This paper addresses a typical requirement of real time multiple‐reservoir operation. A methodology is evolved utilizing a form of dynamic programing (DP) for the selection of an optimal reservoir storage policy path through a specified number of policy periods, and a linear programing (LP) routine is used for period by period optimization. The policy periods, in case of the real time operation, correspond to the number of time periods for which a streamflow prediction model is reasonably reliable. The method results in relatively easy computer implementation and high flexibility in that changes in constraints are simply made and additional reservoirs easily added. The method is of considerable value for the determination of release policies in real time operation of an existing system. As an example, application is made to a real system of reservoirs and hydroelectric facilities associated with the Shasta and Trinity sub‐systems of the California Central Valley Project.

This paper introduces the influence coefficient algorithm, a simple, easily implemented, and rapidly convergent computational procedure for the solution of the parameter identification problem in unsteady open channel flow from field observations on stage hydrograph and velocity distribution at one or more points along the channel. (Identification is a mathematical process whereby the parameters embedded in a differential equation defining a system are determined from observations of system input and output.) The parameters specifically chosen for identification are the two ‘friction slope’ characteristics: the channel roughness coefficient and the exponent of the hydraulic radius in the empirical friction slope relation, a number usually assumed to be 4/3. These parameters are not physically measurable and have to be determined from the solutions of the mathematical model using concurrent input and output measurements. This new procedure is related to both quasilinearization and gradient methods. Additionally, an effective formulation of the algorithm is shown to depend on certain stability and convergence features related to the finite difference solutions of the governing flow equations but often ignored or glossed over.

The objective of the study reported herein is to develop practical procedures for the analysis of a multiple purpose, multiple facility reservoir system to guide real time decisions concerning the optimal operation of the system. Application is made to the California Central Valley Project (CVP). The five purposes (benefits), treated as objectives here in the multiobjective optimization, include (1) hydropower production, (2) fish protection, (3) water quality maintenance, (4) water supply, and (5) recreation. The constraint method is used to develop the trade-offs while a specially modified linear programing and dynamic programing algorithm is used for optimization. Noninferior sets can be obtained with each benefit parameterized singly and in various combinations. Two sets of monthly historical streamflows, one set corresponding to a drought year and the other set to an excess water year, are used to develop the corresponding noninferiorOsets. These procedures provide guidance for allocating the total benefits derived from a region's water resources and for operating the available system within all statutory, contractual, and other applicable constraints. A very high degree of decomposition of the typically large multiple purpose, multiple facility operation problem is made possible by the above technique, resulting in a rapid delineation of the noninferior policy set. The decision maker participates at various stages of the analysis and can request more or less detail with regard to the noninferior set. In our opinion, information is best presented to him via a series of two dimensional plots representing various cross sections of the noninferior set. Tabular presentations are not conducive to a good appreciation of the consequences of alternative benefit allocation policies.

No abstract

This paper outlines a method whereby the timing, sequencing, and sizing of a water supply development is validly performed. The method takes care of the vital fact that although it is firm water that is demanded or sold, it is reservoir capacity at a particular site that is costed, and the two are not simply related, nor is the relationship independent of previously constructed reservoirs and the stream‐reservoir configuration. A feature of this method is a simple firm water determination concept that is applicable to any steam‐reservoir configuration and that uses rational and reasonable operating rules at each basic time period for the calculations of reservoir storage changes resulting from excess or deficit streamflows relative to demand in those periods. Details of interchanges of water between reservoirs are not relevant to this concept. Streamflows are taken to be the subnormal flow hydrographs that would correspond to a critical period analysis method, but no advantage is taken of any supposed knowledge about future flows.