Illustration from Kalmar Län
DHI has been awarded a contract from Länstyrelsen in Kalmar, Sweden, for development and delivery of catchment models for simulation of transport and concentrations of phosphorus and nitrogen in “Södra Östersjöns Vattendistrikt”. Kalmar Län serves as the water district authority in Sweden’s southernmost water district covering all areas discharging to the Baltic, from Bråviken to the east (near Norrköbing between the northernmost point of Øland and Stockholm) and to the Sound to the west. The results from the catchment modelling will be used by Länstyrelsen in their water planning process in connection with implementing EU Water Framework Directive.
The model to be used is DHI’s catchment model MIKE BASIN – a GIS integrated modelling system especially developed to simulate water balances, substance load and water quality at catchment level.
In 2006, the Swedish government earmarked 3 million DKK. for the water authority to locate the areas responsible for the largest nutrient load contribution to the coastal areas.
The first task of this assignment will be to deliver a suitable model tool and perform detailed studies in two selected catchment areas in “Södra Östersjöns Vattendistrikt”. The purpose is to quantify the effect of different measures and analyse which measures will result in the largest effect on the N and P transport to the coastal areas. The final analysis will comprise economic considerations including the relative cost effectiveness of each individual measure. The assignment will also contribute to set standards for the future Swedish catchment modelling in connection with the EU Water Framework Directive.
The model system was used for similar studies in the Baltic region, for instance in Lithuania and in Estonia. In Lithuania the model was set up for the country’s largest water district, Nemunas, in connection with the implementation of the Water Framework Directive. In 2007, the results formed the basis of the water plans which the Lithuanian environmental authorities prepared for all water areas in the district. DHI expects that profit can be drawn from the experience with these assignments and the existing tools also in Denmark where there are no standards at present as to how this work should be carried out. The actual water planning process is already in full swing in the regional environmental centres, and DHI has already applied GIS integrated catchment modelling in connection with a project in the catchment areas around Susåen and Ringkøbing Fiord. When water plans and mitigation plans are published during the next six months, the municipalities which are to implement and make the plans operational will need effective and price-worthy tools – tools and solutions which DHI is ready to supply.