{{Short description|Delta of the Amazon River at its mouth in northern Brazil}} {{Infobox landform | water = | name = Amazon Delta | native_name= {{Native name|pt|Delta do Amazonas}} | type = River delta | image = Amazon_River_ESA387332.jpg | caption = Satellite image of the Amazon Delta captured by NASA in 2005 | elevation = | elevation_ref = | pushpin_map = Brazil | pushpin_relief = 1 | map_caption = Location in Brazil | pushpin_label_position = none | location = North Region, Brazil | coordinates = {{coord|0|08|04|N|50|25|33|W||display=inline,title}} <!--{{coord|0.202|N|49.106|W|scale:1500000|display=inline,title}} --> | topo = | age = | volcanic_arc/belt = | last_eruption = | free_label_1 = States | free_data_1=Amapá, Pará }} The '''Amazon Delta''' ({{langx|pt|delta do Amazonas}}) is a vast river delta formed by the Amazon River and the Tocantins River (through the Pará River distributary channel) in northern South America.<ref>{{cite book |title=Geografia do Brasil: Região norte |publisher=Instituto Brasileiro de Geografia e Estatística (IBGE) |year=1977 |location=Rio de Janeiro}}</ref><ref>{{Cite journal |last1=de Araujo Barbosa |first1=C. C. |last2=Atkinson |first2=P. |last3=Dearing |first3=J. |date=December 2014 |title=The spatial extent of change in tropical forest ecosystem services in the Amazon delta |journal=AGU Fall Meeting Abstracts |location=United States |publisher=ADS Abstract Service (Harvard University) |volume=2014 |pages=PA21A–11 |bibcode=2014AGUFMPA21A..11D}}</ref><ref>{{Cite web |title=NASA Images: STS046-80-009 > Mouths of the Amazon River, Brazil, South America |url=https://images.nasa.gov/details-STS046-80-009.html|website=images.nasa.gov|publisher=NASA|url-status=dead|archive-url=https://web.archive.org/web/20200328112002/https://images.nasa.gov/details-STS046-80-009.html|archive-date=2020-03-28|location=United States}}</ref> It is located in the Brazilian states of Amapá and Pará<ref>{{cite web |year=2015 |title=Fapespa participa de workshop sobre indicadores de vulnerabilidade do Delta do Amazonas |url=http://www.fapespa.pa.gov.br/noticia/1011 |url-status=live |archive-url=https://web.archive.org/web/20200226211553/http://www.fapespa.pa.gov.br/noticia/1011 |archive-date=2020-02-26 |access-date=2020-03-27 |publisher=FAPESPA |ref={{harvid|FAPESPA|2015}}}}</ref> and encompasses the Marajó Archipelago, with Marajó Island as its largest island. The region is 160,000 km2 and has 49 towns, with most of these being small towns with less than 20,000 inhabitants.<ref>{{Cite journal |last1=Carmo |first1=Monique Bruna Silva do |last2=Costa |first2=Sandra Maria Fonseca da |last3=Brondizio |first3=Eduardo S. |date=May 2023 |title=Singularities and Similarities of Amazonia's Small Towns: A Comparative Analysis of Urban Categorizations and Typologies of the Amazon Estuary-Delta Region = Singularidades e semelhanças das pequenas cidades amazônicas: uma análise comparativa das categorizações e tipologias urbanas da região do estuário-delta amazônico |url=https://dx.doi.org/10.1353/lag.2023.a899556 |journal=Journal of Latin American Geography |volume=22 |issue=1 |pages=116–142 |doi=10.1353/lag.2023.a899556}}</ref> The main cities located in the vicinity are Belém and Macapá, each with its respective metropolitan area.<ref>{{cite book |last=Benchimol |first=Samuel |title=Manual de introdução 'a Amazônia |publisher=Edição Reprográfica |location=Manaus}}</ref>
It is the largest river delta in the world. It releases one fifth of the total amount of freshwater that is discharged into the earths oceans, into the Atlantic Ocean, with some estimating that equates to 200,000 litres a second. The area has wetlands, streams, lagoons and rich ecosystems and biodiversity. It is a vital area for wildlife, with extensive mangroves in wetland forests, that cover an area of 38,304 km2 of the delta, with 75% of Brazil's mangroves located in the Amazon Delta.