In Japan, the people and the property are protected from flood damage by levees. This study considers for practical safety of levee management, and enables the degree of damage to be calculated by generalizing numerous factors that relate to a breach of levees based on theoretical equations. The safety of a continuous levee management was evaluated to clarify the damage that would occur in the event of an actual levee crevasse. The levee control processes were evaluated based on longitudinal cross-sectional drawings, showing the relationship between the actual flood water levels experienced and the levee crest height, and the relationship between the water levels that rise as the flood water volume enlarges and the levee crest height.

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In this paper,we will propose the procedure for integrated river basin management considering regional water. Since historical monument,water events and scarcities must be evaluated as cultural heritage for river basin planning. Combining with disturbed runoff model mesh is evaluated with designated six factors,which are consisting necessary items with radar chart.The integration processes are taken from mesh,regional zon,to whole river basin with mathematical aproaches.H river is applied to verify the proposed methodologies in the river basin.

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A dynamic numerical model was developed to examine catchment-scale wastewater management, and the model enabled the evaluation of both water quality and energy consumption. The integrated water resources evaluation system (IWRES) using the Life Cycle Assessment (LCA) technique was applied to optimize wastewater treatment management with the aim of improving water quality and reducing CO2 emissions. Analysis indicated that controlling the wastewater treatment plant (WWTP) with a flocculation treatment has a large effect on reducing CO2 emissions because of the aeration energy reduction.

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Energy source will change from fossil fuel to natural energy. Irrigation system will be request to fulfill the condition of self subsidence of energy balance. To use smart grid technology, irrigation system must be pond system. Construction of lagoons will be required at non-cultivated abandoned fields. Water cycle will be controlled with smart grid technology, freedom of intake will increase and problems of ecosystem and water quality will decrease. If lagoons are used as pumped hydroelectric storage with combination of irrigation ponds, paddy irrigation system will work as battery. These change will decrease paddy area but increase farmers income from battery use.

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[in Japanese]

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In the present study, we developed a global glacier model, HYOGA. Daily time series of glacier mass balance is calculated at 50m vertical sub-grid elevation band at each 0.5-degree grid by the model.
Although the model is only calibrated against the climatology of mass balance observations, the estimated time series of 59-year (1948-2006) global glacier mass balance corresponds well with those of observations. Regional average of glacier mass balance showed that the decrease of glaciers is accelerated after the 1990s.

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[in Japanese]

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It has been indicated that the Eurasian spring snow amount affects the East Asian summer monsoon (EASM) rainfall from both observational and numerical studies. Therefore, to accurately initialize snow could be critical to the improved seasonal prediction of EASM rainfall by numerical models. In this study, we carried out the ensemble simulation using satellite-derived snow water equivalent (SWE; called as SAT ensemble) and the ensemble using SWE derived from spin-up simulation (called as SPN ensemble) using RCM. The excess rainfall over South China and drought over Yangtze River Basin in 2005 were well simulated in SAT compared with SPN. It is indicated that the usage of SWE derived from microwave imager will be an effective way to initialize snow in seasonal prediction.

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[in Japanese]

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[in Japanese]

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In this research, we investigated and analyzed the current production and use of Flood Hazard Maps(FHMs) in Asian developing countries by interviewing practitioners in river management, and explored community based activities for effective use of FHMs.
One of the findings was that the Asian countries had already demonstrated a fairly high "mapping" capability. The next step should be to promote the effective "use" of FHMs to mitigate flood damage. Even in China or Malaysia, they don't distribute FHMs to residents. In this sense, we can provide good examples of Japanese communities where disaster awareness has been successfully developed by making community based FHMs. They should be introduced as examples of good practice to other countries to promote effective use of FHMs.

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[in Japanese]

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A super-hi-resolution hydro-geographical data is used to develop a global river routing model which explicitly represent floodplain inundation dynamics. The simulated river discharge with a newly developed model shows quite better fit to observed river discharge in flat river basins like Amazon. Seasonal variability of simulated inundate area well agrees to the satellite observation of it.

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[in Japanese]

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Recently, the river flood damage in small-and-medium-sized rivers happens frequently by regional localized torrential rain. In this study, we constructed the water level prediction model of the tidal river, Motohiranumabashi gauging station in the Katabira river in Yokohama City, using the genetic programming that was a kind of the artificial intelligent technique, and evaluated accuracy using the real-time data. Studying the water level, the rainfall of radar, the astronomical tide level, the wind direction and the wind speed data for the past two years, the water level prediction was done by using the observed and forecasted weather data. It was confirmed to be able to predict the water level including both the tide and the rainfall-runoff, because of the error margin of 10cm or less.

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[in Japanese]

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Urbanization caused pollutant runoff during rainfall events which so-called diffuse pollution mainly derived from sedimentation on the urban surface and drainage channel during dry-weather periods. It becomes the principal pollutant source in urban river water after point source pollutant purification. The pollutant settled on the river bed is considered to become additional factor for river water quality analysis after rainfall. In this study, the water quality mechanism was analyzed including both effects by inflow pollutants and return pollutant from river bed sediments. Simulation model including the inter-transportation between river water and river bed could estimate pollutant balance during some rainfall events and the potential of river bed sedimentation as the pollutant source.

