Feasibility of irrigation monitoring with cosmic-ray neutron sensors
<p>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 potentia...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-12-01
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| Series: | Geoscientific Instrumentation, Methods and Data Systems |
| Online Access: | https://gi.copernicus.org/articles/11/451/2022/gi-11-451-2022.pdf |
| _version_ | 1828115717544738816 |
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| author | C. Brogi H. R. Bogena M. Köhli J. A. Huisman H.-J. Hendricks Franssen O. Dombrowski |
| author_facet | C. Brogi H. R. Bogena M. Köhli J. A. Huisman H.-J. Hendricks Franssen O. Dombrowski |
| author_sort | C. Brogi |
| collection | DOAJ |
| description | <p>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 cm<span class="inline-formula"><sup>3</sup></span> cm<span class="inline-formula"><sup>−3</sup></span>.
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.</p> |
| first_indexed | 2024-04-11T12:45:54Z |
| format | Article |
| id | doaj.art-fb4178fcb04a4b58ae9af5b1885cae8f |
| institution | Directory Open Access Journal |
| issn | 2193-0856 2193-0864 |
| language | English |
| last_indexed | 2024-04-11T12:45:54Z |
| publishDate | 2022-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Instrumentation, Methods and Data Systems |
| spelling | doaj.art-fb4178fcb04a4b58ae9af5b1885cae8f2022-12-22T04:23:23ZengCopernicus PublicationsGeoscientific Instrumentation, Methods and Data Systems2193-08562193-08642022-12-011145146910.5194/gi-11-451-2022Feasibility of irrigation monitoring with cosmic-ray neutron sensorsC. Brogi0H. R. Bogena1M. Köhli2J. A. Huisman3H.-J. Hendricks Franssen4O. Dombrowski5Agrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, GermanyAgrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, GermanyPhysikalisches Institut, Heidelberg University, Heidelberg, GermanyAgrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, GermanyAgrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, GermanyAgrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany<p>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 cm<span class="inline-formula"><sup>3</sup></span> cm<span class="inline-formula"><sup>−3</sup></span>. 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.</p>https://gi.copernicus.org/articles/11/451/2022/gi-11-451-2022.pdf |
| spellingShingle | C. Brogi H. R. Bogena M. Köhli J. A. Huisman H.-J. Hendricks Franssen O. Dombrowski Feasibility of irrigation monitoring with cosmic-ray neutron sensors Geoscientific Instrumentation, Methods and Data Systems |
| title | Feasibility of irrigation monitoring with cosmic-ray neutron sensors |
| title_full | Feasibility of irrigation monitoring with cosmic-ray neutron sensors |
| title_fullStr | Feasibility of irrigation monitoring with cosmic-ray neutron sensors |
| title_full_unstemmed | Feasibility of irrigation monitoring with cosmic-ray neutron sensors |
| title_short | Feasibility of irrigation monitoring with cosmic-ray neutron sensors |
| title_sort | feasibility of irrigation monitoring with cosmic ray neutron sensors |
| url | https://gi.copernicus.org/articles/11/451/2022/gi-11-451-2022.pdf |
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