WorldWideScience

Sample records for flood plain deposition

  1. Deposition of radiocesium on the river flood plains around Fukushima.

    Science.gov (United States)

    Saegusa, Hiromitsu; Ohyama, Takuya; Iijima, Kazuki; Onoe, Hironori; Takeuchi, Ryuji; Hagiwara, Hiroki

    2016-11-01

    The environment in the area around Fukushima Daiichi Nuclear Power Plant has been contaminated by widely deposited significant amount of radioactive materials, which were released to the atmosphere caused by the Fukushima Daiichi Nuclear Power Plant accident due to the Great East Japan Earthquake, which occurred on March 11, 2011. The radiocesium released in the accident mainly affects radiation dose in the environment. Decontamination work in the contaminated area except a mountain forests has been conducted to decrease the radiation dose. However, there are concerns that the redistribution of this radiation due to water discharge will occur due to the resulting transport of radiocesium. In particular, the deposition of soil particles containing radiocesium on the flood plains in the downstream areas of Fukushima's rivers can potentially increase the local radiation dose. Therefore, it is important to understand the influence of the deposition behavior of radiocesium on the radiation dose. Investigations of rivers have been performed to enhance the understanding of the mechanisms by which radiocesium is deposited on these flood plains. It was found that the spatial distribution of the radiocesium concentration on the flood plain along the river is heterogeneous with a dependence on the depositional condition and that the number of points with high air dose rates is limited. In detail, the radiocesium concentration and air dose rates in flood channels are higher than those at the edges of the river channels. Based on these heterogeneity and hydrological events, the deposition and transport mechanisms of the radiocesium due to water discharge at rivers were also interpreted, and a conceptual model was constructed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Application of flood index in monitoring Flood-plain ecosystems (by the example of the Middle Ob flood-plain)

    OpenAIRE

    Bolotnov, V. P.

    2007-01-01

    The concept of regional hydroecological monitoring has been developed for the flood-plain of the Middle Ob. Its object is to control the state of flood-plain ecosystem productivity for organization of scientific, regional-adopted and ecologically regulated nature management. For this purpose hydroecological zoning of flood-plain territory performed, the most representative stations of water-gauge observations for each flood-plain zone organized, the scheme of flood-plain flooding was prepared...

  3. Investigation of Soil Permeability and Hydrological Properties of Flood Plain Deposits of the Rio Grande in EL Paso TX

    Science.gov (United States)

    Schacht, D.; Jin, L.; Doser, D. I.

    2013-12-01

    The various soil types within the flood plains of Rio Grande in El Paso 's Lower Valley have long been utilized by local farmers. These soils are typically more conducive to farming than the more recent (Pliocene) sandy soils outside of the flood plain region. This project will explore the various properties of these soils types such as their grain size, depths, extent, and hydrological conductivity utilizing various geophysical and geochemical methods. The study site is located in El Paso 's Lower Valley and is situated in an actively farmed area. Soil maps from the Natural Resource Conservation Service (NRCS) and variations in vegetation growth will help delineate locations of soil types in the study area. The information that will be collected will produce baseline data to help track expected seasonal variations in the soil's moisture content and in the depth of the local water table. This project represents a collaboration between El Paso Community College's and the University of Texas at El Paso's Departments of Geological Sciences as a means for students majoring in Geological Sciences at El Paso Community College to gain hands on experience in researching geological issues through partnerships with their future institution and faculty.

  4. 44 CFR 10.14 - Flood plains and wetlands.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plains and wetlands. 10... Flood plains and wetlands. For any action taken by FEMA in a flood plain or wetland, the provisions of... Executive Order 11988, Flood Plain Management, and Executive Order 11990, Protection of Wetlands (44...

  5. 18 CFR 801.8 - Flood plain management and protection.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Flood plain management... COMMISSION GENERAL POLICIES § 801.8 Flood plain management and protection. (a) Periodic inundation of lands along waterways has not discouraged development of flood hazards areas. Major floods cause loss of...

  6. 7 CFR 650.25 - Flood-plain management.

    Science.gov (United States)

    2010-01-01

    ... valuable for maintaining agricultural and forest products for food and fiber, fish and wildlife habitat... flood plain. Department of Housing and Urban Development (HUD) flood insurance maps, other available... if the intended action is in the base flood plain by using HUD flood insurance maps, and other...

  7. 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.

  8. 2003 Pearl River County, Mississippi Lidar: Flood Plain Management Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This lidar data was collected primarily for flood plain mapping within Pearl River County, MS. The data were processed into separate Bare Earth and First Surface...

  9. Risks associated with rainfall and floods in the Moldavian Plain

    Directory of Open Access Journals (Sweden)

    Dan BURUIANĂ

    2015-03-01

    Full Text Available Climate changes, less effective land exploitation and insufficient security infrastructure against extreme phenomena induce vulnerabilities for the Moldavian Plain, where floods are relatively frequent. The middle and lower segments of the major streams dispose of improved hydro-technical infrastructure to prevent floods, still, the secondary streams and tributaries, with pronounced torrential characterremain vulnerable. The torrential character of the majority of rivers inthe Moldavian Plain results in management difficulties related with risksat maximum flow, especially on the first rank tributaries. Our studyanalyzes the main causes and consequences of floods in the MoldavianPlain and identifies potentially significant flood risks areas.

  10. Flood hydrology and methylmercury availability in coastal plain rivers.

    Science.gov (United States)

    Bradley, Paul M; Journey, Celeste A; Chapelle, Francis H; Lowery, Mark A; Conrads, Paul A

    2010-12-15

    Mercury (Hg) burdens in top-predator fish differ substantially between adjacent South Carolina Coastal Plain river basins with similar wetlands coverage. In the Congaree River, floodwaters frequently originate in the Blue Ridge and Piedmont regions, where wetlands coverage and surface water dissolved methylmercury (MeHg) concentrations are low. Piedmont-driven flood events can lead to downward hydraulic gradients in the Coastal Plain riparian wetland margins, inhibiting MeHg transport from wetland sediments, and decreasing MeHg availability in the Congaree River habitat. In the adjacent Edisto River basin, floodwaters originate only within Coastal Plain sediments, maintaining upward hydraulic gradients even during flood events, promoting MeHg transport to the water column, and enhancing MeHg availability in the Edisto River habitat. These results indicate that flood hydrodynamics contribute to the variability in Hg vulnerability between Coastal Plain rivers and that comprehensive regional assessment of the relationship between flood hydrodynamics and Hg risk in Coastal Plain streams is warranted.

  11. Flood hydrology and methylmercury availability in Coastal Plain rivers

    Science.gov (United States)

    Bradley, Paul M.; Journey, Celeste A.; Chapelle, Francis H.; Lowery, Mark A.; Conrads, Paul A.

    2010-01-01

    Mercury (Hg) burdens in top-predator fish differ substantially between adjacent South Carolina Coastal Plain river basins with similar wetlands coverage. In the Congaree River, floodwaters frequently originate in the Blue Ridge and Piedmont regions, where wetlands coverage and surface water dissolved methylmercury (MeHg) concentrations are low. Piedmont-driven flood events can lead to downward hydraulic gradients in the Coastal Plain riparian wetland margins, inhibiting MeHg transport from wetland sediments, and decreasing MeHg availability in the Congaree River habitat. In the adjacent Edisto River basin, floodwaters originate only within Coastal Plain sediments, maintaining upward hydraulic gradients even during flood events, promoting MeHg transport to the water column, and enhancing MeHg availability in the Edisto River habitat. These results indicate that flood hydrodynamics contribute to the variability in Hg vulnerability between Coastal Plain rivers and that comprehensive regional assessment of the relationship between flood hydrodynamics and Hg risk in Coastal Plain streams is warranted.

  12. Pennypack Watershed, Pennsylvania. Expanded Flood Plain Information.

    Science.gov (United States)

    1980-09-01

    individual cell regulatory agencies at the local, state and Federal damage functions to an index location within each level have recognized the need to...34." ; - . .. . . . .’" " ~ ENVIRONMENTAL EVALUATION General In addition to recognizing the flood hazard and functions such as storm water infiltration, flood...Alternative C land use wild mustard, milkweed , ironweed, bull thistle, plan, which represents the greatest density of future blackberry, barberry and

  13. 13 CFR 120.172 - Flood-plain and wetlands management.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Flood-plain and wetlands... Flood-plain and wetlands management. (a) All loans must conform to requirements of Executive Orders 11988, “Flood Plain Management” (3 CFR, 1977 Comp., p. 117) and 11990, “Protection of Wetlands” (3...

  14. Microbially mediated cycling of iron in flood plains and other wetlands

    Science.gov (United States)

    Szewzyk, Ulrich; Braun, Burga; Schmidt, Bertram; Schaudin, Christoph

    2010-05-01

    Floodplains are subjected to alternating changes of flooding and partly drying of the soil systems and are therefore prominent examples of ecosystems undergoing dramatic changes in redox conditions. During the last 5 years the flood plains and associated water systems of the National Park "Untere Oder" were examined for the presence and relevance of bacteria associated with the redox cycling of iron and manganese. Biofilms grown at different locations in the national park were used as source material for examinations on the diversity of iron bacteria. Besides classical microbiological cultivation techniques, culture independent methods were used to explore the phylogenetic diversity of bacteria in ochreous depositions. The natural grown biofilms were intensely examined and documented by light and scanning electron microscopy. Many of the classical morphotypes of iron bacteria were observed and documented. Parallel the biofilms were used for cultivation of iron related bacteria under various conditions. The 16s rDNA of the isolated strains was sequenced and phylogenetically affiliated. In addition, these biofilms were used for establishing 16S rDNA clone libraries. In comparison of the results from direct microscopic examinations, cultivation and culture independent detection methods (FISH) certain of the morphotypes from the biofilms could be assigned to phylogenetic lineages. Besides the biofilms from the Oder flood plains, ochreous depositing biofilms from Berlin drinking water wells, flood plains in Norway and various wetlands in terra de fuego were examined. The cultures and 16S rDNA-clones from the different sampling sites are being compared for biogeographic differences.

  15. Water impoundment modes of flood utilization for the Songnen Plain

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Taking the Songnen Plain as the research region and basing on the structural division of river water resources, the impounding models of flood water utilization are proposed. Considering the water requirement, potential impoundage and the degree of risk, two modes of the flood water utilization are developed: full impounding and partial impounding. A risk assessment method is put forward according to variation of the flood storage capacity before and after impounding water. A representative hydrological year is taken as an example to analyze the application of the model at the downstream of the Nenjiang River. It is found that the model is very useful for the flood utilization and protection. For flood utilization, the spring drought can be relieved and the risk of impounding water is also acceptable. For flood protection, the river flood peak can be largely reduced and the impounding water can increase the river discharge at the low water period, at the same time the structure of river water resources can be improved as well.

  16. Water impoundment modes of flood utilization for the Songnen Plain

    Institute of Scientific and Technical Information of China (English)

    XU ShiGuo; LI WenYi

    2008-01-01

    Taking the Songnen Plain as the research region and basing on the structural divi-sion of river water resources,the impounding models of flood water utilization are proposed.Considering the water requirement,potential impoundage and the de-gree of risk,two modes of the flood water utilization are developed:full impounding and partial impounding.A risk assessment method is put forward according to variation of the flood storage capacity before and after impounding water.A representative hydro-logical year is taken as an example to analyze the application of the model at the down-stream of the Nenjiang River.It is found that the model is very useful for the flood utiliza-tion and protection.For flood utilization,the spring drought can be relieved and the risk of impounding water is also acceptable.For flood protection,the river flood peak can be largely reduced and the impounding water can increase the river discharge at the low water period,at the same time the structure of river water resources can be improved as well.

  17. Costs of Placing Fill in a Flood Plain.

    Science.gov (United States)

    1975-05-01

    Computation 5 Engineering. Enviromental and Legal Aspects of Filling 6 STUDY CONCLUSIONS 8 APPENDIX "Guidelines for Filling Floodplains," Bauer Engineering...Various attempts have been made to estimate an economic value of the ecosystem and from this the economic loss or gain due to its modification. Whether...or not an economic value is estimated, the changes - quantitative and qualitative - should be recognized. An examination of several flood plain

  18. 44 CFR 60.5 - Flood plain management criteria for flood-related erosion-prone areas.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plain management criteria for flood-related erosion-prone areas. 60.5 Section 60.5 Emergency Management and Assistance... National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for Flood...

  19. Floods, floodplains, delta plains — A satellite imaging approach

    Science.gov (United States)

    Syvitski, James P. M.; Overeem, Irina; Brakenridge, G. Robert; Hannon, Mark

    2012-08-01

    Thirty-three lowland floodplains and their associated delta plains are characterized with data from three remote sensing systems (AMSR-E, SRTM and MODIS). These data provide new quantitative information to characterize Late Quaternary floodplain landscapes and their penchant for flooding over the last decade. Daily proxy records for discharge since 2002 and for each of the 33 river systems can be derived with novel Advanced Microwave Scanning Radiometer (AMSR-E) methods. A descriptive framework based on analysis of Shuttle Radar Topography Mission (SRTM) data is used to capture the major landscape-scale floodplain elements or zones: 1) container valleys with their long and narrow pathways of largely sediment transit and bypass, 2) floodplain depressions that act as loci for frequent flooding and sediment storage, 3) zones of nodal avulsions common to many continental scale rivers, and often located seaward of container valleys, and 4) coastal floodplains and delta plains that offer both sediment bypass and storage but under the influence of marine processes. The SRTM data allow mapping of smaller-scale architectural elements in unprecedented systematic manner. Floodplain depressions were found to play a major role, which may largely be overlooked in conceptual floodplain models. Lastly, MODIS data (independently and combined with AMSR-E) allows the tracking of flood hydrographs and pathways and sedimentation patterns on a near-daily timescale worldwide. These remote-sensing data show that 85% of the studied major river systems experienced extensive flooding in the last decade. A new quantitative paradigm of floodplain processes, honoring the frequency and extent of floods, can be develop by careful analysis of these new remotely sensed data.

  20. 44 CFR 60.2 - Minimum compliance with flood plain management criteria.

    Science.gov (United States)

    2010-10-01

    ... assure that its comprehensive plan is consistent with the flood plain management objectives of this part... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Minimum compliance with flood plain management criteria. 60.2 Section 60.2 Emergency Management and Assistance FEDERAL...

  1. Flood Plain Topography Affects Establishment Success of Direct-Seeded Bottomland Oaks

    Science.gov (United States)

    Emile S. Gardiner; John D. Hodges; T. Conner Fristoe

    2004-01-01

    Five bottomland oak species were direct seeded along a topographical gradient in a flood plain to determine if environmental factors related to relative position in the flood plain influenced seedling establishment and survival. Two years after installation of the plantation, seedling establishment rates ranged from 12±1.6 (mean ± standard error) percent for overcup...

  2. Metal concentrations in the groundwater in Birjand flood plain, Iran.

    Science.gov (United States)

    Mansouri, Borhan; Salehi, Javad; Etebari, Behrooz; Moghaddam, Hamid Kardan

    2012-07-01

    The objective of the present study was to investigate the concentration of metals (cadmium, lead, chromium, zinc, copper, and iron) were measured in groundwater at 30 sites from the Birjand flood plain of eastern Iran during the November 2010; identify any relationships between metals and pH, total hardness. Metal concentrations in the groundwater samples were decreased in sequence of Zn > Fe > Cu > Cr > Pb > Cd, respectively. The results showed that the overall mean concentrations of Cd, Pb, and Cr were at 0.000, 0.023, and 0.049 mg l(-1), respectively. The mean concentration of Cu, Zn, and Fe were 0.109, 0.192, and 0.174 mg l(-1), respectively. Results also indicated that there were correlations among Cd, Cu, and Zn metals.

  3. Evidence of floods on the Potomac River from anatomical abnormalities in the wood of flood-plain trees

    Science.gov (United States)

    Yanosky, Thomas M.

    1983-01-01

    Ash trees along the Potomac River flood plain near Washington, D.C., were studied to determine changes in wood anatomy related to flood damage, and anomalous growth was compared to flood records for April 15 to August 31, 1930-79. Collectively, anatomical evidence was detected for 33 of the 34 growing-season floods during the study period. Evidence of 12 floods prior to 1930 was also noted, including catastrophic ones in 1889 and 1924. Trees damaged after the transition from earlywood to latewood growth typically formed ' flood rings ' of enlarged vessels within the latewood zone. Trees damaged near the beginning of the growth year developed flood rings within, or contiguous with, the earlywood. Both patterns are assumed to have developed when flood-damaged trees produced a second crop of leaves. Trees damaged by high-magnitude floods developed well formed flood rings along the entire height and around the entire circumference of the stem. Small floods were generally associated wtih diffuse or discontinuous anomalies restricted to stem apices. Frequency of flood rings was positively related to flood magnitude, and time of flood generation during the tree-growth season was estimated from the radial position of anomalous growth relative to annual ring width. Reconstructing tree heights in a year of flood-ring formation gives a minimum stage estimate along local stream reaches. Some trees provided evidence of numerous floods. Those with the greatest number of flood rings grew on frequently flooded surfaces subject to flood-flow velocities of at least 1 m/s, and more typically greater than 2 m/s. Tree size, more than age, was related to flood-ring formation. Trees kept small by frequent flood damage had more flood rings than taller trees of comparable age. (USGS)

  4. Has land subsidence changed the flood hazard potential? A case example from the Kujukuri Plain, Chiba Prefecture, Japan

    Science.gov (United States)

    Chen, H. L.; Ito, Y.; Sawamukai, M.; Su, T.; Tokunaga, T.

    2015-11-01

    Coastal areas are subject to flood hazards because of their topographic features, social development and related human activities. The Kujukuri Plain, Chiba Prefecture, Japan, is located nearby the Tokyo metropolitan area and it faces to the Pacific Ocean. In the Kujukuri Plain, widespread occurrence of land subsidence has been caused by exploitation of groundwater, extraction of natural gas dissolved in brine, and natural consolidation of the Holocene and landfill deposits. The locations of land subsidence include areas near the coast, and it may increase the flood hazard potential. Hence, it is very important to evaluate flood hazard potential by taking into account the temporal change of land elevation caused by land subsidence, and to prepare hazard maps for protecting the surface environment and for developing an appropriate land-use plan. In this study, flood hazard assessments at three different times, i.e., 1970, 2004, and 2013 are implemented by using a flood hazard model based on Multicriteria Decision Analysis with Geographical Information System techniques. The model incorporates six factors: elevation, depression area, river system, ratio of impermeable area, detention ponds, and precipitation. Main data sources used are 10 m resolution topography data, airborne laser scanning data, leveling data, Landsat-TM data, two 1:30 000 scale river watershed maps, and precipitation data from observation stations around the study area and Radar data. The hazard assessment maps for each time are obtained by using an algorithm that combines factors with weighted linear combinations. The assignment of the weight/rank values and their analysis are realized by the application of the Analytic Hierarchy Process method. This study is a preliminary work to investigate flood hazards on the Kujukuri Plain. A flood model will be developed to simulate more detailed change of the flood hazard influenced by land subsidence.

  5. Responses of Carbon Dynamics to Nitrogen Deposition in Typical Freshwater Wetland of Sanjiang Plain

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2014-01-01

    Full Text Available The effects of nitrogen deposition (N-deposition on the carbon dynamics in typical Calamagrostis angustifolia wetland of Sanjiang Plain were studied by a pot-culture experiment during two continuous plant growing seasons. Elevated atmospheric N-deposition caused significant increases in the aboveground net primary production and root biomass; moreover, a preferential partition of carbon to root was also observed. Different soil carbon fractions gained due to elevated N-deposition and their response intensities followed the sequence of labile carbon > dissolved organic carbon > microbial biomass carbon, and the interaction between N-deposition and flooded condition facilitated the release of different carbon fractions. Positive correlations were found between CO2 and CH4 fluxes and liable carbon contents with N-deposition, and flooded condition also tended to facilitate CH4 fluxes and to inhibit the CO2 fluxes with N-deposition. The increases in soil carbon fractions occurring in the nitrogen treatments were significantly correlated with increases in root, aboveground parts, total biomass, and their carbon uptake. Our results suggested that N-deposition could enhance the contents of active carbon fractions in soil system and carbon accumulation in plant of the freshwater wetlands.

  6. Geohazards (floods and landslides) in the Ndop plain, Cameroon volcanic line

    Science.gov (United States)

    Wotchoko, Pierre; Bardintzeff, Jacques-Marie; Itiga, Zénon; Nkouathio, David Guimolaire; Guedjeo, Christian Suh; Ngnoupeck, Gerald; Dongmo, Armand Kagou; Wandji, Pierre

    2016-07-01

    The Ndop Plain, located along the Cameroon Volcanic Line (CVL), is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually) and landslides (occasionally) occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people) tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide) maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered. The hazard maps revealed that 25% of the area is exposed to flood hazard (13% exposed to high flood hazard, 12% to moderate) and 5% of the area is exposed to landslide hazard (2% exposed to high landslide hazard, 3% to moderate). Some mitigation measures for floods (building of artificial levees, raising foundations of buildings and the meticulous regulation of the flood guards at Bamendjing Dam) and landslides (slope terracing, planting of trees, and building retaining walls) are proposed.

  7. Geohazards (floods and landslides in the Ndop plain, Cameroon volcanic line

    Directory of Open Access Journals (Sweden)

    Wotchoko Pierre

    2016-07-01

    Full Text Available The Ndop Plain, located along the Cameroon Volcanic Line (CVL, is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually and landslides (occasionally occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered.

  8. The geochemistry in the Manzanares river flood plain sediments as a way to assess environmental impact; La geoquimica en los sedimentos de la llanura de inundacion del Manzanares como medio para evaluar el impacto ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, P.; Garcia Cortes, A.; Locutura, J.

    2009-07-01

    Flood plains are an important component of drainage systems, as they act like transport channels and stores or sinks for suspended sediment deposited during the floods. A geochemical study in flood plain sediments is a reliable method to reconstruct the evolution of anthropic contamination through time in a basin. As an application of this method, the flood plain of the Manzanares River (Madrid) has been examined, as an example of urban environment. Samples have been collected through the flood plain vertical profile at two different selected sites upstream and downstream the city of Madrid. The samples have been sieved at six sizes of grain in which trace elements have been analysed by ICP-MS and INAA. This study highlights an increase in the contents of contaminant elements in the profile sampled downstream as well as an enrichment of these elements as the sediment is younger. (Author) 19 refs.

  9. Flood risk of natural and embanked landscapes on the Ganges-Brahmaputra tidal delta plain

    Science.gov (United States)

    Auerbach, L. W.; Goodbred, S. L., Jr.; Mondal, D. R.; Wilson, C. A.; Ahmed, K. R.; Roy, K.; Steckler, M. S.; Small, C.; Gilligan, J. M.; Ackerly, B. A.

    2015-02-01

    The Ganges-Brahmaputra river delta, with 170 million people and a vast, low-lying coastal plain, is perceived to be at great risk of increased flooding and submergence from sea-level rise. However, human alteration of the landscape can create similar risks to sea-level rise. Here, we report that islands in southwest Bangladesh, enclosed by embankments in the 1960s, have lost 1.0-1.5 m of elevation, whereas the neighbouring Sundarban mangrove forest has remained comparatively stable. We attribute this elevation loss to interruption of sedimentation inside the embankments, combined with accelerated compaction, removal of forest biomass, and a regionally increased tidal range. One major consequence of this elevation loss occurred in 2009 when the embankments of several large islands failed during Cyclone Aila, leaving large areas of land tidally inundated for up to two years until embankments were repaired. Despite sustained human suffering during this time, the newly reconnected landscape received tens of centimetres of tidally deposited sediment, equivalent to decades’ worth of normal sedimentation. Although many areas still lie well below mean high water and remain at risk of severe flooding, we conclude that elevation recovery may be possible through controlled embankment breaches.

  10. Production and decomposition of forest litter fall on the Apalachicola River flood plain, Florida: Chapter B, Apalachicola River quality assessment

    Science.gov (United States)

    Elder, John F.; Cairns, Duncan J.

    1982-01-01

    Measurements of litter fall (leaves and other particulate organic material) and leaf decomposition were made on the bottom-land hardwood swamp of the Apalachicola River flood plain in 1979-80. Litter fall was collected monthly from nets located in 16 study plots. The plots represented five forest types in the swamp and levee areas of the Apalachicola River flood plain. Forty-three species of trees, vines, and other plants contributed to the total litter fall, but more than 90 percent of the leaf material originated from 12 species. Nonleaf material made up 42 percent of the total litter fall. Average litter fall was determined to be 800 grams per square meter per year, resulting in an annual deposition of 3.6 ? 105 metric tons of organic material in the 454-square-kilometer flood plain. The levee communities have less tree biomass but greater tree diversity than do swamp communities. The levee vegetation, containing less tree biomass, produces slightly more litter fall per unit of ground surface area than does the swamp vegetation. The swamps are dominated by three genera: tupelo (Nyssa), cypress (Taxodium) and ash (Fraxinus). These genera account for more than 50 percent of the total leaf fall in the flood plain, but they are the least productive, on a weight-perbiomass basis, of any of the 12 major leaf producers. Decomposition rates of leaves from five common floodplain tree species were measured using a standard leaf-bag technique. Leaf decomposition was highly species dependent. Tupelo (Nyssa spp.) and sweetgum (Liquidambar styraciflua) leaves decomposed completely in 6 months when flooded by river water. Leaves of baldcypress (Taxodium distichum) and diamond-leaf oak (Quercus laurifolia) were much more resistant. Water hickory (Carya aquatica) leaves showed intermediate decomposition rates. Decomposition of all species was greatly reduced in dry environments. Carbon and biomass loss rates from the leaves were nearly linear over a 6-month period, but nitrogen

  11. A study of farmers' flood perceptions based on the entropy method: an application from Jianghan Plain, China.

    Science.gov (United States)

    Luo, Xiaofeng; Lone, Todd; Jiang, Songying; Li, Rongrong; Berends, Patrick

    2016-07-01

    Using survey data from 280 farmers in Jianghan Plain, China, this paper establishes an evaluation index system for three dimensions of farmers' flood perceptions and then uses the entropy method to estimate their overall flood perception. Farmers' flood perceptions exhibit the following characteristics: (i) their flood-occurrence, flood-prevention, and overall flood perceptions gradually increase with age, whereas their flood-effects perception gradually decreases; (ii) their flood-occurrence and flood-effects perceptions gradually increase with a higher level of education, whereas their flood-prevention perception gradually decreases and their overall flood perception shows nonlinear change; (iii) flood-occurrence, flood-effects, and overall flood perceptions are higher among farmers who serve in public offices than among those who do not do so; (iv) the flood-occurrence, flood-effects, and overall flood perceptions of farmers who work off-farm are higher than those of farmers who work solely on-farm, contrary to the flood-prevention perception; and (v) the flood-effects and flood-prevention perceptions of male farmers are lower than those of female farmers, but the flood-occurrence and overall flood perceptions of male farmers are higher than those of female farmers.

  12. Preliminary assessment of metal toxicity in the middle Tisza river (Hungary) flood plain

    Energy Technology Data Exchange (ETDEWEB)

    Black, M.C.; Williams, P.L. [Dept. of Environmental Health Science, Univ. of Georgia, Athens, GA (United States)

    2001-07-01

    Cyanide and heavy metals were accidentally released from a mine waste lagoon in Romania into tributaries ultimately draining into the Tisza River. Within two months of the cyanide accident two subsequent heavy metal waste spills further contaminated the Tisza River, followed by severe spring flooding, which potentially spread the contamination to soils adjacent to the river. Flood plain soils and shoreline sediments were sampled from two locations on the middle Tisza River and a reference site to conduct a preliminary assessment of metal content and toxicity. Ten-day sediment toxicity tests were conducted with the amphipod, Hyalella azteca and 24 h soil toxicity tests were conducted with the nematode (Caenorhabditis elegans). High concentrations of cadmium, copper, zinc, lead and arsenic were detected in soil and sediment samples. However, no mortality was observed in Hyalella exposed to Tisza River sediments and only up to 27% mortality of C. elegans was observed in flood plain soils. Low mortalities are attributed to reduced metal bioavailability caused by high soil cation exchange capacities and possible interactions with sediment organic matter or sulfides. Future studies should focus on factors that alter metal bioavailability and their relationship to potential toxicity of organisms exposed to Tisza River sediments and flood plain soils. (orig.)

  13. Production and decomposition of forest litter fall on the Apalachicola River flood plain, Florida

    Science.gov (United States)

    Elder, J.F.; Cairns, D.J.

    1982-01-01

    Measurements of litter fall (leaves and other particulate organic material) and leaf decomposition were made on the Apalachicola River flood plain in 1979-80. Litter fall was collected monthly in five different forest types in swamp and levee areas. Leaves from 42 species of trees and other plants accounted for 58 percent of total litter fall. The remaining 42 percent was nonleaf material. Average litter fall was 800 grams per square meter per year in the flood plain. Tupelo (Nyssa), baldcypress (Taxodium), and ash (Fraxinus), all swamp-adapted trees, produce over 50 percent of the leaf fall. Common levee species such as sweetgum (Liquidambar styraciflua) and diamond-leaf oak (Quercus laurifolia) are also major contributors to total flood-plain litter fall. Annual flooding of the river provides an important mechanism for mobilization of the litter-fall products. Leaf decomposition rates were greatly reduced in dry environments. Carbon loss was nearly linear over a 6-month period, but nitrogen and phosphorus loss was exponential and nearly complete within 1 month. (USGS)

  14. A participatory approach of flood vulnerability assessment in the Banat Plain, Romania

    Science.gov (United States)

    Balteanu, Dan; Costache, Andra; Sima, Mihaela; Dumitrascu, Monica; Dragota, Carmen; Grigorescu, Ines

    2014-05-01

    The Banat Plain (western Romania) is a low, alluvial plain affected by neotectonic subsidence movements, being a critical region in terms of exposure to floods. The latest extreme event was the historic floods occcured in the spring of 2005, which caused significant economic damage in several rural communities. The response to 2005 floods has highlighted a number of weaknesses in the management of hazards, such as the deficiencies of the early warning system, people awareness or the inefficiency of some mitigation measures, besides the past structural measures which are obsolete. For a better understanding of the local context of vulnerability and communities resilience to floods, the quantitative assessment of human vulnerability to floods was supplemented with a participatory research, in which there were involved five rural settlements from the Banat Plain (comprising 15 villages and a population of over 12,000 inhabitants). Thus, in the spring of 2013, a questionnaire-based survey was conducted in approx. 100 households of the affected communities and structured interviews were held with local authorities, in the framework of VULMIN project, funded by the Ministry of National Education. The questionnaire was designed based on a pilot survey conducted in 2005, several months after the flood, and was focused on two major issues: a) perception of the local context of vulnerability to environmental change and extreme events; b) perception of human vulnerability to floods (personal experience, post-disaster rehabilitation, awareness, worrying and opinion on the measures aimed to prevent and mitigate the effects of flooding). The results were correlated with a number of specific variables of the households included in the sample, such as: household structure; income source; income level; location of the dwelling in relation to floodplains. In this way, we were able to draw general conclusions about the way in which local people perceive the extreme events, such as

  15. 44 CFR 60.3 - Flood plain management criteria for flood-prone areas.

    Science.gov (United States)

    2010-10-01

    ... without causing collapse, displacement, or other structural damage to the elevated portion of the building...) The elevated portion of the building and supporting foundation system shall not be subject to collapse... proposed building sites will be reasonably safe from flooding. If a proposed building site is in a flood...

  16. Flood-induced transport of PAHs from streambed coal tar deposits.

    Science.gov (United States)

    Vulava, Vijay M; Vaughn, D Syreeta; McKay, Larry D; Driese, Steven G; Cooper, Lee W; Menn, Fu-Min; Levine, Norman S; Sayler, Gary S

    2017-01-01

    We assessed whether coal tar present in contaminated streambed sediments can be mobilized by flood events and be re-deposited in an adjacent floodplain. The study was conducted within a contaminated urban stream where coal tar wastes were released into a 4-km reach from a coke plant in Chattanooga, Tennessee, USA. Sediments containing visible amounts of coal tar were dredged from the streambed in 1997-98 and 2007 as part of a cleanup effort. However, post-dredging sampling indicated that very high concentrations of polycyclic aromatic hydrocarbons (PAHs) remained in streambed sediments. Sampling of sediments in the floodplain at two sites downstream of the coke plant indicated that high concentrations of PAHs were also present in the floodplain, even though no coal tar was observed in the samples. Age-dating of the floodplain sediments using (137)Cs indicated that peak PAH concentrations were contemporary with coke plant operations. While there was little or any direct contamination of the floodplain sediments by coal tar, sediment contamination was likely a result of deposition of suspended streambed sediments containing sorbed PAHs. A flood model developed to delineate the extent of flooding in various flood recurrence scenarios confirmed the potential for contaminated streambed sediments to be transported into the adjacent floodplain. It was hypothesized that coal tar, which was visibly "sticky" during dredging-based stream cleanup, may act as a binding agent for streambed sediments, decreasing mobility and transport in the stream. Therefore, coal tar is likely to remain a persistent contaminant source for downstream reaches of the stream and the adjacent floodplain during flood events. This study also showed that even after excavation of tar-rich streambed sediments, PAH contaminated non-tarry sediments may be a source of flood-related contamination in the adjacent flood plain. A conceptual framework was developed to delineate specific mechanisms that can

  17. Investigating organic micropollutants in a peri-urban flood plain aquifer

    OpenAIRE

    Manamsa, Katya; Lapworth, Dan; Stuart, Marianne

    2011-01-01

    This poster describes a pilot study to develop the sampling methodology required to investigate the occurrence and distribution of “emerging organic contaminants” in groundwater in an area of anticipated contamination. The study site was the BGS Oxford Observatory on the Port Meadow, within a peri-urban setting, including an area of ancient grassland on the gravels of the flood plain of the River Thames to the northwest of Oxford. Groundwater levels suggest that the regional groundwater flow ...

  18. Influence of hydrological, biogeochemical and temperature transients on subsurface carbon fluxes in a flood plain environment

    Energy Technology Data Exchange (ETDEWEB)

    Arora, Bhavna; Spycher, Nicolas F.; Steefel, Carl I.; Molins, Sergi; Bill, Markus; Conrad, Mark E.; Dong, Wenming; Faybishenko, Boris; Tokunaga, Tetsu K.; Wan, Jiamin; Williams, Kenneth H.; Yabusaki, Steven B.

    2016-02-01

    Flood plains play a potentially important role in the global carbon cycle. The accumulation of organic matter in flood plains often induces the formation of chemically reduced groundwater and sediments along riverbanks. In this study, our objective is to evaluate the cumulative impact of such reduced zones, water table fluctuations, and temperature gradients on subsurface carbon fluxes in a flood plain at Rifle, Colorado located along the Colorado River. 2-D coupled variably-saturated, non-isothermal flow and biogeochemical reactive transport modeling was applied to improve our understanding of the abiotic and microbially mediated reactions controlling carbon dynamics at the Rifle site. Model simulations considering only abiotic reactions (thus ignoring microbial reactions) underestimated CO2 partial pressures observed in the unsaturated zone and severely underestimated inorganic (and overestimated organic) carbon fluxes to the river compared to simulations with biotic pathways. Both model simulations and field observations highlighted the need to include microbial contributions from chemolithoautotrophic processes (e.g., Fe?2 and S-2 oxidation) to match locally-observed high CO2 concentrations above reduced zones. Observed seasonal variations in CO2 concentrations in the unsaturated zone could not be reproduced without incorporating temperature gradients in the simulations. Incorporating temperature fluctuations resulted in an increase in the annual groundwater carbon fluxes to the river by 170 % to 3.3 g m-2 d-1, while including water table variations resulted in an overall decrease in the simulated fluxes. We conclude that spatial microbial and redox zonation as well as temporal fluctuations of temperature and water table depth contribute significantly to subsurface carbon fluxes in flood plains and need to be represented appropriately in model simulations.

  19. Wetland hydrology and tree distribution of the Apalachicola River flood plain, Florida

    Science.gov (United States)

    Leitman, Helen M.; Sohm, James E.; Franklin, Marvin A.

    1984-01-01

    The Apalachicola River in northwest Florida is part of a three-State drainage basin encompassing 50,800 km 2 in Alabama, Georgia, and Florida. The river is formed by the confluence of the Chattahoochee and Flint Rivers at Jim Woodruff Dam from which it flows 171 km to Apalachicola Bay in the Gulf of Mexico. Its average annual discharge at Chattahoochee, Fla., is 690 m3/s (1958-80) with annual high flows averaging nearly 3,000 m3/s. Its flood plain supports 450 km 2 of bottom-land hardwood and tupelo-cypress forests. The Apalachicola River Quality Assessment focuses on the hydrology and productivity of the flood-plain forest. The purpose of this part of the assessment is to address river and flood-plain hydrology, flood-plain tree species and forest types, and water and tree relations. Seasonal stage fluctuations in the upper river are three times greater than in the lower river. Analysis of long-term streamflow record revealed that 1958-79 average annual and monthly flows and flow durations were significantly greater than those of 1929-57, probably because of climatic changes. However, stage durations for the later period were equal to or less than those of the earlier period. Height of natural riverbank levees and the size and distribution of breaks in the levees have a major controlling effect on flood-plain hydrology. Thirty-two kilometers upstream of the bay, a flood-plain stream called the Brothers River was commonly under tidal influence during times of low flow in the 1980 water year. At the same distance upstream of the bay, the Apalachicola River was not under tidal influence during the 1980 water year. Of the 47 species of trees sampled, the five most common were wet-site species constituting 62 percent of the total basal area. In order of abundance, they were water tupelo, Ogeechee tupelo, baldcypress, Carolina ash, and swamp tupelo. Other common species were sweetgum, overcup oak, planertree, green ash, water hickory, sugarberry, and diamond-leaf oak

  20. Glacial conditioning of stream position and flooding in the braid plain of the Exit Glacier foreland, Alaska

    Science.gov (United States)

    Curran, Janet H.; Loso, Michael G.; Williams, Haley B.

    2017-09-01

    Flow spilling out of an active braid plain often signals the onset of channel migration or avulsion to previously occupied areas. In a recently deglaciated environment, distinguishing between shifts in active braid plain location, considered reversible by fluvial processes at short timescales, and more permanent glacier-conditioned changes in stream position can be critical to understanding flood hazards. Between 2009 and 2014, increased spilling from the Exit Creek braid plain in Kenai Fjords National Park, Alaska, repeatedly overtopped the only access road to the popular Exit Glacier visitor facilities and trails. To understand the likely cause of road flooding, we consider recent processes and the interplay between glacier and fluvial system dynamics since the maximum advance of the Little Ice Age, around 1815. Patterns of temperature and precipitation, the variables that drive high streamflow via snowmelt, glacier meltwater runoff, and rainfall, could not fully explain the timing of road floods. Comparison of high-resolution topographic data between 2008 and 2012 showed a strong pattern of braid plain aggradation along 3 km of glacier foreland, not unexpected at the base of mountainous glaciers and likely an impetus for channel migration. Historically, a dynamic zone follows the retreating glacier in which channel positions shift rapidly in response to changes in the glacier margin and fresh morainal deposits. This period of paraglacial adjustment lasts one to several decades at Exit Glacier. Subsequently, as moraine breaches consolidate and lock the channel into position, and as the stream regains the lower-elevation valley center, upper-elevation surfaces are abandoned as terraces inaccessible by fluvial processes for timescales of decades to centuries. Where not constrained by these terraces and moraines, the channel is free to migrate, which in this aggradational setting generates an alluvial fan at the breach of the final prominent moraine. The position of

  1. Taenia spp. infections in wildlife in the Bangweulu and Kafue flood plains ecosystems of Zambia.

    Science.gov (United States)

    Muma, J B; Gabriël, S; Munyeme, M; Munang'andu, H M; Victor, B; Dorny, P; Nalubamba, K S; Siamudaala, V; Mwape, K E

    2014-09-15

    Taenia spp. have an indirect life cycle, cycling between a definitive and an intermediate host with zoonotic species causing public health problems in many developing countries. During the course of 2 separate surveys in Zambia (2004 and 2009), the presence of Taenia larval stages (cysticerci) was examined in Kafue lechwe (Kobus leche kafuensis), Black lechwe (Kobus leche smithermani) and other wildlife species from the Kafue and Bangweulu flood plains. Examinations involved post-mortem inspection and serum specific antigen detection. The recovered cysts from seven carcasses were characterised using PCR and DNA sequence analysis. The overall proportion of infection in wildlife on post-mortem examination was 19.0% (95% CI: 9.1-29.0%). The proportion of infected wildlife based on post-mortem examinations in the Kafue flood plains was estimated at 28.6% (95% CI: 13.3-43.9%), while the seroprevalence was estimated at 25.0% (95% CI: 2.9-47.1%). The seroprevalence for cattle in the Kafue flood plains was estimated at 61.5% (95% CI: 42.0-81.0%) while that of Kafue lechwe in the same ecosystem was estimated at 66.6% (95% CI: 45.6-85.7%). Infection rates were higher in Kafue lechwe than in Black lechwe suggesting differences in the exposure patterns. The sequencing results indicated that none of the recovered cysts were either Taenia solium or Taenia saginata. We therefore conclude they most likely belong to a less studied (wildlife) Taenia species that requires further characterisation.

  2. 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.

    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 mon

  3. Modeling of the solid-solution partitioning of heavy metals and arsenic in embanked flood plain soils of the rivers Rhine and Meuse

    NARCIS (Netherlands)

    Schröder, T.J.; Hiemstra, T.; Vink, J.P.M.

    2005-01-01

    The aim of this study is to predict the solid-solution partitioning of heavy metals in river flood plain soils. We compared mechanistic geochemical modeling with a statistical approach. To characterize the heavy metal contamination of embanked river flood plain soils in The Netherlands, we collected

  4. Modeling of the solid-solution partitioning of heavy metals and arsenic in embanked flood plain soils of the rivers Rhine and Meuse

    NARCIS (Netherlands)

    Schröder, T.J.; Hiemstra, T.; Vink, J.P.M.

    2005-01-01

    The aim of this study is to predict the solid-solution partitioning of heavy metals in river flood plain soils. We compared mechanistic geochemical modeling with a statistical approach. To characterize the heavy metal contamination of embanked river flood plain soils in The Netherlands, we collected

  5. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Estimated thickness of ejecta deposits compared to to crater rim heights. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    The area of the continuous ejecta deposits on mercury was calculated to vary from 2.24 to 0.64 times the crater's area for those of diameter 40 km to 300 km. Because crater boundaries on the geologic map include the detectable continuous ejecta blanket, plains exterior to these deposits must consist of farther-flung ejecta (of that or other craters), or volcanic deposits flooding the intervening areas. Ejecta models are explored.

  6. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Estimated thickness of ejecta deposits compared to to crater rim heights. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    The area of the continuous ejecta deposits on mercury was calculated to vary from 2.24 to 0.64 times the crater's area for those of diameter 40 km to 300 km. Because crater boundaries on the geologic map include the detectable continuous ejecta blanket, plains exterior to these deposits must consist of farther-flung ejecta (of that or other craters), or volcanic deposits flooding the intervening areas. Ejecta models are explored.

  7. Ice jam-caused fluvial gullies and scour holes on northern river flood plains

    Science.gov (United States)

    Smith, Derald G.; Pearce, Cheryl M.

    2002-01-01

    Two anomalous fluvial landforms, gullies and scour holes, eroded into flood plains bordering meandering and braiding river channels have not been previously reported. We observed these features along the Milk River in southern Alberta, Canada, and northern Montana, USA, which has a history of frequent (50% probability of recurrence) and high-magnitude (12% probability of recurrence greater than bankfull) ice jam floods. Gullies have palmate and narrow linear shapes with open-ends downvalley and measure up to 208 m long×139 m wide×3.5 m deep (below bankfull). Channel ice jams reroute river water across meander lobes and cause headward gully erosion where flow returns to the main channel. Erosion of the most recent gully was observed during the record 1996 ice breakup flood and ice jams. Scour holes (bowl-shaped, closed depressions), eroded by water vortices beneath and between grounded ice jam blocks, measure up to 91 m long×22 m wide×4.5 m deep. Ice jam-caused gullies may be precursors to the formation of U-shaped oxbow lakes and multiple channels, common in many northern rivers.

  8. Flood risk mitigation and anthropogenic modifications of a coastal plain in southern Italy: combined effects over the past 150 years

    Directory of Open Access Journals (Sweden)

    O. Petrucci

    2007-06-01

    Full Text Available A study of the effects of human modification of a coastal plain mainly involving land reclamation and flood protection is proposed. The approach involves historical, geomorphological and hydrological data as a whole, taking into account the equilibrium of rivers, plains and coastal areas.

    The test area, a telling example of profound economic and social transformation of a coastal plain, is the Piana di Sibari (Calabria, southern Italy, subject to major human modifications over the last 150 years. The study area, at most 300 m a.s.l., is 450 km2 wide and comprises 24 hydrographic basins.

    The approach is based on the creation and analysis of four databases: 1 a historical series of geo-coded flood damage (DAMAGES database, concerning damaging floods which occurred over the past few centuries in the study area; 2 a geocoded series of protection works for land reclamation, protection from floods and improvement of soil stability in steep areas (WORKS database, gathered from the archives of the agencies that carried out the works, organized in a GIS-format; 3 a historical series of maximum flood discharges and extreme rainy events (HYMAX database aimed at defining the trends of occurrence and the intensity of flooding; 4 a coastal line position and migration over time (COASTAL database, created using mainly literature data based on discontinuous data such as historical maps and images.

    The work describes the complex succession of floods, protection and reclamation works, human transformation of the plain and major land use changes over the last two centuries in the test area. The new characteristics of the plain and its modifications, including major engineering works, land-use transformation and urbanisation, are illustrated. The damaging floods of the last 200 years, the modifications of runoff and flooding due to works built over the basins, hydrological data and the records concerning coastal

  9. Tracking the deposition of sediments from the Great Mississippi Flood of 2011

    Science.gov (United States)

    Khan, N. S.; McKee, K. L.; Horton, B. P.; Varvaeke, W.; Dura, T.; Jerolmack, D. J.

    2011-12-01

    The marshes of coastal Louisiana are disappearing at a rapid rate due to both natural and anthropogenic processes. Maintenance of soil elevations relative to water levels is key to marsh sustainability, but leveeing of the Mississippi River prevents overbank flooding and direct delivery of sediment to counterbalance rapid rates of subsidence in the deltaic plain. Episodic sediment deposition may occur during storms and hurricanes or extreme flood events, contributing to marsh accretion, but their relative importance to marsh maintenance is unclear. A better understanding of routing and deposition of sediments and their role in the marsh-building dynamics of coastal Louisiana would help clarify these issues and aid restoration planning. The Great Mississippi River Flood of 2011 caused sustained high discharge, producing a narrow jet that penetrated far into the Gulf of Mexico, and prompted the opening of the Morganza spillway, which generated a wide, diffuse plume that inundated vast areas of land and was trapped within coastal currents. These events provided a unique opportunity to test a new theoretical model of coastal sediment dynamics that predicts greater sedimentation over a broader area from the smaller Atchafalaya channel in comparison to the focused plume emanating from the larger Mississippi River channel. Here, we report how the flood contributed to marsh sedimentation, which is part of a larger effort to connect offshore sediment dynamics to sediment delivery and soil accretion within wetlands. A helicopter survey of 45 sites was conducted across the Mississippi (Bird's Foot) Delta, Barataria, Terrebonne, and Atchafalaya basins (350 km of coastline) to measure sediment accumulation and determine its provenance. At each site, new flood sediment deposits were distinguished from pre-flood sediment and sampled separately for organic matter content, bulk density, grain-size and diatom analysis. Comparison of grain-size distribution and diatom assemblages of

  10. Differentiation of debris-flow and flash-flood deposits: implications for paleoflood investigations

    Science.gov (United States)

    Waythomas, Christopher F.; Jarrett, Robert D.; ,

    1993-01-01

    Debris flows and flash floods are common geomorphic processes in the Colorado Rocky Mountain Front Range and foothills. Usually, debris flows and flash floods are associated with excess summer rainfall or snowmelt, in areas were unconsolidated surficial deposits are relatively thick and slopes are steep. In the Front Range and foothills, flash flooding is limited to areas below about 2300m whereas, debris flow activity is common throughout the foothill and alpine zones and is not necessarily elevation limited. Because flash floods and debris flows transport large quantities of bouldery sediment, the resulting deposits appear somewhat similar even though such deposits were produced by different processes. Discharge estimates based on debris-flow deposits interpreted as flash-flood deposits have large errors because techniques for discharge retrodiction were developed for water floods with negligible sediment concentrations. Criteria for differentiating between debris-flow and flash-flood deposits are most useful for deposits that are fresh and well-exposed. However, with the passage of time, both debris-flow and flash-flood deposits become modified by the combined effects of weathering, colluviation, changes in surface morphology, and in some instances removal of interstitial sediment. As a result, some of the physical characteristics of the deposits become more alike. Criteria especially applicable to older deposits are needed. We differentiate flash-flood from debris-flow and other deposits using clast fabric measurements and other morphologic and sedimentologic techniques (e.g., deposit morphology, clast lithology, particle size and shape, geomorphic setting).

  11. Impact of sedimentation in the Dommel flood plain on heavy metal availability and bioaccumulation in flora and fauna

    NARCIS (Netherlands)

    Vink, J.; Klaver, G.; Joziasse, J.

    2007-01-01

    This report describes the application of the BioChem-DSS, being developed in the EU KP6-programme AquaTerra, BASIN R3 work package, with the aim to assist in the definition and improvement of management options for the Meuse region. A case study was carried out in a flood plain site of the river Dom

  12. Extreme flood events and climate change around 3500 aBP in the Central Plains of China

    Institute of Scientific and Technical Information of China (English)

    XIA; Zhengkai; WANG; Zanhong

    2004-01-01

    The Xinzhai Period (3550-3400 aBP) belongs to Late Neolithic Culture, which bridges the Longshan Culture and the Xia Culture in the Central Plains of China. By studying the living environment of ancient human beings at the Xinzhai site, Henan Province, this paper presents the discovery of extreme floods which threatened and destroyed the living environment of the ancient human beings during the Xinzhai Period. Pollen analysis and carbon-oxygen isotope measurement suggest that the climate was warm and wet during the Xinzhai Period, in contrast to the warm and arid climate during the Longshan Culture Period. The frequent flood events were the response of abrupt climate change during the Xinzhai Period. The conclusions drawn from this study not only help better understand the environmental change in the Central Plains of China around 3500 aBP, but also provide important clues to the environmental background for the origin of Chinese civilization.

  13. Regional stratigraphy and subsurface geology of Cenozoic deposits, Gulf Coastal Plain, south-central United States

    Science.gov (United States)

    Hosman, R.L.

    1991-01-01

    The Gulf Coast Regional Aquifer-System Analysis includes all major aquifer systems in Cenozoic deposits in the Gulf Coastal Plain in the States of Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, Texas, and small areas in Alabama and Florida (western panhandle area), an area of about 290,000 square miles. The Gulf Coast geosyncline and the Mississippi embayment were the major depocenters for the Tertiary and Quaternary deposits that form the framework for the aquifer systems.

  14. Sele coastal plain flood risk due to wave storm and river flow interaction

    Science.gov (United States)

    Benassai, Guido; Aucelli, Pietro; Di Paola, Gianluigi; Della Morte, Renata; Cozzolino, Luca; Rizzo, Angela

    2016-04-01

    Wind waves, elevated water levels and river discharge can cause flooding in low-lying coastal areas, where the water level is the interaction between wave storm elevated water levels and river flow interaction. The factors driving the potential flood risk include weather conditions, river water stage and storm surge. These data are required to obtain inputs to run the hydrological model used to evaluate the water surface level during ordinary and extreme events regarding both the fluvial overflow and storm surge at the river mouth. In this paper we studied the interaction between the sea level variation and the river hydraulics in order to assess the location of the river floods in the Sele coastal plain. The wave data were acquired from the wave buoy of Ponza, while the water level data needed to assess the sea level variation were recorded by the tide gauge of Salerno. The water stages, river discharges and rating curves for Sele river were provided by Italian Hydrographic Service (Servizio Idrografico e Mareografico Nazionale, SIMN).We used the dataset of Albanella station (40°29'34.30"N, 15°00'44.30"E), located around 7 km from the river mouth. The extreme river discharges were evaluated through the Weibull equation, which were associated with their return period (TR). The steady state river water levels were evaluated through HEC-RAS 4.0 model, developed by Hydrologic Engineering Center (HEC) of the United States Army Corps of Engineers Hydrologic Engineering Center (USACE,2006). It is a well-known 1D model that computes water surface elevation (WSE) and velocity at discrete cross-sections by solving continuity, energy and flow resistance (e.g., Manning) equation. Data requirements for HEC-RAS include topographic information in the form of a series of cross-sections, friction parameter in the form of Manning's n values across each cross-section, and flow data including flow rates, flow change locations, and boundary conditions. For a steady state sub

  15. Representativeness of soil samples collected to assess mining-related contamination of flood plains in southeast Kansas

    Science.gov (United States)

    Juracek, Kyle E.

    2015-01-01

    Historical lead and zinc mining in the Tri-State Mining District (TSMD), located in parts of southeast Kansas, southwest Missouri, and northeast Oklahoma, has resulted in a substantial ongoing input of lead and zinc to the environment (Juracek, 2006; Juracek and Becker, 2009). In response to concern about the mining-related contamination, southeast Cherokee County, Kansas, was listed on the U.S. Environmental Protection Agency’s (USEPA) National Priority List as a Superfund hazardous waste site (fig. 1). To provide some of the information needed to support remediation efforts in the Cherokee County Superfund site, a study was begun in 2009 by the U.S. Geological Survey (USGS) that was requested and funded by USEPA. As part of the study, surficial-soil sampling was used to investigate the extent and magnitude of mining-related lead and zinc contamination in the flood plains of the Spring River and several tributaries within the Superfund site. In mining-affected areas, flood-plain soils had lead and zinc concentrations that far exceeded background levels as well as probable-effects guidelines for toxic aquatic biological effects (Juracek, 2013). Lead- and zinc-contaminated flood plains are a concern, in part, because they represent a long-term source of contamination to the fluvial environment.

  16. The economic importance of products extracted from Amazonian flood plain forests.

    Science.gov (United States)

    Gram, S; Kvist, L P; Cáseres, A

    2001-09-01

    Rural people in the Peruvian Amazon practice agriculture and extract a wide range of products from natural forests, rivers and lakes. Their diversified livelihood system includes fish, game, and plant products. In 2 flood-plain villages, data for one year have been collected to compare the economy of local agriculture with the economy of extracted forest products for subsistence as well as for commerce. The study includes both fauna (game and fish) and flora (timber as well as nontimber). The results show that extracted forest products for subsistence, especially fish, are a main factor in the local economy. The daily net income from extraction activities exceeds both income from cultivation and the normal daily wages for unskilled workers, emphasizing the need for thorough socioeconomic investigations before any alternative land-use option is implemented. The average value per ha of natural forest used for extraction is in the order of USD 13 yr-1, and the average extraction area is 113 ha household-1. When yield from agriculture is included in the calculations, the total per ha value of current extraction and agricultural activities increases to USD 21 yr-1.

  17. Holocene climatic fluctuations from Lower Brahmaputra flood plain of Assam, northeast India

    Indian Academy of Sciences (India)

    Swati Dixit; S K Bera

    2012-02-01

    Pollen analysis of a 3.2-m deep sedimentary profile cored from the Dabaka Swamp, Nagaon District, Lower Brahmaputra flood plain, Assam has revealed persistent fluvial activity during 14,120–12,700 cal years BP which may be attributed to the paucity of pollen and spores with encounterance of fluvial marker taxa like Ludwigia octavalvis and Botryococcus. Later, fluvial activity was succeeded by the tropical tree savanna under cool and dry climate between 12,700 and 11,600 cal years BP corresponding to that of global Younger Dryas. Between 11,600 and 8310 cal years BP, relatively less cool and dry climate prevailed with inception of tropical mixed deciduous taxa like Shorea robusta and Lagerstroemia parviflora. This phase is further followed by a fluvial activity between 8310 and 7100 cal years BP as evidenced by trace values of pollen and spores. Fluvial activity was further succeeded by enrichment of tropical mixed deciduous forest under warm and humid climatic regime between 7100 and 1550 cal years BP which is well-matched with the peak period of the Holocene climatic optimum. However, during 1550–768 cal years BP, final settlement of tropical mixed deciduous forest occurred under increased warm and humid climate followed by deterioration in tropical mixed deciduous forest under warm and relatively dry climatic regime since 768 cal years BP onwards due to acceleration in human settlement as evidenced by Cerealia. Increase in Melastoma, Ziziphus and Areca catechu imply forest clearance at this phase. The occurrence of degraded pollen-spore along with adequate fungal elements especially, Xylaria, Nigrospora and Microthyriaceous fruiting body is suggestive of aerobic microbial digenesis of rich organic debris during sedimentation.

  18. Effects of flooding and drought on water quality in Gulf Coastal Plain streams in Georgia.

    Science.gov (United States)

    Golladay, Stephen W; Battle, Juliann

    2002-01-01

    Since 1994, water-quality constituents have been measured monthly in three adjacent Coastal Plain watersheds in southwestern Georgia. During 1994, rainfall was 650 mm above annual average and the highest flows on record were observed. From November 1998 through November 2000, 19 months had below average rainfall. Lowest flows on record were observed during the summer of 2000. The watersheds are human-dominated with row-crop agriculture and managed forestlands being the major land uses. However, one watershed (Chickasawhatchee Creek) had 10 to 13% less agriculture and greater wetland area, especially along the stream. Suspended particles, dissolved organic carbon, NH4-N, and soluble reactive phosphorus concentrations were greater during wet and flood periods compared with dry and drought periods for each stream. Regional hydrologic conditions had little effect on NO3-N or dissolved inorganic carbon. Chickasawhatchee Creek had significantly lower suspended sediment and NO3-N concentrations and greater organic and inorganic carbon concentrations, reflecting greater wetland area and stronger connection to a regional aquifer system. Even though substantial human land use occurred within all watersheds, water quality was generally good and can be attributed to low stream drainage density and relatively intact floodplain forests. Low drainage density minimizes surface run-off into streams. Floodplain forests reduce nonpoint-source pollutants through biological and physical absorption. In addition to preserving water quality, floodplain forests provide important ecological functions through the export of nutrients and organic carbon to streams. Extreme low flows may be disruptive to aquatic life due to both the lack of water and to the scarcity of biologically important materials originating from floodplain forests.

  19. Flood Insurance Rate Maps and Base Flood Elevations, FIRM, DFIRM, BFE, flood plains, Published in 2008, 1:24000 (1in=2000ft) scale, Box Elder County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Flood Insurance Rate Maps and Base Flood Elevations, FIRM, DFIRM, BFE dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other...

  20. Flood Zones, Floodway, 100 year flood plain,, Published in 2014, 1:4800 (1in=400ft) scale, GIS.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Flood Zones dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from Other information as of 2014. It is described as 'Floodway, 100...

  1. An analysis on the relationship between land subsidence and floods at the Kujukuri Plain in Chiba Prefecture, Japan

    Science.gov (United States)

    Ito, Y.; Chen, H.; Sawamukai, M.; Su, T.; Tokunaga, T.

    2015-11-01

    Surface environments at the Kujukuri Plain in Chiba Prefecture, Japan, in 1970, 2004, and 2013, were analyzed and compared to discuss the possible impact of land subsidence on the occurrence of floods. The study area has been suffered from land subsidence due to ground deformation from paleo-earthquakes, tectonic activities, and human-induced subsidence by groundwater exploitation. Meteorological data, geomorphological data including DEM obtained from the airborne laser scanning (1-m spatial resolution), leveling data, and the result of our assessment map (Chen et al., 2015) were used in this study. Clear relationship between floods and land subsidence was not recognized, while geomorphological setting, urbanization, and change of precipitation pattern were found to contribute to the floods. The flood prone-area is distributed on the characteristic geomorphological setting such as floodplain and back swamp. It was revealed that the urban area has been expanded on these geomorphological setting in recent years. The frequency of hourly precipitation was also shown to be increased in the past ca. 40 years, and this could induce rapid freshet and overflow of small- and medium-sized rivers and sewerage lines. The distribution of depression areas was increased from 2004 to 2013. This change could be associated with the ground deformation after the Tohoku earthquake (Mw = 9.0) in 2011.

  2. Simulation of nitrogen deposition in the North China Plain by the FRAME model

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2011-08-01

    Full Text Available Simulation of atmospheric nitrogen (N deposition in the North China Plain (NCP at high resolution, 5 × 5 km2, was conducted for the first time by the Fine Resolution Atmospheric Multi-pollutant Exchange (FRAME model. The total N deposition budget was 1481 Gg in this region, with 77 % from reduced N and 23 % from oxidized N, and the annual deposition rate (47 kg ha−1 was much higher than previously reported values for other parts of the world such as the UK (13 kg ha−1, Poland (7.3 kg ha−1 and EU27 (8.6 kg ha−1. The exported N budget (1981 Gg was much higher than the imported N budget (584 Gg, suggesting that the NCP is an important net emission source of N pollutants. Seven provinces in the region contributed N deposition budgets that were proportional to their area ratios. The calculated spatial distributions of N deposition displayed high rates of reduced N deposition in the south and of oxidized N deposition in the eastern part. The N deposition exceeded an upper limit of 30 kg N ha−1 for natural ecosystems over more than 90 % of the region, resulting in terrestrial ecosystem deterioration, impaired air quality and coastal eutrophication not only in the NCP itself but also in surrounding areas including the Bohai Sea and the Yellow Sea.

  3. Assessment of bioavailable metals in the sediments of Yamuna flood plain using two different single extraction procedures

    Directory of Open Access Journals (Sweden)

    Sudesh Chaudhary

    2016-01-01

    Full Text Available Though flood plains are considered as most fertile areas across the world but they have come under severe stress due to the flow of untreated domestic and industrial effluents and therefore, needed attention for its characterisation and subsequent treatment plans. The sediment samples, collected at 0–15, 15–35 and 30–60 cm depth levels during pre and post monsoon season from east and west sides of the river Yamuna around the national capital region of Delhi, were assessed for bioavailability of lead (Pb, zinc (Zn and nickel (Ni using Ethylene Diamine Tetra Acetic Acid (EDTA and acetic acid. The average concentrations of Zn (25 ± 6 mg kg−1 and Pb (33 ± 6 mg kg−1 leached in EDTA were higher than that of in acetic acid (Zn: 22 ± 6 mg kg−1; Pb: 24 ± 5 mg kg−1 whereas Ni (24 ± 6 mg kg−1 leached more in acetic acid compared to EDTA (Ni: 21 ± 4 mg kg−1. The bioavailable concentrations of metals were comparable among 0–15 and 15–35 cm depth samples but decreased in 35–60 cm depth samples. The post monsoon samples contained lower amounts of total metals in comparison to pre-monsoon samples, an indication of washout/dilution effects of flood/high water flow during monsoon season. The percentages of metals, with reference to their respective total concentrations, in the flood plain sediments as extracted by EDTA were in the range of 14–47% for Pb, 17–54% for Zn, and 15–39% for Ni. The Zn, Ni and Pb were soluble in acetic acid in the range of 12–39%, 16.7–36.5% and 14–36%, respectively. The chemical nature of extracting agent affected the metal leaching. Acetic acid, a weak acid, extracted the metals that were present in exchangeable fraction and easily movable whereas EDTA, hexa-dentate complexing agent, extracted metals from carbonate and organically bound fractions of the sediment samples. This could result in metal accumulation in the floodplains, biomagnification, adverse

  4. The fate of water deposited in the low-lying northern plains

    Science.gov (United States)

    Carr, M. H.

    1993-01-01

    Many large outflow channels terminate in the low-lying northern plains. If the outflow channels formed by running water, as appears likely, then standing bodies of water must have accumulated at the ends of the channels. Most of the observed channels, and hence the bodies of water, are post-Noachian. They formed after the period for which we have the most abundant evidence of climate change. While it has been speculated that the post-Noachian period has experienced large, episodic, climatic excursions, this paper takes the more conservative view that the climatic conditions on Mars, at least from mid-Hesperian onward, were mostly similar to the climatic conditions that prevail in the present epoch. Thus obliquity variations are taken into account, but massive climate changes induced by the floods are considered so improbable that they are ignored.

  5. Deposition flux of aerosol particles and 15 polycyclic aromatic hydrocarbons in the North China Plain.

    Science.gov (United States)

    Wang, Xilong; Liu, Shuzhen; Zhao, Jingyu; Zuo, Qian; Liu, Wenxin; Li, Bengang; Tao, Shu

    2014-04-01

    The present study examined deposition fluxes of aerosol particles and 15 polycyclic aromatic hydrocarbons (PAHs) associated with the particles in the North China Plain. The annual mean deposition fluxes of aerosol particles and 15 PAHs were 0.69 ± 0.46 g/(m(2) ×d) and 8.5 ± 6.2 μg/(m(2) ×d), respectively. Phenanthrene, fluoranthene, pyrene, chrysene, benzo[b]fluoranthene, and benzo[k]fluoranthene were the dominant PAHs bound to deposited aerosol particles throughout the year. The total concentration of 15 PAHs in the deposited aerosol particles was the highest in winter but lowest in spring. The highest PAH concentration in the deposited aerosol particles in winter was because the heating processes highly increased the concentration in atmospheric aerosol particles. Low temperature and weak sunshine in winter reduced the degradation rate of deposited aerosol particle-bound PAHs, especially for those with low molecular weight. The lowest PAH concentration in deposited aerosol particles in spring resulted from the frequently occurring dust storms, which diluted PAH concentrations. The mean deposition flux of PAHs with aerosol particles in winter (16 μg/[m(2) ×d]) reached 3 times to 5 times that in other seasons (3.5-5.0 μg/[m(2) ×d]). The spatial variation of the deposition flux of PAHs with high molecular weight (e.g., benzo[a]pyrene) was consistent with their concentrations in the atmospheric aerosol particles, whereas such a phenomenon was not observed for those with low molecular weight (e.g., phenanthrene) because of their distinct hydrophobicity, Henry's law constant, and the spatially heterogeneous meteorological conditions.

