Science.gov

Sample records for flood control reservoir

  1. Intelligent Real-Time Reservoir Operation for Flood Control

    NASA Astrophysics Data System (ADS)

    Chang, L.; Hsu, H.

    2008-12-01

    Real-time flood control of a multi-purpose reservoir should consider decreasing the flood peak stage downstream and storing floodwaters for future usage during typhoon seasons. It is a continuous and instant decision-making process based on relevant operating rules, policy and water laws, in addition the immediate rainfall and the hydrology information; however, it is difficult to learn the intelligent experience from the elder operators. The main purpose of this study is to establish the automatic reservoir flood control model to achieve the goal of a reservoir operation during flood periods. In this study, we propose an intelligent reservoir operating methodology for real-time flood control. First, the genetic algorithm is used to search the optimal solutions, which can be considered as extracting the knowledge of reservoir operation strategies. Then, the adaptive network-based fuzzy inference system (ANFIS), which uses a hybrid learning procedure for extracting knowledge in the form of fuzzy if-then rules, is used to learn the input-output patterns and then to estimate the optimal flood operation. The Shihmen reservoir in Northern Taiwan was used as a case study, where its 26 typhoon events are investigated by the proposed method. The results demonstrate that the proposed control model can perform much better than the original reservoir operator in 26 flood events and effectively achieve decreasing peak flood stage downstream and storing floodwaters for future usage.

  2. Assessing sedimentation issues within aging of flood-control reservoirs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flood control reservoirs designed and built by federal agencies have been extremely effective in reducing the ravages of floods nationwide. Yet some structures are being removed for a variety of reasons, while other structures are aging rapidly and require either rehabilitation or decommissioning. ...

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  4. Water levels shape fishing participation in flood-control reservoirs

    USGS Publications Warehouse

    Miranda, Leandro E.; Meals, K. O.

    2013-01-01

    We examined the relationship between fishing effort (hours fished) and average March–May water level in 3 flood control reservoirs in Mississippi. Fishing effort increased as water level rose, peaked at intermediate water levels, and decreased at high water levels. We suggest that the observed arched-shaped relationship is driven by the shifting influence of fishability (adequacy of the fishing circumstances from an angler's perspective) and catch rate along a water level continuum. Fishability reduces fishing effort during low water, despite the potential for higher catch rates. Conversely, reduced catch rates and fishability at high water also curtail effort. Thus, both high and low water levels seem to discourage fishing effort, whereas anglers seem to favor intermediate water levels. Our results have implications for water level management in reservoirs with large water level fluctuations.

  5. Joint operation and dynamic control of flood limiting water levels for mixed cascade reservoir systems

    NASA Astrophysics Data System (ADS)

    Zhou, Yanlai; Guo, Shenglian; Liu, Pan; Xu, Chongyu

    2014-11-01

    Reservoirs are one of the most efficient infrastructures for integrated water resources development and management; and play a more and more important role in flood control and conservation. Dynamic control of the reservoir flood limiting water level (FLWL) is a valuable and effective approach to compromise the flood control, hydropower generation and comprehensive utilization of water resources of river basins during the flood season. The dynamic control models of FLWL for a single reservoir and cascade reservoirs have been extended for a mixed reservoir system in this paper. The proposed model consists of a dynamic control operation module for a single reservoir, a dynamic control operation module for cascade reservoirs, and a joint operation module for mixed cascade reservoir systems. The Three Gorges and Qingjiang cascade reservoirs in the Yangtze River basin of China are selected for a case study. Three-hour inflow data series for representative hydrological years are used to test the model. The results indicate that the proposed model can make an effective tradeoff between flood control and hydropower generation. Joint operation and dynamic control of FLWL can generate 26.4 × 108 kW h (3.47%) more hydropower for the mixed cascade reservoir systems and increase the water resource utilization rate by 3.72% for the Three Gorges reservoir and 2.42% for the Qingjiang cascade reservoirs without reducing originally designed flood prevention standards.

  6. Optimized cascade reservoir operation considering ice flood control and power generation

    NASA Astrophysics Data System (ADS)

    Chang, Jianxia; Meng, Xuejiao; Wang, ZongZhi; Wang, Xuebin; Huang, Qiang

    2014-11-01

    Ice flood control is an important objective for reservoir operation in cold regions. Maintaining the reservoir outflow in a certain range is considered an effective way to remediate ice flood damage. However, this strategy may decrease the socio-economic benefit of reservoirs, for example, reduction of hydropower production. These conflicting objectives cause a dilemma for water managers when defining reservoir operation policy. This study considers seven cascade reservoirs in the upstream Yellow River, and ice flood control storage is introduced to balance the hydropower generation and ice flood control. The relation between the ice flood control storage volume of the Liujiaxia reservoir and cascade power output is analyzed. An optimization model to explore the trade-offs between hydropower generation and ice flood control requirements is developed. The model takes into account ice flood control requirements. The optimization model compared to simulation model based on the reservoir operation rule curves. The results show that the optimal operation rules are far more efficient in balancing the benefits within the power generation and ice flood control. The cascade reservoirs operation strategies proposed in this study can be effectively and suitably used in reservoir operation systems with similar conditions.

  7. Developing an Intelligent Reservoir Flood Control Decision Support System through Integrating Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Chang, L. C.; Kao, I. F.; Tsai, F. H.; Hsu, H. C.; Yang, S. N.; Shen, H. Y.; Chang, F. J.

    2015-12-01

    Typhoons and storms hit Taiwan several times every year and cause serious flood disasters. Because the mountainous terrain and steep landform rapidly accelerate the speed of flood flow, rivers cannot be a stable source of water supply. Reservoirs become one of the most important and effective floodwater storage facilities. However, real-time operation for reservoir flood control is a continuous and instant decision-making process based on rules, laws, meteorological nowcast, in addition to the immediate rainfall and hydrological data. The achievement of reservoir flood control can effectively mitigate flood disasters and store floodwaters for future uses. In this study, we construct an intelligent decision support system for reservoir flood control through integrating different types of neural networks and the above information to solve this problem. This intelligent reservoir flood control decision support system includes three parts: typhoon track classification, flood forecast and adaptive water release models. This study used the self-organizing map (SOM) for typhoon track clustering, nonlinear autoregressive with exogenous inputs (NARX) for multi-step-ahead reservoir inflow prediction, and adaptive neuro-fuzzy inference system (ANFIS) for reservoir flood control. Before typhoons landfall, we can estimate the entire flood hydrogragh of reservoir inflow by using SOM and make a pre-release strategy and real-time reservoir flood operating by using ANFIS. In the meanwhile, NARX can be constantly used real-time five-hour-ahead inflow prediction for providing the newest flood information. The system has been successfully implemented Typhoons Trami (2013), Fitow (2013) and Matmo (2014) in Shihmen Reservoir.

  8. Dynamic control of flood limited water level for reservoir operation by considering inflow uncertainty

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Guo, Shenglian; Liu, Pan; Chen, Guiya

    2010-09-01

    SummaryAccording to the Chinese Flood Control Act, reservoir water levels generally are not allowed to exceed the flood limited water level (FLWL) during flood season in order to offer adequate storage for flood prevention. However, the operation rules based on the current FLWL have neglected meteorological and real-time flood forecasting information and give too much priority to low probability floods. For floodwater utilization, dynamic control of reservoir FLWL is a valuable and effective methodology to compromise between flood control and conservation for reservoir operation during the flood season. The dynamic control bound is a fundamental key element for implementing reservoir FLWL dynamic control operation. In this paper, a dynamic control operation model that considers inflow uncertainty, i.e. the inflow forecasting error and uncertainty of the flood hydrograph shape is proposed and developed. The model consists of three modules: the first one is a pre-release module, which is used to estimate the upper boundary of dynamic control bound on basis of inflow forecasting results; the second one is a refill operation module, which is used to retain recession flood, and the third one is a risk analysis module, which is used to assess flood risk. The acceptable flood control operation risk constraints and quantificational analysis methods are given, and the dynamic control bound of reservoir FLWL is estimated by using Monte Carlo simulation. The China's three gorges reservoir (TGR) is selected as a case study. A multiple-input single-output linear systematic model is chosen for inflow forecasting of the TGR, and the future inflows are derived from gauged records by assuming that the inflow forecasting error follows a normal distribution. The application results show that the dynamic control of reservoir FLWL can effectively increase hydropower generation and the floodwater utilization rate without increasing flood control risk.

  9. Credibility theory based dynamic control bound optimization for reservoir flood limited water level

    NASA Astrophysics Data System (ADS)

    Jiang, Zhiqiang; Sun, Ping; Ji, Changming; Zhou, Jianzhong

    2015-10-01

    The dynamic control operation of reservoir flood limited water level (FLWL) can solve the contradictions between reservoir flood control and beneficial operation well, and it is an important measure to make sure the security of flood control and realize the flood utilization. The dynamic control bound of FLWL is a fundamental key element for implementing reservoir dynamic control operation. In order to optimize the dynamic control bound of FLWL by considering flood forecasting error, this paper took the forecasting error as a fuzzy variable, and described it with the emerging credibility theory in recent years. By combining the flood forecasting error quantitative model, a credibility-based fuzzy chance constrained model used to optimize the dynamic control bound was proposed in this paper, and fuzzy simulation technology was used to solve the model. The FENGTAN reservoir in China was selected as a case study, and the results show that, compared with the original operation water level, the initial operation water level (IOWL) of FENGTAN reservoir can be raised 4 m, 2 m and 5.5 m respectively in the three division stages of flood season, and without increasing flood control risk. In addition, the rationality and feasibility of the proposed forecasting error quantitative model and credibility-based dynamic control bound optimization model are verified by the calculation results of extreme risk theory.

  10. Stage-wise optimizing operating rules for flood control in a multi-purpose reservoir

    NASA Astrophysics Data System (ADS)

    Chou, Frederick N.-F.; Wu, Chia-Wen

    2015-02-01

    This paper presents a generic framework of release rules for reservoir flood control operation during three stages. In the stage prior to flood arrival, the rules indicate the timing and release discharge of pre-releasing reservoir storage to the initial level of flood control operation. In the stage preceding the flood peak, the rules prescribe the portion of inflow to be detained to mitigate downstream flooding, without allowing the water surface level of reservoir to exceed the acceptable safety level of surcharge. After the flood peak, the rules suggest the timing for stepwise reduction of the release flows and closing the gates of spillways and other outlets to achieve the normal level of conservation use. A simulation model is developed and linked with BOBYQA, an efficient optimization algorithm, to determine the optimal rule parameters in a stage-wise manner. The release rules of Shihmen Reservoir of Taiwan are established using inflow records of 59 historical typhoons and the probable maximum flood. The deviations from target levels at the end of different stages of all calibration events are minimized by the proposed method to improve the reliability of flood control operation. The optimized rules satisfy operational objectives including dam safety, flood mitigation, achieving sufficient end-of-operation storage for conservation purposes and smooth operation.

  11. 18 CFR 1304.407 - Development within flood control storage zones of TVA reservoirs.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... water-use facilities; (2) Commercial recreation boat dock and water-use facilities; (3) Water intake... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Development within flood control storage zones of TVA reservoirs. 1304.407 Section 1304.407 Conservation of Power and...

  12. 18 CFR 1304.407 - Development within flood control storage zones of TVA reservoirs.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... water-use facilities; (2) Commercial recreation boat dock and water-use facilities; (3) Water intake... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Development within flood control storage zones of TVA reservoirs. 1304.407 Section 1304.407 Conservation of Power and...

  13. 18 CFR 1304.407 - Development within flood control storage zones of TVA reservoirs.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... water-use facilities; (2) Commercial recreation boat dock and water-use facilities; (3) Water intake... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Development within flood control storage zones of TVA reservoirs. 1304.407 Section 1304.407 Conservation of Power and...

  14. 18 CFR 1304.407 - Development within flood control storage zones of TVA reservoirs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... water-use facilities; (2) Commercial recreation boat dock and water-use facilities; (3) Water intake... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Development within flood control storage zones of TVA reservoirs. 1304.407 Section 1304.407 Conservation of Power and...

  15. 18 CFR 1304.407 - Development within flood control storage zones of TVA reservoirs.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... water-use facilities; (2) Commercial recreation boat dock and water-use facilities; (3) Water intake... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Development within flood control storage zones of TVA reservoirs. 1304.407 Section 1304.407 Conservation of Power and...

  16. Soil and Sediment Properties Affecting the Transport and Accumulations of Mercury in a Flood Control Reservoir

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mercury accumulations in some fish species from Grenada Lake in north Mississippi exceed the Food and Drug Administration standards for human consumption. This large flood control reservoir serves as a sink for the Skuna and Yalobusha River watersheds whose highly erodible soils contribute to exces...

  17. Multi-phase intelligent decision model for reservoir real-time flood control during typhoons

    NASA Astrophysics Data System (ADS)

    Hsu, Nien-Sheng; Huang, Chien-Lin; Wei, Chih-Chiang

    2015-03-01

    This study applies an Adaptive Network-based Fuzzy Inference System (ANFIS) and a Real-Time Recurrent Learning Neural Network (RTRLNN) with an optimized reservoir release hydrograph using Mixed Integer Linear Programming (MILP) from historical typhoon events to develop a multi-phase intelligent real-time reservoir operation model for flood control. The flood control process is divided into three stages: (1) before flood (Stage I); (2) before peak flow (Stage II); and (3) after peak flow (Stage III). The models are then constructed with either three phase modules (ANFIS-3P and RTRLNN-3P) or two phase (Stage I + II and Stage III) modules (ANFIS-2P and RTRLNN-2P). The multi-phase modules are developed with consideration of the difference in operational decision mechanisms, decision information, release functions, and targets between each flood control stage to solve the problem of time-consuming computation and difficult system integration of MILP. In addition, the model inputs include the coupled short lead time and total reservoir inflow forecast information that are developed using radar- and satellite-based meteorological monitoring techniques, forecasted typhoon tracks, meteorological image similarity analysis, ANFIS and RTRLNN. This study uses the Tseng-Wen Reservoir basin as the study area, and the model results showed that RTRLNN outperformed ANFIS in the simulated outcomes from the optimized hydrographs. This study also applies the models to Typhoons Kalmaegi and Morakot to compare the simulations to historical operations. From the operation results, the RTRLNN-3P model is better than RTRLNN-2P and historical operations. Further, because the RTRLNN-3P model combines the innovative multi-phase module with monitored and forecasted decision information, the operation can simultaneously, effectively and automatically achieve the dual goals of flood detention at peak flow periods and water supply at the end of a typhoon event.

  18. Application of Decision Tree to Obtain Optimal Operation Rules for Reservoir Flood Control Considering Sediment Desilting-Case Study of Tseng Wen Reservoir

    NASA Astrophysics Data System (ADS)

    ShiouWei, L.

    2014-12-01

    Reservoirs are the most important water resources facilities in Taiwan.However,due to the steep slope and fragile geological conditions in the mountain area,storm events usually cause serious debris flow and flood,and the flood then will flush large amount of sediment into reservoirs.The sedimentation caused by flood has great impact on the reservoirs life.Hence,how to operate a reservoir during flood events to increase the efficiency of sediment desilting without risk the reservoir safety and impact the water supply afterward is a crucial issue in Taiwan.  Therefore,this study developed a novel optimization planning model for reservoir flood operation considering flood control and sediment desilting,and proposed easy to use operating rules represented by decision trees.The decision trees rules have considered flood mitigation,water supply and sediment desilting.The optimal planning model computes the optimal reservoir release for each flood event that minimum water supply impact and maximum sediment desilting without risk the reservoir safety.Beside the optimal flood operation planning model,this study also proposed decision tree based flood operating rules that were trained by the multiple optimal reservoir releases to synthesis flood scenarios.The synthesis flood scenarios consists of various synthesis storm events,reservoir's initial storage and target storages at the end of flood operating.  Comparing the results operated by the decision tree operation rules(DTOR) with that by historical operation for Krosa Typhoon in 2007,the DTOR removed sediment 15.4% more than that of historical operation with reservoir storage only8.38×106m3 less than that of historical operation.For Jangmi Typhoon in 2008,the DTOR removed sediment 24.4% more than that of historical operation with reservoir storage only 7.58×106m3 less than that of historical operation.The results show that the proposed DTOR model can increase the sediment desilting efficiency and extend the

  19. Flood mitigation through optimal control of a network of multi-purpose reservoirs by using Model Predictive Control

    NASA Astrophysics Data System (ADS)

    MyoLin, Nay; Rutten, Martine; van de Giesen, Nick

    2016-04-01

    Flooding is a common natural disaster in the world. Construction of reservoirs, sluice gates, dikes, embankments and sea walls are implemented to minimize loss of life and property in a flood event. Rather than completely relying on large structural measures, non-structural measures such as real time control of a reservoir system can also improve flood prevention and water supply in a river basin. In this paper, we present the optimal operation of a multi-reservoir system by using Model Predictive Control (MPC) and particular attention is focused on flood mitigation of the Sittaung River Basin, Myanmar. The main challenges are non-linearity in the dynamic behavior of the water system and exponential growth of computational complexity with the state and control dimension. To deal with an issue related to non-linearity, we applied simplified internal model based on linearization scheme with a large grid length. For solving curse of dimensionality, we utilize the reduced model in which the states of the system are reduced by considering outflows from uncontrolled catchments as disturbances in the water system. We also address the computational time for real time control by using large time step scheme. Simulation results indicate that this model is able to use for real time control of a reservoir system addressing trade-offs between the multiple objectives.

  20. Invertebrate colonization rates in the tailwater of a Kentucky flood-control reservoir

    USGS Publications Warehouse

    Swink, W.D.; Novotny, J.F.

    1985-01-01

    Invertebrate colonization on newly introduced rock substrates was examined from July through October 1982 in the tailwater of Barren River Lake, Kentucky. Chironomidae, the dominant taxon of benthic insects, reached full colonization by day 14. Colonization by Oligochaeta, the other major invertebrate taxon, was not completed by the end of the 95-day period of observation. It may have been delayed because insufficient food (periphyton and detritus) had accumulated on the clean rocks. Rapid recolonization of dewatered substrates may be especially critical for maintaining adequate fish food in tailwaters of flood-control reservoir.

  1. Effects of a Kentucky flood-control reservoir on macroinvertebrates in the tailwater

    USGS Publications Warehouse

    Novotny, J.F.

    1985-01-01

    The effects of a flood-control reservoir on downstream macroinvertebrates were assessed by comparing the tailwater community with that of a natural stream. Samples were collected 1.6 and 21.1 km below Barren River Lake dam in 1979, 1980, and 1981 and in a reservoir tributary in 1980 and 1981. An indication of environmental stress in the macroinvertebrate community was observed at both tailwater stations, whereas macroinvertebrates in the natural tributary stream had the characteristics commonly associated with a ‘healthy’ community. Densities of macroinvertebrates in tailwaters were highest during periods of low-stable flows and lowest during fluctuating and high-stable flows. Changes in temperature cycles and water quality were also considered factors in reducing macroinvertebrate abundance in the tailwater. Dominant macroinvertebrate taxa in tailwaters were primarily small organisms with a high tolerance for dynamic living conditions. Of these, aquatic Diptera, Oligochaeta, Caenis, Cheumatopsyche, and Planariidae were most common. The effects of reservoir discharge were most evident near the dam, where macroinvertebrate densities were relatively high and taxonomic diversity was low. Downstream, the impact of the reservoir was moderated, but recovery was judged incomplete.

  2. Conjunctively optimizing flash flood control and water quality in urban water reservoirs by model predictive control and dynamic emulation

    NASA Astrophysics Data System (ADS)

    Galelli, Stefano; Goedbloed, Albert; Schmitter, Petra; Castelletti, Andrea

    2014-05-01

    Urban water reservoirs are a viable adaptation option to account for increasing drinking water demand of urbanized areas as they allow storage and re-use of water that is normally lost. In addition, the direct availability of freshwater reduces pumping costs and diversifies the portfolios of drinking water supply. Yet, these benefits have an associated twofold cost. Firstly, the presence of large, impervious areas increases the hydraulic efficiency of urban catchments, with short time of concentration, increased runoff rates, losses of infiltration and baseflow, and higher risk of flash floods. Secondly, the high concentration of nutrients and sediments characterizing urban discharges is likely to cause water quality problems. In this study we propose a new control scheme combining Model Predictive Control (MPC), hydro-meteorological forecasts and dynamic model emulation to design real-time operating policies that conjunctively optimize water quantity and quality targets. The main advantage of this scheme stands in its capability of exploiting real-time hydro-meteorological forecasts, which are crucial in such fast-varying systems. In addition, the reduced computational requests of the MPC scheme allows coupling it with dynamic emulators of water quality processes. The approach is demonstrated on Marina Reservoir, a multi-purpose reservoir located in the heart of Singapore and characterized by a large, highly urbanized catchment with a short (i.e. approximately one hour) time of concentration. Results show that the MPC scheme, coupled with a water quality emulator, provides a good compromise between different operating objectives, namely flood risk reduction, drinking water supply and salinity control. Finally, the scheme is used to assess the effect of source control measures (e.g. green roofs) aimed at restoring the natural hydrological regime of Marina Reservoir catchment.

  3. In the Way of Peacemaker Guide Curve between Water Supply and Flood Control for Short Term Reservoir Operation

    NASA Astrophysics Data System (ADS)

    Uysal, G.; Sensoy, A.; Yavuz, O.; Sorman, A. A.; Gezgin, T.

    2012-04-01

    Effective management of a controlled reservoir system where it involves multiple and sometimes conflicting objectives is a complex problem especially in real time operations. Yuvacık Dam Reservoir, located in the Marmara region of Turkey, is built to supply annual demand of 142 hm3 water for Kocaeli city requires such a complex management strategy since it has relatively small (51 hm3) effective capacity. On the other hand, the drainage basin is fed by both rainfall and snowmelt since the elevation ranges between 80 - 1548 m. Excessive water must be stored behind the radial gates between February and May in terms of sustainability especially for summer and autumn periods. Moreover, the downstream channel physical conditions constraint the spillway releases up to 100 m3/s although the spillway is large enough to handle major floods. Thus, this situation makes short term release decisions the challenging task. Long term water supply curves, based on historical inflows and annual water demand, are in conflict with flood regulation (control) levels, based on flood attenuation and routing curves, for this reservoir. A guide curve, that is generated using both water supply and flood control of downstream channel, generally corresponds to upper elevation of conservation pool for simulation of a reservoir. However, sometimes current operation necessitates exceeding this target elevation. Since guide curves can be developed as a function of external variables, the water potential of a basin can be an indicator to explain current conditions and decide on the further strategies. Besides, releases with respect to guide curve are managed and restricted by user-defined rules. Although the managers operate the reservoir due to several variable conditions and predictions, still the simulation model using variable guide curve is an urgent need to test alternatives quickly. To that end, using HEC-ResSim, the several variable guide curves are defined to meet the requirements by

  4. Effect of multiyear drought on upland sediment yield and subsequent impacts on flood control reservoir storage

    NASA Astrophysics Data System (ADS)

    Dunbar, John A.; Allen, Peter M.; Bennett, Sean J.

    2010-05-01

    Since the early 1950s, the U.S. Soil Conservation Service (SCS) and later the U.S. Department of Agriculture Natural Resources Conservation Service has built over 11,000 flood control reservoirs (FCR) in 47 states. FCR built in Texas and Oklahoma in the early 1950s to mid-1950s were impounded during the most severe drought on record in the region. In this study, the sediment trapped in FCR is used to reconstruct the variation in sediment yield through the drought years to the present. New sediment surveys of four FCR in McCulloch County, Texas, are combined with three previous surveys by the SCS. The new surveys are conducted using acoustic profiling to map water depth and sediment thickness in submerged areas of the reservoirs and real-time kinematic GPS in the dry areas. Sediment coring is used to determine sediment dry bulk density. The survey results are used to construct a composite history of the normalized sediment yield for the study area. Normalized sediment yield is the annual sediment yield normalized by the soil erodability factor K and the combined slope length and steepness factor LS of the watershed. The results indicate that sediment yield was lowest during the relatively drought-free period from 1971 to 2007, averaging 4.2 t/ha/yr/unit K/unit LS and over 70 times higher during the early part of the 1950s drought from 1951 to 1953, averaging 300.3 t/ha/yr/unit K/unit LS. These results have important implications for predicting the remaining useful life of FCR in the region and planning for future droughts.

  5. Improved Efficiency of Miscible CO(2) Floods and Enhanced Prospects for CO(2) Flooding Heterogeneous Reservoirs.

    SciTech Connect

    Grigg, R.B.; Schechter, D.S.

    1997-08-01

    The overall goal of this project was to improve the efficiency of miscible C0{sub 2} floods and enhance the prospects for flooding heterogeneous reservoirs. This objective was accomplished through experimental and modeling research in three task areas: (1) foams for selective mobility control in heterogeneous reservoirs,( 2) reduction of the amount of C0{sub 2} required in C0{sub 2} floods, and (3) low IFT processe and the possibility of C0{sub 2} flooding in fractured reservoirs. This report provides results from the three-year project for each of the three task areas.

  6. Impact of flood control reservoirs and pollution influx on the Sandy Creek Watershed, Mercer County, Pennsylvania, USA

    NASA Astrophysics Data System (ADS)

    Brenner, Fred J.; Kanour, William; Weston, Bruce; Valerio, Gerald; Grayburn, Kenneth R.

    1986-03-01

    A study of the impact of two flood control reservoirs and pollution influx was conducted on two streams within the Sandy Creek Watershed, Mercer County, Pennsylvania, USA. Fecal coliforms were significantly reduced in the outflows without affecting water chemistry, thereby improving the overall water quality. The size and composition of the aquatic communities as well as stream metabolism varied seasonably among the different sampling stations. Pollution influx primarily from communities and agricultural drainage had a greater impact on the stream ecosystem than did impounding of the streams. Natural wetlands and riparian vegetation were important factors in reducing the pollution load in these streams. The reestablishment and maintenance of riparian vegetation should therefore be an integral part of the land-use plan for watersheds in order to improve water quality and wildlife habitats. In the future, the maintenance of riparian vegetation should be given prime consideration in the development of watershed projects.

  7. CONTAMINANT RESULTS FROM AGRICULTURE AND DRAINAGE CHANGES ON A FLOOD CONTROL RESERVOIR IN MISSISSIPPI, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analyses were conducted in water and sediment for 8 metals and 46 pesticides/contaminants at 25 stream/river locations within the Yalobusha River watershed and at 9 locations within Grenada Lake reservoir in north Mississippi. Most pesticides were detected seasonally at low concentrations in contri...

  8. Improved Efficiency of Miscible CO2 Floods and Enhanced Prospects for CO2 Flooding Heterogeneous Reservoirs

    SciTech Connect

    Grigg, Reid B.; Schechter, David S.

