peatland monitoring iucn conference v.4
TRANSCRIPT
Monitoring Peatland Degradation and Recovery Using Satellite Radar. Case Study: Irish Midlands
Overview Map (Sentinel-1)• Differential interferometric synthetic aperture radar
(DInSAR) satellite remote sensing techniques have been used for many years to measure land surface motion.
• One major restriction is that they generally do not work so well over vegetated areas.
• We have solved that problem by developing the ISBAS technique which can survey all terrains.
• Overcoming this restriction has opened up the possibility of monitoring Peatland continuously over large areas with DInSAR.
• To illustrate the potential we have surveyed all peat bogs within a large area in the Irish Midlands
• Using recent Sentinel-1 data and archive ENVISAT data we compare surface motion during the periods 2015-2016 to 2002-2009.
• Three lowland raised bogs within the area illustrate the potential of this technique.
D. Large1; D. Gee²; A. Sowter²; A. Novellino²; P. Bhatia21University of Nottingham, UK; 2Geomatic Ventures Limited, UK
Key Observations
Clara Bog – Peatland Collapse
1991-20023
• Intensifying subsidence reported3 from W Clara Bog 1991 – 2002 as a result of drainage into underlying aquifer.
2002-2009 • Slow sustained subsidence, most
notable in W Clara Bog2014-15 • Well defined area of rapid subsidence
in W Clara Bog focussed on the Western soakaway
• Stabilisation and uplift in the central Clara Bog.
• Patterns of surface motion appear to be strongly linked to drainage.
Application:• Could be used to revise restoration
potential and strategy
Abbeyleix Bog – Response to Drain Blocking
Key Observations
Late 1980s• Drainage ditches created
2009• Drainage ditches blocked
2002 – 2009 • Peat surface subsiding. maximum
rate SW of disused railway line.
2014-15 • Rapid uplift of the peat surface along
a N-S line, just W of the disused railway line.
Issues to be addressed: • Link between mechanical, response,
gas flux, cause of uplift and the integrity of the peat structure
Knockahaw Bog – Uplift of a Degraded Raised BogKey ObservationsLate 1980s• Drainage ditches created4
2002-2009• S and E subsiding. NW stable2013• Bord na Mona note “no infilling of
drains with the exception of a couple of drains that had begun to become infilled around and within the flushes and in the NW section”. 4
2014-15 • Rapid uplift of the peat surface in NW
of bog and upstream of flushes. • Minimal changes to drainage appear
to have had a major influence on water retention and uplift.
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Abstract Area of Interest
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References and acknowledgements:1. Drainage for Clara acknowledges LIFE14NATIE000032.2. Drainage provide by Bord na Mona3. Heggler et al 2005, Subsidence of Clara Bog West...
Rapport 121 Wageningen University4. Knockahaw rehabilitation plan, Bord na Mona