The researchers studied water use in Guangxi from 2003 to 2011 using an ecological footprint model. They found that water resources in Guangxi are being used sustainably, with high safety levels. Over the years, the surplus of water has increased while the ecological pressure has decreased. This shows that water is being used efficiently in the region, even though there's still room for improvement compared to the national average. The study suggests that further research is needed to improve how we measure water pollution and its impact on water resources.