Spatial and Temporal Variations of Climate on Different Flanks and Elevations in the Qinling-Daba Mountains of China from 1969 to 2018

Climate change presents great variations on different flanks and elevations in the same mountain range. Analysis of the spatial and temporal variations of climate on different flanks and elevations in the north-south transition zone--the Qinling-Daba Mountains (QDM) are of great significance for exploring the complexity of climate geography pattern and phenology in China. This paper collected 118 weather stations data on daily temperature and precipitation during 1969-2018 from the National Meteorological Information Center, and then explored the temporal and spatial distribution characteristics of climate on different flanks and elevations. The results showed that: 1) On the whole, there was a significant warming trend in the four seasons in the past 50 years. Precipitation did not show significant variation at most stations with an exception to 8 weather stations having significant changes in trend in different seasons. 2) The temperature showed an increasing trend in different seasons, but its increasing rate varied greatly on different flanks. Generally speaking, climate change was greater on the northern flanks than that on the southern flanks in the four seasons in the QDM. Temperature tendency is greater in spring and winter than in summer and autumn on different flanks in the QDM. 3) The increase rate of temperature varied greatly at different elevations in different seasons. The warming rate was greater in the higher altitude regions than that of the lower altitude regions in summer, autumn and winter, while, in spring, however, it is higher in the lower altitudes than in the higher altitudes.