Analysing how renaturation measures influence flood risk in Munich

Analysing how renaturation measures influence flood risk in Munich#

Idea#

  • flood analysis for Isar in Munich before and after renaturation (Isar-Plan) -> calculate how flood risk and the ratio of vegetation and constructed area in risk of flooding changed -> maybe include faster infiltration due to vegetation areas changing?

Data#

  • Landsat data (before renaturation and after, additionally one during flood event as reference for parameters)

  • DGM (ideally before and after to see changes that might be related to renaturation)

  • buildings from OSM?

  • OSM data for creating a map

Method/Implementation#

  • derive vegetation areas from landsat images (before and after renaturation) using the NDVI -> reclassify different vegetation types

  • calculate the TWI for the situation before and after -> use real flooding event as reference –> use index (maybe NDVI as well) to filter water areas

  • import OSM buildings -> check which number of buildings are located in flood risk area

  • check how vegetation area in flood risk area changed

  • maybe find a way to include infiltration?

https://grasswiki.osgeo.org/wiki/Natural_Hazards https://grasswiki.osgeo.org/wiki/Hydrological_Sciences

FOSSGIS tools#

  • GRASS GIS for the analysis -> r.topidx (for twi) -> i.vi (ndvi using near ir and red bands) -> r.reclass (reclassifying based on raster layer) -> r.threshold / r.watershed (for stream/infiltration)? -> r.hazard.flood (fast detect flood prone areas) -> animation tool for comparing different scenarios etc?

  • gdal for looking at metadata like the crs -> info commands

  • QGIS for designing maps

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