  6. A multidating approach applied to historical slackwater flood deposits of the Gardon River, SE France

    Science.gov (United States)

    Dezileau, L.; Terrier, B.; Berger, J. F.; Blanchemanche, P.; Latapie, A.; Freydier, R.; Bremond, L.; Paquier, A.; Lang, M.; Delgado, J. L.

    2014-06-01

    A multidating approach was carried out on slackwater flood deposits, preserved in valley side rock cave and terrace, of the Gardon River in Languedoc, southeast France. Lead-210, caesium-137, and geochemical analysis of mining-contaminated slackwater flood sediments have been used to reconstruct the history of these flood deposits. These age controls were combined with the continuous record of Gardon flow since 1890, and the combined records were then used to assign ages to slackwater deposits. The stratigraphic records of terrace GE and cave GG were excellent examples to illustrate the effects of erosion/preservation in a context of a progressively self-censoring, vertically accreting sequence. The sedimentary flood record of the terrace GE located at 10 m above the channel bed is complete for years post-1958 but incomplete before. During the 78-year period 1880-1958, 25 floods of a sufficient magnitude (> 1450 m3/s) have covered the terrace. Since 1958, however, the frequency of inundation of the deposits has been lower: only 5 or 6 floods in 52 years have been large enough to exceed the necessary threshold discharge (> 1700 m3/s). The progressive increase of the threshold discharge and the reduced frequency of inundation at the terrace could allow stabilization of the vegetation cover and improve protection against erosion from subsequent large magnitude flood events. The sedimentary flood record seems complete for cave GG located at 15 m above the channel bed. Here, the low frequency of events would have enabled a high degree of stabilization of the sedimentary flood record, rendering the deposits less susceptible to erosion. Radiocarbon dating is used in this study and compared to the other dating techniques. Eighty percent of radiocarbon dates on charcoals were considerably older than those obtained by the other techniques in the terrace. On the other hand, radiocarbon dating on seeds provided better results. This discrepancy between radiocarbon dates on

  7. Flow simulation and flood plain analysis using HEC-RAS model

    National Research Council Canada - National Science Library

    Samira Moradzadeh; Mohsen Irandoust

    2016-01-01

    .... This study is a combination of HEC-RAS hydrological modeling by GIS Software through HEC-GEORAS Amendment, which will estimate the flood zoning, and the due economical damages in the 10kms distance...

  8. Modeling the Impact of Biogeochemical Hotspots and Hot Moments on Subsurface Carbon Fluxes from a Flood Plain Site

    Science.gov (United States)

    Arora, B.; Spycher, N.; Steefel, C. I.; King, E.; Conrad, M. E.

    2015-12-01

    Biogeochemical hotspots and hot moments are known to account for a high percentage of carbon and nutrient cycling within flood plain environments. To quantify the impact of these hotspots and hot moments on the carbon cycle, a 2D reactive transport model was developed for the saturated-unsaturated zone of a flood plain site in Rifle, CO. Previous studies have identified naturally reduced zones (NRZs) in the saturated zone of the Rifle site to be hotspots and important regions for subsurface biogeochemical cycling. Wavelet analysis of geochemical concentrations at the site suggested that hydrologic and temperature variations are hot moments and exert an important control on biogeochemical conditions in the Rifle aquifer. Here, we describe the development of a reactive transport model that couples hydrologic and biogeochemical processes to microbial functional distributions inferred from site-specific 'omic' data. The model includes microbial contributions from heterotrophic and chemolithoautotrophic processes. We use Monod based formulations to represent biomass formation and consider energy partitioning between catabolic and anabolic processes. We use this model to explore community emergence at the Rifle site and further constrain the extent and rates of nutrient uptake as well as abiotic and biotic reactions using stable carbon isotopes. Results from 2D model simulations with only abiotic reactions predict lower CO2 partial pressures in the unsaturated zone and severely underpredict (~200%) carbon fluxes to the river compared to simulations with chemolithoautotrophic pathways. δ13C-CO2 profiles also point to biotic sources for the locally observed high CO2 concentrations above NRZs. Results further indicate that groundwater carbon fluxes from the Rifle site to the river are underestimated by almost 180% (to 3.3 g m-2 d-1) when temperature fluctuations are ignored in the simulations. Preliminary results demonstrate the emergence of denitrifiers at specific depths

  9. Simulation of nitrogen deposition in the North China Plain by the FRAME model

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2011-11-01

    Full Text Available Simulation of atmospheric nitrogen (N deposition in the North China Plain (NCP at high resolution, 5 × 5 km2, was conducted for the first time by the Fine Resolution Atmospheric Multi-pollutant Exchange (FRAME model. The total N deposition budget was 1481 Gg in this region, with 77 % from reduced N and 23 % from oxidized N, and the annual deposition rate (47 kg N ha−1 was much higher than previously reported values for other parts of the world such as the UK (13 kg N ha−1, Poland (7.3 kg N ha−1 and EU27 (8.6 kg N ha−1. The exported N component (1981 Gg was much higher than the imported N component (584 Gg, suggesting that the NCP is an important net emission source of N pollutants. Contributions of N deposition budgets from the seven provinces in this region were proportional to their area ratios. The calculated spatial distributions of N deposition displayed high rates of reduced N deposition in the south and of oxidized N deposition in the eastern part. The N deposition exceeded an upper limit of 30 kg N ha−1 for natural ecosystems over more than 90 % of the region, resulting in terrestrial ecosystem deterioration, impaired air quality and coastal eutrophication not only in the NCP itself but also in surrounding areas including the Bohai Sea and the Yellow Sea.

  10. Digital geospatial presentation of geoelectrical and geotechnical data for the lower American River and flood plain, east Sacramento, California

    Science.gov (United States)

    Ball, Lyndsay B.; Burton, Bethany L.; Powers, Michael H.; Asch, Theodore H.

    2015-01-01

    To characterize the extent and thickness of lithologic units that may have differing scour potential, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, has performed several geoelectrical surveys of the lower American River channel and flood plain between Cal Expo and the Rio Americano High School in east Sacramento, California. Additional geotechnical data have been collected by the U.S. Army Corps of Engineers and its contractors. Data resulting from these surveys have been compiled into similar database formats and converted to uniform geospatial datums and projections. These data have been visualized in a digital three-dimensional framework project that can be viewed using freely available software. These data facilitate a comprehensive analysis of the resistivity structure underlying the lower American River corridor and assist in levee system management.

  11. Heavy metal contaminations in the groundwater of Brahmaputra flood plain: an assessment of water quality in Barpeta District, Assam (India).

    Science.gov (United States)

    Haloi, Nabanita; Sarma, H P

    2012-10-01

    A study was conducted to evaluate the heavy metal contamination status of groundwater in Brahmaputra flood plain Barpeta District, Assam, India. The Brahmaputra River flows from the southern part of the district and its many tributaries flow from north to south. Cd, Fe, Mn, Pb, and Zn are estimated by using atomic absorption spectrometer, Perkin Elmer AA 200. The quantity of heavy metals in drinking water should be checked time to time; as heavy metal accumulation will cause numerous problems to living being. Forty groundwater samples were collected mainly from tube wells from the flood plain area. As there is very little information available about the heavy metal contamination status in the heavily populated study area, the present work will help to be acquainted with the suitability of groundwater for drinking applications as well as it will enhance the database. The concentration of iron exceeds the WHO recommended levels of 0.3 mg/L in about 80% of the samples, manganese values exceed 0.4 mg/L in about 22.5% of the samples, and lead values also exceed limit in 22.5% of the samples. Cd is reported in only four sampling locations and three of them exceed the WHO permissible limit (0.003 mg/L). Zinc concentrations were found to be within the prescribed WHO limits. Therefore, pressing awareness is needed for the betterment of water quality; for the sake of safe drinking water. Statistical analysis of the data was carried out using Special Package for Social Sciences (SPSS 16).

  12. Aboveground production and nutrient circulation along a flooding gradient in a South Carolina Coastal Plain forest

    Science.gov (United States)

    Marianne K. Burke; B. Graeme Lockaby; William H. Conner

    1999-01-01

    Relative to effects of flooding, little is known about the influence of hydrology-nutrient interactions on aboveground net primary production (NPP) in forested wetlands. The authors found that nutrient circulation and NPP were closely related along a complex physical, chemical, and hydrologic gradient in a bottomland hardwood forest with four distinct communities....

  13. Physical and chemical properties of deposited airborne particulates over the Arabian Red Sea coastal plain

    Directory of Open Access Journals (Sweden)

    J. P. Engelbrecht

    2017-09-01

    Full Text Available Mineral dust is the most abundant aerosol, having a profound impact on the global energy budget. This research continues our previous studies performed on surface soils in the Arabian Peninsula, focusing on the mineralogical, physical and chemical composition of dust deposits from the atmosphere at the Arabian Red Sea coast. For this purpose, aerosols deposited from the atmosphere are collected during 2015 at six sites on the campus of the King Abdullah University of Science and Technology (KAUST situated on the Red Sea coastal plain of Saudi Arabia and subjected to the same chemical and mineralogical analysis we conducted on soil samples. Frisbee deposition samplers with foam inserts were used to collect dust and other deposits, for the period December 2014 to December 2015. The average deposition rate measured at KAUST for this period was 14 g m−2 per month, with lowest values in winter and increased deposition rates in August to October. The particle size distributions provide assessments of  < 10 and  < 2.5 µm dust deposition rates, and it is suggested that these represent proxies for PM10 (coarse and PM2. 5 (fine particle size fractions in the dust deposits.X-ray diffraction (XRD analysis of a subset of samples confirms variable amounts of quartz, feldspars, micas, and halite, with lesser amounts of gypsum, calcite, dolomite, hematite, and amphibole. Freeze-dried samples were re-suspended onto the Teflon® filters for elemental analysis by X-ray fluorescence (XRF, while splits from each sample were analyzed for water-soluble cations and anions by ion chromatography. The dust deposits along the Red Sea coast are considered to be a mixture of dust emissions from local soils and soils imported from distal dust sources. Airborne mineral concentrations are greatest at or close to dust sources, compared to those through medium- and long-range transport. It is not possible to identify the exact origin of deposition samples from

  14. Physical and chemical properties of deposited airborne particulates over the Arabian Red Sea coastal plain

    KAUST Repository

    Engelbrecht, Johann

    2017-09-27

    Mineral dust is the most abundant aerosol, having a profound impact on the global energy budget. This research continues our previous studies performed on surface soils in the Arabian Peninsula, focusing on the mineralogical, physical and chemical composition of dust deposits from the atmosphere at the Arabian Red Sea coast. For this purpose, aerosols deposited from the atmosphere are collected during 2015 at six sites on the campus of the King Abdullah University of Science and Technology (KAUST) situated on the Red Sea coastal plain of Saudi Arabia and subjected to the same chemical and mineralogical analysis we conducted on soil samples. Frisbee deposition samplers with foam inserts were used to collect dust and other deposits, for the period December 2014 to December 2015. The average deposition rate measured at KAUST for this period was 14 g m−2 per month, with lowest values in winter and increased deposition rates in August to October. The particle size distributions provide assessments of  < 10 and  < 2.5 µm dust deposition rates, and it is suggested that these represent proxies for PM10 (coarse) and PM2. 5 (fine) particle size fractions in the dust deposits. X-ray diffraction (XRD) analysis of a subset of samples confirms variable amounts of quartz, feldspars, micas, and halite, with lesser amounts of gypsum, calcite, dolomite, hematite, and amphibole. Freeze-dried samples were re-suspended onto the Teflon® filters for elemental analysis by X-ray fluorescence (XRF), while splits from each sample were analyzed for water-soluble cations and anions by ion chromatography. The dust deposits along the Red Sea coast are considered to be a mixture of dust emissions from local soils and soils imported from distal dust sources. Airborne mineral concentrations are greatest at or close to dust sources, compared to those through medium- and long-range transport. It is not possible to identify the exact origin of deposition samples from the

  15. Depositional evolution of the Lower Khuzestan plain (SW Iran) since the end of the Late Pleistocene

    Science.gov (United States)

    Bogemans, Frieda; Janssens, Rindert; Baeteman, Cecile

    2017-09-01

    A detailed sedimentological investigation of sixty-six cores supported by radiocarbon age determination enabled the reconstruction of the depositional environmental evolution since the end of the Late Pleistocene in the Iranian part of the Mesopotamian plain. Both fluvial and estuarine environments have been identified on the basis of the sediment characteristics and their between-core stratigraphic correlations. At the end of the Late Pleistocene the fluvial behaviour allowed only the deposition of sand. Prior to 12400-12040 yr cal BP the palaeohydraulics changed by which heterolithic fluvial facies were deposited. Shortly after 12400 - 12040 yr cal BP an erosional phase caused the incision of depressions most probably because of a climate change to further arid conditions. In the early Holocene, mud-dominated river systems filled the depressions; a situation that lasted at least until 7900 - 7700 yr cal BP. After this period tides invaded via the active channels in the downstream part of the area, which turned into an estuarine environment for a period of about 2000-2500 years. Tidal influence diminished and stopped around 5000 yr cal BP because of progradation. Fluvial processes dominated again the sedimentary environment in the study area, except at the southern margin of it where tides controlled, although very locally, the environment.

  16. Identifying heavy metal levels in historical flood water deposits using sediment cores.

    Science.gov (United States)

    Lintern, Anna; Leahy, Paul J; Heijnis, Henk; Zawadzki, Atun; Gadd, Patricia; Jacobsen, Geraldine; Deletic, Ana; Mccarthy, David T

    2016-11-15

    When designing mitigation and restoration strategies for aquatic systems affected by heavy metal contamination, we must first understand the sources of these pollutants. In this study, we introduce a methodology that identifies the heavy metal levels in floodplain lake sediments deposited by one source; fluvial floods. This is done by comparing sediment core heavy metal profiles (i.e., historical pollution trends) to physical and chemical properties of sediments in these cores (i.e., historical flooding trends). This methodology is applied to Willsmere and Bolin Billabongs, two urban floodplain lakes (billabongs) of the Yarra River (South-East Australia). Both billabongs are periodically inundated by flooding of the Yarra River and one billabong (Willsmere Billabong) is connected to an urban stormwater drainage network. 1-2-m long sediment cores (containing sediment deposits up to 500 years old) were taken from the billabongs and analysed for heavy metal concentrations (arsenic, chromium, copper, lead, nickel, zinc). In cores from both billabongs, arsenic concentrations are high in the flood-borne sediments. In Bolin Billabong, absolute metal levels are similar in flood and non-flood deposits. In Willsmere Billabong, absolute copper, lead and zinc levels were generally lower in fluvial flood-borne sediments in the core compared to non-fluvial sediments. This suggests that heavy metal concentrations in Bolin Billabong sediments are relatively similar regardless of whether or not fluvial flooding is occurring. However for Willsmere Billabong, heavy metal concentrations are high when overland runoff, direct urban stormwater discharges or atmospheric deposition is occurring. As such, reducing the heavy metal concentrations in these transport pathways will be of great importance when trying to reduce heavy metal concentrations in Willsmere Billabong sediments. This study presents a proof-of-concept that can be applied to other polluted aquatic systems, to understand the

  17. An Estimation of the Size Composition and Condition Factor of Ophiocara Porocephala from Amassoma Flood Plains, Niger Delta, Nigeria

    Directory of Open Access Journals (Sweden)

    E.N. Ogamba

    2013-06-01

    Full Text Available An estimation of the size composition and condition factor of Ophiocara porocephala from Amassoma flood plains, Niger Delta, Nigeria was carried out for a period of six months (April-June 2010 and November, 2011- January, 2012 to assess aspects of the fishery status. The flood plain of Amassoma is one of the low lands in Niger Delta providing nursery and breeding grounds for variety of both finfish and shell fish species. Fish plays on important role in the development of a nation. Apart from being a cheap source of highly nutritive protein, it also contains other essential nutrients required by the body. Therefore the study of condition factor and size composition of Ophiocara porocephala from Amassoma flood plains will provide information on the amount of stock available for the fishery, evaluation of production, information for stock sizes, an important information for the evaluation of mortalities and status of the fish population, estimating the average weight at a given length group and an index of growth and feeding intensity. Length measurement values ranged from 8.2-15.3 cm; while width, weight and condition factor measurement values ranged from 1.2-2.5 cm, 3.98 g–40.35 g and 0.29-1.78. The highest length frequency (26 was estimated for values ranging from 11.5-12.5 with class mark 12.0 mm. The lowest length frequency (1 was estimated for length range 14.8-15.8 mm with class mark 15.3 mm. The highest width frequency (27 was estimated for values ranging 1.8-1.9 mm with class mark 1.85 mm. The lowest width frequency (2 was estimated for values ranging from 2.2-2.4 and 2.5 -2.6 mm with class marks 2.45 and 2.65 mm, respectively. The highest weight frequency (31 was estimated for values ranging from 10.0-14.9 g with class mark 12.45 g. The lowest weight frequency (2 was estimated for values ranging 6. 0-10.9 g with class mark 8.45 g. The highest condition factor frequency (49 was estimated for values ranging from 0.9-1.1 with class mark 1

  18. 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 ...

  19. Biotopes of Aedes vexans development in the long flood-plain forest of the Dnipro river

    Directory of Open Access Journals (Sweden)

    N. V. Voronova

    2005-02-01

    Full Text Available The aim of the research was to estimate the role of different types of biotopes in a formation of the Aedes vexans high ecological valency. The greatest number of Ae. vexans mosquitoes procreate in basins with the moderate density of larvae (49.6–70.2 %, less mosquitoes procreate in basins with the high one (15.9–19.0 %. The optimal and effective density for the development of mosquitoes larvae in temporary basins of a long while flooded forest of the Dnipro river is 350–1700 specimens/m2, that’s why it is necessary just to pay attention to them during taking measures on reducing their numbers.

  20. Compared leaf anatomy of Nymphaea (Nymphaeaceae) species from Brazilian flood plain.

    Science.gov (United States)

    Catian, G; Scremin-Dias, E

    2013-11-01

    Nymphaea has seven species already catalogued in the flood prone areas of the Brazilian Pantanal. However, some species remain difficult to identify and descriptions of the anatomy of vegetative organs are an important tool for infrageneric separation to aid in group taxonomy. The species collected in the Pantanal and prepared according to the usual techniques for anatomical studies showed similar structural characteristics, and data on the arrangement of vascular bundles in the midrib and petiole, as well as the form and distribution of sclereids, were consistent. Nymphaea oxypetala stands out from the other evaluated species for having a greater number of differential characters, including angular collenchyma and the absence of bicollateral bundles in the petiole. Nymphaea lingulata stands out as the only species to feature bicollateral bundles in the leaf blade. The results, summarised in the dichotomous key, facilitate the identification of species that use the flower as the main differentiation, but are in a vegetative stage.

  1. Compared leaf anatomy of Nymphaea (Nymphaeaceae species from Brazilian flood plain

    Directory of Open Access Journals (Sweden)

    G Catian

    Full Text Available Nymphaea has seven species already catalogued in the flood prone areas of the Brazilian Pantanal. However, some species remain difficult to identify and descriptions of the anatomy of vegetative organs are an important tool for infrageneric separation to aid in group taxonomy. The species collected in the Pantanal and prepared according to the usual techniques for anatomical studies showed similar structural characteristics, and data on the arrangement of vascular bundles in the midrib and petiole, as well as the form and distribution of sclereids, were consistent. Nymphaea oxypetala stands out from the other evaluated species for having a greater number of differential characters, including angular collenchyma and the absence of bicollateral bundles in the petiole. Nymphaea lingulata stands out as the only species to feature bicollateral bundles in the leaf blade. The results, summarised in the dichotomous key, facilitate the identification of species that use the flower as the main differentiation, but are in a vegetative stage.

  2. Spatial variability and uncertainty in ecological risk assessment: a case study on the potential risk of cadmium for the little owl in a Dutch river flood plain.

    Science.gov (United States)

    Kooistra, Lammert; Huijbregts, Mark A J; Ragas, Ad M J; Wehrens, Ron; Leuven, Rob S E W

    2005-04-01

    This paper outlines a procedure that quantifies the impact of different sources of spatial variability and uncertainty on ecological risk estimates. The procedure is illustrated in a case study that estimates the risks of cadmium for a little owl (Athene noctua vidalli) living in a Dutch river flood plain along the river Rhine. A geographical information system (GIS) was used to quantify spatial variability in contaminant concentrations and habitats. It was combined with an exposure and effect model that uses Monte Carlo simulation to quantify parameter uncertainty. Spatial model uncertainty was assessed by the application of two different spatial interpolation methods (classification and kriging) and foraging ranges. The results of the case study show that parameter uncertainty is the main type of uncertainty influencing the risk estimate, and to a lesser extent spatial variability, while spatial model uncertainty was of minor importance. Compared to the deterministically calculated hazard index for the little owl (0.9), inclusion of spatial variability resulted in a median hazard index that can vary between 0.8 and 1.4. It is concluded that a single estimator for a whole flood plain may over- or underestimate risks for specific parts within the flood plain. Further research that expands the procedure presented in this paper is necessary to improve the incorporation of spatial factors in ecological risk assessment.

  3. Formation of fine sediment deposit from a flash flood river in the Mediterranean Sea

    Science.gov (United States)

    Grifoll, Manel; Gracia, Vicenç; Aretxabaleta, Alfredo L.; Guillén, Jorge; Espino, Manuel; Warner, John C.

    2014-01-01

    We identify the mechanisms controlling fine deposits on the inner-shelf in front of the Besòs River, in the northwestern Mediterranean Sea. This river is characterized by a flash flood regime discharging large amounts of water (more than 20 times the mean water discharge) and sediment in very short periods lasting from hours to few days. Numerical model output was compared with bottom sediment observations and used to characterize the multiple spatial and temporal scales involved in offshore sediment deposit formation. A high-resolution (50 m grid size) coupled hydrodynamic-wave-sediment transport model was applied to the initial stages of the sediment dispersal after a storm-related flood event. After the flood, sediment accumulation was predominantly confined to an area near the coastline as a result of preferential deposition during the final stage of the storm. Subsequent reworking occurred due to wave-induced bottom shear stress that resuspended fine materials, with seaward flow exporting them toward the midshelf. Wave characteristics, sediment availability, and shelf circulation determined the transport after the reworking and the final sediment deposition location. One year simulations of the regional area revealed a prevalent southwestward average flow with increased intensity downstream. The circulation pattern was consistent with the observed fine deposit depocenter being shifted southward from the river mouth. At the southern edge, bathymetry controlled the fine deposition by inducing near-bottom flow convergence enhancing bottom shear stress. According to the short-term and long-term analyses, a seasonal pattern in the fine deposit formation is expected.

  4. Innovative strategies for high resolution site characterization: application to a flood plain

    Directory of Open Access Journals (Sweden)

    Thomas Vienken

    2014-12-01

    Full Text Available Solving complex hydrogeological problems often requires a thorough understanding of (hydro- geological subsurface conditions. This is especially true for sedimentary deposits with complex architecture, where lithology and/or hydraulic properties can significantly vary over short horizontal and vertical distances. At these sites, a traditional, solely sample-based investigation approach is often not applicable due to limited data accuracy, resolution, and efficiency. Instead, an adapted investigation approach is required that combines exploration technologies of different resolution and investigation scales. This paper aims to demonstrate the feasibility of such a multi-scale approach for the characterization of a test site near the city of Löbnitz, Germany, that is comprised of heterogeneous alluvial deposits. Our focus is on site characterization in terms of lithology and hydraulic properties, as well as on the delineation and characterization of an aggradated oxbow as a typical example of a small scale geological structure.

  5. Huge, CO2-charged debris-flow deposits and tectonic sagging in the northern plains of Mars

    Science.gov (United States)

    Tanaka, K.L.; Banerdt, W.B.; Kargel, J.S.; Hoffman, N.

    2001-01-01

    The northern plains of Mars contain a vast deposit, covering one-sixth of the planet, that apparently resulted in extensive lithospheric deformation. The center of the deposit may be as much as 2-3 km thick. The deposit has lobate margins consistent with the flow of fluidized debris for hundreds to thousands of kilometers derived from highland and high-plains sources. The deposit surface lowers inward by ???900 m in places and is locally bordered by a bulge ???300 m high. Similar deformation accompanied development of Pleistocene ice sheets on Earth. The lack of burial of a large inlier of older terrain and the response time of the mantle to the loading require that the deposit was emplaced in <1000 yr, assuming that the deposit was originally flat. We account for what may have been the largest catastrophic erosional and/or depositional event in solar system history by invoking pore-filling subsurface CO2 as an active agent in the processes of source-rock collapse and debris flow.

  6. Geomorphic variation in riparian tree mortality and stream coarse woody debris recruitment from record flooding in a coastal plain stream

    Science.gov (United States)

    Brian J. Palik; Stephen W. Golladay; P. Charles Goebel; Brad W. Taylor

    1998-01-01

    Large floods are an important process controlling the structure and function of stream ecosystems. One of the ways floods affect streams is through the recruitment of coarse woody debris from stream-side forests. Stream valley geomorphology may mediate this interaction by altering flood velocity, depth, and duration. Little research has examined how floods and...

  7. Gravel deposit produced by a flash paleoflood in a succession of Quaternary terraces in the Plain of Vic (NE Iberian Peninsula)

    Science.gov (United States)

    Castelltort, Xavier; Colombo, Ferran; Carles Balasch, Josep; Barriendos, Mariano; Mazón, Jordi; Pino, David; Lluís Ruiz-Bellet, Josep; Tuset, Jordi

    2016-04-01

    In contrast with the abundance of studies of fluvial terraces, caused by river dynamics, there are very few descriptions of alluvial deposits produced by flash floods and mass movements. This study describes a late Pleistocene sedimentary deposit produced by a flash paleoflood and attempts to explain its genesis and its source areas. The Plain of Vic, drained by the river Ter and its tributaries, is one of the eastern erosive basins bordering the sedimentary Ebre basin (NE Iberian Peninsula). This plain has a length of 35 km and an average width of 8 km with a N-S direction and lies mainly on the Marls of Vic Fm. These materials are the less resistant lithologic members of the monocline Paleogene stratigraphic succession that dips to the west. The basal resistant bed that forms the eastern cuesta is the Sandstones of Folgueroles Fm. On the top, the resistant lithologic beds that form the scarp face are the sandstones of La Noguera in the Vidrà Fm. On the scarp face, various coalescent alluvial bays have been developed, which have accumulated up to eight levels of alluvial terraces. In one of them, formed by the river Mèder and the Muntanyola stream, a gravel deposit up to 5 m thick formed in a single episode outcrops, in a position T4,. A dating of the river Ter T5 has obtained an age of 117.9 ± 9.5 Ky. The accumulation of gravel erodes another level of metric thickness of the same lithological characteristics and texture. The deposit does not have any internal structure or organization of pebbles. At its base, there are several metric blocks coming directly from the slopes. The accumulation of gravel is block-supported with a sandy matrix. The pebbles size is centimetric to decimetric (90%). Its texture is subrounded. Lithologically, the deposit consists mostly of sandstone and limestone from the top of the series. On the ground, the accumulation of gravel is elongated, with a maximum length and width of 550 m by 160 m and a slope surface of 2.54%. With an area

  8. Paleoclimatic significance of Late Quaternary eolian deposition on the Piedmont and High Plains, Central United States

    Science.gov (United States)

    Forman, Steven L.; Oglesby, Robert; Markgraf, Vera; Stafford, Thomas

    1995-06-01

    Presently stabilized dune systems on the piedmont of eastern Colorado and adjacent High Plains have been repeatedly re-activated during the past 20,000 years. Radiocarbon and thermoluminescence age estimates indicate eolian activity late in the last glacial cycle ca. 20,000-12,000 yr B.P. and subsequent episodes of dune reactivation at ca. 6000, 4500 and 1000 yr B.P. Pollen analysis from aggraded buried soil A horizons show a shift from grasses and shrubs to goosefoot, a disturbance indicator. The association of maximum goosefoot levels with the coarsest part of the buried A horizon immediately prior to burial by eolian sand indicates a substantial reduction in grass and dominance of shrubs with onset of eolian activity. The vegetation change and eolian depositional sequence indicates a reduction in plant coverage with regional drought, possibly augmented by bison grazing and surface heating effects. We infer an increase in summer monsoonal precipitation between 13,000 and 9000 yr B.P. reflecting a heightened land-to-sea temperature gradient associated with rising summer solar-insolation values and a meltwater cooled Gulf of Mexico. Dune reactivation in the middle and late Holocene appears to be independent of summer insolation values, but rather reflects a small (< 10°) easterly shift of the Bermuda High and western ridge aloft, difficult parameters to link to a cause and to resolve with climate models.

  9. Early diagenesis of recently deposited organic matter: A 9-yr time-series study of a flood deposit

    Science.gov (United States)

    Tesi, T.; Langone, L.; Goñi, M. A.; Wheatcroft, R. A.; Miserocchi, S.; Bertotti, L.

    2012-04-01

    In Fall 2000, the Po River (Italy) experienced a 100-yr return period flood that resulted in a 1-25 cm-thick deposit in the adjacent prodelta (10-25 m water depth). In the following years, numerous post-depositional perturbations occurred including bioturbation, reworking by waves with heights exceeding 5 m, as well as periods of extremely high and low sediment supply. Cores collected in the central prodelta after the Fall 2000 flood and over the following 9 yr, allowed characterization of the event-strata in their initial state and documentation of their subsequent evolution. Sedimentological characteristics were investigated using X-radiographs and sediment texture analyses, whereas the composition of sedimentary organic matter (OM) was studied via bulk and biomarker analyses, including organic carbon (OC), total nitrogen (TN), carbon stable isotope composition (δ13C), lignin phenols, cutin-products, p-hydroxy benzenes, benzoic acids, dicarboxylic acids, and fatty acids. The 9-yr time-series analysis indicated that roughly the lower half of the original event bed was preserved in the sediment record. Conversely, the upper half of the deposit experienced significant alterations including bioturbation, addition of new material, as well as coarsening. Comparison of the recently deposited material with 9-yr old preserved strata represented a unique natural laboratory to investigate the diagenesis of sedimentary OM in a non-steady system. Bulk data indicated that OC and TN were degraded at similar rates (loss ∼17%) whereas biomarkers exhibited a broad spectrum of reactivities (loss from ∼6% to ∼60%) indicating selective preservation during early diagenesis. Given the relevance of episodic sedimentation in several margins, this study has demonstrated the utility of event-response and time-series sampling of the seabed for understanding the early diagenesis in non-steady conditions.

  10. Age and correlation of emerged pliocene and pleistocene deposits, U.S. Atlantic Coastal Plain

    Science.gov (United States)

    Cronin, T. M.; Bybell, L.M.; Poore, R.Z.; Blackwelder, B. W.; Liddicoat, J.C.; Hazel, J.E.

    1984-01-01

    Paleontologic and paleomagnetic investigations were conducted on several hundred Pliocene and Pleistocene marine samples from five regions of the emerged Atlantic Coastal Plain: (1) the Delmarva Peninsula, (2) eastern Virginia, (3) central and northern North Carolina, (4) southern North Carolina and northeastern South Carolina, and (5) the Charleston area, South Carolina. Molluscan and ostracode interval and assemblage zonations, which are the primary means of regional correlation, have been calibrated using planktic biochronologic, paleomagnetic, radiometric and amino-acid recemization data. These multiple dating criteria were used to determine the age and, where possible, the duration of marine transgressive/regressive sequences. A correlation chart illustrates the age relationships of 27 formations from five regions. One important conclusion is some of the Yorktown Formation of Virginia and North Carolina (including the "Duplin" Formation), and some of the Raysor of South Carolina are late Pliocene in age. The late Pliocene Chowan River Formation of North Carolina is older than the early Pleistocene Waccamaw Formation of South Carolina, which in turn may be older than the James City Formation of North Carolina. During the last 1.0 million years, multiple marine transgressions occurred in each region, but the age of these middle and late Pleistocene formations often may differ from one area to the next. A significant result of the study is the evidence for the lack of time equivalence of formations in the five different regions; that is, the sequence of marine transgressions in one region does not necessarily correspond to that in another. This appears to be the result of differing subsidence and uplift histories, the patchiness of the depositional record, and the limitations of the dating techniques in light of the rapidity and frequency of sea-level fluctuations. ?? 1984.

  11. Mega deposits and erosive features related to the glacial lake Nedre Glomsjø outburst flood, southeastern Norway

    Science.gov (United States)

    Høgaas, Fredrik; Longva, Oddvar

    2016-11-01

    In this paper we present a suite of erosional remnants, mega deposits and subtle bar morphology that we relate to the outburst flood from the glacial lake Nedre Glomsjø at the end of the last Ice Age. By using large datasets of airborne LiDAR data implemented in a geographic information system (GIS), we have mapped flood related features along the Glomma and Vrangselva rivers in southeastern Norway. The unprecedented overview of the valley reaches obtained by the vegetation-free LiDAR-derived digital elevation models (DEM) has revealed a set of hitherto undocumented landforms. Persisting erosive lines - indicators of the uppermost flooded level - are carved into surficial deposits in the hillsides and are found as high as 80-90 m above the modern valley floor. By using the indicators as an upper flood boundary, we have computed cross-sectional profiles showing that the flood in some reaches inundated more than 120 000 m2 of the valley. Large, streamlined bed forms, which we interpret as flood bars, drape sections of the valley floor, some several kilometers long. The most morphologically striking - pendant bars - are developed behind flood flow projections, such as bedrock knolls or in lee of a valley bend. Flood bars occur in the entire study area, but are more widespread in the north and generally decrease in size moving in a downstream direction. Kettle holes and ice-block obstacle marks from icebergs arrested during the flood are common. These features support the theory of a catastrophic drainage event, but also indicate a pattern of differential erosion and deposition that allowed us to interpret palaeoflow on individual bars. Vast aeolian dune fields in the region are interpreted as a secondary product of the flood, as deposits related to the event were mobilised by northerly winds momentarily after the flood waned. The dune fields cover an excess of 50 km2 and reveal that the region was a highly active periglacial desert after the flood. Our mapping

  12. On the use of InSAR technology to assess land subsidence in Jakarta coastal flood plain

    Science.gov (United States)

    Koudogbo, Fifame; Duro, Javier; Garcia Robles, Javier; Arnaud, Alain; Abidin, Hasanuddin Z.

    2014-05-01

    Jakarta is the capital of Indonesia and is home to approximately 10 million people on the coast of the Java Sea. It is situated on the northern coastal alluvial plane of Java which shares boundaries with West Java Province in the south and in the east, and with Banten Province in the west. The Capital District of Jakarta (DKI) sits in the lowest lying areas of the basin. Its topography varies, with the northern part just meters above current sea level and lying on a flood plain. Subsequently, this portion of the city frequently floods. The southern part of the city is hilly. Thirteen major rivers flow through Jakarta to the Java Sea. The Ciliwung River is the most significant river and divides the city West to East. In the last three decades, urban growing of Jakarta has been very fast in sectors as industry, trade, transportation, real estate, among others. This exponential development has caused several environmental issues; land subsidence is one of them. Subsidence in Jakarta has been known since the early part of the 20th century. It is mainly due to groundwater extraction, the fast development (construction load), soil natural consolidation and tectonics. Evidence of land subsidence exists through monitoring with GPS, level surveys and InSAR investigations. InSAR states for "Interferometric Synthetic Aperture Radar". Its principle is based on comparing the distance between the satellite and the ground in consecutive satellite passes over the same area on the Earth's surface. Radar satellites images record, with very high precision, the distance travelled by the radar signal that is emitted by the satellite is registered. When this distance is compared through time, InSAR technology can provide highly accurate ground deformation measurements. ALTAMIRA INFORMATION, company specialized in ground motion monitoring, has developed GlobalSARTM, which combines several processing techniques and algorithms based on InSAR technology, to achieve ground motion

  13. Evidence of flash floods in Precambrian gravel dominated ephemeral river deposits

    Science.gov (United States)

    Long, Darrel G. F.

    2017-01-01

    Fluvial strata at the base of the Whyte Inlet Formation on Baffin Island, to the west of Sikosak Bay, are predominantly boulder and cobble bearing large pebble conglomerates of braided fluvial origin. Local development of narrow sinuous channels, possibly within the thalwegs of an initially braided bedrock confined system, is indicated by the presence of lateral accretion surfaces, some of which host isolated sub-vertically oriented boulders. These larger boulders were probably emplaced during exceptional flood events involving either hyper-concentrated flows or dilute debris flows, with velocities in the order of 2.2 m/s. Isolated ridges of boulders and cobbles are perched on the upper parts of lateral accretion surfaces in mixed sandy-gravelly fluvial intervals. These boulder berms developed down stream from channel bends or bedrock constrictions in response to flow expansion during flash floods, with estimated peak discharge of about 1.4 m/s. Associated sandstones on lateral accretion surfaces show evidence of deposition under both upper and lower flow conditions. Similar boulder and cobble berms of this type are known from modern ephemeral and highly seasonal fluvial systems in a wide range of climatic settings, and are a clear indication that highly variable to catastrophic discharge events affected the rivers responsible for deposition of these conglomerates.

  14. Flood Zones, Villa Rica, Georgia Flood Plain Map, Published in 2005, 1:12000 (1in=1000ft) scale, Chattahoochee-Flint Regional Development.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Flood Zones dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from Hardcopy Maps information as of 2005. It is described as 'Villa...

  15. Genetic and grade and tonnage models for sandstone-hosted roll-type uranium deposits, Texas Coastal Plain, USA

    Science.gov (United States)

    Hall, Susan M.; Mihalasky, Mark J.; Tureck, Kathleen; Hammarstrom, Jane M.; Hannon, Mark

    2017-01-01

    The coincidence of a number of geologic and climatic factors combined to create conditions favorable for the development of mineable concentrations of uranium hosted by Eocene through Pliocene sandstones in the Texas Coastal Plain. Here 254 uranium occurrences, including 169 deposits, 73 prospects, 6 showings and 4 anomalies, have been identified. About 80 million pounds of U3O8 have been produced and about 60 million pounds of identified producible U3O8 remain in place. The development of economic roll-type uranium deposits requires a source, large-scale transport of uranium in groundwater, and deposition in reducing zones within a sedimentary sequence. The weight of the evidence supports a source from thick sequences of volcanic ash and volcaniclastic sediment derived mostly from the Trans-Pecos volcanic field and Sierra Madre Occidental that lie west of the region. The thickest accumulations of source material were deposited and preserved south and west of the San Marcos arch in the Catahoula Formation. By the early Oligocene, a formerly uniformly subtropical climate along the Gulf Coast transitioned to a zoned climate in which the southwestern portion of Texas Coastal Plain was dry, and the eastern portion humid. The more arid climate in the southwestern area supported weathering of volcanic ash source rocks during pedogenesis and early diagenesis, concentration of uranium in groundwater and movement through host sediments. During the middle Tertiary Era, abundant clastic sediments were deposited in thick sequences by bed-load dominated fluvial systems in long-lived channel complexes that provided transmissive conduits favoring transport of uranium-rich groundwater. Groundwater transported uranium through permeable sandstones that were hydrologically connected with source rocks, commonly across formation boundaries driven by isostatic loading and eustatic sea level changes. Uranium roll fronts formed as a result of the interaction of uranium-rich groundwater

  16. Investigation of the 2006 drought and 2007 flood extremes at the Southern Great Plains through an integrative analysis of observations

    Science.gov (United States)

    Dong, Xiquan; Xi, Baike; Kennedy, Aaron; Feng, Zhe; Entin, Jared K.; Houser, Paul R.; Schiffer, Robert A.; L'Ecuyer, Tristan; Olson, William S.; Hsu, Kuo-Lin; Liu, W. Timothy; Lin, Bing; Deng, Yi; Jiang, Tianyu

    2011-02-01

    Hydrological years 2006 (HY06; October 2005 to September 2006) and 2007 (HY07; October 2006 to September 2007) provide a unique opportunity to examine hydrological extremes in the central United States because there are no other examples of two such highly contrasting precipitation extremes occurring in consecutive years at the Southern Great Plains (SGP) in recorded history. The HY06 annual precipitation in the state of Oklahoma, as observed by the Oklahoma Mesonet, is around 61% of the normal (92.84 cm, based on the 1921-2008 climatology), which results in HY06 as the second-driest year in the record. In particular, the total precipitation during the winter of 2005-2006 is only 27% of the normal, and this winter ranks as the driest season. On the other hand, the HY07 annual precipitation amount is 121% of the normal, and HY07 ranks as the seventh-wettest year for the entire state and the wettest year for the central region of the state. Summer 2007 is the second-wettest season for the state. Large-scale dynamics play a key role in these extreme events. During the extreme dry period (11/2005-02/2006), a dipole pattern in the 500 hPa geopotential height anomaly existed where an anomalous high was over the southwestern U.S. region and an anomalous low was over the Great Lakes. This pattern is associated with inhibited moisture transport from the Gulf of Mexico and strong sinking motion over the SGP, both contributing to the extreme dryness. The precipitation deficit over the SGP during the extreme dry period is clearly linked to significantly suppressed cyclonic activity over the southwestern United States, which shows a robust relationship with the western Pacific teleconnection pattern. The precipitation events during the extreme wet period (May-July 2007) were initially generated by active synoptic weather patterns, linked with moisture transport from the Gulf of Mexico by the northward low-level jet, and enhanced the frequency of thunderstorms and their

  17. 100-Year Floodplains, flood plain, Published in 2009, 1:24000 (1in=2000ft) scale, Washington County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This 100-Year Floodplains dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is described as 'flood...

  18. Assessment of the effects of farming and conservation programs on pesticide deposition in high plains wetlands.

    Science.gov (United States)

    Belden, Jason B; Hanson, Brittany Rae; McMurry, Scott T; Smith, Loren M; Haukos, David A

    2012-03-20

    We examined pesticide contamination in sediments from depressional playa wetlands embedded in the three dominant land-use types in the western High Plains and Rainwater Basin of the United States including cropland, perennial grassland enrolled in conservation programs (e.g., Conservation Reserve Program [CRP]), and native grassland or reference condition. Two hundred and sixty four playas, selected from the three land-use types, were sampled from Nebraska and Colorado in the north to Texas and New Mexico in the south. Sediments were examined for most of the commonly used agricultural pesticides. Atrazine, acetochlor, metolachlor, and trifluralin were the most commonly detected pesticides in the northern High Plains and Rainwater Basin. Atrazine, metolachlor, trifluralin, and pendimethalin were the most commonly detected pesticides in the southern High Plains. The top 5-10% of playas contained herbicide concentrations that are high enough to pose a hazard for plants. However, insecticides and fungicides were rarely detected. Pesticide occurrence and concentrations were higher in wetlands surrounded by cropland as compared to native grassland and CRP perennial grasses. The CRP, which is the largest conservation program in the U.S., was protective and had lower pesticide concentrations compared to cropland.

  19. Identifying flood deposits in lake sediments: Changing frequencies and potential links to long-term climate change

    Energy Technology Data Exchange (ETDEWEB)

    Stoeren, Eivind Wilhelm Nagel

    2011-05-15

    This thesis consists of an introduction and three individual papers that investigate the possibility for identifying the sedimentary imprint of catchment processes in lake sediments, emphasising on extreme events and in particular those deposited by river floods. Three individual lake sediment basins in southern Norway have been studied and changes in the frequency of such events are reconstructed for the last c. 10,000 years. In Paper I, the sediments of the glacier-fed Lake Russvatnet in eastern Jotunheimen (61' N 8' E) were studied. The record comprises a combination of glacier-derived material produced by the glacier Blackwellbreen and also several episodic processes in the catchment area such as floods and debris flows. In order to distinguish late- Holocene (last 4000 years) river floods and mass movements from glacier fluctuations, the sedimentary record from Russvatnet was analysed for grain-size distribution and minerogenic content, which allowed for discrete mass-movement and river-flood deposits to be recognized. Twenty-two such episodic events were identified; 11 mass movement events and 11 river-flood events. Enhanced river-flood and colluvial activity are observed at 4000-3400, 2900-2500, 2000-1400 and 1000- 500 cal. years BP, suggesting a decreasing trend over the last 4000 years. At c. 2300 cal. years BP a shift in sedimentation regime from a para glacial to a glacially dominated regime was observed, followed by a Neo glacial expansion period after 2300 cal. years BP. In Paper II we examine the possibility for objectively identifying flood deposits in lake sediments and hence construct Holocene flood records that may reveal changes in the long-term frequency of river floods. The method for identifying flood deposits was successfully applied to a high-resolution lake sediment core retrieved from Meringsdalsvatnet in eastern Jotunheimen (61' N 9' E) resulting in a detailed record of river-flood activity covering the last c. 10

  20. Horizontal and low-angle cross-stratifications from volcaniclastic sedimentary sequences: Outburst flood deposits, Numazawa and Ontake volcanoes, Japan

    Science.gov (United States)

    Kataoka, Kyoko

    2017-04-01

    This talk focuses on the formation and preservation of sedimentary structures such as horizontal and low-angle cross-stratifications in volcaniclastic sedimentary (lahar) sequences. The 5 ka outburst flood deposits in the Tadami river catchment, Numazawa volcano, Japan is presented as a first example. The flood, with a peak discharge of > 37,000-58,000 m^3/s from ignimbrite-dammed valley left pumiceous gravelly sediments with meter-sized boulders in the flow path (Kataoka et al., 2008). Up to 30 m thick sequence attributed to the flood formed a low gradient fan of 10 km long and 1.5-3 km wide, covering an area of 18 km2 with a total volume of > 0.5 km3 at the downstream end of the Tadami River. Outcrop observations accompanied with extensive surveys of Ground Penetrating Radar (GPR) along 200 to 500 m lateral and longitudinal transects over the flood fan revealed bedforms of the deposits. The profiles show large internal cross structures with 2-5 m amplitude and 10s m wavelength indicating lateral/downstream accretion in flood fan deposits. Some of them are slightly inclined towards upstream (backsets) which may suggest upstream migration of bedforms. These cross stratifications in the GPR profiles correspond to low-angle cross-stratifications or horizontal stratifications observed in outcrops. In outcrops, the stratified flood deposits mainly comprises rounded pumice pebble and cobble gravel and sand sized mineral grains. Bedding structures include horizontal stratifications and low-angle, low-amplitude, long wavelength cross-stratifications that occasionally climb. Individual 5 cm to decimeters-thick bed sets are commonly inversely graded. The deposits imply 1) high sediment concentration within a flow and 2) aggradation and bedform migration occurred in relation with traction carpet sedimentation. Especially thick traction carpets were probably formed because of 1) high stream power to drive near bed layer deeper and 2) a density contrast among volcaniclastic

  1. Coastal plain and fluvial deposits in the tertiary of central and northern Spain

    NARCIS (Netherlands)

    Moechtar, H.

    1994-01-01

    The Ebro Basin represents purely fluvial deposition with a relatively high, but steady tectonic activity in relation to uplift of the Pyrenees and thrust fault activity. The cyclic pattern in the fluvial deposits can be attributed to Milankovitch related climatological changes. In the Loranca Basin

  2. The artificial and natural isotopes distribution in sedge (Carex L.) biomass from the Yenisei River flood-plain: Adaptation of the sequential elution technique.

    Science.gov (United States)

    Kropacheva, Marya; Melgunov, Mikhail; Makarova, Irina

    2017-02-01

    The study of migration pathways of artificial isotopes in the flood-plain biogeocoenoses, impacted by the nuclear fuel cycle plants, requires determination of isotope speciations in the biomass of higher terrestrial plants. The optimal method for their determination is the sequential elution technique (SET). The technique was originally developed to study atmospheric pollution by metals and has been applied to lichens, terrestrial and aquatic bryophytes. Due to morphological and physiological differences, it was necessary to adapt SET for new objects: coastal macrophytes growing on the banks of the Yenisei flood-plain islands in the near impact zone of Krasnoyarsk Mining and Chemical Combine (KMCC). In the first version of SET, 20 mM Na2EDTA was used as a reagent at the first stage; in the second version of SET, it was 1 M CH3COONH4. Four fractions were extracted. Fraction I included elements from the intercellular space and those connected with the outer side of the cell wall. Fraction II contained intracellular elements; fraction III contained elements firmly bound in the cell wall and associated structures; fraction IV contained insoluble residue. Adaptation of SET has shown that the first stage should be performed immediately after sampling. Separation of fractions III and IV can be neglected, since the output of isotopes into the IV fraction is at the level of error detection. The most adequate version of SET for terrestrial vascular plants is the version using 20 mM Na2EDTA at the first stage. Isotope (90)Sr is most sensitive to the technique changes. Its distribution depends strongly on both the extractant used at stage 1 and duration of the first stage. Distribution of artificial radionuclides in the biomass of terrestrial vascular plants can vary from year to year and depends significantly on the age of the plant.

  3. Ball clay and bentonite deposits of the central and western Gulf of Mexico Coastal Plain, United States

    Science.gov (United States)

    Hosterman, John W.

    1984-01-01

    The Gulf of Mexico Coastal Plain produces approximately 85 percent of the ball clay used in the United States. The best commercial-grade clay deposits are composed of poorly crystalline kaolinite and small amounts of Md illite and (or) smectite. Sand and silt and iron oxide minerals are virtually absent, but quartz is present in the clay-size fraction. The best grade ball clays are found as lenses limited to the Wilcox Group (Paleocene and lower Eocene) and Claiborne Group (middle Eocene). Reserves of ball clay are sufficient for the present, but because of the lenticular nature of the clay bodies, close-spaced drilling, detailed sampling, mineralogic analyses, and ceramic testing are needed to prove future reserves.Approximately 11 percent of the total bentonite produced in the United States comes from the Gulf Coast region. The commercial-grade bentonites are composed primarily of smectite with little or no Md illite and kaolinite. The nonclay impurities are quartz, feldspar, muscovite, biotite, calcite, dolomite, gypsum, and heulandite. Commercial bentonites occur in the Upper Cretaceous formations in Alabama and Mississippi, in Paleocene formations in Mississippi and Tennessee, and in Eocene and Miocene formations in Texas. The demand for low-swelling bentonite of the Gulf Coastal Plain has not increased along with the demand for swelling bentonite; therefore the reserves are adequate.

  4. Quaternary sea level high-stand deposits of the southeast U.S. Atlantic Coastal Plain: Age, distribution, and implications.

    Science.gov (United States)

    Poirier, R. K.; Cronin, T. M.; Ghaleb, B.; Portell, R.; Hillaire-Marcel, C.; Wehmiller, J. F.; Thompson, W. G.; Oches, E. A.; Willard, D. A.; Katz, M. E.

    2015-12-01

    Emerged Quaternary paleo-shorelines and marine deposits provide a more direct way to reconstruct and analyze sea-level variability than methods using oxygen isotope analyses of deep ocean benthic foraminifera. New Uranium-series dates on fossil corals (primarily Astrangia spp. and Septastrea spp.) combined with previously published dates have allowed us to constrain the age, elevation, and geographical distribution of marine sediments deposited in the United States Atlantic Coastal Plain (ACP) from Virginia to Florida during periods of past high relative sea level (SL). We present new dates from deposits (VA/NC: Tabb/Norfolk, Nassawadox, & Omar Formations; SC: Wando, Socastee, & Canepatch Formations; FL: Anastasia, Ft. Thompson, & Bermont Formations) representing interglacial high-stands during Marine Isotope Stages (MIS) 5, 7, 9, and 11. In addition, we incorporate stratigraphic, marine micropaleontologic, and palynologic records with our SL chronology to reconstruct a more complete history of middle-to-late Pleistocene interglacial climates of the ACP. Ultimately, these results will test modeled sea-level fingerprint studies based on various melting scenarios of the Greenland and/or Antarctic ice sheets.

  5. High concentrations and dry deposition of reactive nitrogen species at two sites in the North China Plain

    Energy Technology Data Exchange (ETDEWEB)

    Shen, J.L.; Tang, A.H.; Liu, X.J.; Fangmeier, A.; Goulding, K.T.W.; Zhang, F.S. [China Agricultural University, Beijing (China)

    2009-11-15

    Atmospheric concentrations of major reactive nitrogen (N{sub r}) species were quantified using passive samplers, denuders, and particulate samplers at Dongbeiwang and Quzhou, North China Plain (NCP) in a two-year study. Average concentrations of NH{sub 3}, NO{sub 2}, HNO{sub 3}, pNH{sub 4}{sup +} and pNO{sub 3}{sup -} were 12.0, 12.9, 0.6, 10.3, and 4.7 {mu} g N m{sup -3} across the two sites, showing different seasonal patterns of these N, species. For example, the highest NH{sub 3} concentration occurred in summer while NO{sub 2} concentrations were greater in winter, both of which reflected impacts of N fertilization (summer) and coal-fueled home heating (winter). Based on measured N{sub r} concentrations and their deposition velocities taken from the literature, annual N dry deposition was up to 55 kg N ha{sup -1}. Such high concentrations and deposition rates of N{sub r} species in the NCP indicate very serious air pollution from anthropogenic sources and significant atmospheric N input to crops.

  6. Effects of Varying Shrub Density on Erosion and Deposition During a Large Flood, Rio Puerco, New Mexico

    Science.gov (United States)

    Griffin, E. R.; Friedman, J. M.; Vincent, K. R.

    2010-12-01

    A large flood in August 2006 following saltcedar control efforts along a 12-km segment of the Rio Puerco provided an opportunity to measure the effects of varying shrub density on down-valley flood flow and sediment transport. Post-flood field observations in two 3-km long arroyo segments, one in the sprayed reach and one downstream from the sprayed reach, indicate the density and distribution of woody vegetation had a substantial effect on locations and magnitudes of sediment erosion and deposition. In the reach sprayed with herbicide three years before the flood, in which dense woody stems covered only about 30% of the pre-flood (2005) floodplain, average channel width increased by 63% during the flood. Downstream from the sprayed reach, where both pre-and post-flood shrubs covered 50% of the floodplain, erosion was limited to sites where flood flow through sharp bends undercut the arroyo wall. Flow and suspended sediment transport were computed for two 500-m-long floodplain segments, one in the sprayed reach and one downstream from the sprayed reach. Large volumes of fine-grain sediment (fine to very fine sand and silt) were available for transport during the flood in both reaches. In the reach sprayed with herbicide, dense canopy (dominantly saltcedar; Tamarix spp.) remained only within 10-m-wide linear bands oriented along the present or former channel and in isolated, small shrubs scattered about the floodplain. Downstream from the sprayed reach, adjacent shrub bands were closely spaced, with canopies touching in many areas. Mature saltcedar along the Rio Puerco have rigid, dense stems more than 2 m high, whereas floodplain flow depths during the August 2006 event were on the order of 1 m. Drag on the stems was computed using the average stem density (average stem diameter divided by average stem spacing squared) determined from a large number of measurements along the Rio Puerco, 0.35 m-1 (Friedman and others, unpublished data, 2004). Computations of flow

  7. Assessment of hyporheic zone, flood-plain, soil-gas, soil, and surface-water contamination at the Old Incinerator Area, Fort Gordon, Georgia, 2009-2010

    Science.gov (United States)

    Guimaraes, Wladmir B.; Falls, W. Fred; Caldwell, Andral W.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, assessed the hyporheic zone, flood plain, soil gas, soil, and surface-water for contaminants at the Old Incinerator Area at Fort Gordon, from October 2009 to September 2010. The assessment included the detection of organic contaminants in the hyporheic zone, flood plain, soil gas, and surface water. In addition, the organic contaminant assessment included the analysis of explosives and chemical agents in selected areas. Inorganic contaminants were assessed in soil and surface-water samples. The assessment was conducted to provide environmental contamination data to the U.S. Army at Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Total petroleum hydrocarbons were detected above the method detection level in all 13 samplers deployed in the hyporheic zone and flood plain of an unnamed tributary to Spirit Creek. The combined concentrations of benzene, toluene, ethylbenzene, and total xylene were detected at 3 of the 13 samplers. Other organic compounds detected in one sampler included octane and trichloroethylene. In the passive soil-gas survey, 28 of the 60 samplers detected total petroleum hydrocarbons above the method detection level. Additionally, 11 of the 60 samplers detected the combined masses of benzene, toluene, ethylbenzene, and total xylene above the method detection level. Other compounds detected above the method detection level in the passive soil-gas survey included octane, trimethylbenzene, perchlorethylene, and chloroform. Subsequent to the passive soil-gas survey, six areas determined to have relatively high contaminant mass were selected, and soil-gas samplers were deployed, collected, and analyzed for explosives and chemical agents. No explosives or chemical agents were detected above

  8. Influence of vegetation on spatial patterns of sediment deposition in deltaic islands during flood

    Science.gov (United States)

    Nardin, W.; Edmonds, D. A.; Fagherazzi, S.

    2016-07-01

    River deltas are shaped by the interaction between flow and sediment transport. This morphodynamic interaction is potentially affected by freshwater marsh vegetation (e.g. Sagittaria spp.and Typha spp. in the Mississippi delta, USA) on the exposed surfaces of emergent deltaic islands. The vulnerability of deltaic islands is a result of external forces like large storms, sea level rise, and trapping of sediment in upstream reservoirs. These factors can strongly determine the evolution of the deltaic system by influencing the coupling between vegetation dynamics and morphology. In the last few years, models have been developed to describe the dynamics of salt marsh geomorphology coupled with vegetation growth while the effect of freshwater vegetation on deltaic islands and marshes remains unexplored. Here we use a numerical flow and sediment transport model to determine how vegetation affects the spatial distribution of sediment transport and deposition on deltaic surfaces during flood. Our modeling results show that, for an intermediate value of relative vegetation height and density, sedimentation rate increases at the head of the delta. On the other hand, large values of relative vegetation height and density promote more sedimentation at the delta shoreline. A logical extension of our results is that over time intermediate values of relative vegetation height and density will create a steeper-sloped delta due to sediment trapping at the delta head, whereas relatively taller vegetation will create a larger, but flatter delta due to sediment deposition at the shoreline. This suggests intermediate relative vegetation height and density may create more resilient deltas with higher average elevations.

  9. A Study of the Adsorption of Molecular Deposition Filming Flooding Agent MD-1 on Quartz Sand

    Institute of Scientific and Technical Information of China (English)

    GaoManglai; LiuYong; MengXiuxia; WangJianshe

    2004-01-01

    Molecular deposition filming flooding (MDFF) is a novel oil recovery technique based on the thermopositive monolayer electrostatic adsorption of the MDFF agent on different interfaces within reservoir systems. In this paper, the adsorption property of the MDFF agent, MD-I, on quartz sand has been studied through adsorption experiments at different pH and temperatures. Experimental data are also analyzed kinetically and thermodynamically. The results show that the adsorption of MD-I on quartz sand takes place mainly because of electrostatic interactions, which corresponds to adsorption that increases with pH. Kinetic analyses show that at a higher pH the activation energy for adsorption gets lower and, therefore, the adsorption becomes quicker for MD-1 on quartz sand. Thermodynamic analyses show that pH plays an important role in the adsorption of MD-1 on quartz sand. At a higher pH, more negative surface charges result in the increase of electrostatic interactions between MD-1 and quartz sand. Therefore, the saturated adsorption amount increases and more adsorption heat will be released.

  10. Paleotsunami Inundation of a Beach Ridge Plain: Cobble Ridge Overtopping and Interridge Valley Flooding in Seaside, Oregon, USA

    Directory of Open Access Journals (Sweden)

    Curt D. Peterson

    2010-01-01

    Full Text Available The Seaside beach ridge plain was inundated by six paleotsunamis during the last ~2500 years. Large runups (adjusted >10 m in height overtopped seawardmost cobble beach ridges (7 m elevation at ~1.3 and ~2.6 ka before present. Smaller paleotsunami (6–8 m in height likely entered the beach plain interior (4-5 m elevation through the paleo-Necanicum bay mouth. The AD 1700 Cascadia paleotsunami had a modest runup (6-7 m height, yet it locally inundated to 1.5 km landward distance. Bed shear stresses (100–3,300 dyne cm−2 are estimated for paleotsunami surges (0.5–2 m depths that flowed down slopes (0.002–0.017 gradient on the landward side of the cobble beach ridges. Critical entrainment shear stresses of 1,130–1,260 dyne cm−2 were needed to dislodge the largest clasts (26–32 cm diameter in paleotsunami coulees that were cut (100–200 m width into the landward side of the cobble ridges.

  11. Spatio-temporal variations and influencing factors of polycyclic aromatic hydrocarbons in atmospheric bulk deposition along a plain-mountain transect in western China

    Science.gov (United States)

    Xing, Xinli; Zhang, Yuan; Yang, Dan; Zhang, Jiaquan; Chen, Wei; Wu, Chenxi; Liu, Hongxia; Qi, Shihua

    2016-08-01

    Ten atmospheric bulk deposition (the sum of wet and dry deposition) samplers for polycyclic aromatic hydrocarbons (PAHs) were deployed at a plain-mountain transect (namely PMT transect, from Daying to Qingping) in Chengdu Plain, West China from June 2007 to June 2008 in four consecutive seasons (about every three months). The bulk deposition fluxes of ∑15-PAHs ranged from 169.19 μg m-2 yr-1 to 978.58 μg m-2 yr-1 with geometric mean of 354.22 μg m-2 yr-1. The most prevalent PAHs were 4-ring (39.65%) and 3-ring (35.56%) PAHs. The flux values were comparable to those in rural areas. Higher fluxes of total PAHs were observed in the middle of PMT transect (SL, YX and JY, which were more urbanized than other sites). The seasonal deposition fluxes in the sampling profile indicated seasonality of the contaminant source was an important factor in controlling deposition fluxes. PAHs bulk deposition was negatively correlated with meteorological parameters (temperature, wind speed, humidity, and precipitation). No significant correlations between soil concentrations and atmospheric deposition were found along this transect. PAHs in soil samples had combined sources of coal, wood and petroleum combustion, while a simple source of coal, wood and grass combustion for bulk deposition. There were significant positive correlation relationship (p region of China or farther regions via long-range transport.

  12. Paleoenvironmental analyses of an organic deposit from an erosional landscape remnant, Arctic Coastal Plain of Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Eisner, W R; Bockheim, J G; Hinkel, K M; Brown, T A; Nelson, F E; Peterson, K M; Jones, B M

    2005-01-02

    The dominant landscape process on the Arctic Coastal Plain of northern Alaska is the formation and drainage of thaw lakes. Lakes and drained thaw lake basins account for approximately 75% of the modern surface expression of the Barrow Peninsula. The thaw lake cycle usually obliterates lacustrine or peat sediments from previous cycles which could otherwise be used for paleoecological reconstruction of long-term landscape and vegetation changes. Several possible erosional remnants of a former topographic surface that predates the formation of the thaw lakes have been tentatively identified. These remnants are characterized by a higher elevation, a thick organic layer with very high ground ice content in the upper permafrost, and a plant community somewhat atypical of the region. Ten soil cores were collected from one site, and one core was intensively sampled for soil organic carbon content, pollen analysis, and {sup 14}C dating. The lowest level of the organic sediments represents the earliest phase of plant growth and dates to ca. 9000 cal BP. Palynological evidence indicates the presence of mesic shrub tundra (including sedge, birch, willow, and heath vegetation); and microfossil indicators point to wetter eutrophic conditions during this period. Carbon accumulation was rapid due to high net primary productivity in a relatively nutrient-rich environment. These results are interpreted as the local response to ameliorating climate during the early Holocene. The middle Holocene portion of the record contains an unconformity, indicating that between 8200 and 4200 cal BP sediments were eroded from the site, presumably in response to wind activity during a drier period centered around 4500 cal BP. The modern vegetation community of the erosional remnant was established after 4200 cal BP, and peat growth resumed. During the late Holocene, carbon accumulation rates were greatly reduced in response to the combined effects of declining productivity associated with climatic

  13. Effects of Mineral N and P Fertilizers on Yield and Yield Components of Flooded Lowland Rice on Vertisols of Fogera Plain, Ethiopia

    Directory of Open Access Journals (Sweden)

    Heluf Gebrekidan

    2006-10-01

    Full Text Available Despite its very recent history of cultivation in Ethiopia, rice is one of the potential grain crops that could contribute to the efforts for the realization of food security in the country. However, the scientific information available with regards to the response of flooded rice to N and P fertilizers for its optimum production on Vertisols of Fogera Plain is very limited. Therefore, a field experiment was conducted on Vertisols of Fogera plain, northern Ethiopia to study the yield and yield components response of rice and to establish the optimum N and P fertilizer levels required for improved grain yield of flooded rice. Six levels of N (0, 30, 60, 90, 120 and 150 kg ha−1 and five levels of P (0, 13.2, 26.4, 39.6 and 52.8 kg ha−1 laid down in a randomized complete block design with four replications were used as treatments. Nitrogen was applied in two equal splits (50% basal and 50% at maximum tillering as urea and the entire dose of P was applied basal as triple super phosphate at sowing. The main effects of N and P fertilizer levels showed significant differences (P ≤ 0.01 for all yield and yield components studied. The effects of N by P interaction were significant only for grain yield (P ≤ 0.05, number of panicles per m2 (P ≤ 0.01, number of spikelets per panicle (P ≤ 0.05 and plant height (P ≤ 0.01 among the different yield and yield components studied. Application of N and P significantly (P ≤ 0.01 increased grain yield of rice up to the levels of 60 kg N and 13.2 kg P ha−1. However, maximum grain yield (4282 kg ha−1 was obtained with the combined application of 60 kg N and 13.2 kg P ha−1, and the yield advantage over the control was 38.49% (1190 kg ha−1. Moreover, application of both N and P fertilizers have increased the magnitudes of the important yield attributes including number of panicles per m2, number of spikelets per panicle, panicle length, dry matter accumulation, straw yield and plant height

  14. Discussion of "Atmospheric deposition as an important nitrogen load to a typical agro-ecosystem in the Huang-Huai-Hai Plain" by Huang et al. (2016)

    Science.gov (United States)

    Pan, Yuepeng; Xu, Wen; Wentworth, Gregory R.; Tian, Shili

    2017-03-01

    In a recent publication of Atmospheric Environment, Huang et al. (2016) reported nitrogen (N) deposition estimates using the water surrogate surface method. This method may be suitable to evaluate the atmospheric N input to a body of water, wetland or paddy fields rather than dry crop land without sustained waterlogged conditions. Such a method may also result in the potential underestimation of both dry and wet N deposition due to the release of ammonia (NH3) from water evaporation and/or N loss from biological activities, and hence bias the relative contribution of dry deposition to total deposition. Besides the uncertainties regarding the magnitude and pathways of N deposition, the statement by Huang et al. (2016) that "nitrate was the dominant species in N deposition even in cropland" is also questionable. We suggest that reduced species dominate the N deposition in Huang-Huai-Hai Plain (i.e., North China Plain) even in urban and industrial regions due to the abundance of NH3.

