The Impact of Urban Sprawl on the Decline of Green Open Space in Sattelite Towns in the Surabaya Metropolitan Area

Abstract

Indonesia has made significant progress in economic growth and development. This development progress is followed by rapid urbanization that has made several cities in Indonesia into metropolitan areas, including the Surabaya Metropolitan Area or Gerbangkertosusila area. The city of Surabaya has a population that continues to increase from 1990 to 2010. Still, the population growth rate is lower than that in the surrounding areas, so the suburbs of Surabaya City grow faster. The rapid physical growth of the city in the suburbs that are physically expanding uncontrollably (urban sprawl). Green open space conversion threatens the ecological function of the Surabaya Metropolitan Area to anticipate the negative impacts of urban sprawl. First, this study uses GIS and remote sensing methods to detect urban sprawl spatially through land cover change analysis. Second, identifying spatial patterns and urban sprawl index values. Third, the harmony of existing green space in the Gerbangkertasusila area will be analyzed by overlaying land use maps with the spatial plan. Fourth, analyze spatial policies in the Gerbangkertosusila area through in-depth interviews. This study found that green open space continued to decline from 84.88% in 1995 to 73.56% in 2020; there was an increase in built-up space in 1995 from 4.73% to 13.71% in 2020. There are three patterns of urban sprawl in the Gerbangkertosusila area: Leap frog development, Ribbon Development, and Post-suburbia. The highest value in the urban sprawl index is in Sidoarjo Regency at 4.74 due to the high population growth that triggers rapid urban sprawl. The lowest value in the urban sprawl index is in Bangkalan Regency -7.62 due to lower development pressure. In the harmony analysis, there is a green open space with the most appropriate value in Bangkalan Regency at 93.14% and a suitable built-up space in Sidoarjo Regency at 73.70%. The factors that influence changes in land cover are political, social factors, and economic factors.