Recent Extraction and Spatial Analysis of Yangtze River Estuary

Coastline Using Multi-Source Remote Sensing Data

Shiyu Liu

College of Resources and Environment, Northwest A&F University, Yangling District, Shaanxi Province, China

Keywords: Coastline Change, Yangtze River Estuary, Remote Sensing Analysis.

Abstract: Remote sensing technology and multi-source remote sensing data resources provide technical support for

monitoring coastline changes. This paper focuses on the dynamic evolution of the coastline in the Yangtze

River Estuary, which has a profound impact on the local marine-terrestrial ecological environment and

economic development.Based on multi-source remote sensing data from 1985 to 2020, this paper conducts a

detailed extraction and spatial analysis of the coastline characteristics in the Yangtze River Estuary, aiming

to reveal the long-term trends of coastline changes and their underlying influencing factors.After thorough

analysis, the coastline of the Yangtze River Estuary has shown a significant expansion trend over the past 35

years, which is related to factors such as river sediment transport, oceanic dynamic conditions, and human

activities. Comparative analysis further identifies the main regions and critical time nodes of coastline

changes.The research results provide a reference basis for the management and protection of the Yangtze

River Estuary coastline, and also offer methodologies and insights for similar studies in other regions, which

are significant for promoting the implementation of sustainable development strategies in coastal areas.

1 INTRODUCTION

The Yangtze River Estuary, located on the eastern

coast of China, serves as a crucial connection between

the interior and the ocean. The dynamic changes of its

coastline significantly affect the regional ecological

environment and economic development. In recent

years, the evolution of the Yangtze River Estuary

coastline has received increasing attention due to

multiple factors such as global climate change and

human activities. To scientifically and accurately

grasp the characteristics of coastline changes in this

critical region, this study conducts feature extraction

and spatial analysis of the Yangtze River Estuary

coastline based on multi-source remote sensing data

from recent years. By comprehensively applying

advanced remote sensing technology, this paper aims

to deeply reveal the evolution patterns of the

coastline, providing a scientific basis for ecological

protection, urban planning, and marine resource

management. It will also enhance understanding of

the dynamic changes of the Yangtze River Estuary

coastline and provide strong support for related

decision-making (Sümeyra Kurt et al., 2010). In

https://orcid.org/0009-0005-0245-2240

recent years, the evolution of the Yangtze River

Estuary coastline has attracted increasing attention

due to multiple factors such as global climate change

and human activities. Global climate change,

characterized by sea-level rise and frequent extreme

weather events, poses new challenges to coastline

stability and the ecological environment. Meanwhile,

rapid urbanization further changes the natural form

and ecosystem of the coastline. These changes not

only affect the lives and production of coastal

residents but also pose new requirements for regional

ecological environment, marine resource utilization,

and disaster prevention and mitigation.

To scientifically and accurately grasp the

characteristics of coastline changes in this critical

region, this study conducts feature extraction and

spatial analysis of the Yangtze River Estuary

coastline based on multi-source remote sensing data

from recent years. Remote sensing data, with its

advantages of wide coverage, strong timeliness, and

multi-scale and multi-spectral capabilities, provides

reliable data support for dynamic monitoring and

analysis of coastline changes. By integrating satellite

imagery, aerial imagery, and other high-resolution

Liu, S.

Recent Extraction and Spatial Analysis of Yangtze River Estuary Coastline Using Multi-Source Remote Sensing Data.

DOI: 10.5220/0013042900004601

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 1st International Conference on Innovations in Applied Mathematics, Physics and Astronomy (IAMPA 2024), pages 235-240

ISBN: 978-989-758-722-1

235

remote sensing data, this paper adopts advanced

remote sensing technology and Geographic

Information System (GIS) methods to accurately

extract the location and morphological characteristics

of the coastline (Kuifeng, 2019).

