Analysis on the Dynamics of Coastline and Reclamation in Pearl River Estuary in China for Nearly Last Half Century

Abstract

The Pearl River Estuary is in the geometric center of Guangdong-Hong Kong-Macao Greater Bay Area, which is one of the main battlefields to drive the high-quality development of China’s economy. This paper uses seven sets of typical satellite images in Pearl River Estuary for nearly half a century (from 1973 to 2021) to analyze the changes of coastline and sea reclamation. The results show that from 1973 to 2021, the total length of the coastline of the Pearl River Estuary increased from 240.09 km to 416.00 km, and that of the continental coastline from 186.87 km to 246.21 km (but the length of natural coastline in the continental coastline decreased from 136.91 km to 15.17 km). In the same period, the total reclamation area of the Pearl River Estuary increased by 28,256.06 ha. Before 2012, the growth rate of reclamation was generally fast. After 2012, the reclamation in China has entered a period of reflection. With reclamation was strictly controlled in the new era, only the previously approved reclamation projects and national major projects have been guaranteed, which makes the average annual growth rate of the coastline length and the reclamation area in the region show a significant downward trend. The reclamation in early days was largely for agriculture and pond culture purposes, but is shifting to transportation, industrial development, and urban construction in recent decades. This study scientifically analyzes the coastline and reclamation changes of the Pearl River Estuary in the past half century, which has a very important reference value for the next step to formulate marine ecological protection and restoration strategies, and construct a new pattern of marine space development and protection.

Millennial-scale societal shifts drive the widespread loss of a marine ecosystem

“…The PRD has experienced continuous shoreline advances from land reclamation since 200 CE, with almost the entire PRD shoreline, tidal current regime and sediment load being modified throughout the centuries until the present day (Xiong et al, 2020). Since 1973, 89% of the natural PRD coastline has been modified through modern land reclamation (Zhang et al, 2022), and the habitats where native oyster reefs would have existed and benefited the PRD’s society for the last millennium no longer exist. Historical observations pinpointed natural oyster reefs throughout the PRD until the early 1900s.…”

“…Wang et al, 2021; Wu & Richards, 1981; Zeng et al, 2012) obtained throughout the PRD, as well as the known extent of coastline reclamation (Wei et al, 2021; X. Zhang et al, 2022), indicate that there is unlikely any remaining physical evidence of natural oyster reefs in the region. Therefore, we systematically reviewed the scientific literature and historical documents to evaluate the historical existence of oyster reefs.…”

Asymmetric evolution of river mouth bifurcation under angled river‐tide interaction, a case study at river mouths of Lingding Bay, Pearl River estuary

“…These human effects on channel evolution are less significant than those on land reclamation activities. Recently, the government restricted land reclamation activities (Zhang et al, 2022). Since the 2010s, an increase in tidal range has been observed at the river mouths of Lingding Bay (Wei, Cai, & Zhan, 2021; Yang et al, 2019).…”

“…These human effects on channel evolution are less significant than those on land reclamation activities. Recently, the government restricted land reclamation activities (Zhang et al, 2022).…”

Land Subsidence in a Coastal City Based on SBAS-InSAR Monitoring: A Case Study of Zhuhai, China

“…In Zhuhai, owing to the influence of sea retreats and sea intrusions in the historical period, there are Quaternary deposits mainly in marine and coastal phases distributed in a large area [49]. Coupled with the large scale of land reclamation, soft soils consisting of silt, silty soil, and soft clay are widely distributed in the area [50]. In this study, the soft soil of the Zhuhai stratum was analyzed, and six soft soil thickness levels of <5 m, 5~10 m, 10~20 m, 20~30 m, 30~40 m, and >40 m were set.…”