The simulation of urban development with the consideration of ground deformation threats in Sidoarjo Regency, East Java Province of Indonesia

Abstract

Sidoarjo plays a role as buffer zone for the expanding urban growth of Surabaya City, which results in the rapid development of built areas. After the Lapindo mudflow in 2006, subsidence occurred in the surrounding area of Porong District. Land subsidence is a slow-onset disaster that impact people's lives due to vertical displacement. Urban development in areas that are geologically prone to subsidence may have long-term impacts, both on settlements and infrastructure. Therefore, it is necessary to acknowledge its ground deformation trait and how it interacts with urban spatial development. The characteristics of ground deformation were identified utilizing Interferometric Synthetic Aperture Radar (InSAR) processing with Small Baseline Subset (SBAS) method which resulted in 10 levels of ground deformations. The map of ground deformation level was overlaid with the map of future land use of 2041 which was generated from Cellular Automata (CA) based land use simulation. Areas with alarming ground deformation level, that are “at-risk”, are found around the Lapindo area, and extends to Sidoarjo's north side. Meanwhile, the built area is estimated to grow around the major roads, in the central side from north to south, and in the middle-south part of Sidoarjo. The interaction between urban development and ground deformation provides an overview of areas that may encounter ground deformation threats, such as land subsidence and uplift movement, in the future. The results of this study can be used for spatial planning decisions with consideration of ground deformation threats by directing urban development to the “safe” areas.