The study looked at how urban development in the Shenzhen River Basin affects the flow of water in the river. Using data from 1988 to 2006, researchers found that as more land was turned into buildings, the amount of wastewater increased significantly. This led to more natural runoff in the river each year, especially after 1993. The way land was used also played a role in increasing runoff, but heavy rain could lessen this effect. Overall, rainfall was the main factor influencing the amount of water flowing in the river, but urbanization and population growth also had an impact.