The study looked at heavy rainfall patterns over the Tibetan Plateau from 1961 to 2008. They found that heavy rainfall decreases from southeast to northwest during the summer, and from the east to the surrounding areas during the winter. Heavy rainfall during the summer has cycles of about 3, 6, and 10-11 years, while in winter it has cycles of about 6-7 and 15 years. The trend of heavy rainfall varies across the Plateau, with a weak decrease in summer and an increase in the Yarlung Zangbo River area in winter. There was a sudden change in rainfall patterns in 1976.