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<br /> <br />f'.) <br />I-" <br />c.c <br />W <br /> <br />this river is not of great significance to a study of the entire <br />basin and since it flows directly into Lake Mead, no attempt was <br />made to refine its correlation properties. <br /> <br />In addition to preserving the correlation among flow stations, it <br />was also considered important to ascertain that the modeling procedure <br />maintained the relationship between flow and quality at a given sta- <br />tion. This was checked by computing the simple correlation coeffi- <br />cients between flow and quality at selected stations for both a <br />historic and a synthetic trace. Four stations were chosen for <br />examination with the results shown in table 5. <br /> <br />The correlation between synthetic flow and quality of the Colorado <br />River at Cisco and the Gunnison River at Grand Junction is signifi- <br />cantly smaller than the historic data show. This discrepancy results <br />since the coefficients used to define quality parameters were derived <br />using less effort than the flow coefficients and could be in error. <br />It should be understood that the generated data in the sequences <br />being described here may not reproduce the quality of streamflows <br />with a high degree of confidence. <br /> <br />4.4.2 Total Streamflow <br /> <br />The total flow passing a gaging station should be well duplicatedin <br />the synthetic hydrology data set. As a measure of this quantity, the <br />monthly flow was accumulated to produce a mass curve of flow. To <br />make comparisons over several years of flow records, sets were created <br />from two 30-year synthetic traces. This provided five traces of <br />60 years' duration, These traces were then directly compared to <br />present modified data representing 1912 to 1971 streamflows. In <br />figures 4 through 8 of the July 1974 report, synthetic and the present <br />modified flow sequences are plotted on the same graph. The plots <br />show a close similarity between present modified and synthetic data <br />with the exception of the Archuleta station. The lower synthetic <br />values are partly a result of reflecting San Juan-Chams diversions <br />in the generated flows. <br /> <br />Table 6 of the July 1974 report presents the mean annual flows at <br />five key stations. The present modified values are those which reflect <br />the 1914-65 base period described in Appendix 1. The values for each <br />of the 10 synthetic traces were found by analysis of the generated <br />data. The values in the table indicate the model is reproducing the <br />long-term mean flow. As expected, synthetic means are both above and <br />below the expected mean (or "population" mean) and tend to cluster <br />about it. <br /> <br />30 <br />