    1999-10-15

    The goal of this project is to improve the efficiency of miscible CO2 floods and enhance the prospects for flooding heterogeneous reservoirs. This report provides results of the second year of the three-year project that will be exploring three principles: (1) Fluid and matrix interactions (understanding the problems). (2) Conformance control/sweep efficiency (solving the problems. 3) Reservoir simulation for improved oil recovery (predicting results).

  9. Effects of flood control and other reservoir operations on the water quality of the lower Roanoke River, North Carolina

    USGS Publications Warehouse

    Garcia, Ana Maria

    2012-01-01

    The Roanoke River is an important natural resource for North Carolina, Virginia, and the Nation. Flood plains of the lower Roanoke River, which extend from Roanoke Rapids Dam to Batchelor Bay near Albemarle Sound, support a large and diverse population of nesting birds, waterfowl, freshwater and anadromous fish, and other wildlife, including threatened and endangered species. The flow regime of the lower Roanoke River is affected by a number of factors, including flood-management operations at the upstream John H. Kerr Dam and Reservoir. A three-dimensional, numerical water-quality model was developed to explore links between upstream flows and downstream water quality, specifically in-stream dissolved-oxygen dynamics. Calibration of the hydrodynamics and dissolved-oxygen concentrations emphasized the effect that flood-plain drainage has on water and oxygen levels, especially at locations more than 40 kilometers away from the Roanoke Rapids Dam. Model hydrodynamics were calibrated at three locations on the lower Roanoke River, yielding coefficients of determination between 0.5 and 0.9. Dissolved-oxygen concentrations were calibrated at the same sites, and coefficients of determination ranged between 0.6 and 0.8. The model has been used to quantify relations among river flow, flood-plain water level, and in-stream dissolved-oxygen concentrations in support of management of operations of the John H. Kerr Dam, which affects overall flows in the lower Roanoke River. Scenarios have been developed to mitigate the negative effects that timing, duration, and extent of flood-plain inundation may have on vegetation, wildlife, and fisheries in the lower Roanoke River corridor. Under specific scenarios, the model predicted that mean dissolved-oxygen concentrations could be increased by 15 percent by flow-release schedules that minimize the drainage of anoxic flood-plain waters. The model provides a tool for water-quality managers that can help identify options that improve

  10. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30, 1993

    SciTech Connect

    Somasundaran, P.

    1994-07-01

    The aim of this research project is to investigate mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy will be determined. A multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability; is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the first year of this three year contract, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Surfactants studied include alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amount of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed.

  11. Surfactant loss control in chemical flooding spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30 1995

    SciTech Connect

    Casteel, J.

    1996-07-01

    The aim of this research project was to investigate mechanisms governing adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy have been determined. A multi-pronged approach consisting of micro & nano spectroscopy, electrokinetics, surface tension and wettability is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the three years contract period, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride were the surfactants studied. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes in interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amounts of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed. Changes of microstructure upon dilution (desorption) were also studied. Presence of the nonionic surfactants in mixed aggregate leads to shielding of the charge of ionic surfactants which in turn promotes aggregation but reduced electrostatic attraction between the charged surfactant and the mineral surface. Strong consequences of surfactant interactions in solution on adsorption as well as correlations between monomer concentration in mixtures and adsorption were revealed.

  12. The Cumberland River Flood of 2010 and Corps Reservoir Operations

    NASA Astrophysics Data System (ADS)

    Charley, W.; Hanbali, F.; Rohrbach, B.

    2010-12-01

    On Saturday, May 1, 2010, heavy rain began falling in the Cumberland River Valley and continued through the following day. 13.5 inches was measured at Nashville, an unprecedented amount that doubled the previous 2-day record, and exceeded the May monthly total record of 11 inches. Elsewhere in the valley, amounts of over 19 inches were measured. The frequency of this storm was estimated to exceed the one-thousand year event. This historic rainfall brought large scale flooding to the Cumberland-Ohio-Tennessee River Valleys, and caused over 2 billion dollars in damages, despite the numerous flood control projects in the area, including eight U.S. Army Corps of Engineers projects. The vast majority of rainfall occurred in drainage areas that are uncontrolled by Corps flood control projects, which lead to the wide area flooding. However, preliminary analysis indicates that operations of the Corps projects reduced the Cumberland River flood crest in Nashville by approximately five feet. With funding from the American Recovery and Reinvestment Act (ARRA) of 2009, hydrologic, hydraulic and reservoir simulation models have just been completed for the Cumberland-Ohio-Tennessee River Valleys. These models are being implemented in the Corps Water Management System (CWMS), a comprehensive data acquisition and hydrologic modeling system for short-term decision support of water control operations in real time. The CWMS modeling component uses observed rainfall and forecasted rainfall to compute forecasts of river flows into and downstream of reservoirs, using HEC-HMS. Simulation of reservoir operations, utilizing either the HEC-ResSim or CADSWES RiverWare program, uses these flow scenarios to provide operational decision information for the engineer. The river hydraulics program, HEC-RAS, computes river stages and water surface profiles for these scenarios. An inundation boundary and depth map of water in the flood plain can be calculated from the HEC-RAS results using Arc

  13. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Quarterly technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Somasundaran, P.

    1993-05-01

    The aim of this project is to elucidate the mechanisms of adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effect of surfactant structure, surfactant combinations and other inorganic and polymeric species will be determined using solids of relevant mineralogy. A multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability win be used to achieve the goals. The results of this study should help in controlling surfactant loss in chemical flooding and also in developing optimum structures and conditions for efficient chemical flooding processes. Adsorption of selected individual surfactants on oxide minerals was studied. The aim was to determine the effect of structure on surfactant adsorption at the solid-liquid as well as at the liquid-air interface. Nonionic polyethoxylated alkyl phenols and anionic meta xylene sulfonates (MXS) were the surfactants studied. Electrokinetic behavior was also determined along with adsorption in order to determine the role of electrostatic forces in determining the adsorption. In addition, the effect of varying the number of ethylene oxide groups on the adsorption of polyethoxylated alkyl phenols on silica was determined since the ethoxyl groups offer unique opportunities to control adsorption as well as wettability. Effect of pH was studied both because it is a parameter with first order effect and also because pH effects can help in developing mechanisms.

  14. Process for emulsion flooding of petroleum reservoirs

    SciTech Connect

    Lepper, U.

    1984-12-18

    A process for emulsion flooding of petroleum reservoirs comprising injecting a thermodynamically stable microemulsion consisting of oil, a non-ionic surfactant and water which optionally contains salts dissolved in any desired concentrations, into an injection well; driving injected microemulsion bank through the reservoir by means of water which likewise may contain salts dissolved in any desired concentrations. The microemulsion bank in contact with the water driving the bank forms an excess phase with a high water content, a low surfactant content and low oil content, and has such a viscosity sufficient to prevent the penetration of the subsequent water into the microemulsion bank which would cause a decrease of its flowability and its ability to displace oil.

  15. Surfactant loss control in chemical flooding spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1993--September 30, 1994

    SciTech Connect

    Somasundaran, P.

    1995-06-01

    The aim of this project is to elucidate the mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effect of surfactant structure, surfactant combinations, other inorganic and polymeric species is being studied. A multi-pronged approach consisting of micro and nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability is used to achieve the goals. The results of this study should help in controlling surfactant loss in chemical flooding and also in developing optimum structures and conditions for efficient chemical flooding processes. During the second year of this three year contract, adsorption/desorption of single surfactants and select surfactant mixtures on alumina and silica was studied. Surfactants studied include the anionic sodium dodecyl sulfate (SDS), cationic tetradecyl trimethyl ammonium chloride (TTAC), nonionic pentadecylethoxylated nonyl phenol (NP-15) and the nonionic octaethylene glycol n-dodecyl ether (C{sub 12}EO{sub 8}) of varying hydrocarbon chain length. The microstructure of the adsorbed layer in terms of micropolarity and aggregation numbers was probed using fluorescence spectroscopy. Changes of microstructure upon dilution (desorption) were also studied. Presence of the nonionic surfactant in the mixed aggregate led to shielding of the charge of the ionic surfactant which in-turn promoted aggregation but reduced electrostatic attraction between the charged surfactant and the mineral surface. Strong consequences of surfactant interactions in solution upon adsorption as well as correlations between monomer concentrations in mixtures and adsorption were revealed.

  16. Floods, flood control, and bottomland vegetation

    USGS Publications Warehouse

    Friedman, Jonathan M.; Auble, Gregor T.

    2000-01-01

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

  17. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Somasundaran, P.

    1993-08-31

    The aim of this contract is to elucidate the mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. The results of this study should help in controlling surfactant loss in chemical flooding and also in developing optimum structures and conditions for efficient chemical flooding processes. Adsorption of single surfactants on silica and alumina as well as the solution behavior of surfactant mixtures was studied during this quarter. The adsorption of surfactants at the solid-liquid interface was correlated with changes in interfacial behavior such as wettability and zeta potential. Surface tension was used to study interactions between surfactant mixtures in solution. Mixed micellization of sodium dodecyl sulfate and dodecyl phenoxy polyethoxylated alcohol was found to be non-ideal. Regular solution theory adequately describes the interactions. The adsorption isotherm of a cationic surfactant, tetradecyl trimethyl ammonium chloride (TTAC), on alumina was determined at two values of pH. Changes in the settling rate of alumina suspensions after TTAC adsorption were also followed to describe the evolution of the adsorbed layer. At high surface coverage it was observed that the alumina surface became hydrophilic suggesting the formation of a TTAC bilayer at the surface. Wettability of silica after adsorption of nonyl phenyl polyethoxylated alcohols (with number of polyethylene oxide groups varying from 10-40) was measured using flotation to determine the orientation of the adsorbed layer. Effect of number of ethylene oxide groups was also determined. The amount of silica floated after the nonionic surfactant adsorption was same irrespective of the ethylene oxide chain length.

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

    USGS Publications Warehouse

    Perry, Charles A.

    1994-01-01

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

  19. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Annual report, April 14, 1994--April 13, 1995

    SciTech Connect

    Grigg, R.; Heller, J.; Schechter, D.

    1995-09-01

    The overall goal of this project is to improve the efficiency of miscible CO{sub 2} floods and enhance the prospects for flooding heterogeneous reservoirs. This objective is being accomplished by extending experimental research in three task areas: (1) foams for selective mobility control in heterogeneous reservoirs, (2) reduction of the amount of CO{sub 2} required in CO{sub 2} floods, and (3) miscible CO{sub 2} flooding in fractured reservoirs. This report provides results of the first year of the three-year project for each of the three task areas.

  20. Improved Efficiency of Miscible CO{sub 2} Floods and Enhanced Prospects for CO{sub 2} Flooding Heterogeneous Reservoirs

    SciTech Connect

    Boyun Guo; David S. Schechter; Jyun-Syung Tsau; Reid B. Grigg; Shih-Hsien Chang

    1997-10-31

    This work will examine three major areas in which CO{sub 2} flooding can be improved: fluid and matrix interactions, conformance control/sweep efficiency, and reservoir simulation for improved oil recovery. The first full quarter of this project has been completed. We began examining synergistic affects of mixed surfactant versus single surfactant systems to enhance the properties of foams used for improving oil recovery in CO{sub 2} floods. The purpose is to reduce the concentration of surfactants or finding less expensive surfactants. Also, we are examining the effect of oil saturation on the development of foam in CO{sub 2}-surfactant solution systems. CO{sub 2} flooding of low permeability, vugular, and fracture reservoirs are another major thrust of this project. Work conducted this quarter involved simulating gravity stable floods using large core samples; results showed excellent recovery in a low permeability vugular core.

  1. Exploring increase of flood attenuation potential of reservoirs through simple gates operations.

    NASA Astrophysics Data System (ADS)

    Masoero, A.; Claps, P.; Ganora, D.; Petaccia, A.

    2012-04-01

    Along with other flood risk mitigation measures, artificial flood storage has been considered as a mean to control flood peaks in mountainous basins, particularly as part of the flood management practices. Classical studies attain the evaluation of the 'natural' flood attenuation potential driven by the portion of volume available above the spillway crest level. These studies allow to reconstruct modified flood frequency curves in sections downstream as modified by this unconditioned type of attenuation. Less understood is the possibility to quantify the additional attenuation potential of reservoirs deriving by simple and standardized gates operations. Unconditioned gates opening in advance with respect to the incoming flood are the typical operations considered in this work. The study has been carried out using a system of 63 artificial reservoirs located in the Northwestern part of Italy, for which a comprehensive set of hydrological and hydraulic data has been collected with the help of the Italian Dams Authority (Registro Italiano Dighe, RID). The main aim of the study is to select the most interesting cases in which gates operation is able to consistently improve flood attenuation, and provide an overview of the effect that these dams exercise on the flood frequency curves of the river sections downstream. For what the 'natural' attenuation potential is concerned, an attenuation index named SFA (Synthetic Flood Attenuation) has been computed on all dams and subsequently used to modify the original frequency curve of the incoming floods. A recent regional statistical method for flood estimation has been used for this purpose. With the help of the same model and of additional information required to describe flood volumes, triangular and power-law synthetic flood hydrographs have been simulated. Gates operation is addressed to a preemptive drawdown, and is conceived as a fixed opening in defined conditions at the flood arrival. Consequently, the maximum

  2. Foam flooding reservoir simulation algorithm improvement and application

    NASA Astrophysics Data System (ADS)

    Wang, Yining; Wu, Xiaodong; Wang, Ruihe; Lai, Fengpeng; Zhang, Hanhan

    2014-05-01

    As one of the important enhanced oil recovery (EOR) technologies, Foam flooding is being used more and more widely in the oil field development. In order to describe and predict foam flooding, experts at domestic and abroad have established a number of mathematical models of foam flooding (mechanism, empirical and semi-empirical models). Empirical models require less data and apply conveniently, but the accuracy is not enough. The aggregate equilibrium model can describe foam generation, burst and coalescence by mechanism studying, but it is very difficult to accurately describe. The research considers the effects of critical water saturation, critical concentration of foaming agent and critical oil saturation on the sealing ability of foam and considers the effect of oil saturation on the resistance factor for obtaining the gas phase relative permeability and the results were amended by laboratory test, so the accuracy rate is higher. Through the reservoir development concepts simulation and field practical application, the calculation is more accurate and higher.

  3. Operational trade-offs in reservoir control

    NASA Astrophysics Data System (ADS)

    Georgakakos, Aris P.

    1993-11-01

    Reservoir operation decisions require constant reevaluation in the face of conflicting objectives, varying hydrologic conditions, and frequent operational policy changes. Optimality is a relative concept very much dependent on the circumstances under which a decision is made. More than anything else, reservoir management authorities need the means to assess the impacts of various operational options. It is their responsibility to define what is desirable after a thorough evaluation of the existing circumstances. This article presents a model designed to generate operational trade-offs common among reservoir systems. The model avoids an all-encompassing problem formulation and distinguishes three operational modes (levels) corresponding to normal, drought, and flood operations. Each level addresses only relevant system elements and uses a static and a dynamic control module to optimize turbine performance within each planning period and temporally. The model is used for planning the operation of the Savannah River System.

  4. Can the annual flood control volume at Three Gorges Dam be predicted to size a variable flood control pool?

    NASA Astrophysics Data System (ADS)

    DONG, Q.; Lall, U.

    2014-12-01

    We consider the empirical prediction of the peak flood volume on the Yangtze River at the Three Gorges Dam. The dam is operated for flood control, hydropower production and irrigation. The flood control space reserved in the reservoir each year during the monsoon season limits the ability to supply hydropower and irrigation services. Allocating a variable amount of flood control space based on a pre-season forecast of the peak event flood volume, or of the flood volume over a specific duration is consequently, more useful than a prediction of the annual maximum peak flow for this dam and for other flood control dams. The joint distribution of annual peak flow, the corresponding flood volume, and the event duration is investigated based on the copula theory. A statistical model is developed for the conditional prediction of this joint distribution using pre-season climate indicators. The potential for the guidance for water management in the Yangtze River basin and for insights to the design of the large flood control reservoirs in the future is illustrated.

  5. ALKALINE-SURFACTANT-POLYMER FLOODING AND RESERVOIR CHARACTERIZATION OF THE BRIDGEPORT AND CYPRESS RESERVOIRS OF THE LAWRENCE FIELD

    SciTech Connect

    Malcolm Pitts; Ron Damm; Bev Seyler

    2003-03-01

    Feasibility of alkaline-surfactant-polymer flood for the Lawrence Field in Lawrence County, Illinois is being studied. Two injected formulations are being designed; one for the Bridgeport A and Bridgeport B reservoirs and one for Cypress and Paint Creek reservoirs. Fluid-fluid and coreflood evaluations have developed a chemical solution that produces incremental oil in the laboratory from the Cypress and Paint Creek reservoirs. A chemical formulation for the Bridgeport A and Bridgeport B reservoirs is being developed. A reservoir characterization study is being done on the Bridgeport A, B, & D sandstones, and on the Cypress sandstone. The study covers the pilot flood area and the Lawrence Field.

  6. ALKALINE-SURFACTANT-POLYMER FLOODING AND RESERVOIR CHARACTERIZATION OF THE BRIDGEPORT AND CYPRESS RESERVOIRS OF THE LAWRENCE FIELD

    SciTech Connect

    Malcolm Pitts; Ron Damm; Bev Seyler

    2003-04-01

    Feasibility of alkaline-surfactant-polymer flood for the Lawrence Field in Lawrence County, Illinois is being studied. Two injected formulations are being designed; one for the Bridgeport A and Bridgeport B reservoirs and one for Cypress and Paint Creek reservoirs. Fluid-fluid and coreflood evaluations have developed a chemical solution that produces incremental oil in the laboratory from the Cypress and Paint Creek reservoirs. A chemical formulation for the Bridgeport A and Bridgeport B reservoirs is being developed. A reservoir characterization study is being done on the Bridgeport A, B, & D sandstones, and on the Cypress sandstone. The study covers the pilot flood area and the Lawrence Field.

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

    USGS Publications Warehouse

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

    1994-01-01

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

  8. Sedimentation in three small erosion control reservoirs in northern Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The water storage capacity and dam integrity of thousands of flood control reservoirs built since 1950 are potentially compromised by excessive impounded sediments. The fate of these structures depends on the amount and characteristics of this accumulated material. To aid in understanding the scop...

  9. Safety in the Chemical Laboratory: Flood Control.

    ERIC Educational Resources Information Center

    Pollard, Bruce D.

    1983-01-01

    Describes events leading to a flood in the Wehr Chemistry Laboratory at Marquette University, discussing steps taken to minimize damage upon discovery. Analyzes the problem of flooding in the chemical laboratory and outlines seven steps of flood control: prevention; minimization; early detection; stopping the flood; evaluation; clean-up; and…

  10. Reservoir characterization and steam flood monitoring with crosshole EM

    SciTech Connect

    Wilt, M.; Torres-Verdin, C.

    1995-06-01

    Crosshole electromagnetic (EM) imaging is applied to reservoir characterization and steam flood monitoring in a central California oil field. Steam was injected into three stacked eastward-dipping, unconsolidated oil sands within the upper 200 m. The steam plume is expected to develop as an ellipse aligned with the regional northwest-southeast strike. EM measurements were made from two fiberglass-cased observation wells straddling the steam injector on a northeast-southwest profile using the LLNL frequency domain crosshole EM system. Field data were collected before the initiation of a steam drive to map the distribution of the oil sands and then 6 and 12 months later to monitor the progress of the steam chest. Resistivity images derived from the EM data before steam injection clearly delineate the distribution and dipping structure on the target oil sands. Difference images, from data collected before and after steam flooding, show resistivity changes that indicate that the steam chest has developed only in the deeper oil sands although steam injection occurred in all three sand layers.

  11. 33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... use of reservoir storage space allocated for flood control or navigation and/or release functions of a... discharge and storage space required for flood control and/or navigation, based on the runoff potential... regarding the quantity and value of space to reserve in the reservoir for flood control and/or...

  12. 33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... use of reservoir storage space allocated for flood control or navigation and/or release functions of a... discharge and storage space required for flood control and/or navigation, based on the runoff potential... regarding the quantity and value of space to reserve in the reservoir for flood control and/or...

  13. 33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... use of reservoir storage space allocated for flood control or navigation and/or release functions of a... discharge and storage space required for flood control and/or navigation, based on the runoff potential... regarding the quantity and value of space to reserve in the reservoir for flood control and/or...

  14. 33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... use of reservoir storage space allocated for flood control or navigation and/or release functions of a... discharge and storage space required for flood control and/or navigation, based on the runoff potential... regarding the quantity and value of space to reserve in the reservoir for flood control and/or...

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

    USGS Publications Warehouse

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

    1994-01-01

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

  16. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Annual report, June 1, 1997--May 31, 1998

    SciTech Connect

    Grigg, R.B.; Schechter, D.S.

    1998-07-01

    The goal of this project is to improve the efficiency of miscible CO{sub 2} floods and enhance the prospects for flooding heterogeneous reservoirs. This report provides results of the first year of the three-year project that will be exploring three principle areas: (1) Fluid and matrix interactions (understanding the problems): interfacial tension (IFT), phase behavior, miscibility, capillary number, injectivity, wettability, and gravity drainage; (2) Conformance control/sweep efficiency (solving the problems): reduction of mobility using foam, diversion by selective mobility reduction (SMR) using foam, improved injectivity, alternating water and gas injection, and using horizontal wells; and (3) Reservoir simulation for improved oil recovery (predicting results): gravity drainage, SMR, CO{sub 2}-foam flooding, interfacial tension, injectivity profile, horizontal wells, and naturally fractured reservoirs. Studies of surfactant foam quality were performed during this first year. Simulation studies on a foam pilot area resulted in an acceptable history match model. The results confirm that the communication path between the foam injection well and a production well had a strong impact on the production performance. A laboratory study to aid in the development of a gravity drainage reservoir was undertaken on the Wellman Unit. Experiments were begun meant to duplicate situations of injectivity loss in WAG flooding and identify factors affecting the injectivity loss. The preliminary results indicate that for a given rock the injectivity loss depends on oil saturation in the core during WAG flooding. The injectivity loss is higher in cores with high in-situ oil saturations during WAG flooding. This effect is being verified by more experimental data.

  17. Flood-related, organic-carbon anomalies as possible temporal markers in reservoir bottom sediments

    USGS Publications Warehouse

    Juracek, K.E.

    2004-01-01

    Results of a study of sediment cores from four reservoirs in the upper Mississippi River Basin, USA, indicated that anomalous organic carbon concentrations associated with flood deposits may provide detectable temporal markers in reservoir bottom sediments. Temporal markers are needed for reservoir sediment studies to date sediment layers deposited between the 1963-64 cesium-137 peak and the present. For two of four reservoirs studied, anomalously low organic carbon concentrations were measured for a sample interval in the upper part of a sediment core. The anomalous interval was interpreted to have been deposited during the July 1993 flood that affected a large area of the upper Mississippi River Basin. Potentially, the July 1993 flood deposit may be used as a temporal marker in reservoir bottom sediments in parts of the basin affected by the flood. Several uncertainties remain regarding the viability of organic carbon as a temporal marker including the combination of flood, basin, and reservoir characteristics required to produce a recognizable organic carbon marker in the bottom sediment and the optimal sampling strategy needed to detect the marker in a sediment core. It is proposed that flood duration and basin size may be important factors as to whether or not an anomalous and detectable organic carbon layer is deposited in a reservoir. ?? Copyright by the North American Lake Management Society 2004.

  18. A pilot test of polymer flooding in an elevated-temperature reservoir

    SciTech Connect

    Tielong, Chen; Zhengyu, Song; Fan, Y.

    1996-12-31

    A pilot test of polymer flooding has been conducted in Shuanghe reservoir located in southeast Henan oil field, China. The target reservoir has a net thickness of 15.56 meters (50 ft), an average permeability of 420 md, and temperature of 75{degrees}C (167{degrees}F). The polymers used are two types of modified partially hydrolyzed polyacrylamides, named S525 and S625, which have molecular weights of 16,700,000 and 19,670,000 daltons, respectively. The objective of this pilot test is to investigate the feasibility of polymer flooding for improving oil recovery in an elevated-temperature reservoir. The polymer flooding started in February 1994. Up through December 1995, a total of 246 tons (about 0.5 x 106 lb) of dry polymer had been used with an injection concentration of 900-1100 ppm. The pore volume injected reached 0.2164. As a result, oil production increased by 22,000 tons (184,000 bbl) and water production decreased by 153,000 tons (962,000 bbl), which accounts for the incremental oil recovery of 3.8% and water-cut reduction of 5.6% in the test block. It is estimated that by the end of this project, the ultimate increase in oil production will exceed 63,000 tons (528,000 bbl) with the enhanced oil recovery going up to 9.8%. The yield is 0.2 tons more oil produced per kilogram of polymer injected or 0.7 barrel of oil produced per pound of polymer. The success of the pilot test is attributed to a few techniques used during the implementation of the flooding, including prevention of polymer thermal degradation, good reservoir description, and the profile modification carried out before and after the polymer injection. This pilot test illustrates a case where polymers with extra-high molecular weight are successfully injected in an elevated-temperature reservoir to control the mobility ratio and modify the permeability profile.

  19. Improved scleroglucan for polymer flooding under harsh reservoir conditions

    SciTech Connect

    Rivenq, R.C.; Donche, A. )

    1992-02-01

    Polymer flooding is commonly used to improve water sweep efficiency in oil reserves. Successful application of this method, however, has been restricted to low-temperature reservoirs because suitable polymers are not available for harsh conditions. Scleroglucan, a polymer produced by fermentation that shows promising properties, forms solutions that are very viscous and highly resistant to shear. Viscosity is insensitive to both salts and pH and only slightly affected by temperature. To facilitate industrial development of scleroglucan polymer, improvements in the filterability of the solutions and better knowledge of their behavior in porous media are necessary. A high-quality scleroglucan was obtained by eliminating the impurities responsible for polymer aggregation. This allowed evaluation of the intrinsic properties of the polymer molecules. Complete elimination of impurities from the polymer solution led to a scleroglucan without any aggregation tendency and with a good filterability, particularly at high temperatures. The performance of this improved scleroglucan in porous media was evaluated by coreflood experiments in Berea cores at temperatures ranging from 30 to 90{degrees} C. Results provided in this paper showed low permeability reduction and a mobility reduction close to relative viscosity. Injection of successive slugs into a Berea core under anaerobic conditions indicated low polymer retention at high temperatures (30 {mu}g/g at 90{degrees} C).

  20. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Annual report, April 18, 1995--April 17, 1996

    SciTech Connect

    Grigg, R.B.; Schechter, D.S.

