The researchers looked at how water resources are used sustainably in Guangdong Province from 2005 to 2011 using a concept called ecological footprint. They found that every person in Guangdong used less and less water over time. As the economy grew, the amount of water needed for every 104 units of money spent also went down each year. This suggests that efficiency in water usage has improved. Overall, the capacity of the region to handle its water needs was generally good, meaning the water use was sustainable. However, certain areas within Guangdong had higher water usage per person and placed more pressure on the environment. To keep the water usage sustainable, they suggest changing the type of industries and increasing how efficiently water is used.