THE ESTIMATION OF AERIAL INPUTS OF METALS TO ESTUARINE WATERS FROM POINT PATTERN DATA USING AN ISOPLETHING TECHNIQUE - SEVERN ESTUARY, UK

The aerial deposition of Cd, Cr, Cu, Ni, Pb and Zn to the tidal surfac e of the Severn Estuary in southwest Britain was determined using the nonlinear isoplething of point data from 11 bulk-deposition sampling s tations operated between January 1989 and March 1990. Previous surveys based on crude spatial bulking of deposition data from coastal sites had generated overestimates of aerial deposition of metals. The distri bution of aerial deposition away from the dominant source around Avonm outh was related to weather variables. Down-estuary deposition gradien ts were steepest in wet westerly on-shore airflows.