The estimation of aerial inputs of metals to estuarine waters from point pattern data using an isoplething technique: Severn Estuary, U.K.

The aerial deposition of Cd, Cr, Cu, Ni, Pb and Zn to the tidal surface of the Severn Estuary in southwest Britain was determined using the nonlinear isoplething of point data from 11 bulk-deposition sampling stations 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 distribution of aerial deposition away from the dominant source around Avonmouth was related to weather variables. Down-estuary deposition gradients were steepest in wet westerly on-shore airflows.