有效选择重点监控区并对其进行长期监测是赤潮预警系统建立的关键。本文研究海南岛近岸海域赤潮发生历史记录,分析不同区域赤潮发生频次、规模、危害程度及原因种毒性,提取赤潮发生的综合信息,评价区域赤潮的严重程度;同时分析近岸海域的营养盐状况及水体的扩散能力,评价水体的富营养程度;利用GIS手段,判断海南岛近岸海域赤潮易发程度,即识别赤潮高发区、赤潮易发区及潜在赤潮发生区。再结合近岸海域环境功能区划,有效划定了赤潮重点监控区,赤潮防控区及赤潮预警区。进一步结合现场大面调查数据对重点监控区进行分级,提高了赤潮的有效监控和预警。 Effective selection of key monitoring areas and their long-term monitoring is the key to establishing a red tide warning system. In this paper, the history of red tide occurrence in the coastal waters of Hainan Island was studied. The frequency, scale, degree of hazard and the species of toxicity were analyzed. The comprehensive information on the occurrence of red tide was extracted and the severity of red tide was evaluated. Status and the diffusion ability of water bodies, and evaluate the eutrophication degree of water body. By means of GIS, the degree of red tide proneness in coastal areas of Hainan Island is judged, that is, the areas with high incidence of red tide, the prone areas with red tide and the potential red tide occurrence areas. Combined with the environmental zoning of coastal waters, the key monitoring areas for red tide, the red tide zone and the red tide early warning zone are effectively delineated. Combining with the survey data of large-scale on-site surveys, the key monitoring areas were graded to improve the effective monitoring and early warning of red tide.