Survey Data - Page 2

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.

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.