Application of LEI (Landscape Expansion Index) for Monitoring Flood-Prone Areas in Bekasi City in 2005, 2015, and 2025 Agsha Dewantara*, Dinia Izza Rianti, Fauzi Fahmi, Shofura Afanin Nuha, Alfian, Hammam Muhammad Amrullah, Mellinia Regina Heni Prastiwi, Wanda Nelwita Pohan
Remote Sensing Graduate Student, Faculty of Geography, Gadjah Mada University, Yogyakarta, Indonesia
Abstract
Rapid population growth and accelerated urbanization in metropolitan areas, including Bekasi City, indicate uncontrolled land use change. One of its main impacts is the reduction of natural infiltration areas such as rivers, wetlands, and vegetation, which increases surface runoff and exacerbates flood risk. Therefore, it is essential to monitor urban growth spatially and temporally as a foundation for disaster mitigation and land-use management. This study aims to analyze land use changes in Bekasi City in the years 2005, 2015, and 2025, and to identify the directions of urban expansion using the Landscape Expansion Index (LEI) method. Furthermore, the study seeks to map flood-prone areas based on the patterns of built-up area development. The data used includes Landsat 5 imagery (2005), Landsat 7 (2015), and Landsat 9 (2025). Land use classification is performed using the Random Forest machine learning algorithm to distinguish between built-up and non-built-up areas. Subsequently, new built-up zones are analyzed spatially using buffering and overlay techniques to calculate the LEI value for each period. LEI measures the ratio between the edge of new urban patches that adjoin existing built-up areas and the total edge of the new patch. Through this approach, urban expansion patterns such as infill, edge-expansion, or leap-frog can be identified. The LEI analysis reveals the relationship between the direction of urban expansion and increased flood vulnerability. This information is crucial for supporting more adaptive and sustainable spatial planning and serves as a basis for disaster mitigation policy-making in urban areas such as Bekasi City.
Keywords: Flood, Landsat Imagery, Landscape Expansion Index (LEI), Land Use Change, Urbanization
