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Sample records for 100-year flood discharge

  1. 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)

  2. 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

  3. 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.

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  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. Flood discharges in the upper Mississippi River basin, 1993

    USGS Publications Warehouse

    Parrett, Charles; Melcher, Nick B.; James, Robert W., Jr.

    1993-01-01

    Flood-peak discharges that equaled or exceeded the 10-year recurrence interval were recorded at 154 streamflow-gaging stations in the upper Mississippi River Basin. At 41 streamflowgaging stations, the peak discharge was greater than the previous maximumknown discharge. At 15 additional gaging stations, peak discharges exceeded the previous maximum regulated peak discharge. At 45 gaging stations, peak discharges exceeded 100-year recurrence intervals.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. Flood discharge measurement of mountain rivers

    NASA Astrophysics Data System (ADS)

    Chen, Y.-C.

    2012-11-01

    An efficient method that accounts for personal safety, accuracy and reliability for measuring flood discharge of mountain rivers is proposed. It is composed of new measurement method, tools, and techniques. Measuring flood discharge from mountain rivers by using conventional method is costly, time-consuming, and dangerous. Thus previous discharge measurements for mountainous areas were typically based on estimated precipitation, which alone cannot generate accurate measurements. This study applies a novel flood discharge measurement system composed of an Acoustic Doppler Profiler and crane system to accurately and quickly measure velocity distributions and water depths. Moreover a novel and efficient method for measuring discharge, which is based on the relationship between mean and maximum velocities and the relationship between cross-sectional area and gauge height is applied to estimate flood discharge. Flood discharge from mountain rivers can be estimated easily and rapidly by measuring maximum velocity in the river crosssection and the gauge height. The measured flood discharges can be utilized to create a reliable stage-discharge relationship for continuous estimations of discharge using records of water stage. The proposed method was applied to the Nanshih River, Taiwan. Results of measured discharges and estimated discharges only slightly differed from each other, demonstrating the efficiency and accuracy of the proposed method.

  17. Methods for estimating peak discharge and flood boundaries of streams in Utah

    USGS Publications Warehouse

    Thomas, B.E.; Lindskov, K.L.

    1983-01-01

    Equations for estimating 2-, 5-, 10-, 25-, 50-, and 100-year peak discharges and flood depths at ungaged sites in Utah were developed using multiple-regression techniques. Ratios of 500- to 100-year values also were determined. The peak discharge equations are applicable to unregulated streams and the flood depth equations are applicable to the unregulated flow in natural stream channels. The flood depth data can be used to approximate flood prone areas. Drainage area and mean basin elevation are the two basin characteristics needed to use these equations. The standard error of estimate ranges from 38% to 74% for the 100-year peak discharge and from 23% to 33% for the 100-year flood depth. Five different flood mapping methods are described. Streams are classified into four categories as a basis for selecting a flood mapping method. Procedures for transferring flood depths obtained from the regression equations to a flood boundary map are outlined. Also, previous detailed flood mapping by government agencies and consultants is summarized to assist the user in quality control and to minimize duplication of effort. Methods are described for transferring flood frequency data from gaged to ungaged sites on the same stream. Peak discharge and flood depth frequency relations and selected basin characteristics data, updated through the 1980 water year, are tabulated for more than 300 gaging stations in Utah and adjoining states. In addition, weighted estimates of peak discharge relations based on the station data and the regression estimates are provided for each gaging station used in the regression analysis. (Author 's abstract)

  18. Quantifying peak discharges for historical floods

    USGS Publications Warehouse

    Cook, J.L.

    1987-01-01

    It is usually advantageous to use information regarding historical floods, if available, to define the flood-frequency relation for a stream. Peak stages can sometimes be determined for outstanding floods that occurred many years ago before systematic gaging of streams began. In the United States, this information is usually not available for more than 100-200 years, but in countries with long cultural histories, such as China, historical flood data are available at some sites as far back as 2,000 years or more. It is important in flood studies to be able to assign a maximum discharge rate and an associated error range to the historical flood. This paper describes the significant characteristics and uncertainties of four commonly used methods for estimating the peak discharge of a flood. These methods are: (1) rating curve (stage-discharge relation) extension; (2) slope conveyance; (3) slope area; and (4) step backwater. Logarithmic extensions of rating curves are based on theoretical plotting techniques that results in straight line extensions provided that channel shape and roughness do not change significantly. The slope-conveyance and slope-area methods are based on the Manning equation, which requires specific data on channel size, shape and roughness, as well as the water-surface slope for one or more cross-sections in a relatively straight reach of channel. The slope-conveyance method is used primarily for shaping and extending rating curves, whereas the slope-area method is used for specific floods. The step-backwater method, also based on the Manning equation, requires more cross-section data than the slope-area ethod, but has a water-surface profile convergence characteristic that negates the need for known or estimated water-surface slope. Uncertainties in calculating peak discharge for historical floods may be quite large. Various investigations have shown that errors in calculating peak discharges by the slope-area method under ideal conditions for

  19. Technique for estimating flood-peak discharges and frequencies on rural streams in Illinois

    USGS Publications Warehouse

    Curtis, G.W.

    1987-01-01

    Flood-peak discharges and frequencies are presented for 394 gaged sites in Illinois, Indiana, and Wisconsin for recurrence intervals ranging from 2 to 100 years. A technique is presented for estimating flood-peak discharges at recurrence intervals ranging from 2 to 500 years for nonregulated streams in Illinois with drainage areas ranging from 0.02 to 10,000 square miles. Multiple-regression analyses, using basin characteristics and peak streamflow data from 268 of the 394 gaged sites, were used to define the flood-frequency relation. The most significant independent variables for estimating flood-peak discharge are drainage area, slope, rainfall intensity and a regional factor. Examples are given to show a step-by-step procedure in calculating a 50-year flood for a site on an ungaged stream, a site at a gaged location, and a site near a gaged location. (USGS)

  20. Effects of urban flood-detention reservoirs on peak discharges in Gwinnett County, Georgia

    USGS Publications Warehouse

    Hess, G.W.; Inman, E.J.

    1994-01-01

    The effects of flood-detention reservoirs on peak discharges along downstream reaches in six urban drainage basins in Gwinnett County, Georgia, were studied during 1986-93 using the U.S. Geological Survey's Distributed Routing Rainfall-Runoff Model (DR3M). Short-term rainfall-runoff data were collected at selected stations in six urban drainage basins in Gwinnett County. The basins range in size from 0.10 to 0.37 square miles and contain from 15- to 35- percent impervious areas. Each basin contains from two to six flood-detention reservoirs. The DR3M was calibrated using short-term rainfall-runoff data collected (1986-92) at each station. The model then was used to simulate long-term (1898-1980) peak discharges for these stations for conditions representing various amounts of detention ranging from the existing condition with all flood-detention reservoirs in place to the natural condition with no reservoirs. Flood-frequency relations were developed from the simulated annual peak discharges for each of these conditions by fitting the logarithms of the annual peak discharge data to a Pearson type III distribution curve. The effect of each flood-detention reservoir on peak discharges downstream was determined by comparison of peak discharges simulated with and without the flood-detention reservoirs. The cumulative effect of all flood-detention reservoirs in a basin on peak discharges downstream was determined by comparison of peak discharges for a flood with a given recurrence interval simulated with and without the reservoirs. Results of these comparisons indicate that removal of an individual flood-detention reservoir during simulations changes peak discharges from - 1 to 24 percent for the 2-year recurrence interval, from - 1 to 27 percent for the 10-year recurrence interval, and from -2 to 31 percent for the 100-year recurrence interval. The cumulative effect of removing all of the reservoirs from each of the six basins during simulation increases peak discharges

  1. Floods in Iowa: Stage and discharge

    USGS Publications Warehouse

    Lara, O.G.; Eash, D.A.

    1987-01-01

    This report presents stations descriptions and tables of peak stages and discharges for 280 continuous- and partial-record gaging stations in Iowa. Data for the annual flood series for each gaging station and partial-duration series, at stations where available, are contained in the report.

  2. 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.

  3. Effects of urban flood-detention reservoirs on peak discharges and flood discharges and flood frequencies, and simulation of flood-detention reservoir outflow hydrographs in two watersheds in Albany, Georgia

    USGS Publications Warehouse

    Hess, G.W.; Inman, E.J.

    1994-01-01

    This report describes the effects of flood-detention reservoirs on downstream peak discharges of two urban tributaries to Kinchafoonee Creek (tributaries 1 and 2) in Albany, Georgia and presents simulated flood-detention reservoir outflow hydrographs. Rainfall-runoff data were collected for six years at two stations in these two urban watersheds. Tributary number 1 basin has a drainage area of 0.12 square miles, contains 23.8 percent impervious area, and contains two detention reservoirs. Tributary number 2 basin has a drainage area of 0.09 square miles, contains 12.9 percent impervious area, and has one detention reservoir. The Distributed Routing Rainfall-Runoff Model (DR3M) was calibrated using rainfall-runoff data collected during 1987- 92 at each station. DR3M was then used to simulate long-term (1906-33, 1941-73) peak discharges for these stations for conditions ranging from the existing condition with all detention reservoirs in place to the condition of no detention reservoirs. Flood-frequency relations based on the long-term peak discharges were developed for each simulation by fitting the logarithms of the annual peak discharge data to a Pearson type III distri- bution curve. The effect of detention reservoirs on peak discharge data to a Pearson type III distributio curve. The effect of detention reservoirs on peak discharges was determined by comparison of simulated flood-frequency peak discharges for conditions with and without the detention reservoirs. The comparisons indicated that the removal of flood-detention reservoirs from the tributary number 1 basin would increase the 10-, 50-, and 100-year peak discharges by 164 to 204 percent. Removal of the reservoir from tributary number 2 basin would increase these discharges by about 145 percent.

  4. Estimated flood peak discharges on Twin, Brock, and Lightning creeks, Southwest Oklahoma City, Oklahoma, May 8, 1993

    USGS Publications Warehouse

    Tortorelli, R.L.

    1996-01-01

    The flash flood in southwestern Oklahoma City, Oklahoma, May 8, 1993, was the result of an intense 3-hour rainfall on saturated ground or impervious surfaces. The total precipitation of 5.28 inches was close to the 3-hour, 100-year frequency and produced extensive flooding. The most serious flooding was on Twin, Brock, and Lightning Creeks. Four people died in this flood. Over 1,900 structures were damaged along the 3 creeks. There were about $3 million in damages to Oklahoma City public facilities, the majority of which were in the three basins. A study was conducted to determine the magnitude of the May 8, 1993, flood peak discharge in these three creeks in southwestern Oklahoma City and compare these peaks with published flood estimates. Flood peak-discharge estimates for these creeks were determined at 11 study sites using a step-backwater analysis to match the flood water-surface profiles defined by high-water marks. The unit discharges during peak runoff ranged from 881 cubic feet per second per square mile for Lightning Creek at SW 44th Street to 3,570 cubic feet per second per square mile for Brock Creek at SW 59th Street. The ratios of the 1993 flood peak discharges to the Federal Emergency Management Agency 100-year flood peak discharges ranged from 1.25 to 3.29. The water-surface elevations ranged from 0.2 foot to 5.9 feet above the Federal Emergency Management Agency 500-year flood water-surface elevations. The very large flood peaks in these 3 small urban basins were the result of very intense rainfall in a short period of time, close to 100 percent runoff due to ground surfaces being essentially impervious, and the city streets acting as efficient conveyances to the main channels. The unit discharges compare in magnitude to other extraordinary Oklahoma urban floods.

  5. Sediment discharge during floods in eastern Nebraska

    USGS Publications Warehouse

    Mundorff, J.C.

    1962-01-01

    Runoff resulting from rapid melting of a deep snow cover over much of eastern Nebraska resulted in exceptionally high stream stages and in severe flooding on many streams in eastern Nebraska during the latter part of March and the early part of April in 1960. Suspended-sediment concentrations and discharges for most of the streams were somewhat lower than would be expected during similar water discharges that might result from torrential rains rather than snowmelt. During the period March 28-April 8, 1960, when the total water discharge of Platte River at Louisville and of Elkhorn River at Waterloo was about one-fourth of the total for the year, the sediment discharge was an estimated 46 to 50 percent of the estimated total for the year at each station. Both the percentage of sand and the concentration of sand in the suspended sediment were much higher for the Platte and Elkhorn Rivers than for streams in the Big Blue River and Nemaha River basins. For Platte River at Louisville and for Elkhorn River at Waterloo, measured sediment discharges ranged from about 87 to 94 percent of the computed total sediment discharge.

  6. Flood-discharge profiles of selected streams in Rockland County, New York

    USGS Publications Warehouse

    Lumia, Richard

    1984-01-01

    Flood-discharge profiles of 10 streams in Rockland County at six recurrence intervals ranging from 2 to 100 years are presented. Synthetic flood-frequency estimates were derived for nine rainfall-runoff sites from calibrated models; observed flood-frequency estimates were derived for three sites having long-term discharge records. A variance-weighting technique was applied to compare the synthetic flood-frequency estimates with the observed (gaged) estimates and estimates computed at each site from regional regression equations. For ungaged locations on the 10 streams, flood-frequency relationships were derived from regional regression equations previously developed for New Jersey streams. Regional analysis indicated the most significant basin characteristics to be drainage area, streambed slope, storage, and amount of impervious cover. A method for refining (weighting) flood-frequency estimates at selected ungaged locations near rainfall-runoff and (or) long-term gaged sites is given. This report explains analytical methods and includes a list of basin characteristics at several locations along each stream and a table of peak discharges for the six recurrence intervals at 13 gaging stations. The profiles enable the determination of flood discharge at all locations having a drainage area greater than 1 square mile on the 10 streams. (USGS)

  7. 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)

  8. Flood peaks and discharge summaries in the Delaware River basin

    USGS Publications Warehouse

    Vickers, A.A.; Farsett, Harry A.; Green, J. Wayne

    1981-01-01

    This report contains streamflow data from 299 continuous and partial-record gaging stations in the Delaware River basin. The location, drainage area, period of record, type of gage, and average flow (discharge) is given for each continuous station. Also included, are annual flood peak discharges and discharges above a selected base, annual and monthly mean discharges, and annual and monthly runoff. (USGS)

  9. Computation of backwater and discharge at width constrictions of heavily vegetated flood plains

    USGS Publications Warehouse

    Schneider, V.R.; Board, J.W.; Colson, B.E.; Lee, F.N.; Druffel, Leroy

    1977-01-01

    The U.S. Geological Survey, cooperated with the Federal Highway Administration and the State Highway Departments of Mississippi, Alabama, and Louisiana, to develop a proposed method for computing backwater and discharge at width constrictions of heavily vegetated flood plains. Data were collected at 20 single opening sites for 31 floods. Flood-plain width varied from 4 to 14 times the bridge opening width. The recurrence intervals of peak discharge ranged from a 2-year flood to greater than a 100-year flood, with a median interval of 6 years. Measured backwater ranged from 0.39 to 3.16 feet. Backwater computed by the present standard Geological Survey method averaged 29 percent less than the measured, and that computed by the currently used Federal Highway Administration method averaged 47 percent less than the measured. Discharge computed by the Survey method averaged 21 percent more then the measured. Analysis of data showed that the flood-plain widths and the Manning 's roughness coefficient are larger than those used to develop the standard methods. A method to more accurately compute backwater and discharge was developed. The difference between the contracted and natural water-surface profiles computed using standard step-backwater procedures is defined as backwater. The energy loss terms in the step-backwater procedure are computed as the product of the geometric mean of the energy slopes and the flow distance in the reach was derived from potential flow theory. The mean error was 1 percent when using the proposed method for computing backwater and 3 percent for computing discharge. (Woodard-USGS)

  10. Relation between largest known flood discharge and elevation in Montana

    USGS Publications Warehouse

    Parrett, Charles; Holnbeck, Stephen R.

    1994-01-01

    Previous studies relating unit discharge to elevation indicated that large floods in the Rocky Mountains may be limited by elevation. However, high-elevation data are sparse in Montana and the indications may not be entirely correct. Based on data at 19 sites in Montana, a strong log-linear relation exists between large-flood discharge and drainage area. The use of unit discharge (peak discharge divided by drainage area) to compare flood magnitude from site to site may thus be biased and tend to overstate flood magnitude for small basins. Removal of the bias by use of a revised unit discharge (peak discharge divided by drainage area raised to the 0.16 power) results in no apparent relation between revised unit discharge and elevation in two areas of Montana. However, because of a paucity of data, the magnitude of revised unit discharge at elevations greater than 1,650 m is largely unknown. Additional data and research are needed to resolve questions about mountain flood hydrology.

  11. Dissemination of satellite-based river discharge and flood data

    NASA Astrophysics Data System (ADS)

    Kettner, A. J.; Brakenridge, G. R.; van Praag, E.; de Groeve, T.; Slayback, D. A.; Cohen, S.

    2014-12-01

    In collaboration with NASA Goddard Spaceflight Center and the European Commission Joint Research Centre, the Dartmouth Flood Observatory (DFO) daily measures and distributes: 1) river discharges, and 2) near real-time flood extents with a global coverage. Satellite-based passive microwave sensors and hydrological modeling are utilized to establish 'remote-sensing based discharge stations', and observed time series cover 1998 to the present. The advantages over in-situ gauged discharges are: a) easy access to remote or due to political reasons isolated locations, b) relatively low maintenance costs to maintain a continuous observational record, and c) the capability to obtain measurements during floods, hazardous conditions that often impair or destroy in-situ stations. Two MODIS instruments aboard the NASA Terra and Aqua satellites provide global flood extent coverage at a spatial resolution of 250m. Cloud cover hampers flood extent detection; therefore we ingest 6 images (the Terra and Aqua images of each day, for three days), in combination with a cloud shadow filter, to provide daily global flood extent updates. The Flood Observatory has always made it a high priority to visualize and share its data and products through its website. Recent collaborative efforts with e.g. GeoSUR have enhanced accessibility of DFO data. A web map service has been implemented to automatically disseminate geo-referenced flood extent products into client-side GIS software. For example, for Latin America and the Caribbean region, the GeoSUR portal now displays current flood extent maps, which can be integrated and visualized with other relevant geographical data. Furthermore, the flood state of satellite-observed river discharge sites are displayed through the portal as well. Additional efforts include implementing Open Geospatial Consortium (OGC) standards to incorporate Water Markup Language (WaterML) data exchange mechanisms to further facilitate the distribution of the satellite

  12. Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Atkins, John T.

    2010-01-01

    Flood-frequency discharges were determined for 290 streamgage stations having a minimum of 9 years of record in West Virginia and surrounding states through the 2006 or 2007 water year. No trend was determined in the annual peaks used to calculate the flood-frequency discharges. Multiple and simple least-squares regression equations for the 100-year (1-percent annual-occurrence probability) flood discharge with independent variables that describe the basin characteristics were developed for 290 streamgage stations in West Virginia and adjacent states. The regression residuals for the models were evaluated and used to define three regions of the State, designated as Eastern Panhandle, Central Mountains, and Western Plateaus. Exploratory data analysis procedures identified 44 streamgage stations that were excluded from the development of regression equations representative of rural, unregulated streams in West Virginia. Regional equations for the 1.1-, 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year flood discharges were determined by generalized least-squares regression using data from the remaining 246 streamgage stations. Drainage area was the only significant independent variable determined for all equations in all regions. Procedures developed to estimate flood-frequency discharges on ungaged streams were based on (1) regional equations and (2) drainage-area ratios between gaged and ungaged locations on the same stream. The procedures are applicable only to rural, unregulated streams within the boundaries of West Virginia that have drainage areas within the limits of the stations used to develop the regional equations (from 0.21 to 1,461 square miles in the Eastern Panhandle, from 0.10 to 1,619 square miles in the Central Mountains, and from 0.13 to 1,516 square miles in the Western Plateaus). The accuracy of the equations is quantified by measuring the average prediction error (from 21.7 to 56.3 percent) and equivalent years of record (from 2.0 to 70

  13. Estimating the magnitude of peak discharges for selected flood frequencies on small streams in South Carolina (1975)

    USGS Publications Warehouse

    Whetstone, B.H.

    1982-01-01

    A program to collect and analyze flood data from small streams in South Carolina was conducted from 1967-75, as a cooperative research project with the South Carolina Department of Highways and Public Transportation and the Federal Highway Administration. As a result of that program, a technique is presented for estimating the magnitude and frequency of floods on small streams in South Carolina with drainage areas ranging in size from 1 to 500 square miles. Peak-discharge data from 74 stream-gaging stations (25 small streams were synthesized, whereas 49 stations had long-term records) were used in multiple regression procedures to obtain equations for estimating magnitude of floods having recurrence intervals of 10, 25, 50, and 100 years on small natural streams. The significant independent variable was drainage area. Equations were developed for the three physiographic provinces of South Carolina (Coastal Plain, Piedmont, and Blue Ridge) and can be used for estimating floods on small streams. (USGS)

  14. 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.

  15. Estimating peak discharges, flood volumes, and hydrograph shapes of small ungaged urban streams in Ohio

    USGS Publications Warehouse

    Sherwood, J.M.

    1986-01-01

    Methods are presented for estimating peak discharges, flood volumes and hydrograph shapes of small (less than 5 sq mi) urban streams in Ohio. Examples of how to use the various regression equations and estimating techniques also are presented. Multiple-regression equations were developed for estimating peak discharges having recurrence intervals of 2, 5, 10, 25, 50, and 100 years. The significant independent variables affecting peak discharge are drainage area, main-channel slope, average basin-elevation index, and basin-development factor. Standard errors of regression and prediction for the peak discharge equations range from +/-37% to +/-41%. An equation also was developed to estimate the flood volume of a given peak discharge. Peak discharge, drainage area, main-channel slope, and basin-development factor were found to be the significant independent variables affecting flood volumes for given peak discharges. The standard error of regression for the volume equation is +/-52%. A technique is described for estimating the shape of a runoff hydrograph by applying a specific peak discharge and the estimated lagtime to a dimensionless hydrograph. An equation for estimating the lagtime of a basin was developed. Two variables--main-channel length divided by the square root of the main-channel slope and basin-development factor--have a significant effect on basin lagtime. The standard error of regression for the lagtime equation is +/-48%. The data base for the study was established by collecting rainfall-runoff data at 30 basins distributed throughout several metropolitan areas of Ohio. Five to eight years of data were collected at a 5-min record interval. The USGS rainfall-runoff model A634 was calibrated for each site. The calibrated models were used in conjunction with long-term rainfall records to generate a long-term streamflow record for each site. Each annual peak-discharge record was fitted to a Log-Pearson Type III frequency curve. Multiple

  16. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    The estimation of streamflow rates based on post-flood surveys is of paramount importance for the investigation of extreme hydrological events. Major uncertainties usually arise from the absence of information on the flow velocities and from the limited spatio-temporal resolution of such surveys. Nowadays, after each flood occuring in populated areas home movies taken from bridges, river banks or even drones are shared by witnesses through Internet platforms like YouTube. Provided that some topography data and additional information are collected, image-based velocimetry techniques can be applied to some of these movie materials, in order to estimate flood discharges. As a contribution to recent post-flood surveys conducted in France, we developed and applied a method for estimating velocities and discharges based on the Large Scale Particle Image Velocimetry (LSPIV) technique. Since the seminal work of Fujita et al. (1998), LSPIV applications to river flows were reported by a number of authors and LSPIV can now be considered a mature technique. However, its application to non-professional movies taken by flood witnesses remains challenging and required some practical developments. The different steps to apply LSPIV analysis to a flood home movie are as follows: (i) select a video of interest; (ii) contact the author for agreement and extra information; (iii) conduct a field topography campaign to georeference Ground Control Points (GCPs), water level and cross-sectional profiles; (iv) preprocess the video before LSPIV analysis: correct lens distortion, align the images, etc.; (v) orthorectify the images to correct perspective effects and know the physical size of pixels; (vi) proceed with the LSPIV analysis to compute the surface velocity field; and (vii) compute discharge according to a user-defined velocity coefficient. Two case studies in French mountainous rivers during extreme floods are presented. The movies were collected on YouTube and field topography

  18. Techniques for estimating flood-peak discharges of rural, unregulated streams in Ohio

    USGS Publications Warehouse

    Koltun, G.F.; Roberts, J.W.

    1990-01-01

    Multiple-regression equations are presented for estimating flood-peak discharges having recurrence intervals of 2, 5, 10, 25, 50, and 100 years at ungaged sites on rural, unregulated streams in Ohio. The average standard errors of prediction for the equations range from 33.4% to 41.4%. Peak discharge estimates determined by log-Pearson Type III analysis using data collected through the 1987 water year are reported for 275 streamflow-gaging stations. Ordinary least-squares multiple-regression techniques were used to divide the State into three regions and to identify a set of basin characteristics that help explain station-to- station variation in the log-Pearson estimates. Contributing drainage area, main-channel slope, and storage area were identified as suitable explanatory variables. Generalized least-square procedures, which include historical flow data and account for differences in the variance of flows at different gaging stations, spatial correlation among gaging station records, and variable lengths of station record were used to estimate the regression parameters. Weighted peak-discharge estimates computed as a function of the log-Pearson Type III and regression estimates are reported for each station. A method is provided to adjust regression estimates for ungaged sites by use of weighted and regression estimates for a gaged site located on the same stream. Limitations and shortcomings cited in an earlier report on the magnitude and frequency of floods in Ohio are addressed in this study. Geographic bias is no longer evident for the Maumee River basin of northwestern Ohio. No bias is found to be associated with the forested-area characteristic for the range used in the regression analysis (0.0 to 99.0%), nor is this characteristic significant in explaining peak discharges. Surface-mined area likewise is not significant in explaining peak discharges, and the regression equations are not biased when applied to basins having approximately 30% or less

  19. [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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    The estimation of streamflow rates based on post-flood surveys is of paramount importance for the investigation of extreme hydrological events. Major uncertainties usually arise from the absence of information on the flow velocities and from the limited spatio-temporal resolution of such surveys. Nowadays, after each flood occuring in populated areas home movies taken from bridges, river banks or even drones are shared by witnesses through Internet platforms like YouTube. Provided that some topography data and additional information are collected, image-based velocimetry techniques can be applied to some of these movie materials, in order to estimate flood discharges. As a contribution to recent post-flood surveys conducted in France, we developed and applied a method for estimating velocities and discharges based on the Large Scale Particle Image Velocimetry (LSPIV) technique. Since the seminal work of Fujita et al. (1998), LSPIV applications to river flows were reported by a number of authors and LSPIV can now be considered a mature technique. However, its application to non-professional movies taken by flood witnesses remains challenging and required some practical developments. The different steps to apply LSPIV analysis to a flood home movie are as follows: (i) select a video of interest; (ii) contact the author for agreement and extra information; (iii) conduct a field topography campaign to georeference Ground Control Points (GCPs), water level and cross-sectional profiles; (iv) preprocess the video before LSPIV analysis: correct lens distortion, align the images, etc.; (v) orthorectify the images to correct perspective effects and know the physical size of pixels; (vi) proceed with the LSPIV analysis to compute the surface velocity field; and (vii) compute discharge according to a user-defined velocity coefficient. Two case studies in French mountainous rivers during extreme floods are presented. The movies were collected on YouTube and field topography

  1. Elevations and discharges produced by a simulated flood wave on the lower Sabine River, Louisiana and Texas, caused by a theoretical dam failure

    USGS Publications Warehouse

    Neely, Braxtel L.; Stiltner, Gloria J.

    1979-01-01

    The Toledo Bend Reservoir is located on the lower Sabine River between Louisiana and Texas. Two mathematical models were coupled to calculate the flood wave that would result from the theoretical failure of 25 percent of Toledo Bend Dam and route the wave downstream to Orange, Tex. Computations assumed failure (1) at the peak of the 100-year flood when discharge of the Sabine River is 102,000 cubic feet per second and (2) when the average discharge is 10,000 cubic feet per second. Two techniques were used in the dam-break model. The method of characteristics was used to propagate the shock wave following dam failure. The linear implicit finite-difference solution was used to route the flood wave following shock wave dissipation. The magnitude of the flow was determined for Burkeville, Bon Wier, Ruliff, and Orange, Tex., along the lower Sabine River. For these sites, respectively, the following peak elevations were calculated: 119, 82, 31, and 13 feet for the 100-year flood and 110, 75, 27, and 9 feet for the average discharge. (Woodard-USGS)

  2. 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

  3. Flood discharges and hydraulics near the mouths of Wolf Creek, Craig Branch, Manns Creek, Dunloup Creek, and Mill Creek in the New River Gorge National River, West Virginia

    USGS Publications Warehouse

    Wiley, J.B.

    1994-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service, studied the frequency and magnitude of flooding near the mouths of five tributaries to the New River in the New River Gorge National River. The 100-year peak discharge at each tributary was determined from regional frequency equations. The 100-year discharge at Wolf Creek, Craig Branch, Manns Creek, Dunloup Creek, and Mill Creek was 3,400 cubic feet per second, 640 cubic feet per second, 8,200 cubic feet per second, 7,100 cubic feet per second, and 9,400 cubic feet per second, respectively. Flood elevations for each tributary were determined by application of a steady-state, one-dimensional flow model. Manning's roughness coefficients for the stream channels ranged from 0.040 to 0.100. Bridges that would be unable to contain the 100-year flood within the bridge opening included: the State Highway 82 bridge on Wolf Creek, the second Fayette County Highway 25 bridge upstream from the confluence with New River on Dunloup Creek, and an abandoned log bridge on Mill Creek.

  4. A summary of peak stages and discharges in New York for the flood of June 1972

    USGS Publications Warehouse

    Darmer, Kenneth I.

    1972-01-01

    Intense rainfall associated with Tropical Storm Agnes in late June 1972 resulted in the greatest flood disaster in the history of New York State. Flooding began in Westchester County on June 19 and was followed by widespread flooding in the Southern Tier and the Fingers Lakes region on June 23. The purpose of this report is to make available preliminary peak stage and discharge data for New York streams. Detailed analyses of precipitation, stage and discharge hydrographs, flood frequency, and flood profiles will be presented in subsequent reports. Inundation maps for 39 quadrangles were prepared.

  5. Peak Discharge, Flood Profile, Flood Inundation, and Debris Movement Accompanying the Failure of the Upper Reservoir at the Taum Sauk Pump Storage Facility near Lesterville, Missouri

    USGS Publications Warehouse

    Rydlund, Paul H.

    2006-01-01

    The Taum Sauk pump-storage hydroelectric power plant located in Reynolds County, Missouri, uses turbines that operate as pumps and hydraulic head generated by discharging water from an upper to a lower reservoir to produce electricity. A 55-acre upper reservoir with a 1.5- billion gallon capacity was built on top of Proffit Mountain, approximately 760 feet above the floodplain of the East Fork Black River. At approximately 5:16 am on December 14, 2005, a 680-foot wide section of the upper reservoir embankment failed suddenly, sending water rushing down the western side of Proffit Mountain and emptying into the floodplain of East Fork Black River. Flood waters from the upper reservoir flowed downstream through Johnson's Shut-Ins State Park and into the lower reservoir of the East Fork Black River. Floods such as this present unique challenges and opportunities to analyze and document peak-flow characteristics, flood profiles, inundation extents, and debris movement. On December 16, 2005, Light Detection and Ranging (LiDAR) data were collected and used to support hydraulic analyses, forensic failure analyses, damage extent, and mitigation of future disasters. To evaluate the impact of sedimentation in the lower reservoir, a bathymetric survey conducted on December 22 and 23, 2005, was compared to a previous bathymetric survey conducted in April, 2005. Survey results indicated the maximum reservoir capacity difference of 147 acre-feet existed at a pool elevation of 730 feet. Peak discharge estimates of 289,000 cubic feet per second along Proffit Mountain and 95,000 cubic feet per second along the East Fork Black River were determined through indirect measurement techniques. The magnitude of the embankment failure flood along the East Fork Black River was approximately 4 times greater than the 100-year flood frequency estimate of 21,900 cubic feet per second, and approximately 3 times greater than the 500-year flood frequency estimate of 30,500 cubic feet per second

  6. Practical Experience of Discharge Measurement in Flood Conditions with ADP

    NASA Astrophysics Data System (ADS)

    Vidmar, A.; Brilly, M.; Rusjan, S.

    2009-04-01

    Accurate discharge estimation is important for an efficient river basin management and especially for flood forecasting. The traditional way of estimating the discharge in hydrological practice is to measure the water stage and to convert the recorded water stage values into discharge by using the single-valued rating curve .Relationship between the stage and discharge values of the rating curve for the extreme events are usually extrapolated by using different mathematical methods and are not directly measured. Our practice shows that by using the Accoustic Doppler Profiler (ADP) instrument we can record the actual relation between the water stage and the flow velocity at the occurrence of flood waves very successfully. Measurement in flood conditions it is not easy task, because of high water surface velocity and large amounts of sediments in the water and floating objects on the surface like branches, bushes, trees, piles and others which can also easily damage ADP instrument. We made several measurements in such extreme events on the Sava River down to the nuclear power plant Kr\\vsko where we have install fixed cable way. During the several measurement with traditional "moving-boat" measurement technique a mowing bed phenomenon was clearly seen. Measuring flow accurately using ADP that uses the "moving-boat" technique, the system needs a reference against which to relate water velocities to. This reference is river bed and must not move. During flood events we detected difficulty finding a static bed surface to which to relate water velocities. This is caused by motion of the surface layer of bed material or also sediments suspended in the water near bed very densely. So these traditional »moving-boat« measurement techniques that we normally use completely fail. Using stationary measurement method to making individual velocity profile measurements, using an Acoustic Doppler Profiler (ADP), at certain time at fixed locations across the width of a stream gave

  7. Techniques for estimating flood discharges for unregulated streams in New Mexico

    USGS Publications Warehouse

    Thomas, Richard P.; Gold, Robert L.

    1982-01-01

    Equations for estimating flood magnitudes at selected recurrence intervals from 2 to 500 years were developed using multiple-regression analyses. These equations relate flood magnitudes to basin characteristics, contributing drainage area and site altitude, and only are applicable to unregulated streams in New Mexico that are relatively unaffected by urban runoff. Estimates of floods at or near gaged sites may be computed with an equation that adjusts discharges developed with the regression equations using station-specific discharges. (USGS)

  8. Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA

    USGS Publications Warehouse

    Fenton, C.R.; Webb, R.H.; Cerling, T.E.

    2006-01-01

    The failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of the Hyaloclastite Dam released a maximum 11 ?? 109 m3 of water in 31 h. Peak discharges, estimated from uncertainty in channel geometry, dam height, and hydraulic characteristics, ranged from 2.3 to 5.3 ?? 105 m3 s-1 for the Hyaloclastite outburst flood. This discharge is an order of magnitude greater than the largest known discharge on the Colorado River (1.4 ?? 104 m3 s-1) and the largest peak discharge resulting from failure of a constructed dam in the USA (6.5 ?? 104 m3 s-1). Moreover, the Hyaloclastite outburst flood is the oldest documented Quaternary flood and one of the largest to have occurred in the continental USA. The peak discharge for this flood ranks in the top 30 floods (>105 m3 s-1) known worldwide and in the top ten largest floods in North America. ?? 2005 University of Washington. All rights reserved.

  9. Documented and potential extreme peak discharges and relation between potential extreme peak discharges and probable maximum flood peak discharges in Texas

    USGS Publications Warehouse

    Asquith, W.H.; Slade, R.M., Jr.

    1995-01-01

    The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, conducted a study of extreme flood potential for Texas. Potential extreme peak discharges, derived from the relation between documented extreme peak discharges and their contributing drainage areas, can provide valuable information concerning the maximum expected peak discharge that could occur at a stream site. Documented extreme peak discharges and associated data were aggregated for 832 sites with and without streamflow-gaging stations in natural basins in Texas. A potential extreme peak discharge curve was developed for each of 11 hydrologic regions in Texas and for the State as a whole, based on documented extreme peak discharges and associated contributing drainage areas. The curve envelops, for a large range of drainage areas, the largest documented extreme peak discharges. Potential extreme peak discharges estimated from the curves were compared to probable maximum flood peak discharges estimated from various simulation models.

  10. 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.

  11. Peak discharge estimates of glacial-lake outburst floods and ``normal'' climatic floods in the Mount Everest region, Nepal

    NASA Astrophysics Data System (ADS)

    Cenderelli, Daniel A.; Wohl, Ellen E.

    2001-09-01

    Glacial-lake outburst floods (GLOFs) in the Mount Everest region of Nepal on 3 September 1977 and 4 August 1985 dramatically modified channels and valleys in the region by eroding, transporting, and depositing large quantities of sediment for tens of kilometers along their flood routes. Prior to this research, the GLOF discharges had not been determined and the hydrology of "normal" climatic floods (SHFFs: seasonal high flow floods) was not known. A one-dimensional step-backwater flow model was utilized, in conjunction with paleostage indicators, to estimate the peak discharges of the GLOFs and SHFFs and to reconstruct the hydrology and hydraulic conditions of the GLOFs at 10 reaches and SHFFs at 18 reaches. The most reliable GLOF and SHFF peak discharge estimates were upstream from constrictions where there was critical-depth control. The peak discharge of the 1977 GLOF at 8.6 km from the breached moraine was approximately 1900 m 3/s. At 7.1 km downstream from the breached moraine, the 1985 GLOF discharge was estimated at 2350 m 3/s. At 27 km downstream from the breached moraine, the 1985 GLOF attenuated to an estimated discharge of 1375 m 3/s. The peak discharges of SHFFs ranged from 7 to 205 m 3/s and were positively correlated with increasing drainage area. The GLOF discharges were 7 to 60 times greater than the SHFF discharges with the greatest ratios occurring near the breached moraines. The downstream decline in the ratio between the GLOF discharge and SHFF discharge is the result of the downstream attenuation of the GLOF and the increased discharge of the SHFF because of increased contributing drainage area and the increased effects of monsoonal precipitation at lower elevations.

  12. Flood discharge measurement of a mountain river - Nanshih River in Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Y.-C.

    2013-05-01

    This study proposes a more efficient method of flood discharge measurement in mountain rivers that accounts for personal safety, accuracy, and reliability. Because it is based on the relationships between mean and maximum velocities and between cross-sectional area and gauge height, the proposed method utilizes a flood discharge measurement system composed of an acoustic Doppler profiler and crane system to measure velocity distributions, cross-sectional area, and water depths. The flood discharge measurement system can be used to accurately and quickly measure flood data that is difficult to be collected by the conventional instruments. The measured data is then used to calibrate the parameters of the proposed method for estimating mean velocity and cross-sectional area. Then these observed discharge and gauge height can be used to establish the water stage-discharge rating curve. Therefor continuous and real-time estimations of flood discharge of a mountain river can become possible. The measurement method and system is applied to the Nanshih River at the Lansheng Bridge. Once the method is established, flood discharge of the Nanshih River could be efficiently estimated using maximum velocity and the water stage. Results of measured and estimated discharges of the Nanshih River at the Lansheng Bridge differed only slightly from each other, demonstrating the efficiency and accuracy of the proposed method.

  13. Effects of reservoirs on flood discharges in the Kansas and the Missouri River basins, 1993

    USGS Publications Warehouse

    Perry, Charles A.

    1994-01-01

    The floods of 1993 were of historic magnitude as water in the Missouri and the Mississippi Rivers reached levels that exceeded many of the previous observed maximums. Although large parts of the flood plains of both rivers upstream from St. Louis, Missouri, were inundated, water levels would have been even higher had it not been for the large volume of runoff retained in flood-control reservoirs. Most of the total flood-control storage available upstream from St. Louis is located along the main stem and tributaries of the Missouri River; the largest concentration of reservoirs is located within the Kansas River Basin. The Kansas River Basin accounts for about l0 percent (60,000 square miles) of the drainage area of the Missouri River Basin, and reservoirs control streamflow from 85 percent (50,840 square miles) of the drainage area of the Kansas River Basin. Analyses of flood discharges in the Kansas River indicate that reservoirs reduced flooding along the Kansas and the lower Missouri Rivers. Results of analyses of the 1993 flooding, which include total basin rainfall, peak discharge, and total flood volume on the Kansas River, are compared with analyses of the 1951 flood, which had a similar total volume but a substantially larger peak discharge.

  14. Canyon formation constraints on the discharge of catastrophic outburst floods of Earth and Mars

    NASA Astrophysics Data System (ADS)

    Lapotre, Mathieu G. A.; Lamb, Michael P.; Williams, Rebecca M. E.

    2016-07-01

    Catastrophic outburst floods carved amphitheater-headed canyons on Earth and Mars, and the steep headwalls of these canyons suggest that some formed by upstream headwall propagation through waterfall erosion processes. Because topography evolves in concert with water flow during canyon erosion, we suggest that bedrock canyon morphology preserves hydraulic information about canyon-forming floods. In particular, we propose that for a canyon to form with a roughly uniform width by upstream headwall retreat, erosion must occur around the canyon head, but not along the sidewalls, such that canyon width is related to flood discharge. We develop a new theory for bedrock canyon formation by megafloods based on flow convergence of large outburst floods toward a horseshoe-shaped waterfall. The model is developed for waterfall erosion by rock toppling, a candidate erosion mechanism in well fractured rock, like columnar basalt. We apply the model to 14 terrestrial (Channeled Scablands, Washington; Snake River Plain, Idaho; and Ásbyrgi canyon, Iceland) and nine Martian (near Ares Vallis and Echus Chasma) bedrock canyons and show that predicted flood discharges are nearly 3 orders of magnitude less than previously estimated, and predicted flood durations are longer than previously estimated, from less than a day to a few months. Results also show a positive correlation between flood discharge per unit width and canyon width, which supports our hypothesis that canyon width is set in part by flood discharge. Despite lower discharges than previously estimated, the flood volumes remain large enough for individual outburst floods to have perturbed the global hydrology of Mars.

  15. Flood Frequency Estimates and Documented and Potential Extreme Peak Discharges in Oklahoma

    USGS Publications Warehouse

    Tortorelli, Robert L.; McCabe, Lan P.

    2001-01-01

    Knowledge of the magnitude and frequency of floods is required for the safe and economical design of highway bridges, culverts, dams, levees, and other structures on or near streams; and for flood plain management programs. Flood frequency estimates for gaged streamflow sites were updated, documented extreme peak discharges for gaged and miscellaneous measurement sites were tabulated, and potential extreme peak discharges for Oklahoma streamflow sites were estimated. Potential extreme peak discharges, derived from the relation between documented extreme peak discharges and contributing drainage areas, can provide valuable information concerning the maximum peak discharge that could be expected at a stream site. Potential extreme peak discharge is useful in conjunction with flood frequency analysis to give the best evaluation of flood risk at a site. Peak discharge and flood frequency for selected recurrence intervals from 2 to 500 years were estimated for 352 gaged streamflow sites. Data through 1999 water year were used from streamflow-gaging stations with at least 8 years of record within Oklahoma or about 25 kilometers into the bordering states of Arkansas, Kansas, Missouri, New Mexico, and Texas. These sites were in unregulated basins, and basins affected by regulation, urbanization, and irrigation. Documented extreme peak discharges and associated data were compiled for 514 sites in and near Oklahoma, 352 with streamflow-gaging stations and 162 at miscellaneous measurements sites or streamflow-gaging stations with short record, with a total of 671 measurements.The sites are fairly well distributed statewide, however many streams, large and small, have never been monitored. Potential extreme peak-discharge curves were developed for streamflow sites in hydrologic regions of the state based on documented extreme peak discharges and the contributing drainage areas. Two hydrologic regions, east and west, were defined using 98 degrees 15 minutes longitude as the

  16. Preliminary flood-frequency relations and summary of maximum discharges in New Mexico; a progress report

    USGS Publications Warehouse

    Scott, Arthur G.

    1971-01-01

    The magnitude and frequency of floods is defined regionally for streams in New Mexico. An analysis was made, using multiple- regression techniques, relating flood peaks of 2, 5, 10, 25, and 50-year recurrence intervals to selected physical and climatic basin characteristics. The state was divided into three flood regions, and the resulting equations and associated standard error of prediction are presented for each of these regions. In addition the maximum observed discharges at regular and crest-stage gaging stations, and all peak discharges by indirect measurements at miscellaneous sites are presented in tabular and graphical form. The equations developed in the study can be used to compute peak discharges of floods of given recurrence intervals for use in the design of drainage structures.

  17. On the value of satellite-based river discharge and river flood data

    NASA Astrophysics Data System (ADS)

    Kettner, A. J.; Brakenridge, R.; van Praag, E.; Borrero, S.; Slayback, D. A.; Young, C.; Cohen, S.; Prades, L.; de Groeve, T.

    2015-12-01

    Flooding is the most common natural hazard worldwide. According to the World Resources Institute, floods impact 21 million people every year and affect the global GDP by $96 billion. Providing accurate flood maps in near-real time (NRT) is critical to their utility to first responders. Also, in times of flooding, river gauging stations on location, if any, are of less use to monitor stage height as an approximation for water surface area, as often the stations themselves get washed out or peak water levels reach much beyond their design measuring capacity. In a joint effort with NASA Goddard Space Flight Center, the European Commission Joint Research Centre and the University of Alabama, the Dartmouth Flood Observatory (DFO) measures NRT: 1) river discharges, and 2) water inundation extents, both with a global coverage on a daily basis. Satellite-based passive microwave sensors and hydrological modeling are utilized to establish 'remote-sensing based discharge stations'. Once calibrated, daily discharge time series span from 1998 to the present. Also, the two MODIS instruments aboard the NASA Terra and Aqua satellites provide daily floodplain inundation extent with global coverage at a spatial resolution of 250m. DFO's mission is to provide easy access to NRT river and flood data products. Apart from the DFO web portal, several water extent products can be ingested by utilizing a Web Map Service (WMS), such as is established with for Latin America and the Caribbean (LAC) region through the GeoSUR program portal. This effort includes implementing over 100 satellite discharge stations showing in NRT if a river is flooding, normal, or in low flow. New collaborative efforts have resulted in flood hazard maps which display flood extent as well as exceedance probabilities. The record length of our sensors allows mapping the 1.5 year, 5 year and 25 year flood extent. These can provide key information to water management and disaster response entities.

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

    USGS Publications Warehouse

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

    2008-01-01

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

  19. Estimation of Flood Discharges at Selected Recurrence Intervals for Streams in New Hampshire

    USGS Publications Warehouse

    Olson, Scott A.

    2009-01-01

    This report provides estimates of flood discharges at selected recurrence intervals for streamgages in and adjacent to New Hampshire and equations for estimating flood discharges at recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, and 500-years for ungaged, unregulated, rural streams in New Hampshire. The equations were developed using generalized least-squares regression. Flood-frequency and drainage-basin characteristics from 117 streamgages were used in developing the equations. The drainage-basin characteristics used as explanatory variables in the regression equations include drainage area, mean April precipitation, percentage of wetland area, and main channel slope. The average standard error of prediction for estimating the 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence interval flood discharges with these equations are 30.0, 30.8, 32.0, 34.2, 36.0, 38.1, and 43.4 percent, respectively. Flood discharges at selected recurrence intervals for selected streamgages were computed following the guidelines in Bulletin 17B of the U.S. Interagency Advisory Committee on Water Data. To determine the flood-discharge exceedence probabilities at streamgages in New Hampshire, a new generalized skew coefficient map covering the State was developed. The standard error of the data on new map is 0.298. To improve estimates of flood discharges at selected recurrence intervals for 20 streamgages with short-term records (10 to 15 years), record extension using the two-station comparison technique was applied. The two-station comparison method uses data from a streamgage with long-term record to adjust the frequency characteristics at a streamgage with a short-term record. A technique for adjusting a flood-discharge frequency curve computed from a streamgage record with results from the regression equations is described in this report. Also, a technique is described for estimating flood discharge at a selected recurrence interval for an ungaged site upstream or downstream

  20. Effects of flood controls proposed for West Branch Brandywine Creek, Chester County, Pennsylvania

    USGS Publications Warehouse

    Sloto, R.A.

    1988-01-01

    Twenty-four-hour rainfall, distributed over time according to the U.S. Soil Conservation Service type II rainfall distribution, was used as input to calibrated rainfall-runoff models of three subbasins in the West Branch Brandywine Creek watershed. The effects of four proposed flood controls were evaluated by using these rainfalls to simulate discharge hydrographs with and without the flood controls and comparing the simulated peak discharges. In the Honey Brook subbasin, 2-, 10-, and 100-year flood-discharge hydrographs were generated for station West Branch Brandywine Creek at Coatesville. For the 2- and 10-year floods, proposed flood controls would reduce the peak discharge from 1 to 8 percent. The combination of all three flood controls proposed for the Coatesville subbasin would reduce the 100-year peak discharge 44 percent. In the Modena subbasin, 2-, 10-, and 100-year flood-discharge hydrographs were generated for station West Branch Brandywine Creek at Modena. A flood control proposed for Sucker Run, a tributary, would reduce the peak discharge of Sucker Run at State Route 82 by 22, 25, and 27 percent and the peak discharge of West Branch Brandywine Creek at Modena by 10, 6, and less than 1 percent for the 2-, 10-, and 100-year floods, respectively. For the 2- and 10- year floods, flood control proposed for the Coatesville subbasin would have little effect on the peak discharge of West Branch Brandywine Creek at Modena. For the 100-year flood, the combination of all three flood controls proposed for the Coatesville subbasin would reduce the peak discharge at Modena 25 percent. When flood control in the Modena subbasin was combined with flood control in the Coatesville subbasin, the 10-percent reduction in the 2-year flood peak of West Branch Brandywine Creek at Modena was due almost entirely to flood control in the Modena subbasin. For the 10-year flood, flood control in the Modena subbasin would reduce the peak discharge 6 percent, and any single flood

  1. Explaining the Physical Relation of Estuaries Shape and Bankfull Flood Discharge

    NASA Astrophysics Data System (ADS)

    Anak Gisen, Jacqueline Isabella; Savenije, Hubert H. G.

    2013-04-01

    Estimating flood discharge in the tidal region of estuaries is always difficult as most of the available gauging stations are installed much further upstream outside the tidal region. Inside the tidal region, it is hard to observe the river discharge accurately. In the morphology and hydrodynamic studies of estuaries, it is known that river discharge is one of the important parameters. Unfortunately, research on morphology and hydrodynamics in estuaries is done separately. Until today, little research has been done to identify the relationship between these two processes in alluvial estuaries, and to understand why certain relations in nature exist. This study aims to discover the physical explanation for the relation between the geometrical characteristics of estuaries and flood discharge. The relationship between the ideal estuary depth and fresh water discharge was analyzed in 13 estuaries around the world using a stepwise regression and the outcome was compared to Lacey's theory of hydraulic geometry. From the analysis, it shows that the ideal depth of the estuaries is a function to the bankfull flood discharge to the power of 1/3 to 1/2 which indicates an agreement with Lacey's formula. In order to verify the accuracy of the relation, more data on the morphology and hydrodynamics are required. Thus, existing and new measurement data from estuaries worldwide will be collected and compiled to strengthen the reliability of the finding. Keywords: estuaries, geometry, flood discharge, alluvial, tidal

  2. Estimating flood-peak discharge magnitudes and frequencies for rural streams in Illinois

    USGS Publications Warehouse

    Soong, David T.; Ishii, Audrey; Sharpe, Jennifer B.; Avery, Charles F.

