This data-set relates to two studies on lead concentration in moss samples, in micrograms per gram dry weight, collected in Galicia, norther Spain. The data are from two surveys, one conducted in October 1997 and on in July 2000. The variables are as follows:
x x-coordinate of the spatial locations.
y y-coordinate of the spatial locations.
lead lead concentration.
survey year of the survey (either 1997 or 2000).
data(galicia)
A data frame with 195 rows and 4 variables