Appendix: Creating a new Modgen database file

Overview

If you want to make a biography using different actors and/or states, you will need to create a new database using Modgen.  The creation of the database file occurs with the execution of a Modgen simulation model and, therefore, requires some knowledge of the Modgen simulation environment.  The name, location, and contents of this special file are controlled as follows:

  • the filename, its location within the directory structure, and the number of simulated lifetimes contained within the database file are defined through a Modgen scenario and its Scenario Settings dialog box.  Modgen manages model run outputs by using the scenario name followed by a bracketed identifier indicating the type of Modgen output and an extension indicating the type of file. For tracking outputs, the convention used is: scenario_name(trk).mdb.

  • the set of actor/states to be displayed by BioBrowser must first be listed in the model variable trackingfacility within the Modgen source code for the specific simulation model. This set including the tracking filter for each actor are required by the model at compile time and can not be dynamically set at run time.

Scenario settings

There are a variety of Modgen scenario settings which determine the nature of each specific simulation.  The scenario settings are discussed in complete detail in the Modgen User’s Guide.  However, there are three main settings which must be understood in order to create an appropriate database file for the Biographical Browser.

  • In the Scenario/Settings/General tab, select "MS Access tracking". This setting tells Modgen that, in addition to the other outputs specified, a tracking database file is requested as output for this model run.
  • For case based models, select the number of cases in the Scenario/Settings/General tab. As a general rule, it is important to specify a small number here since all of the simulated cases which meet the tracking filter will be included in the database file. The size of this file can become very large, very quickly depending on the number of cases and states included. In addition, variable tracking will slow the simulation down considerably.
  • For time based models, select the time-units in the Scenario/Settings/General tab.

The demonstration file accompanying this release, demo(trk).mdb, contains 20 cases (which for this model corresponds to 20 simulated lifetimes of a person actor whose dominant state is True). It was created from the Statistics Canada model, LifePaths.

Modgen model state tracking

The tracking facility provided by the Modgen language controls the type of actors to be included in the database file along with the list of states which are to be analyzed with BioBrowser.

The track command must be included in one of the .mpp files which contain the Modgen model code which define the simulation model.  If the analyst wishes to change the type of actors to be tracked, or change the complement of the states to be output, then the Model must be re-compiled.  This is discussed further in the Modgen Developer’s Guide.  This guide should also be consulted by readers who are unfamiliar with the concepts outlined in the syntax and examples which follow.

Syntax of the Track Command

                track actor_name [filter] { state_or_link , ... , state_or_link } ;

It is important to remember that only one track definition is allowed for each actor in the model.  In addition, the filter specifies if and when an actor’s states or links are to be output to the database file.

Example

In this example, the states which describe the person are only output to the database file when he/she is married or remarried (the dominant characteristic is discussed in the Modgen Developer’s Guide).  Therefore, if the person was married at age 25, divorced at age 40, and re-married at age 50, then the database file would only contain information on this person from the ages of 25 through 40; and 50 to the age at death.  There are nine states which describe the characteristics of the individuals stored in the database file.  The last two items of the track definition are not variables but links to other individuals associated with this person.  In this case, the database will contain information on the nine variables defined in the track command on the person’s spouse and children if they are present.

track Person
[ dominant || mar_status == MARRIED || mar_status == REMARRIED ]
{
      es_state,
      ed_level_ep,
      sex,
      dominant,
      employed,
      mar_status,
      marstat_legal,
      fte_earnings,
      children_at_home,
      lSpouse,
      mlChildren
};

Example

In this example the date of birth and sex states for a child actor are output to the database file once the child is established in a family (the tentative characteristic is discussed in the Modgen Developer’s Guide.

track Child [ !tentative ]
{
      date_of_birth,
      sex,
      mlParents
};

Contents of the database file

The MS Access file produced by a Modgen simulation contains a data table called History and the following dictionaries organized hierarchically:

ActorDic - actor dictionary.
ActorStateDic - tracked state dictionary.
ActorLinkDic – tracked linked actor dictionary.
TypeDic - state type dictionary containing a pointer to a specific dictionary below.

