关键词: 表面温度, 涡度相关技术, 农田能量平衡

Abstract: 【Objective】The variation regularity and characteristics of surface temperature in field are important for monitoring soil and crop water status.【Method】Energy flux and surface temperature at field scale were differently measured using the eddy covariance technique and remote sensing in summer maize field in the North China Plain, the effect of energy balance components and air temperature on the diurnal and seasonal variation of surface temperature was analyzed during the whole growth and development period of maize.【Result】The relationship between surface temperature and air temperature in diurnal pattern was remarkable different for the difference of leaf area index (LAI) under no-water stress. It was a good linear correlation between them at 0.01 level under small LAI, but complex during full cover period. Net radiation and latent heat flux were the main energy factors influencing surface temperature, the variation of correlation degree between them showed a parabola curve with LAI increasing and decreasing, and there was a highest correlation between surface temperature and energy balance components during full cover period under clear day(α=0.01). There was a close correlation between average daily surface temperature and average daily air temperature, transient surface temperature and air temperature in the seasonal pattern. The value of the surface-air temperature difference was about -5.3℃ under clear day when the soil water content was above about 65% of field capacity in depth of 0 cm-100 cm.【Conclusion】In conclusion, surface temperature is determined by many factors, such as crop growth potential, radiation and soil water conditions and so on.

Key words: Surface temperature, Eddy covariance technology, Energy balance components