Station Analysis and Rating Documentation

1. Station Analysis and Rating Documentation Streamflow Record Computation using ADVMs and Index Velocity Methods Office of Surface Water

2. Documentation • Installation and configuration • Routine field inspections • Archival • Spreadsheet rating documentation • ADAPS • Station description • Station analysis • Office QA/QC plan

3. Installation Documentation • Document all installation parameters and configuration settings • Use form in Appendix 2 of T&M Report • Also store a configuration log or script file when programming ADVM

4. Routine Field Documentation • SWAMI • IV Gage Inspection Form

5. Routine Field Documentation • Describe the condition of cross-section • Are weeds, debris, scour, or fill at or near the site that affecting the flow? • Have the bank conditions changed (brush removed, heavy brush build-up, erosion)? • Taking pictures of the conditions is a convenient way to document conditions

6. Archival • Your office should have or develop an archival plan

7. Rating Workbook Documentation • Document steps you took to develop rating! • Others will need to check your work • Examples: “The range-averaged Vx had the highest R-square, lowest standard error, most significant p-values, and least pattern in residuals compared with other cells' Vx. Selected range-averaged Vx as the index velocity.” “Stage area rating 1.0 was developed using a standard cross-section located 1 ft downstream of the OSS. The cross-section was measured on Mar. 15, 2010 and used BM 2 as the origin. Elevations to datum for each station were rounded to the nearest 0.1 ft and entered into the AreaComp program. Min expected gage height = 12.0 ft; Max expected gage height = 39.1 ft. Gage height during survey = 21.3 ft ”

8. Rating Workbook Documentation • Good to include site photos

9. Rating Workbook Documentation • Site sketch – equipment, survey monuments

10. Class Question • What else could you document in the Rating Workbook?

11. ADAPS • Get all information into ADAPS • The parameter list can be long • Use 99968 for acoustic signal strength • Use 00055 for velocity • Use 99238 for cell end • For others use 999– parameters

12. Station Description Should include information to recreate the station if the ADVM is lost or moved. • ADVM configuration • ADVM type, frequency • Cell sizes, averaging interval, measurement period, etc • Get information from configuration log file • Exact location of the meter. An angle and distance from a reference mark may be helpful for this

13. Station Description, cont. • The height of the meter (in gage datum) in case the mount fails • A screen shot of a typical beam check • Velocity profile • Cross-sectional area figure • Store in SIMS or RMS – depends on your office’s preference

14. Station Analysis • Examples provided in Index-Velocity T&M Report, Appendix 8 • Non-tidal station • Tidal station • Store in SIMS/RMS

15. Station Analysis • Document • Stage and velocity record quality • Occurrence and reason for any missing data • Gage height corrections • Datum corrections • Velocity shifts • Rating analysis and ratings used • Periods of estimated data • Hydrographic comparison (if done) • Overall record quality

16. Let’s go over an example Station Analysis….

17. Elements of a Good Station Analysis • Full documentation and justification for shifts • Are they supported by measurements? • Are they supported by an observed channel condition or data quality problem in ADVM? • Separate sections for gage height and velocity data • Data quality problems in velocity record: changing cell end, obstructions, biofouling, etc • Full documentation of measurements used for rating development vs. validation

18. QA/QC Plan An office QA/QC plan should include: • Installation recommendations • Field procedures • Beam amplitude checks • Clock syncs • Temperature checks • 1-minute data during Qms • Stage-area rating validation • File archiving procedures • Data QA procedures An example QA/QC plan is provided with class materials

19. Questions?