APT Blanket Thermal Analyses of Top Horizontal Row 1 Modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shadday, M.A.

1999-09-20

The Accelerator Production of Tritium (APT) cavity flood system (CFS) is designed to be the primary safeguard for the integrity of the blanket modules during loss of coolant accidents (LOCAs). For certain large break LOCAs the CFS also provides backup for the residual heat removal systems (RHRs) in cooling the target assemblies. In the unlikely event that the internal flow passages in a blanket module or target assembly dryout, decay heat in the metal structures will be dissipated to the CFS through the module or assembly walls (i.e., rung outer walls). The target assemblies consist of tungsten targets encased inmore » steel conduits, and they can safely sustain high metal temperatures. Under internally dry conditions, the cavity flood fluid will cool the target assemblies with vigorous nucleate boiling on the external surfaces. However, the metal structures in the blanket modules consist of lead cladded in aluminum, and they have a long-term exposure temperature limit currently set to 150 degrees C. Simultaneous LOCAs in both the target and blanket heat removal systems (HRS) could result in dryout of the target ladders, as well as the horizontal blanket modules above the target. The cavity flood coolant would boil on the outside surfaces of the target ladder rungs, and the resultant steam could reduce the effectiveness of convection heat transfer from the blanket modules to the cavity flood coolant. A two-part analysis was conducted to ascertain if the cavity flood system can adequately cool the blanket modules above the targets, even when boiling is occurring on the outer surfaces of the target ladder rungs. The first part of the analysis was to model transient thermal conduction in the front top horizontal row 1 module (i.e. top horizontal modules nearest the incoming beam), while varying parametrically the convection heat transfer coefficient (htc) for the external surfaces exposed to the cavity flood flow. This part of the analysis demonstrated that the module could adequately conduct heat to the outer module surfaces, given reasonable values for the convection heat transfer coefficients. The second part of the analysis consisted of two-phase flow modeling of the natural circulation of the cavity flood fluid past the top modules. Slots in the top shield allow the cavity flood fluid to circulate. The required width for these slots, to prevent steam from backing up and blanketing the outer surfaces of the top modules, was determined.« less

Stakeholder views on flood risk management in Hungary's Upper Tisza Basin.

PubMed

Vari, Anna; Linnerooth-Bayer, Joanne; Ferencz, Zoltan

2003-06-01

With escalating costs of flood mitigation and relief, a challenge for the Hungarian government is to develop a flood mitigation and insurance/relief system that is viewed as efficient and fair by the many stakeholders involved. To aid policymakers in this task, this article reports on a recent study to elicit stakeholder views on flood risk management in the Upper Tisza Basin, including views on appropriate means of reducing losses and for transferring the residual losses from the direct victims to taxpayers or an insurance pool. This study is part of a project to develop an integrated approach to flood risk management coordinated by the International Institute of Applied Systems Analysis (IIASA) in collaboration with Swedish and Hungarian researchers. The discussion begins by describing the background of flood risk management problems in the Upper Tisza Basin. The results of interviews carried out with selected key stakeholders and the results of a public survey eliciting views on flood risk management are reported. The final section draws conclusions on incorporating stakeholder views into a flood risk management model, which will be used to illustrate policy paths at an upcoming stakeholder workshop. The conclusions are also of direct interest to Hungarian policymakers.

77 FR 18844 - Proposed Flood Hazard Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-28

...: Internal Agency Docket No. FEMA-B-1236] Proposed Flood Hazard Determinations AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice. SUMMARY: Comments are requested on proposed flood hazard determinations, which may include additions or modifications of any Base Flood Elevation (BFE), base flood depth...

78 FR 49277 - Proposed Flood Hazard Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

...: Internal Agency Docket No. FEMA-B-1345] Proposed Flood Hazard Determinations AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice. SUMMARY: Comments are requested on proposed flood hazard determinations, which may include additions or modifications of any Base Flood Elevation (BFE), base flood depth...

77 FR 74142 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-13

...-2011-0002; Internal Agency Docket No. FEMA-B-1100 and FEMA-B-1222] Proposed Flood Elevation... Base (1% annual-chance) Flood Elevations (BFEs) and modified BFEs for communities participating in the National Flood Insurance Program (NFIP), in accordance with section 110 of the Flood Disaster Protection...

Hydro-meteorological risk reduction and climate change adaptation in the Sava River Basin

NASA Astrophysics Data System (ADS)

Brilly, Mitja; Šraj, Mojca; Kryžanowski, Andrej

2017-04-01

The Sava River Basin covered the teritory of several countries. There were, in past thirty years, several flood hazard events with almost hundred years return period. Parts of the basin suffer by severe droughts also. In the presentation we covered questions of: • Flood hazard in complex hydrology structure • Landslide and flush flood in mountainous regions • Floods on karst polje • Flood risk management in the complex international and hydrological condition. • Impact of man made structures: hydropower storages, inundation ponds, river regulation, alternate streams, levees system, pumping stations, Natura 2000 areas etc. • How to manage droughts in the international river basin The basin is well covered by information and managed by international the SRB Commission (http://savacommission.org/) that could help. We develop study for climate change impact on floods on entire river basin financing by UNECE. There is also study provide climate change impact on the water management provide by World Bank and on which we take part. Recently is out call by world bank for study »Flood risk management plan for the SRB«.

Global Floods and Droughts Simulation to Support International Flood Initiative and International Drought Initiative of the UNESCO International Hydrological Program

NASA Astrophysics Data System (ADS)

Gusyev, M.; Takeuchi, K.; Magome, J.; Masood, M.

2015-12-01

One of the main achievements of the IHD/IHP programs is the promotion and enhancement of hydrological data exchange within the global water community. World Catalogue of Very Large Floods, World Water Balance and Water Resources of the Earth are the great examples of some initial collaborative efforts and the FRIEND and Catalogue of Rivers for Southeast Asia and the Pacific are the more recent outcomes. Along with similar efforts by WMO, FAO, IGBP, CEOS and many other national and international institutes, the global hydrological monitoring and nowcast have made a considerable progress last decade and are about to put into practice. Such efforts include global streamflow alert system of U Maryland and GFAS-streamflow of ICHARM and U Yamanshi. Especially the recent achievements of GFAS-streamflow support the current efforts of IHP International Flood Initiative (IFI) and International Drought Initiatives (IDI) by global nowcasts and easily visible indicators in 20-km resolution.

Emotions, trust, and perceived risk: affective and cognitive routes to flood preparedness behavior.

PubMed

Terpstra, Teun

2011-10-01

Despite the prognoses of the effects of global warming (e.g., rising sea levels, increasing river discharges), few international studies have addressed how flood preparedness should be stimulated among private citizens. This article aims to predict Dutch citizens' flood preparedness intentions by testing a path model, including previous flood hazard experiences, trust in public flood protection, and flood risk perceptions (both affective and cognitive components). Data were collected through questionnaire surveys in two coastal communities (n= 169, n= 244) and in one river area community (n= 658). Causal relations were tested by means of structural equation modeling (SEM). Overall, the results indicate that both cognitive and affective mechanisms influence citizens' preparedness intentions. First, a higher level of trust reduces citizens' perceptions of flood likelihood, which in turn hampers their flood preparedness intentions (cognitive route). Second, trust also lessens the amount of dread evoked by flood risk, which in turn impedes flood preparedness intentions (affective route). Moreover, the affective route showed that levels of dread were especially influenced by citizens' negative and positive emotions related to their previous flood hazard experiences. Negative emotions most often reflected fear and powerlessness, while positive emotions most frequently reflected feelings of solidarity. The results are consistent with the affect heuristic and the historical context of Dutch flood risk management. The great challenge for flood risk management is the accommodation of both cognitive and affective mechanisms in risk communications, especially when most people lack an emotional basis stemming from previous flood hazard events. © 2011 Society for Risk Analysis.

Challenges estimating the return period of extreme floods for reinsurance applications

NASA Astrophysics Data System (ADS)

Raven, Emma; Busby, Kathryn; Liu, Ye

2013-04-01

Mapping and modelling extreme natural events is fundamental within the insurance and reinsurance industry for assessing risk. For example, insurers might use a 1 in 100-year flood hazard map to set the annual premium of a property, whilst a reinsurer might assess the national scale loss associated with the 1 in 200-year return period for capital and regulatory requirements. Using examples from a range of international flood projects, we focus on exploring how to define what the n-year flood looks like for predictive uses in re/insurance applications, whilst considering challenges posed by short historical flow records and the spatial and temporal complexities of flood. First, we shall explore the use of extreme value theory (EVT) statistics for extrapolating data beyond the range of observations in a marginal analysis. In particular, we discuss how to estimate the return period of historical flood events and explore the impact that a range of statistical decisions have on these estimates. Decisions include: (1) selecting which distribution type to apply (e.g. generalised Pareto distribution (GPD) vs. generalised extreme value distribution (GEV)); (2) if former, the choice of the threshold above which the GPD is fitted to the data; and (3) the necessity to perform a cluster analysis to group flow peaks to temporally represent individual flood events. Second, we summarise a specialised multivariate extreme value model, which combines the marginal analysis above with dependence modelling to generate industry standard event sets containing thousands of simulated, equi-probable floods across a region/country. These events represent the typical range of anticipated flooding across a region and can be used to estimate the largest or most widespread events that are expected to occur. Finally, we summarise how a reinsurance catastrophe model combines the event set with detailed flood hazard maps to estimate the financial cost of floods; both the full event set and also individual extreme events. Since the predicted loss estimates, typically in the form of a curve plotting return period against modelled loss, are used in the pricing of reinsurance, we demonstrate the importance of the estimated return period and understanding the uncertainties associated with it.

Diversity of endophytic fungi of Myricaria laxiflora grown under pre- and post-flooding conditions.

PubMed

Tian, W; Bi, Y H; Zeng, W; Jiang, W; Xue, Y H; Wang, G X; Liu, S P

2015-09-09

Myricaria laxiflora is distributed along the riverbanks of the Yangtze River valley. The Three Gorges Dam has dramatically changed the habitat of M. laxiflora, which has evolved to develop increased resistance to flooding stress. In order to elucidate the relationship between plant endophytic fungi and flooding stress, we isolated and taxonomically characterized the endophytic fungi of M. laxiflora. One hundred and sixty-three fungi were isolated from healthy stems, leaves and roots of M. laxiflora grown under pre- and post-flooding conditions. Culture and isolation were carried out under aerobic and anaerobic conditions. Based on internal transcribed spacer sequence analysis and morphological characteristics, the isolates exhibited abundant biodiversity; they were classified into 5 subphyla, 7 classes, 12 orders, 17 families, and 26 genera. Dominant endophytes varied between pre- and post-flooding plants, among different plant tissues, and between aerobic and anaerobic culture conditions. Aspergillus and Alternaria accounted for more than 55% of all isolates. Although the number of isolates from post-flooding plants was greater, endophytes from pre-flooding plants were more diverse and abundant. Endophytes were distributed preferentially in particular tissues; this affinity was constrained by both the host habitat and the oxygen availability of the host.

Survey of Microbial Diversity in Flood Areas during Thailand 2011 Flood Crisis Using High-Throughput Tagged Amplicon Pyrosequencing.

PubMed

Mhuantong, Wuttichai; Wongwilaiwalin, Sarunyou; Laothanachareon, Thanaporn; Eurwilaichitr, Lily; Tangphatsornruang, Sithichoke; Boonchayaanant, Benjaporn; Limpiyakorn, Tawan; Pattaragulwanit, Kobchai; Punmatharith, Thantip; McEvoy, John; Khan, Eakalak; Rachakornkij, Manaskorn; Champreda, Verawat

2015-01-01

The Thailand flood crisis in 2011 was one of the largest recorded floods in modern history, causing enormous damage to the economy and ecological habitats of the country. In this study, bacterial and fungal diversity in sediments and waters collected from ten flood areas in Bangkok and its suburbs, covering residential and agricultural areas, were analyzed using high-throughput 454 pyrosequencing of 16S rRNA gene and internal transcribed spacer sequences. Analysis of microbial community showed differences in taxa distribution in water and sediment with variations in the diversity of saprophytic microbes and sulfate/nitrate reducers among sampling locations, suggesting differences in microbial activity in the habitats. Overall, Proteobacteria represented a major bacterial group in waters, while this group co-existed with Firmicutes, Bacteroidetes, and Actinobacteria in sediments. Anaeromyxobacter, Steroidobacter, and Geobacter were the dominant bacterial genera in sediments, while Sulfuricurvum, Thiovirga, and Hydrogenophaga predominated in waters. For fungi in sediments, Ascomycota, Glomeromycota, and Basidiomycota, particularly in genera Philipsia, Rozella, and Acaulospora, were most frequently detected. Chytridiomycota and Ascomycota were the major fungal phyla, and Rhizophlyctis and Mortierella were the most frequently detected fungal genera in water. Diversity of sulfate-reducing bacteria, related to odor problems, was further investigated using analysis of the dsrB gene which indicated the presence of sulfate-reducing bacteria of families Desulfobacteraceae, Desulfobulbaceae, Syntrobacteraceae, and Desulfoarculaceae in the flood sediments. The work provides an insight into the diversity and function of microbes related to biological processes in flood areas.

Assessing surface water flood risk and management strategies under future climate change: Insights from an Agent-Based Model.

PubMed

Jenkins, K; Surminski, S; Hall, J; Crick, F

2017-10-01

Climate change and increasing urbanization are projected to result in an increase in surface water flooding and consequential damages in the future. In this paper, we present insights from a novel Agent Based Model (ABM), applied to a London case study of surface water flood risk, designed to assess the interplay between different adaptation options; how risk reduction could be achieved by homeowners and government; and the role of flood insurance and the new flood insurance pool, Flood Re, in the context of climate change. The analysis highlights that while combined investment in property-level flood protection and sustainable urban drainage systems reduce surface water flood risk, the benefits can be outweighed by continued development in high risk areas and the effects of climate change. In our simulations, Flood Re is beneficial in its function to provide affordable insurance, even under climate change. However, the scheme does face increasing financial pressure due to rising surface water flood damages. If the intended transition to risk-based pricing is to take place then a determined and coordinated strategy will be needed to manage flood risk, which utilises insurance incentives, limits new development, and supports resilience measures. Our modelling approach and findings are highly relevant for the ongoing regulatory and political approval process for Flood Re as well as for wider discussions on the potential of insurance schemes to incentivise flood risk management and climate adaptation in the UK and internationally. Copyright © 2017 Elsevier B.V. All rights reserved.

Updated NASA Satellite Flood Map of Southeastern Texas (ALOS-2 Data)

NASA Image and Video Library

2017-08-31

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, used synthetic aperture radar imagery from the Japan Aerospace Exploration Agency's (JAXA) ALOS-2 satellite to create this Flood Proxy Map depicting areas of Southeastern Texas that are likely flooded as a result of Hurricane Harvey (shown by light blue pixels). The map is derived images taken before (July 30, 2017) and after (Aug. 27, 2017) Hurricane Harvey made landfall. The map covers an area of 220 by 400 miles (350 by 640 kilometers). Each pixel measures about 55 yards (50 meters) across. Local ground observations provided anecdotal preliminary validation. The results are also cross-validated with ARIA Sentinel-1 flood proxy map v0.2. The map should be used as guidance, and may be less reliable over urban areas. ALOS-2 data were accessed through the International Charter. https://photojournal.jpl.nasa.gov/catalog/PIA21931

Analysis of the French insurance market exposure to floods: a stochastic model combining river overflow and surface runoff

NASA Astrophysics Data System (ADS)

Moncoulon, D.; Labat, D.; Ardon, J.; Leblois, E.; Onfroy, T.; Poulard, C.; Aji, S.; Rémy, A.; Quantin, A.

2014-09-01

The analysis of flood exposure at a national scale for the French insurance market must combine the generation of a probabilistic event set of all possible (but which have not yet occurred) flood situations with hazard and damage modeling. In this study, hazard and damage models are calibrated on a 1995-2010 historical event set, both for hazard results (river flow, flooded areas) and loss estimations. Thus, uncertainties in the deterministic estimation of a single event loss are known before simulating a probabilistic event set. To take into account at least 90 % of the insured flood losses, the probabilistic event set must combine the river overflow (small and large catchments) with the surface runoff, due to heavy rainfall, on the slopes of the watershed. Indeed, internal studies of the CCR (Caisse Centrale de Reassurance) claim database have shown that approximately 45 % of the insured flood losses are located inside the floodplains and 45 % outside. Another 10 % is due to sea surge floods and groundwater rise. In this approach, two independent probabilistic methods are combined to create a single flood loss distribution: a generation of fictive river flows based on the historical records of the river gauge network and a generation of fictive rain fields on small catchments, calibrated on the 1958-2010 Météo-France rain database SAFRAN. All the events in the probabilistic event sets are simulated with the deterministic model. This hazard and damage distribution is used to simulate the flood losses at the national scale for an insurance company (Macif) and to generate flood areas associated with hazard return periods. The flood maps concern river overflow and surface water runoff. Validation of these maps is conducted by comparison with the address located claim data on a small catchment (downstream Argens).

76 FR 73534 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

...-2011-0002; Internal Agency Docket No. FEMA-B-1230] Proposed Flood Elevation Determinations AGENCY... proposed Base (1% annual-chance) Flood Elevations (BFEs) and proposed BFE modifications for the communities... regarding the proposed regulatory flood elevations for the reach described by the downstream and upstream...

Glacier generated floods

USGS Publications Warehouse

Walder, J.S.; Fountain, A.G.; ,

1997-01-01

Destructive floods result from drainage of glacier-dammed lakes and sudden release of water stored within glaciers. There is a good basis - both empirical and theoretical - for predicting the magnitude of floods from ice-dammed lakes, although some aspects of flood initiation need to be better understood. In contrast, an understanding of floods resulting from release of internally stored water remains elusive, owing to lack of knowledge of how and where water is stored and to inadequate understanding of the complex physics of the temporally and spatially variable subglacial drainage system.Destructive floods result from drainage of glacier-dammed lakes and sudden release of water stored within glaciers. There is a good basis - both empirical and theoretical - for predicting the magnitude of floods from ice-dammed lakes, although some aspects of flood initiation need to be better understood. In contrast, an understanding of floods resulting from release of internally stored water remains elusive, owing to lack of knowledge of how and where water is stored and to inadequate understanding of the complex physics of the temporally and spatially variable subglacial drainage system.

Rio Soliette (haiti): AN International Initiative for Flood-Hazard Assessment and Mitigation

NASA Astrophysics Data System (ADS)

Gandolfi, S.; Castellarin, A.; Barbarella, M.; Brath, A.; Domeneghetti, A.; Brandimarte, L.; Di Baldassarre, G.

2013-01-01

Natural catastrophic events are one of most critical aspects for health and economy all around the world. However, the impact in a poor region can impact more dramatically than in others countries. Isla Hispaniola (Haiti and the Dominican Republic), one of the poorest regions of the planet, has repeatedly been hit by catastrophic natural disasters that caused incalculable human and economic losses. After the catastrophic flood event occurred in the basin of River Soliette on May 24th, 2004, the General Direction for Development and Cooperation of the Italian Department of Foreign Affairs funded an international cooperation initiative (ICI) coordinated by the University of Bologna, that involved Haitian and Dominican institutions.Main purpose of the ICI was hydrological and hydraulic analysis of the May 2004 flood event aimed at formulating a suitable and affordable flood risk mitigation plan, consisting of structural and non-structural measures. In this contest, a topographic survey was necessary to realize the hydrological model and to improve the knowledge in some areas candidates to be site for mitigation measures.To overcome the difficulties arising from the narrowness of funds, surveyors and limited time available for the survey, only GPS technique have been used, both for framing aspects (using PPP approach), and for geometrical survey of the river by means of river cross-sections and detailed surveys in two areas (RTK technique). This allowed us to reconstruct both the river geometry and the DTM's of two expansion areas (useful for design hydraulic solutions for mitigate flood-hazard risk).

Survey of Microbial Diversity in Flood Areas during Thailand 2011 Flood Crisis Using High-Throughput Tagged Amplicon Pyrosequencing

PubMed Central

Mhuantong, Wuttichai; Wongwilaiwalin, Sarunyou; Laothanachareon, Thanaporn; Eurwilaichitr, Lily; Tangphatsornruang, Sithichoke; Boonchayaanant, Benjaporn; Limpiyakorn, Tawan; Pattaragulwanit, Kobchai; Punmatharith, Thantip; McEvoy, John; Khan, Eakalak; Rachakornkij, Manaskorn; Champreda, Verawat

2015-01-01

The Thailand flood crisis in 2011 was one of the largest recorded floods in modern history, causing enormous damage to the economy and ecological habitats of the country. In this study, bacterial and fungal diversity in sediments and waters collected from ten flood areas in Bangkok and its suburbs, covering residential and agricultural areas, were analyzed using high-throughput 454 pyrosequencing of 16S rRNA gene and internal transcribed spacer sequences. Analysis of microbial community showed differences in taxa distribution in water and sediment with variations in the diversity of saprophytic microbes and sulfate/nitrate reducers among sampling locations, suggesting differences in microbial activity in the habitats. Overall, Proteobacteria represented a major bacterial group in waters, while this group co-existed with Firmicutes, Bacteroidetes, and Actinobacteria in sediments. Anaeromyxobacter, Steroidobacter, and Geobacter were the dominant bacterial genera in sediments, while Sulfuricurvum, Thiovirga, and Hydrogenophaga predominated in waters. For fungi in sediments, Ascomycota, Glomeromycota, and Basidiomycota, particularly in genera Philipsia, Rozella, and Acaulospora, were most frequently detected. Chytridiomycota and Ascomycota were the major fungal phyla, and Rhizophlyctis and Mortierella were the most frequently detected fungal genera in water. Diversity of sulfate-reducing bacteria, related to odor problems, was further investigated using analysis of the dsrB gene which indicated the presence of sulfate-reducing bacteria of families Desulfobacteraceae, Desulfobulbaceae, Syntrobacteraceae, and Desulfoarculaceae in the flood sediments. The work provides an insight into the diversity and function of microbes related to biological processes in flood areas. PMID:26020967

Dynamic analysis of an inflatable dam subjected to a flood

NASA Astrophysics Data System (ADS)

Lowery, K.; Liapis, S.

A dynamic simulation of the response of an inflatable dam subjected to a flood is carried out to determine the survivability envelope of the dam where it can operate without rupture, or overflow. The free-surface flow problem is solved in two dimensions using a fully nonlinear mixed Eulerian-Lagrangian formulation. The dam is modeled as an elastic shell inflated with air and simply supported from two points. The finite element method is employed to determine the dynamic response of the structure using ABAQUS with a shell element. The problem is solved in the time domain which allows the prediction of a number of transient phenomena such as the generation of upstream advancing waves, the dynamic structural response and structural failure. Failure takes place when the dam either ruptures or overflows. Stresses in the dam material were monitored to determine when rupture occurs. An iterative study was performed to find the serviceability envelope of the dam in terms of the internal pressure and the flood Froude number for two flood depths. It was found that existing inflatable dams are quite effective in suppressing floods for a relatively wide range of flood velocities.

Rapid-response flood mapping during Hurricanes Harvey, Irma and Maria by the Global Flood Partnership (GFP)

NASA Astrophysics Data System (ADS)

Cohen, S.; Alfieri, L.; Brakenridge, G. R.; Coughlan, E.; Galantowicz, J. F.; Hong, Y.; Kettner, A.; Nghiem, S. V.; Prados, A. I.; Rudari, R.; Salamon, P.; Trigg, M.; Weerts, A.

2017-12-01

The Global Flood Partnership (GFP; https://gfp.jrc.ec.europa.eu) is a multi-disciplinary group of scientists, operational agencies and flood risk managers focused on developing efficient and effective global flood management tools. Launched in 2014, its aim is to establish a partnership for global flood forecasting, monitoring and impact assessment to strengthen preparedness and response and to reduce global disaster losses. International organizations, the private sector, national authorities, universities and research agencies contribute to the GFP on a voluntary basis and benefit from a global network focused on flood risk reduction. At the onset of Hurricane Harvey, GFP was `activated' using email requests via its mailing service. Soon after, flood inundation maps, based on remote sensing analysis and modeling, were shared by different agencies, institutions, and individuals. These products were disseminated, to varying degrees of effectiveness, to federal, state and local agencies via emails and data-sharing services. This generated a broad data-sharing network which was utilized at the early stages of Hurricane Irma's impact, just two weeks after Harvey. In this presentation, we will describe the extent and chronology of the GFP response to both Hurricanes Harvey, Irma and Maria. We will assess the potential usefulness of this effort for event managers in various types of organizations and discuss future improvements to be implemented.

Slovak Flood Forecasting Service at the National and International Level

NASA Astrophysics Data System (ADS)

Leskova, Danica; Mikuličková, Michaela

2017-04-01

National Flood Forecasting Service is based on national legislation /Slovak legislation/ so that it could deal with the flood situation at the local level. Information about international rivers, e.g.: Danube, March (Morava), Uh, and Latorica are received on the basis of bilateral agreements. An important supplementary information is the European Flood Awareness System (EFAS). In this presentation a forecasting system POVAPSYS, which has been in Slovakia in use since 2016, is also shown. The Slovak Hydrometeorological Institute (SHMI) is a partner of EFAS, but simultaneously is a part of consortium of the EFAS Dissemination Centre, and its role is to analyze results of models, to analyze hydrometeorological situation, to disseminate information, and to send flood notifications to the EFAS partners. Both systems will be presented.

Flood model for Brazil

NASA Astrophysics Data System (ADS)

Palán, Ladislav; Punčochář, Petr

2017-04-01

Looking on the impact of flooding from the World-wide perspective, in last 50 years flooding has caused over 460,000 fatalities and caused serious material damage. Combining economic loss from ten costliest flood events (from the same period) returns a loss (in the present value) exceeding 300bn USD. Locally, in Brazil, flood is the most damaging natural peril with alarming increase of events frequencies as 5 out of the 10 biggest flood losses ever recorded have occurred after 2009. The amount of economic and insured losses particularly caused by various flood types was the key driver of the local probabilistic flood model development. Considering the area of Brazil (being 5th biggest country in the World) and the scattered distribution of insured exposure, a domain covered by the model was limited to the entire state of Sao Paolo and 53 additional regions. The model quantifies losses on approx. 90 % of exposure (for regular property lines) of key insurers. Based on detailed exposure analysis, Impact Forecasting has developed this tool using long term local hydrological data series (Agencia Nacional de Aguas) from riverine gauge stations and digital elevation model (Instituto Brasileiro de Geografia e Estatística). To provide most accurate representation of local hydrological behaviour needed for the nature of probabilistic simulation, a hydrological data processing focused on frequency analyses of seasonal peak flows - done by fitting appropriate extreme value statistical distribution and stochastic event set generation consisting of synthetically derived flood events respecting realistic spatial and frequency patterns visible in entire period of hydrological observation. Data were tested for homogeneity, consistency and for any significant breakpoint occurrence in time series so the entire observation or only its subparts were used for further analysis. The realistic spatial patterns of stochastic events are reproduced through the innovative use of d-vine copula scheme to generate probabilistic flood event set. The derived design flows for selected rivers inside model domain were used as an input for 2-dimensional hydrodynamic inundation modelling techniques (using the tool TUFLOW by BMT WBM) on mesh size 30 x 30 metres. Outputs from inundation modelling and stochastic event set were implemented in the Aon Benfield's platform ELEMENTS developed and managed internally by Impact Forecasting; Aon Benfield internal catastrophe model development center. The model was designed to evaluate potential financial impact caused by fluvial flooding on portfolios of insurance and/or reinsurance companies. The structure of presented model follows typical scheme of financial loss catastrophe model and combines hazard with exposure and vulnerability to produce potential financial loss expressed in the form of loss exceedance probability curve and many other insured perspectives, such as average annual loss, event or quantile loss tables and etc. Model can take financial inputs as well as provide split of results for exact specified location or related higher administrative units: municipalities and 5-digit postal codes.

Assessing coastal flood risk and sea level rise impacts at New York City area airports

NASA Astrophysics Data System (ADS)

Ohman, K. A.; Kimball, N.; Osler, M.; Eberbach, S.

2014-12-01

Flood risk and sea level rise impacts were assessed for the Port Authority of New York and New Jersey (PANYNJ) at four airports in the New York City area. These airports included John F. Kennedy International, LaGuardia, Newark International, and Teterboro Airports. Quantifying both present day and future flood risk due to climate change and developing flood mitigation alternatives is crucial for the continued operation of these airports. During Hurricane Sandy in October 2012 all four airports were forced to shut down, in part due to coastal flooding. Future climate change and sea level rise effects may result in more frequent shutdowns and disruptions in travel to and from these busy airports. The study examined the effects of the 1%-annual-chance coastal flooding event for present day existing conditions and six different sea level rise scenarios at each airport. Storm surge model outputs from the Federal Emergency Management Agency (FEMA) provided the present day storm surge conditions. 50th and 90thpercentile sea level rise projections from the New York Panel on Climate Change (NPCC) 2013 report were incorporated into storm surge results using linear superposition methods. These projections were evaluated for future years 2025, 2035, and 2055. In addition to the linear superposition approach for storm surge at airports where waves are a potential hazard, one dimensional wave modeling was performed to get the total water level results. Flood hazard and flood depth maps were created based on these results. In addition to assessing overall flooding at each airport, major at-risk infrastructure critical to the continued operation of the airport was identified and a detailed flood vulnerability assessment was performed. This assessment quantified flood impacts in terms of potential critical infrastructure inundation and developed mitigation alternatives to adapt to coastal flooding and future sea level changes. Results from this project are advancing the PANYNJ's understanding of the effects of sea level rise on coastal flooding at the airports and guiding decision-making in the selection of effective adaptation actions. Given the importance of these airports to transportation, this project is advancing security and continuity of national and international commerce well into the 21st century.

Satellite images of the September 2013 flood event in Lyons, Colorado

USGS Publications Warehouse

Cole, Christopher J.; Friesen, Beverly A.; Wilds, Stanley; Noble, Suzanne; Warner, Harumi; Wilson, Earl M.

2013-01-01

The U.S. Geological Survey (USGS) Special Applications Science Center (SASC) produced an image base map showing high-resolution remotely sensed data over Lyons, Colorado—a city that was severely affected by the flood event that occurred throughout much of the Colorado Front Range in September of 2013. The 0.5-meter WorldView-2 data products were created from imagery collected by DigitalGlobe on September 13 and September 24, 2013, during and following the flood event. The images shown on this map were created to support flood response efforts, specifically for use in determining damage assessment and mitigation decisions. The raw, unprocessed imagery were orthorectified and pan-sharpened to enhance mapping accuracy and spatial resolution, and reproduced onto a cartographic base map. These maps are intended to provide a snapshot representation of post-flood ground conditions, which may be useful to decisionmakers and the general public. The SASC also provided data processing and analysis support for other Colorado flood-affected areas by creating cartographic products, geo-corrected electro-optical and radar image mosaics, and GIS water cover files for use by the Colorado National Guard, the National Park Service, the U.S. Forest Service, and the flood response community. All products for this International Charter event were uploaded to the USGS Hazards Data Distribution System (HDDS) website (http://hdds.usgs.gov/hdds2/) for distribution.

26 CFR 1.832-6 - Policyholders of mutual fire or flood insurance companies operating on the basis of premium...

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Other Insurance Companies § 1.832-6 Policyholders of mutual fire or flood insurance companies operating..., a taxpayer insured by a mutual fire or flood insurance company under a policy for which the premium... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Policyholders of mutual fire or flood insurance...

26 CFR 1.832-6 - Policyholders of mutual fire or flood insurance companies operating on the basis of premium...

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Other Insurance Companies § 1.832-6 Policyholders of mutual fire or flood insurance companies operating..., a taxpayer insured by a mutual fire or flood insurance company under a policy for which the premium... 26 Internal Revenue 8 2013-04-01 2013-04-01 false Policyholders of mutual fire or flood insurance...

26 CFR 1.832-6 - Policyholders of mutual fire or flood insurance companies operating on the basis of premium...

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Other Insurance Companies § 1.832-6 Policyholders of mutual fire or flood insurance companies operating..., a taxpayer insured by a mutual fire or flood insurance company under a policy for which the premium... 26 Internal Revenue 8 2012-04-01 2012-04-01 false Policyholders of mutual fire or flood insurance...

26 CFR 1.832-6 - Policyholders of mutual fire or flood insurance companies operating on the basis of premium...

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Other Insurance Companies § 1.832-6 Policyholders of mutual fire or flood insurance companies operating..., a taxpayer insured by a mutual fire or flood insurance company under a policy for which the premium... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Policyholders of mutual fire or flood insurance...

77 FR 18766 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-28

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2010-0003; Internal Agency Docket No. FEMA-B-1114] Proposed Flood Elevation Determinations Correction... locations above. Please refer to the revised Flood Insurance Rate Map located at the community map...

76 FR 3596 - Proposed Flood Elevation Determinations for York County, Maine (All Jurisdictions)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

...-2008-0020; Internal Agency Docket No. FEMA-B-1066] Proposed Flood Elevation Determinations for York... notice of proposed rulemaking concerning proposed flood elevation determinations for York County, Maine...: Luis Rodriguez, Chief, Engineering Management Branch, Federal Insurance and Mitigation Administration...

A pan-African medium-range ensemble flood forecast system

NASA Astrophysics Data System (ADS)

Thiemig, Vera; Bisselink, Bernard; Pappenberger, Florian; Thielen, Jutta

2015-04-01

The African Flood Forecasting System (AFFS) is a probabilistic flood forecast system for medium- to large-scale African river basins, with lead times of up to 15 days. The key components are the hydrological model LISFLOOD, the African GIS database, the meteorological ensemble predictions of the ECMWF and critical hydrological thresholds. In this study the predictive capability is investigated, to estimate AFFS' potential as an operational flood forecasting system for the whole of Africa. This is done in a hindcast mode, by reproducing pan-African hydrological predictions for the whole year of 2003 where important flood events were observed. Results were analysed in two ways, each with its individual objective. The first part of the analysis is of paramount importance for the assessment of AFFS as a flood forecasting system, as it focuses on the detection and prediction of flood events. Here, results were verified with reports of various flood archives such as Dartmouth Flood Observatory, the Emergency Event Database, the NASA Earth Observatory and Reliefweb. The number of hits, false alerts and missed alerts as well as the Probability of Detection, False Alarm Rate and Critical Success Index were determined for various conditions (different regions, flood durations, average amount of annual precipitations, size of affected areas and mean annual discharge). The second part of the analysis complements the first by giving a basic insight into the prediction skill of the general streamflow. For this, hydrological predictions were compared against observations at 36 key locations across Africa and the Continuous Rank Probability Skill Score (CRPSS), the limit of predictability and reliability were calculated. Results showed that AFFS detected around 70 % of the reported flood events correctly. In particular, the system showed good performance in predicting riverine flood events of long duration (> 1 week) and large affected areas (> 10 000 km2) well in advance, whereas AFFS showed limitations for small-scale and short duration flood events. Also the forecasts showed on average a good reliability, and the CRPSS helped identifying regions to focus on for future improvements. The case study for the flood event in March 2003 in the Sabi Basin (Zimbabwe and Mozambique) illustrated the good performance of AFFS in forecasting timing and severity of the floods, gave an example of the clear and concise output products, and showed that the system is capable of producing flood warnings even in ungauged river basins. Hence, from a technical perspective, AFFS shows a good prospective as an operational system, as it has demonstrated its significant potential to contribute to the reduction of flood-related losses in Africa by providing national and international aid organizations timely with medium-range flood forecast information. However, issues related to the practical implication will still need to be investigated.

Application of fuzzy weight of evidence and data mining techniques in construction of flood susceptibility map of Poyang County, China.

PubMed

Hong, Haoyuan; Tsangaratos, Paraskevas; Ilia, Ioanna; Liu, Junzhi; Zhu, A-Xing; Chen, Wei

2018-06-01

In China, floods are considered as the most frequent natural disaster responsible for severe economic losses and serious damages recorded in agriculture and urban infrastructure. Based on the international experience prevention of flood events may not be completely possible, however identifying susceptible and vulnerable areas through prediction models is considered as a more visible task with flood susceptibility mapping being an essential tool for flood mitigation strategies and disaster preparedness. In this context, the present study proposes a novel approach to construct a flood susceptibility map in the Poyang County, JiangXi Province, China by implementing fuzzy weight of evidence (fuzzy-WofE) and data mining methods. The novelty of the presented approach is the usage of fuzzy-WofE that had a twofold purpose. Firstly, to create an initial flood susceptibility map in order to identify non-flood areas and secondly to weight the importance of flood related variables which influence flooding. Logistic Regression (LR), Random Forest (RF) and Support Vector Machines (SVM) were implemented considering eleven flood related variables, namely: lithology, soil cover, elevation, slope angle, aspect, topographic wetness index, stream power index, sediment transport index, plan curvature, profile curvature and distance from river network. The efficiency of this new approach was evaluated using area under curve (AUC) which measured the prediction and success rates. According to the outcomes of the performed analysis, the fuzzy WofE-SVM model was the model with the highest predictive performance (AUC value, 0.9865) which also appeared to be statistical significant different from the other predictive models, fuzzy WofE-RF (AUC value, 0.9756) and fuzzy WofE-LR (AUC value, 0.9652). The proposed methodology and the produced flood susceptibility map could assist researchers and local governments in flood mitigation strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

Flood Impact Assessment in the Surrounding Area of Suvarnabhumi Airport, Thailand

NASA Astrophysics Data System (ADS)

Tingsanchali, Tawatchai; Eng, D.

2009-03-01

The existence of the Second Bangkok International Airport (SBIA) or the Suvarnabhumi International Airport induces more adverse effect to the flooding situation in its surrounding area. Due to limited drainage capacity, during a heavy storm, flooding in the surrounding area occurs over the area. The objective of the study is to find the most suitable flood control and drainage system that can drain floodwater from the surrounding area of 624 sq. km with minimum flood damages and impact to social and living conditions of the people in the study area. This study involves the application of MIKE FLOOD hydrodynamic model for determining the relative effects of flood control and drainage system in the surrounding area of the airport. The results of the study show that flood damages mostly occur in the central and downstream parts of the study area where drainage is insufficient. Flood depth and duration are main parameters used for the estimation of flood losses. Flood mitigation and management in the surrounding area of SBIA is planned by pumping water of 100 m3/s from Klong Samrong canal inside the study area through the proposed drainage channel to the Gulf of Thailand. The existing dikes along boundaries of the study area can protect water from the outer area to enter into the surrounding area of the airport. Flood simulation shows that a canal with capacity of 100 m3/s and a pumping station at the downstream end of the canal are required to cope with the drainage capacity for the flood of 100 years return period. A flood drainage channel of capacity of 100 m3/s is designed and will be constructed to drain flood from Klong Samrong to the sea. On the other hand, the embankment along the proposed drainage canal project improves traffic flow in the vicinity of the airport. On economic benefit, the project investment cost is Baht 8,410 million. The project benefit cost ratio is 2.12 with the economic internal rate of return of 15.61%. The construction period is 4 years. Environmental and social impacts are investigated and counter measures are proposed to reduce the impacts. The study considers compensating scheme for people who are directly affected by the flood drainage project and those who will lose their lands or their professions. Considerations are also extended to people who are indirectly affected by the project. Institutional framework is recommended to be established to manage flood control and drainage and water resources in the surrounding area of the airport.

Development of Urban Inundation Warning Model at Cyclic Artificial Water Way in Song-do International City, Republic of Korea

NASA Astrophysics Data System (ADS)

Lee, T.; Lee, C.; Kim, H.

2016-12-01

Abstract Song-do international city was constructed by reclaiming land from the coastal waters of Yeonsu-gu, Incheon Metropolitan City, Republic of Korea. The □-shaped cyclic artificial water way has been considered for improving water quality, waterfront and internal drainage in Song-do international city. By improving water quality, various marine facilities, such as marina, artificial beach, marine terminal, and so on, will be set up around the artificial water way for the waterfront. Since the water stage of the artificial water way changes depending on water gates operations, it is necessary to develop an urban inundation warning model to evaluate safeties of the waterfront facilities and its passengers. By considering characteristics of urban watershed, we calculate discharge flowing into the water way using XP-SWMM model. As a result of estimating 100-year flood frequency, although there are slight differences in drainage sections, the maximum flood discharge occurs in 90-min rainfall duration. In order to consider impacts of tide and hydraulic structure, we establish Inland drainage plans through the analysis of unsteady flow using HEC-RAS. The urban inundation warning model is configured to issue a warning when the water plain elevation exceeds EL. 1.5m which is usually managed at EL. 1.0m. In this study, the design flood stage of artificial water way and urban inundation warning model are developed for Song-do international city, and therefore it is expected that a reliability of management and operation of the waterfront facilities is improved. Keywords : Artificial Water Way; Waterfront; Urban Inundation Warning Model. Acknowlegement This research was supported by a grant [MPSS-NH-2015-79] through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

The integrated effects of future climate and hydrologic uncertainty on sustainable flood risk management

NASA Astrophysics Data System (ADS)

Steinschneider, S.; Wi, S.; Brown, C. M.

2013-12-01

Flood risk management performance is investigated within the context of integrated climate and hydrologic modeling uncertainty to explore system robustness. The research question investigated is whether structural and hydrologic parameterization uncertainties are significant relative to other uncertainties such as climate change when considering water resources system performance. Two hydrologic models are considered, a conceptual, lumped parameter model that preserves the water balance and a physically-based model that preserves both water and energy balances. In the conceptual model, parameter and structural uncertainties are quantified and propagated through the analysis using a Bayesian modeling framework with an innovative error model. Mean climate changes and internal climate variability are explored using an ensemble of simulations from a stochastic weather generator. The approach presented can be used to quantify the sensitivity of flood protection adequacy to different sources of uncertainty in the climate and hydrologic system, enabling the identification of robust projects that maintain adequate performance despite the uncertainties. The method is demonstrated in a case study for the Coralville Reservoir on the Iowa River, where increased flooding over the past several decades has raised questions about potential impacts of climate change on flood protection adequacy.

Comparative analysis between the floods and the rate of urbanization in the Ribeira Valley, São Paulo - Brazil

NASA Astrophysics Data System (ADS)

Ferreira, B. C.; Valverde, M. C.

2013-05-01

The aim of this paper is to analyze the occurrence of floods facing the rate of urbanization in the Ribeira Valley. The Ribeira Valley is located on the basin of Ribeira de Iguape River in eastern Paraná and southeastern São Paulo state in Brazil. The region has been considered one of the most important international conservation priorities by agencies such as the International Union for the Conservation of Nature (IUCN), and the UNESCO/MAB Program. This region has a history of recurrent floods, causing huge financial losses particularly to the poorest people, including casualties as well as material losses. This study analyzed three flood events that occurred in January 1995, January 1997 and February-March 1998, reaching the towns of Eldorado, Ribeira and Sete Barras. To determine the affected areas, the researchers used the shapes (digital data) obtained from the Geographic Information System of Ribeira de Iguape River Basin which is maintained by the Ribeira de Iguape River Basin and South Seashore Committee. The SPRING was the processing tool used for data manipulation. Additionally we used rainfall data, flow and water level elevation for the years 1983, 1995, 1997, 1998 and 2011. The results show that in January 1997 there happened the largest flood area across the three cities and this effect coincides with the highest levels of rainfall and flow. The second largest flood happened in January 1995 and the smallest one was in February-March 1998. Another important aspect to be noted is that all floods affected a large floodplain in both rural and urban areas. It was also found a direct relationship between the rate of urbanization and the area affected by the floods. The results show that the larger the area of urbanization, the larger the flooded area. It was also verified in the precipitation climatology that most extreme events occurred in 1983 and 2011. Specifically the 2011 event occurred during dry season bringing the whole region to a state of emergency, reaching 17 municipalities. The Ribeira Valley reached its flood peak of 13.45 m on 08/02/2011 in Eldorado with a total of 27,931 people affected. Since the urban areas for the cities studied are vulnerable to flood risk, it is necessary a thorough registration of the worst event reaching the whole area and the people affected in order to find the best way to mitigate the impacts of this natural disaster.

26 CFR 1.832-6 - Policyholders of mutual fire or flood insurance companies operating on the basis of premium...

Code of Federal Regulations, 2010 CFR

2010-04-01

... Insurance Companies § 1.832-6 Policyholders of mutual fire or flood insurance companies operating on the... taxpayer insured by a mutual fire or flood insurance company under a policy for which the premium deposit... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Policyholders of mutual fire or flood insurance...

A Framework for Flood Risk Analysis and Benefit Assessment of Flood Control Measures in Urban Areas

PubMed Central

Li, Chaochao; Cheng, Xiaotao; Li, Na; Du, Xiaohe; Yu, Qian; Kan, Guangyuan

2016-01-01

Flood risk analysis is more complex in urban areas than that in rural areas because of their closely packed buildings, different kinds of land uses, and large number of flood control works and drainage systems. The purpose of this paper is to propose a practical framework for flood risk analysis and benefit assessment of flood control measures in urban areas. Based on the concept of disaster risk triangle (hazard, vulnerability and exposure), a comprehensive analysis method and a general procedure were proposed for urban flood risk analysis. Urban Flood Simulation Model (UFSM) and Urban Flood Damage Assessment Model (UFDAM) were integrated to estimate the flood risk in the Pudong flood protection area (Shanghai, China). S-shaped functions were adopted to represent flood return period and damage (R-D) curves. The study results show that flood control works could significantly reduce the flood risk within the 66-year flood return period and the flood risk was reduced by 15.59%. However, the flood risk was only reduced by 7.06% when the flood return period exceeded 66-years. Hence, it is difficult to meet the increasing demands for flood control solely relying on structural measures. The R-D function is suitable to describe the changes of flood control capacity. This frame work can assess the flood risk reduction due to flood control measures, and provide crucial information for strategy development and planning adaptation. PMID:27527202

Flood Hazard Management: British and International Perspectives

NASA Astrophysics Data System (ADS)

James, L. Douglas

This proceedings of an international workshop at the Flood Hazard Research Centre (Queensway, Enfield, Middlesex, U.K.) begins by noting how past British research on flood problems concentrated on refining techniques to implement established policy. In contrast, research covered in North American and Australian publications involved normative issues on policy alternatives and administrative implementation. The workshop's participants included 16 widely recognized scientists, whose origins were about equally divided between Britain and overseas; from this group the workshop's organizers expertly drew ideas for refining British urban riverine flood hazard management and for cultivating links among researchers everywhere. Such intellectual exchange should be of keen interest to flood hazard program managers around the world, to students of comparative institutional performance, to those who make policy on protecting people from hazards, and to hydrologists and other geophysicists who must communicate descriptive information for bureaucratic, political, and public decision- making.

77 FR 55787 - Proposed Flood Elevation Determinations for the City of Carson City, NV

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-11

...-2011-0002; Internal Agency Docket No. FEMA-B-1233] Proposed Flood Elevation Determinations for the City of Carson City, NV AGENCY: Federal Emergency Management Agency, DHS. ACTION: Proposed rule... concerning proposed flood elevation determinations for the City of Carson City, Nevada. DATES: This...

77 FR 66790 - Proposed Flood Elevation Determinations for Madison County, AL and Incorporated Areas

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

...-2011-0002; Internal Agency Docket No. FEMA-B-1189] Proposed Flood Elevation Determinations for Madison... concerning proposed flood elevation determinations for Madison County, Alabama and Incorporated Areas. DATES... Mitigation Administration, Federal Emergency Management Agency, 500 C Street SW., Washington, DC 20472, (202...

78 FR 78808 - Proposed Flood Elevation Determinations for Pierce County, Washington, and Incorporated Areas

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-27

... sources in Pierce County, Washington. On April 16, 2012, FEMA published a proposed rulemaking at 77 FR...-2013-0002; Internal Agency Docket No. FEMA-B-7748] Proposed Flood Elevation Determinations for Pierce... proposed rule concerning proposed flood elevation determinations for Pierce County, Washington, and...

The study of the application of crystalline silicone solar cell type for a temporary flood camp

NASA Astrophysics Data System (ADS)

Hendarti, R.; Katarina, W.; Wangidjaja, W.

2017-12-01

During flood period, most of temporary evacuation shelters in Jakarta are lack in electricity because the local electricity company turned the electricity off to avoid any electrical problem because of the high water level over the flooded area. Whereas, the local electricity or the grid is the main energy source for the lighting and water pump machine, therefore the energy source becomes a significant issue during this period. Currently, the local government has already provided diesel generators to substitute the local grid when it is off, however, the amount of the generators is still limited. This study, therefore, investigated an alternative energy for the electricity, particularly solar energy and this paper presents an analysis of the Jakarta duration of sunshine during rainy seasons in order to investigate which Crystalline Silicone solar cell type that can be implemented optimally for energy supply in the period of flood evacuation as well as for the shelter. A deep analysis on literature review was conducted on the three types of Crystalline Silicone solar cell, Jakarta local weather. Furthermore, the standard of International Federation of Red Cross and Red Crescent Societies (IFRC) was also studied for the shelter design. The results of this study could be used as a reference for the local authority in providing the substitute energy supply in the temporary evacuation area during flood period in which the solar energy source could be also attached on the shelter.

The potential of historical hydrology in Switzerland

NASA Astrophysics Data System (ADS)

Wetter, Oliver

2017-11-01

Historical hydrology is based on data derived from historical written, pictorial and epigraphic documentary sources. It lies at the interface between hydrology and environmental history, using methodologies from both disciplines basically with the goal of significantly extending the instrumental measurement period with experience from the pre-instrumental past. Recently this field of research has gained increased recognition as a tool to improve current flood risk estimations when EU guidelines regulated by law the quantitative consideration of previous floods.1 Awareness to consider pre-instrumental experience in flood risk analysis seems to have risen at the level of local and federal authorities in Switzerland as well. The 2011 Fukushima catastrophe probably fostered this rethinking process, when pressure from the media, society and politics as well as the regulations of the International Atomic Energy Agency (IAEA) forced the authorities to reassess the current flood risk analysis for Swiss nuclear power plants. In 2015 a historical hydrological study was commissioned by the Federal Office for the Environment (FOEN) to assess the magnitudes of pre-instrumental Aare River flood discharges, including the most important tributaries (the Saane, Emme, Reuss and Limmat rivers). The results of the historical hydrological study serve now as the basis for the main study, EXAR (commissioned under the lead of FOEN in cooperation with the Swiss Nuclear Safety Inspectorate (ENSI), the Swiss Federal Office of Energy (SFOE), the Federal Office for Civil Protection (FOCP), and the Federal Office of Meteorology and Climatology (MeteoSwiss)), which combines historical and climatological analysis with statistical approaches and mathematical models with the goal of better understanding the hazards and possible interactions that can be caused by extreme flood events. In a second phase the catchment of the River Rhine will be targeted as well. More recently several local historical hydrological studies of smaller catchments have been requested by the responsible local authorities. The course for further publicly requested historical hydrological analysis seems thus to have been set. This paper therefore intends to discuss the potential of historical hydrological analysis, with a focus on the specific situation in Switzerland. 1Guideline 2007/60/EG of the European Parliament and Council from 23 October 2007 on assessment and management of flood risks, Official Journal of the European Union, L 288, 27-34, Brussels, 2007.

Data expansion: the potential of grey literature for understanding floods

NASA Astrophysics Data System (ADS)

Uhlemann, S.; Bertelmann, R.; Merz, B.

2012-09-01

Sophisticated methods have been developed and become standard in analysing floods as well as for assessing the flood risk. However, increasingly critique of the current standards and scientific practice can be found both in the flood hydrology community as well as in the risk community who argue that the considerable amount of information already available on natural disasters has not been adequately deployed and brought to effective use. We describe this phenomenon as a failure to synthesize knowledge that results from barriers and ignorance in awareness, use and management of the entire spectrum of relevant content, that is, data, information and knowledge. In this paper we argue that the scientific community in flood risk research ignores event specific analysis and documentations as another source of data. We present results from a systematic search that includes an intensive study on sources and ways of information dissemination of flood relevant publications. We obtain 183 documents that contain information on the sources, pathways, receptors and/or consequences for any of the 40 strongest trans-basin floods in Germany in the period 1952-2002. This study therefore provides the most comprehensive meta-data collection of flood documentations for the considered geographical space and period. 87.5% of all events have been documented and especially the most severe floods have received extensive coverage. Only 30% of the material has been produced in the scientific/academic environment and the majority of all documents (about 80%) can be considered grey literature. Therefore, ignoring grey sources in flood research also means ignoring the largest part of knowledge available on single flood events (in Germany). Further, the results of this study underpin the rapid changes in information dissemination of flood event literature over the last decade. We discuss the options and obstacles of incorporating this data in the knowledge building process in the light of the current technological developments and international, interdisciplinary debates for data curation.

[Construction and validation of a socio-environmental vulnerability index for monitoring and management of natural disasters in the state of Rio de Janeiro, Brazil].

PubMed

Guimarães, Raphael Mendonça; Mazoto, Maíra Lopes; Martins, Raphael Nascimento; do Carmo, Cleber Nascimento; Asmus, Carmen Ildes Fróes

2014-10-01

Floods account for approximately 40% of natural disasters that occur around the world and they are therefore considered a major public health problem. While floods constitute a global problem, data from the International Strategy for Disaster Reduction showed that almost all of the deaths or individuals affected are concentrated in developing countries. It is assumed that, although they have natural causes, the consequences of floods also involve social issues. To try to predict such vulnerability in the occurrence of natural disasters, a social and environmental index that shows the degree of vulnerability of a location was developed in this paper. This index was developed using multivariate analysis involving factor analysis and demographic, social and environmental variables. The index was applied in the municipalities of the state of Rio de Janeiro and compared with the official figures of the Civil Defense Unit. The results found suggest that the proposed index meets the expectation of predicting the vulnerability of the local population.

Dam break analysis and flood inundation map of Krisak dam for emergency action plan

NASA Astrophysics Data System (ADS)

Juliastuti, Setyandito, Oki

2017-11-01

The Indonesian Regulation which refers to the ICOLD Regulation (International Committee on Large Dam required have the Emergency Action Plan (EAP) guidelines because of the dams have potential failure. In EAP guidelines there is a management of evacuation where the determination of the inundation map based on flood modeling. The purpose of the EAP is to minimize the risk of loss of life and property in downstream which caused by dam failure. This paper will describe about develop flood modeling and inundation map in Krisak dam using numerical methods through dam break analysis (DBA) using hydraulic model Zhong Xing HY-21. The approaches of dam failure simulation are overtopping and piping. Overtopping simulation based on quadrangular, triangular and trapezium fracture. Piping simulation based on cracks of orifice. Using results of DBA, hazard classification of Krisak dam is very high. The nearest village affected dam failure is Singodutan village (distance is 1.45 kilometer from dam) with inundation depth is 1.85 meter. This result can be used by stakeholders such as emergency responders and the community at risk in formulating evacuation procedure.

Flood monitoring for ungauged rivers: the power of combining space-based monitoring and global forecasting models

NASA Astrophysics Data System (ADS)

Revilla-Romero, Beatriz; Netgeka, Victor; Raynaud, Damien; Thielen, Jutta

2013-04-01

Flood warning systems typically rely on forecasts from national meteorological services and in-situ observations from hydrological gauging stations. This capacity is not equally developed in flood-prone developing countries. Low-cost satellite monitoring systems and global flood forecasting systems can be an alternative source of information for national flood authorities. The Global Flood Awareness System (GloFAS) has been develop jointly with the European Centre for Medium-Range Weather Forecast (ECMWF) and the Joint Research Centre, and it is running quasi operational now since June 2011. The system couples state-of-the art weather forecasts with a hydrological model driven at a continental scale. The system provides downstream countries with information on upstream river conditions as well as continental and global overviews. In its test phase, this global forecast system provides probabilities for large transnational river flooding at the global scale up to 30 days in advance. It has shown its real-life potential for the first time during the flood in Southeast Asia in 2011, and more recently during the floods in Australia in March 2012, India (Assam, September-October 2012) and Chad Floods (August-October 2012).The Joint Research Centre is working on further research and development, rigorous testing and adaptations of the system to create an operational tool for decision makers, including national and regional water authorities, water resource managers, hydropower companies, civil protection and first line responders, and international humanitarian aid organizations. Currently efforts are being made to link GloFAS to the Global Flood Detection System (GFDS). GFDS is a Space-based river gauging and flood monitoring system using passive microwave remote sensing which was developed by a collaboration between the JRC and Dartmouth Flood Observatory. GFDS provides flood alerts based on daily water surface change measurements from space. Alerts are shown on a world map, with detailed reports for individual gauging sites. A comparison of discharge estimates from the Global Flood Detection System (GFDS) and the Global Flood Awareness System (GloFAS) with observations for representative climatic zones is presented. Both systems have demonstrated strong potential in forecasting and detecting recent catastrophic floods. The usefulness of their combined information on global scale for decision makers at different levels is discussed. Combining space-based monitoring and global forecasting models is an innovative approach and has significant benefits for international river commissions as well as international aid organisations. This is in line with the objectives of the Hyogo and the Post-2015 Framework that aim at the development of systems which involve trans-boundary collaboration, space-based earth observation, flood forecasting and early warning.

A MODIS-based automated flood monitoring system for southeast asia

NASA Astrophysics Data System (ADS)

Ahamed, A.; Bolten, J. D.

2017-09-01

Flood disasters in Southeast Asia result in significant loss of life and economic damage. Remote sensing information systems designed to spatially and temporally monitor floods can help governments and international agencies formulate effective disaster response strategies during a flood and ultimately alleviate impacts to population, infrastructure, and agriculture. Recent destructive flood events in the Lower Mekong River Basin occurred in 2000, 2011, 2013, and 2016 (http://ffw.mrcmekong.org/historical_rec.htm, April 24, 2017). The large spatial distribution of flooded areas and lack of proper gauge data in the region makes accurate monitoring and assessment of impacts of floods difficult. Here, we discuss the utility of applying satellite-based Earth observations for improving flood inundation monitoring over the flood-prone Lower Mekong River Basin. We present a methodology for determining near real-time surface water extent associated with current and historic flood events by training surface water classifiers from 8-day, 250-m Moderate-resolution Imaging Spectroradiometer (MODIS) data spanning the length of the MODIS satellite record. The Normalized Difference Vegetation Index (NDVI) signature of permanent water bodies (MOD44W; Carroll et al., 2009) is used to train surface water classifiers which are applied to a time period of interest. From this, an operational nowcast flood detection component is produced using twice daily imagery acquired at 3-h latency which performs image compositing routines to minimize cloud cover. Case studies and accuracy assessments against radar-based observations for historic flood events are presented. The customizable system has been transferred to regional organizations and near real-time derived surface water products are made available through a web interface platform. Results highlight the potential of near real-time observation and impact assessment systems to serve as effective decision support tools for governments, international agencies, and disaster responders.

Colorado River Basin Hover Dam - Review of Flood Control Regulation.

DTIC Science & Technology

1982-07-01

plan would not adversely impact on any endangered species. 5. An archaeological analysis of the recommiended plan revealed that no cultural resources... Archaeological Resources. .. ...... ......... E-18 4. General Effect of High Flows on Fish and Wildlife Resources .. .... ...... ..... .......... E-19...E-29 5.5 Imperial Dam to the Southerly International Boundary. .. ...... ..... ...... .... E-33 5.6 Archaeological Resources

77 FR 68196 - Orders Limiting Operations at John F. Kennedy International Airport, LaGuardia Airport, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

... to an extratropical storm that caused widespread power outages, severe flooding, and severe... storm. FAA Analysis Under the FAA's High Density Rule at DCA and Orders limiting operations at LGA, JFK... area or northeastern U.S. affected by the storm. These circumstances may have created a unique hardship...

New mechanism under International Flood Initiative toward robustness for flood management in the Asia Pacific region

NASA Astrophysics Data System (ADS)

Murase, M.; Yoshitani, J.; Takeuchi, K.; Koike, T.

2015-12-01

Climate change is likely to result in increases in the frequency or intensity of extreme weather events. It is imperative that a good understanding is developed of how climate change affects the events that are reflected in hydrological extremes such as floods and how practitioners in water resources management deal with them. Since there is still major uncertainty as to how the impact of climate change affect actual water resources management, it is important to build robustness into management schemes and communities. Flood management under such variety of uncertainty favors the flexible and adaptive implementation both in top-down and bottom-up approaches. The former uses projections of global or spatially downscaled models to drive resource models and project resource impacts. The latter utilizes policy or planning tools to identify what changes in climate would be most threatening to their long-range operations. Especially for the bottom-up approaches, it is essential to identify the gap between what should be done and what has not been achieved for disaster risks. Indicators or index are appropriate tools to measure such gaps, but they are still in progress to cover the whole world. The International Flood Initiative (IFI), initiated in January 2005 by UNESCO and WMO in close cooperation with UNU and ISDR, IAHS and IAHR, has promoted an integrated approach to flood management to take advantage of floods and use of flood plains while reducing the social, environmental and economic risks. Its secretariat is located in ICHARM. The initiative objective is to support national platforms to practice evidence-based disaster risk reduction through mobilizing scientific and research networks at national, regional and international levels. The initiative is now preparing for a new mechanism to facilitate the integrated approach for flood management on the ground regionally in the Asia Pacific (IFI-AP) through monitoring, assessment and capacity building.

Prone to fix: Resilience of the active nitrogen-fixing rice root microbiome

NASA Astrophysics Data System (ADS)

Hurek, Thomas; Sabale, Mugdha; Sarkar, Abhijit; Pees, Tobias; Reinhold-Hurek, Barbara

2016-04-01

Due to water consumption, many lowland rice areas in Asia are undergoing a transition that involves adoption of new management strategies, with crop rotations encompassing a non-flooded crop, including maize. Shifting from flooded to non-flooded cropping is likely to affect microbial nitrogen cycling. For analysis of the root-associated microbiome of rice and maize in response to flooding or nitrogen fertilizer, we combine methods of microbial ecology (Next-Generation sequencing of amplicons), and a reductionist approach with pure cultures of the endophytic diazotroph Azoarus sp.. Field plots of the ICON project (Introducing non-flooded crops in rice-dominated landscapes: Impact on Carbon, nitrogen and water budgets) at the International Rice Research Institute in the Philippines were analyzed. Root-associated activity of nitrogenase gene expression was assessed by quantitative RT-PCR of nifH. For rice, expression levels were surprisingly stable, in response to non-flooded versus flooded conditions, or in response to conventional nitrogen fertilizer applications versus lack of N-fertilizer. In contrast, the active diazotrophic population of maize roots was not resistant to N-fertilization, nifH expression strongly decreased. Concordant changes in the diazotrophic resident or active communities were detected by nifH amplicon sequence analysis, based on bacterial DNA or mRNA, respectively. For high-resolution analyses of the endobiome in gnotobiotic culture, we developed a dual fluorescence reporter system for Azoarcus sp. BH72 which allows to quantify and visualize epi- and endophytic gene expression by concfocal microscopy (CLSM). This allowed us to demonstrate sites of active nitrogen fixation (gene expression) in association with rice roots. We confirmed that at low nitrogen fertilizer levels, endophytic nifH gene expression persisted in rice roots, while it was repressed in maize roots. This supports our observation of remarkable stability of nitrogen fixation in association with rice roots.

Towards a systematic approach to comparing distributions used in flood frequency analysis

NASA Astrophysics Data System (ADS)

Bobée, B.; Cavadias, G.; Ashkar, F.; Bernier, J.; Rasmussen, P.

1993-02-01

The estimation of flood quantiles from available streamflow records has been a topic of extensive research in this century. However, the large number of distributions and estimation methods proposed in the scientific literature has led to a state of confusion, and a gap prevails between theory and practice. This concerns both at-site and regional flood frequency estimation. To facilitate the work of "hydrologists, designers of hydraulic structures, irrigation engineers and planners of water resources", the World Meteorological Organization recently published a report which surveys and compares current methodologies, and recommends a number of statistical distributions and estimation procedures. This report is an important step towards the clarification of this difficult topic, but we think that it does not effectively satisfy the needs of practitioners as intended, because it contains some statements which are not statistically justified and which require further discussion. In the present paper we review commonly used procedures for flood frequency estimation, point out some of the reasons for the present state of confusion concerning the advantages and disadvantages of the various methods, and propose the broad lines of a possible comparison strategy. We recommend that the results of such comparisons be discussed in an international forum of experts, with the purpose of attaining a more coherent and broadly accepted strategy for estimating floods.

Assessing the Utility of a Satellite-Based Flood Inundation and Socio-Economic Impact Tool for the Lower Mekong River Basin

NASA Astrophysics Data System (ADS)

Ahamed, A.; Bolten, J. D.

2016-12-01

Flood disaster events in Southeast Asia result in significant loss of life and economic damage. Remote sensing information systems designed to monitor floods and assess their severity can help governments and international agencies formulate an effective response before and during flood events, and ultimately alleviate impacts to population, infrastructure, and agriculture. Recent examples of destructive flood events in the Lower Mekong River Basin occurred in 2000, 2011, and 2013. Floods can be particularly costly in the developing countries of Southeast Asia where large portions of the population live on or near the floodplain (Jonkman, 2005; Kirsch et al., 2012; Long and Trong, 2001; Stromberg. 2007). Regional studies (Knox, 1993; Mirza, 2002; Schiermeier, 2011; Västilä et al, 2010) and Intergovernmental Panel on Climate Change (IPCC, 2007) projections suggest that precipitation extremes and flood frequency are increasing. Thus, improved systems to rapidly monitor flooding in vulnerable areas are needed. This study determines surface water extent for current and historic flood events by using stacks of historic multispectral Moderate-resolution Imaging Spectroradiometer (MODIS) 250-meter imagery and the spectral Normalized Difference Vegetation Index (NDVI) signatures of permanent water bodies (MOD44W). Supporting software tools automatically assess flood impacts to population and infrastructure to provide a rapid first set of impact numbers generated hours after the onset of an event. The near real-time component uses twice daily imagery acquired at 3-hour latency, and performs image compositing routines to minimize cloud cover. Case studies for historic flood events are presented. Results suggest that near real-time remote sensing-based observation and impact assessment systems can serve as effective regional decision support tools for governments, international agencies, and disaster responders.

Internationally coordinated multi-mission planning is now critical to sustain the space-based rainfall observations needed for managing floods globally

NASA Astrophysics Data System (ADS)

Reed, Patrick M.; Chaney, Nathaniel W.; Herman, Jonathan D.; Ferringer, Matthew P.; Wood, Eric F.

2015-02-01

At present 4 of 10 dedicated rainfall observing satellite systems have exceeded their design life, some by more than a decade. Here, we show operational implications for flood management of a ‘collapse’ of space-based rainfall observing infrastructure as well as the high-value opportunities for a globally coordinated portfolio of satellite missions and data services. Results show that the current portfolio of rainfall missions fails to meet operational data needs for flood management, even when assuming a perfectly coordinated data product from all current rainfall-focused missions (i.e., the full portfolio). In the full portfolio, satellite-based rainfall data deficits vary across the globe and may preclude climate adaptation in locations vulnerable to increasing flood risks. Moreover, removing satellites that are currently beyond their design life (i.e., the reduced portfolio) dramatically increases data deficits globally and could cause entire high intensity flood events to be unobserved. Recovery from the reduced portfolio is possible with internationally coordinated replenishment of as few as 2 of the 4 satellite systems beyond their design life, yielding rainfall data coverages that outperform the current full portfolio (i.e., an optimized portfolio of eight satellites can outperform ten satellites). This work demonstrates the potential for internationally coordinated satellite replenishment and data services to substantially enhance the cost-effectiveness, sustainability and operational value of space-based rainfall observations in managing evolving flood risks.

Surveyor V: Discussion of chemical analysis

USGS Publications Warehouse

Gault, D.E.; Adams, J.B.; Collins, R.J.; Green, J.; Kuiper, G.P.; Mazursky, H.; O'Keefe, J. A.; Phinney, R.A.; Shoemaker, E.M.

1967-01-01

Material of basaltic composition at the Surveyor V landing site implies that differentiation has occurred in the moon, probably due to internal sources of heat. The results are consistent with the hypothesis that extensive volcanic flows have been responsible for flooding and filling the mare basins. The processes and products of lunar magmatic activity are apparently similar to those of the earth.

Surveyor v: discussion of chemical analysis.

PubMed

Gault, D E; Adams, J B; Collins, R J; Green, J; Kuiper, G P; Mazursky, H; O'keefe, J A; Phinney, R A; Shoemaker, E M

1967-11-03

Material of basaltic composition at the Surveyor V landing site implies that differentiation has occurred in the moon, probably due to internal sources of heat. The results are consistent with the hypothesis that extensive volcanic flows have been responsible for flooding and filling the mare basins. The processes and products of lunar magmatic activity are apparently similar to those of the earth.

Environmental Assessment for Extension of Runways at Charleston International Airport and Charleston Air Force Base, Charleston, South Carolina

DTIC Science & Technology

2008-09-03

NAAQS NEPA NFA NFIP NMFS NPDES NRCS NRHP OCRM PM ppm PSD RCRA SCDAH SCDHEC SCDNR SHPO SIP SOP SPCC SWMU SWPPP T&E TNW tpy TSP...standard hazard insurance. Communities that participate in the National Flood Insurance Program ( NFIP ) require all properties in a flood zone to have...supplemental flood insurance. Charleston County is a 25 participant in the NFIP . Development activities in and near flood zones require that

Initial Results in Global Flood Monitoring System (GFMS) Using GPM Data

NASA Astrophysics Data System (ADS)

Wu, H.; Adler, R. F.; Kirschbaum, D.; Huffman, G. J.; Tian, Y.

2016-12-01

The Global Flood Monitoring System (GFMS) (http://flood.umd.edu) has been developed and used to provide real-time flood detection and streamflow estimates over the last few years with significant success shown by validation against global flood event data sets and observed streamflow variations. It has become a tool for various national and international organizations to appraise flood conditions in various areas, including where rainfall and hydrology information is limited. The GFMS has been using the TRMM Multi-satellite Precipitation Analysis (TMPA) as its main rainfall input. Now, with the advent of NASA's Global Precipitation Measurement (GPM) mission there is an opportunity to significantly improve global flood monitoring and forecasting. GPM's Integrated Multi-satellitE Retrievals for GPM (IMERG) multi-satellite product is designed to take advantage of various technical advances in the field and combine that with an efficient processing system producing "early" (4 hrs) and "late" (12 hrs) products for operational use. The products are also more uniform in results than TMPA among the various satellites going into the analysis and available at finer time and space resolutions. On the road to replacing TMPA with the IMERG in the operational version of the GFMS parallel systems were run for periods to understand the impact of the new type of data on the streamflow and flood estimates. Results of this comparison are the basis for this presentation. It is expected that an improvement will be noted both in the accuracy of the precipitation estimates and a smoother transition in and out of heavy rain events, helping to reduce "shock" in the hydrology model. The finer spatial resolution should also help in this regard. The GFMS will be initially run at its primary resolution of 1/8th degree latitude/longitude with both data sets to isolate the impact of the rain information change. Other aspects will also be examined, including higher latitude events, where GPM precipitation algorithms should also provide improvements. This initial work will help focus full implementation of the IMERG into GFMS and the retrospective calculations to be done for the full TRMM/GPM era.

Street floods in Metro Manila and possible solutions.

PubMed

Lagmay, Alfredo Mahar; Mendoza, Jerico; Cipriano, Fatima; Delmendo, Patricia Anne; Lacsamana, Micah Nieves; Moises, Marc Anthony; Pellejera, Nicanor; Punay, Kenneth Niño; Sabio, Glenn; Santos, Laurize; Serrano, Jonathan; Taniza, Herbert James; Tingin, Neil Eneri

2017-09-01

Urban floods from thunderstorms cause severe problems in Metro Manila due to road traffic. Using Light Detection and Ranging (LiDAR)-derived topography, flood simulations and anecdotal reports, the root of surface flood problems in Metro Manila is identified. Majority of flood-prone areas are along the intersection of creeks and streets located in topographic lows. When creeks overflow or when rapidly accumulated street flood does not drain fast enough to the nearest stream channel, the intersecting road also gets flooded. Possible solutions include the elevation of roads or construction of well-designed drainage structures leading to the creeks. Proposed solutions to the flood problem of Metro Manila may avoid paralyzing traffic problems due to short-lived rain events, which according to Japan International Cooperation Agency (JICA) cost the Philippine economy 2.4billionpesos/day. Copyright © 2017. Published by Elsevier B.V.

Continuous hydrologic simulation and flood-frequency, hydraulic, and flood-hazard analysis of the Blackberry Creek watershed, Kane County, Illinois

USGS Publications Warehouse

Soong, David T.; Straub, Timothy D.; Murphy, Elizabeth A.

2006-01-01

Results of hydrologic model, flood-frequency, hydraulic model, and flood-hazard analysis of the Blackberry Creek watershed in Kane County, Illinois, indicate that the 100-year and 500-year flood plains range from approximately 25 acres in the tributary F watershed (a headwater subbasin at the northeastern corner of the watershed) to almost 1,800 acres in Blackberry Creek main stem. Based on 1996 land-cover data, most of the land in the 100-year and 500-year flood plains was cropland, forested and wooded land, and grassland. A relatively small percentage of urban land was in the flood plains. The Blackberry Creek watershed has undergone rapid urbanization in recent decades. The population and urbanized lands in the watershed are projected to double from the 1990 condition by 2020. Recently, flood-induced damage has occurred more frequently in urbanized areas of the watershed. There are concerns about the effect of urbanization on flood peaks and volumes, future flood-mitigation plans, and potential effects on the water quality and stream habitats. This report describes the procedures used in developing the hydrologic models, estimating the flood-peak discharge magnitudes and recurrence intervals for flood-hazard analysis, developing the hydraulic model, and the results of the analysis in graphical and tabular form. The hydrologic model, Hydrological Simulation Program-FORTRAN (HSPF), was used to perform the simulation of continuous water movements through various patterns of land uses in the watershed. Flood-frequency analysis was applied to an annual maximum series to determine flood quantiles in subbasins for flood-hazard analysis. The Hydrologic Engineering Center-River Analysis System (HEC-RAS) hydraulic model was used to determine the 100-year and 500-year flood elevations, and to determine the 100-year floodway. The hydraulic model was calibrated and verified using high water marks and observed inundation maps for the July 17-18, 1996, flood event. Digital maps of the 100-year and 500-year flood plains and the 100-year floodway for each tributary and the main stem of Blackberry Creek were compiled.

Hydrologic, Hydraulic, and Flood Analyses of the Blackberry Creek Watershed, Kendall County, Illinois

USGS Publications Warehouse

Murphy, Elizabeth A.; Straub, Timothy D.; Soong, David T.; Hamblen, Christopher S.

2007-01-01

Results of the hydrologic model, flood-frequency, hydraulic model, and flood-hazard analysis of the Blackberry Creek watershed in Kendall County, Illinois, indicate that the 100-year and 500-year flood plains cover approximately 3,699 and 3,762 acres of land, respectively. On the basis of land-cover data for 2003, most of the land in the flood plains was cropland and residential land. Although many acres of residential land were included in the flood plain, this land was mostly lawns, with 25 homes within the 100-year flood plain, and 41 homes within the 500-year flood plain in the 2003 aerial photograph. This report describes the data collection activities to refine the hydrologic and hydraulic models used in an earlier study of the Kane County part of the Blackberry Creek watershed and to extend the flood-frequency analysis through water year 2003. The results of the flood-hazard analysis are presented in graphical and tabular form. The hydrologic model, Hydrological Simulation Program - FORTRAN (HSPF), was used to simulate continuous water movement through various land-use patterns in the watershed. Flood-frequency analysis was applied to an annual maximum series to determine flood quantiles in subbasins for flood-hazard analysis. The Hydrologic Engineering Center- River Analysis System (HEC-RAS) hydraulic model was used to determine the 100-year and 500-year flood elevations, and the 100-year floodway. The hydraulic model was calibrated and verified using observations during three storms at two crest-stage gages and the U.S. Geological Survey streamflowgaging station near Yorkville. Digital maps of the 100-year and 500-year flood plains and the 100-year floodway for each tributary and the main stem of Blackberry Creek were compiled.

The Emergence of Flood Insurance in Canada: Navigating Institutional Uncertainty.

PubMed

Thistlethwaite, Jason

2017-04-01

Flood insurance has remained unavailable in Canada based on an assessment that it lacks economic viability. In response to Canada's costliest flood event to date in 2013, the Canadian insurance industry has started to develop a framework to expand existing property insurance to cover flood damage. Research on flood insurance has overlooked why and how insurance systems transition to expand insurance coverage without evidence of economic viability. This article will address this gap through a case study on the emergence of flood insurance in Canada, and the approach to its expansion. Between 2013 and 2016, insurance industry officials representing over 60% of premiums collected in Canada were interviewed. These interviews revealed that flood insurance is being expanded in response to institutional pressure, specifically external stakeholder expectations that the insurance industry will adopt a stronger role in managing flood risk through coverage of flood damage. Further evidence of this finding is explored by assessing the emergence of a unique flood insurance model that involves a risk-adjusted and optional product along with an expansion of government policy supporting flood risk mitigation. This approach attempts to balance industry concerns about economic viability with institutional pressure to reduce flood risk through insurance. This analysis builds on existing research by providing the first scholarly analysis of flood insurance in Canada, important "empirical" teeth to existing conceptual analysis on the availability of flood insurance, and the influence of institutional factors on risk analysis within the insurance sector. © 2016 Society for Risk Analysis.

Climate-driven trends in the occurrence of major floods across North America and Europe

NASA Astrophysics Data System (ADS)

Hodgkins, Glenn A.; Whitfield, Paul H.; Burn, Donald H.; Hannaford, Jamie; Renard, Benjamin; Stahl, Kerstin; Fleig, Anne K.; Madsen, Henrik; Mediero, Luis; Korhonen, Johanna; Murphy, Conor; Crochet, Philippe; Wilson, Donna

2016-04-01

Every year river floods cause enormous damage around the world. Recent major floods in North America and Europe, for example, have received much press, with some concluding that these floods are more frequent in recent years as a result of anthropogenic warming. There has been considerable scientific effort invested in establishing whether observed flood records show evidence of trends or variability in flood frequency, and to determine whether these patterns can be linked to climatic changes. However, the river catchments used in many published studies are influenced by direct human alteration such as reservoir regulation and urbanisation, which can confound the interpretation of climate-driven variability. Furthermore, a majority of previous studies have analysed changes in low magnitude floods, such as the annual peak flow, at a national scale. Few studies are known that have analysed changes in large floods (greater than 25-year floods) on a continental scale. To fill this research gap, we present a study analysing flood flows from reference hydrologic networks (RHNs) or RHN-like gauges across a large study domain embracing North America and much of Europe. RHNs comprise gauging stations with minimally disturbed catchment conditions, which have a near-natural flow regime and provide good quality data; RHN analyses thus allow hydro-climatic variability to be distinguished from direct artificial disturbances or data inhomogeneities. One of the key innovations in this study is the definition of an RHN-like network consisting of 1204 catchments on a continental scale. The network incorporates existing, well-established RHNs in Canada, the US, the UK, Ireland and Norway, alongside RHN-like catchments from Europe (France, Switzerland, Iceland, Denmark, Sweden, Finland, Spain), which have been incorporated in the network following a major effort to ensure RHN-like status of candidate gauges through consultation with local experts. As the aim of the study is to examine long-term variability in the number of major floods, annual exceedances of 25-, 50-, and 100-year floods during the last 50 - 80 years are estimated for all study gauges across North America and Europe, and for smaller groups of gauges defined by catchment size, location, climate, flood threshold, and period of record. Trends are computed using logistic regression techniques, supported by a suite of methods used to test the assumptions used in the analysis. We also analyse relationships between major flood occurrence and atmosphere/ocean indices (the AMO, NAO, PDO and SOI). Our analysis finds no compelling evidence for consistent changes over time in major-flood occurrence across North America and Europe, indicating that generalizations about major-flood occurrence trends across large domains or a diversity of catchment types are ungrounded. There are in fact more significant relationships between major-flood occurrence and the AMO than between flood occurrence and time. Flood occurrence overall (based on data from all 1204 gauges in our study) increased from 1961 to 2010 but not significantly, driven primarily by European increases. Non-significant increases were also found overall from 1931 to 2010 (322 gauges) but driven primarily by North American increases. Flood occurrence increased and decreased (including some significant changes) for the various sub-groups of gauges. Overall this study demonstrates that past changes in major-flood occurrence are highly complex and future changes will be likewise. International hydrologic networks containing minimally altered catchments will play a key role in understanding these complexities.

Scientific developments ISFD3

USGS Publications Warehouse

Schropp, M.H.I.; Soong, T.W.

2006-01-01

Highlights, trends, and consensus from the 63 papers submitted to the Scientific Developments theme of the Third International Symposium on Flood Defence (ISFD) are presented. Realizing that absolute protection against flooding can never be guaranteed, trends in flood management have shifted: (1) from flood protection to flood-risk management, (2) from reinforcing structural protection to lowering flood levels, and (3) to sustainable management through integrated problem solving. Improved understanding of watershed responses, climate changes, applications of GIS and remote-sensing technologies, and advanced analytical tools appeared to be the driving forces for renewing flood-risk management strategies. Technical competence in integrating analytical tools to form the basin wide management systems are demonstrated by several large, transnation models. However, analyses from social-economic-environmental points of view are found lag in general. ?? 2006 Taylor & Francis Group.

Improving Flood Forecasting in International River Basins

NASA Astrophysics Data System (ADS)

Hossain, Faisal; Katiyar, Nitin

2006-01-01

In flood-prone international river basins (IRBs), many riparian nations that are located close to a basin's outlet face a major problem in effectively forecasting flooding because they are unable to assimilate in situ rainfall data in real time across geopolitical boundaries. NASA's proposed Global Precipitation Measurement (GPM) mission, which is expected to begin in 2010, will comprise high-resolution passive microwave (PM) sensors (at resolution ~3-6 hours, 10 × 10 square kilometers) that may provide new opportunities to improve flood forecasting in these river basins. Research is now needed to realize the potential of GPM. With adequate research in the coming years, it may be possible to identify the specific IRBs that would benefit cost-effectively from a preprogrammed satellite-based forecasting system in anticipation of GPM. Acceleration of such a research initiative is worthwhile because it could reduce the risk of the cancellation of GPM [see Zielinski, 2005].

Earth Observation

NASA Image and Video Library

2012-07-10

ISS032-E-006129 (10 July 2012) --- Flooding in Krymsk in the Krasnodar region of southern Russia is featured in this image photographed by an Expedition 32 crew member on the International Space Station. On the night of July 7, 2012 a major storm dumped more than a foot of water on the southern Russian area of Krasnodar, near the Black Sea. The resulting flood was likened to a tsunami, and to date, more than 170 people died, most from the city of Krymsk. The Moscow times reports that more than 19,000 people lost everything. This image taken by cosmonauts aboard the space station shows the city of Krymsk. The tan-colored areas indicate some of the regions that were flooded; the color is probably due to the mud and debris that were left by the floodwaters. Krymsk is located in the western foothills on the northern slope of the Caucasus Mountains?a range that stretches between the Black Sea and the Caspian Sea. The vast amount of rain quickly overwhelmed the small river channels that flow northward from the mountains to the Russian lowlands and the Kuban River; Krymsk, located on one of those tributaries, was directly in the pathway of the flash flood. As part of the international partner agreement to use the International Space Station to benefit humanity, crew members and other Earth observing instruments provide best-effort support to the International Disaster Charter (IDC) when it is activated by collecting imagery of areas on the ground impacted by natural events such as the flooding in Krymsk. This image was acquired July 10, 2012 in response to the IDC activation.

