The 5th International Coordination Group (ICG) Meeting GEOSS Asian Water Cycle Initiative (AWCI), Dec. 16, 2009. Impact assessment on disasters Eiichi Nakakita Disaster Prevention Research Institute Kyoto University, Japan
Kakushin Team 3 Projection of changes in extremes in the future with very-high resolution atmospheric models A. Projection Extreme event projection by very high resolution atmospheric models Meteorological Research Institute (MRI) Japan Meteorological Agency (JMA) Advanced Earth Science & Technology Org. (AESTO) uncertain information B. Uncertainty Evaluation and reduction of uncertainty in global warming projection Meteorological Research Institute (MRI) Japan Meteorological Agency (JMA) Advanced Earth Science & Technology Org. (AESTO) C. Risk assessment Prediction and evaluation of disaster environment Disaster Prevention Research Institute (DPRI), Kyoto University Assessment of climate-change impacts on flood risk and its reduction measures on global and local scales International Centre for Water Hazard and Risk Management (ICHARM), 5 data Requirement of types of output Significance of GCM and RCM output for disaster environment uncertain information Public Works Research Institute
Extreme event projection by very high resolution atmospheric models MRI / JMA / AESTO Atmosphere- Ocean model 180km mesh High-resolution global atmospheric model 20km mesh Regional cloud resolving model by nesting 5km, 1km mesh Atmos phere SST Ocean 100-50km mesh SST=Sea Surface Temperature Predicted SST SST Boundary condition A1B Scenario Present SST Atmos phere 1979-2003 Boundary condition Near Future 2015-2039 6 Future 2075-2099 Year
DPRI / Kyoto-Univ. Slope Mountains River Habitable Area Coastal Area Output from GCM Prediction and evaluation of disaster environment in Japan Hourly precipitation, temperature, water vapor, wind velocity, radiation and air pressure (25 years time series (20km) and ensemble predictions (60km) for current, near future and century end) Regional climate model (RCM_5km, RCM_1km) Interpretation of output Surface hydrological model Stochastic typhoon model Probability density function of extreme value(depending on spacio temporal scales) Stochastic precipitation model (time series depending on spacio temporal scales) Various Models (with longterm run) Soil production Soil runoff Rainfall runoff Reservoir operation Sedimentation and transportation of soil River channel flow Inundation including underground shopping mole Building damage by strong wind Storm surge Evaluation Decreasing of safety against landslide, debris flow, flood, draught, storm surge and strong wind. Assessment of current protection system and proposal of alternatives
East Asia KAKUSHIN 20-km mesh, hourly Precipitation (mm/h) It is the typhoon resolving output that has realized the impact assessment of Japanese disasters Sea Level Pressure (hpa)
Difference Between GCM Output and TRMM Observations June October Monthly Mean Rainfall(30 month average) TMI2A12 2002 2007 GCM 1999 2004 GCM Present TMI By Konoshima and Nakakita, 2008, Kyoto University
Future Changes of Annual 15-days Rainfall in Mekong 15 days Present 1979 2003 Future 2075 2099 Earlier shift of long extreme rainfall occurrence would move the flooding peak earlier.. The pattern of Future 15 day rainfall is similar to the pattern of year 2000. By Konoshima and Nakakita, 2009, Kyoto University
Occurring Month of Monsoon Onset and Offset Onset Offset The earlier monsoon offset might decrease the present flood peak occurring in September. Monsoon offset occurs early in Mekong, in future climate. Present 1979 2003 By Konoshima and Nakakita, 2009, Kyoto University Future 2075 2099 Monsoon onset and offset defined by Matsumoto, 1997
Tracks of tropical cyclone
Typhoon track (GCM Present and Best Track) Difference of generation numbers is 175 for 25 years, 7 per year 1979~2003: GCM Present Generation number: 483 Average: 19.32/year By Mase et. al, 2008, Kyoto University 1979~2003: JMA BestTrack Generation number: 658 Average: 26.32/year
Typhoon track (AGCM Present and Future) Difference of cyclogenesis numbers is about 100 4 typhoons decrease per year 1979~2003: AGCM Present Cyclogenesis number: 483 Average: 19.32/year By Mase et. al, 2008, Kyoto University 2075~2099: AGCM Future Cyclogenesis number: 388 Average: 15.52/year
Cyclogenesis typhoon numbers (AGCM Present and Future) North Pacific 178 139 Approaching to Japan 36 (20.2%) 30 (21.6%) Chance of approaching typhoon in the future is higher than present. By Mase et. al, 2009, Kyoto University
Lowest center pressure of typhoon By Mase et. al, 2009 Kyoto University Present Future Lowest center pressure 987.3 hpa V 984.7 hpa Lowest center pressure in the future is smaller than present. => Stronger typhoon accrues in the future.
