Part V Critical Loads

Water, Air, and Soil Pollution

, Volume 85, Issue 4, pp 2503-2508

First online:

Estimating uncertainty in the current critical loads exceedance models

  • R. I. SmithAffiliated withInstitute of Terrestrial Ecology, Edinburgh Research Station
  • , J. R. HallAffiliated withInstitute of Terrestrial Ecology, Monks Wood
  • , D. C. HowardAffiliated withInstitute of Terrestrial Ecology, Merlewood Research Station

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The critical loads approach to quantifying areas at risk of damage requires deposition and critical loads data at the same spatial scale to calculate exceedance. While maps of critical loads for soil acidification are available at a 1 km scale no monitoring networks in Europe measure wet and dry inputs at this scale and, further, the models currently used to estimate deposition incorporate a number of assumptions which are not valid at the 1 km scale. Simulations of 1 km deposition from 20 km data show that the uncertainty introduced by using 20 km scale estimates of deposition is small, except in mountain areas where it can give misleading results, but a major problem is the uncertainty in estimates of deposition at the 20 km scale produced by the current models.

Key words

critical load deposition model spatial scale uncertainty probability distribution