1. A terrain representation method representing the terrain through processing implemented by a processor and comprising: reading digital elevation model (DEM) data of a terrain using a hardware DEM reader; extracting feature points of the terrain from the DEM data using a hardware terrain feature extractor; creating terrain primitives according to the extracted feature points using a hardware terrain primitive creator; and generating terrain representation model data using a hardware terrain representation apparatus, based on the terrain primitives, as a DEM data, and visualizing the DEM data using a hardware terrain visualizing unit, wherein each terrain primitive is defined as a curved surface represented by a radial basis function whose vertex is a corresponding feature point, and is additionally defined by a terrain feature point corresponding to the vertex and connection information for connecting the corresponding feature point to another terrain feature point which is adjacent and connected to the corresponding terrain feature point, and wherein the calculating of each terrain primitive comprises calculating rates of change in height values of left and right grid points positioned in a normal direction to edges between terrain feature points adjacent and connected to one another.