Freshwater Umbrella Research

Critical loads in freshwater ecosystems and nitrogen (CLAG3)

April 1995 - March 1998

Project Summary

CLAG3 ran from June 1995 through May 1998 and made the following key achievements:

  1. the development of a high quality national chemical database for model verification and national critical loads mapping;
  2. the development and application of the FAB model for national critical loads mapping;
  3. the development of a dynamic modelling capability at a range of spatial scales from headwater catchments to the whole of the United Kingdon using the MAGIC, MAGIC-WAND, and MAGIC 7 models. This dynamic modelling approach offers key evidence on the timing of recovery in response to emission reductions, and provides the capability to consider other factors such as land use and climate change;
  4. the production of new assessments of freshwater acidification in the United Kingdom using the FAB and MAGIC-WAND models;
  5. the further development of high quality chemistry-biology datasets and the associated developments in biological modelling;
  6. the development and application of new approaches for identifying restoration targets for acidified ecosystems using the palaeolimnological record;
  7. the establishment of strong working links and collaborations within the freshwaters critical loads group;
  8. the organisation of two international workshops on key themes relating to critical loads in freshwater - the role of nitrogen (11th September 1997) and the prospects for recovery (9th January 1998).

The detailed results of this research programme were outlined in 26 separate papers and reports.

Project Reports

  • Curtis C.J., Harriman R., Allott T.E.H. and Kernan M. (1998) Water chemistry and critical load modelling at a network of moorland lake and reservoir sites in the British uplands: Two year data report (1996-97).. ECRC Research Report No. 50, ECRC, University College London, London, UK 181pp.
  • Allott T.E.H., Curtis C.J., Evans C., Harriman R., Jenkins A., Juggins S., Kernan M.R., Ormerod S. and Patrick, S.T. (1998) Critical Loads in Freshwater Ecosystems (1995-1998). A Summary Report to the Department of the Environment, Transport and the Regions Contract No. EPG 1/3/51.. ECRC Research Report No. 51, ECRC, University College London, London, UK.