Author(s): Wei Chen; Cuiping Kuang; Jie Gu; Xiaodan Mao
Linked Author(s): Cuiping Kuang
Keywords: SLR; Changjiang River estuary; Numerical simulation; Flood season
Abstract: Viewing from the global scope, the climate change has triggered many unfriendly environmental phenomena, such as temperature rise, glaciers melting, sea level rise (SLR) and so on. The 4th IPCC report highlights that the average global SLR rate is 1. 8 mm/y since 1963. According to the statistical description of China Sea Level Bulletin, between 1980 and 2011, the average rise rate of sea level is 2. 7 mm/y in the coastal areas of China, which is much greater than that of global. Under the background of climatic variation, there is no doubt that coastal areas are fronted with long-term impacts and threats due to SLR. In this paper, the Changjiang River Estuary is chosen as a prototype to preliminary study the responses of the estuary to potential future SLR, and the MIKE21 is selected as a tool to establish the depth-averaged hydrodynamic model of the Changjiang River Estuary. This model has been validated with the measured data, and the computed results of tidal levels, velocity magnitudes and directions match very well with the measured data, after that the validated model is run for present sea level as well as 0. 5, 1 and 2 m SLR scenarios in the flood season respectively. The computed results indicate that: i) the increased values of high tidal levels in channels respond to SLR are slightly smaller than SLR value; ii) the peak flood and ebb velocities perform in a spatially non-uniformity manner, with the peak flood velocities increasing in the South Branch and the South Channel and deceasing in the lower reaches of the North Branch and the North Channel, while the peak ebb velocities increase in the North Branch, the South Branch and the North Channel, and decrease in the lower reaches of the North Channel, the North Passage and the South Passage; iii) a large quantity of ebb flow crosses over the shoals, especially the Chongming Eastern Shoal and the Jiuduansha Shoal. Hence, SLR presents important impacts on the evolution of river regime in the Changjiang River Estuary.
Year: 2013