Potential evaporation is average annual Penman Potential Evapotranspiration for 1960-2006. It is interpolated from the potential evaporation data calculated at climate stations.

This layer is based on the New Zealand River Environment Classification REC2 V5 and describes the larger catchments of New Zealand that are a Strahler order five and greater. It also has the associated names that belong to the parent sea draining catchment. It was originally derived by dissolving local Strahler Order 1 watersheds. REC2 (River Environment Classification, v2.5) - June 2019 [Hosted Feature Layer]This service depicts catchments as polygons 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 re-cut 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 It is built on a newer version of the 30m digital elevation model, in which the original 20m contours were supplemented with, for example, more spot elevation data and a better coastline contour.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 when it was originally created.Major updates include the revision of catchment land use information, by overlaying with the 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. Topological connectivity has been established to allow upstream and downstream tracing within the network. This is based on REC2 (Version 5) , June 2019 - a publicly available dataset from NIWA Taihoro Nukurangi.NIWA 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: Lines Geometric Representation of Catchments: Polygons Extent (Bounding Box): Top(Latitude) -33.9534Bottom(Latitude) -47.4867 Left (Longitude) 166.2634 Right (Longitude) 178.9733 Available Fields: Shape,FID_1,diss,FID_2,HydroID,CATAREA,CUM_AREA,nzsegment,StreamOrde,upElev,downElev,upcoordX_1,downcoor_1,downcoor_2,upcoordY_1,RivName,Distance,ord_diff,Distance_1,Shape_Length,Shape_Area

NZ, New Zealand, Estuary, type

Originally drawn by the Department of Lands and Survey N.Z. and published by the N.Z. Met Service.

NZ seamounts 2009a (Malcolm Clark)

Conservation Units, Dept. of Conservation. Unknown date of supply and contact.

NIWA has published a lake chart for every lake in New Zealand that can be surveyed, except for Lake Dunstan. The charts are of various scales that are determined to be the most appropriate for the size of the lake. The compilation of bathymetry from echo-sounding surveys with publication dates ranging from 1966 to 1989. This dataset also contains newly surveyed bathymetry using multibeam information. New data as and when available shall be added to this dataset. Some of the lakes may have more than one set of bathymetry files. The earlier one could be from the period 1966 to 1989 and the new information from recent surveys undertaken for comparison purposes.

Actual evaporation is an estimated average annual value for 1960-2006. The values are calculated using AE = PE .* ( 1 + P/PE - (1+ (P/PE)^w)^(1./w) )whereAE = average annual actual evaporationPE = average annual potential evaporation (item 2 above)P = average annual precipitation (item 1 above)W = 4.35 (empirical constant value)

This provides a vector coastline and islands layer which is based on the Topo50 products. It is a combination of the following layers: - [NZ Coastlines (Topo 1:50k)](http://data.linz.govt.nz/layer/258-nz-coastlines-topo-150k/) - [NZ Island Polygons (Topo 1:50k)](http://data.linz.govt.nz/layer/288-nz-island-polygons-topo-150k/) - [NZ Auckland Is Island Polygons (Topo, 1:50k)](http://data.linz.govt.nz/layer/959-nz-auckland-is-island-polygons-topo-150k/) - [NZ Campbell Is / Motu Ihupuku Island Polygons (Topo, 1:50k)](http://data.linz.govt.nz/layer/932-nz-campbell-is-motu-ihupuku-island-polygons-topo-150k/)- [NZ Antipodes Is Island Polygons (Topo, 1:25k)](http://data.linz.govt.nz/layer/978-nz-antipodes-is-island-polygons-topo-125k/) - [NZ Kermadec Is Island Polygons (Topo, 1:25k)](http://data.linz.govt.nz/layer/908-nz-kermadec-is-island-polygons-topo-125k/)- [NZ Bounty Is Island Polygons (Topo, 1:25k)](http://data.linz.govt.nz/layer/992-nz-bounty-is-island-polygons-topo-125k/) - [NZ Snares Is / Tini Heke Island Polygons (Topo, 1:25k)](http://data.linz.govt.nz/layer/893-nz-snares-is-tini-heke-island-polygons-topo-125k/) - [NZ Chatham Is island polygons (Topo, 1:50k)](http://data.linz.govt.nz/layer/86-nz-chatham-is-island-polygons-topo-150k/)Islands from the NZ Island Polygons layer that lie within the NZ Coastline and Chatham Islands areas (i.e. islands in lakes, rivers and estuaries) have been removed. The GIS workflow to create the layer is: 1. NZ Coastlines were converted from a polyline to a polygon using a polyline to polygon tool. 2. The resulting coastal polygon was then used as an input into an erase tool and run against the NZ Island Polygon layer to remove all islands lying within the NZ Mainland and Stewart Island. 3. This was then merged with the NZ Chatham Is island polygons (Topo, 1:50k) that have had the islands within the main island polygon removed, NZ Auckland Is Island Polygons (Topo, 1:50k), NZ Campbell Is / Motu Ihupuku Island, NZ Antipodes Is Island Polygons (Topo, 1:25k), NZ Kermadec Is Island Polygons (Topo, 1:25k), NZ Bounty Is Island Polygons (Topo, 1:25k) and NZ Snares Is / Tini Heke Island Polygons (Topo, 1:25k) layers using a merge tool. 4. Lake Onoke from the NZ Lake Polygons (Topo 1:50k) layer and Te Whanga Lagoon from the NZ Chatham Is lagoon polygons (Topo, 1:50k) layer were then erased from the resultant polygon layer to include these two water bodies in the coastline definition. Coastline data from the Australian islands (Lord Howe, Norfolk, and Macquarie Is.) sourced from Geoscience Australia.

NIWA has published a lake chart for every lake in New Zealand that can be surveyed, except for Lake Dunstan. The charts are of various scales that are determined to be the most appropriate for the size of the lake. The compilation of bathymetry from echo-sounding surveys with publication dates ranging from 1966 to 1989. This dataset also contains newly surveyed bathymetry using multibeam information. New data as and when available shall be added to this dataset. Some of the lakes may have more than one set of bathymetry files. The earlier one could be from the period 1966 to 1989 and the new information from recent surveys undertaken for comparison purposes.