荒漠草原生长季不同时间尺度水热通量变化特征及其影响因子  

Characteristics and impact factors of water and heat flux changes at different time scales during the growing season of desert grasslands

作　　者：韩信 张宝忠[3] 车政 王军[2] 周青云 韩娜娜[1,5] HAN Xin;ZHANG Baozhong;CHE Zheng;WANG Jun;ZHOU Qingyun;HAN Nana(College of Water Conservancy Engineering,Tianjin Agricultural University,Tianjin 300392,China;Yinshanbeilu Grassland Eco-hydrology National Observation and Research Station,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;China Construction Sixth Engineering Bureau Hydropower Construction CO.,LTD.,Tianjin 300222,China;Tianjin Agricultural University-China Agricultural University Joint Smart Water Conservancy Research Center,Tianjin 300392,China)

机构地区：[1]天津农学院水利工程学院,天津300392 [2]中国水利水电科学研究院内蒙古阴山北麓草原生态水文国家野外科学观测研究站,北京100038 [3]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [4]中建六局水利水电建设集团有限公司,天津300222 [5]天津农学院-中国农业大学智慧水利研究中心,天津300392

出　　处：《农业工程学报》2024年第15期65-75,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：中国水利水电科学研究院内蒙古阴山北麓草原生态水文国家野外科学观测研究站开放研究基金项目(YSS202110);国家自然科学基金项目(52130906);中建六局科技研发课题(CSCEC6B-2023-Z-11);中国水利水电科学研究院基本科研业务专项项目(ID0145B022021);天津市主要农作物智能育种重点实验室青年开放基金项目(KLIBMC2303)。

摘　　要：荒漠草原水热通量变化特征及其影响因素分析对提高区域水热交换规律认识和了解其在气候变化中的作用具有重要意义。该研究基于内蒙古荒漠草原2018和2019年4—10月涡度相关系统与相应的环境因子观测资料,分析了荒漠草原不同时间尺度水热通量(感热通量(sensible heat flux,H)和潜热通量(latent heat flux,LE))及能量占比(H/LE)的变化特征及其环境因子调控机制。结果表明:1)H为该生态系统的主要能量消耗形式,且同一环境因子在不同生育期对H、LE、H/LE的影响存在差异;2)小时尺度上,H、LE呈单峰型变化,峰值均主要出现在12:00—14:00之间,且LE峰值出现时间较H滞后1~2 h。H的主要影响因素为平均风速(wind speed,Ws),相对湿度(relative humidity,RH)、饱和水汽压差(vaporpressuredeficit,VPD)和空气温度(airtemperature,Ta),相关系数(correlation coefficient,r)绝对值大小分别为Ws(0.72)>RH(0.66)>VPD(0.61)>Ta(0.38)。LE的主要影响因素为Ta、VPD、地面温度(soil temperature,Ts)和降雨(precipitation,P);3)日尺度上,H、LE呈明显的季节变化,H的主要影响因素是RH、Ws、Ts、Ta、P和VPD,LE主要影响因素为RH、Ws、Ts和Ta;4)月尺度上,H、LE近似呈单峰型变化,夏季能量消散方式以LE为主,H的主要影响因素为RH、Ws和VPD,其中VPD正效应最强(r=0.75),P对LE的正效应最强(r=0.75),而RH对H/LE的负效应最强(r=-0.76)。研究结果有利于准确理解多时间尺度下荒漠草原H和LE对环境因子的响应,同时可为草原生态功能区的植被恢复、生态环境保护提供理论依据和技术支撑。Water and heat flux is a key components for the energy exchange of surface air in atmospheric circulation.The driving mechanism can include the sensible heat flux(H)and latent heat flux(LE).There is a great variation in the water and heat flux in desert grasslands.The influencing factors are of great significance to understanding the regional exchange of water and heat flux against climate change.This study aims to explore the variation patterns of water and heat flux at different time scales.The eddy covariance and continuous observation were also utilized from automatic meteorological stations in Xilamuren Town,Damao Banner,Inner Mongolia,China.After that,the regulatory mechanisms of environmental factors were proposed for the desert grassland during growing seasons(April to October)in 2018 and 2019.A systematic analysis was made on the H,LE,and energy ratio(H/LE)in the desert grasslands at different time scales,together with their environmental control mechanisms.The results indicated that the H of plants was the main form of near-surface energy consumption in the desert grassland during the growth season.There was an unimodal variation in the H and LE on an hourly scale.The H and LE peaks mainly occurred between 12:00 and 14:00,where the time of LE peak occurrence was lagged by 1-2 h,compared with the H.The variation range of H and LE between 8:00—18:00 was 0.1-160.5 and 15.4-90.9 W/m^(2),respectively.The main influencing factors of H were the wind speed(Ws),relative humidity(RH),vapor pressure deficit(VPD)and air temperature(Ta)with the correlation coefficients(r)of 0.72,-0.66,0.61 and 0.38,respectively.The main influencing factors of LE were Ta,VPD,and ground soil temperature(Ts)and precipitation(P),with r of 0.76,0.67,0.61,and 0.37,respectively.The main influencing factors of H/LE were RH,Ws,and VPD,with r values of-0.74,0.86,and 0.24,respectively.There was an outstanding seasonal variation in the H and LE on a daily scale.The maximum is also reached before and after the middle stage of plant growth.The

关 键 词：荒漠草原 不同时间尺度 水热通量 影响因子 

分 类 号：S126[农业科学—农业基础科学]