Assessing the Drought Variability in Northeast China over Multiple Temporal and Spatial Scales

Abstract

Long-term drought variation provides a scientific foundation for water resource planning and drought mitigation. However, the spatiotemporal variation characteristics of drought in northeast China (NEC) are unclear. We conducted a comprehensive assessment of drought status and trends based on the Standardized Precipitation Evapotranspiration Index (SPEI) in NEC from 1990 until 2018. The findings show that: (1) the drying trend peaked in 2001, and then exhibited a mitigation tendency before drying again after 2013. The implementation of ecological restoration projects is primarily responsible for drought mitigation. (2) The areas with wetting and drying trends in the future would cover 86% and 17% of NEC, respectively. (3) There is a time lag between improved vegetation and the trend shift from dry to wet. (4) Spring and winter revealed wet trends within 71% and 84% of NEC, respectively, showing high sensitivity and resilience to drought, while 92–93% of NEC displayed dry tendencies during the summer and autumn seasons. The drought-affected area was the highest in summer and lowest in autumn. (5) The interannual drought severity was highest in May and June. (6) The highest drought impacts and trends occur within shrub and grass and sparsely vegetated land, as well as middle-temperate semiarid regions (M-semiarid). (7) The warmer the temperature zone, the more sensitive it is towards drought under the same hydrological conditions, showing a high drought-affected area. The drier the land, the higher the drought-affected area within the same temperature zone, with pronounced drought trends during the spring and summer seasons. Our findings highlight the need for the government to more explicitly develop drought mitigation strategies in accordance with NEC’s spatiotemporal drought variations and specifically the need to concentrate on droughts in M-semiarid regions occurring in summer, particularly in May and June.

Characteristics of the Spatial and Temporal Distribution of Drought in Northeast China, 1961–2020

“…The SPEI has a flexible time scale and fully considers the influence generated by temperature, and the drought events obtained from the treatment tend to be consistent with previous research results [41,48]. Temporal changes in annual-scale drought in Northeast China had prominent interannual characteristics, with the most significant positive and…”

Analysis of the Variability Characteristics and Applicability of SPEI in Mainland China from 1985 to 2018

“…Figure 5a shows that the regions with the highest frequency of drought occurrence were mostly concentrated in west-central Jilin and southern Liaoning. SPEI monitored droughts of long duration and high severity mainly in northwestern Liaoning, southwestern Heilongjiang, and west-central Jilin, which was generally consistent with records, and the identification results were in general agreement with the findings of Xue et al [38].…”

Climate Change and Health: Insight into a Healthy, Sustainable and Resilient Future

“…Xue et al [25], conducted a comprehensive assessment of drought status and trends based on the Standardized Precipitation Evapotranspiration Index (SPEI) in Northeast China (NEC) from the period of 1990 until 2018. The authors found that NEC has exhibited a general dry tendency over the past three decades.…”