The present work aims to compare the erosion-vulnerability maps of the sub-basin of the Low (downstream?) Piracicaba watershed, State of São Paulo, using two distinct operators of map algebra as a way of verifying the level of similarity between the products. These operators are called "Zonal Average" and "Zonal Majority" and are compared statistically using an error matrix, which is obtained by cross tabulation, the Kappa index and the linear dispersion coefficient (obtained from the dispersion diagram). The results show that the two maps are very similar to each other and that the analyst may choose either of the two operators.
Zonal average; zonal majority; algebra of map