    1996-10-01

    The overall goal of this project is to improve the efficiency of miscible CO{sub 2} floods and enhance the prospects for flooding heterogeneous reservoirs. This objective is being accomplished by extending experimental and modeling research in three task areas: (1) foams for selective mobility control in heterogeneous reservoirs, (2) reduction of the amount of CO{sub 2} required in CO{sub 2} floods, and (3) low IFT processes and the possibility of CO{sub 2} flooding in fractured reservoirs. This report provides results of the second year of the three-year project for each of the three task areas. In the first task, we are investigating a desirable characteristic of CO{sub 2}-foam called Selective Mobility Reduction (SMR) that results in an improvement in displacement efficiency by reducing the effects of reservoir heterogeneity. Research on SMR of foam during the past year has focused on three subjects: (1) to verify SMR in different rock permeabilities that are in capillary contact; (2) to test additional surfactants for the SMR property; and (3) to develop a modeling approach to assess the oil recovery efficiency of SMR in CO{sub 2}-foam on a reservoir scale. The experimental results from the composite cores suggest that the rock heterogeneity has significant effect on two phase (CO{sub 2}/brine) flow behavior in porous media, and that foam can favorably control CO{sub 2} mobility. The numerical modeling results suggest that foam with SMR can substantially increase the sweep efficiency and therefore improve oil recovery.

  1. [Decomposition of herbaceous species in reservoir riparian region of Three Gorges Reservoir under flooding condition].

    PubMed

    Yuan, Qing-Ye; Xie, Zong-Qiang; Yang, Lin-Sen; Xiong, Gao-Ming; Li, Zhao-Jia; Fan, Da-Yong

    2014-08-01

    A total of 10 annuals and perennials of herbaceous species were investigated in reservoir riparian region of Three Gorges Reservoir. The correlations between the plants' nutrient release rate and the substrate composition and structural matter were studied under flooding condition. The decomposition rates of different species differed substantially, with the maximum of Alternanthera philoxeroides (decomposition rate constant k = 0.0228 d(-1)) and the minimum of Microstegium vimineum (k = 0.0029 d(-1)). There was no significant difference in k between annuals and perennials. There was no significant difference in nitrogen and phosphorus contents between annuals and perennials. Paspalum paspaloides and Bidens pilosa released more nutrients into the water than the other species. A. philoxeroides had a higher potential to release nitrogen while it had little effect on water phosphorus compared with the other species. Total N, P contents in the water were negatively correlated with the plants' decomposition rate, initial C content, C:N ratio, lignin:N ratio, and positively correlated with initial contents of K, Ca and N in plants. PMID:25509072

  2. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs

    SciTech Connect

    Grigg, Reid B.; Schechter, David S.; Chang, Shih-Hsien; Tsau, Jyun-Syung; Svec, Robert K.

    2000-02-04

    This project examines three major areas in which CO{sub 2} flooding can be improved: fluid and matrix interactions, conformance control, sweep efficiency, and reservoir simulation for improved oil recovery. This report discusses the activity during the calendar quarter covering October 1, 1999 through December 31, 1999 that covers mostly the second fiscal quarter of the project's third year. Injectivity experiments were performed on two Indian limestone cores. In tests on the first core, a variety of brine, CO{sub 2} WAG, and oil contaminant injection schemes indicated infectivity reduction due to phase conditions and contamination. The results are only quantitative because of plugging and erosion in the core. To date, tests on the second core have investigated the effects of long-term brine stability on the reduction of fluid-rock interaction, in order to quantify fluid effects on infectivity. The authors continue to develop a new approach in reservoir simulation to improve the history matching process on clusters of PCs. The main objective was to improve simulation of complex improved oil recovery methods, such as CO{sub 2}-foam for mobility control and sweep enhancements. Adsorption experiments using circulation and flow-through methods were used to determine the loss of surfactants for economic evaluation. A sacrificial agent, lignosulfonate, was used to reduce the adsorption of the primary foaming agent in both Berea sandstone and Indian limestone. The lignosulfonate has also shown a chromatograph effect, advancing more rapidly through the reservoir, thus initially adsorbing onto the rock before the primary foaming agent arrives. Therefore, considering the simplicity of operation and economics of reducing the cost of expensive surfactant to improve oil recovery, coinjection of lignosulfonate with the primary foaming agent might be a practical approach to consider for field application.

  3. Assessment of Short Term Flood Operation Strategies Using Numerical Weather Prediction Data in YUVACΙK DAM Reservoir, Turkey

    NASA Astrophysics Data System (ADS)

    Uysal, G.; Yavuz, O.; Sensoy, A.; Sorman, A.; Akgun, T.; Gezgin, T.

    2011-12-01

    Yuvacik Dam Reservoir Basin, located in the Marmara region of Turkey with 248 km2 drainage area, has steep topography, mild and rainy climate thus induces high flood potential with fast flow response, especially to early spring and fall precipitation events. Moreover, the basin provides considerable snowmelt contribution to the streamflow during melt season since the elevation ranges between 80 - 1548 m. The long term strategies are based on supplying annual demand of 142 hm3 water despite a relatively small reservoir capacity of 51 hm3. This situation makes short term release decisions as the challenging task regarding the constrained downstream safe channel capacity especially in times of floods. Providing the demand of 1.5 million populated city of Kocaeli is the highest priority issue in terms of reservoir management but risk optimization is also required due to flood regulation. Although, the spillway capacity is 1560 m3/s, the maximum amount of water to be released is set as 100 m3/s by the regional water authority taking into consideration the downstream channel capacity which passes through industrial region of the city. The reservoir is a controlled one and it is possible to hold back the 15 hm3 additional water by keeping the gates closed. Flood regulation is set to achieve the maximum possible flood attenuation by using the full flood-control zone capacity in the reservoir before making releases in excess of the downstream safe-channel capacity. However, the operators still need to exceed flood regulation zones to take precautions for drought summer periods in order to supply water without any shortage that increases the risk in times of flood. Regarding to this circumstances, a hydrological model integrated reservoir modeling system, is applied to account for the physical behavior of the system. Hence, this reservoir modeling is carried out to analyze both previous decisions and also the future scenarios as a decision support tool for operators. In the

  4. ACOUSTIC IMAGING OF SEDIMENT IMPOUNDED WITHIN USDA-NRCS FLOOD CONTROL DAMS, WISCONSIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1948, the USDA-NRCS has constructed nearly 11,000 upstream flood control dams in 2000 watersheds in 47 states, most with a design life of 50 years. But many of these reservoirs are filling with sediment. At the direct request of the USDA-NRCS in Wisconsin, two reservoirs, White Mound Lake an...

  5. Flood hydrology and dam-breach hydraulic analyses of five reservoirs in Colorado

    USGS Publications Warehouse

    Stevens, Michael R.; Hoogestraat, Galen K.

    2013-01-01

    The U.S. Department of Agriculture Forest Service has identified hazard concerns for areas downstream from five Colorado dams on Forest Service land. In 2009, the U.S. Geological Survey, in cooperation with the Forest Service, initiated a flood hydrology analysis to estimate the areal extent of potential downstream flood inundation and hazard to downstream life, property, and infrastructure if dam breach occurs. Readily available information was used for dam-breach assessments of five small Colorado reservoirs (Balman Reservoir, Crystal Lake, Manitou Park Lake, McGinnis Lake, and Million Reservoir) that are impounded by an earthen dam, and no new data were collected for hydraulic modeling. For each reservoir, two dam-breach scenarios were modeled: (1) the dam is overtopped but does not fail (break), and (2) the dam is overtopped and dam-break occurs. The dam-breach scenarios were modeled in response to the 100-year recurrence, 500-year recurrence, and the probable maximum precipitation, 24-hour duration rainstorms to predict downstream flooding. For each dam-breach and storm scenario, a flood inundation map was constructed to estimate the extent of flooding in areas of concern downstream from each dam. Simulation results of the dam-break scenarios were used to determine the hazard classification of the dam structure (high, significant, or low), which is primarily based on the potential for loss of life and property damage resulting from the predicted downstream flooding.

  6. A Framework for Flood Risk Analysis and Benefit Assessment of Flood Control Measures in Urban Areas

    PubMed Central

    Li, Chaochao; Cheng, Xiaotao; Li, Na; Du, Xiaohe; Yu, Qian; Kan, Guangyuan

    2016-01-01

    Flood risk analysis is more complex in urban areas than that in rural areas because of their closely packed buildings, different kinds of land uses, and large number of flood control works and drainage systems. The purpose of this paper is to propose a practical framework for flood risk analysis and benefit assessment of flood control measures in urban areas. Based on the concept of disaster risk triangle (hazard, vulnerability and exposure), a comprehensive analysis method and a general procedure were proposed for urban flood risk analysis. Urban Flood Simulation Model (UFSM) and Urban Flood Damage Assessment Model (UFDAM) were integrated to estimate the flood risk in the Pudong flood protection area (Shanghai, China). S-shaped functions were adopted to represent flood return period and damage (R-D) curves. The study results show that flood control works could significantly reduce the flood risk within the 66-year flood return period and the flood risk was reduced by 15.59%. However, the flood risk was only reduced by 7.06% when the flood return period exceeded 66-years. Hence, it is difficult to meet the increasing demands for flood control solely relying on structural measures. The R-D function is suitable to describe the changes of flood control capacity. This frame work can assess the flood risk reduction due to flood control measures, and provide crucial information for strategy development and planning adaptation. PMID:27527202

  7. A Framework for Flood Risk Analysis and Benefit Assessment of Flood Control Measures in Urban Areas.

    PubMed

    Li, Chaochao; Cheng, Xiaotao; Li, Na; Du, Xiaohe; Yu, Qian; Kan, Guangyuan

    2016-01-01

    Flood risk analysis is more complex in urban areas than that in rural areas because of their closely packed buildings, different kinds of land uses, and large number of flood control works and drainage systems. The purpose of this paper is to propose a practical framework for flood risk analysis and benefit assessment of flood control measures in urban areas. Based on the concept of disaster risk triangle (hazard, vulnerability and exposure), a comprehensive analysis method and a general procedure were proposed for urban flood risk analysis. Urban Flood Simulation Model (UFSM) and Urban Flood Damage Assessment Model (UFDAM) were integrated to estimate the flood risk in the Pudong flood protection area (Shanghai, China). S-shaped functions were adopted to represent flood return period and damage (R-D) curves. The study results show that flood control works could significantly reduce the flood risk within the 66-year flood return period and the flood risk was reduced by 15.59%. However, the flood risk was only reduced by 7.06% when the flood return period exceeded 66-years. Hence, it is difficult to meet the increasing demands for flood control solely relying on structural measures. The R-D function is suitable to describe the changes of flood control capacity. This frame work can assess the flood risk reduction due to flood control measures, and provide crucial information for strategy development and planning adaptation. PMID:27527202

  8. Land Use Land Cover Impact on Probable Maximum Flood and Sedimentation for Artificial Reservoirs: A Case Study in Western US

    NASA Astrophysics Data System (ADS)

    Yigzaw, W. Y.; Hossain, F.

    2014-12-01

    Unanticipated peak inflows that can exceed the inflow design flood (IDF) for spillways and result in possible storage loss in reservoirs from increased sedimentation rates lead to a greater risk for downstream floods. Probable maximum precipitation (PMP) and probable maximum flood (PMF) are mostly used to determine IDF. Any possible change of PMP and PMF due to future land use and land cover (LULC) change therefore requires a methodical investigation. However, the consequential sediment yield, due to altered precipitation and flow patterns into the reservoir has not been addressed in literature. Thus, this study answers the following question: "What is the combined impact of a modified PMP on PMF and sediment yield for an artificial reservoir? The Owyhee dam of Owyhee River watershed (ORW) in Oregon is selected as a case study area for understanding the impact of LULC change on PMF and sedimentation rates. Variable Infiltration Capacity (VIC) is used for simulating stream flow (PMF) and the Revised Universal Soil Loss Equation (RUSLE) to estimate sediment yield over ORW as a result of change in precipitation intensity and LULC. Scenarios that represent pre-Owyhee dam (Pre-Dam) and post Owyhee dam (Non-Irrigation, Control, 1992, 2001, 2006) are used to simulate PMF's and consequential sediment yield. Peak PMF result for Pre-Dam scenarios is found to increase by 26m3s-1 (1%) and 81m3s-1 (3%) from Non-Irrigation and Control scenario, respectively. Considering only LULC change, sediment yield decreased over ORW due to the transformation of LULC from grassland to shrubland (from Pre-Dam period to the post-Dam years). However, increase in precipitation intensity caused a significant (0.1% storage loss over 21days storm period) increase in sediment yield resulting in largely reservoir sedimentation. This study underscores the need to consider future impact of LULC change on IDF calculation as well as sedimentation rates for more robust reservoir operations and planning.

  9. Application of hydrological models for flood forecasting and flood control in India and Bangladesh

    NASA Astrophysics Data System (ADS)

    Refsgaard, J. C.; Havnø, K.; Ammentorp, H. C.; Verwey, A.

    A general mathematical modelling system for real-time flood forecasting and flood control planning is described. The system comprises a lumped conceptual rainfall-runoff model, a hydrodynamic model for river routing, reservoir and flood plain simulation, an updating procedure for real-time operation and a comprehensive data management system. The system is presently applied for real-time forecasting of the two 20 000 km 2 (Yamuna and Damodar) catchments in India as well as for flood control modelling at the same two catchments in India. In another project the system is being established for the entire Bangladesh with a coarse discretization and for the South East Region of Bangladesh with a fine model discretization. The objectives of the modelling application in Bangladesh are to enable predictions of the effects of alternative river regulation structures in terms of changes in water levels, inundations, siltration and salinity. The modelling system has been transferred to the Central Water Commission of India and the Master Plan Organization of Bangladesh in connection with comprehensive training programmes. The models are presently being operated by Indian and Bangladeshi engineers in the two countries.

  10. The tele-connections of long duration floods and their implications for dynamically updating the Flood Control Pool

    NASA Astrophysics Data System (ADS)

    Devineni, Naresh; Najibi, Nasser; Lall, Upmanu

    2016-04-01

    Traditional approaches to flood risk assessment are typically indexed to an instantaneous peak flow event at a specific recording gage on a river, and then extrapolated through hydraulic modeling of that peak flow to the potential area that is likely to be inundated. However, property losses tend to be determined as much by the duration and volume of flooding as by the depth and velocity of inundation. We argue that the existing notion of a flood risk assessment and consequent reservoir flood control operations needs to be revisited, especially for floods due to persistent rainfall (>30 day duration). Our interest lies in explicitly understanding the dependence of the likelihood or frequency and intensity of extreme regional floods on a causal chain of ocean-atmosphere processes whose slow variation and regime-like changes translate into significant and persistent changes in the probability of major floods in the large river basins. An understanding and mapping of these factors into a dynamic risk framework is important for establishing a process by which flood risk for large basins could be systematically updated reflecting changing climate conditions, whether due to human influence, or as part of the natural cycles of climate variation. In this study, we developed an inference system for climate informed flood risk assessment using an integrated statistical modeling approach. We first develop multivariate flood attributes and classify their characteristic spatial variability using the hierarchical clustering approach. Depending on the flood event type, different rainfall inducing mechanisms (e.g. tropical storm, local convection, frontal system, recurrent tropical waves) may be involved with characteristic spatial scales and statistical properties. Hence, we identify the antecedent rainfall conditions for the flood types and map their corresponding specific atmospheric circulation patterns using compositing of the NCEP/NCAR reanalysis data and the storm tracks

  11. Multireservoir real-time operations for flood control using balanced water level index method.

    PubMed

    Wei, Chih-Chiang; Hsu, Nien-Sheng

    2008-09-01

    This paper presents a real-time simulation-optimization operation procedure for determining the reservoir releases at each time step during a flood. The proposed procedure involves two models, i.e., a hydrological forecasting model and a reservoir operation model. In the reservoir operation model, this paper compares two flood-control operation strategies for a multipurpose multireservoir system. While Strategy 1 is the real-time joint reservoir operations without using the balanced water level index (BWLI) method, Strategy 2 involves real-time joint reservoir operations using the BWLI method. The two strategies presented are formulated as mixed-integer linear programming (MILP) problems. The idea of using the BWLI method is derived from the HEC-5 program developed by the US Army Corps of Engineers. The proposed procedure has been applied to the Tanshui River Basin system in Taiwan using the 6h ahead forecast data of six typhoons. A comparison of the results obtained from the two strategies reveals that Strategy 2 performs much better than Strategy 1 in determining the reservoir real-time releases throughout the system during flood emergencies in order to minimize flooding, while maintaining all reservoirs in the system in balance if possible. Consequently, the proposed model using the BWLI method demonstrates its effectiveness in estimating real-time releases. PMID:17923249

  12. Numerical Well Testing Interpretation Model and Applications in Crossflow Double-Layer Reservoirs by Polymer Flooding

    PubMed Central

    Guo, Hui; He, Youwei; Li, Lei; Du, Song; Cheng, Shiqing

    2014-01-01

    This work presents numerical well testing interpretation model and analysis techniques to evaluate formation by using pressure transient data acquired with logging tools in crossflow double-layer reservoirs by polymer flooding. A well testing model is established based on rheology experiments and by considering shear, diffusion, convection, inaccessible pore volume (IPV), permeability reduction, wellbore storage effect, and skin factors. The type curves were then developed based on this model, and parameter sensitivity is analyzed. Our research shows that the type curves have five segments with different flow status: (I) wellbore storage section, (II) intermediate flow section (transient section), (III) mid-radial flow section, (IV) crossflow section (from low permeability layer to high permeability layer), and (V) systematic radial flow section. The polymer flooding field tests prove that our model can accurately determine formation parameters in crossflow double-layer reservoirs by polymer flooding. Moreover, formation damage caused by polymer flooding can also be evaluated by comparison of the interpreted permeability with initial layered permeability before polymer flooding. Comparison of the analysis of numerical solution based on flow mechanism with observed polymer flooding field test data highlights the potential for the application of this interpretation method in formation evaluation and enhanced oil recovery (EOR). PMID:25302335

  13. Numerical well testing interpretation model and applications in crossflow double-layer reservoirs by polymer flooding.

    PubMed

    Yu, Haiyang; Guo, Hui; He, Youwei; Xu, Hainan; Li, Lei; Zhang, Tiantian; Xian, Bo; Du, Song; Cheng, Shiqing

    2014-01-01

    This work presents numerical well testing interpretation model and analysis techniques to evaluate formation by using pressure transient data acquired with logging tools in crossflow double-layer reservoirs by polymer flooding. A well testing model is established based on rheology experiments and by considering shear, diffusion, convection, inaccessible pore volume (IPV), permeability reduction, wellbore storage effect, and skin factors. The type curves were then developed based on this model, and parameter sensitivity is analyzed. Our research shows that the type curves have five segments with different flow status: (I) wellbore storage section, (II) intermediate flow section (transient section), (III) mid-radial flow section, (IV) crossflow section (from low permeability layer to high permeability layer), and (V) systematic radial flow section. The polymer flooding field tests prove that our model can accurately determine formation parameters in crossflow double-layer reservoirs by polymer flooding. Moreover, formation damage caused by polymer flooding can also be evaluated by comparison of the interpreted permeability with initial layered permeability before polymer flooding. Comparison of the analysis of numerical solution based on flow mechanism with observed polymer flooding field test data highlights the potential for the application of this interpretation method in formation evaluation and enhanced oil recovery (EOR). PMID:25302335

  14. Biological implications of the 1996 controlled flood

    NASA Astrophysics Data System (ADS)

    Valdez, Richard A.; Shannon, Joseph P.; Blinn, Dean W.

    The 1996 controlled flood provided evidence that elevated releases from Glen Canyon Dam can enhance short-term primary and secondary production of aquatic resources of the Colorado River in Grand Canyon National Park. The flood scoured substantial proportions of benthic algae and macroinvertebrates and removed fine sediments from the channel, which ultimately stimulated primary productivity and consumer biomass. Channel margin sand deposits buried riparian vegetation and leaf litter, entraining nutrients for later incorporation into the upper trophic levels. The flood restructured high-stage sand bars and associated eddy return channels (i.e., backwaters used as nurseries by native and non-native fish), but many were short-lived because reattachment bars were eroded shortly after the flood. The flood was of insufficient magnitude to permanently suppress non-native fish populations, even though there was significant population depletion at some collecting sites. Pre-spawning aggregations, spawning ascents of tributaries, and habitat use by native fishes were unaffected by the flood. Adult rainbow trout (Oncorhynchus mykiss) in the Lees Ferry tailwater fishery were also unaffected, but the proportion of juveniles <152 mm total length decreased by 10% a strong year class following the flood indicated replacement through successful reproduction.

  15. Controls on flood and sediment wave propagation

    NASA Astrophysics Data System (ADS)

    Bakker, Maarten; Lane, Stuart N.; Costa, Anna; Molnar, Peter

    2015-04-01

    The understanding of flood wave propagation - celerity and transformation - through a fluvial system is of generic importance for flood forecasting/mitigation. In association with flood wave propagation, sediment wave propagation may induce local erosion and sedimentation, which will affect infrastructure and riparian natural habitats. Through analysing flood and sediment wave propagation, we gain insight in temporal changes in transport capacity (the flood wave) and sediment availability and transport (the sediment wave) along the river channel. Heidel (1956) was amongst the first to discuss the progressive lag of sediment concentration behind the corresponding flood wave based on field measurements. Since then this type of hysteresis has been characterized in a number of studies, but these were often based on limited amount of floods and measurement sites, giving insufficient insight into associated forcing mechanisms. Here, as part of a project concerned with the hydrological and geomorphic forcing of sediment transfer processes in alpine environments, we model the downstream propagation of short duration, high frequency releases of water and sediment (purges) from a flow intake in the Borgne d'Arolla River in south-west Switzerland. A total of >50 events were measured at 1 minute time intervals using pressure transducers and turbidity probes at a number of sites along the river. We show that flood and sediment wave propagation can be well represented through simple convection diffusion models. The models are calibrated/validated to describe the set of measured waves and used to explain the observed variation in wave celerity and diffusion. In addition we explore the effects of controlling factors including initial flow depth, flood height, flood duration, bed roughness, bed slope and initial sediment concentration, on the wave propagation processes. We show that the effects of forcing mechanisms on flood and sediment wave propagation will lead to different

  16. Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

    PubMed

    Yang, Fan; Wang, Yong; Chan, Zhulong

    2014-01-01

    The establishment of riparian protection forests in the Three Gorges Reservoir (TGR) is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ). Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides) and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora) might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress and recover well

  17. Perspectives on Screening Winter-Flood-Tolerant Woody Species in the Riparian Protection Forests of the Three Gorges Reservoir

    PubMed Central

    Yang, Fan; Wang, Yong; Chan, Zhulong

    2014-01-01

    The establishment of riparian protection forests in the Three Gorges Reservoir (TGR) is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ). Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides) and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora) might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress and recover well

  18. Fire flood method for recovering petroleum from oil reservoirs of low permeability and temperature

    DOEpatents

    Kamath, Krishna

    1984-08-14

    The present invention is directed to a method of enhanced oil recovery by fire flooding petroleum reservoirs characterized by a temperature of less than the critical temperature of carbon dioxide, a pore pressure greater than the saturated vapor pressure of carbon dioxide at said temperature (87.7.degree. F. at 1070 psia), and a permeability in the range of about 20 to 100 millidarcies. The in situ combustion of petroleum in the reservoir is provided by injecting into the reservoir a combustion supporting medium consisting essentially of oxygen, ozone, or a combination thereof. The heat of combustion and the products of this combustion which consist essentially of gaseous carbon dioxide and water vapor sufficiently decrease the viscosity of oil adjacent to fire front to form an oil bank which moves through the reservoir towards a recovery well ahead of the fire front. The gaseous carbon dioxide and the water vapor are driven into the reservoir ahead of the fire front by pressure at the injection well. As the gaseous carbon dioxide cools to less than about 88.degree. F. it is converted to liquid which is dissolved in the oil bank for further increasing the mobility thereof. By using essentially pure oxygen, ozone, or a combination thereof as the combustion supporting medium in these reservoirs the permeability requirements of the reservoirs are significantly decreased since the liquid carbon dioxide requires substantially less voidage volume than that required for gaseous combustion products.

  19. Scale-up of miscible flood processes for heterogeneous reservoirs. Final report

    SciTech Connect

    Orr, F.M. Jr.

    1996-04-01

    Results of a wide-ranging investigation of the scaling of gas injection processes are reported. The research examines how the physical mechanisms at work during a gas injection project interact to determine process performance. In particular, the authors examine: the interactions of equilibrium phase behavior and two-phase flow that determine local displacement efficiency and minimum miscibility pressure, the combined effects of viscous fingering, gravity segregation and heterogeneity that control sweep efficiency in 2- and 3-dimensional porous media, the use of streamtube/streamline methods to create very efficient simulation technique for multiphase compositional displacements, the scaling of viscous, capillary and gravity forces for heterogeneous reservoirs, and the effects of the thin films and spreading behavior on three-phase flow. The following key results are documented: rigorous procedures for determination of minimum miscibility pressure (MMP) or minimum miscibility enrichment (MME) for miscibility have been developed for multicomponent systems; the complex dependence of MMP`s for nitrogen/methane floods on oil and injection gas composition observed experimentally is explained for the first time; the presence of layer-like heterogeneities strongly influences the interplay of gravity segregation and viscous fingering, as viscous fingers adapt to preferential flow paths and low permeability layers restrict vertical flow; streamtube/streamline simulation techniques are demonstrated for a variety of injection processes in 2 and 3 dimensions; quantitative scaling estimates for the transitions from capillary-dominated to gravity-dominated to viscous-dominated flows are reported; experimental results are given that demonstrate that high pressure CO{sub 2} can be used to generate low IFT gravity drainage in fractured reservoirs if fractures are suitably connected; and the effect of wetting and spreading behavior on three-phase flow is described. 209 refs.

  20. RAPID Assessment of Extreme Reservoir Sedimentation Resulting from the September 2013 Flood, North St. Vrain Creek, CO

    NASA Astrophysics Data System (ADS)

    Rathburn, S. L.; McElroy, B. J.; Wohl, E.; Sutfin, N. A.; Huson, K.

