Assessing areas of extraction
One way to assess the area of peat extraction is by digital mapping using remote sensing technologies. University College Cork (UCC) undertook a study that detected peat soils with little or no vegetative cover. The lack of vegetation indicates that the bog may be undergoing peat harvesting or turf cutting. Other activites that expose peat soils are agriculture, forestry and ovegrazing. The study was completed in November 2010 when the final report was published, and an excel spreadsheet of the exposed peat soils county by county with grid references was generated. A second spreadsheet is being produced which checks the land use for each area of exposed peat soils. This work is at draft stage and is ongoing.
In addition shapefiles of the exposed peat soils were produced. The shapefiles breakdown into three bands eastcoast(July 2006 data), westcoast (August 2003 data)and midlands (October 2003 data) which cover the whole country. Each shapefile requires four files (some are very large) which are contined in a zip file:
The study was done using Landsat images at a 30 m resolution. This means that each pixel represents an area of 30m2. While features such as drainage ditches and small extraction areas of less than 30m2 cannot be easily identified this is a cost effective way of obtaining a national estimate of peat extraction areas.
Following a case study in County Westmeath which involved an extraction area of approximately 200ha with no planning permissions the need for a national assessment became apparent. To assess current knowledge of the extent of peat extraction in the Republic of Ireland FIE wrote to 26 county councils. Offaly County Council had planning records of peat extraction by Bord na Mona. Other than this all replies to date show no records are held by the County Councils.
Leitrim County Council explained the situation with great clarity: ‘The extraction of peat in a new or extended area of less than 10 hectares and the extraction of peat in a new or extended area of 10 hectares or more where drainage of the land commenced prior to the coming into force of the Exempt Development Regulations 2001, is exempt development for the purposes of the Planning Acts under Class 17, Part 3 of Schedule 2 of the Planning and Development Regulations 2001. These exemptions are very generous leaving peat extraction largely outside the planning remit.
No applications for extraction of peat which fall outside these limits have been received by Leitrim County Council. No applications for certificates of Exemption under Section 5 of the Planning & Development Act 2000 have been applied for either. The Planning Authority does not have, nor is required to have, any records of the amount of peat extracted within the county. Neither does it have any details of the areas wherein peat extraction by way of exempt development is being undertaken.
Most of the peat lands in County Leitrim fall within designated Special Areas of Conservation (SAC’s). The National Parks an Wildlife Service (NPWS) may have details of the level of peat extraction within these areas, as peat extraction would be a notifiable activity under the habitats legislation.’
The reply from Limerick County Council raised further concerns relating to designated areas : 'All of the peat extraction activities the Heritage Officer has encountered over the last eight years fall within the exemption parameters. These exemptions also apply within designated areas such as Special Protection Areas'.FIE made an aie request to the NPWS for any records of notifiable peat extraction. Other than for four designated areas no records were held. Furthermore it is not NPWS policy to administer notificaitons. The derogation from the Minister is in evvect givng unconditional permission for domestic turf cutting in desingated areas.
The reply from Cork County Council confirmed the lack of any knowledge of the extent of peat extraction. The Council’s computerised planning system records show that no planning applications have been made to extract peat. 'These records go back to 1991. Peat extraction involving less than 10 hectares is exempt from the requirement to obtain Planning Permission. I regret that as this is the Council’s only potential source of this information, I have no data in relation to peat extraction, and I am unable to grant your request'.
Degraded and disturbed peat soils have a negative impact on water quality. Using GIS the maps can be overlain with maps of water treatment/abstraction points and water treatment plants. This will enable the assessment of level of peat degradation above abstraction points This can then be cross checked against levels of Trihalomethanes (THMS) in potable water. If a direct correlation is indicated as we suspect may be the case as in the UK (Holden et al.) appropriate water source protection measures can be implemented. It must be noted that protection of source is the cheapest and most effective method of ensuring adequate drinking water quality.
The mapping data can also be used to assess the area of peat extraction within areas designated for nature protection.
The level of forestry on peat soil also needs to be ascertained. The Forest Service have FIPS data that should enable forestry to be easily included in the peat land use assessment.