Explanation of the criteria for classification and numbering of components    E88.1.01
(DEC 99)
Explanation of the dates on the component's description



1.   Purpose and objectives

     To carry a line-of-levels from a permanent bench mark to a gauging station bench mark.

2.   Description

     To obtain accurate and reliable stage data, the station bench mark must be referred to a fixed datum. This datum could be established by the Geodetic Survey of Canada or another organization. If the station is not close to established bench marks, bench marks are established close to the 
gauging station and assigned an arbitrary datum. The stage must be related to these bench mark datums by running a line-of-levels.

3.   Input

     Elevation of starting point.

4.   Output

     Elevation of finishing point.

5.   Operational requirements and restrictions

     Levelling parties require trained technical persons.

6.   Form of presentation

     Published report :
     Terzi, R.A.  1972. Hydrometric Field Manual - Levelling. Inland Waters Directorate, Water Resources Branch, Ottawa, Canada.

7.   Operational experience

     Levelling has been carried out for years by Water Survey of Canada and other organizations.

8.   Originator and technical support

     Water Survey of Canada
     Atmospheric Environment Service
     Environment Canada

9.   Availability

     From the HOMS National Reference Centre for Canada.

10.  Conditions on use

     Free. Full acknowledgement of use is expected.

(First entered: 15 JAN 81

Last updated: 14 DEC 1999)