Technical Calculation System Water (TBV) was developed within the consortium SMED to support Sweden's reporting to HELCOM and follow up the national environmental objective zero eutrophication.
With TBV estimated load from land to the sea was calculated as well as the source apportionment of nitrogen and phosphorus. In addition to load calculations TBV also store and manage a large amount of data.
TBV was used to compile Sweden's data for reporting to HELCOM under the Pollution Load Compilation (PLC). Apart from the PLC calculations, TBV was also used for calculations to follow-up the Swedish environmental target "Zero Eutrophication".
From PLC8 is not TBV used anymore. The loads are instead calculated by the HYPE model and made available through Vattenwebb (in Swedish).
Some of the input data and results in terms of gross and net load to sea are available at SMED Vatten's web page (in Swedish):
- PLC7 include the calculation of gross and net load for year 2017 and normalized for the period 1997-2016.
- PLC6 include the calculation of gross and net load for year 2014 normalized for flow for the period 1994-2013.
- SMED has also a web page with input data and results from PLC6.5, which represents the same time period as PLC6, but is calculated for a another sub-catchment division and with updated background leaching of phosphorus from agricultural land.
- PLC5 include the calculation of gross and net load for 2006 normalized for flow for the period 1985-2004.