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3.5.3 Other Non-Numeric Calibration Targets <br />Other information will be used to evaluate model calibration. These are termed non-numeric <br />criteria for the purposes of this TM, since they will not be included as part of tlne model <br />calibration objective function. Each of tlne following targets will be evaluated using engineering <br />judgment to assist in identify>ing the best combination of model >lnput parameters. hn some cases <br />the targets will be evaluated against quantitative metrics, discussed in Section 4.1. <br />• Random geographic distribution of head, streamflow and stream ga>ln/loss residuals <br />• Comparison of simulated and observed diversions <br />• Number and location of flooded and dry cells <br />• Correspondence between simulated and mapped areas of groundwater <br />evapotranspiration <br />These types of data are not readily suited for automated parameter estination techniques. <br />Some of the targets listed above are estimated or derived values that have a higher level of <br />uncertainty than the measured parameters of water level (head) and streamflow. In addition, <br />most of tlne targets listed above are affected by changes in head and streamflow, so including <br />them in the automated parameter estimation process would be redundant. These non-numeric <br />targets will provide another means to evaluate how well calibrated is a given model rtun. They <br />are considered a lower priority than tlne targets used in tlne automated parameter estimation <br />process described in previous sections but still important elements of the model calibration. <br />3.6 Development of Target Database <br />Water level and stream flow data used lln the calibration and validation processes resides iln <br />HydroBase and will be extracted and processed unto a format suitable for use in the calibration <br />process. The stream gain/loss >lnformation will be compiled from the Task 46 TM. The data <br />used for calibration will >lnclude: <br />Water elevation observations at specified well locations, <br />Streamflow observations at specified streamflow gaging stations, <br />Stream gain/loss. <br />4.0 Calibration Criteria <br />The objective of tlne calibration process is to obta>In acceptable agreement between model <br />calculated values and their correspond>ing measured values. Tlne calibration process <br />systematically varies model parameters within predeternnined ranges based on site data and <br />engineering judgment to obtain this agreement. Typically, the model parameters with the <br />greatest uncertainty, includ>nng those that are not easily measured or can have significant spatial <br />variability (such as aquifer hydraulic conductivity) are used for adjustment iIn calibration. The <br />input parameters that will be adjusted during tlne calibration process are discussed in Section 2. <br />Calibration criteria are defined in this TM as tlne threshold values used to deternnine wlnetlner <br />the model is sufficiently accurate. The criteria are the maximum differences between simulated <br />P~ SPDSS T~8 2 Final TM 10-08-0t~.doc 15 <br />