21st Century Drought Scenarios for the UK
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A 6-month drought severity index (DSI6) is applied to each of the 11-member perturbed-physics ensemble (HadRM3-PPE-UK) monthly precipitation dataset from 1950 to 2100 to investigate projected 21st century droughts in the UK. Four main drought characteristics are investigated: intensity, drought covariance, frequency of drought months and frequency of drought events at a given duration. Changes in these characteristics are analysed for 30-year periods: 1970–1999 (1980s), 2010–2039 (2020s), 2040–2069 (2050s) and 2070–2099 (2080s) and described in terms of their seasonal behaviour, for both moderate and extreme droughts. Projections of drought characteristics are expressed in the forms of ensemble-mean change relative to the 1980s and model consensus, and analysed over 23 water resource regions. In general, drought characteristics show profound increases (and widespread) for the 2050s and 2080s with larger change occurring during the wet season and under moderate drought conditions. Drought covariance sees greater increase during the dry season with greater change magnitude (but less widespread) under extreme drought conditions. Results also show that droughts can persist over long durations. However, the projected frequency of droughts at longer durations is low compared with droughts with shorter duration of persistence. Water resource regions (WWRs) mostly show negative change in drought characteristics, except for drought covariance. However, intensity and duration of droughts also generally increase over most of the WRRs in England, which are already highly exploited. Of particular relevance to water management, results from this ensemble have a strong influence on dry season water availability, especially in parts of England.
KeywordsDroughts Regional climate model UK UKCP09 Perturbed-physics Ensemble Extreme Uncertainty Consensus
The authors are grateful to the British Atmospheric Data Centre, which is part of the NERC National Centre for Atmpspheric Science (NCAS), for providing access to HadRM3-PPE-UK. Thanks are also due to the UK Engineering and Physical Sciences Research Council (EPSRC) for financial support through the ARCC-Water project and the two reviewers for their feedback on the earlier submitted manuscript.
- Fowler HJ, Kilsby CG (2004) Future increases in UK water resource drought projected by a regional climate model. Hydrol Sci Pract 21st Century 1:15–21Google Scholar
- Jenkins GJ, Murphy JM, Sexton DS, Lowe JA, Jones P, Kilsby CG (2009) UK climate projections: briefing report. Tech. repGoogle Scholar
- Jones RG, Noguer M, Hassell DC, Hudson D, Wilson SS, Jenkins GJ, Mitchell JFB (2004) Generating high resolution climate change scenarios using PRECIS. Tech. rep., Met Office Hadley CentreGoogle Scholar
- Mawdsley J, Petts G, Walker S (eds) (1994) Assessment of drought severity. BHS Occasional Paper No. 3, British Hydrological SocietyGoogle Scholar
- Prudhomme C, Yong A, Watts G, Haxton T, Crooks S, Williamson J, Davies H, Dadson S, Allen S (2011) The drying up of Britain? A national estimate of changes in seasonal river flows from 11 Regional Climate Model simulations. Hydrol Process. doi: 10.1002/hyp.8434
- Rahiz M, New M (2012) Spatial coherence of meteorological droughts in the UK since 1914. Manuscript accepted for publication in AreaGoogle Scholar
- Wade SD, Jones PD and Osborn TD (2007) The impact of climate change on severe droughts: implications for decision making. Technical Report. Environment Agency Science ReportGoogle Scholar