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<br />001 ()53 <br /> <br />PRINT - <br /> <br />Prints tables of flow and salt data. <br /> <br />STATISTICS - Computes statistics of annual values. <br />5.5 Use of Stochastic Data <br /> <br />The CRSS has the capability to use stochastic hydrology inflow data in <br />place of the historically derived data normally used. Although only <br />limited use has been made of stochastically generated hydrology data in <br />CRSS studies, the potential for wider use exists and the added effort <br />required to generate a series of stochastic traces is often worthwhile. <br /> <br />Stochastic hydrology offers the capability to assess the impacts of <br />operational and water use changes under a wide variety of equally likely <br />hydrologic sequences. For example, the 78-year record used in the CRSS <br />model offers one set of events by which management policies can be <br />assessed. However, stochastic hydrology allows for the generation of a <br />much wider variety of equally likely traces which still preserve key <br />statistical properties of the historical record. The results of a <br />modeling study using 20 or more stochastically generated 78-year traces <br />(which still preserve the key statistical properties of the historical <br />record) would generally provide a broader range of operating character- <br />istics than results of a mOdeling study which relied exclusively on the <br />historical record. <br /> <br />An example of a study which used stochastic hydrology data is the study <br />"Alternative Operating Strategies for Distributing Surplus Water and <br />Avoiding Spills." This study utilized the CRSS package with a com- <br />bination of historical and stochastic hydrologic traces to evaluate the <br />effects of alternative operating strategies on reservoir content and <br />releases, power generation, water quality, deliveries to various water <br />users, and other parameters of interest. Monthly stochastic flow and <br />salt values were generated using several computer programs written spec- <br />ifically for that study, but which could easily be modified for use in <br />other studi es. <br /> <br />The LAST (Lane's Applied Stochastic Techniques) computer package sup- <br />ported by the Bureau of Reclamation can also be used to generate <br />stochastic traces from historical record sets. The LAST package creates <br />annual and seasonal stochastic values while preserving statistical pro- <br />perties and correlations of the historical data set. The stochastic <br />values can then be transformed into the format needed for input to the <br />CRSM. More information is available on the LAST package in the Bureau <br />of Reclamation's Applied Stochastic Techniques User's Manual. <br /> <br />24 <br />