1.Every effort has been made to adopt terms in the March 97 draft of the Australian / New Zealand Topographic Data Dictionary. Where this has occurred the description includes reference to the standard in the form (DR 97068 or DR). These classes are also shown on the diagram in Italics.

2.The whole geographic area will be represented by one of three classes as follows:

LAND

ESTUARY

SEA

All other classes overlap with one or more of these.

3.The classes MHWM and MLWM have been dropped in favour of the more generic TIDAL ZONE LINE. This class has the attribute Tidal Zone Line Type which can take either of these values. This class has also been added to enable feature metadata to be recorded at the line level.

4.The class WATER LINE has been added to enable feature metadata to be added at the line level for all boundaries of inland water features.

5.The TIDAL ZONE overlaps with SEA and ESTUARY. LAND is from mhwm inland and includes offshore islands. 

6.Where a CLOSURE separates an ESTUARY from a SEA, it also separates two TIDAL ZONEs on both sides of the ESTUARY. This is because such a closure will be from mhwm on one side of the ESTUARY to mhwm of the other side. In cases where the ESTUARY does not generally flow to the SEA at mlwm, the CLOSURE will occur at the mlwm on the ESTUARY side.

7.All WATER BODY, WATERCOURSE, DAM, SPRING, WATERFALL and RAPID classes occur on LAND. Where an island of land has been formed within these features it will be identified as a separate polygon. In such cases a polygon will also occur in the corresponding feature however its attribute 'valid' will be set to '0'.

8.A river can optionally flow through an ESTUARY depending on the river name being assigned as an attribute to both the CONNECTOR and the ESTUARY. If the body of water between the WATERCOURSE and the SEA is not named as for the WATERCOURSE, then the named WATERCOURSE will terminate at the CLOSURE with the ESTUARY. In this case the ESTUARY and its connector will be named according to the ESTUARY feature. (Note: this may be a lagoon.)

9.A FLAT, WETLAND and FLOOD PLAIN must occur on LAND.

10.Terms used by LIS Photogrammetry relate as follows:

11.Terms used by LIS Topographic Section relate as follows:

12.The flow direction of linear features including 1D WATERCOURSE and CONNECTOR will need to be stored implicitly through the ordering of the points making up a line.

13.A proposed water body boundary is handled through the Water_Body_type attribute with the option (proposed).

14.A BEACH and its associated sand area above MHWM will be named through the entity NAMED GEOGRAPHIC FEATURE in the Nomenclature data model

15.Each CLOSURE will be given the attributes of the feature types that it separates. This enables total lengths to be calculated to a particular feature type such as a water body or estuary.

16.A reef which occurs outside the tidal zone is covered by the class SUBMERGED REEF.

17.Where a Class is a child of another Class it inherits all the attributes of the Parent in addition to its own attributes.

1. The March 97 draft of the Australian/New Zealand Topographic Data Dictionary has now been developed into ICSM Topographic Data Dictionary (last updated 19 November 1998).
2. When a class can be represented by more than one kind of spatial object, a child class is created for each of those spatial objects.
3. A class ARTIFICIAL WATERCOURSE has been created to enable a feature such as a pipeline to cross over streams without requiring intersections to be formed. This class is a child of WATERCOURSE.
4. The classes CLOSURE and CONNECTOR have been renamed as HYDROGRAPHIC CLOSURE and HYDROGRAPHIC CONNECTOR because their relationships, identifiers and some attributes are not generic but are specific to the Hydrographic theme.
5. The definition of ESTUARY has been expanded to satisfy the demands of all interested parties.
6. The class OFFSHORE ROCK has been renamed as ROCK, an entity listed in ICSM 1998 that may occur anywhere. Thus the problems caused by restricting the whereabouts of OFFSHORE ROCK no longer arise.
7. The class TIDAL ZONE LINE has been renamed as TIDAL LINE because it may represent two distinct types of feature i.e. a boundary of a TIDAL ZONE or a channel below MLWM that appears to be within a TIDAL ZONE.
8. Old/former watercourses will no longer be depicted.
9. The class WATER PIPELINE has been deleted. The feature is now a type of ARTIFICIAL WATERCOURSE.
10. The class WATER TANK has been deleted. The feature is now a type of WATER BODY.
11. Numerous changes have been made to the various relationships, attributes and code lists. Most of these changes are not documented here but can be seen in the actual model.

1. Addition of the attribute 'water body type' to the WATER BODY class.
2. Inclusion of 0D dams.
3. Inclusion of the attribute 'valid area' in ARTIFICIAL WATERCOURSE 2D.
4. Changes to some code lists.