Why are decisions in flood disaster management so poorly supported by information from flood models?

Flood simulation models can provide practitioners of Flood Disaster Management with sophisticated estimates of floods. Despite the advantages that flood simulation modeling may provide, experiences have proven that these models are of limited use. Until now, this problem has mainly been investigated by evaluations of which information is demanded by decision-makers versus what models can actually offer. However, the goal of this study is to investigate how model information is exchanged among participants in flood disaster organizations and how this exchange affects the use of modeling information. Our findings indicate that the extent to which a model is useful not only depends on the type and quality of its output, but also on how fast and flexible a model can be. In addition, methods of model use are required that support a fast exchange of model information between participants in the flood disaster organization

Psychometric evaluation of blood disaster management questionnaire-(floodDMQ-BM©) : confirmatory factor analysis and item response theory analysis

Background Flood disaster is the commonest natural disaster with a huge impact on health care services in Malaysia. Therefore, the FloodDMQ-BM© questionnaire is developed as a tool to assess the knowledge, attitude, and practice of health care providers regarding patient management during a flood disaster. This work aimed to further validate the FloodDMQ-BM© questionnaire by using Confirmatory Factor Analysis (CFA) and Item Response Theory (IRT) in order to confirm its validity in assessing the knowledge, attitude, and practice of health care providers regarding patient management during a flood disaster. Materials and Methods This observational cross-sectional study involved health care workers in the Emergency Department (ED) of Hospital Universiti Sains Malaysia (HUSM), Hospital Raja Perempuan Zainab II (HRPZ2), and Hospital Kuala Krai (HKK). The completed FloodDMQ-BM© questionnaire was analysed by using CFA and IRT to establish its validity and reliability. Result A total of 209 respondents participated in this study, yielding an 84% response rate. CFA method subjected on the attitude and practice components resulted in good factor loadings (>0.5) in nearly all items and good model fit indices values (CFI = 0.96-0.98, TLI = 0.95- 0.96, SRMR = 0.04-0.05, RMSEA = 0.07). Meanwhile, IRT analysis on the knowledge section showed a good two-way marginal fit based on S-X2, and a good model fit with RMSEA of 0.08. The items had good standardised loadings (>0.3) and marginal reliability of 0.651. Conclusion Our results confirmed that the FloodDMQ-BM© questionnaire displayed valid and reliable psychometric properties

Analysis of the performance of a hybrid CPU/GPU 1D2D coupled model for real flood cases

Coupled 1D2D models emerged as an efficient solution for a two-dimensional (2D) representation of the floodplain combined with a fast one-dimensional (1D) schematization of the main channel. At the same time, high-performance computing (HPC) has appeared as an efficient tool for model acceleration. In this work, a previously validated 1D2D Central Processing Unit (CPU) model is combined with an HPC technique for fast and accurate flood simulation. Due to the speed of 1D schemes, a hybrid CPU/GPU model that runs the 1D main channel on CPU and accelerates the 2D floodplain with a Graphics Processing Unit (GPU) is presented. Since the data transfer between sub-domains and devices (CPU/GPU) may be the main potential drawback of this architecture, the test cases are selected to carry out a careful time analysis. The results reveal the speed-up dependency on the 2D mesh, the event to be solved and the 1D discretization of the main channel. Additionally, special attention must be paid to the time step size computation shared between sub-models. In spite of the use of a hybrid CPU/GPU implementation, high speed-ups are accomplished in some cases

Estimation of uncertainty in flood forecasts - a comparison of methods

The scientific literature has many methods for estimating uncertainty, however, there is a lack of information about the characteristics, merits and limitations of the individual methods, particularly for making decisions in practice. This paper provides an overview of the different uncertainty methods for flood forecasting that are reported in literature, concentrating on two established approaches defined as the ensemble and the statistical approach. Owing to the variety of flood forecasting and warning systems in operation, the question ‘which uncertainty method is most suitable for which application’ is difficult to answer readily. The paper aims to assist practitioners in understanding how to match an uncertainty quantification method to their particular application using two flood forecasting system case studies in Belgium and Canada. These two specific applications of uncertainty estimation from the literature are compared, illustrating statistical and ensemble methods, and indicating the information and output that these two types of methods offer. The advantages, disadvantages and application of the two different types of method are identified. Although there is no one ‘best’ uncertainty method to fit all forecasting systems, this review helps to explain the current commonly used methods from the available literature for the non-specialist

