Total amounts of nutrients in sub-basins

 

By contract with the Swedish Environmental Protection Agency SMHI is obliged to report calculations of the total amounts of nutrients in different sub-basins. Click on a sea area below to get more information. Available at this time is total amounts of nutrients.


Total amounts of nutrients



Klicka på önskat havsområde för att visa totala mängden närsalter. Bilden visar havsområden men även delar av Östersjön avrinningsområde.


Determination of total amounts of nutrients in sub-basins:

  1. All data collected during the period of interest (1: Jan-Mar, 2: Apr-Jun, 3: Jul-Sep, 4: Oct-Dec) are extracted from the data base SHARK.

  2. For each sub-basin, two or three depth intervals are determined (surface water, intermediate water, deep water) by using CTD-profiles taken at the standard frequent stations.

  3. By using another data programme, BALTMAP (Wulff, System Ecology, Stockholm University), the volume of each depth interval in each sub-basin is calculated.

  4. A mean value for each nutrient is then calculated, using all data in each sub-basinand depth layer. In the calculations, different stations have different weight depending on how large area they represent.

  5. This volume multiplied by the mean concentrations gives the total amounts of nutrients in each area.

  6. Diagrams are shown for the surface layer and the whole water mass.