This document summarizes a study of vegetation fire data from 2009-2014 in Greater Manchester, England. It finds that vegetation fire density was highest near urban areas and along river valleys. The driest springs in 2010, 2011, and 2013 saw the most fires. While weather influences fire occurrence, the timing of holiday periods also impacted it. The study defines wildfires using two approaches and finds patterns vary significantly depending on the definition used. Risk is influenced by land cover type and the interface between rural and urban areas.

1. Vegetation Fires 2009 -2014: a GIS study on
adding value to Greater Manchester Fire and
Rescue Service (GMFRS) data – Report
Donlan, R. And McMorrow, J.
Geography, School of Environment, Education and Development,
University of Manchester, June 2015

2. Introduction
The purpose of the report was to review the Incident Reporting System (IRS) data
in relation to the fourteen categories of vegetation fire for four financial years, from
1st
April 2009 to 31st
March 2014. The report is based on the work carried out
during an Applied Study course and my Dissertation for the MSc in Geographical
Information Science at the University of Manchester, 2014.The intention was to
use GIS techniques to differentiate the smaller vegetation fire incidents and the
factors which influence occurrence from the more resource intensive wildfires; then
compare the geography of wildfire in Greater Manchester using two alternative
definitions alongside that for all vegetation fires, looking at how the adoption of a
definition alters the picture. Then focus on the factors of landcover, the interface
between vegetation and urban areas, as well human influence to explain incident
occurrence and predict areas at greatest risk of ignition leading to a set of
reccommendations based on the findings.
Vegetation Fires
The density of all vegetation fires within the Greater Manchester Fire and Rescue
Service (GMFRS) region during the five year period, was highest around the larger
urban areas to the east and west of the city centre, along the Medlock and Irwell
valleys and around Leigh and Wigan. Figure 1 shows the pattern for spring (March-
May) in the driest three years of the five studied. The areas of lowest density were
suburban areas to the south of Greater Manchester and the suburbs of the
northern towns. The areas with little or no density were the rural margins,
especially the western agricultural areas and the upland areas of the Pennines and
Peak District to the north and east, this may relate to low or zero values on the GM
borders. Figure 2 identifies anomalous spring and summer weather over the five
year period. Temperatures anomalies were periods of temperatures exceeding two
degrees above the mean, while Rainfall deficits were periods when rainfall was
less than 50% below the average, which left vegetation more susceptible to risk of
ignition.
When fires occur
There are typically two fire seasons in the UK, spring (March to May) and summer
(June to August). Spring was the most significant season for the GMFRS area,
taking all outdoor fires together (Fig. 3). The relationship between rainfall
anomalies and the number of outdoor incidents was found to be significant,
Fig 1 – Density of outdoor vegetation spring fires for 2010, 2011 &
2013; the driest of the 5 years ( greatest negative rainfall
anomalies shown in Figure 2)

3. Fig 2 - Mean temperature and rainfall anomalies for North West England March
2009 to April 2014, based on averages between 1971 and 2000. Negative rainfall
anomalies (blue bars below the line) are dry periods
showing that spring had below 50% of average rainfall in all three months in 2010
while in 2011 and 2013 rainfall was below average in two months. The summer
only had one month (in 2010) below 50% of the average, with most months having
above average rainfall. Temperature anomalies were less of a factor, with fewer
months exceeding the average; the only two spring months were April 2011 and
March 2012, and July 2013 the only summer month which came close to
exceeding that figure.
How the pattern changes from year to year
The density maps (Fig 1) show the distribution of vegetation fires during the three
worst fire seasons in the IRS record. Spring 2010 had an exceptionally high fire
density, with low rainfall over the whole period. Spring 2011 had two drier months
but low fire density, whereas Spring 2013 was not as dry but had higher density
and shows that factors other than weather are involved. The timing of holiday
periods is a significant factor; an early Easter in the spring of 2010 and 2013
coincided with higher fire density. A later Easter in 2011, which based on weather
alone should have the highest density, but actually had lower density.
Defining wildfires
There are currently two proposed defintions to identify wildfire from other less FRS
resource-intensive vegaetation fires; one based on the Scottish Government’s
Operational Guidance for Wildfire manual of 2013, and another under
consideration by the CFOA Wildfire Group (Table 1). Both use the same IRS data
fields and both also include other criteria not operationally collected for IRS.
CFOA’s category 4 is equivalent to the Scottish manual in the IRS data fields it
uses. Category 5 requires two of these criteria to be met, so are the most
resource-intensive fires for GMFRS.
Fig 3 – Wildfire occurrence 2009-2014 plotted against rainfall anomalies
The number of incidents using both definitions were plotted against below average
rainfall anomalies (Fig 3). Similarly to all outdoor vegetation fires, prolonged
periods of below average rainfall led to larger number of wildfires occurring in the
Spring of 2010 and 2011, then to a lesser extent in Spring 2013. March 2012 had
a peak in wildfires linked to both lower rainfall and higher temperatures, but was
not sustained over the whole spring period. This suggests that the same causal
factors underlie all vegetation fires taken together and just the more resource-
intensive wildfires (using either definition). It is the definition of a wildfire that
dictates the perception of the issue and its importance. It certainly dictates the
geography as Figures 4 and 5 show.

