The intensifying spatial inhomogeneity of rainfall under greenhouse warming implies that more inhomogeneous hydrological extremes (IHEs), i.e., coexistence of extreme rainfall or drought, may be triggered. While vegetation growth in China is sensitive to hydrological hazards, the variability of IHEs and their ecological impacts remain underexplored. Here, we find a significant increase in IHEs during China's growing season since 2000 (+2.1 events or +14.52 days per decade), with a rapid sharp rise to an annual average of 6.4 events or 42.0 days in the past five years. The primary driver is the enhanced inhomogeneity of moisture-dynamic coupled weather conditions, overlapping with a northward shift of climatological precipitation distribution. This results in a"Wet-North and Dry-South"pattern of IHE impacts, which poses severe and asymmetric threats to vegetation growth in China, with the expansion of drought areas exerts stronger stress on vegetation than the compensatory effects of rainfall. Our findings suggest that the sharp rises of IHEs tend to yield net negative impacts on vegetation growth, highlighting the need for stronger hydrological management to reduce future risks.
Shengyuan Liu, Jeremy Cheuk-Hin Leung, Jianjun Xu et al.· 0 citations
Typhoon rainfall can trigger urban waterlogging within hours, but hydrodynamic modelling is impractical for rapid screening. For Typhoon Haikui (2311) across Guangdong, Guangxi, and Hainan, we integrated half-hourly Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG) Final Run V07 precipitation, LandScan population exposure (E), and an impervious-surface factor (I) derived from the China Land Cover Dataset into a Typhoon Rainfall Risk Index (TRRI). Rainfall hazard (H) combines event-total rainfall, rainfall duration, and maximum 3 h rainfall. Hazard clustered along the Guangdong coast, where maximum event-total and 24 h rainfall reached 529.7 and 272.8 mm, respectively. TRRI high-risk zones occupied 12.45% of the three-province land area. Defined by the largest weighted component, H-, E-, and I-dominated cells accounted for 60.5%, 33.4%, and 6.1% of the high-risk class. Of 22 reported waterlogging locations in the event-focused domain, 19 fell in high-risk zones; the 86.36% hit rate versus a 26.09% background area yielded an enrichment ratio of 3.31 (p < 0.001). In a descriptive full-domain check, all 49 distinct locations were medium or high. Relative to H alone, TRRI reclassified 20.59% of land upward and 20.64% downward, while 58.77% remained unchanged. TRRI supports rapid event-scale screening and risk prioritization for targeted disaster-prevention decision-making.
Yuheng Yan, Xiaolu Li, Wenjie He et al.· Water· 0 citations
