GIS Glossary

A text markup language for representing vector geometry objects(points, lines, polygons) in GIS, facilitating data exchange and interoperability (standard GIS usage).

An OGC standard protocol for serving georeferenced map images over the internet, enabling integration of distributed spatial data in web mapping applications (standard GIS usage).

An OGC standard for serving map tiles (pre-rendered image tiles) over the web, improving the efficiency and speed of web-based map visualization (standard GIS usage).

A geographic area that drains all precipitation and runoff to a common outlet, such as a river, bay, or other body of water. Watershed analysis is fundamental in hydrology, land management, and environmental spatial studies (standard GIS usage).

A specific geographic location defined by coordinates, often used in navigation, field data collection, and route planning (standard GIS usage).

A system that enables the sharing, visualization, and analysis of GIS data, maps, and spatial processing over the internet or private networks. Web GIS supports collaborative spatial analysis and broadens access to spatial data and tools.

A spatial analysis technique where multiple raster layers are combined using assigned weights to evaluate suitability or risk, commonly applied in site selection and multi-criteria decision analysis (standard GIS usage).

A small text file that provides georeferencing information for raster images, allowing them to be accurately placed in a GIS coordinate system (standard GIS usage).

The horizontal value in a pair of coordinates (x, y) that specifies a location in two-dimensional space. In GIS, x typically represents longitude (east-west position) or the easting value in projected coordinate systems.

A pair of numerical values that define the position of a point on a plane, with x representing the horizontal (east-west) position and y the vertical (north-south)position. These are fundamental for mapping and spatial data representation in both vector and raster GIS.

An extension of x, y coordinates to include a z value, which represents elevation or depth, enabling three-dimensional spatial analysis.

The horizontal axis in a Cartesian coordinate system, used as a reference for measuring x coordinates in maps and spatial datasets.

In some GIS applications, refers to the slope or rate of change along the x-axis direction, useful in terrain and surface analysis.

The vertical value in a pair of coordinates (x, y) that specifies a location in two-dimensional space. In GIS, the y coordinate typically represents latitude(north-south position) or the northing value in projected coordinate systems.

The vertical axis in a Cartesian coordinate system, used as a reference for measuring y coordinates in maps and spatial datasets.

In some GIS applications, refers to the slope or rate of change along the y-axis direction, useful in terrain and surface analysis.

A unit of length sometimes used in GIS for measurements, especially in the United States.

In a three-dimensional coordinate system, the axis representing vertical position (elevation or depth), used alongside x and y axes to define locations in 3D space.

The third coordinate in a 3D spatial reference system, specifying the vertical position of a point (e.g., elevation above sea level).

A scaling factor applied to z-values to convert elevation units (for example, from feet to meters) or to exaggerate vertical relief in 3D visualization.