Parry et al 2016 HESS - systematic evaluation of drought termination in the UK.pdf (6.42 MB)
A systematic assessment of drought termination in the United Kingdom
journal contribution
posted on 2016-11-25, 13:38 authored by Simon Parry, Robert WilbyRobert Wilby, Christel Prudhomme, Paul WoodPaul WoodDrought termination can be associated with dramatic transitions from drought to flooding. Greater attention may be given to these newsworthy and memorable events, but drought terminations that proceed gradually also pose challenges for water resource managers. This paper defines drought termination as a distinctive phase of the event. Using observed river flow records for 52 UK catchments, a more systematic and objective approach for detecting drought terminations is demonstrated. The parameters of the approach are informed by a sensitivity analysis that ensures a focus on terminations of multi-season to multi-year droughts. The resulting inventory of 467 drought terminations provides an unprecedented historical perspective on this phenomenon in the UK. Nationally and regionally coherent drought termination events are identifiable, although their characteristics vary both between and within major episodes. Contrasting drought termination events in 1995-1998 and 2009-2012 are examined in greater depth. The data are also used to assess potential linkages between metrics of drought termination and catchment properties. The duration of drought termination is moderately negatively correlated with elevation (irsg‰Combining double low lineg‰ĝ'0.47) and catchment average rainfall (irsg‰Combining double low lineg‰ĝ'0.42), suggesting that wetter catchments in upland areas of the UK tend to experience shorter drought terminations. More urbanized catchments tend to have gradual drought terminations (contrary to expectations of flashy hydrological response in such areas), although this may also reflect the type of catchments typical of lowland England. Significant correlations are found between the duration of the drought development phase and both the duration (irsg‰Combining double low lineg‰ĝ'0.29) and rate (irsg‰Combining double low lineg‰0.28) of drought termination. This suggests that prolonged drought development phases tend to be followed by shorter and more abrupt drought terminations. The inventory helps to place individual events within a long-term context. The drought termination phase in 2009-2012 was, at the time, regarded as exceptional in terms of magnitude and spatial footprint, but the Thames river flow record identifies several comparable events before 1930. The chronology could, in due course, provide a basis for exploring the complex drivers, long-term variability, and impacts of drought termination events.
Funding
This research was funded through the Learning & Development programme at the Centre for Ecology & Hydrology (CEH), as well as the Natural Environment Research Council’s (NERC) “Analysis of historic drought and water scarcity in the UK” (NERC grant ref.: NE/L01016X/1) and “Improving predictions of drought to inform user decisions (IMPETUS)” (NERC grant ref.: NE/L010267/1) projects.
History
School
- Social Sciences
Department
- Geography and Environment
Published in
Hydrology and Earth System SciencesVolume
20Issue
10Pages
4265 - 4281Citation
PARRY, S. ... et al, 2016. A systematic assessment of drought termination in the United Kingdom. Hydrology and Earth System Sciences, 20, pp. 4265-4281.Publisher
Published by Copernicus Publications on behalf of the European Geosciences Union. © Author(s)Version
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/Acceptance date
2016-09-05Publication date
2016Notes
This is an Open Access Article. It is published by Copernicus Publications on behalf of the European Geosciences Union under the Creative Commons Attribution 3.0 Licence (CC BY). Full details of this licence are available at http://creativecommons.org/licenses/by/3.0/.ISSN
1027-5606eISSN
1607-7938Publisher version
Language
- en