Mapping Global Non-Floodplain Wetlands
Abstract. Non-floodplain wetlands – those located outside the floodplains – have emerged as integral components to watershed resilience, contributing hydrologic and biogeochemical functions affecting watershed-scale flooding extent, drought magnitude, and water-quality maintenance. However, the absence of a global dataset of non-floodplain wetlands limits their necessary incorporation into water quality and quantity management decisions and affects wetland-focused wildlife habitat conservation outcomes. We addressed this critical need by developing a publicly available Global NFW (non-floodplain wetland) dataset, comprised of a global river-floodplain map at 90 m resolution coupled with a global ensemble wetland map incorporating multiple wetland-focused data layers. The floodplain, wetland, and non-floodplain wetland spatial data developed here were successfully validated within 21 large and heterogenous basins across the conterminous United States. We identified nearly 33 million potential non-floodplain wetlands with an estimated global extent of over 16 million km2. Non-floodplain wetland pixels comprised 53 % of globally identified wetland pixels, meaning the majority of the globe’s wetlands likely occur external to river floodplains and coastal habitats. The identified Global NFWs were typically small (median 0.039 km2), with a global median size ranging from 0.018–0.138 km2. This novel geospatial Global NFW dataset advances wetland conservation and resource-management goals while providing a foundation for global non-floodplain wetland functional assessments, facilitating non-floodplain wetland inclusion in hydrological, biogeochemical, and biological model development. The data are freely available through the United States Environmental Protection Agency’s Environmental Dataset Gateway (https://gaftp.epa.gov/EPADataCommons/ORD/Global_NonFloodplain_Wetlands/) and through https://doi.org/10.23719/1528331 (Lane et al., 2023).
Charles R. Lane et al.
Status: open (until 05 Apr 2023)
- RC1: 'Comment on essd-2023-3', Youjiang Shen, 09 Mar 2023 reply
- RC2: 'Comment on essd-2023-3', Michele Ronco, 15 Mar 2023 reply
Charles R. Lane et al.
Global floodplains data set (GFPlain90) https://doi.org/10.23719/1528331
Global wetland data set (Global Wetlands) https://doi.org/10.23719/1528331
Global non-floodplain wetlands data set (Global NFWs) https://doi.org/10.23719/1528331
Charles R. Lane et al.
Viewed (geographical distribution)
Lane et al. (2023) presents the initial global geospatial dataset of non-floodplain wetlands by integrating the global floodplain and wetland datasets. The floodplain dataset is produced utilizing an existing algorithm and the MERIT Hydro dataset, whereas the wetland dataset is resampled and modified with greater precision, incorporating previous 500 m CW-WTD data and the GSW and CCI datasets. The authors evaluate the datasets in 21 CONUS watersheds, examining their locations and extents. The study provides valuable insights for hydrological and biogeochemical scientists investigating the impacts and functions of (eco)hydrological cycles. Nonetheless, some aspects require further explanations/modifications in the main text. So, I recommend major revision. Please find my comments in the following.
The subscripts in Table 1 require further clarification as they are not clearly understandable.
In Section 2.4.2, it would be preferable to have a table containing all these equations for the sake of conciseness.
Line 358: Is it necessary to include citations for all 7 references to define the Hit Rate? It would be more appropriate to include the most relevant reference for the definition in the article and please balance the number of citations throughout the paper.
Line 189: Please clarify the upscaling parameters.
Line 581, not clear “global population of wetlands"
Line 663: Please exclude this reference that is still under review.
Instead of presenting the results in similar tables (tables 2-5), it would be more engaging to include some figures that can get the reader's attention.
The statement in lines 261-263 about not losing any data when resampling to a finer resolution needs further clarification.
The methodology section in 2.2 about the global wetland data could benefit from further clarification. To improve the clarity, it is recommended to introduce the CW-WTD dataset first, followed by the description of the other datasets (RFWs and GDWs). This may help the reader better understand the analysis approach and the role of each dataset in the study.