Hydrogeographical Study on Water Quality of Asakawa River in Tamagawa River System (4)

Abstract

In the Asakawa River of the Tama River system, there are issues such as pollution caused by domestic wastewater. In order to understand the water quality and characteristics of the basin, not only field surveys but also comprehensive studies that combine various methods are required. The purpose of this study is to clarify the basin characteristics of the Asakawa River through the results of field surveys, water quality analysis, and statistical analysis using the results.From this study, four issues were identified in the Asakawa River basin: the delay in the installation of municipal combined septic tanks in the upper reaches of the river and the pollution caused by septic tank effluent; the outflow of nitrate due to nitrogen saturation in the forest ecosystem in the upper reaches; the pollution caused by the inflow of effluent from the Kitano Sewage Treatment Plant into the Yamada River; and the pollution caused by domestic wastewater from the Yudono River basin. In order to solve these problems, the maintenance of the watershed environment is required.