Diagnosis of the Evolutionary Characteristics and Variability of Meteorological Drought in the Yellow River Basin

Abstract

Frequent occurrences of meteorological droughts in the Yellow River Basin (YRB) result from the combined impact of global climate change and human activities. To address the problems of unclear evolution mechanism and difficulty in accurately determining the variability time of meteorological droughts in the basin, this study uses multi-scale Standardized Precipitation Evapotranspiration Index (SPEI) and integrates wavelet analysis with the Mann-Kendall to investigate the evolution patterns and variability characteristics of meteorological droughts in the basin. The findings indicate that: (1) Meteorological drought shows a trend of shifting from the upper to the middle and lower reaches of the river, with clear seasonal and interannual variability trends. (2) The basin experiences six primary drought periods, with durations ranging from 2 to 6 months and 10 to 18 months, the latter being particularly noteworthy. (3) The main periods of meteorological drought variability are concentrated from 03/2001 to 10/2014, from 06/2006 to 08/2006, from 10/2017 to 01/2019, and 11/2019. This study furnishes a scientific groundwork for enhancing water resource management in the YRB and elucidating the mechanisms underlying meteorological drought evolution. These insights contribute to fostering ecological preservation and facilitating high-quality development within the basin.