| Abstract | Soil erosion is the most widespread form of land degradation in Europe as well as in the Mediterranean areas. EU Member States are called to decrease the land degradation by identifying the areas under a high risk of soil erosion and by adopting Best Management Practices (BMPs). In this study, the Soil and Water Assessment Tool (SWAT) was applied to simulate the baseline hydrologic and soil erosion processes in the Carapelle watershed, a medium size watershed located in the south-central Italy (Puglia region) where lands are largely cultivated with winter wheat. The results show that in the Carapelle, soil erosion is mostly contributed by cultivated croplands and it exceeds new soil formation rate, as the estimated average annual sediment load is 6 t ha-1 yr-1. Using the calibrated SWAT model, three management scenarios, which are based on the implemented regional policies, were implemented: contour farming (BMP1), no-tillage (BMP2); reforestation (BMP3). A threshold of sediment yield was selected to discretize target treatment areas for BMPs application. Results show that for erosion control BMP2 was the most effective single scenario (30% reduction; from 6.0 to 4.2 t ha-1) followed by BMP1 (22%; from 6.0 to 4.6 t ha-1) and BMP3 (14%; from 6.0 to 5.0 t ha-1). Moreover, the cumulative effect of combining contour farming and reforestation (BMP4) was tested (37% reduction; from 6.0 to 3.7 t ha-1). The analysis of the farmer return-production cost ratio (FR/PC) revealed that the baseline (no treatment) and BMP1 were both economically sustainable in non-steep slope areas (FR/PC=1.12 and 1.11, respectively). In steep slope areas, the baseline scenario had no economic advantage (FR/PC = 0.93) while BMP3 was ranked at the top (FR/PC=1.49) followed by BMP2 (FR/PC=1.41). The results from this study offer actionable information to policymakers and practitioners considering BMPs implementation in two aspects: how they perform and if they are economically beneficial. Further developments could include the analysis of management scenarios aimed at environmental restoration as well as the cumulative effect of combining different BMPs at the watershed scale. |
| Text | 438415 2019 Modelling soil erosion sediment yield BMPs Modeling regional management scenarios for soil erosion control in a Mediterranean watershed. Ricci, Giovanni Francesco; Jeong, Jaehak; De Girolamo, Anna Maria; Gentile, Francesco University of Bari, Department of Agricultural and Environmental Sciences, Bari, Italy, Texas A M AgriLife Research, Temple, Texas, USA , National Research Council, Water Research Institute IRSA CNR , Bari, Italy University of Bari, Department of Agricultural and Environmental Sciences, Bari, Italy, Published version Vol. 21, EGU2019 13646 21 EGU General Assembly, Vienna 7/04/2019, 12/04/2019 Internazionale Contributo Soil erosion is the most widespread form of land degradation in Europe as well as in the Mediterranean areas. EU Member States are called to decrease the land degradation by identifying the areas under a high risk of soil erosion and by adopting Best Management Practices BMPs . In this study, the Soil and Water Assessment Tool SWAT was applied to simulate the baseline hydrologic and soil erosion processes in the Carapelle watershed, a medium size watershed located in the south central Italy Puglia region where lands are largely cultivated with winter wheat. The results show that in the Carapelle, soil erosion is mostly contributed by cultivated croplands and it exceeds new soil formation rate, as the estimated average annual sediment load is 6 t ha 1 yr 1. Using the calibrated SWAT model, three management scenarios, which are based on the implemented regional policies, were implemented contour farming BMP1 , no tillage BMP2 ; reforestation BMP3 . A threshold of sediment yield was selected to discretize target treatment areas for BMPs application. Results show that for erosion control BMP2 was the most effective single scenario 30% reduction; from 6.0 to 4.2 t ha 1 followed by BMP1 22%; from 6.0 to 4.6 t ha 1 and BMP3 14%; from 6.0 to 5.0 t ha 1 . Moreover, the cumulative effect of combining contour farming and reforestation BMP4 was tested 37% reduction; from 6.0 to 3.7 t ha 1 . The analysis of the farmer return production cost ratio FR/PC revealed that the baseline no treatment and BMP1 were both economically sustainable in non steep slope areas FR/PC=1.12 and 1.11, respectively . In steep slope areas, the baseline scenario had no economic advantage FR/PC = 0.93 while BMP3 was ranked at the top FR/PC=1.49 followed by BMP2 FR/PC=1.41 . The results from this study offer actionable information to policymakers and practitioners considering BMPs implementation in two aspects how they perform and if they are economically beneficial. Further developments could include the analysis of management scenarios aimed at environmental restoration as well as the cumulative effect of combining different BMPs at the watershed scale. Modeling regional management scenarios for soil erosion control in a Mediterranean watershed. EGU2019 13646RicciBMPs.pdf Abstract in atti di convegno annamaria.degirolamo DE GIROLAMO ANNA MARIA |