    2014-12-01

    During mid-September 2013, approximately 360 mm of precipitation fell in the headwaters of the North St. Vrain drainage basin, Front Range, CO. Debris flows on steep hillslopes and extensive flooding along North St. Vrain Creek resulted in extreme sedimentation within Ralph Price Reservoir, municipal water supply for the City of Longmont. The event allows comparison of historical sedimentation with that of an unusually large flood because 1) no reservoir flushing has been conducted since dam construction, 2) reservoir stratigraphy chronicles uninterrupted delta deposition, and 3) this is the only on-channel reservoir with unimpeded, natural sediment flux from the Continental Divide to the mountain front in a basin with no significant historic flow modifications and land use impacts. Assessing the flood-related sedimentation prior to any dredging activities included coring the reservoir delta, a bathymetric survey of the delta, resistivity and ground penetrating radar surveys of the subaerial inlet deposit, and surveying tributary deposits. Over the 44-year life of the reservoir, two-thirds of the delta sedimentation is attributed to extreme discharges from the September 2013 storm. Total storm-derived reservoir sedimentation is approximately 275,000 m3, with 81% of that within the gravel-dominated inlet and 17% in the delta. Volumes of deposition within reservoir tributary inlets is negatively correlated with contributing area, possibly due to a lack of storage in these small basins (1-5 km2). Flood-related reservoir sedimentation will be compared to other research quantifying volumes from slope failures evident on post-storm lidar. Analysis of delta core samples will quantify organic carbon flux associated with the extreme discharge and develop a chronology of flood and fire disturbances for North St. Vrain basin. Applications of similar techniques are planned for two older Front Range reservoirs affected by the September flooding to fill knowledge gaps about

  1. Characterization of microbial diversity and community in water flooding oil reservoirs in China.

    PubMed

    Zhao, Lingxia; Ma, Ting; Gao, Mengli; Gao, Peike; Cao, Meina; Zhu, Xudong; Li, Guoqiang

    2012-10-01

    The diversity and distribution of bacterial and archaeal communities in four different water flooding oil reservoirs with different geological properties were investigated using 16S rDNA clone library construction method. Canonical correspondence analysis was used to analyze microbial community clustering and the correlation with environmental factors. The results indicated that the diversity and abundance in the bacterial communities were significantly higher than the archaeal communities, while both of them had high similarity within the communities respectively. Phylogenetic analysis showed that of compositions of bacterial communities were distinctly different both at phylum and genus level. Proteobacteria dominated in each bacterial community, ranging from 61.35 to 75.83 %, in which α-proteobacteria and γ-proteobacteria were the main groups. In comparison to bacterial communities, the compositions of archaeal communities were similar at phylum level, while varied at genus level, and the dominant population was Methanomicrobia, ranging from 65.91 to 92.74 % in the single oil reservoir. The factor that most significantly influenced the microbial communities in these reservoirs was found to be temperature. Other environmental factors also influenced the microbial communities but not significantly. It is therefore assumed that microbial communities are formed by an accumulated effect of several factors. These results are essential for understanding ecological environment of the water flooding oil reservoirs and providing scientific guidance to the performance of MEOR technology. PMID:22806743

  2. Optimal and centralized reservoir management for drought and flood protection via Stochastic Dual Dynamic Programming on the Upper Seine-Aube River system

    NASA Astrophysics Data System (ADS)

    Chiavico, Mattia; Raso, Luciano; Dorchies, David; Malaterre, Pierre-Olivier

    2015-04-01

    Seine river region is an extremely important logistic and economic junction for France and Europe. The hydraulic protection of most part of the region relies on four controlled reservoirs, managed by EPTB Seine-Grands Lacs. Presently, reservoirs operation is not centrally coordinated, and release rules are based on empirical filling curves. In this study, we analyze how a centralized release policy can face flood and drought risks, optimizing water system efficiency. The optimal and centralized decisional problem is solved by Stochastic Dual Dynamic Programming (SDDP) method, minimizing an operational indicator for each planning objective. SDDP allows us to include into the system: 1) the hydrological discharge, specifically a stochastic semi-distributed auto-regressive model, 2) the hydraulic transfer model, represented by a linear lag and route model, and 3) reservoirs and diversions. The novelty of this study lies on the combination of reservoir and hydraulic models in SDDP for flood and drought protection problems. The study case covers the Seine basin until the confluence with Aube River: this system includes two reservoirs, the city of Troyes, and the Nuclear power plant of Nogent-Sur-Seine. The conflict between the interests of flood protection, drought protection, water use and ecology leads to analyze the environmental system in a Multi-Objective perspective.

  3. Phosphorous control in a eutrophied reservoir.

    PubMed

    Márquez-Pacheco, H; Hansen, A M; Falcón-Rojas, A

    2013-12-01

    Water in lakes and reservoirs accumulate phosphorous (P) from both internal and external loads. The external P load (EPL) coming from the watershed is considered to be the main cause of eutrophication of water bodies, and control strategies therefore focus on its reduction. However, algae blooms and anoxic conditions often continue even after EPL have been controlled, being the internal P load (IPL) originating from the sediment the main sources of P. To assess the efficiency of the adsorbent Phoslock (a modified bentonite) in controlling P concentrations in water and immobilize releasable P in sediments, mesocosm trials were carried out in a eutrophied reservoir and a model was described and applied that determines the amount of adsorbent and the application frequency necessary to control P concentrations in a eutrophied reservoir. The mesocosm trials confirm that Phoslock reduced P concentrations to or below the limits that define water in mesotrophic state, in approximately 2 weeks. The modeling results suggest that periodic reapplications of the adsorbent are required, unless EPL is reduced by 36 %, which allows the P concentrations in the water column to be constant. Such reduction in EPL would allow future applications of the adsorbent to be required only for control of IPL. The developed model allows planning remediation actions by determining quantities and frequencies for application of adsorbents for P control in eutrophied lakes and reservoirs. PMID:23589273

  4. Numerical simulation of catastrophic flood: the case study of hypothetical failure of the Bielkowo hydro-power plant reservoir

    NASA Astrophysics Data System (ADS)

    Szydłowski, Michał; Szpakowski, Wojciech; Zima, Piotr

    2013-10-01

    The numerical modeling of flood wave propagation following the hypothetical breaks of the embankments of the Bielkowo hydro-power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland has been presented. The results of computations were used to estimate the parameters of the flood waves, which are indispensable for the flood zone determination and mapping and then for the flood risk analysis. When estimating the reach and area of the inundation, related to the embankments failures, digital terrain model, and mathematical model of flood wave propagation are necessary. For the numerical simulations of flood, the mathematical model of free surface, two-dimensional unsteady water flow was applied. Four locations of potential breaks of the reservoir embankments were considered. The computed flood zones were presented on the flood hazard maps. The maps have been used by the local authorities and the dam owner to manage the flood risk related to hydro-power plants operations on the Radunia River. This type of research has been done for the first time for the water plant managed by the ENERGA Elektrownie Straszyn.

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

    USGS Publications Warehouse

    Rydlund, Paul H.

    2006-01-01

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

  6. Post waterflood CO{sub 2} miscible flood in light oil, fluvial-dominated deltaic reservoir. FY 1993 annual report

    SciTech Connect

    Davis, D.W.

    1995-03-01

    The project is a Class 1 DOE-sponsored field demonstration project of a CO{sub 2} miscible flood project at the Port Neches Field in Orange County, Texas. The project will determine the recovery efficiency of CO{sub 2} flooding a waterflooded and a partial waterdrive sandstone reservoir at a depth of 5,800. The project will also evaluate the use of a horizontal CO{sub 2} injection well placed at the original oil-water contact of the waterflooded reservoir. A PC-based reservoir screening model will be developed by Texaco`s research lab in Houston and Louisiana State University will assist in the development of a database of fluvial-dominated deltaic reservoirs where CO{sub 2} flooding may be applicable. This technology will be transferred throughout the oil industry through a series of technical papers and industry open forums.

  7. How to update design floods after the construction of small reservoirs and check dams: A case study from the Daqinghe river basin, China

    NASA Astrophysics Data System (ADS)

    Li, Jianzhu; Sun, Huafeng; Feng, Ping

    2016-05-01

    Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10-200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10-200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams.

  8. How to update design floods after the construction of small reservoirs and check dams: A case study from the Daqinghe river basin, China

    NASA Astrophysics Data System (ADS)

    Li, Jianzhu; Sun, Huafeng; Feng, Ping

    2016-06-01

    Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10-200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10-200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams.

  9. Daily Time Step Refinement of Optimized Flood Control Rule Curves for a Global Warming Scenario

    NASA Astrophysics Data System (ADS)

    Lee, S.; Fitzgerald, C.; Hamlet, A. F.; Burges, S. J.

    2009-12-01

    Pacific Northwest temperatures have warmed by 0.8 °C since 1920 and are predicted to further increase in the 21st century. Simulated streamflow timing shifts associated with climate change have been found in past research to degrade water resources system performance in the Columbia River Basin when using existing system operating policies. To adapt to these hydrologic changes, optimized flood control operating rule curves were developed in a previous study using a hybrid optimization-simulation approach which rebalanced flood control and reservoir refill at a monthly time step. For the climate change scenario, use of the optimized flood control curves restored reservoir refill capability without increasing flood risk. Here we extend the earlier studies using a detailed daily time step simulation model applied over a somewhat smaller portion of the domain (encompassing Libby, Duncan, and Corra Linn dams, and Kootenai Lake) to evaluate and refine the optimized flood control curves derived from monthly time step analysis. Moving from a monthly to daily analysis, we found that the timing of flood control evacuation needed adjustment to avoid unintended outcomes affecting Kootenai Lake. We refined the flood rule curves derived from monthly analysis by creating a more gradual evacuation schedule, but kept the timing and magnitude of maximum evacuation the same as in the monthly analysis. After these refinements, the performance at monthly time scales reported in our previous study proved robust at daily time scales. Due to a decrease in July storage deficits, additional benefits such as more revenue from hydropower generation and more July and August outflow for fish augmentation were observed when the optimized flood control curves were used for the climate change scenario.

  10. DEVELOPMENT OF MORE-EFFICIENT GAS FLOODING APPLICABLE TO SHALLOW RESERVOIRS

    SciTech Connect

    William R. Rossen; Russell T. Johns; Gary A. Pope

    2003-08-21

    The objective of this research is to widen the applicability of gas flooding to shallow oil reservoirs by reducing the pressure required for miscibility using gas enrichment and increasing sweep efficiency with foam. Task 1 examines the potential for improved oil recovery with enriched gases. Subtask 1.1 examines the effect of dispersion processes on oil recovery and the extent of enrichment needed in the presence of dispersion. Subtask 1.2 develops a fast, efficient method to predict the extent of enrichment needed for crude oils at a given pressure. Task 2 develops improved foam processes to increase sweep efficiency in gas flooding. Subtask 2.1 comprises mechanistic experimental studies of foams with N2 gas. Subtask 2.2 conducts experiments with CO{sub 2} foam. Subtask 2.3 develops and applies a simulator for foam processes in field application.

  11. 33 CFR 209.300 - Flood control regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.300 Flood control regulations. (a) Regulations for the operation and maintenance of local flood protection works approved by the Secretary of the Army under...

  12. 33 CFR 209.300 - Flood control regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.300 Flood control regulations. (a) Regulations for the operation and maintenance of local flood protection works approved by the Secretary of the Army under...

  13. 33 CFR 209.300 - Flood control regulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.300 Flood control regulations. (a) Regulations for the operation and maintenance of local flood protection works approved by the Secretary of the Army under...

  14. 33 CFR 209.300 - Flood control regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.300 Flood control regulations. (a) Regulations for the operation and maintenance of local flood protection works approved by the Secretary of the Army under...

  15. 33 CFR 209.300 - Flood control regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.300 Flood control regulations. (a) Regulations for the operation and maintenance of local flood protection works approved by the Secretary of the Army under...

  16. A novel recovery mechanism for polymer flooding in gravity-dominated viscous-oil reservoirs

    SciTech Connect

    Goodyear, S.G.; Mead, B.J.; Woods, C.L.

    1995-11-01

    The viscous oil and poor vertical sweep make these reservoirs possible targets for IOR with polymers. This study shows that polymer incremental recoveries can be high, well within the range of potential economic viability. The incremental recovery mechanism is not the usual improved Buckley-Leverett sweep efficiency resulting from correction of an adverse displacement ratio. A novel recovery mechanism is identified in which the polymer increases the ratio of viscous to gravity forces, reducing the water slumping. This leads to improved vertical sweep, recovering oil from regions of high oil saturation at the top of the reservoir. They simulated polymer flooding including temperature effects. Comparison of waterflood simulations including temperature effects with conventional isothermal simulations shows that, counter to normal expectations, isothermal simulations can underpredict recovery by >10%.

  17. Microbial diversity and abundance in the Xinjiang Luliang long-term water-flooding petroleum reservoir

    PubMed Central

    Gao, Peike; Tian, Huimei; Li, Guoqiang; Sun, Hongwen; Ma, Ting

    2015-01-01

    Microbial populations associated with microbial enhanced oil recovery (MEOR) and their abundance in the Xinjiang Luliang water-flooding petroleum reservoir were investigated using 16S rRNA, nitrate reductases, dissimilatory sulfate reductase, and methyl coenzyme-M reductase-encoded genes to provide ecological information for the potential application of MEOR. 16S rRNA gene miseq sequencing revealed that this reservoir harbored large amounts of taxa, including 155 bacterial and 7 archeal genera. Among them, Arcobacter, Halomonas, Marinobacterium, Marinobacter, Sphingomonas, Rhodococcus, Pseudomonas, Dietzia, Ochrobactrum, Hyphomonas, Acinetobacter, and Shewanella were dominant, and have the potential to grow using hydrocarbons as carbon sources. Metabolic gene clone libraries indicated that the nitrate-reducing bacteria (NRB) mainly belonged to Pseudomonas, Azospirillum, Bradyrhizobium, Thauera, Magnetospirillum, Sinorhizobium, Azoarcus, and Rhodobacter; the sulfate-reducing bacteria (SRB) were Desulfarculus, Desulfomonile, Desulfosarcina, Desulfotignum, Desulfacinum, Desulfatibacillum, Desulfatibacillum, Desulfomicrobium, and Desulfovibrio; while the methanogens were archaea and belonged to Methanomethylovorans, Methanosaeta, Methanococcus, Methanolobus, and Methanobacterium. Real-time quantitative PCR analysis indicated that the number of bacterial 16S rRNA reached 106 copies/mL, while the metabolic genes of NRB, SRB, and methanogens reached 104 copies/mL. These results show that the Luliang reservoir has abundant microbial populations associated with oil recovery, suggesting that the reservoir has potential for MEOR. PMID:25641701

  18. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Altus Dam and Reservoir, North..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.26 Altus Dam and Reservoir... Dam and Reservoir in the interest of flood control as follows: (a) Flood control storage in...

  19. 33 CFR 208.33 - Cheney Dam and Reservoir, North Fork of Ninnescah River, Kans.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Cheney Dam and Reservoir, North..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.33 Cheney Dam and Reservoir... the Cheney Dam and Reservoir in the interest of flood control as follows: (a) Flood control storage...

  20. 33 CFR 208.33 - Cheney Dam and Reservoir, North Fork of Ninnescah River, Kans.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Cheney Dam and Reservoir, North..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.33 Cheney Dam and Reservoir... the Cheney Dam and Reservoir in the interest of flood control as follows: (a) Flood control storage...

  1. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Altus Dam and Reservoir, North..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.26 Altus Dam and Reservoir... Dam and Reservoir in the interest of flood control as follows: (a) Flood control storage in...

  2. 33 CFR 208.33 - Cheney Dam and Reservoir, North Fork of Ninnescah River, Kans.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Cheney Dam and Reservoir, North..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.33 Cheney Dam and Reservoir... the Cheney Dam and Reservoir in the interest of flood control as follows: (a) Flood control storage...

  3. 33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Regulations for use of storage allocated for flood control or navigation and/or project operation at reservoirs subject to prescription of rules and regulations by the Secretary of the Army in the interest of flood control and navigation. 208.11 Section 208.11 Navigation...

  4. [Laboratory evaluation and field trial of activation indigenous microbial displacements in the reservoirs after polymer flooding].

    PubMed

    Le, Jianjun; Bai, Lulu; Wang, Rui; Guo, Menghua; Zhang, Jiyuan; Hou, Zhaowei; Wu, Xiaolin

    2015-07-01

    Most main oilfields in China have already entered a "double high" development stage (high water cut, high recovery degree). To further enhance oil recovery in reservoirs after polymer flooding (RAPFs), an efficient activator formulation for promoting metabolism of endogenous microorganism was studied by aerogenic experiments, physical simulation experiments, electron microscopy scanning and pyrophosphate sequencing. Results show that the activator could activate the endogenous microorganisms in the injected water and make the pressurized gas reach 2 MPa after 60 d static culture of the activator in a high pressure vessel. The oil recovery efficiency of natural core physical simulation flooding can be improved by more than 3.0% (OOIP) in RAPFs when injected 0.35 PV activator with 1.8% mass concentration, and a lot of growth and reproduction of activated endogenous microorganism in the core was observed by electron microscopy scanning. Field trial with 1 injector and 4 producers was carried out in the east of south II block of Sa Nan in December 2011. By monitoring four effective production wells, changes of carbon isotope δ13C (PDB) content of methane and carbon dioxide were -45 per thousand to -54 per thousand and 7 per thousand to 12 per thousand. Compared with east II of Sa Nan block, the oil amount increased by 35.9%, water cut stabled at 94%. The incremental oil was 5 957 t during the three and a half years, which provides an alternative approach for further improving oil recovery in similar reservoirs. PMID:26647588

  5. Microbial diversity in long-term water-flooded oil reservoirs with different in situ temperatures in China

    PubMed Central

    Zhang, Fan; She, Yue-Hui; Chai, Lu-Jun; Banat, Ibrahim M.; Zhang, Xiao-Tao; Shu, Fu-Chang; Wang, Zheng-Liang; Yu, Long-Jiang; Hou, Du-Jie

    2012-01-01

    Water-flooded oil reservoirs have specific ecological environments due to continual water injection and oil production and water recycling. Using 16S rRNA gene clone library analysis, the microbial communities present in injected waters and produced waters from four typical water-flooded oil reservoirs with different in situ temperatures of 25°C, 40°C, 55°C and 70°C were examined. The results obtained showed that the higher the in situ temperatures of the oil reservoirs is, the less the effects of microorganisms in the injected waters on microbial community compositions in the produced waters is. In addition, microbes inhabiting in the produced waters of the four water-flooded oil reservoirs were varied but all dominated by Proteobacteria. Moreover, most of the detected microbes were not identified as indigenous. The objective of this study was to expand the pictures of the microbial ecosystem of water-flooded oil reservoirs. PMID:23094135

  6. The survival of early Earth mantle reservoirs: Evidence from flood basalts

    NASA Astrophysics Data System (ADS)

    Jackson, M. G.

    2011-12-01

    isotopic characteristics to match the predicted composition of a primitive, non-chondritic Earth. Jackson et al. (2010, Nature) reported primitive Nd and Pb isotopic compositions in Baffin Island lavas, which are known to host the highest terrestrial mantle 3He/4He ratios (Kent et al., 2003, Nature; Graham et al., 1998 EPSL). Baffin Island lavas constitute a large igneous province (LIP). Using the wisdom gained from Baffin Island, Jackson and Carlson (2011, Nature) prospected for primitive mantle isotopic characteristics in LIPs globally, and they identified a pervasive signature of non-chondritic primitive mantle 143Nd/144Nd and primitive Pb-isotopic ratios in the largest LIPs: Deccan, Siberia, Ontong Java, Kerguelen and Karoo. The geochemical and petrologic characteristics of a primitive mantle reservoir may explain its ubiquitous presence in LIPs. A primitive reservoir will host higher concentrations of the incompatible radioactive elements than depleted reservoirs, and it will therefore be hotter. Similarly, such a reservoir has never had melt extracted, so it will be more fertile and yield more melt. Therefore, a hotter, more fusible (non-chondritic) primitive mantle source sourcing LIPs may constitute the perfect recipe for flood basalt genesis.

  7. Reservoir Characterization of Bridgeport and Cypress Sandstones in Lawrence Field Illinois to Improve Petroleum Recovery by Alkaline-Surfactant-Polymer Flood

    SciTech Connect

    Seyler, Beverly; Grube, John; Huff, Bryan; Webb, Nathan; Damico, James; Blakley, Curt; Madhavan, Vineeth; Johanek, Philip; Frailey, Scott

    2012-12-21

    were used to better understand porosity and permeability trends in the region and to characterize barriers and define flow units. Diagenetic alterations that impact porosity and permeability include development of quartz overgrowths, sutured quartz grains, dissolution of feldspar grains, formation of clay mineral coatings on grains, and calcite cementation. Many of these alterations are controlled by facies. Mapping efforts identified distinct flow units in the northern part of the field showing that the Pennsylvanian Bridgeport consists of a series of thick incised channel fill sequences. The sandstones are about 75-150 feet thick and typically consist of medium grained and poorly sorted fluvial to distributary channel fill deposits at the base. The sandstones become indistinctly bedded distributary channel deposits in the main part of the reservoir before fining upwards and becoming more tidally influenced near their top. These channel deposits have core permeabilities ranging from 20 md to well over 1000 md. The tidally influenced deposits are more compartmentalized compared to the thicker and more continuous basal fluvial deposits. Fine grained sandstones that are laterally equivalent to the thicker channel type deposits have permeabilities rarely reaching above 250 md. Most of the unrecovered oil in Lawrence Field is contained in Pennsylvanian Age Bridgeport sandstones and Mississippian Age Cypress sandstones. These reservoirs are highly complex and compartmentalized. Detailed reservoir characterization including the development of 3-D geologic and geocellular models of target areas in the field were completed to identify areas with the best potential to recover remaining reserves including unswept and by-passed oil. This project consisted of tasks designed to compile, interpret, and analyze the data required to conduct reservoir characterization for the Bridgeport and Cypress sandstones in pilot areas in anticipation of expanded implementation of ASP flooding in

  8. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II

    SciTech Connect

    Czirr, K.L.; Gaddis, M.P.; Moshell, M.K.

    2002-02-21

    The principle objective of this project is to demonstrate the economic viability and widespread applicability of an innovative reservoir management and carbon dioxide (CO2) flood project development approach for improving CO2 flood project economics in shallow shelf carbonate (SSC) reservoirs.

  9. Comprehensive flood control involving citizens in a Japanese watershed.

    PubMed

    Yamashita, Sampei; Shimatani, Yukihiro; Watanabe, Ryoichi; Moriyama, Toshiyuki; Minagawa, Tomoko; Kakudo, Kumiko; Yamashita, Terukazu

    2013-01-01

    In July 2009, the city of Fukuoka, Japan experienced a flood disaster along the Hii River, which runs through densely populated, concrete-covered areas of the city. The drainage system was overwhelmed and the river overflowed due to heavy rainfall and rapid runoff. The event led citizens in its watershed to plan and implement comprehensive flood control. The plan aims not only to mitigate floods but also to revitalize the river environment and populated communities in urban areas. This study reports the activities led by the citizens. They organized and carried out civic forums, workshops, and fieldwork to share views as to how the flood disaster was caused, how floods in the watershed should be controlled, and how the river environment should be rehabilitated. This study illuminates how people, including the flood victims and municipal engineers, can change drastically and communicate effectively in the course of discussing and implementing the comprehensive flood control measures. PMID:23985508

  10. Improved efficiency of miscible CO2 floods and enhanced prospects for CO2 flooding heterogeneous reservoirs. Final report, April 17, 1991--May 31, 1997

    SciTech Connect

    Grigg, R.B.; Schechter, D.S.

    1998-02-01

    From 1986 to 1996, oil recovery in the US by gas injection increased almost threefold, to 300,000 bbl/day. Carbon dioxide (CO{sub 2}) injection projects make up three-quarters of the 191,139 bbl/day production increase. This document reports experimental and modeling research in three areas that is increasing the number of reservoirs in which CO{sub 2} can profitably enhance oil recovery: (1) foams for selective mobility reduction (SMR) in heterogeneous reservoirs, (2) reduction of the amount of CO{sub 2} required in CO{sub 2} floods, and (3) low interfacial tension (97) processes and the possibility of CO{sub 2} flooding in naturally fractured reservoirs. CO{sub 2} injection under miscible conditions can effectively displace oil, but due to differences in density and viscosity the mobility of CO{sub 2} is higher than either oil or water. High CO{sub 2} mobility causes injection gas to finger through a reservoir, causing such problems as early gas breakthrough, high gas production rates, excessive injection gas recycling, and bypassing of much of the reservoir oil. These adverse effects are exacerbated by increased reservoir heterogeneity, reaching an extreme in naturally fractured reservoirs. Thus, many highly heterogeneous reservoirs have not been considered for CO{sub 2} injection or have had disappointing recoveries. One example is the heterogeneous Spraberry trend in west Texas, where only 10% of its ten billion barrels of original oil in place (OOIP) are recoverable by conventional methods. CO{sub 2} mobility can be reduced by injecting water (brine) alternated with CO{sub 2} (WAG) and then further reduced by adding foaming agents-surfactants. In Task 1, we studied a unique foam property, selective mobility reduction (SMR), that effectively reduces the effects of reservoir heterogeneity. Selective mobility reduction creates a more uniform displacement by decreasing CO{sub 2} mobility in higher permeability zones more than in lower permeability zones.

  11. Evaluation on an original resistivity inversion method of water flooding a conglomerate reservoir based on petrophysical analysis

    NASA Astrophysics Data System (ADS)

    Liu, Renqiang; Duan, Yonggang; Tan, Fengqi; Wang, Guochang; Qin, Jianhua; Neupane, Bhupati

    2015-10-01

    An accurate inversion of original reservoir resistivity is an important problem for waterflood development in oilfields in the middle-late development period. This paper describes the theoretical model of original resistivity recovery for a conglomerate reservoir established by petrophysical models, based on the stratigraphic model of reservoir vertical invasion of the conglomerate reservoir of an oilfield. Likewise two influencing factors of the resistivity change with a water-flooded reservoir were analyzed. The first one is the clay volume decrease due to an injected water wash argillaceous particle and the reservoir resistivity changes are influenced by it, and the other is to inject water to displace crude oil in the pore space leading to the increase of the water-bearing volume. Moreover the conductive ions of the injected water and the original formation water exchange and balance because of their salinity difference, and the reservoir resistivity changes are also influenced by them. Through the analysis of the above influential factors based on the fine identification of conglomerate lithologies the inversion models of three variables, including changes in the amount of clay, the resistivity of the irreducible water and the increase of the water bearing volume, were established by core analysis data, production performance and well logging curves information, and accurately recovered the original reservoir resistivity of the conglomerate. The original oil saturation of the reservoir was calculated according to multiple linear regression models. Finally, the produced index is defined as the difference of the original oil saturation and current oil saturation to the original oil saturation ratio, and it eliminates the effects of conglomerate lithologies and heterogeneity for the quantitative evaluation of flooded layers by the use of the principle of relative value. Compared with traditional flooding sensitive parameters which are oil saturation and water

  12. Incorporating Daily Flood Control Objectives Into a Monthly Stochastic Dynamic Programing Model for a Hydroelectric Complex

    NASA Astrophysics Data System (ADS)

    Druce, Donald J.

