FLOOD PROPAGATION UNCERTAINTY

FLOOD PROPAGATIONFLOOD PROPAGATIONUNCERTAINTYUNCERTAINTY

J. Mulet – F. AlcrudoArea de Mecánica de Fluidos, CPS-Universidad de Zaragoza

BASIC UNCERTAINTY APPROACH

• Run models on the three (upper, mid, lower) hydrographs provided in breach analysis

• Fixed bathymetry (1982)– Added comparison with 1998 bathymetry

• Different models/modellers

UNCERTAINTY SIMULATIONS.UNCERTAINTY SIMULATIONS.

SIMULATION NUMBER OF CELLS CITY MODEL

CEMAGREF COURSE MESH 2611 VERTICAL WALLS*

UCL R-7 60911 VERTICAL WALLS

UDZ-1 (Mulet) ~ 20000 VERTICAL WALLS

SIMULATION NUMBER OF CELLS CITY MODEL

UDZ-2 (Murillo) ~ 40000 BOTTOM ELEVATION

1982 BATHYMETRY

1998 BATHYMETRY

REQUESTED RESULTS:

- WATER DEPTH HISTORY AT GAUGE/POINTS LOCATIONS

- DISCHARGE HYDROGRAPH THROUGH SECTIONS

- WATER DEPTH ENVELOPE OF 0.5 m AND 2 m

DIFFERENCE BETWEEN BATHYMETRIES.DIFFERENCE BETWEEN BATHYMETRIES.

DIFFERENCE BETWEEN BATHYMETRIES.DIFFERENCE BETWEEN BATHYMETRIES.

EXPERIMENTAL SPIKE LIKE PEAK BETTER REPRODUCED

PLATEAU LIKE EMPTYING

NOT BIG DIFFERENCES IN WATER SURFACE ELEVATION BETWEEN BATHYMETRIES

UNCERTAINTY RESULTS. GAUGE 1.UNCERTAINTY RESULTS. GAUGE 1.

1982-1998 BATHYMETRY (4.77m)1982 MAX - MIN

DIFFERENCES ATTRIBUTABLE TO INTERPOLATION IN STEEP SLOPE AREA


1982-1998 BATHYMETRY (2.67m)1982 BATHYMETRY

GAUGE LOCATION PICTUREOLD CINEMA



GAUGE LOCATION PICTURECONDES DE ORGAZ STREET



GAUGE LOCATION PICTUREPROYECTO C STREET

- DIFFERENCES BETWEEN BATHYMETRIES STRESSED


1982-1998 BATHYMETRY (~0m)1982 BATHYMETRY

GAUGE LOCATION PICTUREOLD CITY HALL

- SPIKE LIKE PEAK BETTER REPRODUCED

- SIMILAR WATER ELEVATION FOR BOTH BATHYMETRIES



GAUGE LOCATION PICTURECLOCK´S SITE

RISE RATES ARE BETTER REPRODUCED WITH THE UPPER HYDROGRAPH



GAUGE LOCATION PICTUREJÚCAR STREET


1982-1998 BATHYMETRY (-1.12m)1982 BATHYMETRY

GAUGE LOCATION PICTUREVALENCIA STREET

IMPORTANT BATHYMETRY EFFECT

(EVEN IF DIFFERENCES IN BOTOTM ELEVATION AT GAUGE ARE SMALL)GAUGE LOCATION PICTURE

1 KM DOWNSTREAM TOUS DAM

UNCERTAINTY RESULTS. POINT A.UNCERTAINTY RESULTS. POINT A.

1982-1998 BATHYMETRY (-1.17m)1982 BATHYMETRY

UNCERTAINTY RESULTS. SECTION 1.UNCERTAINTY RESULTS. SECTION 1.

1982-1998 BATHYMETRY1982 BATHYMETRY

GAUGE LOCATION PICTURE1 KM DOWNSTREAM TOUS DAM

IMPORTANT DISCHARGE DIFFERENCES BETWEEN THE 2 BATHYMETRIES

UNCERTAINTY RESULTS. POINT B.UNCERTAINTY RESULTS. POINT B.


