WU Qiang,XU Qianqian,ZHU Yuhan,et al.Improving Calibration and Validation of Soil Moisture Measurements Using Cosmic-Ray Neutron Method Based on Linear Depth Weighting[J].Research of Soil and Water Conservation,2021,28(04):113-120.
基于垂直足迹线性加权算法的宇宙射线中子法土壤水分测量校准与验证
- Title:
- Improving Calibration and Validation of Soil Moisture Measurements Using Cosmic-Ray Neutron Method Based on Linear Depth Weighting
- 文章编号:
- 1005-3409(2021)04-0113-08
- Keywords:
- cosmic-ray neutron method; linear depth weighting; footprint equal weighting; soil moisture
- 分类号:
- S163;S152.7
- 文献标志码:
- A
- 摘要:
- 为了研究宇宙射线中子法的不同测量足迹模拟对土壤水分反演结果准确性的影响,以烘干称重法为标准对比,频域反射法为趋势稳定性对照,基于垂直足迹线性加权方法对宇宙射线中子法反演区域土壤水分进行参数校准与测量结果验证,比较了相对于测量足迹等权重加权方法的区域土壤水分反演准确性。结果表明:相较于测量足迹等权重加权方法,垂直足迹线性加权处理的宇宙射线中子法区域土壤水分反演结果与通过烘干称重法获得的标准值一致性更好,反演模型准确性提高,与烘干称重法多点平均所代表的区域土壤水分值进行拟合,决定系数R2增加0.036,均方根误差RMSE减小0.002 3 kg/kg,纳什效率系数NSE提高0.041; 与频域反射法连续性测量结果比较,研究宇宙射线中子法连续性测量结果稳定性,结果显示除降水时段外,利用等权重加权与垂直足迹线性加权算法的结果趋势具有相似的一致性; 垂直足迹线性权重配比更符合不同深度土壤水分在宇宙射线中子法反演计算区域土壤水分的贡献差异,基于垂直足迹线性加权的宇宙射线中子法区域土壤水分反演结果能够更加客观地反映测量足迹内土壤水分的实际情况。
- Abstract:
- In order to study the influence of different footprint simulation of cosmic-ray neutron method on the accuracy of soil moisture inversion results, and the optimization effect relative to the footprint equal weighting method, the parameter calibration and result validation of soil moisture inversion by the cosmic-ray neutron method based on the linear depth weighting method, as the oven-drying method being the standard comparison, while the frequency domain reflection method being the continuous comparison. The accuracy of measurement results was compared with the standard value represented by the oven-drying method, the determination coefficient of linear equation(R2)increased by 0.036, the root-mean-square error(RMSE)decreased by 0.002 3 kg/kg, the Nash-Sutcliffe efficiency coefficient(NSE)increased by 0.041, the consistency of measurement results was better and the accuracy of inversion model was improved. The results of continuous measurement were compared with the frequency domain reflection method, the results showed no significant difference in trend stability between the two methods except the precipitation period. This study indicated that the inversion result based on the linear depth weighting method in improved consistency and accuracy of inversion model as the standard value obtained by oven-drying method, and the stability was close to the results of frequency domain reflection method in continuous observation compared with the footprint equal weighting method. The linear depth weighting was more consistent with the contribution of soil moisture in different depth. The soil moisture inversion by the cosmic-ray neutron method based on the linear depth weighting method can reflect the actual situation of soil moisture in the footprint more objectively.
参考文献/References:
[1] Vereecken H, Huisman J A, Bogena H, et al. On the value of soil moisture measurements in vadose zone hydrology: A review[J]. Water Resources Research, 2008,44(4):1-21.[2] Robinson D A, Campbell C S, Hopmans J W, et al. Soil moisture measurement for ecological and hydrological watershed-scale observatories: A Review[J]. Vadose Zone Journal, 2008,7(1):358-389.[3] 霍治国,范雨娴,杨建莹,等.中国农业洪涝灾害研究进展[J].应用气象学报,2017,28(6):641-653.[4] Norbiato D, Borga M, Esposti S D, et al. Flash flood warning based on rainfall thresholds and soil moisture conditions: An assessment for gauged and ungauged basins[J]. Journal of Hydrology, 2008,362(3/4):274-290.[5] 王晓宁,岳大鹏,赵景波,等.黑龙江省1958—2017年极端降水时空变化与灾害效应[J].水土保持研究,2020,27(5):138-146.[6] 宋春雨,韩晓增,于莉,等.CROPWAT模型在调亏灌溉研究中的应用[J].土壤与作物,2003,19(3):214-217.[7] 郑金涛,彭涛,董晓华,等.三峡库区气象干旱演变特征及致灾因子危险性评价[J].水土保持研究,2020,27(5):213-220.[8] 郑越馨,吴燕锋,潘小宁,等.三江平原气象水文干旱演变特征[J].水土保持研究,2019,26(4):177-184,189.[9] Almeida A C, Dutta R, Franz T E, et al. Combining cosmic-ray neutron and capacitance sensors and fuzzy inference to spatially quantify soil moisture distribution[J]. Sensors Journal Ieee, 2014,14(10):3465-3472.[10] Coopersmith E J, Cosh M H, Daughtry C S. Field-scale moisture estimates using COSMOS sensors: A validation study with temporary networks and Leaf-Area-Indices[J]. Journal of Hydrology, 2014,519:637-643.