Science.gov

Sample records for 100-year flood event

  1. Erosion and Deposition Patterns of the Mississippi River as a Result of the "100-Year" Flood Event of April 2011

    NASA Astrophysics Data System (ADS)

    Meyer, D.; Magnani, M.; McIntosh, K. D.

    2011-12-01

    Due to damming in the upper Mississippi River system, rates of sedimentation on the Mississippi River have decreased by more than half since the 1930s, which has resulted in the subsidence of the historic deltaic systems. In order to counteract this trend, the US Army Corps of Engineers (USACE) have diverted most of the Mississippi River sediment flow towards the current deltaic system, although there is concern that current sediment deposition rates may not be enough. Modern land loss along the Mississippi River deltaic plain is a function of many parameters, including the sediment storage and the sediment budget of the river. These parameters are poorly constrained for most rivers. This study explores the possibility of estimating the amount of sediment mobilization during the "100-Year" flood that took place in April 2011 in the portion of the Mississippi River flowing by Memphis, Tennessee. The opportunity to acquire high resolution seismic CHIRP data along the Mississippi River immediately after the flood allows us to compare the new data with similar data acquired in September 2009 in the same part of the river, to evaluate changes sedimentary structures and in the sediment removal/deposition due to the exceptional flooding event. The data were acquired in both cases using an Edgetech SB-512i CHIRP, a 0.7 - 1.2 kHz source pulse, and were recorded to a depth of 5 - 50 m sub-bottom. The compared segments were taken along the same 20 km track of river and comparisons were drawn between them at 9 intersection points. Two main observations can be made from the preliminary analysis of the two datasets: 1) the 2011 data show evidence of widespread erosion and limited deposition. Up to 6 m of alluvium appear to have been eroded from the river bottom. Where sediments have been newly deposited, they are characterized by massive appearance and lack of internal structure; 2) the wavelengths of the sandbars imaged in the post-flood data are 1.5 - 3 times longer than those

  2. 100-Year Flood-It's All About Chance

    USGS Publications Warehouse

    Holmes, Jr., Robert R.; Dinicola, Karen

    2010-01-01

    In the 1960's, the United States government decided to use the 1-percent annual exceedance probability (AEP) flood as the basis for the National Flood Insurance Program. The 1-percent AEP flood was thought to be a fair balance between protecting the public and overly stringent regulation. Because the 1-percent AEP flood has a 1 in 100 chance of being equaled or exceeded in any 1 year, and it has an average recurrence interval of 100 years, it often is referred to as the '100-year flood'. The term '100-year flood' is part of the national lexicon, but is often a source of confusion by those not familiar with flood science and statistics. This poster is an attempt to explain the concept, probabilistic nature, and inherent uncertainties of the '100-year flood' to the layman.

  3. Technique for estimating depths of 100-year floods in Pennsylvania

    USGS Publications Warehouse

    Flippo, Herbert N., Jr.

    1990-01-01

    Techniques are developed for estimating 100-year flood depths in natural channels of unregulated Pennsylvania streams that drain less than 2,200 square miles. Equations and graphs are presented relating the depth of the 100-year flood above median stage and drainage area in five defined hydrologic areas in the State. Another graph defines the relation between drainage area and median depth of flow over the low point of riffles. Thus 100-year depths on riffles can be estimated by summing depth values derived from two simple relations.

  4. Tunguska explosion- 100 years of the event

    NASA Astrophysics Data System (ADS)

    Pteancu, Mircea; Dragan, Dorian; Dohotariu, Ionel; Mafalda; Alimpie, Laurentiu; Monea, Cristian; Diaconu, Marius; Gaina, Alex; Stanescu, Octavian

    2008-06-01

    The authors discusse the Tunguska event, the well known explosion, which has occured 100 ago in the Central Siberia near the Podkamennaia Tunguska river. A number of the books and encyclopaediaes with reference to the event are reviewed. At the same time the last 2 hypotheses ennounced by prof. Ioan Nistor (gaseus Methan pouch) and prof. Edward Drobyshevsky (2H2 +O2 solid solution) are also discussed.

  5. Technique for estimating depth of 100-year floods in Tennessee

    USGS Publications Warehouse

    Gamble, Charles R.; Lewis, James G.

    1977-01-01

    Preface: A method is presented for estimating the depth of the loo-year flood in four hydrologic areas in Tennessee. Depths at 151 gaging stations on streams that were not significantly affected by man made changes were related to basin characteristics by multiple regression techniques. Equations derived from the analysis can be used to estimate the depth of the loo-year flood if the size of the drainage basin is known.

  6. Discharge, gage height, and elevation of 100-year floods in the Hudson River basin, New York

    USGS Publications Warehouse

    Archer, Roger J.

    1978-01-01

    The flood discharge that may be expected to be equaled or exceeded on the average of once in 100 years (100-year flood) was computed by the log-Pearson Type-III frequency relation for 72 stations in the Hudson River basin. These discharges and, where available, their corresponding gage height and elevation above mean sea level are presented in tabular form. A short explanation of computation methods is included. The data are to be used as part of a federally funded study of the water resources and related land resources of the Hudson River basin. (Woodard-USGS)

  7. Flood boundaries and water-surface profile for the computed 100-year flood, Swift Creek at Afton, Wyoming, 1986

    USGS Publications Warehouse

    Rankl, James G.; Wallace, Joe C.

    1989-01-01

    Flood flows on Swift Creek near Afton, Wyoming, were analyzed. Peak discharge with an average recurrence interval of 100 years was computed and used to determine the flood boundaries and water surface profile in the study reach. The study was done in cooperation with Lincoln County and the Town of Afton to determine the extent of flooding in the Town of Afton from a 100-year flood on Swift Creek. The reach of Swift Creek considered in the analysis extends upstream from the culvert at Allred County Road No. 12-135 to the US Geological Survey streamflow-gaging station located in the Bridger National Forest , a distance of 3.2 miles. Boundaries of the 100-year flood are delineated on a map using the computed elevation of the flood at each cross section, survey data, and a 1983 aerial photograph. The computed water surface elevation for the 100-year flood was plotted at each cross section, then the lateral extent of the flood was transferred to the flood map. Boundaries between cross sections were sketched using information taken from the aerial photograph. Areas that are inundated, but not part of the active flow, are designated on the cross sections. (Lantz-PTT)

  8. Areas subject to inundation by the 100-year flood in Avra Valley, Pima County, Arizona

    USGS Publications Warehouse

    Roeske, R.H.

    1978-01-01

    Avra Valley in Pima County, Arizona, is sparsely populated and is used mainly for agriculture and cattle grazing; however, its proximity to Tucson makes it desirable for urban development. Administrators and planners concerned with future land development may use the map report to determine the approximate areas that are subject to inundation by the 100-year flood. Avra Valley is drained mainly by Brawley Wash; Blanco Wash drains the west side of the valley. Most of the natural drainage system consists of small braided channels bordered by narrow bands of dense vegetation, which cause floodwater to spread over wide areas of shallow depths. During the 100-year flood, the areas inundated by Brawley and Blanco Washes may join in several places. (Woodard-USGS)

  9. Flood risk management in the Thames Estuary looking ahead 100 years.

    PubMed

    Lavery, Sarah; Donovan, Bill

    2005-06-15

    The River Thames tidal defences have provided protection against the increasing threat of tidal flooding from the North Sea for more than 2000 years. The flood of 1953 was the catalyst for the construction of the current system of River Thames tidal defences, which includes the Thames Barrier, and has provided one of the best standards of flood defence in the UK for over 20 years. Substantial growth is planned through "Thames Gateway", a regeneration initiative of the United Kingdom government. These new developments will fundamentally change the developed footprint in the Thames Estuary flood-plain, and will be in place for at least the next 100 years. This presents a challenge of planning future defence against a background of uncertainty over climate and other environmental change, while ensuring that correct decisions are made concerning the nature and location of new building in the tidal flood-plain. Through its "Thames Estuary 2100" project, the Environment Agency is developing a long-term strategy for flood risk management in the estuary. Implementation of major construction works on the River Thames could commence from around 2015. Alternatively, it may be decided that minimum works are undertaken to provide security and major investment is delayed until uncertainties over climate change have abated. Whatever long-term option is chosen, this must be preceded by a period of collaboration with the Thames Gateway developments to ensure appropriate and sustainable flood defences are incorporated in new riverside construction. PMID:16191661

  10. Evaluating the 100 year floodplain as an indicator of flood risk in low-lying coastal watersheds

    NASA Astrophysics Data System (ADS)

    Sebastian, A.; Brody, S.; Bedient, P. B.

    2013-12-01

    The Gulf of Mexico is the fastest growing region in the United States. Since 1960, the number of housing units built in the low-lying coastal counties has increased by 246%. The region experiences some of the most intense rainfall events in the country and coastal watersheds are prone to severe flooding characterized by wide floodplains and ponding. This flooding is further exacerbated as urban development encroaches on existing streams and waterways. While the 100 year floodplain should play an important role in our ability to develop disaster resilient communities, recent research has indicated that existing floodplain delineations are a poor indicator of actual flood losses in low-lying coastal regions. Between 2001 and 2005, more than 30% of insurance claims made to FEMA in the Gulf Coast region were outside of the 100 year floodplain and residential losses amounted to more than $19.3 billion. As population density and investments in this region continue to increase, addressing flood risk in coastal communities should become a priority for engineers, urban planners, and decision makers. This study compares the effectiveness of 1-D and a 2-D modeling approaches to spatially capture flood claims from historical events. Initial results indicate that 2-D models perform much better in coastal environments and may serve better for floodplain modeling helping to prevent unintended losses. The results of this study encourage a shift towards better engineering practices using existing 2-D models in order to protect resources and provide guidance for urban development in low-lying coastal regions.

  11. A technique for estimating heights reached by the 100-year flood on unregulated, nontidal streams in North Carolina

    USGS Publications Warehouse

    Coble, R.W.

    1979-01-01

    A method for estimating the heights reached by floods having a recurrence interval of 100 years is defined for nontidal streams with unregulated flows in North Carolina. The flood heights are the vertical distance between stream stage at median discharge (50 percent duration) and the 100-year flood stage and are defined for streams draining areas between 1 and 10,000 square miles for each of the three physiographic areas in the State. An illustrated example of how the method can be used in conjunction with topographic maps to estimate flood heights and delineate inundated areas by interpolation is given.

  12. FLOOD EVENT MAPPING IMAGES

    EPA Science Inventory

    OSEI flood products (FLD) include multichannel color composite imagery and single-channel grayscale imagery of enlarged river areas or increased sediment flow. Typically, these events are displayed by comparison to imagery taken when flooding was not occurring.

  13. Comparison of the 2-, 25-, and 100-year recurrence interval floods computed from observed data with the 1995 urban flood-frequency estimating equations for Georgia

    USGS Publications Warehouse

    Inman, Ernest J.

    1997-01-01

    Flood-frequency relations were computed for 28 urban stations, for 2-, 25-, and 100-year recurrence interval floods and the computations were compared to corresponding recurrence interval floods computed from the estimating equations from a 1995 investigation. Two stations were excluded from further comparisons or analyses because neither station had a significant flood during the period of observed record. The comparisons, based on the student's t-test statistics at the 0.05 level of significance, indicate that the mean residuals of the 25- and 100-year floods were negatively biased by 26.2 percent and 31.6 percent, respectively, at the 26 stations. However, the mean residuals of the 2-year floods were 2.5 percent lower than the mean of the 2-year floods computed from the equations, and were not significantly biased. The reason for this negative bias is that the period of observed record at the 26 stations was a relatively dry period. At 25 of the 26 stations, the two highest simulated peaks used to develop the estimating equations occurred many years before the observed record began. However, no attempt was made to adjust the estimating equations because higher peaks could occur after the period of observed record and an adjustment to the equations would cause an underestimation of design floods.

  14. Determination of the 100-year flood plain on Upper Three Runs and selected tributaries, and the Savannah River at the Savannah River site, South Carolina, 1995

    USGS Publications Warehouse

    Lanier, T.H.

    1996-01-01

    The 100-year flood plain was determined for Upper Three Runs, its tributaries, and the part of the Savannah River that borders the Savannah River Site. The results are provided in tabular and graphical formats. The 100-year flood-plain maps and flood profiles provide water-resource managers of the Savannah River Site with a technical basis for making flood-plain management decisions that could minimize future flood problems and provide a basis for designing and constructing drainage structures along roadways. A hydrologic analysis was made to estimate the 100-year recurrence- interval flow for Upper Three Runs and its tributaries. The analysis showed that the well-drained, sandy soils in the head waters of Upper Three Runs reduce the high flows in the stream; therefore, the South Carolina upper Coastal Plain regional-rural-regression equation does not apply for Upper Three Runs. Conse- quently, a relation was established for 100-year recurrence-interval flow and drainage area using streamflow data from U.S. Geological Survey gaging stations on Upper Three Runs. This relation was used to compute 100-year recurrence-interval flows at selected points along the stream. The regional regression equations were applicable for the tributaries to Upper Three Runs, because the soil types in the drainage basins of the tributaries resemble those normally occurring in upper Coastal Plain basins. This was verified by analysis of the flood-frequency data collected from U.S. Geological Survey gaging station 02197342 on Fourmile Branch. Cross sections were surveyed throughout each reach, and other pertinent data such as flow resistance and land-use were col- lected. The surveyed cross sections and computed 100-year recurrence-interval flows were used in a step-backwater model to compute the 100-year flood profile for Upper Three Runs and its tributaries. The profiles were used to delineate the 100-year flood plain on topographic maps. The Savannah River forms the southwestern border

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Flow and sediment processes in a cutoff meander of the Danube Delta during 100-year recurrent flood

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, L.; Le Coz, J.; Provansal, M.; Dutu, F.

    2009-04-01

    River training operations, such as meander cutoff, initiated for navigational purposes often lead to dramatic changes in the streamwise profiles (Hooke, 1986, Kesel, 2003; Kiss et al., 2007). Meander correction affects both the hydraulic and morphodynamical behavior of the modified branches that sedimentation occurs in time, while newly built canals usually experience degradation (Jugaru et. al, 2006). This study reports and analyzes new data on the hydrological and sedimentary processes at work during a morphogenic flood in a large modified meander (the Mahmudia meander) of the St. George branch, the southern branch of the Danube Delta. The 100-year recurrent flood that occurred in 2006 offered an exceptional opportunity for scanning different cross sections of the Mahmudia meander system by means of the emerging Doppler profiler (aDcp) technology in order to analyze the impact on sedimentation and dynamic processes in the study area. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel (Popa, 1997). During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution

  17. The History of Parenting Practices: An Overview! Events, Policies and Theories That Have Influenced Parenting Practices over the Last 100 Years. [Videotape and Worksheets].

    ERIC Educational Resources Information Center

    1999

    Noting that parenting is a learned experience and that the source of information on parenting has changed considerably over the last 100 years, this videotape examines the history of parent education over the past 100 years, highlighting events influencing family life, policies and legislation to assist families, and parenting theories for each…

  18. Remote sensing of suspended sediment discharge into the western Gulf of Maine during the April 1987 100-year flood

    USGS Publications Warehouse

    Stumpf, R.P.; Goldschmidt, P.M.

    1992-01-01

    The suspended sediment discharge during this event was identified using NOAA-9 and NOAA-10 Advanced Very High Resolution Radiometer (AVHRR) data from March 29 to April 14. The sediment plumes showed a westward movement upon reaching the Gulf of Maine. 105 metric tons of fine-grained sediments were carried onto the continental shelf in the largest plume, that from the Kennebec-Androscoggin river system. -from Authors

  19. Aquatic chemistry of flood events

    NASA Astrophysics Data System (ADS)

    Klavins, Maris; Rodinov, Valery

    2015-04-01

    During flood events a major discharge of water and dissolved substances happens. However flood waters very much differs from water composition during low-water events. Aquatic chemistry of flood waters also is of importance at the calculation of loadings as well as they might have major impact on water quality in receiving water bodies (lakes, coastal waters and seas). Further flood regime of rivers is subjected to changes due to climate change and growing impact of human activities. The aim of this study is to analyse water chemical composition changes during flood events in respect to low water periods, character of high-water events and characteristics of the corresponding basin. Within this study, the concentrations of major dissolved substances in the major rivers of Latvia have been studied using monitoring data as well as field studies during high water/ low water events. As territories of studies flows of substances in river basins/subbasins with different land-use character and different anthropogenic impacts has been studied to calculate export values depending on the land-use character. Impact of relations between dissolved substances and relations in respect to budgets has been calculated. The dynamics of DOC, nutrient and major dissolved substance flows depending on landuse pattern and soil properties in Latvia has been described, including emissions by industrial and agricultural production. In these changes evidently climate change signals can be identified. The water chemistry of a large number of rivers during flood events has been determined and the possible impact of water chemical composition on DOC and nutrient flows has been evaluated. Long-term changes (1977-2013) of concentrations of dissolved substances do not follow linear trends but rather show oscillating patterns, indicating impact of natural factors, e.g. changing hydrological and climatic conditions. There is a positive correlation between content of inert dissolved substances and

  20. Flood basalts and extinction events

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. The flood event explorer - a web based framework for rapid flood event analysis

    NASA Astrophysics Data System (ADS)

    Schröter, Kai; Lüdtke, Stefan; Kreibich, Heidi; Merz, Bruno

    2015-04-01

    Flood disaster management, recovery and reconstruction planning benefit from rapid evaluations of flood events and expected impacts. The near real time in-depth analysis of flood causes and key drivers for flood impacts requires a close monitoring and documentation of hydro-meteorological and socio-economic factors. Within the CEDIM's Rapid Flood Event Analysis project a flood event analysis system is developed which enables the near real-time evaluation of large scale floods in Germany. The analysis system includes functionalities to compile event related hydro-meteorological data, to evaluate the current flood situation, to assess hazard intensity and to estimate flood damage to residential buildings. A German flood event database is under development, which contains various hydro-meteorological information - in the future also impact information -for all large-scale floods since 1950. This data base comprises data on historic flood events which allow the classification of ongoing floods in terms of triggering processes and pre-conditions, critical controls and drivers for flood losses. The flood event analysis system has been implemented in a database system which automatically retrieves and stores data from more than 100 online discharge gauges on a daily basis. The current discharge observations are evaluated in a long term context in terms of flood frequency analysis. The web-based frontend visualizes the current flood situation in comparison to any past flood from the flood catalogue. The regional flood data base for Germany contains hydro-meteorological data and aggregated severity indices for a set of 76 historic large-scale flood events in Germany. This data base has been used to evaluate the key drivers for the flood in June 2013.

  3. After the flood is before the next flood - post event review of the Central European Floods of June 2013. Insights, recommendations and next steps for future flood prevention

    NASA Astrophysics Data System (ADS)

    Szoenyi, Michael; Mechler, Reinhard; McCallum, Ian

    2015-04-01

    In early June 2013, severe flooding hit Central and Eastern Europe, causing extensive damage, in particular along the Danube and Elbe main watersheds. The situation was particularly severe in Eastern Germany, Austria, Hungary and the Czech Republic. Based on the Post Event Review Capability (PERC) approach, developed by Zurich Insurance's Flood Resilience Program to provide independent review of large flood events, we examine what has worked well (best practice) and opportunities for further improvement. The PERC overall aims to thoroughly examine aspects of flood resilience, flood risk management and catastrophe intervention in order to help build back better after events and learn for future events. As our research from post event analyses shows a lot of losses are in fact avoidable by taking the right measures pre-event and these measures are economically - efficient with a return of 4 Euro on losses saved for every Euro invested in prevention on average (Wharton/IIASA flood resilience alliance paper on cost benefit analysis, Mechler et al. 2014) and up to 10 Euros for certain countries. For the 2013 flood events we provide analysis on the following aspects and in general identify a number of factors that worked in terms of reducing the loss and risk burden. 1. Understanding risk factors of the Central European Floods 2013 We review the precursors leading up to the floods in June, with an extremely wet May 2013 and an atypical V-b weather pattern that brought immense precipitation in a very short period to the watersheds of Elbe, Donau and partially the Rhine in the D-A-CH countries and researched what happened during the flood and why. Key questions we asked revolve around which protection and risk reduction approaches worked well and which did not, and why. 2. Insights and recommendations from the post event review The PERC identified a number of risk factors, which need attention if risk is to be reduced over time. • Yet another "100-year flood" - risk

  4. Drivers of flood damage on event level

    NASA Astrophysics Data System (ADS)

    Kreibich, Heidi

    2016-04-01

    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 example are the 2002 and 2013 floods in the Elbe and Danube catchments in Germany. The 2002 flood caused the highest economic damage (EUR 11600 million) due to a natural hazard event in Germany. Damage was so high due to extreme flood hazard triggered by extreme precipitation and a high number of resulting dyke breaches. Additionally, exposure hotspots like the city of Dresden at the Elbe river as well as some smaller municipalities at the river Mulde (e.g. Grimma, Eilenburg, Bitterfeld, Dessau) were severely impacted. However, affected parties and authorities learned from the extreme flood in 2002, and many governmental flood risk programs and initiatives were launched. Considerable improvements since 2002 occurred on many levels that deal with flood risk reduction and disaster response, in particular in 1) increased flood prevention by improved spatial planning, 2) an increased number of property-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

  5. Tuskegee: 100 Years Later.

    ERIC Educational Resources Information Center

    Higgins, Renelda

    1981-01-01

    Reviews the history and accomplishments of Tuskegee Institute over the past 100 years. Highlights the role played by Booker T. Washington, and W. E. B. DuBois; discusses the career of the school's retiring president, Luther Foster. Provides information on the new president, Dr. Benjamin Payton, and discusses future directions for the college. (APM)

  6. Pan-European catalogue of flood events

    NASA Astrophysics Data System (ADS)

    Parajka, Juraj; Mangini, Walter; Viglione, Alberto; Hundecha, Yeshewatesfa; Ceola, Serena

    2016-04-01

    There have been numerous extreme flood events observed in Europe in the past years. One of the way to improve our understanding about causing flood generation mechanisms is to analyse spatial and temporal variability of a large number of flood events. The aim of this study is to present a pan-European catalogue of flood events developed within the SWITCH-ON EU Project. The flood events are identified from daily discharge observations at 1315 stations listed in Global Runoff Data Centre database. The average length of discharge time-series for selected stations is 54 years. For each event, basin boundary and additional hydrological and weather characteristics are extracted. Hydrological characteristics are extracted from the pan-European HYPE model simulations. Precipitation, together with the corresponding proportions of rainfall and snowfall, snowmelt, and evapotranspiration are computed as total amounts between the event start date and event peak date. Soil moisture, soil moisture deficit, and basin accumulated snow water equivalent are computed for the event start date. Weather characteristics are derived from the weather circulation pattern catalogue developed within COST 733 Project. The results are generated in an open data access and tools framework which allows reproduction and extension of results to other regions. More information about the analysis and project are available at: http://www.water-switch-on.eu/lab.html.

  7. Loss of life in flood events

    NASA Astrophysics Data System (ADS)

    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.

  8. Coastal flood events in the Maldives

    NASA Astrophysics Data System (ADS)

    Wadey, Matthew; Nicholls, Robert J.; Brown, Sally; Haigh, Ivan; McCabe, Maurice

    2016-04-01

    The Maldives are low lying (mostly < 1m above mean sea level) coral islands in the Indian Ocean that are threatened by coastal flooding and sea-level rise (SLR). Protection of low-lying islands and climate change adaptation is optimum where physical systems are understood, yet there is a lack of basic physical information and data about coastal flooding and its causes in the Maldives, which this study addresses. We primarily focus upon an artificial island (Hulhumalé) built 2m above mean sea level to relieve population pressure on the nearby capital Malé. Records show that two severe coastal flood events affected the islands (although not Hulhumalé) in recent decades during April 1987 and May 2007. The primary data source was time series of still water levels at 3 tide gauges which span over 800km north-south across the archipelago (covering 1987-present). Wave conditions (2006-2014) were extracted from a model hindcast, since observational records are not available. The sea-level and wave data were analysed in relation to land heights and SLR, and by applying an overtopping model. This illustrated how the fundamental cause of the 1987 and 2007 floods was south-westerly swell events with wave periods of up to 20s combined with spring tides. Overtopping simulations based upon present-day extremes and projected SLR scenarios, suggest that a relatively small variation of background still water level can drastically increase overtopping and worsen flood impacts. This is partly due to the flatness of the island, although also highlights the sensitivity of flood risk in these islands to mean SLR. In this context of extreme events, projected SLR, and population growth, we briefly discuss adaptation in the context of socio-economic and environmental change. Recommendations are made for future data collection and monitoring.

  9. Understanding Extreme Spanish Coastal Flood Events

    NASA Astrophysics Data System (ADS)

    Diez, J. Javier; Esteban, M. Dolores; Silvestre, J. Manuel

    2013-04-01

    The Santa Irene flood event, at the end of October 1982, is one of the most dramatically widely reported flood events in Spain. Its renown is mainly due to the collapse of the Tous dam, but its main message is to be the paradigm of the incidence of the maritime/littoral weather and its temporal sea level rise by storm surge accompanying rain process on the coastal plains inland floods. Looking at damages the presentation analyzes the adapted measures from the point of view of the aims of the FP7 SMARTeST Project related to the Flood Resilience improvement in urban areas through looking for Technologies, Systems and Tools an appropriate "road to de market". The event was due to the meteorological phenomenon known as "gota fría" (cold drop), a relatively frequent and intense rainy phenomenon affecting one or more basins on the Iberian Peninsula, particularly on the Spanish east to southeast inlands and coasts. There are some circumstances that can easily come together to unleash the cold drop there: cold and dry polar air masses coming onto the whole Iberian Peninsula and the north of Africa, high sea water temperatures, and low atmospheric pressure (cyclone) areas in the western Mediterranean basin; these circumstances are quite common during the autumn season there, and, as it happens, in other places around the world (East/Southeast Africa). Their occurrence, however shows a great space-temporal variability (in a similar way to hurricanes, on Caribbean and western North-Atlantic areas, or to typhoons do). As a matter of fact, all of these equivalent though different phenomena may have different magnitude each time. An overview of the very main events since 11th century in the East to Southeast areas in Spain is shown in the presentation, looking for relation with climatic conditions and Climate changes on one hand, and with geomorphologic and geotechnical conditions on the other It also describes the results of a detailed analysis and reflection about this cold

  10. NETL: The First 100 Years

    SciTech Connect

    2015-07-21

    The National Energy Technology Laboratory celebrates 100 years of innovative energy technology development. NETL has been a leader in energy technology development. This video takes a look back at the many accomplishments over the past 100 years. These advances benefit the American people, enhance our nation's energy security and protect our natural resources.

  11. 100 years of Lewy pathology.

    PubMed

    Goedert, Michel; Spillantini, Maria Grazia; Del Tredici, Kelly; Braak, Heiko

    2013-01-01

    In 1817, James Parkinson described the symptoms of the shaking palsy, a disease that was subsequently defined in greater detail, and named after Parkinson, by Jean-Martin Charcot. Parkinson expected that the publication of his monograph would lead to a rapid elucidation of the anatomical substrate of the shaking palsy; in the event, this process took almost a century. In 1912, Fritz Heinrich Lewy identified the protein aggregates that define Parkinson disease (PD) in some brain regions outside the substantia nigra. In 1919, Konstantin Nikolaevich Tretiakoff found similar aggregates in the substantia nigra and named them after Lewy. In the 1990s, α-synuclein was identified as the main constituent of the Lewy pathology, and its aggregation was shown to be central to PD, dementia with Lewy bodies, and multiple system atrophy. In 2003, a staging scheme for idiopathic PD was introduced, according to which α-synuclein pathology originates in the dorsal motor nucleus of the vagal nerve and progresses from there to other brain regions, including the substantia nigra. In this article, we review the relevance of Lewy's discovery 100 years ago for the current understanding of PD and related disorders. PMID:23183883

  12. A Dendrochronological Analysis of Mississippi River Flood Events

    NASA Astrophysics Data System (ADS)

    Therrell, M. D.; Bialecki, M. B.; Peters, C.

    2012-12-01

    We used a novel tree-ring record of anatomically anomalous "flood rings" preserved in Oak (Quercus sp.) trees growing downstream of the Mississippi and Ohio River confluence to identify spring (MAM) flood events on the lower Mississippi River from C.E. 1694-2009. Our chronology includes virtually all of the observed high-magnitude spring floods of the 20th century as well as similar flood events in prior centuries occurring on the Mississippi River adjacent to the Birds Point-New Madrid Floodway. A response index analysis indicates that over half of the floods identified caused anatomical injury to well over 50% of the sampled trees and many of the greatest flood events are recorded by more than 80% of the trees at the site including 100% of the trees in the great flood of 1927. Twenty-five of the 40 floods identified as flood rings in the tree-ring record, occur during the instrumental observation period at New Madrid, Missouri (1879-2009), and comparison of the response index with average daily river stage height values indicates that the flood ring record can explain significant portions of the variance in both stage height (30%) and number of days in flood (40%) during spring flood events. The flood ring record also suggests that high-magnitude spring flooding is episodic and linked to basin-scale pluvial events driven by decadal-scale variability of the Pacific/North American pattern (PNA). This relationship suggests that the tree-ring record of flooding may also be used as a proxy record of atmospheric variability related to the PNA and related large-scale forcing.

  13. Sensitivity of flood events to global climate change

    NASA Astrophysics Data System (ADS)

    Panagoulia, Dionysia; Dimou, George

    1997-04-01

    The sensitivity of Acheloos river flood events at the outfall of the mountainous Mesochora catchment in Central Greece was analysed under various scenarios of global climate change. The climate change pattern was simulated through a set of hypothetical and monthly GISS (Goddard Institute for Space Studies) scenarios of temperature increase coupled with precipitation changes. The daily outflow of the catchment, which is dominated by spring snowmelt runoff, was simulated by the coupling of snowmelt and soil moisture accounting models of the US National Weather Service River Forecast System. Two threshold levels were used to define a flood day—the double and triple long-term mean daily streamflow—and the flood parameters (occurrences, duration, magnitude, etc.) for these cases were determined. Despite the complicated response of flood events to temperature increase and threshold, both hypothetical and monthly GISS representations of climate change resulted in more and longer flood events for climates with increased precipitation. All climates yielded larger flood volumes and greater mean values of flood peaks with respect to precipitation increase. The lower threshold resulted in more and longer flood occurrences, as well as smaller flood volumes and peaks than those of the upper one. The combination of higher and frequent flood events could lead to greater risks of inudation and possible damage to structures. Furthermore, the winter swelling of the streamflow could increase erosion of the river bed and banks and hence modify the river profile.

  14. [100 years' of clinical electrocardiography].

    PubMed

    Bergovec, Mijo

    2003-01-01

    In 1903 Willem Einthoven published in Pflügers Arch his classic article on the investigation of human electrocardiogram by his string galvanometer. Many historians of medicine, Einthoven also marked that publication as the beginning of clinical electrocardiography. Many investigators like Galvani, Manteucci, Kölliker, Müller, Lipmann, Waller, Ader, Einthoven, Lewis, Wilson and others participated in creation and development of electrocardiogram. From that time electrocardiogram quickly became, and has remained the most essential diagnostic laboratory tool in investigation of heart diseases. The aim of this article is to remind us of the beginning of this part of cardiology 100 years ago. PMID:15209030

  15. A climate emulator for coastal flooding events

    NASA Astrophysics Data System (ADS)

    Rueda Zamora, A. C.; Méndez Incera, F. J.; Camus, P.; Tomas, A.

    2014-12-01

    The evaluation of coastal flooding requires the definition of the multivariate marine climate conditions (wave height, wave period, wave direction, wind, surge levels). Historical reanalysis databases are a valuable information source. However, the limited time period covered implies uncertainty in the statistical characterization of extremes. Besides, downscaling is needed to extend data to climate change scenarios or long-term historical periods, or even to understand the interannual variability. A statistical downscaling approach is adopted due to its low computational cost. The relationship between large-scale atmospheric variables (predictor) and local marine climate variables (predictand) is established by means of a physical division of the predictand based on weather types. The multivariate dependence structure of the predictand (extreme events) is introduced linking the independent marginal distributions of the variables by a probabilistic copula regression. Therefore, the climate emulator is a stochastic hybrid model with the following steps: 1) Collecting historical data for the predictor (atmospheric variables) and predictand (sea state parameters, storm-surge); 2) Predictor definition, i.e. using ESTELA method in the case of wave generation characteristics (Pérez et al., 2014a); 3) Defining the most appropriate statistical model (distribution modeling based on weather-type); 4) Stochastic simulation of the present climate; 5) Marine climate downscaling under climate change scenarios (selecting the best GCMs from CMIP5, Pérez et al., 2014b). References: Perez, J., Menéndez, M., Méndez, F.J., Losada, I.J. (2014a). Evaluating the performance of CMIP3 and CMIP5 global climate models over the north-east Atlantic region, Climate Dynamics, DOI 10.1007/s00382-014-2078-8. Perez, J., Menéndez, M., Méndez, F.J., Losada, I.J. (2014b) ESTELA: A method for evaluating the source and travel-time of the wave energy reaching a local area. Ocean Dynamics, DOI 10

  16. Analysis of large Danube flood events at Vienna since 1700

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea; Blöschl, Günter; Hohensinner, Severin; Perdigao, Rui

    2014-05-01

    Whereas Danube water level measurements are available in Vienna from 1820 onwards, documentary evidence plays a significant role in the long-term understanding of Danube hydrological processes. Based on contemporary documentary evidence and early instrumental measurements, in the present paper we aim to provide an overview and a hydrological analysis of major Danube flood events, and the changes occurred in flood behaviour in Vienna in the last 300 years. Historical flood events are discussed and analysed according to types, seasonality, frequency and magnitude. Concerning historical flood events we apply a classification of five-scaled indices that considers height, magnitude, length and impacts. The rich data coverage in Vienna, both in terms of documentary evidence and early instrumental measurements, provide us with the possibility to create a relatively long overlap between documentary evidence and instrumental measurements. This makes possible to evaluate and, to some extent, improve the index reconstruction. While detecting causes of changes in flood regime, we aim to provide an overview on the atmospheric background through some characteristic examples, selected great flood events (e.g. 1787). Moreover, we also seek for the answer for such questions as in what way early (pre-instrumental period) human impact such as water regulations and urban development changed flood behaviour in the town, and how much it might have an impact on flood classification.

  17. A study of the flood events in Cyprus

    NASA Astrophysics Data System (ADS)

    Savvidou, K.; Nicolaides, K. A.; Michaelides, S. C.; Orphanou, A.; Charalambous, M.; Adamou, S.

    2008-07-01

    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.

  18. Modelling long-term sediment deposition in a river floodplain during continues flood events

    NASA Astrophysics Data System (ADS)

    Guan, Mingfu; Ahilan, Sangaralingam; Wright, Nigel; Sleigh, P. Andrew

    2015-04-01

    River floodplains act as a form of storage during high discharges in a river. As a floodplain generally has a lower energy environment, sediment aggradation commonly occurs over the period of time, which will reduce the overall storage capacity of the floodplain. Also, in a river system sediments are generally considered as the carrier of pesticides and metal contamination from the upstream catchment. Hence, studying sediment deposition in a floodplain is not only helpful for local flood risk assessment, but also can improve our understanding of the dispersion of contaminants associated with the transfer of sediment between a river and its floodplain. This study adopts a recently updated two-dimensional hydro-morphodynamic model based on the full shallow water equations to model a long-term spatial migration of Johnson Creek, Portland, Oregon and its floodplain. The 500-year, 100-year, 50-year, 10-year, as well as the recorded flood events during 1941-2014 were simulated. Suspended load with three grain-sizes was transported to the river along with the floods. The results indicate that about 30 - 45% of total sediment load is deposited in the floodplain for the studied return period floods. The spatial distribution and amount of short and long-term sediment deposition on the floodplain is demonstrated, and the resulting potential loss of flood storage capacity is analysed and discussed.

  19. Characterisation of flood events in Switzerland based on weather patterns

    NASA Astrophysics Data System (ADS)

    Froidevaux, P.; Martius, O.; Weingartner, R.

    2012-04-01

    It is important to learn more about flood triggering weather patterns in Switzerland for two reasons: (i) projections of flood frequencies in a warmer climate are strongly limited by the ability of climate models to represent the complex small-scale processes associated with typical flood triggers like heavy precipitation and snow melt. Information about flood triggering weather situations can be used in a more indirect approach to estimate changes in future flood frequencies. (ii) Flood frequencies in Switzerland show strong decadal variability suggesting that decadal variations in the synoptic atmospheric flow might influence flood probabilities (Schmocker-Fackel and Naef, 2010). However relations with temperature trends or the North Atlantic Oscillation are complex and ambiguous and Schmocker-Fackel and Naef (2010) expressed the need for a better understanding of the synoptic-scale atmospheric flood triggers. A detailed analysis of the weather patterns that trigger flood events in Switzerland is a challenge (i) due to the complex topography (Jura mountains, Swiss Plateau and Alps) that affects both the precipitation and the run-off and (ii) due to the broad range of hydrological regimes. We account for the second factor by using existing hydrological classifications of the studied flood events (e.g. rain on snow, showers versus frontal precipitation, combination of different factors, see Diezig and Weingartner, 2007 and Helbling et al., 2006). We perform a meteorological characterization of annual flood events in the last 40 years for a selection of mesoscale catchments in Switzerland. The characterization is done separately for each hydrological regime and for different topographical regions and consists in two steps: (i) we use operational weather classifications of MeteoSwiss to describe the typical flood-associated weather regimes and (ii) we identify typical flood-related atmospheric characteristics by using the ERAinterim reanalysis dataset and a dense

  20. Detection of flood events in hydrological discharge time series

    NASA Astrophysics Data System (ADS)

    Seibert, S. P.; Ehret, U.

    2012-04-01

    The shortcomings of mean-squared-error (MSE) based distance metrics are well known (Beran 1999, Schaeffli & Gupta 2007) and the development of novel distance metrics (Pappenberger & Beven 2004, Ehret & Zehe 2011) and multi-criteria-approaches enjoy increasing popularity (Reusser 2009, Gupta et al. 2009). Nevertheless, the hydrological community still lacks metrics which identify and thus, allow signature based evaluations of hydrological discharge time series. Signature based information/evaluations are required wherever specific time series features, such as flood events, are of special concern. Calculation of event based runoff coefficients or precise knowledge on flood event characteristics (like onset or duration of rising limp or the volume of falling limp, etc.) are possible applications. The same applies for flood forecasting/simulation models. Directly comparing simulated and observed flood event features may reveal thorough insights into model dynamics. Compared to continuous space-and-time-aggregated distance metrics, event based evaluations may provide answers like the distributions of event characteristics or the percentage of the events which were actually reproduced by a hydrological model. It also may help to provide information on the simulation accuracy of small, medium and/or large events in terms of timing and magnitude. However, the number of approaches which expose time series features is small and their usage is limited to very specific questions (Merz & Blöschl 2009, Norbiato et al. 2009). We believe this is due to the following reasons: i) a generally accepted definition of the signature of interest is missing or difficult to obtain (in our case: what makes a flood event a flood event?) and/or ii) it is difficult to translate such a definition into a equation or (graphical) procedure which exposes the feature of interest in the discharge time series. We reviewed approaches which detect event starts and/or ends in hydrological discharge time

  1. Special challenges in assessing and mapping flood risk following a flood-debris flow event

    NASA Astrophysics Data System (ADS)

    Aggett, Graeme

    2016-04-01

    Severe rainfall along the Colorado front range in 2013 delivered flood and debris flows to many mountain communities, causing millions of dollars of damage as well as taking several lives. Phase changes in clear-hyperconcentrated-debris flows during the event created challenges in recreating the hydrology post-flood and in estimating and mapping new regulatory floodplains to support ongoing flood recovery efforts. This presentation highlights approaches used to overcome these challenges and to adequately represent the different processes and their uncertainties in updated flood hazard and risk assessments. It also considers the need to educate and involve the community in this process.

  2. Geomorphology and Mapping of Canyon Lake Gorge from Flood Events

    NASA Astrophysics Data System (ADS)

    Gunawan, A. P.

    2015-12-01

    A large volume of runoff causes flood that exceed the capacity of flood control reservoir. Canyon Lake Gorge, Canyon Lake, TX was formed as a result of a major erosional event in 2002. A low-pressure system combined with a flow of tropical air hit over central Texas causing precipitation, recent flooding in 2015 has changed the structure of the channel. Here, channel changes in the canyon are evaluated using hydrologic conductivity, ground penetrating radar (GPR), and photogrammetry. Mapping and field reconnaissance will be used to map out changes over the years of when the flood had occurred in the past (1998, 2002, and 2015) as well as to study the flood surrounding Canyon Lake Gorge and Guadalupe River. A demographic survey will be used to analyzed the damage that was caused by the flood and compare the severity of the event. The justification for this is that the Canyon Lake Gorge have a unique formation, geologic time scale before and after the flood has changed. The recent flood in 2015 gives an opportunity to study the changes that is currently occurring.

  3. Historical hydrology and database on flood events (Apulia, southern Italy)

    NASA Astrophysics Data System (ADS)

    Lonigro, Teresa; Basso, Alessia; Gentile, Francesco; Polemio, Maurizio

    2014-05-01

    Historical data about floods represent an important tool for the comprehension of the hydrological processes, the estimation of hazard scenarios as a basis for Civil Protection purposes, as a basis of the rational land use management, especially in karstic areas, where time series of river flows are not available and the river drainage is rare. The research shows the importance of the improvement of existing flood database with an historical approach, finalized to collect past or historical floods event, in order to better assess the occurrence trend of floods, in the case for the Apulian region (south Italy). The main source of records of flood events for Apulia was the AVI (the acronym means Italian damaged areas) database, an existing Italian database that collects data concerning damaging floods from 1918 to 1996. The database was expanded consulting newspapers, publications, and technical reports from 1996 to 2006. In order to expand the temporal range further data were collected searching in the archives of regional libraries. About 700 useful news from 17 different local newspapers were found from 1876 to 1951. From a critical analysis of the 700 news collected since 1876 to 1952 only 437 were useful for the implementation of the Apulia database. The screening of these news showed the occurrence of about 122 flood events in the entire region. The district of Bari, the regional main town, represents the area in which the great number of events occurred; the historical analysis confirms this area as flood-prone. There is an overlapping period (from 1918 to 1952) between old AVI database and new historical dataset obtained by newspapers. With regard to this period, the historical research has highlighted new flood events not reported in the existing AVI database and it also allowed to add more details to the events already recorded. This study shows that the database is a dynamic instrument, which allows a continuous implementation of data, even in real time

  4. Flooding in river mouths: human caused or natural events? Five centuries of flooding events in the SW Netherlands, 1500-2000

    NASA Astrophysics Data System (ADS)

    de Kraker, A. M. J.

    2015-06-01

    This paper looks into flood events of the past 500 years in the SW Netherlands, addressing the issue of what kind of flooding events have occurred and which ones have mainly natural causes and which ones are predominantly human induced. The flood events are classified into two major categories: (a) flood events that were caused during storm surges and (b) flood events which happened during warfare. From both categories a selection of flood events has been made. Each flood event is discussed in terms of time, location, extent of the flooded area and specific conditions. Among these conditions, specific weather circumstances and how long they lasted, the highest water levels reached and dike maintenance are discussed as far as flood events caused during storm surges are concerned. Flood events during warfare as both offensive and defensive strategies are relevant; the paper demonstrates that although the strategic flood events obviously were man-made, the natural feature, being the use of fresh water or sea water, of these events also played a major role. Flood events caused during storm surge may have an obvious natural cause, but the extent of the flooding and damage it caused was largely determined by man.

  5. Flooding in river mouths: human caused or natural events? Five centuries of flooding events in the SW Netherlands, 1500-2000

    NASA Astrophysics Data System (ADS)

    de Kraker, A. M. J.

    2015-01-01

    This paper looks into the flooding events of the past 500 years in the SW Netherlands addressing the issue what kind of flooding events have occurred and which ones have mainly natural causes and which ones are predominantly human induced. The flooding events are classified into two major categories: (a) flooding events that were caused during storm surges and (b) flooding events which happened during war fare. From both categories a selection of flooding events has been made. Each flooding event is discussed in terms time, location, extent of the flooded area and specific conditions. Among these conditions specific weather circumstances and how long they lasted, the highest water levels reached and dike maintenance are discussed as far as flooding events caused during storm surges are concerned. About the flooding events during war fare, offensive and defensive strategies are relevant. The paper demonstrates that although the strategic flooding events obviously were man-made, the natural feature, being the use of fresh water or sea water, of these events also played a major role. Flooding events caused during storm surge may have an obvious natural cause, but the extent of the flooding and damage it caused were largely determined by man.

  6. Preliminary results from two international pluvial flood event studies

    NASA Astrophysics Data System (ADS)

    Roezer, Viktor; Spekkers, Matthieu; Kreibich, Heidi

    2016-04-01

    Pluvial floods have caused severe damages to urban dwellings in Europe and elsewhere in recent years. With a predicted increase in extreme weather events as well as an ongoing urbanization, pluvial flood damage is expected to increase in the future. These type of flood events, caused by stormwater being unable to enter urban drainage systems or flowing out of urban drainage systems when capacity is exceeded, often happen with little warning and in areas which are often not obviously prone to flooding. Up to now little research was done on the adverse consequences of pluvial floods, as empirical damage data of pluvial flooding is scarce. In this study, results of two telephone surveys are discussed. The surveys comprise interviews with more than 500 flood-affected households in Germany (Münster and Greven) and the Netherlands (Amsterdam), related to the severe rain event of July 28th 2014. Respondents were asked a series of questions about the damage to their building structure and contents, as well as on topics such as early warning, emergency and precautionary measures, building properties and hazard characteristics. The questionnaire was developed with the aim to create a harmonized transnational pluvial flood damage survey that can potentially be extended to other European countries. New indicator variables have been developed to account for different national and regional standards in building structure, early warning, socio-economic data and recovery. The survey data from the German and Dutch case studies are compared with the goal to identify similarities and differences in damage reducing factors and recovery. Water level data and other hazard characteristics are used to form comparable groups out of the German and Dutch sample. Within these groups, regional distinctions in building topology and use are expected to have the strongest impact on differences between reported damage amounts of the two case studies. The newly collected data will be used in

  7. Effects of Urbanization on Flood Response: Analyses of the 17 - 18 July 1996 Chicago Metropolitan Area Event

    NASA Astrophysics Data System (ADS)

    Cobb, J.; Sturdevant-Rees, P. L.; Smith, J. A.

    2002-05-01

    On 17-18 July 1996, two mesoscale convective systems (MCS) passed through Northeastern Illinois causing a record 43-cm total storm rainfall within a 24-hr period at Aurora. Rainfall accumulations exceeded the 100-year return interval at many additional stations throughout the region. The storm resulted in flash flooding in the Chicago metropolitan area, where rain exceeded 25 cm, and caused the death of six people and approximately \\$645 million dollars worth of damage. The existence of a dense network of raingauges combined with NWS WSR-88D radar coverage allow high quality characterization of the storm at fine spatial and temporal scales. These data, along with the availability of historical landuse information, enable the effects of urbanization on flooding to be explored through the use of hydrologic models. The Princeton Network Model is a distributed hydrologic model that utilizes Green and Ampt infiltration with redistribution, multiple surface water routing options, and radar precipitation data. This model is used to explore the integrated hydrometeorological, hydrologic, and hydraulic processes that control urban flash flooding. In particular, the anthropogenic influences and fundamental physical processes at the land surface that control urban extreme flood hydrology and hydraulics are examined. Modeling focuses on flooding in the Sawmill Creek watershed, the East Branch DuPage River, and the West Branch DuPage River resulting from the 17 - 18 July 1996 event. Peak discharges with a greater than 100-year return interval were observed in these watersheds.

  8. The 1993 Mississippi river flood: A one hundred or a one thousand year event?

    USGS Publications Warehouse

    Malamud, B.D.; Turcotte, D.L.; Barton, C.C.

    1996-01-01

    Power-law (fractal) extreme-value statistics are applicable to many natural phenomena under a wide variety of circumstances. Data from a hydrologic station in Keokuk, Iowa, shows the great flood of the Mississippi River in 1993 has a recurrence interval on the order of 100 years using power-law statistics applied to partial-duration flood series and on the order of 1,000 years using a log-Pearson type 3 (LP3) distribution applied to annual series. The LP3 analysis is the federally adopted probability distribution for flood-frequency estimation of extreme events. We suggest that power-law statistics are preferable to LP3 analysis. As a further test of the power-law approach we consider paleoflood data from the Colorado River. We compare power-law and LP3 extrapolations of historical data with these paleo-floods. The results are remarkably similar to those obtained for the Mississippi River: Recurrence intervals from power-law statistics applied to Lees Ferry discharge data are generally consistent with inferred 100- and 1,000-year paleofloods, whereas LP3 analysis gives recurrence intervals that are orders of magnitude longer. For both the Keokuk and Lees Ferry gauges, the use of an annual series introduces an artificial curvature in log-log space that leads to an underestimate of severe floods. Power-law statistics are predicting much shorter recurrence intervals than the federally adopted LP3 statistics. We suggest that if power-law behavior is applicable, then the likelihood of severe floods is much higher. More conservative dam designs and land-use restrictions Nay be required.

  9. Magnitude of a catastrophic flood event at Kasei Valles, Mars

    NASA Astrophysics Data System (ADS)

    Robinson, Mark S.; Tanaka, Kenneth L.

    1990-09-01

    Kasei Valles compose an enormous outflow-channel system on Mars. The upper part of the channel system is typically less than 1 km deep and descends from Echus Chasma about 1 km over a distance of 1000 km; it then splits into north and south channels. On the basis of a stereomodel of Viking images, we have measured the geometry of a steep, constricted reach of the north channel that drops 900 m in only 100 km. A late-stage flood is hypothesized to have scoured the channel. If we assume that channel striations indicate water levels, then the flood had a minimum cross-sectional area of 3.12 x 107 m2 (the putative flood had a width of 83 km, an average depth of 374 m, and maximum depth of 1280 m). These channel measurements suggest that flood velocities ranged from 32 to 75 mṡs-1 and that discharge was greater than 1 km3ṡs-1, values larger than those calculated for any other flood event on Mars or Earth. The flood maintained supercritical flow and caused intense erosion in this area, scouring a 350-m-deep megapothole. The source of the flood water may have been a temporary lake in Echus Chasma, a deep canyon formed in association with tectonism at Valles Marineris.

  10. Modelling the interaction between flooding events and economic growth

    NASA Astrophysics Data System (ADS)

    Grames, Johanna; Fürnkranz-Prskawetz, Alexia; Grass, Dieter; Viglione, Alberto; Blöschl, Günter

    2016-04-01

    Recently socio-hydrology models have been proposed to analyze the interplay of community risk-coping culture, flooding damage and economic growth. These models descriptively explain the feedbacks between socio-economic development and natural disasters such as floods. Complementary to these descriptive models, we develop a dynamic optimization model, where the inter-temporal decision of an economic agent interacts with the hydrological system. This interdisciplinary approach matches with the goals of Panta Rhei i.e. to understand feedbacks between hydrology and society. It enables new perspectives but also shows limitations of each discipline. Young scientists need mentors from various scientific backgrounds to learn their different research approaches and how to best combine them such that interdisciplinary scientific work is also accepted by different science communities. In our socio-hydrology model we apply a macro-economic decision framework to a long-term flood-scenario. We assume a standard macro-economic growth model where agents derive utility from consumption and output depends on physical capital that can be accumulated through investment. To this framework we add the occurrence of flooding events which will destroy part of the capital. We identify two specific periodic long term solutions and denote them rich and poor economies. Whereas rich economies can afford to invest in flood defense and therefore avoid flood damage and develop high living standards, poor economies prefer consumption instead of investing in flood defense capital and end up facing flood damages every time the water level rises. Nevertheless, they manage to sustain at least a low level of physical capital. We identify optimal investment strategies and compare simulations with more frequent and more intense high water level events.

  11. Assessing the Impacts of Flooding Caused by Extreme Rainfall Events Through a Combined Geospatial and Numerical Modeling Approach

    NASA Astrophysics Data System (ADS)

    Santillan, J. R.; Amora, A. M.; Makinano-Santillan, M.; Marqueso, J. T.; Cutamora, L. C.; Serviano, J. L.; Makinano, R. M.

    2016-06-01

    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 useful to the

  12. Flood basalt eruptions, comet showers, and mass extinction events

    NASA Technical Reports Server (NTRS)

    Rampino, Michael R.; Stothers, Richard B.

    1988-01-01

    A chronology of initiation dates of the major continental flood basalt episodes has been established from compilation of published K-Ar and Ar-Ar ages of basaltic flows and related basic intrusions. The dating is therefore independent of the biostratigraphic and paleomagnetic time scales, and the estimated errors of the inititation dates are approximately + or - 4 pct. There are 11 distinct episodes of continental flood basalts known during the past 250 Myr. The data show that flood basalt episodes are generally relatively brief geologic events, with intermittent eruptions during peak output periods lasting ony 2 to 3 Myr or less. Statistical analyses suggest that these episodes may have occurred quasi-periodically with a mean cycle time of 32 + or - 1 Myr. The initiation dates of the flood basalts are close to the estimated dates of marine mass extinctions and impact-crater clusters. Although a purely internal forcing might be argued for the flood basalt volcanism, quasi-periodic comet impacts may be the trigger for both the flood basalts and the extinctions. Impact cratering models suggest that large-body impactors lead to deep initial cratering, and therefore may cause mantle disturbances and initiate mantle plume activity. The flood basalt episodes commonly mark the initiation or jump of a mantle hotspot, and are often followed by continental rifting and separation. Evidence from dynamical studies of impacts, occurrences of craters and hotspots, and the geochemistry of boundary layers is synthesized to provide a possible model of impact-generated volcanism. Flood basalt eruptions may themselves have severe effects on climate, and possibly on life. Impacts might, as a result, have led to mass extinctions through direct atmospheric disturbances, and/or indirectly through prolonged flood basalt volcanism.

  13. 100 years of Belgian rainfall: are there trends?

    PubMed

    Vaes, G; Willems, P; Berlamont, J

    2002-01-01

    In 1999 the digitisation of old rainfall records of measurements at Uccle (Belgium) was completed, which resulted in a unique rainfall series of 100 years (period 1898-1997). This is an ideal opportunity to search for trends in the rainfall over the last century. Large variations in rainfall probability over the century have been observed. For small aggregation levels there is a small decrease in extreme rainfall events over the century. For large aggregation levels there is a more explicit increase in extreme rainfall. Because the rainfall on seasonal aggregation level is only slightly increased, the increase in extreme rainfall events for aggregation levels between a few days and a few months can only occur due to larger clustering. However, the final conclusion is that no significant trend can be observed. A pure random variation of the rainfall can cause equally large variations. This does not exclude a possible trend in flooding frequency, due to the strong increase in urbanisation over the last century. PMID:11888184

  14. Annually laminated lake sediments as recorders of flood events: evidence from combining monitoring and calibration

    NASA Astrophysics Data System (ADS)

    Kämpf, Lucas; Brauer, Achim; Mueller, Philip; Güntner, Andreas; Merz, Bruno

    2015-04-01

    The relation of changing climate and the occurrence of strong flood events has been controversially debated over the last years. One major limitation in this respect is the temporal extension of instrumental flood time series, rarely exceeding 50-100 years, which is too short to reflect the full range of natural climate variability in a region. Therefore, geoarchives are increasingly explored as natural flood recorders far beyond the range of instrumental flood time series. Annually laminated (varved) lake sediments provide particularly valuable archives since (i) lakes form ideal traps in the landscape continuously recording sediment flux from the catchment and (ii) individual flood events are recorded as detrital layers and can be dated with seasonal precision by varve counting. Despite the great potential of varved lake sediments for reconstructing long flood time series, there are still some confinements with respect to their interpretation due to a lack in understanding processes controlling the formation of detrital layers. For this purpose, we investigated the formation of detrital flood layers in Lake Mondsee (Upper Austria) in great detail by monitoring flood-related sediment flux and comparing detrital layers in sub-recent sediments with river runoff data. Sediment flux at the lake bottom was trapped over a three-year period (2011-2013) at two locations in Lake Mondsee, one located 0.9 km off the main inflow (proximal) and one in a more distal position at a distance of 2.8 km. The monitoring data include 26 floods of different amplitude (max. hourly discharge=10-110 cbm/s) which triggered variable fluxes of catchment sediment to the lake floor (4-760 g/(sqm*d)). The comparison of runoff and sediment data revealed empiric runoff thresholds for triggering significant detrital sediment influx to the proximal (20 cbm/s) and distal lake basin (30 cbm/s) and an exponential relation between runoff amplitude and the amount of deposited sediment. A succession of

  15. Impacts of Land Use Management in Extreme Flood Events

    NASA Astrophysics Data System (ADS)

    O'Donnell, Greg; Ewen, John; Geris, Josie; Enda O'Connell, P.

    2010-05-01

    It is increasingly recognised internationally that the management of land and water is strongly interdependent, and that integrated management approaches are needed. There is evidence that modern land management practices have caused an increase in flood risk in rural upland areas, so there is the potential to use land management control as a tool in flood risk mitigation programmes. Flooding from historical extreme rainfall events must be considered when designing mitigation programmes, especially if the designs have to take into account the possibility that such extreme events will become more frequent in the future. The largest 90 minute rainfall ever recorded in the UK was 117mm, in 1967 in the Dunsop catchment, NW England (25 km^2). Extensive land management changes have recently been made in the catchment, including peat restoration, tree planting and reductions in sheep stocking density, and the analysis of the flooding in 1967 was undertaken as part of a wider study on the potential impact of the recent changes. An important part of the work on the 1967 flood was the separation of the various roles played in flood generation; particularly the roles played by runoff generation from the hillslopes and flow though the drainage/river network. A novel approach has been developed, for role separation, which involves tracking the downstream propagation of information through the catchment. This is achieved using reverse algorithmic differentiation (adjoint modelling) of a gridded catchment model that includes a detailed hydraulic model for the flow drainage/river network. Results will be shown for how various information and sensitivities vary spatially across the catchment, allowing conclusions to be drawn about the potential for using land management control in flood risk mitigation programmes.

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

    NASA Astrophysics Data System (ADS)

    Mei, Y.; Nikolopoulos, E. I.; Anagnostou, E. N.; Zoccatelli, D.; Borga, M., Sr.

    2015-12-01

    The error characteristics of satellite precipitation driven flood event simulations over mountainous basins are evaluated in this study for eight different global satellite products. A methodology is devised to match the observed records of the flood events with the corresponding satellite and reference rainfall and runoff simulations. The flood events are sorted according to flood type (i.e. rain flood and flash flood) and basin's antecedent conditions represented by the event's runoff-to-precipitation ratio. 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. cumulative volume, timing and shape). Overall satellite-driven event runoff exhibits better error metrics than the satellite precipitation. Better error metrics are also shown for the rain flood events relative to the flash flood events. The event timing and shape from satellite-derived precipitation agreed well with the reference; the cumulative volume is mostly underestimated. In terms of error propagation, the study shows dampening effect in both systematic and random error components of the satellite-driven runoff time series relative to the satellite-retrieved event precipitation. This error dampening effect is less pronounced for the flash flood events and the rain flood events with high runoff coefficients. This study provides for a first time flood event characteristics of the satellite precipitation error propagation in flood modeling, which has implications on the Global Precipitation Measurement application in mountain flood hydrology.

  17. Post flash flood field investigations and analysis: the event of 22 November 2011 in the Longano catchment, Italy

    NASA Astrophysics Data System (ADS)

    Tito Aronica, Giuseppe; Cavalli, Marco; Gaume, Eric; Marchi, Lorenzo; Naso, Susanna; Borga, Marco

    2014-05-01

    On 22 November 2011, an exceptional rainstorm hit the North-East part of Sicily (Italy) producing local heavy rainfall, mud-debris flow and flash flooding. The storm was concentrated on the Tyrrhenian Sea coast, near the city of Barcellona within the Longano catchment (26 km2). It started at 5.00 am and lasted for approximately 11 hours, with a return period greater than 100 years yet for 2 hours duration and greater than 300 years yet for 3 hours'. The aim of this work is to investigate the flood response in order to document the rainfall and flood properties and to analyze the characteristics of the event water balance. Fine resolution distributed rainfall estimates were obtained by combining observations from the Monte Lauro Doppler C-band weather radar, satellite data and the raingauge network. Satellite data were used to correct for the severe beam blocking due to the effect of orography on the radar beam propagation. A detailed study of the hydrological response of the catchment was performed by means of a rainfall-runoff modeling and flood frequency analysis. To ensure model simulation accuracy, the model results were compared with peak discharges obtained from post flood field estimates based on high water marks and cross section surveying. Peak flood timing from the model were contrasted with data gathered from witnesses interviews and video recordings. The estimated flood peak discharge of the Longano river in the city of Barcellona is around 230 m3/s, indicating a very intense response which is in the range of the extreme events for similar size catchments in Sicily. Flood inundation and propagation in the city were modeled using a 2D hydraulic model based on De Saint Venant equations previously calibrated using the observations concerning water depths and flow velocities. A geomorphological survey was also conducted to document erosion and sedimentation processes associated to the extreme flood.

  18. Environmental impacts of Major Flood Events: Hurricane Katrina

    NASA Astrophysics Data System (ADS)

    Reible, D. D.