    2004-01-01

    Flood-peak discharge magnitudes and frequencies at streamflow-gaging sites were developed with the annual maximum series (AMS) and the partial duration series (PDS) in this study. Regional equations for both flood series were developed for estimating flood-peak discharge magnitudes at specified recurrence intervals of rural Illinois streams. The regional equations are techniques for estimating flood quantiles at ungaged sites or for improving estimated flood quantiles at gaged sites with short records or unrepresentative data. Besides updating at-site floodfrequency estimates using flood data up to water year 1999, this study updated the generalized skew coefficients for Illinois to be used with the Log-Pearson III probability distribution for analyzing the AMS, developed a program for analyzing the partial duration series with the Generalized Pareto probability distribution, and applied the BASINSOFT program with digital datasets in soil, topography, land cover, and precipitation to develop a set of basin characteristics. The multiple regression analysis was used to develop the regional equations with subsets of the basin characteristics and the updated at-site flood frequencies. Seven hydrologic regions were delineated using physiographic and hydrologic characteristics of drainage basins of Illinois. The seven hydrologic regions were used for both the AMS and PDS analyses. Examples are presented to illustrate the use of the AMS regional equations to estimate flood quantiles at an ungaged site and to improve flood-quantile estimates at and near a gaged site. Flood-quantile estimates in four regulated channel reaches of Illinois also are approximated by linear interpolation. Documentation of the flood data preparation and evaluation, procedures for determining the flood quantiles, basin characteristics, generalized skew coefficients, hydrologic region delineations, and the multiple regression analyses used to determine the regional equations are presented in the

  3. Comparison of peak discharges among sites with and without valley fills for the July 8-9, 2001 flood in the headwaters of Clear Fork, Coal River basin, mountaintop coal-mining region, southern West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Brogan, Freddie D.

    2003-01-01

    The effects of mountaintop-removal mining practices on the peak discharges of streams were investigated in six small drainage basins within a 7-square-mile area in southern West Virginia. Two of the small basins had reclaimed valley fills, one basin had reclaimed and unreclaimed valley fills, and three basins did not have valley fills. Indirect measurements of peak discharge for the flood of July 8-9, 2001, were made at six sites on streams draining the small basins. The sites without valley fills had peak discharges with 10- to 25-year recurrence intervals, indicating that rainfall intensities and totals varied among the study basins. The flood-recurrence intervals for the three basins with valley fills were determined as though the peak discharges were those from rural streams without the influence of valley fills, and ranged from less than 2 years to more than 100 years.

  4. Techniques for estimating flood-peak discharges from urban basins in Missouri

    USGS Publications Warehouse

    Becker, L.D.

    1986-01-01

    Techniques are defined for estimating the magnitude and frequency of future flood peak discharges of rainfall-induced runoff from small urban basins in Missouri. These techniques were developed from an initial analysis of flood records of 96 gaged sites in Missouri and adjacent states. Final regression equations are based on a balanced, representative sampling of 37 gaged sites in Missouri. This sample included 9 statewide urban study sites, 18 urban sites in St. Louis County, and 10 predominantly rural sites statewide. Short-term records were extended on the basis of long-term climatic records and use of a rainfall-runoff model. Linear least-squares regression analyses were used with log-transformed variables to relate flood magnitudes of selected recurrence intervals (dependent variables) to selected drainage basin indexes (independent variables). For gaged urban study sites within the State, the flood peak estimates are from the frequency curves defined from the synthesized long-term discharge records. Flood frequency estimates are made for ungaged sites by using regression equations that require determination of the drainage basin size and either the percentage of impervious area or a basin development factor. Alternative sets of equations are given for the 2-, 5-, 10-, 25-, 50-, and 100-yr recurrence interval floods. The average standard errors of estimate range from about 33% for the 2-yr flood to 26% for the 100-yr flood. The techniques for estimation are applicable to flood flows that are not significantly affected by storage caused by manmade activities. Flood peak discharge estimating equations are considered applicable for sites on basins draining approximately 0.25 to 40 sq mi. (Author 's abstract)

  5. Measuring the Discharge of River Flood Using Witnesses Movies Found on the Internet

    NASA Astrophysics Data System (ADS)

    Hauet, A.; Le Coz, J.; Le Boursicaud, R.; Pénard, L.

    2014-12-01

    The knowledge of the discharge of river during extreme flood is of prime importance for the scientific and the research community. Unfortunately, measuring discharge using conventional methods is impossible because the high velocities and the floating debris endanger the operators and the equipment. The typical time-scale for gauging does not match up to the time scale of the dynamic of extreme flood. Finally, floods are mesoscale events that affect generally several watersheds at the same time, and gauging teams do not have the capabilities for covering the whole region of interest. Recently, non intrusive method for measuring discharge have been developed and tested in flood conditions. Doppler surface velocity radar and Large Scale Particle Image Velocimetry (LSPIV) showed their efficiency for measuring discharge during extreme events, but those methods need to be deployed by operators and the problems of time-scale and space-scale covering aforementioned are not solved. In this study, authors present how flood discharge measurement can benefits from the huge development, the last 10 years, of internet and of the on-line sharing of files. Floods are impressive phenomena, and hundreds of witnesses movies can be found on the internet after every important event. The different steps in order to apply LSPIV analysis to witness movie are detailed: (i) selection of the video of interest; (ii) contact with the author of the video; (iii) preparing the video for the LSPIV analysis : stabilization of the images, field campaigns; (iv) LSPIV analysis, providing surface velocity field; and (v)discharge computation. A case study on the major flash flood of 18 June 2013 of the Gave River at Cauterets, French Pyrennees, is presented. Results show that witnesses movies can bring useful information and allow estimating discharges values. Capabilities and limitations of LSPIV applied to witnesses movies are detailed. Finally, the paper presents an approach conducted within the

  6. Floods of May 1981 in west-central Montana

    USGS Publications Warehouse

    Parrett, Charles; Omang, R.J.; Hull, J.A.; Fassler, John W.

    1982-01-01

    Extensive flooding occurred in west-central Montana during May 22-23, 1981, as a result of a series of rainstorms. Flooding was particularly severe in the communities of East Helena, Belt, and Deer Lodge. Although no lives were lost, total flood damages were estimated by the Montana Disaster Emergency Services Division to be in excess of $30 million. Peak discharges were determined at 75 sites in the flooded area. At 25 sites the May 1981 peak discharge exceeded the computed 100-year frequency flood, and at 29 sites, where previous flow records are available, the May 1981 peak discharge exceeded the previous peak of record. (USGS)

  7. 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…

  8. 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.

  9. Flood Assessment at the Area 5 Radioactive Waste Management Site and the Proposed Hazardous Waste Storage Unit, DOE/Nevada Test Site, Nye County, Nevada

    SciTech Connect

    Schmeltzer, J. S.; Millier, J. J.; Gustafson, D. L.

    1993-01-01

    A flood assessment at the Radioactive Waste Management Site (RWMS) and the proposed Hazardous Waste Storage Unit (HWSU) in Area 5 of the Nevada Test Site (NTS) was performed to determine the 100-year flood hazard at these facilities. The study was conducted to determine whether the RWMS and HWSU are located within a 100-year flood hazard as defined by the Federal Emergency Management Agency, and to provide discharges for the design of flood protection.

  10. 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.

  11. Delineation of flooding within the upper Mississippi River Basin-flood of June 19-July 31, 1993, in Davenport, Iowa and vicinity

    USGS Publications Warehouse

    Schaap, Bryan D.

    1996-01-01

    The hydrologic investigations atlas shows areas in and near Davenport, Iowa, that were flooded by the Mississippi River in 1993. This atlas also depicts the Federal Emergency Management Agency 100-year flood boundary. The drainage basin upstream from Mississippi River Lock and Dam 15 at Davenport received between 100 and 250 percent of normal rainfall from January through July, 1993. The profile of the maximum water-surface elevations of the 1993 flood in the Davenport area is less than the Federal Emergency Management Agency 100-year flood profile. The Mississippi River Lock and Dam 15 tailwater elevation was above the flood elevation from June 19 to July 31, 1993, but did not exceed the 100-year flood elevation. For most of the time during October 1992 through September 1993, the daily mean discharge of the Mississippi River at Clinton, Iowa, greatly exceeded the monthly mean discharges from October 1874 through September 1993, but was less than the 100-year flood discharge. The daily mean discharge at Keokuk, Iowa, exceeded the 100-year flood discharge for nearly the entire month of July 1993.

  12. River discharge and flood inundation over the Amazon based on IPCC AR5 scenarios

    NASA Astrophysics Data System (ADS)

    Paiva, Rodrigo; Sorribas, Mino; Jones, Charles; Carvalho, Leila; Melack, John; Bravo, Juan Martin; Beighley, Edward

    2015-04-01

    Climate change and related effects over the hydrologic regime of the Amazon River basin could have major impacts over human and ecological communities, including issues with transportation, flood vulnerability, fisheries and hydropower generation. We examined future changes in discharge and floodplain inundation within the Amazon River basin. We used the hydrological model MGB-IPH (Modelo de Grandes Bacias - Instituto de Pesquisas Hidráulicas) coupled with a 1D river hydrodynamic model simulating water storage over the floodplains. The model was forced using satellite based precipitation from the TRMM 3B42 dataset, and it had a good performance when validated against discharge and stage measurements as well as remotely sensed data, including radar altimetry-based water levels, gravity anomaly-based terrestrial water storage and flood inundation extent. Future scenarios of precipitation and other relevant climatic variables for the 2070 to 2100 time period were taken from five coupled atmosphere-ocean general circulation models (AOGCMs) from IPCC's Fifth Assessment Report (AR5) Coupled Model Intercomparison Project Phase 5 (CMIP5). The climate models were chosen based on their ability to represent the main aspects of recent (1970 to 2000) Amazon climate. A quantile-quantile bias removal procedure was applied to climate model precipitation to mitigate unreliable predictions. The hydrologic model was then forced using past observed climate data altered by delta change factors based on the past and future climate models aiming to estimate projected discharge and floodplain inundation in climate change scenario at several control points in the basin. The climate projections present large uncertainty, especially the precipitation rate, and predictions using different climate models do not agree on the sign of changes on total Amazon flood extent or discharge along the main stem of the Amazon River. However, analyses of results at different regions indicate an increase

  13. Use of a Smartphone for Collecting Data on River Discharge and Communication of Flood Risk.

    NASA Astrophysics Data System (ADS)

    Pena-Haro, S.; Lüthi, B.; Philippe, T.

    2015-12-01

    Although many developed countries have well-established systems for river monitoring and flood early warning systems, the population affected in developing countries by flood events is unsettled. Even more, future climate development is likely to increase the intensity and frequency of extreme weather events and therefore bigger impacts on the population can be expected.There are different types of flood forecasting systems, some are based on hydrologic models fed with rainfall predictions and observed river levels. Flood hazard maps are also used to increase preparedness in case of an extreme event, however these maps are static since they do not incorporate daily changing conditions on river stages. However, and especially in developing countries, data on river stages are scarce. Some of the reasons are that traditional fixed monitoring systems do not scale in terms of costs, repair is difficult as well as operation and maintenance, in addition vandalism poses additional challenges. Therefore there is a need of cheaper and easy-to-use systems for collecting information on river stage and discharge. We have developed a mobile device application for determining the water stage and discharge of open-channels (e.g. rivers, artificial channels, irrigation furrows). Via image processing the water level and surface velocity are measured, combining this information with priori knowledge on the channel geometry the discharge is estimated. River stage and discharge measurement via smart phones provides a non-intrusive, accurate and cost-effective monitoring method. No permanent installations, which can be flooded away, are needed. The only requirement is that the field of view contains two reference markers with known scale and with known position relative to the channel geometry, therefore operation and maintenance costs are very low. The other advantage of using smartphones, is that the data collected can be immediately sent via SMS to a central database. This

  14. 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.

  15. 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

  16. Evaluation of flash-flood discharge forecasts in complex terrain using precipitation

    USGS Publications Warehouse

    Yates, D.; Warner, T.T.; Brandes, E.A.; Leavesley, G.H.; Sun, Jielun; Mueller, C.K.

    2001-01-01

    Operational prediction of flash floods produced by thunderstorm (convective) precipitation in mountainous areas requires accurate estimates or predictions of the precipitation distribution in space and time. The details of the spatial distribution are especially critical in complex terrain because the watersheds are generally small in size, and small position errors in the forecast or observed placement of the precipitation can distribute the rain over the wrong watershed. In addition to the need for good precipitation estimates and predictions, accurate flood prediction requires a surface-hydrologic model that is capable of predicting stream or river discharge based on the precipitation-rate input data. Different techniques for the estimation and prediction of convective precipitation will be applied to the Buffalo Creek, Colorado flash flood of July 1996, where over 75 mm of rain from a thunderstorm fell on the watershed in less than 1 h. The hydrologic impact of the precipitation was exacerbated by the fact that a significant fraction of the watershed experienced a wildfire approximately two months prior to the rain event. Precipitation estimates from the National Weather Service's operational Weather Surveillance Radar-Doppler 1988 and the National Center for Atmospheric Research S-band, research, dual-polarization radar, colocated to the east of Denver, are compared. In addition, very short range forecasts from a convection-resolving dynamic model, which is initialized variationally using the radar reflectivity and Doppler winds, are compared with forecasts from an automated-algorithmic forecast system that also employs the radar data. The radar estimates of rain rate, and the two forecasting systems that employ the radar data, have degraded accuracy by virtue of the fact that they are applied in complex terrain. Nevertheless, the radar data and forecasts from the dynamic model and the automated algorithm could be operationally useful for input to surface

  17. Comparison of bed form variance spectra within a meander bend during flood and average discharge.

    USGS Publications Warehouse

    Levey, R.A.; Kjerfve, B.; Getzen, R.T.

    1980-01-01

    Time series analysis of streambed elevation in a meander bend along the Congaree River was used to determine the changes in bed form population succeeding a 16-year flood event. Variance spectra computed for a 595m longitudinal profile indicate that: a) the bed form variance for the flood record is significantly greater for all wavelengths from 5 to 30m; b) no well-demarcated bed form classes were present during the survey times, pointing to the possible existence of a continuum of bed form sizes rather than well-defined classes; and c) bed forms produced by the flood discharge were rapidly altered as the stage returned toward average level. -from Authors

  18. Technique for estimating the 2- to 500-year flood discharges on unregulated streams in rural Missouri

    USGS Publications Warehouse

    Alexander, Terry W.; Wilson, Gary L.

    1995-01-01

    A generalized least-squares regression technique was used to relate the 2- to 500-year flood discharges from 278 selected streamflow-gaging stations to statistically significant basin characteristics. The regression relations (estimating equations) were defined for three hydrologic regions (I, II, and III) in rural Missouri. Ordinary least-squares regression analyses indicate that drainage area (Regions I, II, and III) and main-channel slope (Regions I and II) are the only basin characteristics needed for computing the 2- to 500-year design-flood discharges at gaged or ungaged stream locations. The resulting generalized least-squares regression equations provide a technique for estimating the 2-, 5-, 10-, 25-, 50-, 100-, and 500-year flood discharges on unregulated streams in rural Missouri. The regression equations for Regions I and II were developed from stream-flow-gaging stations with drainage areas ranging from 0.13 to 11,500 square miles and 0.13 to 14,000 square miles, and main-channel slopes ranging from 1.35 to 150 feet per mile and 1.20 to 279 feet per mile. The regression equations for Region III were developed from streamflow-gaging stations with drainage areas ranging from 0.48 to 1,040 square miles. Standard errors of estimate for the generalized least-squares regression equations in Regions I, II, and m ranged from 30 to 49 percent.

  19. Main-channel slopes of selected streams in Iowa for estimation of flood-frequency discharges

    USGS Publications Warehouse

    Eash, David A.

    2003-01-01

    This report describes a statewide study conducted to develop main-channel slope (MCS) curves for 138 selected streams in Iowa with drainage areas greater than 100 square miles. MCS values determined from the curves can be used in regression equations for estimating floodfrequency discharges. Multivariable regression equations previously developed for two of the three hydrologic regions defined for Iowa require the measurement of MCS. Main-channel slope is a difficult measurement to obtain for large streams using 1:24,000-scale topographic maps. The curves developed in this report provide a simplified method for determining MCS values for sites located along large streams in Iowa within hydrologic Regions 2 and 3. The curves were developed using MCS values quantified for 2,058 selected sites along 138 selected streams in Iowa. A geographic information system (GIS) technique and 1:24,000-scale topographic data were used to quantify MCS values for the stream sites. The sites were selected at about 5-mile intervals along the streams. River miles were quantified for each stream site using a GIS program. Data points for river-mile and MCS values were plotted and a best-fit curve was developed for each stream. An adjustment was applied to all 138 curves to compensate for differences in MCS values between manual measurements and GIS quantifications. The multivariable equations for Regions 2 and 3 were developed using manual measurements of MCS. A comparison of manual measurements and GIS quantifications of MCS indicates that manual measurements typically produce greater values of MCS compared to GIS quantifications. Median differences between manual measurements and GIS quantifications of MCS are 14.8 and 17.7 percent for Regions 2 and 3, respectively. Comparisons of percentage differences between flood-frequency discharges calculated using MCS values of manual measurements and GIS quantifications indicate that use of GIS values of MCS for Region 3 substantially

  20. Discharge Estimation Using Satellite Gravity During Flood Seasons at the Óbidos Gauge Station, Amazon River

    NASA Astrophysics Data System (ADS)

    Eom, J.; Seo, K. W.; Lee, Y. K.

    2014-12-01

    Reliable measurement of river discharge is important for management of water resource and understanding of hydrological cycles particularly associated with global and regional climate changes. Practically, to obtain continuous time series of river discharge, regression analysis of an empirical relationship between accumulated water level and discharge data is used. During wet season, however, the relationship includes more uncertainty due to the difficulty of accurate discharge measurement. This is particularly true for the Amazon River because significant amount of water flows outside river channel during flooding. For an alternative way to estimate river discharge, we use GRACE time-varying gravity measurement from January 2003 to December 2012. We first apply Empirical Orthogonal Function (EOF) for GRACE time-varying gravity fields in Amazon and successfully isolate gravity signal in the main stream. The EOF time series represents relative river discharge variations without larger uncertainty during flooding season compared to conventional in-situ discharge estimate. Estimates of Amazon River discharge based on GRACE data are very close to those from observed at gauge stations during dry seasons. However, our estimates are larger than in-situ data in high water seasons, and the difference is the maximum at the 2009 flooding. This is probably because in-situ observation underestimates river discharge during wet season due possibly to detoured water in river pathway developed during flooding while GRACE observes integrated water mass variations in river channels.

  1. Accidental discharge of a Halon 1301 total flooding fire extinguishing system

    SciTech Connect

    Sass-Kortsak, A.M.; Holness, D.L.; Stopps, G.J.

    1985-11-01

    An accidental discharge of a total flooding Halon 1301 fire extinguishing system is described. The release of the Halon was accompanied by a sudden very loud noise, considerable air turbulence and a dense fog, resulting in worker anxiety and loss of visibility. The workers in the area at the time of the discharge reported higher frequencies of lightheadedness, headache, nasal complaints and disorientation than those entering the area later. Halon 1301 usually is regarded as having a low toxicity, although at concentrations above those used in occupied spaces, effects on consciousness and cardiac rhythm have been reported. In the present report no significant illness or injury due to the Halon exposure was found. A fine oily deposit found on horizontal surfaces in the area subsequent to the discharge consisted of mineral oil and iron, suggesting that this material was scoured out of the piping as the Halon discharged. The disorientation and anxiety produced by an accidental discharge can be minimized through education programs designed to ensure that personnel know what to expect and how to abort the discharge if it results from a false alarm. Situations leading to triggering of fire detectors by events other than fires should be investigated and reduced.

  2. 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)

  3. 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.

  4. Techniques for estimating flood-peak discharges of rural, unregulated streams in Ohio

    USGS Publications Warehouse

    Koltun, G.F.

    2003-01-01

    Regional equations for estimating 2-, 5-, 10-, 25-, 50-, 100-, and 500-year flood-peak discharges at ungaged sites on rural, unregulated streams in Ohio were developed by means of ordinary and generalized least-squares (GLS) regression techniques. One-variable, simple equations and three-variable, full-model equations were developed on the basis of selected basin characteristics and flood-frequency estimates determined for 305 streamflow-gaging stations in Ohio and adjacent states. The average standard errors of prediction ranged from about 39 to 49 percent for the simple equations, and from about 34 to 41 percent for the full-model equations. Flood-frequency estimates determined by means of log-Pearson Type III analyses are reported along with weighted flood-frequency estimates, computed as a function of the log-Pearson Type III estimates and the regression estimates. Values of explanatory variables used in the regression models were determined from digital spatial data sets by means of a geographic information system (GIS), with the exception of drainage area, which was determined by digitizing the area within basin boundaries manually delineated on topographic maps. Use of GIS-based explanatory variables represents a major departure in methodology from that described in previous reports on estimating flood-frequency characteristics of Ohio streams. Examples are presented illustrating application of the regression equations to ungaged sites on ungaged and gaged streams. A method is provided to adjust regression estimates for ungaged sites by use of weighted and regression estimates for a gaged site on the same stream. A region-of-influence method, which employs a computer program to estimate flood-frequency characteristics for ungaged sites based on data from gaged sites with similar characteristics, was also tested and compared to the GLS full-model equations. For all recurrence intervals, the GLS full-model equations had superior prediction accuracy relative to

  5. Global and local scale flood discharge simulations in the Rhine River basin for flood risk reduction benchmarking in the Flagship Project

    NASA Astrophysics Data System (ADS)

    Gädeke, Anne; Gusyev, Maksym; Magome, Jun; Sugiura, Ai; Cullmann, Johannes; Takeuchi, Kuniyoshi

    2015-04-01

    The global flood risk assessment is prerequisite to set global measurable targets of post-Hyogo Framework for Action (HFA) that mobilize international cooperation and national coordination towards disaster risk reduction (DRR) and requires the establishment of a uniform flood risk assessment methodology on various scales. To address these issues, the International Flood Initiative (IFI) has initiated a Flagship Project, which was launched in year 2013, to support flood risk reduction benchmarking at global, national and local levels. In the Flagship Project road map, it is planned to identify the original risk (1), to identify the reduced risk (2), and to facilitate the risk reduction actions (3). In order to achieve this goal at global, regional and local scales, international research collaboration is absolutely necessary involving domestic and international institutes, academia and research networks such as UNESCO International Centres. The joint collaboration by ICHARM and BfG was the first attempt that produced the first step (1a) results on the flood discharge estimates with inundation maps under way. As a result of this collaboration, we demonstrate the outcomes of the first step of the IFI Flagship Project to identify flood hazard in the Rhine river basin on the global and local scale. In our assessment, we utilized a distributed hydrological Block-wise TOP (BTOP) model on 20-km and 0.5-km scales with local precipitation and temperature input data between 1980 and 2004. We utilized existing 20-km BTOP model, which is applied globally, and constructed the local scale 0.5-km BTOP model for the Rhine River basin. For the BTOP model results, both calibrated 20-km and 0.5-km BTOP models had similar statistical performance and represented observed flood river discharges, epecially for 1993 and 1995 floods. From 20-km and 0.5-km BTOP simulation, the flood discharges of the selected return period were estimated using flood frequency analysis and were comparable to

  6. Flooding in Myanmar: joint occurrence of high discharges and high sea water levels?

    NASA Astrophysics Data System (ADS)

    Bouaziz, Laurène; Sperna Weiland, Frederiek; Vatvani, Deepak; Diermanse, Ferdinand

    2016-04-01

    In the summer of 2015 serious flooding occurred in Myanmar when cyclone Komen made landfall in Bangladesh, bringing strong winds and heavy rains to Myanmar. The cyclone struck the country during the monsoon season and resulted in widespread flooding, temporarily displacing over 1.6 million people. It was hypothesized that there could be a relation between occurrences of storm surges and extreme discharges in Myanmar. Comparable studies have shown that dependence between storm surge at Hoek van Holland in the Netherlands and high river discharges of the Rhine at Lobith exist with a lag of 6 days (Klerk et. al, 2015). The processes generating high discharges in the Ayeyarwady river and storm surges along the Myanmar coast were analyzed using global precipitation data (EU FP7 eartH2Observe), a distributed wflow-sbm hydrological model of the Ayeyarwady and a global storm surge model. About 15 historical tropical storms and hurricanes affecting Myanmar since 1992 were analyzed in terms of rainfall distribution over the country, discharged river flow volumes and storm surge extent and magnitude. All storms except for Komen in 2015 occurred between October and May, which does not coincide with the monsoon season (mainly June, July and August). The intensities and the paths of the 15 studied cyclones varied considerably and largely affected the spatial extent and the magnitude of storm surges. The study showed that high Ayeyarwady river flows and high surges generally do not coincide for the following reasons: the large scale of the river basin, the estimated one week travel time of water from the upstream catchment to the mouth, the occurrence of the majority of historical storms outside the monsoon season and the (relatively) limited spatial extent of a storm surge (at the scale of Myanmar). While the applied method is deemed successful for the identification of joint probabilities of surges and river discharges, this study indicates that such analyses are more relevant

  7. Techniques for estimating flood-frequency discharges for streams in Iowa

    USGS Publications Warehouse

    Eash, David A.

    2001-01-01

    Techniques for estimating flood-frequency discharges for streams in Iowa are presented for determining (1) regional regression estimates for ungaged sites on ungaged streams; (2) weighted estimates for gaged sites; and (3) weighted estimates for ungaged sites on gaged streams. The technique for determining regional regression estimates for ungaged sites on ungaged streams requires determining which of four possible examples applies to the location of the stream site and its basin. Illustrations for determining which example applies to an ungaged stream site and for applying both the one-variable and multi-variable regression equations are provided for the estimation techniques.

  8. A systematic test of surface velocity radar (SVR) to improve flood discharge prediction

    NASA Astrophysics Data System (ADS)

    Zolezzi, G.; Zamler, D.; Laronne, J. B.; Salvaro, M.; Piazza, F.; Le Coz, J.; Welber, M.; Dramais, G.

    2011-12-01

    Measurement of streamflow at flood stage is normally prohibitive and is therefore not a standard task performed by hydrographic offices. Streamflow estimation at high stages is commonly achieved through transformation of gauged water levels to discharge through rating curves. These stage-discharge relationships often suffer from large errors especially above the highest gauged discharge values corresponding to morphologically formative conditions. Non-contact methods based on radar Doppler technology have recently emerged as promising options because they can remotely measure the surface water velocity without requiring contact of instruments with the stream. They have been used for more than a decade, notably in Japan, but they are expensive and are fixed with the radar beam directed to a small portion of the free surface width. The aim of our study is to test a portable, cheap, easy-to-apply radar-based technique (SVR: Surface Velocity Radar). We illustrate the outcomes of a systematic series of field campaigns performed in Israel, Italy and France with concomitant standard (mechanical and electromagnetic current meter) and modern (ADCP, LSPIV image analysis) techniques with cooperating regional authorities. The SVR has been deployed from bridges and/or channel banks on 5 different streams: the single-thread Adige and the braided Tagliamento rivers (NE Italy) the single-thread Arc-en-Maurienne River during reservoir flushing (French Alps) and the ephemeral, flashflood Wadi Eshtemoa and a small perennial stream at Ein-Fesh'ha springs (Israel). This has allowed to span a relatively broad range of discharge (1 to ~ 600 m3/s), flow velocity (0.5 to ~ 3.5 m/s) and ratio between bed roughness height to flow depth (~ 0.01 to ~ 0.5) while measuring both under steady and rapidly varying flow conditions. The key outcomes of the field campaigns are: (i) wherever a bridge is available and cross-sectional topography can be measured before and/or after a flood, comparable

  9. Flood of December 25, 1987, in Millington, Tennessee and vicinity

    USGS Publications Warehouse

    Lewis, James G.; Gamble, Charles R.

    1989-01-01

    Intense rainfall totaling 9.2 in. in a 12-hour period on December 24-25, 1987, and 14.8 in for the period December 24-27 caused record floods in Millington, Tennessee and vicinity. The peak discharge of Big Creek at Raleigh-Millington Road was almost twice the discharge of the 100-year flood discharge and that of Loosahatchie River near Arlington was about equal to the 50-year flood discharge. The inundated area and flood elevations are depicted on a map of Millington, Tennessee and vicinity. Water surface profiles for the peak of December 25, 1987, for Loosahatchie River, Big Creek, Royster Creek, North Fork Creek, Casper Creek, and an unnamed tributary to Big Creek are shown. Flood damages and cleanup costs for this record flood have been estimated at about $9.2 million. (USGS)

  10. Flood of June 18, 1978, on Honey Creek tributary at Thornville, Ohio

    USGS Publications Warehouse

    Webber, Earl E.; Mayo, Ronald I.

    1980-01-01

    A high-intensity summer rain estimated at 8 inches in 2 hours caused flooding on a small stream near Thornville, Ohio, destroying a culvert and highway fill on State Highway 188. Computation of peak discharges of 3,250 cubic feet per second above and 4,050 cubic feet per second below the culvert indicates a greater than 100-year flood. (USGS)

  11. Floods of May and June 2008 in Iowa

    USGS Publications Warehouse

    Buchmiller, Robert C.; Eash, David A.

    2010-01-01

    An unusually wet winter and spring of 2007 to 2008 resulted in extremely wet antecedent conditions throughout most of Iowa. Rainfall of 5 to 15 inches was observed in eastern Iowa during May 2008, and an additional 5 to 15 inches of rain was observed throughout most of Iowa in June. Because of the severity of the May and June 2008 flooding, the U.S. Geological Survey, in cooperation with other Federal, State, and local agencies, has summarized the meteorological and hydrological conditions leading to the flooding, compiled flood-peak stages and discharges, and estimated revised flood probabilities for 62 selected streamgages. Record peak discharges or flood probabilities of 1 percent or smaller (100-year flooding or greater) occurred at more than 60 streamgage locations, particularly in eastern Iowa. Cedar Rapids, Decorah, Des Moines, Iowa City, Mason City, and Waterloo were among the larger urban areas affected by this flooding. High water and flooding in small, headwater streams in north-central and eastern Iowa, particularly in June, combined and accumulated in large, mainstem rivers and resulted in flooding of historic proportions in the Cedar and Iowa Rivers. Previous flood-peak discharges at many locations were exceeded by substantial amounts, in some cases nearly doubling the previous record peak discharge at locations where more than 100 years of streamflow record are available.

  12. Methods for predicting peak discharge of floods caused by failure of natural and constructed earthen dams

    USGS Publications Warehouse

    Walder, J.S.; O'Connor, J. E.

    1997-01-01

    Floods from failures of natural and constructed dams constitute a widespread hazard to people and property. Expeditious means of assessing flood hazards are necessary, particularly in the case of natural dams, which may form suddenly and unexpectedly. We revise statistical relations (derived from data for past constructed and natural dam failures) between peak discharge (Q(p)) and water volume released (V(0)) or drop in lake level (d) but assert that such relations, even when cast into a dimensionless form, are of limited utility because they fail to portray the effect of breach-formation rate. We then analyze a simple, physically based model of dam-breach formation to show that the hydrograph at the breach depends primarily on a dimensionless parameter ?? = kV0/g1/2d7/2, where k is the mean erosion rate of the breach and g is acceleration due to gravity. The functional relationship between Q(p) and ?? takes asymptotically distinct forms depending on whether ?? << 1 (relatively slow breach formation or small lake volume) or ?? >> 1 (relatively fast breach formation or large lake volume). Theoretical predictions agree well with data from dam failures for which k, and thus ??, can be estimated. The theory thus provides a rapid means of predicting the plausible range of values of peak discharge at the breach in an earthen dam as long as the impounded water volume and the water depth at the dam face can be estimated.

  13. 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.

  14. 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

  15. Data for floods of May 1978 in northeastern Wyoming and southeastern Montana

    USGS Publications Warehouse

    Parrett, Charles; Carlson, D.D.; Craig, G.S., Jr.; Hull, J.A.

    1978-01-01

    Severe flooding in northeastern Wyoming and southeastern Montana in May 1978 is described by tables of data, graphs, and photographs. Flood peaks were determined at 162 sites in the flooded area. At most of the sites, peak discharges were determined from existing stage-discharge relationship curves, and at 30 of the sites indirect flow measurements were made. At 19 sites, the May 1978 peak discharge exceeded the previous peak of record and also exceeded the computed 100-year frequency flood. (Woodard-USGS)

  16. Hydraulics of outburst floods spilling over a steep-walled canyon: Implications for paleo-discharges on Mars

    NASA Astrophysics Data System (ADS)

    Lapotre, Mathieu; Lamb, Michael

    2013-04-01

    Canyons carved by outburst floods are common landforms on Earth and Mars. These canyons are generally found in fractured basalts and jointed sedimentary rocks. Flood-carved canyons commonly have steep headwalls and a roughly constant width, and are often thought to have formed from upstream headwall propagation due to waterfall erosion. Because morphology is readily available from satellite imagery, these canyons offer a unique opportunity to quantify the discharge of rare, catastrophic paleo-floods on Earth and Mars. However, mechanistic relationships that relate canyon size to flood discharge have yet to be developed. We propose that the width of a canyon headwall in fractured rock is set by the spatial distribution of erosion around the rim of the canyon, which is controlled by the distribution of shear stresses induced by the overflowing water as it is focused into the canyon head. We test this hypothesis by performing a series of numerical simulations of flood-water focusing using ANUGA Hydro, a 2D-depth averaged, fully turbulent, hydraulic numerical modeling suite allowing for Froude-number transitions. The numerical simulations were designed to explore five dimensionless variables: the aspect ratio of the canyon (length normalized by width), the canyon width to flood-water width ratio, the canyon width to normal-flow depth ratio, the Froude number, and the topographic gradient upstream of the canyon. Preliminary results show that flow focusing leads to increased shear stresses at the canyon head compared to the sides of the canyon for subcritical floods and higher canyon aspect ratios. This suggests that proto-canyons start growing from a topographic defect in all directions until they reach a critical length for the side walls to dry. Once this critical length is attained, canyons focus most of the flood waters into their heads, and propagate upstream only, maintaining roughly constant widths. Preliminary results suggest that canyon width may be used to

  17. The October 2015 flash - floods in south eastern France: first discharge estimations and comparison with other flash-floods documented in the framework of the Hymex project

    NASA Astrophysics Data System (ADS)

    Payrastre, Olivier; Lebouc, Laurent; Ayral, Pierre Alain; Brunet, Pascal; Delrieu, Guy; Douvinet, Johnny; Dramais, Guillaume; Javelle, Pierre; Johannet, Anne; Adamovic, Marko; Adnes, Cyriel; Cantet, Philippe; Chapuis, Margot; Coutouis, Adrien; Creutin, Jean-Dominique; Gonzalez-Sosa, Enrique; Ruin, Isabelle; Saint-Martin, Clotilde; Shabou, Saif; Whilhelm, Bruno

    2016-04-01

    On the 3rd of October 2015, an outstanding hydrometeorological event hit the Mediterranean coast in the Alpes-Maritimes region in south-eastern France. Despite this rainstorm event was very short in time (approximatively 2 hours of intense rainfall), it caused a large rainfall accumulation reaching up to 180 mm. Intense flash floods were observed on all rivers of the affected area, including mostly small watersheds of less than 60 km². They caused 21 fatalities and particularly high damages because of the density of urban areas located in the downstream coastal part of the affected area. The towns of Mandelieu, Cannes, and Antibes were particularly affected. On several watersheds, the reported floods seem be the largest observed from human memory, and may therefore become reference events for flood risk prevention. A post event survey was organised in the framework of the Hymex project in order to document the characteristics of the floods which occurred in a large majority on ungauged rivers, and also destroyed some of the existing stream gauges. A total of 36 peak discharge values were estimated, enabling a detailed description of observed hydrological reactions. This dataset confirms the very large peak discharge values, which remain however significantly below the magnitude of other recent floods observed in other regions of France, and below the existing envelope curves. It may also be observed that the magnitude of this new event is relatively close to what was observed in june 2010 in the nearby Var region. These two events, both being among the largest observed locally from human memory, suggest that the position of the envelope curve should be lower in this eastern part of the French Mediterranean coast, if compared to the Cevennes region which fixes up to now the position of the envelope curve for the whole French territory. A rainfall-runoff analysis of this flood is now in progress to confirm that the runoff rates are not particularly high if compared

  18. Peak discharge on Bull Creek and tributaries, Scurry and Borden Counties, Texas, flood of April 12, 13, 1954

    USGS Publications Warehouse

    McDaniels, L.L.

    1954-01-01

    This report contains a description of the rainfall pattern producing the flood of April 12, 13, 1954, in the Bull Creek watershed, the results of indirect determinations of peak discharges and estimates of flows at several points in that watershed, and a comparison of the peak stage at the discontinued gaging station on Bull Creek near Ira, Tex., with other floods on record. Field work consisted of transit-stadia surveys at five locations to develop high-water profiles and cross-sections, performed within two weeks after flood occurred.

  19. Techniques for estimating flood peak discharges for unregulated streams and streams regulated by small floodwater retarding structures in Oklahoma

    USGS Publications Warehouse

    Tortorelli, R.L.; Bergman, D.L.

    1985-01-01

    Statewide regression relations for Oklahoma were determined for estimating peak discharge of floods for selected recurrence intervals from 2 to 500 years. The independent variables required for estimating flood discharge for rural streams are contributing drainage area and mean annual precipitation. Main-channel slope, a variable used in previous reports, was found to contribute very little to the accuracy of the relations and was not used. The regression equations are applicable for watersheds with drainage areas less than 2,500 square miles that are not significantly affected by regulation from manmade works. These relations are presented in graphical form for easy application. Limitations on the use of the regression relations and the reliability of regression estimates for rural unregulated streams are discussed. Basin and climatic characteristics, log-Pearson Type III statistics and the flood-frequency relations for 226 gaging stations in Oklahoma and adjacent states are presented. Regression relations are investigated for estimating flood magnitude and frequency for watersheds affected by regulation from small FRS (floodwater retarding structures) built by the U.S. Soil Conservation Service in their watershed protection and flood prevention program. Gaging-station data from nine FRS regulated sites in Oklahoma and one FRS regulated site in Kansas are used. For sites regulated by FRS, an adjustment of the statewide rural regression relations can be used to estimate flood magnitude and frequency. The statewide regression equations are used by substituting the drainage area below the FRS, or drainage area that represents the percent of the basin unregulated, in the contributing drainage area parameter to obtain flood-frequency estimates. Flood-frequency curves and flow-duration curves are presented for five gaged sites to illustrate the effects of FRS regulation on peak discharge.

  20. 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.

  1. Evaluation of the satellite-based Global Flood Detection System for measuring river discharge: influence of local factors

    NASA Astrophysics Data System (ADS)

    Revilla-Romero, B.; Thielen, J.; Salamon, P.; De Groeve, T.; Brakenridge, G. R.

    2014-11-01

    One of the main challenges for global hydrological modelling is the limited availability of observational data for calibration and model verification. This is particularly the case for real-time applications. This problem could potentially be overcome if discharge measurements based on satellite data were sufficiently accurate to substitute for ground-based measurements. The aim of this study is to test the potentials and constraints of the remote sensing signal of the Global Flood Detection System for converting the flood detection signal into river discharge values. The study uses data for 322 river measurement locations in Africa, Asia, Europe, North America and South America. Satellite discharge measurements were calibrated for these sites and a validation analysis with in situ discharge was performed. The locations with very good performance will be used in a future project where satellite discharge measurements are obtained on a daily basis to fill the gaps where real-time ground observations are not available. These include several international river locations in Africa: the Niger, Volta and Zambezi rivers. Analysis of the potential factors affecting the satellite signal was based on a classification decision tree (random forest) and showed that mean discharge, climatic region, land cover and upstream catchment area are the dominant variables which determine good or poor performance of the measurement sites. In general terms, higher skill scores were obtained for locations with one or more of the following characteristics: a river width higher than 1km; a large floodplain area and in flooded forest, a potential flooded area greater than 40%; sparse vegetation, croplands or grasslands and closed to open and open forest; leaf area index > 2; tropical climatic area; and without hydraulic infrastructures. Also, locations where river ice cover is seasonally present obtained higher skill scores. This work provides guidance on the best locations and limitations

  2. Evaluation of the satellite-based Global Flood Detection System for measuring river discharge: influence of local factors

    NASA Astrophysics Data System (ADS)

    Revilla-Romero, B.; Thielen, J.; Salamon, P.; De Groeve, T.; Brakenridge, G. R.

    2014-07-01

    One of the main challenges for global hydrological modelling is the limited availability of observational data for calibration and model verification. This is particularly the case for real time applications. This problem could potentially be overcome if discharge measurements based on satellite data were sufficiently accurate to substitute for ground-based measurements. The aim of this study is to test the potentials and constraints of the remote sensing signal of the Global Flood Detection System for converting the flood detection signal into river discharge values. The study uses data for 322 river measurement locations in Africa, Asia, Europe, North America and South America. Satellite discharge measurements were calibrated for these sites and a validation analysis with in situ discharge was performed. The locations with very good performance will be used in a future project where satellite discharge measurements are obtained on a daily basis to fill the gaps where real time ground observations are not available. These include several international river locations in Africa: Niger, Volta and Zambezi rivers. Analysis of the potential factors affecting the satellite signal was based on a classification decision tree (Random Forest) and showed that mean discharge, climatic region, land cover and upstream catchment area are the dominant variables which determine good or poor performance of the measurement sites. In general terms, higher skill scores were obtained for locations with one or more of the following characteristics: a river width higher than 1 km; a large floodplain area and in flooded forest; with a potential flooded area greater than 40%; sparse vegetation, croplands or grasslands and closed to open and open forest; Leaf Area Index > 2; tropical climatic area; and without hydraulic infrastructures. Also, locations where river ice cover is seasonally present obtained higher skill scores. The work provides guidance on the best locations and limitations

  3. 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 ...

  4. Effectiveness of water infrastructure for river flood management - Part 1: Flood hazard assessment using hydrological models in Bangladesh

    NASA Astrophysics Data System (ADS)

    Gusyev, M. A.; Kwak, Y.; Khairul, M. I.; Arifuzzaman, M. B.; Magome, J.; Sawano, H.; Takeuchi, K.

    2015-06-01

    This study introduces a flood hazard assessment part of the global flood risk assessment (Part 2) conducted with a distributed hydrological Block-wise TOP (BTOP) model and a GIS-based Flood Inundation Depth (FID) model. In this study, the 20 km grid BTOP model was developed with globally available data on and applied for the Ganges, Brahmaputra and Meghna (GBM) river basin. The BTOP model was calibrated with observed river discharges in Bangladesh and was applied for climate change impact assessment to produce flood discharges at each BTOP cell under present and future climates. For Bangladesh, the cumulative flood inundation maps were produced using the FID model with the BTOP simulated flood discharges and allowed us to consider levee effectiveness for reduction of flood inundation. For the climate change impacts, the flood hazard increased both in flood discharge and inundation area for the 50- and 100-year floods. From these preliminary results, the proposed methodology can partly overcome the limitation of the data unavailability and produces flood~maps that can be used for the nationwide flood risk assessment, which is presented in Part 2 of this study.

  5. 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.

  6. Discharge forecasting using MODIS and radar altimetry: potential application for transboundary flood risk management in Niger-Benue River basin

    NASA Astrophysics Data System (ADS)

    Tarpanelli, Angelica; Amarnath, Giriraj; Brocca, Luca; Moramarco, Tommaso

    2016-04-01

    Flooding is one of most widespread natural disasters in the world. Its impact is particularly severe and destructive in Asia and Africa, because the living conditions of some settlements are inadequate to cope with this type of natural hazard. In this context, the estimation of discharge is extremely important to address water management and flood risk assessment. However, the inadequate monitoring network hampers any control and prediction activity that could improve these disastrous situations. In the last few years, remote sensing sensors have demonstrated their effectiveness in retrieving river discharge, especially in supporting discharge nowcasting and forecasting activities. Recently, the potential of radar altimetry was apparent when used for estimating water levels in an ungauged river site with good accuracy. It has also become a very useful tool for estimation and prediction of river discharge. However, the low temporal resolution of radar altimeter observations (10 or 35 days, depending on the satellite mission) may be not suitable for day-by-day hydrological forecasting. Differently, MODerate resolution Imaging Spectroradiometer (MODIS), considering its proven potential for quantifying the variations in discharge of the rivers at daily time resolution may be more suited to this end. For these reasons, MODIS and radar altimetry data were used in this study to predicting and forecasting the river discharge along the Niger-Benue River, where severe flooding with extensive damage to property and loss of lives occurred. Therefore, an effective method to forecast flooding can support efforts towards creating an early warning system. In order to estimate river discharge, four MODIS products (daily, 8-day, and from AQUA and TERRA satellites) connected at three sites (two gauged and one ungauged) were used. The capability of remote sensing sensors to forecast discharge a few days in advance at a downstream section using MODIS and ENVISAT radar altimetry data

  7. Floods in the Canadian and Pecos River Basins of New Mexico, May and June 1937, with summary of flood discharges in New Mexico

    USGS Publications Warehouse

    Dalrymple, Tate

    1939-01-01

    In May and June floods occurred in the Canadian and Pecos River Basins of New Mexico that were unusually high and in many places were record breaking. The floods were caused by heavy rains that occurred over the eastern part of the State from May 23 to June 4 in a series of intense and intermittent storms. During these storms of the cloudburst type as much as 12 inches of rain fell in the 13-day period, and a fall of 7 inches in 2 hours and 40 minutes was reported from the vicinity of Clayton. Heavy rains also fell in the mountainous region west of Roswell, amounting to as much as l0 inches at some places. Much of the region that had excessive rainfall is relatively flat and has no well-defined drainage system. From these areas there was very little run-off and practically no water was contributed to the major streams. Hail fell at many places in eastern New Mexico, causing damage to crops, livestock, and other property. Hail fell somewhere in the Canadian and Pecos River Basins almost every day during the storm period, but the duration of the fall was generally short. The largest hailstones were reported from Clayton, where one stone measured 8 inches in circumference and weighed 9 ounces; at Centerville, where reports state that some stones were 9 to 10 inches in circumference; and near Roswell, where it was reported that six stones would fill a gallon bucket. The Canadian River flood reached a peak at Logan of 110,000 second-feet, which has been exceeded in this century only by the floods of 1904, 1909, and 1914. The total run-off at Logan for the flood period has been computed as 653,800 acre-feet. At Santa Rosa the Pecos River reached a maximum discharge of 88,200 second-feet, which is greater than any previously recorded. This flood was partly stored in the Alamogordo Reservoir; the peak below the reservoir was only 25,200 second-feet. The Pecos River flood at Roswell reached a maximum discharge of more than 80,000 second-feet. This water came mostly from

  8. 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

  9. Techniques for estimating flood discharges for Oklahoma streams; techniques for calculating magnitude and frequency of floods in Oklahoma from rural and urban areas under 2500 square miles, with compilations of flood data through 1975

    USGS Publications Warehouse

    Thomas, W.O.; Corley, R.K.

    1977-01-01

    Statewide regression equations are defined for estimating peak discharges of floods having recurrence intervals ranging from 2 to 500 years. Contributing drainage area, main-channel slope and mean annual precipitation are the independent variables required for estimating flood discharges for rural streams. For urban streams the percentage of the basin that is impervious and served by storm sewers also is required. The regression equations are applicable for watersheds draining less than 2,500 square miles (6,500 square kilometers) that are not significantly affected by regulation. For the rural streams, the regression equations are presented in graphical form for easy application. Calibration of the U.S. Geological Survey rainfall-runoff model and synthesis of long-term annual peak data for 60 small watersheds is discussed. Synthetic frequency curves, generated using six long-term rainfall stations, are combined into one frequency curve and weighted with the observed frequency curve at each site. Use of the rainfall-runoff model parameters to estimate flood discharges reduces the standard error for selected frequencies by 9-12 percent. However, collection of the necessary rainfall-runoff data to determine the model parameters is time consuming and expensive. Annual peak data, basin and climatic characteristics, log-Pearson Type III statistics, and the flood-frequency relations are presented for 188 gaging stations. (PHOTOSTATIC COPIES ONLY ARE AVAILABLE OF THIS REPORT)

  10. Methods for estimating annual exceedance-probability discharges and largest recorded floods for unregulated streams in rural Missouri

    USGS Publications Warehouse

    Southard, Rodney E.; Veilleux, Andrea G.

    2014-01-01

    Regression analysis techniques were used to develop a set of equations for rural ungaged stream sites for estimating discharges with 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities, which are equivalent to annual flood-frequency recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years, respectively. Basin and climatic characteristics were computed using geographic information software and digital geospatial data. A total of 35 characteristics were computed for use in preliminary statewide and regional regression analyses. Annual exceedance-probability discharge estimates were computed for 278 streamgages by using the expected moments algorithm to fit a log-Pearson Type III distribution to the logarithms of annual peak discharges for each streamgage using annual peak-discharge data from water year 1844 to 2012. Low-outlier and historic information were incorporated into the annual exceedance-probability analyses, and a generalized multiple Grubbs-Beck test was used to detect potentially influential low floods. Annual peak flows less than a minimum recordable discharge at a streamgage were incorporated into the at-site station analyses. An updated regional skew coefficient was determined for the State of Missouri using Bayesian weighted least-squares/generalized least squares regression analyses. At-site skew estimates for 108 long-term streamgages with 30 or more years of record and the 35 basin characteristics defined for this study were used to estimate the regional variability in skew. However, a constant generalized-skew value of -0.30 and a mean square error of 0.14 were determined in this study. Previous flood studies indicated that the distinct physical features of the three physiographic provinces have a pronounced effect on the magnitude of flood peaks. Trends in the magnitudes of the residuals from preliminary statewide regression analyses from previous studies confirmed that regional analyses in this study were

  11. Flood-plain delineation for Cub Run basin, Fairfax County, Virginia

    USGS Publications Warehouse

    Soule, Pat LeRoy

    1978-01-01

    Flood-plain delineation for Cub Run basin water-surface profiles of the 25-, 50-, and 100-year recurrence interval discharges have been computed for all streams and reaches of channels in Fairfax County, Virginia having a drainage area greater than 1 square mile except for Dogue Creek, Little Hunting Creek, and that part of the Cameron Run above Lake Barcroft. Maps having a 2-foot contour interval and a horizontal scale of 1 inch equals 100 feet have been used for base on which flood boundaries were delineated for 25-, 50-, and 100-year floods to be expected in each basin under ultimate development conditions. This report is one of a series and presents a discussion of techniques employed in computing discharges and profiles as well as the flood profiles and maps on which flood boundaries have been delineated for the Cub Run basin in Fairfax County. (Woodard-USGS)

  12. Flood-plain delineation for Cameron Run Basin, Fairfax County-Alexandria City, Virginia

    USGS Publications Warehouse

    Soule, Pat L.

    1976-01-01

    Flood-Plain Delineation for Cameron Run Basin Water-surface profiles of the 25-, 50-, and 100-year recurrence interval discharges have been computed for all streams and reaches of channels in Fairfax County, Virginia, having a drainage area greater than 1 square mile except for Dogue Creek, Little Hunting Creek, and that part of Cameron Run above Lake Barcroft. Maps having a 2-foot contour interval and a horizontal scale of 1 inch equals 100 feet have been used for a base on which flood boundaries were delineated for 25-, 50-, and 100-year floods to be expected in each basin under ultimate development conditions. Included are techniques employed in computing discharges and profiles as well as the flood profiles and maps on which flood boundaries have been delineated for that part of Cameron Run basin below Lake Barcroft in both Fairfax County and the city of Alexandria.

