This dataset reflects the spatial distribution of area specific inputs to the sea of total nitrogen and total phosphorus from different land-based sources. Area specific inputs to the sea are calculated for each sub-catchment designated for the HELCOM PLC assessment.

The sub-catchments are the smallest areas for which loads of nutrients and hazardous substances are assessed. Sub-catchments are always located within borders of a single country and drain into one Baltic Sea sub-basin. Sub-catchments may correspond to either monitored or unmonitored areas. Unmonitored sub-catchments may represent either unmonitored parts of river catchments or aggregated unmonitored areas (depending on the reporting format of each Contracting Party).

Area specific inputs to the sea are calculated applying the load-oriented approach (see PLC-Water Guideline, http://www.helcom.fi/Lists/Publications/PLC-Water%20Guidelines.pdf). It means that computed values reflect nutrient inputs from identified sources into respective Baltic Sea sub-basins, considering also retention in downstream sub-catchments.

The data on sources of nutrients is obtained through national monitoring programmes and periodically reported by Contracting Parties to the HELCOM Pollution Loads Compilation (PLC-water) database as an integral part of HELCOM Pollution Loades Compilation process. The data is produced, compiled and quality assured in accordance with the HELCOM Guidelines for the annual and periodical compilation and reporting of waterborne pollution inputs to the Baltic Sea (PLC-Water Guideline, http://www.helcom.fi/Lists/Publications/PLC-Water%20Guidelines.pdf).

Dataset content:

Polygonal feature class contains the following attributes:

1. Source_Code: Unique code for sub-catchment

2. Name: Name of river catchment or unmonitored area

3. SubBasin: Sub-basin of the Baltic Sea the sub-catchment drains to.

4. Country: Country on which territory the sub-catchment is located.

5. Polygon area in sq.km.

6. Retention of nitrogen (%)

7. Retention of phosphorus (%)

8. Area specific inputs of Nitrogen to the sea (kg/km2)

9. Area specific inputs of Phosphorus to the sea (kg/km2)

10. NBL_TN: Area specific background inputs of Nitrogen to the sea (kg/km2)

11. NBL_TP: Area specific background inputs of Phosphorus to the sea (kg/km2)

12. Diffuse_TN: Area specific total diffuse inputs of Nitrogen to the sea (kg/km2)

13. Diffuse_TP: Area specific total diffuse inputs of Phosphorus to the sea (kg/km2)

14. AGL_TN: Area specific agricultural inputs of Nitrogen to the sea (kg/km2)

15. AGL_TP: Area specific agricultural inputs of Phosphorus to the sea (kg/km2)

16. Dif_other_TN: Area specific diffuse nitrogen inputs to the sea from sources other than agriculture (kg/km2)

17. Dif_other_TP: Area specific diffuse phosphorus inputs to the sea from sources other than agriculture (kg/km2)

18. Trans_TN: Area specific transboundary nitrogen inputs to the sea (kg/km2).

19. Trans_TP: Area specific transboundary phosphorus inputs to the sea (kg/km2).

Visualization:

The following maps visualize the data on area specific loads of nutrients from various sources:

• Retention of Nitrogen (%)

• Retention of Phosphorus (%)

• Area specific total inputs of Nitrogen to the sea (kg/km2)

• Area specific total inputs to the sea of Phosphorus to the sea (kg/km2)

• Area specific background inputs of Nitrogen to the sea (kg/km2)

• Area specific background inputs of Phosphorus to the sea (kg/km2)

• Area specific total diffuse inputs of Nitrogen to the sea (kg/km2)

• Area specific total diffuse inputs of Phosphorus to the sea (kg/km2)

• Area specific agricultural inputs of Nitrogen to the sea (kg/km2)

• Area specific agricultural inputs of Phosphorus to the sea (kg/km2)

• Area specific diffuse Nitrogen inputs to the sea from sources other than agriculture (kg/km2)

• Area specific diffuse Phosphorus inputs to the sea from sources other than agriculture (kg/km2)

• Area specific transboundary inputs of Nitrogen load to the sea (kg/km2).

• Area specific transboundary input of Phosphorus load to the sea (kg/km2).