Hydra-Models A way to assess the influence of climate change and - PowerPoint PPT Presentation

Hydra-Models A way to assess the influence of climate change and river programs on future dike heights and the probability of dike failure. Robert Slomp 18 april 2005

Robert Slomp 2 18 april 2005 Contents Hydra-models Flood defense characteristics per area Room for the River Meuse Works Changes is surplus dike height 2001-2015 Changes in probability of failure, an example

Robert Slomp 3 18 april 2005 Probabilistic versus deterministic approach Probabilistic Deterministic Infinite number of a design water level, combinations of water a design wind speed and levels, wind speed and wind direction wind direction

Robert Slomp 4 18 april 2005 What are Hydra-models? A method to weigh possible physical events (water levels and waves) Physical models Geographical water levels and waves Rijkswaterstaat information Data bases water levels and waves Statistics Hydra Dike information Hydra user Hydraulic load (water level or runup level at legal return period)

Robert Slomp 5 18 april 2005 Hydra’s * 1998 –1999 Hydra-M, for the IJssel lake area • 2001 Hydra-B for the Rhine and Meuse Estuaries extended in 2004 to the borders with Germany and Belgium • 2006 Hydra VIJ for the Vecht and IJssel delta area

Robert Slomp 6 Climate change and soil subsidence 18 april 2005

Robert Slomp 7 18 april 2005 Room for the River objective: to deminish the increase in design water levels increase in design waterlevels in m from 1996 to 2001 (effects on account of model issues and design discharges have been combined ) 520000 -0,45 510000 -0,35 - -0,40 500000 -0,25 - -0,30 490000 -0,15 - -0,20 480000 -0,05 - -0,10 470000 -0,00 km 460000 +0,05 - +0,10 450000 +0,15 - +0,20 440000 +0,25 - +0,30 430000 +0,35 - +0,40 420000 +0,45 - +0,50 RI 410000 +0,55 - +0,60 400000 60000 70000 80000 90000 100000 110000 120000 130000 140000 150000 160000 170000 180000 190000 200000 210000 220000 km

Robert Slomp 8 18 april 2005 Little space and more damage potential each year Arnhem, 2000 Arnhem, 1830

Robert Slomp 9 18 april 2005 Measures Setting back dikes 7 low w ater level high w ater level 3 5, 6 Lowering 8 of river flood plain 4 1 1 and flow 2 channel 1 low erin g of gr oy n es 5 locally settin g b ack dik es Raising dikes 2 deepening low flow channel 6 setting back d ik es on a large sc 3 removing h ydraulic ob stacles 7 detention reservoir 4 low erin g flood plains 8 reduction lateral inflow Construction Buildings of bypasses Room for the Rhine branches E000323c

Robert Slomp 10 18 april 2005 Meuse Works – mainly improvement of the 40 new dikes and lowering of the flow channel

Robert Slomp 11 18 april 2005 Climate change, the influence on dike heights 1) Extra storm surge and sea level rise: an effect of 60-70% in the lower Rhine and Meuse reaches The influence on design water levels of a 60 cm sea level rise location meters Bergse Maas km 231 0,10 Bergse Maas km 235 0,12 Bergse Maas km 240 0,16 Bergse Maas km 245 0,23 Bergse Maas km 246 0,25 Bergsche Maas 247 0,37 Bergsche Maas 251 0,50 Hollandsch Diep km 980 S 0,40 2) Higher design discharges, main branches and tributaries a 0,60 to 0,80 m increase from the main branches 3) 10% higher wind speeds and more westerly winds 10% increase?

Robert Slomp 12 18 april 2005 Flood retention on the Rhine 1000 m 3 /s flood retention is a drop of 30 -35 cm on the Waal in design water levels Probabilisticly this is only 20 – 25 cm Influence of a retention area 1000 m3/s on the design water levels, for different return periods influence (drop) in m 0,400 mean probabilisticly 1250 0,300 2000 0,200 4000 0,100 WAQUA 1250 till 950, Hydra-B till 980 0,000 900 920 940 960 980 1000 River km along the Waal

Robert Slomp 13 18 april 2005 Flood retention only takes a bite out of the flood wave flood wave with higher return period x year flood wave Intake level

Robert Slomp 14 18 april 2005 Dikes have been built in all sizes, forms and heights Rhine Branches 600 km dike , 6000 cross sections Meuse 200 km dike, 2000 cross sections All dikes are modeled as: a 1 in 3 outer slope the actual outer crest level the dike perpendicular line from GIS, filtered for 100 m sections

Robert Slomp 15 18 april 2005 Surplus dike heights before and after Room for the River

Robert Slomp 16 18 april 2005 Surplus dike heights before and after Meuse Works 1 Neglible flooding of upper reaches Km 3 to 150/170 ? 2 Perfect flooding of upper reaches Km 3 to 150/170

Probability of dike failure dike Robert Slomp 17 18 april 2005 ring 43 probability of dike failure, dike ring 43 scenario dike heights critical max probability overtopping discharge limit Rhine Actual 2001 current design 18 000 m 3 /s practice 1 l/s per m 1/600 Actual 2001 18 000 m 3 /s actual dikes 1 l/s per m 1/200 After RvdR current design 18 000 m 3 /s 2015 practice 1 l/s per m 1/1100 After RvdR 18 000 m 3 /s 2015 actual dikes 1 l/s per m 1/1200 After RvdR 50 l/s per m 18 000 m 3 /s 2015 actual dikes 1/5000 After RvdR 2015 actual dikes 1 l/s per m 16000 m3/s 1/1400