Technical University of Denmark
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ALEX17 high-resolution, digital information of topography, surface and aerodynamic roughness of the experimental domain

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Version 2 2021-03-26, 11:25
Version 1 2019-06-12, 13:45
posted on 2021-03-26, 11:25 authored by Roberto Aurelio Chavez Arroyo
The present dataset is part of the Alaiz Experiment-2017 (ALEX17). The information is divided into two groups based on their source. 1)Two raster-tpye geotif files containing the Digital Elevation and Digital Surface Models (DEM and DSM) data of the ALEX17 domain. The models were built by TRACASA ( which is a company part of the Navarra Government. The original dataset is cropped to fit the ALEX17 experimental domain with the following spatial coverage: 607700, 4720300 628010, 4738800 The datasets are generated through lidar airborne scans taken during years 2011 and 2012 and updated by photogrammetry with orthophotos of year 2014. The original lidar scans (2011-2012) have a density of 1pnt/m^2 . The raw data are then processed and converted to orthometric heights (from the original ellipsoidal heights ) and later projected into a 2x2m grid with spatial reference EPSG:25830. The conversion from ellipsoidal to orthometric height is carried out with the EGM2008_REDNAP model, generated by the Spanish Geographic National Institute available in: 2)The second dataset is also a raster-type file which contains the approximate annual mean of aerodynamic roughness length in meters. The maps was created with two data sources: Visual estimation of the roughness length values & zones. The Corine Land Cover (CLC) 2006 data. 2.1) The visual estimations of roughness values w carried out with the use of both, orthophotos gathered from the National Geographic Institute of Spain (IGN) as well as site visits. These values were assigned to the Alaiz mountain region while the 2.2) CLC-derived roughness was set to the rest of the domain area. The orthophotos are obtained from the National Plan for Aerial Orthophotogrpy (PNOA) program (available at ). These photos have a pixel size of 50cm and were taken in summer 2014. On the other hand, the Corine Land Cover (CLC) 2006 raster dataset have a 100 m grid size. These data are available at land-cover-2006-raster-3 ( file). The roughness values were derived from the Land Cover data mostly based on the relation between CLC and the aerodynamic roughness length applied by the Finnish wind atlas ( ). The final composed roughness raster map was built by interpolation (nearest-neighbor) of the two data sources onto a 10x10 meters grid . The map is also projected with the same spatial reference as the DEM/DSM data described above.



Ministry of Science, Innovation and Universities of Spain (PCIN-2014-011-C07-02)



Domain SW edge: 42°37'39.43"N, 1°41'11.675"W; NE edge: 42°47'27.79"N, 1°26'05.26"W


Lidar scans from 2011-2012 updated by photogrammetry from 2014.


  • Siting;>Wind Mapping
  • Siting;>Resource assessment
  • Siting;>Spatial planning;>Other


  • Not applicable


  • Measurements;>Other

External conditions

  • Location;>Onshore;>Inland
  • Topography;>Rural
  • Terrain type;>Complex;>Hilly
  • Terrain type;>Complex;>Ridge
  • Topography;>Forest

Data category

  • Topographic data


Víctor García Morales (, Ana Leránoz Goñi (