How to cope with floods - the Bavarian experience Prof. Dr. Peter - - PowerPoint PPT Presentation

▶
how to cope with floods the bavarian
SMART_READER_LITE
LIVE PREVIEW

How to cope with floods - the Bavarian experience Prof. Dr. Peter - - PowerPoint PPT Presentation

Jun 19, 2023 123 likes •550 views

How to cope with floods - the Bavarian experience Prof. Dr. Peter Rutschmann S. Giehl, D. Skublics, M.- D. Bui, M. Reisenbchler Technical University Munich (TUM) Department of Civil, Geo and Environmental Engineering Chair of Hydraulic and

slide-1
SLIDE 1
  • Prof. Dr. Peter Rutschmann
  • S. Giehl, D. Skublics, M.-D. Bui, M. Reisenbüchler

Technical University Munich (TUM) Department of Civil, Geo and Environmental Engineering Chair of Hydraulic and Water Resources Management Athens, 31 October 2018

How to cope with floods - the Bavarian experience

slide-2
SLIDE 2
  • 1. Flood mitigation at large rivers in Bavaria
  • 2. Are floods pure water events
  • 3. Flash floods in Bavaria/Greece
  • 4. Flash flood risk management concept in Bavaria
  • 5. The steps to flash flood risk minimization
  • 6. Conclusions

2

Contents

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-3
SLIDE 3

3

Flood retention at Danube and Inn river

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-4
SLIDE 4

4

Flood retention at Danube and Inn river

dQoptimal Qmax,Ist [m³/s] Qmax,Plan [m³/s] Abfluss Zeit VFlutpolder

Schematic sketch of polder operation One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

Floodpolder (retention space) Outlet Inlet Separation dike

Floodpolder: components and functioning Flood Dialogue Bavaria: https://www.hochwasserdialog.bayern.de/technischer_schutz/flutpolder/index.htm

slide-5
SLIDE 5

5

Flood retention at Danube and Inn river

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-6
SLIDE 6

Effect of flood polders on relative wave peak reduction and inhabitants along the river

6

Flood retention at Danube river

2588 2538 2488 2438 2388 2338 2288 2238 500 1000 1500 2000 2500 3000 20000 40000 60000 80000 100000 120000 50 100 150 200 250 300 350 betroffene Einwohner pro Flusskilometer [1/km] betroffene Einwohner [-] Flusskilometer [km] betroffene Einwohner pro Flusskilometer Summe der betroffenen Einwohner mögliche Flutpolderstandorte

Neu-Ulm Donauwörth Neuburg Vohburg/Neustadt Regensburg Straubing Deggendorf Passau Ingolstadt Kelheim

Hochwasserschutzkonzept Straubing-Vilshofen

Number of inhabitants affected by floods along the Danube river (annuality of flood event > 100) One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-7
SLIDE 7

7

Floods in the historical/present virtual Danube

until 1900 1950 today

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-8
SLIDE 8

8

Flooded areas from a 100 year flood with a medium hydrograph. Nowadays dams and dikes are overflown during the peak discharge and very efficiently attenuate the event.

Flooding in the historical/present Danube

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-9
SLIDE 9

9

Floods as pure water events?

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-10
SLIDE 10

Since one century Freilassing has never been flooded until 2013.

10

2013 Flood Freilassing (River Saalach)

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-11
SLIDE 11

Equivalent flow discharges for river bed topographies of 2005 and 2013

11

Flooding for differing bed topography

Richard Heinz, WWA-TS. river bed 2013 Richard Heinz, WWA-TS

river bed 2005

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-12
SLIDE 12

12

HPC and hydromorphological modelling

Increasing the complexity and the computational effort

SYSIPHE

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-13
SLIDE 13

13

HPC and hydromorphological modelling

Increasing the complexity and the computational effort Leibnitz-Computational-Center LRZ Garching SuperMUC and SuperMUC2:

  • 2012: #4 of world TOP 500
  • 2016: #36 of world TOP 500
  • In total 241000 Cores at SuperMUC

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-14
SLIDE 14

14

Before and after Source: BayernAtlas and googlemaps

Flash Flood Simbach

http://www.br.de/nachrichten/dokthema- toedliches-wasser-hochwasser-gruende-100.html

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece Picture (left): Courtesy of the Bavarian State Ministry of the Envorronment and Consumer Protection,

slide-15
SLIDE 15

15

Urban development

Flash Flood Simbach

Simbach Bayernatlas 1817-1841 Simbach Bayernatlas 1925 Simbach Bayernatlas 1965 Simbach Bayernatlas 2005 One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-16
SLIDE 16

16

Before and after

Flash Flood Simbach

Hübl, J. et al. 2017: IAN REPORT 180, Ereignisdokumentation und Ereignisanalyse Rottal-Inn 2016, Band 1: Ereignisdokumentation. University of Natural Resources and Life Sciences, Vienna, 2017, page 75 ff.

https://www.baunat.boku.ac.at/fileadmin/data/H03000/H87000/ H87100/DAN_IAN_Reports/Rep180_Band_1_mit_Anhang.pdf

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-17
SLIDE 17

17

Damage and bottle necks

Flash Flood Attica (Mandra)

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-18
SLIDE 18

18

Damage and bottle necks

Flash Flood Attica (Mandra)

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-19
SLIDE 19

19

Source: „Integrale Konzepte zum kommunalen Sturzflut-Risikomanagement“, Infoblatt zum Sonderprogramm nach Nr. 2.4 RZWas 2016, Bavarian Statesministry for the Environment, 2016, 24 pages.

