- initial retention
- inflatable
- inflow flood
- initial rain
- interfacial tension
- interference source
- intertidal zone
- inversion layer
- ion budget
- isolated flood
- juvenile spring
- jet stream
- jib boom
- lake precipitation
- land degradation
- land disturbance
- land pollutant
- land pollution
- landscape rehabilitation
- latter rainfall
- late flood
- lateral guidance
- lead additives
- lethal effect
- lighten
- lightening vessel
- liquid chromatography
- littoral rainfall
- living community
- local emission
- load regime
- lotic environment
- main flood
- magmatic eruption
- marine dredge
- material pollution
- maximum precipitation
- maximum rainfall
- meteorite conditions
- miscible substance
- mineral vein
- minimum precipitation
- mobile component
- meteorological data
- mineral spring
- monsoon flood
- monthly flood
- monthly precipitation
- monthly rainfall
- motor pump
- mud spate
- mooring bracket
- natural acidification
- natural environment
- natural complex
- natural sill
- net donator
- neat
- new plant
- nitric oxide
- nitrogen peroxide
- net receiver
- nitrogen dioxide
- nitrogen pentoxide
- noisy
- normal flood
- nonacidic lake
- normal rainfall
- offshore well
- oil boom
- odor emissions
- odour emissions
- oil mop
- oil spill
- oleophilic belt
- operational error
- observed flood
- oil pollution
- old deposit
- overdosage
- ozone damage
- ozone concentration
- parlic environment
- particulate matter
- past flood
- peak concentration
- peak rainfall
- pelagic environment
- perennial spring
- petroleum product
- PH drop
- phreatomagmatic eruption
- pleasure fishes
- pliohaline
- pluvial discharge
- planned environment
- point rainfall
- pollutant deposition
- polluted environment
- polluted rainwater