Seasonal Variation of the Suspended Solid Matter, off the Coast of North Yorkshire

Abstract

An investigation into the natural regime of coastal suspended solids before discharge of potash mining waste is described. Regular samples of suspended material were taken over the period September 1968 to August 1970. Statistical analyses showed significant differences in suspended solid values between the months and between inshore and offshore sampling stations. There was no significant difference between sampling points along the coast. The inshore suspended solid values were low from May to September. At other months and at the offshore stations there was a gradual change from summer (low) to winter (high) values and vice versa.Sea temperature, sea state, tidal range and river flow correlated significantly with suspended solid values. It is suggested that wave action, tidal currents and river flow control most of the variation in load of suspended matter off the N. Yorkshire coast. The significant negative correlation between temperature and suspended solid values is not regarded as a causal relationship. Low temperatures are associated with high wave activity and high river flow rates; factors which are more likely to have a causal relationship with suspended solid loads than temperature. Thus, suspended matter variations off the Yorkshire coast are probably determined by physical rather than biological temperature-dependent processes.From multiple linear regression analyses, sea state, tidal range and river flow were found to account for 64·1% of the variation of the inshore suspended solid values and 52·4% of the variation of offshore values. Using the multiple regression equations as mathematical models it was possible to derive accurate predictions of the natural suspended solid load.