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

J. Gonçalves,A. Oliveira,L. Soares,C. Bateira,J. Fernandes,R. Moura,C. Hermenegildo,A. Faria

doi:10.1016/j.catena.2017.01.034

Abstract

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 (1meter 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.

Highlights

The wine production in Alto Douro Wine Region - one of the world's oldest regulated and demarcated wine region - is based on a slope system organized in agricultural terraces once supported exclusively by dry stone walls, which has been undergoing the necessary changes for the introduction of technological innovations partially associated to the mechanization of vineyards work
Different forms of terrain framing have been implemented, namely the substitution of stone walls by earth embankments. This evolution raises a group of problems related to the hydric soil erosion and landscape preservation, since Alto Douro Wine Region is classified as UNESCO World Heritage Site since 2001
The obtained results seems to indicate a moderate performance of the SIMWE model in the identification of the areas more susceptible to the bank gully erosion of the soils in terraced area with earthen embankments

Summary

Introduction

The wine production in Alto Douro Wine Region - one of the world's oldest regulated and demarcated wine region - is based on a slope system organized in agricultural terraces once supported exclusively by dry stone walls, which has been undergoing the necessary changes for the introduction of technological innovations partially associated to the mechanization of vineyards work. In this sense, different forms of terrain framing have been implemented, namely the substitution of stone walls by earth embankments. Fernandes et al / Catena 153 (2017) 39–49 different spatial configuration scenarios of high, medium and low grass coverage showed that protective measures are more efficient when located at the lowest position along slopes

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