Abstract
The effect on the recreational activity of promoting the water environment improvement of Lake Biwa was quantitatively examined. A questionnairing for the people of Lake Biwa and the Yodo River basin was carried out. Willingness to pay of a visit to Lake Biwa before and after the improvement of aqueous environment was 507 yen and 721 yen, respectively. It was shown that the effect of water environment improvement of Lake Biwa was geographically very wide. It was also evaluated that the population where people would like to visit Lake Biwa increases at approximately 4 times. It was pointed out that the effect of water environment improvement of Lake Biwa on the behavior of people would be very wide in the basin.
