Clip of Lake Winnipeg Watershed from Atlas of ...
The Drainage Areas dataset is largely based on the Water Survey of Canada (WSC) drainage area boundaries at the sub-sub-basin level. The data model supports the derivation, from the Fundamental Drainage Areas (FDA) dataset (sub-sub-basin level), of the WSC and the National Atlas of Canada (NA) (AC) drainage area hierarchies and the data is available in all three schemes. Drainage area definitions for both WSC and Atlas of Canada boundaries were reviewed resulting in some modifications. Larger scale reference data sources were used for further manual boundary adjustments. This dataset has been integrated with other National Scale Frameworks hydrology datasets and is considered a component of the Hydrology Theme. The Water Survey of Canada (Environment Canada) has a 3-level hierarchy of drainage areas established in 1927 for the purpose of managing hydrometric stations (recording water levels or rates of flow). This scheme covers the entire landmass of Canada. The National Atlas Drainage Basin scheme, delineated on a paper map in 1980, was based on classic drainage basins having certain minimum volume of mean annual discharge. (A classic drainage basin is a land area for which all the surface drainage with its boundary converges and exits at a single point.) The National Atlas Drainage Basin scheme effectively excludes coastal drainage areas whose discharge volume does not meet its criterion for inclusion. In 2006-2007 the Atlas of Canada added a fourth scheme to the drainage areas frameworks. Selected Fundamental Drainage Areas polygons were merged to create a full-country coverage of 595 'Canadian Watersheds' to be used in the broad public dissemination of information on watersheds and water issues. The National Scale Frameworks Hydrology data consists of area, linear and point geospatial and attribute data for Canada's hydrology at a national scale. It provides a representation of Canada's surface water features, and data completeness reflects the content of the source, the original Vector Map level 0 (VMAP0) revision 4 hydrographic layers, except where revision editing has been performed. Key value-added characteristics include river flow direction, connectivity and the tagging of geographical name keys to selected rivers, lakes and islands included in the Concise Gazetteer of Canada. The product set for the hydrology theme consists of six groupings: Drainage Network Skeleton, Waterbodies, Islands, Drainage Areas, Supplemental Drainage Features (Hydrometric Gauging Stations and Dams) and Cartographic.
|Last updated||November 12, 2014|
|Created||November 12, 2014|
|License||Creative Commons Attribution Share-Alike|
|created||over 3 years ago|
|on same domain||1|
|resource group id||96e00939-80ac-433d-b09f-8562b286c88b|