    2008-05-01

    The flooding of New Orleans by Hurricane Katrina provides many lessons for the environmental and engineering communities and raises serious public policy questions about risk management. Although serious environmental and waste management concerns were highlighted as a result of the flooding, many were not observed in the extensive environmental sampling that occurred. The potential environmental consequences were of concern because of the many chemical plants, petroleum facilities, and contaminated sites, including Superfund sites, in the areas covered by floodwaters. The potential sources of toxics and environmental contaminants included metal-contaminated soils typical of old urban areas. Compounding these concerns is the presence of hazardous chemicals commonly stored in households and commercial establishments and the fuel and motor oil in approximately 350,000 flooded automobiles. Uncontrolled biological wastes from both human and animal sources also contributed to the pollutant burden. There were concerns associated with the immediate impacts of the flooding, the disposal of the debris and wastes in the aftermath, as well as the long- term legacy associated with contaminants in homes and yards. This discussion focuses on successes and failures in responding to each of these concerns as well as lessons learned for future major flooding events. Special attention is paid to some of the unique hazards posed by Katrina, including water quality impacts associated with debris disposal, high indoor concentrations of contaminants due to fractionation from outdoor soils, and mold.

  19. Management of a Complex Open Channel Network During Flood Events

    NASA Astrophysics Data System (ADS)

    Franchini, M.; Valiani, A.; Schippa, L.; Mascellani, G.

    2003-04-01

    Most part of the area around Ferrara (Italy) is below the mean sea level and an extensive drainage system combined with several pump stations allows the use of this area for both urban development and industrial and agricultural activities. The three main channels of this hydraulic system constitute the Ferrara Inland Waterway (total length approximately 70 km), which connects the Po river near Ferrara to the sea. Because of the level difference between the upstream and dowstream ends of the waterway, three locks are located along it, each of them combined with a set of gates to control the water levels. During rainfall events, most of the water of the basin flows into the waterway and heavy precipitations sometimes cause flooding in several areas. This is due to the insufficiency of the channel network dimensions and an inadequate manual operation of the gates. This study presents a hydrological-hydraulic model for the entire Ferrara basin and a system of rules in order to operate the gates. In particular, their opening is designed to be regulated in real time by monitoring the water level in several sections along the channels. Besides flood peak attenuation, this operation strategy contributes also to the maintenance of a constant water level for irrigation and fluvial navigation during the dry periods. With reference to the flood event of May 1996, it is shown that this floodgate operation policy, unlike that which was actually adopted during that event, would lead to a significant flood peak attenuation, avoiding flooding in the area upstream of Ferrara.

  20. The flood event of November 2013 in Calabria (southern Italy): damage and hydrogeological characteristics

    NASA Astrophysics Data System (ADS)

    Petrucci, Olga; Caloiero, Tommaso; Aurora Pasqua, Angela

    2014-05-01

    On November 19th, 2013, Calabria region (southern Italy) has been affected by a flood event which caused numerous damages in particular in the Ionian side of the region. In this work, the event is analyzed in terms of damage and hydrologic features. Beside rainfall, the event has been characterized by intense sea storms which, increased by Sirocco gusts, obstructed the outlet of the floods toward the sea. As a result, river overflowing was amplified and caused the breaking of either natural or artificial embankments. Damage affected 49 municipalities located in the mid-east sector, on a surface of 1898 km2 (12.6% of the Calabrian area). Roads (damaged in 86% of the affected municipalities) and private buildings (39%) were the most heavily damaged elements: in many cases the water level reached 1m. People were directly involved in risky situations but they managed to save their lives: only two people were injured. Return periods of daily rain can be classified as ordinary (between 2 and 13 years) with the only exception of a gauge located in the northern east sector, which showed a return period of more than 100 years. On the contrary, 3-hour rain shows peak values of 160 mm and return period higher than 200 years. As a result, the event can be considered an "impulsive" one, powered by intense hourly rain, and its dangerousness was mainly related to the "flash" character of the triggered floods. The analysis of circumstances in which people were directly threatened confirms floods as the main source of risk, both indoors (65% of cases) and outdoors (35%); in the latter case, the majority of people involved were on board of vehicles (26%). Differently from the past Calabrian damaging hydrogeological events, people did not adopt unnecessary risky behaviors, and in 26% of cases they managed to save their life without any help. Probably this is the factor that lead to low damage to people, since only two people were slightly injured. These results could be proficiently

  1. Modelling the interaction between flooding events and economic growth

    NASA Astrophysics Data System (ADS)

    Grames, Johanna; Grass, Dieter; Prskawetz, Alexia; Blöschl, Günther

    2015-04-01

    Socio-hydrology describes the interaction between the socio-economy, water and population dynamics. Recent models analyze the interplay of community risk-coping culture, flooding damage and economic growth (Di Baldassarre, 2013, Viglione, 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. This is the first economic growth model describing the interaction between the consumption and investment decisions of an economic agent and the occurrence of flooding events: Investments in defense capital can avoid floods even when the water level is high, but on the other hand such investment competes with investment in productive capital and hence may reduce the level of consumption. When floods occur, the flood damage therefore depends on the existing defense capital. The aim is to find an optimal tradeoff between investments in productive versus defense capital such as to optimize the stream of consumption in the long-term. We assume a non-autonomous exogenous periodic rainfall function (Yevjevich et.al. 1990, Zakaria 2001) which implies that the long-term equilibrium will be periodic . With our model we aim to derive mechanisms that allow consumption smoothing in the long term, and at the same time allow for optimal investment in flood defense to maximize economic output. We choose an aggregate welfare function that depends on the consumption level of the society as the objective function. I.e. we assume a social planer with perfect foresight that maximizes the aggregate welfare function. Within our model framework we can also study whether the path and level of defense capital (that protects people from floods) is related to the time preference rate of the social planner. Our model also allows to investigate how the frequency

  2. Flash flooding in small urban watersheds: Storm event hydrologic response

    NASA Astrophysics Data System (ADS)

    Yang, Long; Smith, James A.; Baeck, Mary Lynn; Zhang, Yan

    2016-06-01

    We analyze flash flooding in small urban watersheds, with special focus on the roles of rainfall variability, antecedent soil moisture, and urban storm water management infrastructure in storm event hydrologic response. Our results are based on empirical analyses of high-resolution rainfall and discharge observations over Harry's Brook watershed in Princeton, New Jersey, during 2005-2006, as well as numerical experiments with the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model. We focus on two subwatersheds of Harry's Brook, a 1.1 km2 subwatershed which was developed prior to modern storm water management regulations, and a 0.5 km2 subwatershed with an extensive network of storm water detention ponds. The watershed developed prior to modern storm water regulations is an "end-member" in urban flood response, exhibiting a frequency of flood peaks (with unit discharge exceeding 1 m3 s-1 km-2) that is comparable to the "flashiest" watersheds in the conterminous U.S. Observational analyses show that variability in storm event water balance is strongly linked to peak rain rates at time intervals of less than 30 min and only weakly linked to antecedent soil moisture conditions. Peak discharge for both the 1.1 and 0.5 km2 subwatersheds are strongly correlated with rainfall rate averaged over 1-30 min. Hydrologic modeling analyses indicate that the sensitivity of storm event hydrologic response to spatial rainfall variability decreases with storm intensity. Temporal rainfall variability is relatively more important than spatial rainfall variability in representing urban flood response, especially for extreme storm events.

  3. Incorporating flood event analyses and catchment structures into model development

    NASA Astrophysics Data System (ADS)

    Oppel, Henning; Schumann, Andreas

    2016-04-01

    The space-time variability in catchment response results from several hydrological processes which differ in their relevance in an event-specific way. An approach to characterise this variance consists in comparisons between flood events in a catchment and between flood responses of several sub-basins in such an event. In analytical frameworks the impact of space and time variability of rainfall on runoff generation due to rainfall excess can be characterised. Moreover the effect of hillslope and channel network routing on runoff timing can be specified. Hence, a modelling approach is needed to specify the runoff generation and formation. Knowing the space-time variability of rainfall and the (spatial averaged) response of a catchment it seems worthwhile to develop new models based on event and catchment analyses. The consideration of spatial order and the distribution of catchment characteristics in their spatial variability and interaction with the space-time variability of rainfall provides additional knowledge about hydrological processes at the basin scale. For this purpose a new procedure to characterise the spatial heterogeneity of catchments characteristics in their succession along the flow distance (differentiated between river network and hillslopes) was developed. It was applied to study of flood responses at a set of nested catchments in a river basin in eastern Germany. In this study the highest observed rainfall-runoff events were analysed, beginning at the catchment outlet and moving upstream. With regard to the spatial heterogeneities of catchment characteristics, sub-basins were separated by new algorithms to attribute runoff-generation, hillslope and river network processes. With this procedure the cumulative runoff response at the outlet can be decomposed and individual runoff features can be assigned to individual aspects of the catchment. Through comparative analysis between the sub-catchments and the assigned effects on runoff dynamics new

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

    NASA Astrophysics Data System (ADS)

    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

  5. Modelling the interaction between flooding events and economic growth

    NASA Astrophysics Data System (ADS)

    Grames, J.; Prskawetz, A.; Grass, D.; Blöschl, G.

    2015-06-01

    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.

  6. Modelling Inland Flood Events for Hazard Maps in Taiwan

    NASA Astrophysics Data System (ADS)

    Ghosh, S.; Nzerem, K.; Sassi, M.; Hilberts, A.; Assteerawatt, A.; Tillmanns, S.; Mathur, P.; Mitas, C.; Rafique, F.

    2015-12-01

    . Major historical flood events have been successfully simulated along with spatial patterns of flows. Comparison of stochastic discharge statistics w.r.t. observed ones from Hydrological Year Books of Taiwan over all recorded years are also in good agreement.

  7. The flood event that affected Badajoz in November 1997

    NASA Astrophysics Data System (ADS)

    Lorente, P.; Hernández, E.; Queralt, S.; Ribera, P.

    2008-04-01

    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.

  8. Genoa 2014 flash flood event: from precipitation observations to flood mapping

    NASA Astrophysics Data System (ADS)

    Rebora, Nicola; Fiorini, Mattia; Gabellani, Simone; Parodi, Antonio; Pignone, Flavio; Rudari, Roberto; Silvestro, Francesco

    2015-04-01

    On the 9th of October, the city of Genoa, the capital of the Liguria Region, located at the meridional edge of the local Appennines range was gutted by an extreme rainfall event with up to 300 millimeters of rain in 5 hours. Only three years ago an anomalous intense rainstorm ripped through the Liguria Region and inflicted serious damage at the city of Genoa. The raingauge stations, in the center of the event, registered up to 450 millimetres of rain in 5 hours (7 km from the coast over a 300 m hill), a third of the average annual rainfall, with a peak of 150 mm in one hour. Six people were killed. With this work we analyze the Genoa 2014 Flash Flood in terms of precipitation observations by radar and raingauges, in terms of hydrological response of the Bisagno river using the Continuum hydrological model, and in terms of urban flooding in the city center using a 2D hydraulic model. Our aim is twofold: from one side we want to present the event through the observational data and through the simulations available, and on the other side we want to discuss the steps we can do in managing such events in a densely populated area.

  9. Simulating rainfall-runoff dynamics of selected flash flood events in Slovakia using the KLEM hydrological model

    NASA Astrophysics Data System (ADS)

    Horvat, O.; Hlavcova, K.; Kohnova, S.; Szolgay, J.; Remiasova, R.

    2009-04-01

    The HYDRATE project (Hydrometeorological Data Resources and Technologies for Effective Flash Flood Forecasting) objective is to improve the scientific basis of flash flood forecasting by extending the understanding of past flash flood events and developing a coherent set of technologies and tools for effective early warning systems. To understand rainfall-runoff processes during selected extreme flash floods occurred in the past in Slovakia, runoff responses during selected major events were examined by using the spatially distributed hydrologic model KLEM (Kinematic Local Excess Model (Borga et al., 2007)). The distributed hydrological model is based on availability of raster information of the landscape topography, the soil and vegetation properties and radar rainfall data. In the model, the SCS-Curve Number procedure is applied on a grid way for the spatially distributed representation of runoff generating processes. For representing runoff routing a description of the drainage system response is used. In Slovakia, 3 extreme events selected from the HYDRATE flash-flood database were simulated by the model. Three selected major flash floods occurred 20th of July 1998 in the Malá Svinka and Dubovický creeks, 24th of July 2001 in the Štrbský Creek (both with more than 1000-years return period) and 19th of June 2004 in the Turniansky Creek (with 100-years return period). Rainfall-runoff characteristics of the floods in the Malá Svinka, Dubovický and Štrbský creek basins were similar and the floods had a similar progress. A value of runoff coefficient varied from 0.39 to 0.56. Opposite to them, the highest runoff coefficient in the Turniansky Creek Basin only reached a value equal to 0.26. The simulated values by the KLEM model were comparable with maximum peaks estimated on the base of post event surveying. The consistency of the estimated and simulated values by the KLEM model was evident both in time and space and the methodology has shown its

  10. Characteristics and dependencies of error in satellite-based flood event simulations

    NASA Astrophysics Data System (ADS)

    Mei, Yiwen; Nikolopoulos, Efthymios I.; Anagnostou, Emmanouil N.; Zoccatelli, Davide; Borga, Marco

    2016-04-01

    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 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 time series shows significant dampening effect. The random error dampening effect is less pronounced for the flash flood events, and the rain flood events with 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.

  11. What made the June 2013 flood in Germany an exceptional event? A hydro-meteorological evaluation

    NASA Astrophysics Data System (ADS)

    Schröter, K.; Kunz, M.; Elmer, F.; Mühr, B.; Merz, B.

    2014-07-01

    The summer flood 2013 sets a new record for large-scale floods in Germany since at least 1952. In this paper we analyze the key hydro-meteorological factors using extreme value statistics as well as aggregated severity indices. For the long-term classification of the recent flood we draw comparisons to a set of past large-scale flood events in Germany, notably the high impact summer floods from August 2002 and July 1954. Our analysis shows that the combination of extreme initial wetness at the national scale - caused by a pronounced precipitation anomaly in the month of May 2013 - and strong, but not extraordinary event precipitation were the key drivers for this exceptional flood event. This provides new insights to the importance of antecedent soil moisture for high return period floods on a large-scale. The data base compiled and the methodological developments provide a consistent framework for the rapid evaluation of future floods.

  12. River flood events in Thailand and Bangladesh observed by CryoSat-2

    NASA Astrophysics Data System (ADS)

    Nielsen, Karina; Villadsen, Heidi; Andersen, Ole; Stenseng, Lars; Knudsen, Per

    2015-04-01

    The high along track resolution of the SIRAL altimeter carried on-board CryoSat-2 offers a wide range of unique opportunities for satellite monitoring. This study focuses on the ability of CryoSat-2 to detect the effects of flood events such as increased river levels and inundation of land. Here we study two flood events; the Bangladesh flood event of June 2012 and the flooding in Thailand that lasted between July 2011 and January 2012. The flooding in these areas was caused by abnormal monsoonal rainfall and affected millions of people. We process CryoSat-2 level 1b SAR mode data to derive water levels for the areas and compare these levels before, during and after the flooding events. Other parameters such as the backscatter coefficient and pulse peakiness are also considered. To verify the extent of the flooding observed by CryoSat-2 we compare with independent sources such as Landsat images.

  13. Convergence: Human Intelligence The Next 100 Years

    ERIC Educational Resources Information Center

    Fluellen, Jerry E., Jr.

    2005-01-01

    How might human intelligence evolve over the next 100 years? This issue paper explores that idea. First, the paper summarizes five emerging perspectives about human intelligence: Howard Gardner's multiple intelligences theory, Robert Sternberg's triarchic theory of intelligence, Ellen Langer's mindfulness theory, David Perkins' learnable…

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

    USGS Publications Warehouse

    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.

  15. The AAS: Its Next 100 Years

    NASA Astrophysics Data System (ADS)

    Wolff, S.

    1999-05-01

    The AAS: Its Next Hundred Years "We are probably nearing the limit of all we can know about astronomy."-- Simon Newcomb, 1888. The best way to celebrate the centennial of the AAS is to look forward, not backward, and to begin planning for the next 100 years. However, predicting the future is even more difficult than it was in Newcomb's time. We live in an era characterized by an unprecedented rate of change in the kinds of scientific questions we ask, the tools we use to answer them, and the way we communicate our results. This talk will highlight some of the issues that we will face as a community during the next 10--but not the next 100!--years and suggests that the AAS has a fundamental role to play in shaping the community response to these issues.

  16. The December 2008 flood event in Rome: Was it really an extreme event?

    NASA Astrophysics Data System (ADS)

    Lastoria, B.; Mariani, S.; Casaioli, M.; Bussettini, M.

    2009-04-01

    In mid December 2008, Italy suffered bad weather with heavy snowfall blanketing the north and strong winds and downpours pelting the centre-south. In particular, during the period between 10th and 12th December, intense precipitation struck the Tyrrhenian Sea side of the peninsula, inducing a flood event, which captured the attention of the national and international media, on the Tiber river and on its tributary, the Aniene. The relevance of the event was caused by the actual damages occurred in several zones over Rome area, in particular due to the downpours and to damages which would have occurred if Tiber river had overflowed its banks. The event, which was initially considered as extreme, was indeed severe but not so exceptional as shown by the meteo-hydrological post-event analysis. The peak water level of 12.55 m, recorded on 13th December at 1:30 a.m. (local time) at the Ripetta station, which is situated along the Tiber river in the centre of Rome, was higher than those observed during the last ten years (which to the utmost reached 11.41 m in December 2005). However, it did not reach the historical maximum of 16.90 m observed in 1937. Moreover, on the basis of the Ripetta historical series, such a level is associated to an ordinary flood event. Even if the flood was ordinary, a state of emergency was declared by the Rome's Mayor, since the event caused severe damages by disrupting flight and train services, blocking off major roads leading into Rome, flooding underpasses and sealing off industrial activities sited in the flooded areas, in particular nearby the confluence of the Aniene river with the Tiber river. In addition, hundreds of people were evacuated and a woman died in a her car which was submerged by a wave of water and mud in an underpass. Given these premises, the present work examines the relation between a severe, but not extraordinary, event and the considerable damages that occurred as a consequence. First, the meteorological evolution of

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

    PubMed

    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. PMID:23128626

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Optimization of rainfall thresholds for a flood warning system to Taiwan urban areas during storm events

    NASA Astrophysics Data System (ADS)

    Liao, Hao-Yu; Pan, Tsung-Yi; Su, Ming-Daw; Hsieh, Ming-Chang; Tan, Yih-Chi

    2016-04-01

    Flood is one of the most damage disaster that always happen around the world. Because of the extreme weather change, the flood disaster damage becomes higher than before. In recent years, Taiwan suffered from flood damage frequently by excessive rainfall induced by extreme weather, like typhoons. Therefore, it is necessary to build an effective flood warning system to reduce the flood damage. The operational flood warning system in Taiwan is based on the rainfall thresholds. When cumulative rainfall over the rainfall thresholds, the flood warning system would alert the local government where region would happen flood disaster. According to the flood warning system alert, the governments have more time to prepare how to face the flood disaster before happens. Although Taiwanese government has a preliminary flood warning system, the system has still lack of theoretical background. For this reason, the alert accuracy of the system is limited. Thus it is important to develop the effective rainfall thresholds that could predict flood disaster successfully. The research aims to improve the accuracy of the system through statistical methods. When the accumulated rainfall reaches the alert value, the warning message would be announced early to government for dealing with flooding damage which would happen. According to extreme events, the data driven and statistical methods are adopted to calculate the optimum rainfall thresholds. The results of this study could be applied to enhance rainfall thresholds forecasting accuracy, and could reduce the risk of floods.

  20. An integrated system for hydrological analysis of flood events

    NASA Astrophysics Data System (ADS)

    Katsafados, Petros; Chalkias, Christos; Karymbalis, Efthymios; Gaki-Papanastassiou, Kalliopi; Mavromatidis, Elias; Papadopoulos, Anastasios

    2010-05-01

    The significant increase of extreme flood events during recent decades has led to an urgent social and economic demand for improve prediction and sustainable prevention. Remedial actions require accurate estimation of the spatiotemporal variability of runoff volume and local peaks, which can be analyzed through integrated simulation tools. Despite the fact that such advanced modeling systems allow the investigation of the dynamics controlling the behavior of those complex processes they can also be used as early warning systems. Moreover, simulation is assuming as the appropriate method to derive quantitative estimates of various atmospheric and hydrologic parameters especially in cases of absence reliable and accurate measurements of precipitation and flow rates. Such sophisticated techniques enable the flood risk assessment and improve the decision-making support on protection actions. This study presents an integrated system for the simulation of the essential atmospheric and soil parameters in the context of hydrological flood modeling. The system is consisted of two main cores: a numerical weather prediction model coupled with a geographical information system for the accurate simulation of groundwater advection and rainfall runoff estimation. Synoptic and mesoscale atmospheric motions are simulated with a non-hydrostatic limited area model on a very high resolution domain of integration. The model includes advanced schemes for the microphysics and the surface layer physics description as well as the longwave and sortwave radiation budget estimation. It is also fully coupled with a land-surface model in order to resolve the surface heat fluxes and the simulation of the air-land energy exchange processes. Detailed atmospheric and soil parameters derived from the atmospheric model are used as input data for the GIS-based runoff modeling. Geographical information system (GIS) technology is used for further hydrological analysis and estimation of direct

  1. Remembering Robert Goddard's vision 100 years later

    NASA Astrophysics Data System (ADS)

    Stern, David P.

    “Life, liberty, and the pursuit of happiness” —such are the goals of most of us.Yet a few always exist who feel called by a higher purpose. Society often owes them a great deal.Robert Hutchins Goddard, whose work made spaceflight possible, found his vision 100 years ago this October as a youth of 17. His family was staying on the farm of a relative, when he was asked to trim the branches of a cherry tree behind the barn.

  2. Tsunami flooding along Tagus estuary, Portugal, the 1531 event

    NASA Astrophysics Data System (ADS)

    Baptista, M. A.; Miranda, J. M.; Batlo, J.; Ferreira, H.

    2012-04-01

    TSUNAMI FLOODING ALONG TAGUS ESTUARY (PORTUGAL), THE 1531 EVENT The city of Lisbon one of the main towns in Europe between the XVI and XVIII centuries was severely damaged by two strong earthquakes: 1531-01-26 and 1755-11-01 and the companion tsunamis. In this study we present a re-evaluation of the data available for this event. The 26 January 1531 earthquake occurred between 4 and 5 am and was felt mainly in Lisbon and surroundings dwellings along the Tagus river estuary. The shock heavily destroyed Lisbon downtown causing approximately 1000 casualties Two foreshocks preceded the event: on the 2nd and the 7th January 1531, respectively. The maximum MSK intensity is IX, making it one of the most disastrous earthquakes in the recent history of Portugal. The historical descriptions clearly describe the observation of high waves and the ships touching the riverbed. Although, the difference between tsunamis and storms is sometimes unclear in some historical documents, in this case, the occurrence of the of the earthquake definitively states clearly excludes the hypothesis of a storm. Moreover, the king's chronicle clearly states the observation of high waves and the lack of wind. Other reports consistent with the occurrence of a tsunami are the observation of strong fluxes and refluxes in the river the division of islands into smaller ones and the observation of the riverbed. In this study we present a re-appraisal of the historical information available, a new isoseismal map and the relocation of the epicentre. Finally, we present a tsunami simulation and propagation along a section of 70 km along Tagus estuary compatible with the earthquake data and the historical accounts.

  3. Assessment of Climate Change Impacts on Flood Event Types in Two Alpine Catchments

    NASA Astrophysics Data System (ADS)

    Turkington, T.; Breinl, K.; Jetten, V.; Ettema, J.

    2014-12-01

    A variety of different climate factors can trigger floods: intense rainfall, long lasting rainfall or extreme amount of snowmelt. As a result, changes in climate extremes can affect both the frequency of floods, but also other factors such as seasonality and duration, all of which have implications on local social and ecological systems. Therefore, we present a technique for examining projected changes in flood events types, focusing on antecedent meteorological conditions. Floods (characterized by the historical 10 and 25-year return level discharge) are clustered into causal types based on rainfall, antecedent precipitation and temperature. A multi-site weather generator coupled with a conceptual rainfall-runoff model is employed to increase the number of flood events. Quantile mapping of precipitation and temperature projections is then used in the development of future discharge. The technique is applied to two different catchments in the European Alps: a smaller catchment in the southern French Alps, dominated by rain-on-snow floods, and a larger catchment in Austria, with more floods during summer. The results show that changes in precipitation and temperature can alter not only the frequency, but also the distribution of flood event types in the future. Furthermore, assessing changes in flood event types provides information about why the frequency of floods in an alpine catchment may change, even if the projections themselves are highly uncertain.

  4. Recent flood events in Germany - revealing damage influencing factors on residential property

    NASA Astrophysics Data System (ADS)

    Elmer, F.; Pech, I.; Thieken, A. H.; Kreibich, H.

    2009-04-01

    The trend of increasing damages due to floods can only be counteracted with effective flood management, based on reliable flood risk analysis. Better knowledge about the connections between flood losses and damage determining factors is necessary to improve damage estimation models. Thus extensive data about flood losses were collected at affected properties in Germany in the aftermath of floods in August 2002, August 2005 and April 2006. The data set contains more than 2100 residential damage cases. The data for the residential sector include information about building and content damages, evacuation, locations of the objects, people living at the sites and their socioeconomic situation, flood experience, precautionary measures undertaken before and during the event as well as flood information like maximum water level, flood duration, and flow velocity at the affected buildings. As first analyses showed significantly higher average damages caused by the extreme event in 2002 than by the 2005 and 2006 events the data sets were amended by adding site specific information about the recurrence interval of the event. Therefore, an estimation of the flood annuality was done for more than 120 gauges in the affected areas. The results were assigned to each damaged object to be able to analyze the influence of the magnitude on the flood damage. Thus, the data set enables a comparative analysis of multiple events of different severity that occurred over a couple of years in the same regions. Variables that contribute most to the explanation of damages are identified by multi-criteria analyses using data mining techniques and software, namely the WEKA-tool. In applying this routine to subsets (divided by region, by recurrence interval, by event) main differences in the contribution of single factors can be identified. The aim is to use the results for the improvement of existing flood damage estimation models.

  5. Identification and Analysis of Storm Tracks Associated with Extreme Flood Events in Southeast and South Brazil

    NASA Astrophysics Data System (ADS)

    Lima, Carlos; Lopes, Camila

    2015-04-01

    Flood is the main natural disaster in Brazil, practically affecting all regions in the country and causing several economical damages and losses of lives. In traditional hydrology, the study of floods is focused on a frequency analysis of the extreme events and on the fit of statistical models to define flood quantiles associated with pre-specified return periods or exceedance probabilities. The basic assumptions are randomness and temporal stationarity of the streamflow data. In this paper we seek to advance the traditional flood frequency studies by using the ideas developed in the area of flood hydroclimatology, which is defined as the study of climate in the flood framework, i.e., the understanding of long term changes in the frequency, magnitude, duration, location and seasonality of floods as driven by the interaction of regional and global patterns of the ocean and atmospheric circulation. That being said, flood events are not treated as random and stationary but resulting from a causal chain, where exceptional floods in water basins from different sizes are related with large scale anomalies in the atmospheric and ocean circulation patterns. Hence, such studies enrich the classical assumption of stationary flood hazard adopted in most flood frequency studies through a formal consideration of the physical mechanisms responsible for the generation of extreme floods, which implies recognizing the natural climate variability due to persistent and oscillatory regimes (e.g. ENSO, NAO, PDO) in many temporal scales (interannual, decadal, etc), and climate fluctuations in response to anthropogenic changes in the atmosphere, soil use and vegetation cover. Under this framework and based on streamflow gauge and reanalysis data, we identify and analyze here the storm tracks that preceded extreme events of floods in key flood-prone regions of the country (e.g. Parana and Rio Doce River basins) with such events defined based on the magnitude, duration and volume of the

  6. Vitamins: preparing for the next 100 years.

    PubMed

    Blumberg, Jeffrey B

    2012-10-01

    The insights gained from the last 100 years of vitamin research and applications have contributed substantially to our fundamental understanding of biology and importantly to the promotion of human health. There is no reason to think that the next 100 years will be any less fruitful if we are committed to preparing for them, particularly by changing four critical nutrition paradigms. First, we must move beyond the concept of preventing vitamin deficiencies and inadequacies to establishing health and, further, to creating optimal physiological functions. Each essential vitamin possesses different concentration thresholds for its variety of effects and the required balance necessary to achieving each has yet to be fully defined. Second, we must apply the research approaches and methods of “-omics,” systems biology, and imaging technologies to define the dynamic role of vitamins and their broad array of genomic, molecular, biochemical, and functional interactions. Such work is necessary to understand the multiplicity of vitamin actions and ultimately apply them directly at the level of the individual. Third, we must revise the concept of evidence-based nutrition away from its current hierarchical system to recognize in a comprehensive and integrated way the attributes of each type of approach to research. To adhere to a single gold standard of the randomized clinical trial ignores both how we have moved forward so productively during the last 100 years and the vital information to be gained from basic research and other human studies; further, it acts to stifle innovation in both scientific and regulatory affairs. Fourth, we must understand that changes in the supply and distribution of food during the next century are likely to be at least as dramatic as those which have occurred over this last one. For example, inevitable environmental constraints will require more food protein be derived from plant than animal sources, a shift that will directly impact the

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

    PubMed

    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. PMID:27114578

  8. Characterization of extreme flood and drought events in Singapore and investigation of their relationships with ENSO

    NASA Astrophysics Data System (ADS)

    Li, Xin; Babovic, Vladan

    2016-04-01

    Flood and drought are hydrologic extreme events that have significant impact on human and natural systems. Characterization of flood and drought in terms of their start, duration and strength, and investigation of the impact of natural climate variability (i.e., ENSO) and anthropogenic climate change on them can help decision makers to facilitate adaptions to mitigate potential enormous economic costs. To date, numerous studies in this area have been conducted, however, they are primarily focused on extra-tropical regions. Therefore, this study presented a detailed framework to characterize flood and drought events in a tropical urban city-state (i.e., Singapore), based on daily data from 26 precipitation stations. Flood and drought events are extracted from standardized precipitation anomalies from monthly to seasonal time scales. Frequency, duration and magnitude of flood and drought at all the stations are analyzed based on crossing theory. In addition, spatial variation of flood and drought characteristics in Singapore is investigated using ordinary kriging method. Lastly, the impact of ENSO condition on flood and drought characteristics is analyzed using regional regression method. The results show that Singapore can be prone to extreme flood and drought events at both monthly and seasonal time scales. ENSO has significant influence on flood and drought characteristics in Singapore, but mainly during the South West Monsoon season. During the El Niño phase, drought can become more extreme. The results have implications for water management practices in Singapore.

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

    NASA Astrophysics Data System (ADS)

    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

  10. The link between atmospheric blockings and Central European flood events - A case study

    NASA Astrophysics Data System (ADS)

    Lenggenhager, Sina; Martius, Olivia; Brönnimann, Stefan; Croci-Maspoli, Mischa

    2016-04-01

    Flood events are among the most devastating weather-related events in Europe and can lead to large economic losses and even fatalities. Several processes, such as heavy precipitation or snow melt, can be involved in the triggering of flood events. Here we focus on precipitation only. Important characteristics of the flood triggering precipitation events are their intensity and their duration, which in return depend on the intensity and the stationarity of the associated weather system. Atmospheric blockings, due to their longevity and stationarity can influence flood related precipitation event in several ways: i) The progression of the upstream weather systems is slowed and thereby the precipitation period over a catchment can be prolonged. ii) The cumulative effect of recurrent precipitation events occurring up- or downstream of a block can result in a flood event. The interaction between blockings and flood triggering weather events potentially works in both directions. Cloud diabatic processes can be central to the establishment and maintenance of blocking anticyclones. The precipitation responsible for the flood could hence potentially extend the lifetime and strength of a blocking anticyclone located downstream of the flooded area. Here we illustrate the different interactions based on a flood event of a major lake in southern Switzerland in October 2000. During the flood event and in the month before blockings were present downstream, over Scandinavia as well as upstream, over the North-Atlantic. Three extreme precipitation episodes occured in southern Switzerland in September and October 2000. The first one took place on 20 September and was associated with an atmospheric blocking over the north Atlantic. This blocking together with a downstream anticyclone led to the formation of a PV streamer over western Europe that was responsible for the heavy precipitation. The two anticyclonic systems then merged and formed a persistent blocking over the northern

  11. Lag-Correlation analysis of the April 2013 flood event in Argentina

    NASA Astrophysics Data System (ADS)

    Alvizurez, J. J.; Kraatz, S. G.; Tesfagiorgis, K. B.

    2013-12-01

    Floods are one of the major causes for damages and loss of life around the world. In the United States alone the average of fatalities from 1977 to 2006 is 99 people per year. The ability to globally monitor flood events as they unfold, makes it possible to assess their impacts more accurately, even if the floods occur in remote regions. Our case study is a flood event in Argentina, which occurred during April 2013. It caused about 530.4 million pesos ($104 million) in damages and at least 51 deaths. The severity of flood events mainly depends on precipitation and soil moisture. Scientists at NOAA-CREST have recently developed a daily global flood observation system in an effort to monitor global floods accurately. The developed flood observation system is based on the concept of Soil Wetness Variation Index (SWVI). The lag correlation between precipitation and SWVI is studied. Precipitation data was obtained from Tropical Rainfall Measuring Mission (TRMM) 3B42v7, TRMM-adjusted merged-infrared(IR) precipitation data set. The SWVIs data used for flooding observation are calculated from data (Brightness Temperature) collected by Advanced Technology Microwave Sounder (ATMS), on board of Soumi-NPP. Results indicate a lag-correlation of 2 to 6 days.

  12. Atmospheric Rivers and Floods: Diagnosis and Prediction for events in France

    NASA Astrophysics Data System (ADS)

    Schwarz, T.; Lu, M.; Lall, U.

    2012-12-01

    Extreme flood events, especially those induced by persistent heavy precipitation are investigated from a climate perspective. Of interest are the moisture sources for the antecedent and event precipitation, the circulation patterns associated with the convergence of moisture and the climate teleconnections for the flood/extreme precipitation occurrence. We focus on extreme flood events over France since 1952. First, we investigate the seasonality and spatial pattern of these events and the associated atmospheric rivers. Second, the Gulf of Mexico and warm oceanic areas east to the Bahamas are identified as the major moisture sources for those heavy precipitation/extreme floods events in France. The leading components from a singular value decomposition analysis of atmospheric fields reveal that an anomalous low pressure field develops before the onset of heavy rainfall and persists through the heavy precipitation period. Third, a statistical model is developed to predict the daily precipitation associated with the extreme flooding events, at multi-day lead times. In summary, a diagnostic analysis of the extreme floods reveals moisture sources, organized moisture transport as atmospheric rivers, and associated circulation mechanisms that lead to the steering and landfall of these rivers, and these provide multi-day predictive ability for extreme flood occurrence in the region.

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

    PubMed

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

    2015-06-01

    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. PMID:25710622

  14. 100 Years of the Physics of Diodes

    NASA Astrophysics Data System (ADS)

    Luginsland, John

    2013-10-01

    The Child-Langmuir Law (CL), discovered 100 years ago, gives the maximum current that can be transported across a planar diode in the steady state. As a quintessential example of the impact of space-charge shielding near a charged surface, it is central to the studies of high current diodes, such as high power microwave sources, vacuum microelectronics, electron and ion sources, and high current drivers used in high-energy density physics experiments. CL remains a touchstone of fundamental sheath physics, including contemporary studies of nano-scale quantum diodes and plasmonic devices. Its solid state analog is the Mott-Gurney law, governing the maximum charge injection in solids, such as organic materials and other dielectrics, which is important to energy devices, such as solar cells and light-emitting diodes. This paper reviews the important advances in the physics of diodes since the discovery of CL, including virtual cathode formation and extension of CL to multiple dimensions, to the quantum regime, and to ultrafast processes. We will review the influence of magnetic fields, multiple species in bipolar flow, electromagnetic and time dependent effects in both short pulse and high frequency THz limits, and single electron regimes. Transitions from various emission mechanisms (thermionic, field, and photo-emission) to the space charge limited state (CL) will be addressed, especially highlighting important simulation and experimental developments in selected contemporary areas of study. This talk will stress the fundamental physical links between the physics of beams to limiting currents in other areas, such as low temperature plasmas, laser plasmas, and space propulsion. Also emphasized is the role of non-equilibrium phenomena associated with materials and plasmas in close contact. Work supported by the Air Force Office of Scientific Research.

  15. Flood events across the North Atlantic region - past development and future perspectives

    NASA Astrophysics Data System (ADS)

    Matti, Bettina; Dieppois, Bastien; Lawler, Damian; Dahlke, Helen E.; Lyon, Steve W.

    2016-04-01

    Flood events have a large impact on humans, both socially and economically. An increase in winter and spring flooding across much of northern Europe in recent years opened up the question of changing underlying hydro-climatic drivers of flood events. Predicting the manifestation of such changes is difficult due to the natural variability and fluctuations in northern hydrological systems caused by large-scale atmospheric circulations, especially under altered climate conditions. Improving knowledge on the complexity of these hydrological systems and their interactions with climate is essential to be able to determine drivers of flood events and to predict changes in these drivers under altered climate conditions. This is particularly true for the North Atlantic region where both physical catchment properties and large-scale atmospheric circulations have a profound influence on floods. This study explores changes in streamflow across North Atlantic region catchments. An emphasis is placed on high-flow events, namely the timing and magnitude of past flood events, and selected flood percentiles were tested for stationarity by applying a flood frequency analysis. The issue of non-stationarity of flood return periods is important when linking streamflow to large-scale atmospheric circulations. Natural fluctuations in these circulations are found to have a strong influence on the outcome causing natural variability in streamflow records. Long time series and a multi-temporal approach allows for determining drivers of floods and linking streamflow to large-scale atmospheric circulations. Exploring changes in selected hydrological signatures consistency was found across much of the North Atlantic region suggesting a shift in flow regime. The lack of an overall regional pattern suggests that how catchments respond to changes in climatic drivers is strongly influenced by their physical characteristics. A better understanding of hydrological response to climate drivers is

  16. ENSO and disaster: droughts, floods and El Niño/Southern Oscillation warm events.

    PubMed

    Dilley, M; Heyman, B N

    1995-09-01

    The connection between El Niño/Southern Oscillation (ENSO) events and precipitation and temperature variability worldwide is increasingly well understood. ENSO has been linked to droughts and flooding in some regions. This paper uses the disaster history database of the U.S. Agency for International Development's Office of U.S. Foreign Disaster Assistance to examine the link between ENSO events and droughts or floods of sufficient magnitude to trigger international disasters. Worldwide, disasters triggered by droughts are twice as frequent during year two of ENSO warm events than during other years. No such relationship is apparent in the case of flood disasters. Drought disasters occur during year two of ENSO warm events significantly more frequently than in other years in Southern Africa and Southeast Asia. No regional pattern emerges from a comparable analysis of flood disasters. Those places likely to be affected by ENSO-triggered droughts can take proactive measures to mitigate the impacts. PMID:7552108

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

    EPA Science Inventory

    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...

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

    NASA Astrophysics Data System (ADS)

    Bouilloud, Ludovic; Delrieu, Guy; Boudevillain, Brice; Kirstetter, Pierre-Emmanuel

    2010-11-01

    SummaryA method to estimate rainfall from radar data for post-event analysis of flash-flood events has been developed within the EC-funded HYDRATE project. It follows a pragmatic approach including careful analysis of the observation conditions for the radar system(s) available for the considered case. Clutter and beam blockage are characterised by dry-weather observations and simulations based on a digital terrain model of the region of interest. The vertical profile of reflectivity (VPR) is either inferred from radar data if volume scanning data are available or simply defined using basic meteorological parameters (idealised VPR). Such information is then used to produce correction factor maps for each elevation angle to correct for range-dependent errors. In a second step, an effective Z-R relationship is optimised to remove the bias over the hit region. Due to limited data availability, the optimisation is carried out with reference to raingauge rain amounts measured at the event time scale. Sensitivity tests performed with two well-documented rain events show that a number of Z = aRb relationships, organised along hyperbolic curves in the (a and b) parameter space, lead to optimum assessment results in terms of the Nash coefficient between the radar and raingauge estimates. A refined analysis of these equifinality patterns shows that the “total additive conditional bias” can be used to discriminate between the Nash coefficient equifinal solutions. We observe that the optimisation results are sensitive to the VPR description and also that the Z-R optimisation procedure can largely compensate for range-dependent errors, although this shifts the optimal coefficients in the parameter space. The time-scale dependency of the equifinality patterns is significant, however near-optimal Z-R relationships can be obtained at all time scales from the event time step optimisation.

  19. ANALYSIS ON RECENT FLOOD EVENTS AND TREE VEGETATION COLLAPSES IN KAKO RIVER

    NASA Astrophysics Data System (ADS)

    Michioku, Kohji; Miyamoto, Hitoshi; Kanda, Keiichi; Ohchi, Yohei; Aga, Kazuho; Morioka, Jyunji; Uotani, Takuya; Yoshida, Kazuaki; Yoshimura, Satoshi

    Forestation on flood plains is a world-wide engineering issue in middle to downstream reaches in many rivers. This brings not only degradation of flow conveyance capacity but also irreversible changes of ecological system in rivers. In order to obtain information on tree vegetation behavior during flood events, field data of flow fields and tree vegetation collapse were collected in Kako River, where willows are heavily vegetated on the flood plain. After starting a H-ADCP flow measurement in 2009, small to medium size flood events frequently occurred, which enables us not only to verify an analytical model to reproduce flow fields in and out of vegetations but also to examine tree vegetation collapses after flooding. The analytical solutions on velocity profiles as well as flow force acting on trees were in good agreement with the H-ADCP measurements and tree damages, respectively.

  20. River flood events in Thailand and Bangladesh observed by CryoSat

    NASA Astrophysics Data System (ADS)

    Andersen, O. B.; Nielsen, K.; Villadsen, H.; Stenseng, L.; Knudsen, P.

    2014-12-01

    The high along track resolution of the SIRAL altimeter carried on-board CryoSat-2 offers a wide range of unique opportunities for satellite monitoring of inland water level. This study focuses on the ability of CryoSat-2 to detect the effects of flood events such as increased river levels and inundation of land. Here we study two flood events; the Bangladesh flood event of June 2012 and the flooding in Thailand that lasted between July 2011 and January 2012. The flooding in these areas was caused by abnormal monsoonal rainfall and affected millions of people. We process CryoSat-2 level 1b SAR mode data to derive water levels for the areas and compare these levels before, during and after the flooding events. Other parameters such as the backscatter coefficient and pulse peakiness are also considered. To verify the extent of the flooding observed by CryoSat-2 we compare with independent sources such as Landsat images.

  1. Progress of Cometary Science in the Past 100 Years

    NASA Technical Reports Server (NTRS)

    Sekanina, Zdenek

    1999-01-01

    Enormous strides made by cometary science during the 20th century defy any meaningful comparison of its state 100 years ago and now. The great majority of the subfields enjoying much attention nowadays did not exist in the year 1900. Dramatic developments, especially in the past 30-50 years, have equally affected observational and theoretical studies of comets. The profound diversification of observing techniques has been documented by the ever widening limits on the electromagnetic spectrum covered. While the time around 1900 marked an early period of slow and painful experimentation with photographic methods in cometary studies, observations of comets from the x-ray region to the radio waves have by now become routine. Many of the new techniques, and all those involved with the wavelengths shorter than about 300 nm, were made possible by another major breakthrough of this century - observing from space. Experiments on dedicated Earth-orbiting satellites as well as several deep-space probes have provided fascinating new information on the nature and makeup of comets. In broader terms, much of the progress has been achieved thanks to fundamental discoveries and major advances in electronics, whose applications resulted in qualitatively new instruments (e.g. radiotelescopes) and sensors or detectors (e.g. CCD arrays). The most universal effect on the entire cometary science, from observing to data handling to quantitative interpretations, has been, as in any other branch of science, due to the introduction of electronic computers, with their processing capabilities not only unheard of, but literally unimaginable, in the age of classical desk calculators. As if all this should not be enough, the today's generations of comet scientists have, in addition, been blessed with nature's highly appreciated cooperation. Indeed, in the span of a dozen years, between 1985 and 1997, we were privileged to witness four remarkable cometary events: (i) a return of Halley

  2. Seasonality analysis of hydrological characteristics and flash flood events in Greece

    NASA Astrophysics Data System (ADS)

    Koutroulis, A. G.; Tsanis, I. K.

    2009-04-01

    The seasonality of flash flood occurrence is strongly connected to the climate forcing mechanisms of each region. Hydrological characteristics such as precipitation and stream flow depict the regional climate mechanisms. Comparison of daily and mean monthly seasonality of selected precipitation and runoff characteristics reveals valuable information within the context of flood occurrence. The present study presents the preliminary findings of the seasonality analysis of flash flood events that occurred in Greece during the 1925 - 2007 period in combination with a seasonality analysis of their hydrological characteristics. A two level approach at national (Greece) and regional (Crete Island) level was followed, using a total of 206 flood events. Twenty two of these flood events enriched the European Flash Flood database, which is being developed in the HYDRATE project. The analysis of hydrological characteristics through seasonality indices was based on a dataset of 83 monthly and daily precipitation stations and additionally 22 monthly and 15 daily flow stations. Analysis concludes that on the island of Crete, the flood event-based seasonality coincides with the seasonality of the daily precipitation maxima during December and January. The seasonality of the 3 largest long term daily precipitation maxima indicates that 50% of the maximum precipitation events occur during and the November -December - January (NDJ) period. The event based seasonality analysis for Greece indicated that 57% of the events occur during the NDJ period. The annual maximum daily precipitation is lagging behind by approximately one month to the maximum annual stream flows for Crete. This is due to the snow melting process, the low soil percolation rates of winter period and the high baseflow of the local karstic aquifers that contribute to the maximum flows. The results will be compared with six different hydrometeorological regions within Europe in the frame of HYDRATE project, in order to

  3. Geomorphic Change in Two Historical Flood Events on the Umatilla River, Oregon

    NASA Astrophysics Data System (ADS)

    McDowell, P. F.; Hughes, M. L.; Marcus, W. A.

    2003-12-01

    We mapped geomorphic change in an 80-km length of the active channel and floodplain of the Umatilla River for two flood events, 1965 and 1996/1997, both about 20 to 70-yr events. More artificial bank stabilization structures were in place during the 1996-7 cluster. We scanned and georectified pre- and post-flood aerial photos, achieving RMSE of 1.5 to 3m, and we digitized channel and floodplain features. Sinuosity generally decreased, and the scour zone and active bars increased in each flood. Secondary channels were created or reactivated. Changes were smaller during the 1996-7 flood cluster, due partly to increased bank protection. In both floods, geomorphic change was spatially variable and related to local influences (tributary junctions, human influences) as well as landscape-scale controls (downstream trends in alluvial deposit characteristics and incision). Both flood events increased areas of several types of features important for fish habitat and water quality, such as alcoves and riparian woody vegetation. Where human influences such as bank protection severely limit geomorphic change, floods can no longer renew habitat and ecological health may decline over time.

  4. Predicting the Geomorphic and Aquatic Habitat Effects of Extreme Flood Events

    NASA Astrophysics Data System (ADS)

    Tamminga, A.; Eaton, B. C.

    2014-12-01

    High magnitude flood events can completely restructure fluvial systems and condition subsequent geomorphic and ecological regimes. The effects of such disturbances depend on factors such as existing morphology, flood magnitude and duration, and sediment supply. However, the inherent rarity of large floods makes untangling potential controls and interactions difficult. In this study, we take advantage of complete high resolution topographic and air photo data sets collected with unmanned aerial vehicle (UAV) based remote sensing to assess the reach-scale effects of catastrophic flooding that occurred in Alberta, Canada in June 2013. In particular, we combine 2D flow models with pre- and post-flood topographies to constrain the range of conditions during high flow on two rivers, and then relate these conditions to observed changes. We find that flooding on the Elbow River led to a complete channel restructuring associated with tractive forces well above thresholds for sediment transport, whereas the Kananaskis River experienced less drastic change and maintained its channel pattern. Consequently, morphodynamics are more reliably predicted using pre-flood data for the Kananaskis River. Physical changes are then related to in-stream hydraulic habitat, and implications for post-flood channel readjustment are discussed. This work provides a detailed analysis of relationships between flooding, channel morphology, and aquatic habitat in two contrasting systems, with implications for predictive capacity and stream ecosystem management.

  5. Detecting flood event trends assigned to changes in urbanisation levels using a bivariate copula model

    NASA Astrophysics Data System (ADS)

    Requena, Ana; Prosdocimi, Ilaria; Kjeldsen, Thomas R.; Mediero, Luis

    2014-05-01

    Flood frequency analyses based on stationary assumptions are usually employed for estimating design floods. However, more complex non-stationarity approaches are trying to be incorporated with the aim of improving such estimates. In this study, the effect of changing urbanisation on maximum flood peak (Q) and volume (V) series is analysed. The potential changes in an urbanised catchment and in a nearby hydrologically similar rural catchment in northwest England are investigated. The urbanised catchment is characterised by a noticeable increase of the urbanisation level in time, while the rural catchment has not been altered by anthropogenic actions. Winter, summer and annual maximum flood events are studied. With the aim of analysing changes in time, two non-superimposed time-windows are defined covering the periods 1976-1992 and 1993-2008, respectively. A preliminary analysis of temporal trends in Q, V and Kendall's tau is visually done, being formal tested by a resampling procedure. Differences were found among winter, summer and annual maximum flood events. As annual maximum flood events are commonly used for designing purposes, the corresponding bivariate distribution (margins and copula) was obtained for the different time-windows. Trends regarding both time-windows were analysed by comparing bivariate return period curves in the Q-V space. Different behaviours were found depending on the catchment. As a result, the application of the proposed methodology provides useful information in describing changes in flood events, regarding different flood variables and their relationship. In addition, the methodology can inform practitioners on the potential changes connected with urbanisation for appropriate design flood estimation.

  6. Simulating and Forecasting Flooding Events in the City of Jeddah, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Ghostine, Rabih; Viswanadhapalli, Yesubabu; Hoteit, Ibrahim

    2014-05-01

    Metropolitan cities in the Kingdom of Saudi Arabia, as Jeddah and Riyadh, are more frequently experiencing flooding events caused by strong convective storms that produce intense precipitation over a short span of time. The flooding in the city of Jeddah in November 2009 was described by civil defense officials as the worst in 27 years. As of January 2010, 150 people were reported killed and more than 350 were missing. Another flooding event, less damaging but comparably spectacular, occurred one year later (Jan 2011) in Jeddah. Anticipating floods before they occur could minimize human and economic losses through the implementation of appropriate protection, provision and rescue plans. We have developed a coupled hydro-meteorological model for simulating and predicting flooding events in the city of Jeddah. We use the Weather Research Forecasting (WRF) model assimilating all available data in the Jeddah region for simulating the storm events in Jeddah. The resulting rain is then used on 10 minutes intervals to feed up an advanced numerical shallow water model that has been discretized on an unstructured grid using different numerical schemes based on the finite elements or finite volume techniques. The model was integrated on a high-resolution grid size varying between 0.5m within the streets of Jeddah and 500m outside the city. This contribution will present the flooding simulation system and the simulation results, focusing on the comparison of the different numerical schemes on the system performances in terms of accuracy and computational efficiency.

  7. Applications of flood depth from rapid post-event footprint generation

    NASA Astrophysics Data System (ADS)

    Booth, Naomi; Millinship, Ian

    2015-04-01

    Immediately following large flood events, an indication of the area flooded (i.e. the flood footprint) can be extremely useful for evaluating potential impacts on exposed property and infrastructure. Specifically, such information can help insurance companies estimate overall potential losses, deploy claims adjusters and ultimately assists the timely payment of due compensation to the public. Developing these datasets from remotely sensed products seems like an obvious choice. However, there are a number of important drawbacks which limit their utility in the context of flood risk studies. For example, external agencies have no control over the region that is surveyed, the time at which it is surveyed (which is important as the maximum extent would ideally be captured), and how freely accessible the outputs are. Moreover, the spatial resolution of these datasets can be low, and considerable uncertainties in the flood extents exist where dry surfaces give similar return signals to water. Most importantly of all, flood depths are required to estimate potential damages, but generally cannot be estimated from satellite imagery alone. In response to these problems, we have developed an alternative methodology for developing high-resolution footprints of maximum flood extent which do contain depth information. For a particular event, once reports of heavy rainfall are received, we begin monitoring real-time flow data and extracting peak values across affected areas. Next, using statistical extreme value analyses of historic flow records at the same measured locations, the return periods of the maximum event flow at each gauged location are estimated. These return periods are then interpolated along each river and matched to JBA's high-resolution hazard maps, which already exist for a series of design return periods. The extent and depth of flooding associated with the event flow is extracted from the hazard maps to create a flood footprint. Georeferenced ground, aerial

  8. Hydro-Meteocean Nature of some Extreme Flood Events and Some Consequences

    NASA Astrophysics Data System (ADS)

    Diez, J. Javier

    2013-04-01

    The Santa Irene flood event, at the end of October 1982, is one of the most dramatically widely reported flood events in Spain. Its renown is mainly due to the collapse of the Tous dam, but its main message is to be the paradigm of the incidence of the maritime/littoral weather and its temporal sea level rise on the coastal plains inland floods. Looking at damages the paper analyzes the adapted measures from the point of view of the aims of the FP7 SMARTeST Project related to the Flood Resilience improvement in urban areas through looking for Technologies, Systems and Tools an appropriate "road to de market". The event, as frequently, was due to a meteorological phenomenon known as "gota fría" (cold drop), a relatively frequent and intense rainy phenomenon on the Iberian Peninsula, particularly on the Spanish east to southeast inlands and coasts. There are some circumstances that can easily come together to unleash the cold drop there: cold and dry polar air masses coming onto the whole Iberian Peninsula and the north of Africa, high sea water temperatures, and low atmospheric pressure (cyclone) areas in the western Mediterranean basin; these circumstances are quite common during the autumn season there, and, as it happens, in other places around the world (East/Southeast Africa). Their occurrence, however shows a great space-temporal variability (in a similar way to hurricanes, on Caribbean and western North-Atlantic areas, or to typhoons do). As a matter of fact, all of these equivalent though different phenomena may have different magnitude each time. This paper describes the results of a detailed analysis and reflection about this cold drop phenomenon as a whole, on the generation of its rains and on the different natures and consequences of its flood. This paper explains also the ways in which the maritime weather in front of the basin and the consequent sea level govern floods on the lowest zone of any hydrographical basin, showing that event as a real

  9. Controls on Flood Event Frequencies Recorded in Stalagmites from Cave KNI-51, Australian Tropics

    NASA Astrophysics Data System (ADS)

    Denniston, Rhawn; Gonzales, Angelique; Villarini, Gabriele; Polyak, Victor; Asmerom, Yemane; Wanamaker, Alan, Jr.; Lachniet, Matthew; Ummenhofer, Caroline; Cugley, John; Woods, David; Humphreys, William

    2016-04-01

    Extreme rainfall events in the central Australia tropics are largely driven by tropical cyclones and the Australian summer monsoon, both of which are sensitive to external forcing. To better understand baseline variability in extreme rainfall, we produced a record of cave flooding events spanning the last two millennia from a suite of precisely-dated and fast-growing aragonite stalagmites from cave KNI-51 (Denniston et al., 2015, PNAS, 112, 4576). During cave flooding events, sediment deposited on stalagmite surfaces becomes preserved within the stalagmite when floodwaters recede and stalagmite growth resumes. Ages of individual flood events are determined using growth models constructed from linear interpolation of 230Th-dated intervals of stalagmite carbonate (2 s.d. errors of ±1-30 yr in most cases). The robustness of this stalagmite flood record was tested, in part, by comparing accumulations of sediment layers in coeval stalagmites. Absolute values and temporal trends in flood recurrence rates were generally quite similar between stalagmites, arguing that each stalagmite was equally sensitive to flood events. We have now extended this cave flooding record back to 3600 yr BP using three additional stalagmites, each of which contains multi-decadal to centennial variations in flood frequency. The longest duration (1000 yr) and tallest (1.1m) of these stalagmites, KNI-51-7, is marked by a secular trend toward reduced flood occurrence rates, with the 30 yr running mean of floods/yr reaching 0.0, a value lower than in any other of the other nine samples analyzed in this study. However, KNI-51-N, which overlaps with KNI-51-7 for 300 yr, contains nearly identical sub-centennial variations to KNI-51-7 but KNI-51-N does not trend toward lower values. We argue that the decreasing average number of flood events with time in KNI-51-7 is a result of the stalagmite having grown above average flood height, thereby restricting its ability to record more frequent, smaller

  10. Estimating Flood Quantiles on the Basis of Multi-Event Rainfall Simulation - Case Study

    NASA Astrophysics Data System (ADS)

    Jarosińska, Elżbieta; Pierzga, Katarzyna

    2015-12-01

    This paper presents an approach to estimating the probability distribution of annual discharges Q based on rainfall-runoff modelling using multiple rainfall events. The approach is based on the prior knowledge about the probability distribution of annual maximum daily totals of rainfall P in a natural catchment, random disaggregation of the totals into hourly values, and rainfall-runoff modelling. The presented Multi-Event Simulation of Extreme Flood method (MESEF) combines design event method based on single-rainfall event modelling, and continuous simulation method used for estimating the maximum discharges of a given exceedance probability using rainfall-runoff models. In the paper, the flood quantiles were estimated using the MESEF method, and then compared to the flood quantiles estimated using classical statistical method based on observed data.

  11. 3D Simulation of External Flooding Events for the RISMC Pathway

    SciTech Connect

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

    2015-09-01

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

  12. Incorporating seasonality into event-based joint probability methods for predicting flood frequency: A hybrid causative event approach

    NASA Astrophysics Data System (ADS)

    Li, Jing; Thyer, Mark; Lambert, Martin; Kuzera, George; Metcalfe, Andrew

    2016-02-01

    Flood extremes are driven by highly variable and complex climatic and hydrological processes. Observational evidence has identified that seasonality of climate variables has a major impact on flood peaks. However, event-based joint probability approaches for predicting the flood frequency distribution (FFD), which are commonly used in practice, do not commonly incorporate climate seasonality. This study presents an advance in event-based joint probability approaches by incorporating seasonality using the hybrid causative events (HCE) approach. The HCE was chosen because it uses the true causative events of the floods of interest and is able to combine the accuracy of continuous simulation with the computational efficiency of event-based approaches. The incorporation of seasonality is evaluated using a virtual catchment approach at eight sites over a wide range of Australian climate zones, including tropical, temperature, Mediterranean and desert climates (virtual catchment data for the eight sites is freely available via digital repository). The seasonal HCE provided accurate predictions of the FFD at all sites. In contrast, the non-seasonal HCE significantly over-predicted the FFD at some sites. The need to include seasonality was influenced by the magnitude of the seasonal variation in soil moisture and its coherence with the seasonal variation in extreme rainfall. For sites with a low seasonal variation in soil moisture the non-seasonal HCE provided reliable estimates of the FFD. For the remaining sites, it was found difficult to predict a priori whether ignoring seasonality provided a reliable estimate of the FFD, hence it is recommended that the seasonal HCE always be used. The practical implications of this study are that the HCE approach with seasonality is an accurate and efficient event-based joint probability approach to derive the flood frequency distribution across a wide range of climatologies.

  13. Performance Evaluation of a NEXRAD-Based Flood Warning during Recent Events in 2012

    NASA Astrophysics Data System (ADS)

    Fang, N.; Bedient, P.

    2012-12-01

    More weather radar applications have been used to provide accurate precipitation information for flood warning purposes because radar tends to have wider spatial and temporal coverage over the conventional monitoring networks. Thus the radar-based flood warning systems as great tools have become more prevalent in the past decades to provide the information necessary to mobilize the evacuation of people and property prior to flooding in critical areas The Rice University and the Texas Medical Center (TMC) Flood Alert System (FAS) has been providing important warning information for the critical medical facilities for more than 40 events since 1997. The current FAS utilizes NEXRAD Level II radar rainfall data coupled with a real-time hydrologic model (RTHEC-1) to deliver warning information with 2 to 3 hours of lead time and a forecast R2 value of 93% to facility personnel in readily understood format. The latest version - FAS3 has a user-friendly dashboard to provide rainfall maps, Google Maps based inundation maps, hydrologic predictions, and real-time monitoring at the bayou. This paper will discuss its reliable performance during the recent events occurring in 2012. Due to its excellent performance, Texas Medical Center has included FAS3 into their FEMA Success Story as a good example to demonstrate the significant value of the radar-based flood warning system. Currently, the radar-based flood alert system has been used as a platform to develop for other flood-prone areas in Texas.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    Retsö, D.

    2014-09-01

    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 subperiods can be considered as flood-rich, 1590-1670 and the early 18th century. The result is related to a low degree of human impact on hydrology during the period, and suggest that climatic factors, such as lower temperatures and increased precipitation connected to the so called Little Ice Age, should be considered as the main driver behind flood frequency and magnitude.

