Study On Map Color Design For Red-Green Color Blindness

Maps, which are the carriers and transmission mediums of geospatial information, are important in our usual work and lives. The mapping technology changes revolutionarily with the development of science technology especially that of the computer technology applied to the field of cartography. The varieties and forms of maps have been gradually enriched from the two-dimesional maps to the three-dimesional ones and from the static maps to the dynamic ones. In this development, one thing that should to be paid attention to is the feelings of different map users, especially to those who have the obstacle in reading a usual map. The achromates, who is one part of these groups and takes up eight percent of total global population, are need some special types of map for their better reading experiences. Therefore, it is necessary for map designers to create more easy reading maps for these groups of users.Because achromates can hardly distinguish some colors, they may be confused by the colors and misunderstand the information expressed in a usual map. So, this paper aims to discuss the principle and the methodologies of designing chromatelopsia maps based on the features that how the most achromates distinguish colors. And it is also on purpose to design the maps which information can be easily read and reflected to achromates.This paper firstly studies on both the quality and the quantity characters of the cartographic targets. Then, it systematically researches on the map coloring methods and the ways of representing the accurate information of both the quality and the quantity characters of the cartographic targets for the red-green blindness. In addition, the basic principle and the method of the available map coloring for the red-green blindness are proposed.By coloring a tourist map, a further analysis of the way of representing a tourist map, its characteristics and the color confusing ranges, from the aspects of symbols of point, line and area, etc., are studied. The principle and the method of coloring symbols for the red-green blindness are also studied from this experiment. And it is proposed that the color expression methods based on the semantic categorization of the cartographic targets.Another experiment on the graduation statistics of coloring map are studied to figure out whether the red-green blindness's color confusion will make the information from a map mismatched and the color graduation for the red-green blindness is the same as that for other people. The experiment has been divided into several parts based on the different combinations of the graduation levels, the single hue and many hues from the statistic maps. The results show that, in the experiment of the coloring graduation with the single hue, the red-green blindness can easily get the correct information that the map represents, while in that with the many hues, they can hardly distinguishing the colors. This is because when the confusing colors are combined, the red-green blindness can hardly recognize the quantity information of the cartographic target in the map represented by the graduation coloring.Finally, the basic principles and the methods of coloring map are concluded based on the experiments of the tourist map and the graduation statistics of coloring map.