Remote Sensing of the Coastline Variation of the Guangdong–Hongkong–Macao Greater Bay Area in the Past Four Decades

Jing Yu,Lijun Yao,Dongliang Wang,Pimao Chen,Ruirui Hu

doi:10.3390/jmse9121318

Abstract

In this study, a combination of example-based feature extraction and visual interpretation was applied to analyze the coastline variations in the Guangdong–Hong Kong–Macao Greater Bay Area (GHMGBA) from the past four decades based on the Landsat satellite remote sensing image data from 1987–2018, using ENVI and ArcGIS software. The results showed that the total length of the coastline of the GHMGBA increased in the past four decades, rising from 1291 km in 1987 to 1411 km in 2018. Among these, artificial coastline increased by 450 km, while the other coastline types decreased. The type of coastline that decreased the most was bedrock coastline, by a total of 172 km. The silty coastline disappeared, and almost all of it was converted to artificial coastline. Variations in the coastline of the GHMGBA were mainly connected to human activities and showed an overall trend of advancing towards the ocean. Dynamic monitoring of coastline variations can provide a reference for the protection of natural resources, sustainable marine development and rational planning of the coastal zone.

Highlights

A coastline is the boundary line between land and sea, located in the sensitive transition zone extending from both regions [1] and refers to the boundary reached by high tide [2]
The major outcome of these procedures reveals that the coastline of the Guangdong–Hong Kong–Macao Greater Bay Area (GHMGBA) has increased by 120 km in the past four decades, with an overall variation rate of 0.3%
We combined feature extraction and visual interpretation to extract coastline data, so we could make corrections based on the automatic extraction of an object-oriented coastline

Summary

Introduction

A coastline is the boundary line between land and sea, located in the sensitive transition zone extending from both regions [1] and refers to the boundary reached by high tide [2]. It is an area where human activities are more concentrated and resources and environmental conflicts are the most prominent [3]. The changes on coastlines are the result of the interaction between human activities and natural factors, reflecting the mutual influence among economy, society and ecology. The study of coastline variation plays an important role in the natural resources and ecological protection of the coastal zone. For a larger area, such as the Guangdong–Hong Kong–Macao Greater Bay Area (GHMGBA), which includes the PRE, the coastline variability at a longer time scale (nearly four decades) remains unclear

Results

Discussion

Conclusion