STUDY OF GEOMORPHOLOGICAL CHANGES IN THE COASTLINE OF SURABAYA, INDONESIA USING REMOTE SENSING DATA

The coastline in Surabaya, Indonesia is about 47.4 kilometers and lies in twenty city subdistricts. One of the main problems in coastal Surabaya is bank erosion. This process has a negative impact on the coastal infrastructure and residential areas of the city, and leads to the degradation of natural landscapes such as mangroves area in Surabaya. The aim of this research was to study the modern coastal processes of the Surabaya coast and analyze the geomorphological changes for the period from 1994 to 2018. Data used in this research were from Landsat TM 5 1994 (8 July 1994) and Landsat 8 OLI 2018 (17 May 2018) and coastal field surveys. The method was the spatial-temporal analysis of the coastline position for twenty-four years (1994–2018) by combining satellite images and conducting sub-satellite observations. In 1994–2018, coastal erosion was recorded in some sub-districts: Tambak Osowilangun, Tambak Langon, Greges and Kalianak (West Surabaya); Moro Krembangan, Ujung, Bulak Banteng, and Kedung Cowek (North Surabaya); Keputih, and Wonorejo and Medokan Ayu (East Surabaya). The most intense coastal retreat (erosion) was observed in the Wonorejo sub district (about 141637.1 m2). Measures that have been taken by the community of Wonorejo was the planting of mangrove trees. The area of man-made coasts increased due to the construction of the new port of Teluk Lamong by 916068.3 m2.

coastline, remote sensing, abrasion, accumulation, coastal processes, mangrove forests, Surabaya, Indonesia