Liu et al. (2025) Study on the characteristics and formation mechanism of extreme heat and drought in central Hexi Corridor, China

Identification

• Journal: Theoretical and Applied Climatology
• Year: 2025
• Date: 2025-10-01
• Authors: Honglan Liu, Tingjia Zhang, Qiang Zhang, Junguo Zhang, Chao‐Hsien Chu, Xueyu Liu, Hua Guo, Shuzhen Wang, Haibo Wang
• DOI: 10.1007/s00704-025-05586-w

Research Groups

• Zhangye Meteorological Bureau, Zhangye, China
• Shanghai Aerospace Equipments Manufacturer Co.Ltd., Shanghai, China
• Institute of Arid Meteorology, China Meteorological Administration, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Key Open Laboratory of Arid Climatic Change and Disaster Reduction of CMA, Lanzhou, China
• Zhangye Middle School, Zhangye, China
• Huanxian Meteorological Bureau, Huanxian, China

Short Summary

This study analyzed the characteristics and formation mechanisms of the extreme heat and drought in the central Hexi Corridor from May to September 2023, revealing record-high temperatures and record-low precipitation driven by specific atmospheric circulation and sea surface temperature anomalies.

Objective

• To characterize the spatiotemporal features and impacts of the extreme heat and drought in the central Hexi Corridor from May to September 2023.
• To investigate the formation mechanisms of this extreme drought, specifically its anomalous response to atmospheric circulation and sea surface temperatures in key regions.

Study Configuration

• Spatial Scale: Central Hexi Corridor, China (approximately 37°28'N to 39°57'N, 97°20'E to 102°12'E), including the Qilian Mountains and the Heihe River basin.
• Temporal Scale: Data spanning 1967–2023, with a specific focus on the extreme event from May to September 2023.

Methodology and Data

• Models used: Meteorological statistical analysis, Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Temperature Vegetation Drought Index (TVDI), wavelet transform, wavelet variance, and correlation analysis.
• Data sources:
  • Monthly precipitation and temperature records (1967–2023) from six national meteorological stations in the central Hexi Corridor (Zhangye, Gaotai, Linze, Shandan, Minle, Sunan) from the Gansu Meteorological Bureau's Information Center.
  • Heihe River runoff data (1967–2023) from the Yingluoxia Hydrological Station.
  • Satellite images: FY-3D/MERSI (1 km by 1 km clear-sky remote sensing data for TVDI and snow cover) and GF-1 (16 m by 16 m clear-sky data for reservoir water body area).
  • National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) monthly reanalysis data (2.5° by 2.5° horizontal resolution).
  • National Climate Center (NCC) atmospheric circulation indices (88 monthly indices, 2.5° by 2.5° resolution) and Sea Surface Temperature (SST) indices (26 monthly indices, 2.0° by 2.0° resolution).

Main Results

• From May to September 2023, the central Hexi Corridor experienced an unprecedented heatwave and drought, with the average temperature reaching a record high (1.9 °C above historical averages) and precipitation hitting a record low (43% below historical averages).
• The Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) values for this period were -1.92 and -2.53, respectively, indicating severe to extreme drought conditions, the most severe on record.
• The meteorological drought led to a significant hydrological drought, characterized by a 45.8% reduction in average snow cover area in the central Qilian Mountains (June–August 2023) and a 15% decrease in annual Heihe River runoff (25% decrease in summer runoff) compared to long-term averages. Reservoir areas decreased by 25.8% to 66.0% compared to historical averages.
• Ecological and agricultural impacts included reduced vegetation growth and severe crop damage across 154,448.8 hectares, resulting in direct economic losses of RMB 218,622,200.
• The extreme drought was associated with distinct 500 hPa atmospheric circulation anomalies, including a "+—+" pattern across East Asia, high-pressure blocking near Lake Baikal or the Sea of Okhotsk, an Okhotsk High as a primary driver, a small polar vortex area, an eastward-extended South Asian High, and a southward-positioned, weaker West Pacific subtropical high with an eastward ridge.
• Sea surface temperature (SST) anomalies featured warmer-than-normal conditions in the Niño 3 and West Wind Drift regions, and cooler-than-normal conditions in the Kuroshio region.
• Multi-scale analysis of precipitation revealed significant quasi-periodic variations at 5, 11, 17, and 32 years, with 2023 falling within a below-normal period for these cycles, suggesting a combined influence of multiple timescales on the drought's severity.

Contributions

• Provides a comprehensive, multi-faceted analysis of the characteristics and impacts (meteorological, hydrological, ecological, agricultural) of the unprecedented extreme heat and drought event in the central Hexi Corridor in 2023.
• Identifies specific atmospheric circulation patterns (e.g., "+—+" pattern at 500 hPa, Okhotsk High, polar vortex anomalies, South Asian High position, West Pacific subtropical high characteristics) and key SST anomalies (Niño 3, West Wind Drift, Kuroshio) as primary drivers of the 2023 extreme drought.
• Utilizes multi-scale wavelet analysis to demonstrate the contribution of multiple natural oscillation cycles (5, 11, 17, 32 years) to the severity of the 2023 drought.
• Offers crucial insights for improving drought monitoring, mitigation strategies, and forecasting capabilities in the vulnerable arid and semi-arid regions of Northwest China.

Funding

• National Natural Science Foundation of China (U24A20604, 42230611)
• Natural Science Foundation of Gansu Province of China (24JRRA742)
• Natural Science Foundation of Ningxia Province of China (2023AAC02088)
• Key R&D and Achievements Transformation Project Attached to Tibet Autonomous Region Science and Technology Plan (XZ202401ZY0065)
• Scientific Research Project supported by Gansu Meteorological Bureau (Ms2024-D-8)

Citation

@article{Liu2025Study,
  author = {Liu, Honglan and Zhang, Tingjia and Zhang, Qiang and Zhang, Junguo and Chu, Chao‐Hsien and Liu, Xueyu and Guo, Hua and Wang, Shuzhen and Wang, Haibo},
  title = {Study on the characteristics and formation mechanism of extreme heat and drought in central Hexi Corridor, China},
  journal = {Theoretical and Applied Climatology},
  year = {2025},
  doi = {10.1007/s00704-025-05586-w},
  url = {https://doi.org/10.1007/s00704-025-05586-w}
}