Study of dynamics of coastal sediment cell boundary in Cirebon coastal area based on integrated shoreline Montecarlo model and remote sensing data

Abstract

The dynamics of the coastal cell boundary in the Cirebon coast have been investigated. The edge of the sediment cell is unique, with a river mouth and very active shoreline movement. A groin-like structure model with the sediment output at the end of the structure is solved analytically using Laplace transforms methods. The morphological changes of these cell sediment boundaries were analyzed using modeling, field measurements, and Landsat satellite data. The study area consists of a single cell with boundaries of fine sediments containing coral fractions. The middle cell is generally a beach with mangroves with fish or a salt pond beach. The observations using Landsat imagery from 1978 to 2021 show changes in the boundary of sediment cells moving forward to the west as far as 1230 m. We use 1985 as the initial cell boundary for our modeling, with a cell boundary length of 1200 m from the shoreline. The first scenario with constant sediment rate input get shoreline changes from 1100 m from the cell boundary. Still, a linear sediment rate results in the coastline moving upward to 1190 m. The third scenario with periodic sediment input with a monsoon period gives a coastline addition of 750 m at the estuary of the cell boundary and erosion (240 m) in an area far from the cell boundary. The Montecarlo simulation generates a breaking wave with a Gaussian random function that produces a breaking wave height with a dominant variation between 0.5 - 1.5 m. The evolution of the coastline with a constant sediment rate resulted in the most developed beach as far as 1000 m with a relatively large chance of reaching 4000. As for the linear rate, producing a coastline with the highest probability of about 1200 m and periodic sediment rates created the most significant for the coastline between 1000–2500 m.