Trends in stream water quality in Environmental Change Network upland catchments: the first 5 years

Hydrochemical data from catchment streams at three Environmental Change Network ECN. upland catchments in north-east Scotland, south-east Scotland and northern England have been subjected to statistical analysis to separate the components due to long-term trend, season and flow. The relative variances due to each are presented for pH, Ca, SO4]S, NO3]N, DOC and Cl. Long-term trends have been identified with increases in concentration for NO3]N and DOC, decreases in SO4]S concentrations, along with short-term seasonal fluctuations. Application of this trend technique has allowed the detection of changes and contributed to an improved understanding of catchment behaviour.