2 MATERIALS AND METHODS

2.1 Study Area

The Yangtze River, China's largest river, has a large

runoff and abundant sediment, forming a pattern of

three-level bifurcation and four outlets into the East

China Sea. The Yangtze River Estuary, the largest

estuary in China, has a complex estuary evolution

mechanism. For the study area, the coastline from

Lianxing Port in Jiangsu Province in the east to

Xuliujing in Jiangsu Province in the west is selected.

This area is a tidal estuary with high suspended

sediment concentration and complex bottom

sediment distribution. A large amount of sediment

from the upstream watershed is transported to this

area in various forms, making it a critical zone for

sediment deposition and the most active area for land-

sea interaction (Zhang & Song, 2023).

Figure 1. Map of the Study Area (Picture credit: Original)

2.2 Data Sources

The primary data sources for this study were obtained

from the Geo spatial Data Cloud

(http://www.gscloud.cn/). Specifically, Landsat

series remote sensing images were collected from

eight periods spanning from 1985 to 2020: 1985,

1990, 1995, 2000, 2005, 2010, 2015, and

2020.Among these, the images from 1985, 1990, and

1995 were captured by Landsat 4 -5 TM sensors,

while 2000 was recorded by Landsat ETM. Images

from 2005 and 2010 were captured by Landsat 7, and

2015 and 2020 by Landsat 8. These images were of

high quality, with cloud cover below 10%. In cases

where clouds were present, they were not located

along the coastline, thus having minimal impact on

coastline extraction. The preprocessing of these

images involved radiometric correction, atmospheric

correction, image registration, band composition,

image fusion, and projection conversion (Zhang &

Song, 2023).

2.3 Analytical Methods

In this study, the Modified Normalized Difference

Water Body Index (MNDWI) was utilized for the

initial extraction of the Yangtze River Estuary

coastline.MNDWI, an improvement upon the

Normalized Difference Water Body Index (NDWI)

(Guariglia et al., 2009), enhances the ability to

distinguish water bodies from soils and man-made

structures, thereby ensuring more accurate water

body extraction (Wei et al., 2023). The MNDWI is

calculated using the following formula:

MNDWI=GREEN-MIR/GREEN+MIR (1)

Where GREEN -- green band, and MIR -- middle

infrared band. In Landsat ETM and Landsat 8 images,

these correspond to bands 2 and 5, and bands 3 and 6,

respectively.

Despite the efficiency of MNDWI, manual visual

interpretation remains a high-precision method in

remote sensing interpretation. Therefore, the initially

extracted coastlines were refined through manual

visual interpretation, and the corrected coastline data

were overlaid with the processed remote sensing

images in ArcMap (White & Asmar, 1999). For

regions with unclear images or doubts, high-

resolution remote sensing images from Google Earth

at similar time periods were referred to ensure the

accuracy and completeness of the coastline

interpretation. Following data processing,

Geographic Information System (GIS) techniques

were employed to conduct spatial analysis on the

extracted coastlines, calculating parameters such as

area, perimeter, and shape indices to quantitatively

describe sediment deposition characteristics in the

Yangtze River Estuary.

Coastline Extraction Process:Coastlines featuring

rocky substrates in the intertidal zone typically

exhibit a distinct rocky structure and topographic

IAMPA 2024 - International Conference on Innovations in Applied Mathematics, Physics and Astronomy

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relief (Taveira-Pinto & Veloso-Gomes, 2009),

making their demarcation evident in remote sensing

images. In interpretation, the boundary between land

and sea water was considered as the coastline

(Alesheikh et al., 2007).

3 RESULTS

3.1 Shoreline Morphology and Feature

Extraction Results

Figure 2. Analysis of the Study Area Divided into Four

Regions (Picture credit: Original).

The Yangtze River Estuary coastline demonstrates a

pronounced expansion trend, particularly notable in

the eastern segments of Chongming Island, Pudong

New Area, and Nantong City . This phenomenon can

be attributed to various factors, including natural

processes (e.g., sedimentation, sea-level rise) and

human activities (e.g., land reclamation, port

construction).

