南沙群岛封闭环礁空间结构的遥感信息与数学模型

阐述了造礁珊瑚生长发育的诸多条件，形成珊瑚环礁的地质背景与漫长的历史过程，珊瑚环礁的地貌特征与环境动力条件的密切关系，依据珊瑚环礁发育的规律及其表观的光谱响应特征，建立了封闭环环礁空间结构的数学模型,此模型与印证的结果是理想的，对于南沙群岛大片航行危险地带和暂不能入区进行研究有着重要的意义。

Remote-sensing Information and Mathematical Model of Spatial Structures of Closed Atolls on Nansha Islands

This paper summarizes the growing conditions, geological backgrounds and evolutionary processes of coral reefs. It discusses the close relations between the geomorphic features and the environmental dynamic conditions. The present survey unveils that the coral atolls on Nansha Islands develop on a series of terraces with water depths over 1?000 m, which indicates that the development of atolls is closely related to the tectonic movements, such as sea?bottom expansion, drift and subsidence etc. Analyses of remote?sensing data show that there are four types of coral atolls on Nansha Islands, namely almost?open atoll, almostclosed atoll, closed atoll, and platform?reef atoll. The NE?SW trend direction of the coral atoll is controlled by the base fractures. In addition, the north?east and south?west currents are also main dynamic factors influencing atoll growth. The basic approaches to interpretations of the remote?sensing images include the spectrum radiative, spatial, temporal and polarizing characteristics of the coral atoll. Based on the developing mechanisms and the spectrum response of the atoll, we have developed a mathematical model of spatial structure of the atoll. The results of experiments on the model are sucessful, which is of important significance not only in navigation in such dange?rous areas, but also in scientific research of the area.