Storm event impacts on in-stream nitrate concentration and discharge dynamics: A comparison of high resolution in-situ measured data with model simulations.

The relationship between nitrogen and discharge (N-Q) in a stream can be captured with high frequency nitrate nitrogen (NO3--N) samplers. In Austria, the Raab catchment (998 km2) has high frequency NO3--N data measured with a spectrometer probe. This study evaluated if the widely-used and typically calibrated eco-hydrological model Soil and Water Assessment Tool (SWAT) can reproduce the hysteresis loop direction and the dilution or accretion effects of NO3--N dynamics during storm events in this agricultural catchment. The daily aggregated NO3--N measurements were compared with the daily SWAT simulated discharge and NO3--N concentrations of 14 storm events by computing hysteresis indices - loop direction and area (h index), loop direction (HInew) and solute gradient (∆C). Overall, the SWAT model was able to replicate the predominant anticlockwise hysteresis and dilution effect of NO3--N in the Raab catchment. The loop direction was simulated correctly in 9 and 10 events, for the h and HInew indices, respectively. The hysteresis direction inferred from both indices did not always concur due to the differences in the calculation methods. The dilution or accretion effect was simulated correctly in 9 of the events. However, the SWAT model only correctly simulated the N-Q relationships for all three hysteresis criteria in 5 of the 14 events. Due to the aggregation of measured data to the daily time step, information pertaining to the hysteresis shape was sometimes lost, particularly if the storm event was <4 days in duration. Structural limitations of the SWAT as well as specific relevant basin parameters (parameters that have one value for the entire catchment) may restrict simulating N-Q dynamics. An enhanced calibrated and validated model would possibly improve the results, since the events during the better calibrated period more often reproduced the measured hysteresis indices.

Shared Socio-economic Pathways for European agriculture and food systems: The Eur-Agri-SSPs.

Scenarios describe plausible and internally consistent views of the future. They can be used by scientists, policymakers and entrepreneurs to explore the challenges of global environmental change given an appropriate level of spatial and sectoral detail and systematic development. We followed a nine-step protocol to extend and enrich a set of global scenarios - the Shared Socio-economic Pathways (SSPs) - providing regional and sectoral detail for European agriculture and food systems using a one-to-one nesting participatory approach. The resulting five Eur-Agri-SSPs are titled (1) Agriculture on sustainable paths, (2) Agriculture on established paths, (3) Agriculture on separated paths, (4) Agriculture on unequal paths, and (5) Agriculture on high-tech paths. They describe alternative plausible qualitative evolutions of multiple drivers of particular importance and high uncertainty for European agriculture and food systems. The added value of the protocol-based storyline development process lies in the conceptual and methodological transparency and rigor; the stakeholder driven selection of the storyline elements; and consistency checks within and between the storylines. Compared to the global SSPs, the five Eur-Agri-SSPs provide rich thematic and regional details and are thus a solid basis for integrated assessments of agriculture and food systems and their response to future socio-economic and environmental changes.

A protocol to develop Shared Socio-economic Pathways for European agriculture.

Moving towards a more sustainable future requires concerted actions, particularly in the context of global climate change. Integrated assessments of agricultural systems (IAAS) are considered valuable tools to provide sound information for policy and decision-making. IAAS use storylines to define socio-economic and environmental framework assumptions. While a set of qualitative global storylines, known as the Shared Socio-economic Pathways (SSPs), is available to inform integrated assessments at large scales, their spatial resolution and scope is insufficient for regional studies in agriculture. We present a protocol to operationalize the development of Shared Socio-economic Pathways for European agriculture - Eur-Agri-SSPs - to support IAAS. The proposed design of the storyline development process is based on six quality criteria: plausibility, vertical and horizontal consistency, salience, legitimacy, richness and creativity. Trade-offs between these criteria may occur. The process is science-driven and iterative to enhance plausibility and horizontal consistency. A nested approach is suggested to link storylines across scales while maintaining vertical consistency. Plausibility, legitimacy, salience, richness and creativity shall be stimulated in a participatory and interdisciplinary storyline development process. The quality criteria and process design requirements are combined in the protocol to increase conceptual and methodological transparency. The protocol specifies nine working steps. For each step, suitable methods are proposed and the intended level and format of stakeholder engagement are discussed. A key methodological challenge is to link global SSPs with regional perspectives provided by the stakeholders, while maintaining vertical consistency and stakeholder buy-in. We conclude that the protocol facilitates systematic development and evaluation of storylines, which can be transferred to other regions, sectors and scales and supports inter-comparisons of IAAS.

Modelling crop land use change derived from influencing factors selected and ranked by farmers in North temperate agricultural regions.

To develop meaningful land use scenarios, drivers that affect changes in the landscape are required. In this study, driving factors that influence farmers to change crops on their farm were determined. A questionnaire was administered to four independent groups of farmers who identified and ranked influencing factors pertaining to their choices of crops. The farmers were located in two mid-latitude agricultural watersheds (in Germany and Canada). The ranked influencing factors were used to develop a "farmer driven" scenario to 2040 in both watersheds. Results showed that the most important influencing factors for farmers to change crops were the "economic return of the crop" and "market factors". Yet, when the drivers of crop land use change were grouped into two categories of "financial" and "indirectly-related financial" factors, the "financial" factors made up approximately half of the influencing factors. For some responses, the "indirectly-related financial" factors (i.e. "access to farm equipment", the "farm experience", and "climate") ranked higher than or just as high as the financial factors. Overall, in the four farmer groups the differences between the rankings of the influencing factors were minor, indicating that drivers may be transferable between farms if the farmers are full-time and the farming regions have comparable growing seasons, access to markets, similar technology, and government programs for farm income. In addition to the "farmer driven" scenario, a "policy driven" scenario was derived for each watershed based only on available information on the financial incentives provided to farmers (i.e. agricultural subsidies, income support, crop insurance). The influencing factors ranked by the farmers provided in-depth information that was not captured by the "policy driven" scenario and contributed to improving predictions for crop land use development. This straight-forward method to rank qualitative data provided by farmers can easily be replicated in other watersheds to improve environmental impact modelling.