Integrated Low-Cost Approach for Measuring the State of Conservation of Agricultural Terraces in Tuscany, Italy

Agricultural terraces are an important element of the Italian landscape. However, aban-donment of agricultural areas and increase in the frequency of destructive rainfall events has made itmandatory to increase conservation efforts of terraces to reduce hydrological risks. This requires thedevelopment of new approaches capable of identifying and mapping failed or prone-to-fail terracesover large areas. The present work focuses on the development of a more cost-effective alternative,to help public administrators and private land owners to identify fragile areas that may be subjectto failure due to the abandonment of terracing systems. We developed a simple field protocol toacquire quantitative measurements of the degree of damage—dry stone wall deformation—andestablish a damage classification system. This new methodology is tested at two different sites inTuscany, central Italy. The processing is based on existing DTMs derived from Airborne Laser Scanner(ALS) data and open source software. The main GIS modules adopted are flow accumulation andwater discharge, processed with GRASS GIS. Results show that the damage degree and terrace walldeformation are correlated with flow accumulation even if other factors other than those analyzedcan contribute to influence the instability of dry stone walls. These tools are useful for local landmanagement and conservation efforts.