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Impact of climate change and anticipating flood management strategy on floodplain ecosystems of the River Rhine, The Netherlands. Marjolijn Haasnoot, Harm Duel, Guda van der Lee, Martin Baptist, Diederik van der Molen, Maarten Platteeuw WL | Delft Hydraulics, RIZA. anticipate. yes in 1920!.
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Impact of climate change and anticipating flood management strategy on floodplain ecosystems of the River Rhine, The Netherlands Marjolijn Haasnoot, Harm Duel, Guda van der Lee, Martin Baptist, Diederik van der Molen, Maarten Platteeuw WL | Delft Hydraulics, RIZA anticipate yes in 1920! But I used to be the best student Trees will get ‘stress’
Introduction • Dutch rivers are highly regulated by dikes and dams • Climate change will have impact on functions like agriculture, urban areas, shipping and nature • Measurements are needed: eg. more room for the river by Cyclic Flood Rejuvenation (CFR) to deal with higher discharges What is the impact of climate change and anticipating flood management strategy on the ecosystem of the River Rhine in the Netherlands?
Method 1 – climate change • As a result of climate change precipitation is expected to increase. River Rhine will get higher discharges in winter and lower in summer current situation or climate 2050 RHINEFLOW hydrological model river discharge elevation map flood duration map GIS ecotope map HABITAT spatial analysis tool habitat suitability map
Method II – Cyclic Flood Rejuvenation (CFR) • Natural floodplain vegetation increases the hydraulic roughness: water levels increase • CFR: recurrent removal of vegetation and sediment to guard flood safety SOBEK 2D hydrological model water levels sedimentation Every 5 years: if critical water level is exceeded, then CFR measure. until 2050 flood duration map ecotope map HABITAT spatial analysis tool habitat suitability map
Effects of climate change scenarios • acreage hardwood forest, river dune, natural levee pasturedecreases • acreage softwoord forest, natural levee hayfield, natural river bank increases • effect on habitats and species total area ecotopes x 1,000 ha for climate change in 2050
Effects of flood management strategy: CFR • Room for river: excavation floodplain and removal of forest (CFR) • after implementation vegetation succession: bare soil, grass- haylands to forest • effect on habitats and species
after years Change of habitat suitability for the Corn crake after CFR The breeding habitat of the Corn crake (Crex crex) is situated in grasslands that are rich in structure. Following flood prevention measures, the habitat suitability first increases. However, the grasslands will be gradually replaced by softwood forests and subsequently, the suitability will decrease again.
Impact climate change and CFR change area (x 1,000 ha) suitable habitat CFR after 20 years CFR after 50 years CFR after implementation climate change
Discussion • In this study we looked at indirect effects (through hydrology) of climate change. Direct effect can also be expected eg. by a rise of temperature and CO2 • However, hydrology is important factor influencing habitats along rivers • More management strategies could be considered
Conclusions • Climate change has a significant effect of ecotopes and habitats along the River Rhine • However, effects of anticipating flood management strategies, like CFR might be more important • A shift in management practice in floodplain may be very beneficial for ecological quality of the floodplains (consider time and spatial distribution) anticipate