The dictionaries for each state type are as follows:

SimpleTypeDic - for simple state types e.g.integer, double, float.
LogicalDic - for logical states.
ClassificationDic and ClassificationValueDic - for classification states and their values.
RangeDic - for range type states.
TypeDic - for linked actors.

Any dictionary with textual identifiers will contain 1 record for each language implemented in the specific Modgen model, as indicated by LanguageDic.

In addition, a file version table called VersionInfo will indicate the version of the tracking file. The BioBrowser uses this version to maintain backward compatibility if the tracking database design is changed.

The History table contains one record for each tracked state at one point in time. A record is added to this table, each time a tracked state changes for each tracked actor. The History table fields used by BioBrowser are: an object identifier, time, a state identifier, and a value for the given state.  The ShowData window contains a subset of records from this table. Since the object identifier is common across all records in the ShowData window, its value is shown in the window caption.

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Confidentiality: Statistics Canada is prohibited by law from publishing any statistics which would divulge information obtained from this survey that relates to any identifiable business without the previous written consent of that business. The data reported on this questionnaire will be treated in confidence and used for statistical purpose only. The confidentiality provisions of the Statistics Act are not affected by either the Access to Information Act or any other legislation.

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July 31, 2009

Instructions:

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Standard Drainage Area Classification

diagram showing the Hierarchy of drainage areas

* Note: The Standard Drainage Area Classification (SDAC) 2003 contains only the 974 sub-sub-drainage areas that are within Canada.

Description for the diagram

The SDAC provides unique numeric codes for three types of drainage areas: major drainage areas, sub-drainage areas and sub-sub-drainage areas. The three geographic areas are hierarchically related; a 4 character code is used to show this relationship. In addition to the SDAC classes, an aggregation variant classification of the sub-sub-drainage areas by drainage regions and ocean drainage areas is included. The relationship between these geographic areas is presented in the diagram showing the Hierarchy of drainage areas.

Additional information on SDAC

The development of drainage areasFootnote 1

The Water Survey of Canada (WSC) developed, in 1922, a Water Resources Index Inventory as a convenient and logical system for recording and filing water resources data such as the location of waterpower sites, waterpower developments, storage reservoirs, stream measurement stations, and meteorological stations. The Water Survey of Canada delineations involved the division, sub-division and sub-sub-division of Canada into suitably sized areas based on drainage characteristics, for administrative purposes. Although the boundaries are based on drainage, the intent was to include all of Canada's land mass and waters within this drainage area hierarchy to facilitate the identification of hydrometeorological sites. Therefore, the WSC drainage areas do not necessarily define individual river basins, but can represent intervening areas along the coast or include islands.

By the 1980s, there were different digital versions of Canadian drainage areas:

  1. Environment Canada produced a digital file of the paper map (1:2M scale) depicting the WSC drainage area boundaries;
  2. Statistics Canada digitized the WSC boundaries separately and integrated them with a base derived from the Census files. This digital version of the WSC maps was used for the tabulation of environmental statistics by drainage area starting in the 1980s;
  3. In 1985, the National Atlas of Canada produced a separate digital version tied to its 1:7.5M base and integrated this to produce paper maps for the 5th Edition of the National Atlas of Canada. This digital file depicts the drainage basins for many of the larger rivers of Canada. The National Atlas basin hierarchy has five levels (ocean drainage area, major river basin, component basin, sub-component basin, and sub-sub-component basin) and the major criterion used to define a National Atlas basin was a mean annual discharge of at least 280 m3/s at the mouth or confluence of the river;
  4. Several agencies (e.g., the Prairie Farm Rehabilitation Administration), provinces, and other authorities have compiled local digital drainage area boundaries.

In addition, large hydroelectric projects (e.g., James Bay) have had a significant impact on the hydrologic base and such changes were not maintained in a uniform manner. As a result, there was not a consistent, integrated, and up-to-date set of drainage area boundaries at the national level and it became time-consuming to work with other projects based on different boundaries.

The development of drainage areas is described in the sections below. The relationship between those drainage areas is also presented in the diagram showing the Hierarchy of drainage areas.