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

    NASA Astrophysics Data System (ADS)

    Battiston, Stéphanie; Allenbach, Bernard

    2010-05-01

    The exceptional characteristics of the December 2003 Rhône flood event (particularly high water flows, extent of the affected area, important damages especially in the region of Arles) make it be considered as a reference flood episode of this French river and a very well-known event. During the crisis, the International Charter "Space and Major Disasters" was triggered by the French Civil Protection for the rapid mapping of the flooding using Earth Observation imagery in order to facilitate crisis operations. As a result, more than 60 satellite images covering the flood were acquired over a 10 days period following the peak flow. Using the opportunity provided by this incomparable data coverage, the French Ministry of the Environment ordered a study on the evaluation of remote sensing's potential benefits for flood management. One of the questions asked by the risk managers was: what type of flood information can be provided by the different remote sensing platforms? Elements of response were delivered mainly in the form of a comprehensive compilation of maps and illustrations, displaying the main hydraulic elements (static ones as well as dynamic ones), initially listed and requested by hydrologists (more precisely, by a regional engineering society specialised in hydraulics and hydrology and in charge of a field campaign during the event), observed on different optical images of the flood event having affected the plain between Tarascon (upstream) and Arles (downstream). It is seen that a careful mapping of all flood traces visible on remote sensing event imagery - apparent water, moisture traces, breaches, overflows, stream directions, impermeable boundaries … - delivers a valuable vision of the flood's occurrence combining accuracy and comprehensiveness. In fact, optical imagery offers a detailed vision of the event : moisture traces complete flood traces extent; the observation of draw-off directions through waterproof barriers reveals hydraulic

  17. Testing the use of viscous remanent magnetisation to date flood events

    NASA Astrophysics Data System (ADS)

    Muxworthy, Adrian; Williams, Jason; Heslop, David

    2015-01-01

    Using erratics associated with large flood events, this paper assesses whether their viscous remanent magnetisation (VRM) can be used to date the flood events. We tested this method using flood erratics from three large events: (1) the Late Pleistocene Bonneville mega-flood in Idaho, USA, (~14-18 ka), (2) the 1918 A.D. Mt. Katla, Iceland, eruption and associated jökulhaup (meltwater flood) at Mýrdalssandur, and (3) the Markarfljót jökulhaup due to an earlier eruption of Mt. Katla (~2.5 ka). We measured 236 specimens, 66 of which yielded clear identifiable and measurable viscous magnetisation signals from erratics with clustered VRM directions. From the VRM unblocking temperatures, age estimates were made. The age estimate for the most recent event (Mýrdalssandur) worked well, with a median estimated age of 80 years (with individual erratic estimates distributed between 61 - 105 years) compared to the known age of 91 years. The ages of the other two events were over-estimated. The estimates for Markarfljót (15 ka (7 - 33 ka)) were based on the results of just one erratic. For the Bonneville flood the estimates were too old, however, this locality had the largest uncertainty in the ambient temperature used in the age determination; the VRM acquired is strongly dependent on the ambient temperature, the older the event the greater the uncertainty. Southern Idaho currently has hot summers, with average summer maximum temperatures of ~31 ˚C, but a mean annual temperature of only ~ 9 ˚C. It is suggested that the VRM dating method works best for recent events (< 2-3 ka) where the ambient temperature history can be constrained.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Evidence of multiple flooding events or pulses from erosional features in Martian outflow channels

    NASA Astrophysics Data System (ADS)

    Davatzes, A.; Gulick, V.; Keszthelyi, L.; HiRISE Team

    2007-12-01

    Cataracts, steep knickpoints in large outflow channels, were once large waterfalls on the martian surface. New images of cataracts in the Kasei, Ares, and Mangala Valles obtained by the High Resolution Imaging Science Experiment (HiRISE) onboard the Mars Reconnaissance Orbiter (MRO) in conjunction with topography from the Mars Orbiter Laser Altimeter (MOLA) are used to further constrain channel outflow rates and durations. Both the morphology and geometry of these erosional features help us to further elucidate the history of these outflow channels. Morphologically, all of the cataract systems have horseshoe-shaped headcuts and longitudinal grooves. These morphological features are strikingly similar to terrestrial flood erosional features from the Missoula Flood, Jokulsa a Fjollum, and English Channel flood. Like terrestrial cataracts, the Martian cataracts have significantly lower width-to-depth ratios compared to the rest of the channel, consistent with erosion into bedrock. Knickpoint recession is also evident from these images. The Ares Valles cataract has migrated more than 35 km, an order of magnitude more than the terrestrial examples of catastrophic floods. Most estimates from Ares Vallis suggest similar discharge rates to the terrestrial floods, though some estimates of Martian flood discharge are significantly higher. High resolution imaging shows that nearly all of the cataract systems have multiple generations of erosion, with smaller subchannels within the cataract system. Based on the length of the recession and the morphological evidence, multiple flooding events are possible in most of these Martian channels, either by discrete events or pulses of flow. All of the terrestrial examples resulted from the breaching of a rock or ice dam, releasing a glacial flood. Most of the Martian outflow channel discharges likely came from the subsurface. DEM's of these cataracts from HiRISE and CTX stereo pairs will be input into a 2.5D hydraulic flood model to

  20. Flood-Producing Rainfall and Storm Event Hydrologic Response in Urban Watersheds near Baltimore, MD

    NASA Astrophysics Data System (ADS)

    Smith, B. K.; Smith, J. A.; Baeck, M. L.; Villarini, G.

    2012-12-01

    Previous work has shown a spectrum of storm event hydrologic response across watersheds in the Baltimore, MD metropolitan area. Differences in storm event hydrologic response between urban basins cannot be explained by impervious surface or land use alone. We further explore these differences through a closer look at flood-producing rainfall properties and through numerical experimentation using a watershed model. Rainfall analyses utilize a high resolution radar rainfall dataset (1-km and 15-min resolution, processed through Hydro-NEXRAD and bias corrected) for a ten-year period from 2000-2009. Spatial heterogeneities in flood-producing rainfall suggest that some urban basins may be more prone to flooding due to higher rainfall intensities over the basin. For example, Moores Run, the flashiest basin in the contiguous United States, is located near a rainfall maximum to the northeast of Baltimore. Spatial patterns of flood-producing rainfall vary between urban and non-urban basins. We examine contrasts in storm structure and evolution for storms producing flood in urban and non-urban watersheds. Storm event hydrologic response is examined through analyses using a watershed model of the Dead Run basin based on the Gridded Surface/ Subsurface Hydrologic Analysis (GSSHA) model. The model is used to explore the sensitivity of urban storm event hydrologic response to properties of urban soils, surface and storm drain network structure, and detention basin storage.

  1. Erosion during extreme flood events dominates Holocene canyon evolution in northeast Iceland

    PubMed Central

    Baynes, Edwin R. C.; Attal, Mikaël; Kirstein, Linda A.; Dugmore, Andrew J.; Naylor, Mark

    2015-01-01

    Extreme flood events have the potential to cause catastrophic landscape change in short periods of time (100 to 103 h). However, their impacts are rarely considered in studies of long-term landscape evolution (>103 y), because the mechanisms of erosion during such floods are poorly constrained. Here we use topographic analysis and cosmogenic 3He surface exposure dating of fluvially sculpted surfaces to determine the impact of extreme flood events within the Jökulsárgljúfur canyon (northeast Iceland) and to constrain the mechanisms of bedrock erosion during these events. Surface exposure ages allow identification of three periods of intense canyon cutting about 9 ka ago, 5 ka ago, and 2 ka ago during which multiple large knickpoints retreated large distances (>2 km). During these events, a threshold flow depth was exceeded, leading to the toppling and transportation of basalt lava columns. Despite continuing and comparatively large-scale (500 m3/s) discharge of sediment-rich glacial meltwater, there is no evidence for a transition to an abrasion-dominated erosion regime since the last erosive event because the vertical knickpoints have not diffused over time. We provide a model for the evolution of the Jökulsárgljúfur canyon through the reconstruction of the river profile and canyon morphology at different stages over the last 9 ka and highlight the dominant role played by extreme flood events in the shaping of this landscape during the Holocene. PMID:25675484

  2. Erosion during extreme flood events dominates Holocene canyon evolution in northeast Iceland.

    PubMed

    Baynes, Edwin R C; Attal, Mikaël; Niedermann, Samuel; Kirstein, Linda A; Dugmore, Andrew J; Naylor, Mark

    2015-02-24

    Extreme flood events have the potential to cause catastrophic landscape change in short periods of time (10(0) to 10(3) h). However, their impacts are rarely considered in studies of long-term landscape evolution (>10(3) y), because the mechanisms of erosion during such floods are poorly constrained. Here we use topographic analysis and cosmogenic (3)He surface exposure dating of fluvially sculpted surfaces to determine the impact of extreme flood events within the Jökulsárgljúfur canyon (northeast Iceland) and to constrain the mechanisms of bedrock erosion during these events. Surface exposure ages allow identification of three periods of intense canyon cutting about 9 ka ago, 5 ka ago, and 2 ka ago during which multiple large knickpoints retreated large distances (>2 km). During these events, a threshold flow depth was exceeded, leading to the toppling and transportation of basalt lava columns. Despite continuing and comparatively large-scale (500 m(3)/s) discharge of sediment-rich glacial meltwater, there is no evidence for a transition to an abrasion-dominated erosion regime since the last erosive event because the vertical knickpoints have not diffused over time. We provide a model for the evolution of the Jökulsárgljúfur canyon through the reconstruction of the river profile and canyon morphology at different stages over the last 9 ka and highlight the dominant role played by extreme flood events in the shaping of this landscape during the Holocene. PMID:25675484

  3. Uncertainty estimation of water levels for the Mitch flood event in Tegucigalpa

    NASA Astrophysics Data System (ADS)

    Fuentes Andino, D. C.; Halldin, S.; Lundin, L.; Xu, C.

    2012-12-01

    Hurricane Mitch in 1998 left a devastating flood in Tegucigalpa, the capital city of Honduras. Simulation of elevated water surfaces provides a good way to understand the hydraulic mechanism of large flood events. In this study the one-dimensional HEC-RAS model for steady flow conditions together with the two-dimensional Lisflood-fp model were used to estimate the water level for the Mitch event in the river reaches at Tegucigalpa. Parameters uncertainty of the model was investigated using the generalized likelihood uncertainty estimation (GLUE) framework. Because of the extremely large magnitude of the Mitch flood, no hydrometric measurements were taken during the event. However, post-event indirect measurements of discharge and observed water levels were obtained in previous works by JICA and USGS. To overcome the problem of lacking direct hydrometric measurement data, uncertainty in the discharge was estimated. Both models could well define the value for channel roughness, though more dispersion resulted from the floodplain value. Analysis of the data interaction showed that there was a tradeoff between discharge at the outlet and floodplain roughness for the 1D model. The estimated discharge range at the outlet of the study area encompassed the value indirectly estimated by JICA, however the indirect method used by the USGS overestimated the value. If behavioral parameter sets can well reproduce water surface levels for past events such as Mitch, more reliable predictions for future events can be expected. The results acquired in this research will provide guidelines to deal with the problem of modeling past floods when no direct data was measured during the event, and to predict future large events taking uncertainty into account. The obtained range of the uncertain flood extension will be an outcome useful for decision makers.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Flooding of the Great River during the Common Era: A Paleohydrological Record of High Magnitude Flood Events from the Central Mississippi River Valley

    NASA Astrophysics Data System (ADS)

    Williams, J. W.; Munoz, S. E.; Gruley, K. E.; Massie, A.

    2014-12-01

    Streamflow characteristics are known to be sensitive to changes in climate, but few continuous records of flooding exist to evaluate the response of hydrological systems to centennial- and millennia-scale climate changes. Here, we present sedimentary records from two oxbow lakes (Horseshoe Lake and Grassy Lake, Illinois, USA) in the central Mississippi River valley (CMRV) that display abrupt shifts in sediment composition and particle-size consistent with deposition by floodwaters immediately following inundation of the floodplain. The sedimentary record at Horseshoe Lake begins ca. AD 100 and displays five major flood events, with four of these occurring after ca. AD 1100. Situated 200 km downstream, the record from Grassy Lake begins later, ca. AD 800, and also shows four major flood events after ca. AD 1100. An analysis of synchronicity using Bayesian age modelling software shows high likelihoods that the four overlapping flood events occurred at the same time, confirming that these events resulted from flooding of the Mississippi River. The most recent event we record at AD 1840 ± 50 corresponds to the AD 1844 flood, the largest flood by discharge (37 m3/s) measured by the gauging station at St. Louis, Missouri, indicating that our sedimentary records document high magnitude flood events. Together, our two sedimentary records show a major shift in the frequency of high magnitude flooding in the central Mississippi River at ca. AD 1100. From AD 100 - AD 1100, only one relatively subtle flood event is recorded, but from AD 1100 - AD 1900, four high magnitude floods deposited distinctive sediment at both sites. The period of infrequent flooding corresponds to a time of agricultural intensification and population growth in the CMRV, while the entire region was abandoned when flood frequency increased. The pronounced shift in flood frequency we observe in our records at ca. AD 1100 begins during the Medieval Climate Anomaly (MCA; AD 950 - AD 1250), a period of

  6. Cosmo-geo-anthropo-logical history and political and deep future events in climate and life evolution conveyed by a physical/virtual installation at a scale of 1 mm per 100 years across Denmark during the COP15 climate summit meeting.

    NASA Astrophysics Data System (ADS)

    Holm Jacobsen, Bo

    2010-05-01

    During the COP15 climate summit meeting a physical and virtual installation of time was performed at a linear scale of 1 mm per 100 years. The "track of time" was carefully anchored geographically so that highlights in time history coincided with landmarks of historical and cultural significance to both tourists and the local Danish population; with Big Bang at the site of early royal settlements from the Viking age (13.7 billion years ~ 137 km from now), Earth origin at Kronborg in Elsinore (4.6 bil. Years ~ 46 km), and fish go on land at The Little Mermaid (390 mil. Years ~ 3900 m). The venue of the COP15 meeting coincided with the position of severe global warming, driven by the steady solar constant increase, to be expected 600 million years into the future. Nested in this grand track of time were the Quaternary ice-ages (2.6 mil. years ~ 26 m), human origin as species (100,000 years ~ 1 m), human history (< 10,000 years ~ 100 mm), personal life and the scope of political consequences of voting action (100 years ~ 1 mm). This installation of time involved several media. Highlights in time history and future were installed as a kml-file so that the convenient user interface of Google Earth could be utilized to provide both overview of time and understanding of details and proportions events antropo-geo-cosmo-history. Each Google Earth marker-balloon gave short explanations and linked to "on location" video-narratives. A classical printed text-folder was prepared as a tour guide for those who wanted to actually walk the Phanerozoic (~5 km). Credit-card-shaped graphs of temperature, CO2 and sealevel development and scenarios were prepared to scale for the period 4000 BP to 1000 years into the future. Along the time line from "Fish on land" to the present 3900 chalk marks were placed on the street surface, one for every metre = time span of Man as a species so far. A "NowGate" marking the present was implemented physically as a door frame, where citizens could meet

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

    NASA Astrophysics Data System (ADS)

    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

  8. Processes and Geomorphological Impacts of an Extreme Flash Flood Event in SE Spain

    NASA Astrophysics Data System (ADS)

    Hooke, J.

    2015-12-01

    A major flash flood event took place on 28 September, 2012 in SE Spain, resulting in 10 fatalities and much damage to infrastructure regionally. The flood affected long-term monitoring sites in two catchments in which morphological changes and flow dynamics of these ephemeral channels were being measured. Thus detailed data on channel state prior to the flood were available. The flood event in the Nogalte catchment was extreme in its peak flow, rate of rise and unit runoff. The catchment has steep relief and much bare soil under almond groves, resulting in high sediment supply. The channel is confined in places, but mostly wide and braided, composed of loose gravel and occupying much of the valley floor. Flow was spatially continuous, with high connectivity throughout the catchment. The flood effects were net depositional in the monitored sites, with massive sedimentation on the channel bars. Vegetation was destroyed. Bank erosion and destruction of embankments took place in some locations. Hydraulic calculations indicate very high velocities, stream power and Froude numbers. Modelling and field evidence demonstrate extremely high sediment competence and sediment loadings. The influence of the event dynamics on processes and net outcomes is discussed. The impacts are compared with other events in this and neighbouring catchments. Overall, the event in the Nogalte did not alter the morphology markedly in spite of its extreme characteristics. It is suggested that these valley floors are adapted to this type of flash flood but that flows of such force and magnitude need to be allowed for in management in such an environment.

  9. Extending dry storage of spent LWR fuel for 100 years.

    SciTech Connect

    Einziger, R. E.

    1998-12-16

    excessive creep and mechanical property changes. Postulated accident scenarios would be the same for 20-year or 100-year storage, because they are mostly governed by operational or outside events, and not by the cask or fuel. Analyses of accident scenarios during extended dry storage could be impacted by fuel and cask changes that would result from the extended period of storage. Overall, the results of this work indicate that, based on fuel behavior, spent fuel at burnups below {approximately}45 GWd/MTU can be dry stored for 100 years. Long-term storage of higher burnup fuel or fuels with newer cladding will require the determination of temperature limits based on evaluation of stress-driven degradation mechanisms of the cladding.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Flood Deposition Patterns and Channel Migration due to a 10-year flood event: the case of the Indus River flood 2010

    NASA Astrophysics Data System (ADS)

    Kettner, A. J.; Syvitski, J. P.; Overeem, I.; Brakenridge, G. R.

    2013-12-01

    Fluvial geomorphological processes evolve the landscape and are often referred to as processes that act for hundred to thousands of years before making a noticeable change in landforms. For the Indus River, landscape evolution has been intensified due to human interference. Failure in repairing its levees from previous floods led in July 2010 during a not exceptional discharge event (~10 year recurrence interval) to a large avulsion and flooding disaster that caused ~2,000 fatalities. Examining pre- and post flood maps by analyzing MODIS and ASTER-A1 data allowed us to determine the extent of sandy flood deposits and to quantify channel migration patterns. The typical pattern of inner bend deposition (due to helical flow) and outer bend erosion were less pronounced. We hypothesize that when flow exceeds bankfull conditions, deposition is more uniform and no longer constrained by the streambed geometry. We observe that the inner and the outer river bend receive similar amounts of sandy deposits (43% versus 57% respectively). Crevasse splaying was widespread and appeared to occur as a flow stripping process again both upon the point bars as well as in river outer bends. Channel activity (defined as the areal shift of the pre- and post river centerline), sinuosity, slope and lateral sediment deposition were determined for 50km river stretches. Analyzes reveal that flood deposits extend generally less than 2 km from the main channel axis. Furthermore, channel activity correlates negatively with channel sinuosity and lateral distance of sediment deposition and positively with slope. The river channel migrated over 100's of meters during the July 2010 flood event. Lateral migration averaged ~340m along a 1000km stretch of the Indus River over a period of just 52 days. Although this discharge event was not exceptional, lateral migration was significant and deposition impacts the active river floodplain. Remarkably, most sediments are deposited downstream the large

  12. Mapping and Monitoring the 2010 Flood Event in China: Case of Poyang Lake

    NASA Astrophysics Data System (ADS)

    Huber, C.; Uribe, C.; Lai, X.; Huang, S.; Chen, X.; Yesou, H.

    2013-01-01

    During the summer 2010, China suffered of extreme events, no so far from the dramatic 1998 ones. Major lakes such as Dongting and Poyang and major Chinese rivers overflow all around the country. Upstream of the Poyang Lake, the Fuhe River flooded the Luozhen Township of Fuzhou City. A breach occurred on Changkai dike and forced to evacuate 1,32 million of people on the 21st and again on the 23th of June 2010. In Poyang Lake, this flood situation followed a drought episode during the winter 2009-2010 ; and after, this flood event involved a stagnation of water longer than usual. Thanks to the DRAGON II Wetland project, the ESA accorded a special authorization of programming ENVISAT WSM images on a high revisiting schema, every 3 to 5 days, for all 2010 summer period.

  13. Floods

    MedlinePlus

    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 ...

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  15. Event-based approach of downstream Rhône River flood regimes variability since 1982

    NASA Astrophysics Data System (ADS)

    Hénaff, Quentin; Arnaud-Fassetta, Gilles; Beltrando, Gérard

    2015-04-01

    Numerous downstream Rhône River floods have been recorded as catastrophic by French inter-ministerial order since the creation of natural disaster state recognition in 1982. Downstream Rhône River flood regimes, influenced by Mediterranean climate, are fundamentally affected by the spatio-temporal variability of rainfall events, especially in case of widespread flooding. Event-based analysis of cumulative rainfall data should allow us to characterise downstream Rhône River flood regimes variability by applying data mining methods to a spatio-temporal hydro-meteorological database. The first objective of this study is to determine if extreme rainfall events could be considered as geographical events, in other words if rainfall distribution is related to spatial processes. The proposed method is based on the measure of rainfall distribution spatial auto-correlation through the calculation of (i) Global Moran's index and (ii) the significance evaluation of that index with a z-score statistical test and its associated p-value. Secondly, cumulative rainfall data are integrated into a geo-event two-dimensional matrix: (i) cumulative rainfall per sub-catchment in row (spatial base unit) and (ii) cumulative rainfall per catastrophic event in column (temporal base unit). This matrix was co-clustered which allows simultaneous clustering of the rows (sub-catchment) and columns (events) by hierarchical clustering on principal components (HCPC) using Ward's method applying Euclidean Distance as similarity measure. Computing the Global Moran's index demonstrated a spatial aggregation tendency of rainfall distribution and the associated statistical test (z-core and p-value) noted the improbability of statistical evidence of random spatial pattern. Spatial variability of rainfall distribution is the result of two factors: rainfall event structure and rainfall event scale. The co-clustering geo-event matrix provided two co-clustering maps on two different cumulative rainfall

  16. Uncertainty estimation of simulated water levels for the Mitch flood event in Tegucigalpa

    NASA Astrophysics Data System (ADS)

    Fuentes Andino, Diana Carolina; Halldin, Sven; Keith, Beven; Chong-Yu, Xu

    2013-04-01

    Hurricane Mitch in 1998 left a devastating flood in Tegucigalpa, the capital city of Honduras. Due to the extremely large magnitude of the Mitch flood, hydrometric measurements were not taken during the event. However, post-event indirect measurements of the discharge were obtained by the U.S. Geological Survey (USGS) and post-event surveyed high water marks were obtained by the Japan International Cooperation agency (JICA). This work proposes a methodology to simulate the water level during the Mitch event when the available data is associated with large uncertainty. The results of the two-dimensional hydrodynamic model LISFLOOD-FP will be evaluated using the Generalized Uncertainty Estimation (GLUE) framework. The main challenge in the proposed methodology is to formulate an approach to evaluate the model results when there are large uncertainties coming from both the model parameters and the evaluation data.

  17. Recognition of maximum flooding events in mixed siliciclastic-carbonate systems: Key to global chronostratigraphic correlation

    USGS Publications Warehouse

    Mancini, E.A.; Tew, B.H.

    1997-01-01

    The maximum flooding event within a depositional sequence is an important datum for correlation because it represents a virtually synchronous horizon. This event is typically recognized by a distinctive physical surface and/or a significant change in microfossil assemblages (relative fossil abundance peaks) in siliciclastic deposits from shoreline to continental slope environments in a passive margin setting. Recognition of maximum flooding events in mixed siliciclastic-carbonate sediments is more complicated because the entire section usually represents deposition in continental shelf environments with varying rates of biologic and carbonate productivity versus siliciclastic influx. Hence, this event cannot be consistently identified simply by relative fossil abundance peaks. Factors such as siliciclastic input, carbonate productivity, sediment accumulation rates, and paleoenvironmental conditions dramatically affect the relative abundances of microfossils. Failure to recognize these complications can lead to a sequence stratigraphic interpretation that substantially overestimates the number of depositional sequences of 1 to 10 m.y. duration.

  18. Rapid formation of a modern bedrock canyon by a single flood event

    NASA Astrophysics Data System (ADS)

    Lamb, Michael P.; Fonstad, Mark A.

    2010-07-01

    Deep river canyons are thought to form slowly over geological time (see, for example, ref. 1), cut by moderate flows that reoccur every few years. In contrast, some of the most spectacular canyons on Earth and Mars were probably carved rapidly during ancient megaflood events. Quantification of the flood discharge, duration and erosion mechanics that operated during such events is hampered because we lack modern analogues. Canyon Lake Gorge, Texas, was carved in 2002 during a single catastrophic flood. The event offers a rare opportunity to analyse canyon formation and test palaeo-hydraulic-reconstruction techniques under known topographic and hydraulic conditions. Here we use digital topographic models and visible/near-infrared aerial images from before and after the flood, discharge measured during the event, field measurements and sediment-transport modelling to show that the flood moved metre-sized boulders, excavated ~7m of limestone and transformed a soil-mantled valley into a bedrock canyon in just ~3days. We find that canyon morphology is strongly dependent on rock type: plucking of limestone blocks produced waterfalls, inner channels and bedrock strath terraces, whereas abrasion of cemented alluvium sculpted walls, plunge pools and streamlined islands. Canyon formation was so rapid that erosion might have been limited by the ability of the flow to transport sediment. We suggest that our results might improve hydraulic reconstructions of similar megafloods on Earth and Mars.

  19. Effects of sea surface temperature anomaly on flooding events in Hunan province

    NASA Astrophysics Data System (ADS)

    Hu, Xinjia; Wang, Ming

    2016-04-01

    This study investigated the effect of sea surface temperature anomaly (SSTA) on flood-season precipitation in Hunan Province (the main grain-producing area in China) and change trend of the related flooding events. Based on the observation data of flood seasons in 44 stations of Hunan province from 1970-2013 and the sea surface temperature (SST) dataset from the Met Office Hadley Center, the empirical orthogonal function (EOF) analysis, power spectrum analysis and correlation analytical method have been conducted to identify the key time and marine regions which influence flood-season rainfall distribution. According to these analyses, two main spatial patterns of precipitation have been observed. The first and remarkable pattern is generally distributed uniformly throughout the region and is characterized by a 2-3-year and 20-23-year periods. The decadal variability has a negative correlation with the summer SSTA in the Indian Ocean near the equator, while the interannual variability is associated with the previous autumn and winter SSTA in the eastern Pacific. The second pattern illustrates dry-wet difference, indicating a north-to-south opposite, in a 3-year periods. The key area for influencing this mode is distributed in the Equator Pacific especially in the previous autumn and winter (known as ENSO). Furthermore, based on the EOF results of precipitation, we introduced the historical flooding event records of Hunan province and developed the spatial distribution maps and probability density curves for the direct economic losses in the years of anomaly and normal rainfall. The results reveal that the anomaly years suffer more serious losses and there is a corresponding relationship between north-to-south opposite precipitation mode and regional economic loss differences. With the function of illustrating the variation trend of hazards and the critical influence factor, these results are the data foundation for flood risk assessment. It can be used as a

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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.

  1. Transmission losses during two flood events in the Platte River, south-central Nebraska

    NASA Astrophysics Data System (ADS)

    Huang, Yuanyang; Chen, Xunhong; Chen, Xi; Ou, Gengxin

    2015-01-01

    The Platte River in south-central Nebraska is a priority reach to maintain appropriate in-stream flow for healthy stream habitat. Transmission losses normally take place here when flood wave or reservoir-release water travels through during summer and fall. However, it is found that the reservoir-release water hardly arrived at the habitat area due to the transmission losses. Meanwhile, the limited reservoir water also is critical for crop irrigations during the same season. Therefore, to reconcile the water requirement conflict, the knowledge of the temporal-spatial variations of the transmission losses along the river is necessary to better manage the released water. Two flood events, which were only generated by upstream rainstorms, traveled through the nearly non-flowing reach of the Platte River in south-central Nebraska during the summer of 2013. The hydrological records during the two flood events provided unique data sets to study the transmission losses in the reach. The objective of this study was to investigate the temporal-spatial variation of the transmission losses during the two flood events in the reach. A numerical-analytical transmission loss model was developed to support the analysis. The results indicated that the transmission loss process in the study reach would be reasonably simulated using an effective aquifer transmissivity value of 2000 m2/d and an effective stream leakance value of 600 1/d. About 52% and 21% of the stream water flowed into the reach became the transmission losses during the two flood events, respectively. The transmission losses significantly enhanced the stream stage attenuation during the two events. Due to the stream stage attenuation, the total transmission losses decreased linearly between the upstream and downstream gauges, but its detailed spatial variation can be documented based on further hydrogeological data collection along the reach.

  2. Event coincidence analysis for quantifying statistical interrelationships between event time series. On the role of flood events as triggers of epidemic outbreaks

    NASA Astrophysics Data System (ADS)

    Donges, J. F.; Schleussner, C.-F.; Siegmund, J. F.; Donner, R. V.

    2016-05-01

    Studying event time series is a powerful approach for analyzing the dynamics of complex dynamical systems in many fields of science. In this paper, we describe the method of event coincidence analysis to provide a framework for quantifying the strength, directionality and time lag of statistical interrelationships between event series. Event coincidence analysis allows to formulate and test null hypotheses on the origin of the observed interrelationships including tests based on Poisson processes or, more generally, stochastic point processes with a prescribed inter-event time distribution and other higher-order properties. Applying the framework to country-level observational data yields evidence that flood events have acted as triggers of epidemic outbreaks globally since the 1950s. Facing projected future changes in the statistics of climatic extreme events, statistical techniques such as event coincidence analysis will be relevant for investigating the impacts of anthropogenic climate change on human societies and ecosystems worldwide.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. News Teaching Support: New schools network launched Competition: Observatory throws open doors to a select few Festival: Granada to host 10th Ciencia en Acción Centenary: Science Museum celebrates 100 years Award: Queen's birthday honour for science communicator Teacher Training: Training goes where it's needed Conference: Physics gets creative in Christchurch Conference: Conference is packed with ideas Poster Campaign: Bus passengers learn about universe Forthcoming events

    NASA Astrophysics Data System (ADS)

    2009-09-01

    Teaching Support: New schools network launched Competition: Observatory throws open doors to a select few Festival: Granada to host 10th Ciencia en Acción Centenary: Science Museum celebrates 100 years Award: Queen's birthday honour for science communicator Teacher Training: Training goes where it's needed Conference: Physics gets creative in Christchurch Conference: Conference is packed with ideas Poster Campaign: Bus passengers learn about universe Forthcoming events

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

    PubMed

    Dages, C; 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 (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. PMID:26282746

  6. An efficient hybrid causative event-based approach for deriving the annual flood frequency distribution

    NASA Astrophysics Data System (ADS)

    Thyer, Mark; Li, Jing; Lambert, Martin; Kuczera, George; Metcalfe, Andrew

    2015-04-01

    Flood extremes are driven by highly variable and complex climatic and hydrological processes. Derived flood frequency methods are often used to predict the flood frequency distribution (FFD) because they can provide predictions in ungauged catchments and evaluate the impact of land-use or climate change. This study presents recent work on development of a new derived flood frequency method called the hybrid causative events (HCE) approach. The advantage of the HCE approach is that it combines the accuracy of the continuous simulation approach with the computational efficiency of the event-based approaches. Derived flood frequency methods, can be divided into two classes. Event-based approaches provide fast estimation, but can also lead to prediction bias due to limitations of inherent assumptions required for obtaining input information (rainfall and catchment wetness) for events that cause large floods. Continuous simulation produces more accurate predictions, however, at the cost of massive computational time. The HCE method uses a short continuous simulation to provide inputs for a rainfall-runoff model running in an event-based fashion. A proof-of-concept pilot study that the HCE produces estimates of the flood frequency distribution with similar accuracy as the continuous simulation, but with dramatically reduced computation time. Recent work incorporated seasonality into the HCE approach and evaluated with a more realistic set of eight sites from a wide range of climate zones, typical of Australia, using a virtual catchment approach. The seasonal hybrid-CE provided accurate predictions of the FFD for all sites. Comparison with the existing non-seasonal hybrid-CE showed that for some sites the non-seasonal hybrid-CE significantly over-predicted the FFD. Analysis of the underlying cause of whether a site had a high, low or no need to use seasonality found it was based on a combination of reasons, that were difficult to predict apriori. Hence it is recommended

  7. Long-term strategies of climate change adaptation to manage flooding events in urban areas

    NASA Astrophysics Data System (ADS)

    Pouget, Laurent; Russo, Beniamino; Redaño, Angel; Ribalaygua, Jaime

    2010-05-01

    Heavy and sudden rainfalls regularly affect the Mediterranean area, so a great number of people and buildings are exposed to the risk of rain-generated floods. Climate change is expected to modify this risk and, in the case that extreme rainfalls increase in frequencies and intensity, this could result in important damages, particularly in urban areas. This paper presents a project that aims to determine adaptation strategies to future flood risks in urban areas. It has been developed by a panel of water companies (R+i Alliance funding), and includes the evaluation of the climate change impact on the extreme rainfall, the use of innovative modelling tools to accurately forecast the flood risk and, finally, the definition of a pro-active and long-term planning against floods. This methodology has been applied in the city of Barcelona. Current climate models give some projections that are not directly applicable for flood risk studies, either because they do not have an adequate spatial and temporal resolution, or because they do not consider some important local factors, such as orography. These points have been considered within the project, when developing the design storms corresponding to future climatic conditions (e.g. years 2030 or 2050). The methodology uses statistical downscaling techniques based on global climate models predictions, including corrections for extreme events and convective storms, as well as temporal downscaling based on historical observations. The design storms created are used in combination with the predictions of sea level rise and land use evolutions to determine the future risk of flooding in the area of study. Once the boundary conditions are known, an accurate flood hazard assessment is done. It requires a local knowledge of the flow parameters in the whole analyzed domain. In urban catchments, in order to fulfill this requirement, powerful hydrological and hydraulic tools and detailed topographic data represent the unique way for

  8. On the dynamics of synoptic scale cyclones associated with flood events in Crete

    NASA Astrophysics Data System (ADS)

    Flocas, Helena; Katavoutas, George; Tsanis, Ioannis; Iordanidou, Vasiliki

    2015-04-01

    Flood events in the Mediterranean are frequently linked to synoptic scale cyclones, although topographical or anthropogenic factors can play important role. The knowledge of the vertical profile and dynamics of these cyclones can serve as a reliable early flood warning system that can further help in hazard mitigation and risk management planning. Crete is the second largest island in the eastern Mediterranean region, being characterized by high precipitation amounts during winter, frequently causing flood events. The objective of this study is to examine the dynamic and thermodynamic mechanisms at the upper and lower levels responsible for the generation of these events, according to their origin domain. The flooding events were recorded for a period of almost 20 years. The surface cyclones are identified with the aid of MS scheme that was appropriately modified and extensively employed in the Mediterranean region in previous studies. Then, the software VTS, specially developed for the Mediterranean cyclones, was employed to investigate the vertical extension, slope and dynamic/kinematic characteristics of the surface cyclones. Composite maps of dynamic/thermodynamic parameters, such as potential vorticity, temperature advection, divergence, surface fluxes were then constructed before and during the time of the flood. The dataset includes 6-hourly surface and isobaric analyses on a 0.5° x 0.5° regular latitude-longitude grid, as derived from the ERA-INTERIM Reanalysis of the ECMWF. It was found that cyclones associated with flood events in Crete mainly generate over northern Africa or southern eastern Mediterranean region and experience their minimum pressure over Crete or southwestern Greece. About 84% of the cyclones extend up to 500hPa, demonstrating that they are well vertically well-organized systems. The vast majority (almost 84%) of the surface cyclones attains their minimum pressure when their 500 hpa counterparts are located in the NW or SW, confirming

  9. Physical and economic impacts of sea-level rise and low probability flooding events on coastal communities.

    PubMed

    Prime, Thomas; Brown, Jennifer M; Plater, Andrew J

    2015-01-01

    Conventionally flood mapping typically includes only a static water level (e.g. peak of a storm tide) in coastal flood inundation events. Additional factors become increasingly important when increased water-level thresholds are met during the combination of a storm tide and increased mean sea level. This research incorporates factors such as wave overtopping and river flow in a range of flood inundation scenarios of future sea-level projections for a UK case study of Fleetwood, northwest England. With increasing mean sea level it is shown that wave overtopping and river forcing have an important bearing on the cost of coastal flood events. The method presented converts inundation maps into monetary cost. This research demonstrates that under scenarios of joint extreme surge-wave-river events the cost of flooding can be increased by up to a factor of 8 compared with an increase in extent of up to a factor of 3 relative to "surge alone" event. This is due to different areas being exposed to different flood hazards and areas with common hazard where flood waters combine non-linearly. This shows that relying simply on flood extent and volume can under-predict the actual economic impact felt by a coastal community. Additionally, the scenario inundation depths have been presented as "brick course" maps, which represent a new way of interpreting flood maps. This is primarily aimed at stakeholders to increase levels of engagement within the coastal community. PMID:25710497

  10. Physical and Economic Impacts of Sea-Level Rise and Low Probability Flooding Events on Coastal Communities

    PubMed Central

    Prime, Thomas; Brown, Jennifer M.; Plater, Andrew J.

    2015-01-01

    Conventionally flood mapping typically includes only a static water level (e.g. peak of a storm tide) in coastal flood inundation events. Additional factors become increasingly important when increased water-level thresholds are met during the combination of a storm tide and increased mean sea level. This research incorporates factors such as wave overtopping and river flow in a range of flood inundation scenarios of future sea-level projections for a UK case study of Fleetwood, northwest England. With increasing mean sea level it is shown that wave overtopping and river forcing have an important bearing on the cost of coastal flood events. The method presented converts inundation maps into monetary cost. This research demonstrates that under scenarios of joint extreme surge-wave-river events the cost of flooding can be increased by up to a factor of 8 compared with an increase in extent of up to a factor of 3 relative to “surge alone” event. This is due to different areas being exposed to different flood hazards and areas with common hazard where flood waters combine non-linearly. This shows that relying simply on flood extent and volume can under-predict the actual economic impact felt by a coastal community. Additionally, the scenario inundation depths have been presented as “brick course” maps, which represent a new way of interpreting flood maps. This is primarily aimed at stakeholders to increase levels of engagement within the coastal community. PMID:25710497

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

    NASA Astrophysics Data System (ADS)

    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

  12. Rapid Formation of a Modern Bedrock Canyon by a Single Flood Event (Invited)

    NASA Astrophysics Data System (ADS)

    Lamb, M. P.; Fonstad, M. A.

    2010-12-01

    Although ancient megafloods have carved some of the most spectacular canyons on Earth and Mars, quantifying flood discharge, duration and erosion mechanics is hampered because we lack modern analogs. Canyon Lake Gorge, Texas, was carved in 2002 during a single catastrophic flood event and offers a rare opportunity to analyze canyon formation and test paleo-hydraulic-reconstruction techniques under known topographic and hydraulic conditions. Here we use topography and imagery from before and after the flood, discharge measured during the event, field measurements, and sediment-transport modeling to show that the flood moved meter-sized boulders, excavated ~7 m of rock, and transformed a soil-mantled valley into a bedrock canyon in ~ 3 days. Canyon morphology is strongly dependent on rock type where plucking of limestone blocks produced waterfalls, inner channels and strath terraces, and abrasion of cemented alluvium sculpted walls, plunge pools and streamlined islands. Canyon formation was so rapid that erosion might have been limited by the ability of the flow to transport sediment, which greatly simplifies modeling and may improve hydraulic reconstructions of other megafloods on Earth and Mars.

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

    NASA Astrophysics Data System (ADS)

    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

  14. Analysis of a flood event on a karst river by means of a distributed hydrological model

    NASA Astrophysics Data System (ADS)

    Martina, Mario L. V.; de Waele, Jo; Sanna, Laura; Cabras, Salvatore; Antonello Cossu, Q.

    2010-05-01

    Fluviokarstic catchments are difficult to model especially during a flood event because of their hydrological complexity. The hydrological characterization is even more challenging for ungauged rivers. In the last five winters (2004-2008) several exceptional meteorological events producing flash floods have been registered in Central-East Sardinia on ungauged or poorly gauged catchments. We present here an approach to estimate the peak discharge taking into account the karst component. Peak discharge has been estimated based on a distributed hydrological model and on empirical methods that consider geomorphic and sedimentological observations. The comparison between the results derived from these independent methods allows to obtain the best possible estimate of peak discharge. Differences between modelled and measured peak flows can be attributed to water losses and/or gains along the river channel due to interactions with the underground karst drainage network. An application on a catchment in Central-East Sardinia is discussed.

  15. Potential of satellite rainfall products to predict Niger River flood events in Niamey

    NASA Astrophysics Data System (ADS)

    Casse, C.; Gosset, M.; Peugeot, C.; Pedinotti, V.; Boone, A.; Tanimoun, B. A.; Decharme, B.

    2015-09-01

    A dramatic increase in the frequency and intensity of flood events in the city of Niamey, Niger, has been observed in the last decade. The Niger River exhibits a double outflow peak in Niamey. The first peak, is due to the rainfall occurring within about 500 km of Niamey. It has reached high values in recent years and caused four drastic flood events since 2000. This paper analyses the potential of satellite rainfall products combined with hydrological modelling to monitor these floods. The study focuses on the 125,000 km2 area in the vicinity of Niamey, where local runoff supplies the first flood. Six rainfall products are tested : a gauge only product - the Climate Prediction Centre (CPC); two gauge adjusted satellite products - the Tropical Rainfall Measurement Mission (TRMM) Multi-Platform Analysis (TMPA 3B42v7) and the CPC regional product African Rainfall Estimate (RFE version 2); and three satellite only products, 3B42RT, the CPC Morphing method (CMORPH) and the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Network (PERSIANN). The products are first inter-compared over the region of interest. Differences in terms of rainfall amount, number of rainy days, spacial extension of the rainfall events and frequency distribution of the rain rates are highlighted. The satellite only products provide more rain than the gauge adjusted ones. The hydrological model ISBA-TRIP is forced with the six products and the simulated discharge is analysed and compared with the discharge observed in Niamey over the period 2000 to 2013. The simulations based on the satellite only rainfall produce an excess in the discharge. For flood prediction, the problem can be overcome by a prior adjustment of the products - as done here with probability matching - or by analysing the simulated discharge in terms of percentile or anomaly. All tested products exhibit some skills in detecting the relatively heavy rainfall that preceded the flood and in

  16. Ecological Responses to Extreme Flooding Events: A Case Study with a Reintroduced Bird

    PubMed Central

    Soriano-Redondo, Andrea; Bearhop, Stuart; Cleasby, Ian R.; Lock, Leigh; Votier, Stephen C.; Hilton, Geoff M.

    2016-01-01

    In recent years numerous studies have documented the effects of a changing climate on the world’s biodiversity. Although extreme weather events are predicted to increase in frequency and intensity and are challenging to organisms, there are few quantitative observations on the survival, behaviour and energy expenditure of animals during such events. We provide the first data on activity and energy expenditure of birds, Eurasian cranes Grus grus, during the winter of 2013–14, which saw the most severe floods in SW England in over 200 years. We fitted 23 cranes with telemetry devices and used remote sensing data to model flood dynamics during three consecutive winters (2012–2015). Our results show that during the acute phase of the 2013–14 floods, potential feeding areas decreased dramatically and cranes restricted their activity to a small partially unflooded area. They also increased energy expenditure (+15%) as they increased their foraging activity and reduced resting time. Survival did not decline in 2013–14, indicating that even though extreme climatic events strongly affected time-energy budgets, behavioural plasticity alleviated any potential impact on fitness. However under climate change scenarios such challenges may not be sustainable over longer periods and potentially could increase species vulnerability. PMID:27345214

  17. Ecological Responses to Extreme Flooding Events: A Case Study with a Reintroduced Bird.

    PubMed

    Soriano-Redondo, Andrea; Bearhop, Stuart; Cleasby, Ian R; Lock, Leigh; Votier, Stephen C; Hilton, Geoff M

    2016-01-01

    In recent years numerous studies have documented the effects of a changing climate on the world's biodiversity. Although extreme weather events are predicted to increase in frequency and intensity and are challenging to organisms, there are few quantitative observations on the survival, behaviour and energy expenditure of animals during such events. We provide the first data on activity and energy expenditure of birds, Eurasian cranes Grus grus, during the winter of 2013-14, which saw the most severe floods in SW England in over 200 years. We fitted 23 cranes with telemetry devices and used remote sensing data to model flood dynamics during three consecutive winters (2012-2015). Our results show that during the acute phase of the 2013-14 floods, potential feeding areas decreased dramatically and cranes restricted their activity to a small partially unflooded area. They also increased energy expenditure (+15%) as they increased their foraging activity and reduced resting time. Survival did not decline in 2013-14, indicating that even though extreme climatic events strongly affected time-energy budgets, behavioural plasticity alleviated any potential impact on fitness. However under climate change scenarios such challenges may not be sustainable over longer periods and potentially could increase species vulnerability. PMID:27345214

  18. Flow monitoring with a camera: a case study on a flood event in the Tiber River.

    PubMed

    Tauro, F; Olivieri, G; Petroselli, A; Porfiri, M; Grimaldi, S

    2016-02-01

    Monitoring surface water velocity during flood events is a challenging task. Techniques based on deploying instruments in the flow are often unfeasible due to high velocity and abundant sediment transport. A low-cost and versatile technology that provides continuous and automatic observations is still not available. Among remote methods, large-scale particle image velocimetry (LSPIV) is an optical method that computes surface water velocity maps from videos recorded with a camera. Here, we implement and critically analyze findings obtained from a recently introduced LSPIV experimental configuration during a flood event in the Tiber River at a cross section located in the center of Rome, Italy. We discuss the potential of LSPIV observations in challenging environmental conditions by presenting results from three tests performed during the hydrograph flood peak and recession limb of the event for different illumination and weather conditions. The obtained surface velocity maps are compared to the rating curve velocity and to benchmark velocity values. Experimental findings show that optical methods should be preferred in extreme conditions. However, their practical implementation may be associated with further hurdles and uncertainties. PMID:26812952

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

    PubMed

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

    2014-07-01

    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. PMID:24727214

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

    NASA Astrophysics Data System (ADS)

    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

  1. Reconstruction of Flooding Events for the Central Valley, California from Instrumental and Documentary Weather Records

    NASA Astrophysics Data System (ADS)

    Dodds, S. F.; Mock, C. J.

    2009-12-01

    All available instrumental winter precipitation data for the Central Valley of California back to 1850 were digitized and analyzed to construct continuous time series. Many of these data, in paper or microfilm format, extend prior to modern National Weather Service Cooperative Data Program and Historical Climate Network data, and were recorded by volunteer observers from networks such as the US Army Surgeon General, Smithsonian Institution, and US Army Signal Service. Given incomplete individual records temporally, detailed documentary data from newspapers, personal diaries and journals, ship logbooks, and weather enthusiasts’ instrumental data, were used in conjunction with instrumental data to reconstruct precipitation frequency per month and season, continuous days of precipitation, and to identify anomalous precipitation events. Multilinear regression techniques, using surrounding stations and the relationships between modern and historical records, bridge timeframes lacking data and provided homogeneous nature of time series. The metadata for each station was carefully screened, and notes were made about any possible changes to the instrumentation, location of instruments, or an untrained observer to verify that anomalous events were not recorded incorrectly. Precipitation in the Central Valley varies throughout the entire region, but waterways link the differing elevations and latitudes. This study integrates the individual station data with additional accounts of flood descriptions through unique newspaper and journal data. River heights and flood extent inundating cities, agricultural lands, and individual homes are often recorded within unique documentary sources, which add to the understanding of flood occurrence within this area. Comparisons were also made between dam and levee construction through time and how waters are diverted through cities in natural and anthropogenically changed environments. Some precipitation that lead to flooding events that

  2. A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley

    USGS Publications Warehouse

    Thieler, E.R.; Butman, B.; Schwab, W.C.; Allison, M.A.; Driscoll, N.W.; Donnelly, J.P.; Uchupi, E.

    2007-01-01

    The Hudson Shelf Valley (HSV) is the largest physiographic feature on the U.S. mid-Atlantic continental shelf. The 150-km long valley is the submerged extension of the ancestral Hudson River Valley that connects to the Hudson Canyon. Unlike other incised valleys on the mid-Atlantic shelf, it has not been infilled with sediment during the Holocene. Analyses of multibeam bathymetry, acoustic backscatter intensity, and high-resolution seismic reflection profiles reveal morphologic and stratigraphic evidence for a catastrophic meltwater flood event that formed the modern HSV. The valley and its distal deposits record a discrete flood event that carved 15-m high banks, formed a 120-km2 field of 3- to 6-m high bedforms, and deposited a subaqueous delta on the outer shelf. The HSV is inferred to have been carved initially by precipitation and meltwater runoff during the advance of the Laurentide Ice Sheet, and later by the drainage of early proglacial lakes through stable spillways. A flood resulting from the failure of the terminal moraine dam at the Narrows between Staten Island and Long Island, New York, allowed glacial lakes in the Hudson and Ontario basins to drain across the continental shelf. Water level changes in the Hudson River basin associated with the catastrophic drainage of glacial lakes Iroquois, Vermont, and Albany around 11,450 14C year BP (∼ 13,350 cal BP) may have precipitated dam failure at the Narrows. This 3200 km3 discharge of freshwater entered the North Atlantic proximal to the Gulf Stream and may have affected thermohaline circulation at the onset of the Intra-Allerød Cold Period. Based on bedform characteristics and fluvial morphology in the HSV, the maximum freshwater flux during the flood event is estimated to be ∼ 0.46 Sv for a duration of ∼ 80 days.

  3. Estimated 100-year peak flows and flow volumes in the Big Lost River and Birch Creek at the Idaho National Engineering Laboratory, Idaho

    SciTech Connect

    Kjelstrom, L.C.; Berenbrock, C.

    1996-12-31

    The purpose of this report is to provide estimates of the 100-year peak flows and flow volumes that could enter the INEL area from the Big Lost River and Brich Creek are needed as input data for models that will be used to delineate the extent of the 100-year flood plain at the INEL. The methods, procedures and assumptions used to estimate the 100-year peak flows and flow volumes are described in this report.

  4. Agent based models for testing city evacuation strategies under a flood event as strategy to reduce flood risk

    NASA Astrophysics Data System (ADS)

    Medina, Neiler; Sanchez, Arlex; Nokolic, Igor; Vojinovic, Zoran

    2016-04-01

    This research explores the uses of Agent Based Models (ABM) and its potential to test large scale evacuation strategies in coastal cities at risk from flood events due to extreme hydro-meteorological events with the final purpose of disaster risk reduction by decreasing human's exposure to the hazard. The first part of the paper corresponds to the theory used to build the models such as: Complex adaptive systems (CAS) and the principles and uses of ABM in this field. The first section outlines the pros and cons of using AMB to test city evacuation strategies at medium and large scale. The second part of the paper focuses on the central theory used to build the ABM, specifically the psychological and behavioral model as well as the framework used in this research, specifically the PECS reference model is cover in this section. The last part of this section covers the main attributes or characteristics of human beings used to described the agents. The third part of the paper shows the methodology used to build and implement the ABM model using Repast-Symphony as an open source agent-based modelling and simulation platform. The preliminary results for the first implementation in a region of the island of Sint-Maarten a Dutch Caribbean island are presented and discussed in the fourth section of paper. The results obtained so far, are promising for a further development of the model and its implementation and testing in a full scale city

  5. Weather and Climatic Drivers of Extreme Flooding Events over the Midwest of the United States

    NASA Astrophysics Data System (ADS)

    Robertson, A. W.; Lall, U.; Kushnir, Y.; Nakamura, J.

    2012-12-01

    There is an urgent need to better understand how partly predictable modes of climate variability impact the probability of flood events in space and time, across multiple time scales, from weekly to seasonal, interannual and beyond. Climate undergoes natural fluctuations through persistent and oscillatory regimes at intraseasonal (e.g., the 30--60 day Madden Julian Oscillation, MJO), interannual (e.g., the El Niño-Southern Oscillation, ENSO) timescales, as well as decadal and longer (e.g., the Pacific Decadal Oscillation, PDO), and as a function of anthropogenic changes of the atmosphere and land surface. This multi-timescale climatic evolution modulates the ``odds'' for local precipitation and soil moisture events, and hence for floods. An outstanding scientific challenge is to develop predictive probabilistic climate information of flood likelihood across these time scales, and to determine in which regions/basins or time-windows of opportunity such information may be of potential practical value. Using the Midwest of the United States as a case study, we present an analysis of daily circulation regimes derived from reanalysis wind data using a K-means cluster analysis for the March--May season, from which we infer relationships between flooding events and circulation regimes, as well as relationships between these regimes and climate variations throughout the 20th century on interdecadal, interannual, as well as intraseasonal timescales. The results of this work illustrate how typical and recurrent synoptic daily circulation patterns that drive enhanced southerly fluxes of moisture from the Gulf of Mexico are preferentially associated with extreme floods over the U.S. Midwest during the spring season, and how these same geopotential height patterns tend to occur more frequently during the La Niña phase of ENSO and certain phases of the MJO. The seasonality of flood occurrence as a function of latitude and longitude within the Midwest is tied to the seasonality

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

    SciTech Connect

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

    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 containment vessel

  7. Characterization of flood and precipitation events in Southwestern Germany and stochastic simulation of extreme precipitation (Project FLORIS-SV)

    NASA Astrophysics Data System (ADS)

    Florian, Ehmele; Michael, Kunz

    2016-04-01

    Several major flood events occurred in Germany in the past 15-20 years especially in the eastern parts along the rivers Elbe and Danube. Examples include the major floods of 2002 and 2013 with an estimated loss of about 2 billion Euros each. The last major flood events in the State of Baden-Württemberg in southwest Germany occurred in the years 1978 and 1993/1994 along the rivers Rhine and Neckar with an estimated total loss of about 150 million Euros (converted) each. Flood hazard originates from a combination of different meteorological, hydrological and hydraulic processes. Currently there is no defined methodology available for evaluating and quantifying the flood hazard and related risk for larger areas or whole river catchments instead of single gauges. In order to estimate the probable maximum loss for higher return periods (e.g. 200 years, PML200), a stochastic model approach is designed since observational data are limited in time and space. In our approach, precipitation is linearly composed of three elements: background precipitation, orographically-induces precipitation, and a convectively-driven part. We use linear theory of orographic precipitation formation for the stochastic precipitation model (SPM), which is based on fundamental statistics of relevant atmospheric variables. For an adequate number of historic flood events, the corresponding atmospheric conditions and parameters are determined in order to calculate a probability density function (pdf) for each variable. This method involves all theoretically possible scenarios which may not have happened, yet. This work is part of the FLORIS-SV (FLOod RISk Sparkassen Versicherung) project and establishes the first step of a complete modelling chain of the flood risk. On the basis of the generated stochastic precipitation event set, hydrological and hydraulic simulations will be performed to estimate discharge and water level. The resulting stochastic flood event set will be used to quantify the

  8. Looking for the factors involved in the evolution of flood events in the Northeast of the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Llasat, Maria Carmen; Marcos, Raül; Turco, Marco; Gilabert, Joan; Llasat-Botija, Montserrat; Cortès, Maria; del Moral, Anna; Rigo, Tomeu

    2016-04-01

    This contribution comprises the analysis of the evolution of flood events in the Northwestern Mediterranean area, their trends and the possible associated factors related with vulnerability and hazard changes, in basis to the information collected in the INUNGAMA and FLOODHYMEX databases, and in the present Spanish project HOPE. The contribution is also focused on the characterisation of the degree of the convective contribution to rainfall, introducing the β parameter as the ratio between convective precipitation versus total precipitation in any period, in the Northeastern part of the Iberian Peninsula, for which some precipitation series at subdaily resolution exist. The trend analysis shows a little increase in flood events although no trend has been detected in extreme values of precipitation at daily scale, neither in the associated ETCCDI index. This result could point to a vulnerability and exposure increase or changes in the land uses. This flood event increase is particularly important in summer, when this events are mainly flash-floods produced by short and local convective phenomena. A summer increase of the convective contribution concentrated in less torrential events has been found in some parts of the region that could explain, partially, this positive trend on flash flood events. Our contribution also explores the evolution of the floods impact and the role of the measures of resilience.

  9. Influence of climate variability and urban areas on the flood events in Bari (Apulia, southern Italy)

    NASA Astrophysics Data System (ADS)

    Lonigro, Teresa; Polemio, Maurizio

    2014-05-01

    The Damaging Hydrogeological Events (DHEs) can be defined as the occurrence of one or more simultaneous phenomena, such as droughts, windstorms, heat waves, landslides, floods and secondary floods (i.e. rapid accumulation or pounding of surface water with very low flow velocity), causing damages. They represent a serious problem, especially in DHE-prone areas with growing urbanization, where the infiltration capability is limited by buildings and where the vulnerability is higher than other areas. The paper proposes a methodology, based on both historical and time series approaches, used for describing the influence of climatic variability and urban development on the number of phenomena observed. The historical approach is finalised to collect phenomenon historical data, very important for the comprehension of the evolution of a study area. Phenomenon historical data is useful for expanding the historical period of investigation in order to assess the occurrence trend of DHEs. The historical analysis of DHEs can support decision making and land-use planning, ultimately reducing natural risks. The time series approach includes the collection and the statistical analysis of climatic data (monthly rainfall, wet days, rainfall intensity, and temperature), useful to characterise the climate variations and trends and to roughly assess the effects of these trends on river discharge and on the triggering of landslides. The time series approach is completed by tools to analyse simultaneously all data types. The study of land use variations, with a special emphasis on the urban areas, is important to understand how the modifications occurred in the territory, especially in terms of vulnerability, could influence the occurrence of DHEs. The methodology can be applied simultaneously to floods and landslides and was tested considering the municipality of Bari (southern Italy), particularly affected by flood events. Since the climate trend (decreasing trend of rainfall and

  10. Hydroclimatology of Extreme Drought and Flood Events in the Northern High Plains, U.S.

    NASA Astrophysics Data System (ADS)

    Smith, K.; Morton, M.; Rico, D.; Mohamad Abadi, A.; Luna, I.; Livneh, B.; Munoz-Arriola, F.

    2014-12-01

    The goal is to illustrate the hydroclimatology of extreme droughts and floods, in the Northern High Plains (NHP). The state of Nebraska has the largest number of irrigated acres in the US by state; thus is exceedingly dependent on the availability of groundwater. Regions along the great Ogallala aquifer have already experienced a dramatic reduction of groundwater with most areas seeing water table drops of 10-50 feet in depth, with several recorded drops of over 100 feet. Finite groundwater resources availability challenges agroecosystems and ecosystem sustainability, leaving productive areas subject to the availability of surface water. However, our understanding on the predictability of extreme events is still limited. Thus our question is: What is the sensitivity of the NHP to extreme droughts and floods? Duration, frequency, and the area of influence of floods and droughts vary but can occur at the same time in different regions or at different times in the same region. Our objective is to (a) identify spatiotemporal patterns of variability of floods and droughts in NHP's land surface hydrology (LSH); and (b) account for the spatiotemporal impacts of deficits and surpluses of water at the basin-scale. The hypothesis is that areas of influence and the associated duration of droughts and floods will be more sensitive to different LSH variables and state variables than to the statistical approaches used to analyze them. To test the present hypothesis we will use gridded observed (precipitation) and simulated LSH variables (runoff, baseflow, and soil moisture) on the Platte River Basin. Precipitation, minimum and maximum temperatures, and wind speed force the Variable infiltration Capacity model at 1/16th degree resolution from 1950 to 2013. Drought indices based on percentiles estimated from Gamma, General Extreme Value, and Gumble distribution functions are estimated using daily observed and simulated variables for the domains and timespans mentioned above

  11. Characterization of the Temporal Clustering of Flood Events across the Central United States in terms of Climate States

    NASA Astrophysics Data System (ADS)

    Mallakpour, Iman; Villarini, Gabriele; Jones, Michael; Smith, James

    2016-04-01

    The central United States is a region of the country that has been plagued by frequent catastrophic flooding (e.g., flood events of 1993, 2008, 2013, and 2014), with large economic and social repercussions (e.g., fatalities, agricultural losses, flood losses, water quality issues). The goal of this study is to examine whether it is possible to describe the occurrence of flood events at the sub-seasonal scale in terms of variations in the climate system. Daily streamflow time series from 774 USGS stream gage stations over the central United States (defined here to include North Dakota, South Dakota, Nebraska, Kansas, Missouri, Iowa, Minnesota, Wisconsin, Illinois, West Virginia, Kentucky, Ohio, Indiana, and Michigan) with a record of at least 50 years and ending no earlier than 2011 are used for this study. We use a peak-over-threshold (POT) approach to identify flood peaks so that we have, on average two events per year. We model the occurrence/non-occurrence of a flood event over time using regression models based on Cox processes. Cox processes are widely used in biostatistics and can be viewed as a generalization of Poisson processes. Rather than assuming that flood events occur independently of the occurrence of previous events (as in Poisson processes), Cox processes allow us to account for the potential presence of temporal clustering, which manifests itself in an alternation of quiet and active periods. Here we model the occurrence/non-occurrence of flood events using two climate indices as climate time-varying covariates: the North Atlantic Oscillation (NAO) and the Pacific-North American pattern (PNA). The results of this study show that NAO and/or PNA can explain the temporal clustering in flood occurrences in over 90% of the stream gage stations we considered. Analyses of the sensitivity of the results to different average numbers of flood events per year (from one to five) are also performed and lead to the same conclusions. The findings of this work

  12. The Severe Flooding Event of January 1996 across North-Central Pennsylvania.

    NASA Astrophysics Data System (ADS)

    Leathers, Daniel J.; Kluck, Douglas R.; Kroczynski, Scott

    1998-05-01

    The rapid ablation of a snowpack and intense rainfall combined to cause catastrophic flooding across much of the mid-Atlantic region of the United States on 18 and 19 January 1996. This flooding event resulted in as many as 30 fatalities, numerous injuries, and damage estimated at $1.5 billion. The Loyalsock and Lycoming Creek watersheds in northern Pennsylvania were arguably the hardest hit areas in the region, at least from the perspective of fatalities and injuries. This flooding event, which was certainly devastating from a human and economic perspective, also represents an interesting scientific situation in which climatological preconditioning and the occurrence of an unusual synoptic-scale weather event combined to create disastrous results.Before the event, snow fell at record levels across northern Pennsylvania during the late autumn and early winter seasons. By the middle of January 1996, more snow had fallen across the combined watershed region than is expected during an average snowfall season. The heavy snowfall, in conjunction with anomalously low temperatures, combined to create an exceptionally deep snowpack containing 7.5-15 cm of snow water equivalent. A strong synoptic-scale disturbance that moved across the United States from 17 through 20 January 1996 initiated meteorological conditions that rapidly ablated the snowpack and dropped more than 7.5 cm of liquid precipitation in a 24-h period in the combined watershed region.A one-dimensional mass and energy balance snowpack model (SNTHERM) was used to evaluate the magnitude of the surface energy fluxes that were associated with the movement of the synoptic-scale system through the area. Further, the model was used in a sensitivity analysis mode to determine the meteorological variables most important to the ablation of the snowpack. Results indicate that high dewpoint temperatures and high wind speeds were at least as important as high temperatures and precipitation to the severity of the flooding

  13. Analysis of a Monsoon Flood Event Effect on Surface and Groundwater Interactions in a Regional Semiarid Watershed

    NASA Astrophysics Data System (ADS)

    Bowman, R. S.; Vivoni, E. R.; Wyckoff, R.; Jakubowski, R.; Richards, K.