<ref>{{Cite web|title=The Amazon Delta – Vast Labyrinth of Waterways Between Macapá and Belém|url=https://highburynomad.com/the-amazon-delta-macapa-and-belem/|website=Highbury Nomad|date=2018-10-24|access-date=2026-01-30|language=en-GB}}</ref><ref>{{Cite journal|title=The novel mangrove environment and composition of the Amazon Delta|url=https://www.sciencedirect.com/science/article/pii/S0960982222010764|journal=Current Biology|date=2022-08-22|issn=0960-9822|pages=3636–3640.e2|volume=32|issue=16|doi=10.1016/j.cub.2022.06.071|first1=Angelo F.|last1=Bernardino|first2=Ana Carolina A.|last2=Mazzuco|first3=Fernanda M.|last3=Souza|first4=Thuareag M. T.|last4=Santos|first5=Christian J.|last5=Sanders|first6=Carlos G.|last6=Massone|first7=Rodolfo F.|last7=Costa|first8=Antônio Elves B.|last8=Silva|first9=Tiago O.|last9=Ferreira|first10=Gabriel N.|last10=Nóbrega|first11=Thiago S. F.|last11=Silva|first12=J. Boone|last12=Kauffman |pmid=35863350 |bibcode=2022CBio...32E3636B |hdl=1893/34759|hdl-access=free}}</ref><ref>{{Cite web|title=The Amazon: A Forest of Rivers|url=https://amazonfrontlines.org/chronicles/the-amazon-a-forest-of-rivers/|website=Amazon Frontlines|date=2024-04-22|access-date=2026-01-30|language=en-US}}</ref><ref>{{Cite journal|title=Sustainable Management, Conservation, and Restoration of the Amazon River Delta and Amazon-Influenced Guianas Coast: A Review|journal=Water|date=2021-05-14|issn=2073-4441|pages=1371|volume=13|issue=10|doi=10.3390/w13101371|language=en|first1=Edward J.|last1=Anthony|first2=Eduardo S.|last2=Brondizio|first3=Valdenira F.|last3=dos Santos|first4=Antoine|last4=Gardel|first5=Manon|last5=Besset |doi-access=free |bibcode=2021Water..13.1371A }}</ref>
==Climate== The Amazon Delta has a tropical climate with high humidity and high temperatures. It has a wet season with frequent flooding and a dry season where the delta dries out. The wet season is considered to be January to June, with precipitation peaking in February, March and April. The dry season is July to December, with September, October and November seeing the least rainfall.<ref>{{Cite journal |last1=Rocha |first1=Yuri Antonio da Silva |last2=Lima |first2=Aline Maria Meiguins de |last3=Silva |first3=Cláudio Moisés Santos e |last4=Franco |first4=Vânia dos Santos |last5=Raiol |first5=Lucas Lima |last6=Oliveira |first6=Ilziane Simões de |last7=Dias |first7=Maria Luiza Nascimento |last8=Beltrão Júnior |first8=Paulo Roberto Estumano |date=2025-04-15 |title=Hydro-meteorological dynamics of rainfall erosivity risk in the Amazon River Delta-Estuary |url=https://iwaponline.com/jwcc/article/16/5/1673/107883/Hydro-meteorological-dynamics-of-rainfall |journal=Journal of Water and Climate Change |language=en |volume=16 |issue=5 |pages=1673–1694 |doi=10.2166/wcc.2025.544 |bibcode=2025JWCC...16.1673R |issn=2040-2244 |archive-url=http://web.archive.org/web/20250718135131/https://iwaponline.com/jwcc/article/16/5/1673/107883/Hydro-meteorological-dynamics-of-rainfall |archive-date=2025-07-18}}</ref> Extreme flooding occurred in 2009, 2012, 2021, and 2022.<ref name=":1">{{Cite journal |last1=Meiguins de Lima |first1=Aline M |last2=Queiroz do Nascimento |first2=Vitor Gabriel |last3=Siqueira Martins |first3=Saulo |last4=Souza de Oliveira |first4=Arthur Cesar |last5=Antonio da Silva Rocha |first5=Yuri |date=2025 |title=Mass Movements in Wetlands: An Analysis of a Typical Amazon Delta-Estuary Environment |url=https://www.mdpi.com/2624-795X/6/3/40 |journal=GeoHazards |language=en |volume=6 |issue=3 |doi=10.3390/geohazard |doi-broken-date=19 May 2026 |doi-access=free|issn=2624-795X |archive-url=http://web.archive.org/web/20250803104048/https://www.mdpi.com/2624-795X/6/3/40 |archive-date=2025-08-03}}</ref> These seasons shape the environment of the Amazon Delta and the life in it, such as the water buffalo for which Marajó Island is well known, three-toed sloth, capybara, giant anteater, giant otter, jaguar and pink river dolphins.<ref name=":0">{{Cite web |date=2023-10-21|title=Amazon Delta|url=https://www.worldatlas.com/rivers/amazon-delta.html|access-date=2024-10-17|website=WorldAtlas|language=en-US}}</ref>
