Evaluation on deep-water cage culture suitability of Changhai County based on GIS

For the scientific planning of deep-water cage culture sea, this paper constructs a comprehensive suitability evaluation index system for deep-water cage culture, uses AHP to determine index weights, and calculates the Comprehensive weighted suitability index. Based on GIS the spatial statistics and analysis of the suitability results were carried out, and the Changhai sea area was taken as an example for case study. The results show that the suitable sea area for deep-water cage culture is 7045.81 km(2), accounting for 65.31% of the total sea area of Changhai county. The most suitable sea area for deep-water cage culture is distributed around Guanglu and Gexian Island, the southern part of Zhangzi Island, the sea area between the Shicheng Island and Wumang Island and the southern part of the Haiyang island, with an area of 1248.38 km(2), accounting for 11.57%. The higher suitability sea area is widely distributed around Zhangzi Island, Haiyang Island, Wumang Island and Xiaochangshan Island, covering an area of 2279.56km(2), accounting for 21.13%. Due to the combined effects of chlorophyll concentration and distance from town areas, it is not suitable for deep-water cage culture area mainly distributed in sea areas far away from land and islands, with an area of 814.81 km(2), accounting for 7.56%. The study can provide reference for the sea planning and sea area management of aquaculture in Changhai county.