基于AquaCrop模型的水稻多目标灌溉制度优化研究

Optimization of multi-objective irrigation schedule for rice based on AquaCrop model

【目的】优化现有水稻灌溉制度,节约灌溉用水量,减少稻田氮磷流失量以降低面源污染风险。【方法】构建了基于AquaCrop模型和NSGA-Ⅱ算法的水稻灌溉制度模拟优化模型,利用水稻田间试验数据,开展以产量最大、氮磷流失量最小、灌水次数最少的3种目标组合(产量-氮磷流失量(Y-TNP)、产量-灌水次数(Y-N)、产量-氮磷流失量-灌水次数(Y-TNP-N))下的灌溉制度优化模型研究,提出适应不同生育期降水年型的稳产-控污-提效灌溉制度。【结果】(1)与常规灌溉相比,Y-TNP灌溉制度优化水稻产量下降2.14%,氮磷流失量减少23.09%;Y-N灌溉制度优化水稻产量下降1.76%,灌水次数减少53%;Y-TNP-N灌溉制度优化水稻产量下降2.64%,氮磷流失量减少22.83%,灌水次数减少2次。(2)不同典型年以Y-TNP-N为目标优化的稳产-控污-提效灌溉制度水稻产量介于7.74~7.78 t/hm^(2),同时大幅度减少灌水量进而降低氮磷流失量。【结论】AquaCrop模型可模拟试验区水稻的生长发育过程,本文构建的模拟-优化耦合模型可用于优化不同生育期降水年型下稳产-控污-提效的灌溉制度。

【Objective】In order to optimize the irrigation schedule for rice,conserve irrigation water,reduce nitrogen and phosphorus loss in paddy fields,and minimize the risk of non-point source pollution.【Method】A simulation and optimization model for rice irrigation system based on AquaCrop model and NSGA-II algorithm was developed.Field experimental data of rice were used to compare and study the optimization of irrigation systems with three objective combinations:maximizing yield,minimizing nitrogen and phosphorus loss,and minimizing irrigation frequency(Yield-Total Nitrogen and Phosphorus loss(Y-TNP),Yield-Irrigation frequency(Y-N),and Yield-Total Nitrogen and Phosphorus loss-Irrigation frequency(Y-TNP-N)).Yield stable-pollution reducing-efficiency improving irrigation systems that adapt to different precipitation patterns during different growth stages of rice were proposed.【Result】①Compared with conventional irrigation,Y-TNP optimization resulted in a 2.14%decrease in yield and a 23.09%reduction in nitrogen and phosphorus loss;Y-N optimization could achieve a 1.76%decrease in yield and an approximately 53%decrease in irrigation frequency;Y-TNP-N optimization performed a 2.64%decrease in yield,a 22.83%reduction in nitrogen and phosphorus loss and a decrease of 2 in irrigation frequency.②The yield stable-pollution reducing-efficiency improving irrigation system optimized with the Y-TNP-N objective achieved a stable yield of 7.74-7.78 t/hm^(2)under different typical years,significantly reducing irrigation amount and nitrogen and phosphorus loss.【Conclusion】The AquaCrop model can be applied to simulate the growth and development process of rice in the experimental area.The simulation-optimization coupled model proposed in this study can be used to optimize irrigation systems with the goal of stable yield-reducing pollution-improving efficiency under different precipitation patterns during different growth periods.