Subject
- Soil and civilization21
- Fuelbreaks20
- Oil storage tanks20
- Storage tanks20
- Embankments19
- Fills (Earthwork)19
- Electric lines18
- Hydraulic structures18
- Industrial sites18
- Bridges17
- Ferries17
- Pipelines17
- Railroads17
- Refuse and refuse disposal16
- Vegetation and climate16
- Vegetation mapping16
- Waste disposal sites16
- Watersheds15
- Chimneys14
- Cooling towers14