Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences
RESEARCH ARTICLE

Global extent and distribution of wetlands: trends and issues

N. C. Davidson A B D , E. Fluet-Chouinard C and C. M. Finlayson A
+ Author Affiliations
- Author Affiliations

A Institute for Land, Water and Society, Charles Sturt University, Elizabeth Mitchell Drive, PO Box 789, Albury, NSW 2640, Australia.

B Nick Davidson Environmental, Queens House, Ford Street, Wigmore, HR6 9UN, UK.

C Hasler Laboratory of Limnology, University of Wisconsin—Madison, 680 N. Park Street, Madison, WI 53706, USA

D Corresponding author. Email: arenaria.interpres@gmail.com

Marine and Freshwater Research 69(4) 620-627 https://doi.org/10.1071/MF17019
Submitted: 26 January 2017  Accepted: 16 September 2017   Published: 10 January 2018

Abstract

Herein we review estimates of global and regional wetland area from ‘bottom-up’ approaches of site or national wetland inventories and ‘top-down’ approaches from global mapping and remote sensing. The trend for increasing wetland extent reported in the literature over time is a consequence of improved mapping technologies and methods rather than a real increase in wetland area, because a continuing trend for natural wetland loss and conversion is documented over the same time period. The most recent high-resolution estimate of global wetland area is in excess of 12.1 × 106 km2, of which 54% is permanently inundated and 46% is temporarily inundated. Globally, 92.8% of continental wetland area is inland and only 7.2% is coastal. Regionally, the largest wetland areas are in Asia (31.8%), North America (27.1%) and Latin America and the Caribbean (Neotropics; 15.8%), with smaller areas in Europe (12.5%), Africa (9.9%) and Oceania (2.9%). It is likely that estimates of global wetland area published to date persist in underestimating the true wetland area. The ‘grand challenge’ of a global inventory integrating all types of permanent and temporary wetlands at high spatial resolution has yet to be fully achieved.

Additional keywords: inventory, Ramsar Convention, remote sensing, wetland area.


References

Agardy, T., and Alder, J. (2005). Chapter 19: coastal systems. In ‘Ecosystems and Human Well-being: Current Status and Trends’. (Eds H. Rashid, R. Scholes, and N. Ash.) pp. 513–549. (Island Press: Washington, DC, USA.)

Aires, F., Papa, F., and Prigent, C. (2013). A long-term, high-resolution wetland dataset over the Amazon Basin, downscaled from a multiwavelength retrieval using SAR data. Journal of Hydrometeorology 14, 594–607.
A long-term, high-resolution wetland dataset over the Amazon Basin, downscaled from a multiwavelength retrieval using SAR data.Crossref | GoogleScholarGoogle Scholar |

Ajtay, G. L., Ketner, P., and Duvigneaud, P. (1979). Terrestrial primary productivity and phytomass. In ‘The Global Carbon Cycle (Scope 13)’. (Eds B. Bolin, E. T. Degens, St Kempe, and P. Ketner.) pp. 129–181. (Wiley: New York, NY, USA.)

Allen, G. H., and Pavelsky, T. M. (2015). Patterns of river width and surface area revealed by the satellite‐derived North American river width data set. Geophysical Research Letters 42, 395–402.
Patterns of river width and surface area revealed by the satellite‐derived North American river width data set.Crossref | GoogleScholarGoogle Scholar |

Aselmann, I., and Crutzen, P. J. (1989). Global distribution of natural freshwater wetlands and rice paddies, their net primary productivity, seasonality and possible methane emissions. Journal of Atmospheric Chemistry 8, 307–358.
Global distribution of natural freshwater wetlands and rice paddies, their net primary productivity, seasonality and possible methane emissions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXhtFGqtA%3D%3D&md5=93ff2e5f36b1679415846b78bf607f50CAS |

Bartholomé, E., and Belward, A. S. (2005). GLC 2000: a new approach to global land cover mapping from Earth observation data. International Journal of Remote Sensing 26, 1959–1977.
GLC 2000: a new approach to global land cover mapping from Earth observation data.Crossref | GoogleScholarGoogle Scholar |

Biancamaria, S., Lettenmaier, D. P., and Pavelsky, T. M. (2016). The SWOT mission and its capabilities for land hydrology. Surveys in Geophysics 37, 307–337.
The SWOT mission and its capabilities for land hydrology.Crossref | GoogleScholarGoogle Scholar |

Botsch, M. S. (Ed.) (2000). Wetlands in Russia. Volume 2: important peatlands. Wetlands International Global Series 2. Wetlands International, Wageningen, Netherlands.

