The soaring number of natural hazards in recent years due largely to climate change has resulted in an even higher level of investment in flood protection structures. However, such investments tend to be made in the aftermath of disasters. Very little is known about the proactive planning of flood protection investments that account for uncertainties associated with flooding events. Understanding the uncertainties such as “when” to invest on these structures to achieve the most optimal cost-saving amount is outmost important. This study fills this large knowledge gap by developing an investment decision-making assessment framework that determines an optimal timing of flood protection investment options. It combines real options with a net present value analysis to examine managerial flexibility in various investment timing options. Historical data that contain information about river water discharges were leveraged as a random variable in the modeling framework because it may help investors better understand the probability of extreme events, and particularly, flooding uncertainties. A lattice model was then used to investigate potential alternatives of investment timing and to evaluate the benefits of delaying investments in each case. The efficacy of the proposed framework was demonstrated by an illustrative example of flood protection investment. The framework will be used to help better inform decision makers.

This Diploma Thesis deal with complex assessment of spring flood in 1909. In the theoretical part there are described types of floods. It focuses on rain-on-snow events together with melting of the snow and ice phenomena on streams. It also describe hydraulic models and especially in detail AquaLog model and its individual parts. The flood in 2006 which is compared to the event in 1909 is also described in more detail. In the historical archive there were found informations about flood in 1909 and because of them we know its area range. Next the flooding waves in Czech Republic were analized. The AquaLog model was used for basin of the river Sazava. Flooding waves were simulated for 9 stations in the whole basin using this model.

In this paper, I estimate the economic cost associated with flood risks in Sweden. A hedonic price model combined with a distance defined difference-in-differences method is used to estimate the marginal change in property prices due to new information regarding flood risks. The results reveal a robust effect on owner-occupied properties from predicted floods from the sea. The willingness to pay for increasing the distance to the predicted flooded area is estimated to be 0.187% per meter. A similar, though smaller (0.045% per meter) effect is found for all properties in proximity to floods from streams. The effects of the information regarding flood risks are limited to the year after the release. The results are especially important in a Swedish setting due to its numerous streams and lakes and extensive coastline. That the value of the risk of floods is limited to one year should be further investigated and considered when establishing policies regarding the information provided when a property is listed for sale.

Die Studie befasst sich mit den Möglichkeiten der ländlichen Entwicklung zur Unterstützung eines dezentralen Hochwasserschutzes. Sie basiert vorrangig auf der Beschaffung, Aufbereitung und Auswertung entsprechender Fachliteratur. Darüber hinaus wurden wasserbauliche- und landeskulturelle Maßnahmen, die im Rahmen der ländlichen Entwicklung in Sachsen realisiert wurden, hinsichtlich ihrer Eignung für den Hochwasserschutz bewertet. Aktuelle Forschungsergebnisse zu erosionsmindernden Bodenbearbeitungsverfahren, die in die Studie einflossen, wurden hausintern vom Fachbereich 4 – Pflanzliche Erzeugung, Referat Bodenkultur, zur Verfügung gestellt. Die zusammengetragenen Inhalte bilden die fachliche Basis zur Anfertigung von Informationsmaterial über die Möglichkeiten der Einflussnahme auf den vorbeugenden Hochwasserschutz durch die Akteure des ländlichen Raumes (landwirtschaftliche Unternehmen, Grundeigentümer, Gemeinden, Zweckverbände, Teilnehmergemeinschaften u. a.).

Heavy rains and El Nio phenomenon are recurring natural phenomena at a national level. These can cause floods due to the overflowing of rivers, which, when close to cities, can cause both human and material losses. The district of Catacaos, located in the city of Piura, was the one with the highest number of injuries due to the flood caused by El Nio phenomenon in 2017. This phenomenon causes a large amounts of rainfalls due to the presence of abnormally warm waters along the northern coast of Peru [1]. It is for this reason that the need arose to carry out an analysis of the physical vulnerability due to instability of people through static equilibrium, in said district, in order to present maps of unsafe areas in the face of this phenomenon. In this investigation, flood hazard maps are generated simulating the one presented in 2017, using 2D hydraulic modeling. For the generation of vulnerability curves, the instability analysis is performed by moment and drag force. Finally, maps with unsafe areas are made using ArcGis software. Where the results obtained indicate that 29.37% of the city was flooded. Likewise, the vulnerability maps generated show us that women and men over 18 years of age in the city of Catacaos would be vulnerable to dragging and overturning in the face of floods in 16.54% and 13.21%, respectively, of the total studied area. This information will be useful for the development of future evacuation plans during floods, carried out by national entities. © Published under licence by IOP Publishing Ltd.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23171号 / 工博第4815号 / 新制||工||1752(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 田中 茂信, 准教授 田中 賢治, 准教授 佐山 敬洋 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Jamaica, the third largest island in the Caribbean, has been affected significantly by flooding and flood-related damage. Hence assessing the probability of flooding and susceptibility of a place to flood hazard has become a vital part of planning and development. In addition to heavy rainfall from tropical storms and Atlantic hurricanes, several terrestrial factors play significant roles in flooding, including local geology, geomorphology, hydrology and land-use. In this study, a GIS-based multi-criteria statistical methodology was developed to quantify hazard potential and to map flood characteristics. Fourteen factors potentially responsible for flooding were identified and used as initial input in a hybrid model that combined principal component analysis with logistic regression and frequency distribution analysis. Of these factors, seven explained 65 % of the variation in the data: elevation, slope angle, slope aspect, flow accumulation, a topographic wetness index, proximity to a stream network, and hydro-stratigraphic units. These were used to prepare the island’s first map of flood hazard potential. Hazard potential was classified from very low to very high, nearly one-fifth (19.4 %) of the island was included within high or very high flood hazard zones. Further analysis revealed that areas prone to flooding are often low-lying and flat, or have shallow north- or northwest-facing slopes, are in close proximity to the stream network, and are situated on underlying impermeable lithology. The multi-criteria hybrid approach developed could classify 86.8 % of flood events correctly and produced a satisfactory validation result based on the receiver operating characteristic curve. The statistical method can be easily repeated and refined upon the availability of additional or higher quality data such as a high resolution digital elevation model. Additionally, the approach used in this study can be adopted to evaluate flood hazard in countries with similar characteristics, landscapes and climatic conditions, such as other Caribbean or Pacific Small Island Developing States.

