亚热带草地水热动态变化及地表能量分配  

Hydrothermal Dynamics and Surface Energy Allocation in Subtropical Grasslands

作　　者：王恒 张清涛[1,2,3,4] 王志强 吴昕宇 WANG Heng;ZHANG Qingtao;WANG Zhiqiang;WU Xinyu(School of Civil Engineering,Sun Yat-sen University,Zhuhai 519082,China;Guangdong Engineering Technology Research Center of Water Security Regulation and Control for Southern China,Sun Yat-Sen University,Guangzhou 510275,China;Guangdong Provincial Key Laboratory for Marine Civil Engineering,Sun Yat-sen University,Zhuhai 519082,China;Guangdong Provincial Laboratory of Southern Marine Science and Engineering,Zhuhai 519082,China)

机构地区：[1]中山大学土木工程学院,广东珠海519082 [2]中山大学华南地区水循环与水安全广东省普通高校重点实验室,广东广州510275 [3]广东省海洋土木工程重点实验室,广东珠海519082 [4]南方海洋科学与工程广东省实验室,广东珠海519082

出　　处：《人民珠江》2023年第12期1-12,53,共13页Pearl River

基　　金：国家自然科学基金项目(31270748,31470707);海绵城市建设水系统科学湖北省重点实验室开放基金(武汉大学)(2020-05)。

摘　　要：土壤水热变化是生态水文过程研究中的重要一环,而关于亚热带沿海地区草地土壤水热的研究相对不足。利用实地观测资料对亚热带校园区的草地土壤水热、地表能量平衡进行了研究,结果表明:①草地土壤水分在干湿季受降雨影响不同,降雨在干季引起的土壤水分变化会比湿季更大,研究期内12月20日,日降雨量为15.2 mm,土壤水分变化为0.12 m^(3)/m^(3),5月1日时日降水量为120.3 mm,土壤水分变化仅为0.11 m^(3)/m^(3);②在土壤水势梯度垂向变化上,湿季土壤水势梯度零通面出现在10~30 cm内,干季土壤水势梯度零通面出现在50 cm左右;③根据土壤水分对降雨的响应,干湿季节降雨后土壤水分运移主要发生在0~40 cm土壤深度;④土壤温度的变化受季节气温影响大,表层土壤温度梯度大,春夏季节,土壤温度随土壤深度的增加而减少,秋冬季节,土壤温度随土壤深度的增加而增加;⑤相邻2个月内,湿季草地蒸腾相对于干季明显减少,在能量分配上,湿季虽然降雨多,能量通量少,但是潜热通量的占比却反而升高,0:00—6:00、7:00—17:00的潜热通量比例分别比干季提升了3%和7%。研究了亚热带草地水热动态及地表能量的降雨、季节差异,为亚热带沿海区域生态系统研究提供资料。Soil hydrothermal changes are an important part of the study of eco-hydrological processes,and studies on soil hydrothermal changes in grasslands in subtropical coastal areas are relatively insufficient.This paper studied the soil hydrothermal changes and surface energy balance of grassland in a subtropical campus area by using field observation data.The results showed that:①Grassland soil moisture is affected differently by rainfall in the wet and dry seasons,with rainfall causing greater soil moisture changes in the dry season than in the wet season.On 20 December,the daily rainfall was 15.2 mm,and the soil moisture change was 0.12 m^(3)/m^(3)during the study period.On 1 May,the daily rainfall was 120.3 mm,and the soil moisture change was only 0.11 m^(3)/m^(3).②In terms of vertical variation in soil water potential gradient,the zero-pass surface of the soil water potential gradient occurs within 10~30 cm in the wet season and around 50 cm in the dry season.③According to the response of soil moisture to rainfall,soil moisture transport after rainfall in the dry and wet seasons mainly occurs at a soil depth of 0~40 cm.④The change in soil temperature is greatly influenced by seasonal temperature,and the surface soil temperature gradient is large.In spring and summer,soil temperature decreases with increasing soil depth;in autumn and winter,soil temperature increases with increasing soil depth.⑤Within two adjacent months,transpiration from grasses is significantly reduced in the wet season relative to the dry season.In terms of energy allocation,although the wet season sees more rainfall and less energy flux,the proportion of latent heat flux is higher,with the proportion of latent heat flux between 0:00 and 6:00 and between 7:00 and 17:00 increasing by 3%and 7%respectively compared with the dry season.This paper examines rainfall and seasonal differences in the hydrothermal dynamics and surface energy of subtropical grasslands,providing information for the study of ecosystems in subtropical coastal zones

关 键 词：土壤水势 土壤温度 地表能量 降雨 

分 类 号：TV21[水利工程—水文学及水资源]