Assessing the vulnerability of changing coasts, Hainan Island, China

Knowledge of coastline changes and vulnerability is of great importance to local government departments that are responsible for the management and development of coastal zones. To study the nature of change and vulnerability along the coasts of the Hainan Island, we collected a large number of sediment samples through the last few years, and reconstructed the changes of the coastline by combining the data of sediment grain-size analysis and the nautical charts/TM RS imaginary. Contrary to being almost free from erosion (as expected from the findings that the coastlines are in a relatively stable state), four major cities in Hainan (i.e., Haikou, Wenchang, Sanya and Changjiang) turned out to be suffered from a moderate coastal vulnerability primarily because of the large populations that impose considerable pressure on the coastlines. Thus, the assessment methodology utilized in this study, including both anthropogenic and natural factors, serves as a useful tool to obtain a comprehensive understanding of coastline vulnerability for local government, in terms of coastal management and adaptation.