Bavarian Flashflood Strategy

  • 1. Screening / status analysis
  • 2. Hazard analysis
  • 3. Hazard and risk assessment
  • 4. Conceptual development of (protection) measures
  • 5. Integral strategy for flash flood risk management on municipal level

Implementation of measures

“What might happen and where?” “What should not happen where and what could be allowed where?” “What measures could be taken?” One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-20
SLIDE 20
  • Flashfloods are local phenomena and very difficult to spatially predict,
  • they are short but very intense events,
  • they are everything else than pure water events,
  • their physical processes are very complicated, cascading and therefore:
  • The unbelievable can happen!

Thus one has to verify:

  • Where are flashfloods likely to happen
  • What consequences can they have
  • What can immediately be done on a very local and municipal level

(identification of bottlenecks)

  • What protection measures could and should be tacken in a next step
  • How can information and early warning of the public be organized

20

Flashflood properties

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-21
SLIDE 21

Possible method:

  • Setup a large scale but coarse terrain model
  • Charge it with havy rain scenarios
  • Do a simplified rainfall-runoff hydraulic computation
  • Concentrate on high velocities, high water depths and high bottom

shears

  • Check whether such regions interfere with civilization
  • Thus
  • Endangered regions/municipalities can better be identified
  • Possible risk must be communicated to the municipalities
  • A process has to be initiated at the municipal level to protect the

population

21

Where can flashfloods happen?

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-22
SLIDE 22

22

  • Topographic date from remote sensing or airborne laser scanning
  • Vegetation data also available from remote sensing
  • Simpliefied flow computation is possible
  • Critical spots from flows can be identified

Topography and vegetation is easily available

Gabriel, 2009

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

Gabriel, 2009

slide-23
SLIDE 23

Possible processes:

  • Heavy floods can occur which river cross sections cannot contain. We

can probably cope with this idea.

  • The rain and the flow will transport high sediment and debris loads. In

parts heavy erosion but also heavy deposition of material can occur. We understand this, but we have difficulties to figure out the consequences.

  • During flash floods the infrastructure can completely be modified to other

purpose than intended and fullfilling new functions which were out of their design. We have to be innovative to find worst case scenarios. Theoretically we can model such processes but the models will mostly show only the processes we anticipate. Anticipation is therefore important not only for an eventual modelling attempt but also for site visits and protection measures on a municipal level!

23

What can happen during a flashflood?

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-24
SLIDE 24

24

Radar rainfall observation

Hübl, J. et al. 2017: IAN REPORT 180, Ereignisdokumentation und Ereignisanalyse Rottal-Inn 2016, Band 1: Ereignisdokumentation. Universität für Bodenkultur Wien, 2017. One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-25
SLIDE 25

Importance:

  • Radar observation is important to predict spatial distribution of rain.

Meteo models are helpful to predict future developments.

  • From radar observation the local and heavy precipitation centers can be

identified and their propagation can be estimated. This is valuable information for early warning systems.

  • If no radar is present, mobile phones can serve to determine the rain

intensity.

  • In case no super computers are available fast predictions can be

achieved with ANNs.

25

Radar observation and rain forecasts

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-26
SLIDE 26

26

Fast computation/prediction

SuperMUC High Performance Umweltsimulation

Virtueller Wasser Raum Bayern

Fernerkundungs- Daten

LfL-Messnetze DWD CSC-2.0 LfU-Messnetze

Ressortdaten

Verwaltung Wirtschaft

Management- Daten Hydrologischen Landoberflächenprozesse Erosion, Stofftransport Aquatische Biodiversität Hydraulische Gerinneprozesse

  • Wasserwirt. Strukturen

Management Visualisierung Szenarien Datenanalyse Ensembles Modelle und Simulation Modelle und Simulation Daten- Analyse

Szenarien-Raum

(z.B. Katastrophen- Simulation)

Informations-Raum

(Verbreitung, Partizipation)

Verhandlungs-Raum

(Konfliktlösung)

Trainings-Raum

(Weiterbildung, Qualifikation)

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-27
SLIDE 27

27

Fast computation/prediction

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-28
SLIDE 28

Research Consortium Funded by

VieWBay

Hydro-BITS (LRZ) HYDRODYNAMICS + MORPHOLOGY (TUM) HYDROLOGY (LMU)

Fine Discretization of Bavaria TELEMAC goes HPC TELEMAC - Bavary

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-29
SLIDE 29

VieWBay - Vision

slide-30
SLIDE 30
  • Unlike with river floods, flashfloods are short events, difficult

to predict in space and therefore early warning has to take place prior of flooding.

