THE IMPACT SHORELINE MODIFICATIONS ON LEKANG TURTLE (Lepidochelys olivacea) CONSERVATION ALONG COASTAL OF KULONPROGRO, INDONESIA

Abstract

Changes in oceanographic circumstances that continue to occur will generate challenges for coastal ecology, one of which is a change in the sea-land boundary. It is possible to have an impact on the olive ridley turtles that rise to lay their eggs by changing the region of this coastal area, particularly at Trisik Beach, Kulonprogo, and Yogyakarta Special Region. The goal of this study was to use a Geographic Information System to estimate the effect of changes in the coastline on the distribution of olive ridley turtles on Trisik Beach, Kulon Progo, and Yogyakarta Special Region in 2020-2022. Digitizing the shoreline reveals changes in the coastline, which is then analyzed using Landsat 8 satellite data retrieved with ArcGIS software. The Landsat 8 photos span the years 2020-2022. Using the Digital Shoreline Analysis System (DSAS) toolbox, each image will go through area cropping or image cutting, geometric and radiometric correction, demarcation or development of a land-sea boundary line, on-screen digitalization, and automatic calculation of coastal changes. Trisik Beach's coastline alterations from 2020 to 2022 tended to create abrasion due to the shrinking beach area. The greatest average distance to a coastline alteration was -29.61 m, the smallest was -15.03 m, and the average speed of the greatest abrasion is -8.26 m/year, the smallest is -4.19 m/year, resulting in a 111,967.03 m2 reduction in coastal area. The association between shoreline alterations and the distribution of olive ridley turtle nesting on Trisik Beach is quite significant, with the beach area affecting 91.3% of turtle nests and 88.5% of turtle eggs.