4. Fig 4 – Wildfire Density map for the Scottish Government wildfire manual definition
(IRS-based criteria only), 2009-2014
Density maps were produced using all incidents that met the Scottish Wildfire
definition (Fig 4) and the CFOA Category 5 Wildfire definition (Fig 5) to illustrate
the difference in extent and number for each definition. They can be compared
to the equivalent point density map for all vegetation fires regardless of size or
resources used (Fig 7).
The Scottish definition (Fig 4) shows wildfires concentrated on the edges of
rural uplands of the Pennines and Peak District and farmland in the west. It
also shows a high concentration in the deprived urban areas of east
Manchester, not usually associated with wildfires. The urban incidents are
linked to the number of vehicles and time spent at an incident, rather than the
size of the area burnt; this displays that resources and response to an incident
in urban areas is greater influence on the adoption of a definition, illustrating
that each region has a unique wildfire character and that a definition created for
a rural fire service region produces different results when applied to a more
urbanised region.
Fig 5 – Wildfire Density map using the CFOA Wildfire group category 5 (IRS-based
criteria only), 2009 -2014
The pattern of occurrence for the CFOA Category 5 definition indicates that very
high impact wildfires occur mainly in more rural areas associated with
continuous vegetation linked to agriculture or uplands associated with
agriculture and recreation. These incidents may be larger due to the time taken
to report and respond to these more remote incidents, or where there fewer
resources available.
Data on the over-the-border incidents attended by GMFRS (from the GMFRS
Information Management System) was added to the Scottish definition to produce
a map of the potential extent of wildfire risk beyond the GM Fire Authority boundary
(Fig 6). It shows that wildfire risk is crosses administrative borders and is
associated with urban populations visiting natural areas. The area around the
Lancashire border may provide as high a wildfire risk in the north of the Greater
Manchester Fire Authority as exists in the West Yorkshire and Derbyshire borders
in the east. GMFRS is therefore bounded on two sides by areas of high wildfire
risk. In fact in total there are over four times as many incidents over the border
compared to inside GM. of vegetation fires attended by GMFRS are over-the-
border incidents.

