Completion of Hydrometric Survey Notes (HSN)

Transcription

1 Completion of Hydrometric Survey Notes (HSN) Hydrometric Survey Notes provide a place to record results and applied proper procedures for tasks undertaken in the field, such as levelling, measurements, etc. They are the primary reference for all summary and site visit meta data and as such these notes must be fully completed before leaving the hydrometric station. This document provides guidance for the proper use of the two (2) standard sets of Hydrometric Survey Notes HSN s (Mid-Section Method and ADCP by Moving Boat Method) adopted by Water Survey of Canada. This document also contains definitions and contextual explanations for each field listed in the notes. It also provides examples of best practices. Generic Information These details apply to all visits and are thus found on all Hydrometric Survey Notes. Station Visit Identification The station identification number as well as the official station name listed in the Water Survey of Canada Reference Index must be entered along with the date on which the visit took place. 01AA002 February Daaquam River below Shidgel River Discharge Measurement The Start Time and End Time of the measurement are reported to the nearest minute. The Mmt Mean Time must be deduced from these values. Air Temp and W. Temp are used to report air and water temperature to the nearest degree Celsius. Information relative to the location of the discharge measurement is reported. Values for Width, Area and Mean Vel (velocity) of the cross-section are provided to help quality assess results for the specific deployment. The Corr M.G.H. (corrected mean gauge height) is reported to 3 decimal places. This value should be representative of conditions observed during the discharge measurement and contain all applicable corrections. The final Discharge measurement is reported and includes all appropriate corrections. The currently valid rating curve is identified (Curve #). With information on this curve, the observed water level and the water level corresponding to the observed discharge are used to calculate the shift away from the base curve (Calc. Shift Base Curve) and this difference is reported in metres. Also using this information, the expected and observed discharges are also used to calculate the percentage difference from the base curve (Difference Base Curve). 09:10 09: : Instructions for the Completion of Hydrometric Survey Notes Page 1

2 Stage Measurement Logger Time and corresponding water level sensor values (HG or HG2) are reported against a water level reference value (W.L. Reference) in each row. The exact source of this water level reference must be indicated on top of the corresponding column. Any applicable Sensor Reset Correction (S.R.C.) is deduced from the difference observed between these values. Note: If a time discrepancy is observed between the logger and a valid reference clock, then the difference must be identified in the Sensor Calibration tab described in the next section. The time correction required must then be applied prior to any other action. Preferably, the Weighted M.G.H. (mean gauge height) should be based on values from an observed water level reference. Under that scenario, and if Levels indicate a need, only a gauge correction (G.C.) must be applied to the Weighted M.G.H. in order to obtain a Corrected M.G.H. (mean gauge height) reported in the last row. If sensor values recorded by the logger are used to characterize the Weighted M.G.H., then if identified during the visit, both a sensor reset correction (S.R.C.) as well as a gauge correction (G.C.) may have to be applied to produce a Corrected M.G.H. EDT ECG 09: : Station Health / Gauge Maintenance Levels are used to report conclusions from Level Notes. Indicates: extent of correction (+ or mm), application of correction (yes or no), reference benchmark, and/or extent of level exercise (full benchmark check). Weather is used to report general conditions during the visit, typically related to cloud cover and precipitation. Wind strength and direction is also evaluated and reported. Battery Voltage is system voltage (unloaded) reported to the nearest one decimal point. Gas System information reported are: high pressure cylinder (Cyl.), low pressure Feed, and the sensor/orifice feed rate BPM (bubbles per minutes) or Rot (Rotation). Instructions for the Completion of Hydrometric Survey Notes Page 2

3 Other station maintenance information is reported to indicate an Intake Flushed, an Orifice Purged, a Downloaded Program or Downloaded Data. If data is downloaded, the start and end date for the Data Period is also indicated. Sensor Calibration Information reported in this table can be adapted. The Time for the observations is reported in the first column. In the first row, the name of a Sensor Reference of interest as per applicable SHEF code and the corresponding Observed Value is then listed below it. Time is one sensor which may require calibration for modem equipped sites. If a discrepancy is observed between the time reported by the logger and a valid reference clock, then each corresponding time must be reported in this table (how do we indicate when time is corrected? TBD: Show a completed example of each reset (sensor and time) for this table). Signature / Recording of Who was Involved in Field Trip Record all members of the Party involved in the field trip. Completed by is the person who entered the information into the notes and Checked by is the reviewer/checker. Level Notes The Station column identifies the element surveyed from (start and end of level circuit) or to (intermediate elevation observations, e.g. Turning points, BM s, Reference Points) B.S. (back sight) and F.S. (foresight) contain levelling rod readings. H.I. (height of instrument) and Elevation are computed (as found elevations of intermediate points within the level circuit).values. Additional details can be entered in the right column or the lower part of the sheet to denote additional details of the level circuit. Instructions for the Completion of Hydrometric Survey Notes Page 3

