EXCEPTIONAL WEATHER IN THE MIDLANDS, UK, DURING 1988-1990 RESULTS IN THE RAPID ACIDIFICATION OF AN UPLAND STREAM

Numerous catchment studies have identified the control exerted by hydr ological processes on short-term (within a year) fluctuations in surfa ce water acidity. Because discharge is, in turn, a function of broad c limate parameters, there has been growing interest in the potential im pact of changing precipitation and temperature regimes on water chemis try. The exceptionally warm and arid period 1988-1990 provided an oppo rtunity to investigate the response of an acidic catchment in the East Midlands to an extreme climate scenario. The results obtained from th ree years of intensive monitoring indicated that between 1988 and 1990 there was a fourfold increase of the surface-water acidity at several observation sites within the Beacon catchment, Charnwood Forest, Leic estershire. As well as providing an indication of currently extreme hy drochemical conditions which in the near future may become the norm, t hese observations also have a bearing on the validity of long-term pre dictions derived from process-orientated models.