NZ Survey Arc Chords

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Creative Commons Attribution 4.0 International

You may use this work for commercial purposes.

You must attribute the creator in your own works.

6487
115
Updated
29 Mar 2020

This dataset was last updated on LINZ Data Service on 29 Mar 2020.

This layer provides all authoritative arc survey observations and is targeted at cadastral surveyors.

Only observations that have been captured in Landonline are available. This includes vectors that were re-captured in the Survey Capture Areas from survey plans lodged prior to Landonline and all survey observations since.

Individual cadastral surveys will commonly re-measure or re-use cadastral lines. Often they will be the same, however as the accuracy capability has increased over time, differences between 'old' and 'new' observations are more likely. Thus all survey observations include the reference to the Survey Plan.

Layer ID 50778
Data type Vector linestring
Feature count 324306
Primary key id
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

NZ SPI Adjustments

Licence

Creative Commons Attribution 4.0 International

You may use this work for commercial purposes.

You must attribute the creator in your own works.

6377
84
Updated
29 Mar 2020

This dataset was last updated on LINZ Data Service on 29 Mar 2020.

This layer provides the extents of the data incorporated into an adjustment which has been completed as part of the Spatial Parcel Improvement (SPI) project. The SPI project aims to improve the accuracy of digital cadastral data in areas (primarily rural) where survey-accurate data does not currently exist. The improvement of coordinates is controlled by a mathematical adjustment process using a Least Squares methodology. The adjustment/integration process results in increased mapping accuracy of surrounding spatial objects (e.g. parcels), the effect of which is some new observations or parcels appear to move. The extent of the change largely depends upon the accuracy of the underlying data. In general, movements will be at least several metres, as the SPI project targets areas where significant movements are expected.

Layer ID 50835
Data type Vector polygon
Feature count 394
Primary key id
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

NZ WACA Adjustments

Licence

Creative Commons Attribution 4.0 International

You may use this work for commercial purposes.

You must attribute the creator in your own works.

6527
76
Updated
29 Mar 2020

This dataset was last updated on LINZ Data Service on 29 Mar 2020.

This layer provides the extents of the data incorporated into an adjustment which has been completed as a Wide Area Cadastral Adjustment (WACA). These adjustments are undertaken in areas where there is already substantial survey-accurate data, but there are some inconsistencies in the data resulting from small changes to geodetic control coordinates and/or the progressive submission of additional Cadastral Survey Datasets (CSDs). The improvement of coordinates is controlled by a mathematical adjustment process using a Least Squares methodology. The adjustment/integration process results in increased mapping accuracy of surrounding spatial objects (e.g. parcels), the effect of which is some new observations or parcels appear to move. The extent of the change largely depends upon the accuracy of the underlying data. In general, movements will be no more than 10cm, as the WACAs target areas where coordinates already have fairly high spatial accuracy.

Layer ID 50836
Data type Vector polygon
Feature count 4331
Primary key id
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed

Canterbury Earthquake Survey Mark Movements

Licence

Creative Commons Attribution 4.0 International

You may use this work for commercial purposes.

You must attribute the creator in your own works.

5699
121
Added
12 Sep 2016

This dataset was first added to LINZ Data Service on 12 Sep 2016.

This layer details the movement of survey marks due to the Canterbury Earthquake Sequence (CES). The movements include the impact of 5 major earthquakes on 4 September 2010, 22 February 2011, 13 June 2011, 23 December 2011 and 14 February 2016.

Note that these movements apply only at the survey mark. Nearby land may have moved differently, especially in areas impacted by substantial shallow ground movement.

For further earthquake information, see the Canterbury earthquake information on the LINZ website.

Scope

Movements do not include the regular tectonic movement (not related to earthquakes) of approximately 5cm per year.

As well as Christchurch, the data covers Lyttelton, Spencerville, Kaiapoi, Pines Beach, Woodend, Pegasus and Waikuku Beach.

Mark Movement Calculations

Observed mark movements have been calculated from geodetic and cadastral survey data collected at the same physical survey mark before and after the earthquakes. Various filters have been applied to ensure as far as practicable that the movements reflect real-world earthquake-related movements of marks. For example, only non-boundary marks that have been directly measured (rather than adopted) are included.

Modelled mark movements have been calculated using models of the tectonic-scale movements resulting from each earthquake, supplied by GNS Science, supplemented with more detailed modelling carried out by LINZ. These models typically represent deep-seated movement only. They do not include shallow movement, such as that resulting from liquefaction.

Therefore the difference between the post-earthquake observed and post-earthquake modelled position generally represents shallow ground movement. The difference between the post-earthquake modelled and pre-earthquake observed position generally represents deep-seated movement. The difference between the post-earthquake observed position and pre-earthquake observed position represents total movement due to the earthquakes.

Accuracy

The uncertainty of the coordinate changes is 0.1m at a 95% confidence interval.

Layer Attributes

  • nod_id_post_eq: Landonline node id for the latest post-earthquake node (mark)
  • code_post_eq: Geodetic code for the latest post-earthquake node
  • name_post_eq: Mark name for the latest post-earthquake node
  • nod_id_pre_eq: Landonline node id for the pre-earthquake node (mark)
  • code_pre_eq: Geodetic code for the pre-earthquake node
  • name_pre_eq: Mark name for the pre-earthquake node
  • de_mod_obs: East change from modelled post-earthquake to observed post-earthquake position
  • dn_mod_obs: North change from modelled post-earthquake to observed post-earthquake position
  • hz_mod_obs: Horizontal change from modelled post-earthquake to observed post-earthquake position
  • bg_mod_obs: Bearing from modelled post-earthquake to observed post-earthquake position
  • de_pre_mod: East change from observed pre-earthquake to modelled post-earthquake position
  • dn_pre_mod: North change from observed pre-earthquake to modelled post-earthquake position
  • hz_pre_mod: Horizontal change from observed pre-earthquake to modelled post-earthquake position
  • bg_pre_mod: Bearing from observed pre-earthquake to modelled post-earthquake position
  • de_pre_obs: East change from observed pre-earthquake to observed post-earthquake position
  • dn_pre_obs: North change from observed pre-earthquake to observed post-earthquake position
  • hz_pre_obs: Horizontal change from observed pre-earthquake to observed post-earthquake position
  • bg_pre_obs: Bearing from observed pre-earthquake to observed post-earthquake position
Layer ID 53455
Data type Vector point
Feature count 8882
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed
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