  13. Floods of June 17, 1990, and July 9, 1993, along Squaw Creek and the South Skunk River in Ames, Iowa, and vicinity

    USGS Publications Warehouse

    Einhellig, R.F.; Eash, D.A.

    1996-01-01

    Water-surface-elevation profiles and peak discharges for the floods of June 17, 1990, and July 9, 1993, along Squaw Creek and the South Skunk River, in Ames, Iowa, are presented in this report. The maximum flood-peak discharge of 24,300 cubic feet per second for the streamflow-gaging station on Squaw Creek at Ames, Iowa (station number 05470500) occurred on July 9, 1993. This discharge was 80 percent larger than the 100-year recurrence-interval discharge and exceeded the previous record flood-peak discharge of June 17, 1990, by 94 percent. The July 9, 1993, flood-peak discharge of 26,500 cubic feet per second on the South Skunk River below Squaw Creek (station number 05471000) was also a peak of record, exceeding the previous record flood-peak discharge of June 27, 1975, by 80 percent, and the 100-year recurrence-interval discharge by 60 percent. A flood history describes rainfall conditions for floods that occurred during 1990 and 1993. The report also includes information on flood stages and discharges and floodflow frequencies for the active gaging stations in the vicinity of Ames, Iowa, and on temporary bench marks and reference points in the Squaw Creek and South Skunk River Basins near Ames, Iowa.

  14. Calibration of floodplain roughness and estimation of flood discharge based on tree-ring evidence and hydraulic modelling

    NASA Astrophysics Data System (ADS)

    Ballesteros, J. A.; Bodoque, J. M.; Díez-Herrero, A.; Sanchez-Silva, M.; Stoffel, M.

    2011-06-01

    SummaryThe roughness calibration of floodplain and channels represents an important issue for flood studies. This paper discusses the genesis of scars on trees and their use as benchmarks in roughness calibration. In addition, it presents a methodology to reconstruct unrecorded flood discharge in the Alberche basin of the Spanish Central System. The study is based on the combined use of dendrogeomorphic evidence (i.e. scars on trees), data from the Navaluenga flow gauge (Avila Province) as well as a 1D/2D coupled numerical hydraulic model. A total of 49 scars have been analyzed with dendrogeomorphic techniques. Scar dates are in concert with seven flood events documented in the systematic record (i.e. 1989, 1993, 1996, 2000, 2002, 2003, and 2005). We were also able to identify an additional event dated to 1970, which is before the flow gauge was installed at Navaluenga. Based on the rating curve obtained from the flow gauge, cross-sectional area and data from hydraulic modelling, we cannot find a statistically significant difference between water depths registered at the flow gauge and scar heights on trees ( p-value > 0.05), indicating that scars would have been generated through the impact of floating wood and that scars on trees would represent a valuable and accurate proxy for water depth reconstruction. Under this premise, we have estimated the peak discharge of the 1970 flood event to 1684.3 ± 519.2 m 3 s -1; which renders this event the largest documented flood for the Alberche River at Navaluenga. In a last analytical step, we discuss the use of scars on trees as benchmark for roughness calibration in ungauged or shortly recorded basins and address the added value of dendrogeomorphic data in flood frequency analysis.

  15. 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.

  16. Constraints on the rate of discharge and duration of the Mangala Valles flood

    NASA Technical Reports Server (NTRS)

    Parker, T. J.; Gorsline, D. S.

    1993-01-01

    Interest in Mangala Valles remains high within the planetary science community. This is justified because the survey mission images provide us with nearly complete coverage of the system at high resolution. Upcoming high resolution topography from the Mars Observer Laser Altimeter will enable the application of flood discharge models with an unprecedented level of detail. Previous work on the Mangala Valles problem has relied on the available low resolution topography. This has limited the ability of workers to constrain discharge calculations to only within several-order-of-magnitude estimates. Local determinations of channel depths via shadow length measurements and photoclinometric profiling are much more accurate, but can only be applied to steep slopes (and/or low sun elevations) in the case of shadow measurements, or across relatively short distances (to avoid changes in albedo along asymmetric photoclinometric profiles). We are taking stereo parallax measurements from medium resolution Viking Orbiter images, which provide a valuable intermediate check of the topography between those measurements made thus far and the upcoming Mars Observer data. The images used are from orbits 034A and 637A, and cover Mangala Valles from the source graben in Memnonia Fossae to the beginning of the bifurcated reach (at 9.5 deg lat., 151.5 deg lon.). These images are about 300 m/pixel and 250 m/pixel, respectively. Both sets of images were orthographically projected to 250 m/pixel. The separation angle between left-right pairs is approximately 52 degrees. This results in a vertical accuracy on the order of plus or minus 260 m. Though this is still somewhat coarse, the channel relief is clearly resolved. Preliminary profiles across Mangala Valles and the large topographic ridge to the east are shown on the following page. An east-west regional tilt that resulted from slight scaling differences in the digital data has been 'removed' by visually estimating a regional datum on the

  17. 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

  18. Floods in Georgia, magnitude and frequency : techniques for estimating the magnitude and frequency of floods in Georgia with compilation of flood data through 1974

    USGS Publications Warehouse

    Price, McGlone

    1979-01-01

    Regional relations are defined for estimating the magnitude and frequency of floods having recurrence intervals of 2, 5, 10, 25, 50, and 100 years on streams with natural flow in Georgia. Multiple-regression analyses were used to define the relationship between the flood-discharge frequency of annual peak discharges for streams draining 0.1 to 1,000 square miles and 10 climatological and physical basin characteristics. The analyses indicate that the drainage area of the basin is the most significant characteristic. Five regions having distinct flood-discharge frequency characteristics are delineated. Individual relations of flood magnitude and frequency to drainage area are given for parts of the main stems of the major rivers without significant regulation draining more than 1,000 square miles. (Kosco-USGS)

  19. Flood frequency analysis of historical flood data under stationary and non-stationary modelling

    NASA Astrophysics Data System (ADS)

    Machado, M. J.; Botero, B. A.; López, J.; Francés, F.; Díez-Herrero, A.; Benito, G.

    2015-01-01

    analysis using documentary data (plus gauged record) improved the estimates of the probabilities of rare floods (return intervals of 100 year and higher). Under non-stationary modelling flood occurrence associated with an exceedance probability of 0.01 (i.e. return period of 100 year) has changed over the last 500 year due to decadal and multi-decadal variability of the NAO. Yet, frequency analysis under stationary models was successful on providing an average discharge around which value flood quantiles estimated by non-stationary models fluctuate through time.

  20. Assimilation of stream discharge for flood forecasting: Updating a semidistributed model with an integrated data assimilation scheme

    NASA Astrophysics Data System (ADS)

    Li, Yuan; Ryu, Dongryeol; Western, Andrew W.; Wang, Q. J.

    2015-05-01

    Real-time discharge observations can be assimilated into flood models to improve forecast accuracy; however, the presence of time lags in the routing process and a lack of methods to quantitatively represent different sources of uncertainties challenge the implementation of data assimilation techniques for operational flood forecasting. To address these issues, an integrated error parameter estimation and lag-aware data assimilation (IEELA) scheme was recently developed for a lumped model. The scheme combines an ensemble-based maximum a posteriori (MAP) error estimation approach with a lag-aware ensemble Kalman smoother (EnKS). In this study, the IEELA scheme is extended to a semidistributed model to provide for more general application in flood forecasting by including spatial and temporal correlations in model uncertainties between subcatchments. The result reveals that using a semidistributed model leads to more accurate forecasts than a lumped model in an open-loop scenario. The IEELA scheme improves the forecast accuracy significantly in both lumped and semidistributed models, and the superiority of the semidistributed model remains in the data assimilation scenario. However, the improvements resulting from IEELA are confined to the outlet of the catchment where the discharge observations are assimilated. Forecasts at "ungauged" internal locations are not improved, and in some instances, even become less accurate.

  1. 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...

  2. 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…

  3. 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...

  4. 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.

  5. Power law time dependence of river flood decay and its relationship to long term discharge frequency distribution. [California

    NASA Technical Reports Server (NTRS)

    Schubert, G.; Lingenfelter, R. E.

    1973-01-01

    Investigations have continued into the possibility that significant information on stream flow rates can be obtained from aerial and satellite imagery of river meander patterns by seeking a correlation between the meander and discharge spectra of rivers. Such a correlation could provide the basis for a simple and inexpensive technique for remote sensing of the water resources of large geographical areas, eliminating the need for much hydrologic recording. The investigation of the nature of the meander and discharge spectra and their interrelationship can also contribute to a more fundamental understanding of the processes of both river meander formation and drainage of large basins. It has been found that floods decay with an inverse power law dependence on time. The exponent of this dependence varies from river to river and even from station to station along the same river. This power law time dependence makes possible the forecasting of river discharge with an uncertainty of about 5% for as long as a month following the flood peak.

  6. Estimating design-flood discharges for streams in Iowa using drainage-basin and channel-geometry characteristics

    USGS Publications Warehouse

    Eash, D.A.

    1993-01-01

    Procedures provided for applying the drainage-basin and channel-geometry regression equations depend on whether the design-flood discharge estimate is for a site on an ungaged stream, an ungaged site on a gaged stream, or a gaged site. When both a drainage-basin and a channel-geometry regression-equation estimate are available for a stream site, a procedure is presented for determining a weighted average of the two flood estimates. The drainage-basin regression equations are applicable to unregulated rural drainage areas less than 1,060 square miles, and the channel-geometry regression equations are applicable to unregulated rural streams in Iowa with stabilized channels.

  7. Flood of June 27, 1975, in City of Ames, Iowa

    USGS Publications Warehouse

    Lara, Oscar G.; Heinitz, Albert J.

    1976-01-01

    The peak discharge at the Squaw Creek station, 206 mi2 (534 km2), was measured at 11,300 ft3/s (320 m3/s), which is 1.6 times the 100-year flood. The south Skunk River above the confluence with Squaw creek, 315 mi2 (816 km2), peaked at 5,330 ft3/s (151 m3). The recurrence interval of this discharge is 6.0 years. The peak discharge on the South Skunk River below the confluence with Squaw creek, 556 mi2 (1440 km2), was 14,700 ft3/s (416 m3/s), which is 1.1 times the 100-year flood.

  8. Floods of December 1982 to May 1983 in the central and southern Mississippi River and the Gulf of Mexico basins

    USGS Publications Warehouse

    Stone, Roy B.; Bingham, Roy H.

    1991-01-01

    Widespread flooding occurred in December 1982 and in spring 1983 in the central and southern Mississippi River basin. The first series of storms, December 2-7, caused severe flooding along many streams in Illinois, Missouri, and Arkansas. Much of the three-State area experienced recordbreaking 24-hour rainfall amounts that caused some streams to exceed previously known flood heights and discharges; in many cases the recurrence interval of peak discharges exceeded 100 years. The second series of storms, December 24-29, caused severe flooding in Louisiana and moderate flooding in Mississippi. Peak discharges on some streams exceeded the 100-year recurrence interval. Damages exceeded $200 million and 25 persons died as a result of the December storms. Western Tennessee was on the fringes of both storms and received only minor flooding. During April 4-8, 1983, as much as 17 inches of rain fell in parts of southern Mississippi and southeastern Louisiana. In some areas, 24-hour amounts exceeded 5 inches, causing peak discharges to exceed the recurrence interval of 100 years at 20 streamflow gaging stations. In May 1983 heavy and intense rains caused major flooding in the Big Black River and Pearl River basins in Mississippi.

  9. The Effects of Urbanization and Flood Control on Sediment Discharge of a Southern California River, Evidence of a Dilution Effect

    NASA Astrophysics Data System (ADS)

    Warrick, J. A.; Orzech, K. M.; Rubin, D. M.

    2004-12-01

    The southern California landscape has undergone dramatic urbanization and population growth during the past 60 years and currently supports almost 20 million inhabitants. During this time, rivers of the region have been altered with damming, channel straightening and hardening, and water transfer engineering. These changes have drastically altered water and sediment discharge from most of the region's drainage basins. Here we focus on changes in sediment discharge from the largest watershed of southern California, the Santa Ana River. Order-of-magnitude drops in the suspended sediment rating curves (the relationship between suspended sediment concentration and instantaneous river discharge) are observed between 1967 and 2001, long after the construction of a major flood control dam in 1941. These sediment concentration decreases do not, however, represent alteration of the total sediment flux from the basin (a common interpretation of sediment rating curves), but rather a dilution of suspended sediment by increases (approx. 4x) in stormwater discharge associated with urbanization. Increases in peak and total stormwater discharge are consistent with runoff patterns from urbanizing landscapes, supporting our hypothesis that the diluting water originated from stormwater runoff generated in urban areas both up- and downstream of dams. Our dilution hypothesis is further supported with water and sediment budgets, dilution calculations, and suspended and bed grain size information.

  10. Numerical study on the performance of bulb turbine by using runaway condition to flood discharge and sediment dredging

    NASA Astrophysics Data System (ADS)

    Yaping, Z.; Weili, L.; Zhihua, L.; Hui, R.; Xingqi, L.

    2014-03-01

    When the floodwater of the bulb tubular type power station is released, a large number of sediment carried by the flood silts up at outlet of the tube, and has a serious impact on the later normal operation of the power station. In order to solve this problem, this paper presents a method that treats the tube sluice as the energy dissipation facility, use the small opening runaway conditions to carry out a regular and short time sediment flush during discharge, and set the sediment self-flushing corridor in the downstream river to achieve sediment flushing and dredging. Unsteady three-dimensional numerical study which considers free-surface of the Reservoir for different tube sluice conditions is conducted to reveal the flow capacity of the turbine and the flow characteristics in the draft tube. In particular, through analyzing the flow characteristics in the tube, the maximum particle size of the sand that can be washed away can be determined, assuming the outlet velocity of the tube is the starting speed, and then the sediment flushing capability of the turbine can also be estimated. The results show that: using the runaway conditions for flood discharge and dropping the height of the tube sluice to achieve the purpose of energy dissipation not only can improve the flood discharge capacity of the power plant, but also can increase flushing distance at the tailrace, and thus enhance the ability to remove silt. Setting the sediment self-flushing corridor at the downstream river would be a good solution to tailrace siltation problems of the bulb turbine.

  11. Flood of June 15, 1981, in Great Bend and vicinity, central Kansas

    USGS Publications Warehouse

    Clement, R.W.; Johnson, D.G.

    1982-01-01

    Torrential precipitation, as much as 20 inches in 12 hours, resulted in unprecedented flooding on Dry Walnut Creek in southwestern Barton County, central Kansas. Runoff from the storm caused extensive flooding in the town of Great Bend on June 15, 1981. Estimates of total damages exceeded $42 million. Measurements of peak discharges made in the downstream part of the Dry Walnut Creek watershed were as much as 3 1/2 times the estimated magnitude of the 100-year flood and in some locations exceeded the maximum previously measured discharge for the area. (USGS)

  12. Factors affecting accuracy of slope-area discharge determination of the September 1992 flood in Raven Fork, Western North Carolina

    USGS Publications Warehouse

    Eddins, W. Harold; Zembrzuski, Thomas J., Jr.

    1994-01-01

    For the flood of September 10, 1992, in Raven Fork, Swain County, North Carolina, a peak discharge of 460 cubic meters per second was computed by using the slope-area method. Accuracy of this determination depends on suitability of the selected reach and, in particular, selection of Manning's roughness coefficients, interpretation of the high-water marks, number and placement of cross sections, presence of large expansions or contractions, state-of-flow transitions, and magnitude of the change in water-surface elevation. Some of these factors can contribute to greater uncertainties for measurements in steep mountain streams than for measurements in streams with flatter gradients.

  13. 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

  14. Flood of October 1986 at Seward, Alaska

    USGS Publications Warehouse

    Jones, S.H.; Zenone, Chester

    1988-01-01

    Broad areas along the lower Resurrection River and Salmon Creek as well as the surfaces of several adjacent alluvial fans in the Seward area were flooded as a result of the intensive rainstorm of October 9-11, 1986. Severe erosion took place through the steep gradient, mountain canyons and near the apex of the fans, while rock and debris were deposited on the distal parts of the fans. In Godwin, Lost, Box Canyon, Japanese, and Spruce Creek basins, and perhaps others, landslides or debris avalanches dammed the streams temporarily. Subsequent failure or overtopping of these dams led to ' surge-release ' flooding; peak discharge of such a flood at Spruce Creek was 13,600 cu ft/sec, four times as great as any previously known maximum discharge from the basin and 2.5 times as great as the runoff rate from the debris dam. Flood discharges were determined indirectly--using the slope-area method--at ten high-gradient reaches on nine streams. Computed peak discharges for several small basins were the largest since records began in 1963. The largest rainfall-runoff rate unaffected by surge-release was 1 ,020 cu ft per sec per sq mi at Rudolph Creek, which has a drainage area of 1.00 sq mi. The 15.05 inches of rain that fell in one 24-hour period during the storm was assigned a recurrence interval of 100 years or greater. The length of the streamflow record available for most Seward area streams-25 years or less-is inadequate to reliably define flood frequency relations for recurrence intervals as great as 100 years. However, the slope-area determined discharge of Spruce Creek above the debris avalanche indicates a recurrence interval of a 100 years or greater. In addition, conventional flood-frequency analysis techniques are not applicable to peak discharges that are affected by surge-release phenomena. Large, damaging floods have repeatedly caused major damage in the Seward area, and the potential for catastrophic, debris-laden floods is an ever-present threat to areas

  15. 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

  16. Flood of August 4-5, 1943, in central West Virginia, with a summary of flood stages and discharges in West Virginia

    USGS Publications Warehouse

    Erskine, Harlan Mercer

    1951-01-01

    During the night of August 4-5, 1943, a violent thunderstorm of unusual intensity occurred in parts of Braxton, Calhoun, Gilmer, Ritchie, and Wirth Counties in the Little Kanawha River Basin in central West Virginia. Precipitation amounted to as much as 15 inches in 2 hours in some sections. As a result, many small streams and a reach of the Little Kanawha River in the vicinity of Burnsville and Gilmer reached the highest stages known. Computations based on special surveys made at suitable sites on representative small streams in the areas of intense flooding indicate that peak discharges closely approach 50 percent of the Jarvis scale. Twenty-three lives were lost on the small tributaries as numerous homes were swept away by the flood, which developed with incredible rapidity during the early morning hours. Damage estimated at $1,300,000 resulted to farm buildings, crops, land, livestock, railroads, highways, and gas- and oil-producing facilities. Considerable permanent land damage resulted from erosion and deposition of sand and gravel.

  17. Increasing risk of great floods in a changing climate

    USGS Publications Warehouse

    Milly, P.C.D.; Wetherald, R.T.; Dunne, K.A.; Delworth, T.L.

    2002-01-01

    Radiative effects of anthropogenic changes in atmospheric composition are expected to cause climate changes, in particular an intensification of the global water cycle with a consequent increase in flood risk. But the detection of anthropogenically forced changes in flooding is difficult because of the substantial natural variability; the dependence of streamflow trends on flow regime further complicates the issue. Here we investigate the changes in risk of great floods - that is, floods with discharges exceeding 100-year levels from basins larger than 200,000 km2 - using both streamflow measurements and numerical simulations of the anthropogenic climate change associated with greenhouse gases and direct radiative effects of sulphate aerosols. We find that the frequency of great floods increased substantially during the twentieth century. The recent emergence of a statistically significant positive trend in risk of great floods is consistent with results from the climate model, and the model suggests that the trend will continue.

  18. 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)

  19. Floods in Central Texas, December 1991

    USGS Publications Warehouse

    Hejl, H.R., Jr.; Slade, Raymond M.; Jennings, Marshall E.

    1996-01-01

    Record-breaking peak discharges were recorded at eight U.S. Geological Survey (USGS) streamflow-gaging stations in central Texas during December 1991 (fig. 1), and substantial peak discharges also occurred at numerous other stations. Large peak discharges during December are unusual in central Texas. The rainfall causing the flooding began on December 18, with 6-day totals exceeding 10 inches (in.) in the area of heaviest rainfall.This report documents peak discharges and runoff volumes during December 1991. Recurrence intervals were determined for the peak discharges and runoff volumes for 1-, 3-, and 7-day periods. A recurrence interval references the approximate number of years during which a given peak discharge or runoff volumes is expected to be equaled or exceeded only once. A flood of a given recurrence interval is defined on the basis of peak discharge – for example, a 100-year flood is defined as the peak discharge that has a 1-percent chance of being equaled or exceeded in any given year.

  20. Floods of July 12, 1972, March 19, 1979, and June 15, 1991, in the Turkey River Basin, northeast Iowa

    USGS Publications Warehouse

    Eash, D.A.; Koppensteiner, B.A.

    1996-01-01

    Water-surface-elevation profiles and peak discharges for the floods of July 12, 1972, March 19, 1979, and June 15, 1991, in the Turkey River Basin, northeast Iowa, are presented in this report. The profiles illustrate the 1979 and 1991 floods along the Turkey River in Fayette and Clayton Counties and along the Volga River in Clayton County; the 1991 flood along Roberts Creek in Clayton County and along Otter Creek in Fayette County; and the 1972 flood along the Turkey River in Winneshiek and Fayette Counties. Watersurface elevations for the flood of March 19,1979, were collected by the Iowa Natural Resources Council. The June 15, 1991, flood on the Turkey River at Garber (station number 05412500) is the largest known flood-peak discharge at the streamflow-gaging station for the period 1902-95. The peak discharge for June 15, 1991, of 49,900 cubic feet per second was 1.4 times larger than the 100-year recurrence-interval discharge. The report provides information on flood stages and discharges and floodflow frequencies for streamflow-gaging stations in the Turkey River Basin using flood information collected during 1902-95. Information on temporary bench marks and reference points established in the Turkey River Basin during 1981, 1992, and 1996 also is included in the report. A flood history describes rainfall conditions for floods that occurred during 1922, 1947, 1972, 1979, and 1991.

  1. 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

  2. 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

  3. 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.

  4. Correcting acoustic Doppler current profiler discharge measurement bias from moving-bed conditions without global positioning during the 2004 Glen Canyon Dam controlled flood on the Colorado River

    USGS Publications Warehouse

    Gartner, J.W.; Ganju, N.K.

    2007-01-01

    Discharge measurements were made by acoustic Doppler current profiler at two locations on the Colorado River during the 2004 controlled flood from Glen Canyon Dam, Arizona. Measurement hardware and software have constantly improved from the 1980s such that discharge measurements by acoustic profiling instruments are now routinely made over a wide range of hydrologic conditions. However, measurements made with instruments deployed from moving boats require reliable boat velocity data for accurate measurements of discharge. This is normally accomplished by using special acoustic bottom track pings that sense instrument motion over bottom. While this method is suitable for most conditions, high current flows that produce downstream bed sediment movement create a condition known as moving bed that will bias velocities and discharge to lower than actual values. When this situation exists, one solution is to determine boat velocity with satellite positioning information. Another solution is to use a lower frequency instrument. Discharge measurements made during the 2004 Glen Canyon controlled flood were subject to moving-bed conditions and frequent loss of bottom track. Due to site conditions and equipment availability, the measurements were conducted without benefit of external positioning information or lower frequency instruments. This paper documents and evaluates several techniques used to correct the resulting underestimated discharge measurements. One technique produces discharge values in good agreement with estimates from numerical model and measured hydrographs during the flood. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

  5. Estimation of flood discharges at selected annual exceedance probabilities for unregulated, rural streams in Vermont, with a section on Vermont regional skew regression

    USGS Publications Warehouse

    Olson, Scott A.; with a section by Veilleux, Andrea G.

    2014-01-01

    This report provides estimates of flood discharges at selected annual exceedance probabilities (AEPs) for streamgages in and adjacent to Vermont and equations for estimating flood discharges at AEPs of 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent (recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-years, respectively) for ungaged, unregulated, rural streams in Vermont. The equations were developed using generalized least-squares regression. Flood-frequency and drainage-basin characteristics from 145 streamgages were used in developing the equations. The drainage-basin characteristics used as explanatory variables in the regression equations include drainage area, percentage of wetland area, and the basin-wide mean of the average annual precipitation. The average standard errors of prediction for estimating the flood discharges at the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent AEP with these equations are 34.9, 36.0, 38.7, 42.4, 44.9, 47.3, 50.7, and 55.1 percent, respectively. Flood discharges at selected AEPs for streamgages were computed by using the Expected Moments Algorithm. To improve estimates of the flood discharges for given exceedance probabilities at streamgages in Vermont, a new generalized skew coefficient was developed. The new generalized skew for the region is a constant, 0.44. The mean square error of the generalized skew coefficient is 0.078. This report describes a technique for using results from the regression equations to adjust an AEP discharge computed from a streamgage record. This report also describes a technique for using a drainage-area adjustment to estimate flood discharge at a selected AEP for an ungaged site upstream or downstream from a streamgage. The final regression equations and the flood-discharge frequency data used in this study will be available in StreamStats. StreamStats is a World Wide Web application providing automated regression-equation solutions for user-selected sites on streams.

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

    SciTech Connect

    Einziger, R. E.

    1998-12-16

    Because of delays in closing the back end of the fuel cycle in the U.S., there is a need to extend dry inert storage of spent fuel beyond its originally anticipated 20-year duration. Many of the methodologies developed to support initial licensing for 20-year storage should be able to support the longer storage periods envisioned. This paper evaluates the applicability of existing information and methodologies to support dry storage up to 100 years. The thrust of the analysis is the potential behavior of the spent fuel. In the USA, the criteria for dry storage of LWR spent fuel are delineated in 10 CFR 72 [1]. The criteria fall into four general categories: maintain subcriticality, prevent the release of radioactive material above acceptable limits, ensure that radiation rates and doses do not exceed acceptable levels, and maintain retrievability of the stored radioactive material. These criteria need to be considered for normal, off-normal, and postulated accident conditions. The initial safety analysis report submitted for licensing evaluated the fuel's ability to meet the requirements for 20 years. It is not the intent to repeat these calculations, but to look at expected behavior over the additional 80 years, during which the temperatures and radiation fields are lower. During the first 20 years, the properties of the components may change because of elevated temperatures, presence of moisture, effects of radiation, etc. During normal storage in an inert atmosphere, there is potential for the cladding mechanical properties to change due to annealing or interaction with cask materials. The emissivity of the cladding could also change due to storage conditions. If there is air leakage into the cask, additional degradation could occur through oxidation in breached rods, which could lead to additional fission gas release and enlargement of cladding breaches. Air in-leakage could also affect cover gas conductivity, cladding oxidation, emissivity changes, and

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Delineation of flooding within the upper Mississippi River Basin, 1993-flood of June 29-September 18, 1993, in Iowa City and vicinity, Iowa

    USGS Publications Warehouse

    Schaap, Bryan D.; Harvey, Craig A.

    1995-01-01

    The hydrologic investigations atlas shows the areas in and around Iowa City, Iowa, that were flooded by the Iowa River in 1993. This map also depicts the Federal Emergency Management Agency (FEMA) 100-year flood boundaries. The drainage basin of the Iowa River at Iowa City received well over 100 percent of normal rainfall in June, July, and August, 1993. At the Cedar Rapids airport, located about 20 miles north-northwest of Iowa City, July rainfall was 414 percent of normal. The discharges at U.S. Geological Survey streamflow-gaging stations on the Iowa River upstream of Coralville Reservoir, just downstream from Coralville Reservoir, and at Iowa City are shown. A profile of the maximum water-surface elevations of the 1993 flood in Iowa City and vicinity is higher than the FEMA 100-year flood profile. The water-surface elevation of Coralville Reservoir is shown from June 29-September 18, 1993.

  12. Flood of July 5-7, 1978, on the South Fork Zumbro River at Rochester, Minnesota

    USGS Publications Warehouse

    Latkovich, V.J.

    1979-01-01

    The intense thunderstorm of July 5-6, 1978, caused record flooding on the South Fork Zumbro River at Rochester, Minnesota. The peak discharge on July 6 was 30,500 cubic feet per second compared with 19,600 cubic feet per second for the flood of March 1965, which was the largest previously known. The 1965 flood had a recurrence interval of about 30 years, whereas the 1978 flood had a recurrence interval exceeding 100 years. The flood waters claimed at least 5 lives and 5,000 people were forced to leave their homes. Millions of dollars in flood damage was reported, and this report summarizes some of the flood data and a photomosaic map shows the inundated area.

  13. Generalized flood-frequency estimates for urban areas in Missouri

    USGS Publications Warehouse

    Gann, Ector Eugene

    1971-01-01

    A method is presented for estimating flood-frequency information for urban areas in Missouri. Flood-frequency relations are presented which provide an estimate of the flood-peak discharge for floods with recurrence intervals from 2.33 to 100 years for basins with various degrees of existing or projected urban development. Drainage area sizes for which the relations are applicable range from 0.1 to 50 square miles. These generalized relations will be useful to the urban planner and designer until more comprehensive studies are completed for the individual urban areas within the State. The relations will also be of use in the definition of flood-hazard areas in Missouri.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Constraining frequency-magnitude-area relationships for precipitation and flood discharges using radar-derived precipitation estimates: example applications in the Upper and Lower Colorado River Basins, USA

    NASA Astrophysics Data System (ADS)

    Orem, C. A.; Pelletier, J. D.

    2015-11-01

    Flood-envelope curves (FEC) are useful for constraining the upper limit of possible flood discharges within drainage basins in a particular hydroclimatic region. Their usefulness, however, is limited by their lack of a well-defined recurrence interval. In this study we use radar-derived precipitation estimates to develop an alternative to the FEC method, i.e. the frequency-magnitude-area-curve (FMAC) method, that incorporates recurrence intervals. The FMAC method is demonstrated in two well-studied U.S. drainage basins, i.e. the Upper and Lower Colorado River basins (UCRB and LCRB, respectively), using Stage III Next-Generation-Radar (NEXRAD) gridded products and the diffusion-wave flow-routing algorithm. The FMAC method can be applied worldwide using any radar-derived precipitation estimates. In the FMAC method, idealized basins of similar contributing area are grouped together for frequency-magnitude analysis of precipitation intensity. These data are then routed through the idealized drainage basins of different contributing areas, using contributing-area-specific estimates for channel slope and channel width. Our results show that FMACs of precipitation discharge are power-law functions of contributing area with an average exponent of 0.79 ± 0.07 for recurrence intervals from 10 to 500 years. We compare our FMACs to published FECs and find that for wet antecedent-moisture conditions, the 500-year FMAC of flood discharge in the UCRB is on par with the US FEC for contributing areas of ~ 102 to 103 km2. FMACs of flood discharge for the LCRB exceed the published FEC for the LCRB for contributing areas in the range of ~ 102 to 104 km2. The FMAC method retains the power of the FEC method for constraining flood hazards in basins that are ungauged or have short flood records, yet it has the added advantage that it includes recurrence interval information necessary for estimating event probabilities.

  19. Verification of 1921 peak discharge at Skagit River near Concrete, Washington, using 2003 peak-discharge data

    USGS Publications Warehouse

    Mastin, M.C.; Kresch, D.L.

    2005-01-01

    The 1921 peak discharge at Skagit River near Concrete, Washington (U.S. Geological Survey streamflow-gaging station 12194000), was verified using peak-discharge data from the flood of October 21, 2003, the largest flood since 1921. This peak discharge is critical to determining other high discharges at the gaging station and to reliably estimating the 100-year flood, the primary design flood being used in a current flood study of the Skagit River basin. The four largest annual peak discharges of record (1897, 1909, 1917, and 1921) were used to determine the 100-year flood discharge at Skagit River near Concrete. The peak discharge on December 13, 1921, was determined by James E. Stewart of the U.S. Geological Survey using a slope-area measurement and a contracted-opening measurement. An extended stage-discharge rating curve based on the 1921 peak discharge was used to determine the peak discharges of the three other large floods. Any inaccuracy in the 1921 peak discharge also would affect the accuracies of the three other largest peak discharges. The peak discharge of the 1921 flood was recalculated using the cross sections and high-water marks surveyed after the 1921 flood in conjunction with a new estimate of the channel roughness coefficient (n value) based on an n-verification analysis of the peak discharge of the October 21, 2003, flood. The n value used by Stewart for his slope-area measurement of the 1921 flood was 0.033, and the corresponding calculated peak discharge was 240,000 cubic feet per second (ft3/s). Determination of a single definitive water-surface profile for use in the n-verification analysis was precluded because of considerable variation in elevations of surveyed high-water marks from the flood on October 21, 2003. Therefore, n values were determined for two separate water-surface profiles thought to bracket a plausible range of water-surface slopes defined by high-water marks. The n value determined using the flattest plausible slope was 0

  20. Flood frequency and storm runoff of urban areas of Memphis and Shelby County, Tennessee

    USGS Publications Warehouse

    Neely, B.L.

    1984-01-01

    Techniques are presented for estimating the magnitude and frequency of peak discharges and storm runoff on stream in urban areas of Memphis, Tennessee. Comprehensive analyses were made in which physical characteristics of streams are related to snythetic flood characteristics at gaging stations. Equations derived from analyses provide estimates of peak discharges with recurrence intervals of 2 to 100 years on streams that have drainage areas less than 20 square miles. The regression analyses indicated that size of drainage area and condition of channel (paved or unpaved) are the most significant basin characteristics affecting the magnitude and frequency of floods in urban streams. Data from 27 gaging stations with 8 years of record were used in the analyses. Flood frequency at each gaging station was computed from calibrated parameters in a rainfall-runoff model. Techniques are also presented for estimating discharge hydrographs for individual floods by using the unit hydrograph, lag time, and rainfall excess. (USGS)

  1. Flood-plain delineation for Horsepen Run, Sugarland Run, Nichols Run, Pond Branch, Clarks Branch, and Mine Run Branch basins, Fairfax County, Virginia

    USGS Publications Warehouse

    Soule, Pat LeRoy

    1978-01-01

    Water-surface profiles of the 25-, 50-, and 100-year recurrence interval discharges have been computed for all streams and reaches of channels in Fairfax County, Virginia, having a drainage area greater than 1 square mile except for Dogue Creek, Little Hunting Creek, and that portion of Cameron Run above Lake Barcroft. Maps have a 2-foot contour interval and a horizontal scale of 1 inch equals 100 feet were used for base on which flood boundaries were delineated for 25-, 50-, and 100-year floods to be expected in each basin under ultimate development conditions. This report is one of a series and presents a discussion of techniques employed in computing discharges and profiles as well as the flood profiles and maps on which flood boundaries have been delineated for the Horsepen Run, Sugarland Run, Nichols Run, and Pond Branch basins in Fairfax County. (Woodard-USGS)

  2. Flood-plain delineation for Occoquan River, Wolf Run, Sandy Run, Elk Horn Run, Giles Run, Kanes Creek, Racoon Creek, and Thompson Creek, Fairfax County, Virginia

    USGS Publications Warehouse

    Soule, Pat LeRoy

    1978-01-01

    Water-surface profiles of the 25-, 50-, and 100-year recurrence interval discharges have been computed for all streams and reaches of channels in Fairfax County, Virginia, having a drainage area greater than 1 square mile except for Dogue Creek, Little Hunting Creek, and that portion of Cameron Run above Lake Barcroft. Maps having a 2-foot contour interval and a horizontal scale of 1 inch equals 100 feet were used for base on which flood boundaries were delineated for 25-, 50-, and 100-year floods to be expected in each basin under ultimate development conditions. This report is one of a series and presents a discussion of techniques employed in computing discharges and profiles as well as the flood profiles and maps on which flood boundaries have been delineated for the Occoquan River and its tributaries within Fairfax County and those streams on Mason Neck within Fairfax County tributary to the Potomac River. (Woodard-USGS)

  3. Estimates of peak flood discharge for 21 sites in the Front Range in Colorado in response to extreme rainfall in September 2013

    USGS Publications Warehouse

    Moody, John A.

    2016-01-01

    Extreme rainfall in September 2013 caused destructive floods in part of the Front Range in Boulder County, Colorado. Erosion from these floods cut roads and isolated mountain communities for several weeks, and large volumes of eroded sediment were deposited downstream, which caused further damage of property and infrastructures. Estimates of peak discharge for these floods and the associated rainfall characteristics will aid land and emergency managers in the future. Several methods (an ensemble) were used to estimate peak discharge at 21 measurement sites, and the ensemble average and standard deviation provided a final estimate of peak discharge and its uncertainty. Because of the substantial erosion and deposition of sediment, an additional estimate of peak discharge was made based on the flow resistance caused by sediment transport effects.Although the synoptic-scale rainfall was extreme (annual exceedance probability greater than 1,000 years, about 450 millimeters in 7 days) for these mountains, the resulting peak discharges were not. Ensemble average peak discharges per unit drainage area (unit peak discharge, [Qu]) for the floods were 1–2 orders of magnitude less than those for the maximum worldwide floods with similar drainage areas and had a wide range of values (0.21–16.2 cubic meters per second per square kilometer [m3 s-1 km-2]). One possible explanation for these differences was that the band of high-accumulation, high-intensity rainfall was narrow (about 50 kilometers wide), oriented nearly perpendicular to the predominant drainage pattern of the mountains, and therefore entire drainage areas were not subjected to the same range of extreme rainfall. A linear relation (coefficient of determination [R2]=0.69) between Qu and the rainfall intensity (ITc, computed for a time interval equal to the time-of-concentration for the drainage area upstream from each site), had the form: Qu=0.26(ITc-8.6), where the coefficient 0.26 can be considered to be an

  4. A physically-based method for predicting peak discharge of floods caused by failure of natural and constructed earthen dams

    USGS Publications Warehouse

    Walder, J.S.; O'Connor, J. E.; Costa, J.E.

    1997-01-01

    We analyse a simple, physically-based model of breach formation in natural and constructed earthen dams to elucidate the principal factors controlling the flood hydrograph at the breach. Formation of the breach, which is assumed trapezoidal in cross-section, is parameterized by the mean rate of downcutting, k, the value of which is constrained by observations. A dimensionless formulation of the model leads to the prediction that the breach hydrograph depends upon lake shape, the ratio r of breach width to depth, the side slope ?? of the breach, and the parameter ?? = (V.D3)(k/???gD), where V = lake volume, D = lake depth, and g is the acceleration due to gravity. Calculations show that peak discharge Qp depends weakly on lake shape r and ??, but strongly on ??, which is the product of a dimensionless lake volume and a dimensionless erosion rate. Qp(??) takes asymptotically distinct forms depending on whether < ??? 1 or < ??? 1. Theoretical predictions agree well with data from dam failures for which k could be reasonably estimated. The analysis provides a rapid and in many cases graphical way to estimate plausible values of Qp at the breach.We analyze a simple, physically-based model of breach formation in natural and constructed earthen dams to elucidate the principal factors controlling the flood hydrograph at the breach. Formation of the breach, which is assumed trapezoidal in cross-section, is parameterized by the mean rate of downcutting, k, the value of which is constrained by observations. A dimensionless formulation of the model leads to the prediction that the breach hydrograph depends upon lake shape, the ratio r of breach width to depth, the side slope ?? of the breach, and the parameter ?? = (V/D3)(k/???gD), where V = lake volume, D = lake depth, and g is the acceleration due to gravity. Calculations show that peak discharge Qp depends weakly on lake shape r and ??, but strongly on ??, which is the product of a dimensionless lake volume and a

  5. Estimation of the possible flood discharge and volume of stormwater for designing water storage.

    PubMed

    Kirzhner, Felix; Kadmon, Avri

    2011-01-01

    The shortage of good-quality water resources is an important issue in arid and semiarid zones. Stormwater-harvesting systems that are capable of delivering good-quality wastewater for non-potable uses while taking into account environmental and health requirements must be developed. For this reason, the availability of water resources of marginal quality, like stormwater, can be a significant contribution to the water supply. Current stormwater management practices in the world require the creation of control systems that monitor quality and quantity of the water and the development of stormwater basins to store increased runoff volumes. Public health and safety considerations should be considered. Urban and suburban development, with the creation of buildings and roads and innumerable related activities, turns rain and snow into unwitting agents of damage to our nation's waterways. This urban and suburban runoff, legally known as stormwater, is one of the most significant sources of water pollution in the world. Based on various factors like water quality, runoff flow rate and speed, and the topography involved, stormwater can be directed into basins, purification plants, or to the sea. Accurate floodplain maps are the key to better floodplain management. The aim of this work is to use geographic information systems (GIS) to monitor and control the effect of stormwater. The graphic and mapping capabilities of GIS provide strong tools for conveying information and forecasts of different storm-water flow and buildup scenarios. Analyses of hydrologic processes, rainfall simulations, and spatial patterns of water resources were performed with GIS, which means, based on integrated data set, the flow of the water was introduced into the GIS. Two cases in Israel were analyzed--the Hula Project (the Jordan River floods over the peat soil area) and the Kishon River floodplains as it existed in the Yizrael Valley. PMID:22435327

  6. Magnitude and frequency of 1993 flood volumes in Upper Mississippi River Basin

    USGS Publications Warehouse

    Southard, Rodney E.

    1995-01-01

    Previous maximum flows on many streams and rivers were exceeded during the flood of 1993 in the upper Mississippi River Basin. Not only were peak discharges exceeded at many streamflow-gaging stations, but also flood volumes were significantly higher than previous maximums. Rainfall amounts that were greater than 127 cm (50 in.) were recorded in parts of Kansas, Missouri, and Iowa from April 1 through September 30, 1993. As a result of the excessive rainfall, 53 of the 60 stations discussed had flow volumes greater than twice the mean flow volume for April through September. The Mississippi River at St. Louis, Missouri, remained above flood stage for 144 days from April 1 to September 30, 1993, compared with 81 days during the spring and summer flood of 1973. Of the 60 stations, 24 recorded new maximum 3-day flood volumes, and 47 recorded new maximum 120-day flood volumes. This indicates that the flooding of 1993 is significant with respect to its long duration and magnitude of flow. The same aspect is indicated in the frequency analysis of the 1993 flood. During the 1993 flood, the 100-year 3-day flows were exceeded at 22 stations, and the 100-year 120-day flows were exceeded at 43 stations.

  7. Annual peak discharges from small drainage areas in Montana through September 1976

    USGS Publications Warehouse

    Johnson, M.V.; Omang, R.J.; Hull, J.A.

    1977-01-01

    Annual peak discharge from small drainage areas is tabulated for 336 sites in Montana. The 1976 additions included data collected at 206 sites. The program which investigates the magnitude and frequency of floods from small drainage areas in Montana, was begun July 1, 1955. Originally 45 crest-stage gaging stations were established. The purpose of the program is to collect sufficient peak-flow data, which through analysis could provide methods for estimating the magnitude and frequency of floods at any point in Montana. The ultimate objective is to provide methods for estimating the 100-year flood with the reliability needed for road design. (Woodard-USGS)

  8. Measuring flood discharge in unstable stream channels using ground-penetrating radar

    USGS Publications Warehouse

    Spicer, K.R.; Costa, J.E.; Placzek, G.

    1997-01-01

    Field experiments were conducted to test the ability of ground-penetrating radar (GPR) to measure stream-channel cross sections at high flows without the necessity of placing instruments in the water. Experiments were conducted at four U.S. Geological Survey gaging stations in southwest Washington State. With the GPR antenna suspended above the water surface from a bridge or cableway, traverses were made across stream channels to collect radar profile plots of the streambed. Subsequent measurements of water depth were made using conventional depth-measuring equipment (weight and tape) and were used to calculate radar signal velocities. Other streamflow-parameter data were collected to examine their relation to radar signal velocity and to claritv of streambed definition. These initial tests indicate that GPR is capable of producing a reasonably accurate (??20%) stream-channel profile and discharge far more quickly than conventional stream-gaging procedures, while avoiding the problems and hazards associated with placing instruments in the water.

  9. A physically-based method for predicting peak discharge of floods caused by failure of natural and constructed earthen dams

    USGS Publications Warehouse

    Walder, J.S.

    1997-01-01

    We analyse a simple, physically-based model of breach formation in natural and constructed earthen dams to elucidate the principal factors controlling the flood hydrograph at the breach. Formation of the breach, which is assumed trapezoidal in cross-section, is parameterized by the mean rate of downcutting, k, the value of which is constrained by observations. A dimensionless formulation of the model leads to the prediction that the breach hydrograph depends upon lake shape, the ratio r of breach width to depth, the side slope ?? of the breach, and the parameter ?? = (V/ D3)(k/???gD), where V = lake volume, D = lake depth, and g is the acceleration due to gravity. Calculations show that peak discharge Qp depends weakly on lake shape r and ??, but strongly on ??, which is the product of a dimensionless lake volume and a dimensionless erosion rate. Qp(??) takes asymptotically distinct forms depending on whether ?? > 1. Theoretical predictions agree well with data from dam failures for which k could be reasonably estimated. The analysis provides a rapid and in many cases graphical way to estimate plausible values of Qp at the breach.

  10. Reduction of the uncertainties in the water level-discharge relation of a 1D hydraulic model in the context of operational flood forecasting

    NASA Astrophysics Data System (ADS)

    Habert, J.; Ricci, S.; Le Pape, E.; Thual, O.; Piacentini, A.; Goutal, N.; Jonville, G.; Rochoux, M.

    2016-01-01

    This paper presents a data-driven hydrodynamic simulator based on the 1-D hydraulic solver dedicated to flood forecasting with lead time of an hour up to 24 h. The goal of the study is to reduce uncertainties in the hydraulic model and thus provide more reliable simulations and forecasts in real time for operational use by the national hydrometeorological flood forecasting center in France. Previous studies have shown that sequential assimilation of water level or discharge data allows to adjust the inflows to the hydraulic network resulting in a significant improvement of the discharge while leaving the water level state imperfect. Two strategies are proposed here to improve the water level-discharge relation in the model. At first, a modeling strategy consists in improving the description of the river bed geometry using topographic and bathymetric measurements. Secondly, an inverse modeling strategy proposes to locally correct friction coefficients in the river bed and the flood plain through the assimilation of in situ water level measurements. This approach is based on an Extended Kalman filter algorithm that sequentially assimilates data to infer the upstream and lateral inflows at first and then the friction coefficients. It provides a time varying correction of the hydrological boundary conditions and hydraulic parameters. The merits of both strategies are demonstrated on the Marne catchment in France for eight validation flood events and the January 2004 flood event is used as an illustrative example throughout the paper. The Nash-Sutcliffe criterion for water level is improved from 0.135 to 0.832 for a 12-h forecast lead time with the data assimilation strategy. These developments have been implemented at the SAMA SPC (local flood forecasting service in the Haute-Marne French department) and used for operational forecast since 2013. They were shown to provide an efficient tool for evaluating flood risk and to improve the flood early warning system

  11. Flood potential of Topopah Wash and tributaries, eastern part of Jackass Flats, Nevada Test Site, southern Nevada

    USGS Publications Warehouse

    Christensen, Rulon C.; Spahr, Norman E.

    1980-01-01

    Guidelines for the evaluation of potential surface facilities for the storage of high-level radioactive wastes on the Nevada Test Site in southern Nevada include the consideration of the potential for flooding. Those floods that are considered to constitute the principal flood hazards for these facilities are the 100- and 500-year floods, and the maximum potential flood. Flood-prone areas for the three floods with present natural-channel conditions were defined for the eastern part of Jackass Flats in the southwestern part of the Nevada Test Site. The 100-year flood-prone areas would closely parallel most stream channels with very few occurrences of overland flooding between adjacent channels. The 500-year flood and the maximum potential flood would exceed the discharge capacities of main channels and cause overland flooding between adjacent channels throughout most of the study area. Excluded areas would be those located immediately east of the upstream reach of Topopah Wash and between upstream channel reaches of some tributaries. Floodflow characteristics for the three floods were determined at 47 cross sections. The magnitudes of the estimated velocities indicate severe erosion of channels and flood plains would occur in parts of the study area. (USGS)

  12. 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.

  13. Flood of June 14-15, 1990, in Belmont, Jefferson, and Harrison counties, Ohio, with emphasis on Pipe and Wegee Creek basins near Shadyside

    USGS Publications Warehouse

    Shindel, H.L.

    1991-01-01

    A series of violent thunderstorms caused severe floods and consequent damage in the central part of Ohio during June 14-15, 1990. The eastern part of the State, particularly Belmont, Harrison, and Jefferson Counties, sustained the most damage. In the Pipe and Wegee Creek basins near Shadyside, Belmont County, at least 24 people died and property damage exceeded $10 million. An indirect measurement of discharge on Pipe Creek made near the mouth, indicates a peak discharge of 15,000 ft? /s (cubic feet per second) for the drainage area of 11.3 mi? (square miles) and a unit discharge of 1,330 (ft? /s)/mi? (cubic feet per second per square mile). The recurrence interval for this peak discharge is greater than 100 years. An indirect measurement of discharge of Wegee Creek, made 3 miles upstream from the mouth, indicates a peak discharge of 2,200 (ft? /s) /mi? . The recurrence interval for this peak discharge also is greater than 100 years. Longitudal water-surface profiles showed depths ranging from 7 ft. to 22 ft. The severity of flooding was highly variable. For example, the recurrence interval of the peak discharge at one U.S. Geological Survey streamflow-gaging station was only 2 years, whereas the recurrence interval for the peak discharge was greater than 100 years at another gaging station about 22 miles away.

  14. Flood of August 27-28, 1977, West Cache Creek and Blue Beaver Creek, southwestern Oklahoma

    USGS Publications Warehouse

    Corley, Robert K.; Huntzinger, Thomas L.

    1979-01-01

    This report documents a major storm which occurred August 27-28, 1977, in southwest Oklahoma near the communities of Cache and Faxon, OK. Blue Beaver Creek and West Cache Creek and their tributaries experienced extensive flooding that caused an estimated $1 million in damages. Reported rainfall amounts of 8 to 12 inches in 6 hours indicate the storm had a frequency in excess of the 100-year rainfall. Peak discharges on Blue Beaver Creek near Cache and West Cache Creek near Faxon were 13,500 cubic feet per second and 45,700 cubic feet per second respectively. The estimated flood frequency was in excess of 100 years on Blue Beaver Creek and in excess of 50 years on West Cache Creek. Unit runoff on small basins were in excess of 2000 cubic feet per second per square mile. Surveyed highwater marks were used to map the flooded area. (USGS)

  15. 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

  16. 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

  17. Towards real-time flood forecasting in hydraulics: merits of in situ discharge and water level data assimilation for the modeling of the Marne catchment in France

    NASA Astrophysics Data System (ADS)

    Ricci, S. M.; Habert, J.; Le Pape, E.; Piacentini, A.; Jonville, G.; Thual, O.; Zaoui, F.