Development work in the 2000s

In 2000, Natural Resources Canada (NRCan), Environment Canada (EC) and Statistics Canada formed a partnership with an objective of producing one single national drainage area coverage for the country at a scale of 1:1,000,000. Each agency involved had specific requirements for the result, and certain design goals to be met. Since there were one set of drainage areas defined by Environment Canada and another by NRCan, it was agreed that a major goal for the project would be to support both definitions.The project resulted in a single national scale framework supporting the two distinct classification schemes.

The National Scale Frameworks Hydrology - Drainage Areas, Canada, Version 5.0

The single national scale framework for drainage areas, largely based on the WSC drainage area boundaries at the sub-sub-drainage area level, contains three drainage area datasets. There are the WSC, the National Atlas and the Fundamental Drainage Area (FDA) datasets.

Even though there is a high degree of similarity between the WSC classification and the National Atlas classification - approximately 95% of the National Atlas boundaries are also WSC boundaries - meaning that, with few exceptions, the National Atlas basins can be derived from the WSC sub-sub-drainage areas, it is necessary to introduce a smaller unit in order to reconcile both classifications. That is the purpose of the FDA dataset, to allow data to be aggregated to either of the two classifications. In general, these fundamental units are the same as the WSC sub-sub-drainage areas, but some sub-sub-drainage areas have been split to accommodate the following situations:

  1. Water Survey and Atlas units do not match;
  2. Identifying areas of internal drainage; and
  3. Inconsistencies in the flow hierarchy.

As specified above, the WSC hierarchy was designed for administrative purposes. Each level of hierarchy has its own code and name with a systematic coverage for Canada.

In contrast, the National Atlas of Canada's hierarchy defines basins whose outflow exceeds a certain criterion. At its highest level, it does divide the complete country into five ocean drainage areas but at lower levels the basins do not cover the entire country. This makes it unsuitable for use as a geographic standard for statistical reporting.

Standard Drainage Area Classification (SDAC) 2003

Version 5.0 of the WSC dataset from the National Scale Frameworks Hydrology - Drainage Areas, Canada is used by Statistics Canada as the basis for the Standard Drainage Area Classification (SDAC) 2003. In the drainage area classification of this Frameworks dataset, Canada has eleven major drainage areas which are divided into 164 sub-drainage areas; the 164 sub-drainage areas are then further divided into 978 sub-sub-drainage areas. All drainage areas, sub-drainage areas and sub-sub-drainage areas are named and have an identifying code. This classification is used by Statistics Canada as the basis for the Standard Drainage Area Classification (SDAC) 2003. The Standard Drainage Area Classification (SDAC) 2003 also contains the major drainage areas, sub-drainage areas and sub-sub-drainage areas but with the following modifications:

  • Some drainage areas in the Frameworks dataset straddle the Canada-United States border; the Standard Drainage Area Classification (SDAC) 2003 includes only the parts within Canada since this is used for reporting Canadian data. The SDAC 2003 excludes 4 of the sub-sub-drainage areas that are entirely outside the boundary of Canada. Therefore, the Standard Drainage Area Classification (SDAC) 2003 contains only the 974 sub-sub-drainage areas that are within Canada.
  • The Great Lakes were not assigned a drainage area in the Frameworks dataset; Canadian islands in the Great Lakes are assigned a drainage area in the Standard Drainage Area Classification (SDAC) 2003 for the purposes of data reporting.

The Frameworks dataset as well as the SDAC classification cover all of Canada including islands and freshwater lakes; however, the classification does not cover marine water.

The concept of drainage area is used in Statistics Canada's environmental and agricultural statistics programs. Generally, the detailed level of the sub-drainage area is used for disseminating statistics. Exceptions include "A Geographical Profile of Manure Production in Canada, 2001", a research paper in which data are presented at the sub-sub-drainage area level for only those areas with livestock farming activities.

