Tagged: New Zealand

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

For further information about this dataset, see the Canterbury earthquake information.

Coordinates computed by adding the effects of deep-seated movement to survey points that had authoritative survey-accurate digital cadastre (SDC) coordinates immediately prior to 4 September 2010 (the first Canterbury earthquake). Marks that did not have SDC status at that time are not included in the dataset. Deep-seated movements were evaluated using the NZGD2000 deformation model.

• The 'nod_id' column is the Landonline node id. This is the unique identifier for the mark.
• The 'current_name' column is the Landonline mark name. Many boundary marks do not have a name recorded in this dataset, because this information has not been digitally captured.
• The 'east_mtpleatm2000' and 'north_mtpleatm2000' columns are the east and north coordinates (metres) in terms of the Mt Pleasant 2000 transverse mercator projection. Rounded to the nearest centimetre.
• The 'coord_order' column is the Landonline coordinate order immediately prior to 4 September 2010.

The estimated absolute uncertainty of these coordinates is 0.09m at the 95% confidence level.

These coordinates are intended for the use of Licensed Cadastral Surveyors when locating boundaries in Christchurch, in accordance with the Rules for Cadastral Survey 2010 and associated guidance, particularly guidance relating to the earthquakes.

For further information about this dataset, see the Canterbury earthquake information.

Coordinates computed by adding the effects of deep-seated movement to survey points that had authoritative survey-accurate digital cadastre (SDC) coordinates immediately prior to 4 September 2010 (the first Canterbury earthquake). Marks that did not have SDC status at that time are not included in the dataset. Deep-seated movements were evaluated using the NZGD2000 deformation model.

• The 'nod_id' column is the Landonline node id. This is the unique identifier for the mark.
• The 'current_name' column is the Landonline mark name.
• The 'east_mtpleatm2000' and 'north_mtpleatm2000' columns are the east and north coordinates (metres) in terms of the Mt Pleasant 2000 transverse mercator projection. Rounded to the nearest centimetre.
• The 'coord_order' column is the Landonline coordinate order immediately prior to 4 September 2010.

The estimated absolute uncertainty of these coordinates is 0.09m at the 95% confidence level.

These coordinates are intended for the use of Licensed Cadastral Surveyors when locating boundaries in Christchurch, in accordance with the Rules for Cadastral Survey 2010 and associated guidance, particularly guidance relating to the earthquakes.

This layer provides all authoritative bearing and distance survey observations which form part of the cadastral survey dataset

Only observations that have been captured in Landonline are available. This includes observations 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.

This dataset only contains right-line survey observations. A small fraction of the total number of survey observations are defined as arcs and are provided via the Survey Arc Chords layer.

This layer provides all cadastral parcel polygons and some associated descriptive data that details the appellation (legal description), purpose, size and a list of titles that have an interest in the parcel.

NOTE: This layer contains primary and non-primary approved, current or historic linear parcels (see status flag descriptions for more information).

In conjunction with the Linear Parcels, this layer provides the easiest way to create a relationship with associated tables such as Parcel Title Association List, Parcel Statutory Actions List and Survey Affected Parcels List.

This layer contains spatial and non-spatial (without geometry) parcels. The Landonline system which manages the data maintains non-spatial parcels for many different reasons. The non-spatial parcels can only be accessed via WFS or as a full layer file download. No layer clips can be used. The most common reasons for non-spatial parcels are:

1. Flats and unit survey plans will create non-spatial parcels for referencing property rights. This is because the Landonline system has not yet been designed to support the spatial definition of these plans.

2. Titles which were not linked to a spatial parcel during the Landonline title conversion project created non-spatial parcel references. As titles are spatially linked many of these non-spatial parcels will be made historic or will be merged with the associated spatial parcel.

Parcels within this layer contain the following status flags:

• Approved: The definition of a survey-defined parcel that has been processed and authorised as correct in terms of the survey network.

• Current: A parcels that has been registered or the parcel is made current by a statutory action against a Legalisation plan.

• Survey Historic: A parcel that has been extinguished from the primary cadastral network but still exists in live Title estates.

