Inspired by the famous list of unsolved math problems (hence the header image), the International Association of Hydrological Sciences has an interesting challenge for us all: define 23 unsolved problems in hydrology:
The International Commission on Groundwater is going to submit a few problems via the LinkedIn forum. A few of us at Water Underground are going to put our thinking caps on and submit a problem or two. If you would like to be part of the discussion very early in 2018, get in touch with Tom Gleeson.