| A method for examining the impacts of disturbance on stream
water quality based on paired catchment “control�? and
“response�? water quality time series is described in relation to
diagrams of cumulative flux and cumulative flux difference. The paper describes
the equations used and illustrates the patterns expected for idealised flux
changes followed by an application to stream water quality data for a spruce
forested catchment, the Hore, subjected to clear fell. The water quality
determinands examined are sodium, chloride, nitrate, calcium and acid
neutralisation capacity. The anticipated effects of felling are shown in
relation to reduction in mist capture and nitrate release with felling as well
as to the influence of weathering and cation exchange mechanisms, but in a much
clearer way than observed previously using other approaches.
Keywords: Plynlimon, stream, Hore, acid neutralisation capacity, calcium,
chloride, nitrate, sodium, cumulative flux, flux |