Daily-scale gridded analysis of spatiotemporal characteristics in agricultural drought events across winter wheat growth stages in the Huang–Huai–Hai Plain, China

Drought is a common and recurring natural disaster that poses a serious threat to winter wheat in the Huang-Huai-Hai Plain (HHHP), China. However, a comprehensive understanding of drought characteristics across different growth stages of winter wheat remains limited in the HHHP. This study employed a daily-scale agriculture drought index to identify drought events, analyzed the spatiotemporal patterns of drought frequency, duration, intensity, and combined attributes, and elucidated the underlying drivers of drought trends. Results revealed significant spatiotemporal heterogeneity in the characteristics of drought events. In the northern part of the study area, drought events persisted for a longer duration, whereas the southern part was subject to drought events with greater intensity. During the period 1980–2023, drought conditions across the study area showed an overall alleviation trend, yet with pronounced spatial heterogeneity. Drought moderated in the northern part, while aggravated in the southern part. The spatial variability of drought trends was mainly attributed to the impacts of climatic factors on soil moisture. Increased precipitation and reduced evaporation dominated in the northern part of the study area, whereas enhanced evaporation dominated in most southern regions. Furthermore, drought trends varied across different growth stages of winter wheat, with drought alleviation being particularly pronounced during the green-jointing, heading-flowering, and filling-maturity stages. These findings provide valuable insights for optimizing precision agricultural water allocation and climate adaptation strategies to ensure food security in the HHHP. • A daily scale drought index was used to identify agricultural drought events. • Drought events lasted longer in the north but were more intense in the south. • Drought moderated in the northern part, while aggravated in the southern part. • The key climatic factor influencing the drought trends has been detected.