Desastres naturais no Brasil e no mundo: uma análise holística com ênfase nos impactos dos eventos hidrológicos e meteorológicos/Natural disasters in Brazil and over the world: An analysis emphasizing hydrological and meteorological events

 Este texto analisa a evolução dos desastres naturais atribuindo ênfase aos impactos do eventos de origem hidrológica e meteorológica no mundo e no Brasil. A análise dedica especial atenção a influência dos fatores demográficos na ocorrência de desastres naturais. A abordagem de pesquisa adotada baseia-se numa detalhada revisão bibliográfica dos trabalhos publicados em periódicos e relatórios de organizações internacionais e centros de pesquisa, na interpretação das tendências referentes à estatística dos desastres e na comparação inter-regional  e interanual da situação dos desastres em termos da frequência de ocorrência, severidade (vítimas humanas e danos materiais) e instrumentos preventivos. Os resultados demonstram que a frequência e intensidade dos desastres têm vindo a agravar-se e que os desastres hidrológicos (inundações) são os mais preocupantes no que concernce à vitimas humanas e danos materiais. Concluiu-se que a intensa expansão de áreas urbanas acompanhada do aumento da densidade demográfica e ocupação de áreas de risco contribuem para ocorrência de desastres no Brasil e no mundo

Proposição de diretrizes para dimensionamento de estruturas de dissipação de energia do escoamento: contribuição para mitigação de danos e perdas em regiões de geomorfologia complexa sujeitas a desastres hidrológicosGuidelines to design energy dissipation structures: contribution to mitigate damages and losses in complex geomorphology regions subjected to hydrological disaster

As estruturas de dissipação de energia do escoamento (EDE) são fundamentais para prevenir a erosão e a degradação ambiental, bem como a ruptura de infraestruturas na sequência de eventos hidrológicos extremos. Este trabalho analisa diferentes soluções para dissipação de energia do escoamento, assim como os respectivos critérios de dimensionamento das estruturas, geralmente, localizadas a jusante de bueiros (culverts) que atravessam as vias de comunicação (e.g. estrada, caminho de ferro), em alguns trechos de canais (naturais ou artificiais), nas encostas íngremes, nos sistemas de rega e nos vertedores de barragem. Realizou-se uma profunda revisão bibliográfica para sintetizar o conhecimento disperso e construir um procedimento integrado – baseado nas características do escoamento e do meio ambiente – para avaliar a necessidade, selecionar e dimensionar EDE. Foram estabelecidos os domínios de aplicação das estruturas mais adequadas para diferentes condições de escoamento e características biofísicas do território (em termos da geomorfologia), atribuindo ênfase às situações de orografia complexa. Em situações de acentuada declividade das encostas e dos canais do escoamento, a solução mais adequada é aquela que evita (ou atenua significativamente) a ocorrência do escoamento em regime supercrítico. Nesse tipo de solução, incluem-se as estruturas de queda abrupta e em degraus, pois estas permitem regular a declividade, de modo a evitar trechos de aceleração além de dissiparem a energia do escoamento ao longo das quedas sucessivas. Este trabalho constitui uma ferramenta útil para os organismos públicos reguladores com responsabilidade na área de aprovação e fiscalização de projetos de infraestruturas, ordenamento do território e planejamento ambiental, assim como para os projetistas vocacionados para concepção e execução de projetos de infraestruturas de engenharias civil, ambiental e agronômica.Abstract Energy dissipation structures are essential to prevent erosion and environmental degradation as well as the breakdown of infrastructure during extreme hydrological events. This work analyzes the different solutions for the flow energy dissipation, as well as their criteria for design of structures, usually located downstream of culverts (culverts) crossing the communication routes (e.g. road, railway)in some channel(natural or artificial) sections in irrigation systems and dam spillways. Starting from the definition of the applicability of energy dissipaters (EDE), and design criteria, we propose a procedure that evaluates the need for implementation of EDE, select the appropriate type of structure, and design the structure. The research led to the description of the fields of application of the most appropriate structures for different flow and land (in terms of geomorphology) conditions giving emphasis on complex terrain situations. The combined assessment of different structures analyzed with geomorphological conditions of the regions, shows that in situations of steep slopes of the hill slopes and outlets the appropriate solution is the one that avoids (or reduces significantly) the occurrence of supercritical flow. This type of solution includes the drop structures and stepped spillways as they allow the regularization of channel slope avoiding acceleration and dissipate the flow energy. This work serves essentially as a useful tool for public regulators with responsibility in the area of approval and supervision of infrastructure projects, land use and environmental planning as well as for practitioners on the area of civil engineering, environmental and Agronomic projects

