River water quality under normal flow conditions was investigated on two watersheds with complex agricultural landuse in Hokkaido, Japan. The main forms of agriculture are upland farming and livestock farming. If all livestock manure is composted and returned to the field, its amount will exceed the required amount of fertilizer in both watersheds. The excess fertilizer may therefore cause water quality degradation. It is highly probably that the location of livestock yards and riverbank landuse strongly influenced the discharge rate of livestock manure generated in the watershed to the river. The river water quality in the watershed, including rice paddies, showed apparent influences of irrigation water. During the irrigation period, the concentration of nitrogen and phosphorus of the river water itself was diluted and lowered by irrigation water. However, the output of the load of total nitrogen from the rice paddy was larger than the input, because of the good quality of irrigation water.

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The effect of rainfall on the spectral reflectance of a young plant leaf was examined. The spectral reflectance factor for the case with rainfall treatment showed a decreasing tendency in comparison with that without rainfall treatment, especially in the near-infrared region (700∼1000nm) and the short wave infrared region (1000∼2000nm). A maximum difference of the spectral reflectance factor between two cases was 10% in the near infrared region and 15% in the short wave infrared region. The method was presented to detect the vegetation vigor, using a spectral vegetation vigor index (VVI*). The spectral vegetation vigor index was found to be effective for determining the vegetation vigor.

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Hydro-meteorological effect of intercepted snow has been studied using a one-dimensional model through modeling snow-interception. The interception model has been newly developed to consider snowfall based on an existing rainfall interception model. The model can simulate intercepted snow mass and snow depth on forest floor observed previously at Morioka and Sapporo. When snow-interception is considered, we can find large differences on energy and water budgets compared with the cases of no interception or same treatment with rain. For example, the forest works as a heat source for no interception, however, latent heat is dominant and sensible heat is almost transferred from the atmosphere to vegetation when the intercepted snow is considered. Moreover, the snow cover on the forest floor strongly depends on the treatment of interception. On the other hand, the effect of albedo increasing is transient; it does not produce obvious differences of energy and water budgets in winter average. As a result, we find that it is important to heat and water budgets that snow interception is more in quantity and cooler than rain interception, and it is essential to need much energy for melting and evaporating the intercepted snow.

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[in Japanese]

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Water resources activities in the United States have shifted from development to management with special attention to the environment. This trend can be interpreted as a paradigm shift from the traditional national economic development to multifaceted approach of balancing goals and sharing benefits and risks under legislative mandates and environmental constraints. The policy shift is explained in this paper by historical overview of water resources development and examining the roles and responsibilities of federal, state, and local governments, and private sector participation. The major environmental legislations were reviewed, and future directions in water resources management were discussed.

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My objective here is to present an overview of water resources development and management in California from a historical perspective. First, I will make some observations about the growth that the state has experienced in the 150 years of its existence. Then, I will briefly discuss the geography of the state in terms of its water resources together with the water development system that has been constructed. I will describe the nature of our water rights system and then conclude with a discussion of some of the new directions in water policy that we are experiencing.

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