==Population== Historically, most settlements in the region were by the rivers, for transportation reasons. As these have expanded and small towns have developed along the banks of the watercourse, the floodplain and wetlands have been altered and large areas of vegetation have been cleared, with environmental consequences such as flooding, land movement and erosion.<ref name=":1" />
Over 1.5 million people live locally to the Amazon Delta. The population in the region is growing, with basic infrastructure and public services often lacking, such as sanitation, drinking water, housing and medical care. Housing in the region is often constructed on stilts. Due to these factors, combined with the flooding that occurs in the region, there are health risks to the people living in the region, particularly from waterborne diseases such as cholera and typhoid fever and from vector-borne diseases, such as malaria, yellow fever and dengue.<ref name=":2">{{Cite journal |last1=Mansur |first1=Andressa V. |last2=Brondízio |first2=Eduardo S. |last3=Roy |first3=Samapriya |last4=Hetrick |first4=Scott |last5=Vogt |first5=Nathan D. |last6=Newton |first6=Alice |date=2016-07-01 |title=An assessment of urban vulnerability in the Amazon Delta and Estuary: a multi-criterion index of flood exposure, socio-economic conditions and infrastructure |url=https://doi.org/10.1007/s11625-016-0355-7 |journal=Sustainability Science |language=en |volume=11 |issue=4 |pages=625–643 |doi=10.1007/s11625-016-0355-7 |bibcode=2016SuSc...11..625M |issn=1862-4057}}</ref>
Economic activity stems from industries such as agroforestry, fishing, mining, agriculture, and ranching, with these industries providing employment to people living in the region.<ref name=":2" /> Approximately 50,000 people living in the region rely on natural resource exploitation for employment.<ref>{{Cite journal |last1=de Araujo Barbosa |first1=Caio C. |last2=Atkinson |first2=Peter M. |last3=Dearing |first3=John A. |date=2016-04-15 |title=Extravagance in the commons: Resource exploitation and the frontiers of ecosystem service depletion in the Amazon estuary |url=https://www.sciencedirect.com/science/article/pii/S0048969716300742 |journal=Science of the Total Environment |volume=550 |pages=6–16 |doi=10.1016/j.scitotenv.2016.01.072 |pmid=26803679 |bibcode=2016ScTEn.550....6D |issn=0048-9697}}</ref>
==Marajó archipelago== {{Main|Marajó Archipelago}} The Marajó archipelago is based in the Amazon Delta region and includes 2,500 islands, with Marajó island being the largest. Other large islands include Caviana, Serraria and Mexiana. An area known as the Marajó Várzea ecoregion includes the archipelago's islands and floodplains. Tidal activity from the Atlantic Ocean results in twice daily flooding, as these tides cause the river water to disperse onto land. This creates a unique ecosystem, with fruit eating fish feeding on açaí palm, which is plentiful in the area. There are over 540 known bird species, including the scarlet ibis, black-collared hawk, parrots and macaws. The Amazon river dolphin can be found in the area, as well as water buffalo. It is designated as a protected area to help to safeguard it and to prevent ecological damage, known as the Marajó Archipelago Environmental Protection Area.<ref>{{Cite web |date=2024-06-21 |title=Marajó Archipelago: Brazil's Ecological & Cultural Treasure |url=https://lacgeo.com/marajo-archipelago-brazil |access-date=2026-02-23 |website=lacgeo.com}}</ref><ref>{{Cite web |date=2024-10-13 |title=Tides of Life: The Marajó Várzea Ecosystem |url=https://lacgeo.com/marajo-varzea-ecoregion |access-date=2026-02-23 |website=lacgeo.com}}</ref>
