Glossary
Thematic Map
Thematic map includes land use map, soil map, geological map, drainage map, forest map etc.
Thiessen Polygon
Polygons which are created as the intersections of radial expansions from the observation points. Distance from a point on the boundary to the adjacent observation points is equal. It is sometimes called Voronoi tessellation.
TIN
Triangulated irregular network is a DEM by which the terrain surface is represented by a set of triangular planes.
Topology
Relationships or connectivity between spatial objects including start and end node, sequential order, left and right side, is within, on line, is nearest to, on border of area etc. Topology is a relative geometric relation which is not changed by transformation.