    2004-12-01

    Although sporadic and infrequent, flooding events in ephemeral watersheds are a critical component to the water, sediment and biogeochemical cycles in arid and semiarid regions. In the Southwestern United States, intense thunderstorms during the summer monsoon season interact with landscapes characterized by topographic complexity and soils of low infiltration capacity to produce large magnitude floods and flash floods. In this study, we examine the hydrometeorological conditions and hydrologic response of an extreme monsoon flood event in the Río Puerco watershed of north-central New Mexico and its downstream effects in the Río Grande, a major continental-scale river basin. The summer storm in early September 4-11, 2003 generated flash flooding in headwater basins and river flooding extending through the semiarid basin and downstream into the Río Grande for several tens of kilometers. We characterize the hydrometeorological conditions prior to the flood event using precipitation estimates from rain gauge records, NEXRAD radar data, and synoptic weather conditions over the 18,000 km2 Río Puerco basin. Then, we present the spatial and temporal variability in hydrologic response based on a set of nested stream gauges in river channels and irrigation canals as well as a network of instrumented well transects installed along the Río Grande alluvial aquifer. Our analysis illustrates the propagation, dampening, and attenuation of a large monsoonal storm through a semiarid ephemeral tributary into a regional river system from both a surface and groundwater hydrology perspective, including the water exchanges observed between the two systems. By estimating the frequency of the rainfall and flood event in the system relative to the historical record and known shifts in climate regime, we discuss the importance of extreme flood events in semiarid tributary systems and their downstream effects in the surface and groundwater interactions of regional river basins.

  14. Downscaling 20th century flooding events in complex terrain (Switzerland) using the WRF regional climate model

    NASA Astrophysics Data System (ADS)

    Heikkilä, Ulla; Gómez Navarro, Juan Jose; Franke, Jörg; Brönnimann, Stefan; Cattin, Réne

    2016-04-01

    Switzerland has experienced a number of severe precipitation events during the last few decades, such as during the 14-16 November of 2002 or during the 21-22 August of 2005. Both events, and subsequent extreme floods, caused fatalities and severe financial losses, and have been well studied both in terms of atmospheric conditions leading to extreme precipitation, and their consequences [e.g. Hohenegger et al., 2008, Stucki et al., 2012]. These examples highlight the need to better characterise the frequency and severity of flooding in the Alpine area. In a larger framework we will ultimately produce a high-resolution data set covering the entire 20th century to be used for detailed hydrological studies including all atmospheric parameters relevant for flooding events. In a first step, we downscale the aforementioned two events of 2002 and 2005 to assess the model performance regarding precipitation extremes. The complexity of the topography in the Alpine area demands high resolution datasets. To achieve a sufficient detail in resolution we employ the Weather Research and Forecasting regional climate model (WRF). A set of 4 nested domains is used with a 2-km resolution horizontal resolution over Switzerland. The NCAR 20th century reanalysis (20CR) with a horizontal resolution of 2.5° serves as boundary condition [Compo et al., 2011]. First results of the downscaling the 2002 and 2005 extreme precipitation events show that, compared to station observations provided by the Swiss Meteorological Office MeteoSwiss, the model strongly underestimates the strength of these events. This is mainly due to the coarse resolution of the 20CR data, which underestimates the moisture fluxes during these events. We tested driving WRF with the higher-resolved NCEP reanalysis and found a significant improvement in the amount of precipitation of the 2005 event. In a next step we will downscale the precipitation and wind fields during a 6-year period 2002-2007 to investigate and

  15. Spring wheat gliadins: Have they changed in 100 years?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There have been many hard red spring (HRS) wheat cultivars released in North Dakota during the last 100 years. These cultivars have been improved for various characteristics such as, adaptation to weather conditions, high yield, and good milling and baking quality. The objectives of this study wer...

  16. 100 Years of Commitment to Children: Change and Continuity.

    ERIC Educational Resources Information Center

    Shore, Rima

    The Foundation for Child Development (FCD) is the oldest philanthropy in the nation focused on improving the life prospects of children. This booklet, produced for FCD's centennial, describes the organization's origins and changes during the past 100 years. The booklet's sections, which include photographs, quotes, and a timeline, are: (1) "The…

  17. Centennial Calendar- 100 Years of the American Phytopathological Society

    Technology Transfer Automated Retrieval System (TEKTRAN)

    I edited a 40-page publication (calendar) that covered 18 chapters written by members of our society. This covered pioneering researchers, departments, and epidemics of the last 100 years of plant pathology in the U. S. This was given to all members of the American Phytopathological Society who att...

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

    SciTech Connect

    Yan, Guanhua; Nicol, David M; Jin, Dong

    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.

  19. ENSO-driven flooding events in East Java, Indonesia during the past Millennium

    NASA Astrophysics Data System (ADS)

    Rodysill, J. R.; Russell, J. M.; Vuille, M. F.; Lunghino, B.; Bijaksana, S.

    2013-12-01

    Recent severe El Niño-Southern Oscillation (ENSO) events have highlighted the importance of understanding the mechanisms driving ENSO variability and how ENSO relates to extreme precipitation anomalies. Expanding the record of ENSO-driven precipitation anomalies over the last millennium through paleoclimate reconstructions illuminates how ENSO has varied in the past through periods of relatively enhanced and reduced radiative forcing, namely the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA). Modern precipitation anomalies in East Java, Indonesia are strongly correlated to variations in ENSO, where La Niña events correspond to positive precipitation anomalies (Hendon, 2003, Journal of Climate). We present the first record of runoff events from lake sediment deposits in East Java, Indonesia spanning the last millennium, which historically occur during strong La Niña events. Our record reveals significant variations in East Java flooding frequency, with more frequent floods occurring from 850 to 1350 CE and after 1800 CE. This pattern is also observed in surface runoff records from the eastern tropical Pacific (Moy et al., 2002, Nature; Conroy et al., 2008, Quaternary Science Reviews), which lie in a region where modern positive precipitation anomalies are closely tied to El Niño events. Extreme rainfall events occurring on both sides of the tropical Pacific on centennial timescales may indicate that both El Niño and La Niña activity were higher during the Medieval Climate Anomaly and the most recent two centuries, when radiative forcing was high, and that ENSO activity was reduced during the Little Ice Age, when radiative forcing was weak.

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

    NASA Astrophysics Data System (ADS)

    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.

  1. The human impact of floods: a historical review of events 1980-2009 and systematic literature review.

    PubMed

    Doocy, Shannon; Daniels, Amy; Murray, Sarah; Kirsch, Thomas D

    2013-01-01

    Background. Floods are the most common natural disaster and the leading cause of natural disaster fatalities worldwide. Risk of catastrophic losses due to flooding is significant given deforestation and the increasing proximity of large populations to coastal areas, river basins and lakeshores. The objectives of this review were to describe the impact of flood events on human populations in terms of mortality, injury, and displacement and, to the extent possible, identify risk factors associated with these outcomes. This is one of five reviews on the human impact of natural disasters Methods. Data on the impact of floods were compiled using two methods, a historical review of flood events from 1980 to 2009 from multiple databases and a systematic literature review of publications ending in October 2012. Analysis included descriptive statistics, bivariate tests for associations and multinomial logistic regression of flood characteristics and mortality using Stata 11.0. Findings. There were 539,811 deaths (range: 510,941 to 568,680), 361,974 injuries and 2,821,895,005 people affected by floods between 1980 and 2009. Inconsistent reporting suggests this is an underestimate, particularly in terms of the injured and affected populations. The primary cause of flood-related mortality is drowning; in developed countries being in a motor-vehicle and male gender are associated with increased mortality, whereas female gender may be linked to higher mortality in low-income countries. Conclusions. Expanded monitoring of floods, improved mitigation measures, and effective communication with civil authorities and vulnerable populations has the potential to reduce loss of life in future flood events. PMID:23857425

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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

  4. Improvement of hydrological flood forecasting through an event based output correction method

    NASA Astrophysics Data System (ADS)

    Klotz, Daniel; Nachtnebel, Hans Peter

    2014-05-01

    This contribution presents an output correction method for hydrological models. A conceptualisation of the method is presented and tested in an alpine basin in Salzburg, Austria. The aim is to develop a method which is not prone to the drawbacks of autoregressive models. Output correction methods are an attractive option for improving hydrological predictions. They are complementary to the main modelling process and do not interfere with the modelling process itself. In general, output correction models estimate the future error of a prediction and use the estimation to improve the given prediction. Different estimation techniques are available dependent on the utilized information and the estimation procedure itself. Autoregressive error models are widely used for such corrections. Autoregressive models with exogenous inputs (ARX) allow the use of additional information for the error modelling, e.g. measurements from upper basins or predicted input-signals. Autoregressive models do however exhibit deficiencies, since the errors of hydrological models do generally not behave in an autoregressive manner. The decay of the error is usually different from an autoregressive function and furthermore the residuals exhibit different patterns under different circumstances. As for an example, one might consider different error-propagation behaviours under high- and low-flow situations or snow melt driven conditions. This contribution presents a conceptualisation of an event-based correction model and focuses on flood events only. The correction model uses information about the history of the residuals and exogenous variables to give an error-estimation. The structure and parameters of the correction models can be adapted to given event classes. An event-class is a set of flood events that exhibit a similar pattern for the residuals or the hydrological conditions. In total, four different event-classes have been identified in this study. Each of them represents a different

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    The analysis of drought events of 1997/98, 2005 and 2010 in terms of discharge anomalies in the Amazon region confirmed previous findings, such as: a) the influence of the El Niño in more than one hydrological year; b) the increase of the influence of the Atlantic Multidecadal Oscillation of 1998, 2005 and 2010 drought events; c) the low levels of discharge observed in the 2010 drought are attributed to the association of discharge anomalies of the northern and southern tributaries of the Amazon river, and d) the 2010 drought lasted around 1 month (August to November) more than the other drought events analized here. The riverine communities located along the river banks of Solimões/Amazonas suit their economic activities to the oscillation of the water level. In general, low water periods favor the access to important sources of food such as fish and livestock, still allowing crop cultivation on fertile agricultural areas of the floodplain. Conversely, periods of drought increases the difficulties of transport and drinking water supply. During the high water, access to the main food supply (described above) are greatly hampered. However, the floods are recognized as an importance process of natural fertilization. Thus, despite the political, social and economic shortcomings, the local community has, since the pre-colonial period, learned to get the best of each season, providing local, regional and national markets with varzea products. During periods of extreme weather, however, the advantages of each season appear to be reduced, and the drawbacks increased. In fact, during flooding extremes, the access to primary sources of food is hampered by a long period of time and families find themselves forced to leave their homes, eventually losing them. Analysis of flow data to the extreme flooding of 2009, indicate a period of about 6 months of positive anomalies discharge (occurring mainly during high water). At the same time, Civil Defense data points to a

  6. A universal celebration: 100 years of Korotkoff sounds, 1905 - 2005.

    PubMed

    Naqvi, Nasim H

    2005-12-01

    The measurement of systolic and diastolic blood pressure by auscultation was first described 100 years ago, when a young Russian army doctor, Nicolai Sergeevich Korotkoff, addressed a meeting at the Medical Academy of St. Petersburg on 8th November 1905. During the last hundred years, Korotkoff's contribution has proved to be one of the most useful methods in the diagnosis, treatment, monitoring and prevention of life threatening cardiovascular ailments and the centenary of his discovery should be celebrated universally. PMID:17153281

  7. Using an extended 2D hydrodynamic model for evaluating damage risk caused by extreme rain events: Flash-Flood-Risk-Map (FFRM) Upper Austria

    NASA Astrophysics Data System (ADS)

    Humer, Günter; Reithofer, Andreas

    2016-04-01

    at 20th of June 2012, based on open data sources of geology, soil and land use. The aim of FFRM is to provide an estimation of the damage risk caused by flash-floods for the whole of Upper Austria. To address the hazard, inundation depths were calculated with the extended 2D-model using design rains with an 100-year return period provided by the Environmental Ministry [7]. The potential damage was calculated using damage functions, which were derived from our experience from damage surveys of past events in Austria and according to guidelines for determination of cost-benefit-ratios for flood protection measures [8]. The greatest difficulty was to get appropriate data for the distribution of houses and industrial plants. Zoning plans provide good information on spatial distribution of residential, commercial and industrial areas, but does not contain information on the kind of industry, which is essential for estimating absolute damage values. To get a first idea detailed information from surveyed areas was intersected with the zoning plan, which provides an average damage in the respective zones. The first results can be found on www.waterviewer.com and will be updated with the further development of the project. [1] URBAS, risk management of extreme flooding events - prediction and management of flash floods in urban areas, www.urbanesturzfluten.de, prompted on 13th of November 2014 [2] Società Meteorologica Italiana (SMI), http://www.nimbus.it/eventi/2013/130624flashfloodRimini.pdf, prompted on 13th of November 2014 [3]Newspaper "Österreich", http://www.oe24.at/oesterreich/chronik/Sturzflut-Regen-legt-Ost-Oesterreich-lahm/1509113, prompted on 13th of November 2014 [4] Newspaper „Oberösterreichische Nachrichten", http://www.nachrichten.at/oberoesterreich/Unwetter-Mure-riss-Strasse-mit-Wohnhaus-in-Gosau-gefaehrdet;art4,911288 , prompted on 13th of November 2014 [5] Sharing Water-related Information to Tackle Changes in the Hydrosphere - for Operational Needs

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

    NASA Astrophysics Data System (ADS)

    Trigo, Ricardo; Varino, Filipa; Ramos, Alexandre; Valente, Maria; Zêzere, José; Vaquero, José; Gouveia, Célia; Russo, Ana

    2014-04-01

    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 central Atlantic Ocean.

  9. Response and recovery of streams to an intense regional flooding event

    NASA Astrophysics Data System (ADS)

    Dethier, E.; Magilligan, F. J.; Renshaw, C. E.; Kantack, K. M.

    2015-12-01

    Determining the relative roles of frequent and infrequent events on landscape form and material transport has implications for understanding landscape development, and informs planning and infrastructure decisions. Flooding due to Tropical Storm Irene in 2011 provides a unique opportunity to examine the effects of a rare, major disturbance across a broad area (14,000 km2). Intense flooding caused variable but widespread channel and riparian reconfiguration, including 995 channel-adjacent mass-wasting events, collectively referred to here as landslides, that mostly occurred in glacial deposits. Of these, about half involved reactivation of existing scars. Landslides were generally small, ranging from 60 - 26,000 m2 in planform, and covered less than 0.01 % of land in the region, yet sediment input from landslides alone (131 mm/kyr when integrated over the study area) exceeded inferred local background erosion rates by 60 times. If Irene inputs are included in a thirty-year erosion record, the estimated erosion rate, 7.2 mm/kyr, aligns closely with long-term regional rates of 5-10 mm/kyr. Landslides also input trees to streams, increasing large wood influence on those reaches. Combined wood and sediment inputs contributed to channel changes downstream of landslides. In four years since Irene, terrestrial lidar and suspended sediment sampling has documented continued large wood and sediment input. Erosion occurred on each of seventeen monitored landslides during snowmelt, but is otherwise limited except during intense precipitation and/or flood events. Repeat lidar models have recorded erosion of up to 5,000 m3 on a single slide in one year, including as much as 4000 m3 during a single event. Tree fall on scarps during erosion events creates sediment traps at the base of landslides, contributing to an observed return to equilibrium slopes. Despite trapping, substantial sediment continues to enter streams. Ninety-five suspended sediment samples from forty sites show

  10. Characterising the Geomorphic Response of a Tropical Mega-River to an Extreme, Cyclone Induced, Flood Event.

    NASA Astrophysics Data System (ADS)

    Hackney, C. R.; Leyland, J.; Darby, S. E.; Parsons, D. R.; Aalto, R. E.; Nicholas, A. P.; Best, J.

    2014-12-01

    Extreme events have the ability to induce extensive geomorphic change in fluvial systems as a result of elevated discharge levels, increased sediment transport capacity and associated changes in sheer stresses along channel boundaries. Understanding how rapid rises in water levels change flow structures and channel boundary roughness is key to understanding the relative significance of large events in terms of driving local and system wide geomorphic change. However, capturing the fluvial process dynamics in operation during such events is technically and logistically difficult, especially in the world's largest rivers. During September 2013, on the peak of the monsoon, a series of tropical cyclones induced a large flood event within the Mekong basin. At the peak of the flood wave, discharge measured ~60000 m3/s; the 11th largest flood on record. Pre and post event high resolution topographic surveys of parts of the bed and bank were captured using a combination of contiguous multibeam echo sounding (MBES) and terrestrial laser scanning (TLS) during the event. Simultaneously detailed measurements of cross sectional and near bank flow structure were acquired using an acoustic Doppler current profiler (aDcp). Together, these unique datasets can be used to characterise and assess the geomorphic impact of a cyclone induced extreme flood event on the Mekong. We show how flow structures in the near bank region evolve with stage during the extreme event and how the associated geomorphic response is modulated by the distinctive process dynamics of a mega-river.

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

    NASA Astrophysics Data System (ADS)

    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

  12. Groundwater flooding in an urbanised floodplain

    NASA Astrophysics Data System (ADS)

    MacDonald, D.; Peach, D.; Dixon, A.

    2009-12-01

    In recent years, risk management associated with groundwater flooding has been recognised as an area requiring improved understanding in the United Kingdom. Government figures suggest as many as 1.6 million properties may be at risk from this form of flooding. Further, the recently enforced EU Floods Directive requires hazard mapping associated with groundwater flooding to be undertaken. The city of Oxford is situated within a narrow valley in the upper reaches of the River Thames in the south of the United Kingdom. Although much of the city sits above the current floodplain of the River Thames, approximately 3600 properties are located within the 1 in 100 year return flood envelope. The floodplain is underlain by a shallow alluvial aquifer in good hydraulic connection with the River Thames and its tributaries. The city suffers from recurrent floods, most recently in July 2007, when a 1 in 20 year event impacted over 200 properties. A significant number of these properties were affected by flooding from rising groundwater which was either the sole cause of flooding or the initial cause prior to inundation from fluvial waters. A study has been undertaken by the British Geological Survey, in collaboration with the environment regulator and linked with the local flood risk management scheme, to assess the role of groundwater in flooding in Oxford. The study has shown that groundwater flooding in the city occurs in low-lying areas protected from direct fluvial flooding, at least in the early stages of an event, by high ground associated with urbanisation. Although direct rainfall recharge associated with extreme events can cause significant groundwater level rise in these low-lying areas, the primary mechanism for groundwater flooding is the movement of water through the permeable subsurface from fluvial flooded zones. Groundwater flooding is often the only form of flooding for the isolated low-lying areas for medium-to-high probability flood events. As a result

  13. An analysis of changes in flood quantiles at the gauge Neu Darchau (Elbe River) from 1875 to 2013

    NASA Astrophysics Data System (ADS)

    Mudersbach, Christoph; Bender, Jens; Netzel, Fabian

    2016-05-01

    Within this investigation, we focus on a detailed analysis of the discharge data of the gauge Neu Darchau (Elbe River). The Elbe River inflows onto the North Sea. The gauge Neu Darchau is the most downstream discharge gauge of the Elbe River before it becomes an estuary. We follow the questions, whether the discharge characteristics of the Elbe River have changed over the last decades and how much common flood quantiles (i.e. 100-year flood) are affected by the latest extreme events in 2002, 2006, 2011, and 2013. Hence, we conduct (i) trend and seasonality analysis and (ii) an assessment of time-dependencies of flood quantiles by using quasi non-stationary extreme value statistics with both block maxima and peak-over-threshold approaches. The (iii) significance of the changes found in flood quantiles are assessed by using a stochastic approach based on autoregressive models and Monte Carlo simulations. The results of the trend analyses do show no clear evidences for any significant trends in daily mean discharges and increasing flood frequencies. With respect to the extreme events in 2002, 2006, 2011, and 2013 our results reveal, that those events do not lead to extraordinary changes in the 100-year floods. Nevertheless, in the majority an increase in the 100-year floods over the recent decades can be stated. Although these changes are not significant, for many time series of the 100-year flood quantiles there is a clear tendency towards the upper confidence band.

  14. Influence of intra-event-based flood regime on sediment flow behavior from a typical agro-catchment of the Chinese Loess Plateau

    NASA Astrophysics Data System (ADS)

    Zhang, Le-Tao; Li, Zhan-Bin; Wang, He; Xiao, Jun-Bo

    2016-07-01

    The pluvial erosion process is significantly affected by tempo-spatial patterns of flood flows. However, despite their importance, only a few studies have investigated the sediment flow behavior that is driven by different flood regimes. The study aims to investigate the effect of intra-event-based flood regimes on the dynamics of sediment exports at Tuanshangou catchment, a typical agricultural catchment (unmanaged) in the hilly loess region on the Chinese Loess Plateau. Measurements of 193 flood events and 158 sediment-producing events were collected from Tuanshangou station between 1961 and 1969. The combined methods of hierarchical clustering approach, discriminant analysis and One-Way ANOVA were used to classify the flood events in terms of their event-based flood characteristics, including flood duration, peak discharge, and event flood runoff depth. The 193 flood events were classified into five regimes, and the mean statistical features of each regime significantly differed. Regime A includes flood events with the shortest duration (76 min), minimum flood crest (0.045 m s-1), least runoff depth (0.2 mm), and highest frequency. Regime B includes flood events with a medium duration (274 min), medium flood crest (0.206 m s-1), and minor runoff depth (0.7 mm). Regime C includes flood events with the longest duration (822 min), medium flood crest (0.236 m s-1), and medium runoff depth (1.7 mm). Regime D includes flood events with a medium duration (239 min), large flood crest (4.21 m s-1), and large runoff depth (10 mm). Regime E includes flood events with a medium duration (304 min), maximum flood crest (8.62 m s-1), and largest runoff depth (25.9 mm). The sediment yield by different flood regimes is ranked as follows: Regime E > Regime D > Regime B > Regime C > Regime A. In terms of event-based average and maximum suspended sediment concentration, these regimes are ordered as follows: Regime E > Regime D > Regime C > Regime B > Regime A. Regimes D and E

  15. Field assessment of flood event suspended sediment transport from ephemeral streams in the tropical semi-arid catchments.

    PubMed

    Ondieki, C M

    1995-03-01

    An assessment of suspended sediment transport was carried out in a number of semiarid catchments during flood events in order to quantify the degradation rates. In order to quantify these, a systematic sampling procedure of the episodic flood events was proposed for representative catchments. The procedure allows for an integration over the whole run-off episode using both the rising and falling limbs of the run-off hydrograph to compute the sediment quantities for each individual flood event.Higher sediment concentrations occurred in the rising limb than those at the recession for any stage of flow. The maximum suspended sediment concentration was observed at the peak of the flood hydrograph. An integration of the sediment concentration over its duration gave the total sediment yield from the flood event. For the ephemeral channels, only a small number of flood events were observed over a three-year experimental period each with a duration of the order of 3-6 h. It is notable that high sediment loads were associated with high flow volumes which were effectively the result of the catchment characteristics and incident rainfall causing the flood events in the respective catchments. A large percentage of the annual sediment yield from a catchment is transported by the ephemeral streams during a small number of flood events. The correct determination of the total sediment yield from any of the flood events depends entirely on the accuracy of the measurements.The understanding of run-off and sediment loss for the representative catchments aims at assisting planning, management and control of water and land resources for sustainable development in the semi-arid parts of the tropics. The sediment rates reveal the degradation of catchments which have repercussions on the crop and pasture production and this has a bearing on the soil and water conservation programmes in the delicate ecological balance of the semi-arid areas. Further, these rates will determine the lifespan

  16. Using an extended 2D hydrodynamic model for evaluating damage risk caused by extreme rain events: Flash-Flood-Risk-Map (FFRM) Upper Austria

    NASA Astrophysics Data System (ADS)

    Humer, Günter; Reithofer, Andreas

    2016-04-01

    at 20th of June 2012, based on open data sources of geology, soil and land use. The aim of FFRM is to provide an estimation of the damage risk caused by flash-floods for the whole of Upper Austria. To address the hazard, inundation depths were calculated with the extended 2D-model using design rains with an 100-year return period provided by the Environmental Ministry [7]. The potential damage was calculated using damage functions, which were derived from our experience from damage surveys of past events in Austria and according to guidelines for determination of cost-benefit-ratios for flood protection measures [8]. The greatest difficulty was to get appropriate data for the distribution of houses and industrial plants. Zoning plans provide good information on spatial distribution of residential, commercial and industrial areas, but does not contain information on the kind of industry, which is essential for estimating absolute damage values. To get a first idea detailed information from surveyed areas was intersected with the zoning plan, which provides an average damage in the respective zones. The first results can be found on www.waterviewer.com and will be updated with the further development of the project. [1] URBAS, risk management of extreme flooding events - prediction and management of flash floods in urban areas, www.urbanesturzfluten.de, prompted on 13th of November 2014 [2] Società Meteorologica Italiana (SMI), http://www.nimbus.it/eventi/2013/130624flashfloodRimini.pdf, prompted on 13th of November 2014 [3]Newspaper "Österreich", http://www.oe24.at/oesterreich/chronik/Sturzflut-Regen-legt-Ost-Oesterreich-lahm/1509113, prompted on 13th of November 2014 [4] Newspaper „Oberösterreichische Nachrichten", http://www.nachrichten.at/oberoesterreich/Unwetter-Mure-riss-Strasse-mit-Wohnhaus-in-Gosau-gefaehrdet;art4,911288 , prompted on 13th of November 2014 [5] Sharing Water-related Information to Tackle Changes in the Hydrosphere - for Operational Needs

  17. 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

    NASA Astrophysics Data System (ADS)

    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

  18. Reconstruction and numerical modelling of a flash flood event: Atrani 2010

    NASA Astrophysics Data System (ADS)

    Ciervo, F.; Papa, M. N.; Medina, V.; Bateman, A.

    2012-04-01

    The work intends to reproduce the flash-flood event that occurred in Atrani (Amalfi Coast - Southern Italy) on the 9 September 2010. In the days leading up to the event, intense low pressure system affected the North Europe attracting hot humid air masses from the Mediterranean areas and pushing them to the southern regions of Italy. These conditions contributed to the development of strong convective storm systems, Mesoscale Convective Systems (MCS) type. The development of intense convective rain cells, over an extremely confined areas, leaded to a cumulative daily rainfall of 129.2 mm; the maximum precipitation in 1hr was 19.4mm. The Dragone river is artificially forced to flow underneath the urban estate of Atrani through a culvert until it finally flows out into the sea. In correspondence of the culvert inlet a minor fraction of the water discharge (5.9m^3/s), skimming over the channel cover, flowed on the street and invaded the village. The channelized flow generated overpressure involving the breaking of the cover of culvert slab and caused a new discharge inlet (20 m^3/s) on the street modifying the downstream flood dynamics. Information acquired, soon after the event, through the local people interviews and the field measurements significantly contributed to the rainfall event reconstruction and to the characterization of the induced effects. In absence of hydrometric data, the support of the amateur videos was of crucial importance for the hydraulic model development and calibration. A geomorphology based rainfall-runoff model, WFIUH type (Instantaneous Unit Hydrograph Width Function), is implemented to extract the hydrograph of the hydrological event. All analysis are performed with GIS support basing on a Digital Terrain System (DTM) 5x5m. Two parameters have been used to calibrate the model: the average watershed velocity (Vmean = 0.08m/s) and hydrodynamic diffusivity (D=10E^-6 m^2/s). The model is calibrated basing on the peak discharge assessed value

  19. Ernst Mach on the vestibular organ 100 years ago.

    PubMed

    Henn, V; Young, L R

    1975-01-01

    Ernst Mach (1838-1916) performed pioneering research on vestibular function 100 years ago. His experiments were mainly psychophysical and included measurements of threshold and study of the vestibular-visual interaction. Contrary to general belief, he concluded that the adequate stimulus for the semicircular canals must be pressure. He presented evidence specifically against the sustained endolymph flow theory of Breuer (1874) and Crum Brown (1874), with which he is frequently associated. Excerpts from his publications are given and their relevance to current research is discussed. PMID:1093083

  20. Ragnar Granit 100 years--memories and reflections.

    PubMed

    Kernell, D

    2000-12-01

    The Swedish-Finnish Nobel laureate Ragnar Granit, born 100 years ago, is commemorated in a brief article by one of his former PhD students and collaborators. After a short account of Granit's life and scientific career, special attention is given to Granit's role as a teacher in research training and his published thoughts on this matter, partly reflecting Granit's own experience as a "postdoc" in the laboratory of Sherrington (Oxford). The article includes personal recollections of how it was to work together with Granit in his laboratory. PMID:11232369

  1. Spatially distributed modelling of surface water-groundwater exchanges during overbank flood events - a case study at the Garonne River

    NASA Astrophysics Data System (ADS)

    Bernard-Jannin, Léonard; Brito, David; Sun, Xiaoling; Jauch, Eduardo; Neves, Ramiro; Sauvage, Sabine; Sánchez-Pérez, José-Miguel

    2016-08-01

    Exchanges between surface water (SW) and groundwater (GW) are of considerable importance to floodplain ecosystems and biogeochemical cycles. Flood events in particular are important for riparian water budget and element exchanges and processing. However SW-GW exchanges present complex spatial and temporal patterns and modelling can provide useful knowledge about the processes involved at the scale of the reach and its adjacent floodplain. This study used a physically-based, spatially-distributed modelling approach for studying SW-GW exchanges. The modelling in this study is based on the MOHID Land model, combining the modelling of surface water flow in 2D with the Saint-Venant equation and the modelling of unsaturated groundwater flow in 3D with the Richards' equation. Overbank flow during floods was also integrated, as well as water exchanges between the two domains across the entire floodplain. Conservative transport simulations were also performed to study and validate the simulation of the mixing between surface water and groundwater. The model was applied to the well-monitored study site of Monbéqui (6.6 km²) in the Garonne floodplain (south-west France) for a five-month period and was able to represent the hydrology of the study area. Infiltration (SW to GW) and exfiltration (SW to GW) were characterised over the five-month period. Results showed that infiltration and exfiltration exhibited strong spatiotemporal variations, and infiltration from overbank flow accounted for 88% of the total simulated infiltration, corresponding to large flood periods. The results confirmed that overbank flood events played a determinant role in floodplain water budget and SW-GW exchanges compared to smaller (below bankfull) flood events. The impact of floods on water budget appeared to be similar for flood events exceeding a threshold corresponding to the five-year return period event due to the study area's topography. Simulation of overbank flow during flood events was an

  2. A Participatory Modeling Application of a Distributed Hydrologic Model in Nuevo Leon, Mexico for the 2010 Hurricane Alex Flood Event

    NASA Astrophysics Data System (ADS)

    Baish, A. S.; Vivoni, E. R.; Payan, J. G.; Robles-Morua, A.; Basile, G. M.

    2011-12-01

    A distributed hydrologic model can help bring consensus among diverse stakeholders in regional flood planning by producing quantifiable sets of alternative futures. This value is acute in areas with high uncertainties in hydrologic conditions and sparse observations. In this study, we conduct an application of the Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator (tRIBS) in the Santa Catarina basin of Nuevo Leon, Mexico, where Hurricane Alex in July 2010 led to catastrophic flooding of the capital city of Monterrey. Distributed model simulations utilize best-available information on the regional topography, land cover, and soils obtained from Mexican government agencies or analysis of remotely-sensed imagery from MODIS and ASTER. Furthermore, we developed meteorological forcing for the flood event based on multiple data sources, including three local gauge networks, satellite-based estimates from TRMM and PERSIANN, and the North American Land Data Assimilation System (NLDAS). Remotely-sensed data allowed us to quantify rainfall distributions in the upland, rural portions of the Santa Catarina that are sparsely populated and ungauged. Rural areas had significant contributions to the flood event and as a result were considered by stakeholders for flood control measures, including new reservoirs and upland vegetation management. Participatory modeling workshops with the stakeholders revealed a disconnect between urban and rural populations in regard to understanding the hydrologic conditions of the flood event and the effectiveness of existing and potential flood control measures. Despite these challenges, the use of the distributed flood forecasts developed within this participatory framework facilitated building consensus among diverse stakeholders and exploring alternative futures in the basin.

  3. Reconstruction of late Holocene flooding events in the Gulf of Genoa, Ligurian Sea

    NASA Astrophysics Data System (ADS)

    Lamy, Frank; Kaiser, Jerome; Arz, Helge; Ruggieri, Nicoletta

    2014-05-01

    The area of the Gulf of Genoa contains a large potential for studying past rainfall variability as it is one of the major Mediterranean centers for cyclogenesis. The strongest depressions form when cold arctic/subarctic air outbreaks flow through the Rhone valley into the Gulf of Lions and the Ligurian Sea during late autumn when sea surface temperatures are still relatively high. The cyclones are more frequent during negative Arctic Oscillation / North Atlantic Oscillation (AO/NAO). As well, significant negative correlations exist between AO/NAO and winter/spring precipitation and river discharge in northwestern Italy. Related autumn flooding events occur at interannual time-scales and may cause substantial damage in the region. Moreover, the "Genoa Cyclones" sometimes move northeastwards into eastern/central Europe (the so-called "Vb" cyclone track) and contributed for example substantially to the Elbe flooding in 2002. During R/V Poseidon cruise P413 (May 2011), ca. 60 sediment cores were taken along the Ligurian shelf, continental slope and in the basin between off Livorno and the French border. Coring profiles from the coastal area to the deep basin allow reconstructing past environmental variability over the last ca. 90000 years with sedimentation rates varying between ca. 0.5 cm*yr-1 for the latest Holocene to ca. 10 cm*kyr-1 for the last glacial. On the shelf, mud lenses with exceptionally high sedimentation rates reaching several m/kyr provide detailed Holocene records of changes in terrigenous sediment input primarily related to autumn rainfall events. We performed high resolution (mm) analyses of major elements using XRF core-scanning on two cores with extremely high resolution (0.2-0.4 cm/year) over the last 2.5 kyr BP. Typical elements of detrital origin (i.e. Ti, Fe) present a very high variability, probably related to flooding events during the late Holocene. Spectral analysis on these records reveals significant periodicities around 4-5 and 7

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Numerical simulation diagnostics of a flash flood event in Jeddah, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Samman, Ahmad

    On 26 January 2011, a severe storm hit the city of Jeddah, the second largest city in the Kingdom of Saudi Arabia. The storm resulted in heavy rainfall, which produced a flash flood in a short period of time. This event caused at least eleven fatalities and more than 114 injuries. Unfortunately, the observed rainfall data are limited to the weather station at King Abdul Aziz International airport, which is north of the city, while the most extreme precipitation occurred over the southern part of the city. This observation was useful to compare simulation result even though it does not reflect the severity of the event. The Regional Atmospheric Modeling System (RAMS) developed at Colorado State University was used to study this storm event. RAMS simulations indicted that a quasi-stationary Mesoscale convective system developed over the city of Jeddah and lasted for several hours. It was the source of the huge amount of rainfall. The model computed a total rainfall of more than 110 mm in the southern part of the city, where the flash flood occurred. This precipitation estimation was confirmed by the actual observation of the weather radar. While the annual rainfall in Jeddah during the winter varies from 50 to 100 mm, the amount of the rainfall resulting from this storm event exceeded the climatological total annual rainfall. The simulation of this event showed that warm sea surface temperature, combined with high humidity in the lower atmosphere and a large amount of convective available potential energy (CAPE) provided a favorable environment for convection. It also showed the presence of a cyclonic system over the north and eastern parts of the Mediterranean Sea, and a subtropical anti-cyclone over Northeastern Africa that contributed to cold air advection bringing cold air to the Jeddah area. In addition, an anti-cyclone (blocking) centered over east and southeastern parts of the Arabian Peninsula and the Arabian Sea produced a low level jet over the southern

  6. A humanitarian preparedness toolbox: estimating flood affected figures and exposure of livelihoods to future floods events, using freely available datasets.

    NASA Astrophysics Data System (ADS)

    Paron, Paolo; von Hagen, Craig; Peppino Disperati, Stefano; Hermansyah, Budi; Shaheen, Imra; Jan, Qasim; Berloffa, Andrea; Khan, Ruby; Fakhre, Alam

    2013-04-01

    Pakistan is highly disaster-prone, with three major flood disasters occurred in the past three years, yet major losses are not inevitable. Farming-based families still struggling to recover from 2010 and 2011 floods have again faced another bad monsoon season in 2012. Meanwhile, the likelihood of yet more natural disasters in the future is high as the phenomenon of climate change is increasing the prevalence of extreme weather conditions. Even with less rainfall, the risk of flooding this year remains high, while many villages have not fully recovered from the 2011-2012 floods. It is of utmost importance to support the most vulnerable rural communities to recover their flood-affected livelihoods. In the meantime, prioritizing disaster preparedness through flood hazard and population mapping is crucial to ensure that realistic contingency plans are in place to deliver an effective and timely response and reduce the impact of floods before they strike. To increase preparedness in future floods, an integrated approach that builds the resilience of flood affected community and enhances emergency preparedness based on reliable data is critical. We present here the innovative methodology developed for estimating population and livelihood that could potentially be affected by a future flood scenario, as well as a methodology for knowing where these people are located, along with an overview of their livelihood pattern. This project has used only freely available dataset, due to the urgency of providing a toolbox to the humanitarian community and the absence of readily available detailed information on natural hazards and exposure in Pakistan. The estimated figures resulting from this project, would provide the Food Security stakeholders with adequate information and data for programming a tailored response in case of floods during future monsoon season. For the purpose of preparedness, understanding the risks, and its potential magnitude, is crucial to provide decision

  7. Quality control of the RMS US flood model

    NASA Astrophysics Data System (ADS)

    Jankowfsky, Sonja; Hilberts, Arno; Mortgat, Chris; Li, Shuangcai; Rafique, Farhat; Rajesh, Edida; Xu, Na; Mei, Yi; Tillmanns, Stephan; Yang, Yang; Tian, Ye; Mathur, Prince; Kulkarni, Anand; Kumaresh, Bharadwaj Anna; Chaudhuri, Chiranjib; Saini, Vishal

    2016-04-01

    The RMS US flood model predicts the flood risk in the US with a 30 m resolution for different return periods. The model is designed for the insurance industry to estimate the cost of flood risk for a given location. Different statistical, hydrological and hydraulic models are combined to develop the flood maps for different return periods. A rainfall-runoff and routing model, calibrated with observed discharge data, is run with 10 000 years of stochastic simulated precipitation to create time series of discharge and surface runoff. The 100, 250 and 500 year events are extracted from these time series as forcing for a two-dimensional pluvial and fluvial inundation model. The coupling of all the different models which are run on the large area of the US implies a certain amount of uncertainty. Therefore, special attention is paid to the final quality control of the flood maps. First of all, a thorough quality analysis of the Digital Terrain model and the river network was done, as the final quality of the flood maps depends heavily on the DTM quality. Secondly, the simulated 100 year discharge in the major river network (600 000 km) is compared to the 100 year discharge derived using extreme value distribution of all USGS gauges with more than 20 years of peak values (around 11 000 gauges). Thirdly, for each gauge the modelled flood depth is compared to the depth derived from the USGS rating curves. Fourthly, the modelled flood depth is compared to the base flood elevation given in the FEMA flood maps. Fifthly, the flood extent is compared to the FEMA flood extent. Then, for historic events we compare flood extents and flood depths at given locations. Finally, all the data and spatial layers are uploaded on geoserver to facilitate the manual investigation of outliers. The feedback from the quality control is used to improve the model and estimate its uncertainty.

  8. A statistical forecast model for Tropical Cyclone Rainfall and flood events for the Hudson River

    NASA Astrophysics Data System (ADS)

    Cioffi, Francesco; Conticello, Federico; Hall, Thimoty; Lall, Upmanu; Orton, Philip

    2014-05-01

    Tropical Cyclones (TCs) lead to potentially severe coastal flooding through wind surge and also through rainfall-runoff processes. There is growing interest in modeling these processes simultaneously. Here, a statistical approach that can facilitate this process is presented with an application to the Hudson River Basin that is associated with the New York City metropolitan area. Three submodels are used in sequence. The first submodel is a stochastic model of the complete life cycle of North Atlantic (NA) tropical cyclones developed by Hall and Yonekura (2011). It uses archived data of TCs throughout the North Atlantic to estimate landfall rates at high geographic resolution as a function of the ENSO state and of sea surface temperature (SST). The second submodel translates the attributes of a tropical cyclone simulated by the first model to rainfall intensity at selected stations within the watershed of Hudson River. Two different approaches are used and compared: artificial neural network (ANN) and k-nearest neighbor (KNN). Finally, the third submodel transforms, once again, by using an ANN approach and KNN, the rainfall intensities, calculated for the ensemble of the stations, to the streamflows at specific points of the tributaries of the Hudson River. These streamflows are to be used as inputs in a hydrodynamic model that includes storm surge surge dynamics for the simulation of coastal flooding along the Hudson River. Calibration and validation of the model is carried out by using, selected tropical cyclone data since 1950, and hourly station rainfall and streamflow recorded for such extreme events. Four stream gauges (Troy dam, Mohawk River at Cohoes, Mohawk River diversion at Crescent Dam, Hudson River above lock one nr Waterford), a gauge from a tributary in the lower Hudson River, and over 20 rain gauges are used. The performance of the proposed model as tool for storm events is then analyzed and discussed.

  9. Estuarine ecosystem response to three large-scale Mississippi River flood diversion events.

    PubMed

    Roy, Eric D; White, John R; Smith, Emily A; Bargu, Sibel; Li, Chunyan

    2013-08-01

    Large inflows of nitrogen (N)-rich freshwater to estuaries can lead to expressions of eutrophication including harmful algal blooms of cyanobacteria (CyanoHABs). Lake Pontchartrain is a large, oligohaline estuary that occasionally receives episodic diversions of N-rich Mississippi River water via the Bonnet Carré Spillway to alleviate flood threats to New Orleans, LA. The extreme flood stage of the Lower Mississippi River in May 2011 prompted the tenth opening of the spillway since 1937. The 2011 opening occurred later in the season than the previous two lower discharge events (1997 and 2008) and was characterized by dissolved inorganic N loads 1.7 and 2.6 times greater than the 1997 and 2008 events, respectively. Rapid depletion of riverine nitrate (21 days) occurred post-spillway closure in 2011 with no associated CyanoHAB and was followed by an internal pulse of phosphorus (P) from sediments to restore N-limitation. Our analysis of recent spillway openings indicates that there is not a simple stimulus-response relationship between N loading and CyanoHAB formation. We investigate the systemic causal relationships that determine ecosystem response to these nutrient-rich freshwater inflows and highlight several important parameters including: external N loading, timing, magnitude, plume hydrodynamics, nutrient molar ratios, internal P loading, weather, and northern tributary discharge. Our results suggest that the turbulent, fluctuating environment and nutrient composition during diversions does not favor CyanoHAB formation and that the immense size and timing of the 2011 diversion may have resulted in near complete post-diversion CyanoHAB suppression by hydraulic flushing. PMID:23685135

  10. A climate-based multivariate extreme emulator of met-ocean-hydrological events for coastal flooding

    NASA Astrophysics Data System (ADS)

    Camus, Paula; Rueda, Ana; Mendez, Fernando J.; Tomas, Antonio; Del Jesus, Manuel; Losada, Iñigo J.

    2015-04-01

    Atmosphere-ocean general circulation models (AOGCMs) are useful to analyze large-scale climate variability (long-term historical periods, future climate projections). However, applications such as coastal flood modeling require climate information at finer scale. Besides, flooding events depend on multiple climate conditions: waves, surge levels from the open-ocean and river discharge caused by precipitation. Therefore, a multivariate statistical downscaling approach is adopted to reproduce relationships between variables and due to its low computational cost. The proposed method can be considered as a hybrid approach which combines a probabilistic weather type downscaling model with a stochastic weather generator component. Predictand distributions are reproduced modeling the relationship with AOGCM predictors based on a physical division in weather types (Camus et al., 2012). The multivariate dependence structure of the predictand (extreme events) is introduced linking the independent marginal distributions of the variables by a probabilistic copula regression (Ben Ayala et al., 2014). This hybrid approach is applied for the downscaling of AOGCM data to daily precipitation and maximum significant wave height and storm-surge in different locations along the Spanish coast. Reanalysis data is used to assess the proposed method. A commonly predictor for the three variables involved is classified using a regression-guided clustering algorithm. The most appropriate statistical model (general extreme value distribution, pareto distribution) for daily conditions is fitted. Stochastic simulation of the present climate is performed obtaining the set of hydraulic boundary conditions needed for high resolution coastal flood modeling. References: Camus, P., Menéndez, M., Méndez, F.J., Izaguirre, C., Espejo, A., Cánovas, V., Pérez, J., Rueda, A., Losada, I.J., Medina, R. (2014b). A weather-type statistical downscaling framework for ocean wave climate. Journal of

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

    USGS Publications Warehouse

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

    2006-01-01

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

  12. 100 years of sedimentation study by the USGS

    USGS Publications Warehouse

    Glysson, G. Douglas

    1989-01-01

    On January 15, 1889, the U.S. Geological Survey began collecting sediment data on the Rio Grande at Embudo, New Mexico. During the past 100 years the U.S. Geological Survey's Water Resources Division (WRD) has collected daily sediment data at more than 1,200 sites. Projects have addressed the problems associated with reservoir construction, agricultural irrigation projects, energy production, and transport and deposition of pollutants sorbed to sediments. The Survey has been active as a charter member of the Federal Interagency Sediment Project and currently has three full-time hydrologists working on the project. The WRD's sediment-research projects have covered a wide variety of subjects from the fundamental theories of resistance to flow and sediment transport in alluvial channels to lunar erosion mechanisms.

  13. Revisiting the 100 Year Old Radioactivity Lectures of Frederick Soddy

    NASA Astrophysics Data System (ADS)

    Hampton, Christine

    2008-04-01

    Between 1908 and 1922, Frederick Soddy, MA., FRS (Dr. Lee`s Professor of Inorganic and Physical Chemistry, Univ. of Oxford) published four editions of a compendium of his experimental lectures delivered at the University of Glasgow, under the title ``The Interpretation of Radium, and the Structure of the Atom''. Professor Soddy taught his students about `radium writing' and the emanation of radium. He presented a radium clock designed by Professor Strutt; showed students `Pleochroic Halos'; and described the separation of `ionium' from its isotope, thorium. The process of constructing a cohesive logic to empirical observations of this newly discovered phenomenon of radioactivity was a challenging one. Some aspects did not stand the test of time. However, revisiting these lectures after 100 years gives us fascinating insight into the mental processes of the early pioneers in radioactivity.

  14. Opening the 100-Year Window for Time-Domain Astronomy

    NASA Astrophysics Data System (ADS)

    Grindlay, Jonathan; Tang, Sumin; Los, Edward; Servillat, Mathieu

    2012-04-01

    The large-scale surveys such as PTF, CRTS and Pan-STARRS-1 that have emerged within the past 5 years or so employ digital databases and modern analysis tools to accentuate research into Time Domain Astronomy (TDA). Preparations are underway for LSST which, in another 6 years, will usher in the second decade of modern TDA. By that time the Digital Access to a Sky Century @ Harvard (DASCH) project will have made available to the community the full sky Historical TDA database and digitized images for a century (1890-1990) of coverage. We describe the current DASCH development and some initial results, and outline plans for the ``production scanning'' phase and data distribution which is to begin in 2012. That will open a 100-year window into temporal astrophysics, revealing rare transients and (especially) astrophysical phenomena that vary on time-scales of a decade. It will also provide context and archival comparisons for the deeper modern surveys.

  15. Estimation of Future Changes in Flood Disaster Losses

    NASA Astrophysics Data System (ADS)

    Konoshima, L.; Hirabayashi, Y.; Roobavannan, M.

    2012-12-01

    Disaster losses can be estimated by hazard intensity, exposure, and vulnerabilities. Many studies have addressed future economic losses from river floods, most of which are focused on Europe (Bouwer et al, 2010). Here flood disaster losses are calculated using the output of multi-model ensembles of CMIP5 GCMs in order to estimate the changes in damage loss due to climate change. For the global distribution of the expected future population and GDP, the ALPS scenario of RITE is population for is used. Here, flood event is defined as river discharge that has a probability of having 100 years return period. The time series of annual maximum daily discharge was fitted using moment fitting method for GEV distribution at each grid. L-moment method (Hosking and Wallis 1997) is used for estimating the parameters of distribution. For probability distribution, Gumbel distribution and Generalized Extreme Value (GEV) distribution were tested to see the future changes of 100-year value. Using the calculation of 100-year flood of present condition and annual maximum discharge for present and future climate conditions, the area exceeding 100-year flood is calculated for each 30 years. And to estimate the economic impact of future changes in occurrence of 100-year flood, affected total GDP is calculated by multiplying the affected population with country's GDP in areas exceeding 100-year flood value of present climate for each present and future conditions. The 100-year flood value is fixed with the value of present condition in calculating the affected value on the future condition. To consider the effect of the climatic condition and changes of economic growth, the regions are classified by continents. The Southeast Asia is divided into Japan and South Korea (No.1) and other countries (No.2), since the GDP and GDP growth rate within the two areas is quite different compared to other regions. Figure 1 shows the average and standard deviation (1-sigma) of future changing ratio

  16. A quality assessment framework for natural hazard event documentations: application to trans-basin flood reports in Germany

    NASA Astrophysics Data System (ADS)

    Uhlemann, S.; Thieken, A. H.; Merz, B.

    2013-02-01

    Written sources that aim at documenting and analysing a particular natural hazard event in the recent past are published at vast majority as grey literature (e.g. as technical reports) and therefore outside of the scholarly publication routes. In consequence, the application of event specific documentations in natural hazard research has been constrained by barriers in accessibility and concerns of credibility towards these sources and by limited awareness of their content and its usefulness for research questions. In this study we address the concerns of credibility for the first time and present a quality assessment framework for written sources from a user's perspective, i.e. we assess the documents' fitness for use to enhance the understanding of trans-basin floods in Germany in the period 1952-2002. The framework is designed to be generally applicable for any natural hazard event documentation and assesses the quality of a document addressing accessibility as well as representational, contextual, and intrinsic dimensions of quality. We introduce an ordinal scaling scheme to grade the quality in the single quality dimensions and the Pedigree score which serves as a measure for the overall document quality. We present results of an application of the framework to a set of 133 event specific documentations relevant for understanding trans-basin floods in Germany. Our results show that the majority of flood event specific reports are of a good quality, i.e. they are well enough drafted, largely accurate and objective, and contain a substantial amount of information on the sources, pathways and receptors/consequences of the floods. The validation of our results against assessments of two independent peers confirms the objectivity and transparency of the quality assessment framework. Using an example flood event that occurred in October/November 1998 we demonstrate how the information from multiple reports can be synthesised under consideration of their quality.

  17. A quality assessment framework for natural hazard event documentation: application to trans-basin flood reports in Germany

    NASA Astrophysics Data System (ADS)

    Uhlemann, S.; Thieken, A. H.; Merz, B.

    2014-02-01

    Written sources that aim at documenting and analysing a particular natural hazard event in the recent past are published at vast majority as grey literature (e.g. as technical reports) and therefore outside of the scholarly publication routes. In consequence, the application of event-specific documentation in natural hazard research has been constrained by barriers in accessibility, concerns of credibility towards these sources and by limited awareness of their content and its usefulness for research questions. In this study we address the concerns of credibility for the first time and present a quality assessment framework for written sources from a user's perspective, i.e. we assess the documents' fitness for use to enhance the understanding of trans-basin floods in Germany in the period 1952-2002. The framework is designed to be generally applicable for any natural hazard event documentation and assesses the quality of a document, addressing accessibility as well as representational, contextual, and intrinsic dimensions of quality. We introduce an ordinal scaling scheme to grade the quality in the individual quality dimensions and the Pedigree score which serves as a measure for the overall document quality. We present results of an application of the framework to a set of 133 cases of event-specific documentation relevant for understanding trans-basin floods in Germany. Our results show that the majority of flood event-specific reports are of good quality, i.e. they are well enough drafted, largely accurate and objective, and contain a substantial amount of information on the sources, pathways and receptors/consequences of the floods. The validation of our results against assessments of two independent peers confirms the objectivity and transparency of the quality assessment framework. Using an example flood event that occurred in October/November 1998 we demonstrate how the information from multiple reports can be synthesised.

  18. Developing tools and procedures for the collection and storage of flood damage data in the aftermath of flood events: the Poli-RISPOSTA project

    NASA Astrophysics Data System (ADS)

    Molinari, Daniela; Ballio, Francesco; Mazuran, Mirjana; Arias, Carolina; Minucci, Guido; Atun, Funda; Ardagna, Danilo

    2015-04-01

    According to a recent JRC report (De Groeve et al., Recording disaster losses, 2013), no measure better than loss over time can provide objective understanding of the path towards resilience. Moreover, damage data collected in the aftermath of floods supply the knowledge base on which a blend of actions can be performed, both in the short and mid time after the occurrence of a flood; among them: the identification of priorities for intervention during emergencies, the definition of compensation schemes, the understanding of damage mechanisms and of the fragilities of the flooded areas so as to improve/reform current risk mitigation strategies (also by means of improved flood damage models). Objective "measurement" of flood losses remains inadequate to meet the above objectives. This is due to a number of reasons that include: the diversity of intent for data collection, the lack of standardization on how to collect and storage data (including the lack of agreed definitions) among responsible subjects, and last but not least a lack of legislation to support the collection process. In such a context, the aim of this contribution is to discuss the results from the Poli-RISPOSTA (stRumentI per la protezione civile a Supporto delle POpolazioni nel poST Alluvione) project, a research project founded by Politecnico di Milano which is intended to develop tools and procedures for the collection and storage of high quality, consistent and reliable flood damage data. Specific objectives of Poli-RISPOSTA are: - Develop an operational procedure for collecting, storing and analyzing all damage data, in the aftermath of flood events. Collected data are intended to support a variety of actions, namely: loss accounting, disaster forensic, damage compensation and flood risk modelling; - Develop educational material and modules for training practitioners in the use of the procedure; - Develop enhanced IT tools to support the procedure, easing as much as possible the collection of

  19. Rainfall estimation in the context of post-event flash flood analysis

    NASA Astrophysics Data System (ADS)

    Delrieu, Guy; Boudevillain, Brice; Bouilloud, Ludovic

    2010-05-01

    Due to their spatial coverage and space-time resolution, operational weather radar networks offer unprecedented opportunities for the observation of flash flood generating storms. However, the radar rainfall estimation quality highly depends on the relative locations of the event and the radar(s). A mountainous environment obviously adds to the complexity of the radar quantitative precipitation estimation (QPE). A pragmatic methodology was developed within the EC-funded HYDRATE project to take the best benefit of the existing rainfall observations (radar and raingauge data) for given flash-flood cases: 1) A precise documentation of the radar characteristics (location, parameters, operating protocol, data archives and processing) needs first to be established. The radar(s) detection domain(s) can then be characterized using the "hydrologic visibility" concepts (Pellarin et al. J Hydrometeor 3(5) 539-555 2002). 2) Rather dense raingauge observations (operational, amateur) are usually available at the event time scale while few raingauge time series exist at the hydrologic time steps. Such raingauge datasets need to be critically analysed; a geostatistical approach is proposed for this task. 3) A number of identifications can be implemented prior to the radar data re-processing: a) Special care needs to be paid to (residual) ground clutter which has a dramatic impact of radar QPE. Dry-weather maps and rainfall accumulation maps may help in this task. b) Various sources of power losses such as screening, wet radome, attenuation in rain need to be identified and quantified. It will be shown that mountain returns can be used to quantify attenuation effects at C-band. c) Radar volume data is required to characterize the vertical profile of reflectivity (VPR), eventually conditioned on rain type (convective, widespread). When such data is not available, knowledge of the 0°C isotherm and the scanning protocol may help detecting bright-band contaminations that critically

  20. Rainfall estimation in the context of post-event flash flood analysis

    NASA Astrophysics Data System (ADS)

    Bouilloud, L.; Delrieu, G.; Boudevillain, B.

    2009-04-01

    Due to their spatial coverage and space-time resolution, operational weather radar networks offer unprecedented opportunities for the observation of flash flood generating storms. However, the radar rainfall estimation quality highly depends on the relative locations of the event and the radar(s). A mountainous environment obviously adds to the complexity of the radar quantitative precipitation estimation (QPE). A pragmatic methodology is proposed to take the best benefit of the existing rainfall observations (radar and raingauge data) for given flash-flood cases: 1) A precise documentation of the radar characteristics (location, parameters, operating protocol, data archives and processing) needs first to be established. The radar(s) detection domain(s) can then be characterized using the "hydrologic visibility" concepts (Pellarin et al. J Hydrometeor 3(5) 539-555 2002). 2) Rather dense raingauge observations (operational, amateur) are usually available at the event time scale while few raingauge time series exist at the hydrologic time steps. Such raingauge datasets need to be critically analysed; a geostatistical approach is proposed for this task. 3) A number of identifications can be implemented prior to the radar data re-processing: a) Special care needs to be paid to (residual) ground clutter which has a dramatic impact of radar QPE. Dry-weather maps and rainfall accumulation maps may help in this task. b) Various sources of power losses such as screening, wet radome, attenuation in rain need to be identified and quantified. It will be shown that mountain returns can be used to quantify attenuation effects at C-band. c) Radar volume data is required to characterize the vertical profile of reflectivity (VPR), eventually conditioned on rain type (convective, widespread). When such data is not available, knowledge of the 0°C isotherm and the scanning protocol may help detecting bright-band contaminations that critically affect radar QPE. d) With conventional

  1. Sediment delivery ratio of single flood events and the influencing factors in a headwater basin of the Chinese Loess Plateau.

