Gerbangkertosusila
Gerbangkertosusila or Gerbangkertosusilo refers to Surabaya 'Extended' Metropolitan Area, East Java.
Gerbangkertosusila is an official acronym of "Gresik Bangkalan Mojokerto Surabaya Sidoarjo Lamongan", a main metropolitan or planning area in East Java consisting of the seven cities and regencies with those names (Mojokerto is both a city and a regency). This acronym corresponds with the definition of "Zona Surabaya Pengaruh Raya" or Extended Metropolitan Area. It has an area of 5,925.843 km2, and at the 2010 Census had a population of 9,115,485.
One definition, by the East Java Provincial Regulation No.4/1996, equates Gerbangkertosusila with the Surabaya Extended Metropolitan Area surrounding Surabaya, entirely in East Java province, Indonesia. This region as an "urban" economic planning area.
The national government regards the Surabaya Metropolitan Area as including only Surabaya, Sidoarjo Regency, and Gresik Regency, known as "Zona Surabaya Raya". Gresik Regency contains the Bawean Island, some 196 km2, which is not part of the built up area but is nevertheless included. Surabaya traditionally constituted Indonesia's second-largest metropolitan area, after Jakarta, but fast growing Bandung (in West Java) is now more populous. However, the extended metropolitan area of Surabaya is second in Indonesia only to Jabodetabek, hence Surabaya's nickname as "second city".
Gerbangkertosusila borders the Malang Metropolitan Area (Malang Raya) to the south. Together the two comprise 12.5 million people.
Reference: *Statistics Indonesia
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