WorldWideScience

Sample records for flood event impact

  1. Impacts of Floods Events on Food Security

    Science.gov (United States)

    Caporali, E.; Pacetti, T.; Rulli, M. C.

    2017-12-01

    The analysis of the interactions among natural disasters and food security is particularly significant for developing countries where food availability (one of the four pillars of food security together with access, utilization and stability) can be highly jeopardize by extreme events that damage the primary access to food, i.e. the agriculture. The main objective of this study is to analyze the impact of flood events on food security for two disastrous flood events in Bangladesh on 2007 and in Pakistan on 2010, selected here as case studies based on the existing literature related to extreme floods.The adopted methodology integrates remote sensing data, agricultural statistics, and water footprint values in order to (i) evaluating the potentially affected agricultural areas; (ii) converting the affected areas into crop loss; (iii) estimating the associated calories and water footprint losses. In Bangladesh, the estimated lost rice is around 12.5% of the total potential production, which implies a 5.3% calories loss with respect to the total potential energy provided by rice and 4.4% of total WF associated to national food supply. In Pakistan, the results show a crops loss of 19% for sugarcane and 40% for rice, with a related calories loss of 8.5% and a WF loss of 13.5%.The results highlight the countries vulnerability to flood, being both countries strongly dependent on local agricultural production. The 2007 flood event reflected critically upon Bangladeshi food security, almost doubling the existing food deficit. The same happened in Pakistan where an already scarce food supply has been worsened by the 2010 flood.Method results are fully repeatable; whereas, for remote sensed data the sources of data are valid worldwide and the data regarding land use and crops characteristics are strongly site specific, which need to be carefully evaluated.These case studies stress the importance of integrating different analysis approaches to carry out an assessment of the

  2. From theoretical fixed return period events to real flooding impacts: a new approach to set flooding scenarios, thresholds and alerts

    Science.gov (United States)

    Parravicini, Paola; Cislaghi, Matteo; Condemi, Leonardo

    2017-04-01

    ARPA Lombardia is the Environmental Protection Agency of Lombardy, a wide region in the North of Italy. ARPA is in charge of river monitoring either for Civil Protection or water balance purposes. It cooperates with the Civil Protection Agency of Lombardy (RL-PC) in flood forecasting and early warning. The early warning system is based on rainfall and discharge thresholds: when a threshold exceeding is expected, RL-PC disseminates an alert from yellow to red. The conventional threshold evaluation is based on events at a fixed return period. Anyway, the impacts of events with the same return period may be different along the river course due to the specific characteristics of the affected areas. A new approach is introduced. It defines different scenarios, corresponding to different flood impacts. A discharge threshold is then associated to each scenario and the return period of the scenario is computed backwards. Flood scenarios are defined in accordance with National Civil Protection guidelines, which describe the expected flood impact and associate a colour to the scenario from green (no relevant effects) to red (major floods). A range of discharges is associated with each scenario since they cause the same flood impact; the threshold is set as the discharge corresponding to the transition between two scenarios. A wide range of event-based information is used to estimate the thresholds. As first guess, the thresholds are estimated starting from hydraulic model outputs and the people or infrastructures flooded according to the simulations. Eventually the model estimates are validated with real event knowledge: local Civil Protection Emergency Plans usually contain very detailed local impact description at known river levels or discharges, RL-PC collects flooding information notified by the population, newspapers often report flood events on web, data from the river monitoring network provide evaluation of actually happened levels and discharges. The methodology

  3. Initial external events: floods

    International Nuclear Information System (INIS)

    Drumond, M.M.

    1989-12-01

    The initial external event, specifically flood in a Nuclear power plant, and the calculation necessary to determine the contribution of this type of event in a Probabilistic Safety Analysis, are presented. (M.I.)

  4. Impact of floods induced by extreme precipitation events on public health

    Science.gov (United States)

    Mavroulis, Spyridon; Mavrouli, Maria; Lekkas, Efthymios; Tsakris, Athanassios

    2017-04-01

    Hydrometeorological disasters comprise the most reported type of natural disaster, and floods account for the majority of disasters in this category in both developed and developing countries. Flooding can lead to extensive morbidity and mortality and pose multiple risks to public health throughout the world. This study involved an extensive and systematic literature review of 124 research publications related to public health impact of 98 floods that occurred globally (Oceania 4, Africa 9, America 22, Europe 24, Asia 39) from 1942 to 2014. The inclusion criteria were literature type comprising journal articles and official reports, natural disaster type including floods induced after extreme precipitation events (accumulation of rainwater in poorly-drained environments, riverine and flash floods), population type including humans, and outcome measure characterized by infectious diseases (ID) incidence increase. The potential post-flood ID are classified into 13 groups including rodent-borne (reported in 38 of the total 98 events, 38.78%), water-borne (33, 33.67%), vector-borne (25, 25.51%), respiratory (19, 19.39%), fecal-oral (14, 14.29%), skin (9, 9.18%), blood-borne (4, 4.08%), eye (3, 3.06%), soil-related (3, 3.06%), ear (2, 2.04%), fungal (1, 1.02%) and wound-borne (1, 1.02%) ID. Based on available age and genre data, it is concluded that the most vulnerable population groups are predominantly young children (age ≤ 5 years) and male. The most fatal post-flood ID are leptospirosis and diarrhea followed by respiratory tract infections. The detected risk factors include (1) poor economic status and living in flood prone areas, (2) destruction of infrastructures, disruption of public utilities and interruption of basic public health services such as vector control programs, (3) direct physical exposure to sewage-polluted flood water, (4) lack of adequate potable water and water-supply from contaminated ponds and tube wells along with lack of distribution of

  5. Impact of climate change on extreme rainfall events and flood risk in ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 120; Issue 3 ... Climate changes; extreme rainfall events; flood risk. Abstract. The occurrence of exceptionally heavy rainfall events and associated flash floods in many areas during recent years motivate us to study long-term changes in extreme rainfall over India.

  6. The impact of extreme flooding events and anthropogenic stressors on the macrobenthic communities’ dynamics

    Science.gov (United States)

    Cardoso, P. G.; Raffaelli, D.; Lillebø, A. I.; Verdelhos, T.; Pardal, M. A.

    2008-02-01

    Marine and coastal environments are among the most ecologically and socio-economically important habitats on Earth. However, climate change associated with a variety of anthropogenic stressors (e.g. eutrophication) may interact to produce combined impacts on biodiversity and ecosystem functioning, which in turn will have profound implications for marine ecosystems and the economic and social systems that depend upon them. Over period 1980-2000, the environment of the Mondego estuary, Portugal, has deteriorated through eutrophication, manifested in the replacement of seagrasses by opportunistic macroalgae, degradation of water quality and increased turbidity, and the system has also experienced extreme flood events. A restoration plan was implemented in 1998 which aimed to reverse the eutrophication effects, especially to restore the original natural seagrass ( Zostera noltii) community. This paper explores the interactions between extreme weather events (e.g. intense floods) and anthropogenic stressors (e.g. eutrophication) on the dynamics of the macrobenthic assemblages and the socio-economic implications that follow. We found that during the previous decade, the intensification of extreme flooding events had significant effects on the structure and functioning of macrobenthic communities, specifically a decline in total biomass, a decline in species richness and a decline in suspension feeders. However, the earlier eutrophication process also strongly modified the macrobenthic community, seen as a decline in species richness, increase in detritivores and a decline in herbivores together with a significant increase in small deposit-feeding polychaetes. After the implementation of the management plan, macrobenthic assemblages seemed to be recovering from eutrophication, but it is argued here that those earlier impacts reduced system stability and the resilience of the macrobenthic assemblages, so that its ability to cope with other stressors was compromised. Thus

  7. Impacts of extreme events of drought and flood on local communities of Amazon basin

    Science.gov (United States)

    Borma, L. D.; Roballo, S.; Zauner, M.; Nascimento, V. F.

    2013-05-01

    contingent of about 50% of rural homeless during this event. On the ther side, during the extreme droughts, crops and cattle are likely to perish due to drought. The prolonged dry season threatens local ichthyofauna, promoting an increase in fish mortality. In 1997/98 and 2005 episodes were recorded about 3 months of negative anomalies of discharge, while in 2010, there were about 4 months of negative anomalies during the low water period. According to the data obtained from the Civil Defense, flood events would be more impactful to the local community than the drought ones. However, the absence of quantitative indicators hinders a more precise analysis of the real impacts of drought and flood events in the region. In fact, during the dry season two aspects of extreme importance need to be better addressed: i) the fact that the population of one of the wettest regions of the planet does not have a good water supply for human being, and ii) what are the impacts of extreme drought on the cycle of reproduction of species of local fish fauna?

  8. Impact of climate change on extreme rainfall events and flood risk in ...

    Indian Academy of Sciences (India)

    events help to identify zones of high and low values of extreme rainfall events. A detailed regionalized study is practically useful for planners and other users. Sinha Ray and Srivastava (2000) have done. Keywords. Climate changes; extreme rainfall events; flood risk. J. Earth Syst. Sci. 120, No. 3, June 2011, pp. 359–373.

  9. ASSESSING THE IMPACTS OF FLOODING CAUSED BY EXTREME RAINFALL EVENTS THROUGH A COMBINED GEOSPATIAL AND NUMERICAL MODELING APPROACH

    Directory of Open Access Journals (Sweden)

    J. R. Santillan

    2016-06-01

    Full Text Available In this paper, we present a combined geospatial and two dimensional (2D flood modeling approach to assess the impacts of flooding due to extreme rainfall events. We developed and implemented this approach to the Tago River Basin in the province of Surigao del Sur in Mindanao, Philippines, an area which suffered great damage due to flooding caused by Tropical Storms Lingling and Jangmi in the year 2014. The geospatial component of the approach involves extraction of several layers of information such as detailed topography/terrain, man-made features (buildings, roads, bridges from 1-m spatial resolution LiDAR Digital Surface and Terrain Models (DTM/DSMs, and recent land-cover from Landsat 7 ETM+ and Landsat 8 OLI images. We then used these layers as inputs in developing a Hydrologic Engineering Center Hydrologic Modeling System (HEC HMS-based hydrologic model, and a hydraulic model based on the 2D module of the latest version of HEC River Analysis System (RAS to dynamically simulate and map the depth and extent of flooding due to extreme rainfall events. The extreme rainfall events used in the simulation represent 6 hypothetical rainfall events with return periods of 2, 5, 10, 25, 50, and 100 years. For each event, maximum flood depth maps were generated from the simulations, and these maps were further transformed into hazard maps by categorizing the flood depth into low, medium and high hazard levels. Using both the flood hazard maps and the layers of information extracted from remotely-sensed datasets in spatial overlay analysis, we were then able to estimate and assess the impacts of these flooding events to buildings, roads, bridges and landcover. Results of the assessments revealed increase in number of buildings, roads and bridges; and increase in areas of land-cover exposed to various flood hazards as rainfall events become more extreme. The wealth of information generated from the flood impact assessment using the approach can be very

  10. Validation of the Impact of Event Scale-Revised for adolescents experiencing the floods and mudslides

    Directory of Open Access Journals (Sweden)

    Cheng-Sheng Chen

    2011-12-01

    Full Text Available The purpose of this study was to validate the Impact of Event Scale-Revised (IES-R for adolescents who had experienced the floods and mudslides caused by Typhoon Morakot in Taiwan. The internal consistency, construct validity, and criteria validity of the instrument were examined. Principal component analysis followed by an oblique rotation was used to derive a three-factor solution. These factors were labeled intrusion, hyperarousal, and avoidance; all three factors together accounted for 58.1% of the variance. The total Cronbach’s alpha of 0.94 reflected the good internal consistency of the instrument. With reference to diagnosis of posttraumatic stress disorder, the IES-R cutoff point for posttraumatic stress disorder was 19 of 20 with a sensitivity of 85.7% and specificity of 84.1%. In conclusion, the IES-R can be used as a reliable and valid instrument when evaluating psychological distress among adolescents who have experienced a natural disaster, such as flooding and mudslides.

  11. Impact of climate change on extreme rainfall events and flood risk in ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... The occurrence of exceptionally heavy rainfall events and associated flash floods in many areas during recent years motivate us to study long-term changes in extreme rainfall over India. The analysis of the frequency of rainy days, rain days and heavy rainfall days as well as one-day extreme rainfall and ...

  12. Flood basalts and extinction events

    Science.gov (United States)

    Stothers, Richard B.

    1993-01-01

    The largest known effusive eruptions during the Cenozoic and Mesozoic Eras, the voluminous flood basalts, have long been suspected as being associated with major extinctions of biotic species. Despite the possible errors attached to the dates in both time series of events, the significance level of the suspected correlation is found here to be 1 percent to 4 percent. Statistically, extinctions lag eruptions by a mean time interval that is indistinguishable from zero, being much less than the average residual derived from the correlation analysis. Oceanic flood basalts, however, must have had a different biological impact, which is still uncertain owing to the small number of known examples and differing physical factors. Although not all continental flood basalts can have produced major extinction events, the noncorrelating eruptions may have led to smaller marine extinction events that terminated at least some of the less catastrophically ending geologic stages. Consequently, the 26 Myr quasi-periodicity seen in major marine extinctions may be only a sampling effect, rather than a manifestation of underlying periodicity.

  13. Evolutionary modelling of the macro-economic impacts of catastrophic flood events

    NARCIS (Netherlands)

    Safarzynska, K.E.; Brouwer, R.; Hofkes, M.

    2013-01-01

    This paper examines the possible contribution of evolutionary economics to macro-economic modelling of flood impacts to provide guidance for future economic risk modelling. Most macro-economic models start from a neoclassical economic perspective and focus on equilibrium outcomes, either in a static

  14. The Impacts of Episodic Storm and Flood Events on Carbon and Sediment Delivery to Gulf of Mexico Sediments

    Science.gov (United States)

    Schreiner, K. M.; Carlin, J. A.; Sayers, L.; Swenson, J.

    2017-12-01

    Marine sediments are an important long-term reservoir for both recently fixed organic carbon (OC) and ancient rock derived OC, much of which is delivered by rivers. The ratio between these two sources of OC in turn regulates atmospheric levels of oxygen and carbon dioxide over geologic time, making this riverine delivery of OC, primarily carried by sediments, an important flux in the global carbon cycle. However, while the overall magnitude of these fluxes are relatively well known, it remains to be determined the importance of episodic events, like storms and floods, in the flux of OC from terrestrial to marine environments. Here, we present data from a 34 cm core collected from the Gulf of Mexico at a mid-shelf distal depocenter for the Brazos River in 2015, during a strong El Nino when that area of the country was experiencing 100-year flood events and anomalously high river flow. Based on analysis of the radioactive isotope 7Be, approximately the top 7-8 cm of the sediment in this core was deposited during this flood event. Both bulk elemental (C, N, and stable carbon isotopes) and chemical biomarker (lignin-phenol) data has been combined to provide information of the origin and chemistry of the OC in this core both before and during flooding. C:N and d13C indicate a mixture of marine-sourced and terrestrially-sourced OC throughout the length of the core with very little variation between the flood layer and deeper sediments. However, lignin-phenol concentrations are higher in flood-deposited sediment, indicating that this sediment is likely terrestrially-sourced. Lignin-phenol indicators of OC degradation state (Acid:Aldehyde ratios) indicate that flood sediment is fresher and less degraded than deeper sediments. Taken together, these results indicate that 1. Bulk analyses are not enough to determine OC source and the importance of flood events in OC cycling and 2. Episodic events like floods could have an oversized impact on OC storage in marine sediments.

  15. Impact of agricultural management on pluvial flash floods - Case study of an extreme event observed in Austria in 2016

    Science.gov (United States)

    Lumassegger, Simon; Achleitner, Stefan; Kohl, Bernhard

    2017-04-01

    heavily influenced by land use matches well with the observed flow patterns during the storm event in summer 2016. The results clearly indicate the ability to reduce pluvial flash flood impacts by changing agricultural management practices.

  16. Estimation of the impact of climate change-induced extreme precipitation events on floods

    Science.gov (United States)

    Hlavčová, Kamila; Lapin, Milan; Valent, Peter; Szolgay, Ján; Kohnová, Silvia; Rončák, Peter

    2015-09-01

    In order to estimate possible changes in the flood regime in the mountainous regions of Slovakia, a simple physically-based concept for climate change-induced changes in extreme 5-day precipitation totals is proposed in the paper. It utilizes regionally downscaled scenarios of the long-term monthly means of the air temperature, specific air humidity and precipitation projected for Central Slovakia by two regional (RCM) and two global circulation models (GCM). A simplified physically-based model for the calculation of short-term precipitation totals over the course of changing air temperatures, which is used to drive a conceptual rainfall-runoff model, was proposed. In the paper a case study of this approach in the upper Hron river basin in Central Slovakia is presented. From the 1981-2010 period, 20 events of the basin's most extreme average of 5-day precipitation totals were selected. Only events with continual precipitation during 5 days were considered. These 5-day precipitation totals were modified according to the RCM and GCM-based scenarios for the future time horizons of 2025, 2050 and 2075. For modelling runoff under changed 5-day precipitation totals, a conceptual rainfall-runoff model developed at the Slovak University of Technology was used. Changes in extreme mean daily discharges due to climate change were compared with the original flood events and discussed.

  17. Seawater-flooding events and impact on freshwater lenses of low-lying islands: Controlling factors, basic management and mitigation

    Science.gov (United States)

    Gingerich, Stephen B.; Voss, Clifford I.; Johnson, Adam G.

    2017-01-01

    An unprecedented set of hydrologic observations was collected after the Dec 2008 seawater-flooding event on Roi-Namur, Kwajalein Atoll, Republic of the Marshall Islands. By two days after the seawater flooding that occurred at the beginning of dry season, the observed salinity of water withdrawn by the island’s main skimming well increased to 100% seawater concentration, but by ten days later already decreased to only 10–20% of seawater fraction. However, the damaging impact on the potability of the groundwater supply (when pumped water had concentrations above 1% seawater fraction) lasted 22 months longer. The data collected make possible analyses of the hydrologic factors that control recovery and management of the groundwater-supply quality on Roi-Namur and on similar low-lying islands.With the observed data as a guide, three-dimensional numerical-model simulation analyses reveal how recovery is controlled by the island’s hydrology. These also allow evaluation of the efficacy of basic water-quality management/mitigation alternatives and elucidate how groundwater withdrawal and timing of the seawater-flooding event affect the length of recovery. Simulations show that, as might be expected, by adding surplus captured rainwater as artificial recharge, the freshwater-lens recovery period (after which potable groundwater may again be produced) can be shortened, with groundwater salinity remaining lower even during the dry season, a period during which no artificial recharge is applied. Simulations also show that the recovery period is not lengthened appreciably by groundwater withdrawals during recovery. Simulations further show that had the flooding event occurred at the start of the wet season, the recovery period would have been about 25% (5.5 months) shorter than actually occurred during the monitored flood that occurred at the dry-season start. Finally, analyses show that artificial recharge improves freshwater-lens water quality, making possible longer

  18. Regional economic impacts of natural hazards - the case of the 2005 Alpine flood event in Tyrol (Austria)

    Science.gov (United States)

    Pfurtscheller, C.

    2014-02-01

    Natural hazards have substantial impacts on economies on all scales. While the measurement of direct effects seems manageable, less is known about the dimensions of economic effects, especially on local and regional scales. The lack of standardized terminology, empirical data and methods currently hampers profound decision support. In our study of the 2005 flood event in the Federal State of Tyrol (Austria), which triggered about 264 million Euros in direct losses, we surveyed companies from all sectors of the economy to identify the drivers of economic effects. The main aim of the study was to assess the regional economic impacts on the gross regional product by the 2005 floods without macro-economic modelling techniques using bottom-up data. Using basic quantitative and qualitative methods, we established and analysed a data pool of questionnaire and interview results as well as direct loss data. Based on this empirical evidence, we estimated the decline in gross regional product in the study area at NUTS-3 level. We observed that disrupted traffic networks, for instance, had very negative effects on the regional economy. In addition, we identified economic winners of severe hazard impacts and estimated the amount of increasing economic flows (economic stimuli), based on compensation payments. Finally, the net effect can be estimated balancing the negative and positive effects of the flood event. The methods and results of this study can help to improve ex post loss estimations, and with it, ex ante methods for the cost efficiency of risk reduction measures, e.g. cost-benefit analysis. However, much effort is needed to improve the data basis on economic effects measured as a change in economic flows.

  19. Comparison of the ages of large-body impacts, flood-basalt eruptions, ocean-anoxic events and extinctions over the last 260 million years: a statistical study

    Science.gov (United States)

    Rampino, Michael R.; Caldeira, Ken

    2018-03-01

    Many studies have linked mass extinction events with the catastrophic effects of large-body impacts and flood-basalt eruptions, sometimes as competing explanations. We find that the ages of at least 10 out of a total of 11 documented extinction events over the last 260 Myr (12 out of 13 if we include two lesser extinction events) coincide, within errors, with the best-known ages of either a large impact crater (≥70 km diameter) or a continental flood-basalt eruption. The null hypothesis that this could occur by chance can be rejected with very high confidence (>99.999%). The ages of large impact craters correlate with recognized extinction events at 36 (two impacts), 66, 145 and 215 Myr ago (and possibly an event at 168 Myr ago), and the ages of continental flood basalts correlate with extinctions at 66, 94, 116, 183, 201, 252 and 259 Myr ago (and possibly at 133 Myr ago). Furthermore, at least 7 periods of widespread anoxia in the oceans of the last 260 Myr coincide with the ages of flood-basalt eruptions (with 99.999% confidence), and are coeval with extinctions, suggesting causal connections. These statistical relationships argue that most mass extinction events are related to climatic catastrophes produced by the largest impacts and large-volume continental flood-basalt eruptions.

  20. ICUD-0147 Extreme event statistics of urban pluvial floods – Return period assessment and rainfall variability impacts

    DEFF Research Database (Denmark)

    Tuyls, Damian Murla; Nielsen, Rasmus; Thorndahl, Søren Liedtke

    2017-01-01

    A return period assessment of urban flood has been performed and its adhered impact of rainfall variability studied over a urban drainage catchment area in Aalborg, Denmark. Recorded rainfall from 7 rain gauges has been used, located in a range of 7.5Km and for a period varying form 18-37 years....... Return period of rainfall and flood at catchment and local scale has been estimated, its derived ambiguities analysed and the variability of rain gauge based rainfall investigated regarding to flood estimation results. Results show a clear contrast between rainfall and flood return period estimates...

  1. Health impacts of floods.

    Science.gov (United States)

    Du, Weiwei; FitzGerald, Gerard Joseph; Clark, Michele; Hou, Xiang-Yu

    2010-01-01

    Floods are the most common hazard to cause disasters and have led to extensive morbidity and mortality throughout the world. The impact of floods on the human community is related directly to the location and topography of the area, as well as human demographics and characteristics of the built environment. The aim of this study is to identify the health impacts of disasters and the underlying causes of health impacts associated with floods. A conceptual framework is developed that may assist with the development of a rational and comprehensive approach to prevention, mitigation, and management. This study involved an extensive literature review that located >500 references, which were analyzed to identify common themes, findings, and expert views. The findings then were distilled into common themes. The health impacts of floods are wide ranging, and depend on a number of factors. However, the health impacts of a particular flood are specific to the particular context. The immediate health impacts of floods include drowning, injuries, hypothermia, and animal bites. Health risks also are associated with the evacuation of patients, loss of health workers, and loss of health infrastructure including essential drugs and supplies. In the medium-term, infected wounds, complications of injury, poisoning, poor mental health, communicable diseases, and starvation are indirect effects of flooding. In the long-term, chronic disease, disability, poor mental health, and poverty-related diseases including malnutrition are the potential legacy. This article proposes a structured approach to the classification of the health impacts of floods and a conceptual framework that demonstrates the relationships between floods and the direct and indirect health consequences.

  2. Drivers of flood damage on event level

    DEFF Research Database (Denmark)

    Kreibich, H.; Aerts, J. C. J. H.; Apel, H.

    2016-01-01

    Flood risk is dynamic and influenced by many processes related to hazard, exposure and vulnerability. Flood damage increased significantly over the past decades, however, resulting overall economic loss per event is an aggregated indicator and it is difficult to attribute causes to this increasing...... trend. Much has been learned about damaging processes during floods at the micro-scale, e.g. building level. However, little is known about the main factors determining the amount of flood damage on event level. Thus, we analyse and compare paired flood events, i.e. consecutive, similar damaging floods...... that occurred in the same area. In analogy to ’Paired catchment studies’ - a well-established method in hydrology to understand how changes in land use affect streamflow – we will investigate how and why resulting flood damage in a region differed between the first and second consecutive flood events. One...

  3. Drivers of flood damage on event level

    DEFF Research Database (Denmark)

    Kreibich, H.; Aerts, J. C. J. H.; Apel, H.

    2016-01-01

    -level mitigation measures, 3) more effective early warning and improved coordination of disaster response and 4) a more targeted maintenance of flood defence systems and their deliberate relocation. Thus, despite higher hydrological severity damage due to the 2013 flood was significantly lower than in 2002. In our......Flood risk is dynamic and influenced by many processes related to hazard, exposure and vulnerability. Flood damage increased significantly over the past decades, however, resulting overall economic loss per event is an aggregated indicator and it is difficult to attribute causes to this increasing...... trend. Much has been learned about damaging processes during floods at the micro-scale, e.g. building level. However, little is known about the main factors determining the amount of flood damage on event level. Thus, we analyse and compare paired flood events, i.e. consecutive, similar damaging floods...

  4. Analysis of land cover change impact on flood events using remote sensing, GIS and hydrological models: a case study of the Nyando River Basin in Kenya

    International Nuclear Information System (INIS)

    Olang, L. O.

    2009-01-01

    In this study, land cover changes in the Nyando River basin (3500 km 2 ) of Kenya were analyzed and their impact of floods quantified. Three Landsat satellite images for 1973, 1986 and 2000 were acquired, processed and classified based on seven major land cover classes prevalent in the basin using a hybrid of supervised and non supervised classification procedures. The detected land cover changes, together with a DEM and a soil map of the basin, were then used to estimate physically based parameters for the selected hydrological models. The models were then used to estimate local and flood peak discharges and volumes arising from selected storm events for each state of the classified land cover dataset. To further understand how changes in the land cover may impact on the flood hydrology, three scenarios that represent quite extreme alternatives were formulated to study the possible bandwidth during floods. Land cover classification results revealed immense land degradation over the span of study. Forests reduced by an area of 488 km 2 representing a 20% decline, while agricultural fields expanded by 581 km 2 representing a 16% increase over the same period of time (1973-2000). Hydrological modeling results indicated that the basin underwent significant increase in the peak discharge value. The flood peak discharges in the whole basin were noted to have increased by at least 16% over the period of 1973 -2000.Flood volumes were also noted to have increased by at least 10% over the same period of time. (author) [de

  5. Understanding the effects of past flood events and perceived and estimated flood risks on individuals' voluntary flood insurance purchase behavior.

    Science.gov (United States)

    Shao, Wanyun; Xian, Siyuan; Lin, Ning; Kunreuther, Howard; Jackson, Nida; Goidel, Kirby

    2017-01-01

    Over the past several decades, the economic damage from flooding in the coastal areas has greatly increased due to rapid coastal development coupled with possible climate change impacts. One effective way to mitigate excessive economic losses from flooding is to purchase flood insurance. Only a minority of coastal residents however have taken this preventive measure. Using original survey data for all coastal counties of the United States Gulf Coast merged with contextual data, this study examines the effects of external influences and perceptions of flood-related risks on individuals' voluntary behaviors to purchase flood insurance. It is found that the estimated flood hazard conveyed through the U.S. Federal Emergency Management Agency's (FEMA's) flood maps, the intensities and consequences of past storms and flooding events, and perceived flood-related risks significantly affect individual's voluntary purchase of flood insurance. This behavior is also influenced by home ownership, trust in local government, education, and income. These findings have several important policy implications. First, FEMA's flood maps have been effective in conveying local flood risks to coastal residents, and correspondingly influencing their decisions to voluntarily seek flood insurance in the U.S. Gulf Coast. Flood maps therefore should be updated frequently to reflect timely and accurate information about flood hazards. Second, policy makers should design strategies to increase homeowners' trust in the local government, to better communicate flood risks with residents, to address the affordability issue for the low-income, and better inform less educated homeowners through various educational programs. Future studies should examine the voluntary flood insurance behavior across countries that are vulnerable to flooding. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Considering historical flood events in flood frequency analysis: Is it worth the effort?

    Science.gov (United States)

    Schendel, Thomas; Thongwichian, Rossukon

    2017-07-01

    Information about historical floods can be useful in reducing uncertainties in flood frequency estimation. Since the start of the historical record is often defined by the first known flood, the length of the true historical period M remains unknown. We have expanded a previously published method of estimating M to the case of several known floods within the historical period. We performed a systematic evaluation of the usefulness of including historical flood events into flood frequency analysis for a wide range of return periods and studied bias as well as relative root mean square error (RRMSE). Since we used the generalized extreme value distribution (GEV) as parent distribution, we were able to investigate the impact of varying the skewness on RRMSE. We confirmed the usefulness of historical flood data regarding the reduction of RRMSE, however we found that this reduction is less pronounced the more positively skewed the parent distribution was. Including historical flood information had an ambiguous effect on bias: depending on length and number of known floods of the historical period, bias was reduced for large return periods, but increased for smaller ones. Finally, we customized the test inversion bootstrap for estimating confidence intervals to the case that historical flood events are taken into account into flood frequency analysis.

  7. Flood Progression Modelling and Impact Analysis

    DEFF Research Database (Denmark)

    Mioc, Darka; Anton, François; Nickerson, B.

    that computes floodplain polygons before the flood occurs. This allows emergency managers to access the impact of the flood before it occurs and make the early decisions for evacuation of the population and flood rescue. This research shows that the use of GIS and LiDAR technologies combined with hydrological...... situations than previously done in 2D maps. All parts of a building could be studied in detail in the event of flooding. This provides a better tool for analyzing and preparing for emergency measures. It also presents a photo-realistic situation that can easily be understood. Public administrators who may...

  8. Pan-European stochastic flood event set

    Science.gov (United States)

    Kadlec, Martin; Pinto, Joaquim G.; He, Yi; Punčochář, Petr; Kelemen, Fanni D.; Manful, Desmond; Palán, Ladislav

    2017-04-01

    Impact Forecasting (IF), the model development center of Aon Benfield, has been developing a large suite of catastrophe flood models on probabilistic bases for individual countries in Europe. Such natural catastrophes do not follow national boundaries: for example, the major flood in 2016 was responsible for the Europe's largest insured loss of USD3.4bn and affected Germany, France, Belgium, Austria and parts of several other countries. Reflecting such needs, IF initiated a pan-European flood event set development which combines cross-country exposures with country based loss distributions to provide more insightful data to re/insurers. Because the observed discharge data are not available across the whole Europe in sufficient quantity and quality to permit a detailed loss evaluation purposes, a top-down approach was chosen. This approach is based on simulating precipitation from a GCM/RCM model chain followed by a calculation of discharges using rainfall-runoff modelling. IF set up this project in a close collaboration with Karlsruhe Institute of Technology (KIT) regarding the precipitation estimates and with University of East Anglia (UEA) in terms of the rainfall-runoff modelling. KIT's main objective is to provide high resolution daily historical and stochastic time series of key meteorological variables. A purely dynamical downscaling approach with the regional climate model COSMO-CLM (CCLM) is used to generate the historical time series, using re-analysis data as boundary conditions. The resulting time series are validated against the gridded observational dataset E-OBS, and different bias-correction methods are employed. The generation of the stochastic time series requires transfer functions between large-scale atmospheric variables and regional temperature and precipitation fields. These transfer functions are developed for the historical time series using reanalysis data as predictors and bias-corrected CCLM simulated precipitation and temperature as

  9. Analysis of external flooding events occurred in foreign nuclear power plant sites

    International Nuclear Information System (INIS)

    Li Dan; Cai Hankun; Xiao Zhi; An Hongzhen; Mao Huan

    2013-01-01

    This paper screens and studies 17 external flooding events occurred in foreign NPP sites, analysis the characteristic of external flooding events based on the source of the flooding, the impact on the building, systems and equipment, as well as the threat to nuclear safety. Furthermore, based on the experiences and lessons learned from Fukushima nuclear accident relating to external flooding and countermeasures carried out in the world, some suggestions are proposed in order to improve external flooding response capacity for Chinese NPPs. (authors)

  10. Assessment of Potential Flood Events and Impacts at INL's Proposed Remote-Handled Low-Level Waste Disposal Facility Sites

    Energy Technology Data Exchange (ETDEWEB)

    A. Jeff Sondrup; Annette L. Schafter

    2010-09-01

    Rates, depths, erosion potential, increased subsurface transport rates, and annual exceedance probability for potential flooding scenarios have been evaluated for the on-site alternatives of Idaho National Laboratory’s proposed remote handled low-level waste disposal facility. The on-site disposal facility is being evaluated in anticipation of the closure of the Radioactive Waste Management Complex at the INL. An assessment of flood impacts are required to meet the Department of Energy’s Low-Level Waste requirements (DOE-O 435.1), its natural phenomena hazards assessment criteria (DOE-STD-1023-95), and the Radioactive Waste Management Manual (DOE M 435.1-1) guidance in addition to being required by the National Environmental Policy Act (NEPA) environmental assessment (EA). Potential sources of water evaluated include those arising from (1) local precipitation events, (2) precipitation events occurring off of the INL (off-site precipitation), and (3) increased flows in the Big Lost River in the event of a Mackay Dam failure. On-site precipitation events include potential snow-melt and rainfall. Extreme rainfall events were evaluated for the potential to create local erosion, particularly of the barrier placed over the disposal facility. Off-site precipitation carried onto the INL by the Big Lost River channel was evaluated for overland migration of water away from the river channel. Off-site precipitation sources evaluated were those occurring in the drainage basin above Mackay Reservoir. In the worst-case scenarios, precipitation occurring above Mackay Dam could exceed the dam’s capacity, leading to overtopping, and eventually complete dam failure. Mackay Dam could also fail during a seismic event or as a result of mechanical piping. Some of the water released during dam failure, and contributing precipitation, has the potential of being carried onto the INL in the Big Lost River channel. Resulting overland flows from these flood sources were evaluated for

  11. Flood impacts on a water distribution network

    Science.gov (United States)

    Arrighi, Chiara; Tarani, Fabio; Vicario, Enrico; Castelli, Fabio

    2017-12-01

    Floods cause damage to people, buildings and infrastructures. Water distribution systems are particularly exposed, since water treatment plants are often located next to the rivers. Failure of the system leads to both direct losses, for instance damage to equipment and pipework contamination, and indirect impact, since it may lead to service disruption and thus affect populations far from the event through the functional dependencies of the network. In this work, we present an analysis of direct and indirect damages on a drinking water supply system, considering the hazard of riverine flooding as well as the exposure and vulnerability of active system components. The method is based on interweaving, through a semi-automated GIS procedure, a flood model and an EPANET-based pipe network model with a pressure-driven demand approach, which is needed when modelling water distribution networks in highly off-design conditions. Impact measures are defined and estimated so as to quantify service outage and potential pipe contamination. The method is applied to the water supply system of the city of Florence, Italy, serving approximately 380 000 inhabitants. The evaluation of flood impact on the water distribution network is carried out for different events with assigned recurrence intervals. Vulnerable elements exposed to the flood are identified and analysed in order to estimate their residual functionality and to simulate failure scenarios. Results show that in the worst failure scenario (no residual functionality of the lifting station and a 500-year flood), 420 km of pipework would require disinfection with an estimated cost of EUR 21 million, which is about 0.5 % of the direct flood losses evaluated for buildings and contents. Moreover, if flood impacts on the water distribution network are considered, the population affected by the flood is up to 3 times the population directly flooded.

  12. The Significance of Shifts in Precipitation Patterns: Modelling the Impacts of Climate Change and Glacier Retreat on Extreme Flood Events in Denali National Park, Alaska

    Science.gov (United States)

    Crossman, Jill; Futter, Martyn N.; Whitehead, Paul G.

    2013-01-01

    In glacier-fed systems climate change may have various effects over a range of time scales, including increasing river discharge, flood frequency and magnitude. This study uses a combination of empirical monitoring and modelling to project the impacts of climate change on the glacial-fed Middle Fork Toklat River, Denali National Park, Alaska. We use a regional calibration of the model HBV to account for a paucity of long term observed flow data, validating a local application using glacial mass balance data and summer flow records. Two Global Climate Models (HADCM3 and CGCM2) and two IPCC scenarios (A2 and B2) are used to ascertain potential changes in meteorological conditions, river discharge, flood frequency and flood magnitude. Using remote sensing methods this study refines existing estimates of glacial recession rates, finding that since 2000, rates have increased from 24m per year to 68.5m per year, with associated increases in ablation zone ice loss. GCM projections indicate that over the 21st century these rates will increase still further, most extensively under the CGCM2 model, and A2 scenarios. Due to greater winter precipitation and ice and snow accumulation, glaciers release increasing meltwater quantities throughout the 21st century. Despite increases in glacial melt, results indicate that it is predominantly precipitation that affects river discharge. Three of the four IPCC scenarios project increases in flood frequency and magnitude, events which were primarily associated with changing precipitation patterns, rather than extreme temperature increases or meltwater release. Results suggest that although increasing temperatures will significantly increase glacial melt and winter baseflow, meltwater alone does not pose a significant flood hazard to the Toklat River catchment. Projected changes in precipitation are the primary concern, both through changing snow volumes available for melt, and more directly through increasing catchment runoff. PMID

  13. The significance of shifts in precipitation patterns: modelling the impacts of climate change and glacier retreat on extreme flood events in Denali National Park, Alaska.

    Science.gov (United States)

    Crossman, Jill; Futter, Martyn N; Whitehead, Paul G

    2013-01-01

    In glacier-fed systems climate change may have various effects over a range of time scales, including increasing river discharge, flood frequency and magnitude. This study uses a combination of empirical monitoring and modelling to project the impacts of climate change on the glacial-fed Middle Fork Toklat River, Denali National Park, Alaska. We use a regional calibration of the model HBV to account for a paucity of long term observed flow data, validating a local application using glacial mass balance data and summer flow records. Two Global Climate Models (HADCM3 and CGCM2) and two IPCC scenarios (A2 and B2) are used to ascertain potential changes in meteorological conditions, river discharge, flood frequency and flood magnitude. Using remote sensing methods this study refines existing estimates of glacial recession rates, finding that since 2000, rates have increased from 24 m per year to 68.5m per year, with associated increases in ablation zone ice loss. GCM projections indicate that over the 21(st) century these rates will increase still further, most extensively under the CGCM2 model, and A2 scenarios. Due to greater winter precipitation and ice and snow accumulation, glaciers release increasing meltwater quantities throughout the 21(st) century. Despite increases in glacial melt, results indicate that it is predominantly precipitation that affects river discharge. Three of the four IPCC scenarios project increases in flood frequency and magnitude, events which were primarily associated with changing precipitation patterns, rather than extreme temperature increases or meltwater release. Results suggest that although increasing temperatures will significantly increase glacial melt and winter baseflow, meltwater alone does not pose a significant flood hazard to the Toklat River catchment. Projected changes in precipitation are the primary concern, both through changing snow volumes available for melt, and more directly through increasing catchment runoff.

  14. Adaptation to flood risk: Results of international paired flood event studies

    DEFF Research Database (Denmark)

    Kreibich, Heidi; Di Baldassarre, Giuliano; Vorogushyn, Sergiy

    2017-01-01

    in the same region, with the second flood causing significantly lower damage. These success stories of risk reduction were selected across different socioeconomic and hydro-climatic contexts. The potential of societies to adapt is uncovered by describing triggered societal changes, as well as formal measures...... studies, we find that lower damage caused by the second event was mainly due to significant reductions in vulnerability, for example, via raised risk awareness, preparedness, and improvements of organizational emergency management. Thus, vulnerability reduction plays an essential role for successful......As flood impacts are increasing in large parts of the world, understanding the primary drivers of changes in risk is essential for effective adaptation. To gain more knowledge on the basis of empirical case studies, we analyze eight paired floods, that is, consecutive flood events that occurred...

  15. Loss of life in flood events

    Science.gov (United States)

    Špitalar, Maruša

    2013-04-01

    Natural disasters per se give a negative connotation. They are destructive to material elements in a space, nature itself and represent a threat to peoples' lives and health. Floods, especially flash floods due to its power and happening suddenly cause extensive damage. Hence, they are hard to predict and are characterized with violent movement, lots of lives are lost. Floods are among natural hazards the one causing the highest number of fatalities. Having said that very important aspects are humans' vulnerability, risk perception, their behavior when confronted with hazardous situations and on the other hand issues related to adequate warning signs and canals of communication. It is very important to take into consideration this segments also and not mainly just structural measures. However the aim of this paper is to emphasis mainly the social aspects of floods. It consists of two main parts. First one refers to mans' vulnerability, risk perception when it comes to danger caused by rising waters and how does culture influences peoples' response and reaction to flood causalities. The second part consists of data about detailed information on circumstances of death that have been collected from several different sources from several EU countries. There has been also available information on the age and gender of people who lost lives in flood events. With gender males dominated among death people since tend to risk more in risky situations. There has been also defined a vulnerable age group among flood fatalities. Analysis of circumstance of death enabled us to define risky groups that are very important for flood managers. Further on this is very beneficial also for risk prevention, early warning systems and creating the best canals in order to information about upcoming danger would successfully reach people at hazardous areas and also for the others to avoid them.

  16. The storyline approach : a new way to analyse and improve flood event management

    NARCIS (Netherlands)

    de Bruijn, K. M.; Lips, N.; Gersonius, B.; Middelkoop, H.

    2016-01-01

    Common flood risk analyses often focus on direct impacts corresponding to the maximum depths of flood events. However, this information is not sufficient for risk communication, for the design of flood emergency plans and for the selection of risk management measures. For those issues, not only a

  17. Adaptation to flood risk: Results of international paired flood event studies

    Science.gov (United States)

    Kreibich, Heidi; Di Baldassarre, Giuliano; Vorogushyn, Sergiy; Aerts, Jeroen C. J. H.; Apel, Heiko; Aronica, Giuseppe T.; Arnbjerg-Nielsen, Karsten; Bouwer, Laurens M.; Bubeck, Philip; Caloiero, Tommaso; Chinh, Do T.; Cortès, Maria; Gain, Animesh K.; Giampá, Vincenzo; Kuhlicke, Christian; Kundzewicz, Zbigniew W.; Llasat, Maria Carmen; Mârd, Johanna; Matczak, Piotr; Mazzoleni, Maurizio; Molinari, Daniela; Dung, Nguyen V.; Petrucci, Olga; Schröter, Kai; Slager, Kymo; Thieken, Annegret H.; Ward, Philip J.; Merz, Bruno

    2017-10-01

    As flood impacts are increasing in large parts of the world, understanding the primary drivers of changes in risk is essential for effective adaptation. To gain more knowledge on the basis of empirical case studies, we analyze eight paired floods, that is, consecutive flood events that occurred in the same region, with the second flood causing significantly lower damage. These success stories of risk reduction were selected across different socioeconomic and hydro-climatic contexts. The potential of societies to adapt is uncovered by describing triggered societal changes, as well as formal measures and spontaneous processes that reduced flood risk. This novel approach has the potential to build the basis for an international data collection and analysis effort to better understand and attribute changes in risk due to hydrological extremes in the framework of the IAHSs Panta Rhei initiative. Across all case studies, we find that lower damage caused by the second event was mainly due to significant reductions in vulnerability, for example, via raised risk awareness, preparedness, and improvements of organizational emergency management. Thus, vulnerability reduction plays an essential role for successful adaptation. Our work shows that there is a high potential to adapt, but there remains the challenge to stimulate measures that reduce vulnerability and risk in periods in which extreme events do not occur.

  18. Flood Foresight: A near-real time flood monitoring and forecasting tool for rapid and predictive flood impact assessment

    Science.gov (United States)

    Revilla-Romero, Beatriz; Shelton, Kay; Wood, Elizabeth; Berry, Robert; Bevington, John; Hankin, Barry; Lewis, Gavin; Gubbin, Andrew; Griffiths, Samuel; Barnard, Paul; Pinnell, Marc; Huyck, Charles

    2017-04-01

    The hours and days immediately after a major flood event are often chaotic and confusing, with first responders rushing to mobilise emergency responders, provide alleviation assistance and assess loss to assets of interest (e.g., population, buildings or utilities). Preparations in advance of a forthcoming event are becoming increasingly important; early warning systems have been demonstrated to be useful tools for decision markers. The extent of damage, human casualties and economic loss estimates can vary greatly during an event, and the timely availability of an accurate flood extent allows emergency response and resources to be optimised, reduces impacts, and helps prioritise recovery. In the insurance sector, for example, insurers are under pressure to respond in a proactive manner to claims rather than waiting for policyholders to report losses. Even though there is a great demand for flood inundation extents and severity information in different sectors, generating flood footprints for large areas from hydraulic models in real time remains a challenge. While such footprints can be produced in real time using remote sensing, weather conditions and sensor availability limit their ability to capture every single flood event across the globe. In this session, we will present Flood Foresight (www.floodforesight.com), an operational tool developed to meet the universal requirement for rapid geographic information, before, during and after major riverine flood events. The tool provides spatial data with which users can measure their current or predicted impact from an event - at building, basin, national or continental scales. Within Flood Foresight, the Screening component uses global rainfall predictions to provide a regional- to continental-scale view of heavy rainfall events up to a week in advance, alerting the user to potentially hazardous situations relevant to them. The Forecasting component enhances the predictive suite of tools by providing a local

  19. Case studies of extended model-based flood forecasting: prediction of dike strength and flood impacts

    Science.gov (United States)

    Stuparu, Dana; Bachmann, Daniel; Bogaard, Tom; Twigt, Daniel; Verkade, Jan; de Bruijn, Karin; de Leeuw, Annemargreet

    2017-04-01

    Flood forecasts, warning and emergency response are important components in flood risk management. Most flood forecasting systems use models to translate weather predictions to forecasted discharges or water levels. However, this information is often not sufficient for real time decisions. A sound understanding of the reliability of embankments and flood dynamics is needed to react timely and reduce the negative effects of the flood. Where are the weak points in the dike system? When, how much and where the water will flow? When and where is the greatest impact expected? Model-based flood impact forecasting tries to answer these questions by adding new dimensions to the existing forecasting systems by providing forecasted information about: (a) the dike strength during the event (reliability), (b) the flood extent in case of an overflow or a dike failure (flood spread) and (c) the assets at risk (impacts). This work presents three study-cases in which such a set-up is applied. Special features are highlighted. Forecasting of dike strength. The first study-case focusses on the forecast of dike strength in the Netherlands for the river Rhine branches Waal, Nederrijn and IJssel. A so-called reliability transformation is used to translate the predicted water levels at selected dike sections into failure probabilities during a flood event. The reliability of a dike section is defined by fragility curves - a summary of the dike strength conditional to the water level. The reliability information enhances the emergency management and inspections of embankments. Ensemble forecasting. The second study-case shows the setup of a flood impact forecasting system in Dumfries, Scotland. The existing forecasting system is extended with a 2D flood spreading model in combination with the Delft-FIAT impact model. Ensemble forecasts are used to make use of the uncertainty in the precipitation forecasts, which is useful to quantify the certainty of a forecasted flood event. From global

  20. SMAP observes flooding from land to sea: The Texas event of 2015

    Science.gov (United States)

    Fournier, Severine; Reager, John; Lee, Tong; Vazquez-Cuervo, Jorge; David, Cedric; Gierach, Michelle

    2017-04-01

    Floods can have damaging impacts on both land and sea, yet studies of flooding events tend to focus on only one side of the land/sea continuum. Here we present the first two-sided analysis, focusing on the May 2015 severe flood in Texas. Our investigation benefits from simultaneous measurements of land-surface soil moisture and sea surface salinity from NASA's recent Soil Moisture Active Passive (SMAP) mission as well as ancillary data. We report the comprehensive chronology of the flood event: above average rainfall preceding the flood caused soils to saturate; record rainfall then generated record river discharge; subsequently, an unusual freshwater plume associated with anomalous ocean currents formed in the north-central Gulf of Mexico. Together with the Mississippi River plume further east, the Texas plume created a rare "horseshoe" pattern that have potential biogeochemical implications. Such integrated land/sea analysis of flood evolution can improve impact assessments of future extreme flooding events.

  1. Use of documentary sources on past flood events for flood risk management and land planning

    Science.gov (United States)

    Cœur, Denis; Lang, Michel

    2008-09-01

    The knowledge of past catastrophic events can improve flood risk mitigation policy, with a better awareness against risk. As such historical information is usually available in Europe for the past five centuries, historians are able to understand how past society dealt with flood risk, and hydrologists can include information on past floods into an adapted probabilistic framework. In France, Flood Risk Mitigation Maps are based either on the largest historical known flood event or on the 100-year flood event if it is greater. Two actions can be suggested in terms of promoting the use of historical information for flood risk management: (1) the development of a regional flood data base, with both historical and current data, in order to get a good feedback on recent events and to improve the flood risk education and awareness; (2) the commitment to keep a persistent/perennial management of a reference network of hydrometeorological observations for climate change studies.

  2. Effects of a flooding event on a threatened black bear population in Louisiana

    Science.gov (United States)

    O'Connell-Goode, Kaitlin C.; Lowe, Carrie L.; Clark, Joseph D.

    2014-01-01

    The Louisiana black bear, Ursus americanus luteolus, is listed as threatened under the Endangered Species Act as a result of habitat loss and human-related mortality. Information on population-level responses of large mammals to flooding events is scarce, and we had a unique opportunity to evaluate the viability of the Upper Atchafalaya River Basin (UARB) black bear population before and after a significant flooding event. We began collecting black bear hair samples in 2007 for a DNA mark-recapture study to estimate abundance (N) and apparent survival (φ). In 2011, the Morganza Spillway was opened to divert floodwaters from the Mississippi River through the UARB, inundating > 50% of our study area, potentially impacting recovery of this important bear population. To evaluate the effects of this flooding event on bear population dynamics, we used a robust design multistate model to estimate changes in transition rates from the flooded area to non-flooded area (ψF→NF) before (2007–2010), during (2010–2011) and after (2011–2012) the flood. Average N across all years of study was 63.2 (SE = 5.2), excluding the year of the flooding event. Estimates of ψF→NF increased from 0.014 (SE = 0.010; meaning that 1.4% of the bears moved from the flooded area to non-flooded areas) before flooding to 0.113 (SE = 0.045) during the flood year, and then decreased to 0.028 (SE= 0.035) after the flood. Although we demonstrated a flood effect on transition rates as hypothesized, the effect was small (88.7% of the bears remained in the flooded area during flooding) and φ was unchanged, suggesting that the 2011 flooding event had minimal impact on survival and site fidelity.

  3. The impact of bathymetry input on flood simulations

    Science.gov (United States)

    Khanam, M.; Cohen, S.

    2017-12-01

    Flood prediction and mitigation systems are inevitable for improving public safety and community resilience all over the worldwide. Hydraulic simulations of flood events are becoming an increasingly efficient tool for studying and predicting flood events and susceptibility. A consistent limitation of hydraulic simulations of riverine dynamics is the lack of information about river bathymetry as most terrain data record water surface elevation. The impact of this limitation on the accuracy on hydraulic simulations of flood has not been well studies over a large range of flood magnitude and modeling frameworks. Advancing our understanding of this topic is timely given emerging national and global efforts for developing automated flood predictions systems (e.g. NOAA National Water Center). Here we study the response of flood simulation to the incorporation of different bathymetry and floodplain surveillance source. Different hydraulic models are compared, Mike-Flood, a 2D hydrodynamic model, and GSSHA, a hydrology/hydraulics model. We test a hypothesis that the impact of inclusion/exclusion of bathymetry data on hydraulic model results will vary in its magnitude as a function of river size. This will allow researcher and stake holders more accurate predictions of flood events providing useful information that will help local communities in a vulnerable flood zone to mitigate flood hazards. Also, it will help to evaluate the accuracy and efficiency of different modeling frameworks and gage their dependency on detailed bathymetry input data.

  4. Computerized evaluation of flood impact

    International Nuclear Information System (INIS)

    Gagnon, J.; Quach, T.T.; Marche, C.; Lessard, G.

    1998-01-01

    A computerized evaluation process for assessing the economic impacts of a potential dam failure is described. The DOMINO software, which was developed by Hydro-Quebec, takes into account flow data from dam break simulations of floods, the territory involved, plus the economic evaluations of the real estate and infrastructures affected. Some examples of software applications and impact evaluations are presented. The principal elements involved in estimating economic or other types of impacts induced by natural flooding or dam failure, are: (1) flow forecasting, (2) defining the contour of the involved territory, and (3) accounting for the various impacts identified in the affected zone. Owing to its wide range of functions and utilities, DOMINO has proven to be a very useful, user-friendly and portable decision-making tool. 5 refs., 6 tabs

  5. The role of Natural Flood Management in managing floods in large scale basins during extreme events

    Science.gov (United States)

    Quinn, Paul; Owen, Gareth; ODonnell, Greg; Nicholson, Alex; Hetherington, David

    2016-04-01

    There is a strong evidence database showing the negative impacts of land use intensification and soil degradation in NW European river basins on hydrological response and to flood impact downstream. However, the ability to target zones of high runoff production and the extent to which we can manage flood risk using nature-based flood management solution are less known. A move to planting more trees and having less intense farmed landscapes is part of natural flood management (NFM) solutions and these methods suggest that flood risk can be managed in alternative and more holistic ways. So what local NFM management methods should be used, where in large scale basin should they be deployed and how does flow is propagate to any point downstream? Generally, how much intervention is needed and will it compromise food production systems? If we are observing record levels of rainfall and flow, for example during Storm Desmond in Dec 2015 in the North West of England, what other flood management options are really needed to complement our traditional defences in large basins for the future? In this paper we will show examples of NFM interventions in the UK that have impacted at local scale sites. We will demonstrate the impact of interventions at local, sub-catchment (meso-scale) and finally at the large scale. These tools include observations, process based models and more generalised Flood Impact Models. Issues of synchronisation and the design level of protection will be debated. By reworking observed rainfall and discharge (runoff) for observed extreme events in the River Eden and River Tyne, during Storm Desmond, we will show how much flood protection is needed in large scale basins. The research will thus pose a number of key questions as to how floods may have to be managed in large scale basins in the future. We will seek to support a method of catchment systems engineering that holds water back across the whole landscape as a major opportunity to management water

  6. A Global Geospatial Database of 5000+ Historic Flood Event Extents

    Science.gov (United States)

    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.

  7. A prediction and damage assessment model for snowmelt flood events in middle and high latitudes Region

    Science.gov (United States)

    Qiao, C.; Huang, Q.; Chen, T.; Zhang, X.

    2017-12-01

    In the context of global warming, the snowmelt flood events in the mountainous area of the middle and high latitudes are increasingly frequent and create severe casualties and property damages. Carrying out the prediction and risk assessment of the snowmelt flood is of great importance in the water resources management, the flood warning and prevention. Based on the remote sensing and GIS techniques, the relationships of the variables influencing the snowmelt flood such as the snow area, the snow depth, the air temperature, the precipitation, the land topography and land covers are analyzed and a prediction and damage assessment model for snowmelt floods is developed. This model analyzes and predicts the flood submerging area, flood depth, flood grade, and the damages of different underlying surfaces in the study area in a given time period based on the estimation of snowmelt amount, the snowmelt runoff, the direction and velocity of the flood. Then it was used to predict a snowmelt flood event in the Ertis River Basin in northern Xinjiang, China, during March and June, 2005 and to assess its damages including the damages of roads, transmission lines, settlements caused by the floods and the possible landslides using the hydrological and meteorological data, snow parameter data, DEM data and land use data. A comparison was made between the prediction results from this model and observation data including the flood measurement and its disaster loss data, which suggests that this model performs well in predicting the strength and impact area of snowmelt flood and its damage assessment. This model will be helpful for the prediction and damage assessment of snowmelt flood events in the mountainous area in the middle and high latitudes in spring, which has great social and economic significance because it provides a relatively reliable method for snowmelt flood prediction and reduces the possible damages caused by snowmelt floods.

  8. City-scale accessibility of emergency responders operating during flood events

    Science.gov (United States)

    Green, Daniel; Yu, Dapeng; Pattison, Ian; Wilby, Robert; Bosher, Lee; Patel, Ramila; Thompson, Philip; Trowell, Keith; Draycon, Julia; Halse, Martin; Yang, Lili; Ryley, Tim

    2017-01-01

    Emergency responders often have to operate and respond to emergency situations during dynamic weather conditions, including floods. This paper demonstrates a novel method using existing tools and datasets to evaluate emergency responder accessibility during flood events within the city of Leicester, UK. Accessibility was quantified using the 8 and 10 min legislative targets for emergency provision for the ambulance and fire and rescue services respectively under "normal" no-flood conditions, as well as flood scenarios of various magnitudes (1 in 20-year, 1 in 100-year and 1 in 1000-year recurrence intervals), with both surface water and fluvial flood conditions considered. Flood restrictions were processed based on previous hydrodynamic inundation modelling undertaken and inputted into a Network Analysis framework as restrictions for surface water and fluvial flood events. Surface water flooding was shown to cause more disruption to emergency responders operating within the city due to its widespread and spatially distributed footprint when compared to fluvial flood events of comparable magnitude. Fire and rescue 10 min accessibility was shown to decrease from 100, 66.5, 39.8 and 26.2 % under the no-flood, 1 in 20-year, 1 in 100-year and 1 in 1000-year surface water flood scenarios respectively. Furthermore, total inaccessibility was shown to increase with flood magnitude from 6.0 % under the 1 in 20-year scenario to 31.0 % under the 1 in 100-year flood scenario. Additionally, the evolution of emergency service accessibility throughout a surface water flood event is outlined, demonstrating the rapid impact on emergency service accessibility within the first 15 min of the surface water flood event, with a reduction in service coverage and overlap being observed for the ambulance service during a 1 in 100-year flood event. The study provides evidence to guide strategic planning for decision makers prior to and during emergency response to flood events at the city

  9. Flood events in the southwestern Netherlands and coastal Belgium, 1400-1953.

    NARCIS (Netherlands)

    de Kraker, A.M.J.

    2006-01-01

    This paper focuses on the causes and impacts of flood events between 1400 and 1953 in the estuaries of the rivers Meuse, Rhine and Schelde, and further south along the Belgian coast. Floods in this delta area have been caused by natural mechanisms. In particular, weather extremes such as storm

  10. Decision Support for Flood Event Prediction and Monitoring

    DEFF Research Database (Denmark)

    Mioc, Darka; Anton, François; Liang, Gengsheng

    2007-01-01

    In this paper the development of Web GIS based decision support system for flood events is presented. To improve flood prediction we developed the decision support system for flood prediction and monitoring that integrates hydrological modelling and CARIS GIS. We present the methodology for data...... integration, floodplain delineation, and online map interfaces. Our Web-based GIS model can dynamically display observed and predicted flood extents for decision makers and the general public. The users can access Web-based GIS that models current flood events and displays satellite imagery and digital...... elevation model integrated with flood plain area. The system can show how the flooding prediction based on the output from hydrological modeling for the next 48 hours along the lower Saint John River Valley....

  11. What can we learn from the deadly flash floods? Post Event Review Capability (PERC) analysis of the Bavaria and Baden-Wurttemberg flood events in Summer 2016

    Science.gov (United States)

    Szoenyi, Michael

    2017-04-01

    In May/June 2016, stationary low pressure systems brought intense rainfall with record-braking intensities of well above 100 mm rain in few hours locally in the southern states of Baden-Wurttemberg and Bavaria, Germany. In steep terrains, small channels and creeks became devastating torrents impacting, among others, the villages of Simbach/Inn, Schwäbisch-Gmünd and Braunsbach. Just few days prior, France had also seen devastating rainfall and flooding. Damage in Germany alone is estimated at 2.8 M USD, of which less than 50% are insured. The loss of life was significant, with 18 fatalities reported across the events. This new forensic event analysis as part of Zurich's Post Event Review Capability (PERC) investigates the flash flood events following these record rainfalls in Southern Germany and tries to answer the following questions holistically, across the five capitals (5C) and the full disaster risk management (DRM) cycle, which are key to understanding how to become more resilient to such flood events: - Why have these intense rainfall events led to such devastating consequences? The EU Floods directive and its implementation in the various member states, as well as the 2002 and 2013 Germany floods, have focused on larger rivers and the main asset concentration. The pathway and mechanism of the 2016 floods are very different and need to be better understood. Flash floods and surface flooding may need to become the new focus and be much better communicated to people at risk, as the awareness for such perils has been identified as low. - How can the prevalence for such flash floods be better identified and mapped? Research indicated that affected people and decision makers alike attribute the occurrence of such flash floods as arbitrary, but we argue that hotspots can and must be identified based on an overlay of rainfall intensity maps, topography leading to flash flood processes, and vulnerable assets. In Germany, there are currently no comprehensive hazard

  12. Floods of the Lower Tisza from the late 17th century onwards: frequency, magnitude, seasonality and great flood events

    Science.gov (United States)

    Kiss, Andrea

    2016-04-01

    The present paper is based on a recently developed database including contemporary original, administrative, legal and private source materials (published and archival) as well as media reports related to the floods occurred on the lower sections of the Tisza river in Hungary, with special emphasis on the area of Szeged town. The study area is well-represented by contemporary source evidence from the late 17th century onwards, when the town and its broader area was reoccupied from the Ottoman Turkish Empire. Concerning the applied source materials, the main bases of investigation are the administrative (archival) sources such as town council protocols of Szeged and county meeting protocols of Csanád and Csongrád Counties. In these (legal-)administrative documents damaging events (natural/environmental hazards) were systematically recorded. Moreover, other source types such as taxation-related damage accounts as well as private and official reports, letters and correspondence (published, unpublished) were also included. Concerning published evidence, a most important source is flood reports in contemporary newspapers as well as town chronicles and other contemporary narratives. In the presentation the main focus is on the analysis of flood-rich flood-poor periods of the last ca. 330 years; moreover, the seasonality distribution as well as the magnitude of Tisza flood events are also discussed. Another important aim of the poster is to provide a short overview, in the form of case studies, on the greatest flood events (e.g. duration, magnitude, damages, multi-annual consequences), and their further impacts on the urban and countryside development as well as on (changes in) flood defence strategies. In this respect, especially two flood events, the great (1815-)1816 and the catastrophic 1879 flood (shortly with causes and consequences) - that practically erased Szeged town from the ground - are presented in more detail.

  13. Desorption of dieldrin from field aged sediments: simulating flood events

    NARCIS (Netherlands)

    Smit, M.P.J.; Grotenhuis, J.T.C.; Bruning, H.; Rulkens, W.H.

    2008-01-01

    Background, Aim and Scope With the predicted climate change, it is expected that the chances of flooding may increase. During flood events, sediments will resuspend and when the sediments are polluted, contaminants can be transferred to the surrounding water. Mass transfer of organic compounds like

  14. Linking events, science and media for flood and drought management

    Science.gov (United States)

    Ding, M.; Wei, Y.; Zheng, H.; Zhao, Y.

    2017-12-01

    Throughout history, floods and droughts have been closely related to the development of human riparian civilization. The socio-economic damage caused by floods/droughts appears to be on the rise and the frequency of floods/droughts increases due to global climate change. In this paper, we take a fresh perspective to examine the (dis)connection between events (floods and droughts), research papers and media reports in globally 42 river basins between 1990 and 2012 for better solutions in floods and droughts management. We collected hydrological data from NOAA/ESPL Physical Sciences Division (PSD) and CPC Merged Analysis of Precipitation (CMAP), all relevant scientific papers from Web of Science (WOS) and media records from Emergency Events Database (EM-DAT) during the study period, presented the temporal variability at annual level of these three groups of data, and analysed the (connection) among these three groups of data in typical river basins. We found that 1) the number of flood related reports on both media and research is much more than those on droughts; 2) the concerns of media reports just focused on partial topics (death, severity and damage) and partial catchments (Mediterranean Sea and Nile River); 3) the scientific contribution on floods and droughts were limited within some river basins such as Nile River Basin, Parana River Basin, Savannah River Basin and Murray-Darling River Basin; 4) the scientific contribution on floods and droughts were limited within only a few of disciplines such as Geology, Environmental Sciences & Ecology, Agriculture, Engineering and Forestry. It is recommended that multiple disciplinary contribution and collaboration should be promoted to achieve comprehensive flood/drought management, and science and media should interactively play their valuable roles and in flood/drought issues. Keywords: Floods, droughts, events, science, media, flood and drought management

  15. Assessment of flood Response Characteristics to Urbanization and extreme flood events-Typhoons at Cheongju, Chungbuk

    Science.gov (United States)

    Chang, HyungJoon; Lee, Hyosang; Hwang, Myunggyu; Jang, Sukhwan

    2016-04-01

    The changes of land use influence on the flood characteristics, which depend on rainfall runoff procedures in the catchment. This study assesses the changes of flood characteristics due to land use changes between 1997 and 2012. The catchment model (HEC-HMS) is calibrated with flood events of 1990's and 2000's respectively, then the design rainfall of 100, 200, 500year return period are applied to this model, which represent the catchment in 1990's and 2000's, to assess the flood peaks. Then the extreme flood events (i.e., 6 typhoon events) are applied to assess the flood responses. The results of comparison between 1990's and 2000's show that the flood peak and level of 2000's are increasing and time to peak of 2000's is decreasing comparing to those of 1990's :3% to 78% increase in flood peak, 3% in flood level and 10.2% to 16% decrease in time to peak in 100year return period flood. It is due to decreasing of the farmland area (2.18%), mountainous area (8.88%), and increasing of the urbanization of the area (5.86%). This study also estimates the responses to extreme flood events. The results of 2000's show that the increasing of the flood peak and time to peak comparing to 1990's. It indicates that the extreme rainfall is more responsible at unurbanized catchment ( 2000's), which resulting with a 11% increasing of the peak volume. 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.

