A zipped download package of an Esri File Geodatabase (River Environment Classification, REC 2 v 5, June 2019). This is a large download (>450 MB).REC2 (River Environment Classification, v2.5) - June 2019 The River Environment Classification (REC) is a database of
catchment spatial attributes, summarised for every segment in New
Zealand's network of rivers. The attributes were compiled for the
purposes of river classification, while the river network description
has been used to underpin models. Typically, models (e.g. CLUES and
TopNet) would use the dendritic (branched) linkages of REC river
segments to perform their calculations. Since its release and use over
the last decade, some errors in the location and connectivity of these
linkages have been identified. The current revision corrects those
errors, and updates a number of spatial attributes with the latest data.
REC2 provides a recut framework of rivers for modelling and
classification. It is built on a newer version of the 30m digital
elevation model, in which the original 20m contours were supplemented
with, for example, more spot elevation data and a better coastline
contour. Boundary errors were minimised by processing contiguous areas
(such as the whole of the North Island) together, which wasn't possible a
decade ago. Major updates include the revision of catchment land use
information, by overlaying with the latest land cover database (LCDB3,
current as at 2008), and the update of river and rainfall statistics
with data from 1960-2006. The river network and associated attributes
have been assembled within an ArcGIS geodatabase as a Geometric Network. Topological
connectivity has been established to allow upstream and downstream
tracing within the network. NIWA
acknowledges funding from the Terrestrial and Freshwater Biodiversity
Information System (TFBIS) towards the preparation of REC v2.5NIWA acknowledges funding from the MBIE SSIF towards the preparation of REC v2.5Coordinate Reference System: NZTM (New Zealand Transverse Mercator, EPSG: 2193)Geometric Representation of Rivers: LinesExtent (Bounding Box):
Top (Latitude)
-33.9534 Bottom (Latitude)
-47.4867 Left (Longitude)
166.2634
Right (Longitude)
178.9733
Riverlines table
Attributes
associated directly with network:
Field
Type
Description
Catarea
Real
Watershed area in m2 CUM_Area
Real
Area upstream of a reach (and
including this reach area) in m2. Nzsegment
Integer
Reach identifier to be used with
REC2 (supercedes nzreach in REC1).
Lengthdown
Real
The distance to coast from any
reach to its outlet reach, where the river drains (m). Headwater
Integer
Number (0) denoting whether a
stream is a “source” (headwater) stream. Non-zero for non-headwater streams.
Hydseq
Integer
A unique number denoting the
hydrological processing order of a river segment relative to others in the
network.
StreamOrder
Integer
A number describing the Strahler
order a reach in a network of reaches.
euclid_dist
Real
The straight line distance of a
reach from the reach “inlet” to its “outlet”. upElev
Real
Height (asl) of the upstream end
of a reach section in a watershed (m). downElev
Real
Height (asl) of the downstream
end of a reach section in a watershed (m).
upcoordX
Real
Easting of the upstream end of a
river segment in m (NZTM2000). upcoordY
Real
Northing of the upstream end of
a river segment in m (NZTM2000). downcoordX
Real
Easting of the downstream end of
a river segment in m (NZTM2000).
downcoordY
Real
Northing of the downstream end
of a river segment in m (NZTM2000). sinuosity
Real
Actual distance divided by the
straight line distance giving the degree of curvature of the stream nzreach_re
Integer
The REC1 identifiying number for
the corresponding\closest reach from
REC1 (can be used to retrieve the REC management classes) headw_dist
Integer
Distance of the furthermost
“source” or headwater reach from any reach (m). Shape_leng
Real
The length of the reach (vector)
as calculated by ArcGIS.
Segslpmean
Real
Mean segment slope along length
of reach.
LID
Integer
Lake Identifier number(LID) of
overlapping lake.
Reachtype
Integer
A value of 2 is assigned if the
segment is an outlet to the lake, otherwise 0 or null. nextdownid
integer
segment number of the most
downstream reach
