The researchers analyzed water quality in the Hanjiang River basin to understand changes and factors influencing it. They found that the main stream had good water quality, but some sections had lower quality. Total phosphorus and nitrogen levels were high in certain areas. Water quality varied between seasons and different river sections. Stations were grouped into upstream, middle, and downstream categories based on water quality. Protection measures at Xiaohe station improved water quality there. Water discharge and temperature were key factors affecting water quality in the river.