Detection of seagrass in optical shallow water with Quickbird in Xincun Bay of Hainan province, China

Seagrass, mainly distributed in the coastal water along South China Sea, is very important for coastal ecosystem. In order to obtain precise data about seagrass distribution in optical shallow water in Xincun Bay of Hainan province, Quickbird data was used in the paper. Radiance transfer model in optical shallow water was used to retrieve the information of bottom reflectivity, and supervise classification was used to retrieve the distribution and density of submerged seagrass; Results showed that seagrass distributed in the northeast coast of Xincun Bay with the pattern of stripe can be clearly detected. Density gradient was very clear, coverage under 20% was mainly distributed at the out range of seagrass bed and coverage greater than 80% distributed in the centre of the seagrass bed. The accuracy of seagrass retrieval was more than 80% and the density of seagrass can also be distinguished evidently.