Land and water areas of Helsinki

The dataset includes the land and water areas of Helsinki as geographic data features in the form of areas. Bridges and small piers have been removed from the land areas and added to the water mask. Large piers are classified as land areas: a pier is counted as a land area when it is surrounded by a retaining wall. In that case, the coastline goes around the pier. Smaller water bodies have not been dealt with so far, and for them, the water mask is not consistent. The dataset is automatically compiled from the data of the cadastral map and base map. The dataset is experimental, so small formation errors are possible. The dataset is also available with the official regional divisions (city districts, district divisions, excluding small districts), which can be used, for example, to present statistics. Generalised land data has been used in the division (small islands and water bodies have been removed from the dataset). In addition, the interface service includes layers for just the land in each area (it is intended to use this with a simplified water mask from the land and water base data). The data is divided into the following layers: — continental area (incl. all waters): Mainland (including all waters) — land generalisation (only largest waters and less than 500 m^2 islands removed): land area generalised (only the largest waters and islands smaller) than 500 m^2 removed) — sea area: sea area the islands: the Islands — other_water system: other_water_body — water area generalised (sea area and major other waters; includes islands exceeding 500 m^2): water area generalised (sea area and largest other water areas) includes islands larger than 500 m^2) The data is available for download in several formats, including JSON, KML, GIF, Tiff, GeoTiff, JPEG, PNG, CSV, Esri Shape. Available formats can always be found under OutputFormat in the [GetCapabilities query](https://kartta.hel.fi/ws/geoserver/avoindata/wfs?request=GetCapabilities) for the service. The datasets are heavy in geometrical properties, and their WFS download in GML format for older QGIS versions may take time or be interrupted depending on the speed of the internet connection, etc. It is faster to use the data directly in file format downloaded from the interface. For example, [all regional divisions from the interface as shapes] (https://kartta.hel.fi/ws/geoserver/avoindata/wfs?version=1.1.0&request=GetFeature&typeName=avoindata%3AMaavesi_kaikki_aluejaot&outputFormat=SHAPE-ZIP). There should be no problems with the WMS download. **Coordinate systems:** — Maintained in ETRS-GK25 (EPSG:3879), can be projected to other coordinate systems. See GetCapabilities query for other possible coordinate systems. **API addresses:** WFS API: [https://kartta.hel.fi/ws/geoserver/avoindata/wfs](https://kartta.hel.fi/ws/geoserver/avoindata/wfs?request=getCapabilities) — WMS API: [https://kartta.hel.fi/ws/geoserver/avoindata/wms](https://kartta.hel.fi/ws/geoserver/avoindata/wms?request=getCapabilities) **WFS-layers:** — Groundwater_all_divisions — Groundwater_urban areas — Groundwater_land_areas_generalised — Groundwater_continent — Landwater_sea area — Groundwater_other_water areas — Groundwater_sub-regions — Groundwater_basic districts — Groundwater_islands — Groundwater_majority districts — Groundwater_water area_generalised **WMS layers:** — Groundwater_land_areas_generalised — Groundwater_continent — Landwater_sea area — Groundwater_other_water areas — Groundwater_islands — Groundwater_water area_generalised — Groundwater_areas — Groundwater_areas_generalised **Attributes for all layers beginning with groundwater** — information service_id (int): Dataset ID. Reliable, comprehensively existing information. type (string): In the basic dataset: type of area, for example sea or mainland. With regional divisions: land or water area. — regionalisation (string): Type of regional division layers only. — sign (string): Identification of the regional division layers only. — name_fi (string): Name of the regional division in Finnish (regional division layers only). — name_se (string): Name of the regional division in Swedish (regional division layers only). — PA (float): The area. Process calculated data, not official area (regional division layers only). — data owner (string): Owner of the data. — flipped to the information service (date): Information service record date (yyyy-mm-dd). GEOM (geometry): Geometry of the feature. Administrator: City of Helsinki, Urban environment division, Service and permits, City survey services