基于WOFOST-SHAW耦合模型的冬小麦冠层气温模拟

摘要

Air temperature within canopy reflects the growing condition of plants objectively.Simulation of air temperature within canopy can assist in better understanding of microclimate dynamic change characteristics,and can also provide a scientific basis for monitoring late frost injury of winter wheat.A field experiment was conducted in Shangqiu City,Henan Province to observe the winter wheat growth and ambient environmental factors.Based on the localization,coupled WOFOST and SHAW models were applied to simulate dynamic characteristics of air temperature hourly within winter wheat canopy from 0 cm to 80 cm at after-jointing stage in 2016,and the simulation results were compared with measured data.The results suggested that for coupled WOFOST and SHAW models,model efficiency of the simulated and measured values at different heights within winter wheat canopy was greater than 0.90,and over 75％ of absolute errors of simulated values were in the range of-1.5 ～2.5℃,showing a high accuracy in simulating air temperature within winter wheat canopy as a whole.For daily lowest values of air temperature within winter wheat canopy,model efficiency of coupled WOFOST and SHAW models was about 0.86,and the simulation values of daily lowest values of air temperature within winter wheat canopy were 0.53℃ greater than measured values,showing an excellent conformity between simulated and measured values.And the simulation values could precisely reflect daily lowest values of air temperature below 0℃ within winter wheat canopy where the late frost injury occurred easily.Therefore,coupled WOFOST and SHAW models can simulate air temperature within winter wheat canopy well,increase applicability of SHAW model,and provide a reference for monitoring late frost injury.%以河南省商丘地区为研究区域,在田间实验的基础上,对WOFOST模型和SHAW模型进行本地化标定,利用WOFOST-SHAW模型模拟2016年冬小麦拔节期-成熟期冠层0～ 80 cm高度每小时气温的变化特征,并将其模拟结果与实测数据进行对比.结果表明,利用WOFOST-SHAW模型模拟的冬小麦冠层,除了80 cm高度,气温的模型效率均大于0.90,超过75％的模拟气温的绝对误差在-1.5 ～2.5℃之间,说明冠层气温的整体模拟精度较高.WOFOST-SHAW模型对冬小麦冠层各高度的日最低气温的模型效率平均值为0.86,日最低气温模拟值偏高0.53℃,说明冠层日最低气温的模拟值与实测值吻合度较高.同时冬小麦易受冻高度层模拟气温能准确地反映0℃以下的冠层日最低气温,因此,WOFOST-SHAW模型可以很好地模拟冠层气温,提升SHAW模型的适用性,可为冬小麦晚霜冻害的监测提供参考依据.