Chapman, B., McDonald, K., Shimada, M., Rosenqvist, A., Schroeder, R., and Hess, L. (2015). Mapping regional inundation with spaceborne L-Band SAR. Remote Sensing 7, 5440–5470.
Mapping regional inundation with spaceborne L-Band SAR.Crossref | GoogleScholarGoogle Scholar |

Chen, L., and Chen, J. (2014). Global wetland mapping (GlobalLand30). Report to Ramsar Convention Secretariat, Gland, Switzerland.

Chen, J., Chen, J., Liao, A., Cao, X., Chen, L., Chen, X., He, C., Han, G., Peng, S., Lu, M., Zhang, W., Tong, X., and Mills, J. (2015). Global land cover mapping at 30 m resolution: a POK-based operational approach. ISPRS Journal of Photogrammetry and Remote Sensing 103, 7–27.
Global land cover mapping at 30 m resolution: a POK-based operational approach.Crossref | GoogleScholarGoogle Scholar |

Cromarty, P., and Scott, D. A. (Eds) (1995). ‘A Directory of Wetlands in New Zealand.’ (Department of Conservation: Wellington, New Zealand.)

Dahl, T. E. (2011). Status and trends of wetlands in the conterminous United States 2004 to 2009. US Department of the Interior, US Fish and Wildlife Service, Fisheries and Habitat Conservation, Washington DC, USA.

Darras, S., Michou, M., and Sarrat, C. (1999). IGBP-DIS Wetlands data initiative, a first step towards identifying a global delineation of wetlands. IGBP-DIS Working Paper 19. IGBP-DIS Office, Toulouse, France.

Davidson, N. C. (2014). How much wetland has the world lost? Long-term and recent trends in global wetland area. Marine and Freshwater Research 65, 934–941.
How much wetland has the world lost? Long-term and recent trends in global wetland area.Crossref | GoogleScholarGoogle Scholar |

Dixon, M. J. R., Loh, J., Davidson, N. C., Beltrame, C., Freeman, R., and Walpole, M. (2016). Tracking global change in ecosystem area: the Wetland Extent Trends index. Biological Conservation 193, 27–35.
Tracking global change in ecosystem area: the Wetland Extent Trends index.Crossref | GoogleScholarGoogle Scholar |

Donchyts, G., Baart, F., Winsemius, H., Gorelick, N., Kwadijk, J., and van de Giesen, N. (2016). Earth’s surface water change over the past 30 years. Nature Climate Change 6, 810–813.
Earth’s surface water change over the past 30 years.Crossref | GoogleScholarGoogle Scholar |

Downing, J. A., Prairie, Y. T., Cole, J. J., Duarte, C. M., Tranvik, L. J., Striegl, R. G., McDowell, W. H., Kortelainen, P., Caraco, N. F., Melack, J. M., and Middelburg, J. J. (2006). The global abundance and size distribution of lakes, ponds, and impoundments. Limnology and Oceanography 51, 2388–2397.
The global abundance and size distribution of lakes, ponds, and impoundments.Crossref | GoogleScholarGoogle Scholar |

Environment Australia (2001). ‘A Directory of Important Wetlands in Australia’, 3rd edn. (Environment Australia: Canberra, ACT, Australia.)

Esser, G. (1984). Significance of carbon pools for the atmospheric CO2: a proposed model structure. In ‘Interaction between Climate and Biosphere’. (Eds H. Lieth, R. Fantechi, and H. Schnitzler.) pp. 253–294. (Swets and Zeitlinger: Lisse, Netherlands.)

