DOI: 10.5194/hess-20-1373-2016
Scopus记录号: 2-s2.0-84966430614
论文题名: Estimating field-scale root zone soil moisture using the cosmic-ray neutron probe
作者: Peterson A ; M ; , Helgason W ; D ; , Ireson A ; M
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2016
卷: 20, 期: 4 起始页码: 1373
结束页码: 1385
语种: 英语
Scopus关键词: Agriculture
; Cosmic ray measurement
; Cosmology
; Digital storage
; Estimation
; Moisture
; Neutrons
; Probes
; Soil moisture
; Soil surveys
; Soils
; Agricultural management
; Estimation methods
; Exponential filters
; Monitoring approach
; Monitoring locations
; Root zone soil moistures
; Saskatchewan , Canada
; Surface soil moisture
; Cosmic rays
; cosmic ray
; estimation method
; feasibility study
; field method
; filter
; grazing
; monitoring system
; neutron probe
; pasture
; rhizosphere
; soil moisture
; Canada
; Saskatchewan
英文摘要: Many practical hydrological, meteorological, and agricultural management problems require estimates of soil moisture with an areal footprint equivalent to field scale, integrated over the entire root zone. The cosmic-ray neutron probe is a promising instrument to provide field-scale areal coverage, but these observations are shallow and require depth-scaling in order to be considered representative of the entire root zone. A study to identify appropriate depth-scaling techniques was conducted at a grazing pasture site in central Saskatchewan, Canada over a 2-year period. Area-averaged soil moisture was assessed using a cosmic-ray neutron probe. Root zone soil moisture was measured at 21 locations within the 500ĝ€mĝ€ × ĝ€500ĝ€m study area, using a down-hole neutron probe. The cosmic-ray neutron probe was found to provide accurate estimates of field-scale surface soil moisture, but measurements represented less than 40ĝ€% of the seasonal change in root zone storage due to its shallow measurement depth. The root zone estimation methods evaluated were: (a) the coupling of the cosmic-ray neutron probe with a time-stable neutron probe monitoring location, (b) coupling the cosmic-ray neutron probe with a representative landscape unit monitoring approach, and (c) convolution of the cosmic-ray neutron probe measurements with the exponential filter. The time stability method provided the best estimate of root zone soil moisture (RMSEĝ€ Combining double low line ĝ€0.005ĝ€cm3ĝ€cm−3), followed by the exponential filter (RMSEĝ€ Combining double low line ĝ€0.014ĝ€cm3ĝ€cm−3). The landscape unit approach, which required no calibration, had a negative bias but estimated the cumulative change in storage reasonably. The feasibility of applying these methods to field sites without existing instrumentation is discussed. Based upon its observed performance and its minimal data requirements, it is concluded that the exponential filter method has the most potential for estimating root zone soil moisture from cosmic-ray neutron probe data. © Author(s) 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78875
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Civil and Geological Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Global Institute for Water Security, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
Recommended Citation:
Peterson A,M,, Helgason W,et al. Estimating field-scale root zone soil moisture using the cosmic-ray neutron probe[J]. Hydrology and Earth System Sciences,2016-01-01,20(4)