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[in Japanese]

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Interception is a process whereby rainfall is intercepted by vegetation or buildings before reaching the ground surface. This is an important component in hydrological analysis and modeling. Malaysia produced 14 million tons of palm oil from more than 38,000 km2 of land, making it the largest exporter of palm oil in the world. Despite the large contribution of palm oil industries to socio-economic development, very little work has been documented on the hydrological impacts of palm oil plantation. The aim of this paper is to identify interception loss under palm oil canopy and to predict interception loss under palm oil canopy using original Gash analytical model and assessed the accuracy of the computed results.

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A preliminary study on effectiveness of roof top garden using computer simulation was conducted to mitigate stormwater. In this study, the stormwater performance was simulated using a packaged soil moisture simulation, HYDRUS-1D, with simulation results verified by study site data. Simulations were run using HYDRUS-1D to determine peak runoff, retention and detention time for runoff. Storm data collected as part of a roof top garden project at Department of Irrigation and Drainage, Kuala Lumpur, Malaysia, were used to validate HYDRUS-simulated runoff.

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The variability of precipitation is very large in arid regions in central Eurasia. It is of importance, therefore, to obtain at least daily precipitation data for analyzing the temporal variability. Such proxies as tree-ring, and ice cores cannot provide data with sufficient resolution. The First Historical Archives of China have preserved enormous amount of official documents in the period of Qing Dynasty. They include daily data of the penetration depth of rain into the soilin the period from 1707 to 1911, for more than 200 years. We have selected the documents in and around Hexi Corridor. If the soil wetness information is converted to precipitation data, the past precipitation pattern would be analyzed over the area in the period.

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Changes in water resources due to global warming is an important factor that can critically affect regional development in the Aral Sea area, where large scale agricultural land has been developed by significantly changing regional water balance. Several studies have indicated that large scale development of irrigation during the last half of the 20th century have caused the Aral Sea shrinkage and altered the regional climate. In this study, combined effects of continental scale climate change and large-scale irrigation development on evapotranspiration (ET) was analyzed. Interpretation of hydrological model results indicates that development of irrigation land increased ET, and the irrigation land had kept lower increase in temperature than other land, due to the increased ET.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Soil moisture and soil temperature are important components of the hydrology of land surfaces. Accurate monitoring of these components is essential in understanding energy and water cycles. Microwave remote sensing using satellites is an effective method for collecting global information on land surface hydrology. In this study, we tried to develop an AMSR-E algorithm for soil temperature estimation by upgrading the soil moisture algorithm developed by Koike. The results were verified by comparison of estimated and measured data from Mongolia plateau. The estimated data from this study were good agreement with in-situ data.

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[in Japanese]

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On July 28 in 2008, 5 people were washed away by the rapid-swollen Toga River in Japan. The accident was caused by the localized torrential rainfall that is called Guerrilla-heavy rainfall in Japanese media reports. The rainfall is occurred by cumulonimbus clouds that develop rapidly in a very short time. Therefore, it is difficult to predict such rainfalls, because there were only 5-10 minutes before the river water rushed away after the operational radar monitoring by the PPI scan with low elevation angle firstly caught the rainfall. Now then, as that cloud at early stage consists mainly of iced water droplets in upper atmospheric layers, the volume scan radar monitoring can detect the origin of the rainfall earlier than the operational monitoring.

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[in Japanese]

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The purpose of this study is to evaluate long-term change in daily flow characteristics due to hydrometeorological change free from manmade effects like flood control and water utilization. Daily discharge was calculated from hydrometeorological data measured at observatories located all over Japan by using Tank Model with standard parameters in Japan. The results show that long-term decrease in calculated discharge for low flow period was found, and that over 20 % decrease in 355-day value of calculated discharge was found for about 70% of all objective observatories. Significant decrease in 355-day discharge can be found in Seto inland sea area, Nagano Prefecture, Hokkaido and Nansei islands.

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[in Japanese]

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Daily discharge data of marketable database at representative gauging stations of Class A river system were verified. Quite a few data input errors were found in the database. The error types were described in detail in the paper. Furthermore, daily discharge data of "Discharge Table" were also verified.

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The source and the observational data of the rainfall extreme value record in the world and Japan were revealed, and it revalued it including the reliability and the uncertainty. A lot of things with an indefinite source were included though it was brought together by WMO and NOAA/NWS in the rainfall extreme value record of the world. The case where the value in the thesis was different from the data of local agency and the case where there is a problem in the interpretation based on the content of the description of the quotation thesis were seen, and moreover, these were corrected and annotated as much as possible. Because data that mis-described and was uncertain that was included, that data was verified, corrected, and annotated for Japanese rainfall extreme value records.

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[in Japanese]

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The auther

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[in Japanese]

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