Sea-Level Rise on Eastern China's Yangtze Delta
Keywords:Delta flooding, Neolithic sites, peat, radiocarbon dates, relative sea level, sea-level curve, subsidence, Taihu lake, Yangtze delta
The Yangtze delta is a densely populated, low-lying region highly vulnerable to flooding, high tides and typhoons. All previous studies indicated that relative sea level was higher from ~7500-4000 yrs. BP, then lowered and stabilized at about present msl during the past 3000 yrs. To the contrary, we find that sea level has been rising relative to the southern Yangtze delta plain based on new sea-level data derived from dated peats, reassessment of earlier sea-level curves and measurement of delta plain subsidence and analysis of prehistoric habitat bases from ~7000 to 3000 yrs. BP. Consequences of this relative rise include difficulty in expelling water from the low-lying delta plain to the coast and associated flood damage. Emplacement of the 3-Gorges Dam on the Yangtze will control flooding of the Yangtze river but decrease sediment accumulation on the delta plain that, in turn, is likely to accelerate saline inundation of this vital breadbasket.