Variability of hydrological droughts in the conterminous United States, 1951 through 2014

Scientific Investigations Report 2017-5099
By: , and 

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Abstract

Spatial and temporal variability in the frequency, duration, and severity of hydrological droughts across the conterminous United States (CONUS) was examined using monthly mean streamflow measured at 872 sites from 1951 through 2014. Hydrological drought is identified as starting when streamflow falls below the 20th percentile streamflow value for 3 consecutive months and ending when streamflow remains above the 20th percentile streamflow value for 3 consecutive months. Mean drought frequency for all aggregated ecoregions in CONUS is 16 droughts per 100 years. Mean drought duration is 5 months, and mean drought severity is 39 percent on a scale ranging from 0 percent to 100 percent (with 100% being the most severe). Hydrological drought frequency is highest in the Western Mountains aggregated ecoregion and lowest in the Eastern Highlands, Northeast, and Southeast Plains aggregated ecoregions. Hydrological drought frequencies of 17 or more droughts per 100 years were found for the Central Plains, Southeast Coastal Plains, Western Mountains, and Western Xeric aggregated ecoregions. Drought duration and severity indicate spatial variability among the sites, but unlike drought frequency, do not show coherent spatial patterns. A comparison of an older period (1951–82) with a recent period (1983–2014) indicates few sites have statistically significant changes in drought frequency, drought duration, or drought severity at a 95-percent confidence level.

Suggested Citation

Austin, S.H., Wolock, D.M., and Nelms, D.L., 2018, Variability of hydrological droughts in the conterminous United States, 1951 through 2014: U.S. Geological Survey Scientific Investigations Report 2017–5099, 16 p., https://doi.org/10.3133/sir20175099.

ISSN: 2328-0328 (online)

ISSN: 2328-031X (print)

Study Area

Table of Contents

  • Abstract 
  • Introduction
  • Methods of Study
  • Variability of Hydrological Droughts, 1951 Through 2014 
  • Comparison of Findings from This Study with Findings from Previous Investigations
  • Limitations 
  • Summary and Conclusions 
  • Acknowledgments 
  • References Cited

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Variability of hydrological droughts in the conterminous United States, 1951 through 2014
Series title Scientific Investigations Report
Series number 2017-5099
ISBN 978-1-4113-4205-7
DOI 10.3133/sir20175099
Year Published 2018
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Virginia Water Science Center
Description Report: v, 16 p.; Data release
Country United States
Online Only (Y/N) N
Additional Online Files (Y/N) N