Recent morphological changes of the mouth bar in the Modaomen Estuary of the Pearl River Delta: Causes and environmental implications
2019
Tan, Chao | Huang, Bensheng | Liu, Feng | Huang, Guangling | Qiu, Jing | Chen, Hui | Liu, Da | Xie, Rongyao
The Pearl River Delta (PRD) is one of the most economically important and urbanized deltas in Asia. The Modaomen Estuary, being the most important passage of water and sediment through the PRD into the sea, was regulated by estuarine reclamation since the mid-1980s. After the completion of regulation projects in the 1990s, it was transformed from a shallow bay into a series of regulated channels. As a result, the evolution of the mouth bar of the Modaomen Estuary, a key morphological unit determining delta formation, has been altered. In this study, we examine morphological responses of the mouth bar of the Modaomen Estuary to human activities and natural factors (i.e., riverine flood) from 1994 to 2010. As an effect of the estuarine extension towards the sea caused by the regulation projects, the mouth bar has gradually moved towards the sea. From 1994 to 2010, for instance, the west and east branches extended more than 2.1 km further seawards. In addition, flood scouring played an important role in the bar extension and the formation of secondary branches at the mouth bar. Furthermore, the front of the mouth bar was eroded by wave dynamics because of reductions in the sediment load from the Pearl River. In general, the mouth bar deflected southwestward after 1994, indicating an evolution of the sediment sink at the Modaomen estuary in the same direction. Our studies contribute to better understanding of the evolution of large estuaries and provide scientific guidelines for the sustainable management of the PRD.
显示更多 [+] 显示较少 [-]