  15. Influence of deposition of fine plant debris in river floodplain shrubs on flood flow conditions - The Warta River case study

    Science.gov (United States)

    Mazur, Robert; Kałuża, Tomasz; Chmist, Joanna; Walczak, Natalia; Laks, Ireneusz; Strzeliński, Paweł

    2016-08-01

    This paper presents problems caused by organic material transported by flowing water. This material is usually referred to as plant debris or organic debris. Its composition depends on the characteristic of the watercourse. For lowland rivers, the share of the so-called small organic matter in plant debris is considerable. This includes both various parts of water plants and floodplain vegetation (leaves, stems, blades of grass, twigs, etc.). During floods, larger woody debris poses a significant risk to bridges or other water engineering structures. It may cause river jams and may lead to damming of the flowing water. This, in turn, affects flood safety and increases flood risk in river valleys, both directly and indirectly. The importance of fine plant debris for the phenomenon being studied comes down to the hydrodynamic aspect (plant elements carried by water end up on trees and shrubs, increase hydraulic flow resistance and contribute to the nature of flow through vegetated areas changed from micro-to macro-structural). The key part of the research problem under analysis was to determine qualitative and quantitative debris parameters and to establish the relationship between the type of debris and the type of land use of river valleys (crop fields, meadows and forested river sections). Another problem was to identify parameters of plant debris for various flow conditions (e.g. for low, medium and flood flows). The research also included an analysis of the materials deposited on the structure of shrubs under flood flow conditions during the 2010 flood on the Warta River.

  16. Sedimentary architecture and depositional evolution of the Quaternary coastal plain of Maricá, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    André Luiz Carvalho da Silva

    Full Text Available The coastal geomorphology of Maricá (Rio de Janeiro state is characterized by a large lagoon and by two sandy barriers that confine a series of small isolated chain-like lagoons. Data collected from ground-penetrating radar and boreholes from the central coastal plain of Maricá provided information on the sedimentary architecture and evolution of this area in the Quaternary. Six lithological units were identified comprising three depositional sequences limited by erosional surfaces, related to barrier-lagoon systems that migrated onshore, offshore, and longshore, giving rise to a sedimentary deposit 25 m thick or more. The data reveal a retrograding barrier overlying a basal mud unit which rests in unconformity upon Precambrian basement, thus characterizing an important Pleistocene transgression. A second Pleistocene barrier of 45,000 cal years BP migrated over a lagoonal mud unit (48,000-45,000 cal years BP reaching over the previous barrier. A progradational phase followed due to a fall of sea level. A long interval of erosion of the barrier created an unconformity that represents the Pleistocene-Holocene boundary. A beachrock in nearby Itaipuaçu, 100 m offshore from the present-day beach, dated as 8,500 cal years BP marks the onset of Holocene sedimentation due to gradually rising sea level, which continued until at about 5,000 years ago. This promoted the retrogradation of the barrier-lagoon system. A brief episode of progradation is observed as a series of paleobeach scarps. Today's rising sea level is causing the retrogradation of the barrier.

  17. Task 50 - deposition of lignites in the Fort Union Group and related strata of the northern Great Plains

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, J.H.; Roth, B.; Kihm, A.J.

    1997-08-11

    Late Cretaceous, Paleocene, and early Eocene geologic and paleontologic studies were undertaken in western North Dakota, eastern and south-central Montana, and northwestern and northeastern Wyoming. These study areas comprise the Williston, Bighorn, and Powder River Basins, all of which contain significant lignite resources. Research was undertaken in these basins because they have the best geologic sections and fossil record for the development of a chronostratigraphic (time-rock) framework for the correlation of lignite beds and other economic resources. A thorough understanding of the precise geologic age of the deposition of sediments permits a powerful means of interpreting the record of geologic events across the northern Great Plains. Such an understanding allows for rigorous interpretation of paleoenviromnents and estimates of resource potential and quality in this area of economically significant deposits. This work is part of ongoing research to document change in the composition of molluscan fossil faunas to provide a paleoenvironmentally sensitive independent means of interpreting time intervals of brief duration during the Late Cretaceous, Paleocene, and Eocene. This study focuses on the record of mollusks and, to a lesser extent, mammals in the (1) Hell Creek-Tullock Formations, which include the Cretaceous-Paleocene boundary, in the western portion of the Williston Basin, Montana; (2) uppermost Cretaceous, Paleocene, and lowermost Eocene strata in western North Dakota, which -includes the last interior seaway in North Dakota; (3) upper Paleocene and lowermost Eocene of the northern portion of the Bighorn Basin of south-central Montana and northwestern Wyoming; and (4) Powder River Basin of northeastern Wyoming and southeastern Montana. The geologic record provides different physical and paleontological information to aid in interpreting the geologic record through the study interval.

  18. Dark gray soils on two-layered deposits in the north of Tambov Plain: Agroecology, properties, and diagnostics

    Science.gov (United States)

    Zaidelman, F. R.; Nikiforova, A. S.; Stepantsova, L. V.; Volokhina, V. P.

    2012-05-01

    Dark gray soils in the Tambov Plain are developed from the light-textured glaciofluvial deposits underlain by the calcareous loam. Their morphology, water regime, and productivity are determined by the depth of the slightly permeable calcareous loamy layer, relief, and the degree of gleyzation. The light texture of the upper layer is responsible for its weak structure, high density, the low content of productive moisture, and the low water-holding capacity. If the calcareous loam is at a depth of 100-130 cm, dark gray soils are formed; if it lies at a depth of 40-70 cm, temporary perched water appears in the profile, and dark gray contact-gleyed soils are formed. Their characteristic pedofeatures are skeletans in the upper layers, calcareous nodules in the loamy clay layer, and iron nodules in the podzolized humus and podzolic horizons. The appearance of Fe-Mn concretions is related to gleyzation. The high yield of winter cereals is shown to be produced on the dark gray soils; the yields of spring crops are less stable. Spring cereals should not be grown on the contact-gleyed dark gray soils.

  19. Status of organochlorine pesticides in the drinking water well-field located in the Delhi region of the flood plains of river Yamuna

    Directory of Open Access Journals (Sweden)

    P. K. Mutiyar

    2011-08-01

    Full Text Available This study presents the occurrence of pesticides in a well-field located in Yamuna flood plain of Delhi region. Ground water sampling campaigns were carried out during pre-monsoon and post-monsoon periods covering 21 bore-wells and 5 Ranney wells. Major 17 organochlorine pesticides (OCP's along with other water quality parameters were monitored during this period. Pesticide concentrations were determined using GC- ECD, while GC-MS was used for confirmatory purposes. OCP's groups like ∑HCH, ∑DDT, endosulfan and aldrin were observed in this well-field. Concentration of OCPs from Ranney wells exceeded the limit (1 μg l−1 prescribed by the Bureau of Indian Standards (BIS in pre-monsoon season, though OCP levels in bore wells were within BIS limits. However, these levels were very close to the World Health Organisation (WHO and European Union (EU limit of for pesticides (0.5 μg l−1 in many samples. Bore well produced better quality water compared to the water from Ranney wells. Although, the level of OCP's was slightly lower than prescribed limit of national regulatory agency but such low doses may cause long-term damage to human populations if such water is consumed for longer durations. At low doses OCP's acts as endocrine disrupting agent and cause metabolic disorders in local population.

  20. Lithofacies and particle-size characteristics of late Quaternary floodplain deposits along the middle reaches of the Ganga river, central Ganga plain, India

    Science.gov (United States)

    Kanhaiya, S.; Singh, B. P.; Tripathi, Maya; Sahu, Sagrika; Tiwari, Veena

    2017-05-01

    Floodplains are flat areas lining both sides of most rivers. They are commonly inundated during high flood events and are important sites of biodiversity and human occupation and cultivation. Big city centers such as Kanpur, Allahabad, Mirzapur and Varanasi are situated on the bank of the Ganga river in central Ganga plain, India. Cliffed embankments occur on the left side of the Ganga river around the village of Jhusi, Allahabad district and Adalpura, Mirzapur district, and on the right side around the town of Jajmau, Kanpur district, around the village of Sirsa, Allahabad district, around the town of Ramnagar, Varanasi district and the village of Tanda, Chandauli district. These cliff sections were studied to determine facies types and grain-size variations along and across the cliff sections in order to elucidate the mechanism of particle transportation and sedimentation on the floodplains. It was found that the majority of the facies are composed of extremely silty and very silty slightly sandy mud, and extremely silty and very silty sandy mud, a few consisting of slightly clayey silt. Both groundwater horizons and intercalated pedogenic calcretes in the muddy facies suggest pedogenesis under arid to semiarid climatic conditions during their development. Grain-size analyses show that mean particle size ranges from 4.23-6.53 phi (coarse to fine silt). Sorting (standard deviation) shows a range of 1.57-2.94 phi, indicating that all the samples are poorly to very poorly sorted. Skewness ranges from 0.09-0.88 (near-symmetrical to very fine skewed). Kurtosis varies from 0.75-1.54, with a few exceptions indicating mesokurtic to very leptokurtic size distributions. Plots of mean grain size vs. sorting suggest that sedimentation took place in a quiet fluvial environment in the course of numerous discharge episodes. Channel and floodplain deposits of the Ganga river are clearly distinguished in these plots. Furthermore, a plot of the coarsest percentile against the

  1. Spatio-temporal variability of CH4 fluxes and environmental drivers on a modern flood plain of the Siberian Lena River Delta

    Science.gov (United States)

    Rößger, Norman; Wille, Christian; Kutzbach, Lars

    2016-04-01

    In the course of the amplified climate change in the Arctic, methane emissions may considerably increase due to more suitable production conditions comprising enhanced temperatures, greater abundance of moisture and increased availability of the carbon stock to microorganisms. Since methane exhibits a much higher global warming potential than carbon dioxide, a comprehensive understanding of its spatio-temporal dynamics as well as its key controls is of great importance. We study the carbon turnover with a focus on methane on the modern flood plain of Samoylov Island in the Lena River Delta (72°22'N, 126°28'E) using the eddy covariance technique. The heterogeneous area around the flux tower (footprint) is characterised by annual flooding, a variety of non-cryoturbated permafrost-affected soils with different degrees of organic matter accumulation, a tundra vegetation dominated by shrubs and sedges and a slightly undulating relief forming elevated, well drained areas und wet, partially inundated depressions. The measurements ran between June 2014 and September 2015 when methane fluxes were determined using a LICOR 7700 open-path CH4 analyser. The main emissions occurred between June and September determined by spring thaw and refreezing in autumn. The highest methane emissions took place in early August reaching up to 0.03 μmol m-2 s-1. Over the season, the mean methane flux amounted to 0.012 μmol m-2 s-1. This average is based on a large variability of methane fluxes which is to be attributed to the complexity of the footprint. The methane sources are unevenly distributed; thus, the capture of methane fluxes is highly dependent on atmospheric conditions such as stratification and wind direction. Explaining the variability in methane fluxes is based on three modelling approaches: step-wise regression, neural network and deterministic modelling using exponential relationships for flux drivers. For the identification of suitable flux drivers, a comprehensive data

  2. Vertical profile of PCDD/Fs, dioxin-like PCBs, other PCBs, PAHs, chlorobenzenes, DDX, HCHs, organotin compounds and chlorinated ethers in dated sediment/soil cores from flood-plains of the river Elbe, Germany.

    Science.gov (United States)

    Götz, Rainer; Bauer, Otto-Heinrich; Friesel, Peter; Herrmann, Thomas; Jantzen, Eckard; Kutzke, Manfred; Lauer, Raimund; Paepke, Olaf; Roch, Klaus; Rohweder, Udo; Schwartz, René; Sievers, Susanne; Stachel, Burkhard

    2007-03-01

    Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and other organic micropollutants were determined in dated sediment/soil cores collected from the flood-plain of the river Elbe near Pevestorf (PT), approximately 125 km upstream of Hamburg, and Heuckenlock (HL) in southeast of Hamburg. Concentrations of PCDD/Fs peaked sharply at PT in the 1950s and at HL at the end of the 1940s. Cluster analyses provide evidence that the region of Bitterfeld-Wolfen (about 350-400 km upstream of Hamburg) could be the source of the PCDD/F contamination existing in the cores PT and HL since the 1940s. Obviously it is caused by sediments of the river Elbe of a similar composition. Whereas the PCDD/Fs, HCHs (hexacyclohexane isomers), DDX (DDT, DDD, DDE), and tetrachlorinated ethers in PT and HL presumably originated predominantly from the Bitterfeld-Wolfen region, organotin compounds in HL and dichlorinated haloethers in HL during the 1940s and 1950s can probably largely be attributed to emissions from the Hamburg region. Although they are separated by a large distance, in both sediment cores PT and HL concentrations and composition patterns of most organic micropollutants analyzed widely match. Inductively it can be concluded that similar contaminations will be found in many of the river bank soils between the Bitterfeld-Wolfen region and Hamburg. Excavation of top soils may uncover highly contaminated materials. Since the dated sediment cores show the variation in contaminants in the Elbe sediments over a defined time period, it is possible to make an approximate assessment of the actual degree of contamination to be expected in areas where in previous decades contaminated dredged sediments from the Elbe and from the Port of Hamburg have been deposited on land and used for building plots or for agricultural purposes.

  3. Assessing hyporheic zone dynamics in two alluvial flood plains of the Southern Alps using water temperature and tracers

    Directory of Open Access Journals (Sweden)

    E. Hoehn

    2006-03-01

    Full Text Available Water temperature can be used as a tracer for the interaction between river water and groundwater, interpreting time shifts in temperature signals as retarded travel times. The water temperature fluctuates on different time scales, the most pronounced of which are the seasonal and diurnal ones. While seasonal fluctuations can be found in any type of shallow groundwater, high-frequency components are more typical for freshly infiltrated river water, or hyporheic groundwater, and are thus better suited for evaluating the travel time of the youngest groundwater component in alluvial aquifer systems. We present temperature time series collected at two sites in the alpine floodplain aquifers of the river Brenno in Southern Switzerland. At the first site, we determine apparent travel times of temperature for both the seasonal and high-frequency components of the temperature signals in several wells. The seasonal signal appears to travel more slowly, indicating a mixture of older and younger groundwater components, which is confirmed by sulphate measurements. The travel times of the high-frequency component qualitatively agree with the groundwater age derived from radon concentrations, which exclusively reflects young water components. Directly after minor floods, the amplitude of temperature fluctuations in an observation well nearby the river is the highest. Within a week, the riverbed is being clogged, leading to stronger attenuation of the temperature fluctuations in the observation well. At the second site, very fast infiltration to depths of 1.9m under the riverbed could be inferred from the time shift of the diurnal temperature signal.

  4. Quantifying erosion and deposition patterns using airborne LiDAR following the 2012 High Park Fire and 2013 Colorado Flood

    Science.gov (United States)

    Brogan, D. J.; Nelson, P. A.; MacDonald, L. H.

    2015-12-01

    Quantifying and predicting geomorphic change over large spatial scales is increasingly feasible and of growing interest as repeat high resolution topography becomes available. We began detailed field studies of channel geomorphic change using RTK-GPS in two 15 km2 watersheds following the 2012 High Park Fire; the watersheds were then subjected to a several-hundred year flood in September 2013. During this time a series of airborne LiDAR datasets were collected, and the objectives of this study were to: 1) determine and compare the spatial variability in channel and valley erosion and deposition over time from the LiDAR; and 2) determine if the observed changes can be predicted from channel and valley bottom characteristics. Data quality issues in the initial LiDAR required us to rotate and translate flight lines in order to co-register ground-classified point clouds between successive datasets; uncertainty was then estimated using our RTK-GPS field measurements. Topographic changes were calculated using the Multiscale Model to Model Cloud Comparison (M3C2) algorithm. Results indicate that the 2013 flood mobilized much more sediment than was mobilized due to the fire alone; unfortunately the uncertainty in differencing is still frequently greater than the observed changes, especially within transfer reaches. Valley expansion and constriction are major controls on spatial patterns of erosion and deposition, suggesting that topographic metrics such as longitudinal distributions of channel slope and valley confinement may provide quasi-physically based estimates of sediment deposition and delivery potential.

  5. Fine-grained sediment gravity flow deposits induced by flood and lake slope failure events: examples of lacustrine varved sediments in Japan

    Science.gov (United States)

    Ishihara, Yoshiro; Sasaki, Yasunori; Sasaki, Hana; Onishi, Yuri

    2016-04-01

    Fine-grained sediment gravity flow deposits induced by flood and lake slope failure events are frequently intercalated in lacustrine successions. When sediment gravity flow deposits are present in varved sediments, it is suggested that they provide valuable information about sediment gravity flows, because they can easily trace laterally and can give the magnitude of erosion and recurrence interval of events. In addition, because large sedimentary bodies of stacked sediment gravity flow deposits in varved sediments of a calm lake are not suggested, a relatively simple depositional environment is expected. In the present study, we analysed sedimentary facies of sediment gravity flow deposits in varved lacustrine diatomites in the Middle Pleistocene Hiruzenbara and Miyajima formations in Japan, and concluded a depositional model of the lacustrine sediment gravity flow deposits. Varved diatomites: The Hiruzenbara Fm., a dammed lake fill as foots of Hiruzen Volcanos, is deposited during an interglacial period during MIS12 to 15. Varves of ca. 8000 yr were measured in a 20 m intercalating flood and lake slope failure-induced sediment gravity flow deposits. The Miyajima Fm., distributed in a paleo-caldera lake in NE Japan, includes many sediment gravity flow deposits possibly originated from fandeltas around the lake. These formations have differences in their depositional setting; the Hiruzebara Fm. was deposited in a large lake basin, whereas the Miyajima Fm. was deposited in a relatively small basin. Because of the depositional setting, intercalation of volcaniclastics is dominant in the Miyajima Fm. Lacustrine sediment gravity flow deposits: Sediment gravity flow deposits in both formations can be classified into flood- and lake slope failure-induced types based on the sedimentary facies. Composites of the both types are also found. Flood-induced types comprise fine-grained silts dominated by carbonaceous fragments, whereas lake slope failure-induced types are

  6. Ground-water quality in Quaternary deposits of the central High Plains aquifer, south-central Kansas, 1999

    Science.gov (United States)

    Pope, Larry M.; Bruce, Breton W.; Hansen, Cristi V.

    2001-01-01

    Water samples from 20 randomly selected domestic water-supply wells completed in the Quaternary deposits of south-central Kansas were collected as part of the High Plains Regional Ground-Water Study conducted by the U.S. Geological Survey's National Water-Quality Assessment Program. The samples were analyzed for about 170 water-quality constituents that included physical properties, dissolved solids and major ions, nutrients and dissolved organic carbon, trace elements, pesticides, volatile organic compounds, and radon. The purpose of this study was to provide a broad overview of ground-water quality in a major geologic subunit of the High Plains aquifer. Water from five wells (25 percent) exceeded the 500-milligrams-per-liter of dissolved solids Secondary Maximum Contaminant Level for drinking water. The Secondary Maximum Contaminant Levels of 250 milligrams per liter for chloride and sulfate were exceeded in water from one well each. The source of these dissolved solids was probably natural processes. Concentrations of most nutrients in water from the sampled wells were small, with the exception of nitrate. Water from 15 percent of the sampled wells had concentrations of nitrate greater than the 10-milligram-per-liter Maximum Contaminant Level for drinking water. Water from 80 percent of the sampled wells showed nitrate enrichment (concentrations greater than 2.0 milligrams per liter), which is more than what might be expected for natural background concentrations. This enrichment may be the result of synthetic fertilizer applications, the addition of soil amendment (manure) on cropland, or livestock production. Most trace elements in water from the sampled wells were detected only in small concentrations, and few exceeded respective water-quality standards. Only arsenic was detected in one well sample at a concentration (240 micrograms per liter) that exceeded its proposed Maximum Contaminant Level (5.0 micrograms per liter). Additionally, one concentration of

  7. An ice-contact rhythmite (turbidite) succession deposited during the November 1996 catastrophic outburst flood (jökulhlaup), Skeiðarárjökull, Iceland

    Science.gov (United States)

    Russell, Andrew J.; Knudsen, Óskar

    1999-08-01

    This paper presents new evidence of coarse-grained deposition from a turbulent suspension within a low-energy `slack-water' location during a recent well-documented, volcanically related, high-magnitude glacier outburst flood or jökulhlaup, Skeiðarárjökull, Iceland. This study uses established spatial and temporal constraints on processes observed during the November 1996 jökulhlaup to interpret resultant flood sediments. Coarse-grained sediments were deposited within flood slack-water conditions from suspension load by repeated turbulent flow pulses with durations of seconds-minutes. Depositional processes are thought to be analogous to turbidity currents. A minimum thickness of 15 m of rhythmites record suspended sediment dynamics at a conduit mouth during the late rising and early falling stages of the jökulhlaup. The morphology and sedimentology of deposits in a large ice-walled chamber are consistent with previous models proposed for bar deposition during cataclysmic floods. Flood flows within subglacial conduits and ice-walled open channels were sufficiently powerful to carry material up to boulder size in suspension. Macro-turbulent flows carried huge quantities of suspended sediment to high levels within the main outlet channel. High-frequency, short-duration flow pulses entering a complex ice-walled channel geometry generated highly unsteady and non-uniform flows capable of both erosional and depositional work. This study lends support to the deposition of multiple rhythmites per flood under main flow slack-water conditions. Identification of high-magnitude jökulhlaups in the ice-marginal sedimentary record will depend on the identification and correct interpretation of feeder channel and slack-water turbidite sediments. The results described here may also have application to rhythmic deposits formed by large turbulent flows in other environmental settings.

  8. Assessment of reproductive capacity of estuarine plants Butomus umbellatus L. and Alisma plantago-aquatica L. from radioactively contaminated flood plains

    Energy Technology Data Exchange (ETDEWEB)

    Kaneva, A.V.; Majstrenko, T.A.; Rachkova, N.G.; Belykh, E.S.; Zainullin, V.G. [Institute of Biology, Komi Scientific Center, Ural Division of RAS, Syktyvkar, 167982 (Russian Federation)

    2014-07-01

    It is known that the vegetation, along with the climatic conditions and soil type, is one of the key components of terrestrial ecosystems. They are also first to respond to the substrate contamination with radionuclides, metals and organic substances. Biological effects observed in natural plant populations are associated with both presence of mobile compounds of pollutants in abiotic components of the ecosystem and their role in the metabolism of the plant. The goal of the study was to assess the impact of water and sediment contamination with artificial radionuclides and toxic non-radioactive compounds, on the reproductive capacity of estuarial plants using seed germination. Contaminated sites are located in flood plain of the Techa River (Chelabinsk region, Russia) between Muslumovo and Brodokalmak settlements. Radioactive contamination of the territory resulted from increased specific activities of {sup 137}Cs and {sup 90}Sr in water and sediments due to the accidents on the Mayak Production Association. Reference sites were chosen in the flood plains of Brusianka and Sysert' rivers (Sverdlovsk region, Russia). Reference sites are located out of the Eastern Ural Radioactive Trace. Seeds of Butomus umbellatus L. and Alisma plantago-aquatica L., which are common estuarine plant communities in this area, were collected. Specific activities of dose-forming radionuclides in the Techa river water vary from 120 up to 200 mBq/l for {sup 137}Cs and from 26 up to 45 mBq/l for {sup 90}Sr; and in sediments 720-10150 Bq/kg and 600-1500 Bq/kg for {sup 137}Cs and {sup 90}Sr correspondingly. Specific activities of {sup 137}Cs and {sup 90}Sr in water and sediments of both reference rivers do not exceed global fallout levels. B. umbellatus seeds germination was low for plant populations of both reference and contaminated sites. However, a significant (p<0.01) difference was found - the value was higher for reference populations (17.4 ±3.5 %) as compared with the ones from

  9. Hydrological characteristics and flood plain vegetation of human impacted wetlands: A case study from Okhla Bird Sanctuary, National Capital Region, India

    Directory of Open Access Journals (Sweden)

    Upma Manral

    2012-12-01

    Full Text Available Yamuna River has been subjected to severe anthropogenic pressures such as water abstraction, discharge of wastewater, development activities on river floodplains, deforestation in the river basin resulting in reduced flow, loss of habitat, deterioration of water quality and loss of biological diversity. We studied hydrological characteristics such as river flow, water depth and quality and floodplain vegetation characteristics of Okhla Bird Sanctuary (OBS, a human modified floodplain wetland formed due to the construction of Okhla barrage across the Yamuna River in National Capital Region (NCR, on the Delhi-Uttar Pradesh border. The flow data for Yamuna was collected from Delhi Jal board and irrigation department of Uttar Pradesh. Study indicates reduced flow in the river downstream Wazirabad with no release of water in the summers of 2006 and 2010. For bathymetry, GARMIN 160 C Fish Finder was used after dividing study area into 50 m x 50 m grids. About 65% area had depth less than 2 m indicating more of shallower areas. Results for water quality analysis show a dissolved oxygen level at 1.6 ± 0.84 mgl-1, Biological and Chemical Oxygen demand at 16.72 ± 4.28 mgl-1 and 39.8 ± 7.71 mgl-1 respectively, indicating a high organic load in the river. The Sanctuary is facing serious threats from the rapid proliferation of Typha angustifolia and Eichhornia crassipes which were dominant species in shallow water and open water habitats, respectively. Thus, the remaining Yamuna river flood plain in the NCR, Delhi should be declared as ecologically sensitive area and appropriate measures should be taken to maintain its integrity.

  10. Assessing land-use changes driven by river dynamics in chronically flood affected Upper Brahmaputra plains, India, using RS-GIS techniques

    Directory of Open Access Journals (Sweden)

    Nabajit Hazarika

    2015-06-01

    Full Text Available This work documents land-use changes driven by river dynamics along two tributaries in the chronically flood affected Upper Brahmaputra floodplain which supports a population of more than half a million. Planform changes for a period of 40 years are documented using topographical map and Landsat data, and the associated land-use change is assessed by utilising hybrid classification in GIS environment. Quantification of bankline migration shows that the river courses are unstable. A reversal in the rate of erosion and deposition is also observed. Hybrid classification of Landsat images yielded a higher level of accuracy as evident from the confusion matrixes. Overall, the accuracy of land-use classification ranged between 88.5% and 96.25%. Land-use change shows that there is an increase in settlement and agriculture and a decrease in the grassland. The area affected by erosion–deposition and river migration comprises primarily of the agricultural land. Effect of river dynamics on settlements is also evident. Loss of agricultural land and homestead led to the loss of livelihood and internal migration in the floodplains. The observed pattern of river dynamics and the consequent land-use change in the recent decades have thrown newer environmental challenges at a pace and magnitude way beyond the coping capabilities of the dwellers.

  11. Vyhodnotenie malakofauny z náplavov Neresnice (stredné Slovensko Interpretation of molluscan fauna from the Neresnica River flood deposits (Central Slovakia

    Directory of Open Access Journals (Sweden)

    Marek Čiliak

    2011-11-01

    Full Text Available Sampling of flood debris deposits can be useful method in insufficiently surveyed areas. This sampling method also allows us to detect the presence of rare and endangered species in the study area. We studied flood debris along the Neresnica River to gather data on mollusc fauna of the Pliešovská Kotlina basin and the Javorie Mts. (Central Slovakia. In spring 2010, samples of flood debris were taken at three sites along the river. Molluscan thanatocoenoses were composed of 68 species (56 terrestrial and 12 aquatic ones. The most notable records were two subterranean species – Lucilla scintilla and L. singleyana, and also the species of nature conservation interest – Vertigo angustior. We found representatives of all ecological groups of molluscs, which provide the evidence of ecosystem diversity in various habitats along the river. We documented that the land use of the studied drainage basin was only partially reflected by the structure of mollusc assemblages from flood deposits.

  12. Comparison of Two Landslides and Related Outburst Flood Deposits and Their Effects on River Evolution, Owyhee River, Oregon

    Science.gov (United States)

    Othus, S.; Ely, L.; House, K.; Safran, L.; O'Connor, J. E.; Fenton, C.

    2007-12-01

    Abundant channel-encroaching landslides and lava flows on the Owyhee River in southeastern Oregon have the capacity to both inhibit incision by altering channel slope, width, and bed character, and burying valley-bottom bedrock under exogenous material, and promote incision by generating cataclysmic floods through natural dam failures. We hypothesize that these extrafluvial events play a significant role in creating and maintaining the geomorphic features of river canyons in uplifted volcanic terraces that comprise a significant part of the western U.S. Numerous landslides have entered the Owyhee River canyon north of Rome, Oregon. As the river flows through different lithologic units, the style of mass wasting changes from large slump events to large debris flows. These differences seem to be related to the composition and thickness of the underlying, exposed Tertiary sediments relative to the basalt cap. The largest exemplary mass wasting events of each morphologic category in two reaches were examined to compare the effects of these events on the river channel. Multiple slump events ranging in age from approximately 104 to 105 ka have impacted the river channel near Artillery Rapid (River km 33 from Rome, OR). At least one of these appears to have dammed the channel and failed catastrophically, creating a flood bar immediately downstream, with boulders up to 3 m in diameter that decrease in size with distance from the landslide dam. Greeley Debris Flow (River km 70), the largest debris flow in the Hole in the Ground reach, blocked the channel, creating extensive fill terraces behind the landslide dam and a large depositional flood bar downstream, with an age possibly as young as early Holocene. Downstream of both landslide reaches, outburst flood deposits of large boulders armoring the channel were measured and used to determine the velocity of the outburst flood that entrained the boulders. Based on this evidence, it is clear that landslides have affected the

  13. Communities of gastrointestinal helminths of fish in historically connected habitats: habitat fragmentation effect in a carnivorous catfish Pelteobagrus fulvidraco from seven lakes in flood plain of the Yangtze River, China

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    Yao Wei J

    2009-04-01

    Full Text Available Abstract Background Habitat fragmentation may result in the reduction of diversity of parasite communities by affecting population size and dispersal pattern of species. In the flood plain of the Yangtze River in China, many lakes, which were once connected with the river, have become isolated since the 1950s from the river by the construction of dams and sluices, with many larger lakes subdivided into smaller ones by road embankments. These artificial barriers have inevitably obstructed the migration of fish between the river and lakes and also among lakes. In this study, the gastrointestinal helminth communities were investigated in a carnivorous fish, the yellowhead catfish Pelteobagrus fulvidraco, from two connected and five isolated lakes in the flood plain in order to detect the effect of lake fragmentation on the parasite communities. Results A total of 11 species of helminths were recorded in the stomach and intestine of P. fulvidraco from seven lakes, including two lakes connected with the Yangtze River, i.e. Poyang and Dongting lakes, and five isolated lakes, i.e. Honghu, Liangzi, Tangxun, Niushan and Baoan lakes. Mean helminth individuals and diversity of helminth communities in Honghu and Dongting lakes was lower than in the other five lakes. The nematode Procamallanus fulvidraconis was the dominant species of communities in all the seven lakes. No significant difference in the Shannon-Wiener index was detected between connected lakes (0.48 and isolated lakes (0.50. The similarity of helminth communities between Niushan and Baoan lakes was the highest (0.6708, and the lowest was between Tangxun and Dongting lakes (0.1807. The similarity was low between Dongting and the other lakes, and the similarity decreased with the geographic distance among these lakes. The helminth community in one connected lake, Poyang Lake was clustered with isolated lakes, but the community in Dongting Lake was separated in the tree. Conclusion The

  14. Communities of gastrointestinal helminths of fish in historically connected habitats: habitat fragmentation effect in a carnivorous catfish Pelteobagrus fulvidraco from seven lakes in flood plain of the Yangtze River, China.

    Science.gov (United States)

    Li, Wen X; Nie, Pin; Wang, Gui T; Yao, Wei J

    2009-04-27

    Habitat fragmentation may result in the reduction of diversity of parasite communities by affecting population size and dispersal pattern of species. In the flood plain of the Yangtze River in China, many lakes, which were once connected with the river, have become isolated since the 1950s from the river by the construction of dams and sluices, with many larger lakes subdivided into smaller ones by road embankments. These artificial barriers have inevitably obstructed the migration of fish between the river and lakes and also among lakes. In this study, the gastrointestinal helminth communities were investigated in a carnivorous fish, the yellowhead catfish Pelteobagrus fulvidraco, from two connected and five isolated lakes in the flood plain in order to detect the effect of lake fragmentation on the parasite communities. A total of 11 species of helminths were recorded in the stomach and intestine of P. fulvidraco from seven lakes, including two lakes connected with the Yangtze River, i.e. Poyang and Dongting lakes, and five isolated lakes, i.e. Honghu, Liangzi, Tangxun, Niushan and Baoan lakes. Mean helminth individuals and diversity of helminth communities in Honghu and Dongting lakes was lower than in the other five lakes. The nematode Procamallanus fulvidraconis was the dominant species of communities in all the seven lakes. No significant difference in the Shannon-Wiener index was detected between connected lakes (0.48) and isolated lakes (0.50). The similarity of helminth communities between Niushan and Baoan lakes was the highest (0.6708), and the lowest was between Tangxun and Dongting lakes (0.1807). The similarity was low between Dongting and the other lakes, and the similarity decreased with the geographic distance among these lakes. The helminth community in one connected lake, Poyang Lake was clustered with isolated lakes, but the community in Dongting Lake was separated in the tree. The similarity in the helminth communities of this fish in the flood-plain

  15. Flood frequency analysis of Ganga river at Haridwar and Garhmukteshwar

    Science.gov (United States)

    Kamal, Vikas; Mukherjee, Saumitra; Singh, P.; Sen, R.; Vishwakarma, C. A.; Sajadi, P.; Asthana, H.; Rena, V.

    2016-02-01

    The Ganga River is a major river of North India and is known for its fertile alluvium deposits formed due to floods throughout the Indo-Gangetic plains. Flood frequency analysis has been carried out through various approaches for the Ganga River by many scientists. With changes in river bed brought out by anthropogenic changes the intensity of flood has also changed in the last decade, which calls for further study. The present study is in a part of the Upper Indo-Ganga plains subzone 1(e). Statistical distributions applied on the discharge data at two stations found that for Haridwar lognormal and for Garhmukteshwar Gumbel EV1 is applicable. The importance of this study lies in its ability to predict the discharge for a return period after a suitable distribution is found for an area.

  16. Flood frequency analysis of Ganga river at Haridwar and Garhmukteshwar

    Science.gov (United States)

    Kamal, Vikas; Mukherjee, Saumitra; Singh, P.; Sen, R.; Vishwakarma, C. A.; Sajadi, P.; Asthana, H.; Rena, V.

    2017-07-01

    The Ganga River is a major river of North India and is known for its fertile alluvium deposits formed due to floods throughout the Indo-Gangetic plains. Flood frequency analysis has been carried out through various approaches for the Ganga River by many scientists. With changes in river bed brought out by anthropogenic changes the intensity of flood has also changed in the last decade, which calls for further study. The present study is in a part of the Upper Indo-Ganga plains subzone 1(e). Statistical distributions applied on the discharge data at two stations found that for Haridwar lognormal and for Garhmukteshwar Gumbel EV1 is applicable. The importance of this study lies in its ability to predict the discharge for a return period after a suitable distribution is found for an area.

  17. Hydrologic Controls On Methylmercury Availability In Coastal Plain Rivers

    Science.gov (United States)

    Bradley, P. M.; Brigham, M. E.; Burns, D. A.; Button, D. T.; Lutz, M. A.; Marvin-DiPasquale, M. C.; Riva-Murray, K.; Journey, C.

    2011-12-01

    Methylmercury (MeHg) in streams is often attributed to methylation in up-gradient wetland areas, with episodic flood events maximizing wetland-stream hydrologic connectivity and dominating MeHg supply to the stream habitat. A number of studies have demonstrated that Coastal Plain streams in the southeastern United States are particularly vulnerable to high MeHg bioaccumulation and have attributed this vulnerability to wetland abundance and strong hydrologic connectivity between wetland areas and adjacent stream aquatic habitat. Because characteristically coarse-grained Coastal Plain sediments favor vertical infiltration with little surface runoff, flood events attributable to Coastal Plain precipitation are driven by rising groundwater, promoting efficient transport of MeHg from wetland/floodplain source areas to the stream habitat and increasing in-stream availability. Several observations at McTier Creek, South Carolina, however, suggest that good hydrologic connectivity and efficient MeHg transport in Coastal Plain systems are not limited to flood conditions. Close correspondence between stream and shallow-groundwater water levels at McTier indicate good hydrologic connectivity exists prior to flood conditions. Dissolved MeHg concentrations do not increase under flood conditions. Thus, we assessed the flux of water and dissolved mercury (Hg) species (FMeHg and total Hg (FTHg)) from surface water and groundwater sources in a short reach at McTier Creek during separate events in April and July 2009, to determine the importance of shallow groundwater Hg transport from floodplain areas to the stream under non-flood conditions. Mass balance assessments indicated that, under non-flood conditions, the primary supply of water, FMeHg, and FTHg within the reach (excluding upstream surface-water influx) was groundwater discharge, rather than tributary transport from wetlands, in-stream MeHg production, or atmospheric deposition. The results indicate efficient transport of

  18. Climate change and the response of phenology of Great Tit, Summer Oak and herbivorous caterpillars on flood plain forest ecosystem during 1961-2007

    Science.gov (United States)

    Bartosova, L.; Trnka, M.; Bauer, Z.; Bauerova, J.; Stepanek, P.; Mozny, M.; Zalud, Z.

    2009-04-01

    In this study are presented the phenophases of three animal and plant species, which were observed on research plot Vranovice during 1961 - 2007 (47 years). The observation took place at typical flood plain forest of southern Moravia. These are one common bird Great Tit (Parus major), tree Summer Oak (Quercus robur) and caterpillars Tortrix moth (Tortrix viridana) and Winter Moth (Operophthera brumata). These species are dependent on each other during their development and together create trophic chain. In case of Summer Oak the phenophases were observed since the bud break to full foliage on the same specimen during the whole 47 years. During the same period were observed nesting of 843 nesting pairs of Great Tit. We determined the first laying date (FLD), which was defined as the date when the first clutch in a given year was initiated and mean laying date (MLD), which was defined as the mean initiation date of the all first clutches in the population. The activity of caterpillars was observed indirectly using data on the intensity of caterpillars' frass fall-down that was systematically recorded throughout the study period. As the beginning of peak of excrement fall-down was taken the first day when this event was first observable. The conclusion phase was accompanied by migration of Winter Moth (Operophthera brumata) caterpillars to lower levels of the forest before the cocooning. Tortrix Moth (Tortrix viridana) caterpillars are cocooning (encapsulated) in folds of leaves. The phenophases of all three species has shifted to the earlier time during whole period of observation. The date of full foliage has advanced by 1.9 days per decade. FLD of Great Tit has shifted to the earlier time by 1.6 days and MLD has advanced by 1.5 days per decade. In both cases, the trends are statistically significant at α = 0.01. The dates of activity of caterpillars has shifted at the beginning by 2.02 and at the end by 2.06 days per decade. This trend is statictically highly

  19. Floods of Ohio and Mississippi Rivers, January-February 1937, with a section on the Flood deposits of the Ohio River, January-February 1937

    Science.gov (United States)

    Grover, Nathan Clifford; Mansfield, George Rogers

    1938-01-01

    In January and February 1937 the Ohio and mid-Mississippi Rivers experienced floods which, over reaches many hundreds of miles in length, exceeded all previously recorded stages. When measured by the loss of life and property, extent of damage, and general disruption of human activities, these floods constituted a major catastrophe.

  20. Log transport and deposition in incised, channelized, and multithread reaches of a wide mountain river: Tracking experiment during a 20-year flood

    Science.gov (United States)

    Wyżga, Bartłomiej; Mikuś, Paweł; Zawiejska, Joanna; Ruiz-Villanueva, Virginia; Kaczka, Ryszard J.; Czech, Wiktoria

    2017-02-01

    Distance of large wood transport during floods and conditions for wood deposition in wide mountain rivers are still insufficiently understood. Tracking of logs tagged with radio transmitters was used to investigate differences in depositional conditions and the length of log displacement during a 20-year flood between channel reaches of different morphology in the Czarny Dunajec River, Polish Carpathians. During the rising limb of the flood, logs were placed into the river at three locations: at the beginning of an incised reach, close to the beginning of a channelized reach, and 1 km upstream from the beginning of a wide, multithread reach. The incised, channelized, and multithread reaches retained 12.5%, 33%, and 94% of tagged logs introduced to these reaches, respectively, and of the logs retained in the multithread reach, all were deposited in its upstream half. Significant differences in the length of displacement existed between the logs delivered to the river at the three locations, with logs placed into the river at the beginning of the incised reach moving the longest distance, and those delivered just upstream from the multithread reach moving the shortest distance before deposition. One-fourth of the logs were deposited in a low-flow channel or on a channel margin, one-fifth on the floodplain, and more than half on gravel bars. After the flood, river cross sections with deposited logs and a set of cross sections without any wood deposits were surveyed to collect data for one-dimensional modelling of hydraulic conditions at the flood peak. The cross sections with deposited logs were typified by significantly greater flow width and flow area and by significantly smaller mean flow depth, mean velocity, Froude number, mean bed shear stress, and unit stream power. Principal component analysis of the hydraulic parameters in the analysed cross sections grouped the two types of cross sections in distinct clusters, indicating that multithread cross sections

  1. Investigation of the 2006 Drought and 2007 Flood Extremes at the Southern Great Plains Through an Integrative Analysis of Observations (Invited)

    Science.gov (United States)

    Dong, X.; Xi, B.; Kennedy, A. D.; Feng, Z.; Entin, J. K.; Houser, P.; Schiffer, R. A.; L'Ecuyer, T.; Olson, W. S.; Hsu, K.; Liu, T. W.; Lin, B.; Deng, Y.; Jiang, T.

    2010-12-01

    Hydrological years 2006 (HY06, 10/2005-09/2006) and 2007 (HY07, 10/2006-09/2007) provide a unique opportunity to examine hydrological extremes in the central US because there are no other examples of two such highly contrasting precipitation extremes occurring in consecutive years at the Southern Great Plains (SGP) in recorded history. The HY06 annual precipitation in the state of Oklahoma, as observed by the Oklahoma Mesonet, is around 61% of the normal (92.84 cm, based on the 1921-2008 climatology), which results in HY06 the second-driest year in the record. In particular, the total precipitation during the winter of 2005-06 is only 27% of the normal, and this winter ranks as the driest season. On the other hand, the HY07 annual precipitation amount is 121% of the normal and HY07 ranks as the seventh-wettest year for the entire state and the wettest year for the central region of the state. Summer 2007 is the second-wettest season for the state. Large-scale dynamics play a key role in these extreme events. During the extreme dry period (10/2005-02/2006), a dipole pattern in the 500-hPa GH anomaly existed where an anomalous high was over the southwestern U.S. region and an anomalous low was over the Great Lakes. This pattern is associated with inhibited moisture transport from the Gulf of Mexico and strong sinking motion over the SGP, both contributing to the extreme dryness. The precipitation deficit over the SGP during the extreme dry period is clearly linked to significantly suppressed cyclonic activity over the southwestern U.S., which shows robust relationship with the Western Pacific (WP) teleconnection pattern. The precipitation events during the extreme wet period (May-July 2007) were initially generated by active synoptic weather patterns, linked with moisture transport from the Gulf of Mexico by the northward low level jet, and enhanced the frequency of thunderstorms and their associated latent heat release. Although the drought and pluvial conditions

  2. 500-Year Floodplains, Flood plains from FEMA, Published in 2007, 1:600 (1in=50ft) scale, Town of Cary NC.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This 500-Year Floodplains dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from LIDAR information as of 2007. It is described as 'Flood...

  3. 100-Year Floodplains, Flood plains from FEMA, Published in 2003, 1:600 (1in=50ft) scale, Town of Cary NC.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This 100-Year Floodplains dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from LIDAR information as of 2003. It is described as 'Flood...

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

    Science.gov (United States)

    Soule, Pat LeRoy

    1978-01-01

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

  5. 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 ...

  6. Adaptive flood risk management in urban areas

    NARCIS (Netherlands)

    Mees, H.L.P.; Driessen, P.P.J.; Runhaar, H.A.C.

    2012-01-01

    In recent times a shift has occurred from traditional flood management focused on the prevention of flooding (reduction of the probability) only, to more adaptive strategies focused on the reduction of the impacts of floods as a means to improve the resilience of occupied flood plains to increased r

  7. Cordão Formation: loess deposits in the southern coastal plain of the state of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    RENATO P. LOPES

    Full Text Available ABSTRACT Loess consists of silt-dominated sediments that cover ~10% of the Earth's surface. In southern South America it occurs in Argentina, Bolivia, Paraguay and Uruguay, and its presence in southern Brazil was never studied in detail. Here is proposed a new lithostratigraphic unit, Cordão Formation, consisting of loess deposits in the southern Brazilian coastal plain. It consists of fine-very fine silt with subordinate sand and clay, found mostly in lowland areas between Pleistocene coastal barriers. These sediments are pale-colored (10YR hue and forms ~1,5-2,0 meter-thick stable vertical walls. The clay minerals include illite, smectite, interstratified illite/smectite and kaolinite, the coarser fraction is mostly quartz and plagioclase. Caliche and iron-manganese nodules are also present. The only fossils found so far are rodent teeth and a tooth of a camelid (Hemiauchenia paradoxa. Luminescence ages indicate that this loess was deposited in the latest Pleistocene, between ~30 and 10 kyrs ago, and its upper portion was modified by erosion and accumulation of clay and organic matter in the Holocene. The estimated accumulation rate was ~630 g/m2/year. The probable source of this loess is the Pampean Aeolian System of Argentina and it would have been deposited by the increased aeolian processes of the last glacial.

  8. Ground-water quality in quaternary deposits of the central high plains aquifer, south-central Kansas, 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Water samples from 20 randomly selected domestic water-supply wells completed in the Quaternary deposits of south-central Kansas were collected as part of the High...

  9. Risk analysis on agricultural drainage ditch filling and flood disasters in lower plain area of North China%华北低平原农田排水沟平填及洪涝灾害风险分析

    Institute of Scientific and Technical Information of China (English)

    赵晓宇; 张凤荣; 李超

    2016-01-01

    The construction of irrigation and water conservancy was initiated on the North China Plain in the 1950s, which played a significant role in the saline-alkali soil improvement and flood discharge. However, the phenomenon of filling agricultural drainage ditches has become common in the North China Plain since the 1990s. It is necessary to know the condition of filling agricultural drainage ditches and flood disasters related with this phenomenon. Nowadays, there are few researches to analyze the condition of filling agricultural drainage ditches. In order to enrich existing studies, this research took Cangxian County which was battered by flooding and soil salinization in lower plain area as a case study, and explored the condition of filling agricultural drainage ditch and the flood disaster. The changes of drainage ditch area and spatial variation were analyzed based on land use databases of Cangxian County in 1992 and 2010 using the method of GIS (geographic information system). Then, the condition of filling agricultural drainage ditch was investigated by means of the field research in Nan Gutun Village. This village was one of the most densely populated agriculture villages in Cangxian County. Interviewing with the village committee members and the villagers over 70 years old, we learned about the local agricultural production mode, the way of life, the changes of agricultural drainage ditch and its mechanisms from 1960s to now. Finally, we analyzed the risk of flood disasters from the aspects of precipitation trends, percentage of precipitation anomalies, underground water level, drought/flood frequency, relationship between soil water capacity and rainfall, and upland water condition. The results showed that from 1992 to 2010, the area of drainage ditches in Cangxian County reduced by 37.73%. Meanwhile, the proportion of drainage ditches in Cangxian County decreased by 2.03% and the farm ditches was the most serious in being filled. The results of flood

  10. 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.

  11. Spatial variability and uncertainty in ecological risk assessment: A case study on the potential risk of cadmium for the little owl in a Dutch river flood plain

    NARCIS (Netherlands)

    Kooistra, L.; Huijbregts, M.A.J.; Ragas, A.M.J.; Wehrens, H.R.M.J.; Leuven, R.S.E.W.

    2005-01-01

    This paper outlines a procedure that quantifies the impact of different sources of spatial variability and uncertainty on ecological risk estimates. The procedure is illustrated in a case study that estimates the risks of cadmium for a little owl (Athene noctua vidalli) living in a Dutch river flood

  12. Effects of elevated CO2 and nitrogen deposition on ecosystem carbon fluxes on the Sanjiang plain wetland in Northeast China.

    Directory of Open Access Journals (Sweden)

    Jianbo Wang

    Full Text Available BACKGROUND: Increasing atmospheric CO2 and nitrogen (N deposition across the globe may affect ecosystem CO2 exchanges and ecosystem carbon cycles. Additionally, it remains unknown how increased N deposition and N addition will alter the effects of elevated CO2 on wetland ecosystem carbon fluxes. METHODOLOGY/PRINCIPAL FINDINGS: Beginning in 2010, a paired, nested manipulative experimental design was used in a temperate wetland of northeastern China. The primary factor was elevated CO2, accomplished using Open Top Chambers, and N supplied as NH4NO3 was the secondary factor. Gross primary productivity (GPP was higher than ecosystem respiration (ER, leading to net carbon uptake (measured by net ecosystem CO2 exchange, or NEE in all four treatments over the growing season. However, their magnitude had interannual variations, which coincided with air temperature in the early growing season, with the soil temperature and with the vegetation cover. Elevated CO2 significantly enhanced GPP and ER but overall reduced NEE because the stimulation caused by the elevated CO2 had a greater impact on ER than on GPP. The addition of N stimulated ecosystem C fluxes in both years and ameliorated the negative impact of elevated CO2 on NEE. CONCLUSION/SIGNIFICANCE: In this ecosystem, future elevated CO2 may favor carbon sequestration when coupled with increasing nitrogen deposition.

  13. GEOMORPHOLOGICAL FEATURES AND SUBSURFACE GEOLOGY OF THE LOWER MEKONG PLAIN AROUND PHNOM PENH CITY, CAMBODIA (SOUTHEAST ASIA

    Directory of Open Access Journals (Sweden)

    Sumiko Kubo

    2008-06-01

    Full Text Available The geomorphological features of the Lower Mekong Plain and their relationships with floods, as well asthe subsurface geology and the major depositional processes in the area, are discussed. From theinterpretation of aerial photos and field reconnaissance, the Lower Mekong Plain in Cambodia ischaracterized as a floodplain with natural levees and back marshes. These geomorphological featuresinfluence the extent of the extensive inundation that occurs during every rainy (wet season. An extremeflood in 2000 confirmed the close relationship between micro-landforms and the flooding. A preliminarystudy of bore-hole logs in the area of Phnom Penh was also carried out. Base rocks are shallower in thewestern part, whereas thick (>130 m Quaternary deposits occur in the eastern part, suggesting the presenceof a structural basin.

  14. Distinguishing and correlating deposits from large ignimbrite eruptions using paleomagnetism: The Cougar Point Tuffs (mid-Miocene), southern Snake River Plain, Idaho, USA

    Science.gov (United States)

    Finn, David R.; Coe, Robert S.; Brown, Ethan; Branney, Michael; Reichow, Marc; Knott, Thomas; Storey, Michael; Bonnichsen, Bill

    2016-09-01

    In this paper, we present paleomagnetic, geochemical, mineralogical, and geochronologic evidence for correlation of the mid-Miocene Cougar Point Tuff (CPT) in southwest Snake River Plain (SRP) of Idaho. The new stratigraphy presented here significantly reduces the frequency and increases the scale of known SRP ignimbrite eruptions. The CPT section exposed at the Black Rock Escarpment along the Bruneau River has been correlated eastward to the Brown's Bench escarpment (six common eruption units) and Cassia Mountains (three common eruption units) regions of southern Idaho. The CPT records an unusual pattern of geomagnetic field directions that provides the basis for robust stratigraphic correlations. Paleomagnetic characterization of eruption units based on geomagnetic field variation has a resolution on the order of a few centuries, providing a strong test of whether two deposits could have been emplaced from the same eruption or from temporally separate events. To obtain reliable paleomagnetic directions, the anisotropy of anhysteretic remanence was measured to correct for magnetic anisotropy, and an efficient new method was used to remove gyroremanence acquired during alternating field demagnetization.

  15. 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)

  16. The Plains of Venus

    Science.gov (United States)

    Sharpton, V. L.

    2013-12-01

    Volcanic plains units of various types comprise at least 80% of the surface of Venus. Though devoid of topographic splendor and, therefore often overlooked, these plains units house a spectacular array of volcanic, tectonic, and impact features. Here I propose that the plains hold the keys to understanding the resurfacing history of Venus and resolving the global stratigraphy debate. The quasi-random distribution of impact craters and the small number that have been conspicuously modified from the outside by plains-forming volcanism have led some to propose that Venus was catastrophically resurfaced around 725×375 Ma with little volcanism since. Challenges, however, hinge on interpretations of certain morphological characteristics of impact craters: For instance, Venusian impact craters exhibit either radar dark (smooth) floor deposits or bright, blocky floors. Bright floor craters (BFC) are typically 100-400 m deeper than dark floor craters (DFC). Furthermore, all 58 impact craters with ephemeral bright ejecta rays and/or distal parabolic ejecta patterns have bright floor deposits. This suggests that BFCs are younger, on average, than DFCs. These observations suggest that DFCs could be partially filled with lava during plains emplacement and, therefore, are not strictly younger than the plains units as widely held. Because the DFC group comprises ~80% of the total crater population on Venus the recalculated emplacement age of the plains would be ~145 Ma if DFCs are indeed volcanically modified during plains formation. Improved image and topographic data are required to measure stratigraphic and morphometric relationships and resolve this issue. Plains units are also home to an abundant and diverse set of volcanic features including steep-sided domes, shield fields, isolated volcanoes, collapse features and lava channels, some of which extend for 1000s of kilometers. The inferred viscosity range of plains-forming lavas, therefore, is immense, ranging from the

  17. 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.

  18. Modeling Impact of Cross Drainage Works on Flood Propagation Dynamics

    Science.gov (United States)

    Haldar, R.; Khosa, R.; Gupta, S.

    2013-12-01

    River bed and flood plain geometries are formed as a response to centuries of natural erosional and depositional processes. Any human intervention made in the course of a river has the potential to create a disturbance in its flow pattern. The present study considers the possible consequences of changes made in the flood plain of a river and is an attempt to show how investigation and modeling prior to execution of water resources projects can be largely beneficial in desisting from unintended disasters. The Ghaggar River is a non- perennial stream that has its origin in the Shivalik Hills of Himachal Pradesh, India. It passes through the two states of Punjab and Haryana into Rajasthan. A flood investigation and modeling study was done for the Ghaggar River where it was attempted to simulate the change in the pattern of the flow in the main channel, and the propagation of excess waters in the flood plains, as a result of impediment created by the embankments of the Hansi-Butana Link canal, constructed recently during 2007-09. The study used daily rainfall data for the 2009 and 2010 monsoon seasons which was obtained from the India Meteorological Department. The modeling was done with the help of the MIKE SHE hydrologic model coupled with the MIKE 11 hydrodynamic model in order to estimate the peak river stage, the time to peak, and the recession time that was needed for the flood plains to get back to their normal dry state. It was found that the maximum impact of the canal embankment was felt on the flood recession time. The importance of the study was felt, when in the 2010 monsoons, the canal embankment that was acting as an obstruction to the speeding flood wave, cracked at places and fragments of the canal body were washed away by the flood water. Large areas of cultivated and inhabited land became inundated and stayed under water for weeks, when the volume of water captured by the canal embankments gradually drained through the various outlets made in the

  19. Assessment of Hyporheic Zone, Flood-Plain, Soil-Gas, Soil, and Surface-Water Contamination at the McCoys Creek Chemical Training Area, Fort Gordon, Georgia, 2009-2010

    Science.gov (United States)

    Guimaraes, Wladmir B.; Falls, W. Fred; Caldwell, Andral W.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, assessed the hyporheic zone, flood plain, soil gas, soil, and surface water for contaminants at the McCoys Creek Chemical Training Area (MCTA) at Fort Gordon, from October 2009 to September 2010. The assessment included the detection of organic contaminants in the hyporheic zone, flood plain, soil gas, and surface water. In addition, the organic contaminant assessment included the analysis of organic compounds classified as explosives and chemical agents in selected areas. Inorganic contaminants were assessed in soil and surface-water samples. The assessment was conducted to provide environmental contamination data to the U.S. Army at Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Ten passive samplers were deployed in the hyporheic zone and flood plain, and total petroleum hydrocarbons (TPH) and octane were detected above the method detection level in every sampler. Other organic compounds detected above the method detection level in the hyporheic zone and flood-plain samplers were trichloroethylene, and cis- and trans- 1, 2-dichloroethylene. One trip blank detected TPH below the method detection level but above the nondetection level. The concentrations of TPH in the samplers were many times greater than the concentrations detected in the blank; therefore, all other TPH concentrations detected are considered to represent environmental conditions. Seventy-one soil-gas samplers were deployed in a grid pattern across the MCTA. Three trip blanks and three method blanks were used and not deployed, and TPH was detected above the method detection level in two trip blanks and one method blank. Detection of TPH was observed at all 71 samplers, but because TPH was detected in the trip and method blanks, TPH was

  20. Deepwater carbonate deposition in response to re-flooding of carbonate bank and atoll-tops at glacial terminations

    Science.gov (United States)

    Jorry, Stéphan J.; Droxler, André W.; Francis, Jason M.

    2010-08-01

    The late Quaternary has experienced large glacial/interglacial climatic variations and related 10's to 100 meters high-amplitude sea level fluctuations at Milankovich frequencies from 10's to 100 kyr during which carbonate platform tops have been exposed and re-flooded in many occasions. This study focuses on the accumulation of calci-turbidites, the aragonite onset/sharp increase in fine sediments and their timing in deep basins adjacent to carbonate platforms. A particular emphasis is developed on the occurrence of the first gravity flow event and aragonite onset/sharp increase and their linkage to the initial re-flooding of the platform tops during deglaciations. Three basins adjacent to isolated platforms in the Bahamas, the Northern Nicaragua Rise, and the Gulf of Papua, were selected to represent pure carbonate versus mixed systems, in quiescent versus tectonically active settings, and various carbonate bank top morphologies, ranging from atoll to relatively deeply and narrowly flooded flat top banks. In spite of these differences, each record illustrates a clear relationship between the timing of platform top re-flooding and initiation of significant carbonate export by gravity flows and low-density plumes into the surrounding basins. The concept of "re-flooding window" is introduced to characterize the prolific period of time during which bank and atoll-tops are flooded enough to produce large export of bank-derived aragonite and of calci-turbidites in adjacent basins. According to our datasets, the main re-flooding windows have occurred mainly on the last part of the sea level rise at each glacial termination (T), those periods being marked by some of the highest rates of sea level rise. The analysis of a long-piston core from the earthquakes-prone Walton Basin (Northern Nicaragua Rise) demonstrates that sea level, not seismic activities, played a major role as trigger mechanism for the initiation of gravity flows since the last four glacial

  1. Alluvial plain dynamics in the southern Amazonian foreland basin

    Science.gov (United States)

    Lombardo, Umberto

    2016-05-01

    Alluvial plains are formed with sediments that rivers deposit on the adjacent flood-basin, mainly through crevasse splays and avulsions. These result from a combination of processes, some of which push the river towards the crevasse threshold, while others act as triggers. Based on the floodplain sedimentation patterns of large rivers in the southern Amazonian foreland basin, it has been suggested that alluvial plain sediment accumulation is primarily the result of river crevasse splays and sheet sands triggered by above-normal precipitation events due to La Niña. However, more than 90 % of the Amazonian river network is made of small rivers and it is unknown whether small river floodplain sedimentation is influenced by the ENSO cycle as well. Using Landsat images from 1984 to 2014, here I analyse the behaviour of all 12 tributaries of the Río Mamoré with a catchment in the Andes. I show that these are very active rivers and that the frequency of crevasses is not linked to ENSO activity. The data suggest that most of the sediments eroded from the Andes by the tributaries of the Mamoré are deposited in the alluvial plains, before reaching the parent river. The mid-to-late Holocene paleo-channels of these rivers are located tens of kilometres further away from the Andes than the modern crevasses. I conclude that the frequency of crevasses is controlled by intrabasinal processes that act on a yearly to decadal timescale, while the average location of the crevasses is controlled by climatic or neo-tectonic events that act on a millennial scale. Finally, I discuss the implications of river dynamics on rural livelihoods and biodiversity in the Llanos de Moxos, a seasonally flooded savannah covering most of the southern Amazonian foreland basin and the world's largest RAMSAR site.

  2. Deglacial Flood Origin of the Charleston Alluvial Fan, Lower Mississippi Alluvial Valley

    Science.gov (United States)

    Porter, Donna A.; Guccione, Margaret J.

    1994-05-01

    Large-magnitude flooding of the Mississippi River from proglacial lakes Agassiz and Superior most likely occurred between 11,300 and 10,900 and 9900 and 9500 yr B.P. The Charleston alluvial fan, a depositional remnant of one of these floods, is located at the head of a wide alluvial plain near Charleston, Missouri. The fan is an elongate, convex-up sand body (16 × 24 km) composed of medium- and fine-grained sand at least 8 m thick. This sand contrasts with the older coarse-grained sand of the braided stream surface to the west and south and younger silty clay of the meandering stream level to the north and east. A weakly developed soil separates the underlying braided steam deposits from the alluvial fan. A bulk-soil radiocarbon date of 10,590 ± 200 yr B.P. from the contact between the fan and clays of the meandering stream system indicates that the Charleston fan was deposited near the end of the early interval of flooding from Lake Agassiz about 10,900 yr B.P. If the Charleston fan is the last remnant of deglacial flooding in the lower Mississippi Valley, then deposition of significant quantities of sediment from largemagnitude floods between 10,000 and 9500 yr B.P. did not extend into the lower Mississippi Valley through Thebes Gap.

  3. Hydrogeological characteristics of the Paraíba do Sul river flood plains: a case study of a mining area in the Tremembé municipality, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo dos Santos Targa

    2010-12-01

    Full Text Available The sand mining activity in the São Paulo part of the Paraíba do Sul River Valley started in the 1950s, in the area of Jacareí municipality, located in the Southwestern part of the basin. From there, it advanced by the neighboring municipalities, fostered by urbanization and industrialization processes, especially of São Paulo Metropolitan Region. The lack of detailed hydrogeological studies in this area motivated this study that had the objective of verifying the hypothesis that sand mining pits interfere on the quality and storage of the water in the quaternary sedimentary aquifer. This study focused specifically in the eastern part of the Tremembé Municipality, São Paulo State, in a mining place called “Mineração Paraíso”. The investigation involved infiltration and flow tests, laboratory analyses of soil physical parameters and estimation, water quality indices and infrastructure construction for equipment installation including piezometers, dynamic penetration tests – (SPT - Standard Penetration Test, wells opening and office analyses. The soil physical parameters analyses revealed high porosity (66% in the friable soils. This in addition to the high levels of transmissivity (15.5 m2/h measured in Well 1 and 33 m2/h in Well 3, obtained from the flow test, increases the speed of the transportation of solutes including bacteria, to the underground water. Results of the granulometric analyses showed that the sand mining technique is not only predatory, but also inefficient, since the sand at the bottom of the pit is left unexploited, as well as the bentonite clay found in the deeper layers. According to the penetration tests (SPT, the aquifer has an average thickness of 5.5 m and an upper layer of impermeable organic clays that confine the sand deposits. Furthermore, an aquiclude composed of green bentonitic clays was identified just below the confined layer. However, it is necessary to point out that the confinement condition

  4. 北京市平原区农田土壤蚀积特征分析%Analysis on Farmland Soil Erosion and Deposition Features in Beijing Plain

    Institute of Scientific and Technical Information of China (English)

    王仁德; 邹学勇; 赵婧妍; 张艺磊

    2011-01-01

    By bays of field observations, wind-tunnel simulation and laboratory analysis, under the common function of soil wind-erosion and atmospheric dustfall, the farmland soil erosion and sedimentary characteristics in Beijing plain and its effect on soil physical and chemical properties were studied.The results showed that soil erosion intensity in 2009 was 0.64 t/hm2 ,with particle diameter of 20~80 μm in the main;the atmospheric dustfall intensity is 1.00 t/hm2 , with particle diameter of 10~50 μm in the main.The intensity of dustfall was over that of soil erosion, so deposition happenned in farmland surface with strength of about 0.36 t/hm2 · a.Size of dustfall particles was smaller obviously than that of wind-erosion dusts, this leaded to the soil particles becoming finer and finer by long-term erosion and deposition effect.The content of heavy metal elements in dustfall was higher than that of soil and wind-erosion dusts, which leaded to the accumulation of heavy metals in soil.%采用野外观测、风洞模拟和实验室分析等手段,对北京市平原区土壤风蚀和大气降尘两种自然过程共同作用下的农田土壤蚀积状况及其对土壤理化性质的影响问题进行了研究.结果表明,2009年研究区农田土壤风蚀强度为0.64 t/hm2,风蚀物颗粒以粒径在20~80μm的尘粒为主;大气降尘强度为1.00 t/hm2,降尘颗粒以粒径在10~50μm的尘粒为主.降尘强度大于土壤风蚀强度,农田地表以沉积为主,强度约为0.36 t/hm2·a.降尘粒径比风蚀物粒径明显偏细,长期的蚀积作用导致土壤粒度组成变细.降尘中重金属元索的含量明显大于土壤和风蚀物中的含量,长期沉积作用导致土壤中重金属元素的累积.

