Critical loads for soils and freshwaters; a comparison methods at the Plynlimon catchments
International agreements aimed at reducing sulphur deposition from the atmosphere are now focused on the 'critical loads' concept. This provides a distributed link between sources and receptors of acidic oxides and also links the level of reduction with biological recovery. Methods for cal...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
1997-01-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | http://www.hydrol-earth-syst-sci.net/1/729/1997/hess-1-729-1997.pdf |
| Summary: | International agreements aimed at reducing sulphur deposition from the atmosphere are now focused on the 'critical loads' concept. This provides a distributed link between sources and receptors of acidic oxides and also links the level of reduction with biological recovery. Methods for calculating critical loads include simple classification (Level 0), mass-balance equilibrium models (Level 1) and dynamic hydrochemical models (Level 2). Here, examples of each method are applied to headwater catchments in Plynlimon, mid-Wales. The critical loads derived are compared and the utility of the critical loads concept as a tool for local pollution control and land management is assessed. <br>Differences in critical load methods for soils result from assumptions regarding biological receptors. Surface water critical loads are generally similar under all methods. As a local management tool, the dynamic model is most appropriate although it has a high data requirement. The utility of other methods depends upon detailed maps of soil and vegetation being available at an appropriate scale. |
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| ISSN: | 1027-5606 1607-7938 |