introduction of the global hydrological simulation system ... · introduction of the global...
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(+1.71E-02)(+0.88E-02)(+0.29E-02)(+0.09E-02)
Introduction of the Global Hydrological Simulation System using GSMaP
References[1] Takata, K., S. Emori, and T. Watanabe, 2003: Development of the Minimal Advanced Treatments of Surface Interaction and RunOff (MATSIRO), Global and Planetary Change, vol.38, pp.209-222. [2] Yamazaki, D., S. Kanae, H. Kim, and T. Oki, 2010: A physically-based description of floodplain inundation dynamics in a global river routing model, Water Resour. Res. 47, W04501, doi:10.1029/2010WR009726.[3] Yoshimura, K., T. Sakimura, T. Oki, S. Kanae, and S. Seto, 2008: Toward flood risk prediction: a statistical approach using a 29-year river discharge simulation over Japan, Hydro. Res. Letters, vol.2, pp.22-26, doi:10.3178/HRL.2.22
Kosuke Yamamoto 1・Takeshi Hibino 2・Kei Yoshimura 2・Riko Oki1・Misako Kachi1
1Ea r th O bs e r vat i o n Re s e a rc h C e nte r ( EO RC ) , J a p a n Ae ro s p a c e E x p l o rat i o n Age n c y ( JAX A)2 I n st i tu te o f I n d u st r i a l S c i e n c e , U n i ve rs i ty o f To kyo
Introduction
System Overview
Long-term Trend
Summary & Conclusion
Experiment Spatial Resol. Temporal Resol. Period Latency Forcing
JRA55 ver.0.5-deg(Land)
0.25-deg(River)3hourly,
daily, monthly1958-present
About3.5days
Surface meteorological parameters by JRA55
MODIS ver. 〃 〃 2002-present About 5daysSame as JRA55 ver. except
solar radiation from MODIS
GSMaP ver. 〃 〃 2000-presentAbout 20days
Same as JRA55 ver. except rainfall from GSMaP
Now OPEN !! http://www.eorc.jaxa.jp/theme/water/
• Though GSMaP offers relatively small amount of precipitation compared to JRA55, increasing trends of high percentile precipitation in tropics are well reproduced (bold letter in the left fig. shows statistically significant regression coefficient).
• MODIS radiation works to suppress net evapotranspiration.
• Runoff rate of GSMaP ver. is higher than the rests. This may be due to the large spatial & temporal variability of satellite products compared to the reanalysis datasets.
TE W
g [m
/m]
SPL3SMAP soil moisture [cm3/cm3]
R=0.60RMSE=0.13MAE=0.09
R=0.61RMSE=0.14MAE=0.10
R=0.61RMSE=0.15MAE=0.11
• Global hydrological simulation system named “Today’s Earth (TE)” has been developed and its accuracy for several essential output variables is tested by using in-situ and satellite observation data.
• Need to confirm and improve runoff generation process in the model to make it adapt the realistic spatial & temporal variability of the precipitation suggested by GSMaP.
• Further analysis on seasonality and regionality of accuracy is required for actual use of the system.
(c)GSMaP(a)JRA55 (b)MODIS
The land water cycle is a key element of the climate system representing all water exchange processes at the surface. For better understanding, JAXA has developed the global land simulation system named “Today’s Earth (TE)” under the joint research with the University of Tokyo. The TE system aims to :✓ produce and evaluate long-term land water cycle dataset based on satellite observation and reanalysis data✓ contribute the society as a part of the climate services by calculating risk indices of water hazards, particularly floods
This study introduces TE system and shows its overall validation and long-term trends.
JMA 55-year Reanalysis& Satellite Obs.
Forcing Land Surface Model(MATSIRO5)
River Routing Model(CaMa-Flood)
Hydrological Variables& Risk Indices
Validation
Validation
R=0.52RMSE=3780MAE=3060Bias=-589
R=0.50RMSE=6330MAE=5160Bias=1570
R=0.54RMSE=3730MAE=3000Bias=-200
■TE-Japan• As regional version of TE, “TE-
Japan” system (spatial resol. : 1km) is now under development.
• Hindcast of 2018 Japan floods were done and the authors confirmed that the system precisely reproduced the inundated area compared to the aerial photograph information.
GSMaP precip. at 0:00(JST) July 7th, 2018
Inundation area[m2] by TE-Japan
Inundation area estimatedbased on the areal photo by GSI
Photo by YOMIURI online
※In-situ data from The Global Runoff Data Center
ii) Evap.i) Precip.
iii) Runoff
i) Precip.
(+8.00E-02)(+6.90E-02)(+2.70E-02)(+0.60E-02)
ii) Evap.
iii) Runoff
JRA55 ver. MODIS ver. GSMaP ver.
Precip.(land) 800.3 (800.3) 743.4
Evap. 647.9 633.9 548.2
Runoff 102.0 108.0 108.9
Unit : mm y-1
(Zo
nal
mea
n o
f 3
0S-
30
N)
JRA55 ver. GSMaP ver.