Examination of Changes in Annual Maximum Gauge Height in the Continental United States Using Quantile Regression

Abstract

This study focuses on the detection of temporal changes in annual maximum gauge height (GH) across the continental United States and their relationship to changes in short- and long-term precipitation. Analyses are based on 1,85 U.S. Geological Survey records over the 1985–215 period and are performed using quantile regression. Trends were significant only at a limited number of sites, with a higher number of detections at the tails of the distribution. Overall, there is only weak evidence that the annual maximum GH records have been changing over the continental United States during the past 3 years, possibly due to a weak signal of change, large variability, and limited record length. In addition to trend detection, the extent to which these changes can be attributed to storm total rainfall and long-term precipitation was also assessed. The findings of this study indicate that temporal changes in GH maxima are largely driven by storm total rainfall across large areas of the continental United States (east of the 1th meridian, the West Coast). Long-term precipitation accumulation, on the other hand, is a strong flood predictor in regions where snowmelt is an important flood-generating mechanism (e.g., northern Great Plains, Rocky Mountains), and is overall a relatively less important predictor of extreme flood events.