The concept of symbol-morpheme and its application in map symbols design

The essence of map symbols is a psychological unity which contains geographical concepts and visual graphics. Several problems that exist in current researches on map symbols were analyzed: focusing on the visual graphics but paying little attention to the semantics, constructing the structure model of map symbols without unifying the concepts and visual graphics, and not fully investigating the relationship among different symbols. A concept of Symbol-morpheme was put forward which was the minimum graphic-concept unit in the map symbol structure, and was the bridge which connected the visual graphics and geographical semantics of map symbols. A map symbols description model was constructed which centered on the Symbol-morpheme and considered the visual graphics and concepts comprehensively. This model linked the cognitive structure of map symbols with the human's cognitive structure of geographical objects. A design method of semantic-driven hierarchical map symbols was proposed, in which the control of semantic relationships made the map symbols system more regular and scientific. And a group of cognitive experiments had been carried out which shown that the propounded method had a superior performance in cognitive efficiency and higher transmission efficiency in the analog process of information transmission.