under the influence of global climate changes in the western part of - PowerPoint PPT Presentation

2 nd International Interdisciplinary Conference on Predictions for Hydrology, Ecology, and Water Resources Management: Changes and Hazards caused by Human Interventions and Climate Change, Prague, Czech Republic, 22-23 September 2010 Water security of Sameura dam project under the influence of global climate changes in the western part of Japan MASAHIRO MURAKAMI Professor, School of Environmental Science and Engineering, Kochi University of Technology 22 September 2010

This study examine the vulnerability of water resources under the influence global climate changes in the western part of Japan since 1970s when the sea surface water temperature along the pacific coast of Kochi prefecture has started to increase by steps. The sea surface water temperature along the coast of Kochi prefecture rose more than 2 ℃ in the past 25 years from 1975 to 2000, of which the increasing rate is alarming and among the highest in Japan island, owing to the direct effect of warm Kuroshio (Black) current. Frequent change of sea surface water temperature along the off-shore of Koch has a relation with effect of global scale climatic changes such as La-Nina and El-Nino

TAKAMATSU SAMEURA KOCHI Shikoku Island Fig.1 Location map of the study area

Bonito ride the warm Kuroshio or Black Current north to Sanriku from spring to summer. Fishing season may often be delayed in the future if global warming continues

SASHIMI, Raw Fish of Bonito

Sea Surface Water Temperature Monitoring Legend ：● (Ashizuri ・ Tosa Bay ・ Muroto ）

Fig.6 Annual change of sea surfaced water temperature from 1975 to 2000

Ａｕｇｕｓｔ E-Nino - La Nina and Annual Sea Surface Water Temperature Change in August at Tosa Bay in Kochi, Japan

Glo lobal al Sea Sur urface ce Wate ter r Temper erat ature ure (El-Nin ino) o) Equato tor

Glo lobal al Sea Sur urface ce Wate ter r Temper erat ature ure (La La-Nin ina) a) Equato tor

Atmospheric general circulation model (MRI-AGCM ⇔ Down Scale Modeling

GCM ⇔ Down Scale Modeling Atmospheric general circulation model (MRI-AGCM), which has just been developed by Japan meteorological agency in 1997, suggests the significant influence of global warming on the long-term changes in rainfall patterns and intensity up to the middle of 21 st century (2050). The temporal result of long-term forecasting is alarming with irregular extreme events of droughts and floods to fear the sustainable water use in the western part of Japan. It is, however, the grid size of GCM with 20kmx20m is not favor to simulate the local scale climatic changes including the river basins in Japan.

East Asian monsoon 280km obs 180km 180km 120km 20km 180km obs 20km 20km 180km 20km Asian monsoon is obs evaluated well, but not yet for other parts of 20km the world Mizuta et al. (2006) JMSJ Kitoh and Kusunoki (2007) ClimDyn

Future change in annual mean temperature and precipitation in and around Japan island, projected by 20-km-grid MRI-AGCM (Meteorological Research Institute, Atmospheric General Circulation Model)

Vulnerability of Water Resources Under the influence of global climatic changes A Case of SAMEURA Dam in Kochi, Japan

TAKAMATSU SAMEURA KOCHI Shikoku Island Fig.1 Location map of the study area

Rainfall （ mm ） 2,000 Annual 年間降雨量 トレンド 5 年移動平均 Trend 5 years average Rainfall 1,800 1,600 1,400 1,200 1,000 800 （年） 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 (Year) Long-term trend of annual rainfall changes in Japan (1900 – 2000 )

Anomaly Anomaly % % 降水量平年比 降水量平年比 ト ト レンド レンド 5年移動平均 5年移動平均 Annual Rainfall Annual Rainfall Trend Trend 5 Year Average 5 Year Average 150 150 (High Trend) (High Trend) 130 130 110 110 90 90 70 70 50 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 50 (Year) (Year) 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Fig.2 Anomaly of annual rainfall in Japan (1900 – 2000 )

