Influence of Geographic Elements on the Beginning of Four Seasons in Northeast China for the Period of 1981-2020
Geographical elements such as longitude,latitude,and altitude have direct effect on the start time of four seasons;however,the extent and nature of the influences,and the variability in the extent on which the same geographical element affects different seasons,had not yet been revealed,particularly for Northeast China,where the rising temperature with prolonged/shortened seasons have been significantly changing the structure of forestry for years.In this study,based on original the records of daily mean temperature of 1981-2020 collected at 27 meteorological stations established over northeast China,it used a pentad mean temperature method to calculate the start time of four seasons,and then their spatio-temporal distribution subjected to geographical elements was addressed by partial correlation analysis.(1)In Northeast China,the beginning dates in spring and summer was positively correlated with altitude,but the dates in autumn and winter was negatively correlated with altitude.The beginning date in spring was positively correlated with latitude,but the dates in autumn and winter was negatively correlated with latitude.The beginning date of spring and summer was positively with longitude,but the date in winter was negatively correlated with longitude.(2)Longitude,latitude,and altitude had different impacts on the start of four seasons.The beginning date of spring was influenced most by altitude,second by latitude,and least by longitude.The beginning date of summer was influenced most by altitude,followed by longitude.The beginning date of autumn was influenced most by latitude,followed by altitude.The beginning date of winter was influenced most by latitude,second by altitude,and least by longitude.(3)Longitude,latitude,and altitude generally had different effects on the start of four seasons,with winter being the most affected,followed by spring,and to a lesser extent summer and fall.This study identified the start time of four seasons with associated influencing facts in Northeast China,which would provide a scientific guidance for local crop seed selection and site selection,to promote the development of agriculture and economy.
beginning dates of seasonsaltitudelongitudelatitudepartial correlation coefficient
NETL
NSTL
万方数据
