A river island is any exposed land within a river. Properly defined it excludes shoals between seasonally varying flows and may exclude semi-coastal islands such as in deltas.

Islands result from changes in the course of a river such as interactions with a tributary or the opposing fluvial actions of deposition and/or erosion such as forming a natural cut and meander. Nascent vegetation-free sandbars and mudflats may dissipate and shift or build up into such islands through deposition and which may be assisted through artificial reinforcement or natural factors such as, reeds, palms, evergreen trees or willows, to large examples covering many square kilometers, examples of which are given below.

Regional nomenclature

The term "towhead" implies a little islet or sandbar within a river (most often the Mississippi River) having a grouping or thicket of trees, and is often used in the Midwestern United States. Many rivers, if wide enough, can house considerably large islands. The term "towhead" was popularised by Mark Twain's Adventures of Huckleberry Finn.

In England, a river island in the Thames is referred to as an "ait" (or "eyot").

Largest and smallest

Friday Island is a very small example of an island with a solid-foundations house

Majuli in India, being non-coastal and being between two channels of one river is recognised by the Guinness Book of World Records as world's largest example.[1], but Ilha do Bananal meets the same qualifications and is much larger. Umananda is among contenders as the smallest permanently-inhabited river island with fixed dwellings at 0.02 km². Majuli and Umananda lie in the Brahmaputra River. Many as tiny as Umananda or smaller, inhabited, exist in the Amazon basin and Bangladesh. On canalised rivers such as the Thames and the Seine one-home islands of permanent-materials homes exist such as Monkey, Friday, Holm and D'Oyly Carte islands, as canalisation reduces the erosion of the islands and in particular limits the height of flash flooding by maintaining substantial "heads" of water through barrages, see dam.

Lists of river islands

  • Note: Includes some river islands that also have an ocean coast.
Name Area (km²) Country River
Area around Kampala, Uganda 61,000 (approx.) Uganda, Democratic Republic of the Congo Victoria Nile, Katonga River, Kazinga channel, Semliki Riverdebatable
Marajó 40,100 Brazil Amazon River / Pará River
Ilha do Bananal 19,162 Brazil Araguaia River
Tupinambarana 11,850 Brazil Amazon River
Nile Delta 8,964 Egypt Rosetta and Damietta branches of Nile River
Holland/Utrecht 7,361 Netherlands Rhine River IJssel River
Ilha Grande de Gurupá 4,864 Brazil Amazon River
Margarita Island (Colombia) 2,832[2] Colombia Magdalena River
Uarini Island 2,339 Brazil Uarini River, Amazon River
Boven Digul 2,171 Indonesia Digul River, Kawaga River
Richards Island 2,165 Canada Mackenzie River
Krasnoslobodsk 2,002 Russia Volga River, Akhtuba River
Veľký Žitný ostrov 1,885.2[3] Slovakia Danube
Hatiya Island 1,508.23 Bangladesh Meghna River
Letea Island 1,480 Romania Danube River
Camargue 1,453 France Grand Rhone, Petit Rhone
Bhola Island 1,441 Bangladesh Meghna River
Chongming Island 1,267[4] China Yangtze River
Majuli 1,250 India Brahmaputra River
Ile a Mofil 1,250 Senegal Senegal River
Dibru Saikhowa 765 India Brahmaputra River
Sandwip Island 762.42 Bangladesh Meghna River
Great Brăila Island 720.2 Romania Danube
Sumba Island 500[5] Democratic Republic of Congo Congo River
Montreal 499 Canada St. Lawrence River, Ottawa River
Szigetköz 375 Hungary, Slovakia Danube
Manpura Island 373 Bangladesh Meghna
Inhacamba 340 Mozambique Zambezi
Hoeksche Waard 323.74 Netherlands Oude Maas, Nieuwe Maas
Csepel Island 257 Hungary Danube
Île Jésus 242 Canada Rivière des Mille Îles, Rivière des Prairies
Voorne-Putten 220 Netherlands Oude Maas, Nieuwe Maas
Hisingen 199 Sweden Göta älv
Mosqueiro 191 Brazil Amazon River
Mbamou Island 180[6] Republic of the Congo Congo River
Roberts Island 133[7] United States San Joaquin River
Union Island 130[7] United States San Joaquin River
Davis Island 120 United States Mississippi River
Taiama Island 115.55 Brazil Paraguay River
Lulu Island 112.4 Canada Fraser River
Sarpinskiy Island 110 Russia Volga River
Sauvie Island 105 United States Columbia River
Dordrecht Island 79.53 Netherlands Oude Maas, Hollands Diep
Srirangam 74.4 India Kaveri[8]
Grand Island 73.8 United States Niagara River
Ostrvo 60 Serbia Danube
Manhattan Island 59 United States Hudson River/East River
Hengsha Island 55.74 China Yangtze River
Woodford Island 37 Australia Clarence River
Wilhelmsburg 35.3 Germany Elbe
Isla Teja 15 Chile Cau-Cau River/Cruces River/Valdivia River
Srirangapatna 13 India Kaveri
Shivanasamudram [9]India Kaveri
Grosse Ile 25 United States Detroit River
Khortytsia 23.59 Ukraine Dnieper River
Island of Šarengrad 9 Disputed (Serbia/Croatia) Danube
Yeouido 8.4 South Korea Han River
Sedudu/Kasikili 5 Botswana Cuando River
Nanjido 2.8 South Korea a branch of the Han River
Rŭngrado 1.3 North Korea Taedong River
Yanggakdo 1.2[10] North Korea Taedong River
Nakanoshima 0.7 Japan Kyū-Yodo River
Zhenbao Island 0.7 China Ussuri River
Bhavani Island 0.53 India Krishna River
Bamseom 0.24 South Korea Han River
Nakasu ~0.2 Japan Nakagawa River
Island of Vukovar 0.032 Disputed (Serbia/Croatia) Danube
Umananda Island 0.02 India Brahmaputra River
Some Sevit
South Korea Han River
Pheasant Island 0.00682 Condominium between France and Spain Bidasoa

