Assessing the reliability of probabilistic flood inundation model predictions

An ability to quantify the reliability of probabilistic flood inundation predictions is a requirement not only for guiding model development but also for their successful application. Probabilistic flood inundation predictions are usually produced by choosing a method of weighting the model parameter space, but previous study suggests that this choice leads to clear differences in inundation probabilities. This study aims to address the evaluation of the reliability of these probabilistic predictions. However, a lack of an adequate number of observations of flood inundation for a catchment limits the application of conventional methods of evaluating predictive reliability. Consequently, attempts have been made to assess the reliability of probabilistic predictions using multiple observations from a single flood event. Here, a LISFLOOD-FP hydraulic model of an extreme (>1 in 1000 years) flood event in Cockermouth, UK, is constructed and calibrated using multiple performance measures from both peak flood wrack mark data and aerial photography captured post-peak. These measures are used in weighting the parameter space to produce multiple probabilistic predictions for the event. Two methods of assessing the reliability of these probabilistic predictions using limited observations are utilized; an existing method assessing the binary pattern of flooding, and a method developed in this paper to assess predictions of water surface elevation. This study finds that the water surface elevation method has both a better diagnostic and discriminatory ability, but this result is likely to be sensitive to the unknown uncertainties in the upstream boundary condition

L'effet de compensation morale ou comment les 'bonnes actions' peuvent aboutir à une situation indésirable

Des recherches récentes arguent qu’une « bonne action » pourrait contribuer à « désinhiber » l’individu en lui permettant d’entreprendre des actions « moins souhaitables » par la suite. Cet effet de compensation morale reste un domaine peu étudié, en dépit des conséquences potentielles considérables sur l’efficacité des politiques publiques. L’objectif de notre contribution est de définir et de caractériser cet effet tout en soulignant les risques d’effets pervers associés. Nous utilisons à cet effet des études et des exemples tirés de divers domaines, comme la consommation alimentaire ou les comportements prosociaux, et identifions des pistes de recherche visant à mieux comprendre les conséquences directes et indirectes de cet effet, tout en mentionnant quelques stratégies envisageables afin d’atténuer ce biais.

Probabilistic wind power forecasts with an inverse power curve transformation and censored regression

Forecasting wind power is an important part of a successful integration of wind power into the power grid. Forecasts with lead times longer than 6 h are generally made by using statistical methods to post-process forecasts from numerical weather prediction systems. Two major problems that complicate this approach are the non-linear relationship between wind speed and power production and the limited range of power production between zero and nominal power of the turbine. In practice, these problems are often tackled by using non-linear non-parametric regression models. However, such an approach ignores valuable and readily available information: the power curve of the turbine's manufacturer. Much of the non-linearity can be directly accounted for by transforming the observed power production into wind speed via the inverse power curve so that simpler linear regression models can be used. Furthermore, the fact that the transformed power production has a limited range can be taken care of by employing censored regression models. In this study, we evaluate quantile forecasts from a range of methods: (i) using parametric and non-parametric models, (ii) with and without the proposed inverse power curve transformation and (iii) with and without censoring. The results show that with our inverse (power-to-wind) transformation, simpler linear regression models with censoring perform equally or better than non-linear models with or without the frequently used wind-to-power transformation.

A global empirical system for probabilistic seasonal climate prediction

Preparing for episodes with risks of anomalous weather a month to a year ahead is an important challenge for governments, non-governmental organisations, and private companies and is dependent on the availability of reliable forecasts. The majority of operational seasonal forecasts are made using process-based dynamical models, which are complex, computationally challenging and prone to biases. Empirical forecast approaches built on statistical models to represent physical processes offer an alternative to dynamical systems and can provide either a benchmark for comparison or independent supplementary forecasts. Here, we present a simple empirical system based on multiple linear regression for producing probabilistic forecasts of seasonal surface air temperature and precipitation across the globe. The global CO2-equivalent concentration is taken as the primary predictor; subsequent predictors, including large-scale modes of variability in the climate system and local-scale information, are selected on the basis of their physical relationship with the predictand. The focus given to the climate change signal as a source of skill and the probabilistic nature of the forecasts produced constitute a novel approach to global empirical prediction. Hindcasts for the period 1961–2013 are validated against observations using deterministic (correlation of seasonal means) and probabilistic (continuous rank probability skill scores) metrics. Good skill is found in many regions, particularly for surface air temperature and most notably in much of Europe during the spring and summer seasons. For precipitation, skill is generally limited to regions with known El Niño–Southern Oscillation (ENSO) teleconnections. The system is used in a quasi-operational framework to generate empirical seasonal forecasts on a monthly basis.