  16. A study of the flood events in Cyprus

    Directory of Open Access Journals (Sweden)

    K. Savvidou

    2008-07-01

    Full Text Available Almost every year, localised and in some cases more widespread floodings affect parts of Cyprus, causing damages to properties destruction to infrastructure and housing and sometimes the loss of human life. Various factors such as the meteorological situation and type and intensity of precipitation, the geomorphology, the geology and the human intervention to geomorphology are responsible for flood events. In the present study, only the meteorological situation and the associated mechanisms are examined in an attempt to gain the essential knowledge for improvement of local weather forecasts.

    The study period covers a thirteen-year period, from 1994 to 2006, in which 43 cases of flooding were reported, mainly over urbanized areas. The dominant favorable weather conditions for flood events are either the existence of a depression or weather conditions of convectional type. According to these two factors, the flood events were classified into two categories; the "instability'' category which includes isolated flood events of short duration, and the "depression'' category which includes widespread flood events of long duration.

  17. The Generation of a Stochastic Flood Event Catalogue for Continental USA

    Science.gov (United States)

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

    2017-12-01

    Recent advances in the acquisition of spatiotemporal environmental data and improvements in computational capabilities has enabled the generation of large scale, even global, flood hazard layers which serve as a critical decision-making tool for a range of end users. However, these datasets are designed to indicate only the probability and depth of inundation at a given location and are unable to describe the likelihood of concurrent flooding across multiple sites.Recent research has highlighted that although the estimation of large, widespread flood events is of great value to flood mitigation and insurance industries, to date it has been difficult to deal with this spatial dependence structure in flood risk over relatively large scales. Many existing approaches have been restricted to empirical estimates of risk based on historic events, limiting their capability of assessing risk over the full range of plausible scenarios. Therefore, this research utilises a recently developed model-based approach to describe the multisite joint distribution of extreme river flows across continental USA river gauges. Given an extreme event at a site, the model characterises the likelihood neighbouring sites are also impacted. This information is used to simulate an ensemble of plausible synthetic extreme event footprints from which flood depths are extracted from an existing global flood hazard catalogue. Expected economic losses are then estimated by overlaying flood depths with national datasets defining asset locations, characteristics and depth damage functions. The ability of this approach to quantify probabilistic economic risk and rare threshold exceeding events is expected to be of value to those interested in the flood mitigation and insurance sectors.This work describes the methodological steps taken to create the flood loss catalogue over a national scale; highlights the uncertainty in the expected annual economic vulnerability within the USA from extreme river flows

  18. Stochastic Generation of Spatiotemporal Rainfall Events for Flood Risk Assessment

    Science.gov (United States)

    Diederen, D.; Liu, Y.; Gouldby, B.; Diermanse, F.

    2017-12-01

    Current flood risk analyses that only consider peaks of hydrometeorological forcing variables have limitations regarding their representation of reality. Simplistic assumptions regarding antecedent conditions are required, often different sources of flooding are considered in isolation, and the complex temporal and spatial evolution of the events is not considered. Mid-latitude storms, governed by large scale climatic conditions, often exhibit a high degree of temporal dependency, for example. For sustainable flood risk management, that accounts appropriately for climate change, it is desirable for flood risk analyses to reflect reality more appropriately. Analysis of risk mitigation measures and comparison of their relative performance is therefore likely to be more robust and lead to improved solutions. We provide a new framework for the provision of boundary conditions to flood risk analyses that more appropriately reflects reality. The boundary conditions capture the temporal dependencies of complex storms whilst preserving the extreme values and associated spatial dependencies. We demonstrate the application of this framework to generate a synthetic rainfall events time series boundary condition set from reanalysis rainfall data (CFSR) on the continental scale. We define spatiotemporal clusters of rainfall as events, extract hydrological parameters for each event, generate synthetic parameter sets with a multivariate distribution with a focus on the joint tail probability [Heffernan and Tawn, 2004], and finally create synthetic events from the generated synthetic parameters. We highlight the stochastic integration of (a) spatiotemporal features, e.g. event occurrence intensity over space-time, or time to previous event, which we use for the spatial placement and sequencing of the synthetic events, and (b) value-specific parameters, e.g. peak intensity and event extent. We contrast this to more traditional approaches to highlight the significant improvements in

  19. Impact of floods on heritage structures

    Czech Academy of Sciences Publication Activity Database

    Drdácký, Miloš

    2010-01-01

    Roč. 24, č. 5 (2010), s. 430-431 ISSN 0887-3828 Grant - others:evropská komise(XE) FP6 Project cultural heritage protection against flood CHEF-SSPI-044251 Institutional research plan: CEZ:AV0Z20710524 Keywords : flood * heritage structures * damage assessment Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 0.293, year: 2010

  20. FLOOD MENACE IN KADUNA METROPOLIS: IMPACTS ...

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    ABSTRACT. This study assesses how Kaduna Metropolis have been affected by flood menace incidences as it takes a look at the devastating impacts, remedial and management strategies at curbing flooding in Kaduna Metropolis which has almost become a yearly occurrence. Data for this study were obtained from.

  1. The Impact of Corps Flood Control Reservoirs in the June 2008 Upper Mississippi Flood

    Science.gov (United States)

    Charley, W. J.; Stiman, J. A.

    2008-12-01

    The US Army Corps of Engineers is responsible for a multitude of flood control project on the Mississippi River and its tributaries, including levees that protect land from flooding, and dams to help regulate river flows. The first six months of 2008 were the wettest on record in the upper Mississippi Basin. During the first 2 weeks of June, rainfall over the Midwest ranged from 6 to as much as 16 inches, overwhelming the flood protection system, causing massive flooding and damage. Most severely impacted were the States of Iowa, Illinois, Indiana, Missouri, and Wisconsin. In Iowa, flooding occurred on almost every river in the state. On the Iowa River, record flooding occurred from Marshalltown, Iowa, downstream to its confluence with the Mississippi River. At several locations, flooding exceeded the 500-year event. The flooding affected agriculture, transportation, and infrastructure, including homes, businesses, levees, and other water-control structures. It has been estimated that there was at least 7 billion dollars in damages. While the flooding in Iowa was extraordinary, Corps of Engineers flood control reservoirs helped limit damage and prevent loss of life, even though some reservoirs were filled beyond their design capacity. Coralville Reservoir on the Iowa River, for example, filled to 135% of its design flood storage capacity, with stage a record five feet over the crest of the spillway. In spite of this, the maximum reservoir release was limited to 39,500 cfs, while a peak inflow of 57,000 cfs was observed. CWMS, the Corps Water Management System, is used to help regulate Corps reservoirs, as well as track and evaluate flooding and flooding potential. CWMS is a comprehensive data acquisition and hydrologic modeling system for short-term decision support of water control operations in real time. It encompasses data collection, validation and transformation, data storage, visualization, real time model simulation for decision-making support, and data

  2. Impact of rainfall spatial variability on Flash Flood Forecasting

    Science.gov (United States)

    Douinot, Audrey; Roux, Hélène; Garambois, Pierre-André; Larnier, Kevin

    2014-05-01

    built for each studied catchment. The proposed methodology is applied on three Mediterranean catchments often submitted to flash floods. The new forecasting method as well as the Flash Flood Guidance method (uniform rainfall threshold) are tested on 25 flash floods events that had occurred on those catchments. Results show a significant impact of rainfall spatial variability. Indeed, it appears that the uniform rainfall threshold (FFG threshold) always overestimates the observed rainfall threshold. The difference between the FFG threshold and the proposed threshold ranges from 8% to 30%. The proposed methodology allows the calculation of a threshold more representative of the observed one. However, results strongly depend on the related event duration and on the catchment properties. For instance, the impact of the rainfall spatial variability seems to be correlated with the catchment size. According to these results, it seems to be interesting to introduce information on the catchment properties in the threshold calculation. Flash Flood Guidance Improvement Team, 2003. River Forecast Center (RFC) Development Management Team. Final Report. Office of Hydrologic Development (OHD), Silver Spring, Mary-land. Le Lay, M. and Saulnier, G.-M., 2007. Exploring the signature of climate and landscape spatial variabilities in flash flood events: Case of the 8-9 September 2002 Cévennes-Vivarais catastrophic event. Geophysical Research Letters, 34(L13401), doi:10.1029/2007GL029746. Roux, H., Labat, D., Garambois, P.-A., Maubourguet, M.-M., Chorda, J. and Dartus, D., 2011. A physically-based parsimonious hydrological model for flash floods in Mediterranean catchments. Nat. Hazards Earth Syst. Sci. J1 - NHESS, 11(9), 2567-2582. Zoccatelli, D., Borga, M., Zanon, F., Antonescu, B. and Stancalie, G., 2010. Which rainfall spatial information for flash flood response modelling? A numerical investigation based on data from the Carpathian range, Romania. Journal of Hydrology, 394(1-2), 148-161.

  3. Shock events and flood risk management: a media analysis of the institutional long-term effects of flood events in the Netherlands and Poland

    Directory of Open Access Journals (Sweden)

    Maria Kaufmann

    2016-12-01

    Full Text Available Flood events that have proven to create shock waves in society, which we will call shock events, can open windows of opportunity that allow different actor groups to introduce new ideas. Shock events, however, can also strengthen the status quo. We will take flood events as our object of study. Whereas others focus mainly on the immediate impact and disaster management, we will focus on the long-term impact on and resilience of flood risk governance arrangements. Over the last 25 years, both the Netherlands and Poland have suffered several flood-related events. These triggered strategic and institutional changes, but to different degrees. In a comparative analysis these endogenous processes, i.e., the importance of framing of the flood event, its exploitation by different actor groups, and the extent to which arrangements are actually changing, are examined. In line with previous research, our analysis revealed that shock events test the capacity to resist and bounce back and provide opportunities for adapting and learning. They "open up" institutional arrangements and make them more susceptible to change, increasing the opportunity for adaptation. In this way they can facilitate a shift toward different degrees of resilience, i.e., by adjusting the current strategic approach or by moving toward another strategic approach. The direction of change is influenced by the actors and the frames they introduce, and their ability to increase the resonance of the frame. The persistence of change seems to be influenced by the evolution of the initial management approach, the availability of resources, or the willingness to allocate resources.

  4. A new flood type classification method for use in climate change impact studies

    Directory of Open Access Journals (Sweden)

    Thea Turkington

    2016-12-01

    Full Text Available Flood type classification is an optimal tool to cluster floods with similar meteorological triggering conditions. Under climate change these flood types may change differently as well as new flood types develop. This paper presents a new methodology to classify flood types, particularly for use in climate change impact studies. A weather generator is coupled with a conceptual rainfall-runoff model to create long synthetic records of discharge to efficiently build an inventory with high number of flood events. Significant discharge days are classified into causal types using k-means clustering of temperature and precipitation indicators capturing differences in rainfall amount, antecedent rainfall and snow-cover and day of year. From climate projections of bias-corrected temperature and precipitation, future discharge and associated change in flood types are assessed. The approach is applied to two different Alpine catchments: the Ubaye region, a small catchment in France, dominated by rain-on-snow flood events during spring, and the larger Salzach catchment in Austria, affected more by rainfall summer/autumn flood events. The results show that the approach is able to reproduce the observed flood types in both catchments. Under future climate scenarios, the methodology identifies changes in the distribution of flood types and characteristics of the flood types in both study areas. The developed methodology has potential to be used flood impact assessment and disaster risk management as future changes in flood types will have implications for both the local social and ecological systems in the future.

  5. Appropriate modelling of climate change impacts on river flooding

    NARCIS (Netherlands)

    Booij, Martijn J.

    2002-01-01

    Global climate change is likely to increase temperatures, change precipitation patterns and probably raise the frequency of extreme events. Impacts of climate change on river flooding may be considerable and may cause enormous economical, social and environmental damage and even loss of lives. This

  6. Documentary evidence of historical floods and extreme rainfall events in Sweden 1400-1800

    Science.gov (United States)

    Retsö, D.

    2015-03-01

    This article explores documentary evidence of floods and extreme rainfall events in Sweden in the pre-instrumental period (1400-1800). The survey shows that two sub-periods can be considered as flood-rich, 1590-1670 and the early 18th century. The result related to a low degree of human impact on hydrology during the period, suggests that climatic factors, such as lower temperatures and increased precipitation connected to the so-called Little Ice Age rather than large-scale atmospheric circulation patterns, should be considered as the main driver behind flood frequency and magnitude.

  7. The management of urban surface water flood risks: SUDS performance in flood reduction from extreme events.

    Science.gov (United States)

    Viavattene, C; Ellis, J B

    2013-01-01

    The need to improve the urban drainage network to meet recent urban growth and the redevelopment of old industrial and commercial areas provides an opportunity for managing urban surface water infrastructure in a more sustainable way. The use of sustainable urban drainage systems (SUDS) can reduce urban surface water flooding as well as the pollution impact of urban discharges on receiving waters. However, these techniques are not yet well known by many stakeholders involved in the decision-making process, or at least the evidence of their performance effectiveness may be doubted compared with more traditional engineering solutions often promoted by existing 1D/2D drainage models. The use of geographic information systems (GIS) in facilitating the inter-related risk analysis of sewer surface water overflows and urban flooding as well as in better communication with stakeholders is demonstrated in this paper. An innovative coupled 1D/2D urban sewer/overland flow model has been developed and tested in conjunction with a SUDS selection and location tool (SUDSLOC) to enable a robust management approach to surface water flood risks and to improve the resilience of the urban drainage infrastructure. The paper demonstrates the numerical and modelling basis of the integrated 1D/2D and SUDSLOC approach and the working assumptions and flexibility of the application together with some limitations and uncertainties. The role of the SUDSLOC modelling component in quantifying flow, and surcharge reduction benefits arising from the strategic selection and location of differing SUDS controls are also demonstrated for an extreme storm event scenario.

  8. Estimation of Damage Costs Associated with Flood Events

    Science.gov (United States)

    Andrews, T. A.; Wauthier, C.; Zipp, K.

    2017-12-01

    This study investigates the possibility of creating a mathematical function that enables the estimation of flood-damage costs. We begin by examining the costs associated with past flood events in the United States. The data on these tropical storms and hurricanes are provided by the National Oceanic and Atmospheric Administration. With the location, extent of flooding, and damage reparation costs identified, we analyze variables such as: number of inches rained, land elevation, type of landscape, region development in regards to building density and infrastructure, and population concentration. We seek to identify the leading drivers of high flood-damage costs and understand which variables play a large role in the costliness of these weather events. Upon completion of our mathematical analysis, we turn out attention to the 2017 natural disaster of Texas. We divide the region, as we did above, by land elevation, type of landscape, region development in regards to building density and infrastructure, and population concentration. Then, we overlay the number of inches rained in those regions onto the divided landscape and apply our function. We hope to use these findings to estimate the potential flood-damage costs of Hurricane Harvey. This information is then transformed into a hazard map that could provide citizens and businesses of flood-stricken zones additional resources for their insurance selection process.

  9. Impact of multiple radar reflectivity data assimilation on the numerical simulation of a flash flood event during the HyMeX campaign

    Science.gov (United States)

    Maiello, Ida; Gentile, Sabrina; Ferretti, Rossella; Baldini, Luca; Roberto, Nicoletta; Picciotti, Errico; Alberoni, Pier Paolo; Silvio Marzano, Frank

    2017-11-01

    An analysis to evaluate the impact of multiple radar reflectivity data with a three-dimensional variational (3-D-Var) assimilation system on a heavy precipitation event is presented. The main goal is to build a regionally tuned numerical prediction model and a decision-support system for environmental civil protection services and demonstrate it in the central Italian regions, distinguishing which type of observations, conventional and not (or a combination of them), is more effective in improving the accuracy of the forecasted rainfall. In that respect, during the first special observation period (SOP1) of HyMeX (Hydrological cycle in the Mediterranean Experiment) campaign several intensive observing periods (IOPs) were launched and nine of which occurred in Italy. Among them, IOP4 is chosen for this study because of its low predictability regarding the exact location and amount of precipitation. This event hit central Italy on 14 September 2012 producing heavy precipitation and causing several cases of damage to buildings, infrastructure, and roads. Reflectivity data taken from three C-band Doppler radars running operationally during the event are assimilated using the 3-D-Var technique to improve high-resolution initial conditions. In order to evaluate the impact of the assimilation procedure at different horizontal resolutions and to assess the impact of assimilating reflectivity data from multiple radars, several experiments using the Weather Research and Forecasting (WRF) model are performed. Finally, traditional verification scores such as accuracy, equitable threat score, false alarm ratio, and frequency bias - interpreted by analysing their uncertainty through bootstrap confidence intervals (CIs) - are used to objectively compare the experiments, using rain gauge data as a benchmark.

  10. Impact of multiple radar reflectivity data assimilation on the numerical simulation of a flash flood event during the HyMeX campaign

    Directory of Open Access Journals (Sweden)

    I. Maiello

    2017-11-01

    Full Text Available An analysis to evaluate the impact of multiple radar reflectivity data with a three-dimensional variational (3-D-Var assimilation system on a heavy precipitation event is presented. The main goal is to build a regionally tuned numerical prediction model and a decision-support system for environmental civil protection services and demonstrate it in the central Italian regions, distinguishing which type of observations, conventional and not (or a combination of them, is more effective in improving the accuracy of the forecasted rainfall. In that respect, during the first special observation period (SOP1 of HyMeX (Hydrological cycle in the Mediterranean Experiment campaign several intensive observing periods (IOPs were launched and nine of which occurred in Italy. Among them, IOP4 is chosen for this study because of its low predictability regarding the exact location and amount of precipitation. This event hit central Italy on 14 September 2012 producing heavy precipitation and causing several cases of damage to buildings, infrastructure, and roads. Reflectivity data taken from three C-band Doppler radars running operationally during the event are assimilated using the 3-D-Var technique to improve high-resolution initial conditions. In order to evaluate the impact of the assimilation procedure at different horizontal resolutions and to assess the impact of assimilating reflectivity data from multiple radars, several experiments using the Weather Research and Forecasting (WRF model are performed. Finally, traditional verification scores such as accuracy, equitable threat score, false alarm ratio, and frequency bias – interpreted by analysing their uncertainty through bootstrap confidence intervals (CIs – are used to objectively compare the experiments, using rain gauge data as a benchmark.

  11. Modeling flood reduction effects of low impact development at a watershed scale.

    Science.gov (United States)

    Ahiablame, Laurent; Shakya, Ranish

    2016-04-15

    Low impact development (LID) is a land development approach that seeks to mimic a site's pre-development hydrology. This study is a case study that assessed flood reduction capabilities of large-scale adoption of LID practices in an urban watershed in central Illinois using the Personal Computer Storm Water Management Model (PCSWMM). Two flood metrics based on runoff discharge were developed to determine action flood (43 m(3)/s) and major flood (95 m(3)/s). Four land use scenarios for urban growth were evaluated to determine the impacts of urbanization on runoff and flooding. Flood attenuation effects of porous pavement, rain barrel, and rain garden at various application levels were also evaluated as retrofitting technologies in the study watershed over a period of 30 years. Simulation results indicated that increase in urban land use from 50 to 94% between 1992 and 2030 increased average annual runoff and flood events by more than 30%, suggesting that urbanization without sound management would increase flood risks. The various implementation levels of the three LID practices resulted in 3-47% runoff reduction in the study watershed. Flood flow events that include action floods and major floods were also reduced by 0-40%, indicating that LID practices can be used to mitigate flood risk in urban watersheds. The study provides an insight into flood management with LID practices in existing urban areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Impact of an extreme climatic event on community assembly

    OpenAIRE

    Thibault, Katherine M.; Brown, James H.

    2008-01-01

    Extreme climatic events are predicted to increase in frequency and magnitude, but their ecological impacts are poorly understood. Such events are large, infrequent, stochastic perturbations that can change the outcome of entrained ecological processes. Here we show how an extreme flood event affected a desert rodent community that has been monitored for 30 years. The flood (i) caused catastrophic, species-specific mortality; (ii) eliminated the incumbency advantage of previously dominant spec...

  13. Determining the Financial Impact of Flood Hazards in Ungaged Basins

    Science.gov (United States)

    Cotterman, K. A.; Gutenson, J. L.; Pradhan, N. R.; Byrd, A.

    2017-12-01

    Many portions of the Earth lack adequate authoritative or in situ data that is of great value in determining natural hazard vulnerability from both anthropogenic and physical perspective. Such locations include the majority of developing nations, which do not possess adequate warning systems and protective infrastructure. The lack of warning and protection from natural hazards make these nations vulnerable to the destructive power of events such as floods. The goal of this research is to demonstrate an initial workflow with which to characterize flood financial hazards with global datasets and crowd-sourced, non-authoritative data in ungagged river basins. This workflow includes the hydrologic and hydraulic response of the watershed to precipitation, characterized by the physics-based modeling application Gridded Surface-Subsurface Hydrologic Analysis (GSSHA) model. In addition, data infrastructure and resources are available to approximate the human impact of flooding. Open source, volunteer geographic information (VGI) data can provide global coverage of elements at risk of flooding. Additional valuation mechanisms can then translate flood exposure into percentage and financial damage to each building. The combinations of these tools allow the authors to remotely assess flood hazards with minimal computational, temporal, and financial overhead. This combination of deterministic and stochastic modeling provides the means to quickly characterize watershed flood vulnerability and will allow emergency responders and planners to better understand the implications of flooding, both spatially and financially. In either a planning, real-time, or forecasting scenario, the system will assist the user in understanding basin flood vulnerability and increasing community resiliency and preparedness.

  14. Long-term socioeconomic impacts of flooding in Bangladesh

    Science.gov (United States)

    Jina, A.

    2013-05-01

    Natural disasters lead to myriad negative impacts upon society, causing loss of life, property, and income. Among disasters, floods annually affect the most people, and lead to widespread negative outcomes, particularly in developing countries. While immediate effects of disasters are readily observed, long-term socioeconomic effects have received little attention. Recent work in development economics finds that environmental exposure in early life can have negative impacts upon later outcomes in health, education, and labor markets. Such research is problematic for disasters, however, as objective measurements of hazard exposure are difficult to obtain. This study develops a remote sensing method to detect flooding in Bangladesh, one of the most flood-prone countries, using MODIS 8-day composite data. This approach addresses one of the main problems in the literature on the social impacts of disasters by deriving an objective measure rather than using self-reported damages. Flood data from 2000-2012 is matched to geolocated social surveys conducted by the Bangladesh government to identify impacts of exposure to floods at critical periods of life. While flooding is noted to be a natural and important part of ecosystem functioning in Bangladesh, we aim to understand the impacts of a flood of greater than normal magnitude or abnormal timing to identify the effects on human capital formation. We find that an increase in flooding of one standard deviation (SD) above the mean in the birth month leads to a 3% increase in stunting (2 SD below cohort height). This has implications for physical and cognitive development, shown elsewhere to persist to adulthood. We find that children from households that are exposed to floods while in elementary school are more likely to drop out. Other impacts will be identified in the course of this research. The stated impacts suggest that the long-term health and economic fortunes of the rural poor in Bangladesh are significantly

  15. Shock events and flood risk management: a media analysis of the institutional long-term effects of flood events in the Netherlands and Poland

    NARCIS (Netherlands)

    Kaufmann, M.; Lewandowski, J.; Chorynski, A.; Wiering, M.A.

    2016-01-01

    Flood events that have proven to create shock waves in society, which we will call shock events, can open windows of opportunity that allow different actor groups to introduce new ideas. Shock events, however, can also strengthen the status quo. We will take flood events as our object of study.

  16. Projections of hepatitis A virus infection associated with flood events by 2020 and 2030 in Anhui Province, China

    Science.gov (United States)

    Gao, Lu; Zhang, Ying; Ding, Guoyong; Liu, Qiyong; Wang, Changke; Jiang, Baofa

    2016-12-01

    Assessing and responding to health risk of climate change is important because of its impact on the natural and societal ecosystems. More frequent and severe flood events will occur in China due to climate change. Given that population is projected to increase, more people will be vulnerable to flood events, which may lead to an increased incidence of HAV infection in the future. This population-based study is going to project the future health burden of HAV infection associated with flood events in Huai River Basin of China. The study area covered four cities of Anhui province in China, where flood events were frequent. Time-series adjusted Poisson regression model was developed to quantify the risks of flood events on HAV infection based on the number of daily cases during summer seasons from 2005 to 2010, controlling for other meteorological variables. Projections of HAV infection in 2020 and 2030 were estimated based on the scenarios of flood events and demographic data. Poisson regression model suggested that compared with the periods without flood events, the risks of severe flood events for HAV infection were significant (OR = 1.28, 95 % CI 1.05-1.55), while risks were not significant from moderate flood events (OR = 1.16, 95 % CI 0.72-1.87) and mild flood events (OR = 1.14, 95 % CI 0.87-1.48). Using the 2010 baseline data and the flood event scenarios (one severe flood event), increased incidence of HAV infection were estimated to be between 0.126/105 and 0.127/105 for 2020. Similarly, the increased HAV infection incidence for 2030 was projected to be between 0.382/105 and 0.399/105. Our study has, for the first time, quantified the increased incidence of HAV infection that will result from flood events in Anhui, China, in 2020 and 2030. The results have implications for public health preparation for developing public health responses to reduce HAV infection during future flood events.

  17. Miocene flooding events of western Amazonia.

    Science.gov (United States)

    Jaramillo, Carlos; Romero, Ingrid; D'Apolito, Carlos; Bayona, German; Duarte, Edward; Louwye, Stephen; Escobar, Jaime; Luque, Javier; Carrillo-Briceño, Jorge D; Zapata, Vladimir; Mora, Alejandro; Schouten, Stefan; Zavada, Michael; Harrington, Guy; Ortiz, John; Wesselingh, Frank P

    2017-05-01

    There is a considerable controversy about whether western Amazonia was ever covered by marine waters during the Miocene [23 to 5 Ma (million years ago)]. We investigated the possible occurrence of Miocene marine incursions in the Llanos and Amazonas/Solimões basins, using sedimentological and palynological data from two sediment cores taken in eastern Colombia and northwestern Brazil together with seismic information. We observed two distinct marine intervals in the Llanos Basin, an early Miocene that lasted ~0.9 My (million years) (18.1 to 17.2 Ma) and a middle Miocene that lasted ~3.7 My (16.1 to 12.4 Ma). These two marine intervals are also seen in Amazonas/Solimões Basin (northwestern Amazonia) but were much shorter in duration, ~0.2 My (18.0 to 17.8 Ma) and ~0.4 My (14.1 to 13.7 Ma), respectively. Our results indicate that shallow marine waters covered the region at least twice during the Miocene, but the events were short-lived, rather than a continuous full-marine occupancy of Amazonian landscape over millions of years.

  18. MobRISK: a model for assessing the exposure of road users to flash flood events

    Directory of Open Access Journals (Sweden)

    S. Shabou

    2017-09-01

    Full Text Available Recent flash flood impact studies highlight that road networks are often disrupted due to adverse weather and flash flood events. Road users are thus particularly exposed to road flooding during their daily mobility. Previous exposure studies, however, do not take into consideration population mobility. Recent advances in transportation research provide an appropriate framework for simulating individual travel-activity patterns using an activity-based approach. These activity-based mobility models enable the prediction of the sequence of activities performed by individuals and locating them with a high spatial–temporal resolution. This paper describes the development of the MobRISK microsimulation system: a model for assessing the exposure of road users to extreme hydrometeorological events. MobRISK aims at providing an accurate spatiotemporal exposure assessment by integrating travel-activity behaviors and mobility adaptation with respect to weather disruptions. The model is applied in a flash-flood-prone area in southern France to assess motorists' exposure to the September 2002 flash flood event. The results show that risk of flooding mainly occurs in principal road links with considerable traffic load. However, a lag time between the timing of the road submersion and persons crossing these roads contributes to reducing the potential vehicle-related fatal accidents. It is also found that sociodemographic variables have a significant effect on individual exposure. Thus, the proposed model demonstrates the benefits of considering spatiotemporal dynamics of population exposure to flash floods and presents an important improvement in exposure assessment methods. Such improved characterization of road user exposures can present valuable information for flood risk management services.

  19. MobRISK: a model for assessing the exposure of road users to flash flood events

    Science.gov (United States)

    Shabou, Saif; Ruin, Isabelle; Lutoff, Céline; Debionne, Samuel; Anquetin, Sandrine; Creutin, Jean-Dominique; Beaufils, Xavier

    2017-09-01

    Recent flash flood impact studies highlight that road networks are often disrupted due to adverse weather and flash flood events. Road users are thus particularly exposed to road flooding during their daily mobility. Previous exposure studies, however, do not take into consideration population mobility. Recent advances in transportation research provide an appropriate framework for simulating individual travel-activity patterns using an activity-based approach. These activity-based mobility models enable the prediction of the sequence of activities performed by individuals and locating them with a high spatial-temporal resolution. This paper describes the development of the MobRISK microsimulation system: a model for assessing the exposure of road users to extreme hydrometeorological events. MobRISK aims at providing an accurate spatiotemporal exposure assessment by integrating travel-activity behaviors and mobility adaptation with respect to weather disruptions. The model is applied in a flash-flood-prone area in southern France to assess motorists' exposure to the September 2002 flash flood event. The results show that risk of flooding mainly occurs in principal road links with considerable traffic load. However, a lag time between the timing of the road submersion and persons crossing these roads contributes to reducing the potential vehicle-related fatal accidents. It is also found that sociodemographic variables have a significant effect on individual exposure. Thus, the proposed model demonstrates the benefits of considering spatiotemporal dynamics of population exposure to flash floods and presents an important improvement in exposure assessment methods. Such improved characterization of road user exposures can present valuable information for flood risk management services.

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

    Science.gov (United States)

    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.

  1. THE SEPTEMBER 2013 RAIN AND FLOOD EVENTS IN THE FLAM’S VALLEY BASIN. CAUSES, CHARACTERISTICS AND THEIR IMPACT UPON THE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    BORCAN MIHAELA

    2014-03-01

    Full Text Available Between 11.09 and 14.09 2013 the north-eastern part of Tulcea County, especially the areas located around Somova village was affected by heavy, torrential rainfall that totalized over 30 mm/sq m and triggered dangerous hydrological phenomena (important slope, stream and river flows. As a result of these heavy downpours, Flam’s Valley was affected by an exceptional flash-flood which measured a peak discharge that reached a 1% exceeding probability. Another destructive characteristic of the weather phenomena that occurred in September 2013 was that the heavy rain was accompanied by violent gusty winds that resembled tornado-like features, bringing serious threat to houses, households and roads. In this paper we have analyzed the weather features that produced the September 2013 flash flood from both a spatial and a temporal perspective. The hydrological analysis focuses on the peak discharge that was recorded during the flash flood as well as on the characteristics elements of the topographic profiles. The paper ends with a brief presentation of the consequences that the weather and hydrological phenomena had upon the environment and population as well.

  2. Revisiting the 1993 historical extreme precipitation and damaging flood event in Central Nepal

    Science.gov (United States)

    Marahatta, S.; Adhikari, L.; Pokharel, B.

    2017-12-01

    Nepal is ranked the fourth most climate-vulnerable country in the world and it is prone to different weather-related hazards including droughts, floods, and landslides [Wang et al., 2013; Gillies et al., 2013]. Although extremely vulnerable to extreme weather events, there are no extreme weather warning system established to inform public in Nepal. Nepal has witnessed frequent drought and flood events, however, the extreme precipitation that occurred on 19-20 July 1993 created a devastating flood and landslide making it the worst weather disaster in the history of Nepal. During the second week of July, Nepal and northern India experienced abnormal dry condition due to the shifting of the monsoon trough to central India. The dry weather changed to wet when monsoon trough moved northward towards foothills of the Himalayas. Around the same period, a low pressure center was located over the south-central Nepal. The surface low was supported by the mid-, upper-level shortwave and cyclonic vorticity. A meso-scale convective system created record breaking one day rainfall (540 mm) in the region. The torrential rain impacted the major hydropower reservoir, Bagmati barrage in Karmaiya and triggered many landslides and flash floods. The region had the largest hydropower (Kulekhani hydropower, 92 MW) of the country at that time and the storm event deposited extremely large amount of sediments that reduced one-fourth (4.8 million m3) of reservoir dead storage (12 million m3). The 1-in-1000 years flood damaged the newly constructed barrage and took more than 700 lives. Major highways were damaged cutting off supply of daily needed goods, including food and gas, in the capital city, Kathmandu, for more than a month. In this presentation, the meteorological conditions of the extreme event will be diagnosed and the impact of the sedimentation due to the flood on Kulekhani reservoir and hydropower generation will be discussed.

  3. Cascading Events, Technology and the Floods Directive: future challenges

    Directory of Open Access Journals (Sweden)

    Pescaroli Gianluca

    2016-01-01

    Full Text Available Cascading events can be referred to multidimensional disasters, where a primary trigger generates a nonlinear series of secondary emergencies that escalate in time, becoming eventually the priority to tackle. In this process, critical infrastructure can be handled as roots of vulnerabilities, because they accumulate both physical attributes and functional nodes. When compromised, they produce widespread breakdowns of society, but also orient emergency responses and long-term recovery. Although floods have been widely associated to the failure of vulnerable equipments or to the disruption of strategic sectors such as energy, communication and transportation, their integration with the emerging concept of cascading has been limited. This open topic presents many challenges for scholars, researchers and practitioners, in particular when the implementation of the EU Floods Directive is considered. The paper presents an overview of the Floods Directive and its relation with the cascading events, using case studies and examples from the existing literature to point out missing links and gaps in the legislation. Conclusions argue that the Directive considers only local geographical scales and limited temporal horizons, which can be result inadequate to limit the escalation of events.

  4. Impact of Flooding on Traffic Route Choices

    Directory of Open Access Journals (Sweden)

    Othman M.H.

    2014-01-01

    Full Text Available Traffic route choice using road network modelling can play a key role in preventing and minimizing traffic problems during disasters. Using road network modelling, real road conditions during flooding are simulated in order to produce a response plan for road users to evacuate based on the roads' real risks and situation. Using a Geographical Information System (GIS we can forecast and provide road users with available alternatives when certain access roads or links need to be closed due to catastrophic hazards such as floods. This study focuses on floods as it is the most common form of natural disaster occurring in Malaysia, and due to the fact that the chance and risk of a flood occurring cannot be accurately predicted nor measured. Therefore, as a response to this problem, the outcome of this study is highly useful for the retrieval of information on flooded roads and the impacts on road users. Using GIS's capability to display both spatial and attributive information, we have provided an attractive alternative to conventional methods in order to show available traffic route choices and a transportation network plan.

  5. A Synoptic Climatology of Combined Severe/Weather/Flash Flood Events

    Science.gov (United States)

    Pallozzi, Kyle J.

    Classical forms of severe weather such as tornadoes, damaging convective wind gusts, and large hail, as well as flash flooding events, all have potentially large societal impacts. This impact is further magnified when these hazards occur simultaneously in time and space. A major challenge for operational forecasters is how to accurately predict the occurrence of combined storm hazards, and how to communicate the associated multiple threat hazards to the public. A seven-year climatology (2009-2015) of combined severe weather/flash flooding (SVR/FF) events across the contiguous United States was developed in attempt to study the combined SVR/FF event hazards further. A total of 211 total cases were identified and sub-divided into seven subcategories based on their convective morphology and meteorological characteristics. Heatmaps of event report frequency were created to extract spatial, seasonal and interannual patterns in SVR/FF event activity. Diurnal trends were examined from time series plots of tornado, hail, wind and flash flood/flood reports. Event-centered composites of environmental variables were created for each subcategory from 13 km RUC/RAP analyses. Representative cases studies were conducted for each subcategory. A "ring of fire" with the highest levels of SVR/FF event activity was noted across the central United States. SVR/FF events were least common in the Southeast, High Plains, and Northern Plains. Enhanced SVR/FF activity reflected contributions from synoptic events during the cool and shoulder seasons over the Lower Mississippi, Arkansas and Tennessee Valleys, and MCS activity during the warm season over the lower Great Plains, and the Upper Mississippi, Missouri and Ohio River Valleys. Results from the composite analyses indicated that relatively high values of CAPE, surface-500 hPa shear and precipitable water were observed for all subcategories. Case studies show that many high-end SVR/FF events featured slow-moving, or quasi

  6. Reproducing an extreme flood with uncertain post-event information

    Directory of Open Access Journals (Sweden)

    D. Fuentes-Andino

    2017-07-01

    Full Text Available Studies for the prevention and mitigation of floods require information on discharge and extent of inundation, commonly unavailable or uncertain, especially during extreme events. This study was initiated by the devastating flood in Tegucigalpa, the capital of Honduras, when Hurricane Mitch struck the city. In this study we hypothesized that it is possible to estimate, in a trustworthy way considering large data uncertainties, this extreme 1998 flood discharge and the extent of the inundations that followed from a combination of models and post-event measured data. Post-event data collected in 2000 and 2001 were used to estimate discharge peaks, times of peak, and high-water marks. These data were used in combination with rain data from two gauges to drive and constrain a combination of well-known modelling tools: TOPMODEL, Muskingum–Cunge–Todini routing, and the LISFLOOD-FP hydraulic model. Simulations were performed within the generalized likelihood uncertainty estimation (GLUE uncertainty-analysis framework. The model combination predicted peak discharge, times of peaks, and more than 90 % of the observed high-water marks within the uncertainty bounds of the evaluation data. This allowed an inundation likelihood map to be produced. Observed high-water marks could not be reproduced at a few locations on the floodplain. Identifications of these locations are useful to improve model set-up, model structure, or post-event data-estimation methods. Rainfall data were of central importance in simulating the times of peak and results would be improved by a better spatial assessment of rainfall, e.g. from radar data or a denser rain-gauge network. Our study demonstrated that it was possible, considering the uncertainty in the post-event data, to reasonably reproduce the extreme Mitch flood in Tegucigalpa in spite of no hydrometric gauging during the event. The method proposed here can be part of a Bayesian framework in which more events

  7. Derived flood frequency distributions considering individual event hydrograph shapes

    Science.gov (United States)

    Hassini, Sonia; Guo, Yiping

    2017-04-01

    Derived in this paper is the frequency distribution of the peak discharge rate of a random runoff event from a small urban catchment. The derivation follows the derived probability distribution procedure and incorporates a catchment rainfall-runoff model with approximating shapes for individual runoff event hydrographs. In the past, only simple triangular runoff event hydrograph shapes were used, in this study approximating runoff event hydrograph shapes better representing all the possibilities are considered. The resulting closed-form mathematical equations are converted to the commonly required flood frequency distributions for use in urban stormwater management studies. The analytically determined peak discharge rates of different return periods for a wide range of hypothetical catchment conditions were compared to those determined from design storm modeling. The newly derived equations generated results that are closer to those from design storm modeling and provide a better alternative for use in urban stormwater management studies.

  8. Modelling the interaction between flooding events and economic growth

    Directory of Open Access Journals (Sweden)

    J. Grames

    2015-06-01

    Full Text Available Socio-hydrology describes the interaction between the socio-economy and water. Recent models analyze the interplay of community risk-coping culture, flooding damage and economic growth (Di Baldassarre et al., 2013; Viglione et al., 2014. These models descriptively explain the feedbacks between socio-economic development and natural disasters like floods. Contrary to these descriptive models, our approach develops an optimization model, where the intertemporal decision of an economic agent interacts with the hydrological system. In order to build this first economic growth model describing the interaction between the consumption and investment decisions of an economic agent and the occurrence of flooding events, we transform an existing descriptive stochastic model into an optimal deterministic model. The intermediate step is to formulate and simulate a descriptive deterministic model. We develop a periodic water function to approximate the former discrete stochastic time series of rainfall events. Due to the non-autonomous exogenous periodic rainfall function the long-term path of consumption and investment will be periodic.

  9. Developing a Global Database of Historic Flood Events to Support Machine Learning Flood Prediction in Google Earth Engine

    Science.gov (United States)

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

    2016-12-01

    There is an increasing need to understand flood vulnerability as the societal and economic effects of flooding increases. Risk models from insurance companies and flood models from hydrologists must be calibrated based on flood observations in order to make future predictions that can improve planning and help societies reduce future disasters. Specifically, to improve these models both traditional methods of flood prediction from physically based models as well as data-driven techniques, such as machine learning, require spatial flood observation to validate model outputs and quantify uncertainty. A key dataset that is missing for flood model validation is a global historical geo-database of flood event extents. Currently, the most advanced database of historical flood extent is hosted and maintained at the Dartmouth Flood Observatory (DFO) that has catalogued 4320 floods (1985-2015) but has only mapped 5% of these floods. We are addressing this data gap by mapping the inventory of floods in the DFO database to create a first-of- its-kind, comprehensive, global and historical geospatial database of flood events. To do so, we combine water detection algorithms on MODIS and Landsat 5,7 and 8 imagery in Google Earth Engine to map discrete flood events. The created database will be available in the Earth Engine Catalogue for download by country, region, or time period. This dataset can be leveraged for new data-driven hydrologic modeling using machine learning algorithms in Earth Engine's highly parallelized computing environment, and we will show examples for New York and Senegal.

  10. Climate Change Impacts on Flooding in Southeastern Austria

    Science.gov (United States)

    Switanek, Matt; Truhetz, Heimo; Reszler, Christian

    2015-04-01

    Floods in southeastern Austria can cause significant damage to life, property and infrastructure. These flood events are often the result of extreme precipitation from small-scale convective storms. In order to more accurately model the changes to flood magnitude and frequency, Regional Climate Models (RCMs) must be able to simulate small-scale convective storms similar to those that have been observed. Even as computational resources have increased, RCMs are just now achieving the high spatial and temporal scales necessary to physically resolve the processes that govern small-scale convection. With increased resolution, RCMs can rely on their internal physics to model convective precipitation and need not depend on parameterization. This study uses historical and future scenarios of Regional Climate Models (RCMs) run at a spatial scale of 3 km and temporal scale of 1 hr. In order to subsequently force a hydrological flood model, the sub-daily precipitation and temperature data from the RCMs are first bias corrected. A newly proposed bias correction method is presented and compared to the commonly used quantile mapping. The proposed bias correction method performs better in its ability to preserve the model projected climate change signal (measured by changes in mean and variance). Lastly, the changes in the quantity and frequency of projected extreme precipitation, at the watershed level, are analyzed with respect to the historic time period. With these improvements in dynamical modeling and bias correction methods, a clearer picture emerges revealing the more likely impacts climate change will have on floods in southeastern Austria.

  11. Examining the effects of urban agglomeration polders on flood events in Qinhuai River basin, China with HEC-HMS model.

    Science.gov (United States)

    Gao, Yuqin; Yuan, Yu; Wang, Huaizhi; Schmidt, Arthur R; Wang, Kexuan; Ye, Liu

    2017-05-01

    The urban agglomeration polders type of flood control pattern is a general flood control pattern in the eastern plain area and some of the secondary river basins in China. A HEC-HMS model of Qinhuai River basin based on the flood control pattern was established for simulating basin runoff, examining the impact of urban agglomeration polders on flood events, and estimating the effects of urbanization on hydrological processes of the urban agglomeration polders in Qinhuai River basin. The results indicate that the urban agglomeration polders could increase the peak flow and flood volume. The smaller the scale of the flood, the more significant the influence of the polder was to the flood volume. The distribution of the city circle polder has no obvious impact on the flood volume, but has effect on the peak flow. The closer the polder is to basin output, the smaller the influence it has on peak flows. As the level of urbanization gradually improving of city circle polder, flood volumes and peak flows gradually increase compared to those with the current level of urbanization (the impervious rate was 20%). The potential change in flood volume and peak flow with increasing impervious rate shows a linear relationship.

  12. Impacts of human behavior heterogeneity on the benefits of probabilistic flood warnings

    Science.gov (United States)

    Du, E.; Rivera, S. J.; Cai, X.; Minsker, B. S.; Ernest, A. N. S.; Myers, L.

    2016-12-01

    Flood predictions and warnings are intended to reduce flood-related property damages and loss of human life. Considerable research has improved flood forecasting accuracy (e.g., more accurate prediction of the occurrence of flood events) and lead time. However, the delivery of improved forecast information alone is not necessarily sufficient for mitigating flooding damage, as people have varying responses and reactions after receiving flood warnings. This study develops an agent-based modeling framework that considers human behavioral heterogeneity and residential density in flood warning-response systems. The framework is coupled with a traffic model to simulate evacuation processes within a road network under various flood-warning scenarios. The results show that the marginal benefit associated with providing better flood warnings (i.e., flood warnings with high prediction accuracies and/or longer lead times) is significantly constrained if people behave in a more risk-tolerant manner, especially in high-density residential areas. The results also show significant impacts of human behavior heterogeneity on the benefit of flood warnings, and thus highlight the importance of considering human behavior heterogeneity in simulating flood warning-response systems. Further study is suggested to more accurately model human responses and behavior heterogeneity, as well as to include more attributes of residential areas to estimate the benefit of flood warnings.

  13. FloodProBE: technologies for improved safety of the built environment in relation to flood events

    International Nuclear Information System (INIS)

    Ree, C.C.D.F. van; Van, M.A.; Heilemann, K.; Morris, M.W.; Royet, P.; Zevenbergen, C.

    2011-01-01

    The FloodProBE project started as a FP7 research project in November 2009. Floods, together with wind related storms, are considered the major natural hazard in the EU in terms of risk to people and assets. In order to adapt urban areas (in river and coastal zones) to prevent flooding or to be better prepared for floods, decision makers need to determine how to upgrade flood defences and increasing flood resilience of protected buildings and critical infrastructure (power supplies, communications, water, transport, etc.) and assess the expected risk reduction from these measures. The aim of the FloodProBE-project is to improve knowledge on flood resilience and flood protection performance for balancing investments in flood risk management in urban areas. To this end, technologies, methods and tools for assessment purposes and for the adaptation of new and existing buildings and critical infrastructure are developed, tested and disseminated. Three priority areas are addressed by FloodProBE. These are: (i) vulnerability of critical infrastructure and high-density value assets including direct and indirect damage, (ii) the assessment and reliability of urban flood defences including the use of geophysical methods and remote sensing techniques and (iii) concepts and technologies for upgrading weak links in flood defences as well as construction technologies for flood proofing buildings and infrastructure networks to increase the flood resilience of the urban system. The primary impact of FloodProBE in advancing knowledge in these areas is an increase in the cost-effectiveness (i.e. performance) of new and existing flood protection structures and flood resilience measures.

  14. The flood event that affected Badajoz in November 1997

    Directory of Open Access Journals (Sweden)

    P. Lorente

    2008-04-01

    Full Text Available The flooding episode of November 1997 in Badajoz was one of the most dramatic catastrophes in Spain: as a result, there were 21 fatalities and huge financial damages. The main purpose of this work is to assess the prevailing synoptic conditions as well as detailing the mesoscale effects by means of moisture sources and dynamic and thermodynamic instability analysis involved in the November 1997 Spanish severe weather episode. In order to achieve the above, this flood event is described in terms of moisture content evolution by means of individual particle simulation along 3-day back-trajectories. A Lagrangian model is applied in order to characterize the atmospheric particles involved in the focused case (localization, height and specific humidity which give rise to sudden precipitation stream. Geopotential height and temperature fields were used to describe the synoptic situation. Thermodynamic indices, such as CAPE, SWEAT and KI, and dynamic parameters like potential vorticity anomaly at 330 K isentropic surface and Q vector divergence were also calculated in order to complete the analysis and to give a thorough weather frame taking into account the atmospheric instability. The results of this work suggest this flood event was due mainly to strong dynamic instability along with large amounts of moisture advected by a trough, while the thermodynamic instability played a secondary role. Finally, a new methodology based on a technique proposed by Tremblay (2005 has been developed in order to separate the precipitation into stratiform and convective components. It is evident that the event was associated with a predominant convective regime.

  15. Adaptation to climate change: Using nighttime lights satellite data to explore human response to flood events

    Science.gov (United States)

    Mård, Johanna; Di Baldassarre, Giuliano

    2017-04-01

    To better understand the impact of climate change, we need to uncover how (and to what extent) societies respond and adapt to it. Yet the dynamics resulting from two-way feedbacks between nature and society remain largely unknown. Here we present an interdisciplinary study aiming to uncover one of the least quantified aspects of human-nature interactions, the spatial-temporal distribution of demographic changes following the occurrence of extreme events. To this end, we use nighttime light satellite data in four contrasting case studies in both low- and high-income countries (Lower Limpopo River in Mozambique, Mekong River in Vietnam and Cambodia, Brisbane River in Australia and Mississippi River at St. Louis in USA), and explore the interplay between flooding events and changes in population distribution in the period 1992-2013. Our study shows the challenges and opportunities of nighttime lights in unraveling the way humans adapt to climate change. Specific results show that population distribution of societies that strongly rely on structural measures ("fighting floods" policies) is not significantly affected by the occurrence of flood events. Conversely, learning dynamics emerge in societies that mainly rely on non-structural measures ("living with floods" policies) in terms of relative population in floodplain areas, i.e. reduced human proximity to rivers. Lastly, we propose the development of a novel approach to exploit the growing availability of worldwide information, such as nighttime lights satellite data, to uncover human adaptation to climate change across scales and along gradients of social and natural conditions.

  16. Error Analysis of Satellite Precipitation-Driven Modeling of Flood Events in Complex Alpine Terrain

    Directory of Open Access Journals (Sweden)

    Yiwen Mei

    2016-03-01

    Full Text Available The error in satellite precipitation-driven complex terrain flood simulations is characterized in this study for eight different global satellite products and 128 flood events over the Eastern Italian Alps. The flood events are grouped according to two flood types: rain floods and flash floods. The satellite precipitation products and runoff simulations are evaluated based on systematic and random error metrics applied on the matched event pairs and basin-scale event properties (i.e., rainfall and runoff cumulative depth and time series shape. Overall, error characteristics exhibit dependency on the flood type. Generally, timing of the event precipitation mass center and dispersion of the time series derived from satellite precipitation exhibits good agreement with the reference; the cumulative depth is mostly underestimated. The study shows a dampening effect in both systematic and random error components of the satellite-driven hydrograph relative to the satellite-retrieved hyetograph. The systematic error in shape of the time series shows a significant dampening effect. The random error dampening effect is less pronounced for the flash flood events and the rain flood events with a high runoff coefficient. This event-based analysis of the satellite precipitation error propagation in flood modeling sheds light on the application of satellite precipitation in mountain flood hydrology.

  17. Climate and change: simulating flooding impacts on urban transport network

    Science.gov (United States)

    Pregnolato, Maria; Ford, Alistair; Dawson, Richard

    2015-04-01

    National-scale climate projections indicate that in the future there will be hotter and drier summers, warmer and wetter winters, together with rising sea levels. The frequency of extreme weather events is expected to increase, causing severe damage to the built environment and disruption of infrastructures (Dawson, 2007), whilst population growth and changed demographics are placing new demands on urban infrastructure. It is therefore essential to ensure infrastructure networks are robust to these changes. This research addresses these challenges by focussing on the development of probabilistic tools for managing risk by modelling urban transport networks within the context of extreme weather events. This paper presents a methodology to investigate the impacts of extreme weather events on urban environment, in particular infrastructure networks, through a combination of climate simulations and spatial representations. By overlaying spatial data on hazard thresholds from a flood model and a flood safety function, mitigated by potential adaptation strategies, different levels of disruption to commuting journeys on road networks are evaluated. The method follows the Catastrophe Modelling approach and it consists of a spatial model, combining deterministic loss models and probabilistic risk assessment techniques. It can be applied to present conditions as well as future uncertain scenarios, allowing the examination of the impacts alongside socio-economic and climate changes. The hazard is determined by simulating free surface water flooding, with the software CityCAT (Glenis et al., 2013). The outputs are overlapped to the spatial locations of a simple network model in GIS, which uses journey-to-work (JTW) observations, supplemented with speed and capacity information. To calculate the disruptive effect of flooding on transport networks, a function relating water depth to safe driving car speed has been developed by combining data from experimental reports (Morris et

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

    Science.gov (United States)

    Ahamed, Aakash; Bolten, John; Doyle, C.; Fayne, Jessica

    2016-01-01

    Floods are the costliest natural disaster (United Nations 2004), causing approximately6.8 million deaths in the twentieth century alone (Doocy et al. 2013).Worldwide economic flood damage estimates in 2012 exceed $19 Billion USD(Munich Re 2013). Extended duration floods also pose longer term threats to food security, water, sanitation, hygiene, and community livelihoods, particularly in developing countries (Davies et al. 2014).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 (IPCC 2007). 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 assessflooding and extend analytical methods to estimate impacted population and infrastructure.

  19. Assimilation of flood extent data with 2D flood inundation models for localised intense rainfall events

    Science.gov (United States)

    Neal, J. C.; Wood, M.; Bermúdez, M.; Hostache, R.; Freer, J. E.; Bates, P. D.; Coxon, G.

    2017-12-01

    Remote sensing of flood inundation extent has long been a potential source of data for constraining and correcting simulations of floodplain inundation. Hydrodynamic models and the computing resources to run them have developed to the extent that simulation of flood inundation in two-dimensional space is now feasible over large river basins in near real-time. However, despite substantial evidence that there is useful information content within inundation extent data, even from low resolution SAR such as that gathered by Envisat ASAR in wide swath mode, making use of the information in a data assimilation system has proved difficult. He we review recent applications of the Ensemble Kalman Filter (EnKF) and Particle Filter for assimilating SAR data, with a focus on the River Severn UK and compare these with complementary research that has looked at the internal error sources and boundary condition errors using detailed terrestrial data that is not available in most locations. Previous applications of the EnKF to this reach have focused on upstream boundary conditions as the source of flow error, however this description of errors was too simplistic for the simulation of summer flood events where localised intense rainfall can be substantial. Therefore, we evaluate the introduction of uncertain lateral inflows to the ensemble. A further limitation of the existing EnKF based methods is the need to convert flood extent to water surface elevations by intersecting the shoreline location with a high quality digital elevation model (e.g. LiDAR). To simplify this data processing step, we evaluate a method to directly assimilate inundation extent as a EnKF model state rather than assimilating water heights, potentially allowing the scheme to be used where high-quality terrain data are sparse.

  20. Impacts of dyke development in flood prone areas in the Vietnamese Mekong Delta to downstream flood hazard

    Science.gov (United States)

    Khanh Triet Nguyen, Van; Dung Nguyen, Viet; Fujii, Hideto; Kummu, Matti; Merz, Bruno; Apel, Heiko

    2017-04-01

    help of a quasi-2D hydrodynamic flood inundation model, using the latest comprehensive dyke survey and topographical data for the VMD. Changes in delta inundation dynamics with-/without- high-dyke systems were investigated in two different model setups, simulating the two recent most severe flood events in 2000 and 2011 with their original dike system as reference, and interchanged dyke system in order to quantify the induced hydraulic changes. In a similar manner the specific influence of the upper boundary, i.e. the flood characteristics of the two events, and the lower boundary, i.e. the tidal influence, on the water levels in the VMD was quantified and compared to the influence of the dyke system. Results of the trend test revealed negative but low significant trends at Chau Doc (p ≥ 0.1) and Tan Chau (p ≥ 0.05) at the upper part of the delta within the studied period. On the contrary, strong increasing and highly significant trends were detected at Can Tho and My Thuan downstream of fully flood protection areas, with a step change around the year 2000 (p Vietnam and Cambodia. Thus the claims that the dyke development has altered the water levels during floods in the areas downstream can be confirmed, but it has to be noted that the lower boundary, i.e. higher sea levels caused by sea level rise in combination with the widely observed land subsidence have an even larger impact. Based on these results, it is recommended to develop flood risk management strategies that use the high dyke areas as retention areas in order to mitigate the flood hazard downstream, if large flood events are forecasted.

  1. Impacts of extreme flooding on riverbank filtration water quality.

    Science.gov (United States)

    Ascott, M J; Lapworth, D J; Gooddy, D C; Sage, R C; Karapanos, I

    2016-06-01

    Riverbank filtration schemes form a significant component of public water treatment processes on a global level. Understanding the resilience and water quality recovery of these systems following severe flooding is critical for effective water resources management under potential future climate change. This paper assesses the impact of floodplain inundation on the water quality of a shallow aquifer riverbank filtration system and how water quality recovers following an extreme (1 in 17 year, duration >70 days, 7 day inundation) flood event. During the inundation event, riverbank filtrate water quality is dominated by rapid direct recharge and floodwater infiltration (high fraction of surface water, dissolved organic carbon (DOC) >140% baseline values, >1 log increase in micro-organic contaminants, microbial detects and turbidity, low specific electrical conductivity (SEC) 400% baseline). A rapid recovery is observed in water quality with most floodwater impacts only observed for 2-3 weeks after the flooding event and a return to normal groundwater conditions within 6 weeks (lower fraction of surface water, higher SEC, lower DOC, organic and microbial detects, DO). Recovery rates are constrained by the hydrogeological site setting, the abstraction regime and the water quality trends at site boundary conditions. In this case, increased abstraction rates and a high transmissivity aquifer facilitate rapid water quality recoveries, with longer term trends controlled by background river and groundwater qualities. Temporary reductions in abstraction rates appear to slow water quality recoveries. Flexible operating regimes such as the one implemented at this study site are likely to be required if shallow aquifer riverbank filtration systems are to be resilient to future inundation events. Development of a conceptual understanding of hydrochemical boundaries and site hydrogeology through monitoring is required to assess the suitability of a prospective riverbank filtration

  2. Application of a Coupled WRF-Hydro Model for Extreme Flood Events in the Mediterranean Basins

    Science.gov (United States)

    Fredj, Erick; Givati, Amir

    2015-04-01

    More accurate simulation of precipitation and streamflow is a challenge that can be addressed by using the Weather Research and Forecasting Model (WRF) in conjunction with the hydrological model coupling extension package (WRF-Hydro).This is demonstrated for the country of Israel and surrounding regions. Simulations from the coupled WRF/WRF-Hydro system were verified against measurements from rain gauges and hydrometric stations in the domain for the 2012-2013 and 2013-2014 winters (wet seasons). These periods were characterized by many punctuated hydrometeorological and hydroclimatic events, including both severe drought and extreme floods events. The WRF model simulations were initialized with 0.5 degree NOAA/NCEP GFS model data. The model domain was set up with 3 domains, up to 3km grid spacing resolution. The model configuration used here constitutes a fully distributed, 3-dimensional, variably-saturated surface and subsurface flow model. Application of terrain routing and, subsequently, channel and reservoir routing functions, to the uni-dimensional NOAA land surface model was motivated by the need to account for increased complexity in land surface states and fluxes and to provide a more physically-realistic conceptualization of terrestrial hydrologic processes. The simulation results indicated a good agreement with actual peak discharges for extreme flood events and for full hydrographs. Specifically the coupled WRF/WRF-Hydro model as configured in this study shows improvement in simulated precipitation over one way WRF precipitation simulations. The correlation between the observed and the simulated precipitation using the fully coupled WRF/WRF-Hydro system was higher than the standalone WRF model, especially for convective precipitation events that affect arid regions in the domain. The results suggest that the coupled WRF/WRF-Hydro system has potential for flood forecasting and flood warning purposes at 0-72 hour lead times for large cool season storm

  3. Early chemical and ecotoxicological responses of the Varano lagoon (SE Italy) to a flood event.

    Science.gov (United States)

    Fabbrocini, Adele; Cassin, Daniele; Santucci, Angela; Scirocco, Tommaso; Specchiulli, Antonietta; D'Adamo, Raffaele

    2017-10-01

    The effects on coastal lagoons of floods resulting from intense rainfall need to be assessed using a multidisciplinary approach, able to describe in real time the occurrence of changes in sediment quality, anticipating risk situations. In the present study the effectiveness as pre-screening tool of the MOT-test, an innovative bioassay that uses sperm motility as endpoint, has been evaluated; its response has been compared with the sediment chemical characterization, in order to determine the effects of a flood event occurred in the Varano lagoon, a poorly anthropized Mediterranean coastal lagoon. The MOT-test effect percentages ranged from 10% to 30%, fully reflecting data from chemical analyses. Organic pollutants showed concentrations always below the critical levels. The highest metal values were found in the south-eastern area; however, only for few metals (mainly Cd), and in few sites, they reached the limits defined by the sediment quality guidelines; consistently, these sites are located in the area where a higher stressors' impact was expected and the highest MOT-test effect percentages were recorded. In conclusion, even if results exclude the occurrence of serious contamination events as a consequence of the flood, the runoff resulting from the intense rainfall event has caused a pollutant load in the lagoon, consistent with the localization of the main anthropogenic activities in the catchment area. Moreover, preliminary data indicate the validity of the approach adopted for the post-flood quality assessment, proving the usefulness of the MOT-test as early-screening tool in the case of extreme events. Copyright © 2017. Published by Elsevier Inc.

  4. A study of the climate change impacts on fluvial flood propagation in the Vietnamese Mekong Delta

    Science.gov (United States)

    Van, P. D. T.; Popescu, I.; van Griensven, A.; Solomatine, D. P.; Trung, N. H.; Green, A.

    2012-12-01

    The present paper investigated the extent of the flood propagation in the Vietnamese Mekong Delta under different projected flood hydrographs, considering the 2000 flood event (the 20-yr return period event, T. V. H. Le et al., 2007) as the basis for computation. The analysis herein was done to demonstrate the particular complexity of the flood dynamics, which was simulated by the 1-D modelling system ISIS used by the Mekong River Commission. The floods of the year 2050 are simulated using a projected sea level rise of +30 cm. The future flood hydrograph changes at Kratie, Cambodia, were also applied for the upstream boundary condition by using an adjusted regional climate model. Two future flood hydrographs were applied at the upstream part of the delta, the first one in a scenario of climate change without considering developments in the Mekong Basin,and the second one in a scenario of climate change taking into account future development of the delta. Analyses were done to identify the areas sensitive to floods, considering the uncertainty of the projection of both the upstream and downstream boundary conditions. In addition, due to the rice-dominated culture in the Vietnamese Mekong Delta, possible impacts of floods on the rice-based farming systems were also analysed.

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

    Science.gov (United States)

    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

  6. AP1000{sup R} design robustness against extreme external events - Seismic, flooding, and aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Pfister, A.; Goossen, C.; Coogler, K.; Gorgemans, J. [Westinghouse Electric Company LLC, 1000 Westinghouse Drive, Cranberry Township, PA 16066 (United States)

    2012-07-01

    Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000{sup R} nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel

  7. AP1000R design robustness against extreme external events - Seismic, flooding, and aircraft crash

    International Nuclear Information System (INIS)

    Pfister, A.; Goossen, C.; Coogler, K.; Gorgemans, J.

    2012-01-01

    Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000 R nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel containment vessel which is

  8. Extreme flood events in the Bolivian Amazon wetlands

    Directory of Open Access Journals (Sweden)

    A. Ovando

    2016-03-01

    New hydrological insights for the region: The results showed that large floods are the result of the superimposition of flood waves from major sub-basins of the region. As a previous study suggested, the dynamics of the floods are controlled by an exogenous process, created by the flood wave originating in the Andes piedmont that travels through the Mamoré River; and by an endogenous process, which is the runoff originating in the Llanos. Our study showed that the first process is evident only at the initial phase of the floods, and although important for attenuating the rising flood wave, it is of lesser importance compared to the endogenous process. We conclude that the endogenous process controls the magnitude and duration of major floods.

  9. Flood risk trends in coastal watersheds in South Spain: direct and indirect impact of river regulation

    Directory of Open Access Journals (Sweden)

    M. Egüen

    2015-06-01

    Full Text Available Spain is one of the world's countries with a large number of reservoirs per inhabitant. This intense regulation of the fluvial network during the 20th century has resulted in a decrease in flood events, a higher availability of water resources, and a high development of the irrigated crop area, even in the drier regions. For decades, flood perception was reduced since the development of reservoirs protected the floodplains of river; this resulted in later occupation of soil by urban, agricultural and industrial uses. In recent years, an increasing perception of flood events is observed, associated to the higher damage associated to extreme events in the now occupied areas, especially in coastal watersheds. This work shows the change on flood risk in the coastal areas of three hydrographic basins in Andalusia (South Spain during the reservoir expansion period: the Guadalete, Guadalquivir and Guadalhorce river basins. The results differentiate the impact of the regulation level on both the cumulative distribution functions of the fluvial discharge near the river mouth, for different time scales, and the associated damage related to the enhanced soil occupation during this period. The different impact on the final medium and long term flood risk is also assessed in terms of the storage capacity per unit area throughout the basins, the effective annual runoff/precipitation index, the frequency of sea storms, and the human factor (change in social perception of floods, for different intervals in the flood extreme regime. The implications for adaptation actions is also assessed.

  10. Flood risk trends in coastal watersheds in South Spain: direct and indirect impact of river regulation

    Science.gov (United States)

    Egüen, M.; Polo, M. J.; Gulliver, Z.; Contreras, E.; Aguilar, C.; Losada, M. A.

