Layer

Data source

Observations

Contours and elevation points

srtm.csi.cgiar.org/srtmdata

The data was derived from SRTM DEM

Bathymetry

http://www.gebco.net

The data was derived for openseamap from the GEBCO_2014 Grid

Roads and Railroads

https://extract.bbbike.org/

Open street map (after selection, generalization and simplification)

Land use

● Open Street map

● Google earth

● Landsat images

The data was derived from OSM road layer and completed and verified by interpreting Landsat images and google earth images

Points of interest (POIs)

Toponyms

● Google maps

● Google earth

● Geoportal of Jeddah Municipality (smartmap.jeddah.gov.sa)

● Saudi addresses geoportal (maps.adress.gov.sa)

The data was gathered and verified from various sources (crowd-sourced and official data)

Industrial areas

https://modon.gov.sa/ar/Pages/default.aspx

Free data provided by the Saudi authority for industrial cities and technology zones

hydrography

● Old maps

● SRTM DEM

● Landsat images

The data was digitized from legacy maps, and updated by thalweg layer extracted from SRTM DEM and verified by the photo interpretation of Landsat image

Green areas

Landsat images (downloaded from earthexplorer.usgs.gov)

The data was extracted from Normalized Difference Vegetation Index (NDVI)