Road Atlas of BC

Basemap

BaseMAP set

The Basemap data set currently consists of a series of data layers designed to give intelligent context to the Road Atlas. Intelligent is a key element. The Road Atlas BaseMap is a layered, GIS ready product with virtually every feature knowing what it is, and who it is.

Sources

There are two primary sources, the 1:20,ooo TRIM program from the BC Ministry of Sustainable Resource Management (MSRM), and the 1:50,ooo BC Watershed Atlas. Both of these were provided to GIS Innovations for the purpose of creating this BaseMap. Other key information sources include the BC Gazette (from MSRM), and the Canadian Hydrographic Charts, the official navigation charts, published by the Canadian Hydrographic Service. The Road Atlas BaseMap is the result of bringing the above data, along with various other local data sources. Finally, the BaseMap was further augmented by other web searches, fieldwork and telephone contact with various local authorities.

Display

The best display sequence is:

BaseLayer	Description	GIS DataType
Coastal_water	the marine waterway features	Polygon
Islands	all fresh and marine islands	Polygon
Fresh_water	lakes and double line rivers	Polygon
Rivers	a single line representation of rivers.	Line
Shoreline	a line for accenting the shore of marine islands, lakes & double line rivers	Line

Structure of the BaseMap

The Basemap is structured to allow for optimum usage and configuration within modern GIS systems. There are several distinguishing features built right in for GIS.

1. Virtually all features have a name. Features (rivers, lakes, islands) that have a gazetteer name in reality, have that name within our Basemap. Additionally, many features without gazetteer names, but with local names have that name applied.

2. The Rivers layer contains ranking codes. Ranking enables a sophisticated user to elect to show all rivers delivered, or to tier the display based upon rank.

3. The marine coast of British Columbia has been partitioned into approximately 2,300 smaller bodies of water, each with a name. This allows for 2 significant advantages. One, that nearly every gazetteer water body on the coast has a name. Two, by partitioning the coast into smaller polygons, we are able to maintain good positioning detail, while keeping the polygons small such that they do not exceed the maximum number of vertices allowable for a closed polygon. A second benefit is that the partitioning of the complex coast results in improved display performance.

4. The shoreline file allows for user defined accenting of the land-water interface. In addition to being a very strong display customization feature, this feature is needed to keep the construction lines off for the closed water polygons, especially the marine and double line river features.

Figure: sample of coastal partitioning

Attribute Table Structure

The Shoreline layer has not attributes table.
Coastal_water, Islands and Fresh_water Table

Field name	Description	Example	Data type
NAME	The name of the feature	Anvil Island	Number(23,0)
AREA	The area in sq_m	9,273,889	Character (60)

Rivers Table

Field name	Description	Example	Data type
NAME	The name of the feature	Fraser River	Character (30)
RANK	A code number from 1-9 indicating ranking; where 1 is key rivers.	1	Number(6,0)

Mapinfo BaseMap Display Settings

Field name	Coastal_ water	Islands	Fresh_ water	Rivers	shoreline
Mapinfo_brush_pattern	2	2	2
Mapinfo_brush_foreground	13693183	16774352	13693183
Mapinfo_pen_width	1	1	1	1	1
Mapinfo_pen_pattern	1	1	1	2	2
Mapinfo_pen_color	0	0	0	19424	19424