The IAHS together with other organisations are currently compiling a list of unsolved scientific problems in hydrology. The discussion on the linkedIn forum is here https://www.linkedin.com/groups/13552921
This splinter meeting will further the discussions in preparation for the VCSS on Saturday http://www.waterresources.at/index.php?id=5&tx_ttnews[tt_news]=20&cHash=4d614de667fc26c1de6a433ab02062a5