Rapid Flood Map Generation from Spaceborne SAR Observations

NASA Astrophysics Data System (ADS)

Yun, S. H.; Liang, C.; Manipon, G.; Jung, J.; Gurrola, E. M.; Owen, S. E.; Hua, H.; Agram, P. S.; Webb, F.; Sacco, G. F.; Rosen, P. A.; Simons, M.

2016-12-01

The Advanced Rapid Imaging and Analysis (ARIA) team has responded to the January 2016 US Midwest Floods along the Mississippi River. Daily teleconferences with FEMA, NOAA, NGA, and USGS, provided information on precipitation and flood crest migration, based on which we coordinated with the Japanese Aerospace Exploration Agency (JAXA) through NASA headquarters for JAXA's ALOS-2 timely tasking over two paths. We produced flood extent maps using ALOS-2 SM3 mode Level 1.5 data that were provided through the International Charter and stored at the US Geological Survey's Hazards Data Distribution System (HDDS) archive. On January 6, the first four frames (70 km x 240 km) were acquired, which included the City of Memphis. We registered post-event SAR images to pre-event images, applied radiometric calibration, took a logarithm of the ratio of the two images. Two thresholds were applied to represent flooded areas that became open water (colored in blue) and flooded areas with tall vegetation (colored in red). The second path was acquired on January 11 further down along the Mississippi River. Seven frames (70 km x 420 km) were acquired and flood maps were created in the similar fashion. The maps were delivered to the FEMA as well as posted on ARIA's public website. The FEMA stated that SAR provides inspection priority for optical imagery and ground response. The ALOS-2 data and the products have been a very important source of information during this response as the flood crest has moved down stream. The SAR data continue to be an important resource during times when optical observations are often not useful. In close collaboration with FEMA and USGS, we also work on other flood events including June 2016 China Floods using European Space Agency's (ESA's) Sentienl-1 data, to produce flood extent maps and identify algorithmic needs and ARIA system's requirements to automate and rapidly produce and deliver flood maps for future events. With the addition of Sentinel-1B satellite, the composite expected wait time until a SAR satellite to fly over a flooded area became smaller than 12 hours. With more SAR missions, such as SAOCOM, RADARSAT Constellation, Sentinel-1C/D, ALOS-3, and NISAR, SAR data are becoming more useful for rapid mapping of devastating floods, which are becoming more frequent and more severe around the world.

Correlation between high resolution sequence stratigraphy and mechanical stratigraphy for enhanced fracture characteristic prediction

NASA Astrophysics Data System (ADS)

Al Kharusi, Laiyyan M.

Sequence stratigraphy relates changes in vertical and lateral facies distribution to relative changes in sea level. These relative changes in carbonates effect early diagenesis, types of pores, cementation and dissolution patterns. As a result, in carbonates, relative changes in sea level significantly impact the lithology, porosity, diagenesis, bed and bounding surfaces which are all factors that control fracture patterns. This study explores these relationships by integrating stratigraphy with fracture analysis and petrophysical properties. A special focus is given to the relationship between mechanical boundaries and sequence stratigraphic boundaries in three different settings: (1) Mississippian strata in Sheep Mountain Anticline, Wyoming, (2) Mississippian limestones in St. Louis, Missouri, and (3) Pennsylvanian limestones intermixed with elastics in the Paradox Basin, Utah. The analysis of these sections demonstrate that a fracture hierarchy exists in relation to the sequence stratigraphic hierarchy. The majority of fractures (80%) terminate at genetic unit boundaries or the internal flooding surface that separates the transgressive from regressive hemicycle. Fractures (20%) that do not terminate at genetic unit boundaries or their internal flooding surface terminate at lower order sequence stratigraphic boundaries or their internal flooding surfaces. Secondly, the fracture spacing relates well to bed thickness in mechanical units no greater than 0.5m in thickness but with increasing bed thickness a scatter from the linear trend is observed. In the Paradox Basin the influence of strain on fracture density is illustrated by two sections measured in different strain regimes. The folded strata at Raplee Anticline has higher fracture densities than the flat-lying beds at the Honaker Trail. Cemented low porosity rocks in the Paradox Basin do not show a correlation between fracture pattern and porosity. However velocity and rock stiffness moduli's display a slight correlation to fracture spacing. Furthermore, bed thickness is found to be only one factor in determining fracture density but with increasing strain, internal bedforms and rock petrophysical heterogeneities influence fracture density patterns. This study illustrates how integrating sedimentologic and sequence stratigraphic interpretations with data on structural kinematics can lead to refined predictive understanding of fracture attributes.

A joint probability approach for coincidental flood frequency analysis at ungauged basin confluences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Cheng

2016-03-12

A reliable and accurate flood frequency analysis at the confluence of streams is of importance. Given that long-term peak flow observations are often unavailable at tributary confluences, at a practical level, this paper presents a joint probability approach (JPA) to address the coincidental flood frequency analysis at the ungauged confluence of two streams based on the flow rate data from the upstream tributaries. One case study is performed for comparison against several traditional approaches, including the position-plotting formula, the univariate flood frequency analysis, and the National Flood Frequency Program developed by US Geological Survey. It shows that the results generatedmore » by the JPA approach agree well with the floods estimated by the plotting position and univariate flood frequency analysis based on the observation data.« less

Flood of April and May 2008 in Northern Maine

USGS Publications Warehouse

Lombard, Pamela J.

2010-01-01

Severe flooding occurred in Aroostook and Penobscot Counties in northern Maine between April 28 and May 1, 2008, and damage was extensive in the town of Fort Kent. Aroostook County was declared a Federal disaster area on May 9, and the declaration was expanded to include Penobscot County on May 16-qualifying the entire region for federal assistance. Water in the St. John River peaked at 30.17 feet in Fort Kent (5 feet above flood stage), hit the low steel of the International Bridge connecting Fort Kent to New Brunswick, caused closure of international bridges in Fort Kent, Van Buren, and Hamlin and came within inches of the top of a 30-foot-high earthen dike constructed to protect the downtown area of Fort Kent. Longterm streamgages with 25 to 84 years of record on the Big Black, St. John, Allagash, Fish, and Aroostook Rivers recorded maximum streamflows for their respective periods of record. Northern Maine experienced major floods in 1923, 1973, 1974, 1979, and 1983 (Maloney and Bartlett, 1991). All of these floods were in late April or early May when heavy rain combined with snowmelt runoff.

Estimating design flood and HEC-RAS modelling approach for flood analysis in Bojonegoro city

NASA Astrophysics Data System (ADS)

Prastica, R. M. S.; Maitri, C.; Hermawan, A.; Nugroho, P. C.; Sutjiningsih, D.; Anggraheni, E.

2018-03-01

Bojonegoro faces flood every year with less advanced prevention development. Bojonegoro city development could not peak because the flood results material losses. It affects every sectors in Bojonegoro: education, politics, economy, social, and infrastructure development. This research aims to analyse and to ensure that river capacity has high probability to be the main factor of flood in Bojonegoro. Flood discharge analysis uses Nakayasu synthetic unit hydrograph for period of 5 years, 10 years, 25 years, 50 years, and 100 years. They would be compared to the water maximum capacity that could be loaded by downstream part of Bengawan Solo River in Bojonegoro. According to analysis result, Bengawan Solo River in Bojonegoro could not able to load flood discharges. Another method used is HEC-RAS analysis. The conclusion that shown by HEC-RAS analysis has the same view. It could be observed that flood water loading is more than full bank capacity elevation in the river. To conclude, the main factor that should be noticed by government to solve flood problem is river capacity.

Ethylene-Mediated Acclimations to Flooding Stress1

PubMed Central

Sasidharan, Rashmi; Voesenek, Laurentius A.C.J.

2015-01-01

Flooding is detrimental for plants, primarily because of restricted gas exchange underwater, which leads to an energy and carbohydrate deficit. Impeded gas exchange also causes rapid accumulation of the volatile ethylene in all flooded plant cells. Although several internal changes in the plant can signal the flooded status, it is the pervasive and rapid accumulation of ethylene that makes it an early and reliable flooding signal. Not surprisingly, it is a major regulator of several flood-adaptive plant traits. Here, we discuss these major ethylene-mediated traits, their functional relevance, and the recent progress in identifying the molecular and signaling events underlying these traits downstream of ethylene. We also speculate on the role of ethylene in postsubmergence recovery and identify several questions for future investigations. PMID:25897003

Estimating flood discharge using witness movies in post-flood hydrological surveys

NASA Astrophysics Data System (ADS)

Le Coz, Jérôme; Hauet, Alexandre; Le Boursicaud, Raphaël; Pénard, Lionel; Bonnifait, Laurent; Dramais, Guillaume; Thollet, Fabien; Braud, Isabelle

2015-04-01

The estimation of streamflow rates based on post-flood surveys is of paramount importance for the investigation of extreme hydrological events. Major uncertainties usually arise from the absence of information on the flow velocities and from the limited spatio-temporal resolution of such surveys. Nowadays, after each flood occuring in populated areas home movies taken from bridges, river banks or even drones are shared by witnesses through Internet platforms like YouTube. Provided that some topography data and additional information are collected, image-based velocimetry techniques can be applied to some of these movie materials, in order to estimate flood discharges. As a contribution to recent post-flood surveys conducted in France, we developed and applied a method for estimating velocities and discharges based on the Large Scale Particle Image Velocimetry (LSPIV) technique. Since the seminal work of Fujita et al. (1998), LSPIV applications to river flows were reported by a number of authors and LSPIV can now be considered a mature technique. However, its application to non-professional movies taken by flood witnesses remains challenging and required some practical developments. The different steps to apply LSPIV analysis to a flood home movie are as follows: (i) select a video of interest; (ii) contact the author for agreement and extra information; (iii) conduct a field topography campaign to georeference Ground Control Points (GCPs), water level and cross-sectional profiles; (iv) preprocess the video before LSPIV analysis: correct lens distortion, align the images, etc.; (v) orthorectify the images to correct perspective effects and know the physical size of pixels; (vi) proceed with the LSPIV analysis to compute the surface velocity field; and (vii) compute discharge according to a user-defined velocity coefficient. Two case studies in French mountainous rivers during extreme floods are presented. The movies were collected on YouTube and field topography surveys were achieved. Identifying fixed GCPs is more difficult in rural environments than in urban areas. Image processing was performed using free software only, especially Fudaa-LSPIV (Le Coz et al., 2014) was used for steps (v), (vi), and (vii). The results illustrate the typical issues and advantages of flood home movies taken by witnesses for improving post-flood discharge estimation. In spite of the non-ideal conditions related to such movies, the LSPIV technique was successfully applied. Corrections for lens distortion and limited camera movements (shake) are not difficult to achieve. Locating precisely the video viewpoint is often easy whereas precise timing may be not, especially when the author cannot be contacted or when the camera clock is false. Based on sensitivity analysis, the determination of the water level appears to be the main source of uncertainty in the results. Nevertheless, the information content of the results remains highly valuable for post-flood studies, in particular for improving the high-flow extrapolation of hydrometric rating curves. This kind of application opens interesting avenues for participative research in flood hydrology, as well as the study of other extreme geophysical events. Typically, as part of the FloodScale ANR research project (2012-2015), specific communication actions have been focused on the determination of flood discharges within the Ardèche river catchement (France) using home movies shared by observers and volunteers. Safety instructions and a simplified field procedure were shared through local media and were made available in French and English on the project website. This way, simple flood observers or even some enthusiastic flood chasers can contribute to participative hydrological science in the same way the so-called storm chasers have significantly contributed to meteorological science since the Tornado Intercept Project (1972). Website : http://floodscale.irstea.fr/donnees-en/videos-amateurs-de-rivieres-en-crue/ Fujita, I., Muste, M., and Kruger, A. (1998). Large-scale particle image velocimetry for flow analysis in hydraulic engineering applications. Journal of Hydraulic Research, 36(3):397-414. Le Coz, J., Jodeau, M., Hauet, A., Marchand, B., Le Boursicaud, R. (2014). Image-based velocity and discharge measurements in field and laboratory river engineering studies using the free FUDAA-LSPIV software, Proceedings of the International Conference on Fluvial Hydraulics, RIVER FLOW 2014, 1961-1967.

The USGS National Streamflow Information Program and the importance of preserving long-term streamgages

USGS Publications Warehouse

Hodgkins, Glenn A.; Norris, J. Michael; Lent, Robert M.

2014-01-01

Long-term streamflow information is critical for use in several water-related areas that are important to humans and wildlife, including water management, computation of flood and drought flows for water infrastructure, and analysis of climate-related trends. Specific uses are many and diverse and range from informing water rights across state and international boundaries to designing dams and bridges.

A fluvial and pluvial probabilistic flood hazard analysis for Can Tho city, Vietnam

NASA Astrophysics Data System (ADS)

Apel, Heiko; Martinez, Oriol; Thi Chinh, Do; Viet Dung, Nguyen

2014-05-01

Can Tho city is the largest city and the economic heart of the Mekong Delta, Vietnam. Due to its economic importance and envisaged development goals the city grew rapidly in population size and extend over the last two decades. Large parts of the city are located in flood prone areas, and also the central parts of the city recently experienced an increasing number of flood events, both of fluvial and pluvial nature. As the economic power and asset values are constantly increasing, this poses a considerable risk for the city. The the aim of this study is to perform a flood hazard analysis considering both fluvial and pluvial floods and to derive probabilistic flood hazard maps. This requires in a first step an understanding of the typical flood mechanisms. Fluvial floods are triggered by a coincidence of high water levels during the annual flood period in the Mekong Delta with high tidal levels, which cause in combination short term inundations in Can Tho. Pluvial floods are triggered by typical tropical convective rain storms during the monsoon season. These two flood pathways are essentially independent in its sources and can thus be treated in the hazard analysis accordingly. For the fluvial hazard analysis we propose a bivariate frequency analysis of the Mekong flood characteristics, the annual maximum flood discharge Q and the annual flood volume V at the upper boundary of the Mekong Delta, the gauging station Kratie. This defines probabilities of exceedance of different Q-V pairs, which are transferred into synthetic flood hydrographs. The synthetic hydrographs are routed through a quasi-2D hydrodynamic model of the entire Mekong Delta in order to provide boundary conditions for a detailed hazard mapping of Can Tho. This downscaling step is necessary, because the huge complexity of the river and channel network does not allow for a proper definition of boundary conditions for Can Tho city by gauge data alone. In addition the available gauge data around Can Tho are too short for a meaningful frequency analysis. The detailed hazard mapping is performed by a 2D hydrodynamic model for Can Tho city. As the scenarios are derived in a Monte-Carlo framework, the final flood hazard maps are probabilistic, i.e. show the median flood hazard along with uncertainty estimates for each defined level of probabilities of exceedance. For the pluvial flood hazard a frequency analysis of the hourly rain gauge data of Can Tho is performed implementing a peak-over-threshold procedure. Based on this frequency analysis synthetic rains storms are generated in a Monte-Carlo framework for the same probabilities of exceedance as in the fluvial flood hazard analysis. Probabilistic flood hazard maps were then generated with the same 2D hydrodynamic model for the city. In a last step the fluvial and pluvial scenarios are combined assuming independence of the events. These scenarios were also transferred into hazard maps by the 2D hydrodynamic model finally yielding combined fluvial-pluvial probabilistic flood hazard maps for Can Tho. The derived set of maps may be used for an improved city planning or a flood risk analysis.

Extreme precipitation and floods in the Iberian Peninsula and its socio-economic impacts

NASA Astrophysics Data System (ADS)

Ramos, A. M.; Pereira, S.; Trigo, R. M.; Zêzere, J. L.

2017-12-01

Extreme precipitation events in the Iberian Peninsula can induce floods and landslides that have often major socio-economic impacts. The DISASTER database gathered the basic information on past floods and landslides that caused social consequences in Portugal for the period 1865-2015. This database was built under the assumption that social consequences of floods and landslides are sufficient relevant to be reported by newspapers, that provide the data source. Three extreme historical events were analysed in detail taking into account their associated wide socio-economic impacts. The December 1876 record precipitation and flood event leading to an all-time record flow in two large international rivers (Tagus and Guadiana). As a direct consequence, several Portuguese and Spanish towns and villages located in the banks of both rivers suffered serious flood damage on 7 December 1876. The 20-28 December 1909 event recorded the highest number of flood and landslide cases that occurred in Portugal in the period 1865-2015, having triggered the highest floods in 200 years at the Douro river's mouth and causing 89 fatalities in both Portugal and Spain northern regions. More recently the deadliest flash-flooding event affecting Portugal since, at least, the early 19th century, took place on the 25 and 26 November 1967 causing more than 500 fatalities in the Lisbon region. We provide a detailed analysis of each of these events, including their human impacts, precipitation analyses based on historical datasets and the associated atmospheric circulation conditions from reanalysis datasets. Acknowledgements: This work was supported by the project FORLAND - Hydrogeomorphologic risk in Portugal: driving forces and application for land use planning [PTDC / ATPGEO / 1660/2014] funded by the Portuguese Foundation for Science and Technology (FCT), Portugal. A. M. Ramos was also supported by a FCT postdoctoral grant (FCT/DFRH/ SFRH/BPD/84328/2012). The financial support for attending this workshop was also possible through FCT project UID/GEO/50019/2013 - Instituto Dom Luiz.

An Integrated Urban Flood Analysis System in South Korea

NASA Astrophysics Data System (ADS)

Moon, Young-Il; Kim, Min-Seok; Yoon, Tae-Hyung; Choi, Ji-Hyeok

2017-04-01

Due to climate change and the rapid growth of urbanization, the frequency of concentrated heavy rainfall has caused urban floods. As a result, we studied climate change in Korea and developed an integrated flood analysis system that systematized technology to quantify flood risk and flood forecasting in urban areas. This system supports synthetic decision-making through real-time monitoring and prediction on flash rain or short-term rainfall by using radar and satellite information. As part of the measures to deal with the increase of inland flood damage, we have found it necessary to build a systematic city flood prevention system that systematizes technology to quantify flood risk as well as flood forecast, taking into consideration both inland and river water. This combined inland-river flood analysis system conducts prediction on flash rain or short-term rainfall by using radar and satellite information and performs prompt and accurate prediction on the inland flooded area. In addition, flood forecasts should be accurate and immediate. Accurate flood forecasts signify that the prediction of the watch, warning time and water level is precise. Immediate flood forecasts represent the forecasts lead time which is the time needed to evacuate. Therefore, in this study, in order to apply rainfall-runoff method to medium and small urban stream for flood forecasts, short-term rainfall forecasting using radar is applied to improve immediacy. Finally, it supports synthetic decision-making for prevention of flood disaster through real-time monitoring. Keywords: Urban Flood, Integrated flood analysis system, Rainfall forecasting, Korea Acknowledgments This research was supported by a grant (16AWMP-B066744-04) from Advanced Water Management Research Program (AWMP) funded by Ministry of Land, Infrastructure and Transport of Korean government.

National Program for Inspection of Non-Federal Dams, Goose Pond Dam (NH 00101), Connecticut River Basin, Keene, New Hampshire. Phase I Inspection Report.

DTIC Science & Technology

1980-02-01

exceeded by floods _ greater than 6 percent of the Probable Maximum Flood ( PKF ), the test flood for spillway adequacy. Our screening criteria specifies...capacity at the top of the * dam (elevation 637) is 195 cfs or six percent of the routed O . Test Flood peak outflow. The dam is in FAIR condition at the...environment of the structure. It is .important to note that the condition of a dam depends on numerous and constantly changing internal and external

Improving Flood Risk Management for California's Central Valley: How the State Developed a Toolbox for Large, System-wide Studies

NASA Astrophysics Data System (ADS)

Pingel, N.; Liang, Y.; Bindra, A.

2016-12-01

More than 1 million Californians live and work in the floodplains of the Sacramento-San Joaquin Valley where flood risks are among the highest in the nation. In response to this threat to people, property and the environment, the Department of Water Resources (DWR) has been called to action to improve flood risk management. This has transpired through significant advances in development of flood information and tools, analysis, and planning. Senate Bill 5 directed DWR to prepare the Central Valley Flood Protection Plan (CVFPP) and update it every 5 years. A key component of this aggressive planning approach is answering the question: What is the current flood risk, and how would proposed improvements change flood risk throughout the system? Answering this question is a substantial challenge due to the size and complexity of the watershed and flood control system. The watershed is roughly 42,000 sq mi, and flows are controlled by numerous reservoirs, bypasses, and levees. To overcome this challenge, the State invested in development of a comprehensive analysis "tool box" through various DWR programs. Development of the tool box included: collection of hydro-meteorological, topographic, geotechnical, and economic data; development of rainfall-runoff, reservoir operation, hydraulic routing, and flood risk analysis models; and development of specialized applications and computing schemes to accelerate the analysis. With this toolbox, DWR is analyzing flood hazard, flood control system performance, exposure and vulnerability of people and property to flooding, consequence of flooding for specific events, and finally flood risk for a range of CVFPP alternatives. Based on the results, DWR will put forward a State Recommended Plan in the 2017 CVFPP. Further, the value of the analysis tool box extends beyond the CVFPP. It will serve as a foundation for other flood studies for years to come and has already been successfully applied for inundation mapping to support emergency response, reservoir operation analysis, and others.

A non-stationary cost-benefit analysis approach for extreme flood estimation to explore the nexus of 'Risk, Cost and Non-stationarity'

NASA Astrophysics Data System (ADS)

Qi, Wei

2017-11-01

Cost-benefit analysis is commonly used for engineering planning and design problems in practice. However, previous cost-benefit based design flood estimation is based on stationary assumption. This study develops a non-stationary cost-benefit based design flood estimation approach. This approach integrates a non-stationary probability distribution function into cost-benefit analysis, and influence of non-stationarity on expected total cost (including flood damage and construction costs) and design flood estimation can be quantified. To facilitate design flood selections, a 'Risk-Cost' analysis approach is developed, which reveals the nexus of extreme flood risk, expected total cost and design life periods. Two basins, with 54-year and 104-year flood data respectively, are utilized to illustrate the application. It is found that the developed approach can effectively reveal changes of expected total cost and extreme floods in different design life periods. In addition, trade-offs are found between extreme flood risk and expected total cost, which reflect increases in cost to mitigate risk. Comparing with stationary approaches which generate only one expected total cost curve and therefore only one design flood estimation, the proposed new approach generate design flood estimation intervals and the 'Risk-Cost' approach selects a design flood value from the intervals based on the trade-offs between extreme flood risk and expected total cost. This study provides a new approach towards a better understanding of the influence of non-stationarity on expected total cost and design floods, and could be beneficial to cost-benefit based non-stationary design flood estimation across the world.

Performance of Oil Infrastructure during Hurricane Harvey

NASA Astrophysics Data System (ADS)

Bernier, C.; Kameshwar, S.; Padgett, J.

2017-12-01

Three major refining centers - Corpus Christi, Houston, and Beaumont/Port Arthur - were affected during Hurricane Harvey. Damage to oil infrastructure, especially aboveground storage tanks (ASTs), caused the release of more than a million gallons of hazardous chemicals in the environment. The objective of this presentation is to identify and gain a better understanding of the different damage mechanisms that occurred during Harvey in order to avoid similar failures during future hurricane events. First, a qualitative description of the damage suffered by ASTs during Hurricane Harvey is presented. Analysis of aerial imagery and incident reports indicate that almost all spills were caused by rainfall and the associated flooding. The largest spill was caused by two large ASTs that floated due to flooding in the Houston Ship Channel releasing 500,000 gallons of gasoline. The vulnerability of ASTs subjected to flooding was already well known and documented from previous storm events. In addition to flooding, Harvey also exposed the vulnerability of ASTs with external floating roof to extreme rainfall; more than 15 floating roofs sank or tilted due to rain water accumulation on them, releasing pollutants in the atmosphere. Secondly, recent fragility models developed by the authors are presented which allow structural vulnerability assessment of floating roofs during rainfall events and ASTs during flood events. The fragility models are then coupled with Harvey rainfall and flood empirical data to identify the conditions (i.e.: internal liquid height or density, drainage system design and efficiency, etc.) that could have led to the observed failures during Hurricane Harvey. Finally, the conditions causing tank failures are studied to propose mitigation measures to prevent future AST failures during severe storm, flood, or rainfall events.

Delineating risk zones and evaluation of shelter centres for flood disaster management along the Pahang River Basin, Malaysia

PubMed Central

Isahak, Anizan; Siwar, Chamhuri; Ismail, Shaharuddin M.; Hanafi, Zulkifli; Zainuddin, Mohd S.

2018-01-01

Shelter centres are important locations to safeguard people from helpless situations and are an integral part of disaster risk reduction (DRR), particularly for flood DRR. The establishment of shelter centres, and their design based on scientific assessment, is crucial. Yet, they are very much related to the geographic location, socio-economic conditions and the livelihoods of the affected communities. However, many parts of the developing world are still lagging behind in ensuring such scientific design. Considering the flood disaster in 2014 that affected the residents living along the Pahang River Basin, in this study we delineate the communities at risk and evaluate the existing shelter centres to determine how they reduce people’s vulnerability to the risks associated with rural and urban landscapes. We used spatial analysis tools to delineate risk zones and to evaluate existing evacuation systems. A flood disaster risk map was produced to determine which communities are living with risks. Subsequently, the distribution of shelter centres examined whether they are able to support people living at the flood risk zones. These centres were also evaluated using a set of international guidelines for effective disaster shelters. This reveals that the number of shelter centres is not adequate. The designation and designing of shelter centres are not being done scientifically. The maps produced here have a lot of potential to support disaster management decisions, in particular site selection and the prioritisation of centres. The study concludes with a set of guidelines and recommendations for structural and non-structural measures, such as alternative livelihoods and the potential of ecotourism, which may improve the resilience among flood-affected communities; and the decision-making process for the overall flood DRR initiatives.

Potentialities of ensemble strategies for flood forecasting over the Milano urban area

NASA Astrophysics Data System (ADS)

Ravazzani, Giovanni; Amengual, Arnau; Ceppi, Alessandro; Homar, Víctor; Romero, Romu; Lombardi, Gabriele; Mancini, Marco

2016-08-01

Analysis of ensemble forecasting strategies, which can provide a tangible backing for flood early warning procedures and mitigation measures over the Mediterranean region, is one of the fundamental motivations of the international HyMeX programme. Here, we examine two severe hydrometeorological episodes that affected the Milano urban area and for which the complex flood protection system of the city did not completely succeed. Indeed, flood damage have exponentially increased during the last 60 years, due to industrial and urban developments. Thus, the improvement of the Milano flood control system needs a synergism between structural and non-structural approaches. First, we examine how land-use changes due to urban development have altered the hydrological response to intense rainfalls. Second, we test a flood forecasting system which comprises the Flash-flood Event-based Spatially distributed rainfall-runoff Transformation, including Water Balance (FEST-WB) and the Weather Research and Forecasting (WRF) models. Accurate forecasts of deep moist convection and extreme precipitation are difficult to be predicted due to uncertainties arising from the numeric weather prediction (NWP) physical parameterizations and high sensitivity to misrepresentation of the atmospheric state; however, two hydrological ensemble prediction systems (HEPS) have been designed to explicitly cope with uncertainties in the initial and lateral boundary conditions (IC/LBCs) and physical parameterizations of the NWP model. No substantial differences in skill have been found between both ensemble strategies when considering an enhanced diversity of IC/LBCs for the perturbed initial conditions ensemble. Furthermore, no additional benefits have been found by considering more frequent LBCs in a mixed physics ensemble, as ensemble spread seems to be reduced. These findings could help to design the most appropriate ensemble strategies before these hydrometeorological extremes, given the computational cost of running such advanced HEPSs for operational purposes.

The Complex Relationship Between Heavy Storms and Floods: Implication on Stormwater Drainage design and Management

NASA Astrophysics Data System (ADS)

Demissie, Y.; Mortuza, M. R.; Moges, E.; Yan, E.; Li, H. Y.

2017-12-01

Due to the lack of historical and future streamflow data for flood frequency analysis at or near most drainage sites, it is a common practice to directly estimate the design flood (maximum discharge or volume of stream for a given return period) based on storm frequency analysis and the resulted Intensity-Duration-Frequency (IDF) curves. Such analysis assumes a direct relationship between storms and floods with, for example, the 10-year rainfall expected to produce the 10-year flood. However, in reality, a storm is just one factor among the many other hydrological and metrological factors that can affect the peak flow and hydrograph. Consequently, a heavy storm does not necessarily always lead to flooding or a flood events with the same frequency. This is evident by the observed difference in the seasonality of heavy storms and floods in most regions. In order to understand site specific causal-effect relationship between heavy storms and floods and improve the flood analysis for stormwater drainage design and management, we have examined the contributions of various factors that affect floods using statistical and information theory methods. Based on the identified dominant causal-effect relationships, hydrologic and probability analyses were conducted to develop the runoff IDF curves taking into consideration the snowmelt and rain-on-snow effect, the difference in the storm and flood seasonality, soil moisture conditions, and catchment potential for flash and riverine flooding. The approach was demonstrated using data from military installations located in different parts of the United States. The accuracy of the flood frequency analysis and the resulted runoff IDF curves were evaluated based on the runoff IDF curves developed from streamflow measurements.

The "Prediflood" database of historical floods in Catalonia (NE Iberian Peninsula) AD 1035-2013, and its potential applications in flood analysis

NASA Astrophysics Data System (ADS)

Barriendos, M.; Ruiz-Bellet, J. L.; Tuset, J.; Mazón, J.; Balasch, J. C.; Pino, D.; Ayala, J. L.

2014-07-01

"Prediflood" is a database of historical floods occurred in Catalonia (NE Iberian Peninsula), between 10th Century and 21th Century. More than 2700 flood cases are catalogued, and more than 1100 flood events. This database contains information acquired under modern historiographical criteria and it is, therefore, apt to be used in multidisciplinary flood analysis techniques, as meteorological or hydraullic reconstructions.

Hydrology and Flood Profiles of Duck Creek and Jordan Creek Downstream from Egan Drive, Juneau, Alaska

USGS Publications Warehouse

Curran, Janet H.

2007-01-01

Hydrologic and hydraulic updates for Duck Creek and the lower part of Jordan Creek in Juneau, Alaska, included computation of new estimates of peak streamflow magnitudes and new water-surface profiles for the 10-, 50-, 100-, and 500-year floods. Computations for the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence interval flood magnitudes for both streams used data from U.S. Geological Survey stream-gaging stations weighted with regional regression equations for southeast Alaska. The study area for the hydraulic model consisted of three channels: Duck Creek from Taku Boulevard near the stream's headwaters to Radcliffe Road near the end of the Juneau International Airport runway, an unnamed tributary to Duck Creek from Valley Boulevard to its confluence with Duck Creek, and Jordan Creek from a pedestrian bridge upstream from Egan Drive to Crest Street at Juneau International Airport. Field surveys throughout the study area provided channel geometry for 206 cross sections, and geometric and hydraulic characteristics for 29 culverts and 15 roadway, driveway, or pedestrian bridges. Hydraulic modeling consisted of application of the U.S. Army Corps of Engineers' Hydrologic Engineering Center River Analysis System (HEC-RAS) for steady-state flow at the selected recurrence intervals using an assumed high tide of 20 feet and roughness coefficients refined by calibration to measured water-surface elevations from a 2- to 5-year flood that occurred on November 21, 2005. Model simulation results identify inter-basin flow from Jordan Creek to the southeast at Egan Drive and from Duck Creek to Jordan Creek downstream from Egan Drive at selected recurrence intervals.

75 FR 7956 - Changes in Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 65 [Docket ID FEMA-2010-0003; Internal Agency Docket No. FEMA-B-1073] Changes in Flood Elevation Determinations AGENCY: Federal Emergency Management Agency, DHS. ACTION: Interim rule. SUMMARY: This interim rule lists...

77 FR 73398 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2010-0003; Internal Agency Docket No. FEMA-B-1085] Proposed Flood Elevation Determinations AGENCY..., identified by Docket No. FEMA-B- 1085, to Luis Rodriguez, Chief, Engineering Management Branch, Federal...

77 FR 73393 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2010-0003; Internal Agency Docket No. FEMA-B-1085] Proposed Flood Elevation Determinations AGENCY..., identified by Docket No. FEMA-B- 1085, to Luis Rodriguez, Chief, Engineering Management Branch, Federal...

Flood risk analysis for flood control and sediment transportation in sandy regions: A case study in the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Guo, Aijun; Chang, Jianxia; Wang, Yimin; Huang, Qiang; Zhou, Shuai

2018-05-01

Traditional flood risk analysis focuses on the probability of flood events exceeding the design flood of downstream hydraulic structures while neglecting the influence of sedimentation in river channels on regional flood control systems. This work advances traditional flood risk analysis by proposing a univariate and copula-based bivariate hydrological risk framework which incorporates both flood control and sediment transport. In developing the framework, the conditional probabilities of different flood events under various extreme precipitation scenarios are estimated by exploiting the copula-based model. Moreover, a Monte Carlo-based algorithm is designed to quantify the sampling uncertainty associated with univariate and bivariate hydrological risk analyses. Two catchments located on the Loess plateau are selected as study regions: the upper catchments of the Xianyang and Huaxian stations (denoted as UCX and UCH, respectively). The univariate and bivariate return periods, risk and reliability in the context of uncertainty for the purposes of flood control and sediment transport are assessed for the study regions. The results indicate that sedimentation triggers higher risks of damaging the safety of local flood control systems compared with the event that AMF exceeds the design flood of downstream hydraulic structures in the UCX and UCH. Moreover, there is considerable sampling uncertainty affecting the univariate and bivariate hydrologic risk evaluation, which greatly challenges measures of future flood mitigation. In addition, results also confirm that the developed framework can estimate conditional probabilities associated with different flood events under various extreme precipitation scenarios aiming for flood control and sediment transport. The proposed hydrological risk framework offers a promising technical reference for flood risk analysis in sandy regions worldwide.

Hazards of Extreme Weather: Flood Fatalities in Texas

NASA Astrophysics Data System (ADS)

Sharif, H. O.; Jackson, T.; Bin-Shafique, S.

2009-12-01

The Federal Emergency Management Agency (FEMA) considers flooding “America’s Number One Natural Hazard”. Despite flood management efforts in many communities, U.S. flood damages remain high, due, in large part, to increasing population and property development in flood-prone areas. Floods are the leading cause of fatalities related to natural disasters in Texas. Texas leads the nation in flash flood fatalities. There are three times more fatalities in Texas (840) than the following state Pennsylvania (265). This study examined flood fatalities that occurred in Texas between 1960 and 2008. Flood fatality statistics were extracted from three sources: flood fatality databases from the National Climatic Data Center, the Spatial Hazard Event and Loss Database for the United States, and the Texas Department of State Health Services. The data collected for flood fatalities include the date, time, gender, age, location, and weather conditions. Inconsistencies among the three databases were identified and discussed. Analysis reveals that most fatalities result from driving into flood water (about 65%). Spatial analysis indicates that more fatalities occurred in counties containing major urban centers. Hydrologic analysis of a flood event that resulted in five fatalities was performed. A hydrologic model was able to simulate the water level at a location where a vehicle was swept away by flood water resulting in the death of the driver.

Assessment of the Change Detection Procedure Dedicated to Flood Monitoring Using Envisat Wide Swath Mode Data

NASA Astrophysics Data System (ADS)

Li, Jiren; Yesou, Herve; Malosti, Rita; Andreoli, Remi; Huang, Shifeng; Xin, Jingfeng; Cattaneo, Fabrizia

2008-04-01

The Flood Dragon project enhances the Envisat contribution for natural disaster monitoring. Flood DFRAGON project had much more exploited the ENVISAT resource for crisis management than the International Charter Space and major Disasters since 2002. Indeed, during the 2005, 2006 and 2007 Chinese flood seasons, over the 27 attempted NRT exploitations of Envisat, 23 were successful. Obtained results over floods, affecting Yangtze and Songua, Huaihe watersheds as pollution events on Taihue lake and Nen River are illustrated. Lessons are discussed in terms of programming, downloading, processing, and images type and format. Recommendations for the background mission of the future Sentinel 1 constellation are given.

Collaborative multi-stakeholder approach to drafting flood risk management plans in Wallonia, Belgium

NASA Astrophysics Data System (ADS)

Maroy, Edith; Javaux, Mathieu; Vandermosten, Pierre; Englebert, Benjamin

2015-04-01

The Flood Directive 2007/60/CE establishes a common framework within the European Union for assessing and reducing risks posed by floods on human health, the environment, economic activity and cultural heritage. For that purpose, Member States had to establish flood areas and flood risk maps, and subsequently, flood risk management plans (due December 2015). According to the Directive, special attention is to be paid to international coordination for transboundary water courses, integrated management approaches at the catchment scale, cost-effectiveness of measures and public involvement. Management measures must focus on reducing the probability of flooding and the potential consequences of flooding. They must cover prevention, protection and preparedness and must take into account relevant aspects, such as water management, soil management, spatial planning, land use and nature conservation. Floods in Wallonia mostly originate from overflowing of both little sloped rivers and highly reactive rivers but also, from concentrated runoff in the intensely cultivated and erosion-prone region north of the Sambre-Meuse axis. Consequently, walloon flood area maps not only show flood areas based on hydraulic modelling and observations but also runoff concentration axis in agricultural areas. Now released to the public, this information can be used to assess the risk of damage for land planning and erosion control strategies. Incidentally, some 166 km2 were mapped as flood hazard area with a return period of 25 years, 28.8 of which are urbanized or destined to urbanisation and counting of number of approximatively 39.000 people living in those areas. Flood area and flood risk maps should be the starting point of elaborating flood risk management plans. In order to involve the diversity of water managers and stakeholders in the drafting of a management plan for hydrographic districts in Wallonia, responsible authorities decided to mandate scientists and engineers to organize an extensive participatory process. A series of meetings were organised, first, to raise awareness of local managers on the information provided by flood maps and on the objectives of the Directive towards integrated water management. Second, these successive meetings and the use of decision support tools such as a multicriteria analysis matrix allowed the team to collect local information on risks and opportunities, to foster emergence of integrated solutions, and to reach an agreement on priorities at the catchment scale and then at the regional level. This case study provides insights on practicability of using hydrological data on flood hazard in a collaborative, bottom-up approach to flood risk management. Lessons learnt from this project are a foundation for a realistic and effective management plan but limitations of the method and time constrains of this project leave a number of questions as to follow-up, exhaustiveness and cost-effectiveness of measures constituting the plan.

Demand analysis of flood insurance by using logistic regression model and genetic algorithm

NASA Astrophysics Data System (ADS)

Sidi, P.; Mamat, M. B.; Sukono; Supian, S.; Putra, A. S.

2018-03-01

Citarum River floods in the area of South Bandung Indonesia, often resulting damage to some buildings belonging to the people living in the vicinity. One effort to alleviate the risk of building damage is to have flood insurance. The main obstacle is not all people in the Citarum basin decide to buy flood insurance. In this paper, we intend to analyse the decision to buy flood insurance. It is assumed that there are eight variables that influence the decision of purchasing flood assurance, include: income level, education level, house distance with river, building election with road, flood frequency experience, flood prediction, perception on insurance company, and perception towards government effort in handling flood. The analysis was done by using logistic regression model, and to estimate model parameters, it is done with genetic algorithm. The results of the analysis shows that eight variables analysed significantly influence the demand of flood insurance. These results are expected to be considered for insurance companies, to influence the decision of the community to be willing to buy flood insurance.

The "Prediflood" database of historical floods in Catalonia (NE Iberian Peninsula) AD 1035-2013, and its potential applications in flood analysis

NASA Astrophysics Data System (ADS)

Barriendos, M.; Ruiz-Bellet, J. L.; Tuset, J.; Mazón, J.; Balasch, J. C.; Pino, D.; Ayala, J. L.

2014-12-01

"Prediflood" is a database of historical floods that occurred in Catalonia (NE Iberian Peninsula), between the 11th century and the 21st century. More than 2700 flood cases are catalogued, and more than 1100 flood events. This database contains information acquired under modern historiographical criteria and it is, therefore, suitable for use in multidisciplinary flood analysis techniques, such as meteorological or hydraulic reconstructions.

Boston Community Energy Study - Zonal Analysis for Urban Microgrids

DTIC Science & Technology

2016-03-01

ordinarily rural systems that have generation assets such as wind turbines (WTs) [14] or photovoltaic (PV) panels [15] that power loads such as lights and...movers powered by internal combustion engines, diesel engines, microturbines, geothermal systems, hydro systems, or wind turbines ; they also could include...can have on urban areas such as New York City. While flooding and wind damaged or destroyed some of the energy infrastructure, all installed

The Incidence of Posttraumatic Stress Disorder After Floods: A Meta-Analysis.

PubMed

Chen, Long; Liu, Aizhong

2015-06-01

This study analyzes the incidence of posttraumatic stress disorder (PTSD) among flood victims, between different flood intensities, and between different time points after a flood. A search of several electronic literature databases was conducted to collect data on the incidence of PTSD after a flood. Loney criteria for research quality were used to evaluate the quality of selected search results. The combined incidence of PTSD was estimated using the Freeman-Tukey double arcsine transformation method. Subgroup analyses were conducted on different trauma intensities and different time points after a flood. Sensitivity analysis was performed to evaluate the impact of research quality. Fourteen articles were included in this meta-analysis, including a total of 40 600 flood victims; 3862 victims were diagnosed with PTSD. The combined incidence of PTSD was 15.74%. The subgroup analyses showed that the incidence of PTSD in victims who experienced severe and moderate flood intensity was higher than that in victims who experienced mild flood intensity. The incidence of PTSD was lower at 6 or more months after a flood (11.45%) than within 6 months (16.01%) of a flood. In conclusion, the incidence of PTSD among floods of different trauma intensities was statistically significant.

First evaluation of the utility of GPM precipitation in global flood monitoring

NASA Astrophysics Data System (ADS)

Wu, H.; Yan, Y.; Gao, Z.

2017-12-01

The Global Flood Monitoring System (GFMS) has been developed and used to provide real-time flood detection and streamflow estimates over the last few years with significant success shown by validation against global flood event data sets and observed streamflow variations (Wu et al., 2014). It has become a tool for various national and international organizations to appraise flood conditions in various areas, including where rainfall and hydrology information is limited. The GFMS has been using the TRMM Multi-satellite Precipitation Analysis (TMPA) as its main rainfall input. Now, with the advent of the Global Precipitation Measurement (GPM) mission there is an opportunity to significantly improve global flood monitoring and forecasting. GPM's Integrated Multi-satellitE Retrievals for GPM (IMERG) multi-satellite product is designed to take advantage of various technical advances in the field and combine that with an efficient processing system producing "early" (4 hrs) and "late" (12 hrs) products for operational use. Specifically, this study is focused on (1) understanding the difference between the new IMERG products and other existing satellite precipitation products, e.g., TMPA, CMORPH, and ground observations; (2) addressing the challenge in the usage of the IMERG for flood monitoring through hydrologic models, given that only a short period of precipitation data record has been accumulated since the lunch of GPM in 2014; and (3) comparing the statistics of flood simulation based on the DRIVE model with IMERG, TMPA, CMORPH etc. as precipitation inputs respectively. Derivation of a global threshold map is a necessary step to define flood events out of modelling results, which requires a relatively longer historic information. A set of sensitivity tests are conducted by adjusting IMERG's light, moderate, heavy rain to existing precipitation products with long-term records separately, to optimize the strategy of PDF matching. Other aspects are also examined, including higher latitude events, where GPM precipitation algorithms should also provide improvements. This study provides a first evaluating the utility of the new IMERG products in flood monitoring through hydrologic modeling at a global scale.

Flood risk analysis for flood control and sediment transportation: a case study in the catchments of the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Wang, Y.; Chang, J.; Guo, A.

2017-12-01

Traditional flood risk analysis focuses on the probability of flood events exceeding the design flood of downstream hydraulic structures while neglecting the influence of sedimentation in river channels on flood control systems. Given this focus, a univariate and copula-based bivariate hydrological risk framework focusing on flood control and sediment transport is proposed in the current work. Additionally, the conditional probabilities of occurrence of different flood events under various extreme precipitation scenarios are estimated by exploiting the copula model. Moreover, a Monte Carlo-based algorithm is used to evaluate the uncertainties of univariate and bivariate hydrological risk. Two catchments located on the Loess plateau are selected as study regions: the upper catchments of the Xianyang and Huaxian stations (denoted as UCX and UCH, respectively). The results indicate that (1) 2-day and 3-day consecutive rainfall are highly correlated with the annual maximum flood discharge (AMF) in UCX and UCH, respectively; and (2) univariate and bivariate return periods, risk and reliability for the purposes of flood control and sediment transport are successfully estimated. Sedimentation triggers higher risks of damaging the safety of local flood control systems compared with the AMF, exceeding the design flood of downstream hydraulic structures in the UCX and UCH. Most importantly, there was considerable sampling uncertainty in the univariate and bivariate hydrologic risk analysis, which would greatly challenge measures of future flood mitigation. The proposed hydrological risk framework offers a promising technical reference for flood risk analysis in sandy regions worldwide.

76 FR 13571 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-14

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2008-0020; Internal Agency Docket No. FEMA-B-1072] Proposed Flood Elevation Determinations AGENCY... June 13, 2011. ADDRESSES: You may submit comments, identified by Docket No. FEMA-B- 1072, to Luis...

76 FR 50443 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-15

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2011-0002; Internal Agency Docket No. FEMA-B-1196] Proposed Flood Elevation Determinations Correction In proposed rule document 2011-16640 appearing on pages 39063 through 39067 in the issue of Tuesday...

76 FR 12308 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-07

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2011-0002; Internal Agency Docket No. FEMA-B-1174] Proposed Flood Elevation Determinations Correction In proposed rule document 2011-2281 beginning on page 5769 in the issue of Wednesday, February 2...

77 FR 73396 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2010-0003; Internal Agency Docket No. FEMA-B-1089] Proposed Flood Elevation Determinations AGENCY.... ADDRESSES: You may submit comments, identified by Docket No. FEMA-B- 1089, to Luis Rodriguez, Chief...

Managing Annual Flood Risk and Reducing Socioeconomic Flood Impacts in Rural Arctic through Science-Community Collaborations

NASA Astrophysics Data System (ADS)

Kontar, Y. Y.

2016-12-01

Multiple Arctic riverine communities face flood risk every spring. Within hours floodwater and ice debris destroy entire communities, displacing hundreds of people. In FY 2015-2016 an international project entitled Reducing Spring Flood Impacts for Wellbeing of Communities of the North was successfully conducted with the goal to identify best practices in managing the risk and reducing the socioeconomic impacts of floods associated with spring river ice breakup. In this presentation, we will elaborate on socioeconomic impacts of breakup floods, including long-term evacuation of population, loss of means of livelihoods, and ecosystem resource loss. We will also compare and contrast spring flood risk management and reduction strategies and their effectiveness in Alaska and Sakha Republic (Siberia), Russia. The findings are based on surveys completed by the representatives of adverse populations in two flood-prone communities in Alaska and Sakha Republic, as well as a series of roundtable discussions and interviews between social and geoscientists, emergency managers, and community leaders.

Flood Vulnerability Analysis of the part of Karad Region, Satara District, Maharashtra using Remote Sensing and Geographic Information System technique

NASA Astrophysics Data System (ADS)

Warghat, Sumedh R.; Das, Sandipan; Doad, Atul; Mali, Sagar; Moon, Vishal S.

2012-07-01

Karad City is situated on the bank of confluence of river Krishna & Koyana, which is severely flood prone area. The floodwaters enter the city through the roads and disrupt the infrastructure in the whole city. Furthermore, due to negligence of the authorities and unplanned growth of the city, the people living in the city have harnessed the natural flow of water by constructing unnecessary embankments in the river Koyna. Due to this reason now river koyna is flowing in the form of a narrow channel, which very easily over-flows during very minor flooding.Flood Vulnerabilty Analysis has been done for the karad region of satara district, maharashtra using remote sensing and geographic information system technique. The aim of this study is to identify flood vulnerability zone by using GIS and RS technique and an attempt has been to demonstrat the application of remote sensing and GIS in order to map flood vulnerabilty area by utilizing ArcMap, and Erdas software. Flood vulnerabilty analysis of part the Karad Regian of Satara District, Maharashtra has been carried out with the objectives - Identify the Flood Prone area in the Koyana and Krishna river basin, Calculate surface runoff and Delineate flood sensitive areas. Delineate classified hazard Map, Evaluate the Flood affected area, Prepare the Flood Vulnerability Map by utilizing Remote Sensing and GIS technique. (C.J. Kumanan;S.M. Ramasamy)The study is based on GIS and spatial technique is used for analysis and understanding of flood problem in Karad Tahsil. The flood affected areas of the different magnitude has been identified and mapped using Arc GIS software. The analysis is useful for local planning authority for identification of risk areas and taking proper decision in right moment. In the analysis causative factors for flooding in watershed are taken into account as annual rainfall, size of watershed, basin slope, drainage density of natural channels and land use. (Dinand Alkema; Farah Aziz.)This study of flood vulnerable area determination in a part of Karad Tahsil is employed to illustrate the different approaches.

Flood-hazard mapping in Honduras in response to Hurricane Mitch

USGS Publications Warehouse

Mastin, M.C.

2002-01-01

The devastation in Honduras due to flooding from Hurricane Mitch in 1998 prompted the U.S. Agency for International Development, through the U.S. Geological Survey, to develop a country-wide systematic approach of flood-hazard mapping and a demonstration of the method at selected sites as part of a reconstruction effort. The design discharge chosen for flood-hazard mapping was the flood with an average return interval of 50 years, and this selection was based on discussions with the U.S. Agency for International Development and the Honduran Public Works and Transportation Ministry. A regression equation for estimating the 50-year flood discharge using drainage area and annual precipitation as the explanatory variables was developed, based on data from 34 long-term gaging sites. This equation, which has a standard error of prediction of 71.3 percent, was used in a geographic information system to estimate the 50-year flood discharge at any location for any river in the country. The flood-hazard mapping method was demonstrated at 15 selected municipalities. High-resolution digital-elevation models of the floodplain were obtained using an airborne laser-terrain mapping system. Field verification of the digital elevation models showed that the digital-elevation models had mean absolute errors ranging from -0.57 to 0.14 meter in the vertical dimension. From these models, water-surface elevation cross sections were obtained and used in a numerical, one-dimensional, steady-flow stepbackwater model to estimate water-surface profiles corresponding to the 50-year flood discharge. From these water-surface profiles, maps of area and depth of inundation were created at the 13 of the 15 selected municipalities. At La Lima only, the area and depth of inundation of the channel capacity in the city was mapped. At Santa Rose de Aguan, no numerical model was created. The 50-year flood and the maps of area and depth of inundation are based on the estimated 50-year storm tide.

Analysis of regional natural flow for evaluation of flood risk according to RCP climate change scenarios

NASA Astrophysics Data System (ADS)

Lee, J. Y.; Chae, B. S.; Wi, S.; KIm, T. W.

2017-12-01

Various climate change scenarios expect the rainfall in South Korea to increase by 3-10% in the future. The future increased rainfall has significant effect on the frequency of flood in future as well. This study analyzed the probability of future flood to investigate the stability of existing and new installed hydraulic structures and the possibility of increasing flood damage in mid-sized watersheds in South Korea. To achieve this goal, we first clarified the relationship between flood quantiles acquired from the flood-frequency analysis (FFA) and design rainfall-runoff analysis (DRRA) in gauged watersheds. Then, after synthetically generating the regional natural flow data according to RCP climate change scenarios, we developed mathematical formulas to estimate future flood quantiles based on the regression between DRRA and FFA incorporated with regional natural flows in unguaged watersheds. Finally, we developed a flood risk map to investigate the change of flood risk in terms of the return period for the past, present, and future. The results identified that the future flood quantiles and risks would increase in accordance with the RCP climate change scenarios. Because the regional flood risk was identified to increase in future comparing with the present status, comprehensive flood control will be needed to cope with extreme floods in future.

Flood Risk Analysis in Denpasar City, Bali, Indonesia

NASA Astrophysics Data System (ADS)

Kusmiyarti, T. B.; Wiguna, P. P. K.; Ratna Dewi, N. K. R.

2018-02-01

Denpasar city is a Capital City of Bali Province and one of the leading tourist destinations in Indonesia. Denpasar area is relatively flat with high rain fall intensity with the domince of settlement. This makes Denpasar City becomes prone area of flood. The aim of this research is to find out the spatial distribution flood hazard and the risk of population which are affected to the flood hazard. Weighting, scoring and overlaying method were used in this research. Six indicators were used to analyze the flood hazard: landuse, rainfall, type of soil, slope, altitute and drainage density. The vulnerability is analyzed per Desa or Kelurahan (Rustic/Neighborhood) with the indicator of age, education and population density. Risk was calculated by multiplied hazard with vulnerability and divided with coping capacity. In this research, coping capacity is determined by the amount of internal budget for each Desa or Kelurahan for development purpose. Flood risk in Denpasar city is divided into five classes, very low risk, low risk, medium risk, high risk and very high risk. Total population with very high risk reached 202478 people or 13.16% of total population. The total area is 780.7 ha or 16.02% from total settlement in Denpasar city. Total population with high risk reached 202478 people or 13.16% of total population. The total area is 780.7 ha or 16.02% from total settlement in Denpasar city. The number of population with medium risk reached 202478 people or 33.51% of total population which occupied 22.95% of total settlements or 1118.18 ha. The total number of population with low risk reached 79435 people or 13.14% of total population with area of low flood risk is 716.89 ha or 14.71% of total settlements in Denpasar City. Very low flood risk with total population at risk reached 19184 people or 31.74% of total population and occupied 2003.54 areas or 41.12% of total areas of settlements.

Assessing floods and droughts in the Mékrou River basin (West Africa): a combined household survey and climatic trends analysis approach

NASA Astrophysics Data System (ADS)

Markantonis, Vasileios; Farinosi, Fabio; Dondeynaz, Celine; Ameztoy, Iban; Pastori, Marco; Marletta, Luca; Ali, Abdou; Carmona Moreno, Cesar

2018-05-01

The assessment of natural hazards such as floods and droughts is a complex issue that demands integrated approaches and high-quality data. Especially in African developing countries, where information is limited, the assessment of floods and droughts, though an overarching issue that influences economic and social development, is even more challenging. This paper presents an integrated approach to assessing crucial aspects of floods and droughts in the transboundary Mékrou River basin (a portion of the Niger River basin in West Africa), combining climatic trends analysis and the findings of a household survey. The multivariable trend analysis estimates, at the biophysical level, the climate variability and the occurrence of floods and droughts. These results are coupled with an analysis of household survey data that reveals the behaviour and opinions of local residents regarding the observed climate variability and occurrence of flood and drought events, household mitigation measures, and the impacts of floods and droughts. Based on survey data analysis, the paper provides a per-household cost estimation of floods and droughts that occurred over a 2-year period (2014-2015). Furthermore, two econometric models are set up to identify the factors that influence the costs of floods and droughts to impacted households.

Development of Integrated Flood Analysis System for Improving Flood Mitigation Capabilities in Korea

NASA Astrophysics Data System (ADS)

Moon, Young-Il; Kim, Jong-suk

2016-04-01

Recently, the needs of people are growing for a more safety life and secure homeland from unexpected natural disasters. Flood damages have been recorded every year and those damages are greater than the annual average of 2 trillion won since 2000 in Korea. It has been increased in casualties and property damages due to flooding caused by hydrometeorlogical extremes according to climate change. Although the importance of flooding situation is emerging rapidly, studies related to development of integrated management system for reducing floods are insufficient in Korea. In addition, it is difficult to effectively reduce floods without developing integrated operation system taking into account of sewage pipe network configuration with the river level. Since the floods result in increasing damages to infrastructure, as well as life and property, structural and non-structural measures should be urgently established in order to effectively reduce the flood. Therefore, in this study, we developed an integrated flood analysis system that systematized technology to quantify flood risk and flood forecasting for supporting synthetic decision-making through real-time monitoring and prediction on flash rain or short-term rainfall by using radar and satellite information in Korea. Keywords: Flooding, Integrated flood analysis system, Rainfall forecasting, Korea Acknowledgments This work was carried out with the support of "Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ011686022015)" Rural Development Administration, Republic of Korea

14 CFR 1216.200 - Scope.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Management; and, (h) Establish internal management controls to monitor NASA actions to assure compliance with... Wetlands Management § 1216.200 Scope. This subpart 1216.2 prescribes procedures to: (a) Avoid long- and... practicable alternative; (c) Reduce the risk of flood loss; (d) Minimize the impact of floods on human health...

Development of high-resolution multi-scale modelling system for simulation of coastal-fluvial urban flooding

NASA Astrophysics Data System (ADS)

Comer, Joanne; Indiana Olbert, Agnieszka; Nash, Stephen; Hartnett, Michael

2017-02-01

Urban developments in coastal zones are often exposed to natural hazards such as flooding. In this research, a state-of-the-art, multi-scale nested flood (MSN_Flood) model is applied to simulate complex coastal-fluvial urban flooding due to combined effects of tides, surges and river discharges. Cork city on Ireland's southwest coast is a study case. The flood modelling system comprises a cascade of four dynamically linked models that resolve the hydrodynamics of Cork Harbour and/or its sub-region at four scales: 90, 30, 6 and 2 m. Results demonstrate that the internalization of the nested boundary through the use of ghost cells combined with a tailored adaptive interpolation technique creates a highly dynamic moving boundary that permits flooding and drying of the nested boundary. This novel feature of MSN_Flood provides a high degree of choice regarding the location of the boundaries to the nested domain and therefore flexibility in model application. The nested MSN_Flood model through dynamic downscaling facilitates significant improvements in accuracy of model output without incurring the computational expense of high spatial resolution over the entire model domain. The urban flood model provides full characteristics of water levels and flow regimes necessary for flood hazard identification and flood risk assessment.

Demonstrating Change with Astronaut Photography Using Object Based Image Analysis

NASA Technical Reports Server (NTRS)

Hollier, Andi; Jagge, Amy

2017-01-01

Every day, hundreds of images of Earth flood the Crew Earth Observations database as astronauts use hand held digital cameras to capture spectacular frames from the International Space Station. The variety of resolutions and perspectives provide a template for assessing land cover change over decades. We will focus on urban growth in the second fastest growing city in the nation, Houston, TX, using Object-Based Image Analysis. This research will contribute to the land change science community, integrated resource planning, and monitoring of the rapid rate of urban sprawl.

The index-flood and the GRADEX methods combination for flood frequency analysis.

NASA Astrophysics Data System (ADS)

Fuentes, Diana; Di Baldassarre, Giuliano; Quesada, Beatriz; Xu, Chong-Yu; Halldin, Sven; Beven, Keith

2017-04-01

Flood frequency analysis is used in many applications, including flood risk management, design of hydraulic structures, and urban planning. However, such analysis requires of long series of observed discharge data which are often not available in many basins around the world. In this study, we tested the usefulness of combining regional discharge and local precipitation data to estimate the event flood volume frequency curve for 63 catchments in Mexico, Central America and the Caribbean. This was achieved by combining two existing flood frequency analysis methods, the regionalization index-flood approach with the GRADEX method. For up to 10-years return period, similar shape of the scaled flood frequency curve for catchments with similar flood behaviour was assumed from the index-flood approach. For return periods larger than 10-years the probability distribution of rainfall and discharge volumes were assumed to be asymptotically and exponential-type functions with the same scale parameter from the GRADEX method. Results showed that if the mean annual flood (MAF), used as index-flood, is known, the index-flood approach performed well for up to 10 years return periods, resulting in 25% mean relative error in prediction. For larger return periods the prediction capability decreased but could be improved by the use of the GRADEX method. As the MAF is unknown at ungauged and short-period measured basins, we tested predicting the MAF using catchments climate-physical characteristics, and discharge statistics, the latter when observations were available for only 8 years. Only the use of discharge statistics resulted in acceptable predictions.

Analyses of flooding tolerance of soybean varieties at emergence and varietal differences in their proteomes.

PubMed

Nanjo, Yohei; Jang, Hee-Young; Kim, Hong-Sig; Hiraga, Susumu; Woo, Sun-Hee; Komatsu, Setsuko

2014-10-01

Flooding of fields due to heavy and/or continuous rainfall influences soybean production. To identify soybean varieties with flooding tolerance at the seedling emergence stage, 128 soybean varieties were evaluated using a flooding tolerance index, which is based on plant survival rates, the lack of apparent damage and lateral root development, and post-flooding radicle elongation rate. The soybean varieties were ranked according to their flooding tolerance index, and it was found that the tolerance levels of soybean varieties exhibit a continuum of differences between varieties. Subsequently, tolerant, moderately tolerant and sensitive varieties were selected and subjected to comparative proteomic analysis to clarify the tolerance mechanism. Proteomic analysis of the radicles, combined with correlation analysis, showed that the ratios of RNA binding/processing related proteins and flooding stress indicator proteins were significantly correlated with flooding tolerance index. The RNA binding/processing related proteins were positively correlated in untreated soybeans, whereas flooding stress indicator proteins were negatively correlated in flooded soybeans. These results suggest that flooding tolerance is regulated by mechanisms through multiple factors and is associated with abundance levels of the identified proteins. Copyright © 2014 Elsevier Ltd. All rights reserved.

Collaborative Initiative toward Developing River Forecasting in South America

NASA Astrophysics Data System (ADS)

Cabrera, R.

2015-12-01

In the United States, river floods have been discussed as early as 1884. Following a disastrous flooding in 1903, Congress passed legislation and river and flood services became a separate division within the U.S. Weather Bureau. The first River Forecast Center started in 1946 and today the whole country is served by thirteen River Forecast Centers. News from Latin American and Caribbean Countries often report of devastating flooding. However, river forecast services are not fully developed yet. This presentation suggests the utilization of a multinational collaborative approach toward the development of river forecasts in order to mitigate flooding in South America. The benefit of an international strategy resides in the strength created by a team of professionals with different capabilities and expertise.

Development of method for evaluating estimated inundation area by using river flood analysis based on multiple flood scenarios

NASA Astrophysics Data System (ADS)

Ono, T.; Takahashi, T.

2017-12-01

Non-structural mitigation measures such as flood hazard map based on estimated inundation area have been more important because heavy rains exceeding the design rainfall frequently occur in recent years. However, conventional method may lead to an underestimation of the area because assumed locations of dike breach in river flood analysis are limited to the cases exceeding the high-water level. The objective of this study is to consider the uncertainty of estimated inundation area with difference of the location of dike breach in river flood analysis. This study proposed multiple flood scenarios which can set automatically multiple locations of dike breach in river flood analysis. The major premise of adopting this method is not to be able to predict the location of dike breach correctly. The proposed method utilized interval of dike breach which is distance of dike breaches placed next to each other. That is, multiple locations of dike breach were set every interval of dike breach. The 2D shallow water equations was adopted as the governing equation of river flood analysis, and the leap-frog scheme with staggered grid was used. The river flood analysis was verified by applying for the 2015 Kinugawa river flooding, and the proposed multiple flood scenarios was applied for the Akutagawa river in Takatsuki city. As the result of computation in the Akutagawa river, a comparison with each computed maximum inundation depth of dike breaches placed next to each other proved that the proposed method enabled to prevent underestimation of estimated inundation area. Further, the analyses on spatial distribution of inundation class and maximum inundation depth in each of the measurement points also proved that the optimum interval of dike breach which can evaluate the maximum inundation area using the minimum assumed locations of dike breach. In brief, this study found the optimum interval of dike breach in the Akutagawa river, which enabled estimated maximum inundation area to predict efficiently and accurately. The river flood analysis by using this proposed method will contribute to mitigate flood disaster by improving the accuracy of estimated inundation area.

Long-term effects of flooding on mortality in England and Wales, 1994-2005: controlled interrupted time-series analysis

PubMed Central

2011-01-01

Background Limited evidence suggests that being flooded may increase mortality and morbidity among affected householders not just at the time of the flood but for months afterwards. The objective of this study is to explore the methods for quantifying such long-term health effects of flooding by analysis of routine mortality registrations in England and Wales. Methods Mortality data, geo-referenced by postcode of residence, were linked to a national database of flood events for 1994 to 2005. The ratio of mortality in the post-flood year to that in the pre-flood year within flooded postcodes was compared with that in non-flooded boundary areas (within 5 km of a flood). Further analyses compared the observed number of flood-area deaths in the year after flooding with the number expected from analysis of mortality trends stratified by region, age-group, sex, deprivation group and urban-rural status. Results Among the 319 recorded floods, there were 771 deaths in the year before flooding and 693 deaths in the year after (post-/pre-flood ratio of 0.90, 95% CI 0.82, 1.00). This ratio did not vary substantially by age, sex, population density or deprivation. A similar post-flood 'deficit' of deaths was suggested by the analyses based on observed/expected deaths. Conclusions The observed post-flood 'deficit' of deaths is counter-intuitive and difficult to interpret because of the possible influence of population displacement caused by flooding. The bias that might arise from such displacement remains unquantified but has important implications for future studies that use place of residence as a marker of exposure. PMID:21288358

Post flood damage data collection and assessment in Albania based on DesInventar methodology

NASA Astrophysics Data System (ADS)

Toto, Emanuela; Massabo, Marco; Deda, Miranda; Rossello, Laura

2015-04-01

In 2013 in Albania was implemented a collection of disaster losses based on Desinventar. The DesInventar system consists in a methodology and software tool that lead to the systematic collection, documentation and analysis of loss data on disasters. The main sources of information about disasters used for the Albanian database were the Albanian Ministry of Internal Affairs, the National Library and the State archive. Specifically for floods the database created contains nearly 900 datasets, for a period of 148 years (from 1865 to 2013). The data are georeferenced on the administrative units of Albania: Region, Provinces and Municipalities. The datasets describe the events by reporting the date of occurrence, the duration, the localization in administrative units and the cause. Additional information regards the effects and damage that the event caused on people (deaths, injured, missing, affected, relocated, evacuated, victims) and on houses (houses damaged or destroyed). Other quantitative indicators are the losses in local currency or US dollars, the damage on roads, the crops affected , the lost cattle and the involvement of social elements over the territory such as education and health centers. Qualitative indicators simply register the sectors (e.g. transportations, communications, relief, agriculture, water supply, sewerage, power and energy, industries, education, health sector, other sectors) that were affected. Through the queries and analysis of the data collected it was possible to identify the most affected areas, the economic loss, the damage in agriculture, the houses and people affected and many other variables. The most vulnerable Regions for the past floods in Albania were studied and individuated, as well as the rivers that cause more damage in the country. Other analysis help to estimate the damage and losses during the main flood events of the recent years, occurred in 2010 and 2011, and to recognize the most affected sectors. The database was used to find the most frequent drivers that cause floods and to identify the areas with a higher priority for intervention and the areas with a higher economic loss. In future the loss and damage database could address interventions for risk mitigation and decision making processes. Using the database is also possible to build Empirical Loss Exceedance Curves, that permit to find the average number of times for year that a certain level of loss happened. The users of the database information can be researchers, students, citizens and policy makers. The operators of the National Operative Center for Civil Emergencies (Albanian Ministry of Internal Affairs) use the database daily to insert new data. Nowadays in Albania there isn't an entity in charge for the registration of damage and consequences of floods in a systematic and organized way. In this sense, the database DesInventar provides a basis for the future and helps to identify priorities to create a national database.

The Significance of the Record Length in Flood Frequency Analysis

NASA Astrophysics Data System (ADS)

Senarath, S. U.

2013-12-01

Of all of the potential natural hazards, flood is the most costly in many regions of the world. For example, floods cause over a third of Europe's average annual catastrophe losses and affect about two thirds of the people impacted by natural catastrophes. Increased attention is being paid to determining flow estimates associated with pre-specified return periods so that flood-prone areas can be adequately protected against floods of particular magnitudes or return periods. Flood frequency analysis, which is conducted by using an appropriate probability density function that fits the observed annual maximum flow data, is frequently used for obtaining these flow estimates. Consequently, flood frequency analysis plays an integral role in determining the flood risk in flood prone watersheds. A long annual maximum flow record is vital for obtaining accurate estimates of discharges associated with high return period flows. However, in many areas of the world, flood frequency analysis is conducted with limited flow data or short annual maximum flow records. These inevitably lead to flow estimates that are subject to error. This is especially the case with high return period flow estimates. In this study, several statistical techniques are used to identify errors caused by short annual maximum flow records. The flow estimates used in the error analysis are obtained by fitting a log-Pearson III distribution to the flood time-series. These errors can then be used to better evaluate the return period flows in data limited streams. The study findings, therefore, have important implications for hydrologists, water resources engineers and floodplain managers.

Flood protection diversification to reduce probabilities of extreme losses.

PubMed

Zhou, Qian; Lambert, James H; Karvetski, Christopher W; Keisler, Jeffrey M; Linkov, Igor

2012-11-01

Recent catastrophic losses because of floods require developing resilient approaches to flood risk protection. This article assesses how diversification of a system of coastal protections might decrease the probabilities of extreme flood losses. The study compares the performance of portfolios each consisting of four types of flood protection assets in a large region of dike rings. A parametric analysis suggests conditions in which diversifications of the types of included flood protection assets decrease extreme flood losses. Increased return periods of extreme losses are associated with portfolios where the asset types have low correlations of economic risk. The effort highlights the importance of understanding correlations across asset types in planning for large-scale flood protection. It allows explicit integration of climate change scenarios in developing flood mitigation strategy. © 2012 Society for Risk Analysis.

76 FR 3595 - Proposed Flood Elevation Determinations for Cumberland County, ME (All Jurisdictions)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2008-0020; Internal Agency Docket No. FEMA-B-1060] Proposed Flood Elevation Determinations for Cumberland County, ME (All Jurisdictions) AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice of...

76 FR 26980 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

...-2010-0003; Internal Agency Docket No. FEMA-B-1155] Proposed Flood Elevation Determinations AGENCY... Lake Michigan and White Ditch in La Porte County, Indiana. The City of Michiana Shores should have been listed as the Town of Michiana Shores. DATES: Comments pertaining to the Lake Michigan and White Ditch...

78 FR 45944 - Proposed Flood Hazard Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-30

...; Internal Agency Docket No. FEMA-B-1247] Proposed Flood Hazard Determinations AGENCY: Federal Emergency... at www.msc.fema.gov for comparison. You may submit comments, identified by Docket No. FEMA-B-1247, to...-4064 or (email) [email protected] ; or visit the FEMA Map Information eXchange (FMIX) online...

77 FR 66791 - Proposed Flood Elevation Determinations for Wicomico County, MD, and Incorporated Areas

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 67 [Docket ID FEMA-2010-0003; Internal Agency Docket No. FEMA-B-1085] Proposed Flood Elevation Determinations for Wicomico..., identified by Docket No. FEMA-B- 1085, to Luis Rodriguez, Chief, Engineering Management Branch, Federal...

Denial of flood aid to members of the Ahmadiyya Muslim community in Pakistan.

PubMed

Malik, Atif M

2011-07-14

During the catastrophic floods of 2010 in Pakistan, approximately 500 internally displaced families belonging to the Ahmadiyya sect of Islam were denied humanitarian relief. The failure of international agencies and Pakistan's government to protect basic human rights in the context of disaster relief raises profound questions. If all humanitarian work associated with natural disasters must be governed by canons of human rights, how should international agencies deal with legally empowered official discrimination? A review of the history of the Ahmadiyya community in Pakistan reveals decades of state-sanctioned persecution, particularly through its anti-blasphemy laws, and poses a serious challenge to the international community. When effective intervention is predicated on cooperation with state institutions, how can international relief agencies avoid becoming implicated in official discrimination? The denial of flood aid to Pakistan's Ahmadiyya community highlights the need for concerted action in disaster settings to prevent discrimination against vulnerable groups. Discriminatory legislation is not only a violation of basic norms enshrined in international compacts, it is a key problem for disaster relief. Copyright © 2011 Malik. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

Flooding greatly affects the diversity of arbuscular mycorrhizal fungi communities in the roots of wetland plants.

PubMed

Wang, Yutao; Huang, Yelin; Qiu, Qiu; Xin, Guorong; Yang, Zhongyi; Shi, Suhua

2011-01-01

The communities of arbuscular mycorrhizal fungi (AMF) colonizing the roots of three mangrove species were characterized along a tidal gradient in a mangrove swamp. A fragment, designated SSU-ITS-LSU, including part of the small subunit (SSU), the entire internal transcribed spacer (ITS) and part of the large subunit (LSU) of rDNA from samples of AMF-colonized roots was amplified, cloned and sequenced using AMF-specific primers. Similar levels of AMF diversity to those observed in terrestrial ecosystems were detected in the roots, indicating that the communities of AMF in wetland ecosystems are not necessarily low in diversity. In total, 761 Glomeromycota sequences were obtained, which grouped, according to phylogenetic analysis using the SSU-ITS-LSU fragment, into 23 phylotypes, 22 of which belonged to Glomeraceae and one to Acaulosporaceae. The results indicate that flooding plays an important role in AMF diversity, and its effects appear to depend on the degree (duration) of flooding. Both host species and tide level affected community structure of AMF, indicating the presence of habitat and host species preferences.

Flooding Greatly Affects the Diversity of Arbuscular Mycorrhizal Fungi Communities in the Roots of Wetland Plants

PubMed Central

Wang, Yutao; Huang, Yelin; Qiu, Qiu; Xin, Guorong; Yang, Zhongyi; Shi, Suhua

2011-01-01

The communities of arbuscular mycorrhizal fungi (AMF) colonizing the roots of three mangrove species were characterized along a tidal gradient in a mangrove swamp. A fragment, designated SSU-ITS-LSU, including part of the small subunit (SSU), the entire internal transcribed spacer (ITS) and part of the large subunit (LSU) of rDNA from samples of AMF-colonized roots was amplified, cloned and sequenced using AMF-specific primers. Similar levels of AMF diversity to those observed in terrestrial ecosystems were detected in the roots, indicating that the communities of AMF in wetland ecosystems are not necessarily low in diversity. In total, 761 Glomeromycota sequences were obtained, which grouped, according to phylogenetic analysis using the SSU-ITS-LSU fragment, into 23 phylotypes, 22 of which belonged to Glomeraceae and one to Acaulosporaceae. The results indicate that flooding plays an important role in AMF diversity, and its effects appear to depend on the degree (duration) of flooding. Both host species and tide level affected community structure of AMF, indicating the presence of habitat and host species preferences. PMID:21931734

Sequential planning of flood protection infrastructure under limited historic flood record and climate change uncertainty

NASA Astrophysics Data System (ADS)

Dittes, Beatrice; Špačková, Olga; Straub, Daniel

2017-04-01

Flood protection is often designed to safeguard people and property following regulations and standards, which specify a target design flood protection level, such as the 100-year flood level prescribed in Germany (DWA, 2011). In practice, the magnitude of such an event is only known within a range of uncertainty, which is caused by limited historic records and uncertain climate change impacts, among other factors (Hall & Solomatine, 2008). As more observations and improved climate projections become available in the future, the design flood estimate changes and the capacity of the flood protection may be deemed insufficient at a future point in time. This problem can be mitigated by the implementation of flexible flood protection systems (that can easily be adjusted in the future) and/or by adding an additional reserve to the flood protection, i.e. by applying a safety factor to the design. But how high should such a safety factor be? And how much should the decision maker be willing to pay to make the system flexible, i.e. what is the Value of Flexibility (Špačková & Straub, 2017)? We propose a decision model that identifies cost-optimal decisions on flood protection capacity in the face of uncertainty (Dittes et al. 2017). It considers sequential adjustments of the protection system during its lifetime, taking into account its flexibility. The proposed framework is based on pre-posterior Bayesian decision analysis, using Decision Trees and Markov Decision Processes, and is fully quantitative. It can include a wide range of uncertainty components such as uncertainty associated with limited historic record or uncertain climate or socio-economic change. It is shown that since flexible systems are less costly to adjust when flood estimates are changing, they justify initially lower safety factors. Investigation on the Value of Flexibility (VoF) demonstrates that VoF depends on the type and degree of uncertainty, on the learning effect (i.e. kind and quality of information that we will gather in the future) and on the formulation of the optimization problem (risk-based vs. rule-based approach). The application of the framework is demonstrated on catchments in Germany. References: DWA (Deutsche Vereinigung für Wasserwirtschaft Abwasser und Abfall eV.) 2011. Merkblatt DWA-M 507-1: Deiche an Fließgewässern. (A. Bieberstein, Ed.). Hennef: DWA Deutsche Vereinigung für Wasserwirtschaft, Abwasser und Abfall e. V. Hall, J., & Solomatine, D. 2008. A framework for uncertainty analysis in flood risk management decisions. International Journal of River Basin Management, 6(2), 85-98. http://doi.org/10.1080/15715124.2008.9635339 Špačková, O. & Straub, D. 2017. Long-term adaption decisions via fully and partially observable Markov decision processes. Sustainable and Resilient Infrastructure. In print.

Sea-Level Rise and Flood Potential along the California Coast

NASA Astrophysics Data System (ADS)

Delepine, Q.; Leung, C.

2013-12-01

Sea-level rise is becoming an ever-increasing problem in California. Sea-level is expected to rise significantly in the next 100 years, which will raise flood elevations in coastal communities. This will be an issue for private homeowners, businesses, and the state. One study suggests that Venice Beach could lose a total of at least $440 million in tourism spending and tax dollars from flooding and beach erosion if sea level rises 1.4 m by 2100. In addition, several airports, such as San Francisco International Airport, are located in coastal regions that have flooded in the past and will likely be flooded again in the next 30 years, but sea-level rise is expected to worsen the effects of flooding in the coming decades It is vital for coastal communities to understand the risks associated with sea-level rise so that they can plan to adapt to it. By obtaining accurate LiDAR elevation data from the NOAA Digital Coast Website (http://csc.noaa.gov/dataviewer/?keyword=lidar#), we can create flood maps to simulate sea level rise and flooding. The data are uploaded to ArcGIS and contour lines are added for different elevations that represent future coastlines during 100-year flooding. The following variables are used to create the maps: 1. High-resolution land surface elevation data - obtained from NOAA 2. Local mean high water level - from USGS 3. Local 100-year flood water level - from the Pacific Institute 4. Sea-level rise projections for different future dates (2030, 2050, and 2100) - from the National Research Council The values from the last three categories are added to represent sea-level rise plus 100-year flooding. These values are used to make the contour lines that represent the projected flood elevations, which are then exported as KML files, which can be opened in Google Earth. Once these KML files are made available to the public, coastal communities will gain an improved understanding of how flooding and sea-level rise might affect them in the future. This would allow them to plan ahead to reduce the level of risk to homes, industry, and infrastructure San Francisco International Airport will be most likely be flooded in the next 30 years. Blue lines indicate current Mean High Water Levels. Yellow lines indicate the Mean High Water level combined with flood levels for 2030. Green, 2050, and Red lines, 2100

Statistical analysis of the uncertainty related to flood hazard appraisal

NASA Astrophysics Data System (ADS)

Notaro, Vincenza; Freni, Gabriele

2015-12-01

The estimation of flood hazard frequency statistics for an urban catchment is of great interest in practice. It provides the evaluation of potential flood risk and related damage and supports decision making for flood risk management. Flood risk is usually defined as function of the probability, that a system deficiency can cause flooding (hazard), and the expected damage, due to the flooding magnitude (damage), taking into account both the exposure and the vulnerability of the goods at risk. The expected flood damage can be evaluated by an a priori estimation of potential damage caused by flooding or by interpolating real damage data. With regard to flood hazard appraisal several procedures propose to identify some hazard indicator (HI) such as flood depth or the combination of flood depth and velocity and to assess the flood hazard corresponding to the analyzed area comparing the HI variables with user-defined threshold values or curves (penalty curves or matrixes). However, flooding data are usually unavailable or piecemeal allowing for carrying out a reliable flood hazard analysis, therefore hazard analysis is often performed by means of mathematical simulations aimed at evaluating water levels and flow velocities over catchment surface. As results a great part of the uncertainties intrinsic to flood risk appraisal can be related to the hazard evaluation due to the uncertainty inherent to modeling results and to the subjectivity of the user defined hazard thresholds applied to link flood depth to a hazard level. In the present work, a statistical methodology was proposed for evaluating and reducing the uncertainties connected with hazard level estimation. The methodology has been applied to a real urban watershed as case study.

Controversy, Conflict and Compromise: A History of the Lower Snake River Development

DTIC Science & Technology

1994-01-01

floods. Most of the Bonneville Flood’s impact can be seen along the upper Snake because the Missoula floods covered all evidence of Bonneville along the...engines, but found that an unsatisfactory long-term solution. He then bought the Starbuck Electric Power Company and ran a line the dozen or so miles...Steams papers, Cage4148, WSU MASC. [13) For excellent descriptions of the international grain trade of the 19th century and its impact on Inland

Household economic and food security after the 2010 Pakistan floods.

PubMed

Doocy, Shannon; Leidman, Eva; Aung, Tricia; Kirsch, Thomas

2013-03-01

The 2010 floods inundated one-fifth of Pakistan and affected more than 20 million people. To characterize the impact of the floods and subsequent humanitarian response on household economy and food security. A cross-sectional 80 x 20 cluster survey (n = 1,569 households) was conducted using probability proportional to size sampling in the four most flood-affected provinces 6 months after the floods. Analysis included both descriptive statistics and regression models, with receipt of food aid (in the first month), dietary quality, and household income at 6 months postflood as outcomes. Need for food aid was nearly ubiquitous (98.9%); however, only half of the study population ever received food aid. Displacement was not a significant predictor of food aid receipt (OR, 1.28; 95% CI, 0.83 to 1.98); however urban location (OR, 2.78; 95% CI, 2.00 to 3.86) and damage to the home (OR, 2.73; 95% CI, 1.34 to 5.60) were significantly associated. Some of the hardest-hit groups, including both farmers and day laborers, were significantly less likely to receive food aid (p < .05). Additionally, receipt of food aid was not necessarily associated with improved household economy or food security; although households in internally displaced people (IDP) camps were more likely to receive food aid (OR, 2.78; 95% CI, 2.00 to 3.86), they were less likely to report same or improved dietary quality (OR, 0.63; 95% CI, 0.46 to 0.88) or income status (OR, 0.55; 95% CI, 0.35 to 0.86). Food aid coverage following the 2010 floods was relatively low, and many of the most affected populations were less likely to receive aid, suggesting that targeting should be improved in future responses.

Flash flood disasters analysis and evaluation: a case study of Yiyang County in China

NASA Astrophysics Data System (ADS)

Li, Haichen; Zhang, Xiaolei; Li, Qing; Qin, Tao; Lei, Xiaohui

2018-03-01

Global climate change leads to the more extreme precipitation and more flash flood disasters, which is a serious threat to the mountain inhabitants. To prevent flash flood disasters, China started flash flood disaster control planning and other projects from 2006. Among those measures, non-engineering measures are effective and economical. This paper introduced the framework of flash flood disaster analysis and evaluation in China, followed by a case study of Yiyang County.