20kmGCM Maximum Value Around Japan Present Near Future End of 21 Century Under Computation Hourly Rainfall Present Near Future I hour averaged wind velocity By Oku (2008), Kyoto Iniversity. End of 21 Century
Pilot study using a distributed runoff Model (eg. Yodo River basin; 7,281km 2 ) Nagoya Kobe Osaka Kyoto
Possible changes in the number of floods requiring dam operation and emergency dam release (Yodo River) 80 Number of floods 70 60 50 40 30 20 Number of floods with dam operation Number of floods with emergency dam release 10 0 1981-2000 2031-2050 2081-2100 By Sayama et al. (2008), Kyoto Iniversity.
Increasing of annual maximum discharge (End of century/present) By yamaguchi et. al, 2009, Kyoto University
Super Typhoon by Dynamic DS Super Typhoon projected by CReSS (Storm Resolving Storm Simulater) By Prof. Tsuboki, 2009, Nagoya University
TF2716 projected by GCM20 + CReSS Minimum low pressure 866 hpa 200km By Prof. Tsuboki, 2009, Nagoya University
TF2716 projected by GCM20 + CReSS :Wind velocity(contour) and liquid water mixing ratio (Color) Max. wind velocity :110m/s 100km By Prof. Tsuboki, 2009, Nagoya University
SF0508 projected by GCM20 + CReSS Total rainfall amount: 500~800mm By Prof. Tsuboki, 2009, Nagoya University
Virtual Shifting of typhoon s initial position NHM-5km Virtual Shifting of typhoons initial position by keeping potential vorticity same AGCM20 Dynamic downscale by RCM Worst impact assessment on Land extreme wind and rainfall Ocean storm surge and wave height By Prof. Ishikawa et. al, 2009, Kyoto University
Conclusion 1 The future aspects The occurring month of long range abnormal rainfall advances from September to August in the future climate in Lower Mekong River basin. The earlier shift of extreme rainfall phenomena in future climate condition would move the annual flooding peak earlier, and decrease the flood in September, in the lower part of the Mekong River basin, such as Tonle Sap and Mekong Delta. Since people s lifestyle is adapted and cultivated to the timing of the seasonal flood (beginning, peak, and ending) in these above area, the shift and changes of the annual flood would impact greatly upon people and their livelihoods.
Conclusion 2 How do you think about the fact the super typhoon was projected based on physically based atmospheric model even there is uncertainties in its occurrence. It should be emphasized that the scenario based discussion is also very important as the worst impact assessment. To realize this, it is important to prepare physically based scenario by the physically based virtual shifting of typhoon s track and the dynamic downscaling. Future change in moving speed is also very important. ex. Disaster in Taiwan, Aug., 2009. Total amount of almost 3,000mm in three days occurred.
Thank your for your attention!
Future Increasing Ratio of 100 year rain of D [hours/days] Rainfall Type A 3 hours 6 hours Type B Flash flood triggered by short range rainfall would 1 day become more serious problem in future. Type C 7days 15 days accumulation mean variance 3 hrs 1.087 0.152 6 hrs 1.083 0.139 24 hrs (1day) 1.073 0.103 Future increasing ratio of short range extreme rainfall is 7days 1.050 higher than the ratio of longer range extreme rainfall. 14 days 1.040 Future 100 year rain /Present 100 year rain 0.104 0.035
20kmmesh 100km scale 100 year rain Future Increasing Ratio of 100 year rain of 1 day Rainfall GCM Future GCM Present