Study of Cartographic Generalization on Natural Disaster Risk Mapping-Taking Point Hazard-affected Bodies as an Example

Automatic cartographic generalization is a complex decision-making process of expressing objective law of geography,and is also the automatic cartographic generalization hot and tough issues.With little research on cartographic generalization of disaster risk mapping at home and abroad,while it has a more important practical significance for our country which has a vast territory,complicated hazard-formative environment,various kinds of disasters and vulnerable society and economy.To improve the expression accuracy and effectivity of hazard-affected body in high-risk areas of multi-scale disaster risk maps,based on disaster risk theory,under geographic laws,using data mining and spatial analysis technology,the map generalization problems of point hazard-affected body in the conversion process was discussed.Combining the hazard-affected body itself and its property characteristics in disaster systems,the types of cartographic generalization of point hazard-affected body in disaster maps were summed up,that are generalizations according to its importance,speciality,neighborhood,condition,integrity and randomness.For each generalization type,the possible disaster scenario assumptions and mapping generalization approach were given,as well as technical realization and visualization expression.The results show that,based on the above 6 types mapping generalization of point hazard-affected body,data redundancy problems during process of the scaling conversion was solved,and the spatial distribution of hazard-affected body in high-risk areas in special hazard-formative environment was exactly got.This study may provide theory and technical support for regional disaster risk identification,risk prevention and management,thus provide the scientific basis for regional disaster prevention and mitigation.