宇宙射线中子法土壤水分监测在不同生态系统雨季的适用性  

Suitability of Cosmic Ray Neutron Probe for Soil Moisture in Different Ecosystems During Rainy Season

作　　者：石耀辉 王海龙 朱永超 吴东丽[1] 丁明明 勾秋磊 侯飙[4] 张全军 刘聪[1] 杨大生[1] 张静[1] SHI Yaohui;WANG Hailong;ZHU Yongchao;WU Dongli;DING Mingming;GOU Qiulei;HOU Biao;ZHANG Quanjun;LIU Cong;YANG Dasheng;ZHANG Jing(Meteorological Observation Center of CMA,Beijing 100081;Beijing Meteorological Observation Centre,Beijing 100176;Wanquan District Meteorological Service,Hebei,Zhangjiakou 076250;Heilongjiang Meteorological Data Center,Harbin 150030)

机构地区：[1]中国气象局气象探测中心,北京100081 [2]北京市气象探测中心,北京100176 [3]河北省张家口市万全区气象局,张家口076250 [4]黑龙江省气象数据中心,哈尔滨150030

出　　处：《气象科技》2024年第1期1-9,共9页Meteorological Science and Technology

基　　金：中国气象局气象探测中心科技成果优化项目(MOCYH202203);北京象元气象观测技术研究院科技创新发展专项(XYKJFZ202107)资助。

摘　　要：宇宙射线中子法是目前测量中尺度土壤水分的一种新兴方法,通过监测近地表附近中子的数量来监测土壤含水率,理论探测深度12~76 cm。为了评估宇宙射线中子法土壤水分监测在草地、农田和林地3种不同生态系统测量深度适用性和对降水的敏感性。本研究分析了中国气象局自动土壤水分站观测数据和遥感土壤水分监测数据与宇宙射线中子法土壤水分监测数据差异性和相关性。结果显示,宇宙射线中子法土壤水分监测草地0~20 cm效果最优,农田和林地0~30 cm最优;在农田和林地生态系统土壤水分监测结果与自动土壤水分站点差异较小,优于遥感监测;但对于草地生态系统,宇宙射线中子法土壤水分监测结果与遥感监测结果差异比单点自动土壤水分站点监测更小,可能与草地土壤的强异质性有关。宇宙射线中子法土壤水分监测在草地、农田和林地生态系统均可以敏感的响应降水事件,较点尺度自动土壤水分站更易捕捉到区域水分的波动性变化。Accurate measurement of soil moisture is key for research in multiple disciplines such as meteorology,ecology,hydrology,agriculture,etc.Soil moisture holds important application value in flood forecasting,drought warning,ecological restoration,irrigation management,and soil erosion prevention and control.Currently,soil water monitoring mainly focuses on the point scale(within 1 m 2)and remote sensing large-scale(research units usually exceed 100 m 2).It is necessary to develop soil moisture monitoring technologies that can accurately measure soil moisture content on a small scale and connect with larger-scale soil moisture monitoring technologies such as remote sensing.The Cosmic Ray Neutron Probe(CRNP)is a new method for measuring soil moisture by monitoring the number of neutrons near the Earth’s surface;the measuring radius in the horizontal direction of the CRNP is 130-240 m depending on air humidity etc.The theoretical detection depth of the CRNP is about 12-76 cm.To evaluate the applicability of the CRNP for soil moisture monitoring in different ecosystems,this study,based on the data from the automatic soil moisture stations of the China Meteorological Administration measured by Frequency Domain Reflectometry(FDR),explores the depth of soil moisture monitored by the CRNP in three different ecosystems such as grassland,farmland and woodland during the rainy season(June to September).The results show that the effect monitored by the CRNP in grassland in 0-20 cm is the best,and that for farmland and woodland in 0-30 cm is the best.Compared with soil moisture data monitored by the SMAP(Soil Moisture Active and Passive)satellite remote sensing,the results of soil moisture measurement in farmland and forest ecosystems by the CRNP are less different from those of the FDR;however,for grassland ecosystems,the difference between the results of CRNP and remote sensing monitoring is smaller than that of the FDR,which may be related to the strong heterogeneity of grassland soil.After the occurrence of precipitation e

关 键 词：宇宙射线中子法 土壤水分 降水 测量深度 适用性 

分 类 号：P412.13[天文地球—大气科学及气象学] P414.8