interception

1. The amount of precipitation caught on vegetation or structures that is subsequently evaporated without reaching the ground.
2. The process by which precipitation is caught and retained on vegetation or structures, which afterward either reaches the ground as throughfall or is evaporated.
   As a general rule, this loss to runoff or stream discharge only occurs at the beginning of a storm.
   
3. The loss of sunshine, a part of which may be intercepted by hills, trees, or tall buildings.
   This loss must be accounted for when evaluating instrumental records of sunshine.
   
4. The loss of a portion of the solar spectrum due to absorption and scattering by atmospheric gases and aerosols; commonly refers to the absorption of ultraviolet radiation by ozone and aerosols.

A law or regulation that governs behavior, actions, or operations.