==Untypical delta== Due to the vast amounts of sediment and freshwater released by the Amazon, the delta is not a traditional one, for example in shape.<ref name=":0" /> The sedimentary environment near the Amazon's mouth has limited subaerial expression, untypical of a river delta.<ref>{{Cite journal|title=The deltaic nature of Amazon shelf sedimentation|url=https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/97/4/444/203177/the-deltaic-nature-of-amazon-shelf-sedimentation?redirectedFrom=fulltext|journal=Geological Society of America Bulletin|date=1986|issn=0016-7606|pages=444|volume=97|issue=4|doi=10.1130/0016-7606(1986)97<444:TDNOAS>2.0.CO;2|archive-url=http://web.archive.org/web/20180602124009/https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/97/4/444/203177/the-deltaic-nature-of-amazon-shelf-sedimentation?redirectedFrom=fulltext|archive-date=2018-06-02|language=en|first1=C. A.|last1=NITTROUER|first2=S. A.|last2=KUEHL|first3=D. J.|last3=DEMASTER|first4=R. O.|last4=KOWSMANN | bibcode=1986GSAB...97..444N |url-access=subscription}}</ref> As a result, some people do not describe it as being a delta.<ref>{{Cite web|title=Delta|url=https://education.nationalgeographic.org/resource/delta|website=education.nationalgeographic.org|access-date=2026-01-30|language=en}}</ref>
==Environmental concerns== In 2025, approval was given to Petrobras to drill in a location 500km from the mouth of the Amazon River.<ref>{{Cite web|title=Brazil grants state oil firm exploration license in Amazon region|url=https://www.bbc.com/news/articles/cm2735yp75ko|website=BBC News|date=2025-10-20|access-date=2026-01-31|language=en-gb}}</ref> This decision raised concerns from environmentalists, with Brazil's Climate Observatory NGO describing this as being "disastrous from an environmental, climate, and sociobiodiversity perspective”.<ref>{{Cite news|title=Brazil greenlights oil drilling in Amazon as environmentalists raise alarm|url=https://www.theguardian.com/world/2025/oct/20/brazil-greenlights-oil-drilling-amazon|work=The Guardian|date=2025-10-20|access-date=2026-01-31|issn=0261-3077|language=en-GB|first=Agence|last=France-Press}}</ref> Oil drilling, which had commenced in October 2025, was put on hold by Brazils oil regulator in January 2026 whilst it sought further information after a leak of synthetic fluid occurred. The company confirmed it had contained the leak and that the fluid released was biodegradable and posed no environmental risk.<ref>{{Cite news |last1=Teixeira |first1=Fabio |last2=Nogueira |first2=Marta |date=2026-01-08 |title=Brazil's oil regulator puts Petrobras drilling at Foz do Amazonas on hold |url=https://www.reuters.com/business/energy/brazils-oil-regulator-puts-petrobras-drilling-foz-do-amazonas-hold-2026-01-08/ |access-date=2026-02-23 |work=Reuters}}</ref> Indigenous communities have raised concerns about the impact of the drilling, and how they were treated in respect of consultation with their communities.<ref>{{Cite web |title=Amazon Indigenous communities face harsh reality of oil drilling |url=https://www.thebureauinvestigates.com/stories/2026-04-30/indigenous-people-face-reality-of-amazon-oil-drilling |access-date=2026-06-01 |website=TBIJ |language=en|date=2026-04-30|last=Milhorance|first=Flávia|first2=Grace|last2=Murray}}</ref>
Other environmental concerns include the impact of climate change and extreme weather events in the region, including flooding,<ref>{{Cite web |last=Blot |first=Oliver |date=2025-10-07 |title=Climate Change Is Submerging the Amazon Estuary |url=https://lemag.ird.fr/en/climate-change-submerging-amazon-estuary |access-date=2026-03-03 |website=lemag.ird.fr |language=en}}</ref> and microplastic pollution.<ref>{{Cite journal |last1=Oliveira Santos |first1=Luana Francy |last2=Neu |first2=Vania |last3=Pereira Monteiro |first3=Raqueline Cristina |last4=Kütter |first4=Vinicius Tavares |last5=Siqueira Morais |first5=Leonardo Mario |last6=Soares-Gomes |first6=Abilio |last7=Chelazzi |first7=David |last8=Giarrizzo |first8=Tommaso |last9=Martinelli Filho |first9=José Eduardo |date=October 2023 |title=Microplastics and microfibers in the Guajará Bay, Amazon delta: Potential sources and variability |url=https://www.sciencedirect.com/science/article/abs/pii/S0025326X23009591 |journal=Marine Pollution Bulletin |volume=195 |article-number=115525 |doi=10.1016/j.marpolbul.2023.115525 |pmid=37708604 |bibcode=2023MarPB.19515525S |via=ScienceDirect}}</ref>
== References == {{reflist}}
Category:River deltas of South America