Classification variant: Drainage Regions - SDAC 2003

The variant Drainage Regions has three levels: 5 ocean drainage areas, 25 drainage regions and 974 sub-sub-drainage areas. The drainage regions in this classification variant are based on the major river basins depicted in "Currents of Change: Final Report of the Inquiry on Federal Water Policy", Environment Canada, a report prepared in 1985 by Peter H. Pearse, Françoise Bertrand, and James W. MacLaren. The drainage regions were developed to provide a good representation of the hydrology in Canada and can be built-up from the sub-sub-drainage areas of the Standard Drainage Area Classification (SDAC) 2003. The ocean drainage areas that form a classification level in the variant are based on the ocean drainage areas in National Scale Frameworks Hydrology - Drainage Areas, Canada, Version 5. The twenty-five drainage regions are named and numbered as are the five ocean drainage areas, and the sub-sub-drainage areas.

The environmental statistics program in Statistics Canada uses drainage regions in its annual report "Human Activity and the Environment: Annual Statistics" to tabulate population and water resource characteristics. The drainage regions are also used for area sampling in environmental surveys. These regions are considered to provide a good representation of the hydrology in CanadaFootnote 2.

Future development

NRCan has recently completed Version 6.0 of the National Scale Frameworks Hydrology - Drainage Areas, Canada. Statistics Canada has not participated significantly in the revision process, and has decided that there were not enough changes to justify adopting it. Statistics Canada will continue to use version 5.0 when disseminating data by drainage areas, until further notice.

In addition, NRCan is working on the National Hydro Network (NHN). The NHN is a hydrographic layer in GeoBaseFootnote 3, constructed using the best databases available in Canada, which improves the precision of drainage area boundaries and other hydrological components. The NHN works in cooperation with several provincial and territorial partners in the implementation of this project in their respective geographic areas. The NHN is being disseminated in progressive phases called completeness levels. The first national NHN coverage has been completed in 2008. At this point in time, Statistics Canada has begun collaborating with the NHN project.

Footnotes

Footnote 1

Brooks, Rupert, K. David Harvey, Doug W. Kirk, François Soulard, Andrew Murray, Peter Paul. 2002. "Building a Canadian Digital Drainage Area Framework." Proceedings of the 55th Annual Canadian Water Resources Association Conference. Winnipeg.

Return to footnote 1 referrer

Footnote 2

Peter H. Pearse, Françoise Bertrand, and James W. MacLaren. 1985. Currents of Change: Final Report of the Inquiry on Federal Water Policy. Environment Canada.

Return to footnote 2 referrer

Footnote 3

GeoBase is a federal, provincial and territorial government initiative that is overseen by the Canadian Council on Geomatics (CCOG). It is undertaken to ensure the provision of, and access to, a common, up-to-date and maintained base of quality geospatial data for all of Canada.

Return to footnote 3 referrer

Drainage Regions - Variant of SDAC 2003

Introduction

The variant Drainage Regions was developed to enable the production of integrated statistics by hydrographic areas. It provides a set of geographical units that are convenient for data collection and compilation, and useful for spatial analysis of environmental, economic and social statistics. Drainage regions are used for dissemination of data and for sampling in environmental surveys.

The variant Drainage Regions has three levels: 5 ocean drainage areas, 25 drainage regions and 974 sub-sub-drainage areas. The ocean drainage areas are drainage areas named for the five large water bodies into which Canadian waters drain: the Pacific, Arctic and Atlantic Oceans, Hudson Bay, and the Gulf of Mexico. The ocean drainage areas have been assigned a one digit numeric identifier code. All 25 drainage regions are named and have an identifying unique code. The 25 drainage regions provide a good level of disaggregating for data reporting. They are also used for area sampling in environmental surveys. These regions are considered to provide a good representation of the hydrology in CanadaFootnote 1.

This variant is defined in terms of the sub-sub-drainage areas in the Standard Drainage Area Classification (SDAC) 2003. A drainage area is composed of a drainage basin as well as adjacent areas, such as coasts and islands that may not drain into the outletFootnote 2. A drainage basin is an area in which all contributing surface waters share the same drainage outlet. This classification covers drainage areas and therefore applies to all of Canada including coasts and islands that may not drain into an outlet. The variant Drainage Regions covers all the land and interior freshwater lakes of the country. Some drainage areas straddle the Canada-United States border. This classification includes only the parts within Canada since it is used for reporting Canadian data.

