Assessing spatiotemporal characteristics of drought and its effects on climate-induced yield of maize in Northeast China

Abstract

It is important to investigate the potential impacts of global climate change on crop yield especially there have been limited relevant studies conducted in the cold regions such as Northeast China. This study investigated the spatiotemporal characteristics of droughts on different growth stages of maize over Northeast China during 1960–2016 and the effects of droughts on the climate-induced yield of maize separated by the logistic regression model using standardized precipitation evapotranspiration index (SPEI), trend analysis methods, rotated empirical orthogonal function, wavelet method, and Hurst exponent. The results indicated that: 1) the spatiotemporal patterns of drought were identified at different growth stages and the changes in dryness/wetness condition presented significant periodic oscillation on different time scales. 2) The patterns of dryness/wetness conditions and the changing characteristics of each sub-region at the early growth (EG) and middle growth (MG) stages were similar. 3) The future drought trends in most stations would be consistent with the past trends. In addition to the wetting trend in the eastern and southern parts at the EG stage, the whole study area would show a drying trend in future at other growth stages. 4) The cross wavelet transform (XWT) was used to develop the changing relationships between climate-induced yield of maize and the dryness/wetness condition at different growth stages with obvious inter-annual periodicities. 5) For Northeast China, climatic factors that can affect the climate-induced yield of maize are firstly temperature, next precipitation, and thirdly dryness/wetness conditions.