5. Fig 6 – Wildfire Density map for over-the-border Incidents and the Scottish
Government definition of wildfires (IRS-based criteria only), 2009-2014.
Type of land cover burned
A buffer zone of 500m was drawn around each wildfire point to allow for fire
spread. The land cover types in these combined zones are shown in Figure 8. It
provides an estimate of the type of vegetation burned by wildfires. If fire
perimeters were recorded, a more accurate breakdown of land cover and actual
burned area could be provided
For both definitions of wildfire, the largest three land cover types were improved
grassland, arable and horticulture, and rough grassland (Fig 8a & b). None of
these are ‘wildland’ vegetation, but they are all fine to moderate fuels with short
drying times and shorter spotting distances. The largest coarse fuel affected was
broadleaved woodland. The largest vegetation associated with ‘wildland’ areas
was acid grassland. These results reflect the land cover in the GMFRS region, with
no major discrepancy between proportion of land cover and fire occurrence.
Fig 7 Point Density Map for all vegetation fires within Greater Manchester 2009-
2014
The risk of wildfire ignition is linked to the size and shape of the land cover and
how close it is to settlements or roads. Areas of large improved grasslands in
the GMFRS area intermix with urban areas, or agricultural areas intersect with
urban fringes, underlying the importance of the rural-urban interface in wildfire
risk. Wildland areas have much lower levels of human activity, so the risk of
wildfire ignition is lower. However, habitat is an important factor in wildfire
ignition and with a many wildland areas having continuous vegetation areas
exceeding 1,000ha, the risk of escalation of an incident is increased in these
areas from even limited human interaction.
An interface zone between urban and vegetated areas can be identified for Greater
Manchester to show vegetated areas at greatest risk of wildfire ignition. This rural-
urban interface (RUI) broadly falls into two types: peri-urban where settlements
begin to mix with rural areas, and a more rural interface towards the edges of the
region where agriculture and continuous wildland vegetation mix with human
influences and activities; the extent of this interface from the details within figure 9b
and 9c is approximately 500m within the Greater Manchester area.

6. Fig 8 - Vegetation land cover within the wildfire buffer zone (a) Scottish Wildfire
definition (b) CFOA Wildfire definition (c) proportion of Land Cover Map 2007
classes inside Greater Manchester Fire and Rescue Service area.
Fires decrease away from urban areas and roads
The number of wildfires decreases with distance from the urban boundary for
both definitions. Large urban areas make up 43% of the GM area, they are
made up of the urban and suburban areas within Land Cover Map 2007 (fig 9c);
they appear to have a significant influence, with 60% of incidents occuring
within 202m and 80% within 425m (Fig 9a). The large urban areas influence is
due to both their extent and density of population in close proximity to areas of
vegetation. Most incidents occurred within a kilometre, so within easy walking
distance of urban areas and suggest human-caused ignitions.
For the Scottish wildfire definition (Fig 9b), 70% of incidents occurred within 500
metres of the urban boundary, with only 16% occurring over a kilometre away.
The distances were greater for the CFOA Category 5 definition (Fig 9c), but
75% of incidents occurred within 600 metres, with all other incidents occurring
within 1300 metres. These distances display the influence that human activity
and influence has for the majority of wildfire incidents and displays the areas of
greatest risk are situated, which in turn can influence policy on the
prevention of incidents. A-roads also have a strong influence; 60% of
incidents occur within 459m. They extend human access, and thus
ignitions, to more remote and larger wildland vegetated areas, increasing
the number of potential accidental and deliberate ignitions in those areas.
Wildfire Risk
In order to produce a map of potential wildfire risk (Fig 10), the three criteria
which were found to be most significant in explaining wildfire occurrence were
combined on one scale and weighted in turn; they were distance from the urban
vegetation interface, distance from A-roads and population density. It was found
that the weighting of the urban vegetation interface displayed the most
widespread areas of higher risk; for the Scottish wildfire definition 72% of
incidents occurred in the high risk areas and 65% of incidents were captured for
the CFOA category 5 wildfire definition. The results overall show several levels
of wildfire ignition risk. The highest risk is on the margins of Greater
Manchester, especially the Pennines and Peak District and shows the influence
of the A-roads that intersect them and where fuel supply is greater. The medium
risk for the agricultural areas and the edgesof urban areas, where fuel and
human activity are more balanced. The low risk areas are inside the urban
areas where fuel is sparse.
(a)
(b)
)
(c)
)

