Geology is a subsurface data management application that allows a user to store and analyze geologic and hydrogeologic data. Geology can be connected with ArcView to display soil borings, fenceline diagrams, and solid models. It can also linked with GMS to develop groundwater models. A TIN is simply a set of points that are connected to form triangles. Each point has an x and y coordinate along with a z coordinate that refers to a unique attribute of the coverage, such as an elevation or concentration measurement.
TINs are useful because they provide better surface representations than DEMs.
In a DEM, each grid cell is the same size and has only one elevation value, but in a TIN, each triangle encompass a range of elevations. The figure below shows a TIN for part of an oil refinery. A creek runs through the left side of the image, and there is a lagoon in the center. A TIN can also be created from a point coverage of survey measurements, which is a useful tool for many engineering design applications. Analyst adds a 3-D scene viewer to the project window.