Pluvial flood is a natural hazard that severely threatens people’s property and safety. With the development of algorithms and computer technologies, numerical modeling has emerged as an effective tool for predicting the impacts of floods. Despite being one of the most costly types of floods in West Africa, pluvial flooding has not been studied as extensively as riverine flooding, probably because modeling runoff across urban areas remains a challenge. Recently, a module based on the SCS Curve Number Method is incorporated in the open-source software TELEAMC-2D, which provides a possibility to model the infiltration process dynamically. TELEMAC-2D is one of the first hydraulic models to consider hydrologic parameters. Although the update is expected to increase the suitability of TELAMC-2D in pluvial flood modeling, the infiltration routine has not yet been tested in a real situation in a semi-arid area. This study aims to investigate the capability of TELEMAC-2D in simulating the rainfall-runoff process during a pluvial flood event in a semi-arid urban area, Niamey city in west Africa. Due to the lack of calibration data, a hydrological model SWAT is used to evaluate the performance of TELEMAC-2D. Through the comparison between the runoffs generated by the two models, it is found that TELEMAC-2D has a similar trend with SWAT in runoff simulation. However, TELEMAC-2D significantly overestimates the runoff magnitude despite having the same SCS values as SWAT. The reason for the overestimation is TELEMAC-2D that does not properly consider evaporation. Two suggestions are made to improve pluvial floods simulations using TELEMAC-2D in semi-arid areas: 1) couple TELEMAC-2D with a hydrologic model, and use net rainfall generated by the hydrologic model as precipitation input; 2) provide functions in infiltration subroutine that calculate rainfall abstractions by other hydrologic phenomena in addition to the infiltration process.

Flood risk analysis is the instrument for utility managers to create a sound strategy and adaptation plans into their communities. Local municipalities are being continuously challenged every year by the impacts of climate change. The need to develop a screening tool to analyze watersheds and find risk areas is the goal of this research. Open source high-quality data is allowing climate scientists to create innovative ways to study watersheds when performing spatial analysis for inundation areas. The development procedures for a screening tool involved combining readily available data on topography, groundwater, surface water, tidal information for coastal communities, soils, open space, and rainfall data. All efforts to help develop a planning level framework that allows investigators to target the optimal set of outcomes for a given community. This framework appears to be viable across cities that may be inundated with water due to sea-level rise, rainfall, runoff upstream, and other natural events. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

Indiana University-Purdue University Indianapolis (IUPUI) / The frequency and magnitude of flooding events on the Lower Ohio River and their relationship with climate are investigated using a ca. 2000-year-long sediment core collected from Goose Pond, Indiana. Using high-resolution radiocarbon dating (n = 25), late Holocene sedimentation rates were calculated for Goose Pond. Changes in sediment accumulation rates are attributed to variations in the frequency of flooding events on the lower Ohio River. Elevated sedimentation rates immediately following the formation of Goose Pond ca. 2000 years ago persisted until 680 CE, suggesting regular flooding during this interval. Between 680 and 1190 CE, sedimentation rates decreased dramatically and abruptly, indicating a reduction in flood frequencies. Sedimentation rates subsequently increased again at ca. 1190 CE and persisted at a similar level until 1850 CE, suggesting that flooding frequencies increased during a time that overlapped with the Little Ice Age (LIA; 1250-1850 CE). Sedimentation rates increased again at ca. 1850 CE, reaching a 2000-year high (3.33 cm/yr) at 1970 CE and indicating a period characterized by frequent flooding and landscape erosion. The flood record from Goose Pond shows similarities with other Lower Ohio River flood reconstructions from Avery Lake, IL, and Hovey Lake, IN, suggesting the Goose Pond record reflects the regional flooding history for the lower Ohio River. Comparison with paleoclimate records from the Midwest supports the idea that lower Ohio River flood frequencies prior to Euro American occupation in the 1800s increased during times when winter precipitation predominated as a result of atmospheric circulation changes resembling the Pacific North vii American mode (PNA) that appear to have been driven in part by the Pacific Decadal Oscillation (PDO). Following Euro-American land clearance, lower Ohio River flooding increased dramatically despite a decrease in winter precipitation. This likely reflects an increase in runoff and erosion as a result of deforestation and landscape conversion to intensive row crop agriculture. As climate continues to change and the Midwestern United States continues to see an increase in precipitation, both winter and summer, flood frequencies could be expected to increase still further.