A new concept to study the effect of climate change on different flood types

NASA Astrophysics Data System (ADS)

Nissen, Katrin; Nied, Manuela; Pardowitz, Tobias; Ulbrich, Uwe; Merz, Bruno

2014-05-01

Flooding is triggered by the interaction of various processes. Especially important are the hydrological conditions prior to the event (e.g. soil saturation, snow cover) and the meteorological conditions during flood development (e.g. rainfall, temperature). Depending on these (pre-) conditions different flood types may develop such as long-rain floods, short-rain floods, flash floods, snowmelt floods and rain-on-snow floods. A new concept taking these factors into account is introduced and applied to flooding in the Elbe River basin. During the period September 1957 to August 2002, 82 flood events are identified and classified according to their flood type. The hydrological and meteorological conditions at each day during the analysis period are detemined. In case of the hydrological conditions, a soil moisture pattern classification is carried out. Soil moisture is simulated with a rainfall-runoff model driven by atmospheric observations. Days of similar soil moisture patterns are identified by a principle component analysis and a subsequent cluster analysis on the leading principal components. The meteorological conditions are identified by applying a cluster analysis to the geopotential height, temperature and humidity fields of the ERA40 reanalysis data set using the SANDRA cluster algorithm. We are able to identify specific pattern combinations of hydrological pre-conditions and meteorological conditions which favour different flood types. Based on these results it is possible to analyse the effect of climate change on different flood types. As an example we show first results obtained using an ensemble of climate scenario simulations of ECHAM5 MPIOM model, taking only the changes in the meteorological conditions into account. According to the simulations, the frequency of the meteorological patterns favouring long-rain, short-rain and flash floods will not change significantly under future climate conditions. A significant increase is, however, predicted for the amount of precipitation associated with many of the relevant meteorological patterns. The increase varies between 12 and 67% depending on the weather pattern.

An analysis of the public perception of flood risk on the Belgian coast.

PubMed

Kellens, Wim; Zaalberg, Ruud; Neutens, Tijs; Vanneuville, Wouter; De Maeyer, Philippe

2011-07-01

In recent years, perception of flood risks has become an important topic to policy makers concerned with risk management and safety issues. Knowledge of the public risk perception is considered a crucial aspect in modern flood risk management as it steers the development of effective and efficient flood mitigation strategies. This study aimed at gaining insight into the perception of flood risks along the Belgian coast. Given the importance of the tourism industry on the Belgian coast, the survey considered both inhabitants and residential tourists. Based on actual expert's risk assessments, a high and a low risk area were selected for the study. Risk perception was assessed on the basis of scaled items regarding storm surges and coastal flood risks. In addition, various personal and residence characteristics were measured. Using multiple regression analysis, risk perception was found to be primarily influenced by actual flood risk estimates, age, gender, and experience with previous flood hazards. © 2011 Society for Risk Analysis.

Policy tenure under the U.S. National Flood Insurance Program (NFIP).

PubMed

Michel-Kerjan, Erwann; Lemoyne de Forges, Sabine; Kunreuther, Howard

2012-04-01

In the United States, insurance against flood hazard (inland flooding or storm surge from hurricanes) has been provided mainly through the National Flood Insurance Program (NFIP) since 1968. The NFIP covers $1.23 trillion of assets today. This article provides the first analysis of flood insurance tenure ever undertaken: that is, the number of years that people keep their flood insurance policy before letting it lapse. Our analysis of the entire portfolio of the NFIP over the period 2001-2009 reveals that the median tenure of new policies during that time is between two and four years; it is also relatively stable over time and levels of flood hazard. Prior flood experience can affect tenure: people who have experienced small flood claims tend to hold onto their insurance longer; people who have experienced large flood claims tend to let their insurance lapse sooner. To overcome the policy and governance challenges posed by homeowners' inadequate insurance coverage, we discuss policy recommendations that include for banks and government-sponsored enterprises (GSEs) strengthening their requirements and the introduction of multiyear flood insurance contracts attached to the property, both of which are likely to provide more coverage stability and encourage investments in risk-reduction measures. © 2011 Society for Risk Analysis.

Floods and climate: emerging perspectives for flood risk assessment and management

NASA Astrophysics Data System (ADS)

Merz, B.; Aerts, J.; Arnbjerg-Nielsen, K.; Baldi, M.; Becker, A.; Bichet, A.; Blöschl, G.; Bouwer, L. M.; Brauer, A.; Cioffi, F.; Delgado, J. M.; Gocht, M.; Guzzetti, F.; Harrigan, S.; Hirschboeck, K.; Kilsby, C.; Kron, W.; Kwon, H.-H.; Lall, U.; Merz, R.; Nissen, K.; Salvatti, P.; Swierczynski, T.; Ulbrich, U.; Viglione, A.; Ward, P. J.; Weiler, M.; Wilhelm, B.; Nied, M.

2014-07-01

Flood estimation and flood management have traditionally been the domain of hydrologists, water resources engineers and statisticians, and disciplinary approaches abound. Dominant views have been shaped; one example is the catchment perspective: floods are formed and influenced by the interaction of local, catchment-specific characteristics, such as meteorology, topography and geology. These traditional views have been beneficial, but they have a narrow framing. In this paper we contrast traditional views with broader perspectives that are emerging from an improved understanding of the climatic context of floods. We come to the following conclusions: (1) extending the traditional system boundaries (local catchment, recent decades, hydrological/hydraulic processes) opens up exciting possibilities for better understanding and improved tools for flood risk assessment and management. (2) Statistical approaches in flood estimation need to be complemented by the search for the causal mechanisms and dominant processes in the atmosphere, catchment and river system that leave their fingerprints on flood characteristics. (3) Natural climate variability leads to time-varying flood characteristics, and this variation may be partially quantifiable and predictable, with the perspective of dynamic, climate-informed flood risk management. (4) Efforts are needed to fully account for factors that contribute to changes in all three risk components (hazard, exposure, vulnerability) and to better understand the interactions between society and floods. (5) Given the global scale and societal importance, we call for the organization of an international multidisciplinary collaboration and data-sharing initiative to further understand the links between climate and flooding and to advance flood research.

Changing pattern of natural hazards due to extreme hydro-meteorological conditions (Apulia, southern Italy)

NASA Astrophysics Data System (ADS)

Polemio, Maurizio; Lonigro, Teresa

2013-04-01

Recent international researches have underlined the evidences of climate changes throughout the world. Among the consequences of climate change, there is the increase in the frequency and magnitude of natural disasters, such as droughts, windstorms, heat waves, landslides, floods and secondary floods (i.e. rapid accumulation or pounding of surface water with very low flow velocity). The Damaging Hydrogeological Events (DHEs) can be defined as the occurrence of one or more simultaneous aforementioned phenomena causing damages. They represent a serious problem, especially in DHE-prone areas with growing urbanisation. In these areas the increasing frequency of extreme hydrological events could be related to climate variations and/or urban development. The historical analysis of DHEs can support decision making and land-use planning, ultimately reducing natural risks. The paper proposes a methodology, based on both historical and time series approaches, used for describing the influence of climatic variability on the number of phenomena observed. The historical approach is finalised to collect phenomenon historical data. The historical flood and landslide data are important for the comprehension of the evolution of a study area and for the estimation of risk scenarios as a basis for civil protection purposes. Phenomenon historical data is useful for expanding the historical period of investigation in order to assess the occurrence trend of DHEs. The time series approach includes the collection and the statistical analysis of climatic and rainfall data (monthly rainfall, wet days, rainfall intensity, and temperature data together with the annual maximum of short-duration rainfall data, from 1 hour to 5 days), which are also used as a proxy for floods and landslides. The climatic and rainfall data are useful to characterise the climate variations and trends and to roughly assess the effects of these trends on river discharge and on the triggering of landslides. The time series approach is completed by tools to analyse simultaneously all data types. The methodology was tested considering a selected Italian region (Apulia, southern Italy). The data were collected in two databases: a damaging hydrogeological event database (1186 landslides and floods since 1918) and a climate database (from 1877; short-duration rainfall from 1921). A statistically significant decreasing trend of rainfall intensity and an increasing trend of temperature, landslides, and DHEs were observed. A generalised decreasing trend of short-duration rainfall was observed. If there is not an evident relationship between climate variability and the variability of DHE occurrences, the role of anthropogenic modifications (increasing use or misuse of flood- and landslide-prone areas) could be hypothesized to justify the increasing occurrences of floods and landslides.. This study identifies the advantages of a simplifying approach to reduce the intrinsic complexities of the spatial-temporal analysis of climate variability, permitting the simultaneous analysis of the modification of flood and landslide occurrences.

Evaluating the effects of dam breach methodologies on Consequence Estimation through Sensitivity Analysis

NASA Astrophysics Data System (ADS)

Kalyanapu, A. J.; Thames, B. A.

2013-12-01

Dam breach modeling often includes application of models that are sophisticated, yet computationally intensive to compute flood propagation at high temporal and spatial resolutions. This results in a significant need for computational capacity that requires development of newer flood models using multi-processor and graphics processing techniques. Recently, a comprehensive benchmark exercise titled the 12th Benchmark Workshop on Numerical Analysis of Dams, is organized by the International Commission on Large Dams (ICOLD) to evaluate the performance of these various tools used for dam break risk assessment. The ICOLD workshop is focused on estimating the consequences of failure of a hypothetical dam near a hypothetical populated area with complex demographics, and economic activity. The current study uses this hypothetical case study and focuses on evaluating the effects of dam breach methodologies on consequence estimation and analysis. The current study uses ICOLD hypothetical data including the topography, dam geometric and construction information, land use/land cover data along with socio-economic and demographic data. The objective of this study is to evaluate impacts of using four different dam breach methods on the consequence estimates used in the risk assessments. The four methodologies used are: i) Froehlich (1995), ii) MacDonald and Langridge-Monopolis 1984 (MLM), iii) Von Thun and Gillete 1990 (VTG), and iv) Froehlich (2008). To achieve this objective, three different modeling components were used. First, using the HEC-RAS v.4.1, dam breach discharge hydrographs are developed. These hydrographs are then provided as flow inputs into a two dimensional flood model named Flood2D-GPU, which leverages the computer's graphics card for much improved computational capabilities of the model input. Lastly, outputs from Flood2D-GPU, including inundated areas, depth grids, velocity grids, and flood wave arrival time grids, are input into HEC-FIA, which provides the consequence assessment for the solution to the problem statement. For the four breach methodologies, a sensitivity analysis of four breach parameters, breach side slope (SS), breach width (Wb), breach invert elevation (Elb), and time of failure (tf), is conducted. Up to, 68 simulations are computed to produce breach hydrographs in HEC-RAS for input into Flood2D-GPU. The Flood2D-GPU simulation results were then post-processed in HEC-FIA to evaluate: Total Population at Risk (PAR), 14-yr and Under PAR (PAR14-), 65-yr and Over PAR (PAR65+), Loss of Life (LOL) and Direct Economic Impact (DEI). The MLM approach resulted in wide variability in simulated minimum and maximum values of PAR, PAR 65+ and LOL estimates. For PAR14- and DEI, Froehlich (1995) resulted in lower values while MLM resulted in higher estimates. This preliminary study demonstrated the relative performance of four commonly used dam breach methodologies and their impacts on consequence estimation.

Numerical Analysis of Flood modeling of upper Citarum River under Extreme Flood Condition

NASA Astrophysics Data System (ADS)

Siregar, R. I.

2018-02-01

This paper focuses on how to approach the numerical method and computation to analyse flood parameters. Water level and flood discharge are the flood parameters solved by numerical methods approach. Numerical method performed on this paper for unsteady flow conditions have strengths and weaknesses, among others easily applied to the following cases in which the boundary irregular flow. The study area is in upper Citarum Watershed, Bandung, West Java. This paper uses computation approach with Force2 programming and HEC-RAS to solve the flow problem in upper Citarum River, to investigate and forecast extreme flood condition. Numerical analysis based on extreme flood events that have occurred in the upper Citarum watershed. The result of water level parameter modeling and extreme flood discharge compared with measurement data to analyse validation. The inundation area about flood that happened in 2010 is about 75.26 square kilometres. Comparing two-method show that the FEM analysis with Force2 programs has the best approach to validation data with Nash Index is 0.84 and HEC-RAS that is 0.76 for water level. For discharge data Nash Index obtained the result analysis use Force2 is 0.80 and with use HEC-RAS is 0.79.

Proteomic analysis of soybean hypocotyl during recovery after flooding stress.

PubMed

Khan, Mudassar Nawaz; Sakata, Katsumi; Komatsu, Setsuko

2015-05-21

Soybean is a nutritionally important crop, but exhibits reduced growth and yields under flooding stress. To investigate soybean responses during post-flooding recovery, a gel-free proteomic technique was used to examine the protein profile in the hypocotyl. Two-day-old soybeans were flooded for 2 days and hypocotyl was collected under flooding and during the post-flooding recovery period. A total of 498 and 70 proteins were significantly changed in control and post-flooding recovering soybeans, respectively. Based on proteomic and clustering analyses, three proteins were selected for mRNA expression and enzyme activity assays. Pyruvate kinase was increased under flooding, but gradually decreased during post-flooding recovery period at protein abundance, mRNA, and enzyme activity levels. Nucleotidylyl transferase was decreased under flooding and increased during post-flooding recovery at both mRNA expression and enzyme activity levels. Beta-ketoacyl reductase 1 was increased under flooding and decreased during recovery at protein abundance and mRNA expression levels, but its enzyme activity gradually increased during the post-flooding recovery period. These results suggest that pyruvate kinase, nucleotidylyl transferase, and beta-ketoacyl reductase play key roles in post-flooding recovery in soybean hypocotyl by promoting glycolysis for the generation of ATP and regulation of secondary metabolic pathways. This study analyzed post-flooding recovery response mechanisms in soybean hypocotyl, which is a model organ for studying secondary growth, using a gel-free proteomic technique. Mass spectrometry analysis of proteins extracted from soybean hypocotyls identified 20 common proteins between control and flooding-stressed soybeans that changed significantly in abundance over time. The hypocotyl proteins that changed during post-flooding recovery were assigned to protein, development, secondary metabolism, and glycolysis categories. The analysis revealed that three proteins, pyruvate kinase, nucleotidylyl transferase, and beta-ketoacyl reductase, were increased in hypocotyl under flooding conditions and during post-flooding recovery. The proteins are involved in glycolysis, nucleotide synthesis and amino acid activation, and complex fatty acid biosynthesis. Copyright © 2015 Elsevier B.V. All rights reserved.

[Study on influence of floods on bacillary dysentery incidence in Liaoning province, 2004 -2010].

PubMed

Xu, X; Liu, Z D; Han, D B; Xu, Y Q; Jiang, B F

2016-05-01

To understand the influence of floods on bacillary dysentery in Liaoning province. The monthly surveillance data of bacillary dysentery, floods, meteorological and demographic data in Liaoning from 2004 to 2010 were collected. Panel Poisson regression analysis was conducted to evaluate the influence of floods on the incidence of bacillary dysentery in Liaoning. The mean monthly morbidity of bacillary dysentery was 2.17 per 100 000 during the study period, the bacillary dysentery cases mainly occurred in during July-September. Spearman correlation analysis showed that no lagged effect was detected in the influence of floods on the incidence of bacillary dysentery. After adjusting the influence of meteorological factors, panel data analysis showed that the influence of floods on the incidence of bacillary dysentery existed and the incidence rate ratio was 1.439 4(95%CI: 1.408 1-1.471 4). Floods could significantly increase the risk of bacillary dysentery for population in Liaoning.

Hydrology Analysis and Modelling for Klang River Basin Flood Hazard Map

NASA Astrophysics Data System (ADS)

Sidek, L. M.; Rostam, N. E.; Hidayah, B.; Roseli, ZA; Majid, W. H. A. W. A.; Zahari, N. Z.; Salleh, S. H. M.; Ahmad, R. D. R.; Ahmad, M. N.

2016-03-01

Flooding, a common environmental hazard worldwide has in recent times, increased as a result of climate change and urbanization with the effects felt more in developing countries. As a result, the explosive of flooding to Tenaga Nasional Berhad (TNB) substation is increased rapidly due to existing substations are located in flood prone area. By understanding the impact of flood to their substation, TNB has provided the non-structure mitigation with the integration of Flood Hazard Map with their substation. Hydrology analysis is the important part in providing runoff as the input for the hydraulic part.

Development and validation of a 2D dam break process model

USDA-ARS?s Scientific Manuscript database

Flooding due to dam or levee breach often results in detrimental impact on the people and their properties in the flooding zone. The embankment breach process is often caused by overtopping or internal erosion due to excessive water in a reservoir or a river. This study is to develop a practical nu...

Exploring Droughts and Floods and Their Association with Cholera Outbreaks in Sub-Saharan Africa: A Register-Based Ecological Study from 1990 to 2010

PubMed Central

Rieckmann, Andreas; Tamason, Charlotte C.; Gurley, Emily S.; Rod, Naja Hulvej; Jensen, Peter Kjær Mackie

2018-01-01

Abstract. Cholera outbreaks in Africa have been attributed to both droughts and floods, but whether the risk of a cholera outbreak is elevated during droughts is unknown. We estimated the risk of cholera outbreaks during droughts and floods compared with drought- and flood-free periods in 40 sub-Saharan African countries during 1990–2010 based on data from Emergency Events Database: the Office of Foreign Disaster Assistance /Centre for Research on the Epidemiology of Disasters International Disaster Database (www.emdat.be). A cholera outbreak was registered in one of every three droughts and one of every 15 floods. We observed an increased incidence rate of cholera outbreaks during drought periods (incidence rate ratio [IRR] = 4.3, 95% confidence interval [CI] = 2.9–7.2) and during flood periods (IRR = 144, 95% CI = 101–208) when compared with drought/flood-free periods. Floods are more strongly associated with cholera outbreaks, yet the prevalence of cholera outbreaks is higher during droughts because of droughts’ long durations. The results suggest that droughts in addition to floods call for increased cholera preparedness. PMID:29512484

Flood susceptibility analysis through remote sensing, GIS and frequency ratio model

NASA Astrophysics Data System (ADS)

Samanta, Sailesh; Pal, Dilip Kumar; Palsamanta, Babita

2018-05-01

Papua New Guinea (PNG) is saddled with frequent natural disasters like earthquake, volcanic eruption, landslide, drought, flood etc. Flood, as a hydrological disaster to humankind's niche brings about a powerful and often sudden, pernicious change in the surface distribution of water on land, while the benevolence of flood manifests in restoring the health of the thalweg from excessive siltation by redistributing the fertile sediments on the riverine floodplains. In respect to social, economic and environmental perspective, flood is one of the most devastating disasters in PNG. This research was conducted to investigate the usefulness of remote sensing, geographic information system and the frequency ratio (FR) for flood susceptibility mapping. FR model was used to handle different independent variables via weighted-based bivariate probability values to generate a plausible flood susceptibility map. This study was conducted in the Markham riverine precinct under Morobe province in PNG. A historical flood inventory database of PNG resource information system (PNGRIS) was used to generate 143 flood locations based on "create fishnet" analysis. 100 (70%) flood sample locations were selected randomly for model building. Ten independent variables, namely land use/land cover, elevation, slope, topographic wetness index, surface runoff, landform, lithology, distance from the main river, soil texture and soil drainage were used into the FR model for flood vulnerability analysis. Finally, the database was developed for areas vulnerable to flood. The result demonstrated a span of FR values ranging from 2.66 (least flood prone) to 19.02 (most flood prone) for the study area. The developed database was reclassified into five (5) flood vulnerability zones segmenting on the FR values, namely very low (less that 5.0), low (5.0-7.5), moderate (7.5-10.0), high (10.0-12.5) and very high susceptibility (more than 12.5). The result indicated that about 19.4% land area as `very high' and 35.8% as `high' flood vulnerable class. The FR model output was validated with remaining 43 (30%) flood points, where 42 points were marked as correct predictions which evinced an accuracy of 97.7% in prediction. A total of 137292 people are living in those vulnerable zones. The flood susceptibility analysis using this model will be very useful and also an efficient tool to the local government administrators, researchers and planners for devising flood mitigation plans.

"Know What to Do If You Encounter a Flash Flood": Mental Models Analysis for Improving Flash Flood Risk Communication and Public Decision Making.

PubMed

Lazrus, Heather; Morss, Rebecca E; Demuth, Julie L; Lazo, Jeffrey K; Bostrom, Ann

2016-02-01

Understanding how people view flash flood risks can help improve risk communication, ultimately improving outcomes. This article analyzes data from 26 mental models interviews about flash floods with members of the public in Boulder, Colorado, to understand their perspectives on flash flood risks and mitigation. The analysis includes a comparison between public and professional perspectives by referencing a companion mental models study of Boulder-area professionals. A mental models approach can help to diagnose what people already know about flash flood risks and responses, as well as any critical gaps in their knowledge that might be addressed through improved risk communication. A few public interviewees mentioned most of the key concepts discussed by professionals as important for flash flood warning decision making. However, most interviewees exhibited some incomplete understandings and misconceptions about aspects of flash flood development and exposure, effects, or mitigation that may lead to ineffective warning decisions when a flash flood threatens. These include important misunderstandings about the rapid evolution of flash floods, the speed of water in flash floods, the locations and times that pose the greatest flash flood risk in Boulder, the value of situational awareness and environmental cues, and the most appropriate responses when a flash flood threatens. The findings point to recommendations for ways to improve risk communication, over the long term and when an event threatens, to help people quickly recognize and understand threats, obtain needed information, and make informed decisions in complex, rapidly evolving extreme weather events such as flash floods. © 2015 Society for Risk Analysis.

Hydraulic description of a flood event with optical remote sensors: a constructive constraint on modelling uncertainties

NASA Astrophysics Data System (ADS)

Battiston, Stéphanie; Allenbach, Bernard

2010-05-01

The exceptional characteristics of the December 2003 Rhône flood event (particularly high water flows, extent of the affected area, important damages especially in the region of Arles) make it be considered as a reference flood episode of this French river and a very well-known event. During the crisis, the International Charter "Space and Major Disasters" was triggered by the French Civil Protection for the rapid mapping of the flooding using Earth Observation imagery in order to facilitate crisis operations. As a result, more than 60 satellite images covering the flood were acquired over a 10 days period following the peak flow. Using the opportunity provided by this incomparable data coverage, the French Ministry of the Environment ordered a study on the evaluation of remote sensing's potential benefits for flood management. One of the questions asked by the risk managers was: what type of flood information can be provided by the different remote sensing platforms? Elements of response were delivered mainly in the form of a comprehensive compilation of maps and illustrations, displaying the main hydraulic elements (static ones as well as dynamic ones), initially listed and requested by hydrologists (more precisely, by a regional engineering society specialised in hydraulics and hydrology and in charge of a field campaign during the event), observed on different optical images of the flood event having affected the plain between Tarascon (upstream) and Arles (downstream). It is seen that a careful mapping of all flood traces visible on remote sensing event imagery - apparent water, moisture traces, breaches, overflows, stream directions, impermeable boundaries … - delivers a valuable vision of the flood's occurrence combining accuracy and comprehensiveness. In fact, optical imagery offers a detailed vision of the event : moisture traces complete flood traces extent; the observation of draw-off directions through waterproof barriers reveals hydraulic compartments; high resolution optical imagery allow the exhaustive inventory of breaches and overflows; turbidity variations and draw-off give information on stream directions. These facts are of primary interest to help in deriving a firm understanding of the flooding processes, but also comprise a powerful source for the necessary parameterization and/or calibration of hydraulic models. Thus the accuracy of flood extents derived from remote sensing data could, on the one hand, be valuable inputs to historical flood info-bases within overall risk-linked databases, and on the other hand, test the validity of hydrological modelling, while helping to lift equifinality uncertainties. These first investigations highlight that space imagery of events constitutes an unrivalled tool for flood disaster observation. This 2D record is complementary to all field measurements and the integration of "space derived flood products" is valuable for all stages of risk management. This potential of EO optical sensors for flood monitoring is also confirmed in a detailed analysis making a qualitative and quantitative evaluation of the results, confronting ten optical and radar remote sensing platforms with field observations.

Comparison of recent sedimentation patterns in Mondsee and Hallstätter See (Upper Austria) and implications for palaeoflood reconstructions in the Eastern European Alps

NASA Astrophysics Data System (ADS)

Lauterbach, Stefan; Kämpf, Lucas; Swierczynski, Tina; Tjallingii, Rik; Brauer, Achim

2017-04-01

Rainfall-triggered flood events represent one of the most serious societal and economic threats in Central Europe. Nevertheless, the thorough assessment of this hazard is still limited by the restricted knowledge about the long-term spatio-temporal recurrence patterns and complex climatic trigger mechanisms of extreme flood events. As instrumental and documentary flood time series rarely exceed a few hundred years, long and precisely dated palaeoflood records from natural archives, e.g. lake sediments, offer an excellent opportunity to gain important information about long-term flood dynamics. This can improve the understanding of flood occurrence under different climatic boundary conditions as well as flood-generating processes and thus allow a more reliable assessment of future flood scenarios. However, the spatial coverage of lake sediment palaeoflood records across Europe is still limited and individual lakes are very heterogeneous in their sedimentological response and sensitivity to flooding. It therefore remains questionable whether single lake sediment palaeoflood records are representative on a larger spatial scale. Investigating adjacent lakes in terms of their individual flood response can therefore (1) help to improve the understanding of key hydro-climatological variables and lake internal processes, both controlling flood layer deposition, and (2) allow to assess the completeness and representativeness of single palaeoflood records, particularly with regard to different flood seasonality. Here we present first data from a project aiming at establishing a new palaeoflood record for the Eastern Alps by investigating the sediments of Hallstätter See in the Calcareous Alps of Upper Austria. These are compared with results from adjacent Mondsee (ca. 35 km to the northwest), located at the northern fringe of the Calcareous Alps. The recent sediments from these two lakes have been investigated with respect to their reflection of large flood events by using detailed sediment microfacies analysis on large-scale thin sections and high-resolution µ-XRF scanning. The depositional environment in Hallstätter See is mainly controlled by seasonally variable and largely runoff-triggered input of allochthonous clastic-detrital material by the Traun River, a major tributary of the Danube. In consequence, the sediments reveal a complex cm- to sub-mm-scale lamination, reflecting detrital input by frequent individual runoff events that are not necessarily extreme floods. This largely contrasts the depositional environment in Mondsee, where detrital material delivered through the relatively small tributaries is intercalated within the regular endogenic calcite varves only during major flood events. This comparison highlights that both lake systems are very different in their response to flooding, depending on catchment geology and morphology, tributary characteristics as well as flood seasonality. Hence, even for lakes in the same climatic domain, the comparison of resulting palaeoflood records is not necessarily straightforward since every lake sediment record only reflects certain aspects of regional flood history, strongly influenced by the individual characteristics of the lake system.

Long-term, high-frequency current and temperature measurements along central California: Insights into upwelling/relaxation and internal waves on the inner shelf

USGS Publications Warehouse

Storlazzi, C.D.; McManus, M.A.; Figurski, J.D.

2003-01-01

Thermistor chains and acoustic Doppler current profilers were deployed at the northern and southern ends of Monterey Bay to examine the thermal and hydrodynamic structure of the inner (h ??? 20 m) shelf of central California. These instruments sampled temperature and current velocity at 2-min intervals over a 13-month period from June 2000 to July 2001. Time series of these data, in conjunction with SST imagery and CODAR sea surface current maps, helped to establish the basic hydrography for Monterey Bay. Analysis of time series data revealed that depth integrated flow at both sites was shore parallel (northwest-southeast) with net flows out of the Bay (northwest). The current and temperature records were dominated by semi-diurnal and diurnal tidal signals that lagged the surface tides by 3 h on average. Over the course of an internal tidal cycle these flows were asymmetric, with the flow during the flooding internal tide to the southeast typically lasting only one-third as long as the flow to the northwest during the ebbing internal tide. The transitions from ebb to flood were rapid and bore-like in nature; they were also marked by rapid increases in temperature and high shear. During the spring and summer, when thermal stratification was high, we observed almost 2000 high-frequency (Tp ??? 4-20 min) internal waves in packets of 8-10 following the heads of these bore-like features. Previous studies along the West Coast of the US have concluded that warm water bores and high-frequency internal waves may play a significant role in the onshore transport of larvae.

Cane Creek flood-flow characteristics at State Route 30 near Spencer, Tennessee

USGS Publications Warehouse

Gamble, Charles R.

1983-01-01

The Tennessee Department of Transportation has constructed a new bridge and approaches on State Route 30 over Cane Creek near Spencer, Tennessee. The old bridge and its approaches were fairly low, permitting considerable flow over the road during high floods. The new bridge and its approaches are considerably higher, causing different flow conditions at the site. Analysis of the effects of the new bridge, as compared to the old bridge, on floods of the magnitude of the May 27, 1973, flood is presented. The May 27, 1973, flood was greater than a 100-year flood. Analysis of the 50- and 100-year floods for the new bridge are also presented. Results of the study indicate that the new construction will increase the water-surface elevation for a flood equal to the May 27, 1973, flood by approximately 1 foot upstream from bridge. (USGS)

Topography- and nightlight-based national flood risk assessment in Canada

NASA Astrophysics Data System (ADS)

Elshorbagy, Amin; Bharath, Raja; Lakhanpal, Anchit; Ceola, Serena; Montanari, Alberto; Lindenschmidt, Karl-Erich

2017-04-01

In Canada, flood analysis and water resource management, in general, are tasks conducted at the provincial level; therefore, unified national-scale approaches to water-related problems are uncommon. In this study, a national-scale flood risk assessment approach is proposed and developed. The study focuses on using global and national datasets available with various resolutions to create flood risk maps. First, a flood hazard map of Canada is developed using topography-based parameters derived from digital elevation models, namely, elevation above nearest drainage (EAND) and distance from nearest drainage (DFND). This flood hazard mapping method is tested on a smaller area around the city of Calgary, Alberta, against a flood inundation map produced by the city using hydraulic modelling. Second, a flood exposure map of Canada is developed using a land-use map and the satellite-based nightlight luminosity data as two exposure parameters. Third, an economic flood risk map is produced, and subsequently overlaid with population density information to produce a socioeconomic flood risk map for Canada. All three maps of hazard, exposure, and risk are classified into five classes, ranging from very low to severe. A simple way to include flood protection measures in hazard estimation is also demonstrated using the example of the city of Winnipeg, Manitoba. This could be done for the entire country if information on flood protection across Canada were available. The evaluation of the flood hazard map shows that the topography-based method adopted in this study is both practical and reliable for large-scale analysis. Sensitivity analysis regarding the resolution of the digital elevation model is needed to identify the resolution that is fine enough for reliable hazard mapping, but coarse enough for computational tractability. The nightlight data are found to be useful for exposure and risk mapping in Canada; however, uncertainty analysis should be conducted to investigate the effect of the overglow phenomenon on flood risk mapping.

Combined fluvial and pluvial urban flood hazard analysis: method development and application to Can Tho City, Mekong Delta, Vietnam

NASA Astrophysics Data System (ADS)

Apel, H.; Trepat, O. M.; Hung, N. N.; Chinh, D. T.; Merz, B.; Dung, N. V.

2015-08-01

Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas, and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either fluvial or pluvial flood hazard, studies of combined fluvial and pluvial flood hazard are hardly available. Thus this study aims at the analysis of fluvial and pluvial flood hazard individually, but also at developing a method for the analysis of combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as example. In this tropical environment the annual monsoon triggered floods of the Mekong River can coincide with heavy local convective precipitation events causing both fluvial and pluvial flooding at the same time. Fluvial flood hazard was estimated with a copula based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. Pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data, and a stochastic rain storm generator. Inundation was simulated by a 2-dimensional hydrodynamic model implemented on a Graphical Processor Unit (GPU) for time-efficient flood propagation modelling. All hazards - fluvial, pluvial and combined - were accompanied by an uncertainty estimation considering the natural variability of the flood events. This resulted in probabilistic flood hazard maps showing the maximum inundation depths for a selected set of probabilities of occurrence, with maps showing the expectation (median) and the uncertainty by percentile maps. The results are critically discussed and ways for their usage in flood risk management are outlined.

On the suitability of the copula types for the joint modelling of flood peaks and volumes along the Danube River

NASA Astrophysics Data System (ADS)

Kohnová, Silvia; Papaioannou, George; Bacigál, Tomáš; Szolgay, Ján; Hlavčová, Kamila; Loukas, Athanasios; Výleta, Roman

2017-04-01

Flood frequency analysis is often performed as a univariate analysis of flood peaks using a suitable theoretical probability distribution of the annual maximum flood peaks or peak over threshold values. However, also other flood attributes, such as flood volume and duration, are often necessary for the design of hydrotechnical structures and projects. In this study, the suitability of various copula families for a bivariate analysis of peak discharges and flood volumes has been tested on the streamflow data from gauging stations along the whole Danube River. Kendall's rank correlation coefficient (tau) quantifies the dependence between flood peak discharge and flood volume settings. The methodology is tested on two different data samples: 1) annual maximum flood (AMF) peaks with corresponding flood volumes, which is a typical choice for engineering studies and 2). annual maximum flood (AMF) peaks combined with annual maximum flow volumes of fixed durations at 5, 10, 15, 20, 25, 30 and 60 days, which can be regarded as a regime analysis of the dependence between the extremes of both variables in a given year. The bivariate modelling of the peak discharge - flood volume couples is achieved with the use of the the following copulas: Ali-Mikhail-Haq (AMH), Clayton, Frank, Joe, Gumbel, HuslerReiss, Galambos, Tawn, Normal, Plackett and FGM, respectively. Scatterplots of the observed and simulated peak discharge - flood volume pairs and goodness-of-fit tests have been used to assess the overall applicability of the copulas as well as observing any changes in suitable models along the Danube River. The results indicate that, almost all of the considered Archimedean class copulas (e.g. Frank, Clayton and Ali-Mikhail-Haq) perform better than the other copula families selected for this study, and that for the second data samples mostly the upper-tail-flat copulas were suitable.

Determination of Flood Reduction Alternatives for Climate Change Adaptation in Gyeongancheon basin

NASA Astrophysics Data System (ADS)

Han, D.; Joo, H. J.; Jung, J.; Kim, H. S.

2017-12-01

Recently, the frequency of extreme rainfall event has increased due to the climate change and the impermeable area in an urban watershed has also increased due to the rapid urbanization. Therefore, the flood risk is increasing and we ought to prepare countermeasures for flood damage reduction. For the determination of appropriate measures or alternatives, firstly, this study estimated the frequency based rainfall considering the climate change according to the each target period(reference : 1971˜2010, Target period Ⅰ : 2011˜2040, Target period Ⅱ : 2041˜2070, Target period Ⅲ : 2071˜2100). Then the future flood discharge was computed by using HEC-HMS model. We set 5 sizes of drainage pumps and detention ponds respectively as the flood reduction alternatives and the flood level in the river was obtained by each alternative through HEC-RAS model. The flood inundation map was constructed using topographical data and flood water level in the river and the economic analysis was conducted for the flood damage reduction studies using Multi Dimensional Flood Damage Analysis (MD-FDA) tool. As a result of the effectiveness analysis of the flood reduction alternatives, the flood level by drainage pump was reduced by 0.06m up to 0.44m while it was reduced by 0.01m up to 1.86m in the case of the detention pond. The flooded area was shrunk by up to 32.64% from 0.3% and inundation depth was also dropped. As a result of a comparison of the Benefit/Cost ratio estimated by the economic analysis, a detention pond E in the target period Ⅰ and the pump D in the periods Ⅱ and Ⅲ were considered as the appropriate alternatives for the flood damage reduction under the climate change. AcknowledgementsThis research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(2017R1A2B3005695)

Large Scale Flood Risk Analysis using a New Hyper-resolution Population Dataset

NASA Astrophysics Data System (ADS)

Smith, A.; Neal, J. C.; Bates, P. D.; Quinn, N.; Wing, O.

2017-12-01

Here we present the first national scale flood risk analyses, using high resolution Facebook Connectivity Lab population data and data from a hyper resolution flood hazard model. In recent years the field of large scale hydraulic modelling has been transformed by new remotely sensed datasets, improved process representation, highly efficient flow algorithms and increases in computational power. These developments have allowed flood risk analysis to be undertaken in previously unmodeled territories and from continental to global scales. Flood risk analyses are typically conducted via the integration of modelled water depths with an exposure dataset. Over large scales and in data poor areas, these exposure data typically take the form of a gridded population dataset, estimating population density using remotely sensed data and/or locally available census data. The local nature of flooding dictates that for robust flood risk analysis to be undertaken both hazard and exposure data should sufficiently resolve local scale features. Global flood frameworks are enabling flood hazard data to produced at 90m resolution, resulting in a mis-match with available population datasets which are typically more coarsely resolved. Moreover, these exposure data are typically focused on urban areas and struggle to represent rural populations. In this study we integrate a new population dataset with a global flood hazard model. The population dataset was produced by the Connectivity Lab at Facebook, providing gridded population data at 5m resolution, representing a resolution increase over previous countrywide data sets of multiple orders of magnitude. Flood risk analysis undertaken over a number of developing countries are presented, along with a comparison of flood risk analyses undertaken using pre-existing population datasets.

Evaluation of various modelling approaches in flood routing simulation and flood area mapping

NASA Astrophysics Data System (ADS)

Papaioannou, George; Loukas, Athanasios; Vasiliades, Lampros; Aronica, Giuseppe

2016-04-01

An essential process of flood hazard analysis and mapping is the floodplain modelling. The selection of the modelling approach, especially, in complex riverine topographies such as urban and suburban areas, and ungauged watersheds may affect the accuracy of the outcomes in terms of flood depths and flood inundation area. In this study, a sensitivity analysis implemented using several hydraulic-hydrodynamic modelling approaches (1D, 2D, 1D/2D) and the effect of modelling approach on flood modelling and flood mapping was investigated. The digital terrain model (DTMs) used in this study was generated from Terrestrial Laser Scanning (TLS) point cloud data. The modelling approaches included 1-dimensional hydraulic-hydrodynamic models (1D), 2-dimensional hydraulic-hydrodynamic models (2D) and the coupled 1D/2D. The 1D hydraulic-hydrodynamic models used were: HECRAS, MIKE11, LISFLOOD, XPSTORM. The 2D hydraulic-hydrodynamic models used were: MIKE21, MIKE21FM, HECRAS (2D), XPSTORM, LISFLOOD and FLO2d. The coupled 1D/2D models employed were: HECRAS(1D/2D), MIKE11/MIKE21(MIKE FLOOD platform), MIKE11/MIKE21 FM(MIKE FLOOD platform), XPSTORM(1D/2D). The validation process of flood extent achieved with the use of 2x2 contingency tables between simulated and observed flooded area for an extreme historical flash flood event. The skill score Critical Success Index was used in the validation process. The modelling approaches have also been evaluated for simulation time and requested computing power. The methodology has been implemented in a suburban ungauged watershed of Xerias river at Volos-Greece. The results of the analysis indicate the necessity of sensitivity analysis application with the use of different hydraulic-hydrodynamic modelling approaches especially for areas with complex terrain.

Comparative Analysis of Immediate Response by National Disaster Management Systems of the U.S., Pakistan, and Turkey

DTIC Science & Technology

2014-06-01

incremental increase in contamination and pollution, construction of unsafe structures in flood-prone areas, adverse effects of income gap and poverty...them claim that climate change, contamination , ozone depletion, and biodiversity loss are major factors, others believe that the real causes for the...the international arena, as well as the host country, while the second one has very little physical protection and is often faced with food , water

Influence of risk factors and past events on flood resilience in coastal megacities: Comparative analysis of NYC and Shanghai.

PubMed

Xian, Siyuan; Yin, Jie; Lin, Ning; Oppenheimer, Michael

2018-01-01

Coastal flood protection measures have been widely implemented to improve flood resilience. However, protection levels vary among coastal megacities globally. This study compares the distinct flood protection standards for two coastal megacities, New York City and Shanghai, and investigates potential influences such as risk factors and past flood events. Extreme value analysis reveals that, compared to NYC, Shanghai faces a significantly higher flood hazard. Flood inundation analysis indicates that Shanghai has a higher exposure to extreme flooding. Meanwhile, Shanghai's urban development, population, and economy have increased much faster than NYC's over the last three decades. These risk factors provide part of the explanation for the implementation of a relatively high level of protection (e.g. reinforced concrete sea-wall designed for a 200-year flood return level) in Shanghai and low protection (e.g. vertical brick and stone walls and sand dunes) in NYC. However, individual extreme flood events (typhoons in 1962, 1974, and 1981) seem to have had a greater impact on flood protection decision-making in Shanghai, while NYC responded significantly less to past events (with the exception of Hurricane Sandy). Climate change, sea level rise, and ongoing coastal development are rapidly changing the hazard and risk calculus for both cities and both would benefit from a more systematic and dynamic approach to coastal protection. Copyright © 2017 Elsevier B.V. All rights reserved.

Metabolic profiles of flooding-tolerant mechanism in early-stage soybean responding to initial stress.

PubMed

Wang, Xin; Zhu, Wei; Hashiguchi, Akiko; Nishimura, Minoru; Tian, Jingkui; Komatsu, Setsuko

2017-08-01

Metabolomic analysis of flooding-tolerant mutant and abscisic acid-treated soybeans suggests that accumulated fructose might play a role in initial flooding tolerance through regulation of hexokinase and phosphofructokinase. Soybean is sensitive to flooding stress, which markedly reduces plant growth. To explore the mechanism underlying initial-flooding tolerance in soybean, mass spectrometry-based metabolomic analysis was performed using flooding-tolerant mutant and abscisic-acid treated soybeans. Among the commonly-identified metabolites in both flooding-tolerant materials, metabolites involved in carbohydrate and organic acid displayed same profile at initial-flooding stress. Sugar metabolism was highlighted in both flooding-tolerant materials with the decreased and increased accumulation of sucrose and fructose, respectively, compared to flooded soybeans. Gene expression of hexokinase 1 was upregulated in flooded soybean; however, it was downregulated in both flooding-tolerant materials. Metabolites involved in carbohydrate/organic acid and proteins related to glycolysis/tricarboxylic acid cycle were integrated. Increased protein abundance of phosphofructokinase was identified in both flooding-tolerant materials, which was in agreement with its enzyme activity. Furthermore, sugar metabolism was pointed out as the tolerant-responsive process at initial-flooding stress with the integration of metabolomics, proteomics, and transcriptomics. Moreover, application of fructose declined the increased fresh weight of plant induced by flooding stress. These results suggest that fructose might be the critical metabolite through regulation of hexokinase and phosphofructokinase to confer initial-flooding stress in soybean.

Comparative hazard analysis of processes leading to remarkable flash floods (France, 1930-1999)

NASA Astrophysics Data System (ADS)

Boudou, M.; Lang, M.; Vinet, F.; Cœur, D.

2016-10-01

Flash flood events are responsible for large economic losses and lead to fatalities every year in France. This is especially the case in the Mediterranean and oversea territories/departments of France, characterized by extreme hydro-climatological features and with a large part of the population exposed to flood risks. The recurrence of remarkable flash flood events, associated with high hazard intensity, significant damage and socio-political consequences, therefore raises several issues for authorities and risk management policies. This study aims to improve our understanding of the hazard analysis process in the case of four remarkable flood events: March 1930, October 1940, January 1980 and November 1999. Firstly, we present the methodology used to define the remarkability score of a flood event. Then, to identify the factors leading to a remarkable flood event, we explore the main parameters of the hazard analysis process, such as the meteorological triggering conditions, the return period of the rainfall and peak discharge, as well as some additional factors (initial catchment state, flood chronology, cascade effects, etc.). The results contribute to understanding the complexity of the processes leading to flood hazard and highlight the importance for risk managers of taking additional factors into account.

Estimated Flood Discharges and Map of Flood-Inundated Areas for Omaha Creek, near Homer, Nebraska, 2005

USGS Publications Warehouse

Dietsch, Benjamin J.; Wilson, Richard C.; Strauch, Kellan R.

2008-01-01

Repeated flooding of Omaha Creek has caused damage in the Village of Homer. Long-term degradation and bridge scouring have changed substantially the channel characteristics of Omaha Creek. Flood-plain managers, planners, homeowners, and others rely on maps to identify areas at risk of being inundated. To identify areas at risk for inundation by a flood having a 1-percent annual probability, maps were created using topographic data and water-surface elevations resulting from hydrologic and hydraulic analyses. The hydrologic analysis for the Omaha Creek study area was performed using historical peak flows obtained from the U.S. Geological Survey streamflow gage (station number 06601000). Flood frequency and magnitude were estimated using the PEAKFQ Log-Pearson Type III analysis software. The U.S. Army Corps of Engineers' Hydrologic Engineering Center River Analysis System, version 3.1.3, software was used to simulate the water-surface elevation for flood events. The calibrated model was used to compute streamflow-gage stages and inundation elevations for the discharges corresponding to floods of selected probabilities. Results of the hydrologic and hydraulic analyses indicated that flood inundation elevations are substantially lower than from a previous study.

Integrated Urban Flood Analysis considering Optimal Operation of Flood Control Facilities in Urban Drainage Networks

NASA Astrophysics Data System (ADS)

Moon, Y. I.; Kim, M. S.; Choi, J. H.; Yuk, G. M.

2017-12-01

eavy rainfall has become a recent major cause of urban area flooding due to the climate change and urbanization. To prevent property damage along with casualties, a system which can alert and forecast urban flooding must be developed. Optimal performance of reducing flood damage can be expected of urban drainage facilities when operated in smaller rainfall events over extreme ones. Thus, the purpose of this study is to execute: A) flood forecasting system using runoff analysis based on short term rainfall; and B) flood warning system which operates based on the data from pump stations and rainwater storage in urban basins. In result of the analysis, it is shown that urban drainage facilities using short term rainfall forecasting data by radar will be more effective to reduce urban flood damage than using only the inflow data of the facility. Keywords: Heavy Rainfall, Urban Flood, Short-term Rainfall Forecasting, Optimal operating of urban drainage facilities. AcknowledgmentsThis research was supported by a grant (17AWMP-B066744-05) from Advanced Water Management Research Program (AWMP) funded by Ministry of Land, Infrastructure and Transport of Korean government.

Use of Remote Sensing Products for the SERVIR Project

NASA Technical Reports Server (NTRS)

Policelli, Frederick S.

2010-01-01

The United Nations University (UNU) estimates that floods presently impacts greater than 520 million people per year worldwide, resulting in up to 25,000 annual deaths, extensive homelessness, disaster-induced disease, crop and livestock damage, famine, and other serious harm. Meanwhile, aid agencies such as the International Federation of Red Cross and Red Crescent Societies (IFRC) are increasingly seeking better information concerning flood hazards in order to plan for and help mitigate the effects of damaging floods. There is fertile ground to continue development of better remote sensing and modeling techniques to help manage flood related disasters. Disaster management and humanitarian aid organizations need accurate and timely information for making decisions regarding deployment of relief teams and emergency supplies during major floods. Flood maps based on the use of satellite data have proven extremely valuable to such organizations for identifying the location, extent, and severity of these events. However, despite extraordinary efforts on the part of remote sensing data providers to rapidly deliver such maps, there is typically a delay of several days or even weeks from the on-set of flooding until such maps are available to the disaster management community. This paper summarizes efforts at NASA to address this problem through development of an integrated and automated process of a) flood forecasting b) flood detection, c) satellite data acquisition, d) rapid flood mapping and distribution, and e) validation of flood forecasting and detection products.

Hydrologic risk analysis in the Yangtze River basin through coupling Gaussian mixtures into copulas

NASA Astrophysics Data System (ADS)

Fan, Y. R.; Huang, W. W.; Huang, G. H.; Li, Y. P.; Huang, K.; Li, Z.

2016-02-01

In this study, a bivariate hydrologic risk framework is proposed through coupling Gaussian mixtures into copulas, leading to a coupled GMM-copula method. In the coupled GMM-Copula method, the marginal distributions of flood peak, volume and duration are quantified through Gaussian mixture models and the joint probability distributions of flood peak-volume, peak-duration and volume-duration are established through copulas. The bivariate hydrologic risk is then derived based on the joint return period of flood variable pairs. The proposed method is applied to the risk analysis for the Yichang station on the main stream of the Yangtze River, China. The results indicate that (i) the bivariate risk for flood peak-volume would keep constant for the flood volume less than 1.0 × 105 m3/s day, but present a significant decreasing trend for the flood volume larger than 1.7 × 105 m3/s day; and (ii) the bivariate risk for flood peak-duration would not change significantly for the flood duration less than 8 days, and then decrease significantly as duration value become larger. The probability density functions (pdfs) of the flood volume and duration conditional on flood peak can also be generated through the fitted copulas. The results indicate that the conditional pdfs of flood volume and duration follow bimodal distributions, with the occurrence frequency of the first vertex decreasing and the latter one increasing as the increase of flood peak. The obtained conclusions from the bivariate hydrologic analysis can provide decision support for flood control and mitigation.

Recent trends in the frequency and duration of global floods

NASA Astrophysics Data System (ADS)

Najibi, Nasser; Devineni, Naresh

2018-06-01

Frequency and duration of floods are analyzed using the global flood database of the Dartmouth Flood Observatory (DFO) to explore evidence of trends during 1985-2015 at global and latitudinal scales. Three classes of flood duration (i.e., short: 1-7, moderate: 8-20, and long: 21 days and above) are also considered for this analysis. The nonparametric Mann-Kendall trend analysis is used to evaluate three hypotheses addressing potential monotonic trends in the frequency of flood, moments of duration, and frequency of specific flood duration types. We also evaluated if trends could be related to large-scale atmospheric teleconnections using a generalized linear model framework. Results show that flood frequency and the tails of the flood duration (long duration) have increased at both the global and the latitudinal scales. In the tropics, floods have increased 4-fold since the 2000s. This increase is 2.5-fold in the north midlatitudes. However, much of the trend in frequency and duration of the floods can be placed within the long-term climate variability context since the Atlantic Multidecadal Oscillation, North Atlantic Oscillation, and Pacific Decadal Oscillation were the main atmospheric teleconnections explaining this trend. There is no monotonic trend in the frequency of short-duration floods across all the global and latitudinal scales. There is a significant increasing trend in the annual median of flood durations globally and each latitudinal belt, and this trend is not related to these teleconnections. While the DFO data come with a certain level of epistemic uncertainty due to imprecision in the estimation of floods, overall, the analysis provides insights for understanding the frequency and persistence in hydrologic extremes and how they relate to changes in the climate, organization of global and local dynamical systems, and country-scale socioeconomic factors.

Impact of Flooding on Land Use/ Land Cover Transformation in Wular Lake and its Environs, Kashmir Valley, India Using Geoinformatics

NASA Astrophysics Data System (ADS)

Ahmad, T.; Pandey, A. C.; Kumar, A.

2017-11-01

Wular lake, located at an elevation of 1520 m above sea level in Kashmir valley, India. In the present study, the immediate and long term impact of flood (2014) over the Wular lake environs was analyzed by using satellite images and employing supervised classification technique in GIS environment. The LULC classification was performed on the images of 25th August 2014 (pre flood) and 13th September 2015 (post flood) and was compared, which indicated marked decrease in terrestrial vegetation (23.7 %), agriculture (43.7 %) and water bodies (39.9 %). Overlaying analysis was performed with pre and post flood classified images with reference to the satellite image of 10th September 2014(during flood) which indicated total area inundated during flood was 88.77 km2. With the pre-flood situation, the aquatic vegetation of 34.06 km2, 13.89 km2 of agriculture land and terrestrial vegetation of 3.13 km2 was inundated. In the post flood situation, it was also came into focus that more than the half of the area under water bodies was converted into sand deposits (22.76 km2) due to anomalous increase in siltation. The overlay analysis on post flood classified image indicated that aquatic vegetation followed by agriculture and sand deposits lie within the flood inundated area. Further spatial analysis was performed within the flood inundated area (88.77 km2) with pre and post classified image to understand the situation before and after the flood and to calculate the changes. These land use-land cover transformations signifies the ill effect of flooding on the biodiversity of Wular Lake.

Effect of catchment properties and flood generation regime on copula selection for bivariate flood frequency analysis

NASA Astrophysics Data System (ADS)

Filipova, Valeriya; Lawrence, Deborah; Klempe, Harald

2018-02-01

Applying copula-based bivariate flood frequency analysis is advantageous because the results provide information on both the flood peak and volume. More data are, however, required for such an analysis, and it is often the case that only data series with a limited record length are available. To overcome this issue of limited record length, data regarding climatic and geomorphological properties can be used to complement statistical methods. In this paper, we present a study of 27 catchments located throughout Norway, in which we assess whether catchment properties, flood generation processes and flood regime have an effect on the correlation between flood peak and volume and, in turn, on the selection of copulas. To achieve this, the annual maximum flood events were first classified into events generated primarily by rainfall, snowmelt or a combination of these. The catchments were then classified into flood regime, depending on the predominant flood generation process producing the annual maximum flood events. A contingency table and Fisher's exact test were used to determine the factors that affect the selection of copulas in the study area. The results show that the two-parameter copulas BB1 and BB7 are more commonly selected in catchments with high steepness, high mean annual runoff and rainfall flood regime. These findings suggest that in these types of catchments, the dependence structure between flood peak and volume is more complex and cannot be modeled effectively using a one-parameter copula. The results illustrate that by relating copula types to flood regime and catchment properties, additional information can be supplied for selecting copulas in catchments with limited data.

Surface Water and Flood Extent Mapping, Monitoring, and Modeling Products and Services for the SERVIR Regions

NASA Technical Reports Server (NTRS)

Anderson, Eric

2016-01-01

SERVIR is a joint NASA - US Agency for International Development (USAID) project to improve environmental decision-making using Earth observations and geospatial technologies. A common need identified among SERVIR regions has been improved information for disaster risk reduction and in specific surface water and flood extent mapping, monitoring and forecasting. Of the 70 SERVIR products (active, complete, and in development), 4 are related to surface water and flood extent mapping, monitoring or forecasting. Visit http://www.servircatalog.net for more product details.

Applications of ASFCM(Assessment System of Flood Control Measurement) in Typhoon Committee Members

NASA Astrophysics Data System (ADS)

Kim, C.

2013-12-01

Due to extreme weather environment such as global warming and greenhouse effect, the risks of having flood damage has been increased with larger scale of flood damages. Therefore, it became necessary to consider modifying climate change, flood damage and its scale to the previous dimension measurement evaluation system. In this regard, it is needed to establish a comprehensive and integrated system to evaluate the most optimized measures for flood control through eliminating uncertainties of socio-economic impacts. Assessment System of Structural Flood Control Measures (ASFCM) was developed for determining investment priorities of the flood control measures and establishing the social infrastructure projects. ASFCM consists of three modules: 1) the initial setup and inputs module, 2) the flood and damage estimation module, and 3) the socio-economic analysis module. First, we have to construct the D/B for flood damage estimation, which is the initial and input data about the estimation unit, property, historical flood damages, and applied area's topographic & hydrological data. After that, it is important to classify local characteristic for constructing flood damage data. Five local characteristics (big city, medium size city, small city, farming area, and mountain area) are classified by criterion of application (population density). Next step is the floodplain simulation with HEC-RAS which is selected to simulate inundation. Through inputting the D/B and damage estimation, it is able to estimate the total damage (only direct damage) that is the amount of cost to recover the socio-economic activities back to the safe level before flood did occur. The last module suggests the economic analysis index (B/C ratio) with Multidimensional Flood Damage Analysis. Consequently, ASFCM suggests the reference index in constructing flood control measures and planning non-structural systems to reduce water-related damage. It is possible to encourage flood control planners and managers to consider and apply the socio-economic analysis results. ASFCM was applied in Republic of Korea, Thailand and Philippines to review efficiency and applicability. Figure 1. ASFCM Application(An-yang Stream, Republic of Korea)

26 CFR 1.821-4 - Tax on mutual insurance companies other than life insurance companies and other than fire, flood...

Code of Federal Regulations, 2011 CFR

2011-04-01

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26 CFR 1.821-4 - Tax on mutual insurance companies other than life insurance companies and other than fire, flood...

Code of Federal Regulations, 2012 CFR

2012-04-01

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26 CFR 1.821-4 - Tax on mutual insurance companies other than life insurance companies and other than fire, flood...

Code of Federal Regulations, 2013 CFR

2013-04-01

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26 CFR 1.821-4 - Tax on mutual insurance companies other than life insurance companies and other than fire, flood...

Code of Federal Regulations, 2010 CFR

2010-04-01

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26 CFR 1.821-4 - Tax on mutual insurance companies other than life insurance companies and other than fire, flood...

Code of Federal Regulations, 2014 CFR

2014-04-01

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Flood hazard assessment in areas prone to flash flooding

NASA Astrophysics Data System (ADS)

Kvočka, Davor; Falconer, Roger A.; Bray, Michaela

2016-04-01

Contemporary climate projections suggest that there will be an increase in the occurrence of high-intensity rainfall events in the future. These precipitation extremes are usually the main cause for the emergence of extreme flooding, such as flash flooding. Flash floods are among the most unpredictable, violent and fatal natural hazards in the world. Furthermore, it is expected that flash flooding will occur even more frequently in the future due to more frequent development of extreme weather events, which will greatly increase the danger to people caused by flash flooding. This being the case, there will be a need for high resolution flood hazard maps in areas susceptible to flash flooding. This study investigates what type of flood hazard assessment methods should be used for assessing the flood hazard to people caused by flash flooding. Two different types of flood hazard assessment methods were tested: (i) a widely used method based on an empirical analysis, and (ii) a new, physically based and experimentally calibrated method. Two flash flood events were considered herein, namely: the 2004 Boscastle flash flood and the 2007 Železniki flash flood. The results obtained in this study suggest that in the areas susceptible to extreme flooding, the flood hazard assessment should be conducted using methods based on a mechanics-based analysis. In comparison to standard flood hazard assessment methods, these physically based methods: (i) take into account all of the physical forces, which act on a human body in floodwater, (ii) successfully adapt to abrupt changes in the flow regime, which often occur for flash flood events, and (iii) rapidly assess a flood hazard index in a relatively short period of time.

Paleohydrology of flash floods in small desert watersheds in western Arizona

NASA Astrophysics Data System (ADS)

House, P. Kyle; Baker, Victor R.

2001-06-01

In this study, geological, historical, and meteorological data were combined to produce a regional chronology of flood magnitude and frequency in nine small basins (7-70 km2). The chronology spans more than 1000 years and demonstrates that detailed records of flood magnitude and frequency can be compiled in arid regions with little to no conventional hydrologic information. The recent (i.e., post-1950) flood history was evaluated by comparing a 50-year series of aerial photographs with precipitation data, ages of flood-transported beer cans, anthropogenic horizons in flood sediments, postbomb 14C dates on flotsam, and anecdotal accounts. Stratigraphic analysis of paleoflood deposits extended the regional flood record in time, and associated flood magnitudes were determined by incorporating relict high-water evidence into a hydraulic model. The results reveal a general consistency among the magnitudes of the largest floods in the historical and the paleoflood records and indicate that the magnitudes and relative frequencies of actual large floods are at variance with "100-year" flood magnitudes predicted by regional flood frequency models. This suggests that the predictive equations may not be appropriate for regulatory, management, or design purposes in the absence of additional, real data on flooding. Augmenting conventional approaches to regional flood magnitude and frequency analysis with real information derived from the alternative methods described here is a viable approach to improving assessments of regional flood characteristics in sparsely gaged desert areas.

Extreme flood event analysis in Indonesia based on rainfall intensity and recharge capacity

NASA Astrophysics Data System (ADS)

Narulita, Ida; Ningrum, Widya

2018-02-01

Indonesia is very vulnerable to flood disaster because it has high rainfall events throughout the year. Flood is categorized as the most important hazard disaster because it is causing social, economic and human losses. The purpose of this study is to analyze extreme flood event based on satellite rainfall dataset to understand the rainfall characteristic (rainfall intensity, rainfall pattern, etc.) that happened before flood disaster in the area for monsoonal, equatorial and local rainfall types. Recharge capacity will be analyzed using land cover and soil distribution. The data used in this study are CHIRPS rainfall satellite data on 0.05 ° spatial resolution and daily temporal resolution, and GSMap satellite rainfall dataset operated by JAXA on 1-hour temporal resolution and 0.1 ° spatial resolution, land use and soil distribution map for recharge capacity analysis. The rainfall characteristic before flooding, and recharge capacity analysis are expected to become the important information for flood mitigation in Indonesia.

Flood Hazard and Risk Analysis in Urban Area

NASA Astrophysics Data System (ADS)

Huang, Chen-Jia; Hsu, Ming-hsi; Teng, Wei-Hsien; Lin, Tsung-Hsien

2017-04-01

Typhoons always induce heavy rainfall during summer and autumn seasons in Taiwan. Extreme weather in recent years often causes severe flooding which result in serious losses of life and property. With the rapid industrial and commercial development, people care about not only the quality of life, but also the safety of life and property. So the impact of life and property due to disaster is the most serious problem concerned by the residents. For the mitigation of the disaster impact, the flood hazard and risk analysis play an important role for the disaster prevention and mitigation. In this study, the vulnerability of Kaohsiung city was evaluated by statistics of social development factor. The hazard factors of Kaohsiung city was calculated by simulated flood depth of six different return periods and four typhoon events which result in serious flooding in Kaohsiung city. The flood risk can be obtained by means of the flood hazard and social vulnerability. The analysis results provide authority to strengthen disaster preparedness and to set up more resources in high risk areas.

Model synthesis in frequency analysis of Missouri floods

USGS Publications Warehouse

Hauth, Leland D.

1974-01-01

Synthetic flood records for 43 small-stream sites aided in definition of techniques for estimating the magnitude and frequency of floods in Missouri. The long-term synthetic flood records were generated by use of a digital computer model of the rainfall-runoff process. A relatively short period of concurrent rainfall and runoff data observed at each of the 43 sites was used to calibrate the model, and rainfall records covering from 66 to 78 years for four Missouri sites and pan-evaporation data were used to generate the synthetic records. Flood magnitude and frequency characteristics of both the synthetic records and observed long-term flood records available for 109 large-stream sites were used in a multiple-regression analysis to define relations for estimating future flood characteristics at ungaged sites. That analysis indicated that drainage basin size and slope were the most useful estimating variables. It also indicated that a more complex regression model than the commonly used log-linear one was needed for the range of drainage basin sizes available in this study.

Fews-Risk: A step towards risk-based flood forecasting

NASA Astrophysics Data System (ADS)

Bachmann, Daniel; Eilander, Dirk; de Leeuw, Annemargreet; Diermanse, Ferdinand; Weerts, Albrecht; de Bruijn, Karin; Beckers, Joost; Boelee, Leonore; Brown, Emma; Hazlewood, Caroline

2015-04-01

Operational flood prediction and the assessment of flood risk are important components of flood management. Currently, the model-based prediction of discharge and/or water level in a river is common practice for operational flood forecasting. Based on the prediction of these values decisions about specific emergency measures are made within operational flood management. However, the information provided for decision support is restricted to pure hydrological or hydraulic aspects of a flood. Information about weak sections within the flood defences, flood prone areas and assets at risk in the protected areas are rarely used in a model-based flood forecasting system. This information is often available for strategic planning, but is not in an appropriate format for operational purposes. The idea of FEWS-Risk is the extension of existing flood forecasting systems with elements of strategic flood risk analysis, such as probabilistic failure analysis, two dimensional flood spreading simulation and the analysis of flood impacts and consequences. Thus, additional information is provided to the decision makers, such as: • Location, timing and probability of failure of defined sections of the flood defence line; • Flood spreading, extent and hydraulic values in the hinterland caused by an overflow or a breach flow • Impacts and consequences in case of flooding in the protected areas, such as injuries or casualties and/or damages to critical infrastructure or economy. In contrast with purely hydraulic-based operational information, these additional data focus upon decision support for answering crucial questions within an operational flood forecasting framework, such as: • Where should I reinforce my flood defence system? • What type of action can I take to mend a weak spot in my flood defences? • What are the consequences of a breach? • Which areas should I evacuate first? This presentation outlines the additional required workflows towards risk-based flood forecasting systems. In a cooperation between HR Wallingford and Deltares, the extended workflows are being integrated into the Delft-FEWS software system. Delft-FEWS provides modules for managing the data handling and forecasting process. Results of a pilot study that demonstrates the new tools are presented. The value of the newly generated information for decision support during a flood event is discussed.

Analysis of initial changes in the proteins of soybean root tip under flooding stress using gel-free and gel-based proteomic techniques.

PubMed

Yin, Xiaojian; Sakata, Katsumi; Nanjo, Yohei; Komatsu, Setsuko

2014-06-25

Flooding has a severe negative effect on soybean cultivation in the early stages of growth. To obtain a better understanding of the response mechanisms of soybean to flooding stress, initial changes in root tip proteins under flooding were analyzed using two proteomic techniques. Two-day-old soybeans were treated with flooding for 3, 6, 12, and 24h. The weight of soybeans increased during the first 3h of flooding, but root elongation was not observed. Using gel-based and gel-free proteomic techniques, 115 proteins were identified in root tips, of which 9 proteins were commonly detected by both methods. The 71 proteins identified by the gel-free proteomics were analyzed by a hierarchical clustering method based on induction levels during the flooding, and the proteins were divided into 5 clusters. Additional interaction analysis of the proteins revealed that ten proteins belonging to cluster I formed the center of a protein interaction network. mRNA expression analysis of these ten proteins showed that citrate lyase and heat shock protein 70 were down-regulated, whereas calreticulin was up-regulated in initial phase of flooding. These results suggest that flooding stress to soybean induces calcium-related signal transduction, which might play important roles in the early responses to flooding. Flooding has a severe negative effect on soybean cultivation, particularly in the early stages of growth. To better understand the response mechanisms of soybean to the early stages of flooding stress, two proteomic techniques were used. Two-day-old soybeans were treated without or with flooding for 3, 6, 12, and 24h. The fresh weight of soybeans increased during the first 3h of flooding stress, but the growth then slowed and no root elongation was observed. Using gel-based and gel-free proteomic techniques, 115 proteins were identified in root tips, of which 9 proteins were commonly detected by both methods. The 71 proteins identified by the gel-free proteomics were analyzed by a hierarchical clustering method based on induction levels during the flooding stress, and 5 protein clusters were recognized. Protein interaction analysis revealed that ten proteins belonging to cluster I formed the center of a protein interaction network. mRNA expression analysis of these ten proteins showed that citrate lyase and heat shock protein 70 were down-regulated in response to flooding stress, whereas calreticulin was up-regulated. These results suggest that flooding stress to soybean induces calcium-related signal transduction, which might play important roles in the early responses to flooding. Copyright © 2014 Elsevier B.V. All rights reserved.

The Use of Geospatial Technologies in Flood Hazard Mapping and Assessment: Case Study from River Evros

NASA Astrophysics Data System (ADS)

Mentzafou, Angeliki; Markogianni, Vasiliki; Dimitriou, Elias

2017-02-01

Many scientists link climate change to the increase of the extreme weather phenomena frequency, which combined with land use changes often lead to disasters with severe social and economic effects. Especially floods as a consequence of heavy rainfall can put vulnerable human and natural systems such as transboundary wetlands at risk. In order to meet the European Directive 2007/60/EC requirements for the development of flood risk management plans, the flood hazard map of Evros transboundary watershed was produced after a grid-based GIS modelling method that aggregates the main factors related to the development of floods: topography, land use, geology, slope, flow accumulation and rainfall intensity. The verification of this tool was achieved through the comparison between the produced hazard map and the inundation maps derived from the supervised classification of Landsat 5 and 7 satellite imageries of four flood events that took place at Evros delta proximity, a wetland of international importance. The comparison of the modelled output (high and very high flood hazard areas) with the extent of the inundated areas as mapped from the satellite data indicated the satisfactory performance of the model. Furthermore, the vulnerability of each land use against the flood events was examined. Geographically Weighted Regression has also been applied between the final flood hazard map and the major factors in order to ascertain their contribution to flood events. The results accredited the existence of a strong relationship between land uses and flood hazard indicating the flood susceptibility of the lowlands and agricultural land. A dynamic transboundary flood hazard management plan should be developed in order to meet the Flood Directive requirements for adequate and coordinated mitigation practices to reduce flood risk.

Flood risk assessment in a Spanish Mediterranean catchment

NASA Astrophysics Data System (ADS)

Salazar, S.; Francés, F.; García-Bartual, R.; Ortiz, E.; Múnera, J. C.; Vélez, J. J.

2009-04-01

This paper describes a multidisciplinary approach for the risk assessment and its application to analysing the effects of extreme flood events on the Mediterranean catchment called "Rambla del Poyo" in Valencia (Spain). This catchment located in the East coast of Spain has an area of 380 km2 and is clearly open to the Mediterranean Mesoscale Convective Storms. The climate is semiarid, and the flow regime is typically ephemeral, but with highly frequent flash floods, with peak flows in the order of 500 m3/s. Recently, in 2000 and 2002 the area was severe flooded. The flood prone area is located in the lower part of the basin, with an important concentration of different urban centers and industrial and commercial areas (including part of the Valencia International Airport). For this reason, the analysis of damages of residential, industrial and commercial urbanized areas is essential for the prevention of damages with a proper flood risk management. The approach is based on three main steps. The first step entails a detailed hydrological analysis (parameter estimation, calibration-validation and simulations) using a distributed rainfall-runoff model called TETIS. In the case study, on one hand, high temporal resolutions rain gauge data are scarce, because of this, in addition to a small number of historic events, 100 synthetic rainstorms were generated using the multidimensional stochastic model called RAINGEN, which adequately represents the main structural properties typical of intense convective storms, including occurrence of raincells in space and time and the generated intensities. An equivalent daily maximum precipitation Pd was estimated for each synthetic event, thus allowing a return period assignment using the known statistical distribution of Pd in the region. On the other hand, the initial soil moisture condition can have a strong influence in the runoff production, for this reason, long term daily simulation has been done in order to asses the probability distribution of the initial situation before the extreme flood events (dry and wet conditions). For all combinations of precipitation inputs and initial conditions, 200 hydrological simulations has been done in order to obtain the input hydrographs for the hydraulic model. Finally in this step, a frequency analysis to obtain the non-exceedence probability of the peak discharges has been developed using the annual maximum daily precipitation and the initial soil moisture condition with this expression: ž« FX (x) = FX |r (x|r).fR (r).dr -ž where: X= random variable of interest (peak discharge), R= annual maximum daily precipitation, fR(r)= probability density function of R, FX•r(x/r)= conditional density function of X given r obtained from simulations. The main objective of second step is flood hazard estimation, which, the hydraulic modelling has been developed using the coupled computing version of Sobek 1D/2D. In this task, the treatment of DEM calculation can be a key task depending on the scale of work. The introduction of buildings, walls, the opening of drainage works… improving the quality of results in areas with high anthropogenic influence; in our case has been made 6 simulations with 3 different resolutions, after all, the model has been done with a model one-dimensional (1D), logging throughout the stretch to two-dimensional (2D) grid with the parent of 30x30 metres, except for its passage through the urban, commercial and industrial land uses in the flood prone area where it connects with the child grid of 10x10 metres. Unfortunately, for reasons of computer time, the hydraulic model has not been run for the 200 available events. However, 20 events have been carefully select trying to cover the best probabilistic interest spectrum for this study (from two to one thousand years of return period). From the 20 selected flooding maps it has been developed a GIS computational tool for calculating a regression between the independent variable (maximum water depth) and the dependent variable return period transformed into natural logarithm. Using this methodology have been generated the hazard maps for the return periods of interest. Finally, the third step concerns to the flood risk, which was defined as probabilistic integral of the combination of flood hazard and land use vulnerability: ž« R = V (h).fH (h).dh 0 Where: R is the flood risk, V(h) is the land use vulnerability, h is the flood magnitude and fH(h) is its probability density function. The land use vulnerability is expressed in terms of stage-damage functions for urban, commercial and industrial land uses. Both, flood hazard and land use vulnerability are defined in terms of magnitude (water depth). This integral has been solved in discrete form using a GIS tools. The flood risk assessment by a resolution of 10 meters in size cell in the flood prone area of the "Rambla del Poyo" has been done. With this useful methodology, we believe that a complete flood risk analysis is needed in order to objectively compare different future scenarios that can affect either the flood hazard and/or the vulnerability in the flood prone area.

Uncertainty in flood damage estimates and its potential effect on investment decisions

NASA Astrophysics Data System (ADS)

Wagenaar, Dennis; de Bruijn, Karin; Bouwer, Laurens; de Moel, Hans

2015-04-01

This paper addresses the large differences that are found between damage estimates of different flood damage models. It explains how implicit assumptions in flood damage models can lead to large uncertainties in flood damage estimates. This explanation is used to quantify this uncertainty with a Monte Carlo Analysis. This Monte Carlo analysis uses a damage function library with 272 functions from 7 different flood damage models. This results in uncertainties in the order of magnitude of a factor 2 to 5. This uncertainty is typically larger for small water depths and for smaller flood events. The implications of the uncertainty in damage estimates for flood risk management are illustrated by a case study in which the economic optimal investment strategy for a dike segment in the Netherlands is determined. The case study shows that the uncertainty in flood damage estimates can lead to significant over- or under-investments.

Uncertainty in flood damage estimates and its potential effect on investment decisions

NASA Astrophysics Data System (ADS)

Wagenaar, D. J.; de Bruijn, K. M.; Bouwer, L. M.; De Moel, H.

2015-01-01

This paper addresses the large differences that are found between damage estimates of different flood damage models. It explains how implicit assumptions in flood damage models can lead to large uncertainties in flood damage estimates. This explanation is used to quantify this uncertainty with a Monte Carlo Analysis. As input the Monte Carlo analysis uses a damage function library with 272 functions from 7 different flood damage models. This results in uncertainties in the order of magnitude of a factor 2 to 5. The resulting uncertainty is typically larger for small water depths and for smaller flood events. The implications of the uncertainty in damage estimates for flood risk management are illustrated by a case study in which the economic optimal investment strategy for a dike segment in the Netherlands is determined. The case study shows that the uncertainty in flood damage estimates can lead to significant over- or under-investments.

Recent changes in flood damage in the United States from observations and ACME model

NASA Astrophysics Data System (ADS)

Leng, G.; Leung, L. R.

2017-12-01

Despite efforts to mitigate flood hazards in flood-prone areas, survey- and report-based flood databases show that flood damage has increased and emerged as one of the most costly disaster in the United States since the 1990s. Understanding the mechanism driving the changes in flood damage is therefore critical for reducing flood risk. In this study, we first conduct a comprehensive analysis of the changing characteristics of flood damage at local, state and country level. Results show a significant increasing trend in the number of flood hazards, causing economic losses of up to $7 billion per year. The ratio of flood events that caused tangible economical cost to the total flood events has exhibited a non-significant increasing trend before 2007 followed by a significant decrease, indicating a changing vulnerability to floods. Analysis also reveals distinct spatial and temporal patterns in the threshold intensity of flood hazards with tangible economical cost. To understand the mechanism behind the increasing flood damage, we develop a flood damage economic model coupled with the integrated hydrological modeling system of ACME that features a river routing model with an inundation parameterization and a water use and regulation model. The model is evaluated over the country against historical records. Several numerical experiments are then designed to explore the mechanisms behind the recent changes in flood damage from the perspective of flood hazard, exposure and vulnerability, which constitute flood damage. The role of human activities such as reservoir operations and water use in modifying regional floods are also explored using the new tool, with the goal of improving understanding and modeling of vulnerability to flood hazards.

Uncertainty in flood damage estimates and its potential effect on investment decisions

NASA Astrophysics Data System (ADS)

Wagenaar, D. J.; de Bruijn, K. M.; Bouwer, L. M.; de Moel, H.

2016-01-01

This paper addresses the large differences that are found between damage estimates of different flood damage models. It explains how implicit assumptions in flood damage functions and maximum damages can have large effects on flood damage estimates. This explanation is then used to quantify the uncertainty in the damage estimates with a Monte Carlo analysis. The Monte Carlo analysis uses a damage function library with 272 functions from seven different flood damage models. The paper shows that the resulting uncertainties in estimated damages are in the order of magnitude of a factor of 2 to 5. The uncertainty is typically larger for flood events with small water depths and for smaller flood events. The implications of the uncertainty in damage estimates for flood risk management are illustrated by a case study in which the economic optimal investment strategy for a dike segment in the Netherlands is determined. The case study shows that the uncertainty in flood damage estimates can lead to significant over- or under-investments.

Flood Risk and Probabilistic Benefit Assessment to Support Management of Flood-Prone Lands: Evidence From Candaba Floodplains, Philippines

NASA Astrophysics Data System (ADS)

Juarez, A. M.; Kibler, K. M.; Sayama, T.; Ohara, M.

2016-12-01

Flood management decision-making is often supported by risk assessment, which may overlook the role of coping capacity and the potential benefits derived from direct use of flood-prone land. Alternatively, risk-benefit analysis can support floodplain management to yield maximum socio-ecological benefits for the minimum flood risk. We evaluate flood risk-probabilistic benefit tradeoffs of livelihood practices compatible with direct human use of flood-prone land (agriculture/wild fisheries) and nature conservation (wild fisheries only) in Candaba, Philippines. Located north-west to Metro Manila, Candaba area is a multi-functional landscape that provides a temporally-variable mix of possible land uses, benefits and ecosystem services of local and regional value. To characterize inundation from 1.3- to 100-year recurrence intervals we couple frequency analysis with rainfall-runoff-inundation modelling and remotely-sensed data. By combining simulated probabilistic floods with both damage and benefit functions (e.g. fish capture and rice yield with flood intensity) we estimate potential damages and benefits over varying probabilistic flood hazards. We find that although direct human uses of flood-prone land are associated with damages, for all the investigated magnitudes of flood events with different frequencies, the probabilistic benefits ( 91 million) exceed risks by a large margin ( 33 million). Even considering risk, probabilistic livelihood benefits of direct human uses far exceed benefits provided by scenarios that exclude direct "risky" human uses (difference of 85 million). In addition, we find that individual coping strategies, such as adapting crop planting periods to the flood pulse or fishing rather than cultivating rice in the wet season, minimize flood losses ( 6 million) while allowing for valuable livelihood benefits ($ 125 million) in flood-prone land. Analysis of societal benefits and local capacities to cope with regular floods demonstrate the relevance of accounting for the full range of flood events and their relation to both potential damages and benefits in risk assessments. Management measures may thus be designed to reflect local contexts and support benefits of natural hydrologic processes, while minimizing flood damage.

Germany wide seasonal flood risk analysis for agricultural crops

NASA Astrophysics Data System (ADS)

Klaus, Stefan; Kreibich, Heidi; Kuhlmann, Bernd; Merz, Bruno; Schröter, Kai

2016-04-01

In recent years, large-scale flood risk analysis and mapping has gained attention. Regional to national risk assessments are needed, for example, for national risk policy developments, for large-scale disaster management planning and in the (re-)insurance industry. Despite increasing requests for comprehensive risk assessments some sectors have not received much scientific attention, one of these is the agricultural sector. In contrast to other sectors, agricultural crop losses depend strongly on the season. Also flood probability shows seasonal variation. Thus, the temporal superposition of high flood susceptibility of crops and high flood probability plays an important role for agricultural flood risk. To investigate this interrelation and provide a large-scale overview of agricultural flood risk in Germany, an agricultural crop loss model is used for crop susceptibility analyses and Germany wide seasonal flood-frequency analyses are undertaken to derive seasonal flood patterns. As a result, a Germany wide map of agricultural flood risk is shown as well as the crop type most at risk in a specific region. The risk maps may provide guidance for federal state-wide coordinated designation of retention areas.

Fault tree analysis for urban flooding.

PubMed

ten Veldhuis, J A E; Clemens, F H L R; van Gelder, P H A J M

2009-01-01

Traditional methods to evaluate flood risk generally focus on heavy storm events as the principal cause of flooding. Conversely, fault tree analysis is a technique that aims at modelling all potential causes of flooding. It quantifies both overall flood probability and relative contributions of individual causes of flooding. This paper presents a fault model for urban flooding and an application to the case of Haarlem, a city of 147,000 inhabitants. Data from a complaint register, rainfall gauges and hydrodynamic model calculations are used to quantify probabilities of basic events in the fault tree. This results in a flood probability of 0.78/week for Haarlem. It is shown that gully pot blockages contribute to 79% of flood incidents, whereas storm events contribute only 5%. This implies that for this case more efficient gully pot cleaning is a more effective strategy to reduce flood probability than enlarging drainage system capacity. Whether this is also the most cost-effective strategy can only be decided after risk assessment has been complemented with a quantification of consequences of both types of events. To do this will be the next step in this study.

Prehistoric floods on the Tennessee River—Assessing the use of stratigraphic records of past floods for improved flood-frequency analysis

USGS Publications Warehouse

Harden, Tessa M.; O'Connor, Jim E.

2017-06-14

Stratigraphic analysis, coupled with geochronologic techniques, indicates that a rich history of large Tennessee River floods is preserved in the Tennessee River Gorge area. Deposits of flood sediment from the 1867 peak discharge of record (460,000 cubic feet per second at Chattanooga, Tennessee) are preserved at many locations throughout the study area at sites with flood-sediment accumulation. Small exposures at two boulder overhangs reveal evidence of three to four other floods similar in size, or larger, than the 1867 flood in the last 3,000 years—one possibly as much or more than 50 percent larger. Records of floods also are preserved in stratigraphic sections at the mouth of the gorge at Williams Island and near Eaves Ferry, about 70 river miles upstream of the gorge. These stratigraphic records may extend as far back as about 9,000 years ago, giving a long history of Tennessee River floods. Although more evidence is needed to confirm these findings, a more in-depth comprehensive paleoflood study is feasible for the Tennessee River.

Rapid flood loss estimation for large scale floods in Germany

NASA Astrophysics Data System (ADS)

Schröter, Kai; Kreibich, Heidi; Merz, Bruno

2013-04-01

Rapid evaluations of flood events are needed for efficient responses both in emergency management and financial appraisal. Beyond that, closely monitoring and documenting the formation and development of flood events and their impacts allows for an improved understanding and in depth analyses of the interplay between meteorological, hydrological, hydraulic and societal causes leading to flood damage. This contribution focuses on the development of a methodology for the rapid assessment of flood events. In the first place, the focus is on the prediction of damage to residential buildings caused by large scale floods in Germany. For this purpose an operational flood event analysis system is developed. This system has basic spatial thematic data available and supports data capturing about the current flood situation. This includes the retrieval of online gauge data and the integration of remote sensing data. Further, it provides functionalities to evaluate the current flood situation, to assess the hazard extent and intensity and to estimate the current flood impact using the flood loss estimation model FLEMOps+r. The operation of the flood event analysis system will be demonstrated for the past flood event from January 2011 with a focus on the Elbe/Saale region. On this grounds, further requirements and potential for improving the information basis as for instance by including hydrological and /or hydraulic model results as well as information from social sensors will be discussed.

Assessment of big floods in the Eastern Black Sea Basin of Turkey.