  5. 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

  6. Flood hazard and management: a UK perspective.

    Science.gov (United States)

    Wheater, Howard S

    2006-08-15

    This paper discusses whether flood hazard in the UK is increasing and considers issues of flood risk management. Urban development is known to increase fluvial flood frequency, hence design measures are routinely implemented to minimize the impact. Studies suggest that historical effects, while potentially large at small scale, are not significant for large river basins. Storm water flooding within the urban environment is an area where flood hazard is inadequately defined; new methods are needed to assess and manage flood risk. Development on flood plains has led to major capital expenditure on flood protection, but government is attempting to strengthen the planning role of the environmental regulator to prevent this. Rural land use management has intensified significantly over the past 30 years, leading to concerns that flood risk has increased, at least at local scale; the implications for catchment-scale flooding are unclear. New research is addressing this issue, and more broadly, the role of land management in reducing flood risk. Climate change impacts on flooding and current guidelines for UK practice are reviewed. Large uncertainties remain, not least for the occurrence of extreme precipitation, but precautionary guidance is in place. Finally, current levels of flood protection are discussed. Reassessment of flood hazard has led to targets for increased flood protection, but despite important developments to communicate flood risk to the public, much remains to be done to increase public awareness of flood hazard.

  7. Multidisciplinary distinction of mass-movement and flood-induced deposits in lacustrine environments: implications for Holocene palaeohydrology and natural hazards (Lake Ledro, Southern Alps, Italy

    Directory of Open Access Journals (Sweden)

    A. Simonneau

    2012-08-01

    Full Text Available High-resolution seismic profiles and sediment cores from Lake Ledro combined with soil and river-bed samples from the lake's catchment area are used to assess the recurrence of natural hazards (earthquakes and flood events in the southern Italian Alps during the Holocene. Two well-developed deltas and a flat central basin are identified on seismic profiles in Lake Ledro. Lake sediments are finely laminated in the basin since 9000 cal. yr BP and frequently interrupted by two types of sedimentary events: light-coloured massive layers and dark-coloured graded beds. Optical analysis (quantitative organic petrography of the organic matter occurring in soils, river beds and lacustrine samples together with lake-sediment bulk density and grain-size analysis illustrate that light-coloured layers consist of a mixture of lacustrine sediments and mainly contain algal particles similar to the ones observed in background sediments. Light-coloured layers thicker than 1.5 cm in the main basin of Lake Ledro are dense and synchronous to numerous coeval mass-wasting deposits remoulding the slopes of the basin. They are interpreted as subaquatic mass movements triggered by historical and pre-historical regional earthquakes dated to 2005 AD, 1891 AD, 1045 AD and 1260, 2545, 2595, 3350, 3815, 4740, 7190, 9185 and 11495 cal. yr BP. Dark-coloured sedimentary event are dense and develop high-amplitude reflections in front of the deltas and in the deep central basin. These beds are mainly made of terrestrial organic matter (soils and ligno-cellulosic debris and are interpreted as resulting from intense hyperpycnal flood events. Mapping and quantifying the amount of soil material accumulated in the Holocene hyperpycnal flood deposits of the sequence and applying the De Ploey erosion model allow estimating that the equivalent soil thickness eroded over the catchment area reached up to 4 mm during the largest Holocene flood events. Such significant soil erosion is

  8. 2011 floods of the central United States

    Science.gov (United States)

    ,

    2013-01-01

    The Central United States experienced record-setting flooding during 2011, with floods that extended from headwater streams in the Rocky Mountains, to transboundary rivers in the upper Midwest and Northern Plains, to the deep and wide sand-bedded lower Mississippi River. The U.S. Geological Survey (USGS), as part of its mission, collected extensive information during and in the aftermath of the 2011 floods to support scientific analysis of the origins and consequences of extreme floods. The information collected for the 2011 floods, combined with decades of past data, enables scientists and engineers from the USGS to provide syntheses and scientific analyses to inform emergency managers, planners, and policy makers about life-safety, economic, and environmental-health issues surrounding flood hazards for the 2011 floods and future floods like it. USGS data, information, and scientific analyses provide context and understanding of the effect of floods on complex societal issues such as ecosystem and human health, flood-plain management, climate-change adaptation, economic security, and the associated policies enacted for mitigation. Among the largest societal questions is "How do we balance agricultural, economic, life-safety, and environmental needs in and along our rivers?" To address this issue, many scientific questions have to be answered including the following: * How do the 2011 weather and flood conditions compare to the past weather and flood conditions and what can we reasonably expect in the future for flood magnitudes?

  9. Investigations of the contamination of forest, meadow and field soils with selected organic pollutants in the flood-plain of the river Mulde near Bitterfeld; Untersuchungen zur Kontamination von Wald-, Wiesen- und Ackerboeden mit ausgewaehlten Organika in der Muldenaue bei Bitterfeld

    Energy Technology Data Exchange (ETDEWEB)

    Borsdorf, H. [Umweltforschungszentrum Leipzig-Halle GmbH, Leipzig (Germany). Sektion Analytik; Opp, C.; Stach, J. [Bruker-Saxonia Analytik GmbH (Germany)

    1993-12-01

    The flood-plain of the river Mulde represents a sink for organic compounds stemming from the river basin of the river Mulde as well as from the chemical industrial complex of Bitterfeld-Wolfen. In this area, at positions both near and far from the industrial emitters, selected organic compounds of soil profiles under wood, meadow and arable land up to a depth of 60 cm each were investigated. In dependence of the different use to the soils considerable differences of the matter concentrations were founded. The analyzed concentrations of some to the organic compounds are higher than current critical values. (orig.)

  10. Plains Traveler

    Science.gov (United States)

    2006-01-01

    10 April 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a dust devil traveling across a plain west-southwest of Schiaparelli Crater, in far eastern Sinus Meridiani. The dust devil is casting a shadow toward the northeast, just south (below) of an egg-shaped crater. Location near: 6.4oS, 349.3oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

  11. Utopia Plain

    Science.gov (United States)

    2006-01-01

    5 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a dark-toned, cratered plain in southwest Utopia Planitia. Large, light-toned, windblown ripples reside on the floors of many of the depressions in the scene, including a long, linear, trough. Location near: 30.3oN, 255.3oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  12. River diversions, avulsions and captures in the Tortuguero coastal plain

    Science.gov (United States)

    Galve, Jorge Pedro; Alvarado, Guillermo; Pérez Peña, José Vicente; Azañón, José Miguel; Mora, Mauricio; Booth-Rea, Guillermo

    2016-04-01

    The Tortuguero area is a coastal plain that forms part of the North Limón sedimentary basin, the back-arc region of the Caribbean side of Costa Rica. This coastal plain is characterised by an abnormal drainage pattern with river captures, diversions and shifts in channel directions. We are analyzing this anomalous drainage network adopting a classical geomorphological approach combined with geomorphometric techniques. The SRTM DEM at 1 arc-second of resolution (~30 m) from NASA, topographic maps 1:50,000, satellital images and the digital cartography of the drainage network have been used for inventorying the channel pattern anomalies. River segments were categorized according to sinuosity, orientation, slope changes and incision using GIS tools. Initially, anomalies in the analyzed river courses suggested that buried thrust fronts could disrupt their natural pattern. However, we have not identified any evidence to link the activity of buried structures with the disruption of natural drainage. Blind thrusts detected through seismic subsurface exploration in the SE sector of the Tortuguero plain do not seem to produce changes in the sinuosity, orientation, slope and incision of rivers as those observed in the deeply studied tectonically active area of the Po Plain (Italy). The identified river pattern anomalies have been explained due to other alternative causes: (1) the migration of the mouths of Reventazón, Pacuare and Matina rivers is produced by sand sedimentation in the coast because of a successive ridge beach formation. This migration to the SE has the same direction than the main ocean currents those deposited the sand. (2) The anomalous course of Parismina river is most probably conditioned by the fracturation of the dissected volcanic apron of Turrialba volcano. (3) Channel migration and capture of Barbilla river by Matina river can be triggered by the tectonic tilting of the coastal plain towards the SE. The subsidence of the SE sector of the plain was

  13. Morphosedimentary features from a major flood on a small, lower-sinuosity, single-thread river: The unknown quantity of overbank deposition, historical-change context, and comparisons with a multichannel river

    Science.gov (United States)

    Joeckel, R. M.; Tucker, S. T.; McMullin, J. D.

    2016-08-01

    This study details overbank sedimentation on a single-thread, bedload stream, the Little Blue River (southeastern Nebraska and northeastern Kansas, USA), which experienced exceptional floods during May-June 2015. Downvalley elongate splays left deposits as thick as 1.2 m and attained areas as great as 156 ha. Splays consisted of fields of large, gravel-covered dunes 0.1 to 0.3 m in height and extensive sand sheets with current ripples or current ripples atop low-relief, long-wavelength dunes. Erosion occurred chiefly in the heads of splays. Levee-floodplain channel complexes were more architecturally complicated, with channel-channel-fringing deposits deposited within 110 m of the banks of the channel. These complexes consisted of two amalgamated components: (1) sediment shadows (vegetation-induced sedimentary structures), as long as 6 m and as high as 0.6 m at their heads, which were produced by the interaction of direct overbank flow with rooted trees; and (2) indistinct, flat-topped bars (some of which were built around eroded remnants of sediment shadows) shaped chiefly by downvalley flood flow. Changes on in-channel bars, the erosion of bank crevasses as large as 70 m in width, and the deposition of large woody debris also occurred during the floods. The earliest aerial photographs (1938) of the study area, taken after multiple low-flow years, show no evidence for recent overbank deposition. Increases in channel-belt area, the number of bars, and the sizes of bars in the Little Blue River took place after 1938, and most rapidly during 1938 to 1950, when annual discharge was increasing. Annual discharge has decreased since ca. 1990, and yet there has been a long-term increase in annual peak from since the 1930s. We surmise that increasing annual peak flows have led to larger floods and, since 1938, serial overbank deposition, as well a wider channel and numerous, large compound bars.

  14. The use of novel wooden structures to manage flooding and coarse sediment problems in responsive upland headwater catchments

    Science.gov (United States)

    Wilkinson, Mark; Addy, Steve; Ghimire, Sohan; Watson, Helen; Stutter, Marc

    2014-05-01

    Over the past decade economic losses from floods have greatly increased, with sediment related impacts as a key feature of such events. Impacts include changes in river channel course, scour of river banks, sedimentation of infrastructure (e.g. bridges), and deposition of sand and gravel on farmland. Sediment deposition can in turn reduce conveyance capacity and lead to further increased flood risk. The EU Water Framework Directive and Floods Directive highlights that sustainable approaches to flood risk reduction should be used alongside and, where possible, replace traditional structural flood defences and activities that address sediment problems. Natural Flood Management(NFM) is promoted as a method that can reduce flood risk and manage sediment by incorporating natural hydrological and morphological processes. As such, NFM measures are designed to use these fluvial processes to manage the sources and pathways of flood waters and sediments. Techniques include the restoration, enhancement and alteration of natural features and characteristics, but exclude traditional flood defence engineering that works against or disrupts these natural processes. Here we aim to assess the effectiveness of novel flood mitigation measures for reducing flood risk and capturing coarse sediment in rapidly responding headwater catchments. We present preliminary research findings from a densely instrumented research site (Bowmont catchment, Scotland (85km2)) which regularly experiences flood events with associated coarse sediment problems. NFM measures have been installed to capture course sediment and to store water more effectively on the flood plains during these flood events. For example, novel engineered wooden structures ('bar apex log jams') constructed in the river corridor are designed to trap sediment and log bank protection structures have been installed to stop bank erosion. Within a tributary catchment of the Bowmont (0.7km2), new flow restrictors have been installed on a

  15. Limestone Creek, Local Flood Protection, Fayetteville, New York

    Science.gov (United States)

    1990-08-01

    need "o comply with flood insurance and flood plain managemnet policies now in effect. 4.35 Plan I - Levee/Floodwaii Protection - Flood damage...October 1 is not possible without the risk of significant adverse impact to the indigenous salmonid population. Please advise us of action taken

  16. Revisiting Plain Language.

    Science.gov (United States)

    Mazur, Beth

    2000-01-01

    Discusses the plain language movement and its origins. Reviews past and current resources related to plain language writing. Examines criticism of the movement while examining past and current plain language literature, with particular attention to the information design field. (SR)

  17. Flood-inundation maps for a 15-mile reach of the Kalamazoo River from Marshall to Battle Creek, Michigan, 2010

    Science.gov (United States)

    Hoard, C.J.; Fowler, K.K.; Kim, M.H.; Menke, C.D.; Morlock, S.E.; Peppler, M.C.; Rachol, C.M.; Whitehead, M.T.

    2010-01-01

    Digital flood-inundation maps for a 15-mile reach of the Kalamazoo River from Marshall to Battle Creek, Michigan, were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency to help guide remediation efforts following a crude-oil spill on July 25, 2010. The spill happened on Talmadge Creek, a tributary of the Kalamazoo River near Marshall, during a flood. The floodwaters transported the spilled oil down the Kalamazoo River and deposited oil in impoundments and on the surfaces of islands and flood plains. Six flood-inundation maps were constructed corresponding to the flood stage (884.09 feet) coincident with the oil spill on July 25, 2010, as well as for floods with annual exceedance probabilities of 0.2, 1, 2, 4, and 10 percent. Streamflow at the USGS streamgage at Marshall, Michigan (USGS site ID 04103500), was used to calculate the flood probabilities. From August 13 to 18, 2010, 35 channel cross sections, 17 bridges and 1 dam were surveyed. These data were used to construct a water-surface profile for the July 25, 2010, flood by use of a one-dimensional step-backwater model. The calibrated model was used to estimate water-surface profiles for other flood probabilities. The resulting six flood-inundation maps were created with a geographic information system by combining flood profiles with a 1.2-foot vertical and 10-foot horizontal resolution digital elevation model derived from Light Detection and Ranging data.

  18. Extensive deposits on the Pacific plate from Late Pleistocene North American glacial lake outbursts

    Science.gov (United States)

    Normark, W.R.; Reid, J.A.

    2003-01-01

    One of the major unresolved issues of the Late Pleistocene catastrophic-flood events in the northwestern United States (e.g., from glacial Lake Missoula) has been what happened when the flood discharge reached the ocean. This study compiles available 3.5-kHz high-resolution and airgun seismic reflection data, long-range sidescan sonar images, and sediment core data to define the distribution of flood sediment in deepwater areas of the Pacific Ocean. Upon reaching the ocean at the mouth of the Columbia River near the present-day upper continental slope, sediment from the catastrophic floods continued flowing downslope as hyperpycnally generated turbidity currents. The turbidity currents resulting from the Lake Missoula and other latest Pleistocene floods followed the Cascadia Channel into and through the Blanco Fracture Zone and then flowed west to the Tufts Abyssal Plain. A small part of the flood sediment, which was stripped off the main flow at a bend in the Cascadia Channel at its exit point from the Blanco Fracture Zone, continued flowing more than 400 km to the south and reached the Escanaba Trough, a rift valley of the southern Gorda Ridge. Understanding the development of the pathway for the Late Pleistocene flood sediment reaching Escanaba Trough provides insight for understanding the extent of catastrophic flood deposits on the Pacific plate.

  19. Coastal plain pond water quality and mercury contend of biota of the Long Island Central Pine Barrens and Mashomack Preserve: Effects of atmospheric deposition and human development

    Science.gov (United States)

    Lawrence, Gregory B.; Siemion, Jason; Lane, Oksana P.

    2015-01-01

    Pine barrens are considered an imperiled ecosystem in the northeastern U.S. The Suffolk County Pine Barrens, once the second largest in the Northeast, were substantially reduced and fragmented by development during the 20th century. The coastal plain ponds being considered in this study occur in central Suffolk County within the Long Island Central Pine Barrens region. This highly unique natural environment, embedded with forests and woodlands, resulted from its glacial origins and a land use history that predates European colonization. Included in this study was The Nature Conservancy’s Mashomack Preserve, located on Shelter Island between Peconic Bay and Gardiner’s Bay. There are no freshwater ponds in the Mashomack Preserve, but this area was included with the Central Pine Barrens investigation, because Shelter Island has a similar geologic and land-use history that has resulted in a similarly unique low-nutrient forest and woodland ecosystem with extremely coarse-textured soils.

  20. Vegetation line transects of Goose Pasture and Pool No. 1: Part of Wildlife Management Study – Project 2: Evaluating production of moist soil plants in the Mississippi River Flood Plain and their subsequent use by waterfowl

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Wildlife Management Study - Project No. 2 dated May 15, 1969 was developed to evaluate the production of moist soil food plants in the Mississippi River flood...

  1. Silt deposit characteristics and trend analysis of torrential flood debris flows in Qionghai Lake, Xichang, China%邛海山洪泥石流淤积特征与趋势分析

    Institute of Scientific and Technical Information of China (English)

    何杰; 邓虎; 胡桂胜

    2012-01-01

    通过流域最典型支流官坝河山洪泥石流堆积特征调查,分析邛海泥沙淤积变化状况,探讨邛海山洪泥石流淤积特征以及发展趋势.结果表明,1950年以来,邛海泥沙淤积达到0.52×106 m3;山洪泥石流携带的泥沙堆积特征为粗颗粒(粒径>2 mm)沿沟床堆积,细颗粒大多被输移到邛海;山洪泥石流形成的堆积扇促使邛海湖岸线向湖心不断推进;邛海流域山洪泥石流潜入邛海湖底,形成浊流在湖底继续运动,形成湖底水下堤及冲沟,改变邛海湖底地形.在强地震和强降雨等多因素的偶然联合作用下,邛海流域可能会发生大规模的山洪泥石流.%This paper investigates the accumulation characters of the debris flows of the flash floods in the most typical tributaries in the Qionghai basin of Guanba river, Sichuan, China, analyses the changes of silt deposit in Qionghai, and explores the deposit characters and development trend. Based on this, the authors draw the following conclusions. Firstly, since 1950, 520 thousand cubic silt have deposited in Qionghai. Secondly, the deposit character of silt carried by debris flows of flash flood is that coarse particles (diameter >2 mm) accumulate along the ditch bed, while the fine particles are transported to Qionghai. Thirdly, the depositional fan formed by debris flows of flash flood impels the Qionghai lake shoreline to push on to the lake core constantly. Fourthly, the debris flows of flash flood sneak into the sublacustrine, forming the turbidity current in the lake and continuing to move, as well as forming sublacustrine underwater embankments to change the sublacustrine topography. Finally, with the combining effects of strong earthquakes, rainfalls and other causal factors, large-scale debris flows of flash flood may take place in Qionghai.

  2. Time-integrated 3D approach of late Quaternary sediment-depocenter migration in the Tagus depositional system: From river valley to abyssal plain

    NARCIS (Netherlands)

    Vis, G.J.; Kasse, C.; Kroon, D.; Vandenberghe, J.; Jung, S.; Lebreiro, S.M.; Rodrigues, T.

    2016-01-01

    Quantification of sediment volumes in continental to deep ocean basins is key to understanding processes of sediment distribution in source-to-sink depositional systems. Using our own and published data we present the first quantification of sediment-volume changes in basins along the course of a ma

  3. Contamination of the alluvial plain, feeding-stuffs and foodstuffs with polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs) and mercury from the River Elbe in the light of the flood event in August 2002.

    Science.gov (United States)

    Stachel, B; Christoph, E H; Götz, R; Herrmann, T; Krüger, F; Kühn, T; Lay, J; Löffler, J; Päpke, O; Reincke, H; Schröter-Kermani, C; Schwartz, R; Steeg, E; Stehr, D; Uhlig, S; Umlauf, G

    2006-07-01

    Meadow soils, feeding-stuffs and foodstuffs from the alluvial plain of the river Elbe were analyzed in respect of PCDD/Fs, DL-PCBs and mercury with a view to assessing the consequences of the extreme flood of August 2002. The PCDD/F concentrations in the soils range from 3 to 2100 ng WHO-TEQ/kg dm, and for the DL-PCBs the range was 0.32 to 28 ng WHO-TEQ/kg dm. On the basis of established threshold values >40% of the areas are only fit for restricted usage. Mercury concentrations range from 0.11 to 17 mg/kg dm, whereby the action value of 2 mg/kg dm is exceeded in about 50% of the soil samples. A cumulative memory effect from past floods rather than a recent contamination from August 2002 is documented. Soils taken from behind broken dykes showed significantly lower concentrations. Grass, hay and grass silage originating from pasture land in Lower Saxony were taken before and immediately after the flooding. PCDD/Fs range from 0.29 to 16 ng WHO-TEQ/kg, the maximum permitted value of 0.75 ng WHO-TEQ/kg was exceeded in about 50% of the samples. Muscle-tissue from cattle, sheep, lamb and a roe deer as well as untreated milk from individual cows returned values ranging from 0.76 to 5.9 pg WHO-PCDD/F-TEQ/g fat, and 10% of the samples returned values higher than the permitted maximum of 3 pg WHO-PCDD/F-TEQ/g fat. The action value of 2 pg WHO-PCDD/F-TEQ/g fat was exceeded in 33% of the samples. No direct connection between these results and the effects of the flood could be established. A major input path for PCDD/Fs is the tributary Mulde, which discharges contaminated sediments from its catchment area into the Elbe.

  4. FLOOD RISK MANAGEMENT IN LARGE RIVER SYSTEMS——GERMAN EXPERIENCES(IN BRIEF)%大河系统洪水风险管理——德国的经验(论文摘编)

    Institute of Scientific and Technical Information of China (English)

    WERNER Buck

    2006-01-01

    @@ Problems with extreme floods have been aggravated in Germany mainly due to loss of flood retaining areas caused by river regulation measures in former centuries, and by intensified use of the former natural flood plains.

  5. Flood damage assessment – Literature review and recommended procedure

    DEFF Research Database (Denmark)

    Olesen, Lea; Löwe, Roland; Arnbjerg-Nielsen, Karsten

    The assessment of flood risk is an essential tool in evaluating the potential consequences of a flood. The analysis of the risk can be applied as part of the flood plain management, but can also be used in a cost-benefit analysis, when comparing different adaption strategies. This analysis...... is therefore important when assessing flood disaster mitigation options and economical optimizations of possible measures. A common definition is that the flood risk is found with the use of a flood hazard assessment and a flood vulnerability assessment (Apel, Merz and Thieken, 2008). The flood hazard...... is the quantification of amount, extent, and location of flooding expected to occur with a given return period. This means that the spatial distribution of the calculated inundation depth as a function of the return period can be used to describe the flood hazard. The vulnerability is the susceptibility of the area...

  6. Sources and paleoclimatic significance of Holocene Bignell Loess, central Great Plains, USA

    Science.gov (United States)

    Mason, Joseph A.; Jacobs, Peter M.; Hanson, Paul R.; Miao, Xiaodong; Goble, Ronald J.

    2003-11-01

    This paper reexamines the stratigraphy, sources, and paleoclimatic significance of Holocene Bignell Loess in the central Great Plains. A broadly similar sequence of loess depositional units and paleosols was observed in thick Bignell Loess sections up to 300 km apart, suggesting that these sections record major regional changes in the balance between dust deposition and pedogenesis. New optical ages, together with previously reported radiocarbon ages, indicate Bignell Loess deposition began 9000-11,000 yr ago and continued into the late Holocene; some Bignell Loess is <1000 yr old. There is little evidence that Holocene Loess was derived from flood plain sources, as previously proposed. Instead, thick Bignell Loess occurs mainly near the downwind margins of inactive dune fields, particularly atop escarpments facing the dunes. Thus, the immediate loess source was dust produced when the dunes were active. Previous work indicates that widespread episodes of dune activity are likely to have resulted from drier-than-present climatic conditions. The regionally coherent stratigraphy of Bignell Loess can be interpreted as a near-continuous record of climatically driven variation in dune field activity throughout the Holocene.

  7. Characteristics of alleviating the over-exploitation and its recharge on the rainstorm flood to the shallow groundwater in the southern plain of Haihe River basin%暴雨洪水对地下水超采缓解特征与资源增量

    Institute of Scientific and Technical Information of China (English)

    张光辉; 费宇红; 田言亮; 王茜; 严明疆

    2015-01-01

    Aiming at the problem of alleviating the decline trend of the shallow groundwater level with the recharging rainstorm flood, a case in early August of 1996 in the southern plain of the Haihe River basin where the groundwater is serious in the over exploitation. The variation characteristics of the shallow ground⁃water level and its trend in different period were studied by using the time series variation characteristics method and the trend analysis method based on the monthly groundwater level dynamic data and the precip⁃itation observed data in this area. The results show that:(1) Storm floods similar to that of 1996 have dis⁃tinct effect in alleviating the over-exploitation trend of the shallow groundwater in the southern plain of the Haihe River basin, and is the indispensable supply mode in the balance of groundwater under the plain, which recharged 69~107 million m3 per 100 km2 to the groundwater during the big flood in 1996;(2) The main recharge process of the flooding to the groundwater occurs in the river channel and low-lying flood-prone areas in the alluvial plain, presenting linear and sheet infiltration and recharge features with natural attribute;and (3) The shallow groundwater levels continue to decline is related to the reduction of the groundwater recharge source in the plain during the past 30 years. Therefore, to ensure the rainstorm flood recharging to the groundwater should be an important approach in alleviating the over-exploitation situ⁃ation of the regional groundwater in the plain.%针对暴雨洪水对超采区浅层地下水位不断下降趋势的缓解作用问题,以海河南系平原“96.8”暴雨洪水为例,采用时间序列异变特征和趋势分析方法,基于该区逐月地下水位动态长观资料和降水资料,通过对暴雨洪水主要区域的浅层地下水位急剧变化特征和不同时段变化趋势研究,结果表明:(1)类似“96.8”的暴雨洪水对减缓海河南系平原区浅

  8. Distribution and Mobilization of Arsenic in the Ganges plain sedimentary deposits of South-western Bangladesh; implications from field and laboratory observations

    Science.gov (United States)

    Rahman, M.; Mano, A.; Udo, K.; Ishibashi, Y.; Han, Y.

    2011-12-01

    The variation of arsenic concentration depending on sediment size and its depositional age in a variety of sediments extracted from four As contaminated sites of the southwestern Bangladesh were studied to elucidate the aquifer geological parameters that controls the vertical As distribution and mobilization in the sediment-water interface. It was found that sediment size, reactive surface area, relative depositional age and presence of other carrier minerals having higher affinity to adsorb As, may greatly dominate the arsenic accumulation. Sorption of As onto sediment surfaces was found to vary based on the variation of the particle diameters (2 to 250 μm), which eventually reflects the role of geological materials in controlling the As distribution in various depositional layers. Medium sands commonly found in the deeper aquifer (~150m), being older in age (> 7000 yrs BP) and having relatively larger diameter (φ~250 μm) were found to contain relatively low amount of As (0.8 μg/g) whereas higher As (5 to 25 μg/g) was identified noticeably in the recently deposited and reasonably younger (100 to 1000 yrs BP) sediment particles including clay and finer sands that commonly have moderately smaller diameter (φ~2 to 90 μm). These observations were supported strongly by the findings obtained from the laboratory batch adsorption tests conducted with those sediments. Presence of As was also observed to be greatly dependent on the availability of its carrier minerals particularly Fe and Al oxide/hydroxide along the aquifer depths. Clay particles with relatively moderate Fe and Al oxide minerals was found to adsorb as much as 70 μg/g As whereas medium sand with less Fe and Al oxide minerals were noticed to capture only 4 μg/g of As in the batch adsorption test. In laboratory leaching test, significant amount of As (12 μg/g) coupled with Fe (4.8 mg/g) were found to be leached out from the shallower brown clay by using sodium bicarbonate (pH~9) as the leaching agent

  9. 3-D hydrodynamic modelling of flood impacts on a building and indoor flooding processes

    Science.gov (United States)

    Gems, Bernhard; Mazzorana, Bruno; Hofer, Thomas; Sturm, Michael; Gabl, Roman; Aufleger, Markus

    2016-06-01

    Given the current challenges in flood risk management and vulnerability assessment of buildings exposed to flood hazards, this study presents three-dimensional numerical modelling of torrential floods and its interaction with buildings. By means of a case study application, the FLOW-3D software is applied to the lower reach of the Rio Vallarsa torrent in the village of Laives (Italy). A single-family house on the flood plain is therefore considered in detail. It is exposed to a 300-year flood hydrograph. Different building representation scenarios, including an entire impervious building envelope and the assumption of fully permeable doors, light shafts and windows, are analysed. The modelling results give insight into the flooding process of the building's interior, the impacting hydrodynamic forces on the exterior and interior walls, and further, they quantify the impact of the flooding of a building on the flow field on the surrounding flood plain. The presented study contributes to the development of a comprehensive physics-based vulnerability assessment framework. For pure water floods, this study presents the possibilities and limits of advanced numerical modelling techniques within flood risk management and, thereby, the planning of local structural protection measures.

  10. Contrasting alluvial architecture of Late Pleistocene and Holocene deposits along a 120-km transect from the central Po Plain (northern Italy)

    Science.gov (United States)

    Campo, Bruno; Amorosi, Alessandro; Bruno, Luigi

    2016-07-01

    High-resolution investigation of a ~ 120-km-long transect along the course of the modern Po River, northern Italy, revealed marked changes in alluvial architecture across the Pleistocene-Holocene boundary. Along the whole transect, a 20- to 30-m thick sheet-like succession of Late Pleistocene fluvial sands is invariably overlain by silt and clay deposits, with isolated fluvial bodies of Holocene age (architecture: well-drained floodplain deposits are transitional at distal locations to increasingly organic, poorly drained floodplain to swamp facies associations. Thick paludal facies extend continuously up to 60 km landward of the Holocene maximum marine ingression, about 90 km from the modern shoreline. Based on 28 radiocarbon dates, the abrupt change in lithofacies and channel stacking pattern occurred at the transition from the last glacial period to the present interglacial, under conditions of rapid sea-level rise. The architectural change from amalgamated, Late Pleistocene sand bodies to overlying, mud-dominated Holocene units represent an example of chronologically well-constrained fluvial response to combined climate and relative sea-level change. The overall aggradational stacking pattern of individual channel-belt sand bodies indicates that high subsidence rates continuously created accommodation in the Po Basin, even during phases of falling sea level and lowstand.

  11. Landscape gradients and patchiness in riparian vegetation on a Middle Pennsylvanian braided-river plain prone to flood disturbance (Nýrany Member, Central and Western Bohemian Basin, Czech Republic)

    DEFF Research Database (Denmark)

    Bashforth, Arden Roy; Drábková, Jana; Opluštil, Stanislav;

    2011-01-01

    to avulsion and flooding. Taphonomic observations and multivariate analysis of 41 quadrats containing mostly (par)autochthonous megafloral assemblages reveal that riparian vegetation comprised a collage of monospecific to low-diversity communities, with patchiness prevalent at local and regional scales...

  12. Changes in the Ways of Social Response to Floods and Droughts in Nouth China Plain during1780~1819%1780-1819年华北平原水旱灾害社会响应方式的转变

    Institute of Scientific and Technical Information of China (English)

    萧凌波; 方修琦; 黄欢

    2011-01-01

    Reconstruction of cases about how human society responded to floods and droughts in history would be instructive for current research on adaptation to climate changes.Based on historical documents and climate change research, 4 typical disasters (droughts in 1785, 1792, 1813; flood in 1801 ) in North China Plain during 1780 ~ 1819 are selected.With proxy indexes describing disaster situation, governmental disaster relief and victims' behavior, they are quantitatively reconstructed and compared with each other.The results are as follows.( 1 ) Relief density index ( quantity of relief supplies/affected counties) successively decreased in the 4 disasters, from 3.59 in 1785 to 0.56 in 1813, which means governmental disaster relief had been crippled in the period.(2) Victims' behavior was gradually lost of control, from upsurge of emigration in 1792 and 1801 to armed uprising in 1813.The transformation occurred as a result of negative interaction between government and civilians, under the pressure of abrupt climate change, overpopulation, and financial crisis in corresponding period.

  13. Landscape gradients and patchiness in riparian vegetation on a Middle Pennsylvanian braided-river plain prone to flood disturbance (Nýrany Member, Central and Western Bohemian Basin, Czech Republic)

    DEFF Research Database (Denmark)

    Bashforth, Arden Roy; Drábková, Jana; Opluštil, Stanislav

    2011-01-01

    and conglomerate dominate at the four localities studied, but fine-grained intercalations, representing abandoned channels, floodplains, and shallow lakes, yielded rich megafloral and palynological assemblages. Sedimentological evidence indicates that high-energy flow characterized a braided-river plain prone......, and ephemeral mires on distal floodplains. The heterogeneous distribution of riparian plants is consistent with that of modern, disturbance-dominated fluvial environments, although Pennsylvanian species richness was much lower. A review of floristic patterns in latest Middle Pennsylvanian vegetation...

  14. The effect of the "Great Flood of 1993" on subsequent suspended sediment concentrations and fluxes in the Mississippi River Basin, USA

    Science.gov (United States)

    Horowitz, A.J.

    2006-01-01

    During the spring/summer of 1993, the upper Midwestern USA experienced unusually heavy precipitation (200-350% above normal). More than 500 gauging stations in the region were simultaneously above flood stage, and nearly 150 major rivers and tributaries over-topped their banks. This was one of the costliest floods in the history of the USA, and came to be known as the "Great Flood of 1993". An examination of the long-term daily sediment record for the Mississippi River at Thebes, Illinois (representing the middle, or lower part of the upper basin), indicates that the flood had a severe and long-lasting impact on subsequent suspended sediment concentrations (SSC) and annual suspended sediment fluxes in the basin. At Thebes, pre1993 (1981-1992) median discharge and SSC were about 5400 m3 s-1 and 304 mg L-1, respectively; whereas, post-1993 (1994-2004) median discharge and SSC were about 5200 m3 s-1 and 189 mg L-1, respectively. Clearly, the 1993 flood removed substantial amounts of "stored" bed sediment and/or readily erodible flood plain deposits, eliminating a major source of SSC for the Thebes site. Examination of additional, but discontinuous sediment records (covering the period from 1981-2004) for other sites in the basin indicates that current post-flood declines in SSC and suspended sediment fluxes range from a low of about 10% to a high of about 36%.

  15. CO2驱油中沥青质沉积条件及对驱油效果影响的研究%The Study on Depositional Condition of Bitumen and Displacement Characteristics Effect of CO2 Flooding

    Institute of Scientific and Technical Information of China (English)

    赵明国; 赵宇

    2011-01-01

    Reservoir conditions in Yushulin Oil field, through PVT Parameters and CO2 flooding experiments is simulated. The depositional condition of bitumen after CO2 injection is studied and analyzd the displacement characteristics of CO2 flooding on the effect of bitumen deposition. The results show that: at the reservoir temperature (108℃), the bitumen deposition is appeared when the injection pressure reaches 28.4 MPa, with the temperature increases, the pressure of the formation of bitumen deposition and the degree of bitumen deposition increases; with the pressure of CO2 injection increase, the bitumen deposition increases, and the bitumen in the crude oil decreased, the content of colloid, aromatics, saturated hydrocarbon increased, after the pressure of CO2 injection reach 28 MPa, the content of bitumen deposition decreased, the bitumen content of recovery oil increased. Bitumen deposition reduce the recovery ratio of 12.29% and the recovery ratio decrease sharpest when the injection pressure of 25-28 MPa.%在模拟榆树林油田地层条件下,通过高压物性及CO2驱油实验,研究了注CO2后沥青质的沉积条件,并对沥青质沉积对CO2驱油效果的影响进行了分析.结果表明:在地层温度(108℃)下,注气压力达到28.4 MPa时可明显出现沥青质沉积.随着温度增加,形成沥青质沉积的压力增加,沥青质沉积的程度增加;随CO2注入压力的增加,沥青质沉积量增加,原油中的沥青质含量降低,胶质、芳烃、饱和烃含量增加;达到28 MPa后沥青质沉积量逐渐减少,采出油中沥青质含量增加.沥青质沉积使采收率降低12.29%以上,在(25-28) MPa时采收率降低幅度最大.

  16. Prediction of intermittent claudication, ischemic stroke, and other cardiovascular disease by detection of abdominal aortic calcific deposits by plain lumbar radiographs.

    Science.gov (United States)

    Levitzky, Yamini S; Cupples, L Adrienne; Murabito, Joanne M; Kannel, William B; Kiel, Douglas P; Wilson, Peter W F; Wolf, Philip A; O'Donnell, Christopher J

    2008-02-01

    There has been little attention to vascular calcium testing for generalized assessment of cardiovascular disease (CVD) outcomes, such as intermittent claudication (IC) and ischemic stroke (IS). We hypothesize that aortic calcium is an important predictor of CVD outcomes. Lumbar x-rays were obtained in 848 men and 1,301 women (mean ages 59.7 and 60.1 years, respectively) from the original cohort of the Framingham Heart Study. Abdominal aortic calcium (AAC) deposits were graded using a previously validated scale. Participants were categorized according to a 10-year Framingham coronary heart disease (CHD) risk score. Multivariable Cox proportional hazards analyses were performed to relate AAC to CVD outcomes. There were 199 IC events, 201 IS events, 702 CHD events, and 1,121 CVD events during 32 years of follow-up. Multivariable adjusted hazard ratios for the third versus first AAC tertile in the combined cohort were 1.68 (95% confidence interval [CI] 1.12 to 2.50) for IC, 1.73 (95% CI 1.12 to 2.65) for IS, 1.59 (95% CI 1.26 to 2.00) for CHD, and 1.64 (95% CI 1.37 to 1.97) for CVD. Hazard ratios for IC and IS were similar in magnitude to those for CHD and CVD. A high AAC score was associated with significantly higher incidence of events in subjects at intermediate Framingham CHD risk for all end points. Risk prediction based on cardiovascular risk factors improved for most outcomes when AAC was added. In conclusion, there was a graded, increasing, and independent association of AAC with incident IC and IS, similar in magnitude to risks predicted for CHD and CVD. AAC appears to be useful for risk stratification in patients at intermediate CHD risk.

  17. Flood resilience urban territories. Flood resilience urban territories.

    Science.gov (United States)

    Beraud, Hélène; Barroca, Bruno; Hubert, Gilles

    2010-05-01

    flood but also to restart as fast as possible (for example, the clearing of roads is a prerequisite for electricity's restoration which is a vital network for territory's functioning). While the waste management is a main stage of post crisis, these questions are still without answer. The extend of this network influence also leads us to think about the means to prevent from waste production and service's dysfunction. How to develop the territory to limit the floods' impact on the waste management network? Are there techniques or equipments allowing stakeholders to limit these impacts? How to increase population's, entrepreneur's or farmer's awareness to get ready to face floods, to limit the waste production, but also to react well during and after the floods? Throughout means of prevention and thanks to actor's technical and organizational adaptations towards the waste network, or by raising population's awareness and preparation, economic and institutional actors of urban territories might improve the waste's network flood resilience, and thus, cities' flood resilience. Through experience feedbacks about countries recently affected by large-extended floods and field reflection with local actors, the stakes of this PhD research are thus to think about means (1) to maintain the activity out of flood plains during a flood, (2) to increase the waste management network's activity in post crisis period in order to be able to deal with a new waste production both by its quality and its quantity, but also (3) to study the means to prevent this new production. This work will use the concept of urban system to describe urban territory because it allows us to study both its behaviour and functioning. The interest of this methodological choice is to take into account the impacts of the disruption of waste management networks on cities' functioning, and thus, on cities' flood resilience.

  18. Techniques for estimating magnitude and frequency of floods for Wisconsin streams

    Science.gov (United States)

    Conger, Duane H.

    1981-01-01

    This report provides improved methods for estimating the magnitude and frequency of floods for Wisconsin streams. Proper design of hydraulic structures and adequate flood-plain management depend on this information. Multiple-regression techniques were used to develop equations for estimating flood frequencies at ungaged sites.

  19. Pre-and post-Missoula flood geomorphology of the Pre-Holocene ancestral Columbia River Valley in the Portland forearc basin, Oregon and Washington, USA

    Science.gov (United States)

    Peterson, Curt D.; Minor, Rick; Peterson, Gary L.; Gates, Edward B.

    2011-06-01

    Geomorphic landscape development in the pre-Holocene ancestral Columbia River Valley (1-5 km width) in the Portland forearc basin (~ 50 km length) is established from depositional sequences, which pre-date and post-date the glacial Lake Missoula floods. The sequences are observed from selected borehole logs (150 in number) and intact terrace soil profiles (56 in number) in backhoe trenches. Four sequences are widespread, including (1) a vertically aggraded Pleistocene alluvial plain, (2) a steep sided valley that is incised (125-150 m) into the Pleistocene gravel plain, (3) Missoula flood terraces (19-13 ka) abandoned on the sides of the ancestral valley, and (4) Holocene flooding surfaces (11-8 ka) buried at 70-30 m depth in the axial Columbia River Valley. Weathering rims and cementation are used for relative dating of incised Pleistocene gravel units. Soil development on the abandoned Missoula flood terraces is directly related to terrace deposit lithology, including thin Bw horizons in gravel, irregular podzols in sand, and multiple Bw horizons in thicker loess-capping layers. Radiocarbon dating of sand and mud alluvium in the submerged axial valley ties Holocene flooding surfaces to a local sea level curve and establishes Holocene sedimentation rates of 1.5 cm year- 1 during 11-9 ka and 0.3 cm year- 1 during 9-0 ka. The sequences of Pleistocene gravel aggradation, river valley incision, cataclysmic Missoula flooding, and Holocene submergence yield complex geomorphic landscapes in the ancestral lower Columbia River Valley.

  20. 100 years of mapping the Holocene Rhine-Meuse delta plain: combining research and teaching

    NARCIS (Netherlands)

    Cohen, K. M.; Stouthamer, E.; Hoek, W. Z.; Middelkoop, H.

    2012-01-01

    The history of modern soil, geomorphological and shallow geological mapping in the Holocene Rhine-Meuse delta plain goes back about 100 years. The delta plain is of very heterogeneous build up, with clayey and peaty flood basins, dissected by sandy fluvial distributary channel belts with fine textur

  1. Monsoon sedimentation on the ‘abandoned' tide-influenced Ganges-Brahmaputra delta plain

    Science.gov (United States)

    Rogers, Kimberly G.; Goodbred, Steven L.; Mondal, Dhiman R.

    2013-10-01

    Annual sediment delivery by the Ganges and Brahmaputra rivers to the Bengal margin has kept pace with sea level rise since the mid Holocene, sustaining subaerial growth of the delta. However, the Sundarbans region of the tidal delta is disconnected from major distributary sources of sediment and is often thought to be sediment starved, eroding, and susceptible to the meter of sea level rise predicted for the 21st century. Despite these assumptions, direct sedimentation measurements on the tidal delta plain reveal widespread mean annualized accretion rates of ˜1.1 cm yr-1, although heterogeneous depositional patterns indicate that topography and internal creek networks influence local sediment distribution. Short-lived radioisotope inventories (7Be: t1/2 = 53.3 days) measured on the freshly accumulated sediments indicate that about ½ of the mass deposited on the lower delta was sourced directly from the seasonal flood pulse of the river; the remaining ½ is derived from older (≥1 yr) reworked sediments. Net sedimentation on this part of the delta traps ˜10% of annual Ganges-Brahmaputra sediment load, with accretion rates roughly equivalent to the mean regional rate of relative sea-level rise (RSLR) of ˜1.0 cm yr-1. If these sedimentation rates are representative of longer-term trends and subsidence rates remain stable over the next century, the lower delta plain may continue to maintain its elevation and stability despite documented mangrove retreat around its seaward edges.

  2. Flood Mitigation of Nyando River Using Duflow Modelling

    Directory of Open Access Journals (Sweden)

    J. Joleha

    2009-01-01

    Full Text Available Duflow surface water hydrodynamic model has been applied using a case study from Nyando catchment in the western part of Kenya in Africa to simulate various extreme flood behaviours and their retardation levels by using selected structural measures as flood mitigation techniques. The objective of this case study was to establish a design flood recommendable for mitigation, and to identify the most cost effective flood mitigation structure. Various design flows are simulated against the different proposed structures hence, the optimal structure can be recommended when economical, social and environmental constraints are considered in the decision making process. The proposed four flood mitigation structures flood plain extension, embankment (dykes, channel by-pass, and green-storage were simulated for 20-year recurrence interval flood to determine their individual responses in storing excess water. The result shows that building a green-storage is the best and optimal structure for flood mitigation.

  3. Stream-sediment geochemistry in mining-impacted streams : sediment mobilized by floods in the Coeur d'Alene-Spokane River system, Idaho and Washington

    Science.gov (United States)

    Box, Stephen E.; Bookstrom, Arthur A.; Ikramuddin, Mohammed

    2005-01-01

    Environmental problems associated with the dispersion of metal-enriched sediment into the Coeur d'Alene-Spokane River system downstream from the Coeur d'Alene Mining District in northern Idaho have been a cause of litigation since 1903, 18 years after the initiation of mining for lead, zinc, and silver. Although direct dumping of waste materials into the river by active mining operations stopped in 1968, metal-enriched sediment continues to be mobilized during times of high runoff and deposited on valley flood plains and in Coeur d'Alene Lake (Horowitz and others, 1993). To gauge the geographic and temporal variations in the metal contents of flood sediment and to provide constraints on the sources and processes responsible for those variations, we collected samples of suspended sediment and overbank deposits during and after four high-flow events in 1995, 1996, and 1997 in the Coeur d'Alene-Spokane River system with estimated recurrence intervals ranging from 2 to 100 years. Suspended sediment enriched in lead, zinc, silver, antimony, arsenic, cadmium, and copper was detected over a distance of more than 130 mi (the downstream extent of sampling) downstream of the mining district. Strong correlations of all these elements in suspended sediment with each other and with iron and manganese are apparent when samples are grouped by reach (tributaries to the South Fork of the Coeur d'Alene River, the South Fork of the Coeur d'Alene River, the main stem of the Coeur d'Alene River, and the Spokane River). Elemental correlations with iron and manganese, along with observations by scanning electron microscopy, indicate that most of the trace metals are associated with Fe and Mn oxyhydroxide compounds. Changes in elemental correlations by reach suggest that the sources of metal-enriched sediment change along the length of the drainage. Metal contents of suspended sediment generally increase through the mining district along the South Fork of the Coeur d'Alene River, decrease

  4. 2 Dimensional Hydrodynamic Flood Routing Analysis on Flood Forecasting Modelling for Kelantan River Basin

    Directory of Open Access Journals (Sweden)

    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.

  5. Flood Hazard Mapping using Hydraulic Model and GIS: A Case Study in Mandalay City, Myanmar

    Directory of Open Access Journals (Sweden)

    Kyu Kyu Sein

    2016-01-01

    Full Text Available This paper presents the use of flood frequency analysis integrating with 1D Hydraulic model (HECRAS and Geographic Information System (GIS to prepare flood hazard maps of different return periods in Ayeyarwady River at Mandalay City in Myanmar. Gumbel’s distribution was used to calculate the flood peak of different return periods, namely, 10 years, 20 years, 50 years, and 100 years. The flood peak from frequency analysis were input into HEC-RAS model to find the corresponding flood level and extents in the study area. The model results were used in integrating with ArcGIS to generate flood plain maps. Flood depths and extents have been identified through flood plain maps. Analysis of 100 years return period flood plain map indicated that 157.88 km2 with the percentage of 17.54% is likely to be inundated. The predicted flood depth ranges varies from greater than 0 to 24 m in the flood plains and on the river. The range between 3 to 5 m were identified in the urban area of Chanayetharzan, Patheingyi, and Amarapua Townships. The highest inundated area was 85 km2 in the Amarapura Township.

  6. Geochronology and Geomorphology of the Pioneer Archaeological Site (10BT676), Upper Snake River Plain, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Keene, Joshua L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-01

    The Pioneer site in southeastern Idaho, an open-air, stratified, multi-component archaeological locality on the upper Snake River Plain, provides an ideal situation for understanding the geomorphic history of the Big Lost River drainage system. We conducted a block excavation with the goal of understanding the geochronological context of both cultural and geomorphological components at the site. The results of this study show a sequence of five soil formation episodes forming three terraces beginning prior to 7200 cal yr BP and lasting until the historic period, preserving one cultural component dated to ~3800 cal yr BP and multiple components dating to the last 800 cal yr BP. In addition, periods of deposition and stability at Pioneer indicate climate fluctuation during the middle Holocene (~7200-3800 cal yr BP), minimal deposition during the late Holocene, and a period of increased deposition potentially linked to the Little Ice Age. In addition, evidence for a high-energy erosion event dated to ~3800 cal yr BP suggest a catastrophic flood event during the middle Holocene that may correlate with volcanic activity at the Craters of the Moon lava fields to the northwest. This study provides a model for the study of alluvial terrace formations in arid environments and their potential to preserve stratified archaeological deposits.

  7. Flooding On

    Institute of Scientific and Technical Information of China (English)

    YIN PUMIN

    2010-01-01

    @@ Drenched riverside towns in central and south parts of China were preparing for even worse flooding as water levels in the country's huge rivers surged and rainstorms continued. As of July 27,accumulated precipitation since June 16 in 70 percent of the drainage areas of the Yangtze River had exceeded 50 mm,after three rounds of rainstorms,said Cai Qihua,Deputy Director of the Yangtze River Flood Control and Drought Relief Headquarters.

  8. Sequence stratigraphy and depositional systems in the Paleogene, Liaodong Bay

    Institute of Scientific and Technical Information of China (English)

    Ji Hancheng

    2008-01-01

    Based on drilling and seismic data,the Paleogene developed in Liaodong Bay can be divided into five third-order sequences bounded by six sequence boundaries.Through analyzing depositional systems in each sequence in detail,the Es-3 time was defined as fast rifting.During the deposition of the Es-3 member,the lake basin was continuous along the N-S direction but compartmentalized along the E-W direction by several N-S trending faults.Deposition was dominated by steep slope fans and fan deltas.The time of Es-2 and Es-1 was stable settling.The lake basin expanded substantially.The fan delta system and braided fluvial system were developed.Carbonate and clastic deposits were formed on the Liaoxi (west Liaohe) Rise.The time of Ed-3 time was again fast rifting.During this time,shale was deposited.In the time of Es-2,tectonic movement weakened.The basin was higher in the west and north,and lower in the east and south.A series of delta depositionai systems were developed and smallscale slumping turbidite fans were present in semi-deep lake to deep lake.In the time of Ed-1,tectonic movement stopped.Flood plain deposition occurred.Finally the paper presents the characteristics of evolution and distribution of depositional systems both vertically and horizontally.

  9. Decision Support for Flood Event Prediction and Monitoring

    DEFF Research Database (Denmark)

    Mioc, Darka; Anton, François; Liang, Gengsheng

    2007-01-01

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

  10. The pattern of spatial flood disaster region in DKI Jakarta

    Science.gov (United States)

    Tambunan, M. P.

    2017-02-01

    in beach ridge, coastal alluvial plain, and alluvial plain; while the flood potential area on the slope is found flat and steep at alluvial fan, alluvial plain, beach ridge, and coastal alluvial plain in DKI Jakarta. Based on the result can be concluded that actual flood prone is not distributed on potential flood prone

  11. Sedimentary facies of Maastrichtian to Danian deposits in Amur River area, Russian Far East

    Institute of Scientific and Technical Information of China (English)

    Shigeyuki Suzuki; Abdul R. Ashraf; Hakuyu Okada

    2004-01-01

    Sedimentary facies of the Tsagayan Formation is distributed in the eastern Zeya-Bureya Basin has been analyzed. The formation is of the Maastrichtian to Danian in age and characterized by the cyclicity of the fining-upwards successions. Analysis of environmental changes during the K/T boundary is the focus of this study. Five facies have been identified: Facies A, thick and laterally extensive coarse-grained to medium-grained sandstone units, interpreted as channelfill deposits; Facies B, parallel-laminated to massive mudstone units interpreted as interchannel lakes and flood plain deposits; Facies C, sheet-like medium-grained to fine-grained sandstones interpreted as crevasse splay deposits;Facies D, coal to coaly mudstone beds interpreted as deposits ofpeatlands; Facies E, very poorly sorted sandy mudstone beds interpreted as debris flow deposits. Fluvial environments with the low-relief flat topography was inferred. A channel transported large volumes of clasts, and a flood basin with interchannel lakes and peatlands was deciphered. Any distinct change of sedimentary environments has not been identified throughout the Tsagayan Formation (including the K/T boundary). However, two beds of debris flow deposits were identified. The one occurs at the uppermost part of the lower Tsagayan Subformation and contains dinosaur fossils. The other is intercalated in the upper Tsagayan Subformation.

  12. Combating Floods

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    In summer and autumn of 1998, the river vatleys of the Changjiang, Songhua and Nenjiang rivers were stricken by exceptionally serious floods, As of the, 22nd of August, the flooded areas stretched over 52.4 million acres. More than 223 million people were affected by the flood. 4.97 million houses were ruined, economic losses totaled RMB 166 billion, and most tragically, 3,004 people lost their byes. It was one of the costliest disasters in Chinese history. Millions of People’s Liberation Army soldiers and local people joined hands to battle the floodwaters. Thanks to their unified efforts and tenacious struggle, they successfully withstood the rising, water, resumed production and began to rebuild their homes.

  13. Dinosaur egg deposits in the Cretaceous Gyeongsang Supergroup, Korea: Diversity and paleobiological implications

    Science.gov (United States)

    Paik, In Sung; Kim, Hyun Joo; Huh, Min

    2012-08-01

    The taphonomy and depositional environments of dinosaur-egg-bearing deposits in the Cretaceous Gyeongsang Basin, Korea, are described and their paleobiological implications are discussed in the context of global geographic occurrences, geological ages, paleoenvironments, and lithology. The general depositional environment of dinosaur egg deposits in the Gyeongsang Supergroup is interpreted as dry floodplains with a semi-arid climate and intermittent volcanic activity. The diverse floodplain paleoenvironments include fluvial plains with meandering rivers to alluvial plains with episodic sheet-flooding. Both global and Korean dinosaur-egg-bearing deposits are generally restricted to the Late Cretaceous, a phenomenon for which two possible explanations are proposed. The first possible explanation for the temporal limitation of dinosaur egg preservation involves the appearance of angiosperms in the Late Jurassic, the Late Cretaceous ecological dispersion of angiosperm trees into swamps and floodplains, and the attendant change in herbivorous dinosaurs' diets. The second possible reason is related to nesting behavior in the Cretaceous. By contrast to the temporally limited occurrence of dinosaur eggs, paleoenvironments of nesting areas are diverse, ranging from inland areas to coastal areas. These hypotheses may provide new directions for the study and understanding of dinosaur egg distribution in the context of geologic time.

  14. Atmosphere-Land-Surface Interaction over the Southern Great Plains: Diagnosis of Mechanisms from SGP ARM Data

    Energy Technology Data Exchange (ETDEWEB)

    Sumant Nigam

    2013-02-01

    Work reported included analysis of pentad (5 day) averaged data, proposal of a hypothesis concerning the key role of the Atlantic Multi-decadal Oscillation in 20th century drought and wet periods over the Great Plains, analysis of recurrent super-synoptic evolution of the Great Plains low-level jet, and study of pentad evolution of the 1988 drought and 1993 flood over the Great Plains from a NARR perspective on the atmospheric and terrestrial water balance.

  15. Flooding On

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Drenched riverside towns in central and south parts of China were preparing for even worse flooding aswater levels in the country’s huge rivers surged and rainstorms continued.As of July 27,accumulated precipitation since June 16 in 70 percent of the drainage

  16. Effects of increased flooding on riparian vegetation

    DEFF Research Database (Denmark)

    Garssen, Annemarie G.; Baattrup-Pedersen, Annette; Riis, Tenna

    2017-01-01

    In many parts of the world, the magnitude and frequency of cold-season precipitation are expected to increase in the near future. This will result in an increased magnitude and duration of winter and spring flooding by rain-fed streams and rivers. Such climate-driven increases in flooding...... of 3 years. We assessed the responses in riparian plant species richness, biomass, plant-available nitrogen and phosphorus and seed deposition to increased flooding depth (+18 cm on average at the lowest positions along the riparian gradient) and prolonged flooding duration (6 weeks on average). After...... 3 years of increased flooding, there was an overall decline in riparian species richness, while riparian plant biomass increased. Extractable soil nitrogen and phosphorus also increased and are likely to have contributed to the increased biomass. Increased flooding resulted in the arrival of more...

  17. Watershed basin management and agriculture practices: an application case for flooding areas in Piemonte.

    Science.gov (United States)

    Bianco, G.; Franzi, L.; Valvassore, U.

    2009-04-01

    Watershed basin management in Piemonte (Italy) is a challenging issue that forces the local Authorities to a careful land planning in the frame of a sustainable economy. Different and contrasting objectives should be taken into account and balanced in order to find the best or the most "reasonable" choice under many constraints. Frequently the need for flood risk reduction and the demand for economical exploitation of floodplain areas represent the most conflicting aspects that influence watershed management politics. Actually, flood plains have been the preferred places for socio-economical activities, due to the availability of water, fertility of soil and the easiness of agricultural soil exploitation. Sometimes the bed and planform profile adjustments of a river, as a consequence of natural processes, can impede some anthropogenic activities in agriculture, such as the erosion of areas used for crops, the impossibility of water diversion, the deposition of pollutants on the ground, with effects on the economy and on the social life of local communities. In these cases watershed basin management should either balance the opposite demands, as the protection of economic activities (that implies generally canalized rivers and levees construction) and the need of favouring the river morphological stability, allowing the flooding in the inundation areas. In the paper a case study in Piemonte region (Tortona irrigation district) is shown and discussed. The effects of the Scrivia river planform adjustment on water diversion and soil erodibility force the local community and the authority of the irrigation district to ask for flood protection and river bed excavation. A mathematical model is also applied to study the effects of local river channel excavation on flood risk. Some countermeasures are also suggested to properly balance the opposite needs in the frame of a watershed basin management.

  18. Simulation of Flood Profiles for Fivemile Creek at Tarrant, Alabama, 2006

    Science.gov (United States)

    Lee, K.G.; Hedgecock, T.S.

    2007-01-01

    A one-dimensional step-backwater model was used to simulate flooding conditions for Fivemile Creek at Tarrant, Alabama. The 100-year flood stage published in the current flood insurance study for Tarrant by the Federal Emergency Management Agency was significantly exceeded by the March 2000 and May 2003 floods in this area. A peak flow of 14,100 cubic feet per second was computed by the U.S. Geological Survey for the May 2003 flood in the vicinity of Lawson Road. Using this estimated peak flow, flood-plain surveys with associated roughness coefficients, and the surveyed high-water profile for the May 2003 flood, a flow model was calibrated to closely match this known event. The calibrated model was then used to simulate flooding for the 10-, 50-, 100-, and 500-year recurrence interval floods. The results indicate that for the 100-year recurrence interval, the flood profile is about 2.5 feet higher, on average, than the profile published by the Federal Emergency Management Agency. The absolute maximum and minimum difference is 6.80 feet and 0.67 foot, respectively. All water-surface elevations computed for the 100-year flood are higher than those published by the Federal Emergency Management Agency, except for cross section H. The results of this study provide the community with flood-profile information that can be used for existing flood-plain mitigation, future development, and safety plans for the city.

  19. Tsunami flooding

    Science.gov (United States)

    Geist, Eric; Jones, Henry; McBride, Mark; Fedors, Randy

    2013-01-01

    Panel 5 focused on tsunami flooding with an emphasis on Probabilistic Tsunami Hazard Analysis (PTHA) as derived from its counterpart, Probabilistic Seismic Hazard Analysis (PSHA) that determines seismic ground-motion hazards. The Panel reviewed current practices in PTHA and determined the viability of extending the analysis to extreme design probabilities (i.e., 10-4 to 10-6). In addition to earthquake sources for tsunamis, PTHA for extreme events necessitates the inclusion of tsunamis generated by submarine landslides, and treatment of the large attendant uncertainty in source characterization and recurrence rates. Tsunamis can be caused by local and distant earthquakes, landslides, volcanism, and asteroid/meteorite impacts. Coastal flooding caused by storm surges and seiches is covered in Panel 7. Tsunamis directly tied to earthquakes, the similarities with (and path forward offered by) the PSHA approach for PTHA, and especially submarine landslide tsunamis were a particular focus of Panel 5.

  20. Holocene palaeoDEMs for lowland coastal and delta plain landscape reconstructions

    Science.gov (United States)

    Cohen, Kim M.; Koster, Kay; Pierik, Harm-Jan; Van der Meulen, Bas; Hijma, Marc; Schokker, Jeroen; Stafleu, Jan

    2017-04-01

    Geological mapping of Holocene deposits of coastal plains, such as that of The Netherlands can reach high resolution (dense population, diverse applied usage) and good time control (14C dating, archaeology). The next step is then to create time sliced reconstructions for stages in the Holocene, peeling of the subrecent and exposing past relief situation. This includes winding back the history of sea-level rise and delta progradation etc. etc. So far, this has mainly be done as 2D series of landscape maps, or as sea-level curve age-depth plots. In the last decade, academic and applied projects at Utrecht University, TNO Geological Survey of The Netherlands and Deltares have developed palaeoDEMs for the Dutch low lands, that are a third main way of showing coastal plain evolution. Importantly, we produce two types of palaeoDEMs: (1) geological surface mapping using deposit contacts from borehole descriptions (and scripted 3D processing techniques - e.g. Van der Meulen et al. 2013) and (2) palaeogroundwater surfaces, using sea-level and inland water-level index-points (and 3D kriging interpolations - e.g. Koster et al. 2016). The applications for the combined palaeoDEMs range from relative sea-level rise mapping and assessment of variation in rate of GIA across the coastal plain, to quantification of soft soil deformation, to analysis of pre-embankment extreme flood levels. Koster, K., Stafleu, J., & Cohen, K.M. (2016). Generic 3D interpolation of Holocene base-level rise and provision of accommodation space, developed for the Netherlands coastal plain and infilled palaeovalleys. Basin Research. DOI 10.1111/bre.12202 Van der Meulen, M.J., Doornenbal, J.C., Gunnink, J.L., Stafleu, J., Schokker, J., Vernes, R.W., Van Geer, F.C., Van Gessel, S.F., Van Heteren, S., Van Leeuwen, R.J.W. & Bakker, M.A.J. (2013). 3D geology in a 2D country: perspectives for geological surveying in the Netherlands. Netherlands Journal of Geosciences, 92, 217-241. DOI 10.1017/S0016774600000184

  1. Contribution of Anisotropy of Magnetic Susceptibility (AMS) to reconstruct flooding characteristics of a 4220 BP tsunami from a thick unconsolidated structureless deposit (Banda Aceh, Sumatra)

    Science.gov (United States)

    Wassmer, Patrick; Gomez, Christopher; Iskandasyah, T. Yan W. M.; Lavigne, Franck; Sartohadi, Junun

    2015-07-01

    One of the main concerns of deciphering tsunami sedimentary records along seashore is to link the emplaced layers with marine high energy events. Based on a combination of morphologic features, sedimentary figures, grain size characteristics, fossils content, microfossils assemblages, geochemical elements, heavy minerals presence; it is, in principle, possible to relate the sedimentary record to a tsunami event. However, experience shows that sometimes, in reason of a lack of any visible sedimentary features, it is hard to decide between a storm and a tsunami origin. To solve this issue, the authors have used the Anisotropy of Magnetic Susceptibility (AMS) to evidence the sediment fabric. The validity of the method for reconstructing flow direction has been proved when applied on sediments in the aftermath of a tsunami event, for which the behaviour was well documented (2004 IOT). We present herein an application of this method for a 56 cm thick paleo-deposit dated 4220 BP laying under the soil covered by the 2004 IOT, SE of Banda Aceh, North Sumatra. We analysed this homogenous deposit, lacking of any visible structure, using methods of classic sedimentology to confirm the occurrence of a high energy event. We then applied AMS technique that allowed the reconstruction of flow characteristics during sediment emplacement. We show that all the sequence was emplaced by uprush phases and that the local topography played a role on the re-orientation of a part of the uprush flow, creating strong reverse current. This particular behaviour was reported by eyewitnesses during the 2004 IOT event.

  2. A 2600-year history of floods in the Bernese Alps, Switzerland: frequencies, mechanisms and climate forcing

    Science.gov (United States)

    Schulte, L.; Peña, J. C.; Carvalho, F.; Schmidt, T.; Julià, R.; Llorca, J.; Veit, H.

    2015-07-01

    A 2600-year long composite palaeoflood record is reconstructed from high-resolution delta plain sediments of the Hasli-Aare floodplain on the northern slope of the Swiss Alps. Natural proxies compiled from sedimentary, geochemical and geomorphological data were calibrated by textual and factual sources and instrumental data. No fewer than 12 of the 14 historically recorded extreme events between 1480 and the termination of the Hasli-Aare river channel correction in 1875 were also identified by coarse-grained flood layers, log(Zr / Ti) peaks and factor 1 anomalies. Geomorphological, historical and instrumental data provide evidence for flood damage intensities and discharge estimations of severe and catastrophic historical floods. Spectral analysis of the geochemical and documentary flood series and several climate proxies (TSI, δ18O, tree-rings, NAO, SNAO) identify similar periodicities of around 60, 80, 100, 120 and 200 years during the last millennia, indicating the influence of the North Atlantic circulation and solar forcing on alpine flood dynamics. The composite floodplain record illustrates that periods of organic soil formation and deposition of phyllosilicates (from the medium high catchment area) match those of total solar irradiance maxima, suggesting reduced flood activity during warmer climate pulses. Aggradation with multiple sets of flood layers with increased contribution of siliciclasts from the highest catchment area (plutonic bedrock) (e.g. 1300-1350, 1420-1480, 1550-1620, 1650-1720 and 1811-1851 cal yr AD) occurred predominantly during periods with reduced solar irradiance, lower δ18O anomalies, cooler summer temperatures and phases of drier spring climate in the Alps. Increased water storage by glaciers, snow cover and snow patches susceptible to melting processes associated with rainfall episodes and abrupt rises in temperature substantially increased surface runoff on slopes and discharges of alpine rivers. This interpretation is in

  3. Modeling on Flash Flood Disaster Induced by Bed Load

    Institute of Scientific and Technical Information of China (English)

    CAO Shuyou; LIU Xingnian; HUANG Er; YANG Keiun

    2008-01-01

    Flash floods result from a complex interaction among hydro-meteorological, hydrologi-cal, and hydraulic processes across various spatial and temporal scales. Sichuan Province suffers flash floods frequently owing to mountain weather and topography. A flash flood and gravel bed load transport are two key relative problems in mountain river engineering. Bed materials are often encountered in alternate scouring and deposition in mountain fluvial processes during a flash flood.In this circumstance, CRS-1 bed load numerical model jointly with scale physical model is em-ployed to predict water level and gravel bed scour and deposition for design of flood control dykes and flash flood disaster mitigation. A case study on the mechanism of a flash flood disaster in-duced by bed load transport for a hydropower station in Sichuan Province is conducted. Finally,suggestions to protect the hydropower station are proposed.

