基于2型模糊集的多目标农业-生态水土资源优化配置

针对西北干旱区灌区生态环境脆弱、水资源短缺、复杂不确定性等问题，以石羊河流域红崖山灌区为例，耦合2型模糊集、模糊可信度约束规划和多目标规划等理论方法，构建了基于2型模糊集的多目标农业-生态水土资源优化配置模型。模型以灌溉水损失最小、生态植被灌溉水满意度最大、生态植被灌溉水费用最小和主要粮食作物经济效益最大为目标，对红崖山灌区10个决策单元的地表水、地下水和粮食作物种植面积进行优化配置。求解模型得到不同可信度水平和不确定性程度下的水土资源优化配置方案。结果表明：耦合2型模糊集的模型能够提供丰富的配置方案，水量对可信度水平的敏感性高于不确定性程度，作物种植结构对可信度水平不敏感。以不确定性程度参数为0.5、可信度水平为0.7时为例，生态植被均通过地表水灌溉，作物通过地表水、地下水联合灌溉，玉米的产量和经济效益均大于小麦。相比前人研究，本研究考虑生态植被灌溉需求，优化结果更加真实合理。本研究可为决策者提供较为符合灌区实际的配置方案，为西北干旱区灌区现代化建设提供科学指导。

Multi-objective Modelling for Optimal Allocation of Agricultural-Ecological Water and Land Resources Based on Type-2 Fuzzy Sets

To handle eco-environment vulnerability, water shortage and complex uncertainties in irrigation districts in arid areas of Northwest China, taking Hongyashan Irrigation District in Shiyang River Basin as an example, a type-2 fuzzy multi-objective programming model for optimization of agricultural-ecological water and land resources allocation was developed. The developed model integrated type-2 fuzzy sets, fuzzy credibility-constrained programming, and multi-objective programming, with the objectives of minimum irrigation loss, maximum ecological vegetation irrigation satisfaction, minimum ecological vegetation irrigation cost and maximum economic benefit of main grain crops. The decision variables were surface water, groundwater and planting structure among 10 decision-making units in Hongyashan Irrigation District. The optimal allocation schemes of irrigation water and planting structure under different credibility levels and uncertainty degrees were obtained by solving the model. Optimal results showed that the model coupled with type-2 fuzzy sets can provide abundant allocation schemes. The sensitivity of allocated water to credibility levels was higher than uncertainty degrees, and the planting structure was not sensitive to credibility levels. When the uncertainty degree was 0.5 and the credibility level was 0.7, the ecological vegetation was totally irrigated by surface water, crops were irrigated by surface water and groundwater, and the yield and economic benefit of maize are higher than that of wheat.Compared with previous studies, the research more considered the irrigation requirement of ecological vegetation, and the optimization results were more realistic and reasonable. The research results can provide decision makers with allocation schemes which were in line with the actual situation of irrigation districts and provide scientific guidance for the modernization of irrigation districts in arid areas of Northwest China.