The researchers studied China's precipitation patterns from 1957 to 2004. They looked at how much it rained each year, how often it rained, and how heavy the rain was. They found that heavy rain amounts have increased, affecting total rainfall. Changes in how often it rains have a bigger impact on overall rainfall than changes in rain intensity. Different regions in China show varying trends in rainfall patterns. Overall, the researchers discovered that changes in how often it rains are the main reason for shifts in precipitation patterns.