Abstract: Discussing the flux characteristics of wheat field under disastrous weather background has important scientific significance to understand the occurrence regularity of hazards deeply and to tackle the disasters. Based on observational data of eddy covariance system at Zhengzhou agro-meteorological experimental station, the flux characteristics of wheat field under dry-hot wind weather condition in 2013 and 2017 were analyzed comparatively. The results show that the dry-hot wind weakened photosynthesis capacity of wheat canopy, and the influence of dry-hot wind on flux was obvious in the daytime.  During the day, the CO2 flux of wheat field under different grades of dry-hot wind weather decreased obviously than that in normal weather, it decreased by 33.0% to 59.7% averagely, and the peak value reduced 25.0% to 38.2%. Meanwhile, the peak value appeared ahead of time with various degrees. The effect of dry-hot wind on flux was different in different stages of grouting, and the average CO2 flux decreased most when the hazard occurred in middle stage of grain filling. The net radiation enhanced under dry-hot wind weather condition, the exchange of soil heat flux, latent heat flux and sensible heat flux increased in varying degree, and the peak value of energy flux decreased under severe dry-hot wind weather, light dry-hot wind weather and normal weather condition in turn. The allocation of available energy varied obviously under dry-hot wind weather condition, the value of evaporation ratio was biggest under severe dry-hot wind weather, followed by light dry-hot wind weather and normal weather, meanwhile, the peak value under light dry-hot wind weather occurred backward obviously.

Key words: winter wheat, dry-hot wind, CO2 flux, eddy covariance system, evaporation ratio

摘要： 探讨灾害性天气背景下麦田的通量特征，对深入认识灾害发生规律及应对灾害具有重要的科学意义。利用郑州农业气象试验站涡度相关系统观测资料，分析了2013年和2017年干热风天气下麦田通量特征。结果表明：干热风削弱了小麦群体光合作用能力，且对麦田通量的影响白天最明显。白天，不同程度干热风影响下麦田CO2通量较正常天气明显减少，平均减少33.0%~59.7%，峰值减小25.0%~38.2%，且峰值出现时间有不同程度的提前。灌浆不同时期干热风对麦田通量的影响程度不同，灌浆中期麦田CO2通量平均值减小最多。干热风天气下净辐射增强，使得土壤热通量、潜热通量和感热通量不同程度增加，能量通量的峰值整体自重度干热风天气、轻度干热风天气、正常天气依次减小。干热风天气使麦田可供能量的分配发生明显变化，蒸发比自重度干热风天气、轻度干热风天气、正常天气依次减小，且轻度干热风天气蒸发比峰值明显后移。

关键词: 冬小麦, 干热风, CO2通量, 涡度相关系统, 蒸发比