{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T17:54:34Z","timestamp":1781114074455,"version":"3.54.1"},"reference-count":55,"publisher":"The Royal Society","issue":"5","license":[{"start":{"date-parts":[[2018,5,1]],"date-time":"2018-05-01T00:00:00Z","timestamp":1525132800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/royalsociety.org\/journals\/ethics-policies\/data-sharing-mining\/"}],"funder":[{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100006754","name":"Army Research Laboratory","doi-asserted-by":"publisher","award":["Cooperative Agreement Number W911NF-09-2-0053 (the"],"award-info":[{"award-number":["Cooperative Agreement Number W911NF-09-2-0053 (the"]}],"id":[{"id":"10.13039\/100006754","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002322","name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100002322","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005283","name":"Funda\u00e7\u00e3o Cearense de Apoio ao Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100005283","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["royalsocietypublishing.org"],"crossmark-restriction":true},"short-container-title":["R. Soc. open sci."],"published-print":{"date-parts":[[2018,5]]},"abstract":"<jats:p>The shape of urban settlements plays a fundamental role in their sustainable planning. Properly defining the boundaries of cities is challenging and remains an open problem in the science of cities. Here, we propose a worldwide model to define urban settlements beyond their administrative boundaries through a bottom-up approach that takes into account geographical biases intrinsically associated with most societies around the world, and reflected in their different regional growing dynamics. The generality of the model allows one to study the scaling laws of cities at all geographical levels: countries, continents and the entire world. Our definition of cities is robust and holds to one of the most famous results in social sciences: Zipf\u2019s law. According to our results, the largest cities in the world are not in line with what was recently reported by the United Nations. For example, we find that the largest city in the world is an agglomeration of several small settlements close to each other, connecting three large settlements: Alexandria, Cairo and Luxor. Our definition of cities opens the doors to the study of the economy of cities in a systematic way independently of arbitrary definitions that employ administrative boundaries.<\/jats:p>","DOI":"10.1098\/rsos.180468","type":"journal-article","created":{"date-parts":[[2018,5,23]],"date-time":"2018-05-23T07:50:29Z","timestamp":1527061829000},"page":"180468","update-policy":"https:\/\/doi.org\/10.1098\/crossmark-policy","source":"Crossref","is-referenced-by-count":14,"title":["A worldwide model for boundaries of urban settlements"],"prefix":"10.1098","volume":"5","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6413-8445","authenticated-orcid":false,"given":"Erneson A.","family":"Oliveira","sequence":"first","affiliation":[{"name":"Programa de P\u00f3s Gradua\u00e7\u00e3o em Inform\u00e1tica Aplicada, Universidade de Fortaleza, 60811-905 Fortaleza, Cear\u00e1, Brazil"},{"name":"Mestrado Profissional em Ci\u00eancias da Cidade, Universidade de Fortaleza, 60811-905 Fortaleza, Cear\u00e1, Brazil"},{"name":"Departamento de F\u00edsica, Universidade Federal do Cear\u00e1, Campus do Pici, 60451-970 Fortaleza, Cear\u00e1, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vasco","family":"Furtado","sequence":"additional","affiliation":[{"name":"Programa de P\u00f3s Gradua\u00e7\u00e3o em Inform\u00e1tica Aplicada, Universidade de Fortaleza, 60811-905 Fortaleza, Cear\u00e1, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jos\u00e9 S.","family":"Andrade","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica, Universidade Federal do Cear\u00e1, Campus do Pici, 60451-970 Fortaleza, Cear\u00e1, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hern\u00e1n