Data - Page 6

The dataset contains polygons of soils of Opotiki District mapped at 1:15000. The attributes contain the soil series and the soil classification. No analytical properties of the soil are included.

The New Zealand Land Resource Inventory (NZLRI) is a national database of physical land resource information. It comprises two sets of data compiled using stereo aerial photography, published and unpublished reference material, and extensive field work:

1. An inventory of five physical factors (rock type, soil, slope, present type and severity of erosion, and vegetation). A 'homogeneous unit area' approach is used to record the five physical factors simultaneously to a level of detail appropriate for presentation at a scale of 1:50,000.

2. A Land Use Capability (LUC) rating of the ability of each polygon to sustain agricultural production, based on an assessment of the inventory factors above, climate, the effects of past land use, and the potential for erosion. The NZLRI covers the country in 11 regions, each with a separate LUC classification.

The first edition NZLRI provides national coverage from mapping between 1973 and 1979 at a scale of 1:63,360. A limited revision regional upgrade of the north Waikato area was completed at a scale of 1:63,360 in 1983. Second edition NZLRI regional upgrades at a scale of 1:50,000 have been completed for Northland, Wellington, Marlborough and Gisborne-East Cape. Third edition NZLRI layers contained a restructured polygon attribute table to allow the core NZLRI to complement the newly created fundamental soil layers with minimal duplication

The New Zealand Fundamental Soil Layer originates from a relational join of features from two databases: the New Zealand Land Resource Inventory (NZLRI), and the National Soils Database (NSD). The NZLRI is a national polygon database of physical land resource information, including a soil unit. Soil is one in an inventory of five physical factors (including rock, slope, erosion, and vegetation) delineated by physiographic polygons at approximately 1:50,000 scale. The NSD is a point database of soil physical, chemical, and mineralological characteristics for over 1500 soil profiles nationally. A relational join between the NZLRI dominant soil and derivative tables from the NSD was the means by which 14 important soil attributes were attached to the NZLRI polygons. Some if these attributes originate from exact matches with NSD records, while others derive from matches to similar soils or professional estimates. This layer contains the best available data (as at 2000) of Profile Readily Available Water (PRAW) which estimates water readily available to plants for the soil profile to a depth of 0.9 m, or to the potential rooting depth (whichever is the lesser). Values are weighted averages over the specified profile section (0-0.9 m) and are expressed in units of mm of water.

Map of indigenous forest classes in New Zealand (podocarp, broadleaved, beech, podocarp-broadleaved, beech-broadleaved, podocarp-broadleaved-beech, kauri, coastal, subalpine scrub).

Map of indigenous forest classes in New Zealand (podocarp, broadleaved, beech, podocarp-broadleaved, beech-broadleaved, podocarp-broadleaved-beech, kauri, coastal, subalpine scrub).

This layer was derived from three existing data layers: the Land Cover Database 2 (LCDB2) (MfE 2002); the Land Use Map (LUM) from the Land Use Carbon Analysis System (MfE 2008; Dymond et al. 2012); and EcoSat Forests (Shepherd et al. 2002). Indigenous forest classes from EcoSat Forests were combined with classes from LCDB2 to form basic ecosystems classes. Where indigenous forest was mapped by LCDB2, the type of forest was determined from the EcoSat Forests layer. The eight forest types of EcoSat Forests were reduced to three basic types: beech forest; podocarp-broadleaved forest; and mixed beech and podocarp-broadleaved forest. To produce a recent 2008 layer the LUM was used to update indigenous and exotic forest changes since 2002. The mapping was performed using 15 m pixels, which is equivalent to a mapping scale of approximately 1:50 000.

The New Zealand Fundamental Soil Layer originates from a relational join of features from two databases: the New Zealand Land Resource Inventory (NZLRI), and the National Soils Database (NSD). The NZLRI is a national polygon database of physical land resource information, including a soil unit. Soil is one in an inventory of five physical factors (including rock, slope, erosion, and vegetation) delineated by physiographic polygons at approximately 1:50,000 scale. The NSD is a point database of soil physical, chemical, and mineralological characteristics for over 1500 soil profiles nationally. A relational join between the NZLRI dominant soil and derivative tables from the NSD was the means by which 14 important soil attributes were attached to the NZLRI polygons. Some if these attributes originate from exact matches with NSD records, while others derive from matches to similar soils or professional estimates. This layer contains best available data as at 2000 for Cation Exchange Capacity (CEC) which is estimated as weighted averages for the soil profile from 0-0.6 m depth and expressed in units of centimoles of charge per kg (cmoles (+)/kg).

The New Zealand Fundamental Soil Layer originates from a relational join of features from two databases: the New Zealand Land Resource Inventory (NZLRI), and the National Soils Database (NSD). The NZLRI is a national polygon database of physical land resource information, including a soil unit. Soil is one in an inventory of five physical factors (including rock, slope, erosion, and vegetation) delineated by physiographic polygons at approximately 1:50,000 scale. The NSD is a point database of soil physical, chemical, and mineralogical characteristics for over 1500 soil profiles nationally. A relational join between the NZLRI dominant soil and derivative tables from the NSD was the means by which 14 important soil attributes were attached to the NZLRI polygons. Some if these attributes originate from exact matches with NSD records, while others derive from matches to similar soils or professional estimates. This layer contains depth to slowly permeable horizon attributes. Depth to a slowly permeable horizon describes the minimum and maximum depths (in metres) to a horizon in which the permeability is less than 4mm/hr as measured by techniques outlined in Griffiths (1985). If no slowly permeable horizon is observed, the taxon is allocated to Class 6 and a null value with numeric code -.99 is entered into the data fields. These classes, described more fully in Webb and Wilson (1995).

Particle size data layer used in the creation of Land Environments of New Zealand (LENZ) classification. The classification layers have been made publicly available by the Ministry for the Environment (see data.mfe.govt.nz/layers/?q=LENZ for to access these layers).

The data defines the average particle size based on the soil information (from the NZLRI) and the mapped parent material. This particle size data layer is differentiated into five classes, silt and clay (Class 1), Sand (2), Gravel (3), Coarse to very coarse gravel (4), Boulders to massive (5). The class defined as "0" signifies areas where there are no soil attributes recorded (i.e. high peaks of the Southern Alps).

Additional details such as discussion about the accuracy and reliability of the LENZ soil layers and the technical definitions of the categories in this layer are defined in the attached LENZ Technical Guide.

The New Zealand Fundamental Soil Layer originates from a relational join of features from two databases: the New Zealand Land Resource Inventory (NZLRI), and the National Soils Database (NSD). The NZLRI is a national polygon database of physical land resource information, including a soil unit. Soil is one in an inventory of five physical factors (including rock, slope, erosion, and vegetation) delineated by physiographic polygons at approximately 1:50,000 scale. The NSD is a point database of soil physical, chemical, and mineralogical characteristics for over 1500 soil profiles nationally. A relational join between the NZLRI dominant soil and derivative tables from the NSD was the means by which 14 important soil attributes were attached to the NZLRI polygons. Some of these attributes originate from exact matches with NSD records, while others derive from matches to similar soils or professional estimates. This layer contains rock outcrop and surface boulder attributes which are presented as the percentage of the area of the map units covered by rock outcrops or surface boulders. The classes originate from and are described more fully in Webb and Wilson (1995).