Understanding the watershed characteristics of tributaries of major rivers near Tokyo--Comparison of the Asakawa River, Tamagawa River system and the Ichinokawa River, Arakawa River system-

Abstract

During the period of rapid economic growth, many rivers near Tokyo became heavily polluted due to the influx of domestic wastewater and other contaminants. Today, with the establishment of laws such as the Water Pollution Control Act and the development of sewage systems, water quality in many rivers is showing signs of improvement. However, there are still areas where sewage infrastructure development is lagging, and pollution remains. In this study, we selected two tributary watersheds with similar basin areas from the Tama River and Arakawa River, which are representative major rivers flowing near Tokyo. By conducting water quality observations and comparing the results with previous studies, we examine the changes in water quality and their causes in the tributaries of major rivers near Tokyo.