Finlayson, C. M., and Spiers, A. G. (Eds) (1999). Global review of wetland resources and priorities for wetland inventory (GRoWI). Supervising Scientist Report 144 and Wetlands International Publication 53, Supervising Scientist, Canberra, ACT, Australia.

Finlayson, C. M., and van der Valk, A. G. (Eds) (1995). ‘Classification and Inventory of the World’s Wetlands.’ Advances in Vegetation Science 16. (Kluwer Academic Publishers: Dordrecht, Netherlands.)

Finlayson, C. M., Davidson, N. C., Spiers, A. G., and Stevenson, N. J. (1999). Global wetland inventory – status and priorities. Marine and Freshwater Research 50, 717–727.
Global wetland inventory – status and priorities.Crossref | GoogleScholarGoogle Scholar |

Finlayson, C. M., Milton, G. R., and Prentice, C. (2016). Wetland types and distribution. In ‘The Wetland Book 2. Distribution, Description and Conservation’. (Eds C. M. Finlayson, G. R. Milton, C. Crawford, and N. C. Davidson.) pp. 19–35. (Springer: Dordrecht, Netherlands.)

Fluet-Chouinard, E., Lehner, B., Rebelo, L.-M., Papa, F., and Hamilton, S. K. (2015). Development of a global inundation map at high spatial resolution from topographic downscaling of coarse-scale remote sensing data. Remote Sensing of Environment 158, 348–361.
Development of a global inundation map at high spatial resolution from topographic downscaling of coarse-scale remote sensing data.Crossref | GoogleScholarGoogle Scholar |

Friedl, M. A., McIver, D. K., Hodges, J. C. F., Zhang, X. Y., Muchoney, D., Strahler, A. H., Woodcock, C. E., Gopal, S., Schneider, A., Cooper, A., Baccini, A., Gao, F., and Schaaf, C. (2002). Global land cover mapping from MODIS: Algorithms and early results. Remote Sensing of Environment 83, 287–302.
Global land cover mapping from MODIS: Algorithms and early results.Crossref | GoogleScholarGoogle Scholar |

Gallant, A. L. (2015). The challenges of remote monitoring of wetlands. Remote Sensing 7, 10938–10950.
The challenges of remote monitoring of wetlands.Crossref | GoogleScholarGoogle Scholar |

Giri, C., Ochieng, E., Tieszen, L. L., Zhu, Z., Singh, A., Loveland, T., Masek, J., and Duke, N. (2011). Status and distribution of mangrove forests of the world using earth observation satellite data. Global Ecology and Biogeography 20, 154–159.
Status and distribution of mangrove forests of the world using earth observation satellite data.Crossref | GoogleScholarGoogle Scholar |

Gong, P., Niu, Z. G., Cheng, X., Zhao, K. Y., Zhou, D. M., Zhao, K. Y., Zhao, H., Li, N. N., Huang, H. B., Li, C. C., Yang, J., Liu, C. X., Liu, S., Wang, L., Li, Z., Yang, Z. Z., Qiao, F., Zheng, Y. M., Chen, Y. L., Sheng, Y. W., Gao, X. H., Zhu, W. H., Wang, W. Q., Wang, H., Weng, Y. L., Zhuang, D. F., Liu, J. Y., Luo, Z. C., Cheng, X., Guo, Z. Q., and Gong, P. (2010). China’s wetland change (1990–2000) determined by remote sensing. Science China. Earth Sciences 53, 1036–1042.
China’s wetland change (1990–2000) determined by remote sensing.Crossref | GoogleScholarGoogle Scholar |

Hu, S., Zhenguo, N., and Chen, Y. (2017). Global wetland datasets: a review. Wetlands 37, 807–817.
Global wetland datasets: a review.Crossref | GoogleScholarGoogle Scholar |

Hughes, R. H., and Hughes, J. S. (1992). ‘A Directory of African Wetlands.’ (IUCN: Gland, Switzerland; UNEP: Nairobi, Kenya; and UNEP-WCMC: Cambridge, UK.)

