Average Accumulated Exceedance (AAE) of critical loads of acidity and nutrient nitrogen by acid and nitrogen deposition for the UK, 2015-2017
bibliographic citation: Rowe, E.C. (2021). Average Accumulated Exceedance (AAE) of critical loads of acidity and nutrient nitrogen by acid and nitrogen deposition for the UK, 2015-2017. NERC Environmental Information Data Centre. https://doi.org/10.5285/b65abf02-bfdb-4546-a3a3-26e829d80b38
description: This data resource consists of two files: (a) 1x1 km resolution Average Accumulated Exceedance (AAE) data summarising the exceedances of acidity critical loads for eight habitats; (b) 1x1 km resolution AAE data summarising the exceedances of nutrient nitrogen critical loads for thirteen habitats. The data provide information on the amount of excess acid or nitrogen deposition above the critical load values set to protect acid- and nitrogen-sensitive habitats in the UK. The AAE has been calculated using UK 5x5 km Concentration Based Estimated Deposition (CBED) data for 2015-17 (see related data). The data were generated under Defra-funded work to assess the potential areas of acid and nitrogen sensitive habitats at risk of adverse impacts from excess atmospheric acid and nitrogen deposition. Reducing the area and amount of critical load exceedance continues to be a driver of Government policy on reducing emissions of acidic and nitrogen-containing air pollutants (sulphur dioxide, nitrogen oxides and ammonia).
provenance: ProvenanceStatement
  label: Average Accumulated Exceedance (AAE) is calculated at 1x1 km resolution and summarises the exceedance of critical loads of acidity, and of nutrient nitrogen, for multiple habitats. It is derived from the exceedance (i.e. the amount of excess acid or nitrogen deposition above the critical load) for each habitat, the exceeded habitat area and the total acid- or nitrogen-sensitive habitat area in each 1x1 km grid square. For all habitats (except managed woodland) nutrient nitrogen, empirical critical loads have been allocated values based on habitat type and have been defined under the Coordination Centre for Effects (CCE) working group as part of the UNECE Convention on Long-range Transboundary Air Pollution UNECE. (https://wge-cce.org/Publications/Other_CCE_Reports/Review_and_revision_of_empirical_critical_loads_and_dose_response_relationships_2011) . For managed woodlands the steady state mass-balance approach is used where the long-term inputs and outputs of nitrogen from the system are calculated based on nitrogen uptake (removal by harvesting of trees), nitrogen immobilisation, denitrification, and nitrogen leaching. Acidity critical loads are based on the mineralogy and chemistry of the dominant soil type in each 1km grid square together with habitat-specific data. Critical load values are calculated depending on soil type - mineral soils or peat soils. Critical loads for acidity and nutrient nitrogen are compared with deposition data over the UK using three-year rolling mean 5x5 km Concentration Based Estimated Deposition (https://catalogue.ceh.ac.uk/documents/bfa37333-b22e-41b8-829a-10c57d50e13f). By overlaying CBED data of acid or nitrogen deposition on the critical loads data for acidity and nitrogen, exceedance maps can be generated. Simple statistics are further generated to quantify the area of sensitive habitats associated with critical load exceedances. Exceedances are calculated separately for each habitat type using habitat-specific deposition values:…
spatial: Location
temporal: PeriodOfTime
  start date: 2015-01-01
  end date: 2017-12-31
publisher: NERC Environmental Information Data Centre
subject: Pollution
subject: Nutrient Nitrogen
subject: nutrient
subject: nitrogen
subject: acidity
subject: critical load
subject: pollutant deposition
type: Dataset
available: 2021-01-22
landing page: https://doi.org/10.5285/b65abf02-bfdb-4546-a3a3-26e829d80b38
license: OGL-UK-3.0.ttl
rights: RightsStatement
  copyright notice: copyright Crown copyright and database right no limitations
access rights: UNRS
theme: Pollution
distribution:
  access URL: https://data-package.ceh.ac.uk/data/b65abf02-bfdb-4546-a3a3-26e829d80b38
  license: OGL-UK-3.0.ttl
  rights: RightsStatement
    copyright notice: copyright Crown copyright and database right no limitations
  access rights: UNRS
  format: Comma-separated values (CSV)
creator: Rowe, E.C.
language: en

Rowe, E.
type: Person
family name: Rowe
given name: Ed
member: UK Centre for Ecology & Hydrology

NERC Environmental Information Data Centre
type: Organization

Rowe, E.C.
type: Person
family name: Rowe
given name: E.C.
member: UK Centre for Ecology & Hydrology

Pollution
type: Concept

nutrient
type: Concept

nitrogen
type: Concept

acidity
type: Concept

critical load
type: Concept

pollutant deposition
type: Concept

UK Centre for Ecology & Hydrology
type: Organization