    1990-01-01

    A monthly stochastic dynamic programing model was recently developed and implemented at British Columbia (B.C.) Hydro to provide decision support for short-term energy exports and, if necessary, for flood control on the Peace River in northern British Columbia. The model establishes the marginal cost of supplying energy from the B.C. Hydro system, as well as a monthly operating policy for the G.M. Shrum and Peace Canyon hydroelectric plants and the Williston Lake storage reservoir. A simulation model capable of following the operating policy then determines the probability of refilling Williston Lake and possible spill rates and volumes. Reservoir inflows are input to both models in daily and monthly formats. The results indicate that flood control can be accommodated without sacrificing significant export revenue.

  13. A simulation-optimization approach to retrieve reservoir releasing strategies under the trade-off objectives considering flooding, sedimentation, turbidity and water supply during typhoons

    NASA Astrophysics Data System (ADS)

    Huang, C. L.; Hsu, N. S.; Yeh, W. W. G.; You, G. J. Y.

    2014-12-01

    This study develops a simulation-optimization approach for retrieving optimal multi-layer reservoir conjunctive release strategies considering the natural hazards of sedimentation, turbidity and flooding during typhoon invasion. The purposes of the developed approach are: (1) to apply WASP-based fluid dynamic sediment concentration simulation model and the developed extracting method of ideal releasing practice to search the optimal initial solution for optimization; and (2) to construct the replacing sediment concentration simulation model which embedded in the optimization model. In this study, the optimization model is solved by tabu search, and the optimized releasing hydrograph is then used for construction of the decision model. This study applies Adaptive Network-based Fuzzy Inference System (ANFIS) and Real-time Recurrent Learning Neural Network (RTRLNN) as construction tool of the concentration simulation model for total suspended solids. This developed approach is applied to the Shihmen Reservoir basin, Taiwan. The assessment index of operational outcome of multi-purpose multi-layer conjunctive releasing are maximum sediment concentration at Yuan-Shan weir, sediment removed ratio, highest water level at Shan-Yin Bridge, and final water level in Shihmen reservoir. The analyzed and optimizing results shows the following: (1) The multi-layer releasing during the stages before flood coming and before peak flow possess high potential for flood detention and sedimentation control; and during the stages after peak flow, for turbidity control and storage; (2) The ability of error toleration and adaption of ANFIS is superior, so ANFIS-based sediment concentration simulation model surpass RTRLNN-based model on simulating the mechanism and characteristics of sediment transport; and (3) The developed approach can effectively and automatically retrieve the optimal multi-layer releasing strategies under the trade-off control between flooding, sedimentation, turbidity

  14. Experimental Research on Profile Control for Oil Displacement by Functional Polymer in Low Permeability Fractured Reservoir

    NASA Astrophysics Data System (ADS)

    Li, Li; Xiuting, Han; Lin, Meng

    Utilizing artificial fractured cores with low permeability, a physical simulation experiment on profile control for oil displacement was carried out. The result showed that 23.63% extra oil recovery was realized by functional polymer, and 29.05% extra oil recovery was realized by functional polymer with gas which is higher than water flooding alone. The experiment demonstrates that functional polymer is effective for enhance oil recovery for low permeability fractured reservoir significantly.

  15. A simulation research on evaluation of development in shale oil reservoirs by near-miscible CO2 flooding

    NASA Astrophysics Data System (ADS)

    Lai, Fengpeng; Li, Zhiping; Fu, Yingkun; Yang, Zhihao; Li, Hong

    2015-08-01

    Shale oil is a key resource that could mitigate the impending energy shortage in the future. Despite its abundance in China, studies on shale oil are still at the preliminary stage. Shale oil development through CO2 flooding has been successfully implemented in the United States. Therefore, the mechanics of CO2 flooding in shale oil reservoirs should be investigated. This study applies a simulation method to evaluate the development efficiency of CO2 flooding in shale oil reservoirs. Near-miscible CO2 flooding can effectively develop shale oil. After 20 years, recovery could improve by up to 9.56% as a result of depletion development under near-miscible CO2 flooding with 0.5% pore volume gas injection. Horizontal well injection is better than vertical well injection in terms of sweep efficiency and recovery. Cyclic gas injection is superior to continuous gas injection because the former reduces gas channelling. Thus, the use of horizontal wells with near-miscible cyclic gas injections has the potential to effectively develop shale oil reservoirs.

  16. Engineering protection of reservoirs of hydropower developments from flooding and subirrigation

    SciTech Connect

    Vasil'ev, Yu.S.; Khrisanov, N.I.

    1988-04-01

    Examples are given of current hydropower construction with the creation of systems of embanking lands for protecting them from flooding and subirrigation. The examples are drawn from hydropower developments in Canada, Ecuador, Hungary, Bulgaria, Romania, and the Soviet Union, and include tidal and nuclear plants as well. An analysis of the specific land-use intensity of different power stations showed that at present there is a tendency toward a reduction of the difference of this index for hydroelectric stations, on the one hand, and thermal power stations (nuclear power stations) on the other. For protection and conservation of lands and improvement of the ecological state of streams, reservoirs, and the lower pools of hydro developments, calculation methods (algorithms and programs) have been developed for optimizing the parameters of the embankment systems.

  17. [Influence of perennial flooding and drought on growth restoration of Acorus calamus in water-level-fluctuation zone of the Three Gorges Reservoir].

    PubMed

    Li, Qiang; Gao, Xiang; Ding, Wu-quan; Zhu, Qi-hong; Ou, Yuan; Liu, Yu

    2012-08-01

    Acorus calamus L. is a common kind of wetland plant species in the Three Gorges Reservoir. In this study, we investigated the influence of perennial flooding on growth restoration of A. calamus in the lightless conditions and the drought stress on this plant species' growth after flooding. Our research provided the scientific basis for the selection of candidate species for vegetations restoration in water-level-fluctuation zone of the Three Gorges Reservoir. A. calamus plants were exposed to waters in the lightless conditions in September 2009 and September 2010 respectively and taken away from the waters and grew in natural conditions in the following March, April and May (named as S1, S2, S3). All plants in the control, S1 and S2 groups were challenged with drought stress in May for 20 days. During the experiment, the plant number and leaf number were recorded regularly, as well as leaf length and leaf width. The results showed that flooding restrained the germination of the plants with much less plant in flooding groups than the control, and the plant germination rate had inverse relation to the flooding time. Flooding promoted formation and elongation of the leaves in S1 and S2 groups, which showed higher leaf growth parameters, such as leaf length, leaf number, total leaf length of one plant and total leaf length of all plants than the control. However, all of these growth parameters in S3 group had significantly lower values compared to the control. The survival rate of the plants after flooding decreased significantly with longer flooding time. Besides, the leaf length and leaf width in S1 and S2 groups increased significantly but with decreased leaf number. Additionally, all growth parameters (leaf length, leaf width, leaf number, total leaf number, total leaf length of one plant, total leaf length of all plants) in S3 group decreased remarkably. Furthermore, drought decreased the values of all growth parameters and the plant number in the control, S1 and

  18. Regional flood frequency analysis in Triveneto (Italy): climate and scale controls

    NASA Astrophysics Data System (ADS)

    Persiano, Simone; Castellarin, Attilio; Domeneghetti, Alessio; Brath, Armando

    2016-04-01

    The growing concern about the possible effects of climate change on flood frequency regime is leading Authorities to review previously proposed procedures for design-flood estimation, such as national regionalization approaches. Our study focuses on the Triveneto region, a broad geographical area in North-eastern Italy consisting of the administrative regions of Trentino-Alto Adige, Veneto and Friuli-Venezia Giulia. A reference procedure for design flood estimation in Triveneto is available from the Italian NCR research project "VA.PI.", which developed a regional model using annual maximum series (AMS) of peak discharges that were collected up to the 80s by the former Italian Hydrometeorological Service. We consider a very detailed AMS database that we recently compiled for ~80 catchments located in Triveneto. Our dataset includes the historical data mentioned above, together with more recent data obtained from Regional Services and annual maximum peak streamflows extracted from inflow series to artificial reservoirs and provided by dam managers. All ~80 study catchments are characterized in terms of several geomorphologic and climatic descriptors. The main objectives of our study are: (1) to check whether climatic and scale controls on flood frequency regime in Triveneto are similar to the controls that were recently found in Europe; (2) to verify the possible presence of trends as well as abrupt changes in the intensity and frequency of flood extremes by looking at changes in time of regional L-moments of annual maximum floods; (3) to assess the reliability and representativeness of the reference procedure for design flood estimation relative to flood data that were not included in the VA.PI. dataset (i.e. more recent data collected after the 80s and historical data provided by dam managers); (4) to develop an updated reference procedure for design flood estimation in Triveneto by using a focused-pooling approach (i.e. Region of Influence, RoI).

  19. Quality control of the RMS US flood model

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  20. Vector and reservoir control for preventing leishmaniasis

    PubMed Central

    González, Urbà; Pinart, Mariona; Sinclair, David; Firooz, Alireza; Enk, Claes; Vélez, Ivan D; Esterhuizen, Tonya M; Tristan, Mario; Alvar, Jorge

    2015-01-01

    Background Leishmaniasis is caused by the Leishmania parasite, and transmitted by infected phlebotomine sandflies. Of the two distinct clinical syndromes, cutaneous leishmaniasis (CL) affects the skin and mucous membranes, and visceral leishmaniasis (VL) affects internal organs. Approaches to prevent transmission include vector control by reducing human contact with infected sandflies, and reservoir control, by reducing the number of infected animals. Objectives To assess the effects of vector and reservoir control interventions for cutaneous and for visceral leishmaniasis. Search methods We searched the following databases to 13 January 2015: Cochrane Infectious Diseases Group Specialized Register, CENTRAL, MEDLINE, EMBASE, LILACS and WHOLIS, Web of Science, and RePORTER. We also searched trials registers for ongoing trials. Selection criteria Randomized controlled trials (RCTs) evaluating the effects of vector and reservoir control interventions in leishmaniasis-endemic regions. Data collection and analysis Two review authors independently searched for trials and extracted data from included RCTs. We resolved any disagreements by discussion with a third review author. We assessed the quality of the evidence using the GRADE approach. Main results We included 14 RCTs that evaluated a range of interventions across different settings. The study methods were generally poorly described, and consequently all included trials were judged to be at high or unclear risk of selection and reporting bias. Only seven trials reported clinical outcome data which limits our ability to make broad generalizations to different epidemiological settings and cultures. Cutaneous leishmaniasis One four-arm RCT from Afghanistan compared indoor residual spraying (IRS), insecticide-treated bednets (ITNs), and insecticide-treated bedsheets, with no intervention. Over 15 months follow-up, all three insecticide-based interventions had a lower incidence of CL than the control area (IRS: risk

  1. 33 CFR 209.220 - Flood control regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.220 Flood control regulations. (a) Local protection.... Regulations prescribed by the Secretary of the Army for the maintenance and operation of local...

  2. 33 CFR 209.220 - Flood control regulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.220 Flood control regulations. (a) Local protection.... Regulations prescribed by the Secretary of the Army for the maintenance and operation of local...

  3. 33 CFR 209.220 - Flood control regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.220 Flood control regulations. (a) Local protection.... Regulations prescribed by the Secretary of the Army for the maintenance and operation of local...

  4. 33 CFR 209.220 - Flood control regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.220 Flood control regulations. (a) Local protection.... Regulations prescribed by the Secretary of the Army for the maintenance and operation of local...

  5. 33 CFR 209.220 - Flood control regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.220 Flood control regulations. (a) Local protection.... Regulations prescribed by the Secretary of the Army for the maintenance and operation of local...

  6. The stability of chalk during flooding of carbonated sea water at reservoir in-situ conditions

    NASA Astrophysics Data System (ADS)

    Nermoen, Anders; Korsnes, Reidar I.; Madland, Merete V.

    2014-05-01

    Injection of CO2 into carbonate oil reservoirs has been proposed as a possible utilization of the captured CO2 due to its capability to enhance the oil recovery. For offshore reservoirs such as Ekofisk and Valhall it has been discussed to alternate the CO2 and sea water injection (WAG) to reduce costs and keep the beneficial effects of both sea water (SSW) and gas injection. Water and CO2 mix to form carbonic acids that enhance the solubility of carbonates, thus a serious concern has been raised upon the potential de-stabilization of the reservoirs during CO2 injection. In this study we focus on how carbonated sea water alters the mechanical integrity of carbonate rocks both to evaluate safety of carbon storage sites and in the planning of production strategies in producing oil fields since enhanced compaction may have both detrimental and beneficial effects. Here we will present results from long term experiments (approx. half year each) performed on Kansas outcrop chalk (38-41% porosity), which serves as model material to understand the physical and chemical interplaying processes taking place in chalk reservoirs. All tests are performed at uni-axial strain conditions, meaning that the confining radial stresses are automatically adjusted to ensure zero radial strain. The tests are performed at in-situ conditions and run through a series of stages that mimic the reservoir history at both Ekofisk and Valhall fields. We observe the strain response caused by the injected brine. The experimental stages are: (a) axial stress build-up by pore pressure depletion to stresses above yield with NaCl-brine which is inert to the chalk; (b) uni-axial creep at constant axial stresses with NaCl-brine; (c) sea water injection; and (d) injection of carbonated water (SSW+CO2) at various mixture concentrations. Two test series were performed in which the pore pressure was increased (re-pressurized) before stage (c) to explore the stress dependency of the fluid induced strain

  7. A reservoir operating method for riverine ecosystem protection, reservoir sedimentation control and water supply

    NASA Astrophysics Data System (ADS)

    Yin, Xin-An; Yang, Zhi-Feng; Petts, Geoffrey E.; Kondolf, G. Mathias

    2014-05-01

    Riverine ecosystem protection requires the maintenance of natural flow and sediment regimes downstream from dams. In reservoir management schedules this requirement should be integrated with sedimentation control and human water supply. However, traditional eco-friendly reservoir operating methods have usually only considered the natural flow regime. This paper seeks to develop a reservoir operating method that accounts for both the natural flow and sediment regimes as well as optimizing the water supply allocations. Herein, reservoir water level (RWL), sediment-occupied ratio of reservoir volume (SOR) and rate of change of SOR (RCSOR) are adopted as three triggers of a drawdown-flushing-based sediment management policy. Two different groups of reservoir operating rule curves (RORCs) are designed for sediment-flushing and non-sediment-flushing years, and the three triggers, RWL, SOR and RCSOR, are used to change the “static” RORCs to “dynamic” ones. The approach is applied to the Wangkuai Reservoir, China to test its effectiveness. This shows that the approach can improve the flexibility of reservoir operators to balance the reservoir management, water supply management and the flow and sediment needs of the downstream riverine ecosystem.

  8. Predictive Methods for Real-Time Control of Flood Operation of a Multireservoir System: Methodology and Comparative Study

    NASA Astrophysics Data System (ADS)

    Niewiadomska-Szynkiewicz, Ewa; Malinowski, Krzysztof; Karbowski, Andrzej

    1996-04-01

    Predictive methods for real-time flood operation of water systems consisting of reservoirs located in parallel on tributaries to the main river are presented and discussed. The aspect of conflicting individual goals of the local decision units and other objectives important from an overall point of view is taken into account. The particular attention is focused on hierarchical control structure which provides framework for organization of an on-line reservoir management problem. The important factor involved in flood control the uncertainty with respect to future inflows is taken into consideration. A case study of the upper Vistula river basin system in the southern part of Poland is presented. Simulation results based on 11 historical floods are briefly described and discussed.

  9. Operational Precipitation prediction in Support of Real-Time Flash Flood Prediction and Reservoir Management

    NASA Astrophysics Data System (ADS)

    Georgakakos, K. P.

    2006-05-01

    The presentation will outline the implementation and performance evaluation of a number of national and international projects pertaining to operational precipitation estimation and prediction in the context of hydrologic warning systems and reservoir management support. In all cases, uncertainty measures of the estimates and predictions are an integral part of the precipitation models. Outstanding research issues whose resolution is likely to lead to improvements in the operational environment are presented. The presentation draws from the experience of the Hydrologic Research Center (http://www.hrc-lab.org) prototype implementation projects at the Panama Canal, Central America, Northern California, and South-Central US. References: Carpenter, T.M, and K.P. Georgakakos, "Discretization Scale Dependencies of the Ensemble Flow Range versus Catchment Area Relationship in Distributed Hydrologic Modeling," Journal of Hydrology, 2006, in press. Carpenter, T.M., and K.P. Georgakakos, "Impacts of Parametric and Radar Rainfall Uncertainty on the Ensemble Streamflow Simulations of a Distributed Hydrologic Model," Journal of Hydrology, 298, 202-221, 2004. Georgakakos, K.P., Graham, N.E., Carpenter, T.M., Georgakakos, A.P., and H. Yao, "Integrating Climate- Hydrology Forecasts and Multi-Objective Reservoir Management in Northern California," EOS, 86(12), 122,127, 2005. Georgakakos, K.P., and J.A. Sperfslage, "Operational Rainfall and Flow Forecasting for the Panama Canal Watershed," in The Rio Chagres: A Multidisciplinary Profile of a Tropical Watershed, R.S. Harmon, ed., Kluwer Academic Publishers, The Netherlands, Chapter 16, 323-334, 2005. Georgakakos, K. P., "Analytical results for operational flash flood guidance," Journal of Hydrology, doi:10.1016/j.jhydrol.2005.05.009, 2005.

  10. High-Performance Integrated Control of water quality and quantity in urban water reservoirs

    NASA Astrophysics Data System (ADS)

    Galelli, S.; Castelletti, A.; Goedbloed, A.

    2015-11-01

    This paper contributes a novel High-Performance Integrated Control framework to support the real-time operation of urban water supply storages affected by water quality problems. We use a 3-D, high-fidelity simulation model to predict the main water quality dynamics and inform a real-time controller based on Model Predictive Control. The integration of the simulation model into the control scheme is performed by a model reduction process that identifies a low-order, dynamic emulator running 4 orders of magnitude faster. The model reduction, which relies on a semiautomatic procedural approach integrating time series clustering and variable selection algorithms, generates a compact and physically meaningful emulator that can be coupled with the controller. The framework is used to design the hourly operation of Marina Reservoir, a 3.2 Mm3 storm-water-fed reservoir located in the center of Singapore, operated for drinking water supply and flood control. Because of its recent formation from a former estuary, the reservoir suffers from high salinity levels, whose behavior is modeled with Delft3D-FLOW. Results show that our control framework reduces the minimum salinity levels by nearly 40% and cuts the average annual deficit of drinking water supply by about 2 times the active storage of the reservoir (about 4% of the total annual demand).

  11. Scale-up of miscible flood processes for heterogeneous reservoirs. Quarterly report, April 1, 1994--June 30, 1994

    SciTech Connect

    Orr, F.M. Jr.

    1994-07-01

    The current project is a systematic research effort to quantify relationships between process mechanisms that can lead to improved recovery from gas injection processes performed in heterogeneous Class 1 and Class 2 reservoirs. It will provide a rational basis for the design of displacement processes that take advantage of crossflow due to capillary, gravity and viscous forces to offset partially the adverse effects of heterogeneity. In effect, the high permeability zones are used to deliver fluid by crossflow to zones that would otherwise be flooded only very slowly. Thus, the research effort is divided into five areas: (a) Development of miscibility in multicomponent systems, (b) Design estimates for nearly miscible displacements, (c) Design of miscible floods for fractured reservoirs (d), Compositional flow visualization experiments, and (e) Simulation of near-miscible flow in heterogeneous systems. The status of the research effort in each area is reviewed briefly in the following section.

  12. Methane and nitrous oxide emissions in the littoral zone of a Chinese reservoir: environmental controls and implications for future designs

    NASA Astrophysics Data System (ADS)

    Yang, Meng; Lei, Guangchun; Grace, John; Geng, Xuemeng; Lu, Cai; Zhou, Yan; Zhu, Yi

    2015-04-01

    We report fluxes of CH4 and N2O using the static closed chamber and gas chromatography techniques from the littoral zone of Miyun Reservoir, a large reservoir providing water for Beijing. Seasonal and spatial variations of CH4 and N2O flux and environmental factors were monitored throughout the growing season including a flood event during summer rains. The littoral zone was divided into five areas based on water level. Sites were selected ranging from locations in open water to the dry area on higher ground, to provide five contrasting environments: deep water area, shallow water area, seasonal flooded area, 'seasonally flooded control' area and permanent non-flooded area. Our results showed that flooding increased CH4 emission sharply but did not influence N2O emission significantly. CH4 flux decreased along a transect from open water to dry land, from 3.1 mg m-2 h-1 at the deep water site to approximately 1.3 mg m-2 h-1 at the shallow water site, and less than 0.01 mg m-2 h-1 in the non-flooded area. The largest emission of all was from the seasonally flooded site after the flooding event (up to 21.1 mg m-2 h-1). N2O flux ranged from -2.97 μg m-2 h-1 to 180.06 μg m-2 h-1. Non flooded dry land emitted more N2O than flooded land, no matter whether it was permanently or seasonally flooded. No significant difference was observed between seasonally flooded sites (3.56±0.86 μg m-2 h-1) and their control sites (3.68±0.59 μg m-2 h-1). CH4 fluxes were correlated with air temperature, water depth, water dissolved oxygen, biomass and soil parameters including soil water content, bulk density, pH, total carbon, total nitrogen and NH4+. N2O fluxes were correlated with wind speed, air temperature, water dissolved oxygen, soil water content and soil NO3-. Thus the emissions of the two gases are controlled in different ways, and we discuss the possibilities of developing a spatio-temporal model to assist in the design and management of future reservoirs under a changing

  13. Spatial and Temporal Variation in Phytoplankton Structure in a Southeastern U.S. Reservoir Determined by HPLC and Light Microscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spatial and temporal variation in phytoplankton community characteristics within a large flood-control reservoir (Sardis Reservoir, MS, USA) were investigated in relation to variation in physicochemical properties, location within the reservoir, hydraulic residence time (HRT), nutrient concentration...

  14. Linkages between controlled floods, eddy sandbar dynamics, and riparian vegetation along the Colorado River in Marble Canyon, Arizona

    NASA Astrophysics Data System (ADS)

    Mueller, E. R.; Grams, P. E.; Hazel, J. E., Jr.; Schmeeckle, M. W.

    2015-12-01

    Controlled floods are released from Glen Canyon Dam to build and maintain eddy sandbars along the Colorado River in Grand Canyon National Park. Long-term monitoring shows that the topographic response to controlled floods varies considerably between eddies, likely reflecting different geometric configurations and flow hydraulics. Differences in eddy sandbar response also reflect the degree of vegetation establishment since the 1980s when reservoir spills more than double the magnitude of controlled floods cleared most sandbars of vegetation. Here we explore the geomorphology of sandbar responses in the context of controlled floods, debris fan-eddy geometry, and riparian vegetation establishment. In Marble Canyon, the proportion of eddy area stabilized by vegetation is negatively correlated with water surface slope and the rate of stage change with discharge. Less vegetated sites are more dynamic; they tend to build open sandbars during controlled floods and show greater topographic variability in the eddy compared to the main channel. In contrast, deposition of open sandbars is limited where vegetation establishment has decreased channel width, altering the pattern of eddy recirculation and sediment redistribution. In these locations, deposition during controlled floods is more akin to floodplain sedimentation, and the elevation of vegetated bar surfaces increases with successive floods. Changes in sand storage in the main channel are greater than storage change in the eddy at these lower gradient sites, and controlled floods tend to evacuate sand that has accumulated on the bed. The degree to which vegetation has stabilized sandbar surfaces may thus provide a proxy for different hydraulic conditions and a better canyon-wide assessment of controlled flood response. Our results apply primarily to large eddies in Marble Canyon, and ongoing flow modeling and vegetation composition mapping will allow further assessment of eddy sandbar-riparian vegetation interactions

  15. Floods

    MedlinePlus

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

  16. Effects on water quality due to flood-water detention by Barker and Addicks Reservoirs, Houston, Texas

    USGS Publications Warehouse

    Liscum, Fred; Paul, E.M.; Goss, R.L.

    1987-01-01

    The Barker and Addicks Reservoirs, located about 16 mi west of Houston, Texas, provide flood detention storage for storm runoff. Of interest are the water quality characteristics in the study area and changes in water quality during detention. Study area sampling sites were selected upstream along Buffalo Bayou for Barker Reservoir and on Bear Creek and Langham Creek for Addicks Reservoir, within the reservoirs, near the reservoir outflows, and below the confluence of each reservoir outflow at the streamflow station Buffalo Bayou near Addicks. Flow data were available at all sites except in the reservoirs. Analyses of samples collected during both low flow and storm runoff show that in general, the water of the study areas was low in mineralization, but the aesthetics of the water was a problem. The inorganic constituents, trace metals, and pesticides rarely exceeded maximum contaminant levels recommended by the EPA for public supply using 1976 and 1977 criteria for primary and secondary standards. All species of nutrients, except ammonia nitrogen and phosphorus, almost always were below the recommended maximum contaminant levels. Large values of suspended solids, turbidity, and color were common. Possible bacterial problems are indicated because coliform bacteria densities exceeded recommended levels in about 25% of the samples. The effects of the reservoirs on the water quality characteristics of storm runoff were analyzed using three approaches: (1) a comparison of the discharge weighted average values of nine selected constituents at each streamflow-gaging station during four storms (biochemical oxygen demand, suspended solids, turbidity, color, total nitrogen, total organic carbon, dissolved solids and total phosphorus); (2) an analysis of the means of the discharge weighted average values computed for the four hydrologic events using the Student t-test, indicating that reservoir detention significantly reduced suspended solids; and (3) a comparison at each

  17. Hospital infection prevention and control issues relevant to extensive floods.

    PubMed

    Apisarnthanarak, Anucha; Mundy, Linda M; Khawcharoenporn, Thana; Glen Mayhall, C

    2013-02-01

    The devastating clinical and economic implications of floods exemplify the need for effective global infection prevention and control (IPC) strategies for natural disasters. Reopening of hospitals after excessive flooding requires a balance between meeting the medical needs of the surrounding communities and restoration of a safe hospital environment. Postflood hospital preparedness plans are a key issue for infection control epidemiologists, healthcare providers, patients, and hospital administrators. We provide recent IPC experiences related to reopening of a hospital after extensive black-water floods necessitated hospital closures in Thailand and the United States. These experiences provide a foundation for the future design, execution, and analysis of black-water flood preparedness plans by IPC stakeholders. PMID:23295568

  18. Controls on reservoir development in Devonian Chert: Permian Basin, Texas

    SciTech Connect

    Ruppel, S.C.; Hovorka, S.D.

