To investigate the characteristics of turbulence components above a hill evergreen forest canopy on a mountain slope, turbulence was measured over a forest in Northern Thailand. There were many trees taller than 30m. Each fluctuating component of the three–dimensional wind velocity(u, v, w)was analyzed using the eddy correlation method. The characteristic of turbulences were the occurrence probabilities of positive values in the fluctuating components, the skewnesses, the ratios of the standard deviation to the friction velocity(σ_u ⁄ u_* , σ_v ⁄ u_* , σ_w ⁄ u_*), and the correlation coefficients among each fluctuation. We clarified the distributions of the characteristic of turbulence, and the relationships between atmospheric stability and each ratio of the standard deviation to the friction velocity.
The results showed there were wide distributions of the characteristics of turbulence, even in the neutral conditions(|(z−d)/L|<0.05). Distributions of the ratios of the standard deviation to the friction velocity were systematically categorized by the wind direction and the wind speed. An effect of a distance from a nearest tree was shown about σ_w ⁄ u_* and σ_v ⁄ u_* , but about σ_u ⁄ u_* this tendency was weak. σ_w ⁄ u_* in the weak wind was approximately 1.25 which was the character of general turbulence. σ_w ⁄ u_* in the strong wind was different with each wind direction. The mean values and standard deviations were σ_u ⁄ u_*=1.94±0.32, σ_v ⁄ u_*=1.72±0.49, and σ_w ⁄ u_*=1.31±0.22, respectively. σ_w ⁄ u_* was corresponding to the value which had been observed on other canopies, but σ_u ⁄ u_* was smaller than the value of short vegetation.

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Recently, eutrophication of reservoirs has become an important environmental problem. Some of the adverse effects of eutrophication phenomenon include, deterioration of landscape due to water bloom and red tide, creation of unpleasant odors in water supply and clogging of water structures. It is widely believed that the eutrophication of water is aggravated by larger retention time in reservoirs and lakes. In order to test this hypothesis, we examined the relationship between phytoplankton abundance and the retention time of reservoirs in different regions of Japan. The result of analysis indicates that the increased retention time alone does not cause an increase of phytoplankton. In fact, there is an ‘optimum’ retention time where the growth becomes maximum and decreases thereafter. It was also found out that the phytoplankton decreases as the water flows from upper reaches of the reservoir to the lower reaches.

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This study aims to investigate efficiency of the disaster information at the time of real heavy rainfall on the emergency management, mitigation, and human evacuation. Data of the information, damage and reaction of the people at Higashiyama town and Kawasaki village, Iwate prefecture are obtained through internet, field investigation, and questionnaire (the number of respondents: 700) in August 2002. The damaged area has repeatedly suffered flood and the typhoon No.0206 in July 2002 caused the worst damage over recent 30 years. During the heavy rain, the only 5% respondents to get real time rainfall and river water level through Internet, the 70% respondents did not know the system to obtain the information, suggesting the less known system among the residents even through real time data with the various information is available. However, the 74% of respondents at Kawasaki village answered that we referred to rainfall and water level information for reaction against disaster. The village office of Kawasaki announced the rainfall and water level information through the disaster wireless service, which were obtained by the people, meaning that the wireless service is more efficient than the Internet. The success or failure of carrying household goods from their homes is closely related with the use or non-use of the data of rainfall and water level information. This implies the importance of the disaster information such as rainfall and water level in the river in real time and prediction. Internet is one of the most efficient ways to provide with the information, however the access and use of it are still problem for the people.

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We tested some tipping-bucket flow meters(15.7cc, 75cc, 100cc and 200cc)to correct the errors in the flow measurement. We found that the amount of water for one tip increases with the increase of inflow flux. The error characteristics show two typical features. In case of tipping-bucket flow meters bigger than or equal to 75cc, inflow flux has linear relationship with the amount of water for one tip. When we know the amount for one tip at inflow flux is almost zero, the use of the same compensation parameters produces merely 3% error. On the other hand 15.7cc tipping-bucket flow meters show both linear and parabolic type relationships between inflow flux and amount of water for one tip. About 10% error occurred if the same compensation parameters were used. Hence, each 15.7cc tipping-bucket flow meters needs different compensation parameters for the accuracy.

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A new method of measuring the area-averaged precipitation was developed. We use the vertical pressure gradient, the hydrostatic equation and the vertical velocity of raindrops. The detection area for 10-min average precipitation was experimentally found to be a 7.3km radius circle when the barometer′s vertical distance was 122.9m. It is larger than that of a rain gauge. However the error analysis shows the 174% random error for this method. The most significant error source was the error of pressure difference.

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The Mekong River is an international river running through 6 countries from China, Myanmar, Lao PRD, Thailand, Cambodia, to Viet Nam. Social strife in this geopolitical region has taken heavy toll on its people from decades of cold war, Viet Nam war, and to Cambodian civil war as well as some border conflicts throughout the years. As the results, this region is one of least developed part of the world, as seen reflected in peoples’ low living standard, and social development.
The change in political wind has provided an opportunity for settling down circumstances, and overcoming difficulties that stem their different perspective and expectations among the 4 riparian countries of Lower Mekong Basin. (Super power China and isolated Myanmar are not part of this yet), By Mid 1990s, the 4 government reached the Agreement on “Cooperation for the Sustainable Development of the Mekong River Basin”. In 5 April 1995, Mekong River Commission (MRC) was re-established under this agreement as an executing body.
This document introduces the process of reaching the Agreement, its organizational structure, its programme activities and the perspective of its future mission. It also gives general information of the Mekong River Basin. More importantly, the document describes the behaviour, characteristics and quality of its interactions under this cooperation agreement, among many other activities & initiatives in Mekong Basin. This document intends to supply information & perspectives of the Mekong Basin, in hoping that understanding of the region dynamism will help sustainable development of the Mekong River Basin, in a wise utilization of water related resources with due consideration to nature, society, environment and the people in the basin.

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