Title: Land degradation assessment in an agricultural area of Mongolia: case study in Orkon soum

This study presents detection of vegetation change in Orkhon soum, Mongolia, using Landsat8 Operational Land Imager and Landsat-5 Thematic Mapper images from 2010 and 2015. Normalized Difference Vegetation Index (NDVI) image classification techniques and change detection processes were applied. The aim of this study was therefore to assess the land degradation-based reduction in the amount of green plant material in the vegetative cover and to find if there is a correlation between vegetation cover change with land use, type and soil texture. The vegetation value was divided into six classes from Highly Dense Vegetation to No Vegetation. The results show that the Less Vegetation class has increased by 11.7% and Less Moderate and Moderate vegetation classes decreased by 13.8 and 27.8%, respectively. Highly Dense Vegetation decreased by 11.3%. The settlement and forest area’s vegetation NDVI value changed negatively. The loamy soils NDVI had increased by 10 pixel values. This means that some meadow vegetation cover had changed positively. NDVI Values for sandy clay loamy and loamy sand soil area had decreased more than 20 pixel values, indicating loss of vegetative cover.