PubMed

Yüksek, Ömer; Kankal, Murat; Üçüncü, Osman

2013-01-01

In this study, general knowledge and some details of the floods in Eastern Black Sea Basin of Turkey are presented. Brief hydro-meteorological analysis of selected nine floods and detailed analysis of the greatest flood are given. In the studied area, 51 big floods have taken place between 1955-2005 years, causing 258 deaths and nearly US $500,000,000 of damage. Most of the floods have occurred in June, July and August. It is concluded that especially for the rainstorms that have caused significantly damages, the return periods of the rainfall heights and resultant flood discharges have gone up to 250 and 500 years, respectively. A general agreement is observed between the return periods of rains and resultant floods. It is concluded that there has been no significant climate change to cause increases in flood harms. The most important human factors to increase the damage are determined as wrong and illegal land use, deforestation and wrong urbanization and settlement, psychological and technical factors. Some structural and non-structural measures to mitigate flood damages are also included in the paper. Structural measures include dykes and flood levees. Main non-structural measures include flood warning system, modification of land use, watershed management and improvement, flood insurance, organization of flood management studies, coordination between related institutions and education of the people and informing of the stakeholders.

Use of map analysis to elucidate flooding in an Australian Riparian River Red Gum Forest

NASA Astrophysics Data System (ADS)

Bren, L. J.; O'Neill, I. C.; Gibbs, N. L.

1988-07-01

Red gum (Eucalyptus camaldulensis) forests occur on extensive floodplains along the river Murray in Australia. This type of forest is unusual because of its high quality in a semiarid area, the absence of woody species other than red gum, and its survival on a deep, intractable, swelling clay soil of depths exceeding 20 m. This soil probably acts as an aquiclude. The forests require flooding to thrive and regenerate. For many years there has been speculation that irrigation regulation of the river was reducing forest flooding. A grid cell analysis of flood maps of areas flooded over a period of 22 years showed that vegetation communities and forest site quality were statistically related to the flood frequencies of sites. The percentage of forest inundated was dependent on the peak daily flow during the period of inundation. A historical analysis of the estimated percentage of forest inundated showed a substantial influence of river regulation on both timing and extent of inundation. Estimates of historical floodings showed that the environment is one that changes rapidly from wetland to dry land. Although not without limitations, the analysis produced information not available from other sources.

GIS and remote sensing techniques for the assessment of land use changes impact on flood hydrology: the case study of Yialias Basin in Cyprus

NASA Astrophysics Data System (ADS)

Alexakis, D. D.; Gryllakis, M. G.; Koutroulis, A. G.; Agapiou, A.; Themistocleous, K.; Tsanis, I. K.; Michaelides, S.; Pashiardis, S.; Demetriou, C.; Aristeidou, K.; Retalis, A.; Tymvios, F.; Hadjimitsis, D. G.

2013-09-01

Flooding is one of the most common natural disasters worldwide, leading to economic losses and loss of human lives. This paper highlights the hydrological effects of multi-temporal land use changes in flood hazard within the Yialias catchment area, located in central Cyprus. Calibrated hydrological and hydraulic models were used to describe the hydrological processes and internal basin dynamics of the three major sub-basins, in order to study the diachronic effects of land use changes. For the implementation of the hydrological model, land use, soil and hydrometeorological data were incorporated. The climatic and stream flow data were derived from rain and flow gauge stations located in the wider area of the watershed basin. In addition, the land use and soil data were extracted after the application of object oriented nearest neighbor algorithms of ASTER satellite images. Subsequently, the CA-Markov chain analysis was implemented to predict the 2020 Land use/Land cover (LULC) map and incorporate it to the hydrological impact assessment. The results denoted the increase of runoff in the catchment area due to the recorded extensive urban sprawl phenomenon of the last decade.

GIS and remote sensing techniques for the assessment of land use change impact on flood hydrology: the case study of Yialias basin in Cyprus

NASA Astrophysics Data System (ADS)

Alexakis, D. D.; Grillakis, M. G.; Koutroulis, A. G.; Agapiou, A.; Themistocleous, K.; Tsanis, I. K.; Michaelides, S.; Pashiardis, S.; Demetriou, C.; Aristeidou, K.; Retalis, A.; Tymvios, F.; Hadjimitsis, D. G.

2014-02-01

Floods are one of the most common natural disasters worldwide, leading to economic losses and loss of human lives. This paper highlights the hydrological effects of multi-temporal land use changes in flood hazard within the Yialias catchment area, located in central Cyprus. A calibrated hydrological model was firstly developed to describe the hydrological processes and internal basin dynamics of the three major subbasins, in order to study the diachronic effects of land use changes. For the implementation of the hydrological model, land use, soil and hydrometeorological data were incorporated. The climatic and stream flow data were derived from rain and flow gauge stations located in the wider area of the watershed basin. In addition, the land use and soil data were extracted after the application of object-oriented nearest neighbor algorithms of ASTER satellite images. Subsequently, the cellular automata (CA)-Markov chain analysis was implemented to predict the 2020 land use/land cover (LULC) map and incorporate it to the hydrological impact assessment. The results denoted the increase of runoff in the catchment area due to the recorded extensive urban sprawl phenomenon of the last decade.

The morphodynamics and internal structure of intertidal fine-gravel dunes: Hills Flats, Severn Estuary, UK

NASA Astrophysics Data System (ADS)

Carling, P. A.; Radecki-Pawlik, A.; Williams, J. J.; Rumble, B.; Meshkova, L.; Bell, P.; Breakspear, R.

2006-01-01

In the macrotidal Severn estuary, UK, the dynamics of intertidal fine-gravel dunes were investigated. These dunes are migrating across a bedrock platform. Systematic observations were made of hydraulic climate, geometry, migration rates and internal sedimentary structures of the dunes. During spring tides, the ebb flow is dominant, dunes grow in height and have ebb orientated geometry with bedrock floors in the troughs. During neap tides, a weak flood flow may dominate. Dunes then are flood orientated or symmetrical. Neap dune heights decrease and the eroded sediment is stored in the dune troughs where the bedrock becomes blanketed by muddy gravel. During spring tides, instantaneous bed shear stresses reach 8 N m - 2 , sufficient to disrupt a 9 mm-gravel armour layer. However, a sustained bed shear stress of 4 N m - 2 is required to initiate dune migration at which time the critical depth-mean velocity is 1 m s - 1 . Ebb and flood inequalities in the bed shear stress explain the changes in dune asymmetry and internal structures. During flood tides, the crests of the dunes reverse such that very mobile sedimentary 'caps' overlie a more stable dune 'core'. Because ebb tides dominate, internal structures of the caps often are characterised by ebb orientated steep open-work foresets developed by strong tidal currents and some lower angle crossbeds deposited as weaker currents degrade foresets. The foresets forming the caps may be grouped into cosets (tidal bundles) and are separated from mud-infused cores of crossbeds that lie below, by reactivation and erosion surfaces blanketed by discontinuous mud drapes. The cores often exhibit distinctive muddy toe sets that define the spacing of tidal cosets.

Flood maps in Europe - methods, availability and use

NASA Astrophysics Data System (ADS)

de Moel, H.; van Alphen, J.; Aerts, J. C. J. H.

2009-03-01

To support the transition from traditional flood defence strategies to a flood risk management approach at the basin scale in Europe, the EU has adopted a new Directive (2007/60/EC) at the end of 2007. One of the major tasks which member states must carry out in order to comply with this Directive is to map flood hazards and risks in their territory, which will form the basis of future flood risk management plans. This paper gives an overview of existing flood mapping practices in 29 countries in Europe and shows what maps are already available and how such maps are used. Roughly half of the countries considered have maps covering as good as their entire territory, and another third have maps covering significant parts of their territory. Only five countries have very limited or no flood maps available yet. Of the different flood maps distinguished, it appears that flood extent maps are the most commonly produced floods maps (in 23 countries), but flood depth maps are also regularly created (in seven countries). Very few countries have developed flood risk maps that include information on the consequences of flooding. The available flood maps are mostly developed by governmental organizations and primarily used for emergency planning, spatial planning, and awareness raising. In spatial planning, flood zones delimited on flood maps mainly serve as guidelines and are not binding. Even in the few countries (e.g. France, Poland) where there is a legal basis to regulate floodplain developments using flood zones, practical problems are often faced which reduce the mitigating effect of such binding legislation. Flood maps, also mainly extent maps, are also created by the insurance industry in Europe and used to determine insurability, differentiate premiums, or to assess long-term financial solvency. Finally, flood maps are also produced by international river commissions. With respect to the EU Flood Directive, many countries already have a good starting point to map their flood hazards. A flood risk based map that includes consequences, however, has yet to be developed by most countries.

Integrating Household Risk Mitigation Behavior in Flood Risk Analysis: An Agent-Based Model Approach.

PubMed

Haer, Toon; Botzen, W J Wouter; de Moel, Hans; Aerts, Jeroen C J H

2017-10-01

Recent studies showed that climate change and socioeconomic trends are expected to increase flood risks in many regions. However, in these studies, human behavior is commonly assumed to be constant, which neglects interaction and feedback loops between human and environmental systems. This neglect of human adaptation leads to a misrepresentation of flood risk. This article presents an agent-based model that incorporates human decision making in flood risk analysis. In particular, household investments in loss-reducing measures are examined under three economic decision models: (1) expected utility theory, which is the traditional economic model of rational agents; (2) prospect theory, which takes account of bounded rationality; and (3) a prospect theory model, which accounts for changing risk perceptions and social interactions through a process of Bayesian updating. We show that neglecting human behavior in flood risk assessment studies can result in a considerable misestimation of future flood risk, which is in our case study an overestimation of a factor two. Furthermore, we show how behavior models can support flood risk analysis under different behavioral assumptions, illustrating the need to include the dynamic adaptive human behavior of, for instance, households, insurers, and governments. The method presented here provides a solid basis for exploring human behavior and the resulting flood risk with respect to low-probability/high-impact risks. © 2016 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

Using risk-based analysis and geographic information systems to assess flooding problems in an urban watershed in Rhode Island.

PubMed

Hardmeyer, Kent; Spencer, Michael A

2007-04-01

This article provides an overview of the use of risk-based analysis (RBA) in flood damage assessment, and it illustrates the use of Geographic Information Systems (GIS) in identifying flood-prone areas, which can aid in flood-mitigation planning assistance. We use RBA to calculate expected annual flood damages in an urban watershed in the state of Rhode Island, USA. The method accounts for the uncertainty in the three primary relationships used in computing flood damage: (1) the probability that a given flood will produce a given amount of floodwater, (2) the probability that a given amount of floodwater will reach a certain stage or height, and (3) the probability that a certain stage of floodwater will produce a given amount of damage. A greater than 50% increase in expected annual flood damage is estimated for the future if previous development patterns continue and flood-mitigation measures are not taken. GIS is then used to create a map that shows where and how often floods might occur in the future, which can help (1) identify priority areas for flood-mitigation planning assistance and (2) disseminate information to public officials and other decision-makers.

How do we best estimate fluvial flood risk in urban environments? : The case of the city of Eilenburg, Germany

NASA Astrophysics Data System (ADS)

Longo, Elisa; Tito Aronica, Giuseppe; Di Baldassarre, Giuliano; Mukolwe, Micah

2015-04-01

Flooding is one of the most impactful natural hazards. In particular, by looking at the data of damages from natural hazards in Europe collected in the International Disaster Database (EM-DAT) one can see a significant increase over the past four decades of both frequency of floods and associated economic damages. Similarly, dramatic trends are also found by analyzing other types of flood losses, such as the number of people affected by floods, homeless, injured or killed. To deal with the aforementioned increase of flood risk, more and more efforts are being made to promote integrated flood risk management, for instance, at the end of 2007, the European Community (EC) issued the Flood Directive (F.D.) 2007/60/EC. One of the major innovations was that the F.D. 2007/60/C requires Member State to carry out risk maps and then take appropriate measures to reduce the evaluated risk. The main goal of this research was to estimate flood damaging using a computer code based on a recently developed method (KULTURisk, www.kulturisk.eu) and to compare the estimated damage with the observed one. The study area was the municipality of Eilenburg, which in 2002 was subjected to a destructive flood event. Were produced flood damage maps with new procedures (e.g. KULTURisk) and compared the estimates with observed data. This study showed the possibility to extend the lesson learned with the Eilenburg case study in other similar contexts. The outcomes of this test provided interesting insights about the flood risk mapping, which are expected to contribute to raise awareness to the flooding issues,to plan (structural and/or non-structural) measures of flood risk reduction and to support better land-use and urban planning.

Estimating Water Levels with Google Earth Engine

NASA Astrophysics Data System (ADS)

Lucero, E.; Russo, T. A.; Zentner, M.; May, J.; Nguy-Robertson, A. L.

2016-12-01

Reservoirs serve multiple functions and are vital for storage, electricity generation, and flood control. For many areas, traditional ground-based reservoir measurements may not be available or data dissemination may be problematic. Consistent monitoring of reservoir levels in data-poor areas can be achieved through remote sensing, providing information to researchers and the international community. Estimates of trends and relative reservoir volume can be used to identify water supply vulnerability, anticipate low power generation, and predict flood risk. Image processing with automated cloud computing provides opportunities to study multiple geographic areas in near real-time. We demonstrate the prediction capability of a cloud environment for identifying water trends at reservoirs in the US, and then apply the method to data-poor areas in North Korea, Iran, Azerbaijan, Zambia, and India. The Google Earth Engine cloud platform hosts remote sensing data and can be used to automate reservoir level estimation with multispectral imagery. We combine automated cloud-based analysis from Landsat image classification to identify reservoir surface area trends and radar altimetry to identify reservoir level trends. The study estimates water level trends using three years of data from four domestic reservoirs to validate the remote sensing method, and five foreign reservoirs to demonstrate the method application. We report correlations between ground-based reservoir level measurements in the US and our remote sensing methods, and correlations between the cloud analysis and altimetry data for reservoirs in data-poor areas. The availability of regular satellite imagery and an automated, near real-time application method provides the necessary datasets for further temporal analysis, reservoir modeling, and flood forecasting. All statements of fact, analysis, or opinion are those of the author and do not reflect the official policy or position of the Department of Defense or any of its components or the U.S. Government

Citizen Science to Support Community-based Flood Early Warning and Resilience Building

NASA Astrophysics Data System (ADS)

Paul, J. D.; Buytaert, W.; Allen, S.; Ballesteros-Cánovas, J. A.; Bhusal, J.; Cieslik, K.; Clark, J.; Dewulf, A.; Dhital, M. R.; Hannah, D. M.; Liu, W.; Nayaval, J. L.; Schiller, A.; Smith, P. J.; Stoffel, M.; Supper, R.

2017-12-01

In Disaster Risk Management, an emerging shift has been noted from broad-scale, top-down assessments towards more participatory, community-based, bottom-up approaches. Combined with technologies for robust and low-cost sensor networks, a citizen science approach has recently emerged as a promising direction in the provision of extensive, real-time information for flood early warning systems. Here we present the framework and initial results of a major new international project, Landslide EVO, aimed at increasing local resilience against hydrologically induced disasters in western Nepal by exploiting participatory approaches to knowledge generation and risk governance. We identify three major technological developments that strongly support our approach to flood early warning and resilience building in Nepal. First, distributed sensor networks, participatory monitoring, and citizen science hold great promise in complementing official monitoring networks and remote sensing by generating site-specific information with local buy-in, especially in data-scarce regions. Secondly, the emergence of open source, cloud-based risk analysis platforms supports the construction of a modular, distributed, and potentially decentralised data processing workflow. Finally, linking data analysis platforms to social computer networks and ICT (e.g. mobile phones, tablets) allows tailored interfaces and people-centred decision- and policy-support systems to be built. Our proposition is that maximum impact is created if end-users are involved not only in data collection, but also over the entire project life-cycle, including the analysis and provision of results. In this context, citizen science complements more traditional knowledge generation practices, and also enhances multi-directional information provision, risk management, early-warning systems and local resilience building.

An Agent-Based Model of Evolving Community Flood Risk.

PubMed

Tonn, Gina L; Guikema, Seth D

2018-06-01

Although individual behavior plays a major role in community flood risk, traditional flood risk models generally do not capture information on how community policies and individual decisions impact the evolution of flood risk over time. The purpose of this study is to improve the understanding of the temporal aspects of flood risk through a combined analysis of the behavioral, engineering, and physical hazard aspects of flood risk. Additionally, the study aims to develop a new modeling approach for integrating behavior, policy, flood hazards, and engineering interventions. An agent-based model (ABM) is used to analyze the influence of flood protection measures, individual behavior, and the occurrence of floods and near-miss flood events on community flood risk. The ABM focuses on the following decisions and behaviors: dissemination of flood management information, installation of community flood protection, elevation of household mechanical equipment, and elevation of homes. The approach is place based, with a case study area in Fargo, North Dakota, but is focused on generalizable insights. Generally, community mitigation results in reduced future damage, and individual action, including mitigation and movement into and out of high-risk areas, can have a significant influence on community flood risk. The results of this study provide useful insights into the interplay between individual and community actions and how it affects the evolution of flood risk. This study lends insight into priorities for future work, including the development of more in-depth behavioral and decision rules at the individual and community level. © 2017 Society for Risk Analysis.

Supply and demand analysis for flood insurance by using logistic regression model: case study at Citarum watershed in South Bandung, West Java, Indonesia

NASA Astrophysics Data System (ADS)

Sidi, P.; Mamat, M.; Sukono; Supian, S.

2017-01-01

Floods have always occurred in the Citarum river basin. The adverse effects caused by floods can cover all their property, including the destruction of houses. The impact due to damage to residential buildings is usually not small. Indeed, each of flooding, the government and several social organizations providing funds to repair the building. But the donations are given very limited, so it cannot cover the entire cost of repair was necessary. The presence of insurance products for property damage caused by the floods is considered very important. However, if its presence is also considered necessary by the public or not? In this paper, the factors that affect the supply and demand of insurance product for damaged building due to floods are analyzed. The method used in this analysis is the ordinal logistic regression. Based on the analysis that the factors that affect the supply and demand of insurance product for damaged building due to floods, it is included: age, economic circumstances, family situations, insurance motivations, and lifestyle. Simultaneously that the factors affecting supply and demand of insurance product for damaged building due to floods mounted to 65.7%.

Flood return level analysis of Peaks over Threshold series under changing climate

NASA Astrophysics Data System (ADS)

Li, L.; Xiong, L.; Hu, T.; Xu, C. Y.; Guo, S.

2016-12-01

Obtaining insights into future flood estimation is of great significance for water planning and management. Traditional flood return level analysis with the stationarity assumption has been challenged by changing environments. A method that takes into consideration the nonstationarity context has been extended to derive flood return levels for Peaks over Threshold (POT) series. With application to POT series, a Poisson distribution is normally assumed to describe the arrival rate of exceedance events, but this distribution assumption has at times been reported as invalid. The Negative Binomial (NB) distribution is therefore proposed as an alternative to the Poisson distribution assumption. Flood return levels were extrapolated in nonstationarity context for the POT series of the Weihe basin, China under future climate scenarios. The results show that the flood return levels estimated under nonstationarity can be different with an assumption of Poisson and NB distribution, respectively. The difference is found to be related to the threshold value of POT series. The study indicates the importance of distribution selection in flood return level analysis under nonstationarity and provides a reference on the impact of climate change on flood estimation in the Weihe basin for the future.

Combining information from multiple flood projections in a hierarchical Bayesian framework

NASA Astrophysics Data System (ADS)

Le Vine, Nataliya

2016-04-01

This study demonstrates, in the context of flood frequency analysis, the potential of a recently proposed hierarchical Bayesian approach to combine information from multiple models. The approach explicitly accommodates shared multimodel discrepancy as well as the probabilistic nature of the flood estimates, and treats the available models as a sample from a hypothetical complete (but unobserved) set of models. The methodology is applied to flood estimates from multiple hydrological projections (the Future Flows Hydrology data set) for 135 catchments in the UK. The advantages of the approach are shown to be: (1) to ensure adequate "baseline" with which to compare future changes; (2) to reduce flood estimate uncertainty; (3) to maximize use of statistical information in circumstances where multiple weak predictions individually lack power, but collectively provide meaningful information; (4) to diminish the importance of model consistency when model biases are large; and (5) to explicitly consider the influence of the (model performance) stationarity assumption. Moreover, the analysis indicates that reducing shared model discrepancy is the key to further reduction of uncertainty in the flood frequency analysis. The findings are of value regarding how conclusions about changing exposure to flooding are drawn, and to flood frequency change attribution studies.

Transcriptomic analysis reveals the flooding tolerant mechanism in flooding tolerant line and abscisic acid treated soybean.

PubMed

Yin, Xiaojian; Hiraga, Susumu; Hajika, Makita; Nishimura, Minoru; Komatsu, Setsuko

2017-03-01

Soybean is highly sensitive to flooding stress and exhibits markedly reduced plant growth and grain yield under flooding conditions. To explore the mechanisms underlying initial flooding tolerance in soybean, RNA sequencing-based transcriptomic analysis was performed using a flooding-tolerant line and ABA-treated soybean. A total of 31 genes included 12 genes that exhibited similar temporal patterns were commonly changed in these plant groups in response to flooding and they were mainly involved in RNA regulation and protein metabolism. The mRNA expression of matrix metalloproteinase, glucose-6-phosphate isomerase, ATPase family AAA domain-containing protein 1, and cytochrome P450 77A1 was up-regulated in wild-type soybean under flooding conditions; however, no changes were detected in the flooding-tolerant line or ABA-treated soybean. The mRNA expression of cytochrome P450 77A1 was specifically up-regulated in root tips by flooding stress, but returned to the level found in control plants following treatment with the P450 inhibitor uniconazole. The survival ratio and root fresh weight of plants were markedly improved by 3-h uniconazole treatment under flooding stress. Taken together, these results suggest that cytochrome P450 77A1 is suppressed by uniconazole treatment and that this inhibition may enhance soybean tolerance to flooding stress.

Flooding and Atmospheric Rivers across the Western United States

NASA Astrophysics Data System (ADS)

Villarini, G.; Barth, N. A.; White, K. D.

2017-12-01

Flood frequency analysis across the western United States is complicated by annual peak flow records that frequently contain flows generated from distinctly different flood generating mechanisms. Among the different flood agents, atmospheric rivers (ARs) are responsible for large, regional scale floods. USGS streamgaging stations in the central Columbia River Basin in the Pacific Northwest, the Sierra Nevada, the central and southern California coast, and central Arizona show a mixture of 30-70% AR-generated flood peaks among the complete period of record. Bulletin17B and its proposed update (Draft Bulletin 17C) continue to recognize difficulties in determining flood frequency estimates among streamflow records that contain flood peaks coming from different flood-generating mechanisms, as is the case in the western United States. They recommend developing separate frequency curves when the hydrometeorologic mechanisms that generated the annual peak flows can be separated into distinct subpopulations. Yet challenges arise when trying to consistently quantify the physical (hydrometeorologic) processes that generated the observed flows, and even more when trying to account for them in flood frequency estimation. This study provides a general statistical framework to perform a process-driven flood frequency analysis using a weighted mixed population approach, highlighting the role that ARs play on the flood peak distribution.

Multi-dimensional flood vulnerability assessment using data envelopment analysis

NASA Astrophysics Data System (ADS)

Zahid, Zalina; Saharizan, Nurul Syuhada; Hamzah, Paezah; Hussin, Siti Aida Sheikh; Khairi, Siti Shaliza Mohd

2017-11-01

Malaysia has been greatly impacted by flood during monsoon seasons. Even though flood prone areas are well identified, assessment on the vulnerability of the disaster is lacking. Assessment of flood vulnerability, defined as the potential for loss when a disaster occurs, is addressed in this paper. The focus is on the development of flood vulnerability measurement in 11 states in Peninsular Malaysia using a non-parametric approach of Data Envelopment Analysis. Scores for three dimensions of flood vulnerability (Population Vulnerability, Social Vulnerability and Biophysical) were calculated using secondary data of selected input and output variables across an 11-year period from 2004 to 2014. The results showed that Johor and Pahang were the most vulnerable to flood in terms of Population Vulnerability, followed by Kelantan, the most vulnerable to flood in terms of Social Vulnerability and Kedah, Pahang and Terengganu were the most vulnerable to flood in terms of Biophysical Vulnerability among the eleven states. The results also showed that the state of Johor, Pahang and Kelantan to be most vulnerable across the three dimensions. Flood vulnerability assessment is important as it provides invaluable information that will allow the authority to identify and develop plans for flood mitigation and to reduce the vulnerability of flood at the affected regions.

Implementing the EU Floods Directive (2007/60/EC) in Austria: Flood Risk Management Plans

NASA Astrophysics Data System (ADS)

Neuhold, Clemens

2013-04-01

he Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007 on the assessment and management of flood risks (EFD) aims at the reduction of the adverse consequences for human health, the environment, cultural heritage and economic activity associated with floods in the Community. This task is to be achieved based on three process steps (1) preliminary flood risk assessment (finalised by the end of 2011), (2) flood hazard maps and flood risk maps (due 2013) and (3) flood risk management plans (due 2015). Currently, an interdisciplinary national working group is defining the methodological framework for flood risk management plans in Austria supported by a constant exchange with international bodies and experts. Referring to the EFD the components of the flood risk management plan are (excerpt): 1. conclusions of the preliminary flood risk assessment 2. flood hazard maps and flood risk maps and the conclusions that can be drawn from those maps 3. a description of the appropriate objectives of flood risk management 4. a summary of measures and their prioritisation aiming to achieve the appropriate objectives of flood risk management The poster refers to some of the major challenges in this process, such as the legal provisions, coordination of administrative units, definition of public relations, etc. The implementation of the EFD requires the harmonisation of legal instruments of various disciplines (e.g. water management, spatial planning, civil protection) enabling a coordinated - and ideally binding - practice of flood risk management. This process is highly influenced by the administrative organisation in Austria - federal, provincial and municipality level. The Austrian approach meets this organisational framework by structuring the development of the flood risk management plan into 3 time-steps: (a) federal blueprint, (b) provincial editing and (c) federal finishing as well as reporting to the European Commission. Each time-step addresses different administrative levels and spatial scales accompanied by the active involvement of interested parties.

Non—Linear Flood Assessment with Neural Network

NASA Astrophysics Data System (ADS)

Murariu, Gabriel; Puscasu, Gheorghe; Gogoncea, Vlad

2010-01-01

In our days, theoretical investigations are used in obtaining the mathematical model for the studied systems or processes. In general, the dynamics of the system are deeply nonlinear, complex or unknown. Generally speaking, such complex structure is a set of interconnected components. The common approach is therefore to start from measurements of the behavior of the system and the external influences (inputs) and try to determine a mathematical relation between them without going into the details of what is actually happening inside the system. Such strategy had known a great success during the time and it was applied for a large class of multifaceted processes. Accepting this approach, there could be investigated the climatic phenomena. In this paper is presented, in a comparative way, a non-linear water flood assessment made in a very sensitive area of the Lower Danube zone where, in the past years, a series of climatic problems have been happening. In these conditions, climatic risk factor management is a necessity. In a regular way, there could be considered and designed nonlinear models for the climatic factors' analysis by using a huge historical evidence data archive. In a previous paper we reached a notable intermediary result basing on a mathematical model constructed on internal recurrent neural network structure. Such approach had been presented considering the internal state estimation when no measurements coming from the sensors are available for system states. A modified backpropagation algorithm had been introduced in order to train the internal recurrent neural networks for nonlinear system identification. In this paper is exposed a comparative study between a numerical advances based on fluid dynamics' equations and our previous approach, based on internal recurrent neural networks (IRNN). The numerical approaching was made in order to succeed in building a physics model of a water flow evaluation and further, to achieve including the rainfall contributions. This condition is necessary for prediction and it is the first step toward a DSS—Decision Support System in the area. The relationship between the simulated results and the registered data allows considering our particular method to be useful for considered water flood assessment.

Flood-prone area maps of three sites along the Trans-Alaska Pipeline, Alaska

USGS Publications Warehouse

Lamke, Robert D.; Jones, Stanley H.

1980-01-01

Flood-prone areas in Alaska are delineated on aerial photographs for the Sagavanirktok River near Pump Station 3, Middle Fork Koyukuk River at Coldfoot, and Jim River near Pump Station 5. An analysis of available flood data and a description of recent flood evidence and maximum evident flood marks are included. (Kosco-USGS)

Floodflow characteristics at proposed bridge site on Fishkill Creek, Fishkill, New York

USGS Publications Warehouse

Zembrzuski, Thomas J.; Dunn, Bernard

1976-01-01

An evaluation of floodflow characteristics of Fishkill Creek at the proposed bridge site at Fishkill, N.Y., was made for the 50- and 100-year floods. The flood-frequency analysis revealed that the magnitude of the 50- and 100-year floods are 8,000 cubic feet per second (cfs) and 10,000 cfs, respectively. The normal water-surface elevation at the approach cross section was determined by the slope-conveyance method to be 209.8 feet during a 50-year flood and 210.8 feet during a 100-year flood. Also included is an analysis of the effect of the existing bridge and of two alternative bridge designs on the profiles of floods having recurrence intervals of 50 and 100 years. (Woodard-USGS)

Analysis of flood inundation in ungauged basins based on multi-source remote sensing data.

PubMed

Gao, Wei; Shen, Qiu; Zhou, Yuehua; Li, Xin

2018-02-09

Floods are among the most expensive natural hazards experienced in many places of the world and can result in heavy losses of life and economic damages. The objective of this study is to analyze flood inundation in ungauged basins by performing near-real-time detection with flood extent and depth based on multi-source remote sensing data. Via spatial distribution analysis of flood extent and depth in a time series, the inundation condition and the characteristics of flood disaster can be reflected. The results show that the multi-source remote sensing data can make up the lack of hydrological data in ungauged basins, which is helpful to reconstruct hydrological sequence; the combination of MODIS (moderate-resolution imaging spectroradiometer) surface reflectance productions and the DFO (Dartmouth Flood Observatory) flood database can achieve the macro-dynamic monitoring of the flood inundation in ungauged basins, and then the differential technique of high-resolution optical and microwave images before and after floods can be used to calculate flood extent to reflect spatial changes of inundation; the monitoring algorithm for the flood depth combining RS and GIS is simple and easy and can quickly calculate the depth with a known flood extent that is obtained from remote sensing images in ungauged basins. Relevant results can provide effective help for the disaster relief work performed by government departments.

The Tous Dam Disaster of 1982: Risk communication and the origins of integrated flood risk management in Spain

NASA Astrophysics Data System (ADS)

Serra-Llobet, A.; Tàbara, J.; Sauri, D.

2012-12-01

The failure of Tous dam on the Júcar River near Valencia in 1982 was one of the most important socio-natural disasters in 20th century Spain. The death toll of 25 would have been much greater had not a local dam manager anticipated the failure and alerted mayors of a failure, before it actually occurred. The Tous Dam failure occurred a week before the first democratic elections in Spain after the Franco dictatorship, it received extensive coverage in the media. As a result, this disaster triggered a paradigm change in the way disaster risks were perceived and managed at multiple levels of government in Spain. Many factors, often of a qualitative and organisational nature, affect (vertical and horizontal) communication in disaster risk reduction learning and planning at the community level. Through interviews with key actors and stakeholders, content analysis of scientific literature, review of historical and media accounts, and analysis of legislation and regulation, we documented changes that resulted from the Tous Dam failure: (1) A process of institutional development, which led to the growth, and increase in complexity of the organisations involved both in vertical and horizontal communication of disaster risk reduction. (2) Actions taken and experiences gained in dealing with disaster risk reduction in the Tous area were used as a benchmark to develop new strategies, as well as new mechanisms for communication and planning in other territories and other risk domains in Spain.We identify three main stages from 1980s to present in the evolution of disaster risk reduction planning in the area, which show a progressive shift towards a more integrated and preventative approach: (1) After the collapse of the Tous Dam, disaster risk reduction strategies in Spain focused on improving preparedness in order to reduce short-term risks. (2) Disaster management in the 1990s was strongly influenced by international initiatives (e.g. the UN International Decade for Natural Disaster Reduction), which emphasized the contextualization of risk and the importance in long-term disaster risk reduction measures such as land use planning. (3) The European Water Framework Directive (2000) and, more recently, the Flood Directive (2007) are exerting a strong influence on the development of a new Spanish flood policy that focuses on preventive measures and integrates, for the first time, ecological concerns and climate change adaptation in flood management strategies.

Characterising Record Flooding in the United Kingdom

NASA Astrophysics Data System (ADS)

Cox, A.; Bates, P. D.; Smith, J. A.

2017-12-01

Though the most notable floods in history have been carefully explained, there remains a lack of literature that explores the nature of record floods as a whole in the United Kingdom. We characterise the seasonality, statistical and spatial distribution, and meteorological causes of peak river flows for 521 gauging stations spread across the British Isles. We use annual maximum data from the National River Flow Archive, catchment descriptors from the Flood Estimation Handbook, and historical records of large floods. What we aim to find is in what ways, if any, the record flood for a station is different from more 'typical' floods. For each station, we calculate two indices: the seasonal anomaly and the flood index. Broadly, the seasonal anomaly is the degree to which a station's record flood happens at a different time of year compared to typical floods at that site, whilst the flood index is a station's record flood discharge divided by the discharge of the 1-in-10-year return period event. We find that while annual maximum peaks are dominated by winter frontal rainfall, record floods are disproportionately caused by summer convective rainfall. This analysis also shows that the larger the seasonal anomaly, the higher the flood index. Additionally, stations across the country have record floods that occur in the summer with no notable spatial pattern, yet the most seasonally anomalous record events are concentrated around the south and west of the British Isles. Catchment descriptors tell us little about the flood index at a particular station, but generally areas with lower mean annual precipitation have a higher flood index. The inclusion of case studies from recent and historical examples of notable floods across the UK supplements our analysis and gives insight into how typical these events are, both statistically and meteorologically. Ultimately, record floods in general happen at relatively unexpected times and with unpredictable magnitudes, which is a worrying reality for those who live in flood-prone areas, and to those who study the upper tail of flood events.

A data fusion framework for floodplain analysis using GIS and remotely sensed data

NASA Astrophysics Data System (ADS)

Necsoiu, Dorel Marius

Throughout history floods have been part of the human experience. They are recurring phenomena that form a necessary and enduring feature of all river basin and lowland coastal systems. In an average year, they benefit millions of people who depend on them. In the more developed countries, major floods can be the largest cause of economic losses from natural disasters, and are also a major cause of disaster-related deaths in the less developed countries. Flood disaster mitigation research was conducted to determine how remotely sensed data can effectively be used to produce accurate flood plain maps (FPMs), and to identify/quantify the sources of error associated with such data. Differences were analyzed between flood maps produced by an automated remote sensing analysis tailored to the available satellite remote sensing datasets (rFPM), the 100-year flooded areas "predicted" by the Flood Insurance Rate Maps, and FPMs based on DEM and hydrological data (aFPM). Landuse/landcover was also examined to determine its influence on rFPM errors. These errors were identified and the results were integrated in a GIS to minimize landuse/landcover effects. Two substantial flood events were analyzed. These events were selected because of their similar characteristics (i.e., the existence of FIRM or Q3 data; flood data which included flood peaks, rating curves, and flood profiles; and DEM and remote sensing imagery). Automatic feature extraction was determined to be an important component for successful flood analysis. A process network, in conjunction with domain specific information, was used to map raw remotely sensed data onto a representation that is more compatible with a GIS data model. From a practical point of view, rFPM provides a way to automatically match existing data models to the type of remote sensing data available for each event under investigation. Overall, results showed how remote sensing could contribute to the complex problem of flood management by providing an efficient way to revise the National Flood Insurance Program maps.

Reconstruction of flood events based on documentary data and transnational flood risk analysis of the Upper Rhine and its French and German tributaries since AD 1480

NASA Astrophysics Data System (ADS)

Himmelsbach, I.; Glaser, R.; Schoenbein, J.; Riemann, D.; Martin, B.

2015-10-01

This paper presents the long-term analysis of flood occurrence along the southern part of the Upper Rhine River system and of 14 of its tributaries in France and Germany covering the period starting from 1480 BC. Special focus is given on the temporal and spatial variations of flood events and their underlying meteorological causes over time. Examples are presented of how long-term information about flood events and knowledge about the historical aspect of flood protection in a given area can help to improve the understanding of risk analysis and therefor transnational risk management. Within this context, special focus is given to flood vulnerability while comparing selected historical and modern extreme events, establishing a common evaluation scheme. The transnational aspect becomes especially evident analyzing the tributaries: on this scale, flood protection developed impressively different on the French and German sides. We argue that comparing high technological standards of flood protection, which were initiated by the dukes of Baden on the German side starting in the early 19th century, misled people to the common belief that the mechanical means of flood protection like dams and barrages can guarantee the security from floods and their impacts. This lead to widespread settlements and the establishment of infrastructure as well as modern industries in potentially unsafe areas until today. The legal status in Alsace on the French side of the Rhine did not allow for continuous flood protection measurements, leading to a constant - and probably at last annoying - reminder that the floodplains are a potentially unsafe place to be. From a modern perspective of flood risk management, this leads to a significant lower aggregation of value in the floodplains of the small rivers in Alsace compared to those on the Baden side - an interesting fact - especially if the modern European Flood directive is taken into account.

Flood Frequency Analysis using different flood descriptors - the Warsaw reach of the river Vistula case study

NASA Astrophysics Data System (ADS)

Karamuz, Emilia; Kochanek, Krzysztof; Romanowicz, Renata

2014-05-01

Flood frequency analysis (FFA) is customarily performed using annual maximum flows. However, there is a number of different flood descriptors that could be used. Among them are water levels, peaks over the threshold, flood-wave duration, flood volume, etc. In this study we compare different approaches to FFA for their suitability for flood risk assessment. The main goal is to obtain the FFA curve with the smallest possible uncertainty limits, in particular for the distribution tail. The extrapolation of FFA curves is crucial in future flood risk assessment in a changing climate. We compare the FFA curves together with their uncertainty limits obtained using flows, water levels, flood inundation area and volumes for the Warsaw reach of the river Vistula. Moreover, we derive the FFA curves obtained using simulated flows. The results are used to derive the error distribution for the maximum simulated and observed values under different modelling techniques and assess its influence on flood risk predictions for ungauged catchments. MIKE11, HEC-RAS and transfer function model are applied in average and extreme conditions to model flow propagation in the Warsaw Vistula reach. The additional questions we want to answer are what is the range of application of different modelling tools under various flow conditions and how can the uncertainty of flood risk assessment be decreased. This work was partly supported by the projects "Stochastic flood forecasting system (The River Vistula reach from Zawichost to Warsaw)" and "Modern statistical models for analysis of flood frequency and features of flood waves", carried by the Institute of Geophysics, Polish Academy of Sciences on the order of the National Science Centre (contracts Nos. 2011/01/B/ST10/06866 and 2012/05/B/ST10/00482, respectively). The water level and flow data were provided by the Institute of Meteorology and Water Management (IMGW), Poland.

Do regional methods really help reduce uncertainties in flood frequency analyses?

NASA Astrophysics Data System (ADS)

Cong Nguyen, Chi; Payrastre, Olivier; Gaume, Eric

2013-04-01

Flood frequency analyses are often based on continuous measured series at gauge sites. However, the length of the available data sets is usually too short to provide reliable estimates of extreme design floods. To reduce the estimation uncertainties, the analyzed data sets have to be extended either in time, making use of historical and paleoflood data, or in space, merging data sets considered as statistically homogeneous to build large regional data samples. Nevertheless, the advantage of the regional analyses, the important increase of the size of the studied data sets, may be counterbalanced by the possible heterogeneities of the merged sets. The application and comparison of four different flood frequency analysis methods to two regions affected by flash floods in the south of France (Ardèche and Var) illustrates how this balance between the number of records and possible heterogeneities plays in real-world applications. The four tested methods are: (1) a local statistical analysis based on the existing series of measured discharges, (2) a local analysis valuating the existing information on historical floods, (3) a standard regional flood frequency analysis based on existing measured series at gauged sites and (4) a modified regional analysis including estimated extreme peak discharges at ungauged sites. Monte Carlo simulations are conducted to simulate a large number of discharge series with characteristics similar to the observed ones (type of statistical distributions, number of sites and records) to evaluate to which extent the results obtained on these case studies can be generalized. These two case studies indicate that even small statistical heterogeneities, which are not detected by the standard homogeneity tests implemented in regional flood frequency studies, may drastically limit the usefulness of such approaches. On the other hand, these result show that the valuation of information on extreme events, either historical flood events at gauged sites or estimated extremes at ungauged sites in the considered region, is an efficient way to reduce uncertainties in flood frequency studies.

3D Simulation of External Flooding Events for the RISMC Pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prescott, Steven; Mandelli, Diego; Sampath, Ramprasad

2015-09-01

Incorporating 3D simulations as part of the Risk-Informed Safety Margins Characterization (RISMIC) Toolkit allows analysts to obtain a more complete picture of complex system behavior for events including external plant hazards. External events such as flooding have become more important recently – however these can be analyzed with existing and validated simulated physics toolkits. In this report, we describe these approaches specific to flooding-based analysis using an approach called Smoothed Particle Hydrodynamics. The theory, validation, and example applications of the 3D flooding simulation are described. Integrating these 3D simulation methods into computational risk analysis provides a spatial/visual aspect to themore » design, improves the realism of results, and can prove visual understanding to validate the analysis of flooding.« less

Flood Discharge Analysis with Nakayasu Method Using Combination of HEC-RAS Method on Deli River in Medan City

NASA Astrophysics Data System (ADS)

Harahap, Rumilla; Jeumpa, Kemala; Hadibroto, Bambang

2018-03-01

The problem in this research is how in the rainy season the water does not overflow, does not occur flood and during the dry season does not occur drought so it can adjust the condition or existence of Deli river which is around Medan city. Deli River floods often occur, either caused by a smaller capacity than the existing discharge, lack of maintenance and drainage and disposal systems that do not fit with the environment, resulting in flood subscriptions every year. The purpose of this research is to know flood discharge at Deli river as Flood control in Medan city. This research is analyzed on several methods such as log Pearson, Gumbel and hydrograph unit, while HEC-RAS method is modeling conducted in analyzing the water profile of the Deli River. Furthermore, the calculation of the periodic flood discharge using the Nakayasu Method. Calculation result at Deli River return period flood discharge 2 years with an area of 14.8 km2 annual flood hydrograph the total is 26.79 m3/sec on the hours at the 4th time. Return period flood discharge 5 years with an area of 14.8 km2 annual flood hydrograph the total is 73,44 m3/sec. While 25 annual return period total flood hydrograph is 146.50 m3/sec. With flood analysis can reduce and minimize the risk of losses and land can be mapped if in the area there is flooding.

Understanding high magnitude flood risk: evidence from the past

NASA Astrophysics Data System (ADS)

MacDonald, N.

2009-04-01

The average length of gauged river flow records in the UK is ~25 years, which presents a problem in determining flood risk for high-magnitude flood events. Severe floods have been recorded in many UK catchments during the past 10 years, increasing the uncertainty in conventional flood risk estimates based on river flow records. Current uncertainty in flood risk has implications for society (insurance costs), individuals (personal vulnerability) and water resource managers (flood/drought risk). An alternative approach is required which can improve current understanding of the flood frequency/magnitude relationship. Historical documentary accounts are now recognised as a valuable resource when considering the flood frequency/magnitude relationship, but little consideration has been given to the temporal and spatial distribution of these records. Building on previous research based on British rivers (urban centre): Ouse (York), Trent (Nottingham), Tay (Perth), Severn (Shrewsbury), Dee (Chester), Great Ouse (Cambridge), Sussex Ouse (Lewes), Thames (Oxford), Tweed (Kelso) and Tyne (Hexham), this work considers the spatial and temporal distribution of historical flooding. The selected sites provide a network covering many of the largest river catchments in Britain, based on urban centres with long detailed documentary flood histories. The chronologies offer an opportunity to assess long-term patterns of flooding, indirectly determining periods of climatic variability and potentially increased geomorphic activity. This research represents the first coherent large scale analysis undertaken of historical multi-catchment flood chronologies, providing an unparalleled network of sites, permitting analysis of the spatial and temporal distribution of historical flood patterns on a national scale.

The Bisagno stream catchment (Genoa, Italy) and its major floods: geomorphic and land use variations in the last three centuries

NASA Astrophysics Data System (ADS)

Faccini, Francesco; Paliaga, Guido; Piana, Pietro; Sacchini, Alessandro; Watkins, Charles

2016-11-01

The city of Genoa (Liguria, Italy) and the Bisagno Valley are affected by frequent floods, often with loss of human lives. Historically characterised by high flood hazards, the Bisagno Valley was recently affected by a flood event on 9 October 2014, less than three years after the tragic flood event of 4 November 2011 when six people died, including two children. In the last 50 years, four destructive floods occurred in the Bisagno Valley, in addition to some other events that caused significant damage and economic losses. This paper examines the three largest flood events in terms of intensity and ground effects which affected the Bisagno Valley in the last three centuries: the flood of 25 October 1822, well documented by contemporary sources, the flood of 8 October 1970, undoubtedly the most tragic on record, and the very recent event of 9 October 2014. For this purpose scientific and historical-geographical methodologies were adopted, the latter particularly useful for the reconstruction of the flood event of 1822 and the landscape history of the Bisagno Valley in the nineteenth century. This comparison shows that the Bisagno Valley is characterised by climatic and landform features that have been making the flood events historically common in the area. However, recent climate change and land-use variations, including some major modifications of the catchment basin, have progressively determined a decrease of the concentration time and an increase of runoff, solid transport, and flood hazard. Consequently, in recent decades a growth in the number of flood events occurred, to the extent that the Bisagno today is a famous case study on an international scale.

How extreme was the October 2015 flood in the Carolinas? An assessment of flood frequency analysis and distribution tails

NASA Astrophysics Data System (ADS)

Phillips, R. C.; Samadi, S. Z.; Meadows, M. E.

2018-07-01

This paper examines the frequency, distribution tails, and peak-over-threshold (POT) of extreme floods through analysis that centers on the October 2015 flooding in North Carolina (NC) and South Carolina (SC), United States (US). The most striking features of the October 2015 flooding were a short time to peak (Tp) and a multi-hour continuous flood peak which caused intensive and widespread damages to human lives, properties, and infrastructure. The 2015 flooding was produced by a sequence of intense rainfall events which originated from category 4 hurricane Joaquin over a period of four days. Here, the probability distribution and distribution parameters (i.e., location, scale, and shape) of floods were investigated by comparing the upper part of empirical distributions of the annual maximum flood (AMF) and POT with light- to heavy- theoretical tails: Fréchet, Pareto, Gumbel, Weibull, Beta, and Exponential. Specifically, four sets of U.S. Geological Survey (USGS) gauging data from the central Carolinas with record lengths from approximately 65-125 years were used. Analysis suggests that heavier-tailed distributions are in better agreement with the POT and somewhat AMF data than more often used exponential (light) tailed probability distributions. Further, the threshold selection and record length affect the heaviness of the tail and fluctuations of the parent distributions. The shape parameter and its evolution in the period of record play a critical and poorly understood role in determining the scaling of flood response to intense rainfall.

A Global Geospatial Database of 5000+ Historic Flood Event Extents

NASA Astrophysics Data System (ADS)

Tellman, B.; Sullivan, J.; Doyle, C.; Kettner, A.; Brakenridge, G. R.; Erickson, T.; Slayback, D. A.

2017-12-01

A key dataset that is missing for global flood model validation and understanding historic spatial flood vulnerability is a global historical geo-database of flood event extents. Decades of earth observing satellites and cloud computing now make it possible to not only detect floods in near real time, but to run these water detection algorithms back in time to capture the spatial extent of large numbers of specific events. This talk will show results from the largest global historical flood database developed to date. We use the Dartmouth Flood Observatory flood catalogue to map over 5000 floods (from 1985-2017) using MODIS, Landsat, and Sentinel-1 Satellites. All events are available for public download via the Earth Engine Catalogue and via a website that allows the user to query floods by area or date, assess population exposure trends over time, and download flood extents in geospatial format.In this talk, we will highlight major trends in global flood exposure per continent, land use type, and eco-region. We will also make suggestions how to use this dataset in conjunction with other global sets to i) validate global flood models, ii) assess the potential role of climatic change in flood exposure iii) understand how urbanization and other land change processes may influence spatial flood exposure iv) assess how innovative flood interventions (e.g. wetland restoration) influence flood patterns v) control for event magnitude to assess the role of social vulnerability and damage assessment vi) aid in rapid probabilistic risk assessment to enable microinsurance markets. Authors on this paper are already using the database for the later three applications and will show examples of wetland intervention analysis in Argentina, social vulnerability analysis in the USA, and micro insurance in India.

Can global hydrological models reproduce large scale river flood regimes?

NASA Astrophysics Data System (ADS)

Eisner, Stephanie; Flörke, Martina

2013-04-01

River flooding remains one of the most severe natural hazards. On the one hand, major flood events pose a serious threat to human well-being, causing deaths and considerable economic damage. On the other hand, the periodic occurrence of flood pulses is crucial to maintain the functioning of riverine floodplains and wetlands, and to preserve the ecosystem services the latter provide. In many regions, river floods reveal a distinct seasonality, i.e. they occur at a particular time during the year. This seasonality is related to regionally dominant flood generating processes which can be expressed in river flood types. While in data-rich regions (esp. Europe and North America) the analysis of flood regimes can be based on observed river discharge time series, this data is sparse or lacking in many other regions of the world. This gap of knowledge can be filled by global modeling approaches. However, to date most global modeling studies have focused on mean annual or monthly water availability and their change over time while simulating discharge extremes, both floods and droughts, still remains a challenge for large scale hydrological models. This study will explore the ability of the global hydrological model WaterGAP3 to simulate the large scale patterns of river flood regimes, represented by seasonal pattern and the dominant flood type. WaterGAP3 simulates the global terrestrial water balance on a 5 arc minute spatial grid (excluding Greenland and Antarctica) at a daily time step. The model accounts for human interference on river flow, i.e. water abstraction for various purposes, e.g. irrigation, and flow regulation by large dams and reservoirs. Our analysis will provide insight in the general ability of global hydrological models to reproduce river flood regimes and thus will promote the creation of a global map of river flood regimes to provide a spatially inclusive and comprehensive picture. Understanding present-day flood regimes can support both flood risk analysis and the assessment of potential regional impacts of climate change on river flooding.

Quantifying invertebrate resistance to floods: a global-scale meta-analysis.

PubMed

McMullen, Laura E; Lytle, David A

2012-12-01

Floods are a key component of the ecology and management of riverine ecosystems around the globe, but it is not clear whether floods have predictable effects on organisms that can allow us to generalize across regions and continents. To address this, we conducted a global-scale meta-analysis to investigate effects of natural and managed floods on invertebrate resistance, the ability of invertebrates to survive flood events. We considered 994 studies for inclusion in the analysis, and after evaluation based on a priori criteria, narrowed our analysis to 41 studies spanning six of the seven continents. We used the natural-log-ratio of invertebrate abundance before and within 10 days after flood events because this measure of effect size can be directly converted to estimates of percent survival. We conducted categorical and continuous analyses that examined the contribution of environmental and study design variables to effect size heterogeneity, and examined differences in effect size among taxonomic groups. We found that invertebrate abundance was lowered by at least one-half after flood events. While natural vs. managed floods were similar in their effect, effect size differed among habitat and substrate types, with pools, sand, and boulders experiencing the strongest effect. Although sample sizes were not sufficient to examine all taxonomic groups, floods had a significant, negative effect on densities of Coleoptera, Eumalacostraca, Annelida, Ephemeroptera, Diptera, Plecoptera, and Trichoptera. Results from this study provide guidance for river flow regime prescriptions that will be applicable across continents and climate types, as well as baseline expectations for future empirical studies of freshwater disturbance.

Dam-breach analysis and flood-inundation mapping for selected dams in Oklahoma City, Oklahoma, and near Atoka, Oklahoma

USGS Publications Warehouse

Shivers, Molly J.; Smith, S. Jerrod; Grout, Trevor S.; Lewis, Jason M.

2015-01-01

Digital-elevation models, field survey measurements, hydraulic data, and hydrologic data (U.S. Geological Survey streamflow-gaging stations North Canadian River below Lake Overholser near Oklahoma City, Okla. [07241000], and North Canadian River at Britton Road at Oklahoma City, Okla. [07241520]), were used as inputs for the one-dimensional dynamic (unsteady-flow) models using Hydrologic Engineering Centers River Analysis System (HEC–RAS) software. The modeled flood elevations were exported to a geographic information system to produce flood-inundation maps. Water-surface profiles were developed for a 75-percent probable maximum flood dam-breach scenario and a sunny-day dam-breach scenario, as well as for maximum flood-inundation elevations and flood-wave arrival times at selected bridge crossings. Points of interest such as community-services offices, recreational areas, water-treatment plants, and wastewater-treatment plants were identified on the flood-inundation maps.

Remote collection and analysis of witness reports on flash floods

NASA Astrophysics Data System (ADS)

Gourley, Jonathan; Erlingis, Jessica; Smith, Travis; Ortega, Kiel; Hong, Yang

2010-05-01

Typically, flash floods are studied ex post facto in response to a major impact event. A complement to field investigations is developing a detailed database of flash flood events, including minor events and null reports (i.e., where heavy rain occurred but there was no flash flooding), based on public survey questions conducted in near-real time. The Severe Hazards Analysis and Verification Experiment (SHAVE) has been in operation at the National Severe Storms Laboratory (NSSL) in Norman, OK, USA during the summers since 2006. The experiment employs undergraduate students to analyse real-time products from weather radars, target specific regions within the conterminous US, and poll public residences and businesses regarding the occurrence and severity of hail, wind, tornadoes, and now flash floods. In addition to providing a rich learning experience for students, SHAVE has been successful in creating high-resolution datasets of severe hazards used for algorithm and model verification. This talk describes the criteria used to initiate the flash flood survey, the specific questions asked and information entered to the database, and then provides an analysis of results for flash flood data collected during the summer of 2008. It is envisioned that specific details provided by the SHAVE flash flood observation database will complement databases collected by operational agencies and thus lead to better tools to predict the likelihood of flash floods and ultimately reduce their impacts on society.

Ethylene--and oxygen signalling--drive plant survival during flooding.

PubMed

Voesenek, L A C J; Sasidharan, R

2013-05-01

Flooding is a widely occurring environmental stress both for natural and cultivated plant species. The primary problems associated with flooding arise due to restricted gas diffusion underwater. This hampers gas exchange needed for the critical processes of photosynthesis and respiration. Plant acclimation to flooding includes the adaptation of a suite of traits that helps alleviate or avoid these stressful conditions and improves or restores exchange of O2 and CO2 . The manifestation of these traits is, however, reliant on the timely perception of signals that convey the underwater status. Flooding-associated reduced gas diffusion imposes a drastic change in the internal gas composition within submerged plant organs. One of the earliest changes is an increase in the levels of the gaseous plant hormone ethylene. Depending on the species, organ, flooding conditions and time of the day, plants will also subsequently experience a reduction in oxygen levels. This review provides a comprehensive overview on the roles of ethylene and oxygen as critical signals of flooding stress. It includes a discussion of the dynamics of these gases in plants when underwater, their interaction, current knowledge of their perception mechanisms and the resulting downstream changes that mediate important acclimative processes that allow endurance and survival under flooded conditions. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Combined fluvial and pluvial urban flood hazard analysis: concept development and application to Can Tho city, Mekong Delta, Vietnam

NASA Astrophysics Data System (ADS)

Apel, Heiko; Martínez Trepat, Oriol; Nghia Hung, Nguyen; Thi Chinh, Do; Merz, Bruno; Viet Dung, Nguyen

2016-04-01

Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either a fluvial or pluvial flood hazard, studies of a combined fluvial and pluvial flood hazard are hardly available. Thus this study aims to analyse a fluvial and a pluvial flood hazard individually, but also to develop a method for the analysis of a combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as an example. In this tropical environment the annual monsoon triggered floods of the Mekong River, which can coincide with heavy local convective precipitation events, causing both fluvial and pluvial flooding at the same time. The fluvial flood hazard was estimated with a copula-based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. The pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data and a stochastic rainstorm generator. Inundation for all flood scenarios was simulated by a 2-dimensional hydrodynamic model implemented on a Graphics Processing Unit (GPU) for time-efficient flood propagation modelling. The combined fluvial-pluvial flood scenarios were derived by adding rainstorms to the fluvial flood events during the highest fluvial water levels. The probabilities of occurrence of the combined events were determined assuming independence of the two flood types and taking the seasonality and probability of coincidence into account. All hazards - fluvial, pluvial and combined - were accompanied by an uncertainty estimation taking into account the natural variability of the flood events. This resulted in probabilistic flood hazard maps showing the maximum inundation depths for a selected set of probabilities of occurrence, with maps showing the expectation (median) and the uncertainty by percentile maps. The results are critically discussed and their usage in flood risk management are outlined.

A non-stationary cost-benefit based bivariate extreme flood estimation approach

NASA Astrophysics Data System (ADS)

Qi, Wei; Liu, Junguo

2018-02-01

Cost-benefit analysis and flood frequency analysis have been integrated into a comprehensive framework to estimate cost effective design values. However, previous cost-benefit based extreme flood estimation is based on stationary assumptions and analyze dependent flood variables separately. A Non-Stationary Cost-Benefit based bivariate design flood estimation (NSCOBE) approach is developed in this study to investigate influence of non-stationarities in both the dependence of flood variables and the marginal distributions on extreme flood estimation. The dependence is modeled utilizing copula functions. Previous design flood selection criteria are not suitable for NSCOBE since they ignore time changing dependence of flood variables. Therefore, a risk calculation approach is proposed based on non-stationarities in both marginal probability distributions and copula functions. A case study with 54-year observed data is utilized to illustrate the application of NSCOBE. Results show NSCOBE can effectively integrate non-stationarities in both copula functions and marginal distributions into cost-benefit based design flood estimation. It is also found that there is a trade-off between maximum probability of exceedance calculated from copula functions and marginal distributions. This study for the first time provides a new approach towards a better understanding of influence of non-stationarities in both copula functions and marginal distributions on extreme flood estimation, and could be beneficial to cost-benefit based non-stationary bivariate design flood estimation across the world.

Soil archives of a Fluvisol: Subsurface analysis and soil history of the medieval city centre of Vlaardingen, the Netherlands - an integral approach

NASA Astrophysics Data System (ADS)

Kluiving, Sjoerd; De Ridder, Tim; Van Dasselaar, Marcel; Roozen, Stan; Prins, Maarten; Van Mourik, Jan

2016-04-01

In Medieval times the city of Vlaardingen (the Netherlands) was strategically located on the confluence of three rivers, the Meuse, the Merwede and the Vlaarding. A church of early 8th century was already located here. In a short period of time Vlaardingen developed into an international trading place, the most important place in the former county of Holland. Starting from the 11th century the river Meuse threatened to flood the settlement. These floods have been registered in the archives of the fluvisol and were recognised in a multidisciplinary sedimentary analysis of these archives. To secure the future of this vulnerable soil archive currently an extensive interdisciplinary research (76 mechanical drill holes, grain size analysis (GSA), thermo-gravimetric analysis (TGA), archaeological remains, soil analysis, dating methods, micromorphology, and microfauna has started in 2011 to gain knowledge on the sedimentological and pedological subsurface of the mound as well as on the well-preserved nature of the archaeological evidence. Pedogenic features are recorded with soil descriptive, micromorphological and geochemical (XRF) analysis. The soil sequence of 5 meters thickness exhibits a complex mix of 'natural' as well as 'anthropogenic layering' and initial soil formation that enables to make a distinction for relatively stable periods between periods with active sedimentation. In this paper the results of this large-scale project are demonstrated in a number of cross-sections with interrelated geological, pedological and archaeological stratification. Distinction between natural and anthropogenic layering is made on the occurrence of chemical elements phosphor and potassium. A series of four stratigraphic / sedimentary units record the period before and after the flooding disaster. Given the many archaeological remnants and features present in the lower units, we assume that the medieval landscape was drowned while it was inhabited in the 12th century AD. After a final drowning phase in the 13th century, as a reaction to it, inhabitants started to raise the surface.

A methodology using GIS, aerial photos and remote sensing for loss estimation and flood vulnerability analysis in the Supersano-Ruffano-Nociglia Graben, southern Italy

NASA Astrophysics Data System (ADS)

Forte, F.; Strobl, R. O.; Pennetta, L.

2006-07-01

The impact of calamitous meteoric events and their interaction with the geological and geomorphological environment represent a current problem of the Supersano-Ruffano-Nociglia Graben in southern Italy. Indeed, severe floods take place on a frequent basis not only in autumn and winter, but in summer also. These calamities are not only triggered by exceptional events, but are also amplified by peculiar geological and morpho-structural characteristics of the Graben. Flooding often affects vast agricultural areas and consequently, water-scooping machines cannot remove the rainwater. These events cause warnings and emergency states, involving people as well as socio economic goods. This study represents an application of a vanguard technique for loss estimation and flood vulnerability analysis, integrating a geographic information system (GIS) with aerial photos and remote sensing methods. The analysis results clearly show that the Graben area is potentially at greatest flood vulnerability, while along the Horsts the flood vulnerability is lower.

An analysis of the magnitude and frequency of floods on Oahu, Hawaii

USGS Publications Warehouse

Nakahara, R.H.

1980-01-01

An analysis of available peak-flow data for the island of Oahu, Hawaii, was made by using multiple regression techniques which related flood-frequency data to basin and climatic characteristics for 74 gaging stations on Oahu. In the analysis, several different groupings of stations were investigated, including divisions by geographic location and size of drainage area. The grouping consisting of two leeward divisions and one windward division produced the best results. Drainage basins ranged in area from 0.03 to 45.7 square miles. Equations relating flood magnitudes of selected frequencies to basin characteristics were developed for the three divisions of Oahu. These equations can be used to estimate the magnitude and frequency of floods for any site, gaged or ungaged, for any desired recurrence interval from 2 to 100 years. Data on basin characteristics, flood magnitudes for various recurrence intervals from individual station-frequency curves, and computed flood magnitudes by use of the regression equation are tabulated to provide the needed data. (USGS)

Characteristics of the April 2007 Flood at 10 Streamflow-Gaging Stations in Massachusetts

USGS Publications Warehouse

Zarriello, Phillip J.; Carlson, Carl S.

2009-01-01

A large 'nor'easter' storm on April 15-18, 2007, brought heavy rains to the southern New England region that, coupled with normal seasonal high flows and associated wet soil-moisture conditions, caused extensive flooding in many parts of Massachusetts and neighboring states. To characterize the magnitude of the April 2007 flood, a peak-flow frequency analysis was undertaken at 10 selected streamflow-gaging stations in Massachusetts to determine the magnitude of flood flows at 5-, 10-, 25-, 50-, 100-, 200-, and 500-year return intervals. The magnitude of flood flows at various return intervals were determined from the logarithms of the annual peaks fit to a Pearson Type III probability distribution. Analysis included augmenting the station record with longer-term records from one or more nearby stations to provide a common period of comparison that includes notable floods in 1936, 1938, and 1955. The April 2007 peak flow was among the highest recorded or estimated since 1936, often ranking between the 3d and 5th highest peak for that period. In general, the peak-flow frequency analysis indicates the April 2007 peak flow has an estimated return interval between 25 and 50 years; at stations in the northeastern and central areas of the state, the storm was less severe resulting in flows with return intervals of about 5 and 10 years, respectively. At Merrimack River at Lowell, the April 2007 peak flow approached a 100-year return interval that was computed from post-flood control records and the 1936 and 1938 peak flows adjusted for flood control. In general, the magnitude of flood flow for a given return interval computed from the streamflow-gaging station period-of-record was greater than those used to calculate flood profiles in various community flood-insurance studies. In addition, the magnitude of the updated flood flow and current (2008) stage-discharge relation at a given streamflow-gaging station often produced a flood stage that was considerably different than the flood stage indicated in the flood-insurance study flood profile at that station. Equations for estimating the flow magnitudes for 5-, 10-, 25-, 50-, 100-, 200-, and 500-year floods were developed from the relation of the magnitude of flood flows to drainage area calculated from the six streamflow-gaging stations with the longest unaltered record. These equations produced a more conservative estimate of flood flows (higher discharges) than the existing regional equations for estimating flood flows at ungaged rivers in Massachusetts. Large differences in the magnitude of flood flows for various return intervals determined in this study compared to results from existing regional equations and flood insurance studies indicate a need for updating regional analyses and equations for estimating the expected magnitude of flood flows in Massachusetts.

Re-assessing the flood risk in Scotland.

PubMed

Black, Andrew R; Burns, John C

2002-07-22

This paper presents a review of changes in flood risk estimation on Scottish rivers resulting from re-analysis of flood records or from the application of new methods. The review arises at a time when flood damages have received recent prominence through the occurrence of a number of extreme floods in Scotland, and when the possible impacts of climate change on flood risk are receiving considerable attention. An analysis of the nine longest available peaks-over-threshold (POT) flood series for Scottish rivers reveals that, for thresholds yielding two events per year on average, annual POT frequencies on western rivers have increased in the 1980s/1990s to maximum recorded values, while in the east, values were highest in the 1950s/1960s. These results support the results of flood modelling work based on rainfall and temperature records from the 1870s, which indicate that, in western catchments, annual POT frequencies in the 1980s/1990s are unprecedented. No general trends in flood magnitude series were found, but an unexpected cluster of extreme floods is identified as having occurred since 1988, resulting in eight of Scotland's 16 largest gauged rivers producing their maximum recorded flows since then. These shifts are related to recent increases in the dominance of westerly airflows, share similarities with the results of climate change modelling, and collectively point to increases in flood risk in many parts of Scotland. The paper also reviews advances in flood risk estimation arising from the publication of the UK Flood Estimation Handbook, developments in the collection and use of historic flood estimation and the production of maps of 100-year flood areal extent. Finally the challenges in flood risk estimation posed by climate change are examined, particularly in relation to the assumption of stationarity.

An Exploration of the Importance of Flood Heterogeneity for Regionalization in Arizona using the Expected Moments Algorithm

NASA Astrophysics Data System (ADS)

Zamora-Reyes, D.; Hirschboeck, K. K.; Paretti, N. V.

2012-12-01

Bulletin 17B (B17B) has prevailed for 30 years as the standard manual for determining flood frequency in the United States. Recently proposed updates to B17B include revising the issue of flood heterogeneity, and improving flood estimates by using the Expected Moments Algorithm (EMA) which can better address low outliers and accommodate information on historical peaks. Incorporating information on mixed populations, such as flood-causing mechanisms, into flood estimates for regions that have noticeable flood heterogeneity can be statistically challenging when systematic flood records are short. The problem magnifies when the population sample size is reduced by decomposing the record, especially if multiple flood mechanisms are involved. In B17B, the guidelines for dealing with mixed populations focus primarily on how to rule out any need to perform a mixed-population analysis. However, in some regions mixed flood populations are critically important determinants of regional flood frequency variations and should be explored from this perspective. Arizona is an area with a heterogeneous mixture of flood processes due to: warm season convective thunderstorms, cool season synoptic-scale storms, and tropical cyclone-enhanced convective activity occurring in the late summer or early fall. USGS station data throughout Arizona was compiled into a database and each flood peak (annual and partial duration series) was classified according to its meteorological cause. Using these data, we have explored the role of flood heterogeneity in Arizona flood estimates through composite flood frequency analysis based on mixed flood populations using EMA. First, for selected stations, the three flood-causing populations were separated out from the systematic annual flood series record and analyzed individually. Second, to create composite probability curves, the individual curves for each of the three populations were generated and combined using Crippen's (1978) composite probability equations for sites that have two or more independent flood populations. Finally, the individual probability curves generated for each of the three flood-causing populations were compared with both the site's composite probability curve and the standard B17B curve to explore the influence of heterogeneity using the 100-year and 200-year flood estimates as a basis of comparison. Results showed that sites located in southern Arizona and along the abrupt elevation transition zone of the Mogollon Rim exhibit a better fit to the systematic data using their composite probability curves than the curves derived from standard B17B analysis. Synoptic storm floods and tropical cyclone-enhanced floods had the greatest influence on 100-year and 200-year flood estimates. This was especially true in southern Arizona, even though summer convective floods are much more frequent and therefore dominate the composite curve. Using the EMA approach also influenced our results because all possible low outliers were censored by the built-in Multiple Grubbs-Beck Test, providing a better fit to the systematic data in the upper probabilities. In conclusion, flood heterogeneity can play an important role in regional flood frequency variations in Arizona and that understanding its influence is important when making projections about future flood variations.

Strengthening insurance partnerships in the face of climate change - Insights from an agent-based model of flood insurance in the UK.

PubMed

Crick, Florence; Jenkins, Katie; Surminski, Swenja

2018-04-25

Multisectoral partnerships are increasingly cited as a mechanism to deliver and improve disaster risk management. Yet, partnerships are not a panacea and more research is required to understand the role that they can play in disaster risk management and particularly disaster risk reduction. This paper investigates how partnerships can incentivise flood risk reduction by focusing on the UK public-private partnership on flood insurance. Developing the right flood insurance arrangements to incentivise flood risk reduction and adaptation to climate change is a key challenge. In the face of rising flood risks due to climate change and socio-economic development insurance partnerships can no longer afford to focus only on the risk transfer function. However, while expectations of the insurance industry have traditionally been high when it comes to flood risk management, the insurance industry alone will not provide the solution to the challenge of rising risks. The case of flood insurance in the UK illustrates this: even national government and industry together cannot fully address these risks and other actors need to be involved to create strong incentives for risk reduction. Using an agent-based model focused on surface water flood risk in London we analyse how other partners could strengthen the insurance partnership by reducing flood risk and thus helping to maintain affordable insurance premiums. Our findings are relevant for wider discussions on the potential of insurance schemes to incentivise flood risk management and climate adaptation in the UK and also internationally. Copyright © 2018. Published by Elsevier B.V.

Stationarity analysis of historical flood series in France and Spain (14th-20th centuries)

NASA Astrophysics Data System (ADS)

Barriendos, M.; Coeur, D.; Lang, M.; Llasat, M. C.; Naulet, R.; Lemaitre, F.; Barrera, A.

Interdisciplinary frameworks for studying natural hazards and their temporal trends have an important potential in data generation for risk assessment, land use planning, and therefore the sustainable management of resources. This paper focuses on the adjustments required because of the wide variety of scientific fields involved in the reconstruction and characterisation of flood events for the past 1000 years. The aim of this paper is to describe various methodological aspects of the study of flood events in their historical dimension, including the critical evaluation of old documentary and instrumental sources, flood-event classification and hydraulic modelling, and homogeneity and quality control tests. Standardized criteria for flood classification have been defined and applied to the Isère and Drac floods in France, from 1600 to 1950, and to the Ter, the Llobregat and the Segre floods, in Spain, from 1300 to 1980. The analysis on the Drac and Isère data series from 1600 to the present day showed that extraordinary and catastrophic floods were not distributed uniformly in time. However, the largest floods (general catastrophic floods) were homogeneously distributed in time within the period 1600-1900. No major flood occurred during the 20th century in these rivers. From 1300 to the present day, no homogeneous behaviour was observed for extraordinary floods in the Spanish rivers. The largest floods were uniformly distributed in time within the period 1300-1900, for the Segre and Ter rivers.

Comment on "Can assimilation of crowdsourced data in hydrological modelling improve flood prediction?" by Mazzoleni et al. (2017)

NASA Astrophysics Data System (ADS)

Viero, Daniele P.

2018-01-01

Citizen science and crowdsourcing are gaining increasing attention among hydrologists. In a recent contribution, Mazzoleni et al. (2017) investigated the integration of crowdsourced data (CSD) into hydrological models to improve the accuracy of real-time flood forecasts. The authors used synthetic CSD (i.e. not actually measured), because real CSD were not available at the time of the study. In their work, which is a proof-of-concept study, Mazzoleni et al. (2017) showed that assimilation of CSD improves the overall model performance; the impact of irregular frequency of available CSD, and that of data uncertainty, were also deeply assessed. However, the use of synthetic CSD in conjunction with (semi-)distributed hydrological models deserves further discussion. As a result of equifinality, poor model identifiability, and deficiencies in model structure, internal states of (semi-)distributed models can hardly mimic the actual states of complex systems away from calibration points. Accordingly, the use of synthetic CSD that are drawn from model internal states under best-fit conditions can lead to overestimation of the effectiveness of CSD assimilation in improving flood prediction. Operational flood forecasting, which results in decisions of high societal value, requires robust knowledge of the model behaviour and an in-depth assessment of both model structure and forcing data. Additional guidelines are given that are useful for the a priori evaluation of CSD for real-time flood forecasting and, hopefully, for planning apt design strategies for both model calibration and collection of CSD.

Quantitative analysis of burden of infectious diarrhea associated with floods in northwest of anhui province, china: a mixed method evaluation.

PubMed

Ding, Guoyong; Zhang, Ying; Gao, Lu; Ma, Wei; Li, Xiujun; Liu, Jing; Liu, Qiyong; Jiang, Baofa

2013-01-01

Persistent and heavy rainfall in the upper and middle Huaihe River of China brought about severe floods during the end of June and July 2007. However, there has been no assessment on the association between the floods and infectious diarrhea. This study aimed to quantify the impact of the floods in 2007 on the burden of disease due to infectious diarrhea in northwest of Anhui Province. A time-stratified case-crossover analysis was firstly conducted to examine the relationship between daily cases of infectious diarrhea and the 2007 floods in Fuyang and Bozhou of Anhui Province. Odds ratios (ORs) of the flood risk were quantified by conditional logistic regression. The years lived with disability (YLDs) of infectious diarrhea attributable to floods were then estimated based on the WHO framework of the calculating potential impact fraction in the Burden of Disease study. A total of 197 infectious diarrheas were notified during the exposure and control periods in the two study areas. The strongest effect was shown with a 2-day lag in Fuyang and a 5-day lag in Bozhou. Multivariable analysis showed that floods were significantly associated with an increased risk of the number cases of infectious diarrhea (OR = 3.175, 95%CI: 1.126-8.954 in Fuyang; OR = 6.754, 95%CI: 1.954-23.344 in Bozhou). Attributable YLD per 1000 of infectious diarrhea resulting from the floods was 0.0081 in Fuyang and 0.0209 in Bozhou. Our findings confirm that floods have significantly increased the risks of infectious diarrhea in the study areas. In addition, prolonged moderate flood may cause more burdens of infectious diarrheas than severe flood with a shorter duration. More attention should be paid to particular vulnerable groups, including younger children and elderly, in developing public health preparation and intervention programs. Findings have significant implications for developing strategies to prevent and reduce health impact of floods.

Flood risk assessment in France: comparison of extreme flood estimation methods (EXTRAFLO project, Task 7)

NASA Astrophysics Data System (ADS)

Garavaglia, F.; Paquet, E.; Lang, M.; Renard, B.; Arnaud, P.; Aubert, Y.; Carre, J.

2013-12-01

In flood risk assessment the methods can be divided in two families: deterministic methods and probabilistic methods. In the French hydrologic community the probabilistic methods are historically preferred to the deterministic ones. Presently a French research project named EXTRAFLO (RiskNat Program of the French National Research Agency, https://extraflo.cemagref.fr) deals with the design values for extreme rainfall and floods. The object of this project is to carry out a comparison of the main methods used in France for estimating extreme values of rainfall and floods, to obtain a better grasp of their respective fields of application. In this framework we present the results of Task 7 of EXTRAFLO project. Focusing on French watersheds, we compare the main extreme flood estimation methods used in French background: (i) standard flood frequency analysis (Gumbel and GEV distribution), (ii) regional flood frequency analysis (regional Gumbel and GEV distribution), (iii) local and regional flood frequency analysis improved by historical information (Naulet et al., 2005), (iv) simplify probabilistic method based on rainfall information (i.e. Gradex method (CFGB, 1994), Agregee method (Margoum, 1992) and Speed method (Cayla, 1995)), (v) flood frequency analysis by continuous simulation approach and based on rainfall information (i.e. Schadex method (Paquet et al., 2013, Garavaglia et al., 2010), Shyreg method (Lavabre et al., 2003)) and (vi) multifractal approach. The main result of this comparative study is that probabilistic methods based on additional information (i.e. regional, historical and rainfall information) provide better estimations than the standard flood frequency analysis. Another interesting result is that, the differences between the various extreme flood quantile estimations of compared methods increase with return period, staying relatively moderate up to 100-years return levels. Results and discussions are here illustrated throughout with the example of five watersheds located in the South of France. References : O. CAYLA : Probability calculation of design floods abd inflows - SPEED. Waterpower 1995, San Francisco, California 1995 CFGB : Design flood determination by the gradex method. Bulletin du Comité Français des Grands Barrages News 96, 18th congress CIGB-ICOLD n2, nov:108, 1994. F. GARAVAGLIA et al. : Introducing a rainfall compound distribution model based on weather patterns subsampling. Hydrology and Earth System Sciences, 14, 951-964, 2010. J. LAVABRE et al. : SHYREG : une méthode pour l'estimation régionale des débits de crue. application aux régions méditerranéennes françaises. Ingénierie EAT, 97-111, 2003. M. MARGOUM : Estimation des crues rares et extrêmes : le modèle AGREGEE. Conceptions et remières validations. PhD, Ecole des Mines de Paris, 1992. R. NAULET et al. : Flood frequency analysis on the Ardèche river using French documentary sources from the two last centuries. Journal of Hydrology, 313:58-78, 2005. E. PAQUET et al. : The SCHADEX method: A semi-continuous rainfall-runoff simulation for extreme flood estimation, Journal of Hydrology, 495, 23-37, 2013.

Aqueduct Global Flood Analyzer - bringing risk information to practice

NASA Astrophysics Data System (ADS)

Ward, Philip

2017-04-01

The economic losses associated with flooding are huge and rising. As a result, there is increasing attention for strategic flood risk assessments at the global scale. In response, the last few years have seen a large growth in the number of global flood models. At the same time, users and practitioners require flood risk information in a format that is easy to use, understandable, transparent, and actionable. In response, we have developed the Aqueduct Global Flood Analyzer (wri.org/floods). The Analyzer is a free, online, easy to use, tool for assessing global river flood risk at the scale of countries, states, and river basins, using data generated by the state of the art GLOFRIS global flood risk model. The Analyzer allows users to assess flood risk on-the-fly in terms of expected annual urban damage, and expected annual population and GDP affected by floods. Analyses can be carried out for current conditions and under future scenarios of climate change and socioeconomic development. We will demonstrate the tool, and discuss several of its applications in practice. In the past 15 months, the tool has been visited and used by more than 12,000 unique users from almost every country, including many users from the World Bank, Pacific Disaster Center, Red Cross Climate Centre, as well as many journalists from major international news outlets. Use cases will be presented from these user communities. We will also present ongoing research to improve the user functionality of the tool in the coming year. This includes the inclusion of coastal flood risk, assessing the costs and benefits of adaptation, and assessing the impacts of land subsidence and urban extension on risk.

Aqueduct Global Flood Analyzer - bringing risk information to practice

NASA Astrophysics Data System (ADS)

Ward, P.; Bierkens, M. F.; Bouwman, A.; Diaz Loaiza, A.; Eilander, D.; Englhardt, J.; Erkens, G.; Hofste, R.; Iceland, C.; Willem, L.; Luo, T.; Muis, S.; Scussolini, P.; Sutanudjaja, E.; Van Beek, L. P.; Van Bemmel, B.; Van Huijstee, J.; Van Wesenbeeck, B.; Vatvani, D.; Verlaan, M.; Winsemius, H.

2016-12-01

The economic losses associated with flooding are huge and rising. As a result, there is increasing attention for strategic flood risk assessments at the global scale. In response, the last few years have seen a large growth in the number of global flood models. At the same time, users and practitioners require flood risk information in a format that is easy to use, understandable, transparent, and actionable. In response, we have developed the Aqueduct Global Flood Analyzer (wri.org/floods). The Analyzer is a free, online, easy to use, tool for assessing global river flood risk at the scale of countries, states, and river basins, using data generated by the state of the art GLOFRIS global flood risk model. The Analyzer allows users to assess flood risk on-the-fly in terms of expected annual urban damage, and expected annual population and GDP affected by floods. Analyses can be carried out for current conditions and under future scenarios of climate change and socioeconomic development. We will demonstrate the tool, and discuss several of its applications in practice. In the past 15 months, the tool has been visited and used by more than 12,000 unique users from almost every country, including many users from the World Bank, Pacific Disaster Center, Red Cross Climate Centre, as well as many journalists from major international news outlets. Use cases will be presented from these user communities. We will also present ongoing research to improve the user functionality of the tool in the coming year. This includes the inclusion of coastal flood risk, assessing the costs and benefits of adaptation, and assessing the impacts of land subsidence and urban extension on risk.

The pattern of spatial flood disaster region in DKI Jakarta

NASA Astrophysics Data System (ADS)

Tambunan, M. P.

2017-02-01

The study of disaster flood area was conducted in DKI Jakarta Province, Indonesia. The aim of this research is: to study the spatial distribution of potential and actual of flood area The flood was studied from the geographic point of view using spatial approach, while the study of the location, the distribution, the depth and the duration of flooding was conducted using geomorphologic approach and emphasize on the detailed landform unit as analysis unit. In this study the landforms in DKI Jakarta have been a diversity, as well as spatial and temporal pattern of the actual and potential flood area. Landform at DKI Jakarta has been largely used as built up area for settlement and it facilities, thus affecting the distribution pattern of flooding area. The collection of the physical condition of landform in DKI Jakarta data prone were conducted through interpretation of the topographic map / RBI map and geological map. The flood data were obtained by survey and secondary data from Kimpraswil (Public Work) of DKI Jakarta Province for 3 years (1996, 2002, and 2007). Data of rainfall were obtained from BMKG and land use data were obtained from BPN DKI Jakarta. The analysis of the causal factors and distribution of flooding was made spatially and temporally using geographic information system. This study used survey method with a pragmatic approach. In this study landform as result from the analytical survey was settlement land use as result the synthetic survey. The primary data consist of landform, and the flood characteristic obtained by survey. The samples were using purposive sampling. Landform map was composed by relief, structure and material stone, and process data Landform map was overlay with flood map the flood prone area in DKI Jakarta Province in scale 1:50,000 to show. Descriptive analysis was used the spatial distribute of the flood prone area. The result of the study show that actual of flood prone area in the north, west and east of Jakarta lowland both in beach ridge, coastal alluvial plain, and alluvial plain; while the flood potential area on the slope is found flat and steep at alluvial fan, alluvial plain, beach ridge, and coastal alluvial plain in DKI Jakarta. Based on the result can be concluded that actual flood prone is not distributed on potential flood prone

A Vulnerability-Based, Bottom-up Assessment of Future Riverine Flood Risk Using a Modified Peaks-Over-Threshold Approach and a Physically Based Hydrologic Model

NASA Astrophysics Data System (ADS)

Knighton, James; Steinschneider, Scott; Walter, M. Todd

2017-12-01

There is a chronic disconnection among purely probabilistic flood frequency analysis of flood hazards, flood risks, and hydrological flood mechanisms, which hamper our ability to assess future flood impacts. We present a vulnerability-based approach to estimating riverine flood risk that accommodates a more direct linkage between decision-relevant metrics of risk and the dominant mechanisms that cause riverine flooding. We adapt the conventional peaks-over-threshold (POT) framework to be used with extreme precipitation from different climate processes and rainfall-runoff-based model output. We quantify the probability that at least one adverse hydrologic threshold, potentially defined by stakeholders, will be exceeded within the next N years. This approach allows us to consider flood risk as the summation of risk from separate atmospheric mechanisms, and supports a more direct mapping between hazards and societal outcomes. We perform this analysis within a bottom-up framework to consider the relevance and consequences of information, with varying levels of credibility, on changes to atmospheric patterns driving extreme precipitation events. We demonstrate our proposed approach using a case study for Fall Creek in Ithaca, NY, USA, where we estimate the risk of stakeholder-defined flood metrics from three dominant mechanisms: summer convection, tropical cyclones, and spring rain and snowmelt. Using downscaled climate projections, we determine how flood risk associated with a subset of mechanisms may change in the future, and the resultant shift to annual flood risk. The flood risk approach we propose can provide powerful new insights into future flood threats.

