International Roundtable on Protection and Sustainable Use of Transboundary Waters in Southeastern Europe, Zagreb, 15-16 Dec 2011

THEMATIC BLOCK 1- Emerging Challenges, Extreme phenomena-Floods

Dr Marina Babić MladenovićINSTITUTE “JAROSLAV ČERNI” - BELGRADE

A few cycles of intensive snow and intervals with unusually high airunusually high air temperatures

Water equivalent of snowabove average valuesabove average values

Coincidence of flood on the Danube and Tisza river, caused th hi h t t l lthe highest water levels ever recorded

Example of 2006 FloodExample of 2006 Flood

Example of 2006 FloodExample of 2006 Flood

Danube downstream of V. 15000

16000 > Q100

Danube between Sava and V. Morava

Morava

12000

13000

14000

9000

10000

11000

m3 /s

)

Danube between Drava and Tisa

6000

7000

8000

Dis

char

ge (

m < Q100

Sava river

3000

4000

5000

D

Q

∼ Q5

Tisa river

Velika Morava riverTamis river

0

1000

2000∼ Q100

23 25 27 29 31 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 2 4 6 8 10 12 14 16 18 20 22

April MayMarch

Successful flood defence, very expensive 10 M €240 000 ha flooded unprotected zones (between levees) and240 000 ha flooded – unprotected zones (between levees) and arrable land flooded by excessive inland waters - damage 30 M €State of emergency in 10 municipalities along the Danube and Tisa

Transboundary cooperation◦ Good cooperation between the HMS Serbia and HMS of other◦ Good cooperation between the HMS Serbia and HMS of other

DRB countries – hydrological data and forecasts◦ Flood release through the Iron Gate 1 and 2 dams was strictly

according to RO-RS bilaterally agreed rules of operation◦ ICPDR report

Example of 2010 flood Example of 2010 flood -- DRBDRB

Example of 2010 flood Example of 2010 flood -- SerbiaSerbia- Unfavorable hydro-meteorological conditions in the first half of 2010

o Prolonged but not extreme rainfall Extremely wet conditions saturated soilo Extremely wet conditions – saturated soil

- Flood waves registered on 39 large and medium rivers, and numerous torrents - Repeated flood waves

Jan + Jun/July +

p- Flood damage - mainly on unprotected areas

Jun/July +Dec

Dec 2009 -Feb 2010

June

DecJune

Dec

Floods caused by Floods caused by extreme hydroextreme hydro--meteorological meteorological phenomenaphenomena

Feb -April Feb -

Aprilphenomenaphenomena

Example of 2010 flood Example of 2010 flood -- SerbiaSerbia

Cause: rapid snowmelt + rainfall (up to Cause: rapid snowmelt + rainfall (up to 15 mm/day15 mm/day) + very saturated soil) + very saturated soilConsequence: 300 houses flooded in unprotected zoneConsequence: 300 houses flooded in unprotected zoneActivity: Reconsideration of flood risk + local flood protection measuresActivity: Reconsideration of flood risk + local flood protection measures

The hydrological situation in 2010 was highly unfavorable, with repeated floods on nearly all national and international rivers -repeated floods on nearly all national and international rivers example of the Sava River, where floods occurred at the very beginning of the year, in the summer, and in December 2010. Fl d d f ti iti l t d f 185 d tlFlood defense activities lasted for 185 days – mostly emergency flood defense was in force and in some areas the emergency situation was declared

Transboundary cooperation◦ International data and forecast exchange in the region need to be◦ International data and forecast exchange in the region need to be

improved – especially in the Drina river basin◦ ICPDR report

Example of 2010 flood Example of 2010 flood –– Drina river basinDrina river basin

TheThe largestlargest and most importantand most importantThe The largestlargest and most important and most important tributary of tributary of the the Sava Sava RRiveriver

Catchment areaCatchment area 2032020320 kmkm22

M t 31 5%M t 31 5%Montenegro 31,5%Montenegro 31,5%

Serbia 30,5%Serbia 30,5%

Bosnia and Herzegovina 37%Bosnia and Herzegovina 37%g %g %

Albania 1%Albania 1%

Example of 2010 flood Example of 2010 flood –– Drina river basinDrina river basinEnd of November/beginning of December 2010 - strong cyclone activity in Montenegro and East Herzegovina - causing heavy rainfall,

Drina, Tara and Piva and several have snow-rain regime - largest flows occur in May and April.

strong southerly winds, and very high temperatures for the time of year.

Snowmelt and abundant rainfall (100 200 mm

Melting of snow in the mountains is usually gradual – disastrous floods are not frequent. Snowmelt and abundant rainfall (100-200 mm

in 3 days) led to a difficult flood situation in the Drina river Basin.

q

Flood waves on the Drina tributaries (Piva, Tara, Cehotina, Lim and Jadar) and the main course were exceptional.

Example of 2010 flood Example of 2010 flood –– Drina river basinDrina river basin

Example of 2010 flood Example of 2010 flood –– Drina river basinDrina river basin

HE Zvornik HE Bajina Basta HE Visegrad

Example of 2010 flood Example of 2010 flood –– Drina river basinDrina river basin

Example of 2010 flood Example of 2010 flood –– Drina river basinDrina river basin

Example of 2010 flood Example of 2010 flood –– Drina river basinDrina river basin

Role of HPP reservoirs in flood events – flood storage?

Enhancement of cooperation between HMSs

◦ Common study of 2010 flood development – lessons for the future

◦ Development of early warning system

◦ Common regional hydrometeorological information system

Reconsideration of flood levels if new levee is constructed on the left bank

between Janja and Bijeljina – large volume of the existing floodplain

HUNGARYCROATIASERBIASERBIA

ROMANIA SERBIASERBIA

Decreased occurrence of ice phenomena

90

100

period 1901-1970.period 1971-2006.

Decreased occurrence of ice phenomena

60

70

80

40

50%

10

20

30

50 00 40 00 50 50 00 00 20 80 00 00

0

BEZD

AN

AP

ATI

N

OG

OJE

VO

UK

OVA

R

N. S

AD

ANKA

ME

N

ZEM

UN

PA

NC

EVO

ED

ERE

VO

RAD

ISTE

GO

LUB

AC

AN

OVA

C

1425

.5

1401

.0

1376

.4

1333

.0

1255

.5

1215

.5

1173

.0

1154

.0

1116

.2

1059

.8

1042

.0

999.

0

Stacionaza (km)

BO VU

SLA P

SME

V. G

R G

D. M

ILA

500550

Decreased duration of ice phenomena

300350400450500

V (o C

)

50100150200250

SNT

V

Floating ice

00 10 20 30 40 50 60 70 80 90 100 110

ТLP (dana)

500550

250300350400450500

NT

V (

C)

Standing ice

050

100150200SN )

Standing ice

0 10 20 30 40 50 60 70 80

ТLS (dana)

1901-1970. 1971-2006.