Influence of sea level rise on Shanghai astronomical tide and storm surge and estimation of probable water level

Abstract

A nonlinear two-dimension dynamic model of storm surge (SS) and astronomical tide (AT) was used to investigate the effects of SS and AT on expected sea level rise (SLR) at principal coastal stations in the Shanghai region and to estimate numerically the probable maximum water level for 2010–2050. Evidence suggests that SLR causes reduction of SS; that its influence on SS depends on the intensity and path of a tropical cyclone and the station locality; that the SLR's effects on AT vary periodically, with the period being the same as that of the AT's; and that as the SLR increment grows, its impact increases; below mean sea level (MSL) the effect is positive at rising tide and negative at ebb tide, and vice versa for the effect above MSL. Study of the probable maximum water level (by assuming SLR, SS along favorable tropical cyclone's path, its possible maximum intensity and effective spring AT at a range of set paths of Cyclones 5612, 8114, 9417) showed that the probable maximum water level is 740, 745, and 751 cm in the years 2010, 2030, and 2050, respectively, over the target region.