  4. Contribution of Anisotropy of Magnetic Susceptibility (AMS to reconstruct flooding characteristics of a 4220 BP tsunami from a thick unconsolidated structureless deposit (Banda Aceh, Sumatra

    Directory of Open Access Journals (Sweden)

    Patrick Christian Wassmer

    2015-07-01

    Full Text Available One of the main concerns of deciphering tsunami sedimentary records along seashore is to link the emplaced layers with marine high energy events. Based on a combination of morphologic features, sedimentary figures, grain size characteristics, fossils content, microfossils assemblages, geochemical elements, heavy minerals presence; it is, in principle, possible to relate the sedimentary record to a tsunami event. However, experience shows that sometimes, in reason of a lack of any visible sedimentary features, it is hard to decide between a storm and a tsunami origin. To solve this issue, the authors have used the Anisotropy of Magnetic Susceptibility (AMS to evidence the sediment fabric. The validity of the method for reconstructing flow direction has been proved when applied on sediments in the aftermath of a tsunami event, for which the behaviour was well documented (2004 IOT. We present herein an application of this method for a 56 cm thick paleo-deposit dated 4220 BP laying under the soil covered by the 2004 IOT, SE of Banda Aceh, North Sumatra. We analysed this homogenous deposit, lacking of any visible structure, using methods of classic sedimentology to confirm the occurrence of a high energy event. We then applied AMS technique that allowed the reconstruction of flow characteristics during sediment emplacement. We show that all the sequence was emplaced by uprush phases and that the local topography played a role on the re-orientation of a part of the uprush flow, creating strong reverse current. This particular behaviour was reported by eyewitnesses during the 2004 IOT event.

  5. Does disturbance favour weak competitors? Mechanisms of changing plant abundance after flooding

    NARCIS (Netherlands)

    Lenssen, J.P.M.; Steeg, A. van der; Kroon, J.C.J.M. de

    2004-01-01

    Question: Does disturbance reduce competition intensity and thus favour weak competitors that are presumably less affected by disturbance than strong competitors? Methods: We used a single flooding event with increasing duration to simulate disturbance with increasing intensity. Six flood-plain gras

  6. On the Role of Flash Floods for Dust Emission over North Africa: Alluvial Sediments acting as Dust Source

    Science.gov (United States)

    Schepanski, K.; Klueser, L.; Tegen, I.

    2014-12-01

    Studies analyzing satellite dust products show that numerous dust sources are located in the foothills of arid and semi-arid mountain regions. There, alluvial sediments deposited on valley bottoms and flood plains are very susceptible to wind erosion and frequently serve as dust source. This study focuses on the spatio-temporal distribution of dust source activation events over the mountain foothills and flood plains over North Africa. Satellite dust retrievals with sub-daily resolution such as from Meteosat Second Generation (MSG) Spinning Enhanced Visible and InfraRed Imager (SEVIRI) and METOP A/B Infrared Atmospheric Sounding Interferometer (IASI) instruments are used to identify dust source regions. Identified dust source regions are then linked to soil properties and land type classification data sets. Information on the mineralogical composition of transported dust inferred from IASI observation are used (a) to investigate the impact of different source geomorphologies and thus different radiative properties of airborne dust particles, and (b) to estimate the contribution of dust uplift from alluvial sediments compared to dust emission from non-hydrological sources. Ultimately, this study contributes to the understanding of controlling mechanism on the interannual variability of dust source activation and will improve current dust emission modules coupled to atmosphere models.

  7. Paleobiological implications of dinosaur egg-bearing deposits in the Cretaceous Gyeongsang Supergroup of Korea

    Science.gov (United States)

    Paik, In Sung; Kim, Hyun Joo; Huh, Min

    2010-05-01

    Dinosaur egg-bearing deposits in the Cretaceous Gyeongsang Basin in Korea is described in taphonomic aspect, their paleoenvironments are interpreted, and geobiological implications of dinosaur egg-bearing deposits in the world and Korea are analyzed in geographic occurrences, geological ages, paleoenvironments, and lithology. Dinosaur eggs with spheroolithids, faveoloolithid, and elongatoolithid structural types occur in several stratigraphic formations of the Cretaceous Gyeongsang Basin in South Korea, and most of the egg-bearing formations are the Late Cretaceous. The dinosaur eggs usually occur as clutches in purple sandy mudstone of floodplain deposits preserved as calcic paleosol with association of vertic paleosol features in places. Most of the eggs are top-broken and filled with surrounding sediments. The general depositional environment of dinosaur egg deposits in the Gyeongsang Supergroup are interpreted as a dried floodplain where volcanic activity occurred intermittently in the vicinity of the nesting sites. Their depositional settings on which floodplains developed are diverse from fluvial plain with meandering rivers to alluvial plain with episodic sheet flooding. The nesting areas in the Gyeongsang Basin are deemed to have been under semi-arid climate, which resulted in formation of calcic soils facilitating preservation of the dinosaur eggs. The geochronologic occurrences of dinosaur egg-bearing deposits are mostly restricted to the Late Cretaceous in the world as well as in Korea. If it has not been resulted from biased discoveries and reports of dinosaur eggs, biological rather than physical and chemical conditions for preservation of dinosaur eggs might be related with the restricted occurrences in the Late Cretaceous. Two hypotheses are suggested for probable biological causes to the geochronologically restricted occurrences of dinosaur egg-bearing deposits. One is related with the appearance of angiosperms in the Late Jurassic and the spreading

  8. Dune development and migration to damage long established vegetation colonies in the lahar deposition zone of Ruapehu Volcano, New Zealand

    Science.gov (United States)

    Ohno, Y.; Kasai, M.; Marutani, T.

    2012-04-01

    This study reports migration of dunes that mainly originate from lahar deposits and gully erosion, in the Rangipo Desert on the skirts of the Ruapehu Volcano, New Zealand. Although the Rangipo Desert is not a dry desert (average annual rainfall: 1100mm), the occasional supply of volcanic materials from Ruapehu, strong wind (average maximum speed in a day: 12 m/s) together with low winter temperatures has created a desert-like landscape. The study site consists of a flood plain with sporadic tussock and alpine to sub-alpine vegetation colonies which often form mound-like structures and sand dunes on terraces on the flanks of the volcano. The accretionary mounds and dunes comprise layers of tephra and pumice of various ages, together with interstitial wind-blown materials. While shrubs thrive on these terrace tops, it was observed that migrating dunes of 3 m in height have progressively buried and killed vegetation at two sites. Aerial photographs taken in 2000 and 2011 indicated that the dunes originated from pockets of lahar deposits and gully out-wash materials on the flood plain and were migrating in the major leeward wind direction (Northeast), or towards the sites. The migration rate at one site was estimated at 5 m/year from the photography. The flood plain pockets had formed at points where the floor slope changed from steep to gentle. As they contain finer materials than their surroundings, they have produced a series of sequential dunes. The exposed floor between the dunes comprises pumice layers of low infiltration capacity, suggesting that dunes migrate and develop as they strip off floor deposits. Subsequent exposure of the layers induces surface flow concentration in wet weather to cause gully incision. In conclusion, lahar occurrence is a major controlling factor in development in the landscape of the Rangipo Desert, by not only directly flowing at times into the flood plain, but also by producing migrating dunes that impact on existing vegetation

  9. Flash flood characterisation of the Haor area of Bangladesh

    Science.gov (United States)

    Bhattacharya, B.; Suman, A.

    2012-04-01

    Haors are large bowl-shaped flood plain depressions located mostly in north-eastern part of Bangladesh covering about 25% of the entire region. During dry season haors are used for agriculture and during rainy season it is used as fisheries. Haors have profound ecological importance. About 8000 migratory wild birds visit the area annually. Some of the haors are declared at Ramsar sites. Haors are frequently affected by the flash floods due to hilly topography and steep slope of the rivers draining the area. These flash floods spill onto low-lying flood plain lands in the region, inundating crops, damaging infrastructure by erosion and often causing loss of lives and properties. Climate change is exacerbating the situation. For appropriate risk mitigation mechanism it is necessary to explore flood characteristics of that region. The area is not at all studied well. Under a current project a numerical 1D2D model based on MIKE Flood is developed to study the flooding characteristics and estimate the climate change impacts on the haor region. Under this study the progression of flood levels at some key haors in relation to the water level data at specified gauges in the region is analysed. As the region is at the border with India so comparing with the gauges at the border with India is carried out. The flooding in the Haor area is associated with the rainfall in the upstream catchment in India (Meghalaya, Barak and Tripura basins in India). The flood propagation in some of the identified haors in relation to meteorological forcing in the three basins in India is analysed as well. Subsequently, a ranking of haors is done based on individual risks. Based on the IPCC recommendation the precipitation scenario in the upstream catchments under climate change is considered. The study provides the fundamental inputs for preparing a flood risk management plan of the region.

  10. Mountain-Plains Curriculum.

    Science.gov (United States)

    Mountain-Plains Education and Economic Development Program, Inc., Glasgow AFB, MT.

    The document lists the Mountain-Plains curriculum by job title (where applicable), including support courses. The curriculum areas covered are mathematics skills, communication skills, office education, lodging services, food services, marketing and distribution, welding support, automotive, small engines, career guidance, World of Work, health…

  11. Global Aspects of Flood Risk Management

    Institute of Scientific and Technical Information of China (English)

    Wolfgang Kron

    2015-01-01

    Various flood disasters in the last decade have confirmed that the risk from flooding has been increasing significantly worldwide. The driving factors for the risk are the unabated increase in global population, the concentration of people in high-risk areas such as coasts and flood plains, the rise in vulnerability of assets, infrastructure and social systems, and the consequences of climate change. Risk reduction is based on comprehensive risk management from identification of the hazard and assessing the risk to building defenses. To achieve this, general awareness at all levels in a society is key. It is not sufficient merely to be aware of the situation-findings must be acted upon with no significant delay. Flood-related computations have progressed considerably in recent years, but model results can only be as good as their input data. Modeling floods and flood losses is very complex, as model parameters are subject to change during an event and conditions sometimes greatly depend on small-scale factors.

  12. Cascadia Tsunami Deposit Database

    Science.gov (United States)

    Peters, Robert; Jaffe, Bruce; Gelfenbaum, Guy; Peterson, Curt

    2003-01-01

    The Cascadia Tsunami Deposit Database contains data on the location and sedimentological properties of tsunami deposits found along the Cascadia margin. Data have been compiled from 52 studies, documenting 59 sites from northern California to Vancouver Island, British Columbia that contain known or potential tsunami deposits. Bibliographical references are provided for all sites included in the database. Cascadia tsunami deposits are usually seen as anomalous sand layers in coastal marsh or lake sediments. The studies cited in the database use numerous criteria based on sedimentary characteristics to distinguish tsunami deposits from sand layers deposited by other processes, such as river flooding and storm surges. Several studies cited in the database contain evidence for more than one tsunami at a site. Data categories include age, thickness, layering, grainsize, and other sedimentological characteristics of Cascadia tsunami deposits. The database documents the variability observed in tsunami deposits found along the Cascadia margin.

  13. Depositional setting and paleobotany of Permian and Triassic permineralized peat from the central Transantarctic Mountains, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, E.L.; Taylor, T.N.; Collinson, J.W. (Ohio State University, Columbus (USA). Byrd Polar Research Center)

    1989-06-01

    Silicified peat is known from two sites in the central Transantarctic Mountains. Both are within a 2-km-thick Permo-Triassic sandstone-shale sequence that was deposited by braided streams in a rapidly subsiding foreland basin along the paleo-Pacific margin of Antarctica. Upper Permian permineralized peat occurs as scattered boulders just above a channel-form sandstone in the upper part of the Buckley Formation on Skaar Ridge overlooking the Beardmore Glacier. These boulders are erosional remnants of fine-grained deposits that accumulated in shallow lakes or swamps on a flood plain. At Fremouw Peak, the peat occurs near the top of the Fremouw Formation in strata that are probably Middle to Late Triassic in age. The peat consists of large blocks that were rafted into a sandy braided stream channel during a flood and then stranded and buried as flood waters receded. Both sites are characterized by exceptionally well-preserved plant material, although the composition and diversity of the two floras are very different. Permineralization apparently took place rapidly and was enhanced by the dissolution of siliceous volcanic detritus that is abundant in both formations.

  14. Paleoenvironmental interpretation of an ancient Arctic coastal plain: Integrated paleopedology and palynology from the Late Cretaceous (Maastrichtian) Prince Creek Formation, North Slope, Alaska, USA

    Science.gov (United States)

    McCarthy, P. J.; Flaig, P. P.; Fiorillo, A. R.

    2010-12-01

    The Cretaceous (Early Maastrichtian), dinosaur-bearing Prince Creek Formation, North Slope, Alaska, records high-latitude, alluvial sedimentation and soil formation on a low-lying, coastal plain during a greenhouse phase in Earth history. This study combines outcrop observations, micromorphology, geochemistry, and palynological analyses of paleosols in order to reconstruct local paleoenvironments of weakly developed, high-latitude coastal plain soils. Sediments of the Prince Creek Fm. include quartz- and chert-rich sandstone channels, and floodplains containing organic-rich siltstone and mudstone, carbonaceous shale, coal and ashfall deposits. Vertically stacked horizons of blocky-to-platy, drab-colored mudstone and siltstone with carbonaceous root-traces and mottled aggregates alternating with sandy units indicate that the development of compound and cumulative, weakly-developed soils on floodplains alternated with overbank alluviation and deposition on crevasse splay complexes on floodplains . Soil formation occurred on levees, point bars, crevasse splays and along the margins of floodplain lakes, ponds, and swamps. Soil-forming processes were interrupted by repeated deposition of sediment on top of soil profiles by flooding of nearby channels. Alluviation is evidenced by thin (fern and moss spores, projectates, age-diagnostic Wodehouseia edmontonicola, hinterland bisaccate pollen and pollen from lowland trees, shrubs, and herbs indicate an Early Maastrichtian age for these sediments. Large and small theropods, hadrosaurs, pachycephalosaurs, and ceratopsians, as well as fishes and fossil mammals have been found as well. Paleosols are similar to modern aquic subgroups of Entisols and Inceptisols and, in more distal locations, potential acid sulfate soils. Integration of pedogenic processes and palynology suggests that these high latitude floodplains were influenced by seasonally(?) fluctuating water table levels on a coastal plain governed by a near polar light

  15. FLOOD PLAIN EVALUATION IN THE GANGA-BRAHMAPUTRA ...

    African Journals Online (AJOL)

    Dr Osondu

    2011-09-12

    Sep 12, 2011 ... but they face an uncertain future as development of river control structures, global ... India and in the Southern part of undivided Bengal. The delta is centrally located in ..... rates were determined by 137Cs and 210Pb radio.

  16. Los Alamos Canyon Ice Rink Parking Flood Plain Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hathcock, Charles Dean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Keller, David Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States

    2015-02-10

    The project location is in Los Alamos Canyon east of the ice rink facility at the intersection of West and Omega roads (Figure 1). Forty eight parking spaces will be constructed on the north and south side of Omega Road, and a lighted walking path will be constructed to the ice rink. Some trees will be removed during this action. A guardrail of approximately 400 feet will be constructed along the north side of West Road to prevent unsafe parking in that area.

  17. Comprehensive Flood Plain Studies Using Spatial Data Management Techniques.

    Science.gov (United States)

    1978-06-01

    and subbasin hydraulic length. The technique adopted is a modest extension and automation of the method developed for San Diego County (Franziniet al...land classified as 14 I ____.4_ natural vegetation under existing conditions is 272 acres while the total amount of landA classified as natural

  18. Characteristics and origin of Earth-mounds on the Eastern Snake River Plain, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Tullis, J.A.

    1995-09-01

    Earth-mounds are common features on the Eastern Snake River Plain, Idaho. The mounds are typically round or oval in plan view, <0.5 m in height, and from 8 to 14 m in diameter. They are found on flat and sloped surfaces, and appear less frequently in lowland areas. The mounds have formed on deposits of multiple sedimentary environments. Those studied included alluvial gravel terraces along the Big Lost River (late Pleistocene/early Holocene age), alluvial fan segments on the flanks of the Lost River Range (Bull Lake and Pinedale age equivalents), and loess/slopewash sediments overlying basalt flows. Backhoe trenches were dug to allow characterization of stratigraphy and soil development. Each mound has features unique to the depositional and pedogenic history of the site; however, there are common elements to all mounds that are linked to the history of mound formation. Each mound has a {open_quotes}floor{close_quotes} of a sediment or basement rock of significantly different hydraulic conductivity than the overlying sediment. These paleosurfaces are overlain by finer-grained sediments, typically loess or flood-overbank deposits. Mounds formed in environments where a sufficient thickness of fine-grained sediment held pore water in a system open to the migration to a freezing front. Heaving of the sediment occurred by the growth of ice lenses. Mound formation occurred at the end of the Late Pleistocene or early in the Holocene, and was followed by pedogenesis. Soils in the mounds were subsequently altered by bioturbation, buried by eolian deposition, and eroded by slopewash runoff. These secondary processes played a significant role in maintaining or increasing the mound/intermound relief.

  19. Flood geomorphology of Arthurs Rock Gulch, Colorado: paleoflood history

    Science.gov (United States)

    Waythomas, Christopher F.; Jarrett, Robert D.

    1994-11-01

    Episodic late Quaternary flooding is recorded by bouldery deposits and slackwater sediments along Arthurs Rock Gulch, an ephemeral stream west of Fort Collins, Colorado. Flood deposits consist of individual granodiorite and pegmatite boulders, boulder bars, and coarse overbank sediment that rest on erosional terrace segments along the channel. We identified evidence for at least five flood in the lower two thirds of the 1.84 km 2 drainage basin. Flood deposits are differentiated by their position above the active channel, weathering characteristics, degree of boulder burial by colluvium, amount of lichen cover, and position with respect to terrace and colluvial deposits. Age estimates for the flood deposits are based on radiocarbon dating, tree-ring analyses, and relative-age criteria from four sites in the basin. At least two floods occurred in the last 300 years; a third flood is at least 5000 years old, but likely younger than 10,000 yr BP; and the two oldest floods occurred at least 40,000 years BP.

  20. The depositional setting of the Late Quaternary sedimentary fill in southern Bannu basin, Northwest Himalayan fold and thrust belt, Pakistan

    KAUST Repository

    Farid, Asam M.

    2014-07-10

    Geostatistical variogram and inversion techniques combined with modern visualization tools have made it possible to re-model one-dimensional electrical resistivity data into two-dimensional (2D) models of the near subsurface. The resultant models are capable of extending the original interpretation of the data to depict alluvium layers as individual lithological units within the 2D space. By tuning the variogram parameters used in this approach, it is then possible to visualize individual lithofacies and geomorphological features for these lithologic units. The study re-examines an electrical resistivity dataset collected as part of a groundwater study in an area of the Bannu basin in Pakistan. Additional lithological logs from boreholes throughout the area have been combined with the existing resistivity data for calibration. Tectonic activity during the Himalayan orogeny uplifted and generated significant faulting in the rocks resulting in the formation of a depression which subsequently has been filled with clay-silt and dirty sand facies typical of lacustrine and flood plain environments. Streams arising from adjacent mountains have reworked these facies which have been eroded and replaced by gravel-sand facies along channels. It is concluded that the sediments have been deposited as prograding fan shaped bodies, flood plain, and lacustrine deposits. Clay-silt facies mark the locations of paleo depressions or lake environments, which have changed position over time due to local tectonic activity and sedimentation. The Lakki plain alluvial system has thus formed as a result of local tectonic activity with fluvial erosion and deposition characterized by coarse sediments with high electrical resistivities near the mountain ranges and fine sediments with medium to low electrical resistivities towards the basin center. © 2014 Springer International Publishing Switzerland.

  1. Sedimentation patterns across a Coastal Plain floodplain: The importance of hydrogeomorphic influences and cross-floodplain connectivity

    Science.gov (United States)

    Kaase, Christopher T.; Kupfer, John A.

    2016-09-01

    The floodplains of large Coastal Plain rivers in the southeastern U.S. are important long-term storage sites for alluvial sediment and nutrients. Yet considerable uncertainty surrounds sediment dynamics on many large river floodplains and, in particular, the local scale factors that affect the flux of sediment and nutrients from rivers onto their floodplains and their subsequent deposition. This research quantifies short-term rates of sediment deposition from 2012 to 2014 on floodplain sites at Congaree National Park using feldspar pads. Sediment deposition rates ranged from 0.1 to 15.6 cm (median = 1.46 cm) and were closely associated with inundation frequency and geomorphic position. Cross-floodplain distributary channels served as particularly important conduits for moving sediment onto the floodplain. Physical and chemical analyses of soil samples demonstrated that the most flood-exposed sites had higher major nutrient and micronutrient levels (especially of phosphorus) and more diverse nutrient compositions. This research advances current understandings of lateral floodplain connectivity by demonstrating the complex effects of regional hydrology and local floodplain environmental characteristics on the supply of sediment and nutrients.

  2. 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,…

  3. Mid-Holocene palaeoflood events recorded at the Zhongqiao Neolithic cultural site in the Jianghan Plain, middle Yangtze River Valley, China

    Science.gov (United States)

    Wu, Li; Zhu, Cheng; Ma, Chunmei; Li, Feng; Meng, Huaping; Liu, Hui; Li, Linying; Wang, Xiaocui; Sun, Wei; Song, Yougui

    2017-10-01

    Palaeo-hydrological and archaeological investigations were carried out in the Jianghan Plain in the middle reaches of the Yangtze River. Based on a comparative analysis of modern flood sediments and multidisciplinary approaches such as AMS14C and archaeological dating, zircon micromorphology, grain size, magnetic susceptibility, and geochemistry, we identified palaeoflood sediments preserved at the Zhongqiao archaeological site. The results indicate that three palaeoflood events (i.e. 4800-4597, 4479-4367, and 4168-3850 cal. yr BP) occurred at the Zhongqiao Site. Comparisons of palaeoflood deposit layers at a number of Neolithic cultural sites show that two extraordinary palaeoflood events occurred in the Jianghan Plain during approximately 4900-4600 cal. yr BP (i.e.mid-late Qujialing cultural period) and 4100-3800 cal. yr BP (i.e. from late Shijiahe cultural period to the Xia Dynasty). Further analysis of the environmental context suggests that these flooding events might have been connected with great climate variability during approximately 5000-4500 cal. yr BP and at ca. 4000 cal. yr BP. These two palaeoflood events were closely related to the expansion of the Jianghan lakes driven by the climatic change, which in turn influenced the rise and fall of the Neolithic cultures in the middle reaches of the Yangtze River. Other evidence also suggests that the intensified discrepancy between social development and environmental change processes (especially the hydrological process) during the late Shijiahe cultural period might be the key factor causing the collapse of the Shijiahe Culture. The extraordinary floods related to the climatic anomaly at ca. 4000 cal. yr BP and political conflicts from internal or other cultural areas all accelerated the collapse of the Shijiahe Culture.

  4. How Can Flood Affect the Real Estate Market?

    Science.gov (United States)

    Trejo Rangel, Miguel Angel; Sapač, Klaudija; Brilly, Mitja

    2016-04-01

    The purpose of this paper is to examine how actual flood events can affect the real estate for different case studies. Therefore, we have analysed the impact for two cases, the first is the flood event which occurred in 2013 in Boulder, Colorado, United States, city that is located in the eastern part of the Rocky Mountains, and the second event was the flood which occurred in 2010 the city of Ljubljana, capital and largest city of Slovenia, that is located between the Alpine and Balkan mountains.. The methodology that was used is comparison of mean prices of real estate, taking into account the flood events which have been chosen in accordance with the available data and previous studies, furthermore for the case study of Ljubljana, Slovenia questionnaires were sent through one civil organization which is actively working in the area (Civil Initiative for Flood Security SW part of Ljubljana). Analysed sales prices during the period 2009-2014 in the case study of Boulder, Colorado, United States showed that the flood event in 2013 did not significantly affect the mean price of real estate within the flooded area, besides prices inside the flood plain tended to stay above the prices outside the floodplain. Nevertheless, we have found that the flood event affected the real estate sector in terms of number of sales, being that after the flood event in 2013 sales decreased 52% regarding the previous years. For the case study of Ljubljana, Slovenia the results were unexpected somehow. In fact we expected that the prices of real estate located within the flooded areas, on average, would be lower than those located outside the flooded areas, and that was what shown in the results, which is actually opposite to what occurred for the case study of Boulder City. However the research showed that the flood event in 2010 did not affect the change in prices of real estate within the flooded areas and the trend was considerable similar to previous years the flood event in 2010

  5. Reconstruction of an interrupted primary beach plain succession using a Geographical Information System

    NARCIS (Netherlands)

    Veen, A. van der; Grootjans, A.P.; de Jong, J.; Rozema, J.

    1997-01-01

    This study reports on a primary succession on a beach plain on the Dutch Wadden island of Schiermonnikoog. Vegetation succession started in 1959 when a sand dike was constructed to prevent structural erosion of the area by storm floods. Since then the sandy beach behind the dike has been protected f

  6. Modelling the effects of surface water flood pulses on groundwater

    NARCIS (Netherlands)

    Schot, P.P.; Wassen, M.J.

    2010-01-01

    Flood pulses in wetlands steer ecosystem development directly through surface water processes and indirectly through the effects of the flood pulse on groundwater. Direct effects on ecosystems are exerted by e.g. inundation and deposition of sediments containing nutrients. Indirect effects include t

  7. Exogenic forces action mechanism in the development process of erosion landform on alluvial plains composed of fluvial-lacustrine deposits in the Taklimakan Desert%塔克拉玛干沙漠河湖相沉积平原风蚀地貌发育的外营力作用机制

    Institute of Scientific and Technical Information of China (English)

    李生宇; 谷峰; 王海峰; 庞营军; 穆桂金; 雷加强; 刘小路; 张忠良; 闫健

    2012-01-01

    河湖相沉积是一种非固结沉积物,是风蚀地貌发育的一种重要地质基础.在塔克拉玛干沙漠中发育在这种沉积物上的风蚀地貌分布非常普遍,但相关研究较少,尚缺乏风蚀地貌发育过程方面的研究.基于野外调查信息和理论分析,结合相关文献,分析了塔克拉玛干沙漠河湖相平原风蚀地貌发育的外营力作用机制.研究结果表明:(1)风蚀地貌发育的外营力作用主要有:风化作用、流水作用、风蚀作用以及重力作用;(2)风蚀作用是风蚀地貌发育的主要外营力,但是风化作用、流水作用和重力作用也发挥着重要的作用,它们的关键作用是形成风蚀突破口,而重力作用和风化作用是促进风蚀地貌后期快速发展的重要作用;(3)各种外营力协同作用和互为条件,它们在风蚀地貌发育的各阶段的重要性不同;(4)沉积层特殊沉积构造和外营力作用共同造成了风蚀地貌形态特征.%Fluvial - lacustrine deposit is a kind of consolidation sediments that is one important geological basis for erosion landform. The erosion landform developed on alluvial plains composed of fluvial - lacustrine deposits is widely distributed. But its relevant studies, especially about the development process of erosion landform are very less. Based on the field survey information, theoretical analysis and some relevant articles, this paper comprehensively analyzed the exogenic forces action mechanism in the development process of erosion landform on alluvial plains composed of fluvial - lacustrine deposits in the Taklimakan Desert. The results show as the following; ( 1) These main exogenic forces including weathering, tunning water, aeolian erosion and gravity drive the erosion land-form development on alluvial plains composed of fluvial - lacustrine deposits in the Taklimakan Desert. (2) Because aeolian activities in the Taklimkan Desert occur very frequent, so aeolian erosion plays a leading

  8. Database of recent tsunami deposits

    Science.gov (United States)

    Peters, Robert; Jaffe, Bruce E.

    2010-01-01

    This report describes a database of sedimentary characteristics of tsunami deposits derived from published accounts of tsunami deposit investigations conducted shortly after the occurrence of a tsunami. The database contains 228 entries, each entry containing data from up to 71 categories. It includes data from 51 publications covering 15 tsunamis distributed between 16 countries. The database encompasses a wide range of depositional settings including tropical islands, beaches, coastal plains, river banks, agricultural fields, and urban environments. It includes data from both local tsunamis and teletsunamis. The data are valuable for interpreting prehistorical, historical, and modern tsunami deposits, and for the development of criteria to identify tsunami deposits in the geologic record.

  9. A review of flood disaster management in India using remote sensing

    Science.gov (United States)

    Singh, K.; Trivedi, R.

    On going account of the geographical position, climate and geological setting, India from time immemo rial, has been hit by natural disaster, occasionally with fury. There is hardly a year when some part of the country or other does not face the specter of either drought or flood due to either the failure or the abundance of monsoons in vulnerable areas respectively. OF the total annual rainfall, 75% is received during 4 months of monsoon (June to September) and, as a result, almost all the rivers carry heavy discharge during this period. The flood hazard is compounded by sediment deposition, drainage congestion and synchronization of river floods with sea tides in the coastal plains. While the area liable to floods is more than 40 million hectares. The average area affected by floods annually is about 8 million hectares. Due to the erratic behavior of the monsoons, low and medium rainfall regions constituting 68% of the country's total area are rendered vulnerable to periodical droughts. India has a long coastline of 8041kms.On an average, 5 to 6 tropical cyclones from in the Bay of Bengal and Arabian Sea every year; 2 to 3 of them are being very severe. The Himalayan Mountain considered being the world's youngest fold belt in the east and the Chaman fault in the west, constitute one of the most seismically active region in the world. Earthquake, land sliders and avalanches are not uncommon. On an average, these natural disasters take to a heavy toll of human and animal lives, affect few million hectares of crop area and have damaged millions of houses annually during the last decade alone. In the context of the perpetual risk emanating from the recurring natural calamities, the country needs to develop an effective preparedness to manage the impact of natural disaster. The emergence of India as an advance country in the arena of remote sensing with its own satellite in orbit supplemented by the Indian Metrological department in relatively accurate prediction of

  10. Identification of extreme sedimentary event deposits in Yilan coastal area, Taiwan, and the western coast of Myanmar

    Science.gov (United States)

    Tsai, Y. L.; Shyu, J. B. H.; Sawai, Y.; Kunz, A.

    2016-12-01

    The Yilan Plain in northeastern Taiwan is located west of the Ryukyu Trench. In AD 1771, a M7.4 earthquake occurred near the Ryukyu Trench, and generated a tsunami (the Meiwa Tsunami) with run-up height of more than 30 m on the Ishigaki Island, only 250 km away from the Yilan Plain. Therefore, we suggest that tsunami poses potential threats to the Yilan Plain. Offshore western Myanmar, a M8.5 earthquake occurred in 1762 on the nearby Sunda Trench. The 2004 Sumatra Tsunami also reached approximately 3 m high along the western coast of Myanmar according to local residents. These observations also point out the potential for a future tsunami hazard along the rapidly developing western Myanmar coast. Therefore, we attempted to search for geological record of previous extreme sedimentary events in these two areas in this study. Many previous studies have pointed out that paleo-tsunami deposits are most likely present in inter-ridge lowlands, and have distinctive characteristics such as a coarse sand layer covering soil layers (or other terrestrial facies sediment layers) with a very sharp boundary. Thus we excavated several trenches in our two study areas to observe and record the deposits, collect samples, and use C-14 dating, Cs-137 analyses and diatom analyses to help us understand the age and sedimentary environment of the deposits. In one trench in northern Yilan Plain, we found a 25 cm thick sand layer covering a mud layer with a sharp and horizontal boundary. We infer that this sand layer deposited during a fluvial flooding event. In southern Yilan Plain, we found another sand layer covering a black mud layer with a sharp and irregular boundary. This clearly indicates a high-energy depositional event, but the source of such an event remains unknown. In trenches excavated along the western coast of Myanmar, we found a gray sand layer covering an organic mud layer that has abundant plant debris with a sharp boundary. Thus we infer that the gray sand is also an

  11. Flood of October 8, 1962, on Bachman Branch and Joes Creek at Dallas, Texas

    Science.gov (United States)

    Ruggles, Frederick H.

    1966-01-01

    This report presents hydrologic data that enable the user to define areas susceptible to flooding and to evaluate the flood hazard along Bachman Branch and Joes Creek. The data provide a technical basis for making sound decisions concerning the use of flood-plain lands. The report will be useful for preparing building and zoning regulations, locating waste disposal facilities, purchasing unoccupied land, developing recreational areas, and managing surface water in relation to ground-water resources. This is one of the series of reports delineating the flood hazard on streams in the Dallas area.

  12. Floods in the Skagit River basin, Washington

    Science.gov (United States)

    Stewart, James E.; Bodhaine, George Lawrence

    1961-01-01

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

  13. Integrating a Typhoon Event Database with an Optimal Flood Operation Model on the Real-Time Flood Control of the Tseng-Wen Reservoir

    Science.gov (United States)

    Chen, Y. W.; Chang, L. C.

    2012-04-01

    Typhoons which normally bring a great amount of precipitation are the primary natural hazard in Taiwan during flooding season. Because the plentiful rainfall quantities brought by typhoons are normally stored for the usage of the next draught period, the determination of release strategies for flood operation of reservoirs which is required to simultaneously consider not only the impact of reservoir safety and the flooding damage in plain area but also for the water resource stored in the reservoir after typhoon becomes important. This study proposes a two-steps study process. First, this study develop an optimal flood operation model (OFOM) for the planning of flood control and also applies the OFOM on Tseng-wun reservoir and the downstream plain related to the reservoir. Second, integrating a typhoon event database with the OFOM mentioned above makes the proposed planning model have ability to deal with a real-time flood control problem and names as real-time flood operation model (RTFOM). Three conditions are considered in the proposed models, OFOM and RTFOM, include the safety of the reservoir itself, the reservoir storage after typhoons and the impact of flooding in the plain area. Besides, the flood operation guideline announced by government is also considered in the proposed models. The these conditions and the guideline can be formed as an optimization problem which is solved by the genetic algorithm (GA) in this study. Furthermore, a distributed runoff model, kinematic-wave geomorphic instantaneous unit hydrograph (KW-GIUH), and a river flow simulation model, HEC-RAS, are used to simulate the river water level of Tseng-wun basin in the plain area and the simulated level is shown as an index of the impact of flooding. Because the simulated levels are required to re-calculate iteratively in the optimization model, applying a recursive artificial neural network (recursive ANN) instead of the HEC-RAS model can significantly reduce the computational burden of

  14. Probable flood predictions in ungauged coastal basins of El Salvador

    Science.gov (United States)

    Friedel, M.J.; Smith, M.E.; Chica, A.M.E.; Litke, D.

    2008-01-01

    A regionalization procedure is presented and used to predict probable flooding in four ungauged coastal river basins of El Salvador: Paz, Jiboa, Grande de San Miguel, and Goascoran. The flood-prediction problem is sequentially solved for two regions: upstream mountains and downstream alluvial plains. In the upstream mountains, a set of rainfall-runoff parameter values and recurrent peak-flow discharge hydrographs are simultaneously estimated for 20 tributary-basin models. Application of dissimilarity equations among tributary basins (soft prior information) permitted development of a parsimonious parameter structure subject to information content in the recurrent peak-flow discharge values derived using regression equations based on measurements recorded outside the ungauged study basins. The estimated joint set of parameter values formed the basis from which probable minimum and maximum peak-flow discharge limits were then estimated revealing that prediction uncertainty increases with basin size. In the downstream alluvial plain, model application of the estimated minimum and maximum peak-flow hydrographs facilitated simulation of probable 100-year flood-flow depths in confined canyons and across unconfined coastal alluvial plains. The regionalization procedure provides a tool for hydrologic risk assessment and flood protection planning that is not restricted to the case presented herein. ?? 2008 ASCE.

  15. Evaluation of Holocene pollen records from the Romanian Plain.

    Science.gov (United States)

    Tomescu

    2000-05-01

    This study is a critical review of pollen analyses carried out on Holocene sequences from 15 sites in and near the Romanian Plain. Three sites come from natural sediments, 10 sites are from anthropogenic deposits and two are from both anthropogenic and natural settings. The general reconstruction is of a steppe-forest-steppe vegetation through the Holocene. The nature of the deposits, however, casts doubts on this reconstruction. Deposits of archaeological sites generally yield pollen spectra that are influenced by human activities and thus unsuitable for vegetation reconstructions. Loess deposits are also unfavorable for pollen preservation because of high pH and porosity. Consequently, pollen spectra from loess deposits are strongly biased by selective pollen destruction. Research and experiments carried out by several authors suggest that spectra dominated by Asteraceae, Poaceae, Chenopodiaceae or Pinus pollen in soils and loess are a result of selective pollen destruction, especially if low pollen concentrations, progressive pollen deterioration or high frequencies of deteriorated or unidentifiable pollen are evidenced. The fact that pollen records from the Romanian Plain come from loess, alkaline peat or archaeological sites reduces their reliability for reconstructions of vegetation. The vegetation history of similar regions in Hungary, Bulgaria and Turkey suggests that early Holocene steppe vegetation was gradually replaced by forest or forest-steppe vegetation in the late Holocene. Records from lake sediments are required to find out whether the Holocene vegetation history of the Romanian Plain was similar.

  16. Specific yield, High Plains aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents specific-yield ranges in the High Plains aquifer of the United States. The High Plains aquifer underlies 112.6 million acres (176,000...

  17. Vegetation line transects of Goose Pasture and Pool No. 1: Clarence Cannon National Wildlife Refuge: Part of Wildlife Management Study – Project 2: Evaluating production of moist soil plants in the Mississippi River Flood Plain and their subsequent use by waterfowl

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Wildlife Management Study - Project No. 2 dated May 15, 1969 was developed to evaluate the production of moist soil food plants in the Mississippi River flood...

  18. South China Flooded

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Vehicles traverse a flooded street in Liuzhou, guangxi zhuang Autonomous Region, on May 19.heavy rainstorms repeatedly struck China this month, triggering floods, mudflows and landslides. hunan, guangdong and Jiangxi provinces and Chongqing Municipality were the worst hit.

  19. 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...

  20. 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...

  1. Flooding: Prioritizing protection?

    Science.gov (United States)

    Peduzzi, Pascal

    2017-09-01

    With climate change, urban development and economic growth, more assets and infrastructures will be exposed to flooding. Now research shows that investments in flood protection are globally beneficial, but have varied levels of benefit locally.

  2. 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...

  3. 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...

  4. Record of glacial Lake Missoula floods in glacial Lake Columbia, Washington

    Science.gov (United States)

    Hanson, Michelle A.; Clague, John J.

    2016-02-01

    During the last glaciation (marine oxygen isotope stage 2), outburst floods from glacial Lake Missoula deposited diagnostic sediments within glacial Lake Columbia. Two dominant outburst flood lithofacies are present within glacial Lake Columbia deposits: a flood expansion bar facies and a finer-grained hyperpycnite facies. We conclude that the flood sediments have a glacial Lake Missoula source because: (1) current indicators indicate westward flow through the lake, and upvalley flow followed by downvalley flow in tributary valleys; (2) no flood sediments are found north of a certain point; (3) there is a dominance of Belt-Purcell Supergroup clasts in a flood expansion bar; and (4) some of the finer-grained beds have a pink colour, reflective of glacial Lake Missoula lake-bottom sediments. A new radiocarbon age of 13,400 ± 100 14C BP on plant detritus found below 37 flood beds helps constrain the timing of outburst flooding from glacial Lake Missoula.

  5. Flood Risk Regional Flood Defences: Technical report

    NARCIS (Netherlands)

    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

  6. Flood Risk Regional Flood Defences: Technical report

    NARCIS (Netherlands)

    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 ext

  7. A STUDY ON THE FLOOD STORAGE CAPACITY IN DONGTING LAKE

    Institute of Scientific and Technical Information of China (English)

    Yitian LI; Jinyun DENG; Zhaohua SUN

    2003-01-01

    Using field data from the 1950's to 1990's, the flood storage capacity of Dongting Lake was analyzed.The impacts of sediment deposition in Dongting Lake and in the reach of the Yangtze River from Chenglingji to Hankou were analyzed. The effects of land reclamation in the lake region on the flood storage capacity also were analyzed on annual and other time scales. The study shows that sediment deposition in the downstream reach is the main reason of flood storage increases under the same inflow condition.

  8. Channeling episodes of Kasei Valles, Mars, and the nature of ridged plains material

    Science.gov (United States)

    Chapman, Mary G.; Tanaka, Kenneth L.

    1991-01-01

    The geologic mapping compiled at 1:500,000 scale of the northern Kasei Valles area of Mars (MTMs 25062 and 25067) indicates (1) at least three periods of Kasei Valles channeling, (2) the development of Sacra Fossae (linear depressions on Tempe Terra and Lunae Planum) in relation to Kasei channeling episodes, and (3) the nature of ridged plains material dissected by Kasei Valles on northern Lunae Planum. (The three channeling periods consists of two flood events and a later, sapping related event). These findings suggest hydrologic conditions and processes that formed Kasei Valles and associated features and terrains. It is concluded that an early period of flooding, whose source is perhaps buried beneath lava flows of Tharsis Montes, may have eroded streamlined features in northern Lunae Planum. Also, later floods originating from Echus Chasma formed after the initial flooding and the mesas adjacent to the plateau. The Sacra Fossae formed after the initial flooding and during the second flooding by sapping, outbreak, scarp retreat, and collapse along joints and fractures in ridged plains materials.

  9. THE FLOOD RISK IN THE LOWER GIANH RIVER: MODELLING AND FIELD VERIFICATION

    Directory of Open Access Journals (Sweden)

    NGUYEN H. D.

    2016-03-01

    Full Text Available Problems associated with flood risk definitely represent a highly topical issue in Vietnam. The case of the lower Gianh River in the central area of Vietnam, with a watershed area of 353 km2, is particularly interesting. In this area, periodically subject to flood risk, the scientific question is strongly linked to risk management. In addition, flood risk is the consequence of the hydrological hazard of an event and the damages related to this event. For this reason, our approach is based on hydrodynamic modelling using Mike Flood to simulate the runoff during a flood event. Unfortunately the data in the studied area are quite limited. Our computation of the flood risk is based on a three-step modelling process, using rainfall data coming from 8 stations, cross sections, the topographic map and the land-use map. The first step consists of creating a 1-D model using Mike 11, in order to simulate the runoff in the minor river bed. In the second step, we use Mike 21 to create a 2-D model to simulate the runoff in the flood plain. The last step allows us to couple the two models in order to precisely describe the variables for the hazard analysis in the flood plain (the water level, the speed, the extent of the flooding. Moreover the model is calibrated and verified using observational data of the water level at hydrologic stations and field control data (on the one hand flood height measurements, on the other hand interviews with the community and with the local councillors. We then generate GIS maps in order to improve flood hazard management, which allows us to create flood hazard maps by coupling the flood plain map and the runoff speed map. Our results show that: the flood peak, caused by typhoon Nari, reached more than 6 m on October 16th 2013 at 4 p.m. (its area was extended by 149 km². End that the typhoon constitutes an extreme flood hazard for 11.39%, very high for 10.60%, high for 30.79%, medium for 31.91% and a light flood hazard for 15

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

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

    2014-05-01

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

  12. Quaternary deposits and landscape evolution of the central Blue Ridge of Virginia

    Science.gov (United States)

    Scott, Eaton L.; Morgan, B.A.; Craig, Kochel R.; Howard, A.D.

    2003-01-01

    A catastrophic storm that struck the central Virginia Blue Ridge Mountains in June 1995 delivered over 775 mm (30.5 in) of rain in 16 h. The deluge triggered more than 1000 slope failures; and stream channels and debris fans were deeply incised, exposing the stratigraphy of earlier mass movement and fluvial deposits. The synthesis of data obtained from detailed pollen studies and 39 radiometrically dated surficial deposits in the Rapidan basin gives new insights into Quaternary climatic change and landscape evolution of the central Blue Ridge Mountains. The oldest depositional landforms in the study area are fluvial terraces. Their deposits have weathering characteristics similar to both early Pleistocene and late Tertiary terrace surfaces located near the Fall Zone of Virginia. Terraces of similar ages are also present in nearby basins and suggest regional incision of streams in the area since early Pleistocene-late Tertiary time. The oldest debris-flow deposits in the study area are much older than Wisconsinan glaciation as indicated by 2.5YR colors, thick argillic horizons, and fully disintegrated granitic cobbles. Radiocarbon dating indicates that debris flow activity since 25,000 YBP has recurred, on average, at least every 2500 years. The presence of stratified slope deposits, emplaced from 27,410 through 15,800 YBP, indicates hillslope stripping and reduced vegetation cover on upland slopes during the Wisconsinan glacial maximum. Regolith generated from mechanical weathering during the Pleistocene collected in low-order stream channels and was episodically delivered to the valley floor by debris flows. Debris fans prograded onto flood plains during the late Pleistocene but have been incised by Holocene stream entrenchment. The fan incision allows Holocene debris flows to largely bypass many of the higher elevation debris fan surfaces and deposit onto the topographically lower surfaces. These episodic, high-magnitude storm events are responsible for

  13. Biostratigraphic and Geochronological Evidences of Floods in the Holocene: the South-East of the Taimyr Peninsula, Russia

    Science.gov (United States)

    Ukraintseva, V.; Pospelov, I.

    2009-04-01

    Having conducted the research in the basins of the rivers Kotuy and Medvezhiya (71°09' North, 102°43' East) we identified for the first time the phenomenon of palaeofloods in the south-eastern part of the Taimyr Peninsula. The studied district can be equally referred to both the utmost East of the Putoran Plateau, and the utmost West of the Anabar Plateau: their geological structures meet in this very place. The vegetation of the investigated district belongs to the northern taiga type. The lower forest belt (to 200 m below the sea level) is formed by Gmelin larch Larix gmelinii (Rupr.) Rupr. Beginning with the sub-boreal period of the Holocene, namely since 3900 ± 60 years BP, high waters and floods occurred in this region constantly. The evidences thereof are as follows: (1) absence of plants` pollen and spore in the whole 10-meter formation of sediments in the 2nd terrace above the flood-plain of the Medvezhiya River; (2) absence of plants` pollen and spore in the surface samples taken in a larch forest with upland soil near the investigated geological cross-section; (3) lithology and biostratigraphy of the investigated geological cross-section; (4) contemporary hydrological situation in the Kotuy-Medvezhiya river system. The eight radiocarbon dates, obtained from the 10-meter sequence of the investigated deposits, are evident of the fact that the second terrace above the flood-plain of the Medvezhiya River was formed in the Holocene during the last four thousand years (table). Beginning in the second half of the sub-boreal period of the Holocene, namely 3900 ± 60 years ago, high waters and floods occurred in this region constantly. Judging by the contemporary hydrological situation of the rivers, the level of the water rise during the high waters and floods reached about 4 meters, and possibly more, in the ancient Kotuy River and about 1.5 meters in the ancient Medvezhiya River. High waters and floods in Taimyr rivers is an ordinary phenomenon. One can

  14. Several factors which influence the dynamics of drill hole flooding and the accumulated oil samples using the installation at the B/sub 8/ Soviet deposit as an example

    Energy Technology Data Exchange (ETDEWEB)

    Bagautdinov, A.K.; Kharitonova, T.P.; Solopakha, V.M.

    1979-01-01

    Individual groupings which are characterized by a variety of dynamics of drill hole flooding were isolated as a result of studying the dynamics of drill hole flooding. The latter is associated with the location (the positioning) of productive drill holes, the inter-grouping of external and internal observational drill holes, and the influence of a variety of geological and industrial factors. Recommendations on the drilling of installations established that strata analogous to the B/sub 8/ type are determined based on the analytical results of these factors.

  15. Flood Impact Modelling and Natural Flood Management

    Science.gov (United States)

    Owen, Gareth; Quinn, Paul; ODonnell, Greg

    2016-04-01

    Local implementation of Natural Flood Management methods are now being proposed in many flood schemes. In principal it offers a cost effective solution to a number of catchment based problem as NFM tackles both flood risk and WFD issues. However within larger catchments there is the issue of which subcatchments to target first and how much NFM to implement. If each catchment has its own configuration of subcatchment and rivers how can the issues of flood synchronisation and strategic investment be addressed? In this study we will show two key aspects to resolving these issues. Firstly, a multi-scale network water level recorder is placed throughout the system to capture the flow concentration and travel time operating in the catchment being studied. The second is a Flood Impact Model (FIM), which is a subcatchment based model that can generate runoff in any location using any hydrological model. The key aspect to the model is that it has a function to represent the impact of NFM in any subcatchment and the ability to route that flood wave to the outfall. This function allows a realistic representation of the synchronisation issues for that catchment. By running the model in interactive mode the user can define an appropriate scheme that minimises or removes the risk of synchornisation and gives confidence that the NFM investment is having a good level of impact downstream in large flood events.

  16. 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...

  17. Propagation and composition of the flood wave on the upper Mississippi River, 1993

    Science.gov (United States)

    Moody, John A.

    1995-01-01

    The flood wave on the upper Mississippi River started downstream near St. Paul, Minnesota, in June 1993. The maximum discharge propagated downstream at about 50 kilometers per day and was 5 to 7 times the mean daily discharge at streamgaging sites on the river. The propagation speed of the flood wave was influenced more by hydrologic factors such as tributary inflow and flood-plain storage than by hydraulic factors. The maximum discharge at St. Louis, Missouri (29,700 m3/s) occurred on August 1, 1993; but because of flood-plain storage resulting from levee failures and seepage through and under levees downstream, the maximum discharge at Thebes, Illinois, (27,700 m>3/s) did not occur until August 7 which was about 4 days later than normal.

  18. Geomorphological Impacts of an extreme Flood in Karoon River, Iran

    Science.gov (United States)

    Yousefi, Saleh; Mirzaee, Somaya; Keesstra, Saskia; Piegay, Herve; Pourghasemi, Hamid Reza

    2017-04-01

    An extreme flood occurred on 14.04.2016 in Kroon River. Using the OLI Landsat images on 08.04.2016 (before flood) and 24.04.2016 (after flood) the morphological evolution in different land cover types by this flood event were detected. The results show that the event significantly affected the channel width. The main effect was the high mobilization of channel sediments and severe bank erosion in the studied meandering reach. According to field surveys, the flood occupied the whole channel corridor and even some of the flood plain parts, but the channel pattern was not markedly changed. Results show the average of active channel width increased from 192 m to 256 m respectively for before and after flood. Statistical results indicate a significant change for active channel width and sinuosity index at 99% confidence level for both indexes. Findings show that the channel morphological changes (channel widening) varied significantly in different land cover types along the Karoon River banks. Specifically, the channel has widened less in the residential areas than the other land cover types, which is the result of bank protection activities. Keywords: Remote sensing, fluvial geomorphology, floodplain management, river evolution.

  19. Creating Flood Inundation Maps For Lower Sakarya River

    Directory of Open Access Journals (Sweden)

    Osman Sönmez

    2013-06-01

    Full Text Available The Sakarya River Basin in Turkey frequently floods. The allure of riverside settlement and of nutrient-rich riverbank soil has led to extensive residential and agricultural development in flood plains. In this study, the 100 years return period possible flood carrying capacites of last 113 km of the Lower Sakarya Riverbed were investigated, also dam break and risk analyses were performed by applying different scenarios for the floods likely to occur. Flooding scenarios and water depth within the floodplain during these scenarios were calculated with the HEC-RAS software program and results were converted into a map in HEC-GeoRAS,ArcGIS 9x and ArcView 3.2 programs. As a result, it was observed that the Lower Sakarya River is susceptible to flooding. Recent observations of the study area confirm the study findings. This study tries to underscore the importance of taking into account the different scenarios regarding flood prevention and reduction studies.

  20. Late Quaternary geology of the Lower Central Plain, Thailand

    Science.gov (United States)

    Sinsakul, Sin

    2000-08-01

    The Lower Central Plain or Chao Phraya Plain, located in the upper Gulf of Thailand, has an average elevation of 2 m above the present mean sea level. It is a fault bounded basin developed in the Plio-Pleistocene epoch. Consequently, the basin has been filled with Quaternary sediment reaching a thickness of almost 2000 m, of which only the upper 300 m is known. The Pleistocene deposits of the Lower Central Plain represent a complex interplay of alluvial, fluvial and deltaic environments of the Chao Phraya River and its tributaries. The upper sequence of sand and stiff clay with iron-oxide concretions on the surface was deposited in a fluviatile environment subjected to a regressive period in the late Pleistocene. The term "Chao Phraya delta" is used to define the landform where the Chao Phraya River interacted with marine processes as the sea level changed during the Holocene transgression. These strata indicated that the Holocene sea reached its maximum height of 4 m above the present mean sea level around 6000 years B.P.; from then on sea level fluctuated until it reached its present level around 1500 years B.P. This complex sea level history has caused the progradation of tidal flat, and tide-dominated delta deposits, consisting of soft marine clay, that covered the Lower Central Plain to an average depth of 15 m in the Bangkok area. The soft marine clay or Bangkok clay is the most important unit in the stratigraphic sequence in terms of land subsidence in the Lower Central Plain. Evidence of coastal erosion is also considerable in the low tidal flat area on the west bank of the Chao Phraya River mouth and adjacent coast.

  1. Integration of LiDAR and cropmark remote sensing for the study of fluvial and anthropogenic landforms in the Brenta-Bacchiglione alluvial plain (NE Italy)

    Science.gov (United States)

    Ninfo, Andrea; Mozzi, Paolo; Abbà, Tiziano

    2016-05-01

    The geomorphological study of alluvial plains takes great advantage from the integration of detailed altimetry with high-resolution images, especially in the lower-relief sectors, like those in the distal plain of the Brenta and Bacchiglione rivers near the city of Padua (mean slope 1-0.8‰). The LiDAR data which were specifically acquired for this research (Riegl LMS-Q560, mean density 7 points/m2, overall area 123 km2), were classified and interpolated in order to map fluvial and anthropogenic landforms. The acquisition was carried out in a moment of minimal vegetation luxuriance (March 2011), in order to minimize ground cover. The DEM (z accuracy aggradation, associated with ridges and widespread crevasse channels and splays during the middle Holocene. The derived maps provide significant support to land and urban planning, e.g., in the definition of appropriate geotechnical analysis, the estimation of buried archeological deposits in the city center, and the assessment of flooding hazard.

  2. Identification of thick sedimentary plains north of Hellas

    Science.gov (United States)

    Salese, Francesco; Mangold, Nicolas; Ansan, Veronique; Carter, John; Ody, Anouck; Poulet, François; Ori, Gian Gabriele

    2016-04-01

    Understanding the origin and timing of intercrater plains is crucial to understand the Martian history in relation with endogenic and/or exogenic cycles. Intercrater plains north of Hellas basin on Mars are thought to have hosted different sedimentary environments during the Late Noachian/Early Hesperian, and they offer a well-preserved insight into the regional geological history of Mars. Our new geologic mapping of the intercrater plains north of Hellas Basin is based on the rich data set from MRO and Mars Express and provides new insights into the region's geological history. These findings appear to constrain the interpretation of the nature and age of intercrater plains in this region, although we acknowledge that for example the source of the sedimentary deposits must be subject to further analysis. The northern part of Hellas basin displays topographically flat area, which was characterized during the Late Noachian by sedimentary deposition and later, in the Late Hesperian, by fissural volcanism. The map and crater retention ages enable us to interpret the geologic history of the region. The stratigraphically lower unit is represented by crustal outcrops. Across most of the region, the sedimentary unit covers the basement and is eroded into mesas, erosional windows and perched by fresh craters. Intercrater plains' sedimentary deposits north of Hellas display horizontal light-toned layered rich in Fe/Mg-phyllosilicates and local crossbedding stratification. The Noachian sedimentary deposits of the intercrater plains north of Hellas are locally covered by Hesperian lava flows, showing that intercrater plains are sedimentary and volcanic in origin. We found different erosional (regional and local) surfaces, at HiRISE scale inside sediments due to local erosional windows and at CTX scale we found two important regional erosional surfaces. The oldest between crustal outcrops and sediments, which is likely Middle Noachian in age and the youngest between sediments

  3. Southeastern Coastal Plain aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Southeastern Coastal Plain aquifer system in Kentucky, Tennessee, Mississippi, Alabama, Georgia, and South Carolina.

  4. DEMOGRAPHIC VULNERABILITIES IN TECUCI PLAIN

    Directory of Open Access Journals (Sweden)

    Iulian Adrian ŞORCARU

    2013-06-01

    Full Text Available The study focuses on analyzing and mapping 8 indicators considered to best reflect the demographic vulnerability in Tecuci Plain in the year 2010 and proposes a model of aggregation which finally allows us to distinguish three major types of demographic vulnerability (low, medium and high. Mapping the final values also shows significant disparities in the territorial administrative units that broadly overlap the plain, the most vulnerable being Tecuci city and the peripheral communes, towards Vrancea and Vaslui Counties.

  5. Concentrations of selected metals in Quaternary-age fluvial deposits along the lower Cheyenne and middle Belle Fourche Rivers, western South Dakota, 2009-10

    Science.gov (United States)

    Stamm, John F.; Hoogestraat, Galen K.

    2012-01-01

    The headwaters of the Cheyenne and Belle Fourche Rivers drain the Black Hills of South Dakota and Wyoming, an area that has been affected by mining and ore-milling operations since the discovery of gold in 1875. A tributary to the Belle Fourche River is Whitewood Creek, which drains the area of the Homestake Mine, a gold mine that operated from 1876 to 2001. Tailings discharged into Whitewood Creek contained arsenopyrite, an arsenic-rich variety of pyrite associated with gold ore, and mercury used as an amalgam during the gold-extraction process. Approximately 18 percent of the tailings that were discharged remain in fluvial deposits on the flood plain along Whitewood Creek, and approximately 25 percent remain in fluvial deposits on the flood plain along the Belle Fourche River, downstream from Whitewood Creek. In 1983, a 29-kilometer (18-mile) reach of Whitewood Creek and the adjacent flood plain was included in the U.S. Environmental Protection Agency's National Priority List of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, commonly referred to as a "Superfund site." Listing of this reach of Whitewood Creek was primarily in response to arsenic toxicity of fluvial deposits on the flood plain. Lands along the lower Cheyenne River were transferred to adjoining States and Tribes in response to the Water Resources Development Act (WRDA) of 1999. An amendment in 2000 to WRDA required a study of sediment contamination of the Cheyenne River. In response to the WRDA amendment, the U.S. Geological Survey completed field sampling of reference sites (not affected by mine-tailing disposal) along the lower Belle Fourche and lower Cheyenne Rivers. Reference sites were located on stream terraces that were elevated well above historical stream stages to ensure no contamination from historical mining activity. Sampling of potentially contaminated sites was performed on transects of the active flood plain and adjacent terraces that could

  6. {sup 210}Pb geochronology and chemical characterization of sediment cores from lakes of the Parana river alluvial plain

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, L.F.L.; Damatto, S.R.; Scapin, M.A. [IPEN - Instituto de Pesquisas Energeticas e Nucleares (Brazil); Remor, M.B.; Sampaio, S.C. [UNIOESTE - Universidade Estadual do Oeste do Parana (Brazil)

    2014-07-01

    The flood plain of the upper Parana River is located among the lakes formed by the Brazilian hydroelectric plants being the last part of the Parana river, in Brazil, where there is an ecosystem with interaction river-flood plain. This flood plain has considerable habitat variability, with great diversity of terrestrial and aquatic species, and the floods are the main factor that regulates the operation of this ecosystem. The seasonality of the flood pulses is mainly influenced by the El Nino phenomenon, which increases precipitation in the drainage basin of the flood plain of the upper Parana River. Because of its unique characteristics this ecosystem is the subject of intense study since 1980, mainly from the ecological point of view. Therefore, two sediment cores were collected in the ponds formed by the floods, Patos pond and Garcas pond, in order to characterize the sediment chemically and evaluate a possible historic contamination. The trace element concentrations As, Ba, Br, Ce, Co, Cr, Cs, Eu, Hf, La, Lu, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn (mg.kg{sup -1}) and the major elements Si, Al, Fe, Ti, K, Ca, Mg, P, V, Mn, and Na (%) were determined in the sediment cores dated by {sup 210}Pb method, using instrumental neutron activation analysis, X-ray fluorescence and gross beta counting, respectively. The results obtained for the elements Ce, Cr, Cs, La, Nd, Sc, Sm and Th are higher than the values of Upper Continental Crust for both ponds. The sedimentation rates obtained for Garca pond, 0.77 cm.y{sup -1}, and Patos pond, 0.62 cm.y{sup -1} are in agreement with studies performed in sedimentary environments similar to the present work, such as Brazilian wetland Pantanal. The enrichment factor and the geo-accumulation index were used to assess the presence of anthropogenic sources of pollution. Document available in abstract form only. (authors)

  7. Late Quaternary incision and deposition in an active volcanic setting: The Volturno valley fill, southern Italy

    Science.gov (United States)

    Amorosi, Alessandro; Pacifico, Annamaria; Rossi, Veronica; Ruberti, Daniela

    2012-12-01

    Extensive illustration of depositional facies, ostracod and foraminiferal assemblages, and Late Quaternary stratigraphic architecture is offered for the first time from beneath the modern coastal plain of Volturno River, the longest river in southern Italy. Proximity to an active volcanic district, including quiescent Vesuvius Volcano, provides an easily identifiable stratigraphic marker (Campania Grey Tuff or CGT), up to 55 m thick, emplaced 39 ky cal BP by a large-volume explosive pyroclastic eruption. Identification of top CGT to a maximum depth of 30 m allows tracing out the shape of a 15-20 km wide Late Quaternary palaeovalley incised by Volturno River into the thick ignimbritic unit immediately after its deposition. A terraced palaeotopography of the valley flanks is reconstructed on the basis of core data. Above the basal fluvial deposits, the early Holocene transgressive facies consist of a suite of estuarine (freshwater to brackish) deposits. These are separated from overlying transgressive barrier sands by a distinctive wave ravinement surface. Upwards, a distinctive shallowing-upward succession of middle-late Holocene age is interpreted to reflect initiation and subsequent progradation of a wave-dominated delta system, with flanking strandplains, in response to reduced rate of sea-level rise. The turnaround from transgressive to highstand conditions is identified on the basis of subtle changes in the meiofauna. These enable tracking of the maximum flooding surface into its updip (lagoonal/estuarine) counterpart, thus highlighting the role of refined palaeontological criteria as a powerful tool for high-resolution sequence-stratigraphic studies.

  8. RASOR flood modelling

    Science.gov (United States)

    Beckers, Joost; Buckman, Lora; Bachmann, Daniel; Visser, Martijn; Tollenaar, Daniel; Vatvani, Deepak; Kramer, Nienke; Goorden, Neeltje

    2015-04-01

    Decision making in disaster management requires fast access to reliable and relevant information. We believe that online information and services will become increasingly important in disaster management. Within the EU FP7 project RASOR (Rapid Risk Assessment and Spatialisation of Risk) an online platform is being developed for rapid multi-hazard risk analyses to support disaster management anywhere in the world. The platform will provide access to a plethora of GIS data that are relevant to risk assessment. It will also enable the user to run numerical flood models to simulate historical and newly defined flooding scenarios. The results of these models are maps of flood extent, flood depths and flow velocities. The RASOR platform will enable to overlay historical event flood maps with observations and Earth Observation (EO) imagery to fill in gaps and assess the accuracy of the flood models. New flooding scenarios can be defined by the user and simulated to investigate the potential impact of future floods. A series of flood models have been developed within RASOR for selected case study areas around the globe that are subject to very different flood hazards: • The city of Bandung in Indonesia, which is prone to fluvial flooding induced by heavy rainfall. The flood hazard is exacerbated by land subsidence. • The port of Cilacap on the south coast of Java, subject to tsunami hazard from submarine earthquakes in the Sunda trench. • The area south of city of Rotterdam in the Netherlands, prone to coastal and/or riverine flooding. • The island of Santorini in Greece, which is subject to tsunamis induced by landslides. Flood models have been developed for each of these case studies using mostly EO data, augmented by local data where necessary. Particular use was made of the new TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) product from the German Aerospace centre (DLR) and EADS Astrium. The presentation will describe the flood models and the

  9. Reconstructing the Holocene depositional environments along the northern coast of Sfax (Tunisia): Mineralogical and sedimentological approaches

    Science.gov (United States)

    Lamourou, Ali; Touir, Jamel; Fagel, Nathalie

    2017-05-01

    parameters were consistent with a transition from a fluviatile depositional environment with some emersion phases marked by the gypsum precipitation, to a marine littoral environment. Such evolution was accompanied with a relative sea-level rise which flooded the fluvial system at the coastal plain during the Holocene, in agreement with sea-level fluctuations in southeast Tunisia during the Holocene.

  10. Facies transition and depositional architecture of the Late Eocene tide-dominated delta in northern coast of Birket Qarun, Fayum, Egypt

    Science.gov (United States)

    Abdel-Fattah, Zaki A.