GAUGE LOCATION PICTUREAZUD

STRONG SCATTERING BETWEEN MODELS/MODELERS




UNCERTAINTY RESULTS. POINT C.UNCERTAINTY RESULTS. POINT C.






UNCERTAINTY RESULTS. POINT D.UNCERTAINTY RESULTS. POINT D.


GAUGE LOCATION PICTUREBEFORE HILL UPSTREAM SUMACÁRCEL

NEARLY NO DISPERSION AT ALL

UNCERTAINTY RESULTS. POINT E.UNCERTAINTY RESULTS. POINT E.


GAUGE LOCATION PICTURERIVER BANK OPPOSITE SUMACÁRCEL

NEARLY NO DISPERSION IN WATER ELEVATION BETWEEN BATHYMETRIES

UNCERTAINTY RESULTS. POINT F.UNCERTAINTY RESULTS. POINT F.


GAUGE LOCATION PICTUREDOWNSTREAM SUMACÁRCEL

NEARLY NO DISPERSION IN WATER ELEVATION BETWEEN BATHYMETRIES

ADDED RUNS

HID NUMBER OF CELLS

VALLEY FRICTION ZONES FRICTION CITY MODEL

UPPER- U ~ 20000 0.045 0.1 NONE

BASIC ~ 20000 0.025 0.1 VERTICAL WALLS

LOW-L ~ 20000 0.025 0.025 NONE

1982 BATHYMETRY

UNCERTAINTY 0.5m ISOLINES.UNCERTAINTY 0.5m ISOLINES.

UDZ-1 UPPER

UDZ-1 LOWER

CESI


UDZ-1 UPPER

UDZ-1 LOWER

CESI


UDZ-1 UPPERUDZ-1 LOWER

CESI

UNCERTAINTY 2m ISOLINES.UNCERTAINTY 2m ISOLINES.

UDZ-1 UPPERUDZ-1 LOWER

CESI

UNCERTAINTY 2m ISOLINES.UNCERTAINTY 2m ISOLINES.

CEM UPPER

UDZ-1 UPPER

CESI

NO SIGNIFICANT EFFECT INFLUENCE OF ADDED UNCERTAINTY EFFECTS


UNCERTAINTY RESULTS. POINT A.UNCERTAINTY RESULTS. POINT A.

UDZ-1BETWEEN MODELLERS




UNCERTAINTY RESULTS. POINT B.UNCERTAINTY RESULTS. POINT B.



EXTRA FRICTION EFFECTS ARE INCREASED DOWNSTREAM




UNCERTAINTY RESULTS. POINT C.UNCERTAINTY RESULTS. POINT C.



FURTHER INCREASE DOWNSTREAM MAINLY DUE TO THE FRICTION ZONING (NO SIGNIFICANT EFFECT OF BASELINE FRICTION)




- SAME WATER FLOW RATE FOR BOTH BATHYMETRIES THROUGH SECTION 3 DESPITE THE DIFFERENCE IN WATER LEVEL

- SAME PEAK AS IN THE OUTFLOW TOUS DAM HYDROGRAPH

UNCERTAINTY RESULTS. POINT D.UNCERTAINTY RESULTS. POINT D.


GAUGE LOCATION PICTUREBEFORE HILL UPSTREAM SUMACÁRCEL

UNCERTAINTY RESULTS. POINT E.UNCERTAINTY RESULTS. POINT E.


GAUGE LOCATION PICTURERIVER BANK OPPOSITE SUMACÁRCEL

UNCERTAINTY RESULTS. POINT F.UNCERTAINTY RESULTS. POINT F.


GAUGE LOCATION PICTUREDOWNSTREAM SUMACÁRCEL

NO FURTHER INCREASE IN THE EFFECT

CONCLUSIONS (Preliminary)

• Uncertainty sources considered (and proved relevant)– Model / Modeler– Bathymetry– Friction levels

• Specifically friction distribution/zoning• Baseline friction level not significant

• Uncertainty in urban area– Overall 2m (either water depth / water elevation)

• Uncertainty in valley– Considerably higher with strong differences– No clear indications as to comparative influence of considered

parameters/effects

Documents

FLOOD PROPAGATION UNCERTAINTY