karttatasoa

Karttatasoa is the Finnish term used in geographic information systems to refer to a distinct set of geographic features and their attributes that can be displayed independently on a map. A karttataso may be vector or raster, and may include points, lines, and polygons, along with attribute data and styling information (symbology). In practice, layers are organized into base layers (taustakartta) that provide contextual information, and overlay layers that add thematic data such as roads, land use, or administrative boundaries. Layers can be combined, reordered, turned on or off, and analyzed separately or jointly.

Common data formats and standards govern karttatasot: vector formats such as Shapefile, GeoJSON, or GeoPackage; raster formats such as GeoTIFF; services such as WMS, WFS. Metadata describes the source, accuracy, update frequency, and licensing, with standards like ISO 19115 and INSPIRE guiding European data sharing. In software, karttatasot are used in desktop GIS like QGIS or ArcGIS, and in web mapping with libraries such as Leaflet or OpenLayers, enabling interactive maps where users toggle layers, query attributes, and perform spatial analyses.

Challenges include data quality, interoperability between systems, licensing, and keeping data up to date. Karttatasoa is central to modern cartography and spatial analysis, forming the building blocks of maps and geospatial applications.