Junk, W. J., Shuqing, A., Finlayson, C. M., Gopal, B., Kvet, J., Mitchell, S. A., Mitsch, W. J., and Robarts, R. D. (2013). Current state of knowledge regarding the world’s wetlands and their future under global climate change: a synthesis. Aquatic Sciences 75, 151–167.
Current state of knowledge regarding the world’s wetlands and their future under global climate change: a synthesis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXjtVagtw%3D%3D&md5=b50765d81990ca17e178bb2344f44666CAS |

Krivenko, V. G. (Ed.) (1999). Wetlands in Russia. Volume 1: Wetlands of International Importance, Wetlands International – AEME Publication 52. Wetlands International, Wageningen, Netherlands.

Krivenko, V. G. (Ed.) (2000). Wetlands in Russia. Volume 3: wetlands on the Ramsar shadow list, Wetlands International Global Series 6. Wetlands International, Wageningen, Netherlands.

Lehner, B., and Döll, P. (2004). Development and validation of a global database of lakes, reservoirs and wetlands. Journal of Hydrology 296, 1–22.
Development and validation of a global database of lakes, reservoirs and wetlands.Crossref | GoogleScholarGoogle Scholar |

Lehner, B., Reidy Liermann, C., Revenga, C., Vörösmarty, C., Fekete, B., Crouzet, P., Döll, P., Endejan, M., Frenken, K., Magome, J., Nilsson, C., Robertson, J., Rödel, R., Sindorf, N., and Wisser, D. (2011). High resolution mapping of the world’s reservoirs and dams for sustainable river flow management. Frontiers in Ecology and the Environment 9, 494–502.
High resolution mapping of the world’s reservoirs and dams for sustainable river flow management.Crossref | GoogleScholarGoogle Scholar |

Lucas, R., Rebelo, L.-M., Fatoyinbo, L., Rosenqvist, A., Itoh, T., Shimada, M., Simard, M., Souza-Filho, P. W., Thomas, N., Trettin, C., Accad, A., Carreiras, J., and Hilarides, L. (2014). Contribution of L-band SAR to systematic global mangrove monitoring. Marine and Freshwater Research 65, 589–603.
Contribution of L-band SAR to systematic global mangrove monitoring.Crossref | GoogleScholarGoogle Scholar |

MacKay, H. M., Finlayson, C. M., Fernandez-Prieto, D., Davidson, N. C., Pritchard, D., and Rebelo, L.-M. (2009). The role of Earth observation (EO) technologies in supporting the implementation of the Ramsar Convention on Wetlands. Journal of Environmental Management 90, 2234–2242.
The role of Earth observation (EO) technologies in supporting the implementation of the Ramsar Convention on Wetlands.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD1MzivFylug%3D%3D&md5=c8f98b85ebb1fea60981aa4cf1f4d613CAS |

Matthews, E., and Fung, I. (1987). Methane emission from natural wetlands: global distribution, area and environmental characteristics of sources. Global Biogeochemical Cycles 1, 61–86.
Methane emission from natural wetlands: global distribution, area and environmental characteristics of sources.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2sXkvVentr8%3D&md5=54fa1841e70f8574fe5323b2fee87100CAS |

Messager, M. L., Lehner, B., Grill, G., Nedeva, I., and Schmitt, O. (2016). Estimating the volume and age of water stored in global lakes using a geo-statistical approach. Nature Communications 7, 13603.
Estimating the volume and age of water stored in global lakes using a geo-statistical approach.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC28XitFamsbvK&md5=0350373f84412b680c4b1a134be0b1ffCAS |

Nakaegawa, T. (2012). Comparison of water-related land cover types in six 1-km global land cover datasets. Journal of Hydrometeorology 13, 649–664.
Comparison of water-related land cover types in six 1-km global land cover datasets.Crossref | GoogleScholarGoogle Scholar |

