Gertjan Geerling1,3, Ellis
Penning1, Christine Rogers1, Cindy
van de Vries - Safavi Nic1, Valesca
Harezlak1, Stanford Wilson2,
Gennadii Donchyts1
1Deltares, Delft, The Netherlands
2Rijkswaterstaat-WVL, Lelystad, the Netherlands
3Institute for Science in Society, Radboud University,
Nijmegen, the Netherlands
Corresponding author: Gertjan Geerling email:
gertjan.geerling@deltares.nl
Acknowledgements
This research was funded by the research programme of the Dutch National
Water Authority (KPP-Corporate Innovation Programme and the KPP-
Innovative Monitoring). We thank the valuable discussions with the
Floodplain Management Team of the National Water Authority (RWS-ON) and
all other contributing stakeholders.
Abstract
In deltas, rivers are often embanked and have a limited discharge
capacity. In case these rivers also have a fixed riverbed for
navigation, vegetation succession in the floodplains will reach climax
stages. This leads to increasing hydraulic roughness that lowers the
discharge capacity and prompts the river manager to intervene in the
floodplain vegetation. The Dutch river manager depended on a 6-year map
cycle of manually digitized aerial photographs for assessment of the
state of hydraulic resistance. As the amount of agriculture in
floodplains is receding in favor of nature rehabilitation projects, the
vegetation dynamics increase. At the same time, the bigger floods were
anticipated in the future. Therefore, more up-to-date floodplain
vegetation maps with a short processing time were needed for about 500
kms of river in the Netherlands. We present an operational web-based
monitoring tool that analyses sentinel-2 data on the fly though Google
Earth Engine to provide an overview of the current state of the
vegetation in the entire floodplain area of the Dutch river systems
Rhine and Meuse. It is the first satellite-based application in an
operational setting for the Dutch National River Manager
(Rijkswaterstaat). The tool compares a map of allowable vegetation with
the remotely sensed current situation for a quick scan of hotspots and
can create reports on the cadastral (landowner) level. We describe the
results of the image classifications and the role of this tool in the
full process of the Dutch flood risk management process.
Keywords: river management, vegetation, vegetation succession, remote
sensing, open data, google earth engine