Population and economic risk exposure in coastal region of China under sea level rise

Based on the Global Tide and Surge Reanalysis (GTSR) dataset, the relevant Digital Elevation Model (DEM) was imported into ArcGIS and spatial analysis tools were used to extract possible flooding ranges due to sea level rise in 11 provinces and cities of coastal China. Combined with population, economic, and land use data, a sea level rise risk exposure assessment model is constructed and the population and economic risk exposure from sea level rise in coastal region of China are assessed. Three primary conclusions are drawn from the evaluation: (1) The impact of sea level rise on the coast areas is mainly concentrated in the Yangtze River Delta and northern Jiangsu coastal plains, as well as the Pearl River Delta and Bohai Rim, and other coastal plain areas. The most seriously affected land use types are arable land, which accounts for 65% of affected areas, followed by construction land; (2) Based on population and economic statistics from 2015 and 10 to 1000 years return periods, sea level rise increases risks to populations and the aggregated economy. In terms of sea level rise risk exposure, Guangzhou is most exposed and other areas with high exposure are concentrated in the Yangtze River Delta, northern Jiangsu coastal plains, the Pearl River Delta and Bohai Rim Region; (3) Based on population and economic statistics estimated using five shared social economic paths (SSPs), and variations in return periods from 10 to 1000 years, the gross population and the aggregated economies for 2025 and 2100 tended to increase in different paths. The conventional development path (SSP5) resulted in the largest affected population and aggregated economy while the local or inconsistent development path (SSP3) and unbalanced development path (SSP4) resulted in lower impacts than those of the other three paths. Changes in the return period from 10 to 1000 years can shift the risk exposure. Comparing the exposure risk to the population and economies, we found that the exposure degree in 2100 will be lower than that in 2025. © 2019, Science Press. All right reserved.