The Water Emission Inventory planning Support System (WEISS): a quantification of environmental pressures following the path from the emission source to the surface water.

The Water Emission Inventory planning Support System (WEISS): a quantification of environmental pressures following the path from the emission source to the surface water.

According to the Water Framework Directive, Member States should achieve a good water quality by 2015. Especially in highly urbanized regions like Flanders, it’s not easy to attain these standards. In order to formulate cost-efficient mitigation measures, the in depth knowledge of the current status of the quality of water bodies, as well as the location of the most important emission sources is paramount. WEISS is developed to address these questions as part of a LIFE+ project carried out by VITO and the Flemish Environment Agency. It is to support the latter in its monitoring and reporting obligations. WEISS is a shell, highly generic and applicable in European watersheds and regions. It is explicitly spatial in its approach: for Flanders, calculations are made for 2.280.000 grid cells at a 1 ha resolution. WEISS incorporates both point and diffuse emission sources and essentially consists of three modules. The first deals with the spatial distribution of the emissions. To the effect it provides spatial algorithms to allocate surface, line and point sources, depending on the type, the detail and the spatial resolution of the information available in the specific study area. The second represents all relevant routes transporting the emissions, including direct discharges, the sewer system and runoff. The third is an accounting module. It enables consulting and reporting the calculations for specific spatial entities in terms of maps and tables in every node of the transport routes. WEISS stores information for several years and enables yearly and inter-annual computations and comparisons. Parameters can be altered and indicators can be computed to analyze the state of the water system as part of decision support exercises. Among others the location of newly built sewage pipelines, improved efficiency of treatment plants, materials used in buildings and infrastructure, etc. can be experimented with. WEISS is a software shell programmed in C++ and is linked to an MS Access database.