Sveriges lantbruksuniversitet

Our models

What questions should be answered? What data are available? Is the area of concern a small scale (part of a field), national or something in-between? Different models fit different applications and thus we are working with many different models.

A field of wheat. Photo.

Model overview

The models now included in SLU's toolkit for modelling of nutrients in catchment areas can roughly be divided into two types - models for calculating the leaching of nitrogen and phosphorus from agricultural land, and models for the calculation of water balances, transport and turnover of nutrients in rivers and lakes. The former category include the models SOILNDB and ICECREAMDB and the latter FyrisNP, FyrisQ and FyrisCOST. These models have been fully or partially developed at SLU in various research projects and applied in the context of environmental monitoring and assessment.

SOILNDB and ICECREAMDB are included in a system for calculating the leaching of nutrients from arable land called NLeCCS. The calculation system is used for applications at the national and regional level. One application is the buffer zone database FyrisSKZ. FyrisNP and FyrisQ have so far primarily been used in various assignments at the regional level.

In the context of the consortium SMED SLU participates in the development of TBV. The system includes the storage of background data and results on nitrogen and phosphorus load of water and transport to the sea.

Apart from the models already described do we also use and/or develop the models INCA, PERSiST, SWE-model, SWAT och USPED.

A fence that goes from grassland down into the sea, in the archipelago of Karlskrona, Sweden.

Examples of applications

  • Calculation of the load of nitrogen and phosphorus from Sweden to the sea for reporting to HELCOM within the SMED consortium on behalf of Swedish Agency for Marine and Water Management (SwAM).
  • Follow up of the Swedish environmental goal "zero eutrophication" on behalf of SwAM. Analysis of the load of nutrients from land to the sea during different years.
  • Calculation of the nutrient leaching from Swedish agricultural land and evaluation of the causes to the changes.
  • Follow up of the effects of CAP (Common Agriculture Policy) and measures programs for nutrient reduction on behalf of Swedish Board of Agriculture.
  • Source apportionment of nitrogen and phosphorus in different catchments and scenarios of different nutrient reduction measures.
  • Calculation of climate effects on leaching, retention and transport of nutrients from land to sea. 
  • Knowledge exchange with Russia, the Baltic countries and Serbia.