Niu, Z. G., Zhang, H. Y., Wang, X. W., Yao, W. B., Zhou, D. M., Zhao, K. Y., Zhao, H., Li, N. N., Huang, H. B., Li, C. C., Yang, J., Liu, C. X., Liu, S., Wang, L., Li, Z., Yang, Z. Z., Qiao, F., Zheng, Y. M., Chen, Y. L., Sheng, Y. W., Gao, X. H., Zhu, W. H., Wang, W. Q., Wang, H., Weng, Y. L., Zhuang, D. F., Liu, J. Y., Luo, Z. C., Cheng, X., Guo, Z. Q., and Gong, P. (2012). Mapping wetland changes in China between 1978 and 2008. Chinese Science Bulletin 57, 2813–2823.
Mapping wetland changes in China between 1978 and 2008.Crossref | GoogleScholarGoogle Scholar |

Nivet, C., and Frazier, S. (2004). A review of European wetland inventory information. Wetlands International, Wageningen, Netherlands.

Ozesmi, S. L., and Bauer, M. E. (2002). Satellite remote sensing of wetlands. Wetlands Ecology and Management 10, 381–402.
Satellite remote sensing of wetlands.Crossref | GoogleScholarGoogle Scholar |

Papa, F., Prigent, C., Aires, F., Jimenez, C., Rossow, W. B., and Matthews, E. (2010). Interannual variability of surface water extent at the global scale, 1993–2004. Journal of Geophysical Research – Atmospheres 115, D12111.
Interannual variability of surface water extent at the global scale, 1993–2004.Crossref | GoogleScholarGoogle Scholar |

Pekel, J. F., Cottam, A., Gorelick, N., and Belward, A. S. (2016). High-resolution mapping of global surface water and its long-term changes. Nature 540, 418–422.
High-resolution mapping of global surface water and its long-term changes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC28XitVWmurbJ&md5=e4953f0ef4e25a585f9e39b4740f928eCAS |

Policelli, F., Slayback, D., Brakenridge, B., Nigro, J., Hubbard, A., Zaitchik, B., Carroll, M., and Jung, H. (2017). The NASA global flood mapping system: final draft. In ‘Remote Sensing of Hydrological Extremes’. (Ed. V. Lakshmi.) pp. 47–63. (Springer International Publishing: Dordrecht, Netherlands.)

Prigent, C., Papa, F., Aires, F., Rossow, W. B., and Matthews, E. (2007). Global inundation dynamics inferred from multiple satellite observations 1993–2000. Journal of Geophysical Research – Atmospheres 112, D12107.
Global inundation dynamics inferred from multiple satellite observations 1993–2000.Crossref | GoogleScholarGoogle Scholar |

Ramsar Convention (2002). Resolution VIII.6: a Ramsar framework for wetland inventory. (Ramsar Convention Secretariat: Gland, Switzerland.) Available at http://www.ramsar.org/sites/default/files/documents/library/key_res_viii_06_e.pdf [Verified 28 October 2017].

Ramsar Convention Secretariat (2015). Ramsar COP12 DOC.8. Report of the Secretary General to COP12 on the implementation of the Convention. (Ramsar Convention Secretariat: Gland, Switzerland.) Available at http://www.ramsar.org/sites/default/files/documents/library/cop12_doc08_report_sg_e.pdf [Verified 28 October 2017].

Ramsar Convention Secretariat (2016). Draft format for national reports to COP13. (Ramsar Convention Secretariat: Gland, Switzerland.) Available at http://www.ramsar.org/sites/default/files/documents/library/sc52-13_cop13_nrform_e.pdf [Verified 28 October 2017].

