Abstract:

Drought is the most important agrometeorological disaster in the process of summer maize production in Puyang area. It is of great significance to clarify the evolution law of agricultural drought occurrence for taking effective disaster prevention and mitigation measures. Using the monthly temperature and precipitation of 5 meteorological stations in Puyang from 1991 to 2020, standardized precipitation evapotranspiration index (SPEI) and wavelet analysis and Mann-Kendall test were used to analyze the characteristics of drought change in the summer corn growing season (June-September) in Puyang. The results showed that the incidence of drought in summer maize seedling stage was 26.7%, and it showed a trend of drought after 2010. The abrupt climate change occurred in 1992, 1995 and 2005, and the climate of summer maize seedling stage showed a periodic change of dry and wet of 8-9a and 20-25a. The incidence of drought in the ear period of summer maize was 30.3%, and the climate changed abruptly in 2018, and the climate in the ear period showed dry and wet periodic changes of 6-10a and 15-25a. The incidence of drought in the summer corn grain period was 35%, the climate abrupt change occurred in 1992, 1998, 2002 and 2018, and the climate in the flower grain period showed periodic changes of dry and wet of 5a, 10a and 18-24A. The incidence of drought in the whole growing season of summer maize was 32.3%, climate abrupt change occurred in 2010, 2015 and 2019, and the climate of summer maize during the whole growing period showed dry and wet periodic changes of 8 to 9a and 22a. Due to the abnormal climate, the cyclical changes of dry and wet become weaker after 2010, showing a trend of drying, and there is a risk of abrupt change in dry and wet conditions. Therefore, it is necessary to strengthen monitoring, early warning, forecasting and defense work in the production process of summer maize.

Key words: Puyang, summer maize, SPEI, drought