Search

Owing to the development of the social economy, the geographical environment and ocean utilization patterns of urban coastal zones have changed. This change, in turn, has influenced the socio-economic development of urban coastal zones. Based on the Geographic Information System technology, the area, coastline length, and shoreland use function of reclamation areas were obtained from the geographic charts (1954–2020) and remote sensing data (1988–2017) of Quanzhou Bay. In this study, we analyzed the geomorphologic change process and the relationship between land use patterns and economic development in Quanzhou Bay from the perspectives of hydrodynamics, sediments, and human activity. Our results indicated that over the past 70 years, the bay area has reduced by 21.5%. The length of the coastline decreased from 208.36 km in 1959 to 149.11 km in 1988, whereas the shape index of the bay (SIB) decreased from 3.09 to 2.41 during the same period. Between 1988 and 2017, the coastline increased to 162.91 km, causing the SIB to increase to 2.72. The artificial index of the bay increased from 0.28 in 1959 to 0.90 in 2017. The intensity of bay the development (IBD) first increased from 0.27 in 1959 to 0.77 in 2006. During the transition to a more modern society (2006 to present), the IBD slightly decreased to 0.73 in 2017. Affected by human activity, the transformation of the reclaimed land in Quanzhou Bay can be divided into four stages that are closely linked to the economic development in the region. In the early industrialization period, reclaimed land in the region was used for agricultural production, whereas in the mid-industrialization period, it was gradually transformed into a combination of industrial (29.8%) and agricultural (56.1%) lands. In the later period of industrialization, the reclaimed land was gradually converted into urban industrial and port lands. Finally, with further refinement and upgrading of economic and industrial structures, the socio-economic and environmental benefits from coastal reclamation projects have been increasing, whereas the proportion of economic benefits (in the total benefits) has been decreasing. The results of this study can provide decision-making references for the optimization of utilization patterns and the economic development of reclamation lands in coastal areas.

With the development of social economy and human activities, the geomorphology and hydrodynamic conditions of coasts have been dramatically changed, causing serious environmental pollution and resource depletion. Taking Quanzhou Bay as an example, this study combined geomorphologic change with a hydrodynamic model to simulate the change in tidal currents in different periods. The results show a change in the coastline was the main cause of hydrodynamic change during the industrialization reform. During the past 70 years, the tidal prism decreased year by year, and the average velocity of the tidal current in the channel decreased by 33.7% and 30.8% at flood and ebb tide, respectively. In the early stages of industrialization, reclamation land was used in a single way. The tidal prism decreased by 22.2% and 29.8% in the spring and neap tide, respectively. In the middle and later stages, the tidal current velocity increased, and reclamation land was used in a variety of ways. In modern society, the reclamation land-use type was unitary. Based on this research, we show the influence of human activities on the evolution of the bay’s geomorphology and provide suggestions for the management of the bay.

Typhoons play a significant role in the marine sedimentary dynamic process and thus could significantly change the submarine geomorphology in their influence area. In this study, a high-resolution sub-bottom profiler and a side-scan sonar were used to detect the submarine geomorphology of the southeast coastal area of Nanri Island in the Taiwan Strait before and after Typhoon Soudelor—three times in 2015. The results show that the typhoon induced seaward movement of the sand dunes up to several tens of meters, resulting in significant changes in both the shape of the sand dunes and the scale of the exposed bedrocks. The typhoon also changed the submarine geomorphology, including the smoothing of anchor traces of fishing boats and the formation of relatively small sand dunes (groups). A comparison of the results of different surveys shows that the submarine geomorphology that was changed by Typhoon Soudelor could not recover within a short period of time. The wind field simulations of the typhoon process showed that the storm wave caused by the strong wind stress of the typhoon was a key dynamic factor for changing the submarine geomorphology.