Area-1: Southern Section of Haimen City

From 1985 to 2010, the shoreline length slightly

decreased (from 46.78 km to 46.59 km), indicating a

flattening trend. However, the area increased by

37.34 km² due to the construction of artificial

embankments. The curvature remained relatively

unchanged, and the shoreline direction was stable

with no significant turns.

Area-2: Eastern Section of Chongming Island

The shoreline length significantly increased (from

4 4.08 km to 59.57 km), averaging an advance of 2.83

km towards the sea, demonstrating a strong eastward

expansion. This was primarily driven by the artificial

construction of silt promotion dikes, which led to

coastal accretion. Although local curvatures might

exist due to the increase in shoreline length, the

overall direction remained eastward. The significant

seaward advancement of the coastline in this area

could be associated with large-scale land reclamation

projects aimed at expanding land area for urban

development and industrial expansion.

Area-3: Eastern Section of Pud ong New Area

The shoreline length slightly decreased (from

64.89 km to 64.34 km), while the area increased by

112.5 km², indicating a straightening effect through

land reclamation. Minimal changes in curvature and

a stable shoreline direction suggest significant human

intervention in this region. The notable coastline

expansion in Pudong New Area can be linked to rapid

urbanization, port development, and infrastructure

construction.

Area-4: Eastern Section of Nantong City

Anticipated changes in shoreline length and area

are likely due to urbanization and population growth,

potentially leading to a flattening of the shoreline

with a relatively stable direction. The significant

coastline changes in this area are associated with

economic development and population growth,

increasing the demand for land resources and,

subsequently, promoting artificial modification of the

coastline.

Figure 3. depicts the coastline changes from 1985 to 2020

(Picture credit: Original).

3.2 Analysis of Coastal Dynamics and

Evolution

Between 1985 and 2020, Area-1 (southern section of

Haimen City) experienced a coastal area growth of

approximately 11.7%, reaching 76.75 km ², and a

shoreline length increase of about 6.0%, or 5.81 km.

This growth is attributed to artificial embankments

and silt promotion projects, which stabilized the

coastline and increased land area. Meanwhile, Area-

2 (eastern section of Chongming Island) showed a

remarkable coastal area growth of about 62.5%,

reaching 196.1 km², and a shoreline length increase

of approximately 31.8%, or 17.56 km. This expansion

Recent Extraction and Spatial Analysis of Yangtze River Estuary Coastline Using Multi-Source Remote Sensing Data

237

is attributed to large-scale land reclamation and

natural sedimentation processes.

In contrast, Area-3 (eastern section of Pudong

New Area) exhibited a coastal area growth of about

12.6%, adding 81.07 km², but a decrease in shoreline

length of approximately 14.7%, or 11.67 km. This

change is associated with coastline straightening and

land reclamation activities, resulting in a shorter total

length. Area-4 (eastern section of Nantong City) also

saw a coastal area growth of about 35.3%, reaching

389.62 km², and a shoreline length increase of

approximately 11.3%, or 10.55 km. This growth is

linked to economic development and urbanization,

particularly in infrastructure and port development.

Both the eastern shoreline of Chongming Island and

the eastern shoreline of Pudong New Area display

significant siltation phenomena, primarily attributed

to the net movement of sediments at the Yangtze

River Estuary and the implementation of artificial

siltation promotion projects. The average annual

siltation of the Chongming Island shoreline is 6.11

km², while the eastern segment of Pudong New Area

experiences an average annual siltation of 4.69 km²,

indicating that these regions serve as primary sites for

sediment accumulation .

Both the eastern coast of Chongming Island and

the eastern coast of Nantong city experienced

significant expansion of their shorelines, mainly due

to land use changes caused by artificial reclamation

and urbanization. Although the length of the southern

coast of Haimen varies little, the increase in its area

also indicates a degree of expansion.

