Abstract:

Understanding the climatic characteristics of flood season precipitation in the headwater region of Minjiang River is crucial for advancing meteorological and hydrological research and ecological conservation in the upstream of the Yangtze River. Based on the tree-ring-revealed precipitation data in Songpan County of Sichuan Province, we investigated the flood season (May-September) precipitation variation from 1901 to 2014 using dendroclimatology and climatological statistics methods. Results indicated that: 1) Tree radial growth and CRU (Climatic Research Unit) data were significantly correlated with flood season precipitation, and precipitation over the past century could be well reconstructed using multiple regression equations as tree-ring data improves CRU data quality. 2) Flood season precipitation contributed about 72% of annual precipitation; the climatic tendency of precipitation was -10.7 mm/century, showing insignificant decrease. 3) Flood season precipitation was stable with no significant abrupt changes over the past century, but with a primary periodicity of 35-37 years and multiple time scale periods of 15-20 and 10-11 years. The research findings offer valuable meteorological information for ecological research and regional development in the headwater region of Minjiang River.

Key words: precipitation characteristics, tree ring, flood season, Songpan, Minjiang River headwater