The University of Southampton
University of Southampton Institutional Repository

A characterisation of climate variability and trends in hydrological extremes in the Severn Uplands

A characterisation of climate variability and trends in hydrological extremes in the Severn Uplands
A characterisation of climate variability and trends in hydrological extremes in the Severn Uplands
Hydrological and climatic characteristics were investigated within the Severn Uplands to determine the interconnection between variables with a focus on understanding changes in hydrological extremes. Time series of precipitation and flows over a 30-year period were analysed for trends in extremes. The Mann–Kendall (MK) nonparametric test was used to detect trends at six rain gauges and five flow gauges across the catchment. Maxima, percentiles and N-day maxima of precipitation and flow distributions were investigated to identify changes in extreme intensity, frequency and persistence, respectively. Results indicated some significant statistical trends at annual, seasonal, and monthly scales. The largest number of significant trends in extreme precipitation was identified at mountainous gauge locations where significant increases in extreme precipitation persistence were detected annually and during spring and winter. Additionally, significant increases in extreme precipitation frequency were observed annually and during autumn and winter. Trends in flow identified an increase in extreme intensity on an annual basis, as well as during winter and the month of July, and a decrease in extreme frequency at certain stations during spring. Changes in climate variables were investigated to identify causal relationships with precipitation and flow hydrological extremes. Extremes were found to coincide with certain weather types, generally characteristic of cyclonic conditions and/or orographic enhancement. These were largely correlated with strong positive and negative stages of the North Atlantic oscillation, particularly during winter. Snow cover records indicated rapid decline in the Severn Uplands and a reduction in snow indicated a link to changes in spring hydrological extremes. All changes seemed to be driven by the underlying climate variable of air temperature, which coincided with changes in observed national and global temperature records. Hydroclimatological changes indicated a possible temporal shift in the occurrence of extreme hydrological events, which was likely to have been affected by changes in catchment physical properties
1634-1652
Biggs, Eloise M.
f0afed06-18ac-4a4d-841c-36ea4ff8a3b4
Atkinson, P.M.
96e96579-56fe-424d-a21c-17b6eed13b0b
Biggs, Eloise M.
f0afed06-18ac-4a4d-841c-36ea4ff8a3b4
Atkinson, P.M.
96e96579-56fe-424d-a21c-17b6eed13b0b

Biggs, Eloise M. and Atkinson, P.M. (2011) A characterisation of climate variability and trends in hydrological extremes in the Severn Uplands. International Journal of Climatology, 31 (11), 1634-1652. (doi:10.1002/joc.2176).

Record type: Article

Abstract

Hydrological and climatic characteristics were investigated within the Severn Uplands to determine the interconnection between variables with a focus on understanding changes in hydrological extremes. Time series of precipitation and flows over a 30-year period were analysed for trends in extremes. The Mann–Kendall (MK) nonparametric test was used to detect trends at six rain gauges and five flow gauges across the catchment. Maxima, percentiles and N-day maxima of precipitation and flow distributions were investigated to identify changes in extreme intensity, frequency and persistence, respectively. Results indicated some significant statistical trends at annual, seasonal, and monthly scales. The largest number of significant trends in extreme precipitation was identified at mountainous gauge locations where significant increases in extreme precipitation persistence were detected annually and during spring and winter. Additionally, significant increases in extreme precipitation frequency were observed annually and during autumn and winter. Trends in flow identified an increase in extreme intensity on an annual basis, as well as during winter and the month of July, and a decrease in extreme frequency at certain stations during spring. Changes in climate variables were investigated to identify causal relationships with precipitation and flow hydrological extremes. Extremes were found to coincide with certain weather types, generally characteristic of cyclonic conditions and/or orographic enhancement. These were largely correlated with strong positive and negative stages of the North Atlantic oscillation, particularly during winter. Snow cover records indicated rapid decline in the Severn Uplands and a reduction in snow indicated a link to changes in spring hydrological extremes. All changes seemed to be driven by the underlying climate variable of air temperature, which coincided with changes in observed national and global temperature records. Hydroclimatological changes indicated a possible temporal shift in the occurrence of extreme hydrological events, which was likely to have been affected by changes in catchment physical properties

Full text not available from this repository.

More information

Accepted/In Press date: May 2010
Published date: September 2011
Organisations: Geography & Environment

Identifiers

Local EPrints ID: 158873
URI: https://eprints.soton.ac.uk/id/eprint/158873
PURE UUID: 288a4f46-fc2e-464b-9be0-2eb34ae46de2

Catalogue record

Date deposited: 23 Jun 2010 11:44
Last modified: 18 Jul 2017 12:37

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×