  • Computations (for complex situations) or expert judge site

seeings must be done before events.

  • Necessary protection measures must be initiated dependent
  • n this analysis.
  • An early warning, dependent on meteorological information

must, must happen and initiate a flood management plan.

  • Information and training of endangered municipalities has to

be performed.

30

Conclusions

One day conference on Climate Change and Natural Desaster, 31 October 2018, Athens, Greece

slide-31
SLIDE 31

31

Thanks for your attention!

Fishfriendly-hydropower (EU-H2020 project coordinated by TUM): http://www.FIThydro.eu

31 Markus Reisenbüchler, M.Sc. (TUM) | Symposium | Potsdam, 06-08.March.2017

slide-32
SLIDE 32
slide-33
SLIDE 33
  • Transport capacity at the ramp
  • Sedimentation and erosion of bed-load on and

around the ramp

  • Effects on the discharge capacity of the river

Saalach

33

2005/06 a ramp has been constructed at River Saalach at river-km 4,6. Morpho-dynamic processes at the ramp have been investigated to study their effect on the 2013 flooding

Telemac for morpho-dynamic computations

  • Prof. Dr. P. Rutschmann (TUM), Symposium on Global Change Effects, Potsdam, 06-08 March.2017
slide-34
SLIDE 34

34

Steps of performing numerical computations with morpho-dynamic models. Details of the Freilassing case are presented by M. Reisenbüchler (TUM), session 4

Methodology

  • Prof. Dr. P. Rutschmann (TUM), Symposium on Global Change Effects, Potsdam, 06-08 March.2017
slide-35
SLIDE 35

35

Sediment transport for various scenarios (2013)

10 20 30 40 50 60 70 80 90 100 5,4 4,8 4,2 3,6 3 2,8 2,6 Geschiebemenge [m³] Χιλιάδες Querprofil [Fkm]

S0 S1 S2 S3 S4 P1997

Detailed results presented by M. Reisenbüchler (TUM), S4

  • Prof. Dr. P. Rutschmann (TUM), Symposium on Global Change Effects, Potsdam, 06-08 March.2017
slide-36
SLIDE 36

36

ANN methods for sediment transport in rivers

An artificial neural network is a computational model based on the structure and functions of biological neural networks (e.g. the human brain). It can be used:

  • to derive meaning from complicated or

imprecise data,

  • to extract patterns and detect trends,
  • to provide projections given new

situations.

  • Prof. Dr. P. Rutschmann (TUM), Symposium on Global Change Effects, Potsdam, 06-08 March.2017
slide-37
SLIDE 37

37

New hydro-morphological modeling system

numerical approach ANN flow/sediment ANN for sediment

  • Prof. Dr. P. Rutschmann (TUM), Symposium on Global Change Effects, Potsdam, 06-08 March.2017
slide-38
SLIDE 38

38

Future computational resources

Modell purpose:

  • Simulation of long term developments
  • Reservoir management
  • Evalation of river construction measures

Modell scales and concept:

  • 1. Spatial
  • Nowadays we compute river reaches with a few kilometers, in the future we

want to compute reservoirs and complete river systems with many kilometers

  • 2. Temporal
  • Nowasays we compute flood scenarios of several days in the future we want to

compute developments over years Future developments – years

  • 3. Conceptual
  • Nowadays wie simplify as much as possible, in the future we want an accuracy

as high as possible → Long term simulation with a high spatial resolution and highest accuracy!

  • Prof. Dr. P. Rutschmann (TUM), Symposium on Global Change Effects, Potsdam, 06-08 March.2017
slide-39
SLIDE 39
  • We should consider sediments for all flood considerations
  • For mountainous floods and flash floods sediments are a key issue
  • In order to do this we must go new ways. We should stick as close as possible to

the physics while saving CPU time with new algorithms

  • Climate change will have an effect on floods but possibly even more on sediment
  • transport. This may have dramatic effects on spawning of aquatic populations.
  • In the future we should therefore put more weight on managing our environment

to compensate for effects of climate change

  • …and we should consider such effects when we plan our today mitigation

measures, e.g. the present river restauration projects.

39

  • Prof. Dr. P. Rutschmann (TUM), Symposium on Global Change Effects, Potsdam, 06-08 March.2017

Conclusions

slide-40
SLIDE 40

40 Stefan Giehl | floods

Before and after Source: BayernAtlas and googlemaps

Flash Flood Simbach

slide-41
SLIDE 41

41

Flood damping for a medium hydrograph is more efficient in the present then in the past Danube

Retention in the historical/present Danube

  • Prof. Dr. P. Rutschmann (TUM), Symposium on Global Change Effects, Potsdam, 06-08 March.2017