Identification, mapping, and characterisation of a mature artificial mole channel network using ground-penetrating radar
Mole channel drainage is a cost-effective and efficient way to drain slowly permeable agricultural soils. Artificial drainage has the potential to significantly influence catchment hydrology and contaminant source areas, but there is little information available about the extent, connectivity, layou...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-10-01
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| Series: | Agricultural Water Management |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0378377423003426 |
| _version_ | 1827834855737524224 |
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| author | Kirstin Ella Deuss Peter C. Almond Sam Carrick Lawrence John Kees |
| author_facet | Kirstin Ella Deuss Peter C. Almond Sam Carrick Lawrence John Kees |
| author_sort | Kirstin Ella Deuss |
| collection | DOAJ |
| description | Mole channel drainage is a cost-effective and efficient way to drain slowly permeable agricultural soils. Artificial drainage has the potential to significantly influence catchment hydrology and contaminant source areas, but there is little information available about the extent, connectivity, layout, density or longevity of mole channel networks, which are commonly estimated to deteriorate within 5–20 years. Such information is important for understanding landscape hydrodynamics but, currently, there are no established techniques for calibrating estimates of mole network characteristics at the paddock or larger scale. This study characterised a 30-plus-year-old mole channel network in a small agricultural basin in Southland, New Zealand, and tested the utility of ground-penetrating radar (GPR) for identifying, mapping, and characterising mole channel drainage. A dual frequency GPR antenna (700 and 250 MHz), connected to a high-precision, real-time kinematic global positioning system, was tested and proved effective at locating mole channels and a tile drain with high lateral precision and accuracy. Surveying of six plots demonstrated that the mole network was complex in design and had a high density (1.6 m m−2) of interconnected, multidirectional mole channels. Significantly, the mole channels were predominantly in good condition and spatially well connected. Visual observations found no evidence that the blade slot and secondary soil fractures, formed by the mole plough during installation, persisted after 30 years. However, root growth and worm burrowing into the mole channels suggest they are hydraulically connected to the surrounding soil through natural macropores. Our results provide the first attempt at mapping and characterising mature, multi-generational mole channel networks in slowly permeable loess soils. The results have significance for understanding catchment-scale hydrodynamics in mole-drained landscapes, especially considering that the life span of these artificial drainage networks is shown to be considerably longer than previous estimates for loess-derived, silt loam soils. |
| first_indexed | 2024-03-12T05:58:58Z |
| format | Article |
| id | doaj.art-d62bf3c21c2d40cbabc2a26aa318a48c |
| institution | Directory Open Access Journal |
| issn | 1873-2283 |
| language | English |
| last_indexed | 2024-03-12T05:58:58Z |
| publishDate | 2023-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Agricultural Water Management |
| spelling | doaj.art-d62bf3c21c2d40cbabc2a26aa318a48c2023-09-03T04:23:25ZengElsevierAgricultural Water Management1873-22832023-10-01288108477Identification, mapping, and characterisation of a mature artificial mole channel network using ground-penetrating radarKirstin Ella Deuss0Peter C. Almond1Sam Carrick2Lawrence John Kees3Department of Soil and Physical Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand; Corresponding author.Department of Soil and Physical Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New ZealandManaaki Whenua − Landcare Research, PO Box 69040, Lincoln 7640, New ZealandNational Institute of Water and Atmospheric Research, PO Box 8602, Riccarton, Christchurch 8440, New ZealandMole channel drainage is a cost-effective and efficient way to drain slowly permeable agricultural soils. Artificial drainage has the potential to significantly influence catchment hydrology and contaminant source areas, but there is little information available about the extent, connectivity, layout, density or longevity of mole channel networks, which are commonly estimated to deteriorate within 5–20 years. Such information is important for understanding landscape hydrodynamics but, currently, there are no established techniques for calibrating estimates of mole network characteristics at the paddock or larger scale. This study characterised a 30-plus-year-old mole channel network in a small agricultural basin in Southland, New Zealand, and tested the utility of ground-penetrating radar (GPR) for identifying, mapping, and characterising mole channel drainage. A dual frequency GPR antenna (700 and 250 MHz), connected to a high-precision, real-time kinematic global positioning system, was tested and proved effective at locating mole channels and a tile drain with high lateral precision and accuracy. Surveying of six plots demonstrated that the mole network was complex in design and had a high density (1.6 m m−2) of interconnected, multidirectional mole channels. Significantly, the mole channels were predominantly in good condition and spatially well connected. Visual observations found no evidence that the blade slot and secondary soil fractures, formed by the mole plough during installation, persisted after 30 years. However, root growth and worm burrowing into the mole channels suggest they are hydraulically connected to the surrounding soil through natural macropores. Our results provide the first attempt at mapping and characterising mature, multi-generational mole channel networks in slowly permeable loess soils. The results have significance for understanding catchment-scale hydrodynamics in mole-drained landscapes, especially considering that the life span of these artificial drainage networks is shown to be considerably longer than previous estimates for loess-derived, silt loam soils.http://www.sciencedirect.com/science/article/pii/S0378377423003426Subsurface agricultural drainageSoil waterCatchment hydrologyContaminant transferPreferential flow |
| spellingShingle | Kirstin Ella Deuss Peter C. Almond Sam Carrick Lawrence John Kees Identification, mapping, and characterisation of a mature artificial mole channel network using ground-penetrating radar Agricultural Water Management Subsurface agricultural drainage Soil water Catchment hydrology Contaminant transfer Preferential flow |
| title | Identification, mapping, and characterisation of a mature artificial mole channel network using ground-penetrating radar |
| title_full | Identification, mapping, and characterisation of a mature artificial mole channel network using ground-penetrating radar |
| title_fullStr | Identification, mapping, and characterisation of a mature artificial mole channel network using ground-penetrating radar |
| title_full_unstemmed | Identification, mapping, and characterisation of a mature artificial mole channel network using ground-penetrating radar |
| title_short | Identification, mapping, and characterisation of a mature artificial mole channel network using ground-penetrating radar |
| title_sort | identification mapping and characterisation of a mature artificial mole channel network using ground penetrating radar |
| topic | Subsurface agricultural drainage Soil water Catchment hydrology Contaminant transfer Preferential flow |
| url | http://www.sciencedirect.com/science/article/pii/S0378377423003426 |
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