Tian et al. (2025) A dataset of 500 m annual MPDI data for the Weihe River Basin from 2000 to 2024

Identification

• Journal: China Scientific Data
• Year: 2025
• Date: 2025-12-01
• Authors: Congshan Tian, Yumin Kang, Kai Feng
• DOI: 10.11922/11-6035.csd.2025.0110.zh

Research Groups

• State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences
• Loess Science Data Center, Institute of Earth Environment, Chinese Academy of Sciences
• College of Geography and Environment Sciences, Northwest Normal University

Short Summary

This study developed a 25-year (2000–2024) annual Modified Perpendicular Drought Index (MPDI) dataset for the Weihe River Basin at 500 m spatial resolution using the Google Earth Engine (GEE) platform, providing a robust tool for dynamic drought monitoring and water resource management.

Objective

• To construct a long-term (2000–2024) Modified Perpendicular Drought Index (MPDI) dataset for the Weihe River Basin to address the practical needs of drought monitoring, thereby providing a reliable basis for assessing drought frequency, intensity, and spatial expansion trends.

Study Configuration

• Spatial Scale: Weihe River Basin (33°41′46″–37°24′30″N, 103°58′18″–110°16′28″E), with a spatial resolution of 500 meters.
• Temporal Scale: Annual data from 2000 to 2024, specifically covering the growing season (day 80–290, approximately March 20 to October 16) for each year.

Methodology and Data

• Models used:
  • Modified Perpendicular Drought Index (MPDI) model, which incorporates fractional vegetation cover (fv) into the traditional Perpendicular Drought Index (PDI) model.
  • Semi-empirical model for fractional vegetation cover (fv) estimation based on Normalized Difference Vegetation Index (NDVI).
  • Linear regression for soil line equation fitting (R² ≥ 0.85).
• Data sources:
  • MODIS MOD09A1 V61 8-day composite surface reflectance product (500 m spatial resolution) for the period 2000–2024.
  • Google Earth Engine (GEE) platform for data processing and analysis.
  • Weihe River Basin vector boundary data from the National Glacier, Permafrost and Desert Science Data Center.
  • Measured soil moisture (0–10 cm depth) from 53 monitoring stations in the Weihe River Basin (China Meteorological Administration National Meteorological Information Center) for validation.

Main Results

• A comprehensive annual MPDI dataset for the Weihe River Basin from 2000 to 2024, with a 500 m spatial resolution, was successfully generated and validated.
• Drought conditions in the Weihe River Basin exhibited phased fluctuations over the 25-year period, with a trend of alleviation observed in the central-eastern and southern regions since 2015.
• The MPDI product revealed significant spatial differentiation, with higher drought index values in the northern and central Loess Plateau (characterized by agricultural areas and bare land) and lower values in the southern Qinling Mountains (dominated by forests and grasslands).
• The MPDI showed a significant negative correlation with measured 0–10 cm soil moisture (Pearson correlation coefficient = -0.26, P < 0.001), confirming its sensitivity and applicability for shallow soil drought monitoring.
• The MPDI demonstrated adaptability across different land cover types, with its response primarily driven by soil moisture in low vegetation areas (fv < 0.3) and significantly influenced by vegetation biophysical parameters in high vegetation areas (fv > 0.5).

Contributions

• Provides the first long-term (2000–2024) annual Modified Perpendicular Drought Index (MPDI) dataset for the Weihe River Basin at a 500 m spatial resolution, filling a critical data gap for regional drought monitoring.
• Enhances the accuracy of drought monitoring in vegetated areas by integrating fractional vegetation cover into the traditional PDI model, effectively mitigating vegetation interference.
• Offers a reliable and high-resolution data foundation for assessing the frequency, intensity, and spatial expansion trends of drought events, supporting refined water resource management and disaster risk assessment.
• Demonstrates the efficiency and capability of the Google Earth Engine (GEE) platform for large-scale, long-term remote sensing data processing and drought index generation.

Funding

• Independent Deployment Project of the State Key Laboratory of Loess Science (E452840100)

Citation

@article{Tian2025dataset,
  author = {Tian, Congshan and Kang, Yumin and Feng, Kai},
  title = {A dataset of 500 m annual MPDI data for the Weihe River Basin from 2000 to 2024},
  journal = {China Scientific Data},
  year = {2025},
  doi = {10.11922/11-6035.csd.2025.0110.zh},
  url = {https://doi.org/10.11922/11-6035.csd.2025.0110.zh}
}