Work

Revealing multiple drought propagation characteristics on the basis of GNSS hydrometeorological data and precipitation

Year: 2026

Type: article

Abstract: Study region Yunnan Province. Study focus This study extends GNSS-based drought propagation analysis beyond time-lag estimation by introducing a risk-oriented framework. High-spatial-resolution ZTD-PE and GNSS-TWSC are first used to construct meteorological and hydrological drought indices, respectively. Subsequently, run theory, copula functions, and Bayesian conditional probability are integrated to quantify propagation time, triggering probability, and meteorological drought thresholds from 2012 to 2022, with GRACE and GLDAS used as complementary references to examine the added value of GNSS-derived water storage information. New hydrological insights Drought propagation across Yunnan is generally rapid, typically occurring within 1–6 months. Influenced by regional runoff patterns and human activities, propagation time exhibits a clear spatial pattern, with longer durations in the south and shorter durations in the north. Under meteorological drought stress, the probability of hydrological drought being triggered is significantly higher in southwestern Yunnan than in northeastern Yunnan. This pattern is closely associated with anthropogenic influences in eastern Yunnan and precipitation variability related to the southwestern monsoon. Integrated analysis using GNSS, GRACE, and GLDAS further indicates that terrestrial water storage changes in Yunnan are particularly sensitive to severe and extreme meteorological drought, especially in the southwest, whereas near-surface water responds more strongly to moderate meteorological drought, with potential implications for vegetation growth and agricultural management.

Source: Journal of Hydrology Regional Studies

DOI: 10.1016/j.ejrh.2026.103829