Figure 4. Statistics of Coastal Area by Zone (Picture credit:

Original).

Figure 5. Statistics of Shoreline Length by Zone (Picture

credit: Original).

Table 1. Statistics of Shoreline Length (1985-2020).

Year Total area/Km

Total Length/Km

1985 11749.83 800.86

1990 11739.50 771.22

1995 11921.56 821.68

2000 12683.43 837.33

2005 11533.47 845.68

2010 12532.14 859.23

2015 12787.96 872.70

2020 13423.08 932.34

Figure 6. Coastal Area Change (1985- 2020). (Picture

credit: Original).

Figure 7. Shoreline Length Change (1985-2020). (Picture

credit: Original).

3.3 Analysis of factors affecting

shoreline change

The changes in the Yangtze River Estuary's coastline

are primarily influenced by human activities,

especially construction projects and land use changes.

Land Reclamation: The southern shoreline of

Haimen City, the eastern shoreline of Chongming

Island, and the eastern shoreline of Pudong New Area

have all undergone land reclamation activities, which

have directly led to changes in shoreline length and

increases in regional area. Land reclamation has

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flattened the original natural shoreline, altering its

morphology. These land reclamation projects in the

region are primarily for industrial and commercial

development, aimed at expanding land area to meet

economic development needs. These projects have

not only altered the shoreline morphology but also

significantly impacted the local ecological

environment, such as destroying original wetlands

and habitats. The land reclamation projects in the

eastern part of Chongming Island are intended for

agricultural and urban construction, increasing

farmland and residential land through land

reclamation. These projects have altered sediment

deposition patterns , resulting in significant shoreline

changes.

Port Construction: Although the document does

not directly mention the impact of port construction

on the coastline, typically, port construction involves

large-scale shoreline modifications and dredging

projects, which significantly affect shoreline

morphology and ecological environments. The

construction and expansion of Shanghai Port involve

substantial land reclamation and shoreline

modifications. The development of port facilities

requires vast areas of land, replacing the original

natural shoreline with port terminals and breakwaters.

Dredging projects alter the natural sediment

deposition process, potentially intensifying erosion in

certain areas.

Artificial Siltation Promotion: The artificial

siltation promotion projects in the eastern shoreline of

Chongming Island and Pudong New Area have

accelerated sediment accumulation and shoreline

expansion, playing a crucial role in shaping the

coastline's evolution.

Urbanization: The changes in the eastern

shoreline of Pudong New Area and the assumed

similar trends in the eastern shoreline of Nantong City

are also influenced by urbanization. With population

growth and economic development, the demand for

land increases, driving land reclamation and shoreline

modification activities.

The changes in the Yangtze River Estuary's

coastline are the result of both natural and

anthropogenic factors, with human activities playing

a dominant role. Through the analysis of multi-source

remote sensing data, a clearer understanding of the

characteristics and evolution patterns of coastline

changes can be gained, providing a scientific basis for

coastal zone management and ecological protection.

4 CONCLUSIONS

This study delineates the intricate dynamics of

shoreline changes in the Yangtze River Estuary,

particularly focusing on the southern section of

Haimen City, the eastern sections of Chongming

Island and Pudong New Area, and the eastern section

of Nantong City. The period from 1985 to 2020

witnessed notable alterations in coastal areas and

shoreline lengths, predominantly influenced by

human interventions such as land reclamation, port

construction, and artificial siltation promotion,

alongside natural sedimentation processes.

The southern section of Haimen City and the eastern

shoreline of Chongming Island experienced

substantial growth in both coastal area and shoreline

length, driven by artificial interventions aimed at

stabilizing the coastline and increasing land area.

Conversely, the eastern shoreline of Pudong New

Area, despite a similar increase in coastal area,

exhibited a reduction in shoreline length, indicative

of the impact of coastline straightening and land

reclamation activities.

