Hey, I am new to this website and have not yet have the chance to
see what had been posted previously. But I do have a doult that I
like to clear. There were a few studies carried out on a river
system to study the flooding problem.The big problem is that people
had been using surveyed data that had been related to a so
called "common datum". The river stretches over a distance of 120km.
The elevation ranges from 6m (MSL)(over the flood plain) to 1250m
(MSL)(head water). There is a likely hood that longitudinal profile
would be distorted due to the error in the survey. When using such
information for running model like ISIS or MIKE II, could the flood
level generated be used?

I will define "common datum". There are many BM used for tieing up
the river long. profile survey. It was assumed that they were all
related to mean sea level (MSL). But from information collected,
there can be a difference of 0.5 to 2 m between BM when related.

ALAN