Development of an irrigation vulnerability assessment model in agricultural reservoirs utilizing probability theory and reliability analysis

• An irrigation vulnerability assessment model using reliability analysis is proposed.
• Irrigation vulnerability assessment is based on a probabilistic analysis technique.
• An irrigation vulnerability assessment model was applied to agricultural reservoirs.
• Vulnerability probabilities were compared with the design drought frequencies.
• Water supply performance was a quantitative evaluation based on probability.

The primary goal of water resource management is to maintain a secure and reliable supply of water that can meet the demands of responsible water resource planning. The development of a sustainable agricultural water management system is necessary to evaluate the capability of the water supply to adapt to changes in environmental conditions in relation to the passage of time. Because each reservoir has specific properties related to its watershed, irrigation district, and changes in inflow, they are essential to improve the current assessment methods. The purpose of this study is to propose an irrigation vulnerability assessment method that considers a probability distribution that uses time-dependent change analyses of the irrigation water requirements by paddy fields and the water supply capacity of agricultural reservoirs. Irrigation vulnerability indices are estimated to evaluate the performance of the water supply on the agricultural reservoir system using a probability theory and reliability analysis as an objective method to evaluate the stability of the water supply. The work presented in this paper addresses the potential impact of environmental changes on water supply and demand, as well as the associated reservoir operation performance, with an emphasis being placed on the probability of the current vulnerability. The environmental impact is particularly marked for irrigated paddy fields that utilize a reservoir agricultural vulnerability evaluation model to classify the relative and quantitative severity of irrigation vulnerabilities. Thus, it is a recommended practice in the development of water supply management strategies to manage the risk of an uncertain future.