Number of extreme wave events exceeding 8m in coastal regions, 2008–15

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Creative Commons Attribution 3.0 New Zealand

You may use this work for commercial purposes.

You must attribute the creator in your own works.

148
4
Added
20 Oct 2016

This dataset was first added to MfE Data Service on 20 Oct 2016.

Extreme wave indexes estimate the occurrence of extreme wave events in coastal and oceanic waters. Extreme wave indexes estimate the number of times a significant wave height exceeds one of three threshold values for at least 12 hours in 24 marine regions. The three wave-height thresholds are four metres, six metres, and eight metres.
This indicator estimates the exceedances of a wave-height threshold for each year from 2008 to 2015 in coastal regions.
Significant wave height is a measure of the ‘typical’ wave height in a place over a time period. It is four times the standard deviation of the water surface if, for example, you were to measure water moving up and down a jetty piling for an hour. The largest individual wave will typically have a height around twice the significant wave height.
We use three wave-height thresholds because of the regional variation in extreme wave events. In general, the north experiences less exposure to consistently strong winds, and the waves generated by them, than the south. Four-metre tall waves are considered extreme in the northern-most parts of New Zealand but are more common in the south. For the southern-most parts of New Zealand, eight-metre waves better represent extreme wave events.
This dataset relates to the number of extreme wave events exceeding the eight metre threshold in coastal regions.

License

Creative Commons Attribution 3.0 New Zealand

You may use this work for commercial purposes.

You must attribute the creator in your own works.

Technical Details
Layer ID 3502
Data type Vector multipolygon
Feature count 144
Attributes Year, Significan, Duration_T, Annual_Exc, Area_Name, Date_start, Date_end, Shape_Length
Services Vector Query API, Web Feature Service (WFS), Catalog Service (CS-W), data.govt.nz Atom Feed
History
Added 20 Oct 2016
Last updated 20 Oct 2016
Revisions 6 - Browse all revisions
Current revision Imported on Oct. 26, 2016 from File Geodatabase in WGS 84. 144 geometries modified to be OGC compliant. Changelog.

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