Managing the dynamics of the New

Zealand spatial cadastre

Don Grant1, Chris Crook2, Nic Donnelly2

1 RMIT University

2 Land Information New Zealand

• The immediate problem – Canterbury earthquakes

• The generic problem – a multidisciplinary issue - who owns what?

• The legal/regulatory cadastral survey response

• The geophysical/geodetic/spatial response

• Limitations of the recently applied deformation model

Overview – Cadastral dynamics

RMIT University©2011 Research @ Locate14 – Canberra 7-9 April 2014 2

Canterbury earthquakes 4 September 2010

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Impact on cadastral boundaries:

a recently surveyed “straight” boundary

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Movement due to lateral spreading as a result of liquefaction -

the wall and house were previously adjacent

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Boundary peg appears to be undisturbed but it has moved 2.8 metres

due to lateral spreading as a result of liquefaction

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A multi-disciplinary problem

How do deep crustal processes impact on the

legal rights of ordinary people to their land?

Who do you go to for an answer to this question?

a. Geophysicists?

b. Lawyers?

c. Surveyors?

d. Spatial scientists?

e. All of the above?

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A multi-disciplinary problem

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Solid Earth

Geophysics

Land

Law

Cadastral

Surveying Geodesy

Fault Plane

Model

Reference Frame

& Point Motions

Reference Frame

Motions

Higher density

local movement

Legal

evidence

Case Law

Legal opinions

Remote sensing

Spatial data

management

Science Law

Surveying & spatial science

Body of Knowledge

Deformation of cadastre - scenarios

Movement

Category

Spatial

variation

Temporal

variation

Parcels

distorted?

Boundary

moves?

Spatial model

Tectonic

motion

Continuous -

broad scale

Continuous -

near linear

No Yes Datum deformation

model

Earthquake -

remote

Continuous -

broad scale

Instantaneous

+ post-seismic

No Yes Deformation patch

Earthquake -

near field

Continuous Instantaneous

+ post-seismic

Near linear

(affine)

Yes Deformation patch

Earthquake -

rupture zone

Discontinuous Instantaneous

+ post-seismic

Non linear Yes? Interpolate across

rupture, resurvey

Landslip /

Rockfall

Discontinuous Instantaneous No No Not modelled

Liquefaction Generally

discontinuous

Instantaneous Yes & No? No? Not modelled

Water boundary

avulsion

Continuous

but localised

Instantaneous No No Not modelled

Accretion &

erosion

Continuous

but localised

Continuous -

slow

Yes Yes Updated following

survey

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Amended Rules for Cadastral Survey

Changes to “straight” boundaries

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Horizontal and Vertical Displacements

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Total Displacements from all Earthquakes

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InSAR interference pattern –

Darfield earthquake

Each coloured

fringe represents

1.5 cm of ground

displacement in

line-of-sight to the

satellite

Incoherent

regions indicate

ground damage

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Fault Plane Model (J Beavan, GNS Science)

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Fault plane solutions for major aftershocks

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Changes to NZGD2000 coordinates

Landonline updates

7,876,563

coordinates

2,215,410 nodes

2,745,690 lines

543,787 parcels

48,629 roads

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Match of model and measured movements

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Detailed coordinate adjustments

- Model vs reality

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Complexity of the fault trace

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Fault plane model deformation contours

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Discrepancy between model

and surface trace

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Physical Fault Trace

Modelled surface

Expression of

Fault

Questions?

(There will be more to discuss on this and other earthquake

related survey/spatial topics at the

FIG2016 Working Week in Christchurch, 2-6 May 2016)

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