A.","family":"Makse","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica, Universidade Federal do Cear\u00e1, Campus do Pici, 60451-970 Fortaleza, Cear\u00e1, Brazil"},{"name":"Levich Institute and Physics Department, City College of New York, New York, NY\u00a010031, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"175","published-online":{"date-parts":[[2018,5,23]]},"reference":[{"key":"e_1_3_6_2_2","volume-title":"The death and life of the great American cities","author":"Jacobs J","year":"1961"},{"key":"e_1_3_6_3_2","doi-asserted-by":"publisher","DOI":"10.7551\/mitpress\/9399.001.0001"},{"key":"e_1_3_6_4_2","volume-title":"Scale: the universal laws of growth, innovation, sustainability, and the pace of life in organisms, cities, economies, and companies","author":"West G","year":"2017"},{"key":"e_1_3_6_5_2","doi-asserted-by":"publisher","DOI":"10.1038\/377608a0"},{"key":"e_1_3_6_6_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevE.58.7054"},{"key":"e_1_3_6_7_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0807435105"},{"key":"e_1_3_6_8_2","doi-asserted-by":"publisher","DOI":"10.1257\/aer.101.5.2205"},{"key":"e_1_3_6_9_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevE.87.042114"},{"key":"e_1_3_6_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.chaos.2013.01.001"},{"key":"e_1_3_6_11_2","doi-asserted-by":"publisher","DOI":"10.1098\/rsif.2013.0930"},{"key":"e_1_3_6_12_2","first-page":"011008","article-title":"Spatially distributed social complex networks","volume":"4","author":"Frasco GF","year":"2014","journal-title":"Phys. Rev. X"},{"key":"e_1_3_6_13_2","doi-asserted-by":"publisher","DOI":"10.1098\/rsif.2014.0745"},{"key":"e_1_3_6_14_2","doi-asserted-by":"publisher","DOI":"10.1098\/rsif.2015.0763"},{"key":"e_1_3_6_15_2","doi-asserted-by":"publisher","DOI":"10.1098\/rsos.150691"},{"key":"e_1_3_6_16_2","doi-asserted-by":"publisher","DOI":"10.3390\/ijgi5070110"},{"key":"e_1_3_6_17_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0610172104"},{"key":"e_1_3_6_18_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevE.79.016115"},{"key":"e_1_3_6_19_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0013541"},{"key":"e_1_3_6_20_2","doi-asserted-by":"publisher","DOI":"10.1038\/467912a"},{"key":"e_1_3_6_21_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0040393"},{"key":"e_1_3_6_22_2","doi-asserted-by":"publisher","DOI":"10.1038\/srep00454"},{"key":"e_1_3_6_23_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1235823"},{"key":"e_1_3_6_24_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0064727"},{"key":"e_1_3_6_25_2","doi-asserted-by":"publisher","DOI":"10.1038\/srep04235"},{"key":"e_1_3_6_26_2","doi-asserted-by":"publisher","DOI":"10.1038\/srep06239"},{"key":"e_1_3_6_27_2","doi-asserted-by":"publisher","DOI":"10.1038\/srep05561"},{"key":"e_1_3_6_28_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0134862"},{"key":"e_1_3_6_29_2","doi-asserted-by":"publisher","DOI":"10.1057\/palcomms.2015.17"},{"key":"e_1_3_6_30_2","doi-asserted-by":"crossref","first-page":"e0149546","DOI":"10.1371\/journal.pone.0149546","article-title":"Rural to urban population density scaling of crime and property transactions in English and Welsh parliamentary constituencies","volume":"11","author":"Hanley QS","year":"2016","journal-title":"PLoS ONE"},{"key":"e_1_3_6_31_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0171609"},{"key":"e_1_3_6_32_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.physa.2017.11.039"},{"key":"e_1_3_6_33_2","doi-asserted-by":"publisher","DOI":"10.1257\/aer.89.2.129"},{"key":"e_1_3_6_34_2","doi-asserted-by":"publisher","DOI":"10.1162\/003355399556133"},{"key":"e_1_3_6_35_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0166-0462(02)00006-6"},{"key":"e_1_3_6_36_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jue.2007.01.005"},{"key":"e_1_3_6_37_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jue.2010.03.007"},{"key":"e_1_3_6_38_2","doi-asserted-by":"publisher","DOI":"10.1093\/jeg\/lbq019"},{"key":"e_1_3_6_39_2","doi-asserted-by":"publisher","DOI":"10.1080\/13658816.2010.510801"},{"key":"e_1_3_6_40_2","first-page":"107","article-title":"The