Novel water facilities for creation of comfortable urban micrometeorology

The cooling effects of artificial water facilities - fountains, waterfalls and urban canals - have not received much attention. To improve the meso-sp ace thermal environment in an urban area, especially that during the midsum mer, we propose using novel artificial water facilities to alter the temper ature and humidity, so as to improve pedestrian comfort. To study this, we have carried out field measurements and wind tunnel tests, and we report th e results in this paper. At first we made measurements of wind velocity, te mperature and humidity around such artificial water facilities in Tennoji P ark in Osaka city (a typical Japanese large city). The results showed reduc ed temperatures on the leeward side, and demonstrated the usefulness of wat er facilities in improving the thermal environment. Also, we constructed an insulated 1/400 scale wind tunnel model of the situation and measured, by means of X-type hot wire anemometer, the air currents on the wind tunnel su rfaces in urban, suburban and rural terrains. We also measured, using fine- gauge T-type thermocouples, the air temperature distribution in front of an d behind the model of the water facility. The results confirmed the qualita tive ranges of the cooling effect provided by the actual water facilities. In particular, the cooling effect produced by a 1.0 mm diameter nozzle foun tain was found to extend a distance downstream equal to ten times the heigh t of spout. (C) 1998 Published by Elsevier Science Ltd. All rights reserved .