Prediction and prevention of the impacts of sea level rise on the Yangtze River Delta and its adjacent areas

The Yangtze River Delta region is characterized by high density of populati on and rapidly developing economy. There are low lying coastal plain and de ltaic plain in this region. Thus, the study area could be highly vulnerable to accelerated sea level rise caused by global warming. This paper deals w ith the scenarios of the relative sea level rise in the early half period o f the 21st century in the study area. The authors suggested that relative s ea level would rise 25-50 cm by the year 2050 in the study area, of which t he magnitude of relative sea level rise in the Yangtze River Delta would do uble the perspective worldwide average. The impacts of sea level rise inclu de: (i) exacerbation of coastline recession in several sections and vertica l erosion of tidal flat, and increase in length of eroding coastline; (ii) decrease in area of tidal flat and coastal wetland due to erosion and inund ation; (iii) increase in frequency and intensity of storm surge, which woul d threaten the coastal protection works; (iv) reduction of drainage capacit y due to backwater effect in the Lixiahe lowland and the eastern lowland of Taihu Lake region, and exacerbation of flood and waterlogging disasters; a nd (v) increase in salt water intrusion into the Yangtze Estuary. Comprehen sive evaluation of sea level rise impacts shows that the Yangtze River Delt a and eastern lowland of Taihu Lake region, especially Shanghai Municipalit y, belong in the district in the extreme risk category and the next is the northern bank of Hangzhou Bay, the third is the abandoned Yellow River delt a, and the district at low risk includes the central part of north Jiangsu coastal plain and Lixiahe lowland.