Acta Geographica Sinica ›› 2014, Vol. 69 ›› Issue (10): 1510-1520.doi: 10.11821/dlxb201410010

• Orginal Article • Previous Articles     Next Articles

Research on accessibility model of Nansha Islands and surrounding seaports

Wei SHI1,2,3(), Fenzhen SU1,3(), Chenghu ZHOU1,3, Wenzhou WU1,3   

  1. 1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. Collaborative Innovation Center of South China Sea Studies, Nanjing 210093, China
  • Received:2013-10-06 Revised:2014-05-20 Online:2014-10-20 Published:2014-10-20
  • Supported by:
    The National Natural Science Foundation of China, No.41271409;National High Technology Research and Development Program of China, No.2012AA12A406


Nansha Islands are located in the south of South China Sea. The islands and coral reefs are scattered in the sea area. Area and other natural conditions of these islands are not the factors limiting intensive human activities, only if there are continued supplies from the mainland. But the supplies shipping to Nansha islands dotted in "Dangerous Area" are not easy jobs. At present, many islands, cays and reefs of Nansha Islands have been invaded and occupied by Vietnam, Philippines and Malaysia. The control states generated by these islands and reefs will affect the ships passing by. Considering the complex situation of Nansha, an accessibility index based on the least accumulative cost distance is proposed. The accessibility model of Nansha Islands and surrounding seaports is established based on the index. Two scenes of natural situation and control states are simulated to calculate the average access times between 23 islands or cays of Nansha and 9 surrounding seaports belong to the 4 countries. The result shows that the control states of islands have a great impact on the accessibility; as the main island of Nansha, Taiping Island gets the optimal accessibility to other islands or cays, which is very suitable to be built as the supply base; Seaports of Vietnam, Malaysia and Philippines get the optimal accessibility to the islands or cays in Nansha, therefore their control abilities to Nansha Islands are very strong and cannot be ignored. However, our seaports get the worst accessibility, so it is our top priority to set frontier supply bases on suitable islands, cays or reefs in Nansha so as to loosen the stress from surrounding countries. In current situation, Zhubi Jiao and Yongshu Jiao are the suitable options to be built as supply and transit bases for China. This research can be a reference for the development and management of Nansha Islands or decision-making of marine development.

Key words: Nansha Islands, accessibility, control state, the least accumulative cost distance (LACD), multiplicatively weighted Voronoi diagrams (MWVD)