Nonstationary frequency analysis for the trivariate flood series of the Weihe River

NASA Astrophysics Data System (ADS)

Jiang, Cong; Xiong, Lihua

2016-04-01

Some intensive human activities such as water-soil conservation can significantly alter the natural hydrological processes of rivers. In this study, the effect of the water-soil conservation on the trivariate flood series from the Weihe River located in the Northwest China is investigated. The annual maxima daily discharge, annual maxima 3-day flood volume and annual maxima 5-day flood volume are chosen as the study data and used to compose the trivariate flood series. The nonstationarities in both the individual univariate flood series and the corresponding antecedent precipitation series generating the flood events are examined by the Mann-Kendall trend test. It is found that all individual univariate flood series present significant decreasing trend, while the antecedent precipitation series can be treated as stationary. It indicates that the increase of the water-soil conservation land area has altered the rainfall-runoff relationship of the Weihe basin, and induced the nonstationarities in the three individual univariate flood series. The time-varying moments model based on the Pearson type III distribution is applied to capture the nonstationarities in the flood frequency distribution with the water-soil conservation land area introduced as the explanatory variable of the flood distribution parameters. Based on the analysis for each individual univariate flood series, the dependence structure among the three univariate flood series are investigated by the time-varying copula model also with the water-soil conservation land area as the explanatory variable of copula parameters. The results indicate that the dependence among the trivariate flood series is enhanced by the increase of water-soil conservation land area.

Formation and evolution of valley-bottom and channel features, Lower Deschutes River, Oregon

USGS Publications Warehouse

Curran, Janet H.; O'Conner, Jim E.; O'Conner, Jim E.; Grant, Gordon E.

2003-01-01

Primary geologic and geomorphic processes that formed valley-bottom and channel features downstream from the Pelton-Round Butte dam complex are inferred from a canyon-long analysis of feature morphology, composition, location, and spatial distribution. Major controls on valley-bottom morphology are regional tectonics, large landslides, and outsized floods (floods with return periods greater than 1000 yrs), which include the late Holocene Outhouse Flood and several Quaternary landslide dam failures. Floods with a return period on the order of 100 yrs, including historical floods in 1996, 1964, and 1861, contribute to fan building and flood plain formation only within the resistant framework established by the major controls. Key processes in the formation of channel features, in particular the 153 islands and 23 large rapids, include long-term bedrock erosion, outsized floods, and century-scale floods. Historical analysis of channel conditions since 1911 indicates that the largest islands, which are cored by outsized-flood deposits, locally control channel location, although their margins are substantially modified during annual- to century-scale floods. Islands cored by bedrock have changed little. Islands formed by annual- to century-scale floods are more susceptible to dynamic interactions between tributary sediment inputs, mainstem flow hydraulics, and perhaps riparian vegetation. Temporal patterns of island change in response to the sequence of 20th century flooding indicate that many islands accreted sediment during annual- to decadal-scale floods, but eroded during larger century-scale floods. There is, however, no clear trend of long-term changes in patterns of island growth, movement, or erosion either spatially or temporally within the lower Deschutes River.

Gender, age and circumstances analysis of flood and landslide fatalities in Italy.

PubMed

Salvati, Paola; Petrucci, Olga; Rossi, Mauro; Bianchi, Cinzia; Pasqua, Aurora A; Guzzetti, Fausto

2018-01-01

Floods and landslides are frequent and destructive geo-hydrological hazards that cause harm to people every year. We analysed data on 1292 landslide and 771 flood fatalities that occurred in Italy in the 50-year period 1965-2014, to determine the dependence of the fatalities on gender and age and the circumstances of death by type of hazard. The multinomial probability mass function of the expected fatalities by gender and age, as reported by national census data, were estimated and compared with the observed landslide and flood fatalities. We identified the age categories over or under represented when the observed fatalities were respectively higher or lower than the modelled expected deaths. We found that in Italy males are more vulnerable to floods and landslides for most of the age categories. Apart from children, males are over-represented up to the age of 89 for floods and up to 79 for landslides, whereas females are under-represented up to the age of 59 for floods and landslides, and over-represented above 70 for floods and between 60 and 79 for landslides. To consider the demographic and socio-cultural changes over time, we performed a temporal analysis splitting the record into two non-overlapping subsets of 25year each. The analysis demonstrated that the over-representation of males compared to the females, both for landslide and flood is statistically significant and does not vary in time, indicating a different propensity towards the risk taking and a different degree of exposure between males and females. Analysis of the data allowed to identify the common circumstances of death. Landslides fatalities occurred frequently indoor, whereas the majority of the flood fatalities occurred outdoor, outlining the different dynamics of the hazards. Floods killed numerous people along roads and drivers or passengers travelling in vehicles. We expect that the results of this work will be helpful to design recommendations for self-protecting actions, and proactive policies that can contribute to reduce the human toll of floods and landslides in Italy, and elsewhere. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

An Approach to Assessing Flood Risk in Low-lying Paddy Areas of Japan considering Economic Damage on Rice

NASA Astrophysics Data System (ADS)

Minakawa, H.; Masumoto, T.

2013-12-01

Hiroki Minakawa, Takao Masumoto National Institute for Rural Engineering (NIRE), NARO, Japan Flooding is one type of nature disaster, and is caused by heavy rainfall events. In the future, the risk of flooding is predicted to increase due to global climate change. Immediate measures such as strengthening drainage capacity are needed to minimize the damage caused by more frequent flooding, so a quantitative evaluation method of flood risks is needed to discuss countermeasure against these problems. At the same time, rice is an important crop for food production in Japan. However, paddy fields are often damaged by flooding because they are principally spread in lower part of the basin. Therefore, it is also important to assess the damages to paddy fields. This study discusses a method for evaluating a relationship between the risk of flood damage and the scale of heavy rainfall. We also developed a method of estimating the economic effect of a reduction in rice yield by flooding. First, we developed a drainage analysis model that incorporates kinematic and diffusive runoff models for calculating water level in channels and paddies. Next, heavy rainfall data for drainage analyses were generated by using a diurnal rainfall pattern generator. The generator can create hourly data of heavy rainfall, and internal pattern of them is different each. These data were input to the drainage model to estimate flood risk. Simultaneously, we tried to clarify economic losses of a rice yields caused by flooding. Here, the reduction scale in rice yield which shows relations between flooding situation (e.g. water level, duration of submersion etc.) and damage of rice is available to calculate reduction of rice yield. In this study, we created new reduction scales through a pseudo-flooding experiment under real inundation conditions. The methodology of the experiment was as follow: We chose the popular Japanese rice cultivar Koshihikari for this experiment. An experimental arena was constructed in a rice paddy plot, which consisted of two zones, one in which the rice was cultivated as usual with normal water levels, and a flood zone, which was used for submerging rice plants. The flood zone, which was designed to reproduce actual flood disaster conditions in paddy fields, can be filled with water to a depth of 0.3, 0.6 or 0.9 m above ground level, and is divided into two plots, a clean water part and a turbid water part. Thus, the experimental conditions can vary according to 1) the development stage of rice, 2) complete or incomplete submersion, 3) clean or turbid water, and 4) duration of submergence. Finally, the reduction scales were formulated by using the resultant data and it was found that rice is most sensitive to damage during the development stage. Flood risk was evaluated by using calculated water level on each paddy. Here, the averaged duration of inundation to a depth of more than 0.3 m was used as the criteria for flood occurrence. The results indicated that the duration increased with larger heavy rainfall amounts. Furthermore, the damage to rice was predicted to increase especially in low-lying paddy fields. Mitigation measures, such as revising drainage planning and/or changing design standards for the capacity of drainage pumps may be necessary in the future.

U.S./China Bilateral Symposium on Extraordinary Floods

NASA Astrophysics Data System (ADS)

Kirby, W.

Accurate appraisal of the risk of extreme floods has long been of concern to hydrologists and water resources managers in both the United States and China. In order to exchange information, assess current developments, and discuss further needs in extreme flood analysis, the U.S. Geological Survey (USGS) and the Bureau of Hydrology of the Ministry of Water Resources and Electric Power of the People's Republic of China (PRC) held the Bilateral Symposium on the Analysis of Extraordinary Flood Events, October 14-18, 1985, in Nanjing, China. Co-convenors of the symposium were Marshall E. Moss (USGS) and Hua Shiqian (Nanjing Research Institute of Hydrology). Liang Ruiju (East China Technical University of Water Resources) was executive secretary of the organizing committee. Participants included 23 U.S. delegates, 36 Chinese delegates, and five guests from other countries. Of the U.S. delegates, 13 were from federal agencies, seven were from universities, and three were private consultants. The U.S. National Science Foundation gave financial support to the nonfederal U.S. delegates. Major topics covered in the 52 papers presented included detection of historical floods and evaluation of the uncertainties in their peak discharges and times of occurrence,frequency analysis and design flood determination in the presence of extraordinary floods and historic floods, anduse of storm data in determining design storms and design floods, The symposium was followed by a 6-day study tour in central China, during which laboratories, field activities, and offices of various water resources agencies were visited and sites of documented historic floods on the Yangtze River and its tributaries were examined.

The large-scale distribution and internal geometry of the fall 2000 Po River flood deposit: Evidence from digital X-radiography

USGS Publications Warehouse

Wheatcroft, R.A.; Stevens, A.W.; Hunt, L.M.; Milligan, T.G.

2006-01-01

Event-response coring on the Po River prodelta (northern Adriatic Sea) coupled with shipboard digital X-radiography, resistivity profiling, and grain-size analyses permitted documentation of the initial distribution and physical properties of the October 2000 flood deposit. The digital X-radiography system comprises a constant-potential X-ray source and an amorphous silicon imager with an active area of 29??42 cm and 12-bit depth resolution. Objective image segmentation algorithms based on bulk density (brightness), layer contacts (edge detection) and small-scale texture (fabric) were used to identify the flood deposit. Results indicate that the deposit formed in water depths of 6-29 m immediately adjacent to the three main distributary mouths of the Po (Pila, Tolle and Gnocca/Goro). Maximal thickness was 36 cm at a 20-m site off the main mouth (Pila), but many other sites hadthicknesses >20 cm. The Po flood deposit has a complex internal stratigraphy, with multiple layers, a diverse suite of physical sedimentary structures (e.g., laminations, ripple cross bedding, lenticular bedding, soft-sediment deformation structures), and dramatic changes in grain size that imply rapid deposition and fluctuations in energy during emplacement. Based on the flood deposit volume and well-constrained measurements of deposit bulk density the mass of the flood deposit was estimated to be 16??109 kg, which is about two-thirds of the estimated suspended sediment load delivered by the river during the event. The locus of deposition, overall thickness, and stratigraphic complexity of the flood deposit can best be explained by the relatively long sediment throughput times of the Po River, whereby sediment is delivered to the ocean during a range of conditions (i.e., the storm responsible for the precipitation is long gone), the majority of which are reflective of the fair-weather condition. Sediment is therefore deposited proximal to the river mouths, where it can form thick, but stratigraphically complex deposits. In contrast, floods of small rivers such as the Eel (northern California) are coupled to storm conditions, which lead to high levels of sediment dispersion. ?? 2006 Elsevier Ltd. All rights reserved.

Statistical Development of Flood Frequency and Magnitude Equations for the Cosumnes and Mokelumne River Drainage Basins, Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Burns, R. G.; Meyer, R. W.; Cornwell, K.

2003-12-01

In-basin statistical relations allow for development of regional flood frequency and magnitude equations in the Cosumnes River and Mokelumne River drainage basins. Current equations were derived from data collected through 1975, and do not reflect newer data with some significant flooding. Physical basin characteristics (area, mean basin elevation, slope of longest reach, and mean annual precipitation) were correlated against predicted flood discharges for each of the 5, 10, 25, 50, 100, 200, and 500-year recurrence intervals in a multivariate analysis. Predicted maximum instantaneous flood discharges were determined using the PEAKFQ program with default settings, for 24 stream gages within the study area presumed not affected by flow management practices. For numerical comparisons, GIS-based methods using Spatial Analyst and the Arc Hydro Tools extension were applied to derive physical basin characteristics as predictor variables from a 30m digital elevation model (DEM) and a mean annual precipitation raster (PRISM). In a bivariate analysis, examination of Pearson correlation coefficients, F-statistic, and t & p thresholds show good correlation between area and flood discharges. Similar analyses show poor correlation for mean basin elevation, slope and precipitation, with flood discharge. Bivariate analysis suggests slope may not be an appropriate predictor term for use in the multivariate analysis. Precipitation and elevation correlate very well, demonstrating possible orographic effects. From the multivariate analysis, less than 6% of the variability in the correlation is not explained for flood recurrences up to 25 years. Longer term predictions up to 500 years accrue greater uncertainty with as much as 15% of the variability in the correlation left unexplained.

Towards a global flood detection system using social media

NASA Astrophysics Data System (ADS)

de Bruijn, Jens; de Moel, Hans; Jongman, Brenden; Aerts, Jeroen

2017-04-01

It is widely recognized that an early warning is critical in improving international disaster response. Analysis of social media in real-time can provide valuable information about an event or help to detect unexpected events. For successful and reliable detection systems that work globally, it is important that sufficient data is available and that the algorithm works both in data-rich and data-poor environments. In this study, both a new geotagging system and multi-level event detection system for flood hazards was developed using Twitter data. Geotagging algorithms that regard one tweet as a single document are well-studied. However, no algorithms exist that combine several sequential tweets mentioning keywords regarding a specific event type. Within the time frame of an event, multiple users use event related keywords that refer to the same place name. This notion allows us to treat several sequential tweets posted in the last 24 hours as one document. For all these tweets, we collect a series of spatial indicators given in the tweet metadata and extract additional topological indicators from the text. Using these indicators, we can reduce ambiguity and thus better estimate what locations are tweeted about. Using these localized tweets, Bayesian change-point analysis is used to find significant increases of tweets mentioning countries, provinces or towns. In data-poor environments detection of events on a country level is possible, while in other, data-rich, environments detection on a city level is achieved. Additionally, on a city-level we analyse the spatial dependence of mentioned places. If multiple places within a limited spatial extent are mentioned, detection confidence increases. We run the algorithm using 2 years of Twitter data with flood related keywords in 13 major languages and validate against a flood event database. We find that the geotagging algorithm yields significantly more data than previously developed algorithms and successfully deals with ambiguous place names. In addition, we show that our detection system can both quickly and reliably detect floods, even in countries where data is scarce, while achieving high detail in countries where more data is available.

Analysis of Non-Tropical Cyclone Induced Flood Events over South East Asia: Investigating Flood Frequency and Extremes in the Philippines

NASA Astrophysics Data System (ADS)

Marcella, M. P.; CHEN, C.; Senarath, S. U.

2013-12-01

Much work has been completed in analyzing Southeast Asia's tropical cyclone climatology and the associated flooding throughout the region. Although, an active and strong monsoon season also brings major flooding across the Philippines resulting in the loss of lives and significant economic impacts, only a limited amount of research work has been conducted to investigate the frequency and flood loss estimates of these non-tropical cyclone (TC) storms. In this study, using the TRMM 3-hourly rainfall product, tropical cyclone rainfall is removed to construct a non-TC rainfall climatology across the region. Given this data, stochastically generated rainfall that is both spatially and temporally correlated across the country is created to generate a longer historically-based record of non-TC precipitation. After defining the rainfall criteria that constitutes a flood event based on observed floods and TRMM data, this event definition is applied to the stochastic catalog of rainfall to determine flood events. Subsequently, a thorough analysis of non-TC flood extremes, frequency, and distribution is completed for the country of the Philippines. As a result, the above methodology and datasets provide a unique opportunity to further study flood occurrences and their extremes across most of South East Asia.

Spatial patterns of frequent floods in Switzerland

NASA Astrophysics Data System (ADS)

Schneeberger, Klaus; Rössler, Ole; Weingartner, Rolf

2017-04-01

Information about the spatial characteristics of high and extreme streamflow is often needed for an accurate analysis of flood risk and effective co-ordination of flood related activities, such as flood defence planning. In this study we analyse the spatial dependence of frequent floods in Switzerland across different scales. Firstly, we determine the average length of high and extreme flow events for 56 runoff time series of Swiss rivers. Secondly, a dependence measure expressing the probability that streamflow peaks are as high as peaks at a conditional site is used to describe and map the spatial extend of joint occurrence of frequent floods across Switzerland. Thirdly, we apply a cluster analysis to identify groups of sites that are likely to react similarly in terms of joint occurrence of high flow events. The results indicate that a time interval with a length of 3 days seems to be most appropriate to characterise the average length of high streamflow events across spatial scales. In the main Swiss basins, high and extreme streamflows were found to be asymptotically independent. In contrast, at the meso-scale distinct flood regions, which react similarly in terms of occurrence of frequent flood, were found. The knowledge about these regions can help to optimise flood defence planning or to estimate regional flood risk properly.

Accounting for Atmospheric Rivers in the Flood Frequency Estimation in the Western United States

NASA Astrophysics Data System (ADS)

Barth, N. A.; Villarini, G.; White, K. D.

2016-12-01

The Bulletin 17B framework assumes that the observed annual peak flow data included in a flood frequency analysis are a "representative time sample of random homogeneous events." However, flood frequency analysis over the western United States is complicated by annual peak flow records that frequently contain flows generated from distinctly different flood generating mechanisms. Among the different flood generating mechanisms, atmospheric rivers (ARs) are responsible for large, regional scale floods. USGS streamgaging stations in the central Columbia River Basin in the Pacific Northwest, the Sierra Nevada, the central and southern California coast, and central Arizona show a mixture of 30-70% AR-generated flood peaks among the complete period of record. It is relatively common for the annual peaks fitted to the log-Pearson Type III distribution in these regions to show sharp breaks in the slope or a curve that reverses direction, pointing to the presence of different flood generating mechanisms. Following the recommendation by B17B to develop separate frequency curves when different flood agents can be identified, we will perform flood frequency analyses accounting for the role played by ARs. We will compare and contrast the results obtained by treating all annual maximum discharge values as generated from a single population against those from a mixed population analyses.

Paleoflood Data, Extreme Floods and Frequency: Data and Models for Dam Safety Risk Scenarios

NASA Astrophysics Data System (ADS)

England, J. F.; Godaire, J.; Klinger, R.

2007-12-01

Extreme floods and probability estimates are crucial components in dam safety risk analysis and scenarios for water-resources decision making. The field-based collection of paleoflood data provides needed information on the magnitude and probability of extreme floods at locations of interest in a watershed or region. The stratigraphic record present along streams in the form of terrace and floodplain deposits represent direct indicators of the magnitude of large floods on a river, and may provide 10 to 100 times longer records than conventional stream gaging records of large floods. Paleoflood data is combined with gage and historical streamflow estimates to gain insights to flood frequency scaling, model extrapolations and uncertainty, and provide input scenarios to risk analysis event trees. We illustrate current data collection and flood frequency modeling approaches via case studies in the western United States, including the American River in California and the Arkansas River in Colorado. These studies demonstrate the integration of applied field geology, hydraulics, and surface-water hydrology. Results from these studies illustrate the gains in information content on extreme floods, provide data- based means to separate flood generation processes, guide flood frequency model extrapolations, and reduce uncertainties. These data and scenarios strongly influence water resources management decisions.

Development of a model-based flood emergency management system in Yujiang River Basin, South China

NASA Astrophysics Data System (ADS)

Zeng, Yong; Cai, Yanpeng; Jia, Peng; Mao, Jiansu

2014-06-01

Flooding is the most frequent disaster in China. It affects people's lives and properties, causing considerable economic loss. Flood forecast and operation of reservoirs are important in flood emergency management. Although great progress has been achieved in flood forecast and reservoir operation through using computer, network technology, and geographic information system technology in China, the prediction accuracy of models are not satisfactory due to the unavailability of real-time monitoring data. Also, real-time flood control scenario analysis is not effective in many regions and can seldom provide online decision support function. In this research, a decision support system for real-time flood forecasting in Yujiang River Basin, South China (DSS-YRB) is introduced in this paper. This system is based on hydrological and hydraulic mathematical models. The conceptual framework and detailed components of the proposed DSS-YRB is illustrated, which employs real-time rainfall data conversion, model-driven hydrologic forecasting, model calibration, data assimilation methods, and reservoir operational scenario analysis. Multi-tiered architecture offers great flexibility, portability, reusability, and reliability. The applied case study results show the development and application of a decision support system for real-time flood forecasting and operation is beneficial for flood control.

Mapping Infected Area after a Flash-Flooding Storm Using Multi Criteria Analysis and Spectral Indices

NASA Astrophysics Data System (ADS)

Al-Akad, S.; Akensous, Y.; Hakdaoui, M.

2017-11-01

This research article is summarize the applications of remote sensing and GIS to study the urban floods risk in Al Mukalla. Satellite acquisition of a flood event on October 2015 in Al Mukalla (Yemen) by using flood risk mapping techniques illustrate the potential risk present in this city. Satellite images (The Landsat and DEM images data were atmospherically corrected, radiometric corrected, and geometric and topographic distortions rectified.) are used for flood risk mapping to afford a hazard (vulnerability) map. This map is provided by applying image-processing techniques and using geographic information system (GIS) environment also the application of NDVI, NDWI index, and a method to estimate the flood-hazard areas. Four factors were considered in order to estimate the spatial distribution of the hazardous areas: flow accumulation, slope, land use, geology and elevation. The multi-criteria analysis, allowing to deal with vulnerability to flooding, as well as mapping areas at the risk of flooding of the city Al Mukalla. The main object of this research is to provide a simple and rapid method to reduce and manage the risks caused by flood in Yemen by take as example the city of Al Mukalla.

Living with floods in the Jamuna floodplain (Bangladesh): fight or flight? Technological and societal responses

NASA Astrophysics Data System (ADS)

Ruknul Ferdous, Md; Wesselink, Anna; Brandimarte, Luigia; Slager, Kymo; Mynett, Arthur; Zwarteveen, Margreet

2017-04-01

Building onto the general theory introduced by Di Baldassarre, this paper uses a socio-hydrological approach to describe human-flood interactions in the Jamuna floodplain, Bangladesh. In this vast space (a braided river bed of 6-16 km; floodplains up to 50 km wide) the differences between land and water are temporary and shifting. Government flood defence structures were constructed on the west bank only, while community initiatives exist on the east bank. As a result, there are several kinds of socio-hydrological spaces along, but also in the river, with different livelihoods and flood characteristics. This variety gives rise to co-existence of 'living with floods' and 'fighting floods' approaches. The analysis is based on recent fieldwork, in which information on historical and current livelihoods, migration and the floodplain system was collected at household level. Our analysis enables us to tentatively confirm the levee effect described by Di Baldassarre et al. (2013); however, his hypothesis that people move away from unprotected floodplains is only true to some extent. Adaptation in Bangladesh means first of all literally 'living with floods': being flooded with greater or lesser frequency. Key words: Bangladesh; Jamuna River; river flooding; socio-hydrological dynamics

Remote collection and analysis of witness reports on flash floods

NASA Astrophysics Data System (ADS)

Gourley, J. J.; Erlingis, J. M.; Smith, T. M.; Ortega, K. L.; Hong, Y.

2010-11-01

SummaryTypically, flash floods are studied ex post facto in response to a major impact event. A complement to field investigations is developing a detailed database of flash flood events, including minor events and null reports (i.e., where heavy rain occurred but there was no flash flooding), based on public survey questions conducted in near-real time. The Severe hazards analysis and verification experiment (SHAVE) has been in operation at the National Severe Storms Laboratory (NSSL) in Norman, OK, USA during the summers since 2006. The experiment employs undergraduate students to analyse real-time products from weather radars, target specific regions within the conterminous US, and poll public residences and businesses regarding the occurrence and severity of hail, wind, tornadoes, and now flash floods. In addition to providing a rich learning experience for students, SHAVE has also been successful in creating high-resolution datasets of severe hazards used for algorithm and model verification. This paper describes the criteria used to initiate the flash flood survey, the specific questions asked and information entered to the database, and then provides an analysis of results for flash flood data collected during the summer of 2008. It is envisioned that specific details provided by the SHAVE flash flood observation database will complement databases collected by operational agencies (i.e., US National Weather Service Storm Data reports) and thus lead to better tools to predict the likelihood of flash floods and ultimately reduce their impacts on society.

Reducing uncertainty with flood frequency analysis: The contribution of paleoflood and historical flood information

NASA Astrophysics Data System (ADS)

Lam, Daryl; Thompson, Chris; Croke, Jacky; Sharma, Ashneel; Macklin, Mark

2017-03-01

Using a combination of stream gauge, historical, and paleoflood records to extend extreme flood records has proven to be useful in improving flood frequency analysis (FFA). The approach has typically been applied in localities with long historical records and/or suitable river settings for paleoflood reconstruction from slack-water deposits (SWDs). However, many regions around the world have neither extensive historical information nor bedrock gorges suitable for SWDs preservation and paleoflood reconstruction. This study from subtropical Australia demonstrates that confined, semialluvial channels such as macrochannels provide relatively stable boundaries over the 1000-2000 year time period and the preserved SWDs enabled paleoflood reconstruction and their incorporation into FFA. FFA for three sites in subtropical Australia with the integration of historical and paleoflood data using Bayesian Inference methods showed a significant reduction in uncertainty associated with the estimated discharge of a flood quantile. Uncertainty associated with estimated discharge for the 1% Annual Exceedance Probability (AEP) flood is reduced by more than 50%. In addition, sensitivity analysis of possible within-channel boundary changes shows that FFA is not significantly affected by any associated changes in channel capacity. Therefore, a greater range of channel types may be used for reliable paleoflood reconstruction by evaluating the stability of inset alluvial units, thereby increasing the quantity of temporal data available for FFA. The reduction in uncertainty, particularly in the prediction of the ≤1% AEP design flood, will improve flood risk planning and management in regions with limited temporal flood data.

Quantifying riverine and storm-surge flood risk by single-family residence: application to Texas.

PubMed

Czajkowski, Jeffrey; Kunreuther, Howard; Michel-Kerjan, Erwann

2013-12-01

The development of catastrophe models in recent years allows for assessment of the flood hazard much more effectively than when the federally run National Flood Insurance Program (NFIP) was created in 1968. We propose and then demonstrate a methodological approach to determine pure premiums based on the entire distribution of possible flood events. We apply hazard, exposure, and vulnerability analyses to a sample of 300,000 single-family residences in two counties in Texas (Travis and Galveston) using state-of-the-art flood catastrophe models. Even in zones of similar flood risk classification by FEMA there is substantial variation in exposure between coastal and inland flood risk. For instance, homes in the designated moderate-risk X500/B zones in Galveston are exposed to a flood risk on average 2.5 times greater than residences in X500/B zones in Travis. The results also show very similar average annual loss (corrected for exposure) for a number of residences despite their being in different FEMA flood zones. We also find significant storm-surge exposure outside of the FEMA designated storm-surge risk zones. Taken together these findings highlight the importance of a microanalysis of flood exposure. The process of aggregating risk at a flood zone level-as currently undertaken by FEMA-provides a false sense of uniformity. As our analysis indicates, the technology to delineate the flood risks exists today. © 2013 Society for Risk Analysis.

A coupled hydrological-hydraulic flood inundation model calibrated using post-event measurements and integrated uncertainty analysis in a poorly gauged Mediterranean basin

NASA Astrophysics Data System (ADS)

Hdeib, Rouya; Abdallah, Chadi; Moussa, Roger; Colin, Francois

2017-04-01

Developing flood inundation maps of defined exceedance probabilities is required to provide information on the flood hazard and the associated risk. A methodology has been developed to model flood inundation in poorly gauged basins, where reliable information on the hydrological characteristics of floods are uncertain and partially captured by the traditional rain-gauge networks. Flood inundation is performed through coupling a hydrological rainfall-runoff (RR) model (HEC-HMS) with a hydraulic model (HEC-RAS). The RR model is calibrated against the January 2013 flood event in the Awali River basin, Lebanon (300 km2), whose flood peak discharge was estimated by post-event measurements. The resulting flows of the RR model are defined as boundary conditions of the hydraulic model, which is run to generate the corresponding water surface profiles and calibrated against 20 post-event surveyed cross sections after the January-2013 flood event. An uncertainty analysis is performed to assess the results of the models. Consequently, the coupled flood inundation model is simulated with design storms and flood inundation maps are generated of defined exceedance probabilities. The peak discharges estimated by the simulated RR model were in close agreement with the results from different empirical and statistical methods. This methodology can be extended to other poorly gauged basins facing common stage-gauge failure or characterized by floods with a stage exceeding the gauge measurement level, or higher than that defined by the rating curve.

Effect of Sampling Period on Flood Frequency Distributions in the Susquehanna Basin

NASA Astrophysics Data System (ADS)

Kargar, M.; Beighley, R. E.

2010-12-01

Flooding is a devastating natural hazard that claims many human lives and significantly impact regional economies each year. Given the magnitude of flooding impacts, significant resources are dedicated to the development of forecasting models for early warning and evacuation planning, construction of flood defenses (levees/dams) to limit flooding, and the design of civil infrastructure (bridges, culverts, storm sewers) to convey flood flows without failing. In all these cases, it is particularly important to understand the potential flooding risk in terms of both recurrence interval (i.e., return period) and magnitude. Flood frequency analysis (FFA) is a form of risk analysis used to extrapolate the return periods of floods beyond the gauged record. The technique involves using observed annual peak flow discharge data to calculate statistical information such as mean values, standard deviations, skewness, and recurrence intervals. Since discharge data for most catchments have been collected for periods of time less than 100 years, the estimation of the design discharge requires a degree of extrapolation. This study focuses on the assessment and modifications of flood frequency based discharges for sites with limited sampling periods. Here, limited sampling period is intended to capture two issues: (1) limited number of observations to adequately capture the flood frequency signal (i.e., minimum number of annual peaks needed) and (2) climate variability (i.e., sampling period contains primarily “wet” or “dry” periods only). Total of 34 gauges (more than 70 years of data) spread throughout the Susquehanna River basin (71,000 sq km) were used to investigate the impact of sampling period on flood frequency distributions. Data subsets ranging from 10 years to the total number of years available were created from the data for each gauging station. To estimate the flood frequency, the Log Pearson Type III distribution was fit to the logarithms of instantaneous annual peak flows following Bulletin 17B guidelines of the U.S. Interagency Advisory Committee on Water Data. The resulting flood frequencies from these subsets were compared to the results from the entire record at each gauge. Based on the analysis, the minimum number of years required to obtain a reasonable flood frequency distribution was determined for each gauge. In addition, a method to adjust flood frequency distribution at a given gauging station with limited data based on other locations with longer periods of records was developed.

Investigation of trends in flooding in the Tug Fork basin of Kentucky, Virginia, and West Virginia

USGS Publications Warehouse

Hirsch, Robert M.; Scott, Arthur G.; Wyant, Timothy

1982-01-01

Statistical analysis indicates that the average size of annual-flood peaks of the Tug Fork (Ky., Va., and W. Va.) has been increasing. However, additional statistical analysis does not indicate that the flood levels that were exceeded typically once or twice a year in the period 1947-79 are any more likely to be exceeded now than in 1947. Possible trends in streamchannel size also are investigated at three locations. No discernible trends in channel size are noted. Further statistical analysis of the trend in the size of annual-flood peaks shows that much of the annual variation is related to local rainfall and to the 'natural' hydrologic response in a relatively undisturbed subbasin. However, some statistical indication of trend persists after accounting for these natural factors, though it is of borderline statistical significance. Further study in the basin may relate flood magnitudes to both rainfall and to land use.

75 FR 7522 - United States Section; Notice of Availability of the Final Environmental Impact Statement, Flood...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-19

... Final EIS: Biological resources, cultural resources, water resources, land use, socioeconomic resources... INTERNATIONAL BOUNDARY AND WATER COMMISSION, UNITED STATES AND MEXICO United States Section..., International Boundary and Water Commission (USIBWC). ACTION: Notice of Availability of Final Environmental...

Effects of changes along the risk chain on flood risk

NASA Astrophysics Data System (ADS)

Duha Metin, Ayse; Apel, Heiko; Viet Dung, Nguyen; Guse, Björn; Kreibich, Heidi; Schröter, Kai; Vorogushyn, Sergiy; Merz, Bruno

2017-04-01

Interactions of hydrological and socio-economic factors shape flood disaster risk. For this reason, assessment of flood risk ideally takes into account the whole flood risk chain from atmospheric processes, through the catchment and river system processes to the damage mechanisms in the affected areas. Since very different processes at various scales are interacting along the flood risk, the impact of the single components is rather unclear. However for flood risk management, it is required to know the controlling factor of flood damages. The present study, using the flood-prone Mulde catchment in Germany, discusses the sensitivity of flood risk to disturbances along the risk chain: How do disturbances propagate through the risk chain? How do different disturbances combine or conflict and affect flood risk? In this sensitivity analysis, the five components of the flood risk change are included. These are climate, catchment, river system, exposure and vulnerability. A model framework representing the complete risk chain is combined with observational data to understand how the sensitivities evolve along the risk chain by considering three plausible change scenarios for each of five components. The flood risk is calculated by using the Regional Flood Model (RFM) which is based on a continuous simulation approach, including rainfall-runoff, 1D river network, 2D hinterland inundation and damage estimation models. The sensitivity analysis covers more than 240 scenarios with different combinations of the five components. It is investigated how changes in different components affect risk indicators, such as the risk curve and expected annual damage (EAD). In conclusion, it seems that changes in exposure and vulnerability seem to outweigh changes in hazard.

Flood Hazard Mapping by Applying Fuzzy TOPSIS Method

NASA Astrophysics Data System (ADS)

Han, K. Y.; Lee, J. Y.; Keum, H.; Kim, B. J.; Kim, T. H.

2017-12-01

There are lots of technical methods to integrate various factors for flood hazard mapping. The purpose of this study is to suggest the methodology of integrated flood hazard mapping using MCDM(Multi Criteria Decision Making). MCDM problems involve a set of alternatives that are evaluated on the basis of conflicting and incommensurate criteria. In this study, to apply MCDM to assessing flood risk, maximum flood depth, maximum velocity, and maximum travel time are considered as criterion, and each applied elements are considered as alternatives. The scheme to find the efficient alternative closest to a ideal value is appropriate way to assess flood risk of a lot of element units(alternatives) based on various flood indices. Therefore, TOPSIS which is most commonly used MCDM scheme is adopted to create flood hazard map. The indices for flood hazard mapping(maximum flood depth, maximum velocity, and maximum travel time) have uncertainty concerning simulation results due to various values according to flood scenario and topographical condition. These kind of ambiguity of indices can cause uncertainty of flood hazard map. To consider ambiguity and uncertainty of criterion, fuzzy logic is introduced which is able to handle ambiguous expression. In this paper, we made Flood Hazard Map according to levee breach overflow using the Fuzzy TOPSIS Technique. We confirmed the areas where the highest grade of hazard was recorded through the drawn-up integrated flood hazard map, and then produced flood hazard map can be compared them with those indicated in the existing flood risk maps. Also, we expect that if we can apply the flood hazard map methodology suggested in this paper even to manufacturing the current flood risk maps, we will be able to make a new flood hazard map to even consider the priorities for hazard areas, including more varied and important information than ever before. Keywords : Flood hazard map; levee break analysis; 2D analysis; MCDM; Fuzzy TOPSIS Acknowlegement This research was supported by a grant (17AWMP-B079625-04) from Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

Framework for National Flood Risk Assessment for Canada

NASA Astrophysics Data System (ADS)

Elshorbagy, A. A.; Raja, B.; Lakhanpal, A.; Razavi, S.; Ceola, S.; Montanari, A.

2016-12-01

Worldwide, floods have been identified as a standout amongst the most widely recognized catastrophic events, resulting in the loss of life and property. These natural hazards cannot be avoided, but their consequences can certainly be reduced by having prior knowledge of their occurrence and impact. In the context of floods, the terms occurrence and impact are substituted by flood hazard and flood vulnerability, respectively, which collectively define the flood risk. There is a high need for identifying the flood-prone areas and to quantify the risk associated with them. The present study aims at delivering flood risk maps, which prioritize the potential flood risk areas in Canada. The methodology adopted in this study involves integrating various available spatial datasets such as nightlights satellite imagery, land use, population and the digital elevation model, to build a flexible framework for national flood risk assessment for Canada. The flood risk framework assists in identifying the flood-prone areas and evaluating the associated risk. All these spatial datasets were brought to a common GIS platform for flood risk analysis. The spatial datasets deliver the socioeconomic and topographical information that is required for evaluating the flood vulnerability and flood hazard, respectively. Nightlights have been investigated as a tool to be used as a proxy for the human activities to identify areas with regard to economic investment. However, other datasets, including existing flood protection measures, we added to identify a realistic flood assessment framework. Furthermore, the city of Calgary was used as an example to investigate the effect of using Digital Elevation Models (DEMs) of varying resolutions on risk maps. Along with this, the risk map for the city was further enhanced by including the population data to give a social dimension to the risk map. Flood protection measures play a major role by significantly reducing the flood risk of events with a specific return period. An analysis to update the risk maps when information on protection measures is available was carried out for the city of Winnipeg, Canada. The proposed framework is a promising approach to identify and prioritize flood-prone areas, which are in need of intervention or detailed studies.

The Advanced Rapid Imaging and Analysis (ARIA) Project: Status of SAR products for Earthquakes, Floods, Volcanoes and Groundwater-related Subsidence

NASA Astrophysics Data System (ADS)

Owen, S. E.; Yun, S. H.; Hua, H.; Agram, P. S.; Liu, Z.; Sacco, G. F.; Manipon, G.; Linick, J. P.; Fielding, E. J.; Lundgren, P.; Farr, T. G.; Webb, F.; Rosen, P. A.; Simons, M.

2017-12-01

The Advanced Rapid Imaging and Analysis (ARIA) project for Natural Hazards is focused on rapidly generating high-level geodetic imaging products and placing them in the hands of the solid earth science and local, national, and international natural hazard communities by providing science product generation, exploration, and delivery capabilities at an operational level. Space-based geodetic measurement techniques including Interferometric Synthetic Aperture Radar (InSAR), differential Global Positioning System, and SAR-based change detection have become critical additions to our toolset for understanding and mapping the damage and deformation caused by earthquakes, volcanic eruptions, floods, landslides, and groundwater extraction. Up until recently, processing of these data sets has been handcrafted for each study or event and has not generated products rapidly and reliably enough for response to natural disasters or for timely analysis of large data sets. The ARIA project, a joint venture co-sponsored by the California Institute of Technology and by NASA through the Jet Propulsion Laboratory, has been capturing the knowledge applied to these responses and building it into an automated infrastructure to generate imaging products in near real-time that can improve situational awareness for disaster response. In addition to supporting the growing science and hazard response communities, the ARIA project has developed the capabilities to provide automated imaging and analysis capabilities necessary to keep up with the influx of raw SAR data from geodetic imaging missions such as ESA's Sentinel-1A/B, now operating with repeat intervals as short as 6 days, and the upcoming NASA NISAR mission. We will present the progress and results we have made on automating the analysis of Sentinel-1A/B SAR data for hazard monitoring and response, with emphasis on recent developments and end user engagement in flood extent mapping and deformation time series for both volcano monitoring and mapping of groundwater-related subsidence

Modeling effectiveness of management practices for flood mitigation using GIS spatial analysis functions in Upper Cilliwung watershed

NASA Astrophysics Data System (ADS)

Darma Tarigan, Suria

2016-01-01

Flooding is caused by excessive rainfall flowing downstream as cumulative surface runoff. Flooding event is a result of complex interaction of natural system components such as rainfall events, land use, soil, topography and channel characteristics. Modeling flooding event as a result of interaction of those components is a central theme in watershed management. The model is usually used to test performance of various management practices in flood mitigation. There are various types of management practices for flood mitigation including vegetative and structural management practices. Existing hydrological model such as SWAT and HEC-HMS models have limitation to accommodate discrete management practices such as infiltration well, small farm reservoir, silt pits in its analysis due to the lumped structure of these models. Aim of this research is to use raster spatial analysis functions of Geo-Information System (RGIS-HM) to model flooding event in Ciliwung watershed and to simulate impact of discrete management practices on surface runoff reduction. The model was validated using flooding data event of Ciliwung watershed on 29 January 2004. The hourly hydrograph data and rainfall data were available during period of model validation. The model validation provided good result with Nash-Suthcliff efficiency of 0.8. We also compared the RGIS-HM with Netlogo Hydrological Model (NL-HM). The RGIS-HM has similar capability with NL-HM in simulating discrete management practices in watershed scale.

Merging information from multi-model flood projections in a hierarchical Bayesian framework

NASA Astrophysics Data System (ADS)

Le Vine, Nataliya

2016-04-01

Multi-model ensembles are becoming widely accepted for flood frequency change analysis. The use of multiple models results in large uncertainty around estimates of flood magnitudes, due to both uncertainty in model selection and natural variability of river flow. The challenge is therefore to extract the most meaningful signal from the multi-model predictions, accounting for both model quality and uncertainties in individual model estimates. The study demonstrates the potential of a recently proposed hierarchical Bayesian approach to combine information from multiple models. The approach facilitates explicit treatment of shared multi-model discrepancy as well as the probabilistic nature of the flood estimates, by treating the available models as a sample from a hypothetical complete (but unobserved) set of models. The advantages of the approach are: 1) to insure an adequate 'baseline' conditions with which to compare future changes; 2) to reduce flood estimate uncertainty; 3) to maximize use of statistical information in circumstances where multiple weak predictions individually lack power, but collectively provide meaningful information; 4) to adjust multi-model consistency criteria when model biases are large; and 5) to explicitly consider the influence of the (model performance) stationarity assumption. Moreover, the analysis indicates that reducing shared model discrepancy is the key to further reduction of uncertainty in the flood frequency analysis. The findings are of value regarding how conclusions about changing exposure to flooding are drawn, and to flood frequency change attribution studies.

High Risk Flash Flood Rainstorm Mapping Based on Regional L-moments Approach

NASA Astrophysics Data System (ADS)

Ding, Hui; Liao, Yifan; Lin, Bingzhang

2017-04-01

Difficulties and complexities in elaborating flash flood early-warning and forecasting system prompt hydrologists to develop some techniques to substantially reduce the disastrous outcome of a flash flood in advance. An ideal to specify those areas that are subject at high risk to flash flood in terms of rainfall intensity in a relatively large region is proposed in this paper. It is accomplished through design of the High Risk Flash Flood Rainstorm Area (HRFFRA) based on statistical analysis of historical rainfall data, synoptic analysis of prevailing storm rainfalls as well as the field survey of historical flash flood events in the region. A HRFFRA is defined as the area potentially under hitting by higher intense-precipitation for a given duration with certain return period that may cause a flash flood disaster in the area. This paper has presented in detail the development of the HRFFRA through the application of the end-to-end Regional L-moments Approach (RLMA) to precipitation frequency analysis in combination with the technique of spatial interpolation in Jiangxi Province, South China Mainland. Among others, the concept of hydrometeorologically homogenous region, the precision of frequency analysis in terms of parameter estimation, the accuracy of quantiles in terms of uncertainties and the consistency adjustments of quantiles over durations and space, etc., have been addressed. At the end of this paper, the mapping of the HRFFRA and an internet-based visualized user-friendly data-server of the HRFFRA are also introduced. Key words: HRFFRA; Flash Flood; RLMA; rainfall intensity; Hydrometeorological homogenous region.

The state of the art of flood forecasting - Hydrological Ensemble Prediction Systems

NASA Astrophysics Data System (ADS)

Thielen-Del Pozo, J.; Pappenberger, F.; Salamon, P.; Bogner, K.; Burek, P.; de Roo, A.

2010-09-01

Flood forecasting systems form a key part of ‘preparedness' strategies for disastrous floods and provide hydrological services, civil protection authorities and the public with information of upcoming events. Provided the warning leadtime is sufficiently long, adequate preparatory actions can be taken to efficiently reduce the impacts of the flooding. Because of the specific characteristics of each catchment, varying data availability and end-user demands, the design of the best flood forecasting system may differ from catchment to catchment. However, despite the differences in concept and data needs, there is one underlying issue that spans across all systems. There has been an growing awareness and acceptance that uncertainty is a fundamental issue of flood forecasting and needs to be dealt with at the different spatial and temporal scales as well as the different stages of the flood generating processes. Today, operational flood forecasting centres change increasingly from single deterministic forecasts to probabilistic forecasts with various representations of the different contributions of uncertainty. The move towards these so-called Hydrological Ensemble Prediction Systems (HEPS) in flood forecasting represents the state of the art in forecasting science, following on the success of the use of ensembles for weather forecasting (Buizza et al., 2005) and paralleling the move towards ensemble forecasting in other related disciplines such as climate change predictions. The use of HEPS has been internationally fostered by initiatives such as "The Hydrologic Ensemble Prediction Experiment" (HEPEX), created with the aim to investigate how best to produce, communicate and use hydrologic ensemble forecasts in hydrological short-, medium- und long term prediction of hydrological processes. The advantages of quantifying the different contributions of uncertainty as well as the overall uncertainty to obtain reliable and useful flood forecasts also for extreme events, has become evident. However, despite the demonstrated advantages, worldwide the incorporation of HEPS in operational flood forecasting is still limited. The applicability of HEPS for smaller river basins was tested in MAP D-Phase, an acronym for "Demonstration of Probabilistic Hydrological and Atmospheric Simulation of flood Events in the Alpine region" which was launched in 2005 as a Forecast Demonstration Project of World Weather Research Programme of WMO, and entered a pre-operational and still active testing phase in 2007. In Europe, a comparatively high number of EPS driven systems for medium-large rivers exist. National flood forecasting centres of Sweden, Finland and the Netherlands, have already implemented HEPS in their operational forecasting chain, while in other countries including France, Germany, Czech Republic and Hungary, hybrids or experimental chains have been installed. As an example of HEPS, the European Flood Alert System (EFAS) is being presented. EFAS provides medium-range probabilistic flood forecasting information for large trans-national river basins. It incorporates multiple sets of weather forecast including different types of EPS and deterministic forecasts from different providers. EFAS products are evaluated and visualised as exceedance of critical levels only - both in forms of maps and time series. Different sources of uncertainty and its impact on the flood forecasting performance for every grid cell has been tested offline but not yet incorporated operationally into the forecasting chain for computational reasons. However, at stations where real-time discharges are available, a hydrological uncertainty processor is being applied to estimate the total predictive uncertainty from the hydrological and input uncertainties. Research on long-term EFAS results has shown the need for complementing statistical analysis with case studies for which examples will be shown.

Impacts of floods on dysentery in Xinxiang city, China, during 2004-2010: a time-series Poisson analysis.

PubMed

Ni, Wei; Ding, Guoyong; Li, Yifei; Li, Hongkai; Jiang, Baofa

2014-01-01

Xinxiang, a city in Henan Province, suffered from frequent floods due to persistent and heavy precipitation from 2004 to 2010. In the same period, dysentery was a common public health problem in Xinxiang, with the proportion of reported cases being the third highest among all the notified infectious diseases. We focused on dysentery disease consequences of different degrees of floods and examined the association between floods and the morbidity of dysentery on the basis of longitudinal data during the study period. A time-series Poisson regression model was conducted to examine the relationship between 10 times different degrees of floods and the monthly morbidity of dysentery from 2004 to 2010 in Xinxiang. Relative risks (RRs) of moderate and severe floods on the morbidity of dysentery were calculated in this paper. In addition, we estimated the attributable contributions of moderate and severe floods to the morbidity of dysentery. A total of 7591 cases of dysentery were notified in Xinxiang during the study period. The effect of floods on dysentery was shown with a 0-month lag. Regression analysis showed that the risk of moderate and severe floods on the morbidity of dysentery was 1.55 (95% CI: 1.42-1.670) and 1.74 (95% CI: 1.56-1.94), respectively. The attributable risk proportions (ARPs) of moderate and severe floods to the morbidity of dysentery were 35.53 and 42.48%, respectively. This study confirms that floods have significantly increased the risk of dysentery in the study area. In addition, severe floods have a higher proportional contribution to the morbidity of dysentery than moderate floods. Public health action should be taken to avoid and control a potential risk of dysentery epidemics after floods.

Impacts of floods on dysentery in Xinxiang city, China, during 2004–2010: a time-series Poisson analysis

PubMed Central

Ni, Wei; Ding, Guoyong; Li, Yifei; Li, Hongkai; Jiang, Baofa

2014-01-01

Background Xinxiang, a city in Henan Province, suffered from frequent floods due to persistent and heavy precipitation from 2004 to 2010. In the same period, dysentery was a common public health problem in Xinxiang, with the proportion of reported cases being the third highest among all the notified infectious diseases. Objectives We focused on dysentery disease consequences of different degrees of floods and examined the association between floods and the morbidity of dysentery on the basis of longitudinal data during the study period. Design A time-series Poisson regression model was conducted to examine the relationship between 10 times different degrees of floods and the monthly morbidity of dysentery from 2004 to 2010 in Xinxiang. Relative risks (RRs) of moderate and severe floods on the morbidity of dysentery were calculated in this paper. In addition, we estimated the attributable contributions of moderate and severe floods to the morbidity of dysentery. Results A total of 7591 cases of dysentery were notified in Xinxiang during the study period. The effect of floods on dysentery was shown with a 0-month lag. Regression analysis showed that the risk of moderate and severe floods on the morbidity of dysentery was 1.55 (95% CI: 1.42–1.670) and 1.74 (95% CI: 1.56–1.94), respectively. The attributable risk proportions (ARPs) of moderate and severe floods to the morbidity of dysentery were 35.53 and 42.48%, respectively. Conclusions This study confirms that floods have significantly increased the risk of dysentery in the study area. In addition, severe floods have a higher proportional contribution to the morbidity of dysentery than moderate floods. Public health action should be taken to avoid and control a potential risk of dysentery epidemics after floods. PMID:25098726

Evaluation of the magnitude and frequency of floods in urban watersheds in Phoenix and Tucson, Arizona

USGS Publications Warehouse

Kennedy, Jeffrey R.; Paretti, Nicholas V.

2014-01-01

Flooding in urban areas routinely causes severe damage to property and often results in loss of life. To investigate the effect of urbanization on the magnitude and frequency of flood peaks, a flood frequency analysis was carried out using data from urbanized streamgaging stations in Phoenix and Tucson, Arizona. Flood peaks at each station were predicted using the log-Pearson Type III distribution, fitted using the expected moments algorithm and the multiple Grubbs-Beck low outlier test. The station estimates were then compared to flood peaks estimated by rural-regression equations for Arizona, and to flood peaks adjusted for urbanization using a previously developed procedure for adjusting U.S. Geological Survey rural regression peak discharges in an urban setting. Only smaller, more common flood peaks at the 50-, 20-, 10-, and 4-percent annual exceedance probabilities (AEPs) demonstrate any increase in magnitude as a result of urbanization; the 1-, 0.5-, and 0.2-percent AEP flood estimates are predicted without bias by the rural-regression equations. Percent imperviousness was determined not to account for the difference in estimated flood peaks between stations, either when adjusting the rural-regression equations or when deriving urban-regression equations to predict flood peaks directly from basin characteristics. Comparison with urban adjustment equations indicates that flood peaks are systematically overestimated if the rural-regression-estimated flood peaks are adjusted upward to account for urbanization. At nearly every streamgaging station in the analysis, adjusted rural-regression estimates were greater than the estimates derived using station data. One likely reason for the lack of increase in flood peaks with urbanization is the presence of significant stormwater retention and detention structures within the watershed used in the study.

Examples of the great cross-border floods in Central Europe and lessons learnt (case studies: September and November 1890 on the occasion of their 120 anniversary)

NASA Astrophysics Data System (ADS)

Munzar, Jan; et al.

2010-05-01

With the respect to the size of extreme floods far beyond the borders of neighbouring countries, their research and comparison are possible only on the basis of a long-term international cooperation. There is only limited knowledge about the impacts of important historic floods affecting at the same time territories of multiple countries and attempts at flood-control measures in the past. E.g. only short time after catastrophic flood in September 1890 of European scope the imperial and royal governor of Bohemia issued in January 1891 a decree on the introduction of flood warning service on Czech rivers with instructions and a duty to send reports and warnings to Dresden, too. With respect to the fact that this flood occurred on an extensive part of Europe including the Danube R., the event became the last impulse for the establishment of an integrated hydrographic service in an Austrian Monarchy with the headquarters in Vienna in 1893. In comparison with the first case from September 1890 is the second one - the important flood from the end of November 1890, which affected e.g. Ohře/Eger R. in Bohemia (and destroyed the well-known spa Carlsbad) and simultaneously Saale R. in Thuringia, is up today practically without the attention of specialists: therefore is in focus of our contribution.

Defining Flood Zone Transitions in Low-Gradient Coastal Regions

NASA Astrophysics Data System (ADS)

Bilskie, M. V.; Hagen, S. C.

2018-03-01

Worldwide, coastal, and deltaic communities are susceptible to flooding from the individual and combined effects of rainfall excess and astronomic tide and storm surge inundation. Such flood events are a present (and future) cause of concern as observed from recent storms such as the 2016 Louisiana flood and Hurricanes Harvey, Irma, and Maria. To assess flood risk across coastal landscapes, it is advantageous to first delineate flood transition zones, which we define as areas susceptible to hydrologic and coastal flooding and their collective interaction. We utilize numerical simulations combining rainfall excess and storm surge for the 2016 Louisiana flood to describe a flood transition zone for southeastern Louisiana. We show that the interaction of rainfall excess with coastal surge is nonlinear and less than the superposition of their individual components. Our analysis provides a foundation to define flooding zones across coastal landscapes throughout the world to support flood risk assessments.

Special Flood Hazard Evaluation Report, Maumee River, Defiance and Paulding Counties, Ohio

DTIC Science & Technology

1988-01-01

into the Flood Flow Frequency Analysis (FFFA) computer program (Reference 3) to determine the discharge-frequency relationship for the Maumee River...although the flood may occur in any year. It is based on statistical analysis of streamflow records available for the watershed and analysis of rainfall...C) K) K4 10 ERFODBUDR .S ryEgne itit ufI N - FODA ONAYSEIA LO AADEAUTO 6 ? -F -C )I= ~ - %E )tvXJ. AE LO LVTO MAMERVE CROS SECIONLOCAION DEFINCEAND

Near Real-Time Flood Monitoring and Impact Assessment Systems. Chapter 6; [Case Study: 2011 Flooding in Southeast Asia

NASA Technical Reports Server (NTRS)

Ahamed, Aakash; Bolten, John; Doyle, Colin; Fayne, Jessica

2016-01-01

Floods are the costliest natural disaster, causing approximately 6.8 million deaths in the twentieth century alone. Worldwide economic flood damage estimates in 2012 exceed $19 Billion USD. Extended duration floods also pose longer term threats to food security, water, sanitation, hygiene, and community livelihoods, particularly in developing countries. Projections by the Intergovernmental Panel on Climate Change (IPCC) suggest that precipitation extremes, rainfall intensity, storm intensity, and variability are increasing due to climate change. Increasing hydrologic uncertainty will likely lead to unprecedented extreme flood events. As such, there is a vital need to enhance and further develop traditional techniques used to rapidly assess flooding and extend analytical methods to estimate impacted population and infrastructure. Measuring flood extent in situ is generally impractical, time consuming, and can be inaccurate. Remotely sensed imagery acquired from space-borne and airborne sensors provides a viable platform for consistent and rapid wall-to-wall monitoring of large flood events through time. Terabytes of freely available satellite imagery are made available online each day by NASA, ESA, and other international space research institutions. Advances in cloud computing and data storage technologies allow researchers to leverage these satellite data and apply analytical methods at scale. Repeat-survey earth observations help provide insight about how natural phenomena change through time, including the progression and recession of floodwaters. In recent years, cloud-penetrating radar remote sensing techniques (e.g., Synthetic Aperture Radar) and high temporal resolution imagery platforms (e.g., MODIS and its 1-day return period), along with high performance computing infrastructure, have enabled significant advances in software systems that provide flood warning, assessments, and hazard reduction potential. By incorporating social and economic data, researchers can develop systems that automatically quantify the socioeconomic impacts resulting from flood disaster events.

Opportunities for multivariate analysis of open spatial datasets to characterize urban flooding risks

NASA Astrophysics Data System (ADS)

Gaitan, S.; ten Veldhuis, J. A. E.

2015-06-01

Cities worldwide are challenged by increasing urban flood risks. Precise and realistic measures are required to reduce flooding impacts. However, currently implemented sewer and topographic models do not provide realistic predictions of local flooding occurrence during heavy rain events. Assessing other factors such as spatially distributed rainfall, socioeconomic characteristics, and social sensing, may help to explain probability and impacts of urban flooding. Several spatial datasets have been recently made available in the Netherlands, including rainfall-related incident reports made by citizens, spatially distributed rain depths, semidistributed socioeconomic information, and buildings age. Inspecting the potential of this data to explain the occurrence of rainfall related incidents has not been done yet. Multivariate analysis tools for describing communities and environmental patterns have been previously developed and used in the field of study of ecology. The objective of this paper is to outline opportunities for these tools to explore urban flooding risks patterns in the mentioned datasets. To that end, a cluster analysis is performed. Results indicate that incidence of rainfall-related impacts is higher in areas characterized by older infrastructure and higher population density.

Accuracy Analysis and Parameters Optimization in Urban Flood Simulation by PEST Model

NASA Astrophysics Data System (ADS)

Keum, H.; Han, K.; Kim, H.; Ha, C.

2017-12-01

The risk of urban flooding has been increasing due to heavy rainfall, flash flooding and rapid urbanization. Rainwater pumping stations, underground reservoirs are used to actively take measures against flooding, however, flood damage from lowlands continues to occur. Inundation in urban areas has resulted in overflow of sewer. Therefore, it is important to implement a network system that is intricately entangled within a city, similar to the actual physical situation and accurate terrain due to the effects on buildings and roads for accurate two-dimensional flood analysis. The purpose of this study is to propose an optimal scenario construction procedure watershed partitioning and parameterization for urban runoff analysis and pipe network analysis, and to increase the accuracy of flooded area prediction through coupled model. The establishment of optimal scenario procedure was verified by applying it to actual drainage in Seoul. In this study, optimization was performed by using four parameters such as Manning's roughness coefficient for conduits, watershed width, Manning's roughness coefficient for impervious area, Manning's roughness coefficient for pervious area. The calibration range of the parameters was determined using the SWMM manual and the ranges used in the previous studies, and the parameters were estimated using the automatic calibration method PEST. The correlation coefficient showed a high correlation coefficient for the scenarios using PEST. The RPE and RMSE also showed high accuracy for the scenarios using PEST. In the case of RPE, error was in the range of 13.9-28.9% in the no-parameter estimation scenarios, but in the scenario using the PEST, the error range was reduced to 6.8-25.7%. Based on the results of this study, it can be concluded that more accurate flood analysis is possible when the optimum scenario is selected by determining the appropriate reference conduit for future urban flooding analysis and if the results is applied to various rainfall event scenarios and parameter optimization. Keywords: Parameters Optimization; PEST model; Urban area Acknowledgement This research was supported by a grant (17AWMP-B079625-04) from Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

Exploring public databases to characterize urban flood risks in Amsterdam

NASA Astrophysics Data System (ADS)

Gaitan, Santiago; ten Veldhuis, Marie-claire; van de Giesen, Nick

2015-04-01

Cities worldwide are challenged by increasing urban flood risks. Precise and realistic measures are required to decide upon investment to reduce their impacts. Obvious flooding factors affecting flood risk include sewer systems performance and urban topography. However, currently implemented sewer and topographic models do not provide realistic predictions of local flooding occurrence during heavy rain events. Assessing other factors such as spatially distributed rainfall and socioeconomic characteristics may help to explain probability and impacts of urban flooding. Several public databases were analyzed: complaints about flooding made by citizens, rainfall depths (15 min and 100 Ha spatio-temporal resolution), grids describing number of inhabitants, income, and housing price (1Ha and 25Ha resolution); and buildings age. Data analysis was done using Python and GIS programming, and included spatial indexing of data, cluster analysis, and multivariate regression on the complaints. Complaints were used as a proxy to characterize flooding impacts. The cluster analysis, run for all the variables except the complaints, grouped part of the grid-cells of central Amsterdam into a highly differentiated group, covering 10% of the analyzed area, and accounting for 25% of registered complaints. The configuration of the analyzed variables in central Amsterdam coincides with a high complaint count. Remaining complaints were evenly dispersed along other groups. An adjusted R2 of 0.38 in the multivariate regression suggests that explaining power can improve if additional variables are considered. While rainfall intensity explained 4% of the incidence of complaints, population density and building age significantly explained around 20% each. Data mining of public databases proved to be a valuable tool to identify factors explaining variability in occurrence of urban pluvial flooding, though additional variables must be considered to fully explain flood risk variability.

Comparison of Alaskan Flood Stages: Annual Exceedance Probability vs. Impact Based Stages and Recommendations for the Future

NASA Astrophysics Data System (ADS)

Anderson, B. J.

2016-12-01

The Alaska River Forecasting Center (APRFC) issues water level forecasts that are used in conjunction with established flood stages to provide flood warning and advisory information to the public. The APRFC typically establishes flood stages based on observed impacts but Alaska has sparse empirical data (e.g., few impact surveys). Thus service hydrologists in Alaska use flood frequency analysis (LP3 distribution) to estimate flood stages from annual exceedance probabilities (AEPs) (Curran et al, 2016). Previously, the APRFC has maintained that bankfull stage corresponds to the 50% AEP, minor to 10-20% AEP, moderate to 2.5-7% AEP, and major to 1-2% AEP, but we now need to statistically verify this relationship. Our objective is therefore to validate the relationship between flood stages and stage associated with the 50, 20, 10, 4, 2, 1, 0.2, and 0.5 AEPs to provide recommendations for improved flood forecasting. We studied the relationship between AEP and flood stage for all gages (56) used by the APRFC that had rating curves not older than 3 years, flood stages based on observed impacts, and at least 10 years of peak annual stage data. The analysis found relatively strong relationships for all flood stages, except for bankfull stage, but with some differences when compared to the traditionally referenced relationship. Major flood stage appears to be most similar to the 1-.2% AEP (100-500 year RI) while moderate flood stage best fits the 2-4% AEP (25-50 year interval). Gages showing a difference in stage of 2 ft or greater exhibited this difference across all flood stages, which we link to site specific qualities such as susceptibility to ice-jam flooding. We present this method as a possible application to Alaskan Rivers as a general flood stage guideline.

Application of the TDR technique for the detection of changes in the internal structure of an earthen flood levee

NASA Astrophysics Data System (ADS)

Janik, Grzegorz; Dawid, Małgorzata; Walczak, Amadeusz; Słowińska-Osypiuk, Joanna; Skierucha, Wojciech; Wilczek, Andrzej; Daniel, Anna

2017-03-01

Failures of earthen flood protection structures cause enormous material loss. Despite this, in the majority these are structures that were built decades ago. As an example, in Poland, the time of operation of approximately three quarters of existing levees and embankments is over 40 years. A similar situation exists in many other European countries. In the period 1998-2009 the economic losses caused by floods amounted to over 60 thousand million Euro. This accounts for approximately one third of the total losses caused by environmental factors. Ruptures of embankments or levees occur as a result of long-lasting elevated water levels in rivers, and such events are always preceded by changes in their internal structure. Such changes cannot be detected from the outside. This paper presents a new method, never used before, for the determination of changes in the internal structure of the body of a levee. The dynamics of the displacements is described by means of new mathematical formulae. The input data necessary for their application include the dynamics of changes in the value of volumetric moisture that is measured with a freely selected short time step by means of the time-domain-reflectrometry technique. The formulae were created on the basis of hitherto unnoticed and uninterpreted drops in moisture a moment before and a moment after the saturation of inner spaces of the levee body. The results obtained from calculations were compared with data from measurements on a physical model of a levee. The settlement values calculated using the method proposed are convergent with those of the true settlement. The maximum relative error was as low as 19%. The method proposed permits the location of changes in the internal structure of a levee before its rupture. Its application is the main component of a system of early warning against floods.

A free and open source QGIS plugin for flood risk analysis: FloodRisk

NASA Astrophysics Data System (ADS)

Albano, Raffaele; Sole, Aurelia; Mancusi, Leonardo

2016-04-01

An analysis of global statistics shows a substantial increase in flood damage over the past few decades. Moreover, it is expected that flood risk will continue to rise due to the combined effect of increasing numbers of people and economic assets in risk-prone areas and the effects of climate change. In order to increase the resilience of European economies and societies, the improvement of risk assessment and management has been pursued in the last years. This results in a wide range of flood analysis models of different complexities with substantial differences in underlying components needed for its implementation, as geographical, hydrological and social differences demand specific approaches in the different countries. At present, it is emerging the need of promote the creation of open, transparent, reliable and extensible tools for a comprehensive, context-specific and applicable flood risk analysis. In this context, the free and open-source Quantum GIS (QGIS) plugin "FloodRisk" is a good starting point to address this objective. The vision of the developers of this free and open source software (FOSS) is to combine the main features of state-of-the-art science, collaboration, transparency and interoperability in an initiative to assess and communicate flood risk worldwide and to assist authorities to facilitate the quality and fairness of flood risk management at multiple scales. Among the scientific community, this type of activity can be labelled as "participatory research", intended as adopting a set of techniques that "are interactive and collaborative" and reproducible, "providing a meaningful research experience that both promotes learning and generates knowledge and research data through a process of guided discovery"' (Albano et al., 2015). Moreover, this FOSS geospatial approach can lowering the financial barriers to understanding risks at national and sub-national levels through a spatio-temporal domain and can provide better and more complete information and to generate knowledge in the stakeholders for improving flood risk management. In particular, Floodrisk comprises a set of calculators capable of computing human or economic losses for a collection of assets, caused by a given scenario event, explicitly covering mitigation and adaptation measures (Mancusi et al., 2015). It is important to mention that despite the fact that some literature models incorporates calculator philosophies identical to the ones implemented in the FloodRisk engine, its implementation might vary significantly, such as the need for a user-friendly and intuitive user interface, or the capability of running the calculations on any platform (Windows, Mac, Linux, etc.), the ability to promotes extensibility, efficient testability, and scientific operability. FloodRisk has been designed as an initiative for implemented a standard and harmonized procedure to determine the flood impacts. Albano, R.; Mancusi, L.; Sole, A.; Adamowski, J. Collaborative Strategies for Sustainable EU Flood Risk Management: FOSS and Geospatial Tools - Challenges and Opportunities for Operative Risk Analysis. ISPRS Int. J. Geo-Inf. 2015, 4, 2704-2727. Mancusi, L., Albano, R., Sole, A.. FloodRisk: a QGIS plugin for flood consequences estimation, In: Geomatics Workbooks n°12 - FOSS4G Europe Como, 2015

Quantitative Analysis of Burden of Infectious Diarrhea Associated with Floods in Northwest of Anhui Province, China: A Mixed Method Evaluation

PubMed Central

Ding, Guoyong; Zhang, Ying; Gao, Lu; Ma, Wei; Li, Xiujun; Liu, Jing; Liu, Qiyong; Jiang, Baofa

2013-01-01

Background Persistent and heavy rainfall in the upper and middle Huaihe River of China brought about severe floods during the end of June and July 2007. However, there has been no assessment on the association between the floods and infectious diarrhea. This study aimed to quantify the impact of the floods in 2007 on the burden of disease due to infectious diarrhea in northwest of Anhui Province. Methods A time-stratified case-crossover analysis was firstly conducted to examine the relationship between daily cases of infectious diarrhea and the 2007 floods in Fuyang and Bozhou of Anhui Province. Odds ratios (ORs) of the flood risk were quantified by conditional logistic regression. The years lived with disability (YLDs) of infectious diarrhea attributable to floods were then estimated based on the WHO framework of the calculating potential impact fraction in the Burden of Disease study. Results A total of 197 infectious diarrheas were notified during the exposure and control periods in the two study areas. The strongest effect was shown with a 2-day lag in Fuyang and a 5-day lag in Bozhou. Multivariable analysis showed that floods were significantly associated with an increased risk of the number cases of infectious diarrhea (OR = 3.175, 95%CI: 1.126–8.954 in Fuyang; OR = 6.754, 95%CI: 1.954–23.344 in Bozhou). Attributable YLD per 1000 of infectious diarrhea resulting from the floods was 0.0081 in Fuyang and 0.0209 in Bozhou. Conclusions Our findings confirm that floods have significantly increased the risks of infectious diarrhea in the study areas. In addition, prolonged moderate flood may cause more burdens of infectious diarrheas than severe flood with a shorter duration. More attention should be paid to particular vulnerable groups, including younger children and elderly, in developing public health preparation and intervention programs. Findings have significant implications for developing strategies to prevent and reduce health impact of floods. PMID:23762291

Flooding Experiments and Modeling for Improved Reactor Safety

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solmos, M.; Hogan, K. J.; Vierow, K.

2008-09-14

Countercurrent two-phase flow and “flooding” phenomena in light water reactor systems are being investigated experimentally and analytically to improve reactor safety of current and future reactors. The aspects that will be better clarified are the effects of condensation and tube inclination on flooding in large diameter tubes. The current project aims to improve the level of understanding of flooding mechanisms and to develop an analysis model for more accurate evaluations of flooding in the pressurizer surge line of a Pressurized Water Reactor (PWR). Interest in flooding has recently increased because Countercurrent Flow Limitation (CCFL) in the AP600 pressurizer surge linemore » can affect the vessel refill rate following a small break LOCA and because analysis of hypothetical severe accidents with the current flooding models in reactor safety codes shows that these models represent the largest uncertainty in analysis of steam generator tube creep rupture. During a hypothetical station blackout without auxiliary feedwater recovery, should the hot leg become voided, the pressurizer liquid will drain to the hot leg and flooding may occur in the surge line. The flooding model heavily influences the pressurizer emptying rate and the potential for surge line structural failure due to overheating and creep rupture. The air-water test results in vertical tubes are presented in this paper along with a semi-empirical correlation for the onset of flooding. The unique aspects of the study include careful experimentation on large-diameter tubes and an integrated program in which air-water testing provides benchmark knowledge and visualization data from which to conduct steam-water testing.« less

Evaluating influence of active tectonics on spatial distribution pattern of floods along eastern Tamil Nadu, India

NASA Astrophysics Data System (ADS)

Selvakumar, R.; Ramasamy, SM.

2014-12-01

Flooding is a naturally recurrent phenomenon that causes severe damage to lives and property. Predictions on flood-prone zones are made based on intensity-duration of rainfall, carrying capacity of drainage, and natural or man-made obstructions. Particularly, the lower part of the drainage system and its adjacent geomorphic landforms like floodplains and deltaic plains are considered for analysis, but stagnation in parts of basins that are far away from major riverine systems is less unveiled. Similarly, uncharacteristic flooding in the upper and middle parts of drainage, especially in zones of an anomalous drainage pattern, is also least understood. Even though topographic differences are attributed for such anomalous spatial occurrence of floods, its genetic cause has to be identified for effective management practice. Added to structural and lithological variations, tectonic movements too impart micro-scale terrain undulations. Because active tectonic movements are slow-occurring, long-term geological processes, its resultant topographical variations and drainage anomalies are least correlated with floods. The recent floods of Tamil Nadu also exhibit a unique distribution pattern emphasizing the role of tectonics over it. Hence a detailed geoinformatics-based analysis was carried out to envisage the relationship between spatial distribution of flood and active tectonic elements such as regional arches and deeps, block faults, and graben and drainage anomalies such as deflected drainage, compressed meander, and eyed drainages. The analysis reveals that micro-scale topographic highs and lows imparted by active tectonic movements and its further induced drainage anomalies have substantially controlled the distribution pattern of flood.

Flood analysis in mixed-urban areas reflecting interactions with the complete water cycle through coupled hydrologic-hydraulic modelling.

PubMed

Sto Domingo, N D; Refsgaard, A; Mark, O; Paludan, B

2010-01-01

The potential devastating effects of urban flooding have given high importance to thorough understanding and management of water movement within catchments, and computer modelling tools have found widespread use for this purpose. The state-of-the-art in urban flood modelling is the use of a coupled 1D pipe and 2D overland flow model to simultaneously represent pipe and surface flows. This method has been found to be accurate for highly paved areas, but inappropriate when land hydrology is important. The objectives of this study are to introduce a new urban flood modelling procedure that is able to reflect system interactions with hydrology, verify that the new procedure operates well, and underline the importance of considering the complete water cycle in urban flood analysis. A physically-based and distributed hydrological model was linked to a drainage network model for urban flood analysis, and the essential components and concepts used were described in this study. The procedure was then applied to a catchment previously modelled with the traditional 1D-2D procedure to determine if the new method performs similarly well. Then, results from applying the new method in a mixed-urban area were analyzed to determine how important hydrologic contributions are to flooding in the area.

A quantitative flood risk analysis methodology for urban areas with integration of social research data

NASA Astrophysics Data System (ADS)

Escuder-Bueno, I.; Castillo-Rodríguez, J. T.; Zechner, S.; Jöbstl, C.; Perales-Momparler, S.; Petaccia, G.

2012-09-01

Risk analysis has become a top priority for authorities and stakeholders in many European countries, with the aim of reducing flooding risk, considering the population's needs and improving risk awareness. Within this context, two methodological pieces have been developed in the period 2009-2011 within the SUFRI project (Sustainable Strategies of Urban Flood Risk Management with non-structural measures to cope with the residual risk, 2nd ERA-Net CRUE Funding Initiative). First, the "SUFRI Methodology for pluvial and river flooding risk assessment in urban areas to inform decision-making" provides a comprehensive and quantitative tool for flood risk analysis. Second, the "Methodology for investigation of risk awareness of the population concerned" presents the basis to estimate current risk from a social perspective and identify tendencies in the way floods are understood by citizens. Outcomes of both methods are integrated in this paper with the aim of informing decision making on non-structural protection measures. The results of two case studies are shown to illustrate practical applications of this developed approach. The main advantage of applying the methodology herein presented consists in providing a quantitative estimation of flooding risk before and after investing in non-structural risk mitigation measures. It can be of great interest for decision makers as it provides rational and solid information.

Influence of extreme weather disasters on global crop production.

PubMed

Lesk, Corey; Rowhani, Pedram; Ramankutty, Navin

2016-01-07

In recent years, several extreme weather disasters have partially or completely damaged regional crop production. While detailed regional accounts of the effects of extreme weather disasters exist, the global scale effects of droughts, floods and extreme temperature on crop production are yet to be quantified. Here we estimate for the first time, to our knowledge, national cereal production losses across the globe resulting from reported extreme weather disasters during 1964-2007. We show that droughts and extreme heat significantly reduced national cereal production by 9-10%, whereas our analysis could not identify an effect from floods and extreme cold in the national data. Analysing the underlying processes, we find that production losses due to droughts were associated with a reduction in both harvested area and yields, whereas extreme heat mainly decreased cereal yields. Furthermore, the results highlight ~7% greater production damage from more recent droughts and 8-11% more damage in developed countries than in developing ones. Our findings may help to guide agricultural priorities in international disaster risk reduction and adaptation efforts.

Flood Disaster Analysis Using Landsat-8 and SPOT-6 Imagery for Determination of Flooded Areas in Sampang, Madura

NASA Astrophysics Data System (ADS)

Sukojo, B. M.; Alfiansyah, F.

2017-12-01

Based on data of disaster which is defaced by Badan Penanggulangan Bencana Daerah (BPBD) of Sampang that in the period of 2015 - 2017 as many as 25 cases from 31 cases of disaster caused by flood disaster or 80.65% from total disaster. Therefore, the purpose of this research is to create a map of flood vulnerability in Sampang. From the vulnerability map, we can know the area with the impacted flood level in Sampang so that from the map of flood affected areas can be known the extent of the affected area in each class. In this study, two Landsat-8 and SPOT 6 data were used. For Landsat-8 imagery used for land cover on district level disaster level vulnerability maps, while high-resolution SPOT-6 images were used for land cover making maps of flood affected areas Sampang district. With the flood affected areas in this study, it is expected to be used as a determinant of flood affected areas in Sampang district. Based on data processing and analysis it is found that the highest impacted area is located in Sampang district with 12 cases of 17 cases of total flood disaster in Sampang district based on data from BPBD Kabupaten Sampang in 2016. There are 4 classes of flood affected areas in Sampang district i.e. not affected by 9039,540 ha, low impact 46262.881 ha, medium impact 43012.431 ha and high impact of 14009,760 ha.

How do people perceive, understand, and anticipate responding to flash flood risks and warnings? Results from a public survey in Boulder, Colorado, USA

NASA Astrophysics Data System (ADS)

Morss, Rebecca E.; Mulder, Kelsey J.; Lazo, Jeffrey K.; Demuth, Julie L.

2016-10-01

This study investigates flash flood forecast and warning communication, interpretation, and decision making, using data from a survey of 418 members of the public in Boulder, Colorado, USA. Respondents to the public survey varied in their perceptions and understandings of flash flood risks in Boulder, and some had misconceptions about flash flood risks, such as the safety of crossing fast-flowing water. About 6% of respondents indicated consistent reversals of US watch-warning alert terminology. However, more in-depth analysis illustrates the multi-dimensional, situationally dependent meanings of flash flood alerts, as well as the importance of evaluating interpretation and use of warning information along with alert terminology. Some public respondents estimated low likelihoods of flash flooding given a flash flood warning; these were associated with lower anticipated likelihood of taking protective action given a warning. Protective action intentions were also lower among respondents who had less trust in flash flood warnings, those who had not made prior preparations for flash flooding, and those who believed themselves to be safer from flash flooding. Additional analysis, using open-ended survey questions about responses to warnings, elucidates the complex, contextual nature of protective decision making during flash flood threats. These findings suggest that warnings can play an important role not only by notifying people that there is a threat and helping motivate people to take protective action, but also by helping people evaluate what actions to take given their situation.

Nuclear Proteomics Reveals the Role of Protein Synthesis and Chromatin Structure in Root Tip of Soybean during the Initial Stage of Flooding Stress.

PubMed

Yin, Xiaojian; Komatsu, Setsuko

2016-07-01

To identify the upstream events controlling the regulation of flooding-responsive proteins in soybean, proteomic analysis of nuclear proteins in root tip was performed. By using nuclear fractions, which were highly enriched, a total of 365 nuclear proteins were changed in soybean root tip at initial stage of flooding stress. Four exon-junction complex-related proteins and NOP1/NOP56, which function in upstream of 60S preribosome biogenesis, were decreased in flooded soybean. Furthermore, proteomic analysis of crude protein extract revealed that the protein translation was suppressed by continuous flooding stress. Seventeen chromatin structure-related nuclear proteins were decreased in response to flooding stress. Out of them, histone H3 was clearly decreased with protein abundance and mRNA expression levels at the initial flooding stress. Additionally, a number of protein synthesis-, RNA-, and DNA-related nuclear proteins were decreased in a time-dependent manner. mRNA expressions of genes encoding the significantly changed flooding-responsive nuclear proteins were inhibited by the transcriptional inhibitor, actinomycin D. These results suggest that protein translation is suppressed through inhibition of preribosome biogenesis- and mRNA processing-related proteins in nuclei of soybean root tip at initial flooding stress. In addition, flooding stress may regulate histone variants with gene expression in root tip.

A Study on Integrated Community Based Flood Mitigation with Remote Sensing Technique in Kota Bharu, Kelantan

NASA Astrophysics Data System (ADS)

'Ainullotfi, A. A.; Ibrahim, A. L.; Masron, T.

2014-02-01

This study is conducted to establish a community based flood management system that is integrated with remote sensing technique. To understand local knowledge, the demographic of the local society is obtained by using the survey approach. The local authorities are approached first to obtain information regarding the society in the study areas such as the population, the gender and the tabulation of settlement. The information about age, religion, ethnic, occupation, years of experience facing flood in the area, are recorded to understand more on how the local knowledge emerges. Then geographic data is obtained such as rainfall data, land use, land elevation, river discharge data. This information is used to establish a hydrological model of flood in the study area. Analysis were made from the survey approach to understand the pattern of society and how they react to floods while the analysis of geographic data is used to analyse the water extent and damage done by the flood. The final result of this research is to produce a flood mitigation method with a community based framework in the state of Kelantan. With the flood mitigation that involves the community's understanding towards flood also the techniques to forecast heavy rainfall and flood occurrence using remote sensing, it is hope that it could reduce the casualties and damage that might cause to the society and infrastructures in the study area.

On identifying relationships between the flood scaling exponent and basin attributes.

PubMed

Medhi, Hemanta; Tripathi, Shivam

2015-07-01

Floods are known to exhibit self-similarity and follow scaling laws that form the basis of regional flood frequency analysis. However, the relationship between basin attributes and the scaling behavior of floods is still not fully understood. Identifying these relationships is essential for drawing connections between hydrological processes in a basin and the flood response of the basin. The existing studies mostly rely on simulation models to draw these connections. This paper proposes a new methodology that draws connections between basin attributes and the flood scaling exponents by using observed data. In the proposed methodology, region-of-influence approach is used to delineate homogeneous regions for each gaging station. Ordinary least squares regression is then applied to estimate flood scaling exponents for each homogeneous region, and finally stepwise regression is used to identify basin attributes that affect flood scaling exponents. The effectiveness of the proposed methodology is tested by applying it to data from river basins in the United States. The results suggest that flood scaling exponent is small for regions having (i) large abstractions from precipitation in the form of large soil moisture storages and high evapotranspiration losses, and (ii) large fractions of overland flow compared to base flow, i.e., regions having fast-responding basins. Analysis of simple scaling and multiscaling of floods showed evidence of simple scaling for regions in which the snowfall dominates the total precipitation.

Large Scale Processes and Extreme Floods in Brazil

NASA Astrophysics Data System (ADS)

Ribeiro Lima, C. H.; AghaKouchak, A.; Lall, U.

2016-12-01

Persistent large scale anomalies in the atmospheric circulation and ocean state have been associated with heavy rainfall and extreme floods in water basins of different sizes across the world. Such studies have emerged in the last years as a new tool to improve the traditional, stationary based approach in flood frequency analysis and flood prediction. Here we seek to advance previous studies by evaluating the dominance of large scale processes (e.g. atmospheric rivers/moisture transport) over local processes (e.g. local convection) in producing floods. We consider flood-prone regions in Brazil as case studies and the role of large scale climate processes in generating extreme floods in such regions is explored by means of observed streamflow, reanalysis data and machine learning methods. The dynamics of the large scale atmospheric circulation in the days prior to the flood events are evaluated based on the vertically integrated moisture flux and its divergence field, which are interpreted in a low-dimensional space as obtained by machine learning techniques, particularly supervised kernel principal component analysis. In such reduced dimensional space, clusters are obtained in order to better understand the role of regional moisture recycling or teleconnected moisture in producing floods of a given magnitude. The convective available potential energy (CAPE) is also used as a measure of local convection activities. We investigate for individual sites the exceedance probability in which large scale atmospheric fluxes dominate the flood process. Finally, we analyze regional patterns of floods and how the scaling law of floods with drainage area responds to changes in the climate forcing mechanisms (e.g. local vs large scale).

