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Hello everyone!
As the use of non-contact flow measurement methods and satellite EO methods for river flow is expanding, the need to have river cross-sectional information available is also increasing…
So, does your, (or any other) agency (or projects) store ADCP transects in a form that they might be made available for use with non-contact methods? Alternatively, does your country or agency have a programme of mapping river bathymetry…?
@Daniel Wennerberg, do I remember something in Sweden?
I can say that in the UK, the Environment Agency has done a limited amount of bathymetry mapping, which combined with their complete coverage with aerial LiDAR (although only at 1 metre resolution) has enabled me to calculate discharge from a drone video. If you are interested to see the data access site, click this link.
https://environment.data.gov.uk/survey
If you draw a box round the Thames close to where the attached image shows (just west of London), you will find multibeam bathy in addition to the now nationwide LiDAR coverage.
Doesn’t matter if your sensor is a radar or a camera, on a bridge, a drone or a satellite, you need the cross-section…!
In addition to obvious interest as a river flow measurement nerd, I’m involved a project identifying in-situ data requirements and resources for Copernicus satellite missions.
I’m grateful for any thoughts you have….
And thanks to Kristoffer for telling me – in no uncertain terms!! – to move my email conversation to this forum!
Tell me things – help advance our science!
N.
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Hi Nick!
We do have a complete LIDAR scan of Sweden done by the swedish land survey. I think the average resolution is 4 points square meter, the DEM is in square meter resolution with the four points average to give the elevation.
Bathymetry is more scarce, some rivers have had cross sections mapped as part of local flood risk assessment projects and there is a compilation of data and available cross sections somewhere…
As for SMHI:
We store our measurements in WISKI, but there is not a complete bathymetry import from the ADCP-data. I think we get width and maximum depth, but that is all. We have historically rarely used GPS for ADCPs so there is not much geographical referencing available.
We do however do a fair bit of topo/bathy mapping for hydraulic modelling of rating curves.
I think bathymetry and surface alpha exports from Q-rev is in the pipeline, that could be quite useful if one would want to start building up a database of locations where a surface velocity measurement could be performed?
/Daniel
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Hi Nick,
Bathymetry for the mean cross-section is currently being exported as part of the XML file since QRev version 4.27. Starting with QRev 4.36 the velocity and temperature data based on MAP is now part of the XML. USGS uses Aquarius to store our field visit data which is limited to the data contained in the XML file. USGS is currently working on a Cross-Section database that will pull this data for every measurement in our database.
As Daniel mentioned, we are working on incorporating alpha and phi computations using SurfVelTool (https://code.usgs.gov/hydrologic-remote-sensing-branch/surface-velocity-tools/-/releases/1.0.0), now that it has been published, into QRev.
For more detailed cross-section creation (stitching multiple subsurveys together, adjusting multiple subsurveys to a common datum, comparing cross-sections, and computing channel characteristics) USGS is using AreaComp3. The application is currently in review and should be published later this year for official external use. AreaComp3 also has a tab for channel characteristics and documenting roughness by subsection so conveyance can be computed for the cross-section at specified stages.
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Thanks Daniel and Travis!
A couple of questions:
Daniel:
- Is the LiDAR data open data?
- Do you think the available cross-sections could be dug out?
Travis:
- Do you know if the cross-section output is there in QRevINT as well as USGS QRev? As installation is areal hassle with out IT policy now I do not update QRevINT with every new release, so am running 1.18 at present. I see area and width is output in the xml, but no detailed cross section info.
- Do you know when the cross-section database might go live?
- And would that data be open to users outside of USGS (such as Copernicus)
Oh, finally, are there any initiatives to enforce the use of GPS for ADCP data collection? I totally get that Q will most often be calculated based upon BT data, but the added value of the transects if they can be geolocated is such that I’d be keen to see GPS used wherever it is available (I was trying to push for this at the EA around the time I moved on…!)
Thanks again!
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Thanks Dave
That’s great! I hadn’t realised this was created as an output!
So, if we can get all the users to use QRev and GPS and create these output files we’ll be rapidly building up a really valuable dataset!
The Copernicus In-Situ folk might even be happy – I’m usually in trouble for heading off at too much of a tangent….!
Have a nice weekend!
Nick.
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Hi Nick (and everyone else),
Its great to hear that things are moving forward in the software side of things.
Nick: Elevation data is quite restricted in Sweden for what was until recently historical reasons…
I can however probably dig out the cross-sections which will include topography. I’ll put you in contact with one of our researchers who you’ve also met in Scotland, David Gustafsson. He is also a satellite guy so I’m sure you have a lot to discuss.
We are not likely to enforce the use of GPS anytime soon in Sweden, however, we are slowly moving towards using it a lot more often for the following reasons.
- Surface velocity
- Input to our flood forecast modelling
- QA/QC
Most of our RS5 measurements are being done with RTK-GNSS now even.
/Daniel
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