- Title
- Manitoba Hydrometric Gauging Stations
- License
- Creative Commons Attribution 4.0 International (CC BY 4.0)
-
+ You are free to: Share — copy and redistribute the material in any medium or format. Adapt — remix, transform, and build upon the material for any purpose, even commercially. The licensor cannot revoke these freedoms as long as you follow the license terms.
+ For more info see https://creativecommons.org/licenses/by/4.0/. - Abstract
Manitoba Hydrometric Stations contains gauging stations as points. Each hydrometric gauging station point includes 27 pieces of information: its number, name, two location fields, type (stream, lake, shoreline, etc), nine levels of small- to medium-scale watershed identification, regional location, naming authority, six associated area values, a unique identifier to differentiate stations with the same name, a "selection" identifier, and a comment field to record new information or changes. Attributes have been appended for specific Manitoba data. In developing polygons of incremental areas of gross drainage, several stations may share the same polygon. For calculation purposes, only one station links the flow network downstream. That "selected" station is declared primary (SELECT = 1 or (SELECT = 0 and STN_TYPE = 101, 102 for MB)).
- Publication Date
- Aug. 4, 2022, 4:16 p.m.
- Type
- Vector Data
- Keywords
- Category
- Inland Waters
- Inland water features, drainage systems and their characteristics. Examples: rivers and glaciers, salt lakes, water utilization plans, dams, currents, floods, water quality, hydrographic charts.
- Regions
- Canada
- Responsible
- provmb
- Group
- Province of Manitoba
- Attribution
- Province of Manitoba, Manitoba Water Stewardship, Manitoba Land Initiative
- Maintenance Frequency
- Frequency Of Maintenance For The Data Is Not Known
- Restrictions
- formal permission to do something
- Edition
- Ver. 5.0
- Purpose
To contain all Manitoba Hydrometric station locations and pour point locations for watersheds within a single coverage.
- Language
- English
- Supplemental Information
Source: https://mli.gov.mb.ca/water_resources/gross_watershed_index.html
ABSTRACT
The Watershed Project is a long-term Prairie Farm Rehabilitation Administration (PFRA) undertaking that has entailed the creation and maintenance of a drainage area database (based on hydrometric gauging stations) for the Canadian Prairies. This database has evolved considerably since its inception in the early 1970s.
Currently, it consists of hydrometric gauging stations and watershed boundaries, tabulated gross and effective drainage areas, and digital products generated for use in hydrological mapping and analysis. The spatial extent of the database covers all of Alberta, Saskatchewan and Manitoba, and portions of adjacent jurisdictions (British Columbia, the Northwest Territories, Nunavut, Ontario, and the United States) into which Prairie watersheds extend.
The majority of gauging stations in this database are federal stations established by Water Survey of Canada (Environment Canada). This database also includes a relatively small number of provincial, American and "fictitious" gauging stations. The locations of these gauging stations were determined from Dominion Land Survey descriptions or from published latitude/longitude coordinates.
The GIS database is the authoritative source for the gross and effective drainage areas in the Prairie Provinces. It is composed of more than a dozen derivative output products that are available over the internet at http://www.agr.gc.ca/pfra/gis/gwshed_e.htm.
BACKGROUND
In 1970, as part of an International Hydrological Decade Study, the PFRA Hydrology Division undertook the task of delineating gross and effective drainage areas for catchments tributary to select active and discontinued hydrometric gauging stations in the Canadian Prairies. The resultant drainage area database was intended to provide the basis for updating regional flood and runoff studies.
Since the determination of drainage area is a fundamental basis for water resource assessments, government agencies and others involved in water resources were independently delineating drainage area boundaries to meet their individual needs. Not surprisingly, when such delineations were compared, they were often significantly different. Consequently, analyses based on such delineation discrepancies resulted in an added level of controversy. As the drainage delineation controversy increased, the need for a universally accepted drainage area database became more apparent.
In 1975, at the request of the Prairie Provinces Water Board, PFRA formally agreed to accept responsibility, on an ongoing basis, for delineating the gross and effective drainage areas above gauging stations on streams covered by the Apportionment Agreement. Furthermore, PFRA agreed to be the custodian of the database from which a set of standardized drainage area mylars (1:250,000 scale) and a tabulation of gross and effective drainage area values would be produced and provided to all potential users. These delineations were made in consultation with the Water Survey of Canada (Environment Canada) and representative agencies from the Provinces of Alberta, Saskatchewan and Manitoba. Over the years, the areal extent of delineation was gradually expanded to encompass the entire three Prairie Provinces.
