Dynamic process and artificial mechanism of coastline change in the Pearl River Estuary

Abstract

The Pearl River Estuary (PRE) is a window into the drastic changes that occurred throughout coastal areas due to artificial agglomeration following China’s 1978 economic reform. In this study, multi-temporal Landsat remote sensing images were used to extract coastlines in the PRE with the support vector machine (SVM). In addition, the coastline was divided into nine segments by using the eight mouths as the cut-off points. A statistical analysis was performed on the length and changes of each coastline segment. The analysis was focused on the five shores that exhibited obvious changes. Subsequently, a correlation analysis between three artificial development factors, namely, the development intensity, development speed, and development density, and the shoreline length was conducted, following which the main driving factors influencing the changes in the coastline were obtained. Finally, the dynamic processes and artificial mechanisms of the coastline changes in the PRE were deeply analyzed. The results reveal that the coastline has been gradually advancing over a distance of 164.01 km toward the sea over the past 40 years, and the growth rate initially showed a rapidly increasing trend in 1978 but has since slowed from 1998 to the present. The most significant changes were detected along the Hutiao Men–Jiti Men and Jiti Men–Modao Men shore areas due to the impacts of human activities. The development speed presented dominant influence on coastline change at the end of the 20th century, but the development intensity was the primary influence factor during the early 21st century. To a certain extent, the monitoring and analysis of historical coastline changes can contribute to coastal zone planning in more detail, thereby promoting the sustainable development of coastal zones.