AsureQuality Rivers Dataset
Currently, the 1:50,000 scale rivers / streams topographic vector layers available from Land Information New Zealand (LINZ) do not carry name attributes. Although the NZMS260 series published maps show river names, the scale range (over which scans of the published paper maps can be used as backdrops) limits their usefulness. We have created an enhanced version of the LINZ topographic vector river layers. The utility of the vector river layers is increased thanks to the naming of streams - this allows maps of various scales to be created for field personnel and geo-coded pest and disease reports to be produced.
Objectives for the rivers dataset
- Produce a single vector polyline shape file or line coverage based on a merging of river centrelines. River borders and lake boundaries (where the lake was < 1 Ha) are depicted as polygons and comprise part of the river network.
- Standardise rivers and streams across all original contributing mapsheets. Produce equivalence in starting points for streams and sizes of streams represented (eg. eliminate manmade water races from Canterbury plains).
- Name river polylines to at least the same level of coverage as on the NZMS260 published map series.
- Ensure all stream segments have the correct downhill flow direction.
- Ensure there was network connectivity to support hydrological modeling, such as catchment delineation.
- Order the streams, such that differential symbology could be applied, or certain orders turned off to support cartographic usage at different scales.
Specifications
The AsureQuality Rivers Dataset is supplied as separate North Island and South Island shape files in New Zealand Transverse Mercator (NZTM) projection (other formats and projections available on request). The data is available at two specification levels, basic and complex rivers.
Version 1.2 - Basic Rivers
River polylines
- Based on a combination of river centrelines + river bodies + lake boundaries (where the size of each lake is < 1 ha and part of the river network) as present in the LINZ topographic vector dataset at Dec 05
- Starting points of headwater streams
- Based on the starting points included in the MfE / NIWA River Environment Classification (REC) dataset
Density of rivers
- Based on presence in the REC. (eg. many water-races in Canterbury plains have been removed)
Stream ordering
- Headwater streams = order 1
- Major rivers (eg. Buller River) = order 3
- All other rivers and streams = order 2
Naming of rivers based on names associated with STRM (natural watercourse) features in the NZ Geographic Placenames Database as at Nov 05
- Density of names at least equivalent to river naming on NZMS260 series published maps
- Names propagated down all order 3 river segments
- Accuracy of naming >= 99.5% correct river segment labelled (checked against NZMS260 maps)
Pricing
- North Island data only NZ$4,500 + GST
- South Island data only NZ$4,500 + GST
- All New Zealand NZ$7,500 + GST
Version 2 - Complex Rivers
The AsureQuality Complex Rivers dataset consists of the following characteristics and attributes, in addition to those included in the Basic Rivers dataset:
- All streams flowing in right direction (ie. downhill)
- Full network topology allowing tracing of drainage and delineation of catchments
- Names propagated down all named order 2 and 3 river segments
Pricing
- North Island data only NZ$9,000 + GST
- South Island data only NZ$9,000 + GST
- All New Zealand NZ$15,000 + GST
Note - Data refreshes can be purchased when updates are available. Data refresh pricing is negotiable, based on the frequency of updates required.