7. Fig 9 – Decrease in numbers of wildfires with distance from the urban boundary
for (a) all outdoor fires (b) Scottish wildfire definition (c) CFOA wildfire definition.
Fig 10 -Multi-Criteria Evaluation of the risk of wildfire ignition with vegetation
interface weighted
Which wildfire defintion for Greater Manchester?
Figures 4 and 5 show that definitions of wildfire dictate the geography of ignition
risk. This study was based on two definitions (Table 1): the Scottish wildfire
manual, or Category 4 in the proposed categorisation and the CFOA Wildfire
Group definition; and CFOA’s proposed Category 5. Results based on the IRS
data for Greater Manchester display the differences between the definitions and
reinforce the idea that each region has a unique wildfire picture. The Scottish
manual definition identified more incidents but captured many urban vegetation
fires, which it was not designed to do, but did highlight wildfire risk in
surrounding rural areas. The CFOA Wildfire Group category 5 requires a
combination of two factors, so captures fewer incidents, but highlights the areas
at greatest risk from more resource-intensive fires. A combination of these two
definitions appears more appropriate for the GMFRS region, because both were
required to identify key locations of potential wildfire risk where GMFRS
resources are deployed, whether within Greater Manchester or over-the-border.
In practice Category 4 incidents require inclusion with regard to wildfires with
(b)
)
(a)
)
(c)
)

8. regard to size, however the number of vehicles and duration would be need to
be viewed on the effect one had on the other, namely if less than four
appliances led to a longer duration or a less than six hour duration was due to a
large number of appliances responding. The location of an incident and the
resources available are the determining factors as to whether an incident is or
becomes a wildfire as the weather and land cover.
Table 1 –Proposed categorisation of wildfire using IRS, as discussed at CFOA wildfire
Group, June 2014.
Recommendations
1. An agreed definition of wildfire should be adopted so that consistent data can
be collected. It would provide a better understanding of where the risk is
currently highest and how this may change over time. A rolling report could be
run to extract and monitor trends in wildfire incidents.
2. Prevention and preparedness activty should be targetted in the highest risk
areas (Fig 10). Prevention includes existing strategies such as public education
and work with Local Fire Operations Groups, especially with land owners and
land management agencies to manage fuel load and continuity in at-risk
vegetated areas. Preparedness includes siting of wildfire-specifc resources at
Fire Stations closest to seasonal wildfire hotspots, e.g. priority should be given
to Mossley and Littleborough in the east, Ramsbottom and Horwich in the north
and Irlam in the west, as they are closest to the areas of highest risk.
3. Standardise the geolocated point recorded in IRS to improve the accuracy of
GIS analysis. It should be within the fire footprint and preferably at the
estimated point of ignition.
4. A process should ideally be put in place to collect additional data for the
resource-intensive category 5 fires, most critically:
 Fire perimeter to provide, for example, a more accurate estimate of burned
area, types of vegetation burned, and how often fires recurr at a given location
(the current geolocation only gives information only at one point)
 Fire investigation to determine cause and ignition point
 Weather data from the nearest weather station during and in the run up to the
incident to help understand fire behaviour and implications for fire-fighter
safety
 The 0-5 Met OfficeFire Severity Index, or sub-indices such as Fine Fuel
Moisture Code or Initial Spread Index, which are available from the European
Firest Fire Information System (EFFIS,
http://forest.jrc.ec.europa.eu/effis/applications/current-situation/)
This extra data would help build a better understanding of the types of wildfire that
occur in Great Manchester, and the underlying causal factors. It can be used to
inform future prevention and safety strategies.
5. Cross border data sharing on wildfire conditions and fuel availability is crucial.
GMFRS attends over-the-border incidents in large continuous vegetated areas which
cross Fire Authorities, especially in Lancashire, West Yorkshire and Derbyshire, all of
which are areas of high wildfire risk. It is recommended that over-the-border
incidents should be recorded by GMFRS using the IRS data fields, rather than the
present system, irrespective of another Fire Service ‘owning’ the incident and
reporting formallyit to DCLG. It would provide a true picture of the wildfires actually
attended by GMFRS. It would provide a clearer evidence base of wildfire risk for the
wider region to inform resourcing and strategies to manage wildfire risk.
References
Donlan, R. and McMorrow, J. (2015) Vegetation Fires in Greater Manchester: a GIS
study using Incident Recording System data, 2009 -2014 -- Report for Greater
Manchester Fire and Rescue Service. Geography, School of Environment, Education
and Development, University of Manchester.
Available from: http://www.kfwf.org.uk/resources/briefingpapers/ Contacts;
richarddonlan@hotmail.com Julia.mcmorrow@manchester.ac.uk