    2011-12-01

    The present study describes the assimilation of river flow and water level observations and the resulting improvement in flood forecasting. The Kalman Filter algorithm was built on top of the one-dimensional hydraulic model, MASCARET, [1] which describes the Saint-Venant equations. The assimilation algorithm folds in two steps: the first one was based on the assumption that the upstream flow can be adjusted using a three-parameter correction; the second one consisted of directly correcting the hydraulic state. This procedure was previously applied on the Adour Maritime Catchment using water level observations [2]. On average, it was shown that the data assimilation procedure enables an improvement of 80% in the simulated water level over the reanalysis period, 60 % in the forecast water level at a one-hour lead time, and 25% at a twelve-hour lead time. The procedure was then applied on the Marne Catchment, which includes karstic tributaries, located East of the Paris basin, characterized by long flooding periods and strong sensitivity to local precipitations. The objective was to geographically extend and improve the existing model used by the flood forecasting service located in Chalons-en-Champagne. A hydrological study first enabled the specification of boundary conditions (upstream flow or lateral inflow), then the hydraulic model was calibrated using in situ discharge data (adjustment of Strickler coefficients or cross sectional geometry). The assimilation of water level data enabled the reduction of the uncertainty in the hydrological boundary conditions and led to significant improvement of the simulated water level in re-analysis and forecast modes. Still, because of errors in the Strickler coefficients or cross section geometry, the improvement of the simulated water level sometimes resulted in a degradation of discharge values. This problem was overcome by controlling the correction of the hydrological boundary conditions by directly assimilating

  18. Flood of April 1977 in the Appalachian region of Kentucky, Tennessee, Virginia, and West Virginia

    USGS Publications Warehouse

    Runner, Gerald S.; Chin, Edwin H.

    1980-01-01

    Heavy rains fell over the Appalachian region of Kentucky, Tennessee, Virginia and West Virginia April 2-5, 1977, causing record flooding. Rainfall amounts of 4 to 15.5 inches were observed. The maximum amount of 15.5 inches occurred at Jolo, WV , in about 30 hours. This was more than twice the amount which would be expected for a 100-year recurrence-interval storm. Flood discharges along the upper Guyandotte River; Tug Fork and Levisa Fork in the Big Sandy River basin; Cumberland River; and Clinch River and Dowell River in the Tennessee River basin exceeded those previously known. Severe flooding also occurred along the Holston River and along the North Fork Kentucky River. Recurrence intervals of observed flood discharges were greater than 100-years at 29 streamflow measurement sites. Substantial reductions in peak stages and discharges on Levisa Fork, North Pound River, and Guyandotte River, attained as a result of reservoir storage, were reported by U.S. Army Corps of Engineers. Maximum daily suspended-sediment discharges on Guyandotte River near Baileysville, WV, and Tug Fork at Glenhayes, WV, were 54,800 tons/day and 290,000 tons/day, respectively, April 5, 1977. Twenty-two lives were lost and total property damage reportedly exceeded $400 million in the four-State area. (USGS)

  19. Prediction of a Flash Flood in Complex Terrain. Part II: A Comparison of Flood Discharge Simulations Using Rainfall Input from Radar, a Dynamic Model, and an Automated Algorithmic System.

    NASA Astrophysics Data System (ADS)

    Yates, David N.; Warner, Thomas T.; Leavesley, George H.

    2000-06-01

    Three techniques were employed for the estimation and prediction of precipitation from a thunderstorm that produced a flash flood in the Buffalo Creek watershed located in the mountainous Front Range near Denver, Colorado, on 12 July 1996. The techniques included 1) quantitative precipitation estimation using the National Weather Service's Weather Surveillance Radar-1988 Doppler and the National Center for Atmospheric Research's S-band, dual-polarization radars, 2) quantitative precipitation forecasting utilizing a dynamic model, and 3) quantitative precipitation forecasting using an automated algorithmic system for tracking thunderstorms. Rainfall data provided by these various techniques at short timescales (6 min) and at fine spatial resolutions (150 m to 2 km) served as input to a distributed-parameter hydrologic model for analysis of the flash flood. The quantitative precipitation estimates from the weather radar demonstrated their ability to aid in simulating a watershed's response to precipitation forcing from small-scale, convective weather in complex terrain. That is, with the radar-based quantitative precipitation estimates employed as input, the simulated peak discharge was similar to that estimated. The dynamic model showed the most promise in providing a significant forecast lead time for this flash-flood event. The algorithmic system did not show as much skill in comparison with the dynamic model in providing precipitation forcing to the hydrologic model. The discharge forecasts based on the dynamic-model and algorithmic-system inputs point to the need to improve the ability to forecast convective storms, especially if models such as these eventually are to be used in operational flood forecasting.

  20. Delineation of flooding within the upper Mississippi River Basin, flood of July 10 and 27, 1993, in Kansas City Missouri, and Kansas City, Kansas, and vicinity

    USGS Publications Warehouse

    Perry, Charles A.; Clement, Ralph W.; Studley, Seth E.

    1997-01-01

    During spring and summer 1993, record flooding inundated many of the stream and river valleys in the upper Mississippi and the Missouri River Basins. The flooding was the result of widespread and numerous intense thunderstorms that, together with saturated soils, produced large volumes of runoff. The magnitude of flooding exceeded the 100-year discharge values (1-percent chance of exceedance in any given year) at many streamflow-gaging stations in Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota, and Wisconsin. The flooding was unusual because of its long duration and widespread severe damage. The Mississippi and the Missouri Rivers were above flood stage for more than 1 month at several locations along their lengths. Millions of acres of agricultural and urban lands were inundated for weeks, and unofficial damage estimates exceeded $10 billion in the flooded States (Parrett and others, 1993),During summer 1993, large parts of Kansas City, Missouri, and Kansas City, Kansas, and vicinity were flooded from overflows of the Missouri and the Kansas Rivers and numerous smaller tributaries, This report provides flood-peak elevation data and delineates the arcalcktent of the 1993 floods in the Kansas City metropolitan area for July 10 and 27, 1993 (fig. 1A, sheet 1: B, sheet 2: C, sheet 3). The 1993 flood elevations and extent of flooding are compared with flood-plain boundaries defined by Flood Insurance Studies conducted by the Federal Emergency Management Agency (FEMA) for cities and counties in the area (U.S. Department of Housing and Urban Development, 1975–95).This report is one of a series of U.S. Geological Survey (USGS) investigations that document the effects of the 1993 flooding of the upper Mississippi and the Missouri River Basins and that improve the technical base from which flood-plain management decisions can be made by other agencies.

  1. Flood of May 23, 2004, in the Turkey and Maquoketa River basins, northeast Iowa

    USGS Publications Warehouse

    Eash, David A.

    2006-01-01

    Severe flooding occurred on May 23, 2004, in the Turkey River Basin in Clayton County and in the Maquoketa River Basin in Delaware County following intense thunderstorms over northeast Iowa. Rain gages at Postville and Waucoma, Iowa, recorded 72-hour rainfall of 6.32 and 6.55 inches, respectively, on May 23. Unofficial rainfall totals of 8 to 10 inches were reported in the Turkey River Basin. The peak discharge on May 23 at the Turkey River at Garber streamflow-gaging station was 66,700 cubic feet per second (recurrence interval greater than 500 years) and is the largest flood on record in the Turkey River Basin. The timing of flood crests on the Turkey and Volga Rivers, and local tributaries, coincided to produce a record flood on the lower part of the Turkey River. Three large floods have occurred at the Turkey River at Garber gaging station in a 13-year period. Peak discharges of the floods of June 1991 and May 1999 were 49,900 cubic feet per second (recurrence interval about 150 years) and 53,900 cubic feet per second (recurrence interval about 220 years), respectively. The peak discharge on May 23 at the Maquoketa River at Manchester gaging station was 26,000 cubic feet per second (recurrence interval about 100 years) and is the largest known flood in the upper part of the Maquoketa River Basin.

  2. Flooding in southeastern United States from tropical storm Alberto, July 1994

    USGS Publications Warehouse

    Stamey, T.C.

    1997-01-01

    In July 1994, parts of central and southwestern Georgia, southeastern Albama, and the western panhandle of Florida were devastated by floods resulting from rainfall produced by Tropical Storm Alberto. Entire communities were inundated by flood waters as numerous streams reached peak stages and discharges far greater than previous floods in the Flint, Ocmulgee, and Choctawhatchee River basins. The flooding resulted in 33 deaths in towns and small communities along or near the overflowing streams. President Clinton declared 78 counties as Federal disaster areas; 55 in Georgia, 10 in Alabama, and 13 in Florida. The Flint River and Ocmulgee River basins in Georgi experienced floods that exceeded the 100-year recurrence interval discharge along almost their entire lengths. Travel was disrupted as railroad and highway bridges and culverts were overtopped and, in many cases, washed out. Total food damages to public and private property were estimated at near $1 billion dollars. The destruction caused by this storm serves to emphasize the high cost imposed upon life and property by flood disasters; and thus, highlight the importance of preparing for, monitoring, and documenting such occurrences.In July 1994, parts of central and southwestern Georgia, southeastern Alabama, and the western panhandle of Florida were devastated by floods resulting from rainfall produced by Tropical Storm Alberto. Entire communities were inundated by flood waters as numerous streams reached peak stages and discharges far greater than previous floods in the Flint, Ocmulgee, and Choctawhatchee River basins. The flooding resulted in 33 deaths in towns and small communities along or near the overflowing streams. President Clinton declared 78 counties as Federal disaster areas: 55 in Georgia, 10 in Alabama, and 13 in Florida. The Flint River and Ocmulgee River basins in Georgia experienced floods that exceeded the 100-year recurrence interval discharge along almost their entire lengths. Travel was

  3. Building a flood climatology and rethinking flood risk at continental scales

    NASA Astrophysics Data System (ADS)

    Andreadis, Konstantinos; Schumann, Guy; Stampoulis, Dimitrios; Smith, Andrew; Neal, Jeffrey; Bates, Paul; Sampson, Christopher; Brakenridge, Robert; Kettner, Albert

    2016-04-01

    Floods are one of the costliest natural disasters and the ability to understand their characteristics and their interactions with population, land cover and climate changes is of paramount importance. In order to accurately reproduce flood characteristics such as water inundation and heights both in the river channels and floodplains, hydrodynamic models are required. Most of these models operate at very high resolutions and are computationally very expensive, making their application over large areas very difficult. However, a need exists for such models to be applied at regional to global scales so that the effects of climate change with regards to flood risk can be examined. We use the a modeling framework that includes the VIC hydrologic and the LISFLOOD-FP hydrodynamic model to simulate a 40-year history of flood characteristics at the continental scale, particularly Australia. In order to extend the simulated flood climatology to 50-100 years in a consistent manner, reanalysis datasets have to be used as meteorological forcings to the models. The objective of this study is the evaluation of multiple atmospheric reanalysis datasets (ERA, NCEP, MERRA, JRA) as inputs to the VIC/LISFLOOD-FP model. Comparisons of the simulated flood characteristics are made with both satellite observations of inundation and a benchmark simulation of LISFLOOD-FP being forced by observed flows. The implications of having a climatology of flood characteristics are discussed, and in particular We found the magnitude and timing of floodplain water storage to significantly differ from streamflow in terms of their distribution. Furthermore, floodplain volume gave a much sharper discrimination of high hazard and low hazard periods than discharge, and using the latter can lead to significant overestimation. These results demonstrate that global streamflow statistics or precipitation should not be used to infer flood hazard and risk, but instead a flood inundation climatology is necessary.

  4. Flood-inundation maps for the Tippecanoe River at Winamac, Indiana

    USGS Publications Warehouse

    Menke, Chad D.; Bunch, Aubrey R.

    2015-01-01

    For this study, flood profiles were computed for the Tippecanoe River reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relations at the Tippecanoe River streamgage, in combination with the current (2014) Federal Emergency Management Agency flood-insurance study for Pulaski County. The calibrated hydraulic model was then used to determine nine water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the highest stage of the current stage-discharge rating curve. The 1-percent annual exceedance probability (AEP) flood stage (flood with recurrence intervals within 100 years) has not been determined yet for this streamgage location. The rating has not been developed for the 1-percent AEP because the streamgage dates to only 2001. The simulated water-surface profiles were then used with a geographic information system (GIS) digital elevation model (DEM, derived from Light Detection and Ranging [lidar]) in order to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage 03331753, Tippecanoe River at Winamac, Ind., and forecast stream stages from the NWS AHPS, provides emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

  5. A 2000 year natural record of magnitudes and frequencies for the largest Upper Colorado River floods near Moab, Utah

    NASA Astrophysics Data System (ADS)

    Greenbaum, Noam; Harden, Tessa M.; Baker, Victor R.; Weisheit, John; Cline, Michael L.; Porat, Naomi; Halevi, Rafi; Dohrenwend, John

    2014-06-01

    Using well-established procedures for paleoflood hydrology and employing optically stimulated luminescence (OSL) geochronology, we analyzed a very well-preserved natural record of 44 Upper Colorado River extreme floods with discharges ranging from 1800 to 9200 m3s-1. These are the largest floods occurring during the last 2140 ± 220 years, and this natural record indicates that large floods are much more frequent than can be estimated by extrapolation from the stream gaging record that extends back to 1914. Most of these large floods occurred during the last 500 years, and the two largest floods in the record both exceeded the probable maximum flood (PMF) estimated at 8500 m3s-1 (300,000 cfs) for nearby Moab, Utah. Another four floods, with discharges greater than 7000 m3s-1, occurred during the last two millennia. Flood frequency analyses using the FLDFRQ3 model yields the following values, depending on the Manning n roughness coefficients: 100 yr flood—4670-4990 m3s-1; 500 yr flood—6675-7270 m3s-1; 1000 yr flood—7680-8440 m3s-1. The presumed PMF discharge (8500 m3s-1) gets assigned a recurrence interval of about 1000 years, and the largest historical 1884 flood (3540 m3s-1)—a recurrence interval of <100 years. Flood frequency analysis for the Moab Valley based on the gaged record (1914-2012) yield 2730 m3s-1 for the 100 yr flood and 3185 m3s-1 for the 500 yr flood. This underestimation of the frequency of large floods from the gage data results from effects on that record by modern regulation of upstream river flow and associated water extraction for agriculture.

  6. Flood characteristics for the New River in the New River Gorge National River, West Virginia

    USGS Publications Warehouse

    Wiley, J.B.; Cunningham, M.K.

    1994-01-01

    The frequency and magnitude of flooding of the New River in the New River Gorge National River was studied. A steady-state, one-dimensional flow model was applied to the study reach. Rating curves, cross sections, and Manning's roughness coefficients that were used are presented in this report. Manning's roughness coefficients were evaluated by comparing computed elevations (from application of the steady-state, one-dimensional flow model) to rated elevations at U.S. Geological Survey (USGS) streamflow-gaging stations and miscellaneous-rating sites. Manning's roughness coefficients ranged from 0.030 to 0.075 and varied with hydraulic depth. The 2-, 25-, and 100-year flood discharges were esti- mated on the basis of information from flood- insurance studies of Summers County, Fayette County, and the city of Hinton, and flood-frequency analysis of discharge records for the USGS streamflow-gaging stations at Hinton and Thurmond. The 100-year discharge ranged from 107,000 cubic feet per second at Hinton to 150,000 cubic feet per second at Fayette.

  7. Effects of urbanization on flood characteristics in Nashville-Davidson County, Tennessee

    USGS Publications Warehouse

    Wibben, Herman C.

    1976-01-01

    Streamflow data from 14 basins in Davidson County, Tenn., were extended in time by use of a digital model of the hydrologic system. The basins ranged in size from 1.58 to 64.0 square miles and ranged in extent of manmade impervious cover from 3 to 37 percent. The flood-frequency characteristics were defined by weighting frequency curves based on simulated discharges with those based on observed discharges. The average record length of the three rain gages used in simulation was 72 years, and the average record length of observed discharges was 11 years. Discharges corresponding to 2-, 5-, 10-, 25-, 50-, 100-year floods from the modeled basins were compared with discharges from regional equations for estimating peak discharge rates from rural basins. Basin lag times of the urban basins were compared with those of nearby rural basins. The analyses indicated that in a fully-developed residential area, the flood peaks and the basin lag times will not be significantly different from those expected from an undeveloped area. Data were not sufficient to determine if an increase in flood peaks would occur from extremely small basins with extremely intensive development. (Woodard-USGS)

  8. 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.

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

    USGS Publications Warehouse

    Hauth, L.D.; Carswell, W.J., Jr.; Chin, E.H.

    1981-01-01

    The storms of Sept. 12-13, 1977, delivered as much as 16 in. of rain, with average rainfall exceeding 10 in. in the Kansas City metropolitan area. Twenty-five lives were lost, many were left homeless, and damages exceeded $80 million. Data obtained by the National Weather Service and the U.S. Geological Survey indicate that two record-setting rainstorms occurred within 24 hours. The first storm, in the early morning, thoroughly soaked the local drainage basins. The second storm, centered along the Brush and Round Grove Creek basins, resulted in a devastating flash flood. Peak discharges were determined during and after this major flood at gaging stations and selected miscellaneous locations. Streamflows and flood volumes in many locations far exceeded estimated values for the 100-year flood. (USGS)

  10. Preliminary flood-frequency relations for urban streams, Metropolitan Atlanta, Georgia

    USGS Publications Warehouse

    Golden, Harold G.

    1977-01-01

    A method is presented for estimating the magnitude and frequency of floods for urban streams in metropolitan Atlanta. The method is based on adjustments to the natural stream flood-frequency and rainfall-frequency characteristics of the local area as defined by urban flood studies in other areas. The effects of urbanization on flood-peak runoff are estimated from the percentage of drainage basin that is impervious and the percentage of drainage area served by storm sewers. Equation are presented for estimating the 2-, 5-, 10-, 25-, 50-, and 100-year flood peak discharges for basin sizes from 0.5 to 100 square miles in the Atlanta metro area. Data from 12 urban streams in the Atlanta area were used to obtain a qualitative verification of the 2- and 100-year estimating equations. Hydrologic data are presently being collected for a study that will provide a data base for use in hydrologic models to develop more reliable urban flood-frequency relations. (Woodard-USGS)

  11. Flood of July 9-11, 1993, in the Raccoon River basin, west-central Iowa

    USGS Publications Warehouse

    Eash, D.A.; Koppensteiner, B.A.

    1997-01-01

    Water-surface-elevation profiles and peak discharges for the flood of July 9-11, 1993, in the Raccoon River Basin, west-central Iowa, are presented in this report. The profiles illustrate the 1993 flood along the Raccoon, North Raccoon, South Raccoon, and Middle Raccoon Rivers and along Brushy and Storm Creeks in the west-central Iowa counties of Carroll, Dallas, Greene, Guthrie, and Polk. Water-surface-elevation profiles for the floods of June 1947, March 1979, and June 29- July 1, 1986, in the Raccoon River Basin also are included in the report for comparative purposes. The July 9-11, 1993, flood is the largest known peak discharge at gaging stations Brushy Creek near Templeton (station number 05483318) 19,000 cubic feet per second, Middle Raccoon River near Bayard (station number 05483450) 27,500 cubic feet per second, Middle Raccoon River at Panora (station number 05483600) 22,400 cubic feet per second, South Raccoon River at Redfield (station number 05484000) 44,000 cubic feet per second, and Raccoon River at Van Meter (station number 05484500) 70,100 cubic feet per second. The peak discharges were, respectively, 1.5, 1.3, 1.1,1.2, and 1.3 times larger than calculated 100-year recurrence-interval discharges. The report provides information on flood stages and discharges and floodflow frequencies for streamflow-gaging stations in the Raccoon River Basin using flood information collected through 1996. A flood history summarizes rainfall conditions and damages for floods that occurred during 1947, 1958, 1979, 1986, 1990, and 1993. Information on temporary bench marks and reference points established in the Raccoon River Basin during 1976-79 and 1995-97 also is included in the report.

  12. 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

  13. Flood volumes in the upper Mississippi River basin, April 1 through September 30, 1993

    USGS Publications Warehouse

    Southard, Rodney E.

    1995-01-01

    Previous maximum flows on many streams and rivers were exceeded during the flood of 1993 in the upper Mississippi River Basin. Not only were peak discharges exceeded at many streamflow-gaging stations, but flood volumes were significantly higher than previous maximums. Rainfall amounts that were greater than 50 inches were recorded in parts of Kansas, Missouri, and Iowa from April 1 through September 30, 1993 . As a result of the excess rainfall, 53 of the 60 stations discussed in this report had flow volumes that were greater than twice the mean flow volume for April through September. The Mississippi River at St. Louis, Missouri, remained above flood stage for 144 days from April 1 to September 30, 1993, compared with 81 days during the 1973 flood. Of the 60 stations, 24 recorded new maximum 3-day flood volumes, and 47 recorded new maximum 120- day flood volumes. This indicates that the flooding of 1993 is significant with respect to its long duration and magnitude of flow . The same aspect is indicated in the frequency analysis of the 1993 flood. During the 1993 flood, the 100- year 3-day flows were exceeded at 22 stations, and the 120-day flows were exceeded at 43 stations. 

  14. Estimation of magnitude and frequency of floods for streams in Puerto Rico : new empirical models

    USGS Publications Warehouse

    Ramos-Gines, Orlando

    1999-01-01

    Flood-peak discharges and frequencies are presented for 57 gaged sites in Puerto Rico for recurrence intervals ranging from 2 to 500 years. The log-Pearson Type III distribution, the methodology recommended by the United States Interagency Committee on Water Data, was used to determine the magnitude and frequency of floods at the gaged sites having 10 to 43 years of record. A technique is presented for estimating flood-peak discharges at recurrence intervals ranging from 2 to 500 years for unregulated streams in Puerto Rico with contributing drainage areas ranging from 0.83 to 208 square miles. Loglinear multiple regression analyses, using climatic and basin characteristics and peak-discharge data from the 57 gaged sites, were used to construct regression equations to transfer the magnitude and frequency information from gaged to ungaged sites. The equations have contributing drainage area, depth-to-rock, and mean annual rainfall as the basin and climatic characteristics in estimating flood peak discharges. Examples are given to show a step-by-step procedure in calculating a 100-year flood at a gaged site, an ungaged site, a site near a gaged location, and a site between two gaged sites.

  15. Analysis of the Magnitude and Frequency of Peak Discharge and Maximum Observed Peak Discharge in New Mexico and Surrounding Areas

    USGS Publications Warehouse

    Waltemeyer, Scott D.

    2008-01-01

    (mean value is 62, and median value is 59) for the 100-year flood. The 1996 investigation standard error of prediction for the flood regions ranged from 41 to 96 percent (mean value is 67, and median value is 68) for the 100-year flood that was analyzed by using generalized least-squares regression analysis. Overall, the equations based on generalized least-squares regression techniques are more reliable than those in the 1996 report because of the increased length of record and improved geographic information system (GIS) method to determine basin and climatic characteristics. Flood-frequency estimates can be made for ungaged sites upstream or downstream from gaging stations by using a method that transfers flood-frequency data at the gaging station to the ungaged site by using a drainage-area ratio adjustment equation. The peak discharge for a given recurrence interval at the gaging station, drainage-area ratio, and the drainage-area exponent from the regional regression equation of the respective region is used to transfer the peak discharge for the recurrence interval to the ungaged site. Maximum observed peak discharge as related to drainage area was determined for New Mexico. Extreme events are commonly used in the design and appraisal of bridge crossings and other structures. Bridge-scour evaluations are commonly made by using the 500-year peak discharge for these appraisals. Peak-discharge data collected at 293 gaging stations and 367 miscellaneous sites were used to develop a maximum peak-discharge relation as an alternative method of estimating peak discharge of an extreme event such as a maximum probable flood.

  16. 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)

  17. 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 ...

  18. 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

  19. Role of electrical resistance of electrodes in modeling of discharging and charging of flooded lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Gandhi, K. S.

    2015-03-01

    Electrical resistance of both the electrodes of a lead-acid battery increases during discharge due to formation of lead sulfate, an insulator. Work of Metzendorf [1] shows that resistance increases sharply at about 65% conversion of active materials, and battery stops discharging once this critical conversion is reached. However, these aspects are not incorporated into existing mathematical models. Present work uses the results of Metzendorf [1], and develops a model that includes the effect of variable resistance. Further, it uses a reasonable expression to account for the decrease in active area during discharge instead of the empirical equations of previous work. The model's predictions are compared with observations of Cugnet et al. [2]. The model is as successful as the non-mechanistic models existing in literature. Inclusion of variation in resistance of electrodes in the model is important if one of the electrodes is a limiting reactant. If active materials are stoichiometrically balanced, resistance of electrodes can be very large at the end of discharge but has only a minor effect on charging of batteries. The model points to the significance of electrical conductivity of electrodes in the charging of deep discharged batteries.

  20. Flood hazard assessment of the Hoh River at Olympic National Park ranger station, Washington

    USGS Publications Warehouse

    Kresch, D.L.; Pierson, T.C.

    1987-01-01

    Federal regulations require buildings and public facilities on Federal land to be located beyond or protected from inundation by a 100-year flood. Flood elevations, velocities and boundaries were determined for the occurrence of a 100-year flood through a reach, approximately 1-mi-long, of the Hoh River at the ranger station complex in Olympic National Park. Flood elevations, estimated by step-backwater analysis of the 100-year flood discharge through 14 channel and flood-plain cross sections of the Hoh River, indicate that the extent of flooding in the vicinity of buildings or public facilities at the ranger station complex is likely to be limited mostly to two historic meander channels that lie partly within loop A of the public campground and that average flood depths of about 2 feet or less would be anticipated in these channels. Mean flow velocities at the cross sections, corresponding to the passage of a 100-year flood, ranged from about 5 to over 11 ft/sec. Flooding in the vicinity of either the visitors center or the residential and maintenance areas is unlikely unless the small earthen dam at the upstream end of Taft Creek were to fail. Debris flows with volumes on the order of 100 to 1,000 cu yards could be expected to occur in the small creeks that drain the steep valley wall north of the ranger station complex. Historic debris flows in these creeks have generally traveled no more than about 100 yards out onto the valley floor. The potential risk that future debris flows in these creeks might reach developed areas within the ranger station complex is considered to be small because most of the developed areas within the complex are situated more than 100 yards from the base of the valley wall. Landslides or rock avalanches originating from the north valley wall with volumes potentially much larger than those for debris flows could have a significant impact on the ranger station complex. The probability that such landslides or avalanches may occur is

  1. Progress report on hydrologic investigations of small drainage areas in New Hampshire : preliminary relations for estimating peak discharges on rural, unregulated streams

    USGS Publications Warehouse

    LeBlanc, Denis R.

    1978-01-01

    The magnitude and frequency of floods on rural, unregulated streams in New Hampshire with drainage areas between 0.27 and 622 square miles may be estimated from drainage area, main-channel slope, and a precipitation intensity index. Based on multiple-regression analyses of data from 59 gaged sites in New Hampshire and adjacent areas of bordering states, peak discharges for recurrence intervals of 2, 5, 10, 25, 50, and 100 years can be estimated equations. The estimating relations can be applied to streams where flows are not significantly affected by regulation, diversion, or urbanization; where usable manmade storage does not exceed 4.5 million cubic feet per square mile; or where the basin characteristics are within a specified range. The average standard error of the estimate ranged from 35 percent for the 2-year flood to 58 percent for the 100-year flood. (Woodard-USGS)

  2. Re-Evaluation of the 1921 Peak Discharge at Skagit River near Concrete, Washington

    USGS Publications Warehouse

    Mastin, M.C.

    2007-01-01

    The peak discharge record at the U.S. Geological Survey (USGS) gaging station at Skagit River near Concrete, Washington, is a key record that has come under intense scrutiny by the scientific and lay person communities in the last 4 years. A peak discharge of 240,000 cubic feet per second for the flood on December 13, 1921, was determined in 1923 by USGS hydrologist James Stewart by means of a slope-area measurement. USGS then determined the peak discharges of three other large floods on the Skagit River (1897, 1909, and 1917) by extending the stage-discharge rating through the 1921 flood measurement. The 1921 estimate of peak discharge was recalculated by Flynn and Benson of the USGS after a channel roughness verification was completed based on the 1949 flood on the Skagit River. The 1949 recalculation indicated that the peak discharge probably was 6.2 percent lower than Stewart's original estimate but the USGS did not officially change the peak discharge from Stewart's estimate because it was not more than a 10-percent change (which is the USGS guideline for revising peak flows) and the estimate already had error bands of 15 percent. All these flood peaks are now being used by the U.S. Army Corps of Engineers to determine the 100-year flood discharge for the Skagit River Flood Study so any method to confirm or improve the 1921 peak discharge estimate is warranted. During the last 4 years, two floods have occurred on the Skagit River (2003, 2006) that has enabled the USGS to collect additional data, do further analysis, and yet again re-evaluate the 1921 peak discharge estimate. Since 1949, an island/bar in the study reach has reforested itself. This has complicated the flow hydraulics and made the most recent recalculation of the 1921 flood based on channel roughness verification that used 2003 and 2006 flood data less reliable. However, this recent recalculation did indicate that the original peak-discharge calculation by Stewart may be high, and it added to a

  3. Generation Mechanism and Prediction Model for Low Frequency Noise Induced by Energy Dissipating Submerged Jets during Flood Discharge from a High Dam

    PubMed Central

    Lian, Jijian; Zhang, Wenjiao; Guo, Qizhong; Liu, Fang

    2016-01-01

    As flood water is discharged from a high dam, low frequency (i.e., lower than 10 Hz) noise (LFN) associated with air pulsation is generated and propagated in the surrounding areas, causing environmental problems such as vibrations of windows and doors and discomfort of residents and construction workers. To study the generation mechanisms and key influencing factors of LFN induced by energy dissipation through submerged jets at a high dam, detailed prototype observations and analyses of LFN are conducted. The discharge flow field is simulated using a gas-liquid turbulent flow model, and the vorticity fluctuation characteristics are then analyzed. The mathematical model for the LFN intensity is developed based on vortex sound theory and a turbulent flow model, verified by prototype observations. The model results reveal that the vorticity fluctuation in strong shear layers around the high-velocity submerged jets is highly correlated with the on-site LFN, and the strong shear layers are the main regions of acoustic source for the LFN. In addition, the predicted and observed magnitudes of LFN intensity agree quite well. This is the first time that the LFN intensity has been shown to be able to be predicted quantitatively. PMID:27314374

  4. Generation Mechanism and Prediction Model for Low Frequency Noise Induced by Energy Dissipating Submerged Jets during Flood Discharge from a High Dam.

    PubMed

    Lian, Jijian; Zhang, Wenjiao; Guo, Qizhong; Liu, Fang

    2016-01-01

    As flood water is discharged from a high dam, low frequency (i.e., lower than 10 Hz) noise (LFN) associated with air pulsation is generated and propagated in the surrounding areas, causing environmental problems such as vibrations of windows and doors and discomfort of residents and construction workers. To study the generation mechanisms and key influencing factors of LFN induced by energy dissipation through submerged jets at a high dam, detailed prototype observations and analyses of LFN are conducted. The discharge flow field is simulated using a gas-liquid turbulent flow model, and the vorticity fluctuation characteristics are then analyzed. The mathematical model for the LFN intensity is developed based on vortex sound theory and a turbulent flow model, verified by prototype observations. The model results reveal that the vorticity fluctuation in strong shear layers around the high-velocity submerged jets is highly correlated with the on-site LFN, and the strong shear layers are the main regions of acoustic source for the LFN. In addition, the predicted and observed magnitudes of LFN intensity agree quite well. This is the first time that the LFN intensity has been shown to be able to be predicted quantitatively. PMID:27314374

  5. Studies of current and potential distributions on lead-acid batteries. I. Discharge of automotive flooded positive plates

    NASA Astrophysics Data System (ADS)

    Guo, Yonglang; Li, Yi; Zhang, Guodong; Zhang, Huiming; Garche, J.

    The distributions of current and potential on the automotive positive plate have been studied. In the early stage of the discharge, the distributions of the current density, potential, and polarization resistance are uniform. In the later stage, however, the polarization resistance of the active mass increases very rapidly at the bottom and on the top of the plate. It causes the polarization to become very high and makes the current drop rapidly in these regions. It is also found that at the beginning of the 3 C discharge, the higher current density appears in the lower part rather than in the upper part of the plate, which is different from the conventional viewpoint. This may be due to the improper formation and overcharge of the plate.

  6. 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.

  7. 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.

  8. Flood-plain delineation for Difficult Run Basin, Fairfax County, Virginia

    USGS Publications Warehouse

    Soule, P.L.

    1976-01-01

    Water-surface profiles of the 25-year and 100-year floods and maps on which the 25-, 50-, and 100-year flood boundaries are delineated for streams in the Difficult Run basin in Fairfax County, Virginia. The techniques used in the computation of the flood profiles and delineation of flood boundaries are presented. Difficult Run heads at about 500 ft. elevation near the city of Fairfax and discharges into the Potomac River at about 70 feet above mean sea level. Stream channel slopes are fairly steep, the main channel of Difficult Run has an average fall of about 25 feet per mile. Stream channels are well defined with established flood plains covered in most cases with trees and dense brush. Development within the basin has been gradual and mostly residential. In 1965 most of the development was in the area of Fairfax City and the town of Vienna and imperviousness for the basin at that time was computed to be less than 1 percent. Since 1965 considerable additional residential development has taken place within the basin in the Vienna and Reston areas and ultimate development with an overall imperviousness of 30 percent is anticipated with higher percentages of imperviousness near centers of anticipated development. (Woodard-USGS)

  9. 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

  10. 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.

  11. Flooding of December 29, 1984 through January 2, 1985, in northern New York State, with flood profiles of the Black and Salmon rivers

    USGS Publications Warehouse

    Lumia, Richard; Burke, P.M.; Johnston, W.H.

    1987-01-01

    Precipitation, snowmelt, and resultant flooding throughout northern New York from December 28 through January 2, 1985, were investigated through a detailed analysis of 56 precipitation stations, 101 stage and/or discharge gaging stations, and 9 miscellaneous measurement sites. Flood damage to property and roads and bridges exceeded $5 million. Lewis and Oswego Counties were declared Federal disaster areas, primarily a result of flooding of the Black River and Salmon River. Storm-precipitation and runoff maps show the storms ' greatest intensity to have been over the Tug Hill and southwest Adirondack areas. Total rainfall from December 28 through January 2 was 6.90 inches at Stillwater Reservoir but only 0.69 inches at Lake Placid. New peak discharges of record occurred at 17 gaging stations throughout northern New York, and the maximum discharge at 17 sites had recurrence intervals equal to or greater than 100 years. Computed inflows to 11 major lakes and reservoirs in northern New York indicate that significant volumes of water (as much as 5 inches of storm runoff at Stillwater Reservoir) were stored during the storm-runoff period. Maximum 1-day flood volumes at two gaging stations on the Black River had recurrence intervals greater than 100 years. To help evaluate the extent of flooding, 67 floodmarks were obtained along a 94-mile reach of the Black River from Dexter to Forestport, and several floodmarks were surveyed within major communities along the Salmon River. The floodmarks were obtained primarily near major bridges and dams along these rivers. (Author 's abstract)

  12. Preliminary evaluation of flood frequency relations in the urban areas of Memphis, Tennessee

    USGS Publications Warehouse

    Boning, Charles W.

    1977-01-01

    A storm-runoff relation for streams in the urban areas of Memphis was determined by a statistical evaluation of 59 flood discharges from 19 gaging stations. These flood discharges were related to drainage area, percent imperviousness of the drainage basin, and rainfall occuring over 120-minute periods. The defined relation is Q=m3A*777A - .02 tI,,,,P + 1j-227 (1120).539(t120).40 where Q is flood discharge in cfs, A is drainage area in square miles, IMP is percent imperviousness in the basin, and I120 is rainfall in inches, over 120 minute time period. The defined relation was used to synthesize sets of annual flood peaks for drainage basins ranging from .05 square miles to 10 square miles and imperviousness ranging from 0 to 80 percent for the period of rainfall record at Memphis. From these series of flood peaks, frequency relations were defined and presented for 2, 5, 10, 25, 50 and 100 year recurrent intervals.

  13. 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…

  14. 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. ...

  15. 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)

  16. 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.

  17. Floods of July 19-20, 1977 in the Johnstown area, western Pennsylvania

    USGS Publications Warehouse

    Brua, Stan A.

    1978-01-01

    Intense rainfall on the evening of July 19 and early morning hours of July 20, 1977, resulted in moderate to record flooding throughout much of an eight-county area of southwest Pennsylvania. In a 400-square-mile area directly north and east of Johnstown, rainfall totals of 6 to 12 inches were measured in a six to eight-hour period. Flood peaks having recurrence intervals greater than 100 years were recorded at several sites, primarily in the Conemaugh River basin. Runoff rates were as high as 2,390 cubic feet per second per square mile, in a 5.86-square-mile drainage area in the Little Conemaugh River basin. The Conemaugh River at Seward, which drains 715 square miles, had a peak discharge of 161 cubic feet per second per square mile. The flood waters claimed at least 78 lives and caused total losses in excess of $300 million. Also, seven earthfill dams, used mainly for water supply in the Johnstown area, failed. This report describes the storm and the associated flooding. A tabulation of peak gage heights and discharges for the July 1977 flood and for the maximum flood previously known is included for 57 sites. Data pertaining to the dams that failed are included also. (Woodard-USGS)

  18. Relative impacts of climate and land use changes on future flood damage along River Meuse in Wallonia

    NASA Astrophysics Data System (ADS)

    Beckers, A.; Detrembleur, S.; Dewals, B. J.; Gouverneur, L.; Dujardin, S.; Archambeau, P.; Erpicum, S.; Pirotton, M.

    2012-04-01

    Climate change is expected to increase flood hazard across most of Europe, both in terms of peak discharge intensity and frequency. Consequently, managing flood risk will remain an issue of primary importance for decades to come. Flood risk depends on territories' flood hazard and vulnerability. Beside climate change, land use evolution is thus a key influencing factor on flood risk. The aim of this research is to quantify the relative influence of climate and land use changes on flood damage evolution during the 21st century. The study focuses on River Meuse in Wallonia for a 100-year flood. A scenario-based approach was used to model land use evolution. Nine urbanization scenarios for 2100 were developed: three of them assume a "current tend" land use evolution, characterized by urban sprawl, while six others assume a sustainable spatial planning, leading to an increase in density of residential areas as well as an increase in urban functions diversity. A study commissioned by the EU has estimated a 30 % increase in the 100-year discharge for River Meuse by the year 2100. Inundation modeling was conducted for the present day 100-year flood (HQ100) and for a discharge HQ100 + 30%, using the model Wolf 2D and a 5m grid resolution Digital Elevation Model (Ernst et al. 2009). Based on five different damage curves related to land use categories, the relative damage was deduced from the computed inundation maps. Finally, specific prices were associated to each land use category and allowed assessing absolute damages, which were subsequently aggregated to obtain a damage value for each of the 19 municipalities crossed by River Meuse. Results show that flood damage is estimated to increase by 540 to 630 % between 2009 and 2100, reaching 2.1 to 2.4 billion Euros in 2100. These increases mainly involve municipalities downstream of a point where the floodplain width becomes significantly larger. The city of Liège, which is protected against a 100-year flood in the present

  19. The Effect of Beaver Dams on Geochemistry of the Hyporheic Zone at Varied Depth and Location over a Range of Discharges During Flood Recession

    NASA Astrophysics Data System (ADS)

    Hare, D. K.; Briggs, M.; Lautz, L. K.

    2010-12-01

    As beaver populations increase in the Western United States, beaver dams are becoming more numerous in many incised low-order streams. These dams raise the water table locally, enhancing riparian zone connection and creating pools that increase stream water residence time. Additionally, the stepped drop in stream head over dams enhances hyporheic exchange and creates spatially and temporally transient seepage flux patterns, which may be sensitive to stream discharge. As discharge falls during flood recession, the two main drivers of hyporheic exchange, head and velocity, should also change. Patterns of high seepage flux into the hyporheic zone, indicated by high dissolved oxygen and concentrations of redox sensitive species (i.e. NO3-, Fe, SO42-), may then be transient during periods of large changes in stream discharge. Cherry Creek, a 2nd order stream outside of Lander Wyoming, has a ~2 km reach populated with beaver dams. A small beaver dam (~35 cm in height) and large dam (~75 cm in height) were instrumented with nested piezometers equipped with sampling ports screened at 5-10, 15-20, 30-35, and 50-55 cm intervals. Four sampling stations were installed above the small dam and five above the large dam in locations chosen to best encompass the local geomorphic complexity. Samples were drawn four times at each location over the summer when stream discharge was 383L/s, 331L/s ,268L/s and 259 L/s to determine the effect of changing stream discharge on flux patterns and geochemical conditions in the hyporheic zone. To analyze these flux patterns, pH and DO were measured on-site at the time of sampling and cation (Mg2+, Ca2+, Na+, NH4+) and anion (SO42+, Cl-, NO3-) concentrations were measured in the laboratory using ion chromatography. These data were collected in conjunction with heat flux measurements using distributed temperature sensing (DTS) to determine hyporheic flux patterns. Decreases in dissolved oxygen concentrations in many locations were observed as the

  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. Comparison of flood frequency estimates from synthetic and observed data on small drainage areas in Mississippi

    USGS Publications Warehouse

    Colson, B.E.

    1986-01-01

    In 1964 the U.S. Geological Survey in Mississippi expanded the small stream gaging network for collection of rainfall and runoff data to 92 stations. To expedite availability of flood frequency information a rainfall-runoff model using available long-term rainfall data was calibrated to synthesize flood peaks. Results obtained from observed annual peak flow data for 51 sites having 16 yr to 30 yr of annual peaks are compared with the synthetic results. Graphical comparison of the 2, 5, 10, 25, 50, and 100-year flood discharges indicate good agreement. The root mean square error ranges from 27% to 38% and the synthetic record bias from -9% to -18% in comparison with the observed record. The reduced variance in the synthetic results is attributed to use of only four long-term rainfall records and model limitations. The root mean square error and bias is within the accuracy considered to be satisfactory. (Author 's abstract)

  3. Flood frequency analysis for nonstationary annual peak records in an urban drainage basin

    USGS Publications Warehouse

    Villarini, G.; Smith, J.A.; Serinaldi, F.; Bales, J.; Bates, P.D.; Krajewski, W.F.

    2009-01-01

    Flood frequency analysis in urban watersheds is complicated by nonstationarities of annual peak records associated with land use change and evolving urban stormwater infrastructure. In this study, a framework for flood frequency analysis is developed based on the Generalized Additive Models for Location, Scale and Shape parameters (GAMLSS), a tool for modeling time series under nonstationary conditions. GAMLSS is applied to annual maximum peak discharge records for Little Sugar Creek, a highly urbanized watershed which drains the urban core of Charlotte, North Carolina. It is shown that GAMLSS is able to describe the variability in the mean and variance of the annual maximum peak discharge by modeling the parameters of the selected parametric distribution as a smooth function of time via cubic splines. Flood frequency analyses for Little Sugar Creek (at a drainage area of 110 km2) show that the maximum flow with a 0.01-annual probability (corresponding to 100-year flood peak under stationary conditions) over the 83-year record has ranged from a minimum unit discharge of 2.1 m3 s- 1 km- 2 to a maximum of 5.1 m3 s- 1 km- 2. An alternative characterization can be made by examining the estimated return interval of the peak discharge that would have an annual exceedance probability of 0.01 under the assumption of stationarity (3.2 m3 s- 1 km- 2). Under nonstationary conditions, alternative definitions of return period should be adapted. Under the GAMLSS model, the return interval of an annual peak discharge of 3.2 m3 s- 1 km- 2 ranges from a maximum value of more than 5000 years in 1957 to a minimum value of almost 8 years for the present time (2007). The GAMLSS framework is also used to examine the links between population trends and flood frequency, as well as trends in annual maximum rainfall. These analyses are used to examine evolving flood frequency over future decades. ?? 2009 Elsevier Ltd.

  4. The age and origin of the Labyrinth, western Dry Valleys, Antarctica: Evidence for extensive middle Miocene subglacial floods and freshwater discharge to the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Lewis, Adam R.; Marchant, David R.; Kowalewski, Douglas E.; Baldwin, Suzanne L.; Webb, Laura E.

    2006-07-01

    A 50+-km-long network of bedrock channels and scoured terrain occupies the ice-free portion of a major trough that crosses the Transantarctic Mountains in southern Victoria Land. The channels, collectively termed the Labyrinth, emerge from beneath the margin of the East Antarctic Ice Sheet (Wright Upper Glacier) and are incised into a 300-m-thick sill of Ferrar Dolerite at the head of Wright Valley. Upper- and intermediate-elevation erosion surfaces of the Labyrinth exhibit striations and molding characteristic of glacial erosion. Channels and canyons on the lower surface are as much as 600 m wide and 250 m deep, have longitudinal profiles with many reverse gradients, and contain potholes >35 m deep at tributary junctions. These characteristics are most consistent with incision from fast-flowing subglacial meltwater; estimated discharge is on the order of 1.6 2.2 × 106 m3s-1. Our 40Ar/39Ar analyses of volcanic tephra from the Labyrinth show that the channels are relict, that major channel incision predates 12.4 Ma, and that the last major subglacial flood occurred sometime between 14.4 Ma and 12.4 Ma. The most plausible origin for the Labyrinth is erosion associated with episodic drainage of subglacial lakes in East Antarctica. One compelling possibility is that discharge of large volumes of subglacial meltwater to the Southern Ocean, and to the Ross Sea in particular, may have coincided with, and contributed to, oscillations in regional and/or global climate during the middle Miocene.

  5. Delineation of flooding within the upper Mississippi River Basin-flood of June 18 through August 4, 1993, in Des Moines and vicinity, Iowa

    USGS Publications Warehouse

    Schaap, Bryan D.

    1996-01-01

    This hydrologic investigations atlas shows the areas in and near Des Moines, Iowa, that were flooded by the Des Moines and the Raccoon Rivers and Walnut, Fourmile, and Beaver Creeks from June 18 through August 4, 1993. This map also depicts the Federal Emergency Management Agency 100-year flood boundaries. The area drained by the Des Moines River upstream from Des Moines received more than 100 percent of normal rainfall in May, June, and July, 1993. At Boone, which is located about 35 miles north-northeast of Des Moines, July rainfall was 424 percent of normal. The discharges at streamflow- gaging stations on the Des Moines River near Stratford, downstream from Saylorville Lake, and at Des Moines are shown. The cumulative discharge for inflow-gaging stations in the Des Moines area and discharge for the Des Moines River below the Raccoon River at Des Moines from July 8 through 21, 1993, are shown. The water-surface elevations of Saylorville Lake from June 18 through August 4, 1993, are shown. Profiles of the maximum water- surface elevations of the Des Moines and Raccoon Rivers during the 1993 flood in Des Moines and vicinity are higher than the respective Federal Emergency Management Agency 100- and 500-year flood profiles.

  6. 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

  7. 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.

  8. 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

  9. 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

    The present study sets out to determine the flood plains corresponding to flood discharges having 10, 50 and 100 year recurrence intervals on the Monoroštia, Petriš and Troaš Rivers, located in Western Romania, the Arad department. The data of the study area is first collected and pre-processed in ArcGIS. It consists of land use data, soil data, the DEM, stream gauges' and meteorological stations' locations, on the basis of which the watersheds' hydrologic parameters' are computed using the Geospatial Hydrologic Modelling Extension (HEC Geo-HMS). HEC Geo-HMS functions as an interface between ArcGIS and HEC-HMS (Hydrologic Engineering Centre- Hydrologic Modelling System) and converts the data collected and generated in ArcGIS to data useable by HEC-HMS. The basin model component in HEC-HMS represents the physical watershed. It facilitates the effective rainfall computation on the basis of the input hyetograph, passing the results to a transform function that converts the excess precipitation into runoff at the subwatersheds' outlet. This enables the estimation and creation of hydrographs for the ungauged watersheds. In the present study, the results are achieved through the SCS CN loss method and the SCS Unit hydrograph transform method. The simulations use rainfall data that is registered at the stations situated in the catchments' vicinity, data that spans over two decades (1989-2009) and which allows the rainfall hyetographs to be determined for the above mentioned return periods. The model will be calibrated against measured streamflow data from the gauging stations on the main rivers, leading to the adjustment of watershed parameters, such as the CN parameter. As the flood discharges for 10, 50 and 100 year return periods have been determined, the profile of the water surface elevation along the channel will be computed through a steady flow analysis, with HEC-RAS (Hydrologic Engineering Centre- River Analysis System). For each of the flood frequencies, a

  10. 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.

  11. Flood of June 26-29, 2006, Mohawk, Delaware, and Susquehanna River Basins, New York

    USGS Publications Warehouse

    Suro, Thomas P.; Firda, Gary D.; Szabo, Carolyn O.

    2009-01-01

    A stalled frontal system caused tropical moisture to be funneled northward into New York, causing severe flooding in the Mohawk, Delaware, and Susquehanna River basins during June 26-29, 2006. Rainfall totals for this multi-day event ranged from 2 to 3 inches to greater than 13 inches in southern New York. The storm and flooding claimed four lives in New York, destroyed or damaged thousands of homes and businesses, and closed hundreds of roads and highways. Thousands of people evacuated their homes as floodwaters reached new record elevations at many locations within the three basins. Twelve New York counties were declared Federal disaster areas, more than 15,500 residents applied for disaster assistance, and millions of dollars in damages resulted from the flooding. Disaster-recovery assistance for individuals and businesses adversely affected by the floods of June 2006 reached more than $227 million. The National Weather Service rainfall station at Slide Mountain recorded storm totals of more than 8 inches of rainfall, and the stations at Walton and Fishs Eddy, NY, recorded storm totals of greater than 13 inches of rainfall. The U.S. Geological Survey (USGS) stream-gaging stations at Mohawk River at Little Falls, West Branch Delaware River at Hale Eddy, and Susquehanna River at Vestal, NY, among others, recorded peak discharges of 35,000 ft3/s, 43,400 ft3/s, and 119,000 ft3/s respectively, with greater than 100-year recurrence intervals. The peak water-surface elevation 21.47 ft and the peak discharge 189,000 ft3/s recorded on June 28, 2006, at the Delaware River at Port Jervis stream-gaging station were the highest recorded since the flood of August 1955. At the Susquehanna River at Conklin, NY, stream-gaging station, which has been in operation since 1912, the peak water-surface elevation 25.02 ft and peak discharge 76,800 ft3/s recorded on June 28, 2006, exceeded the previous period-of-record maximums that were set during the flood of March 1936. Documented

  12. Slope-Area Computation Program Graphical User Interface 1.0—A Preprocessing and Postprocessing Tool for Estimating Peak Flood Discharge Using the Slope-Area Method

    USGS Publications Warehouse

    Bradley, D. Nathan

    2012-01-01

    The slope-area method is a technique for estimating the peak discharge of a flood after the water has receded (Dalrymple and Benson, 1967). This type of discharge estimate is called an “indirect measurement” because it relies on evidence left behind by the flood, such as high-water marks (HWMs) on trees or buildings. These indicators of flood stage are combined with measurements of the cross-sectional geometry of the stream, estimates of channel roughness, and a mathematical model that balances the total energy of the flow between cross sections. This is in contrast to a “direct” measurement of discharge during the flood where cross-sectional area is measured and a current meter or acoustic equipment is used to measure the water velocity. When a direct discharge measurement cannot be made at a gage during high flows because of logistics or safety reasons, an indirect measurement of a peak discharge is useful for defining the high-flow section of the stage-discharge relation (rating curve) at the stream gage, resulting in more accurate computation of high flows. The Slope-Area Computation program (SAC; Fulford, 1994) is an implementation of the slope-area method that computes a peak-discharge estimate from inputs of water-surface slope (from surveyed HWMs), channel geometry, and estimated channel roughness. SAC is a command line program written in Fortran that reads input data from a formatted text file and prints results to another formatted text file. Preparing the input file can be time-consuming and prone to errors. This document describes the SAC graphical user interface (GUI), a crossplatform “wrapper” application that prepares the SAC input file, executes the program, and helps the user interpret the output. The SAC GUI is an update and enhancement of the slope-area method (SAM; Hortness, 2004; Berenbrock, 1996), an earlier spreadsheet tool used to aid field personnel in the completion of a slope-area measurement. The SAC GUI reads survey data

  13. 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.

