Fuzzy-logic indicators for riverbed de-clogging suggest ecological benefits of large wood
Rivers provide dynamic habitats with ecological niches, particularly in their mobile sand, gravel, and cobble riverbed patches that create an active hyporheic zone. Natural or artificial deposition of fine sediment may clog the porous matrix of the hyporheic zone, impairing exchange processes betwee...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-11-01
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| Series: | Ecological Indicators |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1470160X23011871 |
| _version_ | 1827788690911395840 |
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| author | Sebastian Schwindt Beatriz Negreiros Maria Ponce Isabella Schalko Simone Lassar Ricardo Barros Stefan Haun |
| author_facet | Sebastian Schwindt Beatriz Negreiros Maria Ponce Isabella Schalko Simone Lassar Ricardo Barros Stefan Haun |
| author_sort | Sebastian Schwindt |
| collection | DOAJ |
| description | Rivers provide dynamic habitats with ecological niches, particularly in their mobile sand, gravel, and cobble riverbed patches that create an active hyporheic zone. Natural or artificial deposition of fine sediment may clog the porous matrix of the hyporheic zone, impairing exchange processes between the subsurface and surface water. Clogging reduces the permeability of the sediment matrix, thus degrading the ecological functionality of the hyporheic zone. Once clogged, the ecological functions may be recovered through active stream restoration, which requires considerate site assessment. To this end, clogging is typically assessed by expert opinion of substrate characteristics including grain size characteristics, porosity, hydraulic conductivity, and interstitial oxygen content. To overcome limitations of expert assessment, such as subjectivity expressed in noisy decision-making, this study introduces a novel fuzzy-logic method based on physically sound rules. The method provides quantitative indicators for clogging and declogging to evaluate the effectiveness of stream restoration. We applied the fuzzy-logic method to test whether the placement of large wood, a common restoration practice, can locally prevent or reduce clogging. Two measurement series from before and after a morphologically effective flood suggested that large wood placements perpendicular to the flow generate elevated amounts of declogging. The tested logs caused a greater amount of declogging within their region of influence than observed at a reference point. The effect was stronger for a log emergent at baseflow. The declogging assessment showed that the novel fuzzy-logic indicators can reasonably overcome subjective judgment by accounting for multi-variate quantitative changes rather than individual parameter trends. |
| first_indexed | 2024-03-11T17:09:07Z |
| format | Article |
| id | doaj.art-31d6578e2c7842dfa203640bafff1513 |
| institution | Directory Open Access Journal |
| issn | 1470-160X |
| language | English |
| last_indexed | 2024-03-11T17:09:07Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ecological Indicators |
| spelling | doaj.art-31d6578e2c7842dfa203640bafff15132023-10-20T06:38:52ZengElsevierEcological Indicators1470-160X2023-11-01155111045Fuzzy-logic indicators for riverbed de-clogging suggest ecological benefits of large woodSebastian Schwindt0Beatriz Negreiros1Maria Ponce2Isabella Schalko3Simone Lassar4Ricardo Barros5Stefan Haun6Institute for Modelling Hydraulic and Environmental Systems, University of Stuttgart, Stuttgart, Germany; Corresponding author.Institute for Modelling Hydraulic and Environmental Systems, University of Stuttgart, Stuttgart, GermanyInstitute for Modelling Hydraulic and Environmental Systems, University of Stuttgart, Stuttgart, GermanyDepartment of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Institute of Fluid Dynamics, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, SwitzerlandDepartment of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Natel Energy, Alameda, CA, USAInstitute for Water and River Basin Management, Karlsruhe Institute of Technology, Karlsruhe, GermanyInstitute for Modelling Hydraulic and Environmental Systems, University of Stuttgart, Stuttgart, GermanyRivers provide dynamic habitats with ecological niches, particularly in their mobile sand, gravel, and cobble riverbed patches that create an active hyporheic zone. Natural or artificial deposition of fine sediment may clog the porous matrix of the hyporheic zone, impairing exchange processes between the subsurface and surface water. Clogging reduces the permeability of the sediment matrix, thus degrading the ecological functionality of the hyporheic zone. Once clogged, the ecological functions may be recovered through active stream restoration, which requires considerate site assessment. To this end, clogging is typically assessed by expert opinion of substrate characteristics including grain size characteristics, porosity, hydraulic conductivity, and interstitial oxygen content. To overcome limitations of expert assessment, such as subjectivity expressed in noisy decision-making, this study introduces a novel fuzzy-logic method based on physically sound rules. The method provides quantitative indicators for clogging and declogging to evaluate the effectiveness of stream restoration. We applied the fuzzy-logic method to test whether the placement of large wood, a common restoration practice, can locally prevent or reduce clogging. Two measurement series from before and after a morphologically effective flood suggested that large wood placements perpendicular to the flow generate elevated amounts of declogging. The tested logs caused a greater amount of declogging within their region of influence than observed at a reference point. The effect was stronger for a log emergent at baseflow. The declogging assessment showed that the novel fuzzy-logic indicators can reasonably overcome subjective judgment by accounting for multi-variate quantitative changes rather than individual parameter trends.http://www.sciencedirect.com/science/article/pii/S1470160X23011871MultiPACFine sedimentHyporheic exchangeColmationEcohydraulics |
| spellingShingle | Sebastian Schwindt Beatriz Negreiros Maria Ponce Isabella Schalko Simone Lassar Ricardo Barros Stefan Haun Fuzzy-logic indicators for riverbed de-clogging suggest ecological benefits of large wood Ecological Indicators MultiPAC Fine sediment Hyporheic exchange Colmation Ecohydraulics |
| title | Fuzzy-logic indicators for riverbed de-clogging suggest ecological benefits of large wood |
| title_full | Fuzzy-logic indicators for riverbed de-clogging suggest ecological benefits of large wood |
| title_fullStr | Fuzzy-logic indicators for riverbed de-clogging suggest ecological benefits of large wood |
| title_full_unstemmed | Fuzzy-logic indicators for riverbed de-clogging suggest ecological benefits of large wood |
| title_short | Fuzzy-logic indicators for riverbed de-clogging suggest ecological benefits of large wood |
| title_sort | fuzzy logic indicators for riverbed de clogging suggest ecological benefits of large wood |
| topic | MultiPAC Fine sediment Hyporheic exchange Colmation Ecohydraulics |
| url | http://www.sciencedirect.com/science/article/pii/S1470160X23011871 |
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