Abstract: Understanding the temporal and spatial characteristics and hazard of waterlogging for rape during the sowing stage is beneficial to enhance the climate adaptation of rape planting, and provide theoretical basis for planting structure adjustment, the formulation of agriculture policy, disaster prevention and reduction. Based on the meteorological data of every ten-day of 105 meteorological stations in Sichuan Basin, the observation data of rape production and agricultural statistics, we analyzed the temporal and spatial variations of waterlogging index, slight/moderate waterlogging frequency and hazard of waterlogging for rape during sowing stage of four decades from 1981 to 2020 by significance test and geographic information technology. The results showed that average value of waterlogging index ranged from 0.12 to 0.56 in the past four decades, with obvious differences in different decades and planting areas of rape. In each decade, the frequency of moderate waterlogging was higher than that of slight waterlogging. The average and maximum of hazard indices were at the lowest level between 1991 and 2000. Spatially, the hazard indices were higher in the southern basin and the region around the basin, but lower in the western and eastern basin. The results are consistent with the trend of climate change in Sichuan Basin and the spatiotemporal characteristics of disasters. In the regions with serious waterlogging damage and large planting area, we should popularize the technique of raising seedlings and transplanting and waterlogging-tolerant variety to reduce waterlogging damage.

Key words: rape, sowing stage, waterlogging, temporal and spatial characteristics, Sichuan Basin.