The relationship between the classification levels in this variant and the Standard Drainage Area Classification (SDAC) 2003 is presented in the diagram showing the Standard Drainage Area Classification.

Conformity to relevant nationally recognized standards

In 2000, Natural Resources Canada, Environment Canada and Statistics Canada formed a partnership to produce a single national drainage area dataset at a scale of 1:1,000,000. As a result of the partnership The National Scale Frameworks Hydrology - Drainage Areas, Canada, Version 5 was completed in 2003. In the drainage area classification of this Frameworks dataset, Canada has eleven major drainage areas which are divided into 164 sub-drainage areas; the 164 sub-drainage areas are then further divided into 978 sub-sub-drainage areas. All drainage areas, sub-drainage areas and sub-sub-drainage areas are named and have an identifying code. This classification is used by Statistics Canada as the basis for the Standard Drainage Area Classification (SDAC) 2003. The Standard Drainage Area Classification (SDAC) 2003 also contains the major drainage areas, sub-drainage areas and sub-sub-drainage areas but with the following modifications:

  • Some drainage areas in the Frameworks dataset straddle the Canada-United States border; the Standard Drainage Area Classification (SDAC) 2003 includes only the parts within Canada since this is used for reporting Canadian data. The SDAC 2003 excludes 4 of the sub-sub-drainage areas that are entirely outside the boundary of Canada. Therefore, the Standard Drainage Area Classification (SDAC) 2003 contains only the 974 sub-sub-drainage areas that are within Canada.
  • The Great Lakes were not assigned a drainage area in the Frameworks dataset; Canadian islands in the Great Lakes are assigned a drainage area in the Standard Drainage Area Classification (SDAC) 2003 for the purposes of data reporting.

The variant Drainage Regions is defined in terms of the sub-sub-drainage areas in the Standard Drainage Area Classification (SDAC) 2003 and includes these modifications. The ocean drainage areas that form a level in the variant are based on the ocean drainage areas in National Scale Frameworks Hydrology - Drainage Areas, Canada, Version 5. The Frameworks dataset as well as the SDAC classification cover all of Canada including islands and freshwater lakes; however, the classification does not cover marine water. Further information on the development of drainage areas is presented in the Additional information on SDAC.

A digital representation of the national scale frameworks hydrology - drainage areas is available for free on Natural Resources Canada's Geogratis website.

Footnotes

Footnote 1

Peter H. Pearse, Françoise Bertrand, and James W. MacLaren. T. 1985. Currents of Change: Final Report of the Inquiry on Federal Water Policy. Environment Canada.

Return to footnote 1 referrer

Footnote 2

Natural Resources Canada, Canadian Centre for Remote Sensing (CCRS), GeoAccess Division, 2003, National Scale Frameworks HYDROLOGY, Version 5.0, A practical guide to the datasets (accessed October 17, 2008)

Return to footnote 2 referrer

Standard Drainage Area Classification (SDAC) 2003

Introduction

The Standard Drainage Area Classification (SDAC) 2003 was developed to enable the production of integrated statistics by hydrographic areas. It provides a range of geographical units that are convenient for data collection and compilation, and useful for spatial analysis of environmental, economic and social statistics. A drainage area is composed of a drainage basin as well as adjacent areas, such as coasts and islands that may not drain into the outletFootnote 1. A drainage basin is an area in which all contributing surface waters share the same drainage outlet. This classification covers drainage areas and therefore applies to all of Canada including coasts and islands that may not drain into an outlet.

The Standard Drainage Area Classification (SDAC) 2003 covers all the land and interior freshwater lakes of the country. Some drainage areas straddle the Canada-United States border. This classification includes only the parts within Canada since it is used for reporting Canadian data.

There are three levels in the 2003 version of the classification - 11 major drainage areas, 164 sub-drainage areas and 974 sub-sub-drainage areas. All drainage areas, sub-drainage areas and sub-sub-drainage areas are named and have an identifying unique code. The code used is a four-character alphanumeric code. Two leading numeric digits represent the major drainage areas, the third alphabetic character represents the sub-drainage areas and a fourth alphabetic character represents the sub-sub-drainage areas.

