Abstract:

Climate warming has significantly changed the thermal resources in Inner Mongolia, and understanding thermal resource changes in this region can provide a research basis for crop production and spatial layout. Based on the daily average temperature of 50 meteorological stations from 1959 to 2018, this paper discussed space-temporal distribution characteristics of the initial day, ending day and duration days≥0℃ and ≥10℃, as well as cumulative temperature in Inner Mongolia by adopting five-day sliding average method. The results indicated that: (1) the average initial day ≥0℃ and ≥10℃ in Inner Mongolia was March 29, and May 5, respectively, the initial day ≥0℃ and ≥10℃ showed an ahead of time trend, the average ending day≥0℃ and ≥10℃ was October 28 and September 24, respectively; (2) the advance of the initial day and the delay of the ending day significantly increased the cumulative temperature and the duration days in Inner Mongolia, the cumulative temperature and duration days were similar in spatial distribution, and were different greatly between east and west; the cumulative temperature ≥0℃ was between 1874 and 4433℃, and the cumulative temperature≥10℃ was between 1360 and 4024℃,duration days ≥0℃ were between 168 and 246, and duration days ≥10℃ were between 89 and 180; the cumulative temperature and duration days ≥0℃ and≥10℃ showed an increasing trend; (3) the initial day ≥0℃ and ≥10℃ showed a positive correlation with latitude and longitude, the ending day, while the cumulative temperature and duration days showed a negative correlation with latitude and longitude; (4) the mutation date of the initial day, the ending day and duration days, as well as that of the cumulative temperature mainly focused between 1991 and 1996.

Key words: Inner Mongolia, thermal resources, cumulative temperature, initial day, duration days