Kartlager

Kartlager is a term used in geographic information systems (GIS) to denote a single dataset that is layered on top of a map to represent geographic features. A kartlager may contain vector data such as points representing cities, lines for roads, or polygons for administrative boundaries, as well as raster data like aerial imagery or digital elevation models. Each kartlager carries its own attributes and styling rules, which determine how features appear on the map.

In GIS practice, kartlager are organized into layers to enable flexible map composition, data management, and performance optimization. Layers can be base layers, providing underlying geographic context, or overlay layers, which add thematic information. They can be stored in various formats, such as shapefile, GeoJSON, KML, or GeoPackage, or in spatial databases like PostGIS. Raster layers include satellite imagery and elevation data, while vector layers include points, lines, and polygons with attribute data.

Visualization and interaction are controlled by layer properties, including visibility, transparency, drawing order, and scale-dependent rendering. Metadata describes provenance, coordinate reference system, data source, update frequency, and licensing. Interoperability standards support sharing and integration, including Web Map Service (WMS) and Web Feature Service (WFS) from the Open Geospatial Consortium, as well as data formats like GeoJSON and GML.

Kartlager are essential for tasks such as urban planning, environmental monitoring, navigation, and cartographic production, enabling modular and flexible map creation.