4 Mid-Section Method These notes are used for all instrument applications when a discharge measurement is done using the mid-section method (Price current meter, Sontek FlowTracker, and Sontel or RDI ADCP). Instrument and Deployment Information The Deployment method indicates if equipment was used by Wading, Bridge (upstream u.s. or downstream d.s.), Cableway, Boat or Ice cover. The distance (m, km) above or below gauge is reported. The Position Method indicates how the measurement location was maintained in reference to the surroundings (e.g. tagline/initial point as well as ENUF or XYZ for ADCP). The Method describes how data is generally sampled against the depth (e.g., Surface/.2/.5/.6/ or.8). The main Flow Angle (e.g. Perpendicular, varied) against the established measurement cross-section is reported and the correction Coefficient (e.g. 1.0 to 0.0) is also noted. The No. panels for all velocity observations is recorded. The instrument must be clearly identified by tracking the serial or meter number (Serial/Meter #). If using a current meter from a reel, notes must also report how the instrument is Located in metres above the specified lb/kg weight. If using hydroacoustics, indicate the ADCP Type, its transducers main Frequency, the Firmware and Software version used. Also track how the unit was Configured throughout the measurement (e.g. if done differently for each panel (Vary/Panel), handled Automatically, or Manually, listing special commands if applicable). Confirmations for testing and adjusting the internal time, electronics and compass are indicated with ADCP Set to Clock and Diagnostic Test and Compass Calibration tick boxes. The ADCP Depth is used to track of the distance in metres from the water surface to the zero point on the ADCP. Local information about the Magnetic Declination is required if using a GPS. Confirmation that data was deemed acceptable is tracked on the front sheet using the Passed Field Review tick box. Instructions for the Completion of Hydrometric Survey Notes Page 4

5 Note: Asterisk (*) on HSN fields indicates the parameters that are also entered into the measurement software during the measurement configuration or data acquisition and which should be verified during the QAQC procedure. Additional information beyond what is collected in the fields above may be entered in Remarks, such as an assessment of river conditions. Field Review Reviewing measurement results is required while in the field. The series of questions are designed to summarize quality assessment expectations. Quality criteria are successfully met when the technologist can answer questions positively. Otherwise, additional details should explain the deviation in the Review Comments. Questions apply to instrument types identified by C for Current Meter, F for Flow Tracker and A for ADCP. At the end, if results are deemed acceptable, the technologist communicates this conclusion by marking the Pass tick box. Passed All Instrument QAQC? Software Input Same as Notes? Diff in ADCP and Water T <2⁰C? Signal to Noise Ration > 4? Flow Angles Accounted for? Exposure Time / Location >40 s? Valid Ensembles / Panel >30? No Boundary or Spike Problem? The verification of internal electronics or spin tests must be successful. Information entered in software is identical to paper notes. The temperature measured by the hydroacoustic instrument must be precisely comparable to results from a thermometer. There must be sufficient backscatter in the water for information to be extracted from acoustic data. Corrections must be applied to mitigate angles between flow and the measurement cross-section, if appropriate. Data must be collected over a sufficiently long period to account for rapid fluctuations in flow and produce a trend. Enough valid data must be collected to build a statistically significant sample. Data must be free of obvious sampling error. Bed Contour as Expected for Site? Bathymetry results must relate to measurement site. Ice/Slush Depth as Expected? Velocity Profile Suitable? Water boundaries must reflect observed conditions. Variations in water velocity against depth and according to bed roughness and surface conditions must be accounted for. Instructions for the Completion of Hydrometric Survey Notes Page 5

6 # Panels > 20? Data must be sampled in at least 20 velocity panels. No Panel Q > 10%? Each panel must represent less than 1/10 th of the total flow. If appropriate, Notes on Site Conditions Affecting Measurement Quality can also be added. Manual Computation Sheet This section of the paper Hydrometric Survey Notes would only be used if all systems that can digitally record information failed and a manual sampling and computation is required. ADCP by Moving Boat Method These notes are used for all instrument applications when a discharge measurement is done using the ADCP moving boat method ( Sontek S5/M9 or RDI Work Horse/Stream Pro/River Ray ). Instrument and Deployment Information The Deployment method indicates if equipment was used by: Tethered-Bridge (upstream u.s. or downstream d.s.), Tethered-Cableway, Manned Boat or Remote Control boat. The distance (m, km) above or below gauge is reported. The position method indicates how the instrument location is tracked in reference to the surroundings (e.g. Bottom Track or GPS (GGA, VTG). Indicate the ADCP Type, its serial number (S/N), Frequency, the Firmware and Software version used. Also track how the unit was Configured throughout the measurement (e.g. handled Automatically, or Manually, listing special commands if applicable). Confirmations for testing and adjusting the internal time, electronics and compass are indicated with ADCP Set to Clock and Diagnostic Test and Compass Calibration tick boxes. The ADCP Depth is used to track of the distance in metres from the water surface to the zero point on the ADCP. Local information about the Magnetic Declination is required if using a GPS. Confirmation that data was deemed acceptable is tracked on the front sheet using the Passed Field Review tick box. Instructions for the Completion of Hydrometric Survey Notes Page 6

