Global Composite Wetland Maps Combining Surface Water and Groundwater Data

Multi-source global wetland maps combine regularly flooded wetlands from satellite imagery with groundwater-driven wetlands from hydrological modelling. Seven composite maps were generated at approximately 500-meter resolution, estimating global wetland extents of 27.5 and 29 million km². The dataset was developed by Ardalan Tootchi of the Centre National de la Recherche Scientifique.

Use Cases

• Large-scale hydrological modelling based on wetland extent and type data.
• Ecological modelling based on the distinction between regularly flooded and groundwater-driven wetlands.
• Environmental planning based on global maps of potential wetland areas.
• Validating other wetland datasets based on the composite mapping approach.

Strengths

• Provides seven distinct composite maps at approximately 500-meter (15 arc-second) resolution.
• Reports a global wetland extent of 27.5 and 29 million km², covering 21.1% and 21.6% of global land area.
• Distinguishes between regularly flooded wetlands (9.7% of land) and groundwater-driven wetlands (15% of land).
• Validated against regional datasets, performing well over France compared to other global datasets.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Column-level documentation is absent; field semantics must be inferred after download.
• Last update date is unknown; freshness unverified.

Provenance

Source

Ardalan Tootchi, Centre National de la Recherche Scientifique.

Collection Method

Data fusion using GIS tools to combine satellite-derived inundation datasets with groundwater modelling outputs.

Time Range

Contemporary potential wetlands under present climate.

Geography

Global.