Analisis Perbandingan Hasil Simulasi Genangan Rob Berdasarkan DEM Foto Udara dan Dem Lidar

Abstrak

Tidal flooding occurs due to fluctuations in sea level influenced by the gravitational forces of celestial bodies, particularly the moon and the sun. In Central Java, Indonesia, the Tambak Lorok area in Semarang frequently faces tidal floods, leading to considerable economic and social losses if not properly managed. To mitigate these risks, it is essential to simulate tidal runoff areas (inundation zones) using the latest Digital Elevation Model (DEM) data. High-resolution DEMs can be produced effectively through photogrammetry and LiDAR UAV techniques, but differences in accuracy and ground penetration between these methods can impact inundation simulations. The complex land cover in Tambak Lorok additionally affects height extraction and tidal flow distribution. This study compares tidal inundation simulations using DEM data from aerial photography and LiDAR. Employing neighborhood operations and iterative methods for simulation, seven sea-level rise scenarios were analyzed: 0.5 m, 0.75 m, 1 m, 1.25 m, 1.5 m, 1.75 m, and 2 m. The inundation areas were calculated, and a concordance ratio (CR) was established to assess the similarity of the results. The average CR across the scenarios was 92.31%, indicating consistency between the two data sources, although the 0.5 m scenario showed an underestimate from the aerial photo DEM compared to LiDAR. This variation was attributed to differing penetration levels, especially along the eastern riverbank of the study area.