Mental health impacts of flooding: a controlled interrupted time series analysis of prescribing data in England

PubMed Central

Milojevic, Ai; Armstrong, Ben; Wilkinson, Paul

2017-01-01

Background There is emerging evidence that people affected by flooding suffer adverse impacts on their mental well-being, mostly based on self-reports. Methods We examined prescription records for drugs used in the management of common mental disorder among primary care practices located in the vicinity of recent large flood events in England, 2011–2014. A controlled interrupted time series analysis was conducted of the number of prescribing items for antidepressant drugs in the year before and after the flood onset. Pre–post changes were compared by distance of the practice from the inundated boundaries among 930 practices located within 10 km of a flood. Results After control for deprivation and population density, there was an increase of 0.59% (95% CI 0.24 to 0.94) prescriptions in the postflood year among practices located within 1 km of a flood over and above the change observed in the furthest distance band. The increase was greater in more deprived areas. Conclusions This study suggests an increase in prescribed antidepressant drugs in the year after flooding in primary care practices close to recent major floods in England. The degree to which the increase is actually concentrated in those flooded can only be determined by more detailed linkage studies. PMID:28860201

Information Communication using Knowledge Engine on Flood Issues

NASA Astrophysics Data System (ADS)

Demir, I.; Krajewski, W. F.

2012-04-01

The Iowa Flood Information System (IFIS) is a web-based platform developed by the Iowa Flood Center (IFC) to provide access to and visualization of flood inundation maps, real-time flood conditions, flood forecasts both short-term and seasonal, and other flood-related data for communities in Iowa. The system is designed for use by general public, often people with no domain knowledge and poor general science background. To improve effective communication with such audience, we have introduced a new way in IFIS to get information on flood related issues - instead of by navigating within hundreds of features and interfaces of the information system and web-based sources-- by providing dynamic computations based on a collection of built-in data, analysis, and methods. The IFIS Knowledge Engine connects to distributed sources of real-time stream gauges, and in-house data sources, analysis and visualization tools to answer questions grouped into several categories. Users will be able to provide input based on the query within the categories of rainfall, flood conditions, forecast, inundation maps, flood risk and data sensors. Our goal is the systematization of knowledge on flood related issues, and to provide a single source for definitive answers to factual queries. Long-term goal of this knowledge engine is to make all flood related knowledge easily accessible to everyone, and provide educational geoinformatics tool. The future implementation of the system will be able to accept free-form input and voice recognition capabilities within browser and mobile applications. We intend to deliver increasing capabilities for the system over the coming releases of IFIS. This presentation provides an overview of our Knowledge Engine, its unique information interface and functionality as an educational tool, and discusses the future plans for providing knowledge on flood related issues and resources.

Classification of mechanisms, climatic context, areal scaling, and synchronization of floods: the hydroclimatology of floods in the Upper Paraná River basin, Brazil

NASA Astrophysics Data System (ADS)

Lima, Carlos H. R.; AghaKouchak, Amir; Lall, Upmanu

2017-12-01

Floods are the main natural disaster in Brazil, causing substantial economic damage and loss of life. Studies suggest that some extreme floods result from a causal climate chain. Exceptional rain and floods are determined by large-scale anomalies and persistent patterns in the atmospheric and oceanic circulations, which influence the magnitude, extent, and duration of these extremes. Moreover, floods can result from different generating mechanisms. These factors contradict the assumptions of homogeneity, and often stationarity, in flood frequency analysis. Here we outline a methodological framework based on clustering using self-organizing maps (SOMs) that allows the linkage of large-scale processes to local-scale observations. The methodology is applied to flood data from several sites in the flood-prone Upper Paraná River basin (UPRB) in southern Brazil. The SOM clustering approach is employed to classify the 6-day rainfall field over the UPRB into four categories, which are then used to classify floods into four types based on the spatiotemporal dynamics of the rainfall field prior to the observed flood events. An analysis of the vertically integrated moisture fluxes, vorticity, and high-level atmospheric circulation revealed that these four clusters are related to known tropical and extratropical processes, including the South American low-level jet (SALLJ); extratropical cyclones; and the South Atlantic Convergence Zone (SACZ). Persistent anomalies in the sea surface temperature fields in the Pacific and Atlantic oceans are also found to be associated with these processes. Floods associated with each cluster present different patterns in terms of frequency, magnitude, spatial variability, scaling, and synchronization of events across the sites and subbasins. These insights suggest new directions for flood risk assessment, forecasting, and management.

Response and recovery measures for two floods in north China during the nineteenth century: a comparative study.

PubMed

Ye, Yu; Fang, Xiuqi; Li, Fan

2016-01-01

The process of human response to natural disasters and its mechanisms as revealed by historical events still has a broad significance for modern society. This study analyzed the disaster relief process and the social response for two floods in China: the Yongding River flood in 1801 and the Yellow River flood in 1841. These two floods reflect the different response processes between the national and provincial capitals during a stage of climate cooling and social transition in the Qing dynasty. Applying methods of historical documents analysis and qualitatively comparative analysis to the materials such as Relief Chronicles Authorized by the Emperor in XinYou and Flood Description in Bian Liang , it shows that: (1) In 1801, the central government took on a lead position, from flood surveying to relief processes. However, local government and gentries played an important role in 1841. (2) In 1801, the government successfully undertook a series of relief measures addressing production, housing, food prices, taxes, and water conservancy and administration. In 1841, the response measures were relatively simple, focusing mainly on providing shelter and food for victims. (3) The government carried out long-term disaster prevention measures such as dredging channels after the flood in 1801. In 1841, however, the efforts were focused mainly on emergency rescue. (4) Refugees in the 1801 flood were effectively managed by a centralized authority. In 1841, regulation of the flooding was delayed by corruption and conflicts between officers, leading to an expansion of the disaster's impact. Above results have led to the conclusion that disaster relief systems and response measures had a significant effect on the consequences of those floods. Various flood relief measures and natural disasters management regimes have implications for contemporary flood hazard mitigation.

Tool for analyzing the vulnerability of buildings to flooding: the case of Switzerland

NASA Astrophysics Data System (ADS)

Choffet, Marc; Bianchi, Renzo; Jaboyedoff, Michel; Kölz, Ehrfried; Lateltin, Olivier; Leroi, Eric; Mayis, Arnaud

2010-05-01

Whatever the way used to protect property exposed to flood, there exists a residual risk. That is what feedbacks of past flooding show. This residual risk is on one hand linked with the possibility that the protection measures may fail or may not work as intended. The residual risk is on the other hand linked with the possibility that the flood exceeds the chosen level of protection.In many European countries, governments and insurance companies are thinking in terms of vulnerability reduction. This publication will present a new tool to evaluate the vulnerability of buildings in a context of flooding. This tool is developed by the project "Analysis of the vulnerability of buildings to flooding" which is funded by the Foundation for Prevention of Cantonal insurances, Switzerland. It is composed by three modules and it aims to provide a method for reducing the vulnerability of buildings to flooding. The first two modules allow identifying all the elements composing the building and listing it. The third module is dedicated to the choice of efficient risk reducing measures on the basis of cost-benefit analyses. The diagnostic tool for different parts of the building is being developed to allow real estate appraisers, insurance companies and homeowners rapidly assess the vulnerability of buildings in flood prone areas. The tool works with by several databases that have been selected from the collection and analysis of data, information, standards and feedback from risk management, hydrology, architecture, construction, materials engineering, insurance, or economy of construction. A method for determining the local hazard is also proposed, to determine the height of potential floods threatening a building, based on a back analysis of Swiss hazard maps. To calibrate the model, seven cantonal insurance institutions participate in the study by providing data, such as the the amount of damage in flooded areas. The poster will present some results from the development of the tool, such as the amount of damages to buildings and the possibility of analysis offered by the tool. Furthermore, analysis of data from the insurance company led to the emergence of trends in costs of damage due to flooding. Some graphics will be presented in the poster to illustrate the tool design. It will be shown that the tool allow for a census of buildings and the awareness of its vulnerability to flooding. A database development explanation concerning the remediation cost measures and the damage costs are also proposed. Simple and innovative remedial measures could be shown in the poster. By the help of some examples it is shown that the tool allows for an investigation of some interesting perspectives in the development of insurance strategies for building stocks in flood prone areas.

75 FR 43998 - Agency Information Collection Activities: Proposed Collection; Comment Request; Revision to...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-27

...; 086-0-27C, Coastal Analysis Form; 086-0-27D, Coastal Structures Form; 086-0-27E, Alluvial Fan Flooding... Analysis Form; 086-0-27D, Coastal Structures Form; 086-0-27E, Alluvial Fan Flooding Form. Abstract: The...-0-27E, Alluvial Fan 150 1 150 1 150 46.65 6,998 Flooding Form. Total 1,500 4,950 17,700 835,839...

The role of flooding in the occurrence of sinkholes in mantled karst setting, Orléans area (France)

NASA Astrophysics Data System (ADS)

Noury, Gildas; Perrin, Jerome; Luu, Li-Hua; Philippe, Pierre

2017-04-01

The Loire River basin is regularly impacted by sinkholes because of its specific geological context constituted of karstic limestone overlain by soft materials. Intense rainfall and associated flooding that occurred in this area in May and June 2016 triggered the collapse of tens of sinkholes. At least 20 houses, one high-traffic road, one levee of the Loire River and one highway were directly threatened. This event highlights not only the vulnerability of the area, especially in the case of a disastrous flood of the Loire River, but also an unexpected kinetic of the process. Two different types of sinkholes occurred in flooded areas: on the plateau, spectacular drop out of former natural caves is suspected; in the Loire valley, flooding is supposed to have accelerated the suffosion of alluvium by a factor of 10 000 to 20 000. This feedback bring new insights on the process dynamics that is currently being analysed in more details using an innovative internal erosion numerical modeling approach, based on Discrete Element - DEM and Lattice Boltzmann methods - LBM. A better understanding of the sinkhole formation is crucial for adequate risk management, especially in the case of a large flooding event.

Seasonal characteristics of flood regimes across the Alpine-Carpathian range.

PubMed

Parajka, J; Kohnová, S; Bálint, G; Barbuc, M; Borga, M; Claps, P; Cheval, S; Dumitrescu, A; Gaume, E; Hlavčová, K; Merz, R; Pfaundler, M; Stancalie, G; Szolgay, J; Blöschl, G

2010-11-17

The aim of this paper is to analyse the differences in the long-term regimes of extreme precipitation and floods across the Alpine-Carpathian range using seasonality indices and atmospheric circulation patterns to understand the main flood-producing processes. This is supported by cluster analyses to identify areas of similar flood processes, both in terms of precipitation forcing and catchment processes. The results allow to isolate regions of similar flood generation processes including southerly versus westerly circulation patterns, effects of soil moisture seasonality due to evaporation and effects of soil moisture seasonality due to snow melt. In many regions of the Alpine-Carpathian range, there is a distinct shift in flood generating processes with flood magnitude as evidenced by a shift from summer to autumn floods. It is argued that the synoptic approach proposed here is valuable in both flood analysis and flood estimation.

Seasonal characteristics of flood regimes across the Alpine–Carpathian range

PubMed Central

Parajka, J.; Kohnová, S.; Bálint, G.; Barbuc, M.; Borga, M.; Claps, P.; Cheval, S.; Dumitrescu, A.; Gaume, E.; Hlavčová, K.; Merz, R.; Pfaundler, M.; Stancalie, G.; Szolgay, J.; Blöschl, G.

2010-01-01

Summary The aim of this paper is to analyse the differences in the long-term regimes of extreme precipitation and floods across the Alpine–Carpathian range using seasonality indices and atmospheric circulation patterns to understand the main flood-producing processes. This is supported by cluster analyses to identify areas of similar flood processes, both in terms of precipitation forcing and catchment processes. The results allow to isolate regions of similar flood generation processes including southerly versus westerly circulation patterns, effects of soil moisture seasonality due to evaporation and effects of soil moisture seasonality due to snow melt. In many regions of the Alpine–Carpathian range, there is a distinct shift in flood generating processes with flood magnitude as evidenced by a shift from summer to autumn floods. It is argued that the synoptic approach proposed here is valuable in both flood analysis and flood estimation. PMID:25067854

Gel-free/label-free proteomic analysis of root tip of soybean over time under flooding and drought stresses.

PubMed

Wang, Xin; Oh, MyeongWon; Sakata, Katsumi; Komatsu, Setsuko

2016-01-01

Growth in the early stage of soybean is markedly inhibited under flooding and drought stresses. To explore the responsive mechanisms of soybean, temporal protein profiles of root tip under flooding and drought stresses were analyzed using gel-free/label-free proteomic technique. Root tip was analyzed because it was the most sensitive organ against flooding, and it was beneficial to root penetration under drought. UDP glucose: glycoprotein glucosyltransferase was decreased and increased in soybean root under flooding and drought, respectively. Temporal protein profiles indicated that fermentation and protein synthesis/degradation were essential in root tip under flooding and drought, respectively. In silico protein-protein interaction analysis revealed that the inductive and suppressive interactions between S-adenosylmethionine synthetase family protein and B-S glucosidase 44 under flooding and drought, respectively, which are related to carbohydrate metabolism. Furthermore, biotin/lipoyl attachment domain containing protein and Class II aminoacyl tRNA/biotin synthetases superfamily protein were repressed in the root tip during time-course stresses. These results suggest that biotin and biotinylation might be involved in energy management to cope with flooding and drought in early stage of soybean-root tip. Copyright © 2015 Elsevier B.V. All rights reserved.

Stream channel cross sections for a reach of the Boise River in Ada County, Idaho

USGS Publications Warehouse

Hortness, Jon E.; Werner, Douglas C.

1999-01-01

The Federal Emergency Management Agency produces maps of areas that are likely to be inundated during major floods, usually the 100-year, or 1-percent probability, flood. The maps, called Flood Insurance Rate Maps, are used to determine flood insurance rates for homes, businesses, or other structures located in flood-prone areas. State and local governments also use these maps for help with, among other things, development planning and disaster mitigation. During the period October 1997 through December 1998, the initial phase of a hydraulic analysis project of the Boise River from Barber Dam to the Ada/Canyon County boundary, the U.S. Geological Survey collected stream channel cross-section data at 238 locations along the river and documented 108 elevation reference marks established for horizontal and vertical control. In the final phase of the project, the Survey will use these data to determine water-surface elevations for the 10-, 50-, 100-, and 500-year floods and to define floodway limits. The Federal Emergency Management Agency will use the results of this hydraulic analysis to update the 100- and 500-year flood boundaries and the floodway limits on their Flood Insurance Rate Maps.

Flood-inundation maps for Lake Champlain in Vermont and in northern Clinton County, New York

USGS Publications Warehouse

Flynn, Robert H.; Hayes, Laura

2016-06-30

Digital flood-inundation maps for an approximately100-mile length of Lake Champlain in Addison, Chittenden, Franklin, and Grand Isle Counties in Vermont and northern Clinton County in New York were created by the U.S. Geological Survey (USGS) in cooperation with the International Joint Commission (IJC). The flood-inundationmaps, which can be accessed through the International Joint Commission (IJC) Web site at http://www.ijc.org/en_/, depict estimates of the areal extent flooding correspondingto selected water levels (stages) at the USGS lake gage on the Richelieu River (Lake Champlain) at Rouses Point, N.Y. (station number 04295000). In this study, wind and seiche effects (standing oscillating wave with a long wavelength) were not taken into account and the flood-inundation mapsreflect 11 stages (elevations) for Lake Champlain that are static for the study length of the lake. Near-real-time stages at this lake gage, and others on Lake Champlain, may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service Advanced Hydrologic Prediction Service at http:/water.weather.gov/ahps/, which also forecasts flood hydrographs at the Richelieu River (Lake Champlain) at Rouses Point.Static flood boundary extents were determined for LakeChamplain in Addison, Chittenden, Franklin, and Grand Isle Counties in Vermont and northern Clinton County in New York using recently acquired (2013–2014) lidar (light detection and ranging) and may be referenced to any of the five USGS lake gages on Lake Champlain. Of these five lakgages, USGS lake gage 04295000, Richelieu River (Lake Champlain) at Rouses Point, N.Y., is the only USGS lake gage that is also a National Weather Service prediction location. Flood boundary extents for the Lake Champlain static flood-inundation map corresponding to the May 201 flood(103.2 feet [ft], National Geodetic Vertical Datum [NGVD] 29) were evaluated by comparing these boundary extents against the inundation area extents determined for the May 2011 flood (which incorporated documented high-water marksfrom the flood of May 201) (Bjerklie and others, 2014).A digital elevation model (DEM) was created by USGS, within a geographic information system (GIS), from the recently flown and processed light detection and ranging(lidar) data (2013–2014) in Vermont and the lake shore area of northern Clinton County in New York. The lidar data have a vertical accuracy of 0.3 to 0.6-ft (9.6 to 18.0-centimeters [cm]) and a horizontal resolution of 2.3 to 4.6 ft (0.7 to 1.4 meters). This DEM was used in determining the floodboundary for 11 flood stages at 0.5-ft intervals from 100.0 to104.0 ft (NGVD 29) and 1-ft intervals from 104.0 to 106.0 ft (NGVD 29) as referenced to the USGS lake gage 04295000, Richelieu River (Lake Champlain) at Rouses Point, N.Y. In addition, the May 2011 flood-inundation area for elevation103.20 ft (NGVD 29) (102.77 ft, North American Vertical Datum [NAVD] 88) was determined from this DEM. The May 2011 flood is the highest recorded lake water level (stage)at the Rouses Point, N.Y., lake gage. Flood stages greater than 101.5 ft (NGVD 29) exceed the “major flood stage”as defined by the NationalWeather Service for USGS lake gage 04295000.The availability of these maps, along with Internet information regarding current stage from the USGS lake gage and forecasted high-flow stages from the NationalWeather Service, will provide emergency management personnel and residents with information that is critical for flood responseactivities such as evacuations and road closures, as well as for post-flood recovery eforts.

Attenuation of Storm Surge Flooding By Wetlands in the Chesapeake Bay: An Integrated Geospatial Framework Evaluating Impacts to Critical Infrastructure

NASA Astrophysics Data System (ADS)

Khalid, A.; Haddad, J.; Lawler, S.; Ferreira, C.

2014-12-01

Areas along the Chesapeake Bay and its tributaries are extremely vulnerable to hurricane flooding, as evidenced by the costly effects and severe impacts of recent storms along the Virginia coast, such as Hurricane Isabel in 2003 and Hurricane Sandy in 2012. Coastal wetlands, in addition to their ecological importance, are expected to mitigate the impact of storm surge by acting as a natural protection against hurricane flooding. Quantifying such interactions helps to provide a sound scientific basis to support planning and decision making. Using storm surge flooding from various historical hurricanes, simulated using a coupled hydrodynamic wave model (ADCIRC-SWAN), we propose an integrated framework yielding a geospatial identification of the capacity of Chesapeake Bay wetlands to protect critical infrastructure. Spatial identification of Chesapeake Bay wetlands is derived from the National Wetlands Inventory (NWI), National Land Cover Database (NLCD), and the Coastal Change Analysis Program (C-CAP). Inventories of population and critical infrastructure are extracted from US Census block data and FEMA's HAZUS-Multi Hazard geodatabase. Geospatial and statistical analyses are carried out to develop a relationship between wetland land cover, hurricane flooding, population and infrastructure vulnerability. These analyses result in the identification and quantification of populations and infrastructure in flooded areas that lie within a reasonable buffer surrounding the identified wetlands. Our analysis thus produces a spatial perspective on the potential for wetlands to attenuate hurricane flood impacts in critical areas. Statistical analysis will support hypothesis testing to evaluate the benefits of wetlands from a flooding and storm-surge attenuation perspective. Results from geospatial analysis are used to identify where interactions with critical infrastructure are relevant in the Chesapeake Bay.

Near real time Forensic Disaster Analysis of the central European flood in June 2013 in Germany: Impact and management

NASA Astrophysics Data System (ADS)

Khazai, Bijan; Bessel, Tina; Möhrle, Stella; Dittrich, André; Schröter, Kai; Mühr, Bernhard; Elmer, Florian; Kunz-Plapp, Tina; Trieselmann, Werner; Kunz, Michael

2014-05-01

Within its current research activity on near real time Forensic Disaster Analysis (FDA), researchers from the Center for Disaster Management and Risk Reduction Technology (CEDIM) aim to identify major risk drivers and to understand the root causes of disaster and infer the implications for disaster mitigation. A key component of this activity is the development of rapid assessment tools which allow for a science based estimate of disaster impacts. The central European flood in June 2013 caused in Germany severe damage to buildings, infrastructure and agricultural lands and has had a great impact on people, transportation and the economy. In many areas thousands of people were evacuated. Electrical grid and local water supply utilities failed during the floods. Furthermore, traffic was disrupted in the interregional transportation network including federal highways and long distance railways. CEDIM analysed the impact and management of the flood event within an FDA activity. An analysis on the amount and spatial distribution of flood-related Twitter messages in Germany revealed a high interest in the flood in the social media. Furthermore, an analysis of the resilience of selected affected areas in Germany has been carried out to assess the impact of the flood on the district level. The resilience indicator is based on social, economic and institutional indicators which are supplemented with information on the number of people evacuated and transportation disruptions. Combined with the magnitude of the event, an index is calculated that allows for a rapid initial but preliminary estimate of the flood impact. Results show high resilience of the administrative districts along the Danube while heavy impacts are seen along the Mulde and Elbe.

Prediction of River Flooding using Geospatial and Statistical Analysis in New York, USA and Kent, UK

NASA Astrophysics Data System (ADS)

Marsellos, A.; Tsakiri, K.; Smith, M.

2014-12-01

Flooding in the rivers normally occurs during periods of excessive precipitation (i.e. New York, USA; Kent, UK) or ice jams during the winter period (New York, USA). For the prediction and mapping of the river flooding, it is necessary to evaluate the spatial distribution of the water (volume) in the river as well as study the interaction between the climatic and hydrological variables. Two study areas have been analyzed; one in Mohawk River, New York and one in Kent, United Kingdom (UK). A high resolution Digital Elevation Model (DEM) of the Mohawk River, New York has been used for a GIS flooding simulation to determine the maximum elevation value of the water that cannot continue to be restricted in the trunk stream and as a result flooding in the river may be triggered. The Flooding Trigger Level (FTL) is determined by incremental volumetric and surface calculations from Triangulated Irregular Network (TIN) with the use of GIS software and LiDAR data. The prediction of flooding in the river can also be improved by the statistical analysis of the hydrological and climatic variables in Mohawk River and Kent, UK. A methodology of time series analysis has been applied for the decomposition of the hydrological (water flow and ground water data) and climatic data in both locations. The KZ (Kolmogorov-Zurbenko) filter is used for the decomposition of the time series into the long, seasonal, and short term components. The explanation of the long term component of the water flow using the climatic variables has been improved up to 90% for both locations. Similar analysis has been performed for the prediction of the seasonal and short term component. This methodology can be applied for flooding of the rivers in multiple sites.

The NASA Applied Science Program Disasters Area: Disaster Applications Research and Response

NASA Astrophysics Data System (ADS)

Murray, J. J.; Lindsay, F. E.; Stough, T.; Jones, C. E.

2014-12-01

The goal of the Natural Disaster Application Area is to use NASA's capabilities in spaceborne, airborne, surface observations, higher-level derived data products, and modeling and data analysis to improve natural disaster forecasting, mitigation, and response. The Natural Disaster Application Area applies its remote sensing observations, modeling and analysis capabilities to provide hazard and disaster information where and when it is needed. Our application research activities specifically contribute to 1) Understanding the natural processes that produce hazards, 2)Developing hazard mitigation technologies, and 3)Recognizing vulnerability of interdependent critical infrastructure. The Natural Disasters Application area selects research projects through a rigorous, impartial peer-review process that address a broad spectrum of disasters which afflict populations within the United States, regionally and globally. Currently there are 19 active projects in the research portfolio which address the detection, characterization, forecasting and response to a broad range of natural disasters including earthquakes, tsunamis, volcanic eruptions and ash dispersion, wildfires, hurricanes, floods, tornado damage assessment, oil spills and disaster data mining. The Disasters team works with federal agencies to aid the government in meeting the challenges associated with natural disaster response and to transfer technologies to agencies as they become operational. Internationally, the Disasters Area also supports the Committee on Earth Observations Working Group on Disasters, and the International Charter on Space and Disasters to increase, strengthen, and coordinate contributions of NASA Earth-observing satellites and applications products to disaster risk management. The CEOS group will lead pilot efforts focused on identifying key systems to support flooding, earthquake, and volcanic events.

Linking Hydro-Meteorological Hazards, Climate and Food Security: an Initiative of International Scientific Community

NASA Astrophysics Data System (ADS)

Ismail-Zadeh, A.; Beer, T.

2013-05-01

Humans face climatic and hydro-meteorological hazards on different scales in time and space. In particular natural hazards can have disastrous impact in the short term (flood) and in the long term (drought) as they affect human life and health as well as impacting dramatically on the sustainable development of society. They represent a pending danger for vulnerable lifelines, infrastructure and the agricultural systems that depend on the water supply, reservoirs, pipelines, and power plants. Developed countries are affected, but the impact is disproportionate within the developing world. Extreme natural events such as extreme floods or prolonged drought can change the life and economic development of developing nations and stifle their development for decades. The beginning of the XX1st century has been marked by a significant number of natural disasters, such as floods, severe storms, wildfires, hurricanes, and tsunamis. Extreme natural events cause devastation resulting in loss of human life, large environmental damage, and partial or total loss of infrastructure that, in the longer time, will affect the potential for agricultural recovery. Recent catastrophic events of the early 21st century (e.g. floods in Pakistan and Thailand, the 2011 Tohoku earthquake and tsunami) remind us once again that there is a strong coupling between complex solid Earth, oceanic, and atmospheric processes and that even developed countries such as Japan are subject to agricultural declines as a result of disastrous hydro-meteorological events. Scientific community recognizes that communication between the groups of experts of various international organizations dealing with natural hazards and their activity in disaster risk reduction and food security needs to be strengthened. Several international scientific unions and intergovernmental institutions set up a consortium of experts to promote studies of weather, climate and their interaction with agriculture, food and their socio-economic consequence.

Assessment of Three Flood Hazard Mapping Methods: A Case Study of Perlis

NASA Astrophysics Data System (ADS)

Azizat, Nazirah; Omar, Wan Mohd Sabki Wan

2018-03-01

Flood is a common natural disaster and also affect the all state in Malaysia. Regarding to Drainage and Irrigation Department (DID) in 2007, about 29, 270 km2 or 9 percent of region of the country is prone to flooding. Flood can be such devastating catastrophic which can effected to people, economy and environment. Flood hazard mapping can be used is an important part in flood assessment to define those high risk area prone to flooding. The purposes of this study are to prepare a flood hazard mapping in Perlis and to evaluate flood hazard using frequency ratio, statistical index and Poisson method. The six factors affecting the occurrence of flood including elevation, distance from the drainage network, rainfall, soil texture, geology and erosion were created using ArcGIS 10.1 software. Flood location map in this study has been generated based on flooded area in year 2010 from DID. These parameters and flood location map were analysed to prepare flood hazard mapping in representing the probability of flood area. The results of the analysis were verified using flood location data in year 2013, 2014, 2015. The comparison result showed statistical index method is better in prediction of flood area rather than frequency ratio and Poisson method.

Attribution of regional flood changes based on scaling fingerprints

PubMed Central

Merz, Bruno; Viet Dung, Nguyen; Parajka, Juraj; Nester, Thomas; Blöschl, Günter

2016-01-01

Abstract Changes in the river flood regime may be due to atmospheric processes (e.g., increasing precipitation), catchment processes (e.g., soil compaction associated with land use change), and river system processes (e.g., loss of retention volume in the floodplains). This paper proposes a new framework for attributing flood changes to these drivers based on a regional analysis. We exploit the scaling characteristics (i.e., fingerprints) with catchment area of the effects of the drivers on flood changes. The estimation of their relative contributions is framed in Bayesian terms. Analysis of a synthetic, controlled case suggests that the accuracy of the regional attribution increases with increasing number of sites and record lengths, decreases with increasing regional heterogeneity, increases with increasing difference of the scaling fingerprints, and decreases with an increase of their prior uncertainty. The applicability of the framework is illustrated for a case study set in Austria, where positive flood trends have been observed at many sites in the past decades. The individual scaling fingerprints related to the atmospheric, catchment, and river system processes are estimated from rainfall data and simple hydrological modeling. Although the distributions of the contributions are rather wide, the attribution identifies precipitation change as the main driver of flood change in the study region. Overall, it is suggested that the extension from local attribution to a regional framework, including multiple drivers and explicit estimation of uncertainty, could constitute a similar shift in flood change attribution as the extension from local to regional flood frequency analysis. PMID:27609996

The relationship between precipitation and insurance data for floods in a Mediterranean region (northeast Spain)

NASA Astrophysics Data System (ADS)

Cortès, Maria; Turco, Marco; Llasat-Botija, Montserrat; Llasat, Maria Carmen

2018-03-01

Floods in the Mediterranean region are often surface water floods, in which intense precipitation is usually the main driver. Determining the link between the causes and impacts of floods can make it easier to calculate the level of flood risk. However, up until now, the limitations in quantitative observations for flood-related damages have been a major obstacle when attempting to analyse flood risk in the Mediterranean. Flood-related insurance damage claims for the last 20 years could provide a proxy for flood impact, and this information is now available in the Mediterranean region of Catalonia, in northeast Spain. This means a comprehensive analysis of the links between flood drivers and impacts is now possible. The objective of this paper is to develop and evaluate a methodology to estimate flood damages from heavy precipitation in a Mediterranean region. Results show that our model is able to simulate the probability of a damaging event as a function of precipitation. The relationship between precipitation and damage provides insights into flood risk in the Mediterranean and is also promising for supporting flood management strategies.

Beyond 'flood hotspots': Modelling emergency service accessibility during flooding in York, UK

NASA Astrophysics Data System (ADS)

Coles, Daniel; Yu, Dapeng; Wilby, Robert L.; Green, Daniel; Herring, Zara

2017-03-01

This paper describes the development of a method that couples flood modelling with network analysis to evaluate the accessibility of city districts by emergency responders during flood events. We integrate numerical modelling of flood inundation with geographical analysis of service areas for the Ambulance Service and the Fire & Rescue Service. The method was demonstrated for two flood events in the City of York, UK to assess the vulnerability of care homes and sheltered accommodation. We determine the feasibility of emergency services gaining access within the statutory 8- and 10-min targets for high-priority, life-threatening incidents 75% of the time, during flood episodes. A hydrodynamic flood inundation model (FloodMap) simulates the 2014 pluvial and 2015 fluvial flood events. Predicted floods (with depth >25 cm and areas >100 m2) were overlain on the road network to identify sites with potentially restricted access. Accessibility of the city to emergency responders during flooding was quantified and mapped using; (i) spatial coverage from individual emergency nodes within the legislated timeframes, and; (ii) response times from individual emergency service nodes to vulnerable care homes and sheltered accommodation under flood and non-flood conditions. Results show that, during the 2015 fluvial flood, the area covered by two of the three Fire & Rescue Service stations reduced by 14% and 39% respectively, while the remaining station needed to increase its coverage by 39%. This amounts to an overall reduction of 6% and 20% for modelled and observed floods respectively. During the 2014 surface water flood, 7 out of 22 care homes (32%) and 15 out of 43 sheltered accommodation nodes (35%) had modelled response times above the 8-min threshold from any Ambulance station. Overall, modelled surface water flooding has a larger spatial footprint than fluvial flood events. Hence, accessibility of emergency services may be impacted differently depending on flood mechanism. Moreover, we expect emergency services to face greater challenges under a changing climate with a growing, more vulnerable population. The methodology developed in this study could be applied to other cities, as well as for scenario-based evaluation of emergency preparedness to support strategic decision making, and in real-time forecasting to guide operational decisions where heavy rainfall lead-time and spatial resolution are sufficient.

Estimated flood-inundation maps for Cowskin Creek in western Wichita, Kansas

USGS Publications Warehouse

Studley, Seth E.

2003-01-01

The October 31, 1998, flood on Cowskin Creek in western Wichita, Kansas, caused millions of dollars in damages. Emergency management personnel and flood mitigation teams had difficulty in efficiently identifying areas affected by the flooding, and no warning was given to residents because flood-inundation information was not available. To provide detailed information about future flooding on Cowskin Creek, high-resolution estimated flood-inundation maps were developed using geographic information system technology and advanced hydraulic analysis. Two-foot-interval land-surface elevation data from a 1996 flood insurance study were used to create a three-dimensional topographic representation of the study area for hydraulic analysis. The data computed from the hydraulic analyses were converted into geographic information system format with software from the U.S. Army Corps of Engineers' Hydrologic Engineering Center. The results were overlaid on the three-dimensional topographic representation of the study area to produce maps of estimated flood-inundation areas and estimated depths of water in the inundated areas for 1-foot increments on the basis of stream stage at an index streamflow-gaging station. A Web site (http://ks.water.usgs.gov/Kansas/cowskin.floodwatch) was developed to provide the public with information pertaining to flooding in the study area. The Web site shows graphs of the real-time streamflow data for U.S. Geological Survey gaging stations in the area and monitors the National Weather Service Arkansas-Red Basin River Forecast Center for Cowskin Creek flood-forecast information. When a flood is forecast for the Cowskin Creek Basin, an estimated flood-inundation map is displayed for the stream stage closest to the National Weather Service's forecasted peak stage. Users of the Web site are able to view the estimated flood-inundation maps for selected stages at any time and to access information about this report and about flooding in general. Flood recovery teams also have the ability to view the estimated flood-inundation map pertaining to the most recent flood. The availability of these maps and the ability to monitor the real-time stream stage through the U.S. Geological Survey Web site provide emergency management personnel and residents with information that is critical for evacuation and rescue efforts in the event of a flood as well as for post-flood recovery efforts.

Analysis of present and future potential compound flooding risk along the European coast

NASA Astrophysics Data System (ADS)

Bevacqua, Emanuele; Maraun, Douglas; Voukouvalas, Evangelos; Vousdoukas, Michalis I.; Widmann, Martin; Manning, Colin; Vrac, Mathieu

2017-04-01

The coastal zone is the natural border between the sea and the mainland, and it is constantly under the influence of marine and land-based natural and human-induced pressure. Compound floods are extreme events occurring in coastal areas where the interaction of joint high sea level and large amount of precipitation causes extreme floodings. Typically the risk of flooding in coastal areas is defined analysing either sea level or precipitation driven floodings, however compound floods should be considered to avoid an underestimation of the risk. In the future, the human pressure at the coastal zone is expected to increase, urging for a comprehensive analysis of the compound flooding risk under different climate change scenarios. In this study we introduce the concept of "potential risk" as we investigate how often large amount of precipitation and high sea level may co-occur, and not the effective impact due to the interaction of these two hazards. The effective risk of compound flooding in a specific place depends also on the local orography and on the existing protections. The estimation of the potential risk of compound flooding is useful to individuate places where an effective risk of compound flooding may exist, and where further studies would be useful to get more precise information on the local risk. We estimate the potential risk of compound flooding along the European coastal zone incorporating the ERA-Interim meteorological reanalysis for the past and present state, and the future projections from two RCP scenarios (namely the RCP4.5 and RCP8.5 scenarios) as derived from 8 CMIP5 models of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Sea level data are estimated by forcing the hydrodynamic model Delft3D-Flow with 6-hourly wind and atmospheric pressure fields. Based on sea level (storm surge and astronomical tide) and precipitation joint occurrence analysis, a map of the potential compound flooding risk along the European coast is proposed and critical places with high potential risk are identified. For these critical places, we plan to asses the potential compound flood risk driven by coinciding extreme values of sea level and river discharge. Finally, we analyse the atmospheric large scale processes that lead to compound floods and their variation under future climate change scenarios.

Socio-Economic Appraisal of Flood Hazard among the Riparian Communities: Case Study of Brahmaputra Valley in Assam; India

NASA Astrophysics Data System (ADS)

Roy, Nikhil; Wasini Pandey, Bindhy

2017-04-01

Brahmaputra valley of Assam is one of the most hazard prone areas of the Indian subcontinent. Recurring floods have severely affected the riparian communities of the region since time immemorial. But, the frequency of the problem has been intensified after the great earthquakes of 1897 and 1950. These two extreme earthquakes have disturbed the geological setting of the basin and the channel morphology has been altered henceforth. The impact of floods on riparian communities in Brahmaputra valley has been abysmal. During the monsoon season almost 30 per cent of the valley has been inundated with floods and the riparian communities are mostly affected. Large chunk of people have been uprooted from their native lands due to recurring floods in the low lying areas of the region. Although it is impossible to quantify the human tragedy during the natural disasters, but one can easily understand the situation by the facts that about 1.8 million people and 200,000 hectares of farmland were affected in the 2016 floods of Assam. In the present study, an attempt has been made to assess the spatio-temporal changes of the morphology of Brahmaputra River and its impact on the livelihood of the riparian communities. For that, LANDSAT and SENTINEL imageries have been used to examine the shifting of bank lines of three decades. CARTOSAT DEM has been used to prepare the FLOOD HAZARD ZONATION map of the Brahmaputra valley to examine the flood vulnerable areas of the region. The present study also tries to explain the livelihood condition of the Internally Displaced Persons and their social cohesion. Keywords: Brahmaputra River, Flood, LANDSAT, CARTOSAT DEM, FLOOD HAZARD ZONATION, Riparian Communities

Supercontinental warming of the mantle at the origin of gigantic flood basalts

NASA Astrophysics Data System (ADS)

Coltice, N.; Phillips, B. R.; Bertrand, H.; Ricard, Y.; Rey, P.

2006-12-01

Continents episodically cluster together into a supercontinent, eventually breaking up with intense magmatic activity supposedly causedby mantle plumes. The break-up of Pangea, the last supercontinent, was accompanied by the emplacement of the largest known continental flood basalt, the Central Atlantic Magmatic Province, causing massive extinctions at the Triassic/Jurassic boundary. However, there is little support for a plume origin for this catastrophic event. On the basis of 2D and 3D spherical convection modelling in a internally heated mantle, we show that continental aggregation leads to large-scale melting without requiring the involvement of plumes. When only internal heat sources in the mantle are considered, the formationof a supercontinent causes the enlargement of the wavelength of the flow and a subcontinental warming as large as 100^{\\mboxo}C. This temperature increase may lead to large- scale melting without the involvment of plumes. Our results suggest the existence of two distinct types of continental flood basalts, caused by plume or by supercontinental warming. We review some potential candidates for our proposed model.

Global warming of the mantle at the origin of flood basalts over supercontinents

NASA Astrophysics Data System (ADS)

Coltice, N.; Phillips, B. R.; Bertrand, H.; Ricard, Y.; Rey, P.

2007-05-01

Continents episodically cluster together into a supercontinent, eventually breaking up with intense magmatic activity supposedly caused by mantle plumes (Morgan, 1983; Richards et al., 1989; Condie, 2004). The breakup of Pangea, the last supercontinent, was accompanied by the emplacement of the largest known continental flood basalt, the Central Atlantic Magmatic Province, which caused massive extinctions at the Triassic-Jurassic boundary (Marzoli et al., 1999). However, there is little support for a plume origin for this catastrophic event (McHone, 2000). On the basis of convection modeling in an internally heated mantle, this paper shows that continental aggregation promotes large-scale melting without requiring the involvement of plumes. When only internal heat sources in the mantle are considered, the formation of a supercontinent causes the enlargement of flow wavelength and a subcontinental increase in temperature as large as 100 °C. This temperature increase may lead to large-scale melting without the involvement of plumes. Our results suggest the existence of two distinct types of continental flood basalts, caused by plume or by mantle global warming.

The framing of two major flood episodes in the Irish print news media: Implications for societal adaptation to living with flood risk.

PubMed

Devitt, Catherine; O'Neill, Eoin

2017-10-01

Societal adaptation to flooding is a critical component of contemporary flood policy. Using content analysis, this article identifies how two major flooding episodes (2009 and 2014) are framed in the Irish broadsheet news media. The article considers the extent to which these frames reflect shifts in contemporary flood policy away from protection towards risk management, and the possible implications for adaptation to living with flood risk. Frames help us make sense of the social world, and within the media, framing is an essential tool for communication. Five frames were identified: flood resistance and structural defences, politicisation of flood risk, citizen as risk manager, citizen as victim and emerging trade-offs. These frames suggest that public debates on flood management do not fully reflect shifts in contemporary flood policy, with negative implications for the direction of societal adaptation. Greater discussion is required on the influence of the media on achieving policy objectives.

New Orleans after Hurricane Katrina

NASA Image and Video Library

2005-09-08

JSC2005e37990 (8 September 2005) --- Flooding of large sections of I-610 and the I-610/I-10 interchange (center) are visible to the east of the 17th Street Canal in this image acquired on September 8, 2005 from the International Space Station. Flooded regions are dark greenish brown, while dry areas are light brown to tan. North is to top of image, which was cropped from the digital still camera's original frame, ISS011-E-12527.

The Use of Hydrograph Analysis and Impulse Response Functions to Improve Understanding of Groundwater Flooding: A Case Study from the Chalk Aquifer, United Kingdom.

NASA Astrophysics Data System (ADS)

Ascott, M.; Bloomfield, J.; Macdonald, D.; Marchant, B.; McKenzie, A.

2017-12-01

The Cretaceous Chalk, the most important aquifer in the United Kingdom (UK) for public water supply, underlies many large cities in southern and eastern England including parts of London, however, it is prone to groundwater flooding. We have developed a new approach to analyse the spatio-temporal extent of groundwater flooding using statistical analysis of groundwater level hydrographs and impulse response functions (IRFs) applied to a major Chalk groundwater flooding event in the UK during winter 2013/14. Using monthly groundwater levels for 26 boreholes in the Chalk and a new standardised index for groundwater flooding, we have: estimated standardised series; grouped them using k-means cluster analysis; and, cross-correlated the cluster centroids with the Standardised Precipitation Index accumulated over time intervals between 1 and 60 months. This analysis reveals two spatially coherent groups of standardised hydrographs which respond to precipitation over different timescales. We estimate IRF models of the groundwater level response to effective precipitation for three boreholes in each group. The IRF models support the SPI analysis showing different response functions between the two groups. If we apply identical effective precipitation inputs to each of the IRF models we see differences between the hydrographs from each group. It is proposed that these differences are due to the intrinsic, hydrogeological properties of the Chalk and of overlying relatively low permeability superficial deposits. Consequently, it is concluded that the overarching controls on groundwater flood response are a complex combination of antecedent conditions, rainfall and catchment hydrogeological properties. These controls should be taken into consideration when anticipating and managing future groundwater flood events.

Making Supply Chains Resilient to Floods Using a Bayesian Network

NASA Astrophysics Data System (ADS)

Haraguchi, M.

2015-12-01

Natural hazards distress the global economy by disrupting the interconnected supply chain networks. Manufacturing companies have created cost-efficient supply chains by reducing inventories, streamlining logistics and limiting the number of suppliers. As a result, today's supply chains are profoundly susceptible to systemic risks. In Thailand, for example, the GDP growth rate declined by 76 % in 2011 due to prolonged flooding. Thailand incurred economic damage including the loss of USD 46.5 billion, approximately 70% of which was caused by major supply chain disruptions in the manufacturing sector. Similar problems occurred after the Great East Japan Earthquake and Tsunami in 2011, the Mississippi River floods and droughts during 2011 - 2013, and Hurricane Sandy in 2012. This study proposes a methodology for modeling supply chain disruptions using a Bayesian network analysis (BNA) to estimate expected values of countermeasures of floods, such as inventory management, supplier management and hard infrastructure management. We first performed a spatio-temporal correlation analysis between floods and extreme precipitation data for the last 100 years at a global scale. Then we used a BNA to create synthetic networks that include variables associated with the magnitude and duration of floods, major components of supply chains and market demands. We also included decision variables of countermeasures that would mitigate potential losses caused by supply chain disruptions. Finally, we conducted a cost-benefit analysis by estimating the expected values of these potential countermeasures while conducting a sensitivity analysis. The methodology was applied to supply chain disruptions caused by the 2011 Thailand floods. Our study demonstrates desirable typical data requirements for the analysis, such as anonymized supplier network data (i.e. critical dependencies, vulnerability information of suppliers) and sourcing data(i.e. locations of suppliers, and production rates and volume), and data from previous experiences (i.e. companies' risk mitigation strategy decisions).

Stream network analysis and geomorphic flood plain mapping from orbital and suborbital remote sensing imagery application to flood hazard studies in central Texas

NASA Technical Reports Server (NTRS)

Baker, V. R. (Principal Investigator); Holz, R. K.; Hulke, S. D.; Patton, P. C.; Penteado, M. M.

1975-01-01

The author has identified the following significant results. Development of a quantitative hydrogeomorphic approach to flood hazard evaluation was hindered by (1) problems of resolution and definition of the morphometric parameters which have hydrologic significance, and (2) mechanical difficulties in creating the necessary volume of data for meaningful analysis. Measures of network resolution such as drainage density and basin Shreve magnitude indicated that large scale topographic maps offered greater resolution than small scale suborbital imagery and orbital imagery. The disparity in network resolution capabilities between orbital and suborbital imagery formats depends on factors such as rock type, vegetation, and land use. The problem of morphometric data analysis was approached by developing a computer-assisted method for network analysis. The system allows rapid identification of network properties which can then be related to measures of flood response.

A Study on Active Disaster Management System for Standardized Emergency Action Plan using BIM and Flood Damage Estimation Techniques

NASA Astrophysics Data System (ADS)

Jeong, C.; Om, J.; Hwang, J.; Joo, K.; Heo, J.

2013-12-01

In recent, the frequency of extreme flood has been increasing due to climate change and global warming. Highly flood damages are mainly caused by the collapse of flood control structures such as dam and dike. In order to reduce these disasters, the disaster management system (DMS) through flood forecasting, inundation mapping, EAP (Emergency Action Plan) has been studied. The estimation of inundation damage and practical EAP are especially crucial to the DMS. However, it is difficult to predict inundation and take a proper action through DMS in real emergency situation because several techniques for inundation damage estimation are not integrated and EAP is supplied in the form of a document in Korea. In this study, the integrated simulation system including rainfall frequency analysis, rainfall-runoff modeling, inundation prediction, surface runoff analysis, and inland flood analysis was developed. Using this system coupled with standard GIS data, inundation damage can be estimated comprehensively and automatically. The standard EAP based on BIM (Building Information Modeling) was also established in this system. It is, therefore, expected that the inundation damages through this study over the entire area including buildings can be predicted and managed.

Magnitude and frequency of floods in western Oregon

USGS Publications Warehouse

Harris, David Dell; Hubbard, Larry L.; Hubbard, Lawrence E.

1979-01-01

A method for estimating the magnitude and frequency of floods is presented for unregulated streams in western Oregon. Equations relating flood magnitude to basin characteristics were developed for exceedance probabilities of 0.5 to 0.01 (2- to 100-year recurrence intervals). Separate equations are presented for four regions: Coast, Willamette, Rogue-Umpqua, and High Cascades. Also presented are values of flood discharges for selected exceedance probabilities and of basin characteristics for all gaging stations used in the analysis. Included are data for 230 stations in Oregon, 6 stations in southwestern Washington, and 3 stations in northwestern California. Drainage areas used in the analysis range from 0.21 to 7,280 square miles. Also included are maximum discharges for all western Oregon stations used in the analysis. (Woodard-USGS)

Uncertainties in future-proof decision-making: the Dutch Delta Model

NASA Astrophysics Data System (ADS)

IJmker, Janneke; Snippen, Edwin; Ruijgh, Erik

2013-04-01

In 1953, a number of European countries experienced flooding after a major storm event coming from the northwest. Over 2100 people died of the resulting floods, 1800 of them being Dutch. This gave rise to the development of the so-called Delta Works and Zuiderzee Works that strongly reduced the flood risk in the Netherlands. These measures were a response to a large flooding event. As boundary conditions have changed (increasing population, increasing urban development, etc.) , the flood risk should be evaluated continuously, and measures should be taken if necessary. The Delta Programme was designed to be prepared for future changes and to limit the flood risk, taking into account economics, nature, landscape, residence and recreation . To support decisions in the Delta Programme, the Delta Model was developed. By using four different input scenarios (extremes in climate and economics) and variations in system setup, the outcomes of the Delta Model represent a range of possible outcomes for the hydrological situation in 2050 and 2100. These results flow into effect models that give insight in the integrated effects on freshwater supply (including navigation, industry and ecology) and flood risk. As the long-term water management policy of the Netherlands for the next decades will be based on these results, they have to be reliable. Therefore, a study was carried out to investigate the impact of uncertainties on the model outcomes. The study focused on "known unknowns": uncertainties in the boundary conditions, in the parameterization and in the model itself. This showed that for different parts of the Netherlands, the total uncertainty is in the order of meters! Nevertheless, (1) the total uncertainty is dominated by uncertainties in boundary conditions. Internal model uncertainties are subordinate to that. Furthermore, (2) the model responses develop in a logical way, such that the exact model outcomes might be uncertain, but the outcomes of different model runs are reliable relative to each other. The Delta Model therefore is a reliable instrument for finding the optimal water management policy for the future. As the exact model outcomes show a high degree of uncertainty, the model analysis will be on a large numbers of model runs to gain insight in the sensitivity of the model for different setups and boundary conditions. The results allow fast investigation of (relative) effects of measures. Furthermore, it helps to identify bottlenecks in the system. To summarize, the Delta Model is a tool for policy makers to base their policy strategies on quantitative rather than qualitative information. It can be applied to the current and future situation, and feeds the political discussion. The uncertainty of the model has no determinative effect on the analysis that can be done by the Delta Model.

Estimating the long-term historic evolution of exposure to flooding of coastal populations

NASA Astrophysics Data System (ADS)

Stevens, A. J.; Clarke, D.; Nicholls, R. J.; Wadey, M. P.

2015-06-01

Coastal managers face the task of assessing and managing flood risk. This requires knowledge of the area of land, the number of people, properties and other infrastructure potentially affected by floods. Such analyses are usually static; i.e. they only consider a snapshot of the current situation. This misses the opportunity to learn about the role of key drivers of historical changes in flood risk, such as development and population rise in the coastal flood plain, as well as sea-level rise. In this paper, we develop and apply a method to analyse the temporal evolution of residential population exposure to coastal flooding. It uses readily available data in a GIS environment. We examine how population and sea-level change have modified exposure over two centuries in two neighbouring coastal sites: Portsea and Hayling Islands on the UK south coast. The analysis shows that flood exposure changes as a result of increases in population, changes in coastal population density and sea level rise. The results indicate that to date, population change is the dominant driver of the increase in exposure to flooding in the study sites, but climate change may outweigh this in the future. A full analysis of changing flood risk is not possible as data on historic defences and wider vulnerability are not available. Hence, the historic evolution of flood exposure is as close as we can get to a historic evolution of flood risk. The method is applicable anywhere that suitable floodplain geometry, sea level and population data sets are available and could be widely applied, and will help inform coastal managers of the time evolution in coastal flood drivers.

Association between flood and the morbidity of bacillary dysentery in Zibo City, China: a symmetric bidirectional case-crossover study

NASA Astrophysics Data System (ADS)

Zhang, Feifei; Ding, Guoyong; Liu, Zhidong; Zhang, Caixia; Jiang, Baofa

2016-12-01

This study examined the relationship between daily morbidity of bacillary dysentery and flood in 2007 in Zibo City, China, using a symmetric bidirectional case-crossover study. Odds ratios (ORs) and 95 % confidence intervals (CIs) on the basis of multivariate model and stratified analysis at different lagged days were calculated to estimate the risk of flood on bacillary dysentery. A total of 902 notified bacillary dysentery cases were identified during the study period. The median of case distribution was 7-year-old and biased to children. Multivariable analysis showed that flood was associated with an increased risk of bacillary dysentery, with the largest OR of 1.849 (95 % CI 1.229-2.780) at 2-day lag. Gender-specific analysis showed that there was a significant association between flood and bacillary dysentery among males only (ORs >1 from lag 1 to lag 5), with the strongest lagged effect at 2-day lag (OR = 2.820, 95 % CI 1.629-4.881), and the result of age-specific indicated that youngsters had a slightly larger risk to develop flood-related bacillary dysentery than older people at one shorter lagged day (OR = 2.000, 95 % CI 1.128-3.546 in youngsters at lag 2; OR = 1.879, 95 % CI 1.069-3.305 in older people at lag 3). Our study has confirmed that there is a positive association between flood and the risk of bacillary dysentery in selected study area. Males and youngsters may be the vulnerable and high-risk populations to develop the flood-related bacillary dysentery. Results from this study will provide recommendations to make available strategies for government to deal with negative health outcomes due to floods.

Association between flood and the morbidity of bacillary dysentery in Zibo City, China: a symmetric bidirectional case-crossover study.

PubMed

Zhang, Feifei; Ding, Guoyong; Liu, Zhidong; Zhang, Caixia; Jiang, Baofa

2016-12-01

This study examined the relationship between daily morbidity of bacillary dysentery and flood in 2007 in Zibo City, China, using a symmetric bidirectional case-crossover study. Odds ratios (ORs) and 95 % confidence intervals (CIs) on the basis of multivariate model and stratified analysis at different lagged days were calculated to estimate the risk of flood on bacillary dysentery. A total of 902 notified bacillary dysentery cases were identified during the study period. The median of case distribution was 7-year-old and biased to children. Multivariable analysis showed that flood was associated with an increased risk of bacillary dysentery, with the largest OR of 1.849 (95 % CI 1.229-2.780) at 2-day lag. Gender-specific analysis showed that there was a significant association between flood and bacillary dysentery among males only (ORs >1 from lag 1 to lag 5), with the strongest lagged effect at 2-day lag (OR = 2.820, 95 % CI 1.629-4.881), and the result of age-specific indicated that youngsters had a slightly larger risk to develop flood-related bacillary dysentery than older people at one shorter lagged day (OR = 2.000, 95 % CI 1.128-3.546 in youngsters at lag 2; OR = 1.879, 95 % CI 1.069-3.305 in older people at lag 3). Our study has confirmed that there is a positive association between flood and the risk of bacillary dysentery in selected study area. Males and youngsters may be the vulnerable and high-risk populations to develop the flood-related bacillary dysentery. Results from this study will provide recommendations to make available strategies for government to deal with negative health outcomes due to floods.

Uncertainty Analysis of A Flood Risk Mapping Procedure Applied In Urban Areas

NASA Astrophysics Data System (ADS)

Krause, J.; Uhrich, S.; Bormann, H.; Diekkrüger, B.

In the framework of IRMA-Sponge program the presented study was part of the joint research project FRHYMAP (flood risk and hydrological mapping). A simple con- ceptual flooding model (FLOODMAP) has been developed to simulate flooded areas besides rivers within cities. FLOODMAP requires a minimum of input data (digital el- evation model (DEM), river line, water level plain) and parameters and calculates the flood extent as well as the spatial distribution of flood depths. of course the simulated model results are affected by errors and uncertainties. Possible sources of uncertain- ties are the model structure, model parameters and input data. Thus after the model validation (comparison of simulated water to observed extent, taken from airborne pictures) the uncertainty of the essential input data set (digital elevation model) was analysed. Monte Carlo simulations were performed to assess the effect of uncertain- ties concerning the statistics of DEM quality and to derive flooding probabilities from the set of simulations. The questions concerning a minimum resolution of a DEM re- quired for flood simulation and concerning the best aggregation procedure of a given DEM was answered by comparing the results obtained using all available standard GIS aggregation procedures. Seven different aggregation procedures were applied to high resolution DEMs (1-2m) in three cities (Bonn, Cologne, Luxembourg). Basing on this analysis the effect of 'uncertain' DEM data was estimated and compared with other sources of uncertainties. Especially socio-economic information and monetary transfer functions required for a damage risk analysis show a high uncertainty. There- fore this study helps to analyse the weak points of the flood risk and damage risk assessment procedure.

Extreme Flood Events Over the Past 300 Years Recorded in the Sediments of a Mountain Lake in the Altay Mountains, Northwestern China

NASA Astrophysics Data System (ADS)

Wu, J.; Zhou, J.; Shen, B.; Zeng, H.

2017-12-01

Global climate change has the potential to accelerate the hydrological cycle, which may further enhance the temporal frequency of regional extreme floods. Climatic models predict that intra-annual rainfall variability will intensify, which will shift current rainfall regimes towards more extreme systems with lower precipitation frequencies, longer dry periods, and larger individual precipitation events worldwide. Understanding the temporal variations of extreme floods that occur in response to climate change is essential to anticipate the trends in flood magnitude and frequency in the context of global warming. However, currently available instrumental data are not long enough for capturing the most extreme events, thus the acquisition of long duration datasets for historical floods that extend beyond available instrumental records is clearly an important step in discerning trends in flood frequency and magnitude with respect to climate change. In this study, a reconstruction of paleofloods over the past 300 years was conducted through an analysis of grain sizes from the sediments of Kanas Lake in the Altay Mountains of northwestern China. Grain parameters and frequency distributions both demonstrate that two abrupt environment changes exist within the lake sedimentary sequence. Based on canonical discriminant analysis (CDA) and C-M pattern analysis, two flood events corresponding to ca. 1760 AD and ca. 1890 AD were identified, both of which occurred during warmer and wetter climate conditions according to tree-ring records. These two flood events are also evidenced by lake sedimentary records in the Altay and Tianshan areas. Furthermore, through a comparison with other records, the flood event in ca. 1760 AD seems to have occurred in both the arid central Asia and the Alps in Europe, and thus may have been associated with changes in the North Atlantic Oscillation (NAO) index.

An Open-Book Modular Watershed Modeling Framework for Rapid Prototyping of GPM- based Flood Forecasting in International River Basins

NASA Astrophysics Data System (ADS)

Katiyar, N.; Hossain, F.

2006-05-01

Floods have always been disastrous for human life. It accounts for about 15 % of the total death related to natural disasters. There are around 263 transboundary river basins listed by UNESCO, wherein at least 30 countries have more than 95% of their territory locked in one or more such transboundary basins. For flood forecasting in the lower riparian nations of these International River Basins (IRBs), real-time rainfall data from upstream nations is naturally the most critical factor governing the forecasting effectiveness. However, many upstream nations fail to provide data to the lower riparian nations due to a lack of in-situ rainfall measurement infrastructure or a lack of a treaty for real-time sharing of rainfall data. A potential solution is therefore to use satellites that inherently measure rainfall across political boundaries. NASA's proposed Global Precipitation Measurement (GPM) mission appears very promising in providing this vital rainfall information under the data- limited scenario that will continue to prevail in most IRBs. However, satellite rainfall is associated with uncertainty and hence, proper characterization of the satellite rainfall error propagation in hydrologic models for flood forecasting is a critical priority that should be resolved in the coming years in anticipation of GPM. In this study, we assess an open book modular watershed modeling approach for estimating the expected error in flood forecasting related to GPM rainfall data. Our motivation stems from the critical challenge in identifying the specific IRBs that would benefit from a pre-programmed satellite-based forecasting system in anticipation of GPM. As the number of flood-prone IRBs is large, conventional data-intensive implementation of existing physically-based distributed hydrologic models on case-by-case IRBs is considered time-consuming for completing such a global assessment. A more parsimonious approach is justified at the expense of a tolerable loss of detail and accuracy. Through assessment of our proposed modular modeling framework, we present our initial understanding in resolving the fundamental question - Can a parsimonious open-book watershed modeling framework be a physically consistent proxy for rapid and global identification of IRBs in greater need of a GPM-based flood forecasting system?

Exploiting Synoptic-Scale Climate Processes to Develop Nonstationary, Probabilistic Flood Hazard Projections

NASA Astrophysics Data System (ADS)

Spence, C. M.; Brown, C.; Doss-Gollin, J.

2016-12-01

Climate model projections are commonly used for water resources management and planning under nonstationarity, but they do not reliably reproduce intense short-term precipitation and are instead more skilled at broader spatial scales. To provide a credible estimate of flood trend that reflects climate uncertainty, we present a framework that exploits the connections between synoptic-scale oceanic and atmospheric patterns and local-scale flood-producing meteorological events to develop long-term flood hazard projections. We demonstrate the method for the Iowa River, where high flow episodes have been found to correlate with tropical moisture exports that are associated with a pressure dipole across the eastern continental United States We characterize the relationship between flooding on the Iowa River and this pressure dipole through a nonstationary Pareto-Poisson peaks-over-threshold probability distribution estimated based on the historic record. We then combine the results of a trend analysis of dipole index in the historic record with the results of a trend analysis of the dipole index as simulated by General Circulation Models (GCMs) under climate change conditions through a Bayesian framework. The resulting nonstationary posterior distribution of dipole index, combined with the dipole-conditioned peaks-over-threshold flood frequency model, connects local flood hazard to changes in large-scale atmospheric pressure and circulation patterns that are related to flooding in a process-driven framework. The Iowa River example demonstrates that the resulting nonstationary, probabilistic flood hazard projection may be used to inform risk-based flood adaptation decisions.

Application of flood-intensity-duration curve, rainfall-intensity-duration curve and time of concentration to analyze the pattern of storms and their corresponding floods for the natural flood events

NASA Astrophysics Data System (ADS)

Kim, Nam Won; Shin, Mun-Ju; Lee, Jeong Eun

2016-04-01

The analysis of storm effects on floods is essential step for designing hydraulic structure and flood plain. There are previous studies for analyzing the relationship between the storm patterns and peak flow, flood volume and durations for various sizes of the catchments, but they are not enough to analyze the natural storm effects on flood responses quantitatively. This study suggests a novel method of quantitative analysis using unique factors extracted from the time series of storms and floods to investigate the relationship between natural storms and their corresponding flood responses. We used a distributed rainfall-runoff model of Grid based Rainfall-runoff Model (GRM) to generate the simulated flow and areal rainfall for 50 catchments in Republic of Korea size from 5.6 km2 to 1584.2 km2, which are including overlapped dependent catchments and non-overlapped independent catchments. The parameters of the GRM model were calibrated to get the good model performances of Nash-Sutcliffe efficiency. Then Flood-Intensity-Duration Curve (FIDC) and Rainfall-Intensity-Duration Curve (RIDC) were generated by Flood-Duration-Frequency and Intensity-Duration-Frequency methods respectively using the time series of hydrographs and hyetographs. Time of concentration developed for the Korea catchments was used as a consistent measure to extract the unique factors from the FIDC and RIDC over the different size of catchments. These unique factors for the storms and floods were analyzed against the different size of catchments to investigate the natural storm effects on floods. This method can be easily used to get the intuition of the natural storm effects with various patterns on flood responses. Acknowledgement This research was supported by a grant (11-TI-C06) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

Flood Frequency Curves - Use of information on the likelihood of extreme floods

NASA Astrophysics Data System (ADS)

Faber, B.

2011-12-01

Investment in the infrastructure that reduces flood risk for flood-prone communities must incorporate information on the magnitude and frequency of flooding in that area. Traditionally, that information has been a probability distribution of annual maximum streamflows developed from the historical gaged record at a stream site. Practice in the United States fits a Log-Pearson type3 distribution to the annual maximum flows of an unimpaired streamflow record, using the method of moments to estimate distribution parameters. The procedure makes the assumptions that annual peak streamflow events are (1) independent, (2) identically distributed, and (3) form a representative sample of the overall probability distribution. Each of these assumptions can be challenged. We rarely have enough data to form a representative sample, and therefore must compute and display the uncertainty in the estimated flood distribution. But, is there a wet/dry cycle that makes precipitation less than independent between successive years? Are the peak flows caused by different types of events from different statistical populations? How does the watershed or climate changing over time (non-stationarity) affect the probability distribution floods? Potential approaches to avoid these assumptions vary from estimating trend and shift and removing them from early data (and so forming a homogeneous data set), to methods that estimate statistical parameters that vary with time. A further issue in estimating a probability distribution of flood magnitude (the flood frequency curve) is whether a purely statistical approach can accurately capture the range and frequency of floods that are of interest. A meteorologically-based analysis produces "probable maximum precipitation" (PMP) and subsequently a "probable maximum flood" (PMF) that attempts to describe an upper bound on flood magnitude in a particular watershed. This analysis can help constrain the upper tail of the probability distribution, well beyond the range of gaged data or even historical or paleo-flood data, which can be very important in risk analyses performed for flood risk management and dam and levee safety studies.

Earth Observations taken by the Expedition 13 crew

NASA Image and Video Library

2006-09-05

ISS013-E-77351 (5 Sept. 2006) --- Floods in the Volga Delta, Russia are featured in this image photographed by an Expedition 13 crewmember on the International Space Station. This close-up view zooms in on a shipping channel in the western part of the delta. The straight channel is periodically dredged, and the dredge spoils are piled along the edge of the channel in mounds. Surrounding wetlands are partially inundated. Flood waters with muddy sediment stream from the distributaries along channel, producing long streamers along the flow direction. This image was taken a few days after heavy rains in early September 2006 flooded parts of Russia to the north, and captures the flood waters emptying into the Caspian Sea. Since 1978, the Caspian Sea level has risen over 2 meters, submerging valuable wetland habitats, flooding coastlines and both agricultural land and industrial infrastructure. Maintaining channels and coastal developments, and preserving marine and land natural habitats, have become a struggle for the nations surrounding the Caspian. Shallow coastlines like the Volga Delta are at particular risk due to the rising sea level.

Floods in the Niger basin - analysis and attribution

NASA Astrophysics Data System (ADS)

Aich, V.; Koné, B.; Hattermann, F. F.; Müller, E. N.

2014-08-01

This study addresses the increasing flood risk in the Niger basin and assesses the damages that arise from flooding. Statistics from three different sources (EM-DAT, Darthmouth Flood Observatory, NatCat Munich RE) on people affected by floods show positive trends for the entire basin beginning in the 1980s. An assessment of four subregions across the Niger basin indicates even exponential trends for the Sahelian and Sudanian regions. These positive trends for flooding damage match up to a time series of annual maximum discharge (AMAX): the strongest trends in AMAX are detected in the Sahelian and Sudanian regions, where the population is also increasing the fastest and vulnerability generally appears to be very high. The joint effect of these three factors can possibly explain the exponential increase in people affected by floods in these subregions. In a second step, the changes in AMAX are attributed to changes in precipitation and land use via a data-based approach within a hypothesis-testing framework. Analysis of rainfall, heavy precipitation and the runoff coefficient shows a coherent picture of a return to wet conditions in the basin, which we identify as the main driver of the increase in AMAX in the Niger basin. The analysis of flashiness (using the Richards-Baker Index) and the focus on the "Sahel Paradox" of the Sahelian region reveal an additional influence of land-use change, but it seems minor compared to the increase in precipitation.

Damage-reducing measures to manage flood risks in a changing climate

NASA Astrophysics Data System (ADS)

Kreibich, Heidi; Bubeck, Philip; Van Vliet, Mathijs; De Moel, Hans

2014-05-01

Damage due to floods has increased during the last few decades, and further increases are expected in several regions due to climate change and a growing vulnerability. To address the projected increase in flood risk, a combination of structural and non-structural flood risk mitigation measures is considered as a promising adaptation strategy. Such a combination takes into account that flood defence systems may fail, and prepare for unexpected crisis situations via land-use planning, building construction, evacuation and disaster response. Non-structural flood risk mitigation measures like shielding with water shutters or sand bags, building fortification or safeguarding of hazardous substances are often voluntary: they demand self-dependent action by the population at risk (Bubeck et al. 2012; 2013). It is believed that these measures are especially effective in areas with frequent flood events and low flood water levels, but some types of measures showed a significant damage-reducing effect also during extreme flood events, such as the Elbe River flood in August 2002 in Germany (Kreibich et al. 2005; 2011). Despite the growing importance of damage-reducing measures, information is still scarce about factors that motivate people to undertake such measures, the state of implementation of various non-structural measures in different countries and their damage reducing effects. Thus, we collected information and undertook an international review about this topic in the framework of the Dutch KfC project "Climate proof flood risk management". The contribution will present an overview about the available information on damage-reducing measures and draw conclusions for practical flood risk management in a changing climate. References: Bubeck, P., Botzen, W. J. W., Suu, L. T. T., Aerts, J. C. J. H. (2012): Do flood risk perceptions provide useful insights for flood risk management? Findings from central Vietnam. Journal of Flood Risk Management, 5, 4, 295-302 Bubeck, P., Botzen, W. J. W., Kreibich, H., Aerts, J. C. J. H. (2013) Detailed insights into the influence of flood-coping appraisals on mitigation behaviour. Global Environmental Change. DOI:10.1016/j.gloenvcha.2013.05.009. Kreibich, H., Thieken, A. H., Petrow, T., Müller, M., Merz, B. (2005): Flood loss reduction of private households due to building precautionary measures - Lessons Learned from the Elbe flood in August 2002. NHESS, 5, 1, 117-126. Kreibich, H., Christenberger, S., Schwarze, R. (2011) Economic motivation of households to undertake private precautionary measures against floods. NHESS, 11, 2, 309-321.

Not Out of Control: Analysis of the Federal Disaster Spending Trend

DTIC Science & Technology

2016-03-01

included heavy rain, excessive rainfall, tropical storms, hurricanes, flooding, coastal flooding, wind, straight line winds, high winds, tornadoes ...straight line winds, tornadoes , high winds, coastal flooding, soil saturation, and mud flow.174 Despite the high number of severe storm declarations over

Estimating monetary damages from flooding in the United States under a changing climate

EPA Science Inventory

A national-scale analysis of potential changes in monetary damages from flooding under climate change. The approach uses empirically based statistical relationships between historical precipitation and flood damage records from 18 hydrologic regions of the United States, along w...

Forest cover, socioeconomics, and reported flood frequency in developing countries

NASA Astrophysics Data System (ADS)

Ferreira, Susana; Ghimire, Ramesh

2012-08-01

In this paper, we analyze the determinants of the number of large floods reported since 1990. Using the same sample of countries as Bradshaw et al. (2007), and, like them, omitting socioeconomic characteristics from the analysis, we found that a reduction in natural forest cover is associated with an increase in the reported count of large floods. This result does not hold in any of three new analyses we perform. First, we expand the sample to include all the developing countries and all countries for which data were available but were omitted in their study. Second, and more importantly, since forest management is just one possible channel through which humans can influence reported flood frequency, we account for other important human-flood interactions. People are typically responsible for deforestation, but they are also responsible for other land use changes (e.g., urbanization), for floodplain and flood emergency management, and for reporting the floods. Thus, in our analysis we account for population, urban population growth, income, and corruption. Third, we exploit the panel nature of the data to control for unobserved country and time heterogeneity. We conclude that not only is the link between forest cover and reported flood frequency at the country level not robust, it also seems to be driven by sample selection and omitted variable bias. The human impact on the reported frequency of large floods at the country level is not through deforestation.

A flood geodatabase and its climatological applications: the case of Catalonia for the last century

NASA Astrophysics Data System (ADS)

Barnolas, M.; Llasat, M. C.

2007-04-01

Floods are the natural hazards that produce the highest number of casualties and material damage in the Western Mediterranean. An improvement in flood risk assessment and study of a possible increase in flooding occurrence are therefore needed. To carry out these tasks it is important to have at our disposal extensive knowledge on historical floods and to find an efficient way to manage this geographical data. In this paper we present a complete flood database spanning the 20th century for the whole of Catalonia (NE Spain), which includes documentary information (affected areas and damage) and instrumental information (meteorological and hydrological records). This geodatabase, named Inungama, has been implemented on a GIS (Geographical Information System) in order to display all the information within a given geographical scenario, as well as to carry out an analysis thereof using queries, overlays and calculus. Following a description of the type and amount of information stored in the database and the structure of the information system, the first applications of Inungama are presented. The geographical distribution of floods shows the localities which are more likely to be flooded, confirming that the most affected municipalities are the most densely populated ones in coastal areas. Regarding the existence of an increase in flooding occurrence, a temporal analysis has been carried out, showing a steady increase over the last 30 years.

A Study on the Assessment of Multi-Factors Affecting Urban Floods Using Satellite Image: A Case Study in Nakdong Basin, S. Korea

NASA Astrophysics Data System (ADS)

Kwak, Youngjoo; Kondoh, Akihiko

2010-05-01

Floods are also related to the changes in social economic conditions and land use. Recently, floods increased due to rapid urbanization and human activity in the lowland. Therefore, integrated management of total basin system is necessary to get the secure society. Typhoon ‘Rusa’ swept through eastern and southern parts of South Korea in the 2002. This pity experience gave us valuable knowledge that could be used to mitigate the future flood hazards. The purpose of this study is to construct the digital maps of the multi-factors related to urban flood concerning geomorphologic characteristics, land cover, and surface wetness. Parameters particularly consider geomorphologic functional unit, geomorphologic parameters derived from DEM (digital elevation model), and land use. The research area is Nakdong River Basin in S. Korea. As a result of preliminary analysis for Pusan area, the vulnerability map and the flood-prone areas can be extracted by applying spatial analysis on GIS (geographic information system).

Hydrologic regime controls soil phosphorus fluxes in restoration and undisturbed wetlands

USGS Publications Warehouse

Aldous, A.; McCormick, P.; Ferguson, C.; Graham, S.; Craft, C.

2005-01-01

Many wetland restoration projects occur on former agricultural soils that have a history of disturbance and fertilization, making them prone to phosphorus (P) release upon flooding. To study the relationship between P release and hydrologic regime, we collected soil cores from three restoration wetlands and three undisturbed wetlands around Upper Klamath Lake in southern Oregon, U.S.A. Soil cores were subjected to one of three hydrologic regimes - flooded, moist, and dry - for 7.5 weeks, and P fluxes were measured upon reflooding. Soils from restoration wetlands released P upon reflooding regardless of the hydrologic regime, with the greatest releases coming from soils that had been flooded or dried. Undisturbed wetland soils released P only after drying. Patterns in P release can be explained by a combination of physical and biological processes, including the release of iron-bound P due to anoxia in the flooded treatment and the mineralization of organic P under aerobic conditions in the dry treatment. Higher rates of soil P release from restoration wetland soils, particularly under flooded conditions, were associated with higher total P concentrations compared with undisturbed wetland soils. We conclude that maintaining moist soil is the means to minimize P release from recently flooded wetland soils. Alternatively, prolonged flooding provides a means of liberating excess labile P from former agricultural soils while minimizing continued organic P mineralization and soil subsidence. ?? 2005 Society for Ecological Restoration International.

Usefulness and limitations of global flood risk models

NASA Astrophysics Data System (ADS)

Ward, Philip; Jongman, Brenden; Salamon, Peter; Simpson, Alanna; Bates, Paul; De Groeve, Tom; Muis, Sanne; Coughlan de Perez, Erin; Rudari, Roberto; Mark, Trigg; Winsemius, Hessel

2016-04-01

Global flood risk models are now a reality. Initially, their development was driven by a demand from users for first-order global assessments to identify risk hotspots. Relentless upward trends in flood damage over the last decade have enhanced interest in such assessments. The adoption of the Sendai Framework for Disaster Risk Reduction and the Warsaw International Mechanism for Loss and Damage Associated with Climate Change Impacts have made these efforts even more essential. As a result, global flood risk models are being used more and more in practice, by an increasingly large number of practitioners and decision-makers. However, they clearly have their limits compared to local models. To address these issues, a team of scientists and practitioners recently came together at the Global Flood Partnership meeting to critically assess the question 'What can('t) we do with global flood risk models?'. The results of this dialogue (Ward et al., 2013) will be presented, opening a discussion on similar broader initiatives at the science-policy interface in other natural hazards. In this contribution, examples are provided of successful applications of global flood risk models in practice (for example together with the World Bank, Red Cross, and UNISDR), and limitations and gaps between user 'wish-lists' and model capabilities are discussed. Finally, a research agenda is presented for addressing these limitations and reducing the gaps. Ward et al., 2015. Nature Climate Change, doi:10.1038/nclimate2742

An evaluation of the potential of Sentinel 1 for improving flash flood predictions via soil moisture-data assimilation

NASA Astrophysics Data System (ADS)

Cenci, Luca; Pulvirenti, Luca; Boni, Giorgio; Chini, Marco; Matgen, Patrick; Gabellani, Simone; Squicciarino, Giuseppe; Pierdicca, Nazzareno

2017-11-01

The assimilation of satellite-derived soil moisture estimates (soil moisture-data assimilation, SM-DA) into hydrological models has the potential to reduce the uncertainty of streamflow simulations. The improved capacity to monitor the closeness to saturation of small catchments, such as those characterizing the Mediterranean region, can be exploited to enhance flash flood predictions. When compared to other microwave sensors that have been exploited for SM-DA in recent years (e.g. the Advanced SCATterometer - ASCAT), characterized by low spatial/high temporal resolution, the Sentinel 1 (S1) mission provides an excellent opportunity to monitor systematically soil moisture (SM) at high spatial resolution and moderate temporal resolution. The aim of this research was thus to evaluate the impact of S1-based SM-DA for enhancing flash flood predictions of a hydrological model (Continuum) that is currently exploited for civil protection applications in Italy. The analysis was carried out in a representative Mediterranean catchment prone to flash floods, located in north-western Italy, during the time period October 2014-February 2015. It provided some important findings: (i) revealing the potential provided by S1-based SM-DA for improving discharge predictions, especially for higher flows; (ii) suggesting a more appropriate pre-processing technique to be applied to S1 data before the assimilation; and (iii) highlighting that even though high spatial resolution does provide an important contribution in a SM-DA system, the temporal resolution has the most crucial role. S1-derived SM maps are still a relatively new product and, to our knowledge, this is the first work published in an international journal dealing with their assimilation within a hydrological model to improve continuous streamflow simulations and flash flood predictions. Even though the reported results were obtained by analysing a relatively short time period, and thus should be supported by further research activities, we believe this research is timely in order to enhance our understanding of the potential contribution of the S1 data within the SM-DA framework for flash flood risk mitigation.

A Qualitative Analysis of the Spontaneous Volunteer Response to the 2013 Sudan Floods: Changing the Paradigm.

PubMed

Albahari, Amin; Schultz, Carl H

2017-06-01

Introduction While the concept of community resilience is gaining traction, the role of spontaneous volunteers during the initial response to disasters remains controversial. In an attempt to resolve some of the debate, investigators examined the activities of a spontaneous volunteer group called Nafeer after the Sudan floods around the city of Khartoum in August of 2013. Hypothesis Can spontaneous volunteers successfully initiate, coordinate, and deliver sustained assistance immediately after a disaster? This retrospective, descriptive case study involved: (1) interviews with Nafeer members that participated in the disaster response to the Khartoum floods; (2) examination of documents generated during the event; and (3) subsequent benchmarking of their efforts with the Sphere Handbook. Members who agreed to participate were requested to provide all documents in their possession relating to Nafeer. The response by Nafeer was then benchmarked to the Sphere Handbook's six core standards, as well as the 11 minimum standards in essential health services. A total of 11 individuals were interviewed (six from leadership and five from active members). Nafeer's activities included: food provision; delivery of basic health care; environmental sanitation campaigns; efforts to raise awareness; and construction and strengthening of flood barricades. Its use of electronic platforms and social media to collect data and coordinate the organization's response was effective. Nafeer adopted a flat-management structure, dividing itself into 14 committees. A Coordination Committee was in charge of liaising between all committees. The Health and Sanitation Committee supervised two health days which included mobile medical and dentistry clinics supported by a mobile laboratory and pharmacy. The Engineering Committee managed to construct and maintain flood barricades. Nafeer used crowd-sourcing to fund its activities, receiving donations locally and internationally using supporters outside Sudan. Nafeer completely fulfilled three of Sphere's core standards and partially fulfilled the other three, but none of the essential health services standards were fulfilled. Even though the Sphere Handbook was chosen as the best available "gold standard" to benchmark Nafeer's efforts, it showed significant limitations in effectively measuring this group. It appears that independent spontaneous volunteer initiatives, like Nafeer, potentially can improve community resilience and play a significant role in the humanitarian response. Such organizations should be the subject of increased research activity. Relevant bodies should consider issuing separate guidelines supporting spontaneous volunteer organizations. Albahari A , Schultz CH . A qualitative analysis of the spontaneous volunteer response to the 2013 Sudan floods: changing the paradigm. Prehosp Disaster Med. 2017;32(3):240-248.

Flood frequencies and durations and their response to El Niño Southern Oscillation: Global analysis

NASA Astrophysics Data System (ADS)

Ward, P. J.; Kummu, M.; Lall, U.

2016-08-01

Floods are one of the most serious forms of natural hazards in terms of the damages they cause. In 2012 alone, flood damages exceeded 19 billion. A large proportion of the damages from several recent major flood disasters, such as those in South India and South Carolina (2015), England and Wales (2014), the Mississippi (2012), Thailand (2011), Queensland (Australia) (2010-2011), and Pakistan (2010), were related to the long duration of those flood events. However, most flood risk studies to date do not account for flood duration. In this paper, we provide the first global modelling exercise to assess the link between interannual climate variability and flood duration and frequency. Specifically, we examine relationships between simulated flood events and El Niño Southern Oscillation (ENSO). Our results show that the duration of flooding appears to be more sensitive to ENSO than is the case for flood frequency. At the globally aggregated scale, we found floods to be significantly longer during both El Niño and La Niña years, compared to neutral years. At the scale of individual river basins, we found strong correlations between ENSO and both flood frequency and duration for a large number of basins, with generally stronger correlations for flood duration than for flood frequency. Future research on flood impacts should attempt to incorporate more information on flood durations.

Thirty Years Later: Reflections of the Big Thompson Flood, Colorado, 1976 to 2006

NASA Astrophysics Data System (ADS)

Jarrett, R. D.; Costa, J. E.; Brunstein, F. C.; Quesenberry, C. A.; Vandas, S. J.; Capesius, J. P.; O'Neill, G. B.

