Request for new property - river water level (BODCNVS-1747) about p01

[roy-lowry]

Hi Dani,

I think river level gauges can be levelled against a terrestrial mapping datum. In the UK this is the zero height for Ordnance Survey maps which was - and I think still is - ODN (Ordnance Datum Newlyn), but each country will have their own, probably more than one. This is exactly the same as for tide gauges - see the whole raft of P01 codes starting with 'Surface elevation (' such as http://vocab.nerc.ac.uk/collection/P01/current/ASLVODNP/. There is cover in these for tide gauges that haven't been been levelled into anything (ASLVTGZP.

I think a similar set of P01 codes will be would be required for river levels, but the 'relative to instrument zero' generic code might be a good place to start.

[roy-lowry]

Light bulb moment.....

Couldn't 'Surface elevation (relative to instrument zero) of the water body by fixed in-situ pressure sensor' to a more generic 'Surface elevation (relative to instrument zero) of the water body' or if there was real pressure to do so with another instrument type appended cover the request for water levels in rivers? The P02 mapping then becomes a bit of an issue - how does one enable separate discovery of sea level and river level data???? Only way would be to map a subset of the Surface elevation codes to a broadened RVDS (broadening it makes me uncomfortable as it's really about fluxes across a boundary) but that's getting very ugly. Maybe one shouldn't be able to discover them separately through a description of what was measured? It can't be done for temperature or salinity.....