Title: Vehicle off-road erosion assessment in Southern Mongolia

Off-road-related degradation is one of the worst problems of land degradation in Mongolia. Currently, Mongolia has over 50,000 km of roads and tracks used for transport and the latter are especially common around mining activities. The aim of this study was to evaluate two selected potential and feasible methods to assess off-road track-related degradation, both within the tracks themselves and in the immediate surroundings. The two different approaches used in this study were NDVI (Normalized Difference Vegetation Index) used to assess the impact on larger scales, and local track experiment at transects running perpendicular to the tracks for estimating local impacts to be able to further establish the track impact on the immediate surroundings. The results indicate that lower NDVI values, corresponding to less vegetation cover, are consistently found in closer proximities to the tracks. The track experiment showed that after the track had been driven 50 times, the surface had subsided up to 2.8 cm. Soil bulk densities increased by 1.66 gr/cm3 and 2.12 gr/cm3 at 5 and 20 cm, respectively. Soil moisture and porosity decreased by 30% in subsoil on average. The soil erosion estimation was 300 t/ha2 on off-road tracks.