The dynamics of shoreline changes concerning the existence of mangrove in Takalar Regency

Abstract

Coastal is an area that vulnerable to change, especially along the shoreline. The changes can occur in the form of abrasion and or accretion. Many factors could be the causes of shoreline changes; one of them is the existence of a mangrove ecosystem. Physically, the function of the mangrove ecosystem is to protect the coastal area from the wave, which can cause an abrasion. It also functions as a sediment trap, which leads to the accretion. The aim of this research is to know the relationship between the existence of mangrove and the shoreline changes along with the Takalar Regency. This research was comparing two years of Landsat Imagery (1998 and 2018) to map the mangrove and the shoreline. The shoreline changes were analyzed using the Digital Shoreline Analysis System (DSAS) application. Meanwhile, the mangrove density was analyzed using the Normalized Difference Vegetation Index (NDVI) analysis. Results show that for 20 years, shoreline changes caused by abrasion was 147,03 m or 7,38 m/year, and changes caused by accretion was 135,34 m or 6,79 m/year. Mangrove area has increased 63,76 Ha along the Takalar Regency shoreline during these 20 years. The relationship analysis between shoreline changes with mangrove density was done using regression analysis. The coefficient regression shows a positive relation, which means there were influences between shoreline changes and mangrove density, but the significant value was 0,25, bigger than 0,05, which indicates there is another significant factor that is more affected the Takalar Regency shoreline beside the mangrove density.