Spatial-temporal changes in meteorological and agricultural droughts in Northeast China: change patterns, response relationships and causes

Under the background of climate warming, drought events occur frequently. Generally, meteorological drought leads to agricultural drought. Understanding the spatiotemporal distribution, characteristics of drought and the relationship between meteorological and agricultural drought are important for early drought warning. Northeast China (NEC) was selected as the study area. The spatiotemporal characteristics of meteorological drought and agricultural drought in different seasons in NEC were analyzed. Correlation analysis was employed to analyze the relationship between meteorological and agricultural drought in different vegetation types. Furthermore, cross-wavelet analysis was employed to further analyze the relationship between meteorological drought and agricultural drought, explore the teleconnection and large-scale climate patterns and investigate possible causes of drought variations in this region. The results showed that (1) the frequency of mild meteorological drought and low and that of moderate agricultural drought was high; (2) there was a significant positive correlation between meteorological drought and agricultural drought, while the change in agricultural drought lagged behind that of meteorological drought. (3) A strong correlation between meteorological drought and agricultural drought was identified in cropland areas. (4) The El Nino Southern Oscillation and Pacific interannual oscillation were important factors affecting the changes in meteorological drought and agricultural drought NEC. The results provide scientific ground for the sustainable development of agriculture, drought monitoring and early warning, disaster prevention and mitigation in NEC.