Resumen
Using a network of 16 urban/suburban and rural pan evaporation (pe) stations in Mexico City and its environs, an attempt is made to assess the comparative evaporative characteristics of different areas in a large city located in an elevated inland valley in the tropics. Significant parallel increases in pan evaporation and heat island intensity have been observed in the central and western portions of Mexico City for the period 1967-88. It is suggested that pan evaporation increase is linked to the observed increase in the intensity of the heat island related to the accelerated urbanization of the capital City. m contrast over the eastern suburbs the establishment of a large (9500 Ha) adjacent revegetation project has apparently influenced pan evaporation to decline in spite of the increasing presence of the heat island. Association of pan evaporation to other climatic elements such as insolation, precipitation and wind velocity is also explored.