Our colleagues at Technische Universität Graz have kindly produced some videos which show the following for the Amazon and Danube Basins
1. Computation of daily global gravity field variations from GRACE, known as the ITSG-Grace2014 solutions (itsg.tugraz.at/ITSG-Grace2014#daily)
2. Conversion to the amount of water that causes the same gravity field changes
3. Restriction of the global map to a specific river basin (in this case the Amazon and Danube)
4. The temporal plot shows the average value in the basin every day
