urba - volc
- urbacid
- urbacsulf
- urban air pollution
- urban air quality
- urban air spread
- urban area
- urban blight
- urban catchment
- urban center
- urban channel
- urban channels
- urban clean-up
- urban climate
- urban climatology
- urban combined-sewage system
- urban crowding
- urban decay
- urban design
- urban dust
- urban ecology
- urban ecosystem
- urban environment
- urban forestry
- urban fringe
- urban garden
- urban green belt
- urban greening
- urban growth
- urban hot spot
- urban hydrology
- urban hygiene
- urban land
- urban land use
- urban landscape
- urban management
- urban matrix
- urban migration
- urban motor vehicle traffic
- urban noise
- urban overcrowding