Description

A ridge, usually of rocks or coral, lying near the surface of the sea, which may be visible at low tide, but is usually covered with water

Topo50 description

Only those significant either by their size or location, and sufficiently visible (water quality and wind conditions at the time imagery is collected can influence the ability to capture these features with certainty and accuracy), are held in the data and shown on the printed maps. LINZ charts may be a better source for reef features, see http://www.linz.govt.nz/hydro/charts/index.aspx

Map image

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Representation specification

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Example

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Aerial view

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Class attributes

Attribute	Value
Object class	reef_poly
Entity class	REEF
Additional entity class	Not applicable
Object inheritance	simple_area
Entity source	Proposed change to US Entity
Map series	Topo50
LSLIFF object class	331

Object attributes

Attribute	LSLIFF code Shapefile field Data type	Attribute description	Attribute values*
name	1001 name string	The name of the reef, where known. Text data from July 2012 will be in UTF-8 format. If your system is not UTF-8 compliant, you will need to use the name_ascii attribute, which has had any macronated vowels removed. UTF-8 stands for Unicode Transformation Format-8. It is an octet (8-bit) lossless encoding of Unicode characters. UTF-8 encodes each Unicode character as a variable number of 1 to 4 octets, where the number of octets depends on the integer value assigned to the Unicode character. It is an efficient encoding of Unicode documents that use mostly US-ASCII characters because it represents each character in the range U+0000 through U+007F as a single octet. UTF-8 is the default encoding for XML.	"Aotea Reef" {empty}
name_macronated	1140 macronated boolean	Indicates whether the entry in the name_ascii field contains a macronated vowel. Where the value is "Y" go to http://www.linz.govt.nz/regulatory/place-names/find-place-name/find-m%C4%81ori-place-names-dual-names-and-alternative-names for a list of places or feature names within New Zealand that are gazetted and include macrons	Y N
reef_composition	1077 compositn string		coral {empty}
name_ascii	9000 name_ascii string	Text data from July 2012 will be in UTF-8 format. If your system is not UTF-8 compliant, you will need to use this attribute, which has had any macronated vowels removed.
UFID	1000 t50_fid integer	A unique identifier for use on Topo50 data in the LINZ Data Service. This is not a universal ID. The intention is to manage these ID’s as persistent, however this is not guaranteed and there will be instances where what appears to be a minor change to a feature may result in a new ID being assigned.	"3254886"

* See explanation of attribute values for more information about how attribute values are represented.

Change log

Feature version	Revised	Description
7	2012-08-28	Updated map image and aerial view; added representation specification and example feature photographs
6	2012-08-28	Added scale-specific definitions
5	2012-08-16	Name attribute in UTF-8 format; added name_ascii attribute
4	2010-03-01	Added name_macronated attribute
3	2008-04-10	Removed reference to seed and void objects
2	2001-11-23	Unspecified update
1	1999-03-01	intial status