Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-06T02:04:59.684Z Has data issue: false hasContentIssue false

The utility of a drought index for assessing the drought hazard in Devon and Cornwall, South West England

Published online by Cambridge University Press:  04 April 2001

Ian D Phillips
Affiliation:
School of Geography, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
and Glenn R McGregor
Affiliation:
School of Geography, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
Get access

Abstract

The utility of a drought severity index, based on accumulated monthly precipitation deficits and a three-monthly initiation and termination rule, for assessing the variability in the timing and severity of the drought hazard between four selected locations in Devon and Cornwall since 1957 is documented. The robustness of the drought events identified is then assessed by changing the index formulation rules. Results indicate that, using a six-monthly, rather than a three-monthly, rule, drought sequences are more difficult to initiate and terminate and are more persistent with a longer mean duration. The drought severity indices are then used to define a hierarchy of significant drought events, isolated in terms of the number of indices simultaneously exceeding an arbitrarily defined severity. Seven Class I droughts, regional in extent, are then discussed; and circulation contrasts between events highlighted using aggregated Lamb weather types. Two drought sub-types emerge, distinguishable according to whether the controlling anticyclone had a greater tendency to be located to the north and east of the UK or to the south and west. A comparative analysis of the ongoing 1995-drought, in terms of its persistence, and rapidity of onset and cessation, is also conducted.

Type
Research Article
Copyright
© 1998 Meteorological Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)