2006-12-01

Thirty years ago, over 300 mm of rain fell in about 4 to 6 hours in the middle reaches of the Big Thompson River Basin during the devastating flash flood on July 31, 1976. The rainstorm produced flood discharges that exceeded 40 m3/s/km2. A peak discharge of 883 m3/s was estimated at the Big Thompson River near Drake streamflow-gaging station. The raging waters left 144 people dead, 250 injured, and over 800 people were evacuated by helicopter. Four-hundred eighteen homes and businesses were destroyed, as well as 438 automobiles, and damage to infrastructure left the canyon reachable only via helicopter. Total damage was estimated in excess of $116 million (2006 dollars). Natural hazards similar to the Big Thompson flood are rare, but the probability of a similar event hitting the Front Range, other parts of Colorado, or other parts of the Nation is real. Although much smaller in scale than the Big Thompson flood, several flash floods have happened during the monsoon in early July 2006 in the Colorado foothills that reemphasized the hazards associated with flash flooding. The U.S. Geological Survey (USGS) conducts flood research to help understand and predict the magnitude and likelihood of large streamflow events such as the Big Thompson flood. A summary of hydrologic conditions of the 1976 flood, what the 1976 flood can teach us about flash floods, a description of some of the advances in USGS flood science as a consequence of this disaster, and lessons that we learned to help reduce loss of life from this extraordinary flash flood are discussed. In the 30 years since the Big Thompson flood, there have been important advances in streamflow monitoring and flood warning. The National Weather Service (NWS) NEXRAD radar allows real-time monitoring of precipitation in most places in the United States. The USGS currently (2006) operates about 7,250 real-time streamflow-gaging stations in the United States that are monitored by the USGS, the NWS, and emergency managers. When substantial flooding occurs, the USGS mobilizes personnel to collect streamflow data in affected areas. Streamflow data improve flood forecasting and provide data for flood-frequency analysis for floodplain management, design of structures located in floodplains, and related water studies. An important lesson learned is that nature provides environmental signs before and during floods that can help people avoid hazard areas. Important contributions to flood science as a result of the 1976 flood include development of paleoflood methods to interpret the preserved flood-plain stratigraphy to document the number, magnitude, and age of floods that occurred prior to streamflow monitoring. These methods and data on large floods can be used in many mountain-river systems to help us better understand flood hazards and plan for the future. For example, according to conventional flood-frequency analysis, the 1976 Big Thompson flood had a flood recurrence interval of about 100 years. However, paleoflood research indicated the 1976 flood was the largest in about the last 10,000 years in the basin and had a flood recurrence interval in excess of 1,000 years.

Methods for estimating the magnitude and frequency of floods for urban and small, rural streams in Georgia, South Carolina, and North Carolina, 2011

USGS Publications Warehouse

Feaster, Toby D.; Gotvald, Anthony J.; Weaver, J. Curtis

2014-01-01

Reliable estimates of the magnitude and frequency of floods are essential for the design of transportation and water-conveyance structures, flood-insurance studies, and flood-plain management. Such estimates are particularly important in densely populated urban areas. In order to increase the number of streamflow-gaging stations (streamgages) available for analysis, expand the geographical coverage that would allow for application of regional regression equations across State boundaries, and build on a previous flood-frequency investigation of rural U.S Geological Survey streamgages in the Southeast United States, a multistate approach was used to update methods for determining the magnitude and frequency of floods in urban and small, rural streams that are not substantially affected by regulation or tidal fluctuations in Georgia, South Carolina, and North Carolina. The at-site flood-frequency analysis of annual peak-flow data for urban and small, rural streams (through September 30, 2011) included 116 urban streamgages and 32 small, rural streamgages, defined in this report as basins draining less than 1 square mile. The regional regression analysis included annual peak-flow data from an additional 338 rural streamgages previously included in U.S. Geological Survey flood-frequency reports and 2 additional rural streamgages in North Carolina that were not included in the previous Southeast rural flood-frequency investigation for a total of 488 streamgages included in the urban and small, rural regression analysis. The at-site flood-frequency analyses for the urban and small, rural streamgages included the expected moments algorithm, which is a modification of the Bulletin 17B log-Pearson type III method for fitting the statistical distribution to the logarithms of the annual peak flows. Where applicable, the flood-frequency analysis also included low-outlier and historic information. Additionally, the application of a generalized Grubbs-Becks test allowed for the detection of multiple potentially influential low outliers. Streamgage basin characteristics were determined using geographical information system techniques. Initial ordinary least squares regression simulations reduced the number of basin characteristics on the basis of such factors as statistical significance, coefficient of determination, Mallow’s Cp statistic, and ease of measurement of the explanatory variable. Application of generalized least squares regression techniques produced final predictive (regression) equations for estimating the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probability flows for urban and small, rural ungaged basins for three hydrologic regions (HR1, Piedmont–Ridge and Valley; HR3, Sand Hills; and HR4, Coastal Plain), which previously had been defined from exploratory regression analysis in the Southeast rural flood-frequency investigation. Because of the limited availability of urban streamgages in the Coastal Plain of Georgia, South Carolina, and North Carolina, additional urban streamgages in Florida and New Jersey were used in the regression analysis for this region. Including the urban streamgages in New Jersey allowed for the expansion of the applicability of the predictive equations in the Coastal Plain from 3.5 to 53.5 square miles. Average standard error of prediction for the predictive equations, which is a measure of the average accuracy of the regression equations when predicting flood estimates for ungaged sites, range from 25.0 percent for the 10-percent annual exceedance probability regression equation for the Piedmont–Ridge and Valley region to 73.3 percent for the 0.2-percent annual exceedance probability regression equation for the Sand Hills region.

Riparian plant community responses to increased flooding: a meta-analysis.

PubMed

Garssen, Annemarie G; Baattrup-Pedersen, Annette; Voesenek, Laurentius A C J; Verhoeven, Jos T A; Soons, Merel B

2015-08-01

A future higher risk of severe flooding of streams and rivers has been projected to change riparian plant community composition and species richness, but the extent and direction of the expected change remain uncertain. We conducted a meta-analysis to synthesize globally available experimental evidence and assess the effects of increased flooding on (1) riparian adult plant and seedling survival, (2) riparian plant biomass and (3) riparian plant species composition and richness. We evaluated which plant traits are of key importance for the response of riparian plant species to flooding. We identified and analysed 53 papers from ISI Web of Knowledge which presented quantitative experimental results on flooding treatments and corresponding control situations. Our meta-analysis demonstrated how longer duration of flooding, greater depth of flooding and, particularly, their combination reduce seedling survival of most riparian species. Plant height above water level, ability to elongate shoots and plasticity in root porosity were decisive for adult plant survival and growth during longer periods of flooding. Both 'quiescence' and 'escape' proved to be successful strategies promoting riparian plant survival, which was reflected in the wide variation in survival (full range between 0 and 100%) under fully submerged conditions, while plants that protrude above the water level (>20 cm) almost all survive. Our survey confirmed that the projected increase in the duration and depth of flooding periods is sufficient to result in species shifts. These shifts may lead to increased or decreased riparian species richness depending on the nutrient, climatic and hydrological status of the catchment. Species richness was generally reduced at flooded sites in nutrient-rich catchments and sites that previously experienced relatively stable hydrographs (e.g. rain-fed lowland streams). Species richness usually increased at sites in desert and semi-arid climate regions (e.g. intermittent streams). © 2015 John The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Climate Change Adaptation Decision Making for Glacial Lake Outburst Floods From Palcacocha Lake in Peru

NASA Astrophysics Data System (ADS)

Cuellar, A. D.; McKinney, D. C.

2014-12-01

Climate change has accelerated glacial retreat in high altitude glaciated regions of Peru leading to the growth and formation of glacier lakes. Glacial lake outburst floods (GLOF) are sudden events triggered by an earthquake, avalanche into the lake or other shock that causes a sudden outflow of water. These floods are catastrophic because of their sudden onset, the difficulty predicting them, and enormous quantity of water and debris rapidly flooding downstream areas. Palcacocha Lake in the Peruvian Andes has experienced accelerated growth since it burst in 1941 and threatens the major city of Huaraz and surrounding communities. Since the 1941 flood stakeholders have advocated for projects to adapt to the increasing threat posed by Palcacocha Lake. Nonetheless, discussions surrounding projects for Palcacocha have not included a rigorous analysis of the potential consequences of a flood, probability of an event, or costs of mitigation projects. This work presents the first step to rationally analyze the risks posed by Palcacocha Lake and the various adaptation projects proposed. In this work the authors use decision analysis to asses proposed adaptation measures that would mitigate damage in downstream communities from a GLOF. We use an existing hydrodynamic model of the at-risk area to determine how adaptation projects will affect downstream flooding. Flood characteristics are used in the HEC-FIA software to estimate fatalities and injuries from an outburst flood, which we convert to monetary units using the value of a statistical life. We combine the monetary consequences of a GLOF with the cost of the proposed projects and a diffuse probability distribution for the likelihood of an event to estimate the expected cost of the adaptation plans. From this analysis we found that lowering the lake level by 15 meters has the least expected cost of any proposal despite uncertainty in the effect of lake lowering on flooding downstream.

A Probabilistic Analysis of Surface Water Flood Risk in London.

PubMed

Jenkins, Katie; Hall, Jim; Glenis, Vassilis; Kilsby, Chris

2018-06-01

Flooding in urban areas during heavy rainfall, often characterized by short duration and high-intensity events, is known as "surface water flooding." Analyzing surface water flood risk is complex as it requires understanding of biophysical and human factors, such as the localized scale and nature of heavy precipitation events, characteristics of the urban area affected (including detailed topography and drainage networks), and the spatial distribution of economic and social vulnerability. Climate change is recognized as having the potential to enhance the intensity and frequency of heavy rainfall events. This study develops a methodology to link high spatial resolution probabilistic projections of hourly precipitation with detailed surface water flood depth maps and characterization of urban vulnerability to estimate surface water flood risk. It incorporates probabilistic information on the range of uncertainties in future precipitation in a changing climate. The method is applied to a case study of Greater London and highlights that both the frequency and spatial extent of surface water flood events are set to increase under future climate change. The expected annual damage from surface water flooding is estimated to be to be £171 million, £343 million, and £390 million/year under the baseline, 2030 high, and 2050 high climate change scenarios, respectively. © 2017 Society for Risk Analysis.

Twitter communication during 2014 flood in Malaysia: Informational or emotional?

NASA Astrophysics Data System (ADS)

Supian, Muhammad Nazirul Aiman Abu; Razak, Fatimah Abdul; Bakar, Sakhinah Abu

2017-04-01

Twitter has become one of the most important medium in spreading information due to its powerful capability reaching beyond the original tweet's follower. Not to mention, it is effective and easy to get viral especially during extreme events. The behaviour of information dissemination during a natural disaster, specifically flood has been an interest to this study. This paper examines the dynamics of social networks and the formation and evolution of Twitter communities in response to this event. A Twitter dataset of early days during 2014 flood in Malaysia were harnessed. The datasets were harnessed based on the keyword "banjir" in Malay which define as flood from 18 December 2014 until 31 December 2014. The analysis shows that the evolution of Twitter conversation during this range of time tends to focus on flood issue. We get to distinguish the informational and emotional tweets from the content analysis. The dynamics of these informational and emotional tweets are then analysed to observe information dissemination in the community. Emotional tweets are likely to be related to community concern and motivational support. Informational tweets are mostly about the flood condition from time to time, numbers of flood victims, and the flood relief from the government organization, aid organization and news organization.

In search of robust flood risk management alternatives for the Netherlands

NASA Astrophysics Data System (ADS)

Klijn, F.; Knoop, J. M.; Ligtvoet, W.; Mens, M. J. P.

2012-05-01

The Netherlands' policy for flood risk management is being revised in view of a sustainable development against a background of climate change, sea level rise and increasing socio-economic vulnerability to floods. This calls for a thorough policy analysis, which can only be adequate when there is agreement about the "framing" of the problem and about the strategic alternatives that should be taken into account. In support of this framing, we performed an exploratory policy analysis, applying future climate and socio-economic scenarios to account for the autonomous development of flood risks, and defined a number of different strategic alternatives for flood risk management at the national level. These alternatives, ranging from flood protection by brute force to reduction of the vulnerability by spatial planning only, were compared with continuation of the current policy on a number of criteria, comprising costs, the reduction of fatality risk and economic risk, and their robustness in relation to uncertainties. We found that a change of policy away from conventional embankments towards gaining control over the flooding process by making the embankments unbreachable is attractive. By thus influencing exposure to flooding, the fatality risk can be effectively reduced at even lower net societal costs than by continuation of the present policy or by raising the protection standards where cost-effective.

Factors affecting flood insurance purchase in residential properties in Johor, Malaysia

NASA Astrophysics Data System (ADS)

Aliagha, U. G.; Jin, T. E.; Choong, W. W.; Nadzri Jaafar, M.; Ali, H. M.

2014-12-01

High-impact floods have become a virtually annual experience in Malaysia, yet flood insurance has remained a grossly neglected part of comprehensive integrated flood risk management. Using discriminant analysis, this study seeks to identify the demand-side variables that best predict flood insurance purchase and risk aversion between two groups of residential homeowners in three districts of Johor State, Malaysia: those who purchased flood insurance and those who did not. Our results revealed an overall 34% purchase rate, with Kota Tinggi district having the highest (44%) and thus the highest degree of flood risk aversion. The Wilks' lambda F test for equality of group means, standardised discriminant function coefficients, structure correlation, and canonical correlation has clearly shown that there are strong significant attribute differences between the two groups of homeowners, based on the measures of objective flood risk exposure, subjective risk perception, and socio-economic cum demographic variables. However, the measures of subjective risk perception were found to be more predictive of flood insurance purchase and flood risk aversion.

Factors affecting flood insurance penetration in residential properties in Johor Malaysia

NASA Astrophysics Data System (ADS)

Godwin Aliagha, U.; Ewe Jin, T.; Weng Choong, W.; Nadzri Jaafar, M.

2014-04-01

High impact flood has virtually become an annual experience in Malaysia, yet flood insurance has remained a grossly neglected part of comprehensive integrated flood risk management. Using discriminant analysis, this study seeks to indentify the demand-side variables that best predict flood insurance penetration and risk aversion between two groups of residential homeowners in three districts of Johor State, Malaysia: those who purchased flood insurance and the group that did not. Our result revealed 34% penetration rate with Kota Tinggi district having the highest penetration (44%) and thus, the highest degree of flood risk aversion. The Wilks' Lambda F test for equality of group means, SCDFC, structure correlation and canonical correlation have clearly shown that there are strong significant attribute differences between the two groups of homeowners based on measures of objective flood risk exposure, subjective risk perception, and socio-economic cum demographic variables. However, measures of subjective risk perception were found more predictive of flood insurance penetration and flood risk aversion.

Analysis of road traffic obstructions caused by the central European flood in June 2013 in Germany

NASA Astrophysics Data System (ADS)

Bessel, Tina

2014-05-01

The flood in June 2013 caused in Germany severe damage to infrastructure and has had a great impact on transportation. Traffic was disrupted in the interregional transportation network including federal highways and long distance railways. Researchers from the Center for Disaster Management and Risk Reduction Technology (CEDIM) aim to develop rapid assessment tools which allow a science based estimation of disaster impacts. This is part of a larger project called Forensic Disaster Analysis (FDA). During the flood event, the CEDIM FDA group on transportation disruptions monitored and recorded traffic reports in Germany to obtain accurate information on road traffic obstructions due to the flood. A rapid initial evaluation of the data was carried out for federal and interstate highways on a district level for the period of May 31 till June 4 2013. In this evaluation, the causes and types of traffic obstruction, as well as the number and duration of flood-caused disruptions are considered. In the evaluated time period of five days, an amount of more than 4,800 hours of flood-related traffic obstructions could be observed in a total of 89 districts. Major traffic disruptions were located in the districts along the Mulde and in the foothills of the Alps. This first initial evaluation will be followed by a detailed statistical analysis including all data collected during the flood event. To assess the impacts of the flood on traffic, a simple traffic simulation considering the disruptions will be carried out using a gravity model.

Flood damage assessment using computer-assisted analysis of color infrared photography

USGS Publications Warehouse

Anderson, William H.

1978-01-01

Use of digitized aerial photographs for flood damage assessment in agriculture is new and largely untested. However, under flooding circumstances similar to the 1975 Red River Valley flood, computer-assisted techniques can be extremely useful, especially if detailed crop damage estimates are needed within a relatively short period of time.Airphoto interpretation techniques, manual or computer-assisted, are not intended to replace conventional ground survey and sampling procedures. But their use should be considered a valuable addition to the tools currently available for assessing agricultural flood damage.

Disaster waste management in Italy: Analysis of recent case studies.

PubMed

Gabrielli, Francesco; Amato, Alessia; Balducci, Susanna; Magi Galluzzi, Lorenzo; Beolchini, Francesca

2018-01-01

The geomorphology of the Italian territory causes the incidence of many disasters like earthquakes and floods, with the consequent production of large volumes of waste. The management of such huge flows, produced in a very short time, may have a high impact on the whole emergency response. Moreover, historical data related to disaster waste management are often not easily accessible; on the other hand, the availability of data concerning previous events could support the emergency managers, that have to take a decision in a very short time. In this context, the present paper analyses four relevant recent case studies in Italy, dealing with disaster waste management after geologic and hydrologic natural events. Significant differences have been observed in the quantity and types of generated wastes, and, also, in the management approach. Such differences are mainly associated with the kind of disaster (i.e. earthquake vs. flood), to the geographical location (i.e. internal vs. coastal area), to the urbanisation level (i.e. industrial vs. urban). The study allowed the identification of both strengths and weaknesses of the applied waste management strategies, that represent "lessons to learn" for future scenarios. Even though it deals with Italian case studies, this manuscript may have a high impact also at international level, making available for the first-time emergency waste management data, that are considered an indispensable support for decision makers. Copyright © 2017 Elsevier Ltd. All rights reserved.

BICAPA case study of natural hazards that trigger technological disasters

NASA Astrophysics Data System (ADS)

Boca, Gabriela; Ozunu, Alexandru; Nicolae Vlad, Serban

2010-05-01

Industrial facilities are vulnerable to natural disasters. Natural disasters and technological accidents are not always singular or isolated events. The example in this paper show that they can occur in complex combinations and/or in rapid succession, known as NaTech disasters, thereby triggering multiple impacts. This analysis indicates that NaTech disasters have the potential to trigger hazmat releases and other types of technological accidents. Climate changes play an important role in prevalence and NATECH triggering mechanisms. Projections under the IPCC IS92 a scenario (similar to SRES A1B; IPCC, 1992) and two GCMs indicate that the risk of floods increases in central and eastern Europe. Increase in intense short-duration precipitation is likely to lead to increased risk of flash floods. (Lehner et al., 2006). It is emergent to develop tools for the assessment of risks due to NATECH events in the industrial processes, in a framework starting with the characterization of frequency and severity of natural disasters and continuing with complex analysis of industrial processes, to risk assessment and residual functionality analysis. The Ponds with dangerous technological residues are the most vulnerable targets of natural hazards. Technological accidents such as those in Baia Mare, (from January to March 2000) had an important international echo. Extreme weather phenomena, like those in the winter of 2000 in Baia Mare, and other natural disasters such as floods or earthquakes, can cause a similar disaster at Târnăveni in Transylvania Depression. During 1972 - 1978 three decanting ponds were built on the Chemical Platform Târnăveni, now SC BICAPA SA, for disposal of the hazardous-wastes resulting from the manufacture of sodium dichromate, inorganic salts, sludge from waste water purification and filtration, wet gas production from carbide. The ponds are located on the right bank of the river Târnava at about 35-50m from the flooding defense dam. The total amount of toxic waste stored in the three ponds is about 2500 tons, equivalent at 128 tons expressed in hexavalent chromium. The ponds contour dikes are strongly damaged in many places, their safety is jeopardized by leakages, sliding slopes and ravens. The upstream dike has an increased failure risk. The upstream dike has an increased failure risk. In that section the coefficients of safety are under the allowable limit, both in static applications, and the earthquake. The risk of failure is very high also due to the dikes slopes. The risk becomes higher in case of heavy rainfall, floods or an earthquake.

Combining Space-Based and In-Situ Measurements to Track Flooding in Thailand

NASA Technical Reports Server (NTRS)

Chien, Steve; Doubleday, Joshua; Mclaren, David; Tran, Daniel; Tanpipat, Veerachai; Chitradon, Royal; Boonya-aaroonnet, Surajate; Thanapakpawin, Porranee; Khunboa, Chatchai; Leelapatra, Watis;

Morphometric Analysis to Prioritize Sub-Watershed for Flood Risk Assessment in Central Karakoram National Park Using Gis/rs Approach

NASA Astrophysics Data System (ADS)

Syed, N. H.; Rehman, A. A.; Hussain, D.; Ishaq, S.; Khan, A. A.

2017-11-01

Morphometric analysis is vital for any watershed investigation and it is inevitable for flood risk assessment in sub-watershed basins. Present study undertaken to carry out critical evaluation and assessment of sub watershed morphological parameters for flood risk assessment of Central Karakorum National Park (CKNP), where Geographical information system and remote sensing (GIS & RS) approach used for quantifying the parameter and mapping of sub watershed units. ASTER DEM used as a geo-spatial data for watershed delineation and stream network. Morphometric analysis carried out using spatial analyst tool of ArcGIS 10.2. The parameters included were bifurcation ratio (Rb), Drainage Texture (Rt), Circulatory ratio (Rc), Elongated ratio (Re), Drainage density (Dd), Stream Length (Lu), Stream order (Su), Slope and Basin length (Lb) have calculated separately. The analysis revealed that the stream order varies from order 1 to 6 and the total numbers of stream segments of all orders were 52. Multi criteria analysis process used to calculate the risk factor. As an accomplished result, map of sub watershed prioritization developed using weighted standardized risk factor. These results helped to understand sensitivity of flush floods in different sub watersheds of the study area and leaded to better management of the mountainous regions in prospect of flush floods.

New Orleans after Hurricane Katrina

NASA Image and Video Library

2005-09-08

JSC2005-E-37987 (8 September 2005) --- The extent of flooding in the greater New Orleans metropolitan area is clearly visible in this image, acquired from the International Space Station on September 8, 2005. Flooded areas are dark greenish brown, while dry areas to the west of the 17th Street Canal and along the banks of the Mississippi River (lower half of image) are light brown to gray. This cropped image (from the parent frame ISS011-E-12527) is oriented with north to the top.

New Orleans after Hurricane Katrina

NASA Image and Video Library

2005-09-08

JSC2005-E-37989 (8 September 2005)--- Extensive flooding of neighborhoods to the east of the 17th Street Canal (left center, oriented north-south) is evident in this image acquired on September 8, 2005 from the International Space Station. Standing water in the street grid imparts a dark greenish brown coloration to the inundated regions. Flooded portions of I-610 (extending east-west) are clearly visible in the center of the image. Image is cropped from original ISS011-E-12527 and is oriented with north to the top.

[Climate change, floods and health intervention].

PubMed

Furu, Peter; Tellier, Siri; Vestergaard, Lasse S

2017-05-15

Climate change and variability are considered some of the biggest threats to human health in the 21st century. Extreme weather events such as floods and storms are examples of natural hazards resulting in highest number of disasters and with considerable mortality and morbidity among vulnerable communities. A coordinated, well-planned management of health interventions must be taken for timely action in the response, recovery, prevention and preparedness phases of disasters. Roles and responsibilities of international as well as national organizations and authorities are discussed.

Remote Sensing of Surficial Process Responses to Extreme Meteorological Events

NASA Technical Reports Server (NTRS)

Brakenridge, G. Robert

1997-01-01

Changes in the frequency and magnitude of extreme meteorological events are associated with changing environmental means. Such events are important in human affairs, and can also be investigated by orbital remote sensing. During the course of this project, we applied ERS-1, ERS-2, Radarsat, and an airborne sensor (AIRSAR-TOPSAR) to measure flood extents, flood water surface profiles, and flood depths. We established a World Wide Web site (the Dartmouth Flood Observatory) for publishing remote sensing-based maps of contemporary floods worldwide; this is also an online "active archive" that presently constitutes the only global compilation of extreme flood events. We prepared an article for EOS concerning SAR imaging of the Mississippi Valley flood; an article for the International Journal of Remote Sensing on measurement of a river flood wave using ERS-2, began work on an article (since completed and published) on the Flood Observatory for a Geoscience Information Society Proceedings volume, and presented lectures at several Geol. Soc. of America Natl. Meetings, an Assoc. of Amer. Geographers Natl. Meeting, and a Binghamton Geomorphology Symposium (all on SAR remote sensing of the Mississippi Valley flood). We expanded in-house modeling capabilities by installing the latest version of the Army Corps of Engineers RMA two-dimensional hydraulics software and BYU Engineering Graphics Lab's Surface Water Modeling System (finite elements based pre- and post-processors for RMA work) and also added watershed modeling software. We are presently comparing the results of the 2-d flow models with SAR image data. The grant also supported several important upgrades of pc-based remote sensing infrastructure at Dartmouth. During work on this grant, we collaborated with several workers at the U.S. Army Corps of Engineers, Remote Sensing/GIS laboratory (for flood inundation mapping and modeling; particularly of the Illinois River using the AIRSAR/TOPSAR/ERS-2 combined data), with Dr. Karen Prestegaard at the University of Maryland (geomorphological responses to the extreme 1993 flood along the Raccoon drainage in central Iowa), and with Mr Tim Scrom of the Albany National Weather Service River Forecast Center (initial planning for the use of Radarsat and ERS-2 for flood warning). The work thus initiated with this proposal is continuing.

A framework for global river flood risk assessment

NASA Astrophysics Data System (ADS)

Winsemius, H. C.; Van Beek, L. P. H.; Bouwman, A.; Ward, P. J.; Jongman, B.

2012-04-01

There is an increasing need for strategic global assessments of flood risks. Such assessments may be required by: (a) International Financing Institutes and Disaster Management Agencies to evaluate where, when, and which investments in flood risk mitigation are most required; (b) (re-)insurers, who need to determine their required coverage capital; and (c) large companies to account for risks of regional investments. In this contribution, we propose a framework for global river flood risk assessment. The framework combines coarse scale resolution hazard probability distributions, derived from global hydrological model runs (typical scale about 0.5 degree resolution) with high resolution estimates of exposure indicators. The high resolution is required because floods typically occur at a much smaller scale than the typical resolution of global hydrological models, and exposure indicators such as population, land use and economic value generally are strongly variable in space and time. The framework therefore estimates hazard at a high resolution ( 1 km2) by using a) global forcing data sets of the current (or in scenario mode, future) climate; b) a global hydrological model; c) a global flood routing model, and d) importantly, a flood spatial downscaling routine. This results in probability distributions of annual flood extremes as an indicator of flood hazard, at the appropriate resolution. A second component of the framework combines the hazard probability distribution with classical flood impact models (e.g. damage, affected GDP, affected population) to establish indicators for flood risk. The framework can be applied with a large number of datasets and models and sensitivities of such choices can be evaluated by the user. The framework is applied using the global hydrological model PCR-GLOBWB, combined with a global flood routing model. Downscaling of the hazard probability distributions to 1 km2 resolution is performed with a new downscaling algorithm, applied on a number of target regions. We demonstrate the use of impact models in these regions based on global GDP, population, and land use maps. In this application, we show sensitivities of the estimated risks with regard to the use of different climate input datasets, decisions made in the downscaling algorithm, and different approaches to establish distributed estimates of GDP and asset exposure to flooding.

Effects of large floods on channel width: recent insights from Italian rivers

NASA Astrophysics Data System (ADS)

Scorpio, Vittoria; Righini, Margherita; Amponsah, William; Crema, Stefano; Ciccarese, Giuseppe; Nardi, Laura; Zoccatelli, Davide; Borga, Marco; Cavalli, Marco; Comiti, Francesco; Corsini, Alessandro; Marchi, Lorenzo; Rinaldi, Massimo; Surian, Nicola

2017-04-01

Variations of channel morphology occurring during large flood events (recurrence interval > 50-100 years.) are very often the cause of damages to buildings and infrastructures, as well as of casualties. However, our knowledge of such processes remains poor, as is our capability to predict them. Post-event campaigns documenting channel changes and linking them to hydrological and morphological factors thus bear an enormous value for both the scientific community and river management agencies. We present the results of an analysis on the geomorphic response associated to 4 large floods that occurred between October 2011 and September 2015, affecting several catchments in Northern Italy (Magra-Vara, Trebbia, Nure rivers) and Sardinia (Posada and Mannu di Bitti rivers), characterized by different climatic, lithological and geomorphological settings. The analysis considered more than 400 channel reaches characterized by a drainage area ranging from 39 to 1,100 km2 and featuring a wide range of lateral confinement, mostly within the partly- and unconfined conditions. The approach to flood analysis encompassed: (i) hydrological and hydraulic analysis; (ii) analysis of sediment delivery by landslides to the channel network; (iii) GIS-based and field assessment of morphological channel modifications. For the Nure River flood event (September 2015) a quantitative assessment on average bed level variations was also carried out. Return period for maximum hourly rainfall intensities and peak water discharges exceeded in all basins 100 yr, in some cases even 300 yr. Very high unit peak discharges were estimated, reaching 8.8 m3 s-1km-2 in the Nure River (205 km2) and up to 30 m3 s-1km-2in few Magra River tributaries (5-10 km2). Notable channel widening (post-flood width / pre-flood width > 1.1) occurred in 83% of studied reaches, and it was found more relevant in the channels with narrower initial width, i.e. along the relatively steep tributaries. For these tributaries, the ratio between post-flood and pre-flood width presents an average value of 4.2, with a maximum approaching 20. In the main river channels, due to the presence of wider sections and lower slope, the ratio resulted < 5, on average 1.3. The analysis of width ratio vs. flood peak unit stream power shows that the minimum unit stream power required to cause relevant widening was about 500 Wm-2. Nonetheless, some reaches affected by unit stream power as high as 4,000 Wm-2 exhibited limited or no widening at all. Indeed, a statistical analysis on the relationship between widening and both morphological and hydraulic controlling factors indicates that unit stream power and confinement index were the most relevant variables, whereas sediment input from mass wasting processes seems to have a localized influence. Remarkably, the analysis of subset referring to Trebbia and Nure basins showed that channel widening is strongly associated to bed aggradation, and that steeper tributaries underwent higher aggradation despite their larger sediment transport capacity. These results points out that geomorphic changes due to large floods are controlled by several factors that induce a highly variable pattern of change even within the same river basin.

Quantitative analysis of burden of bacillary dysentery associated with floods in Hunan, China.

PubMed

Liu, Xuena; Liu, Zhidong; Zhang, Ying; Jiang, Baofa

2016-03-15

Jishou and Huaihua, two cities in the west of Hunan Province, had suffered from severe floods because of long-lasting and heavy rainfall during the end of June and July 2012. However, the Disability Adjusted of Life Years (DALYs) of bacillary dysentery caused by the floods have not been examined before. The study aimed to quantify the impact of the floods on the burden of bacillary dysentery in Hunan, China. A unidirectional case-crossover study was firstly conducted to determine the relationship between daily cases of bacillary dysentery and the floods in Jishou and Huaihua of Hunan Province in 2012. Odds ratios (ORs) estimated by conditional logistic regression were used to quantify the risk of the floods on the disease. The years lived with disability (YLDs) of bacillary dysentery attributable to floods were then estimated based on the WHO framework to calculate potential impact fraction in the Burden of Disease study. Multivariable analysis showed that floods were significantly associated with an increased risk of the number of cases of bacillary dysentery (OR=3.270, 95% CI: 1.299-8.228 in Jishou; OR=2.212, 95% CI: 1.052-4.650 in Huaihua). The strongest effect was shown with a 1-day lag in Jishou and a 4-day lag in Huaihua. Attributable YLD per 1000 of bacillary dysentery due to the floods was 0.0296 in Jishou and 0.0157 in Huaihua. Our study confirms that floods have significantly increased the risks of bacillary dysentery in the study areas. In addition, a sudden and severe flooding with a shorter duration may cause more burdens of bacillary dysentery than a persistent and moderate flooding. Public health preparation and intervention programs should be taken to reduce and prevent a potential risk of bacillary dysentery epidemics after floods. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling Compound Flood Hazards in Coastal Embayments

NASA Astrophysics Data System (ADS)

Moftakhari, H.; Schubert, J. E.; AghaKouchak, A.; Luke, A.; Matthew, R.; Sanders, B. F.

2017-12-01

Coastal cities around the world are built on lowland topography adjacent to coastal embayments and river estuaries, where multiple factors threaten increasing flood hazards (e.g. sea level rise and river flooding). Quantitative risk assessment is required for administration of flood insurance programs and the design of cost-effective flood risk reduction measures. This demands a characterization of extreme water levels such as 100 and 500 year return period events. Furthermore, hydrodynamic flood models are routinely used to characterize localized flood level intensities (i.e., local depth and velocity) based on boundary forcing sampled from extreme value distributions. For example, extreme flood discharges in the U.S. are estimated from measured flood peaks using the Log-Pearson Type III distribution. However, configuring hydrodynamic models for coastal embayments is challenging because of compound extreme flood events: events caused by a combination of extreme sea levels, extreme river discharges, and possibly other factors such as extreme waves and precipitation causing pluvial flooding in urban developments. Here, we present an approach for flood risk assessment that coordinates multivariate extreme analysis with hydrodynamic modeling of coastal embayments. First, we evaluate the significance of correlation structure between terrestrial freshwater inflow and oceanic variables; second, this correlation structure is described using copula functions in unit joint probability domain; and third, we choose a series of compound design scenarios for hydrodynamic modeling based on their occurrence likelihood. The design scenarios include the most likely compound event (with the highest joint probability density), preferred marginal scenario and reproduced time series of ensembles based on Monte Carlo sampling of bivariate hazard domain. The comparison between resulting extreme water dynamics under the compound hazard scenarios explained above provides an insight to the strengths/weaknesses of each approach and helps modelers choose the appropriate scenario that best fit to the needs of their project. The proposed risk assessment approach can help flood hazard modeling practitioners achieve a more reliable estimate of risk, by cautiously reducing the dimensionality of the hazard analysis.

Repetitive flood victims and acceptance of FEMA mitigation offers: an analysis with community-system policy implications.

PubMed

Kick, Edward L; Fraser, James C; Fulkerson, Gregory M; McKinney, Laura A; De Vries, Daniel H

2011-07-01

Of all natural disasters, flooding causes the greatest amount of economic and social damage. The United States' Federal Emergency Management Agency (FEMA) uses a number of hazard mitigation grant programmes for flood victims, including mitigation offers to relocate permanently repetitive flood loss victims. This study examines factors that help to explain the degree of difficulty repetitive flood loss victims experience when they make decisions about relocating permanently after multiple flood losses. Data are drawn from interviews with FEMA officials and a survey of flood victims from eight repetitive flooding sites. The qualitative and quantitative results show the importance of rational choices by flood victims in their mitigation decisions, as they relate to financial variables, perceptions of future risk, attachments to home and community, and the relationships between repetitive flood loss victims and the local flood management officials who help them. The results offer evidence to suggest the value of a more community-system approach to FEMA relocation practices. © 2011 The Author(s). Disasters © Overseas Development Institute, 2011.

Synoptic-scale atmospheric conditions associated with flash flooding in watersheds of the Catskill Mountains, New York, USA

NASA Astrophysics Data System (ADS)

Teale, N. G.; Quiring, S. M.

2015-12-01

Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.

Proteomic analysis of the flooding tolerance mechanism in mutant soybean.

PubMed

Komatsu, Setsuko; Nanjo, Yohei; Nishimura, Minoru

2013-02-21

Flooding stress of soybean is a serious problem because it reduces growth; however, flooding-tolerant cultivars have not been identified. To analyze the flooding tolerance mechanism of soybean, the flooding-tolerant mutant was isolated and analyzed using a proteomic technique. Flooding-tolerance tests were repeated five times using gamma-ray irradiated soybeans, whose root growth (M6 stage) was not suppressed even under flooding stress. Two-day-old wild-type and mutant plants were subjected to flooding stress for 2days, and proteins were identified using a gel-based proteomic technique. In wild-type under flooding stress, levels of proteins related to development, protein synthesis/degradation, secondary metabolism, and the cell wall changed; however, these proteins did not markedly differ in the mutant. In contrast, an increased number of fermentation-related proteins were identified in the mutant under flooding stress. The root tips of mutant plants were not affected by flooding stress, even though the wild-type plants had damaged root. Alcohol dehydrogenase activity in the mutant increased at an early stage of flooding stress compared with that of the wild-type. Taken together, these results suggest that activation of the fermentation system in the early stages of flooding may be an important factor for the acquisition of flooding tolerance in soybean. Copyright © 2012 Elsevier B.V. All rights reserved.

Re-inventing prevention? - An evaluation of tools for strengthening private preparedness for floods and heavy rains

NASA Astrophysics Data System (ADS)

Rohland, Stefanie; Pfurtscheller, Clemens; Seebauer, Sebastian

2016-04-01

Keywords: private preparedness, property protection, flood, heavy rains, Transtheoretical Model, evaluation of methods and tools Experiences in Europe and Austria from coping with numerous floods and heavy rain events in recent decades point to room for improvement in reducing damages and adverse effects. One of the emerging issues is private preparedness, which has only received punctual attention in Austria until now. Current activities to promote property protection are, however, not underpinned by a long-term strategy, thus minimizing their cumulative effect. While printed brochures and online information are widely available, innovative information services, tailored to and actively addressing specific target groups, are thin on the ground. This project reviews (national as well as international) established approaches, with a focus on German-speaking areas, checking their long-term effectiveness with the help of expert workshops and an empirical analysis of survey data. The Transtheoretical Model (Prochaska, 1977) serves as the analytical framework: We assign specific tools to distinct stages of behavioural change. People's openness to absorb risk information or their willingness to engage in private preparedness depend on an incremental process of considering, appraising, introducing and finally maintaining preventive actions. Based on this stage-specific perspective and the workshop results, gaps of intervention are identified to define best-practice examples and recommendations that can be realized within the prevailing legislative and organizational framework at national, regional and local level in Austria.

Report on the costs of domestic and international emergencies and on the threats posed by the Kuwaiti oil fires as required by P. L. 102-55

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-06-01

The report fulfills the requirements of Public Law 12-55, the FY 1992 dire emergency supplemental appropriations bill, signed by the President on June 13, 1991. This law required the Director of the Office of Management and Budget to prepare and submit to the appropriate committees of Congress a report on: unfunded costs of dire emergencies because of floods, droughts, tornadoes, unemployment, and other disasters in the United States; unfunded costs, including food assistance, of international disaster emergencies existing because of floods, droughts, tornadoes, and other disasters; and the threats to oil supply, human health, and the environment that the Kuwaitimore » oil fires might pose.« less

Uncertainty and sensitivity assessment of flood risk assessments

NASA Astrophysics Data System (ADS)

de Moel, H.; Aerts, J. C.

2009-12-01

Floods are one of the most frequent and costly natural disasters. In order to protect human lifes and valuable assets from the effect of floods many defensive structures have been build. Despite these efforts economic losses due to catastrophic flood events have, however, risen substantially during the past couple of decades because of continuing economic developments in flood prone areas. On top of that, climate change is expected to affect the magnitude and frequency of flood events. Because these ongoing trends are expected to continue, a transition can be observed in various countries to move from a protective flood management approach to a more risk based flood management approach. In a risk based approach, flood risk assessments play an important role in supporting decision making. Most flood risk assessments assess flood risks in monetary terms (damage estimated for specific situations or expected annual damage) in order to feed cost-benefit analysis of management measures. Such flood risk assessments contain, however, considerable uncertainties. This is the result from uncertainties in the many different input parameters propagating through the risk assessment and accumulating in the final estimate. Whilst common in some other disciplines, as with integrated assessment models, full uncertainty and sensitivity analyses of flood risk assessments are not so common. Various studies have addressed uncertainties regarding flood risk assessments, but have mainly focussed on the hydrological conditions. However, uncertainties in other components of the risk assessment, like the relation between water depth and monetary damage, can be substantial as well. This research therefore tries to assess the uncertainties of all components of monetary flood risk assessments, using a Monte Carlo based approach. Furthermore, the total uncertainty will also be attributed to the different input parameters using a variance based sensitivity analysis. Assessing and visualizing the uncertainties of the final risk estimate will be helpful to decision makers to make better informed decisions and attributing this uncertainty to the input parameters helps to identify which parameters are most important when it comes to uncertainty in the final estimate and should therefore deserve additional attention in further research.

Efficiency of preventive actions for landslides and flooding - evaluation of Scandinavian practices

NASA Astrophysics Data System (ADS)

Bergman, R.; Andersson-sköld, Y. B.; Nyberg, L.; Johansson, M.; Persson, E.

2011-12-01

Author: Ramona Bergman, Yvonne Andersson-Sköld, Lars Nyberg, Magnus Johansson, Erik Persson Preventive actions can be, and are frequently, taken to reduce accidents and their consequences in different ways. The MSB funded research programme "Effects of Society's Security actions" (ESS, 2009-2013) aims to study the relationship between such actions and their effects. The program is divided into three subgroups: Frequent accidents Natural hazards (such as flooding, erosion and landslide) Chemical and landfill accidents The results presented here covers natural hazards with focus on land slides and flooding. The results are based on Swedish/Scandinavian contexts. Natural events such as erosion, flooding and land slides are common, but the number of accidents (events causing severe negative impact) is rare. Therefore, in such analysis there is limited data and other information available which can be used for example in statistical analysis of actions and their effects. Instead, the analysis must be based on other information. Therefore, the analysis may have to include aspects that only can be assessed by scenario and "what-if" analyses. In this project the main method has been interviews with officials in Swedish municipalities and national agencies in Sweden and Norway. The two levels are chosen since policies are taken on national (or international) level, while the key actions and actors are on the municipal level. The interviews cover experiences and potential scenarios. In all municipalities, one politician and officials working with planning and rescue service have been interviewed. The study covers hazard and risk mapping, follow up of such maps, physical planning and lessons learned from previous events and activities. The final outcome of the research will be a review of what is found to be well functioning, identification of weak points and recommendations for the management of landslides, erosion and flooding. The present results indicate that hazard/risk maps are of great importance, but the knowledge about the maps and how to use them varies depending on who you ask and between municipalities. Most officials in municipalities are aware of climate change (CC) but, due to high uncertainties and since climate induced events such as natural hazards are rare, the issues are often not prioritized. Further, the results indicate that the documentation, communication and the responsibilities among different units is not always clear, having impacts on for example the knowledge transfer to new personnel. Also databases can be useful tools. The project has found that the use of such tools varies between Norway and Sweden. The aim is to identify the reasons for such deviation. The mostly mentioned suggestions of improvement in the prevention process are increased knowledge, user friendly guidance, clear organisational structure and responsibilities and nationally provided ear marked funding for preventive measures.

Vulnerability Assessment Using LIDAR Data in Silang-Sta Rosa Subwatershed, Philippines

NASA Astrophysics Data System (ADS)

Bragais, M. A.; Magcale-Macandog, D. B.; Arizapa, J. L.; Manalo, K. M.

2016-10-01

Silang-Sta. Rosa Subwatershed is experiencing rapid urbanization. Its downstream area is already urbanized and the development is moving fast upstream. With the rapid land conversion of pervious to impervious areas and increase frequency of intense rainfall events, the downstream of the watershed is at risk of flood hazard. The widely used freeware HEC-RAS (Hydrologic Engineering Center- River Analysis System) model was used to implement the 2D unsteady flow analysis to develop a flood hazard map. The LiDAR derived digital elevation model (DEM) with 1m resolution provided detailed terrain that is vital for producing reliable flood extent map that can be used for early warning system. With the detailed information from the simulation like areas to be flooded, the predicted depth and duration, we can now provide specific flood forecasting and mitigation plan even at community level. The methodology of using 2D unsteady flow modelling and high resolution DEM in a watershed can be replicated to other neighbouring watersheds specially those areas that are not yet urbanized so that their development will be guided to be flood hazard resilient. LGUs all over the country will benefit from having a high resolution flood hazard map.

Regional L-Moment-Based Flood Frequency Analysis in the Upper Vistula River Basin, Poland

NASA Astrophysics Data System (ADS)

Rutkowska, A.; Żelazny, M.; Kohnová, S.; Łyp, M.; Banasik, K.

2017-02-01

The Upper Vistula River basin was divided into pooling groups with similar dimensionless frequency distributions of annual maximum river discharge. The cluster analysis and the Hosking and Wallis (HW) L-moment-based method were used to divide the set of 52 mid-sized catchments into disjoint clusters with similar morphometric, land use, and rainfall variables, and to test the homogeneity within clusters. Finally, three and four pooling groups were obtained alternatively. Two methods for identification of the regional distribution function were used, the HW method and the method of Kjeldsen and Prosdocimi based on a bivariate extension of the HW measure. Subsequently, the flood quantile estimates were calculated using the index flood method. The ordinary least squares (OLS) and the generalised least squares (GLS) regression techniques were used to relate the index flood to catchment characteristics. Predictive performance of the regression scheme for the southern part of the Upper Vistula River basin was improved by using GLS instead of OLS. The results of the study can be recommended for the estimation of flood quantiles at ungauged sites, in flood risk mapping applications, and in engineering hydrology to help design flood protection structures.

Quantification of Uncertainty in the Flood Frequency Analysis

NASA Astrophysics Data System (ADS)

Kasiapillai Sudalaimuthu, K.; He, J.; Swami, D.

2017-12-01

Flood frequency analysis (FFA) is usually carried out for planning and designing of water resources and hydraulic structures. Owing to the existence of variability in sample representation, selection of distribution and estimation of distribution parameters, the estimation of flood quantile has been always uncertain. Hence, suitable approaches must be developed to quantify the uncertainty in the form of prediction interval as an alternate to deterministic approach. The developed framework in the present study to include uncertainty in the FFA discusses a multi-objective optimization approach to construct the prediction interval using ensemble of flood quantile. Through this approach, an optimal variability of distribution parameters is identified to carry out FFA. To demonstrate the proposed approach, annual maximum flow data from two gauge stations (Bow river at Calgary and Banff, Canada) are used. The major focus of the present study was to evaluate the changes in magnitude of flood quantiles due to the recent extreme flood event occurred during the year 2013. In addition, the efficacy of the proposed method was further verified using standard bootstrap based sampling approaches and found that the proposed method is reliable in modeling extreme floods as compared to the bootstrap methods.

Studying the hydro-meteorological extremes. The benefits from the European Flash Flood research oriented HYDRATE project.

NASA Astrophysics Data System (ADS)

Tsanis, Ioannis K.; Koutroulis, Aristeidis G.; Daliakopoulos, Ioannis N.; Grillakis, Emmanouil G.

2010-05-01

The present paper summarizes the advances of flash flood research for the Greek case study, within the frame of HYDRATE EC funded project. As a first step, a collation of homogenous primary data on flash floods occurred in Greece based on various data sources resulted in 21 documented events, enriching the HYDRATE database. Specific major events were selected for further detailed data collation and analysis. A common intensive post event field survey was conducted by various researchers with different skills and experience, in order to document the 18th of September 2007, Western Slovenia flash flood event. The observation strategy and the lessons learned during this campaign were applied successfully for surveying an event in Crete. Two flash flood events occurred in Crete were selected for detailed analysis, the 13th of January 1994 event occurred in Giofiros basin and the 17th of October 2006 event occurred in Almirida basin. Several techniques, like distributed rainfall-runoff modelling, hydraulic modelling, indirect and empirical peak discharge estimation, were applied for the understanding of the dominant flash flood processes and the effect of initial conditions on peak discharge. In a more general framework, the seasonality of the hydrometeorologic characteristics of floods that occurred in Crete during the period 1990-2007 and the atmospheric circulation conditions during the flood events were examined. During the three and a half years research period, many lessons have learnt from a fruitful collaboration among the project partners. HYDRATE project improved the scientific basis of flash flood research and provided research knowledge on flood risk management.

A uniform technique for flood frequency analysis.

USGS Publications Warehouse

Thomas, W.O.

1985-01-01

This uniform technique consisted of fitting the logarithms of annual peak discharges to a Pearson Type III distribution using the method of moments. The objective was to adopt a consistent approach for the estimation of floodflow frequencies that could be used in computing average annual flood losses for project evaluation. In addition, a consistent approach was needed for defining equitable flood-hazard zones as part of the National Flood Insurance Program. -from ASCE Publications Information

A formal framework of scenario creation and analysis of extreme hydrological events

NASA Astrophysics Data System (ADS)

Lohmann, D.

2007-12-01

We are presenting a formal framework for a hydrological risk analysis. Different measures of risk will be introduced, such as average annual loss or occurrence exceedance probability. These are important measures for e.g. insurance companies to determine the cost of insurance. One key aspect of investigating the potential consequences of extreme hydrological events (floods and draughts) is the creation of meteorological scenarios that reflect realistic spatial and temporal patterns of precipitation that also have correct local statistics. 100,000 years of these meteorological scenarios are used in a calibrated rainfall-runoff-flood-loss-risk model to produce flood and draught events that have never been observed. The results of this hazard model are statistically analyzed and linked to socio-economic data and vulnerability functions to show the impact of severe flood events. We are showing results from the Risk Management Solutions (RMS) Europe Flood Model to introduce this formal framework.

Global-scale river flood vulnerability in the last 50 years.

PubMed

Tanoue, Masahiro; Hirabayashi, Yukiko; Ikeuchi, Hiroaki

2016-10-26

The impacts of flooding are expected to rise due to population increases, economic growth and climate change. Hence, understanding the physical and spatiotemporal characteristics of risk drivers (hazard, exposure and vulnerability) is required to develop effective flood mitigation measures. Here, the long-term trend in flood vulnerability was analysed globally, calculated from the ratio of the reported flood loss or damage to the modelled flood exposure using a global river and inundation model. A previous study showed decreasing global flood vulnerability over a shorter period using different disaster data. The long-term analysis demonstrated for the first time that flood vulnerability to economic losses in upper-middle, lower-middle and low-income countries shows an inverted U-shape, as a result of the balance between economic growth and various historical socioeconomic efforts to reduce damage, leading to non-significant upward or downward trends. We also show that the flood-exposed population is affected by historical changes in population distribution, with changes in flood vulnerability of up to 48.9%. Both increasing and decreasing trends in flood vulnerability were observed in different countries, implying that population growth scenarios considering spatial distribution changes could affect flood risk projections.

Global-scale river flood vulnerability in the last 50 years

PubMed Central

Tanoue, Masahiro; Hirabayashi, Yukiko; Ikeuchi, Hiroaki

2016-01-01

The impacts of flooding are expected to rise due to population increases, economic growth and climate change. Hence, understanding the physical and spatiotemporal characteristics of risk drivers (hazard, exposure and vulnerability) is required to develop effective flood mitigation measures. Here, the long-term trend in flood vulnerability was analysed globally, calculated from the ratio of the reported flood loss or damage to the modelled flood exposure using a global river and inundation model. A previous study showed decreasing global flood vulnerability over a shorter period using different disaster data. The long-term analysis demonstrated for the first time that flood vulnerability to economic losses in upper-middle, lower-middle and low-income countries shows an inverted U-shape, as a result of the balance between economic growth and various historical socioeconomic efforts to reduce damage, leading to non-significant upward or downward trends. We also show that the flood-exposed population is affected by historical changes in population distribution, with changes in flood vulnerability of up to 48.9%. Both increasing and decreasing trends in flood vulnerability were observed in different countries, implying that population growth scenarios considering spatial distribution changes could affect flood risk projections. PMID:27782160

Evaluation of Flooding Risk and Engineering Protection Against Floods for Ulan-Ude

NASA Astrophysics Data System (ADS)

Borisova, T. A.

2017-11-01

The report presents the results of the study on analysis and risk assessment in relation to floods for Ulan-Ude and provides the developed recommendations of the activities for engineering protection of the population and economic installations. The current situation is reviewed and the results of the site survey are shown to identify the challenges and areas of negative water influence along with the existing security system. The report presents a summary of floods and index risk assessment. The articles describes the scope of eventual flooding, underflooding and enumerates the economic installations inside the urban areas’ research-based zones of flooding at the rated levels of water to identify the likeliness of exceedance. The assessment of damage from flood equal to 1% is shown.

A software tool for rapid flood inundation mapping

USGS Publications Warehouse

Verdin, James; Verdin, Kristine; Mathis, Melissa L.; Magadzire, Tamuka; Kabuchanga, Eric; Woodbury, Mark; Gadain, Hussein

2016-06-02

The GIS Flood Tool (GFT) was developed by the U.S. Geological Survey with support from the U.S. Agency for International Development’s Office of U.S. Foreign Disaster Assistance to provide a means for production of reconnaissance-level flood inundation mapping for data-sparse and resource-limited areas of the world. The GFT has also attracted interest as a tool for rapid assessment flood inundation mapping for the Flood Inundation Mapping Program of the U.S. Geological Survey. The GFT can fill an important gap for communities that lack flood inundation mapping by providing a first-estimate of inundation zones, pending availability of resources to complete an engineering study. The tool can also help identify priority areas for application of scarce flood inundation mapping resources. The technical basis of the GFT is an application of the Manning equation for steady flow in an open channel, operating on specially processed digital elevation data. The GFT is implemented as a software extension in ArcGIS. Output maps from the GFT were validated at 11 sites with inundation maps produced previously by the Flood Inundation Mapping Program using standard one-dimensional hydraulic modeling techniques. In 80 percent of the cases, the GFT inundation patterns matched 75 percent or more of the one-dimensional hydraulic model inundation patterns. Lower rates of pattern agreement were seen at sites with low relief and subtle surface water divides. Although the GFT is simple to use, it should be applied with the oversight or review of a qualified hydraulic engineer who understands the simplifying assumptions of the approach.

History as a guide to the future for cities: coastal storms and Jamaica Bay in New York City as an example.

NASA Astrophysics Data System (ADS)

Sanderson, E. W.; Orton, P. M.; Giampieri, M.; Spagnoli, C.

2015-12-01

History can provide a guide to the future by revealing the physical climatic and geomorphological dynamics with which cities must contend. We used historical maps from the U.S. Coast Survey and the Stevens Estuarine and Coastal Ocean Model (sECOM) to simulate how and where coastal flooding from storm surge affected the Jamaica Bay region of southeastern New York City at different points in time. This area, which houses approximately 1.2 million people today and the John F. Kennedy International Airport, was heavily impacted by coastal flooding during Hurricane Sandy. Historical analysis showed that the Rockaway Peninsula was an active barrier island system up until the early twentieth century, growing approximately 70 meters per year to the west between 1844 - 1891. Older historical maps made by American and European cartographers from 1524 - 1844 suggest that Jamaica Bay may have been a much more open system, with few or no interior marsh islands, at the time of European discovery. From these studies, we constructed digital terrain models and land cover maps for two historical periods: ca. 1870s and ca. 1609, and today. Storm simulations of hurricanes over the historical and present-day landscapes showed how a smaller inlet, shallower channel depths, and larger floodplains all can reduce the height of flooding inside the bay, and suggested a series of leverage experiments that test the efficacy of present-day green infrastructure interventions to lessen peak flood heights while maintaining tidal flushing. By combining history, modelling, and policy-relevant scenarios, we believe we have developed a reshreshing and accessible toolkit for policymakers thinking about resilience measures in coastal cities like New York.

Mental health impacts of flooding: a controlled interrupted time series analysis of prescribing data in England.

PubMed

Milojevic, Ai; Armstrong, Ben; Wilkinson, Paul

2017-10-01

There is emerging evidence that people affected by flooding suffer adverse impacts on their mental well-being, mostly based on self-reports. We examined prescription records for drugs used in the management of common mental disorder among primary care practices located in the vicinity of recent large flood events in England, 2011-2014. A controlled interrupted time series analysis was conducted of the number of prescribing items for antidepressant drugs in the year before and after the flood onset. Pre-post changes were compared by distance of the practice from the inundated boundaries among 930 practices located within 10 km of a flood. After control for deprivation and population density, there was an increase of 0.59% (95% CI 0.24 to 0.94) prescriptions in the postflood year among practices located within 1 km of a flood over and above the change observed in the furthest distance band. The increase was greater in more deprived areas. This study suggests an increase in prescribed antidepressant drugs in the year after flooding in primary care practices close to recent major floods in England. The degree to which the increase is actually concentrated in those flooded can only be determined by more detailed linkage studies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A Bayesian Surrogate for Regional Skew in Flood Frequency Analysis

NASA Astrophysics Data System (ADS)

Kuczera, George

1983-06-01

The problem of how to best utilize site and regional flood data to infer the shape parameter of a flood distribution is considered. One approach to this problem is given in Bulletin 17B of the U.S. Water Resources Council (1981) for the log-Pearson distribution. Here a lesser known distribution is considered, namely, the power normal which fits flood data as well as the log-Pearson and has a shape parameter denoted by λ derived from a Box-Cox power transformation. The problem of regionalizing λ is considered from an empirical Bayes perspective where site and regional flood data are used to infer λ. The distortive effects of spatial correlation and heterogeneity of site sampling variance of λ are explicitly studied with spatial correlation being found to be of secondary importance. The end product of this analysis is the posterior distribution of the power normal parameters expressing, in probabilistic terms, what is known about the parameters given site flood data and regional information on λ. This distribution can be used to provide the designer with several types of information. The posterior distribution of the T-year flood is derived. The effect of nonlinearity in λ on inference is illustrated. Because uncertainty in λ is explicitly allowed for, the understatement in confidence limits due to fixing λ (analogous to fixing log skew) is avoided. Finally, it is shown how to obtain the marginal flood distribution which can be used to select a design flood with specified exceedance probability.

Automated Mapping of Flood Events in the Mississippi River Basin Utilizing NASA Earth Observations

NASA Technical Reports Server (NTRS)

Bartkovich, Mercedes; Baldwin-Zook, Helen Blue; Cruz, Dashiell; McVey, Nicholas; Ploetz, Chris; Callaway, Olivia

2017-01-01

The Mississippi River Basin is the fourth largest drainage basin in the world, and is susceptible to multi-level flood events caused by heavy precipitation, snow melt, and changes in water table levels. Conducting flood analysis during periods of disaster is a challenging endeavor for NASA's Short-term Prediction Research and Transition Center (SPoRT), Federal Emergency Management Agency (FEMA), and the U.S. Geological Survey's Hazards Data Distribution Systems (USGS HDDS) due to heavily-involved research and lack of manpower. During this project, an automated script was generated that performs high-level flood analysis to relieve the workload for end-users. The script incorporated Landsat 8 Operational Land Imager (OLI) tiles and utilized computer-learning techniques to generate accurate water extent maps. The script referenced the Moderate Resolution Imaging Spectroradiometer (MODIS) land-water mask to isolate areas of flood induced waters. These areas were overlaid onto the National Land Cover Database's (NLCD) land cover data, the Oak Ridge National Laboratory's LandScan data, and Homeland Infrastructure Foundation-Level Data (HIFLD) to determine the classification of areas impacted and the population density affected by flooding. The automated algorithm was initially tested on the September 2016 flood event that occurred in Upper Mississippi River Basin, and was then further tested on multiple flood events within the Mississippi River Basin. This script allows end users to create their own flood probability and impact maps for disaster mitigation and recovery efforts.

Flood Catastrophe Model for Designing Optimal Flood Insurance Program: Estimating Location-Specific Premiums in the Netherlands.

PubMed

Ermolieva, T; Filatova, T; Ermoliev, Y; Obersteiner, M; de Bruijn, K M; Jeuken, A

2017-01-01

As flood risks grow worldwide, a well-designed insurance program engaging various stakeholders becomes a vital instrument in flood risk management. The main challenge concerns the applicability of standard approaches for calculating insurance premiums of rare catastrophic losses. This article focuses on the design of a flood-loss-sharing program involving private insurance based on location-specific exposures. The analysis is guided by a developed integrated catastrophe risk management (ICRM) model consisting of a GIS-based flood model and a stochastic optimization procedure with respect to location-specific risk exposures. To achieve the stability and robustness of the program towards floods with various recurrences, the ICRM uses stochastic optimization procedure, which relies on quantile-related risk functions of a systemic insolvency involving overpayments and underpayments of the stakeholders. Two alternative ways of calculating insurance premiums are compared: the robust derived with the ICRM and the traditional average annual loss approach. The applicability of the proposed model is illustrated in a case study of a Rotterdam area outside the main flood protection system in the Netherlands. Our numerical experiments demonstrate essential advantages of the robust premiums, namely, that they: (1) guarantee the program's solvency under all relevant flood scenarios rather than one average event; (2) establish a tradeoff between the security of the program and the welfare of locations; and (3) decrease the need for other risk transfer and risk reduction measures. © 2016 Society for Risk Analysis.

Increased flood risks in the Sacramento-San Joaquin Valleys, CA, under climate change

NASA Astrophysics Data System (ADS)

Das, T.; Hidalgo-Leon, H.; Dettinger, M.; Cayan, D.

2008-12-01

Natural calamities like floods cause immense damages to human society globally, and California is no exception. A simulation analysis of flood generation in the western Sierra Nevada of California was carried out on simulated by the Variable Infiltration Capacity (VIC) hydrologic model under prescribed changes in precipitation (+10 percent) and temperature (+3oC and +5oC) to evaluate likely changes in 3-day flood- frequency curves under climate change. An additional experiment was carried out where snow production was artificially turned off in VIC. All these experiments showed larger flood magnitudes from California's Northern Sierra Nevada (NSN) and Southern Sierra Nevada (SSN), but the changes (for floods larger than the historical 20-year floods) were significant (at 90 percent confidence level) only in the SSN for severe warming cases. Another analysis using downscaled daily precipitation and temperature projections from three General Circulation Models (CNRM CM3, GFDL CM2.1 and NCAR PCM1) and emission scenario A2 as input to VIC yielded a general increase in the 3-days annual maximum flows under climate change. The increases are significant (at 90 percent confidence level) in the SSN for the period 2051-2099 with all the three climate models analyzed. In the NSN the increases are significant only with the CNRM CM3 model. In general, the frequency of floods increases or stayed same under the projected future climates, and some of the projected floods were unprecedentedly large when compared to historical simulations.

Urbanisation and flood vulnerability in the peri-urban interface of Mexico City.

PubMed

Aragón-Durand, Fernando

2007-12-01

Chronic flooding in the Chalco valley, state of Mexico, Mexico, is the outcome of past and present socio-environmental changes which have taken place in Mexico City's south-eastern peri-urban interface. This flooding is the result of a complex interaction between urbanisation in an ex-lacustrine area, permanent ecological deterioration and ground subsidence, poor sanitation and inadequate policy responses. Far from solving the flooding problem, short-term policy responses have created increasingly unsafe conditions for current residents. A socio-historical analysis of disasters reveals the importance of taking into consideration particular social actors and institutions in hazard generation and flood vulnerability over time. This paper analyses three aspects of this flooding: first, the importance of approaching floods from a socio-historical perspective; second, the relation between urbanisation, former policies and flood risk generation; and third, current policy responses to and the failure in the risk management of La Compañía Canal.

RainyDay: An Online, Open-Source Tool for Physically-based Rainfall and Flood Frequency Analysis

NASA Astrophysics Data System (ADS)

Wright, D.; Yu, G.; Holman, K. D.

2017-12-01

Flood frequency analysis in ungaged or changing watersheds typically requires rainfall intensity-duration-frequency (IDF) curves combined with hydrologic models. IDF curves only depict point-scale rainfall depth, while true rainstorms exhibit complex spatial and temporal structures. Floods result from these rainfall structures interacting with watershed features such as land cover, soils, and variable antecedent conditions as well as river channel processes. Thus, IDF curves are traditionally combined with a variety of "design storm" assumptions such as area reduction factors and idealized rainfall space-time distributions to translate rainfall depths into inputs that are suitable for flood hydrologic modeling. The impacts of such assumptions are relatively poorly understood. Meanwhile, modern precipitation estimates from gridded weather radar, grid-interpolated rain gages, satellites, and numerical weather models provide more realistic depictions of rainfall space-time structure. Usage of such datasets for rainfall and flood frequency analysis, however, are hindered by relatively short record lengths. We present RainyDay, an open-source stochastic storm transposition (SST) framework for generating large numbers of realistic rainfall "scenarios." SST "lengthens" the rainfall record by temporal resampling and geospatial transposition of observed storms to extract space-time information from regional gridded rainfall data. Relatively short (10-15 year) records of bias-corrected radar rainfall data are sufficient to estimate rainfall and flood events with much longer recurrence intervals including 100-year and 500-year events. We describe the SST methodology as implemented in RainyDay and compare rainfall IDF results from RainyDay to conventional estimates from NOAA Atlas 14. Then, we demonstrate some of the flood frequency analysis properties that are possible when RainyDay is integrated with a distributed hydrologic model, including robust estimation of flood hazards in a changing watershed. The U.S. Bureau of Reclamation is supporting the development of a web-based variant of RainyDay, a "beta" version of which is available at http://her.cee.wisc.edu/projects/rainyday/.

The near real time Forensic Disaster Analysis of the central European flood in June 2013 - A graphical representation of the main results

NASA Astrophysics Data System (ADS)

Schröter, Kai; Elmer, Florian; Trieselmann, Werner; Kreibich, Heidi; Kunz, Michael; Khazai, Bijan; Dransch, Doris; Wenzel, Friedemann; Zschau, Jochen; Merz, Bruno; Mühr, Bernhard; Kunz-Plapp, Tina; Möhrle, Stella; Bessel, Tina; Fohringer, Joachim

2014-05-01

The Central European flood of June 2013 is one of the most severe flood events that have occurred in Central Europe in the past decades. All major German river basins were affected (Rhine, Danube, and Elbe as well as the smaller Weser catchment).In terms of spatial extent and event magnitude, it was the most severe event at least since 1950. Within the current research focus on near real time forensic disaster analysis, the Center for Disaster Management and Risk Reduction Technology (CEDIM) assessed and analysed the multiple facets of the flood event from the beginning. The aim is to describe the on-going event, analyse the event sources, link the physical characteristics to the impact and consequences of the event and to understand the root causes that turn the physical event into a disaster (or prevent it from becoming disastrous). For the near real time component of this research, tools for rapid assessment and concise presentation of analysis results are essential. This contribution provides a graphical summary of the results of the CEDIM-FDA analyses on the June 2013 flood. It demonstrates the potential of visual representations for improving the communication and hence usability of findings in a rapid, intelligible and expressive way as a valuable supplement to usual event reporting. It is based on analyses of the hydrometeorological sources, the flood pathways (from satellite imagery, data extraction from social media), the resilience of the affected regions, and causal loss analysis. The prototypical representation of the FDA-results for the June 2013 flood provides an important step in the development of graphical event templates for the visualisation of forensic disaster analyses. These are intended to become a standard component of future CEDIM-FDA event activities.

The model of flood control using servqual method and importance performance analysis in Surakarta City – Indonesia

NASA Astrophysics Data System (ADS)

Titi Purwantini, V.; Sutanto, Yusuf

2018-05-01

This research is to create a model of flood control in the city of Surakarta using Servqual method and Importance Performance Analysis. Service quality is generally defined as the overall assessment of a service by the customersor the extent to which a service meets customer’s needs or expectations. The purpose of this study is to find the first model of flood control that is appropriate to the condition of the community. Surakarta This means looking for a model that can provide satisfactory service for the people of Surakarta who are in the location of the flood. The second is to find the right model to improve service performance of Surakarta City Government in serving the people in flood location. The method used to determine the satisfaction of the public on the quality of service is to see the difference in the quality of service expected by the community with the reality. This method is Servqual Method While to assess the performance of city government officials is by comparing the actual performance with the quality of services provided, this method is This means looking for a model that can provide satisfactory service for the people of Surakarta who are in the location of the flood.The second is to find the right model to improve service performance of Surakarta City Government in serving the people in flood location. The method used to determine the satisfaction of the public on the quality of service is to see the difference in the quality of service expected by the community with the reality. This method is Servqual Method While to assess the performance of city government officials is by comparing the actual performance with the quality of services provided, this method is Importance Performance Analysis. Samples were people living in flooded areas in the city of Surakarta. Result this research is Satisfaction = Responsiveness+ Realibility + Assurance + Empathy+ Tangible (Servqual Model) and Importance Performance Analysis is From Cartesian diagram can be made Flood Control Formula as follow: Food Control = High performance

Inclusion of historical information in flood frequency analysis using a Bayesian MCMC technique: a case study for the power dam Orlík, Czech Republic

NASA Astrophysics Data System (ADS)

Gaál, Ladislav; Szolgay, Ján; Kohnová, Silvia; Hlavčová, Kamila; Viglione, Alberto

2010-01-01

The paper deals with at-site flood frequency estimation in the case when also information on hydrological events from the past with extraordinary magnitude are available. For the joint frequency analysis of systematic observations and historical data, respectively, the Bayesian framework is chosen, which, through adequately defined likelihood functions, allows for incorporation of different sources of hydrological information, e.g., maximum annual flood peaks, historical events as well as measurement errors. The distribution of the parameters of the fitted distribution function and the confidence intervals of the flood quantiles are derived by means of the Markov chain Monte Carlo simulation (MCMC) technique. The paper presents a sensitivity analysis related to the choice of the most influential parameters of the statistical model, which are the length of the historical period h and the perception threshold X0. These are involved in the statistical model under the assumption that except for the events termed as ‘historical’ ones, none of the (unknown) peak discharges from the historical period h should have exceeded the threshold X0. Both higher values of h and lower values of X0 lead to narrower confidence intervals of the estimated flood quantiles; however, it is emphasized that one should be prudent of selecting those parameters, in order to avoid making inferences with wrong assumptions on the unknown hydrological events having occurred in the past. The Bayesian MCMC methodology is presented on the example of the maximum discharges observed during the warm half year at the station Vltava-Kamýk (Czech Republic) in the period 1877-2002. Although the 2002 flood peak, which is related to the vast flooding that affected a large part of Central Europe at that time, occurred in the near past, in the analysis it is treated virtually as a ‘historical’ event in order to illustrate some crucial aspects of including information on extreme historical floods into at-site flood frequency analyses.

Landscape Vulnerability Analysis from Historic Lower Mississippi River Flood in 2011

NASA Astrophysics Data System (ADS)

Goodwell, A. E.; Zhu, Z.; Dutta, D.; Greenberg, J.; Kumar, P.; Garcia, M. H.; Rhoads, B. L.; Parker, G.; Berretta, D.; Holmes, R. R.

2012-12-01

This study presents the results of a landscape vulnerability analysis of the Birds Point New Madrid Floodway in southeastern Missouri. The U.S. Army Corps of Engineers intentionally inundated 500 square kilometers of agricultural floodplain in May of 2011 as an emergency flood control measure. We use pre-flood (2005) and post-flood (2011) high resolution Lidar data to establish the landscape impact of the levee breach on the floodplain. The Lidar DEMs were corrected for flight line errors using a Fourier filtering technique, and then subtracted to obtain a differential DEM of erosion and deposition patterns. We use soil erosion characteristics, AVIRIS remote sensing data, and 2D floodplain modeling to analyze the three components of vulnerability: sensitivity, exposure, and adaptive capacity. HydroSed2D (Liu, Landry and García 2008), a 2D flow model, is implemented to simulate flow depths and speeds, or flood exposure, over the entire floodway, as well as smaller sections at increased resolution using a nested grid. We classify woody vegetation based on AVIRIS remote sensing data, and represent vegetated regions in the model as varied values of the Manning's n coefficient. Soil erodibility, vegetation, topography, and flow characteristics are compared to observed landscape changes within the floodplain. Overall, the floodway showed a remarkable resilience to an extreme flood event. When compared to levee breaches on similar rivers in other floods, the lack of newly deposited sediment is noticeable and likely attributable to the presence of a substantial riparian corridor between the main channel of the Mississippi River and the floodway. Although many meander scars indicating former channels of the Mississippi River are apparent in the topography, only one, known as O'Bryan Ridge, experienced high volumes of erosion and deposition due to the flooding. The vulnerability analysis supports the hypothesis this high impact is due to a combination of vulnerability factors such as high flow speed, few localized patches of vegetation, and high soil erodibility at this ridge compared to other similar meander scars. The methodology of this analysis can be used to locate regions of high vulnerability in future floodplain management and flood control, and mitigate potentially catastrophic landscape change.

Scientific relevance of Swiss property insurance data on flood risks and losses

NASA Astrophysics Data System (ADS)

Röthlisberger, Veronika; Bernet, Daniel; Keiler, Margreth

2015-04-01

The databases of Swiss flood insurance companies build a valuable but to date rarely used source of information for flood risk research. Detailed insights into the Swiss flood insurance system are crucial to evaluate the potential of the different databases for scientific analysis. Even though the flood insurance system modalities are mainly regulated on cantonal level there are some common principles that apply throughout Switzerland. First of all coverage against floods (and other particular natural hazards) is an integral part of every fire insurance policy for buildings or contents in Switzerland. This coupling of insurance as well as the statutory obligation to insure buildings in most of the cantons and movables in some of the cantons lead to a very high penetration. Second, in case of damage, the reinstatement costs (value as new) are compensated and third there are no (or little) deductible and co-pay. Thus the different datasets of the flood insurance companies would allow a very comprehensive data analysis. Moreover, insurance companies not only store electronically data about losses (typically date, amount of claims payment, cause of damage, identity of the insured object or policyholder) but also about insured objects. For insured objects the (insured) value and the details on the policy and its holder are the main feature to record. On buildings the insurance companies usually computerize additional information such as location, volume, year of construction or purpose of use. For the 19 (of total 26) cantons with a cantonal monopoly insurer the data of these insurance establishments have the additional value to represent (almost) the entire building stock of the respective canton. However, scientists face a wide range of the opportunities and challenges when using insurance data for flood research. The origin of flood insurance data implies that they are not generated for research but for business management. The presentation will highlighted pro and cons as well as challenges of different aspects such as data compilation and geocoding, spatial and temporal coverage of data, data generation regarding the purpose of efficient and correct management of policies and claims, data protection regulations, differences in the use of technical key terms between risk research and insurance business to answer the questions how relevant and useful are the flood insurance data for flood risk analysis. An outlook will be provided how to encourage the (data) exchange between flood risk business and research.

A Cloud-Based Global Flood Disaster Community Cyber-Infrastructure: Development and Demonstration

NASA Technical Reports Server (NTRS)

Wan, Zhanming; Hong, Yang; Khan, Sadiq; Gourley, Jonathan; Flamig, Zachary; Kirschbaum, Dalia; Tang, Guoqiang

2014-01-01

Flood disasters have significant impacts on the development of communities globally. This study describes a public cloud-based flood cyber-infrastructure (CyberFlood) that collects, organizes, visualizes, and manages several global flood databases for authorities and the public in real-time, providing location-based eventful visualization as well as statistical analysis and graphing capabilities. In order to expand and update the existing flood inventory, a crowdsourcing data collection methodology is employed for the public with smartphones or Internet to report new flood events, which is also intended to engage citizen-scientists so that they may become motivated and educated about the latest developments in satellite remote sensing and hydrologic modeling technologies. Our shared vision is to better serve the global water community with comprehensive flood information, aided by the state-of-the- art cloud computing and crowdsourcing technology. The CyberFlood presents an opportunity to eventually modernize the existing paradigm used to collect, manage, analyze, and visualize water-related disasters.

Hazard Experience, Geophysical Vulnerability, and Flood Risk Perceptions in a Postdisaster City, the Case of New Orleans.

PubMed

Gotham, Kevin Fox; Campanella, Richard; Lauve-Moon, Katie; Powers, Bradford

2018-02-01

This article investigates the determinants of flood risk perceptions in New Orleans, Louisiana (United States), a deltaic coastal city highly vulnerable to seasonal nuisance flooding and hurricane-induced deluges and storm surges. Few studies have investigated the influence of hazard experience, geophysical vulnerability (hazard proximity), and risk perceptions in cities undergoing postdisaster recovery and rebuilding. We use ordinal logistic regression techniques to analyze experiential, geophysical, and sociodemographic variables derived from a survey of 384 residents in seven neighborhoods. We find that residents living in neighborhoods that flooded during Hurricane Katrina exhibit higher levels of perceived risk than those residents living in neighborhoods that did not flood. In addition, findings suggest that flood risk perception is positively associated with female gender, lower income, and direct flood experiences. In conclusion, we discuss the implications of these findings for theoretical and empirical research on environmental risk, flood risk communication strategies, and flood hazards planning. © 2017 Society for Risk Analysis.

Spatiotemporal floodplain mapping and prediction using HEC-RAS - GIS tools: Case of the Mejerda river, Tunisia

NASA Astrophysics Data System (ADS)

Ben Khalfallah, C.; Saidi, S.

2018-06-01

The floods have become a scourge in recent years (Floods of, 2003, 2006, 2009, 2011, and 2012), increasingly frequent and devastating. Tunisia does not escape flooding problems, the flood management requires basically a better knowledge of the phenomenon (flood), and the use of predictive methods. In order to limit this risk, we became interested in hydrodynamics modeling of Medjerda basin. To reach this aim, rainfall distribution is studied and mapped using GIS tools. In addition, flood and return period estimation of rainfall are calculated using Hyfran. Also, Simulations of recent floods are calculated and mapped using HEC-RAS and HEC-GeoRAS for the most recent flood occurred in February-March 2015 in Medjerda basin. The analysis of the results shows a good correlation between simulated parameters and those measured. There is a flood of the river exceeding 240 m3/s (DGRE, 2015) and more flowing sections are observed in the future simulations; for return periods of 10yr, 20yr and 50yr.

The world's largest floods, past and present: Their causes and magnitudes

USGS Publications Warehouse

O'Connor, Jim E.; Costa, John E.

2004-01-01

Floods are among the most powerful forces on earth. Human societies worldwide have lived and died with floods from the very beginning, spawning a prominent role for floods within legends, religions, and history. Inspired by such accounts, geologists, hydrologists, and historians have studied the role of floods on humanity and its supporting ecosystems, resulting in new appreciation for the many-faceted role of floods in shaping our world. Part of this appreciation stems from ongoing analysis of long-term streamflow measurements, such as those recorded by the U.S. Geological Survey's (USGS) streamflow gaging network. But the recognition of the important role of flooding in shaping our cultural and physical landscape also owes to increased understanding of the variety of mechanisms that cause floods and how the types and magnitudes of floods can vary with time and space. The USGS has contributed to this understanding through more than a century of diverse research activities on many aspects of floods, including their causes, effects, and hazards. This Circular summarizes a facet of this research by describing the causes and magnitudes of the world's largest floods, including those measured and described by modern methods in historic times, as well as floods of prehistoric times, for which the only records are those left by the floods themselves.

What are the hydro-meteorological controls on flood characteristics?

NASA Astrophysics Data System (ADS)

Nied, Manuela; Schröter, Kai; Lüdtke, Stefan; Nguyen, Viet Dung; Merz, Bruno

2017-02-01

Flood events can be expressed by a variety of characteristics such as flood magnitude and extent, event duration or incurred loss. Flood estimation and management may benefit from understanding how the different flood characteristics relate to the hydrological catchment conditions preceding the event and to the meteorological conditions throughout the event. In this study, we therefore propose a methodology to investigate the hydro-meteorological controls on different flood characteristics, based on the simulation of the complete flood risk chain from the flood triggering precipitation event, through runoff generation in the catchment, flood routing and possible inundation in the river system and floodplains to flood loss. Conditional cumulative distribution functions and regression tree analysis delineate the seasonal varying flood processes and indicate that the effect of the hydrological pre-conditions, i.e. soil moisture patterns, and of the meteorological conditions, i.e. weather patterns, depends on the considered flood characteristic. The methodology is exemplified for the Elbe catchment. In this catchment, the length of the build-up period, the event duration and the number of gauges undergoing at least a 10-year flood are governed by weather patterns. The affected length and the number of gauges undergoing at least a 2-year flood are however governed by soil moisture patterns. In case of flood severity and loss, the controlling factor is less pronounced. Severity is slightly governed by soil moisture patterns whereas loss is slightly governed by weather patterns. The study highlights that flood magnitude and extent arise from different flood generation processes and concludes that soil moisture patterns as well as weather patterns are not only beneficial to inform on possible flood occurrence but also on the involved flood processes and resulting flood characteristics.

Flood-hazard analysis of four headwater streams draining the Argonne National Laboratory property, DuPage County, Illinois

USGS Publications Warehouse

Soong, David T.; Murphy, Elizabeth A.; Straub, Timothy D.; Zeeb, Hannah L.

2016-11-22

Results of a flood-hazard analysis conducted by the U.S. Geological Survey, in cooperation with the Argonne National Laboratory, for four headwater streams within the Argonne National Laboratory property indicate that the 1-percent and 0.2-percent annual exceedance probability floods would cause multiple roads to be overtopped. Results indicate that most of the effects on the infrastructure would be from flooding of Freund Brook. Flooding on the Northeast and Southeast Drainage Ways would be limited to overtopping of one road crossing for each of those streams. The Northwest Drainage Way would be the least affected with flooding expected to occur in open grass or forested areas.The Argonne Site Sustainability Plan outlined the development of hydrologic and hydraulic models and the creation of flood-plain maps of the existing site conditions as a first step in addressing resiliency to possible climate change impacts as required by Executive Order 13653 “Preparing the United States for the Impacts of Climate Change.” The Hydrological Simulation Program-FORTRAN is the hydrologic model used in the study, and the Hydrologic Engineering Center‒River Analysis System (HEC–RAS) is the hydraulic model. The model results were verified by comparing simulated water-surface elevations to observed water-surface elevations measured at a network of five crest-stage gages on the four study streams. The comparison between crest-stage gage and simulated elevations resulted in an average absolute difference of 0.06 feet and a maximum difference of 0.19 feet.In addition to the flood-hazard model development and mapping, a qualitative stream assessment was conducted to evaluate stream channel and substrate conditions in the study reaches. This information can be used to evaluate erosion potential.

Designing a Software for Flood Risk Assessment Based on Multi Criteria Desicion Analysis and Information Diffusion Methods

NASA Astrophysics Data System (ADS)

Musaoglu, N.; Saral, A.; Seker, D. Z.

2012-12-01

Flooding is one of the major natural disasters not only in Turkey but also in all over the world and it causes serious damage and harm. It is estimated that of the total economic loss caused by all kinds of disasters, 40% was due to floods. In July 1995, the Ayamama Creek in Istanbul was flooded, the insurance sector received around 1,200 claims notices during that period, insurance companies had to pay a total of $40 million for claims. In 2009, the same creek was flooded again and killed 31 people over two days and insurance firms paid for damages around cost €150 million for claims. To solve these kinds of problems modern tools such as GIS and Remote Sensing should be utilized. In this study, a software was designed for the flood risk analysis with Analytic Hierarchy Process (AHP) and Information Diffusion( InfoDif) methods.In the developed sofware, five evaluation criterias were taken into account, which were slope, aspect, elevation, geology and land use which were extracted from the satellite sensor data. The Digital Elevation Model (DEM) of the Ayamama River Basin was acquired from the SPOT 5 satellite image with 2.5 meter spatial resolution. Slope and aspect values of the study basin were extracted from this DEM. The land use of the Ayamama Creek was obtained by performing object-oriented nearest neighbor classification method by image segmentation on SPOT 5 image dated 2010. All produced data were used as an input for the part of Multi Criteria Desicion Analysis (MCDA) method of this software. Criterias and their each sub criteras were weighted and flood vulnerability was determined with MCDA-AHP. Also, daily flood data was collected from Florya Meteorological Station, between 1975 to 2009 years and the daily flood peak discharge was calculated with the method of Soil Conservation Service-Curve Number (SCS-CN) and were used as an input in the software for the part of InfoDif.Obtained results were verified using ground truth data and it has been clearly seen that the developed (TRA) software which uses two different methods for flood risk analysis, can be more effective for achieving different decision problems, from conventional techniques and produce more reliable results in a short time.; Study Area

Use of Natural and Nature-Based Features for Coastal Resilience

NASA Astrophysics Data System (ADS)

Piercy, C.; Bridges, T. S.

