Characteristics of Changes in Sichuan Province Climate Annual Index from 1990 to 2022

Deng Biao; Sun Rui; Cai Yiheng

doi:10.16765/j.cnki.1673-7148.2025.06.002

Abstract：Based on the temperature and precipitation data and climate annual index from the Na-tional Meteorological Observatory of Sichuan Province from 1990 to 2022,the variation characteristics of the climate annual index in Sichuan Province are studied by the methods such as percentile method,rota-tional empirical orthogonal function,and linear trend equation.The results show that:(1)There is a sig-nificant difference in the average state of climate annual index in various regions of Sichuan Province.Aba Prefecture and most of the basin have higher values of climate annual index,with the central part of the basin being the center of the high values,while Ganzi Prefecture and Panxi(Panzhihua and Xichang)region have relatively lower values.(2)The climate annual index of Sichuan Province has shown a significant increasing trend in the past 33 years,with a clear deviation trend in the annual evalu-ation level.The preferred annual sceneries all appeared before 2010,and the deviation annual scenes mostly appeared in the past 20 years.The climate annual index in the western part of the basin and the northern part of the western Sichuan Plateau shows a significant increasing trend,and the annual climate may become worse and worse.(3)The regional characteristics of the climate annual index changes in Si-chuan Province are mainly divided into southern basin type,western basin type,central basin type,and Panxi type.The climate annual index of the western basin and Panxi regions has shown a significant in-creasing trend,with frequent deviations since the beginning of the 21st century;the southern and central parts of the basin exhibit weak growth or inconspicuous changes.(4)The quantitative evaluation results of the annual climate of Sichuan Province are consistent with the observation evaluation.The climate an-nual index has a good representational ability for climate abnormal events,but it is negatively correlated to the magnitude of disaster loss rate and shows an opposite trend of change,which needs to be consid-ered comprehensively in actual operations.