• Historic: A parcel that has been extinguished from the primary cadastral network and no longer exists in live Title estates or has an current recorded statutory action. Typically this happens when a parcel is subdivided or merged, and new titles or actions are registered against the replacing parcels. Note: Only parcel made historic since the beginning of Landonline operations (2002) are included.See this page for the actual dates when Landonline operations started.

Polygons within this layer have a nominal accuracy of 0.1-1m in urban areas and 1-100m in rural areas. For more detailed information about parcel accuracies please refer to the Survey Boundary Marks layer which contains accuracies for each parcel node.

The originating data for parcel/title associations includes some non-official sources where the official data does not support a link. For more information see.

This layer provides all linear parcels (e.g. Centreline easements) and their associated descriptive data as a single layer to facilitate their use independently of the all polygon parcels.

NOTE: This layer contains primary and non-primary approved, current or historic linear parcels (see status flag descriptions for more information).

In conjunction with the Parcels, this layer provides the easiest way to create a relationship with associated tables such as Parcel Title Association List, Parcel Statutory Actions List and Survey Affected Parcels List.

This layer contains spatial and non-spatial (without geometry) parcels. The Landonline system which manages the data maintains non-spatial parcels for many different reasons. The non-spatial parcels can only be accessed via WFS or as a full layer file download. No layer clips can be used. The most common reasons for non-spatial parcels are:

1. Flats and unit survey plans will create non-spatial parcels for referencing property rights. This is because the Landonline system has not yet been designed to support the spatial definition of these plans.

2. Titles which were not linked to a spatial parcel during the Landonline title conversion project created non-spatial parcel references. As titles are spatially linked many of these non-spatial parcels will be made historic or will be merged with the associated spatial parcel.

Parcels within this layer contain the following status flags:

• Approved: The definition of a survey-defined parcel that has been processed and authorised as correct in terms of the survey network.

• Current: A parcels that has been registered or the parcel is made current by a statutory action against a Legalisation plan.

• Survey Historic: A parcel that has been extinguished from the primary cadastral network but still exists in live Title estates.

• Historic: A parcel that has been extinguished from the primary cadastral network and no longer exists in live Title estates or has an current recorded statutory action. Typically this happens when a parcel is subdivided or merged, and new titles or actions are registered against the replacing parcels. Note: Only parcel made historic since the beginning of Landonline operations (2002) are included. See this page for the actual dates when Landonline operations started.

The Linear parcels within this layer has a nominal accuracy of 0.1-1m in urban areas and 1-100m in rural areas. For more detailed information about parcel accuracies please refer to the Survey Boundary Marks layer which contains accuracies for each parcel node.

The originating data for parcel/title associations includes some non-official sources where the official data does not support a link. For more information see.

This layer provides cadastral Survey Capture Areas (SCA).

In conjunction with the implementation of Landonline in each region, LINZ undertook a project to "back-capture" existing parcel boundaries in the main centres of population and land development. It was intended to "back-capture" approximately 70 percent of existing parcels, which equates to about 20 percent of the land area of New Zealand.

The data capture known as "Populate Electronic Parcel" (PEP) was undertaken under contract by EDS.

The areas to be captured known as "Survey Capture Areas" (SCA) were defined in consultation with local LINZ staff, survey practitioners and Local Authorities.

Within the defined SCAs, the dimensions for surveyed right-lined boundaries of current parcels were captured from existing survey plans. In addition, sufficient traverses, boundary ties, and connections to the geodetic control were captured or surveyed to ensure adequate network geometry and strengthen areas wLINZ Website the boundary dimensions are unreliable. This survey network was adjusted to generate modern survey coordinates for all relevant nodes. WLINZ Website the resulting boundaries comply with the accuracy requirements of the 1998 Survey Regulations, then the adjusted co-ordinates were declared to have SDC (Survey-accurate Digital Cadastre) status.

For more information see LINZ Website

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.

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.

This layer provides the latest bearing (direction) and/or distance for cadastral boundaries.

When a cadastral survey is undertaken the relationship between boundary and non-boundary marks is ascertained or measured.
• This commonly is in the form or a vector (bearing and distance), but occasionally just one component.
• Some relationships are defined as arcs. In this data layer, the arc length is recorded in the distance field and a separate record holds the chord.

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.