  14. Floods in the Raccoon River basin, Iowa

    USGS Publications Warehouse

    Heinitz, Albert J.

    1980-01-01

    Evaluation of flood hazards, and the planning, design, and operation of various facilities on flood plains requires information on floods. This report provides information on flood stages and discharges, flood magnitude and frequency, bench mark data, and flood profiles for the Raccoon River and some of its tributaries. Ir covers the Raccoon River, the North Raccoon River to the northern boundary of Sac County and the lower reaches of the Middle and South Raccoon Rivers.

  15. 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

  16. 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.

  17. Estimation of flood volumes and simulation of flood hydrographs for ungaged small rural streams in Ohio

    USGS Publications Warehouse

    Sherwood, J.M.

    1993-01-01

    Methods are presented for estimating flood volumes and simulating flood hydrographs of rural streams in Ohio whose drainage areas are less than 6.5 square miles. The methods were developed to assist engineers in the design of hydraulic structures for which the temporary storage of water is a critical element of the design criteria. Examples of how to use the methods also are presented. Multiple-regression equations were developed to estimate maximum flood volumes of d-hour duration and T-year recurrence interval (dVT). Flood-volume data for all combinations of six durations (1, 2, 4, 8, 16, and 32 hours) and six recurrence intervals (2, 5, 10, 25, 50, and 100 years) were analyzed. The significant independent variables in the resulting 36 equations are drainage area, average annual precipitation, main-channel slope, and forested area. Standard errors of prediction for the 36 dVT equations range from +28 percent to +44 percent. A method is described for simulating flood hydrographs by applying a peak discharge and an estimated basin lagtime to a dimensionless hydrograph. Peak discharge may be estimated from equations in which drainage area, main-channel slope, and storage area are the significant explanatory variables, and average standard errors of prediction range from +33 to +41 percent. An equation is developed for estimating basin lagtime in which main-channel slope, forested area, and storage area are the significant explanatory variables, and the average standard error of prediction is +37 percent. A dimensionless hydrograph developed for use in Georgia was verified for use in Ohio. Step-by-step examples show how to (1) simulate flood hydrographs and compute their volumes, and (2) estimate volume-duration-frequency relations of small ungaged rural streams in Ohio. The volumes estimated by the two methods are compared. Both methods yield similar results for volume estimates of short duration, which are applicable to convective-type storm runoff. The volume

  18. Flood frequency in Alaska

    USGS Publications Warehouse

    Childers, J.M.

    1970-01-01

    Records of peak discharge at 183 sites were used to study flood frequency in Alaska. The vast size of Alaska, its great ranges of physiography, and the lack of data for much of the State precluded a comprehensive analysis of all flood determinants. Peak stream discharges, where gaging-station records were available, were analyzed for 2-year, 5-year, 10-year, 25-year, and 50-year average-recurrence intervals. A regional analysis of the flood characteristics by multiple-regression methods gave a set of equations that can be used to estimate floods of selected recurrence intervals up to 50 years for any site on any stream in Alaska. The equations relate floods to drainage-basin characteristics. The study indicates that in Alaska the 50-year flood can be estimated from 10-year gaging- station records with a standard error of 22 percent whereas the 50-year flood can be estimated from the regression equation with a standard error of 53 percent. Also, maximum known floods at more than 500 gaging stations and miscellaneous sites in Alaska were related to drainage-area size. An envelope curve of 500 cubic feet per second per square mile covered all but 2 floods in the State.

  19. 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.

  20. 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.

  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. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Analysis of Flood-Magnitude and Flood-Frequency Data for Streamflow-Gaging Stations in the Delaware and North Branch Susquehanna River Basins in Pennsylvania

    USGS Publications Warehouse

    Roland, Mark A.; Stuckey, Marla H.

    2007-01-01

    -rank test showed a significant difference at the 95-percent confidence level between the Q100 computed from AMS station data and the Q100 determined from previously published FIS for 97 sites. The flood-frequency discharges computed from AMS station data were consistently larger than the flood discharges from the FIS; mean percentage difference between the two data sets ranged from 14 percent for the Q100 to 20 percent for the Q50. The results of the Mann-Kendall test showed that 8 stations exhibited a positive trend (i.e., increasing annual maximum peaks over time) over their respective periods of record at the 95-percent confidence level, and an additional 7 stations indicated a positive trend, for a total of 15 stations, at a confidence level of greater than or equal to 90 percent. The Q2, Q5, Q10, Q50, and Q100 determined from AMS and PDS data for each station were compared by percentage. The flood magnitudes for the 2-year return period were 16 percent higher when partial-duration peaks were incorporated into the analyses, as opposed to using only the annual maximum peaks. The discharges then tended to converge around the 5-year return period, with a mean collective difference of only 1 percent. At the 10-, 50-, and 100-year return periods, the flood magnitudes based on annual maximum peaks were, on average, 6 percent higher compared to corresponding flood magnitudes based on partial-duration peaks. Possible effects on flood peaks from flood-control reservoirs and urban development within the basin also were examined. Annual maximum peak-flow data from four stations were divided into pre- and post-regulation periods. Comparisons were made between the Q100 determined from AMS station data for the periods of record pre- and post-regulation. Two stations showed a nearly 60- and 20-percent reduction in the 100-year discharges; the other two stations showed negligible differences in discharges. Three stations within urban basins were compared to 38 stations

  11. 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.

  12. 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)

  13. 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)

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

    USGS Publications Warehouse

    Zarriello, Phillip J.; Carlson, Carl S.

    2009-01-01

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

  15. Bivariate analysis of flood peaks and volumes using copulas. An application to the Danube River

    NASA Astrophysics Data System (ADS)

    Papaioannou, George; Bacigal, Tomas; Jeneiova, Katarina; Kohnová, Silvia; Szolgay, Jan; Loukas, Athanasios

    2014-05-01

    A multivariate analysis on flood variables such as flood peaks, volumes and durations, is essential for hydrotechnical projects design. A lot of authors have suggested the use of bivariate distributions for the frequency analysis of flood peaks and volumes due to the supposition that the marginal probability distribution type is the same for these variables. The application of Copulas, which are becoming gradually widespread, can overcome this constraint. The selection of the appropriate copula type/families is not extensively treated in the literature and it remains a challenge in copula analysis. In this study a bivariate copula analysis with the use of different copula families is carried out on the basis of flood peak and the corresponding volumes along a river. This bivariate analysis of flood peaks and volumes is based on streamflow daily data of a time-series more than 100 years from several gauged stations of the Danube River. The methodology applied using annual maximum flood peaks (AMF) with the independent annual maximum volumes of fixed durations at 5, 10, 15,20,25,30 and 60 days. The discharge-volume pairs correlation are examined using Kendall's tau correlation analysis. The copulas families that selected for the bivariate modeling of the extracted pairs discharge and volumes are the Archimedean, Extreme-value and other copula families. The evaluation of the copulas performance achieved with the use of scatterplots of the observed and bootstrapped simulated pairs and formal tests of goodness of fit. Suitability of copulas was statistically compared. Archimedean (e.g. Frank and Clayton) copulas revealed to be more capable for bivariate modeling of floods than the other examined copula families at the Danube River. Results showed in general that copulas are effective tools for bivariate modeling of the two study random variables.

  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. 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

  18. 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

  19. [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

  20. 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

  1. 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

  2. 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

  3. [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

  4. 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.

  5. Analysis of the Magnitude and Frequency of Peak Discharges for the Navajo Nation in Arizona, Utah, Colorado, and New Mexico

    USGS Publications Warehouse

    Waltemeyer, Scott D.

    2006-01-01

    data used in the ordinary least-squares regression analyses. The average standard error of prediction for a peak discharge have a recurrence interval of 100-years for region 8 was 53 percent (average) for the 100-year flood. The average standard of prediction, which includes average sampling error and average standard error of regression, ranged from 45 to 83 percent for the 100-year flood. Estimated standard error of prediction for a hybrid method for region 11 was large in the 1997 investigation. No distinction of floods produced from a high-elevation region was presented in the 1997 investigation. Overall, the equations based on generalized least-squares regression techniques are considered to be more reliable than those in the 1997 report because of the increased length of record and improved GIS method. Techniques for transferring flood-frequency relations to ungaged sites on the same stream can be estimated at an ungaged site by a direct application of the regional regression equation or at an ungaged site on a stream that has a gaging station upstream or downstream by using the drainage-area ratio and the drainage-area exponent from the regional regression equation of the respective region.

  6. 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 --

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. A technique for determining depths for T-year discharges in rigid-boundary channels

    USGS Publications Warehouse

    Burkham, D.E.

    1977-01-01

    A simplified technique is presented for determining depths for T-year discharges (the discharge that will occur, on an average, once in T-years--10 years, 50 years, 100 years) for natural channels (channels not significantly affected by manmade structures) having channel-control conditions and rigid boundaries (channels having a low probability of change that would significantly affect the hydraulic characteristics of a T-year discharge). Channel-control conditions usually exist during T-year discharges in natural rigid-boundary channels and, therefore, the simplified technique probably would be applicable for flood-inundation studies for many natural rigid-boundary channels. The technique requires that the T-year discharge for a reach be known or readily available; also, a channel-shape factor, a width at a reference altitude, a channel-bottom slope (or a water-surface slope), and the Manning 's roughness factor, n, must be estimated or determined at representative sections having channel-control conditions. The standard error of estimate for depths determined according to the simplified technique is probably 25-30 percent. In comparison, the standard error of estimate for the depths determined according to the step-backwater procedure and to guidelines and specifications for flood-insurance studies of the Federal Insurance Administration is about 23 percent. (Woodard-USGS)

  12. Evaluation of six methods for estimating magnitude and frequency of peak discharges on urban streams in New York

    USGS Publications Warehouse

    Stedfast, D.A.

    1986-01-01

    Six methods of estimating peak discharges of urban streams were compared and evaluated for applicability to urban streams in New York. Discharge and frequency values developed from a series of synthesized annual flood records were compared with values obtained from the six methods. The synthesized flood records were computed from rainfall-runoff models of 11 urban basins in three counties across the State. Four of these basins had a sufficient period of record to enable rainfall-runoff modeling of two different 5-year periods so that increases in peak flow due to increased urbanization could also be used for comparison of the six methods. A graphical analysis and three types of mathematical analyses were made to evaluate the closeness of fit and bias of the methods. All methods showed a tendency to overestimate synthetic urban flood-magnitude values, but the two adjust rural flood-frequency estimates on a nationwide basis showed smallest standard errors of estimate and bias. The standard errors for these two methods ranged from 44 to 57 percent over the six recurrence intervals (2, 5, 10, 25, 50, and 100 year), and the bias ranged from +28 to +53 percent. The bias , however, is probably due to errors inherent in using synthetic records and in applying the New York rural flood-frequency equations to urban basins with small drainage areas. (USGS)

  13. Global warming increases the frequency of river floods in Europe

    NASA Astrophysics Data System (ADS)

    Alfieri, L.; Burek, P.; Feyen, L.; Forzieri, G.

    2015-05-01

    EURO-CORDEX (Coordinated Downscaling Experiment over Europe), a new generation of downscaled climate projections, has become available for climate change impact studies in Europe. New opportunities arise in the investigation of potential effects of a warmer world on meteorological and hydrological extremes at regional scales. In this work, an ensemble of EURO-CORDEX RCP8.5 scenarios is used to drive a distributed hydrological model and assess the projected changes in flood hazard in Europe through the current century. Changes in magnitude and frequency of extreme streamflow events are investigated by statistical distribution fitting and peak over threshold analysis. A consistent method is proposed to evaluate the agreement of ensemble projections. Results indicate that the change in frequency of discharge extremes is likely to have a larger impact on the overall flood hazard as compared to the change in their magnitude. On average, in Europe, flood peaks with return periods above 100 years are projected to double in frequency within 3 decades.

  14. Techniques for simulating flood hydrographs and estimating flood volumes for ungaged basins in east and west Tennessee

    USGS Publications Warehouse

    Gamble, C.R.

    1989-01-01

    A dimensionless hydrograph developed for a variety of basin conditions in Georgia was tested for its applicability to streams in East and West Tennessee by comparing it to a similar dimensionless hydrograph developed for streams in East and West Tennessee. Hydrographs of observed discharge at 83 streams in East Tennessee and 38 in West Tennessee were used in the study. Statistical analyses were performed by comparing simulated (or computed) hydrographs, derived by application of the Georgia dimensionless hydrograph, and dimensionless hydrographs developed from Tennessee data, with the observed hydrographs at 50 and 75% of their peak-flow widths. Results of the tests indicate that the Georgia dimensionless hydrography is virtually the same as the one developed for streams in East Tennessee, but that it is different from the dimensionless hydrograph developed for streams in West Tennessee. Because of the extensive testing of the Georgia dimensionless hydrograph, it was determined to be applicable for East Tennessee, whereas the dimensionless hydrograph developed from data on streams in West Tennessee was determined to be applicable in West Tennessee. As part of the dimensionless hydrograph development, an average lagtime in hours for each study basin, and the volume in inches of flood runoff for each flood event were computed. By use of multiple-regression analysis, equations were developed that relate basin lagtime to drainage area size, basin length, and percent impervious area. Similarly, flood volumes were related to drainage area size, peak discharge, and basin lagtime. These equations, along with the appropriate dimensionless hydrograph, can be used to estimate a typical (average) flood hydrograph and volume for recurrence-intervals up to 100 years at any ungaged site draining less than 50 sq mi in East and West Tennessee. (USGS)

  15. 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

  16. 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.

  17. 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).

  18. 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

  19. John Hughlings Jackson and our understanding of the epilepsies 100 years on.

    PubMed

    Iniesta, Ivan

    2011-02-01

    The term Jacksonian epilepsy was coined by Jean Martin Charcot following John Hughlings Jackson's 1870 paper 'A study of convulsions', where he had defined a convulsion as "a symptom resulting from an occasional, an excessive and a disorderly discharge of nerve tissue on muscles". His earlier writings had included cases of syphilis related epilepsy, and the introduction of the first successful antiepileptic drugs-the bromides. Based on careful clinical observation or, as Hughlings Jackson himself put it, on the "experiments performed by disease", 'A study of convulsions' was a synthesis of those previous reports which has contributed to our practical understanding of epilepsy, a contribution which continues to inform our thinking to the present day. PMID:21239653

  20. 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 lack reliable hazard information. One example has been the 2011 Thailand floods where millions of people were affected and the total economic losses were 30 billion USD. In order to assess the flood risk across different regions and countries, the flood team at Swiss Re based on a Geomorphologic Regression approach, developed in house and patented, produced global maps of flood zones. Input data for the study was obtained from NASA's Shuttle Radar Topographic Mission (SRTM) elevation data, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) and HydroSHEDS. The underlying assumptions of the approach are that naturally flowing rivers shape their channel and flood plain according to basin inherent forces and characteristics and that the flood water extent strongly depends on the shape of the flood plain. On the basis of the catchment characteristics, the model finally calculates the probability of a location to be flooded or not for a defined return period, which in the current study was set to 100 years. The data is produced at a 90-m resolution for latitudes 60S to 60N. This global product is now used in the insurance industry to inspect, inform and/or insure the flood risk across the world.

  1. Elemental chemistry of sand-boil discharge used to trace variable pathways of seepage beneath levees during the 2011 Mississippi River flood

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water samples were collected from the Mississippi River, from sand boils near the toe of the levee on the Mississippi side of the river, and from actively flowing relief wells shortly after peak stage of the 2011 Mississippi River flood. Two distinct pathways for seepage under the levee were identif...

  2. The end of trend-estimation for extreme floods under climate change?

    NASA Astrophysics Data System (ADS)

    Schulz, Karsten; Bernhardt, Matthias

    2016-04-01

    An increased risk of flood events is one of the major threats under future climate change conditions. Therefore, many recent studies have investigated trends in flood extreme occurences using historic long-term river discharge data as well as simulations from combined global/regional climate and hydrological models. Severe floods are relatively rare events and the robust estimation of their probability of occurrence requires long time series of data (6). Following a method outlined by the IPCC research community, trends in extreme floods are calculated based on the difference of discharge values exceeding e.g. a 100-year level (Q100) between two 30-year windows, which represents prevailing conditions in a reference and a future time period, respectively. Following this approach, we analysed multiple, synthetically derived 2,000-year trend-free, yearly maximum runoff data generated using three different extreme value distributions (EDV). The parameters were estimated from long term runoff data of four large European watersheds (Danube, Elbe, Rhine, Thames). Both, Q100-values estimated from 30-year moving windows, as well as the subsequently derived trends showed enormous variations with time: for example, estimating the Extreme Value (Gumbel) - distribution for the Danube data, trends of Q100 in the synthetic time-series range from -4,480 to 4,028 m³/s per 100 years (Q100 =10,071m³/s, for reference). Similar results were found when applying other extreme value distributions (Weibull, and log-Normal) to all of the watersheds considered. This variability or "background noise" of estimating trends in flood extremes makes it almost impossible to significantly distinguish any real trend in observed as well as modelled data when such an approach is applied. These uncertainties, even though known in principle are hardly addressed and discussed by the climate change impact community. Any decision making and flood risk management, including the dimensioning of flood

  3. Outburst floods from glacial Lake Missoula

    NASA Astrophysics Data System (ADS)

    Clarke, G. K. C.; Mathews, W. H.; Pack, R. T.

    1984-11-01

    The Pleistocene outburst floods from glacial Lake Missoula, known as the "Spokane Floods", released as much as 2184 km 3 of water and produced the greatest known floods of the geologic past. A computer simulation model for these floods that is based on physical equations governing the enlargement by water flow of the tunnel penetrating the ice dam is described. The predicted maximum flood discharge lies in the range 2.74 × 10 6-13.7 × 10 6 m 3 sec -1, lending independent glaciological support to paleohydrologic estimates of maximum discharge.

  4. ANNUS MIRABILIS. PHYSICS OF OUR DAYS: Geometry and Physics after 100 Years of Einstein's Relativity (5-8 April 2005)

    NASA Astrophysics Data System (ADS)

    Braginsky, Vladimir B.

    2005-06-01

    As part of the celebration of the World Year of Physics, the Conference "Geometry and Physics after 100 Years of Einstein's Relativity" was held in Golm, near Potsdam, Germany, on April 5-8, 2005. The Conference was organized by the Max Planck Institute for Gravitational Physics (also known as the Albert Einstein Institute), which is celebrating its 10th anniversary in 2005. Conference participants discussed progress made in theoretical and experimental research during the 100 years since the publication of Einstein's famous papers in 1905, the year which has gone down in history as 'Albert Einstein's ANNUS MIRABILIS'.

  5. 100 years of Cosmic Rays - from the ionisation of air to beyond the LHC

    NASA Astrophysics Data System (ADS)

    Watson, Alan

    2012-03-01

    The study of cosmic rays has impacted on many disciplines, including astrophysics, particle physics, carbon dating and radio astronomy: it has thus had scientific and societal impact. They were discovered in 1912 as a result of the efforts by some of the most distinguished scientists of that era, puzzled by their inability to explain the discharge of ionisation chambers. I will describe some of the early work that led, inter alia, to the discovery of the positron, the muon and the first strange particles and thus to the birth of particle physics. In 1938 it was found that showers of particles that arrive at the earth simultaneously are produced by primary cosmic rays of ˜10^15 eV, about 10^5 times more energetic than any particles that had been contemplated before. I will discuss how study of these showers has led to the discovery of cosmic rays of energies as great as 3 x 10^20 eV, challenging our understanding of where and how they are created. Data from the Pierre Auger Observatory, the largest cosmic-ray detector ever built, is now being used for astrophysical studies and to give glimpses of some hadronic physics at centre-of-mass energies more than 4 times greater than are accessible at the LHC.

  6. When and how long to flood for insect control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flooding in late spring (late May or early July) can remove tremendous numbers of arthropods from cranberry beds. For over 100 years, the Wisconsin cranberry industry has used flooding as a way to suppress arthropod populations. One critical element of this strategy is the trade-off between lethalit...

  7. Structural master plan of flood mitigation measures

    NASA Astrophysics Data System (ADS)

    Heidari, A.

    2009-01-01

    Flood protection is one of the practical methods in damage reduction. Although it not possible to be completely protected from flood disaster but major part of damages can be reduced by mitigation plans. In this paper, the optimum flood mitigation master plan is determined by economic evaluation in trading off between the construction costs and expected value of damage reduction as the benefits. Size of the certain mitigation alternative is also be obtained by risk analysis by accepting possibility of flood overtopping. Different flood mitigation alternatives are investigated from various aspects in the Dez and Karun river floodplain areas as a case study in south west of IRAN. The results show that detention dam and flood diversion are the best alternatives of flood mitigation methods as well as enforcing the flood control purpose of upstream multipurpose reservoirs. Dyke and levees are not mostly justifiable because of negative impact on down stream by enhancing routed flood peak discharge magnitude and flood damages as well.

  8. Studying the extremes: hydrometeorological investigation of a flood-causing rainstorm over Israel

    NASA Astrophysics Data System (ADS)

    Morin, E.; Harats, N.; Jacoby, Y.; Arbel, S.; Getker, M.; Arazi, A.; Grodek, T.; Ziv, B.; Dayan, U.

    2007-08-01

    Analysis of extreme hydrometeorological events is important for characterizing and better understanding the meteorological conditions that can generate severe rainstorms and the consequent catastrophic flooding. According to several studies (e.g., Alpert et al., 2004; Wittenberg et al., 2007), the occurrence of such extreme events is increasing over the eastern Mediterranean although total rain amounts are generally decreasing. The current study presents an analysis of an extreme event utilizing different methodologies: (a) synoptic maps and high resolution satellite imagery for atmospheric condition analysis; (b) rainfall analysis by rain gauges data; (c) meteorological radar rainfall calibration and analysis; (d) field measurements for estimating maximum peak discharges; and, (e) high resolution aerial photographs together with field surveying for quantifying the geomorphic impacts. The unusual storm occurred over Israel between 30 March and 2 April, 2006. Heavy rainfall produced more than 100 mm in some locations in only few hours and more than 200 mm in the major core area. Extreme rain intensities with recurrence intervals of more than 100 years were found for durations of 1 h and more as well as for the daily rain depth values. In the most severely affected area, Wadi Ara, extreme flash floods caused damages and casualties. Specific peak discharges were as high as 10-30 m³/s/km² for catchments of the size of 1-10 km², values larger than any recorded floods in similar climatic regions in Israel.

  9. A Lower Rhine flood chronology based on the sedimentary record of an abandoned channel fill

    NASA Astrophysics Data System (ADS)

    Toonen, W. H. J.; Winkels, T. G.; Prins, M. A.; de Groot, L. V.; Bunnik, F. P. M.; Cohen, K. M.

    2012-04-01

    The Bienener Altrhein is an abandoned channel of the Lower Rhine (Germany). Following a late 16th century abandonment event, the channel was disconnected from the main stream and the oxbow lake gradually filled with 8 meters of flood deposits. This process still continues today. During annual floods, a limited proportion of overbank discharge is routed across the oxbow lake. Large floods produce individual flood layers, which are visually recognized in the sedimentary sequence. Based on the sedimentary characteristics of these event layers, we created a ~450-year flood chronology for the Lower Rhine. Laser-diffraction grain size measurements were used to assess relative flood magnitudes for individual flood event layers. Continuous sampling at a ~2 cm interval provided a high-resolution record, resolving the record at an annual scale. Standard descriptive techniques (e.g., mean grain size, 95th percentile, % sand) and the more advanced 'end member modelling' were applied to zoom in on the coarse particle bins in the grain size distributions, which are indicative of higher flow velocities. The most recent part of the record was equated to modern discharge measurements. This allows to establish relations between deposited grain size characteristics in the abandoned channel and flood magnitudes in the main river. This relation can also be applied on flood event layers from previous centuries, for which only water level measurements and historical descriptions exist. This makes this method relevant to expand data series used in flood frequency analysis from 100 years to more than 400 years. To date event-layers in the rapidly accumulated sequence, we created an age-depth model that uses organic content variations to tune sedimentation rates between the known basal and top ages. No suitable identifiable organic material for radiocarbon dating was found in the cores. Instead, palynological results (introduction of agricultural species) and palaeomagnetic secular

  10. The Bee Disease Diagnostic Service - 100 Years and Growing at the USDA Bee Research laboratory, Beltsville, MD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article discusses the history of honey bee research in the Washington, D.C. area including the 100 year old bee disease diagnostic service available for beekeepers and apiary inspectors. This service provides the Bee Research Laboratory with first-hand knowledge of the problems facing the beek...

  11. Looking toward the Future: New Research Helps Black Sororities and Fraternities Consider New Governing Structures for the Next 100 Years

    ERIC Educational Resources Information Center

    Ruffins, Paul

    2004-01-01

    From a historical perspective, it's interesting to note that at their 100-year mark Black fraternities and sororities are facing some of the very same political criticisms encountered half a century ago. The Black Greeks' ability to be a greater force for social change is also constrained by the basic internal structures of the organizations…

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

    USGS Publications Warehouse

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

    2007-01-01

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

  13. Predicting Flood Hazards in Systems with Multiple Flooding Mechanisms

    NASA Astrophysics Data System (ADS)

    Luke, A.; Schubert, J.; Cheng, L.; AghaKouchak, A.; Sanders, B. F.

    2014-12-01

    Delineating flood zones in systems that are susceptible to flooding from a single mechanism (riverine flooding) is a relatively well defined procedure with specific guidance from agencies such as FEMA and USACE. However, there is little guidance in delineating flood zones in systems that are susceptible to flooding from multiple mechanisms such as storm surge, waves, tidal influence, and riverine flooding. In this study, a new flood mapping method which accounts for multiple extremes occurring simultaneously is developed and exemplified. The study site in which the method is employed is the Tijuana River Estuary (TRE) located in Southern California adjacent to the U.S./Mexico border. TRE is an intertidal coastal estuary that receives freshwater flows from the Tijuana River. Extreme discharge from the Tijuana River is the primary driver of flooding within TRE, however tide level and storm surge also play a significant role in flooding extent and depth. A comparison between measured flows at the Tijuana River and ocean levels revealed a correlation between extreme discharge and ocean height. Using a novel statistical method based upon extreme value theory, ocean heights were predicted conditioned up extreme discharge occurring within the Tijuana River. This statistical technique could also be applied to other systems in which different factors are identified as the primary drivers of flooding, such as significant wave height conditioned upon tide level, for example. Using the predicted ocean levels conditioned upon varying return levels of discharge as forcing parameters for the 2D hydraulic model BreZo, the 100, 50, 20, and 10 year floodplains were delineated. The results will then be compared to floodplains delineated using the standard methods recommended by FEMA for riverine zones with a downstream ocean boundary.

  14. Floods on Yahara River, Lake Kegonsa dam to county line, Dane County, Wisconsin

    USGS Publications Warehouse

    Lawrence, Carl L.; Holmstrom, Barry K.

    1972-01-01

    The regional flood is defined by the Wisconsin Department of Natural Resources as a flood having an average frequency of occurrence of-once in 100 years and "which is representative of large floods known to have occurred generally in Wisconsin and reasonably characteristics of what can be expected to occur on a particular stream."

  15. Re-visiting spring flooding as an IPM approach in Wisconsin cranberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For over 100 years, flooding has been used to suppress arthropod pests of cranberries, yet questions remain as to the trade-off between pest control and flood-induced plant damage. In Wisconsin, there is much interest in the spring flood as a means to not only reduce pest populations, but also to fa...

  16. Development of a Flood-Warning System and Flood-Inundation Mapping for the Blanchard River in Findlay, Ohio

    USGS Publications Warehouse

    Whitehead, Matthew T.; Ostheimer, Chad J.

    2009-01-01

    Digital flood-inundation maps of the Blanchard River in Findlay, Ohio, were created by the U.S. Geological Survey (USGS) in cooperation with the City of Findlay, Ohio. The maps, which correspond to water levels at the USGS streamgage at Findlay (04189000), were provided to the National Weather Service (NWS) for incorporation into a Web-based flood-warning system that can be used in conjunction with NWS flood-forecast data to show areas of predicted flood inundation associated with forecasted flood-peak stages. The USGS reestablished one streamgage and added another on the Blanchard River upstream of Findlay. Additionally, the USGS established one streamgage each on Eagle and Lye Creeks, tributaries to the Blanchard River. The stream-gage sites were equipped with rain gages and multiple forms of telemetry. Data from these gages can be used by emergency management personnel to determine a course of action when flooding is imminent. Flood profiles computed by means of a step-backwater model were prepared and calibrated to a recent flood with a return period exceeding 100 years. The hydraulic model was then used to determine water-surface-elevation profiles for 11 flood stages with corresponding streamflows ranging from approximately 2 to 100 years in recurrence interval. The simulated flood profiles were used in combination with digital elevation data to delineate the flood-inundation areas. Maps of Findlay showing flood-inundation areas overlain on digital orthophotographs are presented for the selected floods.

  17. 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.

  18. Flooding in Bifurcation

    NASA Astrophysics Data System (ADS)

    Aoki, Masakazu; Matumoto, Aoki

    2010-05-01

    Edo River to diverge from Tone River on the right side flows away through Tokyo downtown, and into Tokyo Bay. Tone River of main stream flows through the north region of Kanto into Chiba prefecture of rural aria. Tone River originally flowed through present Edo River into Tokyo downtown. So when Tokyo (Edo era) became the political center of Japan 400 years ago, this place had been suffered from flood caused by augmenting downstream flowing of rainfall over watershed catchment area. Edo Government extended near independent small rivers and connected with Tone River and led away most of flood water transportation into Chiba prefecture to be a rural reason. The present rout of the river has been determined in the mass during the 16th century. Created artificial Edo River experimentally divided into 40 percentage and artificial Tone River divided into 60 percentage of flood water transportation. After that Japanese Government confirmed a safety against flood and confirmed to be a safety Tokyo by using SFM (storage function method) and SNFM (steady non-uniform flow method). Japanese Government estimated Plan High Water Discharge 17,500m3/s at upstream of the divergent point and Edo river flowing through 40 percentage (7,000m3/s) of 17,500m3/s which was same ratio as Edo era. But SFM and SNFM could not explain dynamic flow phenomena. We surveyed how many channel storage amount were there in this river by using UFM (unsteady flow method). We reproduce real flowing shape and carried out more detail dynamic phenomena. In this research, we had taken up diverse and various 11floods from 1981. These floods were confirmed that Edo River to be bifurcated less than 40 percentages. Large flood are not always high ratio of diversion in to Edo River. It's almost smaller ratio rather than higher ratio. For example, peak discharge 11,117m3/s, Aug. 1982 flood was bifurcated into Edo river flowing through 20 percentage of 11,117m3/s. Small flood peak discharge 1,030m3/s, Aug. 1992

  19. Towards a robust calving and melt-history for Helheim Glacier, SE Greenland, for the last 100 years

    NASA Astrophysics Data System (ADS)

    Andersen, T. J.; Ellegaard, M.; Markussen, T. N.

    2013-12-01

    Observations of increased ice-discharge from tidewater glaciers in Greenland in the early and mid 2000s has led to concern about a possible rapid loss of ice from the ice sheet in a scenario with increasing air and ocean water temperatures. In order to evaluate the strength and uniqueness of the observed increase a robust data-set on the temporal variation of calving and melt is strongly needed. The only reliable data prior to the period of aerial photographs and instrumental observations is the archive preserved at the seabed in the fjords and coastal waters off the ice sheet. Establishment of core-chronology is central in studies of these archives and is based on Pb-210 dating which will reach approx. 100 years back in time. Establishment of a detailed and accurate core-chronology by means of Pb-210 dating and Cs-137 peaks is by no means a trivial task in environments influenced by episodic deposition of ice-rafted debris (IRD). The deposition will have a relatively large component of random variability which could be mistaken for actual changes in sedimentation rate, especially so if only one or a few cores are analyzed. To increase the reliability of the calving reconstruction, a total of 13 cores have been sampled in this study in Sermilik Fjord in August 2012 at depths between approximately 700 to 900 m. Eleven of the cores are from within the central basin north of 66 degrees North and two are from the outer part of the fjord south of that line. CTD-profiles and measurements of floc size in situ indicate that the sedimentation is significantly influenced by deposition of IRD and temporal changes in sediment accumulation rates will therefore be examined for all the cores. The cores are also being analyzed for their content of dinoflagellate cysts and diatoms in order to examine possible temporal changes in ocean water temperature in the fjord. So far (August 2013) six cores have been studied and the total average accumulation rate for each year since 1925 has

  20. Floods in the Skunk River basin, Iowa

    USGS Publications Warehouse

    Heinitz, Albert J.; Wiitala, Sulo Werner

    1978-01-01

    Evaluation of flood hazards, and the planning, design, and operation of various facilities on flood plains require information on floods. This report provides information on flood stages and discharges, flood magnitudes and frequency, and flood profiles for the Skunk River and some of its tributaries. It covers the Skunk -- South Skunk Rivers to Ames, and the lower reaches of tributaries as flows: Squaw Creek, 8.2 miles; Indian Creek, 11.6 miles; North Skunk River, 83.2 miles; Cedar Creek, 55.8 miles; and Big Creek, 21.7 miles.

  1. 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.

  2. 100 Years of benthic foraminiferal history on the inner Texas shelf inferred from fauna and stable isotopes: Preliminary results from two cores

    NASA Astrophysics Data System (ADS)

    Strauss, Josiah; Grossman, Ethan L.; Carlin, Joseph A.; Dellapenna, Timothy M.

    2012-04-01

    Coastal regions, such as the Texas-Louisiana shelf, are subject to seasonal hypoxia that strongly depends on the magnitude of freshwater discharge from local and regional river systems. We have determined benthic foraminiferal fauna and isotopic compositions in two 210Pb dated box cores (BR4 and BR5) to examine the evidence for nearshore hypoxia and freshwater discharge on the Texas shelf during the last 100 years. The 210Pb chronologies of both cores reveal sedimentation rates of 0.2 and 0.1 cm yr-1, translating to ˜60 and ˜90 year records. The fauna of both cores were almost exclusively composed of Ammonia parkinsoniana and Elphidium excavatum, indicating euryhaline ambient waters. The Ammonia-Elphidium (A-E) index, a qualitative measure of low oxygen conditions, shows an increase from values between 20 and 50 to near 100 in both cores, suggesting low oxygen conditions between 1960 and the core top. Between 1950 and 1960 (9-10 cm), low A-E values in BR4 coincide with high δ18O and δ13C values greater than 0‰ and -1‰ respectively. This event corresponds to severe drought (the Texas Drought of Record) over the Brazos River drainage basin and considerably reduced river discharge from 1948 to 1957. High A-E values prior to this event imply low-oxygen conditions were prevalent prior to anthropogenic exacerbation of Louisiana shelf hypoxia and at least since the dredging of a new Brazos River delta in 1929. Elphidium excavatum δ13C values are very low (-4‰) and indicative of significant vital effect. The δ13C values of A. parkinsoniana average -3‰ and exhibit little variability, most likely reflecting pore waters influenced by aerobic and anaerobic respiration. The association of lowered Brazos River discharge with more oxygenated shelf bottom waters suggests Brazos River discharge and shelf hypoxia are linked, but the influence of Mississippi-Atchafalaya discharge can also contribute to shelf stratification.

  3. Numerical simulation of flood inundation using a well-balanced kinetic scheme for the shallow water equations with bulk recharge and discharge

    NASA Astrophysics Data System (ADS)

    Ersoy, Mehmet; Lakkis, Omar; Townsend, Philip

    2016-04-01

    The flow of water in rivers and oceans can, under general assumptions, be efficiently modelled using Saint-Venant's shallow water system of equations (SWE). SWE is a hyperbolic system of conservation laws (HSCL) which can be derived from a starting point of incompressible Navier-Stokes. A common difficulty in the numerical simulation of HSCLs is the conservation of physical entropy. Work by Audusse, Bristeau, Perthame (2000) and Perthame, Simeoni (2001), proposed numerical SWE solvers known as kinetic schemes (KSs), which can be shown to have desirable entropy-consistent properties, and are thus called well-balanced schemes. A KS is derived from kinetic equations that can be integrated into the SWE. In flood risk assessment models the SWE must be coupled with other equations describing interacting meteorological and hydrogeological phenomena such as rain and groundwater flows. The SWE must therefore be appropriately modified to accommodate source and sink terms, so kinetic schemes are no longer valid. While modifications of SWE in this direction have been recently proposed, e.g., Delestre (2010), we depart from the extant literature by proposing a novel model that is "entropy-consistent" and naturally extends the SWE by respecting its kinetic formulation connections. This allows us to derive a system of partial differential equations modelling flow of a one-dimensional river with both a precipitation term and a groundwater flow model to account for potential infiltration and recharge. We exhibit numerical simulations of the corresponding kinetic schemes. These simulations can be applied to both real world flood prediction and the tackling of wider issues on how climate and societal change are affecting flood risk.

  4. Quantification of uncertainties in the 100-year flow at an ungaged site near a gaged station and its application in Georgia

    NASA Astrophysics Data System (ADS)

    Cho, Huidae; Bones, Emma

    2016-08-01

    The Federal Emergency Management Agency has introduced the concept of the "1-percent plus" flow to incorporate various uncertainties in estimation of the 100-year or 1-percent flow. However, to the best of the authors' knowledge, no clear directions for calculating the 1-percent plus flow have been defined in the literature. Although information about standard errors of estimation and prediction is provided along with the regression equations that are often used to estimate the 1-percent flow at ungaged sites, uncertainty estimation becomes more complicated when there is a nearby gaged station because regression flows and the peak flow estimate from a gage analysis should be weighted to compute the weighted estimate of the 1-percent flow. In this study, an equation for calculating the 1-percent plus flow at an ungaged site near a gaged station is analytically derived. Also, a detailed process is introduced for calculating the 1-percent plus flow for an ungaged site near a gaged station in Georgia as an example and a case study is performed. This study provides engineers and practitioners with a method that helps them better assess flood risks and develop mitigation plans accordingly.

  5. Sediment records of environmental changes in the south end of the Zhejiang-Fujian coastal mud area during the past 100 years

    NASA Astrophysics Data System (ADS)

    Wang, Linmiao; Li, Guangxue; Gao, Fei; Liu, Ling; Liu, Yong; Dada, Olusegun A.

    2014-07-01

    Previous studies carried out in the East China Sea (ECS) mud area focused on long-term environmental changes in sedimentary records during the Holocene, especially during the mid-Holocene high-stand water levels period. These results indicate that sensitive grain size groups can be used as a sedimentary proxy to reconstruct the evolution of the East Asian Winter Monsoon (EAWM). The studies have been carried out mainly in the northern and middle portions of the Zhejiang-Fujian coastal mud, however, similar research in the southern portion and the comparison between sedimentary proxy and modern measured data of EAWM are lacking. In this paper, we focused on a sedimentary record of the past 100 years with an enhanced resolution of 1.8 years. Investigations of the southern end of the Zhejiang-Fujian coastal mud area were conducted on the basis of 210Pb chronology, grain-size analysis and chemical element analysis. The correspondence between the mean grain size (Mz) of sediment sensitive grain size and the measured EAWM was confi rmed for the fi rst time. We found that during the recent 100 years, the variation of the mean grain size of the sensitive population in the southern portion of the Zhejiang-Fujian mud was mainly controlled by the EAWM intensity changes; and not directly related to changes in the sediment discharge from Datong station of the Changjiang River (DTSD). Finally, recent changes in the content of heavy metals in study area refl ect the impact of human activities on the environment.

  6. Managing Floods and Resources at the Arroyo Las Positas

    SciTech Connect

    Sanchez, L; Van Hattem, M; Mathews, S

    2002-03-05

    Engineers and water resource professionals are challenged with protecting facilities from flood events within environmental resource protection, regulatory, and economic constraints. One case in point is the Arroyo Las Positas (ALP), an intermittent stream that traverses the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. Increased runoff from post-drought rainfall, upstream development, and new perennial discharges from LLNL activities have resulted in increased dry weather flows and wetland vegetation. These new conditions have recently begun to provide improved habitat for the federally threatened California red-legged frog (Rana aurora draytonii; CRLF), but the additional vegetation diminishes the channel's drainage capacity and increases flood risk. When LLNL proposed to re-grade the channel to reestablish the 100-year flood capacity, traditional dredging practices were no longer being advocated by environmental regulatory agencies. LLNL therefore designed a desilting maintenance plan to protect LLNL facility areas from flooding, while minimizing impacts to wetland resources and habitat. The result was a combination of structural upland improvements and the ALP Five Year Maintenance Plan (Maintenance Plan), which includes phased desilting in segments so that the entire ALP is desilted after five years. A unique feature of the Maintenance Plan is the variable length of the segments designed to minimize LLNL's impact on CRLF movement. State and federal permits also added monitoring requirements and additional constraints on desilting activities. Two years into the Maintenance Plan, LLNL is examining the lessons learned on the cost-effectiveness of these maintenance measures and restrictions and reevaluating the direction of future maintenance activities.

  7. A flood-flow formula for Connecticut

    USGS Publications Warehouse

    Bigwood, B.L.; Thomas, M.P.

    1955-01-01

    A study of the frequency and magnitude of floods within the Connecticut area is contained in this report. Annual flood discharges for 44 stream-gaging stations whose records range in length from l0 to 40 years are presented and a regional flood-frequency relationship developed based upon the ratios of all floods to the mean annual flood at each of these locations. Definition of this curve for floods of larger recurrence intervals is based upon historical studies of extraordinary floods which have occurred within the area. For ungaged areas, the mean annual flood value may be determined by use of a flood-flow formula based upon the topographic characteristics of drainage area and basin slope. The development of this formula also is included.

  8. Zonation of flood production potential in Kabutar Ali Chai watershed using SCS model

    NASA Astrophysics Data System (ADS)

    Jananeh, Keristineh

    2015-04-01

    watershed were estimated experimentally using the SCS method, based on which, A3 and A4 sub-basins have the highest peak discharge (15.55 and 19.44, respectively), which can be one of the flood production factors in this watershed. Meanwhile, the A1 sub-basin in the southern end of the watershed has the lowest peak discharge with low flood production potential. Finally, considering the runoff height and discharge, as well as the determined CN number, the flood production potential was calculated for 2, 5, 10, 25, 50 and 100 year return periods. According to the these flood-potential maps, A3 sub-basin shows high flood risk in its northern, central and southern parts. A2 and A4 sub-basins have lower flood risk, respectively, and the A1 sub-basin shows the lowest flood potential, which is due to the presence of permeable alluvial sediments and the widening of the stream bed. It was also revealed that the land slope is not the sole effective factor in flood production, but lithology and vegetation are also efficient.

  9. Green-blue water in the city: quantification of impact of source control versus end-of-pipe solutions on sewer and river floods.

    PubMed

    De Vleeschauwer, K; Weustenraad, J; Nolf, C; Wolfs, V; De Meulder, B; Shannon, K; Willems, P

    2014-01-01

    Urbanization and climate change trends put strong pressures on urban water systems. Temporal variations in rainfall, runoff and water availability increase, and need to be compensated for by innovative adaptation strategies. One of these is stormwater retention and infiltration in open and/or green spaces in the city (blue-green water integration). This study evaluated the efficiency of three adaptation strategies for the city of Turnhout in Belgium, namely source control as a result of blue-green water integration, retention basins located downstream of the stormwater sewers, and end-of-pipe solutions based on river flood control reservoirs. The efficiency of these options is quantified by the reduction in sewer and river flood frequencies and volumes, and sewer overflow volumes. This is done by means of long-term simulations (100-year rainfall simulations) using an integrated conceptual sewer-river model calibrated to full hydrodynamic sewer and river models. Results show that combining open, green zones in the city with stormwater retention and infiltration for only 1% of the total city runoff area would lead to a 30 to 50% reduction in sewer flood volumes for return periods in the range 10-100 years. This is due to the additional surface storage and infiltration and consequent reduction in urban runoff. However, the impact of this source control option on downstream river floods is limited. Stormwater retention downstream of the sewer system gives a strong reduction in peak discharges to the receiving river. However due to the difference in response time between the sewer and river systems, this does not lead to a strong reduction in river flood frequency. The paper shows the importance of improving the interface between urban design and water management, and between sewer and river flood management. PMID:25500472

  10. 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.

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

    USGS Publications Warehouse

    Gamble, Charles R.

    1983-01-01

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

  12. Pakistan Flooding

    Atmospheric Science Data Center

    2013-04-16

    article title:  Flooding in Pakistan     View Larger Image In late July 2010, flooding caused by heavy monsoon rains began in several regions of Pakistan, ... river is 23 kilometers (14 miles) wide or more in spots, and flooding in much of the surrounding region, particularly in the Larkana ...

  13. 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

  14. Reconstructing the discharges and geomorphological impacts of artificial floods using archives and field surveys. The case of timber floating in the Yonne Basin, France (16th - 19th centuries).

    NASA Astrophysics Data System (ADS)

    Gob, Frederic; Anne-Sophie, Poux; Nicolas, Jacob

    2010-05-01

    Timber floating became a major industry in the Yonne basin between the 16th and 19th centuries due to the rapid growth of Paris and its increasing energy needs. The Yonne River is a tributary of the Seine basin. Its source is located in the Morvan region, a granitic small massif in the south eastern part of the basin. Logs were transported by floating from the production area in the upper valley to Paris through the Yonne and the Seine rivers. In order to ease log transport in the steep and narrow headwater streams, river channels were reshaped and artificial floods were regularly created from small reservoirs obstructing the very top of the valley. The extent and the duration of the timber floating industry led to major geomorphological, hydrological and ecological perturbations to the river system. In order to study the impacts of this industry we tried to reconstruct the artificial conditions of flow during the floating period using archives and field surveys. The reservoirs were located and dated using archives and historical maps in order to evaluate the modifications to the hydrological regime. At the end of the 18th century, reservoirs were present on every little tributary of the upper valley. Their volumes were reconstructed based on the areas of the reservoirs and the heights of their dykes. From historical data, we know that it only took a couple of hours to empty the reservoirs and a couple of days to fill them. Over decades, between November and February the reservoirs were emptied as often as possible (probably several times per week). Small steep and incised streams of no more than 5 m wide regularly experienced discharges of 2 to 3 m3/s on average. The energy associated with the discharges in these small streams is very high: stream powers range between 250 and 400 W/m². In such conditions, the streams should have been able to transport pebbles and boulders of 15 to 35 cm in diameter and therefore induce very high sediment transport rates. Further

  15. Secretin, 100 years later.

    PubMed

    Chey, William Y; Chang, Ta-Min

    2003-01-01

    One hundred years have elapsed since the discovery of secretin by Bayliss and Starling in 1902. In the past century, the research of secretin has gone by many milestones including isolation, purification and structural determination, chemical synthesis, establishment of its hormonal status by radioimmunoassay and immunoneutralization, identification of the specific receptor, cloning of secretin and its receptor, and identification of a secretin-releasing peptide. It has become clear that secretin is a hormone-regulating pancreatic exocrine secretion of fluid and bicarbonate, gastric acid secretion, and gastric motility. The release and actions of secretin is regulated by hormone-hormonal and neurohormonal interactions. The vagus nerve, particularly its afferent pathway, plays an essential role in the physiological actions of secretin. Substantial information about the property of the secretin receptor has been accumulated, but a potent secretin receptor-specific antagonist remains to be formulated. The neural regulatory mechanisms of the release and action of secretin await further elucidation. The physiological role of secretin in intestinal secretions and motility and extragastrointestinal organs remains to be defined. The presence of secretin and its receptor in the central nervous system is well documented, but its function as a neuropeptide has been recognized gradually and requires extensive study in the future. PMID:14673718

  16. Physics in 100 years

    NASA Astrophysics Data System (ADS)

    Wilczek, Frank

    2016-04-01

    Here I indulge in wide-ranging speculations on the shape of physics, and technology closely related to physics, over the next one hundred years. Themes include the many faces of unification, the re-imagining of quantum theory, and new forms of engineering on small, intermediate, and large scales.

  17. 100 Years of Science

    SciTech Connect

    Carrigan, Dick

    2004-07-07

    The last half-century has seen enormous strides in many scientific and technical areas. In fundamental physics previously unrelated fields like weak interactions and electromagnetism have been linked. Cosmology has been probed back to the Big Bang. Computing and communications have moved from minor topics to subjects that dominate the economy. The structure of DNA has been untangled. We may be on the threshold of understanding the origin of life and even discovering life elsewhere in the universe. Several of these diverse topics such as cosmology and fundamental physics are already profoundly coupled. Remarkably, ties exist between all of these subjects. These ties will be reviewed in light of opportunities ahead in the next decades.

  18. 100 Years of Mathematics.

    ERIC Educational Resources Information Center

    Atiyah, Michael

    2000-01-01

    The 20th century was a period of extraordinary expansion and progress in mathematics. Concentrates on a few key themes that can be discerned such as local to global, increase in dimension, commutative to non-commutative, linear to non-linear, and homology theory, although it is impossible to list all the main achievements. (ASK)

  19. Interconnected ponds operation for flood hazard distribution

    NASA Astrophysics Data System (ADS)

    Putra, S. S.; Ridwan, B. W.

    2016-05-01

    The climatic anomaly, which comes with extreme rainfall, will increase the flood hazard in an area within a short period of time. The river capacity in discharging the flood is not continuous along the river stretch and sensitive to the flood peak. This paper contains the alternatives on how to locate the flood retention pond that are physically feasible to reduce the flood peak. The flood ponds were designed based on flood curve number criteria (TR-55, USDA) with the aim of rapid flood peak capturing and gradual flood retuning back to the river. As a case study, the hydrologic condition of upper Ciliwung river basin with several presumed flood pond locations was conceptually designed. A fundamental tank model that reproducing the operation of interconnected ponds was elaborated to achieve the designed flood discharge that will flows to the downstream area. The flood hazard distribution status, as the model performance criteria, will be computed within Ciliwung river reach in Manggarai Sluice Gate spot. The predicted hazard reduction with the operation of the interconnected retention area result had been bench marked with the normal flow condition.

  20. A water and sediment budget for the lower Mississippi-Atchafalaya River in flood years 2008-2010: Implications for sediment discharge to the oceans and coastal restoration in Louisiana

    NASA Astrophysics Data System (ADS)

    Allison, Mead A.; Demas, Charles R.; Ebersole, Bruce A.; Kleiss, Barbara A.; Little, Charles D.; Meselhe, Ehab A.; Powell, Nancy J.; Pratt, Thad C.; Vosburg, Brian M.