    2016-07-01

    Late Eocene successions in the Fayum Depression display notable facies transition from open-marine to brackish-marine realms. Stratigraphic and sedimentologic characteristics of the depositional facies are integrated with ichnological data for the recognition of four facies associations (FA1 to FA4). The transition from open-marine sandstones (FA1) to the brackish-marine deposits (FA2) heralds a transgressive - regressive dislocation. The shallowing- and coarsening-upward progradation from the basal prodelta mudstone-dominated facies (FA2a) to deltafront heterolithics (FA2b) and sandstone facies (FA2c) are overlain by finning-upward delta plain deposits which are expressed by the delta plain mudstone (FA2d) and erosive-based distributary channel fills (FA4). Prodelta/deltfront deposits of FA2 are arranged in thinning- and coarsening-upward parasequences which are stacked in a shallowing-upward progressive cycle. Shallow-marine fossiliferous sandstones (FA3) mark the basal part of each parasequence. Stratigraphic and depositional architectures reflect a tide-dominated delta rather than an estuarine and incised valley (IV) model. This can be evinced by the progressive facies architecture, absence of basal regional incision or a subaerial unconformity and the stratigraphic position above a maximum flooding surface (MFS), in addition to the presence of multiple tidally-influenced distributary channels. Stratigraphic and depositional characteristics of the suggested model resemble those of modern tide-dominated deltaic systems. Accordingly, this model contributes to our understanding of the depositional models for analogous brackish-marine environments, particularly tide-dominated deltas in the rock record.

  11. Predicting geomorphically-induced flood risk for the Nepalese Terai communities

    Science.gov (United States)

    Dingle, Elizabeth; Creed, Maggie; Attal, Mikael; Sinclair, Hugh; Mudd, Simon; Borthwick, Alistair; Dugar, Sumit; Brown, Sarah

    2017-04-01

    Rivers sourced from the Himalaya irrigate the Indo-Gangetic Plain via major river networks that support 10% of the global population. However, many of these rivers are also the source of devastating floods. During the 2014 Karnali River floods in west Nepal, the Karnali rose to around 16 m at Chisapani (where it enters the Indo-Gangetic Plain), 1 m higher than the previous record in 1983; the return interval for this event was estimated to be 1000 years. Flood risk may currently be underestimated in this region, primarily because changes to the channel bed are not included when identifying areas at risk of flooding from events of varying recurrence intervals. Our observations in the field, corroborated by satellite imagery, show that river beds are highly mobile and constantly evolve through each monsoon. Increased bed levels due to sediment aggradation decreases the capacity of the river, increasing significantly the risk of devastating flood events; we refer to these as 'geomorphically-induced floods'. Major, short-lived episodes of sediment accumulation in channels are caused by stochastic variability in sediment flux generated by storms, earthquakes and glacial outburst floods from upstream parts of the catchment. Here, we generate a field-calibrated, geomorphic flood risk model for varying upstream scenarios, and predict changing flood risk for the Karnali River. A numerical model is used to carry out a sensitivity analysis of changes in channel geometry (particularly aggradation or degradation) based on realistic flood scenarios. In these scenarios, water and sediment discharge are varied within a range of plausible values, up to extreme sediment and water fluxes caused by widespread landsliding and/or intense monsoon precipitation based on existing records. The results of this sensitivity analysis will be used to inform flood hazard maps of the Karnali River floodplain and assess the vulnerability of the populations in the region.

  12. NASA Global Flood Mapping System

    Science.gov (United States)

    Policelli, Fritz; Slayback, Dan; Brakenridge, Bob; Nigro, Joe; Hubbard, Alfred

    2017-01-01

    Product utility key factors: Near real time, automated production; Flood spatial extent Cloudiness Pixel resolution: 250m; Flood temporal extent; Flash floods short duration on ground?; Landcover--Water under vegetation cover vs open water

  13. Progress in and prospects for fluvial flood modelling.

    Science.gov (United States)

    Wheater, H S

    2002-07-15

    Recent floods in the UK have raised public and political awareness of flood risk. There is an increasing recognition that flood management and land-use planning are linked, and that decision-support modelling tools are required to address issues of climate and land-use change for integrated catchment management. In this paper, the scientific context for fluvial flood modelling is discussed, current modelling capability is considered and research challenges are identified. Priorities include (i) appropriate representation of spatial precipitation, including scenarios of climate change; (ii) development of a national capability for continuous hydrological simulation of ungauged catchments; (iii) improved scientific understanding of impacts of agricultural land-use and land-management change, and the development of new modelling approaches to represent those impacts; (iv) improved representation of urban flooding, at both local and catchment scale; (v) appropriate parametrizations for hydraulic simulation of in-channel and flood-plain flows, assimilating available ground observations and remotely sensed data; and (vi) a flexible decision-support modelling framework, incorporating developments in computing, data availability, data assimilation and uncertainty analysis.

  14. An assessment of flood mitigation measures - "room for the river

    Science.gov (United States)

    Komma, J.; Blöschl, G.; Habereder, C.

    2009-04-01

    In this paper we analyse the relative effect of different flood mitigation measures for the example of the Kamp catchment in Austria. The main idea is to decrease flood peaks through (a) retaining water in the landscape and (b) providing additional inundation areas along the main stream (room for the river). To increase the retention of excess rainfall in the landscape we introduced two different measures. One measure is the increase of water storage capacity in the study catchment through the change of land use from agriculture to forest. The second measure is the installation of many small sized retention basins without an outlet (micro ponds). The micro ponds are situated at the hill slopes to intercept surface runoff. In case of the room for the river scenario the additional retention volume is gained due to the installation of retention basins along the Kamp river and its tributary Zwettl. Three flood retention basins with culverts at each river are envisaged. The geometry of the bottom outlets is defined for design discharges in a way to gain the greatest flood peak reduction for large flood events (above a 100 yr flood). The study catchment at the Kamp river with a size of 622 km² is located in north-eastern Austria. For the simulation of the different scenarios (retaining water in the landscape) a well calibrated continuous hydrologic model is available. The hydrological model consists of a spatially distributed soil moisture accounting scheme and a flood routing component. To analyse the effect of the room for the river scenario with retention basins along the river reaches a linked 1D/2D hydrodynamic model (TUFLOW) is used. In the river channels a one dimensional simulation is carried out. The flow conditions in the flood plains are represented by two dimensional model elements. The model domain incorporates 18 km of the Kamp and 12 km of the Zwettl river valley. For the assessment of the land use change scenario the hydrologic model parameters for

  15. Tropical stormwater floods: a sustainable solution

    Science.gov (United States)

    Molinie, Jack; Bade, Francois; Nagau, Jimmy; Nuiro, Paul

    2017-04-01

    Stormwater management is one of the most difficult problem of urban and suburban area. The urban runoff volume related to rain intensity and surfaces properties can lead to flood. Thereby, urban flooding creates considerable infrastructure problem, economics and human damages. In tropical countries, burgeoning human population coupled with unplanned urbanization altered the natural drainage. Consequently, classical intense rain around 100 cm/h produces frequent street flooding. In our case, we study the management of intense tropical rain, by using a network of individual rain storage tanks. The study area is economical and industrial zone installed in a coastal plain , with seventy per cent of impermeable surface (roads, parking lots, building roof, …) and thirty per cent of wetland (mangrove, …). Our solution is to delay the routes and parking lots runoff to the roof one. We propose sustainable individual water storage and a real time dynamical management, which permit to control the roof water arrival in the stormwater culvert. During the remaining time, the stored rainwater can be used for domestic activities instead of the use of drinking water.

  16. Floods of April 1952 in the Missouri River basin

    Science.gov (United States)

    Wells, J.V.B.

    1955-01-01

    The floods of April 1952 in the Milk River basin, along the Missouri River from the mouth of the Little Missouri River to the mouth of the Kansas River, and for scattered tributaries of the Missouri River in North and South Dakota were the greatest ever observed. The damage amounted to an estimated $179 million. The outstanding featur6 of the floods was the extraordinary peak discharge generated in the Missouri River at and downstream from Bismarck, N. Dak., on April 6 when a large ice jam upstream from the city was suddenly released. Inflow from flooding tributaries maintained the peak discharge at approximately the same magnitude in the transit of the flood across South Dakota; downstream from Yankton, S. Dak., attenuation of the peak discharge was continuous because of natural storage in the wide flood plains. The outstanding characteristic of floods in the Milk River basin was their duration--the flood crested at Havre, Mont., on April 3 and at Nashua, Mont.. on April 18. The floods were caused by an abnormally heavy accumulation of snow that was converted into runoff in a few days of very warm weather at the end of March. The heaviest water content of the snow pack at breakup was in a narrow arc extending through Aberdeen, S. Dak., Pierre, S. Dak.. and northwestward toward the southwest corner of North Dakota. The water content in part of this concentrated cover exceeded 6 inches. The winter of 1951-52, which followed a wet cold fall that made the ground impervious, was one of the most severe ever experienced in South Dakota and northern Montana. Depths of snow and low temperatures combined to produce, at the end of March, one of the heaviest snow covers in the history of the Great Plains. The Missouri River ice was intact upstream from Chamberlain, S. Dak., at the end of March, and the breakup of the ice with inflow of local runoff was one of the spectacular features of the flood. Runoff from the Yellowstone River combining with the flood pouring from the

  17. Fluvial depositional environment evolving into deltaic setting with marine influences in the buntsandstein of northern vosges (France)

    Science.gov (United States)

    Gall, Jean-Claude

    supersaturation of stagnant waters with time. The fluvial environment persists up to the lower part of the Grès à Voltzia where the progression of the sea towards the west gives rise to a close intertonguing of fluvial and marine influences in a deltaic setting. Lenticular sandstone bodies are laid down as stream mouth bars at the end of the distributary channels and as river bars in the watercourses during both normal and flood discharge. Silty-clayey sediments settle out in stagnant water in restricted ponds, pools and puddles as well as in extensive veneers of shallow water in the overbank plain between the streams. Carbonate-bearing deposits originate in the coastal littoral mud flat, marsh seam, beach belt and tidal flat. The Grès à Voltzia has the greatest palaeoenvironmental and palaeoecological significance in the Buntsandstein of the Northern Vosges due to the occurrence of a wealth of extraordinarily well-preserved plant and animal fossils (having been recovered by Louis Grauvogel during almost 50 years and since abt. 25 years by Jean-Claude Gall). The rich suite of faunal and floral elements includes aquatic invertebrates, terrestrial animals and continental plants. The aquatic invertebrate fauna lives in fresh lakes and brackish ponds in the overbank plain and in brackish lagoons in the coastal seam as well as in hypersaline and euhaline marginal marine waters. The terrestrial plants colonize both dry and wet substrates, and the continental fauna consists of mainly arthropods, amphibians and reptiles inhabiting the levee zones of standing and flowing waters and strolling across the desiccated flats. The marine euryhaline association of invertebrates is with time replaced by a stenohaline community, and the deltaic plain of the Grès à Voltzia is finally inundated by a pellicular transgression representing the first stage of the Muschelkalk sea setting an end to Buntsandstein continental deposition.

  18. Response of flood discharging capacity to the deterioration of the lower Yellow River

    Institute of Scientific and Technical Information of China (English)

    LI; Wenxue; LI; Yong; YAO; Wenyi; SU; Yunqi; ZHANG; Xiaohua

    2004-01-01

    Based on the clarifications of the deterioration characteristics of the lower Yellow River (LYR), the influence of river deterioration on flood discharging capacity is studied through theoretical derivation and analysis of field data. This study indicates that response of flood discharging capacity to river deterioration is nonlinear. Sediment depositions in the main channel cause the reductions of dominant discharge and thus the increase of initial flood stage. Reductions in the channel width result in the increases of the rising rate of flood stage and the decrease of flood discharging capacity.

  19. The applicability of the sediment deposition geochronology with {sup 2'}1{sup '}0{sup P}B as a tool in the sediment accumulation from the Taquari River, Pantanal, MS, Central region, Brazil; Aplicabilidade da geocronologia da deposicao de sedimento com {sup 2{sup }}1{sup {sup }}0{sup P}B como ferramenta na avaliacao do assoreamento do Rio Taquari, Pantanal, MS

    Energy Technology Data Exchange (ETDEWEB)

    Godoy, J.M. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil); Padovani, C.R.; Vieira, L.M. [EMBRAPA, Corumba, MS (Brazil). Centro de Pesquisa Agropecuaria do Pantanal; Pereira, J.C.A. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Quimica

    1998-07-01

    This work presents {sup 210} Pb geochronology of five bottom sediment cores from flood plain lakes of middle Taquari River, Pantanal, MS. In two cores of a same lake, an increase of the sediment deposition rate were observed, reflecting an increasing of the sediment input to the Pantanal. The main causes suggested for this increasing are climatic change, and the development of agriculture and cattle-raising in the watershed highlands, for the last 25 years. The results pointed too for the importance of a additional sample in the superior region of the middle Taquari River. (author)

  20. On Flood Alert

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    lina braces fora particularly dangerous flood season in the wake of disastrous rainstorms Aseries of heavy storms since early May led to severe flooding and landslides in south and southwest China,causing heavy casualties and economic losses. Severe convective weather such as downpours,

  1. 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…

  2. The Neogene molasse deposits of the Zagros Mountains in central Dezful Embayment: facies, sedimentary environments and controls

    Directory of Open Access Journals (Sweden)

    Ali Hossein Jalilian

    2016-03-01

    Full Text Available The upper part of Neogene sequence of the Zagros Mountains consists of a clastic succession which is identified as Aghajari and Bakhtyari formations. The sequence is an excellent example of synorogenic sedimentation or molasse deposited in northern portion of the Zagros foreland basin. Sedimentological analysis of an outcrop section representing Miocene-Pliocene sediments in central Dezful Embayment resulted in recognizing 9 lithofacies and 4 architectural elements. These lithofacies include conglometate (Gt, Gh, Gmm, sandstone (Sp, Sh, Sr, St and mudstone (Fm, Fl that were deposited in meandering stream, braided river and alluvial fan environments. Paleocurrent analysis of cross-beds, channels and asymmetric ripple marks indicate that these Neogene clastics were mainly drived from Cretaceous to Paleogene highlands in the Zagros Mountains on the north. This stratigraphic record is coarsening-upward and formed by a regressive depositional megacycle under arid climate. Facies and depositional history analysis show that sedimentation of the Zagros molasse was primarily controlled by base-level changes rather than catchment lithology or climate. The sedimentary record of this regressive megacycle reveales the base-level was constantly falling down on one hand and the provenance was uplifting on the other hand. Tectonic activities and Zagros Mountains rising in the Late Miocene resulted in deposition of fining-upward point-bar and floodplain sequences of the Aghajari Formation in low-gradient meandering streams. The Lahbari Member of the Aghajari Formation represents deposition in braided rivers that composed predominantly of flood-plain deposits in the Early Pliocene. Finally, the sedimentary cycle of the Zagros molasse deposits terminated with massive conglomerates of the Bakhtyari Formation deposited in large alluvial fans near the source area.

  3. Establishment of Brazos River Flood Event Layer Proxies for Paleoclimate Reconstruction and Flood Layer Preservation on the Texas Continental Shelf

    Science.gov (United States)

    McGuffin, A. B.; Carlin, J. A.; Dellapenna, T.

    2016-12-01

    The Brazos River, which empties into the Gulf of Mexico along the central Texas coast, is strongly modulated by the El Niño-Southern Oscillation (ENSO), with drought conditions during La Niña periods, and flood conditions during El Niño periods. During the most recent strong ENSO in 2015-2016, Texas experienced record rainfall, resulting in record discharge and flooding of the Brazos River. Since 1967 most of the large floods on the Brazos River have corresponded to ENSO events, thus the purpose of this study is to track the 2015-1016 Brazos River flood deposits on the continental shelf to develop a proxy for strong ENSO events in the northwestern Gulf of Mexico. Between June 2015 and July 2016, six offshore sampling trips have been conducted at the mouth of the river, along the dispersal pathway, and at what is believed to be the ultimate sink, the Texas Mud Blanket (TMB), a mid-shelf mud deposit roughly 75 km downdrift of the river mouth. A total of 33 short gravity cores, 36 box cores, and two vibracores were collected from the area, and were imaged using X-ray radiography, and analyzed for grain size, porosity and 7Be activity. The short gravity cores and box cores were collected proximal to the mouth of the Brazos River and were used to delineate the flood deposit and create a time series of flood event sediment dispersal. Flood event deposits have been identified as clay-rich, homogeneous packages with 50-80% water content. Deposits range between 2-10 cm thick and have been found up to 12 km off the coast. 7Be activity of dry bulk sediment was measured in one vibracore from the TMB and detected up to 8 cm deep. The Brazos River is the only fluvial source in the region and elevated 7Be inventories therefore suggest Brazos River flood event sediment is deposited in the TMB. Comparisons between proximal Brazos River sediment core radiographs and TMB vibracore radiographs preliminarily suggest preservation of flood event layers in the TMB. Additional short

  4. Development and lithogenesis of the palustrine and calcrete deposits of the Dibdibba Alluvial Fan, Kuwait

    Science.gov (United States)

    AlShuaibi, Arafat A.; Khalaf, Fikry I.

    2011-08-01

    A model is proposed for the development of the Quaternary palustrine carbonate-calcrete association, which occurs as hard crust capping low hills at a distal flood plain of Al Dibdibba alluvial fan located at southwestern Kuwait. Field occurrence, detailed petrographic investigation and geochemical analysis revealed that a single cycle of groundwater calcrete with vertical gradational maturity pattern was developed. This represents a continuous sedimentological cycle during which flood sheet conditions prevailed with intermittent periods of humid and arid conditions. Subsequently, calcitic micrite was continuously precipitated from small, shallow, local, isolated and short lived ponds fringed by freshwater marshes with abundant charophyte meadows. The latter were developed as a result of flooding scattered depressions by groundwater supersaturated with respect to calcite due to rise of groundwater table. The deposition of two facies of carbonate muds, namely; biomicrite and pelintraclasts skeletal micrites was followed by a drought phase which witnessed desiccation of the fresh water ponds and significant drop in groundwater level. A sequence of pedogenic and diagenetic processes acted on the deposited carbonate muds are manifested by: (a) desiccation cracks, (b) micrite neomorphism, (c) infilling of root burrows and some cracks by aeolian siliciclastics, (d) karstification, (e) marmorization, (f) calcretization of root burrow infill and development of pseudo-rhizocrete, (g) calcite cementation and mineral authigenesis, and (h) silcretization. These processes are responsible for the development of hard palustrine carbonate crust. At the advent of aridity, the whole system of Al Dibdibba alluvial fan was subjected to deflation. This resulted in reversing the paleotopography of the hard crusted palustrine depressions into carbonate capped domal hills.

  5. Millenial scale changes in flood magnitude and frequency and the role of changes in channel adjustment.

    Science.gov (United States)

    Croke, Jacky; Thompson, Christopher; Denham, Robert; Haines, Heather; Sharma, Ashneel; Pietsch, Timothy

    2016-04-01

    With access to only limited gauging records (~ 37 years in eastern Australia), Australia like many parts of the globe is heavily constrained in its ability to meaningfully predict the magnitude and frequency of extreme flood events. Flood inundation data gathered during recent floods (2011 and 213) now forms an essential insight into how landscapes may respond to future floods and to guide planning and policy. This study presents the first singe-catchment flood reconstruction analyses in a region of recognised hydrological variability, as characterised by alternating extremes of floods and droughts. The resultant 'Big Flood' data set consists of a unique combination of high-resolution topographic data on landscape changes during recent floods, and a detailed reconstruction of both the timing and estimated magnitude of past food events derived using OSL dating of flood deposits from a range of sedimentary environments. While distinct flood and drought 'phases' are recognisable over the timescale of several thousand years, the extent to which these reflect changes in flood magnitude and/or frequency remains complicated by catchment-specific geomorphology. Issues of flood sample preservation are discussed in this talk within the context of geomorphic setting and notably non-linear variations in the capacity for channel adjustment. This talk outlines the key factors which must be considered in evaluating the role of climate, landuse change and geomorphology in informing flood risk management in Queensland.

  6. 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

  7. Selected fluvial monazite deposits in the southeastern United States

    Science.gov (United States)

    Overstreet, William C.; White, A.M.; Theobald, P.K.; Caldwell, D.W.

    1971-01-01

    Farther southwest in Georgia, around Griffin and Zebullon, along streams tributary to the Flint River in the monazite belt the flood plains are generally small and discontinuous, and only about 1 percent of the sediment is gravel. The area between Griffin, Zebullon, and the Flint River is underlain by biotite schist and biotite gneiss into which biotite granite has been intruded. Only along one stream, Flat Creek, which drains monazite-bearing granite near Zetella, Ga., are the tenors in monazite even moderately high, but a combination of thick, clayey overburden and discontinuous flood plains make the stream unsuitable for placer mining. Elsewhere in the Flint River area the heavy-mineral concentrates contain less than 1 percent monazite. The southwesternmost area in which reconnaissance of the monazite belt was conducted includes a groups of southwest-flowing tributaries to the Chattahoochee River north of Pine Mountain and near La Grange, Ga. A combination of three characteristics of the alluvium make the area unfavorable for mining: (1) the upper half of the sedimentary sequence is clay and silt, (2) there is scant gravel, and (3) much of the sand is fine grained. Monazite is associated with the Snelson Granite, schists, and gneisses north of the Towaliga fault, but even in this area the tenor of most riffle sediments is only 0.1 to 0.5 pound of monazite per cubic yard, and the average tenor of the alluvium is about 0.2 pound per cubic Yard. Rocks south of the Towaliga fault contain scant monazite. The monazite-bearing area in the drainage basin of the Chattahoochee River has no monazite placers. Evidence from the areas on the Flint and Chattahoochee Rivers shows that streams in western Georgia are a much poorer source of monazite than streams farther to the northeast in Georgia, South Carolina, and North Carolina. Also, the northeastern part of the belt in the drainage basins of the Yadkin and Dan Rivers is a poorer source for monazite than the area between

  8. Saturated thickness, High Plains aquifer, 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents the saturated thickness of the High Plains aquifer of the United States, 2009, in feet. The High Plains aquifer underlies...

  9. Flood routing in an ephemeral channel with compound cross-section

    Indian Academy of Sciences (India)

    M BALAMURUGAN; S MURTY BHALLAMUDI

    2016-07-01

    Natural phenomenon of surface and subsurface flow interaction is an intrinsic component of the hydrological processes in any watershed. It is a highly sensitive process, especially in arid and semi-arid regions, and should be considered while dealing with any water management activity in these regions. This paper describes a novel approach for flood routing in an ephemeral channel with compound cross-sections. The proposed mathematical model couples the numerical solution for complete Saint-Venant equations for surfaceflow with the numerical solution for one-dimensional Richards equation for sub-surface flow through an iterative procedure. Recently developed interactive divided channel (IDC) method is incorporated for simulating the main channel and flood plain flow interactions. In the one-dimensional surface and pseudo two-dimensional subsurface (1DSP2DSS) model presented here, the effect of lateral variation in infiltration rate at a cross section arising due to (i) lateral variation in flow depth and (ii) lateral variation in soil characteristics is incorporated by considering infiltration into different soil columns for main channel and flood plains. The proposed model is verified by comparing the model results with those available in literature for benchmark problems Simulations are presented to demonstrate the capability of the model for flood routing in ephemeral channels with flood plains and the effect of lateral variation in infiltration rate on transmission losses.

  10. Challenges of Modeling Flood Risk at Large Scales

    Science.gov (United States)

    Guin, J.; Simic, M.; Rowe, J.

    2009-04-01

    algorithm propagates the flows for each simulated event. The model incorporates a digital terrain model (DTM) at 10m horizontal resolution, which is used to extract flood plain cross-sections such that a one-dimensional hydraulic model can be used to estimate extent and elevation of flooding. In doing so the effect of flood defenses in mitigating floods are accounted for. Finally a suite of vulnerability relationships have been developed to estimate flood losses for a portfolio of properties that are exposed to flood hazard. Historical experience indicates that a for recent floods in Great Britain more than 50% of insurance claims occur outside the flood plain and these are primarily a result of excess surface flow, hillside flooding, flooding due to inadequate drainage. A sub-component of the model addresses this issue by considering several parameters that best explain the variability of claims off the flood plain. The challenges of modeling such a complex phenomenon at a large scale largely dictate the choice of modeling approaches that need to be adopted for each of these model components. While detailed numerically-based physical models exist and have been used for conducting flood hazard studies, they are generally restricted to small geographic regions. In a probabilistic risk estimation framework like our current model, a blend of deterministic and statistical techniques have to be employed such that each model component is independent, physically sound and is able to maintain the statistical properties of observed historical data. This is particularly important because of the highly non-linear behavior of the flooding process. With respect to vulnerability modeling, both on and off the flood plain, the challenges include the appropriate scaling of a damage relationship when applied to a portfolio of properties. This arises from the fact that the estimated hazard parameter used for damage assessment, namely maximum flood depth has considerable uncertainty. The

  11. Widespread Plains Volcanism on Mercury Ended by 3.6 Ga

    Science.gov (United States)

    Byrne, P. K.; Ostrach, L. R.; Fassett, C.; Chapman, C. R.; Evans, A. J.; Klimczak, C.; Banks, M. E.; Head, J. W., III; Solomon, S. C.

    2015-12-01

    The largest volcanic plains deposits on Mercury are situated in its northern hemisphere and include the extensive northern smooth plains and the Caloris interior plains. Crater size-frequency analyses have shown that both deposits were emplaced around 3.8 Ga, for any of the published model production function (MPF) chronologies for impact crater formation on Mercury. The largest volcanic deposit in the southern hemisphere, the Rembrandt interior plains, has a model age of ~3.7 Ga. To test the hypothesis that all major volcanic smooth plains on Mercury were emplaced at about the same time, we determined crater size-frequency distributions for nine additional deposits (see Table 1). The diameters of craters that superpose the smooth plains at each site were measured with CraterTools, yielding crater areal densities in terms of N(10), the number of craters ≥10 km in diameter per 106 km2 area (Table 1). Our crater density measurements span N(10) values of 29-146, a range that encompasses corresponding values for the larger areas of smooth plains. With CraterStats, we fit our data (for craters ≥4 km in diameter) to the MPF chronologies of Le Feuvre and Wieczorek. For porous scaling, the model ages of all nine sites span a narrow window (Table 1). Non-porous scaling fails to match the crater size-frequency distributions. We show that widespread plains volcanism, likely the primary process by which Mercury's crust developed, had ended by 3.6 Ga. Younger volcanic deposits have been identified on the planet, but only within impact structures and at volumes much less than the smallest deposit considered here. Superposition relations between shortening landforms and craters on Mercury indicate that global contraction in response to interior cooling was underway by ~3.6 Ga. The cessation of widespread plains volcanism on Mercury may therefore reflect the onset of a stress state within the planet's lithosphere that inhibited magma ascent. Conversely, mantle thermochemical

  12. 震区山洪泥石流野外监测与侵蚀产沙研究%Field monitoring and erosion-deposition sediment of flash-flood debris flow in suffered areas-a case study at Lianhuaxin Gully

    Institute of Scientific and Technical Information of China (English)

    韩用顺; 黄鹏; 朱颖彦; 胡凯衡

    2012-01-01

      The flash flood and debris flow in the suffered areas by Wenchuan earthquake aroused a wide at⁃tention at home and abroad because of their tremendous damage and frequent occurrence. It is significant to conduct field monitoring of flash flood and debris flow and to study their development features for assur⁃ing public security and preventing flash flood and debris flow. In this paper,Lianhuaxin gully,the epicen⁃ter of Wenchuan Earthquake,was taken as a study area and different kinds of slope debris flow and gully debris flow were selected to make field surveying. Three-level field observation stations and 56 control points were established in different slope, ridge, submit and small watershed of study area. From 2010 to 2012,four large-scale flash-flood debris flows and corresponding slopes,channels,sections and surface de⁃formations were monitored by means of GPS, total station, leveling instrument, 3D-laser scanning system, InSar and high-resolution images. Three-dimension digital terrain models with large scale were set up to study the erosion,development and evolution features of different kinds of debris flows. The paper also dis⁃cussed the fluvial process and erosion-deposition characteristics of flash flood debris flow. The results show that:(1) flash flood and debris flow are still at rapid development stage after earthquake, become more and more frequent and can be monitored through 3S technologie;(2) in the upper reaches of study area, flash-flood debris flow is typical of violent erosion and deposit with serious erosion at the incision ratio of 3.98m/a in the middle and right slope and even with the maximum incision depth of 5m at a debris flow event but with moderate deposit on the left slope;(3) the middle reaches of gully are still characterized by serious erosion with the maximum incision depth of 3m but its intensity decreased with the incision ra⁃tio of 1.23m/a;(4) the lower reaches of gully generally have a moderate erosion with

  13. 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.

  14. 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.

  15. 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.

  16. Magnetic and geochemical signatures of flood layers in lake sediments

    Science.gov (United States)

    Støren, Eivind; Paasche, Øyvind; Hirt, Ann; Kumari, Monika

    2016-04-01

    Floods carry sediments that quickly become deposited whenever rivers meet lakes. In catchments that are subjected to repeated flooding, downstream lakes can therefore contain record of past events across multiple timescales. High-resolution core scanning analyses such as X-ray fluorescence (XRF) scanning and magnetic susceptibility (MS) return data that are frequently used to detect flood layers in soft sediment archives such as lakes, fjords and ocean basins. In order to delineate the copious information that can be extracted from soft sediment records we have explored ways in which high-resolution data can be utilized and subsequently vetted by high-precision measurements. By combining magnetic hysteresis measurements and first-order reversal curves (FORCs) with inductively coupled plasma optical emission spectrometer (ICP-OES) measurements of chemical elements on 36 samples, important information not only about flood dynamics and variability are acquired, but also sources of noise in high-resolution scanning techniques are identified. Specifically, we show that a lake flood record from Southern Norway containing ˜ 100 floods distributed over 10 000 years can be sub-divided into at least two groups, suggested to contain floods generated by spring snow melting and intense summer rainstorms. The temporal evolution of this pattern shows a marked shift towards spring floods around 2000 years ago compared to the earlier part of the record. The approach presented here is of universal character and should be applicable to all kinds of soft sediment archives.

  17. A 2D simulation model for urban flood management

    Science.gov (United States)

    Price, Roland; van der Wielen, Jonathan; Velickov, Slavco; Galvao, Diogo

    2014-05-01

    The European Floods Directive, which came into force on 26 November 2007, requires member states to assess all their water courses and coast lines for risk of flooding, to map flood extents and assets and humans at risk, and to take adequate and coordinated measures to reduce the flood risk in consultation with the public. Flood Risk Management Plans are to be in place by 2015. There are a number of reasons for the promotion of this Directive, not least because there has been much urban and other infrastructural development in flood plains, which puts many at risk of flooding along with vital societal assets. In addition there is growing awareness that the changing climate appears to be inducing more frequent extremes of rainfall with a consequent increases in the frequency of flooding. Thirdly, the growing urban populations in Europe, and especially in the developing countries, means that more people are being put at risk from a greater frequency of urban flooding in particular. There are urgent needs therefore to assess flood risk accurately and consistently, to reduce this risk where it is important to do so or where the benefit is greater than the damage cost, to improve flood forecasting and warning, to provide where necessary (and possible) flood insurance cover, and to involve all stakeholders in decision making affecting flood protection and flood risk management plans. Key data for assessing risk are water levels achieved or forecasted during a flood. Such levels should of course be monitored, but they also need to be predicted, whether for design or simulation. A 2D simulation model (PriceXD) solving the shallow water wave equations is presented specifically for determining flood risk, assessing flood defense schemes and generating flood forecasts and warnings. The simulation model is required to have a number of important properties: -Solve the full shallow water wave equations using a range of possible solutions; -Automatically adjust the time step and

  18. Development of flood index by characterisation of flood hydrographs

    Science.gov (United States)

    Bhattacharya, Biswa; Suman, Asadusjjaman

    2015-04-01

    In recent years the world has experienced deaths, large-scale displacement of people, billions of Euros of economic damage, mental stress and ecosystem impacts due to flooding. Global changes (climate change, population and economic growth, and urbanisation) are exacerbating the severity of flooding. The 2010 floods in Pakistan and the 2011 floods in Australia and Thailand demonstrate the need for concerted action in the face of global societal and environmental changes to strengthen resilience against flooding. Due to climatological characteristics there are catchments where flood forecasting may have a relatively limited role and flood event management may have to be trusted upon. For example, in flash flood catchments, which often may be tiny and un-gauged, flood event management often depends on approximate prediction tools such as flash flood guidance (FFG). There are catchments fed largely by flood waters coming from upstream catchments, which are un-gauged or due to data sharing issues in transboundary catchments the flow of information from upstream catchment is limited. Hydrological and hydraulic modelling of these downstream catchments will never be sufficient to provide any required forecasting lead time and alternative tools to support flood event management will be required. In FFG, or similar approaches, the primary motif is to provide guidance by synthesising the historical data. We follow a similar approach to characterise past flood hydrographs to determine a flood index (FI), which varies in space and time with flood magnitude and its propagation. By studying the variation of the index the pockets of high flood risk, requiring attention, can be earmarked beforehand. This approach can be very useful in flood risk management of catchments where information about hydro-meteorological variables is inadequate for any forecasting system. This paper presents the development of FI and its application to several catchments including in Kentucky in the USA

  19. Nogales flood detention study

    Science.gov (United States)

    Norman, Laura M.; Levick, Lainie; Guertin, D. Phillip; Callegary, James; Guadarrama, Jesus Quintanar; Anaya, Claudia Zulema Gil; Prichard, Andrea; Gray, Floyd; Castellanos, Edgar; Tepezano, Edgar; Huth, Hans; Vandervoet, Prescott; Rodriguez, Saul; Nunez, Jose; Atwood, Donald; Granillo, Gilberto Patricio Olivero; Ceballos, Francisco Octavio Gastellum

    2010-01-01

    Flooding in Ambos Nogales often exceeds the capacity of the channel and adjacent land areas, endangering many people. The Nogales Wash is being studied to prevent future flood disasters and detention features are being installed in tributaries of the wash. This paper describes the application of the KINEROS2 model and efforts to understand the capacity of these detention features under various flood and urbanization scenarios. Results depict a reduction in peak flow for the 10-year, 1-hour event based on current land use in tributaries with detention features. However, model results also demonstrate that larger storm events and increasing urbanization will put a strain on the features and limit their effectiveness.

  20. Flood Risk Assessment as a Part of Integrated Flood and Drought Analysis. Case Study: Southern Thailand

    Science.gov (United States)

    Prabnakorn, Saowanit; Suryadi, Fransiscus X.; de Fraiture, Charlotte

    2015-04-01

    Flood and drought are two main meteorological catastrophes that have created adverse consequences to more than 80% of total casualties universally, 50% by flood and 31% by drought. Those natural hazards have the tendency of increasing frequency and degree of severity and it is expected that climate change will exacerbate their occurrences and impacts. In addition, growing population and society interference are the other key factors that pressure on and exacerbate the adverse impacts. Consequently, nowadays, the loss from any disasters becomes less and less acceptable bringing about more people's consciousness on mitigation measures and management strategies and policies. In general, due to the difference in their inherent characteristics and time occurrences flood and drought mitigation and protection have been separately implemented, managed, and supervised by different group of authorities. Therefore, the objective of this research is to develop an integrated mitigation measure or a management policy able to surmount both problems to acceptable levels and is conveniently monitored by the same group of civil servants which will be economical in both short- and long-term. As aforementioned of the distinction of fundamental peculiarities and occurrence, the assessment processes of floods and droughts are separately performed using their own specific techniques. In the first part of the research flood risk assessment is focused in order to delineate the flood prone area. The study area is a river plain in southern Thailand where flooding is influenced by monsoon and depression. The work is mainly concentrated on physically-based computational modeling and an assortment of tools was applied for: data completion, areal rainfall interpolation, statistical distribution, rainfall-runoff analysis and flow model simulation. The outcome from the simulation can be concluded that the flood prone areas susceptible to inundation are along the riparian areas, particularly at the

  1. Natural Flood Management Plus: Scaling Up Nature Based Solutions to Larger Catchments

    Science.gov (United States)

    Quinn, Paul; Nicholson, Alex; Adams, Russ

    2017-04-01

    It has been established that networks NFM features, such as ponds and wetlands, can have a significant effect on flood flow and pollution at local scales (less than 10km2). However, it is much less certain that NFM and NBS can impact at larger scales and protect larger cities. This is especially true for recent storms in the UK such as storm Desmond that caused devastation across the north of England. It is possible using observed rainfall and runoff data to estimate the amounts of storage that would be required to impact on extreme flood events. Here we will how a toolkit that will estimate the amount of storage that can be accrued through a dense networks of NFM features. The analysis suggest that the use of many hundreds of small NFM features can have a significant impact on peak flow, however we still require more storage in order to address extreme events and to satisfy flood engineers who may propose more traditional flood defences. We will also show case studies of larger NFM feature positioned on flood plains that can store significantly more flood flow. Examples designs of NFM plus feature will be shown. The storage aggregation tool will then show the degree to which storing large amounts of flood flow in NFM plus features can contribute to flood management and estimate the likely costs. Together smaller and larger NFM features if used together can produce significant flood storage and at a much lower cost than traditional schemes.

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

    Science.gov (United States)

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

    2016-04-01

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

  3. A remote sensing approach for connecting the historic 2011 Mississippi River flood to wetland sedimentation on the Delta

    Science.gov (United States)

    Falcini, Federico; Colella, Simone; Volpe, Gianluca; Khan, Nicole; Macelloni, Leonardo; Santoleri, Rosalia; Horton, Benjamin; Jerolmack, Douglas

    2013-04-01

    Wetlands in the Mississippi River deltaic plain are deteriorating in part because levees and control structures starve them of sediment. In Spring of 2011 a record breaking flood brought discharge on the lower Mississippi River to dangerous levels, forcing managers to divert additional water to the adjacent Atchafalaya River Basin. Here we quantify differences between the Mississippi and Atchafalaya River inundation and sediment-plume patterns using field-calibrated satellite data, and assess the impact these outflows had on wetland sedimentation. Since standard products available from MyOcean were not suitable for this purpose an ad hoc processing was developed to establish a relationship between field suspended sediment concentration (SSC) data and the corrected MODIS reflectance at 645 nm. We show that the focused, high-momentum jet from the leveed Mississippi delivered sediment far offshore. In contrast, the plume from the Atchafalaya was more diffuse; diverted water inundated a large area, and sediment was trapped within the coastal current. Maximum sedimentation (up to several centimetres) occurred in the Atchafalaya Basin despite the larger sediment load carried by the Mississippi. Little accumulation occurred along the shoreline between these river sources. The correspondence between zones of high shoreline deposition, and coastal SSC patterns indentified from satellite data, is strongly suggestive of plume-derived deposition on marshes. Our findings allow us to set an hydrodynamic theory that provides a mechanistic link between river-mouth dynamics and wetland sedimentation patterns, which is relevant for plans to restore deltaic wetlands.

  4. El Niño floods and culture change: A late Holocene flood history for the Rio Moquegua, southern Peru

    Science.gov (United States)

    Magilligan, Francis J.; Goldstein, Paul S.

    2001-05-01

    The 1997 1998 El Niño generated large floods throughout southern Peru, especially in inland locations along Rio Moquegua. Using remote sensing, hydraulic modeling, field surveying, and stratigraphic analyses, we estimate the magnitude and frequency of this flood and determine a late Holocene flood history for main- stem and tributary sections. Modeling indicates a peak discharge of 450 m3/s for the 1998 flood, with an estimated recurrence interval between 50 and 100 yr. Flood deposits for two large events, dated to A.D. 690 and A.D. 1300, respectively, exist in a small tributary system. Tiwanaku site abandonment (ca. A.D. 1000) predates the younger flood, indicating that stratigraphically recognizable El Niño driven floods were not a causal mechanism for abandonment. Although possessing three flood units, main-stem alluvium is considerably younger (<320 14C yr B.P.) than tributary alluvium, evidencing the major channel widening and lateral reworking of the main stem.

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

    Science.gov (United States)

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

    2017-06-14

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

  6. Detailed Analysis of the Intra-Ejecta Dark Plains of Caloris Basin, Mercury

    Science.gov (United States)

    Buczkowski, Debra L.; Seelos, K. S.

    2010-01-01

    The Caloris basin on Mercury is floored by light-toned plains and surrounded by an annulus of dark-toned material interpreted to be ejecta blocks and smooth, dark, ridged plains. Strangely, preliminary crater counts indicate that these intra-ejecta dark plains are younger than the light-toned plains within the Caloris basin. This would imply a second, younger plains emplacement event, possibly involving lower albedo material volcanics, which resurfaced the original ejecta deposit. On the other hand, the dark plains may be pre-Caloris light plains covered by a thin layer of dark ejecta. Another alternative to the hypothesis of young, dark volcanism is the possibility that previous crater counts have not thoroughly distinguished between superposed craters (fresh) and partly-buried craters (old) and therefore have not accurately determined the ages of the Caloris units. This abstract outlines the tasks associated with a new mapping project of the Caloris basin, intended to improve our knowledge of the geology and geologic history of the basin, and thus facilitate an understanding of the thermal evolution of this region of Mercury.

  7. [Growth patterns of Leymus chinensis clones under different habitat conditions in Songnen Plain of China].

    Science.gov (United States)

    Yang, Yunfei; Zhang, Baotian

    2006-08-01

    A tracking investigation was conducted in the Songnen Plain of China on the experimental clones of Leymus chinensis under cultivation, and the natural clones of this grass in the succession process of vegetation restoration after meadow flooding. The results showed that on aeolian sandy soil where existed enough growth space but no interspecific competition, there was a month interval between the transplanting of two experimental clones, and the sizes of these clones had a one-fold difference by the end of next growth season. During the whole growth season, the vegetative reproduction of the two experimental clones followed the same exponential pattern. After 6 years restoration succession on flooded meadow, the vegetative reproduction of clonal populations in L. chinensis + Carex duriuscula and L. chinensis + weed communities were all accorded with power function. On flooded alkaline meadow where existed interspecific competition, the natural clones could still increase their offspring numbers exponentially, and quickly expand their niche space at the same time.

  8. Novel early flood warning in the Huaihe River basin in east-central China using the TIGGE database

    Science.gov (United States)

    He, Y.; Cloke, H.; Li, Z.; Wetterhall, F.; Pappenberger, F.

    2009-04-01

    Flooding is a wide spread and devastating natural disaster worldwide. Floods that took place in the last decade in China were ranked the worst amongst recorded floods worldwide in terms of the number of human fatalities and economic losses (Munich Re-Insurance). Rapid economic development and population expansion into low lying flood plains has worsened the situation. The last decade has seen an increase in flood preparedness across all levels of society in China. Current conventional flood prediction systems in China are neither suited to the perceptible climate variability nor the rapid pace of urbanization sweeping the country. Flood prediction systems from short-term (a few hours) to medium-term (a few days) need to be revisited and adapted to changing socio-economic and hydro-climatic realities. The latest technology requires implementation of multiple numerical weather prediction systems. The availability of a number of global ensemble weather prediction systems through the ‘THORPEX Interactive Grand Global Ensemble' (TIGGE) offers a good opportunity for an effective state-of-the-art early forecasting system. A prototype of a Novel Flood Early Warning System (NEWS) using the TIGGE database is tested in the Huai River basin located in east-central China. It is the first early flood warning system in China that uses the massive TIGGE database cascaded with river catchment models, the Xinanjiang model and a 1-D hydraulic model, to predict river discharge and flood inundation. Results from selected flood events will be presented.

  9. Flood risk on the Black sea coast of Russia

    Science.gov (United States)

    Alekseevsky, Nikolay; Magritsky, Dmitry; Koltermann, Peter; Krylenko, Inna; Umina, Natalya; Aybulatov, Denis; Efremova, Natalya; Lebedeva, Seraphima

    2013-04-01

    The data of unique database "Floods in the coastal zones of Europeans part of Russia", developed by authors, are shown, that frequency of floods and damage in the coastal zones are growing. There is most dangerous situation on the Black sea coast of Russia. Here the main part of settlements, resorts and industry is situated in the river valleys and mouths. All main roads and pipelines cross the river channels. The Black sea rivers have flood regime with high intensity of flood formations and huge destructive flood power. Despite prevalence of floods during the cold period of year the most part of high floods in 100 years of supervision was noted here in the summer-fall (65% in July-October). Usually they were induced by the showers connected with passing of powerful cyclones, atmospheric fronts, and water tornadoes. The insignificant part of floods was connected with snow melting, backwater phenomena, showers in the cities and dam breaks. Thus shower induced floods here are the most widespread and destructive. Usually they arise within two-three watersheds simultaneously. Formation catastrophic heavy rain flood is possible on any site of a river valley of the Black Sea coast. The wave of a high water moves with very high speed, carrying a large number of deposits and garbage. To the mouth the flood can be transformed into debris flow. The water levels during a high water period rise on 3-6 m in the channels, and up to 11-12 m in the river canyons; the maximum depths of flow on the floodplains are 3 m and more. Flooding depths, induced by slope streams, can be to 0,5 m and higher. Flooding proceeds only some hours. After that water rather quickly flows down from a floodplains to the bed of the rivers and into the sea, leaving traces of destructions, a powerful layer of deposits (to 10-20 cm and more) and garbage. In the mouth river deposits quite often form the river mouth bar which is washed away during next storms. The damage from river floods on the Black Sea

  10. Sedimentary record of Warta river floods in summer 2010 and winter 2011 nearby Poznan, W Poland

    Science.gov (United States)

    Skolasińska, Katarzyna; Szczuciński, Witold; Mitręga, Marta; Rotnicka, Joanna; Jagodziński, Robert; Lorenc, Stanisław

    2013-04-01

    The Warta River valley nearby Poznań (W Poland) represents a meandering lowland river changed during the last 150 years by hydro-engineering works. Floods represent a major natural hazard in the region. However, historical records are not complete - particularly for former rural areas. Thus, sedimentary record may potentially offer additional insights into the flooding history. The big floods in the summer 2010 (the largest during the last 31 years) and winter 2011 offered opportunity to study their sedimentary record. The particular purposes were to identify sedimentary characteristics of summer and winter floods, interpret various phases of particular floods in the record, and assess impact of early post-depositional changes of the flood deposits. The surveys were conducted in six areas just after the floods and were repeated after several months, one and two years. The deposits spatial extent, thickness, surface bedforms and sediment type were assessed in the field. Sediment samples were further investigated for grain size distribution, organic matter content, roundness and sand grains surface features (SEM). The sandy flood deposits mostly build natural levee, side bars (climbing ripple lamination and planar cross laminations (only in crevasse splays). Vertical grain size changes in levee deposits revealed pensymmetric and/or reverse grading interpreted as effect of changing velocity during the rising water level. The sand grains were similar to the river channel sands and dominated by polished and sub-rounded quartz grains with preserved dissolution and dulled surface microfeatures. Further from the channel bank (few to few hundreds of meters) only discontinuous up to few mm thick organic rich mud layer was left, which after the summer flood was covered by algal mats. However the mud and mats were quickly reworked by new vegetation. The follow up surveys revealed that the preservation potential of flood deposits is low to moderate (only for sandy deposits

  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. 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

  13. 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.

  14. Thickness and potential well yield of the stratified deposits in the Croton River Basin, Putnam County, New York

    Science.gov (United States)

    Irwin, Don J.

    1988-01-01

    In 1986, the U.S. Geological Survey (USGS), in cooperation with the Putnam County, NY Department of Health, reviewed and compiled all available well information and aerial photographs to plot: (1) the locations of the wells and springs currently on file with USGS, and (2) the thickness and potential well yield of the stratified deposits in the county. These deposits consist either of glacial sand and gravel that lie primarily in glacially enlarged valleys, or of recent accumulations of clay, sand, and organic material on flood plains and within local depressions. Plate 1 shows the locations of all wells and springs in the area that are currently on file in USGS 's computerized data base; both bedrock wells and wells that tap till or stratified material are included. Also shown are the locations and depths of the wells, the reported depth to bedrock and yield, and the yield of all springs. Plate 2 shows the thickness of the stratified deposits as determined from logs of wells that were drilled through it; plate 3 shows the amount of water that a stratified deposit may be expected to yield to a new well. These estimates are based on the reported yields of the compiled wells. (Lantz-PTT)

  15. The Terrible Flood

    Institute of Scientific and Technical Information of China (English)

    Dorine; Houston

    1998-01-01

    Dear Xiao Lan. ’Several times a week, no matter which of the major television news networksI turn to, the screen is filled with tragic pictures of flooding along the YangtzeRiver, and I grieve for the suffering people whose lives are being so terriblydisrupted by this disaster. Even more to be grieved is the terrible number of peoplewho have been killed by the floods and their effects.

  16. The application of enhanced conveyance calculations in flood prediction

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, G.; Pender, G. [Glasgow Univ. (United Kingdom). Dept. of Civil Engineering

    2000-07-01

    Over the past twenty years extensive research has been conducted on overbank flow behaviour during river floods. When the main channel flow interacts with flood plain flow, secondary losses other than bed friction act to retard the flow. Traditional one-dimensional modelling tools commonly used in the UK, such as ISIS or HEC-RAS, currently take no account of these secondary losses In an attempt to establish the nature and significance of secondary losses the flood channel facility (FCF) was constructed at HR Wallingford in 1987. As a direct result of the meandering channel series B experiments the James and Wark Method (1992) was developed to predict stage discharge relationships. For a given water level, this method will calculate a value of discharge taking into account the secondary losses. The paper will report on the modification of the method to fit into the river modelling software ISIS. Within the ISIS framework the James and Wark Method is used to calculate conveyance. The aim is to produce a more accurate flood prediction tool than currently exists. The newly developed software has been tested on laboratory data and shown to be highly accurate in both stage discharge and water level prediction. The software has since been applied to natural rivers that have experienced significant flood events. The paper will illustrate the significance of applying flume based conveyance calculation methods at the field scale. (orig.)

  17. Deposición transversal de líquido de las boquillas de doble abanico TTJ60-11004 y TTJ60-11002 en distintas condiciones operacionales The transversal spray deposition of double plain spurt nozzles TTJ60-11004 and TTJ60-11002 in different operational conditions

    Directory of Open Access Journals (Sweden)

    R.G. Viana

    2009-06-01

    Full Text Available El objetivo de este trabajo fue el de evaluar la deposición transversal de caldo de las boquillas pulverizadoras de doble abanico TTJ60-11004 y TTJ60-11002 en distintas condiciones operacionales. Se utilizaron 5 muestras de cada boquilla pulverizadora siendo considerada cada unidad, una repetición. La distribución de caldo fue evaluada por medio de una mesa de evaluación de distribución construida de acuerdo con la norma ISO 56821. Se evaluó el perfil de distribución individual, la distribución volumétrica simulada de la superposición de los chorros por medio del coeficiente de variación (CV% de los volúmenes colectados, el caudal y el ángulo de abertura de los chorros. Las condiciones operacionales fueron: presión de trabajo de 200, 300 y 400 Kpa, altura de 30, 40 y 50 cm en relación al blanco y espaciamiento entre boquillas simulados en Software (Microsoft Excel entre 45 y 100 cm. Las boquillas presentaron perfil individual descontinuo con la mayor deposición de líquido en la región central y reducción del volumen gradual en dirección a las extremidades. El aumento de la presión promovió alargamiento del perfil y de la franja de aplicación. Las boquillas proporcionaron perfil uniforme que dependió del espaciamiento entre las boquillas, con valores menores con reducción en el espaciamiento y en presiones mayores. El caudal y el ángulo del chorro aumentaron con el incremento en la presión.The objective of this work was evaluate the transversal spray deposition of double plain spurt nozzles TTJ60-11004 and TTJ60-11002 in different operational conditions. Was used five samples of each nozzle and considerate a unite one repetition. The spray deposition was evaluate on a table of evaluation distribution constructed in accordance with norm ISO 5682-1. Was evaluate a single spray distribution, volumetric distribution of the overlapping spurts by means of the coefficient of variation (CV%, outflow and angle of opening of the

  18. Frequent floods in the European Alps coincide with cooler periods of the past 2500 years.

    Science.gov (United States)

    Glur, Lukas; Wirth, Stefanie B; Büntgen, Ulf; Gilli, Adrian; Haug, Gerald H; Schär, Christoph; Beer, Jürg; Anselmetti, Flavio S

    2013-09-26

    Severe floods triggered by intense precipitation are among the most destructive natural hazards in Alpine environments, frequently causing large financial and societal damage. Potential enhanced flood occurrence due to global climate change would thus increase threat to settlements, infrastructure, and human lives in the affected regions. Yet, projections of intense precipitation exhibit major uncertainties and robust reconstructions of Alpine floods are limited to the instrumental and historical period. Here we present a 2500-year long flood reconstruction for the European Alps, based on dated sedimentary flood deposits from ten lakes in Switzerland. We show that periods with high flood frequency coincide with cool summer temperatures. This wet-cold synchronism suggests enhanced flood occurrence to be triggered by latitudinal shifts of Atlantic and Mediterranean storm tracks. This paleoclimatic perspective reveals natural analogues for varying climate conditions, and thus can contribute to a better understanding and improved projections of weather extremes under climate change.

  19. Flood Bypass Capacity Optimization

    Science.gov (United States)

    Siclari, A.; Hui, R.; Lund, J. R.

    2015-12-01

    Large river flows can damage adjacent flood-prone areas, by exceeding river channel and levee capacities. Particularly large floods are difficult to contain in leveed river banks alone. Flood bypasses often can efficiently reduce flood risks, where excess river flow is diverted over a weir to bypasses, that incur much less damage and cost. Additional benefits of bypasses include ecosystem protection, agriculture, groundwater recharge and recreation. Constructing or expanding an existing bypass costs in land purchase easements, and levee setbacks. Accounting for such benefits and costs, this study develops a simple mathematical model for optimizing flood bypass capacity using benefit-cost and risk analysis. Application to the Yolo Bypass, an existing bypass along the Sacramento River in California, estimates optimal capacity that economically reduces flood damage and increases various benefits, especially for agriculture. Land availability is likely to limit bypass expansion. Compensation for landowners could relax such limitations. Other economic values could affect the optimal results, which are shown by sensitivity analysis on major parameters. By including land geography into the model, location of promising capacity expansions can be identified.

  20. Explorers Presentation: Flooding and Coastal Communities

    OpenAIRE

    Institute, Marine

    2015-01-01

    : Explorers Flooding and Coastal Communities presentation provides an introduction to flooding. This can be used with the lesson plan on building flood defences. It covers: What is a flood? Why does it flood? Where does the water come from? The water cycle; Where is water stored? Examples of Pluvial vs. Coastal flooding; Impacts of flooding; Flood defences; What else influences flooding - Human impacts, Urbanisation, Deforestation, Sea level rise

  1. LAND SUITABILITY SCENARIOS FOR ARID COASTAL PLAINS USING GIS MODELING: SOUTHWESTERN SINAI COASTAL PLAIN, EGYPT

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Wahid

    2009-12-01

    Full Text Available Site selection analysis was carried out to find the best suitable lands for development activities in an example of promising coastal plains, southwestern Sinai, Egypt. Two GIS models were developed to represent two scenarios of land use suitability in the study area using GIS Multi Criteria Analysis Modeling. The factors contributed in the analysis are the Topography, Land cover, Existing Land use, Flash flood index, Drainage lines and Water points. The first scenario was to classify the area according to various gradual ranges of suitability. According to this scenario, the area is classified into five classes of suitability. The percentage of suitability values are 51.16, 6.13, 22.32, 18.49 and 1.89% for unsuitable, least suitable, low suitable, suitable and high suitable, respectively. The second scenario is developed for a particular kind of land use planning; tourism and recreation projects. The suitability map of this scenario was classified into five values. Unsuitable areas represent 51.18% of the study area, least suitable 16.67%, low suitable 22.85%, suitable 8.61%, and high suitable 0.68%. The best area for locating development projects is the area surrounding El-Tor City and close to the coast. This area could be an urban extension of El-Tor City with more economical and environmental management.

  2. LAND SUITABILITY SCENARIOS FOR ARID COASTAL PLAINS USING GIS MODELING: SOUTHWESTERN SINAI COASTAL PLAIN, EGYPT

    Directory of Open Access Journals (Sweden)

    Ahmed Wahid

    2009-01-01

    Full Text Available Site selection analysis was carried out to find the best suitable lands for development activities in an example of promising coastal plains, southwestern Sinai, Egypt. Two GIS models were developed to represent two scenarios of land use suitability in the study area using GIS Multi Criteria Analysis Modeling. The factors contributed in the analysis are the Topography, Land cover, Existing Land use, Flash flood index, Drainage lines and Water points. The first scenario was to classify the area according to various gradual ranges of suitability. According to this scenario, the area is classified into five classes of suitability. The percentage of suitability values are 51.16, 6.13, 22.32, 18.49 and 1.89% for unsuitable, least suitable, low suitable, suitable and high suitable, respectively. The second scenario is developed for a particular kind of land use planning; tourism and recreation projects. The suitability map of this scenario was classified into five values. Unsuitable areas represent 51.18% of the study area, least suitable 16.67%, low suitable 22.85%, suitable 8.61%, and high suitable 0.68%. The best area for locating development projects is the area surrounding El-Tor City and close to the coast. This area could be an urban extension of El-Tor City with more economical and environmental management.

  3. Plain Polynomial Arithmetic on GPU

    Science.gov (United States)

    Anisul Haque, Sardar; Moreno Maza, Marc

    2012-10-01

    As for serial code on CPUs, parallel code on GPUs for dense polynomial arithmetic relies on a combination of asymptotically fast and plain algorithms. Those are employed for data of large and small size, respectively. Parallelizing both types of algorithms is required in order to achieve peak performances. In this paper, we show that the plain dense polynomial multiplication can be efficiently parallelized on GPUs. Remarkably, it outperforms (highly optimized) FFT-based multiplication up to degree 212 while on CPU the same threshold is usually at 26. We also report on a GPU implementation of the Euclidean Algorithm which is both work-efficient and runs in linear time for input polynomials up to degree 218 thus showing the performance of the GCD algorithm based on systolic arrays.

  4. Southern Great Plains Safety Orientation

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, John

    2014-05-01

    Welcome to the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARM) Southern Great Plains (SGP) site. This U.S. Department of Energy (DOE) site is managed by Argonne National Laboratory (ANL). It is very important that all visitors comply with all DOE and ANL safety requirements, as well as those of the Occupational Safety and Health Administration (OSHA), the National Fire Protection Association, and the U.S. Environmental Protection Agency, and with other requirements as applicable.

  5. Processes affecting coastal wetland loss in the Louisiana deltaic plain

    Science.gov (United States)

    Williams, S. Jeffress; Penland, Shea; Roberts, Harry H.

    1993-01-01

    Nowhere are the problems of coastal wetland loss more serious and dramatic than in the Mississippi River deltaic plain region of south-central Louisiana. In that area, rates of shoreline erosion of 20 m.yr and loss of land area of up to 75 km/yr result from a complex combination of natural (delta switching, subsidence, sea-level rise, storms) and human (flood control, navigation, oil and gas development, land reclamation) factors. The U.S. Geological Survey (USGS), as part of the National Coastal Geology Program, has undertaken joint filed investigations with Federal, State, and university partners. The objective of these long-term studies is to gather and interpret baseline information in order to improve our scientific understanding of the critical processes and responses responsible for creation, maintenance, and deterioration of coastal wetlands.

  6. Variability of summer-time precipitation in Danube plain, Bulgaria

    Directory of Open Access Journals (Sweden)

    Nikolova Nina

    2005-01-01

    Full Text Available Over the recent years the climate extremes like as drought and floods become more often and have negative impact on human society. That is way it is very important to know the peculiarities of precipitation variability. The paper investigates precipitation variability during summer time in one of the most important agriculture region in Bulgaria - Danube Plain. The summer-time is determined for the period May - October. The study is based on monthly precipitation total for the period 1961-2005. The precipitation variability is analyzed by comparison with the period 1961-1990, determined by World Meteorological Organization as "contemporary climate". In order to investigate the precipitation variability the various indices lake as Percent of Normal, Rainfall Anomaly Index and Cumulative Anomaly have been calculated. Two wet spells (1865-1983 and 1993-2005 and one dry spell (1983-1993 have been identified. The Kriging interpolation has been applied for presenting special distribution of precipitation variability.

  7. Magnetic and geochemical signatures of flood layers in a lake system

    Science.gov (United States)

    Støren, Eivind W. N.; Paasche, Øyvind; Hirt, Ann M.; Kumari, Monika

    2016-10-01

    River floods holds the capasity to erode and transport sediments that are deposited whenever the discharge is reduced. In catchments that are subjected to repeated flooding, downstream lakes can therefore contain a record of past events across multiple timescales. High-resolution core scanning analyses, such as X-ray fluorescence (XRF) scanning and magnetic susceptibility (MS) provide data that are frequently used to detect flood layers in soft sediment archives, such as lakes, fjords and ocean basins. Deposits of past floods also can potentially reveal information about the evolution of flood events as well as source area. Here we explore ways in which subtle variability in high-resolution data can be utilized and subsequently vetted by high-precision measurements in order to delineate the copious information that can be extracted from soft sediment records. By combining magnetic hysteresis measurements and first-order reversal curves (FORCs) with inductively coupled plasma optical emission spectrometer (ICP-OES) measurements of chemical elements on 36 samples, questions about flood dynamics and variability are raised, and also sources of noise in high-resolution scanning techniques are discussed. Specifically, we show that a lake flood record from Southern Norway containing 92 floods distributed over 10,000 years can be subdivided into two groups of floods that were generated either by spring snow melting, intense summer rainstorms, or a combination of both. The temporal evolution of this pattern shows a marked shift toward spring floods around 2000 years ago compared to the earlier part of the record.

  8. ANALYSIS OF THE PROCESSES AND TRANSFORMATIONS OF THE DENUNDATION VALLEYS IN THE BIELSK PLAIN

    Directory of Open Access Journals (Sweden)

    Krzysztof Micun

    2015-07-01

    Full Text Available The aim of the study was to recognise natural and anthropogenic transformations taking place in small denudation valleys in the old glacial landscape of the Bielsk Plain. The changes are registered in sediments of the valleys. The Bielsk Plain area situated in the north of Bielsk Podlaski is characterized by the presence of latitudinal running denudation valleys, that end with concave broadenings in their headwaters. The geological structure is dominated by silt deposits of various origins. Tills are present in the hilltops while organic and organo-mineral deposits in the depressions. The thickness of the deluvial deposits in the valleys reaches 2 m though usually it does not exceed 1 m. The deposits are mostly silts that developed lithologically as sandy dust and loam dust. Colluvium sedimentation in the valleys clearly correlates with the development of agriculture, deforestation and farming in the area. The abandonment of the cultivation causes significant slowdown in the pace of accumulation of colluvium sediments.

  9. 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

  10. Flood Risk Analysis and Flood Potential Losses Assessment

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The heavy floods in the Taihu Basin showed increasing trend in recent years. In thiswork, a typical area in the northern Taihu Basin was selected for flood risk analysis and potentialflood losses assessment. Human activities have strong impact on the study area' s flood situation (asaffected by the polders built, deforestation, population increase, urbanization, etc. ), and havemade water level higher, flood duration shorter, and flood peaks sharper. Five years of differentflood return periods [(1970), 5 (1962), 10 (1987), 20 (1954), 50 (1991)] were used to cal-culate the potential flood risk area and its losses. The potential flood risk map, economic losses,and flood-impacted population were also calculated. The study's main conclusions are: 1 ) Humanactivities have strongly changed the natural flood situation in the study area, increasing runoff andflooding; 2) The flood risk area is closely related with the precipitation center; 3) Polder construc-tion has successfully protected land from flood, shortened the flood duration, and elevated waterlevel in rivers outside the polders; 4) Economic and social development have caused flood losses toincrease in recent years.

  11. Probabilistic flood extent estimates from social media flood observations

    Science.gov (United States)

    Brouwer, Tom; Eilander, Dirk; van Loenen, Arnejan; Booij, Martijn J.; Wijnberg, Kathelijne M.; Verkade, Jan S.; Wagemaker, Jurjen

    2017-05-01

    The increasing number and severity of floods, driven by phenomena such as urbanization, deforestation, subsidence and climate change, create a growing need for accurate and timely flood maps. In this paper we present and evaluate a method to create deterministic and probabilistic flood maps from Twitter messages that mention locations of flooding. A deterministic flood map created for the December 2015 flood in the city of York (UK) showed good performance (F(2) = 0.69; a statistic ranging from 0 to 1, with 1 expressing a perfect fit with validation data). The probabilistic flood maps we created showed that, in the York case study, the uncertainty in flood extent was mainly induced by errors in the precise locations of flood observations as derived from Twitter data. Errors in the terrain elevation data or in the parameters of the applied algorithm contributed less to flood extent uncertainty. Although these maps tended to overestimate the actual probability of flooding, they gave a reasonable representation of flood extent uncertainty in the area. This study illustrates that inherently uncertain data from social media can be used to derive information about flooding.

  12. Assessment of undiscovered sandstone-hosted uranium resources in the Texas Coastal Plain, 2015

    Science.gov (United States)

    Mihalasky, Mark J.; Hall, Susan M.; Hammarstrom, Jane M.; Tureck, Kathleen R.; Hannon, Mark T.; Breit, George N.; Zielinski, Robert A.; Elliott, Brent

    2015-12-02

    The U.S. Geological Survey estimated a mean of 220 million pounds of recoverable uranium oxide (U3O8 ) remaining as potential undiscovered resources in southern Texas. This estimate used a geology-based assessment method for Tertiary sandstone-hosted uranium deposits in the Texas Coastal Plain sedimentary strata (fig.1).

