The Gages River is important water resources for Bangladesh and India from the old ages, and they have been conflicting over the Ganges water resources. The distribution of water resource from the Ganges is generally advantageous to India which is placed on the upstream of the river. The conflict between Bangladesh and India has been stagnant since they have negotiated only by themselves. In such a case, participation of third party is considered.
In this study, Conflict Analysis is used for modeling. Conflict Analysis is built based on the game theory and it provides algorism to analyze equilibriums among players who have different payoff matrix. Upon this framework of Conflict Analysis, roles of third party are classified and defined into 3 types, ‘Donor’, ‘Coordinator’, and ‘Arbiter’, which are called ‘Complement’ on the whole. This model is applied to the conflict between Bangladesh and India. First, the actual situation is described by using conflict analysis. Second, the condition which is necessary to improve circumstance of current conflict is analyzed, and the role of third party which realizes this condition is considered. Third, one role of complement, ‘Coordinator’, is focused on here in particular, and it is analyzed what condition is necessary so that ‘Coordinator’ improves circumstance of conflict.

View full abstract

Irrigation water is generally estimated by hydrologic models. It is difficult, however, to determine the amount of irrigation water in areas with poor data availability. In this study, irrigation water was estimated by calculating back from rice production at a macro scale. It was assumed that the irrigation water was expressed by the amount of pump irrigation. Kandal and Siem Reap Provinces in Cambodia were chosen as calibration areas for the model and Banteay Mean Chey Province was selected for verification of the model parameter values. The irrigation water was estimated by the IWE model, which consists of two sub-models: a soil water estimation (SWE) model for calculating the water content of each soil type and a total rice production (TRP) model based on yield decrease estimation. The reliability of the model parameter values was low when parameter values related to soil water content were determined for only one province. Thus, the model parameter values were determined for two provinces at the same time. By comparing errors of estimated and actual rice production in two provinces under a unified classification of the soil type, the reliability of the model parameter values was considerably higher. In the result of verification of common parameter values in Banteay Mean Chey Province, a difference between the estimated and actual rice production was less than 10%. This method is considered useful for estimating irrigation water under similar conditions such as water shortage, which is one of the most serious causes of decrease in production.

View full abstract

Record-breaking rainstorms by Typhoon 10 attacked a wide area of Hidaka districts in Hokkaido from August 9 to 10 in 2003. All of river basins distributed in the districts suffered from disastrous economic damages including the eleven toll of dead and missing. The flood flow resulting from heavy rainfalls caused by Typhoon 10 surpassed the 100-year design flood magnitude in the Saru River, which is designated as Rank A river.
The water levels at some points along the Saru River were at the margin of the top of embankments. The peak inflow to Nibutani Dam, which is managed by the Regional Hokkaido Development Bureau, was more than the design flood discharge by 1,000m³⁄s.
The present paper examines in detail the dam operations for flood control at Nibutani Dam, based upon valuable data of forecasted inflows as well as released outflows. It follows from the results of analysis that the gate operations carried out in abnormal situations of the August-Flood played a significant role in reducing the water levels by about one meter at Biratori gauging station and minimizing the flood damages downstream of Nibutani Dam.

View full abstract

Generally, it is a difficult problem to adjust different claims of different interested parties in the process of large-scale and long-term infrastructure development project. Various parties are often in a social conflict with each other concerning their gain and loss that are brought by the project. Such a social conflict is sometimes observed in a water resource development project.
Game theory is instrumental to analyze a social conflict to predict possible consequences and furthermore to suggest rational solutions for each interested parties. Our study depends on a game-theoretical method called conflict analysis.
Under this recognition, it is thought as an important matter to consider circumstances changing with time shifting when a conflict in long-term project is analyzed. In this study, attitude function model and conflict analysis are used to analyze with the algorithm which considers changing process of a conflict depending on time passage. Attitude function model is set to formulate the change of attitude of each party with a set of differential equations.
This model is applied to Nagara River Weir problem which has an important meaning in the history of constructing infrastructural facilities in Japan. First, the history is described with the above model. Second, some parameters are changed to perform a scenario which is set to assume these day's situation. Through scenario analysis as an experiment on the history, some information for the near future is obtained.

View full abstract

This paper describes a simple and easy method for estimating soil solution electrical conductivity (EC_w) and electrical conductivity of saturation extracts (EC_e) in the field from simultaneous measurements of volumetric water content (θ) and bulk soil electrical conductivity (EC_a) made using TDR.
A model that relates EC_w to θ and EC_a (Rhoades et al., 1976) and the EC of an aqueous extract from a soil paste of 1:1 soil-water ratio (EC_1:1) form the basis of this method. The relationship of EC_1:1 to the EC of the soil solution of the same soil of 1:x soil-water ratio (EC_1:x) is assumed to be
EC_1:x=x^-nEC_1:1
where n is a parameter to be determined by experiment but is assumed to be one in this study. The parameters of Rhoades' model are determined based on the EC_w estimated from the EC_1:1 using the relationship assumed above.
This method was applied to two irrigation experiments conducted in an irrigated cornfield in a semiarid region, China and in a grass-covered spot in a humid region, Japan. The results show that this method is effective in monitoring soil salinity in the field.

View full abstract

Examination for correct estimation of nocturnal ecosystem respiration was done using data of micrometeorology, net ecosystem exchange (NEE), soil respiration rate, and 850 hPa wind field, in a Bornean tropical rainforest, Southeast Asia. From results of soil respiration measurement, nocturnal NEE measured under strong stable condition appeared to be incorrect mainly because of inadequate eddy covariance measurement over the canopy. Under week stable condition, adequate measurement of above canopy flux is expected, and nocturnal NEE was almost perfectly dependent on the above canopy flux. Hence, to estimate annual amount of nocturnal ecosystem respiration, an interpolation using NEE measured under week stable condition is effective. During our observation period, clear seasonality in nocturnal friction velocity was evident, and it peaked in January-March. These peak values were generated by direct inflow of a northeast monsoon into our site. This suggests that an unstable condition, where measurement of nocturnal ecosystem respiration is available, depends on Asian monsoon.

View full abstract

Surface boundary layer measurements were carried out in the semi-arid region in northwest China, as ‘HEIFE’ project. In those observation data at an oasis, characteristic diurnal variation of air temperature was observed on fine days in summer.
In the evening, air temperature over an oasis rapidly decreases accompanying a significant vapor pressure peak. This is associated with the calm period of local circulation and effective radiation cooling was observed as the rapid air temperature decrease over oasis. The calm condition was also enhanced by the wind sheltering effect in the oasis plant canopy.
During the air temperature decrease in midnight, small bumps were identified in most of the clear nights. It is found to be associated with the drainage from the Qilien mountains as the downward heat transport due to forced convection.

View full abstract