Host: The Association of Japanese Geographers
Name : Annual Meeting of the Association of Japanese Geographers, Autumn 2023
Date : September 16, 2023 - September 19, 2023
The water quality of rivers in Japan has improved due to the implementation of water pollution prevention laws and the development of sewage systems. However, the discharge of wastewater from sewage treatment plants, which collect sewage, can potentially cause point source pollution in rivers. It has been pointed out that inadequate treatment of sewage in treatment plants can lead to the inflow of nutrients such as organic matter, nitrogen, and phosphorus into rivers, which depletes oxygen in the water and affects the river's ecosystem. However, it is not clear how the water quality of rivers changes when the inflow of wastewater from treatment plants stops and how long it takes for the effects to diminish. To investigate the changes in river water quality when the discharge from sewage treatment plants is stopped, it is necessary to conduct continuous surveys during both the period with inflow from the treatment plants and the period without inflow. This study aims to examine the effects of sewage treatment plant discharge on the water quality of the Yamada River in Hachioji City, Tokyo, and to elucidate the changes that occur when the discharge is eliminated.