    2012-04-01

    SummaryThe Mississippi is the largest riverine system in North America and one of the most engineered rivers in the world. The challenges of studying the Mississippi River are due to its complex sediment-water dynamics and the multi (and often competing) uses for its resources. Flood control and navigation are primary factors that control how the river is managed. A third factor is the use of river resources, namely water and sediment, for nourishing the degrading coastal wetlands of the states of Louisiana and Mississippi. As such, these factors must be fully considered and coordinated while investigating and developing techniques to harness the sediment resources of the River for coastal restoration. This paper presents a detailed suspended sediment budget analysis for the lowermost Mississippi and Atchafalaya River systems for the flood years of 2008, 2009, and 2010. Data were derived mainly from Federal and State of Louisiana measurements of water discharge and suspended sediment load at (1) monitoring stations along the river channel and (2) boat-based measurements made during specific project studies at natural passes and man-made channel diversions. The present study was focused on flood years 2008-2010 to (1) minimize the influence on the budgets of a historical decline in sediment loads carried by the river as observed by previous investigators and (2) take advantage of recent improvements in the monitoring network. The results show that both the Mississippi and Atchafalaya distributary pathways were efficient at sequestering suspended sediments, particularly the larger (sand) size fraction. Approximately 44% of the total Mississippi + Red River suspended load (80% of the sand) reaching Old River Control structures split between the distributaries was sequestered upstream of the Gulf of Mexico by overbank storage and channel bed aggradation. Increases in bed aggradation in the Mississippi distributary are linked to a loss of stream power associated with

  1. Effect of Detention Basin Release Rates on Flood Flows - Application of a Model to the Blackberry Creek Watershed in Kane County, Illinois

    USGS Publications Warehouse

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

    2009-01-01

    The effects of stormwater detention basins with specified release rates are examined on the watershed scale with a Hydrological Simulation Program - FORTRAN (HSPF) continuous-simulation model. Modeling procedures for specifying release rates from detention basins with orifice and weir discharge configurations are discussed in this report. To facilitate future detention modeling as a tool for watershed management, a chart relating watershed impervious area to detention volume is presented. The report also presents a case study of the Blackberry Creek watershed in Kane County, Ill., a rapidly urbanizing area seeking to avoid future flood damages from increased urbanization, to illustrate the effects of various detention basin release rates on flood peaks and volumes and flood frequencies. The case study compares flows simulated with a 1996 land-use HSPF model to those simulated with four different 2020 projected land-use HSPF model scenarios - no detention, and detention basins with release rates of 0.08, 0.10, and 0.12 cubic feet per second per acre (ft3/s-acre), respectively. Results of the simulations for 15 locations, which included the downstream ends of all tributaries and various locations along the main stem, showed that a release rate of 0.10 ft3/s-acre, in general, can maintain postdevelopment 100-year peak-flood discharge at a similar magnitude to that of 1996 land-use conditions. Although the release rate is designed to reduce the 100-year peak flow, reduction of the 2-year peak flow is also achieved for a smaller proportion of the peak. Results also showed that the 0.10 ft3/s-acre release rate was less effective in watersheds with relatively high percentages of preexisting (1996) development than in watersheds with less preexisting development.

  2. Floods in the English River basin, Iowa

    USGS Publications Warehouse

    Heinitz, A.J.; Riddle, D.E.

    1981-01-01

    Information describing floods is essential for proper planning, design, and operation of bridges and other structures on or over streams and their flood plains. This report provides information on flood stages and discharges, flood magnitude and frequency, bench mark data, and flood profiles for the English River and some of its tributaries. It covers the English River, the North English River to near Guernsey, the south Eaglish River to Barnes City and the lower reaches of the Biddle English and Deep Rivers

  3. Urban sprawl and flooding in southern California

    USGS Publications Warehouse

    Rantz, S.E.

    1970-01-01

    The floods of January 1969 in south-coastal California provide a timely example of the effect of urban sprawl on flood damage. Despite recordbreaking, or near recordbreaking, stream discharges, damage was minimal in the older developed areas that are protected against inundation and debris damage by carefully planned flood-control facilities, including debris basins and flood-conveyance channels. By contrast, heavy damage occurred in areas of more recent urban sprawl, where the hazards of inundation and debris or landslide damage have not been taken into consideration, and where the improvement and development of drainage or flood-control facilities have not kept pace with expanding urbanization.

  4. Estimation of the Probable Maximum Flood for a Small Lowland River in Poland

    NASA Astrophysics Data System (ADS)

    Banasik, K.; Hejduk, L.

    2009-04-01

    The planning, designe and use of hydrotechnical structures often requires the assesment of maximu flood potentials. The most common term applied to this upper limit of flooding is the probable maximum flood (PMF). The PMP/UH (probable maximum precipitation/unit hydrograph) method has been used in the study to predict PMF from a small agricultural lowland river basin of Zagozdzonka (left tributary of Vistula river) in Poland. The river basin, located about 100 km south of Warsaw, with an area - upstream the gauge of Plachty - of 82 km2, has been investigated by Department of Water Engineering and Environmenal Restoration of Warsaw University of Life Sciences - SGGW since 1962. Over 40-year flow record was used in previous investigation for predicting T-year flood discharge (Banasik et al., 2003). The objective here was to estimate the PMF using the PMP/UH method and to compare the results with the 100-year flood. A new relation of depth-duration curve of PMP for the local climatic condition has been developed based on Polish maximum observed rainfall data (Ozga-Zielinska & Ozga-Zielinski, 2003). Exponential formula, with the value of exponent of 0.47, i.e. close to the exponent in formula for world PMP and also in the formula of PMP for Great Britain (Wilson, 1993), gives the rainfall depth about 40% lower than the Wilson's one. The effective rainfall (runoff volume) has been estimated from the PMP of various duration using the CN-method (USDA-SCS, 1986). The CN value as well as parameters of the IUH model (Nash, 1957) have been established from the 27 rainfall-runoff events, recorded in the river basin in the period 1980-2004. Varibility of the parameter values with the size of the events will be discussed in the paper. The results of the analyse have shown that the peak discharge of the PMF is 4.5 times larger then 100-year flood, and volume ratio of the respective direct hydrographs caused by rainfall events of critical duration is 4.0. References 1.Banasik K

  5. Estimation of the Probable Maximum Flood for a Small Lowland River in Poland

    NASA Astrophysics Data System (ADS)

    Banasik, K.; Hejduk, L.

    2009-04-01

    The planning, designe and use of hydrotechnical structures often requires the assesment of maximu flood potentials. The most common term applied to this upper limit of flooding is the probable maximum flood (PMF). The PMP/UH (probable maximum precipitation/unit hydrograph) method has been used in the study to predict PMF from a small agricultural lowland river basin of Zagozdzonka (left tributary of Vistula river) in Poland. The river basin, located about 100 km south of Warsaw, with an area - upstream the gauge of Plachty - of 82 km2, has been investigated by Department of Water Engineering and Environmenal Restoration of Warsaw University of Life Sciences - SGGW since 1962. Over 40-year flow record was used in previous investigation for predicting T-year flood discharge (Banasik et al., 2003). The objective here was to estimate the PMF using the PMP/UH method and to compare the results with the 100-year flood. A new relation of depth-duration curve of PMP for the local climatic condition has been developed based on Polish maximum observed rainfall data (Ozga-Zielinska & Ozga-Zielinski, 2003). Exponential formula, with the value of exponent of 0.47, i.e. close to the exponent in formula for world PMP and also in the formula of PMP for Great Britain (Wilson, 1993), gives the rainfall depth about 40% lower than the Wilson's one. The effective rainfall (runoff volume) has been estimated from the PMP of various duration using the CN-method (USDA-SCS, 1986). The CN value as well as parameters of the IUH model (Nash, 1957) have been established from the 27 rainfall-runoff events, recorded in the river basin in the period 1980-2004. Varibility of the parameter values with the size of the events will be discussed in the paper. The results of the analyse have shown that the peak discharge of the PMF is 4.5 times larger then 100-year flood, and volume ratio of the respective direct hydrographs caused by rainfall events of critical duration is 4.0. References 1.Banasik K

  6. Lung surgery - discharge

    MedlinePlus

    Thoracotomy - discharge; Lung tissue removal - discharge; Pneumonectomy - discharge; Lobectomy - discharge; Lung biopsy - discharge; Thoracoscopy - discharge; Video-assisted thoracoscopic surgery - discharge; VATS - discharge; Thoracoscopy - discharge

  7. The 1916 catastrophic flood following the Bílá Desná dam failure: The role of historical data sources in the reconstruction of its geomorphologic and landscape effects

    NASA Astrophysics Data System (ADS)

    Raška, Pavel; Emmer, Adam

    2014-12-01

    This paper describes the reconstruction of the geomorphologic and landscape effects of the most catastrophic flood owing to dam failure within the territory of today's Czech Republic, namely, the Bílá Desná dam failure of 1916. Because of the realisation of the significant later transformation of the Bílá Desná river catchment almost 100 years after the flood event, the field research performed during the summer and fall of 2013 had to be supported by extensive research in regional archives for documentary data. Various data types and sources (such as court investigation notes, investigation reports for insurance companies, old maps, and old photos, as well as video and recorded testimonies of survivors) were used to reconstruct the magnitude (discharge, flood wave extent) of the flood and its effects on the channel morphology and landscape. According to the reconstruction of the dam failure, which was caused by the internal erosion of the dam, the calculated peak discharge ranged between 418.2 and 1491.7 m3s- 1 and therefore exceeded the mean flow rate of the Bílá Desná River by more than 850 times. The river channel immediately upstream and downstream of the dam reclaimed its former meandering pattern with higher sinuosity, and new gravel point bars and irregular bars have been formed. Moreover, the river channel immediately below the dam shifted by up to 30 m following the flood wave. The most significant flood impacts were apparent in the village of Desná, where the flood wave, together with transported boulders (up to 2 m in diametre) and logs from sawmills situated upstream, killed 62 inhabitants and damaged or destroyed 101 buildings. The reconstructed flood wave in the towns of Desná and Tanvald exceeded the bankfull water level twice, with a width ranging between ~ 50 and 250 m in contrast to the average channel width of a few metres.

  8. Spatio-temporal analysis of rainfall trends over a maritime state (Kerala) of India during the last 100 years

    NASA Astrophysics Data System (ADS)

    Nair, Archana; Ajith Joseph, K.; Nair, K. S.

    2014-05-01

    Kerala, a maritime state of India is bestowed with abundant rainfall which is about three times the national average. This study is conducted to have a better understanding of rainfall variability and trend at regional level for this state during the last 100 years. It is found that the rainfall variation in northern and southern regions of Kerala is large and the deviation is on different timescales. There is a shifting of rainfall mean and variability during the seasons. The trend analysis on rainfall data over the last 100 years reveals that there is a significant (99%) decreasing trend in most of the regions of Kerala especially in the month of January, July and November. The annual and seasonal trends of rainfall in most regions of Kerala are also found to be decreasing significantly. This decreasing trend may be related to global anomalies as a result of anthropogenic green house gas (GHG) emissions due to increased fossil fuel use, land-use change due to urbanisation and deforestation, proliferation in transportation associated atmospheric pollutants. We have also conducted a study of the seasonality index (SI) and found that only one district in the northern region (Kasaragod) has seasonality index of more than 1 and that the distribution of monthly rainfall in this district is mostly attributed to 1 or 2 months. In rest of the districts, the rainfall is markedly seasonal. The trend in SI reveals that the rainfall distribution in these districts has become asymmetric with changes in rainfall distribution.

  9. Over 100 years of environmental change recorded by foraminifers and sediments in Mobile Bay, Alabama, Gulf of Mexico, USA

    NASA Astrophysics Data System (ADS)

    Osterman, Lisa E.; Smith, Christopher G.

    2012-12-01

    The marine microfauna of Mobile Bay has been profoundly influenced by the development and expansion of the primary shipping channel over the last ˜100 years. Foraminifers and sediments from seven box cores with excess lead-210 chronology document that channel dredging and spoil disposal have altered circulation, reduced estuarine mixing, changed sedimentation patterns, and caused a faunal turnover within the bay. Beginning in the late 1800s, changes in estuarine mixing allowed for greater low-pH freshwater influence in the bay, and ultimately began environmental changes that resulted in the loss of calcareous foraminifers. By the early 1900s, box cores throughout Mobile Bay record a ˜100-year trend of increasing calcareous test dissolution that continues to the present. Since the completion of the current shipping channel in the 1950s, restricted tidal flushing and increased terrestrial organic matter, documented by carbon-to-nitrogen ratios, stimulated an increase in agglutinated foraminiferal densities. However, in deeper areas of the bay, hypoxic water has negatively impacted the marine microfauna. Comparisons of the present-day foraminiferal assemblage with foraminifers collected in the early 1970s indicate that the continued biologic loss of calcareous foraminifers in the bay has allowed the introduction of a new agglutinated foraminiferal species into the bay.

  10. Flood of March 1997 in southern Ohio

    USGS Publications Warehouse

    Jackson, K.S.; Vivian, S.A.; Diam, F.J.; Crecelius, C.J.

    1997-01-01

    Rainfall amounts of up to 12 inches produced by thunderstorms during March 1-2, 1997 resulted in severe flooding throughout much of southern Ohio. Eighteen counties were declared Federal and State disaster areas. Cost estimates of damage in Ohio from the flooding are nearly $180 million. About 6,500 residences and more than 800 businesses were affected by flooding. Nearly 20,000 persons were evacuated, and 5 deaths were attributed to the flooding. Record peak stage and streamflow were recorded at U.S. Geological Survey (USGS) streamflow-gaging stations on Ohio Brush Creek near West Union and Shade River near Chester. The peak streamflow at these two locations exceeded the estimate of the 100-year-recurrence- interval peak streamflow. The recurrence intervals of peak stream flow at selected USGS streamflow gaging stations throughout southern Ohio ranged from less than 2 years to greater than 100 years. The most severe flooding in the State was generally confined to areas within 50 to 70 miles of the Ohio River. Many communities along the Ohio River experienced the worst flooding in more than 30 years.

  11. Storm and flood of July 31-August 1, 1976, in the Big Thompson River and Cache la Poudre River basins, Larimer and Weld Counties, Colorado

    USGS Publications Warehouse

    McCain, Jerald F.; Shroba, R.R.

    1979-01-01

    the site during 88 years of flood history. At the gaging station on the North Fork Big Thompson River at Drake, the peak discharge on July 31 was 8,710 cubic feet per second as compared to the previous maximum discharge during 29 years of record of 1,290 cubic feet per second. Peak discharges for three small tributaries near the area of heaviest rainfall northeast of Estes Park exceeded previously recorded maximum discharges for basins of less than 4 square miles in Colorado. Stream velocities were rapid along the tributaries near the storm center and on the Big Thompson River in the canyon section, with average velocities of 20-25 feet per second being common. The flood crest on the Big Thompson River moved through the 7.7-mile reach between Drake and the canyon mouth in about 30 minutes for an average travel rate of 15 miles per hour, or about 23 feet per second. The peak discharge of the flood on the Big Thompson River at the canyon mouth exceeded the 100-year flood discharge for the site by a ratio of 1.8. Upstream in the Big Thompson River basin, the flood was even more rare being 3.8 times the estimated 100-year flood discharge at the site on the Big Thompson River just upstream from Drake. In the Cache la Poudre River basin, recurrence intervals were computed to be 100 years for the flood on Deadman Creek and 16 years for Rist Canyon and the Cache la Poudre River at the canyon mouth near Fort Collins. Although the rainfall and flood discharges were unusually large, they are not unprecedented for some areas along the eastern foothills and plains of Colorado. The May 1935 and June 1965 floods on some streams along the eastern plains greatly exceeded the 1976 flood peaks in the storm area. Prior floods on several other streams in the foothills have approximately equaled the 1976 peak discharges. PART B: Intense rainfall from the Big Thompson thunderstorm complex on the evening of July 31,1976, and the ensuing floods that evening and the fol

  12. Annual exceedance probabilities of the peak discharges of 2011 at streamgages in Vermont and selected streamgages in New Hampshire, western Massachusetts, and northeastern New York

    USGS Publications Warehouse

    Olson, Scott A.; Bent, Gardner C.

    2013-01-01

    The U.S. Geological Survey, in cooperation with the Federal Emergency Management Agency, determined annual exceedance probabilities for peak discharges occurring during the 2011 water year (October 1 to September 30) at streamgages in Vermont and selected streamgages in New Hampshire, western Massachusetts, and northeastern New York. This report presents the 2011 water year peak discharges at 145 streamgages in the study area and provides the results of the analyses of the 50-, 20-, 10-, 4-, 2-, 1-, and 0.2-percent annual exceedance probability discharges at 135 of the 145 streamgages. The annual exceedance probabilities for the 2011 water year peak discharges also are presented. Snowmelt and near record rainfall led to flooding across northern Vermont on April 27 and 28, 2011. At three streamgages with more than 10 years of record, the April rain event resulted in the peak discharge of record. At seven streamgages, the peak discharge resulting from this event had an annual exceedance probability less than or equal to 1 percent. In early May 2011, new peak stage records were set at two Lake Champlain gages with more than 100 years of record. At the Lake Champlain at Burlington, Vermont, gage, the water surface reached 102.79 feet (ft) (North American Vertical Datum of 1988 (NAVD 88)) on May 6, 2011, and at the Richelieu River (Lake Champlain) at Rouses Point, New York, gage, the water surface reached 102.75 ft NAVD 88. Record-breaking rainfall in late May produced additional flooding across northern Vermont on May 26 and 27, 2011. Four streamgages in northwestern Vermont recorded peak-of-record discharges as a result of this flooding. At three streamgages, the peak discharges from this event had an annual exceedance probability less than or equal to 1 percent. From August 28 to 29, 2011, Tropical Storm Irene delivered rainfall totals ranging from about 3 to more than 10 inches, which resulted in extensive flooding and new period-of-record peak discharges at 37

  13. 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.

  14. Flood profiles for Cypress Creek, west-central Florida

    USGS Publications Warehouse

    Murphy, W.R., Jr.

    1978-01-01

    Flood profiles are included for selected recurrence-interval floods in west-central Florida for a 27-mile reach of Cypress Creek, for a 4-mile tributary reach, and for a 1.2-mile distributary reach. The procedure for constructing flood profiles is based on flood heights computed in a step-backwater analysis using the following data: 2-, 2.33-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year flood-peak discharges; data for 53 Cypress Creek channel cross sections, 11 tributary cross sections, and 7 distributary cross sections (including roughness coefficients); and stage-discharge relations. Computed flood heights are judged to be generally accurate to plus-or-minus 0.5 foot. Flood data presented can be used to delineate areal extent of flooding on topographic maps. This information can be used by local governmental agencies to control flood-plain development. (Woodard-USGS)

  15. A uniform technique for flood frequency analysis.

    USGS Publications Warehouse

    Thomas, W.O., Jr.

    1985-01-01

    This uniform technique consisted of fitting the logarithms of annual peak discharges to a Pearson Type III distribution using the method of moments. The objective was to adopt a consistent approach for the estimation of floodflow frequencies that could be used in computing average annual flood losses for project evaluation. In addition, a consistent approach was needed for defining equitable flood-hazard zones as part of the National Flood Insurance Program. -from ASCE Publications Information

  16. Modeling Flood Plain Hydrology and Forest Productivity of Congaree Swamp, South Carolina

    USGS Publications Warehouse

    Doyle, Thomas W.

    2009-01-01

    tupelo (Nyssa aquatica), green ash (Fraxinus pennslyvanica), laurel oak (Quercus laurifolia), swamp chestnut oak (Quercus michauxii), and sycamore (Plantanus occidentalis) within Congaree Swamp in highand low-elevation sites characteristic of shorter and longer flood duration and related to upriver flood controls and dam operation. Ring counts and dating indicated that all loblolly pine trees and nearly all baldcypress collections in this study are postsettlement recruits and old-growth cohorts, dating from 100 to 300 years in age. Most hardwood species and trees cored for age analysis were less than 100 years old, demonstrating robust growth and high site quality. Growth chronologies of loblolly pine and baldcypress exhibited positive and negative inflections over the last century that corresponded with climate history and residual effects of Hurricane Hugo in 1989. Stemwood production on average was less for trees and species on sites with longer flood retention and hydroperiod affected more by groundwater seepage and site elevation than river floods. Water level data provided evidence that stream regulation and operations of the Saluda Dam (post-1934) have actually increased the average daily water stage in the Congaree River. There was no difference in tree growth response by species or hydrogeomorphic setting to predam and postdam flood conditions and river stage. Climate-growth analysis showed that long-term growth variation is controlled more by spring/ summer temperatures in loblolly pine and by spring/summer precipitation in baldcypress than flooding history.

  17. Flood of September 7-9, 1987, in Lexington and Richland counties in the vicinity of Saint Andrews Road and Irmo, South Carolina

    USGS Publications Warehouse

    Guimaraes, W.B.

    1989-01-01

    Localized heavy rainfall on September 7, 1987, in Lexington and Richland Counties, South Carolina, caused severe flooding in the basins of Kinley Creek, Rawls Creek, and Stoop Creek, in the vicinity of Saint Andrews Road and the town of Irmo, South Carolina. The flooding damaged homes, furnishings, and landscaping. Rainfall, peak discharges, high-water elevations, and frequency relations of rainfall and discharge are tabulated and plotted for selected streams. The rain was most intense in the area along Rawls Creek, R-2 (tributary to Rawls Creek), Koon Branch (tributary to Rawls Creek), and the upper part of Kinley Creek. A rainfall of about 5.5 inches in 3 hours, which has a recurrence interval in excess of 100 years, was reported by local residents along these streams. High-water marks are presented in this report for Stoop Creek, Kinley Creek, K-1 (tributary to Kinley Creek), K-2 (tributary to Kinley Creek), unnamed tributary to Kinley Creek, Lowery Creek (tributary to Kinley Creek), Rawls Creek, R-2 (tributary to Rawls Creek), and Koon Branch (tributary to Rawls Creek). Peak discharges at the most downstream sites on Rawls Creek and Koon Branch had recurrence intervals of 75 years and 60 years, respectively. Peak discharges on Kinley Creek varied from 20 to 25 years north of K-1 basin to less than 10 years at K-1. The Stoop Creek basin had a recurrence interval of 10 years. (USGS)

  18. 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…

  19. Are Geodetically and Geologically Constrained Vertical Deformation Models Compatible With the 100-Year Coastal Tide Gauge Record in California?

    NASA Astrophysics Data System (ADS)

    Smith-Konter, B. R.; Sandwell, D. T.

    2006-12-01

    Sea level change has been continuously recorded along the California coastline at several tide gauge stations for the past 50-100 years. These stations provide a temporal record of sea level change, generally attributed to post-glacial rebound and ocean climate phenomena. However, geological processes, including displacements from large earthquakes, have also been shown to produce sea level variations. Furthermore, the vertical tectonic response to interseismic strain accumulation in regions of major fault bends has been shown to produce uplift and subsidence rates consistent with sea level trends. To investigate the long-term extent and implication of tectonic deformation on sea level change, we compare time series data from California tide gauge stations to model estimates of vertical displacements produced by earthquake cycle deformation. Using a 3-D semi-analytic viscoelastic model, we combine geologic slip rates, geodetic velocities, and historical seismic data to simulate both horizontal and vertical deformation of the San Andreas Fault System. Using this model, we generate a time-series of vertical displacements spanning the 100-year sea level record and compare this to tide gauge data provided by the Permanent Service for Mean Sea Level (PSMSL). Comparison between sea level data and a variety of geologically and geodetically constrained models confirms that the two are highly compatible. Vertical displacements are largely controlled by interseismic strain accumulation, however displacements from major earthquakes are also required to explain varying trends in the sea level data. Models based on elastic plate thicknesses of 30-50km and viscosities of 7x10^1^8-2x10^1^9 Pa-s produce vertical displacements at tide-gauge locations that explain long-term trends in the sea level record to a high degree of accuracy at nearly all stations. However, unmodeled phenomena are also present in the sea level data and require further inspection.

  20. Kidney stones - lithotripsy - discharge

    MedlinePlus

    Extracorporeal shock wave lithotripsy - discharge; Shock wave lithotripsy - discharge; Laser lithotripsy - discharge; Percutaneous lithotripsy - discharge; Endoscopic lithotripsy - discharge; ESWL - discharge

  1. Pancreatitis - discharge

    MedlinePlus

    Chronic pancreatitis - discharge; Pancreatitis - chronic - discharge; Pancreatic insufficiency - discharge; Acute pancreatitis - discharge ... You were in the hospital because you have pancreatitis. This is a swelling of the pancreas. You ...

  2. Ontogeny of a flood plain

    USGS Publications Warehouse

    Moody, J.A.; Pizzuto, J.E.; Meade, R.H.

    1999-01-01

    The ontogeny of five flood-plain segments is described for a period of 18 yr following a major flood in 1978 on the Powder River in southeastern Montana. The flood plains developed on relatively elevated sand and gravel deposits left within the channel by the 1978 flood. In cross section, the flood plains resemble benches with well-developed natural levees. Flood-plain growth occurred as sediment was draped onto preexisting surfaces in layers of sand and mud a few centimeters to decimeters thick, resulting in some lateral, but mostly vertical accretion. Annual and biannual measurements indicated that, as the flood-plain segments grew upward, the annual rate of vertical accretion decreased as the partial duration recurrence interval for the threshold or bankfull discharge increased from 0.16 to 1.3 yr. It is clear that a constant recurrence interval for overbank flow cannot be meaningfully assigned to this type of flood-plain ontogeny. These flood plains did not grow on migrating point bars, and vertical accretion at least initially occurred within the channel, rather than across the valley flat during extensive overbank flows. Sediments of these flood plains define narrow, elongated stratigraphic units that border the active channel and onlap older flood-plain deposits. These characteristics are considerably different from those of many facies models for meandering river deposits. Facies similar to those described in this paper are likely to be preserved, thereby providing important evidence in the geologic record for episodes of periodic channel expansion by ancient rivers.

  3. Climate factor for small-basin flood frequency

    USGS Publications Warehouse

    Lichty, R.W.; Karlinger, M.R.

    1990-01-01

    A climate factor, CT, (T = 2-, 25-, and 100-year recurrence intervals) that delineates regional trends in small-basin flood frequency was derived using data from 71 long-term rainfall record sites. Values of CT at these sites were developed by a regression analysis that related rainfall-runoff model estimates of T-year floods to a sample set of 50 model calibrations. CT was regionalized via kriging to develop maps depicting its geographic variation for a large part of the United States east of the 105th meridian. Kriged estimates of CT and basin-runoff characteristics were used to compute regionalized T-year floods for 200 small drainage basins. Observed T-year flood estimates also were developed for these sites. Regionalized floods are shown to account for a large percentage of the variability in observed flood estimates with coefficients of determination ranging from 0.89 for 2-year floods to 0.82 for 100-year floods. The relative importance of the factors comprising regionalized flood estimates is evaluated in terms of scale (size of drainage area), basin-runoff characteristics (rainfall-runoff model parameters), and climate (CT).

  4. Combining uncertainty-estimation techniques and cost-benefit analysis to obtain consistent design-flood estimators

    NASA Astrophysics Data System (ADS)

    Botto, A.; Ganora, D.; Laio, F.; Claps, P.

    2012-04-01

    selected. In general, this estimator will not correspond to the one obtained with the standard statistical inference, because the expected damages (and the LTEC estimator as a consequence) will depend on the estimation uncertainty. The method has been applied to 10 series of annual maxima, having different lengths and different statistical characteristics; two different probability distribution functions have been used. Results obtained show that the presence of uncertainty in design flood estimation entails an increment of the minimum-cost design floods. This increment is marginal when low return periods are considered, but becomes substantial for return periods larger than 100 years. For example, when a 1000- year return period is considered, the LTEC estimator corresponds to the 0.73 quantile of the T-year discharge distribution obtained with the Monte-Carlo approach (the standard approach produces an estimator corresponding to the median). Difference in magnitude between the two estimators can be as large as 100% when small samples (15-30 years) are considered. In the considered case, the standard flood frequency analysis always produces underestimation of the design flood and entails total costs significantly larger that those obtained with the LTEC approach.

  5. Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment.

    PubMed

    Freschet, Grégoire T; Ostlund, Lars; Kichenin, Emilie; Wardle, David A

    2014-04-01

    Human activities that involve land-use change often cause major transformations to community and ecosystem properties both aboveground and belowground, and when land use is abandoned, these modifications can persist for extended periods. However, the mechanisms responsible for rapid recovery vs. long-term maintenance of ecosystem changes following abandonment remain poorly understood. Here, we examined the long-term ecological effects of two remote former settlements, regularly visited for -300 years by reindeer-herding Sami and abandoned -100 years ago, within an old-growth boreal forest that is considered one of the most pristine regions in northern Scandinavia. These human legacies were assessed through measurements of abiotic and biotic soil properties and vegetation characteristics at the settlement sites and at varying distances from them. Low-intensity land use by Sami is characterized by the transfer of organic matter towards the settlements by humans and reindeer herds, compaction of soil through trampling, disappearance of understory vegetation, and selective cutting of pine trees for fuel and construction. As a consequence, we found a shift towards early successional plant species and a threefold increase in soil microbial activity and nutrient availability close to the settlements relative to away from them. These changes in soil fertility and vegetation contributed to 83% greater total vegetation productivity, 35% greater plant biomass, and 23% and 16% greater concentrations of foliar N and P nearer the settlements, leading to a greater quantity and quality of litter inputs. Because decomposer activity was also 40% greater towards the settlements, soil organic matter cycling and nutrient availability were further increased, leading to likely positive feedbacks between the aboveground and belowground components resulting from historic land use. Although not all of the activities typical of Sami have left visible residual traces on the ecosystem after

  6. Floods of August 1967 in east-central Alaska

    USGS Publications Warehouse

    Childers, Joseph M.; Meckel, James P.; Anderson, Gary S.

    1972-01-01

    East-central Alaska had record floods near Fairbanks following extensive rains of August 8-20, 1967. Precipitation during this period totaled as much as 10 inches, which is close to the average annual precipitation for this area. The most extensive flooding occurred in the White Mountains northeast of Fairbanks and along the major streams draining those mountains. Some of the major streams flooded were the Salcha, Chena, Chatanika, Tolovana, and lower Tanana Rivers, and Birch Creek west of Circle. Peak discharges on some streams in the flood area were from two to four times the probable 50-year flood. The peak discharge of 74,400 cubic feet per second of the Chena River at Fairbanks, from 1,980 square miles of drainage area, was 2.6 times the 50-year flood. The rise of ground-water levels in the Tanana River flood plain to the land surface during the flood caused foundation failures and prevented drainage of subsurface structures. Above-normal ground-water levels existed until the middle of September. Total flood damage was estimated in excess of $85 million. Six lives were reported lost, and about 12,000 persons were evacuated during the flood. This report has been prepared to furnish hydrologic data for development planning. Included are discussions of antecedent streamflow, meteorology of the storm, descriptions of floods, flood damage, flood frequency, ground-water conditions, and stages and discharges of major streams for August 1967.

  7. Application of the U.S. Geological Survey rainfall-runoff simulation model to improve flood-frequency estimates on small Tennessee streams

    USGS Publications Warehouse

    Wibben, Herman C.

    1976-01-01

    The U.S. Geological Survey rainfall-runoff simulation model was used in conjunction with National Weather Service climatological data to improve flood-frequency estimates for 52 small drainage basins in Tennessee. The basins range in size from 0.17 to 64 square miles (0.44 to 166 square kilometers) and are distributed throughout the State. Model parameters were determined by calibration with observed data from each site. Average error of peak discharge simulation was about 36 percent. Techniques used in screening data for calibration as well as those used to optimize parameter values are discussed. A scheme developed to assess the relative accuracy of the frequency curves based on observed and simulated data indicated that the simulated data are equivalent to nine years of observed data in defining 2-year floods, and fifteen years in defining 100-year floods. Discharges corresponding to the best estimate of flows for selected recurrence intervals are tabulated for each modeled basin. (Woodard-USGS)

  8. Regime Shifts in Shallow Lakes: Responses of Cyanobacterial Blooms to Watershed Agricultural Phosphorus Loading Over the Last ~100 Years.

    NASA Astrophysics Data System (ADS)

    Vermaire, J. C.; Taranu, Z. E.; MacDonald, G. K.; Velghe, K.; Bennett, E.; Gregory-Eaves, I.

    2015-12-01

    Rapid changes in ecosystem states have occurred naturally throughout Earth's history. However, environmental changes that have taken place since the start of the Anthropocene may be destabilizing ecosystems and increasing the frequency of regime shifts in response to abrupt changes in external drivers or local intrinsic dynamics. To evaluate the relative influence of these forcers and improve our understanding of the impact of future change, we examined the effects of historical catchment phosphorus loading associated with agricultural land use on lake ecosystems, and whether this caused a shift from a stable, clear-water, regime to a turbid, cyanobacteria-dominated, state. The sedimentary pigments, diatom, and zooplankton (Cladocera) records from a currently clear-water shallow lake (Roxton Pond) and a turbid-water shallow lake (Petit lac Saint-François; PSF) were examined to determine if a cyanobacteria associated pigment (i.e. echinenone) showed an abrupt non-linear response to continued historical phosphorus load index (determined by phosphorus budget) over the last ~100 years. While PSF lake is presently in the turbid-water state, pigment and diatom analyses indicated that both lakes were once in the clear-water state, and that non-linear increases in catchment phosphorus balance resulted in an abrupt transition to cyanobacteria dominated states in each record. These results show that phosphorus loading has resulted in state shifts in shallow lake ecosystems that has been recorded across multiple paleolimnological indicators preserved in the sedimentary record.

  9. DNA from a 100-year-old holotype confirms the validity of a potentially extinct hummingbird species

    PubMed Central

    Kirchman, Jeremy J.; Witt, Christopher C.; McGuire, Jimmy A.; Graves, Gary R.

    2010-01-01

    We used mtDNA sequence data to confirm that the controversial 100-year-old holotype of the Bogotá sunangel (Heliangelus zusii) represents a valid species. We demonstrate that H. zusii is genetically well differentiated from taxa previously hypothesized to have given rise to the specimen via hybridization. Phylogenetic analyses place H. zusii as sister to a clade of mid- to high-elevation Andean species currently placed in the genera Taphrolesbia and Aglaiocercus. Heliangelus zusii, presumed extinct, has never been observed in nature by biologists. We infer that the species occupied a restricted distribution between the upper tropical and temperate zones of the northern Andes and that it was most probably driven to extinction by deforestation that accompanied human population growth during the nineteenth and early twentieth centuries. We demonstrate the feasibility of obtaining DNA from nearly microscopic tissue samples from old hummingbird specimens and suggest that these methods could be used to resolve the taxonomy of dozens of avian taxa known only from type specimens. PMID:19776061

  10. Flood frequency analyses with annual and partial flood series

    NASA Astrophysics Data System (ADS)

    Bezak, N.; Brilly, M.; Sraj, M.

    2012-04-01

    The objective of the study was (1) to analyse the influence of time scale of the data on the results, (2) to analyse the relations between discharge, volume and time of flood waves of the Sava river at Litija (Slovenia), (3) to perform flood frequency analyses of peak discharges with annual and partial data series and compare the results and (4) to explore the influence of threshold value by POT method. Calculations and analyses were made for the period 1953-2010. Daily scale data sets (considering also local maximum) were used. The flood frequency analyses were based on anual and partial data series. The differences between daily and hourly time scale data sets were explored. Daily and hourly time scale hydrographs were compared and differences were analysed. Differences were adequately small. Daily time series with included maximums were logical choice because of the length of the daily time series and because hourly time series were not continuous due to gauging equipment failures. Important objective of the study was to analyse the relationship between discharge, volume and duration of flood waves. Baseflow was separated from continuous daily discharge measurements on simple and complex hydrographs. Simple graphical method with three points was used. Many different coefficients like base flow index were calculated and different combinations of correlation coefficient of wave components were examined. Annual maximum series were used to study the relationship between wave components. Flood frequency analyses were made with annual maximum series and partial duration series. Log-normal distribution, Pearson distribution type 3, log-Pearson distribution type 3, Gumbel distribution, exponential distribution, GEV distribution and GL distribution were used for annual maximum series. Simple equation of linear transformation was used to determine the design discharge and procedure which is proposed in Flood Estimation Handbook was used with GEV and GL distribution

  11. ENSO-triggered floods in South America

    NASA Astrophysics Data System (ADS)

    Isla, Federico Ignacio

    2016-04-01

    ENSO-triggered floods altered completely the annual discharge of most watersheds of South America. Anomalous years as 1941, 1982-83 and 1997-98 signified enormous discharges of rivers draining toward the Pacific but also to the Atlantic Ocean. These floods affected large cities as Porto Alegre, Blumenau, Curitiba, Asunción, Santa Fe and Buenos Aires. Maximum discharge months are particular and easily distinguished at those watersheds located at the South American Arid Diagonal. At watersheds conditioned by precipitations delivered from the Atlantic or Pacific anticyclonic centers the ENSO-triggered floods are difficult to discern. The floods of 1941 affected 70,000 inhabitants in Porto Alegre. In 1983, Blumenau city was flooded during several days; and the Paraná River multiplied 15 times the width of its middle floodplain. The Colorado River in Northern Patagonia connected for the last time to the Desaguadero-Chadileuvú-Curacó system and therefore received saline water. ENSO years modify also the water balance of certain piedmont lakes of Southern Patagonia: the increases in snow accumulations cause high water levels with a lag of 13 months. The correlation between the maximum monthly discharges of 1982-83 and 1997-98 at different regions and watersheds indicates they can be forecasted for future floods triggered by same phenomena. South American rivers can be classified therefore into ENSO-affected, and ENSO-dominated, for those within the Arid Diagonal that are exclusively subject to high discharges during these years.

  12. Flood magnitude and frequency of Jacks Run at the culvert on U.S. Route 206, Southampton Township, Burlington County, New Jersey

    USGS Publications Warehouse

    Barringer, Thomas

    1996-01-01

    Flood magnitude and frequency of Jacks Run at the culvert on U.S. Route 206, Southampton Township, New Jersey, were determined by using the rational method. Flood magnitude and frequency estimates, as well as basin characteristics, are included in this report. The 100-year-flood estimate is 29 cubic feet per second.

  13. Floods of February 1989 in Tennessee

    USGS Publications Warehouse

    Quinones, Ferdinand; Gamble, C.R.

    1990-01-01

    Rainfall amounts of over 5 inches the night of February 13 and the morning of February 14, 1989, caused flooding in areas of Middle and West Tennessee. The towns of Lebanon in Middle Tennessee and Obion in West Tennessee were most severely affected. Most of the business district in Lebanon and many residential areas in Obion were flooded. Recurrence intervals for 24-hour rainfall totals were as high as 25 years at some sites but most peak discharges had recurrence intervals of less than 10 years. Rainfall amounts for the period February 13-20, 1989, peak stages and discharges for this flood, the peak of record, and a list of discharge measurements made during the flood are documented. (USGS)

  14. Estimates of Flow Duration, Mean Flow, and Peak-Discharge Frequency Values for Kansas Stream Locations

    USGS Publications Warehouse

    Perry, Charles A.; Wolock, David M.; Artman, Joshua C.

    2004-01-01

    Streamflow statistics of flow duration and peak-discharge frequency were estimated for 4,771 individual locations on streams listed on the 1999 Kansas Surface Water Register. These statistics included the flow-duration values of 90, 75, 50, 25, and 10 percent, as well as the mean flow value. Peak-discharge frequency values were estimated for the 2-, 5-, 10-, 25-, 50-, and 100-year floods. Least-squares multiple regression techniques were used, along with Tobit analyses, to develop equations for estimating flow-duration values of 90, 75, 50, 25, and 10 percent and the mean flow for uncontrolled flow stream locations. The contributing-drainage areas of 149 U.S. Geological Survey streamflow-gaging stations in Kansas and parts of surrounding States that had flow uncontrolled by Federal reservoirs and used in the regression analyses ranged from 2.06 to 12,004 square miles. Logarithmic transformations of climatic and basin data were performed to yield the best linear relation for developing equations to compute flow durations and mean flow. In the regression analyses, the significant climatic and basin characteristics, in order of importance, were contributing-drainage area, mean annual precipitation, mean basin permeability, and mean basin slope. The analyses yielded a model standard error of prediction range of 0.43 logarithmic units for the 90-percent duration analysis to 0.15 logarithmic units for the 10-percent duration analysis. The model standard error of prediction was 0.14 logarithmic units for the mean flow. Regression equations used to estimate peak-discharge frequency values were obtained from a previous report, and estimates for the 2-, 5-, 10-, 25-, 50-, and 100-year floods were determined for this report. The regression equations and an interpolation procedure were used to compute flow durations, mean flow, and estimates of peak-discharge frequency for locations along uncontrolled flow streams on the 1999 Kansas Surface Water Register. Flow durations, mean

  15. Future flood risk in Europe under high-end climate projections

    NASA Astrophysics Data System (ADS)

    Alfieri, Lorenzo; Feyen, Luc; Bianchi, Alessandra; Burek, Peter; Dottori, Francesco; Forzieri, Giovanni; Roudier, Philippe

    2015-04-01

    a peak over threshold approach; 3) a new methodology is proposed to bias correct the climate projections used, which is performed in the evaluation of the flood risk and therefore does not modify atmospheric variables nor the energy balance; 4) a coherent estimate of vulnerability information is included. Results indicate that the change in frequency of discharge extremes is likely to have a larger impact on the overall flood hazard as compared to the change in their magnitude. This underlines some limitations embedded in the commonly used block-maxima analysis on annual peak discharges. On a continental average, flood peaks with return period above 100 years are projected to double in frequency within the next few decades. This is reflected into an average 200 percent climate-related increase in the future expected damage and population affected by the end of the century in Europe.

  16. Polymer flooding

    SciTech Connect

    Littmann, W.

    1988-01-01

    This book covers all aspects of polymer flooding, an enhanced oil recovery method using water soluble polymers to increase the viscosity of flood water, for the displacement of crude oil from porous reservoir rocks. Although this method is becoming increasingly important, there is very little literature available for the engineer wishing to embark on such a project. In the past, polymer flooding was mainly the subject of research. The results of this research are spread over a vast number of single publications, making it difficult for someone who has not kept up-to-date with developments during the last 10-15 years to judge the suitability of polymer flooding to a particular field case. This book tries to fill that gap. An indispensable book for reservoir engineers, production engineers and lab. technicians within the petroleum industry.

  17. Flood Duration and Time of Flood Onset Effects on Recently Planted Sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Periodically flooding sugarcane (Saccharum spp.) in the Everglades Agricultural Area (EAA) of Florida improves soil conservation and reduces P discharge to the Everglades, but farmers are concerned that flooding recently planted or recently ratooned sugarcane reduces yields. The purpose of this stud...

  18. 44 CFR 65.6 - Revision of base flood elevation determinations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DC, and shall be accompanied by the appropriate payment, in accordance with 44 CFR part 72. ... revised hydrologic analysis for flooding sources with established base flood elevations must include... 500-year flood discharges. (8) A revised hydraulic analysis for a flooding source with...

  19. 44 CFR 65.6 - Revision of base flood elevation determinations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DC, and shall be accompanied by the appropriate payment, in accordance with 44 CFR part 72. ... revised hydrologic analysis for flooding sources with established base flood elevations must include... 500-year flood discharges. (8) A revised hydraulic analysis for a flooding source with...

  20. 44 CFR 65.6 - Revision of base flood elevation determinations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DC, and shall be accompanied by the appropriate payment, in accordance with 44 CFR part 72. ... revised hydrologic analysis for flooding sources with established base flood elevations must include... 500-year flood discharges. (8) A revised hydraulic analysis for a flooding source with...

  1. The anticipated spatial loss of microtidal beaches in the next 100 years due to sea level rise.

    NASA Astrophysics Data System (ADS)

    Alexandrakis, G.; Poulos, S.

    2012-04-01

    The anticipated sea level rise is expected to influence on a global scale the earth coast in the near future and it is considered to be a main factor related to coastal retreat, with beach zones being among the most vulnerable coastal landforms. Records for the period 1890-1990 have shown that sea level has already risen by 18cm (min: +10cm, max: +25cm), while the projected to 2100 sea level rise has estimated to be 20 to 50cm (IPCC, 2007). It has to be highlighted that a small rise of few tens of meters would cause shoreline retreat of a few to tens meters in the case of low lying coasts, i.e. beach zones (e.g. Bruun 1962, Nichol and Letherman, 1995, Ciavola and Corbau, 2002). Within the concept of climate change, sea level rise could also being related, in regional scale, to changes of meteorological factors such as intensity, duration and direction of the onshore blowing winds, variation in atmospheric pressure. In the microtidal Greek waters temporary changes in sea level exceeds the 1 m (HHS, 2004) This work investigates the impact of sea level rise to sixteen beach zones along the Greek coast. More specifically, shoreline retreat has been estimated for time periods of 10, 20, 50 and 100 years for the corresponding sea level rise of 0,038, 0,076m, 0,19m and 0,38m, according to the A1B scenario of IPCC (2007) and utilizing Dean's (1991) equation; the latter includes in the calculations both the effects of the anticipated sea level rise and the associated storm surge The appropriate morphodynamic and sedimentological data used for the estimation of beach retreat has been deduced from field measurements. Finally, the percentage of the sub-aerial area lost for each beach zone, under investigation, has been estimated. The results show that coastline retreat follows a liner increase in the case of eleven out of the 16 beach zones, for a time period of 100 years. Santava beach zone (inner Messiniakos Gulf) undergoes most of erosion in the first period of 20 years

  2. Changing patterns of infant death over the last 100 years: autopsy experience from a specialist children's hospital

    PubMed Central

    Pryce, JW; Weber, MA; Ashworth, MT; Roberts, SEA; Malone, M; Sebire, NJ

    2012-01-01

    Objectives Infant mortality has undergone a dramatic reduction in the UK over the past century because of improvements in public health policy and medical advances. Postmortem examinations have been performed at Great Ormond Street Hospital for over 100 years, and analysis of cases across this period has been performed to assess changing patterns of infant deaths undergoing autopsy. Design Autopsy reports from 1909 and 2009 were examined. Age, major pathology and cause of death was reviewed from these cases and entered into an anonymized database. A subsequent comparative analysis was performed. Setting All postmortems performed and reported at Great Ormond Street Hospital in 1909 and 2009. Participants Infant deaths, aged 0–365 days, were identified and subsequently analysed for the two years. Main outcome measures Comparative proportional analysis of postmortem findings from the two time periods. Results Three-hundred and fifty-seven and 347 autopsy reports were identified from 1909 and 2009 including 178 and 128 infant deaths, respectively. The commonest cause of death in 1909 was infection (74%) compared to 20% of deaths in 2009. The most frequent final ‘diagnosis’ in 2009 was ‘unexplained sudden unexpected infant death (SUDI)’, despite a full postmortem including ancillary investigations. In contrast, there were no such cases recorded in 1909, but there were frequent deaths due to gastroenteritis and malnutrition together accounting for 16% of cases, compared to one case of gastroenteritis in 2009. Fifteen percent of 1909 cases had infections which are almost never fatal with appropriate treatment in 2009, including tuberculosis, diphtheria and syphilis. Congenital anomalies were detected with similar frequencies at both time points, (21% and 19% in 1909 and 2009, respectively). Conclusion In the UK, significant changes in patterns of pathology have occurred in paediatric autopsy cases performed at a single specialist centre. Fatal infections and

  3. Current-wave spectra coupling project. Volume I. Hurricane fields and cross sections, surface winds and currents, significant waves and wave spectra for potential OTEC sites: (A) Keahole Point, Hawaii, 100 year hurricane; (B) Punta Tuna, Puerto Rico, 100 year hurricane; (C) New Orleans, Louisiana, 100 year hurricane; (D) West Coast of Florida, 100 year hurricane; and for (E) Hurricane Camille (1969) off Louisiana Coast

    SciTech Connect

    Bretschneider, C.L.

    1980-06-01

    This volume is an extension of and consists of several modifications to the earlier report by Bretschneider (April 1979) on the subject of hurricane design wind, wave and current criteria for the four potential OTEC sites. The 100-year hurricane criteria for the design of OTEC plants is included. The criteria, in addition to the maximum conditions of winds, waves and surface current, include: hurricane fields for wind speed U/sub s/ and significant wave height H/sub s/; hurricane fields for modal wave period f/sub 0//sup -1/ and maximum energy density S/sub max/ of the wave spectrum; the corresponding Ekman wind-driven surface current V/sub s/; tabulated cross-sections for U/sub s/, H/sub s/, f/sub 0//sup -1/ and S/sub max/ through max U/sub s/ and through max H/sub s/ along traverses at right angles to and along traverses parallel to the forward movement of the hurricane; most probable maximum wave height and the expected corresponding wave period, based on statistical analysis of maximum wave heights from five hurricanes; design wave spectra for maximum U/sub s/ and also maximum H/sub s/, since maximum U/sub s/ and maximum H/sub s/ do not occur simultaneously; the envelope of wave spectra through maximum U/sub s/ and through maximum H/sub s/ along traverses parallel to the forward movement of the hurricane; the above same determinations for Hurricane Camille (1969) as for the four OTEC locations; and alternative methods (suggested) for obtaining design wave spectra from the joint probability distribution functions for wave height and period given by Longuet-Higgins (1975) and C.N.E.X.O. after Arhan, et al (1976).

  4. Acidophilic denitrifiers dominate the N2O production in a 100-year-old tea orchard soil.

    PubMed

    Huang, Ying; Long, Xi-En; Chapman, Stephen J; Yao, Huaiying

    2015-03-01

    Aerobic denitrification is the main process for high N2O production in acid tea field soil. However, the biological mechanisms for the high emission are not fully understood. In this study, we examined N2O emission and denitrifier communities in 100-year-old tea soils with four pH levels (3.71, 5.11, 6.19, and 7.41) and four nitrate concentration (0, 50, 200, and 1000 mg kg(-1) of NO3 (-)-N) addition. Results showed the highest N2O emission (10.1 mg kg(-1) over 21 days) from the soil at pH 3.71 with 1000 mg kg(-1) NO3 (-) addition. The N2O reduction and denitrification enzyme activity in the acid soils (pH <7.0) were significantly higher than that of soils at pH 7.41. Moreover, TRF 78 of nirS and TRF 187 of nosZ dominated in soils of pH 3.71, suggesting an important role of acidophilic denitrifiers in N2O production and reduction. CCA analysis also showed a negative correlation between the dominant denitrifier ecotypes (nirS TRF 78, nosZ TRF 187) and soil pH. The representative sequences were identical to those of cultivated denitrifiers from acidic soils via phylogenetic tree analysis. Our results showed that the acidophilic denitrifier adaptation to the acid environment results in high N2O emission in this highly acidic tea soil. PMID:25273518

  5. Lung surgery - discharge

    MedlinePlus

    Thoracotomy - discharge; Lung tissue removal - discharge; Pneumonectomy - discharge; Lobectomy - discharge; Lung biopsy - discharge; Thoracoscopy - discharge; Video-assisted thoracoscopic surgery - discharge; VATS - ...

  6. The story of the Hawaiian Volcano Observatory -- A remarkable first 100 years of tracking eruptions and earthquakes

    USGS Publications Warehouse

    Babb, Janet L.; Kauahikaua, James P.; Tilling, Robert I.

