monitoring ground subsidence in support of planning ... · slide 4 . how we can help current...

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

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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

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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

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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%

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Example Mixed Rural/Urban Brownfield Site: Isle of Grain

-8mm/year 8mm/year

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Example Mixed Rural/Urban Brownfield Site: London Gateway

8mm/year -8mm/year

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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

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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