长江源区典型流域冻土温湿度变化特征及其影响因素分析  

Analysis on the Temperature and Moisture of Frozen Soil in the Typical Watershed of Yangtze River Source Area and Its Influencing Factors

作　　者：常福宣[1] 覃自成 程卫帅[1] 何晓波 CHANG Fuxuan;QIN Zicheng;CHENG Weishuai;HE Xiaobo(Changjiang River Scientific Research Institute of Changjinag Water Resources Commission,Wuhan 430010,China;Liuzhou Longxi Water Conservancy and Hydropower Construction Investment Co.Ltd.,Liuzhou 545000,China;State Key Laboretory of Cryospheric,Northwest Institute of Eco-Environment and Resources,Lanzhou 730000,China)

机构地区：[1]长江水利委员会长江科学院,湖北武汉430010 [2]柳州市龙溪水利水电建设投资有限公司,广西柳州545000 [3]中国科学院西北生态环境资源研究院冰冻圈科学国家重点实验室,甘肃兰州730000

出　　处：《水文》2021年第4期62-68,共7页Journal of China Hydrology

基　　金：国家重点研发计划资助项目“湿润半湿润区雨洪可利用性评价理论与方法”(2016YFC0400901)。

摘　　要：利用长江源区典型流域观测数据,对冻土温度和湿度进行分析,结果表明土壤温湿度随埋深表现出不同的变化特征。浅层土温对气温响应快,时间上有明显昼夜变化,空间上向下传导有一定的滞后效应,垂向传导速率为3~4h/10cm;深层土温与气温相关性较弱。气温对土壤湿度的影响主要在于土温变化影响冻土冻融过程,在冻融期土壤湿度变化迅速。降水和蒸散发主要影响表层土壤以及下渗过程。分析发现在40~50cm左右有明显分层,上层土壤在暖季由于冻土溶解加上降雨增大水分迅速饱和成为饱和带,饱和湿度为0.4;下层则为非饱和带;而40cm正是当地植被根系的深度。在全球气候变化背景下,气温升高将引起土壤温度升高,冻土溶解期变长,从而引起流域水循环发生变化,对流域植被和生态环境也会产生影响。This paper analyzed the temperature and moisture of frozen soil in the typical basin of Yangtze River source area based on its observation data.The results show that the temperature of the shallow soils responds to the air temperature quickly,and delays about 3-4 h/10 cm in the vertical direction;the temperature of deep soil has weak correlation to the air temperature.The soil moisture changes rapidly during the freezing and melting period.The precipitation and evapotranspiration mainly affect the moisture of surface soil and infiltration process.There is an obvious stratification at 40-50 cm underground,the upper soils become saturated zone rapidly in warm season because of the dissolved water of frozen soil and the increase of precipitation,and the lower layers are unsaturated zone,the saturated water contents of upper soils are all equate to 0.4.Under the background of global climate change,the increase of temperature would cause the rise of soil temperature,and the dissolution period of frozen soil become longer.The hydrology cycle and vegetation of the watershed would change,which would impact the water resources and ecological environment of the area.

关 键 词：长江源区 冻土 土壤温度 土壤湿度 气候变化 

分 类 号：TV121[水利工程—水文学及水资源]