The technology for integration of mathematical models and on-line monitoring has been
available for almost a decade and the use of mathematical models for forecasting of flow
has been adopted worldwide. When it comes to surveillance and early warning systems
for water quality the coupling of pollutant sensors with mathematical models in real time
has only recently been introduced, one reason being that the available technology for
online monitoring of water quality was limited to a few components only. However, in
line with the rapid development in on-line sensor technology the possibility of coupling
on-line
monitoring
with
state-of-the-art
water
quality
modeling
techniques
and
forecasting is now available. A prerequisite for such a system is a data assimilation
routine to update the models in real time and hence minimize the difference between
measurements and model simulations. Indeed the forecasts of pollutant concentrations
ahead in time require an updated model at all times. In this context the Kalman filtering
techniques have proven to be very efficient. In particular the Kalman filtering updating
algorithm may be structured in such a way as to provide information on the amount and
location of the pollutant updating. The latter is a key issue when tracing pollutant
sources.
This paper presents the above elements integrated into a real time decision support
system for water quality in the complex canal system in Bangkok.