Abstract:

Based on daily ground meteorological observation data from 101 meteorological stations, historical disaster data, and maize production data in Xinjiang from 1961 to 2020, this study clarified the spatiotemporal characteristics of high temperature heat damage during the maize flowering stage under the background of climate change by using linear trend analysis and spatial interpolation analysis methods. At the pentad scale, it further revealed the changing patterns of such heat damage during different periods in southern and northern Xinjiang, aiming to provide a reference for maize production management and agrometeorological services in Xinjiang. The results showed that: (1) from 1961 to 2020, moderate high temperature heat damage was the dominant type during the maize flowering stage in Xinjiang, followed by light heat damage, exhibiting a spatial distribution pattern of higher occurrence in the east and lower in the west. Regions with a heat damage frequency exceeding 60% were mainly concentrated in western Changji Hui Autonomous prefecture in northern Xinjiang and central Bayingolin Mongol Autonomous prefecture in southern Xinjiang. (2) High temperature heat damage during the maize flowering stage in Xinjiang showed an interdecadal intensification trend. In the 2010s, the total frequency of heat damage events of all levels increased by 6.6 pp compared to the 1960s. Both the station ratio and the number of occurrence days showed an increasing trend in southern and northern Xinjiang, with a greater rate of increase observed in northern Xinjiang than in southern Xinjiang. (3) The widest spatial extent of heat damage occurred during the 4^th pentad in July in both southern and northern Xinjiang, with station ratios of 36.0% and 27.0%, respectively. Compared to period I (1961−1990), the pentad-based station ratio of heat damage during the maize flowering stage in Xinjiang generally increased during period II (1991−2020), and the pentad with the highest station ratio showed a trend of occurring earlier.

Key words: Maize flowering stage, High temperature heat damage, Pentad scale, Spatiotemporal variation, Trend analysis