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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Wood frame building response to rapid onset flooding

Becker, Andrea 11 1900 (has links)
Floods are considered to be among of the deadliest, costliest and most common natural disasters. Rapid onset, catastrophic floods inundate the shore quickly and manifest as deep water with high velocities. The deep water and high velocities caused by these floods inflict great pressures and forces on the built and natural environments and pose a threat to human safety. Recent disasters such as Hurricane Katrina in the Southern United States and the Sumatra tsunami in the Indian Ocean have revealed that communities at risk require improved preparations for these types of dangerous events. Current building codes, design practices and disaster planning methods account for potential earthquake and wind loads on simple wood frame buildings typical of North American residential construction, however, flood impacts have not been considered in the same level of depth. The objectives of this research are to develop a theoretical model that describes flood impacts on wood frame residential buildings and relates building response to physical flood properties such as depth and velocity. This thesis provides a brief synopsis of previous approaches used to describe building response to flooding. An overview of the major loads caused by rapid onset flooding, along with a description of the structural system utilized in wood design to resist these forces is provided. The failure mechanisms considered and the model logic are described and applied to assess the response of a typical Canadian wood frame home to flood conditions that might be experienced in a rapid onset flood event like a tsunami. Building response results are discussed along with recommendations for future analysis and applications.
2

Wood frame building response to rapid onset flooding

Becker, Andrea 11 1900 (has links)
Floods are considered to be among of the deadliest, costliest and most common natural disasters. Rapid onset, catastrophic floods inundate the shore quickly and manifest as deep water with high velocities. The deep water and high velocities caused by these floods inflict great pressures and forces on the built and natural environments and pose a threat to human safety. Recent disasters such as Hurricane Katrina in the Southern United States and the Sumatra tsunami in the Indian Ocean have revealed that communities at risk require improved preparations for these types of dangerous events. Current building codes, design practices and disaster planning methods account for potential earthquake and wind loads on simple wood frame buildings typical of North American residential construction, however, flood impacts have not been considered in the same level of depth. The objectives of this research are to develop a theoretical model that describes flood impacts on wood frame residential buildings and relates building response to physical flood properties such as depth and velocity. This thesis provides a brief synopsis of previous approaches used to describe building response to flooding. An overview of the major loads caused by rapid onset flooding, along with a description of the structural system utilized in wood design to resist these forces is provided. The failure mechanisms considered and the model logic are described and applied to assess the response of a typical Canadian wood frame home to flood conditions that might be experienced in a rapid onset flood event like a tsunami. Building response results are discussed along with recommendations for future analysis and applications.
3

Wood frame building response to rapid onset flooding

Becker, Andrea 11 1900 (has links)
Floods are considered to be among of the deadliest, costliest and most common natural disasters. Rapid onset, catastrophic floods inundate the shore quickly and manifest as deep water with high velocities. The deep water and high velocities caused by these floods inflict great pressures and forces on the built and natural environments and pose a threat to human safety. Recent disasters such as Hurricane Katrina in the Southern United States and the Sumatra tsunami in the Indian Ocean have revealed that communities at risk require improved preparations for these types of dangerous events. Current building codes, design practices and disaster planning methods account for potential earthquake and wind loads on simple wood frame buildings typical of North American residential construction, however, flood impacts have not been considered in the same level of depth. The objectives of this research are to develop a theoretical model that describes flood impacts on wood frame residential buildings and relates building response to physical flood properties such as depth and velocity. This thesis provides a brief synopsis of previous approaches used to describe building response to flooding. An overview of the major loads caused by rapid onset flooding, along with a description of the structural system utilized in wood design to resist these forces is provided. The failure mechanisms considered and the model logic are described and applied to assess the response of a typical Canadian wood frame home to flood conditions that might be experienced in a rapid onset flood event like a tsunami. Building response results are discussed along with recommendations for future analysis and applications. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
4

Predictability of hydrologic response at the plot and catchment scales: Role of initial conditions

Zehe, Erwin, Blöschl, Günter January 2004 (has links)
This paper examines the effect of uncertain initial soil moisture on hydrologic response at the plot scale (1 m2) and the catchment scale (3.6 km2) in the presence of threshold transitions between matrix and preferential flow. We adopt the concepts of microstates and macrostates from statistical mechanics. The microstates are the detailed patterns of initial soil moisture that are inherently unknown, while the macrostates are specified by the statistical distributions of initial soil moisture that can be derived from the measurements typically available in field experiments. We use a physically based model and ensure that it closely represents the processes in the Weiherbach catchment, Germany. We then use the model to generate hydrologic response to hypothetical irrigation events and rainfall events for multiple realizations of initial soil moisture microstates that are all consistent with the same macrostate. As the measures of uncertainty at the plot scale we use the coefficient of variation and the scaled range of simulated vertical bromide transport distances between realizations. At the catchment scale we use similar statistics derived from simulated flood peak discharges. The simulations indicate that at both scales the predictability depends on the average initial soil moisture state and is at a minimum around the soil moisture value where the transition from matrix to macropore flow occurs. The predictability increases with rainfall intensity. The predictability increases with scale with maximum absolute errors of 90 and 32% at the plot scale and the catchment scale, respectively. It is argued that even if we assume perfect knowledge on the processes, the level of detail with which one can measure the initial conditions along with the nonlinearity of the system will set limits to the repeatability of experiments and limits to the predictability of models at the plot and catchment scales.
5

