宁夏中部干旱带露水形成机制及其对表层土壤水分的影响  

The mechanisms of dew formation and its influence on surface soil water content in the Central Ningxia arid belt

作　　者：马波[1,2] 田军仓 何进宇[1,3] 王智 MA Bo;TIAN Juncang;HE Jinyu;WANG Zhi(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Engineering Technology Research Center of Water Saving and Water Resource Regulation in Ningxia,Yinchuan 750021,China;Engineering Research Center for Efficient Utilization of Modern Agricultural Water Resources in Arid Regions,Ministry of Education,Yinchuan 750021,China;Department of Earth and Environmental Sciences,California State University,Fresno 93740,USA)

机构地区：[1]宁夏大学土木与水利工程学院,宁夏银川750021 [2]宁夏节水灌溉与水资源调控工程技术研究中心,宁夏银川750021 [3]旱区现代农业水资源高效利用教育部工程研究中心,宁夏银川750021 [4]Department of Earth and Environmental Sciences,California State University,Fresno 93740,USA

出　　处：《水科学进展》2022年第6期955-966,共12页Advances in Water Science

基　　金：国家自然科学基金资助项目(51869024);宁夏重点研发计划资助项目(2019BEH03010)。

摘　　要：露水的形成及其对土壤水分的影响是进一步量化水循环和生态水文过程的重要依据。为探明露水发生规律,在宁夏中部干旱带连续3 a观测了每30 min气象资料和表层土壤水分,用叶片湿度传感器测算了露水量。结果表明:该区年露水量可达56.41 mm,75%发生在6—10月,最大月露水量和日露水量分别为13.40 mm和0.80 mm,主要发生在03:00—08:00;露水发生的气温、相对湿度和风速范围分别为0~24.4℃、50%~100%和0.16~1.74 m/s,风向为30°~60°(东北风)和270°~330°(西南偏西风);气温和露点差与相对湿度之间呈极显著线性逆相关,气温和露点差小于3℃且相对湿度大于80%时极易产生露水;日露水量为0.6 mm、0.7 mm和0.8 mm时表层5 cm土壤贮水量可分别提高0.10 mm、0.20 mm和0.25 mm。该地区年均降露量是降雨量的13.5%,露水年均发生频率为126 d(35%),是当地水循环和生态系统不可忽略的水源。Dew formation and its influence on soil water content are an important basis for next-level quantification of water cycling and eco-hydrological processes.To reveal the dew formation process,over a consecutive 3-year period,we monitored meteorological parameters and soil water content in the top layer at 30-minute recording intervals in the Central Ningxia Province arid belt.The dew amount was measured using a leaf wetness sensor.Annual dew yield in this region reached 56.41 mm,75%of which occurred from June to October.Maximum monthly and maximum daily dew were 13.40 mm and 0.80 mm,respectively,and mainly occurred in the early morning from 03:00 to 08:00 am.Meteorological parameters responsible for dew formation were:air temperature between 0—24.4℃,relative humidity between 50%—100%,wind speed between 0.16—1.74 m/s,and wind direction between 30—60 degrees and 270—330 degrees.There was a very significant and highly correlated linear and inverse relationship between relative humidity and the difference between air temperature and dewpoint.When the difference was<3℃and the corresponding humidity>80%,dew formation was much more likely.When daily dew reached 0.6 mm,0.7 mm and 0.8 mm,soil water storage in the top 5cm soil increased by 0.10 mm,0.20 mm and 0.25 mm,respectively.Annual dewfall was 13.5%of the rainfall,and the annual frequency of dew occurrence was 126 days(35%),indicating that dew is a significant water source for local water and ecosystem cycling.

关 键 词：露水 形成机制 土壤水分 干旱带 

分 类 号：P426[天文地球—大气科学及气象学]