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<br />". .: <br /> <br />~ <br /> <br />'.// <br /> <br />A theoretical bank storage curve was developed from <br />given by Ferris, Knowles, Brown, and Stallman (1962); <br /> <br />1ST <br />Qs = 0.0692 So ~ <br /> <br />an equation <br /> <br />(1) <br /> <br />in which Qs is bank storage for both sides of the stream in cubic feet <br />per second per mile, So is the abrupt change of stage in the stream in <br />feet, S is the storage coefficient, T is transmissivity in square feet <br />per day, and t is time in days since the abrupt change of stage occurred <br />in the s~ream. Increases in stream stage result in positive values of <br />So and Qs which indicate water entering bank storage; water will leave <br />bank storage when the stream stage declines. Water leaving bank storage <br />will be discussed in the section on the recession following reservoir <br />releases. <br /> <br />To estimate the transmissivity (T) near Salida, the observed bank <br />storage rate (Qs) at time t, so' and an assumed S, were used in equation <br />1 for elapsed times (t) ranging from 5 minutes to 21 hours. The average <br />T by this method, and the assumed value of S used in its derivation, <br />were then tested using two other equations given by Ferris, Knowles, <br />Brown, and Stallman (1962): <br /> <br />s = So <br /> <br />[1 - <br /> <br />2 <br />;; <br /> <br />x <br />t 2/Tt/s <br /> <br />e-u2duJ <br /> <br />soD(u)h <br /> <br />(2) <br /> <br />. <br /> <br />and <br /> <br />u2 <br /> <br />x2S <br />4Tt <br /> <br />(3) <br /> <br />in which x is the distance of the well from the stream in feet, s is the <br />observed change of head in the well in feet, and D(u)h is the compli- <br />mentary error function which is given for calculated values of u2. <br />Equations 1 and 3 test T and S because equation 1 evaluates the product <br />ST and equation 3 evaluates the ratio S:T. Using this trial and error <br />method of evaluating T and S in conjunction with the observed bank <br />storage rate, the average transmissivity in the vicinity of Salida was <br />estimated to be 4,760 ft2 (feet squared) per day (35,600 gallons per <br />day per foot) and the storage coefficient to be 0.15. <br /> <br />Equation 1 shows that bank storage is proportional to so, the stage <br />change in the river. In the preceding analysis of observation well data, <br />So was determined from staff gage readings at each site. To extend the <br />bank storage relationship for different antecedent river conditions and <br />release discharges, the expected change in river stage was evaluated on <br />the basis of miscellaneous mainstem discharge measurements and the stage- <br />discharge relationships at mainstem gaging stations. <br /> <br />'. <br /> <br />16 <br />