    2015-06-01

    Spain is one of the world's countries with a large number of reservoirs per inhabitant. This intense regulation of the fluvial network during the 20th century has resulted in a decrease in flood events, a higher availability of water resources, and a high development of the irrigated crop area, even in the drier regions. For decades, flood perception was reduced since the development of reservoirs protected the floodplains of river; this resulted in later occupation of soil by urban, agricultural and industrial uses. In recent years, an increasing perception of flood events is observed, associated to the higher damage associated to extreme events in the now occupied areas, especially in coastal watersheds. This work shows the change on flood risk in the coastal areas of three hydrographic basins in Andalusia (South Spain) during the reservoir expansion period: the Guadalete, Guadalquivir and Guadalhorce river basins. The results differentiate the impact of the regulation level on both the cumulative distribution functions of the fluvial discharge near the river mouth, for different time scales, and the associated damage related to the enhanced soil occupation during this period. The different impact on the final medium and long term flood risk is also assessed in terms of the storage capacity per unit area throughout the basins, the effective annual runoff/precipitation index, the frequency of sea storms, and the human factor (change in social perception of floods), for different intervals in the flood extreme regime. The implications for adaptation actions is also assessed.

  11. Impacts of dyke development in flood prone areas in the Vietnamese Mekong Delta to downstream flood hazard

    Science.gov (United States)

    Khanh Triet Nguyen, Van; Dung Nguyen, Viet; Fujii, Hideto; Kummu, Matti; Merz, Bruno; Apel, Heiko

    2016-04-01

    The Vietnamese Mekong Delta (VMD) plays an important role in food security and socio-economic development of the country. Being a low-lying coastal region, the VMD is particularly susceptible to both riverine and tidal floods, which provide, on (the) one hand, the basis for the rich agricultural production and the livelihood of the people, but on the other hand pose a considerable hazard depending on the severity of the floods. But despite of potentially hazardous flood, the area remain active as a rice granary due to its nutrient-rich soils and sediment input, and dense waterways, canals and the long standing experience of the population living with floods. In response to both farmers' requests and governmental plans, the construction of flood protection infrastructure in the delta progressed rapidly in the last twenty years, notably at areas prone to deep flooding, i.e. the Plain of Reeds (PoR) and Long Xuyen Quadrangle (LXQ). Triple rice cropping becomes possible in farmlands enclosed by "full-dykes", i.e. dykes strong and high enough to prevent flooding of the flood plains for most of the floods. In these protected flood plains rice can be grown even during the peak flood period (September to November). However, little is known about the possibly (and already alleged) negative impacts of this fully flood protection measure to downstream areas. This study aims at quantifying how the flood regime in the lower part of the VMD (e.g. Can Tho, My Thuan, …) has been changed in the last 2 recent "big flood" events of 2000 and 2011 due to the construction of the full-dyke system in the upper part. First, an evaluation of 35 years of daily water level data was performed in order to detect trends at key gauging stations: Kratie: upper boundary of the Delta, Tan Chau and Chau Doc: areas with full-dyke construction, Can Tho and My Thuan: downstream. Results from the Mann-Kendall (MK) test show a decreasing trend of the annual maximum water level at 3 stations Kratie, Tan

  12. Significance of "high probability/low damage" versus "low probability/high damage" flood events

    Directory of Open Access Journals (Sweden)

    B. Merz

    2009-06-01

    Full Text Available The need for an efficient use of limited resources fosters the application of risk-oriented design in flood mitigation. Flood defence measures reduce future damage. Traditionally, this benefit is quantified via the expected annual damage. We analyse the contribution of "high probability/low damage" floods versus the contribution of "low probability/high damage" events to the expected annual damage. For three case studies, i.e. actual flood situations in flood-prone communities in Germany, it is shown that the expected annual damage is dominated by "high probability/low damage" events. Extreme events play a minor role, even though they cause high damage. Using typical values for flood frequency behaviour, flood plain morphology, distribution of assets and vulnerability, it is shown that this also holds for the general case of river floods in Germany. This result is compared to the significance of extreme events in the public perception. "Low probability/high damage" events are more important in the societal view than it is expressed by the expected annual damage. We conclude that the expected annual damage should be used with care since it is not in agreement with societal priorities. Further, risk aversion functions that penalise events with disastrous consequences are introduced in the appraisal of risk mitigation options. It is shown that risk aversion may have substantial implications for decision-making. Different flood mitigation decisions are probable, when risk aversion is taken into account.

  13. Bibliography of forest water yields, flooding issues, and the hydrologic modeling of extreme flood events

    Science.gov (United States)

    Mark H. Eisenbies; M.B. Adams; W. Michael Aust; James A. Burger

    2007-01-01

    Floods continue to cause significant damage in the United States and elsewhere, and questions about the causes of flooding continue to be debated. A significant amount of research has been conducted on the relationship between forest management activities and water yield, peak flows, and flooding; somewhat less research has been conducted on the modeling of these...

  14. Climate change impact on flood hazard

    Directory of Open Access Journals (Sweden)

    M. Brilly

    2014-09-01

    Full Text Available Climate changes have a high impact on river discharges and therefore on floods. There are a few different methods we can use to predict discharge changes in the future. In this paper we used the complex HBV model for the Vipava River and simple correlation between discharge and precipitation data for the Soča River. The discharge prediction is based on the E-OBS precipitation data for three future time periods (2011–2040, 2041–2070 and 2071–2100. Estimated discharges for those three future periods are presented for both rivers. But a special situation occurs at the confluence where the two rivers with rather different catchments unite, and this requires an additional probability analysis.

  15. Interpreting the impact of flood forecasts by combining policy analysis studies and flood defence

    Directory of Open Access Journals (Sweden)

    Slomp Robert

    2016-01-01

    Full Text Available Flood forecasting is necessary to save lives and reduce damages. Reducing damages is important to save livelihoods and to reduce the recovery time. Flood alerts should contain expected time of the event, location and extent of the event. A flood alert is not only one message but part of a rehearsed flow of information using multiple canals. First people have to accept the fact that there might be a threat and what the threat is about. People need a reference to understand the situation and be aware of possible measures they can take to assure their own safety and reduce damages. Information to the general public has to be consistent with the information used by emergency services and has to be very clear about consequences and context of possible measures (as shelter in place or preventive evacuation. Emergency services should monitor how the public is responding to adapt their communication en operation during a crisis. Flood warnings and emergency services are often coordinated by different government organisations. This is an extra handicap for having consistent information out on time for people to use. In an information based society, where everyone has twitter, email and a camera, public organisations may have to trust the public more and send out the correct information as it comes in. In the Netherlands Rijkswaterstaat, the National Water Authority and the National Public Works Department, is responsible for or involved in forecasting in case of floods, policy studies on flood risk, policy studies on maintenance, assessment and design of flood defences, elaborating rules and regulations for flood defences, advice on crisis management to the national government and for maintaining the main infrastructure in the Netherlands (high ways and water ways. The Water Management Center in the Netherlands (WMCN has developed a number of models to provide flood forecasts. WMCN is run for and by all managers of flood defences and is hosted by

  16. Hydrodynamic modelling of extreme flood events in the Kashmir valley in India

    Science.gov (United States)

    Jain, Manoj; Parvaze, Sabah

    2017-04-01

    Floods are one of the most predominant, costly and deadly hazards of all natural vulnerabilities. Every year, floods exert a heavy toll on human life and property in many parts of the world. The prediction of river stages and discharge during flood extremes plays a vital role in planning structural and non-structural measures of flood management. The predictions are also valuable to prepare the flood inundation maps and river floodplain zoning. In the Kashmir Valley, floods occur mainly and very often in the Jhelum Basin mostly due to extreme precipitation events and rugged mountainous topography of the basin. These floods cause extreme damage to life and property in the valley from time to time. Excessive rainfall, particularly in higher sub-catchments causes the snow to melt resulting in excessive runoff downhill to the streams causing floods in the Kashmir Valley where Srinagar city is located. However, very few hydrological studies have been undertaken for the Jhelum Basin mainly due to non-availability of hydrological data due to very complex mountainous terrain. Therefore, the present study has been conducted to model the extreme flood events in the Jhelum Basin in Kashmir Valley. An integrated NAM and MIKE 11 HD model has been setup for Jhelum basin up to Ram Munshi Bagh gauging site and then four most extreme historical flood events in the time series has been analyzed separately including the most recent and most extreme flood event of 2014. In September 2014, the Kashmir Valley witnessed the most severe flood in the past 60 years due to catastrophic rainfall from 1st to 6th September wherein the valley received unprecedented rainfall of more than 650 mm in just 3 days breaking record of many decades. The MIKE 11 HD and NAM model has been calibrated using 21 years (1985-2005) data and validated using 9 years (2006-2014) data. The efficiency indices of the model for calibration and validation period is 0.749 and 0.792 respectively. The model simulated

  17. Plant species richness and functional traits affect community stability after a flood event.

    Science.gov (United States)

    Fischer, Felícia M; Wright, Alexandra J; Eisenhauer, Nico; Ebeling, Anne; Roscher, Christiane; Wagg, Cameron; Weigelt, Alexandra; Weisser, Wolfgang W; Pillar, Valério D

    2016-05-19

    Climate change is expected to increase the frequency and magnitude of extreme weather events. It is therefore of major importance to identify the community attributes that confer stability in ecological communities during such events. In June 2013, a flood event affected a plant diversity experiment in Central Europe (Jena, Germany). We assessed the effects of plant species richness, functional diversity, flooding intensity and community means of functional traits on different measures of stability (resistance, resilience and raw biomass changes from pre-flood conditions). Surprisingly, plant species richness reduced community resistance in response to the flood. This was mostly because more diverse communities grew more immediately following the flood. Raw biomass increased over the previous year; this resulted in decreased absolute value measures of resistance. There was no clear response pattern for resilience. We found that functional traits drove these changes in raw biomass: communities with a high proportion of late-season, short-statured plants with dense, shallow roots and small leaves grew more following the flood. Late-growing species probably avoided the flood, whereas greater root length density might have allowed species to better access soil resources brought from the flood, thus growing more in the aftermath. We conclude that resource inputs following mild floods may favour the importance of traits related to resource acquisition and be less associated with flooding tolerance. © 2016 The Author(s).

  18. Social impact of the 2004 Manawatu floods and the 'hollowing out' of rural New Zealand.

    Science.gov (United States)

    Smith, Willie; Davies-Colley, Christian; Mackay, Alec; Bankoff, Greg

    2011-07-01

    The Manawatu floods of 2004 have had significant, long-lasting social consequences. This paper draws on findings from a series of detailed surveys of 39 farm households directly affected by the floods and 17 individuals directly involved in managing the flood recovery programme. The nature of the impact on rural families highlights how the 'hollowing out' of rural New Zealand has changed the capacity of rural communities to respond to natural hazards and increased their sense of isolation. In addition, the floods exposed the vulnerability of rural communities. This is shown to have implications for policies designed to build resilience and improve responses to adverse events, including the need to support local, community initiatives on self-reliance and mutual support. Approaches to manage better long-term flood risks should be designed within a context of ongoing rural decline that has compromised the health of both individuals and communities. © 2011 The Author(s). Disasters © Overseas Development Institute, 2011.

  19. Societal and economic impacts of flood hazards in Turkey – an overview

    Directory of Open Access Journals (Sweden)

    Koç Gamze

    2016-01-01

    Full Text Available Turkey has been severely affected by many natural hazards, in particular earthquakes and floods. Although there is a large body of literature on earthquake hazards and risks in Turkey, comparatively little is known about flood hazards and risks. Therefore, with this study it is aimed to investigate flood patterns, societal and economic impacts of flood hazards in Turkey, as well as providing a comparative overview of the temporal and spatial distribution of flood losses by analysing EM-DAT (Emergency Events Database and TABB (Turkey Disaster Data Base databases on disaster losses throughout Turkey for the years 1960-2014. The comparison of these two databases reveals big mismatches of the flood data, e.g. the reported number of events, number of affected people and economic loss, differ dramatically. With this paper, it has been explored reasons for mismatches. Biases and fallacies for loss data in the two databases has been discussed as well. Since loss data collection is gaining more and more attention, e.g. in the Sendai Framework for Disaster Risk Reduction 2015-2030 (SFDRR, the study could offer a base-work for developing guidelines and procedures on how to standardize loss databases and implement across the other hazard events, as well as substantial insights for flood risk mitigation and adaptation studies in Turkey and will offer valuable insights for other (European countries.

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

    Science.gov (United States)

    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.

  1. Radar rainfall estimation in the context of post-event analysis of flash-flood events

    Science.gov (United States)

    Delrieu, G.; Bouilloud, L.; Boudevillain, B.; Kirstetter, P.-E.; Borga, M.

    2009-09-01

    This communication is about a methodology for radar rainfall estimation in the context of post-event analysis of flash-flood events developed within the HYDRATE project. For such extreme events, some raingauge observations (operational, amateur) are available at the event time scale, while few raingauge time series are generally available at the hydrologic time steps. Radar data is therefore the only way to access to the rainfall space-time organization, but the quality of the radar data may be highly variable as a function of (1) the relative locations of the event and the radar(s) and (2) the radar operating protocol(s) and maintenance. A positive point: heavy rainfall is associated with convection implying better visibility and lesser bright band contamination compared with more current situations. In parallel with the development of a regionalized and adaptive radar data processing system (TRADHy; Delrieu et al. 2009), a pragmatic approach is proposed here to make best use of the available radar and raingauge data for a given flash-flood event by: (1) Identifying and removing residual ground clutter, (2) Applying the "hydrologic visibility" concept (Pellarin et al. 2002) to correct for range-dependent errors (screening and VPR effects for non-attenuating wavelengths, (3) Estimating an effective Z-R relationship through a radar-raingauge optimization approach to remove the mean field bias (Dinku et al. 2002) A sensitivity study, based on the high-quality volume radar datasets collected during two intense rainfall events of the Bollène 2002 experiment (Delrieu et al. 2009), is first proposed. Then the method is implemented for two other historical events occurred in France (Avène 1997 and Aude 1999) with datasets of lesser quality. References: Delrieu, G., B. Boudevillain, J. Nicol, B. Chapon, P.-E. Kirstetter, H. Andrieu, and D. Faure, 2009: Bollène 2002 experiment: radar rainfall estimation in the Cévennes-Vivarais region, France. Journal of Applied

  2. Economic impact of cultural events

    Directory of Open Access Journals (Sweden)

    M Saayman

    2004-11-01

    Full Text Available The phenomenon of events can hardly be described as a new one.  The aim of this paper is to determine the economic benefits of three major cultural events in South Africa to the host community.  Measuring the economic impact normally entails some estimation of the cash injection into a region by visitors and applying the relevant multiplier to arrive at a monetary estimate of the economic impact.  But few regions or municipal areas have detailed economic data to construct a type of input-output model and derive a multiplier.  The purpose of the methods used in this research were firstly to determine the estimated cash injection, secondly to estimate the size of leakages in the local economy and thirdly to derive an appropriate multiplier to estimate the economic impact of the event.

  3. Extensive spatio-temporal assessment of flood events by application of pair-copulas

    Directory of Open Access Journals (Sweden)

    M. Schulte

    2015-06-01

    Full Text Available Although the consequences of floods are strongly related to their peak discharges, a statistical classification of flood events that only depends on these peaks may not be sufficient for flood risk assessments. In many cases, the flood risk depends on a number of event characteristics. In case of an extreme flood, the whole river basin may be affected instead of a single watershed, and there will be superposition of peak discharges from adjoining catchments. These peaks differ in size and timing according to the spatial distribution of precipitation and watershed-specific processes of flood formation. Thus, the spatial characteristics of flood events should be considered as stochastic processes. Hence, there is a need for a multivariate statistical approach that represents the spatial interdependencies between floods from different watersheds and their coincidences. This paper addresses the question how these spatial interdependencies can be quantified. Each flood event is not only assessed with regard to its local conditions but also according to its spatio-temporal pattern within the river basin. In this paper we characterise the coincidence of floods by trivariate Joe-copula and pair-copulas. Their ability to link the marginal distributions of the variates while maintaining their dependence structure characterizes them as an adequate method. The results indicate that the trivariate copula model is able to represent the multivariate probabilities of the occurrence of simultaneous flood peaks well. It is suggested that the approach of this paper is very useful for the risk-based design of retention basins as it accounts for the complex spatio-temporal interactions of floods.

  4. Lava flooding of ancient planetary crusts: geometry, thickness, and volumes of flooded lunar impact basins

    International Nuclear Information System (INIS)

    Head, J.W.

    1982-01-01

    Estimates of lava volumes on planetary surfaces provide important data on the lava flooding history and thermal evolution of a planet. Lack of information concerning the configuration of the topography prior to volcanic flooding requires the use of a variety of techniques to estimate lava thicknesses and volumes. A technique is described and developed which provides volume estimates by artificially flooding unflooded lunar topography characteristic of certain geological environments, and tracking the area covered, lava thicknesses, and lava volumes. Comparisons of map patterns of incompletely buried topography in these artificially flooded areas are then made to lava-flooded topography on the Moon in order to estimate the actual lava volumes. This technique is applied to two areas related to lunar impact basins; the relatively unflooded Orientale basin, and the Archimedes-Apennine Bench region of the Imbrium basin. (Auth.)

  5. Flood menace in Kaduna Metropolis: impacts, remedial and ...

    African Journals Online (AJOL)

    This study assesses how Kaduna Metropolis have been affected by flood menace incidences as it takes a look at the devastating impacts, remedial and management strategies at curbing flooding in Kaduna Metropolis which has almost become a yearly occurrence. Data for this study were obtained from questionnaires, ...

  6. Impact of Flooding on Fishermen's families in Pedro Community ...

    African Journals Online (AJOL)

    Seventy-six percent of the respondents stated that flooding distorted the fishing business, destroyed fishing implements and impacted negatively on their social life. Flooding also interrupted children's schooling, increased environmental pollution, reduced fish catch and consequently family income and also increased the ...

  7. Calibration and validation of a small-scale urban surface water flood event using crowdsourced images

    Science.gov (United States)

    Green, Daniel; Yu, Dapeng; Pattison, Ian

    2017-04-01

    Surface water flooding occurs when intense precipitation events overwhelm the drainage capacity of an area and excess overland flow is unable to infiltrate into the ground or drain via natural or artificial drainage channels, such as river channels, manholes or SuDS. In the UK, over 3 million properties are at risk from surface water flooding alone, accounting for approximately one third of the UK's flood risk. The risk of surface water flooding is projected to increase due to several factors, including population increases, land-use alterations and future climatic changes in precipitation resulting in an increased magnitude and frequency of intense precipitation events. Numerical inundation modelling is a well-established method of investigating surface water flood risk, allowing the researcher to gain a detailed understanding of the depth, velocity, discharge and extent of actual or hypothetical flood scenarios over a wide range of spatial scales. However, numerical models require calibration of key hydrological and hydraulic parameters (e.g. infiltration, evapotranspiration, drainage rate, roughness) to ensure model outputs adequately represent the flood event being studied. Furthermore, validation data such as crowdsourced images or spatially-referenced flood depth collected during a flood event may provide a useful validation of inundation depth and extent for actual flood events. In this study, a simplified two-dimensional inertial based flood inundation model requiring minimal pre-processing of data (FloodMap-HydroInundation) was used to model a short-duration, intense rainfall event (27.8 mm in 15 minutes) that occurred over the Loughborough University campus on the 28th June 2012. High resolution (1m horizontal, +/- 15cm vertical) DEM data, rasterised Ordnance Survey topographic structures data and precipitation data recorded at the University weather station were used to conduct numerical modelling over the small (present during the flood event via the

  8. Fluxes of Heavy Metals from a Highly Polluted Watershed During Flood Events: A Case Study of the Litavka River, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Žák, Karel; Rohovec, Jan; Navrátil, Tomáš

    2009-01-01

    Roč. 203, 1/4 (2009), s. 343-358 ISSN 0049-6979 R&D Projects: GA AV ČR IAA300130505 Institutional research plan: CEZ:AV0Z30130516 Keywords : flood events * heavy metal contamination * Litavka River * Příbram ore region (Czech Republik) * flood events * heavy metal contamination * suspended particulate matter Subject RIV: DD - Geochemistry Impact factor: 1.676, year: 2009

  9. The flood of June 2013 in Germany: how much do we know about its impacts?

    Science.gov (United States)

    Thieken, Annegret H.; Bessel, Tina; Kienzler, Sarah; Kreibich, Heidi; Müller, Meike; Pisi, Sebastian; Schröter, Kai

    2016-07-01

    In June 2013, widespread flooding and consequent damage and losses occurred in Central Europe, especially in Germany. This paper explores what data are available to investigate the adverse impacts of the event, what kind of information can be retrieved from these data and how well data and information fulfil requirements that were recently proposed for disaster reporting on the European and international levels. In accordance with the European Floods Directive (2007/60/EC), impacts on human health, economic activities (and assets), cultural heritage and the environment are described on the national and sub-national scale. Information from governmental reports is complemented by communications on traffic disruptions and surveys of flood-affected residents and companies. Overall, the impacts of the flood event in 2013 were manifold. The study reveals that flood-affected residents suffered from a large range of impacts, among which mental health and supply problems were perceived more seriously than financial losses. The most frequent damage type among affected companies was business interruption. This demonstrates that the current scientific focus on direct (financial) damage is insufficient to describe the overall impacts and severity of flood events. The case further demonstrates that procedures and standards for impact data collection in Germany are widely missing. Present impact data in Germany are fragmentary, heterogeneous, incomplete and difficult to access. In order to fulfil, for example, the monitoring and reporting requirements of the Sendai Framework for Disaster Risk Reduction 2015-2030 that was adopted in March 2015 in Sendai, Japan, more efforts on impact data collection are needed.

  10. Detrital phosphorus as a proxy of flooding events in the Changjiang River Basin

    International Nuclear Information System (INIS)

    Meng, Jia; Yao, Peng; Bianchi, Thomas S.; Li, Dong; Zhao, Bin; Xu, Bochao; Yu, Zhigang

    2015-01-01

    In this study, sediment grain size (MGS), specific surface area (SSA), total organic carbon (TOC) contents, C/N molar ratios, stable carbon isotope, and P species in a sediment core, collected from the East China Sea (ECS) inner-shelf were measured to explore the applicability of detrital phosphorus (De-P) as a potential indicator of past flooding events in the Changjiang River Basin (CRB). In particular, we examined the linkages between the evolution of floods with regional climate changes and anthropogenic activities in the CRB. Peaks of De-P concentrations in sediments corresponded well with the worst flooding events of the CRB over the past two centuries (e.g., 1850s, 1860s, 1900s, 1920s, 1950s, 1980s, and 2000s). Moreover, De-P also corresponded well with the extreme hypoxic events in 1981 and 1998 in the Changjiang Estuary as indicated by Mo/Al ratios, indicating potential linkages between De-P as a flooding proxy to flood-induced hypoxia events in this region. In addition, a robust relationship was found among De-P, the floods in 1950s, 1980s, and 2000s of the CRB, the intensive El Niño-Southern Oscillation (ENSO), the abnormally weak East Asian Summer Monsoon (EASM) and the warm phase of Pacific Decadal Oscillation (PDO), suggesting that De-P also provided insights to linkages between regional climate change and flooding events in this region. - Highlights: • De-P was used to track past floods in the Changjiang River Basin (CRB). • De-P may serve as a proxy for flood-induced hypoxia events in the Changjiang Estuary. • De-P may be a proxy for examining linkages between floods and climatic drivers

  11. Impacts of flood on health: epidemiologic evidence from Hanoi, Vietnam

    Directory of Open Access Journals (Sweden)

    Debarati Guha-Sapir

    2011-08-01

    Full Text Available Vietnam is one of the most disaster-prone countries in the world. The country suffers from many kinds of natural disasters, of which the most common and serious one is flooding. Long and heavy rainfall during the last days of October and the first week of November 2008 resulted in a devastating flood unseen for over three decades in the capital city of Hanoi. It caused a substantial health impact on residents in and around the city and compromised the capacity of local health services. The aim of this study is to ascertain the vulnerability and health impacts of the devastating flood in Hanoi by identifying the differences in mortality, injuries, and morbidity patterns (dengue, pink eye, dermatitis, psychological problems, and hypertension between flood affected and non-affected households. A cross-sectional study was carried out involving 871 households in four selected communes (two heavily flood affected and two comparatively less affected from two severely flooded districts of Hanoi. Participants were interviewed and information collected on the social, economic, and health impacts of the devastation within 1 month after the flood. The self-reported number of deaths and injuries reported in this study within 1 month after the heavy rainfall were a bit higher in severely affected communes as compared to that of the less affected communes of our study. The findings showed higher incidences of dengue fever, pink eye, dermatitis, and psychological problems in communes severely affected by flood as compared to that of the controlled communes. For people in flood prone areas (at risk for flooding, flood prevention and mitigation strategies need to be seriously thought through and acted upon, as these people are exposed to greater health problems such as psychological issues and communicable diseases such as pink eye or dermatitis.

  12. ASSESSMENT OF FLOODED AREAS PROJECTIONS AND FLOODS POTENTIAL IMPACTS APPLYING REMOTE SENSING IMAGERY AND DEMOGRAPHIC DATA

    Directory of Open Access Journals (Sweden)

    D. A. Rodriguez

    2016-06-01

    Full Text Available Assessing vulnerability and potential impacts associated with extreme discharges requires an accurate topographic description in order to estimate the extension of flooded areas. However, in most populated regions, topographic data obtained by in-situ measurements is not available. In this case, digital elevation models derived from remote sensing date are usually applied. Moreover, this digital elevation models have intrinsic errors that introduce bigger uncertainty in results than the associated to hydrological projections. On the other hand, estimations of flooded areas through remote sensing images provide accurate information, which could be used for the construction of river level-flooded area relationships regarding vulnerability assessment. In this work, this approach is applied for the city of Porto Velho in the Brazilian Amazonia to assess potential vulnerability to floods associated with climate change projections. The approach is validated using census data, provided by the Brazilian Institute of Geography and Statistics, and information about socio-economical injuries associated to historical floods, provided by the Brazilian Civil Defence. Hydrological projections under climate change are carried out using several downscaling of climate projections as inputs in a hydrological model. Results show more accurate estimation of flood impacts than the obtained using digital elevation models derivate from remote sensing data. This reduces uncertainties in the assessment of vulnerability to floods associated with climate change in the region.

  13. Regional flood impact assessment for Kiel and Eckernförde, Germany

    Science.gov (United States)

    Shustikova, Iuliia; Viavattene, Christophe; Seiß, Guntram

    2017-04-01

    It is well-observed that extreme flood events bring considerable destruction to coastal communities. The estimates of damage increases when direct and indirect losses are both considered in the assessment. This study applied the INtegrated DisRuption Assessment (INDRA) model which is designed to estimate and compare not only tangible but also intangible losses such as risk to life, recovery mechanisms and household displacement. Multi-criteria analysis (MCA) was performed in order to compare hotspots of high flood risk on the regional scale and detect which impact indicators influence results the most. INDRA allowed assessing the following impact indicators: direct damages to buildings and roads, transport disruption, risk to life and financial recovery mechanisms of private households and businesses. The focus was on two hotspots of flood risk, where direct and indirect impacts from 200 years flood were assessed and analyzed in terms of relative importance to the region. The region here was defined as municipalities located on the Baltic Sea coast within the Schleswig-Holstein state, Germany. The hotspots are the towns of Kiel and Eckernförde. They are urban areas with a high concentration of people and assets, which previously experienced extreme flood events. From the performed investigation it was found out that modeled flood differently impacts Kiel and Eckernförde. The results produced by MCA show that the scores of direct and indirect damage are slightly higher in Eckernförde than in Kiel. Transport disruption is a compelling element in the performed regional impact assessment and demonstrated immense weight. Extreme events may pose significant direct and indirect impacts on the coastal roads, obstructing not only the access to important landmarks such as hospitals, train stations, harbors, etc. but also to contiguous municipalities. Yet, the analysis showed that other impact indicators are rather of local importance and would not cause vast damage on a

  14. Urban Land Pattern Impacts on Floods in a New District of China

    Directory of Open Access Journals (Sweden)

    Weizhong Su

    2014-09-01

    Full Text Available Urban floods are linked to patterns of land use, specifically urban sprawl. Since the 1980s, government-led new districts are sweeping across China, which account for many of the floods events. Focuses of urbanization impact on floods are extending gradually from hydraulic channels, to imperviousness ratio, to imperviousness pattern in urban areas or urbanized basins. Thus, the paper aims to explore how urban land pattern can affect floods in urban areas to provide decision makers with guidance on land use and stormwater management. Imperviousness was generally correlated with spatial variations in land use, with lower imperviousness in less dense, new districts, and higher imperviousness in more dense, uniform/clustered development in local areas adjacent to hot nodes. The way imperviousness and channel are organized, and the location of imperviousness within a catchment, can influence floods. Local government’s approach to new district planning, in terms of zoning provisions, has only considered some development aspects and has not adequately integrated flood management. A key issue for the planning should been done to adequately cater for flooding, particularly considering the benefits of keeping natural conveyance systems (rivers and their floodplains to manage flood waters.

  15. Utilizing NASA Earth Observations to Enhance Flood Impact Products and Mitigation in the Lower Mekong Water Basin

    Science.gov (United States)

    Doyle, C.; Gao, M.; Spruce, J.; Bolten, J. D.; Weber, S.

    2014-12-01

    This presentation discusses results of a project to develop a near real time flood monitoring capability for the Lower Mekong Water Basin (LMB), the largest river basin in Southeast Asia and home to more than sixty million people. The region has seen rapid population growth and socio-economic development, fueling unsustainable deforestation, agricultural expansion, and stream-flow regulation. The basin supports substantial rice farming and other agrarian activities, which heavily depend upon seasonal flooding. But, floods due to typhoons and other severe weather events can result in disasters that cost millions of dollars and cause hardships to millions of people. This study uses near real time and historical Aqua and Terra MODIS 250-m resolution Normalized Difference Vegetation Index (NDVI) products to map flood and drought impact within the LMB. In doing so, NDVI change products are derived by comparing from NDVI during the wet season to a baseline NDVI from the dry season. The method records flood events, which cause drastic decreases in NDVI compared to non-flooded conditions. NDVI change product computation was automated for updating a near real-time system, as part of the Committee on Earth Observing Satellites Disaster Risk Management Observation Strategy. The system is a web-based 'Flood Dashboard that will showcase MODIS flood monitoring products, along with other flood mapping and weather data products. This flood dashboard enables end-users to view and assess a variety of geospatial data to monitor floods and flood impacts in near real-time, as well provides a platform for further data aggregation for flood prediction modeling and post-event assessment.

  16. EPISODIC EVENTS: THE EFFECT OF FLOODS ON NUTRIENT TRANSPORT IN A NORTHWESTERN, USA ESTUARY

    Science.gov (United States)

    To estimate the effects of storms on nutrient transport, dissolved nutrients and suspended sediment loads were measured relative to stream discharge in the Yaquina River, OR for three storm events. Episodic events, particularly high rainfall or flood events may transport high di...

  17. Floods characterization: from impact data to quantitative assessment

    Science.gov (United States)

    Llasat, Maria-Carmen; Gilabert, Joan; Llasat-Botija, Montserrat; Marcos, Raül; Quintana-Seguí, Pere; Turco, Marco

    2015-04-01

    This study is based on the following flood databases from Catalonia: INUNGAMA (1900-2010) which considers 372 floods (Llasat et al, 2014), PRESSGAMA (1981-2010) and HISTOGAMA (from XIV Century on) - built as part of SPHERE project and recently updated. These databases store information about flood impacts (among others) and classify them by their severity (catastrophic, extraordinary and ordinary) by means of an indicators matrix based on other studies (i.e. Petrucci et al, 2013; Llasat et al, 2013). On this research we present a comparison between flood impacts, flow data and rainfall data on a Catalan scale and particularly for the basins of Segre, Muga, Ter and Llobregat (Western Mediterranean). From a bottom-up approach, a statistical methodology has been built (trend analysis, measures of position, cumulative distribution functions and geostatistics) in order to identify quantitative thresholds that will make possible to classify the floods. The purpose of this study is to establish generic thresholds for the whole Catalan region, for this we have selected rainfall maximums of flooding episodes stored at INUNGAMA and they have been related to flood categories by boxplot diagrams. Regarding the stream flow, we have established a relation between impacts and return periods at the day when the flow is maximum. The aim is to homogenize and compare the different drainage basins and to obtain general thresholds. It is also presented detailed analyses of relations between flooding episodes, flood classification and weather typing schemes - based in Jenkinson and Collison classification (applied to the Iberian Peninsula by Spellmann, 2000). In this way it could be analyzed whether patterns for the different types of floods exist or not. Finally, this work has pointed out the need of defining a new category for the most severe episodes.

  18. The record precipitation and flood event in Iberia in December 1876: description and synoptic analysis

    Directory of Open Access Journals (Sweden)

    Ricardo Machado Trigo

    2014-04-01

    Full Text Available The first week of December 1876 was marked by extreme weather conditions that affected the south-western sector of the Iberian Peninsula, leading to an all-time record flow in two large international rivers. 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. These unusual floods were amplified by the preceding particularly autumn wet months, with October 1876 presenting extremely high precipitation anomalies for all western Iberia stations. Two recently digitised stations in Portugal (Lisbon and Evora, present a peak value on 5 December 1876. Furthermore, the values of precipitation registered between 28 November and 7 December were so remarkable that, the episode of 1876 still corresponds to the maximum average daily precipitation values for temporal scales between 2 and 10 days. Using several different data sources, such as historical newspapers of that time, meteorological data recently digitised from several stations in Portugal and Spain and the recently available 20th Century Reanalysis, we provide a detailed analysis on the socio-economic impacts, precipitation values and the atmospheric circulation conditions associated with this event. The atmospheric circulation during these months was assessed at the monthly, daily and sub-daily scales. All months considered present an intense negative NAO index value, with November 1876 corresponding to the lowest NAO value on record since 1865. We have also computed a multivariable analysis of surface and upper air fields in order to provide some enlightening into the evolution of the synoptic conditions in the week prior to the floods. These events resulted from the continuous pouring of precipitation registered between 28 November and 7 December, due to the consecutive passage of Atlantic low-pressure systems fuelled by the presence of an atmospheric-river tropical moisture flow over

  19. Rising floodwaters: mapping impacts and perceptions of flooding in Indonesian Borneo

    Science.gov (United States)

    Wells, Jessie A.; Wilson, Kerrie A.; Abram, Nicola K.; Nunn, Malcolm; Gaveau, David L. A.; Runting, Rebecca K.; Tarniati, Nina; Mengersen, Kerrie L.; Meijaard, Erik

    2016-06-01

    The roles of forest and wetland ecosystems in regulating flooding have drawn increasing attention in the contexts of climate change adaptation and disaster risk reduction. However, data on floods are scarce in many of the countries where people are most exposed and vulnerable to their impacts. Here, our separate analyses of village interview surveys (364 villages) and news archives (16 sources) show that floods have major impacts on lives and livelihoods in Indonesian Borneo, and flooding risks are associated with features of the local climate and landscape, particularly land uses that have seen rapid expansions over the past 30 years. In contrast with government assessments, we find that flooding is far more widespread, and that frequent, local, events can have large cumulative impacts. Over three years, local news agencies reported floods that affected 868 settlements, 966 times (including 89 in urban areas), inundated at least 197 000 houses, and displaced more than 776 000 people, possibly as many as 1.5 million (i.e. 5%-10% of the total population). Spatial analyses based on surveys in 364 villages show that flood frequency is associated with land use in catchment areas, including forest cover and condition, and the area of wetlands, mines (open-cut coal or gold mines), and oil palm. The probability that floods have become more frequent over the past 30 years was higher for villages closer to mines, and in watersheds with more extensive oil palm, but lower in watersheds with greater cover of selectively-logged or intact forests. We demonstrate that in data-poor regions, multiple sources of information can be integrated to gain insights into the hydrological services provided by forest and wetland ecosystems, and motivate more comprehensive assessment of flooding risks and options for ecosystem-based adaptation.

  20. Near-Bed Monitoring of Suspended Sediment during a Major Flood Event Highlights Deficiencies in Existing Event-Loading Estimates

    Directory of Open Access Journals (Sweden)

    Alistair Grinham

    2018-01-01

    Full Text Available Rates of fluvial sediment discharge are notoriously difficult to quantify, particularly during major flood events. Measurements are typically undertaken using event stations requiring large capital investment, and the high cost tends to reduce the spatial coverage of monitoring sites. This study aimed to characterise the near-bed suspended sediment dynamics during a major flood event using a low-cost approach. Monitoring nodes consisted of a total suspended sediment (TSS logger, a single stage sampler, and a time-lapse camera for a total cost of less than US$420. Seven nodes were deployed across an elevation gradient on the stream bank of Laidley Creek, Queensland, Australia, and two of these nodes successfully characterised the near-bed suspended sediment dynamics across a major flood event. Near-bed TSS concentrations were closely related to stream flow, with the contribution of suspended bed material dominating the total suspended load during peak flows. Observed TSS concentrations were orders of magnitude higher than historical monitoring data for this site collected using the State government event station. This difference was attributed to the event station pump inlet screening the suspended bed material prior to sample collection. The ‘first flush’ phenomenon was detected and attributed to a local resuspension of muddy crusts immediately upstream of the study site. This low-cost approach will provide an important addition to the existing monitoring of fluvial sediment discharge during flood events.

  1. Impacts of Extreme Events on Human Health. Chapter 4

    Science.gov (United States)

    Bell, Jesse E.; Herring, Stephanie C.; Jantarasami, Lesley; Adrianopoli, Carl; Benedict, Kaitlin; Conlon, Kathryn; Escobar, Vanessa; Hess, Jeremy; Luvall, Jeffrey; Garcia-Pando, Carlos Perez; hide

    2016-01-01

    Increased Exposure to Extreme Events Key Finding 1: Health impacts associated with climate-related changes in exposure to extreme events include death, injury, or illness; exacerbation of underlying medical conditions; and adverse effects on mental health[High Confidence]. Climate change will increase exposure risk in some regions of the United States due to projected increases in the frequency and/or intensity of drought, wildfires, and flooding related to extreme precipitation and hurricanes [Medium Confidence].Disruption of Essential Infrastructure Key Finding 2: Many types of extreme events related to climate change cause disruption of infrastructure, including power, water, transportation, and communication systems, that are essential to maintaining access to health care and emergency response services and safeguarding human health [High Confidence].Vulnerability to Coastal Flooding Key Finding 3: Coastal populations with greater vulnerability to health impacts from coastal flooding include persons with disabilities or other access and functional needs, certain populations of color, older adults, pregnant women and children, low-income populations, and some occupational groups [High Confidence].Climate change will increase exposure risk to coastal flooding due to increases in extreme precipitation and in hurricane intensity and rainfall rates, as well as sea level rise and the resulting increases in storm surge.

  2. Impact of social preparedness on flood early warning systems

    Science.gov (United States)

    Girons Lopez, M.; Di Baldassarre, G.; Seibert, J.

    2017-01-01

    Flood early warning systems play a major role in the disaster risk reduction paradigm as cost-effective methods to mitigate flood disaster damage. The connections and feedbacks between the hydrological and social spheres of early warning systems are increasingly being considered as key aspects for successful flood mitigation. The behavior of the public and first responders during flood situations, determined by their preparedness, is heavily influenced by many behavioral traits such as perceived benefits, risk awareness, or even denial. In this study, we use the recency of flood experiences as a proxy for social preparedness to assess its impact on the efficiency of flood early warning systems through a simple stylized model and implemented this model using a simple mathematical description. The main findings, which are based on synthetic data, point to the importance of social preparedness for flood loss mitigation, especially in circumstances where the technical forecasting and warning capabilities are limited. Furthermore, we found that efforts to promote and preserve social preparedness may help to reduce disaster-induced losses by almost one half. The findings provide important insights into the role of social preparedness that may help guide decision-making in the field of flood early warning systems.

  3. FLCNDEMF: An Event Metamodel for Flood Process Information Management under the Sensor Web Environment

    Directory of Open Access Journals (Sweden)

    Nengcheng Chen

    2015-06-01

    Full Text Available Significant economic losses, large affected populations, and serious environmental damage caused by recurrent natural disaster events (NDE worldwide indicate insufficiency in emergency preparedness and response. The barrier of full life cycle data preparation and information support is one of the main reasons. This paper adopts the method of integrated environmental modeling, incorporates information from existing event protocols, languages, and models, analyzes observation demands from different event stages, and forms the abstract full life cycle natural disaster event metamodel (FLCNDEM based on meta-object facility. Then task library and knowledge base for floods are built to instantiate FLCNDEM, forming the FLCNDEM for floods (FLCNDEMF. FLCNDEMF is formalized according to Event Pattern Markup Language, and a prototype system, Natural Disaster Event Manager, is developed to assist in the template-based modeling and management. The flood in Liangzi (LZ Lake of Hubei, China on 16 July 2010 is adopted to illustrate how to apply FLCNDEM in real scenarios. FLCNDEM-based modeling is realized, and the candidate remote sensing (RS dataset for different observing missions are provided for LZ Lake flood. Taking the mission of flood area extraction as an example, the appropriate RS data are selected via the model of simplified general perturbation version 4, and the flood area in different phases are calculated and displayed on the map. The phase-based modeling and visualization intuitively display the spatial-temporal distribution and the evolution process of the LZ Lake flood, and it is of great significance for flood responding. In addition, through the extension mechanism, FLCNDEM can also be applied in other environmental applications, providing important support for full life cycle information sharing and rapid responding.

  4. Water-Borne Diseases and Extreme Weather Events in Cambodia: Review of Impacts and Implications of Climate Change

    OpenAIRE

    Davies, Grace I.; McIver, Lachlan; Kim, Yoonhee; Hashizume, Masahiro; Iddings, Steven; Chan, Vibol

    2014-01-01

    Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extre...

  5. Climate change impacts on flood risk and asset damages within mapped 100-year floodplains of the contiguous United States

    Science.gov (United States)

    Wobus, Cameron; Gutmann, Ethan; Jones, Russell; Rissing, Matthew; Mizukami, Naoki; Lorie, Mark; Mahoney, Hardee; Wood, Andrew W.; Mills, David; Martinich, Jeremy

    2017-12-01

    A growing body of work suggests that the extreme weather events that drive inland flooding are likely to increase in frequency and magnitude in a warming climate, thus potentially increasing flood damages in the future. We use hydrologic projections based on the Coupled Model Intercomparison Project Phase 5 (CMIP5) to estimate changes in the frequency of modeled 1 % annual exceedance probability (1 % AEP, or 100-year) flood events at 57 116 stream reaches across the contiguous United States (CONUS). We link these flood projections to a database of assets within mapped flood hazard zones to model changes in inland flooding damages throughout the CONUS over the remainder of the 21st century. Our model generates early 21st century flood damages that reasonably approximate the range of historical observations and trajectories of future damages that vary substantially depending on the greenhouse gas (GHG) emissions pathway. The difference in modeled flood damages between higher and lower emissions pathways approaches USD 4 billion per year by 2100 (in undiscounted 2014 dollars), suggesting that aggressive GHG emissions reductions could generate significant monetary benefits over the long term in terms of reduced flood damages. Although the downscaled hydrologic data we used have been applied to flood impacts studies elsewhere, this research expands on earlier work to quantify changes in flood risk by linking future flood exposure to assets and damages on a national scale. Our approach relies on a series of simplifications that could ultimately affect damage estimates (e.g., use of statistical downscaling, reliance on a nationwide hydrologic model, and linking damage estimates only to 1 % AEP floods). Although future work is needed to test the sensitivity of our results to these methodological choices, our results indicate that monetary damages from inland flooding could be significantly reduced through substantial GHG mitigation.

  6. Impacts of flood on children and adults’ health and ways to sustainable development

    Science.gov (United States)

    Mohamed, S.; Ebenehi, I. Y.; Adaji, A.; Seow, T. W.; Chan, N. W.; Goh, K. C.; Rahim, M. H. I. Abd

    2017-11-01

    One of the events that will remain fresh in the minds of Kelantanese is the 2014 massive flood that occurred at the end of that year. Heavy rains fell initiating vast flooding in most areas of Kelantan leading to great destruction of livelihood of local communities. Natural hazard such as floods are not only caused by natural processes but also by human activities. The flood recorded severe fatalities, injuries and exposed many vulnerable to diseases. This paper through critical review of literature considered the long-term impact of floods on human’s health as the effects could meaningfully contribute to the worldwide burden of disease. Also, its outcomes are relentless hence need to be adequately comprehended and addressed through sustainability. This study revealed vulnerability to flood inclined ailments as psychological distress in the survivors is liable for a quota of all physical ailments. Hence, sustainable approach to flood preparedness and prevention is instantly needed. Accolades should be given to the Malaysian government for taken bold steps in that direction in recent time but success will be achieved if implementation is in compliance with sustainability agenda spelt in the New Sendai Framework for Disaster Risk Reduction 2015-2030.

  7. From flood-event to climate in an alpine context (Arve valley, France): methodological issues toward the confrontation of historical documentation and geological records

    Science.gov (United States)

    Mélo, Alain; Ployon, Estelle; Wilhelm, Bruno; Arnaud, Fabien

    2014-05-01

    Floods are complex multifactor events. As it can occur randomly on a given region, a given singular event does not clearly inform about climate variations. On the contrary, long-time series of well documented events, each one being replaced in its historical and geographical context, should bring valuable information. Such successions can be built-up using heterogeneous historical documentation taken from various social contexts. This is the case of small drainage basin of river Arve and its tributaries (Northern French Alps), on which this paper will focus. We used a plentiful and rich documentation which was elaborated quite exclusively to report damages in the aim of claiming tax abatement. As a consequence each text requires a hard critic to reach the necessary objectivity. The analysis of 18th century treasury archives led first to a geographical reconstruction of floods impacts and second to an unambiguous chronology of events. The contrasted morphology of river Arve drainage basin generates various types of floods, depending on geographical situations: summer flash-floods in the higher parts of valleys (Chamonix, Sixt) or torrential tributaries (Borne); autumn large floods in lower parts (Bonneville); some unusual events concern the whole basin (1733, 1778...). The constitution of long continuous series was thus possible. However, this does not allow evidencing any trend because most of the events are randomly-distributed flash-floods. In return, meteorological contextualization of each event replaces it in a larger climatic perception. Using this way (meteorological archives, comparisons with recently well-documented event) led us to corroborate connections between flood events and changing patterns. In order to go a step further, we led a pilot-study aiming at representing our data in space-time information system using concepts and tools of time geography. This study was limited to year 1930 AD which was rich in various meteorological events leading to

  8. ENSO impacts on flood risk at the global scale

    Science.gov (United States)

    Ward, Philip; Dettinger, Michael; Jongman, Brenden; Kummu, Matti; Winsemius, Hessel

    2014-05-01

    We present the impacts of El Niño Southern Oscillation (ENSO) on society and the economy, via relationships between ENSO and the hydrological cycle. We also discuss ways in which this knowledge can be used in disaster risk management and risk reduction. This contribution provides the most recent results of an ongoing 4-year collaborative research initiative to assess and map the impacts of large scale interannual climate variability on flood hazard and risk at the global scale. We have examined anomalies in flood risk between ENSO phases, whereby flood risk is expressed in terms of indicators such as: annual expected damage; annual expected affected population; annual expected affected Gross Domestic Product (GDP). We show that large anomalies in flood risk occur during El Niño or La Niña years in basins covering large parts of the Earth's surface. These anomalies reach statistical significance river basins covering almost two-thirds of the Earth's surface. Particularly strong anomalies exist in southern Africa, parts of western Africa, Australia, parts of Central Eurasia (especially for El Niño), the western USA (especially La Niña anomalies), and parts of South America. We relate these anomalies to possible causal relationships between ENSO and flood hazard, using both modelled and observed data on flood occurrence and extremity. The implications for flood risk management are many-fold. In those regions where disaster risk is strongly influenced by ENSO, the potential predictably of ENSO could be used to develop probabilistic flood risk projections with lead times up to several seasons. Such data could be used by the insurance industry in managing risk portfolios and by multinational companies for assessing the robustness of their supply chains to potential flood-related interruptions. Seasonal forecasts of ENSO influence of peak flows could also allow for improved flood early warning and regulation by dam operators, which could also reduce overall risks

  9. The effects of low impact development on urban flooding under different rainfall characteristics.

    Science.gov (United States)

    Qin, Hua-peng; Li, Zhuo-xi; Fu, Guangtao

    2013-11-15

    Low impact development (LID) is generally regarded as a more sustainable solution for urban stormwater management than conventional urban drainage systems. However, its effects on urban flooding at a scale of urban drainage systems have not been fully understood particularly when different rainfall characteristics are considered. In this paper, using an urbanizing catchment in China as a case study, the effects of three LID techniques (swale, permeable pavement and green roof) on urban flooding are analyzed and compared with the conventional drainage system design. A range of storm events with different rainfall amounts, durations and locations of peak intensity are considered for holistic assessment of the LID techniques. The effects are measured by the total flood volume reduction during a storm event compared to the conventional drainage system design. The results obtained indicate that all three LID scenarios are more effective in flood reduction during heavier and shorter storm events. Their performance, however, varies significantly according to the location of peak intensity. That is, swales perform best during a storm event with an early peak, permeable pavements perform best with a middle peak, and green roofs perform best with a late peak, respectively. The trends of flood reduction can be explained using a newly proposed water balance method, i.e., by comparing the effective storage depth of the LID designs with the accumulative rainfall amounts at the beginning and end of flooding in the conventional drainage system. This paper provides an insight into the performance of LID designs under different rainfall characteristics, which is essential for effective urban flood management. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Analysis of storm tracks associated with flood events across the Paraguay River Basin

    Science.gov (United States)

    Santos, Marcus; Moura, Leonardo; Lima, Carlos; Mediero, Luis

    2017-04-01

    The hydrological time series of the Paraguay River Basin located in the Pantanal region of Brazil exhibits a complex and interesting behavior. Previous studies identified monotonic trends, multiple step changes and strong seasonality in flows and rainfall data, imposing therefore major challenges in the water resources and flood risk management in the region. The attribution of such changes is thus of particular interest, and in this work we analyze storm tracks across the Paraguay River Basin in order to better understand moisture sources and identify large scale climate patterns associated with the largest flood events in the basin. The storm path traced by virtual particles and the moisture gains and losses along such paths are obtained using the HYSPLIT Lagrangian model and the NCEP/NCAR reanalysis data for the period 1970-2016. A K-means clustering algorithm is employed to find patterns in the storm track data and for each cluster we obtain the distribution and statistics of the associated flood events. Preliminary results show that the source regions of moisture, namely tropical North Atlantic, South Atlantic and Amazon, play a significant role on the features of flood events, particularly in the magnitude of these events. Major floods seem to be related to a large influx of moisture coming from the Amazon region. We also observe that base flow and internal dynamics of the catchment play a minor role on the streamflow variability. These findings are a new step towards a better understanding and improvement of the flood risk management in the region.

  11. Coping with floods after the severe event in 2002: Recent changes in preparedness, response and recovery of flood-affected residents in Germany

    Science.gov (United States)

    Kienzler, Sarah; Pech, Ina; Kreibich, Heidi; Müller, Meike; Thieken, Annegret

    2014-05-01

    In the aftermath of the severe flood in August 2002, a number of political changes on flood policies in Germany and Europe were launched aiming at an improved risk communication and management. The question arises, whether flood-affected private households are now better prepared than in 2002. Therefore, computer-aided telephone interviews with private households that suffered property damage due to flooding in 2005, 2006, 2010 or 2011 were performed. The obtained data were also compared to results from a similar investigation carried out by Thieken et al. (2007 - Hydrol. Sci. J. 52(5): 1016-1037) after the flood in 2002. After 2002, a larger part of people knew that they are at risk of flooding and the level of private precaution increased considerably. Yet this knowledge did not necessarily result in actual building retrofitting or flood proofing measures. Accordingly, the benefits and cost savings of these actions still have to be communicated in a better way. Best precaution before the flood event in 2011 and 2006 might be explained by more flood experience and overall greater awareness of the residents. Early warning and emergency response were substantially influenced by the floods' characteristics. In contrast to flood-affected people in 2006 or 2011, people affected by floods in 2005 or 2010 had to deal with shorter lead times, less time to take emergency measures and consequently suffered higher losses. Therefore, it is important to further improve early warning systems and communication channels, particularly in hilly areas with fast onset flooding.

  12. 3D Simulation of External Flooding Events for the RISMC Pathway

    International Nuclear Information System (INIS)

    Prescott, Steven; Mandelli, Diego; Sampath, Ramprasad; Smith, Curtis; Lin, Linyu

    2015-01-01

    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 the design, improves the realism of results, and can prove visual understanding to validate the analysis of flooding.

  13. Flood Impacts on People: from Hazard to Risk Maps

    Science.gov (United States)

    Arrighi, C.; Castelli, F.

    2017-12-01

    The mitigation of adverse consequences of floods on people is crucial for civil protection and public authorities. According to several studies, in the developed countries the majority of flood-related fatalities occurs due to inappropriate high risk behaviours such as driving and walking in floodwaters. In this work both the loss of stability of vehicles and pedestrians in floodwaters are analysed. Flood hazard is evaluated, based on (i) a 2D inundation model of an urban area, (ii) 3D hydrodynamic simulations of water flows around vehicles and human body and (iii) a dimensional analysis of experimental activity. Exposure and vulnerability of vehicles and population are assessed exploiting several sources of open GIS data in order to produce risk maps for a testing case study. The results show that a significant hazard to vehicles and pedestrians exists in the study area. Particularly high is the hazard to vehicles, which are likely to be swept away by flood flow, possibly aggravate damages to structures and infrastructures and locally alter the flood propagation. Exposure and vulnerability analysis identifies some structures such as schools and public facilities, which may attract several people. Moreover, some shopping facilities in the area, which attract both vehicular and pedestrians' circulation are located in the highest flood hazard zone.The application of the method demonstrates that, at municipal level, such risk maps can support civil defence strategies and education to active citizenship, thus contributing to flood impact reduction to population.

  14. An uncertainty-based framework to quantifying climate change impacts on coastal flood vulnerability: case study of New York City.

    Science.gov (United States)

    Zahmatkesh, Zahra; Karamouz, Mohammad

    2017-10-17

    The continued development efforts around the world, growing population, and the increased probability of occurrence of extreme hydrologic events have adversely affected natural and built environments. Flood damages and loss of lives from the devastating storms, such as Irene and Sandy on the East Coast of the USA, are examples of the vulnerability to flooding that even developed countries have to face. The odds of coastal flooding disasters have been increased due to accelerated sea level rise, climate change impacts, and communities' interest to live near the coastlines. Climate change, for instance, is becoming a major threat to sustainable development because of its adverse impacts on the hydrologic cycle. Effective management strategies are thus required for flood vulnerability reduction and disaster preparedness. This paper is an extension to the flood resilience studies in the New York City coastal watershed. Here, a framework is proposed to quantify coastal flood vulnerability while accounting for climate change impacts. To do so, a multi-criteria decision making (MCDM) approach that combines watershed characteristics (factors) and their weights is proposed to quantify flood vulnerability. Among the watershed characteristics, potential variation in the hydrologic factors under climate change impacts is modeled utilizing the general circulation models' (GCMs) outputs. The considered factors include rainfall, extreme water level, and sea level rise that exacerbate flood vulnerability through increasing exposure and susceptibility to flooding. Uncertainty in the weights as well as values of factors is incorporated in the analysis using the Monte Carlo (MC) sampling method by selecting the best-fitted distributions to the parameters with random nature. A number of low impact development (LID) measures are then proposed to improve watershed adaptive capacity to deal with coastal flooding. Potential range of current and future vulnerability to flooding is

  15. Societal impacts and vulnerability to floods in Bangladesh and Nepal

    Directory of Open Access Journals (Sweden)

    Tanvir H. Dewan

    2015-03-01

    Full Text Available Bangladesh and Nepal lie between the Himalayas and low-lying coasts of the Bay of Bengal and are traversed by hundreds of rivers and tributaries. Historical data shows that, since 1970, the scale, intensity and duration of floods have increased in Bangladesh and Nepal, causing grave human suffering; disruptions in normal life and activity, damages of infrastructure, crops and agricultural land with severe impacts on the economy. Bangladesh is affected by torrential rain, glacier melt, upstream water flow and tidal surges. In 1988, Bangladesh experienced one of the most severe floods of the twentieth century which aroused significant concern internationally and triggered the Bangladesh Action Plan for Flood Control. The Government of Bangladesh (GOB has so far constructed a number of flood shelters and carried out 482 water and flood control projects involving flood protection embankments, drainage channels, sluice gates and regulators on different rivers and canals. These also provided safety measures against inundation by tidal waves, storm-surges and flooding. The Terai region of Nepal is highly prone to hydrological risks including torrential rain, floods, glaciers resulting in erosion and landslides. The Government of Nepal (GON has implemented different mitigation measures mainly early warning awareness, rescue measure, relief, and post-flood rehabilitation programs etc. Disaster Management Bureaus of both the countries have already conducted many trainings, workshops and seminars to disseminate scientific knowledge and coping up practices to disaster managers and to create public awareness. Besides the contemporary approaches to mitigating flood effects, people of these countries have coped with floods through generations relying on traditional/indigenous knowledge and other local adaptation practices. It is crucial that along with scientific process, indigenous, traditional and conventional practices are to be integrated for a national

  16. Flood-risk mapping: contributions towards an enhanced assessment of extreme events and associated risks

    Directory of Open Access Journals (Sweden)

    B. Büchele

    2006-01-01

    Full Text Available Currently, a shift from classical flood protection as engineering task towards integrated flood risk management concepts can be observed. In this context, a more consequent consideration of extreme events which exceed the design event of flood protection structures and failure scenarios such as dike breaches have to be investigated. Therefore, this study aims to enhance existing methods for hazard and risk assessment for extreme events and is divided into three parts. In the first part, a regionalization approach for flood peak discharges was further developed and substantiated, especially regarding recurrence intervals of 200 to 10 000 years and a large number of small ungauged catchments. Model comparisons show that more confidence in such flood estimates for ungauged areas and very long recurrence intervals may be given as implied by statistical analysis alone. The hydraulic simulation in the second part is oriented towards hazard mapping and risk analyses covering the whole spectrum of relevant flood events. As the hydrodynamic simulation is directly coupled with a GIS, the results can be easily processed as local inundation depths for spatial risk analyses. For this, a new GIS-based software tool was developed, being presented in the third part, which enables estimations of the direct flood damage to single buildings or areas based on different established stage-damage functions. Furthermore, a new multifactorial approach for damage estimation is presented, aiming at the improvement of damage estimation on local scale by considering factors like building quality, contamination and precautionary measures. The methods and results from this study form the base for comprehensive risk analyses and flood management strategies.

  17. Impact of intense rains and flooding on mercury riverine input to the coastal zone.

    Science.gov (United States)

    Dominika, Saniewska; Magdalena, Bełdowska; Jacek, Bełdowski; Michał, Saniewski; Karolina, Gębka; Marta, Szubska; Agnieszka, Wochna

    2018-02-01

    The aim of the present research was to determine the impact of intense rains and flooding on mercury riverine input to the coastal zone. This study focused on four small rivers (Reda, Zagórska Struga, Płutnica, Gizdepka), typical of the Southern Baltic region, with no significant mercury sources. Samples were collected for 16months during average flow conditions and during selected meteorological events: floods, downpours, thaws and droughts. Results showed decreased retention of mercury during intense rainfalls, thus demonstrating mercury elution from the catchment. Floods and melting snow also have a tremendous impact on the outflow of mercury from the catchment. Development of urban infrastructure and farmlands increases the outflow of mercury from the catchment too, making such areas a significant source of mercury in the river. On the other hand, areas with natural character, predominated by forests, stimulate retention of mercury that reaches them through dry and wet atmospheric deposition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Urban and peri-urban flood impact change: the case of the Metropolitan Area of Barcelona

    Science.gov (United States)

    Cortès, Maria; Gilabert, Joan; Llasat-Botija, Montserrat; Marcos, Raül; Llasat, Maria del Carmen

    2017-04-01

    Floods are the most important natural hazard in the world. Nowadays, mitigation and adaptation strategies to reduce the impact that climate change will have on them, are a priority in most government agendas. Recent reports from the IPCC (2012, 2014) still show significant uncertainty associated with future projections of precipitation extremes. This uncertainty is higher when referred to floods and even larger when interactions with society and the changes in vulnerability are considered. Consequently, there is now a call to treat floods from a holistic perspective that integrates bottom-up (from impact and vulnerability) and top-down (from hazard) approaches (Hall et al., 2014). The study of flood risk in urban and peri-urban areas is complex and involves multiple factors. This is the case of the Metropolitan Area of Barcelona (AMB), which concentrates 43% of total population of Catalonia in less than 2% of the whole territory. The impervious soil has grown more than 200% from 1956 to 2009 (resulting in higher values of runoff), the population has increased more than 80% in the same period and, simultaneously, an improvement of the drainage system and flood prevention has been developed. As a result, we have seen that the flood risk evolution in the area holds a strong link to these human changes. Actually, floods in this region are usually due to drainage problems, flash floods in ungauged torrential catchments and, only in some occasions, river floods are produced (i.e. the Llobregat River on September 1971). But, in all the cases they are due to heavy precipitations. The main objective of the contribution is assessing the relationship between precipitation in the AMB and the social impacts produced. In order to do it, different impact indicators have been proposed, such as the population affected or the duration of the flood event (Merz et al., 2010). These indicators have been implemented for the different cases analyzed, which affected AMB for the period

  19. A Review on Flood Events for Kelantan River Watershed in Malaysia for Last Decade (2001-2010)

    Science.gov (United States)

    Aminah Shakirah, J.; Sidek, L. M.; Hidayah, B.; Nazirul, M. Z.; Jajarmizadeh, M.; Ros, F. C.; Roseli, ZA

    2016-03-01

    Malaysia is located at tropical zone and high precipitation area that frequently hit by flood events when it is near monsoon season. This hydro hazard has been one of the main concerns for governmental and non-governmental sectors. High floods lead in financial damages and they are related with human’s life. Kelantan watershed is one of the challenging watersheds which mostly suffer from flood events and heavy rainfall events. Flood in Kelantan watershed is related with monetary misfortunes and lives. Clearly, flood have significant influence on various water sectors such water supply, agriculture, human health and ecosystems therefore study of this topic and presentation of available of any data and information can be a valuable baseline for upcoming research in vulnerable case studies. In this study, Kelantan watershed is selected because it is prone to flooding and urban areas classified as vulnerable districts. This overview is discussed on the last decade (2001-2010) floods events in Kelantan.

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

    Science.gov (United States)

    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

  1. A Framework for Evaluating the Impact of Uncertainty in Flood Damage Assessment

    Science.gov (United States)

    Abu Shoaib, S.; Marshall, L. A.; Sharma, A.

    2016-12-01

    Design flood estimation is a necessary step in evaluating the risk associated with socioeconomic impacts of flood events in any location. However prediction or modelling of peak flows is subject to uncertainty associated with the selection of a hydrologic model structure and related model parameters. In this study, we introduce a new uncertainty metric, the Quantile Flow Deviation or QFD, to evaluate the relative uncertainty in flood simulations due to different model attributes (such as the model structure, parameter sets, likelihoods or driving data). Through the metric, we identify the potential spectrum of uncertainty in peak flow and variability in our model simulations. By using a quantile based metric, the change in uncertainty across individual percentiles can be assessed, thereby allowing uncertainty to be expressed as a function of magnitude and time. Via the QFD and a catchment damage function, we can then extrapolate the estimation of flood uncertainty to evaluate the potential extent of flood damages. We demonstrate the methodology for a given catchment and evaluate the impact of uncertainty on both peak flow and damage estimates. Overall, we demonstrate that an appropriate framework for estimating damage uncertainty is vital in water resources planning and design with potential long term socio-economic impacts.

  2. State-of-the-art for evaluating the potential impact of flooding on a radioactive waste repository

    International Nuclear Information System (INIS)

    1980-01-01

    This report is a review of the state-of-the-art for evaluating the potential impact of flooding on a deep radioactive-waste repository, namely, for predicting the future occurrence of catastrophic flooding and for estimating the effect of such flooding on waste containment characteristics. Several detrimental effects are identified: flooding can increase groundwater seepage velocities through a repository within the framework of the existing hydrologic system and thus increase the rate of radioactive-waste leakage to the biosphere; flooding may alter repository hydrology by reversing flow gradients, relocating sources of groundwater recharge and discharge, or shortening seepage paths, thereby producing unpredictable leakage; saturation of a vadose-zone repository during flooding can increase groundwater seepage velocities by several orders of magnitude; and flooding can damage repository-media containment properties by inducing seismic or chemical instability or increasing fracture permeability in relatively shallow repository rock as a result of redistributing in-situ stresses. Short-term flooding frequency and magnitude can be predicted statistically by analyzing historical records of flooding. However, long-term flooding events that could damage a permanent repository cannot be predicted with confidence because the geologic record is neither unique nor sufficienly complete for statistical analysis. It is more important to identify parameters characterizing containment properties (such as permeability, groundwater gradient, and shortest seepage path length to the biosphere) that could be affected by future flooding, estimate the maximum magnitude of flooding that could occur within the life of the repository by examining the geologic record, and determine the impact such flooding could have on the parameter values

  3. Projected burden of disease for bacillary dysentery due to flood events in Guangxi, China.

    Science.gov (United States)

    Liu, Xuena; Liu, Zhidong; Ding, Guoyong; Jiang, Baofa

    2017-12-01

    Many researchers have been studying the influence of floods on intestinal infection in recent years. This study aimed to project the future disease burden of bacillary dysentery associated with floods in Guangxi, China. Relying on the longitudinal data, a generalized additive mixed model was applied to quantify the relationship between the monthly morbidity of bacillary dysentery and floods with two severity levels from 2004 to 2010, controlling for other meteorological variables. Years Lived with Disability (YLDs) was used as the measure of the burden of bacillary dysentery in the future of Guangxi, China. According to the generalized additive mixed model, the relative risks (RR) of moderate and severe floods on the morbidity of bacillary dysentery were 1.17 (95% CI: 1.03-1.33) and 1.39 (95% CI: 1.14-1.70), respectively. The regression analysis also indicated that the flood duration was negatively associated with the morbidity of bacillary dysentery (with RR: 0.63, 95% CI: 0.44-0.90). Considering the effects of floods only, compared with the YLDs in 2010, increasing flood events may lead to a 4.0% increase in the YLDs for bacillary dysentery by 2020, 2100, 0.0% by 2050, and an 8.0% increase by 2030 in Guangxi, if other factors remain constant. Considering all potential changes include floods, temperature and population size, the YLDs for bacillary dysentery may increase by up to 16.0% by 2020, 20.0% by 2030, 2050, and 0.0% by 2100, compared to that in 2010 under the moderate flood scenario; Under the severe flood scenario, the YLDs for bacillary dysentery may increase by up to 16.0% by 2020, 20.0% by 2030, 2050, and 4.0% by 2100. Copyright © 2017. Published by Elsevier B.V.

