International Workshop / Expert consultation Extreme Discharges 18. and 19. April 2005, Bregenz, Austria Large scale simulation of land use change effects on floods in the Rhine (results from the LAHOR-project) Bronstert, A.1,2, Bárdossy, A.3 Buiteveld, H.5, Disse, M.6, Engel, H.4, Fritsch, U.2, Hundecha, Y.3, Lammersen, R.5, Niehoff, D.2, Ritter, N.4 1 University of Potsdam, Institute for Geo-Ecology, Chair for Hydrology & Climatology, Germany 2 Potsdam Institute for Climate Impact Research, Germany 3 University of Stuttgart, Institute for Hydraulic Constructions, Germany 4 Federal Institute for Hydrology, Koblenz, Germany 5 RIZA, Arnhem, Netherlands 6 University of the Armed Force, Munich . IW S RIZA Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Major land-use changes in the Rhine basin during the last century 1000 ha 1) Urbanisation 2100 agricultural used area 1800 ¾ doubling of urban areas 1500 forest (housing, industry, traffic etc.) 1200 arable land 900 during the last 60 years grassland, meadows 600 300 ¾ Example: Körsch-Catchment urban area 0 1850 Î 1990 1938 40 45 50 55 60 65 70 75 80 85 88 Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Major land-use changes in the Rhine basin during the last century 2) decentralised management urban storm water ¾ retention on roofs etc. ¾ Small scale retention in the landscape Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Major land-use changes in the Rhine basin during the last century 3) change in management practice of farm land ¾ conventional tillage vs. Ecological oriented tillage ¾ rationalisation of farm land Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Major land-use changes in the Rhine basin during the last century 4) river training and river channelling ¾ faster flood wave propagation ¾ reduced retention in flood plains Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment The modelling concept 1) storm runoff generation influenced by different land use Î meso scale hydrological modelling in selected sub-catchments 2) regionalization of runoff generation Î macro scale hydrological modelling in all sub-catchments 3) flood routing and retention in flood plains Î hydrodynamic routing in the main river system Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment The modelling approach: nested and scale-specific models Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results I The Lein Sub-Catchment: Area: 115 km² Location: Kraichgau (SW-Germany); land use: intensive agriculture Rotterdam Arnhem Lenne soils: deep loess soils (A E = 455 km²) hydrological model: extended WASIM-ETH Köln Wiesbaden Mainz Lein (AE = 115 km²) Karlsruhe Körsch (A E = 127 km²) Strasbourg Basel Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results I: The Lein sub-catchment Simulate storm runoff after (a) a convective rain event (b) an advective rain event; present land use and urbanisation scenarios Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results I: The Lein sub-catchment Convective rainfall events Advective rainfall events Saturation excess Saturation excess infiltration excess Sewage channel Sewage channel infiltration excess excess excess xxx Subsurface Slow ground- storm flow Slow groundwater flow Subsurface storm flow water flow Lein-sub-catchment: runoff generation processes for different rainfall event types Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results I: The Lein sub-catchment Simulated increase in runoff volume and peak (advective events) due to a 50% increase of settlement and industrial areas in the Lein catchment; the events are sorted by the urbanization impact on runoff volume Year, month Increase in runoff Simulated baseflow Duration Return period compared to present contribution to [h] approx. [a] conditions volume [%] Maximum [%] Volume [%] 1990, February 3,4 3,7 19 150 2 1993, December 5,9 2,7 17 250 8 1997, February 3,9 2,7 19 150 7 1982, December 1,7 1,5 27 225 3 1983, May 0,6 0,9 39 300 4 1988, March 0,0 0,0 52 650 3 Mean 2,6 1,8 29 290 4,5 Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results II: The Lenne sub-catchment The Lenne sub-catchment Area: 455 km² Location: Sauerland (W-Germany); Rotterdam Arnhem Land Use: mainly forest and pasture; few settlement Lenne (AE = 455 km²) soils: shallow, permeable Köln hydrological model: extended WASIM-ETH Wiesbaden Mainz Lein (AE = 115 km²) Karlsruhe Körsch (A E = 127 km²) Strasbourg Basel Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results II: The Lenne sub-catchment Simulate storm runoff after an advective rain event: present land use and urbanisation scenarios Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results III: Regionalization of runoff generation Rhine basin from Maxau to Lobith: Area: 110 600 km² hydrological model: extended HBV-IWS (extended for urban