The Pearl River Delta Economic Zone is one of the most developed regions in China. It
has been undergoing a rapid urbanization since the reformation and opening of China in 1978. This
process plays a significant impact on the urban environment, particularly river water quality. The main
goal of this present study is to assess the impact of urban activities especially urbanization on river
water quality for the study area. Some Landsat TM images from 2000 were used to map the areas for
different pollution levels of urban river sections for the study area. In addition, an improved equalized
synthetic pollution index method was utilized to assess the field analytical results. The results indicate
that there is a positive correlation between the rapidity of urbanization and the pollution levels of
urban river water. Compared to the rural river water, urban river water was polluted more seriously.
During the urban development process, urbanization and urban activities had a significant negative
impact on the river water quality.