Anomaly % 降水量平年比 ト レンド 5年移動平均 Annual Rainfall Trend 5 Year Average 150 (High Trend) 130 110 90 70 50 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 (Year) 1,170mm 1,120mm Fig.3 Anomaly of annual rainfall in Takamatsu (1900 – 2000)

Anomaly % 降水量平年比 ト レンド 5年移動平均 Annual Rainfall Trend 5 Year Average 150 (High Trend) 130 110 90 70 50 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 (Year) 2,900mm 3,190mm Fig.4 Anomaly of annual rainfall in Sameura (1900 – 2000)

Drying up SAMEURA Dam in Kochi, Japan (31 July 1994)

Daily Maximum Rainfall at Nakamura, Kochi （ 1951 ～ 2006 ） Daily Maximum Rainfall (mm) Year

Extreme Event Total Rainfall in 23-25 September 1998 High Sea Surface Water Temperature

Creeping Return Period of Daily Maximum Rainfall at Nakamura, Kochi （ Comparison between [1951-1982] and [1951-2006] by Gumbel Method ） Daily Maximum Rainfall (mm) Return Period: 1/100, Max. Daily Rainfall : 382mm (1/57) (1/100) 0) (1/31) Return Period: 1/50, Max. Daily Rainfall : 347mm (1/50)    y P ( x ) 1 exp( e )   y a ( x x ) 0 X : Rainfall ， x 0 : Average of x 0 1/1 1/2 1/5 1/10 1/20 1/30 1/50 1/80 1/100 確率（年） Return Period

Influence of Global – Regional Climatic Changes On Eco-Security (Fish Ecology)

Legend Legend Legend ● Ashizuri, Kochi, Muroto ● Ashizuri, Kochi, Muroto ● Ashizuri, Kochi, Muroto Fig. 5 Monitoring points of sea surface water temperature

Fig.7 Monthly change of sea surfaced water temperature from 1975 to 2000

The annual f i sh pr oducti on t 2000 1800 1600 Kochi Prefecture 1400 1200 Shimanto river 1000 800 600 400 except for Shimanto river 200 year 0 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 Fig.2 The annual fish production

AYU （ Plecoglossus altivelis ） Life Cycle Upper Reaches Summer Season Middle Reaches Lower Reaches Autumn Season Sea Winter Season Spring Season http://www.agri.pref.kanagawa.jp/suisoken/naisui/fishfile/syumei.htm

Ayu （ Plecoglossus altivelis ） stays at off shore of Pacific ocean during winter season

The Change of seawater surface temperature and annual fish production of the Shimanto river The monthly record of sea surface water tempareture ℃ 35 22.5 20.5 ℃ ℃ 30 25 20 15 10 5 0 year 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 Fig.3-B The sea sur f ace w at er t em per at ur e ℃ 23.2 ℃ 27. 0 Fig.3-A Octover 21.8 ℃ 25. 0 The relation between annual Average 23. 0 Nove ｍ ber fish production and sea 21. 0 surface water temperature 19. 0 December (in October to December) 17. 0 <Takahashi;Nishinihon Institute of Technology > 15. 0 year 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 Fig.3-C

Fig. 8 Correlation between annual fish production of Ayu ( Plecoglossus altuvelis ) and sea surface water temperature from October to December

Summary River Improvement Works dam, weirs, embankment, dykes for flood protection and water use Amount of AYU （ Plecoglossus altivelis ） River Restoration Works and Salmon (Naturnaher Wasserbau) Global Warming El Nino and La Nina sea surface water temperature Shimanto River

Concluding Remarks Vulnerability assessment of water resources and prediction of future climatic changes in a framework of the basin scale downscale modeling under the influence of global scale climate change is a new agenda for the integrated water resources policy to manage the future natural disasters including floods, drought and eco-system.

Thank you for your attention