Cartographic Representation Of Object Balance Theory

With the rapid development of GIS technology,computer technology and Internet technology,the representation of maps has also become various.The traditional map representation method usually uses a single scale as the standard,selects various types of features on the map,and displays the features that meet the requirements of the scale on the map,which tends to cause the map content to be unevenly distributed on the map.In some areas,the features are dense,the map content is too rich,and map users cannot quickly identify.In other areas,the features are sparse,the map content is too simple,and the map page resources are wasted.The map users cannot obtain useful information.In this paper,the basic concept of map object balance is proposed,and the construction theory and method are researched from the point of the laws of the cartographer’s own understanding activities and map users’ understanding activities.The main work of this paper includes the following three aspects:(1)The basic principles of map representation is researched,and the theory of visual balance is focused on.Based on this,the basic concept of object balance is put forward.The basic principles followed by the representation of maps based on object balance are proposed and the idea of balancing elements is designed to achieve the purpose of object balance.(2)The implementation methods of point object balance and line object balance are researched respectively.In the implementation methods of point object balance,the distribution of the number of features in the graphic display is used as an indicator to evaluate whether the features have reached balance.First,the map area is divided according to features aggregation and the scales of different areas are determined.The scale is only used as the criteria for selecting elements,and does not change the position and distance of each feature’s in the map and the position and distance consistent with the position and distance of the original scale;then,the features in the geodatabase of the corresponding scale are extracted in the feature-sparse area to achieve the effect of adding the elements,and the features are thinned in the feature-intensive area;finally,the topology errors are checked and modified.The method of line object balance is almost the same as that of point object balance.However,the evaluation index of line object balance is the distribution of feature lengths in the display.In addition,the specific method operation is also different.(3)Taking the example of Sichuan Province’s residential area features and highway features,a map representation experiment based on feature balance is performed.By comparing with the traditional map representation,we obtains the map representation both in terms of map content richness and map content balance.The method has obvious advantages and can improve the readability of the map.