TITLE:
Recent Multidecadal Strengthening of the Wet Season Drought in Low-Latitude Highlands of China
AUTHORS:
Xinyue Cao, Lizi Wang, Yang Li
KEYWORDS:
Low-Latitude Highlands, Drought, Trend, Running Trend, Precipitation, Temperature
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.16 No.2,
April
17,
2026
ABSTRACT: The low-latitude highlands (LLH) of China are subject to highly variable and complex climatic conditions, shaped by the combined influences of monsoonal systems and mid- to high-latitude forcing. These climatic complexities pose persistent challenges to local agricultural sustainability and ecological security, underscoring the need for in-depth investigations into drought dynamics in this region. To address this gap, a sliding‑window trend analysis was employed to examine long‑term drought trends, using the Standardised Precipitation Evapotranspiration Index (SPEI) derived from temperature and precipitation datasets spanning 1901-2020. Results demonstrate a consistent escalation in drought severity across all four seasons in China’s LLH, with summer and autumn exhibiting more pronounced drying tendencies—autumn shows the strongest up-ward trend in drought intensity. Running trend analysis further confirms a marked intensification of drought conditions in the region since the 1990s. Spatially, drought has intensified in most parts of the LLH during summer and autumn, driven by the combined effects of reduced precipitation and simultaneous warming; conversely, the northeastern LLH has seen a mitigation in drying, mainly attributed to increased precipitation. A statistically significant warming trend in summer and autumn since the 1990s has also been observed in the LLH.