WSP07957 - Laserfiche WebLink

Home Browse Search

~ CD L."") r:~l ') . . . CHAPTER III RIVER BUDGET RESULTS annual pickup values. It should be noted that the width of the confidence limits reflects the precision of the estimate, but may not be an indicator of its accuracy. In other words, the width of the confidence band cannot be used to choose the best or "most correct" of the four budgets. The innermost pair of lines straddling the mean in Figure 5 represent the mean annual salt pickups using upper and lower bounds on consumptive use as previously discussed. As can be seen, they lie within the 95 percent confidence limits. Even though there is no reason to believe that the original estimate of consumptive use is incorrect, if it were, the mean pickup would still lie within the confidence limits. Furthermore, in addition, the widest possible ranges for salt pickup resulting from varying the amount of unaccounted flow assigned to each component in the budget lie within the 95 percent confidence limits in the mean. Therefore, it was decided not to make any modification to the estimate of mean annual salt pickup (i.e., 580,000 tons per year). Comparison of Results Table 16 and Figure 9 display the mean annual salt pic~Jp values from the four budgets. Note that if the flow adjustment procedur,a is used there is little difference between the Cisco and State Line budgets. For the sake of comparison, Table 17 and Figure 10 display the mean annual salt pickup values for the period 1952-1974 as estimated by the previously mentioned four budgets as well as the ten USGS methods. The comparison with the USGS estimates is not exactly legitimate because the USGS estimat'as did not include ungaged inflow nor municipal imports. It can be seen that the III-3