Spatiotemporal variability of meteorological droughts in southeastern USA

• Published in: Natural hazards (Dordrecht) 2017-04, Vol.86 (3), p.1007-1038
• Main Authors: Mitra, Subhasis, Srivastava, Puneet
• Format: Article
• Language: English
• Subjects: Benchmarking; Civil Engineering; Climate change; Drought; Droughts; Earth and Environmental Science; Earth Sciences; Environmental Management; Equivalence; Evapotranspiration; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Meteorology; Natural Hazards; Original Paper; Precipitation (meteorology); Seasons; Spatial analysis; Trend analysis; Trends
• ISSN: 0921-030X; 1573-0840
• DOI: 10.1007/s11069-016-2728-8

Droughts in the southeast USA have been linked to economic losses and intractable water conflicts. The region has witnessed several severe droughts events during the period from 1901 to 2005. In this study, spatiotemporal variability in meteorological drought characteristics in the southeast were analyzed using two different datasets by the means of standard precipitation index and standard precipitation evapotranspiration index for the period 1901–2005 for agricultural and non-agricultural seasons. The study periods were divided into three epochs 1901–1935, 1936–1970, and 1971–2005 and drought characteristics, in terms of severity, frequency, number, and trends were analyzed. Additionally, areal extent, drought severities and return periods associated with three severe drought years 1904, 1954, and 2000 were analyzed. Except for the state of Florida, results indicate decrease in drought severity during the recent epoch of 1970–2005 in the study domain. Trend analysis confirms that the study domain has become wetter over the last 105 years. Wetting trends were more prominent in the agricultural season. Additionally, droughts seem to have migrated from the western part of the study area encompassing the states of Alabama, Tennessee, Louisiana, and Mississippi to the Florida panhandle region during the recent epoch. Droughts exhibited higher spatiotemporal variability during the agricultural season compared to the non-agricultural seasons. Results also showed that early to mid-1950s experienced some of the most severe droughts in the study domain. Some of the drought events, such as the drought of 1954 and 2000, have been equivalent to a 100-year drought event in the southeast. The results from this study form the benchmark for studying the impacts of future climate change projections on meteorological droughts in the southeast.