西藏地区一种新的四季划分方法OA北大核心CSTPCD

This study evaluates the applicability of common climatic seasonal division methods in Tibet of China,utilizing daily temperature data from 38 meteorological stations spanning from 1981 to 2022.The analysis high-lights the limitations of various seasonal division approaches and emphasizes the suitability of Tibetan phenologi-cal and growing season division methods for agricultural activities in Plateau region of Tibet.Temperature thresh-olds for seasonal division were determined based on Tibetan phenology and the main crops'growing periods.The research reveals that:(1)While general methods for climatic season division exhibit certain limitations in Tibet,the Tibetan phenological and growing season division methods align well with agricultural requirements.(2)Employing temperature thresholds of"6℃,15℃","5℃,16℃","6℃,16℃",and"6℃,17℃",the study analyzes the variation in the lengths of the four seasons at typical weather stations.Gerze experiences a longer winter,while Zayu has a prolonged summer.In Lhasa,Qamdo,Gerze,and Zayu stations,summer durations have extended,whereas autumn and winter have contracted.(3)Mutation tests indicate that the average summer tem-peratures at Lhasa and Qamdo stations underwent significant changes in 2011 and 2017,respectively,supporting the use of 17℃as the summer threshold.(4)The newly proposed four-season division method for Tibet,charac-terized by the"6℃,17℃"index,demonstrates a distribution pattern of weather stations mainly along the lower elevation areas of the Yarlung Tsangpo River Line during summer.Spring and autumn durations are shorter in the northwest and south,and longer in the central and eastern regions.Conversely,summer is extended in the central areas and reduced in the peripheral regions,with the opposite pattern observed for winter,spring,and autumn.This spatiotemporal distribution aligns with Tibet's climatic reality.The average onset dates for spring,summer,autumn,and winter are March 21,June 16,July 25,and November 3,respectively.