Prediction of storm transfers and annual loads with data-based mechanistic models using high-frequency data

Excess nutrients in surface waters, such as phosphorus (P) from agriculture, result in poor water quality, with adverse effects on ecological health and costs for remediation. However, understanding and prediction of P transfers in catchments have been limited by inadequate data and over-parameterised models with high uncertainty. We show that, with high temporal resolution data, we are able to identify simple dynamic models that capture the P load dynamics in three contrasting agricultural catchments in the UK. For a flashy catchment, a linear, second-order (two pathways) model for discharge gave high simulation efficiencies for short-term storm sequences and was useful in highlighting uncertainties in out-of-bank flows. A model with nonlinear rainfall input was appropriate for predicting seasonal or annual cumulative P loads where antecedent conditions affected the catchment response. For second-order models, the time constant for the fast pathway varied between 2 and 15 h for all three catchments and for both discharge and P, confirming that high temporal resolution data are necessary to capture the dynamic responses in small catchments (10–50 km2/. The models led to a better understanding of the dominant nutrient transfer modes, which will be helpful in determining phosphorus transfers following changes in precipitation patterns in the future

Determining the effect of drying time on phosphorus solubilization from three agricultural soils under climate change scenarios

Climate projections for the future indicate that the United Kingdom will experience hotter, drier summers and warmer, wetter winters, bringing longer dry periods followed by rewetting. This will result in changes in phosphorus (P) mobilization patterns that will influence the transfer of P from land to water. We tested the hypothesis that changes in the future patterns of drying–rewetting will affect the amount of soluble reactive phosphorus (SRP) solubilized from soil. Estimations of dry period characteristics (duration and temperature) under current and predicted climate were determined using data from the UK Climate Projections (UKCP09) Weather Generator tool. Three soils (sieved 25°C are predicted in some places and dry periods of 30 to 90 d extremes are predicted. Combining the frequency of projected dry periods with the SRP concentration in leachate suggests that this may result overall in increased mobilization of P; however, critical breakpoints of 6.9 to 14.5 d dry occur wherein up to 28% more SRP can be solubilized following a rapid rewetting event. The precise cause of this increase could not be identified and warrants further investigation as the process is not currently included in P transfer models

UK Phosphorus Transformation Strategy: Towards a circular UK food system

This report sets out the UK’s first comprehensive national phosphorus transformation strategy, based on extensive stakeholder consultation across the UK food system, in addition to economic modelling and biophysical analyses. The UK’s food system is in transition, driven in part by major changes to agricultural policy. It is also under pressure from climate change, land use change, Brexit uncertainties, and unforeseen shocks like COVID-19. However one critical challenge that has not been sufficiently addressed is the secure supply and sustainable use of phosphorus. Phosphorus is a lynchpin of the food system and has no substitute. Yet its mismanagement has led to serious risks of compromising future food and water security in the UK and globally. This Strategy forms part of a larger, 3-year, UKRI-funded research effort, the RePhoKUs project

Factive Scientific Understanding Without Accurate Representation

This paper analyzes two ways idealized biological models produce factive scientific understanding. I then argue that models can provide factive scientific understanding of a phenomenon without providing an accurate representation of the (difference-making) features of their real-world target system(s). My analysis of these cases also suggests that the debate over scientific realism needs to investigate the factive scientific understanding produced by scientists’ use of idealized models rather than the accuracy of scientific models themselves

Pay-off scarcity causes evolution of risk-aversion and extreme altruism

All organisms descend from populations with limited resources, so it is clear why evolution should select strategies that win resources at the expense of competitors. Less obvious is how altruistic behaviours evolve, whereby an individual helps others despite expense to itself. Modelling simple agents using evolutionary game theory, it is shown that steady states of extreme altruism can evolve when pay-offs are very rare compared with death. In these states, agents give away most of their wealth. A new theorem for general evolutionary models shows that, when pay-offs are rare, evolution no longer selects strategies to maximize income (average pay-off), but to minimize the risk of missing-out entirely on a rare resource. Principles revealed by the model are widely applicable, where the game represents rare life-changing events: disasters or gluts

Selection in a Complex World: Deriving Causality from Stable Equilibrium

It is an ongoing controversy whether natural selection is a cause of population change, or a mere statistical description of how individual births and deaths accumulate. In this paper I restate the problem in terms of the reference class problem, and propose how the structure of stable equilibrium can provide a solution in continuity with biological practice. Insofar natural selection can be understood as a tendency towards equilibrium, key statisticalist criticisms are avoided. Further, in a modification of the Newtonian-force analogy, it can be suggested that a better metaphor for natural selection is that of an emergent force, similar in nature to entropic forces: with magnitude and direction, but lacking a spatiotemporal origin or point of application.status: publishe

Interdisciplinary Collaboration in the Virtual Design Studio Design Studio

Drastic changes in technology and economics currently impact common working structures. Moreover, a fundamental move of western societies from industrial and service oriented societies to information oriented societies can be observed. Like others, the AEC industry is also exposed to the challenge of these fundamental changes, not only regarding an ever growing stock of information on building components and materials, but also because of new methods of collaboration to be applied by all participants. As a result, integrating domain specific knowledge into the design process and conversely, conveying design intentions to domain experts, is meaningful in a constantly growing scale. Utilising advanced technology, a twofold approach in research and education, undertaken at the Institut für Industrielle Bauproduktion (ifib), University of Karlsruhe, is the basis of efforts to create and develop integrating methods of collaboration into the design and planning process. In addition, the integration of AEC practitioners (investors, users, designers, engineers) in the education process provides both drastic changes in the fields of design and construction education of students and a promising approach for life long learning. The focus of this paper is to present the current state of work and to report on experiences gathered during several Virtual Design Studios (VDS) in which multi-disciplinary participants from various Universities and backgrounds were involved. Platforms for the activities are World Wide Web based applications as well as animations, VR, CAD and video conferencing