    PubMed

    Zheng, Mingguo; Liao, Yishan; He, Jijun

    2014-01-01

    Little is known about the sediment delivery of single flood events although it has been well known that the sediment delivery ratio at the inter-annual time scale is close to 1 in the Chinese Loess Plateau. This study examined the sediment delivery of single flood events and the influencing factors in a headwater basin of the Loess Plateau, where hyperconcentrated flows are dominant. Data observed from plot to subwatershed over the period from 1959 to 1969 were presented. Sediment delivery ratio of a single event (SDRe) was calculated as the ratio of sediment output from the subwatershed to sediment input into the channel. It was found that SDRe varies greatly for small events (runoff depth <5 mm or rainfall depth <30 mm) and remains fairly constant (approximately between 1.1 and 1.3) for large events (runoff depth >5 mm or rainfall depth >30 mm). We examined 11 factors of rainfall (rainfall amount, rainfall intensity, rainfall kinetic energy, rainfall erosivity and rainfall duration), flood (area-specific sediment yield, runoff depth, peak flow discharge, peak sediment concentration and flood duration) and antecedent land surface (antecedent precipitation) in relation to SDRe. Only the peak sediment concentration significantly correlates with SDRe. Contrary to popular belief, channel scour tends to occur in cases of higher peak sediment concentrations. Because small events also have chances to attain a high sediment concentration, many small events (rainfall depth <20 mm) are characterized by channel scour with an SDRe larger than 1. Such observations can be related to hyperconcentrated flows, which behave quite differently from normal stream flows. Our finding that large events have a nearly constant SDRe is useful for sediment yield predictions in the Loess Plateau and other regions where hyperconcentrated flows are well developed. PMID:25389752

  2. Sediment Delivery Ratio of Single Flood Events and the Influencing Factors in a Headwater Basin of the Chinese Loess Plateau

    PubMed Central

    Zheng, Mingguo; Liao, Yishan; He, Jijun

    2014-01-01

    Little is known about the sediment delivery of single flood events although it has been well known that the sediment delivery ratio at the inter-annual time scale is close to 1 in the Chinese Loess Plateau. This study examined the sediment delivery of single flood events and the influencing factors in a headwater basin of the Loess Plateau, where hyperconcentrated flows are dominant. Data observed from plot to subwatershed over the period from 1959 to 1969 were presented. Sediment delivery ratio of a single event (SDRe) was calculated as the ratio of sediment output from the subwatershed to sediment input into the channel. It was found that SDRe varies greatly for small events (runoff depth <5 mm or rainfall depth <30 mm) and remains fairly constant (approximately between 1.1 and 1.3) for large events (runoff depth >5 mm or rainfall depth >30 mm). We examined 11 factors of rainfall (rainfall amount, rainfall intensity, rainfall kinetic energy, rainfall erosivity and rainfall duration), flood (area-specific sediment yield, runoff depth, peak flow discharge, peak sediment concentration and flood duration) and antecedent land surface (antecedent precipitation) in relation to SDRe. Only the peak sediment concentration significantly correlates with SDRe. Contrary to popular belief, channel scour tends to occur in cases of higher peak sediment concentrations. Because small events also have chances to attain a high sediment concentration, many small events (rainfall depth <20 mm) are characterized by channel scour with an SDRe larger than 1. Such observations can be related to hyperconcentrated flows, which behave quite differently from normal stream flows. Our finding that large events have a nearly constant SDRe is useful for sediment yield predictions in the Loess Plateau and other regions where hyperconcentrated flows are well developed. PMID:25389752

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

    NASA Astrophysics Data System (ADS)

    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

  4. A meteo-hydrological modeling study for flood events in the Ofanto river catchment

    NASA Astrophysics Data System (ADS)

    Verri, Giorgia; Pinardi, Nadia; Tribbia, Joseph; Gochis, David; Navarra, Antonio; Coppini, Giovanni; Vukicevic, Tomislava

    2016-04-01

    The aim of this study is to evaluate the capability of our meteo-hydrological modeling system to simulate the local water cycle of the Ofanto river catchment. The basin of the Ofanto River, flowing through the Southern Italy and ending into the Adriatic Sea, is chosen as a challenging case study to test the modeling chain since the Southern Italy is known to be a region subject to flash flood events (Delrieu et al, 2005; Davolio et al, 2008; Miglietta et al., 2008). Moreover the Ofanto River is a semi-perennial river, its annual averaged discharge is low (15 m3s‑1following Raicich, 1996) but may significantly increase when heavy rain events occur. We select the first 3 months of 2011 as model time window since 4 heavy rain events characterized this period with flooding of the Ofanto River during two of them. The meteo-hydrological chain consists of: WRF-ARW model (Skamarock et al., 2008) for the atmospheric modeling, NOAH-MP Land Surface Model (Niu et al., 2011) which describes the vertical physics of the soil column up to 1m below the ground-level, and WRF-Hydro model (Gochis D., et al., 2013) which enables to model the lateral soil surface and subsurface water fluxes and is coupled in 1-way mode with WRF and 2way-mode with NOAH-MP. We have assessed which model tunable parameters, numerical choices and forcing data most impact the performance of our integrated modeling system and have determined an optimal set-up of our meteo-hydrological modeling chain that fully captures the observed heavy rain events and the related river floods. The skill was assessed with respect to available observations of precipitation and river runoff relying on more than 100 raingauge stations and 2 hydrological stations along the river network. The sensitivity results show positive impacts of higher resolution and upgraded land use categories, soil types and topography data on hindcast simulations. It is also found that the tunable parameters of soil infiltration, conductivity and

  5. The Aqueduct Global Flood Analyzer

    NASA Astrophysics Data System (ADS)

    Iceland, Charles

    2015-04-01

    As population growth and economic growth take place, and as climate change accelerates, many regions across the globe are finding themselves increasingly vulnerable to flooding. A recent OECD study of the exposure of the world's large port cities to coastal flooding found that 40 million people were exposed to a 1 in 100 year coastal flood event in 2005, and the total value of exposed assets was about US 3,000 billion, or 5% of global GDP. By the 2070s, those numbers were estimated to increase to 150 million people and US 35,000 billion, or roughly 9% of projected global GDP. Impoverished people in developing countries are particularly at risk because they often live in flood-prone areas and lack the resources to respond. WRI and its Dutch partners - Deltares, IVM-VU University Amsterdam, Utrecht University, and PBL Netherlands Environmental Assessment Agency - are in the initial stages of developing a robust set of river flood and coastal storm surge risk measures that show the extent of flooding under a variety of scenarios (both current and future), together with the projected human and economic impacts of these flood scenarios. These flood risk data and information will be accessible via an online, easy-to-use Aqueduct Global Flood Analyzer. We will also investigate the viability, benefits, and costs of a wide array of flood risk reduction measures that could be implemented in a variety of geographic and socio-economic settings. Together, the activities we propose have the potential for saving hundreds of thousands of lives and strengthening the resiliency and security of many millions more, especially those who are most vulnerable. Mr. Iceland will present Version 1.0 of the Aqueduct Global Flood Analyzer and provide a preview of additional elements of the Analyzer to be released in the coming years.

  6. Analysis of extraordinary flood events. U.S.-China bilateral symposium

    USGS Publications Warehouse

    Kirby, E.W.H.; Shi-Qian, Hua; Beard, L.R.

    1987-01-01

    The symposium took place in Nanjing on 15-19 October 1985 and this volume contains 29 of the 52 papers presented, most of the authors coming either from China or the USA. The articles are organized into three major topics: 1) detection of historical floods and evaluation of the uncertainties in their peak discharges and times of occurrence; 2) frequency analysis and design flood determination in the presence of extraordinary floods and historic floods; 3) use of storm data in determining design storms and design floods. -M.A.Bass

  7. Evaluation of an early warning system for glacial lake outburst flood (GLOF) events in Huaraz, Peru

    NASA Astrophysics Data System (ADS)

    McKinney, D. C.; Somos-Valenzuela, M. A.

    2014-12-01

    People in Cordillera Blanca range in Peru have a long history dealing with natural disasters associated to high mountains; particularly Glacier Lakes Outburst Flood (GLOF). Examples in the Cordillera Blanca vary from a GLOF that occurred in 1941 that killed more than 5000 people in the city of Huaraz to recent events from Lake Artison Baja in 2012 and Lake 513 on 2010, which were not devastating thanks to safety systems previously installed in those lakes. However, glaciers continue melting leaving new lakes or changing the characteristics of lakes that were previously controlled making safety systems obsolete that worked successfully in the past protecting communities downstream. Lake Palcacocha has evolved from being safe after the installation of a safety system in 1970 to an imminent source of GLOF risk due to the expansion that has occurred during the last 40 years increasing from a volume of 500,000 to 17 million m3. In response to this risk the community in Huaraz is planning an Early Warning System (EWS) that will allow the population to mobilize to a safe area in case a GLOF occurs. In this work we present an adaptation of the LifeSIM model to calculate the benefits from such an EWS using 2007 census data and a FLO-2D flood simulation model. The outputs are the number of people in Huaraz that could lose their life due to a GLOF. Our results indicate that without an EWS around 19,773 people could lose their life; whereas, if an EWS is installed the number of victims reduces to 7344. Finally, if mobilization of the affected population is improved the value reduces to 2865. The results show the importance of the EWS as well as informing and training the population to how to react if a GLOF occurs.

  8. Simulating a 40-year flood event climatology of Australia with a view to ocean-land teleconnections

    NASA Astrophysics Data System (ADS)

    Schumann, Guy J.-P.; Andreadis, Konstantinos; Stampoulis, Dimitrios; Bates, Paul

    2015-04-01

    We develop, for the first time, a proof-of-concept version for a high-resolution global flood inundation model to generate a flood inundation climatology of the past 40 years (1973-2012) for the entire Australian continent at a native 1 km resolution. The objectives of our study includes (1) deriving an inundation climatology for a continent (Australia) as a demonstrator case to understand the requirements for expanding globally; (2) developing a test bed to assess the potential and value of current and future satellite missions (GRACE, SMAP, ICESat-2, AMSR-2, Sentinels and SWOT) in flood monitoring; and (3) answering science questions such as the linking of inundation to ocean circulation teleconnections. We employ the LISFLOOD-FP hydrodynamic model to generate a flood inundation climatology. The model will be built from freely available SRTM-derived data (channel widths, bank heights and floodplain topography corrected for vegetation canopy using ICESat canopy heights). Lakes and reservoirs are represented and channel hydraulics are resolved using actual channel data with bathymetry inferred from hydraulic geometry. Simulations are run with gauged flows and floodplain inundation climatology are compared to observations from GRACE, flood maps from Landsat, SAR, and MODIS. Simulations have been completed for the entire Australian continent. Additionally, changes in flood inundation have been correlated with indices related to global ocean circulation, such as the El Niño Southern Oscillation index. We will produce data layers on flood event climatology and other derived (default) products from the proposed model including channel and floodplain depths, flow direction, velocity vectors, floodplain water volume, shoreline extent and flooded area. These data layers will be in the form of simple vector and raster formats. Since outputs will be large in size we propose to upload them onto Google Earth under the GEE API license.

  9. Colloquium: 100 years of mass spectrometry: Perspectives and future trends

    NASA Astrophysics Data System (ADS)

    Maher, Simon; Jjunju, Fred P. M.; Taylor, Stephen

    2015-01-01

    Mass spectrometry (MS) is widely regarded as the most sensitive and specific general purpose analytical technique. More than a century has passed for MS since the ground-breaking work of Nobel laureate Sir Joseph John Thomson in 1913. This Colloquium aims to (1) give an historical overview of the major instrumentation achievements that have driven mass spectrometry forward in the past century, including those leading up to the initial work of Thomson, (2) provide the nonspecialist with an introduction to MS, and (3) highlight some key applications of MS and explore the current and future trends. Because of the vastness of the subject area and quality of the manifold research efforts that have been undertaken over the last 100 years, which have contributed to the foundations and subsequent advances in mass spectrometry, it should be understood that not all of the key contributions may have been included in this Colloquium. Mass spectrometry has embraced a multitude of scientific disciplines and to recognize all of the achievements is an impossible task, such has been the diverse impact of this invaluable technique. Scientific progress is usually made via the cumulative effort of a large number of researchers; the achievements reported herein are only a representation of that effort.

  10. Pedernales oilfield, eastern Venezuela: The first 100 years

    SciTech Connect

    Gluyas, J.; Oliver, J.; Wilson, W.

    1996-08-01

    Petroleum seeps and surface tar mats attracted oil explorers to Pedernales in eastern Venezuela 100 years ago. Commercial production from the Pedernales Field was established by Creole in 1933. In three production periods, broken by WWII and the end of the Creole-Texaco refining contract, Creole and Lagoven produced about 60 MMSTB from about 60 wells in about 60 years. Peak production was in the late 1950s, when the field delivered 12,000 BOPD. Production was stopped in 1986. In March 1993, BP Venezuela acquired the license to reactivate Pedernales on behalf of Lagoven, and BP`s first well in the field was drilled in August 1994. A second was completed in early 1995. The production from each well was sufficiently encouraging for commerciality to be declared in March 1995. Phase 1 of the field reactivation demanded a production rate of 11,500 BOPD. As of now (September, 1995) six wells, including one gas disposal well, have been completed. Wells have been placed using a combination of old well data and mapping based on a close spaced 2D seismic survey shot in early 1994. Results from these first few wells indicate that the required production rate will be achieved despite severely depleted reservoir pressures. This paper tells the story of reactivation and re-evaluation of one of eastern Venezuela`s oldest oilfields.

  11. Slope restoration for a 100-year old canal

    SciTech Connect

    Skaggs, R.L.; Lewis, S.W.; Liebersbach, D.C.

    1995-12-31

    Turlock Irrigation District (TID) is located in the northern portion of the fertile San Joaquin Valley of California. TID`s primary water supply is conveyed from the 100-year-old LaGrange Diversion Dam via their historic Upper Main Canal. The original canal was constructed by excavating into slate bedrock for the uphill (cut) bank, and constructing unmortared rock walls and rock fill for the downhill (fill) embankment; the excavation was then lined with concrete. Soil fill raises of the downhill embankment over the last 30 years have reduced the slope stability to unacceptable levels in the steepest embankment areas. In March of 1994, two surficial slides prompted investigation of the long term embankment stability in the Warehouse Slide Area. Based on results of analysis for various stabilization scenarios, TID chose a stabilization method which included: (1) excavation of an access bench below the existing canal, (2) installation of steel pipe piles through the existing rock fill and into the bedrock, (3) construction of a mechanically stabilized earth (MSE) retaining wall and (4) construction of a soil-cement canal roadway pavement. The design was chosen by the owner because of cost competitiveness compared to other design alternatives and because the construction sequence allowed uninterrupted use of the canal. By using local river cobble for the MSE wall facing material, TID met the desired 50-year design life of the repair while maintaining the area`s historic visual features.

  12. Overuse syndrome in musicians--100 years ago. An historical review.

    PubMed

    Fry, H J

    Overuse syndrome in musicians was extensively reported 100 years ago. The clinical features and results of treatment, which were recorded in considerable detail, match well the condition that is described today. The medical literature that is reviewed here extends from 1830 to 1911 and includes 21 books and 54 articles from the English language literature, apart from two exceptions; however, the writers of the day themselves reviewed French, German and Italian literature on the subject. The disorder was said to result from the overuse of the affected parts. Two theories of aetiology, not necessarily mutually exclusive, were argued. The central theory regarded the lesion as being in the central nervous system, the peripheral theory implied a primary muscle disorder. No serious case was put forward for a psychogenic origin, though emotional factors were believed to aggravate the condition. Advances in musical instrument manufacture--particularly the development of the concert piano and the clarinet--may have played a part in the prevalence of overuse syndrome in musicians. Total rest from the mechanical use of the hand was the only effective treatment recorded. PMID:3540544

  13. A comparison of large 18th-century floods on Danube: Vienna - Bratislava - Budapest

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea; Parajka, Juraj

    2013-04-01

    The documentation of historic floods can help in better understanding of factors that might cause and contribute to large and extreme flood events. In particular, the analysis of historic floods provides information about flood seasonality, its changes and anthropogenic impacts on river flood regime which in some cases strongly influenced flood behaviour. The main objective of the present contribution is to document large and medium size flood events on Danube in Vienna, Bratislava and Budapest in the 18th century. In the present study, based on contemporary documentary evidence, for each of the three towns a five-scaled flood index series is developed to describe the magnitude and intensity of flood events. According to this classification, the 100-year flood event was characterised by the index value 5, while great destructive floods - depending on their extension, destructivity and further impacts - received the values 4 and 3, respectively. Less significant but still harmful flood events were classified as No. 2, and floods without further specification remained in the lowest category (No. 1). Beside classification issues, seasonality and flood frequency differences between the three towns are as well discussed. The results indicate that a greater number of flood events took place in the last decades of the century, but only a few flood events of the same magnitude are documented simultaneously in all three towns. And whereas in 1775 no winter flood event was reported in Vienna, an important ice jam flood was documented in Bratislava, and a catastrophic ice jam flood event, greatest of the century, occurred in Budapest. In 1787 autumn the greatest flood event of the century occurred in Vienna, while hardly any flood waves were observed at Budapest. While in Vienna, summer (and partly autumn) floods had great importance, in Budapest a large number of ice jam floods were documented. In some cases the differences are likely caused by different hydrometeorological

  14. Understanding the 2013 Boulder Flood: Assessing Extreme Precipitation Events and Future Climates in the Community Earth System Model (CESM)

    NASA Astrophysics Data System (ADS)

    Adams, R.; Neale, R. B.

    2014-12-01

    The Boulder flood of September 2013 resulted in significant structural damage, inundated communities, and accelerated land erosion in central and northern Colorado. This exceptional event led to approximately 11,000 people being evacuated in the area as more than 17 inches of rain fell in parts of Boulder County, Colorado in seven days. This storm resulted from persistent southerly flow and high precipitable water values which were responsible for the record-breaking precipitation. This study assessed the factors associated with extreme precipitation events in both observations and climate model simulations. Satellite-based observed precipitation from the Tropical Rainfall Measuring Mission, and ERA-Interim Reanalysis of precipitable water and low-level winds were used in this study. Probability distribution functions (PDFs) were calculated for daily values of observational and reanalysis variables: precipitation, precipitable water, and low-level winds. Each of the PDFs were compared with equivalent variables in the CESM simulations and analyzed over three regions of different areal extent occupying the eastern Rocky Mountains. The PDF calculations were found to be sensitive to the choice of the spatial region with fewer high precipitable water events in the northern domain and a greater number of high precipitable water events in the more southerly domain. The similarities between observational and present-day CESM PDFs enabled us to study changes to PDF distributions in future climate simulations. They predict a significant increase in precipitable water over the Boulder flood region. Given the importance of high precipitable water in the 2013 Boulder flood precipitation event, the potential for more frequent and stronger flooding events in the future is significant.

  15. Late Holocene environmental reconstructions and the implications on flood events, typhoon patterns, and agriculture activities in NE Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, L.-C.; Behling, H.; Lee, T.-Q.; Li, H.-C.; Huh, C.-A.; Shiau, L.-J.; Chang, Y.-P.

    2014-05-01

    In this study, we reconstructed the paleoenvironmental changes from a sediment archive of the floodplain lake in Ilan Plain of NE Taiwan on multi-decadal resolution for the last ca. 1900 years. On the basis of pollen and diatom records, we evaluated the record of past vegetation, floods, typhoons and agriculture activities of this area, which is sensitive to the hydrological conditions of the West Pacific. High sedimentation rates with low microfossil preservations reflected multiple flood events and humid climatic conditions during 100-1400 AD. A shortly interrupted dry phase can be found during 940-1010 AD. The driest phase corresponds to the Little Ice Age phase 1 (LIA1, 1400-1620 AD) with less disturbance by flood events, which enhanced the occurrence of wetlands (Cyperaceae) and diatom depositions. Humid phases with frequent typhoons are inferred by high percentages of Lagerstroemia and high ratios of planktonic/benthic diatoms, respectively, during 500-700 AD and Little Ice Age phase 2 (LIA2, 1630-1850 AD). The occurrences of cultivated Poaceae (Oryza) during 1250-1300 AD and the last ~400 years, reflect agriculture activities, which seems to implicate strongly with the environmental stability. Finally, we found flood events which dominated during the El Niño-like stage, but dry events as well as frequent typhoon events happened during the La Niña-like stage. After comparing our results with the reconstructed proxy for tropical hydrological conditions, we suggested that the local hydrology in coastal East Asia were strongly affected by the typhoon-triggered heavy rainfalls which were influenced by the variation of global temperature, expansion of the Pacific warm pool and intensification of ENSO events.

  16. Frequency of the 1993 flood in the upper Mississippi River Basin

    USGS Publications Warehouse

    Thomas, W.O., Jr.; Eash, D.A.

    1994-01-01

    The frequency of the 1993 flood in the upper Mississippi River Basin is characterized by applying Bulletin 17B and L-moment methods to 111 unregulated watersheds in the basin. The analysis indicated that the 1993 flood was primarily a 10- to 50-year event on unregulated watersheds less than about 50,000 square kilometers. Of the 111 stations analyzed, the L-moment and Bulletin 17B methods were used to identify 24 and 30 stations, respectively, that had recurrence intervals greater than 50 years, and 13 and 16 stations, respectively, that had recurrence intervals greater than 100 years for the 1993 flood. Because the magnitude and duration of precipitation was substantial over a major part of the basin, the 1993 flood was greater than a 100-year event on the larger watersheds such as the Missouri River downstream from Rulo, Nebraska, and a reach of the Mississippi River from Keokuk, Iowa, to St. Louis, Missouri.

  17. Floods in Kansas City, Missouri and Kansas, September 12-13, 1977

    USGS Publications Warehouse

    Hauth, Leland D.; Carswell, William J., Jr.

    1978-01-01

    The storm of September 12-13, 1977, produced as much as 16 inches of rainfall in the Kansas City, Missouri-Kansas area, left 25 persons dead, many homeless, and over 50 million dollars in damages. Flood hydrographs taken from U.S. Geological Survey gaging-stations reflected two storms occurring within 24 hours. Measured precipitation indicated each storm event to be near a 100-year, 24-hour rainfall frequency. Peak discharges determined at selected locations in areas of greater rainfall depths exceeded those of the 100-year floods. (Woodard-USGS)

  18. The Bosna River floods in May 2014

    NASA Astrophysics Data System (ADS)

    Vidmar, A.; Globevnik, L.; Koprivšek, M.; Sečnik, M.; Zabret, K.; Ðurović, B.; Anzeljc, D.; Kastelic, J.; Kobold, M.; Sušnik, M.; Borojevič, D.; Kupusović, T.; Kupusović, E.; Vihar, A.; Brilly, M.

    2015-10-01

    In May 2014, extreme floods occurred in the lower Sava River basin, causing major damage, with catastrophic consequences. Based on the data gathered, the weather situation in Bosnia and Herzegovina's (BiH) Bosna River basin was analysed and the hydrological conditions were provided, including the results of the probability analysis of the size of the recorded precipitation and flow rates. A hydrological model of the Bosna River basin was developed using HBV-light for the purposes of reconstructing and forecasting such events more effectively. All analyses confirmed that the May 2014 event was an extreme event whose returning period greatly exceeds 100 years.

  19. Chlorophyll a and phytoplankton in the Pomeranian Bay during and after the flood event

    NASA Astrophysics Data System (ADS)

    Gromisz, Sławomira; Zalewski, Mariusz; Ochocki, Stanisław; Kownacka, Janina M.

    1998-06-01

    Studies dealing with the impact of the flood event in the Odra River in July 1997 on the phytoplankton in the Pomeranian Bay were based on three cruises: in late July/early August, at the end of August, and in October 1997. During those studies, concentrations of chlorophyll a were measured. During the second cruise, the phytoplankton composition was investigated additionally. In August 1997, in the entire southern part of the Pomeranian Bay within a radius of about 30 km from the Swina mouth, chlorophyll concentrations were 3 4 times higher than in July 1996 and amounted to 5 15 mg/m3. Further offshore, concentrations were about 2 times higher (2 5 mg/m3) as compared to the 1996 values. At the beginning of August and in the first days of the second cruise, chlorophyll a concentrations were highest in the vicinity of the Swina mouth, reaching 15 25 mg/m3. They did not, however, differ much from the maximum values observed in July 1996. On 27 28 August 1997, a strong north-easterly wind caused open Bay waters to be transported towards the Swina outlet, leading to mixing of water masses and transport of phytoplankton with plume water towards the north-west. The chlorophyll concentrations measured on 19 29 October 1997 ranged from 2 9 mg/ m3 in the entire Bay and did not differ from those measured on 20 Sept. 3 Oct. 1993. A significant impact of the flood wave on phytoplankton composition in the Pomeranian Bay in August 1997 was not observed. Blue-green algae, blooms of which are typical of summer periods in the Baltic Sea, predominated in the entire area. Four potentially toxic species (Anabaena spiroides, Aphanizomenon flosaquae, Microcystis aeruginosa and Nodularia spumigena) appeared but did not occur in “bloom” quantities. The abundance of the dinoflagellate Prorocentrum minimum, which also is a potentially toxic species, was relatively high in the north-western part of the region studied, but this area is beyond the direct impact of estuarine waters. The

  20. Rain-on-snow events, floods and climate change in the Alps: Events may increase with warming up to 4°C and decrease thereafter.

    PubMed

    Beniston, Martin; Stoffel, Markus

    2016-11-15

    This paper focuses on the influence of mountain rain-on-snow (ROS) events that can on occasion trigger major floods in alpine catchments. In order to assess the evolution of these events in a recent past, and the potential changes that could be experienced in a changing climate over coming decades, we have focused on a small catchment in north-eastern Switzerland, the Sitter, well-endowed with both climate and hydrological data. Observations show that there has been an increase in the number of rain-on-snow events since the early 1960s related to the rise in atmospheric temperatures. Results from a simple temperature-based snow model show that the number of ROS events could increase by close to 50% with temperatures 2-4°C warmer than today, before declining when temperatures go beyond 4°C. The likelihood of more ROS events suggests that the risks of flooding in a future climate may indeed get worse before they improve. PMID:27476005

  1. Event-based washload transport and sedimentation in and around flood bypasses: Case study from the Sacramento Valley, California

    NASA Astrophysics Data System (ADS)

    Singer, M. B.; Aalto, R. A.

    2005-05-01

    In large river systems, suspended sediment transport and deposition patterns are often affected by channel constraints engineered for flood conveyance or navigation. Such managed channels typically have a limited number of overflow loci through which suspended sediment enters the river's floodplain. Engineered flood bypasses are narrow relic floodplains that are supplied by overflow diversion weirs along managed river channels, and support agriculture and complex aquatic and riparian habitats that are sensitive to the delivery of floods, fine sediment, and adsorbed contaminants. They function as wide, shallow conveyance channels parallel to the main river, and therefore present an opportunity to assess the applicability of existing theory for delivery to and settling of suspended sediment within floodplains. This study is an investigation of hydrograph characteristics, sediment delivery, and sedimentation within the upstream reaches of flood bypasses closest to the weir. We present analysis of hydrologic and sediment records and modeling in the Sacramento River basin. The effects of a single large flood in 1964-1965 were analyzed by documenting hydrograph characteristics, computing event-based sediment discharges and reach erosion/deposition through the bypass system, modeling bypass deposition, and comparing modeled results near the weirs with dated sediment cores. The rapidly rising, slowly declining 1964 flood was generated by storm runoff in the Sierra Nevada. The modeling results indicate: washload discharge through the lower valley 0.5 to 1.7 times long-term annual averages; mainstem reach erosion/deposition 0.5 to 1.25 times annual averages; and centimeter scale deposition in flood bypasses. The results are corroborated by a set of sediment cores extracted from Sacramento Valley bypasses, which were dated with 210Pb geochronology and analyzed for grain size. The modeling and data suggest net sediment accumulation between the channel and flood weirs and in

  2. Late Holocene environmental reconstructions and their implications on flood events, typhoon, and agricultural activities in NE Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, L.-C.; Behling, H.; Lee, T.-Q.; Li, H.-C.; Huh, C.-A.; Shiau, L.-J.; Chang, Y.-P.

    2014-10-01

    We reconstructed paleoenvironmental changes from a sediment archive of a lake in the floodplain of the Ilan Plain of NE Taiwan on multi-decadal resolution for the last ca. 1900 years. On the basis of pollen and diatom records, we evaluated past floods, typhoons, and agricultural activities in this area which are sensitive to the hydrological conditions in the western Pacific. Considering the high sedimentation rates with low microfossil preservations in our sedimentary record, multiple flood events were. identified during the period AD 100-1400. During the Little Ice Age phase 1 (LIA 1 - AD 1400-1620), the abundant occurrences of wetland plant (Cyperaceae) and diatom frustules imply less flood events under stable climate conditions in this period. Between AD 500 and 700 and the Little Ice Age phase 2 (LIA 2 - AD 1630-1850), the frequent typhoons were inferred by coarse sediments and planktonic diatoms, which represented more dynamical climate conditions than in the LIA 1. By comparing our results with the reconstructed changes in tropical hydrological conditions, we suggested that the local hydrology in NE Taiwan is strongly influenced by typhoon-triggered heavy rainfalls, which could be influenced by the variation of global temperature, the expansion of the Pacific warm pool, and the intensification of El Niño-Southern Oscillation (ENSO) events.

  3. Flood/drought event identification using an effective indicator based on the correlations between multiple time scales of the Standardized Precipitation Index and river discharge

    NASA Astrophysics Data System (ADS)

    Wang, Yuefeng; Chen, Xingwei; Chen, Ying; Liu, Meibing; Gao, Lu

    2015-12-01

    In order to further investigate the capability of the Standardized Precipitation Index (SPI) to identify flood/drought events, monthly precipitation data from 26 precipitation stations and monthly discharge data from four hydrological stations from 1960 to 2006 in the Minjiang River basin were used to analyze the correlations between multiple time scales of the SPI and river discharge. The SPI series that had a maximum correlation with discharge was chosen to detect flood/drought events in the basin, and the results were compared to historical flood/drought events. The results indicated the following. (1) High Pearson correlations between the SPI and discharge were identified at shorter time scales (1 to 3 months), and the maximum correlation was found on the time scale of 2 months. (2) Five floods among the six largest historical flood events in the Minjiang River basin were identified with the 2-month SPI, but the SPI does have shortcomings in identifying more general floods. The SPI also identified major drought events that were consistent with historical data. This demonstrates that the 2-month SPI is an effective indicator for the identification of major flood/drought events in the Minjiang River basin.

  4. 1.4 kyrs of flash flood events in the Southern European Alps: implications for extreme precipitation patterns and forcing over the north-western Mediterranean area

    NASA Astrophysics Data System (ADS)

    Wilhelm, B.; Arnaud, F.; Sabatier, P.; Crouzet, C.; Brisset, E.; Guiter, F.; Reyss, J. L.; Chaumillon, E.; Tachikawa, K.; Bard, E.; Delannoy, J. J.

    2012-04-01

    Extreme precipitation events trigger flash floods causing large human and economic losses. Their frequency and/or intensity are expected to increase in the context of global warming, especially in the Mediterranean region. However, the relationship between such events and past climate change remains difficult to assess. Indeed, the stochastic nature of extreme event occurrence precludes the identification of trends. This is reinforced by a lack in long-term instrumental data. It is hence essential to reconstruct long-term geological records of intense events to extend documented records beyond the observational data. This will enable a better understanding of local to regional flood hazard patterns in the context of global warming and hence improve predictive models. In the framework of Pygmalion research program, a multiproxy investigation of the Lake Allos (2230 m a.s.l., Southern French Alps) sediment sequence revealed the presence of 160 flood-triggered interbedded layers within a 1400-long sequence. Owing to sedimentary and geochemical characteristics and the frequent occurrence, such deposits were interpreted as the result of high-energy sediment inputs during intense torrential floods (i.e. flash-floods), related to extreme precipitation events. Furthermore the significant relationship between the thickness and the basal grain size of the graded beds allowed using the thickness as a proxy of the flood intensity. Trough the comparison with local historic flood reconstructions over the last 400 years, we argue that these flash floods were mostly triggered by autumnal meso-scale intense precipitation events. Since the Medieval Climate Anomaly (MCA), the absence of major change in erosion processes and local vegetation dynamics linked to anthropogenic impact led us to interpret the Allos flood record as the proxy for the occurrence of such extreme precipitation events over the last millennium. The frequency of Allos flash-flood events appeared consistent with

  5. 11-14 November 2012 Umbria Region (Central Italy) flood event: from prediction to management for civil protection purposes

    NASA Astrophysics Data System (ADS)

    Berni, Nicola; Pandolfo, Claudia; Stelluti, Marco; Zauri, Renato; Ponziani, Francesco; Francioni, Marco; Governatori Leonardi, Federico; Formica, Alessandro; Natazzi, Loredana; Costantini, Sandro

    2013-04-01

    Following laws and regulations concerning extreme natural events management, the Italian national hydrometeorological early warning system is composed by 21 regional offices (Functional Centres - CF). Umbria Region CF is located in Central Italy and provides early warning, monitoring and decision support systems (DSS) when significant flood/landslide events occur. The alert system is based on hydrometric and rainfall thresholds with detailed procedures for the management of critical events in which different roles of authorities and institutions involved are defined. For the real time flood forecasting system, at the CF several operational hydrological and hydraulic models were developed and implemented for a "dynamic" hazard/risk scenario assessment for Civil Protection DSS, useful also for the development of Flood Risk Management Plans according to the European "Floods Directive" 2007/60. In the period 11th-14th November 2012, a significant flood event occurred in Umbria (as well as Tuscany and northern Lazio). The territory was interested by intense and persistent rainfall; the hydro-meteorological monitoring network recorded locally rainfall depth over 300 mm in 72 hours and, generally, values greater than the seasonal averages all over the region. In the most affected area the recorded rainfall depths correspond to centenarian return period: one-third of the annual mean precipitation occurred in 2-3 days. Almost all rivers in Umbria have been involved, exceeding hydrometric thresholds, and several ones overflowed. Furthermore, in some cases, so high water levels have never been recorded by the hydrometric network. As in the major flood events occurred in the last years, dams (Montedoglio and Corbara dams along Tiber River and Casanuova dam along Chiascio River) and other hydraulic works for flood defense (e.g. along Chiani stream) played a very important mitigation role, storing high water volumes and avoiding the overlap of peak discharges downstream. During

  6. The Kankakee Torrent and other large meltwater flooding events during the last deglaciation, Illinois, USA

    NASA Astrophysics Data System (ADS)

    Curry, B. Brandon; Hajic, Edwin R.; Clark, James A.; Befus, Kevin M.; Carrell, Jennifer E.; Brown, Steven E.

    2014-04-01

    Evidence of the Kankakee Torrent (Ekblaw and Athy, 1925) includes boulder bars formed on a scoured bedrock surface west of Kankakee, Illinois, and overflow channels that connect several moraine-dammed basins (Wauponsee, Watseka, and Pontiac; Willman and Payne, 1942). Geomorphic evidence of a large scale flood event in the Illinois Valley includes features such as erosional residuals (Hajic, 1990). The age of the Kankakee Torrent is about 19,000 cal yr BP based on the pooled mean of four radiocarbon ages of tundra plant stems and leaves from the Oswego channel complex (median probability = 18,930 cal yr BP, σ1 range, 18,870-18,970 cal yr BP). Analysis of recently obtained sediment cores from the middle Illinois River valley near Havana, Illinois, has revealed the bedrock surface is defended by a mantle of bouldery debris buried by 15 m of mostly slackwater lake sediment. Radiocarbon ages of needles archived in the lake sediment reveal evidence for an early lake phase that post-dates the Kankakee Torrent (18,030-17,530 cal yr BP) and a later lake phase (15,690-13,040 cal yr BP). The radiocarbon ages indicate that the deeply buried bouldery rubble was deposited by the Kankakee Torrent. Consideration of isostasy indicates that the earlier lake phase at Havana may have been associated with downward flexure of land surface in response to glacier loading. The younger lake phase was caused in part by deposition of a sediment dam (the Savanna-Deer Plain terrace) at the mouth of the Illinois River. The lake shoaled due to passing of the isostatic forebulge across the area.

  7. -field data exploitation: drought and floods events analysis using the MEA platform

    NASA Astrophysics Data System (ADS)

    Natali, Stefano; Scremin, Alessandro; Mantovani, Simone; Folegani, Marco

    2014-05-01

    Since the launch of the first artificial satellite with the scope of observing the Earth - Atmosphere system, the amount of data retrieved from space platform has grown continuously: nowadays Earth Observation data collected from space platforms provide Gigabyte of data per year, and cover all the geophysics fields. Nevertheless, most of the scientific and application communities (land, ocean, atmosphere, hydrology, vegetation and so on) have worked separately (or with just few contacts) for tenths of years, developing sensors, algorithms, data formats, and datasets (Petabytes of data) in an almost-independent way. The need of jointly use data coming from the different communities and from different data sources (such as EO products and on-ground data) to allow multi-disciplinary studies has been recognized by the European Space Agency since 2008: the Multi-sensor Evolution Analysis (MEA) platform (https://mea.eo.esa.int/) has been developed with the scope of demonstrating the feasibility of an advanced tool for long term multi-field / multi-resolution / multi-temporal data management system, and has been used by the FP7 Project EarthServer to exploit long time series of EO and on-ground retrieved climate data. MEA is now available for multi-temporal and multi-field data visualization and exploitation, containing tenths of Terabytes of data from the land and atmosphere domains (https://mea.eo.esa.int/data_availability.html) allowing users integrating the modeling approach with an intensive data exploitation approach. In the present work, the usability of the MEA platform is described, and some use cases to demonstrate the combined use of atmospheric (precipitation), vegetation (NDVI) and soil (soil moisture) data are provided for drought and flooding events.

  8. Use of satellite images to determine surface-water cover during the flood event of September 13, 2013, in Lyons and western Longmont, Colorado

    USGS Publications Warehouse

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

    2015-01-01

    This surface-water cover dataset was created as a timely representation of post-flood ground conditions to support response efforts. This dataset and all processed imagery and derived products were uploaded to the USGS Hazards Data Distribution System (HDDS) website (http://hddsexplorer.usgs.gov/uplift/hdds/) for distribution to those responding to the flood event.

  9. Climate Extremes and Adaptive Flood Management in the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Munevar, A.; Das, T.

    2014-12-01

    Current evaluations of Central Valley, California flood control improvements are based on climate and hydrologic conditions that occurred over the past 100 years. This historical period includes significant flood events caused by intense precipitation, rapid snowmelt, and watershed conditions that, in combination, result in the hydrologic conditions that have shaped the current flood infrastructure and management. Future climate projections indicate the potential for increased flood peak flows and flood volumes in the Central Valley that will likely exceed the current capacity of existing flood control systems. Preliminary estimates of potential changes in flood flows have been developed for all the major watersheds in the Central Valley through the use of regionally downscaled climate projections and hydrologic modeling. Results suggest increasing flood risks that are dependent on spatial climate change patterns, individual watershed characteristics, and existing infrastructure investments. In many areas, the increasing flood risks cannot be managed through traditional flood infrastructure alone, and more adaptive measures are needed to improve resilience under climate extremes. Planning approaches are being applied to consider the full range of flood risks, and include tiered interventions for events beyond the floods-of-record. The on-going flood risk planning efforts demonstrate new, and sensible approaches toward improving resilience for uncertain and evolving climate extremes.

  10. Optimization of hydrological parameters of a distributed runoff model based on multiple flood events

    NASA Astrophysics Data System (ADS)

    Miyamoto, Mamoru; Matsumoto, Kazuhiro; Tsuda, Morimasa; Yamakage, Yuzuru; Iwami, Yoichi; Anai, Hirokazu

    2015-04-01

    The error sources of flood forecasting by a runoff model commonly include input data, model structures, and parameter settings. This study focused on a calibration procedure to minimize errors due to parameter settings. Although many studies have been done on hydrological parameter optimization, they are mostly about individual optimization cases applying a specific optimization technique to a specific flood. Consequently, it is difficult to determine the most appropriate parameter set to make forecasts on future floods, because optimized parameter sets vary by flood type. Thus, this study aimed to develop a comprehensive method for optimizing hydrological parameters of a distributed runoff model for future flood forecasting. A distributed runoff model, PWRI-DHM, was applied to the Gokase River basin of 1,820km2 in Japan in this study. The model with gridded two-layer tanks for the entire target river basin includes hydrological parameters, such as hydraulic conductivity, surface roughness and runoff coefficient, which are set according to land-use and soil-type distributions. Global data sets, e.g., Global Map and DSMW (Digital Soil Map of the World), were employed as input data such as elevation, land use and soil type. Thirteen optimization algorithms such as GA, PSO and DEA were carefully selected from seventy-four open-source algorithms available for public use. These algorithms were used with three error assessment functions to calibrate the parameters of the model to each of fifteen past floods in the predetermined search range. Fifteen optimized parameter sets corresponding to the fifteen past floods were determined by selecting the best sets from the calibration results in terms of reproducible accuracy. This process helped eliminate bias due to type of optimization algorithms. Although the calibration results of each parameter were widely distributed in the search range, statistical significance was found in comparisons between the optimized parameters

  11. 100 years after the Marsica earthquake: contribute of outreach activities

    NASA Astrophysics Data System (ADS)

    D'Addezio, Giuliana; Giordani, Azzurra; Valle, Veronica; Riposati, Daniela

    2015-04-01

    Many outreach events have been proposed by the scientific community to celebrate the Centenary of the January 13, 1915 earthquake, that devastated the Marsica territory, located in Central Apennines. The Laboratorio Divulgazione Scientifica e Attività Museali of the Istituto Nazionale di Geofisica e Vulcanologia (INGV's Laboratory for Outreach and Museum Activities) in Rome, has realised an interactive exhibition in the Castello Piccolomini, Celano (AQ), to retrace the many aspects of the earthquake disaster, in a region such as Abruzzo affected by several destructive earthquakes during its history. The initiatives represent an ideal opportunity for the development of new programs of communication and training on seismic risk and to spread the culture of prevention. The INGV is accredited with the Servizio Civile Nazionale (National Civic Service) and volunteers are involved in the project "Science and Outreach: a comprehensive approach to the divulgation of knowledge of Earth Sciences" starting in 2014. In this contest, volunteers had the opportunity to fully contribute to the exhibition, in particular, promoting and realising two panels concerning the social and environmental consequences of the Marsica earthquake. Describing the serious consequences of the earthquake, we may raise awareness about natural hazards and about the only effective action for earthquake defense: building with anti seismic criteria. After studies and researches conducted in libraries and via web, two themes have been developped: the serious problem of orphans and the difficult reconstruction. Heavy snowfalls and the presence of wolves coming from the high and wild surrounding mountains complicated the scenario and decelerated the rescue of the affected populations. It is important to underline that the earthquake was not the only devastating event in the country in 1915; another drammatic event was, in fact, the First World War. Whole families died and the still alive infants and

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

    NASA Astrophysics Data System (ADS)

    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

  13. Impact of temporal resolution of inputs on hydrological model performance: An analysis based on 2400 flood events

    NASA Astrophysics Data System (ADS)

    Ficchì, Andrea; Perrin, Charles; Andréassian, Vazken

    2016-07-01

    Hydro-climatic data at short time steps are considered essential to model the rainfall-runoff relationship, especially for short-duration hydrological events, typically flash floods. Also, using fine time step information may be beneficial when using or analysing model outputs at larger aggregated time scales. However, the actual gain in prediction efficiency using short time-step data is not well understood or quantified. In this paper, we investigate the extent to which the performance of hydrological modelling is improved by short time-step data, using a large set of 240 French catchments, for which 2400 flood events were selected. Six-minute rain gauge data were available and the GR4 rainfall-runoff model was run with precipitation inputs at eight different time steps ranging from 6 min to 1 day. Then model outputs were aggregated at seven different reference time scales ranging from sub-hourly to daily for a comparative evaluation of simulations at different target time steps. Three classes of model performance behaviour were found for the 240 test catchments: (i) significant improvement of performance with shorter time steps; (ii) performance insensitivity to the modelling time step; (iii) performance degradation as the time step becomes shorter. The differences between these groups were analysed based on a number of catchment and event characteristics. A statistical test highlighted the most influential explanatory variables for model performance evolution at different time steps, including flow auto-correlation, flood and storm duration, flood hydrograph peakedness, rainfall-runoff lag time and precipitation temporal variability.

  14. 100 Years of the Quantum - the Glory and the Shame

    NASA Astrophysics Data System (ADS)

    Wheeler, John Archibald

    2001-03-01

    What is the greatest mystery that stands out on the books of physics today? Every one of us will have a different answer. Some will say it is the structure of the elementary particles. Others ask in what form is the mass or the attraction that has held the universe together thus far against perpetual expansion. Others will think of the November 11, 1999 dedication of America's first 6 kilometer by 6 kilometer gravity wave detector and will ask what information it will bring us about events going on in the deep and secret places of the universe. My own hope is that we'll see in time to come the answer to a question now almost a century old, "How come the quantum?" Gregory Breit would have sympathized with the investigations at each of these fronts, and could surely have filled us in on what the pioneers thought and said about the question, "How come the quantum?" ...

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

    NASA Technical Reports Server (NTRS)

    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.

  16. [The 20th century: 100 years of misfortune and splendor].

    PubMed

    Urdaneta-Carruyo, Eliéxer

    2005-01-01

    The 20th century has been one of the most intense and convulsive periods in the History of humanity. A century of paradoxes and contrasts, it began with optimism, it witnessed the apocalypse of two world wars, and finished with unimaginable scientific progress that gave us a new civilization that we cannot yet grasp. In this century, significant events happened that shaped our time and projected their results toward an immediate future. Some of these were providential in understanding man's life, fighting against illnesses and prolonging life, and others were of undeniable social importance for humanity. Some knowledge was based on the work of others. Philosophy was embedded in mathematics, as was science in philosophy, while politics and the economy exercised so decisive an influence in our way of feeling and living that culture and society were affected to the core. Within that century the biggest technological revolution of all the time was also created, as transcendent as it was unimaginable, which put mankind on the road to the stars with the moon landing and in the process created the information society whose signature symbol, the internet, emerged as a new demiurge. However, the 20th century, with all its misfortune and splendor, paradoxes and contrasts, creation and destruction, was the most transcendent in the whole of history and it bequeaths to the future a promising horizon in the search for a renovated meaning of life and a yearning for peaceful coexistence for the whole humanity. PMID:15754756

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

    SciTech Connect

    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

  18. Flooding scenarios, hazard mapping and damages estimation: what if the 2011 Cinque Terre event had happened in Genoa?

    NASA Astrophysics Data System (ADS)

    Silvestro, Francesco; Rebora, Nicola; Rossi, Lauro; Dolia, Daniele; Gabellani, Simone; Pignone, Flavio; Masciulli, Cristiano

    2016-04-01

    During the autumn of 2011 two catastrophic very intense rainfall events affected two different parts of the Liguria Region of Italy causing various flash floods, the first occurred in October and the second at the beginning of November. Various studies demonstrated that the two events had a similar genesis and similar triggering elements. In this work we did the exercise of putting the rainfall field of the first event (Cinque Terre area) on the main catchment, stroke by the second event, that has its mouth in correspondence of the biggest city of the Liguria Region: Genoa. A flood forecast framework and a hydraulic model were used as tools to quantitatively carry out a "what if" experiment, a proper methodology for damages estimation is then used to estimate the potential losses and the people affected. The results are interesting, surprising and in such a way worrying: a peak flow with return period larger than 200 years would have occurred with an estimated damage between 120 and 220 million of euros for the city of Genoa, Italy.

  19. Temporal changes in allele frequencies in a small marble trout Salmo marmoratus population threatened by extreme flood events.

    PubMed

    Pujolar, J M; Vincenzi, S; Zane, L; Crivelli, A J

    2016-03-01

    The effect of extreme floods on the genetic composition of marble trout Salmo marmoratus living in Lipovscek, a tributary of the Soca River in Slovenia, which has been affected by multiple destructive flood events for centuries was investigated. By monitoring genetic variability during the period 2004-2011, apparent signatures of genetic erosion including a decline in observed and expected heterozygosities and allelic richness were observed. Contemporary effective population size was estimated between 11 and 55 individuals, which is congruent with census data. The data suggest asymmetric gene flow between the two sections of the river. The existence of substantial downstream migration (15-19%) was confirmed by paternity analysis. A small (1-3%) upstream migration was also suggested, which was confirmed by tagging data. Overall, low genetic diversity has not prevented the survival of the Lipovscek population, which might be a common feature of salmonid freshwater populations. PMID:26832308

  20. Combined Effect of an Atmospheric River and a Cut-off Low in Hiroshima Flooding Event on August 19, 2014

    NASA Astrophysics Data System (ADS)

    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.

  1. 100 Years of British military neurosurgery: on the shoulders of giants.

    PubMed

    Roberts, S A G

    2015-01-01

    Death from head injuries has been a feature of conflicts throughout the world for centuries. The burden of mortality has been variously affected by the evolution in weaponry from war-hammers to explosive ordnance, the influence of armour on survivability and the changing likelihood of infection as a complicating factor. Surgery evolved from haphazard trephination to valiant, yet disjointed, neurosurgery by a variety of great historical surgeons until the Crimean War of 1853-1856. However, it was events initiated by the Great War of 1914-1918 that not only marked the development of modern neurosurgical techniques, but our approach to military surgery as a whole. Here the author describes how 100 years of conflict and the input and intertwining relationships between the 20th century's great neurosurgeons established neurosurgery in the United Kingdom and beyond. PMID:26292388

  2. Re-assessing the flood risk in Scotland.

    PubMed

    Black, Andrew R; Burns, John C

    2002-07-22

    This paper presents a review of changes in flood risk estimation on Scottish rivers resulting from re-analysis of flood records or from the application of new methods. The review arises at a time when flood damages have received recent prominence through the occurrence of a number of extreme floods in Scotland, and when the possible impacts of climate change on flood risk are receiving considerable attention. An analysis of the nine longest available peaks-over-threshold (POT) flood series for Scottish rivers reveals that, for thresholds yielding two events per year on average, annual POT frequencies on western rivers have increased in the 1980s/1990s to maximum recorded values, while in the east, values were highest in the 1950s/1960s. These results support the results of flood modelling work based on rainfall and temperature records from the 1870s, which indicate that, in western catchments, annual POT frequencies in the 1980s/1990s are unprecedented. No general trends in flood magnitude series were found, but an unexpected cluster of extreme floods is identified as having occurred since 1988, resulting in eight of Scotland's 16 largest gauged rivers producing their maximum recorded flows since then. These shifts are related to recent increases in the dominance of westerly airflows, share similarities with the results of climate change modelling, and collectively point to increases in flood risk in many parts of Scotland. The paper also reviews advances in flood risk estimation arising from the publication of the UK Flood Estimation Handbook, developments in the collection and use of historic flood estimation and the production of maps of 100-year flood areal extent. Finally the challenges in flood risk estimation posed by climate change are examined, particularly in relation to the assumption of stationarity. PMID:12169005

  3. Low-probability flood risk modeling for New York City.

    PubMed

    Aerts, Jeroen C J H; Lin, Ning; Botzen, Wouter; Emanuel, Kerry; de Moel, Hans

    2013-05-01

    The devastating impact by Hurricane Sandy (2012) again showed New York City (NYC) is one of the most vulnerable cities to coastal flooding around the globe. The low-lying areas in NYC can be flooded by nor'easter storms and North Atlantic hurricanes. The few studies that have estimated potential flood damage for NYC base their damage estimates on only a single, or a few, possible flood events. The objective of this study is to assess the full distribution of hurricane flood risk in NYC. This is done by calculating potential flood damage with a flood damage model that uses many possible storms and surge heights as input. These storms are representative for the low-probability/high-impact flood hazard faced by the city. Exceedance probability-loss curves are constructed under different assumptions about the severity of flood damage. The estimated flood damage to buildings for NYC is between US$59 and 129 millions/year. The damage caused by a 1/100-year storm surge is within a range of US$2 bn-5 bn, while this is between US$5 bn and 11 bn for a 1/500-year storm surge. An analysis of flood risk in each of the five boroughs of NYC finds that Brooklyn and Queens are the most vulnerable to flooding. This study examines several uncertainties in the various steps of the risk analysis, which resulted in variations in flood damage estimations. These uncertainties include: the interpolation of flood depths; the use of different flood damage curves; and the influence of the spectra of characteristics of the simulated hurricanes. PMID:23383711

  4. Juventae Chasma and Maja Valles, Mars: Further Evidence for Multiple Flooding Events

    NASA Astrophysics Data System (ADS)

    Gross, C.; Wendt, L.; Dumke, A.; Neukum, G.

    2009-04-01

    -image mosaic with a ground resolution of 12.5 m per pixel. The main processing tasks for the DTM derivation are first a pre-rectification of image data using the global MOLA- based DTM, then a least-squares area-based matching between nadir and the other channels (stereo and photometry) in a pyramidal approach and finally, DTM raster generation. Improved orientation data are necessary for high-resolution digital terrain models and orthoimage mosaics. For this purpose, new exterior and interior orientation data, based on tie-point matching have been used. The bundle adjustment approach for photogrammetric point determination with a three-line camera is a least squares adjustment based on the well known collinearity equations [6]. The construction of the HRSC-DTM is the basis for further investigation of the masses and volumes, transported from Juventae Chasma through Maja Valles. We use HRSC and OMEGA (Mars Express), as well as HiRise and CRISM (Mars Reconnaissance Orbiter) data for generally mapping the target area. Crater counting is carried out using CTX and HRSC images. Results: The results of the first determinations of the impact crater size-frequency distributions are presented in Fig. 2 and 3 and show an age of 1.22 Ga (+/- 0.16 Ga) for the western part of the Maja Valles channel. The southeastern channel (close to the streamlined island) shows older ages of 3.68 Ga (+0.08/-0.17 Ga) and 2.18 Ga (+/- 0.31 Ga). This clearly indicates, that multiple flooding events took place in the area. The first results for Juventae Chasma age determinations indicate an age of 3.33 Ga. Conclusions: The HRSC-DTM enables us to examine the study area most accurately. We dated the formation of the Juventae Chasma with an age of at least 3.33 Ga. The investigated sites at Maja Valles clearly show evidences for multiple outflow events. Some of these events took place before the formation of the sulfate deposits in Juventae Chasma. Further age determinations and mapping will be carried out in

  5. Stochastic generation of flood events to extend observed hydrological series by combining a copula model with hydrometeorological modelling

    NASA Astrophysics Data System (ADS)

    Requena, Ana; Flores, Isabel; Mediero, Luis; Garrote, Luis

    2013-04-01

    A multivariate flood frequency analysis is required for designing some structures like dams. Multivariate copula models are usually used to obtain joint return periods of the flood variables. There exist several families of copulas and a selection procedure is required to find the copula that best fits the observations. Moreover, observed hydrological series are usually short and the fit of the right tail of the copula remains highly uncertain. In this work, a procedure to extend short observed series is proposed by the use of both hydrometeorological modelling and a copula model to generate synthetic hydrographs. The procedure takes synthetic rainstorms events generated by the RainSim software as input. The RIBS rainfall-runoff model is used to simulate the hydrological processes in the basin. The procedure was tested in the Santillana reservoir in Spain, were both RainSim and RIBS models were calibrated prior to this study. A sensitivity analysis was conducted in order to find the minimum synthetic length that makes the copula selection process robust enough. As computational time of hydrometeorological modelling is not negligible, the extended record from modelling results could be re-extended by the fitted copula, reducing the computation time. This final extended hydrological series can be used to improve flood risk assessment studies. Key words: Stochastic generation, copulas, rainfall-runoff modelling Session: HS7.15 - Hydroclimatic stochastics Convener: S. Grimaldi Co-Conveners: A. A. Carsteanu, D. Koutsoyiannis, X. L. Wang and S. M. Papalexiou

  6. The 2010 explosive eruption of Java's Merapi volcano—A '100-year' event

    NASA Astrophysics Data System (ADS)

    Surono; Jousset, Philippe; Pallister, John; Boichu, Marie; Buongiorno, M. Fabrizia; Budisantoso, Agus; Costa, Fidel; Andreastuti, Supriyati; Prata, Fred; Schneider, David; Clarisse, Lieven; Humaida, Hanik; Sumarti, Sri; Bignami, Christian; Griswold, Julie; Carn, Simon; Oppenheimer, Clive; Lavigne, Franck

    2012-10-01

    Merapi volcano (Indonesia) is one of the most active and hazardous volcanoes in the world. It is known for frequent small to moderate eruptions, pyroclastic flows produced by lava dome collapse, and the large population settled on and around the flanks of the volcano that is at risk. Its usual behavior for the last decades abruptly changed in late October and early November 2010, when the volcano produced its largest and most explosive eruptions in more than a century, displacing at least a third of a million people, and claiming nearly 400 lives. Despite the challenges involved in forecasting this 'hundred year eruption', we show that the magnitude of precursory signals (seismicity, ground deformation, gas emissions) was proportional to the large size and intensity of the eruption. In addition and for the first time, near-real-time satellite radar imagery played an equal role with seismic, geodetic, and gas observations in monitoring eruptive activity during a major volcanic crisis. The Indonesian Center of Volcanology and Geological Hazard Mitigation (CVGHM) issued timely forecasts of the magnitude of the eruption phases, saving 10,000-20,000 lives. In addition to reporting on aspects of the crisis management, we report the first synthesis of scientific observations of the eruption. Our monitoring and petrologic data show that the 2010 eruption was fed by rapid ascent of magma from depths ranging from 5 to 30 km. Magma reached the surface with variable gas content resulting in alternating explosive and rapid effusive eruptions, and released a total of ~ 0.44 Tg of SO2. The eruptive behavior seems also related to the seismicity along a tectonic fault more than 40 km from the volcano, highlighting both the complex stress pattern of the Merapi region of Java and the role of magmatic pressurization in activating regional faults. We suggest a dynamic triggering of the main explosions on 3 and 4 November by the passing seismic waves generated by regional earthquakes on these days.

  7. Reassessing flood frequency for the Sussex Ouse, Lewes: the inclusion of historical flood information since AD 1650

    NASA Astrophysics Data System (ADS)

    Macdonald, N.; Kjeldsen, T. R.; Prosdocimi, I.; Sangster, H.

    2014-10-01

    The application of historical flood information as a tool for augmenting instrumental flood data is increasingly recognised as a valuable tool. Most previous studies have focused on large catchments with historic settlements, this paper applies the approach to the smaller lowland system of the Sussex Ouse in southeast England. The reassessment of flood risk on the Sussex Ouse is pertinent in light of the severe flooding in October 2000 and heightened concerns of a perceived increase in flooding nationally. Systematic flood level readings from 1960 and accounts detailing past flood events within the catchment are compiled back to ca. 1750. This extended flood record provides an opportunity to reassess estimates of flood frequency over a timescale not normally possible within flood frequency analysis. This paper re-evaluates flood frequency at Lewes on the Sussex Ouse downstream of the confluence of the Sussex Ouse and River Uck. The paper considers the strengths and weaknesses in estimates resulting from contrasting methods of analysis and their corresponding data: (i) single site analysis of gauged annual maxima; (ii) combined analysis of systematic annual maxima augmented with historical peaks of estimated magnitude; (iii) combined analysis of systematic annual maxima augmented with historical peaks of estimated magnitude exceeding a known threshold, and (iv) sensitivity analysis including only the very largest historical flood events. Use of the historical information was found to yield much tighter confidence intervals of risk estimates, with uncertainty reduced by up to 40% for the 100-year return frequency event when historical information was added to the gauged data.

  8. Flood Hazard Mapping Assessment for Lebanon

    NASA Astrophysics Data System (ADS)

    Abdallah, Chadi; Darwich, Talal; Hamze, Mouin; Zaarour, Nathalie

    2014-05-01

    recurrence flood plain maps of 10, 50 & 100 years intensity maps along with flood hazard maps for each watershed. It is of utmost significance for this study to be effective that the produced flood intensity and hazard maps will be made available to decision-makers, planners and relevant community stakeholders.

  9. The 2014 coral bleaching and freshwater flood events in Kāne'ohe Bay, Hawai'i.

    PubMed

    Bahr, Keisha D; Jokiel, Paul L; Rodgers, Kuʻulei S

    2015-01-01

    Until recently, subtropical Hawai'i 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 Hawai'i will occur with increasing frequency and increasing severity over future decades. A freshwater "kill" event occurred during July 2014 in the northern part of Kāne'ohe 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" actually started long before the

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Do hurricanes leave unique sedimentological records in floodplain settings? Connecticut River, Tropical Storm Irene and past flood events

    NASA Astrophysics Data System (ADS)

    Yellen, B.; Woodruff, J. D.; Kratz, L. N.; Fallon, A.

    2012-12-01

    In late August, 2011, Tropical Storm Irene passed directly over the Connecticut River watershed causing several low order streams to swell beyond prior historical maximum discharges. Although resultant discharge on the mainstem Connecticut River only amounted to a one in seven year-sized event, its sediment load far exceeded the historical discharge to sediment concentration relationship. Gravity cores taken in off-channel ponds following the hydrograph peak clearly showed deposition of storm-mobilized grains. Samples collected from floodplain forest locations also showed significant accumulation. In both depositional settings, grainsize, lithology and percent organics of flood event deposition differed dramatically from background sedimentation. Long cores collected from these same settings suggest that similar deposits from historical storms of record from the past three centuries are preserved in the floodplain sediment record.; Landsat 5 true color image collected on September 2, 2011 - two days after Tropical Storm Irene left the region.

  12. Predictability of prototype flash flood events in the Western Mediterranean under uncertainties of the precursor upper-level disturbance

    NASA Astrophysics Data System (ADS)

    Romero, R.; Martín, A.; Homar, V.; Alonso, S.; Ramis, C.

    2006-01-01

    The HYDROPTIMET case studies 9-10/06/2000 Catalogne, 8-9/09/2002 Cévennes and 24-26/11/2002 Piémont encompass prototype flash-flood situations in the western Mediterranean, attending to the relevant synoptic and mesoscale signatures identified on the meteorological charts. A prominent mid-tropospheric trough or cut-off low can be identified in all events prior and during the period of heavy rains, which clearly served as the precursor agent for the onset of the flash-flood conditions and the cyclogenesis at low levels. Being aware of the uncertainty in the representation of the upper-level disturbance and the necessity to cope with it within the operational context when attempting to issue short to mid-range numerical weather predictions of these high impact weather events, a systematic exploration of the predictability of the three selected case studies, subject to uncertainties in the representation of the upper-level precursor disturbance, is carried out in this paper by means of numerical simulations.

  13. Water chemistry and ecotoxicity of an acid mine drainage-affected stream in subtropical China during a major flood event.