    2011-01-01

    The year 2012 marks the centennial of the Hawaiian Volcano Observatory (HVO). With the support and cooperation of visionaries, financiers, scientists, and other individuals and organizations, HVO has successfully achieved 100 years of continuous monitoring of Hawaiian volcanoes. As we celebrate this milestone anniversary, we express our sincere mahalo—thanks—to the people who have contributed to and participated in HVO’s mission during this past century. First and foremost, we owe a debt of gratitude to the late Thomas A. Jaggar, Jr., the geologist whose vision and efforts led to the founding of HVO. We also acknowledge the pioneering contributions of the late Frank A. Perret, who began the continuous monitoring of Kīlauea in 1911, setting the stage for Jaggar, who took over the work in 1912. Initial support for HVO was provided by the Massachusetts Institute of Technology (MIT) and the Carnegie Geophysical Laboratory, which financed the initial cache of volcano monitoring instruments and Perret’s work in 1911. The Hawaiian Volcano Research Association, a group of Honolulu businessmen organized by Lorrin A. Thurston, also provided essential funding for HVO’s daily operations starting in mid-1912 and continuing for several decades. Since HVO’s beginning, the University of Hawaiʻi (UH), called the College of Hawaii until 1920, has been an advocate of HVO’s scientific studies. We have benefited from collaborations with UH scientists at both the Hilo and Mänoa campuses and look forward to future cooperative efforts to better understand how Hawaiian volcanoes work. The U.S. Geological Survey (USGS) has operated HVO continuously since 1947. Before then, HVO was under the administration of various Federal agencies—the U.S. Weather Bureau, at the time part of the Department of Agriculture, from 1919 to 1924; the USGS, which first managed HVO from 1924 to 1935; and the National Park Service from 1935 to 1947. For 76 of its first 100 years, HVO has been

  7. 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

  8. Characterization of remarkable floods in France, a transdisciplinary approach applied on generalized floods of January 1910

    NASA Astrophysics Data System (ADS)

    Boudou, Martin; Lang, Michel; Vinet, Freddy; Coeur, Denis

    2014-05-01

    emphasize one flood typology or one flood dynamic (for example flash floods are often over-represented than slow dynamic floods in existing databases). Thus, the selected criteria have to introduce a general overview of flooding risk in France by integrating all typologies: storm surges, torrential floods, rising groundwater level and resulting to flood, etc. The methodology developed for the evaluation grid is inspired by several scientific works related to historical hydrology (Bradzil, 2006; Benito et al., 2004) or extreme floods classification (Kundzewics et al. 2013; Garnier E., 2005). The referenced information are mainly issued from investigations realized for the PFRA (archives, local data),from internet databases on flooding disasters, and from a complementary bibliography (some scientists such as Maurice Pardé a geographer who largely documented French floods during the 20th century). The proposed classification relies on three main axes. Each axis is associated to a set of criteria, each one related to a score (from 0.5 to 4 points), and pointing out a final remarkability score. • The flood intensity characterizing the flood's hazard level. It is composed of the submersion duration, important to valorize floods with slow dynamics as flooding from groundwater, the event peak discharge's return period, and the presence of factors increasing significantly the hazard level (dykes breaks, log jam, sediment transport…) • The flood severity focuses on economic damages, social and political repercussions, media coverage of the event, fatalities number or eventual flood warning failures. Analyzing the flood consequences is essential in order to evaluate the vulnerability of society at disaster date. • The spatial extension of the flood, which contributes complementary information to the two first axes. The evaluation grid was tested and applied on the sample of 176 remarkable events. Around twenty events (from 1856 to 2010) come out with a high remarkability rate

  9. Hysterectomy - laparoscopic - discharge

    MedlinePlus

    Supracervical hysterectomy - discharge; Removal of the uterus - discharge; Laparoscopic hysterectomy - discharge; Total laparoscopic hysterectomy - discharge; TLH - discharge; Laparoscopic supracervical ...

  10. Shoulder replacement - discharge

    MedlinePlus

    Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; ...

  11. Radical prostatectomy - discharge

    MedlinePlus

    ... prostatectomy - discharge; Laparoscopic radical prostatectomy - discharge; LRP - discharge; Robotic-assisted laparoscopic prostatectomy - discharge ; RALP - discharge; Pelvic lymphadenectomy - ...

  12. Estimating the Response of Physical Processes in the South San Francisco Bay for Flood Stage Frequency Analysis

    NASA Astrophysics Data System (ADS)

    Andes, L.; Wu, F.; MacWilliams, M.; Lu, C.; Lo, J.

    2012-12-01

    Coastal flooding in the far south San Francisco Bay (SSFB) can be a function of astronomical tide, residual tide, in-bay wind speed and direction and fluvial discharge. These physical processes and coastal levee failure were considered as input parameters into a Monte Carlo Simulation (MCS) to estimate coastal flood stage frequency in the SSFB. Limited data is available in the SSFB to estimate the contribution of these physical processes to coastal flood statistics. Over 100 years of measured water surface elevation (WSE) is available at the San Francisco tide station which can be used as input to hydrodynamic model simulations to estimate the WSE response in the SSFB. Data sampling criteria have been developed to select significant events at the San Francisco tide station for data transfer to the project site and statistical analysis. The coincidently sampled astronomical and residual tides at the San Francisco tide station were analyzed to cover the full range of the combinations of astronomical and residual tides that contribute to coastal flood statistics at the project site. A look-up table of astronomical and residual tide in the form of WSE responses at the project site from the hydrodynamic simulations was established for the interpolation in the MCS. The hydrodynamic model simulations indicated that the higher-high astronomical tides between 5.15 and 7.25 feet MLLW amplifies with a factor of 1.40 to 1.90 as a function of tidal frequency and water depth, including tidal range. The residual tide varies minimally as it propagates into the SSFB. In-Bay wind set-up from a significant event was found to contribute on the order of one foot to the total WSE in the SSFB; however, wind events with strong magnitudes along the primary axis of the bay occur infrequently making an insignificant contribution to the overall flood statistics. The fluvial discharges of Guadalupe River and Coyote Creek were considered in the hydrodynamic simulations as they are located

  13. 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.

  14. A technique for estimating flood heights on small streams in the city of Charlotte and Mecklenburg County, North Carolina

    USGS Publications Warehouse

    Eddins, William H.; Jackson, N.M., Jr.

    1980-01-01

    A method for estimating the height reached by floods having recurrence intervals of 10, 20, and 100 years is defined for unregulated streams in Charlotte and Mecklenburg County draining areas of less than 1.0 square mile. Flood heights, defined as the vertical distance between the streambed at riffles and the floodwater surface, can be used to estimate flood elevations on small streams where flood profiles and flood inundation maps are not available. An illustrative example is given of how the method can be used with streambed elevation data and topographic maps to estimate flood elevations and delineate inundated areas.

  15. Accumulation of Pharmaceuticals, Enterococcus, and Resistance Genes in Soils Irrigated with Wastewater for Zero to 100 Years in Central Mexico

    PubMed Central

    Siebe, Christina; Willaschek, Elisha; Sakinc, Tuerkan; Huebner, Johannes; Amelung, Wulf; Grohmann, Elisabeth; Siemens, Jan

    2012-01-01

    Irrigation with wastewater releases pharmaceuticals, pathogenic bacteria, and resistance genes, but little is known about the accumulation of these contaminants in the environment when wastewater is applied for decades. We sampled a chronosequence of soils that were variously irrigated with wastewater from zero up to 100 years in the Mezquital Valley, Mexico, and investigated the accumulation of ciprofloxacin, enrofloxacin, sulfamethoxazole, trimethoprim, clarithromycin, carbamazepine, bezafibrate, naproxen, diclofenac, as well as the occurrence of Enterococcus spp., and sul and qnr resistance genes. Total concentrations of ciprofloxacin, sulfamethoxazole, and carbamazepine increased with irrigation duration reaching 95% of their upper limit of 1.4 µg/kg (ciprofloxacin), 4.3 µg/kg (sulfamethoxazole), and 5.4 µg/kg (carbamazepine) in soils irrigated for 19–28 years. Accumulation was soil-type-specific, with largest accumulation rates in Leptosols and no time-trend in Vertisols. Acidic pharmaceuticals (diclofenac, naproxen, bezafibrate) were not retained and thus did not accumulate in soils. We did not detect qnrA genes, but qnrS and qnrB genes were found in two of the irrigated soils. Relative concentrations of sul1 genes in irrigated soils were two orders of magnitude larger (3.15×10−3±0.22×10−3 copies/16S rDNA) than in non-irrigated soils (4.35×10−5±1.00×10−5 copies/16S rDNA), while those of sul2 exceeded the ones in non-irrigated soils still by a factor of 22 (6.61×10–4±0.59×10−4 versus 2.99×10−5±0.26×10−5 copies/16S rDNA). Absolute numbers of sul genes continued to increase with prolonging irrigation together with Enterococcus spp. 23S rDNA and total 16S rDNA contents. Increasing total concentrations of antibiotics in soil are not accompanied by increasing relative abundances of resistance genes. Nevertheless, wastewater irrigation enlarges the absolute concentration of resistance genes in soils due to a long-term increase in

  16. Historical changes in frequency of extreme floods in Prague

    NASA Astrophysics Data System (ADS)

    Elleder, L.

    2015-10-01

    This study presents a flood frequency analysis for the Vltava River catchment using a major profile in Prague. The estimates of peak discharges for the pre-instrumental period of 1118-1824 based on documentary sources were carried out using different approaches. 187 flood peak discharges derived for the pre-instrumental period augmented 150 records for the instrumental period of 1825-2013. Flood selection was based on Q10 criteria. Six flood-rich periods in total were identified for 1118-2013. Results of this study correspond with similar studies published earlier for some central European catchments, except for the period around 1750. Presented results indicate that the territory of the present Czech Republic might have experienced extreme floods in the past, comparable - with regard to peak discharge (higher than or equal to Q10) and frequency - to the flood events recorded recently.

  17. A Preliminary Evaluation of Season-ahead Flood Risks Globally

    NASA Astrophysics Data System (ADS)

    Lee, D.; Ward, P.; Block, P. J.

    2015-12-01

    Globally, flood catastrophes lead all natural hazards in terms of impacts on society, causing billions of dollars of damages each year. While short-term flood warning systems are improving in number and sophistication, forecasting systems on the order of months to seasons are a rarity, yet may lead to further disaster preparedness. In this study, prospects of season-ahead flood forecasts are investigated by examining inter-annual climate variability on seasonal maximum floods, particularly how ENSO and other large-scale phenomena may modulate discharge and flood severity. Predictability of main seasonal floods is also assessed globally using PCR-GLOBWB simulations with large- and local- climate drivers, and validated with GRDC streamflow. Skillful prediction can lead to season-ahead flood probabilities, flood extent, estimated damages, and eventually integrate into early warning systems for informed advanced planning and management. This is especially attractive for regions with limited observations and/or little capacity to develop early warning flood systems.

  18. Flood frequency of the Savannah River at Augusta, Georgia

    USGS Publications Warehouse

    Sanders, C.L., Jr.; Kubik, H.E.; Hoke, J.T., Jr.; Kirby, W.H.

    1990-01-01

    To fill an increasing need for reliable information on floods of various recurrence intervals on the Savannah River a flood-frequency relation was developed for the long-term gaging station at Augusta, Georgia. The flood-frequency analysis was complicated by the fact that the Savannah River upstream of Augusta has experienced increasing regulation of flow caused by three large dams constructed since 1952. The pre-impoundment period was important to the flood-frequency analysis because it included a number of large floods that, even when adjusted for regulation, exceed all floods since 1952. A reservoir routing model was used to adjust nine such floods for the effects of regulation, and to develop a relation for estimating regulated peak discharges for additional unregulated floods. The 1% chance exceedance flood for regulated conditions on the Savannah River at Augusta was computed as 180,000 cu ft/sec. (USGS)

  19. Somerset County Flood Information System

    USGS Publications Warehouse

    Hoppe, Heidi L.

    2007-01-01

    The timely warning of a flood is crucial to the protection of lives and property. One has only to recall the floods of August 2, 1973, September 16 and 17, 1999, and April 16, 2007, in Somerset County, New Jersey, in which lives were lost and major property damage occurred, to realize how costly, especially in terms of human life, an unexpected flood can be. Accurate forecasts and warnings cannot be made, however, without detailed information about precipitation and streamflow in the drainage basin. Since the mid 1960's, the National Weather Service (NWS) has been able to forecast flooding on larger streams in Somerset County, such as the Raritan and Millstone Rivers. Flooding on smaller streams in urban areas was more difficult to predict. In response to this problem the NWS, in cooperation with the Green Brook Flood Control Commission, installed a precipitation gage in North Plainfield, and two flash-flood alarms, one on Green Brook at Seeley Mills and one on Stony Brook at Watchung, in the early 1970's. In 1978, New Jersey's first countywide flood-warning system was installed by the U.S. Geological Survey (USGS) in Somerset County. This system consisted of a network of eight stage and discharge gages equipped with precipitation gages linked by telephone telemetry and eight auxiliary precipitation gages. The gages were installed throughout the county to collect precipitation and runoff data that could be used to improve flood-monitoring capabilities and flood-frequency estimates. Recognizing the need for more detailed hydrologic information for Somerset County, the USGS, in cooperation with Somerset County, designed and installed the Somerset County Flood Information System (SCFIS) in 1990. This system is part of a statewide network of stream gages, precipitation gages, weather stations, and tide gages that collect data in real time. The data provided by the SCFIS improve the flood forecasting ability of the NWS and aid Somerset County and municipal agencies in

  20. On the estimation of the design flood of different dams in Sardinia (Italy)

    NASA Astrophysics Data System (ADS)

    Cortis, C.; Barrui, M.; Montaldo, N.; Saba, A.; Albertson, J. D.

    2012-04-01

    methods for flood predictions. Furthermore local statistic of the rainfall IDF curve are analyzed, highlighting an interesting increase of rainfall extreme in the mountain East Sardinian rain stations (daily rainfall of almost 600 mm in December 2004). In this way synthetic hyetograph and hydrograph are estimated for the design flood of return period of 1000 years. The results show that the flood increases with the position of the peak of the hydrograph due to the soil saturation; the time peaks of the hydrograph and of the flood hydrograph are different: it depends on the propagation in the channel and on the soil permeability. In the last part of the work we use the hydrograph flood of the project calibrated to verify the safety of the dam for a return period of 1000 years. From these analysis the dams of the considered basins will be overflowed by a rain with a return period of less than 100 years.

  1. Estimation of peak-frequency relations, flood hydrographs, and volume-duration-frequency relations of ungaged small urban streams in Ohio

    USGS Publications Warehouse

    Sherwood, J.M.

    1993-01-01

    Methods are presented to estimate peak-frequency relations, flood hydrographs, and volume-duration-frequency relations of urban streams in Ohio with drainage areas less than 6.5 square miles. The methods were developed to assist planners in the design of hydraulic structures for which hydrograph routing is required or where the temporary storage of water is an important element of the design criteria. Examples of how to use the methods also are presented. The data base for the analyses consisted of 5-minute rainfall-runoff data collected for a period of 5 to 8 years at 62 small drainage basins distributed throughout Ohio. The U.S. Geological Survey rainfall-runoff model A634 was used and was calibrated for each site. The calibrayed models were used in conjunction with long-term (66-87 years) rainfall and evaporation records to synthesize a long-term series of flood-hydrograph records at each site. A method was developed and used to increase the variance of the synthetic flood characterictics in order to make them more representative of observed flood characteristics. Multiple-regression equations were developed to estimate peak discharges having recurrence intervals of 2, 5, 10, 25, 50, and 100 years. The explanatory variables in the peak-discharge equations are drainage area, average annual precipitation, and basin development factor. Average standard errors of prediction for the peak-frequency equations range from ? 34 to ? 40 percent. A method is presented to estimate flood hydrographs by applying a specific peak discharge and basin lagtime to a dimensionless hydrograph. An equation was developed to estimate basin lagtime in which main-channel length divided by the square root of the main-channel slope (L/SL) and basin-development factor are the explanatory variables and the average standard error of prediction is ? 53 percent. A dimensional hydrograph originally developed by the U.S. Geological Survey for use in Georgia was verified for use in urban areas of

  2. Effect of urban development on floods in the Piedmont Province of North Carolina

    USGS Publications Warehouse

    Putnam, Arthur L.

    1972-01-01

    Changes from rural to urban conditions significantly affect flood flows. Urban development may reduce the basin laf time to one-sixteenth that of comparable natural system. This reduction in basin lag time, along with the increased storm runoff resulting from impervious cover, increases the flood-peak discharge by a factor that ranges up to five. The increase in flood-peak discharge depends on the drainage-basin characteristics and the recurrence interval of the flood.

  3. Flood of August 1-6, 1950, at Wichita Falls, Texas

    USGS Publications Warehouse

    Yost, Ivan Dale

    1951-01-01

    The purpose of this report is to present certain rainfall and runoff data in the flood area in greater detail than is usually found in regular Water-Supply Papers. The report contains a summary of peak discharges at six points, and d~tailed records of discharge during the flood period at five points in the vicinity of Wichita Falls. The report also contains a discussion of rainfall associated with the flood and a description of the general features of the flood.

  4. An Evaluation of Selected Extraordinary Floods in the United States Reported by the U.S. Geological Survey and Implications for Future Advancement of Flood Science

    USGS Publications Warehouse

    Costa, John E.; Jarrett, Robert D.

    2008-01-01

    Thirty flood peak discharges determine the envelope curve of maximum floods documented in the United States by the U.S. Geological Survey. These floods occurred from 1927 to 1978 and are extraordinary not just in their magnitude, but in their hydraulic and geomorphic characteristics. The reliability of the computed discharge of these extraordinary floods was reviewed and evaluated using current (2007) best practices. Of the 30 flood peak discharges investigated, only 7 were measured at daily streamflow-gaging stations that existed when the flood occurred, and 23 were measured at miscellaneous (ungaged) sites. Methods used to measure these 30 extraordinary flood peak discharges consisted of 21 slope-area measurements, 2 direct current-meter measurements, 1 culvert measurement, 1 rating-curve extension, and 1 interpolation and rating-curve extension. The remaining four peak discharges were measured using combinations of culvert, slope-area, flow-over-road, and contracted-opening measurements. The method of peak discharge determination for one flood is unknown. Changes to peak discharge or rating are recommended for 20 of the 30 flood peak discharges that were evaluated. Nine floods retained published peak discharges, but their ratings were downgraded. For two floods, both peak discharge and rating were corrected and revised. Peak discharges for five floods that are subject to significant uncertainty due to complex field and hydraulic conditions, were re-rated as estimates. This study resulted in 5 of the 30 peak discharges having revised values greater than about 10 percent different from the original published values. Peak discharges were smaller for three floods (North Fork Hubbard Creek, Texas; El Rancho Arroyo, New Mexico; South Fork Wailua River, Hawaii), and two peak discharges were revised upward (Lahontan Reservoir tributary, Nevada; Bronco Creek, Arizona). Two peak discharges were indeterminate because they were concluded to have been debris flows with peak

  5. Flood frequency analysis of historical flood data under stationary and non-stationary modelling

    NASA Astrophysics Data System (ADS)

    Machado, M. J.; Botero, B. A.; López, J.; Francés, F.; Díez-Herrero, A.; Benito, G.

    2015-06-01

    Historical records are an important source of information on extreme and rare floods and fundamental to establish a reliable flood return frequency. The use of long historical records for flood frequency analysis brings in the question of flood stationarity, since climatic and land-use conditions can affect the relevance of past flooding as a predictor of future flooding. In this paper, a detailed 400 yr flood record from the Tagus River in Aranjuez (central Spain) was analysed under stationary and non-stationary flood frequency approaches, to assess their contribution within hazard studies. Historical flood records in Aranjuez were obtained from documents (Proceedings of the City Council, diaries, chronicles, memoirs, etc.), epigraphic marks, and indirect historical sources and reports. The water levels associated with different floods (derived from descriptions or epigraphic marks) were computed into discharge values using a one-dimensional hydraulic model. Secular variations in flood magnitude and frequency, found to respond to climate and environmental drivers, showed a good correlation between high values of historical flood discharges and a negative mode of the North Atlantic Oscillation (NAO) index. Over the systematic gauge record (1913-2008), an abrupt change on flood magnitude was produced in 1957 due to constructions of three major reservoirs in the Tagus headwaters (Bolarque, Entrepeñas and Buendia) controlling 80% of the watershed surface draining to Aranjuez. Two different models were used for the flood frequency analysis: (a) a stationary model estimating statistical distributions incorporating imprecise and categorical data based on maximum likelihood estimators, and (b) a time-varying model based on "generalized additive models for location, scale and shape" (GAMLSS) modelling, which incorporates external covariates related to climate variability (NAO index) and catchment hydrology factors (in this paper a reservoir index; RI). Flood frequency

  6. 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

  7. 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

  8. Simulations of the Greenland ice sheet 100 years into the future with the full Stokes model Elmer/Ice

    NASA Astrophysics Data System (ADS)

    Seddik, H.; Greve, R.; Zwinger, T.; Gillet-Chaulet, F.; Gagliardini, O.

    2011-12-01

    the surface precipitation and temperature and the set S (three experiments) applies an amplification factor to change the basal sliding velocity. The experiments are compared to a constant climate control run beginning at present (epoch 2004-1-1 0:0:0) and running up to 100 years holding the climate constant to its present state. The experiments with the amplification factor (Set S) show high sensitivities. Relative to the control run, the scenario with an amplification factor of 3x applied to the sliding velocity produces a Greenland contribution to sea level rise of ~25 cm. An amplification factor of 2.5x produces a contribution of ~16 cm and an amplification factor 2x produces a contribution of ~9 cm. The experiments with the changes to the surface precipitation and temperature (set C) show a contribution to sea level rise of ~4 cm when a factor 1x is applied to the temperature and precipitation anomalies. A factor 1.5x produces a sea level rise of ~8 cm and a factor 2x produces a sea level rise of ~12 cm.

  9. Flash flood frequency assessment from historical data in an ungauged basin: the Ondara River at Tàrrega (NE Spain)

    NASA Astrophysics Data System (ADS)

    Balasch, J. C.; Tuset, J.; Ruiz-Bellet, J. Ll.

    2010-09-01

    (2001) plotting-position methodology for non-systematic data series was used to estimate the return period of each reconstructed peak flow. Finally, a type I extreme value distribution (Gumbel) was graphically fitted to these coupled values (peak flow-return period). The reconstructed sediment-laden peak flows of the six floods and their plotting-position-derived return period were: 1600 m3s-1 and 667 years (1644 flood); 1200 m3s-1 and 239 years (1874 flood); 500 m3s-1 and 146 years (1783 flood); 250 m3s-1 and 105 years (1842, 1930 and 1989 floods). The Gumbel distribution fitted to these coupled values gave the following expected peak flows: Q100years de 275 m3s-1, Q500years de 1500 m3s-1 and Q1000years de 2500 m3s-1. The goodness of fit, calculated with the Kolmogorov-Smirnov test for a four-sized sample (since 1842, 1930 and 1989 floods have the same magnitude) and a type I error of 1%, was accepted. This relationship between flood magnitude and frequency for the Ondara River at Tàrrega -estimated through historical reconstruction procedures- is very different from the one calculated by the Catalan Hydraulic Authority in the Civil Protection Plan Against Flood Risk (INUNCAT) with a rainfall-discharge global modelling using maximum rainfall data series, which gives the following values: Q100years de 87 m3s-1, Q500years de 164 m3s-1 and Q1000years de 231 m3s-1. This difference may have three explanations: 1) The type I error for rejecting the null hypothesis, that is, for rejecting the goodness of fit of the Gumbel distribution, was too low (1%) 2) Since the peak flows have been calculated with a rainfall-discharge model, the INUNCAT return periods are those of the rain depths instead of those of the peak flows; and, since the relationship between the magnitude of the rainstorm and that of its resulting flood is not bijective -unlike a rainfall-discharge modelling assumes-, the return periods are not correct. 3) The INUNCAT flows are calculated from daily rainfall

  10. 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.

  11. 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

  12. Flood elevation limits in the rocky mountains

    USGS Publications Warehouse

    Jarrett, Robert D.

    1993-01-01

    An analysis of 77,987 station-years of streamflow-gaging station data from 3,748 stations in the Rocky Mountains indicates that there is a latitude-dependent elevation limit to substantial rainfall-produced flooding. The elevation limit ranges from about 1,650 m in Montana to about 2,350 m in New Mexico. Above this elevation limit, large rainfall-produced floods occur very infrequently and maximum unit discharge is 1.7 m3/s/km2 or less. Below this elevation limit, large-magnitude flooding is more common and maximum unit discharge ranges from to 30 m3/s/km2 in Idaho and Montana to 59 m3/s/km2 in New Mexico. These results emphasize the critical need for additional research to increase our knowledge of floods, and have important implications in water-resources investigations in the Rocky Mountains.

  13. SIMULATION OF FLOOD HYDROGRAPHS FOR GEORGIA STREAMS.

    USGS Publications Warehouse

    Inman, E.J.; Armbruster, J.T.

    1986-01-01

    Flood hydrographs are needed for the design of many highway drainage structures and embankments. A method for simulating these flood hydrographs at urban and rural ungauged sites in Georgia is presented. The O'Donnell method was used to compute unit hydrographs from 355 flood events from 80 stations. An average unit hydrograph and an average lag time were computed for each station. These average unit hydrographs were transformed to unit hydrographs having durations of one-fourth, one-third, one-half, and three-fourths lag time and then reduced to dimensionless terms by dividing the time by lag time and the discharge by peak discharge. Hydrographs were simulated for these 355 flood events and their widths were compared with the widths of the observed hydrographs at 50 and 75 percent of peak flow. For simulating hydrographs at sites larger than 500 mi**2, the U. S. Geological Survey computer model CONROUT can be used.

  14. The Hat Yai 2000 flood: the worst flood in Thai history

    NASA Astrophysics Data System (ADS)

    Supharatid, Seree

    2006-02-01

    Hat Yai, the largest commercial and tourist city in southern Thailand, is subjected to regular flood events, primarily during the northeast monsoon period. Flooding in this region is recognized as a serious disaster in terms of frequency, rate of risk, and affected areas. The monsoon of 21-25 November 2000 caused extremely heavy rain in the southern part of Thailand, resulting in a great flood occupying Hat Yai. This caused significant damage. Therefore, the use of both structural and non-structural measures is mandatory to reduce the economic losses and the risk for society. This paper investigates two modelling approaches for flood prevention and mitigation of Hat Yai city. First, a hard computing approach by a physically distributed model was applied to study the flood behaviour in a two-dimensional floodplain flow. Second, a soft computing approach using a neuro-genetic algorithm was used to develop a flood-forecasting tool. It was found that the great flood of 2000 can be simulated well by the FLO-2D model. Computed discharges and flood level in the floodplain are close to the observed data. Countermeasures using diversion canals are guaranteed to accelerate the floodwater drainage to Songkla Lake, significantly reducing the flood impact to the people. In addition, the flood forecasting technique developed in this study can give satisfactory results. This would be very useful as a flood-warning tool for the community

  15. Effectiveness of Water Infrastructure for River Flood Management: Part 2 - Flood Risk Assessment and Its Changes in Bangladesh

    NASA Astrophysics Data System (ADS)

    Kwak, Y.; Gusyev, M.; Arifuzzaman, B.; Khairul, I.; Iwami, Y.; Takeuchi, K.

    2015-06-01

    A case study of Bangladesh presents a methodological possibility based on a global approach for assessing river flood risk and its changes considering flood hazard, exposure, basic vulnerability and coping capacity. This study consists of two parts in the issue of flood change: hazard assessment (Part 1) and risk assessment (Part 2). In Part 1, a hazard modeling technology was introduced and applied to the Ganges, Brahmaputra and Meghna (GBM) basin to quantify the change of 50- and 100-year flood hazards in Bangladesh under the present (1979-2003) and future (2075-2099) climates. Part 2 focuses on estimating nationwide flood risk in terms of affected people and rice crop damage due to a 50-year flood hazard identified in Part 1, and quantifying flood risk changes between the presence and absence of existing water infrastructure (i.e., embankments). To assess flood risk in terms of rice crop damage, rice paddy fields were extracted and flood stage-damage curves were created for maximum risk scenarios as a demonstration of risk change in the present and future climates. The preliminary results in Bangladesh show that a tendency of flood risk change strongly depends on the temporal and spatial dynamics of exposure and vulnerability such as distributed population and effectiveness of water infrastructure, which suggests that the proposed methodology is applicable anywhere in the world.

  16. Floodplain management in Africa: Large scale analysis of flood data

    NASA Astrophysics Data System (ADS)

    Padi, Philip Tetteh; Baldassarre, Giuliano Di; Castellarin, Attilio

    2011-01-01

    To mitigate a continuously increasing flood risk in Africa, sustainable actions are urgently needed. In this context, we describe a comprehensive statistical analysis of flood data in the African continent. The study refers to quality-controlled, large and consistent databases of flood data, i.e. maximum discharge value and times series of annual maximum flows. Probabilistic envelope curves are derived for the African continent by means of a large scale regional analysis. Moreover, some initial insights on the statistical characteristics of African floods are provided. The results of this study are relevant and can be used to get some indications to support flood management in Africa.

  17. Flood risk mapping at European scale.

    PubMed

    Barredo, J I; de Roo, A; Lavalle, C

    2007-01-01

    The aim of this article is to illustrate a framework for flood risk mapping at pan-European scale produced by the Weather-Driven Natural Hazards (WDNH) action of the EC-JRC-IES. Early results are presented in the form of flood risk index maps. We assess several flood risk factors that contribute to the occurrence of flood disasters. Among the causal factors of a flood disaster one is triggering a natural event in the form of extreme precipitation and consequently extreme river discharge and extreme flood water levels. The threatening natural event represents the hazard component in our assessment. Furthermore exposure and vulnerability are anthropogenic factors that contribute also to flood risk. In the proposed approach, flood risk is considered on the light of exposure, vulnerability and hazard. We use a methodology with a marked territorial approach for the assessment of the flood risk. Hence, based on mathematical calculations, risk is the product of hazard, exposure and vulnerability. Improvements on datasets availability and spatial scale are foreseen in the next phases of this study. This study is also a contribution to the discussion about the need for communication tools between the natural hazard scientific community and the political and decision making players in this field. PMID:17851200

  18. Vaginal Discharge

    MedlinePlus

    ... also be on the lookout for symptoms of yeast infections, bacterial vaginosis and trichomoniasis, 3 infections that ... cause changes in your vaginal discharge. Signs of yeast infections White, cottage cheese-like discharge Swelling and ...

  19. A 4500-year record of large floods on the Colorado River in the Grand Canyon, Arizona

    USGS Publications Warehouse

    O'Connor, J. E.

    1994-01-01

    A sequence of flood deposits suggests at least 15 floods with peak discharges greater than 5500 m3sec-1 over the last 4500 yr. Ten floods during the last 2000-2300 yr had discharges greater than 6800 m3sec-1. One flood, 1600-1200 yr ago, had a discharge exceeding 14 000 m3sec-1, a flow rate more than twice the largest gaged flood. This record of flooding is one of the longest for a major US river and, combined with the gaged record of twentieth century floods, allows determination of the frequency and history of large floods that have affected key aspects of Colorado River geomorphology. -from Authors

  20. Paleohydraulics and hydrodynamics of Scabland floods

    NASA Technical Reports Server (NTRS)

    Baker, V. R.

    1978-01-01

    The last major episode of scabland flooding (approx. 18,000-13,000 years B.P.) left considerable high-water mark evidence in the form of: (1) eroded channel margins; (2) depositional features; (3) ice-rafter erratics; and (4) divide crossings. These were used to reconstruct maximum flood stages and water-surface gradients. Engineering hydraulic calculation procedures allowed the analyses of flood discharges and mean velocities from these data. Secondary flow phenomena, including various forms of vortices and flow separations, are considered to have been the principal erosive processes. The intense pressure and velocity gradients of vortices along the irregular channel boundaries produced the plucking-type erosion.

  1. 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.

  2. Techniques for estimating flood hydrographs for ungaged urban watersheds

    SciTech Connect

    Stricker, V.A.; Sauer, V.B.

    1982-04-01

    The Clark Method, modified slightly, was used to develop a synthetic dimensionless hydrograph that can be used to estimate flood hydrographs for ungaged urban watersheds. Application of the technique results in a typical (average) flood hydrograph for a given peak discharge. Input necessary to apply the technique is an estimate of basin lagtime and the recurrence interval peak discharge. Equations for this purpose were obtained from a recent nationwide study on flood frequency in urban watersheds. A regression equation was developed which relates flood volumes to drainage area size, basin lagtime, and peak discharge. This equation is useful where storage of floodwater may be a part of design or flood prevention. 6 refs., 17 figs., 5 tabs.

  3. Uncertainty compliant design flood estimation

    NASA Astrophysics Data System (ADS)

    Botto, A.; Ganora, D.; Laio, F.; Claps, P.

    2014-05-01

    Hydraulic infrastructures are commonly designed with reference to target values of flood peak, estimated using probabilistic techniques, such as flood frequency analysis. The application of these techniques underlies levels of uncertainty, which are sometimes quantified but normally not accounted for explicitly in the decision regarding design discharges. The present approach aims at defining a procedure which enables the definition of Uncertainty Compliant Design (UNCODE) values of flood peaks. To pursue this goal, we first demonstrate the equivalence of the Standard design based on the return period and the cost-benefit procedure, when linear cost and damage functions are used. We then use this result to assign an expected cost to estimation errors, thus setting a framework to obtain a design flood estimator which minimizes the total expected cost. This procedure properly accounts for the uncertainty which is inherent in the frequency curve estimation. Applications of the UNCODE procedure to real cases leads to remarkable displacement of the design flood from the Standard values. UNCODE estimates are systematically larger than the Standard ones, with substantial differences (up to 55%) when large return periods or short data samples are considered.

  4. Past and present floods in South Moravia

    NASA Astrophysics Data System (ADS)

    Brázdil, Rudolf; Chromá, Kateřina; Řezníčková, Ladislava; Valášek, Hubert; Dolák, Lukáš; Stachoň, Zdeněk; Soukalová, Eva; Dobrovolný, Petr

    2015-04-01

    Floods represent the most destructive natural phenomena in the Czech Republic, often causing great material damage or loss of human life. Systematic instrumental measurements of water levels in Moravia (the eastern part of the Czech Republic) started mainly in the 1880s-1890s, while for discharges it was in the 1910s-1920s. Different documentary evidence allows extension of our knowledge about floods prior the instrumental period. The paper presents long-term flood chronologies for four South Moravian rivers: the Jihlava, the Svratka, the Dyje and the Morava. Different documentary data are used to extract floods. Taxation records are of particular importance among them. Since the mid-17th century, damage to property and land (fields, meadows, pastures or gardens) entitled farmers and landowners to request a tax relief. Related documents of this administration process kept mainly in Moravian Land Archives in Brno allow to obtain detail information about floods and their impacts. Selection of floods in the instrumental period is based on calculation of N-year return period of peak water levels and/or peak discharges for selected hydrological stations of the corresponding rivers (with return period of two years and more). Final flood chronologies combine floods derived from both documentary data and hydrological measurements. Despite greater inter-decadal variability, periods of higher flood frequency are c. 1821-1850 and 1921-1950 for all four rivers; for the Dyje and Morava rivers also 1891-1900. Flood frequency fluctuations are further compared with other Central European rivers. Uncertainties in created chronologies with respect to data and methods used for compilation of long-term series and anthropogenic changes in river catchments are discussed. The study is a part of the research project "Hydrometeorological extremes in Southern Moravia derived from documentary evidence" supported by the Grant Agency of the Czech Republic, reg. no. 13-19831S.

  5. Revised techniques for estimating peak discharges from channel width in Montana

    USGS Publications Warehouse

    Parrett, Charles; Hull, J.A.; Omang, R.J.

    1987-01-01

    This study was conducted to develop new estimating equations based on channel width and the updated flood frequency curves of previous investigations. Simple regression equations for estimating peak discharges with recurrence intervals of 2, 5, 10 , 25, 50, and 100 years were developed for seven regions in Montana. The standard errors of estimates for the equations that use active channel width as the independent variables ranged from 30% to 87%. The standard errors of estimate for the equations that use bankfull width as the independent variable ranged from 34% to 92%. The smallest standard errors generally occurred in the prediction equations for the 2-yr flood, 5-yr flood, and 10-yr flood, and the largest standard errors occurred in the prediction equations for the 100-yr flood. The equations that use active channel width and the equations that use bankfull width were determined to be about equally reliable in five regions. In the West Region, the equations that use bankfull width were slightly more reliable than those based on active channel width, whereas in the East-Central Region the equations that use active channel width were slightly more reliable than those based on bankfull width. Compared with similar equations previously developed, the standard errors of estimate for the new equations are substantially smaller in three regions and substantially larger in two regions. Limitations on the use of the estimating equations include: (1) The equations are based on stable conditions of channel geometry and prevailing water and sediment discharge; (2) The measurement of channel width requires a site visit, preferably by a person with experience in the method, and involves appreciable measurement errors; (3) Reliability of results from the equations for channel widths beyond the range of definition is unknown. In spite of the limitations, the estimating equations derived in this study are considered to be as reliable as estimating equations based on basin and

  6. Fifty-year flood-inundation maps for Comayagua, Hondura

    USGS Publications Warehouse

    Kresch, David L.; Mastin, Mark C.; Olsen, T.D.

    2002-01-01

    After the devastating floods caused by Hurricane Mitch in 1998, maps of the areas and depths of the 50-year-flood inundation at 15 municipalities in Honduras were prepared as a tool for agencies involved in reconstruction and planning. This report, which is one in a series of 15, presents maps of areas in the municipality of Comayagua that would be inundated by 50-year floods on Rio Humuya and Rio Majada. Geographic Information System (GIS) coverages of the flood inundation are available on a computer in the municipality of Comayagua as part of the Municipal GIS project and on the Internet at the Flood Hazard Mapping Web page (http://mitchnts1.cr.usgs.gov/projects/floodhazard.html). These coverages allow users to view the flood inundation in much more detail than is possible using the maps in this report. Water-surface elevations for 50-year-floods on Rio Humuya and Rio Majada at Comayagua were estimated using HEC-RAS, a one-dimensional, steady-flow, step-backwater computer program. The channel and floodplain cross sections used in HEC-RAS were developed from an airborne light-detection-and-ranging (LIDAR) topographic survey of the area. The 50-year-flood discharge for Rio Humuya at Comayagua, 1,400 cubic meters per second, was estimated using a regression equation that relates the 50-year-flood discharge to drainage area and mean annual precipitation. The reasonableness of the regression discharge was evaluated by comparing it with drainage-area-adjusted 50-year-flood discharges estimated for three long-term Rio Humuya stream-gaging stations. The drainage-area-adjusted 50-year-flood discharges estimated from the gage records ranged from 946 to 1,365 cubic meters per second. Because the regression equation discharge agrees closely with the high end of the range of discharges estimated from the gaging-station records, it was used for the hydraulic modeling to ensure that the resulting 50-year-flood water-surface elevations would not be underestimated. The 50-year-flood

  7. 6. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, THE FLAP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, THE FLAP VALVES OF THE PUMPING UNITS 8, 6, AND 7 (L TO R) AND PART OF THE DISCHARGE WEIR OF THE INDIVIDUAL DISCHARGE CHAMBER OF PUMP NO. 5, LOOKING NORTHEAST. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  8. Floods on Yahara River, Lake Mendota to Lake Kegonsa, Dane County, Wisconsin, 1971

    USGS Publications Warehouse

    Holmstrom, Barry K.; Lawrence, Carl L.

    1971-01-01

    The profile and an approximate outline of the flooded area for the regional (100-year) flood has been determined for a 21.3-mile reach of the Yahara River, Dane County, Wisconsin, from State Highway 113 at the head of Lake Mendota downstream to the dam at the outlet of Lake Kegonsa. The reach consists principally of lake surface, which results in large amounts of flood-storage volume. The regional-flood profile ranges from 1.7 feet to 3.1 feet above normal low-water elevation.

  9. Flood hazard, vulnerability, and risk assessment for human life

    NASA Astrophysics Data System (ADS)

    Pan, T.; Chang, T.; Lai, J.; Hsieh, M.; Tan, Y.; Lin, Y.

    2011-12-01

    Flood risk assessment is an important issue for the countries suffering tropical cyclones and monsoon. Taiwan is located in the hot zone of typhoon tracks in the Western Pacific. There are three to five typhoons landing Taiwan every year. Typhoons and heavy rainfalls often cause inundation disaster rising with the increase of population and the development of social economy. The purpose of this study is to carry out the flood hazard, vulnerability and risk in term of human life. Based on the concept that flood risk is composed by flood hazard and vulnerability, a inundation simulation is performed to evaluate the factors of flood hazard for human life according to base flood (100-year return period). The flood depth, velocity and rising ratio are the three factors of flood hazards. Furthermore, the factors of flood vulnerability are identified in terms of human life that are classified into two main factors, residents and environment. The sub factors related to residents are the density of population and the density of vulnerable people including elders, youngers and disabled persons. The sub factors related to environment include the the number of building floors, the locations of buildings, the and distance to rescue center. The analytic hierarchy process (AHP) is adopted to determine the weights of these factors. The risk matrix is applied to show the risk from low to high based on the evaluation of flood hazards and vulnerabilities. The Tseng-Wen River watershed is selected as the case study because a serious flood was induced by Typhoon Morakot in 2009, which produced a record-breaking rainfall of 2.361mm in 48 hours in the last 50 years. The results of assessing the flood hazard, vulnerability and risk in term of human life could improve the emergency operation for flood disaster to prepare enough relief goods and materials during typhoon landing.

  10. Extending flood-frequency graphs by comparison with rainfall

    USGS Publications Warehouse

    Langbein, W.B.

    1955-01-01

    Flood discharge is the consequence of many contributing hydrologic events which may be presumed to occur fortuitously and independently, such that the probability of a given flood is the product of the probability of each independent contributing event.  Of the many factors that lead to a flood, the two most prominent are (1) storm rainfall and (2) the "antecedent conditions" (3.g., conditions of the soil encountered by the rainstorm).

  11. Bone marrow transplant - discharge

    MedlinePlus

    Transplant - bone marrow - discharge; Stem cell transplant - discharge; Hematopoietic stem cell transplant - discharge; Reduced intensity; Non-myeloablative transplant - discharge; Mini transplant - discharge; Allogenic bone marrow transplant - ...

  12. Hip fracture - discharge

    MedlinePlus

    Inter-trochanteric fracture repair - discharge; Subtrochanteric fracture repair - discharge; Femoral neck fracture repair - discharge; Trochanteric fracture repair - discharge; Hip pinning surgery - discharge

  13. Extreme coastal flood risk with sea level rise: New definitions and analysis for the contiguous US

    NASA Astrophysics Data System (ADS)

    Strauss, B.; Tebaldi, C.

    2013-12-01

    The '100-year flood' - formally defined as a flood with 0.01 annual probability - is a standard policy and regulatory benchmark for risk in the United States. However, there is increasing recognition that the traditional concept does not apply in a warming world. This is particularly the case with respect to coastal flooding, because at most locations, sea level rise is increasing the risk of flooding to any given height with each passing decade. Here we propose a flexible approach to defining extreme coastal flood height that employs different periods of interest and takes changing risks into account, while maintaining some consistency with the legacy definition. We note that in a stationary world, a 0.01 annual chance flood is equivalent to a flood with cumulative probability P(N) = 1 - 0.99^N over a period of N years. We compute P(N) for N=1 to 100 years, and then estimate the corresponding extreme coastal flood height H(N) for each period length, taking into account projected local sea level rise at each of 55 water level stations distributed throughout the contiguous US, and employing various sea level rise scenarios. In one result, employing a 50-yr interval and the high-intermediate global sea level scenario developed for the National Climate Assessment, we find that the height of extreme floods increases by an average of roughly 0.4 m or 40%, as compared to the traditional definition that assumes unchanging risk. Such discrepancies are compounded when we estimate extreme flood risk under the new approach as it would be calculated for periods beginning in future years, leading to rapid expansion of 100-year flood risk zones.

  14. 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.

  15. Amazon flood wave hydraulics

    NASA Astrophysics Data System (ADS)

    Trigg, Mark A.; Wilson, Matthew D.; Bates, Paul D.; Horritt, Matthew S.; Alsdorf, Douglas E.; Forsberg, Bruce R.; Vega, Maria C.

    2009-07-01

    SummaryA bathymetric survey of 575 km of the central Amazon River and one of its tributaries, the Purus, are combined with gauged data to characterise the Amazon flood wave, and for hydraulic modelling of the main channel for the period June 1995-March 1997 with the LISFLOOD-FP and HEC-RAS hydraulic models. Our investigations show that the Amazon flood wave is subcritical and diffusive in character and, due to shallow bed slopes, backwater conditions control significant reach lengths and are present for low and high water states. Comparison of the different models shows that it is necessary to include at least the diffusion term in any model, and the RMSE error in predicted water elevation at all cross sections introduced by ignoring the acceleration and advection terms is of the order of 0.02-0.03 m. The use of a wide rectangular channel approximation introduces an error of 0.10-0.15 m on the predicted water levels. Reducing the bathymetry to a simple bed slope and with mean cross section only, introduces an error in the order of 0.5 m. These results show that when compared to the mean annual amplitude of the Amazon flood wave of 11-12 m, water levels are relatively insensitive to the bathymetry of the channel model. The implication for remote sensing studies of the central Amazon channel, such as those proposed with the Surface Water and Ocean Topography mission (SWOT), is that even relatively crude assumptions regarding the channel bathymetry will be valid in order to derive discharge from water surface slope of the main channel, as long as the mean channel area is approximately correct.

  16. Uncertainties of the global-to-regional temperature and precipitation simulations in CMIP5 models for past and future 100 years

    NASA Astrophysics Data System (ADS)

    Zhao, Lilong; Xu, Jianjun; Powell, Alfred M.; Jiang, Zhihong

    2015-10-01

    Global-to-regional surface temperature and precipitation trends are examined based on the CMIP5 model 100 years of historical simulations and another future 100 years following the Representative Concentration Pathway (RCP) emission scenario projection. Different from the ensemble mean approach in the previous studies, the probabilistic multimodal ensemble prediction with Gaussian fitting is used to generate probabilistic simulations. The results show that the averaged precipitation increases slightly with global warming, but the response is not globally uniform. Both historical model simulations and the RCP emission scenario projections suffer from large uncertainties in the selected models and the geographic distribution. The spatial distribution of spreads among the multimodal scenario projections is similar to that in the historical simulations, except the magnitude of spread sharply increases and the region expands equatorward and poleward in surface temperature and precipitation, respectively.

  17. Use of indexed historical floods in flood frequency estimation with Fuzzy Bayesian methods

    NASA Astrophysics Data System (ADS)

    Salinas, Jose; Viglione, Alberto; Kiss, Andrea; Bloeschl, Guenter

    2015-04-01

    Efforts of the historical environmental extremes community during the last decades have resulted in the existence of long time series of floods, for example in Central Europe and the Mediterranean region, which in some cases range longer than 500 years in the past. In most of the cases the flood time series are presented in terms of indices, representing a combination of socio-economic indicators for the flood impact, e.g. economic damage, flood duration and extension, ... In hydrological engineering, historical floods are very useful because they give additional information which will reduce the uncertainty in estimates of discharges with low annual exceedance probabilities, i.e. with high return periods. In order to use the historical floods in formal flood frequency analysis, the precise value of the peak discharges would ideally be known, but as commented, they are most usually given in term of indices. This work presents a novel method on how to obtain a prior distribution for the parameters of the annual peak discharges distribution from indexed historical floods time series. The prior distribution is incorporated in the flood frequency estimation via Bayesian methods (see e.g. Viglione et al., 2013) in order to reduce the uncertainties in the design flood estimates. The historical data used is subject to a high degree of uncertainty and unpreciseness. In this sense, a framework is presented where the discharge thresholds between flood indices are modeled as fuzzy numbers. These fuzzy thresholds will define a fuzzy prior distribution, which will requires to apply Fuzzy Bayesian Inference (Viertl, 2008ab) to obtain fuzzy credibility intervals for the design floods. Viertl, R. (2008a) Foundations of Fuzzy Bayesian Inference, Journal of Uncertain Systems, 2, 187-191. Viertl, R. (2008b) Fuzzy Bayesian Inference. In: Soft Methods For Handling Variability And Imprecision. Advances In Soft Computing. Vol. 48. Springer-Verlag Berlin, pp 10-15. Viglione, A., R. Merz

  18. 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.

  19. Fifty-year flood-inundation maps for Choluteca, Honduras

    USGS Publications Warehouse

    Kresch, David L.; Mastin, Mark C.; Olsen, T.D.

    2002-01-01

    After the devastating floods caused by Hurricane Mitch in 1998, maps of the areas and depths of 50-year-flood inundation at 15 municipalities in Honduras were prepared as a tool for agencies involved in reconstruction and planning. This report, which is one in a series of 15, presents maps of areas in the municipality of Choluteca that would be inundated by 50-year floods on Rio Choluteca and Rio Iztoca. Geographic Information System (GIS) coverages of the flood inundation are available on a computer in the municipality of Choluteca as part of the Municipal GIS project and on the Internet at the Flood Hazard Mapping Web page (http://mitchnts1.cr.usgs.gov/projects/floodhazard.html). These coverages allow users to view the flood inundation in much more detail than is possible using the maps in this report. Water-surface elevations for 50-year-floods on Rio Choluteca and Rio Iztoca at Choluteca were estimated using HEC-RAS, a one-dimensional, steady-flow, step-backwater computer program. The channel and floodplain cross sections used in HEC-RAS were developed from an airborne light-detection-and-ranging (LIDAR) topographic survey of the area. The estimated 50-year-flood discharge for Rio Choluteca at Choluteca is 4,620 cubic meters per second, which is the drainage-area-adjusted weighted-average of two independently estimated 50-year-flood discharges for the gaging station Rio Choluteca en Puente Choluteca. One discharge, 4,913 cubic meters per second, was estimated from a frequency analysis of the 17 years of peak discharge record for the gage, and the other, 2,650 cubic meters per second, was estimated from a regression equation that relates the 50-year-flood discharge to drainage area and mean annual precipitation. The weighted-average of the two discharges at the gage is 4,530 cubic meters per second. The 50-year-flood discharge for the study area reach of Rio Choluteca was estimated by multiplying the weighted discharge at the gage by the ratio of the drainage

  20. 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

  1. Hydraulic Reconstructions of Outburst Floods on Earth and Mars

    NASA Astrophysics Data System (ADS)

    Lapotre, M. G. A.; Lamb, M. P.

