Proceedings of the General Meeting of the Association of Japanese Geographers

Based on the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset, evaluation for the summer monsoon over the Asian and western North Pacific (WNP) sectors is made in terms of reproducibility of the seasonal mean structure. Also investigated is a stepwise eastward progress of convection center from the Indian Ocean toward the WNP in the course of the maturing process of the continental and oceanic monsoons. Most models roughly reproduce seasonal mean broad-scale features on the Asian summer monsoon (ASM), but lower-tropospheric circulation over East Asia (EA) through the WNP and the location and intensity of the North Pacific subtropical high exhibit large inter-model variability. Some of the models fail to reproduce a reversal of the upper-tropospheric meridional temperature gradient over the South Asia and the North Indian Ocean sector. Metrics on the reproducibility of lower-tropospheric circulation of the ASM are also presented, in order to evaluate the reproducibility of the ASM circulation quantitatively. The large inter-model variability over the EA-WNP domains could be attributed to insufficient reproducibility of the oceanic monsoon. In most of the models, the stepwise eastward progress of convection over the South China Sea and WNP commences in May almost concurrently with large-scale circulation, whereas the eastward progress of convection is faster in most of the models than in the observation over the WNP. It is suggested that a teleconnection pattern associated with an intensification of convective activity over the WNP in mid-July is one of the key phenomena both the observation and the coupled models, given the withdrawal of Baiu rainy season around Japan. The analysis based on metrics concerning the stepwise eastward progress of convection over the WNP and its vicinity suggests that these models still have some difficulties in reproducing the stepwise eastward progress of convection accurately.

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In Mongolia where agriculture and pastoralism is the basic industry, climatic disasters result in serious damage to the national economy –such as the last historically disastrous drought and dzud (1999-2002). In addition, the climate change and desertification will cause significant influence on people living there. In this study, we simplify a tree regression diagnosis model we developed before, in order to use it for the future by inputting outputs of an Earth system model (designed for climate change projection), and assess dzud risk in Mongolia for the rest of this century. The result map presents that in comparison to other regions dzud will be more frequent in the central-south to the north-east part of the country, and particularly tree provinces in that region have risk of the most disastrous dzuds.

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Temporal aspects of the urban heat island(UHI) of Naha, Okinawa are demonstrated using differences of screen level air temperature observed at an urban(downtown parking lot)and rural (parking lot neighboring to waste) site for one year. Temporal aspects of the lapse rate of urban and rural area are also demonstrated using differences between screen level air temperature and aloft air temperature (above the roof) observed at a downtown elementary school and differences between screen level air temperature (parking lot neighboring to waste)and aloft air temperature (above the roof of a rural building) for one year. The results show as follows: Diurnal variation of UHI magnitude can not be seen in cloudy and rainy days but in clear days. There is no diurnal variation of urban lapse rate which is under 0.01 C/m (natural condition). Daytime rural lapse rate(RLR) is nearly 0 C/m but RLR increases from sunset. The maximum RLR occurs at about sunrise.

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I Objective
The Amur River which is the international river is the 4,350km in length and 2,051,500km² of the basin area. There are the large wetlands in the mid Amur River area near Khabarovsk in Russia. The flood occurs almost every year during the monsoon season.
In this study, the feature of the flood in the mid Amur Basin was clarified by the numerical analysis. Secondly, the wetlands on which landforms had flood control basin capability were cleared.
II Method
The precipitation data (Jan. 1910- Apr. 2003) possessed by Royal Netherlands Meteorological Institute were used to clarify the feature of flood. The analysis method of Hoshi (1998) was used. The data of monthly max flow in Amur River by Pacific Institute of Geography, Department of Hydrology, Far East Center, Academy of Sciences, Khabarovsk were used and the relationship between the precipitation and max flow were clarified.
The wetlands were classified on the satellite data by the method of Murooka et al. (2007).
III Conclusion The distribution of the monthly max precipitation fitted the exponential distribution (chi-square test p>0.05). The precipitation of 832 mm/month would occur once in 100 years. 717, 565, 447, 324 would occure in 50, 20, 10, 5 years. The monthly average precipitations were below 50mm/month from Nov. to Mar and over 70 from Jun. to Sep. On June and Aug., more than 100.
When the monthly precipitation in Khabarovsk were put on x-axis and the average monthly flow were put on y-axis, the logistic curve were fitted (ANOVA, significance level was below 0.001) (Fig). That is, when the precipitation is over 84.0mm/month which is 95% of max flow, the river water overflow and flood occurs.
The significant correlation between the precipitation and the wetland area on the floodplain were indicated. As a result, the wetlands on the floodplain served a most important role as flood control basin.
Reference
1) Hoshi, K. 1998. The method of evaluation for flood peak probability. Journal of Civil Engineering Research Institute Hokkaido Development Bureau. No. 539: 34-40. 2) Murooka, M., Haruyama, S., Masuda, Y. 2007. Land Cover Change Detected by Satellite Data in the Agricultural Development Area of the Sanjiang Plain, China. Journal of Rural Planning 26: 197-202.

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