areas, specific parameterization of storage processes for different land-use) catchment sub-division: 96 sub-catchments 12 major sub-catchments hydro-meteorological data base: 1514 precipitation stations 313 climate stations Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results III: Regionalization of runoff generation a) Summer 1983 event b) Winter 1995 event 1800 12 0 0 Present condition Double urban area 1600 Double urban area 10 0 0 Present condition 1400 Co mplete fo res t co ver c o m ple te ly fo re s t c o ve r Scenario 2010 Scenario 2010 1200 800 1000 600 800 600 400 400 200 200 0 0 15.01 20.01 25.01 30.01 04.02 09.02 14.02 20.05 23.05 26.05 29.05 01.06 04.06 Date Date Neckar catchment (Gauge Rockenau, 2,665 km²) Simulated runoff for different land-use scenarios due to an intense summer rainfall of shorter duration and a winter precipitation of lower intensity and longer duration Multi-scale Modelling of Anthropogenic Effects on Floods in the Rhine Catchment Results IV: Effects of land-use changes on the macro-scale River network from Maxau to Lobith: total length of simulated river stretches: ~ 1100 km routing model: SOBEK (1D-fully hydro-dynamic) SYNHP (hydrological routing) 42 simulated scenarios: ) land-use change ) extreme precipitation scenarios ) retention in polders and flood plains Lobith [862.2] Rees [837.4] Multi-scale 17 Rhine 16 Lippe [814.50] Modelling of W esel [814.0] Emscher [797.80] M odel nodes [Rhine km] Anthropogenic 15 Course of river R uhrort [780.8] Effects on Ruhr [780.10] V arious tributaries [R hine km ] 14 Intermediate catchment area left/right Floods in the Düsseldorf [744.2] Intermediate catchment area left Rhine Erft [736.55] Intermediate catchment area right 13 W upper [703.30] Catchment Ground water Cologne[688.0] Sub-models, see separate layouts 12 Sieg [659.4] The Bonn [654.8] Rhine 11 Ahr [629.45] W ied [610.20] Saynbach [599.9] River: Andernach [613.8] 9 N ette [608.70] 10 M osel [592.3] river nodes Lahn [585.7] SOBEK model 8 8 and M osel [592.3] W isper [540.30] Kaub [546.2] stretches; 7 M ainz [498.3] SOBEK model 7 M ain [496.6] Nahe [529.1] Main groundwater [496.6] Selz Nahe 5 and [518.80] M odau [473.70] [529.10] 6 Random tributaries: catchment (IC A = interm ediate catchm ent area) 1: ICA left/right Maxau Rhine km 362.3 – Speyer Rhine km 400.6 W eschnitz [454.70] 2: ICA right Speyer Rhine km 400.6 – Rhine km 410. 0 W orm s [443.4] 3: ICA Rhine km 410.0 – Mannheim Rhine km 424.9 4 inflows 4: ICA left/right Neckar Rhine km 428.2 – Worms Rhine km 443.4 4 5: ICA left Worms Rhine km 443.4 - M ain Rhine km 496.6 SOBEK model 6: ICA right Worms Rhine km 443.4 - M ain Rhine km 496.6 Neckar [428.2] N eckar [428.2] 7: ICA right M ainz Rhine km 498.3 – Kaub Rhine km 546.2 3 8: ICA left/right Kaub Rhine km 546.2 – Lahn Rhine km 585.7 9: ICA right M osel Rhine km 592.3- Andernach Rhine km 613.8 2 10: Ground water Neuwieder basin Speyerbach [400.20] 11: Ground water Andernach-Bonn 12: Ground water Bonn-Cologne Queich [384.80] 1 13: Ground water Cologne-Düsseldorf 14: Ground water Düsseldorf-Ruhrort 1 Pfinz [380.70] 15: Ground water Ruhrort-Wesel 16: Ground water Wesel-Rees Alb [371.20] 17: Ground water Rees-Lobith Maxau [362.3] Retention area Volume Operation 6 3 Name Position (Rhine km) [10 m ] Multi-scale Upper Rhine Wörth/Jockgrim/Neupotz 368 Moving the dike back and retention polder* 16.2 (12 +4.2) Modelling of Elisabethenwört 381.3 – 383.0 Retention polder* 11.9 Anthropogenic Mechtersheim 388.4 Retention polder* 7.4 Effects on Rheinschanzinsel 390.4 Retention polder* 6.2 Floods in the Flotzgrün 392.6 Retention polder* 5.0 Kollerinsel 409.9 Retention polder* 6.1 Rhine Waldsee/Altrip/Neuhofen 411.5 Moving the dike back and retention polder* 9.1 (7.9 +1.2) Catchment Petersau/Bannen 436 Moving the dike back 1.4 Worms Bürgerweide 438 Moving the dike back 3.4 Mittlerer Busch 440 Moving the dike back 2.3 The Bodenheim/Laubenheim 490 Retention polder* 6.4 Ingelheim 517 Retention polder 3.8 Rhine Total for Upper Rhine below the Maxau gauging station 79.2 River: Lower Rhine Cologne-Langel 668.5 – 673.5 Retention polder 4.5 Worringer Bruch 705.5 – 708.5 Retention polder 8 simulated Monheim 707.5 – 713.5 Moving the dike back 6.9 retention Itter-Himmelgeist 723.5 – 727.5 Moving the dike back 2 Ilvericher Bruch 750.5 – 754.5 Retention polder 8.1 measures on Mündelheim 760.5 – 769.5 Moving the dike back 3 the Rhine Orsoy Land 797.5 – 803.5 Moving the dike back 10 below the Bislicher Insel 818.5 – 823.5 Raising the dike - Lohrwardt 832.5 – 833.5 Moving the dike back and retention polder 12.9 (10.3 +1.6) Maxau Grietherbusch 837.5 – 847.5 Dike adaptation - gauging Bylerward 845.5 – 854.5 Retention polder* 10 station Total for Lower Rhine 65.4 Total volume of the measures taken into account in the model approx.