Czech Republic 2007/60/EC Methodology & Results of the Flood Risk Mapping Budapest, 16.11.2009 V4 on Flood Protection Ing. Vaclav Jirasek Ing. Petr Brezina
Present situation overview Legislation status Methodology International co-operation
Basic Data of the CR CR area of 78 864 km2, over 10 mil. inhabitants more than 76 000 km of streams from which 9 252 km belong to significant rivers Q100 possible flood risk affects 3,5% of all inhabitants flood risk areas is specified in 67% of significant rivers for return period Q5, Q20, Q100 + active zones delineation
Flooded Areas Specification
Map Technical Bases Ortho-photo maps (ZABAGED ) 1:10 000
Terrain Information Field measurement river & valley profiles Aerial Photogrametry DTM Laser Scan DTM just started (0,3 m 2012; 0,18 m 2014; total 2015) Historical flood marks > systematically after 1997 flood
Flood Risk Assessment 2000/60/EC Integrated River Basin Management River Basins -> > rivers / water bodies River Basin Management Plans Significant Water Management Issues Public Participation Programme of Measures - Financing
River Basin Management Plans
Contents of RBMP 0 - Introduction A Description of River basin B Water use and its impacts on water C Status of water bodies D Flood Protection and water regime in countryside E Program of measures influence on water bodies status F Economy Analyses
Legislation status 2007/60/EC Directive transposition Report 26.11.2009 Amendment of Water Act is still in the Government Competent Authorities same as for WFD 2000/60/EC MoE, MoA, 14 Regional Authorities that validate RBMP Preliminary flood risk assessment just finished Flood hazard and Flood risk mapping project is prepared + funding through grant program of MoE
Metodology A - Preliminary Flood Risk Assessment (PFRA) B - Flood hazard and Flood risk mapping (FRM) MoE WG for 2007/60/EC Directive implementation 2008 WRI Methodology for flood risk and flood damage specification 2008 (karel_drbal@vuv.cz) Methodology for Pluvial floods is prepared based on terrain morphology & run-off evaluation
A - PFRA Cadastral areas with Communities where: >25 inhabit./year or >70 mil. CZK damage/year is affected with flooding (loss cumulative function)
A - PFRA Localities connection into coherent river stretches In the Czech Republic aprox.2,5 thous. km Limits: > 25 ihabitants/year > 70 mil. CZK /year dangerous substances (industrial sources) cultural relicts
B- Flood Hazard Maps Flood extend Limits: Q5,Q20,Q100 + Q500 Zabaged +development plans Depth Velocity
B- Flood Risk Maps Matrix of flood risk IP = Intensity of Flooding IP = 0 0,3 + 1,35.h 0,3 + 1,35.h.v h = 0 h > 0, v < 1m/s v > 1m/s h dept of flood water v velocity of flood water
Procedure of Matrix of Risk Grid depths h [m] Input data IP = Intensity of flooding - IP 0 0,3 + 1,35.h h = 0 h > 0, v < 1m/s 0,3 + 1,35.h.v v > 1m/s Grid water flow velocity v [m/s] Grid intensity of flooding IP
Interpretation of Results Danger H > 0,1 or IP > 3 0,01 < H < 0,1 Category of Danger (4) High (3) Medium Recommendation Do neither new nor extend recent build-up areas, where can people or animal live. For recent build-up areas suggest such flood protection, which will reduce risk to acceptable level. Development is possible with some restrictions resulted from detailed analysis of potential flood hazard. Build-up of sensitive objects (e.g. hospitals, schools, fire station etc.) is unsuitable there. It is not recommended to extend recent build-up area. H < 0,01 (2) Low New development is possible. Estate owners have to be informed about potential flood hazard. Sensitive objects have to be protected against flood. P > 0,0033 (N-yr > 300) (1) Residual Flood protection is solved by long-term planning of land use zoning focused on especially sensitive objects (health care institution, historical objects etc.)
Flood Risk Maps review of present and future land use restriction of some activities in areas with higher level of flood threat use: process of land use planning, proposal of flood protection measures
International Co-operation A European Commision, WG F => reporting B / International Commisions (Elbe, Oder, Danube) WFD + FRMP C International Projects Label => FRM, FRMP D V 4 Co-operation => information exchange / research /??? - run-off change as result of coutryside management/practice change - peak discharge change due to the retention capacities (CHMI) - multicriterial floodplain risk assessment - estimation of indirect losses (social impacts, loss of markets) - more comprehensive uncertainty analysis in risk management - the influence of climate changes