There surely is a technique but I assume it is in the field of civil engineering,or water engineering, sewage design, not a typical task we (architect, urban planners) do really. Also you maybe able to find useful papers or articles in landscape design I assume or environmental engineering(environmental measurements) . Look in those kind of disciplines, you may find more answers. 

I am NOT much related to this topic..yet I was having a document on waterfront implementation. You can scroll through it; if it is of help, my pleasure!

as per my perception,what may be the relativity you may find,

influenced depth of water in water body(river),that may be the difference of first depth at some time and second depth at other time ,this may be done by sounding at that time or putting bumboo line marker to see the difference. 

Thank you every one for your answers.

Actually I am looking for some statistical method or planning technique which could be helpful to delineate the waterfront zone.

I got one statistical method known as ANALYTICAL HIERARCY PROCESS, but I couldn't figure out its implementation for zoning.

This is a very interesting topic (I actually wrote an article about it - "The definition of riverfront: contribution to a conceptual and spatial delimitation"). Please, can you tell us about your findings on those statistical methods?

Article A definição de frente ribeirinha: subsídios para uma delimit...