For full data description please visit: Vicmap Hydro (land.vic.gov.au)
Vicmap Hydro represents the natural and man-made water resources for Victoria and consists of point, line and polygon vector features in a seamless, networked and topologically structured dataset series. It comprises a basic framework of linear features supplemented by related point and polygon features to value add data for the water networks across the State. Attribute tables classify and describe the real-world features using code lists that can be used for search, discovery and analysis.
The following hydrographic features are contained within Vicmap Hydro:• Watercourse (line)- watercourse, connector, channel, drain• Water Area (polygon)- lake, flat, wetland, pondage, watercourse area• Water Area Boundary (line)- shoreline, junction• Water Point (point)- rapids, spring, waterfall, waterbody point• Water Area Fuzzy (polygon) – bay, beach, bend, entrance, inlet, passage, reach, sea
In inland and coastal areas, point and line features are used to describe various waterline related structures:• Water Structure Line (line)- wharf, marina, offshore platform, breakwater, launching ramp, dam wall, spillway, lock• Water Structure Point (point)- lock, well• Water Structure Area (polygon)- dam batter, spillway
Polygon voids
Polygon features may contain an inner set of lines, holes or voids that cannot be assigned to any feature class within that layer. For example, a Lake in the Water Area layer may have in the middle of it an area of dry land. This would appear in the data as a polygon with no paracentroid.
Coincident features
There will be no coincident polygons, lines (whole or in part) or points of the same feature type in the data (also frequently known as double digitising). Differing features may be coincident, as may be the case where a dam wall also forms part of a dam polygon, (in these cases, the common data repeats for each feature type, and is appropriately tagged and supplied as part of each feature type)
Connector
Drainage patterns are made up of both linear (narrow streams) and polygon features (such as watercourse areas, lakes and swamps) and consequently do not constitute a rigorous linear network. To allow linear analysis of drainage networks an artificial feature called a "Connector" has been added to the data.
This Connector feature is used to connect linear watercourse features where they are separated by water areas such as lakes, swamps and watercourses depicted as area features. The points that make up this chain cannot be given any value for planimetric accuracy. The Connector will only be used if there is flow across a waterbody polygon feature. Thus, if there is only inflow to a lake and no outflow the Connector feature will not be used.
Tributary watercourses flowing into a polygon area will be linked to the areas with Connectors.
Connectors are also used for drainage conveyed by pipelines (Connector_structure). The diagram below demonstrates the relationship between underground pipelines and other drainage features for the situation where pipelines cross drainage features. In this situation the underground pipeline will form the connection with connector features in the watercourse layer and needs to be cloned in the watercourse layer as a connector. A node is to be created in the watercourse layer, on the connector, at the intersection of any drainage lines crossing pipeline connector.
Junction
The Junction is a linear feature which is an artificial line used to separate adjacent polygon areas across which flow can occur. For example, a Junction feature will separate the confluence of two watercourses where both are depicted as polygons. A Junction also separates watercourse polygons from the Sea. The Junction feature is arbitrarily placed and cannot be given any value for planimetric accuracy.
Junction devices carry the attributes of the area entity they enclose.
Junction features will not be placed:• separating 2 water bodies with identical attributes.• separating polygons of different feature class except separating watercourse polygons, canal polygons, lakes, reservoirs and the sea from one another.
Junction features will be placed:• separating double line watercourses from other water bodies such as lakes and reservoirs.• separating waterbody polygons of the same class but with different attributes.• closing the mouth of rivers (waterbodies).• filling the coastal gaps in the framework layer.
Cross border data is not subject to the same data structures or accuracy as the content within Victoria. This is due to the differences in the data models between the States.