7 Note: Asterisk (*) on HSN fields indicates the parameters that are also entered into the measurement software during the measurement configuration or data acquisition and which should be verified during the QAQC procedure. Additional information beyond what is collected in the fields above may be entered in Remarks, such as an assessment of river conditions. Field Review Reviewing measurement results is required while in the field. The series of questions are designed to summarize quality assessment expectations. Quality criteria are successfully met when the technologist can answer questions positively. Otherwise, additional details should explain the deviation in the Review Comments. At the end, if results are deemed acceptable, the technologist communicates this conclusion by marking the Pass Field Review tick box. Passed All Instrument QAQC? Software Input Same as Notes*? Diff in ADCP and Water T <2⁰C? Smooth Ship Track? The verification of internal electronics, internal clock or compass calibration must be successful. Information entered in software is identical to paper notes. The temperature measured by the ADCP must be precisely comparable to results from a thermometer. Changes in boat direction and velocity must be optimized to produce the most accurate position dead reckoning. Also, precise ship tracking should not display large steps in position data. Boat Speed < Water Speed? The boat velocity must be kept slower than water speed to avoid the creation of ambiguity velocities in computed data. Pitch, Roll < 5⁰? The ADCP should remain close to vertical as depth is not corrected accurately beyond 5⁰. No Ambiguity Velocity? Data must be free of obvious sampling error. There should be few outliers in water velocity vectors relative to angle and magnitude. Good Differential GPS Quality? If appropriate, GPS must be of a quality adequate to replace bottom track data as a position reference. Bed Contour as Expected for Site? Bathymetry results must relate to measurement site. Instructions for the Completion of Hydrometric Survey Notes Page 7

8 Measured Q > 50%? Missing Data < 10%? Missing Data Distributed? Proper Edge Mmt Method? Each Edge < 5% of Total Q? Velocity Profile Suitable? Reciprocal Pair? Moving Bed Corrected If Any? Directional Bias < 5%? Total Exposure > 720s? Standard Deviation / Mean <5%? Sampled data should provide a significant portion of the crosssection. Too high a percentage of missing data denotes sampling conditions marginal for instrument performance. A large area of missing data will require the estimation of flow which may be based on insufficient information to be accurate. Flow estimated at the edges must be based on measured inputs and account for eddies and other disturbances as per best practices. Uncertainty produced by the estimation of flow at the edges must be kept low. Variations in water velocity against depth and according to bed roughness and surface conditions must be accounted for. An even number of transects must be produced traveling from each side to avoid directional bias in measurement results. A moving bed test must be done for each measurement and a correction or mitigation applied if required. A directional bias greater than 5% may indicate some problem with the compass or other deployment challenges that should be further investigated. The measurement must be based on at least 12 minutes in order for the sampled data to fairly capture the trend for the flow measured. The variation in transects collected should provide good confidence that the measurement is precise and can be reproduced. If appropriate, Notes on Site Conditions Affecting Measurement Quality can also be added. Data Collection Details Describe the type of Bed Material and the type of MB (moving bed) Test Done (Loop or Stationary) and the results in % Detected. Indicate the Track Ref Selected*. Record the description of both the Left Bank and the Right Bank shape as well as the Edge Dist Mmnt Method used. Note: Asterisk (*) on HSN fields indicates the parameters that are also entered into the measurement software during the measurement configuration or data acquisition and which should be verified during the QAQC procedure. Each transect must be described using its Transect ID, specifying the Start Bank*, the Start Time* and the Start Distance (m)* and End Distance (m)* with accurate measurements. The Raw Discharge (m 3 /s) for each transect must be recorded. If necessary, Remarks should include any other pertinent information. Instructions for the Completion of Hydrometric Survey Notes Page 8

9 The time of the first transect must be noted in Mmnt Start Time. The Mmnt End Time* must be manually observed and noted and the calculated Mmnt Mean Time recorded. The calculated Raw Discharge Mean (m 3 /s) is recorded, the calculated MB Correction Applied (m 3 /s) is recorded and applied which will result in the Final Discharge Mean (m 3 /s). The Corrected Mean Gauge Height (m) is reported to 3 decimal places. This value should be representative of conditions observed during the discharge measurement and contain all applicable corrections. The Base Curve Gauge Height (m) is the corresponding gauge height from the base curve for the Final Discharge Mean (m 3 /s). The Base Curve Discharge (m3/s) is the corresponding discharge determined from the base curve for the Corr. Mean Gauge Height. The Standard Dev/Mean Discharge (%) is taken from the measurement summary and is based on selected transects used. The Calc. Shift Base Curve (m) is the difference in metres between the observed water level and the water level corresponding to the observed discharge and represents the shift away from the base curve. The Discharge Diff. Base Curve (%) is the difference in percent of the expected discharge as determined from the Corr Mean Gauge Height (m) reference to the base curve and observed Final Discharge Mean (m 3 /s) discharge are also used to calculate the percentage difference from the base curve. The last 6 boxes are important information that all gets transferred to the front sheet of the HSN. Instructions for the Completion of Hydrometric Survey Notes Page 9