International Sava River Basin Commission

Transcription

1 International Sava River Basin Commission Pilot project on climate change: Building the link between the Flood Risk Management planning and climate change assessment in the Sava River Basin climate change impact on flood discharge - hydrology report - part two University of Ljubljana; Faculty of Civil and Geodetic Engineering

2 Pilot project on climate change REPORT ON METEOROLOGICAL PART OF DEVELOPMENT OF CLIMATE PROJECTIONS FOR SAVA RIVER BASIN part one CLIMATE CHANGE IMPACT ON FLOOD DISCHARGE - HYDROLOGY REPORT - part two FLOOD PROTECTION AND ADAPTATION MEASURES part three

3 CLIMATE CHANGE IMPACT ON FLOOD DISCHARGE - HYDROLOGY REPORT prof. dr. Mitja Brilly. doc. dr. Mojca Šraj. mag. Andrej Vidmar. Miha Primožič. mag. Maja Koprivšek.

4 The HBV model of SRB List of sub-basins. # Sub-basin number Sub-basin name Stream Sub-basin area [km 2 ] 1 I. Sava I Sava II. Sava II Sava III. Kolpa Kolpa IV. Sava III Sava V. Una Una VI. Sava IV Sava VII. Vrbas Vrbas VIII. Sava V Sava IX. Bosna Bosna X. Sava VI Sava XI. Drina I Drina XII. Drina II Drina XIII. Sava VII Sava All sub-basins

5 Model structure

6 Input data The following input data are required to calibrate/run the model: -precipitation (32 measurement stations) -temperatures (8 measurement stations) -discharge data (12 measurement stations) -potential evapotranspiration (8 stations) For the calibration - period from June 1 to December 31, For the verification - period September 1, 1978 to November 30, 1978

7 Model calibration peak discharges in m 3 /s.

8 data transformation The precipitation data in the meteorological report are in raster form and we collected the data from the cell in which the precipitation station was positioned. Maximum daily values of precipitation measured in 1974 are slightly lower than the values of E-OBS. There is a high discrepancy between the E-OBS data and the measurements in the area of the Dinaric Mountains, especially in Montenegro Summer daily precipitation is slightly higher than in autumn due to higher evaporation. However, runoff in the autumn season is much higher and for further calculations and analysis we chose the autumn values

9 Precipitation data Probability of maximum daily precipitation (mm) in a year and data from Table 8. return period Max prec. V1 V2 V3 V4 Station name in 1974 EOBS_20 EOBS_100 20_ _41-70 Ljubljana 190,7 106,3 72,2 95,8 88,5 110,0 110,0 148,0 Rateče 214,9 121,2 83,2 42,6 131,9 171,1 147,5 191,3 Zagreb 117,2 65,9 45,2 34,5 43,6 50,3 52,0 67,4 Slavonski brod 104,1 59,1 40,9 31,6 31,1 38,6 36,3 47,8 Bihač 155,3 89,5 62,8 82,9 69,7 83,4 81,0 101,8 Bugojno 119,9 66,2 44,5 40,4 38,0 50,4 44,8 66,6 Sarajevo 120,0 67,0 45,5 36,0 37,6 42,6 49,6 66,5 Banja luka 86,0 57,4 45,8 56,2 34,0 44,0 38,9 53,4 Beograd 126,8 66,3 41,9 39,4 36,0 46,1 46,4 66,7 Sjenica 89,9 53,3 38,5 45,1 42,9 51,3 55,9 77,6

10 E-OBS data. Precipitation distribution for 100-year return period

11 climate change - modelling of discharges The hydrological model represented in Chapter 1 was used for modeling of the impact of climate change forecasts on the Sava discharges at selected stations. For modeling of climate change the same data as those for the calibrated model for 1974 were used. Variant calculations with change of set of maximum daily rainfall Variants of forecast calculated with increase of temperature: 0.8 o C in autumn in the period , 1.8 o C for autumn in the period and 2.9 o C in the period

12 Result of modelling recent climate flood peaks (in m 3 /s). Sub-basins WS measured calibrated EOBS_ret20 EOBS_ret100 Sava I Čatež Kolpa Šišinec Sava II Crnac Una Kostajnica Sava III Jasenovac Vrbas Delibašino selo Sava IV Slavonski Brod Bosna Doboj Sava V Županja Drina I Bajina Bašta Drina II Kozluk Sava V Sremska Mitrovica confluence with Danube

13 Result of modelling climate change flood peaks with EOBS data for 20-year return period (in m 3 /s). Subbasins WS EOBS m 3 /s m 3 /s 41-7 m 3 /s m 3 /s % % % Sava I Čatež Kolpa Šišinec Sava II Crnac Una Kostajnica Sava III Jasenovac Vrbas Delibašino selo Sava IV Slavonski Brod Bosna Doboj Sava V Županja Drina I Bajina Bašta Drina II Kozluk Sava VI confluenc e Sremska Mitrovica average max min

14 Results of modelling climate change flood peaks with EOBS data of the 100-year return period (in m 3 /s and %). Subbasins WS EOBS m 3 /s m 3 /s 41-7 m 3 /s m 3 /s % % % Sava I Čatež Kolpa Šišinec Sava II Crnac Una Kostajnica Sava III Jasenovac Vrbas Delibašin o selo Sava IV Slavonski Brod Bosna Doboj Sava V Županja Drina I Bajina Bašta Drina II Kozluk Sava VI Sremska Mitrovica confluenc e average max min

15 Probability function - WS Čatež 100 ret.p. water level will increase for 225 cm

16 Probability function - WS Crnac 100 ret.p. water level will increase for 82 cm

17 Probability function WS Slavonski Brod 100 ret.p. water level will increase for 113 cm

18 Probability function WS Županja 100 ret.p. water level will increase for 181 cm

19 Probability function - WS Sremska Mitrovica 100 ret.p. water level will increase for 26 cm

20 SRB Hazard characteristics Orographic impacts in head part of watershed of Alpine and Dinaric mountains, reduced by karst poljes and alluvial deposits. Huge inundated areas downstream of town Sisak (flood discharges drop down). Sediment transport on mouth of tributaries and main stream. Hystorical events, the Drina River 1896 flood