Klas Persson

General quantification of catchment-scale nutrient and pollutant transport through the subsurface to surface and coastal waters.

This study develops a general quantification framework for consistent intermodel and intercatchment comparison of the nutrient and pollutant mass loading from multiple sources in a catchment area to downstream surface and coastal waters. The framework accounts for the wide spectrum of different transport pathways and travel times through the subsurface (soil, groundwater, sediment) and the linked surface (streams, lakes, wetlands) water systems of a catchment. The account is based on key flow partitioning and mass delivery fractions, which can be quantified differently by different flow and transport and reaction models. The framework application is exemplified for two Swedish catchment cases with regard to the transport of phosphorus and of a generic attenuating solute. The results show essential differences in model quantifications of transport pathways and temporal spreading, with important implications for our understanding of cause and effect in the catchment-scale nutrient and pollutant loading to downstream waters.

Impacts of the water framework directive on learning and knowledge practices in a Swedish catchment

Catchments are complex social-ecological systems involving multiple, and often competing, interests. Water governance and management regimes are increasingly embracing pluralistic, participatory, and holistic norms as a means to engage with issues of complexity, uncertainty, and value-conflicts. Integrated, participatory approaches are theoretically linked to improved learning amongst stakeholders across sectors and decision-making that is grounded in shared knowledge, experiences and scientific evidence. However, few studies have empirically examined the impacts of an integrated approach to learning and knowledge practices related to water resources. Here, a Swedish sub-catchment that has adopted such an approach in association with implementation of the European Water Framework Directive (WFD) is examined. Interview-based analyses show that WFD implementation has both helped and hindered learning and knowledge practices surrounding both water planning and spatial planning. Whilst communities of practice have developed in the study area, a number of important challenges remain. These include the rigid goal-orientation of the WFD, the fragmentation of knowledge caused by an over-reliance on external consultants, as well as a lack of resources to synthesise information from multiple sources. Present results raise questions regarding the efficacy of the WFD to sufficiently enable the development of learning and knowledge practices capable of handling the complexity, uncertainties and value-conflicts facing catchments in Sweden and elsewhere.

Propagation of environmental risk from contaminant transport through groundwater and stream networks

We use a Lagrangian stochastic advective-reactive (LaSAR) approach to model coupled groundwater and surface water contaminant transport. In this approach, physical (advective) solute travel time di ...