摘要：The yearly and daily changes in the quality of water in the moat around the Imperial Palace were examined to find a relationship, if any, between water quality and horizontal insolation intensity (H.I.I.). The sampling station for the daily survey was placed at the moat of Hibiya Bori ([○!A]), and the following results were obtained. 1) Quality of the water in the moat is eutroph, and yearly progressive pollution was not recognized. 2) The horizontal insolation intensity is related to dessolved oxygen in the Hibiya Bori in summer (August 21, 1970).
