China Grid-level Natural Streamflow Estimates (CHASE V1.0): Monthly and Yearly version

This record contains monthly and yearly averaged flow records of CHASE v1.0. For daily records, please visit https://doi.org/10.5281/zenodo.17386507 Overview CHinA grid-level natural Streamflow Estimates (CHASE v1.0) provides 1-km gridded estimates of natural streamflow across China, reconstructed using a coupled land-surface-hydrologic-hydrodynamic modeling system. It spans the period from January 1, 1962, to December 31, 2024, at a daily temporal resolution and 1-km spatial resolution. Validation against 1,225 flow gauges shows median daily Nash-Sutcliffe Efficiency (NSE) of 0.58, monthly NSE of 0.77, daily Kling-Gupta Efficiency (KGE) of 0.65, and monthly KGE of 0.73. Lake water level simulations are also satisfactory in major freshwater systems like Poyang, Dongting, Tai, Chao, and Hongze Lakes. Data Files The dataset consists of NetCDF files. Spatial Coverage: China, bounded approximately by latitudes 18°N to 53°N and longitudes 73°E to 135°E. Grid dimensions: 4087 rows (Y) × 4780 columns (X). Temporal Coverage: Monthly or yearly timesteps. Resolution: 1 km × 1 km (nominal grid cell size). Variables time (double, dimension: time): Time. XLONG (float, dimensions: Y, X): Longitude of each grid cell. XLAT (float, dimensions: Y, X): Latitude of each grid cell. streamflow (int, dimensions: time, Y, X): Natural streamflow rate. Units: m³/s; Scale factor: 0.1 (multiply stored values by 0.1 to get actual m³/s); Add offset: 0; Fill/missing value: -9999. Data are packed as integers for efficiency. Usage Notes Processing: Files can be read using standard NetCDF libraries. To unpack streamflow values: actual_value = (stored_value * scale_factor) + add_offset. Negative or fill values indicate no data (e.g., outside the model domain). Limitations: Data are model-derived and assume natural conditions; they do not include human interventions. Users should consult the associated papers for detailed validation metrics. Reference Ningpeng Dong, Mingxiang Yang, Jianhui Wei, et al. Reconstructing China's Natural Streamflow at 1 km resolution. Authorea. October 24, 2025. DOI: 10.22541/au.176132833.37694469/v1 For questions, contact: Ningpeng Dong (dongnp@iwhr.com).