Long-term evolution and climatic associations of dry and warm snow droughts across the Tibetan plateau
5 affiliations
- 1China Institute of Water Resources and Hydropower Research, Beijing 100038, China; Institute of Pastoral Hydraulic Research，Ministry of Water Resources, Hohhot 010020, China; Yinshanbeilu Grassland Eco-Hydrology National Observation and Research Station, China Institute of Water Resources and Hydropower Research, Beijing 100038, China; Corresponding authors.
- 2China Institute of Water Resources and Hydropower Research, Beijing 100038, China; Corresponding authors.
- 3China Institute of Water Resources and Hydropower Research, Beijing 100038, China; Institute of Pastoral Hydraulic Research，Ministry of Water Resources, Hohhot 010020, China; Yinshanbeilu Grassland Eco-Hydrology National Observation and Research Station, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
- 4China Institute of Water Resources and Hydropower Research, Beijing 100038, China
- 5North China University of Water Resources and Electric Power, Zhengzhou 450046, China
Abstract
Seasonal snowpack on the Tibetan Plateau (TP) is an important store of water, yet long-term changes in snow drought types and their value for monitoring snow-water deficits remain unclear. Using multi-source data for 1982–2025, we classified dry (SWEI-3 ≤ −0.5; SPI-3 ≤ −0.5) and warm (SWEI-3 ≤ −0.5; SPI-3 > −0.5) snow droughts and assessed their trends, regional patterns, drought burden, and statistical climatic associations. Here, “warm” identifies an SWE deficit without a concurrent precipitation deficit, not a temperature-defined event. Total snow drought area increased by 0.595 percentage points yr −1 ( p < 0.001), mainly reflecting warm snow drought expansion (0.687 percentage points yr −1 ). Warm snow droughts accounted for 72.8% of snow drought occurrence, including 69%, 75%, and 72% in the western, south-central, and southeastern TP, respectively; the south-central TP showed the fastest historical increase. The positive warm-drought trend persisted when the product-transition years were excluded and under two alternative fixed seasonal windows, although trend magnitudes varied. Mean drought intensity changed little, and the increasing snow drought burden index largely reflected spatial expansion. XGBoost–SHAP identified precipitation as an important statistical discriminator (30.9% for dry and 23.1% for warm snow droughts), but the warm-drought model showed limited temporal discrimination (ROC-AUC = 0.548). No lagged climate-mode correlations survived false discovery rate correction, and composite NDVI differences were not significant. These results support monitoring seasonal SWE deficits without establishing specific physical mechanisms or downstream hydrological and ecological impacts.
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BibTeX
@article{zhao2026longterm,
title = {{Long-term evolution and climatic associations of dry and warm snow droughts across the Tibetan plateau}},
author = {Yiyang Zhao and Weijie Zhang and Miaomiao Ma and Yingjie Wu and Nan Qiao and Wenjun Wang and Zezhong Zhang and Haipeng Guo and Keke Zhao and Hengzhi Guo and Shuaijie Liang},
journal = {Ecological Indicators},
year = {2026},
month = oct,
doi = {10.1016/j.ecolind.2026.115750},
url = {https://doi.org/10.1016/j.ecolind.2026.115750},
note = {CC BY},
}
RIS
TY - JOUR
TI - Long-term evolution and climatic associations of dry and warm snow droughts across the Tibetan plateau
AU - Yiyang Zhao
AU - Weijie Zhang
AU - Miaomiao Ma
AU - Yingjie Wu
AU - Nan Qiao
AU - Wenjun Wang
AU - Zezhong Zhang
AU - Haipeng Guo
AU - Keke Zhao
AU - Hengzhi Guo
AU - Shuaijie Liang
PY - 2026
DA - 2026/10/30
JO - Ecological Indicators
DO - 10.1016/j.ecolind.2026.115750
UR - https://doi.org/10.1016/j.ecolind.2026.115750
AB - Seasonal snowpack on the Tibetan Plateau (TP) is an important store of water, yet long-term changes in snow drought types and their value for monitoring snow-water deficits remain unclear. Using multi-source data for 1982–2025, we classified dry (SWEI-3 ≤ −0.5; SPI-3 ≤ −0.5) and warm (SWEI-3 ≤ −0.5; SPI-3 > −0.5) snow droughts and assessed their trends, regional patterns, drought burden, and statistical climatic associations. Here, “warm” identifies an SWE deficit without a concurrent precipitation deficit, not a temperature-defined event. Total snow drought area increased by 0.595 percentage points yr −1 ( p < 0.001), mainly reflecting warm snow drought expansion (0.687 percentage points yr −1 ). Warm snow droughts accounted for 72.8% of snow drought occurrence, including 69%, 75%, and 72% in the western, south-central, and southeastern TP, respectively; the south-central TP showed the fastest historical increase. The positive warm-drought trend persisted when the product-transition years were excluded and under two alternative fixed seasonal windows, although trend magnitudes varied. Mean drought intensity changed little, and the increasing snow drought burden index largely reflected spatial expansion. XGBoost–SHAP identified precipitation as an important statistical discriminator (30.9% for dry and 23.1% for warm snow droughts), but the warm-drought model showed limited temporal discrimination (ROC-AUC = 0.548). No lagged climate-mode correlations survived false discovery rate correction, and composite NDVI differences were not significant. These results support monitoring seasonal SWE deficits without establishing specific physical mechanisms or downstream hydrological and ecological impacts.
SN - 1470-160X
SN - 1872-7034
ER -