To describe the Source apportionment approach as a tool for evaluating the contributions of point and diffuse sources to the total riverine nitrogen and phosphorus load per catchment and on a total national basis.
The three objectives were:
To enable the use of the Source apportionment approach to facilitate comparisons with data from previous years; i.e. to enable the application of the source apportionment approach in cases where this approach has been used previously.
To list the type of data to be taken account of, in addition to annual figures on loads of nitrogen and phosphorus from point sources, diffuse sources and natural background losses.