    1995-12-01

    Chert reservoirs of the Lower Devonian Thirtyone Formation contain a significant portion of the hydrocarbon resource in the Permian basin. More than 700 million bbl of oil have been produced from these rocks, and an equivalent amount of mobile oil remains. Effective exploitation of this sizable remaining resource, however, demands a comprehensive appreciation of the complex factors that have contributed to reservoir development. Analysis of Thirtyone Formation chert deposits in Three Bar field and elsewhere in the Permian basin indicates that reservoirs display substantial heterogeneity resulting from depositional, diagenetic, and structural processes. Large-scale reservoir geometries and finer scale, intra-reservoir heterogeneity are primarily attributable to original depositional processes. Despite facies variations, porosity development in these cherts is principally a result of variations in rates and products of early silica diagenesis. Because this diagenesis was in part a function of depositional facies architecture, porosity development follows original depositional patterns. In reservoirs such as Three Bar field, where the Thirtyone Formation has been unroofed by Pennsylvanian deformation, meteoric diagenesis has created additional heterogeneity by causing dissolution of chert and carbonate, especially in areas of higher density fracturing and faulting and along truncated reservoir margins. Structural deformation also has exerted direct controls on heterogeneity that are particularly noteworthy in reservoirs under waterflood. High-density fracture zones create preferred flow paths that result in nonuniform sweep through the reservoir. Faulting locally creates compartments by offsetting reservoir flow units. As such, the processes and models defined here improve understanding of the causes of heterogeneity in all Thirtyone chert reservoirs in the Permian basin and aid recovery of the sizable hydrocarbon resource remaining in these rocks.

  19. Simulated monthly hydrologic data and estimated flood characteristics for Cherry Creek at a proposed reservoir site near Terry, Montana

    USGS Publications Warehouse

    Parrett, Charles; Johnson, D.R.

    1995-01-01

    A monthly hydrologic budget for water years 1937- 92 was developed for the proposed Cherry Creek Reservoir (maximum volume about 14,100 acre-feet). Monthly suspended-sediment loads and dissolved- solids concentrations in the reservoir and flood hydrographs and volumes having recurrence intervals of 25-, 50-, and 100-years were estimated. Monthly streamflow and precipitation were estimated using a mixed-station, record-extension procedure. Monthly suspended-sediment and dissolved-solids concentrations in the reservoir were estimated from regression relations between logarithms of concen- tration and streamflow. The simulation showed that flows that Cherry Creek generally were adequate to maintain the reservoir elevation above the minimum operating level for a seepage loss of 0 cubic ft per square. With a seepage loss rate of 3 cubic ft per square, diversions from the Yellowstone River were required for about on third of the months. Cumulative sediment deposition during the 56-year simulation period was about 138 acre-ft from Cherry Creek alone and was about 149 acre-ft when additional water was imported from the Yellowstone River. The concentration of dissolved solids in the reservoir reached a maximum value of about 2,540 mg/L for a seepage loss of 0 cubic ft per square. For a seepage loss of 3 cubic ft per square, water was imported from the Yellowstone River and the maximum concentration of dissolved solids was about 1,200 mg/L. Volumes for flood discharges were estimated from synthetic 24-hour duration storms that were used in a rainfall-runoff model (HEC-1).

  20. Geology of the Roswell artesian basin, New Mexico, and its relation to the Hondo Reservoir and Effect on artesian aquifer storage of flood water in Hondo Reservoir

    USGS Publications Warehouse

    Bean, Robert T.; Theis, Charles V.

    1949-01-01

    In the Roswell Basin in southeastern New Mexico artesian water is produced from cavernous zones in the carbonate rocks of the San Andres formation and the lower part of the Chalk Bluff formation, both of Permian age. The Hondo Reservoir, 9 miles west-southwest of Roswell, was completed by the U. S. Bureau of Reclamation in 1907, to store waters of the Rio Hondo for irrigation. The project was not successful, as the impounded water escaped rapidly through holes in the gypsum and limestone of the San Andres formation constituting its floor. Of 27,000 acre~feet that entered the reservoir between 1908 and 1913, only 1,100 acre-feet was drawn Ollt for use, the remainder escaping through the floor of the reservoir. Since 1939, plans have been drawn up by the State Engineer and by Federal agencies to utilize the reservoir to protect Roswell from floods. It has also been suggested that water from the Pecos River might be diverted into underground storage through the reservoir. Sinkholes in the Roswell Basin are largely clustered in areas where gypsum occurs in the bedrock. Collapse of strata is due to solution of underlying rock commonly containing gypsum. Domes occur in gypsiferous strata near Salt Creek. The Bottomless Lakes, sinkhole lakes in the escarpment on the east side of the Pecos, are believed to have developed in north-south hinge-line fractures opened when the westernmost beds in the escarpment collapsed. Collapse was due to solution and removal of gypsiferous rock by artesian water which now fills the lakes.

  1. 33 CFR 239.7 - Separation of flood control works from urban drainage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Separation of flood control works... COVERED FLOOD CONTROL CHANNELS § 239.7 Separation of flood control works from urban drainage. Covered channels are likely to be considered in boundary areas demarking urban drainage and flood...

  2. Flooding and Flood Management

    USGS Publications Warehouse

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

    2011-01-01

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

  3. 33 CFR 203.50 - Nonstructural alternatives to rehabilitation of flood control works.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... adherence to, Executive Order 11988, Floodplain Management, 3 CFR 117 (1977 Compilation), or as it may be... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm... rehabilitation, repair, or restoration of flood control works damaged by floods or coastal storms. (b) Policy....

  4. 33 CFR 203.42 - Inspection of non-Federal flood control works.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Inspection of non-Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.42 Inspection of non-Federal flood control works. (a)...

  5. 33 CFR 203.42 - Inspection of non-Federal flood control works.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Inspection of non-Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.42 Inspection of non-Federal flood control works. (a)...

  6. 33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... flood control works. 203.44 Section 203.44 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.44 Rehabilitation of non-Federal flood...

  7. 33 CFR 203.47 - Modifications to non-Federal flood control works.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... flood control works. 203.47 Section 203.47 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.47 Modifications to non-Federal flood...

  8. 33 CFR 203.47 - Modifications to non-Federal flood control works.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... flood control works. 203.47 Section 203.47 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.47 Modifications to non-Federal flood...

  9. 33 CFR 203.42 - Inspection of non-Federal flood control works.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Inspection of non-Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.42 Inspection of non-Federal flood control works. (a)...

  10. 33 CFR 203.45 - Rehabilitation of Federal flood control works.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Rehabilitation of Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.45 Rehabilitation of Federal flood control works. Rehabilitation...

  11. 33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... flood control works. 203.44 Section 203.44 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.44 Rehabilitation of non-Federal flood...

  12. 33 CFR 203.45 - Rehabilitation of Federal flood control works.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Rehabilitation of Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.45 Rehabilitation of Federal flood control works. Rehabilitation...

  13. 33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... flood control works. 203.44 Section 203.44 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.44 Rehabilitation of non-Federal flood...

  14. 33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... flood control works. 203.44 Section 203.44 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.44 Rehabilitation of non-Federal flood...

  15. 33 CFR 203.42 - Inspection of non-Federal flood control works.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Inspection of non-Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.42 Inspection of non-Federal flood control works. (a)...

  16. 33 CFR 203.47 - Modifications to non-Federal flood control works.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... flood control works. 203.47 Section 203.47 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.47 Modifications to non-Federal flood...

  17. 33 CFR 203.45 - Rehabilitation of Federal flood control works.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Rehabilitation of Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.45 Rehabilitation of Federal flood control works. Rehabilitation...

  18. 33 CFR 203.47 - Modifications to non-Federal flood control works.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... flood control works. 203.47 Section 203.47 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.47 Modifications to non-Federal flood...

  19. 33 CFR 203.45 - Rehabilitation of Federal flood control works.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Rehabilitation of Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.45 Rehabilitation of Federal flood control works. Rehabilitation...

  20. 33 CFR 203.43 - Inspection of Federal flood control works.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... accordance with 33 CFR 208.10 and Engineer Regulation (ER) 1130-2-530, Flood Control Operations and... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Inspection of Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The...

  1. 33 CFR 203.42 - Inspection of non-Federal flood control works.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Inspection of non-Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.42 Inspection of non-Federal flood control works. (a)...

  2. 33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... flood control works. 203.44 Section 203.44 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.44 Rehabilitation of non-Federal flood...

  3. 33 CFR 203.47 - Modifications to non-Federal flood control works.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... flood control works. 203.47 Section 203.47 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.47 Modifications to non-Federal flood...

  4. 33 CFR 203.45 - Rehabilitation of Federal flood control works.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Rehabilitation of Federal flood... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.45 Rehabilitation of Federal flood control works. Rehabilitation...

  5. Shoreline to Height (S2H): an algorithm to monitor reservoirs' water height from satellite images. A flood risk management application

    NASA Astrophysics Data System (ADS)

    Cenci, Luca; Boni, Giorgio; Pulvirenti, Luca; Gabellani, Simone; Gardella, Fabio; Squicciarino, Giuseppe; Pierdicca, Nazzareno; Benedetto, Catia

    2016-04-01

    In a reservoir, water level monitoring is important for emergency management purposes. This information can be used to estimate the degree of filling of the water body, thus helping decision makers in flood control operations. Furthermore, if assimilated in hydrological models and coupled with rainfall forecasts, this information can be used for flood forecast and early warning. In many cases, water level is not known (e.g. data-scarce environments), or not shared by operators. Remote sensing may allow overcoming these limitations, enabling its estimation. The objective of this work is to present the Shoreline to Height (S2H) algorithm, developed to retrieve the height of the water stored in reservoirs from satellite images. To this aim, some auxiliary data are needed: a DEM and the maximum/minimum height that can be reached by the water. In data-scarce environments, these information can be easily obtained on the Internet (e.g. free, worldwide DEM and design data for artificial reservoirs). S2H was tested with different satellite data, both optical and SAR (Landsat and Cosmo SkyMed®-CSK®) in order to assess the impact of different sensors on the final estimates. The study area was the Place-Moulin Lake (Valle d'Aosta-VdA, Italy), where it is present a monitoring network that can provide reliable ground-truths for validating the algorithm and assessing its accuracy. When the algorithm was developed, it was assumed to be in absence of any "official"-auxiliary data. Therefore, two DEMs (SRTM 1 arc-second and ASTER GDEM) were used to evaluate their performances. The maximum/minimum water height values were found on the website of VdA Region. The S2H is based on three steps: i) satellite data preprocessing (Landsat: atmospheric correction; CSK®: geocoding and speckle filtering); ii) water mask generation (using a thresholding and region growing algorithm) and shoreline extraction; iii) retrieval of the shoreline height according to the reference DEMs (adopting a

  6. Spatial variability of greenhouse gases emissions (CO2, CH4, N2O) in a tropical hydroelectric reservoir flooding primary forest (Petit Saut Reservoir, French Guiana)

    NASA Astrophysics Data System (ADS)

    Cailleaud, Emilie; Guérin, Frédéric; Bouillon, Steven; Sarrazin, Max; Serça, Dominique

    2014-05-01

    At the Petit Saut Reservoir (PSR, French Guiana, South America), vertical profiles were performed at 5 stations in the open waters (OW) and 6 stations in two shallow flooded forest (FF) areas between April 2012 and September 2013. Measurements included physico-chemical parameters, ammonium, nitrate and dissolved greenhouse gas (CO2, CH4, N2O) concentrations, dissolved and particulate organic carbon (DOC, POC) and nitrogen (PN), δ13C-POC and δ15N-PN . The diffusive fluxes were calculated from surface concentrations. The aim of this study was to estimate the spatial variations of greenhouse gas emissions at a dentrical hydroelectric reservoir located in the tropics and flooding primary forest. Twenty years after impoundment, the water column of the PSR is permanently and tightly stratified thermally in the FF whereas in the OW, the thermal gradients are not as stable. The different hydrodynamical behaviours between the two different zones have significant consequences on the biogeochemistry: oxygen barely diffuses down to the hypolimnion in the FF whereas destratification occurs sporadically during the rainy season in the OW. Although we found the same range of POC in the FF and the OW (2.5-29 μmol L-1) and 20% more DOC at the bottom of OW than in the FF (229-878 μmol L-1), CO2 and CH4 concentrations were always significantly higher in the FF (CO2: 11-1412 μmol L-1, CH4: 0.001-1015 μmol L-1) than in the OW. On average, the CO2 concentrations were 30-40% higher in the FF than in the OW and the CH4 concentrations were three times higher in the FF than in the OW. The δ13C-POC and C:N values did not suggest substantial differences in the sources of OM between the FF and OW. At all stations, POC at the bottom has an isotopic signature slightly lighter than the terrestrial OM in the surrounding forest whereas the isotopic signature of surface POM would result from phytoplankton and methanotrophs. The vertical profiles of nitrogen compounds reveal that the main

  7. 43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Lahontan Reservoir. 418.24 Section 418.24 Public Lands: Interior Regulations Relating to Public Lands... Reservoir. (a) Even though flood control is not a specifically authorized purpose of the Project, at the..., precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson...

  8. 43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Lahontan Reservoir. 418.24 Section 418.24 Public Lands: Interior Regulations Relating to Public Lands... Reservoir. (a) Even though flood control is not a specifically authorized purpose of the Project, at the..., precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson...

  9. 43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Lahontan Reservoir. 418.24 Section 418.24 Public Lands: Interior Regulations Relating to Public Lands... Reservoir. (a) Even though flood control is not a specifically authorized purpose of the Project, at the..., precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson...

  10. 43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Lahontan Reservoir. 418.24 Section 418.24 Public Lands: Interior Regulations Relating to Public Lands... Reservoir. (a) Even though flood control is not a specifically authorized purpose of the Project, at the..., precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson...

  11. 43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Lahontan Reservoir. 418.24 Section 418.24 Public Lands: Interior Regulations Relating to Public Lands... Reservoir. (a) Even though flood control is not a specifically authorized purpose of the Project, at the..., precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson...

  12. On the Integration of Risk Aversion and Average-Performance Optimization in Reservoir Control

    NASA Astrophysics Data System (ADS)

    Nardini, Andrea; Piccardi, Carlo; Soncini-Sessa, Rodolfo

    1992-02-01

    The real-time operation of a reservoir is a matter of trade-off between the two criteria of risk aversion (to avoid dramatic failures) and average-performance optimization (to yield the best long-term average performance). A methodology taking into account both criteria is presented m this paper to derive "off-line" infinite-horizon control policies for a single multipurpose reservoir, where the management goals are water supply and flood control. According to this methodology, the reservoir control policy is derived in two steps: First, a (min-max) risk aversion problem is formulated, whose solution is not unique, but rather a whole set of policies, all equivalent from the point of view of the risk-aversion objectives. Second, a stochastic average-performance optimization problem is solved, to select from the set previously obtained the best policy from the point of view of the average-performance objectives. The methodology has several interesting features: the rnin-max (or "guaranteed performance") approach, which is particularly suited whenever "weak" users are affected by the consequences of the decision-making process; the flexible definition of a "risk aversion degree," by the selection of those inflow sequences which are particularly feared; and the two-objective analysis which provides the manager with a whole set of alternatives among which he (she) will select the one that yields the desired trade-off between the management goals.

  13. Analysis of floods, including the tropical storm Irene inundation, of the Ottauquechee River in Woodstock, Bridgewater, and Killington and of Reservoir Brook in Bridgewater and Plymouth, Vermont

    USGS Publications Warehouse

    Flynn, Robert H.

    2014-01-01

    In addition to the two digital flood inundation maps, flood profiles were created that depict the study reach flood elevation of tropical storm Irene of August 2011 and the 10-, 2-, 1-, and 0.2-percent AEP floods, also known as the 10-, 50-, 100-, and 500-year floods, respectively. The 10-, 2-, 1-, and 0.2-percent AEP flood discharges were determined using annual peak flow data from the USGS Ottauquechee River near West Bridgewater, Vt. streamgage (station 01150900). Flood profiles were computed for the Ottauquechee River and Reservoir Brook by means of a one-dimensional step-backwater model. The model was calibrated using documented high-water marks of the peak of the tropical storm Irene flood of August 2011 as well as stage discharge data as determined for USGS Ottauquechee River near West Bridgewater, Vt. streamgage (station 01150900). The simulated water-surface profiles were combined with a digital elevation model within a geographic information system to delineate the areas flooded during tropical storm Irene and for the 1-percent AEP water-surface profile. The digital elevation model data were derived from light detection and ranging (lidar) data obtained for a 3,281-foot (1,000-meter) corridor along the Ottauquechee River study reach and were augmented with 33-foot (10- meter) contour interval data in the modeled flood-inundation areas outside the lidar corridor. The 33-foot (10-meter) contour interval USGS 15-minute quadrangle topographic digital raster graphics map used to augment lidar data was produced at a scale of 1:24,000. The digital flood inundation maps and flood profiles along with information regarding current stage from USGS streamgages on the Internet provide emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures, as well as for post-flood recovery efforts.

  14. Scale-up of miscible flood processes for heterogeneous reservoirs. Quarterly report, 1 January--31 March 1994

    SciTech Connect

    Orr, F.M. Jr.

    1994-04-01

    The current project is a systematic research effort aimed at quantifying relationships between process mechanisms that can lead to improved recovery from gas injection processes performed in heterogeneous Class 1 and Class 2 reservoirs. It will provide a rational basis for the design of displacement processes that take advantage of crossflow due to capillary, gravity and viscous forces to offset partially the adverse effects of heterogeneity. In effect, the high permeability zones are used to deliver fluid by crossflow to zones that would otherwise be flooded only very slowly. Thus, the research effort is divided into five areas: Development of miscibility in multicomponent systems; design estimates for nearly miscible displacements; design of miscible floods for fractured reservoirs; compositional flow visualization experiments; simulation of near-miscible flow in heterogeneous systems. The status of the research effort in each area is reviewed briefly in the following section. From this work, we can make the following conclusions: (1) We demonstrated theoretically and experimentally that a linear combination of gravity and viscous forces can be used to correlate residual nonwetting phase saturations for both gravity-favorable and gravity-unfavorable displacements. (2) When gravity forces are comparable to or larger than the viscous forces) gravity unfavorable displacements have significantly higher residual nonwetting phase saturation than gravity-favorable displacements. (3) Because soils have much higher permeabilities than oil reservoirs, gravity effects on residual nonwetting phase saturations are much more significant in spilled-oil clean-up than in oil recovery processes. (4) The effective correlation length for a percolation process can be related to a linear combination of the gravity and viscous forces.

  15. Improved Miscible Nitrogen Flood Performance Utilizing Advanced Reservoir Characterization and Horizontal Laterals in a Class I Reservoir - East Binger (Marchand) Unit

    SciTech Connect

    Joe Sinner

    2004-06-30

    The DOE-sponsored project at the East Binger Unit is an investigation into the benefits of reservoir characterization and horizontal wells in this particular setting of geologic and recovery method. The geologic setting is a tight (average porosity of 7% and average permeability of less than 1 millidarcy) Pennsylvanian-age sandstone at about 10,000 feet, and the recovery method is a miscible nitrogen flood. The projected oil recovery of the East Binger Unit, prior to the initiation of this project, was about 25%. Gravity segregation of nitrogen and crude oil was believed to be the principal cause of the poor sweep efficiency, and it was envisioned that with horizontal producing wells in the lower portion of the reservoir and horizontal injection wells near the top, the process could be converted from a lateral displacement process to a vertical displacement/gravity assisted process. Through the characterization and field development work completed in Budget Periods 1 and 2, Binger Operations, LLC (BOL) has developed a different interpretation of the sweep problem as well as a different approach to improving recovery. The sweep problem is now believed to be one of an areal nature, due to a combination of natural and hydraulic fracturing. Vertical wells have provided a much better economic return than have the horizontal wells. The natural and hydraulic fracturing manifests itself as a direction of higher permeability, and the flood is being converted to a line drive flood aligned with this orientation. Consistent with this concept, horizontal wells have been drilled along the line of the fracture orientation, such that hydraulic fracturing leads to 'longitudinal' fractures, in line with the wellbore. As such, the hydraulically fractured horizontal wells are not significantly different than hydraulically fractured vertical wells - save for the potential for a much longer fracture face. This Topical Report contains data from new wells, plus new and updated production

  16. Changes in bottom-surface elevations in three reservoirs on the lower Susquehanna River, Pennsylvania and Maryland, following the January 1996 flood; implications for nutrient and sediment loads to Chesapeake Bay

    USGS Publications Warehouse

    Langland, Michael J.; Hainly, Robert A.

    1997-01-01

    ,000 and 5,000 mg/kg. About 96 percent of the concentrations of total nitrogen consisted of organic nitrogen. Concentrations of total phosphorus in bottom sediments ranged from 286 to 1,390 mg/kg. About 84 percent of the concentrations of total phosphorus were comprised of inorganic phosphorus. The ratio of concentrations of plant-available phosphorus to concentrations of total phosphorus ranged from 0.6 to 3.5 percent; ratios generally decreased in a downstream direction. About 29,000 acre-feet, or 42,000,000 tons, of sediment can be deposited before Conowingo Reservoir reaches sediment-storage capacity. Assuming the average annual sediment-deposition rate remains unchanged and no scour occurs due to floods, the reservoir system could reach sediment-storage capacity in about 17 years. The reservoir system currently is trapping about 2 percent of the nitrogen, 45 percent of the phosphorus, and 70 percent of the suspended sediment transported by the river to the upper Chesapeake Bay. Once the reservoir reaches sediment-storage capacity, an estimated 250-percent increase in the current annual loads of suspended sediment, a 2-percent increase in the current annual loads of total nitrogen, and a 70-percent increase in the current annual loads of total phosphorus from the Susquehanna River to Chesapeake Bay can be expected. If the goal of a 40-percent reduction in controllable phosphorus load from the Susquehanna River Basin is met before the reservoirs reach sediment-storage capacity, the 40-percent reduction goal will probably be exceeded when the reservoir system reaches sediment-storage capacity.

  17. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II

    SciTech Connect

    Wier, Don R. Chimanhusky, John S.; Czirr, Kirk L.; Hallenbeck, Larry; Gerard, Matthew G.; Dollens, Kim B.; Owen, Rex; Gaddis, Maurice; Moshell, M.K.

    2002-11-18

    The purpose of this project was to economically design an optimum carbon dioxide (CO2) flood for a mature waterflood nearing its economic abandonment. The original project utilized advanced reservoir characterization and CO2 horizontal injection wells as the primary methods to redevelop the South Cowden Unit (SCU). The development plans; project implementation and reservoir management techniques were to be transferred to the public domain to assist in preventing premature abandonment of similar fields.

  18. New petrophysical magnetic methods MACC and MAFM in permeability characterisation of petroleum reservoir rock cleaning, flooding modelling and determination of fines migration in formation damage

    NASA Astrophysics Data System (ADS)

    Ivakhnenko, O. P.

    2012-04-01

    Potential applications of magnetic techniques and methods in petroleum engineering and petrophysics (Ivakhnenko, 1999, 2006; Ivakhnenko & Potter, 2004) reveal their vast advantages for the petroleum reservoir characterisation and formation evaluation. In this work author proposes for the first time developed systematic methods of the Magnetic Analysis of Core Cleaning (MACC) and Magnetic Analysis of Fines Migration (MAFM) for characterisation of reservoir core cleaning and modelling estimations of fines migration for the petroleum reservoir formations. Using example of the one oil field we demonstrate results in application of these methods on the reservoir samples. Petroleum reservoir cores samples have been collected within reservoir using routine technique of reservoir sampling and preservation for PVT analysis. Immediately before the MACC and MAFM studies samples have been exposed to atmospheric air for a few days. The selected samples have been in detailed way characterised after fluid cleaning and core flooding by their mineralogical compositions and petrophysical parameters. Mineralogical composition has been estimated utilizing XRD techniques. The petrophysical parameters, such as permeability and porosity have been measured on the basis of total core analysis. The results demonstrate effectiveness and importance of the MACC and MAFM methods for the routine core analysis (RCAL) and the special core analysis (SCAL) in the reservoir characterisation, core flooding and formation damage analysis.

  19. 33 CFR 203.43 - Inspection of Federal flood control works.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... accordance with 33 CFR 208.10 and Engineer Regulation (ER) 1130-2-530, Flood Control Operations and Maintenance Policies. These periodic inspections of Federal flood control works are also, for...

  20. 33 CFR 203.43 - Inspection of Federal flood control works.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... accordance with 33 CFR 208.10 and Engineer Regulation (ER) 1130-2-530, Flood Control Operations and Maintenance Policies. These periodic inspections of Federal flood control works are also, for...

  1. 33 CFR 203.43 - Inspection of Federal flood control works.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... accordance with 33 CFR 208.10 and Engineer Regulation (ER) 1130-2-530, Flood Control Operations and Maintenance Policies. These periodic inspections of Federal flood control works are also, for...

  2. Post Waterflood CO2 Miscible Flood in Light Oil, Fluvial-Dominated Deltaic Reservoir, Class I

    SciTech Connect

    Bou-Mikael, Sami

    2002-02-05

    This report demonstrates the effectiveness of the CO2 miscible process in Fluvial Dominated Deltaic reservoirs. It also evaluated the use of horizontal CO2 injection wells to improve the overall sweep efficiency. A database of FDD reservoirs for the gulf coast region was developed by LSU, using a screening model developed by Texaco Research Center in Houston. The results of the information gained in this project is disseminated throughout the oil industry via a series of SPE papers and industry open forums.

  3. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect

    Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Ananad; Wavrik, Kathryn

    2001-10-29

    This report describes work performed during the third and final year of the project, Using Chemicals to Optimize Conformance Control in Fractured Reservoirs. This research project had three objectives. The first objective was to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective was to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective was to develop procedures to optimize blocking agent placement in naturally fractured reservoirs.

  4. A centralized real-time controller for the reservoir's management on the Seine River using ensemble weather forecasting

    NASA Astrophysics Data System (ADS)

    Ficchi, Andrea; Raso, Luciano; Jay-Allemand, Maxime; Dorchies, David; Malaterre, Pierre-Olivier; Pianosi, Francesca; Van Overloop, Peter-Jules

    2013-04-01

    The reservoirs on the Seine River, upstream of Paris, are regulated with the objective of reducing floods and supporting low flows. The current management of these reservoirs is empirical, reactive, and decentralized, mainly based on filling curves, constructed from an analysis of historical floods and low flows. When inflows are significantly different from their seasonal average, this management strategy proves inefficient. Climate change is also a challenge, for the possible modification of future hydrologic conditions. To improve such management strategy, in this study we investigate the use of Tree-Based Model Predictive Control (TB-MPC), a proactive and centralized method that uses all the information available in real-time, including ensemble weather forecasting. In TB-MPC, a tree is generated from an ensemble of weather forecast. The tree structure summarizes the information contained in the ensemble, specifying the time, along the optimization horizon, when forecast trajectories diverge and thus uncertainty is expected to be resolved. This information is then used in the model predictive control framework. The TB-MPC controller is implemented in combination with the integrated model of the water system, including a semi-distributed hydrologic model of the watershed, a simplified hydraulic model of the river network, and the four reservoir models. Optimization takes into account the cost associated to floods and low-flows, and a penalty cost based on the final reservoir storages. The performances of the TB-MPC controller will be simulated and compared with those of deterministic MPC and with the actual management performances. This work is part of the Climaware European project (2010-2013) set up to develop and to assess measures for sustainable water resources management regarding adaptation to climate change.

