Evolution of the topography of tidal flats and sandbanks along the Jiangsu coast from 1973 to 2016 observed from satellites

Wang, Yongxing; Liu, Yongchao; Jin, Song; Sun, Chao; Wei, Xianglin

doi:10.1016/j.isprsjprs.2019.02.001

Cited by 59 publications

(30 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Historical records of tides indicate that the average rate of sea level rise along the the Radial Sand Ridge is about 5.26 mm/year, which is about twice the global average (2.43 mm/year) [ 57 ]. In the next 30 years, the average sea level along the Radial Sand Ridge will rise by about 85–150 mm [ 28 ]. This rise will lead to a decrease in the area of the tidal flat exposed at the lowest tide in the Dongsha Shoal, the expansion of the erosion area, and the ridge line of the sand will become unstable.…”

Section: Discussionmentioning

confidence: 99%

“…However, due to the high cost of LiDAR-based data and aerial images, it is difficult to perform time series analysis on tidal flats [ 25 , 26 ]. Since the launch of the Landsat-1 satellite in 1972, many satellite images of research value have been archived [ 27 , 28 ]. As more Earth exploration satellites were launched, and other satellite data cooperation projects, the potential of intensive time series analysis has been greatly expanded, especially in tidal flats [ 29 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Recent Evolution of the Intertidal Sand Ridge Lines of the Dongsha Shoal in the Modern Radial Sand Ridges, East China

Liu

Zhang

et al. 2021

IJERPH

View full text Add to dashboard Cite

The Dongsha Shoal is one of the largest shoals in the South Yellow Sea and has important marine ecological value. The shoal extends in a south–north direction and is controlled by the regional dominating tidal currents. Recently, due to human activities and some natural factors, the geomorphic dynamics of the Dongsha Shoal has undergone drastic changes. However, few people have proposed quantitative research on the changes of tidal flat morphology, let alone the long-term sequence analysis of sand ridge lines. Hence, we attempt to take the Dongsha Shoal in the Radial Sand Ridges as the research area, and analyze the trends of the long-term morphological evolution of the sand ridge lines over the period 1973–2016 based on a high-density time series of medium-resolution satellite images. The sand ridge line generally moves from southeast to northwest, and the position distribution of the sand ridge line from north to south has gradually changed from compact to scattered. We also found that the geomorphological dynamics at different positions of the sand ridge line are inconsistent. The north and south wings are eroded on the west side, while the central area is eroded on the east side. Most of the sand ridge line is moving eastward. In addition, the change of sand ridge line is affected by multiple factors such as sediment supply, typhoon, reclamation and laver cultivation.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Recent Evolution of the Intertidal Sand Ridge Lines of the Dongsha Shoal in the Modern Radial Sand Ridges, East China

Liu

Zhang

et al. 2021

IJERPH

View full text Add to dashboard Cite

show abstract

“…The Subei Sandbanks is the intertidal zone of the Radial Sand Ridges along the Jiangsu coast in the Southern Yellow Sea (Figure 1a). It is also the largest tidal flats in China, covering an area of approximately 2300 km 2 owing to the active tidal processes and abundant sediment supply (Wang et al., 2019). The vast amount of sediment brought by terrestrial runoff also leads to poor visibility of seawaters, resulting in the limited ability of optical remote sensing technique to detect underwater topography in this area (Figure 1b).…”

Section: Study Area and Data Setsmentioning

confidence: 99%

Automatic Waterline Extraction and Topographic Mapping of Tidal Flats From SAR Images Based on Deep Learning

Zhang

Wang

et al. 2022

Geophysical Research Letters

View full text Add to dashboard Cite

This study presented an intuitive approach to derive large‐scale tidal flat's Digital Elevation Model (DEM). We first developed an automated method for accurately extracting the waterline from Synthetic Aperture Radar images acquired in Subei Sandbanks along the Yellow Sea coast of China between 2015 and 2020 based on deep convolutional neural networks. The statistical results show this method has appreciable accuracy for efficient waterline extraction even under complex imaging conditions with a mean recall and precision of 0.90 and 0.80, respectively. Then the pixel‐level extracted waterlines are calibrated with a global tide model to construct the large‐scale tidal flat's DEM in the study region. The comparison against in situ topographic data shows an error of 29 cm, demonstrating the usefulness of monitoring the morpho‐sedimentary evolution in intertidal areas. Furthermore, the Subei Sandbanks remained stable from 2015 to 2020, while the coastal region changed drastically due to human activities.

show abstract

“…Measurements were conducted in the shallow nearshore of the central Jiangsu coast (Figure 1a), where broad intertidal flats extend for 2-6 km and have a mean gradient of only 0.05-0.1% (Zhang, 1992;Zhang et al, 2004;Wang et al, 2012). At the outer edge of the tidal flats, there is a wide, deep and shore-parallel tidal channel named the Xiyang Creek that has a maximum depth of about 34 m. Bank erosion is observed along Xiyang Creek at present (Gong et al, 2011;Wang et al, 2019). Controlled by a unique radial tidal current field in the offshore area (Zhang et al, 1999), the near-shore tidal wave is characterized by high current velocity and relatively large tidal range (average value of 3.68 m).…”

Section: Regional Settingmentioning

confidence: 99%

The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats

et al. 2021

View full text Add to dashboard Cite

Periods of very shallow water (water depth in the order of 10 cm) occur daily on tidal flats because of the propagation of tides over very gently sloping beds, leading to distinct morphodynamical phenomena. To improve the understanding of the characteristics of velocity and suspended sediment concentration (SSC) surges and their contribution to sediment transport and local bed changes during periods of very shallow water, measurements of near-bed flow, and SSC were carried out at two cross-shore locations on an intertidal flat along the Jiangsu coast, China. Furthermore, the role of surges in local resuspension and morphological change was explored. Results indicate that flow and SSC surges occurred at both stations during very shallow water periods. On the lower intertidal flat, flood surges were erosive, while weaker surges on the middle intertidal flat were not. Surges on lower intertidal flats resulted in local resuspension and strong turbidity, contributing up to 25% of the onshore-suspended sediment flux during flood tides, even though they last only 10% of the flood duration. When surges travel across the flats, conditions change from erosional to depositional. Velocity surges on the middle intertidal flat were too weak to resuspend bed sediment, and the associated SSC surges were produced by advection.

show abstract

Evolution of the topography of tidal flats and sandbanks along the Jiangsu coast from 1973 to 2016 observed from satellites

Cited by 59 publications

References 61 publications

Recent Evolution of the Intertidal Sand Ridge Lines of the Dongsha Shoal in the Modern Radial Sand Ridges, East China

Recent Evolution of the Intertidal Sand Ridge Lines of the Dongsha Shoal in the Modern Radial Sand Ridges, East China

Automatic Waterline Extraction and Topographic Mapping of Tidal Flats From SAR Images Based on Deep Learning

The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats

Contact Info

Product

Resources

About