SIMWE model application on susceptibility analysis to bank gully erosion in Alto Douro Wine Region agricultural terraces

- An evaluation of susceptibility to bank gullies is proposed.
- The SIMWE model is compared with soil characteristics, of the study area.
- The areas of bank gullies coincide with the results of soil characteristics.
- The critical areas show the connection between the inventoried of bank gullies.
- The obtained results seem to indicate a medium performance of the SIMWE model.

This paper focuses on the susceptibility evaluation to bank gullies on earthen embankments through the application of SIMWE (SIMulated Water Erosion) model, using a high resolution digital elevation model (1 meter spatial resolution). The results provided by the model are compared with the hydrologic characteristics, soil texture and soil structure of the agricultural terraces. This approach demonstrates an association between the spatial distribution of erosive forms with high values of water depth and reduced water discharge that are consistent with the lower values of electrical resistivity. The areas with the highest percentage of erosive forms, related to sediment flux, transport capacity and sediment concentration susceptibility, assume medium values. These figures, combined with a low hydraulic conductivity and soil infiltration capacity, are consistent with the fine texture of soils, allowing increased runoff and the development of linear erosion.