Investigating the meteorological causes of hydrological drought through the integration of spatiotemporal cubes and interpretable machine learning: A case study of the Yangtze River Basin

Study region

Yangtze River,China

Study focus

Climate warming and extreme weather events have intensified hydrological drought, especially at long-term and large scales, making the impact of meteorological factors particularly important. This study evaluates the impact of meteorological factors (temperature, precipitation, potential evapotranspiration) on hydrological drought in the Yangtze River basin from 1980 to 2019. The study employs a spatiotemporal cube to analyze the clustering and hotspots of meteorological factors. This study developed optimal interpretable models using XGBoost-SHAP and CNN-SHAP, quantifying the impacts of climate change and human activities on hydrological drought, and analyzing the underlying causes of hydrological drought.

New hydrological insights for the region

The climate characteristics of the Yangtze River basin show significant differences, and various meteorological factors have a notable impact on hydrological drought. Hydrological drought in the upper reaches of the Yangtze River basin is primarily driven by climate change, contributing 85 %, whereas the impact in the downstream has decreased, with a contribution rate of 55 %. The contribution of meteorological factors to hydrological drought varies between the upper and lower reaches of the Yangtze River, with the upper reaches primarily influenced by relative humidity (SHAP value 0.27) and the lower reaches primarily influenced by average temperature (SHAP value 0.25). This study explores the impact of meteorological factors on hydrological drought and provides a theoretical foundation for the prevention and control of hydrological drought in the basin.