Reis, V., Hermoso, V., Hamilton, S. K., Ward, D., Fluet-Chouinard, E., Lehner, B., and Linke, S. (2017). A global assessment of inland wetland conservation status. Bioscience 67, 523–533.
A global assessment of inland wetland conservation status.Crossref | GoogleScholarGoogle Scholar |

Rosenqvist, A., Shimada, M., Ito, N., and Watanabe, M. (2007). ALOS PALSAR: a Pathfinder mission for global-scale monitoring of the environment. IEEE Transactions on Geoscience and Remote Sensing 45, 3307–3316.
ALOS PALSAR: a Pathfinder mission for global-scale monitoring of the environment.Crossref | GoogleScholarGoogle Scholar |

Sahagian, K., and Melack, J. (Eds) (1998). Global wetland distribution and functional characterization: trace gases and the hydrologic cycle. International Geosphere-Biosphere Programme (IGBP) Report 46, IGBP, Stockholm, Sweden.

Salmon, J. M., Friedl, M. A., Frolking, S., Wisser, D., and Douglas, E. M. (2015). Global rain-fed, irrigated, and paddy croplands: a new high resolution map derived from remote sensing, crop inventories and climate data. International Journal of Applied Earth Observation and Geoinformation 38, 321–334.
Global rain-fed, irrigated, and paddy croplands: a new high resolution map derived from remote sensing, crop inventories and climate data.Crossref | GoogleScholarGoogle Scholar |

Schroeder, R., McDonald, K. C., Chapman, B. D., Jensen, K., Podest, E., Tessler, Z. D., Bohn, T. J., and Zimmermann, R. (2015). Development and evaluation of a multi-year fractional surface water data set derived from active/passive microwave remote sensing data. Remote Sensing 7, 16688–16732.
Development and evaluation of a multi-year fractional surface water data set derived from active/passive microwave remote sensing data.Crossref | GoogleScholarGoogle Scholar |

Scott, D. A. (Ed.) (1989). ‘A Directory of Asian Wetlands.’ (IUCN: Gland, Switzerland, and Cambridge, UK.)

Scott, D. A. (Ed.) (1993). ‘A Directory of Wetlands in Oceania.’ (IUCN: Gland, Switzerland; and Asian Wetland Bureau (AWB): Kuala Lumpur, Malaysia.)

Scott, D. A. (Ed.) (1995). ‘A Directory of Wetlands in the Middle East.’ (IUCN: Cambridge, UK; and International Waterfowl Research Bureau (IWRB): Slimbridge, UK.)

Scott, D. A., and Carbonell, M. (Eds) (1986). ‘A Directory of Neotropical Wetlands.’ (IUCN: Cambridge; and International Waterfowl Research Bureau (IWRB): Slimbridge, UK.)

Tarnocai, C. (1984). Peat resources of Canada. National Research Council Canada (NRCC) number 24140, NRCC and Land Resource Research Institute, Agriculture Canada, Ottawa, Canada.

Whigham, D., Dykyjova, D., and Hejny, S. (1993). ‘Wetlands of the World: Inventory, Ecology and Management. Volume 1.’ (Kluwer Academic Publishers: Dordrecht, Netherlands.)

Wood, E. F., Roundy, J. K., Troy, T. J., van Beek, L. P. H., Bierkens, M. F. P., Blyth, E., de Roo, A., Döll, P., Ek, M., Famiglietti, J., Gochis, D., van de Giesen, N., Houser, P., Jaffé, P. R., Kollet, S., Lehner, B., Lettenmaier, D. P., Peters-Lidard, C., Sivapalan, M., Sheffield, J., Wade, A., and Whitehead, P. (2011). Hyperresolution global land surface modelling: meeting a grand challenge for monitoring Earth’s terrestrial water. Water Resources Research 47, W05301.
Hyperresolution global land surface modelling: meeting a grand challenge for monitoring Earth’s terrestrial water.Crossref | GoogleScholarGoogle Scholar |

Zhang, B., Tian, H., Lu, C., Chen, G., Pan, S., Anderson, C., and Poulter, B. (2017). Methane emissions from global wetlands: an assessment of the uncertainty associated with various wetland extent data sets. Atmospheric Environment 165, 310–321.
Methane emissions from global wetlands: an assessment of the uncertainty associated with various wetland extent data sets.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2sXhtFGmu7rM&md5=02eef17878ba1c210cbd7ee58ff17dc6CAS |