This title appears in the Scientific Report :
2022
Please use the identifier:
http://dx.doi.org/10.5194/gi-11-451-2022 in citations.
Please use the identifier: http://hdl.handle.net/2128/33359 in citations.
Feasibility of irrigation monitoring with cosmic-ray neutron sensors
Feasibility of irrigation monitoring with cosmic-ray neutron sensors
Accurate soil moisture (SM) monitoring is key in irrigation as it can greatly improve water use efficiency. Recently, cosmic-ray neutron sensors (CRNSs) have been recognized as a promising tool in SM monitoring due to their large footprint of several hectares. CRNSs also have great potential for irr...
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Personal Name(s): | Brogi, Cosimo (Corresponding author) |
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Bogena, Heye / Köhli, Markus / Huisman, Johan Alexander / Hendricks-Franssen, Harrie-Jan / Dombrowski, Olga | |
Contributing Institute: |
Agrosphäre; IBG-3 |
Published in: | Geoscientific instrumentation, methods and data systems, 11 (2022) 2, S. 451 - 469 |
Imprint: |
Göttingen
Copernicus Publ.
2022
|
DOI: |
10.5194/gi-11-451-2022 |
Document Type: |
Journal Article |
Research Program: |
Agro-biogeosystems: controls, feedbacks and impact |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/33359 in citations.
Accurate soil moisture (SM) monitoring is key in irrigation as it can greatly improve water use efficiency. Recently, cosmic-ray neutron sensors (CRNSs) have been recognized as a promising tool in SM monitoring due to their large footprint of several hectares. CRNSs also have great potential for irrigation applications, but few studies have investigated whether irrigation monitoring with CRNSs is feasible, especially for irrigated fields with a size smaller than the CRNS footprint. Therefore, the aim of this study is to use Monte Carlo simulations to investigate the feasibility of monitoring irrigation with CRNSs. This was achieved by simulating irrigation scenarios with different field dimensions (from 0.5 to 8 ha) and SM variations between 0.05 and 0.50 cm3 cm−3. Moreover, the energy-dependent response functions of eight moderators with different high-density polyethylene (HDPE) thickness or additional gadolinium thermal shielding were investigated. It was found that a considerable part of the neutrons that contribute to the CRNS footprint can originate outside an irrigated field, which is a challenge for irrigation monitoring with CRNSs. The use of thin HDPE moderators (e.g. 5 mm) generally resulted in a smaller footprint and thus stronger contributions from the irrigated area. However, a thicker 25 mm HDPE moderator with gadolinium shielding improved SM monitoring in irrigated fields due to a higher sensitivity of neutron counts with changing SM. This moderator and shielding set-up provided the highest chance of detecting irrigation events, especially when the initial SM was relatively low. However, variations in SM outside a 0.5 or 1 ha irrigated field (e.g. due to irrigation of neighbouring fields) can affect the count rate more than SM variations due to irrigation. This suggests the importance of retrieving SM data from the surrounding of a target field to obtain more meaningful information for supporting irrigation management, especially for small irrigated fields. |