    PubMed

    Lin, C; Wu, Y; Lu, W; Chen, A; Liu, Y

    2007-04-01

    Field and laboratory work was carried out to investigate the chemistry and ecotoxicity of stream water affected by acid mine drainage in a tributary catchment of the Pearl River in subtropical China during a major flood that corresponded to a return period of 100 years. The results indicate that stream water was affected by acid mine drainage from the Dabaoshan mine at least to a distance of 25 km downstream of the mine water discharge point. It appears that H(+) generated from sulfide oxidation in the waste rock dumps was readily available for exporting. The amount of H(+) being discharged into the receiving stream depended on the volume of out-flowing waters. However, there was a lag time for the discharges of the metals. This may be attributed to the slower release of metals, relative to H(+), because it might take more time for the dissolution of heavy metal-bearing compounds, particularly the sparsely soluble jarosites. Fe, Zn and Al were the major metals of potential toxicity contained in the AMD-affected stream water, followed by Mn, Cu, Pb, As, Cd and Ni. The concentrations of these metals in the water decreased rapidly down the stream. This corresponds with an increase in the concentrations of reactive heavy metal fractions in benthic mud down the stream, reflecting the precipitation of heavy metal compounds with increasing pH and their subsequent deposition in the streambed. Toxicity tests show that the AMD-affected stream water at 3.5 km downstream of the discharge point was highly toxic to the test organism. At 25 km downstream of the discharge point where stream water pH was as high as 5.75, marked toxic responses of the test organism were still observed. PMID:16979817

  14. Channel Geometry and Flood Flows: Quantifying over-bank flow dynamics during high-flow events in North Carolina's floodplains

    NASA Astrophysics Data System (ADS)

    Lovette, J. P.; Duncan, J. M.; Vimal, S.; Band, L. E.

    2015-12-01

    Natural riparian areas play numerous roles in the maintenance and improvement of stream water quality. Both restoration of riparian areas and improvement of hydrologic connectivity to the stream are often key goals of river restoration projects. These management actions are designed to improve nutrient removal by slowing and treating overland flow delivered from uplands and by storing, treating, and slowly releasing streamwater from overbank inundation during flood events. A major question is how effective this storage of overbank flow is at treating streamwater based on the cumulative time stream discharge at a downstream location has spent in shallower, slower overbank flow. The North Carolina Floodplain Mapping Program maintains a detailed statewide Flood Risk Information System (FRIS) using HEC-RAS modeling, lidar, and detailed surveyed river cross-sections. FRIS provides extensive information regarding channel geometry on approximately 39,000 stream reaches (a slightly coarser spatial resolution than the NHD+v2 dataset) with tens of cross-sections for each reach. We use this FRIS data to calculate volume and discharge from floodplain riparian areas separately from in-channel flow during overbank events. Preliminary results suggest that a small percentage of total annual discharge interacts with the full floodplain extent along a stream reach due to the infrequency of overbank flow events. However, with the significantly different physical characteristics of the riparian area when compared to the channel itself, this overbank flow can provide unique services to water quality. Our project aims to use this information in conjunction with data from the USGS SPARROW program to target non-point source hotspots of Nitrogen and Phosphorus addition and removal. By better understanding the flow dynamics within riparian areas during high flow events, riparian restoration projects can be carried out with improved efficacy.

  15. Measuring Large Floods Events After Wildfires in the Western U.S.

    NASA Astrophysics Data System (ADS)

    Robichaud, P. R.

    2006-12-01

    Severe erosion after wildfires is the second most visible effect after the fire itself. During short duration, high rainfall intensity events in the first few years after a wildfire, large runoff and erosion events can occur. Several paired watershed sites that were established to determine the effectiveness of postfire emergency stabilization treatments have received large rainfall events--greater than 2-year return period events based on rainfall intensity. Paired watershed sites (each about 5 ha) were located in California, Colorado, and Montana after high burn severity wildfires. The rainfall events that followed occurred from one to three years after the fire. The 10-minute maximum rainfall intensities were between 30 and 150 mm/hr, which corresponds to between 2 and 50 year return interval events. These short duration, high intensity events generally lasted less than one hour and produced hillslope erosion rates of from 10 to 40 t/ha. During these events, little benefit is observed from such emergency stabilization treatments as contour-felled log erosion barriers, as the sediment yield from the treated and the untreated watersheds were similar for these intense events. Rill erosion was observed to be the dominant hillslope erosion mechanism in these steep post-fire forest environments. These results suggest that greater than a threshold of a two-year return interval rainfall event--based on rainfall intensity-- will produce significant erosion and that the postfire stabilization treatment has little effect for reducing erosion for these events.

  16. Monitoring Distributed Snow Cover Characteristics and Snowmelt Energy Balance Terms Before and During Snowmelt Induced Flood Events

    NASA Astrophysics Data System (ADS)

    Pohl, S.; Garvelmann, J.; Weiler, M.

    2013-12-01

    Severe flooding events as a result of rapid snowmelt often enhanced by the occurrence of rain on snow have become a more and more pressing concern for many regions of the world. A reliable forecast of these events relies heavily on an accurate knowledge of the drivers and characteristics (SWE, albedo, surface temperature, amount of snow intercepted in trees) of a mountain snow cover and their spatial pattern ahead of the snowmelt event. Furthermore, the temporal and spatial distribution of the energy fluxes leading to a rapid snowmelt during the event also needs to be understood. The presented study was carried out in the Black Forest region of south-western Germany. We installed a network of 100 standalone snow monitoring stations (SnoMoS) that continuously monitor snow depth and all relevant meteorological variables needed to calculate a full (snow) surface energy balance along with 45 time lapse cameras recording hourly information on several additional snow cover characteristics. The deployment locations were chosen to cover a wide range of elevations and expositions and under a variety of vegetation covers to monitor the influence of vegetation on snow cover evolution and snowmelt energy. Several statistical models were used to spatially analyze and regionalize the snow cover ahead of severe winter floods. This spatially distributed snow cover was then compared against the output from several hydrologic (snow-) model predictions to show strengths and weaknesses of these models. For example, a multiple linear regression approach showed the predictive capability of factors such as elevation, aspect, and land cover and how their respective importance changes over the winter period as a response to snow accumulation and melt cycles. The observation of the climate variables during a melt event gives further insight into how climate variables change over time and space and what regionalization approaches might work best to interpolate climate variables from few

  17. Dynamic Response of Watershed Subsurface Systems to Extreme Precipitation Events - Implications for the 2013 Colorado Front Range Floods

    NASA Astrophysics Data System (ADS)

    Henning, S. R.; Ge, S.

    2015-12-01

    In September 2013, the Boulder Creek watershed (BCW) was severely affected by a 1000-year precipitation event when 17 inches of rain - nearly the annual average - fell over Boulder, Colorado, USA in just eight days. This rainfall caused an unprecedented flood within the BCW. While the enormous amount of water that fell appeared to have left within days, we hypothesize that a majority of the water that fell during the event was not discharged via surface runoff, but infiltrated into the subsurface. This study aims to understand how the subsurface responds to extreme precipitation events by quantifying the volume of precipitation that infiltrates into the vadose zone, the change in subsurface water storage, and the spatial and temporal scale of these effects as caused by extreme events. This study focuses on a small drainage basin that lies within the BCW. This site is actively monitored and provides data of importance for hydrologic modeling. The data include groundwater elevation, soil moisture, stream discharge, and precipitation records. The hydrologic structure of the basin consists of a thin, sandy soil layer that caps weathered regolith and saprolite sourced from underlying crystalline basement bedrock. We use the HYDRUS model to numerically solve the Richards equation for variably saturated flow to simulate 2D groundwater flow both below the groundwater table and in the vadose zone. Average annual precipitation values and groundwater elevation measurements are used to estimate the initial subsurface conditions prior to the event. Atmospheric boundary conditions estimated from meteorological stations are then applied to the top of the model to simulate the extreme event. Preliminary results indicate that the extreme event led to a rise in the groundwater table of up to a meter at low-lying elevations near basin drainages and up to two meters below hillslopes that persisted for over a month after the rain stopped.

  18. The use of water marks mapping to understand flood overflow events inside karstic cavities: Cueva Fría and Cueva Rosa (Asturias, NW Spain)

    NASA Astrophysics Data System (ADS)

    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

  19. Global flood hazard mapping using statistical peak flow estimates

    NASA Astrophysics Data System (ADS)

    Herold, C.; Mouton, F.

    2011-01-01

    Our aim is to produce a world map of flooded areas for a 100 year return period, using a method based on large rivers peak flow estimates derived from mean monthly discharge time-series. Therefore, the map is supposed to represent flooding that affects large river floodplains, but not events triggered by specific conditions like coastal or flash flooding for instance. We first generate for each basin a set of hydromorphometric, land cover and climatic variables. In case of an available discharge record station at the basin outlet, we base the hundred year peak flow estimate on the corresponding time-series. Peak flow magnitude for basin outlets without gauging stations is estimated by statistical means, performing several regressions on the basin variables. These peak flow estimates enable the computation of corresponding flooded areas using hydrologic GIS processing on digital elevation model.

  20. High Resolution Simulations of a Severe Hail Storm and Flooding Event over La Paz city with WRF

    NASA Astrophysics Data System (ADS)

    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.

  1. Effect of flood events on transport of suspended sediments, organic matter and particulate metals in a forest watershed in the Basque Country (Northern Spain).

    PubMed

    Peraza-Castro, M; Sauvage, S; Sánchez-Pérez, J M; Ruiz-Romera, E

    2016-11-01

    An understanding of the processes controlling sediment, organic matter and metal export is critical to assessing and anticipating risk situations in water systems. Concentrations of suspended particulate matter (SPM), dissolved (DOC) and particulate (POC) organic carbon and metals (Cu, Ni, Pb, Cr, Zn, Mn, Fe) in dissolved and particulate phases were monitored in a forest watershed in the Basque Country (Northern Spain) (31.5km(2)) over three hydrological years (2009-2012), to evaluate the effect of flood events on the transport of these materials. Good regression was found between SPM and particulate metal concentration, making it possible to compute the load during the twenty five flood events that occurred during the study period at an annual scale. Particulate metals were exported in the following order: Fe>Mn>Zn>Cr>Pb>Cu>Ni. Annual mean loads of SPM, DOC and POC were estimated at 2267t, 104t and 57t, respectively, and the load (kg) of particulate metals at 76 (Ni), 83 (Cu), 135 (Pb), 256 (Cr), 532 (Zn), 1783 (Mn) and 95170 (Fe). Flood events constituted 91%-SPM, 65%-DOC, 71%-POC, 80%-Cu, 85%-Ni, 72%-Pb, 84%-Cr, 74%-Zn, 87%-Mn and 88%-Fe of total load exported during the three years studied. Flood events were classified into three categories according to their capacity for transporting organic carbon and particulate metals. High intensity flood events are those with high transport capacity of SPM, organic carbon and particulate metals. Most of the SPM, DOC, POC and particulate metal load was exported by this type of flood event, which contributed 59% of SPM, 45% of organic carbon and 54% of metals. PMID:27392333

  2. Large snowmelt versus rainfall events in the mountains

    NASA Astrophysics Data System (ADS)

    Fassnacht, Steven R.; Records, Rosemary M.

    2015-03-01

    While snow is the dominant precipitation type in mountain regions, estimates of rainfall are used for design, even though snowmelt provides most of the runoff. Daily data were used to estimate the 10 and 100 year, 24 h snowmelt, precipitation, and rainfall events at 90 Snow Telemetry stations across the Southern Rocky Mountains. Three probability distributions were compared, and the Pearson type III distribution yielded the most conservative estimates. Precipitation was on average 33% and 28% more than rainfall for the 10 and 100 year events. Snowfall exceeded rainfall at most of the stations and was on average 53% and 38% more for the 10 and 100 year events. On average, snowmelt was 15% and 8.9% more than precipitation. Where snow accumulation is substantial, it is recommended that snowmelt be considered in conjunction with rainfall and precipitation frequencies to develop flood frequencies.

  3. The role of the sea on the flash floods events over Liguria (northwestern Italy)

    NASA Astrophysics Data System (ADS)

    Cassola, F.; Ferrari, F.; Mazzino, A.; Miglietta, M. M.

    2016-04-01

    The sensitivity to sea surface temperature (SST) of small-scale, flood-causing convective systems in Mediterranean coastal areas is analyzed by means of mesoscale numerical simulations. Two different SST initializations are considered: a coarse field provided by a global atmospheric model and a high-resolution multisatellite analysis. Quantitative precipitation forecasts are evaluated for a number of recent severe rainfall episodes in Liguria (northwestern Italy). In several cases, using a higher-resolution SST leads to more realistic precipitation estimates in the forecasting range 36-48 h. In the shorter range, the satellite SST has a limited, or even negative, impact, due to the relatively slow adjustment of initial atmospheric fields. In one case, the satellite SST is beneficial for the only run forced with accurate large-scale initial conditions. The results of this work suggest that a potentially significant improvement in severe precipitation forecasting in the Mediterranean could be achieved using realistic small-scale SST fields.

  4. Effects of Riparian Vegetation on Topographic Change During a Large Flood Event, Rio Puerco, New Mexico

    NASA Astrophysics Data System (ADS)

    Perignon, M. C.; Tucker, G. E.; Griffin, E. R.; Friedman, J. M.

    2012-12-01

    The nature and pattern of vegetation on floodplains strongly affect the morphological changes that result from large floods by increasing drag and steering the flow through the landscape. Quantifying those changes is only possible through the use of high-resolution, multi-temporal topographic datasets. In 2003, herbicides were sprayed on a section of the Rio Puerco, New Mexico, killing the tamarisk and sandbar willow on the floodplain and banks. A large flood in 2006 caused extensive erosion along the devegetated zone, widening the channel and eroding the floodplain. We use lidar differencing to quantify the topographic change that occurred along a 12-km reach of the arroyo immediately downstream of the sprayed section. We show that the pattern of deposition on the floodplain can be explained as the sum of two signals: the sediment concentration (which depends on the distance downstream of the sprayed reach), and local vegetation density. The presence of dense vegetation on the landscape, regardless of size or species, increases deposition by imparting a drag on the flow and reducing the boundary shear stress on the sediment surface. The spatial variability of sediment depth correlates with the size and spacing of stems: thick, widely spaced tamarisk trunks are associated with high variability in the depth of sedimentation, while dense but thin tamarisk and sandbar willow stems correlate with sheet-like deposits. Away from the influence of the sediment source, the erosion of the arroyo walls balances the deposition rate on the floodplain, resulting in widespread, uniform aggradation of the arroyo bottom.

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

    NASA Astrophysics Data System (ADS)

    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

  6. Challenges in Downscaling Surge and Flooding Predictions Associated with Major Coastal Storm Events

    NASA Astrophysics Data System (ADS)

    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".

  7. Sedimentary infill dynamic and associated trace element temporal trends in a dam reservoir: evidence of high polluted sediment storage after major flood events (Upper Loire river, France)

    NASA Astrophysics Data System (ADS)

    Dhivert, Elie; Grosbois, Cécile; Desmet, Marc; Coynel, Alexandra; Lefevre, Irène

    2014-05-01

    The Villerest Dam, was built in the Upper Loire river during the early 1980's, 80 km downstream of the most important industrial and coal mining area of the basin. It constitutes an important trap of sediments and associated pollutants since its operation in 1984. A 154 cm long core was sampled in 2010, in a former channel levee in the reservoir. This study highlights (i) important sediment accumulation rate during flood events in the reservoir, (ii) the influence of high discharge events in sedimentary infill in terms of stored sediment quality, geochemical markers and anthropogenic sources influence. Coupling sedimentological analyses and 137Cs datation allows to define 3 sedimentary units in this core. The deepest unit corresponds to transported and/or reworked fluvial sediments undated, the uppermost unit to lacustrine sediments post 1984 and between, to a transition unit resulting from the reservoir water infilling in 1983-1984. In addition, the upper unit shows 3 turbiditic-like layers (of 6, 20 and 13 cm thick) corresponding respectively to 1996, 2003 and 2008 major flood events (more than 20-year flood average daily outflow). These flood sequences result from underflow sedimentary inputs and contribute to 43% of the 151 kg/m² of accumulated sediments since 1984. Over the 1984-2010 period, sediments show a general contamination decrease but major flood events transport highly impacted sediments (highest enrichment factor > 20 for Hg and >10 for Cd and Bi), never reached during interflood periods. During these events, trace elements (TE) are mostly associated to organic fraction and clays. Rich-TE solid sources appear to be only solicited, and/or severely amplified, during important flood events over the recording period. In addition to these pollutants inputs, floods also bring an important detrital fraction, diluting anthropogenic TE signal. In details, flood deposits show variations of sedimentological and geochemical signals delimiting two distinct

  8. Spatial Scaling of Floods in Atlantic Coastal Watersheds

    NASA Astrophysics Data System (ADS)

    Plank, C.

    2013-12-01

    Climate and land use changes are altering global, regional and local hydrologic cycles. As a result, past events may not accurately represent the events that will occur in the future. Methods for hydrologic prediction, both statistical and deterministic, require adequate data for calibration. Streamflow gauges tend to be located on large rivers. As a result, statistical flood frequency analysis, which relies on gauge data, is biased towards large watersheds. Conversely, the complexity of parameterizing watershed processes in deterministic hydrological models limits these to small watersheds. Spatial scaling relationships between drainage basin area and discharge can be used to bridge these two methodologies and provide new approaches to hydrologic prediction. The relationship of discharge (Q) to drainage basin area (A) can be expressed as a power function: Q = αAθ. This study compares scaling exponents (θ) and coefficients (α) for floods of varying magnitude across a selection of major Atlantic Coast watersheds. Comparisons are made by normalizing flood discharges to a reference area bankfull discharge for each watershed. These watersheds capture the geologic and geomorphic transitions along the Atlantic Coast from narrow bedrock-dominated river valleys to wide coastal plain watersheds. Additionally, there is a range of hydrometeorological events that cause major floods in these basins including tropical storms, thunderstorm systems and winter-spring storms. The mix of flood-producing events changes along a gradient as well, with tropical storms and hurricanes increasing in dominance from north to south as a significant cause of major floods. Scaling exponents and coefficients were determined for both flood quantile estimates (e.g. 1.5-, 10-, 100-year floods) and selected hydrometeorological events (e.g. hurricanes, summer thunderstorms, winter-spring storms). Initial results indicate that southern coastal plain watersheds have lower scaling exponents (θ) than

  9. Evaluation of High-Resolution Precipitation Estimates from Satellites during July 2012 Beijing Flood Event Using Dense Rain Gauge Observations

    PubMed Central

    Chen, Sheng; Liu, Huijuan; You, Yalei; Mullens, Esther; Hu, Junjun; Yuan, Ye; Huang, Mengyu; He, Li; Luo, Yongming; Zeng, Xingji; Tang, Guoqiang; Hong, Yang

    2014-01-01

    Satellite-based precipitation estimates products, CMORPH and PERSIANN-CCS, were evaluated with a dense rain gauge network over Beijing and adjacent regions for an extremely heavy precipitation event on July 21 2012. CMORPH and PEERSIANN-CSS misplaced the region of greatest rainfall accumulation, and failed to capture the spatial pattern of precipitation, evidenced by a low spatial correlation coefficient (CC). CMORPH overestimated the daily accumulated rainfall by 22.84% while PERSIANN-CCS underestimated by 72.75%. In the rainfall center, both CMORPH and PERSIANN-CCS failed to capture the temporal variation of the rainfall, and underestimated rainfall amounts by 43.43% and 87.26%, respectively. Based on our results, caution should be exercised when using CMORPH and PERSIANN-CCS as input for monitoring and forecasting floods in Beijing urban areas, and the potential for landslides in the mountainous zones west and north of Beijing. PMID:24691358

  10. Evaluation of high-resolution precipitation estimates from satellites during July 2012 Beijing flood event using dense rain gauge observations.

    PubMed

    Chen, Sheng; Liu, Huijuan; You, Yalei; Mullens, Esther; Hu, Junjun; Yuan, Ye; Huang, Mengyu; He, Li; Luo, Yongming; Zeng, Xingji; Tang, Guoqiang; Hong, Yang

    2014-01-01

    Satellite-based precipitation estimates products, CMORPH and PERSIANN-CCS, were evaluated with a dense rain gauge network over Beijing and adjacent regions for an extremely heavy precipitation event on July 21 2012. CMORPH and PEERSIANN-CSS misplaced the region of greatest rainfall accumulation, and failed to capture the spatial pattern of precipitation, evidenced by a low spatial correlation coefficient (CC). CMORPH overestimated the daily accumulated rainfall by 22.84% while PERSIANN-CCS underestimated by 72.75%. In the rainfall center, both CMORPH and PERSIANN-CCS failed to capture the temporal variation of the rainfall, and underestimated rainfall amounts by 43.43% and 87.26%, respectively. Based on our results, caution should be exercised when using CMORPH and PERSIANN-CCS as input for monitoring and forecasting floods in Beijing urban areas, and the potential for landslides in the mountainous zones west and north of Beijing. PMID:24691358

  11. Extreme Rainfall and Flood Events for the Hudson River Induced by Tropical Cyclones: a Statistical Forecast Model

    NASA Astrophysics Data System (ADS)

    Conticello, F.; Hall, T. M.; Lall, U.; Orton, P. M.; Cioffi, F.; Georgas, N.

    2014-12-01

    Tropical Cyclones (TCs) lead to potentially severe coastal flooding through wind surge and also through rainfall-runoff processes. There is growing interest in modeling these processes simultaneously. Here, a statistical approach that can facilitate this process is presented with an application to the Hudson River Basin that is associated with the New York City metropolitan area. Three submodels are used in sequence. The first submodel is a stochastic model of the complete life cycle of North Atlantic (NA) tropical cyclones developed by Hall and Yonekura (2011). It uses archived data of TCs throughout the North Atlantic to estimate landfall rates at high geographic resolution as a function of the ENSO state and of sea surface temperature (SST). The second submodel translates the attributes of a tropical cyclone simulated by the first model to the streamflows at specific points of the tributaries of the Hudson River. That points are the closure sections of five different watersheds. Two different approaches are used and compared: 1) an ANN-cyclone/rainfall clustering model which calculates the rainfall intensity at selected stations within the watershed, that are then used as inputs of an ANN rainfall/runoff model; 2) an ANN/ Bayesian multivariate approach that translates the TC attributes ( track, SST, Velocities,..) directly in streamflows in the tributaries. Finally, the streamflows of the tributaries of the Hudson River are to be used as inputs in a hydrodynamic model that includes storm surge dynamics for the simulation of coastal flooding along the Hudson River. Calibration and validation of the model is carried out by using, selected tropical cyclone data since 1950, and hourly and daily station rainfall and streamflow recorded for such extreme events. Seven stream gauges (Croton River, Rondout Creek, Wappinger Creek, Troy dam, Mohawk River at Cohoes, Mohawk River diversion at Crescent Dam, Hudson River above lock one nr Waterford) and over 20 rain gauges are

  12. Simulation of water-surface elevations for a hypothetical 100-year peak flow in Birch Creek at the Idaho National Engineering and Environmental Laboratory, Idaho

    SciTech Connect

    Berenbrock, C.; Kjelstrom, L.C.

    1997-10-01

    Delineation of areas at the Idaho National Engineering and Environmental Laboratory that would be inundated by a 100-year peak flow in Birch Creek is needed by the US Department of Energy to fulfill flood-plain regulatory requirements. Birch Creek flows southward about 40 miles through an alluvium-filled valley onto the northern part of the Idaho National Engineering and Environmental laboratory site on the eastern Snake River Plain. The lower 10-mile reach of Birch Creek that ends in Birch Creek Playa near several Idaho National Engineering and Environmental Laboratory facilities is of particular concern. Twenty-six channel cross sections were surveyed to develop and apply a hydraulic model to simulate water-surface elevations for a hypothetical 100-year peak flow in Birch Creek. Model simulation of the 100-year peak flow (700 cubic feet per second) in reaches upstream from State Highway 22 indicated that flow was confined within channels even when all flow was routed to one channel. Where the highway crosses Birch Creek, about 315 cubic feet per second of water was estimated to move downstream--115 cubic feet per second through a culvert and 200 cubic feet per second over the highway. Simulated water-surface elevation at this crossing was 0.8 foot higher than the elevation of the highway. The remaining 385 cubic feet per second flowed southwestward in a trench along the north side of the highway. Flow also was simulated with the culvert removed. The exact location of flood boundaries on Birch Creek could not be determined because of the highly braided channel and the many anthropogenic features (such as the trench, highway, and diversion channels) in the study area that affect flood hydraulics and flow. Because flood boundaries could not be located exactly, only a generalized flood-prone map was developed.

  13. Helium isotopic evidence for modification of the cratonic lithosphere during the Permo-Triassic Siberian flood basalt event

    NASA Astrophysics Data System (ADS)

    Barry, Peter H.; Hilton, David R.; Day, James M. D.; Pernet-Fisher, John F.; Howarth, Geoffrey H.; Magna, Tomas; Agashev, Aleksey M.; Pokhilenko, Nikolay P.; Pokhilenko, Lyudmila N.; Taylor, Lawrence A.

    2015-02-01

    Major flood basalt emplacement events can dramatically alter the composition of the sub-continental lithospheric mantle (SCLM). The Siberian craton experienced one of the largest flood basalt events preserved in the geologic record - eruption of the Permo-Triassic Siberian flood basalts (SFB) at ~ 250 Myr in response to upwelling of a deep-rooted mantle plume beneath the Siberian SCLM. Here, we present helium isotope (3He/4He) and concentration data for petrologically-distinct suites of peridotitic xenoliths recovered from two temporally-separated kimberlites: the 360 Ma Udachnaya and 160 Ma Obnazhennaya pipes, which erupted through the Siberian SCLM and bracket the eruption of the SFB. Measured 3He/4He ratios span a range from 0.1 to 9.8 RA (where RA = air 3He/4He) and fall into two distinct groups: 1) predominantly radiogenic pre-plume Udachnaya samples (mean clinopyroxene 3He/4He = 0.41 ± 0.30 RA (1σ); n = 7 excluding 1 outlier), and 2) 'mantle-like' post plume Obnazhennaya samples (mean clinopyroxene 3He/4He = 4.20 ± 0.90 RA (1σ); n = 5 excluding 1 outlier). Olivine separates from both kimberlite pipes tend to have higher 3He/4He than clinopyroxenes (or garnet). Helium contents in Udachnaya samples ([He] = 0.13-1.35 μcm3STP/g; n = 6) overlap with those of Obnazhennaya ([He] = 0.05-1.58 μcm3STP/g; n = 10), but extend to significantly higher values in some instances ([He] = 49-349 μcm3STP/g; n = 4). Uranium and thorium contents are also reported for the crushed material from which He was extracted in order to evaluate the potential for He migration from the mineral matrix to fluid inclusions. The wide range in He content, together with consistently radiogenic He-isotope values in Udachnaya peridotites suggests that crustal-derived fluids have incongruently metasomatized segments of the Siberian SCLM, whereas high 3He/4He values in Obnazhennaya peridotites show that this section of the SCLM has been overprinted by Permo-Triassic (plume-derived) basaltic

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

    PubMed Central

    Jokiel, Paul L.; Rodgers, Kuʻulei S.

    2015-01-01

    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” actually started long

  15. Catastrophic impact of extreme flood events on the morphology and evolution of the lower Jökulsá á Fjöllum (northeast Iceland) during the Holocene

    NASA Astrophysics Data System (ADS)

    Baynes, Edwin R. C.; Attal, Mikaël; Dugmore, Andrew J.; Kirstein, Linda A.; Whaler, Kathryn A.

    2015-12-01

    The impact of extreme flood events is rarely considered in studies of long-term landscape evolution, despite the potential for catastrophic landscape change in a short period of time. Here, we use an integrated approach of geomorphological mapping, topographic analysis and geophysical surveys to identify and quantify the impact of extreme flood events (jökulhlaups) along the Jökulsá á Fjöllum, Iceland, where evidence for the action of such floods is widespread on microspatial to macrospatial scales. The apex of the 28-km-long Jökulsárgljúfur canyon is characterised by a complex network of palaeo-flood channels and large vertical knickpoints such as Dettifoss (54 m high) and Hafragilsfoss (20 m high). Downstream, the Forvoð valley contains large terraces of boulder-rich deposits (50 m thick, > 3 km long). Near the outlet of the canyon is Ásbyrgi, a dry canyon (3 km long, 1 km wide, up to 90 m deep) with eroded cataracts and scabland morphology immediately upstream and ~ 90 m above the current river channel. Topographic analysis and electrical resistivity tomography surveys show that 0.144 km3 of rock was eroded from Ásbyrgi during its formation ~ 10,000 years ago, and just 4% of this eroded volume is currently filled with sediment deposits, up to 5 m thick. Deposited boulders across the canyon floor of Ásbyrgi demonstrate that the discharge of the jökulhlaup that formed the canyon was at least 39,000 m3 s- 1. We present a model for the evolution of the lower Jökulsá á Fjöllum and the Jökulsárgljúfur canyon during various stages of an extreme flood event. Reconstruction of the early Holocene flood event includes the initiation and development of different canyons before the capture of all floodwater within one canyon at the end. We tie the evolution of the lower Jökulsárgljúfur canyon to established chronology of flood events during the Holocene farther upstream and highlight the dominant impact of extreme flood events over background processes

  16. Flash floods and debris flow: how the risk could can be better managed? The case of the events in Sicily on October 2009

    NASA Astrophysics Data System (ADS)

    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

  17. Seawater osmium isotope evidence for a middle Miocene flood basalt event in ferromanganese crust records

    USGS Publications Warehouse

    Klemm, V.; Frank, M.; Levasseur, S.; Halliday, A.N.; Hein, J.R.

    2008-01-01

    Three ferromanganese crusts from the northeast, northwest and central Atlantic were re-dated using osmium (Os) isotope stratigraphy and yield ages from middle Miocene to the present. The three Os isotope records do not show evidence for growth hiatuses. The reconstructed Os isotope-based growth rates for the sections older than 10??Ma are higher than those determined previously by the combined beryllium isotope (10Be/9Be) and cobalt (Co) constant-flux methods, which results in a decrease in the maximum age of each crust. This re-dating does not lead to significant changes to the interpretation of previously determined radiogenic isotope neodymium, lead (Nd, Pb) time series because the variability of these isotopes was very small in the records of the three crusts prior to 10??Ma. The Os isotope record of the central Atlantic crust shows a pronounced minimum during the middle Miocene between 15 and 12??Ma, similar to a minimum previously observed in two ferromanganese crusts from the central Pacific. For the other two Atlantic crusts, the Os isotope records and their calibration to the global seawater curve for the middle Miocene are either more uncertain or too short and thus do not allow for a reliable identification of an isotopic minimum. Similar to pronounced minima reported previously for the Cretaceous/Tertiary and Eocene/Oligocene boundaries, possible interpretations for the newly identified middle Miocene Os isotope minimum include changes in weathering intensity and/or a meteorite impact coinciding with the formation of the No??rdlinger Ries Crater. It is suggested that the eruption and weathering of the Columbia River flood basalts provided a significant amount of the unradiogenic Os required to produce the middle Miocene minimum. ?? 2008 Elsevier B.V.

  18. Sparsity-weighted outlier FLOODing (OFLOOD) method: Efficient rare event sampling method using sparsity of distribution.

    PubMed

    Harada, Ryuhei; Nakamura, Tomotake; Shigeta, Yasuteru

    2016-03-30

    As an extension of the Outlier FLOODing (OFLOOD) method [Harada et al., J. Comput. Chem. 2015, 36, 763], the sparsity of the outliers defined by a hierarchical clustering algorithm, FlexDice, was considered to achieve an efficient conformational search as sparsity-weighted "OFLOOD." In OFLOOD, FlexDice detects areas of sparse distribution as outliers. The outliers are regarded as candidates that have high potential to promote conformational transitions and are employed as initial structures for conformational resampling by restarting molecular dynamics simulations. When detecting outliers, FlexDice defines a rank in the hierarchy for each outlier, which relates to sparsity in the distribution. In this study, we define a lower rank (first ranked), a medium rank (second ranked), and the highest rank (third ranked) outliers, respectively. For instance, the first-ranked outliers are located in a given conformational space away from the clusters (highly sparse distribution), whereas those with the third-ranked outliers are nearby the clusters (a moderately sparse distribution). To achieve the conformational search efficiently, resampling from the outliers with a given rank is performed. As demonstrations, this method was applied to several model systems: Alanine dipeptide, Met-enkephalin, Trp-cage, T4 lysozyme, and glutamine binding protein. In each demonstration, the present method successfully reproduced transitions among metastable states. In particular, the first-ranked OFLOOD highly accelerated the exploration of conformational space by expanding the edges. In contrast, the third-ranked OFLOOD reproduced local transitions among neighboring metastable states intensively. For quantitatively evaluations of sampled snapshots, free energy calculations were performed with a combination of umbrella samplings, providing rigorous landscapes of the biomolecules. PMID:26611770

  19. Tidal sediment transport versus freshwater flood events in the Konkouré Estuary, Republic of Guinea

    NASA Astrophysics Data System (ADS)

    Capo, Sylvain; Brenon, Isabelle; Sottolichio, Aldo; Castaing, Patrice; Le Goulven, Patrick

    2009-09-01

    In comparison to their temperate counterparts, sediment processes in tropical estuaries are poorly known and especially in African ones. The hydrodynamics of such environments is controlled by a combination of multiple processes including morphology, salinity, mangrove vegetation, tidal processes, river discharge, settling and erosion of mud and by physico-chemical processes as well as sediment dynamics. The aim of this study is to understand the sediment processes in this transitional stage of the estuary when the balance between river discharges and marine processes is reversing. Studying the hydrodynamics and sediment dynamics of the Konkouré Estuary has recently been made possible thanks to new data on bathymetry, sedimentary cover, salinity, water elevations, and current velocities. The Lower Konkouré is a shallow, funnel shaped, mesotidal mangrove-fringed, tide-dominated estuary, well mixed during low river discharge and stratified during high river discharge. The Konkouré Estuary is turbid despite the small amount of terrestrial input and its residual velocity at the mouth during low river discharges, landwards for two of the three branches, suggests a landward migration by tidal pumping of the suspended particulate matter. A Turbidity Maximum Zone (TMZ) is identified for typical states of the estuary with regard to fluvial and tidal components. Suspended sediment transport during a transitional stage between the rainy and dry seasons is known thanks to current velocity and Suspended Sediment Concentration (SSC) measurements taken in November 2003. The Richardson layered number calculation assesses that turbulence is the major mixing process in the water column, at least during the flood and ebb stages, whereas stratification occurs during the slack water periods. Tidal currents generate bottom erosion, and turbulence mixes the suspended sediment throughout the water column. As a result, a net sediment input is calculated from the western Konkouré outlet

  20. SurgeWatch: a user-friendly database of coastal flooding in the United Kingdom from 1915-2014

    NASA Astrophysics Data System (ADS)

    Wadey, Matthew; Haigh, Ivan; Nicholls, Robert J.; Ozsoy, Ozgun; Gallop, Shari; Brown, Jennifer; Horsburgh, Kevin; Bradshaw, Elizabeth

    2016-04-01

    Coastal flooding caused by extreme sea levels can be devastating, with long-lasting and diverse consequences. Historically, the UK has suffered major flooding events, and at present 2.5 million properties and £150 billion of assets are potentially exposed to coastal flooding. However, no formal system is in place to catalogue which storms and high sea level events progress to coastal flooding. Furthermore, information on the extent of flooding and associated damages is not systematically documented nationwide. Here we present a database and online tool called 'SurgeWatch', which provides a systematic UK-wide record of high sea level and coastal flood events over the last 100 years (1915-2014). Using records from the National Tide Gauge Network, with a dataset of exceedance probabilities and meteorological fields, SurgeWatch captures information of 96 storms during this period, the highest sea levels they produced, and the occurrence and severity of coastal flooding. The data are presented to be easily assessable and understandable to a range of users including, scientists, coastal engineers, managers and planners and concerned citizens. We also focus on some significant events in the database, such as the North Sea storm surge of 31 January-1 February 1953 (Northwest Europe's most severe coastal floods in living memory) and the 5-6 December 2013 "Xaver" Storm and floods.

  1. Technique for estimating depth of floods in Tennessee

    USGS Publications Warehouse

    Gamble, C.R.

    1983-01-01

    Estimates of flood depths are needed for design of roadways across flood plains and for other types of construction along streams. Equations for estimating flood depths in Tennessee were derived using data for 150 gaging stations. The equations are based on drainage basin size and can be used to estimate depths of the 10-year and 100-year floods for four hydrologic areas. A method also was developed for estimating depth of floods having recurrence intervals between 10 and 100 years. Standard errors range from 22 to 30 percent for the 10-year depth equations and from 23 to 30 percent for the 100-year depth equations. (USGS)

  2. Floods and Flash Flooding

    MedlinePlus

    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 ...

  3. The August 2002 flood in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Sercl, P.; Stehlik, J.

    2003-04-01

    The floods in August 2002 in the Czech Republic were caused by very intensive and large-scale rainfall that hit mainly the southern and western part of the country. There were two following rainfall events, the first on the {6th} and {7th} August and the second on the {11th} and {12th} August. The total sum of areal rainfall was 150 to 200 mm; in mountain areas more than 250 mm and in some localities even more than 300 mm. Such large-scale rainfall amounts are extraordinary for Czech conditions. The first wave of rainfall caused floods in the majority of rivers. There were 10 to 20 year floods, exceptionally 100-year (and more) floods on rivers in the southern and western part of the country. When the second wave of rainfall followed the first one, rivers were already full of water and soils were saturated: therefore the runoff response was rapid and massive. Water levels in all rivers rose very quickly again and they reached their historical maxima in many places. Peak discharges in most streams reached or exceeded a 100-year flood and in some rivers a 1000-year flood. The capital of the Czech Republic, Prague, is situated at the confluence of two rivers, the Moldau and the Berounka (left hand tributary of the Moldau). The flow in the Moldau River can be partly controlled by operation of many reservoirs in the upstream reaches of the river (the Moldau cascade), the flow in Berounka is not influenced. During the first flood event the major part of the wave was retained by the reservoirs and the discharge in Prague was reduced. During the second event the inflow into the reservoir system was so high that reservoirs were filled before the peak occurred. The peak flow from the Berounka River coincided with the maximum outflow from the Moldau. As a consequence, on 14th August the peak discharge in Prague was about 5200 {m3/s} (the long-term mean discharge is 150 {m3/s}) and is preliminarily judged to be a 500-year flood. The influence of the Moldau cascade on the

  4. Flood-event based metal distribution patterns in water as approach for source apportionment of pollution on catchment scale: Examples from the River Elbe

    NASA Astrophysics Data System (ADS)

    Baborowski, Martina; Einax, Jürgen W.

    2016-04-01

    With the implementation of European Water Frame Work Directive (EU-WFD), the pollution sources in the River Elbe were assessed by the River Basin Community Elbe (RBC Elbe). Contaminated old sediments played the most significant role for inorganic and organic pollution. In terms of further improvement of the water quality in the river system, a prioritization of the known pollution sources is necessary, with respect to the expected effect in the case of their remediation. This requires information on mobility of contaminated sediments. To create a tool that allows the assessment of pollution trends in the catchment area, event based flood investigations were carried out at a sampling site in the Middle Elbe. The investigations were based on a comparable, discharge related sampling strategy. Four campaigns were performed between 1995 and 2006. The majority of the investigated 16 elements (>80%) studied more intensively in 2006 reached its maximum concentration during the first five days of the event. Only the concentrations of B, Cl-, and U declined with increasing discharge during the flood. The aim of the study was to verify that each flood event is characterized by an internal structure of the water quality. This structure is formed by the appearance of maximum values of water quality parameters at different times during the event. It could be detected by descriptive and multivariate statistical methods. As a result, internal structure of the water quality during the flood was influenced primarily by the source of the metals in the catchment area and its distance from the sampling point. The transport of metals in dissolved, colloidal or particulate form and changes of their ratios during the flood were however, not decisive for the formation of the structure. Our results show that the comparison of the structures obtained from events in different years is indicative of the pollution trend in the catchment area. Exemplarily the trend of the metal pollution in the

  5. Abiotic variability among different aquatic systems of the central Amazon floodplain during drought and flood events.

    PubMed

    Affonso, A G; Queiroz, H L; Novo, E M L M

    2015-11-01

    This paper examines water properties from lakes, (depression lakes, sensu Junk et al., 2012), channels (scroll lakes with high connectivity, sensu Junk et al., 2012) and paleo-channels (scroll lakes with low connectivity-sensu Junk et al., 2012, locally called ressacas) located in Mamirauá Sustainable Development Reserve, in Central Amazon floodplain, Amazonas, Brazil. We analysed surface temperature, conductivity, pH, dissolved oxygen, turbidity, transparency, suspended inorganic and organic matter, chlorophyll-a, pheophytin, total nitrogen, total phosphorus, organic and inorganic carbon in 2009 high water phase, 2009 and 2010 low water phases. Multivariate statistical analyses of 24 aquatic systems (6 ressacas, 12 lakes and 6 channels, 142 samples) were applied to the variables in order to: 1) quantify differences among aquatic system types; 2) assess how those differences are affected in the different phases of the hydrological year. First, we analysed the entire set of variables to test for differences among phases of the hydrological year and types of aquatic systems using a PERMANOVA two-way crossed design. The results showed that the all measured limnological variables are distinct regarding both factors: types of aquatic systems and hydrological phases. In general, the magnitude and amplitude of all variables were higher in the low water phase than in the high water phase, except for water transparency in all aquatic system's types. PERMANOVA showed that the differences between aquatic system's types and hydrological phases of all variables were highly significant for both main factors (type and phase) and for the type x phase interaction. Limnological patterns of Amazon floodplain aquatic systems are highly dynamic, dependent on the surrounding environment, flood pulse, main river input and system type. These patterns show how undisturbed systems respond to natural variability in such a diverse environment, and how distinct are those aquatic systems

  6. Thunderstorms and Flooding of August 17, 2007, with a Context Provided by a History of Other Large Storm and Flood Events in the Black Hills Area of South Dakota

    USGS Publications Warehouse

    Driscoll, Daniel G.; Bunkers, Matthew J.; Carter, Janet M.; Stamm, John F.; Williamson, Joyce E.

    2010-01-01

    The Black Hills area of western South Dakota has a history of damaging flash floods that have resulted primarily from exceptionally strong rain-producing thunderstorms. The best known example is the catastrophic storm system of June 9-10, 1972, which caused severe flooding in several major drainages near Rapid City and resulted in 238 deaths. More recently, severe thunderstorms caused flash flooding near Piedmont and Hermosa on August 17, 2007. Obtaining a thorough understanding of peak-flow characteristics for low-probability floods will require a comprehensive long-term approach involving (1) documentation of scientific information for extreme events such as these; (2) long-term collection of systematic peak-flow records; and (3) regional assessments of a wide variety of peak-flow information. To that end, the U.S. Geological Survey cooperated with the South Dakota Department of Transportation and National Weather Service to produce this report, which provides documentation regarding the August 17, 2007, storm and associated flooding and provides a context through examination of other large storm and flood events in the Black Hills area. The area affected by the August 17, 2007, storms and associated flooding generally was within the area affected by the larger storm of June 9-10, 1972. The maximum observed 2007 precipitation totals of between 10.00 and 10.50 inches occurred within about 2-3 hours in a small area about 5 miles west of Hermosa. The maximum documented precipitation amount in 1972 was 15.0 inches, and precipitation totals of 10.0 inches or more were documented for 34 locations within an area of about 76 square miles. A peak flow of less than 1 cubic foot per second occurred upstream from the 2007 storm extent for streamflow-gaging station 06404000 (Battle Creek near Keystone); whereas, the 1972 peak flow of 26,200 cubic feet per second was large, relative to the drainage area of only 58.6 square miles. Farther downstream along Battle Creek, a 2007

  7. Investigating the evolution of gravel bar at river confluence during flood events using a 2D many-fraction river morphodynamic model

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Wu, F.; Ecohydraulics Lab.

    2010-12-01

    The knowledge of river morphology is fundamental and useful information for engineering and habitat restoration purposes. Many interesting phenomena such as armoring and downstream fining significantly affect the quality of riverine habitats. These phenomena could be even more devastating when they occur during the extreme flood events. Therefore, the development of meso-scale bedforms during flood events and the change in their sediment composition have become important topics of study. However, the complex interactions between flood flow, nonuniform particles and sediment transport make these problems difficult to tackle. In this study, we develop a 2D (two-dimensional) many-fraction FE (finite element) morphodynamic model to investigate the evolution of gravel bar during flood events. The proposed model adopts the characteristic dissipative Galerkin (CDG) scheme such that the convection-dominated bar evolution can be computed without numerical instabilities. A two-year record of DEM (digital elevation model) is obtained by airborne Lidar at the confluence of the Xin-Dian River (Taiwan), which is used to verify the model results. The proposed model is further applied to determine the best operation scheme of the Feitsui reservoir for mitigating blockage of river confluence by the gravel bar and sustaining the bed composition favorable to the river biota.

  8. Developments in large-scale coastal flood hazard mapping

    NASA Astrophysics Data System (ADS)

    Vousdoukas, Michalis I.; Voukouvalas, Evangelos; Mentaschi, Lorenzo; Dottori, Francesco; Giardino, Alessio; Bouziotas, Dimitrios; Bianchi, Alessandra; Salamon, Peter; Feyen, Luc

    2016-08-01

    Coastal flooding related to marine extreme events has severe socioeconomic impacts, and even though the latter are projected to increase under the changing climate, there is a clear deficit of information and predictive capacity related to coastal flood mapping. The present contribution reports on efforts towards a new methodology for mapping coastal flood hazard at European scale, combining (i) the contribution of waves to the total water level; (ii) improved inundation modeling; and (iii) an open, physics-based framework which can be constantly upgraded, whenever new and more accurate data become available. Four inundation approaches of gradually increasing complexity and computational costs were evaluated in terms of their applicability to large-scale coastal flooding mapping: static inundation (SM); a semi-dynamic method, considering the water volume discharge over the dykes (VD); the flood intensity index approach (Iw); and the model LISFLOOD-FP (LFP). A validation test performed against observed flood extents during the Xynthia storm event showed that SM and VD can lead to an overestimation of flood extents by 232 and 209 %, while Iw and LFP showed satisfactory predictive skill. Application at pan-European scale for the present-day 100-year event confirmed that static approaches can overestimate flood extents by 56 % compared to LFP; however, Iw can deliver results of reasonable accuracy in cases when reduced computational costs are a priority. Moreover, omitting the wave contribution in the extreme total water level (TWL) can result in a ˜ 60 % underestimation of the flooded area. The present findings have implications for impact assessment studies, since combination of the estimated inundation maps with population exposure maps revealed differences in the estimated number of people affected within the 20-70 % range.

  9. Bioavailability of Mercury to Riverine Food Webs as a Function of Flood-Event Inundation of Channel Boundary Sediments

    NASA Astrophysics Data System (ADS)

    Singer, M. B.; Pellachini, C.; Blum, J. D.; Marvin-DiPasquale, M. C.; Donovan, P. M.

    2013-12-01

    Bioavailability of sediment-adsorbed contaminants to food webs in river corridors is typically controlled by biological, chemical, and physical factors, but understanding of their respective influences is limited due to a dearth of landscape-scale investigations of these biogeochemical links. Studies that account for the dynamics and interactions of hydrology and sediment transport in affecting the reactivity of sediment-adsorbed heavy metals such as mercury (Hg) are particularly lacking. Sequences of flood events generate complex inundation histories with banks, terraces, and floodplains that have the potential to alter local redox conditions and thereby affect the oxidation of elemental Hg0 to inorganic Hg(II), and the microbial conversion of Hg(II) to methylmercury (MeHg), potentially increasing the risk of Hg uptake into aquatic food webs. However, the probability distributions of saturation/inundation frequency and duration are typically unknown for channel boundaries along sediment transport pathways, and landscape-scale characterizations of Hg reactivity are rare along contaminated rivers. This research provides the first links between the dynamics of physical processes and biochemical processing and uptake into food webs in fluvial systems beset by large-scale mining contamination. Here we present new research on Hg-contaminated legacy terraces and banks along the Yuba River anthropogenic fan, produced by 19th C. hydraulic gold mining in Northern California. To assess the changes in Hg(II) availability for methylation and MeHg bioavailability into the food web, we combine numerical modeling of streamflow with geochemical assays of total Hg and Hg reactivity to identify hot spots of toxicity within the river corridor as a function of cycles of wetting/drying. We employ a 3D hydraulic model to route historical streamflow hydrographs from major flood events through the Yuba and Feather Rivers into the Central Valley to assess the frequency and duration of

  10. Importance of record length with respect to estimating the 1-percent chance flood

    USGS Publications Warehouse

    Feaster, Toby D.

    2010-01-01

    U.S. Geological Survey (USGS) streamflow gages have been established in every State in the Nation, Puerto Rico, and the Trust Territory of the Pacific Islands. From these st reamflow records, estimates of the magnitude and frequency of floods are often developed and used to design transportation and water- conveyance structures to protect lives and property, and to determine flood-insurance rates. Probably the most recognizable flood statistic computed from USGS stream gaging records is the 1- percent (%) chance flood; better known has the 100-year flood. By definition, this is a flood that has a 1% chance of occurring in any given year. The 1% chance flood is a statistical estimate that can be significantly influenced by length of record and extreme flood events captured in that record. Consequently, it is typically recommended that flood statistics be updated on some regular interval such as every 10 years. This paper examines the influence of record length on the 1% chance flood for the Broad River in Georgia and the substantial difference that can occur in the estimate based on record length and the hydrologic conditions under which that record was collected. 

  11. Application of flood-intensity-duration curve, rainfall-intensity-duration curve and time of concentration to analyze the pattern of storms and their corresponding floods for the natural flood events

    NASA Astrophysics Data System (ADS)

    Kim, Nam Won; Shin, Mun-Ju; Lee, Jeong Eun

    2016-04-01

    The analysis of storm effects on floods is essential step for designing hydraulic structure and flood plain. There are previous studies for analyzing the relationship between the storm patterns and peak flow, flood volume and durations for various sizes of the catchments, but they are not enough to analyze the natural storm effects on flood responses quantitatively. This study suggests a novel method of quantitative analysis using unique factors extracted from the time series of storms and floods to investigate the relationship between natural storms and their corresponding flood responses. We used a distributed rainfall-runoff model of Grid based Rainfall-runoff Model (GRM) to generate the simulated flow and areal rainfall for 50 catchments in Republic of Korea size from 5.6 km2 to 1584.2 km2, which are including overlapped dependent catchments and non-overlapped independent catchments. The parameters of the GRM model were calibrated to get the good model performances of Nash-Sutcliffe efficiency. Then Flood-Intensity-Duration Curve (FIDC) and Rainfall-Intensity-Duration Curve (RIDC) were generated by Flood-Duration-Frequency and Intensity-Duration-Frequency methods respectively using the time series of hydrographs and hyetographs. Time of concentration developed for the Korea catchments was used as a consistent measure to extract the unique factors from the FIDC and RIDC over the different size of catchments. These unique factors for the storms and floods were analyzed against the different size of catchments to investigate the natural storm effects on floods. This method can be easily used to get the intuition of the natural storm effects with various patterns on flood responses. Acknowledgement This research was supported by a grant (11-TI-C06) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

  12. A simple methodology to produce flood risk maps consistent with FEMA's base flood elevation maps: Implementation and validation over the entire contiguous United States

    NASA Astrophysics Data System (ADS)

    Goteti, G.; Kaheil, Y. H.; Katz, B. G.; Li, S.; Lohmann, D.

    2011-12-01

    In the United States, government agencies as well as the National Flood Insurance Program (NFIP) use flood inundation maps associated with the 100-year return period (base flood elevation, BFE), produced by the Federal Emergency Management Agency (FEMA), as the basis for flood insurance. A credibility check of the flood risk hydraulic models, often employed by insurance companies, is their ability to reasonably reproduce FEMA's BFE maps. We present results from the implementation of a flood modeling methodology aimed towards reproducing FEMA's BFE maps at a very fine spatial resolution using a computationally parsimonious, yet robust, hydraulic model. The hydraulic model used in this study has two components: one for simulating flooding of the river channel and adjacent floodplain, and the other for simulating flooding in the remainder of the catchment. The first component is based on a 1-D wave propagation model, while the second component is based on a 2-D diffusive wave model. The 1-D component captures the flooding from large-scale river transport (including upstream effects), while the 2-D component captures the flooding from local rainfall. The study domain consists of the contiguous United States, hydrologically subdivided into catchments averaging about 500 km2 in area, at a spatial resolution of 30 meters. Using historical daily precipitation data from the Climate Prediction Center (CPC), the precipitation associated with the 100-year return period event was computed for each catchment and was input to the hydraulic model. Flood extent from the FEMA BFE maps is reasonably replicated by the 1-D component of the model (riverine flooding). FEMA's BFE maps only represent the riverine flooding component and are unavailable for many regions of the USA. However, this modeling methodology (1-D and 2-D components together) covers the entire contiguous USA. This study is part of a larger modeling effort from Risk Management Solutions° (RMS) to estimate flood risk

  13. Gravity flows associated with flood events and carbon burial: Taiwan as instructional source area.

    PubMed

    Liu, James T; Kao, Shuh-Ji; Huh, Chih-An; Hung, Chin-Chang

    2013-01-01

    Taiwan's unique setting allows it to release disproportionately large quantities of fluvial sediment into diverse dispersal systems around the island. Earthquakes, lithology, topography, cyclone-induced rainfall, and human disturbance play major roles in the catchment dynamics. Deep landslides dominate the sediment-removal process on land, giving fluvial sediment distinct geochemical signals. Extreme conditions in river runoff, sediment load, nearshore waves and currents, and the formation of gravity flows during typhoon events can be observed within short distances. Segregation of fresh biomass and clastic sediment occurs during the marine transport process, yet turbidity currents in the Gaoping Submarine Canyon carry woody debris. Strong currents in the slope and back-arc basin of the Okinawa Trough disperse fine-grained sediments rapidly and widely. Temporal deposition and remobilization may occur when the shallow Taiwan Strait acts as a receptacle. Taiwan can therefore serve as a demonstration of the episodic aspect of the source-to-sink pathway to both the coastal and deep-ocean environments. PMID:22809183

  14. Radionuclide activities and metal concentrations in sediments of the Sebou Estuary, NW Morocco, following a flooding event.

    PubMed

    Laissaoui, A; Mas, J L; Hurtado, S; Ziad, N; Villa, M; Benmansour, M

    2013-06-01

    This study presents metal concentrations (Fe, Mg, Mn, Co, Cu, Zn, Pb, As, Sr and V) and radionuclide activities ((40)K, (137)Cs, (210)Pb, (226)Ra, (228)Ac, (234)Th and (212)Pb) in surface deposits and a sediment core from the Sebou Estuary, Northwest Morocco. Samples were collected in April 2009, about 2 months after a flooding event, and analysed using a well-type coaxial gamma-ray detector and inductively coupled plasma-quadrupole mass spectrometry. Activities of radionuclides and concentrations of almost all elements in surface samples displayed only moderate spatial variation, suggesting homogenous deposition of eroded local soil in response to intense precipitation. Excess (210)Pb displayed relatively constant activity throughout the sediment core, preventing dating and precluding determination of the historical accumulation rates of pollutants at the core site. Some elements showed non-systematic trends with depth and displayed local maxima and minima. Other elements presented relatively systematic concentration trends or relatively constant levels with discrete maxima and/or minima. Except for Mn, Sr and Cr, all metal concentrations in sediment were below levels typical of polluted systems, suggesting little human impact or losses of metals from sediment particles. PMID:23054286

  15. Origin and Dynamics of Rare Earth Elements during Flood Events in Contaminated River Basins: Sr-Nd-Pb Isotopic Evidence.

    PubMed

    Hissler, Christophe; Stille, Peter; Iffly, Jean François; Guignard, Cédric; Chabaux, François; Pfister, Laurent

    2016-05-01

    In order to precisely quantify the contribution of anthropogenic activities and geogenic sources to the dissolved and suspended loads of rivers we have combined for the first time Rare Earth Element (REE) concentrations with Sr-Nd-Pb isotope ratios. We observed enrichments in Anthropogenic Rare Earth Elements (AREE) for dissolved (Gd) and suspended (Ce and Nd) loads of river water. During flood events, AREE anomalies progressively disappeared and gave way to the geogenic chemical signature of the basin in both dissolved and suspended loads. The isotopic data confirm these observations and shed new light on the trace elements sources. On the one hand, dissolved loads have peculiar isotopic characteristics and carry mainly limestone-derived and anthropogenic Sr and Nd as well as significant amounts of anthropogenic Pb. On the other hand, the results clearly indicate that anthropogenic contributions impact the suspended loads in all hydrological conditions. This study demonstrates that anthropogenic contributions to the river may change not only Pb but also Sr and Nd isotopic compositions in both dissolved and suspended loads. This is of importance for future provenance studies. PMID:27045616

  16. Effects of riparian vegetation on topographic change during a large flood event, Rio Puerco, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Perignon, M. C.; Tucker, G. E.; Griffin, E. R.; Friedman, J. M.

    2013-09-01

    The spatial distribution of riparian vegetation can strongly influence the geomorphic evolution of dryland rivers during large floods. We present the results of an airborne lidar differencing study that quantifies the topographic change that occurred along a 12 km reach of the Lower Rio Puerco, New Mexico, during an extreme event in 2006. Extensive erosion of the channel banks took place immediately upstream of the study area, where tamarisk and sandbar willow had been removed. Within the densely vegetated study reach, we measure a net volumetric change of 578,050 ± ˜ 490,000 m3, with 88.3% of the total aggradation occurring along the floodplain and channel and 76.7% of the erosion focusing on the vertical valley walls. The sediment derived from the devegetated reach deposited within the first 3.6 km of the study area, with depth decaying exponentially with distance downstream. Elsewhere, floodplain sediments were primarily sourced from the erosion of valley walls. Superimposed on this pattern are the effects of vegetation and valley morphology on sediment transport. Sediment thickness is seen to be uniform among sandbar willows and highly variable within tamarisk groves. These reach-scale patterns of sedimentation observed in the lidar differencing likely reflect complex interactions of vegetation, flow, and sediment at the scale of patches to individual plants.

  17. High-resolution satellite turbidity and sea surface temperature observations of river plume interactions during a significant flood event

    NASA Astrophysics Data System (ADS)

    Brando, V. E.; Braga, F.; Zaggia, L.; Giardino, C.; Bresciani, M.; Matta, E.; Bellafiore, D.; Ferrarin, C.; Maicu, F.; Benetazzo, A.; Bonaldo, D.; Falcieri, F. M.; Coluccelli, A.; Russo, A.; Carniel, S.

    2015-11-01

    Sea surface temperature (SST) and turbidity (T) derived from Landsat 8 (L8) imagery were used to characterize river plumes in the northern Adriatic Sea (NAS) during a significant flood event in November 2014. Circulation patterns and sea surface salinity (SSS) from an operational coupled ocean-wave model supported the interpretation of the plumes' interaction with the receiving waters and among them. There was a good agreement of the SSS, T, and SST fields at the sub-mesoscale and mesoscale delineation of the major river plumes. L8 30 m resolution also enabled the description of smaller plume structures. The different plumes' reflectance spectra were related to the lithological fingerprint of the sediments in the river catchments. Sharp fronts in T and SST delimited each single river plume. The isotherms and turbidity isolines' coupling varied among the plumes due to differences in particle loads and surface temperatures in the discharged waters. The surface expressions of all the river plumes occurring in NAS were classified based on the occurrence of the plume dynamical regions in the L8 30 m resolution imagery.

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

    NASA Astrophysics Data System (ADS)

    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

  19. Depositional character and preservation potential of coarse-grained sediments deposited by flood events in hyper-arid braided channels in the Rift Valley, Arava, Israel

    NASA Astrophysics Data System (ADS)

    Laronne, Jonathan B.; Shlomi, Yanai

    2007-02-01

    Four coarse-grained braided channels undergoing rapid deposition in the hyper-arid Arava Rift Valley have been studied to determine the dynamics of strata deposition by monitored flood events and to ascertain the sedimentologic character of these event deposits. The systems span granule-sand to sandy-gravel bed material having longitudinal bars with simultaneously increasing grains size, slope and bed relief. Scour and fill were monitored along cross-sections using scour chains and repeat surveys, while event strata (=fill) were described with reference to sediment calibre, type of support, grading, thickness and location. Unlike many previous investigations of gravel sedimentology, the source of information for this study involves not only stratigraphic description but also observation of the concomitant dynamics of the channel bed as expressed by the extent of event deposition. The texture of the deposited sediment generally coarsens in sympathy with the surface bed texture of the studied channels. The thickness of event-deposited sediments increases as the magnitude of flow events increases. The stratigraphic record is characterized by: (1) sub-parallel stratification, (2) no grading, (3) clast-supported gravel infilled with sand-granule matrices and (4) rapid sedimentation rates. This character is hypothesized to mirror the elevated bedload fluxes in this hyper-arid fluvial setting. Lacking densely-vegetated banks, the proximal braidplain of this arid environment often contains no extensive fine-textured floodplain successions. The depth of fill as well as the extent of strata obliteration increase with flood magnitude, explaining the increased preservation potential of event strata with increase in flood magnitude. It also explains why most event strata, including large ones, are only partially preserved.

  20. An expeditious risk analysis of intense rainfall events in low mountain ranges of Central German Uplands under the aspect of a sustainable and decentralised flood retention

    NASA Astrophysics Data System (ADS)

    Bertermann, D.; Bialas, C.; Zacherl, A.

