WHEN Arab caliphs built their Alhambras in southern Spain centuries ago, they used water and vegetation to transform torrid summers into a climate and surroundings they could bear. During the summer months of Seville's International Exposition in 1992, the same elements the Arabs used - water and vegetation - will be used. Scorching heat is still very much a part of the summer in Andalucia. But the technology will have changed.
Using ``micro'' misters, evaporation, and lots of overhead and surrounding vegetation, Expo officials have found they can reduce summer temperatures.
These commonly top 100 degrees F., even going as high as 118 degrees.
Visitors will walk over porous paving stones cooled by water evaporating from underground streams.
They will walk beneath extensive arbors whose vegetation will be misted to create a cooling but practically imperceptible fog.
More than 350,000 trees and shrubs will be planted in and around the Expo site across from this city, and fountains will bubble, cascade, splash, and crash, to provide a psychological relief from heat.
New techniques for outdoor conditioning, such as low-water use technology, will be demonstrated to the public and to interested professionals through in-depth seminars.
``This is the first experiment of this scale in conditioning large outdoor spaces,'' says Javier de la Puerta, spokesman for the international exposition. ``The idea is to recreate the feeling one gets in the patios and plazas of Seville and Andalucia, but to enhance the result by using new technologies.''