Comparing land cover products CLC2000 and MOD12Q1 for Portugal.

In this study we compared two important land cover maps, the CORINE Land Cover 2000 and the MODIS Land Cover, over the Portuguese mainland territory with the objective of understanding the main similarities and differences between the two. To make this comparison possible we had to first harmonize their differences by using conversion and generalization techniques in conjunction with conceptual studies. The comparison was based on simple statistical analysis. Results showed an agreement value of 50% using a direct relationship of the nomenclatures of CLC2000 and MOD12Q1 and a value of 53% using a generalised nomenclature of 9 classes. These results indicate many inconsistencies between the MOD12Q1 and CLC2000 product. A large number of these inconsistencies are due to errors in both databases. We can say with confidence that these two land cover products show two different “Portugals”.