In 1994, a decision was made to move the watershed delineations and the area calculation process into a digital environment. This decision was triggered by the time-intensive nature of the manual updating process, the deteriorating condition of the maps, and fiscal constraints. The process involved digitizing the drainage delineations and gauging station locations from nearly 3,000 maps, edge-matching the digital "pieces" into a single data layer and creating an automated process for calculating and summing the watershed areas (see Appendix A for details). The migration from paper maps and index cards to a Geographic Information System (GIS) environment was a significant milestone in improving the maintenance, accessibility, and usability of the database.
Subsequent to the GIS migration, some shortcomings were uncovered. To enhance the database, some "fictitious" stations were added, primarily at river mouths, to better match PFRA sub-basins to Environment Canada's sub-basin designations. As well, in 2004, it was decided to include watershed boundaries within northern Manitoba as described by Fedoruk (1970) to provide finer watershed definition.
The spirit of cooperation and commitment by all water resource agencies has created a unique and useful database that is used not only by government agencies, but also by a spectrum of non-government agencies, consultants and academia. Because of its wide acceptability, this database has been incorporated into a national product developed by Environment Canada.
CONCEPTSThe Watershed Project is based on the hydrologic concepts of gross, effective, and dead drainage areas.
The gross and effective drainage concepts originated with a paper by Stichling and Blackwell (1957) who indicated that "contributing" drainage areas on the Canadian Prairies fluctuate by year, by season, and by event because of the glacial landscape and the climate. Godwin and Martin (1975) restated Stichling and Blackwell's concepts of gross and effective drainage areas as follows:
"The gross drainage area of a stream at a specified location is that plane area, enclosed by its drainage divide, which might be expected to entirely contribute runoff to that specified location under extremely wet conditions. The gross drainage boundary is the drainage divide (i.e. the height of land between adjoining watersheds)."
"The effective drainage area is that portion of a drainage basin which might be expected to entirely contribute runoff to the main stream during a flood with a return period of two years. This area excludes marsh and slough areas and other natural storage areas which would prevent runoff from reaching the main stream in a year of 'average runoff'."
The Prairie region, being relatively flat, does not completely drain even in very wet years. Thus, the concept of dead drainage area was proposed by Godwin and Martin (1975) as follows:
"Drainage is considered dead if there is no outflow from an area even under very wet conditions. This situation is common on the Canadian Prairies where major depressions having sloughs and shallow lakes with no outlets are usually associated with dead drainage. A dead drainage basin includes all of the area tributary to such a depression."
Both the gross and effective drainage boundaries are portrayed as distinct lines in the delineation process, but in practice they are not. Generally, a gross drainage boundary is a distinct line because it is based solely on topography. However, in areas of poor drainage, gross drainage boundaries become less distinct and other physiographic factors such as slope, drainage patterns, and depressional storage are used as visual cues in delineating the boundary. Effective drainage boundaries are more conceptual because they pertain to the natural average runoff (approximately the two-year flood event) and are based more on hydrologic factors rather than on topography. Because of the non-distinct nature of the boundaries, an appropriate workable method for delineation was developed. A complete discussion of the drainage boundary delineation methods can be found in Hydrology Report #104 (PFRA Hydrology Division 1983).
The non-contributing area is the area that lies outside of the effective drainage demarcation (i.e. the area between the effective and gross drainage delineations). The portion of the non-contributing area that contributes to runoff in a particular event varies with the frequency of that event.
In the process of migrating the database to a GIS environment, a major conceptual change was made which involved the consideration of dead drainage areas. Previously (Hydrology Report #104, 1983), the five major dead drainage basins (Maple Creek, Old Wives Lake, Pakowki Lake, Quill Lakes, and Sounding/Eyehill Creek) were not considered to be part of any adjacent major drainage basin. That is, their respective areas were not included in the tabulated gross drainage area values of gauging stations in the external basin into which they would ultimately drain if water levels rose high enough. However, it was found that many (but not all) less significant dead drainage areas were included in the tabulated gross drainage area values of gauging stations in the external basin into which they would ultimately drain. Thus, a decision was made to provide a consistent approach by including all dead drainage areas in the tabulated gross drainage area values of their associated drainage basin.
- Spatial Representation Type
- vector data is used to represent geographic data
Comments (0 total)
Log in to add a comment