monitoring ground subsidence in support of planning ... · slide 4 . how we can help current...
TRANSCRIPT
SLIDE 1
Monitoring Ground Subsidence In Support of Planning &
Remediation Geomatic Ventures Ltd
Paul Bhatia, CEO
SLIDE 2
About GVL
Incorporated in July 2015 Using breakthrough technology from the
University of Nottingham We provide high precision ground motion
surveys › Relative motion to mm accuracy › Long term trends › Changes over time
SLIDE 3
Introduction
Reports on subsidence are crucial to develop and re-develop land Long term subsidence can be a root
cause of ongoing issues & can be indicator of potential future problems Land-motion is dynamic & so
continuous monitoring can lead to new insights
SLIDE 4
How we can help
Current reports provide information on: › Natural ground subsidence › Coal Mining › Ground water flooding etc.
Based on a variety of information sources that include interpretations of geology and historical records We provide information on actual
ground motion - and this can be used to gain new insights
SLIDE 5
Our UK Map of Ground Motion
Average rate of motion Oct 2015-Oct 2017
Results are colour-coded
SLIDE 6
Example Mining Subsidence Leigh, Greater Manchester
-8mm/year 8mm/year
Note uplift (blue) due to groundwater rebound Subsidence (red) due to mine collapse
SLIDE 7
Example Made Ground Little Packington, Warks
-8mm/year 8mm/year
Subsidence (red) due to landfill collapse
SLIDE 8
GVL Products Making the News
SLIDE 9
How do we produce these maps?
Sentinel 1a and 1b Radar Imaging Satellites, 6 day ground repeat over UK, 693km altitude, 98.6 min orbital period
SLIDE 10
How do we produce these maps
ISBAS (Intermittent Small Baseline Subset method) is a radar image processing technique developed by the University of Nottingham that gives good results over all classes of land cover ISBAS algorithms can currently provide
average land-motion results over time periods of 3 months or more
SLIDE 11
Our UK Land Map
Uses freely available data from the Sentinel-1 satellite Applies a Patent Pending algorithm to
survey urban AND rural areas alike Provides average velocity over a two-
year period Spatial Resolution = 90m (approx) Pixel Spacing = 50m Typical standard error = 2mm/year
SLIDE 12
Our UK Land Map
Provides access to actual land-subsidence measured across the UK Can be licensed from GVL providing
cost-effective access to subsidence information for reports and projects Is produced using remote sensing
data and requires no physical access to the land
SLIDE 13
What About Coverage?
Urban and Major Infrastructure GB All of the UK land
surface is covered Other satellite
surveys cover urban and infrastructure subsidence only › This covers about 6%
of the total land cover We survey this AND
the remaining 94%
SLIDE 14
Example Mixed Rural/Urban Brownfield Site: Isle of Grain
-8mm/year 8mm/year
SLIDE 15
Example Mixed Rural/Urban Brownfield Site: London Gateway
8mm/year -8mm/year
SLIDE 16
Example Mixed Rural/Urban Brownfield Site: Castleford
-8mm/year 8mm/year
SLIDE 17
T1 T2 T3 T4
T1 T2 T3 T4 Relative height change (mm)
25 0 -25
Other Bespoke Products: Time Series
SLIDE 18
Conclusion
Our technique is able to provide subsidence data over all terrain types Our survey of the UK is on the web for
anyone to browse at: www.geomaticventures.com Please don’t take our word for it – see
for yourself! GVL provide information on actual
ground motion - and this can be used to gain new insights
SLIDE 19
Thankyou! Geomatic Ventures Ltd
Paul Bhatia, CEO