The remote sensing composite information entropy and types of Nasha coral reef atolls

In the viewpoint that the oaral reef atolls' growth index of the Nanshe Islands is influenced by many factors,the measured remote sensing composite information including scmae mutually related factoes is divided inw 10 geographic events as N₁,N₂,…,N₁₀,and the analysis of the atolls' information entropy is made.From the value of the entropy,the closed related factors with the index of the emerged atolls are shown.In proper order,the factors are reef top's area (0.319),lagoon's area (0.324),open-degree of atoll (0.336),trend of atoll (0.551).On the basis cd this work,a new description function of the emerged atoll growth index is proposed.This function can be used to identify the open type of Nansha atoll growth.