| Autor: |
B. F. Pain, K. R. Bull, C. J. Place, Helen ApSimon, Michael Hornung, R. J. Singles, Bridget A. Emmett, David Fowler, V. C. Phillips, R. Harrison, Ulrike Dragosits, C. A. Ross, Ron Smith, J. Hill, D. Moss, J. Ullyett, David S. Lee, C. Milford, S. C. Jarvis, Mark A. Sutton, C.E.R. Pitcairn, S. E. Espenhahn, G. P. Wyers, J. Webb, Ross A. Hill, Jason Lowe |
| Rok vydání: |
1998 |
| Předmět: |
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| Zdroj: |
Environmental Pollution. 102:349-361 |
| ISSN: |
0269-7491 |
| DOI: |
10.1016/s0269-7491(98)80054-7 |
| Popis: |
Ammonia is a reactive pollutant emitted primarily by agricultural sources near ground level in the rural environment. The consequence of these factors is that, in addition to the effects of long-range pollutant transport, ammonia has major effects at a local scale, with emission and receptor areas often closely located in the rural landscape. There is a substantial local spatial variability that needs to be considered in effects assessments, while variations in local deposition may affect the amount of ammonia available for impacts further afield. The wide-ranging UK programme ADEPT (Ammonia Distribution and Effects ProjecT) has addressed these issues through a combination of measurement and modelling activities concerning the distribution of emissions, atmospheric transport, deposition and effects assessment. The results are illustrated here by summarizing the findings of a joint experiment at Burrington Moor, Devon, and wider modelling contrasting the variability at a field scale with 5 km resolution estimates for the UK. The fraction of emitted NH3 deposited locally is shown to depend critically on the downwind land-cover, with fluxes being dependent on interactions with the ammonia compensation point. This will restrict deposition back to agricultural land, but may mean that non-conservation woodlands could be of benefit to recapture a significant fraction of emissions. The generalized models demonstrate the high spatial variability of ammonia impacts, with a case study being used to show the consequences at a field scale. In source regions substantial variability occurs at sub-1 km levels and this will have major consequences for the emission reduction targets needed to protect ecosystems. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect