WorldWideScience

Sample records for flood retention basins

  1. Planning of technical flood retention measures in large river basins under consideration of imprecise probabilities of multivariate hydrological loads

    Directory of Open Access Journals (Sweden)

    D. Nijssen

    2009-08-01

    Full Text Available As a result of the severe floods in Europe at the turn of the millennium, the ongoing shift from safety oriented flood control towards flood risk management was accelerated. With regard to technical flood control measures it became evident that the effectiveness of flood control measures depends on many different factors, which cannot be considered with single events used as design floods for planning. The multivariate characteristics of the hydrological loads have to be considered to evaluate complex flood control measures. The effectiveness of spatially distributed flood control systems differs for varying flood events. Event-based characteristics such as the spatial distribution of precipitation, the shape and volume of the resulting flood waves or the interactions of flood waves with the technical elements, e.g. reservoirs and flood polders, result in varying efficiency of these systems. Considering these aspects a flood control system should be evaluated with a broad range of hydrological loads to get a realistic assessment of its performance under different conditions. The consideration of this variety in flood control planning design was one particular aim of this study. Hydrological loads were described by multiple criteria. A statistical characterization of these criteria is difficult, since the data base is often not sufficient to analyze the variety of possible events. Hydrological simulations were used to solve this problem. Here a deterministic-stochastic flood generator was developed and applied to produce a large quantity of flood events which can be used as scenarios of possible hydrological loads. However, these simulations imply many uncertainties. The results will be biased by the basic assumptions of the modeling tools. In flood control planning probabilities are applied to characterize uncertainties. The probabilities of the simulated flood scenarios differ from probabilities which would be derived from long time series

  2. Natural flood retention in mountain areas by forests and forest like short rotation coppices

    Science.gov (United States)

    Reinhardt-Imjela, Christian; Schulte, Achim; Hartwich, Jens

    2017-04-01

    Natural water retention is an important element of flood risk management in flood generating headwater areas in the low mountain ranges of Central Europe. In this context forests are of particular interest because of the high infiltration capacities of the soils and to increase water retention reforestation of agricultural land would be worthwhile. However competing claims for land use in intensely cultivated regions in Central Europe impede reforestation plans so the potential for a significant increase of natural water retention in forests is strongly limited. Nevertheless the development of innovative forms of land use and crop types opens new perspectives for a combination of agricultural land use with the water retention potential of forests. Recently the increasing demand for renewable energy resources leads to the cultivation of fast growing poplar and willow hybrids on agricultural land in short rotation coppices (SRC). Harvested in cycles of three to six years the wood from the plantations can be used as wood chips for heat and electricity production in specialized power plants. With short rotation plantations a crop type is established on arable land which is similar to forests so that an improvement of water retention can be expected. To what extend SRC may contribute to flood attenuation in headwater areas is investigated for the Chemnitzbach watershed (48 km2) in the Eastern Ore Mountains (Free State of Saxony, Germany), a low mountain range which is an important source of flood runoff in the Elbe basin. The study is based on a rainfall-runoff model of flood events using the conceptual modelling system NASIM. First results reveal a significant reduction of the flood peaks after the implementation of short rotation coppices. However the effect strongly depends on two factors. The first factor is the availability of areas for the plantations. For a substantial impact on the watershed scale large areas are required and with decreasing percentages of SRC

  3. Flood tracking chart, Amite River Basin, Louisiana

    Science.gov (United States)

    Callender, Lawrence E.; McCallum, Brian E.; Brazelton, Sebastian R.; Anderson, Mary L.; Ensminger, Paul A.

    1998-01-01

    The Amite River Basin flood tracking chart is designed to assist emergency response officials and the local public in making informed decisions about the safety of life and property during floods along the Amite and Comite Rivers and Bayou Manchac in southeastern Louisiana. This chart is similar in concept to the charts used to track hurricanes; the user can record the latest river stage information at selected gaging stations and the latest flood crest predictions. The latest stage data can be compared to historical flood peaks as well as to the slab or pier elevation of a threatened property. The chart also discusses how to acquire the latest river stage data from the Internet and a recorded voice message.

  4. FLOOD SUSCEPTIBILITY ASSESSMENT IN THE NIRAJ BASIN

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    SANDA ROŞCA

    2012-03-01

    Full Text Available Flood susceptibility assessment in the Niraj basin. In the context of global warming and the increasing frequency of extreme weather events, it becomes evident that we have to face natural hazards, such as floods. In the area of Niraj basin this phenomenon is specific both in the spring, because of the snow melting and of the precipitations which come along with the season, and then in the summer because of the torrential precipitations but rarely in autumn and winter. The aim of this paper is to determinate the susceptibility of the zone and obtain a map which will take into consideration the possibility of a flooding. Defining vulnerability can help us understand this type of natural disasters and find the best ways to reduce it. For this purpose we use thematic layers, morphological characteristics (slope and depth fragmentation, hydrological characteristics, geology, pedology (permeability and soil texture, landuse, precipitation data, and human interventions because in this way we have the possibility to use data mining for this purpose. Data mining will allow us to extract new information based on the existing sets of data.The final result will be a thematic map that highlights the areas which are exposed to the flood. Therefore, this map can be used as a support decision for local government or business purposes.

  5. Poster exhibition: hydraulic simulation and flood protection in the river basins of Kocher and Jagst, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Giesecke, J.; Marx, W.; Kerle, F.; Gittinger, H. [Stuttgart Univ. (Germany). Inst. for Hydraulic Engineering

    2001-07-01

    Because of the geological and meteorological situation, flood events in the Kocher and Jagst valleys mean large inundated areas. Since the 50ies many technical measures for flood protection have been realized in the Kocher-Jagst-basin with a financial volume until 1996 of approximately 390 million Euro. The retention basins entailed marked improvements of the flood protection down to the central parts of Kocher and Jagst. The natural flood retention of the riverplains is secured by valid classification by the administration. Dams, levees and water development measures like river regulations were limited to locations within riparian communities which they efficiently protect against damages by smaller or medium floods. The Institute of Hydraulic Engineering of the University of Stuttgart in co-operation with a Stuttgart engineer's office was commissioned to work out unsteady hydraulic models for river Kocher (1998) and river Jagst (1999). On the basis of these models regional and cumulative supraregional effects of additionally required flood protection measures should be examined. (orig.)

  6. Assessment of retention basin volume and outlet capacity in urban ...

    Indian Academy of Sciences (India)

    - trol of pollution moved by rainfall runoff is achieved by installing outlets and small retention basins in stormwater collection systems, thereby allowing only a certain amount of rainfall water to overflow and leading the remaining to treatment ...

  7. Floods in the Skunk River basin, Iowa

    Science.gov (United States)

    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.

  8. Removal of Heavy Metals and PAH in Retention Basins

    DEFF Research Database (Denmark)

    Larsen, Torben; Neerup-Jensen, Ole

    2004-01-01

    Solid seperation in retention basins is strongly non-linear and depends significantly on the flow rate and the settling characteristics of the particles. Accordingly the calculation of the annual loads of pollutants from storm overflows including basins is rather complex and time consuming. The p...

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

    International Nuclear Information System (INIS)

    Head, J.W.

    1982-01-01

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

  10. Flood forecasting and early warning system for Dungun River Basin

    International Nuclear Information System (INIS)

    Hafiz, I; Sidek, L M; Basri, H; Fukami, K; Hanapi, M N; Livia, L; Nor, M D

    2013-01-01

    Floods can bring such disasters to the affected dweller due to loss of properties, crops and even deaths. The damages to properties and crops by the severe flooding are occurred due to the increase in the economic value of the properties as well as the extent of the flood. Flood forecasting and warning system is one of the examples of the non-structural measures which can give early warning to the affected people. People who live near the flood-prone areas will be warned so that they can evacuate themselves and their belongings before the arrival of the flood. This can considerably reduce flood loss and damage and above all, the loss of human lives. Integrated Flood Analysis System (IFAS) model is a runoff analysis model converting rainfall into runoff for a given river basin. The simulation can be done using either ground or satellite-based rainfall to produce calculated discharge within the river. The calculated discharge is used to generate the flood inundation map within the catchment area for the selected flood event using Infowork RS.

  11. Assessment of retention basin volume and outlet capacity in urban ...

    Indian Academy of Sciences (India)

    The quality of river water or other surface waters is detrimentally affected by the contaminants carried by the rainfall runoff in urban areas. The control of pollution moved by rainfall runoff is achieved by installing outlets and small retention basins in stormwater collection systems, thereby allowing only a certain amount of ...

  12. Assessment of retention basin volume and outlet capacity in urban ...

    Indian Academy of Sciences (India)

    Mehmet A Yurdusev et al. The level of contaminants transported from the cities to such water bodies is monitored by installing small retention basins in stormwater drain systems connected to the outlets. The idea here is to allow some amount of rain water to overflow from the outlets and the rest to be led either to treatment ...

  13. Identification of Flood Source Areas in Pahang River Basin, Peninsular Malaysia

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    Wan Nor Azmin Sulaiman

    2010-01-01

    Full Text Available The roles of upland watersheds in flood source contribution towards downstream areas in a river basin system are generally neglected in the inclusion of management strategy related to downstream flood management. In this study an assessment on the flood source area of Pahang river basin was attempted. The concept of unit flood response as an index of hydrologic response was used in identifying the flood source areas for the basin. The results indicated that among the 16 sub-basins of Pahang river basin, sub-basin of Sungai Pahang is ranked first in production of flood discharge while Sungai Perting sub-basin is ranked last in term of production of flood discharge. Comparison between maximum daily discharge of upper and lower segments of Pahang river basin indicated that up-stream watershed contributes significantly high and more flood (94.78% than down-stream (5.22%. In addition, the upland watersheds were found to more efficient in producing surface runoff and send the floodwater to the lower receiving basin of Sungai Pahang. Considering that basin flood response is generally a nonlinear function of many factors, the sub-basins that are located nearest to and most distance from the basin outlet do not necessarily generate the highest and lowest contribution to the flood peak at the outlet. Similarly, sub-basins producing the highest or lowest absolute or specific discharge at their own outlet may not necessarily ranked first and last in flood index.

  14. Flood Risk Index Assessment in Johor River Basin

    International Nuclear Information System (INIS)

    Ahmad Shakir Mohd Saudi; Hafizan Juahir; Azman Azid; Fazureen Azaman; Ahmad Shakir Mohd Saudi

    2015-01-01

    This study is focusing on constructing the flood risk index in the Johor river basin. The application of statistical methods such as factor analysis (FA), statistical process control (SPC) and artificial neural network (ANN) had revealed the most efficient flood risk index. The result in FA was water level has correlation coefficient of 0.738 and the most practicable variable to be used for the warning alert system. The upper control limits (UCL) for the water level in the river basin Johor is 4.423 m and the risk index for the water level has been set by this method consisting of 0-100.The accuracy of prediction has been evaluated by using ANN and the accuracy of the test result was R 2 = 0.96408 with RMSE= 2.5736. The future prediction for UCL in Johor river basin has been predicted and the value was 3.75 m. This model can shows the current and future prediction for flood risk index in the Johor river basin and can help local authorities for flood control and prevention of the state of Johor. (author)

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

    Science.gov (United States)

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

    2017-12-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  17. 2 Dimensional Hydrodynamic Flood Routing Analysis on Flood Forecasting Modelling for Kelantan River Basin

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    Azad Wan Hazdy

    2017-01-01

    Full Text Available Flood disaster occurs quite frequently in Malaysia and has been categorized as the most threatening natural disaster compared to landslides, hurricanes, tsunami, haze and others. A study by Department of Irrigation and Drainage (DID show that 9% of land areas in Malaysia are prone to flood which may affect approximately 4.9 million of the population. 2 Dimensional floods routing modelling demonstrate is turning out to be broadly utilized for flood plain display and is an extremely viable device for evaluating flood. Flood propagations can be better understood by simulating the flow and water level by using hydrodynamic modelling. The hydrodynamic flood routing can be recognized by the spatial complexity of the schematization such as 1D model and 2D model. It was found that most of available hydrological models for flood forecasting are more focus on short duration as compared to long duration hydrological model using the Probabilistic Distribution Moisture Model (PDM. The aim of this paper is to discuss preliminary findings on development of flood forecasting model using Probabilistic Distribution Moisture Model (PDM for Kelantan river basin. Among the findings discuss in this paper includes preliminary calibrated PDM model, which performed reasonably for the Dec 2014, but underestimated the peak flows. Apart from that, this paper also discusses findings on Soil Moisture Deficit (SMD and flood plain analysis. Flood forecasting is the complex process that begins with an understanding of the geographical makeup of the catchment and knowledge of the preferential regions of heavy rainfall and flood behaviour for the area of responsibility. Therefore, to decreases the uncertainty in the model output, so it is important to increase the complexity of the model.

  18. Improving Flood Predictions in Data-Scarce Basins

    Science.gov (United States)

    Vimal, Solomon; Zanardo, Stefano; Rafique, Farhat; Hilberts, Arno

    2017-04-01

    Flood modeling methodology at Risk Management Solutions Ltd. has evolved over several years with the development of continental scale flood risk models spanning most of Europe, the United States and Japan. Pluvial (rain fed) and fluvial (river fed) flood maps represent the basis for the assessment of regional flood risk. These maps are derived by solving the 1D energy balance equation for river routing and 2D shallow water equation (SWE) for overland flow. The models are run with high performance computing and GPU based solvers as the time taken for simulation is large in such continental scale modeling. These results are validated with data from authorities and business partners, and have been used in the insurance industry for many years. While this methodology has been proven extremely effective in regions where the quality and availability of data are high, its application is very challenging in other regions where data are scarce. This is generally the case for low and middle income countries, where simpler approaches are needed for flood risk modeling and assessment. In this study we explore new methods to make use of modeling results obtained in data-rich contexts to improve predictive ability in data-scarce contexts. As an example, based on our modeled flood maps in data-rich countries, we identify statistical relationships between flood characteristics and topographic and climatic indicators, and test their generalization across physical domains. Moreover, we apply the Height Above Nearest Drainage (HAND)approach to estimate "probable" saturated areas for different return period flood events as functions of basin characteristics. This work falls into the well-established research field of Predictions in Ungauged Basins.

  19. Flood Risk in the Danube basin under climate change

    Science.gov (United States)

    Schröter, Kai; Wortmann, Michel; del Rocio Rivas Lopez, Maria; Liersch, Stefan; Viet Nguyen, Dung; Hardwick, Stephen; Hattermann, Fred

    2017-04-01

    The projected increase in temperature is expected to intensify the hydrological cycle, and thus more intense precipitation is likely to increase hydro-meteorological extremes and flood hazard. However to assess the future dynamics of hazard and impact induced by these changes it is necessary to consider extreme events and to take a spatially differentiated perspective. The Future Danube Model is a multi-hazard and risk model suite for the Danube region which has been developed in the OASIS project. The model comprises modules for estimating potential perils from heavy precipitation, heat-waves, floods, droughts, and damage risk considering hydro-climatic extremes under current and climate change conditions. Web-based open Geographic Information Systems (GIS) technology allows customers to graphically analyze and overlay perils and other spatial information such as population density or assets exposed. The Future Danube Model combines modules for weather generation, hydrological and hydrodynamic processes, and supports risk assessment and adaptation planning support. This contribution analyses changes in flood hazard in the Danube basin and in flood risk for the German part of the Danube basin. As climate change input, different regionalized climate ensemble runs of the newest IPCC generation are used, the so-called Representative Concentration Pathways (RCPs). They are delivered by the CORDEX initiative (Coordinated Downscaling Experiments). The CORDEX data sample is extended using the statistical weather generator (IMAGE) in order to also consider extreme events. Two time slices are considered: near future 2020-2049 and far future 2050-2079. This data provides the input for the hydrological, hydraulic and flood loss model chain. Results for RCP4.5 and RCP8.5 indicate an increase in intensity and frequency of peak discharges and thus in flood hazard for many parts of the Danube basin.

  20. Flow ensemble prediction for flash flood warnings at ungauged basins

    Science.gov (United States)

    Demargne, Julie; Javelle, Pierre; Organde, Didier; Caseri, Angelica; Ramos, Maria-Helena; de Saint Aubin, Céline; Jurdy, Nicolas

    2015-04-01

    Flash floods, which are typically triggered by severe rainfall events, are difficult to monitor and predict at the spatial and temporal scales of interest due to large meteorological and hydrologic uncertainties. In particular, uncertainties in quantitative precipitation forecasts (QPF) and quantitative precipitation estimates (QPE) need to be taken into account to provide skillful flash flood warnings with increased warning lead time. In France, the AIGA discharge-threshold flood warning system is currently being enhanced to ingest high-resolution ensemble QPFs from convection-permitting numerical weather prediction (NWP) models, as well as probabilistic QPEs, to improve flash flood warnings for small-to-medium (from 10 to 1000 km²) ungauged basins. The current deterministic AIGA system is operational in the South of France since 2005. It ingests the operational radar-gauge QPE grids from Météo-France to run a simplified hourly distributed hydrologic model at a 1-km² resolution every 15 minutes (Javelle et al. 2014). This produces real-time peak discharge estimates along the river network, which are subsequently compared to regionalized flood frequency estimates of given return periods. Warnings are then provided to the French national hydro-meteorological and flood forecasting centre (SCHAPI) and regional flood forecasting offices, based on the estimated severity of ongoing events. The calibration and regionalization of the hydrologic model has been recently enhanced to implement an operational flash flood warning system for the entire French territory. To quantify the QPF uncertainty, the COSMO-DE-EPS rainfall ensembles from the Deutscher Wetterdienst (20 members at a 2.8-km resolution for a lead time of 21 hours), which are available on the North-eastern part of France, were ingested in the hydrologic model of the AIGA system. Streamflow ensembles were produced and probabilistic flash flood warnings were derived for the Meuse and Moselle river basins and

  1. Indus Basin Floods of 2010: Souring of a Faustian Bargain?

    Directory of Open Access Journals (Sweden)

    Daanish Mustafa

    2011-02-01

    Full Text Available The great flood of 2010 in Pakistan was not an accidental, unpredictable and random episode in the hydrologic development of the Indus basin, but rather a by-product of national decisions on water use, integrally linked, as well, to the design of the social landscape. In immediate and mid terms, acute impacts are expected to be concentrated among households with fragile and sensitive livelihoods. To attenuate an evolving low-level humanitarian, social and political crisis, and to prevent backsliding to Pakistan’s development progress, attention should focus on water drainage and rapid rehabilitation of farmland. Local government structures can be engaged in the distribution and implementation of recovery programs. In Pakistan, the hydrological priorities have always been irrigation and power generation, but in the interest of preventing a costly recurrence, Pakistani flood management and early alert systems require structural revision.

  2. A Fresh Start for Flood Estimation in Ungauged Basins

    Science.gov (United States)

    Woods, R. A.

    2017-12-01

    The two standard methods for flood estimation in ungauged basins, regression-based statistical models and rainfall-runoff models using a design rainfall event, have survived relatively unchanged as the methods of choice for more than 40 years. Their technical implementation has developed greatly, but the models' representation of hydrological processes has not, despite a large volume of hydrological research. I suggest it is time to introduce more hydrology into flood estimation. The reliability of the current methods can be unsatisfactory. For example, despite the UK's relatively straightforward hydrology, regression estimates of the index flood are uncertain by +/- a factor of two (for a 95% confidence interval), an impractically large uncertainty for design. The standard error of rainfall-runoff model estimates is not usually known, but available assessments indicate poorer reliability than statistical methods. There is a practical need for improved reliability in flood estimation. Two promising candidates to supersede the existing methods are (i) continuous simulation by rainfall-runoff modelling and (ii) event-based derived distribution methods. The main challenge with continuous simulation methods in ungauged basins is to specify the model structure and parameter values, when calibration data are not available. This has been an active area of research for more than a decade, and this activity is likely to continue. The major challenges for the derived distribution method in ungauged catchments include not only the correct specification of model structure and parameter values, but also antecedent conditions (e.g. seasonal soil water balance). However, a much smaller community of researchers are active in developing or applying the derived distribution approach, and as a result slower progress is being made. A change in needed: surely we have learned enough about hydrology in the last 40 years that we can make a practical hydrological advance on our methods for

  3. Real time flood forecasting in the Upper Danube basin

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    Nester Thomas

    2016-12-01

    Full Text Available This paper reports on experience with developing the flood forecasting model for the Upper Danube basin and its operational use since 2006. The model system consists of hydrological and hydrodynamic components, and involves precipitation forecasts. The model parameters were estimated based on the dominant processes concept. Runoff data are assimilated in real time to update modelled soil moisture. An analysis of the model performance indicates 88% of the snow cover in the basin to be modelled correctly on more than 80% of the days. Runoff forecasting errors decrease with catchment area and increase with forecast lead time. The forecast ensemble spread is shown to be a meaningful indicator of the forecast uncertainty. During the 2013 flood, there was a tendency for the precipitation forecasts to underestimate event precipitation and for the runoff model to overestimate runoff generation which resulted in, overall, rather accurate runoff forecasts. It is suggested that the human forecaster plays an essential role in interpreting the model results and, if needed, adjusting them before issuing the forecasts to the general public.

  4. LIQUID EFFLUENT RETENTION FACILITY (LERF) BASIN 42 STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN JB

    2004-10-29

    This report documents laboratory results obtained under test plan RPP-21533 for samples submitted by the Effluent Treatment Facility (ETF) from the Liquid Effluent Retention Facility (LERF) Basin 42 (Reference 1). The LERF Basin 42 contains process condensate (PC) from the 242-A Evaporator and landfill leachate. The ETF processes one PC campaign approximately every 12 to 18 months. A typical PC campaign volume can range from 1.5 to 2.5 million gallons. During the September 2003 ETF Basin 42 processing campaign, a recurring problem with 'gelatinous buildup' on the outlet filters from 60A-TK-I (surge tank) was observed (Figure 1). This buildup appeared on the filters after the contents of the surge tank were adjusted to a pH of between 5 and 6 using sulfuric acid. Biological activity in the PC feed was suspected to be the cause of the gelatinous material. Due to this buildup, the filters (10 {micro}m CUNO) required daily change out to maintain process throughput.

  5. Erosion potential from Missoula floods in the Pasco Basin, Washington

    International Nuclear Information System (INIS)

    Craig, R.G.; Hanson, J.P.

    1985-12-01

    Localities within the Pasco Basin preserve evidence of Missoula floods. Deposits are 46% sand-sized, 36% gravel-sized, and 18% finer than sand-sized. Mean thickness is 39 meters. High water marks at Wallula Gap require a discharge of approximately 12.5 Mcms. At Sentinel Gap, the slope-area method shows that the high water marks require a discharge of 34.6 Mcms. Since this discharge greatly exceeds any estimated for Missoula floods, there must have been backwater ponding from Wallula Gap. Projecting the slope of the water surface at the upper end of Wallula Gap to the downstream cross section at Gable Mountain leads to a discharge of 9.5 Mcms at Sentinel Gap. The HEC-6 steady state code and four sediment transport equations were applied. Assuming sand-sized particles, DuBoys function estimated 4 to 9 meters of scour. Yang's equation estimated 3 to 4 meters of scour. These are a minimum. A hydrograph synthesized for the boundaries of the Pasco Basin shows the maxima of the flood would occur after 90 h at Sentinel Gap, and at 114 h at Wallula Gap. The 200 areas will remain inundated for four days and six hours. With a quasi-dynamic sediment transport computation, HEC-6 scour estimates range from 0.61 meters to 0.915 meters. This is a minimum amount and erosion is highly variable suggesting reworking of sediment. The Meyer-Peter Meuller equations show less than 1 meter of net scour in the 200 areas. More extensive erosion was achieved during particular time steps of this analysis suggesting that sediment re-working would occur

  6. Erosion potential from Missoula floods in the Pasco Basin, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Craig, R.G.; Hanson, J.P.

    1985-12-01

    Localities within the Pasco Basin preserve evidence of Missoula floods. Deposits are 46% sand-sized, 36% gravel-sized, and 18% finer than sand-sized. Mean thickness is 39 meters. High water marks at Wallula Gap require a discharge of approximately 12.5 Mcms. At Sentinel Gap, the slope-area method shows that the high water marks require a discharge of 34.6 Mcms. Since this discharge greatly exceeds any estimated for Missoula floods, there must have been backwater ponding from Wallula Gap. Projecting the slope of the water surface at the upper end of Wallula Gap to the downstream cross section at Gable Mountain leads to a discharge of 9.5 Mcms at Sentinel Gap. The HEC-6 steady state code and four sediment transport equations were applied. Assuming sand-sized particles, DuBoys function estimated 4 to 9 meters of scour. Yang's equation estimated 3 to 4 meters of scour. These are a minimum. A hydrograph synthesized for the boundaries of the Pasco Basin shows the maxima of the flood would occur after 90 h at Sentinel Gap, and at 114 h at Wallula Gap. The 200 areas will remain inundated for four days and six hours. With a quasi-dynamic sediment transport computation, HEC-6 scour estimates range from 0.61 meters to 0.915 meters. This is a minimum amount and erosion is highly variable suggesting reworking of sediment. The Meyer-Peter Meuller equations show less than 1 meter of net scour in the 200 areas. More extensive erosion was achieved during particular time steps of this analysis suggesting that sediment re-working would occur.

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

    Science.gov (United States)

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

    2018-02-09

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

  8. Interactions between Land use and Flood Management in the Chi River Basin

    NARCIS (Netherlands)

    Kuntiyawichai, K.

    2012-01-01

    The damages caused by floods remain an issue in the Chi River Basin, Thailand. Therefore, an integrated flood management framework needs to be developed to minimize the negative effects of floods of different magnitude. In response, a hydrological model (SWAT) and a hydraulic (1D/2D SOBEK) model

  9. Extreme multi-basin flooding linked with extra-tropical cyclones

    Science.gov (United States)

    De Luca, Paolo; Hillier, John K.; Wilby, Robert L.; Quinn, Nevil W.; Harrigan, Shaun

    2017-11-01

    Fluvial floods are typically investigated as ‘events’ at the single basin-scale, hence flood management authorities may underestimate the threat of flooding across multiple basins driven by large-scale and nearly concurrent atmospheric event(s). We pilot a national-scale statistical analysis of the spatio-temporal characteristics of extreme multi-basin flooding (MBF) episodes, using peak river flow data for 260 basins in Great Britain (1975‑2014), a sentinel region for storms impacting northwest and central Europe. During the most widespread MBF episode, 108 basins (~46% of the study area) recorded annual maximum (AMAX) discharge within a 16 day window. Such episodes are associated with persistent cyclonic and westerly atmospheric circulations, atmospheric rivers, and precipitation falling onto previously saturated ground, leading to hydrological response times distributed, yet differentially time-lagged, wind and flood damages. These findings have implications for emergency responders, insurers and contingency planners worldwide.

  10. Flood Inundation Modelling in the Kuantan River Basin using 1D-2D Flood Modeller coupled with ASTER-GDEM

    Science.gov (United States)

    Ng, Z. F.; Gisen, J. I.; Akbari, A.

    2018-03-01

    Topography dataset is an important input in performing flood inundation modelling. However, it is always difficult to obtain high resolution topography that provide accurate elevation information. Fortunately, there are some open source topography datasets available with reasonable resolution such as SRTM and ASTER-GDEM. In Malaysia particularly in Kuantan, the modelling research on the floodplain area is still lacking. This research aims to: a) to investigate the suitability of ASTER-GDEM to be applied in the 1D-2D flood inundation modelling for the Kuantan River Basin; b) to generate flood inundation map for Kuantan river basin. The topography dataset used in this study is ASTER-GDEM to generate physical characteristics of watershed in the basin. It is used to perform rainfall runoff modelling for hydrological studies and to delineate flood inundation area in the Flood Modeller. The results obtained have shown that a 30m resolution ASTER-GDEM is applicable as an input for the 1D-2D flood modelling. The simulated water level in 2013 has NSE of 0.644 and RSME of 1.259. As a conclusion, ASTER-GDEM can be used as one alternative topography datasets for flood inundation modelling. However, the flood level obtained from the hydraulic modelling shows low accuracy at flat urban areas.

  11. Sampling and analysis plan for the 116-C-5 retention basins characteristic dangerous waste determination

    International Nuclear Information System (INIS)

    Bauer, R.G.; Dunks, K.L.

    1996-03-01

    Cooling water flow from the rear face of the 100-B and 100-C reactors was diverted to large retention basins prior to discharge to the Columbia River. These retention basins delayed the release of the reactor coolant for decay of the short-lived activation products and for thermal cooling. Some of the activation products were deposited in sludge that settled in the basins and discharge lines. In addition, some contamination was deposited in soil around the basins and associated piping. The sampling objective of this project is to determine if regulated levels of leachable lead are present in the abrasive materials used to decontaminate the retention basin tank walls, in the material between the tank base plate and the concrete foundation, and in the soils immediately surrounding the perimeter of the retention basins. Sampling details, including sampling locations, frequencies, and analytical requirements, are discussed. Also described is the quality assurance plan for this project

  12. Rossitsa River Basin: Flood Hazard and Risk Identification

    Science.gov (United States)

    Mavrova-Guirguinova, Maria; Pencheva, Denislava

    2017-04-01

    The process of Flood Risk Management Planning and adaptation of measures for flood risk reduction as the Early Warning provoke the necessity of surveys involving Identification aspects. This project presents risk identification combining two lines of analysis: (1) Creation a mathematical model of rainfall-runoff processes in a watershed based on limited number of observed input and output variables; (2) Procedures for determination of critical thresholds - discharges/water levels corresponding to certain consequences. The pilot region is Rossitsa river basin, Sevlievo, Bulgaria. The first line of analysis follows next steps: (a) Creation and calibration of Unit Hydrograph Models based on limited number of observed data for discharge and precipitation; The survey at the selected region has 22 observations for excess rainfall and discharge. (b) The relations of UHM coefficients from the input parameters have been determined statistically, excluding the ANN model of the run-off coefficient as a function of 3 parameters (amount of precipitation two days before, soil condition, intensity of the rainfall) where a feedforward neural network is used. (c) Additional simulations with UHM aiming at generation of synthetic data for rainfall-runoff events, which extend the range of observed data; (d) Training, validation and testing a generalized regional ANN Model for discharge forecasting with 4 input parameters, where the training data set consists of synthetic data, validation and testing data sets consists of observations. A function between consequences and discharges has been reached in the second line of analysis concerning critical hazard levels determination. Unsteady simulations with the hydraulic model using three typical hydrographs for determination of the existing time for reaction from one to upper critical threshold are made. Correction of the critical thresholds aiming at providing necessary time for reaction between the thresholds and probability analysis of

  13. The Historical Flood Of July 2008 From Vaser River Basin, Romania. Causes, Effects And Flood Control Actions

    Directory of Open Access Journals (Sweden)

    Sima Andrei

    2015-10-01

    Full Text Available Floods is an experience perceived by society as unexpected, unexplainable and traumatizing and nowadays a threat to humanity more than ever. Among the natural phenomena which negatively affect human activities, floods are the ones which usually have the most significant consequences. The research, evaluations and statistics related to these phenomena do not reveal the drama and serious consequences that come with floods. It was proven that the increase of these extreme hydrological phenomena it is closely related to the anthropic activities from the area. Vaser basin is the most significant sub-basin of Vișeu river basin, contributing with 28% from the total flow of Vișeu river. Having a strong touristic and economic potential, the basin is often threatened by flash floods which usually have devastating effects. During July 2008 there was recorded the most significant flood from the history of hydrometric activity that led to substantial damage and death among locals. The present paper aims to analyze this historical flood, identifying the causes, effects, as well as the methods to control this extreme hydric phenomenon.

  14. Basin Flood Risk Management: A Territorial Data-Driven Approach to Support Decision-Making

    Directory of Open Access Journals (Sweden)

    Pedro Pinto dos Santos

    2015-02-01

    Full Text Available This paper explores the applicability of flood impact databases in the flood risk governance process. This study begins with a twofold analysis of three hydrographical basins: one analysis based on the data of a recently constructed flood-impact database for Portugal and another based on selected socioeconomic and biophysical variables that characterize the basins’ territorial context. From these sets of data, two fuzzy inference systems are assembled: one for the resource criteria and another for the time criteria. When plotted, the fuzzy analysis results are associated with distinct flood risk management strategies: operational and strategic, hard and soft measure-based. The three basins differ substantially in terms of flood-impact characteristics, with impacts being distinguished in terms of human and material consequences. Socioeconomic factors seem to be more explicative of flood impacts than the biophysical contexts that generate floods. The fuzzy logic analysis suggested priorities of action: early warning and information for one of the basins (Mondego and a less operational solution, combining structural mitigation and land-use planning, for the other two basins (Lis and Vouga. Considering the current implementation of the Floods Directive, design of flood risk maps and flood risk management plans can benefit from the integration of the presented methodology.

  15. Changes in water quality during flood waves in small mountainous river basins

    Energy Technology Data Exchange (ETDEWEB)

    Symader, W. [Trier Univ. (Germany)

    2001-07-01

    As a flood response is a reaction of the total basin to a rain impulse, the controlling factors are the characteristics of the basin, the size of the event and the pre-event conditions. This presentation focuses on summer events in small mountainous basins. Since 1988 flood response is investigated in two small basins in the Eifel and the Hunsrueck mountains. In both basins flood waves were sampled and analysed for major ions, and heavy metals in dissolved and particulate conditions, and for suspended sediment concentration and particle characteristics. In several projects the behaviour of PAHs, PCBs and pesticides in high floods were investigated as well. These investigations were accompanied by analyses of major ions and heavy metals in daily water samples and weekly samples of the river bottom sediments. (orig.)

  16. Simulating past severe flood events to evaluate the effectiveness of nonstructural flood countermeasures in the upper Chao Phraya River Basin, Thailand

    Directory of Open Access Journals (Sweden)

    Sarawut Jamrussri

    2017-04-01

    Their effectiveness in the Upper Chao Phraya River Basin was quantitatively assessed by comparing the model results for the actual conditions with the scenario results. Results showed that the proposed nonstructural measures had considerable potential to reduce peak discharges and flood volumes in the Upper Chao Phraya River Basin. Integration of these proposed nonstructural flood countermeasures with the existing countermeasures in the Chao Phraya River Basin may be the most practical way to cope with the challenges of future flood disasters.

  17. Leveraging Trillions of Pixels for Flood Mitigation Decisions Support in the Rio Salado Basin, Argentina

    Science.gov (United States)

    Sullivan, J.; Routh, D.; Tellman, B.; Doyle, C.; Tomlin, J. N.

    2017-12-01

    The Rio Salado River Basin in Argentina is an economically important region that generates 25-30 percent of Argentina's grain and meat production. Between 2000-2011, floods in the basin caused nearly US$4.5 billion in losses and affected 5.5 million people. With the goal of developing cost-efficient flood monitoring and prediction capabilities in the Rio Salado Basin to support decision making, Cloud to Street is developing satellite based analytics to cover information gaps and improve monitoring capacity. This talk will showcase the Flood Risk Dashboard developed by Cloud to Street to support monitoring and decision-making at the level of provincial and national water management agencies in the Rio Salado Watershed. The Dashboard is based on analyzing thousands of MODIS, Landsat, and Sentinel scenes in Google Earth Engine to reconstruct the spatial history of flooding in the basin. The tool, iteratively designed with the end-user, shows a history of floodable areas with specific return times, exposed land uses and population, precipitation hyetographs, and spatial and temporal flood trends in the basin. These trends are used to understand both the impact of past flood mitigation investments (i.e. wetland reconstruction) and identify shifting flood risks. Based on this experience, we will also describe best practices on making remote sensing "flood dashboards" for water agencies.

  18. Dam Construction in Lancang-Mekong River Basin Could Mitigate Future Flood Risk From Warming-Induced Intensified Rainfall: Dam Mitigate Flood Risk in Mekong

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei [Changjiang Institute of Survey, Planning, Design and Research, Wuhan China; Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Lu, Hui [Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Joint Center for Global Change Studies, Beijing China; Ruby Leung, L. [Pacific Northwest National Laboratory, Richland WA USA; Li, Hong-Yi [Department of Land Resources and Environmental Sciences and Institute on Ecosystems, Montana State University, Bozeman MT USA; Zhao, Jianshi [State Key Laboratory of Hydro-science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing China; Tian, Fuqiang [State Key Laboratory of Hydro-science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing China; Yang, Kun [Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Joint Center for Global Change Studies, Beijing China; Sothea, Khem [Mekong Institute of Cambodia, Phnom Penh Cambodia

    2017-10-25

    Water resources management, in particular flood control, in the Mekong River Basin (MRB) faces two key challenges in the 21st century: climate change and dam construction. A large scale distributed Geomorphology-Based Hydrological Model coupled with a simple reservoir regulation model (GBHM-MK-SOP) is used to investigate the relative effects of climate change and dam construction on the flood characteristics in the MRB. Results suggest an increase in both flood magnitude and frequency under climate change, which is more severe in the upstream basin and increases over time. However, dam construction and stream regulation reduce flood risk consistently throughout this century, with more obvious effects in the upstream basin where larger reservoirs will be located. The flood mitigation effect of dam regulation dominates over the flood intensification effect of climate change before 2060, but the latter emerges more prominently after 2060 and dominates the flood risk especially in the lower basin.

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

    Science.gov (United States)

    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.

  20. Impact of climate change on flood frequency and intensity in the kabul river basin

    NARCIS (Netherlands)

    Iqbal, Muhammad Shahid; Dahri, Zakir Hussain; Querner, Erik P.; Khan, Asif; Hofstra, Nynke

    2018-01-01

    Devastating floods adversely affect human life and infrastructure. Various regions of the Hindukush-Karakoram-Himalayas receive intense monsoon rainfall, which, together with snow and glacier melt, produce intense floods. The Kabul river basin originates from the Hindukush Mountains and is

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

    Science.gov (United States)

    Yüksek, Ömer; Kankal, Murat; Üçüncü, Osman

    2013-01-01

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

  2. Dynamics of dissolved organic carbon (DOC) through stormwater basins designed for groundwater recharge in urban area: Assessment of retention efficiency.

    Science.gov (United States)

    Mermillod-Blondin, Florian; Simon, Laurent; Maazouzi, Chafik; Foulquier, Arnaud; Delolme, Cécile; Marmonier, Pierre

    2015-09-15

    Managed aquifer recharge (MAR) has been developed in many countries to limit the risk of urban flooding and compensate for reduced groundwater recharge in urban areas. The environmental performances of MAR systems like infiltration basins depend on the efficiency of soil and vadose zone to retain stormwater-derived contaminants. However, these performances need to be finely evaluated for stormwater-derived dissolved organic matter (DOM) that can affect groundwater quality. Therefore, this study examined the performance of MAR systems to process DOM during its transfer from infiltration basins to an urban aquifer. DOM characteristics (fluorescent spectroscopic properties, biodegradable and refractory fractions of dissolved organic carbon -DOC-, consumption by micro-organisms during incubation in slow filtration sediment columns) were measured in stormwater during its transfer through three infiltration basins during a stormwater event. DOC concentrations sharply decreased from surface to the aquifer for the three MAR sites. This pattern was largely due to the retention of biodegradable DOC which was more than 75% for the three MAR sites, whereas the retention of refractory DOC was more variable and globally less important (from 18% to 61% depending on MAR site). Slow filtration column experiments also showed that DOC retention during stormwater infiltration through soil and vadose zone was mainly due to aerobic microbial consumption of the biodegradable fraction of DOC. In parallel, measurements of DOM characteristics from groundwaters influenced or not by MAR demonstrated that stormwater infiltration increased DOC quantity without affecting its quality (% of biodegradable DOC and relative aromatic carbon content -estimated by SUVA254-). The present study demonstrated that processes occurring in soil and vadose zone of MAR sites were enough efficient to limit DOC fluxes to the aquifer. Nevertheless, the enrichments of DOC concentrations measured in groundwater below

  3. Flood modeling using WMS model for determining peak flood discharge in southwest Iran case study: Simili basin in Khuzestan Province

    Science.gov (United States)

    Hoseini, Yaser; Azari, Arash; Pilpayeh, Alireza

    2017-10-01

    It is of high importance to determine the flood discharge of different basins, in studies on water resources. However, it is necessary to use new models to determine flood hydrograph parameters. Therefore, it will be beneficial to conduct studies to calibrate the models, keeping in mind the local conditions of different regions. Therefore, this study was carried out to determine the peak flood discharge of a basin located in Southwest Iran, using the TR-20, TR55, and HEC-1 methods of the WMS model (watershed modeling system). The obtained results were compared with empirical values, as well as those of the soil conservation service (SCS) approach. Based on the results obtained, the TR55 method of the WMS model recorded the highest agreement with empirical values in Southwest Iran.

  4. On-farm flood capture could reduce groundwater overdraft in Kings River Basin

    Directory of Open Access Journals (Sweden)

    Philip A.M. Bachand

    2016-11-01

    Full Text Available Chronic groundwater overdraft threatens agricultural sustainability in California's Central Valley. Diverting flood flows onto farmland for groundwater recharge offers an opportunity to help address this challenge. We studied the infiltration rate of floodwater diverted from the Kings River at a turnout upstream of the James Weir onto adjoining cropland; and calculated how much land would be necessary to capture the available floodwater, how much recharge of groundwater might be achieved, and the costs. The 1,000-acre pilot study included fields growing tomatoes, wine grapes, alfalfa and pistachios. Flood flows diverted onto vineyards infiltrated at an average rate of 2.5 inches per day under sustained flooding. At that relatively high infiltration rate, 10 acres are needed to capture one CFS of diverted flood flow. We considered these findings in the context of regional expansion. Based upon a 30-year record of Kings Basin surplus flood flows, we estimate 30,000 acres operated for on-farm flood recharge would have had the capacity to capture 80% of available flood flows and potentially offset overdraft rates in the Kings Basin. Costs of on-farm flood capture for this study were estimated at $36 per acre-foot, less than the cost for surface water storage and dedicated recharge basins.

  5. Evolvement rules of basin flood risk under low-carbon mode. Part II: risk assessment of flood disaster under different land use patterns in the Haihe basin.

    Science.gov (United States)

    Li, Fawen; Wang, Liping; Zhao, Yong

    2017-08-01

    Land use pattern contains a large amount of information about the flood hazard-formative environments, which is the most sensitive factor in hazard-formative environments. In this paper, based on the land use pattern in 2008 (the base year) and in 2020 (the planning year), the comparative analysis of flood disaster risk changes in Haihe basin were studied by the spatial analysis function of ARCGIS and the analytic hierarchy process (AHP). The results showed the flood disaster risk in Haihe basin had an obvious zonality in the space, among which low risk was located in the northwest regions, and high risk was located in the southeast regions. Flood disaster risk in planning year was lower than in the base year. The risk value of 2020 in the mountain decreases from 0.445 to 0.430, while the risk value of the plain increases from 0.562 to 0.564. For the plain, high-risk area in 2020 is increased by 13.2%, which is the biggest change in risk grades. For the mountain, low-risk area and low risk area in 2020 are increased, and the low-risk area is the biggest increase, up to 37.7%. Meanwhile, high-risk area, high risk area, and medium risk area all tend to decrease, and the high-risk area is the biggest decrease, up to 32.6%. Overall, land use planning pattern under low-carbon mode is conducive to the Haihe basin flood control. The research can provide scientific foundations for basin land use planning and flood disaster risk management.

  6. Methylmercury Modulation in Amazon Rivers Linked to Basin Characteristics and Seasonal Flood-Pulse.

    Science.gov (United States)

    Kasper, Daniele; Forsberg, Bruce R; Amaral, João H F; Py-Daniel, Sarah S; Bastos, Wanderley R; Malm, Olaf

    2017-12-19

    We investigated the impact of the seasonal inundation of wetlands on methylmercury (MeHg) concentration dynamics in the Amazon river system. We sampled 38 sites along the Solimões/Amazon and Negro rivers and their tributaries during distinct phases of the annual flood-pulse. MeHg dynamics in both basins was contrasted to provide insight into the factors controlling export of MeHg to the Amazon system. The export of MeHg by rivers was substantially higher during high-water in both basins since elevated MeHg concentrations and discharge occurred during this time. MeHg concentration was positively correlated to %flooded area upstream of the sampling site in the Solimões/Amazon Basin with the best correlation obtained using 100 km buffers instead of whole basin areas. The lower correlations obtained with the whole basin apparently reflected variable losses of MeHg exported from upstream wetlands due to demethylation, absorption, deposition, and degradation before reaching the sampling site. A similar correlation between %flooded area and MeHg concentrations was not observed in the Negro Basin probably due to the variable export of MeHg from poorly drained soils that are abundant in this basin but not consistently flooded.

  7. Integrated Flood Risk Assessment of Rural Communities in the Oti River Basin, West Africa

    Directory of Open Access Journals (Sweden)

    Kossi Komi

    2016-11-01

    Full Text Available Flood damage in West Africa has increased appreciably during the last two decades. Poor communities are more at risk due to the vulnerability of their livelihoods, especially in rural areas where access to services and infrastructures is limited. The aim of this paper is to identify the main factors that contribute to flood risk of rural communities in the Oti River Basin, Togo. A community-based disaster risk index model is applied. The analyses use primary data collected through questionnaires during fieldwork, the analytic hierarchy process (AHP method, population and housing census data and flood hazard mapping of the study area. The results showed a moderate level of flood risk despite a high level of hazard and vulnerability for all investigated communities. In addition, the results suggest that decreasing vulnerability through creation of new income-generating opportunities and increasing capacity of communities to manage their own flood risk should be paramount in order to reduce flood risk in the study area. The results of this work contribute to the understanding of flood risk and can be used to identify, assess, and compare flood-prone areas, as well as simulating the impacts of flood management measures in the Oti River Basin.

  8. Morphometric analysis of Colangüil river basin and flash flood hazard, San Juan, Argentina

    Science.gov (United States)

    Esper Angillieri, María Yanina

    2008-07-01

    This work analyzes various morphometric characteristics of the Colangüil river basin in order to evaluate flash flood hazards. Such high-water events pose a risk to the similarly named small village located at the basin’s foot area. For this purpose, the basin is divided into seven sub-basins and some basic measurements (surface, perimeter, basin length, river beds, elevations and slope of the main river bed, and of a number of minor river beds) are calculated. These measurements permit to predict approximately the behavior of the basin in the presence of a series of theoretical rainstorms that may generate unusual runoff volumes that make up such flash floods.

  9. An investigation of basin effects on flood discharges in North Dakota

    Science.gov (United States)

    Crosby, Orlo A.

    1974-01-01

    An investigation of the relationship of peak discharge to causative storm variables and drainage-basin characteristics was made to provide guidelines for future analyses of frequency and magnitudes of floods from small drainage areas. The procedure used was (l) to estimate peak discharges on the ll study basins from multiple-regression models developed from the storm variables and (2) to relate the peak discharges to the basin characteristics through regression or correlation with particular attention given to the effect of basin shape.

  10. FLOOD RUNOFF CHARACTERISTIC CHANGE OVER 50 YEARS BY TREE SPECIES CONVERSION IN UPPER DOZANGAWA RIVER BASIN

    Science.gov (United States)

    Ogawa, Ken-Ichiro; Tamura, Takao; Takigawa, Noriko; Kuwahara, Masato; Takanishi, Syunji

    This study conducted runoff analysis for the floods in Sep. 1954 and Oct. 2004 by the distributed runoff model for Yanase Dam basin in the upper Douzangawa River, where once become devastated by an operation of Besshi copper mine and recovered by afforestation and tree species conversion. Subsequently, a relationship between the tree species conversion over 50 years and changes of flood runoff characteristics, and a reduction effect of forest in peak discharge of flood were examined.As a conclusion, authors presumed approximately 20 percent improvement of the peak discharge reduction by tree species conversion. It was supposed that the difference of flood runoff characteristic were explained by parameters in relation to rainfall interception and evaporation function of forest, and in Yanase Dam basin, the change of tree density sensitively influenced on runoff characteristics.

  11. Effects of Flood Control Works Failure in the Missouri River Basin

    Science.gov (United States)

    2014-06-13

    hydrologist with the National Resources Conservation Service; Bill Lawrence, a hydrologist with the National Weather Service; and Darwin Ockerman, a...Levee Unit R -550. The levee, located near Brownville, Nebraska, overtopped by one to two feet, and subsequently breached on the morning of 24 July...duration of flooding in the Missouri River basin occurred in Saint Charles , Missouri. The Missouri River at Saint Charles stayed at or above flood

  12. Urban flood mitigation planning for Guwahati: A case of Bharalu basin.

    Science.gov (United States)

    Sarmah, Tanaya; Das, Sutapa

    2018-01-15

    Guwahati, the capital city of Assam and the gateway to the seven north-eastern Indian states, is located in the Brahmaputra valley-one of the most flood prone regions of the world. The city receives an average annual rainfall of 1688 mm and is highly vulnerable towards frequent urban floods because of uncontrolled dumping of solid waste and siltation have choked the natural water channels. This coupled with the absence of an integrated drainage network and rapid urbanisation causes floods in many parts of the city, after a quick downpour. Bharalu river is the main natural water channel of the city and Bharalu basin is the most vulnerable one. The present paper is an attempt to plan for urban flood mitigation, by designing an integrated drainage network for the Bharalu basin which includes the low-lying urbanized areas bordered by the Guwahati-Shillong Road, the Radha Gobindo Baruah Road and the Rajgarh Road. Data regarding land use, flood level, rainfall, urban pattern and vulnerability towards urban flood were collected from available literature, field survey to find highest water level for 11.4 km road stretch, expert opinion survey from 18 experts and feedback from 77 community elders who have been residing in the city since the 1980s. The Bharalu basin is divided into seven drainage blocks and storm run-off has been calculated based on the inputs. Seven different trapezoidal drainage sections were designed to form an integrated drainage network which is 'self-healing' to a certain extent. This can serve as a template for the other catchment basins and to design a drainage network for the entire Guwahati city, thereby reducing urban flood hazard to a significant extent. The study illustrates the necessity of an urban flood mitigation planning approach in sub-Himalayan urban settlements such as Guwahati. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Flood Risk Assessment and Forecasting for the Ganges-Brahmaputra-Meghna River Basins

    OpenAIRE

    Young, William; Avasthi, Ankit; Priya, Satya; Hopson, Thomas

    2017-01-01

    The Ganges Basin in South Asia is home to some of the world's poorest and most vulnerable communities. Impacted by catastrophic annual floods, the region is recognized as highly disaster prone, causing widespread human suffering and economic losses. In recognition of these challenges, many groups are actively and cooperatively engaged in reducing South Asia's vulnerability to flooding. As a contribution to these efforts, the World Bank recently commissioned specialist teams to assess and map ...

  14. Thermo-hydrodynamical modelling of a flooded deep mine reservoir - Case of the Lorraine Coal Basin

    International Nuclear Information System (INIS)

    Reichart, Guillaume

    2015-01-01

    Since 2006, cessation of dewatering in Lorraine Coal Basin (France) led to the flooding of abandoned mines, resulting in a new hydrodynamic balance in the area. Recent researches concerning geothermal exploitation of flooded reservoirs raised new questions, which we propose to answer. Our work aimed to understand the thermos-hydrodynamic behaviour of mine water in a flooding or flooded system. Firstly, we synthesized the geographical, geological and hydrogeological contexts of the Lorraine Coal Basin, and we chose a specific area for our studies. Secondly, temperature and electric conductivity log profiles were measured in old pits of the Lorraine Coal Basin, giving a better understanding of the water behaviour at a deep mine shaft scale. We were able to build a thermos-hydrodynamic model and simulate water behaviour at this scale. Flow regime stability is also studied. Thirdly, a hydrodynamic spatialized meshed model was realized to study the hydrodynamic behaviour of a mine reservoir as a whole. Observed water-table rise was correctly reproduced: moreover, the model can be used in a predictive way after the flooding. Several tools were tested, improved or developed to ease the study of flooded reservoirs, as three-dimensional up-scaling of hydraulic conductivities and a coupled spatialized meshed model with a pipe network. (author) [fr

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

    Science.gov (United States)

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

    2017-04-01

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

  16. Flood risk projection for large river basins with delta in Southeast Asia

    Science.gov (United States)

    Kanae, S.; Sato, T.; Lim, W.; Koirala, S.; Roobavannan, M.; Hirabayashi, Y.; Yamazaki, D.

    2013-12-01

    The risk of floods would increase under the changing climate. It was reported that the frequency of 20th-century's 100-year floods would largely increase in Southeast Asia including the Mekong. This study tries to estimate the change in flood risk under the latest climate change scenarios for the Mekong river basin and some other similar rivers that have unique features and social importance. The impact of population change, socio-economic growth, and/or sea level rise would be discussed.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2017-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Hejia Wang

    2016-03-01

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

  20. Indicators for hydraulic and pollution retention assessment of stormwater infiltration basins.

    Science.gov (United States)

    Dechesne, Magali; Barraud, Sylvie; Bardin, Jean-Pascal

    2004-07-01

    Infiltration basins are frequently used for stormwater management even though their long-term evolution is not well understood nor controlled. The two main problems encountered are clogging which compromises the hydraulic capacity of the basin and possible contamination of underlying soil and groundwater. This paper defines a framework for evaluating the hydraulic and pollution retention performance of infiltration basins in the long-term. Sets of context and performance indicators are proposed, along with two complementary modes of evaluation. Context indicators are identified in order to define the clogging and contamination states of the basins. Performance indicators are developed to assess several aspects of basin performance: drainage duration, overflow frequency, predictive life period, particle filtration and pollution trapping. Modes of evaluation include field investigation and long-term simulation modeling. Indicators are tested on five infiltration basins in suburban Lyon (France). Both context indicators and hydraulic performance indicators are reliable and their evaluation is representative of basin behavior. This is not the case for pollution retention performance indicators. Their assessment is difficult because of data quality. Field data has high uncertainties. The model is satisfactory for the hydraulic simulation and the evolution of clogging. Improvements are necessary for pollution flow simulation and the acquisition of better quality data is required.

  1. Long-term Simulation of the Removal of Pollutants in Retention Basins

    DEFF Research Database (Denmark)

    Larsen, Torben; Neerup-Jensen, Ole; Kaasgaard, Mogens

    2005-01-01

    The paper describes a method for the long-term simulation of the discharge of pollutants to the environment from storm sewer overflows in combined sewer systems, which has a connected retention basin. This study covers Cd, Cu, Ni, Pb, Zn and PAH. The method includes both the influence of the flow...

  2. Application of Integrated Flood Analysis System (IFAS) for Dungun River Basin

    International Nuclear Information System (INIS)

    Hafiz, I; Nor, N D M; Sidek, L M; Basri, H; F K; Hanapi, M N; Livia L

    2013-01-01

    The Northeast monsoon happening during the months of October until January is the major rainy season found in the eastern part of Peninsular Malaysia. The Dungun river basin (1,858 km 2 ) is exposed to this season thus experiencing characteristically regular flooding due to the prolong rainfall events. The annual rainfall over the river basins are 2,880 mm with great proportion falling in the months of December (19.4%). This study is to apply the Integrated Flood Analysis System (IFAS) model which Dungun river basin has been chosen for this study as the catchments have range of flood and relevant data that can be used to develop the model. The satellite data used in this study is provided by JAXA Global Rainfall Watch. The main feature of this real-time flood analysis model is the satellite-based rainfall data input employed during the model creation phase. The performance of the model for the river basins from satellite and ground-based rainfall data are compared using three error analysis methods.

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

    Science.gov (United States)

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

    2017-12-01

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

  4. Quantifying the in-channel retention of cohesive sediments during artificial flood events using FTIR-DRIFT spectrometry

    Science.gov (United States)

    Kurtenbach, A.; Gallé, T.; Buis, K.; de Sutter, R.; Troch, P.; Eisold, B.; Bierl, R.; Symader, W.

    2010-05-01

    Cohesive sediments control river ecosystem quality both as a transport medium for contaminants and as clogging material of stream bottom habitats. However, experimental field studies with fine-grained sediments in fluvial systems are rather scarce owing to the lack of adequate tracers and detection methods. As a result, current modelling approaches only insufficiently describe hydrodynamic transport and depositional behaviour of fine-grained sediments in rivers. We adopted two strategies to specifically study cohesive sediment dynamics in natural systems under defined boundary conditions. First, artificial floods were generated in the Olewiger Bach basin (24 km²), a mid-mountain gravel bed river, in order to characterise the in-channel fine sediment dynamics on their own. The advantage of these artificial flood waves lies in the selective control on some governing processes by experimental design. Second, fine sediment transport and deposition during these controlled reservoir releases were analysed by introducing the clay mineral kaolinite as a fine particle tracer, whose concentration was measured by Fourier transform infrared spectroscopy (FTIR) in diffuse reflectance mode (DRIFT). The DRIFT technique offers some important advantages such as the ability to assess both mineral and organic structures in aquatic particles, good sensitivity and high throughput (Gallé et al. 2004). Our laboratory tests confirm that FTIR-DRIFT spectrometry is capable of detecting the kaolinite tracer even in low percentage solid concentrations. The mass balance of the injected kaolinite for near bank-full artificial floods showed that, in spite of the very fine material and the non-stationary boundary conditions, over 50 percent of the tracer could be retained over a flow length of only 500 m. By combining fine particulate and natural dissolved tracers (e.g. dissolved organic carbon, DOC) we were able to identify the hyporheic zone as a potential short-term retention and storage

  5. Regional L-Moment-Based Flood Frequency Analysis in the Upper Vistula River Basin, Poland

    Science.gov (United States)

    Rutkowska, A.; Żelazny, M.; Kohnová, S.; Łyp, M.; Banasik, K.

    2017-02-01

    The Upper Vistula River basin was divided into pooling groups with similar dimensionless frequency distributions of annual maximum river discharge. The cluster analysis and the Hosking and Wallis (HW) L-moment-based method were used to divide the set of 52 mid-sized catchments into disjoint clusters with similar morphometric, land use, and rainfall variables, and to test the homogeneity within clusters. Finally, three and four pooling groups were obtained alternatively. Two methods for identification of the regional distribution function were used, the HW method and the method of Kjeldsen and Prosdocimi based on a bivariate extension of the HW measure. Subsequently, the flood quantile estimates were calculated using the index flood method. The ordinary least squares (OLS) and the generalised least squares (GLS) regression techniques were used to relate the index flood to catchment characteristics. Predictive performance of the regression scheme for the southern part of the Upper Vistula River basin was improved by using GLS instead of OLS. The results of the study can be recommended for the estimation of flood quantiles at ungauged sites, in flood risk mapping applications, and in engineering hydrology to help design flood protection structures.

  6. Flood Risk Assessment and Forecasting for the Ganges-Brahmaputra-Meghna River Basins

    Science.gov (United States)

    Hopson, T. M.; Priya, S.; Young, W.; Avasthi, A.; Clayton, T. D.; Brakenridge, G. R.; Birkett, C. M.; Riddle, E. E.; Broman, D.; Boehnert, J.; Sampson, K. M.; Kettner, A.; Singh, D.

    2017-12-01

    During the 2017 South Asia monsoon, torrential rains and catastrophic floods affected more than 45 million people, including 16 million children, across the Ganges-Brahmaputra-Meghna (GBM) basins. The basin is recognized as one of the world's most disaster-prone regions, with severe floods occurring almost annually causing extreme loss of life and property. In light of this vulnerability, the World Bank and collaborators have contributed toward reducing future flood impacts through recent developments to improve operational preparedness for such events, as well as efforts in more general preparedness and resilience building through planning based on detailed risk assessments. With respect to improved event-specific flood preparedness through operational warnings, we discuss a new forecasting system that provides probability-based flood forecasts developed for more than 85 GBM locations. Forecasts are available online, along with near-real-time data maps of rainfall (predicted and actual) and river levels. The new system uses multiple data sets and multiple models to enhance forecasting skill, and provides improved forecasts up to 16 days in advance of the arrival of high waters. These longer lead times provide the opportunity to save both lives and livelihoods. With sufficient advance notice, for example, farmers can harvest a threatened rice crop or move vulnerable livestock to higher ground. Importantly, the forecasts not only predict future water levels but indicate the level of confidence in each forecast. Knowing whether the probability of a danger-level flood is 10 percent or 90 percent helps people to decide what, if any, action to take. With respect to efforts in general preparedness and resilience building, we also present a recent flood risk assessment, and how it provides, for the first time, a numbers-based view of the impacts of different size floods across the Ganges basin. The findings help identify priority areas for tackling flood risks (for

  7. MAFURIKO : Design of Nzoia Basin location based flood game

    NARCIS (Netherlands)

    Onencan, A.M.; Kortmann, L.J.; Kulei, F.; Enserink, B.

    2016-01-01

    Every 2 to 7 years, Kenya experiences a reoccurrence of El-Niño rains leading to loss of life and massive damage to property. The 1997/98 El-Niño floods affected 1.5 million persons and led to an estimated USD 1.2 billion infrastructural damage, USD 236 million agricultural damage and USD 9

  8. RESRAD soil concentration guidelines for the Old F-Area Retention Basin

    International Nuclear Information System (INIS)

    Hamby, D.M.

    1994-01-01

    Concentration guidelines for residual radionuclides in soil at the site of the Old F-Area Retention Basin have been calculated using a dose-based approach. Estimation of these soil guidelines was completed using RESRAD 5.0 in accordance with the DOE RESRAD methodology specified in DOE/CH/8901. Guidelines are provided for the two predominant nuclides, Sr-90 and Cs-137, known to be present in the soil beneath the old basin. A guideline is also given for Pu-238 since it is known to exist at the H-Area Retention Basin. Site-specific soil characteristics are defined for the areas above, within, and beneath the contaminated zone

  9. Attribution of floods in the Okavango basin, Southern Africa

    Science.gov (United States)

    Wolski, Piotr; Stone, Dáithí; Tadross, Mark; Wehner, Michael; Hewitson, Bruce

    2014-04-01

    In the charismatic wetlands of the Okavango Delta, Botswana, the annual floods of 2009-2011 reached magnitudes last seen 20-30 years ago, considerably affecting life of local populations and the economically important tourism industry. In this study, we analyse results from an attribution modelling system designed to examine how anthropogenic greenhouse gas emissions have contributed to weather and flood risk in our current climate. The system is based on comparison of real world climate and hydrological simulations with parallel counterfactual simulations of the climate and hydrological responses under conditions that might have been had human activities not emitted greenhouse gases. The analyses allow us to address the question of whether anthropogenic climate change contributed to increasing the risk of these high flood events in the Okavango system. Results show that the probability of occurrence of high floods during 2009-2011 in the current climate is likely lower than it would have been in a climate without anthropogenic greenhouse gases. This result is robust across the two climate models and various data processing procedures, although the exact figures for the associated decrease in risk differ. Results also differ between the three years examined, indicating that the “time-slice” method used here needs to be applied to multiple years in order to accurately estimate the contribution of emissions to current risk. Simple sensitivity analyses indicate that the reduction in flood risk is attributed to higher temperatures (and thus evaporation) in the current world, with little difference in the analysed domain's rainfall simulated in the two scenarios.

  10. Submarine Flood Basalt Eruptions and Flows of Ontong Java Plateau, Nauru Basin and East Mariana Basin

    Science.gov (United States)

    Michael, P. J.; Trowbridge, S. R.; Zhang, J.; Johnson, A. L.

    2016-12-01

    The preservation of fresh basalt glasses from the submarine Cretaceous Ontong Java Plateau (OJP), Earth's largest LIP, has allowed correlation of precise lava compositions over 100s of km, as well as determination of eruption depths using dissolved H2O and CO2 contents. Low dissolved H2O in glasses shows that H2O in the mantle source is low [1,2], suggesting mantle temperatures are high. Very high dissolved Cl indicates that magmas interacted extensively with brines. The near total absence of vesicles in OJP glasses contrasts sharply with MORB, and suggests that OJP lavas were saturated or undersaturated with CO2 when they were emplaced, in contrast to MORB that are often oversaturated. The lavas likely remained liquid for a longer period of time so that they degassed to equilibrium levels of dissolved CO2 andlost all bubbles. Very precise major and trace element analyses of glasses, uncomplicated by crystals or alteration, show how lavas within and between widely-spaced drill holes could be related. For example, glasses from Sites 1185B and 1186A, which are about 200 km apart, are compositionally identical within precise limits and must have erupted from the same well-mixed magma chamber. They erupted at about the same depth, but 1186A has a corrected basement depth that is >700m deeper. With a slope of 0.3°, this suggests a flow distance >130km. The eruption depths for glasses from East Mariana and Nauru Basins are similar to those of 1185B and 1186A on OJP, even though their reconstructed basement depths are about 2000 m deeper. It suggests that the plateau lavas flowed into the basins. Similarly, eruption depths in Hole 807C are 3040m for Kwaimbaita lavas but are 1110m [1,2] for Singgalo lavas that directly overlie them. It is unlikely that plateau uplift and subsidence accounts for the observed eruption depths. All of these observations are best explained by very large-volume eruptions whose lavas traveled for long distances, up to 100s of km, into deeper

  11. FLOOD RISK ASSESSMENT IN RIVER TIMIS BASIN - THE CARANSEBES - LUGOJ SECTOR- USING GIS TECHNIQUE

    Directory of Open Access Journals (Sweden)

    MIHAI VALENTIN HERBEI

    2012-11-01

    Full Text Available Flood risk assessment in Timis River basin - the Caransebes -Lugoj sector- using GIS technique. Over time freshets, thus floods constituted and constitute a particularly important issue that requires attention. In many cases, flood damages are extensive to the environment, to the economy and also socially. The purpose of this paper is to identify flood-prone areas between Caransebes and Lugoj, land that is part of the Timis river basin. This paper is based on a theoretical model in which we considered the building elements of the flood produced on the Timis river in April 2005 (levels and flows. to represent the zones flood – prone, we used the numerical model of the terrain, created for the abovementioned area. On this model , according to levels measured at hydrometric stations, were defined those flood prone areas. The Timis river hydrographic basin includes a varied terrain (mountains, hills and plains, with pronounced differences in altitude and massiveness, resulting from tectonic movements that have affected the region, this fact has affected water flow processes, both directly through fragmentation and slope, and indirectly, by creating the vertical climate, vegetation and soils zones. Using GIS technology to study hydrological phenomena and their impact on the geographic area are of particular importance due to the complexity of these techniques, which enables detailed analysis and analytical precision as well as an increased speed of the analysis. Creating theoretical models that give scale to the hydrological phenomena, in this case representing the flood areas, is of great practical importance because based on these models the areas can be defined and viewed, having the possibility of taking measures to prevent environmental effects on the natural and / or anthropogenic environment. In the studied area review of the flood of 2005, were represented flood areas, therefore, according with the researches, several villages, located in

  12. Potential for AP600 in-vessel retention through ex-vessel flooding

    Energy Technology Data Exchange (ETDEWEB)

    Rempe, J.L.; Knudson, D.L.; Allison, C.M.; Thinnes, G.L.; Atwood, C.L.

    1997-12-01

    External reactor vessel cooling (ERVC) is a new severe accident management strategy that involves flooding the reactor cavity to submerge the reactor vessel in an attempt to cool core debris that has relocated to the vessel lower head. Advanced and existing light water reactors (LWRs) are considering ERVC as an accident management strategy for in-vessel retention (IVR) of relocated debris. In the probabilistic risk assessment (PRA) for the AP600 design, Westinghouse credits ERVC for preventing vessel failure during postulated severe accidents with successful reactor coolant system (RCS) depressurization and reactor cavity flooding. To support the Westinghouse position on IVR, DOE contracted the University of California--Santa Barbara (UCSB) to produce the peer-reviewed report. To assist in the NRC`s evaluation of IVR of core melt by ex-vessel flooding of the AP6OO, the Idaho National Engineering and Environmental Laboratory (INEEL) was tasked to perform: An in-depth critical review of the UCSB study and the model that UCSB used to assess ERVC effectiveness; An in-depth review of the UCSB study peer review comments and of UCSB`s resolution method to identify areas where technical concerns weren`t addressed; and An independent analysis effort to investigate the impact of residual concerns on the margins to failure and conclusions presented in the UCSB study. This report summarizes results from these tasks. As discussed in Sections 1.1 and 1.2, INEEL`s review of the UCSB study and peer reviewer comments suggested that additional analysis was needed to assess: (1) the integral impact of peer reviewer-suggested changes to input assumptions and uncertainties and (2) the challenge present by other credible debris configurations. Section 1.3 summarized the corresponding analysis approach developed by INEEL. The remainder of this report provides more detailed descriptions of analysis methodology, input assumptions, and results.

  13. Soil and nutrient retention in winter-flooded ricefields with implications for watershed management

    Science.gov (United States)

    Manley, S.W.; Kaminski, R.M.; Rodrigue, P.B.; Dewey, J.C.; Schoenholtz, S.H.; Gerard, P.D.; Reinecke, K.J.

    2009-01-01

    The ability of water resources to support aquatic life and human needs depends, in part, on reducing nonpoint source pollution amid contemporary agricultural practices. Winter retention of shallow water on rice and other agricultural fields is an accepted management practice for wildlife conservation; however, soil and water conservation benefits are not well documented. We evaluated the ability of four post-harvest ricefield treatment combinations (stubble-flooded, stubble-open, disked-flooded and disked-open) to abate nonpoint source exports into watersheds of the Mississippi Alluvial Valley. Total suspended solid exports were 1,121 kg ha-1 (1,000 lb ac-1) from disked-open fields where rice stubble was disked after harvest and fields were allowed to drain, compared with 35 kg ha-1 (31 lb ac-1) from stubble-flooded fields where stubble was left standing after harvest and fields captured rainfall from November 1 to March 1. Estimates of total suspended solid exports from ricefields based on Landsat imagery and USDA crop data are 0.43 and 0.40 Mg km-2 day-1 in the Big Sunflower and L'Anguille watersheds, respectively. Estimated reductions in total suspended solid exports from ricefields into the Big Sunflower and L'Anguille water-sheds range from 26% to 64% under hypothetical scenarios in which 65% to 100% of the rice production area is managed to capture winter rainfall. Winter ricefield management reduced nonpoint source export by decreasing concentrations of solids and nutrients in, and reducing runoff volume from, ricefields in the Mississippi Alluvial Valley.

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

    Science.gov (United States)

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

    2017-10-01

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

  15. Identification of stakeholder perspectives on future flood management in the Rhine basin using Q methodology

    Science.gov (United States)

    Raadgever, G. T.; Mostert, E.; van de Giesen, N. C.

    2008-08-01

    This article identifies different stakeholder perspectives on future flood management in the downstream parts of the Rhine basin in Germany and The Netherlands. The perspectives were identified using Q methodology, which proved to be a good, but time-intensive, method for eliciting and analyzing stakeholder perspectives in a structured and unbiased way. Three shared perspectives were found: A) "Anticipation and institutions", B) "Space for flooding" and C) "Knowledge and engineering". These three perspectives share a central concern for the provision of safety against flooding, but disagree on the expected autonomous developments and the preferred measures. In perspective A, the expected climate change and economic growth call for fast action. To deal with the increasing flood risk, mostly institutional measures are proposed, such as the development of a stronger basin commission. In perspective B, an increasing spatial pressure on the river area is expected, and the proposed measures are focused on mitigating damage, e.g., through controlled flooding and compartmentalization. In perspective C, the role of expert knowledge and technological improvements is emphasized. Preferred strategies include strengthening the dikes and differentiation of safety standards. An overview of stakeholder perspectives can be useful in natural resources management for 1) setting the research agenda, 2) identifying differences in values and interests that need to be discussed, 3) creating awareness among a broad range of stakeholders, and 4) developing scenarios.

  16. Guidelines for acceptable soil concentrations in the old F- and H-Area Retention Basins

    International Nuclear Information System (INIS)

    Hamby, D.M.

    1994-01-01

    Concentration guidelines for residual radionuclides in soil at the sites of the Old F- and H-Area Retention Basins (281-3F, 281-3H) have been calculated using a dose-based approach. The guidelines also are being applied to areas around the F-Basin's Process Line. Estimation of these soil guidelines was completed using RESRAD 5.0 in accordance with the DOE RESRAD methodology specified in DOE/CH/8901 (Gi89). Guidelines are provided for the nuclides known to be present in the soils at each basin (Sc87). Soil and hydrologic characteristics specific to each basin are defined for the areas above, within, and beneath the contaminated zones

  17. Collaborative GIS for flood susceptibility mapping: An example from Mekong river basin of Viet Nam

    Science.gov (United States)

    Thanh, B.

    2016-12-01

    Flooding is one of the most dangerous natural disasters in Vietnam. Floods have caused serious damages to people and made adverse impact on social economic development across the country, especially in lower river basin where there is high risk of flooding as consequences of the climate change and social activities. This paper presents a collaborative platform of a combination of an interactive web-GIS framework and a multi-criteria evaluation (MCE) tool. MCE is carried out in server side through web interface, in which parameters used for evaluation are groups into three major categories, including (1) climatic factor: precipitation, typhoon frequency, temperature, humidity (2) physiographic data: DEM, topographic wetness index, NDVI, stream power index, soil texture, distance to river (3) social factor: NDBI, land use pattern. Web-based GIS is based on open-source technology that includes an information page, a page for MCE tool that users can interactively alter parameters in flood susceptible mapping, and a discussion page. The system is designed for local participation in prediction of the flood risk magnitude under impacts of natural processes and human intervention. The proposed flood susceptibility assessment prototype was implemented in the Mekong river basin, Viet Nam. Index images were calculated using Landsat data, and other were collected from authorized agencies. This study shows the potential to combine web-GIS and spatial analysis tool to flood hazard risk assessment. The combination can be a supportive solution that potentially assists the interaction between stakeholders in information exchange and in disaster management, thus provides for better analysis, control and decision-making.

  18. Long Term Estimates of Removal of Heavy Metals and PAH in Retention Basins

    DEFF Research Database (Denmark)

    Larsen, Torben; Neerup-Jensen, O.

    2004-01-01

    The paper describes a method for the long-term simulation of the discharge of pollutants to the environment from storm sewer overflows in combined sewer systems, which have a connected retention basins. This study covers heavy metals (Cd, Cu, Ni, Pb, Zn) and PAH. The method includes both...... the influence of the flow-dependant sedimentation and the variation of the settling velocity of the particles. The results show that including these effects lead to significant lower discharges of pollutants compared to conventional methods of estimation. As an example computations with a spectrum of basins...

  19. Mine flooding and barrier pillar hydrology in the Pittsburgh basin

    International Nuclear Information System (INIS)

    Leavitt, B.R.

    1999-01-01

    Pennsylvania began requiring barrier pillars between mines as early as 1930. The Ashley formula, resulting from a early commission on the problem, requires 20 feet of coal plus a thickness of coal equal to four times the seam height plus an additional thickness of coal equal to one tenth of the overburden thickness, or the maximum potential hydraulic head. For a 6-foot thick coal seam under 400 feet of cover, the barrier would be 20+24+40=84 feet. The Ashley formula is intended to protect coal miners from a catastrophic failure of a barrier pillar which has a high head of water impounded behind it. The paper gives several examples of flooded and unflooded mines and the performance of their barrier pillars with respect to acid mine drainage. It is concluded that for all practical purposes, barrier pillars designed with the Ashley formula are able to hydrologically isolate mines from one another. This hydrologic isolation promotes the inundation of closed mines. Inundation effectively stops acid formation, thus, fully inundated mines do not represent a perpetual source of acid mine drainage. Infiltrating ground water improves the mine water chemistry resulting in a net alkaline discharge which has greatly lowered iron concentrations. The best locations for acid mine drainage treatment plants is at the lowest surface elevation above the mine with mine flooded to near that elevation

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

    Science.gov (United States)

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

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

  1. The ordered network structure and its prediction for the big floods of the Changjiang River Basins

    International Nuclear Information System (INIS)

    Men, Ke-Pei; Zhao, Kai; Zhu, Shu-Dan

    2013-01-01

    According to the latest statistical data of hydrology, a total of 21 floods took place over the Changjiang (Yangtze) River Basins from 1827 to 2012 and showed an obvious commensurable orderliness. In the guidance of the information forecasting theory of Wen-Bo Weng, based on previous research results, combining ordered analysis with complex network technology, we focus on the summary of the ordered network structure of the Changjiang floods, supplement new information, further optimize networks, construct the 2D- and 3D-ordered network structure and make prediction research. Predictions show that the future big deluges will probably occur over the Changjiang River Basin around 2013-2014, 2020-2021, 2030, 2036, 2051, and 2058. (orig.)

  2. Development of river flood model in lower reach of urbanized river basin

    Science.gov (United States)

    Yoshimura, Kouhei; Tajima, Yoshimitsu; Sanuki, Hiroshi; Shibuo, Yoshihiro; Sato, Shinji; Lee, SungAe; Furumai, Hiroaki; Koike, Toshio

    2014-05-01

    Japan, with its natural mountainous landscape, has demographic feature that population is concentrated in lower reach of elevation close to the coast, and therefore flood damage with large socio-economic value tends to occur in low-lying region. Modeling of river flood in such low-lying urbanized river basin is complex due to the following reasons. In upstream it has been experienced urbanization, which changed land covers from natural forest or agricultural fields to residential or industrial area. Hence rate of infiltration and runoff are quite different from natural hydrological settings. In downstream, paved covers and construct of sewerage system in urbanized areas affect direct discharges and it enhances higher and faster flood peak arrival. Also tidal effect from river mouth strongly affects water levels in rivers, which must be taken into account. We develop an integrated river flood model in lower reach of urbanized areas to be able to address above described complex feature, by integrating model components: LSM coupled distributed hydrological model that models anthropogenic influence on river discharges to downstream; urban hydrological model that simulates run off response in urbanized areas; Saint Venant's equation approximated river model that integrates upstream and urban hydrological models with considering tidal effect from downstream. These features are integrated in a common modeling framework so that model interaction can be directly performed. The model is applied to the Tsurumi river basin, urbanized low-lying river basin in Yokohama and model results show that it can simulate water levels in rivers with acceptable model errors. Furthermore the model is able to install miscellaneous water planning constructs, such as runoff reduction pond in urbanized area, flood control field along the river channel, levee, etc. This can be a useful tool to investigate cost performance of hypothetical water management plan against impact of climate change in

  3. Geomorphology and flood-plain vegetation of the Sprague and lower Sycan Rivers, Klamath Basin, Oregon

    Science.gov (United States)

    O'Connor, James E.; McDowell, Patricia F.; Lind, Pollyanna; Rasmussen, Christine G.; Keith, Mackenzie K.

    2015-01-01

    This study provides information on channel and flood-plain processes and historical trends to guide effective restoration and monitoring strategies for the Sprague River Basin, a primary tributary (via the lower Williamson River) of Upper Klamath Lake, Oregon. The study area covered the lower, alluvial segments of the Sprague River system, including the lower parts of the Sycan River, North Fork Sprague River, South Fork Sprague River, and the entire main-stem Sprague River between the confluence of the North Fork Sprague and the South Fork Sprague Rivers and its confluence with the Williamson River at Chiloquin, Oregon. The study included mapping and stratigraphic analysis of flood-plain deposits and flanking features; evaluation of historical records, maps and photographs; mapping and analysis of flood-plain and channel characteristics (including morphologic and vegetation conditions); and a 2006 survey of depositional features left by high flows during the winter and spring of 2005–06.

  4. RCP8.5-Based Future Flood Hazard Analysis for the Lower Mekong River Basin

    Directory of Open Access Journals (Sweden)

    Edangodage Duminda Pradeep Perera

    2017-11-01

    Full Text Available Climatic variations caused by the excessive emission of greenhouse gases are likely to change the patterns of precipitation, runoff processes, and water storage of river basins. Various studies have been conducted based on precipitation outputs of the global scale climatic models under different emission scenarios. However, there is a limitation in regional- and local-scale hydrological analysis on extreme floods with the combined application of high-resolution atmospheric general circulation models’ (AGCM outputs and physically-based hydrological models (PBHM. This study has taken an effort to overcome that limitation in hydrological analysis. The present and future precipitation, river runoff, and inundation distributions for the Lower Mekong Basin (LMB were analyzed to understand hydrological changes in the LMB under the RCP8.5 scenario. The downstream area beyond the Kratie gauging station, located in the Cambodia and Vietnam flood plains was considered as the LMB in this study. The bias-corrected precipitation outputs of the Japan Meteorological Research Institute atmospheric general circulation model (MRI-AGCM3.2S with 20 km horizontal resolution were utilized as the precipitation inputs for basin-scale hydrological simulations. The present climate (1979–2003 was represented by the AMIP-type simulations while the future (2075–2099 climatic conditions were obtained based on the RCP8.5 greenhouse gas scenario. The entire hydrological system of the Mekong basin was modelled by the block-wise TOPMODEL (BTOP hydrological model with 20 km resolution, while the LMB area was modelled by the rainfall-runoff-inundation (RRI model with 2 km resolution, specifically to analyze floods under the aforementioned climatic conditions. The comparison of present and future river runoffs, inundation distributions and inundation volume changes were the outcomes of the study, which can be supportive information for the LMB flood management, water policy

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

    Science.gov (United States)

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

    2015-12-01

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

  6. Estimating the magnitude and frequency of floods in urban basins in Missouri

    Science.gov (United States)

    Southard, Rodney E.

    2010-01-01

    Streamgage flood-frequency analyses were done for 35 streamgages on urban streams in and adjacent to Missouri for estimation of the magnitude and frequency of floods in urban areas of Missouri. A log-Pearson Type-III distribution was fitted to the annual series of peak flow data retrieved from the U.S. Geological Survey National Water Information System. For this report, the flood frequency estimates are expressed in terms of percent annual exceedance probabilities of 50, 20, 10, 4, 2, 1, and 0.2. Of the 35 streamgages, 30 are located in Missouri. The remaining five non-Missouri streamgages were added to the dataset to improve the range and applicability of the regression analyses from the streamgage frequency analyses. Ordinary least-squares was used to determine the best set of independent variables for the regression equations. Basin characteristics selected for independent variables into the ordinary least-squares regression analyses were based on theoretical relation to flood flows, literature review of possible basin characteristics, and the ability to measure the basin characteristics using digital datasets and geographic information system technology. Results of the ordinary least-squares were evaluated on the basis of Mallow's Cp statistic, the adjusted coefficient of determination, and the statistical significance of the independent variables. The independent variables of drainage area and percent impervious area were determined to be statistically significant and readily determined from existing digital datasets. The drainage area variable was computed using the best elevation data available, either from a statewide 10-meter grid or high-resolution elevation data from urban areas. The impervious area variable was computed from the National Land Cover Dataset 2001 impervious area dataset. The National Land Cover Dataset 2001 impervious area data for each basin was compared to historical imagery and 7.5-minute topographic maps to verify the national

  7. Settling basin design in a constructed wetland using TSS removal efficiency and hydraulic retention time.

    Science.gov (United States)

    Lee, Soyoung; Maniquiz-Redillas, Marla C; Kim, Lee-Hyung

    2014-09-01

    Using total suspended solid (TSS) removal efficiency and hydraulic retention time (HRT) as design parameters a design guideline of a settling basin in a constructed wetland (CW) was suggested; as well as management of sediment and particle in the settling basin. The CW was designed to treat the piggery wastewater effluent from a wastewater treatment plant during dry days and stormwater runoff from the surrounding paved area during wet days. The first settling basin (FSB) in the CW was theoretically designed with a total storage volume (TSV) of 453m(3) and HRT of 5.5hr. The amount of sediment and particles settled at the FSB was high due to the sedimentation and interception of plants in the CW. Dredging of sediments was performed when the retention rate at the FSB decreased to approximately 80%. Findings showed that the mean flow rate was 21.8m(3)/hr less than the designed flow rate of 82.8m(3)/hr indicating that the FSB was oversize and operated with longer HRT (20.7hr) compared to the design HRT. An empirical model to estimate the length of the settling basin in the CW was developed as a function of HRT and desired TSS removal efficiency. Using the minimum tolerable TSS removal efficiency of 30%, the length of the FSB was estimated to be 31.2m with 11.8hr HRT. Copyright © 2014. Published by Elsevier B.V.

  8. Effects of stormwater infiltration on quality of groundwater beneath retention and detention basins

    Science.gov (United States)

    Fischer, D.; Charles, E.G.; Baehr, A.L.

    2003-01-01

    Infiltration of storm water through detention and retention basins may increase the risk of groundwater contamination, especially in areas where the soil is sandy and the water table shallow, and contaminants may not have a chance to degrade or sorb onto soil particles before reaching the saturated zone. Groundwater from 16 monitoring wells installed in basins in southern New Jersey was compared to the quality of shallow groundwater from 30 wells in areas of new-urban land use. Basin groundwater contained much lower levels of dissolved oxygen, which affected concentrations of major ions. Patterns of volatile organic compound and pesticide occurrence in basin groundwater reflected the land use in the drainage areas served by the basins, and differed from patterns in background samples, exhibiting a greater occurrence of petroleum hydrocarbons and certain pesticides. Dilution effects and volatilization likely decrease the concentration and detection frequency of certain compounds commonly found in background groundwater. High recharge rates in storm water basins may cause loading factors to be substantial even when constituent concentrations in infiltrating storm water are relatively low.

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

    Science.gov (United States)

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

    2014-12-01

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

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

    Science.gov (United States)

    Liu, Li; Xu, Yue-Ping

    2017-04-01

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

  11. Flood design recipes vs. reality: can predictions for ungauged basins be trusted?

    Science.gov (United States)

    Efstratiadis, A.; Koussis, A. D.; Koutsoyiannis, D.; Mamassis, N.

    2014-06-01

    Despite the great scientific and technological advances in flood hydrology, everyday engineering practices still follow simplistic approaches that are easy to formally implement in ungauged areas. In general, these "recipes" have been developed many decades ago, based on field data from typically few experimental catchments. However, many of them have been neither updated nor validated across all hydroclimatic and geomorphological conditions. This has an obvious impact on the quality and reliability of hydrological studies, and, consequently, on the safety and cost of the related flood protection works. Preliminary results, based on historical flood data from Cyprus and Greece, indicate that a substantial revision of many aspects of flood engineering procedures is required, including the regionalization formulas as well as the modelling concepts themselves. In order to provide a consistent design framework and to ensure realistic predictions of the flood risk (a key issue of the 2007/60/EU Directive) in ungauged basins, it is necessary to rethink the current engineering practices. In this vein, the collection of reliable hydrological data would be essential for re-evaluating the existing "recipes", taking into account local peculiarities, and for updating the modelling methodologies as needed.

  12. THE HYDROLOGICAL RISK IN THE MOLDOVITA RIVER BASIN AND THE NECESSARY MEASURES FOR THE ATTENUATION OF HIGH FLOOD WAVES

    OpenAIRE

    ROMANESCU ANA MARIA; ROMANESCU GHEORGHE

    2011-01-01

    The Moldoviţa river basin is situated in the northern part ofEastern Carpathians. It is a main right side tributary of Moldova river. The averagemulti-annual flow recorded in Lunguleţ and Dragoşa hydrometric stations has thevalue of 1.638 m3/s, and 5.099 m3/s, respectively. The last catastrophic floods inMoldovita river basin occurred on 26th July 2008, with the high flood wave at17:00. A maximum flow of 539 m3/s was recorded and a water level rise to 400m.The high flood was devastating, dama...

  13. Preliminary flood-duration frequency estimates using naturalized streamflow records for the Willamette River Basin, Oregon

    Science.gov (United States)

    Lind, Greg D.; Stonewall, Adam J.

    2018-02-13

    In this study, “naturalized” daily streamflow records, created by the U.S. Army Corps of Engineers and the Bureau of Reclamation, were used to compute 1-, 3-, 7-, 10-, 15-, 30-, and 60-day annual maximum streamflow durations, which are running averages of daily streamflow for the number of days in each duration. Once the annual maximum durations were computed, the floodduration frequencies could be estimated. The estimated flood-duration frequencies correspond to the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent probabilities of their occurring or being exceeded each year. For this report, the focus was on the Willamette River Basin in Oregon, which is a subbasin of the Columbia River Basin. This study is part of a larger one encompassing the entire Columbia Basin.

  14. Eliciting knowledge on soft flood-risk management strategies in the Ukrainian Tisza river basin

    Science.gov (United States)

    Haase, D.; Kuptsova, S.; Bharwani, S.; Fischer, M. E.; Downing, T. E.

    2009-04-01

    This paper focuses on a participatory knowledge elicitation process (KnETs) to explore decision-making criteria regarding ‘soft' techniques for flood risk management in the Ukrainian Tisza river basin. Communities in this region are faced with frequent floods and limited governmental budgets to cope with flood impacts. To identify the potential for soft flood protection measures as opposed to traditional technical solutions, we explored the decision-making heuristics of village council heads and the conditions under which they do or do not prepare for a flood event. Tacit knowledge, which is often unconscious and therefore difficult to describe, is complex to uncover through conventional interview techniques. To address this issue, a participatory process has been designed to reveal this knowledge without losing its connection to the context in which it is applied. That is, the KnETs process has been designed to understand context-relevant adaptive strategies and the reasons they are chosen in a natural resource management context. The process can be adapted to explore the contextual specificities of many situations ranging from flood and drought risk management to livelihood choices and the adaptation options considered in each set of circumstances. This interdisciplinary approach integrates ethnographic methods from the social sciences domain with classical computer science knowledge engineering techniques to address current bottlenecks (related to time and resource requirements) in both areas of research. This provides a participatory process, from knowledge elicitation to knowledge representation, verification and validation, providing a greater clarity of local data and thus possibly a greater understanding of social vulnerability and adaptive behaviour in flood situations.

  15. The major floods in the Amazonas river and tributaries (Western Amazon Basin) during the 1970-2012 period : a focus on the 2012 flood

    OpenAIRE

    Espinoza, J. C.; Ronchail, J.; Frappart, F.; Lavado, W.; Santini, William; Guyot, Jean-Loup

    2013-01-01

    In this work, the authors analyze the origin of the extreme floods in the Peruvian Amazonas River during the 1970-2012 period, focusing on the recent April 2012 flooding (55 400 m(3) s(-1)). Several hydrological variables, such as rainfall, terrestrial water storage, and discharge, point out that the unprecedented 2012 flood is mainly related to an early and abundant wet season over the north of the basin. Thus, the peak of the Maranon River, the northern contributor of the Amazonas, occurred...

  16. Precipitation thresholds for triggering floods in Corgo hydrographic basin (Northern Portugal)

    Science.gov (United States)

    Santos, Monica; Fragoso, Marcelo

    2016-04-01

    The precipitation is a major cause of natural hazards and is therefore related to the flood events (Borga et al., 2011; Gaál et al., 2014; Wilhelmi & Morss, 2013). The severity of a precipitation event and their potential damage is dependent on the total amount of rain but also on the intensity and duration event (Gaál et al., 2014). In this work, it was established thresholds based on critical combinations: amount / duration of flood events with daily rainfall data for Corgo hydrographic basin, in northern Portugal. In Corgo basin are recorded 31 floods events between 1865 and 2011 (Santos et al., 2015; Zêzere et al., 2014). We determined the minimum, maximum and pre-warning thresholds that define the boundaries so that an event may occur. Additionally, we applied these thresholds to different flood events occurred in the past in the study basin. The results show that the ratio between the flood events and precipitation events that occur above the minimum threshold has relatively low probability of a flood happen. These results may be related to the reduced number of floods events (only those that caused damage reported by the media and produced some type of damage). The maximum threshold is not useful for floods forecasting, since the majority of true positives are below this limit. The retrospective analysis of the thresholds defined suggests that the minimum and pre warning thresholds are well adjusted. The application of rainfall thresholds contribute to minimize possible situations of pre-crisis or immediate crisis, reducing the consequences and the resources involved in emergency response of flood events. References Borga, M., Anagnostou, E. N., Blöschl, G., & Creutin, J. D. (2011). Flash flood forecasting, warning and risk management: the HYDRATE project. Environmental Science & Policy, 14(7), 834-844. doi: 10.1016/j.envsci.2011.05.017 Gaál, L., Molnar, P., & Szolgay, J. (2014). Selection of intense rainfall events based on intensity thresholds and

  17. Towards large scale stochastic rainfall models for flood risk assessment in trans-national basins

    Science.gov (United States)

    Serinaldi, F.; Kilsby, C. G.

    2012-04-01

    While extensive research has been devoted to rainfall-runoff modelling for risk assessment in small and medium size watersheds, less attention has been paid, so far, to large scale trans-national basins, where flood events have severe societal and economic impacts with magnitudes quantified in billions of Euros. As an example, in the April 2006 flood events along the Danube basin at least 10 people lost their lives and up to 30 000 people were displaced, with overall damages estimated at more than half a billion Euros. In this context, refined analytical methods are fundamental to improve the risk assessment and, then, the design of structural and non structural measures of protection, such as hydraulic works and insurance/reinsurance policies. Since flood events are mainly driven by exceptional rainfall events, suitable characterization and modelling of space-time properties of rainfall fields is a key issue to perform a reliable flood risk analysis based on alternative precipitation scenarios to be fed in a new generation of large scale rainfall-runoff models. Ultimately, this approach should be extended to a global flood risk model. However, as the need of rainfall models able to account for and simulate spatio-temporal properties of rainfall fields over large areas is rather new, the development of new rainfall simulation frameworks is a challenging task involving that faces with the problem of overcoming the drawbacks of the existing modelling schemes (devised for smaller spatial scales), but keeping the desirable properties. In this study, we critically summarize the most widely used approaches for rainfall simulation. Focusing on stochastic approaches, we stress the importance of introducing suitable climate forcings in these simulation schemes in order to account for the physical coherence of rainfall fields over wide areas. Based on preliminary considerations, we suggest a modelling framework relying on the Generalized Additive Models for Location, Scale

  18. Heat transfer property of refrigerant-oil mixture in a flooded evaporator: The role of bubble formation and oil retention

    International Nuclear Information System (INIS)

    Koo, Kyoung-Min; Kim, Sung-Gyu; Jeong, Young-Man; Lee, Jae-Keun; Kim, Soo Hyung; Lee, Soowon; Park, Nae-Hyun; Na, Byung-Chul; Hwang, Yoon-Jae; Kim, Byung-Soon; Hwang, Joon-Hyun

    2013-01-01

    We examined the effect of oil retention on the heat transfer performance of a shell-and-tube-type evaporator which had 26 inner tubes and was filled with the refrigerant R-134a. The refrigerant was boiled on the surface of the inner tubes in the evaporator, while chilled water circulated through these tubes. An experimental apparatus was designed to measure both the pressure and temperature profiles at the inlet and outlet of the flooded evaporator. Four windows were installed for observing the operation of the flooded evaporator. A series of experiments were carried out under the following conditions: the refrigerant saturation temperature, 5 .deg. C; refrigerant inlet quality, 0.1; heat fluxes from water to the refrigerant, 5-7 kW/m 2 .. The concentration of the oil retained in the refrigerant was then varied up to approximately 10% to observe the effect on the heat transfer performance of the flooded evaporator. Increasing the oil content (i.e., increasing the concentration up to a maximum of approximately 10%) in the refrigerant R134a did not lead to any appreciable reduction in the overall heat transfer coefficient of a flooded evaporator with multiple-inner-tubes. When the oil concentration in the refrigerant was approximately 10%, the heat transfer degradation in the case of the flooded evaporator with multiple-inner-tubes was approximately 11%, which was found to be much smaller than the heat transfer degradation in the case of a flooded evaporator with a single-tube (26-49%). This observation suggested that the oil retained in the refrigerant did not significantly deteriorate the heat transfer performance of the flooded evaporator, presumably because the presence of tube bundles promoted forced convection by agitating bubbles

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

    Science.gov (United States)

    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

  20. Detection of Flooding Responses at the River Basin Scale Enhanced by Land use Change

    Science.gov (United States)

    McCormick, Brian C.; Eshleman, Keith N.; Griffith, Jeff L.; Townsend, Philip A.

    2009-01-01

    The Georges Creek watershed (area 187.5 sq km) in western Maryland (United States) has experienced land use changes (>17% of area) associated with surface mining of coal. The adjacent Savage River watershed (area 127.2 sq km) is unmined. Moments of flood frequency distributions indicated that climatic variability affected both watersheds similarly. Normalizing annual maximum flows by antecedent streamflow and causative precipitation helped identify trends in flooding response. Analysis of contemporary storm events using Next Generation Weather Radar (NEXRAD) stage III precipitation data showed that Georges Creek floods are characterized by higher peak runoff and a shorter centroid lag than Savage River floods, likely attributable to differences in current land use. Interestingly, Georges Creek produces only two thirds of the storm-flow volume as Savage River, apparently because of infiltration into abandoned deep mine workings and an associated transbasin diversion constructed circa 1900. Empirical trend analysis is thus complicated by both hydroclimatic variability and the legacy of deep mining in the basin.

  1. Risk of flooding: Activities, parameters and regional peculiarities, Case study: Varbitsa watershed basin, Bulgaria

    Directory of Open Access Journals (Sweden)

    Lubenov Todor

    2009-01-01

    Full Text Available An overview of the activities overtaken during risk of flooding situations, in one of the more often flooding region - the watershed of Varbitsa river (Southeastern part of Bulgaria - has been performed. The main cognitive parameters for risk perception and risk definition, depending on regional, social and historical factors have been examined. The existing information and instructions for mass media communication in relation to the process of interaction in a disaster situation have been discussed. In connection to determination of the risky segments in the basin and plans for announcement, the prevention communication measures have been outlined. On the basis of the Bulgarian normative legislation, the activities concerning organization of communications in a risk-of-disaster situation and mutual aid between authorities, which are part of the Integrated Help System have been indicated. It has been accented on the necessity of a more effective realization of the action plans during natural disasters and especially flooding, in order to improve the partnership between authorities and participants in the communication process during risk-of-flooding situations.

  2. Model simulations of potential contribution of the proposed Huangpu Gate to flood control in the Lake Taihu basin of China

    Science.gov (United States)

    Zhang, Hanghui; Liu, Shuguang; Ye, Jianchun; Yeh, Pat J.-F.

    2017-10-01

    The Lake Taihu basin (36 895 km2), one of the most developed regions in China located in the hinterland of the Yangtze River Delta, has experienced increasing flood risk. The largest flood in history occurred in 1999 with a return period estimate of 200 years, considerably larger than the current capacity of the flood defense with a design return period of 50 years. Due to its flat saucer-like terrain, the capacity of the flood control system in this basin depends on flood control infrastructures and peripheral tidal conditions. The Huangpu River, an important river of the basin connecting Lake Taihu upstream and Yangtze River estuaries downstream, drains two-fifths of the entire basin. Since the water level in the Huangpu River is significantly affected by the high tide conditions in estuaries, constructing an estuary gate is considered an effective solution for flood mitigation. The main objective of this paper is to assess the potential contributions of the proposed Huangpu Gate to the flood control capacity of the basin. To achieve this goal, five different scenarios of flooding conditions and the associated gate operations are considered by using numerical model simulations. Results of quantitative analyses show that the Huangpu Gate is effective for evacuating floodwaters. It can help to reduce both peak values and duration of high water levels in Lake Taihu to benefit surrounding areas along the Taipu Canal and the Huangpu River. The contribution of the gate to the flood control capacity is closely associated with its operation modes and duration. For the maximum potential contribution of the gate, the net outflow at the proposed site is increased by 52 %. The daily peak level is decreased by a maximum of 0.12 m in Lake Taihu, by maxima of 0.26-0.37 and 0.46-0.60 m in the Taipu Canal and the Huangpu River, respectively, and by 0.05-0.39 m in the surrounding areas depending on the local topography. It is concluded that the proposed Huangpu Gate can reduce

  3. Floods

    Science.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    C. H. R. Lima

    2017-12-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  6. Long-term Simulation of the Removal of Pollutants in Retention Basins

    DEFF Research Database (Denmark)

    Larsen, Torben; Neerup-Jensen, Ole; Kaasgaard, Mogens

    2005-01-01

    -dependant sedimentation and the variation of the settling velocity of the particles. The results show that including these effects lead to significant lower discharges of pollutants compared to conventional methods of estimation. As an example computations with a spectrum of basins which cover realistic sizes show......The paper describes a method for the long-term simulation of the discharge of pollutants to the environment from storm sewer overflows in combined sewer systems, which has a connected retention basin. This study covers Cd, Cu, Ni, Pb, Zn and PAH. The method includes both the influence of the flow...... that the long-term discharges of PAH are about half of the expected values without removal. $CPY EWA 2005....

  7. Impact of storm water on groundwater quality below retention/detention basins.

    Science.gov (United States)

    Zubair, Arif; Hussain, Asif; Farooq, Mohammed A; Abbasi, Haq Nawaz

    2010-03-01

    Groundwater from 33 monitoring of peripheral wells of Karachi, Pakistan were evaluated in terms of pre- and post-monsoon seasons to find out the impact of storm water infiltration, as storm water infiltration by retention basin receives urban runoff water from the nearby areas. This may increase the risk of groundwater contamination for heavy metals, where the soil is sandy and water table is shallow. Concentration of dissolved oxygen is significantly low in groundwater beneath detention basin during pre-monsoon season, which effected the concentration of zinc and iron. The models of trace metals shown in basin groundwater reflect the land use served by the basins, while it differed from background concentration as storm water releases high concentration of certain trace metals such as copper and cadmium. Recharge by storm water infiltration decreases the concentration and detection frequency of iron, lead, and zinc in background groundwater; however, the study does not point a considerable risk for groundwater contamination due to storm water infiltration.

  8. Building the ensemble flood prediction system by using numerical weather prediction data: Case study in Kinu river basin, Japan

    Science.gov (United States)

    Ishitsuka, Y.; Yoshimura, K.

    2016-12-01

    Floods have a potential to be a major source of economic or human damage caused by natural disasters. Flood prediction systems were developed all over the world and to treat the uncertainty of the prediction ensemble simulation is commonly adopted. In this study, ensemble flood prediction system using global scale land surface and hydrodynamic model was developed. The system requests surface atmospheric forcing and Land Surface Model, MATSIRO, calculates runoff. Those generated runoff is inputted to hydrodynamic model CaMa-Flood to calculate discharge and flood inundation. CaMa-Flood can simulate flood area and its fraction by introducing floodplain connected to river channel. Forecast leadtime was set 39hours according to forcing data. For the case study, the flood occurred at Kinu river basin, Japan in 2015 was hindcasted. In a 1761 km² Kinu river basin, 3-days accumulated average rainfall was 384mm and over 4000 people was left in the inundated area. Available ensemble numerical weather prediction data at that time was inputted to the system in a resolution of 0.05 degrees and 1hour time step. As a result, the system predicted the flood occurrence by 45% and 84% at 23 and 11 hours before the water level exceeded the evacuation threshold, respectively. Those prediction lead time may provide the chance for early preparation for the floods such as levee reinforcement or evacuation. Adding to the discharge, flood area predictability was also analyzed. Although those models were applied for Japan region, this system can be applied easily to other region or even global scale. The areal flood prediction in meso to global scale would be useful for detecting hot zones or vulnerable areas over each region.

  9. Mapping Flooded Rice Paddies Using Time Series of MODIS Imagery in the Krishna River Basin, India

    Directory of Open Access Journals (Sweden)

    Pardhasaradhi Teluguntla

    2015-07-01

    Full Text Available Rice is one of the major crops cultivated predominantly in flooded paddies, thus a large amount of water is consumed during its growing season. Accurate paddy rice maps are therefore important inputs for improved estimates of actual evapotranspiration in the agricultural landscape. The main objective of this study was to obtain flooded paddy rice maps using multi-temporal images of Moderate Resolution Imaging Spectroradiometer (MODIS in the Krishna River Basin, India. First, ground-based spectral samples collected by a field spectroradiometer, CROPSCAN, were used to demonstrate unique contrasts between the Normalized Difference Vegetation Index (NDVI and the Land Surface Water Index (LSWI observed during the transplanting season of rice. The contrast between Enhanced Vegetation Index (EVI and Land Surface Water Index (LSWI from MODIS time series data was then used to generate classification decision rules to map flooded rice paddies, for the transplanting seasons of Kharif and Rabi rice crops in the Krishna River Basin. Consistent with ground spectral observations, the relationship of the MODIS EVI vs. LSWI of paddy rice fields showed distinct features from other crops during the transplanting seasons. The MODIS-derived maps were validated against extensive reference data collected from multiple land use field surveys. The accuracy of the paddy rice maps, when determined using field plot data, was approximately 78%. The MODIS-derived rice crop areas were also compared with the areas reported by Department of Agriculture (DOA, Government of India (Government Statistics. The estimated root mean square difference (RMSD of rice area estimated using MODIS and those reported by the Department of Agriculture over 10 districts varied between 3.4% and 6.6% during 10 years of our study period. Some of the major factors responsible for this difference include high noise of the MODIS images during the prolonged monsoon seasons (typically June–October and

  10. Flash flood warnings for ungauged basins based on high-resolution precipitation forecasts

    Science.gov (United States)

    Demargne, Julie; Javelle, Pierre; Organde, Didier; de Saint Aubin, Céline; Janet, Bruno

    2016-04-01

    Early detection of flash floods, which are typically triggered by severe rainfall events, is still challenging due to large meteorological and hydrologic uncertainties at the spatial and temporal scales of interest. Also the rapid rising of waters necessarily limits the lead time of warnings to alert communities and activate effective emergency procedures. To better anticipate such events and mitigate their impacts, the French national service in charge of flood forecasting (SCHAPI) is implementing a national flash flood warning system for small-to-medium (up to 1000 km²) ungauged basins based on a discharge-threshold flood warning method called AIGA (Javelle et al. 2014). The current deterministic AIGA system has been run in real-time in the South of France since 2005 and has been tested in the RHYTMME project (rhytmme.irstea.fr/). It ingests the operational radar-gauge QPE grids from Météo-France to run a simplified hourly distributed hydrologic model at a 1-km² resolution every 15 minutes. This produces real-time peak discharge estimates along the river network, which are subsequently compared to regionalized flood frequency estimates to provide warnings according to the AIGA-estimated return period of the ongoing event. The calibration and regionalization of the hydrologic model has been recently enhanced for implementing the national flash flood warning system for the entire French territory by 2016. To further extend the effective warning lead time, the flash flood warning system is being enhanced to ingest Météo-France's AROME-NWC high-resolution precipitation nowcasts. The AROME-NWC system combines the most recent available observations with forecasts from the nowcasting version of the AROME convection-permitting model (Auger et al. 2015). AROME-NWC pre-operational deterministic precipitation forecasts, produced every hour at a 2.5-km resolution for a 6-hr forecast horizon, were provided for 3 significant rain events in September and November 2014 and

  11. STUDY REGARDING DELINEATION OF FLOOD HAZARD ZONES IN THE HYDROGRAPHIC BASIN OF THE SOMEŞ RIVER, BORDER AREA

    Directory of Open Access Journals (Sweden)

    STOICA F.

    2014-03-01

    Full Text Available The hydrological studies will provide the characteristic parameters for the floods occurred for the calculus discharges with overflow probabilities of 0,1%; 1%, 5%, 10%. The hydrologic and hydraulic models will be made by using the hydro-meteorological data base and the topographical measurements on site; them calibration will be done according to the records of the historical floods. The studies on the hydrologic and hydraulic models will be necessary for the establishment of the carrying capacity of the riverbeds, for the delimitation of the flood plains and for the detection of the transit discharges at the hydro-technical installations, but also for the establishment of the parameters needed for the structural measures’ projects. These will be based on the 1D and 2D unstable hydro-dynamic models. Therefore, the users would be able to assess the proposed measures and the impact over the river’s system; of course with the potential combination of the 1D and 2D. The main objectives followed by the project are: • identification of the river basins or river sub-basins with flood risks; • regionalization of the flood hazard; • presentation of the main flash floods occurred during the last 30 years, which induced floods; • assessment of the consequences of eventual flood over the population, properties and environment; • the establishment of the protection degree, accepted for the human settlements, for the economic and social objectives, for the farm areas, etc.;

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

    Science.gov (United States)

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

    2016-07-01

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

  13. Relationship of Rainfall Distribution and Water Level on Major Flood 2014 in Pahang River Basin, Malaysia

    Directory of Open Access Journals (Sweden)

    Nur Hishaam Sulaiman

    2017-01-01

    Full Text Available Climate change gives impact on extreme hydrological events especially in extreme rainfall. This article discusses about the relationship of rainfall distribution and water level on major flood 2014 in Pahang River Basin, Malaysia in helping decision makers to flood management system. Based on DID Malaysia rainfall station, 56 stations have being use as point in this research and it is including Pahang, Terengganu, Kelantan and Perak. Data set for this study were analysed with GIS analysis using interpolation method to develop Isohyet map and XLstat statistical software for PCA and SPC analyses. The results that were obtained from the Isohyet Map for three months was mid-November, rainfall started to increase about in range of 800mm-1200mm and the intensity keep increased to 2200mm at mid-December 2014. The high rainfall intensity sense at highland that is upstream of Pahang River. The PCA and SPC analysis also indicates the high relationship between rainfall and water level of few places at Pahang River. The Sg. Yap station and Kg. Serambi station obtained the high relationship of rainfall and water level with factor loading value at 0.9330 and 0.9051 for each station. Hydrological pattern and trend are extremely affected by climate such as north east monsoon season that occurred in South China Sea and affected Pahang during November to March. The findings of this study are important to local authorities by providing basic data as guidelines to the integrated river management at Pahang River Basin.

  14. Coupled prediction of flash flood response and debris flow occurrence in an alpine basin

    Science.gov (United States)

    Amponsah, William

    2015-04-01

    Coupled prediction of flash flood response and debris flow occurrence in an alpine basin Author(s): William Amponsah1, E.I. Nikolopoulos2, Lorenzo Marchi1, Roberto Dinale4, Francesco Marra3,Davide Zoccatelli2 , Marco Borga2 Affiliation(s): 1CNR - IRPI, Corso Stati Uniti 4, 35127, Padova, ITALY, 2Department of Land, Environment, Agriculture and Forestry, University of Padova,VialeDell'Università 16, 35020, Legnaro PD, ITALY 3Department of Geography, Hebrew University of Jerusalem, ISRAEL 4Ufficio Idrografico, Provincia Autonoma di Bolzano, Bolzano, Italy This contribution examines the main hydrologic and morphologic metrics responsible for widespread triggering of debris-flows associated with flash flood occurrences in headwater alpine catchments.To achieve this objective, we investigate the precipitation forcing, hydrologic responses and landslides and debris-flow occurrences that prevailed during the August 4-5, 2012 extreme flash flood on the 140 km2 Vizze basin in the Eastern Alps of Italy. An intensive post-event survey was carried out a few days after the flood. This included the surveys of cross-sectional geometry and flood marks for the estimation of the peak discharges at multiple river sections and of the initiation and deposition areas of several debris flows. Rainfall estimates are based on careful analysis of weather radar observations and raingauge data. These data and observations permitted the implementation and calibration of a spatially distributed hydrological model, which was used to derive simulated flood hydrographs in 58 tributaries of the Vizze basin. Of these, 33 generated debris-flows, with area ranging from 0.02 km2 to 10 km2, with an average of 1.5 km2. With 130 mm peak event rainfall and a duration of 4 hours (with a max intensity of 90 mm h-1 for 10 min), model-simulated unit peak discharges range from 4 m3 s-1 km-2for elementary catchments up to 10 km2 to 2 m3 s-1 km-2 for catchments in the range of 50 - 100 km2. These are very high

  15. Stationarity of annual flood peaks during 1951-2010 in the Pearl River basin, China

    Science.gov (United States)

    Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Xiao, Mingzhong; Xu, Chong-Yu

    2014-11-01

    The assumption of stationarity of annual peak flood (APF) records at 28 hydrological stations across the Pearl River basin, China, is tested. Abrupt changes in mean and variance are tested using the Pettitt technique and the Loess method. Trends of APFs are analyzed using the Mann-Kendall method and the Spearman technique. And then the stationarity of the APF series is further investigated by GAMLSS models and long-term persistence. Results indicate that: (1) abrupt changes in mean and variance have similar influences on the changing properties of APFs, such as stationarity. Abrupt changes in mean and variance are only field significant in the East River basin; (2) the change points have a considerable impact on the detection of trends, and these may be attributed to the fact that a abrupt increase or decrease in mean values will affect the trend variations. Besides, for the APF series being free of change points and trend, the GAMLSS models also corroborate stationarity of the APF series; (3) the nonstationarity in the Pearl River basin is mainly due to the existence of the change point. However, the APF series with change points in mean and/or variance are also characterized by long-term persistence, and thus it is infeasible to assert that the abrupt behaviors and/or trends of the APF series are the result of human activities or long-term persistence, especially in the East River basin. Results of this study will provide information for management of water resources and design of hydraulic facilities in the Pearl River basin in a changing environment.

  16. Spatial moments of catchment rainfall: rainfall spatial organisation, basin morphology, and flood response

    Directory of Open Access Journals (Sweden)

    D. Zoccatelli

    2011-12-01

    Full Text Available This paper describes a set of spatial rainfall statistics (termed "spatial moments of catchment rainfall" quantifying the dependence existing between spatial rainfall organisation, basin morphology and runoff response. These statistics describe the spatial rainfall organisation in terms of concentration and dispersion statistics as a function of the distance measured along the flow routing coordinate. The introduction of these statistics permits derivation of a simple relationship for the quantification of catchment-scale storm velocity. The concept of the catchment-scale storm velocity takes into account the role of relative catchment orientation and morphology with respect to storm motion and kinematics. The paper illustrates the derivation of the statistics from an analytical framework recently proposed in literature and explains the conceptual meaning of the statistics by applying them to five extreme flash floods occurred in various European regions in the period 2002–2007. High resolution radar rainfall fields and a distributed hydrologic model are employed to examine how effective are these statistics in describing the degree of spatial rainfall organisation which is important for runoff modelling. This is obtained by quantifying the effects of neglecting the spatial rainfall variability on flood modelling, with a focus on runoff timing. The size of the study catchments ranges between 36 to 982 km2. The analysis reported here shows that the spatial moments of catchment rainfall can be effectively employed to isolate and describe the features of rainfall spatial organization which have significant impact on runoff simulation. These statistics provide useful information on what space-time scales rainfall has to be monitored, given certain catchment and flood characteristics, and what are the effects of space-time aggregation on flood response modeling.

  17. Examination of flood characteristics at selected streamgages in the Meramec River Basin, eastern Missouri, December 2015–January 2016

    Science.gov (United States)

    Holmes, Robert R.; Koenig, Todd A.; Rydlund, Jr., Paul H.; Heimann, David C.

    2016-09-13

    OverviewHeavy rainfall resulted in major flooding in the Meramec River Basin in eastern Missouri during late December 2015 through early January 2016. Cumulative rainfall from December 14 to 29, 2015, ranged from 7.6 to 12.3 inches at selected precipitation stations in the basin with flooding driven by the heaviest precipitation (3.9–9.7 inches) between December 27 and 29, 2015. Financial losses from flooding included damage to homes and other structures, damage to roads, and debris removal. Eight of 11 counties in the basin were declared a Federal Disaster Area.The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers and St. Louis Metropolitan Sewer District, operates multiple streamgages along the Meramec River and its primary tributaries including the Bourbeuse River and Big River. The period of record for streamflow at streamgages in the basin included in this report ranges from 24 to 102 years. Instrumentation in a streamgage shelter automatically makes observations of stage using a variety of methods (submersible pressure transducer, non-submersible pressure transducer, or non-contact radar). These observations are recorded autonomously at a predetermined programmed frequency (typically either 15 or 30 minutes) dependent on drainage-area size and concomitant flashiness of the stream. Although stage data are important, streamflow data are equally or more important for streamflow forecasting, water-quality constituent loads computation, flood-frequency analysis, and flood mitigation planning. Streamflows are computed from recorded stage data using an empirically determined relation between stage and streamflow termed a “rating.” Development and verification of the rating requires periodic onsite discrete measurements of streamflow throughout time and over the range of stages to define local hydraulic conditions.The purpose of this report is to examine characteristics of flooding that occurred in the Meramec River Basin in

  18. Integrated flood damage modelling in the Ebro river basin under hydrodynamic, socio-economic and environmental factors

    Science.gov (United States)

    Foudi, S.; Galarraga, I.; Osés, N.

    2012-04-01

    This paper presents a model of flood damage measurement. It studies the socio-economic and environmental potential damage of floods in the Ebro river basin. We estimate the damage to the urban, rural and environmental sectors. In these sectors, we make distinctions between residential, non residential, cultural, agricultural, public facilities and utilities, environmental and human subsectors. We focus on both the direct, indirect, tangible and intangible impacts. The residential damages refer to the damages on housing, costs of repair and cleaning as direct effects and the re-housing costs as an indirect effect. The non residential and agricultural impacts concern the losses to the economic sectors (industry, business, agricultural): production, capital losses, costs of cleaning and repairs for the direct costs and the consequences of the suspension of activities for the indirect costs. For the human sector, we refer to the physical impacts (injuries and death) in the direct tangible effects and to the posttraumatic stress as indirect intangible impact. The environmental impacts focus on a site of Community Interests (pSCIs) in the case study area. The case study is located the Ebro river basin, Spain. The Ebro river basin is the larger river basin in term of surface and water discharge. The Ebro river system is subject to Atlantic and Mediterranean climatic influences. It gathers most of its water from the north of Spain (in the Pyrenees Mountains) and is the most important river basin of Spain in term of water resources. Most of the flooding occurs during the winter period. Between 1900- 2010, the National Catalogue of Historical Floods identifies 372 events: meanly 33 events every 10 years and up to 58 during the 1990-2000. Natural floods have two origins: (i) persistent rainfalls in large sub basins raised up by high temperature giving rise to a rapid thaw in the Pyrenees, (ii) local rainfalls of short duration and high intensity that gives rise to rapid and

  19. Assessment of Remote Sensing Products and Hydrologic Simulation of the 2016 Louisiana Flood in the Amite River Basin

    Science.gov (United States)

    Gao, S.; Bilskie, M. V.; Hagen, S. C.; Braud, D.

    2017-12-01

    Riverine and coastal flooding are one of the most common environmental hazards that affect millions of people around the world. For example, in August 2016, a slow-moving upper level low-pressure system with a high amount of atmospheric moisture brought heavy rains from August 11 to August 13. The torrential downpours led to widespread flash flooding and river flooding across multiple parishes in Southeast Louisiana and Southwest Mississippi (NWS, 2016; Watson et al., 2017). Precipitation totals as high as 26 inches were recorded during the two-day event. A Louisiana Economic Development report documented that the state of Louisiana suffered more than eight billion dollars in damage from the catastrophic flooding (LED, 2016). According to the National Weather Service (NWS) in New Orleans, the rainfall caused the Amite River, Comite River, Tangipahoa River and Tickfaw River to rise to record-setting levels. Some of the most serious flooding occurred along the Amite River, which runs between Baton Rouge and the nearby city of Denham Springs, and has its headwaters in southwestern Mississippi and drains into Lake Maurepas (Mossa et al., 1997). To develop an understanding of the driving mechanisms that caused the catastrophic flooding a campaign was initiated to collect and rigorously examine all possible remote sensing products in order to derive the flooding extent and depth within the Amite River basin. In addition, a Soil and Water Assessment Tool (SWAT) has been developed for the Amite River watershed to simulate runoff from the 2016 Louisiana flood event. The developed and assimilated remote sensing and modeling products will enhance understanding of the hydrological processes within the Amite River basin. This will provide further insight into conceptualization of flood risk across river deltas that are vulnerable to both riverine and coastal flooding. Reference:LED. (2016). The economic impact of the august 2016 floods on the state of Louisiana. Mossa, J., & Mc

  20. Integrated risk assessment for the natomas basin (California) analysis of loss of life and emergency management for floods

    NARCIS (Netherlands)

    Jonkman, S.N.; Hiel, L.A.; Bea, R.G.; Foster, H.; Tsioulou, A.; Arroyo, P.; Stallard, T.; Harris, L.

    2012-01-01

    This article assesses the risk to life for the Natomas Basin, a low-lying, rapidly urbanizing region in the Sacramento-San Joaquin Delta in California. Using an empirical method, the loss of life is determined for a flood (high water), seismic, and sunny-day levee breach scenario. The analysis

  1. Flood of August 11–16, 2010, in the South Skunk River Basin, central and southeast Iowa

    Science.gov (United States)

    Barnes, Kimberlee K.; Eash, David A.

    2012-01-01

    Severe thunderstorm activity during August 8–11, 2010 in central and southeast Iowa resulted in major flooding from August 11–16, 2010, in the South Skunk River Basin. Rain gages at Ames and Story City recorded 96-hour rainfall amounts of 9.61 and 8.70 inches, respectively. The majority of the rainfall occurred during a 52-hour period, beginning late at night on August 8. Within the South Skunk River Basin, peak discharges of 14,800 cubic feet per second (annual flood-probability estimate of 0.2 to 1 percent) at the 05470000 South Skunk River near Ames, Iowa streamgage; of 36,200 cubic feet per second (annual flood-probability estimate of less than 0.2 percent) at the 05471000 South Skunk River below Squaw Creek near Ames, Iowa streamgage (both on August 11, 2010); and of 24,000 cubic feet per second (annual flood-probability estimate of 0.2 to 1 percent) at 05471050 South Skunk River at Colfax, Iowa streamgage on August 14 are the largest floods on record for these sites. Peak discharges at 05470500 Squaw Creek at Ames, Iowa streamgage of 22,400 cubic feet per second (annual flood-probability estimate of less than 0.2 percent) on August 11; and at 05471500 South Skunk River near Oskaloosa, Iowa streamgage, of 25,200 cubic feet per second (annual flood- probability estimate of 1 to 2 percent) on August 16 are the second highest floods on record. This report provides a description of the watershed, the thunderstorms, the flooding, and a profile of high-water marks measured at 20 locations along the South Skunk River between County Road V67/280th Avenue, northeast of Ollie in Keokuk County and West Riverside Road in Ames, a distance of 128 river miles.

  2. THE HYDROLOGICAL RISK IN THE MOLDOVITA RIVER BASIN AND THE NECESSARY MEASURES FOR THE ATTENUATION OF HIGH FLOOD WAVES

    Directory of Open Access Journals (Sweden)

    ROMANESCU ANA MARIA

    2011-03-01

    Full Text Available The Moldoviţa river basin is situated in the northern part ofEastern Carpathians. It is a main right side tributary of Moldova river. The averagemulti-annual flow recorded in Lunguleţ and Dragoşa hydrometric stations has thevalue of 1.638 m3/s, and 5.099 m3/s, respectively. The last catastrophic floods inMoldovita river basin occurred on 26th July 2008, with the high flood wave at17:00. A maximum flow of 539 m3/s was recorded and a water level rise to 400m.The high flood was devastating, damaging many houses and householdattachments, social and economic buildings. Over 20 ha of agricultural land wereaffected in Vatra Moldoviţei. The waters flooded over 7 households in ValeaStânei village and in Ciumârna, four gabions on the left river bank and 2 littlebridges were destroyed. In Vatra Moldoviţei village, 180 m of dam as well as afootbridge were destroyed, and a wood deposit was flooded. In Paltinu village, thecommune road was 70% damaged, two bridges were severely affected, and thebridge defence collapsed over a distance of 50 m. As a result of the anthropicalintervention, the catastrophic floods are more and more frequent.

  3. Flooding

    Science.gov (United States)

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

  4. Bayesian uncertainty assessment of flood predictions in ungauged urban basins for conceptual rainfall-runoff models

    Directory of Open Access Journals (Sweden)

    A. E. Sikorska

    2012-04-01

    Full Text Available Urbanization and the resulting land-use change strongly affect the water cycle and runoff-processes in watersheds. Unfortunately, small urban watersheds, which are most affected by urban sprawl, are mostly ungauged. This makes it intrinsically difficult to assess the consequences of urbanization. Most of all, it is unclear how to reliably assess the predictive uncertainty given the structural deficits of the applied models. In this study, we therefore investigate the uncertainty of flood predictions in ungauged urban basins from structurally uncertain rainfall-runoff models. To this end, we suggest a procedure to explicitly account for input uncertainty and model structure deficits using Bayesian statistics with a continuous-time autoregressive error model. In addition, we propose a concise procedure to derive prior parameter distributions from base data and successfully apply the methodology to an urban catchment in Warsaw, Poland. Based on our results, we are able to demonstrate that the autoregressive error model greatly helps to meet the statistical assumptions and to compute reliable prediction intervals. In our study, we found that predicted peak flows were up to 7 times higher than observations. This was reduced to 5 times with Bayesian updating, using only few discharge measurements. In addition, our analysis suggests that imprecise rainfall information and model structure deficits contribute mostly to the total prediction uncertainty. In the future, flood predictions in ungauged basins will become more important due to ongoing urbanization as well as anthropogenic and climatic changes. Thus, providing reliable measures of uncertainty is crucial to support decision making.

  5. Modeling Flood Inundation Induced by River Flow and Storm Surges over a River Basin

    Directory of Open Access Journals (Sweden)

    Wei-Bo Chen

    2014-10-01

    Full Text Available Low-lying coastal regions and their populations are at risk during storm surge events and high freshwater discharges from upriver. An integrated storm surge and flood inundation modeling system was used to simulate storm surge and inundation in the Tsengwen River basin and the adjacent coastal area in southern Taiwan. A three-dimensional hydrodynamic model with an unstructured grid was used, which was driven by the tidal elevation at the open boundaries and freshwater discharge at the upriver boundary. The model was validated against the observed water levels for three typhoon events. The simulation results for the model were in reasonable agreement with the observational data. The model was then applied to investigate the effects of a storm surge, freshwater discharge, and a storm surge combined with freshwater discharge during an extreme typhoon event. The super Typhoon Haiyan (2013 was artificially shifted to hit Taiwan: the modeling results showed that the inundation area and depth would cause severe overbank flow and coastal flooding for a 200 year return period flow. A high-resolution grid model is essential for the accurate simulation of storm surges and inundation.

  6. Prescriptions for adaptive comanagement: the case of flood management in the German Rhine basin

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    Gert Becker

    2015-09-01

    Full Text Available Centrally administered bureaucracies are ill suited to managing the environmental resources of complex social-ecological systems. Therefore management approaches are required that can better deal with its complexity and uncertainty, which are further exacerbated by developments such as climate change. Adaptive comanagement (ACM has emerged as a relatively novel governance approach and potential solution to the challenges arising. Adaptive comanagement hinges on certain institutional prescriptions intended to enhance the adaptability of management by improving the comprehension of and response to the complex context and surprises of social-ecological systems. The ACM literature describes that for enhanced adaptability, institutional arrangements should be polycentric, aligned with the scale of ecosystems (the bioregional approach, feature open and participatory governance, and involve much experimentation. The case of flood management in the German part of the Rhine basin is used to provide an assessment of these ideas. We analyze whether and to what degree the prescriptions have been implemented and whether or not certain fundamental changes seen in German flood management can be traced back to the application of the prescriptions. Our study demonstrates a transition from the traditional engineering and "flood control" approach to a more holistic management concept based on a risk perspective. In this process, the four ACM prescriptions have made an important contribution in preparing or facilitating policy changes. The findings suggest that the application of the prescriptions requires the right supporting context before they can be applied to the fullest extent possible, such as a high problem pressure, new discourses, or leading actors. A major constraint arises in the misalignment of political power and of the different interests of the actors, which contribute to reactive management and inadequate interplay. To address this, we recommend

  7. Floods of July 23-26, 2010, in the Little Maquoketa River and Maquoketa River Basins, Northeast Iowa

    Science.gov (United States)

    Eash, David A.

    2012-01-01

    Minor flooding occurred July 23, 2010, in the Little Maquoketa River Basin and major flooding occurred July 23–26, 2010, in the Maquoketa River Basin in northeast Iowa following severe thunderstorm activity over the region during July 22–24. A breach of the Lake Delhi Dam on July 24 aggravated flooding on the Maquoketa River. Rain gages at Manchester and Strawberry Point, Iowa, recorded 72-hour-rainfall amounts of 7.33 and 12.23 inches, respectively, on July 24. The majority of the rainfall occurred during a 48-hour period. Within the Little Maquoketa River Basin, a peak-discharge estimate of 19,000 cubic feet per second (annual flood-probability estimate of 4 to 10 percent) at the discontinued 05414500 Little Maquoketa River near Durango, Iowa streamgage on July 23 is the sixth largest flood on record. Within the Maquoketa River Basin, peak discharges of 26,600 cubic feet per second (annual flood-probability estimate of 0.2 to 1 percent) at the 05416900 Maquoketa River at Manchester, Iowa streamgage on July 24, and of 25,000 cubic feet per second (annual flood-probability estimate of 1 to 2 percent) at the 05418400 North Fork Maquoketa River near Fulton, Iowa streamgage on July 24 are the largest floods on record for these sites. A peak discharge affected by the Lake Delhi Dam breach on July 24 at the 05418500 Maquoketa River near Maquoketa, Iowa streamgage, located downstream of Lake Delhi, of 46,000 cubic feet per second on July 26 is the third highest on record. High-water marks were measured at five locations along the Little Maquoketa and North Fork Little Maquoketa Rivers between U.S. Highway 52 near Dubuque and County Road Y21 near Rickardsville, a distance of 19 river miles. Highwater marks were measured at 28 locations along the Maquoketa River between U.S. Highway 52 near Green Island and State Highway 187 near Arlington, a distance of 142 river miles. High-water marks were measured at 13 locations along the North Fork Maquoketa River between

  8. Assessing the exposure to floods to estimate the risk of flood-related damage in French Mediterranean basins

    Directory of Open Access Journals (Sweden)

    Saint-Martin Clotilde

    2016-01-01

    Full Text Available The dreadful floods of 1999, 2002 and 2003 in South of France have alerted public opinion on the need for a more efficient and a further generalized national flood-forecasting system. This is why in 2003 Irstea and Meteo-France have implemented a new warning method for flash floods, including on small watersheds, using radar rainfall data in real-time: the AIGA method. This modelling method currently provides real-time information on the magnitude of floods, but doesn’t take into account the elements at risk surrounding the river streams. Its benefit for crisis management is therefore limited as it doesn’t give information on the actual flood risk. To improve the relevance of the AIGA method, this paper shows the benefits of the combination of hydrological warnings with an exposure index, to be able to assess the risk of flood-related damage in real time. To complete this aim, this work presents an innovative and easily reproducible method to evaluate exposure to floods over large areas with simple land-use data. For validation purpose, a damage database has been implemented to test the relevance of both AIGA warnings and exposure levels. A case study on the floods of the 3rd October 2015 is presented to test the effectiveness of the combination of hazard and exposure to assess the risk of flood-related damage. This combination seems to give an accurate overview of the streams at risk, where the most important amount of damage has been observed after the flood.

  9. Reconstructing the Santa Tecla flash flood in the Ondara River (Ebro Basin, NE Spain)

    Science.gov (United States)

    Balasch, J. C.; Tuset, J.; Ramos, M. C.; Martínez-Casasnovas, J. A.

    2009-09-01

    The Santa Tecla flood may be considered the most catastrophic rainfall event in the modern history of Catalonia (NE Iberian Peninsula), and one of the most important in the Western Mediterranean Basin. This event took place during the night between 22nd and 23rd September 1874, in which torrential convective rainfalls generated significant flash floods in most of the small streams in the southern half of Catalonia (i.e. Ondara, Corb, Francolí and Siurana catchments). More than 570 people died, 150 of which in the town of Tàrrega, by the Ondara River. Despite being one of the last huge floods of the pre-instrumental era and, consequently, without any precipitation or flow data, the event was reconstructed both hydraulically and hydrologically for the Ondara River at Tàrrega (150 km2). Thus, the maximum water level and the temporal evolution of the flood were obtained, respectively, from several epigraphic limnimarks found in Tàrrega and from the event description recorded in historical documents. Additionally, the information from local archaeological sites allowed the reconstruction of the fluvial section at Tàrrega at the end of the 19th century. Finally, some old cellars flooded during the event provided information about sediment concentration at the peak flow. The methodology put into practice for the event reconstruction had two stages. The first stage was the hydraulic modelling, which estimated the peak flow. The input data used were the maximum water level given by the limnimetric marks, a digital terrain model of the river bed shape, and the stream and floodplain roughness and channel slope (which were considered similar to the present ones, according to archaeological data). The hydraulic model used was the unidimensional HEC-RAS (USACE), applied in several cross sections of the Ondara River at Tàrrega. The second stage was the hydrological modelling. The objective of this stage was to derive the event hyetograph from the above calculated peak flow

  10. A large-scale simulation of climate change effects on flood regime - A case study for the Alabama-Coosa-Tallapoosa River Basin

    Science.gov (United States)

    Dullo, T. T.; Gangrade, S.; Marshall, R.; Islam, S. R.; Ghafoor, S. K.; Kao, S. C.; Kalyanapu, A. J.

    2017-12-01

    The damage and cost of flooding are continuously increasing due to climate change and variability, which compels the development and advance of global flood hazard models. However, due to computational expensiveness, evaluation of large-scale and high-resolution flood regime remains a challenge. The objective of this research is to use a coupled modeling framework that consists of a dynamically downscaled suite of eleven Coupled Model Intercomparison Project Phase 5 (CMIP5) climate models, a distributed hydrologic model called DHSVM, and a computational-efficient 2-dimensional hydraulic model called Flood2D-GPU to study the impacts of climate change on flood regime in the Alabama-Coosa-Tallapoosa (ACT) River Basin. Downscaled meteorologic forcings for 40 years in the historical period (1966-2005) and 40 years in the future period (2011-2050) were used as inputs to drive the calibrated DHSVM to generate annual maximum flood hydrographs. These flood hydrographs along with 30-m resolution digital elevation and estimated surface roughness were then used by Flood2D-GPU to estimate high-resolution flood depth, velocities, duration, and regime. Preliminary results for the Conasauga river basin (an upper subbasin within ACT) indicate that seven of the eleven climate projections show an average increase of 25 km2 in flooded area (between historic and future projections). Future work will focus on illustrating the effects of climate change on flood duration and area for the entire ACT basin.

  11. Sensitivity Analysis of the Surface Runoff Coefficient of HiPIMS in Simulating Flood Processes in a Large Basin

    Directory of Open Access Journals (Sweden)

    Yueling Wang

    2018-03-01

    Full Text Available To simulate flood processes at the basin level, the GPU-based High-Performance Integrated Hydrodynamic Modelling System (HiPIMS is gaining interest as computational capability increases. However, the difficulty of coping with rainfall input to HiPIMS reduces the possibility of acquiring a satisfactory simulation accuracy. The objective of this study is to test the sensitivity of the surface runoff coefficient in the HiPIMS source term in the Misai basin with an area of 797 km2 in south China. To achieve this, the basin was divided into 909,824 grid cells, to each of which a Manning coefficient was assigned based on its land use type interpreted from remote sensing data. A sensitivity analysis was conducted for three typical flood processes under four types of surface runoff coefficients, assumed a priori, upon three error functions. The results demonstrate the crucial role of the surface runoff coefficient in achieving better simulation accuracy and reveal that this coefficient varies with flood scale and is unevenly distributed over the basin.

  12. Guidelines for acceptable soil concentrations in the Old F- and H-Area Retention Basins. Revision 1

    International Nuclear Information System (INIS)

    Hamby, D.M.

    1994-01-01

    Concentration guidelines for residual radionuclides in soil at the sites of the Old F- and a Retention Basins (281-3F, 281-3H) have been calculated using a dose-based approach. The guidelines also are being applied to areas around the F-Basin's Process Line. Estimation of these soil guidelines was completed using RESRAD 5.0 in accordance with the DOE RESRAD methodology specified in DOE/CH/8901 (Gi89). Guidelines are provided for the nuclides known to be present in the soils at each basin (Sc87). Soil and hydrologic characteristics specific to each basin are defined for the areas above, within, and beneath the contaminated zones

  13. Chemical character of the partially flooded Smythii Basin based on Al/Si orbital X-ray data

    Science.gov (United States)

    Andre, C. G.; Adler, I.; Clark, P. E.; Weidner, J. R.; Wolfe, R. W.; Philpotts, J. A.

    1977-01-01

    Orbital X-ray fluorescence data indicate that continuous mare-basalt flooding is confined to the northeastern quadrant of the Smythii Basin. Al/Si values for soils in the unflooded northwestern section of the Smythii Basin closely approximate those for the adjacent terra to the west. Terra soils east of Mare Smythii, however, are unusually aluminous compared to terra soils west of the basin. This pronounced contrast between Al/Si values for terra soils to the east and west of Smythii as well as the minimal difference in values between the northwestern section of the basin and adjacent terra to the west are most likely due to a chemically homogeneous layer of ejecta from a large impact event west of Mare Smythii, such as that which formed the Crisium Basin. An alternate hypothesis is that the unflooded section of the basin is predominantly original basin floor material, indicating that the impact forming the 4km deep Smythii Basin did not penetrate into a horizon chemically different from the terra west of Smythii. The chemical contrast between the terra east and west of Smythii, then, would be ascribed to lateral heterogeneity within the lunar crust

  14. Modelling the flood-risk extent using LISFLOOD-FP in a complex watershed: case study of Mundeni Aru River Basin, Sri Lanka

    Science.gov (United States)

    Amarnath, G.; Umer, Y. M.; Alahacoon, N.; Inada, Y.

    2015-06-01

    Flood management is adopting a more risk-based approach, whereby flood risk is the product of the probability and consequences of flooding. Two-dimensional flood inundation modeling is a widely used tool to aid flood-risk management. The aim of this study is to develop a flood inundation model that uses historical flow data to produce flood-risk maps, which will help to identify flood protection measures in the rural areas of Sri Lanka. The LISFLOOD-FP model was developed at the basin scale using available historical data, and also through coupling with a hydrological modelling system, to map the inundation extent and depth. Results from the flood inundation model were evaluated using Synthetic Aperture Radar (SAR) images to assess product accuracy. The impacts of flooding on agriculture and livelihoods were analyzed to assess the flood risks. It was identified that most of the areas under paddy cultivation that were located near the middle and downstream part of the river basin are more susceptible to flood risks. This paper also proposes potential countermeasures for future natural disasters to prevent and mitigate possible damages.

  15. Data evaluation technical memorandum on the K-1407C Retention Basin at the Oak Ridge K-25 Site, Oak Ridge, Tennessee. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Beal, D.; Bock, J.; Hatmaker, T.; Zolyniak, J.; Goddard, P. [Oak Ridge K-25 Site, TN (United States); Kucsmas, D. [Oak Ridge National Lab., TN (United States)

    1991-10-01

    The K-1407-C Retention Basin was a surface impoundment at the Oak Ridge K-25 Site. The basin was used primarily for storing potassium hydroxide scrubber sludge generated at the K-25 Site. In addition, from 1960 to 1973, metal hydroxide sludges that were removed from the K-1407-B Holding Pond were discharged to the K-1407-C Retention Basin. The sludge in the K-1407-B Pond contained discharge from the K-1420 Decontamination and Uranium Recovery, the K-1501 Steam Plant, the K-1413 Laboratory, and the K-1401 Maintenance Building. Radioactive material is also present in the K-1407-C Retention Basin, probably the result of cleaning and decontamination activities at some of the aforementioned facilities. The discharge of waste materials to K-1407-C was discontinued before November of 1988, and all sludge was removed from the retention basin. Some of the sludge was stored, and the remainder was fixed in concrete. This report is specific to the K-1407-C Retention Basin and includes information pertinent to the evaluation of soil contamination. The focus of this evaluation is the effectiveness of the Phase 1 investigation of the K-1407-C Retention Basin to define site conditions adequately to support decisions regarding appropriate closure alternatives. This includes the physical characterization of the site area and the characterization of the nature and extent of contamination at the site in relation to risk characterization and statistical evaluation.

  16. Data evaluation technical memorandum on the K-1407C Retention Basin at the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Beal, D.; Bock, J.; Hatmaker, T.; Zolyniak, J.; Goddard, P. (Oak Ridge K-25 Site, TN (United States)); Kucsmas, D. (Oak Ridge National Lab., TN (United States))

    1991-10-01

    The K-1407-C Retention Basin was a surface impoundment at the Oak Ridge K-25 Site. The basin was used primarily for storing potassium hydroxide scrubber sludge generated at the K-25 Site. In addition, from 1960 to 1973, metal hydroxide sludges that were removed from the K-1407-B Holding Pond were discharged to the K-1407-C Retention Basin. The sludge in the K-1407-B Pond contained discharge from the K-1420 Decontamination and Uranium Recovery, the K-1501 Steam Plant, the K-1413 Laboratory, and the K-1401 Maintenance Building. Radioactive material is also present in the K-1407-C Retention Basin, probably the result of cleaning and decontamination activities at some of the aforementioned facilities. The discharge of waste materials to K-1407-C was discontinued before November of 1988, and all sludge was removed from the retention basin. Some of the sludge was stored, and the remainder was fixed in concrete. This report is specific to the K-1407-C Retention Basin and includes information pertinent to the evaluation of soil contamination. The focus of this evaluation is the effectiveness of the Phase 1 investigation of the K-1407-C Retention Basin to define site conditions adequately to support decisions regarding appropriate closure alternatives. This includes the physical characterization of the site area and the characterization of the nature and extent of contamination at the site in relation to risk characterization and statistical evaluation.

  17. Flood-plain and channel aggradation of selected bridge sites in the Iowa and Skunk River basins, Iowa

    Science.gov (United States)

    Eash, D.A.

    1996-01-01

    Flood-plain and channel-aggradation rates were estimated at 10 bridge sites on the Iowa River upstream of Coralville Lake and at two bridge sites in the central part of the Skunk River Basin. Four measurement methods were used to quantify aggradation rates: (1) a dendrogeomorphic method that used tree-age data and sediment-deposition depths, (2) a bridge-opening cross-section method that compared historic and recent cross sections of bridge openings, (3) a stage-discharge rating-curve method that compared historic and recent stages for the 5-year flood discharge and the average discharge, and (4) nine sediment pads that were installed on the Iowa River flood plain at three bridge sites in the vicinity of Marshalltown. The sediment pads were installed prior to overbank flooding in 1993. Sediments deposited on the pads as a result of the 1993 flood ranged in depth from 0.004 to 2.95 feet. Measurement periods used to estimate average aggradation rates ranged from 1 to 98 years and varied among methods and sites. The highest aggradation rates calculated for the Iowa River Basin using the dendrogeomorphic and rating- curve measurement methods were for the State Highway 14 crossing at Marshalltown, where these highest rates were 0.045 and 0.124 feet per year, respectively. The highest aggradation rates calculated for the Skunk River Basin were for the U.S. Highway 63 crossing of the South Skunk River near Oskaloosa, where these highest rates were 0.051 and 0.298 feet per year, respectively.

  18. Modelling non-stationary annual maximum flood heights in the lower Limpopo River basin of Mozambique

    Directory of Open Access Journals (Sweden)

    Daniel Maposa

    2016-05-01

    Full Text Available In this article we fit a time-dependent generalised extreme value (GEV distribution to annual maximum flood heights at three sites: Chokwe, Sicacate and Combomune in the lower Limpopo River basin of Mozambique. A GEV distribution is fitted to six annual maximum time series models at each site, namely: annual daily maximum (AM1, annual 2-day maximum (AM2, annual 5-day maximum (AM5, annual 7-day maximum (AM7, annual 10-day maximum (AM10 and annual 30-day maximum (AM30. Non-stationary time-dependent GEV models with a linear trend in location and scale parameters are considered in this study. The results show lack of sufficient evidence to indicate a linear trend in the location parameter at all three sites. On the other hand, the findings in this study reveal strong evidence of the existence of a linear trend in the scale parameter at Combomune and Sicacate, whilst the scale parameter had no significant linear trend at Chokwe. Further investigation in this study also reveals that the location parameter at Sicacate can be modelled by a nonlinear quadratic trend; however, the complexity of the overall model is not worthwhile in fit over a time-homogeneous model. This study shows the importance of extending the time-homogeneous GEV model to incorporate climate change factors such as trend in the lower Limpopo River basin, particularly in this era of global warming and a changing climate. Keywords: nonstationary extremes; annual maxima; lower Limpopo River; generalised extreme value

  19. Impact of climatic and environmental changes on flood-duration-frequencies in the Fengle Rriver (YangTze Basin, China)

    Science.gov (United States)

    Salles, Christian; Chu, Yin; Tournoud, Marie-George; Ou, Mengli; Perrin, Jean-Louis; Cres, François-Noël; Ma, Youhua

    2016-04-01

    Future water management challenges such as flood risk are highly relevant to climate and land use changes. Climate change is expected to lead to an ongoing intensification of effects on changes in precipitation and evapotranspiration which could exacerbate flooding issues. Land use changes, modifications of agricultural practices and urbanization alter the apportionment of the different hydrological processes at the basin scale and could significantly affect the seasonality of streamflow. At the local scale, the consequences of climate and land use changes on flood occurrence and magnitude are a major issue for the economic development and management policy of basin area. This study apply a methodology for investigating the potential consequences of land use ,as well as precipitation and temperature changes on flood occurrence, duration and magnitude, accounting for uncertainties in scenario data and hydrological model parameters. The discharge time series predicted for the future were simulated from a calibrated and validated distributed hydrological model. The model was run from inputs which are -predicted rainfall time series based on scenarios of changes identified from a literature review, -future evapotranspiration rates assessed from temperature changes identified from a literature review -and scenarios of land-use changes The study area, the Fengle River basin (1500 km2), is located in the northeast part of Yangtze basin. The river is one of the main tributaries of the Chao Lake, the fifth largest natural lake of China. The lake catchment is 9130 km2 in area, including the city of Hefei and a large extent of agricultural and rural areas. Many changes are expected in land use and agricultural practices in the future, due to the touristic appeal of the Chao Lake shore and the growth of the city of Hefei. Climate changes are also expected in this region, with a high impact on rainfall regime. In the current period heavy storms and floods occur predominantly

  20. A study of CO2 flooding on wave velocities in the Naharkatiya oil reservoir of Upper Assam Basin

    Directory of Open Access Journals (Sweden)

    Subrata Borgohain Gogoi

    2017-03-01

    Full Text Available This paper studies the compressional-wave and shear-wave velocities in the laboratory in six conventional core plugs. These plugs were obtained from a depth of more than 3000 m from the producing horizons of Naharkatiya oil reservoir of Upper Assam Basin, India. The porosities of the conventional core plugs were from 9.67 to 25.8% and that of unconsolidated sand pack was 47%. These plugs and sand pack were saturated with n-hexadecane before CO2 flooding. It was observed that during flooding compressional-wave velocities decreased more than the shear wave velocities. These decreases in wave velocity depend on confining pressure, pore pressure, porosity and temperature of the plugs. Increasing pore pressure at constant confining pressure not only keeps the pores and cracks open but also reduces the confining pressure effect and increases the CO2 density. Higher pore pressures causes larger decrease in both compressional and shear wave velocities. In case of conventional core plugs which are consolidated, having lower porosities tends to decrease the CO2 effect. In unconsolidated sand pack the flooding effect is large even though porosity is high because the bulk modulus of the sand is low. The experimental and the theoretical analyses in this paper show that the decrease in compressional-wave velocities caused by CO2 flooding makes it possible to track CO2 front movements and monitor CO2 flooding process in the reservoir.

  1. Local and regional estimation of floods in the Timis and Bega hydrographic basins: application of converging QDF model concept

    International Nuclear Information System (INIS)

    Mic, Rodica; Gaida, Gilles

    2004-01-01

    A flow-duration-frequency regionalisation is carried out on the Timis and Bega rivers sub-catchments in the west of Romania. This regionalisation concerns 28 sub-catchments having about thirty years of stream flow measurements (daily flow, instantaneous flood peaks and hydrographs). This work about the floods regionalisation is realized in the framework of the European project Riverlife. The regional model will allow defining the hydrographs of project necessary for the hydraulic modelling. This hydraulic project is necessary in order to protect Timisoara - city against the floods. The method uses the hypotheses of the converging QdF model and adapts the index flood method for obtaining a regional dimensionless distribution. For long return periods, this approach uses the GRADEX method, which extrapolates discharge distributions according to the rainfall distributions. The dimensionless regional QdF model needs two local descriptors of target site to be denormed: QIXA10 and Δ: the annual maximum instantaneous flow with a 10% probability to be exceeded (the 10-year peak flood) and a characteristic duration, respectively. For these both variables, the relations obtained by regression are presented, involving morphologic and climatic basin characteristics.(Author)

  2. Assessment of water retention function as tool to improve integrated watershed management (case study of Poprad river basin, Slovakia).

    Science.gov (United States)

    Šatalová, Barbora; Kenderessy, Pavol

    2017-12-01

    The presented study concentrates on assessing the ecosystem function of water retention. The water retention function is defined as the ability of the landscape to retain water, slow runoff and encourage water infiltration. The water retention function was expressed by calculating the hydric significance (HS) indicator. This method is based on scoring the individual input parameters according to their overall impact on watershed hydrology. The study was conducted on a sample area of Poprad River basin. The final results presented a spatial distribution of hydric function within the watershed classified according to its significance into four classes (from limited to excellent significance). A breakdown of the results on the level of elementary watersheds was used in order to examine those with low hydric function. The results showed a significant influence of land-use on retention function; however, this impact could be limited by extreme precipitation or high soil water saturation. The methodology of hydric significance represents an innovative approach towards assessment of ecosystem function of water retention on regional level. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Flood inundation modeling and hazard mapping under uncertainty in the Sungai Johor basin, Malaysia

    NARCIS (Netherlands)

    Md. Ali, A.

    2018-01-01

    Flooding can have devastating impacts on people’s livelihood, economy and the environment. An important instrument in flood management is floodplain maps, which assist land planners and local authorities in identifying flood-prone areas, and provide useful information for rescue and relief agencies

  4. Transport and Retention of Nitrogen, Phosphorus and Carbon in North America’s Largest River Swamp Basin, the Atchafalaya River Basin

    Directory of Open Access Journals (Sweden)

    Y. Jun Xu

    2013-04-01

    Full Text Available Floodplains and river corridor wetlands may be effectively managed for reducing nutrients and carbon. However, our understanding is limited to the reduction potential of these natural riverine systems. This study utilized the long-term (1978–2004 river discharge and water quality records from an upriver and a downriver location of the Atchafalaya River to quantify the inflow, outflow, and inflow–outflow mass balance of total Kjeldahl nitrogen (TKN = organic nitrogen + ammonia nitrogen, nitrate + nitrite nitrogen (NO3 + NO2, total phosphorous (TP, and total organic carbon (TOC through the largest river swamp basin in North America. The study found that, over the past 27 years, the Atchafalaya River Basin (ARB acted as a significant sink for TKN (annual retention: 24%, TP (41%, and TOC (12%, but a source for NO3 + NO2 nitrogen (6%. On an annual basis, ARB retained 48,500 t TKN, 16,900 t TP, and 167,100 t TOC from the river water. The retention rates were closely and positively related to the river discharge with highs during the winter and spring and lows in the late summer. The higher NO3 + NO2 mass outflow occurred throughout spring and summer, indicating an active role of biological processes on nitrogen as water and air temperatures in the basin rise.

  5. FACIES ANALYSIS, STRATIGRAPHY AND PALAEONTOLOGY (MOLLUSCS AND VERTEBRATES IN THE UPPER PLIOCENE SANDY FLOOD-BASIN DEPOSITS OF THE UPPER VALDARNO BASIN (NORTHERN APENNINES

    Directory of Open Access Journals (Sweden)

    MASSIMILIANO GHINASSI

    2005-11-01

    Full Text Available The Upper Valdarno Basin, one of the most investigated Neogene–Quaternary basins of the Northern Apennines, developed during three main phases, as testified by the occurrence of three unconformity-bounded stratigraphic units (UBSUs in the basin infill. Despite numerous studies having been carried out, biochronological, paleoecological and stratigraphical issues in the lower portion of the Montevarchi Synthem (second phase have yet to be understood. Sandy deposits (Montecarlo Sand and Silt Unit, stratigraphically located in this portion of the Montevarchi Synthem, are the focus of this multidisciplinary study. These deposits conformably overlie sandy fluvio-eolian sediments and are, in turn, capped by fluvio-palustrine deposits through a progressive unconformity. Facies analysis suggest a sandy flood-basin environment for these deposits, characterised by variations in water discharge and flood event energy. Mollusc and fish remains, pointing to quiet or slow-moving shallow waters, have been affected by transport processes before final burial in overbank areas. Fish remains of the primary marine family Mugilids highlight a connection between the basin and the sea that was previously only supposed. Small mammal remains, referred to the rodent Mimomys polonicus, are coherent with a water-rich environment. Cyclic variations in shell content and sedimentological characteristics testify to the occurrence of short-term climatic oscillations during this warming phase. This study fits with paleomagnetic and radiometric datings and mammal biochronology, in indicating that the Montecarlo Sand and Silt Unit belongs to a time interval preceding the Reunion paleomagnetic event. The depositional evolution of the Montecarlo Unit was driven by climatic change from arid to humid conditions, related to a global increase in temperature that occurred between 2.4 and 2.2 Ma.

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

    International Nuclear Information System (INIS)

    Olang, L. O.

    2009-01-01

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

  7. A case study on the diagnosis and consequences of flash floods in south-western Romania: The upper basin of Desnatui River

    Directory of Open Access Journals (Sweden)

    Morosanu Gabriela Adina

    2014-01-01

    Full Text Available The paper examines the flash floods that may appear in a representative river basin occupying the south-western Romania and also feature an example of the most recent flash flood from 2005-2006, more specifically, its causes and consequences. In order to accomplish the objectives, hydrological data were used to identify the characteristics of the floods. Finally, the case study of the flash flood was delivered through the field research, observational method, discussion with the authorities and investigation of the meteorological and hydrological available data. The research offers an insight on the dimension of damages triggered by a flash flood event, based on the statistical data provided by the village hall and the few remaining places preserving the traces of the floods (houses, bridges. Because we could not provide all the necessary data in order to determine the frequency and scale of such risk phenomena, the analysis is assessed on general hydrological statistics of flood events between 1964 to 2011. By leading the research, it resulted that the specific feature of the upper basin of Desnatui River is its temporary drainage and that in the periods of high flow, the capacity of the river channels is diminshed and the floods may occur. The paper succeeds to revive the insufficient scientific concerns on this kind of hydrological risks issued in the space occupied by the upper basin of Desnatui River and eventually, to supply the need for such study in the context of modern hydrological research preoccupations.

  8. Pre- and post-processing of hydro-meteorological ensembles for the Norwegian flood forecasting system in 145 basins.

    Science.gov (United States)

    Jahr Hegdahl, Trine; Steinsland, Ingelin; Merete Tallaksen, Lena; Engeland, Kolbjørn

    2016-04-01

    Probabilistic flood forecasting has an added value for decision making. The Norwegian flood forecasting service is based on a flood forecasting model that run for 145 basins. Covering all of Norway the basins differ in both size and hydrological regime. Currently the flood forecasting is based on deterministic meteorological forecasts, and an auto-regressive procedure is used to achieve probabilistic forecasts. An alternative approach is to use meteorological and hydrological ensemble forecasts to quantify the uncertainty in forecasted streamflow. The hydrological ensembles are based on forcing a hydrological model with meteorological ensemble forecasts of precipitation and temperature. However, the ensembles of precipitation are often biased and the spread is too small, especially for the shortest lead times, i.e. they are not calibrated. These properties will, to some extent, propagate to hydrological ensembles, that most likely will be uncalibrated as well. Pre- and post-processing methods are commonly used to obtain calibrated meteorological and hydrological ensembles respectively. Quantitative studies showing the effect of the combined processing of the meteorological (pre-processing) and the hydrological (post-processing) ensembles are however few. The aim of this study is to evaluate the influence of pre- and post-processing on the skill of streamflow predictions, and we will especially investigate if the forecasting skill depends on lead-time, basin size and hydrological regime. This aim is achieved by applying the 51 medium-range ensemble forecast of precipitation and temperature provided by the European Center of Medium-Range Weather Forecast (ECMWF). These ensembles are used as input to the operational Norwegian flood forecasting model, both raw and pre-processed. Precipitation ensembles are calibrated using a zero-adjusted gamma distribution. Temperature ensembles are calibrated using a Gaussian distribution and altitude corrected by a constant gradient

  9. Characterizing climate-change impacts on the 1.5-yr flood flow in selected basins across the United States: a probabilistic approach

    Science.gov (United States)

    Walker, John F.; Hay, Lauren E.; Markstrom, Steven L.; Dettinger, Michael D.

    2011-01-01

    The U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) model was applied to basins in 14 different hydroclimatic regions to determine the sensitivity and variability of the freshwater resources of the United States in the face of current climate-change projections. Rather than attempting to choose a most likely scenario from the results of the Intergovernmental Panel on Climate Change, an ensemble of climate simulations from five models under three emissions scenarios each was used to drive the basin models. Climate-change scenarios were generated for PRMS by modifying historical precipitation and temperature inputs; mean monthly climate change was derived by calculating changes in mean climates from current to various future decades in the ensemble of climate projections. Empirical orthogonal functions (EOFs) were fitted to the PRMS model output driven by the ensemble of climate projections and provided a basis for randomly (but representatively) generating realizations of hydrologic response to future climates. For each realization, the 1.5-yr flood was calculated to represent a flow important for sediment transport and channel geomorphology. The empirical probability density function (pdf) of the 1.5-yr flood was estimated using the results across the realizations for each basin. Of the 14 basins studied, 9 showed clear temporal shifts in the pdfs of the 1.5-yr flood projected into the twenty-first century. In the western United States, where the annual peak discharges are heavily influenced by snowmelt, three basins show at least a 10% increase in the 1.5-yr flood in the twenty-first century; the remaining two basins demonstrate increases in the 1.5-yr flood, but the temporal shifts in the pdfs and the percent changes are not as distinct. Four basins in the eastern Rockies/central United States show at least a 10% decrease in the 1.5-yr flood; the remaining two basins demonstrate decreases in the 1.5-yr flood, but the temporal shifts in the pdfs

  10. THE ASSESSMENT OF FLOODS WITHIN COŞUŞTEA RIVER BASIN, ROMANIA (2000 - 2012. A STATISTICAL AND CONDITIONAL APPROACH

    Directory of Open Access Journals (Sweden)

    MOROȘANU GABRIELA ADINA

    2015-03-01

    Full Text Available The research aims to analyze the floods that occurred between 2000 and 2012 in the Coșuștea river basin, Romania. The study area has 449 km2 and it is extended over the north-western part of Getic Piedmont (lower sector, as well as on Mehedinti Plateau and Mountains, in its upper sector. To achieve the objectives, hydrological data from two hydrometric stations, Corcova (downstream, located in the piedmont area and Șișești (upstream to the outlet of karstic upper section were used, in order to identify trends, employing statistical methods and graphical representations. We also verified the existence of extraordinary levels, respectively conditions responsible for the differences in the maximum flows, their frequency and duration in the two measured sections of the river basin. Thus, the results include: the statistical treatment of hydrologic data on floods between 2000 and 2012 and contributing factors that may result in different values of flood elements at the two hydrometric stations.

  11. Implementation and Evaluation of the Streamflow Statistics (StreamStats) Web Application for Computing Basin Characteristics and Flood Peaks in Illinois

    Science.gov (United States)

    Ishii, Audrey L.; Soong, David T.; Sharpe, Jennifer B.

    2010-01-01

    Illinois StreamStats (ILSS) is a Web-based application for computing selected basin characteristics and flood-peak quantiles based on the most recently (2010) published (Soong and others, 2004) regional flood-frequency equations at any rural stream location in Illinois. Limited streamflow statistics including general statistics, flow durations, and base flows also are available for U.S. Geological Survey (USGS) streamflow-gaging stations. ILSS can be accessed on the Web at http://streamstats.usgs.gov/ by selecting the State Applications hyperlink and choosing Illinois from the pull-down menu. ILSS was implemented for Illinois by obtaining and projecting ancillary geographic information system (GIS) coverages; populating the StreamStats database with streamflow-gaging station data; hydroprocessing the 30-meter digital elevation model (DEM) for Illinois to conform to streams represented in the National Hydrographic Dataset 1:100,000 stream coverage; and customizing the Web-based Extensible Markup Language (XML) programs for computing basin characteristics for Illinois. The basin characteristics computed by ILSS then were compared to the basin characteristics used in the published study, and adjustments were applied to the XML algorithms for slope and basin length. Testing of ILSS was accomplished by comparing flood quantiles computed by ILSS at a an approximately random sample of 170 streamflow-gaging stations computed by ILSS with the published flood quantile estimates. Differences between the log-transformed flood quantiles were not statistically significant at the 95-percent confidence level for the State as a whole, nor by the regions determined by each equation, except for region 1, in the northwest corner of the State. In region 1, the average difference in flood quantile estimates ranged from 3.76 percent for the 2-year flood quantile to 4.27 percent for the 500-year flood quantile. The total number of stations in region 1 was small (21) and the mean

  12. Remedial technology and characterization development at the SRS F/H Retention Basins using the DOE SAFER methodology

    International Nuclear Information System (INIS)

    Miles, W.C. Jr.; Kuelske, K.J.

    1994-01-01

    The Streamlined Approach For Environmental Restoration (SAFER) is a strategy used to accelerate and improve the environmental assessment and remediation of the F/H Retention Basins at the Savannah River Site (SRS). TMs strategy combines the data quality objectives (DQO) process and the observational approach to focus on data collection and converge on a remedial action early. This approach emphasizes stakeholder involvement throughout the Remedial Investigation/Feasibility Study (RI/FS) process. The SAFER methodology is being applied to the characterization, technology development, and remediation tasks for the F/H Retention Basins. This ''approach was initiated in the scoping phase of these projects through the involvment of major stakeholders; Department of Energy (DOE)-Savannah River Field Office, DOE-Headquarters, Westinghouse Savannah River Company, United States Environmental Protection Agency (EPA) Region IV, and the state of South Carolina Department of Health and Environmental Control (SCDHEC), in the development of the Remedial Investigation (RI) workplans. A major activity that has been initiated is the development and implementation of a phase I workplan to identify preliminary contaminants of concern (pCOCs). A sampling plan was developed and approved by the major stakeholders for preliminary characterization of wastes remaining in the F/H Retention Basins. The involvement of stakeholders, development of a site conceptual model, development of remedial objectives for probable conditions, identification of the problem and reasonable deviations, and development of initial decision rules in the planning stages will ensure that preliminary data needs are identified and obtained prior to the initiation of the assessment and implementation phases of the projects resulting in the final remediation of the sites in an accelerated and more cost effective manner

  13. Quantification of the cumulative effects of river training works on the basin scale with 2D flood modelling

    Science.gov (United States)

    Zischg, Andreas Paul; Felder, Guido; WWeingartner, Rolf

    2015-04-01

    The catchment of the river Aare upstream of Bern, Switzerland, with an area of approx. 3000 km2 is a complex network of sub-catchments with different runoff characteristics; it also includes two larger lakes. Most of the rivers were regulated in the 18th century. An important regulation, however, was realised as early as in the 17th century. For this catchment, the worst case flood event was identified and its consequences were analysed. Beside the hydro-meteorological characteristics, an important basis to model the worst case flood is to understand the non-linear effects of flood retention in the valley bottom and in the lakes. The aim of this study was to compare these effects based on both the current river network and the historic one prior to the main river training works. This allows to quantify the human impacts. Methodologically, we set up a coupled 2D flood model representing the floodplains of the river Aare as well as of the tributaries Lombach, Lütschine, Zulg, Rotache, Chise and Guerbe. The flood simulation was made in 2D with the software BASEMENT-ETH (Vetsch et al. 2014). The model was calibrated by means of reproducing the large floods in August 2005 and the bankfull discharge for all river reaches. The model computes the discharge at the outlet of the Aare catchment at Bern by routing all discharges from the sub-catchments through the river reaches and their floodplains. With this, the modulation of the input hydrographs by widespread floodings in the floodplains can be quantified. The same configuration was applied on the basis of reconstructed digital terrain models representing the landscape and the river network before the first significant river training works had been realised. This terrain model was reconstructed by georeferencing and digitalizing historic maps and cross-sections combined with the mapping of the geomorphologic evidences of former river structures in non-modified areas. The latter mapping procedure was facilitated by the

  14. Otter Brook Lake, New Hampshire Connecticut River Basin, Flood Control Project, Solid Waste Management Plan

    National Research Council Canada - National Science Library

    1996-01-01

    .... This plan provides guidance to establish policies, and responsibilities, procedures, and instructions for proper handling, storage, disposal and recycling of solid waste generated at the flood control project...

  15. Monitoring of levees, bridges, pipelines, and other critical infrastructure during the 2011 flooding in the Mississippi River Basin: Chapter J in 2011 floods of the central United States

    Science.gov (United States)

    Densmore, Brenda K.; Burton, Bethany L.; Dietsch, Benjamin J.; Cannia, James C.; Huizinga, Richard J.

    2014-01-01

    During the 2011 Mississippi River Basin flood, the U.S. Geological Survey evaluated aspects of critical river infrastructure at the request of and in support of local, State, and Federal Agencies. Geotechnical and hydrographic data collected by the U.S. Geological Survey at numerous locations were able to provide needed information about 2011 flood effects to those managing the critical infrastructure. These data were collected and processed in a short time frame to provide managers the ability to make a timely evaluation of the safety of the infrastructure and, when needed, to take action to secure and protect critical infrastructure. Critical infrastructure surveyed by the U.S. Geological Survey included levees, bridges, pipeline crossings, power plant intakes and outlets, and an electrical transmission tower. Capacitively coupled resistivity data collected along the flood-protection levees surrounding the Omaha Public Power District Nebraska City power plant (Missouri River Levee Unit R573), mapped the near-subsurface electrical properties of the levee and the materials immediately below it. The near-subsurface maps provided a better understanding of the levee construction and the nature of the lithology beneath the levee. Comparison of the capacitively coupled resistivity surveys and soil borings indicated that low-resistivity value material composing the levee generally is associated with lean clay and silt to about 2 to 4 meters below the surface, overlying a more resistive layer associated with sand deposits. In general, the resistivity structure becomes more resistive to the south and the southern survey sections correlate well with the borehole data that indicate thinner clay and silt at the surface and thicker sand sequences at depth in these sections. With the resistivity data Omaha Public Power District could focus monitoring efforts on areas with higher resistivity values (coarser-grained deposits or more loosely compacted section), which typically are

  16. Development of Predictive Relationships for Flood Hazard Assessments in Ungaged Basins

    Science.gov (United States)

    2016-02-01

    River basin and (b) Mindanao River basin. LAND USE DATA: Land cover digital data was downloaded from the Global Land ...index map for the hydrological models of Cagayan and Mindanao River basins. The maps in Figure 5 (a)(b) were applied to assign land use properties...CHETN-VIII-8 February 2016 6 (a) (b) Figure 5. Land use classification for (a) Cagayan River basin and (b) Mindanao River

  17. Flood Hazard Zonation by Combining Mod-Clark and HEC-RAS Models in Bustan Dam Basin, Golestan Province

    Directory of Open Access Journals (Sweden)

    Z. Parisay

    2014-12-01

    Full Text Available Flood is one of the devastating phenomena which every year incurs casualties and property damages. Flood zonation is an efficient technique for flood management. The main goal of this research is flood hazard and risk zonation along a 21 km reach of the Gorganrud river in Bustan dam watershed considering two conditions: present landuse condition and scenario planning. To this end a combination of a hydrologic model (the distributed HEC-HMS with the Mod-Clark transform option and a hydraulic model (HEC-RAS were used. The required inputs to run the Mod-Clarck module of HEC-HMS are gridded files of river basin, curve number and rainfall with the SHG coordinate system and DSS format. In this research the input files were prepared using the Watershed Modeling System (WMS at cell size of 200 m. Since the Mod-Clark method requires rainfall data as radar format (NEXRAD, the distributed rainfall mapseries with time intervals of 15 minutes prepared within the PCRaster GIS system were converted to the DSS format using the asc2dss package. also the curve number map was converted to the DSS format using HEC-GeoHMS. Then, these DSS files were substituted with rainfall and curve number maps within the WMS. After calibration and validation, model was run for return periods of 2, 5, 10, 25, 50, 100 and 200 years, in two conditions of current landuse and scenario planning. The simulated peak discharge data, geometric parameters of river and cross section (at 316 locations data prepared by the HEC-GeoRAS software and roughness coefficients data, were used by the HEC-RAS software to simulate the hydraulic behavior of the river and flood inundation area maps were produced using GIS. The results of the evaluation showed that in addition to the percent error in peak flow, less than 3.2%, the model has a good performance in peak flow simulation, but is not successful in volume estimation. The results of flood zones revealed that from the total area in floodplain with

  18. Retention efficiencies of halogenated and non-halogenated hydrocarbons in selected wetland ecosystem in Lake Victoria Basin

    Directory of Open Access Journals (Sweden)

    Shadrack Mule

    2015-06-01

    Full Text Available The determination of retention efficiencies of halogenated and non-halogenated hydrocarbon in selected wetland ecosystems in Lake Victoria basin was carried out. Qualitative and quantitative determination of the presence of residual hydrocarbons in Kigwal/Kimondi, Nyando and Nzoia wetland ecosystems using Gas Chromatography - Mass Spectrometer (GC-MS instrument indicated the presence of residual organochlorines, organophosphorus, carbamates and synthetic pyrethroid hydrocarbons in water, sediment and plant materials. In order to compare the retention efficiencies of the wetlands, the wetland ecosystems were divided into three different sections, namely: inlet, mid and outlet. Calculations of mass balances of residual halogenated and non-halogenated hydrocarbons at the respective sections was done taking into account the partition of the studied compounds in samples of water, sediments and papyrus reed plant materials and analyzed using validated Gas Chromatography - Mass Spectrometer (GC-MS method. From the analysis, several residual hydrocarbons namely: bendiocarb, benzene hexachloride (BHC, carbaryl, cypermethrin, decis, deltamethrin, diazinon, dieldrin, DDT, DDD, DDE, malathion, propoxur, sumithion, 5-phenylrhodanine, 1,3,5-trichlorobenzene, 1-(2-phenoxybenzylhydrazine were detected and quantified. The levels of the selected residual hydrocarbons in water samples were used to calculate the retention efficiencies of a specific hydrocarbon and the values recorded. Generally, River Nyando wetland recorded mean percentage retention efficiencies of 76 and 94% for dry and rainy seasons respectively; Kigwal/Kimondi wetland had seasonal mean percentage retention efficiencies of 63 to 78%. River Nzoia also had calculated seasonal mean percentage retention efficiencies of between 56 to 88%. Dry season had lower mean percentages retention efficiencies as compared to rainy season in the three wetlands of interest during the period of study. The study

  19. A GIS based flood risk mapping along the Niger-Benue river basin in ...

    African Journals Online (AJOL)

    They have become common occurrences in every part Nigeria and the recorded impacts of flooding on the inhabitants are alarming, causing hundreds of deaths and rendering thousands homeless. The impact of floods on people globally has led to the development of mitigation measures that could reduce the associated ...

  20. Flood risk index pattern assessment: case study in Langat River Basin

    African Journals Online (AJOL)

    This study focus on the creation of flood risk index in the study area based on secondary data derived from the Department of Drainage and Irrigation (DID) since 1982-2012. Based on the result, it shows that the water level is the best variable to be taken for the purposed of flood warning alert system as the result for ...

  1. Flooding studies of proposed repository locations in the Palo Duro Basin of the Texas Panhandle

    International Nuclear Information System (INIS)

    1985-04-01

    This report contains the results of flooding studies of those stream channels that drain the proposed locations of a high-level nuclear-waste repository in Deaf Smith and Swisher Counties, Texas. Included are computations of the flood hydrographs and water surface profiles of the 100-year, 500-year, and probable maximum floods for Palo Duro Creek, Tule Creek, and Pleasant Draw. The hydrographs were produced according to the method of the Soil Conservation Service for ungaged watersheds, and the computations were made with computer programs developed by the US Army Corps of Engineers. The flood hydrographs were computed with the HEC-1 Flood Hydrograph Package and the water surface elevations with the HEC-2 Water Surface Profiles program. 76 refs., 19 figs., 16 tabs

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

    Science.gov (United States)

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

    2017-12-01

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

  3. Environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system technology demonstration plan for use at the Savannah River Site F-Area Retention Basin

    Energy Technology Data Exchange (ETDEWEB)

    Williams, C.V.; Lockwood, G.J.; Normann, R.A. [Sandia National Labs., Albuquerque, NM (United States); Gruebel, R.D. [Tech Reps, Inc., Albuquerque, NM (United States)

    1996-08-01

    The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

  4. Environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system technology demonstration plan for use at the Savannah River Site F-Area Retention Basin

    International Nuclear Information System (INIS)

    Williams, C.V.; Lockwood, G.J.; Normann, R.A.; Gruebel, R.D.

    1996-08-01

    The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples

  5. Response of riparian vegetation across Australia's largest river basin to inter and intra-annual flooding: dynamics quantified from time series of Landsat and MODIS data

    Science.gov (United States)

    Broich, M.; Tulbure, M. G.; Keith, D.; Kingsford, R.; Lucas, R.; Lippmann, T.

    2014-12-01

    Australia is a continent subject to high rainfall variability. The resulting spatial-temporal pattern of flooding and its influence on riparian vegetation has not been quantified. Here we focused on the floodplains of the entire Murray-Darling Basin (MDB; 72 Landsat path-rows) of Australia as a case study. The MDB is the country's primary agricultural area with scarce water resources impacted by climate change and extensive zones with degrading riparian vegetation. We advance our understanding of the relationship between climate-driven flooding dynamics and vegetation response at the sub-continental to local and inter to intra-annual scale based on two decades of Landsat and one decade of MODIS imagery. We Landsat TM and ETM+ data to synoptically map spatially detailed dynamics of flooding with an internally consistent machine learning algorithm. We derived riparian phenology (Fig 1) from MODIS data and attributed differences in vegetation response to flooding dynamics, vegetation types and sub-basin land use. Vegetation community response to flooding varied in space and time and with vegetation types, densities and location relative to areas frequently flooded. Phenological degradation trends were observed over riparian forests and woodlands in the middle and lower parts of the basin that are primarily farmed and were we identified flooding regimes to have changed the most to less frequent and smaller inundation extents. Conversely, herbaceous vegetation phenology followed primarily a boom and bust cycle related to less extensive flooding dynamics. This pattern was found across different areas of the basin. As expected, flooding regimes and vegetation response patterns were fine grained confirming the choice of a spatially explicit, internally consistent analysis leading the path for ongoing monitoring. Remote sensing-based monitoring of the response of riparian vegetation to flooding can be used to quantify spatially explicit changes in vegetation community

  6. USE THE METHOD OF DIMENSIONING OF INFILTRATION-RETENTION BASINS FOR MANAGEMENT OF RAINWATER

    Directory of Open Access Journals (Sweden)

    Ewa Suchanek

    2015-01-01

    Full Text Available The easiest way to “use” rainwater is its detention in places where it falls, and referral to the ground. Systems of rainwater utilization system can be implemented in different variants. In the simplest configuration it is a tank, with a runoff from the roof. The principle of operation of the tank (basin is a method for rain water management. The article presents a practical application of methods of dimensioning infiltration basins by performing calculations showing how to alter the dimensions of the basin when changing the ground conditions while maintaining the same filling.

  7. Probable maximum flood in a changing climate: An overview for Canadian basins

    Directory of Open Access Journals (Sweden)

    Jacinthe Clavet-Gaumont

    2017-10-01

    New Hydrological Insights for the Region: The study reveals an overall increase in future spring PMP with the exception of the most northern basin Nelson. It showed a projected increase of the 100-year snowpack for the two northernmost basins, Nelson (8% and Manic-5 (3%, and a decrease for the three more southern basins, Mattagami (-1%, Saguenay (-5% and Kénogami (-9%. The future spring PMF is projected to increase with median values between -1.5% and 20%.

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

    Science.gov (United States)

    1991-07-18

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

  9. Coupled Land-Atmosphere Dynamics Govern Long Duration Floods: A Pilot Study in Missouri River Basin Using a Bayesian Hierarchical Model

    Science.gov (United States)

    Najibi, N.; Lu, M.; Devineni, N.

    2017-12-01

    Long duration floods cause substantial damages and prolonged interruptions to water resource facilities and critical infrastructure. We present a novel generalized statistical and physical based model for flood duration with a deeper understanding of dynamically coupled nexus of the land surface wetness, effective atmospheric circulation and moisture transport/release. We applied the model on large reservoirs in the Missouri River Basin. The results indicate that the flood duration is not only a function of available moisture in the air, but also the antecedent condition of the blocking system of atmospheric pressure, resulting in enhanced moisture convergence, as well as the effectiveness of moisture condensation process leading to release. Quantifying these dynamics with a two-layer climate informed Bayesian multilevel model, we explain more than 80% variations in flood duration. The model considers the complex interaction between moisture transport, synoptic-to-large-scale atmospheric circulation pattern, and the antecedent wetness condition in the basin. Our findings suggest that synergy between a large low-pressure blocking system and a higher rate of divergent wind often triggers a long duration flood, and the prerequisite for moisture supply to trigger such event is moderate, which is more associated with magnitude than duration. In turn, this condition causes an extremely long duration flood if the surface wetness rate advancing to the flood event was already increased.

  10. Model parameters conditioning on regional hydrologic signatures for process-based design flood estimation in ungauged basins.

    Science.gov (United States)

    Biondi, Daniela; De Luca, Davide Luciano

    2015-04-01

    The use of rainfall-runoff models represents an alternative to statistical approaches (such as at-site or regional flood frequency analysis) for design flood estimation, and constitutes an answer to the increasing need for synthetic design hydrographs (SDHs) associated to a specific return period. However, the lack of streamflow observations and the consequent high uncertainty associated with parameter estimation, usually pose serious limitations to the use of process-based approaches in ungauged catchments, which in contrast represent the majority in practical applications. This work presents the application of a Bayesian procedure that, for a predefined rainfall-runoff model, allows for the assessment of posterior parameters distribution, using the limited and uncertain information available for the response of an ungauged catchment (Bulygina et al. 2009; 2011). The use of regional estimates of river flow statistics, interpreted as hydrological signatures that measure theoretically relevant system process behaviours (Gupta et al. 2008), within this framework represents a valuable option and has shown significant developments in recent literature to constrain the plausible model response and to reduce the uncertainty in ungauged basins. In this study we rely on the first three L-moments of annual streamflow maxima, for which regressions are available from previous studies (Biondi et al. 2012; Laio et al. 2011). The methodology was carried out for a catchment located in southern Italy, and used within a Monte Carlo scheme (MCs) considering both event-based and continuous simulation approaches for design flood estimation. The applied procedure offers promising perspectives to perform model calibration and uncertainty analysis in ungauged basins; moreover, in the context of design flood estimation, process-based methods coupled with MCs approach have the advantage of providing simulated floods uncertainty analysis that represents an asset in risk-based decision

  11. Evaluation of medium-range ensemble flood forecasting based on calibration strategies and ensemble methods in Lanjiang Basin, Southeast China

    Science.gov (United States)

    Liu, Li; Gao, Chao; Xuan, Weidong; Xu, Yue-Ping

    2017-11-01

    Ensemble flood forecasts by hydrological models using numerical weather prediction products as forcing data are becoming more commonly used in operational flood forecasting applications. In this study, a hydrological ensemble flood forecasting system comprised of an automatically calibrated Variable Infiltration Capacity model and quantitative precipitation forecasts from TIGGE dataset is constructed for Lanjiang Basin, Southeast China. The impacts of calibration strategies and ensemble methods on the performance of the system are then evaluated. The hydrological model is optimized by the parallel programmed ε-NSGA II multi-objective algorithm. According to the solutions by ε-NSGA II, two differently parameterized models are determined to simulate daily flows and peak flows at each of the three hydrological stations. Then a simple yet effective modular approach is proposed to combine these daily and peak flows at the same station into one composite series. Five ensemble methods and various evaluation metrics are adopted. The results show that ε-NSGA II can provide an objective determination on parameter estimation, and the parallel program permits a more efficient simulation. It is also demonstrated that the forecasts from ECMWF have more favorable skill scores than other Ensemble Prediction Systems. The multimodel ensembles have advantages over all the single model ensembles and the multimodel methods weighted on members and skill scores outperform other methods. Furthermore, the overall performance at three stations can be satisfactory up to ten days, however the hydrological errors can degrade the skill score by approximately 2 days, and the influence persists until a lead time of 10 days with a weakening trend. With respect to peak flows selected by the Peaks Over Threshold approach, the ensemble means from single models or multimodels are generally underestimated, indicating that the ensemble mean can bring overall improvement in forecasting of flows. For

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

    Science.gov (United States)

    Villarini, Gabriele; Smith, James A.; Serinaldi, Francesco; Bales, Jerad; Bates, Paul D.; Krajewski, Witold F.

    2009-08-01

    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 110km) 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 2.1mskm to a maximum of 5.1mskm. 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 (3.2mskm). Under nonstationary conditions, alternative definitions of return period should be adapted. Under the GAMLSS model, the return interval of an annual peak discharge of 3.2mskm 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.

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

    Science.gov (United States)

    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.

  14. Red River flooding, short-term measures : interim report to the International Red River Basin Task Force to the International Joint Commission

    International Nuclear Information System (INIS)

    1997-12-01

    The 1997 flood of the Red River Basin was one of the worst in recorded history. The basin covers 45,000 square miles and includes portions of South Dakota, North Dakota, Minnesota and Manitoba. This report of a special task force provides an overview of the environmental impacts of the 1997 flood and recommends a series of strategies to prevent or reduce future flood damage in the Basin. For example, within Manitoba, more than 550 containers that held hazardous materials were retrieved from the Red River. The contents of the containers which included propane, heating fuel, petroleum products, fire-fighting foam, tar, alcohol, solvents, corrosive liquids, polyester resin, paint, and pesticides, made their way into the floodwaters. Estimates of the amount of fuel oil that spilled in Manitoba are not available, but some 15,000 gallons of gasoline spilled from service stations in Breckenridge, Minnesota. The precursors that lead to the severe flooding in 1997 included heavy precipitation and higher than average temperatures that created less than ideal melt conditions. Since 1989, weekly maps of snow and water in the Canadian prairies have been produced because knowledge of the spatial distribution and amount of snow cover during the winter is important for forecasting spring water supply conditions. The Task Force made 40 recommendations that should be initiated within the short term. One of the recommendations was to remove or secure hazardous materials stored in the flood plain. 3 tabs., 4 figs

  15. Estimating future flood frequency and magnitude in basins affected by glacier wastage.

    Science.gov (United States)

    2015-03-01

    We present field measurements of meteorology, hydrology and glaciers and long-term modeled projections of glacier mass balance and : stream flow informed by downscaled climate simulations. The study basins include Valdez Glacier Stream (342 km2 : ), ...

  16. Effects of livestock grazing on nutrient retention in a headwater stream of the Rio Puerco Basin

    Science.gov (United States)

    Mark A. Sewards; H. Maurice Valett

    1996-01-01

    Sediment and nutrient loss from headwater streams of sedimentary basins in the semi-arid Southwest have been attributed to both over-grazing by livestock and to climatic cycles that influence arroyo formation. Considerable effort has been directed toward the influence of livestock grazing on riparian species abundance and diversity. Less work has concentrated on the...

  17. In-vessel core debris retention through external flooding of the reactor pressure vessel. State-of-the-art report

    International Nuclear Information System (INIS)

    Heel, A.M.J.M. van.

    1995-07-01

    An overview of the state-of-the-art knowledge on the ex-vessel flooding accident management strategy for severe accidents in a NPP has been given. The feasibility has been discussed, as well as the in- and ex-vessel phenomena, which influence the structural integrity of the vessel. Finally, some computer codes with the ability to model the phenomena involved in ex-vessel flooding have been discussed. (orig./HP)

  18. In-vessel core debris retention through external flooding of the reactor pressure vessel. State-of-the-art report

    Energy Technology Data Exchange (ETDEWEB)

    Heel, A.M.J.M. van

    1995-07-01

    An overview of the state-of-the-art knowledge on the ex-vessel flooding accident management strategy for severe accidents in a NPP has been given. The feasibility has been discussed, as well as the in- and ex-vessel phenomena, which influence the structural integrity of the vessel. Finally, some computer codes with the ability to model the phenomena involved in ex-vessel flooding have been discussed. (orig./HP).

  19. Identification of spatial and temporal contributions of rainfalls to flash floods using neural network modelling: case study on the Lez basin (southern France)

    Science.gov (United States)

    Darras, T.; Borrell Estupina, V.; Kong-A-Siou, L.; Vayssade, B.; Johannet, A.; Pistre, S.

    2015-10-01

    Flash floods pose significant hazards in urbanised zones and have important implications financially and for humans alike in both the present and future due to the likelihood that global climate change will exacerbate their consequences. It is thus of crucial importance to improve the models of these phenomena especially when they occur in heterogeneous and karst basins where they are difficult to describe physically. Toward this goal, this paper applies a recent methodology (Knowledge eXtraction (KnoX) methodology) dedicated to extracting knowledge from a neural network model to better determine the contributions and time responses of several well-identified geographic zones of an aquifer. To assess the interest of this methodology, a case study was conducted in southern France: the Lez hydrosystem whose river crosses the conurbation of Montpellier (400 000 inhabitants). Rainfall contributions and time transfers were estimated and analysed in four geologically delimited zones to estimate the sensitivity of flash floods to water coming from the surface or karst. The Causse de Viols-le-Fort is shown to be the main contributor to flash floods and the delay between surface and underground flooding is estimated to be 3 h. This study will thus help operational flood warning services to better characterise critical rainfall and develop measurements to design efficient flood forecasting models. This generic method can be applied to any basin with sufficient rainfall-run-off measurements.

  20. Riesgo de anegamiento: estimaciones para la Cuenca Baja del Río Salado Flooding risk in the Salado River Basin

    Directory of Open Access Journals (Sweden)

    Pablo Mauricio Vázquez

    2009-12-01

    .571 ha eran sitios donde la recurrencia de anegamiento fue >40%, y que el 7,98% de la superficie destinada a verdeos (51.504 ha se realizaron en sitios riesgosos.It is well documented that the lower basin of the Salado River has been always exposed to frequent floods. Nevertheless, from 1986 to 2001 the cultivated surface of the Flooding Pampas increased by 69%, being this agricultural expansion mostly over lands that have been periodically affected by floods. A flooding risk analysis was carried out in order to assist with the planning and disposition of farming activities in the Flooding Pampas. For this purpose, the recurrence of precipitations was calculated over 20 meteorological stations, and linked to a by-pixel flooding frequency layer resultant from an analysis of a time-series of satellite images. Results denote that extreme events of accumulated precipitation have been registered in all seasons, being autumn and winter flooding events more prolonged than the spring and summer ones. Even though autumn and winter had similar flooding durabilities, autumn turned out to be the critical season as a result of a higher frequency of flooding events in April and May. Severe flooding could occur when precipitations exceed 150-200 mm, as precipitation accumulations of these magnitudes were related to flooded areas equivalent to 68.76% of the region (5,844,709 ha. Anthropic structures contributed to as much as 2.11% of the regional flooding, as shown by the flooding pattern of the region, being channels 12, 11 and 9, as well as the provincial highway No. 9 and the train rail from Metrovías the main impediments for the water flow. For the 2003-2004 period, we deter-mined through remote sensing techniques that 22.8% of the surface with crop production (173,571 ha corresponded to areas with a flooding recurrence higher than 40%, whereas only 7.98% of the surface with sown pastures (51,504 ha corresponded to risky areas.

  1. Quantifying changes in flooding and habitats in the Tonle Sap Lake (Cambodia) caused by water infrastructure development and climate change in the Mekong Basin.

    Science.gov (United States)

    Arias, Mauricio E; Cochrane, Thomas A; Piman, Thanapon; Kummu, Matti; Caruso, Brian S; Killeen, Timothy J

    2012-12-15

    The economic value of the Tonle Sap Lake Floodplain to Cambodia is arguably among the highest provided to a nation by a single ecosystem around the world. Nonetheless, the Mekong River Basin is changing rapidly due to accelerating water infrastructure development (hydropower, irrigation, flood control, and water supply) and climate change, bringing considerable modifications to the flood pulse of the Tonle Sap Lake in the foreseeable future. This paper presents research conducted to determine how the historical flooding regime, together with human action, influenced landscape patterns of habitats in the Tonle Sap Lake, and how these habitats might shift as a result of hydrological changes. Maps of water depth, annual flood duration, and flood frequency were created for recent historical hydrological conditions and for simulated future scenarios of water infrastructure development and climate change. Relationships were then established between the historical flood maps and land cover, and these were subsequently applied to assess potential changes to habitat cover in future decades. Five habitat groups were clearly distinguishable based on flood regime, physiognomic patterns, and human activity: (1) Open water, flooded for 12 months in an average hydrological year; (2) Gallery forest, with flood duration of 9 months annually; (3) Seasonally flooded habitats, flooded 5-8 months and dominated by shrublands and grasslands; (4) transitional habitats, flooded 1-5 months and dominated by abandoned agricultural fields, receding rice/floating rice, and lowland grasslands; and (5) Rainfed habitats, flooded up to 1 month and consisting mainly of wet season rice fields and village crops. It was found that water infrastructure development could increase the area of open water (+18 to +21%) and the area of rainfed habitats (+10 to +14%), while reducing the area covered with seasonally flooded habitats (-13 to -22%) and gallery forest (-75 to -83%). Habitat cover shifts as a

  2. Development of Flood Forecasting Using Statistical Method in Four River Basins in Terengganu, Malaysia

    Science.gov (United States)

    Noor, M. S. F. M.; Sidek, L. M.; Basri, H.; Husni, M. M. M.; Jaafar, A. S.; Kamaluddin, M. H.; Majid, W. H. A. W. A.; Mohammad, A. H.; Osman, S.

    2016-03-01

    One of the critical regions in Malaysia is Terengganu which is located at east coast of Peninsular Malaysia. In Terengganu, flood is experienced regularly because of attributed topography and climate including northeast monsoon. Moreover, rainfall is with high intensity during the November to February in Terengganu as forcing factor to produce of flood. In this study, main objectives are water stage forecasting and deriving the related equations based on least squared method. For this study, it is used two methods which called inclusion of residual (Method A) and non-inclusion residual (Method B) respectively. Result depicts that Method B outperformed to forecast the water stage at selected case studies (Besut, Dungun, Kemaman, Terengganu).

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

    Science.gov (United States)

    Ahamed, A.; Bolten, J. D.

    2016-12-01

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

  4. The pathways for the most important hazardous substances in the Rhine basin (during floods)

    Energy Technology Data Exchange (ETDEWEB)

    Braun, M. [Internationale Kommission zum Schutze des Rheins gegen Verunreinigung, Koblenz (Germany)

    2001-07-01

    Target values defined as scientifically substantiated tools for assessing the chemical and physical water and sediment quality are used for appraising the effects of emission reduction measures on the recovery of the Rhine ecosystem (including its flood plains). Target values are no legally binding threshold or standard values. They are derived for each parameter of the following assets meriting protection: aquatic communities, drinking water production and suspended matter/sediments. (orig.)

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

    Science.gov (United States)

    Fredj, Erick; Givati, Amir

    2015-04-01

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

  6. Reconnaissance Waccamaw River Basin North Carolina and South Carolina. Flood Control and Related Purposes.

    Science.gov (United States)

    1981-09-01

    0.80 0.80 0.84 LAND USE The Waccamaw River Bdsin is an agricultural area. The principal crops grown are tobacco, corn, cotton, soybeans , sweet potatoes...non- farm use. Of the 3,200 acres of cultivated land, 2,470 acres have flooding and drainage problems. Corn and soybeans are the principle crops in... hedge - rows, fields, and meadows. Diverse habitats, large open spaces, and unimpaired mobility are necessary to the survival of large birds of prey

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

    Directory of Open Access Journals (Sweden)

    Hao Zhou

    2017-10-01

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

  8. Flood forecasting for the upper reach of the Red River Basin, North ...

    African Journals Online (AJOL)

    Vu Quang station on the Lo River. Located on the upper reach of the Red River basin, these stations do not have any tidal effect. As such, no tidal data are needed for forecasting purposes . Multiple linear regression (MLR) model. The general forecasting equation based on MLR can be written as follows: H, =A+Iaj Hr- I +.

  9. Mapping spatio-temporal flood inundation dynamics at large river basin scale using time-series flow data and MODIS imagery

    Science.gov (United States)

    Huang, Chang; Chen, Yun; Wu, Jianping

    2014-02-01

    Flood inundation is crucial to the survival and prosperity of flora and fauna communities in floodplain and wetland ecosystems. This study tried to map flood inundation characteristics in the Murray-Darling Basin, Australia, utilizing hydrological and remotely sensed data. It integrated river flow time series and Moderate Resolution Imaging Spectroradiometer (MODIS) images to map inundation dynamics over the study area on both temporal and spatial dimensions. Flow data were analyzed to derive flow peaks and Annual Exceedance Probabilities (AEPs) using the annual flood series method. The peaks were linked with MODIS images for inundation detection. Ten annual maximum inundation maps were generated for water years 2001-2010, which were then overlaid to derive an inundation frequency map. AEPs were also combined with the annual maximum inundation maps to derive an inundation probability map. The resultant maps revealed spatial and temporal patterns of flood inundation in the basin, which will benefit ecological and environmental studies when considering response of floodplain and wetland ecosystems to flood inundation.

  10. Estimating flood magnitude and frequency at gaged and ungaged sites on streams in Alaska and conterminous basins in Canada, based on data through water year 2012

    Science.gov (United States)

    Curran, Janet H.; Barth, Nancy A.; Veilleux, Andrea G.; Ourso, Robert T.

    2016-03-16

    Estimates of the magnitude and frequency of floods are needed across Alaska for engineering design of transportation and water-conveyance structures, flood-insurance studies, flood-plain management, and other water-resource purposes. This report updates methods for estimating flood magnitude and frequency in Alaska and conterminous basins in Canada. Annual peak-flow data through water year 2012 were compiled from 387 streamgages on unregulated streams with at least 10 years of record. Flood-frequency estimates were computed for each streamgage using the Expected Moments Algorithm to fit a Pearson Type III distribution to the logarithms of annual peak flows. A multiple Grubbs-Beck test was used to identify potentially influential low floods in the time series of peak flows for censoring in the flood frequency analysis.For two new regional skew areas, flood-frequency estimates using station skew were computed for stations with at least 25 years of record for use in a Bayesian least-squares regression analysis to determine a regional skew value. The consideration of basin characteristics as explanatory variables for regional skew resulted in improvements in precision too small to warrant the additional model complexity, and a constant model was adopted. Regional Skew Area 1 in eastern-central Alaska had a regional skew of 0.54 and an average variance of prediction of 0.45, corresponding to an effective record length of 22 years. Regional Skew Area 2, encompassing coastal areas bordering the Gulf of Alaska, had a regional skew of 0.18 and an average variance of prediction of 0.12, corresponding to an effective record length of 59 years. Station flood-frequency estimates for study sites in regional skew areas were then recomputed using a weighted skew incorporating the station skew and regional skew. In a new regional skew exclusion area outside the regional skew areas, the density of long-record streamgages was too sparse for regional analysis and station skew was used

  11. Assessing the potential of satellite-based precipitation estimates for flood frequency analysis in ungauged or poorly gauged tributaries of China's Yangtze River basin

    Science.gov (United States)

    Gao, Zhen; Long, Di; Tang, Guoqiang; Zeng, Chao; Huang, Jiesheng; Hong, Yang

    2017-07-01

    Flood frequency analysis (FFA) is critical for water resources engineering projects, particularly the design of hydraulic structures such as dams and reservoirs. However, it is often difficult to implement FFA in ungauged or poorly gauged basins because of the lack of consistent and long-term records of streamflow observations. The objective of this study was to evaluate the utility of satellite-based precipitation estimates for performing FFA in two presumably ungauged tributaries, the Jialing and Tuojiang Rivers, of the upper Yangtze River. Annual peak flow series were simulated using the Coupled Routing and Excess STorage (CREST) hydrologic model. Flood frequency was estimated by fitting the Pearson type III distribution of both observed and modeled streamflow with historic floods. Comparison of satellite-based precipitation products with a ground-based daily precipitation dataset for the period 2002-2014 reveals that 3B42V7 outperformed 3B42RT. The 3B42V7 product also shows consistent reliability in streamflow simulation and FFA (e.g., relative errors -20%-5% in the Jialing River). The results also indicate that complex terrain, drainage area, and reservoir construction are important factors that impact hydrologic model performance. The larger basin (156,736 km2) is more likely to produce satisfactory results than the small basin (19,613 km2) under similar circumstances (e.g., Jialing/Tuojiang calibrated by 3B42V7 for the calibration period: NSCE = 0.71/0.56). Using the same calibrated parameter sets from the entire Jialing River basin, the 3B42V7/3B42RT-driven hydrologic model performs better for two tributaries of the Jialing River (e.g., for the calibration period, NSCE = 0.71/0.60 in the Qujiang River basin and 0.54/0.38 in the Fujiang River basin) than for the upper mainstem of the Jialing River (NSCE = 0.34/0.32), which has more cascaded reservoirs with all these tributaries treated as ungauged basins for model validation. Overall, this study underscores

  12. Flood risk assessment through 1D/2D couple HEC-RAS hydrodynamic modeling- A case study of Surat City, Lower Tapi Basin, India

    Science.gov (United States)

    Patel, Dhruvesh; Ramirez, Jorge; Srivastava, Prashant; Bray, Michaela; Han, Dawei

    2017-04-01

    Surat, known as the diamond city of Gujart is situated 100 km downstream of Ukai dam and near the mouth of river Tapi and affected by the flood at every alternate year. The city experienced catastrophic floods in 1933, 1959, 1968, 1970, 1994, 1998 and 2006. It is estimated that a single flood event during August 6-12, 2006 in Surat and Hazira twin-city, caused heavy damages, resulted in the death of 300 people and property damage worth € 289 million. The peak discharge of 25768 m3 s-1 release from Ukai dam was responsible for the disastrous flood in Surat city. To identifylow lying areas prone to inundation and reduce the uncertainty in flood mitigation measures, HEC-RAS based 1D/2D Couple hydrodynamic modeling is carried out for Surat city. Release from the Ukai dam and tidal level of the sea are considered for upstream and downstream boundary condition. 299 surveyed cross-sections have been considered for 1D modeling, whereas a topographic map at 0.5 m contour interval was used to produce a 5 m grid and SRTM (30 & 90 m) grid has been considered for Suart and Lower Tapi Basin (LTB). Flow is simulated under unsteady conditions, calibrated for the year 1998 and validated for the year 2006. The simulated result shows that the 9th August 18.00 hr was the worst day for Surat city and maximum 75-77 % area was under inundation. Most of the flooded area experienced 0.25 m/s water velocity with the duration of 90 hr. Due to low velocity and high duration of the flood, a low lying area within the west zone and south-west zone of the city was badly affected by the flood, whereas the south zone and south-east zone was least. Simulated results show good correlation when compared with an observed flood level map. The simulated results will be helpful to improve the flood resilience strategy at Surat city and reduce the uncertainty for flood inundation mapping for future dam releases. The present case study shows the applicability of 1D/2D coupled hydrodynamic modeling for

  13. Application of Jason-2/3 Altimetry for Virtual Gauging and Flood Forecasting in Mekong Basin

    Science.gov (United States)

    Lee, H.; Hossain, F.; Okeowo, M. A.; Nguyen, L. D.; Bui, D. D.; Chang, C. H.

    2016-12-01

    Vietnam suffers from both flood and drought during the rainy and dry seasons, respectively, due to its highly varying surface water resources. However, the National Center for Water Resources Planning and Investigation (NAWAPI) states that only 7 surface water monitoring stations have been constructed in Central and Highland Central regions with 100 station planned to be constructed by 2030 throughout Vietnam. For the Mekong Delta (MD), the Mekong River Commission (MRC) provides 7-day river level forecasting, but only at the two gauge stations located near the border between Cambodia and Vietnam (http://ffw.mrcmekong.org/south.htm). In order to help stakeholder agencies monitor upstream processes in the rivers and manage their impacts on the agricultural sector and densely populated delta cities, we, first of all, construct the so-called virtual stations throughout the entire Mekong River using the fully automated river level extraction tool with Jason-2/3 Geophysical Research Record (GDR) data. Then, we discuss the potentials and challenges of river level forecasting using Jason-2/3 Interim GDR (IGDR) data, which has 1 - 2 days of latency, over the Mekong River. Finally, based on our analyses, we propose a forecasting system for the Mekong River by drawing from our experience in operationalizing Jason-2 altimetry for Bangladesh flood forecasting.

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

    Science.gov (United States)

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

    2013-05-01

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

  15. Nutrients levels in paddy soils and flood waters from Tagus-Sado basin: the impact of farming system

    Science.gov (United States)

    Santos, Erika S.; Abreu, Maria Manuela; Magalhães, Maria Clara; Viegas, Wanda; Amâncio, Sara; Cordovil, Cláudia

    2017-04-01

    Application of fertilizers for crops can contribute to nutrients surplus, namely nitrogen, in both groundwater and surface waters resulting in serious environmental problems. The impacts on water quality due to fertilizers are related to land management. In paddy fields using high amounts of water, the nutrient dynamic knowledge is essential to evaluate the impact of farming system. The aims of this study were to evaluate: i)nutrients levels in soils and floodwaters from rice cultivation in Tagus-Sado basin (Portugal); ii)the effect, under controlled conditions, of different irrigation techniques on nutrient enrichment of floodwaters from rice cultivation. Composite samples (n=24) of paddy soils (0-15 cm) and floodwaters were collected, during rice flooding period. In the field, pH and electrical conductivity (EC) were determined in waters. Soil pH, concentrations of Corganic, NPK and nutrients (Ca, Cu, Fe, Mg, Mn, Zn) in soils and floodwaters (nitrites, nitrates, phosphates) were determined. A mesocosm assay was performed in lysimeters with a paddy soil (pH: 5.6; g/kg- Ntotal: 2.0, Pextractable: 0.04, Kextractable: 0.6, Corganic: 35.5) and different irrigation techniques (n=3): a)flood; b)four floods per day (great water renewal); c)flood until rice flowering and then a normal superficial irrigation. Rice cultivation was done by transplant as in the field. Irrigation water come from a well. Same chemical characterization than in field assay were determined in floodwater and irrigation water. In field conditions, paddy soils had values of pH between 5.1 and 8.1 and a great fertility range (g/kg; Ntotal: 0.4‒2.2; Pextractable: 0.01‒0.2; Kextractable: 0.04‒0.7; Corganic: 6.5‒37.9). Total soil concentrations of Cu, Fe, and Zn in soils were in same range and below maximum admissible values for agriculture. Total soil concentrations of Ca, Mg and Mn, showed higher heterogeneity (g/kg; 1.2‒19.3, 7.6‒34.2 and 0.2‒1.5 respectively). Floodwaters presented pH

  16. Flood risk analysis and adaptive strategy in context of uncertainties: a case study of Nhieu Loc Thi Nghe Basin, Ho Chi Minh City

    Science.gov (United States)

    Ho, Long-Phi; Chau, Nguyen-Xuan-Quang; Nguyen, Hong-Quan

    2013-04-01

    The Nhieu Loc - Thi Nghe basin is the most important administrative and business area of Ho Chi Minh City. Due to system complexity of the basin such as the increasing trend of rainfall intensity, (tidal) water level and land subsidence, the simulation of hydrological, hydraulic variables for flooding prediction seems rather not adequate in practical projects. The basin is still highly vulnerable despite of multi-million USD investment for urban drainage improvement projects since the last decade. In this paper, an integrated system analysis in both spatial and temporal aspects based on statistical, GIS and modelling approaches has been conducted in order to: (1) Analyse risks before and after projects, (2) Foresee water-related risk under uncertainties of unfavourable driving factors and (3) Develop a sustainable flood risk management strategy for the basin. The results show that given the framework of risk analysis and adaptive strategy, certain urban developing plans in the basin must be carefully revised and/or checked in order to reduce the highly unexpected loss in the future

  17. An initial abstraction and constant loss model, and methods for estimating unit hydrographs, peak streamflows, and flood volumes for urban basins in Missouri

    Science.gov (United States)

    Huizinga, Richard J.

    2014-01-01

    Streamflow data, basin characteristics, and rainfall data from 39 streamflow-gaging stations for urban areas in and adjacent to Missouri were used by the U.S. Geological Survey in cooperation with the Metropolitan Sewer District of St. Louis to develop an initial abstraction and constant loss model (a time-distributed basin-loss model) and a gamma unit hydrograph (GUH) for urban areas in Missouri. Study-specific methods to determine peak streamflow and flood volume for a given rainfall event also were developed.

  18. Effects of flood control alternatives on fish and wildlife resources of the Malheur-Harney lakes basin

    Science.gov (United States)

    Hamilton, David B.; Auble, Gregor T.; Ellison, Richard A.; Roelle, James E.

    1985-01-01

    Malheur Lake is the largest freshwater marsh in the western contiguous United States and is one of the main management units of the Malheur National Wildlife Refuge in southeastern Oregon. The marsh provides excellent waterfowl production habitat as well as vital migration habitats for birds in the Pacific flyway. Water shortages have typically been a problem in this semiarid area; however, record snowfalls and cool summers have recently caused Malheur Lake to rise to its highest level in recorded history. This has resulted in the loss of approximately 57,000 acres of important wildlife habitat as well as extensive flooding of local ranches, roads, and railroad lines. Because of the importance of the Refuge, any water management plan for the Malheur-Harney Lakes Basin needs to consider the impact of management alternatives on the hydrology of Malheur Lake. The facilitated modeling workshop described in this report was conducted January 14-18, 1985, under the joint sponsorship of the Portland Ecological Services Field Office and the Malheur National Wildlife Refuge, Region 1, U.S. Fish and Wildlife Service (FWS). The Portland Field Office is responsible for FWS reporting requirements on Federal water resource projects while the Refuge staff has management responsibility for much of the land affected by high water levels in the Malheur-Harney Lakes Basin. The primary objective of the workshop was to begin gathering and analyzing information concerning potential fish and wildlife impacts, needs, and opportunities associated with proposed U.S. Army Corps of Engineers (COE) flood control alternatives for Malheur Lake. The workshop was structured around the formulation of a computer model that would simulate the hydrologic effects of the various alternatives and any concommitant changes in vegetation communities and wildlife use patterns. The simulation model is composed of three connected submodels. The Hydrology submodel calculates changes in lake volume, elevation

  19. Using remote sensing time series to model the impact of changing flooding regimes on riparian vegetation in Australia's most important river basin

    Science.gov (United States)

    Broich, M.; Tulbure, M. G.; Verbesselt, J.; Xin, Q.

    2016-12-01

    Australia is a continent subject to high rainfall variability, which has major influences on runoff and vegetation dynamics. However, the resulting spatial-temporal pattern of flooding and its influence on riparian vegetation has not been quantified in a spatially explicit way. Here we focused on the floodplains of the entire Murray-Darling Basin (MDB), an area that covers over 1M km2, as a case study. The MDB is the country's primary agricultural area with scarce water resources subject to competing demands and impacted by climate change and more recently by the Millennium Drought (1999-2009). Riparian vegetation in the MDB floodplain suffered extensive decline providing a dramatic degradation of riparian vegetation. We quantified the spatial-temporal impact of rainfall, temperature and flooding patters on vegetation dynamics at the subcontinental to local scales and across inter to intra-annual time scales based on three decades of Landsat (25k images), Bureau of Meteorology data and one decade of MODIS data. Vegetation response varied in space and time and with vegetation types, densities and location relative to areas frequently flooded. Vegetation degradation trends were observed over riparian forests and woodlands in areas where flooding regimes have changed to less frequent and smaller inundation extents. Conversely, herbaceous vegetation phenology followed primarily a `boom' and `bust' cycle, related to inter-annual rainfall variability. Spatial patters of vegetation degradation changed along the N-S rainfall gradient but flooding regimes and vegetation degradation patterns also varied at finer scale, highlighting the importance of a spatially explicit, internally consistent analysis and setting the stage for investigating further cross-scale relationships. Results are of interest for land and water management decisions. The approach developed here can be applied to other areas globally such as the Nile river basin and Okavango River delta in Africa or the

  20. Response of Riparian Vegetation in Australia's Largest River Basin to Inter and Intra-Annual Climate Variability and Flooding as Quantified with Landsat and MODIS

    Science.gov (United States)

    Broich, M.; Tulbure, M. G.

    2015-12-01

    Australia is a continent subject to high rainfall variability, which has major influences on runoff and vegetation dynamics. However, the resulting spatial-temporal pattern of flooding and its influence on riparian vegetation has not been quantified in a spatially explicit way. Here we focused on the floodplains of the entire Murray-Darling Basin (MDB), an area that covers over 1M km^2, as a case study. The MDB is the country's primary agricultural area with scarce water resources subject to competing demands and impacted by climate change and more recently by the Millennium Drought (1999-2009). Riparian vegetation in the MDB floodplain suffered extensive decline providing a dramatic degradation of riparian vegetation. We quantified the spatial-temporal impact of rainfall, temperature and flooding patters on vegetation dynamics at the sub- continental to local scales and across inter to intra-annual time scales based on three decades of Landsat (25k images), Bureau of Meteorology data and one decade of MODIS data. Vegetation response varied in space and time and with vegetation types, densities and location relative to areas frequently flooded. Vegetation degradation trends were observed over riparian forests and woodlands in areas where flooding regimes have changed to less frequent and smaller inundation extents. Conversely, herbaceous vegetation phenology followed primarily a 'boom' and 'bust' cycle, related to inter-annual rainfall variability. Spatial patters of vegetation degradation changed along the N-S rainfall gradient but flooding regimes and vegetation degradation patterns also varied at finer scale, highlighting the importance of a spatially explicit, internally consistent analysis and setting the stage for investigating further cross-scale relationships. Results are of interest for land and water management decisions. The approach developed here can be applied to other areas globally such as the Nile river basin and Okavango River delta in Africa or

  1. Response of Riparian Vegetation in AUSTRALIA"S Largest River Basin to Inter and Intra-Annual Climate Variability and Flooding as Quantified with Landsat and Modis

    Science.gov (United States)

    Broich, M.; Tulbure, M. G.

    2016-06-01

    Australia is a continent subject to high rainfall variability, which has major influences on runoff and vegetation dynamics. However, the resulting spatial-temporal pattern of flooding and its influence on riparian vegetation has not been quantified in a spatially explicit way. Here we focused on the floodplains of the entire Murray-Darling Basin (MDB), an area that covers over 1M km2, as a case study. The MDB is the country's primary agricultural area with scarce water resources subject to competing demands and impacted by climate change and more recently by the Millennium Drought (1999-2009). Riparian vegetation in the MDB floodplain suffered extensive decline providing a dramatic degradation of riparian vegetation. We quantified the spatial-temporal impact of rainfall, temperature and flooding patters on vegetation dynamics at the subcontinental to local scales and across inter to intra-annual time scales based on three decades of Landsat (25k images), Bureau of Meteorology data and one decade of MODIS data. Vegetation response varied in space and time and with vegetation types, densities and location relative to areas frequently flooded. Vegetation degradation trends were observed over riparian forests and woodlands in areas where flooding regimes have changed to less frequent and smaller inundation extents. Conversely, herbaceous vegetation phenology followed primarily a `boom' and `bust' cycle, related to inter-annual rainfall variability. Spatial patters of vegetation degradation changed along the N-S rainfall gradient but flooding regimes and vegetation degradation patterns also varied at finer scale, highlighting the importance of a spatially explicit, internally consistent analysis and setting the stage for investigating further cross-scale relationships. Results are of interest for land and water management decisions. The approach developed here can be applied to other areas globally such as the Nile river basin and Okavango River delta in Africa or the

  2. RESPONSE OF RIPARIAN VEGETATION IN AUSTRALIA"S LARGEST RIVER BASIN TO INTER AND INTRA-ANNUAL CLIMATE VARIABILITY AND FLOODING AS QUANTIFIED WITH LANDSAT AND MODIS

    Directory of Open Access Journals (Sweden)

    M. Broich

    2016-06-01

    Full Text Available Australia is a continent subject to high rainfall variability, which has major influences on runoff and vegetation dynamics. However, the resulting spatial-temporal pattern of flooding and its influence on riparian vegetation has not been quantified in a spatially explicit way. Here we focused on the floodplains of the entire Murray-Darling Basin (MDB, an area that covers over 1M km2, as a case study. The MDB is the country’s primary agricultural area with scarce water resources subject to competing demands and impacted by climate change and more recently by the Millennium Drought (1999–2009. Riparian vegetation in the MDB floodplain suffered extensive decline providing a dramatic degradation of riparian vegetation. We quantified the spatial-temporal impact of rainfall, temperature and flooding patters on vegetation dynamics at the subcontinental to local scales and across inter to intra-annual time scales based on three decades of Landsat (25k images, Bureau of Meteorology data and one decade of MODIS data. Vegetation response varied in space and time and with vegetation types, densities and location relative to areas frequently flooded. Vegetation degradation trends were observed over riparian forests and woodlands in areas where flooding regimes have changed to less frequent and smaller inundation extents. Conversely, herbaceous vegetation phenology followed primarily a ‘boom’ and ‘bust’ cycle, related to inter-annual rainfall variability. Spatial patters of vegetation degradation changed along the N-S rainfall gradient but flooding regimes and vegetation degradation patterns also varied at finer scale, highlighting the importance of a spatially explicit, internally consistent analysis and setting the stage for investigating further cross-scale relationships. Results are of interest for land and water management decisions. The approach developed here can be applied to other areas globally such as the Nile river basin and

  3. Rain gauge network design for flood forecasting using multi-criteria decision analysis and clustering techniques in lower Mahanadi river basin, India

    Directory of Open Access Journals (Sweden)

    Anil Kumar Kar

    2015-09-01

    New hydrological insights for the region: This study establishes different possible key RG networks using Hall’s method, analytical hierarchical process (AHP, self organization map (SOM and hierarchical clustering (HC using the characteristics of each rain gauge occupied Thiessen polygon area. Efficiency of the key networks is tested by artificial neural network (ANN, Fuzzy and NAM rainfall-runoff models. Furthermore, flood forecasting has been carried out using the three most effective RG networks which uses only 7 RGs instead of 14 gauges established in the Kantamal sub-catchment, Mahanadi basin. The Fuzzy logic applied on the key RG network derived using AHP has shown the best result for flood forecasting with efficiency of 82.74% for 1-day lead period. This study demonstrates the design procedure of key RG network for effective flood forecasting particularly when there is difficulty in gathering the information from all RGs.

  4. Wetland vegetation and nutrient retention in Nakivubo and Kirinya wetlands in the Lake Victoria basin of Uganda

    Science.gov (United States)

    Mugisha, P.; Kansiime, F.; Mucunguzi, P.; Kateyo, E.

    Wetlands form an important part of the catchment area of the African Great Lakes and protect water resources therein. One of the most important functions is the retention of nutrients from the inflowing water from the catchment, by wetland plants which store them in their phytomass. An assessment of the capacity in storing nutrients by dominant plants ( Cyeprus papyrus, Miscanthus violaceus, Phragmites mauritianus and Colocasia C. esculenta), of Nakivubo and Kirinya wetlands at the shores of Lake Victoria in Uganda, was studied through the determination of phytomass production and nutrient concentration in the plant parts at different stages of growth. The above ground phytomass production increased rapidly during the exponential growth for C. papyrus and P. mauritianus. In all the dominant plants, nitrogen concentration was highest in juvenile plants and decreased with increasing age. The most pronounced nitrogen level occurred in the young umbels of C. papyrus during the first month of growth with total nitrogen content of 1.95% DW which dropped to 0.62% DW after the fifth month in Nakivubo wetland. Corms (tubers) of yams had the highest nitrogen content in Kirinya and Nakivubo wetlands exhibiting respective values of 4.8% DW and 3.7% DW. There is a close relationship between nutrient content and increase in phytomass. In Nakivubo and Kirinya wetlands, the rapid increase in phytomass during the third and fourth month corresponded with high nutrient levels. Since plants store significant amounts of nitrogen during their growth, periodic harvesting of above ground plant parts can remove significant amounts of nutrients (during the first five months of growth) from the wastewater flowing into the two wetlands. Wetland plant species with high phytomass productivity and well developed root systems and ability to withstand flooding are the best in nutrient removal.

  5. Flood Simulations and Uncertainty Analysis for the Pearl River Basin Using the Coupled Land Surface and Hydrological Model System

    Directory of Open Access Journals (Sweden)

    Yongnan Zhu

    2017-06-01

    Full Text Available The performances of hydrological simulations for the Pearl River Basin in China were analysed using the Coupled Land Surface and Hydrological Model System (CLHMS. Three datasets, including East Asia (EA, high-resolution gauge satellite-merged China Merged Precipitation Analysis (CMPA-Daily, and the Asian Precipitation Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE daily precipitation were used to drive the CLHMS model to simulate daily hydrological processes from 1998 to 2006. The results indicate that the precipitation data was the most important source of uncertainty in the hydrological simulation. The simulated streamflow driven by the CMPA-Daily agreed well with observations, with a Pearson correlation coefficient (PMC greater than 0.70 and an index of agreement (IOA similarity coefficient greater than 0.82 at Liuzhou, Shijiao, and Wuzhou Stations. Comparison of the Nash-Sutcliffe efficiency coefficient (NSE shows that the peak flow simulation ability of CLHMS driven with the CMPA-Daily rainfall is relatively superior to that with the EA and APHRODITE datasets. The simulation results for the high-flow periods in 1998 and 2005 indicate that the CLHMS is promising for its future application in the flood simulation and prediction.

  6. Impacts of adaptive flood management strategies on the Socio-Hydrological system in Ganges - Brahmaputra river basin, Bangladesh

    Science.gov (United States)

    Sung, K.; Jeong, H.; Sangwan, N.; Yu, D. J.

    2017-12-01

    Human societies have tried to prevent floods by building robust infrastructure such as levees or dams. However, some scholars raise a doubt to this approach because of a lack of adaptiveness to environmental and societal changes in a long-term. Thus, a growing number of studies now suggest adopting new strategies in flood management to reinforce an adapt capacity to the long-term flood risk. This study addresses this issue by developing a conceptual mathematical model exploring how flood management strategies effect to the dynamics human-flood interaction, ultimately the flood resilience in a long-term. Especially, our model is motivated by the community-based flood protection system in southwest coastal area in Bangladesh. We developed several conceptual flood management strategies and investigated the interplay between those strategies and community's capacity to cope with floods. We additionally analyzed how external disturbances (sea level rise, water tide level change, and outside economic development) alter the adaptive capacity to flood risks. The results of this study reveal that the conventional flood management has potential vulnerabilities as external disturbances increase. Our results also highlight the needs of the adaptive strategy as a new paradigm in flood management which is able to feedback to the social and hydrological conditions. These findings provide insights on the resilience-based, adaptive strategies which can build flood resilience under global change.

  7. Effects of land-use changes and stormflow-detention basins on flooding and nonpoint-source pollution, in Irondequoit Creek basin, Monroe and Ontario counties, New York--application of a precipitation-runoff model

    Science.gov (United States)

    Coon, William F.; Johnson, Mark S.

    2005-01-01

    Urbanization of the 150-square-mile Irondequoit Creek basin in Monroe and Ontario Counties, N.Y., continues to spread southward and eastward from the City of Rochester, on the shore of Lake Ontario. Conversion of forested land to other uses over the past 40 years has increased to the extent that more than 50 percent of the basin is now developed. This expansion has increased flooding and impaired stream-water quality in the northern (downstream) half of the basin. A precipitation-runoff model of the Irondequoit Creek basin was developed with the model code HSPF (Hydrological Simulation Program--FORTRAN) to simulate the effects of land-use changes and stormflow-detention basins on flooding and nonpoint-source pollution on the basin. Model performance was evaluated through a combination of graphical comparisons and statistical tests, and indicated 'very good' agreement (mean error less than 10 percent) between observed and simulated daily and monthly streamflows, between observed and simulated monthly water temperatures, and between observed total suspended solids loads and simulated sediment loads. Agreement between monthly observed and simulated nutrient loads was 'very good' (mean error less than 15 percent) or 'good' (mean error between 15 and 25 percent). Results of model simulations indicated that peak flows and loads of sediment and total phosphorus would increase in a rural subbasin, where 10 percent of the basin was converted from forest and grassland to pervious and impervious developed areas. Subsequent simulation of a stormflow-detention basin at the mouth of this subbasin indicated that peak flows and constituent loads would decrease below those that were generated by the land-use-change scenario, and, in some cases, below those that were simulated by the original land-use scenario. Other results from model simulations of peak flows over a 30-year period (1970-2000), with and without simulation of 50-percent flow reductions at one existing and nine

  8. Towards an integrated flood management approach to address trade-offs between ecosystem services: Insights from the Dutch and German Rhine, Hungarian Tisza, and Chinese Yangtze basins

    Science.gov (United States)

    Halbe, Johannes; Knüppe, Kathrin; Knieper, Christian; Pahl-Wostl, Claudia

    2018-04-01

    The utilization of ecosystem services in flood management is challenged by the complexity of human-nature interactions and practical implementation barriers towards more ecosystem-based solutions, such as riverine urban areas or technical infrastructure. This paper analyses how flood management has dealt with trade-offs between ecosystem services and practical constrains towards more ecosystem-based solutions. To this end, we study the evolution of flood management in four case studies in the Dutch and German Rhine, the Hungarian Tisza, and the Chinese Yangtze basins during the last decades, focusing on the development and implementation of institutions and their link to ecosystem services. The complexity of human-nature interactions is addressed by exploring the impacts on ecosystem services through the lens of three management paradigms: (1) the control paradigm, (2) the ecosystem-based paradigm, and (3) the stakeholder involvement paradigm. Case study data from expert interviews and a literature search were structured using a database approach prior to qualitative interpretation. Results show the growing importance of the ecosystem-based and stakeholder involvement paradigms which has led to the consideration of a range of regulating and cultural ecosystem services that had previously been neglected. We detected a trend in flood management practice towards the combination of the different paradigms under the umbrella of integrated flood management, which aims at finding the most suitable solution depending on the respective regional conditions.

  9. Soil Water Retention Curve

    Science.gov (United States)

    Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.

    2016-12-01

    Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first

  10. Regional skew for California, and flood frequency for selected sites in the Sacramento-San Joaquin River Basin, based on data through water year 2006

    Science.gov (United States)

    Parrett, Charles; Veilleux, Andrea; Stedinger, J.R.; Barth, N.A.; Knifong, Donna L.; Ferris, J.C.

    2011-01-01

    Improved flood-frequency information is important throughout California in general and in the Sacramento-San Joaquin River Basin in particular, because of an extensive network of flood-control levees and the risk of catastrophic flooding. A key first step in updating flood-frequency information is determining regional skew. A Bayesian generalized least squares (GLS) regression method was used to derive a regional-skew model based on annual peak-discharge data for 158 long-term (30 or more years of record) stations throughout most of California. The desert areas in southeastern California had too few long-term stations to reliably determine regional skew for that hydrologically distinct region; therefore, the desert areas were excluded from the regional skew analysis for California. Of the 158 long-term stations used to determine regional skew, 145 have minimally regulated annual-peak discharges, and 13 stations are dam sites for which unregulated peak discharges were estimated from unregulated daily maximum discharge data furnished by the U.S. Army Corp of Engineers. Station skew was determined by using an expected moments algorithm (EMA) program for fitting the Pearson Type 3 flood-frequency distribution to the logarithms of annual peak-discharge data. The Bayesian GLS regression method previously developed was modified because of the large cross correlations among concurrent recorded peak discharges in California and the use of censored data and historical flood information with the new expected moments algorithm. In particular, to properly account for these cross-correlation problems and develop a suitable regression model and regression diagnostics, a combination of Bayesian weighted least squares and generalized least squares regression was adopted. This new methodology identified a nonlinear function relating regional skew to mean basin elevation. The regional skew values ranged from -0.62 for a mean basin elevation of zero to 0.61 for a mean basin elevation

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

    Science.gov (United States)

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

    2017-04-01

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

  12. Gravitational Effects of Flooding and Filling of Impact Basins on Mars

    Science.gov (United States)

    Smith, David E.; Zuber, Maria T.

    2004-01-01

    The presence of large impact basins and the low northern plains that might have contained ice or liquid water at an earlier stage of Mars evolution suggests that the global gravity field could have been different in the distant past than it is today. In addition, any significant change in the distribution of mass affects the moments of inertia and consequently and could conceivably change the position of the pole and the length of day. Similar effects could have been produced by large erosional processes, such as the removal of crustal material from the Arabia Terra region and subsequent re-deposition in the Chryse region of the northern plains. We have endeavored to estimate the magnitudes of material that might have been involved in these processes and their possible effect on the gravity and dynamics of Mars. We have used present-day topography and gravity field as a starting point, recognizing that both the result of the processes that we are trying to study rather than the state at the times of interest.

  13. Midwest Flood of 2008: Lake Michigan Basin-Wide Summer Plankton Bloom is not due to Nutrient Injection

    Science.gov (United States)

    Cuhel, R. L.; Aguilar, C.; Balch, B.

    2008-12-01

    Major Midwestern US flooding occurred in June of 2008 following over 30cm of rainfall in a 4-day period. Tributaries to Lake Michigan swelled, with outflow from the Milwaukee River increasing 30-fold from long-term means of 8.5 m3/s to over 250 m3/s. Flood stage was sustained for 8 days and dampened over a protracted 30-day period. A series of inshore, transect, and mid-lake cruises established the presence of unseasonally strong gradients in surface phytoplankton biomass moving progressively offshore, to ultimately influence at least half of the 150 km-wide Lake Michigan basin. Remote sensing of chlorophyll (chl) and the diffuse attenuation coefficient (at 490nm) documented the existence of blooms offshore of each major river on both sides of the lake persisting into mid-July, and then disappearing from surface waters, not visible to space-based satellite sensors. Profiles detailed deep chlorophyll maxima that were distinct from previous years. Surface transects in 2007 yielded typical summer chl of quagga mussel-infested shallower reef zone. Offshore transects displayed high chl in the upper 5m only a few days after the onset of high flow. Unseasonably high phytoplankton population densities progressed with time and distance offshore in a manner suggestive of advection of a surface lens across the well-stratified lake. As the lens progressed offshore, populations continued to grow, appearing as a band of high chl extending across the lake. After 2 weeks, inshore areas had substantially lower surface biomass than those offshore, reflecting settling of denser cells during a long period of relatively calm weather. Development of deep chlorophyll maxima (DCM) at 25-40m followed the decrease of surface populations at all locations deeper than 50m. High satellite- derived diffuse attenuation coefficients also reflected the presence of dense algal populations in the upper water column. 1% PAR penetration reached to only 25m, substantially short of the 35-40m

  14. Land Use Changes Analysis for Kelantan Basin Using Spatial Matrix Technique “Patch Analyst” in Relation to Flood Disaster

    Directory of Open Access Journals (Sweden)

    Tuan Pah Rokiah Syed Hussain

    2011-09-01

    Full Text Available In the recent decade, there are many government efforts to develop rural area as a step to curb vast economic discrepancy status within community in the nation. This effort is in line with National Development Policy promoted by government shifting from New Economic Policy. Therefore, this study area also has impact done by development activities. The enormous economic developments have encourage growth in urbanization, tourism and recreation, public facilities, housing and so on. Furthermore, the area of cultivation land uses and foliages are becoming shrinking due to development growth, which is development needs to shift land use pattern hence denotes that human beings infuriate the environment to meet the life needs. In response to that, this research delves into the level of land use changes using the Geographic Information System (GIS and Spatial Analyst to determine the actual area or vicinity and what is the type of rigorous changes in land use. This issue can be seen all the way through the study outcome via spatial analysis technique adapted from Patch Density & Size Metrics (Mean Patch Size, Edge Metrics (Total Edge (TE, Edge Density (ED, Mean Perimeter-Area Ratio (Mpar and Shannons Diversity Index (SHDI. Results of the study show that, land use changes have occurred significantly in the study area for the period of 20 years, wher, all types of analysis verify that there is an increase in patch for every statistical test. The increase in patch is a picture of current land use changes, land use edge density and land use area in study area. Moreover, this study investigates the relationship between land use with rising flood disaster frequency and intensity variable which has always happened lately in Kelantan River Basin.

  15. Drought to flood: a comparative assessment of four parallel surface water treatments during the 2010-2012 inflows to the Murray-Darling Basin, South Australia.

    Science.gov (United States)

    Braun, Kalan; Fabris, Rolando; Morran, Jim; Ho, Lionel; Drikas, Mary

    2014-08-01

    Four treatment processes; conventional coagulation, magnetic ion exchange (MIEX)/coagulation, with and without granular activated carbon (GAC), and membrane treatment combining microfiltration (MF) and nanofiltration (NF), were operated in parallel using the same source water from the Murray-Darling basin in South Australia. During the two year study, high levels of natural organic matter and turbidity arising from floods affecting the Murray-Darling basin in 2010-2012 challenged the four processes. The comparative study indicated that all four processes could effectively meet basic water quality guidelines of turbidity and colour despite challenging source water quality but that the more advanced treatments improved overall organic and bacterial removal. Interestingly, the high organics and turbidity arising from the floods resulted in improved treatment efficiency for all treatments incorporating coagulation to the extent that, despite flood conditions, treated water quality could remain comparatively constant provided that the process was operated and optimised effectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. FLOOD CHARACTERISTICS AND MANAGEMENT ADAPTATIONS ...

    African Journals Online (AJOL)

    Dr Osondu

    2011-10-26

    Oct 26, 2011 ... This paper examined the physical characteristics of floods and management adaptations to flood hazards in the Imo River basin. From the study, it was determined that the pre and post flood disaster management is a yearly event. The extent and time of commencement usually differs in each flood season ...

  17. Characterization and selection of biochar for an efficient retention of tricyclazole in a flooded alluvial paddy soil

    International Nuclear Information System (INIS)

    García-Jaramillo, Manuel; Cox, Lucía; Knicker, Heike E.; Cornejo, Juan; Spokas, Kurt A.; Hermosín, M.Carmen

    2015-01-01

    Highlights: • Biochar CEC was inversely correlated with HTT. • Enhanced aromaticity was associated to an improved biochar adsorption of tricyclazole. • The SSA of the biochars was inversely correlated with DOC contents. • Adsorption of tricyclazole was related to high SSA and low DOC content of biochars. • The use of AC and biochar in conjunction provides the slow release of tricyclazole. - Abstract: Biochars, from different organic residues, are increasingly proposed as soil amendments for their agronomic and environmental benefits. A systematic detection method that correlates biochar properties to their abilities to adsorb organic compounds is still lacking. Seven biochars obtained after pyrolysis at different temperatures and from different feedstock (alperujo compost, rice hull, and woody debris), were characterized and tested to reveal potential remedial forms for pesticide capture in flooded soils. Biochar properties were determined by nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy, specific surface area (SSA) assessment and scanning electron microscopy. In addition, dissolved organic matter (DOM) from these biochars was extracted and quantified in order to evaluate the effect on pesticide sorption. The biochars from alperujo compost presented very high affinity to the fungicide tricyclazole (55.9, 83.5, and 90.3% for B1, B4, and B5, respectively). This affinity was positively correlated with the pyrolysis temperature, the pH, the increased SSA of the biochars, and the enhanced aromaticity. Sorptive capacities were negatively related to DOM contents. The amendment with a mixture of compost and biochar endows the alluvial soil with high sorptive properties (from K fads(soil) = 9.26 to K fads(mixture) = 17.89) without impeding the slow release of tricyclazole

  18. Characterization and selection of biochar for an efficient retention of tricyclazole in a flooded alluvial paddy soil

    Energy Technology Data Exchange (ETDEWEB)

    García-Jaramillo, Manuel, E-mail: mgarcia@irnas.csic.es [Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), P.O. Box 1052, 41080 Seville (Spain); Cox, Lucía; Knicker, Heike E.; Cornejo, Juan [Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), P.O. Box 1052, 41080 Seville (Spain); Spokas, Kurt A. [United States Department of Agriculture–Agricultural Research Service, 1991 Upper Buford Circle, Saint Paul 55108, MN (United States); Hermosín, M.Carmen [Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), P.O. Box 1052, 41080 Seville (Spain)

    2015-04-09

    Highlights: • Biochar CEC was inversely correlated with HTT. • Enhanced aromaticity was associated to an improved biochar adsorption of tricyclazole. • The SSA of the biochars was inversely correlated with DOC contents. • Adsorption of tricyclazole was related to high SSA and low DOC content of biochars. • The use of AC and biochar in conjunction provides the slow release of tricyclazole. - Abstract: Biochars, from different organic residues, are increasingly proposed as soil amendments for their agronomic and environmental benefits. A systematic detection method that correlates biochar properties to their abilities to adsorb organic compounds is still lacking. Seven biochars obtained after pyrolysis at different temperatures and from different feedstock (alperujo compost, rice hull, and woody debris), were characterized and tested to reveal potential remedial forms for pesticide capture in flooded soils. Biochar properties were determined by nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy, specific surface area (SSA) assessment and scanning electron microscopy. In addition, dissolved organic matter (DOM) from these biochars was extracted and quantified in order to evaluate the effect on pesticide sorption. The biochars from alperujo compost presented very high affinity to the fungicide tricyclazole (55.9, 83.5, and 90.3% for B1, B4, and B5, respectively). This affinity was positively correlated with the pyrolysis temperature, the pH, the increased SSA of the biochars, and the enhanced aromaticity. Sorptive capacities were negatively related to DOM contents. The amendment with a mixture of compost and biochar endows the alluvial soil with high sorptive properties (from K{sub fads(soil)} = 9.26 to K{sub fads(mixture)} = 17.89) without impeding the slow release of tricyclazole.

  19. Monitoring the 2004 Flood in the Meghna River Basin in Bangladesh Using Ground Data, RADARSAT Imagery and GIS

    Science.gov (United States)

    Hoque, Roxana; Nakayama, Daichi; Matsuyama, Hiroshi; Matsumoto, Jun

    2010-05-01

    This study investigated an unusual flood event of 2004 in Bangladesh. The unusual early flood occurred in the 2nd week of April, and flood situation became worst when the greater Ganges-Brahmaputra-Meghna (GBM) rivers were coincidently synchronized their peaks on 24th of July. Flood hazard becomes a regular phenomenon in Bangladesh. In order to investigate the flood of 2004, we conducted a comparative analysis between major historical flood of 1998 with 2004 flood, using remote sensing, GIS and ground data. Five RADARSAT yearly maximum inundation images from 2000 to 2004 and three time series images of 2004 were used to identify wide flooding area around Bhairab Bazar, including northeastern Bangladesh. The result indicates that on 24th of July 2004, inundated areas in the northeastern region were about 29,900.72 km2. This result as well corresponded with the GBM rivers discharge, water level and rainfall anomaly maps. In 2004, about 5027.0 mm of annual rainfall found around Bhairab Bazar and 14816.8 mm at Cherrapunji in India. The annual rainfall anomaly maps from 2000 to 2005 illustrate that exceptionally high rainfall contributes severe flooding of northeastern Bangladesh. In 2004, the water level of the Meghna River at Bhairab Bazar station found that higher than that in 1998. In 2004, inundation period of Bhairab Bazar was longer than that in Bahadurabad of Brahmaputra River. From the flood damage maps and hazard maps, it was clarified that study area was very much vulnerable for flood disasters. It is crucial for Bangladesh to be able to monitor and assess the flood disasters using remote sensing and GIS techniques, to reduce the cost of general survey and hazard mapping services.

  20. Mercury exports from a High-Arctic river basin in Northeast Greenland (74°N) largely controlled by glacial lake outburst floods

    DEFF Research Database (Denmark)

    Søndergaard, Jens; Tamstorf, Mikkel P.; Elberling, Bo

    2015-01-01

    Riverine mercury (Hg) export dynamics from the Zackenberg River Basin (ZRB) in Northeast Greenland were studied for the period 2009-2013. Dissolved and sediment-bound Hg was measured regularly in the Zackenberg River throughout the periods with running water (June-October) and coupled to water di...... fraction of flood-controlled Hg export in this area. (C) 2015 Elsevier B.V. All rights reserved....... lake outburst floods in the ZRB in late summer at the time of maximum soil thaw depth, the location of the glacier in the upper ZRB, and increased thawing of the permafrost in Zackenberg in recent years leading to destabilisation of river banks are considered central factors explaining the high...

  1. Floods and Flash Flooding

    Science.gov (United States)

    Floods and flash flooding Now is the time to determine your area’s flood risk. If you are not sure whether you ... If you are in a floodplain, consider buying flood insurance. Do not drive around barricades. If your ...

  2. Evaluation and Application of Gridded Snow Water Equivalent Products for Improving Snowmelt Flood Predictions in the Red River Basin of the North

    Science.gov (United States)

    Schroeder, R.; Jacobs, J. M.; Vuyovich, C.; Cho, E.; Tuttle, S. E.

    2017-12-01

    Each spring the Red River basin (RRB) of the North, located between the states of Minnesota and North Dakota and southern Manitoba, is vulnerable to dangerous spring snowmelt floods. Flat terrain, low permeability soils and a lack of satisfactory ground observations of snow pack conditions make accurate predictions of the onset and magnitude of major spring flood events in the RRB very challenging. This study investigated the potential benefit of using gridded snow water equivalent (SWE) products from passive microwave satellite missions and model output simulations to improve snowmelt flood predictions in the RRB using NOAA's operational Community Hydrologic Prediction System (CHPS). Level-3 satellite SWE products from AMSR-E, AMSR2 and SSM/I, as well as SWE computed from Level-2 brightness temperatures (Tb) measurements, including model output simulations of SWE from SNODAS and GlobSnow-2 were chosen to support the snowmelt modeling exercises. SWE observations were aggregated spatially (i.e. to the NOAA North Central River Forecast Center forecast basins) and temporally (i.e. by obtaining daily screened and weekly unscreened maximum SWE composites) to assess the value of daily satellite SWE observations relative to weekly maximums. Data screening methods removed the impacts of snow melt and cloud contamination on SWE and consisted of diurnal SWE differences and a temperature-insensitive polarization difference ratio, respectively. We examined the ability of the satellite and model output simulations to capture peak SWE and investigated temporal accuracies of screened and unscreened satellite and model output SWE. The resulting SWE observations were employed to update the SNOW-17 snow accumulation and ablation model of CHPS to assess the benefit of using temporally and spatially consistent SWE observations for snow melt predictions in two test basins in the RRB.

  3. Evolvement rules of basin flood risk under low-carbon mode. Part I: response of soil organic carbon to land use change and its influence on land use planning in the Haihe basin.

    Science.gov (United States)

    Li, Fawen; Wang, Liping; Zhao, Yong

    2017-08-01

    Soil organic carbon (SOC) plays an important role in the global carbon cycle. The aim of this study was to evaluate the response of SOC to land use change and its influence on land use planning in the Haihe basin, and provide planning land use pattern for basin flood risk assessment. Firstly, the areas of different land use types in 1980, 2008, and the planning year (2020) were counted by area statistics function of ArcGIS. Then, the transfer matrixes of land use were produced by spatial overlay analysis function. Lastly, based on the land use maps, soil type map and soil profile database, SOC storage of different land use types in three different periods were calculated. The results showed the patterns of land use have changed a lot from 1980 to 2008, among the 19,835 km 2 of grassland was transformed into forestland, which was the largest conversion landscape. And land use conversion brought the SOC storage changes. Total carbon source was 88.83 Tg, and total carbon sink was 85.49 Tg. So, the Haihe basin presented as a carbon source from 1980 to 2008. From 2008 to 2020, the changes of forestland and grassland are the biggest in Haihe basin, which cause the SOC pool change from a carbon source to a carbon sink. SOC storage will increase from 2420.5 Tg in 2008 to 2495.5 Tg in 2020. The changing trend is conducive to reducing atmospheric concentrations. Therefore, land use planning in Haihe basin is reasonable and can provide the underlying surface condition for flood risk assessment.

  4. Climatic and basin factors affecting the flood frequency curve: PART I – A simple sensitivity analysis based on the continuous simulation approach

    Directory of Open Access Journals (Sweden)

    A. M. Hashemi

    2000-01-01

    Full Text Available Regionalized and at-site flood frequency curves exhibit considerable variability in their shapes, but the factors controlling the variability (other than sampling effects are not well understood. An application of the Monte Carlo simulation-based derived distribution approach is presented in this two-part paper to explore the influence of climate, described by simulated rainfall and evapotranspiration time series, and basin factors on the flood frequency curve (ffc. The sensitivity analysis conducted in the paper should not be interpreted as reflecting possible climate changes, but the results can provide an indication of the changes to which the flood frequency curve might be sensitive. A single site Neyman Scott point process model of rainfall, with convective and stratiform cells (Cowpertwait, 1994; 1995, has been employed to generate synthetic rainfall inputs to a rainfall runoff model. The time series of the potential evapotranspiration (ETp demand has been represented through an AR(n model with seasonal component, while a simplified version of the ARNO rainfall-runoff model (Todini, 1996 has been employed to simulate the continuous discharge time series. All these models have been parameterised in a realistic manner using observed data and results from previous applications, to obtain ‘reference’ parameter sets for a synthetic case study. Subsequently, perturbations to the model parameters have been made one-at-a-time and the sensitivities of the generated annual maximum rainfall and flood frequency curves (unstandardised, and standardised by the mean have been assessed. Overall, the sensitivity analysis described in this paper suggests that the soil moisture regime, and, in particular, the probability distribution of soil moisture content at the storm arrival time, can be considered as a unifying link between the perturbations to the several parameters and their effects on the standardised and unstandardised ffcs, thus revealing the

  5. Use of real-time monitoring to predict concentrations of select constituents in the Menomonee River drainage basin, Southeast Wisconsin, 2008-9

    Science.gov (United States)

    Baldwin, Austin K.; Graczyk, David J.; Robertson, Dale M.; Saad, David A.; Magruder, Christopher

    2012-01-01

    The Menomonee River drainage basin in southeast Wisconsin is undergoing changes that may affect water quality. Several rehabilitation and flood-management projects are underway, including removal of concrete channels and the construction of floodwater retention basins. The city of Waukesha may begin discharging treated wastewater into Underwood Creek, thus approximately doubling the current base-flow discharge. In addition, the headwater basins, historically dominated by agriculture and natural areas, are becoming increasingly urbanized.

  6. The character and causes of flash flood occurrence changes in mountainous small basins of Southern California under projected climatic change

    Directory of Open Access Journals (Sweden)

    Theresa M. Modrick

    2015-03-01

    Full Text Available Study region: Small watersheds (O[25 km2] in the mountain regions of southern California comprise the study region. Study focus: This paper examines changes in flash flood occurrence in southern California resulting from projected climatic change. The methodology synthesizes elements of meteorological modeling, hydrology and geomorphology into an integrated modeling approach to define flash flood occurrence in a systematic and consistent way on a regional basis with high spatial and temporal resolution appropriate for flash flooding. A single climate model with three-dimensional atmospheric detail was used as input to drive simulations for historical and future periods. New hydrological insights for the region: Results indicate an increase in flash flood occurrence for the study region. For two distributed hydrologic models employed, the increase in flash flood occurrence frequency is on average between 30% and 40%. Regional flash flood occurrence is characterized by near saturation of the upper soil layer, and wider ranges in lower soil layer saturation and in precipitation. Overall, a decrease in the total number of precipitation events was found, although with increased precipitation intensity, increased event duration, and higher soil saturation conditions for the 21st century. This combination could signify more hazardous conditions, with fewer precipitation events but higher rainfall intensity and over soils with higher initial soil moisture saturation, leading to more frequent occurrence of flash floods. Keywords: Flash flooding, Climate change, Soil moisture, Precipitation, Distributed hydrologic modeling

  7. Towards sustainable flood risk management in the Rhine and Meuse river basins: synopsis of the findings of IRMA-SPONGE

    NARCIS (Netherlands)

    Hooijer, A.; Klijn, F.; Pedroli, G.B.M.; Os, van A.G.

    2004-01-01

    Recent flood events in western Europe have shown the need for improved flood risk management along the Rhine and Meuse rivers. In response, the IRMA-SPONGE research programme was established, consisting of 13 research projects, in which over 30 organizations from six countries co-operated. The aim

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

    Directory of Open Access Journals (Sweden)

    M. Schulte

    2015-06-01

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

  9. Morphometric factors as conditioning variables in the occurrence of floods in the Serafim Stream basin, subbasin of the Paraibuna River, Juiz de Fora, MG

    Directory of Open Access Journals (Sweden)

    Raquel Callegario Zacchi

    2013-01-01

    Full Text Available As they encourage the monitoring of natural changes introduced by man such as soil use and occupation, basins should be considered as planning units because they allow for the monitoring of their activities in order to preserve natural resources. This study aims to characterize the watershed of the Serafim Stream, subbasin of the Paraibuna River, located in Juiz de Fora, MG, regarding its morphometric features. To do this, it was necessary to limit the basin area inserted in the map by IBGE (Juiz de Fora SF - 23 - X - D - IV - 1, scale 1:50,000. The basin has an area of 39.8 km2, drainage order equal to five and guidance to the northeast. The drainage pattern has been classified as dendritic, indicating average drainage capacity. Through the correlation between the morphometric factors, it can be stated that the basin has a median susceptibility to flooding.

  10. Effects of an Extreme Flood on Trace Elements in River Water-From Urban Stream to Major River Basin.

    Science.gov (United States)

    Barber, Larry B; Paschke, Suzanne S; Battaglin, William A; Douville, Chris; Fitzgerald, Kevin C; Keefe, Steffanie H; Roth, David A; Vajda, Alan M

    2017-09-19

    Major floods adversely affect water quality through surface runoff, groundwater discharge, and damage to municipal water infrastructure. Despite their importance, it can be difficult to assess the effects of floods on streamwater chemistry because of challenges collecting samples and the absence of baseline data. This study documents water quality during the September 2013 extreme flood in the South Platte River, Colorado, USA. Weekly time-series water samples were collected from 3 urban source waters (municipal tap water, streamwater, and wastewater treatment facility effluent) under normal-flow and flood conditions. In addition, water samples were collected during the flood at 5 locations along the South Platte River and from 7 tributaries along the Colorado Front Range. Samples were analyzed for 54 major and trace elements. Specific chemical tracers, representing different natural and anthropogenic sources and geochemical behaviors, were used to compare streamwater composition before and during the flood. The results differentiate hydrological processes that affected water quality: (1) in the upper watershed, runoff diluted most dissolved constituents, (2) in the urban corridor and lower watershed, runoff mobilized soluble constituents accumulated on the landscape and contributed to stream loading, and (3) flood-induced groundwater discharge mobilized soluble constituents stored in the vadose zone.

  11. Effects of an extreme flood on trace elements in river water—From urban stream to major river basin

    Science.gov (United States)

    Barber, Larry B.; Paschke, Suzanne; Battaglin, William A.; Douville, Chris; Fitzgerald, Kevin C.; Keefe, Steffanie H.; Roth, David A.; Vajda, Alan M.

    2017-01-01

    Major floods adversely affect water quality through surface runoff, groundwater discharge, and damage to municipal water infrastructure. Despite their importance, it can be difficult to assess the effects of floods on streamwater chemistry because of challenges collecting samples and the absence of baseline data. This study documents water quality during the September 2013 extreme flood in the South Platte River, Colorado, USA. Weekly time-series water samples were collected from 3 urban source waters (municipal tap water, streamwater, and wastewater treatment facility effluent) under normal-flow and flood conditions. In addition, water samples were collected during the flood at 5 locations along the South Platte River and from 7 tributaries along the Colorado Front Range. Samples were analyzed for 54 major and trace elements. Specific chemical tracers, representing different natural and anthropogenic sources and geochemical behaviors, were used to compare streamwater composition before and during the flood. The results differentiate hydrological processes that affected water quality: (1) in the upper watershed, runoff diluted most dissolved constituents, (2) in the urban corridor and lower watershed, runoff mobilized soluble constituents accumulated on the landscape and contributed to stream loading, and (3) flood-induced groundwater discharge mobilized soluble constituents stored in the vadose zone.

  12. The influence of controlled floods on fine sediment storage in debris fan-affected canyons of the Colorado River basin

    Science.gov (United States)

    Mueller, Erich R.; Grams, Paul E.; Schmidt, John C.; Hazel, Joseph E.; Alexander, Jason S.; Kaplinski, Matt

    2014-01-01

    Prior to the construction of large dams on the Green and Colorado Rivers, annual floods aggraded sandbars in lateral flow-recirculation eddies with fine sediment scoured from the bed and delivered from upstream. Flows greater than normal dam operations may be used to mimic this process in an attempt to increase time-averaged sandbar size. These controlled floods may rebuild sandbars, but sediment deficit conditions downstream from the dams restrict the frequency that controlled floods produce beneficial results. Here, we integrate complimentary, long-term monitoring data sets from the Colorado River in Marble and Grand Canyons downstream from Glen Canyon dam and the Green River in the Canyon of Lodore downstream from Flaming Gorge dam. Since the mid-1990s, several controlled floods have occurred in these canyon rivers. These controlled floods scour fine sediment from the bed and build sandbars in eddies, thus increasing channel relief. These changes are short-lived, however, as interflood dam operations erode sandbars within several months to years. Controlled flood response and interflood changes in bed elevation are more variable in Marble Canyon and Grand Canyon, likely reflecting more variable fine sediment supply and stronger transience in channel bed sediment storage. Despite these differences, neither system shows a trend in fine-sediment storage during the period in which controlled floods were monitored. These results demonstrate that controlled floods build eddy sandbars and increase channel relief for short interflood periods, and this response may be typical in other dam-influenced canyon rivers. The degree to which these features persist depends on the frequency of controlled floods, but careful consideration of sediment supply is necessary to avoid increasing the long-term sediment deficit.

  13. Spatial and seasonal responses of precipitation in the Ganges and Brahmaputra river basins to ENSO and Indian Ocean dipole modes: implications for flooding and drought

    Science.gov (United States)

    Pervez, Md Shahriar; Henebry, Geoffry M.

    2015-01-01

    We evaluated the spatial and seasonal responses of precipitation in the Ganges and Brahmaputra basins as modulated by the El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) modes using Global Precipitation Climatology Centre (GPCC) full data reanalysis of monthly global land-surface precipitation data from 1901 to 2010 with a spatial resolution of 0.5° × 0.5°. The GPCC monthly total precipitation climatology targeting the period 1951–2000 was used to compute gridded monthly anomalies for the entire time period. The gridded monthly anomalies were averaged for the years influenced by combinations of climate modes. Occurrences of El Niño alone significantly reduce (88% of the long-term average (LTA)) precipitation during the monsoon months in the western and southeastern Ganges Basin. In contrast, occurrences of La Niña and co-occurrences of La Niña and negative IOD events significantly enhance (110 and 109% of LTA in the Ganges and Brahmaputra Basin, respectively) precipitation across both basins. When El Niño co-occurs with positive IOD events, the impacts of El Niño on the basins' precipitation diminishes. When there is no active ENSO or IOD events (occurring in 41 out of 110 years), precipitation remains below average (95% of LTA) in the agriculturally intensive areas of Haryana, Uttar Pradesh, Rajasthan, Madhya Pradesh, and Western Nepal in the Ganges Basin, whereas precipitation remains average to above average (104% of LTA) across the Brahmaputra Basin. This pattern implies that a regular water deficit is likely, especially in the Ganges Basin, with implications for the agriculture sector due to its reliance on consistent rainfall for successful production. Historically, major droughts occurred during El Niño and co-occurrences of El Niño and positive IOD events, while major flooding occurred during La Niña and co-occurrences of La Niña and negative IOD events in the basins. This observational analysis will facilitate well

  14. Flooding and Flood Management

    Science.gov (United States)

    Brooks, K.N.; Fallon, J.D.; Lorenz, D.L.; Stark, J.R.; Menard, Jason; Easter, K.W.; Perry, Jim

    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.

  15. Analysis of the flooding event of October 22-23, 2005 in a small basin in the province of Bari (Southern Italy

    Directory of Open Access Journals (Sweden)

    Tiziana Bisantino

    2016-12-01

    Full Text Available In the province of Bari the hydrographic network consists of ephemeral streams called lame. In these watercourses the absence of runoff for long periods contributed to unfounded beliefs concerning the hydraulic safety of the landscape and therefore uncontrolled changes in streambeds and floodplains. In these streams high water discharges can occur during heavy rainfalls, as demonstrated by the floods that hit the city of Bari in the late nineteenth and early twentieth century. The flooding event of October 22-23, 2005 can be considered catastrophic as it resulted in six deaths, numerous injuries and substantial damage sustained by road and railway infrastructures at the intersection with the hydrographic network. This study aims to analyse the severity of the event in terms of the response of the landscape with reference to the case of the lama Scappagrano basin, where a Eurostar train derailed due to the collapse of the railway embankment. Coupled hydrological and two-dimensional hydraulic modelling was performed to reconstruct the flood hydrograph and water depths on the upstream side of the embankment. The results were used to set the boundary conditions to analyse the internal stability of the embankment using a finite element method.

  16. Mercury exports from a High-Arctic river basin in Northeast Greenland (74°N) largely controlled by glacial lake outburst floods.

    Science.gov (United States)

    Søndergaard, Jens; Tamstorf, Mikkel; Elberling, Bo; Larsen, Martin M; Mylius, Maria Rask; Lund, Magnus; Abermann, Jakob; Rigét, Frank

    2015-05-01

    Riverine mercury (Hg) export dynamics from the Zackenberg River Basin (ZRB) in Northeast Greenland were studied for the period 2009-2013. Dissolved and sediment-bound Hg was measured regularly in the Zackenberg River throughout the periods with running water (June-October) and coupled to water discharge measurements. Also, a few samples of snow, soil, and permafrost were analysed for Hg. Mean concentrations of dissolved and sediment-bound Hg in the river water (±SD) were 0.39 ± 0.13 and 5.5 ± 1.4 ngL(-1), respectively, and mean concentrations of Hg in the river sediment were 0.033 ± 0.025 mg kg(-1). Temporal variations in river Hg were mainly associated with snowmelt, sudden erosion events, and outburst floods from a glacier-dammed lake in the upper part of the ZRB. Annual Hg exports from the 514 km(2) ZRB varied from 0.71 to >1.57 kg and the majority (86-96%) was associated with sediment-bound Hg. Hg yields from the ZRB varied from 1.4-3.1 gH gk m(-2)yr(-1) and were among the highest yields reported from Arctic river basins. River exports of Hg from ZRB were found to be largely controlled by the frequency, magnitude and timing of the glacial lake outburst floods, which occurred in four of the five years in July-August. Floods accounted for 5 to >10% of the annual water discharge, and up to >31% of the annual Hg export. Also, the winter snowfall and the summer temperatures were found to be important indirect controls on the annual Hg export. The occurrence and timing of glacial lake outburst floods in the ZRB in late summer at the time of maximum soil thaw depth, the location of the glacier in the upper ZRB, and increased thawing of the permafrost in Zackenberg in recent years leading to destabilisation of river banks are considered central factors explaining the high fraction of flood-controlled Hg export in this area. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Introduction: Geomorphic studies of the storm and flood of November 3-5, 1985, in the upper Potomac and Cheat River basins: Chapter A in Geomorphic studies of the storm and flood of November 3-5, 1985, in the upper Potomac and Cheat River basins in West Virginia and Virginia

    Science.gov (United States)

    Jacobson, Robert B.

    1993-01-01

    The heavy rains of November 3-5, 1985, produced record floods and extensive landsliding in the Potomac and Cheat River basins in West Virginia and Virginia (pl. 1). Although rainfall intensity was moderate, the storm covered a very large area and produced record floods for basins in the size range of 1000-10,000 km2. In addition, thousands of landslides were triggered on slopes underlain by shale bedrock. The total social cost of the storm amounted to 70 lives lost and an estimated $1.3 billion in damage to homes, businesses, roads, and productive land in West Virginia and Virginia (Federal Emergency Management Agency (FEMA) 1985a, b). These extreme costs were incurred despite the fact that the affected area is sparsely populated. To understand the origins and geomorphic effects of the 1985 storm, studies were undertaken by the U.S. Geological Survey, University of Maryland, West Virginia University, Cornell University, University of Virginia, The Johns Hopkins University, and Carleton College. Personnel were also consulted from the National Weather Service, Nuclear Regulatory Commission, U.S. Army Corps of Engineers, Soil Conservation Service, and Interstate Commission on the Potomac River basin. This cooperative effort serves to document the effects of the storm as an example of an extreme geomorphic event in the central Appalachian Mountains. The following chapters comprise observations and preliminary analyses for some of the observed phenomena. Subsequent publications by the contributors to this volume will expand the scope of this research.

  18. Bias correction of satellite precipitation products for flood forecasting application at the Upper Mahanadi River Basin in Eastern India

    Science.gov (United States)

    Beria, H.; Nanda, T., Sr.; Chatterjee, C.

    2015-12-01

    High resolution satellite precipitation products such as Tropical Rainfall Measuring Mission (TRMM), Climate Forecast System Reanalysis (CFSR), European Centre for Medium-Range Weather Forecasts (ECMWF), etc., offer a promising alternative to flood forecasting in data scarce regions. At the current state-of-art, these products cannot be used in the raw form for flood forecasting, even at smaller lead times. In the current study, these precipitation products are bias corrected using statistical techniques, such as additive and multiplicative bias corrections, and wavelet multi-resolution analysis (MRA) with India Meteorological Department (IMD) gridded precipitation product,obtained from gauge-based rainfall estimates. Neural network based rainfall-runoff modeling using these bias corrected products provide encouraging results for flood forecasting upto 48 hours lead time. We will present various statistical and graphical interpretations of catchment response to high rainfall events using both the raw and bias corrected precipitation products at different lead times.

  19. Effect of seasonal flooding cycle on litterfall production in alluvial rainforest on the middle Xingu River (Amazon basin, Brazil).

    Science.gov (United States)

    Camargo, M; Giarrizzo, T; Jesus, A J S

    2015-08-01

    The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.

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

    Science.gov (United States)

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

    2010-09-01

    In the last four centuries, the Ondara River has flash-flooded several times the town of Tàrrega (NE Spain), resulting in a huge amount of deaths and damages to buildings. Indeed, from the early XVIIth Century, a minimum of six major events have occurred, in which the old-town streets have been flooded -in some cases, up to the dwellings’ second floor-, commonly during night hours, with an obvious surprise factor which added to the quickness of the events. These six events happened in 1644, 1783, 1842, 1874, 1930 and 1989; the flood marks preserved in Sant Agustí Street at Tàrrega allowed the reconstruction of the peak flows. The Ondara River catchment at Tàrrega has an area of 150 km2 and an average slope of 1,6%; there are neither gauging records nor hydraulic structures. In order to find a relationship between magnitude and frequency of the major flash floods, a two-staged methodology was used: in the first stage, the sediment-laden peak flow of each flood was calculated; in the second one, an extreme value distribution function was fitted to those peak flows in order to assess their recurrence likelihood. More in detail, each flash flood peak flow was reconstructed through the iterative application of a hydraulic model. The input data for each modelling were: i) a digital terrain model of the river bed; for each flood, the topographic and the land use changes given by contemporary maps and archaeological data were taken into account ii) the stream, floodplain and urban areas roughness coefficients (0.035, 0.04, and 0.1, respectively) iii) the channel slope (0.0045) iv) a tentative peak flow. As said above, the process was iterative, trying different peak flows until the modelled maximum water level was close enough to the one known through the flood limnimarks. The hydraulic model used was the unidimensional HEC-RAS v. 4.0/2008 (USACE), applied in several cross sections of the Ondara River at Tàrrega, spaced 40-50 m in average. Thence, the Bayliss & Reed

  1. Analysis and projections of climate change impacts on flood risks in the Dniester river basin based on the ENSEMBLES RCM data

    Science.gov (United States)

    Krakovska, S.; Balabukh, V.; Palamarchuk, L.; Djukel, G.; Gnatiuk, N.

    2012-04-01

    The pilot project "Reducing vulnerability to extreme floods and climate change in the Dniester river basin" started in May 2010 in the frame of the Dniester-III project which is implemented by OSCE, UNECE and UNEP in close collaboration with authorities and NGOs from Moldova and Ukraine. The project is a part of the Environment and Security initiative (ENVSEC) and aims to reduce risks from climate change - and specifically flooding - for security by improving the adaptive capacity of Ukraine and the Republic of Moldova, taking into account both current climate variability and long-term impacts of climate change on flood risks (http://www1.unece.org/ehlm/platform/display/ClimateChange/Dniester). The Dniester is a river in Eastern Europe, one of the largest rivers of the Carpathians. The Dniester flows from northwest to southeast on the territory of Ukraine, Moldova and Transdniestria. The length of the Dniester is 1352 km with basin area of 72100 km2. The river starts in the Carpathian Mountains at an altitude of 900 m above the sea level and flows into the Dniester estuary, which is connected to the Black Sea. In order to reduce impacts from extreme floods in the Dniester river basin under transient climate conditions the first task of the project was to assess the recent climate changes and particularly extreme precipitation events. For this purpose database of the specially worked out system with inputs from observational data from 1980 up to now of all stations within the Dniester basin was applied. Retrospective analysis of severe hydrometeorological events has revealed that more than 30% of precipitation at warm half of the year are heavy and very heavy rains. And input of such extreme precipitation to annual sum increased during last 30 year by about 7% per decade in the region. Possible reason for this is an intensification of convection in bottom 5km layer of the troposphere which is observed from the middle 90th of the 20th century. During this period an

  2. Role of flood discharge in shaping stream geometry: Analysis of a small modern stream in the Uinta Basin, USA

    Directory of Open Access Journals (Sweden)

    Guang-Ming Hu

    2017-01-01

    This stream example demonstrates the subtleties of stream flow and the importance of flood discharge in shaping the channel geometry. Although it is difficult to scale up this example to a large river system that carves geomorphic landscape, this case shows how river geometries vary from the traditional patterns due to different gradient.

  3. Landslide and glacial lake outburst flood hazard in the Chucchún river basin, Cordillera Blanca, Peru

    Czech Academy of Sciences Publication Activity Database

    Klimeš, Jan; Vilímek, V.; Benešová, M.

    2015-01-01

    Roč. 50, č. 2 (2015), s. 173-180 ISSN 0300-5402 R&D Projects: GA ČR(CZ) GAP209/11/1000 Institutional support: RVO:67985891 Keywords : landslide hazard * GLOFs * flood hazard * Cordillera Blanca * Peru Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  4. Transboundary river basin management in Europe
    Legal instruments to comply with European water management obligations in case of transboundary water pollution and floods

    Directory of Open Access Journals (Sweden)

    Andrea M. Keessen

    2008-12-01

    Full Text Available Although modern European water policy follows a river basin approach where Member States have to cooperate in order to achieve a ‘good status’ of their water bodies, the obligations arising from the European water directives are to be achieved by each Member State individually. This situation creates problems when water pollution and water quantity problems cross borders. It is still unclear whether Member States can be held responsible for not achieving objectives due to causes (partly originating abroad. This article describes some of the legal instruments that water authorities have at their disposal to comply with the European water management obligations in case of transboundary water pollution and floods and thus shape transboundary river management. The article describes instruments to create, implement and enforce transboundary cooperation, and addresses the possibility of transboundary compensation if cooperation fails. Here, the focus is on a civil lawsuit before a domestic court.

  5. Structure and Dynamics of Floods in the upper Delaware River Basin: An Integrated Seasonal Forecasting System for New York City Reservoirs

    Science.gov (United States)

    Najibi, N.; Devineni, N.

    2016-12-01

    The National Weather Service River Forecasting System (NWS-RFS) issues 3-month lead probabilistic forecasts of streamflow for many river basins in the contiguous United States from 12 river forecasting centers. The Ensemble Streamflow Prediction system from NWS-RFS uses conceptual hydrologic models to issue streamflow forecasts based on the current soil moisture, river, and reservoir conditions by assuming that past meteorological events will recur in the future with historical probabilities. Recent investigations focusing on the teleconnection between anomalous sea surface temperature conditions and regional/continental hydroclimatology show that interannual and interdecadal variability in exogenous climatic indices modulates the regional streamflow patterns. In this work, we present a comprehensive framework to quantify the structure and dynamics of floods for the upper Delaware River Basin based on the interaction between the exogenous climate and weather patterns and antecedent flow regimes. We focus on estimating the conditional distribution of flood volume, duration, peak and timing based on large-scale climatic teleconnections (seasonal sea level pressure and pre-season sea surface temperature) and macroscale hydrological factors (start of the season's flow, seasonal rainfall duration and intensity, pre-season snow depth and cover in watershed, and concurrent rain over snow (ROS) events). Statistical techniques such as the semi-parametric k-nearest neighbor resampling, multivariate Kalman filters, and hierarchical Bayesian methods are explored as a strategy to address both model and parameter uncertainties. Ultimately proactive decision models embedded into the operating rules based on the forecasted future conditions -instead of reactive decisions based on current observed conditions- can result in risk mitigation.

  6. NAA: metals in surface waters, margin sediments, forage and cattle hair in flood plains of the Rio Doce basin, Minas Gerais, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Maria Adelaide R.V., E-mail: madelaide@fumec.br [Universidade Fundacao Mineira de Educacao e Cultura (FUMEC), Belo Horizonte, MG (Brazil). Mestrado em Construcao Civil, Meio Ambiente; Barbosa, Ana Flavia S.; Ruckert, Gabriela V., E-mail: mariavasc@unilestemg.br [Centro Universitario do Leste de Minas Gerais (UnilesteMG), Coronel Fabriciano, MG (Brazil). Mestrado em Engenharia Industrial; Menezes, Maria Angela B.C.; Silva, Maria Aparecida, E-mail: menezes@cdtn.br, E-mail: cida@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Arno H. de, E-mail: heeren@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Departamento de Engenharia Nuclear Belo Horizonte, MG (Brazil)

    2011-07-01

    Metals are toxic and can cause damage to human health when they accumulate in the food chain. The aim of this study was to determine Al, As, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hg, K, Mg, Mn, Na, Rb, Sb, Sc, Ta, Th, Ti, U, V and Zn in different samples: surface waters, margin sediments, forages and cattle hairs in the region of the Rio Doce basin. The metals were analyzed by Neutron Activation Analysis - NAA at the Centre for Development of Nuclear Technology of the National Commission of Nuclear Energy - CDTN / CNEN. The sampling sites were taken at two points: P1- (Pingo D'agua - city, Ponte Queimada, in a no industrial area) and P2 - (Santana do Paraiso city, industrial and pasture areas, subject to frequent floods). The samples were collected in different seasons: July 2009 (dry season - winter) and February 2010 (rainy season - summer). These points were strategically chosen because P1 is located into the Parque Estadual do Rio Doce, considered a no industrial pollution region. Contrariwise, P2 is located in a region of high concentration of industries. In (P2) the Doce River receives its most polluted affluent upstream the Piracicaba River which is charged of several pollutants of industries of Steel Valley region, Brazil. In general, the results showed higher concentrations of the elements in P2 riverside area of livestock production and subject to flood. (author)

  7. NAA: metals in surface waters, margin sediments, forage and cattle hair in flood plains of the Rio Doce basin, Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Vasconcelos, Maria Adelaide R.V.; Oliveira, Arno H. de

    2011-01-01

    Metals are toxic and can cause damage to human health when they accumulate in the food chain. The aim of this study was to determine Al, As, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hg, K, Mg, Mn, Na, Rb, Sb, Sc, Ta, Th, Ti, U, V and Zn in different samples: surface waters, margin sediments, forages and cattle hairs in the region of the Rio Doce basin. The metals were analyzed by Neutron Activation Analysis - NAA at the Centre for Development of Nuclear Technology of the National Commission of Nuclear Energy - CDTN / CNEN. The sampling sites were taken at two points: P1- (Pingo D'agua - city, Ponte Queimada, in a no industrial area) and P2 - (Santana do Paraiso city, industrial and pasture areas, subject to frequent floods). The samples were collected in different seasons: July 2009 (dry season - winter) and February 2010 (rainy season - summer). These points were strategically chosen because P1 is located into the Parque Estadual do Rio Doce, considered a no industrial pollution region. Contrariwise, P2 is located in a region of high concentration of industries. In (P2) the Doce River receives its most polluted affluent upstream the Piracicaba River which is charged of several pollutants of industries of Steel Valley region, Brazil. In general, the results showed higher concentrations of the elements in P2 riverside area of livestock production and subject to flood. (author)

  8. The waterways of Tangail: Failures to learn from flood control efforts in the Brahmaputra basin of Bangladesh

    Directory of Open Access Journals (Sweden)

    Crelis F. Rammelt

    2018-02-01

    Full Text Available Traditional non-structural approaches to water management and flood protection in Bengal disappeared almost entirely under colonial and national water planning. The 1950s saw the rise of permanent and centrally regulated infrastructures for flood control, drainage and irrigation (FCD/I. A nationwide Flood Action Plan (FAP in the 1990s reinforced this structural approach and included as one of its flagships of the FAP-20 component in the Tangail District. While essentially remaining a form of FCD/I, FAP-20 attempted to pay attention to social and ecological concerns. During its implementation (1991-2000, however, FAP-20 became highly controversial on both accounts. Eventually, it was phased out and not replicated elsewhere. Revisiting this particular project is as relevant as ever for several reasons. First, the article shows that its negative impacts are felt long after the project ended. To better understand these impacts, the present article provides a historical and contextual perspective on water governance in Bangladesh. Second, there seems to have been little learning from the FAP-20 experience. The project was not adequately evaluated, and lessons are therefore not assimilated by the design of subsequent water-sector projects (e.g. the Blue Gold plan. The article argues that a thorough evaluation is needed and can provide valuable insights for the development of more adaptive and inclusive approaches to water management.

  9. Stratigraphy and structural development of the southwest Isla Tiburón marine basin: Implications for latest Miocene tectonic opening and flooding of the northern Gulf of California

    Science.gov (United States)

    Bennett, Scott E. K.; Oskin, Michael; Dorsey, Rebecca; Iriondo, Alexander; Kunk, Michael J.

    2015-01-01

    foraminifera from this section. Results from biostratigraphy and geochronology thus constrain earliest marine deposition on SWIT to ca. 6.2 ± 0.2 Ma, coincident with a regional-scale latest Miocene marine incursion into the northern proto-Gulf of California. This regional marine incursion flooded the northernmost, >500-km-long portion of the Gulf of California shear zone, a narrow belt of localized strike-slip faulting, clockwise block rotation, and subsiding pull-apart basins. Oblique Pacific-North America relative plate motion gradually localized in the >1000-km-long Gulf of California shear zone ca. 9-6 Ma, subsequently permitting the punctuated south to north flooding of the incipient Gulf of California seaway.

  10. Palaeoenvironments and facies on a progressively flooded rocky island (Upper Cenomanian – Lower Turonian, Bohemian Cretaceous Basin)

    Czech Academy of Sciences Publication Activity Database

    Žítt, Jiří; Vodrážka, R.; Hradecká, L.; Svobodová, Marcela

    2010-01-01

    Roč. 179, - (2010), s. 223-234 ISSN 1802-6842 Institutional research plan: CEZ:AV0Z30130516 Keywords : Cretaceous island * weathering * geomorphology * sedimentary environments * biostratigraphy * Upper Cenomanian-Lower Turonian * Bohemian Cretaceous Basin Subject RIV: DB - Geology ; Mineralogy http://www.nm.cz/publikace/archiv-en.php?id=1&rok=179&f_=Show

  11. Geologic, geomorphologic evaluation and analysis of the degree of susceptibility to floods and torrential avenues in the sub-basin of the Cambia Ravine, Municipalities of Anserma, Risaralda and San Jose, (Caldas)

    International Nuclear Information System (INIS)

    Franco H, Mariana; Guapacha, Ana Maria

    2002-01-01

    The Cambia sub-basin is located in Colombia's western cordillera and has an extension of 89,39 k m2, it is affected by the Rome ral Fault System. The lithology of the area consists of cretaceous rocks of the Diabasic B/R's Formation which is the basement of the area, this unit is overlaid by the tertiary unit of alluvial terraces of the C.c. River and the quaternary units of the: Plan de Aeromonas Mud flow, and the recent alluvial deposits. This thesis aimed to know the geology, geomorphology, mass movements and the susceptibility to river flood susceptibility. The hazard analysis was based on the cartographic updating and analysis of the geology, fluvial geomorphology, the mass movements' characterization, the flow was calculated via the Swat software based on precipitation data and later on the delimitation of the flooded areas was accomplished by using the Heck-Gar's software plus a qualitative analysis of the sub-basin. The main conclusions of this study are: There is flood hazard within this sub-basin, The flooded hazard areas were delimited for the return periods calculated and these areas require an adequate management. This thesis intended to evaluate the susceptibility analysis but the hazard analysis was accomplished. The methodology used is highly recommended for areas, which have the necessary specification to apply it

  12. Dynamic Water Storage during Flash Flood Events in the Mountainous Area of Rio de Janeiro/Brazil - Case study: Piabanha River Basin

    Science.gov (United States)

    Araujo, L.; Silva, F. P. D.; Moreira, D. M.; Vásquez P, I. L.; Justi da Silva, M. G. A.; Fernandes, N.; Rotunno Filho, O. C.

    2017-12-01

    Flash floods are characterized by a rapid rise in water levels, high flow rates and large amounts of debris. Several factors have relevance to the occurrence of these phenomena, including high precipitation rates, terrain slope, soil saturation degree, vegetation cover, soil type, among others. In general, the greater the precipitation intensity, the more likely is the occurrence of a significant increase in flow rate. Particularly on steep and rocky plains or heavily urbanized areas, relatively small rain rates can trigger a flash flood event. In addition, high rain rates in short time intervals can temporarily saturate the surface soil layer acting as waterproofing and favoring the occurrence of greater runoff rates due to non-infiltration of rainwater into the soil. Thus, although precipitation is considered the most important factor for flooding, the interaction between rainfall and the soil can sometimes be of greater importance. In this context, this work investigates the dynamic storage of water associated with flash flood events for Quitandinha river watershed, a tributary of Piabanha river, occurred between 2013 and 2014, by means of water balance analyses applied to three watersheds of varying magnitudes (9.25 km², 260 km² and 429 km²) along the rainy season under different time steps (hourly and daily) using remotely sensed and observational precipitation data. The research work is driven by the hypothesis of a hydrologically active bedrock layer, as the watershed is located in a humid region, having intemperate (fractured) rock layer, just below a shallow soil layer, in the higher part of the basin where steep slopes prevail. The results showed a delay of the variation of the dynamic storage in relation to rainfall peaks and water levels. Such behavior indicates that the surface soil layer, which is not very thick in the region, becomes rapidly saturated along rainfall events. Subsequently, the water infiltrates into the rocky layer and the water

  13. An economic assessment of local farm multi-purpose surface water retention systems in a Canadian Prairie setting

    Science.gov (United States)

    Berry, Pamela; Yassin, Fuad; Belcher, Kenneth; Lindenschmidt, Karl-Erich

    2017-12-01

    There is a need to explore more sustainable approaches to water management on the Canadian Prairies. Retention pond installation schemes designed to capture surface water may be a viable option that would reduce water stress during drought periods by providing water for irrigation. The retention systems would serve to capture excess spring runoff and extreme rainfall events, reducing flood potential downstream. Additionally, retention ponds may be used for biomass production and nutrient retention. The purpose of this research was to investigate the economic viability of adopting local farm surface water retention systems as a strategic water management strategy. A retention pond was analyzed using a dynamic simulation model to predict its storage capacity, installation and upkeep cost, and economic advantage to farmers when used for irrigation. While irrigation application increased crop revenue, the cost of irrigation and reservoir infrastructure and installation costs were too high for the farmer to experience a positive net revenue. Farmers who harvest cattails from retention systems for biomass and available carbon offset credits can gain 642.70/hectare of harvestable cattail/year. Cattail harvest also removes phosphorus and nitrogen, providing a monetized impact of 7014/hectare of harvestable cattail/year. The removal of phosphorus, nitrogen, carbon, and avoided flooding damages of the retention basin itself provide an additional 17,730-18,470/hectare of retention system/year. The recommended use of retention systems is for avoided flood damages, nutrient retention, and biomass production. The revenue gained from these functions can support farmers wanting to invest in irrigation while providing economic and environmental benefits to the region.

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

    Science.gov (United States)

    Kennedy, Jeffrey R.; Paretti, Nicholas V.

    2014-01-01

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

  15. GC51D-0831: A Study of the Impact of Dams on Sediment Retention in the Mekong River Basin

    Science.gov (United States)

    Munroe, Thailynn; Griffin, Robert; Anderson, Eric; Markert, Kel

    2017-01-01

    Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. The focus of this study is to utilize the Soil Water Assessment Tool (SWAT), developed at Texas A & M, a rainfall-runoff hydrologic model to determine change in sedimentation in the Mekong Basin after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu & Varis (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

  16. A Study of the Impact of Dams on Streamflow and Sediment Retention in the Mekong River Basin

    Science.gov (United States)

    Munroe, T.; Anderson, E.; Markert, K. N.; Griffin, R.

    2017-12-01

    Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. Current studies that assess the hydrological impact of dams in the region focus on only one or a small subset (SWAT), a rainfall-runoff hydrologic model to determine change in streamflow and sedimentation in the Mekong Basin before and after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

  17. A design study for the isolation of the 281-3H retention basin at the Savannah River Site using the viscous liquid barrier technology

    International Nuclear Information System (INIS)

    Moridis, G.J.; Persoff, P.; Apps, J.; James, A.; Oldenburg, C.; McGrath, A.; Myer, L.; Pellerin, L.; Pruess, K.

    1996-11-01

    This report is a description of the design study for a pilot-scale field demonstration of the Viscous Liquid Barrier (VLB) technology, a new subsurface containment technology for waste isolation using a new generation of barrier liquids. The demonstration site was Retention Basin 281-3H, a shallow catchment basin at the Savannah River Site, which is contaminated mainly by radionuclides ( 137 Cs, 90 Sr, and 238 Pu). The goals of the field demonstration were (a) to demonstrate the ability to create a continuous subsurface barrier in order to isolate the contaminants, and (b) to demonstrate the continuity, performance, and integrity of the barrier. The site was characterized, and preliminary hydraulic conductivity data were obtained from core samples. Based on the site characteristics and the functional requirements, a conceptual model was developed, the barrier specifications were defined, and lance injection was selected as the emplacement method. The injection strategy for the subsurface conditions at the site was determined using numerical simulations. An appropriate variant of Colloidal Silica (CS) was selected as the barrier liquid based on its relative insensitivity to interactions with the site soils, and the formulation for optimum site performance was determined. A barrier verification strategy, including hydraulic, pneumatic, tracer, and geophysical methods, was developed. A lance water injection test was conducted in order to obtain representative estimates of the hydraulic conductivity and its distribution for the design of the barrier emplacement. The water injection test demonstrated the lack of permeable zones for CS injection, and a decision not to proceed with the barrier emplacement was reached

  18. A design study for the isolation of the 281-3H retention basin at the Savannah River Site using the viscous liquid barrier technology

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, G.J.; Persoff, P.; Apps, J.; James, A.; Oldenburg, C.; McGrath, A.; Myer, L.; Pellerin, L.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

    1996-11-01

    This report is a description of the design study for a pilot-scale field demonstration of the Viscous Liquid Barrier (VLB) technology, a new subsurface containment technology for waste isolation using a new generation of barrier liquids. The demonstration site was Retention Basin 281-3H, a shallow catchment basin at the Savannah River Site, which is contaminated mainly by radionuclides ({sup 137}Cs, {sup 90}Sr, and {sup 238}Pu). The goals of the field demonstration were (a) to demonstrate the ability to create a continuous subsurface barrier in order to isolate the contaminants, and (b) to demonstrate the continuity, performance, and integrity of the barrier. The site was characterized, and preliminary hydraulic conductivity data were obtained from core samples. Based on the site characteristics and the functional requirements, a conceptual model was developed, the barrier specifications were defined, and lance injection was selected as the emplacement method. The injection strategy for the subsurface conditions at the site was determined using numerical simulations. An appropriate variant of Colloidal Silica (CS) was selected as the barrier liquid based on its relative insensitivity to interactions with the site soils, and the formulation for optimum site performance was determined. A barrier verification strategy, including hydraulic, pneumatic, tracer, and geophysical methods, was developed. A lance water injection test was conducted in order to obtain representative estimates of the hydraulic conductivity and its distribution for the design of the barrier emplacement. The water injection test demonstrated the lack of permeable zones for CS injection, and a decision not to proceed with the barrier emplacement was reached.

  19. Flood-dominated fluvio-deltaic system: a new depositional model for the Devonian Cabeças Formation, Parnaíba Basin, Piauí, Brazil

    Directory of Open Access Journals (Sweden)

    Luiza Corral M.O. Ponciano

    2009-12-01

    Full Text Available The depositional model of the Cabeças Formation is re-evaluated in the context of the Devonian paleogeography of the Parnaíba Basin, and with particular reference to similarities between the formation's facies associations on the eastern border of the basin and the flood-dominated fluvio-deltaic system facies that have been discussed in recent literature. The widespread occurrence and nature of sigmoidal clinoforms (with asymptotic cross-stratification and climbing ripples of the Cabeças Formation are here considered as strong evidence of flood-influenced depositional settings. Sandy strata of the Passagem Member, in the vicinity of Pimenteiras and Picos (Piauí State, are interpreted as the distal part of fine-grained mouth-bar deposits interbedded with delta-front sandstone lobes showing hummocky cross-stratification. Richly fossiliferous levels, with diverse megainvertebrates and plant cuticles, occur within the delta-front lobes and the distal mouth-bar deposits, reflecting continuation of shallow marine conditions.O modelo deposicional da Formação Cabeças é reinterpretado no presente estudo com base no contexto paleogeográfico da Bacia do Parnaíba durante o Devoniano e na similaridade entre as fácies encontradas na Formação Cabeças com as fácies características dos sistemas flúvio-deltaicos dominados por inundações. O tipo das clinoformas sigmoidais (com estratificação cruzada assintótica e laminação cruzada cavalgante, e a sua predominância na Formação Cabeças, são consideradas como as principais evidências da influência de inundações nesta unidade. Depósitos do Membro Passagem, localizados nos arredores das cidades de Pimenteiras e Picos, são interpretados como o componente distal de um tipo de barra de desembocadura com a predominância de arenitos finos a conglomeráticos, intercalados com lobos arenosos tabulares de frente deltaica com estratificação cruzada hummocky. Diversos intervalos fossil

  20. Glacial Lake Outburst Flood Risk in the Poiqu/Bhote Koshi/Sun Koshi River Basin in the Central Himalayas

    Directory of Open Access Journals (Sweden)

    Narendra Raj Khanal

    2015-11-01

    Full Text Available The Himalayas have experienced several glacial lake outburst floods (GLOFs, and the risk of GLOFs is now increasing in the context of global warming. Poiqu watershed in the Tibet Autonomous Region, China, also known as the Bhote Koshi and Sun Koshi downstream in Nepal, has been identified as highly prone to GLOFs. This study explored the distribution of and changes in glacial lakes, past GLOFs and the resulting losses, risk from potential future GLOFs, and risk reduction initiatives within the watershed. A relationship was established between lake area and volume of lake water based on data from 33 lakes surveyed within the Hindu Kush Himalayan region, and the maximum possible discharge was estimated using this and other previously developed empirical equations. We recommend different strategies to reduce GLOF risk and highlight the need for a glacial lake monitoring and early-warning system. We also recommend strong regional cooperation, especially on issues related to transboundary rivers.

  1. Retention of Afforestation Areas as Part of Flood Protection - Research Site and Methodology for Headwater Watershad in Poland / Retencja Leśna Zlewni Jako Element Ochrony Przeciwpowodziowej

    Science.gov (United States)

    Orczykowski, Tomasz; Tiukało, Andrzej

    2016-03-01

    Land use is considered as a non-structural, ecologically beneficial flood protection measure. Forest as one of the land use types has many useful applications which can be observed in detail on www.nwrm.eu website project. It is scientifically proved that afforestation influences flood events with high probability of occurrence. However, it is still to be argued how to measure land use impact on the hydrological response of watershed and how it should be measured in an efficient and quantifiable way. Having the tool for such an impact measurement, we can build efficient land management strategies. It is difficult to observe the impact of land use on flood events in the field.Therefore, one of the possible solutions is to observe this impact indirectly by means of hydrological rainfall-runoff models as a proxy for the reality. Such experiments were conducted in the past. Our study aims to work on the viability assessment, methodology and tools that allow to observe this impact with use of selected hydrological models and readily available data in Poland. Our first reaserch site is located within headwaters of the Kamienna river watershed. This watershed has been affected by ecological disaster, which resulted in loss of 65% of forest coverage. Our proposed methodology is to observe this transformation and its effect on the watershed response to heavy precipitation and therefore change in the flood risk.

  2. Ecomorphodynamic Response of Foreshore Saltmarsh to the Implementation of Flood and Erosion Mitigation and Adaptation Structures in a Hypertidal Estuary: Minas Basin, Bay of Fundy, Canada.

    Science.gov (United States)

    Matheson, G.; van Proosdij, D.; Ross, C.

    2017-12-01

    Flood and erosion mitigations and adaptation structures are often implemented in anthropogenically modified coastal regions, such as dykelands, to protect against coastal hazards. If saltmarshes are to be incorporated into a coastal management plan as a source of coastal defence, it is paramount to understand how ecomorphodynamic feedbacks triggered by implementing these structures can impact saltmarshes. This study examines how these structures, in combination with natural drivers, have precipitated changes in foreshore saltmarsh erosion and progradation rates over varying spatial scales in the hypertidal Minas Basin, located in the upper Bay of Fundy, during the past 80 years. Foreshore change rates (in 25m segments) are obtained using empirical field measurements, geomatics techniques in a geographical information system (GIS), as well as imagery and digital surface models (DSMs) derived from an unmanned aerial vehicle (UAV). Furthermore, UAV DSMs were used to determine infill rates and short-term sediment budgets in saltmarsh borrow pits. Natural cyclical foreshore change rates are observed in the Minas Basin, but are often augmented by the presence of anthropogenic structures. Erosion and progradation rates in individual transects have been observed to be as much as -14.9m/yr and 20.1m/yr, respectively. In individual saltmarsh communities, average change rates have been observed to be as much -3.4m/yr and 2.1m/yr across the entire foreshore. Furthermore, results suggest that under specific environmental conditions some structures (e.g. kickers) work in tandem with saltmarshes to protect the upland by precipitating ecomorphodynamic feedbacks that promote saltmarsh progradation. Conversely, other structures (e.g. foreshore rocking) can exacerbate natural cycles of erosion, locally. Borrow pit studies reveal that although local suspended sediment concentrations, which can vary from 50mg/l to 50000mg/l, play an integral role in pit sedimentation, channel geometry

  3. In-vessel core debris retention through external flooding of the reactor pressure vessel. SCDAP/RELAP5 assessment for the SBWR lower head

    Energy Technology Data Exchange (ETDEWEB)

    Heel, A.M.J.M. van

    1995-09-01

    In this report the results are discussed from various analyses on the feasibility and phenomenology of the External Flooding (EF) concept for an SBWR lower head, filled with a large heat generating corium mass. In applying External Flooding as an accident management strategy after or during core melt down, the lower drywell is filled with water up to a level where a large portion of the Reactor Pressure Vessel (RPV) is flooded. The purpose of this method is to establish cooling of the vessel wall, that is challenged by the heat load resulting from the corium, in such a way that its structural integrity if not endangered. The analysis discussed in this report focus on the thermal response of the vessel wall and the ex-vessel boiling processes under the conditions described above. For these analyses the SCDAP/REALP5 MOD 3.1 code was used. The major outcome of the calculations is, that a major part of the vessel wall remains well below themelting temperature of carbon steel, as long as flooding of the external surface of the lower head is established. The SCDAP/RELAP5 analyses indicated that low-quality Critical Heat Flux (CHF) was not exceeded, under all the conditions that had been tested. However, a comaprison of the heat fluxes, as calculated in RELAP5, with the CHF values obtained from the Zuber correlation and the Vishnev correction factor (for boiling at inclined surfaces) proved that CHF values, based on these criteria, were exceeded in several surface points of the lower head mesh. The correlations, as resident in the current version of RELAP5 MOD 3.1, might lead to over-estimation of CHF for the EF analyses discussed in this report. The use of the more conservative Zuber correlation with the Vishnev correction factor is recommended for EF analyses. (orig.).

  4. Flood Fighting Products Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — A wave research basin at the ERDC Coastal and Hydraulics Laboratory has been modified specifically for testing of temporary, barrier-type, flood fighting products....

  5. Application of Flood Nomograph for Flood Forecasting in Urban Areas

    Directory of Open Access Journals (Sweden)

    Eui Hoon Lee

    2018-01-01

    Full Text Available Imperviousness has increased due to urbanization, as has the frequency of extreme rainfall events by climate change. Various countermeasures, such as structural and nonstructural measures, are required to prepare for these effects. Flood forecasting is a representative nonstructural measure. Flood forecasting techniques have been developed for the prevention of repetitive flood damage in urban areas. It is difficult to apply some flood forecasting techniques using training processes because training needs to be applied at every usage. The other flood forecasting techniques that use rainfall data predicted by radar are not appropriate for small areas, such as single drainage basins. In this study, a new flood forecasting technique is suggested to reduce flood damage in urban areas. The flood nomograph consists of the first flooding nodes in rainfall runoff simulations with synthetic rainfall data at each duration. When selecting the first flooding node, the initial amount of synthetic rainfall is 1 mm, which increases in 1 mm increments until flooding occurs. The advantage of this flood forecasting technique is its simple application using real-time rainfall data. This technique can be used to prepare a preemptive response in the process of urban flood management.

  6. Best management practices for nutrient and sediment retention in urban stormwater runoff.

    Science.gov (United States)

    Hogan, Dianna M; Walbridge, Mark R

    2007-01-01

    Stormwater management infrastructure is utilized in urban areas to alleviate flooding caused by decreased landscape permeability from increased impervious surface cover (ISC) construction. In this study, we examined two types of stormwater detention basins, SDB-BMPs (stormwater detention basin-best management practice), and SDB-FCs (stormwater detention basin-flood control). Both are constructed to retain peak stormwater flows for flood mitigation. However, the SDB-BMPs are also designed using basin topography and wetland vegetation to provide water quality improvement (nutrient and sediment removal and retention). The objective of this study was to compare SDB (both SDB-BMP and SDB-FC) surface soil P concentrations, P saturation, and Fe chemistry with natural riparian wetlands (RWs), using sites in Fairfax County, Virginia as a model system. The SDB-BMPs had significantly greater surface soil total P (P(t)) concentrations than the RWs and SDB-FCs (831.9 +/- 32.5 kg ha(-1), 643.3 +/- 19.1 kg ha(-1), and 652.1 +/- 18.8 kg ha(-1), respectively). The soil P sorption capacities of SDB-BMPs were similar to the RWs, and were greater than those of SDB-FCs, appearing to result in greater soil P removal and retention in SDB-BMPs compared with SDB-FCs. Increased Fe concentrations and relatively greater amounts of more crystalline forms of Fe in SDB-BMP soils suggested increased sediment deposition compared with RW and SDB-FC soils. Data suggest that SDB nutrient and sediment retention is facilitated in SDB-BMPs. When stormwater management is necessary, use of SDB-BMPs instead of SDB-FCs could foster more responsible urban development and be an appropriate mitigation action for receiving aquatic ecosystems.

  7. Climatic and basin factors affecting the flood frequency curve: PART II – A full sensitivity analysis based on the continuous simulation approach combined with a factorial experimental design

    Directory of Open Access Journals (Sweden)

    M. Franchini

    2000-01-01

    Full Text Available The sensitivity analysis described in Hashemi et al. (2000 is based on one-at-a-time perturbations to the model parameters. This type of analysis cannot highlight the presence of parameter interactions which might indeed affect the characteristics of the flood frequency curve (ffc even more than the individual parameters. For this reason, the effects of the parameters of the rainfall, rainfall runoff models and of the potential evapotranspiration demand on the ffc are investigated here through an analysis of the results obtained from a factorial experimental design, where all the parameters are allowed to vary simultaneously. This latter, more complex, analysis confirms the results obtained in Hashemi et al. (2000 thus making the conclusions drawn there of wider validity and not related strictly to the reference set selected. However, it is shown that two-factor interactions are present not only between different pairs of parameters of an individual model, but also between pairs of parameters of different models, such as rainfall and rainfall-runoff models, thus demonstrating the complex interaction between climate and basin characteristics affecting the ffc and in particular its curvature. Furthermore, the wider range of climatic regime behaviour produced within the factorial experimental design shows that the probability distribution of soil moisture content at the storm arrival time is no longer sufficient to explain the link between the perturbations to the parameters and their effects on the ffc, as was suggested in Hashemi et al. (2000. Other factors have to be considered, such as the probability distribution of the soil moisture capacity, and the rainfall regime, expressed through the annual maximum rainfalls over different durations. Keywords: Monte Carlo simulation; factorial experimental design; analysis of variance (ANOVA

  8. Assessment of the costs, risks and benefits of selected integrated policy options to adapt to flood and drought in the water and agricultural sectors of the Warta River Basin

    Science.gov (United States)

    Sendzimir, Jan; Dubel, Anna; Linnerooth-Bayer, Joanne; Damurski, Jakub; Schroeter, Dagmar

    2014-05-01

    Historically large reservoirs have been the dominant strategy to counter flood and drought risk in Europe. However, a number of smaller-scale approaches have emerged as alternative strategies. To compare the cost effectiveness of reservoirs and these alternatives, we calculated the Investment & maintenance costs in terms of (euros) /m3 water stored or annual runoff reduced for five different strategies: large reservoirs (1.68 euros), large on-farm ponds (5.88 euros), small on-farm ponds (558.00 euros), shelterbelts (6.86 euros), switching to conservation tillage (-9.20 euros). The most cost effective measure for reducing runoff is switching to conservation tillage practices because this switch reduces machinery and labor costs in addition to reducing water runoff. Although shelterbelts that reduce annual runoff cannot be directly compared to ponds and reservoirs that store water, our estimates show that they likely compare favorably as a natural water retention measure, especially when taking account of their co-benefits in terms of erosion control, biodiversity and pollination. Another useful result is our demonstration of the economies of scale among reservoirs and ponds for storing water. Small ponds are two orders of magnitude more costly to construct and maintain as a flood and drought prevention measure than large reservoirs. Here, again, there are large co-benefits that should be factored into the cost-benefit equation, including especially the value of small ponds in promoting corridors for migration. This analysis shows the importance of carrying out more extensive cost-benefit estimates across on-farm and off-farm measures for tackling drought and flood risk in the context of a changing climate. While concrete recommendations for supporting water retention measures will depend on a more detailed investigation of their costs and benefits, this research highlights the potential of natural water retention measures as a complement to conventional investments

  9. Technical note Flood map development by coupling satellite maps ...

    African Journals Online (AJOL)

    Flood maps are important for local authorities in designing mitigation plans to minimise damage and loss due to flooding. In recent years, flood events in the Sarawak River Basin, Malaysia have caused damage to property, loss of life and disruption of productive activities. Currently, the available flood map for Sarawak River ...

  10. Flash-flood potential assessment and mapping by integrating the ...

    Indian Academy of Sciences (India)

    Romulus Costache

    2017-06-16

    Jun 16, 2017 ... A basic step in flood risk management is identifying areas susceptible to flood occurrences. This paper proposes a methodology ... river channels and flood wave propagation from the upper area of the basin to the lower ... to improve the quality of flash-flood forecasts. Four geographical variables (slope ...

  11. Polders as active element of flood control

    International Nuclear Information System (INIS)

    Zilavy, M.

    2004-01-01

    In this presentation author deals with use of the polders as active element of flood control on the example Kysuca River and Podluzianka River (Slovakia). It was concluded that it is necessary: - dense network of rain gauge stations; - network of water level recorders; revision of design process for hydraulic objects - degree of safety; changes in legislation - permission for construction in flood-plains; maintenance of channel capacity; early flood forecasting - forecasting and warning service; river training works and maintenance; design of retention areas; preparation of retention areas prior to flood propagation

  12. Raptor habitat use in the Lake Chad Basin : Insights into the effect of flood-plain transformation on Afrotropical and Palearctic raptors

    NARCIS (Netherlands)

    Buij, Ralph; Croes, Barbara M.

    West African flood-plains have undergone major land-use transformations in the second half of the 20th century. To obtain insight in the effect of flood-plain development for irrigated rice cultivation on the abundance, richness, and diversity of Palearctic and Afrotropical raptors, we conducted

  13. Raptor habitat use in the lake Chad basin: insights into the effect of flood-plain transformation on afrotropical and paleartic raptors

    NARCIS (Netherlands)

    Buij, R.; Croes, B.M.

    2013-01-01

    West African flood-plains have undergone major land-use transformations in the second half of the 20th century. To obtain insight in the effect of flood-plain development for irrigated rice cultivation on the abundance, richness, and diversity of Palearctic and Afrotropical raptors, we conducted

  14. Water quality of the Apalachicola-Chattahoochee-Flint and Ocmulgee river basins related to flooding from Tropical Storm Alberto; pesticides in urban and agricultural watersheds, and nitrate and pesticides in ground water, Georgia, Alabama, and Florida

    Science.gov (United States)

    Hippe, D.J.; Wangsness, D.J.; Frick, E.A.; Garrett, J.W.

    1994-01-01

    This report presents preliminary water-quality information from three studies that are part of the National Water-Quality Assessment (NAWQA) Program in the Apalachicola-Chattahoochee-Flint (ACF) River basin and the adjacent Ocmulgee River basin. During the period July 3-7, 1994, heavy rainfall from tropical storm Alberto caused record flooding on the Ocmulgee and Flint Rivers and several of their tributaries. Much of the nitrogen load transported during the flooding was as organic nitrogen generally derived from organic detritus, rather than nitrate derived from other sources, such as fertilizer. More than half the mean annual loads of total phosphorus and organic nitrogen were trans- ported in the Flint and Ocmulgee Rivers during the flood. Fourteen herbicides, five insecticides, and one fungicide were detected in floodwaters of the Ocmulgee, Flint, and Apalachicola Rivers. In a second study, water samples were collected at nearly weekly intervals from March 1993 through April 1994 from one urban and two agricultural watersheds in the ACF River basin, and analyzed for 84 commonly used pesticides. More pesticides were detected and at generally higher concentrations in water from the urban watershed than the agricultural water- sheds, and a greater number of pesticides were persistent throughout much of the year in the urban watershed. Simazine exceeded U.S. Environmental Protection Agency (EPA) drinking-water standards in one of 57 samples from the urban watershed. In a third study, 38 wells were installed in surficial aquifers adjacent to and downgradient of farm fields within agricultural areas in the southern ACF River basin. Even though regional aquifers are generally used for irrigation and domestic- and public-water supplies, degradation of water quality in the surficial aquifers serves as an early warning of potential contamination of regional aquifers. Nitrate concentrations were less than 3 mg/L as N (indicating minimal effect of human activities) in water

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

    Science.gov (United States)

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

    2012-09-01

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

  16. High temporal resolution modeling of the impact of rain, tides, and sea level rise on water table flooding in the Arch Creek basin, Miami-Dade County Florida USA.

    Science.gov (United States)

    Sukop, Michael C; Rogers, Martina; Guannel, Greg; Infanti, Johnna M; Hagemann, Katherine

    2018-03-01

    Modeling of groundwater levels in a portion of the low-lying coastal Arch Creek basin in northern Miami-Dade County in Southeast Florida USA, which is subject to repetitive flooding, reveals that rain-induced short-term water table rises can be viewed as a primary driver of flooding events under current conditions. Areas below 0.9m North American Vertical Datum (NAVD) elevation are particularly vulnerable and areas below 1.5m NAVD are vulnerable to exceptionally large rainfall events. Long-term water table rise is evident in the groundwater data, and the rate appears to be consistent with local rates of sea level rise. Linear extrapolation of long-term observed groundwater levels to 2060 suggest roughly a doubling of the number of days when groundwater levels exceed 0.9m NAVD and a threefold increase in the number of days when levels exceed 1.5m NAVD. Projected sea level rise of 0.61m by 2060 together with increased rainfall lead to a model prediction of frequent groundwater-related flooding in areas1.5m NAVD and widespread flooding of the area in the past. Tidal fluctuations in the water table are predicted to be more pronounced within 600m of a tidally influenced water control structure that is hydrodynamically connected to Biscayne Bay. The inland influence of tidal fluctuations appears to increase with increased sea level, but the principal driver of high groundwater levels under the 2060 scenario conditions remains groundwater recharge due to rainfall events. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. An Integrated Ensemble-Based Operational Framework to Predict Urban Flooding: A Case Study of Hurricane Sandy in the Passaic and Hackensack River Basins

    Science.gov (United States)

    Saleh, F.; Ramaswamy, V.; Georgas, N.; Blumberg, A. F.; Wang, Y.

    2016-12-01

    Advances in computational resources and modeling techniques are opening the path to effectively integrate existing complex models. In the context of flood prediction, recent extreme events have demonstrated the importance of integrating components of the hydrosystem to better represent the interactions amongst different physical processes and phenomena. As such, there is a pressing need to develop holistic and cross-disciplinary modeling frameworks that effectively integrate existing models and better represent the operative dynamics. This work presents a novel Hydrologic-Hydraulic-Hydrodynamic Ensemble (H3E) flood prediction framework that operationally integrates existing predictive models representing coastal (New York Harbor Observing and Prediction System, NYHOPS), hydrologic (US Army Corps of Engineers Hydrologic Modeling System, HEC-HMS) and hydraulic (2-dimensional River Analysis System, HEC-RAS) components. The state-of-the-art framework is forced with 125 ensemble meteorological inputs from numerical weather prediction models including the Global Ensemble Forecast System, the European Centre for Medium-Range Weather Forecasts (ECMWF), the Canadian Meteorological Centre (CMC), the Short Range Ensemble Forecast (SREF) and the North American Mesoscale Forecast System (NAM). The framework produces, within a 96-hour forecast horizon, on-the-fly Google Earth flood maps that provide critical information for decision makers and emergency preparedness managers. The utility of the framework was demonstrated by retrospectively forecasting an extreme flood event, hurricane Sandy in the Passaic and Hackensack watersheds (New Jersey, USA). Hurricane Sandy caused significant damage to a number of critical facilities in this area including the New Jersey Transit's main storage and maintenance facility. The results of this work demonstrate that ensemble based frameworks provide improved flood predictions and useful information about associated uncertainties, thus

  18. Restoring the Mississippi River Basin from the Catchment to the Coast Defines Science and Policy Issues of Ecosystem Services Associated with Alluvial and Coastal Deltaic Floodplains: Soil Conservation, Nutrient Reduction, Carbon Sequestration, and Flood Control

    Science.gov (United States)

    Twilley, R.

    2014-12-01

    Large river systems are major economic engines that provide national economic wealth in transporting commerce and providing extensive agriculture production, and their coastal deltas are sites of significant ports, energy resources and fisheries. These coupled natural and social systems from the catchment to the coast depend on how national policies manage the river basins that they depend. The fundamental principle of the Mississippi River Basin, as in all basins, is to capitalize on the ability of fertile soil that moves from erosional regions of a large watershed, through downstream regions of the catchment where sediment transport and storage builds extensive floodplains, to the coastal region of deposition where deltas capture sediment and nutrients before exported to the oceans. The fate of soil, and the ability of that soil to do work, supports the goods and services along its path from the catchment to the coast in all large river basin and delta systems. Sediment is the commodity of all large river basin systems that together with the seasonal pulse of floods across the interior of continents provide access to the sea forming the assets that civilization and economic engines have tapped to build national and global wealth. Coastal landscapes represent some of the most altered ecosystems worldwide and often integrate the effects of processes over their entire catchment, requiring systemic solutions to achieve restoration goals from alluvial floodplains upstream to coastal deltaic floodplains downstream. The urgent need for wetland rehabilitation at landscape scales has been initiated through major floodplain reclamation and hydrologic diversions to reconnect the river with wetland processes. But the constraints of sediment delivery and nutrient enrichment represent some critical conflicts in earth surface processes that limit the ability to design 'self sustaining' public work projects; particularly with the challenges of accelerated sea level rise. Only

  19. Timetable of an operational flood forecasting system

    Science.gov (United States)

    Liechti, Katharina; Jaun, Simon; Zappa, Massimiliano

    2010-05-01

    At present a new underground part of Zurich main station is under construction. For this purpose the runoff capacity of river Sihl, which is passing beneath the main station, is reduced by 40%. If a flood is to occur the construction site is evacuated and gates can be opened for full runoff capacity to prevent bigger damages. However, flooding the construction site, even if it is controlled, is coupled with costs and retardation. The evacuation of the construction site at Zurich main station takes about 2 to 4 hours and opening the gates takes another 1 to 2 hours each. In the upper part of the 336 km2 Sihl catchment the Sihl lake, a reservoir lake, is situated. It belongs and is used by the Swiss Railway Company for hydropower production. This lake can act as a retention basin for about 46% of the Sihl catchment. Lowering the lake level to gain retention capacity, and therewith safety, is coupled with direct loss for the Railway Company. To calculate the needed retention volume and the water to be released facing unfavourable weather conditions, forecasts with a minimum lead time of 2 to 3 days are needed. Since the catchment is rather small, this can only be realised by the use of meteorological forecast data. Thus the management of the construction site depends on accurate forecasts to base their decisions on. Therefore an operational hydrological ensemble prediction system (HEPS) was introduced in September 2008 by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL). It delivers daily discharge forecasts with a time horizon of 5 days. The meteorological forecasts are provided by MeteoSwiss and stem from the operational limited-area COSMO-LEPS which downscales the ECMWF ensemble prediction system to a spatial resolution of 7 km. Additional meteorological data for model calibration and initialisation (air temperature, precipitation, water vapour pressure, global radiation, wind speed and sunshine duration) and radar data are also provided by

  20. Detention basin alternative outlet design study.

    Science.gov (United States)

    2016-10-01

    This study examines the outlets structures CDOT has historically employed to drain water quality treatment detention basins and flood control basins, presents two new methods of metering the water quality capture volume (WQCV), namely 1) the Elliptic...

  1. LATERAL FLOODING ASSOCIATED TO WAVE FLOOD GENERATION ON RIVER SURFACE

    Directory of Open Access Journals (Sweden)

    C. Ramírez-Núñez

    2016-06-01

    Full Text Available This research provides a wave flood simulation using a high resolution LiDAR Digital Terrain Model. The simulation is based on the generation of waves of different amplitudes that modify the river level in such a way that water invades the adjacent areas. The proposed algorithm firstly reconstitutes the original river surface of the studied river section and then defines the percentage of water loss when the wave floods move downstream. This procedure was applied to a gently slope area in the lower basin of Coatzacoalcos river, Veracruz (Mexico defining the successive areas where lateral flooding occurs on its downstream movement.

  2. Lateral Flooding Associated to Wave Flood Generation on River Surface

    Science.gov (United States)

    Ramírez-Núñez, C.; Parrot, J.-F.

    2016-06-01

    This research provides a wave flood simulation using a high resolution LiDAR Digital Terrain Model. The simulation is based on the generation of waves of different amplitudes that modify the river level in such a way that water invades the adjacent areas. The proposed algorithm firstly reconstitutes the original river surface of the studied river section and then defines the percentage of water loss when the wave floods move downstream. This procedure was applied to a gently slope area in the lower basin of Coatzacoalcos river, Veracruz (Mexico) defining the successive areas where lateral flooding occurs on its downstream movement.

  3. Estimating Agricultural Losses using Flood Modeling for Rural Area

    Directory of Open Access Journals (Sweden)

    Muhadi Nur Atirah

    2017-01-01

    Full Text Available Flooding is the most significant natural hazard in Malaysia in terms of population affected, frequency, flood extent, flood duration and social economic damage. Flooding causes loss of lives, injuries, property damage and leave some economic damage to the country especially when it occurs in a rural area where the main income is dependent on agricultural area. This study focused on flooding in oil palm plantations, rubber plantations and fruits and vegetables area. InfoWorks ICM was used to develop a flood model to study the impact of flooding and to mitigate the floods using a retention pond. Later, Geographical Information System (GIS together with the flood model were used for the analysis on flood damage assessment and management of flood risk. The estimated total damage for three different flood event; 10 ARI, 50 ARI and 100 ARI involved millions of ringgits. In reducing the flood impact along the Selangor River, retention pond was suggested, modeled and tested. By constructing retention pond, flood extents in agricultural area were reduced significantly by 60.49% for 10 ARI, 45.39% for 50 ARI and 46.54% for 100 ARI.

  4. Recent advances in flood forecasting and flood risk assessment

    Directory of Open Access Journals (Sweden)

    G. Arduino

    2005-01-01

    Full Text Available Recent large floods in Europe have led to increased interest in research and development of flood forecasting systems. Some of these events have been provoked by some of the wettest rainfall periods on record which has led to speculation that such extremes are attributable in some measure to anthropogenic global warming and represent the beginning of a period of higher flood frequency. Whilst current trends in extreme event statistics will be difficult to discern, conclusively, there has been a substantial increase in the frequency of high floods in the 20th century for basins greater than 2x105 km2. There is also increasing that anthropogenic forcing of climate change may lead to an increased probability of extreme precipitation and, hence, of flooding. There is, therefore, major emphasis on the improvement of operational flood forecasting systems in Europe, with significant European Community spending on research and development on prototype forecasting systems and flood risk management projects. This Special Issue synthesises the most relevant scientific and technological results presented at the International Conference on Flood Forecasting in Europe held in Rotterdam from 3-5 March 2003. During that meeting 150 scientists, forecasters and stakeholders from four continents assembled to present their work and current operational best practice and to discuss future directions of scientific and technological efforts in flood prediction and prevention. The papers presented at the conference fall into seven themes, as follows.

  5. A rainfall design method for spatial flood risk assessment: considering multiple flood sources

    Science.gov (United States)

    Jiang, X.; Tatano, H.

    2015-08-01

    Information about the spatial distribution of flood risk is important for integrated urban flood risk management. Focusing on urban areas, spatial flood risk assessment must reflect all risk information derived from multiple flood sources: rivers, drainage, coastal flooding etc. that may affect the area. However, conventional flood risk assessment deals with each flood source independently, which leads to an underestimation of flood risk in the floodplain. Even in floodplains that have no risk from coastal flooding, flooding from river channels and inundation caused by insufficient drainage capacity should be considered simultaneously. For integrated flood risk management, it is necessary to establish a methodology to estimate flood risk distribution across a floodplain. In this paper, a rainfall design method for spatial flood risk assessment, which considers the joint effects of multiple flood sources, is proposed. The concept of critical rainfall duration determined by the concentration time of flooding is introduced to connect response characteristics of different flood sources with rainfall. A copula method is then adopted to capture the correlation of rainfall amount with different critical rainfall durations. Rainfall events are designed taking advantage of the copula structure of correlation and marginal distribution of rainfall amounts within different critical rainfall durations. A case study in the Otsu River Basin, Osaka prefecture, Japan was conducted to demonstrate this methodology.

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

    Science.gov (United States)

    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.

  7. An empirical method for estimating future flood risks for flood warnings

    Directory of Open Access Journals (Sweden)

    H. Hlavcova

    2005-01-01

    Full Text Available Since medium and long-term precipitation forecasts are still not reliable enough, rough estimates of the degree of the extremity of forthcoming flood events that might occur in the course of dangerous meteorological situations approaching a basin could be useful to decision-makers as additional information for flood warnings. One approach to answering such a problem is to use real-time data on the soil moisture conditions in a catchment in conjunction with estimates of the extremity of the future rainfall and experience with the basin's behaviour during historical floods. A scenario-based method is proposed for such a future flood risk estimation, based on an a priori evaluation of the extremity of hypothetical floods generated by combinations of synthetic extreme precipitation and previously observed antecedent pre-flood basin saturations. The Hron river basin, located in central Slovakia, was chosen as the pilot basin in the case study. A time series of the basin's average daily precipitation was derived using spatial interpolation techniques. A lumped HBV-type daily conceptual rainfall-runoff model was adopted for modelling runoff. Analysis of the relationship of the modelled historical pre-flood soil moisture and flood causing-precipitation revealed the independence of both quantities for rainfall durations lasting 1 to 5 days. The basin's average annual maximum 1 to 5 day precipitation depths were analysed statistically and synthetic extreme precipitation scenarios associated with rainfall depths with return periods of 5, 20, 50 and 100 years, durations of 1 to 5 days and temporal distribution of extreme rainfall observed in the past were set up for runoff simulation. Using event-based flood simulations, synthetic flood waves were generated for random combinations of the rainfall scenarios and historical pre-flood soil moisture conditions. The effect of any antecedent basin saturation on the extremity of floods was quantified empirically

  8. Swiss Re Global Flood Hazard Zones: Know your flood risk

    Science.gov (United States)

    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.

  9. THE 05.06.2012 SLOPE FLOOD RUNOFF IN THE LOWER BASIN OF ILIŞUA RIVER – CAUSES, EFFECTS AND FUTURE MEASURES

    Directory of Open Access Journals (Sweden)

    Gh. Şerban

    2013-03-01

    Full Text Available In the context of the Code Yellow for rainfalls and storms, issued by National Administration of Meteorology (NAM, a downpoor occurred on the 5th of June 2012 in the afternoon, between 16.00 and 16.30 hours, with maximum intensity in the area of the Dobric – Dobricel – Spermezeu – Păltineasa – Dumbrăviţa – Căianu Mare – Căianu Mic localities. The extreme meteorological event has caused a severe slope runoff. Fortunately, the effects did not include any victims, although they were very severe, judging by the blocking of tens of kilometres of road, the flooding of almost 200 households and several hundreds of hectares of agricultural land. The risk map showing the occurrence distribution of slope flood runoff and associate meteorological events reveals the need of implementing strict measures consisting in: partial afforestation of the two thirds of the cleared slopes, management and diversion of floods that discharge their liquid and alluvial material over the human settlements located in the closest proximity of the slopes, resizing of the access infrastructure (bridges, footbridges and flood defence infrastructure (dams, runoff drainage system, scenario-based training of population to react promptly to the development of the extreme hydrometeorological events. On the contrary, the questionnaires applied in the study area reveal a lower preparedness level of the population for an efficient, optimum reaction, in order to significantly reduce the effects of these phenomena.

  10. The influence of snow cover on alpine floods reconstructed from the analysis of satellite images. The case of the Hasli-Aare river basin, Berner Oberland (1987-2012)

    Science.gov (United States)

    Cabrera-Medina, Paula; Schulte, Lothar; Carvalho, Filipe; Peña, Juan Carlos; García, Carles

    2016-04-01

    Regarding the hydrological hazards in the Hasli-Aare river over the last century, instrumental and documentary data show that flood frequency and magnitude increased since 1977. One of the main water inputs contributing to peak discharges is given by the thaw of the stored snow. Therefore, the knowledge of the evolution of snow cover is considered essential for the assessment of alpine floods. Snow cover studies can be made by different approaches such as the analysis of data provided by field work or by nivometeorological stations. However, these methods are usually expensive and do not present adequate spatial or temporal coverage data. For this reason, satellite images with different spatial and temporal resolution are an interesting complementary source for the understanding of the snow cover dynamics. The aim of the paper is to study the influence of snow cover variations during years of severe floods that occurred in the upper Aare basin from 1987 to 2012. Three satellite images have been selected for each of the 9 studied events: 1) maximum snow cover during winter, 2) the last image before the event and 3) the first image after the flood. Each image has been processed with the ArcGIS software applying a statistical method of supervised classification. This image processing allows the spatial quantification of the variation of the snow cover in the Aare headwater catchment. Because the melting of snow cover is related to the changes of weather situations before and during the flood episode, it is important to analyse also the nivometeorological data of stations located in the catchment (snow depth, temperature and precipitation). From these data we determined 4 types of flood, which can be classified according to their nivometeorological variables and synoptic situation (500 hPa geopotential and Sea Level Pressure) into two patterns. The first group of events can be associated to an Atlantic pattern recording decreasing temperatures, moderate to high

  11. Validating quantitative precipitation forecast for the Flood ...

    Indian Academy of Sciences (India)

    In order to issue an accurate warning for flood, a better or appropriate quantitative forecasting of pre- cipitation is required. In view of this, the present study intends to validate the quantitative precipita- tion forecast (QPF) issued during southwest monsoon season for six river catchments (basin) under the flood meteorological ...

  12. Mitigating flood exposure

    Science.gov (United States)

    Shultz, James M; McLean, Andrew; Herberman Mash, Holly B; Rosen, Alexa; Kelly, Fiona; Solo-Gabriele, Helena M; Youngs Jr, Georgia A; Jensen, Jessica; Bernal, Oscar; Neria, Yuval

    2013-01-01

    Introduction. In 2011, following heavy winter snowfall, two cities bordering two rivers in North Dakota, USA faced major flood threats. Flooding was foreseeable and predictable although the extent of risk was uncertain. One community, Fargo, situated in a shallow river basin, successfully mitigated and prevented flooding. For the other community, Minot, located in a deep river valley, prevention was not possible and downtown businesses and one-quarter of the homes were inundated, in the city’s worst flood on record. We aimed at contrasting the respective hazards, vulnerabilities, stressors, psychological risk factors, psychosocial consequences, and disaster risk reduction strategies under conditions where flood prevention was, and was not, possible. Methods. We applied the “trauma signature analysis” (TSIG) approach to compare the hazard profiles, identify salient disaster stressors, document the key components of disaster risk reduction response, and examine indicators of community resilience. Results. Two demographically-comparable communities, Fargo and Minot, faced challenging river flood threats and exhibited effective coordination across community sectors. We examined the implementation of disaster risk reduction strategies in situations where coordinated citizen action was able to prevent disaster impact (hazard avoidance) compared to the more common scenario when unpreventable disaster strikes, causing destruction, harm, and distress. Across a range of indicators, it is clear that successful mitigation diminishes both physical and psychological impact, thereby reducing the trauma signature of the event. Conclusion. In contrast to experience of historic flooding in Minot, the city of Fargo succeeded in reducing the trauma signature by way of reducing risk through mitigation. PMID:28228985

  13. Risk Analysis of Reservoir Operations Considering Short-Term Flood Control and Long-Term Water Supply: A Case Study for the Da-Han Creek Basin in Taiwan

    Directory of Open Access Journals (Sweden)

    Wen-Ming Cheng

    2017-06-01

    Full Text Available This study applies an integrated methodology to assess short-term over-levee risk and long-term water shortage risk in the Da-Han Creek basin, which is the most important flood control and water storage system in northern Taiwan. An optimization model for reservoir flood control and water supply is adopted, to determine reservoir releases based on synthetic inflow hydrographs during typhoons, which are generated by Monte Carlo simulations. The release is then used to calculate the water level at a downstream control point using a novel developed back-propagation neural network-based model, to reduce computational complexity and achieve automatic-efficient risk evaluation. The calculated downstream water levels and final reservoir water levels after a typhoon event are used to evaluate the mapped over-levee risk and water shortage risk, respectively. The results showed that the different upper limit settings for the reservoir have a significant influence on the variation of 1.19 × 10−5% to 75.6% of the water shortage risk. This occurs because of the insufficient inflow and narrow storage capacity of the Shih-Men Reservoir during drought periods. However, the upper limit settings have a minor influence (with a variation of only 0.149% to 0.157% on the over-levee risk in typhoon periods, because of the high protection standards for the downstream embankment.

  14. Comparing flood loss models of different complexity

    Science.gov (United States)

    Schröter, Kai; Kreibich, Heidi; Vogel, Kristin; Riggelsen, Carsten; Scherbaum, Frank; Merz, Bruno

    2013-04-01

    Any deliberation on flood risk requires the consideration of potential flood losses. In particular, reliable flood loss models are needed to evaluate cost-effectiveness of mitigation measures, to assess vulnerability, for comparative risk analysis and financial appraisal during and after floods. In recent years, considerable improvements have been made both concerning the data basis and the methodological approaches used for the development of flood loss models. Despite of that, flood loss models remain an important source of uncertainty. Likewise the temporal and spatial transferability of flood loss models is still limited. This contribution investigates the predictive capability of different flood loss models in a split sample cross regional validation approach. For this purpose, flood loss models of different complexity, i.e. based on different numbers of explaining variables, are learned from a set of damage records that was obtained from a survey after the Elbe flood in 2002. The validation of model predictions is carried out for different flood events in the Elbe and Danube river basins in 2002, 2005 and 2006 for which damage records are available from surveys after the flood events. The models investigated are a stage-damage model, the rule based model FLEMOps+r as well as novel model approaches which are derived using data mining techniques of regression trees and Bayesian networks. The Bayesian network approach to flood loss modelling provides attractive additional information concerning the probability distribution of both model predictions and explaining variables.

  15. Morphometric factors as conditioning variables in the occurrence of floods in the Serafim Stream basin, subbasin of the Paraibuna River, Juiz de Fora, MG

    OpenAIRE

    Raquel Callegario Zacchi; Maola Monique de Faria; Elaine Santiago Ferreira

    2013-01-01

    As they encourage the monitoring of natural changes introduced by man such as soil use and occupation, basins should be considered as planning units because they allow for the monitoring of their activities in order to preserve natural resources. This study aims to characterize the watershed of the Serafim Stream, subbasin of the Paraibuna River, located in Juiz de Fora, MG, regarding its morphometric features. To do this, it was necessary to limit the basin area inserted in the map by IBGE (...

  16. Flood Risk and Flood hazard maps - Visualisation of hydrological risks

    International Nuclear Information System (INIS)

    Spachinger, Karl; Dorner, Wolfgang; Metzka, Rudolf; Serrhini, Kamal; Fuchs, Sven

    2008-01-01

    Hydrological models are an important basis of flood forecasting and early warning systems. They provide significant data on hydrological risks. In combination with other modelling techniques, such as hydrodynamic models, they can be used to assess the extent and impact of hydrological events. The new European Flood Directive forces all member states to evaluate flood risk on a catchment scale, to compile maps of flood hazard and flood risk for prone areas, and to inform on a local level about these risks. Flood hazard and flood risk maps are important tools to communicate flood risk to different target groups. They provide compiled information to relevant public bodies such as water management authorities, municipalities, or civil protection agencies, but also to the broader public. For almost each section of a river basin, run-off and water levels can be defined based on the likelihood of annual recurrence, using a combination of hydrological and hydrodynamic models, supplemented by an analysis of historical records and mappings. In combination with data related to the vulnerability of a region risk maps can be derived. The project RISKCATCH addressed these issues of hydrological risk and vulnerability assessment focusing on the flood risk management process. Flood hazard maps and flood risk maps were compiled for Austrian and German test sites taking into account existing national and international guidelines. These maps were evaluated by eye-tracking using experimental graphic semiology. Sets of small-scale as well as large-scale risk maps were presented to test persons in order to (1) study reading behaviour as well as understanding and (2) deduce the most attractive components that are essential for target-oriented risk communication. A cognitive survey asking for negative and positive aspects and complexity of each single map complemented the experimental graphic semiology. The results indicate how risk maps can be improved to fit the needs of different user

  17. Flood Risk and Flood hazard maps - Visualisation of hydrological risks

    Science.gov (United States)

    Spachinger, Karl; Dorner, Wolfgang; Metzka, Rudolf; Serrhini, Kamal; Fuchs, Sven

    2008-11-01

    Hydrological models are an important basis of flood forecasting and early warning systems. They provide significant data on hydrological risks. In combination with other modelling techniques, such as hydrodynamic models, they can be used to assess the extent and impact of hydrological events. The new European Flood Directive forces all member states to evaluate flood risk on a catchment scale, to compile maps of flood hazard and flood risk for prone areas, and to inform on a local level about these risks. Flood hazard and flood risk maps are important tools to communicate flood risk to different target groups. They provide compiled information to relevant public bodies such as water management authorities, municipalities, or civil protection agencies, but also to the broader public. For almost each section of a river basin, run-off and water levels can be defined based on the likelihood of annual recurrence, using a combination of hydrological and hydrodynamic models, supplemented by an analysis of historical records and mappings. In combination with data related to the vulnerability of a region risk maps can be derived. The project RISKCATCH addressed these issues of hydrological risk and vulnerability assessment focusing on the flood risk management process. Flood hazard maps and flood risk maps were compiled for Austrian and German test sites taking into account existing national and international guidelines. These maps were evaluated by eye-tracking using experimental graphic semiology. Sets of small-scale as well as large-scale risk maps were presented to test persons in order to (1) study reading behaviour as well as understanding and (2) deduce the most attractive components that are essential for target-oriented risk communication. A cognitive survey asking for negative and positive aspects and complexity of each single map complemented the experimental graphic semiology. The results indicate how risk maps can be improved to fit the needs of different user

  18. The land morphology approach to flood risk mapping: An application to Portugal.

    Science.gov (United States)

    Cunha, N S; Magalhães, M R; Domingos, T; Abreu, M M; Küpfer, C

    2017-05-15

    metropolitan area, an urbanized basin that suffered heavy flooding in the last decades. This study also contributes to a better understanding of the basin morphology at a local-scale and the effects of soil sealing in downstream flood risks. This work will contribute to the understanding of the morphology, ecology and land use of watersheds that could be used to reduce runoff and downstream flood risk. This can be accomplished by using natural water retention and infiltration methods or higher-level based planning instead of a reaction to local decisions on flood hazards. This morphological approach to map landforms, including wet system, is a valuable tool to assist policy makers and planners in flood risk and land use management, floodplain restoration, agricultural land management practices, and location of human activities according to ecological suitability. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    BORCAN MIHAELA

    2014-03-01

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

  20. Adapting flood preparedness tools to changing flood risk conditions: the situation in Poland⁎ The preparation of this paper was funded from the EU FP7 STAR-FLOOD Project (STrengthening And Redesigning European FLOOD risk practices: Towards appropriate and resilient flood risk governance arrangements. This project also provided funding for the author’s participation at the BALTEX Conference.

    Directory of Open Access Journals (Sweden)

    Zbigniew W. Kundzewicz

    2014-01-01

    Full Text Available Flooding is the most destructive natural hazard in the Baltic Sea Basin in general and in Poland in particular. The notion includes floods from rivers and mountain torrents, as well as floods from sea surges in coastal areas, and floods from sewage systems. There have been several large floods in Poland in the last century and in recent decades, with damage exceeding 1% of the Polish GDP. The spatial and temporal characteristics of the flood risk in Poland are reviewed and observations and projections of changes in the flood hazard in the country are discussed. Furthermore, flood defences and flood preparedness systems in Poland are examined, with particular reference to the European Union (EU Floods Directive, which is being implemented in Poland, an EU country. Finally, the public debate on flood risk and flood preparedness is reviewed.

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

    Science.gov (United States)

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

    2017-12-01

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

  2. A geo-environmental assessment of flood dynamics in lower ajoy ...

    African Journals Online (AJOL)

    Flood as a widespread destructive natural disaster is recurring in the river basins of Eastern India. Though large number of flood controlling measures have been taken in the river valleys from the early ages but it is to be noted that spatial dimension of the flood affected area and the magnitude of flood are being increased ...

  3. Effects of polders on the course of floods in the watershed of the Tichá Orlice river

    Directory of Open Access Journals (Sweden)

    Vladimír Pavlík

    2008-01-01

    Full Text Available Polders show an important water-management function in the flood-control protection of watersheds. The course of actual floods in recent decades and effects of the water works on flood flows have proved the suitability of the construction within integrated flood-control measures in particular watersheds of the Czech Republic. To determine the transformation effect of flood-control measures in watersheds mathematical modelling is an important method, which is used not only in the preparation and design of retention areas but also in dealing with the flood protection of towns and villages. Easy verification of other measures in watersheds is also useful. Their implementation can be thus prepared for the future or it is possible to back off the intentions. In our case, a fact is advantageous that the model is ope­ra­ted in the workplace of the Elbe Basin water-management dispatching centre, which is compatible with assessed polders in the partial Elbe watershed, namely in the Tichá Orlice watershed and its partial Třebovka watershed. The polders assessed are situated on the Třebovka stream, which is the lar­gest tributary of the Tichá Orlice river. These dry reservoirs and the increased protective function of the Hvězda pond affect runoff from about 80 km2. Within research activities, possibilities were studied to obtain necessary retention areas in existing small water reservoirs. It became evident that the only rea­lis­tic solution was to increase protective functions of the pond Hvězda. Its present total retention space of 1.4 million m3 can be increased only by 0.35 million m3, however, in combination with the sophisticated lay-out of a new emergency spillway and outlet the whole retention space can be used much more effectively. To obtain other retention areas localities were found out in the whole upper watershed of the Třebovka stream, which fulfilled requirements for placing the adequate capacity of polders. Subsequent

  4. Summary of floods in the United States during 1967

    Science.gov (United States)

    Rostvedt, J.O.

    1972-01-01

    This report describes the most outstanding floods in the United States during 1967. The two most destructive floods occurred in August in east-central Alaska and in September and October in southern Texas. In east-central Alaska, heavy rain on August 8-17 produced record-breaking floods near Fairbanks. Peak discharges on some streams in the area were from two to four times the 50-yea.r flood. Flood damage was estimated to have been $85 million, and six lives were lost. Torrential rains produced by Hurricane Beulah caused record-breaking floods on many streams in a 50,000-square-mile area in southern Texas and northeastern Mexico in September and October. As much as 25.5 inches of rain was measured at ESSA Weather Bureau stations in the period September 19-25. Major flooding occurred in the basins of the Guadalupe, San Antonio, Mission, Arkansas, and Nueces Rivers and in many small coastal basins in Texas ; on the Rio Grande and its floodways ; and in the Rio Alamo and Rio San Juan basins in Mexico. Peak discharges at several sites in Texas were more than three times the magnitude of a 50-year flood. Total damage in Texas due to wind, rain, stream flooding, sheet flow, ponding, and tidal flooding was $167 million. In addition to the two floods mentioned above, 27 others of lesser magnitude are considered important enough to be included in this annual flood summary.

  5. Restoration potential for Danube River Basin, lower Danube and Mura Drava Danube Biosphere Reserve

    Directory of Open Access Journals (Sweden)

    SCHWARZ Ulrich

    2013-12-01

    Full Text Available Originally main Danube basin floodplains would cover an area of 26,500 km², which is equal to about 3.3% of the total catchment size. In recent history, 80% have been cut off by dikes and dams for flood control, hydropower generation, to improve navigability or simply to meliorate land for agricultural purposes. River regulation, rectification and floodplain loss changed the hydromorphological conditions for many major rivers and cause the loss of large water retention areas, the acceleration and unfavourable superimposition of flood waves, the local increase of flood peaks and the loss of functional wetlands and their ecological services. The aim of the investigations commissioned by World Wide Fund (since 2009, three studies with increasing spatial resolution were carried out, for the whole Danube basin and for the lower Danube, Mura and Drava rivers was the assessment and prioritisation of potential restoration areas to support national and international activities in respect to nature conservation, the ecological status improvement under Water Framework Directive (WFD and flood mitigation. Aside of the review of existing and planned major restoration projects, new areas are proposed based on continuously available data sets including land use, spatial configuration, hydromorphological intactness, overlapping protected areas and different floodplain types.

  6. Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

    International Nuclear Information System (INIS)

    Coelho-Souza, Sergio A.; Guimaraes, Jean R.D.; Miranda, Marcio R.; Poirier, Hugo; Mauro, Jane B.N.; Lucotte, Marc; Mergler, Donna

    2011-01-01

    Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, δ 13 C, δ 15 N and bacterial heterotrophic production as 3 H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me 203 Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me 203 Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and δ 13 C. The discriminant analysis showed a significant difference in periphyton δ 15 N, δ 13 C and THg between seasons, where the rainy season presented higher δ 15 N and the wet period lighter δ 13 C, lower THg values and higher Me 203 Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: → During rainy season mercury (Hg 2+ ) is carried out from terrestrial to aquatic systems by runoff. → Macrophyte roots accumulates Hg 2+ from suspended particulate matter (SPM). → Hg methylation increases during the wet season. → Flooded forest is a source of labile organic carbon and bioavailable Hg. → Macrophytes decompose during the dry season and made up terrestrial soil.

  7. Grain size, morphometry and mineralogy of airborne input in the Canary basin: evidence of iron particle retention in the mixed layer

    Directory of Open Access Journals (Sweden)

    Alfredo Jaramillo-Vélez

    2016-09-01

    Full Text Available Aeolian dust plays an important role in climate and ocean processes. Particularly, Saharan dust deposition is of importance in the Canary Current due to its content of iron minerals, which are fertilizers of the ocean. In this work, dust particles are characterized mainly by granulometry, morphometry and mineralogy, using image processing and scanning northern Mauritania and the Western Sahara. The concentration of terrigenous material was measured in three environments: the atmosphere (300 m above sea level, the mixed layer at 10 m depth, and 150 m depth. Samples were collected before and during the dust events, thus allowing the effect of Saharan dust inputs in the water column to be assessed. The dominant grain size was coarse silt. Dominant minerals were iron oxy-hydroxides, silicates and Ca-Mg carbonates. A relative increase of iron mineral particles (hematite and goethite was detected in the mixed layer, reflecting a higher permanence of iron in the water column despite the greater relative density of these minerals in comparison with the other minerals. This higher iron particle permanence does not appear to be explained by physical processes. The retention of this metal by colloids or microorganisms is suggested to explain its long residence time in the mixed layer.

  8. Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

    Energy Technology Data Exchange (ETDEWEB)

    Coelho-Souza, Sergio A., E-mail: sacs@biof.ufrj.br [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Guimaraes, Jean R.D.; Miranda, Marcio R. [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Poirier, Hugo [Chaire de Reserche en Environment, Universite du Quebec a Montreal (UQaM), CP 8888, Montreal, H3C 3P8 (Canada); Mauro, Jane B.N. [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Lucotte, Marc [Chaire de Reserche en Environment, Universite du Quebec a Montreal (UQaM), CP 8888, Montreal, H3C 3P8 (Canada); Mergler, Donna [CINBIOSE, UQaM, CP 8888, succ. Centre-ville, Montreal, H3C 3P8 (Canada)

    2011-06-15

    Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, {delta}{sup 13}C, {delta}{sup 15}N and bacterial heterotrophic production as {sup 3}H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me{sup 203}Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me{sup 203}Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and {delta}{sup 13}C. The discriminant analysis showed a significant difference in periphyton {delta}{sup 15}N, {delta}{sup 13}C and THg between seasons, where the rainy season presented higher {delta}{sup 15}N and the wet period lighter {delta}{sup 13}C, lower THg values and higher Me{sup 203}Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: {yields} During rainy season mercury (Hg{sup 2+}) is carried out from terrestrial to aquatic systems by runoff. {yields} Macrophyte roots accumulates Hg{sup 2+} from suspended particulate matter (SPM). {yields} Hg methylation increases during the wet season. {yields} Flooded forest is a source of labile organic carbon and bioavailable Hg. {yields} Macrophytes

  9. Increasing resilience through participative flood risk map design

    Science.gov (United States)

    Fuchs, Sven; Spira, Yvonne; Stickler, Therese

    2013-04-01

    In recent years, an increasing number of flood hazards has shown to the European Commission and the Member States of the European Union the importance of flood risk management strategies in order to reduce losses and to protect the environment and the citizens. Exposure to floods as well as flood vulnerability might increase across Europe due to the ongoing economic development in many EU countries. Thus even without taking climate change into account an increase of flood disasters in Europe might be foreseeable. These circumstances have produced a reaction in the European Commission, and a Directive on the Assessment and Management of Flood Risks was issued as one of the three components of the European Action Programme on Flood Risk Management. Floods have the potential to jeopardise economic development, above all due to an increase of human activities in floodplains and the reduction of natural water retention by land use activities. As a result, an increase in the likelihood and adverse impacts of flood events is expected. Therefore, concentrated action is needed at the European level to avoid severe impacts on human life and property. In order to have an effective tool available for gathering information, as well as a valuable basis for priority setting and further technical, financial and political decisions regarding flood risk mitigation and management, it is necessary to provide for the establishment of flood risk maps which show the potential adverse consequences associated with different flood scenarios. So far, hazard and risk maps are compiled in terms of a top-down linear approach: planning authorities take the responsibility to create and implement these maps on different national and local scales, and the general public will only be informed about the outcomes (EU Floods Directive, Article 10). For the flood risk management plans, however, an "active involvement of interested parties" is required, which means at least some kind of multilateral

  10. Ecohydraulic-driven real-time control of stormwater basins

    Science.gov (United States)

    Muschalla, Dirk; Vallet, Bertrand; Anctil, François; Lessard, Paul; Pelletier, Geneviève; Vanrolleghem, Peter A.

    2014-04-01

    Control of stormwater basins can be a competitive measure to improve the ecohydraulics of urban rivers by increasing the removal efficiency of particles and agglomerated contaminants like heavy metals and by decreasing hydraulic peak flows. In this paper, we present a simulation study that evaluates the potential of ecohydraulic-driven real-time control of stormwater basins to improve water quality and decrease hydraulic stress in the receiving water body. Nine different static and dynamic control scenarios were analysed based on a detailed hydraulic and quality model of an existing small urban catchment equipped with a stormwater basin at its outlet. Under dynamic control, an outlet valve was manipulated to increase retention time. The removal efficiency for suspended solids could be significantly increased by all control strategies and the hydraulic peaks were reduced by at least 50%. At the same time, overflow of the basin is avoided to prevent flooding. The developed dynamic control strategies proved to be advantageous as they provide significantly higher removal efficiency for suspended solids and a possible flexible adaptation to future demands. The findings of this study have been confirmed by field experiments.

  11. Analysis of change of retention capacity of a small water reservoir

    Science.gov (United States)

    Výleta, R.; Danáčová, M.; Valent, P.

    2017-10-01

    This study is focused on the analysis of the changes of retention capacity of a small water reservoir induced by intensive erosion and sedimentation processes. The water reservoir is situated near the village of Vrbovce in the Western part of Slovakia, and the analysis is carried out for a period 2008-2017. The data used to build a digital elevation model (DEM) of the reservoir’s bed came from a terrain measurement, utilizing an acoustic Doppler current profiler (ADCP) to measure the water depth in the reservoir. The DEM was used to quantify the soil loss from agricultural land situated within the basin of the reservoir. The ability of the water reservoir to transform a design flood with a return period of 100 years is evaluated for both design (2008) and current conditions (2017). The results show that the small water reservoir is a subject to siltation, with sediments comprised of fine soil particles transported from nearby agricultural land. The ability of the water reservoir to transform a 100-year flood has not changed significantly. The reduction of the reservoir’s retention capacity should be systematically and regularly monitored in order to adjust its operational manual and improve its efficiency.

  12. Field note from Pakistan floods: Preventing future flood disasters

    Directory of Open Access Journals (Sweden)

    Marcus Oxley

    2011-04-01

    Full Text Available Unusually heavy monsoon rains in Northern Pakistan have caused disproportionate levels of extreme flooding and unprecedented flood losses across the entire Indus River basin. Extensive land use changes and environmental degradation in the uplands and lowlands of the river basin together with the construction of a “built environment” out of balance with the functioning, capacities, scale and limits of the local ecosystems have exposed millions of people to an increased risk of extreme #ooding. The catastrophic nature of the August #ooding provides a unique opportunity to fundamentally change Pakistan’s current socio-economic development path by incorporating disaster risk reduction and climate change measures into the post-disaster recovery process to rebuild a safer, more resilient nation. In January 2005 one hundred and sixty-eight nations adopted the Hyogo Framework for Action (HFA2005-2015 to bring about a “substantial reduction in disaster losses” by 2015. Despite this global initiative a series of major disasters, including the recent flooding in Pakistan, all indicate that we are not on track to achieve the substantial reduction of disaster losses. The following fieldnote considers what can be done to accelerate progress towards implementation of the Hyogo Framework, drawing on insights and lessons learnt from the August flooding to understand how Pakistan and neighbouring countries can prevent a repeat of such catastrophic disasters in future years.

  13. Evolution of flood management policies of Pakistan and causes of flooding in year 2010

    Directory of Open Access Journals (Sweden)

    Muhammad Arslan

    2016-01-01

    Full Text Available The problem of floods in Pakistan dates back to the year of independence, 1947, when first massive flood inflicted havoc in upper Pakistan. We have divided flood management policy of the region into three time periods; British colonial rule that managed surface water through construction of canals; pre-Indus basin development that achieved a breakthrough in the form of Indus water treaty; and it was during post-Indus basin development phase, in 1973, that federal flood commission and proper flood management policies were devised. However, poor implementation has made these policies ineffective in terms of risk assessment and hazard management. As a case study we discussed the flood of 2010. It was a flash flood in north but inefficient and docile management plans turned it in to a riverine flood as the rainwater receded along the lengths of River Indus, in southern areas. Despite all the obstacles, these huge rainwaters can become a source of much needed energy (electricity if adequate measures are taken. We conclude that the policies regarding flood management within the country must be revisited, and communication gaps between Pakistani and Indian water commissions must be plugged to avoid such future disasters.

  14. Flood loss assessment in Can Tho City, Vietnam

    Science.gov (United States)

    Do, T. C.; Kreibich, H.

    2012-04-01

    Floods are recurring events in the Lower Mekong Basin resulting in loss of life and property, causing damage to agriculture and rural infrastructure, and disrupting social and economic activities. Flood management and mitigation has become a priority issue at the national and regional levels. Besides, it is expected that large areas of the Mekong delta, the Red River delta and the central coast will be flooded by sea-level rise due to climate change. Can Tho City is ranked under the five most flood-tide-influenced cities of Vietnam. It is the biggest city in the Mekong delta and it is located near the Hau river. Like other region of the Mekong delta, Can Tho suffers due to floods from upstream and flood tides from the sea. In the flood season large rural areas of the city are flooded, particularly during tidal days. Flood risk management policy includes preparative measures for living with floods and to minimise the damage caused by floods as well as to take advantage of floods for sustainable development. An intensive literature review, including administrative reports as well as expert interviews have been undertaken to gain more insight into flood characteristics, their consequences and risk mitigation. Therefore, flood damaging processes and trends have been reviewed for Can Tho City and the Mekong Basin in Vietnam. Additionally, suitable flood damage estimation methodologies have been collected as important input for flood risk analyses. On this basis it has been investigated which flood risk mitigation and management strategies promise to be effective in Can Tho City, Vietnam.

  15. Large-scale assessment of flood risk and the effects of mitigation measures along the Elbe River

    NARCIS (Netherlands)

    de Kok, Jean-Luc; Grossmann, M.

    2010-01-01

    The downstream effects of flood risk mitigation measures and the necessity to develop flood risk management strategies that are effective on a basin scale call for a flood risk assessment methodology that can be applied at the scale of a large river. We present an example of a rapid flood risk

  16. Flood forecasting and warning systems in Pakistan

    International Nuclear Information System (INIS)

    Ali Awan, Shaukat

    2004-01-01

    Meteorologically, there are two situations which may cause three types of floods in Indus Basin in Pakistan: i) Meteorological Situation for Category-I Floods when the seasonal low is a semi permanent weather system situated over south eastern Balochistan, south western Punjab, adjoining parts of Sindh get intensified and causes the moisture from the Arabian Sea to be brought up to upper catchments of Chenab and Jhelum rivers. (ii) Meteorological Situation for Category-11 and Category-111 Floods, which is linked with monsoon low/depression. Such monsoon systems originate in Bay of Bengal region and then move across India in general west/north westerly direction arrive over Rajasthan or any of adjoining states of India. Flood management in Pakistan is multi-functional process involving a number of different organizations. The first step in the process is issuance of flood forecast/warning, which is performed by Pakistan Meteorological Department (PMD) utilizing satellite cloud pictures and quantitative precipitation measurement radar data, in addition to the conventional weather forecasting facilities. For quantitative flood forecasting, hydrological data is obtained through the Provincial Irrigation Department and WAPDA. Furthermore, improved rainfall/runoff and flood routing models have been developed to provide more reliable and explicit flood information to a flood prone population.(Author)

  17. Flood Response System—A Case Study

    Directory of Open Access Journals (Sweden)

    Yogesh Kumar Singh

    2017-06-01

    Full Text Available Flood Response System (FRS is a network-enabled solution developed using open-source software. The system has query based flood damage assessment modules with outputs in the form of spatial maps and statistical databases. FRS effectively facilitates the management of post-disaster activities caused due to flood, like displaying spatial maps of area affected, inundated roads, etc., and maintains a steady flow of information at all levels with different access rights depending upon the criticality of the information. It is designed to facilitate users in managing information related to flooding during critical flood seasons and analyzing the extent of damage. The inputs to FRS are provided using two components: (1 a semi-automated application developed indigenously, to delineate inundated areas for Near-Real Time Flood Monitoring using Active Microwave Remote Sensing data and (2 a two-dimensional (2D hydrodynamic river model generated outputs for water depth and velocity in flooded areas for an embankment breach scenario. The 2D Hydrodynamic model, CCHE2D (Center for Computational Hydroscience and Engineering Two-Dimensional model, was used to simulate an area of 600 km2 in the flood-prone zone of the Brahmaputra basin. The resultant inundated area from the model was found to be 85% accurate when validated with post-flood optical satellite data.

  18. The effect of the conditions of a landscape on its retention capacity

    Science.gov (United States)

    Vrána, K.; Dostál, T.; Koudelka, P.; David, V.; Uuléřová, K.

    2010-06-01

    Questions related to the occurrence, frequency, intensity, duration, characteristics and causes of floods have been discussed more in recent years. Two basic approaches to flood control often conflict. The first is based on the assumption of the considerable effect of a landscape's retention capacity, which can in fact prevent surface runoff generation and flood formation and can significantly transform flood wave. The second approach asserts that the retention capacity of a landscape is nearly negligible and that the only reliable flood protection can be provided by extending the technical structures of flood control measures mainly and directly on water courses. Two different approaches were applied to assess the effect of landscape conditions and revitalization measures on surface runoff and flood formation within a catchment and floodplain. The conclusion shows that the effect of landscape revitalization is very important, but mainly for low return periods of flood events, while for extreme events, the effect on landscapes and floodplains becomes less important and even negligible.

  19. Storm Drain Effects on Urban Flooding

    Science.gov (United States)

    2012-08-01

    the GSSHA outflow hydrograph to the USGS observed discharge record at the basin outlet. Saturated hydraulic conductivity (Ksat,) was varied between...hours, more than doubling the flood peak of the Dead Run outlet hydrograph compared to Hurricane Isabel. Although the drainage of the basin was...was the availability of a quality dataset including: rainfall records, stream flow records, digital elevation model ( DEM ), land-use coverage, stream

  20. Regional Flood Frequency Analysis of Catchments in Upper Benue ...

    African Journals Online (AJOL)

    Regional flood frequency analysis was conducted for catchments within Upper Benue river basin in Nigeria using the Index flood (IF) procedure utilizing discharge data collected from six gauging stations located within the region tested to be hydrologically homogeneous. The annual maximum discharges of the gauging ...

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

    Indian Academy of Sciences (India)

    2016-08-26

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

  2. Effect of Urban Green Spaces and Flooded Area Type on Flooding Probability

    Directory of Open Access Journals (Sweden)

    Hyomin Kim

    2016-01-01

    Full Text Available Countermeasures to urban flooding should consider long-term perspectives, because climate change impacts are unpredictable and complex. Urban green spaces have emerged as a potential option to reduce urban flood risks, and their effectiveness has been highlighted in notable urban water management studies. In this study, flooded areas in Seoul, Korea, were divided into four flooded area types by cluster analysis based on topographic and physical characteristics and verified using discriminant analysis. After division by flooded area type, logistic regression analysis was performed to determine how the flooding probability changes with variations in green space area. Type 1 included regions where flooding occurred in a drainage basin that had a flood risk management infrastructure (FRMI. In Type 2, the slope was steep; the TWI (Topographic Wetness Index was relatively low; and soil drainage was favorable. Type 3 represented the gentlest sloping areas, and these were associated with the highest TWI values. In addition, these areas had the worst soil drainage. Type 4 had moderate slopes, imperfect soil drainage and lower than average TWI values. We found that green spaces exerted a considerable influence on urban flooding probabilities in Seoul, and flooding probabilities could be reduced by over 50% depending on the green space area and the locations where green spaces were introduced. Increasing the area of green spaces was the most effective method of decreasing flooding probability in Type 3 areas. In Type 2 areas, the maximum hourly precipitation affected the flooding probability significantly, and the flooding probability in these areas was high despite the extensive green space area. These findings can contribute towards establishing guidelines for urban spatial planning to respond to urban flooding.

  3. Flood risk control of dams and dykes in middle reach of Huaihe River

    Directory of Open Access Journals (Sweden)

    Zhen-kun MA

    2014-01-01

    Full Text Available Three stochastic mathematical models for calculation of the reservoir flood regulation process, river course flood release, and flood risk rate under flood control were established based on the theory of stochastic differential equations and features of flood control systems in the middle reach of the Huaihe River from Xixian to the Bengbu floodgate, comprehensively considering uncertain factors of hydrology, hydraulics, and engineering control. They were used to calculate the flood risk rate with flood regulation of five key reservoirs, including the Meishan, Xianghongdian, Nianyushan, Mozitan, and Foziling reservoirs in the middle reach of the Huaihe River under different flood frequencies, the flood risk rate with river course flood release under design and check floods for the trunk of the Huaihe River in conjunction with relevant flood storage areas, and the flood risk rate with operation of the Linhuaigang Project under design and check floods. The calculated results show that (1 the five reservoirs can withstand design floods, but the Xianghongdian and Foziling reservoirs will suffer overtopping accidents under check floods; (2 considering the service of flood storage areas under the design flood conditions of the Huaihe River, the mean flood risk rate with flood regulation of dykes and dams from Xixian to the Bengbu floodgate is about 0.2, and the trunk of the Huaihe River can generally withstand design floods; and (3 under a check flood with the flood return period of 1 000 years, the risk rate of overtopping accidents of the Linhuaigang Project is not larger than 0.15, indicating that it has a high flood regulation capacity. Through regulation and application of the flood control system of the Linhuigang Project, the Huaihe River Basin can withstand large floods, and the safety of the protected area can be ensured.

  4. A statistical approach to evaluate flood risk at the regional level: an application to Italy

    Science.gov (United States)

    Rossi, Mauro; Marchesini, Ivan; Salvati, Paola; Donnini, Marco; Guzzetti, Fausto; Sterlacchini, Simone; Zazzeri, Marco; Bonazzi, Alessandro; Carlesi, Andrea

    2016-04-01

    Floods are frequent and widespread in Italy, causing every year multiple fatalities and extensive damages to public and private structures. A pre-requisite for the development of mitigation schemes, including financial instruments such as insurance, is the ability to quantify their costs starting from the estimation of the underlying flood hazard. However, comprehensive and coherent information on flood prone areas, and estimates on the frequency and intensity of flood events, are not often available at scales appropriate for risk pooling and diversification. In Italy, River Basins Hydrogeological Plans (PAI), prepared by basin administrations, are the basic descriptive, regulatory, technical and operational tools for environmental planning in flood prone areas. Nevertheless, such plans do not cover the entire Italian territory, having significant gaps along the minor hydrographic network and in ungauged basins. Several process-based modelling approaches have been used by different basin administrations for the flood hazard assessment, resulting in an inhomogeneous hazard zonation of the territory. As a result, flood hazard assessments expected and damage estimations across the different Italian basin administrations are not always coherent. To overcome these limitations, we propose a simplified multivariate statistical approach for the regional flood hazard zonation coupled with a flood impact model. This modelling approach has been applied in different Italian basin administrations, allowing a preliminary but coherent and comparable estimation of the flood hazard and the relative impact. Model performances are evaluated comparing the predicted flood prone areas with the corresponding PAI zonation. The proposed approach will provide standardized information (following the EU Floods Directive specifications) on flood risk at a regional level which can in turn be more readily applied to assess flood economic impacts. Furthermore, in the assumption of an appropriate

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

    DEFF Research Database (Denmark)

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

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

  6. A Geo-Environmental Assessment of Flood Dynamics in Lower Ajoy ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    A Geo-Environmental Assessment of Flood Dynamics in Lower Ajoy River Inducing Sand. Splay Problem in Eastern India. Sutapa Mukhopadhyay. Abstract: Flood as a widespread destructive natural disaster is recurring in the river basins of Eastern India. Though large number of flood controlling measures have been taken ...

  7. Flood Hazard Mapping Assessment for Lebanon

    Science.gov (United States)

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

    2014-05-01

    Of all natural disasters, floods affect the greatest number of people worldwide and have the greatest potential to cause damage. In fact, floods are responsible for over one third of people affected by natural disasters; almost 190 million people in more than 90 countries are exposed to catastrophic floods every year. Nowadays, with the emerging global warming phenomenon, this number is expected to increase, therefore, flood prediction and prevention has become a necessity in many places around the globe to decrease damages caused by flooding. Available evidence hints at an increasing frequency of flooding disasters being witnessed in the last 25 years in Lebanon. The consequences of such events are tragic including annual financial losses of around 15 million dollars. In this work, a hydrologic-hydraulic modeling framework for flood hazard mapping over Lebanon covering 19 watershed was introduced. Several empirical, statistical and stochastic methods to calculate the flood magnitude and its related return periods, where rainfall and river gauge data are neither continuous nor available on a long term basis with an absence of proper river sections that under estimate flows during flood events. TRMM weather satellite information, automated drainage networks, curve numbers and other geometrical characteristics for each basin was prepared using WMS-software and then exported into HMS files to implement the hydrologic modeling (rainfall-runoff) for single designed storm of uniformly distributed depth along each basin. The obtained flow hydrographs were implemented in the hydraulic model (HEC-RAS) where relative water surface profiles are calculated and flood plains are delineated. The model was calibrated using the last flood event of January 2013, field investigation, and high resolution satellite images. Flow results proved to have an accuracy ranging between 83-87% when compared to the computed statistical and stochastic methods. Results included the generation of

  8. 75 FR 67317 - Proposed Flood Elevation Determinations

    Science.gov (United States)

    2010-11-02

    ... above State City/town/county Source of flooding Location ** ground [caret] Elevation in meters (MSL) Existing Modified Unincorporated Areas of Butte-Silver Bow County, Montana Montana Unincorporated Areas of Basin Creek Approximately 1,000 feet upstream of I-90 +5468 +5469 Butte-Silver Bow County. Approximately...

  9. 76 FR 8978 - Proposed Flood Elevation Determinations

    Science.gov (United States)

    2011-02-16

    .../town/county Source of flooding Location ** ground [caret] Elevation in meters (MSL) Existing Modified Unincorporated Areas of Yolo County, California California Unincorporated Areas of Cache Creek Settling Basin At........ Entire None +901 Town of shoreline Wolcottvill e, Unincorpora ted Areas of LaGrange County. * National...

  10. Validating quantitative precipitation forecast for the Flood ...

    Indian Academy of Sciences (India)

    In order to issue an accurate warning for flood, a better or appropriate quantitative forecasting of precipitationis required. In view of this, the present study intends to validate the quantitative precipitationforecast (QPF) issued during southwest monsoon season for six river catchments (basin) under theflood meteorological ...

  11. Characterization of Soil-Water Retention with Coarse Fragments in ...

    African Journals Online (AJOL)

    The presence of coarse fragments can have profound impact on soil moisture retention characteristics. The study was conducted to assess the effects of coarse fragments on the moisture retention characteristics of 16 soil series, developed over five different parent materials in the Densu basin. Soil profiles were excavated ...

  12. Morphometric and landuse analysis: implications on flood hazards ...

    African Journals Online (AJOL)

    This study assessed the morphometric, landuse and lithological attributes of five basins (Iwaraja, Ilesa, Olupona, Osogbo I and Osogbo II) with particular reference to flood hazards in Ilesa and Osogbo metropolis, Osun State Nigeria. Ilesa town is situated within Iwaraja and Ilesa basins while Osogbo metropolis spread ...

  13. Extreme flood events in the Bolivian Amazon wetlands

    Directory of Open Access Journals (Sweden)

    A. Ovando

    2016-03-01

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

  14. Radionuclide migration in river basins with discharged waste waters from uranium industry at increased water levels, using Ploucnice river as an example

    International Nuclear Information System (INIS)

    Hanslik, E.; Mansfeld, A.; Simonek, P.; Moucha, V.

    1993-01-01

    Field experiments gave evidence that in the non-steady-state regime, radioactive substances and (in this case) barium, or undissolved barium sulfate, brought to the flood area with the through-flow wave and subsequently forming a sediment there are potential sources of secondary contamination of the river basin. The radioactive substance flow balance for the investigated segment of the Ploucnice river showed that the Ra-226 retention was 81% and 74% in 1990 and 1991, respectively, that of the undissolved uranium species was 78% in 1990, and that of the undissolved barium was 87% and 72% in the two years, respectively. (Z.S.) 1 tab., 2 figs., 4 refs

  15. Flood Hazard Assessment for the Savannah River Site

    International Nuclear Information System (INIS)

    Chen, K.F.

    2000-01-01

    A method was developed to determine the probabilistic flood elevation curves for certain Savannah River Site (SRS) facilities. This paper presents the method used to determine the probabilistic flood elevation curve for F-Area due to runoff from the Upper Three Runs basin. Department of Energy (DOE) Order 420.1, Facility Safety, outlines the requirements for Natural Phenomena Hazard (NPH) mitigation for new and existing DOE facilities. The NPH considered in this paper is flooding. The facility-specific probabilistic flood hazard curve defines as a function of water elevation the annual probability of occurrence or the return period in years. Based on facility-specific probabilistic flood hazard curves and the nature of facility operations (e.g., involving hazardous or radioactive materials), facility managers can design permanent or temporary devices to prevent the propagation of flood on site, and develop emergency preparedness plans to mitigate the consequences of floods. A method was developed to determine the probabilistic flood hazard curves for SRS facilities. The flood hazard curves for the SRS F-Area due to flooding in the Upper Three Runs basin are presented in this paper

  16. Risk-trading in flood management: An economic model.

    Science.gov (United States)

    Chang, Chiung Ting

    2017-09-15

    Although flood management is no longer exclusively a topic of engineering, flood mitigation continues to be associated with hard engineering options. Flood adaptation or the capacity to adapt to flood risk, as well as a demand for internalizing externalities caused by flood risk between regions, complicate flood management activities. Even though integrated river basin management has long been recommended to resolve the above issues, it has proven difficult to apply widely, and sometimes even to bring into existence. This article explores how internalization of externalities as well as the realization of integrated river basin management can be encouraged via the use of a market-based approach, namely a flood risk trading program. In addition to maintaining efficiency of optimal resource allocation, a flood risk trading program may also provide a more equitable distribution of benefits by facilitating decentralization. This article employs a graphical analysis to show how flood risk trading can be implemented to encourage mitigation measures that increase infiltration and storage capacity. A theoretical model is presented to demonstrate the economic conditions necessary for flood risk trading. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Geomorphic Flood Area (GFA): a DEM-based tool for flood susceptibility mapping at large scales

    Science.gov (United States)

    Manfreda, S.; Samela, C.; Albano, R.; Sole, A.

    2017-12-01

    Flood hazard and risk mapping over large areas is a critical issue. Recently, many researchers are trying to achieve a global scale mapping encountering several difficulties, above all the lack of data and implementation costs. In data scarce environments, a preliminary and cost-effective floodplain delineation can be performed using geomorphic methods (e.g., Manfreda et al., 2014). We carried out several years of research on this topic, proposing a morphologic descriptor named Geomorphic Flood Index (GFI) (Samela et al., 2017) and developing a Digital Elevation Model (DEM)-based procedure able to identify flood susceptible areas. The procedure exhibited high accuracy in several test sites in Europe, United States and Africa (Manfreda et al., 2015; Samela et al., 2016, 2017) and has been recently implemented in a QGIS plugin named Geomorphic Flood Area (GFA) - tool. The tool allows to automatically compute the GFI, and turn it into a linear binary classifier capable of detecting flood-prone areas. To train this classifier, an inundation map derived using hydraulic models for a small portion of the basin is required (the minimum is 2% of the river basin's area). In this way, the GFA-tool allows to extend the classification of the flood-prone areas across the entire basin. We are also defining a simplified procedure for the estimation of the river depth, which may be helpful for large-scale analyses to approximatively evaluate the expected flood damages in the surrounding areas. ReferencesManfreda, S., Nardi, F., Samela, C., Grimaldi, S., Taramasso, A. C., Roth, G., & Sole, A. (2014). Investigation on the use of geomorphic approaches for the delineation of flood prone areas. J. Hydrol., 517, 863-876. Manfreda, S., Samela, C., Gioia, A., Consoli, G., Iacobellis, V., Giuzio, L., & Sole, A. (2016). Flood-prone areas assessment using linear binary classifiers based on flood maps obtained from 1D and 2D hydraulic models. Nat. Hazards, Vol. 79 (2), pp 735-754. Samela, C

  18. Integrated Hydrographical Basin Management. Study Case - Crasna River Basin

    Science.gov (United States)

    Visescu, Mircea; Beilicci, Erika; Beilicci, Robert

    2017-10-01

    Hydrographical basins are important from hydrological, economic and ecological points of view. They receive and channel the runoff from rainfall and snowmelt which, when adequate managed, can provide fresh water necessary for water supply, irrigation, food industry, animal husbandry, hydrotechnical arrangements and recreation. Hydrographical basin planning and management follows the efficient use of available water resources in order to satisfy environmental, economic and social necessities and constraints. This can be facilitated by a decision support system that links hydrological, meteorological, engineering, water quality, agriculture, environmental, and other information in an integrated framework. In the last few decades different modelling tools for resolving problems regarding water quantity and quality were developed, respectively water resources management. Watershed models have been developed to the understanding of water cycle and pollution dynamics, and used to evaluate the impacts of hydrotechnical arrangements and land use management options on water quantity, quality, mitigation measures and possible global changes. Models have been used for planning monitoring network and to develop plans for intervention in case of hydrological disasters: floods, flash floods, drought and pollution. MIKE HYDRO Basin is a multi-purpose, map-centric decision support tool for integrated hydrographical basin analysis, planning and management. MIKE HYDRO Basin is designed for analyzing water sharing issues at international, national and local hydrographical basin level. MIKE HYDRO Basin uses a simplified mathematical representation of the hydrographical basin including the configuration of river and reservoir systems, catchment hydrology and existing and potential water user schemes with their various demands including a rigorous irrigation scheme module. This paper analyzes the importance and principles of integrated hydrographical basin management and develop a case

  19. Texas floods of 1940

    Science.gov (United States)

    Breeding, Seth D.

    1948-01-01

    Floods occurred in Texas during, June, July, and November 1940 that exceeded known stages on many small streams and at a few places on the larger streams. Stages at several stream-gaging stations exceeded the maximum known at those places since the collection of daily records began. A storm, haying its axis generally on a north-south line from Cameron to Victoria and extending across the Brazos, Colorado, Lavaca, and Guadalupe River Basins, caused heavy rainfall over a large part of south-central Texas. The maximum recorded rain of 22.7 inches for the 2-day period June 29-30 occurred at Engle. Of this amount, 17.5 inches fell in the 12-hour period between 8 p.m. June 29, and 8 a.m. June 30. Light rains fell at a number of places on June 28, and additional light rains fell at many places within the area from July 1 to 4. During the period June 28 to July 4 more than 20 inches of rain fell over an area of 300 square miles, more than 15 inches over 1,920 square miles, and more than 10 inches over 5,100 square miles. The average annual rainfall for the area experiencing the heaviest rainfall during this storm is about 35 inches. Farming is largely confined to the fertile flood plains in much of the area subjected to the record-breaking floods in June and July. Therefore these floods, coming at the height of the growing season, caused severe losses to crops. Much damage was done also to highways and railways. The city of Hallettsville suffered the greatest damage of any urban area. The Lavaca River at that place reached a stage 8 feet higher than ever known before, drowned several people, destroyed many homes, and submerged almost the entire business district. The maximum discharge there was 93,100 second-feet from a drainage area of 101 square miles. Dry Creek near Smithville produced a maximum discharge of 1,879 second-feet from an area of 1.48 square miles and a runoff of 11.3 inches in a 2-day period from a rainfall of 19.5 inches. The area in the Colorado River

  20. Assessment of vulnerability to extreme flash floods in design storms.

    Science.gov (United States)

    Kim, Eung Seok; Choi, Hyun Il

    2011-07-01

    There has been an increase in the occurrence of sudden local flooding of great volume and short duration caused by heavy or excessive rainfall intensity over a small area, which presents the greatest potential danger threat to the natural environment, human life, public health and property, etc. Such flash floods have rapid runoff and debris flow that rises quickly with little or no advance warning to prevent flood damage. This study develops a flash flood index through the average of the same scale relative severity factors quantifying characteristics of hydrographs generated from a rainfall-runoff model for the long-term observed rainfall data in a small ungauged study basin, and presents regression equations between rainfall characteristics and the flash flood index. The aim of this study is to develop flash flood index-duration-frequency relation curves by combining the rainfall intensity-duration-frequency relation and the flash flood index from probability rainfall data in order to evaluate vulnerability to extreme flash floods in design storms. This study is an initial effort to quantify the flash flood severity of design storms for both existing and planned flood control facilities to cope with residual flood risks due to extreme flash floods that have ocurred frequently in recent years.

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

    Science.gov (United States)

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

    2017-04-01

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

  2. Flood risk awareness during the 2011 floods in the central United States: showcasing the importance of hydrologic data and interagency collaboration

    Science.gov (United States)

    Holmes, Robert R.; Schwein, Noreen O.; Shadie, Charles E.

    2012-01-01

    Floods have long had a major impact on society and the environment, evidenced by the more than 1,500 federal disaster declarations since 1952 that were associated with flooding. Calendar year 2011 was an epic year for floods in the United States, from the flooding on the Red River of the North in late spring to the Ohio, Mississippi, and Missouri River basin floods in the spring and summer to the flooding caused by Hurricane Irene along the eastern seaboard in August. As a society, we continually seek to reduce flood impacts, with these efforts loosely grouped into two categories: mitigation and risk awareness. Mitigation involves such activities as flood assessment, flood control implementation, and regulatory activities such as storm water and floodplain ordinances. Risk awareness ranges from issuance of flood forecasts and warnings to education of lay audiences about the uncertainties inherent in assessing flood probability and risk. This paper concentrates on the issue of flood risk awareness, specifically the importance of hydrologic data and good interagency communication in providing accurate and timely flood forecasts to maximize risk awareness. The 2011 floods in the central United States provide a case study of the importance of hydrologic data and the value of proper, timely, and organized communication and collaboration around the collection and dissemination of that hydrologic data in enhancing the effectiveness of flood forecasting and flood risk awareness.

  3. Managing retention.

    Science.gov (United States)

    Carter, Tony

    2007-01-01

    To build this process it is necessary to consult customers for preferences, build familiarity and knowledge to build a relationship and conduct business in a customized fashion. The process takes every opportunity to build customer satisfaction with each customer contact. It is an important process to have, since customers today are more demanding, sophisticated, educated and comfortable speaking to the company as an equal (Belk, 2003). Customers have more customized expectations so they want to be reached as individuals (Raymond and Tanner, 1994). Also, a disproportionate search for new business is costly. The cost to cultivate new customers is more than maintaining existing customers (Cathcart, 1990). Other reasons that customer retention is necessary is because many unhappy customers will never buy again from a company that dissatisfied them and they will communicate their displeasure to other people. These dissatisfied customers may not even convey their displeasure but without saying anything just stop doing business with that company, which may keep them unaware for some time that there is any problem (Cathcart, 1990).

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

    Directory of Open Access Journals (Sweden)

    M. A. Gusyev

    2015-06-01

    Full Text Available 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. THE STRUCTURE OF THE WATER CONSTRUCTIONS IN THE SEBES HYDROGRAPHIC BASIN AND THE STORAGE RESERVOIRS. EFFECT ON THE AVERAGE DISCHARGE

    Directory of Open Access Journals (Sweden)

    Stef Iulian Ioan

    2013-05-01

    Full Text Available In the upper basin of the Sebes Valley, the oldest storage lakes have been temporary artificial lakes, called haituri in Romanian. They were created within the forest exploitation areas. Inside the dams of those retention lakes, which dams are made of a wooden skeleton, filled with soil and stones, there have been weirs for the quick discharge of the water, having the purpose of creating some flood trends, capable of carrying over the logs, downstream the lake. At present, some of those temporary artificial lakes are used as trout farms, while others are damaged, or operate as basins for the sedimentation of the alluvial deposits. The difference of level between the springs of the Sebes and the Mures Rivers generates a convertible hydroelectric potential, having an average power exceeding 60,000 kW" />

  6. A dimension reduction method for flood compensation operation of multi-reservoir system

    Science.gov (United States)

    Jia, B.; Wu, S.; Fan, Z.

    2017-12-01

    Multiple reservoirs cooperation compensation operations coping with uncontrolled flood play vital role in real-time flood mitigation. This paper come up with a reservoir flood compensation operation index (ResFCOI), which formed by elements of flood control storage, flood inflow volume, flood transmission time and cooperation operations period, then establish a flood cooperation compensation operations model of multi-reservoir system, according to the ResFCOI to determine a computational order of each reservoir, and lastly the differential evolution algorithm is implemented for computing single reservoir flood compensation optimization in turn, so that a dimension reduction method is formed to reduce computational complexity. Shiguan River Basin with two large reservoirs and an extensive uncontrolled flood area, is used as a case study, results show that (a) reservoirs' flood discharges and the uncontrolled flood are superimposed at Jiangjiaji Station, while the formed flood peak flow is as small as possible; (b) cooperation compensation operations slightly increase in usage of flood storage capacity in reservoirs, when comparing to rule-based operations; (c) it takes 50 seconds in average when computing a cooperation compensation operations scheme. The dimension reduction method to guide flood compensation operations of multi-reservoir system, can make each reservoir adjust its flood discharge strategy dynamically according to the uncontrolled flood magnitude and pattern, so as to mitigate the downstream flood disaster.

  7. Integration of Remote Sensing Data In Operational Flood Forecast In Southwest Germany

    Science.gov (United States)

    Bach, H.; Appel, F.; Schulz, W.; Merkel, U.; Ludwig, R.; Mauser, W.

    Methods to accurately assess and forecast flood discharge are mandatory to minimise the impact of hydrological hazards. However, existing rainfall-runoff models rarely accurately consider the spatial characteristics of the watershed, which is essential for a suitable and physics-based description of processes relevant for runoff formation. Spatial information with low temporal variability like elevation, slopes and land use can be mapped or extracted from remote sensing data. However, land surface param- eters of high temporal variability, like soil moisture and snow properties are hardly available and used in operational forecasts. Remote sensing methods can improve flood forecast by providing information on the actual water retention capacities in the watershed and facilitate the regionalisation of hydrological models. To prove and demonstrate this, the project 'InFerno' (Integration of remote sensing data in opera- tional water balance and flood forecast modelling) has been set up, funded by DLR (50EE0053). Within InFerno remote sensing data (optical and microwave) are thor- oughly processed to deliver spatially distributed parameters of snow properties and soil moisture. Especially during the onset of a flood this information is essential to estimate the initial conditions of the model. At the flood forecast centres of 'Baden- Württemberg' and 'Rheinland-Pfalz' (Southwest Germany) the remote sensing based maps on soil moisture and snow properties will be integrated in the continuously op- erated water balance and flood forecast model LARSIM. The concept is to transfer the developed methodology from the Neckar to the Mosel basin. The major challenges lie on the one hand in the implementation of algorithms developed for a multisensoral synergy and the creation of robust, operationally applicable remote sensing products. On the other hand, the operational flood forecast must be adapted to make full use of the new data sources. In the operational phase of the

  8. 13 Morphometric Analysis of Ogunpa and Ogbere Drainage Basins ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    The paper analysed the morphometric parameters of Ogbere and Ogunpa drainage basins located on basement complex rock in ... properties of Ogunpa drainage basin are likely to induce high magnitude flood compared to morphometric properties of Ogbere ..... Bs = VI/HE where Bs = Basin slope, VI = Vertical Interval and.

  9. Commonalities and Differences in Flood-Generating Processes across the US

    Science.gov (United States)

    Li, X.; Troy, T. J.

    2017-12-01

    There is significant damage caused by flood, and the flood risk is increasing in the future, but there is large uncertainty in future decadal projections of flooding. In order to improve these projections, we must first turn to the past to understand the physical mechanisms that lead to flooding in basins across spatial scales and elevation ranges. To do this, we calculated the seasonality of annual maximum flows and other climatic factors to identify the flood-generating process in 2566 basins across the continental US. For most regions, the seasonality of heavy precipitation is not in phase with the seasonality of flooding, pointing to the importance of antecedent soil moisture and snow in determining flooding over much of the US. To determine the characteristic conditions leading to a flood, we classified all floods into those with different rainfall durations and with/without snow presence. Analyzing the influence of elevation, slope and drainage area, we identified patterns: the probability of flooding due to long duration precipitation increases as drainage area increases and snow present during a flood becomes increasingly likely as average basin elevation increases. To better understand the relationship between heavy rainfall and high streamflow, we calculated conditioned probability of occurrence. The southeastern US has a higher probability of occurrence for extreme Q with the same level of extreme precipitation in winter and spring than the northern US. This work is the first to look at how flood mechanisms vary across the continental US with drainage area, climate, and elevation.

  10. Flood hazard assessment for the Savannah River Site

    International Nuclear Information System (INIS)

    Chen, K.F.

    2000-01-01

    A method was developed to determine the probabilistic flood elevation curves for certain Savannah River Site (SRS) facilities. This paper presents the method used to determine the probabilistic flood elevation curve for F-Area due to runoff from the Upper Three Runs basin. Department of Energy (DOE) Order 420.1, Facility Safety, outlines the requirements for Natural Phenomena Hazard (NPH) mitigation for new and existing DOE facilities. The NPH considered in this paper is flooding. The facility-specific probabilistic flood hazard curve defines as a function of water elevation the annual probability of occurrence or the return period in years. Based on facility-specific probabilistic flood hazard curves and the nature of facility operations (e.g., involving hazardous or radioactive materials), facility managers can design permanent or temporary devices to prevent the propagation of flood on site, and develop emergency preparedness plans to mitigate the consequences of floods. The flood hazard curves for the SRS F-Area due to flooding in the Upper Three Runs basin are presented in this paper

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

    Science.gov (United States)

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

    2014-05-01

    . The January 1910's flood is one of these remarkable floods. This event is foremost known for its aftermaths on the Seine basin, where the flood remains the strongest recorded in Paris since 1658. However, its impacts were also widespread to France's Eastern regions (Martin, 2001). To demonstrate the evaluation grid's interest, we propose a deep analysis of the 1910's river flood with the integration of historical documentation. The approach focus on eastern France where the flood remains the highest recorded for several rivers but were often neglected by scientists in favor of Paris's flood. Through a transdisciplinary research based on the evaluation grid method, we will describe the January 1910 flood event and define why it can be considered as a remarkable flood for these regions.

  12. Flooding and Schools

    Science.gov (United States)

    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,…

  13. BDHI: a French national database on historical floods

    Directory of Open Access Journals (Sweden)

    Lang Michel

    2016-01-01

    Full Text Available The paper describes the various features of the BDHI database (objects, functions, content. This document database provides document sheets on historical floods from various sources: technical reports from water authorities, scientific accounts (meteorology, hydrology, hydraulics..., post-disaster reports, newspapers or book extracts... It is complemented by fact sheets on flood events, which provide a summary text on significant past floods: location, date and duration, type of flood, extent, probability, adverse consequences A search engine is provided for information search based on time (specific date or period, on location (district, basin, city or thematic topic (document type, flood type, flood magnitude, flood impact.... We conclude by some future challenges in relation to the next cycle of the Floods Directive (2016-2022, with the inventory of past floods which had significant adverse impacts. What are the flood events that need to be integrated (new ones later than 2011 and/or previous floods that had not yet been selected? How can the process of historical data integration be extended at a local scale, with an adequate process of validation? How to promote the use of BDHI database in relation with the development of the culture of risk?

  14. Developing a national programme of flood risk management measures: Moldova

    Directory of Open Access Journals (Sweden)

    Ramsbottom David

    2016-01-01

    Full Text Available A Technical Assistance project funded by the European Investment Bank has been undertaken to develop a programme of flood risk management measures for Moldova that will address the main shortcomings in the present flood management system, and provide the basis for long-term improvement. Areas of significant flood risk were identified using national hydraulic and flood risk modelling, and flood hazard and flood risk maps were then prepared for these high risk areas. The flood risk was calculated using 12 indicators representing social, economic and environmental impacts of flooding. Indicator values were combined to provide overall estimates of flood risk. Strategic approaches to flood risk management were identified for each river basin using a multi-criteria analysis. Measures were then identified to achieve the strategic approaches. A programme of measures covering a 20-year period was developed together with a more detailed Short-Term Investment Plan covering the first seven years of the programme. Arrangements are now being made to implement the programme. The technical achievements of the project included national hydrological and hydraulic modelling covering 12,000 km of river, the development of 2-dimensional channel and floodplain hydraulic models from a range of topographic and bathymetric data, and an integrated flood risk assessment that takes account of both economic and non-monetary impacts.

  15. Non-stationary regional flood frequency analysis: a new framework based on the index-flood method

    Science.gov (United States)

    Mondal, A.; Kalai, C.

    2016-12-01

    Prediction in ungauged basins is necessary for water resources planning and management, and also for engineering and design. Regional frequency analysis approaches that are used for flood prediction in ungauged basins assume stationarity of flood generation mechanisms, that is, the statistical properties of the processes do not change with time and that the past can act as a guide to the future. The index flood method is one such approach for obtaining flood quantile estimates using regionalization techniques. However, under man-made or natural changes, the stationarity assumption may not be valid. For example, a warmer climate under greenhouse effect can hold more moisture leading to an intensification of the hydrologic cycle. Most existing tools and techniques on regional flood frequency analysis do not account for such changes. In this study, we use a mathematical approach based on a simple transformation within the index flood method framework, to circumvent the stationarity assumption and demonstrate its applicability for time-varying floods. The approach involves i) estimation of at-site parameters using the maximum likelihood approach, ii) transformation of observed non-stationary floods to standardized residuals, iii) computation of regional parameters using the standardized residuals, iv) obtaining flood quantile estimates for the standardized residuals, and v) back-transformation of the quantiles to the original domain to obtain non-stationary flood return levels. Monte Carlo simulation experiments, assuming all sites in the region belong to the Generalized Extreme Value (GEV) distribution, show that the proposed method can capture time-varying behaviour of the flood quantiles quite well and can act as an effective way to address non-stationarity in regional flood frequency analysis. Efforts are underway to illustrate the applicability of this framework on real catchments where flood behaviour show significant change with time.

  16. The complexities of urban flood response : Flood frequency analyses for the Charlotte metropolitan region

    NARCIS (Netherlands)

    Zhou, Zhengzheng; Smith, James A.; Yang, Long; Baeck, Mary Lynn; Chaney, Molly; ten Veldhuis, J.A.E.; Deng, Huiping; Liu, Shuguang

    2017-01-01

    We examine urban flood response through data-driven analyses for a diverse sample of “small” watersheds (basin scale ranging from 7.0 to 111.1 km2) in the Charlotte Metropolitan region. These watersheds have experienced extensive urbanization and suburban development since the 1960s.

  17. Hurricane-driven floods in Mexico City

    Science.gov (United States)

    Naranjo, M.

    2012-04-01

    Over thousands of years, floods have globally been the main cause of natural disasters. Over the last century, the impact of floods has been increased due to several factors as the rise in human population, settlements in risk prone areas, land use and cover changes and, the intensification of the hydrological cycle. Currently, disaster management must be carried out with the support of multidisciplinary teams that combine hydrologic and hydraulic studies with socio-economic assessments. We provide an example from the metropolitan area of Mexico City. Previously located in an endorheic basin, its current location lies over several lakes that were intensively managed since the 17th century. Although regular floods have been a characteristic of the region, it is since the 17th century that major sewage works were built in order to mitigate the impact of floods on the urban area. Nowadays, the basin has four artificial outlets that drain the urban runoff and wastewater though only one outlet is gravity-based whereas the remaining three need pumping to work properly. Hence, a hypothetical failure in the drainage system during a major storm event could trigger a flood-related catastrophe. The occurrence of such catastrophe could be driven by precipitation systems derived from the incidence of hurricanes along the Gulf of Mexico. This work analyzes the failure of the gates in the sewage system that provoked a substantial urban inundation in the northern part of Mexico City.

  18. Flood Hazard Assessment along the Western Regions of Saudi Arabia using GIS-based Morphometry and Remote Sensing Techniques

    KAUST Repository

    Shi, Qianwen

    2014-12-01

    Flash flooding, as a result of excessive rainfall in a short period, is considered as one of the worst environmental hazards in arid regions. Areas located in the western provinces of Saudi Arabia have experienced catastrophic floods. Geomorphologic evaluation of hydrographic basins provides necessary information to define basins with flood hazard potential in arid regions, especially where long-term field observations are scarce and limited. Six large basins (from North to South: Yanbu, Rabigh, Khulais, El-Qunfza, Baish and Jizan) were selected for this study because they have large surface areas and they encompass high capacity dams at their downstream areas. Geographic Information System (GIS) and remote sensing techniques were applied to conduct detailed morphometric analysis of these basins. The six basins were further divided into 203 sub-basins based on their drainage density. The morphometric parameters of the six basins and their associated 203 sub-basins were calculated to estimate the degree of flood hazard by combining normalized values of these parameters. Thus, potential flood hazard maps were produced from the estimated hazard degree. Furthermore, peak runoff discharge of the six basins and sub-basins were estimated using the Snyder Unit Hydrograph and three empirical models (Nouh’s model, Farquharson’s model and Al-Subai’s model) developed for Saudi Arabia. Additionally, recommendations for flood mitigation plans and water management schemes along these basins were further discussed.

  19. The August 2002 flood in Prague

    Science.gov (United States)

    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

  20. Summary of floods in the United States during 1961

    Science.gov (United States)

    Rostvedt, J.O.

    1965-01-01

    This report describes the most outstanding floods in the United States during 1961. The most damaging floods during the year were those caused by snowmelt in March and April in the upper Mississippi River basin and those accompanying Hurricane Carla in September.Hurricane Carla traveled northward along the east edge of Texas and then northeastward through southeastern Oklahoma, northwestern Arkansas, southeastern Missouri, and central Illinois. Heavy rains and floods occurred east of the hurricane's path in Texas and west of its path for the remainder of its journey.Mississippi, Alabama, and Georgia had moderate to severe floods in February and March from a series of large-area rainstorms. Many maximum peak discharges occurred, and streams remained at high stages for periods longer than any known before. Property damage was high and four lives were lost.Extensive flooding took place in May from southeastern Kansas and northeastern Oklahoma through northern Arkansas, southern Missouri, northern Kentucky, and the southern parts of Illinois, Indiana, and Ohio. Maximum discharges occurred at many sites throughout the area.Heavy flooding was experienced on Kootenai River at Bonners Ferry, Idaho, in May and June. These floods were noteworthy for their duration.The most tragic flood of the year was in July in Charleston, W. Va. A small area cloudburst flood caused 22 deaths and damage of more than \\$1 million.Severe flooding occurred in December in the Tombigbee River, Pearl River, and Pascagoula River basins in Mississippi, Louisiana, and Alabama. Much damage resulted, and from two to three thousand persons were evacuated from large flooded areas.In addition to the floods mentioned above, 19 others of lesser magnitude are considered important enough to be included in this annual summary.

  1. Combining Space-Based and In-Situ Measurements to Track Flooding in Thailand

    Science.gov (United States)

    Chien, Steve; Doubleday, Joshua; Mclaren, David; Tran, Daniel; Tanpipat, Veerachai; Chitradon, Royal; Boonya-aaroonnet, Surajate; Thanapakpawin, Porranee; Khunboa, Chatchai; Leelapatra, Watis; hide

    2011-01-01

    We describe efforts to integrate in-situ sensing, space-borne sensing, hydrological modeling, active control of sensing, and automatic data product generation to enhance monitoring and management of flooding. In our approach, broad coverage sensors and missions such as MODIS, TRMM, and weather satellite information and in-situ weather and river gauging information are all inputs to track flooding via river basin and sub-basin hydrological models. While these inputs can provide significant information as to the major flooding, targetable space measurements can provide better spatial resolution measurements of flooding extent. In order to leverage such assets we automatically task observations in response to automated analysis indications of major flooding. These new measurements are automatically processed and assimilated with the other flooding data. We describe our ongoing efforts to deploy this system to track major flooding events in Thailand.

  2. The analysis of may 29 2012 flood phenomena in the lower sector of Slănic drainage basin (case of Cernăteşti locality area

    Directory of Open Access Journals (Sweden)

    Romulus COSTACHE

    2013-02-01

    Full Text Available This paper aims to analyze, especially in terms of space, the phenomenon of flooding for Cernăteşti locality, dated May 29, 2012. In the context of high intensity torrential rains, in a short period of time, in this period occurred flash-floods of high intensity on Slănic river, producing catastrophic floods in Cernăteşti locality. Thus, for a rigorous analysis of spatial occurrence of these hydrological risk phenomena, were used detailed cartographic materials like 1:5000 topographic plans overlapped to analyzed territory. Also, have been analyzed and synoptic conditions directly responsible for floods extent with disastrous effects on socio-economic component.  The results certified that, due to the synergy between torrential rainfall and local morphometry, 60 ha of Slănic water meadow  sector was flooded on Cernăteşti locality segment, when more than 20 buildings and almost 500 m of the local accessiblity infrastucture were damaged

  3. Fuel nozzle tube retention

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  4. Groundwater flood or groundwater-induced flood?

    OpenAIRE

    Robins, N.S.; Finch, J.W.

    2012-01-01

    A number of ‘groundwater flood’ events have been recorded over the Chalk aquifer in southern England since the 1994 occurrence at Chichester, Sussex. Reporting of this event and subsequent groundwater floods indicates that there are two types of groundwater flood event. Type 1 is the true groundwater flood in which the water table elevation rises above the ground elevation, and Type 2 occurs when intense groundwater discharge via bourne springs and highly permeable shallow horizons discharges...

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

    Science.gov (United States)

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

    2008-12-01

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

  6. Spatial coherence of flood-rich and flood-poor periods across Germany

    Science.gov (United States)

    Merz, Bruno; Dung, Nguyen Viet; Apel, Heiko; Gerlitz, Lars; Schröter, Kai; Steirou, Eva; Vorogushyn, Sergiy

    2018-04-01

    Despite its societal relevance, the question whether fluctuations in flood occurrence or magnitude are coherent in space has hardly been addressed in quantitative terms. We investigate this question for Germany by analysing fluctuations in annual maximum series (AMS) values at 68 discharge gauges for the common time period 1932-2005. We find remarkable spatial coherence across Germany given its different flood regimes. For example, there is a tendency that flood-rich/-poor years in sub-catchments of the Rhine basin, which are dominated by winter floods, coincide with flood-rich/-poor years in the southern sub-catchments of the Danube basin, which have their dominant flood season in summer. Our findings indicate that coherence is caused rather by persistence in catchment wetness than by persistent periods of higher/lower event precipitation. Further, we propose to differentiate between event-type and non-event-type coherence. There are quite a number of hydrological years with considerable non-event-type coherence, i.e. AMS values of the 68 gauges are spread out through the year but in the same magnitude range. Years with extreme flooding tend to be of event-type and non-coherent, i.e. there is at least one precipitation event that affects many catchments to various degree. Although spatial coherence is a remarkable phenomenon, and large-scale flooding across Germany can lead to severe situations, extreme magnitudes across the whole country within one event or within one year were not observed in the investigated period.

  7. Transboundary water issues: The Ganga-Brahmaputra-Meghna River Basin

    International Nuclear Information System (INIS)

    Roy, Debasri; Goswami, A.B.; Bose, Balaram

    2004-01-01

    Sharing of water of transboundary rivers among riparian nations has become a cause of major concern in different parts of the globe for quite sometime. The issue in the recent decades has been transformed into a source of international tensions and disputes resulting in strained relationships between riparian nations. Conflicts over sharing of water of the international rivers, like the Tigris, Euphrates and Jordan in the Middle East, the Nile in Northern Africa, the Mekong in South-East Asia, the Ganga-Brahmaputra-Meghna in the Indian subcontinent are widely known. The present paper discusses the water sharing -issue in the Ganga- Brahmaputra-Meghna basin located in the Indian sub continent covering five sovereign countries (namely India, Nepal, China, Bhutan and Bangladesh). Rapidly growing population, expanding agricultural and industrial activities besides the impacts of climate change have resulted in stressed condition in the arena of fresh water availability in the basin. Again occurrence of arsenic in sub-surface water in the lower reaches of the basin in India and Bangladesh has also added a new dimension to the problem. All the rivers of the GBM system exhibit wide variations between peak and lean flows as major part of the basin belongs to the monsoon region, where 80%-90 % of annual rainfall is concentrated in 4-5 months of South -West monsoon in the subcontinent. Over and above, the rivers in GBM system carry huge loads of sediments along with the floodwater and receive huge quantum of different kinds of wastes contaminating the water of the rivers. Again high rate of sedimentation of the major rivers and their tributaries have been affecting not only the carrying capacity of the rivers but also drastically reduced their retention capacity. Almost every year during monsoon about 27% and nearly 60% of the GBM basin lying in India and Bangladesh respectively experience flood. The year round navigation in many rivers has also been affected. All these have

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

    Directory of Open Access Journals (Sweden)

    Y. Kwak

    2015-06-01

    Full Text Available 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.

  9. Household flood risk reduction in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Duží, Barbora; Vikhrov, Dmytro; Kelman, I.; Stojanov, Robert; Jakubínský, Jiří

    2015-01-01

    Roč. 18, č. 8 (2015), s. 1-6 ISSN 1381-2386 R&D Projects: GA MŠk(CZ) EE2.4.31.0056; GA MŠk(CZ) LD13032; GA MŠk(CZ) LD13033 Institutional support: RVO:67179843 Keywords : Bečva River Basin * Czech Republic * flood risk reduction * floods * household adaptation * household coping Subject RIV: AO - Sociology, Demography Impact factor: 3.085, year: 2015

  10. Evaluation of extensive floods in western/central Europe

    Czech Academy of Sciences Publication Activity Database

    Gvoždíková, B.; Müller, Miloslav

    2017-01-01

    Roč. 21, č. 7 (2017), s. 3715-3725 ISSN 1027-5606 R&D Projects: GA ČR GA17-23773S Institutional support: RVO:68378289 Keywords : June 2013 flood * extreme floods * river-basin * climate * events * precipitation * Germany * Britain * example * model Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Hydrology Impact factor: 4.437, year: 2016 https://www.hydrol-earth-syst-sci.net/21/3715/2017/hess-21-3715-2017.pdf

  11. Fall 1982 Retention Study.

    Science.gov (United States)

    Peralta Community Coll. District, Oakland, CA. Office of Research, Planning and Development.

    In fall 1982, a study was conducted in the Peralta Community College District (PCCD) using withdrawal and grade distribution data to analyze student retention patterns. Successful retention rates were based on the percentage of students who received a passing grade, while total retention rates were based on the percentage of students who received…

  12. Fall 1984 Retention Study.

    Science.gov (United States)

    Peralta Community Coll. District, Oakland, CA. Office of Research, Planning and Development.

    A study was conducted of the retention patterns of students enrolled in the Peralta Community College District (PCCD) in fall 1984 using college reports on withdrawals and grade distributions. The study focused on successful retention (i.e., all students who received a passing grade) and on total retention (i.e., all students who received any…

  13. Base Flood Elevation

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  14. Flood Hazard Boundaries

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  15. Flood Control Structures

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  16. Flood Hazard Area

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision...

  17. Unexpected flood loss correlations across Europe

    Science.gov (United States)

    Booth, Naomi; Boyd, Jessica

    2017-04-01

    Floods don't observe country borders, as highlighted by major events across Europe that resulted in heavy economic and insured losses in 1999, 2002, 2009 and 2013. Flood loss correlations between some countries occur along multi-country river systems or between neighbouring nations affected by the same weather systems. However, correlations are not so obvious and whilst flooding in multiple locations across Europe may appear independent, for a re/insurer providing cover across the continent, these unexpected correlations can lead to high loss accumulations. A consistent, continental-scale method that allows quantification and comparison of losses, and identifies correlations in loss between European countries is therefore essential. A probabilistic model for European river flooding was developed that allows estimation of potential losses to pan-European property portfolios. By combining flood hazard and exposure information in a catastrophe modelling platform, we can consider correlations between river basins across Europe rather than being restricted to country boundaries. A key feature of the model is its statistical event set based on extreme value theory. Using historical river flow data, the event set captures spatial and temporal patterns of flooding across Europe and simulates thousands of events representing a full range of possible scenarios. Some known correlations were identified, such as between neighbouring Belgium and Luxembourg where 28% of events that affect either country produce a loss in both. However, our model identified some unexpected correlations including between Austria and Poland, and Poland and France, which are geographically distant. These correlations in flood loss may be missed by traditional methods and are key for re/insurers with risks in multiple countries. The model also identified that 46% of European river flood events affect more than one country. For more extreme events with a return period higher than 200 years, all events

  18. Flood Risk Regional Flood Defences : Technical report

    NARCIS (Netherlands)

    Kok, M.; Jonkman, S.N.; Lendering, K.T.

    2015-01-01

    Historically the Netherlands have always had to deal with the threat of flooding, both from the rivers and the sea as well as from heavy rainfall. The country consists of a large amount of polders, which are low lying areas of land protected from flooding by embankments. These polders require an

  19. An Economic Assessment of Local Farm Multi-Purpose Surface Water Retention Systems under Future Climate Uncertainty

    Directory of Open Access Journals (Sweden)

    Pamela Berry

    2017-03-01

    Full Text Available Regions dependent on agricultural production are concerned about the uncertainty associated with climate change. Extreme drought and flooding events are predicted to occur with greater frequency, requiring mitigation strategies to reduce their negative impacts. Multi-purpose local farm water retention systems can reduce water stress during drought periods by supporting irrigation. The retention systems’ capture of excess spring runoff and extreme rainfall events also reduces flood potential downstream. Retention systems may also be used for biomass production and nutrient retention. A sub-watershed scale retention system was analysed using a dynamic simulation model to predict the economic advantages in the future. Irrigated crops using water from the downstream reservoir at Pelly’s Lake, Manitoba, Canada, experienced a net decrease in gross margin in the future due to the associated irrigation and reservoir infrastructure costs. However, the multi-purpose benefits of the retention system at Pelly’s Lake of avoided flood damages, nutrient retention, carbon sequestration, and biomass production provide an economic benefit of $25,507.00/hectare of retention system/year. Multi-purpose retention systems under future climate uncertainty provide economic and environmental gains when used to avoid flood damages, for nutrient retention and carbon sequestration, and biomass production. The revenue gained from these functions can support farmers willing to invest in irrigation while providing economic and environmental benefits to the region.

  20. Flood-frequency characteristics of Wisconsin streams

    Science.gov (United States)

    Walker, John F.; Peppler, Marie C.; Danz, Mari E.; Hubbard, Laura E.

    2017-05-22

    Flood-frequency characteristics for 360 gaged sites on unregulated rural streams in Wisconsin are presented for percent annual exceedance probabilities ranging from 0.2 to 50 using a statewide skewness map developed for this report. 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 the equations presented in this report. The State was divided into eight areas of similar physiographic characteristics. The most significant basin characteristics are drainage area, soil saturated hydraulic conductivity, main-channel slope, and several land-use variables. The standard error of prediction for the equation for the 1-percent annual exceedance probability flood ranges from 56 to 70 percent for Wisconsin Streams; these values are larger than results presented in previous reports. The increase in the standard error of prediction is likely due to increased variability of the annual-peak discharges, resulting in increased variability in the magnitude of flood peaks at higher frequencies. For each of the unregulated rural streamflow-gaging stations, a weighted estimate based on the at-site log Pearson type III analysis and the multiple regression results was determined. The weighted estimate generally has a lower uncertainty than either the Log Pearson type III or multiple regression estimates. For regulated streams, a graphical method for estimating flood-frequency characteristics was developed from the relations of discharge and drainage area for selected annual exceedance probabilities. Graphs for the major regulated streams in Wisconsin are presented in the report.

  1. Flood Wave Propagation

    Indian Academy of Sciences (India)

    I available for forecasting the propagation of the flood wave. Introduction. Among all natural disasters, floods are the most frequently occurring phenomena that affect a large section of population all over the world, every year. Throughout the last century, flood- ing has been one of the most devastating disasters both in terms.

  2. Future flood risk estimates along the river Rhine

    Directory of Open Access Journals (Sweden)

    A. H. te Linde

    2011-02-01

    Full Text Available In Europe, water management is moving from flood defence to a risk management approach, which takes both the probability and the potential consequences of flooding into account. It is expected that climate change and socio-economic development will lead to an increase in flood risk in the Rhine basin. To optimize spatial planning and flood management measures, studies are needed that quantify future flood risks and estimate their uncertainties. In this paper, we estimated the current and future fluvial flood risk in 2030 for the entire Rhine basin in a scenario study. The change in value at risk is based on two land-use projections derived from a land-use model representing two different socio-economic scenarios. Potential damage was calculated by a damage model, and changes in flood probabilities were derived from two climate scenarios and hydrological modeling. We aggregated the results into seven sections along the Rhine. It was found that the annual expected damage in the Rhine basin may increase by between 54% and 230%, of which the major part (~ three-quarters can be accounted for by climate change. The highest current potential damage can be found in the Netherlands (110 billion €, compared with the second (80 billion € and third (62 billion € highest values in two areas in Germany. Results further show that the area with the highest fluvial flood risk is located in the Lower Rhine in Nordrhein-Westfalen in Germany, and not in the Netherlands, as is often perceived. This is mainly due to the higher flood protection standards in the Netherlands as compared to Germany.

  3. Flood basalt volcanism on the Moon and Mars

    International Nuclear Information System (INIS)

    Benes, K.

    1979-01-01

    Comparative studies of the surfaces of the terrestrial planets reveal that processes of flood basalt volcanism were common to all of them, irrespective of their stages of evolution either primitive, intermediate or progressive. On the Moon manifestations of flood basalt volcanism have been recognized in basins (maria); on the planet Mars both in basins (planitiae) and in higher topographic (continental) levels. The mare-epoch of the less developed planets led to significant changes in their relief and in the crustal structure. Examples of volcanic flows from the lunar and martian surface are introduced. Some crustal uplifts on Mars can be interpreted in terms of Van Bemmelen's undations. (Auth.)

  4. Flood risk assessment and mapping for the Lebanese watersheds

    Science.gov (United States)

    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

  5. Carbon Dynamics and Export from Flooded Wetlands: A Modeling Approach

    Science.gov (United States)

    Described in this article is development and validation of a process based model for carbon cycling in flooded wetlands, called WetQual-C. The model considers various biogeochemical interactions affecting C cycling, greenhouse gas emissions, organic carbon export and retention. ...

  6. A Comparative Study on Flood Management in China and Japan

    Directory of Open Access Journals (Sweden)

    Guangwei Huang

    2014-09-01

    Full Text Available Attempts at flood management during the 20th century resulted in more flood disasters. To gain a better understanding of what went wrong, it is necessary to examine historical evidence, seek ancient wisdom and compare practices of flood management in different countries. This study examines flood management concepts and practices in China and Japan during different periods of time in history and the differences in the two countries’ current management of flood retarding basins. It reveals that during the Western Han Dynasty (206 BC–24 AD, China proposed to redirect a river course to gain sufficient flood retarding capacity, and this same concept was realized, either coincidentally or intentionally, during the Edo period of Japan (1603–1868. In modern times, however, the management of flood retarding basins differs fundamentally between China and Japan. In addition, this study investigates the differences in emergency evacuation practices between China and Japan. This is the first study to highlight the link between a Chinese concept and a Japanese practice that are separated by more than 1000 years.

  7. Urban pluvial flood prediction

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  8. A simplified GIS-based model for large wood recruitment and connectivity in mountain basins

    Science.gov (United States)

    Lucía, Ana; Antonello, Andrea; Campana, Daniela; Cavalli, Marco; Crema, Stefano; Franceschi, Silvia; Marchese, Enrico; Niedrist, Martin; Schneiderbauer, Stefan; Comiti, Francesco

    2014-05-01

    The mobilization of large wood (LW) elements in mountain rivers channels during floods may increase their hazard potential, especially by clogging narrow sections such as bridges. However, the prediction of LW transport magnitude during flood events is a challenging topic. Although some models on LW transport have been recently developed, the objective of this work was to generate a simplified GIS-based model to identify along the channel network the most likely LW-related critical sections during high-magnitude flood events in forested mountain basins. Potential LW contribution generated by landsliding occurring on hillslopes is assessed using SHALSTAB stability model coupled to a GIS-based connectivity index, developed as a modification of the index proposed by Cavalli et al (2013). Connected slope-derived LW volumes are then summed at each raster cell to LW volumes generated by bank erosion along the erodibile part of river corridors, where bank erosion processes are estimated based on user-defined channel widening ratios stemming from observations following recent extreme events in mountain basins. LW volume in the channel is then routed through the stream network applying simple Boolean rules meant to capture the most important limiting transport condition in these high-energy systems at flood stage, i.e. flow width relative to log length. In addition, the role of bridges and retention check-dams in blocking floating logs is accounted for in the model, in particular bridge length and height are used to characterize their clogging susceptibility for different levels of expected LW volumes and size. The model has been tested in the Rienz and Ahr basins (about 630 km2 each), located in the Eastern Italian Alps. Sixty percent of the basin area is forested, and elevations range from 811 m a.s.l. to 3488 m a.s.l.. We used a 2.5 m resolution DTM and DSM, and their difference was used to calculate the canopy height. Data from 35 plots of the National Forest Inventory

  9. Flood Risk Management in Iowa through an Integrated Flood Information System

    Science.gov (United States)

    Demir, Ibrahim; Krajewski, Witold

    2013-04-01

    The Iowa Flood Information System (IFIS) is a web-based platform developed by the Iowa Flood Center (IFC) to provide access to flood inundation maps, real-time flood conditions, flood forecasts both short-term and seasonal, flood-related data, information and interactive visualizations for communities in Iowa. The key element of the system's architecture is the notion of community. Locations of the communities, those near streams and rivers, define basin boundaries. The IFIS provides community-centric watershed and river characteristics, weather (rainfall) conditions, and streamflow data and visualization tools. Interactive interfaces allow access to inundation maps for different stage and return period values, and flooding scenarios with contributions from multiple rivers. Real-time and historical data of water levels, gauge heights, and rainfall conditions are available in the IFIS by streaming data from automated IFC bridge sensors, USGS stream gauges, NEXRAD radars, and NWS forecasts. Simple 2D and 3D interactive visualizations in the IFIS make the data more understandable to general public. Users are able to filter data sources for their communities and selected rivers. The data and information on IFIS is also accessible through web services and mobile applications. The IFIS is optimized for various browsers and screen sizes to provide access through multiple platforms including tablets and mobile devices. The IFIS includes a rainfall-runoff forecast model to provide a five-day flood risk estimate for around 1100 communities in Iowa. Multiple view modes in the IFIS accommodate different user types from general public to researchers and decision makers by providing different level of tools and details. River view mode allows users to visualize data from multiple IFC bridge sensors and USGS stream gauges to follow flooding condition along a river. The IFIS will help communities make better-informed decisions on the occurrence of floods, and will alert

  10. Floods characterization: from impact data to quantitative assessment

    Science.gov (United States)

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

    2015-04-01

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

  11. Hydric potential of the river basin: Prądnik, Polish Highlands

    Science.gov (United States)

    Lepeška, Tomáš; Radecki-Pawlik, Artur; Wojkowski, Jakub; Walega, Andrzej

    2017-12-01

    Human society deals with floods, drought and water pollution. Facing those problems, the question how to prevent or at least to minimalize the adverse effects of water-related issues is asked of the landscape managers. In this way, any help given to landscape managers seems to be an additional useful tool. Within this paper, an approach leading to mitigation of water-related problems is presented that relates the retention of precipitation and the use of ecosystems as a tool for improving the quality, quantity of water resources and availability throughout the region. One approach is the determination of the landscape's hydric potential (LHP). This study examines one example of using this method within the conditions of Poland. The results of the research show that national data are entirely appropriate for implementation of the LHP method. Further, this approach revealed the classes of the hydric potential of the Prądnik river basin which was selected as the experimental territory. LHP results reflect the ecosystem attributes of the model river basin; areas of average LHP cover 63.26%, areas of high and limited hydric potential cover approximately 18.3% each. The spatial distribution of LHP means the results of this study provide a baseline for management of the river basin.

