In order to implement policy measures on practical water management to combat the influences of rainfall characteristic variation arising from global warming, it is important to assess risks due to global warming from a practical point of view and develop concrete water management measures including those related to floods and droughts.These risks are evaluated using the results of the regional climate change projection over the next 100 years from the RCM20 regional climate model and GCM20 high resolution general circulation model developed by the Japan Meteorological Agency (JMA) and the Meteorological Research Institute (MRI).

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Many water resources depends on a mountainous district river basin in Japan, especially, snow coverage area play an important role in the water resources, therefore it is necessary to perform development and management of water resources exactly. For that purpose, since it is necessary to grasp a characteristic of runoff correctly, the discharge is calculated using the long-term runoff analysis model of Ando which can conduct analysis from fundamental hydrological data, such as daily rainfall and average daily temperature. The water cycle model has a physical meaning, and can reproduce the changes of a long-term outflow well by comparatively easy calculation. Although this model is already applied even in some mountainous district river basins, there are few research examples in a full-scale snow area. Therefore, it applied to the Sakura river which is a snow area, the conformity of this model was examined in detail, and it aimed at clarifying the water balance in the Sakura river. As a result, when influence of snow and melting snow was not taken into consideration, the correlation coefficient of observation runoff and calculation runoff was very low. However, when the influence of snow coverage and melting snow is taken into consideration, high correlation was shown, and an accurate analysis was able to be conducted. Moreover, the water balance in the Sakura river became clear from the result of the runoff analysis for five years from 2001 to 2005.

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The establishment of technologies for carbon fixation by large-scale afforestation on arid lands is required. Afforestation has been tested at a pastureland near Leonora, Western Australia where hardpan blasting and bank construction were conducted for effectively use of limited rainfall in the arid area.
In the present paper, the change of salt provision and accumulation by the change of water movement has been focused. Salt accumulation tendency was checked by chemical assessment of soils and waters of rainfall, surface runoff water and irrigation water in the afforestation trial site. Both of electrical conductivity and concentrations of water-soluble ions of the soils in the area surrounded by the bank were higher than those at the outside of the area, which indicates that salt accumulation was slowly and gradually proceeding, although the salt damage has not become evident yet five years after the start of the afforestation trial.
The source of each chemical element measured was identified. Na, Ca and Mg were mainly supplied from irrigation, and therefore, their accumulation is expected not to proceed any longer because irrigation was stopped. On the other hand, the source of K and P that are essential elements of plants was found to be rain water. It cleared that the soil concentrations of K and P under tree were higher than that of bare soil, and it estimated that K and P are returned into soil from litters and stemflow of plants.

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A questionnaire survey of intellectual resources in the international cooperation in higher education for solving water and environmental issues was conducted on Japanese universities and institutes, and similar surveys of intellectual needs were conducted in five developing countries (China, Indonesia, Mongolia, Thailand and Tunisia). Objectives of these surveys are (1) to clarify worldwide cognitive structure of water and environmental issues, and (2) to investigate relationship between the resources and needs. Responses to the questionnaire were analyzed using quantification method of the third type, and a map of cognitive space of related keywords was constructed. This analysis suggested that water and environmental issues can be mainly decomposed into three end-members: pollution, disaster, and water use. Keywords, "environment conservation", "environmental education", "environmental assessment" and "ecosystem" are recognized as neutral ones, while the words associated with policy, such as "regional planning", "decision making" and "low making", are recognized to be closely related to water use. Projection of each sample of resources and needs on the cognitive space map showed unique distribution for each country. Hot spot of both resources and needs were formed at an area involving "water cycle", "environment conservation", and "decision making". On the other hand, although some needs for highly special pollutions and disasters existed, there were no resources that should correspond to them.

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Global vegetation index data based on the observation of the satellite NOAA from 1980's enabled us to analyze the vegetation change over continental-scale regions for 20 years and more. An increasing trend of vegetation in boreal forests has been reported by some previous studies. Since the signal of such trend in the vegetation is probably apparent in the ecotone, detailed investigation should be required in the region of ecotone. This study targeted the ecotone from the boreal forest to the tundra in eastern Siberia, and examined the 19-year (1982 to 2000) trend of the satellite-derived vegetation index by using two kinds of parameters, i.e., the annual accumulative NDVI (∑NDVI) and the annual maximum NDVI (MaxNDVI). As a result, we confirmed that ∑NDVI showed an increasing trend in the boreal forest as previous studies pointed out. By contrast, an increasing trend of MaxNDVI was found over the region to the north of the boreal forest (transitional zone between the boreal forest and the tundra). This suggests that signals due to the biomass increase or the vegetation change occurred in the region are detected.

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In middle to large rivers having urbanized and/or agricultural area in their catchments, hypoxia of rivers and lakes is of particular and common concern to water managers. We have conducted a project aiming to clarify what strategies and methodologies are effective to assess the eutrophication-hypoxia and to make counter measures against them in semi-arid regions. As an example, the background and developments of the studies on the San Joaquin River flowing through Central Valley of California are presented. Some novel approaches for investigation on nutrient loadings using stable isotope techniques for nutrient are introduced.

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