French overall city size distribution","volume":"36","author":"Giesen K","year":"2012","journal-title":"R\u00e9gion et D\u00e9veloppement"},{"key":"e_1_3_6_41_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jue.2012.06.005"},{"key":"e_1_3_6_42_2","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-444-53540-5.00005-7"},{"key":"e_1_3_6_43_2","doi-asserted-by":"publisher","DOI":"10.1007\/978-4-431-55390-8"},{"key":"e_1_3_6_44_2","volume-title":"Human behavior and the principle of least effort: an introduction to human ecology","author":"Zipf GK","year":"1949"},{"key":"e_1_3_6_45_2","doi-asserted-by":"publisher","DOI":"10.1029\/96JB00177"},{"key":"e_1_3_6_46_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0378-4371(99)00086-2"},{"key":"e_1_3_6_47_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1106612109"},{"key":"e_1_3_6_48_2","unstructured":"Linux Kernel Organization. 2017 Zram: compressed RAM based block devices. See https:\/\/www.kernel.org\/doc\/Documentation\/blockdev\/zram.txt (accessed 1 August 2017)."},{"key":"e_1_3_6_49_2","unstructured":"Center for International Earth Science Information Network (CIESIN)\/Columbia University International Food Policy Research Institute (IFPRI) The World Bank Centro Internacional de Agricultura Tropical (CIAT). 2011 Global Rural-Urban Mapping Project Version 1. See http:\/\/sedac.ciesin.columbia.edu\/data\/collection\/grump-v1 (accessed 01 August 2017)."},{"key":"e_1_3_6_50_2","doi-asserted-by":"publisher","DOI":"10.3133\/pp1395"},{"key":"e_1_3_6_51_2","doi-asserted-by":"publisher","DOI":"10.1137\/070710111"},{"key":"e_1_3_6_52_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0183919"},{"key":"e_1_3_6_53_2","unstructured":"National Aeronautics and Space Administration (NASA). 2016 Visible Infrared Imaging Radiometer Suite (VIIRS). See http:\/\/npp.gsfc.nasa.gov\/viirs.html (accessed 01 August 2017)."},{"key":"e_1_3_6_54_2","unstructured":"Gehad A. 2003 Deteriorated soils in Egypt: management and rehabilitation. See http:\/\/www.fao.org\/tempref\/agl\/agll\/ladadocs\/detsoilsegypt.doc (accessed 1 August 2017)."},{"key":"e_1_3_6_55_2","unstructured":"United Nations. 2016 The world\u2019s cities in 2016. See http:\/\/www.un.org\/en\/development\/desa\/population\/publications\/pdf\/urbanization\/the_worlds_cities_in_2016_data_booklet.pdf (accessed 1 August 2017)."},{"key":"e_1_3_6_56_2","unstructured":"Oliveira EA Furtado V Andrade JS Makse HA. 2018 Data from: A worldwide model for boundaries of urban settlements. Dryad Digital Repository. (http:\/\/dx.doi.org\/10.5061\/dryad.968nq8n)"}],"container-title":["Royal Society Open Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/royalsocietypublishing.org\/doi\/pdf\/10.1098\/rsos.180468","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/royalsocietypublishing.org\/doi\/full-xml\/10.1098\/rsos.180468","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/royalsocietypublishing.org\/doi\/pdf\/10.1098\/rsos.180468","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,2,18]],"date-time":"2021-02-18T03:00:55Z","timestamp":1613617255000},"score":1,"resource":{"primary":{"URL":"https:\/\/royalsocietypublishing.org\/doi\/10.1098\/rsos.180468"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,5]]},"references-count":55,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2018,5]]}},"alternative-id":["10.1098\/rsos.180468"],"URL":"https:\/\/doi.org\/10.1098\/rsos.180468","relation":{},"ISSN":["2054-5703"],"issn-type":[{"value":"2054-5703","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,5]]},"assertion":[{"value":"2018-03-23","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2018-04-03","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2018-05-23","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}