Hydraulic Conductivity Tests in the Triaxial Stress State: Is Peat an Aquitard or an Aquifer?
<b>The characteristics of</b> peat’s are crucial for understanding natural processes and their suitable shaping through the management of water relations. This study focused on the results of one of the first hydraulic conductivity (<i>k</i>) laboratory tests of exemplary pea...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/15/6/1064 |
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| author | Łukasz Kaczmarek Maria Grodzka-Łukaszewska Grzegorz Sinicyn Mateusz Grygoruk Małgorzata Jastrzębska Jan Szatyłowicz |
| author_facet | Łukasz Kaczmarek Maria Grodzka-Łukaszewska Grzegorz Sinicyn Mateusz Grygoruk Małgorzata Jastrzębska Jan Szatyłowicz |
| author_sort | Łukasz Kaczmarek |
| collection | DOAJ |
| description | <b>The characteristics of</b> peat’s are crucial for understanding natural processes and their suitable shaping through the management of water relations. This study focused on the results of one of the first hydraulic conductivity (<i>k</i>) laboratory tests of exemplary peat samples from the Biebrza Valley (a peatland of very high environmental importance) in relation to the stress state and hydraulic gradient. Further, the research was devoted to a specific test procedure of peat permeability as a key feature for landform development in wetlands. Detailed tests of dark brown/black samples were selected as the reference for the research investigations. Four long-term test series of water permeability were performed in a modified triaxial compression apparatus. In all selected hydraulic gradient variants (<i>i</i> = 5,10,25,40,55,85), the <i>k</i> values decreased from 6 × 10<sup>−8</sup> m/s to 1.6 × 10<sup>−10</sup> m/s with a stepwise increase in the effective confining pressures tested (10, 15, 30, 45, and 90 kPa). These results were related to the inherent soil features—a relatively high peat decomposition and external driver—confining pressure (radial stress) magnitude. Compared to the other Polish peat tests, the determined <i>k</i> values were at the lower end of their hydraulic conductivity range. The analysed organic soil is not a typical aquifer. Despite very high porosities (~88%) and a high organic matter content (81.1–89.4%) which is favourable for water accumulation, the characterized peat showed relatively low hydraulic conductivity values. Thus, this specific soil may differentiate the groundwater flow as it complicates strong contact with surface water. |
| first_indexed | 2024-03-11T05:46:07Z |
| format | Article |
| id | doaj.art-c51816febadb4004a4c1ea14cac03ac8 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-11T05:46:07Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-c51816febadb4004a4c1ea14cac03ac82023-11-17T14:25:54ZengMDPI AGWater2073-44412023-03-01156106410.3390/w15061064Hydraulic Conductivity Tests in the Triaxial Stress State: Is Peat an Aquitard or an Aquifer?Łukasz Kaczmarek0Maria Grodzka-Łukaszewska1Grzegorz Sinicyn2Mateusz Grygoruk3Małgorzata Jastrzębska4Jan Szatyłowicz5Faculty of Building Services, Hydro and Environmental Engineering, Warsaw University of Technology, Nowowiejska 20 St., 00-653 Warsaw, PolandFaculty of Building Services, Hydro and Environmental Engineering, Warsaw University of Technology, Nowowiejska 20 St., 00-653 Warsaw, PolandFaculty of Building Services, Hydro and Environmental Engineering, Warsaw University of Technology, Nowowiejska 20 St., 00-653 Warsaw, PolandInstitute of Environmental Engineering, Warsaw University of Life Sciences, Nowoursynowska 166 St., 02-787 Warsaw, PolandFaculty of Civil Engineering, Silesian University of Technology, Akademicka 5 St., 44-100 Gliwice, PolandInstitute of Environmental Engineering, Warsaw University of Life Sciences, Nowoursynowska 166 St., 02-787 Warsaw, Poland<b>The characteristics of</b> peat’s are crucial for understanding natural processes and their suitable shaping through the management of water relations. This study focused on the results of one of the first hydraulic conductivity (<i>k</i>) laboratory tests of exemplary peat samples from the Biebrza Valley (a peatland of very high environmental importance) in relation to the stress state and hydraulic gradient. Further, the research was devoted to a specific test procedure of peat permeability as a key feature for landform development in wetlands. Detailed tests of dark brown/black samples were selected as the reference for the research investigations. Four long-term test series of water permeability were performed in a modified triaxial compression apparatus. In all selected hydraulic gradient variants (<i>i</i> = 5,10,25,40,55,85), the <i>k</i> values decreased from 6 × 10<sup>−8</sup> m/s to 1.6 × 10<sup>−10</sup> m/s with a stepwise increase in the effective confining pressures tested (10, 15, 30, 45, and 90 kPa). These results were related to the inherent soil features—a relatively high peat decomposition and external driver—confining pressure (radial stress) magnitude. Compared to the other Polish peat tests, the determined <i>k</i> values were at the lower end of their hydraulic conductivity range. The analysed organic soil is not a typical aquifer. Despite very high porosities (~88%) and a high organic matter content (81.1–89.4%) which is favourable for water accumulation, the characterized peat showed relatively low hydraulic conductivity values. Thus, this specific soil may differentiate the groundwater flow as it complicates strong contact with surface water.https://www.mdpi.com/2073-4441/15/6/1064triaxial compression apparatusorganic soilconstant head teststructure |
| spellingShingle | Łukasz Kaczmarek Maria Grodzka-Łukaszewska Grzegorz Sinicyn Mateusz Grygoruk Małgorzata Jastrzębska Jan Szatyłowicz Hydraulic Conductivity Tests in the Triaxial Stress State: Is Peat an Aquitard or an Aquifer? Water triaxial compression apparatus organic soil constant head test structure |
| title | Hydraulic Conductivity Tests in the Triaxial Stress State: Is Peat an Aquitard or an Aquifer? |
| title_full | Hydraulic Conductivity Tests in the Triaxial Stress State: Is Peat an Aquitard or an Aquifer? |
| title_fullStr | Hydraulic Conductivity Tests in the Triaxial Stress State: Is Peat an Aquitard or an Aquifer? |
| title_full_unstemmed | Hydraulic Conductivity Tests in the Triaxial Stress State: Is Peat an Aquitard or an Aquifer? |
| title_short | Hydraulic Conductivity Tests in the Triaxial Stress State: Is Peat an Aquitard or an Aquifer? |
| title_sort | hydraulic conductivity tests in the triaxial stress state is peat an aquitard or an aquifer |
| topic | triaxial compression apparatus organic soil constant head test structure |
| url | https://www.mdpi.com/2073-4441/15/6/1064 |
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