  5. 76 FR 6809 - Rehabilitation Assistance for Levees and other Flood Control Works, DAP 9524.3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-08

    ... SECURITY Federal Emergency Management Agency Rehabilitation Assistance for Levees and other Flood Control... Rehabilitation Assistance for Levees and other Flood Control Works. DATES: Comments must be received by March 10... certain levees and other flood control works under the provisions of the Robert T. Stafford...

  6. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  7. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  8. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  9. 33 CFR 263.24 - Authority for snagging and clearing for flood control (Section 208).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... clearing for flood control (Section 208). 263.24 Section 263.24 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.24 Authority for snagging and clearing for flood control (Section 208). (a)...

  10. 33 CFR 263.24 - Authority for snagging and clearing for flood control (Section 208).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... clearing for flood control (Section 208). 263.24 Section 263.24 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.24 Authority for snagging and clearing for flood control (Section 208). (a)...

  11. 33 CFR 263.24 - Authority for snagging and clearing for flood control (Section 208).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... clearing for flood control (Section 208). 263.24 Section 263.24 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.24 Authority for snagging and clearing for flood control (Section 208). (a)...

  12. 33 CFR 263.24 - Authority for snagging and clearing for flood control (Section 208).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... clearing for flood control (Section 208). 263.24 Section 263.24 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.24 Authority for snagging and clearing for flood control (Section 208). (a)...

  13. 33 CFR 263.24 - Authority for snagging and clearing for flood control (Section 208).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... clearing for flood control (Section 208). 263.24 Section 263.24 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.24 Authority for snagging and clearing for flood control (Section 208). (a)...

  14. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  15. Was all that Los Angeles River flood control concrete necessary?

    NASA Astrophysics Data System (ADS)

    Patzert, W. C.; Regalado, S. S.; LaDochy, S.; Ramirez, P. C.; Willis, J. K.

    2014-12-01

    In 1938, heavy rains over the Los Angeles Basin resulted in widespread and costly flooding of the Los Angeles River floodplain. In response to the resultant damage, 51 miles of the River was concreted from the San Fernando Valley to the Pacific Ocean. Today proposals to modify the river to capture more water and to restore it to a more natural state have been approved. Through comparison of rainfall data, we test whether channelization can adequately handle the extreme flooding events occurring since 1938. Between February 27th to March 3rd 1938, two major storms resulted in 14.1 inches of rain in Pasadena, CA leading to the flooding of the Los Angeles River, 115 fatalities, the destruction of 5,601 buildings, and to $627 million (2011 dollars) in damages. Downtown Los Angeles averages 15 inches of precipitation a year, while the San Gabriel Mountains, where most of the Los Angeles River watershed rainfall is collected, typically receive more than 40 inches of rain annually. Eight record storms, each with rainfall totals over 11 inches, since the 1938 flood could have created devastating deluges were it not for channelization. Presently, at full stage the channelized Los Angeles River can accommodate a discharge of 129,000 cfs. During the 1938 flood event the discharge peaked at 68,000 cfs above Arroyo Seco and 79,000 cfs below Firestone Blvd. A similar storm event today would have led to increased discharge due to urbanization. Since 1938, the greatest discharge recorded at the same stations was 52,200 and 74,400 cfs during the February 16th 1980 storm. Although damage was substantial during this storm, river channelization prevented fatalities and much damage. To date, the channelization of the Los Angeles River has been successful in flood control. However, our research shows that southern California precipitation is becoming more intense which may result in increased flooding. Any future modifications to the river must be prepared to handle the extreme flooding

  16. Structural master plan of flood mitigation measures

    NASA Astrophysics Data System (ADS)

    Heidari, A.

    2009-01-01

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

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

    USGS Publications Warehouse

    Sloto, R.A.

    1988-01-01

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

  18. Post Waterflood CO2 Miscible Flood in Light Oil, Fluvial-Dominated Deltaic Reservoir (Pre-Work and Project Proposal - Appendix)

    SciTech Connect

    Bou-Mikael, Sami

    2002-02-05

    The main objective of the Port Neches Project was to determine the feasibility and producibility of CO2 miscible flooding techniques enhanced with horizontal drilling applied to a Fluvial Dominated Deltaic reservoir. The second was to disseminate the knowledge gained through established Technology Transfer mechanisms to support DOE's programmatic objectives of increasing domestic oil production and reducing abandonment of oil fields.

  19. Post Waterflood CO2 Miscible Flood in Light Oil, Fluvial-Dominated Deltaic Reservoir (Pre-Work and Project Proposal), Class I

    SciTech Connect

    Bou-Mikael, Sami

    2002-02-05

    This project outlines a proposal to improve the recovery of light oil from waterflooded fluvial dominated deltaic (FDD) reservoir through a miscible carbon dioxide (CO2) flood. The site is the Port Neches Field in Orange County, Texas. The field is well explored and well exploited. The project area is 270 acres within the Port Neches Field.

  20. [Research on population structure and distribution characteristic of indigenous microorganism in post-polymer-flooding oil reservoir].

    PubMed

    Zhao, Ling-Xia; Gao, Pei-Ke; Cao, Mei-Na; Gao, Meng-Li; Li, Guo-Qiang; Zhu, Xu-Dong; Ma, Ting

    2012-02-01

    Denaturing gradient gel electrophoresis (DGGE) method and principal component analysis (PCA) method were used to analyze the structures of microorganism population in injection wells and production wells of a post-polymer-flooding oil reservoir in Daqing oil field. The results showed that the dominant species in injection wellhead were aerobic bacteria Pseudomonas and Acinenobacter. Facultative anaerobic bacteria Enterbacter was the dominant bacteria in near area of injection wells. Bacteria detected in production wells included Thauera, Clostridia, Pseudomonas, Petrobacter and some uncultured bacteria. Methanosaeta turned out to be the only archaea detected in injection wells, which was an aceticlastic methane-producing archaeon. Archaea detected in production wells consisted of Methanomicrobium, Methanospirillum and Methanobacterium. In general, aerobic bacteria, facultative anaerobe, and strictly anaerobic bacteria distributed successively from injection wells to production wells in this block. The dominant populations of archaea were different between injection wells and production wells, while were influenced by different environments and microbial metabolism products. PMID:22509607

  1. Assessing the role of large wood entrained in the 2013 Colorado Front Range flood in ongoing channel response and reservoir management

    NASA Astrophysics Data System (ADS)

    Bennett, Georgina; Rathburn, Sara; Ryan, Sandra; Wohl, Ellen; Blair, Aaron

    2016-04-01

    Considerable quantities of large wood (LW) may be entrained during floods with long lasting impacts on channel morphology, sediment and LW export, and downstream reservoir management. Here we present an analysis of LW entrained by an extensive flood in Colorado, USA. Over a 5 day period commencing 9th September 2013, up to 450 mm of rain, or ~1000% of the monthly average, fell in catchments spanning a 100-km-wide swath of the Colorado Front Range resulting in major flooding. Catchment response was dramatic, with reports of 100s - 1000s of years of erosion, destruction of infrastructure and homes, and sediment and LW loading within reservoirs. One heavily impacted catchment is the North St Vrain, draining 250km2 of the South Platte drainage basin. In addition to widespread channel enlargement, remote imagery reveals hundreds of landslides that delivered sediment and LW to the channel and ultimately to Ralph Price Reservoir, which provides municipal water to Longmont. The City of Longmont facilitated the removal of ~1050 m3 of wood deposited at the reservoir inlet by the flood but the potential for continued movement of large wood in the catchment presents an on-going concern for reservoir management. In collaboration with the City of Longmont, our objectives are (1) to quantify the volume of wood entrained by the flood and still stored along the channel, (2) characterize the size and distribution of LW deposits and (3) determine their role in ongoing catchment flood response and recovery. We utilize freely available pre and post flood NAIP 4-band imagery to calculate a normalized differential vegetation index (NDVI) difference map with which we calculate the area of vegetation entrained by the flood. We combine this with field assessments and a map of vegetation type automatically classified from optical satellite imagery to estimate the total flood-entrained volume of wood. Preliminary testing of 'stream selfies' - structure from motion imaging of LW deposits using

  2. Improved Miscible Nitrogen Flood Performance Utilizing Advanced Reservoir Characterization and Horizontal Laterals in a Class I Reservoir - East Binger (Marchand) Unit

    SciTech Connect

    Joe Sinner

    2006-06-30

    The reservoir characterization and investigation of the benefits of horizontal wells in the East Binger Unit miscible nitrogen flood as been completed. A significant work program was implemented from 2002 to 2005 in an effort to reduce gas cycling and economically increase ultimate oil recovery. Horizontal and vertical infill wells were drilled and existing producers were converted to injection. Due to successful infill drilling based on the improved flow characterization, more drilling was done than originally planned, and further drilling will occur after the project is completed. Through the drilling of wells and reservoir characterization work, it was determined that poor areal sweep efficiency is the primary factor causing nitrogen cycling and limiting oil recovery. This is in contrast to the perception prior to the initiation of development, which was that gravity segregation was causing poor vertical sweep efficiency. Although not true of all infill wells, most were drilled in areas with little sweep and came online producing gas with much lower nitrogen contents than previously drilled wells in the field and in the pilot area. Seven vertical and three horizontal wells were drilled in the pilot area throughout the project. As previously reported, the benefits of horizontal drilling were found to be insufficient to justify their increased cost. Nitrogen recycle, defined as nitrogen production as a percentage of injection, decreased from 72% prior to initiation of the project to about 25% before rising back to a current rate of 40%. Injection into the pilot area, despite being limited at times by problems in the Air Separation Unit of the Nitrogen Management Facility, increased 60% over levels prior to the project. Meanwhile, gas production and nitrogen content of produced gas both decreased.

  3. Selection of reservoirs amenable to micellar flooding. First annual report, October 1978-December 1979

    SciTech Connect

    Goldburg, A.; Price, H.

    1980-12-01

    The overall project objective is to build a solid engineering base upon which the Department of Energy (DOE) can improve and accelerate the application of micellar-polymer recovery technology to Mid-Continent and California sandstone reservoirs. The purpose of the work carried out under these two contracts is to significantly aid, both DOE and the private sector, in gaining the following Project Objectives: to select the better micellar-polymer prospects in the Mid-Continent and California regions; to assess all of the available field and laboratory data which has a bearing on recovering oil by micellar-polymer projects in order to help identify and resolve both the technical and economic constraints relating thereto; and to design and analyze improved field pilots and tests and to develop a micellar-polymer applications matrix for use by the potential technology users; i.e., owner/operators. The report includes the following: executive summary and project objectives; development of a predictive model for economic evaluation of reservoirs; reservoir data bank for micellar-polymer recovery evaluation; PECON program for preliminary economic evaluation; ordering of candidate reservoirs for additional data acquisition; validation of predictive model by numerical simulation; and work forecast. Tables, figures and references are included.

  4. Investigation of biosurfactant-producing indigenous microorganisms that enhance residue oil recovery in an oil reservoir after polymer flooding.

    PubMed

    She, Yue-Hui; Zhang, Fan; Xia, Jing-Jing; Kong, Shu-Qiong; Wang, Zheng-Liang; Shu, Fu-Chang; Hu, Ji-Ming

    2011-01-01

    Three biosurfactant-producing indigenous microorganisms (XDS1, XDS2, XDS3) were isolated from a petroleum reservoir in the Daqing Oilfield (China) after polymer flooding. Their metabolic, biochemical, and oil-degradation characteristics, as well as their oil displacement in the core were studied. These indigenous microorganisms were identified as short rod bacillus bacteria with white color, round shape, a protruding structure, and a rough surface. Strains have peritrichous flagella, are able to produce endospores, are sporangia, and are clearly swollen and terminal. Bacterial cultures show that the oil-spreading values of the fermentation fluid containing all three strains are more than 4.5 cm (diameter) with an approximate 25 mN/m surface tension. The hydrocarbon degradation rates of each of the three strains exceeded 50%, with the highest achieving 84%. Several oil recovery agents were produced following degradation. At the same time, the heavy components of crude oil were degraded into light components, and their flow characteristics were also improved. The surface tension and viscosity of the crude oil decreased after being treated by the three strains of microorganisms. The core-flooding tests showed that the incremental oil recoveries were 4.89-6.96%. Thus, XDS123 treatment may represent a viable method for microbial-enhanced oil recovery. PMID:20652442

  5. Scale-up of miscible flood processes for heterogeneous reservoirs. Second annual report

    SciTech Connect

    Orr, F.M. Jr.

    1995-03-01

    Progress is reported for a comprehensive investigation of the scaling behavior of gas injection processes in heterogeneous reservoirs. The interplay of phase behavior, viscous fingering, gravity segregation, capillary imbibition and drainage, and reservoir heterogeneity is examined in a series of simulations and experiments. Use of streamtube to model multiphase flow is demonstrated to be a fast and accurate approach for displacements that are dominated by reservoir heterogeneity. The streamtube technique is particularly powerful for multiphase compositional displacements because it represents the effects of phase behavior with a one-dimensional flow and represents the effects of heterogeneity through the locations of streamtubes. A new approach for fast calculations of critical tie-lines directly from criticality conditions is reported. A global triangular structure solution for four-component flow systems, whose tie-lies meet at the edge of a quaternary phase diagram or lie in planes is presented. Also demonstrated is the extension of this solution to multicomponent systems under the same assumptions. The interplay of gravity, capillary and viscous forces on final residual oil saturation is examined experimentally and theoretically. The analysis of vertical equilibrium conditions for three-phase gravity drainage shows that almost all oil can be recovered from the top part of a reservoir. The prediction of spreading and stability of thin film is performed to investigate three-phase gravity drainage mechanisms. Finally, experimental results from gravity drainage of crude oil in the presence of CO{sub 2} suggest that gravity drainage could be an efficient oil recovery process for vertically fractured reservoirs.

  6. 33 CFR 239.7 - Separation of flood control works from urban drainage.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... from urban drainage. 239.7 Section 239.7 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT... COVERED FLOOD CONTROL CHANNELS § 239.7 Separation of flood control works from urban drainage. Covered channels are likely to be considered in boundary areas demarking urban drainage and flood...

  7. 33 CFR 239.7 - Separation of flood control works from urban drainage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... from urban drainage. 239.7 Section 239.7 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT... COVERED FLOOD CONTROL CHANNELS § 239.7 Separation of flood control works from urban drainage. Covered channels are likely to be considered in boundary areas demarking urban drainage and flood...

  8. 33 CFR 239.7 - Separation of flood control works from urban drainage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... from urban drainage. 239.7 Section 239.7 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT... COVERED FLOOD CONTROL CHANNELS § 239.7 Separation of flood control works from urban drainage. Covered channels are likely to be considered in boundary areas demarking urban drainage and flood...

  9. 33 CFR 239.7 - Separation of flood control works from urban drainage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... from urban drainage. 239.7 Section 239.7 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT... COVERED FLOOD CONTROL CHANNELS § 239.7 Separation of flood control works from urban drainage. Covered channels are likely to be considered in boundary areas demarking urban drainage and flood...

  10. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  11. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  12. 33 CFR 203.48 - Inspection guidelines for non-Federal flood control works.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Federal flood control works. 203.48 Section 203.48 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.48 Inspection guidelines for non-Federal...

  13. 33 CFR 203.48 - Inspection guidelines for non-Federal flood control works.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Federal flood control works. 203.48 Section 203.48 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.48 Inspection guidelines for non-Federal...

  14. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  15. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  16. 33 CFR 203.48 - Inspection guidelines for non-Federal flood control works.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Federal flood control works. 203.48 Section 203.48 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.48 Inspection guidelines for non-Federal...

  17. 33 CFR 203.50 - Nonstructural alternatives to rehabilitation of flood control works.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... adherence to, Executive Order 11988, Floodplain Management, 3 CFR 117 (1977 Compilation), or as it may be... rehabilitation of flood control works. 203.50 Section 203.50 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal...

  18. 33 CFR 203.48 - Inspection guidelines for non-Federal flood control works.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Federal flood control works. 203.48 Section 203.48 Navigation and Navigable Waters CORPS OF ENGINEERS... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.48 Inspection guidelines for non-Federal...

  19. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  20. A real-time control framework for urban water reservoirs operation

    NASA Astrophysics Data System (ADS)

    Galelli, S.; Goedbloed, A.; Schwanenberg, D.

    2012-04-01

    computational requests and the capability of exploiting real-time hydro-meteorological information, which are crucial for an effective operation of these fast-varying hydrological systems. The framework is here demonstrated on the operation of Marina Reservoir (Singapore), whose recent construction in late 2008 increased the effective catchment area to about 50% of the total available. Its operation, which accounts for drinking water supply, flash floods control and water quality standards, is here designed by combining the MPC scheme with the process-based hydrological model SOBEK. Extensive simulation experiments show the validity of the proposed framework.

  1. PH Sensitive Polymers for Improving Reservoir Sweep and Conformance Control in Chemical Flooring

    SciTech Connect

    Mukul Sharma; Steven Bryant; Chun Huh

    2008-03-31

    There is an increasing opportunity to recover bypassed oil from depleted, mature oilfields in the US. The recovery factor in many reservoirs is low due to inefficient displacement of the oil by injected fluids (typically water). The use of chemical flooding methods to increase recovery efficiencies is severely constrained by the inability of the injected chemicals to contact the bypassed oil. Low sweep efficiencies are the primary cause of low oil recoveries observed in the field in chemical flooding operations even when lab studies indicate high oil recovery efficiency. Any technology that increases the ability of chemical flooding agents to better contact the remaining oil and reduce the amount of water produced in conjunction with the produced oil will have a significant impact on the cost of producing oil domestically in the US. This translates directly into additional economically recoverable reserves, which extends the economic lives of marginal and mature wells. The objective of this research project was to develop a low-cost, pH-triggered polymer for use in IOR processes to improve reservoir sweep efficiency and reservoir conformance in chemical flooding. Rheological measurements made on the polymer solution, clearly show that it has a low viscosity at low pH and exhibits a sudden increase in viscosity (by 2 orders of magnitude or more) at a pH of 3.5 to 4. This implies that the polymer would preferentially flow into zones containing water since the effective permeability to water is highest in these zones. As the pH of the zone increases due to the buffering capacity of the reservoir rock, the polymer solution undergoes a liquid to gel transition causing a sharp increase in the viscosity of the polymer solution in these zones. This allows operationally robust, in-depth conformance treatment of such water bearing zones and better mobility control. The rheological properties of HPAM solutions were measured. These include: steady-shear viscosity and

  2. Post Waterflood CO{sub 2} Miscible Flood in Light Oil Fluvial-Dominated Deltaic Reservoirs

    SciTech Connect

    1996-04-30

    Texaco terminated the CO{sub 2} purchase agreement with Cardox due to the declining production from the project during 1995. This decision was supported by the DOE and the Exploration and Production Technology Department (EPTD) who developed the model to simulate reservoir performance. Texaco is planning to continue recycling produced CO{sub 2} to recover the remaining 400 MBO from the Marg Area 1 reservoir. Currently one well is remaining on production Kuhn {number_sign}15R after the second producing well Kuhn {number_sign}38 sanded up. Changing the water and CO{sub 2} injection patterns should improve the sweep efficiency and restore production from other existing wells.

  3. Analysis of microbial communities in the oil reservoir subjected to CO2-flooding by using functional genes as molecular biomarkers for microbial CO2 sequestration

    PubMed Central

    Liu, Jin-Feng; Sun, Xiao-Bo; Yang, Guang-Chao; Mbadinga, Serge M.; Gu, Ji-Dong; Mu, Bo-Zhong

    2015-01-01

    Sequestration of CO2 in oil reservoirs is considered to be one of the feasible options for mitigating atmospheric CO2 building up and also for the in situ potential bioconversion of stored CO2 to methane. However, the information on these functional microbial communities and the impact of CO2 storage on them is hardly available. In this paper a comprehensive molecular survey was performed on microbial communities in production water samples from oil reservoirs experienced CO2-flooding by analysis of functional genes involved in the process, including cbbM, cbbL, fthfs, [FeFe]-hydrogenase, and mcrA. As a comparison, these functional genes in the production water samples from oil reservoir only experienced water-flooding in areas of the same oil bearing bed were also analyzed. It showed that these functional genes were all of rich diversity in these samples, and the functional microbial communities and their diversity were strongly affected by a long-term exposure to injected CO2. More interestingly, microorganisms affiliated with members of the genera Methanothemobacter, Acetobacterium, and Halothiobacillus as well as hydrogen producers in CO2 injected area either increased or remained unchanged in relative abundance compared to that in water-flooded area, which implied that these microorganisms could adapt to CO2 injection and, if so, demonstrated the potential for microbial fixation and conversion of CO2 into methane in subsurface oil reservoirs. PMID:25873911

  4. Analysis of microbial communities in the oil reservoir subjected to CO2-flooding by using functional genes as molecular biomarkers for microbial CO2 sequestration.

    PubMed

    Liu, Jin-Feng; Sun, Xiao-Bo; Yang, Guang-Chao; Mbadinga, Serge M; Gu, Ji-Dong; Mu, Bo-Zhong

    2015-01-01

    Sequestration of CO2 in oil reservoirs is considered to be one of the feasible options for mitigating atmospheric CO2 building up and also for the in situ potential bioconversion of stored CO2 to methane. However, the information on these functional microbial communities and the impact of CO2 storage on them is hardly available. In this paper a comprehensive molecular survey was performed on microbial communities in production water samples from oil reservoirs experienced CO2-flooding by analysis of functional genes involved in the process, including cbbM, cbbL, fthfs, [FeFe]-hydrogenase, and mcrA. As a comparison, these functional genes in the production water samples from oil reservoir only experienced water-flooding in areas of the same oil bearing bed were also analyzed. It showed that these functional genes were all of rich diversity in these samples, and the functional microbial communities and their diversity were strongly affected by a long-term exposure to injected CO2. More interestingly, microorganisms affiliated with members of the genera Methanothemobacter, Acetobacterium, and Halothiobacillus as well as hydrogen producers in CO2 injected area either increased or remained unchanged in relative abundance compared to that in water-flooded area, which implied that these microorganisms could adapt to CO2 injection and, if so, demonstrated the potential for microbial fixation and conversion of CO2 into methane in subsurface oil reservoirs. PMID:25873911

  5. Operation of TVA reservoirs. Annual 1979

    SciTech Connect

    Not Available

    1982-04-01

    Data for 1979 on the operation of TVA reservoirs for flood control, power generation and navigational purposes are reported. The operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1979 is described. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Any reference in this report to all reservoirs in the Tennessee or Cumberland River Basins refer to these specific reservoirs. Tabulated data are included on: reservation elevation and storage volume; turbine and gate discharges; and head water elevation. (LCL)

  6. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect

    Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Liu, Jin; Wavrik, Kathryn

    1999-09-27

    This report describes work performed during the first year of the project, ''Using Chemicals to Optimize Conformance Control in Fractured Reservoirs.'' This research project has three objectives. The first objective is to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective is to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective is to develop procedures to optimize blocking agent placement in naturally fractured reservoirs. This research project consists of three tasks, each of which addresses one of the above objectives. Our work is directed at both injection wells and production wells and at vertical, horizontal, and highly deviated wells.

  7. Scale-up of miscible flood processes for heterogeneous reservoirs. 1993 annual report

    SciTech Connect

    Orr, F.M. Jr.

    1994-05-01

    Progress is reported for a comprehensive investigation of the scaling behavior of gas injection processes in heterogeneous reservoirs. The interplay of phase behavior, viscous fingering, gravity segregation, capillary imbibition and drainage, and reservoir heterogeneity is examined in a series of simulations and experiments. Compositional and first-contact miscable simulations of viscous fingering and gravity segregation are compared to show that the two techniques can give very different results. Also, analyzed are two-dimensional and three-dimensional flows in which gravity segregation and viscous fingering interact. The simulations show that 2D and 3D flows can differ significantly. A comparison of analytical solutions for three-component two-phase flow with experimental results for oil/water/alcohol systems is reported. While the experiments and theory show reasonable agreement, some differences remain to be explained. The scaling behavior of the interaction of gravity segregation and capillary forces is investigated through simulations and through scaling arguments based on analysis of the differential equations. The simulations show that standard approaches do not agree well with results of low IFT displacements. The scaling analyses, however, reveal flow regimes where capillary, gravity, or viscous forces dominate the flow.

  8. Impact of treated wastewater reuse and floods on water quality and fish health within a water reservoir in an arid climate.

    PubMed

    Zaibel, Inbal; Zilberg, Dina; Groisman, Ludmila; Arnon, Shai

    2016-07-15

    Treated wastewater (TWW) reuse for agricultural irrigation is a well-established approach to coping with water shortages in semi-arid and arid environments. Recently, additional uses of TWW have emerged, including streamflow augmentation and aquatic ecosystem restoration. The purpose of the current study was to evaluate the water quality and fish health, in an artificial reservoir located in an arid climate (the Yeruham Reservoir, Israel), which regularly receives TWW and sporadic winter floods. The temporal distribution of water levels, nutrients and organic micropollutants (OMPs) were measured during the years 2013-2014. OMPs were also measured in sediment and fish tissues. Finally, the status of fish health was evaluated by histopathology. Water levels and quality were mainly influenced by seasonal processes such as floods and evaporation, and not by the discharge of TWW. Out of 16 tested OMPs, estrone, carbamazepine, diclofenac and bezafibrate were found in the reservoir water, but mostly at concentrations below the predicted no-effect concentration (PNEC) for fish. Concentrations of PCBs and dioxins in fish muscle and liver were much lower than the EU maximal permitted concentrations, and similar to concentrations that were found in food fish in Israel and Europe. In the histopathological analysis, there were no evident tissue abnormalities, and low to moderate infection levels of fish parasites were recorded. The results from the Yeruham Reservoir demonstrated a unique model for the mixture effect between TWW reuse and natural floods to support a unique stable and thriving ecosystem in a water reservoir located in an arid region. This type of reservoir can be widely used for recreation, education, and the social and economic development of a rural environment, such as has occurred in the Yeruham region. PMID:27065446

  9. The Nahal Oz Reservoir dam-break flood: Geomorphic impact on a small ephemeral loess-channel in the semi-arid Negev Desert, Israel

    NASA Astrophysics Data System (ADS)

    Bergman, Nathaniel; Sholker, Ofer; Roskin, Joel; Greenbaum, Noam

    2014-04-01

    The Nahal Oz Reservoir — in the coastal, semi-arid southwestern Israel was designed to enhance local irrigation of crops using reclaimed sewage water during the dry summer months. On March 2001, part of the western dike of the reservoir was breached and generated a flow release of 3.5 ∗ 106 m3 of secondary irrigation water that was channeled down the 1st order ephemeral loess stream (Nahal Yare'akh). The consequent 12-hour flood surge, with an estimated peak discharge of 1000 m3s- 1, inflicted severe loess erosion, agricultural, property and infrastructural damage downstream ($6 million).

