Acid deposition monitoring covers four environmental media - wet deposition, dry deposition, soil and vegetation, and inland aquatic environment. Monitoring for wet and dry deposition are implemented in order to measure concentrations and fluxes of acidic substances deposited to the ground, while monitoring for soil and vegetation, and inland aquatic environment are being implemented to assess adverse impacts on terrestrial and aquatic ecosystems.


1. Wet Deposition

  • Monitoring Interval
    • every 24 hours or every precipitation event for an urban, rural or remote site
  • Major Parameters
    • Precipitation analysis: pH, electrical conductivity (EC), concentrations of
      sulfate (SO42-), nitrate (NO3-) and other ions

2. Dry Deposition

  • Monitoring Interval
    • every day to two weeks, or every hour when measured by automatic instruments
  • Major Measurements
    • Gases: concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and others
    • Particulate components

3. Soil and Vegetation

  • Monitoring Interval
    • once three to five year
  • Major Parameters
    • Soil:
      pH, concentrations of exchangeable ions and effective cation exchange capacity (ECEC)
    • Vegetation (forest):
      survey of tree decline, and general description of a forest

4. Inland Aquatic Environment

  • Monitoring Interval
    • More than four times a year
  • Major Parameters
    • Inland water :
      pH, electrical conductivity (EC), alkalinity and ions

5. Catchment

  • Monitoring Interval
    • continuously (precipitation and discharge), every week to 2 weeks (chemical components)
  • Major Parameters
    • Rainwater and stream water:
      Precipitation amount, discharge from the stream, major cations (Ca2+, NH4+, etc.) and anions (SO42-, NO3-, etc.), estimation of total deposition (wet + dry), etc.