Topography refers to the characteristics of the land surface. These characteristics include relief, natural features, and artificial (or man-made) features. Relief is the conjuration of the earth’s surface and includes hills, valleys, plains, summits, depressions, and other natural features, such as trees, streams, and lakes. Man-made features are highways, bridges, wharfs, buildings, and so forth. A graphic representation of the topography of an area is called a 'Topographic Map/Plan. A topographic map/plan is simply a drawing that shows the natural and artificial features of an area.
Using OS LIDAR DSM (Digital Surface Model) data we produce a 3D terrain and are able to extract topographical plans as the example below show.
Zone of Visual Influence / Zone of Theoretical Visibility
We also produce plans to demonstrate ZVI’s/ZTV’s which are formed from the OS LIDAR DSM data. This includes terrain features as described above, therefore providing a topographical model of the earths surface. The shaded areas (blue) indicates views into the site. This plan is used to cross referenced with publicly accessible areas so that the most sensitive viewpoints can be chosen to test the impact of the potential scheme against its surroundings.