Present surface elevation change and trend in Tianjin and its coastal area.

Comparative study of topographical maps and data produced in different periods in the last century illustrates that great changes in surface elevations have taken place in Tianjin and its coastal area in nearly one hundred years in the 20th century. Based on four essential parameters of the surface morphology influencing the coastal area-remaining elevation, ground subsidence, sea-level rise and vertical accretion rates, this study predicts that the surface elevation of Tianjin and its coastal lowland will continue to be reduced in 2030. With the concomitant influence of the attendant sea-level rise,envisaged paludification will press on towards the Tianjin metropolitan center in the coming years.