Tanguy, M.; Fry, M.; Svensson, C.; Hannaford, J.

Historic Gridded Standardised Precipitation Index for the United Kingdom 1862-2015 (generated using gamma distribution with standard period 1961-2010) v4

5km gridded Standardised Precipitation Index (SPI) data for Great Britain, which is a drought index based on the probability of precipitation for a given accumulation period as defined by McKee et al [1]. There are seven accumulation periods: 1, 3, 6, 9, 12, 18, 24 months and for each period SPI is calculated for each of the twelve calendar months. Note that values in monthly (and for longer accumulation periods also annual) time series of the data therefore are likely to be autocorrelated. The standard period which was used to fit the gamma distribution is 1961-2010. The dataset covers the period from 1862 to 2015.

This version supersedes previous versions (version 2 and 3) of the same dataset due to minor errors in the data files.

NOTE: the difference between this dataset with the previously published dataset "Gridded Standardized Precipitation Index (SPI) using gamma distribution with standard period 1961-2010 for Great Britain [SPIgamma61-10]" [2], apart from the temporal and spatial extent, is the underlying rainfall data from which SPI was calculated. In the previously published dataset, CEH-GEAR [3], [4] was used, whereas in this new version, Met Office 5km rainfall grids were used (see supporting information for more details). The methodology to calculate SPI is the same in the two datasets.

[1] McKee, T. B., Doesken, N. J., Kleist, J. (1993). The Relationship of Drought Frequency and Duration to Time Scales. Eighth Conference on Applied Climatology, 17-22 January 1993, Anaheim, California.
[2] Tanguy, M.; Hannaford, J.; Barker, L.; Svensson, C.; Kral, F.; Fry, M. (2015). Gridded Standardized Precipitation Index (SPI) using gamma distribution with standard period 1961-2010 for Great Britain [SPIgamma61-10]. NERC Environmental Information Data Centre. https://doi.org/10.5285/94c9eaa3-a178-4de4-8905-dbfab03b69a0
[3] Keller, V. D. J., Tanguy, M., Prosdocimi, I., Terry, J. A., Hitt, O., Cole, S. J., Fry, M., Morris, D. G., and Dixon, H.: CEH-GEAR: 1 km resolution daily and monthly areal rainfall estimates for the UK for hydrological use, Earth Syst. Sci. Data Discuss., 8, 83-112, doi:10.5194/essdd-8-83-2015, 2015.
[4] Tanguy, M.; Dixon, H.; Prosdocimi, I.; Morris, D. G.; Keller, V. D. J. (2014). Gridded estimates of daily and monthly areal rainfall for the United Kingdom (1890-2012) [CEH-GEAR]. NERC Environmental Information Data Centre. https://doi.org/10.5285/5dc179dc-f692-49ba-9326-a6893a503f6e

Publication date: 2017-10-11

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Supporting documentation

Format of the Dataset : NetCDF

Access and use conditions

Licence terms and conditions apply

You must cite: Tanguy, M.; Fry, M.; Svensson, C.; Hannaford, J. (2017). Historic Gridded Standardised Precipitation Index for the United Kingdom 1862-2015 (generated using gamma distribution with standard period 1961-2010) v4. NERC Environmental Information Data Centre. https://doi.org/10.5285/233090b2-1d14-4eb9-9f9c-3923ea2350ff

 

Where/When

Study area
Temporal extent
1862-01-01    to    2015-12-31

Quality

Lineage
SPI is calculated as originally defined in [1]. SPI is based on the cumulative probability of a given rainfall amount occurring at a location. The historic rainfall data of the station is fitted to a statistical distribution. For this dataset, the statistical distribution used is the gamma distribution, which has been extensively used and is recommended as a default choice for Europe by [2]. The L-moments method was used to estimate the gamma distribution parameters, as the maximum likehood method was failing to fit a realistic distribution in some isolated cases. To calculate SPI, the R package SCI was used [3], but modified to use L-moments (instead of Maximum Likelihood). The input data used is the monthly rainfall grids from the Met Office 5km gridded rainfall product. In this version of the dataset (version 2), the monthly rainfall grids from 1960 to 2000 was derived from the Met Office 5-km daily rainfall grids, to address some localised issues that were found in the Met Office monthly rainfall grids.

[1] McKee, T. B., Doesken, N. J., Kleist, J. (1993). The Relationship of Drought Frequency and Duration to Time Scales. Eighth Conference on Applied Climatology, 17-22 January 1993, Anaheim, California.
[2] Stagge, J. H., Tallaksen, L. M., Gudmundsson, L., Van Loon, A. F. and Stahl, K. (2015), Candidate Distributions for Climatological Drought Indices (SPI and SPEI). Int. J. Climatol. doi: 10.1002/joc.4267
[3] Gudmundsson, L. & Stagge, J. H. (2014). Package 'SCI': Standardized Climate Indices such as SPI, SRI or SPEI. Repository CRAN, http://cran.r-project.org/web/packages/SCI/SCI.pdf

Authors

Tanguy, M.
Centre for Ecology & Hydrology
Fry, M.
Centre for Ecology & Hydrology
Svensson, C.
Centre for Ecology & Hydrology
Hannaford, J.
Centre for Ecology & Hydrology

Other contacts

Point Of Contact
Maliko Tanguy
Centre for Ecology & Hydrology
Maclean Building, Benson Lane, Crowmarsh Gifford
Wallingford
Oxfordshire
OX10 8BB
United Kingdom
Custodian
Environmental Information Data Centre
Publisher
NERC Environmental Information Data Centre
Distributor
Environmental Information Data Centre

Spatial

Spatial representation type
Raster
Spatial reference system
OSGB 1936 / British National Grid

Keywords

Topic categories
Climatology / Meteorology / Atmosphere
Other keywords
historic grid
rainfall extremes
drought indicator
SPI
Standardised Precipitation Index
INSPIRE Theme
Meteorological geographical features

Dataset identifiers

https://catalogue.ceh.ac.uk/id/233090b2-1d14-4eb9-9f9c-3923ea2350ff
doi:10.5285/233090b2-1d14-4eb9-9f9c-3923ea2350ff

Metadata

Information maintained by
Environmental Information Data Centre
Last updated
2018-02-13T10:07:46