  4. Reconstructing the 2015 Flash Flood event of Salgar Colombia, The Case of a Poor Gauged Basin

    Science.gov (United States)

    Velasquez, N.; Zapata, E.; Hoyos Ortiz, C. D.; Velez, J. I.

    2017-12-01

    Flash floods events associated with severe precipitation events are highly destructive, often resulting in significant human and economic losses. Due to their nature, flash floods trend to occur in medium to small basins located within complex high mountainous regions. In the Colombian Andean region these basins are very common, with the aggravating factor that the vulnerability is considerably high as some important human settlements are located within these basins, frequently occupating flood plains and other flash-flood prone areas. During the dawn of May 18 of 2015 two severe rainfall events generated a flash flood event in the municipality ofSalgar, La Liboriana basin, locatedin the northwestern Colombian Andes, resulting in more than 100 human casualties and significant economic losses. The present work is a reconstruction of the hydrological processes that took place before and during the Liboriana flash flood event, analyzed as a case of poorly gauged basin.The event conditions where recreated based on radar retrievals and a hydrological distributed model, linked with a proposed 1D hydraulic model and simple shallow landslide model. Results suggest that the flash flood event was caused by the occurrence of two successive severe convective events over the same basin, with an important modulation associated with soil characteristics and water storage.Despite of its simplicity, the proposed hydraulic model achieves a good representation of the flooded area during the event, with limitations due to the adopted spatial scale (12.7 meters, from ALOS PALSAR images). Observed landslides were obtained from satellite images; for this case the model simulates skillfully the landslide occurrence regions with small differences in the exact locations.To understand this case, radar data shows to be key due to specific convective cores location and rainfall intensity estimation.In mountainous regions, there exists a significant number of settlements with similar

  5. Sub-seasonal Predictability of Heavy Precipitation Events: Implication for Real-time Flood Management in Iran

    Science.gov (United States)

    Najafi, H.; Shahbazi, A.; Zohrabi, N.; Robertson, A. W.; Mofidi, A.; Massah Bavani, A. R.

    2016-12-01

    Each year, a number of high impact weather events occur worldwide. Since any level of predictability at sub-seasonal to seasonal timescale is highly beneficial to society, international efforts is now on progress to promote reliable Ensemble Prediction Systems for monthly forecasts within the WWRP/WCRP initiative (S2S) project and North American Multi Model Ensemble (NMME). For water resources managers in the face of extreme events, not only can reliable forecasts of high impact weather events prevent catastrophic losses caused by floods but also contribute to benefits gained from hydropower generation and water markets. The aim of this paper is to analyze the predictability of recent severe weather events over Iran. Two recent heavy precipitations are considered as an illustration to examine whether S2S forecasts can be used for developing flood alert systems especially where large cascade of dams are in operation. Both events have caused major damages to cities and infrastructures. The first severe precipitation was is in the early November 2015 when heavy precipitation (more than 50 mm) occurred in 2 days. More recently, up to 300 mm of precipitation is observed within less than a week in April 2016 causing a consequent flash flood. Over some stations, the observed precipitation was even more than the total annual mean precipitation. To analyze the predictive capability, ensemble forecasts from several operational centers including (European Centre for Medium-Range Weather Forecasts (ECMWF) system, Climate Forecast System Version 2 (CFSv2) and Chinese Meteorological Center (CMA) are evaluated. It has been observed that significant changes in precipitation anomalies were likely to be predicted days in advance. The next step will be to conduct thorough analysis based on comparing multi-model outputs over the full hindcast dataset developing real-time high impact weather prediction systems.

  6. Floods

    Science.gov (United States)

    Floods are common in the United States. Weather such as heavy rain, thunderstorms, hurricanes, or tsunamis can ... is breached, or when a dam breaks. Flash floods, which can develop quickly, often have a dangerous ...

  7. Assessing the Vulnerability of Structures and Residential Communities to Storm Surge: An Analysis of Flood Impact during Hurricane Sandy

    Directory of Open Access Journals (Sweden)

    Adam Hatzikyriakou

    2018-02-01

    Full Text Available With 6.5 million households in the United States located in areas prone to storm surge, assessing the vulnerability of structures and residential communities to coastal flooding is an important concern. Of particular interest is understanding how the performance of structures during surge events is influenced by flood conditions, coastal defenses, and building design at both the house and community level. This study presents such a vulnerability analysis by investigating the impact of coastal flooding from Hurricane Sandy (2012 on 95 km of developed coastline across New Jersey and New York. Exterior structural damage observed from a Federal Emergency Management Agency (FEMA aerial survey of the study area is related to (1 a hindcast simulation of flood inundation and wave action, (2 a classification of coastal defenses and storm-induced erosion, and (3 minimum building design elevations specified in FEMA’s flood hazard mapping. Findings indicate that the hardest hit communities experienced significant dune erosion, which coincided with severe flood and wave exposure. Furthermore, structures were considerably more susceptible to flood impact if Sandy’s flood level exceeded FEMA’s 100-year Base Flood Elevation dictating building design. These results are quantified by developing fragility curves relating both house and community-level performance to the considered vulnerability parameters. Findings from this study can be used to inform decision making for improving coastal resilience.

  8. A Real-Time Web Services Hub to Improve Situation Awareness during Flash Flood Events

    Science.gov (United States)

    Salas, F. R.; Liu, F.; Maidment, D. R.; Hodges, B. R.

    2011-12-01

    The central Texas corridor is one of the most flash flood-prone regions in the United States. Over the years, flash floods have resulted in hundreds of flood fatalities and billions of dollars in property damage. In order to mitigate risk to residents and infrastructure during flood events, both citizens and emergency responders need to exhibit proactive behavior instead of reactive. Real-time and forecasted flood information is fairly limited and hard to come by at varying spatial scales. The University of Texas at Austin has collaborated with IBM Research-Austin and ESRI to build a distributed real-time flood information system through a framework that leverages large scale data management and distribution, Open Geospatial Consortium standardized web services, and smart map applications. Within this paradigm, observed precipitation data encoded in WaterML is ingested into HEC-HMS and then delivered to a high performance hydraulic routing software package developed by IBM that utilizes the latest advancements in VLSI design, numerical linear algebra and numerical integration techniques on contemporary multicore architecture to solve fully dynamic Saint Venant equations at both small and large scales. In this paper we present a real-time flood inundation map application that in conjunction with a web services Hub, seamlessly integrates hydrologic information available through both public and private data services, model services and mapping services. As a case study for this project, we demonstrate how this system has been implemented in the City of Austin, Texas.

  9. Flood impacts in Keppel Bay, southern great barrier reef in the aftermath of cyclonic rainfall.

    Directory of Open Access Journals (Sweden)

    Alison M Jones

    Full Text Available In December 2010, the highest recorded Queensland rainfall associated with Tropical Cyclone 'Tasha' caused flooding of the Fitzroy River in Queensland, Australia. A massive flood plume inundated coral reefs lying 12 km offshore of the Central Queensland coast near Yeppoon and caused 40-100% mortality to coral fringing many of the islands of Keppel Bay down to a depth of ∼8 m. The severity of coral mortality was influenced by the level of exposure to low salinity seawater as a result of the reef's distance from the flood plume and to a lesser extent, water depth and whether or not the reef faced the plume source. There was no evidence in this study of mortality resulting from pollutants derived from the nearby Fitzroy Catchment, at least in the short term, suggesting that during a major flood, the impact of low salinity on corals outweighs that of pollutants. Recovery of the reefs in Keppel Bay from the 2010/2011 Fitzroy River flood is likely to take 10-15 years based on historical recovery periods from a similar event in 1991; potentially impacting visitor numbers for tourism and recreational usage. In the meantime, activities like snorkeling, diving and coral viewing will be focused on the few shallow reefs that survived the flood, placing even further pressure on their recovery. Reef regeneration, restoration and rehabilitation are measures that may be needed to support tourism in the short term. However, predictions of a warming climate, lower rainfall and higher intensity summer rain events in the Central and Coastal regions of Australia over the next decade, combined with the current anthropogenic influences on water quality, are likely to slow regeneration with consequent impact on long-term reef resilience.

  10. Flood impacts in Keppel Bay, southern great barrier reef in the aftermath of cyclonic rainfall.

    Science.gov (United States)

    Jones, Alison M; Berkelmans, Ray

    2014-01-01

    In December 2010, the highest recorded Queensland rainfall associated with Tropical Cyclone 'Tasha' caused flooding of the Fitzroy River in Queensland, Australia. A massive flood plume inundated coral reefs lying 12 km offshore of the Central Queensland coast near Yeppoon and caused 40-100% mortality to coral fringing many of the islands of Keppel Bay down to a depth of ∼8 m. The severity of coral mortality was influenced by the level of exposure to low salinity seawater as a result of the reef's distance from the flood plume and to a lesser extent, water depth and whether or not the reef faced the plume source. There was no evidence in this study of mortality resulting from pollutants derived from the nearby Fitzroy Catchment, at least in the short term, suggesting that during a major flood, the impact of low salinity on corals outweighs that of pollutants. Recovery of the reefs in Keppel Bay from the 2010/2011 Fitzroy River flood is likely to take 10-15 years based on historical recovery periods from a similar event in 1991; potentially impacting visitor numbers for tourism and recreational usage. In the meantime, activities like snorkeling, diving and coral viewing will be focused on the few shallow reefs that survived the flood, placing even further pressure on their recovery. Reef regeneration, restoration and rehabilitation are measures that may be needed to support tourism in the short term. However, predictions of a warming climate, lower rainfall and higher intensity summer rain events in the Central and Coastal regions of Australia over the next decade, combined with the current anthropogenic influences on water quality, are likely to slow regeneration with consequent impact on long-term reef resilience.

  11. Retrospective Analysis of Recent Flood Events With Persistent High Surface Runoff From Hydrological Modelling

    Science.gov (United States)

    Joshi, S.; Hakeem, K. Abdul; Raju, P. V.; Rao, V. V.; Yadav, A.; Diwakar, P. G.; Dadhwal, V. K.

    2014-11-01

    Floods are one of the most common and widespread disasters in India, with an estimated 40Mha of land prone to this natural disaster (National Flood Commission, India). Significant loss of property, infrastructure, livestock, public utilities resulting in large economic losses due to floods are recurrent every year in many parts of India. Flood forecasting and early warning is widely recognized and adopted as non-structural measure to lower the damages caused by the flood events. Estimating the rainfall excess that results into excessive river flow is preliminary effort in riverine flood estimation. Flood forecasting models are in general, are event based and do not fully account for successive and persistent excessive surface runoff conditions. Successive high rainfall events result in saturated soil moisture conditions, favourable for high surface runoff conditions. The present study is to explore the usefulness of hydrological model derived surface runoff, running on continuous times-step, to relate to the occurrence of flood inundation due to persistent and successive high surface runoff conditions. Variable Infiltration Capacity (VIC), a macro-scale hydrological model, was used to simulate daily runoff at systematic grid level incorporating daily meteorological data and land cover data. VIC is a physically based, semi-distributed macroscale hydrological model that represents surface and subsurface hydrologic process on spatially distributed grid cell. It explicitly represents sub-grid heterogeneity in land cover classes, taking their phenological changes into account. In this study, the model was setup for entire India using geo-spatial data available from multiple sources (NRSC, NBSS&LUP, NOAA, and IMD) and was calibrated with river discharge data from CWC at selected river basins. Using the grid-wise surface runoff estimates from the model, an algorithm was developed through a set of thresholds of successive high runoff values in order to identify grids

  12. Spatiotemporal hazard mapping of a flood event "migration" in a transboundary river basin as an operational tool in flood risk management

    Science.gov (United States)

    Perrou, Theodora; Papastergios, Asterios; Parcharidis, Issaak; Chini, Marco

    2017-10-01

    Flood disaster is one of the heaviest disasters in the world. It is necessary to monitor and evaluate the flood disaster in order to mitigate the consequences. As floods do not recognize borders, transboundary flood risk management is imperative in shared river basins. Disaster management is highly dependent on early information and requires data from the whole river basin. Based on the hypothesis that the flood events over the same area with same magnitude have almost identical evolution, it is crucial to develop a repository database of historical flood events. This tool, in the case of extended transboundary river basins, could constitute an operational warning system for the downstream area. The utility of SAR images for flood mapping, was demonstrated by previous studies but the SAR systems in orbit were not characterized by high operational capacity. Copernicus system will fill this gap in operational service for risk management, especially during emergency phase. The operational capabilities have been significantly improved by newly available satellite constellation, such as the Sentinel-1A AB mission, which is able to provide systematic acquisitions with a very high temporal resolution in a wide swath coverage. The present study deals with the monitoring of a transboundary flood event in Evros basin. The objective of the study is to create the "migration story" of the flooded areas on the basis of the evolution in time for the event occurred from October 2014 till May 2015. Flood hazard maps will be created, using SAR-based semi-automatic algorithms and then through the synthesis of the related maps in a GIS-system, a spatiotemporal thematic map of the event will be produced. The thematic map combined with TanDEM-X DEM, 12m/pixel spatial resolution, will define the non- affected areas which is a very useful information for the emergency planning and emergency response phases. The Sentinels meet the main requirements to be an effective and suitable

  13. Detecting Recent Atmospheric River Induced Flood Events over the Russian River Basin

    Science.gov (United States)

    Mehran, A.; Lettenmaier, D. P.; Ralph, F. M.; Lavers, D. A.

    2015-12-01

    Almost all major flood events in the coastal Western U.S. occur as a result of multi-day extreme precipitation during the winter and late fall, and most such events are now known to be Atmospheric Rivers (ARs). AR events are defined as having integrated water vapor (IWV) exceeding 2 cm in an area at least 2000 km long and no more than 1000 km wide. The dominant moisture source in many AR events, including those associated with most floods in the Russian River basin in Northern California, is the tropics. We report on a hydrological analysis of selected floods in the Russian River basin using the Distributed Hydrology Soil Vegetation Model (DHSVM), forced alternately by gridded station data, NWS WSR-88D radar data, and output from a regional atmospheric model. We also report results of river state forecasts using a river hydrodynamics model to reconstruct flood inundation from selected AR events. We diagnose errors in both the hydrological and river stage predictions, and discuss alternatives for future error reduction.

  14. Impact of the new Sendai framework for disaster risk reduction on Paris flood prevention program

    Directory of Open Access Journals (Sweden)

    Thepot Regis

    2016-01-01

    Full Text Available The greater Paris region faces a significant risk of flooding due to potential spill-over from the Seine and the Marne. Because the last major flood occurred in 1910, the event has faded in the collective memory. Consequently, the population and the public authorities have difficulty imagining that such a catastrophe might repeat itself. In parallel, widespread urban expansion into flood zones has considerably aggravated the foreseeable damage if an event of a comparable intensity were to hit the region.In response to this situation, the EPTB Seine Grands Lacs – a public territorial basin establishment– decided to take action to reduce this risk.It began by commissioning a study from the OECD on flood risk prevention in the Seine Basin. This study was presented in January 2014 and highlighted the considerable risk of flooding in or near Paris, which could, affect a total of nearly 5 million people, cause up to €30 billion in direct damage and affect up to 400.000 jobs. It also put forward 14 recommendations that are being implemented by the public authorities, at either the national, basin or local level.The EPTB launched in partnership with the government a second initiative for which it steers and coordinates a coherent, balanced, relevant and gradual programme of 78 flood prevention actions. As a new post-2015 framework for disaster risk reduction was adopted in Sendai in March 2015 taking in account lessons learned during the 2005-2015 period, gaps identified and future challenges, this paper addresses the question of the impact of this new international framework on the implementation of the flood prevention of Paris region. One of the main points developed is the necessity to increase public awareness, to enhance disaster preparedness for effective response and to “build back better” in recovery rehabilitation and reconstruction.

  15. Climate Change Impacts on River Floods : Uncertainty and Adaptation

    NARCIS (Netherlands)

    Wang, L.

    2015-01-01

    The modelling frameworks, which include greenhouse gas emission scenarios, climate models, downscaling methods and hydrological models, are generally used to assess climate change impacts on river floods. In this research, the uncertainty associated with each component of the modelling framework is

  16. On the role of soil moisture in the generation of heavy rainfall during the Oder flood event in July 1997

    Directory of Open Access Journals (Sweden)

    Ha Thi Minh Ho-Hagemann

    2015-10-01

    Full Text Available Soil moisture–atmosphere feedbacks play an important role in the regional climate over many regions worldwide, not only for the mean climate but also for extreme events. Several studies have shown that the extent and severity of droughts and heat waves can be significantly impacted by dry or wet soil moisture conditions. To date, the impact of soil moisture on heavy rainfall events has been less frequently investigated. Thus, we consider the role of soil moisture in the formation of heavy rainfall using the Oder flood event in July 1997 as an example. Here, we used the regional climate model CCLM as an uncoupled standalone model and the coupled COSTRICE system, where CCLM is coupled with an ocean and a sea ice model over the Baltic and North Sea regions. The results from climate simulations over Europe show that the coupled model can capture the second phase (18–20 July of heavy rainfall that led to the Oder flood, while the uncoupled model does not. Sensitivity experiments demonstrate that the better performance of the coupled model can be attributed to the simulated soil moisture conditions in July 1997 in Central Europe, which were wetter for the coupled model than for the uncoupled model. This finding indicates that the soil moisture preceding the event significantly impacted the generation of heavy rainfall in this second phase. The better simulation in the coupled model also implies the added value that the atmosphere–ocean coupling has on the simulation of this specific extreme event. As none of the model versions captured the first phase (4–8 July, despite the differences in soil moisture, it can be concluded that the importance of soil moisture for the generation of heavy rainfall events strongly depends on the event and the general circulation pattern associated with it.

  17. Assessment of Flood Disaster Impacts in Cambodia: Implications for Rapid Disaster Response

    Science.gov (United States)

    Ahamed, Aakash; Bolten, John; Doyle, Colin

    2016-04-01

    Disaster monitoring systems can provide near real time estimates of population and infrastructure affected by sudden onset natural hazards. This information is useful to decision makers allocating lifesaving resources following disaster events. Floods are the world's most common and devastating disasters (UN, 2004; Doocy et al., 2013), and are particularly frequent and severe in the developing countries of Southeast Asia (Long and Trong, 2001; Jonkman, 2005; Kahn, 2005; Stromberg, 2007; Kirsch et al., 2012). Climate change, a strong regional monsoon, and widespread hydropower construction contribute to a complex and unpredictable regional hydrodynamic regime. As such, there is a critical need for novel techniques to assess flood impacts to population and infrastructure with haste during and following flood events in order to enable governments and agencies to optimize response efforts following disasters. Here, we build on methods to determine regional flood extent in near real time and develop systems that automatically quantify the socioeconomic impacts of flooding in Cambodia. Software developed on cloud based, distributed processing Geographic Information Systems (GIS) is used to demonstrate spatial and numerical estimates of population, households, roadways, schools, hospitals, airports, agriculture and fish catch affected by severe monsoon flooding occurring in the Cambodian portion of Lower Mekong River Basin in 2011. Results show modest agreement with government and agency estimates. Maps and statistics generated from the system are intended to complement on the ground efforts and bridge information gaps to decision makers. The system is open source, flexible, and can be applied to other disasters (e.g. earthquakes, droughts, landslides) in various geographic regions.

  18. Forest operations, extreme flooding events, and considerations for hydrologic modeling in the Appalachians--A review

    Science.gov (United States)

    M.A. Eisenbies; W.M. Aust; J.A. Burger; M.B. Adams

    2007-01-01

    The connection between forests and water resources is well established, but the relationships among controlling factors are only partly understood. Concern over the effects of forestry operations, particularly harvesting, on extreme flooding events is a recurrent issue in forest and watershed management. Due to the complexity of the system, and the cost of installing...

  19. Decision support system emergency planning, creating evacuation strategies in the event of flooding

    NARCIS (Netherlands)

    Windhouwer, C.J.; Klunder, G.A.; Sanders, F.M.

    2005-01-01

    The Decision Support System (DSS) Emergency Planning is designed for use in the event of sea or river flooding. It makes accessible all the information related to the decision whether to evacuate an area. An important factor in this decision is the time required for the evacuation. The model used by

  20. Environmental impacts of flood control measures in climate change adaptation strategies

    DEFF Research Database (Denmark)

    Brudler, Sarah; Arnbjerg-Nielsen, Karsten; Hauschild, Michael Zwicky

    (SSA), which uses only pipes and underground retention basins. To ensure comparability, flood safety levels for different rain events are defined, which have to be met in both scenarios. The environmental impacts are calculated for eight different categories, including climate change, resource...... it on the surface without harming assets. When evaluating different adaptation approaches, a cost assessment is typically carried out, while environmental impacts usually are not considered. To close this gap, a Life Cycle Assessment (LCA) based method is developed, which allows to quantify environmental impacts...... years and handling small events with a return period of up to 0.2 years cause by far the largest share of the total environmental impacts in both scenarios (up to 96% for the CMP, and up to 84% for the SSA. In contrast, measures aimed at handling extreme events with a return period of up to 100 years...

  1. Toward a coupled Hazard-Vulnerability Tool for Flash Flood Impacts Prediction

    Science.gov (United States)

    Terti, Galateia; Ruin, Isabelle; Anquetin, Sandrine; Gourley, Jonathan J.

    2015-04-01

    Flash floods (FF) are high-impact, catastrophic events that result from the intersection of hydrometeorological extremes and society at small space-time scales, generally on the order of minutes to hours. Because FF events are generally localized in space and time, they are very difficult to forecast with precision and can subsequently leave people uninformed and subject to surprise in the midst of their daily activities (e.g., commuting to work). In Europe, FFs are the main source of natural hazard fatalities, although they affect smaller areas than riverine flooding. In the US, also, flash flooding is the leading cause of weather-related deaths most years, with some 200 annual fatalities. There were 954 fatalities and approximately 31 billion U.S. dollars of property damage due to floods and flash floods from 1995 to 2012 in the US. For forecasters and emergency managers the prediction of and subsequent response to impacts due to such a sudden onset and localized event remains a challenge. This research is motivated by the hypothesis that the intersection of the spatio-temporal context of the hazard with the distribution of people and their characteristics across space and time reveals different paths of vulnerability. We argue that vulnerability and the dominant impact type varies dynamically throughout the day and week according to the location under concern. Thus, indices are appropriate to develop and provide, for example, vehicle-related impacts on active population being focused on the road network during morning or evening rush hours. This study describes the methodological developments of our approach and applies our hypothesis to the case of the June 14th, 2010 flash flood event in the Oklahoma City area (Oklahoma, US). Social (i.e. population socio-economic profile), exposure (i.e. population distribution, land use), and physical (i.e. built and natural environment) data are used to compose different vulnerability products based on the forecast location

  2. Leptospirosis Outbreak After the 2014 Major Flooding Event in Kelantan, Malaysia: A Spatial-Temporal Analysis.

    Science.gov (United States)

    Mohd Radi, Mohd Firdaus; Hashim, Jamal Hisham; Jaafar, Mohd Hasni; Hod, Rozita; Ahmad, Norfazilah; Mohammed Nawi, Azmawati Binti; Baloch, Gul Muhammad; Ismail, Rohaida; Farakhin Ayub, Nur Izzah

    2018-03-12

    Severe floods increase the risk of leptospirosis outbreaks in endemic areas. This study determines the spatial-temporal distribution of leptospirosis in relation to environmental factors after a major flooding event in Kelantan, Malaysia. We conducted a cross-sectional study involving incident leptospirosis cases, from the 3 months before, during, and three months after flood, in reference to the severe 2014 Kelantan flooding event. Geographical information system was used to determine the spatial distribution while climatic factors that influenced the cases were also analyzed. A total of 1,229 leptospirosis cases were notified within the three study periods where incidence doubled in the postflood period. Twelve of 78 subdistricts recorded incidence rates of over 100 per 100,000 population in the postflood periods, in comparison with only four subdistricts in the preflooding period. Average nearest neighborhood indicated that the cases were more clustered in the postflood period as compared with the preflood period, with observed mean distance of 1,138.8 meters and 1,665.7 meters, respectively (both at P floods.

  3. Coupled prediction of flash flood response and debris flow occurrence: Application on an alpine extreme flood event

    Science.gov (United States)

    Destro, Elisa; Amponsah, William; Nikolopoulos, Efthymios I.; Marchi, Lorenzo; Marra, Francesco; Zoccatelli, Davide; Borga, Marco

    2018-03-01

    The concurrence of flash floods and debris flows is of particular concern, because it may amplify the hazard corresponding to the individual generative processes. This paper presents a coupled modelling framework for the predictions of flash flood response and of the occurrence of debris flows initiated by channel bed mobilization. The framework combines a spatially distributed flash flood response model and a debris flow initiation model to define a threshold value for the peak flow which permits identification of channelized debris flow initiation. The threshold is defined over the channel network as a function of the upslope area and of the local channel bed slope, and it is based on assumptions concerning the properties of the channel bed material and of the morphology of the channel network. The model is validated using data from an extreme rainstorm that impacted the 140 km2 Vizze basin in the Eastern Italian Alps on August 4-5, 2012. The results show that the proposed methodology has improved skill in identifying the catchments where debris-flows are triggered, compared to the use of simpler thresholds based on rainfall properties.

  4. Nonstationarities in the occurrence rates of flood events in Portuguese watersheds

    Directory of Open Access Journals (Sweden)

    A. T. Silva

    2012-01-01

    Full Text Available An exploratory analysis on the variability of flood occurrence rates in 10 Portuguese watersheds is made, to ascertain if that variability is concurrent with the principle of stationarity. A peaks-over-threshold (POT sampling technique is applied to 10 long series of mean daily streamflows and to 4 long series of daily rainfall in order to sample the times of occurrence (POT time data of the peak values of those series. The kernel occurrence rate estimator, coupled with a bootstrap approach, was applied to the POT time data to obtain the time dependent estimated occurrence rate curves, λˆ(t, of floods and extreme rainfall events. The results of the analysis show that the occurrence of those events constitutes an inhomogeneous Poisson process, hence the occurrence rates are nonstationary. An attempt was made to assess whether the North Atlantic Oscillation (NAO casted any influence on the occurrence rate of floods in the study area. Although further research is warranted, it was found that years with a less-than-average occurrence of floods tend to occur when the winter NAO is in the positive phase, and years with a higher occurrence of floods (more than twice the average tend to occur when the winter NAO is in the negative phase. Although the number of analyzed watersheds and their uneven spatial distribution hinders the generalization of the findings to the country scale, the authors conclude that the mathematical formulation of the flood frequency models relying on stationarity commonly employed in Portugal should be revised in order to account for possible nonstationarities in the occurrence rates of such events.

  5. Telling and measuring urban floods: event reconstruction by means of public-domain media

    Science.gov (United States)

    Macchia, S.; Gallo, E.; Claps, P.

    2012-04-01

    In the last decade, the diffusion of mobile telephones and ond of low-cost digital cameras have changed the public approach to catastrophes. As regards floods, it has become widespread the availability of images and videos taken in urban areas. Searching into Youtube or Youreporter, for example, one can understand how often citizen are considering to report even scary events. Nowadays these amateurs videos are often used in news world reports, which often increase or dampen the public perception of flood risk. More importantly, these amateur videos can play a crucial role in a didactic and technical representation of media flooding problems. The question so arise: why don't use the amateur videos for civil protection purposes? This work shows a new way to use flood images and videos to obtain technical data and spread safety information. Specifically, we show how to determine the height and speed of water flow, which have been achieved in some places during Genoa flood - 4th November 2011 - For this event we have downloaded more than 50 videos from different websites, where the authors have provided information about the time of recording, the geographical coordinates and the height above ground of the point of recording. The support by Google tools, such as Google maps and StreetWiew © has allowed us to geographically locate the recording points, so to put together shots and slides necessary to put together a whole reconstruction of the event. Future research will be in the direction of using these videos to generate a tool for the Google platforms, in order to address an easily achievable, yet accurate, information to the public, so to warn people on how to behave in front of imminent floods.

  6. Lightning activity, rainfall and flash flooding – occasional or interrelated events? A case study in the island of Crete

    Directory of Open Access Journals (Sweden)

    A. G. Koutroulis

    2012-04-01

    Full Text Available The majority of cyclones passing over Crete in late autumn to early winter originate from southwest, west and northwest and are of varying size and intensity. A number of these cyclones cause flash floods. The present study reports the possible relationships between lighting activity and high precipitation related to flash flood events. In this study an attempt was made to correlate the lightning number and location, recorded by the ZEUS lightning detection system, with the rainfall characteristics for sixteen rain events (4 flood and 12 non-flood events on the island of Crete, during the period 2008–2009. Spatiotemporal analysis of rain and rain rate with flash count was performed with respect to distance (radius of flashes from raingauge location at various temporal scales, in order to examine the correlation of accumulated rainfall and lightning activity. The maximum attained statistical significant correlation was obtained within a circular area of an average radius of 15 km around the raingauge, and an average time lag of flash count prior precipitation accumulation of 15 min. The maximum correlation between the lightning and rainfall data is obtained for shorter time lags for the flood events (15 min than the non-flood events (25 min, that could reflect the faster propagation of flood triggering storms due to high convective activity. Results show increased lightning activity occurring during flood triggering storms, by an average of four times higher. Furthermore, there is evidence that the number of flashes that occur during a precipitation event is related to precipitation depth when the latter is adequate to produce a flood event. Differences between flood and non-flood producing storms need to be further assessed by analyzing more independent parameters, including the synoptic conditions and dominant flash flood hydrological generating processes.

  7. Psychosocial impact of the summer 2007 floods in England

    Science.gov (United States)

    2011-01-01

    Background The summer of 2007 was the wettest in the UK since records began in 1914 and resulted in severe flooding in several regions. We carried out a health impact assessment using population-based surveys to assess the prevalence of and risk factors for the psychosocial consequences of this flooding in the United Kingdom. Methods Surveys were conducted in two regions using postal, online, telephone questionnaires and face-to-face interviews. Exposure variables included the presence of flood water in the home, evacuation and disruption to essential services (incident management variables), perceived impact of the floods on finances, house values and perceived health concerns. Validated tools were used to assess psychosocial outcome (mental health symptoms): psychological distress (GHQ-12), anxiety (GAD-7), depression (PHQ-9) and probable post-traumatic stress disorder (PTSD checklist-shortform). Multivariable logistic regression was used to describe the association between water level in the home, psychological exposure variables and incident management variables, and each mental health symptom, adjusted for age, sex, presence of an existing medical condition, employment status, area and data collection method. Results The prevalence of all mental health symptoms was two to five-fold higher among individuals affected by flood water in the home. People who perceived negative impact on finances were more likely to report psychological distress (OR 2.5, 1.8-3.4), probable anxiety (OR 1.8, 1.3-2.7) probable depression (OR 2.0, 1.3-2.9) and probable PTSD (OR 3.2, 2.0-5.2). Disruption to essential services increased adverse psychological outcomes by two to three-fold. Evacuation was associated with some increase in psychological distress but not significantly for the other three measures. Conclusion The psychosocial and mental health impact of flooding is a growing public health concern and improved strategies for minimising disruption to essential services and

  8. National water summary 1988-89: Hydrologic events and floods and droughts

    Science.gov (United States)

    Paulson, Richard W.; Chase, Edith B.; Roberts, Robert S.; Moody, David W.

    1991-01-01

    National Water Summary 1988-89 - Hydrologic Events and Floods and Droughts documents the occurrence in the United States, Puerto Rico, and the U.S. Virgin Islands of two types of extreme hydrologic events floods and droughts on the basis of analysis of stream-discharge data. This report details, for the first time, the areal extent of the most notable floods and droughts in each State, portrays their severity in terms of annual peak discharge for floods and annual departure from long-term discharge for droughts for selected stream-gaging stations, and estimates how frequently floods and droughts of such severity can be expected to recur. These two types of extreme hydrologic events are very different in their duration, cause, areal extent, and effect on human activities. Floods are short-term phenomena that typically last only a few hours to a few days and are associated with weather systems that produce unusually large amounts of rain or that cause snow to melt quickly. The large amount of runoff produced causes rivers to overflow their banks and, thus, is highly dangerous to human life and property. In contrast, droughts are long-term phenomena that typically persist for months to a decade or more and are associated with the absence of precipitation producing weather. They affect large geographic areas that can be statewide, regional, or even nationwide in extent. Droughts can cause great economic hardship and even loss of life in developing countries, although the loss of life results almost wholly from diminished water supplies and catastrophic crop failures rather than from the direct and obvious peril to human life that is common to floods. The following discussion is an overview of the three parts of this 1988-89 National Water Summary "Hydrologic Conditions and Water-Related Events, Water Years 1988-89," "Hydrologic Perspectives on Water Issues," and "State Summaries of Floods and Droughts." Background information on sources of atmospheric moisture to the

  9. Impacts of calibration strategies and ensemble methods on ensemble flood forecasting over Lanjiang basin, Southeast China

    Science.gov (United States)

    Liu, Li; Xu, Yue-Ping

    2017-04-01

    Ensemble flood forecasting driven by numerical weather prediction products is becoming more commonly used in operational flood forecasting applications.In this study, a hydrological ensemble flood forecasting system based on Variable Infiltration Capacity (VIC) model and quantitative precipitation forecasts from TIGGE dataset is constructed for Lanjiang Basin, Southeast China. The impacts of calibration strategies and ensemble methods on the performance of the system are then evaluated.The hydrological model is optimized by parallel programmed ɛ-NSGAII multi-objective algorithm and two respectively parameterized models are determined to simulate daily flows and peak flows coupled with a modular approach.The results indicatethat the ɛ-NSGAII algorithm permits more efficient optimization and rational determination on parameter setting.It is demonstrated that the multimodel ensemble streamflow mean have better skills than the best singlemodel ensemble mean (ECMWF) and the multimodel ensembles weighted on members and skill scores outperform other multimodel ensembles. For typical flood event, it is proved that the flood can be predicted 3-4 days in advance, but the flows in rising limb can be captured with only 1-2 days ahead due to the flash feature. With respect to peak flows selected by Peaks Over Threshold approach, the ensemble means from either singlemodel or multimodels are generally underestimated as the extreme values are smoothed out by ensemble process.

  10. Impacts of repetitive floods and satisfaction with flood relief efforts: A case study of the flood-prone districts in Thailand’s Ayutthaya province

    Directory of Open Access Journals (Sweden)

    Nawhath Thanvisitthpon

    2017-01-01

    Full Text Available This research investigates the impacts of the repetitive flooding on the inhabitants of the four flood-prone districts in Thailand’s central province of Ayutthaya: Pranakorn Si Ayutthaya, Sena, Bang Ban, and Pak Hai. In addition, the residents’ satisfaction levels with the flood relief efforts and operations of the local authorities were examined and analyzed. The research revealed that most local residents have adapted to co-exist with the repetitive floods, an example of which is the elevation of the houses a few meters above the ground where the living quarter is on the upper level. The findings also indicated that the repetitive flooding incurred substantial post-flood repair costs, in light of the low income-earning capabilities of the locals. However, the flood-recovery financial aids was incommensurate with the actual expenditures, contributing to the lowest average satisfaction score among the inhabitants with regard to the adequacy of the post-flood repair and restoration financial aid. Furthermore, the research identified the differences between districts on the satisfaction with the flood relief efforts. The disparity could be attributed to the extent of coordination and participation of the local residents and their local leaders in the flood-related measures.

  11. Anticipated climate change impacts on flood characteristics : Moisie River application

    International Nuclear Information System (INIS)

    Dore, I.; Desrochers, G.E.; Roy, R.; Chaumont, D.

    2006-01-01

    The issue of global warming was discussed with particular reference to the changes that may occur in the hydrological regime within the coming decades in response to predicted changes in climate. Flood events for the 2050 time horizon were investigated along with the consequences on water management and dam safety. Dams operated by Hydro-Quebec are used for flood control, water supply, recreational activities and hydroelectricity. As such, the electric utility relies on methods to evaluate the adaptability of current management plans to climate change. This paper presented the results of a study conducted at the Moisie River watershed, located in northern Quebec. The HSAMI hydrologic model was used to evaluate and compare the occurrences where stream flows and water levels exceed critical values in order to assess the effectiveness of management plans in both current and climate change scenarios. The study considered two different approaches on existing and future anticipated meteorological scenarios based on different criteria. The purpose was to optimize future hydroelectric generation, reduce floods and improve the safety of hydraulic structures. Preliminary results suggest a possible increase in flood risk and fewer low water level occurrences. 7 refs., 2 tabs., 6 figs

  12. A prospective study of the impact of floods on the mental and physical health of older adults.

    Science.gov (United States)

    Bei, Bei; Bryant, Christina; Gilson, Kim-Michelle; Koh, Juliana; Gibson, Penelope; Komiti, Angela; Jackson, Henry; Judd, Fiona

    2013-01-01

    With a longitudinal prospective design, we examined the impact of floods on the mental and physical health of older adults and explored risk and protective factors. Two hundred and seventy four older adults (age ≥60) completed surveys before and after a flood event. Both the surveys included measures of anxiety, depression, self-reported health, and satisfaction with life; the post-flood survey also included questionnaires on flood experience, symptoms of post-traumatic stress disorder (PTSD), stoicism, and psychological coping with floods. Compared to those not personally affected (78.8%), personally affected individuals (21.2%) reported significantly higher PTSD symptoms, with about one in six reporting PTSD symptoms that might require clinical attention. Personally affected individuals also reported a greater increase in anxiety post-flood, but changes in their depressive symptoms and self-reported health were not significantly different from those not personally affected. Greater flood exposure and the lack of social support were the risk factors for poorer mental and physical health. Higher stoicism was associated with higher post-flood depression and poorer self-reported mental health. The use of maladaptive coping, such as venting and distraction, was associated with greater deterioration in mental health after floods, whilst emotion-focused coping such as acceptance, positive reframing, and humour, was protective against such deterioration. Floods had adverse psychological impacts on some older adults who were personally affected. Despite the evidence of resilience, a small proportion of older adults experienced significant difficulties after the floods. The findings in this study help understand older adults' psychological responses to disasters and have practical implications for service planning and delivery.

  13. Projected large flood event sensitivity to projection selection and temporal downscaling methodology

    International Nuclear Information System (INIS)

    Raff, D.

    2008-01-01

    Large flood events, that influence regulatory guidelines as well as safety of dams decisions, are likely to be affected by climate change. This talk will evaluate the use of climate projections downscaled and run through a rainfall - runoff model and its influence on large flood events. The climate spatial downscaling is performed statistically and a re-sampling and scaling methodology is used to temporally downscale from monthly to daily signals. The signals are run through a National Weather Service operational rainfall-runoff model to produce 6-hour flows. The flows will be evaluated for changes in large events at look-ahead horizons from 2011 - 2040, 2041 - 2070, and 2071 - 2099. The sensitivity of results will be evaluated with respect to projection selection criteria and re-sampling and scaling criteria for the Boise River in Idaho near Lucky Peak Dam. (author)

  14. Seepage patterns of Diuron in a ditch bed during a sequence of flood events

    Energy Technology Data Exchange (ETDEWEB)

    Dages, C., E-mail: cecile.dages@supagro.inra.fr; Samouëlian, A.; Negro, S.; Storck, V.; Huttel, O.; Voltz, M.

    2015-12-15

    Although ditches limit surface water contamination, groundwater recharge through ditches in Mediterranean catchments may result in groundwater contamination. We analysed the dynamics of pesticide percolation in ditches by conducting an original lab experiment that mimicked the successive percolation processes that occur during a flood season. Nine successive percolation events were operated on an undisturbed soil column collected from a ditch bed. The infiltrating water was doped with {sup 14}C-Diuron at concentrations that were chosen to decrease between the events so as to correspond to values observed during actual flood events. The water and solute fluxes were monitored during each event, and the final extractable and non-extractable Diuron residues in the column were determined. Two main observations were made. First, a high leaching potential was observed through the ditch bed over a succession of infiltrating flood events, with 58.9% of the infiltrated Diuron and its metabolites leaching. Second, compared with the contamination of surface water circulating in the ditches, the contamination of seepage water exhibited smaller peak values and persisted much longer because of the desorption of Diuron residues stored in the ditch bed. Thus, ditches serve as buffering zones between surface and groundwater. However, compared with field plots, ditches appear to be a preferential location for the percolation of pesticides into groundwater at the catchment scale. - Highlights: • Diuron percolation in a ditch bed during flood events was mimicked in a column setup. • Diuron percolation can represent up to 50% of the infiltrated Diuron. • The ditch bed exhibits a high buffering capacity due to its high sorption properties. • Contamination period of percolation water lasts longer than that of infiltrating water. • Diuron residues stored in ditch bed move deeper than in field topsoils.

  15. Seepage patterns of Diuron in a ditch bed during a sequence of flood events

    International Nuclear Information System (INIS)

    Dages, C.; Samouëlian, A.; Negro, S.; Storck, V.; Huttel, O.; Voltz, M.

    2015-01-01

    Although ditches limit surface water contamination, groundwater recharge through ditches in Mediterranean catchments may result in groundwater contamination. We analysed the dynamics of pesticide percolation in ditches by conducting an original lab experiment that mimicked the successive percolation processes that occur during a flood season. Nine successive percolation events were operated on an undisturbed soil column collected from a ditch bed. The infiltrating water was doped with 14 C-Diuron at concentrations that were chosen to decrease between the events so as to correspond to values observed during actual flood events. The water and solute fluxes were monitored during each event, and the final extractable and non-extractable Diuron residues in the column were determined. Two main observations were made. First, a high leaching potential was observed through the ditch bed over a succession of infiltrating flood events, with 58.9% of the infiltrated Diuron and its metabolites leaching. Second, compared with the contamination of surface water circulating in the ditches, the contamination of seepage water exhibited smaller peak values and persisted much longer because of the desorption of Diuron residues stored in the ditch bed. Thus, ditches serve as buffering zones between surface and groundwater. However, compared with field plots, ditches appear to be a preferential location for the percolation of pesticides into groundwater at the catchment scale. - Highlights: • Diuron percolation in a ditch bed during flood events was mimicked in a column setup. • Diuron percolation can represent up to 50% of the infiltrated Diuron. • The ditch bed exhibits a high buffering capacity due to its high sorption properties. • Contamination period of percolation water lasts longer than that of infiltrating water. • Diuron residues stored in ditch bed move deeper than in field topsoils.

  16. Trends in water level and flooding in Dhaka, Bangladesh and their impact on mortality.

    Science.gov (United States)

    Thiele-Eich, Insa; Burkart, Katrin; Simmer, Clemens

    2015-01-22

    Climate change is expected to impact flooding in many highly populated coastal regions, including Dhaka (Bangladesh), which is currently among the fastest growing cities in the world. In the past, high mortality counts have been associated with extreme flood events. We first analyzed daily water levels of the past 100 years in order to detect potential shifts in extremes. A distributed lag non-linear model was then used to examine the connection between water levels and mortality. Results indicate that for the period of 2003-2007, which entails two major flood events in 2004 and 2007, high water levels do not lead to a significant increase in relative mortality, which indicates a good level of adaptation and capacity to cope with flooding. However, following low water levels, an increase in mortality could be found. As our trend analysis of past water levels shows that minimum water levels have decreased during the past 100 years, action should be taken to ensure that the exposed population is also well-adapted to drought.

  17. Trends in Water Level and Flooding in Dhaka, Bangladesh and Their Impact on Mortality

    Directory of Open Access Journals (Sweden)

    Insa Thiele-Eich

    2015-01-01

    Full Text Available Climate change is expected to impact flooding in many highly populated coastal regions, including Dhaka (Bangladesh, which is currently among the fastest growing cities in the world. In the past, high mortality counts have been associated with extreme flood events. We first analyzed daily water levels of the past 100 years in order to detect potential shifts in extremes. A distributed lag non-linear model was then used to examine the connection between water levels and mortality. Results indicate that for the period of 2003–2007, which entails two major flood events in 2004 and 2007, high water levels do not lead to a significant increase in relative mortality, which indicates a good level of adaptation and capacity to cope with flooding. However, following low water levels, an increase in mortality could be found. As our trend analysis of past water levels shows that minimum water levels have decreased during the past 100 years, action should be taken to ensure that the exposed population is also well-adapted to drought.

  18. Methodological Framework for Analysing Cascading Effects from Flood Events: The Case of Sukhumvit Area, Bangkok, Thailand

    Directory of Open Access Journals (Sweden)

    Geofrey Hilly

    2018-01-01

    Full Text Available Impacts from floods in urban areas can be diverse and wide ranging. These can include the loss of human life, infrastructure and property damages, as well as other kinds of nuisance and inconvenience to urban life. Hence, the ability to identify and quantify wider ranging effects from floods is of the utmost importance to urban flood managers and infrastructure operators. The present work provides a contribution in this direction and describes a methodological framework for analysing cascading effects from floods that has been applied for the Sukhumvit area in Bangkok (Thailand. It demonstrates that the effects from floods can be much broader in their reach and magnitude than the sole impacts incurred from direct and immediate losses. In Sukhumvit, these include loss of critical services, assets and goods, traffic congestion and delays in transportation, loss of business and income, disturbances and discomfort to the residents, and all these can be traced with the careful analysis of cascading effects. The present work explored the use of different visualization options to present the findings. These include a casual loop diagram, a HAZUR resilience map, a tree diagram and GIS maps.

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

    Science.gov (United States)

    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.

  20. Impacts of European drought events

    NARCIS (Netherlands)

    Stahl, Kerstin; Kohn, Irene; Blauhut, Veit; Loon, Van Anne F.; Melsen, Lieke A.; Lanen, van Henny A.J.

    2016-01-01

    Drought is a natural hazard that can cause a wide range of impacts affecting the environment, society, and the economy. Providing an impact assessment and reducing vulnerability to these impacts for regions beyond the local scale, spanning political and sectoral boundaries, requires systematic

  1. Five perspectives on ranking two severe flash flood events in Switzerland

    Science.gov (United States)

    Liechti, Katharina; Zappa, Massimiliano; Turowski, Jens Martin

    2010-05-01

    In June 2007 the atmospheric conditions above Switzerland were characterized by flat pressure gradients that triggered several stable and spatially limited convective rainfall events. We analyse two such events, which are particularly well documented. The studied sites are the Langeten catchment in Canton Berne and the Einsiedeln region with the Alp and Minster sub-catchments in the Canton Schwyz in Switzerland. The events have been analyzed from five different perspectives: a) Estimation of the economic value of the damages on the basis of the Swiss flood and landslide damage database; b) Analysis of the daily, hourly and 10-minutes precipitation with extreme-value statistics (GEV); c) Analysis of the hourly and 10 minutes discharge rates from nested basins with GEV; d) GEV analysis of sediment transport in the Erlenbach basin using Geophone data. e) Hind casting the events with the hydrological model PREVAH using operationally available quantitative precipitation estimates from both pluviometers and weather radar. For all time series analysed with GEV the two events rank amongst the most severe in their respective regions, and were responsible for the highest damage costs. The estimated return periods for the event in the Langeten catchment were > 100 y for the 10 minute runoff and 70 y for daily precipitation. For the Alp catchment the return periods were estimated to 70 y for 10 minute runoff, 35-40 y for 10 minute precipitation and 55 y for sediment transport. The results illustrate known problems with extreme value analysis, such as the occurrence of threshold processes in runoff generation. Hydrological prediction of flash flood events can be improved if weather radar observations are used to constrain the precipitation events. However, the quality that can ultimately be achieved depends on the extent of the thunderstorm, and on the spatial and temporal resolution of the radar measurements. A possible route for improvements may lie in the combination of

  2. A Flood Detection and Mapping Algorithm Using MODIS Data: Assessment of Extreme Flooding Events in Eastern Ganga Plains (2000-2015)

    Science.gov (United States)

    Sprigg, W. A.; Patel, S.; Prasad, A. K.; Sarkar, B. C.

    2015-12-01

    Flood, a hydrological extreme, is a dominant and frequent phenomena over the eastern Ganga Plains comprising of alluvial plains of Bihar and adjoining Nepal Himalaya. Flood affects major parts of Bihar where Gandak and Koshi are the major tributaries of Ganga River causing inundation during the monsoon season. Due to heavy rainfall in the Eastern Himalaya and adjoining regions, the river discharge increases several folds causing severe flood in plains. Moderate Resolution Imaging Spectroradiometer (MODIS) derived data at 250 m resolution (year 2000-2015) have been used to identify flood water and calculate daily water fraction (water cover) using model adopted from previous studies. During the monsoon season, cloud cover in daily images is found to be extremely high leading to lot of gaps in the form of missing data. To account for missing grid cell values, an adaptive polynomial filter (Savitzky-Golay) have been used to fit the time series of daily data for each grid cell. The missing values in daily images have been filled with calculated values to create daily time series of flood water. Landsat data at 30 m grid resolution have been used to verify flood water detection algorithm used in this study. Time series analysis of satellite derived data reveal a strong spatial and temporal variation in the extent, duration and frequency (inter-annual and intra-annual) of flooding event over the study region. Statistical analysis of IDF (intensity, duration, and frequency) and trend have been carried out to identify regions which show greater flood risk. Reoccurrence interval and length of flooding event in the study region is found to be high compared to other river basins in the western India. Based on the historical occurrence of flood, the study area have been classified into different flood hazard zones where flood mitigation and management need to be prioritized. MODIS based flood monitoring and mapping model used in this study can be used for monitoring and

  3. Enhanced transfer of terrestrially derived carbon to the atmosphere in a flooding event

    Science.gov (United States)

    Bianchi, Thomas S.; Garcia-Tigreros, Fenix; Yvon-Lewis, Shari A.; Shields, Michael; Mills, Heath J.; Butman, David; Osburn, Christopher; Raymond, Peter A.; Shank, G. Christopher; DiMarco, Steven F.; Walker, Nan; Kiel Reese, Brandi; Mullins-Perry, Ruth; Quigg, Antonietta; Aiken, George R.; Grossman, Ethan L.

    2013-01-01

    Rising CO2 concentration in the atmosphere, global climate change, and the sustainability of the Earth's biosphere are great societal concerns for the 21st century. Global climate change has, in part, resulted in a higher frequency of flooding events, which allow for greater exchange between soil/plant litter and aquatic carbon pools. Here we demonstrate that the summer 2011 flood in the Mississippi River basin, caused by extreme precipitation events, resulted in a “flushing” of terrestrially derived dissolved organic carbon (TDOC) to the northern Gulf of Mexico. Data from the lower Atchafalaya and Mississippi rivers showed that the DOC flux to the northern Gulf of Mexico during this flood was significantly higher than in previous years. We also show that consumption of radiocarbon-modern TDOC by bacteria in floodwaters in the lower Atchafalaya River and along the adjacent shelf contributed to northern Gulf shelf waters changing from a net sink to a net source of CO2 to the atmosphere in June and August 2011. This work shows that enhanced flooding, which may or may not be caused by climate change, can result in rapid losses of stored carbon in soils to the atmosphere via processes in aquatic ecosystems.

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

    Science.gov (United States)

    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.

  5. Flooding

    Science.gov (United States)

    ... have high levels of raw sewage or other hazardous substances. Early symptoms from exposure to contaminated flood water ... for commercial building and school maintenance. Basic mold hazards . ... and the waste management options available. Burying or burning is no longer ...

  6. Nonstationarity in the occurrence rate of floods in the Tarim River basin, China, and related impacts of climate indices

    Science.gov (United States)

    Gu, Xihui; Zhang, Qiang; Singh, Vijay P.; Chen, Xi; Liu, Lin

    2016-07-01

    Amplification of floods in the Xinjiang, China, has been observed, but reports on their changing properties and underlying mechanisms are not available. In this study, occurrence rates of floods in the Tarim River basin, the largest inland arid river basin in China, were analyzed using the Kernel density estimation technique and bootstrap resampling method. Also analyzed were the occurrence rates of precipitation extremes using the POT (Peak over Threshold)-based sampling method. Both stationary and non-stationary models were developed using GAMLSS (Generalized Additive Models for Location, Scale and Shape) to model flood frequency with time, climate index, precipitation and temperature as major predictors. Results indicated: (1) two periods with increasing occurrence of floods, i.e., the late 1960s and the late 1990s with considerable fluctuations around 2-3 flood events during time intervals between the late 1960s and the late 1990s; (2) changes in the occurrence rates of floods were subject to nonstationarity. A persistent increase of flood frequency and magnitude was observed during the 1990s and reached a peak value; (3) AMO (Atlantic Multidecadal Oscillation) and AO (Atlantic Oscillation) in winter were the key influencing climate indices impacting the occurrence rates of floods. However, NAO (North Atlantic Oscillation) and SOI (South Oscillation Index) are two principle factors that influence the occurrence rates of regional floods. The AIC (Akaike Information Criterion) values indicated that compared to the influence of climate indices, occurrence rates of floods seemed to be more sensitive to temperature and precipitation changes. Results of this study are important for flood management and development of mitigation measures.

  7. An Innovative Method for Flood Peak Event Separation from Discharge Time Series

    Science.gov (United States)

    Borzì, Iolanda; Bonaccorso, Brunella; Viglione, Alberto; Tito Aronica, Giuseppe

    2017-04-01

    In extreme value theory, Peak Over Threshold (POT) method is recognized to make a better use of available data with respect to Block Maxima (BM) method, as it allows to retain all relevant observations for frequency analysis, provided that an appropriate threshold is selected. Definition of a proper threshold, able to identify independent events, is in general a critical issue. In addition, in many hydrological applications, such as flood frequency analysis, threshold levels are usually site-specific. This could be a strong limitation when comparing the flood responses of different river basins within a large geographical area. In the present study, an attempt is made to develop a relatively simple criterion for the determination of different thresholds to separate relevant flood events from a large dataset of daily discharge time series recorded at European scale. The proposed method arises from the theory of stochastic processes in the frequency domain, which can provide a meaningful description of the characteristics of the series. In particular, from the analysis of the power spectral density function and the signal of the process (e.g. narrowband or broadband), it is possible to define crossings (i.e. peaks) in clusters or independent crossings of the threshold. More specifically, such a selection process of significant events may help to understand whether relatively close peaks can be referred to a single flood event or independent events. Also in the frequency domain, a mean frequency of the random process can be defined for each series to be used as a possible common criterion for the definition of the different thresholds for flood peaks selection. The advantages of this method compared to other methods, such as traditional POT, lie in the fact that it establishes a robust procedure for the separation of independent events in time series, by means of the analysis in the frequency domain. Furthermore, the choice of the threshold for the selection of

  8. Modelling the impact of land subsidence on urban pluvial flooding: A case study of downtown Shanghai, China.

    Science.gov (United States)

    Yin, Jie; Yu, Dapeng; Wilby, Rob

    2016-02-15

    This paper presents a numerical analysis of pluvial flooding to evaluate the impact of land subsidence on flood risks in urban contexts using a hydraulic model (FloodMap-HydroInundation2D). The pluvial flood event of August 2011 in Shanghai, China is used for model calibration and simulation. Evolving patterns of inundation (area and depth) are assessed over four time periods (1991, 1996, 2001 and 2011) for the downtown area, given local changes in topography and rates of land subsidence of up to 27 mm/yr. The results show that land subsidence can lead to non-linear response of flood characteristics. However, the impact on flood depths is generally minor (subsidence and micro-topographic variations at the local scale. Nonetheless, the modelling approach tested here may be applied to other cities where there are more marked rates of subsidence and/or greater heterogeneity in the depressed urban surface. In these cases, any identified hot-spots of subsidence and focusing of pluvial flooding may be targeted for adaptation interventions. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Physiologically-based toxicokinetic models help identifying the key factors affecting contaminant uptake during flood events

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, Markus; Eichbaum, Kathrin [Department of Ecosystem Analysis, Institute for Environmental Research,ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); Kammann, Ulrike [Thünen-Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany); Hudjetz, Sebastian [Department of Ecosystem Analysis, Institute for Environmental Research,ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); Institute of Hydraulic Engineering and Water Resources Management, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52056 Aachen (Germany); Cofalla, Catrina [Institute of Hydraulic Engineering and Water Resources Management, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52056 Aachen (Germany); Buchinger, Sebastian; Reifferscheid, Georg [Federal Institute of Hydrology (BFG), Department G3: Biochemistry, Ecotoxicology, Am Mainzer Tor 1, 56068 Koblenz (Germany); Schüttrumpf, Holger [Institute of Hydraulic Engineering and Water Resources Management, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52056 Aachen (Germany); Preuss, Thomas [Department of Environmental Biology and Chemodynamics, Institute for Environmental Research,ABBt- Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); and others

    2014-07-01

    Highlights: • A PBTK model for trout was coupled with a sediment equilibrium partitioning model. • The influence of physical exercise on pollutant uptake was studies using the model. • Physical exercise during flood events can increase the level of biliary metabolites. • Cardiac output and effective respiratory volume were identified as relevant factors. • These confounding factors need to be considered also for bioconcentration studies. - Abstract: As a consequence of global climate change, we will be likely facing an increasing frequency and intensity of flood events. Thus, the ecotoxicological relevance of sediment re-suspension is of growing concern. It is vital to understand contaminant uptake from suspended sediments and relate it to effects in aquatic biota. Here we report on a computational study that utilizes a physiologically based toxicokinetic model to predict uptake, metabolism and excretion of sediment-borne pyrene in rainbow trout (Oncorhynchus mykiss). To this end, data from two experimental studies were compared with the model predictions: (a) batch re-suspension experiments with constant concentration of suspended particulate matter at two different temperatures (12 and 24 °C), and (b) simulated flood events in an annular flume. The model predicted both the final concentrations and the kinetics of 1-hydroxypyrene secretion into the gall bladder of exposed rainbow trout well. We were able to show that exhaustive exercise during exposure in simulated flood events can lead to increased levels of biliary metabolites and identified cardiac output and effective respiratory volume as the two most important factors for contaminant uptake. The results of our study clearly demonstrate the relevance and the necessity to investigate uptake of contaminants from suspended sediments under realistic exposure scenarios.

  10. Physiologically-based toxicokinetic models help identifying the key factors affecting contaminant uptake during flood events

    International Nuclear Information System (INIS)

    Brinkmann, Markus; Eichbaum, Kathrin; Kammann, Ulrike; Hudjetz, Sebastian; Cofalla, Catrina; Buchinger, Sebastian; Reifferscheid, Georg; Schüttrumpf, Holger; Preuss, Thomas

    2014-01-01

    Highlights: • A PBTK model for trout was coupled with a sediment equilibrium partitioning model. • The influence of physical exercise on pollutant uptake was studies using the model. • Physical exercise during flood events can increase the level of biliary metabolites. • Cardiac output and effective respiratory volume were identified as relevant factors. • These confounding factors need to be considered also for bioconcentration studies. - Abstract: As a consequence of global climate change, we will be likely facing an increasing frequency and intensity of flood events. Thus, the ecotoxicological relevance of sediment re-suspension is of growing concern. It is vital to understand contaminant uptake from suspended sediments and relate it to effects in aquatic biota. Here we report on a computational study that utilizes a physiologically based toxicokinetic model to predict uptake, metabolism and excretion of sediment-borne pyrene in rainbow trout (Oncorhynchus mykiss). To this end, data from two experimental studies were compared with the model predictions: (a) batch re-suspension experiments with constant concentration of suspended particulate matter at two different temperatures (12 and 24 °C), and (b) simulated flood events in an annular flume. The model predicted both the final concentrations and the kinetics of 1-hydroxypyrene secretion into the gall bladder of exposed rainbow trout well. We were able to show that exhaustive exercise during exposure in simulated flood events can lead to increased levels of biliary metabolites and identified cardiac output and effective respiratory volume as the two most important factors for contaminant uptake. The results of our study clearly demonstrate the relevance and the necessity to investigate uptake of contaminants from suspended sediments under realistic exposure scenarios

  11. Flood modelling with a distributed event-based parsimonious rainfall-runoff model: case of the karstic Lez river catchment

    Directory of Open Access Journals (Sweden)

    M. Coustau

    2012-04-01

    Full Text Available Rainfall-runoff models are crucial tools for the statistical prediction of flash floods and real-time forecasting. This paper focuses on a karstic basin in the South of France and proposes a distributed parsimonious event-based rainfall-runoff model, coherent with the poor knowledge of both evaporative and underground fluxes. The model combines a SCS runoff model and a Lag and Route routing model for each cell of a regular grid mesh. The efficiency of the model is discussed not only to satisfactorily simulate floods but also to get powerful relationships between the initial condition of the model and various predictors of the initial wetness state of the basin, such as the base flow, the Hu2 index from the Meteo-France SIM model and the piezometric levels of the aquifer. The advantage of using meteorological radar rainfall in flood modelling is also assessed. Model calibration proved to be satisfactory by using an hourly time step with Nash criterion values, ranging between 0.66 and 0.94 for eighteen of the twenty-one selected events. The radar rainfall inputs significantly improved the simulations or the assessment of the initial condition of the model for 5 events at the beginning of autumn, mostly in September–October (mean improvement of Nash is 0.09; correction in the initial condition ranges from −205 to 124 mm, but were less efficient for the events at the end of autumn. In this period, the weak vertical extension of the precipitation system and the low altitude of the 0 °C isotherm could affect the efficiency of radar measurements due to the distance between the basin and the radar (~60 km. The model initial condition S is correlated with the three tested predictors (R2 > 0.6. The interpretation of the model suggests that groundwater does not affect the first peaks of the flood, but can strongly impact subsequent peaks in the case of a multi-storm event. Because this kind of model is based on a limited

  12. Limited effects of an extreme flood event on corals at Ningaloo Reef

    Science.gov (United States)

    Lozano-Montes, Hector M.; Keesing, John K.; Grol, Monique G.; Haywood, Michael D. E.; Vanderklift, Mathew A.; Babcock, Russ C.; Bancroft, Kevin

    2017-05-01

    In late April 2014 Ningaloo Reef was exposed to significant freshwater and sediment outflow following an extreme rainfall event (>200 mm in 48 h). It produced a plume of brown water of 9.63 km2 that was present two days after the rainfall event. The extent of the plume decreased by 55.9% within ten days. Benthic surveys were conducted at eight sites at Ningaloo (three of them within the plume and five outside the plume) using 25 m line transects to assess the percentage cover of all major benthic organisms, including hard corals, soft corals, algae and turf algae. Results from a survey done in May 2014 (approximately one month after the flooding) were compared with one done in March 2014 (before the extreme rainfall event). Corals from the genus Acropora were the dominant species in the coral assemblages surveyed. Our results indicate that percentage cover of Acropora did not vary significantly between sites inside and outside of the plume, but percentage cover of non-Acropora coral varied significantly among plume and non-plume sites. Both patterns were present before the flood. The results show that the flood-induced plumes caused limited damage to the coral along this part of Ningaloo Reef.

