Abstract: Routine monitoring at fixed sites can not represent temporal and spatial water quality patterns of a river system thoroughly. An integration of GIS data and onboard realtime water quality monitoring might be useful to obtain detailed information of water pollution continuously. The water quality measurement results of standard method and realtime monitoring method were highly correlated in our study, so that validating the reliability of onboard monitoring. In situ investigation in a division of WenRui Tang river network showed remarkable resolution of water quality characteristics has been described by onboard realtime water quality monitoring, so that facilitating monitor on dispersed point pollution sources. The integration of GIS data and onboard realtime water quality monitoring can be compensation to fixed sites routine monitoring．

Key words: onboard realtime water quality monitoring, GIS, dispersed point pollution