Statistical characterization and trend analysis for Tennessee and Clinch River flows at Chickamauga and Norris dams

Long-term linear trends in calculated natural riverflow data and the methods used for their detection were investigated for the Clinch River at Norris Dam and the Tennessee River at Chickamauga Dam.

Riverflow records at Norris Dam, available from 1903 to 1989, were validated against the flow data of two unregulated tributary rivers to Norris Lake.

Step and monotonic trends were sought in the flow record, step trends with the t-test, monotonic trends with linear regression and seasonal Kendall tests.

No statistically significant step or long-term linear trends were found in the annual, monthly, and maximum and minimum annual data sets. Long-term linear decreasing trends were detected in some individual months of record.