The use of catchment attributes to predict surface water critical loads: A preliminary analysis

Abstract

Current applications of the critical loads concept are geared primarily towards targeting emission control strategies at a regional and international level. Freshwater critical maps in the UK have been produced at a resolution of 10 km grid squares and do not take into account variations of water chemistry within the mapping unit. They are therefore of limited use at the catchment scale. This paper assesses the potential for the development ofn empirical statistical model to predict catchment critical loads using readily available secondary data. Multivariate statistical analysis of existing critical loads chemistry data together with data obtained from the Institute of Terrestrial Ecology (ITE) identifies strong relationships between surface water chemistry composition and a variety of site-specific catchment attributes, particularly rainfall, altitude and site sensitivity. Although there were problems with the data used, particulaly in terms of noise, collinearity and spatial resolution, the strength of the relationships indicates that accurate prediction of catchment scale critical loads should be possible using a higher resolution, catchment specific dataset.