Data Assimilation and Inverse Methods in Terms of a Probabilistic Formulation

The weak-constraint inverse for nonlinear dynamical models is discussed and derived in terms of a probabilistic formulation. The well-known result that for Gaussian error statistics the minimum of the weak-constraint inverse is equal to the maximum-likelihood estimate is rederived. Then several methods based on ensemble statistics that can be used to find the smoother (as opposed to the filter) solution are introduced and compared to traditional methods. A strong point of the new methods is that they avoid the integration of adjoint equations, which is a complex task for real oceanographic or atmospheric applications. they also avoid iterative searches in a Hilbert space, and error estimates can be obtained without much additional computational effort. the feasibility of the new methods is illustrated in a two-layer quasigeostrophic model.

Willingness-to-pay for a probabilistic flood forecast: a risk-based decision-making game

Probabilistic hydro-meteorological forecasts have over the last decades been used more frequently to communicate forecastuncertainty. This uncertainty is twofold, as it constitutes both an added value and a challenge for the forecaster and the user of the forecasts. Many authors have demonstrated the added (economic) value of probabilistic over deterministic forecasts across the water sector (e.g. flood protection, hydroelectric power management and navigation). However, the richness of the information is also a source of challenges for operational uses, due partially to the difficulty to transform the probability of occurrence of an event into a binary decision. This paper presents the results of a risk-based decision-making game on the topic of flood protection mitigation, called “How much are you prepared to pay for a forecast?”. The game was played at several workshops in 2015, which were attended by operational forecasters and academics working in the field of hydrometeorology. The aim of this game was to better understand the role of probabilistic forecasts in decision-making processes and their perceived value by decision-makers. Based on the participants’ willingness-to-pay for a forecast, the results of the game show that the value (or the usefulness) of a forecast depends on several factors, including the way users perceive the quality of their forecasts and link it to the perception of their own performances as decision-makers.

An extinction-survival-type phase transition in the probabilistic cellular automaton p182-q200

We investigate the critical behaviour of a probabilistic mixture of cellular automata (CA) rules 182 and 200 (in Wolfram`s enumeration scheme) by mean-field analysis and Monte Carlo simulations. We found that as we switch off one CA and switch on the other by the variation of the single parameter of the model, the probabilistic CA (PCA) goes through an extinction-survival-type phase transition, and the numerical data indicate that it belongs to the directed percolation universality class of critical behaviour. The PCA displays a characteristic stationary density profile and a slow, diffusive dynamics close to the pure CA 200 point that we discuss briefly. Remarks on an interesting related stochastic lattice gas are addressed in the conclusions.

Intervjustudie av oskyddade trafikanters situation på 13 m mötesseparerad landsväg

I kölvattnet av Nollvisionen uppstår problem för oskyddade trafikanter. Vid mittseparering av 13-metersvägar blir utrymmet för dessa trafikantgrupper otillräckligt och nya lösningar måste till. Detta examensarbete syftar till att förbättra framkomligheten och trafiksäkerheten för oskyddade trafikanter på s k MLV (Mötesseparerad LandsVäg). Målet med examensarbetet har varit att inventera problem, identifiera förbättringsområden, finna bra lösningar samt att beräkna vilka kostnader som dessa lösningar orsakar.Som ett resultat av arbetet har framkommit att det saknas en nationell samstämmighet i synen på hur oskyddade trafikanter på MLV, skall behandlas. Vidare existerar det en stor fokusering i centrala direktiv, kanske mest inofficiella, på bilisters och transportörers behov vid utformningen av MLV. Som en konsekvens av detta har de oskyddade trafikanterna blivit undanträngda, både bildligt och fysiskt talat, från dessa vägtyper och därmed begränsas deras förflyttnings-möjligheter. Ytterligare resultat är att det behövs mer utredning kring hänvisning för de oskyddade trafikanterna på MLV, detta för att i möjligaste mån separera trafikantgrupperna.I arbetet har också utförts en kostnadsberäkning av en GCM-lösning (GCM står för Gång, Cykel och Moped) på en vägsträcka, riksväg 80 mellan Falun och Hofors. Kostnaden blev 1,1 - 2,2 mn kr, vilket motsvarar en projektfördyring med 4,4 - 11 %, beroende på alternativ. De viktigaste slutsatserna i arbetet är att man bör anstränga sig till det yttersta för att erbjuda ett alternativ till en MLV, och att man då också måste förbättra skyltningen, för att undvika att oskyddade trafikanter irrar sig in på MLV:n, trots acceptabla alternativvägar. För detta har ett förslag till ett nytt vägmärke framtagits, Alternativ GCM-väg längs MLV, se Bilaga 5.