    2012-04-01

    Due to increasing settlement pressure, intensifying pressure as a result of the utilisation of flood-threatened surfaces and also in consequence of the climate change with its effects even on local scales an accumulation of flood events is to be expected. Areas that have not been influenced by flood events in the past, like low mountain ranges, can certainly be affected in the near future. Against this background applicable solution and adjustment strategies are required in practice to mitigate such events or to even prevent them. The key aim of the research activities is the development of a standardised and expeditious risk analysis of intense rainfall events in low mountain ranges of Central German Uplands under the aspect of sustainable and decentralised flood retention and protection. Hydrologic characteristics, expressed by the 'run-off-coefficient' and the 'surface roughness', for clearly defined biotope types of German low mountain ranges should be derived with the help of already existing standardised soil/utilisation/vegetation units. According to the current state-of-the-art of flood models land use changes do not have great impact on the slow-flowing, large flood events in widespread watersheds. On the contrary, small, swift-flowing floods in small watersheds can be influenced by land use or management changes. Thus, the focus of the research work is aimed on these small quick flood events. However, also differentiated information for the solution of flood problems in large watersheds can be reached by the summation of statements about small watersheds. The development of a standardised planning method (incl. the GI-System implementation) for the optimization of the drain regulation serves for the reduction of the flood danger. Land use and vegetation is so optimised in adaptation to soil and land management and by taking into account prevailing drain roads that an essential contribution to the regulation of the surface run-off can be performed. The

  1. Flooding and Flood Management

    USGS Publications Warehouse

    Brooks, K.N.; Fallon, J.D.; Lorenz, D.L.; Stark, J.R.; Menard, Jason

    2011-01-01

    Floods result in great human disasters globally and nationally, causing an average of $4 billion of damages each year in the United States. Minnesota has its share of floods and flood damages, and the state has awarded nearly $278 million to local units of government for flood mitigation projects through its Flood Hazard Mitigation Grant Program. Since 1995, flood mitigation in the Red River Valley has exceeded $146 million. Considerable local and state funding has been provided to manage and mitigate problems of excess stormwater in urban areas, flooding of farmlands, and flood damages at road crossings. The cumulative costs involved with floods and flood mitigation in Minnesota are not known precisely, but it is safe to conclude that flood mitigation is a costly business. This chapter begins with a description of floods in Minneosta to provide examples and contrasts across the state. Background material is presented to provide a basic understanding of floods and flood processes, predication, and management and mitigation. Methods of analyzing and characterizing floods are presented because they affect how we respond to flooding and can influence relevant practices. The understanding and perceptions of floods and flooding commonly differ among those who work in flood forecasting, flood protection, or water resource mamnagement and citizens and businesses affected by floods. These differences can become magnified following a major flood, pointing to the need for better understanding of flooding as well as common language to describe flood risks and the uncertainty associated with determining such risks. Expectations of accurate and timely flood forecasts and our ability to control floods do not always match reality. Striving for clarity is important in formulating policies that can help avoid recurring flood damages and costs.

  2. 1,100 years after an earthquake: modification of the earthquake record by submergence, Puget Lowland, Washington State

    NASA Astrophysics Data System (ADS)

    Arcos, M. E.

    2011-12-01

    Crustal faults may pose a complicated story for earthquake reconstruction. In some cases, regional tectonic strain overprints the record of coseismic land-level changes. This study looks at the record of earthquakes at two sites in the Puget Lowland, Gorst and the Skokomish delta, and how post-earthquake submergence modified the paleoseismic records. The Puget Lowland is the slowly subsiding forearc basin of the northern Cascadia subduction zone. A series of active thrust faults cross this lowland. Several of these faults generated large (M7+) earthquakes, about 1,100 years ago and both field sites have submerged at least 1.5 m since that time. This submergence masked the geomorphic record of uplift in some areas, resulting in a misreading of the zone of earthquake deformation and potential misinterpretation of the underlying fault structure. Earthquakes ~1,100 years ago uplifted both field localities and altered river dynamics. At Gorst, a tsunami and debris flow accompanied uplift of at least 3 m by the Seattle fault. The increased sediment load resulted in braided stream formation for a period after the earthquake. At the Skokomish delta, differential uplift trapped the river on the eastern side of the delta for the last 1,100 years resulting in an asymmetric intertidal zone, 2-km wider on one side of the delta than the other. The delta slope or submergence may contribute to high rates of flooding on the Skokomish River. Preliminary results show the millennial scale rates of submergence vary with the southern Puget Lowland submerging at a faster rate than the northern Puget Lowland. This submergence complicates the reconstruction of past earthquakes and renders assessment of future hazards difficult for those areas that are based on uplifted marine platforms and other coastal earthquake signatures in several ways. 1) Post-earthquake submergence reduces the apparent uplift of marine terraces. 2) Submergence makes zones of earthquake deformation appear narrower. 3

  3. An Intensive Post Event Campaign (IPEC) on the extreme flash flood which affected the Starzel river (Germany) on the 2nd of June 2008

    NASA Astrophysics Data System (ADS)

    Gaume, E.

    2009-04-01

    On the 2nd of June 2008 in the evening, the Zollernabkreis region, located 50 kilometers South from Stuttgart (Germany), was affected by extreme thunderstorms which induced large flash floods. The most severely affected area appeared to be the upper Starzel river catchment (130 km2) where the extraordinary flood caused large damages in two towns (Hechingen and Jungingen) and killed 3 people. The data collected immediately after the flood event are impressive: 75 mm of rainfall accumulated within 1 hour near Hechingen and up to 240 mm within 55 minutes measured on a private gauge in the town of Jungingen. These first elements led to the organization of an intensive post event campaign (IPEC) with two objectives: 1) to validate and complement the existing data on rainfall and runoff, 2) to analyze the dominant rainfall-runoff processes during such an extreme event. The field campaign took place in November 2008 and involved 11 scientists from various European research institutions contributing to the European research project Hydrate as well as hydrologists from the regional administration. 36 river cross-sections were surveyed in the affected watershed to map the discharges; detailed accounts of the flood in Jungingen as well as films and pictures were collected to establish the timing of the flood; and the available radar, rainfall and stream gauge measurements were verified. The main outcomes of this IPEC are the following: • The discharge mapping revealed very high spatial heterogeneities. The flood volumes were essentially produced on a very limited part of the catchment area: a 5 km2 area upstream Jungingen and about 10 km2 area for the whole Starzel watershed. • In this area, very high unit discharges were estimated - between 12 and 15 m3/s/km2. These values imply surprisingly low runoff rates (about 20%) according to the estimated rainfall intensities - which were validated during the field survey. • Such localized intense events do not appear to be

  4. Innovation and Involvement: 100 Years of Community Work with Older People.

    ERIC Educational Resources Information Center

    Glasby, Jon

    2000-01-01

    Birmingham Settlement has provided services to British older adults for over 100 years, including such innovations as adult day centers, meals on wheels, and transportation services. The participation of the clientele in research helped flesh out the history of the settlement through narratives that demonstrate its impact on the life of the…

  5. 100 Years of Cotton Production, Harvesting and Ginning Systems Engineering: 1907 - 2007

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The American Society of Agricultural and Biological Engineers (ASABE) celebrated its centennial year during 2007. As part of the ASABE centennial, the authors were asked to describe agricultural engineering accomplishments in U.S. cotton production, harvesting and ginning over the past 100 years. ...

  6. What Would You Look Like If You Were 100 Years Old?

    ERIC Educational Resources Information Center

    Petersen, Hugh

    1998-01-01

    Describes a project inspired by the 100th day of school in which first-grade students created a self-portrait of themselves at 100 years old and wrote an accompanying essay. States that the students drew wrinkles on the faces, age-appropriate clothing, gray or white hair, and even glasses as a finishing touch. (CMK)

  7. The life and times of the LED - a 100-year history

    NASA Astrophysics Data System (ADS)

    Zheludev, Nikolay

    2007-04-01

    Many people believe that the LED was discovered by US researchers working in the 1960s. In fact, Henry Round at Marconi Labs noted the emission of light from a semiconductor diode 100 years ago and, independently, a forgotten Russian genius - Oleg Losev - discovered the LED.

  8. A user-friendly database of coastal flooding in the United Kingdom from 1915-2014.

    PubMed

    Haigh, Ivan D; Wadey, Matthew P; Gallop, Shari L; Loehr, Heiko; Nicholls, Robert J; Horsburgh, Kevin; Brown, Jennifer M; Bradshaw, Elizabeth

    2015-01-01

    Coastal flooding caused by extreme sea levels can be devastating, with long-lasting and diverse consequences. Historically, the UK has suffered major flooding events, and at present 2.5 million properties and £150 billion of assets are potentially exposed to coastal flooding. However, no formal system is in place to catalogue which storms and high sea level events progress to coastal flooding. Furthermore, information on the extent of flooding and associated damages is not systematically documented nationwide. Here we present a database and online tool called 'SurgeWatch', which provides a systematic UK-wide record of high sea level and coastal flood events over the last 100 years (1915-2014). Using records from the National Tide Gauge Network, with a dataset of exceedance probabilities and meteorological fields, SurgeWatch captures information of 96 storms during this period, the highest sea levels they produced, and the occurrence and severity of coastal flooding. The data are presented to be easily assessable and understandable to a range of users including, scientists, coastal engineers, managers and planners and concerned citizens. PMID:25984352

  9. A user-friendly database of coastal flooding in the United Kingdom from 1915–2014

    PubMed Central

    Haigh, Ivan D.; Wadey, Matthew P.; Gallop, Shari L.; Loehr, Heiko; Nicholls, Robert J.; Horsburgh, Kevin; Brown, Jennifer M.; Bradshaw, Elizabeth

    2015-01-01

    Coastal flooding caused by extreme sea levels can be devastating, with long-lasting and diverse consequences. Historically, the UK has suffered major flooding events, and at present 2.5 million properties and £150 billion of assets are potentially exposed to coastal flooding. However, no formal system is in place to catalogue which storms and high sea level events progress to coastal flooding. Furthermore, information on the extent of flooding and associated damages is not systematically documented nationwide. Here we present a database and online tool called ‘SurgeWatch’, which provides a systematic UK-wide record of high sea level and coastal flood events over the last 100 years (1915-2014). Using records from the National Tide Gauge Network, with a dataset of exceedance probabilities and meteorological fields, SurgeWatch captures information of 96 storms during this period, the highest sea levels they produced, and the occurrence and severity of coastal flooding. The data are presented to be easily assessable and understandable to a range of users including, scientists, coastal engineers, managers and planners and concerned citizens. PMID:25984352

  10. Past and future flooding in Bangladesh

    NASA Astrophysics Data System (ADS)

    Thiele-Eich, Insa; Hopson, Thomas; Simmer, Clemens; Simon, Thorsten

    2016-04-01

    Currently, an average of about 20 % of the land surface in Bangladesh is flooded each year, affecting one of the most densely populated regions in the world. We aim to understand the processes currently determining flooding in the Ganges-Brahmaputra-Meghna (GBM) basin, in particular the role of precipitation and sea-level rise, as well as to assess how climate change might impact flood characteristics in the future. Water level and discharge data were provided by the Bangladesh Water Development Board on a daily basis for a period of 1909-2009. Monthly maps based on daily sea level anomalies from the Data Unification Altimeter Combination System DUACS are available on a 0.25° by 0.25° grid for the time period 1993-2014. Ensemble model output for upper catchment precipitation and annual mean thermosteric sea-level rise is taken from historical and RCP scenario runs conducted with the CCSM4. We first analyzed daily water levels of the past 100 years in order to detect potential shifts in extremes. The available observations are then used to set up a generalized linear model to detect how precipitation influences flooding in the GBM basin. This model can then be used to give a prognosis on changes in future flooding. Our analysis suggests that water levels have indeed changed over the course of the past century. While the magnitude and duration of average flood events decreased, the frequency of extreme flood events has increased. Low water levels have also changed, with a significant decrease in the annual minimum water level most noticeable when we compare the time periods 1909-1939 and 1979-2009. For the future, first results confirm the decrease in return periods of strong flood events found in previous studies. The impact of climate change on flooding will also be compared to the impact of man-made structures such as Farakka barrage, built across the Ganges on the border between India and Bangladesh and operating since 1975. This is of particular interest as

  11. Meltwater flooding events in the Gulf of Mexico revisited: Implications for rapid climate changes during the last deglaciation

    NASA Astrophysics Data System (ADS)

    Aharon, Paul

    2003-12-01

    North American freshwater runoff records have been used to support the case that climate flickers were caused by shutdowns of the ocean thermohaline circulation (THC) resulting from reversals of meltwater discharges. Inconsistencies in the documentation of these meltwater switches, however, continue to fuel the debate on the cause/s of the oscillatory nature of the deglacial climate. New oxygen and carbon isotope records from the northern Gulf of Mexico depict in exceptional detail the succession of meltwater floods and pauses through the southern routing during the interval 16 to 8.9 ka (14C years BP; ka, kiloannum). The records underscore the bimodal role played by the Gulf of Mexico as a destination of meltwater discharges from the receding Laurentide Ice Sheet. The evidence indicates that the Gulf of Mexico acted as the principal source of superfloods at 13.4, 12.6, and 11.9 ka that reached the North Atlantic and contributed significantly to density stratification, disruption of ocean ventilation, and cold reversals. Gulf of Mexico lapsed into a "relief valve" position in post-Younger Dryas time, when meltwater discharges were rerouted south at 9.9, 9.7, 9.4, and 9.1 ka, thus temporarily interrupting North Atlantic-bound freshwater discharges from Lake Agassiz. The history of meltwater events in the Gulf of Mexico contradicts the model that meltwater flow via the eastern outlets into the North Atlantic disrupted the ocean THC, causing cooling, while diversions to the Gulf of Mexico via the Mississippi River enhanced THC and warming.

  12. The influence of high magnitude/ low frequency flood events on the spawning habitat of Atlantic salmon in the headwaters of a Scottish stream.

    NASA Astrophysics Data System (ADS)

    Moir, H.; Gibbins, C.; Soulsby, C.; Webb, J.

    2002-12-01

    In upland salmonid spawning streams, a large proportion of sediment supply is generated in steep headwater reaches during low frequency, high magnitude flood events. These events are integral in dictating channel morphology in these streams. Previous work on a number of Scottish upland streams has suggested that material introduced to the channel during these events is the dominant source of salmonid spawning-calibre sediment and, being important in dictating channel morphology through-out the system, key in controlling the distribution of fish habitats. In headwater reaches, salmonid spawning habitat tends to be limited by the quantity and distribution of suitable sediments, the hydraulics of such locations tending to transport gravel-sized material downstream. Data collected on the Allt a' Ghlinne Bhig (an upland tributary of the River Tay, Scotland) has shown that headwater accumulations of gravel as a result of episodic sediment input during large flood events can provide important spawning habitat, although such features are intrinsically unstable. Uptake of these habitats may be disproportionately important to juvenile production. The stream morphology and discharge associated with over 400 incidents of Atlantic salmon spawning were recorded over three consecutive seasons (2000, 2001 and 2002). Two high magnitude flood events in September 2001 and July 2002 resulted in major sediment input to the headwaters, heavily modifying the character of the channel and producing many substantial accumulations of gravel. In the season prior to these events (2000), no spawning was observed in these locations. During the subsequent surveys (2001 and 2002), a significant number of spawning incidents were observed in the headwaters, potentially providing stock to uptake habitat in these important headwater areas. Although stream discharge during the spawning period is known to affect access to headwater reaches, flows between the three study periods were not significantly

  13. Drought, floods and water quality: Drivers of a severe hypoxic blackwater event in a major river system (the southern Murray-Darling Basin, Australia)

    NASA Astrophysics Data System (ADS)

    Whitworth, Kerry L.; Baldwin, Darren S.; Kerr, Janice L.

    2012-07-01

    SummaryHypoxic blackwater events are characterised by high levels of dissolved organic carbon in the water column, the metabolism of which depletes dissolved oxygen, which can cause fish and crustacean mortality. Understanding the drivers of and controls on hypoxic blackwater events is important in order to reduce the potential for detrimental water quality impacts from both managed and natural flows. After a decade-long drought in south-eastern Australia, a series of spring and summer flood events in 2010-2011 resulted in a large-scale hypoxic blackwater event in the southern Murray-Darling Basin that affected over 2000 km of river channels and persisted for 6 months. We examined the biogeochemistry and hydrology underpinning this extreme event and found that multiple drivers contributed to the development and persistence of hypoxic blackwater. Inundation of both forested and agricultural floodplains that had not been flooded for over a decade mobilised large stores of reactive carbon. Altered flow seasonality, due to a combination of climatic effects and river regulation, not only increased the risk of hypoxic blackwater generation but also shifted the proportion of bioavailable carbon that was returned to the river channels. Hypolimnetic weir discharge also contributed to hypoxia at some sites. These findings highlight the need for a whole-of-system perspective for the management of regulated river systems - especially in the face of a changing climate.

  14. Iceland Dust Storms Linked to Glacial Outwash Deposits and to Sub-Glacial Flood (Jökulhlaup) Events

    NASA Astrophysics Data System (ADS)

    Prospero, J. M.; Arnalds, Ó.; Olafsson, H.; Bullard, J.; Hodgkins, R.

    2008-12-01

    Studies of Arctic snow and ice cores reveal large temporal changes in dust concentrations, especially over glacial-interglacial cycles. Most efforts to model dust variability with climate have focused on sources in tropical and mid-latitude arid regions and have neglected high latitude emissions because of a lack of information on possible sources. Here we report on aerosol measurements which show that dust storms are common on Iceland and that major events are associated with glacial sedimentary environments. In July 1991 we established an aerosol sampling site on Heimaey, a small island located 18 km off the southeast coast of Iceland, with the objective of studying the transport of pollutant species to the Arctic. We found that although concentrations of nitrate and non-sea-salt sulfate were generally quite low, there were sporadic peaks that were primarily attributed to pollutant transport from Europe [Prospero et al., 1995]. Recently we expanded our analyses to include mineral dust, covering the period 1997 through 2004. Dust is present during much of the year (annual average 3.9 μg m-3) with a strong seasonal cycle (maximum in April, 14.0 μg m-3). However there are many spikes in the dust record, some exceeding 100 μg m-3, which are not associated with pollutant transport peaks. A search of NASA satellite web archives yielded six "dust storm" images that were acquired during our data period. These show prominent dust plumes streaming off the coast of Iceland. Here we show that each image could be closely linked to a major dust peak in our record (although there were many more peaks than satellite images). Most of these dust events were associated with dust emitted from glacial outwash (sandur) deposits. Some of the largest dust peaks were linked to jökulhlaups, an Icelandic term for sub-glacially generated outburst floods. The dust clouds were typically comprised of a series of well-defined plumes emitted from large "point" sources, mostly associated with

  15. The influence of the maintenance of terraced areas on slope stability during the November 2014 flood event in Liguria (northwestern Italy)

    NASA Astrophysics Data System (ADS)

    Giordan, Daniele; Poggi, Flavio; Baldo, Marco; Cignetti, Martina

    2016-04-01

    Terraced environments are a widespread feature of the coastal settlement of eastern Liguria (northwestern Italy) and they constitute a well-known favorable role in slope stability. In this region, starting from the twentieth century, the progressive abandonment of agriculture determines a progressively increasing lack of maintenance of the terraces, consequently raising the level of slope instability. Moreover, it should be taken into account not only the level of terraces maintenance, but also their interaction with several factors as i) geological and geomorphological conditions, ii) soil properties, iii) hydrological and hydrogeological conditions, and iv) land use, causing an increase in landslides occurrence. The definition of managed terraces effects on slope stability and their response to external stress like a flood event is rather complicated; a possible approach is a statistical analysis of the effects of a flood event over a large terraced area, distinguishing the maintained sectors from the abandoned ones. After the November 2014 flood event, which affected several sectors of the Liguria region, where a high number of shallow landslides were triggered, an airborne LiDAR survey of the damaged area was carried out. In particular, a high resolution Digital Terrain Model (DTM) resampled to a lower density (1 square meter grid spacing) and a photogrammetric coverage of the area was performed, in order to create a landslide map of the flood event. The surveyed area covered more than 380 square kilometers, and over 1600 shallow landslides triggered by the flood event were identified and inventoried. The high resolution DTM allowed the identification of terraced areas also in wooded sectors and a sharp mapping of the extension of terraced slopes in this portion of Liguria region. By considering: i) the terraced areas recognized through DTM analysis, ii) the mapped landslides, and iii) the land use classification, a correlation between the presence of terraces

  16. A Southern Alps and Northern Pyrenees Holocene record of snowmelt-induced flood events and clastic layers associated with negative NAO phases in Western Europe

    NASA Astrophysics Data System (ADS)

    Simonneau, Anaëlle; Chapron, Emmanuel; Galop, Didier; Tachikawa, Kazuyo; Magny, Michel; Bard, Edouard

    2014-05-01

    The origin of both extreme flood events in Lake Ledro (southern Italian Alps) and coarse sandy layers in two disconnected lakes from the Bassies valley (Lakes Majeur and Sigriou, northern Pyrenees) have been related to the impact of snowmelt processes enhancing erosion of mountainous drainage basins (1, 2) throughout the Holocene. Because of increasing human impact on catchment erosion processes since the mid-Holocene in these western European mountain ranges, this study compares these well-dated lacustrine sequences in order to further document the influence of westerlies and of the North Atlantic Oscillation on clastic supply in contrasted lake basins. The integrative approaches performed on each site allow us to show that organic and minerogenic markers, such as non-pollen microsfossils, Rock-Eval pyrolysis or X-ray microfluorescence, are powerful tools to identify clastic sediment source areas. At Ledro, we therefore demonstrated that over the Late Holocene snowmelt-induced flood events essentially remobilized high altitude pasture areas whereas afterwards the flood events affected former forested areas from lower altitude1. In the Pyrenees, the southern slopes of lakes Majeur and Sigriou are characterized by two narrow canyons whose drainage basins are disconnected, relatively small and limited to the high altitude part of the valley of Bassiès. Our results demonstrated that the mid-late Holocene period was regularly interrupted by coarse sandy layers affecting both lakes Majeur and Sigriou and reflecting the high sensitivity of the two active canyons to intense rainfall or snowmelt periods². While extreme flood deposits in Lake Ledro during the Bronze Age period may result from the combination of both climate and human activities, contemporaneous extreme flood events in Ledro and coarse sandy layers in the Bassiès lakes, dated to AD 1710, AD1530, AD1360, AD940, AD570 and 1850, 1050, 1410, 1850, 2690, 4190, 4800 cal BP, testify of regional hydrological

  17. Creating Long Term Income Streams for the 100 Year Starship Study Initiative

    NASA Astrophysics Data System (ADS)

    Sylvester, A. J.

    Development and execution of long term research projects are very dependent on a consistent application of funding to maximize the potential for success. The business structure for the 100 Year Starship Study project should allow for multiple income streams to cover the expenses of the research objectives. The following examples illustrate the range of potential avenues: 1) affiliation with a charitable foundation for creating a donation program to fund a long term endowment for research, 2) application for grants to fund initial research projects and establish the core expertise of the research entity, 3) development of intellectual property which can then be licensed for additional revenue, 4) creation of spinout companies with equity positions retained by the lab for funding the endowment, and 5) funded research which is dual use for the technology goals of the interstellar flight research objectives. With the establishment of a diversified stream of funding options, then the endowment can be funded at a level to permit dedicated research on the interstellar flight topics. This paper will focus on the strategy of creating spinout companies to create income streams which would fund the endowment of the 100 Year Starship Study effort. This technique is widely used by universities seeking to commercially develop and market technologies developed by university researchers. An approach will be outlined for applying this technique to potentially marketable technologies generated as a part of the 100 Year Starship Study effort.

  18. Flood risk assessment and mapping for the Lebanese watersheds

    NASA Astrophysics Data System (ADS)

    Abdallah, Chadi; Hdeib, Rouya

    2016-04-01

    Of all natural disasters, floods affect the greatest number of people worldwide and have the greatest potential to cause damage. Nowadays, with the emerging global warming phenomenon, this number is expected to increase. The Eastern Mediterranean area, including Lebanon (10452 Km2, 4.5 M habitant), has witnessed in the past few decades an increase frequency of flooding events. This study profoundly assess the flood risk over Lebanon covering all the 17 major watersheds and a number of small sub-catchments. It evaluate the physical direct tangible damages caused by floods. The risk assessment and evaluation process was carried out over three stages; i) Evaluating Assets at Risk, where the areas and assets vulnerable to flooding are identified, ii) Vulnerability Assessment, where the causes of vulnerability are assessed and the value of the assets are provided, iii) Risk Assessment, where damage functions are established and the consequent damages of flooding are estimated. A detailed Land CoverUse map was prepared at a scale of 1/ 1 000 using 0.4 m resolution satellite images within the flood hazard zones. The detailed field verification enabled to allocate and characterize all elements at risk, identify hotspots, interview local witnesses, and to correlate and calibrate previous flood damages with the utilized models. All filed gathered information was collected through Mobile Application and transformed to be standardized and classified under GIS environment. Consequently; the general damage evaluation and risk maps at different flood recurrence periods (10, 50, 100 years) were established. Major results showed that floods in a winter season (December, January, and February) of 10 year recurrence and of water retention ranging from 1 to 3 days can cause total damages (losses) that reach 1.14 M for crop lands and 2.30 M for green houses. Whereas, it may cause 0.2 M to losses in fruit trees for a flood retention ranging from 3 to 5 days. These numbers differs

  19. 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.

    PubMed

    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. PMID

  20. 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

    PubMed Central

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Time needed to evacuate the Netherlands in the event of large-scale flooding: strategies and consequences.

    PubMed

    Kolen, Bas; Helsloot, Ira

    2012-10-01

    On 30 May 2008, the Government of the Netherlands informed the national parliament about the effectiveness of preventive evacuation of coastal and river areas in case of flooding. Analysis of a case study showed that it is impossible to evacuate coastal areas preventively within a 48-hour time span preceding a worst credible scenario flood caused by a storm surge. This fact illustrates the need for alternative evacuation strategies, such as vertical evacuation (evacuating to safe havens, inside the flood zone) or shelter-in-place (hiding), to reduce loss of life and the impact of the evacuation. This paper defines these strategies and demonstrates, by returning to the case study used by the Dutch government, that they require different measures, methods of approach, and crisis management processes. In addition, it addresses the need for flexible and scalable preparation so that after detecting and understanding the threat, authorities and citizens can make decisions about different evacuation strategies. PMID:22356553

  3. Thirty Years Later: Reflections of the Big Thompson Flood, Colorado, 1976 to 2006

    NASA Astrophysics Data System (ADS)

    Jarrett, R. D.; Costa, J. E.; Brunstein, F. C.; Quesenberry, C. A.; Vandas, S. J.; Capesius, J. P.; O'Neill, G. B.

    2006-12-01

    . When substantial flooding occurs, the USGS mobilizes personnel to collect streamflow data in affected areas. Streamflow data improve flood forecasting and provide data for flood-frequency analysis for floodplain management, design of structures located in floodplains, and related water studies. An important lesson learned is that nature provides environmental signs before and during floods that can help people avoid hazard areas. Important contributions to flood science as a result of the 1976 flood include development of paleoflood methods to interpret the preserved flood-plain stratigraphy to document the number, magnitude, and age of floods that occurred prior to streamflow monitoring. These methods and data on large floods can be used in many mountain-river systems to help us better understand flood hazards and plan for the future. For example, according to conventional flood-frequency analysis, the 1976 Big Thompson flood had a flood recurrence interval of about 100 years. However, paleoflood research indicated the 1976 flood was the largest in about the last 10,000 years in the basin and had a flood recurrence interval in excess of 1,000 years.

  4. What if the 25 October 2011 event that struck Cinque Terre (Liguria) had happened in Genoa, Italy? Flooding scenarios, hazard mapping and damage estimation

    NASA Astrophysics Data System (ADS)

    Silvestro, Francesco; Rebora, Nicola; Rossi, Lauro; Dolia, Daniele; Gabellani, Simone; Pignone, Flavio; Trasforini, Eva; Rudari, Roberto; De Angeli, Silvia; Masciulli, Cristiano

    2016-08-01

    During the autumn of 2011 two catastrophic, very intense rainfall events affected two different parts of the Liguria Region of Italy causing various flash floods. The first occurred in October and the second at the beginning of November. Both the events were characterized by very high rainfall intensities (> 100 mm h-1) that persisted on a small portion of territory causing local huge rainfall accumulations (> 400 mm 6 h-1). Two main considerations were made in order to set up this work. The first consideration is that various studies demonstrated that the two events had a similar genesis and similar triggering elements. The second very evident and coarse concern is that two main elements are needed to have a flash flood: a very intense and localized rainfall event and a catchment (or a group of catchments) to be affected. Starting from these assumptions we did the exercise of mixing the two flash flood ingredients by putting the rainfall field of the first event on the main catchment struck by the second event, which has its mouth in the biggest city of the Liguria Region: Genoa. A complete framework was set up to quantitatively carry out a "what if" experiment with the aim of evaluating the possible damages associated with this event. A probabilistic rainfall downscaling model was used to generate possible rainfall scenarios maintaining the main characteristics of the observed rainfall fields while a hydrological model transformed these rainfall scenarios in streamflow scenarios. A subset of streamflow scenarios is then used as input to a 2-D hydraulic model to estimate the hazard maps, and finally a proper methodology is applied for damage estimation. This leads to the estimation of the potential economic losses and of the risk level for the people that stay in the affected area. The results are interesting, surprising and in a way worrying: a rare but not impossible event (it occurred about 50 km away from Genoa) would have caused huge damages estimated between

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

    NASA Astrophysics Data System (ADS)

    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

  6. Spatial-temporal variations of dominant drought/flood modes and the associated atmospheric circulation and ocean events in rainy season over the east of China

    NASA Astrophysics Data System (ADS)

    Huang, Shaoni; Huang, Fei

    2012-06-01

    By using Season-reliant Empirical Orthogonal Function (S-EOF) analysis, three dominant modes of the spatial-temporal evolution of the drought/flood patterns in the rainy season over the east of China are revealed for the period of 1960-2004. The first two leading modes occur during the turnabout phase of El Niño-Southern Oscillation (ENSO) decaying year, but the drought/flood patterns in the rainy season over the east of China are different due to the role of the Indian Ocean (IO). The first leading mode appears closely correlated with the ENSO events. In the decaying year of El Niño, the associated western North Pacific (WNP) anticyclone located over the Philippine Sea persists from the previous winter to the next early summer, transports warm and moist air toward the southern Yangtze River in China, and leads to wet conditions over this entire region. Therefore, the precipitation anomaly in summer exhibits a `Southern Flood and Northern Drought' pattern over East China. On the other hand, the basin-wide Indian Ocean sea surface temperature anomaly (SSTA) plays a crucial role in prolonging the impact of ENSO on the second mode during the ENSO decaying summer. The Indian Ocean basin mode (IOBM) warming persists through summer and unleashes its influence, which forces a Matsuno-Gill pattern in the upper troposphere. Over the subtropical western North Pacific, an anomalous anticyclone forms in the lower troposphere. The southerlies on the northwest flank of this anticyclone increase the moisture transport onto central China, leading to abundant rainfall over the middle and lower reaches of the Yangtze River and Huaihe River valleys. The anomalous anticyclone causes dry conditions over South China and the South China Sea (SCS). The precipitation anomaly in summer exhibits a `Northern Flood and Southern Drought' pattern over East China. Therefore, besides the ENSO event the IOBM is an important factor to influence the drought/flood patterns in the rainy season over

  7. 100 years since the discovery of cosmic rays. A brief history

    NASA Astrophysics Data System (ADS)

    Chiavassa, Andrea

    2012-11-01

    With the words "Cosmic Rays" we mean particles impinging on the earth atmosphere. The existence of these particles was discovered in 1912, i.e. exactly 100 years ago, by the Austrian physicist Victor Hesss. In this contribution I will describe the steps that lead to such a discovery: from the electroscope measurements, showing their spontaneous discharge, to the correct explanation of this results with the existence of charged particles arriving from outside of the atmosphere. Then I will discuss the first steps of experimental particle physics, obtained with experiments performed detecting cosmic rays, that allowed important discoveries as the detection of antimatter and of new subatominc particles as muons and pions.

  8. Insights from analyzing and modelling cascading multi-lake outburst flood events in the Santa Cruz Valley (Cordillera Blanca, Perú)

    NASA Astrophysics Data System (ADS)

    Emmer, Adam; Mergili, Martin; Juřicová, Anna; Cochachin, Alejo; Huggel, Christian

    2016-04-01

    Since the end of Little Ice Age, the Cordillera Blanca of Perú has experienced tens of lake outburst floods (LOFs), resulting in the loss of thousands of lives and significant material damages. Most commonly involving glacial lakes, such events are often directly or indirectly related to glacier retreat. Here we analyze an event on 8th February 2012 involving four lakes and affecting two valleys (Santa Cruz and Artizón) in the northern part of the Cordillera Blanca. Using the combination of field data, satellite images, digital elevation model (DEM) and GIS-based modelling approaches, the main objectives are: (i) to better understand complex multi-lake outburst flood and related foregoing and induced geomorphological processes; and (ii) to evaluate and discuss the suitability, potentials and limitations of the r.avaflow model for modelling such complex process chains. Analyzing field geomorphological evidence and remotely-sensed images, we reconstruct the event as follows: a landslide from the recently deglaciated left lateral moraine of Lake Artizón Alto (4 639 m a.s.l.), characterized by steep slopes and a height of more than 200 m produced a displacement wave which overtopped the bedrock dam of the lake. The resulting flood wave breached the dam of the downstream moraine-/landslide-dammed Lake Artizón Bajo (4 477 m a.s.l.), decreasing the lake level by 10 m and releasing 3 x 105 m3 of water. Significant amounts of material were eroded from the steeper parts of the Artizón Valley (mean slope >15°) and deposited further downstream in the flatter part of the Santa Cruz Valley (mean slope <2°; confluence of the two valleys at 3 985 m a.s.l.). The flood affected two debris cone-dammed lakes (Jatuncocha and Ichiccocha) in the Santa Cruz Valley. Some minor damages to the dam of Lake Jatuncocha were documented. Geomprohological evidence of the event was observed more than 20 km downstream from Lake Artizón Alto. The described multi-LOF event was employed as a

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

    PubMed Central

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

    2015-01-01

    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. PMID:25648177

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

    PubMed

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

    2015-02-01

    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. PMID:25648177

  11. Magnitude and frequency of peak discharges for Mississippi River Basin Flood of 1993

    USGS Publications Warehouse

    Thomas, W.O., Jr.; Eash, D.A.

    1995-01-01

    The magnitude and frequency of the 1993 peak discharges in the upper Mississippi River Basin are characterized by applying Bulletin 17B and L-moment methods to annual peak discharges at 115 unregulated watersheds in the basin. The analysis indicated that the 1993 flood was primarily a 50-year or less event on unregulated watersheds less than about 50,000 km2 (20,000 mi2). Of the 115 stations analyzed, the Bulletin 17B and L-moment methods were used to identify 89 and 84 stations, respectively, having recurrence intervals of 50 years or less, and 31 and 26 stations, respectively, having recurrence intervals greater than 50 years for the 1993 peak discharges. The 1993 flood in the upper Mississippi River Basin was significant in terms of (a) peak discharges with recurrence intervals greater than 50 years at approximately 25 percent of the stations analyzed, (b) peak discharges of record at 33 of the 115 stations analyzed, (c) extreme magnitude, duration, and areal extent of precipitation, (d) flood volumes with recurrence intervals greater than 100 years at many stations, and (e) extreme flood damage and loss of lives. Furthermore, peak discharges on several larger, regulated watersheds also exceeded the 100-year recurrence interval. However, for about 75 percent of the 115 unregulated stations in the analysis, the frequency of the 1993 peak discharges was less than a 50-year event.

  12. Morphological response of songbirds to 100 years of landscape change in North America.

    PubMed

    Desrochers, A

    2010-06-01

    Major landscape changes caused by humans may create strong selection pressures and induce rapid evolution in natural populations. In the last 100 years, eastern North America has experienced extensive clear-cutting in boreal areas, while afforestation has occurred in most temperate areas. Based on museum specimens, I show that wings of several boreal forest songbirds and temperate songbirds of non-forest habitats have become more pointed over the last 100 years. In contrast, wings of most temperate forest and early-successional boreal forests species have become less pointed over the same period. In contrast to wing shape, the bill length of most species did not change significantly through time. These results are consistent with the "habitat isolation hypothesis", i.e., songbirds evolved in response to recent changes in the amount of available habitat and associated implications for mobility. Rapid morphological evolution may mitigate, without necessarily preventing, negative consequences of habitat loss caused by humans through direct exploitation or climate change. PMID:20583699

  13. Solar wind variations in the 60-100 year period range: A review

    NASA Technical Reports Server (NTRS)

    Feynman, J.

    1983-01-01

    The evidence for and against the reality of a solar wind variation in the period range of 60-100 years is reexamined. Six data sets are reviewed; sunspot numbers, geomagnetic variations, two auroral data sets and two (14)C data sets. These data are proxies for several different aspects of the solar wind and the presence or absence of 60-100 year cyclic behavior in a particular data set does not necessarily imply the presence or absence of this variation in other sets. It was concluded that two different analyses of proxy data for a particular characteristic of the heliospheric solar wind yielded conflicting results. This conflict can be resolved only by future research. It is also definitely confirmed that proxy data for the solar wind in the ecliptic at 1 A.U. undergo a periodic variation with a period of approximately 87 years. The average amplitude and phase of this variation as seen in eleven cycles of proxy data are presented.

  14. The August 2002 flood in Salzburg / Austria experience gained and lessons learned from the ``Flood of the century''?

    NASA Astrophysics Data System (ADS)

    Wiesenegger, H.

    2003-04-01

    On the {12th} of August 2002 a low pressure system moved slowly from northern Italy towards Slovakia. It continuously carried moist air from the Mediterranean towards the northern rim of the Alps with the effect of wide-spread heavy rainfall in Salzburg and other parts of Austria. Daily precipitation amounts of 100 - 160 mm, in some parts even more, as well as rainfall intensities of 5 - 10 mm/h , combined with well saturated soils lead to a rare flood with a return period of 100 years and more. This rare hydrological event not only caused a national catastrophe with damages of several Billion Euro, but also endangered more than 200,000 people, and even killed some. As floods are dangerous, life-threatening, destructive, and certainly amongst the most frequent and costly natural disasters in terms of human hardship as well as economic loss, a great effort, therefore, has to be made to protect people against negative impacts of floods. In order to achieve this objective, various regulations in land use planning (flood maps), constructive measurements (river regulations and technical constructions) as well as flood warning systems, which are not suitable to prevent big floods, but offer in-time-warnings to minimize the loss of human lives, are used in Austria. HYDRIS (Hydrological Information System for flood forecasting in Salzburg), a modular river basin model, developed at Technical University Vienna and operated by the Hydrological Service of Salzburg, was used during the August 2002 flood providing accurate 3 to 4 hour forecasts within 3 % of the real peak discharge of the fast flowing River Salzach. The August {12^th}} flood was in many ways an exceptional, very fast happening event which took many people by surprise. At the gauging station Salzburg / Salzach (catchment area 4425 {km^2}) it took only eighteen hours from mean annual discharge (178 {m3/s}) to the hundred years flood (2300 {m3/s}). The August flood made clear, that there is a strong need for

  15. Groundwater discharge to wetlands driven by storm and flood events: Quantification using continuous Radon-222 and electrical conductivity measurements and dynamic mass-balance modelling

    NASA Astrophysics Data System (ADS)

    Gilfedder, B. S.; Frei, S.; Hofmann, H.; Cartwright, I.

    2015-09-01

    The dynamic response of groundwater discharge to external influences such as rainfall is an often neglected part of water and solute balances in wetlands. Here we develop a new field platform for long-term continuous 222Rn and electrical conductivity (EC) measurements at Sale Wetland, Australia to study the response of groundwater discharge to storm and flood events. The field measurements, combined with dynamic mass-balance modelling, demonstrate that the groundwater flux can increase from 3 to ∼20 mm d-1 following storms and up to 5 mm d-1 on the receding limb of floods. The groundwater pulses are likely produced by activation of local groundwater flow paths by water ponding on the surrounding flood plains. While 222Rn is a sensitive tracer for quantifying transient groundwater discharge, the mass-balance used to estimate fluxes is sensitive to parameterisation of gas exchange (k) with the atmosphere. Comparison of six equations for calculating k showed that, based on parameterisation of k alone, the groundwater flux estimate could vary by 58%. This work shows that neglecting transient processes will lead to errors in water and solute flux estimates based on infrequent point measurements. This could be particularly important for surface waters connected to contaminated or saline groundwater systems.

  16. Flood-frequency characteristics of Wisconsin streams

    USGS Publications Warehouse

    Walker, John F.; Krug, William R.

    2003-01-01

    Flood-frequency characteristics for 312 gaged sites on Wisconsin streams are presented for recurrence intervals of 2 to 100 years using flood-peak data collected through water year 2000. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of these equations. The state was divided into five areas with similar physiographic characteristics. The most significant basin characteristics are drainage area, main-channel slope, soil permeability, storage, rainfall intensity, and forest cover. The standard error of prediction for the equation for the 100-year flood discharge ranges from 22 to 44 percent in the state. A graphical method for estimating flood-frequency characteristics of regulated streams was developed from the relation of discharge and drainage area. Graphs for the major regulated streams are presented.

  17. Mining Subsidence-generated legacy sediments in a Mid-European low-order stream floodplain as an archive for historic human activity and flooding events

    NASA Astrophysics Data System (ADS)

    Buchty-Lemke, Michael; Lehmkuhl, Frank; Frings, Roy; Henkel, Sebastian; Schwarzbauer, Jan

    2015-04-01

    Legacy sediments, which were deposited as a consequence of mining subsidence in a floodplain area, can be used as an archive for human activity and past flooding. The morphodynamics of the Wurm River, a low-order stream in the Lower Rhine Embayment at the border between Germany and the Netherlands, is significantly influenced by a long colliery history, which caused alterations in the natural river landscape. In addition, substances which are transported via municipal wastewaters as well as contaminants emitted by specific regional industries were deposited in the floodplain sediments. This study aims at the reconstruction of human activity and past flooding events derived from geochemical and sedimentological data for different time slices within the 20st century. The spatial and chronological distribution of contaminants is investigated on the basis of several sections and drilling cores along the middle reaches of the Wurm River. Sections within mining subsidence areas and outside of those are compared regarding their sedimentation rates and element contents. Additional information is gathered from digital terrain models, historical documents such as the Tranchot map (early 19th century), and interviews of contemporary witnesses. Sedimentation rates derived from Cs-137 measurements allow a temporal assignment of the legacy sediments. A section within a segment of the Siegfried Line (Westwall), constructed in 1939, that crosses the Wurm River shows a significant increase in sedimentation rates in contrast to the floodplain area that is unaffected by subsidence processes. Furthermore, source-specific contaminants can be used to refine the stratigraphy, since source and period of emission are known. The evaluation of past flooding events is supported by numerical modeling of flood scenarios, which provides detailed information about flooded areas depending on the discharge, particularly for the areas which are under influence of mining subsidence. Besides the

  18. Urban flood analysis in Oklahoma City, Oklahoma

    USGS Publications Warehouse

    Tortorelli, Robert L.; Huntzinger, T.L.; Bergman, D.L.; Patneaude, A.L.

    1983-01-01

    Flood insurance study information from the Federal Emergency Management Agency is utilized to estimate future flood hazard in Oklahoma City, Oklahoma. Techniques are described for estimating future urban runoff estimates. A method of developing stream cross section rating curves is explained. Future runoff estimates are used in conjuction with the rating curves to develop an estimate of 50- and 100- year flood profiles that would result from future urban development.

  19. Design flood estimation in ungauged basins: probabilistic extension of the design-storm concept

    NASA Astrophysics Data System (ADS)

    Berk, Mario; Špačková, Olga; Straub, Daniel

    2016-04-01

    Design flood estimation in ungauged basins is an important hydrological task, which is in engineering practice typically solved with the design storm concept. However, neglecting the uncertainty in the hydrological response of the catchment through the assumption of average-recurrence-interval (ARI) neutrality between rainfall and runoff can lead to flawed design flood estimates. Additionally, selecting a single critical rainfall duration neglects the contribution of other rainfall durations on the probability of extreme flood events. In this study, the design flood problem is approached with concepts from structural reliability that enable a consistent treatment of multiple uncertainties in estimating the design flood. The uncertainty of key model parameters are represented probabilistically and the First-Order Reliability Method (FORM) is used to compute the flood exceedance probability. As an important by-product, the FORM analysis provides the most likely parameter combination to lead to a flood with a certain exceedance probability; i.e. it enables one to find representative scenarios for e.g., a 100 year or a 1000 year flood. Possible different rainfall durations are incorporated by formulating the event of a given design flood as a series system. The method is directly applicable in practice, since for the description of the rainfall depth-duration characteristics, the same inputs as for the classical design storm methods are needed, which are commonly provided by meteorological services. The proposed methodology is applied to a case study of Trauchgauer Ach catchment in Bavaria, SCS Curve Number (CN) and Unit hydrograph models are used for modeling the hydrological process. The results indicate, in accordance with past experience, that the traditional design storm concept underestimates design floods.

  20. The sensitivity of fluvial flood risk in Irish catchments to the range of IPCC AR4 climate change scenarios.

    PubMed

    Bastola, Satish; Murphy, Conor; Sweeney, John

    2011-11-15

    In the face of increased flood risk responsible authorities have set out safety margins to incorporate climate change impacts in building robust flood infrastructure. Using the case study of four catchments in Ireland, this study subjects such design allowances to a sensitivity analysis of the uncertainty inherent in estimates of future flood risk. Uncertainty in flood quantiles is quantified using regionalised climate scenarios derived from a large number of GCMs (17), forced with three SRES emissions scenarios. In terms of hydrological response uncertainty within and between hydrological models is assessed using the GLUE framework. Regionalisation is achieved using a change factor method to infer changes in the parameters of a weather generator using monthly output from the GCMs, while flood frequency analysis is conducted using the method of probability weighted moments to fit the Generalised Extreme Value distribution to ~20,000 annual maximia series. Sensitivity results show that for low frequency events, the risk of exceedence of design allowances is greater than for more frequent events, with considerable implications for critical infrastructure. Peak flows for the five return periods assessed were found to be less sensitive to temperature and subsequently to potential evaporation (PET) than to rainfall. The average width of the uncertainty range for changes in flood magnitude is greater for low frequency events than for high frequency events. In all catchments there is a progressive increase in the peak flows associated with the 5, 25, 50 and 100-year return periods when moving from the 2020s to the 2080s. PMID:21943724

  1. Optimization of the resolution of remotely sensed digital elevation model to facilitate the simulation and spatial propagation of flood events in flat areas

    NASA Astrophysics Data System (ADS)

    Karapetsas, Nikolaos; Skoulikaris, Charalampos; Katsogiannos, Fotis; Zalidis, George; Alexandridis, Thomas

    2013-04-01

    The use of satellite remote sensing products, such as Digital Elevation Models (DEMs), under specific computational interfaces of Geographic Information Systems (GIS) has fostered and facilitated the acquisition of data on specific hydrologic features, such as slope, flow direction and flow accumulation, which are crucial inputs to hydrology or hydraulic models at the river basin scale. However, even though DEMs of different resolution varying from a few km up to 20m are freely available for the European continent, these remotely sensed elevation data are rather coarse in cases where large flat areas are dominant inside a watershed, resulting in an unsatisfactory representation of the terrain characteristics. This scientific work aims at implementing a combing interpolation technique for the amelioration of the analysis of a DEM in order to be used as the input ground model to a hydraulic model for the assessment of potential flood events propagation in plains. More specifically, the second version of the ASTER Global Digital Elevation Model (GDEM2), which has an overall accuracy of around 20 meters, was interpolated with a vast number of aerial control points available from the Hellenic Mapping and Cadastral Organization (HMCO). The uncertainty that was inherent in both the available datasets (ASTER & HMCO) and the appearance of uncorrelated errors and artifacts was minimized by incorporating geostatistical filtering. The resolution of the produced DEM was approximately 10 meters and its validation was conducted with the use of an external dataset of 220 geodetic survey points. The derived DEM was then used as an input to the hydraulic model InfoWorks RS, whose operation is based on the relief characteristics contained in the ground model, for defining, in an automated way, the cross section parameters and simulating the flood spatial distribution. The plain of Serres, which is located in the downstream part of the Struma/Strymon transboundary river basin shared

  2. River flood events as natural tracers for investigating the hydrological dynamics of a coupled river-aquifer system: preliminary results from 3D crosshole electrical resistivity monitoring

    NASA Astrophysics Data System (ADS)

    Coscia, I.; Greenhalgh, S. A.; Linde, N.; Doetsch, J.; Vogt, T.; Green, A. G.

    2009-12-01

    This research, on geoelectric monitoring of changing aquifer conditions associated with flood events of the River Thur in Switzerland, forms part of the much wider RECORD (REstored CORridor Dynamics) project. Major precipitation and snow-melt events cause rapid undamped fluctuations of discharge along the entire length of the river. River water that infiltrates the neighbouring aquifer normally has higher electrical resistivity than that of the groundwater during the early stages of flood events. This enables us to use infiltration during such events as a natural tracer in 3D time-lapse electrical resistivity tomography (ERT) experiments. Over a 10 x 15 m areal array, we have installed eighteen 12-m-deep monitoring boreholes spaced 3.5 m apart that completely penetrate the underlying 7-m-thick aquifer. Each borehole has been instrumented with ten 0.7-m-spaced electrodes that span the thickness of the aquifer. A multichannel resistivity meter, programmed to cycle through various 4-point electrode configurations of the 180 electrodes in a rolling sub-sequence, allows the collection of a 15,000-measurement data set every ~7 hours. Fourteen of these boreholes are also equipped with STS sensors that provide time-series of water-table depth and water temperature and electrical conductivity. Three-dimensional static ERT inversion at stable hydrological conditions was performed to investigate the resolving capability of our measuring sequence and to define the main lithological structures within the aquifer. Preliminary analyses of the ERT time series collected during a major flooding event this past summer suggest that the data are sensitive to three factors: water-level fluctuations in the aquifer, water-temperature variations, and electrical conductivity changes associated with changing salinity of the groundwater. The total changes in apparent resistivity are of the order of 20%. Since our primary interest is in the salinity effect that might be used to delineate

  3. Tree rings record 100 years of hydrologic change within a wetland

    USGS Publications Warehouse

    Yanosky, Thomas M.; Kappel, William M.

    1997-01-01

    Hydrology and tree growth were investigated within a small wetland in the Tully Valley of central New York, about 20 miles south of Syracuse. In late 1994 it was noted that some wetland trees were dying, and local residents reported that flow of a small stream draining the wetland seemingly increased and became more brackish since the mid to late 1980s. The wetland is about 3 miles north of an extensive salt mining operation known to have degraded local water quality, but no effects of mining had been confirmed previously near the wetland. The oldest wetland trees started to grow before the onset of mining in 1889, and thus tree-ring studies were undertaken not only to investi-gate recent hydrologic change within the wetland, but also to search for evidence of any other changes during the last 100 years.

  4. Sustainable Foods and Medicines Support Vitality, Sex and Longevity for a 100-Year Starship Expedition

    NASA Astrophysics Data System (ADS)

    Edwards, M. R.

    Extended space flight requires foods and medicines that sustain crew health and vitality. The health and therapeutic needs for the entire crew and their children for a 100-year space flight must be sustainable. The starship cannot depend on resupply or carry a large cargo of pharmaceuticals. Everything in the starship must be completely recyclable and reconstructable, including food, feed, textiles, building materials, pharmaceuticals, vaccines, and medicines. Smart microfarms will produce functional foods with superior nutrition and sensory attributes. These foods provide high-quality protein and nutralence (nutrient density), that avoids obesity, diabetes, and other Western diseases. The combination of functional foods, lifestyle actions, and medicines will support crew immunity, energy, vitality, sustained strong health, and longevity. Smart microfarms enable the production of fresh medicines in hours or days, eliminating the need for a large dispensary, which eliminates concern over drug shelf life. Smart microfarms are adaptable to the extreme growing area, resource, and environmental constraints associated with an extended starship expedition.

  5. 100-year DASCH Light Curves of Kepler Planet-Candidate Host Stars

    NASA Astrophysics Data System (ADS)

    Tang, Sumin; Sasselov, Dimitar; Grindlay, Jonathan; Los, Edward; Servillat, Mathieu

    2013-07-01

    We present 100 year light curves of Kepler planet-candidate host stars from the Digital Access to a Sky Century at Harvard (DASCH) project. 261 out of 997 host stars have at least 10 good measurements on DASCH scans of the Harvard plates. 109 of them have at least 100 good measurements, including 70% (73 out of 104) of all host stars with g <= 13 mag, and 44% (100 out of 228) of all host stars with g <= 14 mag. Our typical photometric uncertainty is ~0.1-0.15 mag. No variation is found at 3σ level for these host stars, including 21 confirmed or candidate hot Jupiter systems which might be expected to show enhanced flares from magnetic interactions between dwarf primaries and their close and relatively massive planet companions.

  6. 100 years of Pb deposition and transport in soils in Champaign, Illinois, U.S.A

    USGS Publications Warehouse

    Zhang, Y.

    2003-01-01

    In Illinois, atmospheric deposition is one major source of heavy metal inputs to agricultural land. The atmospheric Pb deposition and transport record in agricultural soils in Champaign, Illinois, was established by studying surface and subsurface soil samples collected during the past 100 years from the Morrow Plots on the campus of the University of Illinois at Urbana-Champaign. The Pb content in the soil samples was measured and the Ph deposition fluxes were calculated. The Pb content in surface soils increased sharply in the first half of the 20th century, and stayed invariant since. The maximum Pb flux from the atmosphere was estimated to be 27 (??14) ??g cm-2 yr-1 around 1940. The major pollution source for this increase probably was residential coal burning. It was estimated that in 50 yr, more than 50% of the Pb input had been lost from the surface soils.

  7. A profile of Frank Harrison: a pioneering Sheffield dentist from 100 years ago.

    PubMed

    Figures, K; Smith, C

    2012-10-01

    A review of the personal papers relating to Frank Harrison and held by the School of Clinical Dentistry in Sheffield reveal what a dedicated clinician he was and the significance of his achievements from over 100 years ago, both locally and nationally for his chosen profession and also for the people of Sheffield. In addition to being one of the first dentists in the world to experiment with X-rays in dentistry, and the first to write up his findings in a dental journal, he designed and patented dental instruments, wrote books, lectured on fine art (particularly Venetian and Florentine art), and gave lectures to the public in the hope that they would heed his message on the importance of maintaining good oral health. A search of national archives and library resources has added further information about his family and professional accomplishments. PMID:23099699

  8. The Reissner Canard: The first all-metal airplane 100 years ago

    NASA Astrophysics Data System (ADS)

    Krause, Egon

    2012-10-01

    In 1912 Professor Hans Reissner of the Technical University Aachen built a canard-type aeroplane, the world-wide first completely out of metal: although the Reissner Canard initiated a new technology with the Junkers J1 the first to follow in 1915 and 1000 more until now, little is known about the very first steps way back in Aachen. This paper tries to recapture some details of the developments 100 years ago with the aid of early publications and photographs and shed some light on the first wing fabricated out of a corrugated aluminum sheet mounted at the tail of the braced-steel-pipe fuselage to earn its airworthiness in Berlin Johannisthal in 1912.

  9. PREFACE: Spanish Relativity Meeting (ERE 2014): almost 100 years after Einstein's revolution

    NASA Astrophysics Data System (ADS)

    Cerdá-Durán, P.; Font, J. A.; Ibáñez, J. M.; Lledó, M. A.; Navarro-Salas, J.; Olmo, G. J.

    2015-04-01

    This volume presents the proceedings of the international scientific conference ''Spanish Relativity Meeting (ERE 2014): almost 100 years after Einstein's revolution''. The conference was devoted to discussing the current state-of-the-art of a wide variety of topics of research in the fields of Gravitation and General Relativity in the ''pre-centennial'' year of General Relativity. The name of the conference was chosen to highlight the importance of the upcoming one hundredth anniversary of Einstein's theory of General Relativity, officially established by the Internal Society on General Relativity and Gravitation in November 25th, 2015. In particular, the conference was organized along three main lines of present-day research and applications of the theory, namely, Relativistic Astrophysics, Mathematical Relativity, and the interface between Gravitation and Quantum Field Theory.

  10. Epic Flooding in Georgia, 2009

    USGS Publications Warehouse

    Gotvald, Anthony J.; McCallum, Brian E.

    2010-01-01

    Metropolitan Atlanta-September 2009 Floods * The epic floods experienced in the Atlanta area in September 2009 were extremely rare. Eighteen streamgages in the Metropolitan Atlanta area had flood magnitudes much greater than the estimated 0.2-percent (500-year) annual exceedance probability. * The Federal Emergency Management Agency (FEMA) reported that 23 counties in Georgia were declared disaster areas due to this flood and that 16,981 homes and 3,482 businesses were affected by floodwaters. Ten lives were lost in the flood. The total estimated damages exceed $193 million (H.E. Longenecker, Federal Emergency Management Agency, written commun., November 2009). * On Sweetwater Creek near Austell, Ga., just north of Interstate 20, the peak stage was more than 6 feet higher than the estimated peak stage of the 0.2-percent (500-year) flood. Flood magnitudes in Cobb County on Sweetwater, Butler, and Powder Springs Creeks greatly exceeded the estimated 0.2-percent (500-year) floods for these streams. * In Douglas County, the Dog River at Ga. Highway 5 near Fairplay had a peak stage nearly 20 feet higher than the estimated peak stage of the 0.2-percent (500-year) flood. * On the Chattahoochee River, the U.S. Geological Survey (USGS) gage at Vinings reached the highest level recorded in the past 81 years. Gwinnett, De Kalb, Fulton, and Rockdale Counties also had record flooding. South Georgia March and April 2009 Floods * The March and April 2009 floods in South Georgia were smaller in magnitude than the September floods but still caused significant damage. * No lives were lost in this flood. Approximately $60 million in public infrastructure damage occurred to roads, culverts, bridges and a water treatment facility (Joseph T. McKinney, Federal Emergency Management Agency, written commun., July 2009). * Flow at the Satilla River near Waycross, exceeded the 0.5-percent (200-year) flood. Flows at seven other stations in South Georgia exceeded the 1-percent (100-year) flood.

  11. Influence of anthropogenic inputs and a high-magnitude flood event on metal contamination pattern in surface bottom sediments from the Deba River urban catchment.

    PubMed

    Martínez-Santos, Miren; Probst, Anne; García-García, Jon; Ruiz-Romera, Estilita

    2015-05-01

    The purpose of this study was to assess the influence of anthropogenic factors (infrastructure construction and industrial and wastewater inputs) and hydrological factors (high-magnitude flood events) on metal and organic contamination and on the source variability of sediments taken from the Deba River and its tributaries. The pollution status was evaluated using a sequential extraction procedure (BCR 701), enrichment factor, individual and global contamination factors and a number of statistical analysis methods. Zn, Cu and Cr were found to have significant input from anthropogenic sources, with moderately severe enrichment, together with an extremely high potential risk of contamination. The principal scavenger of Cu and Cr was organic matter, whereas Zn was uniformly distributed among all non-residual fractions. For Fe, the anthropogenic contribution was more obviously detected in bulk sediments (<2 mm) than in fine fractions (<63 μm). Finally, the recent construction of a rail tunnel traversing Wealden Facies evaporites, together with intense rainfalls, was the main reason for the change in the source variability of bottom sediments and metal distribution in headwaters. The occurrence of a high-magnitude flood event resulted in a washout of the river bed and led to a general decrease in fine-grained sediment and metal concentrations in labile fractions of channel-bottom sediments, and a consequent downstream transfer of the pollution. PMID:25647464

  12. Flood hazard assessment in areas prone to flash flooding

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  13. 100+ years of instrumental seismology: the example of the ISC-GEM Global Earthquake Instrumental Catalogue

    NASA Astrophysics Data System (ADS)

    Storchak, Dmitry; Di Giacomo, Domenico

    2015-04-01

    Systematic seismological observations of earthquakes using seismic instruments on a global scale began more than 100 years ago. Since then seismologists made many discoveries about the Earth interior and the physics of the earthquakes, also thanks to major developments in the seismic instrumentation deployed around the world. Besides, since the establishment of the first global networks (Milne and Jesuit networks), seismologists around the world stored and exchanged the results of routine observations (e.g., picking of arrival times, amplitude-period measurements, etc.) or more sophisticated analyses (e.g., moment tensor inversion) in seismological bulletins/catalogues. With a project funded by the GEM Foundation (www.globalquakemodel.org), the ISC and the Team of International Experts released a new global earthquake catalogue, the ISC-GEM Global Instrumental Earthquake Catalogue (1900 2009) (www.isc.ac.uk/iscgem/index.php), which, differently from previous global seismic catalogues, has the unique feature of covering the entire period of instrumental seismology with locations and magnitude re-assessed using modern approaches for the global earthquakes selected for processing (in the current version approximately 21,000). During the 110 years covered by the ISC-GEM catalogue many seismological developments occurred in terms of instrumentation, seismological practice and knowledge of the physics of the earthquakes. In this contribution we give a brief overview of the major milestones characterizing the last 100+ years of instrumental seismology that were relevant for the production of the ISC-GEM catalogue and the major challenges we faced to obtain a catalogue as homogenous as possible.