  13. Crowdsourcing detailed flood data

    Science.gov (United States)

    Walliman, Nicholas; Ogden, Ray; Amouzad*, Shahrzhad

    2015-04-01

    Over the last decade the average annual loss across the European Union due to flooding has been 4.5bn Euros, but increasingly intense rainfall, as well as population growth, urbanisation and the rising costs of asset replacements, may see this rise to 23bn Euros a year by 2050. Equally disturbing are the profound social costs to individuals, families and communities which in addition to loss of lives include: loss of livelihoods, decreased purchasing and production power, relocation and migration, adverse psychosocial effects, and hindrance of economic growth and development. Flood prediction, management and defence strategies rely on the availability of accurate information and flood modelling. Whilst automated data gathering (by measurement and satellite) of the extent of flooding is already advanced it is least reliable in urban and physically complex geographies where often the need for precise estimation is most acute. Crowdsourced data of actual flood events is a potentially critical component of this allowing improved accuracy in situations and identifying the effects of local landscape and topography where the height of a simple kerb, or discontinuity in a boundary wall can have profound importance. Mobile 'App' based data acquisition using crowdsourcing in critical areas can combine camera records with GPS positional data and time, as well as descriptive data relating to the event. This will automatically produce a dataset, managed in ArcView GIS, with the potential for follow up calls to get more information through structured scripts for each strand. Through this local residents can provide highly detailed information that can be reflected in sophisticated flood protection models and be core to framing urban resilience strategies and optimising the effectiveness of investment. This paper will describe this pioneering approach that will develop flood event data in support of systems that will advance existing approaches such as developed in the in the UK

  14. Winter and summer-autumn flash floods as "drivers" of drought and seasonal flood characteristics (case study of European Russia)

    Science.gov (United States)

    Kireeva, Maria; Frolova, Natalia; Rets, Ekaterina; Ezerova, Natalia

    2016-04-01

    The presence of occasional flood periods on rivers is a typical feature of the hydrological regime of European Russia. Despite the fact that the main high-water phase of a hydrological year here is related to spring, flash floods in other seasons play an equally important role. For example, increased water content during autumn determines soil moisture content that determines the loss of runoff during spring flood. Winter floods caused by thaws result in a significant drawdown of a snow pack. And when it is followed by a return of cold weather an ice crust is formed on the surface of snowpack that significantly reduces rates of melt water filtration process.In recent decades, most of the rivers in the European part of Russia have experienced a significant increase of occasional flood flow share in total annual runoff. For example, in the Don basin this parameter has increased by almost 2 times, in the basin of Oka by 1.5. Though less intense, these trends can be traced in the eastern part of the region - in the basins of Kama and Vyatka. The increase here can is approximately 15-20%. In the north of the Eastern Plain (North Dvina, etc.) this tendency isn't observed. The number of flood waves has several times increased. Until 1970s 1-3 occasional floods a year were generally observed on the rivers of Central and Southern Russia. In the past three decades almost every year there are from 4 to 8 or more periods of high water. They are superimposed on each other, as well as the phase of the spring flood and low flow period. The ratio of the maximum discharge of occasional flood to maximum discharge of seasonal flood has increased several times. Now some outstanding floods can be compared with the spring flood wave or even exceed it.Thus, through winter floods an "interception" of spring flood runoff occurs. Spring floods have a lower height and volume and as a result they don't fully recharge a basin. Dry period in this case begins much earlier and though the moisture

  15. Risk assessment and validation of flood disaster based on fuzzy mathematics

    Institute of Scientific and Technical Information of China (English)

    Weiguo Jiang; Lei Deng; Luyao Chen; Jianjun Wu; Jing Li

    2009-01-01

    Floods often take place around rivers and plains, which indicates a higher risk of flooding in these areas. This paper adopts fuzzy comprehensive assessment (FCA), simple fuzzy classification (SFC), and the fuzzy similarity method (FSM) to assess flood disaster risk in Kelantan, Malaysia. Validation data, such as the flooded area, paddy area, urban area, residential area, and refuges, were overlaid to validate and analyze the accuracy of flood disaster risk. The results show that (1) 70-75% of flooded areas lie within the higher and high-est risk zones, which shows an effective assessment accuracy; (2) paddy, built-up, and residential areas concentrated in the higher and highest risk zones are more likely to be destroyed by flood disasters; (3) 200-225 refuges in the higher and highest risk zones account for around 50% of all refuges, which means that more refuges should be built in the higher and highest risk zones to meet the accom-modation requirement; (4) three methods proved to be feasible and effective in evaluating flood disaster risk, among which FCA is more suitable for the study area than the two other methods.

  16. Incorporating river morphological changes to flood risk assessment: uncertainties, methodology and application

    Directory of Open Access Journals (Sweden)

    C. Neuhold

    2009-05-01

    Full Text Available Risk zonation maps are mostly derived from design floods which propagate through the study area. The respective delineation of inundated flood plains is a fundamental input for the flood risk assessment of exposed objects. It is implicitly assumed that the river morphology will not vary, even though it is obvious that the river bed elevation can quickly and drastically change during flood events. The objectives of this study were to integrate the river bed dynamics into the flood risk assessment procedure and to quantify associated uncertainties. The proposed concept was applied to the River Ill in the Western Austrian Alps. In total, 138 flood and associated sediment transport scenarios were considered, simulated and illustrated for the main river stem. The calculated morphological changes of the river bed at the moment of peak flow provided a basis to estimate the variability of possible water surface levels and inundation lines which should be incorporated into flood hazard assessment. In the context of vulnerability assessment an advanced methodological approach to assess flood risk based on damage probability functions is described.

  17. Vistula River bed erosion processes and their influence on Warsaw's flood safety

    Science.gov (United States)

    Magnuszewski, A.; Moran, S.

    2015-03-01

    Large cities have historically been well protected against floods as a function of their importance to society. In Warsaw, Poland, located on a narrow passage of the Vistula River valley, urban flood disasters were not unusual. Beginning at the end of the 19th century, the construction of river embankment and training works caused the narrowing of the flood passage path in the downtown reach of the river. The process of bed erosion lowered the elevation of the river bed by 205 cm over the 20th century, and the consequences of bed lowering are reflected by the rating curve change. Conditions of the flood passage have been analysed by the CCHE2D hydrodynamic model both in retro-modelling and scenario simulation modelling. The high water mark of the 1844 flood and iterative calculations in retro-modelling made possible estimation of the discharge, Q = 8250 m3 s-1. This highest observed historical flood in a natural river has been compared to recent conditions of the Vistula River in Warsaw by scenario modelling. The result shows dramatic changes in water surface elevation, velocities, and shear stress. The vertical velocity in the proximity of Port Praski gauge at km 513 can reach 3.5 m s-1, a very high value for a lowland river. The average flow conveyance is improving due to channel erosion but also declining in the case of extreme floods due to high resistance from vegetation on the flood plains.

  18. A fuzzy Bayesian approach to flood frequency estimation with imprecise historical information

    Science.gov (United States)

    Salinas, José Luis; Kiss, Andrea; Viglione, Alberto; Viertl, Reinhard; Blöschl, Günter

    2016-09-01

    This paper presents a novel framework that links imprecision (through a fuzzy approach) and stochastic uncertainty (through a Bayesian approach) in estimating flood probabilities from historical flood information and systematic flood discharge data. The method exploits the linguistic characteristics of historical source material to construct membership functions, which may be wider or narrower, depending on the vagueness of the statements. The membership functions are either included in the prior distribution or the likelihood function to obtain a fuzzy version of the flood frequency curve. The viability of the approach is demonstrated by three case studies that differ in terms of their hydromorphological conditions (from an Alpine river with bedrock profile to a flat lowland river with extensive flood plains) and historical source material (including narratives, town and county meeting protocols, flood marks and damage accounts). The case studies are presented in order of increasing fuzziness (the Rhine at Basel, Switzerland; the Werra at Meiningen, Germany; and the Tisza at Szeged, Hungary). Incorporating imprecise historical information is found to reduce the range between the 5% and 95% Bayesian credibility bounds of the 100 year floods by 45% and 61% for the Rhine and Werra case studies, respectively. The strengths and limitations of the framework are discussed relative to alternative (non-fuzzy) methods. The fuzzy Bayesian inference framework provides a flexible methodology that fits the imprecise nature of linguistic information on historical floods as available in historical written documentation.

  19. Vistula River bed erosion processes and their influence on Warsaw’s flood safety

    Directory of Open Access Journals (Sweden)

    A. Magnuszewski

    2015-03-01

    Full Text Available Large cities have historically been well protected against floods as a function of their importance to society. In Warsaw, Poland, located on a narrow passage of the Vistula River valley, urban flood disasters were not unusual. Beginning at the end of the 19th century, the construction of river embankment and training works caused the narrowing of the flood passage path in the downtown reach of the river. The process of bed erosion lowered the elevation of the river bed by 205 cm over the 20th century, and the consequences of bed lowering are reflected by the rating curve change. Conditions of the flood passage have been analysed by the CCHE2D hydrodynamic model both in retro-modelling and scenario simulation modelling. The high water mark of the 1844 flood and iterative calculations in retro-modelling made possible estimation of the discharge, Q = 8250 m3 s−1. This highest observed historical flood in a natural river has been compared to recent conditions of the Vistula River in Warsaw by scenario modelling. The result shows dramatic changes in water surface elevation, velocities, and shear stress. The vertical velocity in the proximity of Port Praski gauge at km 513 can reach 3.5 m s−1, a very high value for a lowland river. The average flow conveyance is improving due to channel erosion but also declining in the case of extreme floods due to high resistance from vegetation on the flood plains.

  20. Geotechinical properties of Ariake clay in Saga plain - Japan

    Energy Technology Data Exchange (ETDEWEB)

    Khamehchiyan, M.; Iwao, Y. [Saga Univ., Saga (Japan)

    1994-12-21

    Saga plain, a lowland of less than 5 meters above mean sea level with an area of about 400 square kilometers, lies in north of Ariake Sea (western area of Chikugo river) in Kyushu, Japan. The tidal range of the Ariake Sea is about 6 meters with a mean high water level of 2.89 meters. Therefore, several dikes are constructed to prevent flooding during heavy rainfalls. The thickness of the soft Ariake clay is generally about 10 to 20 meters with a maximum value of 30 meters. It is attempted to discuss the geotechnical properties of Ariake clay up to the depth of 20 meters by using the data of 110 exploratory boreholes drilled in different places of Saga plain. Simple regression analysis is adopted between physical properties such as void ratio, e, natural water content, total unite weight, and consistency limits. Various regression models are developed to estimate unconfined compressive strength, compression index C{sub r}, compression ratio, which is equal to C{sub c}/(1+e) and preconsolidation pressure, from more easily determinable soil index properties. 14 refs., 12 figs., 4 tabs.

  1. Assessing Flood Risk Using Reservoir Flood Control Rules

    Institute of Scientific and Technical Information of China (English)

    Xiang Fu; Yadong Mei; Zhihuai Xiao

    2016-01-01

    The application of conventional flood operation regulation is restricted due to insufficient description of flood control rules for the Pubugou Reservoir in southern China. Based on the require-ments of different flood control objects, this paper proposes to optimize flood control rules with punish-ment mechanism by defining different parameters of flood control rules in response to flood inflow fore-cast and reservoir water level. A genetic algorithm is adopted for solving parameter optimization problem. The failure risk and overflow volume of the downstream insufficient flood control capacity are assessed through the reservoir operation policies. The results show that an optimised regulation can provide better performance than the current flood control rules.

  2. MODIS-based multi-parametric platform for mapping of flood affected areas. Case study: 2006 Danube extreme flood in Romania

    Directory of Open Access Journals (Sweden)

    Craciunescu Vasile

    2016-12-01

    Full Text Available Flooding remains the most widely distributed natural hazard in Europe, leading to significant economic and social impact. Earth observation data is presently capable of making fundamental contributions towards reducing the detrimental effects of extreme floods. Technological advance makes development of online services able to process high volumes of satellite data without the need of dedicated desktop software licenses possible. The main objective of the case study is to present and evaluate a methodology for mapping of flooded areas based on MODIS satellite images derived indices and using state-of-the-art geospatial web services. The methodology and the developed platform were tested with data for the historical flood event that affected the Danube floodplain in 2006 in Romania. The results proved that, despite the relative coarse resolution, MODIS data is very useful for mapping the development flooded area in large plain floods. Moreover it was shown, that the possibility to adapt and combine the existing global algorithms for flood detection to fit the local conditions is extremely important to obtain accurate results.

  3. Dating fluvial archives of the Riverine Plain, Southeastern Australia

    Science.gov (United States)

    Mueller, Daniela; Cohen, Tim; Reinfelds, Ivars; Jacobs, Zenobia; Shulmeister, James

    2016-04-01

    The Riverine Plain of Southeastern Australia is characterized by a multiplicity of relict river channels. Compared to the modern drainage system the most prominent of those distinct features are defined by large bankfull channel widths, large meander wavelengths and coarse sediment loads. Such morphological differences provide evidence for regimes of higher discharge, stemming from significant changes in runoff volumes, flood-frequency regimes and sediment supply. An existing geochronology for some of these channels is based on multi-grain thermoluminescence (Murrumbidgee River; Page et al., 1996) or radio-carbon dating (Goulburn River; Bowler, 1978) and indicates enhanced fluvial activity between 30 to 13 ka. The absence of exact Last Glacial Maximum (LGM, 21 ± 3 ka) ages of the Murrumbidgee palaeochannels was interpreted to indicate decreased fluvial activity during the peak of the LGM but was not inferred for the nearby Goulburn River. Recent developments in optical dating, especially measurements of individual grains of quartz, allow for an examination of these previous findings. Key sites along the Murrumbidgee and Goulburn Rivers have been revisited and new sites of the adjacent Murray River have been investigated. A revised, high-resolution geochronology based on single-grain optically stimulated luminescence dating is used to examine the precise occurrence of those massive channels and their implications for the Southern Hemisphere LGM. References: Page, K., Nanson, G., Price, D. (1996). Chronology of Murrumbidgee River palaeochannels on the Riverine Plain, southeastern Australia. Journal of Quaternary Science 11(4): 311-326. Bowler, J. (1978). Quaternary Climate and Tectonics in the Evolution of the Riverine Plain, Southeastern Australia. In: Davies, J. & Williams, M. (Editors). Landform Evolution in Australia, Australian National University Press: Canberra. p. 70-112.

  4. Stratigraphy and depositional environments of the upper Pleistocene Chemehuevi Formation along the lower Colorado River

    Science.gov (United States)

    Malmon, Daniel V.; Howard, Keith A.; House, P. Kyle; Lundstrom, Scott C.; Pearthree, Philip A.; Sarna-Wojcicki, Andrei M.; Wan, Elmira; Wahl, David B.

    2011-01-01

    The Chemehuevi Formation forms a conspicuous, widespread, and correlative set of nonmarine sediments lining the valleys of the Colorado River and several of its larger tributaries in the Basin and Range geologic province. These sediments have been examined by geologists since J. S. Newberry visited the region in 1857 and are widely cited in the geologic literature; however their origin remains unresolved and their stratigraphic context has been confused by inconsistent nomenclature and by conflicting interpretations of their origin. This is one of the most prominent stratigraphic units along the river below the Grand Canyon, and the formation records an important event or set of events in the history of the Colorado River. Here we summarize what is known about these deposits throughout their range, present new stratigraphic, sedimentologic, topographic, and tephrochronologic data, and formally define them as a lithostratigraphic unit. The Chemehuevi Formation consists primarily of a bluff-forming mud facies, consisting of gypsum-bearing, horizontally bedded sand, silt, and clay, and a slope-forming sand facies containing poorly bedded, well sorted, quartz rich sand and scattered gravel. The sedimentary characteristics and fossil assemblages of the two facies types suggest that they were deposited in flood plain and channel environments, respectively. In addition to these two primary facies, we identify three other mappable facies in the formation: a thick-bedded rhythmite facies, now drowned by Lake Mead; a valley-margin facies containing abundant locally derived sediment; and several tributary facies consisting of mixed fluvial and lacustrine deposits in the lower parts of major tributary valleys. Observations from the subsurface and at outcrops near the elevation of the modern flood plain suggest that the formation also contains a regional basal gravel member. Surveys of numerous outcrops using high-precision GPS demonstrate that although the sand facies commonly

  5. The environmental footprint of the 2011 Tohoku-oki tsunami on the Sendai Plain

    Science.gov (United States)

    Chague-Goff, C.; Wong, H.; Niedzielski, P.; Szczucinski, W.; Goff, J. R.; Sugawara, D.; Nishimura, Y.

    2012-12-01

    The 11 March 2011 Tohoku-oki tsunami resulted in nearly 19,000 dead or missing and caused extensive damage to buildings and many types of infrastructure. It inundated large areas of farmland on the Sendai Plain, leaving behind an extensive sandy to muddy deposit coating paddy rice fields. Two months after the tsunami, many areas were still inundated on the low-lying plain. Salt crusts were also observed in many places, where saltwater had evaporated. Field surveys were carried out in May, August, October 2011 and February 2012 along a 5 km transect north of Sendai airport, to assess the environmental impact of the tsunami on farmland and its temporal extent, with particular emphasis on contamination by salts, but also metals and metalloids. Evaporation led to elevated conductivity in ponded water, canals and channels in May 2011 (from brackish to saline), and while rainfall resulted in dilution, brackish water was still recorded in August and October 2011, and even in a few areas in February 2012. Our study revealed that not only the sediment deposited by the tsunami (sand-dominated up to 2.9 km inland, and mud-dominated up to 4.65 km inland) but also the underlying soil was contaminated by saltwater. Concentrations of up to 10.5% Cl, 6.6% Na, 2.8% SO4 and 440 mg kg-1 Br were recorded in May 2011 in surface sediment where seawater had ponded for a long time, as shown by extensive salt crust residues. The underlying rice paddy soil was also contaminated by saltwater, down to 15 cm depth, as revealed by high levels of water-leachable ions and cations. While ion concentrations had decreased by August 2011, they were still notable. Preliminary results also show that the tsunami deposit and the underlying soil were still contaminated by salt in February 2012, indicating the long-term impact of tsunami inundation on farming. In addition, much of this salt is likely to contribute to salinisation of shallow groundwater, further impeding rice farming. Indeed, rice

  6. Geo-archaeological aspects of the Modena plain (Northern Italy

    Directory of Open Access Journals (Sweden)

    Doriano Castaldini

    2007-12-01

    Full Text Available This paper traces the various stages of geomorphological evolution of the plain area around Modena from the VIth millennium B.C.E. (Neolithic to the Present, through a reconstruction of the ancient landscape and human settlements.By means of a GIS platform, geomorphological investigations led to the implementation of a Microrelief Map, a Digital Elevation Model (DEM, a Map of Surface Deposits and a Geomorphological Map.The most striking altimetric features in the study area are the morphological changes of the Rivers Secchia and Panaro: south of Modena they run deep in the alluvial plain whereas north of the town they flow elevated over the plain. The surface lithology consists mainly of silt, with bands of sand and clay; mainly gravel deposits crop out only near southern tracks of the main Apennine watercourses. The geomorphological landscape is mainly characterised by alluvial fans, fluvial ridges paleo-riverbeds fluvial scarps, natural springs and some depressed areas; worth of note are also forms connected with human activity.There have been several attempts to cross–date geological and geomorphological evidence with archaeological data, on both detailed and wide territorial scales. A further advancement can now be attempted by comparing data obtained from systematic research on fluvial forms with data contained in the archives.In the area studied, some 800 archaeological sites were identified and catalogued. Such a high number of archaeological sites can give a great deal more information than is found in any other place in northern Italy.The research took into account the overlapping of archaeological and geomorphological data, with the implementation into a GIS (ArcGis 8.3 of geoarchaeological maps divided in main periods and here represented from the Neolithic to the to Iron Age and from Roman period to the Early Middle Ages. The dating thus obtained for fluvial forms was mainly based on the relationship between these forms and

  7. Natural Flood Management in context: evaluating and enhancing the impact.

    Science.gov (United States)

    Metcalfe, Peter; Beven, Keith; Hankin, Barry; Lamb, Rob

    2016-04-01

    The series of flood events in the UK throughout December 2015 have led to calls for a reappraisal of the country's approach to flood management. In parts of Cumbria so-called "1 in 100" year floods have occurred three times in the last ten years, leading to significant infrastructure damage. Hard-engineered defences upgraded to cope with an anticipated 20% increase in peak flows and these 1% AEP events have been overwhelmed. It has become more widely acknowledged that unsympathetic agricultural and upland management practices, mainly since the Second World War, have led to a significant loss of storage in mid and upper catchments and their consequent ability to retain and slow storm run-off. Natural Flood Management (NFM) is a nature-based solution to restoring this storage and flood peak attenuation through a network of small-scale features exploiting natural topography and materials. Combined with other "soft" interventions such as restoring flood plain roughness and tree-planting, NFM offers the attractive prospect of an intervention that can target both the ecological and chemical objectives of the Water Framework Directive and the resilience demanded by the Floods Directive. We developed a simple computerised physical routing model that can account for the presence of in-channel and offline features such as would be found in a NFM scheme. These will add storage to the channel and floodplain and throttle the downstream discharge at storm flows. The model was applied to the heavily-modified channel network of an agricultural catchment in North Yorkshire using the run-off simulated for two storm events that caused flooding downstream in the autumn of 2012. Using up to 60 online features we demonstrated some gains in channel storage and a small impact on the flood hydrograph which would, however, have been insufficient to prevent the downstream floods in either of the storms. Complementary research at JBA has applied their hydrodynamic model JFLOW+ to identify

  8. Composite Flood Risk for New Jersery

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Composite Flood Risk layer combines flood hazard datasets from Federal Emergency Management Agency (FEMA) flood zones, NOAA's Shallow Coastal Flooding, and the...

  9. Composite Flood Risk for Virgin Island

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Composite Flood Risk layer combines flood hazard datasets from Federal Emergency Management Agency (FEMA) flood zones, NOAA's Shallow Coastal Flooding, and the...

  10. Assessment of floodplain vulnerability during extreme Mississippi River flood 2011

    Science.gov (United States)

    Goodwell, Allison E.; Zhu, Zhenduo; Dutta, Debsunder; Greenberg, Jonathan A.; Kumar, Praveen; Garcia, Marcelo H.; Rhoads, Bruce L.; Holmes, Jr., Robert R.; Parker, Gary; Berretta, David P.; Jacobson, Robert B.

    2014-01-01

    Regional change in the variability and magnitude of flooding could be a major consequence of future global climate change. Extreme floods have the capacity to rapidly transform landscapes and expose landscape vulnerabilities through highly variable spatial patterns of inundation, erosion, and deposition. We use the historic activation of the Birds Point-New Madrid Floodway during the Mississippi and Ohio River Flooding of 2011 as a scientifically unique stress experiment to analyze indicators of floodplain vulnerability. We use pre- and postflood airborne Light Detection and Ranging data sets to locate erosional and depositional hotspots over the 540 km2 agricultural Floodway. While riparian vegetation between the river and the main levee breach likely prevented widespread deposition, localized scour and deposition occurred near the levee breaches. Eroded gullies nearly 1 km in length were observed at a low ridge of a relict meander scar of the Mississippi River. Our flow modeling and spatial mapping analysis attributes this vulnerability to a combination of erodible soils, flow acceleration associated with legacy fluvial landforms, and a lack of woody vegetation to anchor soil and enhance flow resistance. Results from this study could guide future mitigation and adaptation measures in cases of extreme flooding.

  11. Assessment of floodplain vulnerability during extreme Mississippi River flood 2011.

    Science.gov (United States)

    Goodwell, Allison E; Zhu, Zhenduo; Dutta, Debsunder; Greenberg, Jonathan A; Kumar, Praveen; Garcia, Marcelo H; Rhoads, Bruce L; Holmes, Robert R; Parker, Gary; Berretta, David P; Jacobson, Robert B

    2014-01-01

    Regional change in the variability and magnitude of flooding could be a major consequence of future global climate change. Extreme floods have the capacity to rapidly transform landscapes and expose landscape vulnerabilities through highly variable spatial patterns of inundation, erosion, and deposition. We use the historic activation of the Birds Point-New Madrid Floodway during the Mississippi and Ohio River Flooding of 2011 as a scientifically unique stress experiment to analyze indicators of floodplain vulnerability. We use pre- and postflood airborne Light Detection and Ranging data sets to locate erosional and depositional hotspots over the 540 km(2) agricultural Floodway. While riparian vegetation between the river and the main levee breach likely prevented widespread deposition, localized scour and deposition occurred near the levee breaches. Eroded gullies nearly 1 km in length were observed at a low ridge of a relict meander scar of the Mississippi River. Our flow modeling and spatial mapping analysis attributes this vulnerability to a combination of erodible soils, flow acceleration associated with legacy fluvial landforms, and a lack of woody vegetation to anchor soil and enhance flow resistance. Results from this study could guide future mitigation and adaptation measures in cases of extreme flooding.

  12. Flood Risk Management In Europe: European flood regulation

    NARCIS (Netherlands)

    Hegger, D.L.T.; Bakker, M.H.; Green, C.; Driessen, Peter; Delvaux, B.; Rijswick, H.F.M.W. van; Suykens, C.; Beyers, J-C.; Deketelaere, K.; Doorn-Hoekveld, W. van; Dieperink, C.

    2013-01-01

    In Europe, water management is moving from flood defense to a risk management approach, which takes both the probability and the potential consequences of flooding into account. In this report, we will look at Directives and (non-)EU- initiatives in place to deal with flood risk in Europe indirectly

  13. Improving Global Flood Forecasting using Satellite Detected Flood Extent

    NARCIS (Netherlands)

    Revilla Romero, B.

    2016-01-01

    Flooding is a natural global phenomenon but in many cases is exacerbated by human activity. Although flooding generally affects humans in a negative way, bringing death, suffering, and economic impacts, it also has potentially beneficial effects. Early flood warning and forecasting systems, as well

  14. Improving Global Flood Forecasting using Satellite Detected Flood Extent

    NARCIS (Netherlands)

    Revilla Romero, B.

    2016-01-01

    Flooding is a natural global phenomenon but in many cases is exacerbated by human activity. Although flooding generally affects humans in a negative way, bringing death, suffering, and economic impacts, it also has potentially beneficial effects. Early flood warning and forecasting systems, as well

  15. PROVISION OF DIKE SLOPE STABILITY FOR TERRITORY PROTECTION AGAINST GORYN RIVER FLOODS

    Directory of Open Access Journals (Sweden)

    E. Michnevich

    2013-01-01

    Full Text Available Hydrologic conditions that cause the Goryn river floods have been described in the paper. The paper considers engineering solutions pertaining to prevention of catastrophic floodings by bifurcation of maximum river flow while constructing a watershed dike and creating a non-flood polder in the flood plain. The formulas have been developed for calculation of dike slope fixing by dumped riprap when the slopes are subjected to stream impact. The paper provides an analysis of existing dependences for calculation of riprap material size in order to protect slopes against waves. The possible ways for lower cost of fixation while using  waste tyres and also while constructing  small wave-suppressing dikes reinforced by dumped riprap and shrub vegetation along the main dike have been revealed in the paper.

  16. The Global Flood Model

    Science.gov (United States)

    Williams, P.; Huddelston, M.; Michel, G.; Thompson, S.; Heynert, K.; Pickering, C.; Abbott Donnelly, I.; Fewtrell, T.; Galy, H.; Sperna Weiland, F.; Winsemius, H.; Weerts, A.; Nixon, S.; Davies, P.; Schiferli, D.

    2012-04-01

    Recently, a Global Flood Model (GFM) initiative has been proposed by Willis, UK Met Office, Esri, Deltares and IBM. The idea is to create a global community platform that enables better understanding of the complexities of flood risk assessment to better support the decisions, education and communication needed to mitigate flood risk. The GFM will provide tools for assessing the risk of floods, for devising mitigation strategies such as land-use changes and infrastructure improvements, and for enabling effective pre- and post-flood event response. The GFM combines humanitarian and commercial motives. It will benefit: - The public, seeking to preserve personal safety and property; - State and local governments, seeking to safeguard economic activity, and improve resilience; - NGOs, similarly seeking to respond proactively to flood events; - The insurance sector, seeking to understand and price flood risk; - Large corporations, seeking to protect global operations and supply chains. The GFM is an integrated and transparent set of modules, each composed of models and data. For each module, there are two core elements: a live "reference version" (a worked example) and a framework of specifications, which will allow development of alternative versions. In the future, users will be able to work with the reference version or substitute their own models and data. If these meet the specification for the relevant module, they will interoperate with the rest of the GFM. Some "crowd-sourced" modules could even be accredited and published to the wider GFM community. Our intent is to build on existing public, private and academic work, improve local adoption, and stimulate the development of multiple - but compatible - alternatives, so strengthening mankind's ability to manage flood impacts. The GFM is being developed and managed by a non-profit organization created for the purpose. The business model will be inspired from open source software (eg Linux): - for non-profit usage

  17. FEMA DFIRM Flood Hazard Areas

    Data.gov (United States)

    Minnesota Department of Natural Resources — FEMA flood hazard delineations are used by the Federal Emergency Management Agency (FEMA) to designate the Special Flood Hazard Area (SFHA) and for insurance rating...

  18. FEMA DFIRM Base Flood Elevations

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Base Flood Elevation (BFE) table is required for any digital data where BFE lines will be shown on the corresponding Flood Insurance Rate Map (FIRM). Normally,...

  19. 2013 FEMA 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...

  20. FLOOD CHARACTERISTICS AND MANAGEMENT ADAPTATIONS ...

    African Journals Online (AJOL)

    Dr Osondu

    2011-10-26

    , bearing flood losses and land ... Engineering control of the major tributaries of the Imo River system is required to ..... on previous knowledge of physical nature of flood ... uptake; other factors include a lack of formal titles to.

  1. 2013 FEMA 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...

  2. Base Flood Elevation (BFE) Lines

    Data.gov (United States)

    Department of Homeland Security — The Base Flood Elevation (BFE) table is required for any digital data where BFE lines will be shown on the corresponding Flood Insurance Rate Map (FIRM). Normally if...

  3. National Flood Hazard Layer (NFHL)

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The National Flood Hazard Layer (NFHL) is a compilation of GIS data that comprises a nationwide digital Flood Insurance Rate Map. The GIS data and services are...

  4. FEMA Q3 Flood Data

    Data.gov (United States)

    Kansas Data Access and Support Center — The Q3 Flood Data are derived from the Flood Insurance Rate Maps (FIRMS) published by the Federal Emergency Management Agency (FEMA). The file is georeferenced to...

  5. FEMA 100 year Flood Data

    Data.gov (United States)

    California Department of Resources — The Q3 Flood Data product is a digital representation of certain features of FEMA's Flood Insurance Rate Map (FIRM) product, intended for use with desktop mapping...

  6. 2013 FEMA 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...

  7. [Effect of flooding disturbance on aboveground biomass of Leymus chinensis grassland--a preliminary study].

    Science.gov (United States)

    Wang, Zhengwen; Zhu, Tingcheng

    2003-12-01

    To investigate the effect of flooding disturbance on the net primary productivity of Songnen steppe, a comparatively thorough study was conducted on Sanjiadian State-owned Rangeland in Da'an city, Jilin Province, which was partly flooded in 1998. The study site was located in the south Songnen plain of Northeastern China, dominated by Leymus chinensis grassland. An extensively mild slope with flooding gradients (from un-flooded to heavily flooded) was taken as the study site. Two flooded transects coded FL and FH which was respectively subjected to 3 and 9 months of flooding were designed, and an un-flooded one coded CK at a relatively higher elevation was set as a control. Before flooding occurred in 1998, the slope had an almost uniform soil and L. chinensis dominated vegetation. Each transect was 0.2 hm2 (100 m x 20 m) in size, and the two flooded transects were almost paralleled each other, with the longer sides of them perpendicular to the retrieving direction of floodwater. In each transect twenty 1 m2 sized quadrats were randomly chosen to survey the community structure and the aboveground biomass. Comparative analyses were made on the dynamics of soil water, soil N and P, and species composition of grassland communities that occurred in responses to flooding disturbance. The results showed that the lightly and heavily flooded transects had a significantly larger aboveground biomass than the control, with the increase of 89.54% and 113.45%, respectively. The heavily flooded transect had a slightly but insignificantly larger aboveground biomass than the lightly flooded one, indicating that on flooded sites, water was not the limiting factor of the aboveground biomass. The acute changes of soil water caused by flooding led to the changes of soil nutrients and species assemblages, which would impact community biomass. Just as the case for aboveground biomass, the soil water contents of the two flooded transects were significantly larger than that of control

  8. Understanding Extreme Spanish Coastal Flood Events

    Science.gov (United States)

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

    2013-04-01

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

  9. Long-lasting floods buffer the thermal regime of the Pampas

    Science.gov (United States)

    Houspanossian, Javier; Kuppel, Sylvain; Nosetto, Marcelo; Di Bella, Carlos; Oricchio, Patricio; Barrucand, Mariana; Rusticucci, Matilde; Jobbágy, Esteban

    2016-10-01

    The presence of large water masses influences the thermal regime of nearby land shaping the local climate of coastal areas by the ocean or large continental lakes. Large surface water bodies have an ephemeral nature in the vast sedimentary plains of the Pampas (Argentina) where non-flooded periods alternate with flooding cycles covering up to one third of the landscape for several months. Based on temperature records from 17 sites located 1 to 700 km away from the Atlantic coast and MODIS land surface temperature data, we explore the effects of floods on diurnal and seasonal thermal ranges as well as temperature extremes. In non-flooded periods, there is a linear increase of mean diurnal thermal range (DTR) from the coast towards the interior of the region (DTR increasing from 10 to 16 K, 0.79 K/100 km, r 2 = 0.81). This relationship weakens during flood episodes when the DTR of flood-prone inland locations shows a decline of 2 to 4 K, depending on surface water coverage in the surrounding area. DTR even approaches typical coastal values 500 km away from the ocean in the most flooded location that we studied during the three flooding cycles recorded in the study period. Frosts-free periods, a key driver of the phenology of both natural and cultivated ecosystems, are extended by up to 55 days during floods, most likely as a result of enhanced ground heat storage across the landscape ( 2.7 fold change in day-night heat transfer) combined with other effects on the surface energy balance such as greater night evaporation rates. The reduced thermal range and longer frost-free periods affect plant growth development and may offer an opportunity for longer crop growing periods, which may not only contribute to partially compensating for regional production losses caused by floods, but also open avenues for flood mitigation through higher plant evapotranspirative water losses.

  10. Multi-scale model analysis and hindcast of the 2013 Colorado Flood

    Science.gov (United States)

    Gochis, David; Yu, Wei; Sampson, Kevin; Dugger, Aubrey; McCreight, James; Zhang, Yongxin; Ikeda, Kyoko

    2015-04-01

    While the generation of most flood and flash flood events is fundamentally linked to the occurrence of heavy rainfall, the physical mechanisms responsible for translating rainfall into floods are complex and manifold. These runoff generation processes evolve over many spatial and temporal scales during the course of flooding events. As such robust flood and flash flood prediction systems need to account for multitude of terrestrial processes occurring over a wide range of space and time scales. One such extreme multiscale flood event was the 2013 Colorado Flood in which over 400 mm of rainfall fell along the Rock Mountain mountain front region over the course of a few days. The flooding impacts from this heavy rainfall event included not only high, fast flows in steep mountain streams but also included large areas of inundation on the adjacent plains and numerous soil saturation excess impacts such as hillslope failures and groundwater intrusions into domestic structures. A multi-scale and multi-process evaluation of this flood event is performed using the community WRF-Hydro modeling system. We incorporate several operational quantitative precipitation estimate and quantitative precipitation forecast products in the analysis and document the skill of multiple configurations of WRF-Hydro physics options across a range of contributing area length scales. Emphasis is placed on assessing how well the different model configurations capture the multi-scale streamflow response from small headwater catchments out to the entire South Platte River basin whose total contributing area exceeds 25,000 sq km. In addition to streamflow we also present evaluations of event simulations and hindcasts of soil saturation fraction, groundwater levels and inundated areas as a means of assessing different runoff generation mechanisms. Finally, results from a U.S. national-scale, fully-coupled hydrometeorological hindcast of the 2013 Colorado flood event using the combined WRF atmospheric

  11. Multivariate pluvial flood damage models

    Energy Technology Data Exchange (ETDEWEB)

    Van Ootegem, Luc [HIVA — University of Louvain (Belgium); SHERPPA — Ghent University (Belgium); Verhofstadt, Elsy [SHERPPA — Ghent University (Belgium); Van Herck, Kristine; Creten, Tom [HIVA — University of Louvain (Belgium)

    2015-09-15

    Depth–damage-functions, relating the monetary flood damage to the depth of the inundation, are commonly used in the case of fluvial floods (floods caused by a river overflowing). We construct four multivariate damage models for pluvial floods (caused by extreme rainfall) by differentiating on the one hand between ground floor floods and basement floods and on the other hand between damage to residential buildings and damage to housing contents. We do not only take into account the effect of flood-depth on damage, but also incorporate the effects of non-hazard indicators (building characteristics, behavioural indicators and socio-economic variables). By using a Tobit-estimation technique on identified victims of pluvial floods in Flanders (Belgium), we take into account the effect of cases of reported zero damage. Our results show that the flood depth is an important predictor of damage, but with a diverging impact between ground floor floods and basement floods. Also non-hazard indicators are important. For example being aware of the risk just before the water enters the building reduces content damage considerably, underlining the importance of warning systems and policy in this case of pluvial floods. - Highlights: • Prediction of damage of pluvial floods using also non-hazard information • We include ‘no damage cases’ using a Tobit model. • The damage of flood depth is stronger for ground floor than for basement floods. • Non-hazard indicators are especially important for content damage. • Potential gain of policies that increase awareness of flood risks.

  12. Optimal strategies for flood prevention

    NARCIS (Netherlands)

    Eijgenraam, Carel; Brekelmans, Ruud; den Hertog, Dick; Roos, C.

    2016-01-01

    Flood prevention policy is of major importance to the Netherlands since a large part of the country is below sea level and high water levels in rivers may also cause floods. In this paper we propose a dike height optimization model to determine economically efficient flood protection standards. We i

  13. Floods in a changing climate

    Science.gov (United States)

    Theresa K. Andersen; Marshall J. Shepherd

    2013-01-01

    Atmospheric warming and associated hydrological changes have implications for regional flood intensity and frequency. Climate models and hydrological models have the ability to integrate various contributing factors and assess potential changes to hydrology at global to local scales through the century. This survey of floods in a changing climate reviews flood...

  14. Character of Terrestrial Sequence Stratigraphy and Depositional System in Incised Valley, Outcrop Area of Karamay Oilfield, Junggar Basin, China

    Institute of Scientific and Technical Information of China (English)

    Jiao Yangquan; Yan Jiaxin; Li Sitian; Yang Ruiqi; Lang Fengjiang; Yang Shengke

    2004-01-01

    In the Karamay oilfield located on the northwestern margin of Junggar basin, Xinjiang, China, a large area of the Karamay Formation is exposed at outcrop in the northeast of the oilfield, a consequence of thrusting. The Middle Triassic Karamay Formation in the outcrop area is a type of terrestrial third-order sequence, bounded by two easily recognizable sequence boundaries: a regional surface of angular unconformity (SB1) at the base and a regional unconformity (SB2) at the top. Within the Karamay Formation, two lacustrine expansion events can be recognized and be used to identify both the initial and the maximum lacustrine flooding surfaces. The two lacustrine flooding surfaces serve as references for the classification of this third-order sequence-Karamay Formation into the following three sedimentary successions: a lower lowstand systems tract (LST), a middle lacustrine-expanding systems tract (EST), and an upper highstand systems tract (HST). Different systems tracts are composed of different depositional system assemblages. In this paper, each depositional system is described in detail. The lowstand systems tract in the study area is characterized by incised valleys. At the base and on the margin of the incised valleys occur alluvial fan depositional systems, and in the upper and distal parts of the alluvial fan, low-sinuosity river depositional systems. The lacustrine-expanding systems tract consists of a lacustrine depositional system and a lacustrine delta depositional system, overlying the lower incised valley fills. The highstand systems tract is filled by a widespread lacustrine braided delta depositional system. The analysis of sequence stratigraphy in this paper serves the description of the spatial distribution of the reservoir. The depositional system analysis serves the description of the reservoir types. Field investigations of oil sandstone and oil seepage show that the Karamay Formation is composed of several types of reservoirs. However, two

  15. Erosion and sedimentation during the September 2015 flooding of the Kinu River, central Japan

    Science.gov (United States)

    Dan Matsumoto; Sawai, Yuki; Yamada, Masaki; Namegaya, Yuichi; Shinozaki, Tetsuya; Takeda, Daisuke; Fujino, Shigehiro; Tanigawa, Koichiro; Nakamura, Atsunori; Pilarczyk, Jessica E.

    2016-01-01

    Erosional and sedimentary features associated with flooding have been documented in both modern and past cases. However, only a few studies have demonstrated the relationship between these features and the corresponding hydraulic conditions that produced them, making it difficult to evaluate the magnitude of paleo-flooding. This study describes the characteristics associated with inundation depth and flow direction, as well as the erosional and sedimentary features resulting from the disastrous flooding of the Kinu River, central Japan, in September 2015. Water levels rose rapidly due to heavy rainfall that eventually overtopped, and subsequently breached, a levee in Joso City, causing destructive flooding on the surrounding floodplain. Distinctive erosional features are found next to the breached levee, while depositional features, such as a sandy crevasse-splay deposit are found further away from the breach. The deposit can be divided into three units based on sedimentary facies. The vertical and lateral changes of these sedimentary facies may be the result of temporal and spatial changes associated with flow during the single flooding event. These observations and quantitative data provide information that can be used to reveal the paleohydrology of flood deposits in the stratigraphic record, leading to improved mitigation of future flooding disasters. PMID:27677769

  16. IMPACT ON HEALTH CARE DELIVERY SYSTEM DUE TO THE WORST FLOOD OF THE CENTURY IN KASHMIR, INDIA: AN OBSERVATIONAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Kouser

    2014-12-01

    Full Text Available INTRODUCTION: Flood is the most common natural disaster in the world both in the developed and developing nations. This year one of the greatest floods, worst in over a decade hit the nation in Jammu and Kashmir on 7th September 2014, due to continuous downpour for about 4 days. Study design: Observational. RESULTS: SKIMS Medical College and Hospital, Bemina was inundated first followed by the oldest tertiary care SMHS hospital. Health care was affected at all the three levels viz. primary, secondary and tertiary the total losses to the health care was estimated to be 200 million. CONCLUSION: More than 1.5 million of the population was affected. People were rendered homeless. Unlike flash flood the present flood in Kashmir was a plain flood which occurs due to extensive rainfall lasting several days.

  17. Spectral gamma-ray signature of fluvial deposits: a case study from the Late Permian Rio do Rasto Formation, Parana Basin, Brazil; Assinatura gamaespectrometrica de depositos fluviais: estudo de caso na Formacao do Rio do Rasto, Permiano Superior da Bacia do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Sowek, Guilherme Arruda, E-mail: arruda@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Programa de Pos-graduacao em Geologia; Ferreira, Francisco Jose Fonseca; Vesely, Fernando Farias, E-mail: francisco.ferreira@ufpr.br, E-mail: vesely@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Setor de Ciencias da Terra; Berton, Fabio, E-mail: fabioberton1@yahoo.com.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil)

    2013-09-15

    Fluvial channel-fill deposits form highly heterogeneous hydrocarbon reservoirs. The study of outcrop analogs can help in the characterization of these heterogeneities, which are usually not detected by subsurface geophysical methods. The aim of this research is to compare outcrop log signatures with grain size trends and depositional elements of the fluvial deposits of the Late Permian Rio do Rasto Formation. A series of vertical gamma-ray logs were assembled in two outcrops in order to: 1) characterize log-facies in a succession composed of alternated flood plain, channel fill and eolian strata; 2) define within-channel spectral gamma-ray variability of a mixed-load composite point bar deposit and its relationship with grain size trends and lithofacies; 3) correlate log signatures observed in the outcrop sections with deep exploratory wells drilled several tens of kilometers from the study area. The results of this study show that gamma-ray logs have good correlation with grain size trends and that different depositional elements have distinct signatures. On the other hand, point bar deposits exhibit strong lateral changes in log signature due variations in grain size and mud content within lateral accretion strata. Although frequent, the classic bell-shaped log motif was not always detected, which means that the amount of fluvial channel-fill deposits recognized in subsurface can be underestimated. Similar log signatures were detected in the boreholes, at least in the closest ones, helping in paleoenvironmental interpretation in the subsurface. (author)

  18. Towards a 1km resolution global flood risk model

    Science.gov (United States)

    Bates, Paul; Neal, Jeff; Sampson, Chris; Smith, Andy

    2014-05-01

    Recent advances in computationally efficient numerical algorithms and new High Performance Computing architectures now make high (1-2km) resolution global hydrodynamic models a realistic proposition. However in many areas of the world the data sets and tools necessary to undertake such modelling do not currently exist. In particular, five major problems need to be resolved: (1) the best globally available terrain data (SRTM) was generated from X-band interferometric radar data which does not penetrate vegetation canopies and which has significant problems in determining ground elevations in urban areas; (2) a global river bathymetry data set does not currently exist; (3) most river channels globally are less than the smallest currently resolvable grid scale (1km) and therefore require a sub-grid treatment; (4) a means to estimate the magnitude of the T year flood at any point along the global river network does not currently exist; and (5) a large proportion of flood losses are generated by off-floodplain surface water flows which are not well represented in current hydrodynamic modelling systems. In this paper we propose solutions to each of these five issues as part of a concerted effort to develop a 1km (or better) resolution global flood hazard model. We describe the new numerical algorithms, computer architectures and computational resources used, and demonstrate solutions to the five previously intractable problems identified above. We conduct a validation study of the modelling against satellite imagery of major flooding on the Mississippi-Missouri confluence plain in the central USA before outlining a proof-of-concept regional study for SE Asia as a step towards a global scale model. For SE Asia we simulate flood hazard for ten different flood return periods over the entire Thailand, Cambodia, Vietnam, Malaysia and Laos region at 1km resolution and show that the modelling produces coherent, consistent and sensible simulations of extent and water depth.

  19. Rethinking the relationship between flood risk perception and flood management.

    Science.gov (United States)

    Birkholz, S; Muro, M; Jeffrey, P; Smith, H M

    2014-04-15

    Although flood risk perceptions and their concomitant motivations for behaviour have long been recognised as significant features of community resilience in the face of flooding events, there has, for some time now, been a poorly appreciated fissure in the accompanying literature. Specifically, rationalist and constructivist paradigms in the broader domain of risk perception provide different (though not always conflicting) contexts for interpreting evidence and developing theory. This contribution reviews the major constructs that have been applied to understanding flood risk perceptions and contextualises these within broader conceptual developments around risk perception theory and contemporary thinking around flood risk management. We argue that there is a need to re-examine and re-invigorate flood risk perception research, in a manner that is comprehensively underpinned by more constructivist thinking around flood risk management as well as by developments in broader risk perception research. We draw attention to an historical over-emphasis on the cognitive perceptions of those at risk to the detriment of a richer understanding of a wider range of flood risk perceptions such as those of policy-makers or of tax-payers who live outside flood affected areas as well as the linkages between these perspectives and protective measures such as state-supported flood insurance schemes. Conclusions challenge existing understandings of the relationship between risk perception and flood management, particularly where the latter relates to communication strategies and the extent to which those at risk from flooding feel responsible for taking protective actions.

  20. Flooding on Elbe River

    Science.gov (United States)

    2002-01-01

    Heavy rains in Central Europe over the past few weeks have led to some of the worst flooding the region has witnessed in more than a century. The floods have killed more than 100 people in Germany, Russia, Austria, Hungary, and the Czech Republic and have led to as much as $20 billion in damage. This false-color image of the Elbe River and its tributaries was taken on August 20, 2002, by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The floodwaters that inundated Dresden, Germany, earlier this week have moved north. As can be seen, the river resembles a fairly large lake in the center of the image just south of the town of Wittenberg. Flooding was also bad further downriver in the towns of Maqgdeburge and Hitzacker. Roughly 20,000 people were evacuated from their homes in northern Germany. Fifty thousand troops, border police, and technical assistance workers were called in to combat the floods along with 100,000 volunteers. The floodwaters are not expected to badly affect Hamburg, which sits on the mouth of the river on the North Sea. Credit:Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  1. On Flood Alert

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ Aseries of heavy storms since early May led to severe flooding and landslides in south and southwest China,causing heaw casualties and economic losses.Severe convective weather such as downpours,gusts,hail and thunderstorms attacked these areas over a week from May 5.

  2. Fast Flooding over Manhattan

    CERN Document Server

    Clementi, Andrea; Silvestri, Riccardo

    2010-01-01

    We consider a Mobile Ad-hoc NETwork (MANET) formed by n agents that move at speed V according to the Manhattan Random-Way Point model over a square region of side length L. The resulting stationary (agent) spatial probability distribution is far to be uniform: the average density over the "central zone" is asymptotically higher than that over the "suburb". Agents exchange data iff they are at distance at most R within each other. We study the flooding time of this MANET: the number of time steps required to broadcast a message from one source agent to all agents of the network in the stationary phase. We prove the first asymptotical upper bound on the flooding time. This bound holds with high probability, it is a decreasing function of R and V, and it is tight for a wide and relevant range of the network parameters (i.e. L, R and V). A consequence of our result is that flooding over the sparse and highly-disconnected suburb can be as fast as flooding over the dense and connected central zone. Rather surprisin...

  3. Variations in eruptive style and depositional processes of Neoproterozoic terrestrial volcano-sedimentary successions in the Hamid area, North Eastern Desert, Egypt

    Science.gov (United States)

    Khalaf, Ezz El Din Abdel Hakim

    2013-07-01

    Two contrasting Neoproterozoic volcano-sedimentary successions of ca. 600 m thickness were recognized in the Hamid area, Northeastern Desert, Egypt. A lower Hamid succession consists of alluvial sediments, coherent lava flows, pyroclastic fall and flow deposits. An upper Hamid succession includes deposits from pyroclastic density currents, sills, and dykes. Sedimentological studies at different scales in the Hamid area show a very complex interaction of fluvial, eruptive, and gravitational processes in time and space and thus provided meaningful insights into the evolution of the rift sedimentary environments and the identification of different stages of effusive activity, explosive activity, and relative quiescence, determining syn-eruptive and inter-eruptive rock units. The volcano-sedimentary deposits of the study area can be ascribed to 14 facies and 7 facies associations: (1) basin-border alluvial fan, (2) mixed sandy fluvial braid plain, (3) bed-load-dominated ephemeral lake, (4) lava flows and volcaniclastics, (5) pyroclastic fall deposits, (6) phreatomagmatic volcanic deposits, and (7) pyroclastic density current deposits. These systems are in part coeval and in part succeed each other, forming five phases of basin evolution: (i) an opening phase including alluvial fan and valley flooding together with a lacustrine period, (ii) a phase of effusive and explosive volcanism (pulsatory phase), (iii) a phase of predominant explosive and deposition from base surges (collapsing phase), and (iv) a phase of caldera eruption and ignimbrite-forming processes (climactic phase). The facies architectures record a change in volcanic activity from mainly phreatomagmatic eruptions, producing large volumes of lava flows and pyroclastics (pulsatory and collapsing phase), to highly explosive, pumice-rich plinian-type pyroclastic density current deposits (climactic phase). Hamid area is a small-volume volcano, however, its magma compositions, eruption styles, and inter

  4. Flood model for Brazil

    Science.gov (United States)

    Palán, Ladislav; Punčochář, Petr

    2017-04-01

    Looking on the impact of flooding from the World-wide perspective, in last 50 years flooding has caused over 460,000 fatalities and caused serious material damage. Combining economic loss from ten costliest flood events (from the same period) returns a loss (in the present value) exceeding 300bn USD. Locally, in Brazil, flood is the most damaging natural peril with alarming increase of events frequencies as 5 out of the 10 biggest flood losses ever recorded have occurred after 2009. The amount of economic and insured losses particularly caused by various flood types was the key driver of the local probabilistic flood model development. Considering the area of Brazil (being 5th biggest country in the World) and the scattered distribution of insured exposure, a domain covered by the model was limited to the entire state of Sao Paolo and 53 additional regions. The model quantifies losses on approx. 90 % of exposure (for regular property lines) of key insurers. Based on detailed exposure analysis, Impact Forecasting has developed this tool using long term local hydrological data series (Agencia Nacional de Aguas) from riverine gauge stations and digital elevation model (Instituto Brasileiro de Geografia e Estatística). To provide most accurate representation of local hydrological behaviour needed for the nature of probabilistic simulation, a hydrological data processing focused on frequency analyses of seasonal peak flows - done by fitting appropriate extreme value statistical distribution and stochastic event set generation consisting of synthetically derived flood events respecting realistic spatial and frequency patterns visible in entire period of hydrological observation. Data were tested for homogeneity, consistency and for any significant breakpoint occurrence in time series so the entire observation or only its subparts were used for further analysis. The realistic spatial patterns of stochastic events are reproduced through the innovative use of d-vine copula

  5. Morrowan stratigraphy, depositional systems, and hydrocarbon accumulation, Sorrento field, Cheyenne County, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Orchard, D.M.; Kidwell, M.R.

    1983-08-01

    The Sorrento field, located on the western flank of the present-day Las Animas arch in western Cheyenne County, Colorado, has approximately 29 million bbl of oil and 12 bcf of gas in place in sandstones of the Lower Pennsylvanian Morrow units. The sandstones were deposited in a fluvially dominated deltaic system, and the trap for the hydrocarbon accumulation is formed by pinch-out of this deltaic system onto regional dip. The primary reservoirs are point-bar deposits. At the Sorrento field, the basal Keyes limestone member of the Morrow formation rests unconformably on the Mississippian St. Louis Formation. Above the Keyes limestone, the Morrow shale is 180 to 214 ft (55 to 65 m) thick, and locally contains reservoir sands. Gas/oil and oil/water contacts are not uniform through the field owing to discontinuities between separate point bars. One such discontinuity is formed by an apparent mud plug of an abandoned channel separating two point bars on the southeastern end of the field. In a well 7000 ft (2100 m) from the edge of the meander belt, the regressive sequence is represented by a shoreline siltstone unit 8 ft (2 m) thick with flaser bedding, graded bedding, load structures, and rare wave-ripple cross-bedding overlain by 3 ft (1 m) of flood-plain mudstone and coal with no indication of proximity to a nearby sand system.

  6. A depositional model for the Taylor coal bed, Martin and Johnson counties, eastern Kentucky

    Science.gov (United States)

    Andrews, W.M.; Hower, J.C.; Ferm, J.C.; Evans, S.D.; Sirek, N.S.; Warrell, M.; Eble, C.F.

    1996-01-01

    This study investigated the Taylor coal bed in Johnson and Martin counties, eastern Kentucky, using field and petrographic techniques to develop a depositional model of the coal bed. Petrography and chemistry of the coal bed were examined. Multiple benches of the Taylor coal bed were correlated over a 10 km distance. Three sites were studied in detail. The coal at the western and eastern sites were relatively thin and split by thick clastic partings. The coal at the central site was the thickest and unsplit. Two major clastic partings are included in the coal bed. Each represents a separate and distinct fluvial splay. The Taylor is interpreted to have developed on a coastal plain with periodic flooding from nearby, structurally-controlled fluvial systems. Doming is unlikely due to the petrographic and chemical trends, which are inconsistent with modern Indonesian models. The depositional history and structural and stratigraphic setting suggest contemporaneous structural influence on thickness and quality of the Taylor coal bed in this area.

  7. Geological characteristics of the peat deposits in Costa Rica (preliminary study)

    Energy Technology Data Exchange (ETDEWEB)

    Mora, S.; Cohen, A.D.; Raymond, R.; Alvarado, A.; Malavassi, L.

    1986-04-01

    Wide areas containing peat deposits have been found in Costa Rica. Three of them were selected for the preliminary evaluation. In the Talamanca range peat occurs as a thin blanket deposit about 1 m thick in an area of about 150 km/sup 2/. It is very decomposed (about 28% fibers), with high ash content, (21%) and extensively bioturbated. It has the lowest water content (84%), pH, fixed carbon (23%) and sulphur (0.2%) of all the sampled sites, However, it has the highest bulk density (0.22 g/cm/sup 3/) and volatile components (55%). Its calorific value averages 7700 Btu/lb, dry. In Medio Queso de Upala, several peat horizons are interbedded with alluvium layers within a 70 km/sup 2/ flood plain. They have the highest calorific values (8000 Btu/lb, dry), fixed carbon (30%) and ash content (22%). Their fiber content is low (27%), and the bulk density 0.20 g/cm/sup 3/. In El Silencio, near Siquirres, the thickness of the main layer exceeds 3.5 m, averaging 19% of ash, 53% of fibers, 5.8 pH, 0.6% of sulphur, 0.13 g/cm/sup 3/ bulk density, and 7500 Btu/lb, dry. (5 refs.)

  8. Coastal morphodynamics and Chenier-Plain evolution in southwestern Louisiana, USA: A geomorphic model

    Science.gov (United States)

    McBride, Randolph A.; Taylor, Matthew J.; Byrnes, Mark R.

    2007-08-01

    Using 28 topographic profiles, air-photo interpretation, and historical shoreline-change data, coastal processes were evaluated along the Chenier Plain to explain the occurrence, distribution, and geomorphic hierarchy of primary landforms, and existing hypotheses regarding Chenier-Plain evolution were reconsidered. The Chenier Plain of SW Louisiana, classified as a low-profile, microtidal, storm-dominated coast, is located west and downdrift of the Mississippi River deltaic plain. This Late-Holocene, marginal-deltaic environment is 200 km long and up to 30 km wide, and is composed primarily of mud deposits capped by marsh interspersed with thin sand- and shell-rich ridges ("cheniers") that have elevations of up to 4 m. In this study, the term "ridge" is used as a morphologic term for a narrow, linear or curvilinear topographic high that consists of sand and shelly material accumulated by waves and other physical coastal processes. Thus, most ridges in the Chenier Plain represent relict open-Gulf shorelines. On the basis of past movement trends of individual shorelines, ridges may be further classified as transgressive, regressive, or laterally accreted. Geomorphic zones that contain two or more regressive, transgressive, or laterally accreted ridges are termed complexes. Consequently, we further refine the Chenier-Plain definition by Otvos and Price [Otvos, E.G. and Price, W.A., 1979. Problems of chenier genesis and terminology—an overview. Marine Geology, 31: 251-263] and define Chenier Plain as containing at least two or more chenier complexes. Based on these definitions, a geomorphic hierarchy of landforms was refined relative to dominant process for the Louisiana Chenier Plain. The Chenier Plain is defined as a first-order feature (5000 km 2) composed of three second-order features (30 to 300 km 2): chenier complex, beach-ridge complex, and spit complex. Individual ridges of each complex type were further separated into third-order features: chenier, beach

  9. Chinese tallow: Invading the southeastern Coastal Plain

    Science.gov (United States)

    ,

    2000-01-01

    Chinese tallow is an ornamental tree with colorful autumn foliage that can survive full sunlight and shade, flooding, drought, and in some cases fire. To horticulturists this kind of tree sounds like a dream, but to ecologists, land managers, and land owners this kind of tree can be a nightmare, especially when it invades an area and takes over native vegetation. Chinese tallow (Triadica sebifera), a nonnative tree from China, is currently transforming the southeastern Coastal Plain.Over the last 30 years, Chinese tallow has become a common tree in old fields and bottomland swamps of coastal Louisiana. Several studies at the U.S. Geological Survey’s National Wetlands Research Center (NWRC), Lafayette, Louisiana, are aimed at understanding the factors that contribute to Chinese tallow growth, spread, and management.When tallow invades, it eventually monopolizes an area, creating a forest without native animal or plant species. This tree exhibits classic traits of most nonnative invaders: it is attractive so people want to distribute it, it has incredible resiliency, it grows quickly and in a variety of soils, and it is resistant to pests.In the coastal prairie of Louisiana and Texas, Chinese tallow can grow up to 30 feet and shade out native sun-loving prairie species. The disappearing of prairie species is troublesome because less than 1% of original coastal prairie remains, and in Louisiana, less than 500 of the original 2.2 million acres still exist.Tallow reproduces and grows quickly and can cause large-scale ecosystem modification (fig. 1). For example, when it completely replaces native vegetation, it has a negative effect on birds by degrading the habitat. Besides shading out grasses that cattle like to eat, it can also be potentially harmful to humans and animals because of its berries (fig. 2) and plant sap that contain toxins. There is some concern its leaves may shed toxins that change the soil chemistry and make it difficult for other plants to grow.

  10. Exit and Paradise Creek Braid Plain Kilometers, 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset consists of points designating braid plain kilometers, or distance along the braid plain centerline, for the 2012 active braid plain of Exit Creek and...

  11. GIS Support for Flood Rescue

    DEFF Research Database (Denmark)

    Liang, Gengsheng; Mioc, Darka; Anton, François

    2007-01-01

    Under flood events, the ground traffic is blocked in and around the flooded area due to damages to roads and bridges. The traditional transportation network may not always help people to make a right decision for evacuation. In order to provide dynamic road information needed for flood rescue, we...... developed an adaptive web-based transportation network application using Oracle technology. Moreover, the geographic relationships between the road network and flood areas are taken into account. The overlay between the road network and flood polygons is computed on the fly. This application allows users...... to retrieve the shortest and safest route in Fredericton road network during flood event. It enables users to make a timely decision for flood rescue. We are using Oracle Spatial to deal with emergency situations that can be applied to other constrained network applications as well....

  12. Development of a New Generation of Flood Inundation Maps—A Case Study of the Coastal City of Tainan, Taiwan

    Directory of Open Access Journals (Sweden)

    Dong-Jiing Doong

    2016-11-01

    Full Text Available Flood risk management has become a growing priority for city managers and disaster risk prevention agencies worldwide. Correspondingly, large investments are made towards data collection, archiving and analysis and technologies such as geographic information systems (GIS and remote sensing play important role in this regard. GIS technologies offer valuable means for delineation of flood plains, zoning of areas that need protection from floods and identification of plans for development and scoping of various kinds of flood protection measures. Flood inundation maps (FIMs are particularly useful in planning flood disaster risk responses. The purpose of the present paper is to describe efforts in developing new generation of FIMs at the city scale and to demonstrate effectiveness of such maps in the case of the coastal city of Tainan, Taiwan. In the present work, besides pluvial floods, the storm surge influence is also considered. The 1D/2D coupled model SOBEK was used for flood simulations. Different indicators such as Probability of Detection (POD and Scale of Accuracy (SA were applied in the calibration and validation stages of the work and their corresponding values were found to be up to 88.1% and 68.0%, respectively. From the overall analysis, it came up that land elevation, tidal phase, and storm surge are the three dominant factors that influence flooding in Tainan. A large number of model simulations were carried out in order to produce FIMs which were then effectively applied in the stakeholder engagement process.

  13. Individual actual or perceived property flood risk: did it predict evacuation from Hurricane Isabel in North Carolina, 2003?

    Science.gov (United States)

    Horney, Jennifer A; Macdonald, Pia D M; Van Willigen, Marieke; Berke, Philip R; Kaufman, Jay S

    2010-03-01

    Individual perception of risk has consistently been considered an important determinant of hurricane evacuation in published studies and reviews. Adequate risk assessment is informed by environmental and social cues, as well as evacuation intentions and past disaster experience. This cross-sectional study measured perceived flood risk of 570 residents of three coastal North Carolina counties, compared their perception with actual risk determined by updated flood plain maps, and determined if either was associated with evacuation from Hurricane Isabel in 2003. Census blocks were stratified by flood zone and 30 census blocks were randomly selected from each flood zone. Seven interviews were conducted at random locations within selected blocks. Bivariate and multivariable analyses were conducted to produce crude and adjusted risk differences. Neither the designated flood zone of the parcel where the home was located nor the residents' perceived flood risk was associated with evacuation from Hurricane Isabel in the bivariate analysis. In the multivariable analysis, intention to evacuate and home type were important confounders of the association between actual risk and evacuation. The belief that one is at high risk of property damage or injury is important in evacuation decision making. However, in this study, while coastal residents' perceived risk of flooding was correlated with their actual flood risk, neither was associated with evacuation. These findings provide important opportunities for education and intervention by policymakers and authorities to improve hurricane evacuation rates and raise flood risk awareness.

  14. Flood profiles of the Alafia River, west-central Florida, computed by step-backwater method

    Science.gov (United States)

    Robertson, A.F.

    1977-01-01

    The Alafia River is a coastal stream that discharges into Hillsborough Bay. The river and its two principal tributaries, North Prong Alafia River and South Prong Alafia River, drain an area of 420 sq mi of predominantly rural land. However, near the coast, urban residential developments are increasing. The flood plain of the river is subject to flooding, particularly during large regional storms. Peak-discharge frequencies have been determined for data available at two gaging stations in the basin. The flood profiles for peak discharges of recurrence intervals of 2.33, 5, 10, 25, 50, 100, and 200 years have been determined using the step-backwater method. These profiles can be used in conjunction with topographic maps to delineate the area of flooding. Flood profiles were not determined for the tidally affected area near the mouth of the river. Flood marks were located that can be associated with the 1960 flood which occurred when Hurricane Donna passed over the area. (Woodard-USGS)

  15. Effects on the upstream flood inundation caused from the operation of Chao Phraya Dam

    Directory of Open Access Journals (Sweden)

    Sutham Visutimeteegorn

    2007-11-01

    Full Text Available During the flooding events, the operation of Chao Phraya Dam to control downstream water discharge is one of the causes of the inundation occuring over the upstream area. The purposes of this research are to study the effects of the operation of Chao Phraya Dam upon the upstream flood inundation and to find out the new measures of the flood mitigation in the upstream areas of Chao Phraya Dam by using a hydrodynamic model. The results show that Manning's n in the Chao Phraya River and its tributaries is 0.030-0.035 in the main channels and 0.050-0.070 in the flood plain areas. The backwater due to the operation of the Chao Praya dam affects as far as 110 kilometers upstream. New methods of water diversion can mitigate the flood inundation without the effect on the floating rice fields. The construction of reservoirs in the Upper Sakaekang River Basin and the Upper Yom River Basin will mitigate the flood not only in their own basins but also in the Lower Chao Phraya River Basin. The coordinated operation of the Chao Phraya Dam, the regulators and the upper basin reservoirs will efficiently mitigate the flood inundation.

