Investigating the Propagation From Meteorological to Hydrological Drought by Introducing the Nonlinear Dependence With Directed Information Transfer Index

Abstract

Meteorological drought is the fuse of hydrological drought, and understanding the propagation mechanisms from meteorological to hydrological drought is of great significance to the monitoring and prevention of hydrological drought. Besides the linear dependence, this study thoroughly investigated the propagation from meteorological to hydrological drought by introducing the nonlinear dependence with directed information transfer index (DITI) for the first time. In this study, the standardized precipitation index and the standardized runoff index were used to represent meteorological drought and hydrological drought, respectively. A new drought response time (DRT) evaluation system was constructed based on the maximum Pearson correlation coefficient and DITI, simultaneously considering the linear and nonlinear relationships between meteorological drought and hydrological drought. Moreover, the relationships of drought characteristics (duration and severity) between these two types of drought were established by using run theory and mathematical function, and the trigger thresholds from meteorological to hydrological drought were then determined. The results indicate that: (a) the effective drought propagation rate was mainly affected by the characteristics of meteorological drought events and the sensitivity of hydrological drought to meteorological drought; (b) the DRT in the Pearl River Basin (PRB) was mainly concentrated in 2–5 months, and the drought translation rate in the PRB was relatively large; and (c) the duration of hydrological drought events was longer in the sub‐regions with smaller meteorological drought trigger thresholds.

The dynamic change of propagation from meteorological drought to hydrological drought at the basin scale: A case study from the Weihe River Basin, China

“…Ho et al (2021) established a new framework for calculating the transmission time, measuring temporal changes (transmission time) in the areas affected by drought. Zhou et al (2021) introduced a nonlinear correlation with the Directional Information Transfer Index (DITI) to build a new drought response time (DRT) evaluation system and then determined the trigger threshold from meteorological drought to hydrological drought. Ding et al (2021) used SPE, SRI, and scPDSI to represent meteorological drought, agricultural drought, and hydrological drought, respectively, to explore the interaction of multiple droughts between different climatic zones and seasons in China.…”

Comprehensive evaluation of vegetation responses to meteorological drought from both linear and nonlinear perspectives

“…Mutual information is an important method in information theory and is commonly used to test the nonlinear relationship between two sequences (Shi B. et al, 2018;Fang et al, 2020). The DITI is used to represent the directional information transfer quantity of a specific information source by information entropy based on mutual information and is used to characterize the relationship between the information source and information function points (Zhou et al, 2021b). In this study, meteorological drought and vegetation change were taken as the information source and the information function point, respectively.…”

The Peer‐To‐Peer Type Propagation From Meteorological Drought to Soil Moisture Drought Occurs in Areas With Strong Land‐Atmosphere Interaction

“…The spatial resolution of 0.1 × 0.1°, and the available period is 1981-2020. This data set is a series of improvements to the ERA-5 data set, which enables ERA-5 data sets to be more accurately applied to all types of land applications (Pelosi et al, 2020;Zhou et al, 2021bZhou et al, , 2021c. Among many data products, ERA5-Land has comprehensive application potential in China (Li, Ye, et al, 2021).…”