Flowing Coast

Liu, Yanlin January 2022 (has links)
As a coastal city, the history and development of Helsinki are very much linked to its harbor. In particular, as the closest harbor to the city center, the South Port "Makasiiniranta" has largely served as the "gateway to the sea" of Helsinki. As the closest harbor to the city center, Makasiiniranta, in particular, has largely served as the "maritime gateway" to Helsinki, participating to a great extent in the daily life of Helsinki's residents and making a strong first impression on visitors. However, the function and form of the South Harbour have historically changed along with the values and needs of visitors, both residents and tourists, and this time is no exception.  The design of the harbor is based on this idea, which is divided into three levels: 1. the creation of a flood protection zone with different strategies based on the topography and different characteristics of the city; 2. the refinement and streamlining of the coastal flood protection architecture and landscape, which can exist in different scenarios with a variable form. To build climate-adapted spaces in coastal areas with their flexible forms to maximize the range of activities and functions of people at different water heights. 3. To embed functions in adaptive flood protection spaces to meet the needs of multiple groups.
6

Modeling geospatial events during flood disasters for response decision-making

Hubbard, Shane A. 01 December 2013 (has links)
A model that emphasizes possible alternative sequences of events that occur over time is presented in paper 1 (chapter 2) of this dissertation. Representing alternative or branching events captures additional semantics unrealized by linear or non-branching approaches. Two basic elements of branching, divergence and convergence are discussed. From these elements, many complex branching models can be built capturing a perspective of events that take place in the future or have occurred in the past. This produces likely sequences of events that a user may compare and analyze using spatial or temporal criteria. The branching events model is especially useful for spatiotemporal decision support systems, as decision-makers are able to identify alternative locations and times of events and, depending on the context, also identify regions of multiple possible events. Based on the formal model, a conceptual framework for a branching events model for flood disasters is presented. The framework has five parts, an event handler, a query engine, data assimilator, web interface, and event database. A branching events viewer application is presented illustrating a case study based on a flood response scenario. A spatiotemporal framework for building evacuation events is developed to forecast building content evacuation events and building vulnerabilities and is presented in paper 2 (chapter 3) of this dissertation. This work investigates the spatiotemporal properties required to trigger building evacuation events in the floodplain during a flood disaster. The spatial properties for building risks are based on topography, flood inundation, building location, building elevation, and road access to determine five categories of vulnerability, vulnerable basement, flooded basement, vulnerable first-floor, flooded first-floor, and road access. The amount of time needed to evacuate each building is determined by the number of vulnerable floors, the number of movers, the mover rate, and the weight of the contents to be moved. Based upon these properties, six possible evacuation profiles are created. Using this framework, a model designed to track the spatiotemporal patterns of building evacuation events is presented. The model is based upon flood forecast predictions that are linked with building properties to create a model that captures the spatiotemporal ordering of building vulnerabilities and building content evacuation events. Applicable to different communities at risk from flooding, the evacuation model is applied a historical flood for a university campus, demonstrating how the defined elements are used to derive a pattern of vulnerability and evacuation for a campus threatened by severe flooding. Paper 3 (Chapter 4) of this dissertation presents a modeling approach for representing event-based response risk. Surveys were sent to emergency managers in six states to determine the priorities of decision makers during the response phase of flood disasters. Based on these surveys, nine response events were determined to be the most important during a flood response, flooded roads, bridges closed, residential evacuations, residential flooding, commercial flooding, agricultural damage, power outage, sheltering, sandbagging. Survey participants were asked to complete pairwise comparisons of these nine events. An analytic hierarchy process analysis was completed to weight the response events for each decision-maker. A k-means clustering analysis was then completed to form 4 distinct profiles, mixed rural and urban, rural, urban, and high population - low population density. The average weights from each profile were calculated. The weights for each profile were then assigned to geospatial layers that identify the locations of these events. These layers are combined to form a map representing the event-based response risk for an area. The maps are then compared against the response events that actually occurred during a flood disaster in June 2008 in two communities.

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