En högpresterande elevs situation i skolan : En jämförande studie mellan pedagoger och högpresterande elever

Syftet med examensarbetet är att undersöka vad pedagoger har för attityder till högpresterande elever och hur de upplever att ha högpresterande elever i skolan både ur ett pedagogiskt perspektiv samt ett socialt perspektiv. Hur de anpassar sin undervisning för dessa elevers behov och vilka metoder de använder sig av i sin undervisning. Vidare har uppsatsen som mål är att göra en jämförelse mellan detta och hur högpresterande elever själva, i årskurserna fyra till sex, upplever sin situation i skolan idag. Att hitta likheter och skillnader mellan forskning och aktörer i skolans verksamhet. För att få reda på detta har vi valt att genomföra djupintervjuer med pedagoger och en enkätundersökning med högpresterande elever. Utifrån rådande forskning har vi sökt information om inlärningsstilar, intelligens, individualisering och resursfördelning. Vi har dragit följande slutsatser; att vissa resultat pekar i motsatt riktning mot vad tidigare forskning och tidigare undersökningar kommit fram till. Tidigare forskningen menar att resurserna fördelas ojämnt och att de högpresterande eleverna inte får alls samma mängd som sina klasskamrater. De pedagoger vi intervjuat menar däremot att eleverna visst får sin resursdel men i en annan form, nämligen i förberedelserna till undervisningen då dessa elever i regel är mer självgående och klarar av större och mer långsiktiga mål. Vidare pekar vår undersökning på att det finns en tillräckligt hög procent av elever för att enligt oss ses som oroväckande hög, som upplever sig orättvist behandlade i skolan. Avslutningsvis så ställer vi oss efter denna undersökning frågande till hur pedagoger egentligen ser på ett individualiserat arbetssätt för en högpresterande elev.

Pre-diabetes i fokus : Patienters förståelse och upplevelse av pre-diabetes i mötet med personer i samma situation

Syfte: Att beskriva personers upplever att få pre-diabetes som en del av livet. Metod: Kvalitativ design. Studien genomfördes med fokusgrupper bestående av personer med pre-diabetes. Tre olika grupper med totalt 12 personer ingick i studien. Resultat: Ur diskussionerna kunde tre olika kategorier urskiljas. Pre-diabetes som en del av livet, egen erfarenhet och kunskap om tillståndet samt behov av information och stöd för ökad kunskap om livsstilsförändringar. Pre-diabetes var för de flesta studiedeltagare ett okänt begrepp. Känslor som osäkerhet och rädsla för tillståndet, samt för eventuell utveckling till manifest diabetes var vanligt. Det ansågs värdefullt att få besked i tidigt skede om förhöjda blodsockervärden, eftersom individen då hade möjlighet att påverka sin livsstil och förebygga annan sjukdom. Alla deltagare önskade mer kunskap och stöd kring pre-diabetes och livsstilsåtgärder. Respondenterna beskrev besvikelse över vårdpersonalens bemötande i samband med beskedet om förhöjda blodsockervärden. Informationen ansågs vara för knapphändig vilket gav uppfattning om att tillståndet inte var något att bry sig om. Konklusion: Respondenterna ville i största möjligaste utsträckning förhindra utvecklingen av T2DM genom egenvårdsinsater i form livsstilsförändringar. För att lyckas med det uppgav studiedeltagarna behov av information om vad tillståndet pre-diabetes innebär. Personer som får pre-diabetes bör få saklig information, råd och stöd om tillståndet i samband med beskedet.