  16. Flood marks of the 1813 flood in the Central Europe

    Science.gov (United States)

    Miklanek, Pavol; Pekárová, Pavla; Halmová, Dana; Pramuk, Branislav; Bačová Mitková, Veronika

    2014-05-01

    In August 2013, 200 years have passed since the greatest and most destructive floods known in the Slovak river basins. The flood affected almost the entire territory of Slovakia, northeastern Moravia, south of Poland. River basins of Váh (Orava, Kysuca), Poprad, Nitra, Hron, Torysa, Hornád, upper and middle Vistula, Odra have been most affected. The aim of this paper is to map the flood marks documenting this catastrophic flood in Slovakia. Flood marks and registrations on the 1813 flood in the Váh river basin are characterized by great diversity and are written in Bernolák modification of Slovak, in Latin, German and Hungarian. Their descriptions are stored in municipal chronicles and Slovak and Hungarian state archives. The flood in 1813 devastated the entire Váh valley, as well as its tributaries. Following flood marks were known in the Vah river basin: Dolná Lehota village in the Orava river basin, historical map from 1817 covering the Sučany village and showing three different cross-sections of the Váh river during the 1813 flood, flood mark in the city of Trenčín, Flood mark in the gate of the Brunovce mansion, cross preserved at the old linden tree at Drahovce, and some records in written documents, e.g. Cifer village. The second part of the study deals with flood marks mapping in the Hron, Hnilec and Poprad River basins, and Vistula River basin in Krakow. On the basis of literary documents and the actual measurement, we summarize the peak flow rates achieved during the floods in 1813 in the profile Hron: Banská Bystrica. According to recent situation the 1813 flood peak was approximately by 1.22 m higher, than the flood in 1974. Also in the Poprad basin is the August 1813 flood referred as the most devastating flood in last 400 years. The position of the flood mark is known, but the building was unfortunately removed later. The water level in 1813 was much higher than the water level during the recent flood in June 2010. In Cracow the water level

  17. Variations in flood magnitude-effect relations and the implications for flood risk assessment and river management

    Science.gov (United States)

    Hooke, J. M.

    2015-12-01

    In spite of major physical impacts from large floods, present river management rarely takes into account the possible dynamics and variation in magnitude-impact relations over time in flood risk mapping and assessment nor incorporates feedback effects of changes into modelling. Using examples from the literature and from field measurements over several decades in two contrasting environments, a semi-arid region and a humid-temperate region, temporal variations in channel response to flood events are evaluated. The evidence demonstrates how flood physical impacts can vary at a location over time. The factors influencing that variation on differing timescales are examined. The analysis indicates the importance of morphological changes and trajectory of adjustment in relation to thresholds, and that trends in force or resistance can take place over various timescales, altering those thresholds. Sediment supply can also change with altered connectivity upstream and changes in state of hillslope-channel coupling. It demonstrates that seasonal timing and sequence of events can affect response, particularly deposition through sediment supply. Duration can also have a significant effect and modify the magnitude relation. Lack of response or deposits in some events can mean that flood frequency using such evidence is underestimated. A framework for assessment of both past and possible future changes is provided which emphasises the uncertainty and the inconstancy of the magnitude-impact relation and highlights the dynamic factors and nature of variability that should be considered in sustainable management of river channels.

  18. Citizen involvement in flood risk governance: flood groups and networks

    Directory of Open Access Journals (Sweden)

    Twigger-Ross Clare

    2016-01-01

    Full Text Available Over the past decade has been a policy shift withinUK flood risk management towards localism with an emphasis on communities taking ownership of flood risk. There is also an increased focus on resilience and, more specifically, on community resilience to flooding. This paper draws on research carried out for UK Department for Environment Food and Rural Affairs to evaluate the Flood Resilience Community Pathfinder (FRCP scheme in England. Resilience is conceptualised as multidimensional and linked to exisiting capacities within a community. Creating resilience to flooding is an ongoing process of adaptation, learning from past events and preparing for future risks. This paper focusses on the development of formal and informal institutions to support improved flood risk management: institutional resilience capacity. It includes new institutions: e.g. flood groups, as well as activities that help to build inter- and intra- institutional resilience capacity e.g. community flood planning. The pathfinder scheme consisted of 13 projects across England led by local authorities aimed at developing community resilience to flood risk between 2013 – 2015. This paper discusses the nature and structure of flood groups, the process of their development, and the extent of their linkages with formal institutions, drawing out the barriers and facilitators to developing institutional resilience at the local level.

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

    Science.gov (United States)

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

    2016-07-01

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

  20. Magnitude and extent of flooding at selected river reaches in western Washington, January 2009

    Science.gov (United States)

    Mastin, M.C.; Gendaszek, A.S.; Barnas, C.R.

    2010-01-01

    A narrow plume of warm, moist tropical air produced prolonged precipitation and melted snow in low-to-mid elevations throughout western Washington in January 2009. As a result, peak-of-record discharges occurred at many long-term streamflow-gaging stations in the region. A disaster was declared by the President for eight counties in Washington State and by May 2009, aid payments by the Federal Emergency Management Agency (FEMA) had exceeded $17 million. In an effort to document the flood and to obtain flood information that could be compared with simulated flood extents that are commonly prepared in conjunction with flood insurance studies by FEMA, eight stream reaches totaling 32.6 miles were selected by FEMA for inundation mapping. The U.S. Geological Survey?s Washington Water Science Center used a survey-grade global positioning system (GPS) the following summer to survey high-water marks (HWMs) left by the January 2009 flood at these reaches. A Google Maps (copyright) application was developed to display all HWM data on an interactive mapping tool on the project?s web site soon after the data were collected. Water-surface profiles and maps that display the area and depth of inundation were produced through a geographic information system (GIS) analysis that combined surveyed HWM elevations with Light Detection and Ranging (LiDAR)-derived digital elevation models of the study reaches and surrounding terrain. In several of the reaches, floods were well confined in their flood plains and were relatively straightforward to map. More common, however, were reaches with more complicated hydraulic geometries where widespread flooding resulted in flows that separated from the main channel. These proved to be more difficult to map, required subjective hydrologic judgment, and relied on supplementary information, such as aerial photographs and descriptions of the flooding from local landowners and government officials to obtain the best estimates of the extent of flooding.

  1. PLAINS CO2 REDUCTION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; John A. Harju; Erin M. O' Leary; James A. Sorensen; Daniel J. Daly; Melanie D. Jensen; Thea E. Reikoff

    2004-10-01

    The Plains CO{sub 2} Reduction (PCOR) Partnership continues to make great progress. Task 2 (Technology Deployment) focused on developing information regarding deployment issues to support Task 5 (Modeling and Phase II Action Plans) by providing information to be used to assess CO{sub 2} sequestration opportunities in the PCOR Partnership region. Task 3 (Public Outreach) focused on developing an informational video about CO{sub 2} sequestration. Progress in Task 4 (Sources, Sinks, and Infrastructure) included the continued collection of data regarding CO{sub 2} sources and sinks and data on the performance and costs for CO{sub 2} separation, capture, treatment, and compression for pipeline transportation. Task 5 focused on screening and qualitatively assessing sequestration options. Task 5 activities also continue to be useful in structuring data collection and other activities in Tasks 2, 3, and 5.

  2. Planetary plains: subsidence and warping

    Science.gov (United States)

    Kochemasov, G.

    fabric of oceanic floors. Short, medium wave undulations of Pacific's floor (A. Cazenave et al., 1992; D. McAdoo & K. Marks, 1992) present lineations underlining its whole shape. NE lineations predominate on its northern sub-basin, NW lineations on its southern one. They cross at the equatorial zone and together with some other directions give a pattern resembling that observed on the venusian surface. The venusian regional plains typically deformed by wrinkle ridges show interesting similarities to volcanic plains on the Moon and Mars [3]. A subsidence along with warpings can squeeze out some "superfluous" material to surface through planetary scale fissures. This material builds mid-oceanic ridges and huge Hawaii volcano. The Cassini Regio on Iapetus is crossed in the equatorial plain by the dark ridge in some places high 20 km. References: [1] Kochemasov G. G. (2004) Mars and Earth: two dichotomies - one cause. In Workshop on "Hemispheres 1 apart: the origin and modification of the martian crustal dichotomy", LPI Contribution # 1203, Lunar and Planetary Institute, Houston, p. 37. [2] Kochemasov G.G.(1999) Theorems of wave planetary tectonics // Geophys. Res. Abstr. v.1, #3, p.700 . [3] Basilevsky A.T., Head J.W. (2006) Impact craters on regional plains in Venus: Age relations with wrinkle ridges and implications for the geological evolution of Venus // JGR, v.111, EO3006, doi: 10.1029/2005JE002473, 2006. 2

  3. PLAINS CO2 REDUCTION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; John A. Harju; Erin M. O' Leary; James A. Sorensen; Daniel J. Daly; Melanie D. Jensen; Thea E. Reikoff

    2005-01-01

    The Plains CO{sub 2} Reduction (PCOR) Partnership continues to make great progress. Task 2 (Technology Deployment) focused on developing information regarding deployment issues to support Task 5 (Modeling and Phase II Action Plans) by providing information to be used to assess CO{sub 2} sequestration opportunities in the PCOR Partnership region. Task 3 (Public Outreach) focused on developing an informational video about CO{sub 2} sequestration. Progress in Task 4 (Sources, Sinks, and Infrastructure) included the continued collection of data regarding CO{sub 2} sources and sinks and data on the performance and costs for CO{sub 2} separation, capture, treatment, and compression for pipeline transportation. Task 5 focused on screening and qualitatively assessing sequestration options. Task 5 activities also continue to be useful in structuring data collection and other activities in Tasks 2, 3, and 5.

  4. PLAINS CO2 REDUCTION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; John A. Harju; Erin M. O' Leary; James A. Sorensen; Daniel J. Daly; Melanie D. Jensen; Thea E. Reikoff

    2005-01-01

    The Plains CO{sub 2} Reduction (PCOR) Partnership continues to make great progress. Task 2 (Technology Deployment) focused on developing information regarding deployment issues to support Task 5 (Modeling and Phase II Action Plans) by providing information to be used to assess CO{sub 2} sequestration opportunities in the PCOR Partnership region. Task 3 (Public Outreach) focused on developing an informational video about CO{sub 2} sequestration. Progress in Task 4 (Sources, Sinks, and Infrastructure) included the continued collection of data regarding CO{sub 2} sources and sinks and data on the performance and costs for CO{sub 2} separation, capture, treatment, and compression for pipeline transportation. Task 5 focused on screening and qualitatively assessing sequestration options. Task 5 activities also continue to be useful in structuring data collection and other activities in Tasks 2, 3, and 5.

  5. Physico-geographical characterization of the landscape denominated flood-prone lowlands. The case of the Protected Natural Reserve Balamkín, Campeche

    OpenAIRE

    Alvaro Gerardo Palacio Aponte; Rodolfo Noriega Trejo; Pedro Zamora Crecendo

    2012-01-01

    This paper describes landscape areas locally known as flood-prone lowlands, found in southeastern Campeche, Mexico. Functionally, these are not restricted to cumulative plains covered with flooded soils (gleysols) and waterborne vegetation ("palo de tinte"), as suggested in the past. This study demonstrates that these landscape areas are closely linked and correlated to geoforms and adjacent ecosystems. In order to support these correlations, all landscape components are described, and the im...

  6. Our fingerprint in tsunami deposits - anthropogenic markers as a new tsunami identification tool

    Science.gov (United States)

    Bellanova, P.; Schwarzbauer, J.; Reicherter, K. R.; Jaffe, B. E.; Szczucinski, W.

    2016-12-01

    Several recent geochemical studies have focused on the use of inorganic indicators to evaluate a tsunami origin of sediment in the geologic record. However, tsunami transport not only particulate sedimentary material from marine to terrestrial areas (and vice versa), but also associated organic material. Thus, tsunami deposits may be characterized by organic-geochemical parameters. Recently increased attention has been given to the use of natural organic substances (biomarkers) to identify tsunami deposits. To date no studies have been made investigating anthropogenic organic indicators in recent tsunami deposits. Anthropogenic organic markers are more sensitive and reliable markers compared to other tracers due to their specific molecular structural properties and higher source specificity. In this study we evaluate whether anthropogenic substances are useful indicators for determining whether an area has been inundated by a tsunami. We chose the Sendai Plain and Sanemoura and Oppa Bays, Japan, as study sites because the destruction of infrastructure by flooding released environmental pollutants (e.g., fuels, fats, tarmac, plastics, heavy metals, etc.) contaminating large areas of the coastal zone during the 2011 Tohoku-oki tsunami. Organic compounds from the tsunami deposits are extracted from tsunami sediment and compared with the organic signature of unaffected pre-tsunami samples using gas chromatography-mass spectrometry (GS/MS) based analyses. For the anthropogenic markers, compounds such as soil derived pesticides (DDT), source specific PAHs, halogenated aromatics from industrial sources were detected and used to observe the inland extent and the impact of the Tohoku-oki tsunami on the coastal region around Sendai.

  7. Floods and tsunamis.

    Science.gov (United States)

    Llewellyn, Mark

    2006-06-01

    Floods and tsunamis cause few severe injuries, but those injuries can overwhelm local areas, depending on the magnitude of the disaster. Most injuries are extremity fractures, lacerations, and sprains. Because of the mechanism of soft tissue and bone injuries, infection is a significant risk. Aspiration pneumonias are also associated with tsunamis. Appropriate precautionary interventions prevent communicable dis-ease outbreaks. Psychosocial health issues must be considered.

  8. Colombia Mi Pronostico Flood Application: Updating and Improving the Mi Pronostico Flood Web Application to Include an Assessment of Flood Risk

    Science.gov (United States)

    Rushley, Stephanie; Carter, Matthew; Chiou, Charles; Farmer, Richard; Haywood, Kevin; Pototzky, Anthony, Jr.; White, Adam; Winker, Daniel

    2014-01-01

    Colombia is a country with highly variable terrain, from the Andes Mountains to plains and coastal areas, many of these areas are prone to flooding disasters. To identify these risk areas NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) was used to construct a digital elevation model (DEM) for the study region. The preliminary risk assessment was applied to a pilot study area, the La Mosca River basin. Precipitation data from the National Aeronautics and Space Administration (NASA) Tropical Rainfall Measuring Mission (TRMM)'s near-real-time rainfall products as well as precipitation data from the Instituto de Hidrologia, Meteorologia y Estudios Ambientales (the Institute of Hydrology, Meteorology and Environmental Studies, IDEAM) and stations in the La Mosca River Basin were used to create rainfall distribution maps for the region. Using the precipitation data and the ASTER DEM, the web application, Mi Pronóstico, run by IDEAM, was updated to include an interactive map which currently allows users to search for a location and view the vulnerability and current weather and flooding conditions. The geospatial information was linked to an early warning system in Mi Pronóstico that can alert the public of flood warnings and identify locations of nearby shelters.

  9. Atmospheric Rivers, Floods, and Flash Floods in California

    Science.gov (United States)

    Skelly, Klint T.

    Atmospheric Rivers (ARs) are long (>2000 km), narrow (<1000 km) corridors of enhanced vertically integrated water vapor (IWV) and enhanced IWV transport (IVT). The landfall of ARs along the U.S. West Coast have been linked to extreme precipitation and flooding/flash flooding in regions of complex topography. The objective of this study is to investigate the relationship between a 10 water-year (2005-2014) climatology of floods, flash floods, and landfalling ARs. The ARs in this study are defined using IVT following the Rutz et al. (2013) methodology, whereas floods and flash floods are identified by the National Centers for Environmental Information (NCEI) Storm Events Database. The results of this study indicate that landfalling ARs are present on a majority of days that there are floods in northern California. Landfalling ARs are predominantly present on a majority of days that there are flash flood reports during the cold-season (November-March); however, the North American monsoon is present on days that there are flash flood reports during the warm-season (April-October). Two exemplary case studies are provided to illustrate the hydrologic impact of landfalling ARs. The first case study illustrated a flood event that occurred in associated with three landfalling ARs that produced 800 mm in regions over the Russian River watershed in northern California and the second case study illustrated a flash flood event that occurred in association with a landfalling AR that produced ˜225 mm of precipitation in regions over the Santa Ynez xii watershed in which produced a flash flood over the southern portions of Santa Barbara County in southern California.

  10. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>20070291 Gong Ping (Northern Fujian Geological Party, Shaozou 354000) Discussion on Geological Characteristics and Control Factors of the Shimen Au-polymetallic Deposit in Zhenghe County, Fujian Province (Geology of Fujian, ISSN1001-3970, CN38-1080/P, 25(1), 2006, p.18-24, 2 illus., 2 tables, 1 ref.) Key words: gold deposits, polymetallic deposits, Fujian Province

  11. 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.

  12. Preliminary geologic map of the Santa Barbara coastal plain area, Santa Barbara County, California

    Science.gov (United States)

    Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Stone, Paul; Powell, Charles L.; Gurrola, Larry D.; Selting, Amy J.; Brandt, Theodore R.

    2002-01-01

    This report presents a new geologic digital map of the Santa Barbara coastal plain area at a compilation scale of 1:24,000 (one inch on the map = 2,000 feet on the ground) and with a horizontal positional accuracy of at least 20 m. This preliminary map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying and adjacent to the coastal plain within the contiguous Santa Barbara and Goleta 7.5' quadrangles. A planned second version will extend the mapping westward into the adjoining Dos Pueblos Canyon quadrangle and eastward into the Carpinteria quadrangle. The mapping presented here results from the collaborative efforts of geologists with the U.S. Geological Survey Southern California Areal Mapping Project (SCAMP) (Minor, Kellogg, Stanley, Stone, and Powell) and the tectonic geomorphology research group at the University of California at Santa Barbara (Gurrola and Selting). C.L. Powell, II, performed all new fossil identifications and interpretations reported herein. T.R. Brandt designed and edited the GIS database,performed GIS database integration and created the digital cartography for the map layout. The Santa Barbara coastal plain is located in the western Transverse Ranges physiographic province along a west-trending segment of the southern California coastline about 100 km (62 mi) northwest of Los Angeles. The coastal plain region, which extends from the Santa Ynez Mountains on the north to the Santa Barbara Channel on the south, is underlain by numerous active and potentially active folds and partly buried thrust faults of the Santa Barbara fold and fault belt. Strong earthquakes that occurred in the region in 1925 (6.8 magnitude) and 1978 (5.1 magnitude) are evidence that such structures pose a significant earthquake hazard to the approximately 200,000 people living within the major coastal population centers of Santa Barbara and Goleta. Also, young landslide deposits along the steep lower flank of the Santa

  13. Bank accretion and the development of vegetated depositional surfaces along modified alluvial channels

    Science.gov (United States)

    Hupp, C.R.; Simon, A.

    1991-01-01

    This paper describes the recovery of stable bank form and development of vegetated depositional surfaces along the banks of channelized West Tennessee streams. Most perennial streams in West Tennessee were straightened and dredged since the turn of the century. Patterns of fluvial ecological responses to channelization have previously been described by a six-stage model. Dendrogeomorphic (tree-ring) techniques allowed the determination of location, timing, amount, and rate of bank-sediment deposition. Channel cross sections and ecological analyses made at 101 locations along 12 streams, encompassing bends and straight reaches, show that channel and bank processes initially react vertically to channelization through downcutting. A depositional surface forms on banks once bed-degradation and heightened bank mass wasting processes have eased or slowed. The formation of this depositional surface marks the beginning of bank recovery from channelization. Dominating lateral processes, characteristic of stable or natural channels, return during the formation and expansion of the depositional surface, suggesting a relation with thalweg deflection, point-bar development, and meanderloop extension. Characteristic woody riparian vegetation begins to grow as this depositional surface develops and becomes part of the process and form of restabilizing banks. The depositional surface initially forms low on the bank and tends to maintain a slope of about 24??. Mean accretion rates ranges from 5.9 cm/yr on inside bends to 0 cm/yr on most outside bends; straight reaches have a mean-accretion rate of 4.2 cm/yr. The relatively stable, convex upward, depositional surface expands and ultimately attaches to the flood plain. The time required for the recovery process to reach equilibrium averaged about 50 years. Indicative pioneer speccies of woody riparian vegetation include black willow, river birch, silver maple, and boxelder. Stem densities generally decrease with time after and

  14. Evaluation of the Benefit of Flood Reduction by Artificial Groundwater Recharge Lake Operation in a Coastal Area

    Science.gov (United States)

    Chen, Ching-Nuo; Tsai, Chih-Heng

    2017-04-01

    Inundation disasters often occur in the southwestern coastal plains of Taiwan. The coastal plains suffers mostly from land-subsidence, surface water is difficult to be drained during the typhoon period, leading to more severe flood disasters. Global climate warming has become more significant, which in turn has resulted in the increase in amplitude and frequency of climate change related disasters. In addition, climate change also induces a rise in sea water level year by year. The rise in sea water level does not only weakens the function of existing drainage system but also increases tidal levels and storm tide levels, which increases the probability and amount of inundation disasters. The serious land subsidence area at Linbian river basin was selected as the study area. An artificial groundwater recharge lake has been set up in Linbian river basin by Pingtung government. The development area of this lake is 58 hectare and the storage volume is 2.1 million cubic meters (210 × 104m3). The surface water from Linbian basin during a wet season is led into the artificial groundwater recharge lake by water diversion project, and then employ special hydro-geological conditions of the area for groundwater recharge, increase groundwater supply and decrease land subsidence rate, and incidentally some of the flood diversion, detention, reduce flooding. In this study, a Real-time Interactive Inundation Model is applied to simulate different flooding storage volume and gate operations to estimate the benefits of flood mitigation. According to the simulation results, the hydrograph shape, peak-flow reduction and time lag to peak of the flood reduction hydrograph into the lake are apparently different for each case of different gate operation at the same storage volume. Therefore, the effect of flood control and disaster mitigation is different. The flood control and disaster mitigation benefits are evaluated by different operation modes, which provide decision makers to

  15. Fault tree analysis for urban flooding

    NARCIS (Netherlands)

    Ten Veldhuis, J.A.E.; Clemens, F.H.L.R.; Van Gelder, P.H.A.J.M.

    2008-01-01

    Traditional methods to evaluate flood risk mostly focus on storm events as the main cause of flooding. Fault tree analysis is a technique that is able to model all potential causes of flooding and to quantify both the overall probability of flooding and the contributions of all causes of flooding to

  16. WATERSHED RUNOFFAND RIVER FLOOD MODELING IN LAND USE PLANNING

    Directory of Open Access Journals (Sweden)

    Marcello Niedda

    2010-06-01

    Full Text Available In land use planning along river paths it may be useful to consider the statistics of the flooding process of the river. The set of rules regulating land use planning in Italy results in the return period required being very long and, as a result, there are very high river discharge peaks which are taken into consideration and not much possibility of making experimental observations. Correct planning of land use should include some description of river flooding in these critical conditions. To do this a basin scale hydrological model and a robust numerical scheme of the 2D complete SWE have to be integrated. Knowing that experimental validation is very difficult we showed the reliability of the numerical schemes used to get consistent solutions. A watershed runoff forecast model was used to obtain the river hydrograph to apply as a boundary condition in the study of river flood inundation on the flat plain near the Olbia airport (Sardinia, Italy. A threshold of 1 cm was used as a condition to consider whether or not to include the cell in the computational field in the description of the wetting-drying process. And this seems to fit well in the model. The numerical model is conservative, ensuring preservation of water volumes with a precision of 10-4. The great surface water gradient in some sections is evident proof of the importance of the SWE inertial terms in wave front propagation. The flow peak loss during the alluvial plane flooding resulted in a reduction of about 10% of the discharge peak at the river mouth. This numerical method, which has been validated in previous similar applications, describes sufficiently well flooding in a complex area with river morphology limited by airport and road infrastructures.

  17. Whillans Ice Plain Stick Slip

    Science.gov (United States)

    Lipovsky, B.; Dunham, E. M.

    2015-12-01

    Concern about future sea level rise motivates the study of fast flowing ice. The Whillans Ice Plain (WIP) region of the West Antarctic Ice Sheet is notable for decelerating from previously fast motion during the instrumental record. Since most ice flux in Antarctica occurs through ice streams, understanding the conditions that cause ice stream stagnation is of basic importance in understanding the continent's contribution to future sea level rise. Although recent progress has been made in understanding the relationship between basal conditions and ice stream motion, direct observation of the temporal variation in subglacial conditions during ice stream stagnation has remained elusive. The Whillans Ice Plain flows to the sea mostly by way of stick-slip motion. We present numerical simulations of this stick-slip motion that capture the inertial dynamics, seismic waves, and the evolution of sliding with rate- and state-dependent basal friction. Large scale stick-slip behavior is tidally modulated and encompasses the entire WIP. Sliding initiates within one of several locked regions and then propagates outward with low average rupture velocity (~ 200 m/s). Sliding accelerates over a period of 200 s attain values as large as 65 m/d. From Newton's second law, this acceleration is ~ T / (rho H) for average shear stress drop T, ice thickness H, and ice density rho. This implies a 3 Pa stress drop that must be reconciled with the final stress drop of 300 Pa inferred from the total slip and fault dimensions. A possible explanation of this apparent discrepancy is that deceleration of the ice is associated with a substantial decrease in traction within rate-strengthening regions of the bed. During these large-scale sliding events, m-scale patches at the bed produce rapid (20 Hz) stick-slip motion. Each small event occurs over ~ 1/100 s, produces ~ 40 microns of slip, and gives rise to a spectacular form of seismic tremor. Variation between successive tremor episodes allows us

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

    Energy Technology Data Exchange (ETDEWEB)

    Spachinger, Karl; Dorner, Wolfgang; Metzka, Rudolf [University of Applied Sciences Deggendorf (Germany); Serrhini, Kamal [Universite de Technologie de Compiegne, Genie des Systemes Urbains, France, and Universite Francois Rabelais, Unite Mixte de Recherche, Tours (France); Fuchs, Sven [Institute of Mountain Risk Engineering, University of Natural Resources and Applied Life Sciences, Vienna (Austria)], E-mail: karl.spachinger@fhd.edu

    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

  19. Buried ancient river by holocene series in Saga Plain; Saga Heiya no kaseki tani

    Energy Technology Data Exchange (ETDEWEB)

    Iwao, Y. [Saga Univ., Saga (Japan). Faculty of Science and Technology; Shimoyama, S. [Kyushu Univ., Fukuoka (Japan). Faculty of Science

    1995-10-01

    Two big faults are supposed to be existed along East West direction of Saga plain and Northern Ariake sea area. Omachi fault originating from the North west part of Saga plain is lying along the east-northeast direction at the center of Saga plain. Further, from the northern direction of Taradake, Yanagawa fault passes along the North east direction. Both of these faults are parallel and between them is the depression ground land called North Ariake graben. Accordingly, weak sedimentary deposit is formed in this depression ground. Activity of Aso pyroclastic flow is observed after the sedimentation along with the sinking of North Ariake graben. It was a regression period and rivers flew into the valley of Ariake with erosion. After that, large amount of volcanic ashes or efflorescence, thickly deposited in the upstream areas of Chikugo river, are carried into the Ariake sea expanded by Jomon transgression. This changes to clay minerals like smectite and so forth, slight regression takes place after the thick sedimentation of Ariake holocene clay and so forth and Saga plain was appeared. 7 refs., 3 figs.

  20. Role of ground water in geomorphology, geology, and paleoclimate of the Southern High Plains, USA.

    Science.gov (United States)

    Wood, Warren W

    2002-01-01

    Study of ground water in the Southern High Plains is central to an understanding of the geomorphology, deposition of economic minerals, and climate change record in the area. Ground water has controlled the course of the Canadian and Pecos rivers that isolated the Southern High Plains from the Great Plains and has contributed significantly to the continuing retreat of the westward escarpment. Evaporative and dissolution processes are responsible for current plateau topography and the development of the signature 20,000 small playa basins and 40 to 50 large saline lake basins in the area. In conjunction with eolian processes, ground water transport controls the mineralogy of commercially valuable mineral deposits and sets up the distribution of fine efflorescent salts that adversely affect water quality. As the water table rises and retreats, lunette and tufa formation provides valuable paleoclimate data for the Southern High Plains. In all these cases, an understanding of ground water processes contributes valuable information to a broad range of geological topics, well beyond traditional interest in water supply and environmental issues.

  1. Application Of Geographic Information Systems Towards Flood Management In Shkodër, Albania

    Directory of Open Access Journals (Sweden)

    Medjon HYSENAJ

    2012-06-01

    Full Text Available The aim of this paper is to show the advantages of GIS in monitoring and improving flood response management in Albania. A full statistic overview of the last flooding occured in the region of Shkodra will be presented. The delicate area balances as far as water management is concerned, have turned into repetitive problematic that have become endemic to the region. The flooding in 2010 and 2011 due to heavy rain, snow melting and hydropower management caused a strong impact in the socio-economic life of the population. According to the last statistics, numbers referring to population displacement, house inundation, property damages seems to be a growing concern for the State Emergency Service. This scenario involves the role of the government institutions in both planning and the operational contexts. Uncoordinated measures between emergency groups, delayed actions from the hydropower specialists, the lack of updated geoinformation followed by a limited remote control occur due to a continuous distant approach created toward GIS technology in our country. As a solution to this scenario it will be presented a concrete platform based on calculations and statistics of dam capacity, allowed water levels, maximum rainfall levels, climate factors, population density and movements. GIS carriesthe potential for flood plain management, flood mapping and forecasting, also population education and awareness. Geospatial information and remote sensing utilization serves as bridge between flooding security measures and damage evaluation. Integration of the population distribution model toward flooding classification which aims the developing of an index mapping is the first step to be initiated. In our case it is important to denote that the usage ofGIS utilities is more effective in the pre-flood than the post-flood phase.

  2. Flood Induced Disasters and Stakeholder Involvement to Implement Integrated Food Management in Nepal

    Science.gov (United States)

    Gautam, N. P.

    2016-12-01

    Nepal, a landlocked country in South Asia covers an area of 147, 181 square kilometers. Its elevation ranges from 61m as the lowest to 8848m, the highest peak Everest in the world. More than 80% of the annual rainfall occurs in the monsoon season from June to September. Thus, due to the intense rainfall that occurs within a short period, monsoon acts as the biggest cause for the occurrence of different disastrous events including flood. Beyond it, Nepal lies at the center and southern edge of Hindu-Kush Himalayan (HKH) region, which is the youngest geological formation in the world. Hence, floods and landslides are common in this region. In Nepal, from the records of 1971-2010, floods and landslides are the second biggest cause for casualties after epidemics. Hawaii based Center of Excellence in disaster management and humanitarian assistance in 2015 has declared Nepal as 30th vulnerable country from the aspect of floods. According to WMO definition, integrated flood management (IFM) is a process of promoting an integrated rather than a fragmented approach to flood management, integrating land and water resource development in a river basin within the context of integrated water resources management (IWRM), with the aim of maximizing the net benefits from flood plains while minimizing loss of life from flooding. That is the reason why the IFM is one of the important countermeasures to be implemented in Nepal to reduce the adverse effects of floods. This study emphasizes on the existing conditions along with the challenges of IFM with respect to stakeholder involvement in the context of Nepal. It can be assured that all the highlighted issues coming out from this study will be highly valuable to policy makers, implementing agencies along with scientific and local communities to enhance IFM works in the nation for the benefits of societies.

  3. Contrasting soils and landscapes of the Piedmont and Coastal Plain, eastern United States

    Science.gov (United States)

    Markewich, H.W.; Pavich, M.J.; Buell, G.R.

    1990-01-01

    sequences that can be correlated along valleys for tens of kilometers. Coastal Plain soils are typically as thick as 2 to 8 m, have high sand content throughout, and have sandy epipedons. These epipedons consist of both A and E horizons and are 1 to 4 m thick. In Coastal Plain soils, the boundaries are transitional between the solum and the underlying parent material and between weathered and unweathered parent material. Infiltration rates for Coastal Plain soils are typically higher at 13-28 cm/h, than are those for Piedmont soils. Indeed, for unconsolidated quartz sand, rates may exceed 50 cm/h. Water moves directly from the soil into the parent material through intergranularpores with only minor channelization along macropores, joints, and fractures. The comparatively high infiltration capacity results in relatively low surface runoff, and correspondingly less erosion than on the Piedmont uplands. Due to differences in Piedmont and Coastal Plain erosion rates, topographic inversion is common along the Fall Zone; surfaces on Cenozoic sedimentary deposits of the Coastal Plain are higher than erosional surfaces on regolith weathered from late Precambrian to early Paleozoic crystalline rocks of the Piedmont. Isotopic, paleontologic, and soil data indicate that Coastal Plain surficial deposits are post-middle Miocene to Holocene in age, but most are from 5 to 2 Ma. Thus, the relatively uneroded surfaces comprise a Pliocene landscape. In the eastern third of the Coastal Plain, deposits that are less than 3.5 Ma include alluvial terraces, marine terraces and barrier/back-barrier complexes as morphostratigraphic units that cover thousands of square kilometers. Isotopic and soil data indicate that eastern Piedmont soils range from late Pliocene to Pleistocene in age, but are predominantly less than 2 Ma old. Thus, the eroded uplands of the Piedmont "peneplain" comprise a Pleistocene landscape. ?? 1990.

  4. Geologic Map of the Santa Barbara Coastal Plain Area, Santa Barbara County, California

    Science.gov (United States)

    Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Gurrola, Larry D.; Keller, Edward A.; Brandt, Theodore R.

    2009-01-01

    This report presents a newly revised and expanded digital geologic map of the Santa Barbara coastal plain area at a compilation scale of 1:24,000 (one inch on the map to 2,000 feet on the ground)1 and with a horizontal positional accuracy of at least 20 m. The map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying and adjacent to the coastal plain within the contiguous Dos Pueblos Canyon, Goleta, Santa Barbara, and Carpinteria 7.5' quadrangles. The new map supersedes an earlier preliminary geologic map of the central part of the coastal plain (Minor and others, 2002; revised 2006) that provided coastal coverage only within the Goleta and Santa Barbara quadrangles. In addition to new mapping to the west and east, geologic mapping in parts of the central map area has been significantly revised from the preliminary map compilation - especially north of downtown Santa Barbara in the Mission Ridge area - based on new structural interpretations supplemented by new biostratigraphic data. All surficial and bedrock map units, including several new units recognized in the areas of expanded mapping, are described in detail in the accompanying pamphlet. Abundant new biostratigraphic and biochronologic data based on microfossil identifications are presented in expanded unit descriptions of the marine Neogene Monterey and Sisquoc Formations. Site-specific fault kinematic observations embedded in the digital map database are more complete owing to the addition of slip-sense determinations. Finally, the pamphlet accompanying the present report includes an expanded and refined summary of stratigraphic and structural observations and interpretations that are based on the composite geologic data contained in the new map compilation. The Santa Barbara coastal plain is located in the western Transverse Ranges physiographic province along an east-west-trending segment of the southern California coastline about 100 km (62 mi) northwest

  5. Southern Great Plains Atmospheric Radiation Measurement Site

    Data.gov (United States)

    Federal Laboratory Consortium — The Southern Great Plains Atmospheric Radiation Measurement Site (SGP-ARM) is the oldest and largest of DOE's Arm sites. It was established in 1992. It consists of...

  6. PLAINS CO2 REDUCTION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; John A. Harju; Erin M. O' Leary; James A. Sorensen; Daniel J. Daly; Melanie D. Jensen; Lisa S. Botnen

    2005-07-01

    The Plains CO{sub 2} Reduction (PCOR) Partnership characterization work is nearing completion, and most remaining efforts are related to finalizing work products. Task 2 (Technology Deployment) has developed a Topical Report entitled ''Deployment Issues Related to Geologic CO{sub 2} Sequestration in the PCOR Partnership Region''. Task 3 (Public Outreach) has developed an informational Public Television program entitled ''Nature in the Balance'', about CO{sub 2} sequestration. The program was completed and aired on Prairie Public Television in this quarter. Task 4 (Sources, Sinks, and Infrastructure) efforts are nearing completion, and data regarding CO{sub 2} sources and sinks and data on the performance and costs for CO{sub 2} separation, capture, treatment, and compression for pipeline transportation are being incorporated into a series of topical reports. The expansion of the Decision Support System Geographic Information System database has continued with the development of a ''save bookmark'' feature that allows users to save a map from the system easily. A feature that allows users to develop a report that summarizes CO{sub 2} sequestration parameters was also developed. Task 5 (Modeling and Phase II Action Plans) focused on screening and qualitatively assessing sequestration options and developing economic estimates for important regional CO{sub 2} sequestration strategies.

  7. PLAINS CO2 REDUCTION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; John A. Harju; Erin M. O' Leary; James A. Sorensen; Daniel J. Daly; Melanie D. Jensen; Thea E. Reikoff

    2005-04-01

    The Plains CO{sub 2} Reduction (PCOR) Partnership continues to make great progress. Task 2 (Technology Deployment) focused on developing information regarding deployment issues to support Task 5 (Modeling and Phase II Action Plans) and provided information to be used to assess CO{sub 2} sequestration opportunities in the PCOR Partnership region. Task 2 efforts also included preparation of a draft topical report entitled ''Deployment Issues Related to Geologic CO{sub 2} Sequestration in the PCOR Partnership Region'', which is nearing completion. Task 3 (Public Outreach) focused on developing an informational video about CO{sub 2} sequestration. The video will be completed and aired on Prairie Public Television in the next quarter. Progress in Task 4 (Sources, Sinks, and Infrastructure) included the continued collection of data regarding CO{sub 2} sources and sinks and data on the performance and costs for CO{sub 2} separation, capture, treatment, and compression for pipeline transportation. The addition of the Canadian province of Alberta to the PCOR Partnership region expanded the decision support system (DSS) geographic information system database. Task 5 screened and qualitatively assessed sequestration options. Task 5 activities also continue to be useful in structuring data collection and other activities in Tasks 2, 3, and 5.

  8. 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.;

  9. Spatial Analysis in Determination Of Flood Prone Areas Using Geographic Information System and Analytical Hierarchy Process at Sungai Sembrong's Catchment

    Science.gov (United States)

    Bukari, S. M.; Ahmad, M. A.; Wai, T. L.; Kaamin, M.; Alimin, N.

    2016-07-01

    Floods that struck Johor state in 2006 and 2007 and the East Coastal in 2014 have triggered a greatly impact to the flood management here in Malaysia. Accordingly, this study conducted to determine potential areas of flooding, especially in Batu Pahat district since it faces terrifying experienced with heavy flood. This objective is archived by using the application of Geographic Information Systems (GIS) on study area of flood risk location at the watershed area of Sungai Sembrong. GIS functions as spatial analysis is capable to produce new information based on analysis of data stored in the system. Meanwhile the Analytical Hierarchy Process (AHP) was used as a method for setting up in decision making concerning the existing data. By using AHP method, preparation and position of the criteria and parameters required in GIS are neater and easier to analyze. Through this study, a flood prone area in the watershed of Sungai Sembrong was identified with the help of GIS and AHP. Analysis was conducted to test two different cell sizes, which are 30 and 5. The analysis of flood prone areas were tested on both cell sizes with two different water levels and the results of the analysis were displayed by GIS. Therefore, the use of AHP and GIS are effective and able to determine the potential flood plain areas in the watershed area of Sungai Sembrong.

  10. Magnetostratigraphic and paleoclimatic studies on the Red Earth Formation from the Chengdu Plain in Sichuan Province, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO ZhiZhong; QIAO YanSong; WANG Yan; FU JianLi; WANG ShuBing; LI ChaoZhu; YAO HaiTao; JIANG FuChu

    2007-01-01

    Two red earth sections from the Chengdu Plain in Sichuan Province are dated using geomagnetic methods. The Brunhes/Matuyama (B/M) reversal boundary is recognized within the upper parts of the two sections, and the Jaramillo normal subzone occurs in the middle-lower parts of the vermiculated red soil (VRS), which indicate that the parent material for the VRS deposited in the middle Quaternary.Sedimentologic and geochemical studies suggest that the Chengdu Clay and part of the parent material for the VRS are of aeolian origin. Pollen analysis indicates that the Chengdu Plain was mainly covered by needle-leaved forest with a cool to cool temperate humid climate when the parent material for the VRS deposited. The relatively cool to cool temperate climatic condition in the Chengdu Plain in the middle Quaternary, which may be caused by the uplift of the Tibetan Plateau, was a response to the geo-environmental changes of global significance.

  11. Magnetostratigraphic and paleoclimatic studies on the Red Earth Formation from the Chengdu Plain in Sichuan Province,China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Two red earth sections from the Chengdu Plain in Sichuan Province are dated using geomagnetic methods. The Brunhes/Matuyama (B/M) reversal boundary is recognized within the upper parts of the two sections,and the Jaramillo normal subzone occurs in the middle-lower parts of the vermiculated red soil (VRS),which indicate that the parent material for the VRS deposited in the middle Quaternary. Sedimentologic and geochemical studies suggest that the Chengdu Clay and part of the parent material for the VRS are of aeolian origin. Pollen analysis indicates that the Chengdu Plain was mainly covered by needle-leaved forest with a cool to cool temperate humid climate when the parent material for the VRS deposited. The relatively cool to cool temperate climatic condition in the Chengdu Plain in the middle Quaternary,which may be caused by the uplift of the Tibetan Plateau,was a response to the geo-environmental changes of global significance.

  12. A new GIS approach for reconstructing and mapping dynamic late Holocene coastal plain palaeogeography

    Science.gov (United States)

    Pierik, H. J.; Cohen, K. M.; Stouthamer, E.

    2016-10-01

    The geomorphological development of Holocene coastal plains around the world has been studied since the beginning of the twentieth century from various disciplines, resulting in large amounts of data. However, the overwhelming quantities and heterogeneous nature of this data have caused the divided knowledge to remain inconsistent and fragmented. To keep improving the understanding of coastal plain geomorphology and geology, cataloguing of data and integration of knowledge are essential. In this paper we present a GIS that incorporates the accumulated data of the Netherlands' coastal plain and functions as a storage and integration tool for coastal plain mapped data. The GIS stores redigitised architectural elements (beach barriers, tidal channels, intertidal flats, supratidal flats, and coastal fresh water peat) from earlier mappings in separate map layers. A coupled catalogue-style database stores the dating information of these elements, besides references to source studies and annotations regarding changed insights. Using scripts, the system automatically establishes palaeogeographical maps for any chosen moment, combining the above mapping and dating information. In our approach, we strip the information to architectural element level, and we separate mapping from dating information, serving the automatic generation of time slice maps. It enables a workflow in which the maker can iteratively regenerate maps, which speeds up fine-tuning and thus the quality of palaeogeographical reconstruction. The GIS currently covers the late Holocene coastal plain development of the Netherlands. This period witnessed widespread renewed flooding along the southern North Sea coast, coinciding with large-scale reclamation and human occupation. Our GIS method is generic and can be expanded and adapted to allow faster integrated processing of growing amounts of data for many coastal areas and other large urbanising lowlands around the world. It allows maintaining actual data

  13. Probabilistic Flood Defence Assessment Tools

    Directory of Open Access Journals (Sweden)

    Slomp Robert

    2016-01-01

    Full Text Available The WTI2017 project is responsible for the development of flood defence assessment tools for the 3600 km of Dutch primary flood defences, dikes/levees, dunes and hydraulic structures. These tools are necessary, as per January 1st 2017, the new flood risk management policy for the Netherlands will be implemented. Then, the seven decades old design practice (maximum water level methodology of 1958 and two decades old safety standards (and maximum hydraulic load methodology of 1996 will formally be replaced by a more risked based approach for the national policy in flood risk management. The formal flood defence assessment is an important part of this new policy, especially for flood defence managers, since national and regional funding for reinforcement is based on this assessment. This new flood defence policy is based on a maximum allowable probability of flooding. For this, a maximum acceptable individual risk was determined at 1/100 000 per year, this is the probability of life loss of for every protected area in the Netherlands. Safety standards of flood defences were then determined based on this acceptable individual risk. The results were adjusted based on information from cost -benefit analysis, societal risk and large scale societal disruption due to the failure of critical infrastructure e.g. power stations. The resulting riskbased flood defence safety standards range from a 300 to a 100 000 year return period for failure. Two policy studies, WV21 (Safety from floods in the 21st century and VNK-2 (the National Flood Risk in 2010 provided the essential information to determine the new risk based safety standards for flood defences. The WTI2017 project will provide the safety assessment tools based on these new standards and is thus an essential element for the implementation of this policy change. A major issue to be tackled was the development of user-friendly tools, as the new assessment is to be carried out by personnel of the

  14. Temporal clustering of floods in Germany: Do flood-rich and flood-poor periods exist?

    Science.gov (United States)

    Merz, Bruno; Nguyen, Viet Dung; Vorogushyn, Sergiy

    2016-10-01

    The repeated occurrence of exceptional floods within a few years, such as the Rhine floods in 1993 and 1995 and the Elbe and Danube floods in 2002 and 2013, suggests that floods in Central Europe may be organized in flood-rich and flood-poor periods. This hypothesis is studied by testing the significance of temporal clustering in flood occurrence (peak-over-threshold) time series for 68 catchments across Germany for the period 1932-2005. To assess the robustness of the results, different methods are used: Firstly, the index of dispersion, which quantifies the departure from a homogeneous Poisson process, is investigated. Further, the time-variation of the flood occurrence rate is derived by non-parametric kernel implementation and the significance of clustering is evaluated via parametric and non-parametric tests. Although the methods give consistent overall results, the specific results differ considerably. Hence, we recommend applying different methods when investigating flood clustering. For flood estimation and risk management, it is of relevance to understand whether clustering changes with flood severity and time scale. To this end, clustering is assessed for different thresholds and time scales. It is found that the majority of catchments show temporal clustering at the 5% significance level for low thresholds and time scales of one to a few years. However, clustering decreases substantially with increasing threshold and time scale. We hypothesize that flood clustering in Germany is mainly caused by catchment memory effects along with intra- to inter-annual climate variability, and that decadal climate variability plays a minor role.

  15. Towards Interactive Flood Governance: changing approaches in Dutch flood policy

    NARCIS (Netherlands)

    J.A. van Ast (Jacko)

    2013-01-01

    markdownabstract__Abstract__ In the course of history, flooding of rivers and the sea brought misery to humanity. Low lying delta’s of large rivers like Bangladesh, New Orleans, the Nile delta or the Netherlands belong to the most vulnerable for flood disasters. Since ancient times people pondered

  16. FLOOD AND FLOOD CONTROL OF THE YELLOW RIVER

    Institute of Scientific and Technical Information of China (English)

    Wenxue LI; Huirang WANG; Yunqi SU; Naiqian JIANG; Yuanfeng ZHANG

    2002-01-01

    The Yellow River is the cradle of China. It had long been the center of politics, economics and culture of China in history. Large coverage flood disaster occurred frequently in the Yellow River basin and the losses were often heavy. Thus, the Yellow River is also considered as the serious hidden danger of China. Since the founding of new China, structural and non-structural systems of flood control have been established basically. Tremendous successes have been made on flood control. Into the 21century, flood control standard of the Lower Yellow River has been increased significantly with the operation of the Xiaolangdi Reservoir. However, problems of the Yellow River are complicated and the tasks for solving these problems are arduous. Particularly, the sedimentation problem can't be solved completely in the near future. The situation of "suspended river" and threat of flood will long exist.Therefore, supported by rapid social and economical development of the nation and relied on advanced technology, the flood control system shall be perfected. Meantime, study of the Yellow River shall be enhanced in order to better understand the flood, get with it and use it thus to reduce flood disaster.

  17. Storage and flood routing

    Science.gov (United States)

    Carter, R.W.; Godfrey, R.G.

    1960-01-01

    The basic equations used in flood routing are developed from the law of continuity. In each method the assumptions are discussed to enable the user to select an appropriate technique. In the stage-storage method the storage is related to the mean gage height in the reach under consideration. In the discharge-storage method the storage is determined, from weighted values of inflow and outflow discharge. In the reservoir-storage method the storage is considered as a function of outflow discharge alone. A detailed example is given for each method to illustrate that particular technique.

  18. Flood Insurance Rate Maps and Base Flood Elevations, FIRM, DFIRM, BFE - MO 2014 Springfield FEMA Base Flood Elevations (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — This polyline layer indicates the approximate effective FEMA Base Flood Elevation (BFE) associated with the corresponding Special Flood Hazard Area (SFHA). Each line...

  19. Flood Insurance Rate Maps and Base Flood Elevations, FIRM, DFIRM, BFE - MO 2010 Springfield FEMA Base Flood Elevations (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This polyline layer indicates the approximate effective FEMA Base Flood Elevations (BFE) associated with the corresponding Special Flood Hazard Area (SFHA). Each...

  20. Estancia Special Flood Hazard Areas (SFHA)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This vector dataset depicts the 1% annual flood boundary (otherwise known as special flood hazard area or 100 year flood boundary) for its specified area. The data...

  1. Elephant Butte Special Flood Hazard Areas (SFHA)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This vector dataset depicts the 1% annual flood boundary (otherwise known as special flood hazard area or 100 year flood boundary) for its specified area. The data...

  2. Sierra County Special Flood Hazard Areas (SFHA)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This vector dataset depicts the 1% annual flood boundary (otherwise known as special flood hazard area or 100 year flood boundary) for its specified area. The data...

  3. Governmental policies drive the LUCC trajectories in the Jianghan Plain.

    Science.gov (United States)

    Wang, Hongzhi; Shao, Qihui; Li, Rendong; Song, Mingjie; Zhou, Yong

    2013-12-01

    The prosperity of farmers is closely tied to governmental policies. The Jianghan Plain is an important region for commodity grains, cotton and edible oil for China. The trajectories of land use and land cover change (LUCC) of the study area from 1995 to 2010 were studied based on the LUCC database of the Chinese Academy of Sciences. The LUCC was characterised by a continuous decrease of arable land and continuous increase of waters and construction land. The LUCC was obviously concurrent with the implementation of related national policies. The transition to construction land was ever well controlled by 'Notice regarding the further strengthening of land management and arable land protection' promulgated in 1997. However, it flourished again with the 'Rise of Central China Strategy' taking effect since 2006. The transition of construction land to others reflects an uncommon trend, which must be strengthened with the strict implementation of the overall plan, which imposes a limited acreage quota of construction land to each district. The policies were quite contradictory to the transition of waters. LUCC related to waters is most active, which was driven by both natural forces and national policies. Just after the devastating flood of 1998, the state council of China put forward the Green Policy to govern the major rivers. As to the study area, it is mainly to 'push over dykes to let flood through and return farmland to lakes'. In 2004, the Grain Direct Subsidy Policy was implemented, which, along with the surge in the price of rice, resulted in a strengthening trend of conversion of ponds to paddy fields.

  4. Crustal thickness and composition beneath the High Lava Plains of Eastern Oregon from teleseismic receiver functions

    Science.gov (United States)

    Eagar, K. C.; Fouch, M. J.; James, D. E.; Carlson, R. W.

    2009-12-01

    The nature of the crust beneath the High Lava Plains of eastern Oregon is fundamental for understanding the origins of widespread Cenozoic volcanism in the region. Eruptions of flood basalts in the southern Cascadian back arc peaked ~17-15 Ma, and were followed by distributed bimodal volcanism along two perpendicular migrating tracks; the Snake River Plain and the High Lava Plains. The orientations of eruptive centers have led to several competing hypotheses about their cause, including a deep mantle plume, slab retreat and asthenospheric inflow, lithospheric delamination, and lithospheric extension. The goal of this project is to constrain the nature, geometry, and depth of the Moho across the High Lava Plains, which will shed light on questions regarding crustal influence on melt generation and differentiation and the degree of magmatic underplating. In this study, we analyze teleseismic receiver functions from 118 stations of the High Lava Plains temporary broadband array, 34 nearby EarthScope/USArray stations, and 5 other regional broadband stations to determine bulk crustal features of thickness (H) and Vp/Vs ratio (κ). Applying the H-κ stacking method, we search for the best-fitting solution of timing predictions for direct and multiple P-to-S conversions from the Moho interface. Converting Vp/Vs to Poisson ratio, which is dependent primarily upon rock composition, allows for comparison with other direct geological observations. Preliminary results show that the crust of the High Lava Plains is relatively thin (~31 km) with a very sharp gradient to thicker crust (~42 km) at the western edge of the Owyhee Plateau in southwestern Idaho. This gradient is co-located with the western margin of Precambrian North America and is in the vicinity of the Jordan Craters volcanic center. The sharp topography of the Moho might have been a factor in melt migration beneath this area. West of the High Lava Plains, the crust thickens to ~40 km into the Cascade volcanic arc

  5. The Aqueduct Global Flood Analyzer

    Science.gov (United States)

    Iceland, Charles

    2015-04-01

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

  6. Probable recent water/lava source fissures in the Cerberus Plains: stratigraphic and crater count age constraints

    Science.gov (United States)

    Thomas, R.

    2012-09-01

    The Cerberus Plains have received increasing attention in recent years due to evidence from highresolution imagery that they are some of the youngest surfaces on Mars. The plains are incised by large outflow channels, possibly as recently as 20Ma in the case of Athabasca Valles [2]. These channels are generally thought to be water-carved [1,3], though it is possible they were incised by turbulent lava [8]. As recently as 10Ma or less [5] both the channels and the plains around them are proposed to have been draped with lava [7]. Thus the recent activity forming the Cerberus Plains probably required large volumes of both water and lava. The problem which arises is a source. Cerberus Fossae have been suggested as the source of the Athabasca Valles outflows [3,6], but topographic and stratigraphic issues have arisen which make this unlikely: for example, a streamlined island spans the fossa where water and/or lava is said to have originated [4]. No other specific sources have been identified. As plains volcanism often obscures its fissures, sources should be searched for in features elevated above the plain. New HiRISE images have shown just such a feature: a wrinkle ridge south of Cerberus Fossae incised by a series of fissures. Every fissure has associated channels and deposits indicating outflow onto the plains surrounding the ridge. Until now, the stratigraphic history of these features was poorly known, with Tanaka et al.'s [9] geological map considering the area only on the broadest scale. This study produces small-scale geomorphological maps to establish the stratigraphic relationships between the fissure-sourced outflows and the plains surrounding the ridge to test the hypothesis that they were the source of the plains material. Crater counting is also conducted to supplement stratigraphic observations and give tentative ages.

  7. Flood Risk, Flood Mitigation, and Location Choice: Evaluating the National Flood Insurance Program's Community Rating System.

    Science.gov (United States)

    Fan, Qin; Davlasheridze, Meri

    2016-06-01

    Climate change is expected to worsen the negative effects of natural disasters like floods. The negative impacts, however, can be mitigated by individuals' adjustments through migration and relocation behaviors. Previous literature has identified flood risk as one significant driver in relocation decisions, but no prior study examines the effect of the National Flood Insurance Program's voluntary program-the Community Rating System (CRS)-on residential location choice. This article fills this gap and tests the hypothesis that flood risk and the CRS-creditable flood control activities affect residential location choices. We employ a two-stage sorting model to empirically estimate the effects. In the first stage, individuals' risk perception and preference heterogeneity for the CRS activities are considered, while mean effects of flood risk and the CRS activities are estimated in the second stage. We then estimate heterogeneous marginal willingness to pay (WTP) for the CRS activities by category. Results show that age, ethnicity and race, educational attainment, and prior exposure to risk explain risk perception. We find significant values for the CRS-creditable mitigation activities, which provides empirical evidence for the benefits associated with the program. The marginal WTP for an additional credit point earned for public information activities, including hazard disclosure, is found to be the highest. Results also suggest that water amenities dominate flood risk. Thus, high amenity values may increase exposure to flood risk, and flood mitigation projects should be strategized in coastal regions accordingly.

  8. Urban floods: a case study in the Savigliano area (North-Western Italy

    Directory of Open Access Journals (Sweden)

    C. Audisio

    2011-11-01

    Full Text Available Flood processes and effects are examined, concerning two rivers in an urbanized area in North-Western Italy (Piedmont – Cuneo Plain. In May 2008, some areas in Northern Italy were struck by intense and persistent rainfall. In the Cuneo province (Southern Piedmont, floodplain with some urban areas was inundated over ca. ten square kilometres, and the city of Savigliano (about 21 000 inhabitants was particularly hit by flood. A purposely-made historical research has evidenced approximately fifty flood events as having occurred since 1350 in the Savigliano area. Based upon historical data, both documents and maps, GIS (Geographical Information System technique and field surveys were used to quantitatively assess the growing urbanization of the city and to describe flood processes and effects over years. This work aims to describe the dynamic behaviour of the 2008 flood, also comparing it to past events, in particular those that occurred in 1896. It is emphasized how the knowledge of past events can be helpful in reducing urban flooding.

  9. Subsidence and Deforestation: Implications for Flooding in Delta’s Southeast and East Asia

    Directory of Open Access Journals (Sweden)

    . Nurhamidah

    2011-01-01

    Full Text Available Delta is a low-lying area which can be found at the mouth of a river. Nowadays, concentration of flooding occurs in many deltaic areas due to combination of several factors. Meanwhile, a big number of people live on flood plain of main rivers and river deltas which will be threatened by flooding.  Land subsidence and deforestation are two phenomena which had been occurring very high until recently in SEE Asia region. Increasing of population strongly influences the natural hydrological processes. Due to pressure for land, substantial areas of peat swamps in SEE Asia have been presently are being reclaimed for agriculture or for other land use. In natural conditions swamp areas functioned as a retention area by adsorbing flood water, thereby preventing or mitigation flooding in downstream areas. But unfortunately, large areas of the original forests in large peat swamp forests have disappeared due to human activities such as illegal logging and fires. In other side increasing population, industries, agricultures and plantations will increase water demand. Activities of ground water extraction will be increasing as well. It can cause land subsidence and furthermore tide can easily propagate into deltaic areas moreover compounded by lowering of land surface due to land subsidence. Since flooding is an issue has been identified then these two phenomena need to be identified as well.

  10. Water NOT wanted - Coastal Floods and Flooding Protection in Denmark

    DEFF Research Database (Denmark)

    Sørensen, Carlo Sass

    2016-01-01

    vulnerability towards coastal flooding, the country has experienced severe storm surges throughout history, and hitherto safe areas will become increasingly at risk this century as the climate changes. Historically a seafarers’ nation, Denmark has always been connected with the sea. From medieval time ports...... acceptance of floods has decreased from a “this is a natural consequence of living by the sea” to an explicit: Water Not Wanted! This paper provides a brief overview of floods and flooding protection issues in Denmark (Ch. 2 & Ch. 3), the current legislation (Ch. 4), and discusses challenges in relation...... to climate change adaptation, risk reduction, and to potential ways of rethinking flooding protection in strategies that also incorporate other uses (Ch. 5)....

  11. How Unique was Hurricane Sandy? Sedimentary Reconstructions of Extreme Flooding from New York Harbor

    Science.gov (United States)

    Brandon, Christine M.; Woodruff, Jonathan D.; Donnelly, Jeffrey P.; Sullivan, Richard M.

    2014-12-01

    The magnitude of flooding in New York City by Hurricane Sandy is commonly believed to be extremely rare, with estimated return periods near or greater than 1000 years. However, the brevity of tide gauge records result in significant uncertainties when estimating the uniqueness of such an event. Here we compare resultant deposition by Hurricane Sandy to earlier storm-induced flood layers in order to extend records of flooding to the city beyond the instrumental dataset. Inversely modeled storm conditions from grain size trends show that a more compact yet more intense hurricane in 1821 CE probably resulted in a similar storm tide and a significantly larger storm surge. Our results indicate the occurrence of additional flood events like Hurricane Sandy in recent centuries, and highlight the inadequacies of the instrumental record in estimating current flood risk by such extreme events.

  12. Flood damage in Italy: towards an assessment model of reconstruction costs

    Science.gov (United States)

    Sterlacchini, Simone; Zazzeri, Marco; Genovese, Elisabetta; Modica, Marco; Zoboli, Roberto

    2016-04-01

    Recent decades in Italy have seen a very rapid expansion of urbanisation in terms of physical assets, while demographics have remained stable. Both the characteristics of Italian soil and anthropic development, along with repeated global climatic stress, have made the country vulnerable to floods, the intensity of which is increasingly alarming. The combination of these trends will contribute to large financial losses due to property damage in the absence of specific mitigation strategies. The present study focuses on the province of Sondrio in Northern Italy (area of about 3,200 km²), which is home to more than 180,000 inhabitants and the population is growing slightly. It is clearly a hot spot for flood exposure, as it is primarily a mountainous area where floods and flash floods hit frequently. The model we use for assessing potential flood damage determines risk scenarios by overlaying flood hazard maps and economic asset data. In Italy, hazard maps are provided by Regional Authorities through the Hydrogeological System Management Plan (PAI) based on EU Flood Directive guidelines. The PAI in the study area includes both the large plain and the secondary river system and considers three hazard scenarios of Low, Medium and High Frequency associated with return periods of 20, 200 and 500 years and related water levels. By an overlay of PAI maps and residential areas, visualized on a GIS, we determine which existing built-up areas are at risk for flood according to each scenario. Then we investigate the value of physical assets potentially affected by floods in terms of market values, using the database of the Italian Property Market Observatory (OMI), and in terms of reconstruction costs, by considering synthetic cost indexes of predominant building types (from census information) and PAI water height. This study illustrates a methodology to assess flood damage in urban settlements and aims to determine general guidelines that can be extended throughout Italy

  13. FLOOD ROUTING MODELS IN CONFLUENT AND DIVIDING CHANNELS

    Institute of Scientific and Technical Information of China (English)

    范平; 李家春; 刘青泉

    2004-01-01

    By introducing a water depth connecting formula, the hydraulic equations in the dividing channel system were coupled and the relation of discharge distribution between the branches of the dividing channels can be yielded. In this manner, a numerical model for the confluent channels was established to study the variation of backwater effects with the parameters in the channel junction. The meeting of flood peaks in the mainstream and tributary can be analyzed with this model. The flood peak meeting is found to be a major factor for the extremely high water level in the mainstream during the 1998 Yangtze River flood. Subsequently the variations of discharge distribution and water level with channel parameters between each branch in this system were studied as well. As a result, flood evolution caused by Jingjiang River shortcut and sediment deposition in the entrance of dividing channels of the Yangtze River may be qualitatively elucidated. It is suggested to be an effective measure for flood mitigation to enhance regulation capability of reservoirs available upstream of the tributaries and harness branch entrance channels.

  14. Plateaus and sinuous ridges as the fingerprints of lava flow inflation in the Eastern Tharsis Plains of Mars

    Science.gov (United States)

    Bleacher, Jacob E.; Orr, Tim; de Wet, Andrew P.; Zimbelman, James R.; Hamilton, Christopher W.; Garry, W. Brent; Crumpler, Larry S.; Williams, David A.

    2017-01-01

    The Tharsis Montes rift aprons are composed of outpourings of lava from chaotic terrains to the northeast and southwest flank of each volcano. Sinuous and branching channel networks that are present on the rift aprons suggest the possibility of fluvial processes in their development, or erosion by rapidly emplaced lavas, but the style of lava flow emplacement throughout rift apron development is not clearly understood. To better characterize the style of lava emplacement and role of fluvial processes in rift apron development, we conducted morphological mapping of the Pavonis Mons southwest rift apron and the eastern Tharsis plains using images from the High Resolution Imaging Science Experiment (HiRISE), Mars Orbiter Camera (MOC), Context Camera (CTX), Thermal Emission Imaging System (THEMIS), and High Resolution Stereo Camera (HRSC) along with the Mars Orbiter Laser Altimeter (MOLA) Precision Experiment Data Records (PEDRs) and gridded data. Our approach was to: (1) search for depositional fans at the slope break between the rift apron and adjacent low slope plains; (2) determine if there is evidence that previously formed deposits might have been buried by plains units; (3) characterize the Tharsis plains morphologies east of Pavonis Mons; and (4) assess their relationship to the rift apron units. We have not identified topographically significant depositional fans, nor did we observe evidence to suggest that plains units have buried older rift apron units. Flow features associated with the rift apron are observed to continue across the slope break onto the plains. In this area, the plains are composed of a variety of small fissures and low shield vents around which broad channel-fed and tube-fed flows have been identified. We also find broad, flat-topped plateaus and sinuous ridges mixed among the channels, tubes and vents. Flat-topped plateaus and sinuous ridges are morphologies that are analogous to those observed on the coastal plain of Hawai‘i, where lava

  15. Properties of basin-fill deposits, a 1971–2000 water budget, and surface-water-groundwater interactions in the upper Humboldt River basin, northeastern Nevada

    Science.gov (United States)

    Plume, Russell W.; Smith, Jody L.

    2013-01-01

    This study was done in cooperation with Elko County, Nevada in response to concerns over growing demand for water within the county and increasing external demands that are occurring statewide. The upper Humboldt River basin encompasses 4,360 square miles in northeastern Nevada and includes the headwaters area of the Humboldt River. Nearly all of the mean annual flow of the Humboldt River originates in this area. Basin-fill deposits function as the principal aquifers in the upper Humboldt River basin. Over much of the basin lowlands, the upper 200 feet of basin fill consists of clay, silt, sand, and gravel deposited in a lake of middle to late Pliocene age. Fine-grained lacustrine sediments compose from 30 to more than 70 percent of the deposits. Mean values of transmissivity are less than 1,000 feet squared per day. Total inflow to the upper Humboldt River basin, about 3,330,000 acre-feet per year, is entirely from annual precipitation. Total outflow from the basin, about 3,330,000 acre-feet per year, occurs as evapotranspiration, streamflow, subsurface flow, and pumpage. The uncertainty of these values of inflow and outflow is estimated to be 25 percent. Baseflow of the Humboldt River is minimal upstream of the Elko Hills and in downstream reaches almost all baseflow comes from tributary inflow of the North Fork and South Fork Humboldt Rivers. However, the baseflow of these two tributaries comes from groundwater discharge to their respective channels in canyons incised in volcanic rocks along the North Fork and in carbonate rocks along the South Fork. Water levels in the shallow water-table aquifer along the Humboldt River flood plain fluctuate with changes in stage of the river. During high rising river stage in spring and early summer, streamflow enters the aquifer as bank storage. As stage begins to decline in early to mid-summer groundwater in bank storage begins discharging back into the river channel and this continues through late summer. In years of below