Long-Term Impact of Soil and Water Conservation Measures on Soil Erosion in a Tunisian Semi-Arid Watershed
Understanding and long-term assessment of the efficacy of soil and water conservation (SWC) techniques is essential for sustainable watershed management. There have been few studies measuring the long-term impact of SWC on soil erosion at the catchment scale due to a lack of historical data. This re...
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| Format: | Article |
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MDPI AG
2023-08-01
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| Series: | Land |
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| Online Access: | https://www.mdpi.com/2073-445X/12/8/1537 |
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| author | Fathia Jarray Taoufik Hermassi Mohamed Mechergui Claudio Zucca Quang Bao Le |
| author_facet | Fathia Jarray Taoufik Hermassi Mohamed Mechergui Claudio Zucca Quang Bao Le |
| author_sort | Fathia Jarray |
| collection | DOAJ |
| description | Understanding and long-term assessment of the efficacy of soil and water conservation (SWC) techniques is essential for sustainable watershed management. There have been few studies measuring the long-term impact of SWC on soil erosion at the catchment scale due to a lack of historical data. This research aims to measure and analyze the impact of SWC interventions on sediment yield using the Soil and Water Assessment Tool (SWAT) in the Wadi Rmel watershed between 2000 and 2020. The study approach has simultaneously three main aspects: (i) long-term and temporally dynamic, (ii) large-scale landscape distribution, and (iii) empirical evidence of impacts induced by terracing measures. Historical data on SWC in 2000, 2005, 2010, 2015, and 2020 were used for running the model. The monthly calibration (2001–2014) using the SUFI2 algorithm was implemented with 22 input parameters and displayed a good model performance, with a Nash–Sutcliffe efficiency (NSE) of 0.61 for daily runoff and a coefficient of determination (R<sup>2</sup>) of 0.66. A satisfactory result was obtained for the monthly validation process (2015–2020) with NSE value equal to 0.83 and R<sup>2</sup> value of 0.85. The result showed the increase in terracing areas led to a cumulative decrease in watershed sediment yield in long-term, i.e., the reduced erosion per one hectare of the expanded terracing area after 10–20 years were about 9–33 times higher than those in the first 5 years. This finding suggests that maximal benefits of SWC should be expected in the long-term, i.e., beyond a decade. Additionally, the study revealed variations in sediment yield contribution among sub-basins, with the southwestern region being the degradation hotspot areas (having erosion exceeding tolerable thresholds) needing prioritization for erosion controls. These findings enable stakeholders to plan effective management in semi-arid wheat-based agricultural areas with scarce data. |
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| language | English |
| last_indexed | 2024-03-10T23:48:26Z |
| publishDate | 2023-08-01 |
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| series | Land |
| spelling | doaj.art-58426febaec2475782c182e3ebe8f9722023-11-19T01:50:55ZengMDPI AGLand2073-445X2023-08-01128153710.3390/land12081537Long-Term Impact of Soil and Water Conservation Measures on Soil Erosion in a Tunisian Semi-Arid WatershedFathia Jarray0Taoufik Hermassi1Mohamed Mechergui2Claudio Zucca3Quang Bao Le4Department of Rural, Water and Forest Engineering, National Institute of Agronomy of Tunisia (INAT), 43, Avenue Charles Nicolle, Tunis 1082, TunisiaLaboratory of Rural Engineering, National Research Institute of Rural Engineering, Water and Forests (INRGREF), Rue Hédi El Karray El Menzah IV-BP N° 10, Ariana 2080, TunisiaDepartment of Rural, Water and Forest Engineering, National Institute of Agronomy of Tunisia (INAT), 43, Avenue Charles Nicolle, Tunis 1082, TunisiaDepartment of Agriculture Sciences, University of Sassari, 39 Viale Italia, 07100 Sassari, ItalyInternational Center for Agricultural Research in the Dry Areas (ICARDA), c/o Institut National de Recherche Agronomique de Tunis (INRAT), Av. Hedi Karray, Tunis 2049, TunisiaUnderstanding and long-term assessment of the efficacy of soil and water conservation (SWC) techniques is essential for sustainable watershed management. There have been few studies measuring the long-term impact of SWC on soil erosion at the catchment scale due to a lack of historical data. This research aims to measure and analyze the impact of SWC interventions on sediment yield using the Soil and Water Assessment Tool (SWAT) in the Wadi Rmel watershed between 2000 and 2020. The study approach has simultaneously three main aspects: (i) long-term and temporally dynamic, (ii) large-scale landscape distribution, and (iii) empirical evidence of impacts induced by terracing measures. Historical data on SWC in 2000, 2005, 2010, 2015, and 2020 were used for running the model. The monthly calibration (2001–2014) using the SUFI2 algorithm was implemented with 22 input parameters and displayed a good model performance, with a Nash–Sutcliffe efficiency (NSE) of 0.61 for daily runoff and a coefficient of determination (R<sup>2</sup>) of 0.66. A satisfactory result was obtained for the monthly validation process (2015–2020) with NSE value equal to 0.83 and R<sup>2</sup> value of 0.85. The result showed the increase in terracing areas led to a cumulative decrease in watershed sediment yield in long-term, i.e., the reduced erosion per one hectare of the expanded terracing area after 10–20 years were about 9–33 times higher than those in the first 5 years. This finding suggests that maximal benefits of SWC should be expected in the long-term, i.e., beyond a decade. Additionally, the study revealed variations in sediment yield contribution among sub-basins, with the southwestern region being the degradation hotspot areas (having erosion exceeding tolerable thresholds) needing prioritization for erosion controls. These findings enable stakeholders to plan effective management in semi-arid wheat-based agricultural areas with scarce data.https://www.mdpi.com/2073-445X/12/8/1537long-term impactsediment yieldsoil–water conservationsustainable land managementSWATsensitivity analysis |
| spellingShingle | Fathia Jarray Taoufik Hermassi Mohamed Mechergui Claudio Zucca Quang Bao Le Long-Term Impact of Soil and Water Conservation Measures on Soil Erosion in a Tunisian Semi-Arid Watershed Land long-term impact sediment yield soil–water conservation sustainable land management SWAT sensitivity analysis |
| title | Long-Term Impact of Soil and Water Conservation Measures on Soil Erosion in a Tunisian Semi-Arid Watershed |
| title_full | Long-Term Impact of Soil and Water Conservation Measures on Soil Erosion in a Tunisian Semi-Arid Watershed |
| title_fullStr | Long-Term Impact of Soil and Water Conservation Measures on Soil Erosion in a Tunisian Semi-Arid Watershed |
| title_full_unstemmed | Long-Term Impact of Soil and Water Conservation Measures on Soil Erosion in a Tunisian Semi-Arid Watershed |
| title_short | Long-Term Impact of Soil and Water Conservation Measures on Soil Erosion in a Tunisian Semi-Arid Watershed |
| title_sort | long term impact of soil and water conservation measures on soil erosion in a tunisian semi arid watershed |
| topic | long-term impact sediment yield soil–water conservation sustainable land management SWAT sensitivity analysis |
| url | https://www.mdpi.com/2073-445X/12/8/1537 |
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