The surveying techinques that build a 3D model of a riverbed (photogrammetric/structure from motion or laser scanner) leave you with a nice and dense point cloud.
Sharing it allows your client to independently extract as many cross section as he or she wants to use in a hydraulic 2D flow simulation.
In a traditional surveying activity (made with a GNSS receiver or a Total Station) it may happen that the surveyor does not fix and measure elements that may be important for the hydraulic engineer.
But let me say that it often happens without any responsibility.
It’s hard to blame him.
The sensibility of two different tech freelance could be quite different.
With a 3D output, made of millions of close points, all the information needed for a consistent hydraulic study are there and always available.
However, it is important to make the client able to manage the data independently.
Otherwise it will be a continuous (and exhausting):
“Could you extract eight new cross sections here?”;
“Ah, and three more there?”,
“Could you make me the all profile of the riverbed?”,
“Oh no, not like that, i meant a little bit out from axis.”
For this purpose i use Potree.
It’s a LAS converter that takes your point cloud and transform it in a package of files, ready to be uploaded online.
Everything that your client will need is a browser, and an internet connection.
The model could be inspected and measured.
Cross sections are traced and exported in a CSV format, almost ready to be brought into a 2D hydraulics software, such as HEC-RAS.
This is the point cloud of a stretch of the River Calcandola, Sarzana my city.
It’s easy, it’s efficient and it’s so little time consuming.