Six countries stand out with ratios significantly over the OECD average. Of these, Mexico, Italy, and Japan are also relatively large users. Portugal also presents important irrigation intensity, but without specific information for "groundwater irrigation area", not being the reference values (national statistics) comparable to the present study.15 The United States, Turkey, Greece, Spain and Australia, on the other hand, despite being among the largest users, have a groundwater irrigation intensity under the estimated OECD average of 5 194 m3/ha in 2010.