  13. No phenotypic plasticity in nest-site selection in response to extreme flooding events.

    Science.gov (United States)

    Bailey, Liam D; Ens, Bruno J; Both, Christiaan; Heg, Dik; Oosterbeek, Kees; van de Pol, Martijn

    2017-06-19

    Phenotypic plasticity is a crucial mechanism for responding to changes in climatic means, yet we know little about its role in responding to extreme climatic events (ECEs). ECEs may lack the reliable cues necessary for phenotypic plasticity to evolve; however, this has not been empirically tested. We investigated whether behavioural plasticity in nest-site selection allows a long-lived shorebird ( Haematopus ostralegus ) to respond to flooding. We collected longitudinal nest elevation data on individuals over two decades, during which time flooding events have become increasingly frequent. We found no evidence that individuals learn from flooding experiences, showing nest elevation change consistent with random nest-site selection. There was also no evidence of phenotypic plasticity in response to potential environmental cues (lunar nodal cycle and water height). A small number of individuals, those nesting near an artificial sea wall, did show an increase in nest elevation over time; however, there is no conclusive evidence this occurred in response to ECEs. Our study population showed no behavioural plasticity in response to changing ECE patterns. More research is needed to determine whether this pattern is consistent across species and types of ECEs. If so, ECEs may pose a major challenge to the resilience of wild populations.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

  14. Identification of flood events inside karst cavities: Fria Cave (Asturias - NW Spain)

    Science.gov (United States)

    Gonzalez Lemos, Saul; Stoll, Heather

    2013-04-01

    Fluvial records may be well preserved in subterranean karst drainage networks and fluvial deposits cemented in speleothems may provide good chronology of past flood events. In several karst systems in Asturias (NW. Spain), moments of extreme precipitation events produce deposits from flood events in the bed and walls of caves which we propose are also recorded in the calcium carbonate stalagmites growing in the cave. The final stretch of the studied cave (Fria Cave), with a development of 360 m in length, intersects a small perennial stream which in our observation has maintained a minimum discharge of about 0.022 m3/s but periodically overflows into the vadose cave passage. Immediately after a flood overflow event, water marks and foam detritus are visible at various levels on the cave walls and corresponding to heights of bottlenecks in overflow drainage through the cave passage. Flood events deposit sand on terraces on the cave wall and move large volumes of sand in the cave bed. These extreme events leave a long-term record in i) wall coloration or water marks on the cave walls; and ii) detrital particles preserved as inclusions inside the stalagmites. Throughout this cave, it is possible to recognize chromatic changes in the walls, such as manganese oxide stains, which coincide with one of the water marks left during a recent flood event. The most salient manganese oxide on the walls rises up to 1.5 m measured from the thalweg and we interpreted it as the result of a frequent process of wetting - drying related to frequent flooding of the cave. Since 3-4 ka, drapery flowstone has been deposited over this oxide coating in some parts of the cave and the drapery remains free of oxide coating. We interpret this as indicating a reduction in the frequency and/or duration of flooding to this height, coincident with a regional drying trend in late Holocene. Stalagmites growing in the bed of the cave appear to trap fluvial sediments like sand or silts particles, which

  15. Combined impact of global river-floods and tropical cyclones on long-term economic growth

    Science.gov (United States)

    Geiger, Tobias; Piontek, Franziska; Frieler, Katja

    2016-04-01

    Worldwide direct economic losses associated with the impact of river-floods and tropical cyclones have seen a rapid increase over time. Their nominal impact is projected to rise even further as the exposed population grows, per capita income increases, and anthropogenic climate change manifests. Beyond the immediate damage of each event, indirect economic impacts can affect growth trajectories of countries as a whole for many years after the disaster. Whether the cumulated indirect effects stimulate or hinder economic growth in the long-run is so far undecided as previous studies find contradicting results depending on the analysed hazard and the underlying methodology. We here combine two types of the costliest meteorological disasters worldwide in order to gain certainty on their joint impact in a comprehensive way. Relative affected population by country and year is determined based on historical tropical cyclone tracks (IBTrACS) and historical simulations of river-flood return periods forced by observed weather and used as a predictor for the disaster's impact on national Gross Domestic Product (GDP) time series. Controlling for various non-disaster related effects, we find a cumulated GDP deficit that remains robust for more than a decade after the event.

  16. Predicted high-water elevations for selected flood events at the Albert Pike Recreation Area, Ouachita National Forest

    Science.gov (United States)

    D.A. Marion

    2012-01-01

    The hydraulic characteristics are determined for the June 11, 2010, flood on the Little Missouri River at the Albert Pike Recreation Area in Arkansas. These characteristics are then used to predict the high-water elevations for the 10-, 25-, 50-, and 100-year flood events in the Loop B, C, and D Campgrounds of the recreation area. The peak discharge and related...

  17. Urban pluvial flood prediction

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Nielsen, Jesper Ellerbæk; Jensen, David Getreuer

    2016-01-01

    Flooding produced by high-intensive local rainfall and drainage system capacity exceedance can have severe impacts in cities. In order to prepare cities for these types of flood events – especially in the future climate – it is valuable to be able to simulate these events numerically both...... historically and in real-time. There is a rather untested potential in real-time prediction of urban floods. In this paper radar data observations with different spatial and temporal resolution, radar nowcasts of 0–2 h lead time, and numerical weather models with lead times up to 24 h are used as inputs...... to an integrated flood and drainage systems model in order to investigate the relative difference between different inputs in predicting future floods. The system is tested on a small town Lystrup in Denmark, which has been flooded in 2012 and 2014. Results show it is possible to generate detailed flood maps...

  18. Generation of a Design Flood-Event Scenario for a Mountain River with Intense Sediment Transport

    Directory of Open Access Journals (Sweden)

    Alessio Radice

    2016-12-01

    Full Text Available International directives encourage the incorporation of sediment transport analyses into flood risk assessment, in recognition of the significant role played by sediment in flood hazard. However, examples of risk analysis frameworks incorporating the effect of sediment transport are still not widespread in the literature, resulting in a lack of clear guidelines. This manuscript considers a study site in the Italian Alps and presents a hydro-morphologic model for generation of flood scenarios towards hazard assessment. The analysis is concentrated on a design flood event with 100-year return period, for which an outflowing discharge is computed as a result of the river modeling. However, it is also argued how suitable model input parameter values can be obtained from analyses of river flows in a yearly duration curve. Modeling tools are discussed with respect to their capabilities and limitations. The results of the analysis are site-specific, but the proposed methodology can be exported to other hydro-graphic basins.

  19. The influence of non-stationarity in extreme hydrological events on flood frequency estimation

    Directory of Open Access Journals (Sweden)

    Šraj Mojca

    2016-12-01

    Full Text Available Substantial evidence shows that the frequency of hydrological extremes has been changing and is likely to continue to change in the near future. Non-stationary models for flood frequency analyses are one method of accounting for these changes in estimating design values. The objective of the present study is to compare four models in terms of goodness of fit, their uncertainties, the parameter estimation methods and the implications for estimating flood quantiles. Stationary and non-stationary models using the GEV distribution were considered, with parameters dependent on time and on annual precipitation. Furthermore, in order to study the influence of the parameter estimation approach on the results, the maximum likelihood (MLE and Bayesian Monte Carlo Markov chain (MCMC methods were compared. The methods were tested for two gauging stations in Slovenia that exhibit significantly increasing trends in annual maximum (AM discharge series. The comparison of the models suggests that the stationary model tends to underestimate flood quantiles relative to the non-stationary models in recent years. The model with annual precipitation as a covariate exhibits the best goodness-of-fit performance. For a 10% increase in annual precipitation, the 10-year flood increases by 8%. Use of the model for design purposes requires scenarios of future annual precipitation. It is argued that these may be obtained more reliably than scenarios of extreme event precipitation which makes the proposed model more practically useful than alternative models.

  20. Impact of Reservoir Operation to the Inflow Flood - a Case Study of Xinfengjiang Reservoir

    Science.gov (United States)

    Chen, L.

    2017-12-01

    Building of reservoir shall impact the runoff production and routing characteristics, and changes the flood formation. This impact, called as reservoir flood effect, could be divided into three parts, including routing effect, volume effect and peak flow effect, and must be evaluated in a whole by using hydrological model. After analyzing the reservoir flood formation, the Liuxihe Model for reservoir flood forecasting is proposed. The Xinfengjiang Reservoir is studied as a case. Results show that the routing effect makes peak flow appear 4 to 6 hours in advance, volume effect is bigger for large flood than small one, and when rainfall focus on the reservoir area, this effect also increases peak flow largely, peak flow effect makes peak flow increase 6.63% to 8.95%. Reservoir flood effect is obvious, which have significant impact to reservoir flood. If this effect is not considered in the flood forecasting model, the flood could not be forecasted accurately, particularly the peak flow. Liuxihe Model proposed for Xinfengjiang Reservoir flood forecasting has a good performance, and could be used for real-time flood forecasting of Xinfengjiang Reservoir.Key words: Reservoir flood effect, reservoir flood forecasting, physically based distributed hydrological model, Liuxihe Model, parameter optimization

  1. An overview of the applications for early warning and mapping of the flood events in New Brunswick

    DEFF Research Database (Denmark)

    Mioc, Darka; McGillivray, E.; Anton, F.

    2014-01-01

    This paper gives an overview of the on-line flood warning implementation in the province of New Brunswick, Canada. The on-line flood warning applications are available via the “River Watch” website provided by the New Brunswick Department of Environment. Advanced GIS technology combined......, quantified and displayed on digital maps allowing decision makers and the general population to comprehend and visualize the possible area and impact of the flooding. The WebGIS applications that are available from the “River Watch” web site provide snow reports and maps, flood warnings and interactive maps....... The searchable historical database containing reports about the impact of past floods and estimated damages provides a valuable insight into the past of the province of New Brunswick and the motivation for development of the system for flood prediction and management....

  2. Source and composition of surface water dissolved organic matter (DOM) and the effect of flood events on the organic matter cycling

    Science.gov (United States)

    Bondar-Kunze, Elisabeth; Welti, Nina; Tritthart, Michael; Baker, Andrew; Pinay, Gilles; Hein, Thomas

    2014-05-01

    Floodplains are often simultaneously affected by land use change, river regulation and loss of hydrological dynamics which alter the surface water connectivity between floodplain and river main channel. These alterations can have significant impacts on the sources of organic matter and their degradation and thus, the carbon cycling of riverine landscapes. Although floodplains are known to be important sources of dissolved organic matter (DOM) within watersheds, reduced hydrological connectivity impair their role. The key questions of our research were to determine i) to what extent the degree of connection between the Danube River and its floodplain controlled the DOM composition with its backwater systems, and ii) what were the effects of the DOM changes on carbon cycling in floodplains during two flood events with different magnitude? In this study we report on the variations in DOM spectrophotometric properties of surface waters in different connected floodplain areas and during two flood events of different magnitude in a section of the Alluvial Zone National Park of the Danube River downstream Vienna, Austria. Two backwater floodplain systems were studied, one backwater system mostly disconnected from the fluvial dynamics except during high flood events (Lower Lobau) and the second one, recently restored and connected even during mean flow conditions (Orth). Fluorescence excitation-emission matrix (EEM) spectrophotometry and water chemical analyses were applied to investigate the DOM dynamics. In both backwater systems 15 sites were sampled monthly for two years and every second day during a flood event.

  3. The impact of the 2011 floods in Thailand on world economy using resilience concept

    Science.gov (United States)

    Jaboyedoff, Michel; Derron, Marc-Henri; Nicolet, Pierrick; Rudaz, Benjamin; Sudmeier, Karen

    2014-05-01

    In fall 2011, Thailand suffered from floods in the area of Bangkok, where 30% of the world production of hard disks (HD) was located. This event had a great impact on HD production, which decreased drastically. In analysing the market price evolution of HDs throughout time after the event, the market price for HDs returned to a "normal" after one year. This variable can be considered as an index that recovers its normal value, similar to an indicator of resilience, when defined as « the efficiency required to return to a normal state during a given period of time ». In other words, it describes how efficiently world HD production returned to "business as usual". This presentation aims to provide a further analysis of resilience as relates to the overall cost of recovery after disasters and an element that should be included in a more comprehensive analysis of risk. To further analyse the concept of resilience, instantaneous resilience is defined: integration over time permits to obtain the total impact of this flood event on the world HD business based on the market prices. In the present approach we consider the direct cost of a disaster as the result of the standard risk (R) equation (R = H x V x Exp x W) including the vulnerability (V) which describes the direct impact of a disaster taking into account the elements at risk's value or number (W), the exposure (Exp) and the hazard (H). The total impact of a disaster (Impact total = R + DRE) is the sum of R and cost post disaster (DRE), which corresponds to the indirect costs of the disaster and depends on resilience. The resilience is then the capacity of a variable to reach a value similar to its pre-event value over a period of time. Its unit is then %. Regarding the Thai event, over one year, resilience is estimated at 69%, which leads to a negative impact of the flood of around 31% on the HD price or approximately 10 billion US globally. This result is similar to other estimations. This approach underlines

  4. Creating social impact with sport events

    OpenAIRE

    Hover, P.; Dijk, B.; Breedveld, K.; Eekeren, F.J.A. van; Slender, H.

    2016-01-01

    All over the world, sport events are seen as significant tools for creating positive social impact. This is understandable, as sport events have the power to attract enthusiastic participants, volunteers and to reach large audiences of visitors and followers via (social) media. Outbursts of excitement, pleasure and feelings of camaraderie are experienced among millions of people in the case of mega events. Still, a fairly large section of the population does not care that much for sports. Som...

  5. Creating social impact with sport events

    NARCIS (Netherlands)

    Hover, P.; Dijk, B.; Breedveld, K.; Eekeren, F.J.A. van; Slender, H.

    2016-01-01

    All over the world, sport events are seen as significant tools for creating positive social impact. This is understandable, as sport events have the power to attract enthusiastic participants, volunteers and to reach large audiences of visitors and followers via (social) media. Outbursts of

  6. Regional hydrological models for distributed flash-floods forecasting: towards an estimation of potential impacts and damages

    Science.gov (United States)

    Le Bihan, Guillaume; Payrastre, Olivier; Gaume, Eric; Pons, Frederic; Moncoulon, David

    2016-04-01

    incorporated in the model. The stage/discharge relations obtained at gauging stations were also compared to the real rating curves, showing a very different behavior of the method depending on the local configuration of the considered site. Some developments are now in progress in order to evaluate and validate, as far as possible, the results of the entire simulation chain at the event scale. This work relies on the comparison of simulation results (estimated flood impacts) with insurance losses data (provided by CCR) for several significant past flood events. The first results of this work will be presented.

  7. Evaluating the Impacts of Spatial Uncertainties in Quantitative Precipitation Estimation (QPE) Products on Flood Modelling

    Science.gov (United States)

    Gao, Z.; Wu, H.; Li, J.; Hong, Y.; Huang, J.

    2017-12-01

    Precipitation is often the major uncertainty source of hydrologic modelling, e.g., for flood simulation. The quantitative precipitation estimation (QPE) products when used as input for hydrologic modelling can cause significant difference in model performance because of the large variations in their estimation of precipitation intensity, duration, and spatial distribution. Objectively evaluating QPE and deriving the best estimation of precipitation at river basin scale, represent a bottleneck which has been faced by the hydrometeorological community, despite they are desired by many researches including flood simulation, such as the Global Flood Monitoring System using the Dominant river tracing-Routing Integrated with VIC Environment (DRIVE) model (Wu et al., 2014). Recently we developed a Multiple-product-driven hydrological Modeling Framework (MMF) for objective evaluation of QPE products using the DRIVE model (Wu et al., 2017). In this study based on the MMF, we (1) compare location, spatial characteristics, and geometric patterns of precipitation among QPE products at various temporal scales by adopting an object-oriented method; (2) demonstrate their effects on flood magnitude and timing simulation through the DRIVE model; and (3) further investigate and understand how different precipitation spatial patterns evolute and result in difference in streamflow and flood peak (magnitude and timing), through a linear routing scheme which is employed to decompose the contribution of flood peak during rain-flood events. This study shows that there can be significant difference in spatial patterns of accumulated precipitation at various temporal scales (from days to hourly) among QPE products, which cause significant difference in flood simulation particularly in peak timing prediction. Therefore, the evaluation of spatial pattern of precipitation should be considered as an important part of the framework for objective evaluation of QPE and the derivation of the best

  8. Mapping the Recent US Hurricanes Triggered Flood Events in Near Real Time

    Science.gov (United States)

    Shen, X.; Lazin, R.; Anagnostou, E. N.; Wanik, D. W.; Brakenridge, G. R.

    2017-12-01

    Synthetic Aperture Radar (SAR) observations is the only reliable remote sensing data source to map flood inundation during severe weather events. Unfortunately, since state-of-art data processing algorithms cannot meet the automation and quality standard of a near-real-time (NRT) system, quality controlled inundation mapping by SAR currently depends heavily on manual processing, which limits our capability to quickly issue flood inundation maps at global scale. Specifically, most SAR-based inundation mapping algorithms are not fully automated, while those that are automated exhibit severe over- and/or under-detection errors that limit their potential. These detection errors are primarily caused by the strong overlap among the SAR backscattering probability density functions (PDF) of different land cover types. In this study, we tested a newly developed NRT SAR-based inundation mapping system, named Radar Produced Inundation Diary (RAPID), using Sentinel-1 dual polarized SAR data over recent flood events caused by Hurricanes Harvey, Irma, and Maria (2017). The system consists of 1) self-optimized multi-threshold classification, 2) over-detection removal using land-cover information and change detection, 3) under-detection compensation, and 4) machine-learning based correction. Algorithm details are introduced in another poster, H53J-1603. Good agreements were obtained by comparing the result from RAPID with visual interpretation of SAR images and manual processing from Dartmouth Flood Observatory (DFO) (See Figure 1). Specifically, the over- and under-detections that is typically noted in automated methods is significantly reduced to negligible levels. This performance indicates that RAPID can address the automation and accuracy issues of current state-of-art algorithms and has the potential to apply operationally on a number of satellite SAR missions, such as SWOT, ALOS, Sentinel etc. RAPID data can support many applications such as rapid assessment of damage

  9. Morphological records of storm floods exemplified by the impact of the 1872 Baltic storm on a sandy spit system in south-eastern Denmark

    DEFF Research Database (Denmark)

    Clemmensen, Lars B.; Bendixen, Mette; Hede, Mikkel U.

    2014-01-01

    Beach-ridge systems are important geo-archives providing evidence for past wave climate including catastrophic storm flood events. This study investigates the morphological impacts of the 1872 Baltic storm flood on a beach-ridge system (sandy spit) in south-eastern Denmark and evaluates...... the frequency of extreme storm flood events in the area over a longer time perspective. This paper combines field studies of morphology and sedimentary deposits, studies of historical maps, digital terrain model, ground-penetrating radar profiles, and luminescence dating. Sea water reached 2.8 m above mean sea...... level (amsl) during peak inundation and, based on studies of the morphological impacts of the 1872 storm flood, the event can be divided into four phases. Phase 1: increasing mean water levels and wave activity at the beach brought sediments from the beach (intertidal bars and normal berm) higher up...

  10. Shoreline changes and Coastal Flooding impacts: South Gujarat coast (India)

    Science.gov (United States)

    Parihar, S. B.

    2016-12-01

    South Gujarat coast (India) is experiencing increased coastal inundation and erosion caused by sea-level rise affecting the population, infrastructure, and environment. The area falls under low elevation coastal zone (LEZ) and its topography of the area is also making coast highly susceptible to flooding, especially at high tides and during the rainy season. As part of studies on shoreline changes field trip carried on the coastal taluka's of South Gujarat coast i.e. Surat, Navsari and Valsad shows various temporal changes is taking place at coastal belt. There are ample of studies on coastal dynamics and impacts. The study focus on spatial temporal analysis shows the vulnerable zones covering various physical elements at risk. These coastal areas are attractive in nature for all kind of economic development and growth because of availability of the water & fertile land for house hold use, fishing and transportation. On the contrary, South Gujarat coast being tectonically active; makes this region high vulnerable for any kind of infrastructure development. The region had also witnessed loss of life and property, disruptions to transport & power and incidences of epidemics during the floods of 2006 in Surat. Coastal flooding would, under these scenarios, threaten region that are home of 370,000 approx (Census, 2011) people in seven coastal taluka's of Surat, Navsari and Valsad district. Among the people residing in the region, the most vulnerable communities are fishermen, farmer and industrial labours. The wide range of infrastructure such as roads, hospitals, schools, power plants, industries and port will also be at risk. Shoreline changes are inevitably changing the characteristics of south Gujarat coast; practices and policies should be put in place to mitigate the potentially adverse impacts on environment and human settlements. Key words: sea level rise, LEZ, vulnerable, erosion, inundation, spatial temporal analysis, landuse changes.

  11. Simulation of Flash-Flood-Producing Storm Events in Saudi Arabia Using the Weather Research and Forecasting Model

    KAUST Repository

    Deng, Liping

    2015-05-01

    The challenges of monitoring and forecasting flash-flood-producing storm events in data-sparse and arid regions are explored using the Weather Research and Forecasting (WRF) Model (version 3.5) in conjunction with a range of available satellite, in situ, and reanalysis data. Here, we focus on characterizing the initial synoptic features and examining the impact of model parameterization and resolution on the reproduction of a number of flood-producing rainfall events that occurred over the western Saudi Arabian city of Jeddah. Analysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim) data suggests that mesoscale convective systems associated with strong moisture convergence ahead of a trough were the major initial features for the occurrence of these intense rain events. The WRF Model was able to simulate the heavy rainfall, with driving convective processes well characterized by a high-resolution cloud-resolving model. The use of higher (1 km vs 5 km) resolution along the Jeddah coastline favors the simulation of local convective systems and adds value to the simulation of heavy rainfall, especially for deep-convection-related extreme values. At the 5-km resolution, corresponding to an intermediate study domain, simulation without a cumulus scheme led to the formation of deeper convective systems and enhanced rainfall around Jeddah, illustrating the need for careful model scheme selection in this transition resolution. In analysis of multiple nested WRF simulations (25, 5, and 1 km), localized volume and intensity of heavy rainfall together with the duration of rainstorms within the Jeddah catchment area were captured reasonably well, although there was evidence of some displacements of rainstorm events.

  12. An agent-based modelling framework to explore the role of social media and stubborn people on evacuation rates during flooding events

    Science.gov (United States)

    Du, E.; Cai, X.; Minsker, B. S.; Sun, Z.

    2017-12-01

    Flood warnings from various information sources are important for individuals to make evacuation decisions during a flood event. In this study, we develop a general opinion dynamics model to simulate how individuals update their flood hazard awareness when exposed to multiple information sources, including global broadcast, social media, and observations of neighbors' actions. The opinion dynamics model is coupled with a traffic model to simulate the evacuation processes of a residential community with a given transportation network. Through various scenarios, we investigate how social media affect the opinion dynamics and evacuation processes. We find that stronger social media can make evacuation processes more sensitive to the change of global broadcast and neighbor observations, and thus, impose larger uncertainty on evacuation rates (i.e., a large range of evacuation rates corresponding to sources of information). For instance, evacuation rates are lower when social media become more influential and individuals have less trust in global broadcast. Stubborn individuals can significantly affect the opinion dynamics and reduce evacuation rates. In addition, evacuation rates respond to the percentage of stubborn agents in a non-linear manner, i.e., above a threshold, the impact of stubborn agents will be intensified by stronger social media. These results highlight the role of social media in flood evacuation processes and the need to monitor social media so that misinformation can be corrected in a timely manner. The joint impacts of social media, quality of flood warnings and transportation capacity on evacuation rates are also discussed.

  13. Combining empirical approaches and error modelling to enhance predictive uncertainty estimation in extrapolation for operational flood forecasting. Tests on flood events on the Loire basin, France.

    Science.gov (United States)

    Berthet, Lionel; Marty, Renaud; Bourgin, François; Viatgé, Julie; Piotte, Olivier; Perrin, Charles

    2017-04-01

    An increasing number of operational flood forecasting centres assess the predictive uncertainty associated with their forecasts and communicate it to the end users. This information can match the end-users needs (i.e. prove to be useful for an efficient crisis management) only if it is reliable: reliability is therefore a key quality for operational flood forecasts. In 2015, the French flood forecasting national and regional services (Vigicrues network; www.vigicrues.gouv.fr) implemented a framework to compute quantitative discharge and water level forecasts and to assess the predictive uncertainty. Among the possible technical options to achieve this goal, a statistical analysis of past forecasting errors of deterministic models has been selected (QUOIQUE method, Bourgin, 2014). It is a data-based and non-parametric approach based on as few assumptions as possible about the forecasting error mathematical structure. In particular, a very simple assumption is made regarding the predictive uncertainty distributions for large events outside the range of the calibration data: the multiplicative error distribution is assumed to be constant, whatever the magnitude of the flood. Indeed, the predictive distributions may not be reliable in extrapolation. However, estimating the predictive uncertainty for these rare events is crucial when major floods are of concern. In order to improve the forecasts reliability for major floods, an attempt at combining the operational strength of the empirical statistical analysis and a simple error modelling is done. Since the heteroscedasticity of forecast errors can considerably weaken the predictive reliability for large floods, this error modelling is based on the log-sinh transformation which proved to reduce significantly the heteroscedasticity of the transformed error in a simulation context, even for flood peaks (Wang et al., 2012). Exploratory tests on some operational forecasts issued during the recent floods experienced in

  14. Characterization of a Flood Event through a Sediment Analysis: The Tescio River Case Study

    Directory of Open Access Journals (Sweden)

    Silvia Di Francesco

    2016-07-01

    Full Text Available This paper presents the hydrological analysis and grain size characteristics of fluvial sediments in a river basin and their combination to characterize a flood event. The overall objective of the research is the development of a practical methodology based on experimental surveys to reconstruct the hydraulic history of ungauged river reaches on the basis of the modifications detected on the riverbed during the dry season. The grain size analysis of fluvial deposits usually requires great technical and economical efforts and traditional sieving based on physical sampling is not appropriate to adequately represent the spatial distribution of sediments in a wide area of a riverbed with a reasonable number of samples. The use of photographic sampling techniques, on the other hand, allows for the quick and effective determination of the grain size distribution, through the use of a digital camera and specific graphical algorithms in large river stretches. A photographic sampling is employed to characterize the riverbed in a 3 km ungauged reach of the Tescio River, a tributary of the Chiascio River, located in central Italy, representative of many rivers in the same geographical area. To this end, the particle size distribution is reconstructed through the analysis of digital pictures of the sediments taken on the riverbed in dry conditions. The sampling has been performed after a flood event of known duration, which allows for the identification of the removal of the armor in one section along the river reach under investigation. The volume and composition of the eroded sediments made it possible to calculate the average flow rate associated with the flood event which caused the erosion, by means of the sediment transport laws and the hydrological analysis of the river basin. A hydraulic analysis of the river stretch under investigation was employed to verify the validity of the proposed procedure.

  15. Extreme seasonal droughts and floods in Amazonia: causes, trends and impacts

    Science.gov (United States)

    Marengo, J. A.

    2015-12-01

    J. A. Marengo * and J. C. Espinoza** * Centro Nacional de Monitoramento e Alerta de Desastres Naturais, Ministério da Ciência, Tecnologia e Inovação, Sao Paulo, Brazil ** Subdirección de Ciencias de la Atmósfera e Hidrósfera (SCAH), Instituto Geofísico del Perú, Lima, Peru This paper reviews recent progress in the study and understanding of extreme seasonal events in the Amazon region, focusing on drought and floods. The review includes a history of droughts and floods in the past, in the present and some discussions on future extremes in the context of climate change and its impacts on the Amazon region. Several extreme hydrological events, some of them characterized as 'once in a century', have been reported in the Amazon region during the last decade. While abundant rainfall in various sectors of the basin has determined extreme floods along the river's main stem in 1953, 1989, 1999, 2009, 2012-2015, deficient rainfall in 1912, 1926, 1963, 1980, 1983, 1995, 1997, 1998, 2005 and 2010 has caused anomalously low river levels, and an increase in the risk and number of fires in the region, with consequences for humans. This is consistent with changes in the variability of the hydrometeorology of the basin and suggests that extreme hydrological events have been more frequent in the last two decades. Some of these intense/reduced rainfalls and subsequent floods/droughts were associated (but not exclusively) with La Niña/El Niño events. In addition, moisture transport anomalies from the tropical Atlantic into Amazonia, and from northern to southern Amazonia alter the water cycle in the region year-to-year. We also assess the impacts of such extremes on natural and human systems in the region, considering ecological, economic and societal impacts in urban and rural areas, particularly during the recent decades. In the context of the future climate change, studies show a large range of uncertainty, but suggest that drought might intensify through the 21st

  16. Extreme flood event reconstruction spanning the last century in the El Bibane Lagoon (southeastern Tunisia): a multi-proxy approach

    Science.gov (United States)

    Affouri, Aida; Dezileau, Laurent; Kallel, Nejib

    2017-06-01

    Climate models project that rising atmospheric carbon dioxide concentrations will increase the frequency and the severity of some extreme weather events. The flood events represent a major risk for populations and infrastructures settled on coastal lowlands. Recent studies of lagoon sediments have enhanced our knowledge on extreme hydrological events such as palaeo-storms and on their relation with climate change over the last millennium. However, few studies have been undertaken to reconstruct past flood events from lagoon sediments. Here, the past flood activity was investigated using a multi-proxy approach combining sedimentological and geochemical analysis of surfaces sediments from a southeastern Tunisian catchment in order to trace the origin of sediment deposits in the El Bibane Lagoon. Three sediment sources were identified: marine, fluvial and aeolian. When applying this multi-proxy approach on core BL12-10, recovered from the El Bibane Lagoon, we can see that finer material, a high content of the clay and silt, and a high content of the elemental ratios (Fe / Ca and Ti / Ca) characterise the sedimentological signature of the palaeo-flood levels identified in the lagoonal sequence. For the last century, which is the period covered by the BL12-10 short core, three palaeo-flood events were identified. The age of these flood events have been determined by 210Pb and 137Cs chronology and give ages of AD 1995 ± 6, 1970 ± 9 and 1945 ± 9. These results show a good temporal correlation with historical flood events recorded in southern Tunisia in the last century (AD 1932, 1969, 1979 and 1995). Our finding suggests that reconstruction of the history of the hydrological extreme events during the upper Holocene is possible in this location through the use of the sedimentary archives.

  17. Extreme flood event reconstruction spanning the last century in the El Bibane Lagoon (southeastern Tunisia: a multi-proxy approach

    Directory of Open Access Journals (Sweden)

    A. Affouri

    2017-06-01

    Full Text Available Climate models project that rising atmospheric carbon dioxide concentrations will increase the frequency and the severity of some extreme weather events. The flood events represent a major risk for populations and infrastructures settled on coastal lowlands. Recent studies of lagoon sediments have enhanced our knowledge on extreme hydrological events such as palaeo-storms and on their relation with climate change over the last millennium. However, few studies have been undertaken to reconstruct past flood events from lagoon sediments. Here, the past flood activity was investigated using a multi-proxy approach combining sedimentological and geochemical analysis of surfaces sediments from a southeastern Tunisian catchment in order to trace the origin of sediment deposits in the El Bibane Lagoon. Three sediment sources were identified: marine, fluvial and aeolian. When applying this multi-proxy approach on core BL12-10, recovered from the El Bibane Lagoon, we can see that finer material, a high content of the clay and silt, and a high content of the elemental ratios (Fe ∕ Ca and Ti ∕ Ca characterise the sedimentological signature of the palaeo-flood levels identified in the lagoonal sequence. For the last century, which is the period covered by the BL12-10 short core, three palaeo-flood events were identified. The age of these flood events have been determined by 210Pb and 137Cs chronology and give ages of AD 1995 ± 6, 1970 ± 9 and 1945 ± 9. These results show a good temporal correlation with historical flood events recorded in southern Tunisia in the last century (AD 1932, 1969, 1979 and 1995. Our finding suggests that reconstruction of the history of the hydrological extreme events during the upper Holocene is possible in this location through the use of the sedimentary archives.

  18. Quantifying suspended sediment sources during flood events in headwater catchments using diffuse reflectance spectroscopy

    Science.gov (United States)

    Legout, Cédric; Poulenard, Jérôme; Nemery, Julien; Navratil, Oldrich; Grangeon, Thomas; Evrard, Olivier; Esteves, Michel

    2013-04-01

    Increasing the understanding of the hydro-sedimentary dynamics at the catchment scale requires data on the origin of suspended sediments in addition to the classical measurements of suspended sediment concentrations and discharge. In mountainous environments the extremely high spatial and temporal variability of suspended sediment fluxes suggests that the proportions of suspended sediment sources transiting at outlets may also exhibit strong variations during flood events. However, conventional fingerprinting techniques based on geochemical and radionuclide measurements are time-consuming and rather expensive. They constitute a major limitation to conduct routine characterisation of the source of suspended sediment transiting at outlets that would require the analysis of a large number of samples. We investigated how visible or infrared diffuse reflectance spectroscopy coupled with partial least squares chemometrics techniques could be used to predict the proportion of source material in suspended sediment samples and how it could help understanding the hydro-sedimentary processes occurring during floods. The studied catchment is located in the southern French Alps, draining an area of 22-km². It is composed of black marls, limestones, molasses, undifferentiated deposits and gypsum. Forty-eight source material samples were collected in badlands areas and 328 suspended sediment samples were collected at the outlet during 23 flood events. Spectroscopic measurements were carried out on dried samples. Given that the erosion processes are particle size selective, five size fractions of source material were measured in order to assess the potential alteration of the signatures. As the biogeochemical processes occurring in the river such as iron oxidation could also affect the signatures, source materials that were immersed in the river for durations ranging from 1 day to 9 weeks were analysed. Finally, partial least-squares regression models were constructed on 81

  19. Some learnings from post-event field investigations after the june 2013 floods in the Pyrenees region in France.

    Science.gov (United States)

    Payrastre, Olivier; Bonnifait, Laurent; Gaume, Eric; Le Boursicaut, Raphael

    2014-05-01

    In June 2013 catastrophic floods occurred in south of France in the Pyrenees mountainous area. These floods were due to the combination of a high initial discharge due to snowmelt with a significant rainfall event (up to 200mm rainfall), which effects may have been enhanced by an increase of snowmelt. Although the dynamics of this flood are not really similar, some of its features clearly remind what may be observed in the case of flash floods: significant contribution of relatively small watersheds, high solid transport, very limited information on the reality of flood magnitudes due to the small size of catchments contributing to the flood and the destruction of a significant part of the gauging network. This contribution presents the results of a post event field survey conducted in July 2013 in order to document this flood in terms of intensities of hydrologic reactions. The methods used are those described in Gaume et al. [2008, 2009], with a specific focus on the exploitation of videos from weatnesses. The dataset builded includes 31 peak discharge estimates, illustrating the relatively limited intensity of hydrologic reactions if compared to flash floods, but also providing some interesting complements for the consolidation of the methodology used for post-event field investigations: - several opportunities of comparison of the peak discharge estimates obtained from post event field investigations and from the gauging network, showing an overall good coherence - possibility of very significant flow velocities (up to 6 m/s-2) in the specific context observed here (slopes reaching up to 5%). - possibility to get information on flow surface velocities fields from videos provided by weatnesses. - significant influence of space-time rainfall distribution on the features of the flood, stressing the importance of a detailed information on the contribution of the sub-catchments. Gaume E., Borga M., 2008. Post flood field investigations after major flash floods

  20. Urban Surface Water Quality, Flood Water Quality and Human Health Impacts in Chinese Cities. What Do We Know?

    Directory of Open Access Journals (Sweden)

    Yuhan Rui

    2018-02-01

    Full Text Available Climate change and urbanization have led to an increase in the frequency of extreme water related events such as flooding, which has negative impacts on the environment, economy and human health. With respect to the latter, our understanding of the interrelationship between flooding, urban surface water and human health is still very limited. More in-depth research in this area is needed to further strengthen the process of planning and implementation of responses to mitigate the negative health impacts of flooding in urban areas. The objective of this paper is to assess the state of the research on the interrelationship between surface water quality, flood water quality and human health in urban areas based on the published literature. These insights will be instrumental in identifying and prioritizing future research needs in this area. In this study, research publications in the domain of urban flooding, surface water quality and human health were collated using keyword searches. A detailed assessment of these publications substantiated the limited number of publications focusing on the link between flooding and human health. There was also an uneven geographical distribution of the study areas, as most of the studies focused on developed countries. A few studies have focused on developing countries, although the severity of water quality issues is higher in these countries. The study also revealed a disparity of research in this field across regions in China as most of the studies focused on the populous south-eastern region of China. The lack of studies in some regions has been attributed to the absence of flood water quality monitoring systems which allow the collection of real-time water quality monitoring data during flooding in urban areas. The widespread implementation of cost effective real-time water quality monitoring systems which are based on the latest remote or mobile phone based data acquisition techniques is recommended

  1. Dynamics of pollutant indicators during flood events in a small river under strong anthropogenic pressures

    Science.gov (United States)

    Brion, Natacha; Carbonnel, Vincent; Elskens, Marc; Claeys, Philippe; Verbanck, Michel A.

    2017-04-01

    In densely populated regions, human activities profoundly modify natural water circulation as well as water quality, with increased hydrological risks (floods, droughts,…) and chemical hazards (untreated sewage releases, industrial pollution,…) as consequence. In order to assess water and pollutants dynamics and their mass-balance in strongly modified river system, it is important to take into account high flow events as a significant fraction of water and pollutants loads may occur during these short events which are generally underrepresented in classical mass balance studies. A good example of strongly modified river systems is the Zenne river in and around the city of Brussels (Belgium).The Zenne River (Belgium) is a rather small but dynamic rain fed river (about 10 m3/s in average) that is under the influence of strong contrasting anthropogenic pressures along its stretch. While the upstream part of its basin is rather characterized by agricultural land-use, urban and industrial areas dominate the downstream part. In particular, the city of Brussels (1.1M inhabitants) discharges in the Zenne River amounts of wastewater that are large compared to the natural riverine flow. In order to assess water and pollutants dynamics and their mass-balance in the Zenne hydrographic network, we followed water flows and concentrations of several water quality tracers during several flood episodes with an hourly frequency and at different locations along the stretch of the River. These parameters were chosen as indicators of a whole range of pollutions and anthropogenic activities. Knowledge of the high-frequency pollutants dynamics during floods is required for establishing accurate mass-balances of these elements. We thus report here the dynamics of selected parameters during entire flood events, from the baseline to the decreasing phase and at hourly frequency. Dynamics at contrasting locations, in agricultural or urban environments are compared. In particular, the

  2. Hydrological Simulation of Flood Events At Large Basins Using Distributed Modelling

    Science.gov (United States)

    Vélez, J.; Vélez, I.; Puricelli, M.; Francés, F.

    Recent advances in technology allows to the scientist community advance in new pro- cedures in order to reduce the risk associated to flood events. A conceptual distributed model has been implemented to simulate the hydrological processes involved during floods. The model has been named TETIS. The basin is divided into rectangular cells, all of them connected according to the network drainage. The rainfall-runoff process is modelled using four linked tanks at each cell with different outflow relationships at each tank, which represent the ET, direct runoff, interflow and base flow, respectively. The routing along the channel network has been proposed using basin geomorpho- logic characteristics coupled to the cinematic wave procedure. The vertical movement along the cell is proposed using simple relationships based on soil properties as field capacity and the saturated hydraulic conductivities, which were previously obtained using land use, litology, edaphology and basin properties maps. The different vertical proccesses along the cell included are: capillar storage, infiltration, percolation and underground losses. Finally, snowmelting and reservoir routing has been included. TETIS has been implemented in the flood warning system of the Tagus River, with a basin of 59 200 km2. The time discretization of the input data is 15 minutes, and the cell size is 500x500 m. The basic parameter maps were estimated for the entire basin, and a calibration and validation processes were performed using some recorded events in the upper part of the basin. Calibration confirmed the initial parameter estimation. Additionally, the validation in time and space showed the robustness of these types of models

  3. Adapting Reservoir Operations to Reduce the Multi-Sectoral Impacts of Flood Intensification in the Lower Susquehanna

    Science.gov (United States)

    Zatarain-Salazar, J.; Reed, P. M.; Quinn, J.

    2017-12-01

    This study characterizes how changes in reservoir operations can be used to better balance growing flood intensities and the conflicting multi-sectorial demands in the Lower Susequehanna River Basin (LSRB), USA. Tensions in the LSRB are increasing with urban population pressures, evolving energy demands, and growing flood-based infrastructure vulnerabilities. This study explores how re-operation of the Conowingo Reservoir, located in the LSRB, can improve the balance between competing demands for hydropower production, urban water supply to Chester, PA and Baltimore, MD, cooling water supply for the Peach Bottom Atomic Power Plant, recreation, federal environmental flow requirements and improved mitigation of growing flood hazards. The LSRB is also one of the most flood prone basins in the US, impacted by hurricanes and rain-on-snow induced flood events causing on average $100 million in economic losses and infrastructure damages to downstream settlements every year. The purpose of this study is to evaluate the consequences of mathematical formulation choices, uncertainty characterization and the value of information when defining the Conowingo reservoir's multi-purpose operations. This work seeks to strike a balance between the complexity and the efficacy of rival framings for the problem formulations used to discover effective operating policies. More broadly, the problem of intensifying urban floods in reservoir systems with complex multi-sectoral demands is broadly relevant to developed river basins globally.

  4. Climatological aspects of cyclonic tracks associated with flood events in Crete, Greece

    Science.gov (United States)

    Flocas, H. A.; Tsanis, I. K.; Katavoutas, G.; Kouroutzoglou, J.; Iordanidou, V.; Alexakis, D. D.

    2017-11-01

    In this study, an attempt was made to identify the tracks of the synoptic-scale cyclones associated with flood events in Crete, a Greek island in the southern Aegean Sea and to investigate their kinematic and dynamic characteristics and vertical structure for a period of 25 years. Furthermore, a comparison is made with the corresponding characteristics of the population of surface cyclones passing over Crete during the same period. The Melbourne University Cyclone Tracking Algorithm was employed to examine the genesis and movement of these cyclones while their vertical profile was examined with the aid of the vertical tracing software, Vertical Tracking Scheme (VTS). The input data are based on ERA INTERIM reanalysis datasets with resolution 0.5° × 0.5° during the period 1990 to 2014. It was found that the vast majority originate mainly over the north African coasts, contrasting the preference of all cyclones passing over Crete to develop within the Southeast Mediterranean. Cyclones associated with the flood events are more intense than the cyclonic population, being mainly characterized by long duration and track length. Furthermore, they reveal characteristics of vertically organized baroclinic systems, suggesting that they are mainly driven by baroclinic processes at upper and lower levels.

  5. Simulation of rainfall-runoff for major flash flood events in Karachi

    Science.gov (United States)

    Zafar, Sumaira

    2016-07-01

    Metropolitan city Karachi has strategic importance for Pakistan. With the each passing decade the city is facing urban sprawl and rapid population growth. These rapid changes directly affecting the natural resources of city including its drainage pattern. Karachi has three major cities Malir River with the catchment area of 2252 sqkm and Lyari River has catchment area about 470.4 sqkm. These are non-perennial rivers and active only during storms. Change of natural surfaces into hard pavement causing an increase in rainfall-runoff response. Curve Number is increased which is now causing flash floods in the urban locality of Karachi. There is only one gauge installed on the upstream of the river but there no record for the discharge. Only one gauge located at the upstream is not sufficient for discharge measurements. To simulate the maximum discharge of Malir River rainfall (1985 to 2014) data were collected from Pakistan meteorological department. Major rainfall events use to simulate the rainfall runoff. Maximum rainfall-runoff response was recorded in during 1994, 2007 and 2013. This runoff causes damages and inundation in floodplain areas of Karachi. These flash flooding events not only damage the property but also cause losses of lives

  6. Impact of Radio Kogi's flood disaster awareness campaign on ...

    African Journals Online (AJOL)

    A major natural disaster that occurred in Nigeria in 2012 was the flooding of many places, including Ibaji Local Government Area of Kogi State. The flood ravaged the area, destroying food and property; and rendering the people homeless. Before, during and after the flood, Radio Kogi Lokoja had carried awareness and ...

  7. Manage Short-term Flood Events and Long-term Water Needs via Reservoir Operation: A Risk Analysis Study

    Science.gov (United States)

    Cheng, W.; Hsu, N.; Wei, C.; Cheng, W.

    2010-12-01

    This study proposes a methodology to assess the risk of the water shortage during a drought period and the risk of the downstream over-levee flows during a flood period based on the reservoir operation rules for flood control. These rules are defined by upper limits (or flood control storage zone).Through a Monte Carlo simulation, a series of hydrographs are generated to represent the reservoir inflow during a flood period based on historic typhoon events. This series of generated hydrographs are then applied to a reservoir flood operation simulation model. The simulation model calculates the water levels of reservoir at the end of a flood period and the reservoir release during the typhoon the events. Reservoir release is used to calculate the water level at downstream control locations for evaluation of a short-term over-levee risk. The ending water level of the reservoir is used as the initial condition for a water distribution optimization model that evaluates drought conditions for long-term water supply. By applying risk analysis, an assessment is made on the risk of both the water shortage during a drought and over-levee flows during flooding seasons. Based on the results of the risk analysis, we evaluate the relationship among upper-limit sets, shortage risk, and over-levee risk and also provide reservoir operation suggestions based on the risk evaluation.

  8. Estimating the impacts of urban growth on future flood risk: A comparative study

    NARCIS (Netherlands)

    Verbeek, W.

    2017-01-01

    The unprecedented growth of cities has a significant impact on future flood risk that might exceed the impacts of climate change in many metropolitan areas across the world. Although the effects of urbanisation on flood risk are well understood, assessments that include spatially explicit future

  9. Estimating the impacts of urban growth on future flood risk : A comparative study

    NARCIS (Netherlands)

    Veerbeek, W.

    2017-01-01

    The unprecedented growth of cities has a significant impact on future flood risk that might exceed the impacts of climate change in many metropolitan areas across the world. Although the effects of urbanisation on flood risk are well understood, assessments that include spatially explicit future

  10. Project house water: a novel interdisciplinary framework to assess the environmental and socioeconomic consequences of flood-related impacts.

    Science.gov (United States)

    Crawford, Sarah E; Cofalla, Catrina Brüll Nee; Aumeier, Benedikt; Brinkmann, Markus; Classen, Elisa; Esser, Verena; Ganal, Caroline; Kaip, Elena; Häussling, Roger; Lehmkuhl, Frank; Letmathe, Peter; Müller, Anne-Katrin; Rabinovitch, Ilja; Reicherter, Klaus; Schwarzbauer, Jan; Schmitt, Marco; Stauch, Georg; Wessling, Matthias; Yüce, Süleyman; Hecker, Markus; Kidd, Karen A; Altenburger, Rolf; Brack, Werner; Schüttrumpf, Holger; Hollert, Henner

    2017-01-01

    Protecting our water resources in terms of quality and quantity is considered one of the big challenges of the twenty-first century, which requires global and multidisciplinary solutions. A specific threat to water resources, in particular, is the increased occurrence and frequency of flood events due to climate change which has significant environmental and socioeconomic impacts. In addition to climate change, flooding (or subsequent erosion and run-off) may be exacerbated by, or result from, land use activities, obstruction of waterways, or urbanization of floodplains, as well as mining and other anthropogenic activities that alter natural flow regimes. Climate change and other anthropogenic induced flood events threaten the quantity of water as well as the quality of ecosystems and associated aquatic life. The quality of water can be significantly reduced through the unintentional distribution of pollutants, damage of infrastructure, and distribution of sediments and suspended materials during flood events. To understand and predict how flood events and associated distribution of pollutants may impact ecosystem and human health, as well as infrastructure, large-scale interdisciplinary collaborative efforts are required, which involve ecotoxicologists, hydrologists, chemists, geoscientists, water engineers, and socioeconomists. The research network "project house water" consists of a number of experts from a wide range of disciplines and was established to improve our current understanding of flood events and associated societal and environmental impacts. The concept of project house and similar seed fund and boost fund projects was established by the RWTH Aachen University within the framework of the German excellence initiative with support of the German research foundation (DFG) to promote and fund interdisciplinary research projects and provide a platform for scientists to collaborate on innovative, challenging research. Project house water consists of six

  11. Historical flood data series of Eastern Spanish Coast (14th-20th centuries). Improving identification of climatic patterns and human factors of flood events from primary documentary sources

    Science.gov (United States)

    Alberola, Armando; Barriendos, Mariano; Gil-Guirado, Salvador; Pérez-Morales, Alfredo; Balasch, Carles; Castelltort, Xavier; Mazón, Jordi; Pino, David; Lluís Ruiz-Bellet, Josep; Tuset, Jordi

    2016-04-01

    Historical flood data series of Eastern Spanish Coast (14th-20th centuries). Improving identification of climatic patterns and human factors of flood events from primary documentary sources Armando Alberola, Barriendos, M., Gil-Guirado, S., Pérez Morales, A., Balasch, C., Castelltort, X., Mazón, J., Pino, D., Ruiz-Bellet, J.L., Tuset, J. Historical flood events in eastern spanish coast have been studied by different research groups and projects. Complexity of flood processes, involving atmospheric, surface and human factors, is not easily understandable when long time series are required. Present analysis from PREDIFLOOD Project Consortium defines a new step of flood event databases: Improved access to primary (documentary) and secondary (bibliographical) sources, data collection for all possible locations where floods are detected, and improved system of classification (Barriendos et al., 2014). A first analysis is applied to 8 selected flood series. Long chronologies from PREDIFLOOD Project for Catalonia region (Girona, Barcelona, Tarragona, Lleida, Tortosa). In addition, to cover all sector of spanish mediterranean coast, we introduce Valencia city in Turia River basin. South Eastern sector is cover with Murcia and Caravaca cities, Segura River basin. Extension of area under study required contributions of research teams experienced in work of documentary primary sources (Alberola, 2006; Gil-Guirado, 2013). Flood frequency analysis for long scale periods show natural climatic oscillations into so-called Little Ice Age. There are general patterns, affecting most of basins, but also some local anomalies or singularities. To explain these differences and analogies it is not enough to use purely climatic factors. In this way, we analyze human factors that have been able to influence the variability of floods along last 6 centuries (demography, hydraulic infrastructures, urban development...). This approach improves strongly understanding of mechanisms producing

  12. Water-Borne Diseases and Extreme Weather Events in Cambodia: Review of Impacts and Implications of Climate Change

    Directory of Open Access Journals (Sweden)

    Grace I. Davies

    2014-12-01

    Full Text Available Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extremely low adaptive capacity of the population, this is a crucial knowledge gap. A literature review of the health impacts of floods, droughts and typhoons in Cambodia was conducted, with regional and global information reviewed where Cambodia-specific literature was lacking. Water-borne diseases are of particular concern in Cambodia, in the face of extreme weather events and climate change, due to, inter alia, a high pre-existing burden of diseases such as diarrhoeal illness and a lack of improved sanitation infrastructure in rural areas. A time-series analysis under quasi-Poisson distribution was used to evaluate the association between floods and diarrhoeal disease incidence in Cambodian children between 2001 and 2012 in 16 Cambodian provinces. Floods were significantly associated with increased diarrhoeal disease in two provinces, while the analysis conducted suggested a possible protective effect from toilets and piped water. Addressing the specific, local pre-existing vulnerabilities is vital to promoting population health resilience and strengthening adaptive capacity to extreme weather events and climate change in Cambodia.

  13. Water-Borne Diseases and Extreme Weather Events in Cambodia: Review of Impacts and Implications of Climate Change

    Science.gov (United States)

    Davies, Grace I.; McIver, Lachlan; Kim, Yoonhee; Hashizume, Masahiro; Iddings, Steven; Chan, Vibol

    2014-01-01

    Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extremely low adaptive capacity of the population, this is a crucial knowledge gap. A literature review of the health impacts of floods, droughts and typhoons in Cambodia was conducted, with regional and global information reviewed where Cambodia-specific literature was lacking. Water-borne diseases are of particular concern in Cambodia, in the face of extreme weather events and climate change, due to, inter alia, a high pre-existing burden of diseases such as diarrhoeal illness and a lack of improved sanitation infrastructure in rural areas. A time-series analysis under quasi-Poisson distribution was used to evaluate the association between floods and diarrhoeal disease incidence in Cambodian children between 2001 and 2012 in 16 Cambodian provinces. Floods were significantly associated with increased diarrhoeal disease in two provinces, while the analysis conducted suggested a possible protective effect from toilets and piped water. Addressing the specific, local pre-existing vulnerabilities is vital to promoting population health resilience and strengthening adaptive capacity to extreme weather events and climate change in Cambodia. PMID:25546280

  14. Water-borne diseases and extreme weather events in Cambodia: review of impacts and implications of climate change.

    Science.gov (United States)

    Davies, Grace I; McIver, Lachlan; Kim, Yoonhee; Hashizume, Masahiro; Iddings, Steven; Chan, Vibol

    2014-12-23

    Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extremely low adaptive capacity of the population, this is a crucial knowledge gap. A literature review of the health impacts of floods, droughts and typhoons in Cambodia was conducted, with regional and global information reviewed where Cambodia-specific literature was lacking. Water-borne diseases are of particular concern in Cambodia, in the face of extreme weather events and climate change, due to, inter alia, a high pre-existing burden of diseases such as diarrhoeal illness and a lack of improved sanitation infrastructure in rural areas. A time-series analysis under quasi-Poisson distribution was used to evaluate the association between floods and diarrhoeal disease incidence in Cambodian children between 2001 and 2012 in 16 Cambodian provinces. Floods were significantly associated with increased diarrhoeal disease in two provinces, while the analysis conducted suggested a possible protective effect from toilets and piped water. Addressing the specific, local pre-existing vulnerabilities is vital to promoting population health resilience and strengthening adaptive capacity to extreme weather events and climate change in Cambodia.

  15. Point pattern analysis applied to flood and landslide damage events in Switzerland (1972-2009)

    Science.gov (United States)

    Barbería, Laura; Schulte, Lothar; Carvalho, Filipe; Peña, Juan Carlos

    2017-04-01

    Damage caused by meteorological and hydrological extreme events depends on many factors, not only on hazard, but also on exposure and vulnerability. In order to reach a better understanding of the relation of these complex factors, their spatial pattern and underlying processes, the spatial dependency between values of damage recorded at sites of different distances can be investigated by point pattern analysis. For the Swiss flood and landslide damage database (1972-2009) first steps of point pattern analysis have been carried out. The most severe events have been selected (severe, very severe and catastrophic, according to GEES classification, a total number of 784 damage points) and Ripley's K-test and L-test have been performed, amongst others. For this purpose, R's library spatstat has been used. The results confirm that the damage points present a statistically significant clustered pattern, which could be connected to prevalence of damages near watercourses and also to rainfall distribution of each event, together with other factors. On the other hand, bivariate analysis shows there is no segregated pattern depending on process type: flood/debris flow vs landslide. This close relation points to a coupling between slope and fluvial processes, connectivity between small-size and middle-size catchments and the influence of spatial distribution of precipitation, temperature (snow melt and snow line) and other predisposing factors such as soil moisture, land-cover and environmental conditions. Therefore, further studies will investigate the relationship between the spatial pattern and one or more covariates, such as elevation, distance from watercourse or land use. The final goal will be to perform a regression model to the data, so that the adjusted model predicts the intensity of the point process as a function of the above mentioned covariates.

  16. NOAA Digital Coast Sea Level Rise and Coastal Flooding Impacts Viewer

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Level Rise and Coastal Flooding Impacts Viewer depicts potential sea level rise and its associated impacts on the nation's coastal areas. These coastal areas...

  17. Assessing the effects of urbanization on annual runoff and flood events using an integrated hydrological modeling system for Qinhuai River basin, China

    Science.gov (United States)

    Du, Jinkang; Qian, Li; Rui, Hanyi; Zuo, Tianhui; Zheng, Dapeng; Xu, Youpeng; Xu, C.-Y.

    2012-09-01

    SummaryThis study developed and used an integrated modeling system, coupling a distributed hydrologic and a dynamic land-use change model, to examine effects of urbanization on annual runoff and flood events of the Qinhuai River watershed in Jiangsu Province, China. The Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS) was used to calculate runoff generation and the integrated Markov Chain and Cellular Automata model (CA-Markov model) was used to develop future land use maps. The model was calibrated and validated using observed daily streamflow data collected at the two outlets of watershed. Landsat Thematic Mapper (TM) images from 1988, 1994, 2006, Enhanced Thematic Mapper Plus (ETM+) images from 2001, 2003 and a China-Brazil Earth Resources Satellite (CBERS) image from 2009 were used to obtain historical land use maps. These imageries revealed that the watershed experienced conversion of approximately 17% non-urban area to urban area between 1988 and 2009. The urbanization scenarios for various years were developed by overlaying impervious surfaces of different land use maps to 1988 (as a reference year) map sequentially. The simulation results of HEC-HMS model for the various urbanization scenarios indicate that annual runoff, daily peak flow, and flood volume have increased to different degrees due to urban expansion during the study period (1988-2009), and will continue to increase as urban areas increase in the future. When impervious ratios change from 3% (1988) to 31% (2018), the mean annual runoff would increase slightly and the annual runoff in the dry year would increase more than that in the wet year. The daily peak discharge of eight selected floods would increase from 2.3% to 13.9%. The change trend of flood volumes is similar with that of peak discharge, but with larger percentage changes than that of daily peak flows in all scenarios. Sensitivity analysis revealed that the potential changes in peak discharge and flood volume with

  18. Quantifying the Impact of Floods on Bacillary Dysentery in Dalian City, China, From 2004 to 2010.

    Science.gov (United States)

    Xu, Xin; Ding, Guoyong; Zhang, Ying; Liu, Zhidong; Liu, Qiyong; Jiang, Baofa

    2017-04-01

    Studies quantifying relationships between floods and diarrheal diseases have mainly been conducted in low-latitude regions. It's therefore increasingly important to examine these relationships in midlatitude regions, where they may have significant public health implications. This study aimed to examine the association between floods and bacillary dysentery in the city of Dalian, China. A generalized additive mixed model was applied to examine the association between floods and bacillary dysentery. The relative risk (RR) of flood impact on bacillary dysentery was estimated. A total of 18,976 cases of bacillary dysentery were reported in Dalian during the study period. Two weeks' lagged effect was detected from the impact of floods on bacillary dysentery. The RR of flood impact on bacillary dysentery was 1.17 (95% CI: 1.03-1.33). Floods have significantly increased the risk of bacillary dysentery in Dalian. More studies should focus on the association between floods and infectious diseases in different regions. Our findings have significant implications for managing the negative health impact of floods in the midlatitude region of China. (Disaster Med Public Health Preparedness. 2017;11:190-195).

  19. Sea Level Rise Impacts on Precipitation-Induced Flooding

    Science.gov (United States)

    Buzzanga, B. A.

    2016-12-01

    Global sea level rise (SLR) is one of the most immediate impacts of climate change, and poses a significant threat to low-lying coastal communities worldwide. The metropolitan region of Hampton Roads in Southeastern Virginia is one such community, and one where knowledge surrounding SLR is rapidly accumulating. However, most of the research is focused exclusively on surface water processes despite the presence of a shallow groundwater table closely connected to them. SLR will continue to cause the groundwater table to increase in tidally influenced areas of Hampton Road, and thereby decrease storage capacity of the unsaturated zone (UZ). This study investigates how reduced unsaturated storage changes the rainfall-runoff relationship and the resulting areal-flood hazard spectrum. We choose a tidal watershed in Hampton Roads to conduct a conceptual yet realistic simulation of the hydrologic cycle using ten years of historical precipitation data with SLR scenarios from 0 m (current) to 2 m in 0.3048 m intervals. Groundwater infiltration from the land surface, recharge, and evapotranspiration are simulated using the Unsaturated-Zone Flow package with MODFLOW-NWT.Groundwater rise is simulated by increasing the stage of the tidal stream that drains the watershed. Precipitation and overland runoff are simulated using the surface water model SWMM. The two models are coupled to permit the exchange of boundary condition values at each time step. An ensemble approach is taken to test model sensitivity to parameters configurations and determine the contribution of SLR to runoff generation. The primary result of this study quantifies the relationship between SLR and runoff which enables decision makers to more effectively plan for, minimize risk of, and adapt to flooding hazards. This investigation also assesses how water content in the UZ changes in response to precipitation for different SLR scenarios. This result has widespread importance, such as decisions in crop choice or

  20. A Multi-Hydro simulation for evaluation of the impacts of flood management at Heywood, RU.

    Science.gov (United States)

    Giangola-Murzyn, Agathe; Richard, Julien; Hennermann, Karl; Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2013-04-01

    The flooding problems in urban and peri-urban areas have more and more important impacts on city life. Indeed, with the expansion of the latter, the floodplains are more intensively used and floods will generate significant damage very expensive. In the aim to reduce these costs and facilitate a return to normal faster after the flood, the FP7 SMARTeST project aims to provide users of these areas a guide to help them choose the most appropriate protection measures. It is in this context that the Multi-Hydro model has been developed and improved in the Ecole des Ponts ParisTech. This model consists into a coupling between four modules (relying on existing open source and widely validated physically based model): one for the rainfall scenario generation, one for the surface processes, one for the subsurface processes and one for the load of the sewer system. This structure of coupling allows to represent all the parts of the water's path from the surface to the sewer system's pipes and to the soil of the considered catchment and it allows to disconnect one element of the coupling system if it's necessary. Moreover, this model uses some GIS data as the elevation, the land use, the soil description and the sewer system description which can be managed by a dedicated open source SIG allowing to use directly the data in the model. The Multi-Hydro model has been used on a street of Heywood, Rochdale, Greater Manchester urban area. This residential street has known some important events during this last 10 years. Thus, Multi-Hydro has been used to evaluate the effects of the implementation of protection measures supposed to reduce the damages of the flood: a storage basin, located between Wilton Grove and the Egerton street and two barriers across the streets. For a given event, NIMROD radar data have been used to reproduce the flood. Then, the protective measures were put in place virtually. Analysis of water height maps obtained with Multi-Hydro allowed better understand

  1. The response and recovery of the dissolved organic carbon cycle in ephemeral streams to large flood events

    Science.gov (United States)

    Larsen, J.; Shutova, Y.; Hartland, A.; Andersen, M. S.; Baker, A.; O'Carroll, D. M.

    2012-12-01

    The supply, transport, and cycling of dissolved organic carbon (DOC) within river systems is a critical component of the carbon cycle, determines freshwater ecosystem primary productivity, and is a key driver of water quality through associated redox transformations. Despite this importance, there is very little understanding of how both the concentration and quality of DOC are influenced by natural variations in hydrology, particularly extreme events such as floods, and within different climatic zones. In this study, we examined the evolution of DOC within an ephemeral catchment in semi-arid Australia during a 1:20 year flood event. Total DOC concentrations increased ~3 fold compared to pre-flood concentrations, with peak concentrations occurring in the rising limb of the hydrograph, similar to previous studies of event based DOC. Although we found the DOC to be dominated by Humic substances, the behaviour of the Humic fraction more closely followed the flood hydrograph, suggesting there is a contrast between the large pool of DOC that can be released quickly at the beginning of an event, and DOC which is transported and mixed within the actual flood wave. We also analysed the fluorescence characteristics of the dissolved organic matter, which provides insights into the ability of micro-organisms to process DOC within floods, and also how these systems respond during flow recession. In terms of the total DOC budget, this one event accounts for ~ 6 times the mean annual DOC export of this catchment, within 2% of the time. This work extends our knowledge of riverine DOC fluxes to ephemeral environments, and highlights the potential importance of extreme events to ecosystem carbon processing.

  2. The 2014 coral bleaching and freshwater flood events in Kāneʻohe Bay, Hawaiʻi

    Directory of Open Access Journals (Sweden)

    Keisha D. Bahr

    2015-08-01

    Full Text Available Until recently, subtropical Hawaiʻi escaped the major bleaching events that have devastated many tropical regions, but the continued increases in global long-term mean temperatures and the apparent ending of the Pacific Decadal Oscillation (PDO cool phase have increased the risk of bleaching events. Climate models and observations predict that bleaching in Hawaiʻi will occur with increasing frequency and increasing severity over future decades. A freshwater “kill” event occurred during July 2014 in the northern part of Kāneʻohe Bay that reduced coral cover by 22.5% in the area directly impacted by flooding. A subsequent major bleaching event during September 2014 caused extensive coral bleaching and mortality throughout the bay and further reduced coral cover in the freshwater kill area by 60.0%. The high temperature bleaching event only caused a 1.0% reduction in live coral throughout the portion of the bay not directly impacted by the freshwater event. Thus, the combined impact of the low salinity event and the thermal bleaching event appears to be more than simply additive. The temperature regime during the September 2014 bleaching event was analogous in duration and intensity to that of the large bleaching event that occurred previously during August 1996, but resulted in a much larger area of bleaching and coral mortality. Apparently seasonal timing as well as duration and magnitude of heating is important. Coral spawning in the dominant coral species occurs early in the summer, so reservoirs of stored lipid in the corals had been depleted by spawning prior to the September 2014 event. Warm months above 27 °C result in lower coral growth and presumably could further decrease lipid reserves, leading to a bleaching event that was more severe than would have happened if the high temperatures occurred earlier in the summer. Hawaiian reef corals decrease skeletal growth at temperatures above 27 °C, so perhaps the “stress period

  3. Impact of climate change on New York City's coastal flood hazard: Increasing flood heights from the preindustrial to 2300 CE

    Science.gov (United States)

    Garner, Andra J.; Mann, Michael E.; Emanuel, Kerry A.; Kopp, Robert E.; Lin, Ning; Alley, Richard B.; Horton, Benjamin P.; DeConto, Robert M.; Donnelly, Jeffrey P.; Pollard, David

    2017-11-01

    The flood hazard in New York City depends on both storm surges and rising sea levels. We combine modeled storm surges with probabilistic sea-level rise projections to assess future coastal inundation in New York City from the preindustrial era through 2300 CE. The storm surges are derived from large sets of synthetic tropical cyclones, downscaled from RCP8.5 simulations from three CMIP5 models. The sea-level rise projections account for potential partial collapse of the Antarctic ice sheet in assessing future coastal inundation. CMIP5 models indicate that there will be minimal change in storm-surge heights from 2010 to 2100 or 2300, because the predicted strengthening of the strongest storms will be compensated by storm tracks moving offshore at the latitude of New York City. However, projected sea-level rise causes overall flood heights associated with tropical cyclones in New York City in coming centuries to increase greatly compared with preindustrial or modern flood heights. For the various sea-level rise scenarios we consider, the 1-in-500-y flood event increases from 3.4 m above mean tidal level during 1970–2005 to 4.0–5.1 m above mean tidal level by 2080–2100 and ranges from 5.0–15.4 m above mean tidal level by 2280–2300. Further, we find that the return period of a 2.25-m flood has decreased from ˜500 y before 1800 to ˜25 y during 1970–2005 and further decreases to ˜5 y by 2030–2045 in 95% of our simulations. The 2.25-m flood height is permanently exceeded by 2280–2300 for scenarios that include Antarctica's potential partial collapse.