    2014-12-01

    Large outburst floods on Earth and Mars have carved bedrock canyons in basalt that often have steep sidewalls and amphitheater heads, suggesting erosion by waterfall retreat and block toppling. Two paleohydraulic methods are typically used to reconstruct flood discharges. The first is based on the discharge required to move sediment, which requires rare grain-size data and is necessarily a lower bound. The second assumes bedrock canyons are entirely inundated, which likely greatly overestimates the discharge of canyon carving floods. Here we explore a third hypothesis that canyon width is an indicator of flood discharge. For example, we expect that for large floods relative to the canyon width, the canyon will tend to widen as water spills over and erodes the canyon sidewalls. In contrast, small floods, relative to the canyon size will tend to focus flow into the canyon head, resulting in a narrowing canyon. To test this hypothesis, we need data on how outburst floods focus water into canyons across a wide range of canyon and flood sizes. To fill this data gap, we performed a series of numerical simulations solving the 2D depth-averaged shallow water equations for turbulent flow. We analyzed the effect of five non-dimensional parameters on the shear stress and discharge distributions around head and sidewalls of canyons of different sizes. The Froude number of the flood has the greatest effect on the distribution of shear stresses and discharges around the canyon rim; higher Froude numbers lead to less convergence of the flow towards the canyon, and thus to lower shear stresses (and discharges) on the sides of the canyon. Simulation results show that canyons of constant width were likely carved by floods within a relatively narrow range of discharges. The range of discharges is sensitive to the Froude number and size of blocks that are toppled at the canyon head, both of which can be estimated from field and remotely sensed data. Example applications on Earth and

  2. 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.

  3. Angina - discharge

    MedlinePlus

    ... bypass surgery - minimally invasive - discharge Heart disease - risk factors High ... of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed ...

  4. Flood of July 21, 1975 in Mercer County, New Jersey

    USGS Publications Warehouse

    Stankowski, Stephen J.; Schopp, Robert D.; Velnich, Anthony J.

    1975-01-01

    Intense rainfall during the evening of July 20 and early morning hours of July 21, 1975 caused flooding of unprecedented magnitude in highly urbanized Mercer County, New Jersey. Over 6 inches (152 millimetres) of rainfall was recorded during a 10-hour period at Trenton, the capital of New Jersey. No lives were lost but damages to highways and bridges, to industrial, business, and residential buildings, to farmlands and crops, and to water supply systems were severe. This report illustrates the magnitude of the flood and provides hydrologic data needed for planning and design to control or lessen damages from future floods. It includes discussions of the antecedent conditions and meteorological aspects of the storm; a description of the flood and comparison to previous floods; a summary of flood stages and discharges; a discussion of flood frequency; and photomosaics which show inundated areas. More than 200 high-water marks are described as to location and elevation above mean sea level.

  5. The August 2002 flood in Prague

    NASA Astrophysics Data System (ADS)

    Marešová, I.; Mareš, K.; Vogel, T.

    2003-04-01

    In August 2002 the Czech Republic was struck by the largest flood in its history with the destruction of more than 1000 houses, tens of km of roads and dozens of bridges. The reconstruction of the country will take more than 2 years. The catastrophic flood was caused by two rainfall events following rapidly one after the other. Saturated basins and full river channels after the first rainstorm caused the highest water stages and discharges ever recorded in a number of river profiles in the country. In Prague two floods coincided, with run-off from the Vltava river cascade meeting the flood wave from the Berounka river. The floods in the Czech Republic and in Prague are still being assessed. The water level of this flood surpassed the flood marks from the last century by 70 - 100 cm. At the present time the value of the discharge in Prague is evaluated as 5200 {m^3 s-1}, whereas {Q100} is considered to be 3700 {m3s-1}. The Vltava in Prague is a trained river, protected by embankments ({Q50} and {Q20}) and protective dykes ({Q100} and {Q20}). In addition, a significant role in the flood protection of Prague was played by the manipulation of the dams of the Vltava river cascade, and by a new element - mobile walls protecting the historically valuable Old Town of Prague on the right bank of the Vltava. A conception for improving the flood protection of Prague was ready in the form of a design at the end of the {20th} century. It was ready for use in 2000, when the way in which it should be built was also checked. The calculation for the level of the mobile wall was based on mathematical modeling of the course of a hundred year flood in Prague. However, the mobile walls were constructed 50 cm higher than the calculated flood levels. During the flood, the water levels reached about 20 cm, and in some places only about 5 cm, below the top of the mobile walls, but the mobile walls were not overtopped. Mobile walls were not used on the left bank of the Prague city center

  6. Floods, flood control, and bottomland vegetation

    USGS Publications Warehouse

    Friedman, Jonathan M.; Auble, Gregor T.

    2000-01-01

    Bottomland plant communities are typically dominated by the effects of floods. Floods create the surfaces on which plants become established, transport seeds and nutrients, and remove establish plants. Floods provide a moisture subsidy that allows development of bottomland forests in arid regions and produce anoxic soils, which can control bottomland plant distribution in humid regions. Repeated flooding produces a mosaic of patches of different age, sediment texture, and inundation duration; this mosaic fosters high species richness.

  7. Analysis the flash floods occurred in the South Tyne river watershed (United Kingdom) on the 17th of July 2007

    NASA Astrophysics Data System (ADS)

    Bain, V.; Milan, D.; Preciso, E.; Gaume, E.

    2009-04-01

    On the 17th, 19th and 23rd of July 2007, a series of local thunderstorms induced flash floods in the upper part of the South Tyne river in Northumberland, a rural area located near the border between England and Scotland. These events led to moderate damages in the villages and losses of livestock in local farms. They were shadowed in comparison to the widespread lowland floods that occurred throughout the UK during the same period but were nevertheless extreme events for the region. One of the affected streams, the Thinhope Burn, has been surveyed by the University of Gloucestershire during recent years. It is an active river from a geomorphological point of view. A survey conducted after the 2007 flood revealed that many of the boulders along the banks of the river, which had been deposited 50 to 100 years before, had been displaced, indicating a high return period for the flood (see EGU abstract EGU2008-A-04713). A complementary survey was conducted in July 2008 with the objective of gathering information on the discharges, the rainfall amounts and the active runoff processes. 14 cross-sections were surveyed, pictures were collected enabling a validation of peak discharge estimates, 5 witnesses were interviewed and additional rainfall data and geomorphological evidence were collected. This survey revealed that the peak discharges exceeded 5 m3/s/km2 in the most affected areas. Unfortunately, no rainfall measurements are available that would enable further analysis, including the computation of runoff rates. Nevertheless, witness accounts and field observations give a good insight into the hydrological processes indicating a significant initial storage capacity of the peat layer covering the affected watersheds. Concerning the boulders, the field observations suggest surprising and unexplained transport processes. Blocks of up to one meter diameter were displaced over short distances and deposited on the river banks without any sign of established debris flow, as

  8. 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.

  9. Flood estimates for ungaged streams in Glacier and Yellowstone National Parks, Montana

    USGS Publications Warehouse

    Omang, R.J.; Parrett, Charles; Hull, J.A.

    1983-01-01

    Estimates of 100-year discharges were made at 59 sites in Glacier National Park and 21 sites in Yellowstone National Park to assist the National Park Services in quantifying stream inflow and outflow in the Parks. The estimates were made using regression equations previously developed for Montana. The resulting 100-year discharges are listed in tables; the discharges ranged from 260 to 53,200 cu ft/s in Glacier National Park and from 110 to 27,900 cu ft/s in Yellowstone National Park. (USGS)

  10. Fifty-year flood-inundation maps for Nacaome, Honduras

    USGS Publications Warehouse

    Kresch, David L.; Mastin, M.C.; Olsen, T.D.

    2002-01-01

    After the devastating floods caused by Hurricane Mitch in 1998, maps of the areas and depths of 50-year-flood inundation at 15 municipalities in Honduras were prepared as a tool for agencies involved in reconstruction and planning. This report, which is one in a series of 15, presents maps of areas in the municipality of Nacaome that would be inundated by 50-year floods on Rio Nacaome, Rio Grande, and Rio Guacirope. Geographic Information System (GIS) coverages of the flood inundation are available on a computer in the municipality of Nacaome as part of the Municipal GIS project and on the Internet at the Flood Hazard Mapping Web page (http://mitchnts1.cr.usgs.gov/projects/floodhazard.html). These coverages allow users to view the flood inundation in much more detail than is possible using the maps in this report. Water-surface elevations for 50-year-floods on Rio Nacaome, Rio Grande, and Rio Guacirope at Nacaome were computed using HEC-RAS, a one-dimensional, steady-flow, step-backwater computer program. The channel and floodplain cross sections used in HEC-RAS were developed from an airborne light-detection-and-ranging (LIDAR) topographic survey of the area and ground surveys at two bridges. The estimated 50-year-flood discharge for Rio Nacaome at Nacaome, 5,040 cubic meters per second, was computed as the drainage-area-adjusted weighted average of two independently estimated 50-year-flood discharges for the gaging station Rio Nacaome en Las Mercedes, located about 13 kilometers upstream from Nacaome. One of the discharges, 4,549 cubic meters per second, was estimated from a frequency analysis of the 16 years of peak-discharge record for the gage, and the other, 1,922 cubic meters per second, was estimated from a regression equation that relates the 50-year-flood discharge to drainage area and mean annual precipitation. The weighted-average of the two discharges is 3,770 cubic meters per second. The 50-year-flood discharges for Rio Grande, 3,890 cubic meters per

  11. Sea-Level Rise and Flood Potential along the California Coast

    NASA Astrophysics Data System (ADS)

    Delepine, Q.; Leung, C.

    2013-12-01

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

  12. Discharging patients.

    PubMed

    Causey, Amy

    2016-06-22

    What was the nature of the CPD activity and/or practice-related feedback and/or event or experience in your practice? The CPD article discussed the importance of effective planning when discharging patients from acute care hospitals. It emphasised the benefit of early assessment and planning, and outlined the essential principles that should be followed when discharging a patient. PMID:27332612

  13. Proper estimation of hydrological parameters from flood forecasting aspects

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    The hydrological parameters of a flood forecasting model are normally calibrated based on an entire hydrograph of past flood events by means of an error assessment function such as mean square error and relative error. However, the specific parts of a hydrograph, i.e., maximum discharge and rising parts, are particularly important for practical flood forecasting in the sense that underestimation may lead to a more dangerous situation due to delay in flood prevention and evacuation activities. We conducted numerical experiments to find the most proper parameter set for practical flood forecasting without underestimation in order to develop an error assessment method for calibration appropriate for flood forecasting. A distributed hydrological model developed in Public Works Research Institute (PWRI) in Japan was applied to fifteen past floods in the Gokase River basin of 1,820km2 in Japan. The model with gridded two-layer tanks for the entire target river basin included hydrological parameters, such as hydraulic conductivity, surface roughness and runoff coefficient, which were set according to land-use and soil-type distributions. Global data sets, e.g., Global Map and Digital Soil Map of the World (DSMW), were employed as input data for elevation, land use and soil type. The values of fourteen types of parameters were evenly sampled with 10,001 patterns of parameter sets determined by the Latin Hypercube Sampling within the search range of each parameter. Although the best reproduced case showed a high Nash-Sutcliffe Efficiency of 0.9 for all flood events, the maximum discharge was underestimated in many flood cases. Therefore, two conditions, which were non-underestimation in the maximum discharge and rising parts of a hydrograph, were added in calibration as the flood forecasting aptitudes. The cases with non-underestimation in the maximum discharge and rising parts of the hydrograph also showed a high Nash-Sutcliffe Efficiency of 0.9 except two flood cases

  14. Basin Overflow Floods on Mars

    NASA Astrophysics Data System (ADS)

    Irwin, R. P.

    2006-12-01

    On Earth, the most intense recognized historical and paleofloods have been ice dambursts or overflows of large basins, often initiated by abundant runoff or meltwater from the contributing watersheds. Many impact craters and other basins also overflowed in the Martian cratered highlands, and some of their incised outlet valleys similarly record evidence of erosive floods. Otherwise, the commonly small, enclosed watersheds on Mars contain poorly developed valley networks and relatively simple depositional landforms, which record little evidence of intense (by terrestrial standards) meteorological floods. For these reasons, basin overflows may have been disproportionately important mechanisms for incision of large valleys on Mars. Many of the Martian outflow channels head in topographic settings that favored ponding, including large canyons, impact or intercrater basins, chaotic terrain basins, and grabens. This topography may have accumulated somewhat slower groundwater discharges from the subsurface to support peak channel discharges of 106-108 m3/s. To yield a discharge of 106, 107, and 108 m3/s from a dam failure with a width/depth ratio of 5, the model predicts that a breach of ~100, 250, and 640 m, respectively, must form rapidly with respect to the decline of lake level. Terrestrial damburst floods have not exceeded ~106 m3/s for earthen dams and ~107 m3/s for ice dams, but brecciation of the Martian surface by impact cratering may have allowed larger damburst failures, whereas solid bedrock was exposed at shallower depths in the terrestrial examples. Moreover, many of the Martian basins were much larger than enclosed continental basins on Earth, so long-lived overflows may have facilitated entrenchment of deeper channels. Some large, mid-latitude basins overflowed to carve Ma'adim Vallis and the Uzboi-Ladon-Margaritifer Valles system, which are similar in scale to the terrestrial Grand Canyon but record much larger formative discharges. Models of damburst

  15. Celebrating 100 Years of Flight.

    ERIC Educational Resources Information Center

    Reese, Susan

    2003-01-01

    In honor of the Wright brothers' first flight, the article profiles aviation and aerospace technology programs that are training workers in aviation safety and explorations. Looks at programs from Eastern New Mexico University-Roswell, Pima Community College, and Olathe Northwest High School. (JOW)

  16. [Dermatitis artefacta 100 years ago].

    PubMed

    Heras-Mendaza, F

    2009-10-01

    In 1909, the Spanish dermatologist Juan de Azúa published a study of the main features of skin lesions in dermatitis artefacta. In the article, he paid particular attention to the psychological state of these patients, their family situation, and what they were hoping to gain with pathomimicry. Azúa directly confronted the patients with the diagnosis, which he demonstrated by applying an occlusive dressing. Written in a literary style typical of the times, the article includes the subjective impressions of Azúa, through which he manages to transmit a much more realistic image of these patients than that portrayed with the sterile language we tend to use in current medical literature. PMID:19775543

  17. 100 years of Philips Research

    NASA Astrophysics Data System (ADS)

    van Delft, Dirk

    2014-03-01

    On Thursday 23 October 1913, a Dutch newspaper published the following advertisement: Hiring: A capable young scientist with a doctorate in physics. Must be a good experimenter. Letters containing information on age, life history and references may be submitted to Philips in Eindhoven. Two days later, a candidate applied: Gilles Holst. At that time, Holst was working in Leiden as an assistant to Heike Kamerlingh Onnes, a recent Nobel Prize winner.

  18. 100 Years of Reality Learning

    ERIC Educational Resources Information Center

    Zimpher, Nancy L.; Wright Ron, D.

    2006-01-01

    One may have heard of reality TV, but what about reality learning? The latter is probably a term one hasn't seen much, although it is in many ways a clearer and more concise name for a concept that in 2006 marks its 100th anniversary: cooperative education, or "co-op." Co-op, a break-through idea pioneered at the University of Cincinnati by Herman…

  19. Hydrologic versus geomorphic drivers of trends in flood hazard

    NASA Astrophysics Data System (ADS)

    Slater, Louise J.; Bliss Singer, Michael; Kirchner, James W.

    2016-04-01

    Flooding is a major threat to lives and infrastructure, yet trends in flood hazard are poorly understood. The capacity of river channels to convey flood flows is typically assumed to be stationary, so changes in flood frequency are thought to be driven primarily by trends in streamflow. However, changes in channel capacity will also modify flood hazard, even if the flow frequency distribution does not change. We developed new methods for separately quantifying how trends in both streamflow and channel capacity have affected flood frequency at gauging sites across the United States. Using daily discharge records and manual field measurements of channel cross-sectional geometry for USGS gauging stations that have defined flood stages (water levels), we present novel methods for measuring long-term trends in channel capacity of gauged rivers, and for quantifying how they affect overbank flood frequency. We apply these methods to 401 U.S. rivers and detect measurable trends in flood hazard linked to changes in channel capacity and/or the frequency of high flows. Flood frequency is generally nonstationary across these 401 U.S. rivers, with increasing flood hazard at a statistically significant majority of sites. Changes in flood hazard driven by channel capacity are smaller, but more numerous, than those driven by streamflow, with a slight tendency to compensate for streamflow changes. Our results demonstrate that accurately quantifying changes in flood hazard requires accounting separately for trends in both streamflow and channel capacity, or using water levels directly. They also show that channel capacity trends may have unforeseen consequences for flood management and for estimating flood insurance costs. Slater, L. J., M. B. Singer, and J. W. Kirchner (2015), Hydrologic versus geomorphic drivers of trends in flood hazard, Geophys. Res. Lett., 42, 370-376, doi:10.1002/2014GL062482.

  20. Climate-Driven Trends in the Occurrence of Major Floods in North America and Europe

    NASA Astrophysics Data System (ADS)

    Renard, B.; Hodgkins, G. A.; Whitfield, P. H.; Burn, D. H.; Hannaford, J.; Stahl, K.; Fleig, A. K.; Madsen, H.; Mediero, L.; Korhonen, J.; Murphy, C.; Crochet, P.; Wilson, D.

    2014-12-01

    Every year floods cause much damage around the world. It is important to understand historical changes in major floods to help inform how flood frequency may change in the future. To date, however, there is very limited evidence of past changes in major-flood magnitude and occurrence (exceeding 25, 50, and 100 year return-period thresholds). Many studies have analyzed annual-maximum flood trends but they have often not differentiated between trends influenced by human catchment alterations and those caused by climatic changes. Here we present the first intercontinental assessment of historical climate-driven trends in major-flood occurrence using many diverse but minimally altered catchments. There is no compelling evidence for consistent increases in major-flood occurrence across this very large domain. Flood occurrence at 1206 gauges increased from 1961 to 2010 but not significantly, driven primarily by European increases. There also were non-significant increases in flood occurrence at 322 gauges from 1931 to 2010, but this time driven primarily by North American increases. Flood occurrence both increased and decreased for different subgroups of gauges (a few were significant changes) differentiated by catchment size, type of climate, flood threshold, and period of record. Past changes in major-flood occurrence are complex and future changes will be likewise. International hydrologic networks containing minimally altered catchments will play a key role in understanding these complexities for both historical and future climatic conditions.

  1. Magnitude and frequency of floods in Alabama

    USGS Publications Warehouse

    Atkins, J. Brian

    1996-01-01

    Methods of estimating flood magnitudes for recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years are described for rural streams in Alabama that are not affected by regulation or urbanization. Flood-frequency characteristics are presented for 198 gaging stations in Alabama having 10 or more years of record through September 1991, that are used in the regional analysis. Regression relations were developed using generalized least-squares regression techniques to estimate flood magnitude and frequency on ungaged streams as a function of the drainage area of a basin. Sites on gaged streams should be weighted with gaging station data that are presented in the report. Graphical relations of peak discharges to drainage areas are also presented for sites along the Alabama, Black Warrior, Cahaba, Choctawhatchee, Conecub, and Tombigbee Rivers. Equations for estimating flood magnitudes on ungaged urban streams (taken from a previous report) that use drainage area and percentage of impervious cover as independent variables also are given.

  2. Flooding and Schools

    ERIC Educational Resources Information Center

    National Clearinghouse for Educational Facilities, 2011

    2011-01-01

    According to the Federal Emergency Management Agency, flooding is the nation's most common natural disaster. Some floods develop slowly during an extended period of rain or in a warming trend following a heavy snow. Flash floods can occur quickly, without any visible sign of rain. Catastrophic floods are associated with burst dams and levees,…

  3. Floods of September 2010 in Southern Minnesota

    USGS Publications Warehouse

    Ellison, Christopher A.; Sanocki, Chris A.; Lorenz, David L.; Mitton, Gregory B.; Kruse, Gregory A.

    2011-01-01

    During September 22-24, 2010, heavy rainfall ranging from 3 inches to more than 10 inches caused severe flooding across southern Minnesota. The floods were exacerbated by wet antecedent conditions, where summer rainfall totals were as high as 20 inches, exceeding the historical average by more than 4 inches. Widespread flooding that occurred as a result of the heavy rainfall caused evacuations of hundreds of residents, and damages in excess of 64 million dollars to residences, businesses, and infrastructure. In all, 21 counties in southern Minnesota were declared Federal disaster areas. Peak-of-record streamflows were recorded at nine U.S. Geological Survey and three Minnesota Department of Natural Resources streamgages as a result of the heavy rainfall. Flood-peak gage heights, peak streamflows, and annual exceedance probabilities were tabulated for 27 U.S. Geological Survey and 5 Minnesota Department of Natural Resources streamgages and 5 ungaged sites. Flood-peak streamflows in 2010 had annual exceedance probabilities estimated to be less than 0.2 percent (recurrence interval greater than 500 years) at 7 streamgages and less than 1 percent (recurrence interval greater than 100 years) at 5 streamgages and 4 ungaged sites. High-water marks were identified and tabulated for the most severely affected communities of Faribault along the Cannon and Straight Rivers, Owatonna along the Straight River and Maple Creek, Pine Island along the North Branch and Middle Fork Zumbro River, and Zumbro Falls along the Zumbro River. The nearby communities of Hammond, Henderson, Millville, Oronoco, Pipestone, and Rapidan also received extensive flooding and damage but were not surveyed for high-water marks. Flood-peak inundation maps and water-surface profiles for the four most severely affected communities were constructed in a geographic information system by combining high-water-mark data with the highest resolution digital elevation model data available. The flood maps and

  4. Flood of June 1972: Genesee River at Portageville, New York

    USGS Publications Warehouse

    Schneider, W.J.; Swallow, L.A.

    1972-01-01

    In June 1972, tropical storm Agnes caused sever flooding in Pennsylvania and southern New York. The flood, on many major streams were the highest known since the river valleys were settled. Maximum discharges were as much as twice the discharge of a 50-year flood. In southern New York, large areas in Corning, Elmire, Wellsville, Salamanca, and in many smaller communities were inundated to depths of several feet. Levels of all of the Finger Lakes were higher than any previously recorded, and extensive flooding of lakeside properties resulted. The extent of flooding shown on the map was delineated by the U.S. Geological Survey from earlier photography and limited field survey. The investigation was conducted in cooperation with the State of New York and the U.S. Army Corps of Engineers.

  5. Flood of June 1972: Genesee River near Belfast, New York

    USGS Publications Warehouse

    Wagner, L.A.; Hamecher, P.H.

    1972-01-01

    In June 1972, tropical storm Agnes caused sever flooding in Pennsylvania and southern New York. The flood, on many major streams were the highest known since the river valleys were settled. Maximum discharges were as much as twice the discharge of a 50-year flood. In southern New York, large areas in Corning, Elmire, Wellsville, Salamanca, and in many smaller communities were inundated to depths of several feet. Levels of all of the Finger Lakes were higher than any previously recorded, and extensive flooding of lakeside properties resulted. The extent of flooding shown on the map was delineated by the U.S. Geological Survey from earlier photography and limited field survey. The investigation was conducted in cooperation with the State of New York and the U.S. Army Corps of Engineers.

  6. Flood of June 1972: Genesee River at Belmont, New York

    USGS Publications Warehouse

    Wagner, L.A.; Hamecher, P.H.

    1972-01-01

    In June 1972, tropical storm Agnes caused sever flooding in Pennsylvania and southern New York. The flood, on many major streams were the highest known since the river valleys were settled. Maximum discharges were as much as twice the discharge of a 50-year flood. In southern New York, large areas in Corning, Elmire, Wellsville, Salamanca, and in many smaller communities were inundated to depths of several feet. Levels of all of the Finger Lakes were higher than any previously recorded, and extensive flooding of lakeside properties resulted. The extent of flooding shown on the map was delineated by the U.S. Geological Survey from earlier photography and limited field survey. The investigation was conducted in cooperation with the State of New York and the U.S. Army Corps of Engineers.

  7. Flood of June 1972: Genesee River at Fillmore, New York

    USGS Publications Warehouse

    Swallow, L.A.; Embree, W.N.

    1972-01-01

    In June 1972, tropical storm Agnes caused sever flooding in Pennsylvania and southern New York. The flood, on many major streams were the highest known since the river valleys were settled. Maximum discharges were as much as twice the discharge of a 50-year flood. In southern New York, large areas in Corning, Elmire, Wellsville, Salamanca, and in many smaller communities were inundated to depths of several feet. Levels of all of the Finger Lakes were higher than any previously recorded, and extensive flooding of lakeside properties resulted. The extent of flooding shown on the map was delineated by the U.S. Geological Survey from earlier photography and limited field survey. The investigation was conducted in cooperation with the State of New York and the U.S. Army Corps of Engineers.

  8. Flood of June 1972: Genesee River at Houghton, New York

    USGS Publications Warehouse

    Swallow, L.A.; Embree, W.N.

    1972-01-01

    In June 1972, tropical storm Agnes caused sever flooding in Pennsylvania and southern New York. The flood, on many major streams were the highest known since the river valleys were settled. Maximum discharges were as much as twice the discharge of a 50-year flood. In southern New York, large areas in Corning, Elmire, Wellsville, Salamanca, and in many smaller communities were inundated to depths of several feet. Levels of all of the Finger Lakes were higher than any previously recorded, and extensive flooding of lakeside properties resulted. The extent of flooding shown on the map was delineated by the U.S. Geological Survey from earlier photography and limited field survey. The investigation was conducted in cooperation with the State of New York and the U.S. Army Corps of Engineers.

  9. Characterization of remarkable floods in France, a transdisciplinary approach applied on generalized floods of January 1910

    NASA Astrophysics Data System (ADS)

    Boudou, Martin; Lang, Michel; Vinet, Freddy; Coeur, Denis

    2014-05-01

    emphasize one flood typology or one flood dynamic (for example flash floods are often over-represented than slow dynamic floods in existing databases). Thus, the selected criteria have to introduce a general overview of flooding risk in France by integrating all typologies: storm surges, torrential floods, rising groundwater level and resulting to flood, etc. The methodology developed for the evaluation grid is inspired by several scientific works related to historical hydrology (Bradzil, 2006; Benito et al., 2004) or extreme floods classification (Kundzewics et al. 2013; Garnier E., 2005). The referenced information are mainly issued from investigations realized for the PFRA (archives, local data),from internet databases on flooding disasters, and from a complementary bibliography (some scientists such as Maurice Pardé a geographer who largely documented French floods during the 20th century). The proposed classification relies on three main axes. Each axis is associated to a set of criteria, each one related to a score (from 0.5 to 4 points), and pointing out a final remarkability score. • The flood intensity characterizing the flood's hazard level. It is composed of the submersion duration, important to valorize floods with slow dynamics as flooding from groundwater, the event peak discharge's return period, and the presence of factors increasing significantly the hazard level (dykes breaks, log jam, sediment transport…) • The flood severity focuses on economic damages, social and political repercussions, media coverage of the event, fatalities number or eventual flood warning failures. Analyzing the flood consequences is essential in order to evaluate the vulnerability of society at disaster date. • The spatial extension of the flood, which contributes complementary information to the two first axes. The evaluation grid was tested and applied on the sample of 176 remarkable events. Around twenty events (from 1856 to 2010) come out with a high remarkability rate

  10. Inland Flood Hazards

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen E.

    2000-07-01

    A comprehensive, interdisciplinary review of issues related to inland flood hazards, this important work addresses physical controls on flooding, flood processes and effects, and responses to flooding, from the perspectives of human, aquatic, and riparian communities. The contributors, recognized experts in their fields, draw on examples and case studies of inland flood hazards from around the world. The volume is unique in that it addresses how the nonoccurrence of floods, in association with flow regulation and other human manipulation of river systems, may create hazards for aquatic and riparian communities. This book will be a valuable resource for all professionals concerned with inland flood hazards.

  11. Floods of September 16, 1975 in the Tallaboa Valley, Puerto Rico

    USGS Publications Warehouse

    Johnson, Karl G.

    1981-01-01

    The most severe flood since 1928 inundated the Rio Tallaboa Valley on the south coast of Puerto Rico on September 16, 1975. Peak discharge was about 666 cubic meters per second. The flood has an estimated recurrence interval of 20 years. The data provided in the report can be used in making rational decisions in formulating effective flood-plain regulations that would minimize flood problems in the Tallaboa Valley. (USGS)

  12. Flood of July 1-5, 1978 on the Kickapoo River, southwestern Wisconsin

    USGS Publications Warehouse

    Hughes, Peter E.; Hannuksela, J.S.; Danchuk, W.J.

    1981-01-01

    The Kickapoo River valley in southwestern Wisconsin had a devastating flood ($10 million estimated damages) during July 1-5, 1978. The flash flooding was caused by intense storms on June 30 through July 2. Total rainfall accumulation ranged from 5.8 inches near Ontario to 9.5 inches at La Farge. The resulting flood equaled or exceeded the largest ones recorded since the 1850 's and equaled or exceeded the 100-year flood frequency at the U.S. Geological Survey 's streamflow gages at La Farge and Steuben. Elevation and delineation of the flood are shown on photo mosaics developed from black and white aerial photographs. The 100-mile reach from Wauzeka to Wilton is shown. A summary of the storm conditions causing the flood and an analysis of the rainfall totals, as prepared by the Wisconsin Geological and Natural History Survey, are also included. (USGS)

  13. Fifty-year flood-inundation maps for Juticalpa, Honduras

    USGS Publications Warehouse

    Kresch, David L.; Mastin, M.C.; Olsen, T.D.

    2002-01-01

    After the devastating floods caused by Hurricane Mitch in 1998, maps of the areas and depths of 50-year-flood inundation at 15 municipalities in Honduras were prepared as a tool for agencies involved in reconstruction and planning. This report, which is one in a series of 15, presents maps of areas in the municipality of Juticalpa that would be inundated by a 50-year flood of Rio Juticalpa. Geographic Information System (GIS) coverages of the flood inundation are available on a computer in the municipality of Juticalpa as part of the Municipal GIS project and on the Internet at the Flood Hazard Mapping Web page (http://mitchnts1.cr.usgs.gov/projects/floodhazard.html). These coverages allow users to view the flood inundation in much more detail than is possible using the maps in this report. Water-surface elevations for a 50-year-flood on Rio Juticalpa at Juticalpa were estimated using HEC-RAS, a one-dimensional, steady-flow, step-backwater computer program. The channel and floodplain cross sections used in HEC-RAS were developed from an airborne light-detection-and-ranging (LIDAR) topographic survey of the area. The estimated 50-year-flood discharge for Rio Juticalpa at Juticalpa, 1,360 cubic meters per second, was computed as the drainage-area-adjusted weighted average of two independently estimated 50-year-flood discharges for the gaging station Rio Juticalpa en El Torito, located about 2 kilometers upstream from Juticalpa. One discharge, 1,551 cubic meters per second, was estimated from a frequency analysis of the 33 years of peak-discharge record for the gage, and the other, 486 cubic meters per second, was estimated from a regression equation that relates the 50-year-flood discharge to drainage area and mean annual precipitation. The weighted-average of the two discharges at the gage is 1,310 cubic meters per second. The 50-year flood discharge for the study area reach of Rio Juticalpa was estimated by multiplying the weighted discharge at the gage by the

  14. Floods in the Skagit River basin, Washington

    USGS Publications Warehouse

    Stewart, James E.; Bodhaine, George Lawrence

    1961-01-01

    According to Indian tradition, floods of unusually great magnitude harassed the Skagit River basin about 1815 and 1856. The heights of these floods were not recorded at the time; so they are called historical floods. Since the arrival of white men about 1863, a number of large and damaging floods have been witnessed and recorded. Data concerning and verifying the early floods, including those of 1815 and 1856, were collected prior to 1923 by James E. Stewart. He talked with many of the early settlers in the valley who had listened to Indians tell about the terrible floods. Some of these settlers had referenced the maximum stages of floods they had witnessed by cutting notches at or measuring to high-water marks on trees. In order to verify flood stages Stewart spent many weeks finding and levelling to high-water marks such as drift deposits, sand layers in coves, and silt in the bark of certain types of trees. Gaging stations have been in operation at various locations on the Skagit River and its tributaries since 1909, so recorded peak stages are available at certain sites for floods occurring since that date. All peak discharge data available for both historical and recorded floods have been listed in this report. The types of floods as to winter and summer, the duration of peaks, and the effect of reservoirs are discussed. In 1899 Sterling Dam was constructed at the head of Gages Slough near Sedro Woolley. This was the beginning of major diking in the lower reaches of the Skagit River. Maps included in the report show the location of most of the dike failures that have occurred during the last 73 years and the area probably inundated by major floods. The damage resulting from certain floods is briefly discussed. The report is concluded with a brief discussion of the U.S. Geological Survey method of computing flood-frequency curves as applied to the Skagit River basin. The treatment of single-station records and a means of combining these records for expressing

  15. Probability plotting position formulas for flood records with historical information

    USGS Publications Warehouse

    Hirsch, R.M.

    1987-01-01

    For purposes of evaluating fitted flood frequency distributions or for purposes of estimating distributions directly from plots of flood peaks versus exceedance probabilities (either by subjective or objective techniques), one needs a probability plotting position formula which can be applied to all of the flood data available: both systematic and historic floods. Some of the formulas in use are simply extensions of existing formulas (such as Hazen and Weibull) used on systematic flood records. New plotting position formulas proposed by Hirsch and Stedinger (1986) and in this paper are based on a recognition that the flood data arises from partially censored sampling of the flood record. The theoretical appropriateness, bias in probability and bias in discharge of the various plotting position formulas are considered. The methods are compared in terms of their effects on flood frequency estimation when an objective curve-fitting method of estimation is employed. Consideration is also given to the correct interpretation of the historical record length and the effect of incorrectly assuming that record length equals the time since the first known historical flood. This assumption is employed in many flood frequency studies and may result in a substantial bias in estimated design flood magnitudes. ?? 1987.

  16. [Nipple discharge].

    PubMed

    Deodato, G; Consoli, A; Riggi, M; Longo, G; Finocchiaro, G B

    1981-02-01

    The Authors examine the various types of breast discharge concentrating in particular on the secretions due to inherent pathology. After having studied origin, they concentrate on the diagnostic significance and the limits of exfoliative cytology and contrast mammography. The Authors conclude by presenting an original protocol of treatment of the afflicted breast illustrating in addition, the various surgical techniques proposed for the cure of the sicknesses of intramammary origin that cause abnormal discharge. PMID:7261200

  17. Flood magnitude and frequency of Black Creek at the culvert on New Jersey Route 94, Vernon Township, Sussex County, New Jersey

    USGS Publications Warehouse

    Barringer, T.H.

    1996-01-01

    The magnitude and frequency of floods at Black Creek tributary at the culvert on New Jersey Route 94 at milepost 43.0 in Vernon Township, New Jersey, were determined by using the New Jersey Department of Environmental Protection Special Report 38 method. Estimates of flood magnitude and frequency calculated by the Special Report 38 method, as well as drainage-basin characteristics, are included in this report. The 100-year-flood estimate is 261 cubic feet per second.

  18. Flood magnitude and frequency of Little Timber Creek at the culvert on Interstate Route 295, Haddon Heights Township, Camden County, New Jersey

    USGS Publications Warehouse

    Barringer, T.H.

    1996-01-01

    The magnitude and frequency of floods at the Little Timber Creek at the culvert on Interstate 295, at milepost 28.9, in Haddon Heights Township, New Jersey, were determined by using the New Jersey Department of Environmental Protection Special Report 38 method. Flood-magnitude and -frequency estimates, as well as drainage-basin characteristics, are included in this report. The 100-year-flood estimate is 770 cubic feet per second.

  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. Integrated assessment of fluvial and pluvial flood hazards in the city of Salzburg, Austria

    NASA Astrophysics Data System (ADS)

    Breinl, Korbinian

    2014-05-01

    Urban flooding can have various sources including floods from a river ('fluvial flooding'), from heavy rainfall usually from convective storms ('pluvial flooding') or from high tides ('storm surge'). Although awareness of pluvial flooding in the scientific community and among policymakers has been increasing, the term 'flooding' is still often seen as a phenomenon explicitly related to a river. Previous research primarily focused on fluvial flooding, with only very recent literature dealing with pluvial flooding. As a result, there are established methods to assess the hazards from fluvial floods, and a smaller number focusing on pluvial floods. Much less work has been conducted on integrated flood hazard assessment taking into account various types of flood hazards. In this work, an integrative, probabilistic modelling framework was developed to assess the urban flood hazard from fluvial and pluvial flooding in the city of Salzburg (Austria). The framework consists of a stochastic multi-site weather generator, which provides input for the hydrological model HBV. In the city of Salzburg, a kNN algorithm converts the simulated mean discharge into peak discharge as well as daily into sub-daily precipitation. The time series generated in this way make the identification of fluvial events (peak discharge) and pluvial events (sub-daily precipitation) possible. The kNN algorithm inherently considers weather situations to ensure a reasonable disaggregation of daily precipitation. Critical thresholds of pluvial flood events are empirically derived from damage data provided by a local insurer as well as action plans from the local fire service. The modelling framework is then applied to examine the probability of the two single flood hazards, as well as the probability of simultaneous pluvial-fluvial flood events.

  1. Flood risk under future climate in West Africa: linking extreme value models and flood generating processes

    NASA Astrophysics Data System (ADS)

    Tramblay, Yves; Amoussou, Ernest; Dorigo, Wouter; Mahé, Gil

    2014-05-01

    For many areas in the world, there is a need for future projections of flood risk in order to improve the possible mitigation actions. However, such an exercise is often made difficult in data-sparse regions, where the limited access to hydrometric data does not allow calibrating hydrological models in a robust way under non-stationary conditions. In this study we present an approach to estimate the possible changes in flood risks, which incorporates flood generating processes into statistical models for extreme values. This approach is illustrated for a West African catchment, the Mono River (12900km²), with discharge, precipitation and temperature data are available between 1988 and 2010 in a few stations and where the dominant flood generating process is soil saturation. A soil moisture accounting model, calibrated against a merged surface soil moisture microwave satellite dataset, is used to estimate the annual maximum soil saturation level that is then related to the location parameter of a Generalized Extreme Value model of annual maximum discharge. With such a model, it is possible to estimate the changes in flood quantiles from the changes in the annual maximum soil saturation level. An ensemble of regional climate models from the ENSEMBLES-AMMA project are then considered to estimate the potential future changes in soil saturation and subsequently the changes in flood risks for the period 2028-2050. A sensitivity analysis of the non-stationary flood quantiles has shown that with the projected changes on precipitation (-2%) and temperature (+1.22°) under the scenario A1B, the projected flood quantiles would stay in the range of the observed variability during 1988-2010. The proposed approach, relying on low data requirements and few assumptions, could be useful to estimate the projected changes in flood risks for other data-sparse catchments.

  2. 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

  3. 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.

  4. Flood profiles for Peace River, south-central Florida

    USGS Publications Warehouse

    Murphy, W.R., Jr.; Hammett, K.M.; Reeter, C.V.

    1978-01-01

    This report presents flood heights and profiles for a 70-mile reach of Peace River from Bartow to Arcadia, Fla. The flood heights were calculated using the U.S. Geological Survey step-backwater model. Profiles were prepared for floods having expected recurrence intervals of 2, 2.33, 5, 10, 25, 50, 100, 200, and 500 years. Flood-peak discharges used in the step-backwater analyses were determined by weighting stream gaging-station data with data from a regional analysis. Land-surface elevation data for 183 cross sections - including values of Manning 's roughness coefficient - also were used in the backwater analysis. Flood height data are generally accurate to + or - 0.5 foot. They indicate that most roads and two bridges in the study reach will be inundated by some of the floods evaluated. (Woodard-USGS)

  5. Connections between winter snowpack and subsequent spring floods in Norway

    NASA Astrophysics Data System (ADS)

    Schlichting, Lena; Engeland, Kolbjørn; Holmqvist, Erik; Bache Stranden, Heidi

    2016-04-01

    In Norway many inland and mountainous catchments have a hydrological regime where snow accumulates during winter. The runoff is delayed until the snow melts during spring. These processes are important for flood forecasting and water resource management, such as operation of hydropower reservoirs. It is commonly assumed that spring flood volume and peak linked to antecedent conditions such as winter snowpack, i.e. a large winter snowpack results in a high spring flood. The aims of this study are (i) to identify for which catchments a high correlation between snow water equivalent (SWE) at the end of the snow accumulation season and the subsequent spring flood, and (ii) establish regression models for these catchments to be used for seasonal flood forecasting. Daily runoff data from 43 distributed catchments all over Norway, each with at least 50 years of observations and a flood regime which is significantly influenced by snowmelt, were used. For each of these catchments we extracted SWE, precipitation and temperature on daily resolution from the on gridded data of Senorge.no. A peak-over-threshold approach was used to select independent flood events above the 90-th percentile. Maximum discharge, duration and volume were calculated for each event. The contribution of rain and snowmelt to each flood was additionally determined, based on snowmelt, precipitation and temperature data. The spring flood was defined as the first flood event that occurs after the date of maximum SWE, and the snowmelt contribution of at least 70%. The contribution of rain to a spring flood is independent of maximum SWE, resulting in a weaker correlation between maximum SWE and spring flood size. We therefore scaled the flood with the percentage of snow contribution to the flood event in order to adjust for the contribution from rain. The correlations between SWE and the spring flood were higher for scaled spring floods than for the unscaled ones. The results show for half of the stations a

  6. Discharge indices for water quality loads

    USGS Publications Warehouse

    Vogel, R.M.; Stedinger, J.R.; Hooper, R.P.

    2003-01-01

    Effective discharge has been used to describe the streamflow level that is responsible for transporting the most sediment over the long term. Careful inspection reveals that this concept may not have been well defined, and different interpretations have led to conflicting representations. Because total load is ultimately the quantity of interest, we define a new index, the half-load discharge, which is that discharge above and below which half the total long-term load is transported. The value of the half-load discharge is derived for a reasonable model of flows and constituent concentration. The effective discharge has generally been thought to be a relatively common or frequent flood. The half-load discharge is generally a much greater and less frequent flow than commonly used estimators of the effective discharge. Relations provided here for the frequency and magnitude of the half-load discharge provide evidence that it is relatively rare floods that transport most of the sediment over the long term. These ideas apply to other constituents as well.

  7. Historical changes in frequency and seasonality of extreme floods in Prague

    NASA Astrophysics Data System (ADS)

    Elleder, L.

    2015-02-01

    This study presents a flood frequency analysis for the Vltava River catchment using a major profile in Prague. The estimates of peak discharges for the pre-instrumental period of 1118-1824 based on documentary sources were carried out using different approaches. 187 flood peak discharges derived for the pre-instrumental period augmented 150 records for the instrumental period of 1825-2013. Flood selection was based on Q10 criteria. Six flood-rich periods in total were identified for 1118-2013. Results of this study correspond with similar studies published earlier for some Central European catchments, except for the period around 1750. Presented results indicate that the territory of the present Czech Republic might have experienced in the past, extreme floods comparable, with regard to peak discharge (POTQ10) and frequency, to the flood events recorded recently.

  8. Influence of Sediment Transport on Formation of Sandbars in Drainage Canals during Floods

    NASA Astrophysics Data System (ADS)

    Mukai, Akie; Taruya, Hiroyuki; Tanaka, Yoshikazu; Naka, Tatsuo

    Sediment of drainage canals plays significant roles for aquatic plant rooting, fish spawning and invertebrate habitats. In steep areas, it is difficult to maintain the sediment during floods because water flows rapidly. Fast flowing water causes sediment loss and habitat loss through intense sediment transport. Therefore, we installed spur dikes in field drainage canals to control sediment transport and form sandbars to provide habitats for aquatic organisms. The results showed that sandbars were formed by controlling the sediment transport and the process of sandbar formation depended on the magnitude of flood discharge. When the flood discharge was small, the sediment was washed out between the spur dikes, and distinct sandbars were not formed except in areas aquatic plants. When the flood discharge was large, the sediment accumulated between the spur dikes, and sandbars were clearly formed. Without spur dikes, most sediment was flushed away by flood discharges. Consequently, spur dikes facilitate an increase in invertebrate populations by establishing sandbars for habitats.

  9. Flood frequency: expected and unexpected probabilities

    USGS Publications Warehouse

    Thomas, D.M.

    1976-01-01

    Flood-frequency curves may be defined either with or without an ' expeced probability ' adustment; and the two curves differ in the way that they attempt to average the time-sampling uncertainties. A curve with no adustment is shown to estimate a median value of both discharge and frequency of occurrence, while an expected probability curve is shown to estimate a mean frequency of flood years. The attributes and constraints of the two types of curves for various uses are discussed. 

  10. 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

  11. Assessment of channel changes, model of historical floods, and effects of backwater on flood stage, and flood mitigation alternatives for the Wichita River at Wichita Falls, Texas

    USGS Publications Warehouse

    Winters, Karl E.; Baldys, Stanley

    2011-01-01

    In cooperation with the City of Wichita Falls, the U.S. Geological Survey assessed channel changes on the Wichita River at Wichita Falls, Texas, and modeled historical floods to investigate possible causes and potential mitigation alternatives to higher flood stages in recent (2007 and 2008) floods. Extreme flooding occurred on the Wichita River on June 30, 2007, inundating 167 homes in Wichita Falls. Although a record flood stage was reached in June 2007, the peak discharge was much less than some historical floods at Wichita Falls. Streamflow and stage data from two gages on the Wichita River and one on Holliday Creek were used to assess the interaction of the two streams. Changes in the Wichita River channel were evaluated using historical aerial and ground photography, comparison of recent and historical cross sections, and comparison of channel roughness coefficients with those from earlier studies. The floods of 2007 and 2008 were modeled using a one-dimensional step-backwater model. Calibrated channel roughness was larger for the 2007 flood compared to the 2008 flood, and the 2007 flood peaked about 4 feet higher than the 2008 flood. Calibration of the 1941 flood yielded a channel roughness coefficient (Manning's n) of 0.030, which represents a fairly clean natural channel. The step-backwater model was also used to evaluate the following potential mitigation alternatives: (1) increasing the capacity of the bypass channel near River Road in Wichita Falls, Texas; (2) removal of obstructions near the Scott Avenue and Martin Luther King Junior Boulevard bridges in Wichita Falls, Texas; (3) widening of aggraded channel banks in the reach between Martin Luther King Junior Boulevard and River Road; and (4) reducing channel bank and overbank roughness. Reductions in water-surface elevations ranged from 0.1 foot to as much as 3.0 feet for the different mitigation alternatives. The effects of implementing a combination of different flood-mitigation alternatives were

  12. Floods of September 6, 1960, in eastern Puerto Rico

    USGS Publications Warehouse

    Barnes, Harry Hawthorne; Bogart, Dean Butler

    1961-01-01

    The floods of September 6, 1960, were the greatest known on many streams in eastern Puerto Rico. There were 117 lives lost, 30 persons missing, and 136 injured. Total damage was estimated in excess of $7 million. Several thousand persons were forced from their homes by the floods as 484, houses were destroyed and more than 3,600 others were. damaged. All main highways and most secondary roads were impassable for a short period during the floods and damage to them was heavy. Following the passage of Hurricane Donna off the northeast coast, rains of very high intensity fell over parts of the eastern half of the island, beginning about 9 p.m. September 5. By dawn September 6, rains totaling more than 10 inches over a large area produced floods in every river basin from the Rio Grande de Manati eastward. Flood discharges on the Rio Humacao, Rio Turabo, and Rio Valenciano were the greatest known and rank high among the notable floods on streams that drain from 6 to ]5 square miles. An outstanding feature of the floods was the unusually high magnitude of peak discharges--9 of the 24 peak discharges determined had Myers ratings greater than 80 percent.

  13. Effects of 100 years wastewater irrigation on resistance genes, class 1 integrons and IncP-1 plasmids in Mexican soil

    PubMed Central

    Jechalke, Sven; Broszat, Melanie; Lang, Friederike; Siebe, Christina; Smalla, Kornelia; Grohmann, Elisabeth

    2015-01-01

    Long-term irrigation with untreated wastewater can lead to an accumulation of antibiotic substances and antibiotic resistance genes in soil. However, little is known so far about effects of wastewater, applied for decades, on the abundance of IncP-1 plasmids and class 1 integrons which may contribute to the accumulation and spread of resistance genes in the environment, and their correlation with heavy metal concentrations. Therefore, a chronosequence of soils that were irrigated with wastewater from 0 to 100 years was sampled in the Mezquital Valley in Mexico in the dry season. The total community DNA was extracted and the absolute and relative abundance (relative to 16S rRNA genes) of antibiotic resistance genes (tet(W), tet(Q), aadA), class 1 integrons (intI1), quaternary ammonium compound resistance genes (qacE+qacEΔ1) and IncP-1 plasmids (korB) were quantified by real-time PCR. Except for intI1 and qacE+qacEΔ1 the abundances of selected genes were below the detection limit in non-irrigated soil. Confirming the results of a previous study, the absolute abundance of 16S rRNA genes in the samples increased significantly over time (linear regression model, p < 0.05) suggesting an increase in bacterial biomass due to repeated irrigation with wastewater. Correspondingly, all tested antibiotic resistance genes as well as intI1 and korB significantly increased in abundance over the period of 100 years of irrigation. In parallel, concentrations of the heavy metals Zn, Cu, Pb, Ni, and Cr significantly increased. However, no significant positive correlations were observed between the relative abundance of selected genes and years of irrigation, indicating no enrichment in the soil bacterial community due to repeated wastewater irrigation or due to a potential co-selection by increasing concentrations of heavy metals. PMID:25784901

  14. Reconstruction of soil moisture for the past 100 years in eastern Siberia by using δ13C of larch tree rings

    NASA Astrophysics Data System (ADS)

    Tei, Shunsuke; Sugimoto, Atsuko; Yonenobu, Hitoshi; Yamazaki, Takeshi; Maximov, Trofim C.

    2013-07-01

    stable carbon isotope ratio (δ13C) chronology for the past 100 years was developed from larch tree rings in eastern Siberia (near Yakutsk, 62°14'N, 129°37'E), to reconstruct past soil moisture water equivalent (SWE). Based on the correlation analyses between SWE and tree ring δ13C, we developed a linear regression model for SWE in the late growing period (LGP: 15 July to 31 August) using annual tree ring δ13C, which was calculated from the combination of latewood in a current year and earlywood in the following year, and then reconstructed SWE (LGP) for 1908-2007. Reconstructed SWE was compared with factors such as the output of the land surface model, annual precipitation, and Palmer Drought Severity Index for July. From the results, the reconstructed SWE appears reasonable and shows a large variation, including repeated occurrences of severe drought and an unprecedented high soil moisture event in 2006-2007 during the past 100 years. The reconstruction also captured a past documented record of severe drought in the 1940s. Despite the generally good performance of the reconstruction, by the 1930s the estimated SWE was higher than that expected from the annual precipitation. Tree ring width and δ13C were negatively correlated in most periods. However, the negative correlation was weaker for the period from 1919 to 1925, when relatively low air temperature was observed. This result suggests that the rate of photosynthesis, together with the degree of stomata opening, also affected the tree ring δ13C during cool periods.

  15. Necessity of Flood Early Warning Systems in India

    NASA Astrophysics Data System (ADS)

    Kurian, C.; Natesan, U.; Durga Rao, K. H. V.

    2014-12-01

    India is one of the highly flood prone countries in the world. National flood commission has reported that 400,000 km² of geographical area is prone to floods, constituting to twelve percent of the country's geographical area. Despite the reoccurrences of floods, India still does not have a proper flood warning system. Probably this can be attributed to the lack of trained personnel in using advanced techniques. Frequent flood hazards results in damage to livelihood, infrastructure and public utilities. India has a potential to develop an early warning system since it is one of the few countries where satellite based inputs are regularly used for m