WAD2M: Global Wetland Area and Dynamics for Methane Modeling

WAD2M provides a 13.0 million km² global map of vegetated wetlands, excluding permanent water bodies and rice paddies, at a monthly timestep from 2000 to 2018. It combines microwave remote sensing of surface inundation with static datasets to distinguish wetland types, showing good agreement with independent inventories in the Amazon and West Siberian Lowlands. The dataset is designed specifically to reduce uncertainty in estimates of wetland methane emissions.

Use Cases

• Modeling spatiotemporal patterns of global methane emissions based on wetland inundation dynamics.
• Validating prognostic hydrological models (e.g., TOPMODEL) against satellite-derived inundation observations.
• Analyzing interannual and seasonal variation in wetland extent for climate impact studies.
• Discriminating between inland waters, agriculture, and vegetated wetlands in land cover classification.

Strengths

• Provides a long-term (2000-2018) monthly time series at a consistent ~25 km resolution.
• Explicitly excludes non-target features like permanent water and rice paddies to focus on vegetated wetlands.
• Validated against independent inventories with reported Cohen's kappa coefficients of 0.54 and 0.70 for major wetland complexes.

Limitations

• Spatial resolution is coarse (~25 km), limiting analysis of smaller wetland features.
• Key metadata such as specific column names, row counts, and exact file formats are not provided in the available sources.
• The dataset's temporal coverage ends in 2018, which may limit analysis of recent trends.

Provenance

Source

University of Maryland, College Park; Author Zhen Zhang.

Collection Method

Combines a time series of surface inundation from active and passive microwave remote sensing with six static discrimination datasets.

Time Range

2000-2018

Geography

Global