[11] Hawdon A, Mcjannet D, Wallace J. Calibration and correction procedures for cosmic-ray neutron soil moisture probes located across Australia[J]. Water Resources Research, 2014,50(6):5029-5043.[12] 宋尚琨,田静,何洪林.宇宙射线快中子法在华北平原典型农田土壤水分测量中的应用[J].应用生态学报,2018,29(9):2915-2924.[13] 贾晓俊,施生锦,黄彬香,等.宇宙射线中子法测量土壤水分的原理及应用[J].中国农学通报,2014,30(21):113-117.[14] 赵纯,袁国富,刘晓,等.宇宙射线土壤水分观测方法在黄土高原草地植被的应用[J].土壤学报,2015,52(6):1438-1444.[15] 武强,贺开利,罗孳孳,等.宇宙射线中子法在复杂下垫面土壤水分测量中的应用[J].中国农业气象,2020,41(1):34-42.[16] Zreda M, Desilets D, Ferré T P A, et al. Measuring soil moisture content non-invasively at intermediate spatial scale using cosmic-ray neutrons[J]. Geophysical Research Letters, 2008,35(21).DOI: 10.1029/2008GL035655.[17] Franz T E, Zreda M, Ferré T P A, et al. Measurement depth of the cosmic ray soil moisture probe affected by hydrogen from various sources[J]. Water Resources Research, 2012,48(8).DOI: 10.1029/2012WR011871.[18] Köhli M, Schrön M, Zreda M, et al. Footprint characteristics revised for field-scale soil moisture monitoring with cosmic-ray neutrons[J]. Water Resources Research, 2015,51(7):5772-5790.[19] Franz T E, Zreda M, Ferré T P A, et al. An assessment of the effect of horizontal soil moisture heterogeneity on the area-average measurement of cosmic-ray neutrons[J]. Water Resources Research, 2013,49(10):6450-6458.[20] Bogena H R, Huisman J A, Baatz R, et al. Accuracy of the cosmic-ray soil water content probe in humid forest ecosystems: The worst case scenario[J]. Water Resources Research, 2013,49(9):5778-5791.[21] Franz T E, Zreda M, Rosolem R, et al. Feld validation of a cosmic-ray neutron sensor using a distributed sensor network[J]. Vadose Zone Journal, 2012,11(4).DOI:10.2136/vzj2012.0046.[22] Schrön M, Köhli M, Scheiffele L, et al. Improving calibration and validation of cosmic-ray neutron sensors in the light of spatial sensitivity[J]. Hydrology and Earth System Sciences, 2017,21(10):5009-5030.[23] Zreda M, Shuttleworth W J, Zeng X, et al. COSMOS: The cosmic-ray soil moisture observing system[J]. Hydrology and Earth System Sciences, 2012,16(11):4079-4099.[24] Rosolem R, Shuttleworth W J, Zreda M, et al. The effect of atmospheric water vapor on the cosmic-ray soil moisture signal[J]. Urban History Review Revue Dhistoire Urbaine, 2013,10(14):1659-1671.[25] Desilets D, Zreda M, Ferré T P A, et al. Nature's neutron probe: Land surface hydrology at an elusive scale with cosmic rays[J]. Water Resources Research, 2010,46(11).DOI: 10.1029/2009WR008726.[26] Desilets D, Zreda M, Prabu T. Extended scaling factors for in situ cosmogenic nuclides: New measurements at low latitude[J]. Earth and Planetary Science Letters, 2006,246(3/4):265-276.[27] Desilets D, Zreda M. Spatial and temporal distribution of secondary cosmic-ray nucleon intensities and applications to in situ cosmogenic dating[J]. Earth and Planetary Science Letters, 2003,206(1/2):21-42.[28] Desilets D M. Cosmogenic Nuclides as A Surface Exposure Dating Tool: Improved Altitude/Latitude Scaling Factors For Production Rates[D]. Arizona, USA: The University of Arizona, 2005.[29] 赵华甫,高鹏,范树印.基于线性规划的耕作层土壤剥离利用空间配置方法研究[J].农业机械学报,2018,49(6):176-183.[30] Duygu M B, Akyürek Z. Using cosmic-ray neutron probes in validating satellite soil moisture products and land surface models[J]. Water,2019,11(7).DOI:10.3390/w11071362.[31] Montzk C, Bogena H, Zreda M, et al. Validation of spaceborne and modelled surface soil moisture products with Cosmic-Ray Neutron Probes[J]. Remote Sensing, 2017,9(2).DOI:10.3390/rs9020103.[32] Franz T E, Zreda M, Rosolem R, et al. A universal calibration function for determination of soil moisture with cosmic-ray neutrons[J]. Hydrology and Earth System Sciences, 2013,17(9):453-460.
备注/Memo
收稿日期:2020-08-20 修回日期:2020-09-13资助项目: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面上项目(cstc2020jscx-msxmX0111); 重庆市气象部门智慧气象技术创新团队项目(ZHCXTD-202016); 重庆市气象部门业务技术攻关项目(YWJSGG-201905); 重庆市气象局科技计划项目(QNJJ-201703)第一作者:武强(1989—),男,山西河曲人,工程师,主要从事农田小气候和气象仪器研究。E-mail:theodorus@yeah.net通信作者:罗孳孳(1980—),男,重庆北碚人,高级工程师,主要从事农业气象研究。E-mail:showerluo@163.com