亚热带湿润区农业用地热环境效应及其生物物理因子分析

为分析亚热带湿润区农业用地对区域气候的影响，以江西省为例，基于2003—2019年的MODIS地表温度数据，将天然林地作为参照，分析了亚热带湿润地区农业用地热环境效应的时空变化特征及其与主要生物物理因子的关系。结果表明:(1)与天然林地相比，农业用地在白天具有明显的增温效应，年均增温幅度达1.9 ℃；夜间降温效应明显。(2)农业用地热环境效应随季节变化明显，特别是在夜晚，主要表现为农业用地在夏季的夜晚具有微弱的增温效应。(3)2003—2019年，农业用地白天增温和夜晚降温效应均呈增加态势。(4)农业用地热环境效应在白天主要受蒸散的控制，在夜晚主要受蒸散和反照率的共同控制。

Analysis on the Thermal Environment Effects and Their Biophysical Factors of Agricultural Lands in Humid Subtropical Regions

To analyze the influence of agricultural land in subtropical humid zone on regional climate, the spatial and temporal variation characteristics of the thermal environmental effect of agricultural land in subtropical humid zone and its relationship with the main biophysical factors were analyzed in Jiangxi Province, based on MODIS surface temperature data from 2003 to 2019, with natural forest land as a reference. Results show: (1) agricultural lands warm the land surface significantly relativity to natural forests during the day, with annual mean temperature increase of 1.9 ℃, whereas cool the temperature substantially at night; (2) the thermal environment effects of agricultural lands vary greatly by the season, especially at night, characterized by weak nighttime warming effects du-ring summer; (3) both the daytime warming and nighttime cooling effects of agricultural lands show upward trends from 2003 to 2019; (4) the thermal environment effects of agricultural lands are primarily controlled by evapotranspiration during the day and by the joint control of evapotranspiration and surface albedo at night.