The operation of discharge and response delay in an open channel irrigation system are discussed using mathematical analyses and experimental evaluations. Analytical treatments are made based on the linearized diffusion analog model.
It was clarified that the dimensionless distance and time obtained as a result of the analyses were useful in describing the operation response. Also, the phenomena of the response to the operations were transferred downstream as dynamic, dynamic-kinematic and kinematic waves according to the dimensionless factors.
The approximated equations for predicting the response were derived from a linearized diffusion analog model within the effective range of distance. The validity of this approximation was confirmed by experimental evaluations.
The waves in an open channel regarded as the first delay system is discussed. The equations for evaluating the parameters of the first delay system were derived from the aforementioned approximation and the condition of continuity. The validity of using the first delay system was confirmed by computer simulations. Inversely, gate control corresponding to the desired response at the irrigation field is discussed using the first delay system.

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This study examined the subjective responses of households in the decision to move house and the preferences on residence as well as the objective responses in housing relocation subject to certain reference points. The results indicated that housing readjustment and demand for specific housing tenure were the major determinants of force in mobility. The level of accessibility of the household's daily activity sites and the quality of neighborhoods were also high priorities in residential preferences. Only specialized Qrouns of households yielded specific patterns of housing relocation.

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A series of analyses on the seasonal characteristics of the rainfall-runoff relationship was performed for the catchment area of the Muda and Pedu Reservoirs (1, 155.1km²), which is covered by primeval tropical forests. Of the annual mean runoff of 638mm, the dry (Jan.-Apr.), intermediate (June.-Aug.) and wet (Sept.-Dec.) seasons account for a seasonal runoff of 110 mm (17%), 159mm (25%) and 369mm (58%), respectively. Seasonal runoff percentages averaged 26%, 19%and 37%for the three seasons. Based on a daily analysis using 12 years'data, the average direct runoff percentage was estimated at 12.7%for the dry season, 16.0%for the intermediate season and 31.7%for the wet season. In taking account of the seasonality, three sets of rainfall-runoff models (altogether 9 runoff estimation equations) were constructed for the catchment area. These models appear to be applicable for the estimation of long-term runoff for irrigation planning and management.

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