  4. Visualization of the Impact of the Catastrophic Flooding Events

    DEFF Research Database (Denmark)

    Mioc, Darka; Anton, François; Moreri, K. K.

    The use of advanced tools for computation and modelling of natural hazards can be combined with a GIS that has the capability of decision support and advanced visualization to produce models, that will represent the risks of natural hazards and man-made disasters in the form of risk maps, where...

  5. Global Warming Impact: Flood Events, Wet-Dry Conditions and ...

    African Journals Online (AJOL)

    Agriculture is weather-dependent so a significant alteration in the world climate would cause lot of changes in agricultural practice and agricultural productivity in the world. For man to feed himself adequately man must adjust his food production activities in line with the changes in the weather and climate. This paper ...

  6. Evaluating resilience of DNP3-controlled SCADA systems against event buffer flooding

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Guanhua [Los Alamos National Laboratory; Nicol, David M [UNIV OF IL; Jin, Dong [UNIV OF IL

    2010-12-16

    The DNP3 protocol is widely used in SCADA systems (particularly electrical power) as a means of communicating observed sensor state information back to a control center. Typical architectures using DNP3 have a two level hierarchy, where a specialized data aggregator device receives observed state from devices within a local region, and the control center collects the aggregated state from the data aggregator. The DNP3 communication between control center and data aggregator is asynchronous with the DNP3 communication between data aggregator and relays; this leads to the possibility of completely filling a data aggregator's buffer of pending events, when a relay is compromised or spoofed and sends overly many (false) events to the data aggregator. This paper investigates how a real-world SCADA device responds to event buffer flooding. A Discrete-Time Markov Chain (DTMC) model is developed for understanding this. The DTMC model is validated by a Moebius simulation model and data collected on real SCADA testbed.

  7. Characterizing Drought and Flood Events over the Yangtze River Basin Using the HUST-Grace2016 Solution and Ancillary Data

    Directory of Open Access Journals (Sweden)

    Hao Zhou

    2017-10-01

    Full Text Available Accurate terrestrial water storage (TWS estimation is important to evaluate the situation of the water resources over the Yangtze River Basin (YRB. This study exploits the TWS observation from the new temporal gravity field model, HUST-Grace2016 (Huazhong University of Science and Technology, which is developed by a new low-frequency noise processing strategy. A novel GRACE (Gravity Recovery and Climate Experiment post-processing approach is proposed to enhance the quality of the TWS estimate, and the improved TWS is used to characterize the drought and flood events over the YRB. The HUST-Grace2016-derived TWS presents good agreement with the CSR (Center for Space Research mascon solution as well as the PCR-GLOBWB (PCRaster Global Water Balance hydrological model. Particularly, our solution provides remarkable performance in identifying the extreme climate events e.g., flood and drought over the YRB and its sub-basins. The comparison between GRACE-derived TWS variations and the MODIS-derived (Moderate Resolution Imaging Spectroradiometer inundated area variations is then conducted. The analysis demonstrates that the terrestrial reflectance data can provide an alternative way of cross-comparing and validating TWS information in Poyang Lake and Dongting Lake, with a correlation coefficient of 0.77 and 0.70, respectively. In contrast, the correlation is only 0.10 for Tai Lake, indicating the limitation of cross-comparison between MODIS and GRACE data. In addition, for the first time, the NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research vertical velocity data is incorporated with GRACE TWS in the exploration of the climate-induced hydrological activities. The good agreement between non-seasonal NCEP/NCAR vertical velocities and non-seasonal GRACE TWSs is found in flood years (2005, 2010, 2012 and 2016 and drought years (2006, 2011 and 2013. The evidence shown in this study may contribute to the

  8. Human impacts of droughts, floods and other extremes in South Moravia

    Science.gov (United States)

    Dolák, Lukáš; Brázdil, Rudolf; Řezníčková, Ladislava; Valášek, Hubert; Chromá, Kateřina

    2015-04-01

    Chronicles and taxation records related to tax relief for farmers whose livelihoods were affected by droughts, floods and other hydrometeorological extremes (HMEs) in South Moravia (the Czech Republic) in the 17th-20th centuries are used to study the impacts of HMEs on the socio-economic situation of the farmers. The first flood event was reported in 1652 on the River Morava and extraordinary dry years were documented since 1718 - in this year the River Dyje totally dried up. Moreover, downpours, hailstorms, windstorms, late frosts and blizzards caused a great damage during the period studied as well and in many cases had a negative effect to human society. The impacts of HMEs are here classified into three categories: agricultural production, material property and the socio-economic situation of individual farmers. Direct impacts took the form of losses to property, supplies and farming equipment, and further of bad field and fruit yields, depletion of livestock, damage to fields and meadows, lack of water for daily use, watermills and transport and increased threat of wildfires. Simple lack of income, debt, impoverishment, reduction in livestock and deterioration in field fertility were among the longer-term effects. Impacts are discussed with respect to approaches to mitigation of the negative effects of HMEs and to problems associated with obtaining support and in terms of a hierarchy of consequent impacts. A great number of records related to HMEs, preserved in the Moravian Land Archives in Brno and other district South Moravian archives, represents a rich source of data allowing re-discovering of historical natural disasters. The paper embodies a methodological approach that is intended for the analysis of HME impacts in South Moravia from the 17th to the 20th centuries.

  9. Comparison of the impacts of urban development and climate change on exposing European cities to pluvial flooding

    Directory of Open Access Journals (Sweden)

    P. Skougaard Kaspersen

    2017-08-01

    Full Text Available The economic and human consequences of extreme precipitation and the related flooding of urban areas have increased rapidly over the past decades. Some of the key factors that affect the risks to urban areas include climate change, the densification of assets within cities and the general expansion of urban areas. In this paper, we examine and compare quantitatively the impact of climate change and recent urban development patterns on the exposure of four European cities to pluvial flooding. In particular, we investigate the degree to which pluvial floods of varying severity and in different geographical locations are influenced to the same extent by changes in urban land cover and climate change. We have selected the European cities of Odense, Vienna, Strasbourg and Nice for analyses to represent different climatic conditions, trends in urban development and topographical characteristics. We develop and apply a combined remote-sensing and flood-modelling approach to simulate the extent of pluvial flooding for a range of extreme precipitation events for historical (1984 and present-day (2014 urban land cover and for two climate-change scenarios (i.e. representative concentration pathways, RCP 4.5 and RCP 8.5. Changes in urban land cover are estimated using Landsat satellite imagery for the period 1984–2014. We combine the remote-sensing analyses with regionally downscaled estimates of precipitation extremes of current and expected future climate to enable 2-D overland flow simulations and flood-hazard assessments. The individual and combined impacts of urban development and climate change are quantified by examining the variations in flooding between the different simulations along with the corresponding uncertainties. In addition, two different assumptions are examined with regards to the development of the capacity of the urban drainage system in response to urban development and climate change. In the stationary approach, the capacity

  10. Comparison of the impacts of urban development and climate change on exposing European cities to pluvial flooding

    Science.gov (United States)

    Skougaard Kaspersen, Per; Høegh Ravn, Nanna; Arnbjerg-Nielsen, Karsten; Madsen, Henrik; Drews, Martin

    2017-08-01

    The economic and human consequences of extreme precipitation and the related flooding of urban areas have increased rapidly over the past decades. Some of the key factors that affect the risks to urban areas include climate change, the densification of assets within cities and the general expansion of urban areas. In this paper, we examine and compare quantitatively the impact of climate change and recent urban development patterns on the exposure of four European cities to pluvial flooding. In particular, we investigate the degree to which pluvial floods of varying severity and in different geographical locations are influenced to the same extent by changes in urban land cover and climate change. We have selected the European cities of Odense, Vienna, Strasbourg and Nice for analyses to represent different climatic conditions, trends in urban development and topographical characteristics. We develop and apply a combined remote-sensing and flood-modelling approach to simulate the extent of pluvial flooding for a range of extreme precipitation events for historical (1984) and present-day (2014) urban land cover and for two climate-change scenarios (i.e. representative concentration pathways, RCP 4.5 and RCP 8.5). Changes in urban land cover are estimated using Landsat satellite imagery for the period 1984-2014. We combine the remote-sensing analyses with regionally downscaled estimates of precipitation extremes of current and expected future climate to enable 2-D overland flow simulations and flood-hazard assessments. The individual and combined impacts of urban development and climate change are quantified by examining the variations in flooding between the different simulations along with the corresponding uncertainties. In addition, two different assumptions are examined with regards to the development of the capacity of the urban drainage system in response to urban development and climate change. In the stationary approach, the capacity resembles present

  11. Forensic hydro-meteorological analysis of an extreme flash flood: The 2016-05-29 event in Braunsbach, SW Germany.

    Science.gov (United States)

    Bronstert, Axel; Agarwal, Ankit; Boessenkool, Berry; Crisologo, Irene; Fischer, Madlen; Heistermann, Maik; Köhn-Reich, Lisei; López-Tarazón, José Andrés; Moran, Thomas; Ozturk, Ugur; Reinhardt-Imjela, Christian; Wendi, Dadiyorto

    2018-02-28

    The flash-flood in Braunsbach in the north-eastern part of Baden-Wuerttemberg/Germany was a particularly strong and concise event which took place during the floods in southern Germany at the end of May/early June 2016. This article presents a detailed analysis of the hydro-meteorological forcing and the hydrological consequences of this event. A specific approach, the "forensic hydrological analysis" was followed in order to include and combine retrospectively a variety of data from different disciplines. Such an approach investigates the origins, mechanisms and course of such natural events if possible in a "near real time" mode, in order to follow the most recent traces of the event. The results show that it was a very rare rainfall event with extreme intensities which, in combination with catchment properties, led to extreme runoff plus severe geomorphological hazards, i.e. great debris flows, which together resulted in immense damage in this small rural town Braunsbach. It was definitely a record-breaking event and greatly exceeded existing design guidelines for extreme flood discharge for this region, i.e. by a factor of about 10. Being such a rare or even unique event, it is not reliably feasible to put it into a crisp probabilistic context. However, one can conclude that a return period clearly above 100years can be assigned for all event components: rainfall, peak discharge and sediment transport. Due to the complex and interacting processes, no single flood cause or reason for the very high damage can be identified, since only the interplay and the cascading characteristics of those led to such an event. The roles of different human activities on the origin and/or intensification of such an extreme event are finally discussed. Copyright © 2018. Published by Elsevier B.V.

  12. Impacts of the 2016 outburst flood on the Bhote Koshi River valley, central Nepal

    Science.gov (United States)

    Cook, Kristen; Andermann, Christoff; Gimbert, Florent; Hovius, Niels; Adhikari, Basanta

    2017-04-01

    The central Nepal Himalaya is a region of rapid erosion where fluvial processes are largely driven by the annual Indian Summer Monsoon, which delivers up to several meters of precipitation each year. However, the rivers in this region are also subject to rare catastrophic floods caused by the sudden failure of landslide or moraine dams. Because these floods happen rarely, it has been difficult to isolate their impact on the rivers and adjacent hillslopes, and their importance for the long-term evolution of Himalayan rivers is poorly constrained. On the 5th of July, 2016, the Bhote Koshi River in central Nepal was hit by a glacial lake outburst flood (GLOF). The flood passed through a seismic and hydrological observatory installed along the river in June 2015, and we have used the resulting data to constrain the timing, duration, and bedload transport properties of the outburst flood. The impact of the flood on the river can be further observed with hourly time-lapse photographs, daily measurements of suspended sediment load, repeat lidar surveys, and satellite imagery. Overall, our observatory data span two monsoon seasons, allowing us to evaluate the impacts of the outburst flood relative to the annual monsoon flood. The outburst flood affected the river on several timescales. In the short term, it transported large amounts of coarse sediment and restructured the river bed during the hours of the flood pulse itself. Over intermediate timescales it resulted in elevated bedload and suspended load transport for several weeks following the flood. Over longer timescales the flood undercut and destabilized the river banks and hillslopes in a number of locations, leading to bank collapses, slumps, and landslides. We map changes in the channel and associated mass wasting using rapidEye imagery from Oct. 2015 and Oct. 2016. We also use repeat terrestrial lidar scans to quantify the magnitude of change in multiple locations along the river channel and to measure bank

  13. Real-time forecasts of flood hazard and impact: some UK experiences

    Directory of Open Access Journals (Sweden)

    Cole Steven J.

    2016-01-01

    Full Text Available Major UK floods over the last decade have motivated significant technological and scientific advances in operational flood forecasting and warning. New joint forecasting centres between the national hydrological and meteorological operating agencies have been formed that issue a daily, national Flood Guidance Statement (FGS to the emergency response community. The FGS is based on a Flood Risk Matrix approach that is a function of potential impact severity and likelihood. It has driven an increased demand for robust, accurate and timely forecast and alert information on fluvial and surface water flooding along with impact assessments. The Grid-to-Grid (G2G distributed hydrological model has been employed across Britain at a 1km resolution to support the FGS. Novel methods for linking dynamic gridded estimates of river flow and surface runoff with more detailed offline flood risk maps have been developed to obtain real-time probabilistic forecasts of potential impacts, leading to operational trials. Examples of the national-scale G2G application are provided along with case studies of forecast flood impact from (i an operational Surface Water Flooding (SWF trial during the Glasgow 2014 Commonwealth Games, (ii SWF developments under the Natural Hazards Partnership over England & Wales, and (iii fluvial applications in Scotland.

  14. Impact of Flood on the Biodiversity of Agodi Gardens, Ibadan ...

    African Journals Online (AJOL)

    The study of flood effect on the species diversity in Agodi Biological Gardens was carried out to determine the rate of devastation that the catastrophes of 30 August 2011 flood disaster caused on the ex-situ environment. Both physicochemical parameters and structured questionnaire were used to assess the rate of ...

  15. Impact of climate change on flood characteristics in Brahmaputra ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... In order to assess the flood characteristics at the basin and tributary scales, a physically based macro-scale distributed hydrological model (DHM) has been calibrated and validated for 9 wet years. The model performance has been evaluated in terms of prediction of the flood characteristics such as peak ...

  16. The October 2015 flash-floods in south eastern France: hydrological analyses, inundation mapping and impact estimations

    Science.gov (United States)

    Payrastre, Olivier; Bourgin, François; Lebouc, Laurent; Le Bihan, Guillaume; Gaume, Eric

    2017-04-01

    The October 2015 flash-floods in south eastern France caused more than twenty fatalities, high damages and large economic losses in high density urban areas of the Mediterranean coast, including the cities of Mandelieu-La Napoule, Cannes and Antibes. Following a post event survey and preliminary analyses conducted within the framework of the Hymex project, we set up an entire simulation chain at the regional scale to better understand this outstanding event. Rainfall-runoff simulations, inundation mapping and a first estimation of the impacts are conducted following the approach developed and successfully applied for two large flash-flood events in two different French regions (Gard in 2002 and Var in 2010) by Le Bihan (2016). A distributed rainfall-runoff model applied at high resolution for the whole area - including numerous small ungauged basins - is used to feed a semi-automatic hydraulic approach (Cartino method) applied along the river network - including small tributaries. Estimation of the impacts is then performed based on the delineation of the flooded areas and geographic databases identifying buildings and population at risk.

  17. Accessibility assessment of Houston's roadway network during Harvey through integration of observed flood impacts and hydrologic modeling

    Science.gov (United States)

    Gidaris, I.; Gori, A.; Panakkal, P.; Padgett, J.; Bedient, P. B.

    2017-12-01

    The record-breaking rainfall produced over the Houston region by Hurricane Harvey resulted in catastrophic and unprecedented impacts on the region's infrastructure. Notably, Houston's transportation network was crippled, with almost every major highway flooded during the five-day event. Entire neighborhoods and subdivisions were inundated, rendering them completely inaccessible to rescue crews and emergency services. Harvey has tragically highlighted the vulnerability of major thoroughfares, as well as neighborhood roads, to severe inundation during extreme precipitation events. Furthermore, it has emphasized the need for detailed accessibility characterization of road networks under extreme event scenarios in order to determine which areas of the city are most vulnerable. This analysis assesses and tracks the accessibility of Houston's major highways during Harvey's evolution by utilizing road flood/closure data from the Texas DOT. In the absence of flooded/closure data for local roads, a hybrid approach is adopted that utilizes a physics-based hydrologic model to produce high-resolution inundation estimates for selected urban watersheds in the Houston area. In particular, hydrologic output in the form of inundation depths is used to estimate the operability of local roads. Ultimately, integration of hydrologic-based estimation of road conditions with observed data from DOT supports a network accessibility analysis of selected urban neighborhoods. This accessibility analysis can identify operable routes for emergency response (rescue crews, medical services, etc.) during the storm event.

  18. Moisture Sources and Large-Scale Dynamics Associated with a Flash Flood Event in Portugal

    Science.gov (United States)

    Liberato, Margarida L. R.; Ramos, Alexandre M.; Trigo, Ricardo M.; Trigo, Isabel F.; María Durán-Quesada, Ana; Nieto, Raquel; Gimeno, Luis

    2013-04-01

    On 18-19 November 1983, the region of Lisbon, in Portugal, was affected by a heavy precipitation event, soon followed by flash flooding, urban inundations and a burst of landslides around Lisbon [Zêzere et al., 2005] causing considerable infrastructure damage and human fatalities. With a total of 95.6 mm in 24 h observed at the longest serving station in Portugal (Lisbon's Dom Luiz Observatory), this was the rainiest day during the twentieth century and one of the rainiest registered since 1864. We found that this event was triggered by the transport of tropical and subtropical moisture associated with an extratropical cyclone. The low favored a large stream of (sub) tropical air that extended over more than 10° of latitude and across the North Atlantic Ocean, carrying a large amount of moisture originally from lower latitudes, a so-called atmospheric river. The stationary position of the jet stream along the East Atlantic Ocean through Iberia caused a strong enhancement of the precipitation associated with the moist air. A Lagrangian analysis of the transport of moisture in the Euro-Atlantic sector was performed based on the methodology developed by Stohl and James [2004, 2005], using the FLEXPART model. This Lagrangian methodology was employed to show that the evaporative sources for the precipitation falling over the area of Lisbon were distributed over large sectors of the tropical-subtropical North Atlantic Ocean and included a significant contribution from the (sub) tropics. This study [Liberato et al., 2012] aims to provide an example of the application of distinct Lagrangian techniques to achieve a better understanding of the relation between extratropical cyclones and the occurrence of a heavy precipitation event on the Iberian Peninsula. Acknowledgments: This work was partially supported by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE (Programa Operacional Factores de Competitividade) Programme and by national funds

  19. An observational and numerical study of a flash-flood event over south-eastern Italy

    Directory of Open Access Journals (Sweden)

    M. M. Miglietta

    2008-12-01

    Full Text Available A flash-flood episode affecting a small area in Apulia (south-eastern Italy on 22 October 2005 is documented. A rainfall amount of 160 mm was recorded in a 6 h interval in the central part of the region, producing severe damage and causing six fatalities. Synoptic maps, observations from surface stations and remote-sensing data are used here to describe the evolution of the rainfall system. The vertical profiles show features similar to those observed in other orographic heavy-rain events, such as a low-level jet, a conditionally unstable environment, and a nearly saturated warm low-level air mass. The low hills in the centre of the region play an important role in the release of the instability and the localisation of the rainfall, providing the uplift necessary to the air parcels to reach the level of free convection. Numerical simulations are performed in order to understand the mechanisms responsible for the heavy rain event. The Weather Research and Forecasting model (WRF is setup in a 2-way nesting configuration including two domains. The model is able to realistically simulate the evolution of the precipitation system and to capture fairly well the localisation, the amount and the timing of the rainfall. The simulations suggest the important synergy of low and upper-tropospheric features which act as the triggering mechanism for the development of convection. A sensitivity experiment confirms the importance of the orography for the development of convective cells.

  20. Towards a Flood Severity Index

    Science.gov (United States)

    Kettner, A.; Chong, A.; Prades, L.; Brakenridge, G. R.; Muir, S.; Amparore, A.; Slayback, D. A.; Poungprom, R.

    2017-12-01

    Flooding is the most common natural hazard worldwide, affecting 21 million people every year. In the immediate moments following a flood event, humanitarian actors like the World Food Program need to make rapid decisions ( 72 hrs) on how to prioritize affected areas impacted by such an event. For other natural disasters like hurricanes/cyclones and earthquakes, there are industry-recognized standards on how the impacted areas are to be classified. Shake maps, quantifying peak ground motion, from for example the US Geological Survey are widely used for assessing earthquakes. Similarly, cyclones are tracked by Joint Typhoon Warning Center (JTWC) and Global Disaster Alert and Coordination System (GDACS) who release storm nodes and tracks (forecasted and actual), with wind buffers and classify the event according to the Saffir-Simpson Hurricane Wind Scale. For floods, the community is usually able to acquire unclassified data of the flood extent as identified from satellite imagery. Most often no water discharge hydrograph is available to classify the event into recurrence intervals simply because there is no gauging station, or the gauging station was unable to record the maximum discharge due to overtopping or flood damage. So, the question remains: How do we methodically turn a flooded area into classified areas of different gradations of impact? Here, we present a first approach towards developing a global applicable flood severity index. The flood severity index is set up such that it considers relatively easily obtainable physical parameters in a short period of time like: flood frequency (relating the current flood to historical events) and magnitude, as well as land cover, slope, and where available pre-event simulated flood depth. The scale includes categories ranging from very minor flooding to catastrophic flooding. We test and evaluate the postulated classification scheme against a set of past flood events. Once a severity category is determined, socio

  1. Impacts of extreme weather events on transport infrastructure in Norway

    Science.gov (United States)

    Frauenfelder, Regula; Solheim, Anders; Isaksen, Ketil; Romstad, Bård; Dyrrdal, Anita V.; Ekseth, Kristine H. H.; Gangstø Skaland, Reidun; Harbitz, Alf; Harbitz, Carl B.; Haugen, Jan E.; Hygen, Hans O.; Haakenstad, Hilde; Jaedicke, Christian; Jónsson, Árni; Klæboe, Ronny; Ludvigsen, Johanna; Meyer, Nele K.; Rauken, Trude; Sverdrup-Thygeson, Kjetil

    2016-04-01

    With the latest results on expected future increase in air temperature and precipitation changes reported by the Intergovernmental Panel on Climate Change (IPCC), the climate robustness of important infrastructure is of raising concern in Norway, as well as in the rest of Europe. Economic consequences of natural disasters have increased considerably since 1950. In addition to the effect of demographic changes such as population growth, urbanization and more and more concentration of valuable assets, this increase is also related to an augmenting frequency of extreme events, such as storms, flooding, drought, and landslides. This change is also observable in Norway, where the increased frequency of strong precipitation has led to frequent flooding and landslide events during the last 20 years. A number of studies show that climate change causes an increase in both frequency and intensity of several types of extreme weather, especially when it comes to precipitation. Such extreme weather events greatly affect the transport infrastructure, with numerous and long closures of roads and railroads, in addition to damage and repair costs. Frequent closures of railroad and roads lead to delay or failure in delivery of goods, which again may lead to a loss of customers and/or - eventually - markets. Much of the Norwegian transport infrastructure is more than 50 years old and therefore not adequately dimensioned, even for present climatic conditions. In order to assess these problems and challenges posed to the Norwegian transport infrastructure from present-day and future extreme weather events, the project "Impacts of extreme weather events on infrastructure in Norway (InfraRisk)" was performed under the research Council of Norway program 'NORKLIMA', between 2009 and 2013. The main results of the project are: - Moderate to strong precipitation events have become more frequent and more intense in Norway over the last 50 years, and this trend continues throughout the 21st

  2. Climate change impact assessment of extreme precipitation on urban flash floods – case study, Aarhus, Denmark

    DEFF Research Database (Denmark)

    Madsen, Henrik; Sunyer Pinya, Maria Antonia; Rosbjerg, Dan

    Climate change is expected to cause more intense extreme rainfall events, which will have a severe impact on the risk of flash floods in urban areas. An assessment study was performed for the city of Aarhus, Denmark, analysing different methods of statistical downscaling of climate model...... projections for estimation of changes in extreme rainfall characteristics. Climate model projections from 20 regional climate models (RCM) from the ENSEMBLES data archive were used in the analysis. Two different estimation methods were applied, using, respectively, a direct estimation of the changes...... in the extreme value statistics of the RCM data, and application of a stochastic weather generator fitted to the changes in rainfall characteristics from the RCM data. The results show a large variability in the projected changes in extreme precipitation between the different RCMs and the two estimation methods...

  3. Forecasting Flood Hazard on Real Time: Implementation of a New Surrogate Model for Hydrometeorological Events in an Andean Watershed.

    Science.gov (United States)

    Contreras Vargas, M. T.; Escauriaza, C. R.; Westerink, J. J.

    2017-12-01

    In recent years, the occurrence of flash floods and landslides produced by hydrometeorological events in Andean watersheds has had devastating consequences in urban and rural areas near the mountains. Two factors have hindered the hazard forecast in the region: 1) The spatial and temporal variability of climate conditions, which reduce the time range that the storm features can be predicted; and 2) The complexity of the basin morphology that characterizes the Andean region, and increases the velocity and the sediment transport capacity of flows that reach urbanized areas. Hydrodynamic models have become key tools to assess potential flood risks. Two-dimensional (2D) models based on the shallow-water equations are widely used to determine with high accuracy and resolution, the evolution of flow depths and velocities during floods. However, the high-computational requirements and long computational times have encouraged research to develop more efficient methodologies for predicting the flood propagation on real time. Our objective is to develop new surrogate models (i.e. metamodeling) to quasi-instantaneously evaluate floods propagation in the Andes foothills. By means a small set of parameters, we define storms for a wide range of meteorological conditions. Using a 2D hydrodynamic model coupled in mass and momentum with the sediment concentration, we compute on high-fidelity the propagation of a flood set. Results are used as a database to perform sophisticated interpolation/regression, and approximate efficiently the flow depth and velocities in critical points during real storms. This is the first application of surrogate models to evaluate flood propagation in the Andes foothills, improving the efficiency of flood hazard prediction. The model also opens new opportunities to improve early warning systems, helping decision makers to inform citizens, enhancing the reslience of cities near mountain regions. This work has been supported by CONICYT/FONDAP grant

  4. The impact of uncertain precipitation data on insurance loss estimates using a flood catastrophe model

    Science.gov (United States)

    Sampson, C. C.; Fewtrell, T. J.; O'Loughlin, F.; Pappenberger, F.; Bates, P. B.; Freer, J. E.; Cloke, H. L.

    2014-06-01

    Catastrophe risk models used by the insurance industry are likely subject to significant uncertainty, but due to their proprietary nature and strict licensing conditions they are not available for experimentation. In addition, even if such experiments were conducted, these would not be repeatable by other researchers because commercial confidentiality issues prevent the details of proprietary catastrophe model structures from being described in public domain documents. However, such experimentation is urgently required to improve decision making in both insurance and reinsurance markets. In this paper we therefore construct our own catastrophe risk model for flooding in Dublin, Ireland, in order to assess the impact of typical precipitation data uncertainty on loss predictions. As we consider only a city region rather than a whole territory and have access to detailed data and computing resources typically unavailable to industry modellers, our model is significantly more detailed than most commercial products. The model consists of four components, a stochastic rainfall module, a hydrological and hydraulic flood hazard module, a vulnerability module, and a financial loss module. Using these we undertake a series of simulations to test the impact of driving the stochastic event generator with four different rainfall data sets: ground gauge data, gauge-corrected rainfall radar, meteorological reanalysis data (European Centre for Medium-Range Weather Forecasts Reanalysis-Interim; ERA-Interim) and a satellite rainfall product (The Climate Prediction Center morphing method; CMORPH). Catastrophe models are unusual because they use the upper three components of the modelling chain to generate a large synthetic database of unobserved and severe loss-driving events for which estimated losses are calculated. We find the loss estimates to be more sensitive to uncertainties propagated from the driving precipitation data sets than to other uncertainties in the hazard and

  5. Land use change impacts on floods at the catchment scale

    NARCIS (Netherlands)

    Rogger, M.; Agnoletti, M.; Alaoui, A.; Bathurst, J.C.; Bodner, G.; Borga, M.; Chaplot, Vincent; Gallart, F.; Glatzel, G.; Hall, J.; Holden, J.; Holko, L.; Horn, R.; Kiss, A.; Kohnová, S.; Leitinger, G.; Lennartz, B.; Parajka, J.; Perdigão, R.; Peth, S.; Plavcová, L.; Quinton, John N.; Robinson, Matthew R.; Salinas, J.L.; Santoro, A.; Szolgay, J.; Tron, S.; Akker, van den J.J.H.; Viglione, A.; Blöschl, G.

    2017-01-01

    Research gaps in understanding flood changes at the catchment scale caused by changes in forest management, agricultural practices, artificial drainage, and terracing are identified. Potential strategies in addressing these gaps are proposed, such as complex systems approaches to link processes

  6. Impact of external events on site evaluation: a probabilistic approach

    International Nuclear Information System (INIS)

    Jaccarino, E.; Giuliani, P.; Zaffiro, C.

    1975-01-01

    A probabilistic method is proposed for definition of the reference external events of nuclear sites. The external events taken into account are earthquakes, floods and tornadoes. On the basis of the available historical data for each event it is possible to perform statistical analyses to determine the probability of occurrence on site of events of given characteristics. For earthquakes, the method of analysis takes into consideration both the annual frequency of seismic events in Italy and the probabilistic distribution of areas stricken by each event. For floods, the methods of analysis of hydrological data and the basic criteria for the determination of design events are discussed and the general lines of the hydraulic analysis of a nuclear site are shown. For tornadoes, the statistical analysis has been performed for the events which occurred in Italy during the last 40 years; these events have been classified according to an empirical intensity scale. The probability of each reference event should be a function of the potential radiological damage associated with the particular type of plant which must be installed on the site. Thus the reference event could be chosen such that for the whole of the national territory the risk for safety and environmental protection is the same. (author)

  7. Rice flooding negatively impacts root branching and arbuscular mycorrhizal colonization, but not fungal viability.

    Science.gov (United States)

    Vallino, Marta; Fiorilli, Valentina; Bonfante, Paola

    2014-03-01

    Rice is mostly cultivated in wetlands, where arbuscular mycorrhization (AM) is reported to decrease. The mechanisms regulating such events are largely unknown. Rice uninoculated and inoculated with Rhizophagus irregularis were grown in dry and flooded conditions, allowing also for the transfer of plants from one water regime to the other. Roots were sampled at different times, from 7 to 35 d post-inoculation (dpi). The morphological and molecular parameters (root branching, aerenchyma formation, mycorrhizal colonization, AM marker gene expression) were evaluated. Root branching was more pronounced in dry conditions, and such phenotype was enhanced by the fungus. In wetlands, the colonization level was comparable till 21 dpi, when the mycorrhization then decreased, paralleled by an increase in aerenchyma. Expression of the fungal transporters was comparable under the two conditions. The root apparatus, when shifted from one water regime to the other, rapidly adapted to the new condition, revealing a marked plasticity. The reversibility of the AM rice symbiosis was also mirrored by expression changes of plant marker genes. The results demonstrate that the water regime is the driving force that regulates AM colonization under flooding conditions, by directly influencing root architecture and anatomy, but without impacting the basic AM functionality. © 2013 John Wiley & Sons Ltd.

  8. Metagenomic profiling of historic Colorado Front Range flood impact on distribution of riverine antibiotic resistance genes

    Science.gov (United States)

    Garner, Emily; Wallace, Joshua S.; Argoty, Gustavo Arango; Wilkinson, Caitlin; Fahrenfeld, Nicole; Heath, Lenwood S.; Zhang, Liqing; Arabi, Mazdak; Aga, Diana S.; Pruden, Amy

    2016-12-01

    Record-breaking floods in September 2013 caused massive damage to homes and infrastructure across the Colorado Front Range and heavily impacted the Cache La Poudre River watershed. Given the unique nature of this watershed as a test-bed for tracking environmental pathways of antibiotic resistance gene (ARG) dissemination, we sought to determine the impact of extreme flooding on ARG reservoirs in river water and sediment. We utilized high-throughput DNA sequencing to obtain metagenomic profiles of ARGs before and after flooding, and investigated 23 antibiotics and 14 metals as putative selective agents during post-flood recovery. With 277 ARG subtypes identified across samples, total bulk water ARGs decreased following the flood but recovered to near pre-flood abundances by ten months post-flood at both a pristine site and at a site historically heavily influenced by wastewater treatment plants and animal feeding operations. Network analysis of de novo assembled sequencing reads into 52,556 scaffolds identified ARGs likely located on mobile genetic elements, with up to 11 ARGs per plasmid-associated scaffold. Bulk water bacterial phylogeny correlated with ARG profiles while sediment phylogeny varied along the river’s anthropogenic gradient. This rare flood afforded the opportunity to gain deeper insight into factors influencing the spread of ARGs in watersheds.

  9. Impact of modelling scale on probabilistic flood risk assessment: the Malawi case

    Directory of Open Access Journals (Sweden)

    Rudari Roberto

    2016-01-01

    Full Text Available In the early months of 2015, destructive floods hit Malawi, causing deaths and economic losses. Flood risk assessment outcomes can be used to increase scientific-supported awareness of risk. The recent increase in availability of high resolution data such as TanDEM-X at 12m resolution makes possible the use of detailed physical based flood hazard models in risk assessment. Nonetheless the scale of hazard modelling still remains an issue, which requires a compromise between level of detail and computational efforts. This work presents two different approaches on hazard modelling. Both methods rely on 32-years of numeric weather re-analysis and rainfall-runoff transformation through a fully distributed WFLOW-type hydrological model. The first method, applied at national scale, uses fast post-processing routines, which estimate flood water depth at a resolution of about 1×1km. The second method applies a full 2D hydraulic model to propagate water discharge into the flood plains and best suites for small areas where assets are concentrated. At the 12m resolution, three hot spots with a model area of approximately 10×10 km are analysed. Flood hazard maps obtained with both approaches are combined with flood impact models at the same resolution to generate indicators for flood risk. A quantitative comparison of the two approaches is presented in order to show the effects of modelling scale on both hazard and impact losses.

  10. Impacts of future climate change on urban flood volumes in Hohhot in northern China: benefits of climate change mitigation and adaptations

    Directory of Open Access Journals (Sweden)

    Q. Zhou

    2018-01-01

    Full Text Available As China becomes increasingly urbanised, flooding has become a regular occurrence in its major cities. Assessing the effects of future climate change on urban flood volumes is crucial to informing better management of such disasters given the severity of the devastating impacts of flooding (e.g. the 2016 flooding events across China. Although recent studies have investigated the impacts of future climate change on urban flooding, the effects of both climate change mitigation and adaptation have rarely been accounted for together in a consistent framework. In this study, we assess the benefits of mitigating climate change by reducing greenhouse gas (GHG emissions and locally adapting to climate change by modifying drainage systems to reduce urban flooding under various climate change scenarios through a case study conducted in northern China. The urban drainage model – Storm Water Management Model – was used to simulate urban flood volumes using current and two adapted drainage systems (i.e. pipe enlargement and low-impact development, LID, driven by bias-corrected meteorological forcing from five general circulation models in the Coupled Model Intercomparison Project Phase 5 archive. Results indicate that urban flood volume is projected to increase by 52 % over 2020–2040 compared to the volume in 1971–2000 under the business-as-usual scenario (i.e. Representative Concentration Pathway (RCP 8.5. The magnitudes of urban flood volumes are found to increase nonlinearly with changes in precipitation intensity. On average, the projected flood volume under RCP 2.6 is 13 % less than that under RCP 8.5, demonstrating the benefits of global-scale climate change mitigation efforts in reducing local urban flood volumes. Comparison of reduced flood volumes between climate change mitigation and local adaptation (by improving drainage systems scenarios suggests that local adaptation is more effective than climate change mitigation in reducing

  11. Impacts of future climate change on urban flood volumes in Hohhot in northern China: benefits of climate change mitigation and adaptations

    Science.gov (United States)

    Zhou, Qianqian; Leng, Guoyong; Huang, Maoyi

    2018-01-01

    As China becomes increasingly urbanised, flooding has become a regular occurrence in its major cities. Assessing the effects of future climate change on urban flood volumes is crucial to informing better management of such disasters given the severity of the devastating impacts of flooding (e.g. the 2016 flooding events across China). Although recent studies have investigated the impacts of future climate change on urban flooding, the effects of both climate change mitigation and adaptation have rarely been accounted for together in a consistent framework. In this study, we assess the benefits of mitigating climate change by reducing greenhouse gas (GHG) emissions and locally adapting to climate change by modifying drainage systems to reduce urban flooding under various climate change scenarios through a case study conducted in northern China. The urban drainage model - Storm Water Management Model - was used to simulate urban flood volumes using current and two adapted drainage systems (i.e. pipe enlargement and low-impact development, LID), driven by bias-corrected meteorological forcing from five general circulation models in the Coupled Model Intercomparison Project Phase 5 archive. Results indicate that urban flood volume is projected to increase by 52 % over 2020-2040 compared to the volume in 1971-2000 under the business-as-usual scenario (i.e. Representative Concentration Pathway (RCP) 8.5). The magnitudes of urban flood volumes are found to increase nonlinearly with changes in precipitation intensity. On average, the projected flood volume under RCP 2.6 is 13 % less than that under RCP 8.5, demonstrating the benefits of global-scale climate change mitigation efforts in reducing local urban flood volumes. Comparison of reduced flood volumes between climate change mitigation and local adaptation (by improving drainage systems) scenarios suggests that local adaptation is more effective than climate change mitigation in reducing future flood volumes. This has

  12. Using HAZUS-MH for modelling past coastal flooding events in Japan

    Science.gov (United States)

    Robinson, T.; Charvet, I.; Gunasekera, R.

    2012-04-01

    In regions at risk from natural hazards, the ability to pre-determine the vulnerability and exposure of buildings (residential, commercial, industrial and government) from multiple hazard scenarios, allows policy makers and businesses to put forward appropriate policies, planning and intervention methods to mitigate the financial impact. For this purpose, a number of catastrophe models have been developed to provide the decision makers with quantitative risk assessments based on science and engineering knowledge. One of the most sophisticated open source models currently available is HAZUS-MH. The software is a powerful tool for analysing potential losses from floods, hurricane winds, and earthquakes. It was initially designed by FEMA to work with US datasets and has proven to be a great resource for disaster management at both national and local level in order to plan and increase the awareness of the recovery process after a natural disaster. Methodologies have been introduced to export the HAZUS-MH model for global applications. However, currently the international community have been slow to act on this technology breakthrough. The applications of this project will focus on adapting the HAZUS-HM model to provide a reliable vulnerability assessment of Japan's building stock from tsunami flooding. A review of the different methodologies will be carried out and presented as guidance on the best practice. The numerical assessment reports will be compared to real scenarios based on field observations, financial bulletins and government reports. A sensitivity analysis will be carried out on the generation of bespoke datasets based on the quality and density of the available regional data. These results will be compared against results using proxy US datasets. In addition, the significance of regional building standards and practices will be incorporated into the model through the development of new damage functions. The level of confidence and sensitivity (building

  13. Patterns of forest succession and impacts of flood in the Upper Mississippi River floodplain ecosystem

    Science.gov (United States)

    Yin, Y.; Wu, Y.; Bartell, S.M.; Cosgriff, R.

    2009-01-01

    The widespread loss of oak-hickory forests and the impacts of flood have been major issues of ecological interest concerning forest succession in the Upper Mississippi River (UMR) floodplain. The data analysis from two comprehensive field surveys indicated that Quercus was one of the dominant genera in the UMR floodplain ecosystem prior to the 1993 flood and constituted 14% of the total number of trees and 28% of the total basal area. During the post-flood recovery period through 2006, Quercus demonstrated slower recovery rates in both the number of trees (4%) and basal area (17%). In the same period, Carya recovered greatly from the 1993 flood in terms of the number of trees (11%) and basal area (2%), compared to its minor status before the flood. Further analyses suggested that different species responded to the 1993 flood with varying tolerance and different succession strategies. In this study, the relation of flood-caused mortality rates and DBH, fm(d), can be expressed in negative exponential functions for each species. The results of this research also indicate that the growth functions are different for each species and might also be different between pre- and post-flood time periods. These functions indicate different survival strategies and emergent properties in responding to flood impacts. This research enhances our understanding of forest succession patterns in space and time in the UPR floodplain. And such understanding might be used to predict long-term impacts of floods on UMR floodplain forest dynamics in support of management and restoration. ?? 2009 Elsevier B.V.

  14. Assessment of the health impacts of the 2011 summer floods in Brisbane.

    Science.gov (United States)

    Alderman, Katarzyna; Turner, Lyle R; Tong, Shilu

    2013-08-01

    To assess the effects of the 2011 floods in Brisbane, Australia, on residents' physical and mental health. Residents who had been affected by the floods completed a community-based survey that examined the direct impact of flooding on households and their perceived physical and mental health. Outcome variables included overall and respiratory health and mental health outcomes related to psychological distress, sleep quality, and posttraumatic stress disorder (PTSD). Multivariable logistic regression was used to examine the association between flooding and perceived health outcome variables, adjusted for current health status and sociodemographic factors. Residents whose households were directly affected by flooding were more likely to report poor overall (Odds Ratio [OR] 5.3; 95% CI, 2.8-10.1) and respiratory (OR 2.3; 95% CI, 1.1-4.6) health, psychological distress (OR 1.9; 95% CI, 1.1-3.5), poor sleep quality (OR 2.3; 95% CI, 1.2-4.4), and probable PTSD (OR 2.3; 95% CI, 1.2-4.5). The 2011 Brisbane floods had significant impact on the physical and psychosocial health of residents. Improved support strategies may need to be integrated into existing disaster management programs to reduce flood-related health impacts, particularly those related to mental health.

  15. Impacts of representing sea-level rise uncertainty on future flood risks: An example from San Francisco Bay.

    Science.gov (United States)

    Ruckert, Kelsey L; Oddo, Perry C; Keller, Klaus

    2017-01-01

    Rising sea levels increase the probability of future coastal flooding. Many decision-makers use risk analyses to inform the design of sea-level rise (SLR) adaptation strategies. These analyses are often silent on potentially relevant uncertainties. For example, some previous risk analyses use the expected, best, or large quantile (i.e., 90%) estimate of future SLR. Here, we use a case study to quantify and illustrate how neglecting SLR uncertainties can bias risk projections. Specifically, we focus on the future 100-yr (1% annual exceedance probability) coastal flood height (storm surge including SLR) in the year 2100 in the San Francisco Bay area. We find that accounting for uncertainty in future SLR increases the return level (the height associated with a probability of occurrence) by half a meter from roughly 2.2 to 2.7 m, compared to using the mean sea-level projection. Accounting for this uncertainty also changes the shape of the relationship between the return period (the inverse probability that an event of interest will occur) and the return level. For instance, incorporating uncertainties shortens the return period associated with the 2.2 m return level from a 100-yr to roughly a 7-yr return period (∼15% probability). Additionally, accounting for this uncertainty doubles the area at risk of flooding (the area to be flooded under a certain height; e.g., the 100-yr flood height) in San Francisco. These results indicate that the method of accounting for future SLR can have considerable impacts on the design of flood risk management strategies.

  16. Impacts of representing sea-level rise uncertainty on future flood risks: An example from San Francisco Bay.

    Directory of Open Access Journals (Sweden)

    Kelsey L Ruckert

    Full Text Available Rising sea levels increase the probability of future coastal flooding. Many decision-makers use risk analyses to inform the design of sea-level rise (SLR adaptation strategies. These analyses are often silent on potentially relevant uncertainties. For example, some previous risk analyses use the expected, best, or large quantile (i.e., 90% estimate of future SLR. Here, we use a case study to quantify and illustrate how neglecting SLR uncertainties can bias risk projections. Specifically, we focus on the future 100-yr (1% annual exceedance probability coastal flood height (storm surge including SLR in the year 2100 in the San Francisco Bay area. We find that accounting for uncertainty in future SLR increases the return level (the height associated with a probability of occurrence by half a meter from roughly 2.2 to 2.7 m, compared to using the mean sea-level projection. Accounting for this uncertainty also changes the shape of the relationship between the return period (the inverse probability that an event of interest will occur and the return level. For instance, incorporating uncertainties shortens the return period associated with the 2.2 m return level from a 100-yr to roughly a 7-yr return period (∼15% probability. Additionally, accounting for this uncertainty doubles the area at risk of flooding (the area to be flooded under a certain height; e.g., the 100-yr flood height in San Francisco. These results indicate that the method of accounting for future SLR can have considerable impacts on the design of flood risk management strategies.

  17. Impact of Floods on Livelihoods and Vulnerability of Natural Resource Dependent Communities in Northern Ghana

    Directory of Open Access Journals (Sweden)

    Frederick A. Armah

    2010-04-01

    Full Text Available Sub-Sahara Africa is considered to be most vulnerable to climate variability including flooding. The frequency and severity of floods in Northern Ghana over the last decade has increased considerably. Through qualitative modelling the paper explores the impact of floods on natural resource dependent communities in Northern Ghana. Simplified causal loop diagrams are used to conceptualise flood-induced coping strategies in the study area. The results indicate that some characteristics of the socio-cultural environment appear to mitigate risk and reduce vulnerability. In this context, the role of social networks in enhancing livelihood security is essential. The paper concludes that both in case of seasonal variations in agricultural output and floods, individuals that have effectively diversified their livelihoods, both occupationally and geographically, are less sensitive than individuals who mainly achieve entitlement to food via crop cultivation. However, diversification in this case, is effective only in the short term.

  18. Geostatistical screening of flood events in the groundwater levels of the diverted inner delta of the Danube River: implications for river bed clogging

    Science.gov (United States)

    Trásy, Balázs; Garamhegyi, Tamás; Laczkó-Dobos, Péter; Kovács, József; Hatvani, István Gábor

    2018-04-01

    The efficient operation of shallow groundwater (SGW) monitoring networks is crucial to water supply, in-land water protection, agriculture and nature conservation. In the present study, the spatial representativity of such a monitoring network in an area that has been thoroughly impacted by anthropogenic activity (river diversion/damming) is assessed, namely the Szigetköz adjacent to the River Danube. The main aims were to assess the spatial representativity of the SGW monitoring network in different discharge scenarios, and investigate the directional characteristics of this representativity, i.e. establish whether geostatistical anisotropy is present, and investigate how this changes with flooding. After the subtraction of a spatial trend from the time series of 85 shallow groundwater monitoring wells tracking flood events from 2006, 2009 and 2013, variography was conducted on the residuals, and the degree of anisotropy was assessed to explore the spatial autocorrelation structure of the network. Since the raw data proved to be insufficient, an interpolated grid was derived, and the final results were scaled to be representative of the original raw data. It was found that during floods the main direction of the spatial variance of the shallow groundwater monitoring wells alters, from perpendicular to the river to parallel with it for over a period of about two week. However, witht the passing of the flood, this returns to its original orientation in 2 months. It is likely that this process is related first to the fast removal of clogged riverbed strata by the flood, then to their slower replacement. In addition, the study highlights the importance of assessing the direction of the spatial autocorrelation structure of shallow groundwater monitoring networks, especially if the aim is to derive interpolated maps for the further investigation or modeling of flow.

  19. Uni- and multi-variable modelling of flood losses: experiences gained from the Secchia river inundation event.

    Science.gov (United States)

    Carisi, Francesca; Domeneghetti, Alessio; Kreibich, Heidi; Schröter, Kai; Castellarin, Attilio

    2017-04-01

    Flood risk is function of flood hazard and vulnerability, therefore its accurate assessment depends on a reliable quantification of both factors. The scientific literature proposes a number of objective and reliable methods for assessing flood hazard, yet it highlights a limited understanding of the fundamental damage processes. Loss modelling is associated with large uncertainty which is, among other factors, due to a lack of standard procedures; for instance, flood losses are often estimated based on damage models derived in completely different contexts (i.e. different countries or geographical regions) without checking its applicability, or by considering only one explanatory variable (i.e. typically water depth). We consider the Secchia river flood event of January 2014, when a sudden levee-breach caused the inundation of nearly 200 km2 in Northern Italy. In the aftermath of this event, local authorities collected flood loss data, together with additional information on affected private households and industrial activities (e.g. buildings surface and economic value, number of company's employees and others). Based on these data we implemented and compared a quadratic-regression damage function, with water depth as the only explanatory variable, and a multi-variable model that combines multiple regression trees and considers several explanatory variables (i.e. bagging decision trees). Our results show the importance of data collection revealing that (1) a simple quadratic regression damage function based on empirical data from the study area can be significantly more accurate than literature damage-models derived for a different context and (2) multi-variable modelling may outperform the uni-variable approach, yet it is more difficult to develop and apply due to a much higher demand of detailed data.

  20. Application of STORMTOOLS's simplified flood inundation model with sea level rise to assess impacts to RI coastal areas

    Science.gov (United States)

    Spaulding, M. L.

    2015-12-01

    The vision for STORMTOOLS is to provide access to a suite of coastal planning tools (numerical models et al), available as a web service, that allows wide spread accessibly and applicability at high resolution for user selected coastal areas of interest. The first product developed under this framework were flood inundation maps, with and without sea level rise, for varying return periods for RI coastal waters. The flood mapping methodology is based on using the water level vs return periods at a primary NOAA water level gauging station and then spatially scaling the values, based on the predictions of high resolution, storm and wave simulations performed by Army Corp of Engineers, North Atlantic Comprehensive Coastal Study (NACCS) for tropical and extratropical storms on an unstructured grid, to estimate inundation levels for varying return periods. The scaling for the RI application used Newport, RI water levels as the reference point. Predictions are provided for once in 25, 50, and 100 yr return periods (at the upper 95% confidence level), with sea level rises of 1, 2, 3, and 5 ft. Simulations have also been performed for historical hurricane events including 1938, Carol (1954), Bob (1991), and Sandy (2012) and nuisance flooding events with return periods of 1, 3, 5, and 10 yr. Access to the flooding maps is via a web based, map viewer that seamlessly covers all coastal waters of the state at one meter resolution. The GIS structure of the map viewer allows overlays of additional relevant data sets (roads and highways, wastewater treatment facilities, schools, hospitals, emergency evacuation routes, etc.) as desired by the user. The simplified flooding maps are publically available and are now being implemented for state and community resilience planning and vulnerability assessment activities in response to climate change impacts.

  1. Explanatory analysis of the relationship between atmospheric circulation and occurrence of flood generating events in a coastal city

    DEFF Research Database (Denmark)

    Åström, Helena Lisa Alexandra; Sunyer Pinya, Maria Antonia; Madsen, H.

    2016-01-01

    The aim of this study is to enhance the understanding of the occurrence of flood generating events in urban areas by analyzing the relationship between large-scale atmospheric circulation and extreme precipitation events, extreme sea water level events and their simultaneous occurrence......, respectively. To describe the atmospheric circulation we used the Lamb circulation type (LCT) classification and re-grouped it into Lamb circulation classes (LCC). The daily LCCs/LCTs were connected with rare precipitation and water level events in Aarhus, a Danish coastal city. Westerly and cyclonic LCCs (W......, C, SW, and NW) showed a significantly high occurrence of extreme precipitation. Similarly, for extreme water level events westerly LCCs (W and SW) showed a significantly high occurrence. Significantly low occurrence of extreme precipitation and water level events was obtained in easterly LCCs (NE, E...

  2. An attempt to estimate the economic value of the loss of human life due to landslide and flood events in Italy

    Science.gov (United States)

    Salvati, Paola; Bianchi, Cinzia; Hussin, Haydar; Guzzetti, Fausto

    2013-04-01

    Landslide and flood events in Italy cause wide and severe damage to buildings and infrastructure, and are frequently involved in the loss of human life. The cost estimates of past natural disasters generally refer to the amount of public money used for the restoration of the direct damage, and most commonly do not account for all disaster impacts. Other cost components, including indirect losses, are difficult to quantify and, among these, the cost of human lives. The value of specific human life can be identified with the value of a statistical life (VLS), defined as the value that an individual places on a marginal change in their likelihood of death This is different from the value of an actual life. Based on information of fatal car accidents in Italy, we evaluate the cost that society suffers for the loss of life due to landslide and flood events. Using a catalogue of fatal landslide and flood events, for which information about gender and age of the fatalities is known, we determine the cost that society suffers for the loss of their life. For the purpose, we calculate the economic value in terms of the total income that the working-age population involved in the fatal events would have earned over the course of their life. For the computation, we use the pro-capita income calculated as the ratio between the GDP and the population value in Italy for each year, since 1980. Problems occur for children and retired people that we decided not to include in our estimates.

  3. Hydrodynamic Based Decision Making Framework for Impact Assessment of Extreme Storm Events on Coastal Communities

    Science.gov (United States)

    Nazari, R.; Miller, K.; Hurler, C.

    2015-12-01

    Coastal and inland flooding has been a problematic occurrence, specifically over the past century. Global warming has caused an 8 inch sea level rise since 1990, which made the coastal flood zone wider, deeper and more damaging. Additionally, riverine flooding is extremely damaging to the country's substructure and economy as well which causes river banks to overflow, inundating low-lying areas. New Jersey and New York are two areas at severe risk for flood hazard, sea level rise, land depletion and economic loss which are the main study area of this work. A decision making framework is being built to help mitigate the impacts of the environmental and economical dangers of storm surges, sea level rise, flashfloods and inland flooding. With vigorous research and the use of innovative hydrologic modeling software, this tool can be built and utilized to form resiliency for coastal communities. This will allow the individuals living in a coastal community to understand the details of climatic hazards in their area and risks associated to their communities. This tool will also suggest the best solution for the problem each community faces. Atlantic City and New York City has been modeled and compared using potential storm events and the outcomes have been analyzed. The tool offers all the possible solutions for the type of flooding that occurs. Green infrastructure such as rain gardens, detention basins and green roofs can be used as small scale solutions. Greater scale solutions such as removable flood barriers, concrete walls and height adjustable walls will also be displayed if that poses as the best solution. The results and benefits from the simulation and modeling techniques, will allow coastal communities to choose the most appropriate method for building a long lasting and sustainable resilience plan in the future.

  4. Estimating the proportion of groundwater recharge from flood events in relation to total annual recharge in a karst aquifer

    Science.gov (United States)

    Dvory, N. Z.; Ronen, A.; Livshitz, Y.; Adar, E.; Kuznetsov, M.; Yakirevich, A.

    2017-12-01

    Sustainable groundwater production from karstic aquifers is primarily dictated by its recharge rate. Therefore, in order to limit over-exploitation, it is essential to accurately quantify groundwater recharge. Infiltration during erratic floods in karstic basins may contribute substantial amount to aquifer recharge. However, the complicated nature of karst systems, which are characterized in part by multiple springs, sinkholes, and losing/gaining streams, present a large obstacle to accurately assess the actual contribution of flood water to groundwater recharge. In this study, we aim to quantify the proportion of groundwater recharge during flood events in relation to the annual recharge for karst aquifers. The role of karst conduits on flash flood infiltration was examined during four flood and artificial runoff events in the Sorek creek near Jerusalem, Israel. The events were monitored in short time steps (four minutes). This high resolution analysis is essential to accurately estimating surface flow volumes, which are of particular importance in arid and semi-arid climate where ephemeral flows may provide a substantial contribution to the groundwater reservoirs. For the present investigation, we distinguished between direct infiltration, percolation through karst conduits and diffused infiltration, which is most affected by evapotranspiration. A water balance was then calculated for the 2014/15 hydrologic year using the Hydrologic Engineering Center - Hydrologic Modelling System (HEC-HMS). Simulations show that an additional 8% to 24% of the annual recharge volume is added from runoff losses along the creek that infiltrate through the karst system into the aquifer. The results improve the understanding of recharge processes and support the use of the proposed methodology for quantifying groundwater recharge.

  5. Predicting the flow in the floodplains with evolving land occupations during extreme flood events (FlowRes ANR project

    Directory of Open Access Journals (Sweden)

    Proust Sébastien

    2016-01-01

    Full Text Available Flood hazards (flow depth and velocity must be accurately assessed in high-risk areas during extreme flood events. However, the prediction of the very high flows is not an easy task due to the lack of field data and to the strong link between flow resistance and the land occupation of the floodplain. Confinement and inhomogeneity in lateral and longitudinal directions of hydraulic roughness strongly vary with return period T. The physical processes are complex, some still largely unexplored, and the assumptions linked to numerical modelling cannot be validated without field data. The FlowRes project (2015-2018, funded by the French National Research Agency (ANR, aims at improving the flood hazard assessment in floodplains in: 1 investigating in laboratory the hydrodynamic structure associated with extreme flood flows for various land occupations and flow discharge magnitudes; 2 assessing if the existing numerical modelling practices used for T ~ 100 years are still valid for extreme events with T > 1000 years, relying on the experimental data and on one field case. This paper reports some results obtained during the first year of the project.

  6. An operational procedure for rapid flood risk assessment in Europe

    Science.gov (United States)

    Dottori, Francesco; Kalas, Milan; Salamon, Peter; Bianchi, Alessandra; Alfieri, Lorenzo; Feyen, Luc

    2017-07-01

    The development of methods for rapid flood mapping and risk assessment is a key step to increase the usefulness of flood early warning systems and is crucial for effective emergency response and flood impact mitigation. Currently, flood early warning systems rarely include real-time components to assess potential impacts generated by forecasted flood events. To overcome this limitation, this study describes the benchmarking of an operational procedure for rapid flood risk assessment based on predictions issued by the European Flood Awareness System (EFAS). Daily streamflow forecasts produced for major European river networks are translated into event-based flood hazard maps using a large map catalogue derived from high-resolution hydrodynamic simulations. Flood hazard maps are then combined with exposure and vulnerability information, and the impacts of the forecasted flood events are evaluated in terms of flood-prone areas, economic damage and affected population, infrastructures and cities.An extensive testing of the operational procedure has been carried out by analysing the catastrophic floods of May 2014 in Bosnia-Herzegovina, Croatia and Serbia. The reliability of the flood mapping methodology is tested against satellite-based and report-based flood extent data, while modelled estimates of economic damage and affected population are compared against ground-based estimations. Finally, we evaluate the skill of risk estimates derived from EFAS flood forecasts with different lead times and combinations of probabilistic forecasts. Results highlight the potential of the real-time operational procedure in helping emergency response and management.

  7. The Environmental Impact of Flooding on Transportation Land Use ...

    African Journals Online (AJOL)

    Environmental problems of flooding on transportation land use manifest as a result of different land use activities of man to earn his living and his livelihood. Natural surfaces were replaced by more impermeable roads and concrete which have very low infiltration capacity, which have hydrological consequences of resulting ...

  8. Flood Impacts on Household's Welfare and Maximal Acceptable ...

    African Journals Online (AJOL)

    The number of people exposed year after year to natural disasters (lack of water, excess of water, strong winds, and earthquakes) is very high. Among natural hazards, those from extreme weather, especially floods, are more frequent and affect the greatest number of individuals. Generally in Benin, and particularly in the city ...

  9. Flooding Simulation of Extreme Event on Barnegat Bay by High-Resolution Two Dimensional Hydrodynamic Model

    Science.gov (United States)

    Wang, Y.; Ramaswamy, V.; Saleh, F.

    2017-12-01

    Barnegat Bay located on the east coast of New Jersey, United States and is separated from the Atlantic Ocean by the narrow Barnegat Peninsula which acts as a barrier island. The bay is fed by several rivers which empty through small estuaries along the inner shore. In terms of vulnerability from flooding, the Barnegat Peninsula is under the influence of both coastal storm surge and riverine flooding. Barnegat Bay was hit by Hurricane Sandy causing flood damages with extensive cross-island flow at many streets perpendicular to the shoreline. The objective of this work is to identify and quantify the sources of flooding using a two dimensional inland hydrodynamic model. The hydrodynamic model was forced by three observed coastal boundary conditions, and one hydrologic boundary condition from United States Geological Survey (USGS). The model reliability was evaluated with both FEMA spatial flooding extend and USGS High water marks. Simulated flooding extent showed good agreement with the reanalysis spatial inundation extents. Results offered important perspectives on the flow of the water into the bay, the velocity and the depth of the inundated areas. Using such information can enable emergency managers and decision makers identify evacuation and deploy flood defenses.

  10. Flood Deposition Analysis of Northern California's Eel River (Flood- DANCER)

    Science.gov (United States)

    Ahlgren, S.; Bauman, P. D.; Dillon, R. J.; Gallagher, N.; Jamison, M. E.; King, A.; Lee, J.; Siwicke, K. A.; Harris, C. K.; Wheatcroft, R. A.; Borgeld, J. C.; Goldthwait, S. A.

    2006-12-01

    Characterizing and quantifying the fate of river born sediment is critical to our understanding of sediment supply and erosion in impacted coastal areas. Strata deposited in coastal zones provide an invaluable record of recent and historical environmental events. The Eel River in northern California has one of the highest sediment yields of any North American river and has preserved evidence of the impact of recent flood events. Previous research has documented sediment deposits associated with Eel River flood events in January 1995, March 1995, and January 1997. These deposits were found north of the river mouth on the mid shelf in water depths from 50-100 m. Sediment strata were up to 5-10 cm thick and were composed of fine to very fine grained silts and clays. Until recently, no model had been able to correctly reproduce the sediment deposits associated with these floods. In 2005, Harris et al. developed a model that accurately represents the volume and location of the flood deposit associated with the January 1997 event. However, rigorous assessment of the predictive capability of this model requires that a new flood of the Eel River be used as a test case. During the winter of 2005-06 the Eel River rose above flood stage reaching discharge similar to the flood of January 1995 which resulted in flood sedimentation on the Eel River shelf. A flood-related deposit 1-5 cm thick was found in water depths of 60-90 m approximately 20-35 km north of the river mouth. Flood deposits were recognized in box cores collected in the months following the flood. As in previously studied events, flood- related strata near the sediment surface were recognized in core x-radiographs, resistivity and porosity profiles, and were composed of fine to very fine grained silts and clays. In addition, surface flood sediments were associated with lower concentrations of benthic foraminifera compared with deeper sediments. The January 2006 flood deposit was similar in thickness to the

  11. The significance of soil moisture in forecasting characteristics of flood events. A statistical analysis in two nested catchments

    Directory of Open Access Journals (Sweden)

    Chifflard Peter

    2018-03-01

    Full Text Available We examine the feasibility and added value of upscaling point data of soil moisture from a small- to a mesoscale catchment for the purpose of single-event flood prediction. We test the hypothesis that in a given catchment, the present soil moisture status is a key factor governing peak discharge, flow volume and flood duration. Multiple regression analyses of rainfall, pre-event discharge, single point soil moisture profiles from representative locations and peak discharge, discharge duration, discharge volume are discussed. The soil moisture profiles are selected along a convergent slope connected to the groundwater in flood plain within the small-scale catchment Husten (2.6 km², which is a headwater catchment of the larger Hüppcherhammer catchment (47.2 km², Germany. Results show that the number of explanatory variables in the regression models is higher in summer (up to 8 variables than in winter (up to 3 variables and higher in the meso-scale catchment than in the small-scale catchment (up to 2 variables. Soil moisture data from selected key locations in the small catchment improves the quality of regression models established for the meso-scale catchment. For the different target variables peak discharge, discharge duration and discharge volume the adding of the soil moisture from the flood plain and the lower slope as explanatory variable improves the quality of the regression model by 15%, 20% and 10%, respectively, especially during the summer season. In the winter season the improvement is smaller (up to 6% and the regression models mainly include rainfall characteristics as explanatory variables. The appearance of the soil moisture variables in the stepwise regression indicates their varying importance, depending on which characteristics of the discharge are focused on. Thus, we conclude that point data for soil moisture in functional landscape elements describe the catchments’ initial conditions very well and may yield valuable

  12. Numerical Modeling for Flood Mapping under Climate Change Impacts: Transboundary Dniester River Study

    Science.gov (United States)

    Zheleznyak, Mark; Kolomiets, Pavlo; Dzjuba, Natalia; Ievgen, Ievgen; Sorokin, Maxim; Denisov, Nickolai; Ischuk, Oleksiy; Koeppel, Sonja

    2015-04-01

    The Dniester river is shared by Ukraine and Moldova. Ukraine being both upstream and downstream of Moldova. The basin is especially suffering from heavy floods, often with transboundary impacts: in Ukraine, disastrous floods in July 2008, which were possibly partly caused or exacerbated by climate change. Within the UNECE | ENVSEC project "Reducing vulnerability to extreme floods and climate change in the Dniester river basin" the numerical flood risks mapping for several "hot spots" along the Dniester river was initiated Two transboundary sites: "Mohyliv Podylskiy- Ataki" and "Dubossary HPP-, Mayaki" (in the delta zone) were chosen for flood risk modelling/mapping. . Floodplain inundation at Mohyliv Podylskiy- Ataki during historical and projected extreme floods scenarios is simulated by 2D model COASTOX -UN based on the numerical solution of shallow water equations on unstructured grid. The scenario of extreme flood, July 2008 that caused hazardous flooding of the riverside areas of Mohyliv Podylskiy has been used for model verification and calibration. The floodmarks of the inundated in 2008 streets have been collected and GIS processed to be used together with the data from the city's water gage station for model testing. The comparison of the simulated dynamics of floodplain inundation during 2008 flood with the observed data show good accuracy of the model. The technologies of the flood modeling and GIS based risk assessments verified for this site are implemented for analyses of the vulnerability to extreme floods for Q=7600 m3 / sec inflow to Dniester reservoir ( 1% flood for contemporary climate assessment) and for Q=8700 m3 / sec. that is considered as projection of 1% flood maximum for XXI century The detailed flood mapping was provided for all cases and was shown that 13% increase in water elevation for future extreme flood scenario will provide at 20% increasing of flooded areas in Mohilev Podolsky. For the site Dubossary NPP in Moldova downstream till

  13. Coastal Flood Risks in the Bangkok Metropolitan Region, Thailand: Combined Impacts of Land Subsidence, Sea Level Rise and Storm Surge

    Science.gov (United States)

    Duangyiwa, C.; Yu, D.; Wilby, R.; Aobpaet, A.