2017-12-01

Natural and Nature-Based Features (NNBF) have been used for decades to support a variety of objectives in coastal systems. Beach and dune projects have been a longstanding part of flood risk reduction strategies in Europe, the United States and elsewhere. Coastal restoration projects supporting wetlands, seagrass, oysters and other habitats and communities have been undertaken around the world to restore ecosystem functions. In more recent years there has been a growing interest in developing a technically sound engineering approach for integrating NNBF, in combination with conventional flood defense systems (e.g., levees, seawalls, etc.), for more comprehensive and sustainable flood defense systems. This interest was further stimulated by the outcomes of recent storm events, including Hurricanes Katrina and Sandy in the United States, which have given rise to a range of studies and projects focused on the role of coastal landscape features in flood risk management. The global dialogue that has been underway for several years—including within the Engineering with Nature program in the United States—has revealed the demand for an authoritative guidance on the use of NNBF in shoreline management. The U.S. Army Corps of Engineers has initiated a collaborative project involving participants from several countries and organizations representing government, academia, and the private sector to develop international guidelines to inform the planning, design, construction, and operation or NNBF projects to support coastal resilience. This paper will describe the key issues and objectives informing the work of the international team that is developing the guidelines.

A framework for multivariate data-based at-site flood frequency analysis: Essentiality of the conjugal application of parametric and nonparametric approaches

NASA Astrophysics Data System (ADS)

Vittal, H.; Singh, Jitendra; Kumar, Pankaj; Karmakar, Subhankar

2015-06-01

In watershed management, flood frequency analysis (FFA) is performed to quantify the risk of flooding at different spatial locations and also to provide guidelines for determining the design periods of flood control structures. The traditional FFA was extensively performed by considering univariate scenario for both at-site and regional estimation of return periods. However, due to inherent mutual dependence of the flood variables or characteristics [i.e., peak flow (P), flood volume (V) and flood duration (D), which are random in nature], analysis has been further extended to multivariate scenario, with some restrictive assumptions. To overcome the assumption of same family of marginal density function for all flood variables, the concept of copula has been introduced. Although, the advancement from univariate to multivariate analyses drew formidable attention to the FFA research community, the basic limitation was that the analyses were performed with the implementation of only parametric family of distributions. The aim of the current study is to emphasize the importance of nonparametric approaches in the field of multivariate FFA; however, the nonparametric distribution may not always be a good-fit and capable of replacing well-implemented multivariate parametric and multivariate copula-based applications. Nevertheless, the potential of obtaining best-fit using nonparametric distributions might be improved because such distributions reproduce the sample's characteristics, resulting in more accurate estimations of the multivariate return period. Hence, the current study shows the importance of conjugating multivariate nonparametric approach with multivariate parametric and copula-based approaches, thereby results in a comprehensive framework for complete at-site FFA. Although the proposed framework is designed for at-site FFA, this approach can also be applied to regional FFA because regional estimations ideally include at-site estimations. The framework is based on the following steps: (i) comprehensive trend analysis to assess nonstationarity in the observed data; (ii) selection of the best-fit univariate marginal distribution with a comprehensive set of parametric and nonparametric distributions for the flood variables; (iii) multivariate frequency analyses with parametric, copula-based and nonparametric approaches; and (iv) estimation of joint and various conditional return periods. The proposed framework for frequency analysis is demonstrated using 110 years of observed data from Allegheny River at Salamanca, New York, USA. The results show that for both univariate and multivariate cases, the nonparametric Gaussian kernel provides the best estimate. Further, we perform FFA for twenty major rivers over continental USA, which shows for seven rivers, all the flood variables followed nonparametric Gaussian kernel; whereas for other rivers, parametric distributions provide the best-fit either for one or two flood variables. Thus the summary of results shows that the nonparametric method cannot substitute the parametric and copula-based approaches, but should be considered during any at-site FFA to provide the broadest choices for best estimation of the flood return periods.

Mid-Holocene palaeoflood events recorded at the Zhongqiao Neolithic cultural site in the Jianghan Plain, middle Yangtze River Valley, China

NASA Astrophysics Data System (ADS)

Wu, Li; Zhu, Cheng; Ma, Chunmei; Li, Feng; Meng, Huaping; Liu, Hui; Li, Linying; Wang, Xiaocui; Sun, Wei; Song, Yougui

2017-10-01

Palaeo-hydrological and archaeological investigations were carried out in the Jianghan Plain in the middle reaches of the Yangtze River. Based on a comparative analysis of modern flood sediments and multidisciplinary approaches such as AMS14C and archaeological dating, zircon micromorphology, grain size, magnetic susceptibility, and geochemistry, we identified palaeoflood sediments preserved at the Zhongqiao archaeological site. The results indicate that three palaeoflood events (i.e. 4800-4597, 4479-4367, and 4168-3850 cal. yr BP) occurred at the Zhongqiao Site. Comparisons of palaeoflood deposit layers at a number of Neolithic cultural sites show that two extraordinary palaeoflood events occurred in the Jianghan Plain during approximately 4900-4600 cal. yr BP (i.e.mid-late Qujialing cultural period) and 4100-3800 cal. yr BP (i.e. from late Shijiahe cultural period to the Xia Dynasty). Further analysis of the environmental context suggests that these flooding events might have been connected with great climate variability during approximately 5000-4500 cal. yr BP and at ca. 4000 cal. yr BP. These two palaeoflood events were closely related to the expansion of the Jianghan lakes driven by the climatic change, which in turn influenced the rise and fall of the Neolithic cultures in the middle reaches of the Yangtze River. Other evidence also suggests that the intensified discrepancy between social development and environmental change processes (especially the hydrological process) during the late Shijiahe cultural period might be the key factor causing the collapse of the Shijiahe Culture. The extraordinary floods related to the climatic anomaly at ca. 4000 cal. yr BP and political conflicts from internal or other cultural areas all accelerated the collapse of the Shijiahe Culture.

Flood risk in a changing world - a coupled transdisciplinary modelling framework for flood risk assessment in an Alpine study area

NASA Astrophysics Data System (ADS)

Huttenlau, Matthias; Schneeberger, Klaus; Winter, Benjamin; Pazur, Robert; Förster, Kristian; Achleitner, Stefan; Bolliger, Janine

2017-04-01

Devastating flood events have caused substantial economic damage across Europe during past decades. Flood risk management has therefore become a topic of crucial interest across state agencies, research communities and the public sector including insurances. There is consensus that mitigating flood risk relies on impact assessments which quantitatively account for a broad range of aspects in a (changing) environment. Flood risk assessments which take into account the interaction between the drivers climate change, land-use change and socio-economic change might bring new insights to the understanding of the magnitude and spatial characteristic of flood risks. Furthermore, the comparative assessment of different adaptation measures can give valuable information for decision-making. With this contribution we present an inter- and transdisciplinary research project aiming at developing and applying such an impact assessment relying on a coupled modelling framework for the Province of Vorarlberg in Austria. Stakeholder engagement ensures that the final outcomes of our study are accepted and successfully implemented in flood management practice. The study addresses three key questions: (i) What are scenarios of land- use and climate change for the study area? (ii) How will the magnitude and spatial characteristic of future flood risk change as a result of changes in climate and land use? (iii) Are there spatial planning and building-protection measures which effectively reduce future flood risk? The modelling framework has a modular structure comprising modules (i) climate change, (ii) land-use change, (iii) hydrologic modelling, (iv) flood risk analysis, and (v) adaptation measures. Meteorological time series are coupled with spatially explicit scenarios of land-use change to model runoff time series. The runoff time series are combined with impact indicators such as building damages and results are statistically assessed to analyse flood risk scenarios. Thus, the regional flood risk can be expressed in terms of expected annual damage and damages associated with a low probability of occurrence. We consider building protection measures explicitly as part of the consequence analysis of flood risk whereas spatial planning measures are already considered as explicit scenarios in the course of land-use change modelling.

Comparing the index-flood and multiple-regression methods using L-moments

NASA Astrophysics Data System (ADS)

Malekinezhad, H.; Nachtnebel, H. P.; Klik, A.

In arid and semi-arid regions, the length of records is usually too short to ensure reliable quantile estimates. Comparing index-flood and multiple-regression analyses based on L-moments was the main objective of this study. Factor analysis was applied to determine main influencing variables on flood magnitude. Ward’s cluster and L-moments approaches were applied to several sites in the Namak-Lake basin in central Iran to delineate homogeneous regions based on site characteristics. Homogeneity test was done using L-moments-based measures. Several distributions were fitted to the regional flood data and index-flood and multiple-regression methods as two regional flood frequency methods were compared. The results of factor analysis showed that length of main waterway, compactness coefficient, mean annual precipitation, and mean annual temperature were the main variables affecting flood magnitude. The study area was divided into three regions based on the Ward’s method of clustering approach. The homogeneity test based on L-moments showed that all three regions were acceptably homogeneous. Five distributions were fitted to the annual peak flood data of three homogeneous regions. Using the L-moment ratios and the Z-statistic criteria, GEV distribution was identified as the most robust distribution among five candidate distributions for all the proposed sub-regions of the study area, and in general, it was concluded that the generalised extreme value distribution was the best-fit distribution for every three regions. The relative root mean square error (RRMSE) measure was applied for evaluating the performance of the index-flood and multiple-regression methods in comparison with the curve fitting (plotting position) method. In general, index-flood method gives more reliable estimations for various flood magnitudes of different recurrence intervals. Therefore, this method should be adopted as regional flood frequency method for the study area and the Namak-Lake basin in central Iran. To estimate floods of various return periods for gauged catchments in the study area, the mean annual peak flood of the catchments may be multiplied by corresponding values of the growth factors, and computed using the GEV distribution.

Parsimonious nonstationary flood frequency analysis

NASA Astrophysics Data System (ADS)

Serago, Jake M.; Vogel, Richard M.

2018-02-01

There is now widespread awareness of the impact of anthropogenic influences on extreme floods (and droughts) and thus an increasing need for methods to account for such influences when estimating a frequency distribution. We introduce a parsimonious approach to nonstationary flood frequency analysis (NFFA) based on a bivariate regression equation which describes the relationship between annual maximum floods, x, and an exogenous variable which may explain the nonstationary behavior of x. The conditional mean, variance and skewness of both x and y = ln (x) are derived, and combined with numerous common probability distributions including the lognormal, generalized extreme value and log Pearson type III models, resulting in a very simple and general approach to NFFA. Our approach offers several advantages over existing approaches including: parsimony, ease of use, graphical display, prediction intervals, and opportunities for uncertainty analysis. We introduce nonstationary probability plots and document how such plots can be used to assess the improved goodness of fit associated with a NFFA.

Public Policy and Private Enterprise in the Development of Flood Plains: A Laboratory Exercise in Physical Geography

ERIC Educational Resources Information Center

Nunnally, Nelson R.; And Others

1974-01-01

This activity is designed to introduce college students to the concept of floods as natural hazards, to flood frequency analysis, to hazard adjustment, and to the mechanics of public policy formulation through a six hour laboratory exercise, culminating in a simulation game. (JH)

Novel Flood Detection and Analysis Method Using Recurrence Property

NASA Astrophysics Data System (ADS)

Wendi, Dadiyorto; Merz, Bruno; Marwan, Norbert

2016-04-01

Temporal changes in flood hazard are known to be difficult to detect and attribute due to multiple drivers that include processes that are non-stationary and highly variable. These drivers, such as human-induced climate change, natural climate variability, implementation of flood defence, river training, or land use change, could impact variably on space-time scales and influence or mask each other. Flood time series may show complex behavior that vary at a range of time scales and may cluster in time. This study focuses on the application of recurrence based data analysis techniques (recurrence plot) for understanding and quantifying spatio-temporal changes in flood hazard in Germany. The recurrence plot is known as an effective tool to visualize the dynamics of phase space trajectories i.e. constructed from a time series by using an embedding dimension and a time delay, and it is known to be effective in analyzing non-stationary and non-linear time series. The emphasis will be on the identification of characteristic recurrence properties that could associate typical dynamic behavior to certain flood situations.

Regional reconstruction of flash flood history in the Guadarrama range (Central System, Spain).

PubMed

Rodriguez-Morata, C; Ballesteros-Cánovas, J A; Trappmann, D; Beniston, M; Stoffel, M

2016-04-15

Flash floods are a common natural hazard in Mediterranean mountain environments and responsible for serious economic and human disasters. The study of flash flood dynamics and their triggers is a key issue; however, the retrieval of historical data is often limited in mountain regions as a result of short time series and the systematic lack of historical data. In this study, we attempt to overcome data deficiency by supplementing existing records with dendrogeomorphic techniques which were employed in seven mountain streams along the northern slopes of the Guadarrama Mountain range. Here we present results derived from the tree-ring analysis of 117 samples from 63 Pinus sylvestris L. trees injured by flash floods, to complement existing flash flood records covering the last ~200years and comment on their hydro-meteorological triggers. To understand the varying number of reconstructed flash flood events in each of the catchments, we also performed a comparative analysis of geomorphic catchment characteristics, land use evolution and forest management. Furthermore, we discuss the limitations of dendrogeomorphic techniques applied in managed forests. Copyright © 2016 Elsevier B.V. All rights reserved.

Hydrological Analysis for Inflow Forecasting into Temengor Dam

NASA Astrophysics Data System (ADS)

Najid, MI; Sidek, LM; Hidayah, B.; Roseli, ZA

2016-03-01

These days, natural disaster such as flood is the main concern for hydrologists. One of solutions in understanding the reason of flood is by prediction of the event sooner than normal occurrence. One of the criteria is lead time or travel time that is important in the study of fresh waters and flood events. Therefore, estimation of lead or travel time for flood event can be beneficial primary information. The objective of this study is to estimate the lead time or travel time for outlet of Temengor dam in Malaysia. Tenaga Nasional Berhad (TNB) Sungai Perak dam operation has the main contribution on decision support for early water released and flood warning to authorities and locals resident for in the down streams area. For this study, hydrological analysis carried out will help to determine which years that give more rainfall contribution into the reservoir. Rainfall contribution of reservoir help to understanding rainfall distribution and peak discharge on that period. It also help for calibration of forecasting model system for better accuracy of flood hydrograph. There may be various methods to determine the rainfall contribution of catchment. The result has shown that, the rainfall contribution for Temengor catchment, is more on November in each year which is the monsoon season in Malaysia. TNB dam operational decision support systems can prepare and be more aware at this time for flood control and flood mitigation.

Influences on Adaptive Planning to Reduce Flood Risks among Parishes in South Louisiana.

PubMed

Paille, Mary; Reams, Margaret; Argote, Jennifer; Lam, Nina S-N; Kirby, Ryan

2016-02-01

Residents of south Louisiana face a range of increasing, climate-related flood exposure risks that could be reduced through local floodplain management and hazard mitigation planning. A major incentive for community planning to reduce exposure to flood risks is offered by the Community Rating System (CRS) of the National Flood Insurance Program (NFIP). The NFIP encourages local collective action by offering reduced flood insurance premiums for individual policy holders of communities where suggested risk-reducing measures have been implemented. This preliminary analysis examines the extent to which parishes (counties) in southern Louisiana have implemented the suggested policy actions and identifies key factors that account for variation in the implementation of the measures. More measures implemented results in higher CRS scores. Potential influences on scores include socioeconomic attributes of residents, government capacity, average elevation and past flood events. The results of multiple regression analysis indicate that higher CRS scores are associated most closely with higher median housing values. Furthermore, higher scores are found in parishes with more local municipalities that participate in the CRS program. The number of floods in the last five years and the revenue base of the parish does not appear to influence CRS scores. The results shed light on the conditions under which local adaptive planning to mitigate increasing flood risks is more likely to be implemented and offer insights for program administrators, researchers and community stakeholders.

Influences on Adaptive Planning to Reduce Flood Risks among Parishes in South Louisiana

PubMed Central

Paille, Mary; Reams, Margaret; Argote, Jennifer; Lam, Nina S.-N.; Kirby, Ryan

2016-01-01

Residents of south Louisiana face a range of increasing, climate-related flood exposure risks that could be reduced through local floodplain management and hazard mitigation planning. A major incentive for community planning to reduce exposure to flood risks is offered by the Community Rating System (CRS) of the National Flood Insurance Program (NFIP). The NFIP encourages local collective action by offering reduced flood insurance premiums for individual policy holders of communities where suggested risk-reducing measures have been implemented. This preliminary analysis examines the extent to which parishes (counties) in southern Louisiana have implemented the suggested policy actions and identifies key factors that account for variation in the implementation of the measures. More measures implemented results in higher CRS scores. Potential influences on scores include socioeconomic attributes of residents, government capacity, average elevation and past flood events. The results of multiple regression analysis indicate that higher CRS scores are associated most closely with higher median housing values. Furthermore, higher scores are found in parishes with more local municipalities that participate in the CRS program. The number of floods in the last five years and the revenue base of the parish does not appear to influence CRS scores. The results shed light on the conditions under which local adaptive planning to mitigate increasing flood risks is more likely to be implemented and offer insights for program administrators, researchers and community stakeholders. PMID:27330828

Economic Conflict and National Security Research

DTIC Science & Technology

1977-02-22

international affairs, such as a change in rules governing international financial prac- tices (i.e., repayment of debts, free movement of assets, etc...conflict. This step subsumes such questions as whether or n-ot an act of economic conflict will result in a hot war, the collapse of international financial ...disrupt an adver- sary’s economy; * Wrecking a nation’s financial institutions by flooding the country with counterfeit money and/or duplicate credit cardst

Designing an 'expert knowledge' based approach for the quantification of historical floods - the case study of the Kinzig catchment in Southwest Germany

NASA Astrophysics Data System (ADS)

Bösmeier, Annette; Glaser, Rüdiger; Stahl, Kerstin; Himmelsbach, Iso; Schönbein, Johannes

2017-04-01

Future estimations of flood hazard and risk for developing optimal coping and adaption strategies inevitably include considerations of the frequency and magnitude of past events. Methods of historical climatology represent one way of assessing flood occurrences beyond the period of instrumental measurements and can thereby substantially help to extend the view into the past and to improve modern risk analysis. Such historical information can be of additional value and has been used in statistical approaches like Bayesian flood frequency analyses during recent years. However, the derivation of quantitative values from vague descriptive information of historical sources remains a crucial challenge. We explored possibilities of parametrization of descriptive flood related data specifically for the assessment of historical floods in a framework that combines a hermeneutical approach with mathematical and statistical methods. This study forms part of the transnational, Franco-German research project TRANSRISK2 (2014 - 2017), funded by ANR and DFG, with the focus on exploring the floods history of the last 300 years for the regions of Upper and Middle Rhine. A broad data base of flood events had been compiled, dating back to AD 1500. The events had been classified based on hermeneutical methods, depending on intensity, spatial dimension, temporal structure, damages and mitigation measures associated with the specific events. This indexed database allowed the exploration of a link between descriptive data and quantitative information for the overlapping time period of classified floods and instrumental measurements since the end of the 19th century. Thereby, flood peak discharges as a quantitative measure of the severity of a flood were used to assess the discharge intervals for flood classes (upper and lower thresholds) within different time intervals for validating the flood classification, as well as examining the trend in the perception threshold over time. Furthermore, within a suitable time period, flood classes and other quantifiable indicators of flood intensity (number of damaged locations mentioned in historical sources, general availability of reports associated with a specific event) were combined with available peak discharges measurements. We argue that this information can be considered as 'expert knowledge' and used it to develop a fuzzy rule based model for deriving peak discharge estimates of pre-instrumental events that can finally be introduced into a flood frequency analysis.

Is there really "nothing you can do"? Pathways to enhanced flood-risk preparedness

NASA Astrophysics Data System (ADS)

Fox-Rogers, Linda; Devitt, Catherine; O'Neill, Eoin; Brereton, Finbarr; Clinch, J. Peter

2016-12-01

Whilst policy makers have tended to adopt an 'information-deficit model' to bolster levels of flood-risk preparedness primarily though communication strategies promoting awareness, the assumed causal relation between awareness and preparedness is empirically weak. As such, there is a growing interest amongst scholars and policy makers alike to better understand why at-risk individuals are underprepared. In this vein, empirical studies, typically employing quantitative methods, have tended to focus on exploring the extent to which flood-risk preparedness levels vary depending not only on socio-demographic variables, but also (and increasingly so) the perceptual factors that influence flood risk preparedness. This study builds upon and extends this body of research by offering a more solution-focused approach that seeks to identify how pathways to flood-risk preparedness can be opened up. Specifically, through application of a qualitative methodology, we seek to explore how the factors that negatively influence flood-risk preparedness can be addressed to foster a shift towards greater levels of mitigation behaviour. In doing so, we focus our analysis on an urban community in Ireland that is identified as 'at risk' of flash flooding and is currently undergoing significant flood relief works. In this regard, the case study offers an interesting laboratory to explore how attitudes towards flood-risk preparedness at the individual level are being influenced within the context of a flood relief scheme that is only partially constructed. In order to redress the dearth of theoretically informed qualitative studies in this field, we draw on Protection Motivation Theory (PMT) to help guide our analysis and make sense of our results. Our findings demonstrate that flood-risk preparedness can be undermined by low levels of efficacy amongst individuals in terms of the preparedness measures available to them and their own personal capacity to implement them. We also elucidate that the 'levee effect' can occur before engineered flood defences are fully constructed as the flood relief works within our case study are beginning to affect people's perception of flood risk in the case study area. We conclude by arguing that (1) individuals' coping appraisals need to be enhanced through communication strategies and other interventions which highlight that future floods may not replicate past events; and (2) the concept of residual risk needs to be communicated at all stages of a flood relief scheme, not just upon completion.

The efficiency of asset management strategies to reduce urban flood risk.

PubMed

ten Veldhuis, J A E; Clemens, F H L R

2011-01-01

In this study, three asset management strategies were compared with respect to their efficiency to reduce flood risk. Data from call centres at two municipalities were used to quantify urban flood risks associated with three causes of urban flooding: gully pot blockage, sewer pipe blockage and sewer overloading. The efficiency of three flood reduction strategies was assessed based on their effect on the causes contributing to flood risk. The sensitivity of the results to uncertainty in the data source, citizens' calls, was analysed through incorporation of uncertainty ranges taken from customer complaint literature. Based on the available data it could be shown that increasing gully pot blockage is the most efficient action to reduce flood risk, given data uncertainty. If differences between cause incidences are large, as in the presented case study, call data are sufficient to decide how flood risk can be most efficiently reduced. According to the results of this analysis, enlargement of sewer pipes is not an efficient strategy to reduce flood risk, because flood risk associated with sewer overloading is small compared to other failure mechanisms.

Proteomic and Biochemical Analyses of the Cotyledon and Root of Flooding-Stressed Soybean Plants

PubMed Central

Komatsu, Setsuko; Makino, Takahiro; Yasue, Hiroshi

2013-01-01

Background Flooding significantly reduces the growth and grain yield of soybean plants. Proteomic and biochemical techniques were used to determine whether the function of cotyledon and root is altered in soybean under flooding stress. Results Two-day-old soybean plants were flooded for 2 days, after which the proteins from root and cotyledon were extracted for proteomic analysis. In response to flooding stress, the abundance of 73 and 28 proteins was significantly altered in the root and cotyledon, respectively. The accumulation of only one protein, 70 kDa heat shock protein (HSP70) (Glyma17g08020.1), increased in both organs following flooding. The ratio of protein abundance of HSP70 and biophoton emission in the cotyledon was higher than those detected in the root under flooding stress. Computed tomography and elemental analyses revealed that flooding stress decreases the number of calcium oxalate crystal the cotyledon, indicating calcium ion was elevated in the cotyledon under flooding stress. Conclusion These results suggest that calcium might play one role through HSP70 in the cotyledon under flooding stress. PMID:23799004

Predicting geomorphically-induced flood risk for the Nepalese Terai communities

NASA Astrophysics Data System (ADS)

Dingle, Elizabeth; Creed, Maggie; Attal, Mikael; Sinclair, Hugh; Mudd, Simon; Borthwick, Alistair; Dugar, Sumit; Brown, Sarah

2017-04-01

Rivers sourced from the Himalaya irrigate the Indo-Gangetic Plain via major river networks that support 10% of the global population. However, many of these rivers are also the source of devastating floods. During the 2014 Karnali River floods in west Nepal, the Karnali rose to around 16 m at Chisapani (where it enters the Indo-Gangetic Plain), 1 m higher than the previous record in 1983; the return interval for this event was estimated to be 1000 years. Flood risk may currently be underestimated in this region, primarily because changes to the channel bed are not included when identifying areas at risk of flooding from events of varying recurrence intervals. Our observations in the field, corroborated by satellite imagery, show that river beds are highly mobile and constantly evolve through each monsoon. Increased bed levels due to sediment aggradation decreases the capacity of the river, increasing significantly the risk of devastating flood events; we refer to these as 'geomorphically-induced floods'. Major, short-lived episodes of sediment accumulation in channels are caused by stochastic variability in sediment flux generated by storms, earthquakes and glacial outburst floods from upstream parts of the catchment. Here, we generate a field-calibrated, geomorphic flood risk model for varying upstream scenarios, and predict changing flood risk for the Karnali River. A numerical model is used to carry out a sensitivity analysis of changes in channel geometry (particularly aggradation or degradation) based on realistic flood scenarios. In these scenarios, water and sediment discharge are varied within a range of plausible values, up to extreme sediment and water fluxes caused by widespread landsliding and/or intense monsoon precipitation based on existing records. The results of this sensitivity analysis will be used to inform flood hazard maps of the Karnali River floodplain and assess the vulnerability of the populations in the region.

Characterization of microbial and metal contamination in flooded New York City neighborhoods following Superstorm Sandy

NASA Astrophysics Data System (ADS)

Dueker, M.; O'Mullan, G. D.; Sahajpal, R.

2013-12-01

Large scale flooding of waterfront neighborhoods occurred in New York City (NYC) during Superstorm Sandy. While NYC waterways commonly experience combined sewer overflow (CSO) and associated water quality degradation during rain storms, Superstorm Sandy was unique in that these potentially contaminated waters were transported over the banks and into city streets and buildings. Sampling of waterways, storm debris on city streets, and flood water trapped in building basements occurred in the days following Sandy, including in neighborhoods bordering the Gowanus Canal and Newtown Creek, which are both Superfund sites known to frequently contain high levels of sewage associated bacteria and metal contamination. Samples enumerated for the sewage indicating bacterium, Enterococcus, suggest that well-flushed waterways recovered quickly from sewage contamination in the days following the storm, with Enterococci concentrations similar to background levels measured before flooding occurred. In contrast, storm debris on city streets and waters from flooded basements had much higher levels of sewage-associated bacteria days after flooding occurred. Analysis of 180,000 bacterial 16S rRNA gene sequences obtained from flood water samples and flood debris confirmed the presence of bacterial genera often associated with sewage impacted samples (e.g. Escherichia, Streptococcus, Clostridium, Trichococcus, Aeromonas) and a community composition similar to CSO discharge. Elemental analysis suggests low levels of metal contamination in most flood water, but much higher levels of Cu, Pb, and Cr were found in leach from some storm debris samples found adjacent to the Newtown Creek and Gowanus Canal superfund sites. These data suggest a rapid recovery of water quality in local waterways after Superstorm Sandy, but that trapped flood water and debris samples in urban neighborhoods retained elevated levels of microbial sewage pollution, and in some cases metal pollution, days after that waterway recovery. These findings indicate a potentially significant risk to local populations exposed to trapped flood waters and debris in the aftermath of urban waterway flooding events.

'Are you prepared?' Representations and management of floods in Lomanikoro, Rewa (Fiji).

PubMed

Nolet, Emilie

2016-10-01

The islands of Fiji, in the Western Pacific, are exposed to a wide range of natural hazards. Tropical storms and associated floods are recurring natural phenomena, but it has been regularly alleged that Fijians lack preparation, over-rely on state assistance in post-disaster situations or engage in risky behaviours that aggravate the negative impact of floods. Risk reduction strategies, which are now implemented by government authorities and international organisations, heavily promote the principle of 'community preparedness'. Both community awareness programmes and capacity-building programmes are conducted throughout the country in the most vulnerable communities. This paper analyses how the inhabitants of Lomanikoro village, in the low areas of the Rewa Delta, perceive and manage existing flood risks. It examines social and cultural factors that contribute to shape risk response locally-in particular, why villagers may be reluctant to adopt some recommended preparedness measures and resettle in higher, safer zones. © 2016 The Author(s). Disasters © Overseas Development Institute, 2016.

Global Flood Response Using Satellite Rainfall Information Coupled with Land Surface and Routing Models

NASA Astrophysics Data System (ADS)

Adler, R. F.; Wu, H.

2016-12-01

The Global Flood Monitoring System (GFMS) (http://flood.umd.edu) has been developed and used in recent years to provide real-time flood detection, streamflow estimates and inundation calculations for most of the globe. The GFMS is driven by satellite-based precipitation, with the accuracy of the flood estimates being primarily dependent on the accuracy of the precipitation analyses and the land surface and routing models used. The routing calculations are done at both 12 km and 1 km resolution. Users of GFMS results include international and national flood response organizations. The devastating floods in October 2015 in South Carolina are analyzed indicating that the GFMS estimated streamflow is accurate and useful indicating significant flooding in the upstream basins. Further downstream the GFMS streamflow underestimates due to the presence of dams which are not accounted for in GFMS. Other examples are given for Yemen and Somalia and for Sri Lanka and southern India. A forecast flood event associated with a typhoon hitting Taiwan is also examined. One-kilometer resolution inundation mapping from GFMS holds the promise of highly useful information for flood disaster response. The algorithm is briefly described and examples are shown for recent cases where inundation estimates available from optical and Synthetic Aperture Radar (SAR) satellite sensors are available. For a case of significant flooding in Texas in May and June along the Brazos River the GFMS calculated streamflow compares favorably with the observed. Available Landsat-based (May 28) and MODIS-based (June 2) inundation analyses from U. of Colorado shows generally good agreement with the GFMS inundation calculation in most of the area where skies were clear and the optical techniques could be applied. The GFMS provides very useful disaster response information on a timely basis. However, there is still significant room for improvement, including improved precipitation information from NASA's Global Precipitation Measurement (GPM) mission, inclusion of dam algorithms in the routing model and integration with or assimilation of observed flood extent from satellite optical and SAR sensors.

Automating the evaluation of flood damages: methodology and potential gains

NASA Astrophysics Data System (ADS)

Eleutério, Julian; Martinez, Edgar Daniel

2010-05-01

The evaluation of flood damage potential consists of three main steps: assessing and processing data, combining data and calculating potential damages. The first step consists of modelling hazard and assessing vulnerability. In general, this step of the evaluation demands more time and investments than the others. The second step of the evaluation consists of combining spatial data on hazard with spatial data on vulnerability. Geographic Information System (GIS) is a fundamental tool in the realization of this step. GIS software allows the simultaneous analysis of spatial and matrix data. The third step of the evaluation consists of calculating potential damages by means of damage-functions or contingent analysis. All steps demand time and expertise. However, the last two steps must be realized several times when comparing different management scenarios. In addition, uncertainty analysis and sensitivity test are made during the second and third steps of the evaluation. The feasibility of these steps could be relevant in the choice of the extent of the evaluation. Low feasibility could lead to choosing not to evaluate uncertainty or to limit the number of scenario comparisons. Several computer models have been developed over time in order to evaluate the flood risk. GIS software is largely used to realise flood risk analysis. The software is used to combine and process different types of data, and to visualise the risk and the evaluation results. The main advantages of using a GIS in these analyses are: the possibility of "easily" realising the analyses several times, in order to compare different scenarios and study uncertainty; the generation of datasets which could be used any time in future to support territorial decision making; the possibility of adding information over time to update the dataset and make other analyses. However, these analyses require personnel specialisation and time. The use of GIS software to evaluate the flood risk requires personnel with a double professional specialisation. The professional should be proficient in GIS software and in flood damage analysis (which is already a multidisciplinary field). Great effort is necessary in order to correctly evaluate flood damages, and the updating and the improvement of the evaluation over time become a difficult task. The automation of this process should bring great advance in flood management studies over time, especially for public utilities. This study has two specific objectives: (1) show the entire process of automation of the second and third steps of flood damage evaluations; and (2) analyse the induced potential gains in terms of time and expertise needed in the analysis. A programming language is used within GIS software in order to automate hazard and vulnerability data combination and potential damages calculation. We discuss the overall process of flood damage evaluation. The main result of this study is a computational tool which allows significant operational gains on flood loss analyses. We quantify these gains by means of a hypothetical example. The tool significantly reduces the time of analysis and the needs for expertise. An indirect gain is that sensitivity and cost-benefit analyses can be more easily realized.

Unlocking the Full Potential of Earth Observation During the 2015 Texas Flood Disaster

NASA Technical Reports Server (NTRS)

Schumann, G. J-P.; Frye, S.; Wells, G.; Adler, R.; Brakenridge, R.; Bolten, J.; Murray, J.; Slayback, D.; Policelli, F.; Kirschbaum, D.;

Unlocking the full potential of Earth observation during the 2015 Texas flood disaster

NASA Astrophysics Data System (ADS)

Schumann, G. J.-P.; Frye, S.; Wells, G.; Adler, R.; Brakenridge, R.; Bolten, J.; Murray, J.; Slayback, D.; Policelli, F.; Kirschbaum, D.; Wu, H.; Cappelaere, P.; Howard, T.; Flamig, Z.; Clark, R.; Stough, T.; Chini, M.; Matgen, P.; Green, D.; Jones, B.

2016-05-01

Intense rainfall during late April and early May 2015 in Texas and Oklahoma led to widespread and sustained flooding in several river basins. Texas state agencies relevant to emergency response were activated when severe weather then ensued for 6 weeks from 8 May until 19 June following Tropical Storm Bill. An international team of scientists and flood response experts assembled and collaborated with decision-making authorities for user-driven high-resolution satellite acquisitions over the most critical areas; while experimental automated flood mapping techniques provided daily ongoing monitoring. This allowed mapping of flood inundation from an unprecedented number of spaceborne and airborne images. In fact, a total of 27,174 images have been ingested to the USGS Hazards Data Distribution System (HDDS) Explorer, except for the SAR images used. Based on the Texas flood use case, we describe the success of this effort as well as the limitations in fulfilling the needs of the decision-makers, and reflect upon these. In order to unlock the full potential for Earth observation data in flood disaster response, we suggest in a call for action (i) stronger collaboration from the onset between agencies, product developers, and decision-makers; (ii) quantification of uncertainties when combining data from different sources in order to augment information content; (iii) include a default role for the end-user in satellite acquisition planning; and (iv) proactive assimilation of methodologies and tools into the mandated agencies.

What can'(t) we do with global flood risk models?

NASA Astrophysics Data System (ADS)

Ward, P.; Jongman, B.; Salamon, P.; Simpson, A.; Bates, P. D.; de Groeve, T.; Muis, S.; Coughlan, E.; Rudari, R.; Trigg, M. A.; Winsemius, H.

2015-12-01

Global flood risk models are now a reality. Initially, their development was driven by a demand from users for first-order global assessments to identify risk hotspots. Relentless upward trends in flood damage over the last decade have enhanced interest in such assessments. The adoption of the Sendai Framework for Disaster Risk Reduction and the Warsaw International Mechanism for Loss and Damage Associated with Climate Change Impacts have made these efforts even more essential. As a result, global flood risk models are being used more and more in practice, by an increasingly large number of practitioners and decision-makers. However, they clearly have their limits compared to local models. To address these issues, a team of scientists and practitioners recently came together at the Global Flood Partnership meeting to critically assess the question 'What can('t) we do with global flood risk models?'. The results of this dialogue (Ward et al., 2013) will be presented, opening a discussion on similar broader initiatives at the science-policy interface in other natural hazards. In this contribution, examples are provided of successful applications of global flood risk models in practice (for example together with the World Bank, Red Cross, and UNISDR), and limitations and gaps between user 'wish-lists' and model capabilities are discussed. Finally, a research agenda is presented for addressing these limitations and reducing the gaps. Ward, P.J. et al., 2015. Nature Climate Change, doi:10.1038/nclimate2742.

Use of geostatistic techniques to describe a reservoir to be submitted into a secondary recovery process field case: {open_quotes}Eocene B-Inferior/VLG-3659, Ceuta, Venezuela{close_quotes}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hernandez, T.; Poquioma, W.

1997-08-01

This study presents the results of an integrated reservoir study of the Eocene B-Inferior/VLG-3659, Area 7, Ceuta filed. This field located in the Maracaibo Lake in the western side of Venezuela. The objective was to evaluating the feasibility to implement a secondary recovery project by means of water flooding. Core information was used for this study (194 ft), PVT analysis, RFI, build-up and statistic`s pressure analysis, modem logs and production history data. Using geostatistical techniques (Kriging) it was defined a low uncertainty geological model that was validated by means of a black oil simulator (Eclipse). The results showed a goodmore » comparison of historical pressure of the reservoir against those obtained from the model, without the need of {open_quotes}history matching{close_quotes}. It means without modifying neither the initial rock properties nor reservoir fluids. The results of this study recommended drilling in two new locations, also the reactivation of four producing wells and water flooding under peripherical array by means of four injection wells, with the recovery of an additional 30.2 MMSTB. The economical evaluation shows an internal return rate of 31.4%.« less

Comparing flood loss models of different complexity

NASA Astrophysics Data System (ADS)

Schröter, Kai; Kreibich, Heidi; Vogel, Kristin; Riggelsen, Carsten; Scherbaum, Frank; Merz, Bruno

2013-04-01

Any deliberation on flood risk requires the consideration of potential flood losses. In particular, reliable flood loss models are needed to evaluate cost-effectiveness of mitigation measures, to assess vulnerability, for comparative risk analysis and financial appraisal during and after floods. In recent years, considerable improvements have been made both concerning the data basis and the methodological approaches used for the development of flood loss models. Despite of that, flood loss models remain an important source of uncertainty. Likewise the temporal and spatial transferability of flood loss models is still limited. This contribution investigates the predictive capability of different flood loss models in a split sample cross regional validation approach. For this purpose, flood loss models of different complexity, i.e. based on different numbers of explaining variables, are learned from a set of damage records that was obtained from a survey after the Elbe flood in 2002. The validation of model predictions is carried out for different flood events in the Elbe and Danube river basins in 2002, 2005 and 2006 for which damage records are available from surveys after the flood events. The models investigated are a stage-damage model, the rule based model FLEMOps+r as well as novel model approaches which are derived using data mining techniques of regression trees and Bayesian networks. The Bayesian network approach to flood loss modelling provides attractive additional information concerning the probability distribution of both model predictions and explaining variables.

A new approach for computing a flood vulnerability index using cluster analysis

NASA Astrophysics Data System (ADS)

Fernandez, Paulo; Mourato, Sandra; Moreira, Madalena; Pereira, Luísa

2016-08-01

A Flood Vulnerability Index (FloodVI) was developed using Principal Component Analysis (PCA) and a new aggregation method based on Cluster Analysis (CA). PCA simplifies a large number of variables into a few uncorrelated factors representing the social, economic, physical and environmental dimensions of vulnerability. CA groups areas that have the same characteristics in terms of vulnerability into vulnerability classes. The grouping of the areas determines their classification contrary to other aggregation methods in which the areas' classification determines their grouping. While other aggregation methods distribute the areas into classes, in an artificial manner, by imposing a certain probability for an area to belong to a certain class, as determined by the assumption that the aggregation measure used is normally distributed, CA does not constrain the distribution of the areas by the classes. FloodVI was designed at the neighbourhood level and was applied to the Portuguese municipality of Vila Nova de Gaia where several flood events have taken place in the recent past. The FloodVI sensitivity was assessed using three different aggregation methods: the sum of component scores, the first component score and the weighted sum of component scores. The results highlight the sensitivity of the FloodVI to different aggregation methods. Both sum of component scores and weighted sum of component scores have shown similar results. The first component score aggregation method classifies almost all areas as having medium vulnerability and finally the results obtained using the CA show a distinct differentiation of the vulnerability where hot spots can be clearly identified. The information provided by records of previous flood events corroborate the results obtained with CA, because the inundated areas with greater damages are those that are identified as high and very high vulnerability areas by CA. This supports the fact that CA provides a reliable FloodVI.

Regression equations for estimating flood flows for the 2-, 10-, 25-, 50-, 100-, and 500-Year recurrence intervals in Connecticut

USGS Publications Warehouse

Ahearn, Elizabeth A.

2004-01-01

Multiple linear-regression equations were developed to estimate the magnitudes of floods in Connecticut for recurrence intervals ranging from 2 to 500 years. The equations can be used for nonurban, unregulated stream sites in Connecticut with drainage areas ranging from about 2 to 715 square miles. Flood-frequency data and hydrologic characteristics from 70 streamflow-gaging stations and the upstream drainage basins were used to develop the equations. The hydrologic characteristics?drainage area, mean basin elevation, and 24-hour rainfall?are used in the equations to estimate the magnitude of floods. Average standard errors of prediction for the equations are 31.8, 32.7, 34.4, 35.9, 37.6 and 45.0 percent for the 2-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals, respectively. Simplified equations using only one hydrologic characteristic?drainage area?also were developed. The regression analysis is based on generalized least-squares regression techniques. Observed flows (log-Pearson Type III analysis of the annual maximum flows) from five streamflow-gaging stations in urban basins in Connecticut were compared to flows estimated from national three-parameter and seven-parameter urban regression equations. The comparison shows that the three- and seven- parameter equations used in conjunction with the new statewide equations generally provide reasonable estimates of flood flows for urban sites in Connecticut, although a national urban flood-frequency study indicated that the three-parameter equations significantly underestimated flood flows in many regions of the country. Verification of the accuracy of the three-parameter or seven-parameter national regression equations using new data from Connecticut stations was beyond the scope of this study. A technique for calculating flood flows at streamflow-gaging stations using a weighted average also is described. Two estimates of flood flows?one estimate based on the log-Pearson Type III analyses of the annual maximum flows at the gaging station, and the other estimate from the regression equation?are weighted together based on the years of record at the gaging station and the equivalent years of record value determined from the regression. Weighted averages of flood flows for the 2-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals are tabulated for the 70 streamflow-gaging stations used in the regression analysis. Generally, weighted averages give the most accurate estimate of flood flows at gaging stations. An evaluation of the Connecticut's streamflow-gaging network was performed to determine whether the spatial coverage and range of geographic and hydrologic conditions are adequately represented for transferring flood characteristics from gaged to ungaged sites. Fifty-one of 54 stations in the current (2004) network support one or more flood needs of federal, state, and local agencies. Twenty-five of 54 stations in the current network are considered high-priority stations by the U.S. Geological Survey because of their contribution to the longterm understanding of floods, and their application for regionalflood analysis. Enhancements to the network to improve overall effectiveness for regionalization can be made by increasing the spatial coverage of gaging stations, establishing stations in regions of the state that are not well-represented, and adding stations in basins with drainage area sizes not represented. Additionally, the usefulness of the network for characterizing floods can be maintained and improved by continuing operation at the current stations because flood flows can be more accurately estimated at stations with continuous, long-term record.

Earth Observations taken by Expedition 26 Crewmember

NASA Image and Video Library

2011-01-13

ISS026-E-017421 (13 Jan. 2011) --- Photographed by an Expedition 26 crew member on the International Space Station, this detailed photograph illustrates flooding in suburbs of the Brisbane, Australia metropolitan region. The Brisbane area experienced catastrophic flooding following unusually heavy rainfall on Jan. 10, 2011. With surficial soils already saturated from previous rainfall events, eastward-draining surface flow caused the Brisbane River to flood—inundating an estimated 20,000 homes in suburbs of the capital city of Queensland. Other cities in Queensland have also experienced damaging floods during previous heavy rainfall events this year. The image highlights several suburbs along the Brisbane River in the southern part of the Brisbane metropolitan area. The light-colored rooftops of residences and other structures contrast sharply with green vegetation and brown, sediment laden floodwaters. Most visible low-lying areas are inundated by floodwater, perhaps the most striking being Rocklea at upper left. The suburb of Yeronga (lower left) also has evident regions of flooding, as does a park and golf course located along a bend in the Brisbane River to the south of St. Lucia (center). Flooding becomes less apparent near the higher elevations of Mt. Coot-Tha at right.

Estimation of flood-frequency characteristics of small urban streams in North Carolina

USGS Publications Warehouse

Robbins, J.C.; Pope, B.F.

1996-01-01

A statewide study was conducted to develop methods for estimating the magnitude and frequency of floods of small urban streams in North Carolina. This type of information is critical in the design of bridges, culverts and water-control structures, establishment of flood-insurance rates and flood-plain regulation, and for other uses by urban planners and engineers. Concurrent records of rainfall and runoff data collected in small urban basins were used to calibrate rainfall-runoff models. Historic rain- fall records were used with the calibrated models to synthesize a long- term record of annual peak discharges. The synthesized record of annual peak discharges were used in a statistical analysis to determine flood- frequency distributions. These frequency distributions were used with distributions from previous investigations to develop a database for 32 small urban basins in the Blue Ridge-Piedmont, Sand Hills, and Coastal Plain hydrologic areas. The study basins ranged in size from 0.04 to 41.0 square miles. Data describing the size and shape of the basin, level of urban development, and climate and rural flood charac- teristics also were included in the database. Estimation equations were developed by relating flood-frequency char- acteristics to basin characteristics in a generalized least-squares regression analysis. The most significant basin characteristics are drainage area, impervious area, and rural flood discharge. The model error and prediction errors for the estimating equations were less than those for the national flood-frequency equations previously reported. Resulting equations, which have prediction errors generally less than 40 percent, can be used to estimate flood-peak discharges for 2-, 5-, 10-, 25-, 50-, and 100-year recurrence intervals for small urban basins across the State assuming negligible, sustainable, in- channel detention or basin storage.

Assessment of flood susceptible areas using spatially explicit, probabilistic multi-criteria decision analysis

NASA Astrophysics Data System (ADS)

Tang, Zhongqian; Zhang, Hua; Yi, Shanzhen; Xiao, Yangfan

2018-03-01

GIS-based multi-criteria decision analysis (MCDA) is increasingly used to support flood risk assessment. However, conventional GIS-MCDA methods fail to adequately represent spatial variability and are accompanied with considerable uncertainty. It is, thus, important to incorporate spatial variability and uncertainty into GIS-based decision analysis procedures. This research develops a spatially explicit, probabilistic GIS-MCDA approach for the delineation of potentially flood susceptible areas. The approach integrates the probabilistic and the local ordered weighted averaging (OWA) methods via Monte Carlo simulation, to take into account the uncertainty related to criteria weights, spatial heterogeneity of preferences and the risk attitude of the analyst. The approach is applied to a pilot study for the Gucheng County, central China, heavily affected by the hazardous 2012 flood. A GIS database of six geomorphological and hydrometeorological factors for the evaluation of susceptibility was created. Moreover, uncertainty and sensitivity analysis were performed to investigate the robustness of the model. The results indicate that the ensemble method improves the robustness of the model outcomes with respect to variation in criteria weights and identifies which criteria weights are most responsible for the variability of model outcomes. Therefore, the proposed approach is an improvement over the conventional deterministic method and can provides a more rational, objective and unbiased tool for flood susceptibility evaluation.

Using LiDAR datasets to improve HSPF water quality modeling in the Red River of the North Basin

NASA Astrophysics Data System (ADS)

Burke, M. P.; Foreman, C. S.

2013-12-01

The Red River of the North Basin (RRB), located in the lakebed of ancient glacial Lake Agassiz, comprises one of the flattest landscapes in North America. The topography of the basin, coupled with the Red River's direction of flow from south to north results in a system that is highly susceptible to flooding. The magnitude and frequency of flood events in the RRB has prompted several multijurisdictional projects and mitigation efforts. In response to the devastating 1997 flood, an International Joint Commission sponsored task force established the need for accurate elevation data to help improve flood forecasting and better understand risks. This led to the International Water Institute's Red River Basin Mapping Initiative, and the acquisition LiDAR Data for the entire US portion of the RRB. The resulting 1 meter bare earth digital elevation models have been used to improve hydraulic and hydrologic modeling within the RRB, with focus on flood prediction and mitigation. More recently, these LiDAR datasets have been incorporated into Hydrological Simulation Program-FORTRAN (HSPF) model applications to improve water quality predictions in the MN portion of the RRB. RESPEC is currently building HSPF model applications for five of MN's 8-digit HUC watersheds draining to the Red River, including: the Red Lake River, Clearwater River, Sandhill River, Two Rivers, and Tamarac River watersheds. This work is being conducted for the Minnesota Pollution Control Agency (MPCA) as part of MN's statewide watershed approach to restoring and protecting water. The HSPF model applications simulate hydrology (discharge, stage), as well as a number of water quality constituents (sediment, temperature, organic and inorganic nitrogen, total ammonia, organic and inorganic phosphorus, dissolved oxygen and biochemical oxygen demand, and algae) continuously for the period 1995-2009 and are formulated to provide predictions at points of interest within the watersheds, such as observation gages, management boundaries, compliance points, and impaired water body endpoints. Incorporation of the LiDAR datasets has been critical to representing the topographic characteristics that impact hydrologic and water quality processes in the extremely flat, heavily drained sub-basins of the RRB. Beyond providing more detailed elevation and slope measurements, the high resolution LiDAR datasets have helped to identify drainage alterations due to agricultural practices, as well as improve representation of channel geometry. Additionally, when available, LiDAR based hydraulic models completed as part of the RRB flood mitigation efforts, are incorporated to further improve flow routing. The MPCA will ultimately use these HSPF models to aid in Total Maximum Daily Load (TMDL) development, permit development/compliance, analysis of Best Management Practice (BMP) implementation scenarios, and other watershed planning and management objectives. LiDAR datasets are an essential component of the water quality models build for the watersheds within the RRB and would greatly benefit water quality modeling efforts in similarly characterized areas.

Hyper-resolution monitoring of urban flooding with social media and crowdsourcing data

NASA Astrophysics Data System (ADS)

Wang, Ruo-Qian; Mao, Huina; Wang, Yuan; Rae, Chris; Shaw, Wesley

2018-02-01

Hyper-resolution datasets for urban flooding are rare. This problem prevents detailed flooding risk analysis, urban flooding control, and the validation of hyper-resolution numerical models. We employed social media and crowdsourcing data to address this issue. Natural Language Processing and Computer Vision techniques are applied to the data collected from Twitter and MyCoast (a crowdsourcing app). We found these big data based flood monitoring approaches can complement the existing means of flood data collection. The extracted information is validated against precipitation data and road closure reports to examine the data quality. The two data collection approaches are compared and the two data mining methods are discussed. A series of suggestions is given to improve the data collection strategy.

Using a Geographic Information System to Assess the Risk of Hurricane Hazards on the Maya Civilization

NASA Astrophysics Data System (ADS)

Weigel, A. M.; Griffin, R.; Sever, T.

2014-12-01

The extent of the Maya civilization spanned across portions of modern day Mexico, Belize, Guatemala, El Salvador and Honduras. Paleoclimatic studies suggest this region has been affected by strong hurricanes for the past six thousand years, reinforced by archeological evidence from Mayan records indicating they experienced strong storms. It is theorized hurricanes aided in the collapse of the Maya, damaging building structures, agriculture, and ceasing industry activities. Today, this region is known for its active tropical climatology, being hit by numerous strong storms including Hurricane Dean, Iris, Keith, and Mitch. This research uses a geographic information system (GIS) to model hurricane hazards, and assess the risk posed on the Maya civilization. GIS has the ability to handle various layer components making it optimal for combining parameters necessary for assessing the risk of experiencing hurricane related hazards. For this analysis, high winds, storm surge flooding, non-storm surge related flooding, and rainfall triggered landslides were selected as the primary hurricane hazards. Data sets used in this analysis include the National Climatic Data Center International Best Track Archive for Climate Stewardships (IBTrACS) hurricane tracks, Shuttle Radar Topography Mission Digital Elevation Model, WorldClim monthly accumulated precipitation, USGS HydroSHEDS river locations, Harmonized World Soil Database soil types, and known Maya site locations from the Electronic Atlas of Ancient Maya Sites. ArcGIS and ENVI software were utilized to process data and model hurricane hazards. To assess locations at risk of experiencing high winds, a model was created using ArcGIS Model Builder to map each storm's temporal wind profile, and adapted to simulate forward storm velocity, and storm frequency. Modeled results were then combined with physical land characteristics, meteorological, and hydrologic data to identify areas likely affected. Certain areas along the eastern edge of the Yucatan peninsula were found to be more prone to experiencing wind and flood related hurricane hazards. Novel methodologies developed from this analysis can be adapted for further hurricane risk assessment on archeological sites.

Quantitative Proteomics Reveals the Flooding-Tolerance Mechanism in Mutant and Abscisic Acid-Treated Soybean.

PubMed

Yin, Xiaojian; Nishimura, Minoru; Hajika, Makita; Komatsu, Setsuko

2016-06-03

Flooding negatively affects the growth of soybean, and several flooding-specific stress responses have been identified; however, the mechanisms underlying flooding tolerance in soybean remain unclear. To explore the initial flooding tolerance mechanisms in soybean, flooding-tolerant mutant and abscisic acid (ABA)-treated plants were analyzed. In the mutant and ABA-treated soybeans, 146 proteins were commonly changed at the initial flooding stress. Among the identified proteins, protein synthesis-related proteins, including nascent polypeptide-associated complex and chaperonin 20, and RNA regulation-related proteins were increased in abundance both at protein and mRNA expression. However, these proteins identified at the initial flooding stress were not significantly changed during survival stages under continuous flooding. Cluster analysis indicated that glycolysis- and cell wall-related proteins, such as enolase and polygalacturonase inhibiting protein, were increased in abundance during survival stages. Furthermore, lignification of root tissue was improved even under flooding stress. Taken together, these results suggest that protein synthesis- and RNA regulation-related proteins play a key role in triggering tolerance to the initial flooding stress in soybean. Furthermore, the integrity of cell wall and balance of glycolysis might be important factors for promoting tolerance of soybean root to flooding stress during survival stages.

Dependence of flood risk perceptions on socioeconomic and objective risk factors

NASA Astrophysics Data System (ADS)

Botzen, W. J. W.; Aerts, J. C. J. H.; van den Bergh, J. C. J. M.

2009-10-01

This study examines flood risk perceptions of individuals in the Netherlands using a survey of approximately 1000 homeowners. Perceptions of a range of aspects of flood risk are elicited. Various statistical models are used to estimate the influence of socioeconomic and geographical characteristics, personal experience with flooding, knowledge of flood threats, and individual risk attitudes on shaping risk belief. The study shows that in general, perceptions of flood risk are low. An analysis of the factors determining risk perceptions provides four main insights relevant for policy makers and insurers. First, differences in expected risk are consistently related to actual risk levels, since individuals in the vicinity of a main river and low-lying areas generally have elevated risk perceptions. Second, individuals in areas unprotected by dikes tend to underestimate their risk of flooding. Third, individuals with little knowledge of the causes of flood events have lower perceptions of flood risk. Fourth, there is some evidence that older and more highly educated individuals have a lower flood risk perception. The findings indicate that increasing knowledge of citizens about the causes of flooding may increase flood risk awareness. It is especially important to target individuals who live in areas unprotected by dike infrastructure, since they tend to be unaware of or ignore the high risk exposure faced.

Detecting seasonal flood changes in the Upper Danube River basin

NASA Astrophysics Data System (ADS)

Kohnová, Silvia; Jeneiová, Katarína; Parajka, Juraj; Hall, Julia; Marková, Romana

2017-04-01

Due to a number of large-scale floods observed worldwide in recent years, the analysis of changes in long-term hydrological time series is becoming increasingly important. This study focuses on the Upper Danube region, which was struck by many flood events in the past decade. The flood seasonality of the study region, defined as the area of Germany, the Czech Republic, Switzerland, Austria and Slovakia, is examined to interpret the dominant flood processes. A spatial assessment of the seasonality indices of the annual maximum discharges and the seasonal discharges (derived from daily average discharges) was conducted for 117 gauging stations. Hot spots for potential changes in the mean dates of occurrence of the discharges were identified, and the results were linked with derived spatial characteristics for the catchments. The first results of the study of the seasonal discharges revealed that the variability of occurrence of summer floods is higher than winter floods in lowlands of the upper Danube catchment. In high Alpine catchments the winter floods variability of occurrence is the same or higher than for the summer floods. The summer season floods tend to appear for all catchment sizes in the same time period. With increased magnitude of floods in the summer season, the variability of occurrence of the floods is higher.

Rehabilitation and Flood Management Planning in a Steep, Boulder-Bedded Stream

NASA Astrophysics Data System (ADS)

Caruso, Brian S.; Downs, Peter W.

2007-08-01

This study demonstrates the integration of rehabilitation and flood management planning in a steep, boulder-bedded stream in a coastal urban catchment on the South Island of New Zealand. The Water of Leith, the primary stream flowing through the city of Dunedin, is used as a case study. The catchment is steep, with a short time of concentration and rapid hydrologic response, and the lower stream reaches are highly channelized with floodplain encroachment, a high potential for debris flows, significant flood risks, and severely degraded aquatic habitat. Because the objectives for rehabilitation and flood management in urban catchments are often conflicting, a number of types of analyses at both the catchment and the reach scales and careful planning with stakeholder consultation were needed for successful rehabilitation efforts. This included modeling and analysis of catchment hydrology, fluvial geomorphologic assessment, analysis of water quality and aquatic ecology, hydraulic modeling and flood risk evaluation, detailed feasibility studies, and preliminary design to optimize multiple rehabilitation and flood management objectives. The study showed that all of these analyses were needed for integrated rehabilitation and flood management and that some incremental improvements in stream ecological health, aesthetics, and public recreational opportunities could be achieved in this challenging environment. These methods should be considered in a range of types of stream rehabilitation projects.

Foundations for computer simulation of a low pressure oil flooded single screw air compressor

NASA Astrophysics Data System (ADS)

Bein, T. W.

1981-12-01

The necessary logic to construct a computer model to predict the performance of an oil flooded, single screw air compressor is developed. The geometric variables and relationships used to describe the general single screw mechanism are developed. The governing equations to describe the processes are developed from their primary relationships. The assumptions used in the development are also defined and justified. The computer model predicts the internal pressure, temperature, and flowrates through the leakage paths throughout the compression cycle of the single screw compressor. The model uses empirical external values as the basis for the internal predictions. The computer values are compared to the empirical values, and conclusions are drawn based on the results. Recommendations are made for future efforts to improve the computer model and to verify some of the conclusions that are drawn.

Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes.

PubMed

Lieberman-Cribbin, Wil; Liu, Bian; Schneider, Samantha; Schwartz, Rebecca; Taioli, Emanuela

2017-01-01

Hurricane Sandy caused extensive physical and economic damage; the long-term mental health consequences are unknown. Flooding is a central component of hurricane exposure, influencing mental health through multiple pathways that unfold over months after flooding recedes. Here we assess the concordance in self-reported and Federal Emergency Management (FEMA) flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder (PTSD). Self-reported flood data and mental health symptoms were obtained through validated questionnaires from New York City and Long Island residents (N = 1231) following Sandy. Self-reported flood data was compared to FEMA data obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. Multivariable logistic regressions were performed to determine the relationship between flooding exposure and mental health outcomes. There were significant discrepancies between self-reported and FEMA flood exposure data. Self-reported dichotomous flooding was positively associated with anxiety (ORadj: 1.5 [95% CI: 1.1-1.9]), depression (ORadj: 1.7 [1.3-2.2]), and PTSD (ORadj: 2.5 [1.8-3.4]), while self-reported continuous flooding was associated with depression (ORadj: 1.1 [1.01-1.12]) and PTSD (ORadj: 1.2 [1.1-1.2]). Models with FEMA dichotomous flooding (ORadj: 2.1 [1.5-2.8]) or FEMA continuous flooding (ORadj: 1.1 [1.1-1.2]) were only significantly associated with PTSD. Associations between mental health and flooding vary according to type of flood exposure measure utilized. Future hurricane preparedness and recovery efforts must integrate micro and macro-level flood exposures in order to accurately determine flood exposure risk during storms and realize the long-term importance of flooding on these three mental health symptoms.

Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes

PubMed Central

Liu, Bian; Schneider, Samantha; Schwartz, Rebecca; Taioli, Emanuela

2017-01-01

Hurricane Sandy caused extensive physical and economic damage; the long-term mental health consequences are unknown. Flooding is a central component of hurricane exposure, influencing mental health through multiple pathways that unfold over months after flooding recedes. Here we assess the concordance in self-reported and Federal Emergency Management (FEMA) flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder (PTSD). Self-reported flood data and mental health symptoms were obtained through validated questionnaires from New York City and Long Island residents (N = 1231) following Sandy. Self-reported flood data was compared to FEMA data obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. Multivariable logistic regressions were performed to determine the relationship between flooding exposure and mental health outcomes. There were significant discrepancies between self-reported and FEMA flood exposure data. Self-reported dichotomous flooding was positively associated with anxiety (ORadj: 1.5 [95% CI: 1.1–1.9]), depression (ORadj: 1.7 [1.3–2.2]), and PTSD (ORadj: 2.5 [1.8–3.4]), while self-reported continuous flooding was associated with depression (ORadj: 1.1 [1.01–1.12]) and PTSD (ORadj: 1.2 [1.1–1.2]). Models with FEMA dichotomous flooding (ORadj: 2.1 [1.5–2.8]) or FEMA continuous flooding (ORadj: 1.1 [1.1–1.2]) were only significantly associated with PTSD. Associations between mental health and flooding vary according to type of flood exposure measure utilized. Future hurricane preparedness and recovery efforts must integrate micro and macro-level flood exposures in order to accurately determine flood exposure risk during storms and realize the long-term importance of flooding on these three mental health symptoms. PMID:28129410

Radar Mosaic of Africa

NASA Technical Reports Server (NTRS)

1999-01-01

This is an image of equatorial Africa, centered on the equator at longitude 15degrees east. This image is a mosaic of almost 4,000 separate images obtained in 1996 by the L-band imaging radar onboard the Japanese Earth Resources Satellite. Using radar to penetrate the persistent clouds prevalent in tropical forests, the Japanese Earth Resources Satellite was able for the first time to image at high resolution this continental scale region during single flooding seasons. The area shown covers about 7.4 million square kilometers (2.8 million square miles) of land surface, spans more than 5,000 kilometers(3,100 miles) east and west and some 2,000 kilometers (1,240 miles) north and south. North is up in this image. At the full resolution of the mosaic (100 meters or 330 feet), this image is more than 500 megabytes in size, and was processed from imagery totaling more than 60 gigabytes.

Central Africa was imaged twice in 1996, once between January and March, which is the major low-flood season in the Congo Basin, and once between October and November, which is the major high-flood season in the Congo Basin. The red color corresponds to the data from the low-flood season, the green to the high-flood season, and the blue to the 'texture' of the low-flood data. The forests appear green as a result, the flooded and palm forests, as well as urban areas, appear yellow, the ocean and lakes appear black, and savanna areas appear blue, black or green, depending on the savanna type, surface topography and other factors. The areas of the image that are black and white were mapped only between January and March 1996. In these areas, the black areas are savanna or open water, the gray are forests, and the white areas are flooded forests or urban areas. The Congo River dominates the middle of the image, where the nearby forests that are periodically flooded by the Congo and its tributaries stand out as yellow. The Nile River flows north from Lake Victoria in the middle right of the color portion of the mosaic.

This image is one of the products resulting from the Global Rain Forest Mapping project, a joint project between the National Space Development Agency of Japan, the Space Applications Institute of the Joint Research Centre of the European Commission, NASA's Jet Propulsion Laboratory and an international team of scientists. The goal of the Global Rain Forest Mapping mission is to map with the Japanese Earth Resources Satellite the world's tropical rain forests. The Japanese satellite was launched in 1992 by the National Space Development Agency of Japan and the Japanese Ministry of International Trade and Industry, with support from the Remote Sensing Technology Center of Japan.

Flood frequency analysis and generation of flood hazard indicator maps in a semi-arid environment, case of Ourika watershed (western High Atlas, Morocco)

NASA Astrophysics Data System (ADS)

El Alaoui El Fels, Abdelhafid; Alaa, Noureddine; Bachnou, Ali; Rachidi, Said

2018-05-01

The development of the statistical models and flood risk modeling approaches have seen remarkable improvements in their productivities. Their application in arid and semi-arid regions, particularly in developing countries, can be extremely useful for better assessment and planning of flood risk in order to reduce the catastrophic impacts of this phenomenon. This study focuses on the Setti Fadma region (Ourika basin, Morocco) which is potentially threatened by floods and is subject to climatic and anthropogenic forcing. The study is based on two main axes: (i) the extreme flow frequency analysis, using 12 probability laws adjusted by Maximum Likelihood method and (ii) the generation of the flood risk indicator maps are based on the solution proposed by the Nays2DFlood solver of the Hydrodynamic model of two-dimensional Saint-Venant equations. The study is used as a spatial high-resolution digital model (Lidar) in order to get the nearest hydrological simulation of the reality. The results showed that the GEV is the most appropriate law of the extreme flows estimation for different return periods. Taking into consideration the mapping of 100-year flood area, the study revealed that the fluvial overflows extent towards the banks of Ourika and consequently, affects some living areas, cultivated fields and the roads that connects the valley to the city of Marrakech. The aim of this study is to propose new technics of the flood risk management allowing a better planning of the flooded areas.

75 FR 78613 - Changes in Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-16

... Flood Disaster Protection Act of 1973, 42 U.S.C. 4105, and are in accordance with the National Flood Insurance Act of 1968, 42 U.S.C. 4001 et seq., and with 44 CFR part 65. For rating purposes, the currently... within the scope of the Regulatory Flexibility Act, 5 U.S.C. 601- 612, a regulatory flexibility analysis...

Toward a New Conceptual Framework for Teaching about Flood Risk in Introductory Geoscience Courses

ERIC Educational Resources Information Center

Lutz, Tim

2011-01-01

An analysis of physical geology textbooks used in introductory courses shows that there is a systematic lack of clarity regarding flood risk. Some problems originate from confusion relating to statistical terms such as "100-year flood" and "100-year floodplain." However, the main problem is conceptual: statistics such as return…

Measuring flood footprint of a regional economy - A case study for the UK flooding

NASA Astrophysics Data System (ADS)

Guan, D.

2013-12-01

Analysis of the urban economy and society is central to understanding the broad impacts of flooding and to identify cost-effective adaptation and mitigation measures. Assessments of the flooding impacts on cities have traditionally focused on the initial impact on people and assets. These initial estimates (so-called ';direct damage') are useful both in understanding the immediate implications of damage, and in marshalling the pools of capital and supplies required for re-building after an event. Since different economies as well as societies are coupled, especially under the current economic crisis, any small-scale damage may be multiplied and cascaded throughout wider economic systems and social networks. The direct and indirect damage is currently not evaluated well and could be captured by quantification of what we call the flood footprint. Flooding in one location can impact the whole UK economy. Neglecting these knock-on costs (i.e. the true footprint of the flood) means we might be ignoring the economic benefits and beneficiaries of flood risk management interventions. In 2007, for example, floods cost the economy about £3.2 bn directly, but the wider effect might actually add another 50% to 250% to that. Flood footprint is a measure of the exclusive total socioeconomic impact that is directly and indirectly caused by a flood event to the flooding region and wider economic systems and social networks. We adopt the UK 2012 flooding. An input-output basic dynamic inequalities (BDI) model is used to assess the impact of the floodings on the level of a Yorkshire economy, accounting for interactions between industries through demand and supply of intermediate consumption goods with a circular flow. After the disaster the economy will be unbalanced. The recovery process finishes when the economy is completely balance, i.e., when labour production capacity equals demands and production and all the variables reach pre-disaster levels. The analysis is carried out focusing on 42 sectors. Most regional data have been produced from the Multisectoral Dynamic Model of the UK economy. The flooding caused a 3.56% direct damage in the Yorkshire economy, while the indirect accounted for 14.58%.Utilities and transportation where the sectors that suffered the greatest direct impact. This impact indirectly transferred through business and supply chain to services, construction and primary industries.

Analysis of alternative modifications for reducing backwater at the Interstate Highway 10 crossing of the Pearl River near Slidell, Louisiana

USGS Publications Warehouse

Wiche, Gregg J.; Gilbert, J.J.; Froehlich, David C.; Lee, Jonathan K.

1988-01-01

In April 1979 and April 1980, major flooding along the lower Pearl River caused extensive damage to homes located on the flood plain in the Slidell, Louisiana, area. In response to questions about causes of these floods and means of mitigating future floods, the U.S. Geological Survey, in cooperation with the Louisiana Department of Transportation and Development, Office of Highways, and the U.S. Department of Transportation, Federal Highway Administration, used a two-dimensional finite-element surface-water flow-modeling system to study the effect of four alternative modifications for improving the hydraulic characteristics of the Interstate Highway 10 crossing of the flood plain near Slidell. The analysis used the model's capability to simulate changes in flood-plain topography, flood-plain vegetative cover, and highway-embankment geometry. Compared with the existing highway crossing, the four alternative modifications reduce backwater and average velocities through bridge openings for a flood of the magnitude of the 1980 flood. The four alternatives also eliminate roadway overtopping during such a flood. For the four modifications, maximum backwater on the west side of the flood plain ranges from 0.3 to 1.1 feet and on the east side from 0.3 to 0.7 foot. Results of the alternative-model simulations show that backwater is greater on the west side of the flood plain than on the east side, but upstream from Interstate Highway 10 backwater decreases more rapidly in the upstream direction on the west side of the flood plain than on the east side. Downstream from Interstate Highway 10, modeling of the four alternatives indicates that backwater and drawdown still occur on the east and west sides of the flood plain, respectively, but are less than the values computed for the April 1980 flood with Interstate Highway 10 in place. In addition to other highway-crossing modifications, alternatives 2 and 3 include simulation of a new 2,000-foot bridge opening, and ,alternative 4 includes simulation of a 1,000-foot bridge opening. The new bridge conveys 25, 23, and 21 percent of the total computed discharge in alternatives 2, 3, and 4, respectively. The average velocity through the new bridge is 2.0, 1.9, and 3.4 feet per second for alternatives 2, 3, and 4, respectively.

Flood hazards along the Toutle and Cowlitz rivers, Washington, from a hypothetical failure of Castle Lake blockage

USGS Publications Warehouse

Laenen, Antonius; Orzol, L.L.

1987-01-01

A recent evaluation of groundwater and material in the blockage impounding Castle Lake shows that the blockage is potentially unstable against failure from piping due to heave and internal erosion when groundwater levels are seasonally high. There is also a remote possibility that a 6.8 or greater magnitude earthquake could occur in the Castle Lake area when groundwater levels are critically high. If this situation occurs, the debris blockage that confines Castle Lake could breach from successive slope failure with liquefaction of a portion of the blockage. A dam-break computer model was used to simulate discharge through a hypothetical breach in the Castle Lake blockage that could be caused by failure by heave, internal erosion, or liquefaction. Approximately 18,500 acre-ft of stored water would be released from an assumed breach that fully developed to a 1,000-ft width over a 15-minute time period. The resulting flood, incorporating 3.4 x 10 to the 6th power cu yd of the debris blockage, would reach a peak magnitude of 1,500,000 cu ft/s (cubic feet per second). The flood is also assumed to incorporate an additional 137x10 to the 6th power cu yd of saturated debris material from downstream deposits. Flow is considered to be hyperconcentrated with sediment throughout the course of the flood. The hypothetical hyperconcentrated flow is routed downstream, superimposed on normal winter flood flows by use of a one-dimensional unsteady-state numerical streamflow simulation model. From a starting magnitude of 1,500,000 cu ft/s, the peak increases to 2,100,000 cu ft/s at N-1 Dam (12 mi downstream) and attenuates to 1,200,000 cu ft/s at Kid Valley (25 mi downstream) , to 100,000 cu ft/s at Longview and the confluence of the Columbia River (65 mi downstream). From time of breach, the flood peak would take 2.2 hr to reach Toutle, 3.8 hr to reach Castle Rock, and 8.5 hr to reach Longview. Communities of Toutle , Castle Rock, Kelso, and Longview would experience extreme to moderate flooding for this scenario. (Author 's abstract)

Flood risk changes in Northeastern part of Iberian Peninsula: from impact data to flow data

NASA Astrophysics Data System (ADS)

Llasat, Maria-Carmen; Gilabert, Joan; Llasat-Botija, Montserrat; Marcos, Raül; Quintana-Seguí, Pere; Turco, Marco

2014-05-01

The analysis of the temporal evolution of historical floods usually is based on proxy data obtained collecting flooding information from continuous records in municipal, ecclesiastic and private documentary sources. This kind of documentary series usually provide details of the damage caused by the flooding, with the exact date and duration, and in some occasions, some details on the behaviour of the rising water (duration, magnitude, indirect measurements), further details about the precipitation episode that gave rise to it, and the characteristics and dimensions of the riverbeds and the infrastructure associated with the watercourse (dams, bridges, mills, dykes). Based on this information, the first step is to estimate the flood impacts and, usually, in order to build flood data series, the event is classified following some criteria (i.e. catastrophic, extraordinary, ordinary). Exceptionally, some events are reconstructed and the maximum flow or level of the inundation is estimated. However, there are not so many studies that compare flow series and flood series obtained from proxy data. The interest of doing it is, not only to check the quality of the information and to compare the trend of both kind of series, but also to identify the role of other variables and their potential change in the flood risk evolution. Besides this, a potential relationship between the flood classification criteria and the flood frequency distribution obtained from flow data could be done. The contribution departs from the INUNGAMA database that contains 372 flood events recorded in Northeastern of Iberian Peninsula from 1900 to 2010 (Barnolas and Llasat, 2007; Llasat et al, 2013); the PRESSGAMA database that includes more than 15,000 news related to natural hazards and climate change published between 1981 and 2010 and with detailed information for each flood event (Llasat et al, 2009) and the historical flood database with data since the 14th century for the rivers Ter, Llobregat and Segre (Llasat et al, 2005). Daily flow data for the rivers Muga (1971-2013), Ter (1912-2013) and Llobregat (1912-2013) has also been obtained from the Catalan Water Agency. Precipitation and temperature daily data has been provided by Spain-02 (Herrera et al 2012) for the period 1950-2008. First of all, the quality of all the series has been checked and a consistency analysis between them has been done. The correlation between rainfall and flow series has been studied for some specific catchments. Then, trend analysis of different series has been made by applying the Mann-Kendall method and a resampling method (Turco and Llasat, 2011), in order to identify decadal changes. Finally, a flood event has been selected as case study to illustrate the different factors that can be involved. This contribution has been supported by the DRIHM project.

The English national cohort study of flooding and health: cross-sectional analysis of mental health outcomes at year one.

PubMed

Waite, Thomas David; Chaintarli, Katerina; Beck, Charles R; Bone, Angie; Amlôt, Richard; Kovats, Sari; Reacher, Mark; Armstrong, Ben; Leonardi, Giovanni; Rubin, G James; Oliver, Isabel

2017-01-28

In winter 2013/14 there was widespread flooding in England. Previous studies have described an increased prevalence of psychological morbidity six months after flooding. Disruption to essential services may increase morbidity however there have been no studies examining whether those experiencing disruption but not directly flooded are affected. The National Study of Flooding and Health was established in order to investigate the longer-term impact of flooding and related disruptions on mental health and wellbeing. In year one we conducted a cross sectional analysis of people living in neighbourhoods affected by flooding between 1 December 2013 and 31 March 2014. 8761 households were invited to participate. Participants were categorised according to exposure as flooded, disrupted by flooding or unaffected. We used validated instruments to screen for probable psychological morbidity, the Patient Health Questionnaire (PHQ 2), Generalised Anxiety Disorder scale (GAD-2) and Post Traumatic Stress Disorder (PTSD) checklist (PCL-6). We calculated prevalence and odds ratios for each outcome by exposure group relative to unaffected participants, adjusting for confounders. 2126 people (23%) responded. The prevalence of psychological morbidity was elevated amongst flooded participants ([n = 622] depression 20.1%, anxiety 28.3%, PTSD 36.2%) and disrupted participants ([n = 1099] depression 9.6%, anxiety 10.7% PTSD 15.2%). Flooding was associated with higher odds of all outcomes (adjusted odds ratios (aORs), 95% CIs for depression 5.91 (3.91-10.99), anxiety 6.50 (3.77-11.24), PTSD 7.19 (4.33-11.93)). Flooded participants who reported domestic utilities disruption had higher odds of all outcomes than other flooded participants, (aORs, depression 6.19 (3.30-11.59), anxiety 6.64 (3.84-11.48), PTSD 7.27 (4.39-12.03) aORs without such disruption, depression, 3.14 (1.17-8.39), anxiety 3.45 (1.45-8.22), PTSD 2.90 (1.25-6.73)). Increased floodwater depth was significantly associated with higher odds of each outcome. Disruption without flooding was associated with borderline higher odds of anxiety (aOR 1.61 (0.94-2.77)) and higher odds of PTSD 2.06 (1.27-3.35)) compared with unaffected participants. Disruption to health/social care and work/education was also associated with higher odds of psychological morbidity. This study provides an insight into the impact of flooding on mental health, suggesting that the impacts of flooding are large, prolonged and extend beyond just those whose homes are flooded.

Earth Observations taken by the Expedition 27 Crew

NASA Image and Video Library

2011-05-12

ISS027-E-027026 (12 May 2011) --- An Expedition 27 crew member recorded this image aboard the International Space Station as the orbital outpost was passing over the Mississippi River flood waters from 220 miles above. North is toward the bottom of the image, which was captured using a 400-mm lens. This highly impacted area, centered near 36.6 degrees north latitude and 89.5 degrees west longitude, is just east of New Madrid, Mo. (visible in upper right). Levees appear to be intact here, but there is extensive lowland crop flooding.

Review article: A review and critical analysis of the efforts towards urban flood risk management in the Lagos region of Nigeria

NASA Astrophysics Data System (ADS)

Nkwunonwo, U. C.; Whitworth, M.; Baily, B.

2016-02-01

Urban flooding has been and will continue to be a significant problem for many cities across the developed and developing world. Crucial to the amelioration of the effects of these floods is the need to formulate a sound flood management policy, which is driven by knowledge of the frequency and magnitude of impacts of these floods. Within the area of flood research, attempts are being made to gain a better understanding of the causes, impacts, and pattern of urban flooding. According to the United Nations office for disaster reduction (UNISDR), flood risk is conceptualized on the basis of three integral components which are frequently adopted during flood damage estimation. These components are: probability of flood hazard, the level of exposure, and vulnerabilities of elements at risk. Reducing the severity of each of these components is the objective of flood risk management under the UNISDR guideline and idea of "living with floods". On the basis of this framework, the present research reviews flood risk within the Lagos area of Nigeria over the period 1968-2012. During this period, floods have caused harm to millions of people physically, emotionally, and economically. Arguably over this period the efforts of stakeholders to address the challenges appear to have been limited by, amongst other things, a lack of reliable data, a lack of awareness amongst the population affected, and a lack of knowledge of flood risk mitigation. It is the aim of this research to assess the current understanding of flood risk and management in Lagos and to offer recommendations towards future guidance.

Coastal flooding as a parameter in multi-criteria analysis for industrial site selection

NASA Astrophysics Data System (ADS)

Christina, C.; Memos, C.; Diakoulaki, D.

2014-12-01

Natural hazards can trigger major industrial accidents, which apart from affecting industrial installations may cause a series of accidents with serious impacts on human health and the environment far beyond the site boundary. Such accidents, also called Na-Tech (natural - technical) accidents, deserve particular attention since they can cause release of hazardous substances possibly resulting in severe environmental pollution, explosions and/or fires. There are different kinds of natural events or, in general terms, of natural causes of industrial accidents, such as landslides, hurricanes, high winds, tsunamis, lightning, cold/hot temperature, floods, heavy rains etc that have caused accidents. The scope of this paper is to examine the coastal flooding as a parameter in causing an industrial accident, such as the nuclear disaster in Fukushima, Japan, and the critical role of this parameter in industrial site selection. Land use planning is a complex procedure that requires multi-criteria decision analysis involving economic, environmental and social parameters. In this context the parameter of a natural hazard occurrence, such as coastal flooding, for industrial site selection should be set by the decision makers. In this paper it is evaluated the influence that has in the outcome of a multi-criteria decision analysis for industrial spatial planning the parameter of an accident risk triggered by coastal flooding. The latter is analyzed in the context of both sea-and-inland induced flooding.

Identifying Changes of Complex Flood Dynamics with Recurrence Analysis

NASA Astrophysics Data System (ADS)

Wendi, D.; Merz, B.; Marwan, N.

2016-12-01

Temporal changes in flood hazard system are known to be difficult to detect and attribute due to multiple drivers that include complex processes that are non-stationary and highly variable. These drivers, such as human-induced climate change, natural climate variability, implementation of flood defense, river training, or land use change, could impact variably on space-time scales and influence or mask each other. Flood time series may show complex behavior that vary at a range of time scales and may cluster in time. Moreover hydrological time series (i.e. discharge) are often subject to measurement errors, such as rating curve error especially in the case of extremes where observation are actually derived through extrapolation. This study focuses on the application of recurrence based data analysis techniques (recurrence plot) for understanding and quantifying spatio-temporal changes in flood hazard in Germany. The recurrence plot is known as an effective tool to visualize the dynamics of phase space trajectories i.e. constructed from a time series by using an embedding dimension and a time delay, and it is known to be effective in analyzing non-stationary and non-linear time series. Sensitivity of the common measurement errors and noise on recurrence analysis will also be analyzed and evaluated against conventional methods. The emphasis will be on the identification of characteristic recurrence properties that could associate typical dynamic to certain flood events.

Vertical accretion sand proxies of gaged floods along the upper Little Tennessee River, Blue Ridge Mountains, USA

NASA Astrophysics Data System (ADS)

Leigh, David S.

2018-02-01

Understanding environmental hazards presented by river flooding has been enhanced by paleoflood analysis, which uses sedimentary records to document floods beyond historical records. Bottomland overbank deposits (e.g., natural levees, floodbasins, meander scars, low terraces) have the potential as continuous paleoflood archives of flood frequency and magnitude, but they have been under-utilized because of uncertainty about their ability to derive flood magnitude estimates. The purpose of this paper is to provide a case study that illuminates tremendous potential of bottomland overbank sediments as reliable proxies of both flood frequency and magnitude. Methods involve correlation of particle-size measurements of the coarse tail of overbank deposits (> 0.25 mm sand) from three separate sites with historical flood discharge records for the upper Little Tennessee River in the Blue Ridge Mountains of the southeastern United States. Results show that essentially all floods larger than a 20% probability event can be detected by the coarse tail of particle-size distributions, especially if the temporal resolution of sampling is annual or sub-annual. Coarser temporal resolution (1.0 to 2.5 year sample intervals) provides an adequate record of large floods, but is unable to discriminate individual floods separated by only one to three years. Measurements of > 0.25 mm sand that are normalized against a smoothed trend line through the down-column data produce highly significant correlations (R2 values of 0.50 to 0.60 with p-values of 0.004 to < 0.001) between sand peak values and flood peak discharges, indicating that flood magnitude can be reliably estimated. In summary, bottomland overbank deposits can provide excellent continuous records of paleofloods when the following conditions are met: 1) Stable depositional sites should be chosen; 2) Analysis should concentrate on the coarse tails of particle-size distributions; 3) Sampling of sediment intervals should achieve annual or better resolution; 4) Time-series data of particle-size should be detrended to minimize variation from dynamic aspects of fluvial sedimentation that are not related to flood magnitude; and 5) Multiple sites should be chosen to allow for replication of findings.