Most populous river islands

Name Population Area [km²] Country City River
Montreal 1,854,442 499 Canada Montreal St. Lawrence River
Manhattan Island 1,634,795 (2008) 59 United States New York City Hudson River/East River
Chongming Island 660,000 (2010) 1,267 China Shanghai Yangtze River
Ile Jesus 401,550 242 Canada Laval St. Lawrence River
Veľký Žitný ostrov 226,446 (2001) 1,885 Slovakia several Danube
Vasilievsky Island 202,650 (2002) 10.9 Russia St. Petersburg Bolshaya Neva/Malaya Neva
Lulu Island 168,162 122.4 Canada Richmond Fraser
Csepel Island 166,953 (2012) 257 Hungary diverse Danube
Majuli 140,000 422 India Vaishnavite Shrines Brahmaputra River
Hisingen 130,000 199 Sweden Gothenburg Göta älv
Wilhelmsburg 49,132 (2006) 35.3 Germany Hamburg Elbe
Yeouido 30,988 (2006) 8.4 South Korea Seoul Han River
Mosqueiro 27,000 191 Brazil Belém Amazon River
Srirangapatna 23,448 (2001) 13 India Srirangapatna Kaveri

See also



  1. ^ Majuli, River Island. "Largest river island". Guinness World Records. Retrieved 6 September 2016. 
  2. ^ "Río Grande de la Magdalena - Colección Ecológica del Banco". Retrieved 3 January 2015. 
  3. ^ "Žitný ostrov". Retrieved 3 January 2015. 
  4. ^ address, author,email. "崇明县". www.shanghai.gov.cn. 
  5. ^ "Largest Islands of Countries". Retrieved 3 January 2015. 
  6. ^ "Malebo Pool". Encyclopædia Britannica. Accessed June 2017.
  8. ^ W. Francis (1906). Gazetteer of South India. p. 199.
  9. ^ Shivanasamudra
  10. ^ Historical Dictionary of Pyongyang, by Justin Corfield, p.227