Ma et al. (2026) The qualitative and quantitative relationship between the spatiotemporal variations of potential evapotranspiration and meteorological variables in the Hexi corridor, Northwest China

Identification

• Journal: Scientific Reports
• Year: 2026
• Date: 2026-03-05
• Authors: Yali Ma, Zuirong Niu, Xingfan Wang, Dongyuan Sun
• DOI: 10.1038/s41598-026-42072-3

Research Groups

College of Water Conservancy and Hydropower Engineering, Gansu Agricultural University, Lanzhou, China

Short Summary

This study investigated the spatiotemporal variations of potential evapotranspiration (ET0) and its response to meteorological factors in the Hexi Corridor, Northwest China, from 1960 to 2019, finding that ET0 showed a fluctuating increase primarily driven by increasing mean temperature.

Objective

• To reveal the spatiotemporal patterns of ET0 and six influencing meteorological factors (net solar radiation, wind speed at 2 m, mean air temperature, maximum air temperature, minimum air temperature, and relative humidity) in the Hexi Corridor between 1960 and 2019, using statistical analysis and spatial interpolation.
• To identify qualitative correlations between ET0 variation and climatic factors using principal component analysis, cluster analysis, and grey relational grade.
• To quantify the sensitivity of ET0 variations to meteorological variables through sensitivity analysis and to quantify the contribution of meteorological variables to ET0 variations through contribution rate calculations, thereby identifying the ET0 response mechanism to meteorology.

Study Configuration

• Spatial Scale: Hexi Corridor, Gansu Province, Northwest China (approximately 1,000 km long, area of 2.26 × 10^5 km^2).
• Temporal Scale: 60 years (1960–2019).

Methodology and Data

• Models used:
  • FAO Penman-Monteith (P-M) formula for ET0 calculation.
  • Linear regression for trend analysis.
  • Mann-Kendall non-parametric statistical test for trend and mutation analysis.
  • Moving T-Test (MTT) and cumulated anomalies curve for change point detection.
  • Principal Component Analysis (PCA) for dimensionality reduction and factor grouping.
  • Systematic cluster analysis (inter-group join, Pearson correlation) for variable similarity.
  • Grey relational grade for assessing the closeness of connections between ET0 and meteorological variables.
  • Sensitivity coefficient (Schaake's definition) and contribution rate calculation for quantitative attribution.
• Data sources:
  • Daily meteorological data (1960.1.1 to 2019.12.31) from 21 meteorological stations in the Hexi Corridor, obtained from the China Meteorological Data Network (http://data.cma.cn).
  • Missing daily data (less than 1%) were interpolated based on regression relationships from nearby stations.

Main Results

• ET0 in the Hexi Corridor showed a fluctuating increase from 1960 to 2019, with an annual average of 1186.93 mm. Change points were identified in 1969 and 2002.
• Spatially, ET0 increased from southeast to northwest, ranging from 812.3 mm to 1516.6 mm. Most areas showed an increasing trend (up to 2.5 mm/yr), while some western stations experienced decreases (up to -3.0 mm/yr).
• Seasonal ET0 was highest in summer (317.5 to 687.8 mm) and lowest in winter (59.6 to 99.9 mm).
• From 1960 to 2019, precipitation, mean air temperature, maximum air temperature, and minimum air temperature showed significant upward trends. Net solar radiation, wind speed at 2 m, and relative humidity showed downward trends, with wind speed decreasing significantly.
• Principal Component Analysis and cluster analysis grouped meteorological factors into two main types: temperature factors (mean, max, min temperatures, and net solar radiation) and humidity/wind speed factors. Temperature factors accounted for 67.95% of the cumulative variance.
• The sensitivity of ET0 to meteorological variables was ranked as: net solar radiation > wind speed at 2 m > mean air temperature > relative humidity > maximum air temperature > minimum air temperature. ET0 was most sensitive to a decrease in net solar radiation, followed by a decrease in wind speed.
• Increasing mean air temperature was the dominant factor for the increase in ET0 in the Hexi Corridor during 1969–2019, contributing 90.66%. Net solar radiation and wind speed at 2 m had smaller, often counteracting, contributions (-18.08% and -1.32%, respectively). The combined contribution of the six meteorological factors was 72.39%.

Contributions

• This study provides a comprehensive and objective analysis of ET0 variations and its response to climate factors by organically combining both qualitative (PCA, cluster analysis, grey relational grade) and quantitative (sensitivity analysis, contribution rate calculation) methods, addressing a gap in previous research that often focused on single aspects.
• It offers a scientific reference for more rational planning and efficient utilization of agricultural water resources in arid and semi-arid regions like the Hexi Corridor, particularly under the context of climate change.

Funding

• National Natural Science Foundation of China (NSFC) (42261003)
• Key R&D Plan of Gansu Province (21YF5FA094; 22YF7GA107)

Citation

@article{Ma2026qualitative,
  author = {Ma, Yali and Niu, Zuirong and Wang, Xingfan and Sun, Dongyuan},
  title = {The qualitative and quantitative relationship between the spatiotemporal variations of potential evapotranspiration and meteorological variables in the Hexi corridor, Northwest China},
  journal = {Scientific Reports},
  year = {2026},
  doi = {10.1038/s41598-026-42072-3},
  url = {https://doi.org/10.1038/s41598-026-42072-3}
}