    2015-12-01

    Due to the fast-changing climatic and anthropogenic conditions at coastal regions, many coastal mega-cities are becoming increasingly vulnerable to internal and external risks. The risk is particularly high for low-lying coastal cities in developing nations, with Southeast Asia recognized as a hotspot of vulnerability due to the increasing population density, rapid change of natural landscape associated with urbanization and intensified hydrological and atmospheric conditions at the coastal front in an uncertain climate future. The Bangkok Metropolitan Region is one of the largest coastal megacities in Southeast Asia that are challenged by the potential impacts due to climate change and anthropological variability in the coming decades. Climate-related risks in this region are associated with its relatively low-lying nature of the terrain and adjacency to the coast. Coastal inundation due to high tides from the sea occurs annually in the area close to the seashore. This is set to increase given a projected rising sea level and the sinking landscape due to groundwater extraction and urbanization. The aim of this research is, therefore, to evaluate the vulnerability of the city to sea level rise, land subsidence and storm surge. Distributed land subsidence rate, projected sea level rise and existing structural features such as flood defences are taken into account. The 2011 flood in Thailand is used as a baseline event. Scenarios were designed with projections of land subsidence and sea level rise to 2050s, 2080s, and 2100s. A two-dimensional flood inundation model (FloodMap, Yu and Lane 2006) is used to derive inundation depth and velocity associated with each scenario. The impacts of coastal flood risk on critical infrastructures (e.g. power supply, transportation network, rescue centers, hospitals, schools and key government buildings) are evaluated (e.g. Figure 1). Results suggest progressively increase but non-linear risks of coastal flooding to key coastal

  14. Flood Summary Report, Nooksack, Skagit and Snohomish River Basins November 1990 Events

    Science.gov (United States)

    1991-07-18

    opeations); and p-ovidIno technical. advise and assistance. All flood team members performed exceptionally, with outstand.i,c results. Whatcom County...sack EOC at 1345 and set up base, including phones. maps and admin office. Paul Johnson arrived at 1430 and left for emergency meetinq with Whatcom ...County at the county shop. Wayne Kutch arrived at 1435 and left for Everson to inspect flooding. Phoned Dan Fitzgerald at Whatcom County EOC at 1440 and

  15. 75 FR 58369 - Intent To Prepare a Draft Environmental Impact Statement for the North Branch Ecorse Creek, Flood...

    Science.gov (United States)

    2010-09-24

    ... Draft EIS will address potential environmental impacts of the construction, operation, and maintenance... Environmental Impact Statement for the North Branch Ecorse Creek, Flood Risk Management General Reevaluation... Notice of Intent (NOI) to prepare a Draft Environmental Impact Statement (EIS) for flood risk management...

  16. Stage discharge curve for Guillemard Bridge streamflow sation based on rating curve method using historical flood event data

    International Nuclear Information System (INIS)

    Ros, F C; Sidek, L M; Desa, M N; Arifin, K; Tosaka, H

    2013-01-01

    The purpose of the stage-discharge curves varies from water quality study, flood modelling study, can be used to project climate change scenarios and so on. As the bed of the river often changes due to the annual monsoon seasons that sometimes cause by massive floods, the capacity of the river will changed causing shifting controlled to happen. This study proposes to use the historical flood event data from 1960 to 2009 in calculating the stage-discharge curve of Guillemard Bridge located in Sg. Kelantan. Regression analysis was done to check the quality of the data and examine the correlation between the two variables, Q and H. The mean values of the two variables then were adopted to find the value of difference between zero gauge height and the level of zero flow, 'a', K and 'n' to fit into rating curve equation and finally plotting the stage-discharge rating curve. Regression analysis of the historical flood data indicate that 91 percent of the original uncertainty has been explained by the analysis with the standard error of 0.085.

  17. Climate change impacts and uncertainties in flood risk management: Examples from the North Sea Region

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, D.; Graham, L.P.; Besten, J. Den; Andreasson, J.; Bergstroem, S.; Engen-Skaugen, T.; Foerland, E.; Groen, R.; Jespersen, M.; Jong, K. de; Olsson, J.

    2012-07-01

    This report presents methods used for estimating the hydrological impacts of climate change and their uncertainties, the expected impacts on extreme flows in Norway, and in Sweden with particular reference to Lake Vaenern, and examples of climate change impacts on river discharge and on agriculture in the Netherlands. Work considering changes in extreme precipitation is also reported, as are methods and strategies for communicating climate change impacts in flood management practice. (eb)

  18. Coastal flooding impact evaluation using an INtegrated DisRuption Assessment (INDRA) model for Varna region, Western Black Sea

    Science.gov (United States)

    Andreeva, Nataliya; Eftimova, Petya; Valchev, Nikolay; Prodanov, Bogdan

    2017-04-01

    The study presents evaluation and comparative analysis of storm induced flooding impacts on different coastal receptors at a scale of Varna region using INtegrated DisRuption Assessment (INDRA) model. The model was developed within the FP7 RISC-KIT project, as a part of Coastal Risk Assessment Framework (CRAF) consisting of two phases. CRAF Phase 1 is a screening process that evaluates coastal risk at a regional scale by means of coastal indices approach, which helps to identify potentially vulnerable coastal sectors: hot spots (HS). CRAF Phase 2 has the objective to assess and rank identified hotspots by detailed risk analysis done by jointly performing a hazard assessment and an impact evaluation on different categories (population, businesses, ecosystems, transport and utilities) using INDRA model at a regional level. Basically, the model assess the shock of events by estimating the impact on directly exposed to flooding hazard receptors of different vulnerability, as well as the potential ripple effects during an event in order to assess the "indirect" impacts, which occur outside the hazard area and/or continue after the event for all considered categories. The potential impacts are expressed in terms of uniform "Impact Indicators", which independently score the indirect impacts of these categories assessing disruption and recovery of the receptors. The ultimate hotspot ranking is obtained through the use of a Multi Criteria analysis (MCA) incorporated in the model, considering preferences of stakeholders. The case study area - Varna regional coast - is located on the western Black Sea, Bulgaria. The coastline, with a length of about 70 km, stretches from cape Ekrene to cape St. Atanas and includes Varna Bay. After application of CRAF Phase 1 three hotspots were selected for further analysis: Kabakum beach (HS1), Varna Central beach plus Port wall (HS2) and Artificial Island (HS3). For first two hotspots beaches and associated infrastructure are the assets

  19. Delivering Integrated Flood Risk Management: Governance for collaboration, learning and adaptation

    NARCIS (Netherlands)

    Van Herk, S.

    2014-01-01

    The frequency and consequences of extreme flood events have increased rapidly worldwide in recent decades and climate change and economic growth are likely to exacerbate this trend. Flood protection measures alone cannot accommodate the future frequencies and impacts of flooding. Integrated flood

  20. Delivering Integrated Flood Risk Management : Governance for collaboration, learning and adaptation

    NARCIS (Netherlands)

    Van Herk, S.

    2014-01-01

    The frequency and consequences of extreme flood events have increased rapidly worldwide in recent decades and climate change and economic growth are likely to exacerbate this trend. Flood protection measures alone cannot accommodate the future frequencies and impacts of flooding. Integrated flood

  1. The environmental impacts of beach sport tourism events: a case ...

    African Journals Online (AJOL)

    Durban has several established beach sport events. One of the many events is the Mr Price Pro, an internationally recognised surfi ng event, which takes place during the Vodacom Beach Africa festival, held annually during the July holiday season. This article examines the environmental impact of beach tourism events by ...

  2. Assessing the Impact of Seasonal Population Fluctuation on Regional Flood Risk Management

    Directory of Open Access Journals (Sweden)

    Alan Smith

    2015-07-01

    Full Text Available Human populations are not static or uniformly distributed across space and time. This consideration has a notable impact on natural hazard analyses which seek to determine population exposure and risk. This paper focuses on the coupling of population and environmental models to address the effect of seasonally varying populations on exposure to flood risk. A spatiotemporal population modelling tool, SurfaceBuilder247, has been combined with LISFLOOD-FP flood inundation model outputs for a study area centred on the coastal resort town of St Austell, Cornwall, United Kingdom (UK. Results indicate strong seasonal cycles in populations and their exposure to flood hazard which are not accounted for in traditional population datasets and flood hazard assessments. Therefore, this paper identifies and demonstrates considerable enhancements to the current handling of spatiotemporal population variation within hazard exposure assessment and disaster risk management.

  3. The impact of floods in hospital and mitigation measures: A literature review

    Science.gov (United States)

    Yusoff, N. A.; Shafii, H.; Omar, R.

    2017-11-01

    In late December 2014, the flood was most significant and largest recorded specifically in the Kelantan, Malaysia. It was considered to be a “tsunami like disaster” in which 202,000 victims were displaced and causing widespread collapse of public infrastructure. Flooding of hospital results in interruption of business, loss of infrastructure, such as electrical power and water supplies, increased difficulty in providing routine medical and increased patient admissions and nursing care for patients with chronic diseases, such as renal failure, diabetes, cancer, cystic fibrosis and mental illness. The aimed of this paper to identify the best of measures for reduce the risk of flood in hospital. Method of this paper uses the previous study result. Several related previous study can be used as measures to mitigation flood risk in Malaysian hospitals. Early stage research of related studies hope to help add more information to assist researchers in reducing the risk of flooding in hospital. The findings with proper pre-event preparation framework for mitigation flood risk of hospitals, the continuing medical services can be provided to patient especially during emergency.

  4. A new geophone device for understanding environmental impacts caused by gravel bedload during artificial floods

    Science.gov (United States)

    Tsubaki, Ryota; Kawahara, Yoshihisa; Zhang, Xin-Hua; Tsuboshita, Kentaro

    2017-02-01

    To assess the contribution of gravel bedload on the removal of attached-algae and aquatic plants from a cobble-bed river during small floods, we propose a geophone type method for measuring the local bedload of non-uniform sized gravel. Due to limited peak discharge for focused events during our study, a large fraction of bed material (here cobbles) was immobile and only a small fraction of bed material (sand and gravel) was expected to be transported during the flushing flows we analyzed. The device we developed has a size equivalent to immobile bed material and a shape similar to bed material (rounded cobbles) at the site. The instrument's design allows avoidance of disturbances in river bed micro-topography during installation and local bedload transport during floods. A flume experiment was conducted in order to establish an empirical algorithm for estimating the diameter of impacted gravel, and uncertainty related to diameter estimation is discussed. The proposed method was utilized to quantify gravel bedload in a cobble-bed river during flushing flows. We also discuss the contribution of measured gravel bedload during flushing flows on the removal of attached-algae (up to a 37% reduction in chlorophyll-a density) and aquatic plants (a reduction of 38% in dry mass per area). Based on time variation for the measured gravel bedload, we also suggest the propagation of a bed-form composed of the fine sediment fraction migrating on immobile larger sediment and implications for the propagation of the fine sediment wave for attached-algae removal.

  5. The Impact of Climate Change on the Duration and Division of Flood Season in the Fenhe River Basin, China

    Directory of Open Access Journals (Sweden)

    Hejia Wang

    2016-03-01

    Full Text Available This study analyzes the duration and division of the flood season in the Fenhe River Basin over the period of 1957–2014 based on daily precipitation data collected from 14 meteorological stations. The Mann–Kendall detection, the multiscale moving t-test, and the Fisher optimal partition methods are used to evaluate the impact of climate change on flood season duration and division. The results show that the duration of the flood season has extended in 1975–2014 compared to that in 1957–1974. Specifically, the onset date of the flood season has advanced 15 days, whereas the retreat date of the flood season remains almost the same. The flood season of the Fenhe River Basin can be divided into three stages, and the variations in the onset and retreat dates of each stage are also examined. Corresponding measures are also proposed to better utilize the flood resources to adapt to the flood season variations.

  6. Concentration-discharge relationships during an extreme event: Contrasting behavior of solutes and changes to chemical quality of dissolved organic material in the Boulder Creek Watershed during the September 2013 flood: SOLUTE FLUX IN A FLOOD EVENT

    Energy Technology Data Exchange (ETDEWEB)

    Rue, Garrett P. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Rock, Nathan D. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Gabor, Rachel S. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Pitlick, John [Department of Geography, University of Colorado, Boulder Colorado USA; Tfaily, Malak [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; McKnight, Diane M. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA

    2017-07-01

    During the week of September 10-17, 2013, close to 20 inches of rain fell across Boulder County, Colorado, USA. This rainfall represented a 1000-year event that caused massive hillslope erosion, landslides, and mobilization of sediments. The resultant stream flows corresponded to a 100-year flood. For the Boulder Creek Critical Zone Observatory (BC-CZO), this event provided an opportunity to study the effect of extreme rainfall on solute concentration-discharge relationships and biogeochemical catchment processes. We observed base cation and dissolved organic carbon (DOC) concentrations at two sites on Boulder Creek following the recession of peak flow. We also isolated three distinct fractions of dissolved organic matter (DOM) for chemical characterization. At the upper site, which represented the forested mountain catchment, the concentrations of the base cations Ca, Mg and Na were greatest at the peak flood and decreased only slightly, in contrast with DOC and K concentrations, which decreased substantially. At the lower site within urban corridor, all solutes decreased abruptly after the first week of flow recession, with base cation concentrations stabilizing while DOC and K continued to decrease. Additionally, we found significant spatiotemporal trends in the chemical quality of organic matter exported during the flood recession, as measured by fluorescence, 13C-NMR spectroscopy, and FTICR-MS. Similar to the effect of extreme rainfall events in driving landslides and mobilizing sediments, our findings suggest that such events mobilize solutes by the flushing of the deeper layers of the critical zone, and that this flushing regulates terrestrial-aquatic biogeochemical linkages during the flow recession.

  7. Studies of images of short-lived events using ERTS data. [forest fires, oil spills, vegetation damage, volcanoes, storm ridges, earthquakes, and floods

    Science.gov (United States)

    Deutschman, W. A. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Detection of short-lived events has continued. Forest fires, oil spills, vegetation damage, volcanoes, storm ridges, earthquakes, and floods have been detected and analyzed.

  8. August, 2002 - floods events, affected areas revitalisation and prevention for the future in the central Bohemian region, Czech Republic

    Science.gov (United States)

    Bina, L.; Vacha, F.; Vodova, J.

    2003-04-01

    Central Bohemian Region is located in a shape of a ring surrounding the capitol of Prague. Its total territorial area is 11.014 sq.km and population of 1 130.000 inhabitants. According to EU nomenclature of regional statistical units, the Central Bohemian Region is classified as an independent NUTS II. Bohemia's biggest rivers, Vltava and Labe form the region's backbone dividing it along a north-south line, besides that there are Sazava and Berounka, the two big headwaters of Vltava, which flow through the region and there also are some cascade man made lakes and 2 important big dams - Orlik and Slapy on the Vltava River in the area of the region. Overflowing of these rivers and their feeders including cracking of high-water dams during the floods in August 2002 caused total or partial destruction or damage of more than 200 towns and villages and total losses to the extend of 450 mil. EUR. The worst impact was on damaged or destroyed human dwellings, social infrastructure (schools, kindergartens, humanitarian facilities) and technical infrastructure (roads, waterworks, power distribution). Also businesses were considerably damaged including transport terminals in the area of river ports. Flowage of Spolana Neratovice chemical works caused critical environmental havoc. Regional crisis staff with regional Governor in the lead worked continuously during the floods and a regional integrated rescue system was subordinated to it. Due to the huge extent of the floods the crisis staff coordinated its work with central bodies of state including the Government and single "power" resorts (army, interior, transport). Immediately after floods a regional - controlled management was set up including an executive body for regional revitalisation which is connected to state coordinating resort - Ministry for Local Development, EU sources and humanitarian aid. In addition to a program of regional revitalisation additional preventive flood control programs are being developed

  9. Impacts of climate change on rainfall, seasonal flooding, and evapotranspiration in the Okavango Delta, Botswana

    Science.gov (United States)

    Konecky, B. L.; Noone, D.; Mosimanyana, E.; Gondwe, M.

    2016-12-01

    The Okavango Delta in northern Botswana is one of the world's richest biodiversity hotspots. A UNESCO World Heritage Site, the Delta is known for its unique annual flood pulse, whereby the wetland and its neighboring river systems are inundated with waters that travel nearly 1000 km before reaching this subtropical, semi-arid destination. The livelihoods of northern Botswana's ecosystems and human populations rely on these floods to supplement the short and variable rainy season, which in many years is too minimal to ameliorate regional drought. However, anthropogenic climate change is reducing the amount of water that reaches the delta by increasing evaporation from soils and rivers, and transpiration by vegetation, during its long transit to Botswana. Future changes in rainfall patterns, extreme events, and increased upstream water use could exacerbate this water stress. Unfortunately, it remains difficult to assess the impacts of climate change on the delta because few data exist to constrain its complex climatic and seasonal water cycling regimes. This study presents a novel characterization of the water cycle in and around the Okavango Delta based on a survey of free-flowing surface waters, stagnant pools, precipitation, and groundwater carried out during the 2016 rainy and early-flood season. We use stable isotope and water quality data to assess local moisture sources, transport, evaporation, wetland flushing, and land-atmosphere exchanges, all of which are subject to change under global warming. We find a strong evaporation gradient and a progressive flushing of stagnant swamp waters along the northeastern and northwestern channels of the Delta. The evaporation gradient is more limited in nearby rivers with more limited wetlands. We contrast results with a survey of the Delta performed in the 1970's in order to assess changes over the past 40 years. Since some of these changes may arise from rainfall supply, we also present new analysis of rainfall moisture

  10. Estimating regional long-term economic consequences of natural hazards - a case study of the 2005 flood event in Tyrol (Austria)

    Science.gov (United States)

    Pfurtscheller, C.; Lochner, B.; Brucker, A.

    2012-04-01

    The interaction of relief-driven alpine natural processes with the anthropogenic sphere often leads to natural disasters which significantly impact on remote alpine economies. When evaluating the effects of such events for future risk prevention strategies, it is essential to assess indirect losses. While the economic measurement of direct effects - the physical impact on structures and infrastructure - seems fairly manageable, less is known about the dimensions of indirect effects, especially on a local and regional scale within the Alps. The lack of standardized terminology, empirical data and methods to estimate indirect economic effects currently hampers profound decision support. In our study of the 2005 flood event in Tyrol, we surveyed companies from all sectors of the economy to identify the main drivers of indirect effects and interrupted economic flows. In collaboration with the Federal State administration, we extrapolate the total regional economic effects of this catastrophic event. Using quantitative and qualitative methods, we established and analysed a data pool of questionnaire and interview results as well as direct loss data. We mainly focus on the decrease in value creation and the negative impacts on tourism. We observed that disrupted traffic networks can have a highly negative impact, especially for the tourism sector in lateral alpine valleys. Within a month, turnover fell by approximately EUR 3.3 million in the investigated area. In the short run (until August 2006), the shortfall in touristic revenues in the Paznaun valley aggregated to approx. EUR 5.3 million. We observed that overnight stays rebound very quickly so that long-term effects are marginal. In addition, we tried to identify possible economical losers as well as winners of severe hazard impacts. In response to such flood events, high investments are made to improve disaster and risk management. Nearly 70% of the respondents specified the (re)construction sector and similar

  11. Characterizing the impacts of water resources infrastructure, humans, and hydrologic nonstationarity on changes in flood risk across the Himalaya region

    Science.gov (United States)

    Tullos, D. D.

    2014-12-01

    As flood control infrastructure reaches its design life, and climate change, population growth, and urban migration increase flood risk, the historical paradigm of store-then-release floodwaters behind rigid infrastructure is of decreasing physical and socioeconomic value. Instead, a new paradigm of sustainable flood management is emerging, which can be framed in the context of three elements that can contribute to and/or mitigate flood risk: 1) water resources infrastructure, 2) policies and socioeconomics, and 3) changing climates and land use. In this presentation, I present the results of analysis on the role of these three elements in contributing to flood risk of the Sutlej River (India) and the Koshi River (Nepal) basins for six historical flood events. The Himalaya region was selected based on the a) increasing intensity of monsoonal rains, b) increasing prevalence of glacial lake outburst floods, c) water resources management that achieves short-term development goals but lacks long-term sustainability, and d) other socio-economic, environmental, and geopolitical factors. I develop and apply a flood risk management framework that is based on metrics for characterizing the losses associated with the three elements contributing to major floods in the Himalaya region. Derived from a variety of data sources, results highlight how, across different hydrogeologic settings and various flood magnitudes, the largest influences on high flood losses are associated with inflexible water resources infrastructure and inappropriate development and flood management policies. Particularly for the most destructive events, which are generally associated with landslides and other natural hazards in this region, the effectiveness of some types of traditional and inflexible flood management infrastructure, including large dams and levees, is limited. As opposed to the probability of a particular flood event, findings illustrate the importance of the damages side of the flood

  12. Social vulnerability analysis of the event flood puddle (case study in Lamongan regency, East Java province)

    Science.gov (United States)

    Soegiyanto; Rindawati

    2018-01-01

    This research was conducted in the flood plain Bonorowo in Lamongan East Java Province. The area was inundated almost every year, but people still survive and remain settled at the sites. This research is to identify and analyze the social vulnerability in the flood plains on the characteristics puddle Bonorowo This research method is the study of the characteristics and livelihood strategies of the communities living on marginal lands (floodplains Bonorowo) are regions prone to flooding / inundation. Based on the object of this study is a survey research method mix / mix method, which merge or combination of methods of quantitative and qualitative methods, so it will be obtained a description of a more comprehensive and holistic. The results obtained in this study are; Social vulnerability is not affected by the heightened puddles. Social capital is abundant making society safer and more comfortable to keep their activities and settle in the region

  13. A comparison of the flood precipitation episode in August 2002 with historic extreme precipitation events on the Czech territory

    Czech Academy of Sciences Publication Activity Database

    Řezáčová, Daniela; Kašpar, Marek; Müller, Miloslav; Sokol, Zbyněk; Kakos, Vilibald; Hanslian, David; Pešice, Petr

    2005-01-01

    Roč. 77, - (2005), s. 354-366 ISSN 0169-8095 R&D Projects: GA AV ČR(CZ) IBS3042101; GA MŽP(CZ) SA/650/4/03 Institutional research plan: CEZ:AV0Z30420517 Keywords : Precipitation * Summer floods * Czech territory * Hydro-meteorological conditions * Extremeness of meteorological quantities * Distribution function Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.481, year: 2005

  14. The Use of Chemoprophylaxis after Floods to Reduce the Occurrence and Impact of Leptospirosis Outbreaks.

    Science.gov (United States)

    Schneider, Maria Cristina; Velasco-Hernandez, Jorge; Min, Kyung-Duk; Leonel, Deise Galan; Baca-Carrasco, David; Gompper, Matthew E; Hartskeerl, Rudy; Munoz-Zanzi, Claudia

    2017-06-03

    Record-breaking and devastating rainfall events have occurred in the past decade. Rain and floods are considered the main risk factors for leptospirosis and several outbreaks have been reported following extreme weather events. In such situations, one possible intervention to prevent leptospirosis cases in high-risk groups is the use of chemoprophylaxis. However, not enough evidence of its effect is available. The objectives of this study were to review the literature on the current practices of chemoprophylaxis for leptospirosis and to explore, using a mathematical model, how various chemoprophylaxis scenarios may affect the progression of a leptospirosis outbreak. Twenty-six peer-reviewed publications were selected (10 quantitative studies, two systematic reviews and 14 articles of other types). Oral doxycycline was the most used antibiotic for chemoprophylaxis of leptospirosis. Post-exposure prophylaxis was assessed in four studies following a natural disaster. Although evidence of the effectiveness of post-exposure prophylaxis is inconsistent, the direction of association supported a protective effect for morbidity and mortality. The theoretical model showed how the assumed benefit of chemoprophylaxis was influenced by the time and rate of administration. Future models should consider the heterogeneity of affected communities, improved estimates of the effect of chemoprophylaxis on leptospirosis infection and disease, as well as potential detrimental impacts. Additional research is critical to provide clear evidence-based recommendations for leptospirosis control during an outbreak. The results of this study suggest that chemoprophylaxis may provide some protection in reducing the number of leptospirosis cases after a high-risk exposure; however, the effective benefit may depend on a variety of factors such as the timing and coverage of prophylaxis. The information summarized can be used to support decision-making during a high-risk event.

  15. The Use of Chemoprophylaxis after Floods to Reduce the Occurrence and Impact of Leptospirosis Outbreaks

    Directory of Open Access Journals (Sweden)

    Maria Cristina Schneider

    2017-06-01

    Full Text Available Record-breaking and devastating rainfall events have occurred in the past decade. Rain and floods are considered the main risk factors for leptospirosis and several outbreaks have been reported following extreme weather events. In such situations, one possible intervention to prevent leptospirosis cases in high-risk groups is the use of chemoprophylaxis. However, not enough evidence of its effect is available. The objectives of this study were to review the literature on the current practices of chemoprophylaxis for leptospirosis and to explore, using a mathematical model, how various chemoprophylaxis scenarios may affect the progression of a leptospirosis outbreak. Twenty-six peer-reviewed publications were selected (10 quantitative studies, two systematic reviews and 14 articles of other types. Oral doxycycline was the most used antibiotic for chemoprophylaxis of leptospirosis. Post-exposure prophylaxis was assessed in four studies following a natural disaster. Although evidence of the effectiveness of post-exposure prophylaxis is inconsistent, the direction of association supported a protective effect for morbidity and mortality. The theoretical model showed how the assumed benefit of chemoprophylaxis was influenced by the time and rate of administration. Future models should consider the heterogeneity of affected communities, improved estimates of the effect of chemoprophylaxis on leptospirosis infection and disease, as well as potential detrimental impacts. Additional research is critical to provide clear evidence-based recommendations for leptospirosis control during an outbreak. The results of this study suggest that chemoprophylaxis may provide some protection in reducing the number of leptospirosis cases after a high-risk exposure; however, the effective benefit may depend on a variety of factors such as the timing and coverage of prophylaxis. The information summarized can be used to support decision-making during a high-risk event.

  16. Patterns and comparisons of human-induced changes in river flood impacts in cities

    Science.gov (United States)

    Clark, Stephanie; Sharma, Ashish; Sisson, Scott A.

    2018-03-01

    In this study, information extracted from the first global urban fluvial flood risk data set (Aqueduct) is investigated and visualized to explore current and projected city-level flood impacts driven by urbanization and climate change. We use a novel adaption of the self-organizing map (SOM) method, an artificial neural network proficient at clustering, pattern extraction, and visualization of large, multi-dimensional data sets. Prevalent patterns of current relationships and anticipated changes over time in the nonlinearly-related environmental and social variables are presented, relating urban river flood impacts to socioeconomic development and changing hydrologic conditions. Comparisons are provided between 98 individual cities. Output visualizations compare baseline and changing trends of city-specific exposures of population and property to river flooding, revealing relationships between the cities based on their relative map placements. Cities experiencing high (or low) baseline flood impacts on population and/or property that are expected to improve (or worsen), as a result of anticipated climate change and development, are identified and compared. This paper condenses and conveys large amounts of information through visual communication to accelerate the understanding of relationships between local urban conditions and global processes.

  17. Combined Effect of an Atmospheric River and a Cut-off Low in Hiroshima Flooding Event on August 19, 2014

    Science.gov (United States)

    Takayabu, Y. N.; Hirota, N.; Kato, M.; Arakane, S.

    2015-12-01

    An extraordinary precipitation over 100 mmhr-1in Hiroshima on August 19, 2014, caused a flash flood which resulted in 74 fatalities and collapse of 330 houses. In order to examine the meteorological background of this flooding event, we carried out a detailed analysis utilizing rain gauge data, satellite precipitation dataset, and a meso scale and a global scale objective analyses provided from the Japan Meteorological Agency. Then, we performed numerical experiments using a nonhydrostatic compressible equation model called the Cloud-Resolving Storm Simulator (CReSS). As a result, a combined effect of an atmospheric river (AR) and a cut-off low (COL) in this flooding event was elucidated. During the event, a filamentary transport of moisture extending from the Indochina Peninsula to the Japanese Islands was observed along the southern side of the subtropical jet, forming an AR. This AR had a deep structure with an amount of free tropospheric moisture comparable to that of the boundary layer. Concurrently, there was a COL, detached from the Mid-Pacific Trough, moving northwestward toward the Japanese Archipelago. With various sensitivity experiments, we concluded that a mid-tropospheric instability associated with the cold core of the COL and a dynamical ascent induced in its foreside, collaboratively worked with the anomalous moisture in the free troposphere associated with the AR, to extraordinarily enhance the precipitation over Hiroshima region. An orographic effect to concentrate the precipitation in this region was also confirmed. An implication on a difference in effects of AR in this event with a climatologically moist boundary layer, from those in the US west coast with a very dry environment, was also obtained. Acknowledgment: This study is supported by the Environment Research and Technology Development Fund (2-1503) of the Ministry of the Environment, Japan, and by the Ministry of Education, Culture, Sports, Science and Technology, Japan.

  18. Evaluation of low impact development approach for mitigating flood inundation at a watershed scale in China.

    Science.gov (United States)

    Hu, Maochuan; Sayama, Takahiro; Zhang, Xingqi; Tanaka, Kenji; Takara, Kaoru; Yang, Hong

    2017-05-15

    Low impact development (LID) has attracted growing attention as an important approach for urban flood mitigation. Most studies evaluating LID performance for mitigating floods focus on the changes of peak flow and runoff volume. This paper assessed the performance of LID practices for mitigating flood inundation hazards as retrofitting technologies in an urbanized watershed in Nanjing, China. The findings indicate that LID practices are effective for flood inundation mitigation at the watershed scale, and especially for reducing inundated areas with a high flood hazard risk. Various scenarios of LID implementation levels can reduce total inundated areas by 2%-17% and areas with a high flood hazard level by 6%-80%. Permeable pavement shows better performance than rainwater harvesting against mitigating urban waterlogging. The most efficient scenario is combined rainwater harvesting on rooftops with a cistern capacity of 78.5 mm and permeable pavement installed on 75% of non-busy roads and other impervious surfaces. Inundation modeling is an effective approach to obtaining the information necessary to guide decision-making for designing LID practices at watershed scales. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. IMPACTS OF WETLAND DEGRADATION IN NIGER DELTA NIGERIA AND ITS SIGNIFICANCE IN FLOOD CONTROL

    Directory of Open Access Journals (Sweden)

    Enwere Chidimma Loveline

    2015-08-01

    Full Text Available  Wetlands perform a wide variety of functions that include flood control, ground water recharge, shore line stabilization, storm protection and climate moderation. However, despite these huge wetland functions, it has witnessed poor appreciation and dreadful conditions. Niger Delta has witnessed constant coastal erosion and rising sea level, this has led to large portions of the landmass being eroded. This paper aims to review some environmental effects of flooding in the Niger Delta region of Nigeria to provide the desired knowledge of role that wetlands play in reducing flood impacts. However, having witnessed the flood, the experience opened my eyes to the environmental challenges facing Niger Delta with respect to Wetlands degradation, poor perception of wetland values and functions, poor environmental practices and non-implementation of environmental regulations. This memorable experience rekindled the desire and motivation to seek a solution to wetland degradation with the aim of recognizing significance of wetlands at the centre of achieving both livelihood and biodiversity improvements to address coastal flooding problem.The study therefore concludes that wetlands are very significant in flood control and thus the conservation and restoration of wetlands, should put in place measures to reduce wetland destruction.International Journal of EnvironmentVolume-4, Issue-3, June-August 2015Page: 177-184

  20. Can we predict the next urban flood?

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Nielsen, Jesper Ellerbæk; Jensen, David Getreuer

    2015-01-01

    Flooding produced by high-intensive local rainfall and drainage system capacity exceedance can have severe impacts in cities. In order to prepare cities for these types of flood events – especially in the future climate – it is valuable to be able to simulate these events numericallyboth...... historically and in real-time. There is a rather untested potential in real-time prediction of urban floods. In this paper radar data observations with different spatial and temporal resolution, radar nowcasts of 0-2 hours leadtime, and numerical weather models with leadtimes up to 24 h are used as inputs...... to an integrated flood and drainage systems model with the purpose to investigate the potential for predicting future floods. The system is tested on a small town Lystrup in Denmark, which has been recently flooded. Results show that it is possible to generate detailed flood maps in real-time with high resolution...

  1. Flood impact assessment on the development of Archaia Olympia riparian area in Greece.

    Science.gov (United States)

    Pasaporti, Christina; Podimata, Marianthi; Yannopoulos, Panayotis

    2013-04-01

    A long list of articles in the literature examines several issues of flood risk management and applications of flood scenarios, taking into consideration the climate changes, as well as decision making tools in flood planning. The present study tries to highlight the conversation concerning flood impacts on the development rate of a riparian area. More specifically, Archaia (Ancient) Olympia watershed was selected as a case study area, since it is considered as a region of special interest and international significance. In addition, Alfeios River, which is the longest river of Peloponnisos Peninsula, passes through the plain of Archaia Olympia. Flood risk scenarios allow scientists and practitioners to understand the adverse effects of flooding on development activities such as farming, tourism etc. and infrastructures in the area such as road and railway networks, Flokas dam and the hydroelectric power plant, bridges, settlements and other properties. Flood risks cause adverse consequences on the region of Archaia Olympia (Ancient Olympic stadium) and Natura 2000 site area. Furthermore, SWOT analysis was used in order to quantify multicriteria and socio-economic characteristics of the study area. SWOT analysis, as a planning method, indicates the development perspective by identifying the strengths, weaknesses, threads and opportunities. Subsequent steps in the process of intergraded River Management Plan of Archaia Olympia could be derived from SWOT analysis. The recognition and analysis of hydro-geomorphological influences on riparian development activities can lead to the definition of hazardous and vulnerability zones and special warning equipment. The former information combined with the use of the spatial database for the catchment area of the River Alfeios, which aims to gather multiple watershed data, could serve in preparing the Management Plan of River Basin District 01 where Alfeios R. belongs. Greece has to fulfill the obligation of implementing River

  2. Impacts of the 2013 Extreme Flood in Northeast China on Regional Groundwater Depth and Quality

    Directory of Open Access Journals (Sweden)

    Xihua Wang

    2015-08-01

    Full Text Available Flooding’s impact on shallow groundwater is not well investigated. In this study, we analyzed changes in the depth and quality of a regional shallow aquifer in the 10.9 × 104 km2 Sanjiang Plain, Northeast China, following a large flood in the summer of 2013. Pre- (2008–2012 and post-flood records on groundwater table depth and groundwater chemistry were gathered from 20 wells across the region. Spatial variability of groundwater recharge after the flood was assessed and the changes in groundwater quality in the post-flood period were determined. The study found a considerable increase in the groundwater table after the 2013 summer flood across the region, with the largest (3.20 m and fastest (0.80 m·s−1 rising height occurring in western Sanjiang Plain. The rising height and velocity gradually declined from the west to the east of the plain. For the entire region, we estimated an average recharge height of 1.24 m for the four flood months (June to September of 2013. Furthermore, we found that the extreme flood reduced nitrate (NO3− and chloride (Cl− concentrations and electrical conductivity (EC in shallow groundwater in the areas that were close to rivers, but increased NO3− and Cl− concentrations and EC in the areas that were under intensive agricultural practices. As the region’s groundwater storage and quality have been declining due to the rapidly increasing rice cultivation, this study shows that floods should be managed as water resources to ease the local water shortage as well as shallow groundwater pollution.

  3. Comparative Analysis on Effects of Low Impact Development Techniques on Urban Flooding Considering Regional and Geographical Characteristics

    Science.gov (United States)

    Park, J.; Lee, D. K.; Yang, B.

    2016-12-01

    Low impact development(LID) is generally known as a more sustainable solution for urban stormwater management than traditional urban drainage systems. Since the emergence of LID, they have been successfully used to manage stormwater runoff, improve water quality, and protect the environment. However, its effects on urban drainage systems have not been fully understood particularly when regional and geographical characteristics are considered.In this paper, using 3 different urbanized catchments considering regional and geographical characteristics (slope, elevation, impervious cover etc.) in Korea, the effects were compared by the difference among the characteristics. The effects of LID techniques on urban flooding are analyzed by using EPA SWMM-5 and selected the suitable LID techniques for each characteristic. The effects are measured by the total flood volume reduction and peak flow time delay during a storm event compared to the traditional drainage system design.By comparing the result of each LID technique, the results indicate the suitable LID techniques considering each different regional and geographical characteristic. This paper provides an insight into the performance of LID designs under regional and geographical characteristics, which is essential for effective urban flood management.

  4. Impacts of channel deposition on the risk of flooding in a watershed

    Science.gov (United States)

    Ting-Yue, Hong; Chia-Ling, Chang

    2017-04-01

    Taiwan is located in East Asian where is always hit by typhoons. Typhoons usually bring huge amounts of rainfall and result in the problems of channel deposition. Deposition influences the functions of channel and increases the risk of flooding. The Luliao Reservoir Watershed is the case area in this study. It is the major water source for agricultural activity and domestic use. The objective of this study is to assess the possible impacts of channel deposition on the watershed environment. This study applies the Storm Water Management Model (SWMM) to predict the hydrologic responses and evaluate the risk of flooding. The results show that the decrease of cross section induced by deposition in a channel may increase the risk of flooding and impact the safety of watershed environment. Therefore, canal desilting is important in channel regulation. The discussion and analysis can be useful references for channel regulation.

  5. Health risks during and after high flood events and hygienic consequences

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, A.; Pitten, F.A.; Rudolph, P.; Below, H. [Greifswald Univ. (Germany). Inst. of Hygiene and Environmental Medicine

    2001-07-01

    The dominating health risk is undoubtly the endangering through pathogenes in the drinking water. Secondary health risks are given after the flood in dependence on climatic regions because the evolution circumstances for insects are good. If these can be vectors for pathogenes a special observation is needed. (orig.)

  6. Climate Change Impacts on Flood risk in Urban Areas due to Combined Effects of Extreme Precipitation and Sea Surges

    DEFF Research Database (Denmark)

    Larsen, A. N.; Mikkelsen, Peter Steen; Arnbjerg-Nielsen, Karsten

    Climate change will impact the hydrological cycle greatly and lead to increases in flood hazards due to both pluvial and fluvial floods as well as sea surges in many regions. The impacts of the individual effects are analysed for a catchment in Greater Copenhagen. Based on both the present...

  7. Impacts of floods on forest trees and their coping strategies in Bangladesh

    Directory of Open Access Journals (Sweden)

    Shukla Rani Basak

    2015-03-01

    Full Text Available During recent years, the Government of Bangladesh, Non-Government Organizations (NGOs, semi-government organizations, private organizations and individuals have established a large number of plantations under different programs viz. social forestry, agro-forestry and avenue plantations with indigenous and exotic tree species without considering their habit and habitats. Along with the indigenous species like Albizia procera, Albizia lebbeck, Mangifera indica, Azadirachta indica, Gmelina arborea, Trewia nudiflora and Artocapus heterophyllus and many exotic species e.g. Swietenia macrophylla, Albizia saman, Dalbergia sissoo, Eucalyptus camaldulensis, Acacia auriculiformis, Melia sempervirens, Acacia mangium etc. have been planted randomly. With increasing trend of climate-induced floods, millions of trees have been dying due to floods and water-logging. The most affected species are Dalbergia sissoo, Albizia saman, Acacia auriculiformis, Acacia mangium and Artocarpus heterophyllus etc. This situation has caused severe impacts on socio-economic conditions of Bangladesh. The impacts involved a significant loss in terms of investment, biodiversity and afforestation program. Little investigations have been conducted to find out the causes of the deaths and also to find out the suitable adaptation practices to reduce impacts of floods on trees. This synthesis focused on the impacts of floods on plantations and also assessed the potential role of traditional forest management practices in addressing the effects flooding on forests in Bangladesh. The study added important information and revealed knowledge gaps on the causes of large forest deaths. It also provided recommendations for policy on the establishment of frequent floods resilient tree crop plantations.

  8. Resilience in the built environment: How to evaluate the impacts of flood resilient building technologies?

    Directory of Open Access Journals (Sweden)

    Golz Sebastian

    2016-01-01

    Full Text Available The EU floods directive and its transcription into national legislation request exposed citizens and organisations to take individual measures to reduce flood risks on building scale. In response to that issue, a number of general approaches to buildings in flood risk areas and a set of strategies and technical guidance for the design and construction of flood resilient buildings have been developed in recent years. Particularly flood resilient building materials and constructions (FReMaCo, e.g. adapted exterior wall systems or floor arrangements, are expected to provide a considerable potential to limit flood damage if, for example, aperture technologies cannot stop water entering the building. However, there are significant uncertainties about the performance of FReMaCo that impede their comparison and hamper their uptake. To reduce those obstacles the paper discusses the application of the analytic hierarchy process (AHP (i to quantify and to compare the physical flood vulnerability of various building constructions and (ii to evaluate and to rank the impact of alternative FReMaCo options. The paper explores a set of eleven evaluation criteria ranging from statics criteria about buildings physics criteria up to durability criteria. The AHP generates a weight for each defined criterion and assigns a score for each FReMaCo option. Then, the AHP combines the criteria weights and the option scores to determine a global score for each construction alternative that evaluate the impact of FReMaCo options in a comprehensible manner. The application of AHP reduces the bias in the decision making process and is therefore of international interest, especially for those involved in improving the resilience properties of buildings.

  9. Beyond retrospective assessment. Sport event economic impact studies as a management tool for informing event organization

    Directory of Open Access Journals (Sweden)

    Angel Barajas

    2016-09-01

    Full Text Available Sport event promoters aim to organize them to get the best return on their investment. The purpose of this study is to learn better how to manage the event to maximize the benefit to the host area. Most studies on economic impact of sporting events focus on mega events or look for an impact in medium to large size cities. This study estimates the effect of a two-day event, the Rally Ourense, that takes place in a small town in Spain. Economic impact is estimated based on surveys of spectators and interviews of competitors in the 2009, 2010, and 2011 editions of the rally. The results show that the race has favorable effects, but also suggest that the impact could be increased with some simple changes to the event structure.

  10. When nature frowns: A comprehensive impact assessment of the 2012 Babessi floods on people’s livelihoods in rural Cameroon

    Directory of Open Access Journals (Sweden)

    Roland A. Balgah

    2015-11-01

    Full Text Available Floods are the most common natural disasters worldwide. Much of the growing literature on the impact of floods, especially in developed countries, and to a lesser extent in rural areas of developing countries, concentrates on economic rather than a comprehensive assessment of combined effects on people’s livelihoods. Holistic floods impact assessments are often done long after the shock, raising problems of data reliability following long recall periods, although post-disaster needs assessments when carried out earlier can facilitate appropriate disaster recovery, relief and reconstruction activities. We applied the sustainable livelihoods framework as a comprehensive approach to assess the impacts of the Babessi floods in 2012 on livelihoods in rural (north western region of Cameroon 6 weeks after the floods. Using a structured questionnaire, data was collected from victims before and after the floods, using recall methods. A matched sample of nonvictims randomly selected from the same village as the victims was used to assess vulnerability to the floods by household type. Floods were found to have serious economic, social, human and food security impacts on victims. Both government and nongovernmental support were jointly crucial for household recovery. Comparatively observed high levels of recovery were attributed to the low loss of human lives. The article concludes with the need for comprehensive approaches to floods impact assessments. The need for combining formal and informal instruments in post-disaster management in rural areas is also emphasised.

  11. Flood in a Changing Climate: The Impact on Livelihood and How the Rural Poor Cope in Bangladesh

    Directory of Open Access Journals (Sweden)

    Gulsan Ara Parvin

    2016-12-01

    Full Text Available It is already documented that climate change will lead to an intensification of the global water cycle with a consequent increase in flood hazards. Bangladesh is also facing an increasing trend of flood disasters. Among the various risks and disasters in Bangladesh, flood is the most common and frequent. Floods make people vulnerable, as they take away their livelihoods at the first instance and leave them with little resources to overcome from the situation. Because of floods, rural poor communities face job loss, and two-thirds of their income is reduced, which limits their capabilities of preparedness, response, and recovery to subsequent floods. People cope with the situation by bearing substantial debts and a loss of productive assets. With an empirical field study in one of the most flood-prone upazilas (sub-districts of Bangladesh, namely Goalanda Upazilla of the Rajbari district, this study intends to draw a “flood impact tree” of the study area. It also examines the impacts of flood on the livelihood of the rural poor and explores their coping strategies. This paper aims to facilitate an understanding of the impact of floods on their livelihood, especially on the income and occupations of the rural poor. At the same time, it aims to learn from their coping mechanisms.

  12. Impacts of 21st century sea-level rise on a Danish major city - an assessment based on fine-resolution digital topography and a new flooding algorithm

    International Nuclear Information System (INIS)

    Moeslund, Jesper Erenskjold; Svenning, Jens-Christian; Boecher, Peder Klith; Moelhave, Thomas; Arge, Lars

    2009-01-01

    This study examines the potential impact of 21st century sea-level rise on Aarhus, the second largest city in Denmark, emphasizing the economic risk to the city's real estate. Furthermore, it assesses which possible adaptation measures that can be taken to prevent flooding in areas particularly at risk from flooding. We combine a new national Digital Elevation Model in very fine resolution (∼2 meter), a new highly computationally efficient flooding algorithm that accurately models the influence of barriers, and geospatial data on real-estate values to assess the economic real-estate risk posed by future sea-level rise to Aarhus. Under the A2 and A1FI (IPCC) climate scenarios we show that relatively large residential areas in the northern part of the city as well as areas around the river running through the city are likely to become flooded in the event of extreme, but realistic weather events. In addition, most of the large Aarhus harbour would also risk flooding. As much of the area at risk represent high-value real estate, it seems clear that proactive measures other than simple abandonment should be taken in order to avoid heavy economic losses. Among the different possibilities for dealing with an increased sea level, the strategic placement of flood-gates at key potential water-inflow routes and the construction or elevation of existing dikes seems to be the most convenient, most socially acceptable, and maybe also the cheapest solution. Finally, we suggest that high-detail flooding models similar to those produced in this study will become an important tool for a climate-change-integrated planning of future city development as well as for the development of evacuation plans.

  13. Impacts of 21st century sea-level rise on a Danish major city - an assessment based on fine-resolution digital topography and a new flooding algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Moeslund, Jesper Erenskjold; Svenning, Jens-Christian [Ecoinformatics and Biodiversity Group, Department of Biological Sciences, Aarhus University (Denmark); Boecher, Peder Klith [Department of Agroecology and Environment, Aarhus University (Denmark); Moelhave, Thomas; Arge, Lars, E-mail: jesper.moeslund@biology.au.d [MADALGO - Center for Massive Data Algorithmics, Aarhus University (Denmark)

    2009-11-01

    This study examines the potential impact of 21st century sea-level rise on Aarhus, the second largest city in Denmark, emphasizing the economic risk to the city's real estate. Furthermore, it assesses which possible adaptation measures that can be taken to prevent flooding in areas particularly at risk from flooding. We combine a new national Digital Elevation Model in very fine resolution ({approx}2 meter), a new highly computationally efficient flooding algorithm that accurately models the influence of barriers, and geospatial data on real-estate values to assess the economic real-estate risk posed by future sea-level rise to Aarhus. Under the A2 and A1FI (IPCC) climate scenarios we show that relatively large residential areas in the northern part of the city as well as areas around the river running through the city are likely to become flooded in the event of extreme, but realistic weather events. In addition, most of the large Aarhus harbour would also risk flooding. As much of the area at risk represent high-value real estate, it seems clear that proactive measures other than simple abandonment should be taken in order to avoid heavy economic losses. Among the different possibilities for dealing with an increased sea level, the strategic placement of flood-gates at key potential water-inflow routes and the construction or elevation of existing dikes seems to be the most convenient, most socially acceptable, and maybe also the cheapest solution. Finally, we suggest that high-detail flooding models similar to those produced in this study will become an important tool for a climate-change-integrated planning of future city development as well as for the development of evacuation plans.

  14. Impact of climate change on river flooding assessed with different spatial model resolutions

    NARCIS (Netherlands)

    Booij, Martijn J.

    2005-01-01

    The impact of climate change on flooding in the river Meuse is assessed on a daily basis using spatially and temporally changed climate patterns and a hydrological model with three different spatial resolutions. This is achieved by selecting a hydrological modelling framework and implementing

  15. The impact of river flooding and high flow on the demersal fish ...

    African Journals Online (AJOL)

    Freshwater inflow has a strong impact on the biological, chemical and physical characteristics of estuaries, which in turn affect the distribution and abundance of estuarine organisms. Increased climatic variability associated with climate change is predicated to modify precipitation patterns, which will likely intensify floods in ...

  16. Immediate impact of the flood (Bohemia, August 2002) on selected soil characteristics

    Czech Academy of Sciences Publication Activity Database

    Elhottová, Dana; Krištůfek, Václav; Tříska, Jan; Chrastný, V.; Uhlířová, Eva; Kalčík, Jiří; Picek, T.

    2006-01-01

    Roč. 173, č. 1-4, (2006), s. 177-193 ISSN 0049-6979 Institutional research plan: CEZ:AV0Z6066911; CEZ:AV0Z6087904; CEZ:AV0Z60870520 Keywords : flood on soil * hazardous elements * organic persistent compounds Subject RIV: EH - Ecology, Behaviour Impact factor: 1.205, year: 2006

  17. Development of a standardised methodology for event impact ...

    African Journals Online (AJOL)

    The Western Cape Government (WCG) developed an Integrated Events Strategy for Cape Town and the Western Cape, supporting events to maximise brand building potential and triple bottom line benefits. WCG acknowledges that assessing the impacts of events in the province has become increasingly complex and ...

  18. Using Bayesian Network as a tool for coastal storm flood impact prediction at Varna Bay (Bulgaria, Western Black Sea)

    Science.gov (United States)

    Valchev, Nikolay; Eftimova, Petya; Andreeva, Nataliya; Prodanov, Bogdan

    2017-04-01

    Coastal zone is among the fastest evolving areas worldwide. Ever increasing population inhabiting coastal settlements develops often conflicting economic and societal activities. The existing imbalance between the expansion of these activities, on one hand, and the potential to accommodate them in a sustainable manner, on the other, becomes a critical problem. Concurrently, coasts are affected by various hydro-meteorological phenomena such as storm surges, heavy seas, strong winds and flash floods, which intensities and occurrence frequency is likely to increase due to the climate change. This implies elaboration of tools capable of quick prediction of impact of those phenomena on the coast and providing solutions in terms of disaster risk reduction measures. One such tool is Bayesian network. Proposed paper describes the set-up of such network for Varna Bay (Bulgaria, Western Black Sea). It relates near-shore storm conditions to their onshore flood potential and ultimately to relevant impact as relative damage on coastal and manmade environment. Methodology for set-up and training of the Bayesian network was developed within RISC-KIT project (Resilience-Increasing Strategies for Coasts - toolKIT). Proposed BN reflects the interaction between boundary conditions, receptors, hazard, and consequences. Storm boundary conditions - maximum significant wave height and peak surge level, were determined on the basis of their historical and projected occurrence. The only hazard considered in this study is flooding characterized by maximum inundation depth. BN was trained with synthetic events created by combining estimated boundary conditions. Flood impact was modeled with the process-based morphodynamical model XBeach. Restaurants, sport and leisure facilities, administrative buildings, and car parks were introduced in the network as receptors. Consequences (impact) are estimated in terms of relative damage caused by given inundation depth. National depth

  19. Assessing impacts of dike construction on the flood dynamics of the Mekong Delta

    Science.gov (United States)

    Tran, Dung Duc; van Halsema, Gerardo; Hellegers, Petra J. G. J.; Phi Hoang, Long; Quang Tran, Tho; Kummu, Matti; Ludwig, Fulco

    2018-03-01

    Recent flood dynamics of the Mekong Delta have raised concerns about an increased flood risk downstream in the Vietnamese Mekong Delta. Accelerated high dike building on the floodplains of the upper delta to allow triple cropping of rice has been linked to higher river water levels in the downstream city of Can Tho. This paper assesses the hydraulic impacts of upstream dike construction on the flood hazard downstream in the Vietnamese Mekong Delta. We combined the existing one-dimensional (1-D) Mekong Delta hydrodynamic model with a quasi-two-dimensional (2-D) approach. First we calibrated and validated the model using flood data from 2011 and 2013. We then applied the model to explore the downstream water dynamics under various scenarios of high dike construction in An Giang Province and the Long Xuyen Quadrangle. Calculations of water balances allowed us to trace the propagation and distribution of flood volumes over the delta under the different scenarios. Model results indicate that extensive construction of high dikes on the upstream floodplains has had limited effect on peak river water levels downstream in Can Tho. Instead, the model shows that the impacts of dike construction, in terms of peak river water levels, are concentrated and amplified in the upstream reaches of the delta. According to our water balance analysis, river water levels in Can Tho have remained relatively stable, as greater volumes of floodwater have been diverted away from the Long Xuyen Quadrangle than the retention volume lost due to dike construction. Our findings expand on previous work on the impacts of water control infrastructure on flood risk and floodwater regimes across the delta.

  20. Turbidites as proxy for past flood events: Testing this approach in a large clastic system (Lake Geneva, France/Switzerland)

    Science.gov (United States)

    Kremer, Katrina; Girardclos, Stéphanie

    2017-04-01

    Turbidites recorded in lake sediments are often used to reconstruct the frequency of past flood and also seismological events. However, for such a reconstruction, the origin and causes of the recorded turbidites need to be clearly identified. In this study, we test if turbidites can be used as paleohydrological archive based on the the sedimentary record of Lake Geneva resulting from inputs by the Rhone and Dranse clastic river systems. Our approach is based on several methods combining high-resolution seismic reflection data with geophysical (magnetic susceptibility, grain size) and high-resolution XRF/XRD data measured on ca. 10-m-long sediment cores (dated by radiocarbon ages and 137Cs activity). This dataset allows distinguishing between the different sources (rivers or hemipelagic sediment) of the turbidites deposited in the deep basin of Lake Geneva. However, no clear distinction between the various trigger processes (mass failures or floods) could be made, thus flood deposits could not be clearly identified. From our results, we also conclude that the lack of turbidite deposits in the deep basin between the 15th and 18th century seems to be linked to a change in turbidite depocentre due to the Rhone River mouth shifting possibly triggered by human activity and not by any direct climate effect. This study demonstrates that a least two conditions are needed to perform an adequate paleohydrological interpretation based on turbidite records: (1) the holistic understanding of the basin sedimentary system and (2) the distinction of flood-induced turbidites from other types of turbidites (mass failures etc.).

  1. When does higher spatial resolution rainfall information improve streamflow simulation? An evaluation on 3620 flood events

    Science.gov (United States)

    Lobligeois, F.; Andréassian, V.; Perrin, C.; Tabary, P.; Loumagne, C.

    2013-10-01

    Precipitation is the key factor controlling the high-frequency hydrological response in catchments, and streamflow simulation is thus dependent on the way rainfall is represented in the hydrological model. A characteristic that distinguishes distributed from lumped models is the ability to explicitly represent the spatial variability of precipitation. Although the literature on this topic is abundant, the results are contrasted and sometimes contradictory. This paper investigates the impact of spatial rainfall on runoff generation to better understand the conditions where higher-resolution rainfall information improves streamflow simulations. In this study, we used the rainfall reanalysis developed by Météo-France over the whole French territory at 1 km and 1 h resolution over a 10 yr period. A hydrological model was applied in the lumped mode (a single spatial unit) and in the semi-distributed mode using three unit sizes of sub-catchments. The model was evaluated against observed streamflow data using split-sample tests on a large set of 181 French catchments representing a variety of size and climate conditions. The results were analyzed by catchment classes and types of rainfall events based on the spatial variability of precipitation. The evaluation clearly showed different behaviors. The lumped model performed as well as the semi-distributed model in western France where catchments are under oceanic climate conditions with quite spatially uniform precipitation fields. In contrast, higher resolution in precipitation inputs significantly improved the simulated streamflow dynamics and accuracy in southern France (Cévennes and Mediterranean regions) for catchments in which precipitation fields were identified to be highly variable in space. In all regions, natural variability allows for contradictory examples to be found, showing that analyzing a large number of events over varied catchments is warranted.

  2. When does higher spatial resolution rainfall information improve streamflow simulation? An evaluation using 3620 flood events

    Science.gov (United States)

    Lobligeois, F.; Andréassian, V.; Perrin, C.; Tabary, P.; Loumagne, C.

    2014-02-01

    Precipitation is the key factor controlling the high-frequency hydrological response in catchments, and streamflow simulation is thus dependent on the way rainfall is represented in a hydrological model. A characteristic that distinguishes distributed from lumped models is the ability to explicitly represent the spatial variability of precipitation. Although the literature on this topic is abundant, the results are contrasting and sometimes contradictory. This paper investigates the impact of spatial rainfall on runoff generation to better understand the conditions where higher-resolution rainfall information improves streamflow simulations. In this study, we used the rainfall reanalysis developed by Météo-France over the whole country of France at 1 km and 1 h resolution over a 10 yr period. A hydrological model was applied in the lumped mode (a single spatial unit) and in the semidistributed mode using three unit sizes of subcatchments. The model was evaluated against observed streamflow data using split-sample tests on a large set of French catchments (181) representing a variety of sizes and climate conditions. The results were analyzed by catchment classes and types of rainfall events based on the spatial variability of precipitation. The evaluation clearly showed different behaviors. The lumped model performed as well as the semidistributed model in western France, where catchments are under oceanic climate conditions with quite spatially uniform precipitation fields. By contrast, higher resolution in precipitation inputs significantly improved the simulated streamflow dynamics and accuracy in southern France (Cévennes and Mediterranean regions) for catchments in which precipitation fields were identified to be highly variable in space. In all regions, natural variability allows for contradictory examples to be found, showing that analyzing a large number of events over varied catchments is warranted.

  3. Biological Processes Associated with Impact Events

    Science.gov (United States)

    Cockell, Charles; Koeberl, Christian; Gilmour, Iain

    The diversity of papers presented in this volume attest to the fact that impact cratering is very much a biological process. This volume is the tenth in a series of books resulting from the activities of the scientific programme, "Response of the Earth System to Impact Processes" (IMPACT), by the European Science Foundation. The papers were presented at an international meeting at King's College, Cambridge in 2003. These papers investigate the effects of asteroid and comet impacts on a diversity of biological and evolutionary processes including the survival of organics and microbial ecosystems to the extinction of organisms.

  4. Impact of the Three-Gorges Dam and water transfer project on Changjiang floods

    Science.gov (United States)

    Nakayama, Tadanobu; Shankman, David

    2013-01-01

    Increasing frequency of severe floods on the middle and lower Changjiang (Yangtze) River during the past few decades can be attributed to both abnormal monsoon rainfall and landscape changes that include extensive deforestation affecting river sedimentation, and shrinking lakes and levee construction that reduced the areas available for floodwater storage. The Three-Gorges Dam (TGD) and the South-to-North Water Transfer Project (SNWTP) will also affect frequency and intensity of severe floods in the Poyang Lake region of the middle Changjiang. Process-based National Integrated Catchment-based Eco-hydrology (NICE) model predicts that the TGD will increase flood risk during the early summer monsoon against the original justifications for building the dam, relating to complex river-lake-groundwater interactions. Several scenarios predict that morphological change will increase flood risk around the lake. This indicates the importance of managing both flood discharge and sediment deposition for the entire basin. Further, the authors assessed the impact of sand mining in the lake after its prohibition on the Changjiang, and clarified that alternative scenario of sand mining in lakes currently disconnected from the mainstream would reduce the flood risk to a greater extent than intensive dredging along junction channel. Because dry biomasses simulated by the model were linearly related to the Time-Integrated Normalized Difference Vegetation Index (TINDVI) estimated from satellite images, its decadal gradient during 1982-1999 showed a spatially heterogeneous distribution and generally decreasing trends beside the lakes, indicating that the increases in lake reclamation and the resultant decrease in rice productivity are closely related to the hydrologic changes. This integrated approach could help to minimize flood damage and promote better decisions addressing sustainable development.

  5. Flooding and low oxygen responses in plants

    NARCIS (Netherlands)

    Pedersen, Ole; Perata, Pierdomenico; Voesenek, Laurentius A.C.J.

    2017-01-01

    The world is currently experiencing dramatic increases in flood events impacting on natural vegetation and crops. Flooding often results in low O2 status in root tissues during waterlogging, but sometimes also in shoot tissues when plants become completely submerged. Plants possess a suite of traits

  6. Impact of wet season river flood discharge on phytoplankton absorption properties in the southern Great Barrier Reef region coastal waters

    Science.gov (United States)

    Cherukuru, Nagur; Brando, Vittorio E.; Blondeau-Patissier, David; Ford, Phillip W.; Clementson, Lesley A.; Robson, Barbara J.

    2017-09-01

    Light absorption due to particulate and dissolved material plays an important role in controlling the underwater light environment and the above water reflectance signature. Thorough understanding of absorption properties and their variability is important to estimate light propagation in the water column. However, knowledge of light absorption properties in flood impacted coastal waters is limited. To address this knowledge gap we investigated a bio-optical dataset collected during a flood (2008) in the southern Great Barrier Reef (GBR) region coastal waters. Results presented here show strong impact of river flood discharges on water column stratification, distribution of suspended substances and light absorption properties in the study area. Bio-optical analysis showed phytoplankton absorption efficiency to reduce in response to increased coloured dissolved organic matter presence in flood impacted coastal waters. Biogeophysical property ranges, relationships and parametrisation presented here will help model realistic underwater light environment and optical signature in flood impacted coastal waters.

  7. Toward a space-time scale framework for the study of everyday life activity's adaptation to hazardous hydro-meteorological conditions: Learning from the June 15th, 2010 flash flood event in Draguignan (France)

    Science.gov (United States)

    Ruin, Isabelle; Boudevillain, Brice; Creutin, Jean-Dominique; Lutoff, Céline

    2013-04-01

    Western Mediterranean regions are favorable locations for heavy precipitating events. In recent years, many of them resulted in destructive flash floods with extended damage and loss of life: Nîmes 1988, Vaison-la-Romaine 1992, Aude 1999 and Gard 2002 and 2005. Because of the suddenness in the rise of water levels and the limited forecasting predictability, flash floods often surprise people in the midst of their daily activity and force them to react in a very limited amount of time. In such fast evolving events impacts depend not just on such compositional variables as the magnitude of the flood event and the vulnerability of those affected, but also on such contextual factors as its location and timing (night, rush hours, working hours...). Those contextual factors can alter the scale and social distribution of impacts and vulnerability to them. In the case of flooding fatalities, for instance, the elderly are often said to be the most vulnerable, but when fatalities are mapped against basin size and response time, it has been shown that in fact it is young adults who are most likely to be killed in flash flooding of small catchments, whereas the elderly are the most frequent victim of large scale fluvial flooding. Further investigations in the Gard region have shown that such tendency could be explained by a difference of attitude across ages with respect to mobility related to daily life routine and constraints. According to a survey of intentional behavior professionals appear to be less prone to adapting their daily activities and mobility to rapidly changing environmental conditions than non-professionals. Nevertheless, even if this appears as a tendency in both the analysis of limited data on death circumstances and intended behavior surveys, behavioral verification is very much needed. Understanding how many and why people decide to travel in hazardous weather conditions and how they adapt (or not) their activities and schedule in response to

  8. Impact of Aluminum on Anticipated Corrosion in a Flooded spent nuclear fuel Multi -Canister Overpack

    International Nuclear Information System (INIS)

    DUNCAN, D.R.

    1999-01-01

    Corrosion reactions in a flooded MCO are examined to determine the impact of aluminum corrosion products (from aluminum basket grids and spacers) on bound water estimates and subsequent fuel/environment reactions during storage. The mass and impact of corrosion products were determined to be insignificant, validating the choice of aluminum as an MCO component and confirming expectations that no changes to the Technical Databook or particulate mass or water content are necessary

  9. Impact of Aluminum on Anticipated Corrosion in a Flooded SNF Multi Canister Overpack (MCO)

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN, D.R.

    1999-07-06

    Corrosion reactions in a flooded MCO are examined to determine the impact of aluminum corrosion products (from aluminum basket grids and spacers) on bound water estimates and subsequent fuel/environment reactions during storage. The mass and impact of corrosion products were determined to be insignificant, validating the choice of aluminum as an MCO component and confirming expectations that no changes to the Technical Databook or particulate mass or water content are necessary.

