Propagation dynamics and causes of hydrological drought in response to meteorological drought at seasonal timescales

Abstract

According to the widely accepted definition of drought, meteorological and hydrological droughts originally develop from rainfall and runoff deficits, respectively. Runoff deficit is mainly derived from rainfall deficit, and the propagation from meteorological drought to hydrological drought is critical for agricultural water management. Nevertheless, the characteristics and dynamics of drought propagation in the spatiotemporal scale remain unresolved. To this end, the characteristics and dynamics of drought propagation in different seasons and their linkages with key forcing factors are evaluated. In this study, meteorological and hydrological droughts are characterized by the Standardized Precipitation Index (SPI) and the Standardized Runoff Index (SRI), respectively. Propagation time is identified by the corresponding timescale of the maximum correlation coefficient between the SPI and the SRI. Then, a 20-year sliding window is adopted to explore the propagation dynamic in various seasons. Furthermore, the multiple linear regression model is established to quantitatively explore the influence of meteorological factors, underlying surface features and teleconnection factors on the propagation time variations. The Wei River Basin, a typical Loess Plateau watershed in China, is selected as a case study. Results indicate the following: (1) the propagation time from meteorological to hydrological drought is shorter in summer (2 months) and autumn (3 months), whereas it is longer in spring (8 months) and winter (13 months). Moreover, the propagation rates exhibit a decreasing trend in warm seasons, which, however, show an increasing trend in cold seasons; (2) a significant slowing propagation in autumn is mainly caused by the decreasing soil moisture and precipitation, whereas the non-significant tendency in summer is generally induced by the offset between insignificant increasing precipitation and significant decreasing soil moisture; (3) the replenishment from streamflow to groundwater in advance prompts the faster propagation from meteorological to hydrological drought in spring and winter and (4) teleconnection factors have strong influences on the propagation in autumn, in which Arctic Oscillation, El Niño-Southern Oscillation and Pacific Decadal Oscillation mainly affect participation, arid index and soil moisture, thereby impacting drought propagation.

Hydrological drought forecasts using precipitation data depend on catchment properties and human activities

“…For instance, SPI-3 is better applied in south Europe to represent SSI-1. https://doi.org/10.1038/s43247-024-01295-w Meteorological drought propagation A time-lagged cross correlation approach was employed to investigate the drought propagation process (lag time) between meteorological and hydrological droughts (Method) 24 . The correlation analysis reveals both negative and positive lag times in the relationship between these two types of droughts (Fig.…”

“…The lag time was determined based on the correlation values of drought indices from 1991 to 2022. We applied the time-lagged cross correlation approach 24 . This method maintains the time series of dependent variable (i.e., SSI and SGI) and generates both lags and leads of the second variable (SPI) throughout the time period.…”

“…The LIS-FLOOD model simulates the full water cycle and is driven by observed and forecasted weather data to obtain the proxy observed data and forecasts, respectively 21,22 . To assess the relationship between meteorological and hydrological droughts, a Pearson's correlation analysis and a time-lagged cross correlation were conducted, respectively 23,24 . Lastly, we evaluated the performance of drought forecasts using the Brier Score (BS) 25 (Methods).…”

Biodiversity and Wetting of Climate Alleviate Vegetation Vulnerability Under Compound Drought‐Hot Extremes

“…Vegetation, as a key component of terrestrial ecosystems, serves as a crucial link between the soil and atmosphere, and its dynamics have a profound impact on carbon balance, water cycles, and climatic conditions (Linscheid et al., 2020; Piao et al., 2019; B. Zhang, Tian, et al, 2022). With global warming, intensities of climate extremes have increased over the past decades in many regions across the world, including droughts, heatwaves, severe storms, floods, and so on (Z. Huang et al., 2023; Ma & Yuan, 2024; Tian & Zhu, 2024; Tripathy & Mishra, 2023; H. Wang, Song, et al, 2023; Y. Wang & Yuan, 2023; G. Zhang et al, 2021; S. Zhang et al, 2023, 2024). Simultaneously or sequentially occurred drought and hot‐related extremes, commonly referred to as compound drought‐hot extremes (CDHEs), have already increased (Luca & Donat, 2023; Wu et al., 2021; G. Zhang et al., 2022).…”

Propagation Dynamics from Meteorological Drought to GRACE-Based Hydrological Drought and Its Influencing Factors

“…In the Wei River Basin, rising temperature and decreasing soil moisture and precipitation rather than irrigation water consumption dominate propagation dynamics from meteorological to agricultural drought [39]. Precipitation and soil moisture strongly influence propagation from meteorological to streamflow-driven hydrological drought in the Wei River Basin [40]. Overall, the main focus of previous studies has mainly been on direct climate factors including precipitation (PRE), evapotranspiration (ET), and temperature (TMP) on drought propagation [5,11,41,42].…”