Geospatial Analysis of Shoreline Change in Bolok and Nitneo Villages, Kupang Regency

Abstract

Shoreline change is an important environmental indicator as it reflects the dynamics of natural processes and human-induced pressures. This study aims to analyze the spatial-temporal dynamics of shoreline changes in Bolok and Nitneo Villages, Kupang Barat Subdistrict, East Nusa Tenggara Province, Indonesia, over the period from 2002 to 2025. The method employed is a descriptive-quantitative geospatial approach utilizing multi-temporal Landsat satellite imagery processed through Geographic Information System (GIS) techniques. Shorelines were manually digitized and analyzed using transects constructed along a georeferenced baseline. Parameters calculated include Net Shoreline Movement (NSM) and End Point Rate (EPR) to depict the direction and rate of shoreline change. The results show that 64.2% of the 232 transects experienced accretion, indicated by positive NSM and EPR values, predominantly in the western and central segments of the coastline. In contrast, areas around Bolok Port and the adjacent industrial zones experienced erosion, with the highest retreat rate reaching −0.97 m/year. These spatial patterns correlate with intensified land use, infrastructure development, and the natural dynamics of coastal sedimentation. The findings are consistent with previous studies in the Waingapu, Sabu Raijua, and Teluk Kupang regions, which demonstrate the interaction between coastal morphology, wave energy, and anthropogenic activities. This research demonstrates the effectiveness of integrating geospatial technology in long-term shoreline monitoring and supports the adaptation of coastal zoning policies under the RZWP3K framework. It is recommended that erosion-prone zones be prioritized for disaster mitigation, while accretion zones may be directed toward sustainable coastal development. Further studies are encouraged to incorporate high-resolution validation and additional physical parameters.