Significant siltation phenomena were observed

along the eastern shorelines of Chongming Island and

Pudong New Area, primarily due to the net movement

of sediments at the Yangtze River Estuary and

artificial siltation promotion projects. The eastern

coast of Nantong City also demonstrated considerable

shoreline expansion, largely due to economic

development and urbanization, particularly in

infrastructure and port development.

The study underscores the dominant role of

human activities in shaping the coastline of the

Yangtze River Estuary, with land reclamation

projects flattening natural shorelines and altering

sediment deposition patterns. Port construction and

artificial siltation promotion have accelerated

sediment accumulation and shoreline expansion,

significantly impacting shoreline morphology and

ecological environments.

The analysis of multi-source remote sensing data

has provided a clearer understanding of the

characteristics and evolution patterns of coastline

changes, offering a scientific basis for coastal zone

management and ecological protection. This study

captures the cumulative effect of underlying dynamic

processes, utilizing remote sensing and GIS

techniques to model shoreline changes and reduce

uncertainty associated with hydrodynamic

parameters.

The findings contribute to a comprehensive

understanding of the evolution of the entire delta,

highlighting the potential of remote sensing and GIS

Recent Extraction and Spatial Analysis of Yangtze River Estuary Coastline Using Multi-Source Remote Sensing Data

239

techniques for facilitating detailed and in-depth

assessments of shoreline changes. The methodology

employed in this study is considered valuable for

evolution studies of other large global delta systems,

providing a template for future research and policy-

making in coastal management and ecological

conservation.

REFERENCES

S ü meyra Kurt, Karaburun, A., & Demirci, A. (2010).

Coastline changes in Istanbul between 1987 and 2007.

Scientific Research and Essays, 5(19), 3009-3017.

Kuifeng, W. (2019). Evolution of Yellow River Delta

coastline based on remote sensing from 1976 to 2014,

China. Chinese Geographical Science, 29(2), 11.

Zhang, D., & Song, L. (2023). Analysis of tidal flat

evolution in the Yangtze River Estuary from 2002 to

2019. Port & Waterway Engineering, 2023(6), 137-

143.

Nourdi, N. F., Onguéné Raphael, Abessolo O. Grégoire,

Rudant, J. P., & Minette, T. E. (2021). Seasonal to

decadal scale shoreline changes along the Cameroonian

coastline, Bay of Bonny (1986 to 2020). Regional

Studies in Marine Science, 45, 101798.

Guariglia, A., Buonamassa, A., Losurdo, A., Saladino, R.,

& Colangelo, A. (2009). A multisource approach for

coastline mapping and identification of shoreline

changes. Annals of Geophysics, 49(1).

Wei, S., Fu, D., Liu, D., Xu, H., Li, G., & Cheng, Y. (2023).

Remote sensing monitoring of Shenzhen coastline

changes over 40 years of reform and opening up.

Tropical Geography, 43(5), 986-1004.

White, K., & Asmar, H. M. E. (1999). Monitoring changing

position of coastlines using thematic mapper imagery:

An example from the Nile Delta. International Journal

of Remote Sensing, 29(1-2), 0-105.

Taveira-Pinto, F., & Veloso-Gomes, P. B. (2009). Coastline

evolution at Esmoriz-Furadouro stretch (Portugal).

Journal of Coastal Research, Special Issue No. 56, 673-

677.

Alesheikh, A. A., Ghorbanali, A., & Nouri, N. (2007).

Coastline change detection using remote sensing.

International Journal of Environmental Science and

Technology, 4(1), 61-66.

Meyer, M., Harff, J., Gogina, M., & Barthel, A. (2008).

Coastline changes of the Darss–Zingst Peninsula — a

modelling approach. Journal of Marine Systems,

74(Supplement S), S147-S154.

IAMPA 2024 - International Conference on Innovations in Applied Mathematics, Physics and Astronomy

240