unde - vasq
- undercut karren
- underdrainage
- underfit stream
- underflow
- underflow spring
- underground divide
- underground river
- underground stream
- underground waters
- uniaxial (unconfined) compression
- uniaxial state of stress
- uniform flow
- uniformity coefficient
- unit-hydrograph
- unsaturated coefficient of permeability
- unsaturated flow
- unsaturated zone
- unsteady flow