Structure of the Standard Drainage Area Classification (SDAC) 2003
Level Characters in Code (cumulative)
major drainage area 2
sub-drainage area 3
sub-sub-drainage area 4

Among the levels in this classification, the detailed sub-drainage area level is generally used for disseminating statistics.

Description of major drainage areas

Canada is divided into eleven major drainage areas:

The table displays the name (first column) and are information (second (square kilometres) and third (%) columns).

Major drainage areas
Major drainage area name Area
square kilometres %
Maritime Provinces 163,990 1.6
St. Lawrence 1,067,879 10.7
Northern Quebec and Labrador 1,158,292 11.6
Southwestern Hudson Bay 735,320 7.4
Nelson River 987,015 9.9
Western and Northern Hudson Bay 1,253,213 12.6
Great Slave Lake 974,853 9.8
Pacific 666,349 6.7
Yukon River 337,036 3.4
Arctic 2,605,138 26.1
Mississippi River 27,097 0.3
Canada 9,976,182 100.0

Note: The classification covers all of Canada including islands and freshwater lakes; however, the classification does not cover marine water. The numbers in the table show the area covered in the classification.

The Maritime Provinces drainage area covers New Brunswick, Prince Edward Island, Nova Scotia and part of the Gaspé Peninsula in eastern Quebec. This area drains into the Gulf of St. Lawrence and the Atlantic Ocean. Halifax, Fredericton and Charlottetown are located in this drainage area.

The St. Lawrence drainage area includes all of southern Quebec, southern Ontario and Newfoundland. Cities in this drainage area include Montréal, Toronto, Ottawa, Thunder Bay, St. John's and Corner Brook.

The Northern Quebec and Labrador drainage area covers all the area just north of the St. Lawrence drainage area. Most of the water in this drainage area drains into Hudson, James and Ungava bays. The Labrador portion of the drainage area drains directly into the Atlantic Ocean. Communities in this drainage area include Chibougamau and Kuujjuaq in Quebec and Happy Valley-Goose Bay in Labrador.

The Southwestern Hudson Bay drainage area covers a large portion of northern Ontario, a small part of western Quebec and northeastern Manitoba. Communities in this drainage area include Val-d'Or in Quebec and Kapuskasing and Timmins in Ontario.

The Nelson River drainage area covers most of the southern Prairie provinces, from the Rockies to northwestern Ontario. Major cities within this drainage area are Winnipeg, Regina, Saskatoon, Calgary and Edmonton. Water from the Nelson River drainage area ultimately drains into Hudson Bay.

The Western and Northern Hudson Bay drainage area includes parts of eastern Alberta, all of the middle portions of Saskatchewan, northwestern Manitoba, the northeastern portion of the Northwest Territories, southeastern Nunavut, the Hudson Bay islands and part of Baffin Island. The following communities are found in this drainage area: Bonnyville, Alberta; La Ronge, Saskatchewan; and Rankin Inlet, Nunavut.

The Great Slave Lake drainage area is composed of northern Alberta, northern Saskatchewan, southern Northwest Territories and a small portion of British Columbia. Cities within this drainage area include Grande Prairie and High Level in Alberta, Yellowknife and Hay River in the Northwest Territories, and Fort St. John in British Columbia.

The Pacific drainage area includes all the area that is west of the continental divide, representing about 70% of the province of British Columbia. The southwestern part of the Yukon is also part of this drainage area. Some of the communities in the eastern portion of the drainage area are Kimberley, Golden and Invermere, all in British Columbia. Cities in the western portion include Vancouver, Victoria, Abbotsford and Whistler. Terrace and Prince Rupert in British Columbia are among the northern communities in this drainage area.

The Yukon River drainage area contains most of the western portion of the Yukon territory. The most southerly portion of this drainage area is in British Columbia. Communities and cities in this drainage area are Whitehorse, Dawson and Old Crow in the Yukon. The Yukon River flows through central Alaska, and ultimately into the Bering Sea.

