Space-time Distribution of High Temperature Disasters on Single-cropping Rice during Heading-flowering Stage and Filling-harvest Stage in Sichuan Province
In this paper, spatial-temporal variation characteristics of high temperature disasters on single-cropping rice during heading-flowering stage and filling-harvest stage were analyzed with agricultural data including meteorology, rice production and agro-meteorology from 1961 to 2014 in Sichuan province by linear regression, multiple regression, Morlet wavelet analysis. The results showed that the total and different grades of high temperature disaster occurrence times were a significant upward trend from 1961 to 2014, especially after 2000. The mild heat damage increased significantly during heading-flowering stage, and the severe heat damage increased significantly during filling-harvest stage. The different grades of high temperature disaster occurrence times showed a significant periodic oscillation during growth period on 16 years, 12 years, 4 years time scale. Based on periodic changes speculated, it will remain high temperature disaster in 2015. The distribution of heat injury spatial pattern showed "less in mountainous and multi in basin". Rice planting area can be divided into: high temperature disaster often occurred in central plain area and southern hilly of basin, seldom happen in eastern hilly of basin, less happened in southwest mountain. Under the background of climate warming, the frequency of different grades of high temperature disaster has increased, and frequent center has expanded from the plains to the mountain since 1990. This study has realized the transition of high temperature disasters monitoring products which from qualitative to quantitative. It combined the dynamic monitoring, improved the accuracy of the spatial distribution, and extended timeliness of the study.