Audiovisuella samtidskonstens utövare : Intervjuer med audiovisuella utövare om deras situation och förutsättningar

Uppsatsen behandlar audiovisuella utövares uppfattning om sig själva i det audiovisuella området med avstamp i sociologisk teori och etnografisk metod. Ett antal intervjuer utfördes med aktuella utövare i syftet att bidra till kunskap om hur det audiovisuella området upplevs av informanterna, samt hur deras beskrivningar relaterar till närliggande områden. Utvalda citat från de transkriberade intervjuerna uppvisas i resultatavsnittet i idealiserande kategorier. Teman som framkommer tydligt är tituleringsproblematiken, beskrivning av den oförberedda besökaren, strävan efter balans mellan sinnesintryck i utförandet och kunskapsbredd i verktygen. Slutligen reflekterar författaren över dessa resultat i diskussionsavsnittet.

Facilitation of learning in specialist nursing training in the PICU : the supervisors´ concerns in the learning situation

With the aim to unfold nurses’ concerns of the supervision of the student in the clinical caring situation of the vulnerable child, clinical nurses situated supervision of postgraduate nursing students in the Pediatric Intensive Care Unit (PICU) are explored. A qualitative approach, interpretive phenomenology, with participant observations and narrative interviews, was used. Two qualitative variations of patterns of meaning for the nurses’ clinical facilitation were disclosed in this study. Learning by doing theme supports the students learning by doing through performing skills and embracing routines. The reflecting theme supports thinking and awareness of the situation. As the supervisor often serves as a role model for the student this might have an immediate impact on how the student applies nursing care in the beginning of his or her career. If the clinical supervisor narrows the perspective and hinders room for learning the student will bring less knowledge from the clinical education than expected, which might result in reduced nursing quality.

Pregnancy-related low back pain and pelvic girdle pain approximately 14 months after pregnancy : pain status, self-rated health and family situation

Background: Pelvic girdle pain (PGP) in pregnancy is distinct from pregnancy-related low back pain (PLBP). However, women with combined PLBP and PGP report more serious consequences in terms of health and function. PGP has been estimated to affect about half of pregnant women, where 25% experience serious pain and 8% experience severe disability. To date there are relatively few studies regarding persistent PLBP/PGP postpartum of more than 3 months, thus the main objective was to identify the prevalence of persistent PLBP and PGP as well as the differences over time in regard to pain status, self-rated health (SRH) and family situation at 12 months postpartum. Methods: The study is a 12 month follow-up of a cohort of pregnant women developing PLBP and PGP during pregnancy, and who experienced persistent pain at 6 month follow-up after pregnancy. Women reporting PLBP/PGP (n = 639) during pregnancy were followed up with a second questionnaire at approximately six month after delivery. Women reporting recurrent or persistent LBP/PGP at the second questionnaire (n = 200) were sent a third questionnaire at 12 month postpartum. Results: A total of 176 women responded to the questionnaire. Thirty-four women (19.3%) reported remission of LBP/PGP, whereas 65.3% (n = 115) and 15.3% (n = 27), reported recurrent LBP/PGP or continuous LBP/PGP, respectively. The time between base line and the 12 months follow-up was in actuality 14 months. Women with previous LBP before pregnancy had an increased odds ratio (OR) of reporting 'recurrent pain' (OR = 2.47) or 'continuous pain' (OR = 3.35) postpartum compared to women who reported 'no pain' at the follow-up. Women with 'continuous pain' reported statistically significant higher level of pain at all measure points (0, 6 and 12 months postpartum). Non-responders were found to report a statistically significant less positive scoring regarding relationship satisfaction compared to responders. Conclusions: The results from this study demonstrate that persistent PLBP/PGP is a major individual and public health issue among women 14 months postpartum, negatively affecting their self-reported health. However, the perceived relationship satisfaction seems to be stable between the groups.

Making Energy Interventions more Effective : Situation, Interaction, and Precondition

A main purpose of this paper is to propose to policy makers, building professionals, and other non-social scientists a way to make energy interventions more culturally informed and, thereby, more effective. The case study on house purchasers gives an ample illustration of the richer results that can be achieved by paying attention to three aspects of energy efficiency initiatives: the contexts and situations of choice in each particular case, the interaction among relevant social actors, and the culture-specific preconditions for choice. Research on how purchasers of new pre-fabricated houses in Sweden choose their heating system show how such decisions tend to fall between two stools. Furthermore, the organizational structure of housing companies frames house purchasers' decision making. An important result is that energy saving or conversion measures must be promoted at an early stage amongst those who plan and construct buildings (rather than later amongst dwellers and energy end users).