Machland 2010 ( OÖN, 2010) Flood Risk Management in Austria Univ.Prof. Dipl.Ing. Dr.nat.techn. Christian Doppler Laboratory for Advanced Methods in River Monitoring, Modelling and Engineering Institut of Water Management, Hydrology and Hydraulic Engineering Department of Water, Atmosphere and Environment BOKU University of Natural Resources and Life Sciences, Vienna Muthgasse 107, A-1190 Wien helmut.habersack@boku.ac.at Tel.: +43 1 3189900 101 Fax.: +43 1 3189900 149 1 Contents Introduction Risk Circle Organisation of integrated flood risk management (IFRM) in Austria New methods in IFRM Conclusions 2 1
(Habersack et al., 2004) Introduction Recent flood events in Austria 2002 2005 2013 3 Risk Circle 4 2
( Hochwasserschutz in Österreich, BMLFUW, 2006) Organisation of IFRM in Austria 5 Bypass-Channel ( Donau-Insel in Vienna) Danube Island Vienna Technical information: Water amount: 14.000 m 3 /s Discharge Danube: 8.800 m 3 /s Discharge New Danube: 5.200 m 3 /s Length of Danube Island: 21,1 km Width of new Danube: rd. 200 m Width of Danube Island: 70-210 m Flood-free area of Danube Island: 390 ha ( MyFriend) Intake structure Constructional information: Construction period: 1972 1998 Excavation New Danube: 28,2 Mio. m 3 Aggradation Danube Island: 23,8 Mio m 3 Stones for bed protection: 1,3 Mio.m 3 Stones for bank protection : 0,5 Mio m 3 Intake structure: 5 weir fields at 24 m width ( Stadt Wien) 6 3
Copa Kagrana ( MeinBezirk) Donaukanal ( Kurier) Floridsdorf ( Wikimedia) Sunken City ( ORF) Bypass channel / Danube Island Vienna Flood 2013 7 New methods in IFRM Floodplain Evaluation Matrix (FEM) Minimum River Morphological Space Demand (FMRB min ) Spatially Variable Vegetation Management (VEMA flood ) Mobile Flood Protection 8 4
Q [m³/s] Floodplain Evaluation Matrix (FEM-Method) 12000 10000 8000 6000 4000 2000 HQ 08-2002 Danube 0 2002 07/08 09/08 11/08 13/08 15/08 17/08 19/08 9 Floodplain Evaluation Matrix (FEM-Method) Example Austrian Danube Hydrological Assessment Reach 1 Reach 2 Reach 3 ΔQ/km Eferdinger Becken -11,32 m 3 /s Linzer Feld -5,93 m 3 /s Machland -22,38 m 3 /s Ybbser Schild -0,82 m 3 /s Hinterland Altenwörth -1,97 m 3 /s Tullner Feld -22,78 m 3 /s NP Donau- Auen -2,05 m 3 /s 3. 2. 1. 10 5
Breitenänderungsverhältnis nach/vor Hochwasser [-] Minimum River Morphological Space Demand 7 6 Specific stream power Minimum river morphological space demand (3-7 times the width) 5 4 3 2 R 2 = 0.7303 Bregenzerach Rosanna Trisanna Alfenz Lech 1 0 0 2000 4000 6000 8000 Gemittelte Strömungsenergie [W/m²] Krapesch, Hauer, Habersack, 2011, J. Natural Hazards and FloodRisk II 11 Minimum River Morphological Space Demand Establishment of a minimal safety strip along the river which is 1 to 3 times the width of the river on each river bank with absolute construction ban 12 6
(Schulz, 2010) water level differences [in ] to vegetation-free (FloodRisk II, 2009) Spatially Variable Vegetation Management Division of river stretches in: Sensitive Sections Transition Sections Vegetation-Dynamic Sections Vegetationmanagement at the Bregenzerach Sections: Sensitive Section Transition Section Vegetation-Dynamic Section 13 Mobile Flood Protection Video: Grein / Strudengau, Flood 2013 14 7
(BMLFUW, 2015) EU Floods Directive Hazard Maps: Flood extent, flow depths, flow velocities Risk Maps: Number of affected persons, economic activity, other useful information (www.wisa.at) 15 EU Floods Directive Flood Risk Management Plan: 22 Measure Types EVENT M19: Catastrophe Plans PREPARATION AFTER-CARE M01: Hazard Zone Maps AWARENESS PREVENTION M16: Raising Public Awareness M07: Restoration of Floodplains PROTECTION M12: River Maintenance Works M09: Object Protection Measures 16 8
DREAM Danube River REsearch And Management 17 Conclusions Integrated flood risk management (IFRM) must focus on prevention before coping during and rebuilding after the flood event according to the risk circle. Non-structural (non-technical) measures like Floodplain Preservation / Restoration Minimum River Morphological Space Demand Spatially Variable Vegetation Management Catastrophe Management Plans, etc. will further gain in importance. Therefore, these measures should be integral part of the Flood Risk Management Plans according to the EU Floods Directive. 18 9