GCN250, new global gridded curve numbers for hydrologic modeling and design

Abstract

The USDA curve-number (CN) method is fundamental for rainfall-runoff modeling. A global CN database is not currently available for geospatial hydrologic analysis at a resolution higher than 0.1°. We developed a globally consistent, gridded dataset defining CNs at the 250 m spatial resolution from new global land cover (300 m) and soils data (250 m). The resulting data product – GCN250 – represents runoff for a combination of the European space agency global land cover dataset for 2015 (ESA CCI-LC) resampled to 250 m and geo-registered with the hydrologic soil group global data product (HYSOGs250m) released in 2018. Our analysis indicated that medium to high runoff potential currently dominates the globe, with curve numbers ranging between 75 and 85. Global curve numbers were 62, 78, and 90 for dry, average, and wet antecedent runoff conditions, respectively. Australia has the highest runoff potential, while Europe has the lowest. Runoff ratios compare well with GLDAS. The potential application of this data includes hydrologic design, land management applications, flood risk assessment, and groundwater recharge modeling.

Abstract

Design Type(s)	modeling and simulation objective • data integration objective
Measurement Type(s)	hydrological process
Technology Type(s)	computational modeling technique
Factor Type(s)	geographic location • hydrological process • soil • land use
Sample Characteristic(s)	Earth (Planet) • soil • land • ecosystem • hydrological process

Machine-accessible metadata file describing the reported data (ISA-Tab format)