Integrate, Consolidateand Disseminate

European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Efficiency of non-structural flood mitigation measures:

“room for the river” and “retaining water in the landscape”

Flood Plain Hydraulic ModelCase Study: Poyo Creek

By:

Enrique Ortiz - HidroGaia, S.L. Water and Environment Technology

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Our contribution to this project

WP1: Generating scenarios WP2: Basin Hydrology

WP3: Flood prone areaanalysis

WP4: Flood impact andnon-structuralmeasures evaluation

T1.1. Land -uses

T1.2. Flood retention

T1.3. Hydrological inputs

T2.1. Model parametersestimation

T2.2. Simulations

T2.3. Statistical analysis

T3.1. DEM and hydrauliccharacteristics

estimation

T3.2. Hydraulicsimulations

T3.3. Hazard mapping

T4.1. Vulnerability

T4.2. Flood impact

T4.3. Non-structuralmeasures evaluation

WP3: Flood pronearea analysis

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

WP3: Flood prone area analysis

• DEM and hydraulic characteristics estimation– Sensitivity to DEM resolution

• Hydraulic simulations with appropiate model:– SOBEK-Rural (WL| Delft Hydraulics) 1D/2D– Interpolation of previous simulations

• Flood hazard mapping

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Hydraulic modelling area

188 Km2

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

• Sources– Aerial Photogrammetry

• Two Fligths• Scale of restitution 1:2,000

– DEM 10 meter resolution• Merging sources

– Coupling three sources

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

Two Sources of aerial Photogrammetry

Final Product: Two DEM 5 meter resolution

DEM lake Albufera

DEM flood plain

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

Intersection area and elevation differences of two DEMs

± 10 cm

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

Merging two DEMs

5 m resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

Two missing areasof altimetric data

But there is RegionalDEM with 10 meter resolution property

of regional Government

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

First task is resample our DEM of5 meter resolution to 10 meter resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

Second task is merge resample DEM with Regional DEM

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

Add buildings to the DEM with 10 meter resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

Final DEM with 10 meter resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Digital Elevation Model

Final DEM with 10 meter resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Scale Analysis of Digital Elevation Model

We would like to study different scales for flood plain hydraulicModel (Unidimensional topology is obtained from the best Carthography resolution, 5 X 5 meters in all cases)

We choose five scales:

• 5 meters DEM resolution• 10 meters DEM resolution• 20 meters DEM resolution• 30 meters DEM resolution• 50 meters DEM resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Scale Analysis of Digital Elevation Model

5 meter DEM resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Scale Analysis of Digital Elevation Model

10 meter DEM resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Scale Analysis of Digital Elevation Model

20 meter DEM resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Scale Analysis of Digital Elevation Model

30 meter DEM resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Scale Analysis of Digital Elevation Model

50 meter DEM resolution

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

SOBEK RURAL WL|Delft Hydraulics

• SOBEK is a powerful 1D and 2D instrument for flood forecasting, drainage systems, irrigation systems, sewer overflow , ground-waterlevel control, river morphology, salt intrusion and water quality.

• The system is designed to deal with any kind of flows, sub- orsupercritical including hydraulic jumps or floodwave bores.

• The computational domain is splitted into a one-dimensional network, with general volumes of arbitrary shapes, and a two-dimensional part with rectangular computational cells.

• The equations to be solved are based upon the momentum balance and the conservation of mass. Saint Venant equations.

0y

)vh(x

)uh(t

=∂

∂+

∂∂

+∂ζ∂

02 =++∂∂

+∂∂

+∂∂

+∂∂

vavhC

Vvg

yg

yv

vxv

utv ζ

02 =++∂∂

+∂∂

+∂∂

+∂∂

uauhC

Vug

xg

yu

vxu

utu ζ

ConservationMomentum

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Implicit coupling of 1D and 2D schematisations can be based uponthe concept that both are to be defined on separate computational

layers, similar to the concept of the storage of spatial data ondifferent layers in a GIS.The 2D layer describes, on the basis of a

rectangular computational grid, flow over DTM-defined topographiesadjusted for objects blocking flow in floodplains, such as dikes andnatural levees. All sub-grid conveyance objects, such as channels,

including remnants of dead river branches and similar local depressions, and all kinds of hydraulic structures are described on

the 1D schematisation layer. Subsequently,1D and 2D schematisations will be linked to each other via water level

compatibility at selected computational nodes

SOBEK RURAL WL|Delft Hydraulics

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Both computational layers havefinite difference formulations forvolume and momentum balance equations, based uponastaggered grid approach.Thewater level compatibility betweenboth layers is obtained by addingfluxes from the1D and2Dschematisations throughsubstitution into a sharedcontinuity equation at the commongrid points where water levels are defined. Referring to Frank et al. (2001),the shared continuityequation is formulated as follows:

( ) ( )( ) ( )( ) ( )∑=

=−− =+−∆+−∆+

jiLji

ki

Kl

Kllnjijijiji

ji Qvhvhxuhuhydt

dV,

,

1,

0)()(

1,,,1,, ς

SOBEK RURAL WL|Delft Hydraulics

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

SOBEK 1D/2D

1. Cartography/orthophoto

2. Digital Elevation Model

3. 1D River Network

4. Overland Flood Simulation

5. Results

MassanasaPaiporta

Pis

ta d

e S

illa

Catarroja

SUPERFICIE MAX. AGUA

MARGEN Y FONDO

MassanasaPaiporta

Pis

ta d

e S

illa

Catarroja

SUPERFICIE MAX. AGUA

MARGEN Y FONDO

SOBEK RURAL WL|Delft Hydraulics

Integrate, Consolidateand Disseminate

European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

1D Computational Domain

383 Cross SectionsObtained from TIN

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ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

2D Computational Domain

493272 Cells

30 x 30 meter

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ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

1D/2D Computational Domain

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ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Roughness spatially distributed

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ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Boundary Conditions

1

2

3

4

11

22

33

44

1

2

3

4

11

22

33

44

436885071765094.364 Horteta Creek

4372350710850190.133 Poyo Creek at motorway A7

437155071075059.682 Gallego Creek at motorway A7

437405071155033.261 Pozalet Creek at motorway A7

UTM-YUTM-XBasin Area(km²)Hydrograh (TETIS Model)

Upstream

Downstream

Water Level in Albufera Lake

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Preliminary Results

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Preliminary Results

Integrate, Consolidateand Disseminate

European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Preliminary Results

Integrate, Consolidateand Disseminate

European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Preliminary Results

Integrate, Consolidateand Disseminate

European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Preliminary Results

Integrate, Consolidateand Disseminate

European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Preliminary Results (Flood Hazard Mapping)

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European Flood RiskManagement Research

ERA-NET CRUE Funding Initiative Efficiency of non-structural flood mitigation measures: "room for the river" and "retaining water in the landscape "

Preliminary Results

Examples the hydraulic simulations with SOBEK

• Complete Model 1D/2D 30 meters DEM resolution• Little area into complete Model 2D 5 meters DEM resolution