Analysis of Shoreline Changes and Erosion and Sedimentation Patterns in Boujagh National Park Using Landsat Satellite Imagery Payam ALEMI SAFAVAL a , Zahra AZIZI b,1 , Alexandros STEFANAKIS c , S. Ahmad NESHAEI d , Masoud KHEIRKHAH ZARKESH e and Salar MIRZAPOUR f a Remote Sensing and GIS, Geological Survey & Mineral Exploration of Iran, Iran b Department of Remote Sensing and GIS, Science and Research Branch, Islamic Azad University, Tehran, Iran c Laboratory of Environmental Engineering and Management, School of Chemical and Environmental Engineering, Technical University of Crete, 73100 Chania, Greece d Department of Civil Engineering, University of Guilan, Rasht, Iran e Associate Professor of Soil Conservation and Watershed Management Research Institute, AREEO, Iran f Department of Remote Sensing and GIS, Science and Research Branch, Islamic Azad University, Tehran, Iran Abstract. Boujagh National Park, situated on the southern coast of the Caspian Sea, is the first National marine-land park in Iran. The Park encompasses a delta formed at the mouth of the Sefidroud River and includes two significant wetlands: Kiashehr International Lagoon, a Ramsar Convention registered site, on the east side, and Boujagh Wetland on the west side. The continuous interaction between marine and terrestrial forces significantly impacts this crucial ecosystem. This study aims to investigate the morphological changes along the coastline and estimate erosion and sedimentation within the sand belt of Boujagh National Park. The methodology employed involves utilizing unsupervised classification algorithms on Landsat satellite images from 2001 and 2019. Following unsupervised classification, the beach class was identified, and a comparison was made between two distinct beaches by drawing 81 transects. Subsequently, by connecting these two beaches from 2001 to 2019, eroded and sedimented areas were determined. The findings reveal that the central part of the delta experienced erosion with an area of 72.6 hectares at its head, while both sides of the delta encountered sedimentation spanning from west to east with areas measuring 85.67 hectares and 128.92 hectares respectively. Keywords. Boujagh National Park, shoreline changes, erosion, sedimentation patterns, satellite imagery 1 Zahra AZIZI, Corresponding author, Department of Remote Sensing and GIS, Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, IRAN; E-mail: zazizi@srbiau.ac.ir. Hydraulic and Civil Engineering Technology VIII M. Yang et al. (Eds.) © 2023 The Authors. This article is published online with Open Access by IOS Press and distributed under the terms of the Creative Commons Attribution Non-Commercial License 4.0 (CC BY-NC 4.0). doi:10.3233/ATDE230886 1478