called Sequent Peak AlgorithmCVEN 5838 Aug 28, 2008
Sequent Peeak AnalysisLet Kt be the maximum total storage reqquirements needed; Set K0 0Example: Nine periodperiod-ofof--record flows: [1,[ 3, 3, 5, 8, 6, 7, 2, 1]Apply the equationconsecutively for up to2x the total length ofthe record.The maximum of all Ktis the required storagecapacity for thespecified releases Rtand inflows QtCVEN 5838 Aug 28, 2008
Accounting for LossesEvaporation and Rainfall (net losses) depeend on Surface AreaSurface area depends on storage non linearly:But can be approximated linearly:CVEN 5838 Aug 28, 2008
Accountingg for losses¾Losses can alter the critical pperiod and change the storagecapacity¾NetN t evap ((equations)ti) can bbee includedi l d d iin storagetbbaseddsimulations directly¾LeleLl anddMMontaseritiddevelopel edd methodsth d ffor iincludingl di evapin SPA in an interative approoach(See McMahon et al., Sequeent Peak Algorithm paper onclass website)¾An alternative evapp modelcan be used directly with SPPACVEN 5838 Aug 28, 2008
ReliaabilityReliability (time(time--based) - Ns/NR iliResiliance– SpeedSd off recoveryVulnerabilityy – severityy of failure ((volumetric reliability)y)(Tradeoffs on these 3 lead to very tricky desiggn; several authors have developed indicesthat attempt to combine these (Loucks, 1997; Zongxue, 1998)Reliability and Vulnerability can be integrated into SPA:zzzDetermine number of failure perriods permitted (from reliability)Determine reduced maximum reeduced capacity permitted (fromvulnerability)See example in McMahonCVEN 5838 Aug 28, 2008
Classification of S-Y-P Procedures(Storage – Yieldd – Performance)CVEN 5838 Aug 28, 2008
Behavior Analysis – stoorage based simulation((detailed simulattions of pprocesses))Case 1: Estimate System PerformanceActive capacitypy of reservoir is known.Series of demands is given (could be stochastic).sStarting condition is known or assumed.Historical or synthetic inflows are usedd(could be many traces) (index seqquential or monte carlo)Case 2: Find size of reservoir under conssiderationSeries of demands is known (could bee stochastic)series of inflows is given (historical or ggenerated stochastic)Performance criterion is specifiedEstimate reservoir capacity; do simulations; adjust until get performancedesiredCase 3: Estimate Yield of an existing reseervoirSpecify performance criteria (reliabilityy, vulnerability, maybe resiliance)Use historic or stochastic hydrologyEstimate demand (yield) and iterate unntil meet performance criteriaNeed to know and model detailed operating proceduresCVEN 5838 Aug 28, 2008
Additional important topics¾ Optimizationtechniquesssimple ones can give ideentical results to SPAmore complex methods can include costfunctions¾ Multiple reservoir systemmssingle-reservoir techniques can be extended to multisinglemultireservoir systemsdetermine size at each sitespecify operating policies foor releases and demands(heuristic policies have been developed)typical objective is to keep reservoirs balancedCVEN 5838 Aug 28, 2008
rence between a sequence of prerence between a sequence of pre--d known inflows Q t. y 35 40 25 30 m e R 4 15 inflow volu 20 t 5 10 0 12 345 67 8 9 time Inflow Cumulative Inflow. . emptiness and to a full condition again CVEN 5838 Aug
modesto livermore FREEPORT REGIONAL WATER FACILITY S o u t h . Briones Reservoir Upper San Leandro Reservoir Chabot Reservoir San Antonio Reservoir Reservoir Calaveras Reservoir Crystal Springs Reservoir San Andreas Reservoir Bethany Reservoir . cooking, bathing, filling swimming pools
Introduction of Chemical Reaction Engineering Introduction about Chemical Engineering 0:31:15 0:31:09. Lecture 14 Lecture 15 Lecture 16 Lecture 17 Lecture 18 Lecture 19 Lecture 20 Lecture 21 Lecture 22 Lecture 23 Lecture 24 Lecture 25 Lecture 26 Lecture 27 Lecture 28 Lecture
Reservoir characterization is a combined technology associated with geostatistics, geophsics, petrophysics, geology and reservoir engineering and the main goals of reservoir characterization research are to aid field de velopment and reservoir management teams in describing the reservoir in sufficient detail, developing 3D/4D data for reservoir
environment. To optimize the effectiveness of each reservoir, we must be able to predict the rate of reservoir sedimentation processes, especially reservoir-sediment trap efficiency. Reservoir-sediment trap efficiency is the fraction of the sediment transported into a reservoir that is deposited in that reservoir, usually expressed as a percentage.
Reservoir Characteristics Number of Flowing Fluids in the Reservoir: The mathematical expressions that are used to predict the volumetric performance and pressure behavior of the reservoir vary in forms and complexity depending upon the number of mobile fluids in the reservoir. There are generally three cases of flowing systems:
Small Grains and Grain Sorghum 39 their straw yield as much as on grain yield. In a study we did at DeKalb, we found that straw yield was affected both by plant height and by yield. The formula to predict straw yield based on height and grain yield was as follows: Straw yield (tons per acre) 0.018 grain yield
WATER RESOURCES ENGINEERING-II (A70133) JNTUH-R15 B.Tech IV YEAR I SEM Prepared By: Ms. B. Navya Asst. Professor Department of Civil Engineering . selection of site for reservoirs, zones of storage of a reservoir, reservoir yield, estimation of capacity of reservoir using mass curve-Reservoir Sedimentation-Life of Reservoir. Types of dams .
Reservoir model is yield from integrating the interpret models of different types of information and by engineering software (Sajjadiyan, V.A., 2011). 2.2.2. Reservoir Model Argument The aim of reservoir description is to define a reservoir model which shows the dynamic and static information of the reservoir.
