Hydrological modelling of the Okavango Delta: A basis for

Umbgrove Lecture
Hydrological modelling of the Okavango Delta: A basis for management
Professor Wolfgang Kinzelbach
Institut für Umweltingenieurwissenschaften
ETH Zurich
November 2, 2009-10-16
Grote College Zaal
Het gebouw Aardwetenschappen
Budapestlaan 4, De Uithof, Utrecht
Wolfgang Kinzelbach, Christian Milzow, Lesego Kgotlhang, Peter Bauer-Gottwein
Since 1900 about half of the wetland area of the world has vanished together with its immense
biodiversity and other ecological services. The pressure on the remaining wetlands is high and
conservation and management have to be reconciled in order to preserve their functions. Here
the Okavango Delta is considered, which is recognized as a wetland of global importance.
The hydrological drivers of the Delta are described and a model is built, which is capable of
simulating the annual flooding and drying up of the Delta. It relies heavily on remote sensing
data. An aspect related to the hydrology is the salt deposition on islands, which essentially
keeps the swamp waters fresh. The mechanism is elucidated using geophysical methods.
Finally the model is applied to management options and a climate change scenario. It is
argued that the riparians have to be remunerated for custodian services, if the Delta is to thrive
in the future.