  14. Development of flood index by characterisation of flood hydrographs

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Biswa; Suman, Asadusjjaman

    2015-04-01

    In recent years the world has experienced deaths, large-scale displacement of people, billions of Euros of economic damage, mental stress and ecosystem impacts due to flooding. Global changes (climate change, population and economic growth, and urbanisation) are exacerbating the severity of flooding. The 2010 floods in Pakistan and the 2011 floods in Australia and Thailand demonstrate the need for concerted action in the face of global societal and environmental changes to strengthen resilience against flooding. Due to climatological characteristics there are catchments where flood forecasting may have a relatively limited role and flood event management may have to be trusted upon. For example, in flash flood catchments, which often may be tiny and un-gauged, flood event management often depends on approximate prediction tools such as flash flood guidance (FFG). There are catchments fed largely by flood waters coming from upstream catchments, which are un-gauged or due to data sharing issues in transboundary catchments the flow of information from upstream catchment is limited. Hydrological and hydraulic modelling of these downstream catchments will never be sufficient to provide any required forecasting lead time and alternative tools to support flood event management will be required. In FFG, or similar approaches, the primary motif is to provide guidance by synthesising the historical data. We follow a similar approach to characterise past flood hydrographs to determine a flood index (FI), which varies in space and time with flood magnitude and its propagation. By studying the variation of the index the pockets of high flood risk, requiring attention, can be earmarked beforehand. This approach can be very useful in flood risk management of catchments where information about hydro-meteorological variables is inadequate for any forecasting system. This paper presents the development of FI and its application to several catchments including in Kentucky in the USA

  15. Flood-prone areas of Jacksonville, Duval County, Florida

    USGS Publications Warehouse

    Stone, Richard B.; Causey, Lawson V.; Tucker, D.F.

    1976-01-01

    Floods in the consolidated city of Jacksonville, Duval County, Florida, are caused directly by rainfall which, when combined with storm driven tides, causes rivers or other bodies of water to flood the low lying parts of the county. This map report supplies information on areas subject to floods of 100-year frequency; the information will permit evaluation of alternative uses of such areas. The extent of the 100-year flood is shown on the large-scale map accompanying the report. Also included is an index map showing sections of Duval County where more detailed information on the 100-year flood can be obtained. The major flood of record in the county occurred in 1964 when Hurricane Dora crossed the area. (Woodard-USGS)

  16. Natural Flood Management in context: evaluating and enhancing the impact.

    NASA Astrophysics Data System (ADS)

    Metcalfe, Peter; Beven, Keith; Hankin, Barry; Lamb, Rob

    2016-04-01

    The series of flood events in the UK throughout December 2015 have led to calls for a reappraisal of the country's approach to flood management. In parts of Cumbria so-called "1 in 100" year floods have occurred three times in the last ten years, leading to significant infrastructure damage. Hard-engineered defences upgraded to cope with an anticipated 20% increase in peak flows and these 1% AEP events have been overwhelmed. It has become more widely acknowledged that unsympathetic agricultural and upland management practices, mainly since the Second World War, have led to a significant loss of storage in mid and upper catchments and their consequent ability to retain and slow storm run-off. Natural Flood Management (NFM) is a nature-based solution to restoring this storage and flood peak attenuation through a network of small-scale features exploiting natural topography and materials. Combined with other "soft" interventions such as restoring flood plain roughness and tree-planting, NFM offers the attractive prospect of an intervention that can target both the ecological and chemical objectives of the Water Framework Directive and the resilience demanded by the Floods Directive. We developed a simple computerised physical routing model that can account for the presence of in-channel and offline features such as would be found in a NFM scheme. These will add storage to the channel and floodplain and throttle the downstream discharge at storm flows. The model was applied to the heavily-modified channel network of an agricultural catchment in North Yorkshire using the run-off simulated for two storm events that caused flooding downstream in the autumn of 2012. Using up to 60 online features we demonstrated some gains in channel storage and a small impact on the flood hydrograph which would, however, have been insufficient to prevent the downstream floods in either of the storms. Complementary research at JBA has applied their hydrodynamic model JFLOW+ to identify

  17. Challenges estimating the return period of extreme floods for reinsurance applications

    NASA Astrophysics Data System (ADS)

    Raven, Emma; Busby, Kathryn; Liu, Ye

    2013-04-01

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

  18. Potential flood and debris hazards at Cottonwood Cove, Lake Mead National Recreation Area, Clark County, Nevada

    USGS Publications Warehouse

    Moosburner, Otto

    1981-01-01

    At Cottonwood Cove, Nevada, most of the existing dikes at the recreation sites are effective in diverting and routing floodflows, up to and including the 100-year flood, away from people and facilities. The dikes across Ranger Residence Wash and Access Road Wash at the mouth divert floods up to the 50-year recurrence interval away from residential areas. Flow and debris damage in protected areas will be relatively minor minor for floods including the 100-year flood, whereas damage caused by sediment deposition at the mouths of the washes near Lake Mohave could be significant for floods equal to or less than the 100-year flood. The extreme flood, a flood meteorologically and hydrologically possible but so rare as to preclude a frequency estimate, could cause great damage and possible loss of life. The present dikes would be topped or breached by such flooding. (USGS)

  19. On the Influence of the NAO on Outlet Glacier Stability in SE Greenland during the Past 100 Years

    NASA Astrophysics Data System (ADS)

    Andresen, C. S.

    2014-12-01

    The Greenland Ice sheet has gained massive attention in recent years due to a sudden increase in mass loss at the onset of this century. A significant part of this mass loss has been attributed to increased ice discharge at the margin through iceberg calving from marine-terminating outlet glaciers. However, due to the lack of instrumental data beyond the past 20-30 years it is difficult to evaluate if this was an outstanding event or if it was part of a recurring phenomenon acting on inter-annual, inter-decadal or centennial timescales. In order to improve understanding of the timescales involved in glacier changes and on the influence of ocean and atmosphere variability we investigate sediment archives from fjords with marine terminating glaciers. Near the glacier margin the sedimentation rates are relatively high due to glacial flour input and rafting of iceberg debris. Our studies of several sediment cores obtained from Sermilik Fjord by Helheim Glacier in Southeast Greenland has allowed us to reconstruct glacier calving, shelf temperature and fjord water renewal rate for the past 100 years. These studies show that dominant modes of climate variability, i.e. the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation, affect ocean properties near the glacier and that the recorded variability concurs with reconstructed outlet glacier changes. This presentation provides an overview these studies.

  20. Reconstruction of peak water levels, peak discharges and long-term occurrence of extreme- as well as smaller pre-instrumental flood events of river Aare, Limmat, Reuss, Rhine and Saane in Switzerland. Part I

    NASA Astrophysics Data System (ADS)

    Wetter, Oliver; Tuttenuj, Daniel

    2016-04-01

    Part I: Dr. Oliver Wetter. (Oeschger Centre for Climate Change Research, University of Bern, Switzerland) Part II: PhD student Daniel Tuttenuj (Oeschger Centre of Climate Change Research, University of Bern, Switzerland) The methodology developed by Wetter et al. (2011) combines different documentary and instrumental sources, retaining relevant information for the reconstruction of extreme pre-instrumental flood events. These include hydrological measurements (gauges), historic river profiles (cross and longitudinal profiles), flood marks, historic city maps, documentary flood evidence (reports in chronicles and newspapers) as well as paintings and drawings. It has been shown that extreme river Rhine flood events of the pre-instrumental period can be reconstructed in terms of peak discharges for the last 750 years by applying this methodology to the site of Basel. Pfister & Wetter (2011) furthermore demonstrated that this methodology is also principally transferable to other locations and rivers. Institutional documentary evidence has not been systematically analysed in the context of historical hydrology in Switzerland so far. The term institutional documentary evidence generally outlines sources that were produced by governments or other (public) bodies including the church, hospitals, and the office of the bridge master. Institutional bodies were typically not directly interested in describing climate or hydrological events but they were obliged to document their activities, especially if they generated financial costs (bookkeeping), and in doing so they often indirectly recorded climatologic or hydrological events. The books of weekly expenditures of Basel ("Wochenausgabenbücher der Stadt Basel") were first analysed by Fouquet (1999). He found recurring records of wage expenditures for a squad of craftsmen that was called up onto the bridge with the task of preventing the bridge from being damaged by fishing out drifting logs from the flood waters. Fouquet

  1. Reconstruction of peak water levels, peak discharges and long-term occurrence of extreme- as well as smaller pre-instrumental flood events of river Aare, Limmat, Reuss, Rhine and Saane in Switzerland. Part II.

    NASA Astrophysics Data System (ADS)

    Tuttenuj, Daniel; Wetter, Oliver

    2016-04-01

    The methodology developed by Wetter et al. (2011) combines different documentary and instrumental sources, retaining relevant information for the reconstruction of extreme pre-instrumental flood events. These include hydrological measurements (gauges), historic river profiles (cross and longitudinal profiles), flood marks, historic city maps, documentary flood evidence (reports in chronicles and newspapers) as well as paintings and drawings. It has been shown that extreme river Rhine flood events of the pre-instrumental period can be reconstructed in terms of peak discharges for the last 750 years by applying this methodology to the site of Basel. Pfister & Wetter (2011) furthermore demonstrated that this methodology is also principally transferable to other locations and rivers in Switzerland. Institutional documentary evidence has not been systematically analysed in the context of historical hydrology in Switzerland so far. The term institutional documentary evidence generally outlines sources that were produced by governments or other (public) bodies including the church, hospitals, and the office of the bridge master. Institutional bodies were typically not directly interested in describing climate or hydrological events but they were obliged to document their activities, especially if they generated financial costs (bookkeeping), and in doing so they often indirectly recorded climatologic or hydrological events. The books of weekly expenditures of Basel ("Wochenausgabenbücher der Stadt Basel") were first analysed by Fouquet (1999). He found recurring records of wage expenditures for a squad of craftsmen that was called up onto the bridge with the task of preventing the bridge from being damaged by fishing out drifting logs from the flood waters. Fouquet systematically analysed the period from 1446-1542 and could prove a large number of pre-instrumental flood events of river Rhine, Birs, Birsig and Wiese in Basel. All in all the weekly led account books

  2. Topography/landscape variations and perception of the flooding hazard and risk in coastal lowlands and floodplains

    NASA Astrophysics Data System (ADS)

    Stiros, Stathis C.; Pytharouli, Stella

    2014-05-01

    Urbanization and economic exploitation of coastal lowlands and of floodplains or of lagoons around deltas has highly modified the pattern of flooding in a global scale, especially in the last 30-100 years. Dykes along streams and rivers or sewage systems in cities are oriented to offer protection against common floods, but tend to intensify the effects of strong or of extreme flooding events because of floodwater trapping. The flow of the river water is also constrained by various buildings and other constructions which are exposed to flooding and other type of damage. Reclaimed and protected land of different types, including that by dams, dykes and river by-passes is exposed to deformation (subsidence, slow slumping towards the depocenter), as recent geodetic, mainly data reveal, with the risk of flooding highly amplified by the amount of subsidence. Modification of openings of lagoons, especially to serve harbours, amplifies the mass of intruding water and the rates of flooding. In addition, changes in the landscape uphill (deforestation etc.) amplifies the flow of water in both normal and extreme precipitation events. All these, in combination with abundance of global-scale, usually nearly real-time, dramatized information, give the impression of recent substantial changes in the primary causes of flooding (natural effect-hazard), shadowing effects which practically control the highly increased risk (amount/possibility of damage- societal impact), and tend to overestimate the climatic factor.

  3. Alabama district flood plan

    USGS Publications Warehouse

    Hedgecock, T. Scott; Pearman, J. Leroy; Stricklin, Victor E.

    2002-01-01

    The purpose of this flood plan is to outline and record advance planning for flood emergencies, so that all personnel will know the general plan and have a ready-reference for necessary information. This will ensure that during any flood event, regardless of the extent or magnitude, the resources of the District can be mobilized into a maximum data collection operation with a mimimum of effort.

  4. Effects of the 1993 flood on the determination of flood magnitude and frequency in Iowa

    USGS Publications Warehouse

    Eash, David A.

    1997-01-01

    Several factors, which included recurrence intervals for the 1993 peak discharges and the effective record lengths for 1993, were investigated for the 62 selected streamflow-gaging stations to evaluate their possible effect on the computed flood-frequency discharges. The combined effect of these two factors on the computed 100-year recurrence-interval discharges was significant. Gaging stations were grouped into four discrete categories on the basis ofrecurrence intervals for the 1993 peak discharges and the effective record lengths for 1993 . Of the 28 gaging stations that had small flood magnitudes in 1993 and long record lengths, the difference between the 1992 and the 1993 flood-frequency analyses for 100- year recurrence-interval discharges at 22 gaging stations was less than 5 percent. Of the 10 gaging stations that had large flood magnitudes in 1993 and short record lengths, the increase in 100-year recurrence-interval discharges at 9 gaging stations was greater than 15 percent.

  5. From Smallpox to Big Data: The Next 100 Years of Epidemiologic Methods.

    PubMed

    Gange, Stephen J; Golub, Elizabeth T

    2016-03-01

    For more than a century, epidemiology has seen major shifts in both focus and methodology. Taking into consideration the explosion of "big data," the advent of more sophisticated data collection and analytical tools, and the increased interest in evidence-based solutions, we present a framework that summarizes 3 fundamental domains of epidemiologic methods that are relevant for the understanding of both historical contributions and future directions in public health. First, the manner in which populations and their follow-up are defined is expanding, with greater interest in online populations whose definition does not fit the usual classification by person, place, and time. Second, traditional data collection methods, such as population-based surveillance and individual interviews, have been supplemented with advances in measurement. From biomarkers to mobile health, innovations in the measurement of exposures and diseases enable refined accuracy of data collection. Lastly, the comparison of populations is at the heart of epidemiologic methodology. Risk factor epidemiology, prediction methods, and causal inference strategies are areas in which the field is continuing to make significant contributions to public health. The framework presented herein articulates the multifaceted ways in which epidemiologic methods make such contributions and can continue to do so as we embark upon the next 100 years. PMID:26443419

  6. Psychologists in medical schools and academic medical centers: over 100 years of growth, influence, and partnership.

    PubMed

    Robiner, William N; Dixon, Kim E; Miner, Jacob L; Hong, Barry A

    2014-04-01

    Psychologists have served on the faculties of medical schools for over 100 years. Psychologists serve in a number of different roles and make substantive contributions to medical schools' tripartite mission of research, education, and clinical service. This article provides an overview of the history of psychologists' involvement in medical schools, including their growing presence in and integration with diverse departments over time. We also report findings from a survey of medical school psychologists that explored their efforts in nonclinical areas (i.e., research, education, administration) as well as clinical endeavors (i.e., assessment, psychotherapy, consultation). As understanding of the linkage between behavioral and psychological factors and health status and treatment outcomes increases, the roles of psychologists in health care are likely to expand beyond mental health. An increasing focus on accountability-related to treatment outcomes and interprofessional research, education, and models of care delivery-will likely provide additional opportunities for psychologists within health care and professional education. The well-established alignment of psychologists' expertise and skills with the mission and complex organizational needs of medical schools augurs a partnership on course to grow stronger. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:24588315

  7. [Nutrient dynamics over the past 100 years and its restoration baseline in Dianshan Lake].

    PubMed

    Li, Xiao-Ping; Chen, Xiao-Hua; Dong, Xu-Hui; Dong, Zhi; Sun, Dun-Ping

    2012-10-01

    The restoration of eutrophic lakes requires a good knowledge on the history and baseline of nutrients in the lakes. This work conducted an analysis on 210Pb/137Cs, water content, loss-on-ignition, sedimentary total phosphorus (TP), total nitrogen (TN), total organic carbon (TOC) and diatoms in the four sediment cores from Dianshan Lake (near Shanghai City). Good coherence in palaeoproxies between the cores indicates a relatively stable sedimentary environment. With increasing human impact, diatom communities shifted from oligo-trophic species Cyclotella bodanica, C. ocelata, Achnanthes minutissima, Cocconeis placentula var lineate, Cymbella sp. , Fragilaria pintata, F. brevistrata, F. construens var venter to recent eutrophic species including Cyclostephanos dubias, C. atomus, Stephanodiscus minitulus, S. hantzschi, Aulacoseria alpigena. The epilimnetic TP over the past 100 years reconstructed using an established diatom-TP transfer function matches well with the monitoring TP where exists. Based on the sedimentary nutrient characteristics and diatom-reconstructed nutrient dynamics, we proposed that the nutrient baseline for Dianshan Lake is 50-60 microg x L(-1), 500 mg x kg(-1) and 550 mg x kg(-1) for water TP concentration, sedimentary TP and TN, respectively. PMID:23233952

  8. Rainfall and drought in equatorial east Africa during the past 1,100 years.

    PubMed

    Verschuren, D; Laird, K R; Cumming, B F

    2000-01-27

    Knowledge of natural long-term rainfall variability is essential for water-resource and land-use management in sub-humid regions of the world. In tropical Africa, data relevant to determining this variability are scarce because of the lack of long instrumental climate records and the limited potential of standard high-resolution proxy records such as tree rings and ice cores. Here we present a decade-scale reconstruction of rainfall and drought in equatorial east Africa over the past 1,100 years, based on lake-level and salinity fluctuations of Lake Naivasha (Kenya) inferred from three different palaeolimnological proxies: sediment stratigraphy and the species compositions of fossil diatom and midge assemblages. Our data indicate that, over the past millennium, equatorial east Africa has alternated between contrasting climate conditions, with significantly drier climate than today during the 'Medieval Warm Period' (approximately AD 1000-1270) and a relatively wet climate during the 'Little Ice Age' (approximately AD 1270-1850) which was interrupted by three prolonged dry episodes. We also find strong chronological links between the reconstructed history of natural long-term rainfall variation and the pre-colonial cultural history of east Africa, highlighting the importance of a detailed knowledge of natural long-term rainfall fluctuations for sustainable socio-economic development. PMID:10667789

  9. Migration and health in Southern Africa: 100 years and still circulating

    PubMed Central

    Lurie, Mark N.; Williams, Brian G.

    2014-01-01

    Migration has deep historical roots in South and Southern Africa and to this day continues to be highly prevalent and a major factor shaping South African society and health. In this paper we examine the role of migration in the spread of two diseases nearly 100 years apart: tuberculosis following the discovery of gold in 1886 and HIV in the early 1990s. Both cases demonstrate the critical role played by human migration in the transmission and subsequent dissemination of these diseases to rural areas. In both cases, migration acts to assemble in one high-risk environment thousands of young men highly susceptible to new diseases. With poor living and working conditions, these migration destinations act as hot-spots for disease transmission. Migration of workers back to rural areas then serves as a highly efficient means of disseminating these diseases to rural populations. We conclude by raising some more recent questions examining the current role of migration in Southern Africa. PMID:24653964

  10. Action Stations! 100 years of trauma care on maritime and amphibious operations in the Royal Navy.

    PubMed

    Osborne, M; Smith, J E

    2015-01-01

    Over the past century trauma care within the Royal Navy (RN) has evolved; wartime experiences and military medical research have combined to allow significant improvement in the care of casualties. This article describes the key maritime and amphibious operations that have seen the Royal Navy Medical Service (RNMS) deliver high levels of support to wherever the Naval Service has deployed in the last 100 years. Key advancements in which progress has led to improved outcomes for injured personnel are highlighted--the control and treatment of blood loss, wound care, and the prevention and management of organ failure with optimal resuscitation. Historians often point out how slowly military medicine progressed for the first few thousand years of its recorded history, and how quickly it has progressed in the last century. This reflective article will show how the RNMS has been an integral part of that story, and how the lessons learnt by our predecessors have shaped our modern day doctrine surrounding trauma care. PMID:26292385

  11. [100 years of Draeger Medical Technology (1902 - 2002) -- working for the applicability of oxygen].

    PubMed

    Strätling, M; Schmucker, P

    2004-09-01

    This survey analyses the history of 100 years of Draeger Medical Technology. Between 1889 and 1902 a number of inventions on the field of pressure gas technology allowed to solve application problems, which until then proved major obstacles to the safe and efficient use of compressed gases such as oxygen, nitrous oxide or carbon dioxide for medical and industrial purposes. A special significance is to be awarded here to pressure reducing valves, but also reliable manometers, nozzles and valves for pressure tanks were not generally available until then. These were first successfully and on a really significant scale introduced into international medical and non-medical pressure-gas technology by Draeger Inc. (Luebeck/Germany), and proved particularly successful in anaesthesia and rescue-devices (e. g. in the "Roth-Draeger Anaesthesia Apparatus" (1902). Consequently, starting in 1902, Draeger Inc. increasingly put an emphasis on developing medical and rescue technology and -- by doing so -- gained an important influence on the history of the implementation of modern oxygen therapy and of inhalative anaesthesia. A survey of the historically most important Draeger-Developments is provided. PMID:15490342

  12. Tsunami flooding

    USGS Publications Warehouse

    Geist, Eric; Jones, Henry; McBride, Mark; Fedors, Randy

    2013-01-01

    Panel 5 focused on tsunami flooding with an emphasis on Probabilistic Tsunami Hazard Analysis (PTHA) as derived from its counterpart, Probabilistic Seismic Hazard Analysis (PSHA) that determines seismic ground-motion hazards. The Panel reviewed current practices in PTHA and determined the viability of extending the analysis to extreme design probabilities (i.e., 10-4 to 10-6). In addition to earthquake sources for tsunamis, PTHA for extreme events necessitates the inclusion of tsunamis generated by submarine landslides, and treatment of the large attendant uncertainty in source characterization and recurrence rates. Tsunamis can be caused by local and distant earthquakes, landslides, volcanism, and asteroid/meteorite impacts. Coastal flooding caused by storm surges and seiches is covered in Panel 7. Tsunamis directly tied to earthquakes, the similarities with (and path forward offered by) the PSHA approach for PTHA, and especially submarine landslide tsunamis were a particular focus of Panel 5.

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

    NASA Astrophysics Data System (ADS)

    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

  14. Evolution of flood typology across Europe

    NASA Astrophysics Data System (ADS)

    Hundecha, Yeshewatesfa; Parajka, Juraj; Viglione, Alberto

    2016-04-01

    Following the frequent occurrence of severe flood events in different parts of Europe in the recent past, there has been a rise in interest in understanding the mechanisms by which the different events have been triggered and how they have been evolving over time. This study was carried out to establish the characteristics of observed flood events in the past across Europe in terms of their spatial extent and the processes leading up to the events using a process based hydrological model. To this end, daily discharge data from more than 750 stations of the Global Runoff Data Center were used to identify flood events at the stations based on a threshold method for the period 1961-2010. The identified events at the different stations were further analyzed to determine whether they form the same flood event, thereby delineating the spatial extent of the flood events. The pan-European hydrological model, E-HYPE, which runs at a daily time step, was employed to estimate a set of catchment hydrological and hydro-meteorological state variables that are relevant in the flood generating process for each of the identified spatially delineated flood events. A subsequent clustering of the events based on the simulated state variables, together with the spatial extent of the flood events, was used to identify the flood generating mechanism of each flood event. Four general flood generation mechanisms were identified: long-rain flood, short-rain flood, snowmelt flood, and rain-on-snow flood. A trend analysis was performed to investigate how the frequency of each of the flood types has changed over time. In order to investigate whether there is a regional and seasonal pattern in the dominant flood generating mechanisms, this analysis was performed separately for winter and summer seasons and three different regions of Europe: Northern, Western, and Eastern Europe. The results show a regional difference both in the dominant flood generating mechanism and the corresponding trends.

  15. Potential Hazards of Tsunami Waves along the Chinese coast in the next 100 years

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Yuen, D. A.; Sevre, E. O.; Shi, Y.

    2007-12-01

    In the next 100 years the Chinese coast faces potentially non-negligible danger from tsunamogenic earthquakes originating at the neighboring subducting plate boundaries in the Phillipines and the Ryukyu Islands. There are significant differences in the bottom bathymetry between the South China Sea bordering the southern province of Guangdong and the East China Sea and Yellow Sea adjacent to the provinces of Zhejiang, Jiangsu, and Shandong. We have found that the linear shallow-water equations can be used to predict with good enough accuracy the travel time of tsunami waves in the South China Sea, but the nonlinear shallow-water equations must be used for the shallower seas next to the northern Chinese provinces. There are some differences in the travel time predictions between the linear and nonlinear theories for the Yellow Sea region. This difference is enough to make a difference in terms of warning. We will use our newly developed probability method, called the probabilistic forecast of tsunami hazards ( PFTH ) for predicting the danger of tsunami waves with a certain height of around 2 meters to impinge on the cities along the Chinese coast in the next century.We have used the Gutenberg-Richter relationship applied locally to each locale for evaluating the probability of the seismic risk for large earthquakes, greater than magnitude 7. We have only included the frequency of shallow large earthquakes to take place . For the southern cities of Hong Kong and Macau, we found that the probability of a 2 meter wave to hit these ports is around 10 % in the next century. Cities in Taiwan are less vulnerable than the large coastal cities on the Chinese mainland. The probability results for the northern cities of Shanghai and Qingdao are around a few per cent for smaller wave heights like one meter or so. But even these smaller waves can be damaging --

  16. The Archives of the Department of Terrestrial Magnetism: Documenting 100 Years of Carnegie Science

    NASA Astrophysics Data System (ADS)

    Hardy, S. J.

    2005-12-01

    The archives of the Department of Terrestrial Magnetism (DTM) of the Carnegie Institution of Washington document more than a century of geophysical and astronomical investigations. Primary source materials available for historical research include field and laboratory notebooks, equipment designs, plans for observatories and research vessels, scientists' correspondence, and thousands of expedition and instrument photographs. Yet despite its history, DTM long lacked a systematic approach to managing its documentary heritage. A preliminary records survey conducted in 2001 identified more than 1,000 linear feet of historically-valuable records languishing in dusty, poorly-accessible storerooms. Intellectual control at that time was minimal. With support from the National Historical Publications and Records Commission, the "Carnegie Legacy Project" was initiated in 2003 to preserve, organize, and facilitate access to DTM's archival records, as well as those of the Carnegie Institution's administrative headquarters and Geophysical Laboratory. Professional archivists were hired to process the 100-year backlog of records. Policies and procedures were established to ensure that all work conformed to national archival standards. Records were appraised, organized, and rehoused in acid-free containers, and finding aids were created for the project web site. Standardized descriptions of each collection were contributed to the WorldCat bibliographic database and the AIP International Catalog of Sources for History of Physics. Historic photographs and documents were digitized for online exhibitions to raise awareness of the archives among researchers and the general public. The success of the Legacy Project depended on collaboration between archivists, librarians, historians, data specialists, and scientists. This presentation will discuss key aspects (funding, staffing, preservation, access, outreach) of the Legacy Project and is aimed at personnel in observatories, research

  17. To Humbly Go: Guarding Against Perpetuating Models of Colonization in the 100-Year Starship Study

    NASA Astrophysics Data System (ADS)

    Kramer, W. R.

    Past patterns of exploration, colonization and exploitation on Earth continue to provide the predominant paradigms that guide many space programs. Any project of crewed space exploration, especially of the magnitude envisioned by the 100-Year Starship Study, must guard against the hubris that may emerge among planners, crew, and others associated with the project, including those industries and bureaucracies that will emerge from the effort. Maintaining a non-exploitative approach may be difficult in consideration of the century of preparatory research and development and the likely multigenerational nature of the voyage itself. Starting now with mission dreamers and planners, the purpose of the voyage must be cast as one of respectful learning and humble discovery, not of conquest (either actual or metaphorical) or other inappropriate models, including military. At a minimum, the Study must actively build non-violence into the voyaging culture it is beginning to create today. References to exploitive colonization, conquest, destiny and other terms from especially American frontier mythology, while tempting in their propagandizing power, should be avoided as they limit creative thinking about alternative possible futures. Future voyagers must strive to adapt to new environments wherever possible and be assimilated by new worlds both biologically and behaviorally rather than to rely on attempts to recreate the Earth they have left. Adaptation should be strongly considered over terraforming. This paper provides an overview of previous work linking the language of colonization to space programs and challenges the extension of the myth of the American frontier to the Starship Study. It argues that such metaphors would be counter-productive at best and have the potential to doom long-term success and survival by planting seeds of social decay and self-destruction. Cautions and recommendations are suggested.

  18. 100 years of California’s water rights system: patterns, trends and uncertainty

    NASA Astrophysics Data System (ADS)

    Grantham, Theodore E.; Viers, Joshua H.

    2014-08-01

    For 100 years, California’s State Water Resources Control Board and its predecessors have been responsible for allocating available water supplies to beneficial uses, but inaccurate and incomplete accounting of water rights has made the state ill-equipped to satisfy growing societal demands for water supply reliability and healthy ecosystems. Here, we present the first comprehensive evaluation of appropriative water rights to identify where, and to what extent, water has been dedicated to human uses relative to natural supplies. The results show that water right allocations total 400 billion cubic meters, approximately five times the state’s mean annual runoff. In the state’s major river basins, water rights account for up to 1000% of natural surface water supplies, with the greatest degree of appropriation observed in tributaries to the Sacramento and San Joaquin Rivers and in coastal streams in southern California. Comparisons with water supplies and estimates of actual use indicate substantial uncertainty in how water rights are exercised. In arid regions such as California, over-allocation of surface water coupled with trends of decreasing supply suggest that new water demands will be met by re-allocation from existing uses. Without improvements to the water rights system, growing human and environmental demands portend an intensification of regional water scarcity and social conflict. California’s legal framework for managing its water resources is largely compatible with needed reforms, but additional public investment is required to enhance the capacity of the state’s water management institutions to effectively track and regulate water rights.

  19. Contribution of insurance data to cost assessment of coastal flood damage to residential buildings: insights gained from Johanna (2008) and Xynthia (2010) storm events

    NASA Astrophysics Data System (ADS)

    André, C.; Monfort, D.; Bouzit, M.; Vinchon, C.

    2013-08-01

    There are a number of methodological issues involved in assessing damage caused by natural hazards. The first is the lack of data, due to the rarity of events and the widely different circumstances in which they occur. Thus, historical data, albeit scarce, should not be neglected when seeking to build ex-ante risk management models. This article analyses the input of insurance data for two recent severe coastal storm events, to examine what causal relationships may exist between hazard characteristics and the level of damage incurred by residential buildings. To do so, data was collected at two levels: from lists of about 4000 damage records, 358 loss adjustment reports were consulted, constituting a detailed damage database. The results show that for flooded residential buildings, over 75% of reconstruction costs are associated with interior elements, with damage to structural components remaining very localised and negligible. Further analysis revealed a high scatter between costs and water depth, suggesting that uncertainty remains high in drawing up damage functions with insurance data alone. Due to the paper format of the loss adjustment reports, and the lack of harmonisation between their contents, the collection stage called for a considerable amount of work. For future events, establishing a standardised process for archiving damage information could significantly contribute to the production of such empirical damage functions. Nevertheless, complementary sources of data on hazards and asset vulnerability parameters will definitely still be necessary for damage modelling; multivariate approaches, crossing insurance data with external material, should also be investigated more deeply.

  20. Constraining sediment dynamics during flood events using fallout radionuclides (Be-7 and Pb-210(xs)): a pilot study in a tropical catchment of SE Asia

    NASA Astrophysics Data System (ADS)

    Gourdin, Elian; Evrard, Olivier; Huon, Sylvain; Lefèvre, Irène; Ayrault, Sophie; Ribolzi, Olivier

    2013-04-01

    Soil erosion is particularly intense in mountainous subtropical regions where heavy storms result in the production of large quantities of suspended sediment, leading to both on-site and off-site siltation problems and conveying contaminants and biological compounds along streams. To implement efficient controls on sediment transfer, it is necessary to monitor suspended matter loads and determine whether sediments are directly exported from the catchment during a given flood or re-suspended from deposits left by previous floods. Determination of sediment residence time in catchments can be performed combining fallout radionuclides (Be-7, Pb-210 and Cs-137) measurements in both rainfall and suspended sediments, but prerequisites for their use as tracers during flood events are still required. We conducted experiments along a network of nested catchments with area increasing from 0.12 to 6.15 km², and sampled rainfall and suspended sediment loads during a flood that occurred at the beginning of the rainy season in May 2012. The experiment was carried out in the Houay Xon catchment, part of the MSEC (Multi-Scale Environmental Changes, http://msec3.net/portal/) project in the Northern Luang Prabang province of Laos. This catchment, under shifting cultivation since the end of the 1960s for a large part of its surface, is characterized by a steep topography (slopes ranging from 3% to 350% with a mean slope of 56%) and a land use evolution prone to gully erosion. The seasonal distribution of rainfall controls the Be-7 and Pb-210(xs) activities of soils in the catchment. With a half-life of 53 days, the fallout Be-7 activity of the previous wet season should have sufficiently decayed during the 6-months dry period to be neglected compared to new supply by early rains of the following wet season. Atmospheric deposition of Be-7 and Pb-210(xs) was measured after flocculation of rainfall samples by aluminum chloride hexahydrate and after dehydration of 75 suspended sediment

  1. Characterizing 13 Years of Surface Water Variability from MODIS-based Near Real-Time Flood Mapping Products in the Indus River, Tonle Sap Lake, and Lake Chad.

    NASA Astrophysics Data System (ADS)

    Slayback, D. A.; Brakenridge, G. R.; Policelli, F. S.

    2015-12-01

    Driven by an increase in extreme weather events in a warming world, flooding appears to be increasing in many regions. Since 2012, we have been using the twice-daily near-global observations of the two MODIS instruments to operate a near real-time flood mapping capability. Primarily intended to support disaster response efforts, our system generates daily near-global maps of flood water extent, at 250 m resolution. Although cloud cover is a challenge, the twice-daily coverage from the Terra and Aqua satellites helps to capture most major events. We use the MOD44W product (the "MODIS 250-m land-water mask") to differentiate "normal" water from flood water. Products from the system are freely available, and used by disaster response agencies and academic and industry researchers. An open question, however, is: how "normal" are recently observed floods? Destructive and — as reported by the press — record floods seem to be occurring more and more frequently. With the MODIS archive going back to 1999 (Terra satellite) and 2002 (Aqua satellite), we now have more than a decade of twice-daily near-global observations to begin answering this question. Although the 13 years of available twice-daily data (2002-2015) are not sufficient to fully characterize surface water normals (e.g., 100-year floods), we can start examining recent trends in surface water extent and flood frequency. To do so, we have back-processed our surface water product through mid-2002 (Aqua launch) for a few regions, and have used this to evaluate the variability in surface water extent and flood frequency. These results will eventually feed back into an improved characterization of flood water in our near real-time flood product. Here we will present results on trends in surface water extent and flood frequency for a few regions, including the Indus in Pakistan, the Tonle Sap lake in Cambodia, and lake Chad in Africa.

  2. Flooding disturbances increase resource availability and productivity but reduce stability in diverse plant communities.

    PubMed

    Wright, Alexandra J; Ebeling, Anne; de Kroon, Hans; Roscher, Christiane; Weigelt, Alexandra; Buchmann, Nina; Buchmann, Tina; Fischer, Christine; Hacker, Nina; Hildebrandt, Anke; Leimer, Sophia; Mommer, Liesje; Oelmann, Yvonne; Scheu, Stefan; Steinauer, Katja; Strecker, Tanja; Weisser, Wolfgang; Wilcke, Wolfgang; Eisenhauer, Nico

    2015-01-01

    The natural world is increasingly defined by change. Within the next 100 years, rising atmospheric CO₂ concentrations will continue to increase the frequency and magnitude of extreme weather events. Simultaneously, human activities are reducing global biodiversity, with current extinction rates at ~1,000 × what they were before human domination of Earth's ecosystems. The co-occurrence of these trends may be of particular concern, as greater biological diversity could help ecosystems resist change during large perturbations. We use data from a 200-year flood event to show that when a disturbance is associated with an increase in resource availability, the opposite may occur. Flooding was associated with increases in productivity and decreases in stability, particularly in the highest diversity communities. Our results undermine the utility of the biodiversity-stability hypothesis during a large number of disturbances where resource availability increases. We propose a conceptual framework that can be widely applied during natural disturbances. PMID:25600177

  3. Flood risk on the Black sea coast of Russia

    NASA Astrophysics Data System (ADS)

    Alekseevsky, Nikolay; Magritsky, Dmitry; Koltermann, Peter; Krylenko, Inna; Umina, Natalya; Aybulatov, Denis; Efremova, Natalya; Lebedeva, Seraphima

    2013-04-01

    The data of unique database "Floods in the coastal zones of Europeans part of Russia", developed by authors, are shown, that frequency of floods and damage in the coastal zones are growing. There is most dangerous situation on the Black sea coast of Russia. Here the main part of settlements, resorts and industry is situated in the river valleys and mouths. All main roads and pipelines cross the river channels. The Black sea rivers have flood regime with high intensity of flood formations and huge destructive flood power. Despite prevalence of floods during the cold period of year the most part of high floods in 100 years of supervision was noted here in the summer-fall (65% in July-October). Usually they were induced by the showers connected with passing of powerful cyclones, atmospheric fronts, and water tornadoes. The insignificant part of floods was connected with snow melting, backwater phenomena, showers in the cities and dam breaks. Thus shower induced floods here are the most widespread and destructive. Usually they arise within two-three watersheds simultaneously. Formation catastrophic heavy rain flood is possible on any site of a river valley of the Black Sea coast. The wave of a high water moves with very high speed, carrying a large number of deposits and garbage. To the mouth the flood can be transformed into debris flow. The water levels during a high water period rise on 3-6 m in the channels, and up to 11-12 m in the river canyons; the maximum depths of flow on the floodplains are 3 m and more. Flooding depths, induced by slope streams, can be to 0,5 m and higher. Flooding proceeds only some hours. After that water rather quickly flows down from a floodplains to the bed of the rivers and into the sea, leaving traces of destructions, a powerful layer of deposits (to 10-20 cm and more) and garbage. In the mouth river deposits quite often form the river mouth bar which is washed away during next storms. The damage from river floods on the Black Sea

  4. Preparing for floods: flood forecasting and early warning

    NASA Astrophysics Data System (ADS)

    Cloke, Hannah

    2016-04-01

    Flood forecasting and early warning has continued to stride ahead in strengthening the preparedness phases of disaster risk management, saving lives and property and reducing the overall impact of severe flood events. For example, continental and global scale flood forecasting systems such as the European Flood Awareness System and the Global Flood Awareness System provide early information about upcoming floods in real time to various decisionmakers. Studies have found that there are monetary benefits to implementing these early flood warning systems, and with the science also in place to provide evidence of benefit and hydrometeorological institutional outlooks warming to the use of probabilistic forecasts, the uptake over the last decade has been rapid and sustained. However, there are many further challenges that lie ahead to improve the science supporting flood early warning and to ensure that appropriate decisions are made to maximise flood preparedness.

  5. Evaluation of the Relative Influence of Climate Variability and Human Activities on Flood Risk in Moderately Impaired Watersheds

    NASA Astrophysics Data System (ADS)

    Griffis, V. W.; Salvadori, N.

    2013-12-01

    Standard procedures for forecasting flood risk involve estimating the recurrence interval associated with observed annual maximum flood (AMF) events using an assumed theoretical probability distribution. The magnitude of a needed design event (i.e., the 100-year event) is then determined for use in floodplain delineation, land-use planning and management, design and operation of water-use and water-control structures, and design of transportation infrastructure such as bridges and roads. These procedures assume annual maximum flood series are stationary, meaning the distribution of flood flows is not significantly affected by climatic trends or cycles. Historical flood events are thus considered to be representative of future flood occurrences, and the flood risk associated with a given magnitude of flow is modeled as constant over time. This represents a significant limitation of current flood frequency models as results of previous studies indicate AMF series are non-stationary even in unimpaired watersheds. Moreover, as the majority of streams are located in areas of increasing human activity, relative and coupled impacts of natural and anthropogenic factors need to be considered such that non-stationary flood frequency models can be developed for flood risk forecasting over relevant planning horizons for large scale water resources planning and management. Large-scale climate patterns -- El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO) - have been identified as influencing factors on annual maximum flood series for a number of unimpaired watersheds throughout the US. In addition, strong correlation exists between the magnitude and timing of annual maximum flood peaks and leading precipitation and temperature series, respectively, for unimpaired sites within the Upper Midwest and Northeastern US. In this study, similar analyses are conducted to identify possible climatic/meteorological sources

  6. Preliminary estimation of the peak discharge at the Su Gologone spring (Central-East Sardinia) during the flood event of November 18th, 2013

    NASA Astrophysics Data System (ADS)

    Cossu, Antonello; De Waele, Jo; Sanna, Francesco; Sanna, Laura

    2014-05-01

    Last November 2013, an exceptional rainfall has occurred in Sardinia causing 18 casualties at Olbia and Bitti and severe economic damage to infrastructures and land in many areas (e.g. Torpè and Cedrino plains). From a meteorological point of view, this rainfall event was caused by south-western warm and humid air currents moving from Africa coming in contact with cold air masses located above the higher parts of the island, creating convective phenomena of a certain intensity. Estimating the peak discharge of the rivers related to these high intensity rainfall events is of fundamental importance to improve flood-risk management and to prevent and/or reduce the damages. In carbonate areas, quantifying the karst aquifer recharge is an even more difficult task due to the fact that the precipitation and resulting surface flow is rapidly transferred to the underground cave systems, and then suddenly released at karst outflows. We report the case of the Su Gologone spring, in Supramonte area (Central-East Sardinia, Italy), a karst resurgence located only twenty metres from the Cedrino river and one of the main water supplies to this river. The freshwater of this karst spring feeds the Preda 'e Othoni dam, located a few kilometres downstream of the resurgence, and originally built to regulate the flooding of Cedrino river but currently used for all sorts of purposes, as electricity supply, irrigation of farmlands, industrial uses and especially for drinking water, an important source that has to be quantified and preserved. With the purpose of evaluating the contribution of this karst spring to the river discharge, at the beginning of the hydrological year 2013-14, Su Gologone has been equipped with a multi-parametric probe for in-continuous monitoring, at regular intervals, of the values of pressure (and therefore the level of water), electrical conductivity and water temperature. During the entire monitoring period flow rate measurements have been performed three

  7. Infrared survey of 50 buildings constructed during 100 years: thermal performances and damage conditions

    NASA Astrophysics Data System (ADS)

    Ljungberg, Sven-Ake

    1995-03-01

    Different building constructions and craftsmanship give rise to different thermal performance and damage conditions. The building stock of most industrial countries consists of buildings of various age, and constructions, from old historic buildings with heavy stone or wooden construction, to new buildings with heavy or light concrete construction, or modern steel or wooden construction. In this paper the result from a detailed infrared survey of 50 buildings from six Swedish military camps is presented. The presentation is limited to a comparison of thermal performance and damage conditions of buildings of various ages, functions, and constructions, of a building period of more than 100 years. The result is expected to be relevant even to civilian buildings. Infrared surveys were performed during 1992-1993, with airborne, and mobile short- and longwave infrared systems, out- and indoor thermography. Interpretation and analysis of infrared data was performed with interactive image and analyzing systems. Field inspections were carried out with fiber optics system, and by ocular inspections. Air-exchange rate was measured in order to quantify air leakages through the building envelope, indicated in thermograms. The objects studied were single-family houses, barracks, office-, service-, school- and exercise buildings, military hotels and restaurants, aircraft hangars, and ship factory buildings. The main conclusions from this study are that most buildings from 1880 - 1940 have a solid construction with a high quality of craftsmanship, relatively good thermal performance, due to extremely thick walls, and adding insulation at the attic floor. From about 1940 - 1960 the quality of construction, thermal performance and craftsmanship seem to vary a lot. Buildings constructed during the period of 1960 - 1990 have in general the best thermal performance due to a better insulation capacity, however, also one finds here the greatest variety of problems. The result from this

  8. Climatic and Hydrological Changes of Past 100 Years in Asian Arid Zone

    NASA Astrophysics Data System (ADS)

    Feng, Zhaodong; Salnikov, Vitaliy; Xu, Changchun

    2014-05-01

    The Asian Arid Zone (AAZ) is here defined to include the following regions: northwestern China, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. Generally speaking, the AAZ has experienced a temperature rising during the past 100 years that was significantly faster than the global average (0.14 ºC per decade). Specifically, the rate was 0.39 ºC per decade in northwestern China (1950-2010), 0.26 ºC per decade in Kazakhstan (1936-2005), 0.22 ºC per decade in Mongolia (1940-2010), 0.29 ºC per decade in Uzbekistan (1950-2005), 0.18 ºC per decade in Turkmenistan (1961-1995). It should be noted that the mountainous parts of AAZ seems to have experienced a slower rate of temperature rising. For example, the rate was 0.10 ºC per decade in Tajikistan (1940-2005) and was 0.08 ºC per decade in Kyrgyzstan (1890-2005). Precipitation has a slight increasing trend in northwestern China, but it has fluctuated along a near-constant line in the rest of the AAZ. Hydrological data from high-elevation basin show that the runoff has been increasing primarily as a result of rising temperature that caused increases in ice melting. A natural decreasing trend of surface runoff in low-elevation basins is undeniable and the decreasing trend is attributable to intensified evaporation under warming conditions. It is true that the total amount of runoff in the Tianshan Mountains and the associated basins has been increased primarily as a result of temperature rising-resulted increases in ice melting. But, approaching to the turning point of glacier-melting supplies to runoff will pose a great threat to socio-economic sustainability and to ecological security. The turning point refers to the transition from increasing runoff to decreasing runoff within ice melting supplied watersheds under a warming climate.

  9. Flood Hazard Mapping Assessment for El-Awali River Catchment-Lebanon

    NASA Astrophysics Data System (ADS)

    Hdeib, Rouya; Abdallah, Chadi; Moussa, Roger; Hijazi, Samar

    2016-04-01

    River flooding prediction and flood forecasting has become an essential stage in the major flood mitigation plans worldwide. Delineation of floodplains resulting from a river flooding event requires coupling between a Hydrological rainfall-runoff model to calculate the resulting outflows of the catchment and a hydraulic model to calculate the corresponding water surface profiles along the river main course. In this study several methods were applied to predict the flood discharge of El-Awali River using the available historical data and gauging records and by conducting several site visits. The HEC-HMS Rainfall-Runoff model was built and applied to calculate the flood hydrographs along several outlets on El-Awali River and calibrated using the storm that took place on January 2013 and caused flooding of the major Lebanese rivers and by conducting additional site visits to calculate proper river sections and record witnesses of the locals. The Hydraulic HEC-RAS model was then applied to calculate the corresponding water surface profiles along El-Awali River main reach. Floodplain delineation and Hazard mapping for 10,50 and 100 years return periods was performed using the Watershed Modeling System WMS. The results first show an underestimation of the flood discharge recorded by the operating gauge stations on El-Awali River, whereas, the discharge of the 100 years flood may reach up to 506 m3/s compared by lower values calculated using the traditional discharge estimation methods. Second any flooding of El-Awali River may be catastrophic especially to the coastal part of the catchment and can cause tragic losses in agricultural lands and properties. Last a major floodplain was noticed in Marj Bisri village this floodplain can reach more than 200 meters in width. Overall, performance was good and the Rainfall-Runoff model can provide valuable information about flows especially on ungauged points and can perform a great aid for the floodplain delineation and flood

  10. Developing an Approach to Prioritize River Restoration using Data Extracted from Flood Risk Information System Databases.

    NASA Astrophysics Data System (ADS)

    Vimal, S.; Tarboton, D. G.; Band, L. E.; Duncan, J. M.; Lovette, J. P.; Corzo, G.; Miles, B.

    2015-12-01

    Prioritizing river restoration requires information on river geometry. In many states in the US detailed river geometry has been collected for floodplain mapping and is available in Flood Risk Information Systems (FRIS). In particular, North Carolina has, for its 100 Counties, developed a database of numerous HEC-RAS models which are available through its Flood Risk Information System (FRIS). These models that include over 260 variables were developed and updated by numerous contractors. They contain detailed surveyed or LiDAR derived cross-sections and modeled flood extents for different extreme event return periods. In this work, over 4700 HEC-RAS models' data was integrated and upscaled to utilize detailed cross-section information and 100-year modelled flood extent information to enable river restoration prioritization for the entire state of North Carolina. We developed procedures to extract geomorphic properties such as entrenchment ratio, incision ratio, etc. from these models. Entrenchment ratio quantifies the vertical containment of rivers and thereby their vulnerability to flooding and incision ratio quantifies the depth per unit width. A map of entrenchment ratio for the whole state was derived by linking these model results to a geodatabase. A ranking of highly entrenched counties enabling prioritization for flood allowance and mitigation was obtained. The results were shared through HydroShare and web maps developed for their visualization using Google Maps Engine API.

  11. Intermittent spring flooding of agricultural fields will increase net global-warming potential of greenhouse gas fluxes

    NASA Astrophysics Data System (ADS)

    Paul, R. F.; Smyth, E. M.; Smith, C. M.; Kantola, I. B.; Krichels, A.; Yang, W. H.; DeLucia, E. H.

    2014-12-01

    The U.S. Corn Belt is currently a net source of carbon dioxide and nitrous dioxide to the atmosphere but is also a weak sink for methane. Climate change is projected to increase the frequency and duration of spring precipitation in the North American Midwest, resulting in intermittent flooding and ponding in agricultural fields. Inundation changes the greenhouse gas (GHG) fluxes of the soil, especially by promoting methanogenesis under anoxic conditions. DNA and 16S cDNA sequencing results of earlier, similar experiments confirmed the presence of methanogens in soil samples, albeit in low abundance (representing <0.01% of reads per sample). We installed collars into bare ground of a central Illinois research field to experiment with flooding conditions and observe changes in gas fluxes, microbial community, and soil chemistry. We established three treatments of five replicates—control, continuously flooded, and intermittently flooded—each with separate collars for gas flux measurements, soil sample collection, and soil probe measurements. A drip irrigation system flooded the headspaces of the collars to produce flooding events. The continuously flooded collars were maintained in a flooded condition for the duration of the experiment, and the intermittently flooded collars were flooded for 72 hours per flooding event and then kept dry for at least 5 days before the next flooding event. We measured net concentrations of N2O, CH4, and CO2 in situ using a static chamber connected to a cavity ringdown spectrometer. We found that the periodicity of wetting and drying events induces hysteresis effects that push GHG shifts to occur rapidly (< 1 hr). Integrating fluxes across the period of the experiment, the intermittently flooded collars showed 88.7% higher global-warming potential of GHG fluxes at the 100-year horizon versus control, with most of change driven by increased net CO2 flux (87.1% higher) and net methane flux (29 times higher). These data indicate that

  12. Popular myths about flooding in Western Washington

    USGS Publications Warehouse

    Jones, Joseph L.

    2011-01-01

    Floods are the most destructive natural hazard in the Nation, causing more deaths and financial loss in the 20th century than any other natural disaster. The most significant 20 riverine floods of the 20th century for which data are available have killed more than 1,843 people and caused more than $50 billion (uninflated) in damages (Perry, 2000). One of the most common means of describing the severity of a flood is a comparison to the "100-year flood." In the last decade, increasing attention has been paid to the fact that some regions, notably the Pacific Northwest, have experienced numerous so-called "100-year" floods in the span of a few years. Part of the confusion stems from the statistical nature of the "100-year flood" (Greene, 1996); however, another part of the confusion is the fact that the statistics are calculated for specific sites (streamgages) on specific rivers, rather than for a region as a whole. Scientists with the U.S. Geological Survey have begun to investigate how the likelihood of flooding may be determined on a regional basis (Troutman and Karlinger, 2003).

  13. Nogales flood detention study

    USGS Publications Warehouse

    Norman, Laura M.; Levick, Lainie; Guertin, D. Phillip; Callegary, James; Guadarrama, Jesus Quintanar; Anaya, Claudia Zulema Gil; Prichard, Andrea; Gray, Floyd; Castellanos, Edgar; Tepezano, Edgar; Huth, Hans; Vandervoet, Prescott; Rodriguez, Saul; Nunez, Jose; Atwood, Donald; Granillo, Gilberto Patricio Olivero; Ceballos, Francisco Octavio Gastellum

    2010-01-01

    Flooding in Ambos Nogales often exceeds the capacity of the channel and adjacent land areas, endangering many people. The Nogales Wash is being studied to prevent future flood disasters and detention features are being installed in tributaries of the wash. This paper describes the application of the KINEROS2 model and efforts to understand the capacity of these detention features under various flood and urbanization scenarios. Results depict a reduction in peak flow for the 10-year, 1-hour event based on current land use in tributaries with detention features. However, model results also demonstrate that larger storm events and increasing urbanization will put a strain on the features and limit their effectiveness.

  14. Why Teach a 100-Year-Old Strike?: The "Bread and Roses" Centenary

    ERIC Educational Resources Information Center

    Diamond, Norm

    2012-01-01

    Today's movement in support of the 99 percent is a reminder that throughout U.S. history, a major engine of change has been grass-roots organizing and solidarity. Major history textbooks, however, downplay the role of ordinary people in shaping events--especially those who formed labor unions and used the strike to assert their rights. One of the…

  15. Flood Risk and Global Change: Future Prospects

    NASA Astrophysics Data System (ADS)

    Serra-Llobet, A.

    2014-12-01

    Global flood risk is increasing in response to population growth in flood-prone areas, human encroachment into natural flood paths (exacerbating flooding in areas formerly out of harm's way), and climate change (which alters variables driving floods). How will societies respond to and manage flood risk in coming decades? Analysis of flood policy evolution in the EU and US demonstrates that changes occurred in steps, in direct response to disasters. After the flood produced by the collapse of Tous Dam in 1982, Spain initiated a systematic assessment of areas of greatest flood risk and civil protection response. The devastating floods on the Elbe and elsewhere in central Europe in 2002 motivated adoption of the EU Floods Directive (2007), which requires member states to develop systematic flood risk maps (now due) and flood risk management plans (due in 2015). The flooding of New Orleans by Hurricane Katrina in 2005 resulted in a nationwide levee-safety assessment and improvements in communicating risk, but overall less fundamental change in US flood management than manifest in the EU since 2007. In the developing world, large (and increasing) concentrations of populations in low-lying floodplains, deltas, and coasts are increasingly vulnerable, and governments mostly ill-equipped to implement fundamental changes in land use to prevent future increases in exposure, nor to develop responses to the current threats. Even in the developed world, there is surprisingly little research on how well residents of flood-prone lands understand their true risk, especially when they are 'protected' by '100-year' levees. Looking ahead, researchers and decision makers should prioritize improvements in flood risk perception, river-basin-scale assessment of flood runoff processes (under current and future climate and land-use conditions) and flood management alternatives, and bridging the disconnect between national and international floodplain management policies and local land

  16. Flood plain analysis for Petris, , Troas, and Monoros, tia watersheds, the Arad department, Romania

    NASA Astrophysics Data System (ADS)

    Győri, M.-M.; Haidu, I.

    2012-04-01

    water surface TIN is generated and intersected with the DEM in order to create the flood plain polygons. The final result consists of the flood plain delineation and the water inundation depths for the 10, 50 and 100 year return period flood events. These could be further employed in a risk assessment. Key words : flood plain analysis, frequency analysis, HEC-HMS, HEC-RAS. Aknowledgements This work was possible with the financial support of the Sectoral Operational Programme for Human Resources Development 2007-2013, co-financed by the European Social Fund, under the project number POSDRU/107/1.5/S/76841 with the title "Modern Doctoral Studies: Internationalization and Interdisciplinarity".

  17. Influence of a flood event on salinity and nutrients in the Changshan Archipelago area (Northern Yellow Sea)

    NASA Astrophysics Data System (ADS)

    Zhang, Guangtao; Zhao, Zengxia; Liu, Changhua; Liu, Qun; Ren, Jianming

    2012-09-01

    River discharge can deliver nutrients to the coastal zone and change the hydrologic properties of the water column. Soon after a flash flood from the Yalu River (Northeast China) in August 2010, we investigated the salinity and nutrient concentrations, as well as other environmental conditions in the Changshan Archipelago area, located approximately 100 km west of the river mouth in the northern Yellow Sea. Diluted water was mainly observed in the upper layers shallower than 15 m, with surface salinity between 18.13 and 30.44 in the eastern study area and between 28.16 and 29.72 in the western area. Surface salinity showed a significant negative correlation with concentrations of dissolved nutrients ( P < 0.05), but not with that of Chlorophyll- a (Chl- a), dissolved oxygen (DO), particulate materials or pH. The average concentrations of nitrite, nitrate, and silicic acid decreased from the surface layer to bottom layer and were significantly higher in the east area than in the west area ( P < 0.05). In contrast, average ammonium and phosphate concentrations were highest in the bottom layer of both areas, with no significant spatial differences. DO varied between 6.06 and 8.25 mg L-1 in the surface layer, and was significantly higher in the eastern area than in the western area in the surface and middle layers. Chl- a concentration was constantly below 4.09 μg L-1. Our work demonstrated the strong influences of Yalu River on proportions of various nutrient components in the Changshan Archipelago area. Silicic acid and total inorganic nitrogen levels were significantly elevated comparing to phosphate in the eastern area. Such changes can potentially induce phosphate limit to phytoplankton growth.

  18. Climatic variability and flood frequency of the Santa Cruz River, Pima County, Arizona

    USGS Publications Warehouse

    Webb, Robert H.; Betancourt, Julio L.

    1992-01-01

    Past estimates of the 100-year flood for the Santa Cruz River at Tucson, Arizona, range from 572 to 2,780 cubic meters per second. An apparent increase in flood magnitude during the past two decades raises concern that the annual flood series is nonstationary in time. The apparent increase is accompanied by more annual floods occurring in fall and winter and fewer in summer. This greater mixture of storm types that produce annual flood peaks is caused by a higher frequency of meridional flow in the upper-air circulation and increased variance of ocean-atmosphere conditions in the tropical Pacific Ocean. Estimation of flood frequency on the Santa Cruz River is complicated because climate affects the magnitude and frequency of storms that cause floods. Mean discharge does not change significantly, but the variance and skew coefficient of the distribution of annual floods change with time. The 100-year flood during El Niffo-Southern Oscillation conditions is 1,300 cubic meters per second, more than double the value for other years. The increase is mostly caused by an increase in recurvature of dissipating tropical cyclones into the Southwestern United States during El Niffo-Southern Oscillation conditions. Flood frequency based on hydroclimatology was determined by combining populations of floods caused by monsoonal storms, frontal systems, and dissipating tropical cyclones. For 1930-59, annual flood frequency is dominated by monsoonal floods, and the estimated 100-year flood is 323 cubic meters per second. For 1960-86, annual flood frequency at recurrence intervals of greater than 10 years is dominated by floods caused by dissipating tropical cyclones, and the estimated 100-year flood is 1,660 cubic meters per second. For design purposes, 1,660 cubic meters per second might be an appropriate value for the 100-year flood at Tucson, assuming that climatic conditions during 1960-86 are representative of conditions expected in the immediate future.

  19. The flood of December 1982 and the 100- and 500-year flood on the Buffalo River, Arkansas

    USGS Publications Warehouse

    Neely, B.L.

    1985-01-01

    Flood profiles, peak discharges, and stages were determined for the December 1982, the 100-year, and the 500-year floods at 17 sites along the Buffalo River, Arkansas. Typical synthetic stage hydrographs for the 100- and 500-year floods were determined for each site. Flow duration data for gaging stations at St. Joe and Rush are shown. The average velocity of the water for the 100- and 500-year floods is shown for each site. Approximate flood boundaries delineating the 100- and 500-year floods are shown for Ponca, Steel Creek, Pruitt, St. Joe, and Buffalo Point. (Author 's abstract)

  20. Intense drought and flooding events in the Rio Negro and relation with the tropical Pacific and Atlantic variability modes

    NASA Astrophysics Data System (ADS)

    Andreoli, Rita Valéria; da Silva, Simone Nazaré Rodriguez; de Souza, Rodrigo Augusto Ferreira; Kayano, Mary Toshie; Garcia, Sâmia Regina; Capistrano, Vinícius Buscioli; Armijos, Elisa

    2016-04-01

    The relationship of the hydrological variability of the Rio Negro in Manaus and the dominant large-scale climate variability patterns for the 1902-2007 period is investigated using the quantile method and composite analyses. Variations of the Rio Negro Level (RNL) during its 3-month high (May to July—MJJ) and low (October to December—OND) phases are examined separately. The El Niño (La Niña) related maximum warming (cooling) in the central tropical Pacific during its mature and decaying stages modulates the atmospheric circulation in the tropics and displaces the Walker circulation cell eastward (westward), so that its sinking (rising) branch occurs over western Amazon and causes negative (positive) precipitation anomalies in this region. These anomalous climate conditions occur before the Rio Negro high phase (MJJ) and contribute to reduce (increase) the RNL and lead to a very low (very high) event in the river. On the other hand, the SST variability modes in the tropical Atlantic mainly during the transition from wet to dry season modulate the precipitation variations over western Amazon in OND. The very high events are more frequent after the 1960's decade and the very low events, before the 1930's decade. Therefore, the occurrence of these events contains a multidecadal scale variability. The results also indicate that the variations in the rainfall in western Amazon occur up to 9 months in advance and modulate the RNL in Manaus. The results presented here might be useful for monitoring purposes of the RNL.

  1. Swiss Re Global Flood Hazard Zones: Know your flood risk

    NASA Astrophysics Data System (ADS)

    Vinukollu, R. K.; Castaldi, A.; Mehlhorn, J.

    2012-12-01

    Floods, among all natural disasters, have a great damage potential. On a global basis, there is strong evidence of increase in the number of people affected and economic losses due to floods. For example, global insured flood losses have increased by 12% every year since 1970 and this is expected to further increase with growing exposure in the high risk areas close to rivers and coastlines. Recently, the insurance industry has been surprised by the large extent of losses, because most countries