Edit stage discharge data
Gage Zero Data
The hymosData Edit and Entry function <Gage Zero Data> allows you to enter and edit values of the Gage Zero. It also supports you in keeping track of changes in the height of the gage.
Flow measurements^image043.gif!
The information stored includes:
- Station ID,
- period the gage zero is valid for (double-click to change date, or edit in the date text field),
- Gage Zero height in m + Datum of Elevation,
- Datum of Elevation.
Press <Save> to save the entered information in the database, <Delete> to delete a Gage zero from the database, <Close> to leave the window without saving.
The Gage Zero data will be used when entering Stage-Discharge data.
Add stage discharge data
By stage-discharge data is meant condensed results of flow velocity measurements, i.e. stages and discharges, to be used for the establishment of stage-discharge relations.
Discharge rating curves in hymosare of the following types: - simple stage-discharge relation
- stage-discharge relation with unsteady flow correction
- stage-discharge relation with constant fall backwater correction, and
- stage-discharge relation with normal fall backwater correction.
Depending on the envisaged computational procedure for the rating curve in some cases following parameter(s) should be added to stage and discharge: - gradient or fall, if unsteady flow, respectively backwater correction is required
- cross-sectional parameters, if the rating curve has to be extrapolated beyond the measured range
With gradient the time rate of change of the water level during a measurement in m/day is meant, whereas fall is the water level difference in m between the base station and a second station in the backwater zone.
The stage-discharge data can be entered by: - importing data from file, or
- via the screen.
Start the function by selecting from the Data Edit and Entry functions <Stage Discharge Data>. When you select a station from the <Station codes> list box hymoswill present in the dates list box all Stage-Discharge data found in the database for the selected station within the selected time period. From the dates list box you can select a date (with observation number) to edit. If you want to add a new record press <Add New>. After editing data press <Save> to save your changes to the database. If you want to save a record with a measurement date and observation number already existing in the database hymoswill ask you if you want to overwrite the existing record. If not Hymoswill not save your changes before you changed the measurement date or the observation number.
Flow measurements^image045.jpg!
A current metering data-record comprises at least the following data: - Date of the measurement : year, month, day
- Number of the observation : unique number in a day
- Zero level of the gauge : in m + M.S.L.
- Water level (h) : weighted average water level during the discharge measurement (m)
- Discharge (Q) : in m^3^ /s
- Width : width of the cross-section at the water surface (m)
The following data is not obligatory , but advised to fill in.
- Gradient (dh/dt) : in m/day (mind the sign! ) (if the unsteady flow correction is to be applied)
- Fall : in m (if you selected backwater correction)
- Wetted perimeter (P) : in m
- Cross-sectional area (A) : in m^2^
- Surface Slope (s) : m/m
- Hydraulic Radius : m (computed from R = A/P)
- Velocity (v) : m/sec (computed from v = Q/A)
- Manning's N : (computed from R, s and v)
- Mode of Crossing : 30 characters
- Method of velocity observation : 30 characters
- Number of verticals
- Maximum point velocity: m/sec
- Weather condition : 30 characters
- Wind velocity : km/hr
- Wind direction : Degrees
- Remarks : text
- Flag : yes/no included in rating curve calculation.
To import existing Stage-Discharge data from file, press <Import QH> and select the filename with your Stage-Discharge data.
The stage-discharge data file should have following layout:
Line 1
- Station code (format A10) and in column 11: G, F or N:
- if gradients are included
- if fall data are included
- if neither gradient not fall data are included
Line 2
- year, month, day of the measurement
- number of the measurement
- gauge zero (m + M.S.L.)
- water level (m)
- discharge (m^3^ /s)
- gradient (m/day) or fall (m) if G res. F is entered in line 1
- width (m)
- wetted perimeter (m)
- cross-sectional area (m^2^ )
- etc. for the next lines.
Note
- All data should be separated by comma's or blanks. To break off a record (if e.g. the last terms are not available) use /; the omitted values will then be set to the default = 0.
- The data should be in si-units.
Example
Stage-discharge data of station backwt including fall. The records are broken off after the fall. The water levels in this file as well as in the time series are given relative to gauge zero; hence no shift is required and the gauge zero can remain 0.0. The layout of the data file is shown below.
backwt f
1990 1 1 1 0.0 5.907 1160 1.917/
1990 1 3 2 0.0 7.105 1520 2.182/
1990 1 3 3 0.0 5.026 889 1.597/
1990 1 8 4 0.0 7.013 1490 2.225/
1990 1 10 5 0.0 11.558 2830 2.880/
1990 1 11 6 0.0 8.108 1640 1.920/
1990 1 17 7 0.0 8.638 1990 2.652/
1990 1 18 8 0.0 3.139 399 0.808/
etc.
Edit Rating Curves
Calculated or manually entered rating curves can be edited through the <Edit Rating Curves> function of the Entry and Edit function map. It is also possible to add new rating curve functions within this form, computed manually ore within other programs.
Flow measurements^image047.jpg!
Select a station from the Station codes list box and a rating curve type from the list box below the station list box. HYMOS will now try to find rating curves in your database for the selected station and rating curve type. If rating curves are found, the relation is shown in the <Rating curves> list box. A relation consists of a start and an end date of the validity period of the rating curve. When a rating curve function is selected from this list box, the values of the parameters are shown in the spreadsheet below it, together with the type of equation. The values of the rating curve can be edited and saved to the database again, also the validity period of the rating curve can be changed. Make sure that HYMOS does not accept that the validity period of rating curves overlap for one station.
Through this function it is also possible to add a new rating curve. To do so press the <Add new> button to remove all entered parameters, select a rating curve type, an equation type and enter the valid parameters. After completion, press the <Save> button to save the relation to the HYMOS database. Make sure the entered parameters are valid, HYMOS does not check the entered relation for extreme parameters.
Press <Save> to save the entered or updated information to the database. Press <Delete> to delete a selected rating curve from the database. Press <Close> to leave the edit rating curves function without saving.
