Understanding climate variability and its impact on drought occurrences in maize producing regions: Evidence from north of China

Global warming is projected to increase future droughts that will have a significant impact on maize cultivation in China. Therefore, we studied the changing climate patters and its impact during the maize growth period (MGP) using the downscaled outputs from the Coupled Model Intercomparison Project Phase 6 (CMIP6) under two Shared Socioeconomic Pathways (SSP245 and SSP585) for the future period in three timelines (2020–2039; 2040–2069; and 2070–2099) relative to the baseline period (1981–2014). The Standardized Precipitation Evapotranspiration Index (SPEI) was calculated on monthly, 3-monthly, and 6-monthly timescales to monitor the short and long-term future drought conditions during the MGP in the north of China. Our results show an increase of mean temperature by 0.63–1.90 °C, 0.85–2.13 °C, and 1.21–2.42 °C under SSP245 and 1.42–2.76 °C, 1.84–3.07 °C, and 2.01–3.57 °C under SSP585 in 2030 s, 2060 s, and 2090 s across the region during MGP. The precipitation during MGP is projected to increase from 22.71–97.14 mm and 29.92–98.40 mm from 2030 s to 2090 s under SSP245 and SSP585, respectively, relative to the base period. Our results also indicate regional variations in drought occurrences, with Northwestern Arid Region (NWAR), Inner Mongolia Region (IMR), and Northeast China (NEC) experiencing differing degrees of drought intensity. The duration of mild droughts is projected to increase by 5.6 %–8.5 % (SSP245) and 5.7 %–9.2 % (SSP585) and moderate droughts are expected to rise by 3.8 %–8.8 % (SSP245) and 4.2 %–9.9 % (SSP585). In the NWAR, mild droughts are projected to increase by 24.3 %–30.5 % (SSP245) and 27.2 %–33.3 % (SSP585) and moderate droughts increasing by 13.1 %–25.6 % (SSP245) and 18.9 %–31.5 % (SSP585) from the 2030 s to the 2090 s, respectively. Future projections also suggest a significant increase in the severity of mild, moderate, and severe droughts across the study area, with northwestern regions exhibiting the highest increase. The results of this study provide region specific valuable insights for efficient utilization of water resources, adaptive irrigation strategies, and need for drought-resistant crop varieties in the north of China.