Extending delone and mclean success model with diffusion of innovation theory factors for flood early warning and response system success model : a case study at pahang civil defence department

In terms of population affected, the region involved, frequency, social-economic damage, and flood period, floods are a major natural disaster in Malaysia. That emphasizes the value of systematic and effective flood control, which necessitates government agencies improving their efficiency through technical advancement. The Flood Early Warning and Response System (FEWRS) success model is critical to prevent loss of life and property. It ensures that all stakeholders have the correct information and have the appropriate actions and response information. It should have some successful accessibility functionality and success elements of its strategic knowledge access and show, but current FEWRS success model lacks and often do not adequately have information on flood hazards to minimize their effects at a local level and save the lives of the people. For researchers, practitioners, and managers, determining the success of an Information System (IS) remains a significant concern. Therefore, the research objective of this study is to identify the success factors that affect the implementation of enhance FEWRS success model, to deploy the enhanced FEWRS success model. Moreover, to validate the enhanced FEWRS success model using the statistical analysis methods. This research focuses on two theoretical frameworks: DeLone and McLean (DLML) IS success model and Diffusion of Innovation Theory (DOI). These two theories have been found the most appropriate to be adopted for the FEWRS success model. They are merged to understand and explore the successful contingent related to IS implementation. DLML and DOI are among the most utilized theories applied in research relating to systems, technology, and information use. DOI theory states that the organization’s innovation and organizational characteristics and the environment in which it operates can influence the diffusion and success of Information Technology (IT) initiatives. The enhanced FEWRS success model was validated through the development of the enhanced FEWRS model and the use of statistical analysis methods. To validate the FEWRS success model, this study employs the Partial Least Squares-Structural Equation Modelling (PLS-SEM). Data were collected through a questionnaire survey administered to 141 employees from Kuantan Civil Defence Department (CDD) in Pahang state, Malaysia. Preliminary survey had been done before going further into the study to show the importance of the research. The results suggest that information quality, system quality, service quality, and compatibility have a positive effect on user satisfaction of the enhanced FEWRS success model with (P-value = 2.359, 0.204, 0218, 0.445, and 0354. These factors have a strong significant relationship with the user’s satisfaction. However, the relative advantage has a positive effect on user satisfaction but was not supported with (P-value = 0.015). On the other hand, complexity has a negative effect on user satisfaction of the FEWRS with (P-value = - 0.114). Therefore, complexity was found to have a significant relationship with user satisfaction. Furthermore, user satisfaction has positively affected the success of the FEWRS. In the light of the FEWRS success model presence in the flood disaster and other natural disasters, the study findings will act as a guide for strengthening government policy and the public sector. Moreover, the results have a significant contribution by validating and extending the DLML with DOI factors and providing various implications to the research, theory, and practice