The research paper, written by Professor Yang Haibo of the Zhengzhou University, is titled "Study of the temporal and spatial patterns of drought in the Yellow River basin based on SPEI," and was recently published in Science China: Earth Sciences.
The extreme-point symmetric mode decomposition (ESMD) and Bernaola-Galvan segmentation algorithm (BGSA) were used in this study.
The annual and seasonal variation, frequency and intensity of drought were studied in the YRB.
Influenced by geographical location and the East Asian monsoon climate, the hydrometeorological conditions of the YRB are complicated and varied.
With a deficiency of water resources and disequilibrium of the precipitation distribution, the YRB is the area most vulnerable to drought in the major basins of China.
The YRB spans a wide range of 23 longitudes and 10 latitudes.
Drought periods with 2.9, 5, 10.2 and 18.3 years were characterized by ESMD.
The BGSA can be used to divide the long research period with the obtained variability of each mean segment.
And the sequence of drought intensity was summer, spring, winter and autumn with mean values of 0.93, 0.40, 0.05 and 0.04, respectively.
The paper identified the spatial and temporal patterns of drought in the YRB for the last 55 years, and put forward the targeted drought resistance measures according to the characteristics of the YRB and the various subzones, which provided reference and basis for the monitoring and early warning of drought in other areas.