MPI SLMACC Northland - Erosion Inventory


Creative Commons Attribution 3.0 New Zealand

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13 Apr 2017

This dataset was first added to LRIS Portal on 13 Apr 2017.

This erosion type mapping was carried out on-screen using the 10 cm digital orthophotography supported by visual terrain analysis using the LiDAR DEM (hill shade and slope classification). The orthophotos were used to identify the most recent erosion features in the Kaikohe
study area; the DEM aided the mapping of features not visible in the orthophotos due to age
or vegetation cover.

The classification of erosion types followed the categories defined by the Land Use
Capability Survey Handbook (Lynn et al. 2009), which differentiates between surface
erosion, mass movement, fluvial erosion, and deposition. Note that the estimated depth of the
landslides (s = shallow, d = deep) was not consistently recorded; instead, the area of the
landslides serves as a reasonable proxy.

The project report (11 Mb PDF) relating to this work is downloadable at

Layer ID 48556
Data type Vector multipolygon
Feature count 1645
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W)

Sediment Retained


Creative Commons Attribution-Noncommercial-No Derivative Works 3.0

You may not use this work for commercial purposes.

You must attribute the creator in your own works.

You must not release derivatives of this work.

23 Apr 2018

This dataset was first added to LRIS Portal on 23 Apr 2018.

This layer depicts estimated sediment/soil retention across New Zealand and was created using the NZeem erosion model. Sediment retained is defined as the difference between soil loss with and without tree cover (sediment loss avoided). Erosion control is defined as the prevention of soil loss by an ecosystem. NZeem has been calibrated from sediment discharges measured in New Zealand rivers (Dymond et al., 2010). This model estimates the long-term mean erosion rate from all sources of erosion, both mass-movement and surficial, and accounts for all sizes of rainfall events. The model was run on the national datasets of rainfall, erosion terrains, and land cover to produce a national 1:50,000 scale map of long-term mean erosion rates. Dymond et al. (2010) assessed the accuracy of the model by comparing predictions of specific sediment discharge (assuming sediment delivery ratio of 1 everywhere) with available measurements and obtained a model efficiency of 0.64.

Layer ID 95387
Data type Grid
Resolution 100.000m
Services Raster Query API, Catalog Service (CS-W), Atom Feed
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