Aquadop wave measurements in a shallow lake

I am currently investigating the exchange of water between a large shallow lake (40km x 20km x 3m) and slow flowing river.

I have the use of a Nortek 1mHz Aquadop Profiler and would like to measure wave data, in the lake near the mouth of the river.

Reading the "PUV-Wave measument " PDF from this site I noted the statement "The PUV approach is based on linear wave theory; occasionally situations arise where linear theory is no longer valid and second order effects become increasingly significant. Such situations occur when one attempts to improve the instrument’s response by placing it in increasingly shallower water. Long waves in shallow water become solitary, and hence have a nonlinear profile that is not accounted for by the PUV transformation."

If I have my Aquadop Profiler deployed in 2m of water would the wave data collected be of any use? i.e. will it be strongly influenced by non-linear effects.

If so, is there anything I can do about it?

What would be the best settings to use in a situation like this?

Hello Robert,

I think that the real issue here is that the waves that you are likely to be measuring are going to be short (period) and small (amplitude).  If this is the case, then both the signal is going to attenuate significantly with depth, and thus making it difficult to infer what is going on at the surface. 

However you are going to be in really shallow water (2 meters) so unless you hoped to measure waves that are 1 second or shorter, then you probably should be fine.  Just be aware that high frequency wave information will not be included in the overall estimates.

Attached is a plot showing what the minimum wave height must be in order to estimate waves for a given instrument deployment depth and wave period.  Please let me know if anything is unclear with this plot.  Note also that it only goes down to depths of 3 meters, but I suspect you can get an idea of what to expect.

kind regards,

Torstein