祁连山草地坡面土壤水时空动态及时间稳定性  

Spatiotemporal Dynamics and Temporal Stability of Soil Moisture on Grassland Slopes in Qilian Mountains

作　　者：刘源 田杰 王水献[1] LIU Yuan;TIAN Jie;WANG Shuixian(College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,Gansu,China;Center for Dryland Water Resources Research and Watershed Science,Ministry of Education Key Laboratory of West China’s Environmental System,College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,Gansu,China)

机构地区：[1]兰州大学资源环境学院,甘肃兰州730000 [2]兰州大学资源环境学院西部环境教育部重点实验室,旱区流域科学与水资源研究中心,甘肃兰州730000

出　　处：《高原气象》2024年第5期1249-1258,共10页Plateau Meteorology

基　　金：国家自然科学基金重点项目(42030501);国家自然科学基金青年科学基金项目(42101022);甘肃省水利重点科研计划项目(22GSLK057)。

摘　　要：土壤水分作为连接地表与大气水热交换的关键水文变量,影响陆-气水热交换和碳循环过程。但由于高寒山区土壤水分监测困难,相关研究存在一定困难。而时间稳定性研究能够通过选择代表性点位从而降低土壤水分获取难度。本研究选取祁连山区石羊河流域上帐房沟草地坡面,组建高密度、高时间分辨率土壤水分监测网,探讨高寒山区坡面尺度土壤水分时空变化及时间稳定性。研究结果表明:(1)表层土壤水分(10 cm,15.90%)显著高于深层(50 cm,11.78%),其时间变异性(CvT=19.46%)也强于深层(CvT=10.67%),但空间变异性(CvS=20.05%)弱于深层(CvS=27.06%)。(2)表层时间稳定性指数(Index ofTemporal Stability,ITS)(0.24)强于深层(0.34),表层和深层分别通过3个或5个土壤水分监测点即可代表坡面表层土壤水分(决定系数R2>0.90)。(3)坡位和土壤水文属性对时间稳定性的作用效果显著:时间稳定性点位更容易出现在坡下容重较大、形状参数n较小的位置。研究结果有助于更好理解高寒山区坡面土壤水分时空变异规律、时间稳定性特征及其控制作用。Soil moisture,as a key hydrological variable connecting the surface and atmospheric water and heat exchange,affects the land-air water and heat exchange and carbon cycle process.However,due to the difficulty in monitoring soil moisture in alpine mountain areas,there are some difficulties in related research.The study of time stability can reduce the difficulty of soil moisture acquisition by selecting representative points.In this study,the slope of Shangzhangfanggou grassland in Shiyang River basin of Qilian Mountain was selected to set up a high-density and high-time resolution soil moisture monitoring network to explore the temporal and spatial variation and temporal stability of soil moisture on the slope scale in alpine mountainous areas.The research results show that:(1)The surface soil moisture(10 cm,15.90%)is significantly higher than that in the deep layer(50 cm,11.78%),and its temporal variability(CvT=19.46%)is also stronger than that in the deep layer(CvT=10.67%),but its spatial variability(CvS=20.05%)is weaker than that in the deep layer(CvS=27.06%).(2)The time stability Index of Temporal Stability(0.24)is stronger than that of the deep layer(0.34),and the surface layer and the deep layer can represent the surface soil moisture of the slope through 3 or 5 soil moisture monitoring points respectively(R2>0.90).(3)Slope position and soil hydrological properties have obvious influence on time stability,and the time stability point is more likely to appear at the position with larger bulk density and smaller shape parameter n under the slope.The research results are helpful to better understand the temporal and spatial variation law,temporal stability characteristics and control function of soil moisture on slope in alpine mountain areas.

关 键 词：土壤水分 时空动态 时间稳定性 祁连山区 

分 类 号：S152.7[农业科学—土壤学]