Acid deposition in the Netherlands, 1980-2001

Developments in acid deposition

The average deposition of potential acid on Dutch soil in 2001 was 2,850 mol acid/ha (1 mol acid/ha corresponds to 1 acid equivalent/ha). This means that potential acid deposition has increased by 60% since 1980. Potential acid deposition on nature was, on average, 2,980 mol/ha. This means that 10% of the natural environment is protected.
This fall in acid deposition is primarily due to the sharp reduction in SO₂ emissions since 1980, both in the Netherlands and abroad. The reduction in the Netherlands was 80%.
Emissions of nitrogen oxides (NO_x) in the Netherlands have fallen by 30% since 1980. Emissions of ammonia (NH₃) from agricultural sources in the Netherlands fell by 40% in the same period. The relative contribution of nitrogen compounds to potential acid deposition has increased as a result of these changes in emissions from 43 to 81%.

Policy

The objective for potential acid deposition is an average of 2,150 mol acid/ha for Dutch ecosystems in 2010. In that case, 20% of the surface area of the Dutch natural environment will be completely protected (VROM, 2001).

Relevance

The listed substances contribute to the acidification and eutrophication of soil and water. Direct exposure to these substances can also result in damage to human health and to damage to materials and ecosystems.

Technical note

Potential acid is the maximum amount of acid that can be formed. In reality, this amount may not be released.

Potential acid deposition for the years prior to 1999 is calculated using the Dutch Empirical Acid Deposition Model (DEADM). This model derives figures for deposition from the measurements made by the National Air Quality Measurement Network. The OPS (Operational Priority Substances) atmospheric transport and deposition model was used for ammonia only. Since 1999, potential acid deposition has been calculated using the OPS model only.

Relevant information outside of the Environmental Data Compendium

Information about current and future developments relating to acidification can be found in Environmental Balance 2002 and National environmental outlook 2000-2030.

Information about the plans of political parties relating to acidification can be found in 'Verkiezingen 2002' (RIVM, report no. 408 129 025, Bilthoven).