The Arctic drainage area covers most of the arctic islands and large portions of the Northwest Territories, Nunavut, Yukon and, to a lesser extent, British Columbia and Alberta. Communities within this drainage area include Inuvik in the Northwest Territories, Fort Nelson in British Columbia, and Pangnirtung, Iqaluit and Resolute in Nunavut.

Finally, the Mississippi River drainage area covers a small area in the southernmost parts of Alberta and Saskatchewan.

Conformity to relevant nationally recognized standards

In 2000, Natural Resources Canada, Environment Canada and Statistics Canada formed a partnership to produce a single national drainage area dataset at a scale of 1:1,000,000. As a result of the partnership The National Scale Frameworks Hydrology - Drainage Areas, Canada, Version 5 was completed in 2003. In the drainage area classification of this Frameworks dataset, Canada has eleven major drainage areas which are divided into 164 sub-drainage areas; the 164 sub-drainage areas are then further divided into 978 sub-sub-drainage areas. All drainage areas, sub-drainage areas and sub-sub-drainage areas are named and have an identifying code. This classification is used by Statistics Canada as the basis for the Standard Drainage Area Classification (SDAC) 2003. The Standard Drainage Area Classification (SDAC) 2003 also contains the major drainage areas, sub-drainage areas and sub-sub-drainage areas but with the following modifications:

  • Some drainage areas in the Frameworks dataset straddle the Canada-United States border; the Standard Drainage Area Classification (SDAC) 2003 includes only the parts within Canada since this is used for reporting Canadian data. The SDAC 2003 excludes 4 of the sub-sub-drainage areas that are entirely outside the boundary of Canada. Therefore, the Standard Drainage Area Classification (SDAC) 2003 contains only the 974 sub-sub-drainage areas that are within Canada.
  • The Great Lakes were not assigned a drainage area in the Frameworks dataset; Canadian islands in the Great Lakes are assigned a drainage area in the Standard Drainage Area Classification (SDAC) 2003 for the purposes of data reporting.

The Frameworks dataset as well as the SDAC classification cover all of Canada including islands and freshwater lakes; however, the classification does not cover marine water. Further information on the development of drainage areas is presented in the Additional information on SDAC.

A digital representation of the national scale frameworks hydrology - drainage areas is available for free on Natural Resources Canada's Geogratis website.

Footnotes

Footnote 1

Natural Resources Canada, Canadian Centre for Remote Sensing (CCRS), GeoAccess Division, 2003, National Scale Frameworks HYDROLOGY, Version 5.0, A practical guide to the datasets (accessed October 17, 2008)

Return to footnote 1 referrer

Standard Drainage Area Classification (SDAC) 2003

Status

This standard was approved as a departmental standard on February 16, 2009.

The Standard Drainage Area Classification (SDAC) is Statistics Canada's official classification of drainage areas in Canada. The SDAC provides unique numeric codes for the levels in the hierarchy of drainage areas: major drainage areas, sub-drainage areas and sub-sub-drainage areas. The three geographic areas are hierarchically related; a 4 character code is used to show this relationship. In addition to the drainage area classes, a classification variant of the sub-sub-drainage areas by drainage regions and ocean drainage areas is included. The relationship between these geographic areas is illustrated in the diagram showing the Standard Drainage Area Classification and the hierarchical structure of the classification.

Major drainage areas are presented in the major drainage areas and sub-drainage areas map of Canada.

The Standard Drainage Area Classification (SDAC) 2003 is based on Version 5 of the National Scale Frameworks Hydrology - Drainage Areas, Canada. The National Scale Frameworks Hydrology was developed by a partnership consisting of Natural Resources Canada, Environment Canada and Statistics Canada.

Variant of SDAC 2003

The classification variant of SDAC is a set of customized groupings that use SDAC sub-sub-drainage areas as building blocks. In Statistics Canada, variants are created and adopted in cases where the version of the classification does not fully meet specific user needs for disseminating data or for sampling in surveys. A classification variant is based on a classification version such as SDAC 2003. In a variant, the categories of the classification version are split, aggregated or regrouped to provide additions or alternatives (e.g. context-specific additions) to the standard structure of the base version.

Ocean drainage areas and drainage regions are presented in the ocean drainage areas and drainage regions map of Canada.

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