  12. Flood risk assessment of land pollution hotspots

    Science.gov (United States)

    Masi, Matteo; Arrighi, Chiara; Iannelli, Renato

    2017-04-01

    Among the risks caused by extreme events, the potential spread of pollutants stored in land hotspots due to floods is an aspect that has been rarely examined with a risk-based approach. In this contribution, an attempt to estimate pollution risks related to flood events of land pollution hotspots was carried out. Flood risk has been defined as the combination of river flood hazard, hotspots exposure and vulnerability to contamination of the area, i.e. the expected severity of the environmental impacts. The assessment was performed on a geographical basis, using geo-referenced open data, available from databases of land management institutions, authorities and agencies. The list of land pollution hotspots included landfills and other waste handling facilities (e.g., temporary storage, treatment and recycling sites), municipal wastewater treatment plants, liquid waste treatment facilities and contaminated sites. The assessment was carried out by combining geo-referenced data of pollution hotspots with flood hazard maps. We derived maps of land pollution risk based on geographical and geological properties and source characteristics available from environmental authorities. These included information about soil particle size, soil hydraulic conductivity, terrain slope, type of stored pollutants, the type of facility, capacity, size of the area, land use, etc. The analysis was carried out at catchment scale. The case study of the Arno river basin in Tuscany (central Italy) is presented.

  13. ENSO impacts on flood risk at the global scale

    Science.gov (United States)

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

    2014-05-01

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

  14. Late Holocene flood probabilities in the Black Hills, South Dakota with emphasis on the Medieval Climate Anomaly

    Science.gov (United States)

    Harden, Tessa M.; O'Connor, James E.; Driscoll, Daniel G.

    2015-01-01

    A stratigraphic record of 35 large paleofloods and four large historical floods during the last 2000 years for four basins in the Black Hills of South Dakota reveals three long-term flooding episodes, identified using probability distributions, at A.D.: 120–395, 900–1290, and 1410 to present. During the Medieval Climate Anomaly (~ A.D. 900–1300) the four basins collectively experienced 13 large floods compared to nine large floods in the previous 800 years, including the largest floods of the last 2000 years for two of the four basins. This high concentration of extreme floods is likely caused by one or more of the following: 1) instability of air masses caused by stronger than normal westerlies; 2) larger or more frequent hurricanes in the Gulf of Mexico and Atlantic Ocean; and/or 3) reduced land covering vegetation or increased forest fires caused by persistent regional drought.

  15. SOME ASPECTS OF HYDROLOGICAL RISK MANIFESTATION IN JIJIA BASIN

    Directory of Open Access Journals (Sweden)

    D. BURUIANĂ

    2012-03-01

    Full Text Available Jijia river basin surface geographically fits in Moldavian Plateau, Plain of Moldavia subunit. Being lowered by 200 to 300 m compared to adjacent subunits, it appears as a depression with altitudes between 270-300 m.Through its position in the extra-Carpathian region, away from the influence of oceanic air masses, but wide open to the action of air masses of eastern, north-eastern and northern continental origin, Jijia basin receives precipitations which vary according to the average altitude differing from the northern to the southern part of the basin (564 mm in north, 529.4 mm in Iasi. A characteristic phenomenon to the climate is represented by the torrential rains in the hot season, under the form of rain showers with great intensity, fact that influences the drainage of basin rivers. Jijia hydrographic basin is characterized by frequent and sharp variations of flow volumes and levels which lead to floods and flooding throughout the basin. The high waters generally occur between March and June, when approximately 70% of the annual stock is transported. The paper analyzes the main causes and consequences of flooding in the studied area, also identifying some structural and non-structural measures of flood protection applied by authorities in Jijia hydrographic basin. As a case study, the flood recorded in Dorohoi in June 28-29, 2010 is presented.

  16. Urban flash flood vulnerability : spatial assessment and adaptation : a case study in Istanbul, Turkey

    NARCIS (Netherlands)

    Reyes-Acevedo, Martin Alejandro; Flacke, J.; Brussel, M.J.G.

    2011-01-01

    The Ayamama River basin in Istanbul is a densely populated urban area that is frequently impacted by flash floods causing damage to people and infrastructure. The IPCC expects that under climate change conditions, more intense precipitation will occur, leading to a higher risk of flash floods.

  17. Flood Hazard Recurrence Frequencies for C-, F-, E-, S-, H-, Y-, and Z-Areas

    International Nuclear Information System (INIS)

    Chen, K.F.

    1999-01-01

    A method was developed to determine the probabilistic flood elevation curves for Savannah River Site facilities. This report presents the method used to determine the probabilistic flood elevation curves for C-, F-, E-, H-, S-, Y-, and Z-Areas due to runoff from the Upper Three Runs and Fourmile Branch basins

  18. Understanding the Unusual 2017 Monsoon and Floods in South Asia

    Science.gov (United States)

    Akanda, A. S.; Palash, W.; Hasan, M. A.; Nusrat, F.

    2017-12-01

    Driven primarily by the South Asian Monsoon, the Ganges-Brahmaputra-Meghna (GBM) river basin system collectively drains intense precipitation for an area of more than 1.5 million square kilometers during the wet summer season. Bangladesh, being the lowest riparian country in the system, experiences recurrent floods and immense suffering to its population. The 2017 monsoon season was quite unusual in terms of the characteristics of the precipitation received in the basin. The monsoon was spread out over a much larger time span (April-October) compared to the average monsoon season (June-September). Although the monsoon does not typically start until June in Bangladesh, the 2017 season started much earlier in April with unusually heavy precipitation in the Meghna basin region and caused major damage to agriculture in northeastern Bangladesh. The rainfall continued in several record-breaking pulses, compared to the typical one or two large waves. One of the largest pulses occurred in early August with very high in intensity and volume, causing ECMWF to issue a major warning about widespread flooding in Bangladesh, Northern India, and Eastern Nepal. This record flood event impacted over 40 million people in the above regions, causing major damage to life and infrastructure. Although the Brahmaputra rose above the danger level several times this season, the Ganges was unusually low, thus sparing downstream areas from disastrous floods. However, heavy precipitation continued until October, causing urban flooding in Dhaka and Chittagong - and worsening sanitation and public health conditions in southern Bangladesh - currently undergoing a terrible humanitarian crisis involving Rohingya refugees from the Myanmar. Despite marked improvement in flood forecasting systems in recent years, the 2017 floods identified critical gaps in our understanding of the flooding phenomena and limitations of dissemination in these regions. In this study, we investigate 1) the unusual

  19. A new French flash flood warning service

    Directory of Open Access Journals (Sweden)

    de Saint-Aubin Céline

    2016-01-01

    Full Text Available The French State services in charge of flood forecasting supervise about 22,000 km among the 120,000 km of the French rivers within a warning procedure called Vigilance Crues (http://www.vigicrues.gouv.fr. Some recent dramatic flood events on small watershed not covered by Vigilance Crues highlight the need for a new warning procedure to anticipate violent flash floods that regularly affect rapid river-basins. Thus the concept emerged of an automatic warning service specifically dedicated to local crisis managers. This service will be less elaborated than Vigilance Crues, probably with false alarms and missed events sometimes, but it will deliver a first information. The generation of the warning is based on a simple rainfall-runoff hydrological model developed by Irstea on all French rivers, fed with radar-gauge rainfall grids provided by Meteo-France. Every fifteen minutes, the hydrological model estimates the discharges on the rivers eligible to the service and determine if certain thresholds corresponding to a high or very high flood are likely to be exceeded. The last step of the real-time system is to determine which municipalities are concerned with flood risk and send them an automatic warning by voice call, optionally by sms or email. A specific web interface is available for users to monitor the evolution of the flood risk on maps that are updated every 15 minutes. This new flash flood warning service will be operational early 2017 as a free service for about 8,000 French municipalities.

  20. Appraisal of the Hydrological Potential of Ungauged Basin Using ...

    African Journals Online (AJOL)

    Analyses of these parameters provide the basis for demonstrating the effects of environmental controls on both the basin stream network system and for predicting the basin's output variables. Such information are essential and provide framework for improving agricultural activities, flood control and management measures ...

  1. Remodeling and Flood Forecasting due to Climate Change and Land Used:

    Science.gov (United States)

    Mohammad, Munira; Bárdossy, András.

    2010-05-01

    This study is to review the impact of climate change and land used on flooding through the SMART Project. It also simulate the Flood Forecasting in Klang River Basin in order to compare the changes in the existing river system in Klang River Basin with the Storm water Management and Road Tunnel (SMART) which is now already operating in the city center of Kuala Lumpur.The catchment area of the Klang River basin is 1,288 square kilometers (km2), and it is the most urbanized region in Malaysia, encompassing the Federal Territory of Kuala Lumpur and part of the state of Selangor. The basin spreads over nine local government authorities and faces serious environmental degradation and flooding problems from urbanization, industrialization, and population growth. More than half of the basin has been urbanized, and much of this continuing urban development has taken place on land that is prone to flooding. Flooding problem in Klang River Basin is still exist even measures and numerous flood mitigation projects and programs has been carried out by many parties. Even though that the new drainage guideline has been proposed since year 2000, flood reduction for Klang River basins is not successful enough. This problem contributed to the needs of this research to enhance the existing flood forecasting and mitigation project. This study analyzed and quantified the spatial patterns and time-variability of daily, monthly and yearly rainfall in Kuala Lumpur. An overview of rainfall patterns will be obtained through the analysis of 12 point data sources. Statistical properties of annual, monthly, and daily rainfall were derived. Spatial correlation fields for the annual and monthly rainfalls were studied.

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

    Science.gov (United States)

    Jain, Manoj; Parvaze, Sabah

    2017-04-01

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

  3. Quantifying flooding regime in floodplain forests to guide river restoration

    Science.gov (United States)

    Christian O. Marks; Keith H. Nislow; Francis J. Magilligan

    2014-01-01

    Determining the flooding regime needed to support distinctive floodplain forests is essential for effective river conservation under the ubiquitous human alteration of river flows characteristic of the Anthropocene Era. At over 100 sites throughout the Connecticut River basin, the largest river system in New England, we characterized species composition, valley and...

  4. The Total Risk Analysis of Large Dams under Flood Hazards

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2018-02-01

    Full Text Available Dams and reservoirs are useful systems in water conservancy projects; however, they also pose a high-risk potential for large downstream areas. Flood, as the driving force of dam overtopping, is the main cause of dam failure. Dam floods and their risks are of interest to researchers and managers. In hydraulic engineering, there is a growing tendency to evaluate dam flood risk based on statistical and probabilistic methods that are unsuitable for the situations with rare historical data or low flood probability, so a more reasonable dam flood risk analysis method with fewer application restrictions is needed. Therefore, different from previous studies, this study develops a flood risk analysis method for large dams based on the concept of total risk factor (TRF used initially in dam seismic risk analysis. The proposed method is not affected by the adequacy of historical data or the low probability of flood and is capable of analyzing the dam structure influence, the flood vulnerability of the dam site, and downstream risk as well as estimating the TRF of each dam and assigning corresponding risk classes to each dam. Application to large dams in the Dadu River Basin, Southwestern China, demonstrates that the proposed method provides quick risk estimation and comparison, which can help local management officials perform more detailed dam safety evaluations for useful risk management information.

  5. Comparison of flood regionalisation techniques in Lower Saxony.

    Science.gov (United States)

    Plötner, Stefan; Haberlandt, Uwe

    2016-04-01

    The index-flood method has become the standard method for peak flow regionalisation of given return periods at ungauged basins. Moreover grouping stations into regions of homogeneous flood characteristics increases the sample size and thus reduces the uncertainty of estimated peak flows even at gauged basins. At this context, this study investigates the performance of the index-flood method with regards to other regionalisation techniques and evaluates the influence of station density and data quality on the performance of the index-flood method. For this purpose 338 runoff stations in Lower Saxony with observed monthly peak flows and record lengths of annual peak flows between 10 and 75 years are analysed. Catchment descriptors of topography, soil, vegetation and climate are derived to group them into homogeneous regions. The regions are separated using 5 classification methods with 2 to 40 classes for selected catchment descriptors. The most suitable catchment descriptors are selected by their impact on classifying the mean annual peak flow and the variance of annual peak flows using random forest. Muliple linear regression, ordinary and external drift kriging, the standard and an extended index-flood method are compared with the at-site estimation as reference using cross-validation. Three station scenarios based on e.g. record length, known station specific experience and hydrological catchment complexity are used to evaluate the influence of station density and quality on the performance of the index-flood method. The results show the applicability of the index-flood method in Lower Saxony and the benefit of using regional samples for more robust estimations. Combining the index-flood method and geostatistics can improve the estimation of peak flows. The performance of the index-flood method is affected by the used sample respectively the selection of stations.

  6. Accounting for rainfall spatial variability in the prediction of flash floods

    Science.gov (United States)

    Saharia, Manabendra; Kirstetter, Pierre-Emmanuel; Gourley, Jonathan J.; Hong, Yang; Vergara, Humberto; Flamig, Zachary L.

    2017-04-01

    Flash floods are a particularly damaging natural hazard worldwide in terms of both fatalities and property damage. In the United States, the lack of a comprehensive database that catalogues information related to flash flood timing, location, causative rainfall, and basin geomorphology has hindered broad characterization studies. First a representative and long archive of more than 15,000 flooding events during 2002-2011 is used to analyze the spatial and temporal variability of flash floods. We also derive large number of spatially distributed geomorphological and climatological parameters such as basin area, mean annual precipitation, basin slope etc. to identify static basin characteristics that influence flood response. For the same period, the National Severe Storms Laboratory (NSSL) has produced a decadal archive of Multi-Radar/Multi-Sensor (MRMS) radar-only precipitation rates at 1-km spatial resolution with 5-min temporal resolution. This provides an unprecedented opportunity to analyze the impact of event-level precipitation variability on flooding using a big data approach. To analyze the impact of sub-basin scale rainfall spatial variability on flooding, certain indices such as the first and second scaled moment of rainfall, horizontal gap, vertical gap etc. are computed from the MRMS dataset. Finally, flooding characteristics such as rise time, lag time, and peak discharge are linked to derived geomorphologic, climatologic, and rainfall indices to identify basin characteristics that drive flash floods. The database has been subjected to rigorous quality control by accounting for radar beam height and percentage snow in basins. So far studies involving rainfall variability indices have only been performed on a case study basis, and a large scale approach is expected to provide a deeper insight into how sub-basin scale precipitation variability affects flooding. Finally, these findings are validated using the National Weather Service storm reports and a

  7. Extreme flood sensitivity to snow and forest harvest, western Cascades, Oregon, United States

    Science.gov (United States)

    Julia A. Jones; Reed M. Perkins

    2010-01-01

    We examined the effects of snow, event size, basin size, and forest harvest on floods using >1000 peak discharge events from 1953 to 2006 from three small 2), paired-watershed forest-harvest experiments and six large (60-600 km2) basins spanning the transient (400-800 m) and seasonal (>800 m) snow zones in the...

  8. Aqueduct Global Flood Analyzer - bringing risk information to practice

    Science.gov (United States)

    Ward, Philip

    2017-04-01

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

  9. Large Scale Processes and Extreme Floods in Brazil

    Science.gov (United States)

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

    2016-12-01

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

  10. Summary of floods in the United States during 1964

    Science.gov (United States)

    Rostvedt, J.O.

    1970-01-01

    This report describes the most outstanding floods in the United States during 1984. The four most damaging floods during the year were in December in the Far Western States, in March along the Ohio River, in September in central and northern Florida and southern Georgia, and in June in northwestern Montana.The floods of December in the Far Western States were the most damaging in the history of the area. Record-breaking discharges occurred in an unusually large area Oregon, northern California, western Nevada and Idaho, end southern Washington. Forty-seven lives were lost, and damage amounted to several hundred million dollars.Two storms in early March along the Ohio River caused maximum discharges of record on many streams in Ohio, Kentucky, and Indiana and also high dis- charges in parts of Illinois, West Virginia, and Pennsylvania. Eighteen lives were lost, and flood damage was about /$100 million.In September, Hurricane Dora, the first hurricane of record to cross north- eastern Florida from the Atlantic Ocean, caused outstanding floods in northern Florida and southern Georgia. Flood damage exceeded $100 million.The most severe floods of record in northwestern Montana occurred on both sides of the Continental Divide following heavy rains in early June. Thirty lives were lost, and flood damage was about /$55 million.About /$6 million damage resulted from severe flooding in a  small area in the Papillion Creek basin, in eastern Nebraska, in early June.In the last half of September, floods from torrential rains in three areas in Texas caused about $1 million damage.In addition to the floods mentiond above, 21 others of lesser magnitude are considered important enough to be included in this annual summary

  11. Nutrient removal using biosorption activated media: Preliminary biogeochemical assessment of an innovative stormwater infiltration basin

    International Nuclear Information System (INIS)

    O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Xuan, Zhemin; Harris, Willie G.

    2012-01-01

    Soil beneath a stormwater infiltration basin receiving runoff from a 23 ha predominantly residential watershed in north-central Florida, USA, was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.9:4.1 mixture (by volume) of tire crumb (to increase sorption capacity), silt and clay (to increase soil moisture retention), and sand (to promote sufficient infiltration), which was applied to develop an innovative stormwater infiltration basin utilizing nutrient reduction and flood control sub-basins. Comparison of nitrate/chloride (NO 3 − /Cl − ) ratios for the shallow groundwater indicates that prior to using BAM, NO 3 − concentrations were substantially influenced by nitrification or variations in NO 3 − input. In contrast, for the new basin utilizing BAM, NO 3 − /Cl − ratios indicate minor nitrification and NO 3 − losses with the exception of one summer sample that indicated a 45% loss. Biogeochemical indicators (denitrifier activity derived from real-time polymerase chain reaction and variations in major ions, nutrients, dissolved and soil gases, and stable isotopes) suggest that NO 3 − losses are primarily attributable to denitrification, whereas dissimilatory nitrate reduction to ammonium is a minor process. Denitrification was likely occurring intermittently in anoxic microsites in the unsaturated zone, which was enhanced by the increased soil moisture within the BAM layer and resultant reductions in surface/subsurface oxygen exchange that produced conditions conducive to increased denitrifier activity. Concentrations of total dissolved phosphorus and orthophosphate (PO 4 3− ) were reduced by more than 70% in unsaturated zone soil water, with the largest decreases in the BAM layer where sorption was the most likely mechanism for removal. Post-BAM PO 4 3− /Cl − ratios for shallow

  12. Technology basis for the Liquid Effluent Retention Facility Operating Specifications. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, P.G.

    1995-05-17

    The Liquid Effluent Retention Facility (LERF) consists of three retention basins, each with a nominal storage capacity of 6.5 million gallons. LERF serves as interim storage of 242-A Evaporator process condensate for treatment in the Effluent Treatment Facility. This document provides the technical basis for the LERF Operating Specifications, OSD-T-151-00029.

  13. Integrated studies of Azraq Basin in Jordan

    Science.gov (United States)

    Mohammed Shahbaz; B. Sunna

    2000-01-01

    Many historical indications of the eastern Mediterranean Basin exhibit climatic changes or alterations effecting the status of water resources, hence, effecting human-kind and the quality of life. It is essential to deeply understand the nature of climates and geological structures employing state of the art techniques to assess rainfall, runoff, and floods that...

  14. Effects of climate variability on global scale flood risk

    Science.gov (United States)

    Ward, P.; Dettinger, M. D.; Kummu, M.; Jongman, B.; Sperna Weiland, F.; Winsemius, H.

    2013-12-01

    In this contribution we demonstrate the influence of climate variability on flood risk. Globally, flooding is one of the worst natural hazards in terms of economic damages; Munich Re estimates global losses in the last decade to be in excess of $240 billion. As a result, scientifically sound estimates of flood risk at the largest scales are increasingly needed by industry (including multinational companies and the insurance industry) and policy communities. Several assessments of global scale flood risk under current and conditions have recently become available, and this year has seen the first studies assessing how flood risk may change in the future due to global change. However, the influence of climate variability on flood risk has as yet hardly been studied, despite the fact that: (a) in other fields (drought, hurricane damage, food production) this variability is as important for policy and practice as long term change; and (b) climate variability has a strong influence in peak riverflows around the world. To address this issue, this contribution illustrates the influence of ENSO-driven climate variability on flood risk, at both the globally aggregated scale and the scale of countries and large river basins. Although it exerts significant and widespread influences on flood peak discharges in many parts of the world, we show that ENSO does not have a statistically significant influence on flood risk once aggregated to global totals. At the scale of individual countries, though, strong relationships exist over large parts of the Earth's surface. For example, we find particularly strong anomalies of flood risk in El Niño or La Niña years (compared to all years) in southern Africa, parts of western Africa, Australia, parts of Central Eurasia (especially for El Niño), the western USA (especially for La Niña), and parts of South America. These findings have large implications for both decadal climate-risk projections and long-term future climate change

  15. Economic Assessment of Flood Control Facilities under Climate Uncertainty: A Case of Nakdong River, South Korea

    Directory of Open Access Journals (Sweden)

    Kyeongseok Kim

    2018-01-01

    Full Text Available Climate change contributes to enhanced flood damage that has been increasing for the last several decades. Understanding climate uncertainties improves adaptation strategies used for investment in flood control facilities. This paper proposes an investment decision framework for one flood zone to cope with future severe climate impacts. This framework can help policy-makers investigate the cost of future damage and conduct an economic assessment using real options under future climate change scenarios. The proposed methodology provides local municipalities with an adaptation strategy for flood control facilities in a flood zone. Using the proposed framework, the flood prevention facilities in the Nakdong River Basin of South Korea was selected as a case study site to analyze the economic assessment of the investments for flood control facilities. Using representative concentration pathway (RCP climate scenarios, the cost of future flood damage to 23 local municipalities was calculated, and investment strategies for adaptation were analyzed. The project option value was determined by executing an option to invest in an expansion that would adapt to floods under climate change. The results of the case study showed that the proposed flood facilities are economically feasible under both scenarios used. The framework is anticipated to present guidance for establishing investment strategies for flood control facilities of a flood zone in multiple municipalities’ settings.

  16. A Basin Approach to a Hydrological Service Delivery System in the Amur River Basin

    Directory of Open Access Journals (Sweden)

    Sergei Borsch

    2018-03-01

    Full Text Available This paper presents the basin approach to the design, development, and operation of a hydrological forecasting and early warning system in a large transboundary river basin of high flood potential, where accurate, reliable, and timely available daily water-level and reservoir-inflow forecasts are essential for water-related economic and social activities (the Amur River basin case study. Key aspects of basin-scale system planning and implementation are considered, from choosing efficient forecast models and techniques, to developing and operating data-management procedures, to disseminating operational forecasts using web-GIS. The latter, making the relevant forecast data available in real time (via Internet, visual, and well interpretable, serves as a good tool for raising awareness of possible floods in a large region with transport and industrial hubs located alongside the Amur River (Khabarovsk, Komsomolsk-on-Amur.

  17. Discover Floods Educators Guide

    Science.gov (United States)

    Project WET Foundation, 2009

    2009-01-01

    Now available as a Download! This valuable resource helps educators teach students about both the risks and benefits of flooding through a series of engaging, hands-on activities. Acknowledging the different roles that floods play in both natural and urban communities, the book helps young people gain a global understanding of this common--and…

  18. Landslides triggered by the storm of November 3-5, 1985, Wills Mountain Anticline, West Virginia and Virginia: Chapter C in Geomorphic studies of the storm and flood of November 3-5, 1985, in the upper Potomac and Cheat River basins in West Virginia and Virginia

    Science.gov (United States)

    Jacobson, Robert B.; McGeehin, John P.; Cron, Elizabeth D.; Carr, Carolyn E.; Harper, John M.; Howard, Alan D.

    1993-01-01

    allowed soil moisture to accumulate under the moderate intensities of the rainfall. Slopes covered by coarse, cobbly debris flow and alluvial deposits, mostly of Pleistocene age, were very stable due to their low slope angles and high frictional strength. For a particular bedrock lithology, the spatial distribution of landslides appears controlled by interdependent influences of slope morphology and land cover. On the Reedsville Shale, most landslides occurred on north- to northeast-facing slopes, which might have had higher antecedent levels of soil moisture; these slopes have also been preferentially cleared because they produce better pasture forage for livestock. A secondary concentration of landslides on south- to southwest-facing slopes cannot be explained by conventional soil-moisture models. Landslide density was 100--200 percent higher on cleared land than on forested land. On pastured land, most landslides occurred on laterally planar slopes, but on forested land, most landslides occurred in slope positions that were laterally concave (hillslope hollows). Compared with other documented Appalachian storms that have triggered landslides, the November 1985 storm had lower rainfall intensities over longer durations. Comparison with these other storms suggests that the anomalously high degree of slope instability in 1985 is due to the long duration of low-intensity rainfall on fine-grained regolith derived from shale; the triggering rainfall can be approximated by the 48-h storm total. Landslide density in Reedsville Shale regolith is linearly related to the varying 48-h rainfall along the anticline. These data define a probabilistic model that estimates return intervals of 43 to 300 yr for landslide densities ranging from 1 to 70 landslides/km2. Analysis of flood-induced geomorphic changes in 79 small drainage basins that received 210-240 mm of rainfall showed a clear local association between landslides and channel erosion or deposition adjacent to where the

  19. Flood action plans

    International Nuclear Information System (INIS)

    Slopek, R.J.

    1995-01-01

    Safe operating procedures developed by TransAlta Utilities for dealing with flooding, resulting from upstream dam failures or extreme rainfalls, were presented. Several operating curves developed by Monenco AGRA were described, among them the No Overtopping Curve (NOC), the Safe Filling Curve (SFC), the No Spill Curve (NSC) and the Guaranteed Fill Curve (GFC). The concept of an operational comfort zone was developed and defined. A flood action plan for all operating staff was created as a guide in case of a flooding incident. Staging of a flood action plan workshop was described. Dam break scenarios pertinent to the Bow River were developed for subsequent incorporation into a Flood Action Plan Manual. Evaluation of the technical presentations made during workshops were found them to have been effective in providing operating staff with a better understanding of the procedures that they would perform in an emergency. 8 figs

  20. Urinary retention in women.

    Science.gov (United States)

    Juma, Saad

    2014-07-01

    This review is a summary of the most pertinent published studies in the literature in the last 18 months that address cause, diagnosis, and management of urinary retention in women. Symptoms, uroflow, and pressure-flow studies have a low predictive value for and do not correlate with elevated postvoid residual urine (PVR). Anterior and posterior colporrhaphy do not cause de-novo bladder outlet obstruction in the majority of patients with elevated PVR, and the cause of elevated PVR may be other factors such as pain or anxiety causing abnormal relaxation of the pelvic floor and contributing to voiding difficulty. The risk of urinary retention in a future pregnancy after mid-urethral sling (MUS) is small. The risk of urinary tract infection and urinary retention after chemodenervation of the bladder with onabotulinumtoxin-A (100 IU) in patients with non-neurogenic urge incontinence is 33 and 5%, respectively. There is a lack of consensus among experts on the timing of sling takedown in the management of acute urinary retention following MUS procedures. There has been a significant progress in the understanding of the causation of urinary retention. Important areas that need further research (basic and clinical) are post-MUS and pelvic organ prolapse repair urinary retention and obstruction, and urinary retention owing to detrusor underactivity.

  1. FINANCING OF THE FLOOD DEFENSE IN DABULENI-CETATE AREA

    Directory of Open Access Journals (Sweden)

    Dorin COSMA

    2014-11-01

    Full Text Available Danube River Basin has been frequently affected by floods in the last decades which often gained historical meanings, the latest being recorded in 2006 and 2013. The material losses were very high and on the Cetate-Dabuleni sector of the Danube river, after the floods of 2006 the dikes have been damaged and partially destroyed. In the end the Rast locality was almost total relocated. Following these events, we need to rebuild the flood defense infrastructure in the Lower Danube, but after the first assessment the costs are very high. With this paper we propose the ways of funding the flood protection works on the Lower Danube, research being done on the Cetate-Dabuleni Danube's sector.

  2. Application of Artificial Neural Networks for estimating index floods

    Science.gov (United States)

    Šimor, Viliam; Hlavčová, Kamila; Kohnová, Silvia; Szolgay, Ján

    2012-12-01

    This article presents an application of Artificial Neural Networks (ANNs) and multiple regression models for estimating mean annual maximum discharge (index flood) at ungauged sites. Both approaches were tested for 145 small basins in Slovakia in areas ranging from 20 to 300 km2. Using the objective clustering method, the catchments were divided into ten homogeneous pooling groups; for each pooling group, mutually independent predictors (catchment characteristics) were selected for both models. The neural network was applied as a simple multilayer perceptron with one hidden layer and with a back propagation learning algorithm. Hyperbolic tangents were used as an activation function in the hidden layer. Estimating index floods by the multiple regression models were based on deriving relationships between the index floods and catchment predictors. The efficiencies of both approaches were tested by the Nash-Sutcliffe and a correlation coefficients. The results showed the comparative applicability of both models with slightly better results for the index floods achieved using the ANNs methodology.

  3. Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  4. The European Union approach to flood risk management and improving societal resilience: lessons from the implementation of the Floods Directive in six European countries

    Directory of Open Access Journals (Sweden)

    Sally J. Priest

    2016-12-01

    Full Text Available Diversity in flood risk management approaches is often considered to be a strength. However, in some national settings, and especially for transboundary rivers, variability and incompatibility of approaches can reduce the effectiveness of flood risk management. Placed in the context of increasing flood risks, as well as the potential for flooding to undermine the European Union's sustainable development goals, a desire to increase societal resilience to flooding has prompted the introduction of a common European Framework. We provide a legal and policy analysis of the implementation of the Floods Directive (2007/60/EC in six countries: Belgium (Flemish region, England, France, the Netherlands, Poland, and Sweden. Evaluation criteria from existing legal and policy literature frame the study of the Directive and its effect on enhancing or constraining societal resilience by using an adaptive governance approach. These criteria are initially used to analyze the key components of the EU approach, before providing insight of the implementation of the Directive at a national level. Similarities and differences in the legal translation of European goals into existing flood risk management are analyzed alongside their relative influence on policy and practice. The research highlights that the effect of the Floods Directive on increasing societal resilience has been nationally variable, in part because of its focus on procedural obligations, rather than on more substantive requirements. Analysis shows that despite a focus on transboundary river basin management, existing traditions of flood risk management have overridden objectives to harmonize flood risk management in some cases. The Directive could be strengthened by requiring more stringent cooperation and providing the competent authorities in international river basin districts with more power. Despite some shortcomings in directly affecting flood risk outcomes, the Directive has positively

  5. Synthetic generation of arbitrarily long series of flood hydrographs for flood risk assessment

    Science.gov (United States)

    Flores, Isabel; Sordo-Ward, Alvaro; Mediero, Luis; Garrote, Luis

    2013-04-01

    Flood risk assessment is an essential component of natural disaster management. Flood frequency analysis has traditionally been approached by fitting relatively short series of annual maxima of observations to a parametric probability distribution. Under this approach, only one relevant variable (usually peak discharge) can be analyzed, while in many practical applications, like dam safety analysis, the entire flood hydrograph is of interest. Obtaining a good representation of the ensemble of hydrographs would require extremely long historical flood series which almost never exist. Hydrometeorological modelling tools can be applied to extend the relatively short series of observations and generate an arbitrarily long series of synthetic events that can be used in flood risk assessment. The heavy computational burden of these processes requires the contribution of Information and Communication Technology (ICT) developments to enable the practical application of the hydrometeorological modelling chain for this purpose. In this paper, an example of this methodology is applied to the Santillana reservoir, located in the Manzanares basin, in Spain. The methodology is based on the Monte Carlo generation of synthetic hydrographs from rainstorms events extracted from arbitrarily long synthetic rainfall time series. The rainfall series are generated with the RainSim software, a model based on a spatial-temporal Neyman-Scott rectangular pulses process. The highest event of every year is chosen, based on three different criterions. The selected rainstorm events are transformed into runoff by the RIBS distributed rainfall-runoff event model, obtaining the ensemble of hydrographs which make possible to evaluate the associated flood risk. The procedure has been validated by comparing the observed flood frequency series in the Santillana reservoir with the synthetic ones, obtaining a good agreement.

  6. Flood quantile estimation at ungauged sites by Bayesian networks

    Science.gov (United States)

    Mediero, L.; Santillán, D.; Garrote, L.

    2012-04-01

    Estimating flood quantiles at a site for which no observed measurements are available is essential for water resources planning and management. Ungauged sites have no observations about the magnitude of floods, but some site and basin characteristics are known. The most common technique used is the multiple regression analysis, which relates physical and climatic basin characteristic to flood quantiles. Regression equations are fitted from flood frequency data and basin characteristics at gauged sites. Regression equations are a rigid technique that assumes linear relationships between variables and cannot take the measurement errors into account. In addition, the prediction intervals are estimated in a very simplistic way from the variance of the residuals in the estimated model. Bayesian networks are a probabilistic computational structure taken from the field of Artificial Intelligence, which have been widely and successfully applied to many scientific fields like medicine and informatics, but application to the field of hydrology is recent. Bayesian networks infer the joint probability distribution of several related variables from observations through nodes, which represent random variables, and links, which represent causal dependencies between them. A Bayesian network is more flexible than regression equations, as they capture non-linear relationships between variables. In addition, the probabilistic nature of Bayesian networks allows taking the different sources of estimation uncertainty into account, as they give a probability distribution as result. A homogeneous region in the Tagus Basin was selected as case study. A regression equation was fitted taking the basin area, the annual maximum 24-hour rainfall for a given recurrence interval and the mean height as explanatory variables. Flood quantiles at ungauged sites were estimated by Bayesian networks. Bayesian networks need to be learnt from a huge enough data set. As observational data are reduced, a

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  9. Assessing river regime alteration due to flood detention structures in dry and semi-dry regions

    Science.gov (United States)

    Yaraghi, Navid; Torabihaghighi, Ali; Ronkanen, Anna-Kaisa; Fazel, Nasim; Rossi, Pekka. M.; Klöve, Björn

    2017-04-01

    In dry and semi-dry climate, flood detention structures are used for flood control and managed aquifer recharge. These damps basin runoff response decreasing the maximum flows and increasing the runoff duration through wet seasons. In this study, a framework to quantify the role of flood detention dams in headwater tributaries on total water balance of major basin and alteration of flow pattern in the main river has been presented. The study contains four main subroutines: rainfall-runoff model, reservoir flood routing, river analysis system and seepage analysis. The flood hydrographs with different return periods are estimated based on the climatic data and geomorphology of headwater basin. River flow analysis below the flood detention structure is carried out for two unsteady flow scenarios, first with the hydrographs of natural system (as pre-impact: quick flood with significant peak flow) and second the routed hydrographs due to detention process in the reservoir (as post-impact: damped flood lower peak with longer duration time). Two sets of dynamic water surface along the river (from the location of detention structure (x=0) to the confluence point with main river (x=L) are developed based on two hydrologic conditions as results of river analysis system. The results of framework define the impact of flood detention structure by comparing the timing, magnitude and variability of flow. The Kamal Abad artificial groundwater recharge in Mahrloo Lake basin in Southern Iran was selected as case study to demonstrate the application of the created framework. Through the probability analysis, the return period for hydrological drought would be compared in pre and post impact condition. The results clearly showed how embankments influence floods in tributaries and in some cases the flow reduced significantly and disappears in tributaries.

  10. Forecast-based Integrated Flood Detection System for Emergency Response and Disaster Risk Reduction (Flood-FINDER)

    Science.gov (United States)

    Arcorace, Mauro; Silvestro, Francesco; Rudari, Roberto; Boni, Giorgio; Dell'Oro, Luca; Bjorgo, Einar

    2016-04-01

    Most flood prone areas in the globe are mainly located in developing countries where making communities more flood resilient is a priority. Despite different flood forecasting initiatives are now available from academia and research centers, what is often missing is the connection between the timely hazard detection and the community response to warnings. In order to bridge the gap between science and decision makers, UN agencies play a key role on the dissemination of information in the field and on capacity-building to local governments. In this context, having a reliable global early warning system in the UN would concretely improve existing in house capacities for Humanitarian Response and the Disaster Risk Reduction. For those reasons, UNITAR-UNOSAT has developed together with USGS and CIMA Foundation a Global Flood EWS called "Flood-FINDER". The Flood-FINDER system is a modelling chain which includes meteorological, hydrological and hydraulic models that are accurately linked to enable the production of warnings and forecast inundation scenarios up to three weeks in advance. The system is forced with global satellite derived precipitation products and Numerical Weather Prediction outputs. The modelling chain is based on the "Continuum" hydrological model and risk assessments produced for GAR2015. In combination with existing hydraulically reconditioned SRTM data and 1D hydraulic models, flood scenarios are derived at multiple scales and resolutions. Climate and flood data are shared through a Web GIS integrated platform. First validation of the modelling chain has been conducted through a flood hindcasting test case, over the Chao Phraya river basin in Thailand, using multi temporal satellite-based analysis derived for the exceptional flood event of 2011. In terms of humanitarian relief operations, the EO-based services of flood mapping in rush mode generally suffer from delays caused by the time required for their activation, programming, acquisitions and

  11. [Chronic monstrous urine retention].

    Science.gov (United States)

    Thomsen, Frederik Gustav; Holm, Mette Lind

    2015-01-26

    A 75-year-old male was diagnosed with renal mass at a computed tomography during an examination for extended abdominal girth. A large mesenterical cyst was also detected. The patient had infrequent voiding, which he had trained over many years as a taxi driver. A basic physical examination led to suspect urinary retention. His creatinine level was normal and he had no hydronephrosis. A renography showed equal function, but prolonged bilateral outflow. The volume extracted by urethral catheter passed 15 l. Absence of hydronephrosis and normal S-creatinine level has not been described in chronic urinary retention of this extent. Hydronephrosis is seen, but in much smaller volume of retention. Infrequent voiding is easily diagnosed. Urinary retention should be suspected when finding median cystic processes.

  12. Liquid Effluent Retention Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Liquid Effluent Retention Facility (LERF) is located in the central part of the Hanford Site. LERF is permitted by the State of Washington and has three liquid...

  13. Drug Retention Times

    Energy Technology Data Exchange (ETDEWEB)

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

  14. Flood Management in California

    Directory of Open Access Journals (Sweden)

    Jay R. Lund

    2012-02-01

    Full Text Available California’s development and success have been shaped by its ability to manage floods. This management has varied over the history of California’s economic and political development and continues in various forms today. California will always have flood problems. A range of options are available to aid in flood management problems and have been used over time. These options can be contrasted with flood management elsewhere and the types of options used to manage other types of hazards in California, such as earthquakes, wildfires, and droughts. In the future, flood management in California will require greater reliance on local funding and leadership, reflecting diminished federal and state funding, with more effective state and federal guidance. Effective flood management will also tend to integrate flood management with actions to achieve environmental and other water supply objectives, both to gain revenues from a broader range of beneficiaries as well as to make more efficient use of land and water in a state where both are often scarce.

  15. Building regional early flood warning systems by AI techniques

    Science.gov (United States)

    Chang, F. J.; Chang, L. C.; Amin, M. Z. B. M.

    2017-12-01

    Building early flood warning system is essential for the protection of the residents against flood hazards and make actions to mitigate the losses. This study implements AI technology for forecasting multi-step-ahead regional flood inundation maps during storm events. The methodology includes three major schemes: (1) configuring the self-organizing map (SOM) to categorize a large number of regional inundation maps into a meaningful topology; (2) building dynamic neural networks to forecast multi-step-ahead average inundated depths (AID); and (3) adjusting the weights of the selected neuron in the constructed SOM based on the forecasted AID to obtain real-time regional inundation maps. The proposed models are trained, and tested based on a large number of inundation data sets collected in regions with the most frequent and serious flooding in the river basin. The results appear that the SOM topological relationships between individual neurons and their neighbouring neurons are visible and clearly distinguishable, and the hybrid model can continuously provide multistep-ahead visible regional inundation maps with high resolution during storm events, which have relatively small RMSE values and high R2 as compared with numerical simulation data sets. The computing time is only few seconds, and thereby leads to real-time regional flood inundation forecasting and make early flood inundation warning system. We demonstrate that the proposed hybrid ANN-based model has a robust and reliable predictive ability and can be used for early warning to mitigate flood disasters.

  16. Challenges of torrential flood risk management in Serbia

    Directory of Open Access Journals (Sweden)

    Petrović Ana M.

    2015-01-01

    Full Text Available Torrential floods are the natural hydrological hazards manifesting as a consequence of extreme rainfall episodes which have a quick response from the watersheds of small areas, steep slopes and intensive soil erosion. Taking in consideration the nature of torrential flood (sudden and destructive occurrence and the fact they are the most frequent natural hazards in Serbia, torrential flood risk management is a real challenge. Instead of partial solutions for flood protection, integrated torrential flood risk management is more meaningful and effective. The key steps should be an improvement of the legal framework on national level and an expansion of technical and biological torrent control works in river basins. Consequences for society can be significantly reduced if there is an efficient forecast and timely warning, rescue and evacuation and if affected population is educated about flood risks and measures which can be undertaken in case of emergency situation. In this paper, all aspects of torrential flood risk management are analyzed. [Projekat Ministarstva nauke Republike Srbije, br. 47007 III

  17. Validation of remotely-sensed soil moisture in the absence of in situ soil moisture: the case of the Yankin Basin, a tributary of the Niger River basin

    CSIR Research Space (South Africa)

    Badou, DF

    2017-10-01

    Full Text Available Soil moisture is known to be important in hydrology, agronomy, floods and drought forecasting. Acquisition of in situ soil moisture data is time consuming, costly, and does not cover the scale required for basin analysis. The consideration...

  18. Health impacts of floods.

    Science.gov (United States)

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

    2010-01-01

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

  19. Flood insurance in Canada: implications for flood management and residential vulnerability to flood hazards.

    Science.gov (United States)

    Oulahen, Greg

    2015-03-01

    Insurance coverage of damage caused by overland flooding is currently not available to Canadian homeowners. As flood disaster losses and water damage claims both trend upward, insurers in Canada are considering offering residential flood coverage in order to properly underwrite the risk and extend their business. If private flood insurance is introduced in Canada, it will have implications for the current regime of public flood management and for residential vulnerability to flood hazards. This paper engages many of the competing issues surrounding the privatization of flood risk by addressing questions about whether flood insurance can be an effective tool in limiting exposure to the hazard and how it would exacerbate already unequal vulnerability. A case study investigates willingness to pay for flood insurance among residents in Metro Vancouver and how attitudes about insurance relate to other factors that determine residential vulnerability to flood hazards. Findings indicate that demand for flood insurance is part of a complex, dialectical set of determinants of vulnerability.

  20. Flood hazard mapping of Palembang City by using 2D model

    Science.gov (United States)

    Farid, Mohammad; Marlina, Ayu; Kusuma, Muhammad Syahril Badri

    2017-11-01

    Palembang as the capital city of South Sumatera Province is one of the metropolitan cities in Indonesia that flooded almost every year. Flood in the city is highly related to Musi River Basin. Based on Indonesia National Agency of Disaster Management (BNPB), the level of flood hazard is high. Many natural factors caused flood in the city such as high intensity of rainfall, inadequate drainage capacity, and also backwater flow due to spring tide. Furthermore, anthropogenic factors such as population increase, land cover/use change, and garbage problem make flood problem become worse. The objective of this study is to develop flood hazard map of Palembang City by using two dimensional model. HEC-RAS 5.0 is used as modelling tool which is verified with field observation data. There are 21 sub catchments of Musi River Basin in the flood simulation. The level of flood hazard refers to Head Regulation of BNPB number 2 in 2012 regarding general guideline of disaster risk assessment. The result for 25 year return per iod of flood shows that with 112.47 km2 area of inundation, 14 sub catchments are categorized in high hazard level. It is expected that the hazard map can be used for risk assessment.

  1. (Dahomey) Basin

    African Journals Online (AJOL)

    Timothy Ademakinwa

    13 km maximum width in the onshore at the basin axis along Nigerian and Republic of Benin boundary. This narrows westwards and eastwards to about 5 km (Coker and Ejedawe, 1987; Coker,. 2002). Detailed geology, evolution, stratigraphy and hydrocarbon occurrence of the basin have been described by Jones and ...

  2. FLOODPLAIN PLANNING BASED ON STATISTICAL ANALYSIS OF TILPARA BARRAGE DISCHARGE: A CASE STUDY ON MAYURAKSHI RIVER BASIN

    Directory of Open Access Journals (Sweden)

    Vibhash Chandra Jha

    2012-10-01

    Full Text Available Floods in the West Bengal are responsible for colossal loss of human life, crops, and property. In recent years, various measures of flood control and management have been adopted. However, flooding in such rivers like Brahmani profoundly challenges flood-hazard management, because of the inadequacy of conventional data and high spatio-temporal variability of floods. To understand flood hazards and environmental change it is imperative that engineers and hydrologists utilize historical and paleoflood records to improve risk analyses as well as to estimate probable maximum flood on rivers such as these in a highly flood-prone region(Parkar,2000. The flood frequency analysis, probable peak discharge analysis, its return period analysis and floodplain zoning based on ancillary data will help better management of flood in the Mayurakshi River basin situated in the districts of Birbhum and Murshidabad.

  3. New version of 1 km global river flood hazard maps for the next generation of Aqueduct Global Flood Analyzer

    Science.gov (United States)

    Sutanudjaja, Edwin; van Beek, Rens; Winsemius, Hessel; Ward, Philip; Bierkens, Marc

    2017-04-01

    The Aqueduct Global Flood Analyzer, launched in 2015, is an open-access and free-of-charge web-based interactive platform which assesses and visualises current and future projections of river flood impacts across the globe. One of the key components in the Analyzer is a set of river flood inundation hazard maps derived from the global hydrological model simulation of PCR-GLOBWB. For the current version of the Analyzer, accessible on http://floods.wri.org/#/, the early generation of PCR-GLOBWB 1.0 was used and simulated at 30 arc-minute ( 50 km at the equator) resolution. In this presentation, we will show the new version of these hazard maps. This new version is based on the latest version of PCR-GLOBWB 2.0 (https://github.com/UU-Hydro/PCR-GLOBWB_model, Sutanudjaja et al., 2016, doi:10.5281/zenodo.60764) simulated at 5 arc-minute ( 10 km at the equator) resolution. The model simulates daily hydrological and water resource fluxes and storages, including the simulation of overbank volume that ends up on the floodplain (if flooding occurs). The simulation was performed for the present day situation (from 1960) and future climate projections (until 2099) using the climate forcing created in the ISI-MIP project. From the simulated flood inundation volume time series, we then extract annual maxima for each cell, and fit these maxima to a Gumbel extreme value distribution. This allows us to derive flood volume maps of any hazard magnitude (ranging from 2-year to 1000-year flood events) and for any time period (e.g. 1960-1999, 2010-2049, 2030-2069, and 2060-2099). The derived flood volumes (at 5 arc-minute resolution) are then spread over the high resolution terrain model using an updated GLOFRIS downscaling module (Winsemius et al., 2013, doi:10.5194/hess-17-1871-2013). The updated version performs a volume spreading sequentially from more upstream basins to downstream basins, hence enabling a better inclusion of smaller streams, and takes into account spreading of water

  4. Continental Portuguese Territory Flood Susceptibility Index - contribution to a vulnerability index

    Science.gov (United States)

    Jacinto, R.; Grosso, N.; Reis, E.; Dias, L.; Santos, F. D.; Garrett, P.

    2015-08-01

    This work defines a national flood susceptibility index for the Portuguese continental territory, by proposing the aggregation of different variables which represent natural conditions for permeability, runoff and accumulation. This index is part of the national vulnerability index developed in the scope of Flood Maps in Climate Change Scenarios (CIRAC) project, supported by the Portuguese Association of Insurers (APS). This approach expands on previous works by trying to bridge the gap between different flood mechanisms (e.g. progressive and flash floods) occurring at different spatial scales in the Portuguese territory through (a) selecting homogeneously processed data sets and (b) aggregating their values to better translate the spatially continuous and cumulative influence in floods at multiple spatial scales. Results show a good ability to capture, in the higher susceptibility classes, different flood types: fluvial floods and flash floods. Lower values are usually related to mountainous areas, low water accumulation potential and more permeable soils. Validation with independent flood data sets confirmed these index characteristics, although some overestimation can be seen in the southern region of Alentejo where, due to a dense hydrographic network and an overall low slope, floods are not as frequent as a result of lower precipitation mean values. Future work will focus on (i) including extreme precipitation data sets to represent the triggering factor, (ii) improving representation of smaller and stepper basins, (iii) optimizing variable weight definition process and (iii) developing more robust independent flood validation data sets.

  5. Flood Inundation Mapping in the Logone Floodplain from Multi Temporal Landsat ETM+Imagery

    Science.gov (United States)

    Jung, Hahn Chul; Alsdorf, Douglas E.; Moritz, Mark; Lee, Hyongki; Vassolo, Sara

    2011-01-01

    Yearly flooding in the Logone floodplain makes an impact on agricultural, pastoral, and fishery systems in the Lake Chad Basin. Since the flooding extent and depth are highly variable, flood inundation mapping helps us make better use of water resources and prevent flood hazards in the Logone floodplain. The flood maps are generated from 33 multi temporal Landsat Enhanced Thematic Mapper Plus (ETM+) during three years 2006 to 2008. Flooded area is classified using a short-wave infrared band whereas open water is classified by Iterative Self-organizing Data Analysis (ISODATA) clustering. The maximum flooding extent in the study area increases up to approximately 5.8K km2 in late October 2008. The study also provides strong correlation of the flooding extents with water height variations in both the floodplain and the river based on a second polynomial regression model. The water heights are from ENIVSAT altimetry in the floodplain and gauge measurements in the river. Coefficients of determination between flooding extents and water height variations are greater than 0.91 with 4 to 36 days in phase lag. Floodwater drains back to the river and to the northeast during the recession period in December and January. The study supports understanding of the Logone floodplain dynamics in detail of spatial pattern and size of the flooding extent and assists the flood monitoring and prediction systems in the catchment.

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

    Directory of Open Access Journals (Sweden)

    Yiwen Mei

    2016-03-01

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

  7. Hydroclimatology of the Missouri River basin

    Science.gov (United States)

    Wise, Erika K.; Woodhouse, Connie A.; McCabe, Gregory; Pederson, Gregory T.; St. Jacques, Jeannine-Marie

    2018-01-01

    Despite the importance of the Missouri River for navigation, recreation, habitat, hydroelectric power, and agriculture, relatively little is known about the basic hydroclimatology of the Missouri River basin (MRB). This is of particular concern given the droughts and floods that have occurred over the past several decades and the potential future exacerbation of these extremes by climate change. Here, observed and modeled hydroclimatic data and estimated natural flow records in the MRB are used to 1) assess the major source regions of MRB flow, 2) describe the climatic controls on streamflow in the upper and lower basins , and 3) investigate trends over the instrumental period. Analyses indicate that 72% of MRB runoff is generated by the headwaters in the upper basin and by the lowest portion of the basin near the mouth. Spring precipitation and temperature and winter precipitation impacted by changes in zonal versus meridional flow from the Pacific Ocean play key roles in surface water supply variability in the upper basin. Lower basin flow is significantly correlated with precipitation in late spring and early summer, indicative of Atlantic-influenced circulation variability affecting the flow of moisture from the Gulf of Mexico. Although increases in precipitation in the lower basin are currently overriding the effects of warming temperatures on total MRB flow, the upper basin’s long-term trend toward decreasing flows, reduction in snow versus rain fraction, and warming spring temperatures suggest that the upper basin may less often provide important flow supplements to the lower basin in the future.

  8. Nitrogen Saturation in Highly Retentive Watersheds?

    Science.gov (United States)

    Daley, M. L.; McDowell, W. H.

    2009-12-01

    Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

  9. Localized Flood Management

    Science.gov (United States)

    practitioners will cover a range of practices that can help communities build flood resilience, from small scale interventions such as rain gardens and permeable pavement to coordinated open space and floodplain preservation

  10. Initial external events: floods

    International Nuclear Information System (INIS)

    Drumond, M.M.

    1989-12-01

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

  11. FLOODPLAIN, FLOOD COUNTY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Floodplain Mapping/Redelineation study deliverables depict and quantify the flood risks for the study area. The primary risk classifications used are the...

  12. Floods and Mold Growth

    Science.gov (United States)

    Mold growth may be a problem after flooding. Excess moisture in the home is cause for concern about indoor air quality primarily because it provides breeding conditions for pests, molds and other microorganisms.

  13. Lattice Boltzmann Method of a Flooding Accident at Gopeng, Perak, Malaysia

    Directory of Open Access Journals (Sweden)

    Siti Habibah Shafiai

    2017-01-01

    Full Text Available The extraordinary flood had hit the residential area at Taman Raia Mesra, Gopeng, Perak, Malaysia, in November 2016. The event illustrated how the river basin had been fully inundated due to the heavy rainfall and caused the overflow to this affected area. It was reported that the occurrence became worst as the outlet of retention pond which connects to the river is unsuitable for the water outflow. Henceforth, this paper attempts to evaluate the causal factor of this recent disaster by using a model developed from Lattice Boltzmann Method (LBM. The model also incorporated with the rainfall and stormwater in LABSWE™. The simulation was commenced with the basic tests for model validation comprising turbulent and jet-forced flow in a circular channel, which resulted in a good agreement for both models. The simulation continued by using LABSWE model to reveal the water depth and velocity profile at the study site. These results had proven the incompatibility size of the outlet pond which is too small for the water to flow out to the river. The study is capable of providing the authorities with a sustainable design of proper drainage system, especially in Malaysia which is constantly receiving the outrageous heavy rainfall.

  14. iFLOOD: A Real Time Flood Forecast System for Total Water Modeling in the National Capital Region

    Science.gov (United States)

    Sumi, S. J.; Ferreira, C.

    2017-12-01

    Extreme flood events are the costliest natural hazards impacting the US and frequently cause extensive damages to infrastructure, disruption to economy and loss of lives. In 2016, Hurricane Matthew brought severe damage to South Carolina and demonstrated the importance of accurate flood hazard predictions that requires the integration of riverine and coastal model forecasts for total water prediction in coastal and tidal areas. The National Weather Service (NWS) and the National Ocean Service (NOS) provide flood forecasts for almost the entire US, still there are service-gap areas in tidal regions where no official flood forecast is available. The National capital region is vulnerable to multi-flood hazards including high flows from annual inland precipitation events and surge driven coastal inundation along the tidal Potomac River. Predicting flood levels on such tidal areas in river-estuarine zone is extremely challenging. The main objective of this study is to develop the next generation of flood forecast systems capable of providing accurate and timely information to support emergency management and response in areas impacted by multi-flood hazards. This forecast system is capable of simulating flood levels in the Potomac and Anacostia River incorporating the effects of riverine flooding from the upstream basins, urban storm water and tidal oscillations from the Chesapeake Bay. Flood forecast models developed so far have been using riverine data to simulate water levels for Potomac River. Therefore, the idea is to use forecasted storm surge data from a coastal model as boundary condition of this system. Final output of this validated model will capture the water behavior in river-estuary transition zone far better than the one with riverine data only. The challenge for this iFLOOD forecast system is to understand the complex dynamics of multi-flood hazards caused by storm surges, riverine flow, tidal oscillation and urban storm water. Automated system

  15. EU Floods Directive implementation in Austria

    Directory of Open Access Journals (Sweden)

    Neuhold Clemens

    2016-01-01

    management. The obligation of reviewing the process on a regular basis and to revise the information if needed supports a sustainable approach by discussing the achievements and deficits transparently. The consideration of residual risk (overload and failure of flood defences and, hence, the incorporation to national legislation is of substantial relevance especially for awareness raising and public information and consultation. Concluding the implementation of the FD is very valuable for strategic planning (mid-term on national level which is then linked to existing and well-proven mechanisms of detailed planning and funding. The priorities are set on non-structural measures as well as measures fostering flood retention.

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

    Directory of Open Access Journals (Sweden)

    M. Egüen

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-06-01

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