Table 1.
Description of the environmental predictor variables used to fit the species distribution models for Cuvier’s Gazelle.
| Variables | Selected for modelling | Units | Source | Description | Calculation |
|---|---|---|---|---|---|
| Topographic morphology | |||||
| Altitude (ALT) | yes | meters |
Elevation above sea level from SRTM (Shuttle Radar Topography Mission). 1 arc-second (~30 m2) |
Elevation above sea level | |
| Slope (SLOPE) | no | degree | Terrain slope | Slope function. Toolbox. ArcGIS 10.4 | |
| Topographic Ruggedness Index (TRI) | yes | meters | 65Topographic roughness. Calculated as the difference between the value of a cell and the mean of an 8-cell neighbourhood of surrounding cells | 66Geomorphometric and Gradient Metrics Toolbox. ArcGIS 10.4 | |
| Temperature-moisture regime | |||||
| Heat Load Index (HLI) | no | Elevation above sea level from Shuttle Radar Topography Mission (SRTM). 1 arc-second (~30 m2) | 67Potential direct incident radiation in relation with slope and aspect transformation | Geomorphometric and Gradient Metrics Toolbox. ArcGIS 10.4 | |
| Compound Topographic Index (CTI) | yes | 68,69Flow accumulation by catchment size (wetness index) described as a function of both the slope and the upstream contributing area per unit width orthogonal to the flow direction and a quantification of catenary topographic convergence | |||
| Topographic distance and human factor | |||||
| Distance to Coast (DISTCOAST) | no | meters | ArcGIS server | Terrain border | Euclidean distance. ArcGIS 10.4 |
| Distance to Cities and Urban Villages (DISTSETT1) | yes | OpenStreetMap project and Haut Commissariat au Plan, Royaume du Maroc | Distance to the nearest human settlement with more than 1500 inhabitants | ||
| Distance to Rural Villages (DISTSETT2) | yes | Distance to the nearest human settlement with less than 1500 inhabitants | |||
| Vegetation | |||||
| Annual of Maximum Green Vegetation Fraction (AMGVF) | yes | USGS Land Cover Institute (LCI). 30 arc-seconds (~1km2) | Green vegetation fraction estimated from Normalized Difference Vegetation Index (NDVI) | Values calculated on 12 years (2001–2012) of Collection 5 MOD13A2 normalized difference vegetation index (NDVI) | |
| Climatic variation | |||||
| Annual Mean Temperature (BIO1) | yes |
degrees Celsius |
WorldClim database 2.0, 30 arc seconds (~1km2) | Annual Mean Temperature | please merge with cell below |
| Annual Precipitation (BIO2) | yes | millimetres | Annual Precipitation | ||