宇宙射线中子法测量区域土壤水分准确性季节变化研究  

Seasonal Variations of Regional Soil Moisture Measurement Accuracy Based on Cosmic-ray Neutron Sensing

作　　者：武强 黄娜 罗孳孳 唐余学 朱玉涵 徐倩倩[4] WU Qiang;HUANG Na;LUO Zizi;TANG Yuxue;ZHU Yuhan;XU Qianqian(Chongqing Institute of Meteorological Sciences,Chongqing 401147,China;Chongqing Jiangjin Modern Agrometeorology Test Station,Chongqing 402260,China;College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193,China;Hefei Meteorological Bureau,Hefei 230041,China)

机构地区：[1]重庆市气象科学研究所,重庆401147 [2]重庆市江津现代农业气象试验站,重庆402260 [3]中国农业大学资源与环境学院,北京100193 [4]合肥市气象局,合肥230041

出　　处：《农业机械学报》2022年第1期321-330,共10页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金面上项目(42175193);中国气象局创新发展专项(CXFZ2021J068、CXFZ2021J073);重庆市技术创新与应用发展专项(cstc2020jscx-msxmX0111);重庆市气象局科技计划项目(QNJJ-201703);重庆市气象部门业务技术攻关项目(YWJSGG-201905);重庆市气象部门智慧气象技术创新团队项目(ZHCXTD-202016)。

摘　　要：为证实典型气象条件下宇宙射线中子法测量区域土壤水分准确性的差异和应用普适性,以季节为时间划分尺度,并选取典型气象条件时段,对比研究山地地形下垫面宇宙射线中子法(CRNS)与频域反射法(FDR)土壤水分连续观测效果差异。结果表明:山地地形下垫面,CRNS水平测量足迹的季节变化较为稳定,垂直足迹在耕作层范围内有一定波动。不同季节降水过程的量级差异是引起CRNS测量结果偏差的主要因素,夏秋两季,在高温少雨导致的持续失墒以及较大量级降水过程等土壤水分变化较为剧烈的时段,CRNS与FDR测量结果一致性较好,春季多为小量级降水,作物冠层截留作用导致二者一致性略差,冬季降水量与蒸散发接近平衡,且单次降水量级极小,CRNS与FDR偏差极小。分析典型土壤水分条件下的CRNS测量准确性变化,进一步明确了降水过程对CRNS准确性的干扰,而在持续高温干旱时段则一致性良好,均方根误差(RMSE)、纳什效率系数(NSE)和Kling-Gupta系数(KGE)分别达到0.014 m^(3)/m^(3)、0.925、0.919。研究可为CRNS的应用场景选取与数据质量控制提供科学依据。The cosmic-ray neutron sensing method is a mesoscale and non-contact method for measuring soil moisture,which has been widely studied and applied.However,whether the accuracy and the applicability of the measurement results was consistent under the influence of typical meteorological conditions have not been clearly confirmed.The seasons were divided into time scales and typical meteorological periods were selected to study the difference of continuous observation effect between cosmic-ray neutron sensing(CRNS)and frequency domain reflection(FDR)under mountainous terrain.The result indicated that the seasonal variation of CRNS horizontal footprint was relatively stable under mountainous terrain,while the vertical footprint was fluctuated within the tillage layer.Different precipitation levels in different seasons was the main factor causing CRNS measurement deviation,during the period of severe soil moisture change,such as the continuous loss of soil moisture caused by high temperature and little rain and the process of precipitation of larger magnitude in summer and autumn,the results of CRNS and FDR were consistent.The spring precipitation was also smaller magnitude,canopy interception results in slightly different consistency between CRNS and FDR.In winter,precipitation and evapotranspiration were basically balanced,and the single precipitation was smaller magnitude,CRNS and FDR had a minimal deviation.The variation of CRNS measurement accuracy under typical soil moisture conditions was analyzed to further explain the influence of precipitation on the accuracy of CRNS,while the consistency was good in the period of continuous high temperature and drought,the root mean square error(RMSE),Nash Sutcliffe efficiency coefficient(NSE)and Kling-Gupta efficiency coefficient(KGE)was 0.014 m^(3)/m^(3),0.925 and 0.919,respectively.The research results can provide a scientific basis for the selection of application scenarios and data quality control of CRNS.

关 键 词：土壤水分 测量准确性 季节变化 宇宙射线中子法 

分 类 号：S163[农业科学—农业气象学]