The objective of the present work is to present preliminary results of the experimental activities carried out in order to measure sediments yield in a hilly burned area using the silt fence technique, and to evaluate ERMiT (Erosion Risk Management Tool) performance, comparing the results of simulation with soil erosion measured. The experimental area is located in the Mediterranean basin, on a steep slope in a hilly area of north-western Sardinia, Italy, where a human caused fire occurred in August 2013. The area is mainly covered by Quercus suber and Mediterranean shrubs. After the fire, sediment fences were installed to trap sediment eroded by natural rainfall. Rainfall was recorded using a tipping bucket rain gauge. Soil erosion rates from experimental plots were measured and estimated with silt fence technique taking into account vegetation distribution patterns. The aim of the study was to compare the results obtained by ERMIT modelling and post-fire sediment yields measured in the study area. ERMiT is a web-based application developed by USDA that uses WEPP (Water Erosion Prediction Project) technology to estimate erosion, in probabilistic terms, on burned lands with and without the application of erosion mitigation treatments. Data inputs are: climate parameters, vegetation type, soil type, topography, and soil burn severity class. The above parameters were applied to the ERMIT model and it was possible to predict the probable erosion risk for the next 5 years. Model results compared with field measurements show that ERMiT tends to overestimate erosion rates in Mediterranean vegetation and soil conditions due to the higher stability and typical stoniness of Sardinian old soils compared to younger soils where ERMiT was calibrated. Future experimental data are needed to confirm this assumption and to contribute to calibrating ERMiT in a Mediterranean typical vegetation, climate and soils with specific erodibility and conductivity.
PERFORMANCE OF ERMIT IN POST FIRE SOIL EROSION MODELLING IN A NORTH SARDINIAN STUDY AREA
Canu A;Ventura A;
2015
Abstract
The objective of the present work is to present preliminary results of the experimental activities carried out in order to measure sediments yield in a hilly burned area using the silt fence technique, and to evaluate ERMiT (Erosion Risk Management Tool) performance, comparing the results of simulation with soil erosion measured. The experimental area is located in the Mediterranean basin, on a steep slope in a hilly area of north-western Sardinia, Italy, where a human caused fire occurred in August 2013. The area is mainly covered by Quercus suber and Mediterranean shrubs. After the fire, sediment fences were installed to trap sediment eroded by natural rainfall. Rainfall was recorded using a tipping bucket rain gauge. Soil erosion rates from experimental plots were measured and estimated with silt fence technique taking into account vegetation distribution patterns. The aim of the study was to compare the results obtained by ERMIT modelling and post-fire sediment yields measured in the study area. ERMiT is a web-based application developed by USDA that uses WEPP (Water Erosion Prediction Project) technology to estimate erosion, in probabilistic terms, on burned lands with and without the application of erosion mitigation treatments. Data inputs are: climate parameters, vegetation type, soil type, topography, and soil burn severity class. The above parameters were applied to the ERMIT model and it was possible to predict the probable erosion risk for the next 5 years. Model results compared with field measurements show that ERMiT tends to overestimate erosion rates in Mediterranean vegetation and soil conditions due to the higher stability and typical stoniness of Sardinian old soils compared to younger soils where ERMiT was calibrated. Future experimental data are needed to confirm this assumption and to contribute to calibrating ERMiT in a Mediterranean typical vegetation, climate and soils with specific erodibility and conductivity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
