Abstract:

The climatic elements of Yunnan’s 115 stations and 6 representative stations of different climate zones from 1961 to 2018 are used to analyze the spatial and temporal change characteristics of light energy, thermal energy and water resources in the whole province and in each climate zone. The results suggest that: (1) the change of light energy resources mainly show a decreasing trend, and there are considerable mutations, the change of solar radiation in each climate zone may cause the change of the maximum center and minimum center of Yunnan solar radiation, the obvious increase of radiation since 2009 could lead to new change trends and mutation points of solar radiation; (2) the thermal resources are consistently and significantly increased, the active accumulated temperature and duration of accumulated temperature of cool climate crops and thermophilic crops and the length of frost-free period all increase significantly, there is a trend that the beginning date of frost-free period is advanced while the ending date is postponed, which is beneficial to the growth of crops; (3) water resources generally show a decreasing trend, especially since the beginning of this century, warming and drying are prominent in subtropical zones, and the drought risk is high.

Key words: Yunnan, climate zone, agricultural climate resources, climate change