Risk Assessment Technology And Application Of Red Tide Disaster Based On Nutrient

In this paper the role of red tide disaster risk assessment in red tide disaster risk management is described, the research progress at home and abroad and the influencing mechanism of the nutrients on the red tide algal growth are systematic introduced; a hazard degree assessment model of Alexandrium tamarense red tide based on nutrients experimental data, the receptors'vulnerability assessment model, the quantification and classification of risk assessment of red tide disaster and the implementation of red Tide disaster risk assessment techniques are carried out; finally, the Zhejiang coastal waters is used to application.The theory of the risk assessment of red tide disaster is the basis for carrying out the work of risk assessment of red tide disaster. Risk assessment of red tide disaster is a new research field, and it has not yet formed a mature and systematic assessment theory and technical methods. According to risk assessment theory of red tide disaster has initially established, how to quantify the hazard degree of red tide disaster and the receptors'vulnerability degree are the two core contents.Hazard degree assessment of red tide disaster is an important part of the risk assessment of red tide. Nutrients are the material basis for the red tide algal growth. It is a key elements affecting red tide outbreak. On the basis of the impact mechanisms caused by nutrients, the experiments of nutrients and Alexandrium tamarense growth are conducted under the conditions of fixed intial phosphate and nitrate respectivly. a hazard degree assessment model of Alexandrium tamarense red tide is estabilished based on the nutrients experimental data and the related laws of algal growth, which solve the quantification question of hazard degree of red tide disaster based on nutrients.Receptors'vulnerability assessment is another important content of the risk assessment of red tide. It is affected by the counter-disaster characteristics of receptor-self, the spatial distribution of receptor, the types (or intensity) of red tide, and other elements. Delphi method is used to quantify a single receptors'vulnerability value caused by different types (intensity) of red tide. A receptors'vulnerability degree assessment model in cubical space is estabilished based on the stratification of receptors in the sea area waters, solving the quantification question of receptors" vulnerability degree. Finally, to further validate the reliability and the availability of the theory put forward in this study, Zhejiang coastal waters is used to apply. The spatial visualization of hazard degree assessment based on nutrients, receptors'vulnerability degree assessment and risk assessment are obtained based on remote sensing and GIS technology. The assessment results basically are consistent with the historical events of red tide in Zhejiang coastal waters. The case study shows that the research thinking and methodology from the paper will be useful to push forward the development of risk assessment of red tide disaster, and provide a theoretical basis for the effective prevention and reduction of red tide disasters.