Assessment of spatio-temporal land-use changes over Greece from 2001 to 2018

Abstract:

IPCC’s Special Report on land use, land-use change, and forestry has reported an average annual global carbon emission attributed to land-use changes from 1980 to 1998, to amount to almost 25% compared to emissions from fossil fuels. Acquiring ground data of land uses at appropriate spatial and temporal resolution for reliable land-use change assessment requires both cost and effort. Therefore, remotely sensed information may prove to be a robust tool for studying land-use changes. The present work deals with the assessment of land-use changes in a Mediterranean country, i.e. Greece, where expected climate change impacts are stated to be severe. According to recent works, desertification risk is steadily increasing in Greece over the last decades. Those modeled based studies assimilated statistical, environmental, land-use and policy information using overlay and index methods aiming to estimate quality indices of desertification. This work focused on the analysis of remotely sensed MODIS land cover type product (MCD12Q1) at a spatial resolution of 500 m and at an annual time step, from 2001 to 2018 and selected Landsat images at 30 m spatial resolution during the same period. Results did not reveal any substantial land-use change corresponding to land degradation or desertification. Our outcomes indicated that the dominant land-use changes in Greece over the predefined 18-year period, are related to land transformation from Savannas and Grasslands to Woody Savannas, from Grasslands to Savannas and vice versa, and from Croplands to Grasslands. Croplands have demonstrated a steady decrease of their areas, losing approximately 4% of the country’s area. On the other hand, Evergreen Needleleaf Forests demonstrated an increase of almost 3%. Areas where land-uses have changed during the study period are found adjacent to previously changed land. Furthermore, altitude ranging from 0 to 700 meters seems to favor the dominant land-use changes. Those observed land-use changes do not correspond to evolving desertification as Barren lands did not show any substantial change. Land-use changes in Greece seem to be mostly related to the abandonment of rural areas, probably due to recent economic recession and the consequent alteration of land to more natural types like Savannas, Woody Savannas, Grasslands and Forests.