Uoma Information System

The national river system contains basic physiographical and hierarchical data on rivers above a catchment area of more than 10 km² as well as on the routes formed from them. In addition, the root system also includes rivers with water management significance of less than 10 km² above the catchment area. The Uoma Information System’s network does not in itself describe a water body in accordance with the definition of water in the new Water Act. The Uoma Information System consists of a network database and a spatial data set that can be linked to it by means of the system identifiers (Ranta10; network 1:5 000-10,000). A unifying and topologically unified network of shoreline data (MML) of the terrain database has been created in SYKE with its pseudonumerals crossing the lakes. The channel changes to a second unique channel code and the route information always at the junction of the river network and at the confluence of the river and lake. The Uoma Information System is integrated with the network application developed in the Environmental Administration’s ArcGIS Geographic Information Programme and with the information system sections describing lakes and catchment areas of the Environmental Information System. The Uoma Information System can be accessed through SYKE’s Hertta and Open Information services. The data is part of SYKE’s open datasets (CC BY 4.0) The national network information system covers Finland’s main river basins as well as the islands of the sea areas. The Uoma Information System with its applications and spatial data sets serves very extensively the use and management of water resources, water protection and water research, as well as international and national reporting and information system work related to water resources. For more information: Ranta10 and network network The network was created as a geospatial dataset of the Uoma Information System based on the Ranta10 beachline dataset created from MML’s terrain database. In the Ranta10 data, the central lines of the rivers and the pseudonyms crossing the lakes have been added to the Ranta10 data, and the possible breakages have been corrected in order to create a network that connects topologically wholeness. The Ranta10 data is based on data from the National Land Survey’s terrain database for 2000-2008 (1:5 000-1:10 000). Of the objects included in the waters of the terrain database, stable waters and current waters of more than 5 m wide have been included. In addition, there are pools larger than 200 m² in the terrain database. The streams below 5 m in width described as lines include the main flow routes of the water body, including both 2-5 m wide and less than 2 m wide streams. The data has been reclassified and topology reviewed in SYKE. A preliminary network meeting the catchment area size criterion above 10 km² has been modelled in a hydrological modelling process using the nationwide 25 m altitude model of the MML. In order to improve the accuracy of hydrological modelling, the flow paths of the elevation model have first been highlighted by “burning” the rivers and waters of the Ranta10 beachline data at different depths. The Regional Environment Centres (currently the ELY) have revised the modelled network for flow directions and routes and complemented the network with regionally important sites. If necessary, rivers with water management significance of less than 10 km² above the water catchment area have also been added to the network. The final network is formed by the equivalents of these modelled and revised lines in the Ranta10 dataset. Each channel of the network has been assigned a unique route code. The channel changes to another one always at the junction of the brooks belonging to the network and at the junction of the river and the lake. Basic physiographic and hierarchical data are defined for each channel network using MML’s 25 m altitude model and Ranta10 beachline data. Basic physiographic information is also specified for the urinary pathways. 13.9.2016: The network has also been upgraded to cover marine islands (increased 87). In addition, the network of cross-border areas at the Arm has been supplemented (36 lines added). The characteristics of the new channels are partially incomplete so far. Missing data will be completed later. 12.5.2015: The network has been updated for about 350 channels (increased or modified). The characteristics of the updated channels are partially incomplete so far. Missing data will be completed later. Routes in which updated channels are included are not yet shown.