  10. Impacts of urban development and climate change in exposing cities to pluvial flooding

    DEFF Research Database (Denmark)

    Kaspersen, Per Skougaard

    Urban areas are characterized by very high concentrations of people and economic activities and are thus particularly vulnerable to flooding dur ing extreme precipitation. Urban development and climate change are among the key drivers of changes in the exposure of cities to the occurrence...... precipitation. Climate change is expected to affect the intensity and frequency of extreme precipitation, with increases projected for many regions, including most parts of Europe....... and impacts of pluvial flooding. Cities are often dominated by large areas of impervious surfaces, that is, man-made sealed surfaces which water cannot penetrate, and increases in these – for example, as a consequence of urban development – can cause elevated run-off volumes and flood levels during...

  11. Impact of seismic events on containment and consequence analysis

    International Nuclear Information System (INIS)

    Lutz, R.J. Jr.; Holmes, B.G.; Vavrek, K.J.

    1985-01-01

    A level 3 probabilistic risk assessment study includes analysis of the plant response to initiating events, analysis of the containment response to degraded core events, fission product source term analysis and consequence analysis. The analysis of the plant response to initiating events must consider both events which occur within the plant systems which challenge the plant safety system (internal initiating events) and events which occur external to the plant systems (external initiating events). The Millstone Unit 3 Probabilistic Safety Study considered the containment and consequence analyses for the dominant event sequences defined in the plant analysis with separate treatment of internal initiating events and external initiating events. The results, as detailed herein, indicate that separate consideration of external initiating events, particularly seismic initiating events, have a significant impact on the containment and consequence analyses for both internal and external initiating events. By treating seismic events separately, more realistic models and assumptions could be used for the internal initiating events analysis as opposed to the bounding approach. The result is directly translated to the risk estimates, including uncertainty for both internal and external initiating events

  12. Impact of dams on flood occurrence of selected rivers in the United States

    Science.gov (United States)

    Mei, Xuefei; Van Gelder, P. H. A. J. M.; Dai, Zhijun; Tang, Zhenghong

    2016-10-01

    A significant large number of dams have been constructed in the past two centuries in the United States. These dams' ability to regulate downstream flooding has received world-wide attention. In this study, data from 38 rivers distributed over the entire conterminous Untied States with extensive pre- and post-dam annual peak discharge records, were collected to research the impacts of various dams on the flood behaviors at a national scale. The results indicate that dams have led to significant reductions in flood magnitude for nearly all of the sites; the decrease rate in the mean of annual peak discharge varies between 7.4% and 95.14%, except for the Dead River, which increased by 1.46%. Because of dams' effectiveness, the probability density curve of annual peak flow changes from a flat to peaked shape because both the range and magnitude of high discharges are decreased. Moreover, the potential impact of dams on flood characteristics were closely related to the dam's geographic location and function, the ratio of the storage capacity of the dam to the mean annual runoff of the river (C/R), and the ratio of reservoir storage capacity to the area of its drainage (C/D). Specifically, the effects of dams on annual peak flows were more related to latitude than longitude. Compared with dams built for other purposes, the dam exclusively used for flood management cut off more flood peaks. Increases in the ratios of C/R and C/D increased the degree of modification of annual maximum discharge.

  13. Predicting impact of SLR on coastal flooding in Banda Aceh coastal defences

    Science.gov (United States)

    Al'ala, Musa; Syamsidik, Kato, Shigeru

    2017-10-01

    Banda Aceh is a low-lying city located at the northern tip of Sumatra Island and situated at the conjuncture of Malacca Strait and the Andaman Sea. A Sea Level Rise (SLR) rate at 7 mm/year has been observed around this region. In the next 50 years, this city will face a serious challenge to encounter impacts of the sea level rise, such as frequent coastal floodings. This study is aimed at estimating impacts of the sea level rise induced coastal floodings on several types of coastal structures and city drainage system. Numerical simulations of Delft3D were applied to investigate the influence of the gradual sea level rise in 50 years. The hydrodynamic process of coastal flooding and sediment transport were simulated by Delft3D-Flow. Topography and bathymetry data were collected from GEBCO and updated with the available nautical chart (DISHIDROS, JICA, and field measurements). Hydrodynamic process gains the flow process revealing the level of the sea water intrusion also observed in the model. Main rivers (Krueng Aceh, Krueng Neng, and Alue Naga Flood Canal) and the drainage system were observed to see the tides effects on coastal structures and drainage system. The impact on coastal community focusing on affected area, shoreline retreat, the rate of sea intrusion was analyzed with spatial tools. New coastal line, coastal flooding vulnerable area, and the community susceptibility properties map influenced by 50 years sea level rise is produced. This research found that the city needs to address strategies to anticipate the exacerbating impacts of the sea level rise by managing its coastal spatial planning and modify its drainage system, especially at the drainage outlets.

  14. Quantification of Multiple Climate Change and Human Activity Impact Factors on Flood Regimes in the Pearl River Delta of China

    Directory of Open Access Journals (Sweden)

    Yihan Tang

    2016-01-01

    Full Text Available Coastal flood regimes have been irreversibly altered by both climate change and human activities. This paper aims to quantify the impacts of multiple factors on delta flood. The Pearl River Delta (PRD, with dense river network and population, is one of the most developed coastal areas in China. The recorded extreme water level (m.s.l. in flood season has been heavily interfered with by varied income flood flow, sea-level rise, and dredged riverbeds. A methodology, composed of a numerical model and the index R, has been developed to quantify the impacts of these driving factors in the the PRD. Results show that the flood level varied 4.29%–53.49% from the change of fluvial discharge, 3.35%–38.73% from riverbed dredging, and 0.12%–16.81% from sea-level rise. The variation of flood flow apparently takes the most effect and sea-level rise the least. In particular, dense river network intensifies the impact of income flood change and sea-level rise. Findings from this study help understand the causes of the the PRD flood regimes and provide theoretical support for flood protection in the delta region.

  15. The hydro-geomorphological event of December 1909 in Iberia: social impacts and triggering conditions

    Science.gov (United States)

    Pereira, Susana; Ramos, Alexandre M.; Zêzere, José L.; Trigo, Ricardo M.; Vaquero, José M.

    2015-04-01

    According to the Disaster database (Zêzere et al., 2014), a Disaster event is a set of flood and landslide cases sharing the same trigger, which may have a widespread spatial extension and a certain magnitude. The Disaster event with the highest number of floods and landslides cases occurred in Portugal in the period 1865-2010 was registered between 20 and 28 December 1909. This event also caused important socioeconomic impacts over the Spanish territory, especially in the Douro basin and in the northern section of the Tagus basin. Despite such widespread impact in western Iberia there is no scientific publication addressing the triggering conditions and the social consequences of this disastrous event. Therefore, this work aims to characterize the spatial distribution and social impacts of the December 1909 hydro-geomorphologic event over Iberia. In addition, the meteorological conditions that triggered the event are analysed using the 20 Century Reanalysis dataset from NOAA and rainfall data from Iberian meteorological stations. The historical data source used to analyse the event of December 1909 in Portugal is the Disaster Database (Zêzere et al., 2014). This database contains detailed data on the spatial location and social impacts (fatalities, injuries, missing people, evacuated and homeless people) of hydro-geomorphologic disasters (flood and landslide cases) occurred in Portugal (1865-2010) and referred in newspapers. In Spain the data collection process was supported by the systematic analysis of daily newspapers and using the same entry criteria of the Disaster database, to ensure data integrity and enable comparison with Portuguese records. The Iberian Peninsula was spatially affected during this event along the SW-NE direction spanning between Lisbon, Santarém, Porto and Guarda (in Portugal), until Salamanca, Valladolid, Zamora, Orense, León, Palencia (in Spain). The social and economic impacts of the December 1909 disaster event were higher on the

  16. Simulating past severe flood events to evaluate the effectiveness of nonstructural flood countermeasures in the upper Chao Phraya River Basin, Thailand

    Directory of Open Access Journals (Sweden)

    Sarawut Jamrussri

    2017-04-01

    Their effectiveness in the Upper Chao Phraya River Basin was quantitatively assessed by comparing the model results for the actual conditions with the scenario results. Results showed that the proposed nonstructural measures had considerable potential to reduce peak discharges and flood volumes in the Upper Chao Phraya River Basin. Integration of these proposed nonstructural flood countermeasures with the existing countermeasures in the Chao Phraya River Basin may be the most practical way to cope with the challenges of future flood disasters.

  17. Nonlinear impacts of small-scale natural events on Nineteenth Century human decision-making

    Science.gov (United States)

    McCormack, S. M.; Schlichting, K. M.; Urbanova, T.; Allen, T. L.; Ruffing, C. M.; Hermans, C. M.

    2009-12-01

    Natural climatological events that occurred throughout the Nineteenth Century, such as floods, droughts and hurricanes had long-lived, far-reaching consequences on the human decision-making processes occurring in the northeast United States. These events impacted the hydrological cycle, both directly -though the building of various structures- and indirectly - through an increased understanding of science; and the changing relationship between humans and their environment. This paper examines these events and associated processes through: 1) identifying specific natural events throughout the time period, occurring globally, with initial conditions conducive to long-lived consequences; 2) examining the relationship between scientific enquiry, natural events and the proliferation of dams in the northeast landscape; and 3) the growth of public health concerns, awareness of bacteriology, and municipal water supply systems. Results of this research indicate that the relationship between knowledge systems, natural events and subsequent engineering or technological fixes is complex and highly dependent on initial conditions. It highlights the time period where humans became increasingly dependent on engineered solutions to environmental problems, many of which still hold fast in our contemporary landscape. It is relevant to natural, social and governance structures in place today. The principles behind the occurrence of the natural phenomena and subsequent research and design have not changed; and understanding key events or stages in the past is tantamount to making predictions for the future.

  18. Economics of extreme weather events: Terminology and regional impact models

    Directory of Open Access Journals (Sweden)

    Malte Jahn

    2015-12-01

    Full Text Available Impacts of extreme weather events are relevant for regional (in the sense of subnational economies and in particular cities in many aspects. Cities are the cores of economic activity and the amount of people and assets endangered by extreme weather events is large, even under the current climate. A changing climate with changing extreme weather patterns and the process of urbanization will make the whole issue even more relevant in the future. In this paper, definitions and terminology in the field of extreme weather events are discussed. Possible regional impacts of extreme weather events are collected, focusing on European cities. The human contributions to those impacts are emphasized. Furthermore, methodological aspects of economic impact assessment are discussed along a temporal and a sectoral dimension. Finally, common economic impact models are compared, analyzing their strengths and weaknesses.

  19. Impacts of Climate Change On The Occurrence of Extreme Events: The Mice Project

    Science.gov (United States)

    Palutikof, J. P.; Mice Team

    It is widely accepted that climate change due to global warming will have substan- tial impacts on the natural environment, and on human activities. Furthermore, it is increasingly recognized that changes in the severity and frequency of extreme events, such as windstorm and flood, are likely to be more important than changes in the average climate. The EU-funded project MICE (Modelling the Impacts of Climate Extremes) commenced in January 2002. It seeks to identify the likely changes in the occurrence of extremes of rainfall, temperature and windstorm due to global warm- ing, using information from climate models as a basis, and to study the impacts of these changes in selected European environments. The objectives are: a) to evaluate, by comparison with gridded and station observations, the ability of climate models to successfully reproduce the occurrence of extremes at the required spatial and temporal scales. b) to analyse model output with respect to future changes in the occurrence of extremes. Statistical analyses will determine changes in (i) the return periods of ex- tremes, (ii) the joint probability of extremes (combinations of damaging events such as windstorm followed by heavy rain), (iii) the sequential behaviour of extremes (whether events are well-separated or clustered) and (iv) the spatial patterns of extreme event occurrence across Europe. The range of uncertainty in model predictions will be ex- plored by analysing changes in model experiments with different spatial resolutions and forcing scenarios. c) to determine the impacts of the predicted changes in extremes occurrence on selected activity sectors: agriculture (Mediterranean drought), commer- cial forestry and natural forest ecosystems (windstorm and flood in northern Europe, fire in the Mediterranean), energy use (temperature extremes), tourism (heat stress and Mediterranean beach holidays, changes in the snow pack and winter sports ) and civil protection/insurance (windstorm and flood

  20. Land cover change impact on urban flood modeling (case study: Upper Citarum watershed)

    Science.gov (United States)

    Siregar, R. I.

    2018-03-01

    The upper Citarum River watershed utilizes remote sensing technology in Geographic Information System to provide information on land coverage by interpretation of objects in the image. Rivers that pass through urban areas will cause flooding problems causing disadvantages, and it disrupts community activities in the urban area. Increased development in a city is related to an increase in the number of population growth that added by increasing quality and quantity of life necessities. Improved urban lifestyle changes have an impact on land cover. The impact in over time will be difficult to control. This study aims to analyze the condition of flooding in urban areas caused by upper Citarum watershed land-use change in 2001 with the land cover change in 2010. This modeling analyzes with the help of HEC-RAS to describe flooded inundation urban areas. Land cover change in upper Citarum watershed is not very significant; it based on the results of data processing of land cover has the difference of area that changed is not enormous. Land cover changes for the floods increased dramatically to a flow coefficient for 2001 is 0.65 and in 2010 at 0.69. In 2001, the inundation area about 105,468 hectares and it were about 92,289 hectares in 2010.

  1. Impact of extreme weather events and climate change for health and social care systems.

    Science.gov (United States)

    Curtis, Sarah; Fair, Alistair; Wistow, Jonathan; Val, Dimitri V; Oven, Katie

    2017-12-05

    This review, commissioned by the Research Councils UK Living With Environmental Change (LWEC) programme, concerns research on the impacts on health and social care systems in the United Kingdom of extreme weather events, under conditions of climate change. Extreme weather events considered include heatwaves, coldwaves and flooding. Using a structured review method, we consider evidence regarding the currently observed and anticipated future impacts of extreme weather on health and social care systems and the potential of preparedness and adaptation measures that may enhance resilience. We highlight a number of general conclusions which are likely to be of international relevance, although the review focussed on the situation in the UK. Extreme weather events impact the operation of health services through the effects on built, social and institutional infrastructures which support health and health care, and also because of changes in service demand as extreme weather impacts on human health. Strategic planning for extreme weather and impacts on the care system should be sensitive to within country variations. Adaptation will require changes to built infrastructure systems (including transport and utilities as well as individual care facilities) and also to institutional and social infrastructure supporting the health care system. Care sector organisations, communities and individuals need to adapt their practices to improve resilience of health and health care to extreme weather. Preparedness and emergency response strategies call for action extending beyond the emergency response services, to include health and social care providers more generally.

  2. Forecasting surface water flooding hazard and impact in real-time

    Science.gov (United States)

    Cole, Steven J.; Moore, Robert J.; Wells, Steven C.

    2016-04-01

    Across the world, there is increasing demand for more robust and timely forecast and alert information on Surface Water Flooding (SWF). Within a UK context, the government Pitt Review into the Summer 2007 floods provided recommendations and impetus to improve the understanding of SWF risk for both off-line design and real-time forecasting and warning. Ongoing development and trial of an end-to-end real-time SWF system is being progressed through the recently formed Natural Hazards Partnership (NHP) with delivery to the Flood Forecasting Centre (FFC) providing coverage over England & Wales. The NHP is a unique forum that aims to deliver coordinated assessments, research and advice on natural hazards for governments and resilience communities across the UK. Within the NHP, a real-time Hazard Impact Model (HIM) framework has been developed that includes SWF as one of three hazards chosen for initial trialling. The trial SWF HIM system uses dynamic gridded surface-runoff estimates from the Grid-to-Grid (G2G) hydrological model to estimate the SWF hazard. National datasets on population, infrastructure, property and transport are available to assess impact severity for a given rarity of SWF hazard. Whilst the SWF hazard footprint is calculated in real-time using 1, 3 and 6 hour accumulations of G2G surface runoff on a 1 km grid, it has been possible to associate these with the effective rainfall design profiles (at 250m resolution) used as input to a detailed flood inundation model (JFlow+) run offline to produce hazard information resolved to 2m resolution. This information is contained in the updated Flood Map for Surface Water (uFMfSW) held by the Environment Agency. The national impact datasets can then be used with the uFMfSW SWF hazard dataset to assess impacts at this scale and severity levels of potential impact assigned at 1km and for aggregated county areas in real-time. The impact component is being led by the Health and Safety Laboratory (HSL) within the NHP

  3. Variation in experimental flood impacts and ecogeomorphic feedbacks among native and exotic riparian tree seedlings

    Science.gov (United States)

    Kui, L.; Stella, J. C.; Skorko, K.; Lightbody, A.; Wilcox, A. C.; Bywater-Reyes, S.

    2012-12-01

    Flooding interacts with riparian plants on a variety of scales, resulting in coevolution of geomorphic surfaces with plant vegetation communities. Our research aims to develop a mechanistic understanding of riparian seedling damage from small floods, with a focus on differential responses among species (native and non-native), ecogeomorphic feedbacks, and implications for riparian restoration. We tested the effects of controlled flood events on cottonwood (Populus fremontii) and tamarisk (Tamarix spp.) seedlings in an experimental meandering stream channel. We hypothesized that seedling dislodgement and burial would be influenced by individual plant height, species-specific morphology, patch density, and differences in hydraulic forces (as a function of location on the bar). Four experimental floods were tested, with different combinations of plant species and seedling densities. For each flood run, rooted seedlings were installed within a 1.5-m-wide sandbar during low flow conditions and stream discharge was increased to a constant flood level for approximately 8 hours, after which seedling response was assessed. Seedling damage was analyzed within a logistic regression framework that predicted the probability of dislodgement or burial as a function of the explanatory variables. Plant dislodgement depended on root length and the location on the sandbar, whereas burial depended on plant height, species-specific morphology, and location. For every centimeter increase in plant height, the odds of plant burial decreased by 10 percent, illustrating the rate at which plants developed flood resistance as they grow taller. With every meter closer to the thalweg, plant dislodgement was four times more likely, and plant burial was 2.6 times more likely. The probability of burial was twice as great for tamarisk seedlings as for cottonwood. The increased sedimentation within tamarisk patches was associated with a denser foliage and a more compact crown for this species. The

  4. The impact of recurrent disasters on mental health: a study on seasonal floods in northern India.

    Science.gov (United States)

    Wind, Tim R; Joshi, Pooran C; Kleber, Rolf J; Komproe, Ivan H

    2013-06-01

    Very little is known on the impact of recurrent disasters on mental health. Aim The present study examines the immediate impact of a recurrent flood on mental health and functioning among an affected population in the rural district of Bahraich, Uttar Pradesh, India, compared with a population in the same region that is not affected by floods. The study compared 318 affected respondents with 308 individuals who were not affected by floods. Symptoms of anxiety and depression were assessed by the Hopkins Symptom Checklist-25 (HSCL-25). Psychological and physical functioning was assessed by using the Short Form-12 (SF-12). The affected group showed large to very large differences with the comparison group on symptoms of anxiety (D = .92) and depression (D = 1.22). The affected group scored significantly lower on psychological and physical functioning than the comparison group (respectively D = .33 and D = .80). However, hierarchical linear regressions showed no significant relationship between mental health and the domains of functioning in the affected group, whereas mental health and the domains of functioning were significantly related in the comparison group. This study found a large negative impact of the recurrent floods on mental health outcomes and psychological and physical functioning. However, in a context with recurrent floods, disaster mental health status is not a relevant predictor of functioning. The findings suggest that the observed mental health status and impaired functioning in this context are also outcomes of another mechanism: Both outcomes are likely to be related to the erosion of the social and environmental and material context. As such, the findings refer to a need to implement psychosocial context-oriented interventions to address the erosion of the context rather than specific mental health interventions.

  5. Metals impact into the Paranaguá Estuarine Complex (Brazil during the exceptional flood of 2011

    Directory of Open Access Journals (Sweden)

    Marilia Lopes da Rocha

    Full Text Available Abstract Particulate and dissolved metal concentrations were determined after the largest flood in the last 30 years on the east-west axis of the Paranaguá Estuarine Complex (PEC and compared to the those of the dry period at two stations. Results confirmed that the flood greatly affected riverine outflows and the behavior of metals in the PEC. In particular, a sharp decrease in salinity was followed by extremely high SPM concentrations leading to a decrease in DO concentrations at both stations. For the dissolved phase, ANOSIM analysis showed a significant dissimilarity at each station between the sampled periods, whereas for the particulate phase this dissimilarity was found only for the samplings taken at the Antonina Station. KD values suggested dissolved Cu behavior was related to the presence of organic complexes and dissolved Mn had sediment resuspension of redox sediments and or/pore water injection as sources. Metal concentrations were lower than in polluted estuaries, though high enrichment factors found after the flood pointed to the influence of anthropogenic sources. In conclusion, the flood's influence was more evident at the Antonina Station, due to its location in the upper estuary, whereas in Paranaguá a high SPM content with low metal concentration was found, following the common pattern generally found in other marine systems subject to heavy rainfall events.

  6. Hydrological Design of Nonstationary Flood Extremes and Durations in Wujiang River, South China: Changing Properties, Causes, and Impacts

    Directory of Open Access Journals (Sweden)

    Xiaohong Chen

    2013-01-01

    Full Text Available The flood-duration-frequency (QDF analysis is performed using annual maximum streamflow series of 1–10 day durations observed at Pingshi and Lishi stations in southern China. The trends and change point of annual maximum flood flow and flood duration are also investigated by statistical tests. The results indicate that (1 the annual maximum flood flow only has a marginally increasing trend, whereas the flood duration exhibits a significant decreasing trend at the 0.10 significant level. The change point for the annual maximum flood flow series was found in 1991 and after which the mean maximum flood flow increased by 45.26%. (2 The period after 1991 is characterized by frequent and shorter duration floods due to increased rainstorm. However, land use change in the basin was found intensifying the increased tendency of annual maximum flow after 1991. And (3 under nonstationary environmental conditions, alternative definitions of return period should be adapted. The impacts on curve fitting of flood series showed an overall change of upper tail from “gentle” to “steep,” and the design flood magnitude became larger. Therefore, a nonstationary frequency analysis taking account of change point in the data series is highly recommended for future studies.

  7. The use of water marks mapping to understand flood overflow events inside karstic cavities: Cueva Fría and Cueva Rosa (Asturias, NW Spain)

    Science.gov (United States)

    González Lemos, Saúl; Stoll, Heather M.

    2014-05-01

    Several karst systems in Asturias (NW Spain) present evidence of fluvial deposits cemented in speleothems that may provide good chronology of past flood events inside the caves. This flood record is under research in two karstic caves of this region, Cueva Fría and Cueva Rosa, which have in common the presence of a perennial stream inside the cave and a low gradient of the cave passage. Immediately after a flood overflow event, water marks, foam and detritus are visible at different heights on the cave walls and correspond to heights of bottlenecks in overflow drainage through the cave passage. Flood events also deposit sand and gravel on terraces on the cave wall and move large volumes of sand in the cave bed. We have noted that detrital particles (like sand or silt particles) are preserved as inclusions inside the stalagmites and that their abundance inside coeval stalagmites decreases as altitude and distance from the perennial stream increase, supporting its fluvial affinity. However, not all the stalagmites that contain detrital particles are located close to the perennial streams. In this work, we have mapped the water marks preserved in the cave walls to reconstruct water levels associated to flood overflow events of different magnitude. We have found that water mark correlation along the cave passage is very useful to define the hydrological behaviour and flood model of the cave during these extreme events. The water mark mapping and correlation have been also useful to prove that during periods of high rainfall, the movement of the sand-bars inside the cave can cover partially or completely active stalagmites, facilitating the cementation process and trapping abundant detrital material inside the stalagmite carbonate. 14C and U/Th dating of the stalagmites can provide a chronology for the detrital rich layers, so that the abundance of fluvial material in the stalagmites can reveal periods of enhanced vs. reduced flooding in the cave over the past several

  8. Predicting the Impacts of Rural Catchment Changes on Runoff Generation and Flooding

    Science.gov (United States)

    Enda O'Connell, P.; Ewen, John; O'Donnell, Greg

    2010-05-01

    While urbanization is widely associated with changes to the runoff generation and flooding regimes of catchments worldwide, the rural landscape has also undergone major changes. Over the past fifty years, much of the European landscape has been transformed as a result of changes in land use and management. The growth in intensive agriculture and associated farming practices have changed natural hydrological functioning at the field/hillslope scale, and as a consequence, flood generation mechanisms at the catchment scale may have been affected. In the UK, there is evidence that soil compaction/degradation has created local scale flooding problems, but it is not clear how flood generation at larger catchment scales may have been affected. A wide range of interventions associated with farming and land use management (e.g. land drainage etc) complicate the overall picture. Similar problems have been observed ad documented in other European countries, and there is the added concern about how the catchments will respond to the more extreme rainfall regimes expected under climate change. There is also frequent controversy over the impacts of afforestation and deforestation in the uplands on lowland floods, particularly in Asia. There is a pressing need for modelling tools that can provide predictions of the impacts of anthropogenic interventions, whether urban or rural, on the downstream flooding regimes of catchments. Central to the prediction problem is the scale issue: how do local scale changes to runoff generation propagate to larger catchment scales and create impacts? An integrated programme of multiscale catchment experimentation and modelling is being undertaken in the UK to gain a better understanding of how small scale changes in runoff generation propagate to larger catchment scales, and to support decision-making on flood risk mitigation. New modelling tools have been developed which can be used to assess impacts and guide management interventions. The first

  9. Modelling the Impacts of Changing Land Cover/Land Use and Climate on Flooding in the Elk River Watershed, British Columbia

    Science.gov (United States)

    Barnes, C. C.; Byrne, J. M.; Hopkinson, C.; MacDonald, R. J.; Johnson, D. L.

    2015-12-01

    The Elk River is a mountain watershed located along the eastern border of British Columbia, Canada. The Elk River is confined by railway bridges, roads, and urban areas. Flooding has been a concern in the valley for more than a century. The most recent major flood event occurred in 2013 affecting several communities. River modifications such as riprapped dykes, channelization, and dredging have occurred in an attempt to reduce inundation, with limited success. Significant changes in land cover/land use (LCLU) such as natural state to urban, forestry practices, and mining from underground to mountaintop/valley fill have changed terrain and ground surfaces thereby altering water infiltration and runoff processes in the watershed. Future climate change in this region is expected to alter air temperature and precipitation as well as produce an earlier seasonal spring freshet potentially impacting future flood events. The objective of this research is to model historical and future hydrological conditions to identify flood frequency and risk under a range of climate and LCLU change scenarios in the Elk River watershed. Historic remote sensing data, forest management plans, and mining industry production/post-mining reclamation plans will be used to create a predictive past and future LCLU time series. A range of future air temperature and precipitation scenarios will be developed based on accepted Global Climate Modelling (GCM) research to examine how the hydrometeorological conditions may be altered under a range of future climate scenarios. The GENESYS (GENerate Earth SYstems Science input) hydrometeorological model will be used to simulate climate and LCLU to assess historic and potential future flood frequency and magnitude. Results will be used to create innovative flood mitigation, adaptation, and management strategies for the Elk River with the intent of being wildlife friendly and non-destructive to ecosystems and habitats for native species.

  10. How crucial is it to account for the antecedent moisture conditions in flood forecasting? Comparison of event-based and continuous approaches on 178 catchments

    Directory of Open Access Journals (Sweden)

    L. Berthet

    2009-06-01

    Full Text Available This paper compares event-based and continuous hydrological modelling approaches for real-time forecasting of river flows. Both approaches are compared using a lumped hydrologic model (whose structure includes a soil moisture accounting (SMA store and a routing store on a data set of 178 French catchments. The main focus of this study was to investigate the actual impact of soil moisture initial conditions on the performance of flood forecasting models and the possible compensations with updating techniques. The rainfall-runoff model assimilation technique we used does not impact the SMA component of the model but only its routing part. Tests were made by running the SMA store continuously or on event basis, everything else being equal. The results show that the continuous approach remains the reference to ensure good forecasting performances. We show, however, that the possibility to assimilate the last observed flow considerably reduces the differences in performance. Last, we present a robust alternative to initialize the SMA store where continuous approaches are impossible because of data availability problems.

  11. Sedimentary and rock magnetic signatures and event scenarios of deglacial outburst floods from the Laurentian Channel Ice Stream

    Science.gov (United States)

    Leng, Wei; von Dobeneck, Tilo; Bergmann, Fenna; Just, Janna; Mulitza, Stefan; Chiessi, Cristiano M.; St-Onge, Guillaume; Piper, David J. W.

    2018-04-01

    Eastern Canadian margin sediments bear testimony to several catastrophic deglacial meltwater discharges from the retreating Laurentide Ice Sheet. The reddish-brown plumite layers deposited on the levees of the Laurentian Fan valleys have been recognized as indications of multiple outburst floods between Heinrich events 2 and 1. Five event layers have been consistently recorded in three new gravity cores retrieved on the SW Grand Banks slope and comply with the previously published Laurentian Fan core MD95-2029. The apparently huge extent of these outburst plumes around the Laurentian Fan as well as their causes and consequences are investigated in this study using physical properties, rock magnetic and grain-size analyses, together with seismoacoustic profiling. We provide the first detailed 14C ages of the outburst event sequence and discuss their recurrence intervals in the context of regional ice retreat. Compared to the hemipelagic interlayers, event layers have overall uniform and systematic changes of rock-magnetic properties. Hematite contents increase over time and proximally while magnetite grain sizes fine upwards and spatially away from the fan. Based on the sediment composition and load, we argue that these plumites were formed by recurrent erosion of glacial mud deposits in the Laurentian Channel by meltwater outbursts. Three alternative glaciological scenarios are evaluated: in each case, the provenance of the transported sediment is not an indicator of the precise source of the meltwater.

  12. High Resolution Simulations of a Severe Hail Storm and Flooding Event over La Paz city with WRF

    Science.gov (United States)

    Zamuriano, Marcelo; Brönnimann, Stefan

    2016-04-01

    On February 19, 2002 a very local hail storm and a flash flood episode occurred in La Paz city, Bolivia. About 40 millimeters of precipitation in over an hour was observed, it was the strongest rainfall registered until that date. This event caused at least 69 causalities and important damages to the city's infrastructure, being considered as an exceptional natural disaster. It is thought that the vertical humid air motion driven by the high surface temperatures and topographical forcing is the responsible of such event, nevertheless a formal study about the atmospheric features leading to this episode has not been done yet. In order to overcome this issue, a series of high resolution numerical experiments with the WRF-ARW model is conducted using two global datasets: GFS and ECMWF. Several micro-physics schemes are used in a four-nested domain configuration with 2 kilometers as finest resolution, giving more details about the effects topography on this event. Overall, high-resolution simulations improves the spatial distribution of rainfall and represents better the local atmospheric circulation leading to this extreme event.

  13. Chemistry of impact events on Mercury

    Science.gov (United States)

    Berezhnoy, Alexey A.

    2018-01-01

    Based on the equilibrium thermochemical approach and quenching theory, formation of molecules and dust grains in impact-produced clouds formed after collisions between meteoroids and Mercury is considered. Based on observations of Al, Fe, and Mn atoms in the exosphere of Mercury and new results of studies of the elemental composition of the surface of Mercury, quenching temperatures and pressures of main chemical reactions and condensation of dust particles were estimated. The behavior of the main Na-, K-, Ca-, Fe-, Al-, Mn-, Mg-, Si-, Ti, Ni-, Cr-, Co, Zn-, O-, H-, S-, C-, Cl-, N-, and P-containing species delivered to the Hermean exosphere during meteoroid impacts was studied. The importance of meteoroid bombardment as a source of Na, K, Ca, Fe, Al, Mn, Mg, and O atoms in the exosphere of Mercury is discussed.

  14. The Tunguska impact event and beyond

    Science.gov (United States)

    Napier, Bill; Asher, David

    2009-02-01

    Current strategies for dealing with the impact hazard are geared towards the detection and deflection of near-Earth asteroids, which typically have approach speeds ~20 km s-1 and involve decades of warning. However, galactic signals in the age distribution of well-dated impact craters suggest that the globally destructive impactors (diameters between 1.5 and 2 km and upwards) ultimately derive from the Oort cloud. Warning times are then measured in months or days, and characteristic approach speeds are ~55 km s-1. Concentrations of sub-kilometre debris in meteor streams may also be a significant regional hazard. Intersection with the debris of a large short-period comet may account for the widespread biological and cultural dislocation in North America around 12 900 BP.

  15. Changes in toxicity and Ah receptor agonist activity of suspended particulate matter during flood events at the rivers Neckar and Rhine - a mass balance approach using in vitro methods and chemical analysis.

    Science.gov (United States)

    Wölz, Jan; Engwall, Magnus; Maletz, Sibylle; Olsman Takner, Helena; van Bavel, Bert; Kammann, Ulrike; Klempt, Martin; Weber, Roland; Braunbeck, Thomas; Hollert, Henner

    2008-10-01

    As a consequence of flood events, runoff and remobilized sediments may cause an increase of ecotoxicologically relevant effects from contaminant reservoirs. Aquatic and terrestrial organisms as well as cattle and areas of settlement are exposed to dislocated contaminants during and after flood events. In this study, the impacts of two flood events triggered by intense rain at the rivers Neckar and Rhine (Southern Germany) were studied. Effects in correlation to flood flow were assessed at the river Neckar using samples collected at frequent intervals. River Rhine suspended particulate matter (SPM) was sampled over a longer period at normal flow and during a flood event. Three cell lines (H4L1.1c4, GPC.2D.Luc, RTL-W1) were used to compare Ah receptor agonist activity in different biotest systems. Multilayer fractionation was performed to identify causative compounds, focusing on persistent organic contaminants. Native water and SPM of flood events were collected at the river Neckar and at the monitoring station (Rheinguetestation, Worms, Germany) of the river Rhine. Water samples were XAD-extracted. SPM were freeze-dried and Soxhlet-extracted using acetone and finally dissolved in dimethyl sulfoxide. Resulting crude extracts were analyzed for cytotoxicity with the neutral red assay. Aryl hydrocarbon receptor (AhR) agonist activity was measured in a set of biological test systems (DR-CALUX, GPC.2D, and ethoxyresorufin-O-deethylase (EROD) assay) and different cell lines. In addition, crude extracts were fractionated using a combined method of multilayer (sequence of acidified silica layers) and carbon fractionation. Fractions from the multilayer fractionation contained persistent organic compounds (polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and some polycyclic aromatic hydrocarbon (PAHs)); fractions from the carbon fractionation were separated into a PCDD/F and a PCB fraction. Dioxin-like activity of multilayer and

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

    Science.gov (United States)

    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.

  17. Anthropogenic impact on flood-risk: a large-scale assessment for planning controlled inundation strategies along the River Po

    Science.gov (United States)

    Domeneghetti, Alessio; Castellarin, Attilio; Brath, Armando

    2013-04-01

    The European Flood Directive (2007/60/EC) has fostered the development of innovative and sustainable approaches and methodologies for flood-risk mitigation and management. Furthermore, concerning flood-risk mitigation, the increasing awareness of how the anthropogenic pressures (e.g. demographic and land-use dynamics, uncontrolled urban and industrial expansion on flood-prone area) could strongly increase potential flood damages and losses has triggered a paradigm shift from "defending the territory against flooding" (e.g. by means of levee system strengthening and heightening) to "living with floods" (e.g. promoting compatible land-uses or adopting controlled flooding strategies of areas located outside the main embankments). The assessment of how socio-economic dynamics may influence flood-risk represents a fundamental skill that should be considered for planning a sustainable industrial and urban development of flood-prone areas, reducing their vulnerability and therefore minimizing socio-economic and ecological losses due to large flood events. These aspects, which are of fundamental importance for Institutions and public bodies in charge of Flood Directive requirements, need to be considered through a holistic approach at river basin scale. This study focuses on the evaluation of large-scale flood-risk mitigation strategies for the middle-lower reach of River Po (~350km), the longest Italian river and the largest in terms of streamflow. Due to the social and economical importance of the Po River floodplain (almost 40% of the total national gross product results from this area), our study aims at investigating the potential of combining simplified vulnerability indices with a quasi-2D model for the definition of sustainable and robust flood-risk mitigation strategies. Referring to past (1954) and recent (2006) land-use data sets (e.g. CORINE) we propose simplified vulnerability indices for assessing potential flood-risk of industrial and urbanized flood prone

  18. Catastrophic Events and Mass Extinctions: Impacts and Beyond

    Science.gov (United States)

    2000-01-01

    This volume contains extended abstracts that have been accepted for presentation at the conference on Catastrophic Events and Mass Extinctions: Impacts and Beyond, July 9-12, 2000, in Vienna, Austria.

  19. Impacts of spatial resolution and representation of flow connectivity on large-scale simulation of floods

    Science.gov (United States)

    Mateo, Cherry May R.; Yamazaki, Dai; Kim, Hyungjun; Champathong, Adisorn; Vaze, Jai; Oki, Taikan

    2017-10-01

    Global-scale river models (GRMs) are core tools for providing consistent estimates of global flood hazard, especially in data-scarce regions. Due to former limitations in computational power and input datasets, most GRMs have been developed to use simplified representations of flow physics and run at coarse spatial resolutions. With increasing computational power and improved datasets, the application of GRMs to finer resolutions is becoming a reality. To support development in this direction, the suitability of GRMs for application to finer resolutions needs to be assessed. This study investigates the impacts of spatial resolution and flow connectivity representation on the predictive capability of a GRM, CaMa-Flood, in simulating the 2011 extreme flood in Thailand. Analyses show that when single downstream connectivity (SDC) is assumed, simulation results deteriorate with finer spatial resolution; Nash-Sutcliffe efficiency coefficients decreased by more than 50 % between simulation results at 10 km resolution and 1 km resolution. When multiple downstream connectivity (MDC) is represented, simulation results slightly improve with finer spatial resolution. The SDC simulations result in excessive backflows on very flat floodplains due to the restrictive flow directions at finer resolutions. MDC channels attenuated these effects by maintaining flow connectivity and flow capacity between floodplains in varying spatial resolutions. While a regional-scale flood was chosen as a test case, these findings should be universal and may have significant impacts on large- to global-scale simulations, especially in regions where mega deltas exist.These results demonstrate that a GRM can be used for higher resolution simulations of large-scale floods, provided that MDC in rivers and floodplains is adequately represented in the model structure.

  20. Impacts of spatial resolution and representation of flow connectivity on large-scale simulation of floods

    Directory of Open Access Journals (Sweden)

    C. M. R. Mateo

    2017-10-01

    Full Text Available Global-scale river models (GRMs are core tools for providing consistent estimates of global flood hazard, especially in data-scarce regions. Due to former limitations in computational power and input datasets, most GRMs have been developed to use simplified representations of flow physics and run at coarse spatial resolutions. With increasing computational power and improved datasets, the application of GRMs to finer resolutions is becoming a reality. To support development in this direction, the suitability of GRMs for application to finer resolutions needs to be assessed. This study investigates the impacts of spatial resolution and flow connectivity representation on the predictive capability of a GRM, CaMa-Flood, in simulating the 2011 extreme flood in Thailand. Analyses show that when single downstream connectivity (SDC is assumed, simulation results deteriorate with finer spatial resolution; Nash–Sutcliffe efficiency coefficients decreased by more than 50 % between simulation results at 10 km resolution and 1 km resolution. When multiple downstream connectivity (MDC is represented, simulation results slightly improve with finer spatial resolution. The SDC simulations result in excessive backflows on very flat floodplains due to the restrictive flow directions at finer resolutions. MDC channels attenuated these effects by maintaining flow connectivity and flow capacity between floodplains in varying spatial resolutions. While a regional-scale flood was chosen as a test case, these findings should be universal and may have significant impacts on large- to global-scale simulations, especially in regions where mega deltas exist.These results demonstrate that a GRM can be used for higher resolution simulations of large-scale floods, provided that MDC in rivers and floodplains is adequately represented in the model structure.

  1. Sport events and their socio-economic impact: residents ...

    African Journals Online (AJOL)

    Sport events have become big business as countries as well as cities are competing fi ercely to host major events. The purpose of this article is to determine the economic impact of visitor spending during the annual Cape Argus Pick 'n Pay Cycle Tour. Direct spending was determined based on a survey consisting of 583 ...

  2. Challenges in Downscaling Surge and Flooding Predictions Associated with Major Coastal Storm Events

    Science.gov (United States)

    Bowman, M. J.

    2015-12-01

    Coastal zone managers, elected officials and emergency planning personnel are continually seeking more reliable estimates of storm surge and inundation for better land use planning, the design, construction and operation of coastal defense systems, resilience evaluation and evacuation planning. Customers of modern regional weather and storm surge prediction models demand high resolution, speed, accuracy, with informative, interactive graphics and easy evaluation of potentially dangerous threats to life and property. These challenges continue to get more difficult as the demand for street-scale and even building-scale predictions increase. Fluctuations in sub-grid-scale wind and water velocities can lead to unsuspected, unanticipated and dangerous flooding in local communities. But how reliable and believable are these models given the inherent natural uncertainty and chaotic behavior in the underlying dynamics, which can lead to rapid and unexpected perturbations in the wind and pressure fields and hence coastal flooding? Traditionally this uncertainty has been quantified by the use of the ensemble method, where a suite of model runs are made with varying physics and initial conditions, presenting the mean and variance of the ensemble as the best metrics possible. But this assumes that each component is equally possible and is statistically independent of the others. But this is rarely true, although the "safety in numbers" approach is comforting to those faced with life and death decisions. An example of the ensemble method is presented for the trajectory of superstorm Sandy's storm center as it approached coastal New Jersey. If one were to ask the question "was Sandy a worst case scenario", the answer would be "no: small variations in the timing (vis-à-vis tide phase) and location of landfall could easily have led to an additional surge of +50 cm at The Battery NY with even more catastrophic consequences to those experienced".

  3. Impact of extreme floods on fishes in rivers and their floodplains

    Czech Academy of Sciences Publication Activity Database

    Lusk, Stanislav; Hartvich, P.; Halačka, Karel; Lusková, Věra; Holub, M.

    2004-01-01

    Roč. 4, č. 2 (2004), s. 173-181 ISSN 1642-3593. [International Symposium on the Ecology of Fluvial Fishes /9./. Lodz, 23.06.2003-26.06.2003] R&D Projects: GA ČR GA206/03/Z022; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : floods * migration * impact on fishes Subject RIV: EH - Ecology, Behaviour

  4. An experimental system for flood risk forecasting at global scale

    Science.gov (United States)

    Alfieri, L.; Dottori, F.; Kalas, M.; Lorini, V.; Bianchi, A.; Hirpa, F. A.; Feyen, L.; Salamon, P.

    2016-12-01

    Global flood forecasting and monitoring systems are nowadays a reality and are being applied by an increasing range of users and practitioners in disaster risk management. Furthermore, there is an increasing demand from users to integrate flood early warning systems with risk based forecasts, combining streamflow estimations with expected inundated areas and flood impacts. To this end, we have developed an experimental procedure for near-real time flood mapping and impact assessment based on the daily forecasts issued by the Global Flood Awareness System (GloFAS). The methodology translates GloFAS streamflow forecasts into event-based flood hazard maps based on the predicted flow magnitude and the forecast lead time and a database of flood hazard maps with global coverage. Flood hazard maps are then combined with exposure and vulnerability information to derive flood risk. Impacts of the forecasted flood events are evaluated in terms of flood prone areas, potential economic damage, and affected population, infrastructures and cities. To further increase the reliability of the proposed methodology we integrated model-based estimations with an innovative methodology for social media monitoring, which allows for real-time verification of impact forecasts. The preliminary tests provided good results and showed the potential of the developed real-time operational procedure in helping emergency response and management. In particular, the link with social media is crucial for improving the accuracy of impact predictions.

  5. Geographic Information System and Remote Sensing Approach with Hydrologic Rational Model for Flood Event Analysis in Jakarta

    Science.gov (United States)

    Aditya, M. R.; Hernina, R.; Rokhmatuloh

    2017-12-01

    Rapid development in Jakarta which generates more impervious surface has reduced the amount of rainfall infiltration into soil layer and increases run-off. In some events, continuous high rainfall intensity could create sudden flood in Jakarta City. This article used rainfall data of Jakarta during 10 February 2015 to compute rainfall intensity and then interpolate it with ordinary kriging technique. Spatial distribution of rainfall intensity then overlaid with run-off coefficient based on certain land use type of the study area. Peak run-off within each cell resulted from hydrologic rational model then summed for the whole study area to generate total peak run-off. For this study area, land use types consisted of 51.9 % industrial, 37.57% parks, and 10.54% residential with estimated total peak run-off 6.04 m3/sec, 0.39 m3/sec, and 0.31 m3/sec, respectively.

  6. Spatial distribution and frequency of precipitation during an extreme event: July 2006 mesoscale convective complexes and floods in southeastern Arizona

    Science.gov (United States)

    Griffiths, P.G.; Magirl, C.S.; Webb, R.H.; Pytlak, E.; Troch, Peter A.; Lyon, S.W.

    2009-01-01

    An extreme, multiday rainfall event over southeastern Arizona during 27-31 July 2006 caused record flooding and a historically unprecedented number of slope failures and debris flows in the Santa Catalina Mountains north of Tucson. An unusual synoptic weather pattern induced repeated nocturnal mesoscale convective systems over southeastern Arizona for five continuous days, generating multiday rainfall totals up to 360 mm. Analysis of point rainfall and weather radar data yielded storm totals for the southern Santa Catalina Mountains at 754 grid cells approximately 1 km ?? 1 km in size. Precipitation intensity for the 31 July storms was not unusual for typical monsoonal precipitation in this region (recurrence interval (RI) 50 years and individual grid cells had RI exceeding 1000 years. The 31 July storms caused the watersheds to be essentially saturated following 4 days of rainfall. Copyright 2009 by the American Geophysical Union.

  7. Extreme events in the Dudetes Mountains - Their long-term geomorphic impact and possible controlling factors

    Czech Academy of Sciences Publication Activity Database

    Migon, P.; Hrádek, Mojmír; Parzoch, K.

    2002-01-01

    Roč. 36, č. 36 (2002), s. 29-49 ISSN 0081-6434 Institutional research plan: CEZ:AV0Z3086906 Keywords : extreme events * debris flow * landslide-floods Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  8. Esophageal food impaction during cultural holidays and national athletic events.

    Science.gov (United States)

    Shuja, Asim; Winston, Diana M; Rahman, Asad Ur; Mitty, Roger D; Jaber, Bertrand L; Keo, Thormika

    2017-02-01

    Although intrinsic risk factors contributing to esophageal food impaction are well established, whether social behavior affects its occurrence has not yet been examined. We conducted a retrospective review of the gastroenterology endoscopy procedural documentation software for the period of 2001-2012 to identify all patients who presented to our emergency department for esophageal foreign-body removal at the time of national athletic events and holidays associated with dietary indiscretions. We found that adults undergoing emergent esophagogastroduodenoscopy during periods celebrating cultural holidays and national athletic events were more likely to experience esophageal food impaction compared with those undergoing emergent endoscopy during periods not associated with these events (36.8% vs 3.6%; P event period, the most common impacted food item was turkey (50%) followed by chicken (29%) and beef (21%). Esophageal food impaction is more likely to occur on American holidays and national athletic events and is associated with large meals. Patients with intrinsic risk factors should be advised to modify their diet during cultural events associated with tachyphagia and large meals to prevent esophageal food impaction. © The Author(s) 2016. Published by Oxford University Press and Sixth Affiliated Hospital of Sun Yat-Sen University.

  9. Decrease in hydroclimatic conditions generating floods in the southeast of Belgium over the last 50 years resulting from changes in seasonal snow cover and extreme precipitation events

    Science.gov (United States)

    Wyard, Coraline; Fettweis, Xavier

    2016-04-01

    As a consequence of climate change, several studies concluded that winter flood occurrence could increase in the future in many rivers of northern and western Europe in response to an increase in extreme precipitation events. This study aims to determine if trends in extreme hydroclimatic events generating floods can already be detected over the last century. In particular, we focus on the Ourthe River (southeast of Belgium) which is one of the main tributaries of the Meuse River with a catchment area of 3500 km². In this river, most of the floods occur during winter and about 50% of them are due to rainfall events associated with the melting of the snow which covers the Ardennes during winter. In this study, hydroclimatic conditions favorable to flooding were reconstructed over the 20th century using the regional climate model MAR ("Modèle Atmosphérique Régional") forced by the following reanalyses: the ERA-20C, the ERA-Interim and the NCEP/NCAR-v1. The use of the MAR model allows to compute precipitation, snow depth and run-off resulting from precipitation events and snow melting in any part of the Ourthe river catchment area. Therefore, extreme hydroclimatic events, namely extreme run-off events, which could potentially generate floods, can be reconstructed using the MAR model. As validation, the MAR results were compared to weather station-based data. A trend analysis was then performed in order to study the evolution of conditions favorable to flooding in the Ourthe River catchment. The results show that the MAR model allows the detection of more than 95% of the hydroclimatic conditions which effectively generated observed floods in the Ourthe River over the 1974-2014 period. Conditions favorable to flooding present a negative trend over the last 50 years as a result of a decrease in snow accumulation and in extreme precipitation events. However, significance of these trends depends on the reanalysis used to force the regional climate model as well as the

  10. Integrated remote sensing imagery and two-dimensional hydraulic modeling approach for impact evaluation of flood on crop yields

    Science.gov (United States)

    Chen, Huili; Liang, Zhongyao; Liu, Yong; Liang, Qiuhua; Xie, Shuguang

    2017-10-01

    The projected frequent occurrences of extreme flood events will cause significant losses to crops and will threaten food security. To reduce the potential risk and provide support for agricultural flood management, prevention, and mitigation, it is important to account for flood damage to crop production and to understand the relationship between flood characteristics and crop losses. A quantitative and effective evaluation tool is therefore essential to explore what and how flood characteristics will affect the associated crop loss, based on accurately understanding the spatiotemporal dynamics of flood evolution and crop growth. Current evaluation methods are generally integrally or qualitatively based on statistic data or ex-post survey with less diagnosis into the process and dynamics of historical flood events. Therefore, a quantitative and spatial evaluation framework is presented in this study that integrates remote sensing imagery and hydraulic model simulation to facilitate the identification of historical flood characteristics that influence crop losses. Remote sensing imagery can capture the spatial variation of crop yields and yield losses from floods on a grid scale over large areas; however, it is incapable of providing spatial information regarding flood progress. Two-dimensional hydraulic model can simulate the dynamics of surface runoff and accomplish spatial and temporal quantification of flood characteristics on a grid scale over watersheds, i.e., flow velocity and flood duration. The methodological framework developed herein includes the following: (a) Vegetation indices for the critical period of crop growth from mid-high temporal and spatial remote sensing imagery in association with agricultural statistics data were used to develop empirical models to monitor the crop yield and evaluate yield losses from flood; (b) The two-dimensional hydraulic model coupled with the SCS-CN hydrologic model was employed to simulate the flood evolution process

  11. Estimating Agricultural Losses using Flood Modeling for Rural Area

    Directory of Open Access Journals (Sweden)

    Muhadi Nur Atirah

    2017-01-01

    Full Text Available Flooding is the most significant natural hazard in Malaysia in terms of population affected, frequency, flood extent, flood duration and social economic damage. Flooding causes loss of lives, injuries, property damage and leave some economic damage to the country especially when it occurs in a rural area where the main income is dependent on agricultural area. This study focused on flooding in oil palm plantations, rubber plantations and fruits and vegetables area. InfoWorks ICM was used to develop a flood model to study the impact of flooding and to mitigate the floods using a retention pond. Later, Geographical Information System (GIS together with the flood model were used for the analysis on flood damage assessment and management of flood risk. The estimated total damage for three different flood event; 10 ARI, 50 ARI and 100 ARI involved millions of ringgits. In reducing the flood impact along the Selangor River, retention pond was suggested, modeled and tested. By constructing retention pond, flood extents in agricultural area were reduced significantly by 60.49% for 10 ARI, 45.39% for 50 ARI and 46.54% for 100 ARI.

  12. Floods and Flash Flooding

    Science.gov (United States)

    Floods and flash flooding Now is the time to determine your area’s flood risk. If you are not sure whether you ... If you are in a floodplain, consider buying flood insurance. Do not drive around barricades. If your ...

  13. Protective Capacity of Ice Hockey Helmets against Different Impact Events.

    Science.gov (United States)

    Clark, J Michio; Post, Andrew; Hoshizaki, T Blaine; Gilchrist, Michael D

    2016-12-01

    In ice hockey, concussions can occur as a result of many different types of impact events, however hockey helmets are certified using a single injury scenario, involving drop tests to a rigid surface. The purpose of this study is to measure the protective capacity of ice hockey helmets for different impact events in ice hockey. A helmeted and unhelmeted Hybrid III headform were impacted simulating falls, elbow, shoulder and puck impacts in ice hockey. Linear and rotational acceleration and maximum principal strain (MPS) were measured. A comparison of helmeted and unhelmeted impacts found significant differences existed in most conditions (p  0.05). Impacts to the ice hockey helmet tested resulted in acceleration levels below reported ranges of concussion and TBI for falls up to 5 m/s, elbow collisions, and low velocity puck impacts but not for shoulder collisions or high velocity puck impacts and falls. The helmet tested reduced MPS below reported ranges of concussion and TBI for falls up to 5 m/s but not for the other impact events across all velocities and locations. This suggests that the ice hockey helmet tested is unable to reduce engineering parameters below reported ranges of concussion and TBI for impact conditions which do not represent a drop against a rigid surface.

  14. Flood model for Brazil

    Science.gov (United States)

    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

  15. Flash floods and debris flow: how the risk could can be better managed? The case of the events in Sicily on October 2009

    Science.gov (United States)

    Aronica, Giuseppe T.; Brigandi', Giuseppina

    2010-05-01

    Flash floods are phenomena in which the important hydrologic processes are occurring on the same spatial and temporal scales as the intense precipitation. Most of the catchments of the Messina area in the North-East part of Sicily (Italy), are prone to flash flood formation. They are, in fact, small, with a steep slope, and characterised by short concentration times. Moreover, those catchments are predominantly rural in the upper mountainous part, while the areas next to the outlet are highly urbanized with areas that cover not only the floodplain but also the river bed itself as the main roads were previously part of the torrent. This situation involve an high risk of economic losses and human life in case of flash flood in these areas. In the last years the area around Messina has been interested by severe flash floods and debris flow. The events occurred on 25th October 2007 in the Mastroguglielmo torrent and 1st October 2009 on Racinazzi and Gianpilieri torrents are an example of flash floods and debris flow events that caused not only significant economic damages to property, buildings, roads and bridges but also, for this that concern the 1st October 2009 flash flood, loss of human life. The main focus of this work is, basing on the post event analysis of the 2009 flash flood event, to try to understand which could be the better preventive measures and mitigation strategies that can be provided for a better risk management in these areas too many times affected by devastating events. Flood management can be controlled by either structural or non-structural measures. Adoption of a certain measure depends critically on the hydrological and hydraulic characteristics of the river system and the region. Flash flood management includes a number of phases that should be included in any management strategy like prevention, mitigation, preparedness, response and recovery. Forecasting based on hydrological precursors based on the soil moisture condition at the

  16. Groundwater flood or groundwater-induced flood?

    OpenAIRE

    Robins, N.S.; Finch, J.W.

    2012-01-01

    A number of ‘groundwater flood’ events have been recorded over the Chalk aquifer in southern England since the 1994 occurrence at Chichester, Sussex. Reporting of this event and subsequent groundwater floods indicates that there are two types of groundwater flood event. Type 1 is the true groundwater flood in which the water table elevation rises above the ground elevation, and Type 2 occurs when intense groundwater discharge via bourne springs and highly permeable shallow horizons discharges...

  17. Public outreach, participatory communication, and communication impact assessment in Paris flood resilience policies

    Science.gov (United States)

    Vicari, Rosa; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2017-04-01

    Adverse social impacts can reduce the intended benefits of a project aimed to reduce flood risks, and can threaten its viability if they are severe enough. In some other cases, the diverse impacts may mutually counter-balance each other, by furthermore strengthening and amplifying the social resilience. Social changes include those associated with the phenomenon known as the social construction of reality. In the case of proposed actions that involve controversy, attitudes and perceptions toward a proposed policy change are one of the variables that must be considered in determining the significance of impacts. This research entails an analysis of public authorities strategic documents developed during the last ten years in the context of strengthening Paris flood resilience. The review highlights a clear trend to encourage citizen participation and to share responsibilities with the population. This trend does not only express a political will to apply the principle of subsidiarity and decentralise risk management, it also springs from a growing awareness among public institutions of the impact that social construction of the reality can have. Hence the communication between local governments and citizens, especially a two-ways dialogue (i.e. participatory communication), has become a keystone of resilience strategies since it facilitates mutual understanding, shared goals identification and cooperation. More and more frequently flood resilience projects entail a communication strategy or focus on communication actions. However not all these project identify clear communication objectives, target audiences or monitor communication impact. Measuring communication indicators allows decision makers to compare the costs of communication actions with the economic, environmental, social, and sanitary costs of non-action. Those metrics also help to set up clear communication objectives at the beginning of a project, to evaluate and improve management capacities, to

  18. Dam pre-release as an important operation strategy in reducing flood impact in Malaysia

    Directory of Open Access Journals (Sweden)

    Hidayah Ishak Nurul

    2018-01-01

    Full Text Available The 2014 flood was reported to be one of the worst natural disaster has ever affected several states in the northern part of Peninsular Malaysia. Overwhelming rainfall was noted as one of the main factors causing such impact, which was claimed to be unprecedented to some extent. The state of Perak, which is blessed with four cascading dams had also experienced flood damage at a scale that was considered the worst in history. The rainfall received had caused the dam to reach danger level that necessitated additional discharge to be released. Safety of the dams was of great importance and such unavoidable additional discharge was allowed to avoid catastrophic failure of the dam structures. This paper discusses the dam pre-release as a significant dam management strategy in reducing flood impact. An important balance between required dam storage to be maintained and the risk element that can be afforded is the crucial factor in such enhanced operation strategy. While further possibility in developing a carefully engineered dam pre-release strategy can be explored for dam operation in Malaysia, this has already been introduced in some developed countries. Australia and South Africa are examples where pre-release has been practiced and proven to reduce flood risk. The concept involves controlling the dam lake level throughout the year, in reference to the rainfall data and the hydrological properties for the catchment area of the dams. Plentiful data analysis need to be done in contemplation of producing the optimal pre-release model. The amount of heavy rainfalls received is beyond human control but the distribution of the discharge from the dams can be further managed with the appropriate pre-release strategy.

  19. Dam pre-release as an important operation strategy in reducing flood impact in Malaysia

    Science.gov (United States)

    Hidayah Ishak, Nurul; Mustafa Hashim, Ahmad

    2018-03-01

    The 2014 flood was reported to be one of the worst natural disaster has ever affected several states in the northern part of Peninsular Malaysia. Overwhelming rainfall was noted as one of the main factors causing such impact, which was claimed to be unprecedented to some extent. The state of Perak, which is blessed with four cascading dams had also experienced flood damage at a scale that was considered the worst in history. The rainfall received had caused the dam to reach danger level that necessitated additional discharge to be released. Safety of the dams was of great importance and such unavoidable additional discharge was allowed to avoid catastrophic failure of the dam structures. This paper discusses the dam pre-release as a significant dam management strategy in reducing flood impact. An important balance between required dam storage to be maintained and the risk element that can be afforded is the crucial factor in such enhanced operation strategy. While further possibility in developing a carefully engineered dam pre-release strategy can be explored for dam operation in Malaysia, this has already been introduced in some developed countries. Australia and South Africa are examples where pre-release has been practiced and proven to reduce flood risk. The concept involves controlling the dam lake level throughout the year, in reference to the rainfall data and the hydrological properties for the catchment area of the dams. Plentiful data analysis need to be done in contemplation of producing the optimal pre-release model. The amount of heavy rainfalls received is beyond human control but the distribution of the discharge from the dams can be further managed with the appropriate pre-release strategy.

  20. An EPA pilot study characterizing fungal and bacterial populations at homes after flooding events at the Martin Peña Channel community-Puerto Rico

    Science.gov (United States)

    The overall objective of this program is to characterize fungal and bacterial populations in the MPC residences in San Juan, Puerto Rico, following flooding events. These profiles will be generated by comparing the fungal and bacterial populations in two groups of residences: hom...

  1. An operational procedure for rapid flood risk assessment in Europe

    Directory of Open Access Journals (Sweden)

    F. Dottori

    2017-07-01

    Full Text Available The development of methods for rapid flood mapping and risk assessment is a key step to increase the usefulness of flood early warning systems and is crucial for effective emergency response and flood impact mitigation. Currently, flood early warning systems rarely include real-time components to assess potential impacts generated by forecasted flood events. To overcome this limitation, this study describes the benchmarking of an operational procedure for rapid flood risk assessment based on predictions issued by the European Flood Awareness System (EFAS. Daily streamflow forecasts produced for major European river networks are translated into event-based flood hazard maps using a large map catalogue derived from high-resolution hydrodynamic simulations. Flood hazard maps are then combined with exposure and vulnerability information, and the impacts of the forecasted flood events are evaluated in terms of flood-prone areas, economic damage and affected population, infrastructures and cities.An extensive testing of the operational procedure has been carried out by analysing the catastrophic floods of May 2014 in Bosnia–Herzegovina, Croatia and Serbia. The reliability of the flood mapping methodology is tested against satellite-based and report-based flood extent data, while modelled estimates of economic damage and affected population are compared against ground-based estimations. Finally, we evaluate the skill of risk estimates derived from EFAS flood forecasts with different lead times and combinations of probabilistic forecasts. Results highlight the potential of the real-time operational procedure in helping emergency response and management.

  2. Flooding and poverty: Two interrelated social problems impacting rural development in Tsholotsho district of Matabeleland North province in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Ernest Dube

    2018-03-01

    Full Text Available Flooding and poverty are the two social problems that have coexisted within the rural communities of Tsholotsho district. As a result, both problems have negatively affected and disrupted the everyday pattern of lives of people living in the district. This study sought to highlight how the two problems combine to impact human societies. The objectives that the study sought to fulfil were to establish the impact of flooding on the development of rural communities, to analyse how poverty manifests itself in rural communities, to analyse the relationship that exists between flooding and poverty and to suggest ways for dealing with the two problems. A qualitative research approach, using interviews and observations, was used to gather data from the research participants. The study findings were that flooding impeded development through shifting of human populations, destruction of crops, shelter and livestock. Floods also affected human capital through causing injuries to members of the community. Poverty manifested itself in three ways – as a development barrier, a vulnerability amplifier and a non-discriminatory agent. The study further found that a strong relationship exists between flooding and poverty because of the fact that flooding causes or worsens poverty, whereas poverty increases flood vulnerability. The study concluded that the poor need government assistance to reconstruct shelter destroyed by floods. Furthermore, programs aimed at improving livelihoods of the poor are an indispensable imperative. This study informs policymakers and offers a methodological significance to development and disaster practitioners. It also adds to the body of literature on flooding and poverty.

  3. Hydrometeorological multi-model ensemble simulations of the 4 November 2011 flash flood event in Genoa, Italy, in the framework of the DRIHM project

    Directory of Open Access Journals (Sweden)

    A. Hally

    2015-03-01

    Full Text Available The e-Science environment developed in the framework of the EU-funded DRIHM project was used to demonstrate its ability to provide relevant, meaningful hydrometeorological forecasts. This was illustrated for the tragic case of 4 November 2011, when Genoa, Italy, was flooded as the result of heavy, convective precipitation that inundated the Bisagno catchment. The Meteorological Model Bridge (MMB, an innovative software component developed within the DRIHM project for the interoperability of meteorological and hydrological models, is a key component of the DRIHM e-Science environment. The MMB allowed three different rainfall-discharge models (DRiFt, RIBS and HBV to be driven by four mesoscale limited-area atmospheric models (WRF-NMM, WRF-ARW, Meso-NH and AROME and a downscaling algorithm (RainFARM in a seamless fashion. In addition to this multi-model configuration, some of the models were run in probabilistic mode, thus giving a comprehensive account of modelling errors and a very large amount of likely hydrometeorological scenarios (> 1500. The multi-model approach proved to be necessary because, whilst various aspects of the event were successfully simulated by different models, none of the models reproduced all of these aspects correctly. It was shown that the resulting set of simulations helped identify key atmospheric processes responsible for the large rainfall accumulations over the Bisagno basin. The DRIHM e-Science environment facilitated an evaluation of the sensitivity to atmospheric and hydrological modelling errors. This showed that both had a significant impact on predicted discharges, the former being larger than the latter. Finally, the usefulness of the set of hydrometeorological simulations was assessed from a flash flood early-warning perspective.

  4. Climate change impacts on urban wildfire and flooding policy in Idaho: a comparative policy network perspective

    Science.gov (United States)

    Lindquist, E.; Pierce, J. L.

    2013-12-01

    Numerous frameworks and models exist for understanding the dynamics of the public policy process. A policy network approach considers how and why stakeholders and interests pay attention to and engage in policy problems, such as flood control or developing resilient and fire resistant landscapes. Variables considered in this approach include what the relationships are between these stakeholders, how they influence the process and outcomes, communication patterns within and between policy networks, and how networks change as a result of new information, science, or public interest and involvement with the problem. This approach is useful in understanding the creation of natural hazards policy as new information or situations, such as projected climate change impacts, influence and disrupt the policy process and networks. Two significant natural hazard policy networks exist in the semi-arid Treasure Valley region of Southwest Idaho, which includes the capitol city of Boise and the surrounding metropolitan area. Boise is situated along the Boise River and adjacent to steep foothills; this physiographic setting makes Boise vulnerable to both wildfires at the wildland-urban interface (WUI) and flooding. Both of these natural hazards have devastated the community i