A river has a good effect on the micro-climate of surrounding areas when natural cooling winds are needed in the hot summer season in Japan. In order to clarify the effective arrangement of buildings around the river, wind tunnel experiments were conducted. The water channel in the wind tunnel is 2000 mm long and 200 mm wide in full scale. The effects of the body of water were detected through analysis of the humidity distribution around it. The results suggest that the location and direction to wind of buildings are important, as well as the building density around the water surface.
