What's new – National hydrological corrections and Land Cover for Poland

Nov 30, 2021

We frequently update the Polish model as new input data (e.g. elevation data) become available. However, today we are releasing a particularly exciting new update of our Polish setup. We have produced a national set of so-called hydrological corrections for all of Poland, and we have also added a national land cover map - both based on GuGiK BDOT10k data.

Hydrological corrections

Hydrological corrections make it possible to model water that flows under objects like bridges that otherwise appear as barriers in the elevation model. For instance, when a stream crosses a road under a bridge, the elevation model could make it look like there is a blockade since the space under the bridge is not represented. Our hydrological corrections should result in improved flow routing in many places in the country, particularly where bridges and underpasses intersect flow paths.

Corrections (redline segments) and flow accumulation in an area south of Gdańsk. Without the corrections, water would not be able to flow freely in this area due to the bridges acting as dams.

If you want to learn more about how the corrections were generated, please consult the corresponding section in the documentation. The hydrological corrections are used in our analyses and are automatically included in newly created workspaces where they can be altered if need be.

National land cover data

We have built a national land cover layer from BDOT10k. This means you will now get information about the land cover composition of any watershed you select using the watershed tool. Additionally, you can easily add infiltration to Flash Flood Maps in your workspaces by picking different runoff functions for the various land use categories. Not happy with our land cover map? You can edit it freely using our powerful edit tools in workspaces.

For more information about adding infiltration to your Flash Flood Map, and about editing land cover data, please consult our recent release notes on the subject.

Screenshot from SCALGO Live Poland showing a watershed query in Warsaw and the distribution of land cover in the watershed.