1. Geography Department; Universitat Autònoma de Barcelona; Cerdanyola del Vallès 08193 Barcelona Spain
2. Center for Geospatial Analytics, Department of Parks, Recreation and Tourism Management; North Carolina State University; Raleigh NC 27695 USA
3. Institute of Environmental Science and Technology; Universitat Autònoma de Barcelona; Cerdanyola del Vallès 08193 Barcelona Spain