Summarising and upscaling different benefits ...

Wetland buffer zones (WBZs), as areas between agricultural land and a water body, support wetland ecosystemsand protect surface water from non-point source pollution, in addition providing other ecosystem services. “CircuLar Economy Approach to River pollution by Agricultural Nutrients with use of Carbon-storing Ecosystems” project (CLEARANCE) addresses the global environmental challenges -limited access to good quality water coupled with climate change, resulting in profound adverse social and economic effects. It seeks wetland solutions forclean water provision and restoration of vanishing riverine nature.We propose ecological types of WBZs along water courses in selected casecatchments in Poland(five tributaries of Narew river), Germany (Ryck river) and Denmark(Odense river), spatially delineate the WBZs and analyse benefits and costs of their potential implementation. Assessmentsof benefits accompanying WBZs development isconducted for severalscenarios of WBZ development differing withscale of their application. Such an approach allows to evaluatebenefits of synergistic functions of WBZs, in terms of economic gains and reduction of pollutants (circular economy & resource efficiency perspective). CLEARANCE focuses mainly on benefits coming from nutrient capture potential (which effectiveness differs depending on WBZ type)and wet agriculture. The project copes with valuation of other ecosystem services i.e. reducing the risk of floods and droughts, sustaining and increasing biodiversity, regulation of local climate and mitigation of the global climate change.For selected scenarios, costs of WBZs development are also calculated. Each type of WBZ is linked to intervention elements needed for its establishment e.g. excavations, land purchase, etc. For each element, total costs are estimated based on standardized cost per unit length or area, actual size of the feature and type of WBZ. These costs are then summarized for all WBZs in a sub-catchment, including intervention phase and maintenance phase. We present this approach using: 1) benefits versus costs for different scenarios of WBZs development in CLEARANCE casecatchments, 2) upscaled project results for the whole catchment of Lower Narew (Poland).