基于热惯量的土壤湿度估算研究  

Research on Estimating Soil Moisture by Using Thermal Inertia

作　　者：米素娟 吴青柏 沈兵[1,3] 杨增顺 MI Sujuan;WU Qingbo;SHEN Bing;YANG Zengshun(China Transport Telecommunications&Information Center,Beijing 100011,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;China Transinfo Tech Co.,Ltd.,Beijing 100007,China;Beijing Aerospace Measurement&Control Technology Co.,Ltd.,Beijing 100041,China)

机构地区：[1]中国交通通信信息中心,北京100011 [2]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [3]中交信有限责任公司,北京100007 [4]北京航天测控技术有限公司,北京100041

出　　处：《测绘与空间地理信息》2019年第10期11-14,18,共5页Geomatics & Spatial Information Technology

基　　金：科技部国家重点研发计划地球观测与导航项目(2017YFB0503803)资助

摘　　要：冻土受冻土层上水和地表水等因素的影响,出现不均匀、不对称变形。因此,开展冻土区土壤水分的监测研究具有重要意义。本文提出了归一化相对湿度的概念,首先利用晴天风速较小的上午时刻的地表温差估算地表的简化热惯量,再利用日最高地表温度和最低地表温度得到归一化相对湿度。实验证明,本方法提供了一种估算土壤湿度的方法,但是为了得到更深层(大于40 cm)的土壤湿度,需要开展进一步的研究。Frozen soils under subgrade affected by the water in the surface and upper the frozen soil,cause inhomogeneous and asymmetric surface deformation of subgrade.Therefore,it is significant to estimating surface soil moisture and deep soil water in permafrost regions.In order to estimate soil moisture,this paper proposed a method named normalization relative moisture,which was calculated by the simplified thermal inertia.Specifically,the simplified thermal inertia were estimated firstly by surface temperature differences from the time when net radiations were equal to zero to the time for MODIS transit.Secondly,the normalization relative moistures can be obtained by normalizing the biggest daily surface temperatures and smallest daily temperatures.The normalization relative soil moisture can be used to estimate soil moisture beyond 40 cm.Longer time interval will be used in estimating deep soil moisture in the future.

关 键 词：简化热惯量 归一化相对湿度 冻土区 深层土壤湿度 地表温度 

分 类 号：P258[天文地球—测绘科学与技术]