The study analyzed water quality in the Luanhe River from 2007 to 2011. It found that pollutant levels were lower in the dry season and higher in the normal water season in 2010. Overall, water quality improved during this period. The researchers also discovered that water quality in certain areas was good with small amounts of water but poor with large quantities, indicating non-point source pollution. Conversely, in another area, water quality was good with large quantities of water but poor with small amounts, suggesting point source pollution.