Metadata and source data for research entitled "Global hydrological drought diverges from atmospheric drying"

Overview This dataset provides the source data underlying main-text Figures 1–4 of “Global hydrological drought diverges from atmospheric drying” by Yuhan Guo, Yuting Yang, Jinghua Xiong, Shanbai Liang, Li Guo and Dawen Yang. It also includes the catchment metadata and environmental attributes used in the historical analysis. The dataset supports a global comparison of atmospheric drought, represented by the six-month Standardized Precipitation Evapotranspiration Index (SPEI), and hydrological drought, represented by the six-month Standardized Streamflow Index (SSI). Historical analyses cover 1981–2019 and include 18,907 catchments. Future analyses cover 2020–2100 under SSP3-7.0 on a masked 0.5° global land grid. Dataset contents File Description Metadata_catchment_attributes_final.xlsx Catchment identifiers, coordinates, areas, model-performance metrics, leaf area index and selected BasinATLAS attributes, with a field-level variable dictionary and completeness summary. Data_S1_Fig1.xlsx Historical catchment-scale SPEI and SSI trends and global monthly time series for 1981–2019. Data_S1_Fig2.xlsx Historical trends and annual time series of drought frequency and magnitude for SPEI and SSI. Data_S1_Fig3.xlsx Bounded Hydrological Response Index (BHRI), direction-aligned hydrological response (H*), drying–wetting asymmetry, nonlinear fits and heterogeneity statistics. Data_S1_Fig4.xlsx Future SPEI and SSI index, frequency and magnitude trends and ensemble time series for 2020–2100 under SSP3-7.0. README.txt Detailed definitions, worksheet descriptions, units, missing-data information and sign conventions. Methods represented in the data SPEI: six-month accumulation, generalized logistic distribution fitted using L-moments. SSI: six-month accumulation, generalized extreme value distribution fitted using L-moments. Atmospheric drought ensemble: CHIRPS–GLEAM, CHIRPS–HPET, MSWEP–GLEAM and MSWEP–HPET. Drought month: standardized index below −1. Annual drought frequency: number of drought months per year. Annual drought magnitude: absolute cumulative drought deficit, calculated as the negative sum of index values below −1 within each year. Larger positive values indicate more severe cumulative drought. Historical spatial unit: retained river catchment. Future spatial unit: masked 0.5° land grid cell. Key features Globally distributed historical sample of 18,907 catchments. Four observational precipitation–potential-evaporation combinations for quantifying SPEI product uncertainty. Catchment-scale atmospheric and hydrological drought trends, with associated significance information. Panel-ready source tables for all main-text figures. Hydrological propagation metrics including BHRI, H*, response asymmetry and heterogeneity. SSP3-7.0 projections based on five CMIP6 GCMs and four hydrological/ET index variants. Field-level catchment metadata dictionary and completeness information. Coverage and known limitations CHIRPS is limited to 60°S–60°N. Consequently, CHIRPS-based historical SPEI results are unavailable for 904 catchments outside this latitude range; a further 89 catchments have incomplete CHIRPS precipitation records. Future SPEI and SSI are standardized independently over 2020–2100 and represent anomalies relative to the future-period climatology rather than the historical 1981–2019 climatology. Figure 4 excludes hyper-arid grid cells (aridity index ≤ 0.1) and cold grid cells (mean annual temperature ≤ −10 °C). Empty spreadsheet cells represent unavailable or non-computable values and must not be interpreted as zeros. Recommended citation Please cite both this Zenodo record and the associated article: Guo, Y., Yang, Y., Xiong, J., Liang, S., Guo, L. & Yang, D. Global hydrological drought diverges from atmospheric drying. When describing a specific analysis, also report the workbook, worksheet, product combination, time period and magnitude sign convention used. Keywords Hydrological drought; atmospheric drought; SPEI; SSI; streamflow; drought propagation; catchments; climate change; CMIP6; GLEAM; CHIRPS; MSWEP; global hydrology