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In the planning and design of a new irrigation system, one of the most significant uncertainties is the channel capacity, as numerous farmers usually request water at varying times, depending on the crop mixes, climate and season. The capacity of a channel has significant implications for investment and the irrigation performance. This study develops a new method-queuing theory, which can be used to determine the channel capacities in on?demand service. According to the theory, the capacities of service channels depend on the service levels, the average arrival and service rates, and the distributions of arrival and service events. This study incorporates the irrigation requests with queuing modelling, and indicates the channel capacities in terms of the number of the service channels in queuing systems. Both exponential and Erlang distribution models for irrigation events are developed. Ten successive irrigation intervals are also studied with the models. The values of the result from the models show that they are reasonable and reliable by comparing with that of Clement’s first formula.
In the planning and design of a new irrigation system, one of the most significant uncertainties is the channel capacity, as numerous farmers usually request water at varying times, depending on the crop mixes, climate and season. The capacity of a channel has significant implications for investment and the irrigation performance. This study develops a new method-queuing theory, which can be used to determine the channel capacities in on? demand service. According to the theory, the capacities of service channels depend on the service levels, the average arrival and service rates, and the distributions of arrival and service events. This study incorporates the irrigation requests with queuing modeling, and indicates the channel capacities in terms of the number of the service channels in queuing systems. Both exponential and Erlang distribution models for irrigation events are developed. Ten successive irrigation intervals are also studied with the models. The values of the result from the models show that they are reasonable and reliable by comparing with that of Clement’s first formula.