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  11. Controls on the breach geometry and flood hydrograph during overtopping of non-cohesive earthen dams

    USGS Publications Warehouse

    Walder, Joseph S.; Iverson, Richard M.; Godt, Jonathan W.; Logan, Matthew; Solovitz, Stephen A.

    2015-01-01

    Overtopping failure of non-cohesive earthen dams was investigated in 13 large-scale experiments with dams built of compacted, damp, fine-grained sand. Breaching was initiated by cutting a notch across the dam crest and allowing water escaping from a finite upstream reservoir to form its own channel. The channel developed a stepped profile, and upstream migration of the steps, which coalesced into a headcut, led to the establishment of hydraulic control (critical flow) at the channel head, or breach crest, an arcuate erosional feature that functions hydraulically as a weir. Novel photogrammetric methods, along with underwater videography, revealed that the retreating headcut maintained a slope near the angle of friction of the sand, while the cross section at the breach crest maintained a geometrically similar shape through time. That cross-sectional shape was nearly unaffected by slope failures, contrary to the assumption in many models of dam breaching. Flood hydrographs were quite reproducible--for sets of dams ranging in height from 0.55 m to 0.98 m--when the time datum was chosen as the time that the migrating headcut intersected the breach crest. Peak discharge increased almost linearly as a function of initial dam height. Early-time variability between flood hydrographs for nominally identical dams is probably a reflection of subtle experiment-to-experiment differences in groundwater hydrology and the interaction between surface water and groundwater.

  12. Electrical control of intestinal reservoirs in a chronic dog model.

    PubMed

    Grundfest-Broniatowski, S; Moritz, A; Olsen, E; Kasick, J; Ilyes, L; Jacobs, G; Nosé, Y

    1988-01-01

    Pouches constructed from small intestine are used to replace reservoir function after extirpative surgery of the colon. Such pouches empty in an involuntary and uncontrolled fashion. To see whether emptying could be voluntarily controlled, ileal and jejunal reservoirs were constructed in eight dogs under general anesthesia. Four pairs of stainless steel electrodes were attached to the serosa at 5 cm intervals, and the pouches were intubated for pressure measurements with 1.67 mm polyethylene catheters. All lines were brought subcutaneously to the neck where they were maintained under a protective jacket. One to four weeks later, the pouches were stimulated with trains of square wave pulses at frequencies between 3 Hz and 1.67 KHz. The pouches were injected with contrast, and the results were monitored by fluoroscopy. Intrapouch pressure increases as high as 80 mmHg were seen after stimulation at 3 Hz, 100 msec and 6 Hz, 50 msec (10 to 25 mA) and emptying was induced. Pressure increases were also seen after stimulation with 330 Hz, 1 msec and 10 Hz, 1 msec pulse trains, but emptying was not documented. Abdominal wall contraction during stimulation was a problem but could be inhibited by interposing an insulating silastic sheet. The conclusion was made that it is possible to electrically induce emptying of intestinal reservoirs in a chronic dog model. PMID:3196582

  13. Evaluation method to floodwater amount of difficult control and utilization in flood season for hyperconcentration rivers and its application

    NASA Astrophysics Data System (ADS)

    Li, X.

    2013-05-01

    The severe soil erosion in the Chinese Loess Plateau has resulted in high sediment concentration in runoff, which can cause tremendous pressure to the development and utilization of regional floodwater resources as well as the regional flood control and disaster mitigation. The floodwater amount of difficult control and utilization in flood season (FADCUFS) is an important part of the available amount of surface water resources. It also has a critical role in the sustainable development of water resources, especially for those hyperconcentration rivers (HRs) in the Loess Plateau. The evaluation of FADCUFS for HRs is an important issue in the field of hydrology and water resources. However, the understandings of its connotation, evaluation method, and nature are limited. Combined engineering measures with non-engineering ones, the evaluation method of FADCUFS for HRs was presented based on the angles of water quantity and quality. The method divides the FADCUFS into two parts in terms of the flood control operation characteristics of reservoir in HR and the relationship between water resources utilization and sediment in runoff, respectively. One is the amount of difficult regulation-control floodwater (DRCF), and the other is the volume of difficult utilization floodwater (DUF). A case study of the Bajiazui Reservoir, located in the typical Jinghe River (the second tributary of the Chinese Yellow River with high sediment concentration) was performed. Three typical years, wet year (1988), average year (1986), and dry years (1995 and 2000), were employed. According to the daily optimal operation model of Bajiazui Reservoir, the DRCF occurs for only the wet year instead of the average and the dry years. There are four times of DRCF with the amount of 26.74 m3/s (July 14), 14.58 m3/s (August 5), 10.27 m3/s (August 9), and 1.23 m3/s (August 12) in 1988, respectively, with a total amount of 4.56 million m3. A certain close relationship exists between the amount of DRCF

  14. Climate, orography and scale controls on flood frequency in Triveneto (Italy)

    NASA Astrophysics Data System (ADS)

    Persiano, Simone; Castellarin, Attilio; Salinas, Jose Luis; Domeneghetti, Alessio; Brath, Armando

    2016-05-01

    The growing concern about the possible effects of climate change on flood frequency regime is leading Authorities to review previously proposed reference procedures for design-flood estimation, such as national flood frequency models. Our study focuses on Triveneto, a broad geographical region in North-eastern Italy. A reference procedure for design flood estimation in Triveneto is available from the Italian NCR research project "VA.PI.", which considered Triveneto as a single homogeneous region and developed a regional model using annual maximum series (AMS) of peak discharges that were collected up to the 1980s by the former Italian Hydrometeorological Service. We consider a very detailed AMS database that we recently compiled for 76 catchments located in Triveneto. All 76 study catchments are characterized in terms of several geomorphologic and climatic descriptors. The objective of our study is threefold: (1) to inspect climatic and scale controls on flood frequency regime; (2) to verify the possible presence of changes in flood frequency regime by looking at changes in time of regional L-moments of annual maximum floods; (3) to develop an updated reference procedure for design flood estimation in Triveneto by using a focused-pooling approach (i.e. Region of Influence, RoI). Our study leads to the following conclusions: (1) climatic and scale controls on flood frequency regime in Triveneto are similar to the controls that were recently found in Europe; (2) a single year characterized by extreme floods can have a remarkable influence on regional flood frequency models and analyses for detecting possible changes in flood frequency regime; (3) no significant change was detected in the flood frequency regime, yet an update of the existing reference procedure for design flood estimation is highly recommended and we propose the RoI approach for properly representing climate and scale controls on flood frequency in Triveneto, which cannot be regarded as a single

  15. Flood control and loss estimation for paddy field at midstream of Chao Phraya River Basin, Thailand

    NASA Astrophysics Data System (ADS)

    Cham, T. C.; Mitani, Y.

    2015-09-01

    2011 Thailand flood has brought serious impact to downstream of Chao Phraya River Basin. The flood peak period started from August, 2011 to the end of October, 2011. This research focuses on midstream of Chao Phraya River Basin, which is Nakhon Sawan area includes confluence of Nan River and Yom River, also confluence of Ping River and Nan River. The main purpose of this research is to understand the flood generation, estimate the flood volume and loss of paddy field, also recommends applicable flood counter measurement to ease the flood condition at downstream of Chao Phraya River Basin. In order to understand the flood condition, post-analysis is conducted at Nakhon Sawan. The post-analysis consists of field survey to measure the flood marks remained and interview with residents to understand living condition during flood. The 2011 Thailand flood generation at midstream is simulated using coupling of 1D and 2D hydrodynamic model to understand the flood generation during flood peak period. It is calibrated and validated using flood marks measured and streamflow data received from Royal Irrigation Department (RID). Validation of results shows good agreement between simulated result and actual condition. Subsequently, 3 scenarios of flood control are simulated and Geographic Information System (GIS) is used to assess the spatial distribution of flood extent and reduction of loss estimation at paddy field. In addition, loss estimation for paddy field at midstream is evaluated using GIS with the calculated inundation depth. Results show the proposed flood control at midstream able to minimize 5% of the loss of paddy field in 26 provinces.

  16. Controls on the Karaha-Telaga Bodas geothermal reservoir, Indonesia

    USGS Publications Warehouse

    Nemcok, M.; Moore, J.N.; Christensen, Carl; Allis, R.; Powell, T.; Murray, B.; Nash, G.

    2007-01-01

    Karaha-Telaga Bodas is a partially vapor-dominated, fracture-controlled geothermal system located adjacent to Galunggung Volcano in western Java, Indonesia. The geothermal system consists of: (1) a caprock, ranging from several hundred to 1600 m in thickness, and characterized by a steep, conductive temperature gradient and low permeability; (2) an underlying vapor-dominated zone that extends below sea level; and (3) a deep liquid-dominated zone with measured temperatures up to 353 ??C. Heat is provided by a tabular granodiorite stock encountered at about 3 km depth. A structural analysis of the geothermal system shows that the effective base of the reservoir is controlled either by the boundary between brittle and ductile deformational regimes or by the closure and collapse of fractures within volcanic rocks located above the brittle/ductile transition. The base of the caprock is determined by the distribution of initially low-permeability lithologies above the reservoir; the extent of pervasive clay alteration that has significantly reduced primary rock permeabilities; the distribution of secondary minerals deposited by descending waters; and, locally, by a downward change from a strike-slip to an extensional stress regime. Fluid-producing zones are controlled by both matrix and fracture permeabilities. High matrix permeabilities are associated with lacustrine, pyroclastic, and epiclastic deposits. Productive fractures are those showing the greatest tendency to slip and dilate under the present-day stress conditions. Although the reservoir appears to be in pressure communication across its length, fluid, and gas chemistries vary laterally, suggesting the presence of isolated convection cells. ?? 2006 CNR.

  17. Reservoir floodplains support distinct fish assemblages

    USGS Publications Warehouse

    Miranda, Leandro E.; Wigen, S. L.; Dagel, Jonah D.

    2014-01-01

    Reservoirs constructed on floodplain rivers are unique because the upper reaches of the impoundment may include extensive floodplain environments. Moreover, reservoirs that experience large periodic water level fluctuations as part of their operational objectives seasonally inundate and dewater floodplains in their upper reaches, partly mimicking natural inundations of river floodplains. In four flood control reservoirs in Mississippi, USA, we explored the dynamics of connectivity between reservoirs and adjacent floodplains and the characteristics of fish assemblages that develop in reservoir floodplains relative to those that develop in reservoir bays. Although fish species richness in floodplains and bays were similar, species composition differed. Floodplains emphasized fish species largely associated with backwater shallow environments, often resistant to harsh environmental conditions. Conversely, dominant species in bays represented mainly generalists that benefit from the continuous connectivity between the bay and the main reservoir. Floodplains in the study reservoirs provided desirable vegetated habitats at lower water level elevations, earlier in the year, and more frequently than in bays. Inundating dense vegetation in bays requires raising reservoir water levels above the levels required to reach floodplains. Therefore, aside from promoting distinct fish assemblages within reservoirs and helping promote diversity in regulated rivers, reservoir floodplains are valued because they can provide suitable vegetated habitats for fish species at elevations below the normal pool, precluding the need to annually flood upland vegetation that would inevitably be impaired by regular flooding. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  18. Optimal control of diarrhea transmission in a flood evacuation zone

    NASA Astrophysics Data System (ADS)

    Erwina, N.; Aldila, D.; Soewono, E.

    2014-03-01

    Evacuation of residents and diarrhea disease outbreak in evacuation zone have become serious problem that frequently happened during flood periods. Limited clean water supply and infrastructure in evacuation zone contribute to a critical spread of diarrhea. Transmission of diarrhea disease can be reduced by controlling clean water supply and treating diarrhea patients properly. These treatments require significant amount of budget, which may not be fulfilled in the fields. In his paper, transmission of diarrhea disease in evacuation zone using SIRS model is presented as control optimum problem with clean water supply and rate of treated patients as input controls. Existence and stability of equilibrium points and sensitivity analysis are investigated analytically for constant input controls. Optimum clean water supply and rate of treatment are found using optimum control technique. Optimal results for transmission of diarrhea and the corresponding controls during the period of observation are simulated numerically. The optimum result shows that transmission of diarrhea disease can be controlled with proper combination of water supply and rate of treatment within allowable budget.

  19. Mechanistic Processes Controlling Gas Sorption in Shale Reservoirs

    NASA Astrophysics Data System (ADS)

    Schaef, T.; Loring, J.; Ilton, E. S.; Davidson, C. L.; Owen, T.; Hoyt, D.; Glezakou, V. A.; McGrail, B. P.; Thompson, C.

    2014-12-01

    Utilization of CO2 to stimulate natural gas production in previously fractured shale-dominated reservoirs where CO2 remains in place for long-term storage may be an attractive new strategy for reducing the cost of managing anthropogenic CO2. A preliminary analysis of capacities and potential revenues in US shale plays suggests nearly 390 tcf in additional gas recovery may be possible via CO2 driven enhanced gas recovery. However, reservoir transmissivity properties, optimum gas recovery rates, and ultimate fate of CO2 vary among reservoirs, potentially increasing operational costs and environmental risks. In this paper, we identify key mechanisms controlling the sorption of CH4 and CO2 onto phyllosilicates and processes occurring in mixed gas systems that have the potential of impacting fluid transfer and CO2 storage in shale dominated formations. Through a unique set of in situ experimental techniques coupled with molecular-level simulations, we identify structural transformations occurring to clay minerals, optimal CO2/CH4 gas exchange conditions, and distinguish between adsorbed and intercalated gases in a mixed gas system. For example, based on in situ measurements with magic angle spinning NMR, intercalation of CO2 within the montmorillonite structure occurs in CH4/CO2 gas mixtures containing low concentrations (<5 mol%) of CO2. A stable montmorillonite structure dominates during exposure to pure CH4 (90 bar), but expands upon titration of small fractions (1-3 mol%) of CO2. Density functional theory was used to quantify the difference in sorption behavior between CO2 and CH4 and indicates complex interactions occurring between hydrated cations, CH4, and CO2. The authors will discuss potential impacts of these experimental results on CO2-based hydrocarbon recovery processes.

  20. The Nahal Oz Reservoir dam-break flood: Geomorphic impact on a small ephemeral loess-channel in the semi-arid Negev Desert, Israel

    NASA Astrophysics Data System (ADS)

    Roskin, Joel; Bergman, Nathaniel; Shaulker, Ofer; Greenbaum, Noam

    2014-05-01

    The Nahal Oz Reservoir - in the coastal, semi-arid southwestern Israel was designed to enhance local irrigation of crops using reclaimed sewage water during the dry summer months. On March 2001, part of the western dike of the reservoir was breached and generated a flow release of 3.5*106 m3 of secondary irrigation water that was channeled down the 1st order ephemeral loess stream (Nahal Yare'akh). The consequent 12-hour flood surge, with an estimated peak discharge of 1000 m3s-1, inflicted severe loess erosion, agricultural, property and infrastructural damage downstream. Post-flood mapping documented the geomorphic response to the flood which included channel scour and widening along the initial 2 km downstream of the reservoir where a spillway channel was formed. The increase in the cross-sectional area was about 60% and had an estimated 170,000 m3 of sediment bed, bank and floodplain erosion. Calculated maximum shear stress and stream power along this section are estimated at 300 Nm-2 and 900 wm-2, respectively. The peak discharge at the end of this segment was estimated at 800 m3s-1 indicating only minor attenuation along this segment. Two km downstream of the breach, a wide braided fan indicated deposition of the eroded sediments. At the end of this segment the floodwater diverged into several watercourses and inundated tilled agricultural fields and neighborhoods. Downstream, 9 km from the reservoir, the discharge attenuated to 100 m3s-1, slightly above bankfull. Further downstream and upon reaching the large Shikma stream the flow was already very low. This reduction in discharge is attributed to the anthropogenic infrastructure - roads, neighborhoods and agricultural fields and the large transmission losses typical of sandy ephemeral streams. The study shows that channels within erodible materials respond to high peak discharges very locally. Erosional thresholds that severely incised the channel are only maintained for 2 km below the breached reservoir

  1. Fault controlled geochemical properties in Lahendong geothermal reservoir Indonesia

    NASA Astrophysics Data System (ADS)

    Brehme, Maren; Deon, Fiorenza; Haase, Christoph; Wiegand, Bettina; Kamah, Yustin; Sauter, Martin; Regenspurg, Simona

    2016-03-01

    Rock and fluid geochemical data from Lahendong, Indonesia, were analyzed to evaluate the influence of fault zones on reservoir properties. It was found that these properties depend on fault-permeability controlled fluid flow. Results from measurements of spring and well water as well as rocks and their hydraulic properties were combined with hydrochemical numerical modeling. The models show that the geothermal field consists of two geochemically distinct reservoir sections. One section is characterized by acidic water, considerable gas discharge and high geothermal-power productivity—all related to increased fault zone permeability. The other section is characterized by neutral water and lower productivity. Increased fluid flow in the highly fractured and permeable areas enhances chemical reaction rates. This results in strong alteration of their surrounding rocks. Numerical models of reactions between water and rock at Lahendong indicate the main alteration products are clay minerals. A geochemical conceptual model illustrates the relation between geochemistry and permeability and their distribution within the area. Our conceptual model illustrates the relation between geochemistry and fault-zone permeability within the Lahendong area. Further mapping of fault-related permeability would support sustainable energy exploitation by avoiding low-productive wells or the production of highly corroding waters, both there and elsewhere in the world.

  2. Tsetse Fly Control in Kenya's Spatially and Temporally Dynamic Control Reservoirs: A Cost Analysis

    PubMed Central

    McCord, Paul F.; Messina, Joseph P.; Campbell, David J.; Grady, Sue C.

    2011-01-01

    Human African trypanosomiasis (HAT) and animal African trypanosomiasis (AAT) are significant health concerns throughout much of sub-Saharan Africa. Funding for tsetse fly control operations has decreased since the 1970s, which has in turn limited the success of campaigns to control the disease vector. To maximize the effectiveness of the limited financial resources available for tsetse control, this study develops and analyzes spatially and temporally dynamic tsetse distribution maps of Glossina subgenus Morsitans populations in Kenya from January 2002 to December 2010, produced using the Tsetse Ecological Distribution Model. These species distribution maps reveal seasonal variations in fly distributions. Such variations allow for the identification of “control reservoirs” where fly distributions are spatially constrained by fluctuations in suitable habitat and tsetse population characteristics. Following identification of the control reservoirs, a tsetse management operation is simulated in the control reservoirs using capital and labor control inputs from previous studies. Finally, a cost analysis, following specific economic guidelines from existing tsetse control analyses, is conducted to calculate the total cost of a nationwide control campaign of the reservoirs compared to the cost of a nationwide campaign conducted at the maximum spatial extent of the fly distributions from January 2002 to December 2010. The total cost of tsetse management within the reservoirs sums to $14,212,647, while the nationwide campaign at the maximum spatial extent amounts to $33,721,516. This savings of $19,508,869 represents the importance of identifying seasonally dynamic control reservoirs when conducting a tsetse management campaign, and, in the process, offers an economical means of fly control and disease management for future program planning. PMID:22581989

  3. Crash tests for forward-looking flood control in the city of Zürich (Switzerland)

    NASA Astrophysics Data System (ADS)

    Zappa, M.; Andres, N.; Kienzler, P.; Näf-Huber, D.; Marti, C.; Oplatka, M.

    2015-06-01

    Floods in the city of Zürich (Switzerland) were already reported in the 13th century. The most severe threat are floods from the Sihl river (336 km2, including also an hydropower reservoir) with peaks exceeding 350 m3 s-1. An assessment using a rainfall-runoff model has been completed to evaluate extreme flood situations by combining 18 precipitation scenarios with different initial conditions. These scenarios identified deficits for the safety of Zürich. For the improvement of flood management several measures are possible. Crash-tests with 41 472 combinations of measures and scenarios have been evaluated. According to the results, the spillway channel option in the downstream reach of the Sihl is a promising structural measure to ensure flood relief for Zürich. Lowering the artificial reservoir lake before the event consistently increases safety also in the upstream part, but causes financial losses in terms of hydroelectricity. The combination of measures can lead to an optimal safety also in case of unfavourable initial conditions. Pending questions concern the costs, political decisions and the environmental sustainability.

  4. Mobility control in oil recovery by chemical flooding: State-of-the-art review: Topical report. [177 references

    SciTech Connect

    Gao, H.W.

    1987-01-01

    Mobility control in oil recovery by chemical flooding (polymer, micellar-polymer, and alkaline-polymer) can be achieved through the use of low-concentration water-soluble polymers in water or in chemical slugs. Since the late 1950's, water-soluble polymers have been studied extensively in laboratories by many researchers and widely used in many chemical flooding projects to improve sweep efficiency and increase ultimate oil recovery. Effective use of polymers as mobility control agents requires the understanding of the stability of polymers and their rheological behavior in reservoirs. An overview of the scientific literature on the application of water-soluble polymers in enhanced oil recovery (EOR) is presented. The processes, factors, and mechanisms that influence the stability of polymers and those that cause a reduction in water mobility are discussed. Existing knowledge of polymer flow behavior in porous media, and of surfactant-polymer interactions is reviewed. Also discussed are the case histories of 23 chemical flooding field projects. 177 refs., 6 figs., 5 tabs.

  5. Mobility Controlled Flooding (MCF) Technology for Enhanced Sweeping and NAPL Remediation in Heterogeneous Systems

    NASA Astrophysics Data System (ADS)

    Zhong, L.; Oostrom, M.; Wietsma, T.

    2005-12-01

    Heterogeneity is often encountered in subsurface contamination characterization and remediation. Low-permeability zones are bypassed when remedial fluid is injected into heterogeneous systems. The contaminant in the bypassed areas is therefore untouched by the remedial fluid, which can prolong the remediation operations significantly. Methods of forcing fluids into low-permeability flow paths have been developed and widely implemented to solve the heterogeneity-induced bypassing problem encountered during oil recovery in the petroleum industry over the past 40 years. Since the intent of the petroleum reservoir engineers is to control the mobility of the injected fluid in the high-permeable zones so that the fluid can be pushed through the low-permeable zones to contact and mobilize the remaining oil in these zones, this method are referred as mobility controlled flooding (MCF) technology in the petroleum engineering literature. Two methods of mobility control have been developed. One method is to use a water-soluble polymer to increase the viscosity of the injectate so that the in situ pore pressure is raised, and cross-flow between layers with different permeability occurs. The other method is to use surfactant-foam flood to generate foam in high permeable zones in situ; therefore, the injected fluid is forced into the low-permeable areas. A water-soluble polymer, xanthan gum, and surfactant MA-80 was used to formulate MCF remedial fluids to remediate nonaqueous phase liquid (NAPL) contaminated heterogonous systems in two-dimensional (2-D) flow-cell (40 by 50 by 5 cm) experiments. It was demonstrated that the MCF technology is capable of sweeping the low-permeability flow paths. The bypassing of low-permeable zones was significantly reduced. The removal of NAPL trapped in the low-perm zones was remarkable enhanced attributed to more efficient NAPL mobilization. The results also indicate that the MCF technology is able to manage the fluid density effects. The

  6. Comparison of Microbial Community Compositions of Injection and Production Well Samples in a Long-Term Water-Flooded Petroleum Reservoir

    PubMed Central

    Ren, Hong-Yan; Zhang, Xiao-Jun; Song, Zhi-yong; Rupert, Wieger; Gao, Guang-Jun; Guo, Sheng-xue; Zhao, Li-Ping

    2011-01-01

    Water flooding plays an important role in recovering oil from depleted petroleum reservoirs. Exactly how the microbial communities of production wells are affected by microorganisms introduced with injected water has previously not been adequately studied. Using denaturing gradient gel electrophoresis (DGGE) approach and 16S rRNA gene clone library analysis, the comparison of microbial communities is carried out between one injection water and two production waters collected from a working block of the water-flooded Gudao petroleum reservoir located in the Yellow River Delta. DGGE fingerprints showed that the similarities of the bacterial communities between the injection water and production waters were lower than between the two production waters. It was also observed that the archaeal composition among these three samples showed no significant difference. Analysis of the 16S rRNA gene clone libraries showed that the dominant groups within the injection water were Betaproteobacteria, Gammaproteobacteria and Methanomicrobia, while the dominant groups in the production waters were Gammaproteobacteria and Methanobacteria. Only 2 out of 54 bacterial operational taxonomic units (OTUs) and 5 out of 17 archaeal OTUs in the injection water were detected in the production waters, indicating that most of the microorganisms introduced by the injection water may not survive to be detected in the production waters. Additionally, there were 55.6% and 82.6% unique OTUs in the two production waters respectively, suggesting that each production well has its specific microbial composition, despite both wells being flooded with the same injection water. PMID:21858049

  7. The effect of controlled floods on decadal-scale changes in channel morphology and fine sediment storage in a debris-fan affected river canyon

    NASA Astrophysics Data System (ADS)

    Mueller, E. R.; Grams, P. E.; Schmidt, J. C.

    2013-12-01

    In 2011, a large magnitude flow release from Flaming Gorge Reservoir resulted in the third highest recorded discharge of the Green River downstream from Flaming Gorge Dam subsequent to its closure in 1963. Following this event, we made measurements of channel geometry, tracer gravel displacement, and sandbar sedimentology at four long-term monitoring reaches within the Canyon of Lodore in Dinosaur National Monument, Colorado. Here we integrate these data with nearly two decades of channel monitoring at these sites, encompassing five controlled floods, and providing a coarse resolution, but coherent, picture of channel response and changes in fine sediment storage in a canyon-bound river. We discuss these results in the context of long-term monitoring of controlled flood response along the Colorado River in Marble and Grand Canyons, Arizona. In Canyon of Lodore, moderate, short-duration controlled floods have had little effect on channel morphology or fine sediment storage. Alternatively, higher magnitude floods approaching the pre-dam mean annual flood, such as in 1999 and 2011, tended to be long duration and scoured fine sediment from the channel bed, in some places up to 5 m, while building eddy sandbars to within a meter of flood stage. This resulted in a net export of sediment from the monitored reaches. Between floods, eddy sand bars erode and the pools fill with fine sediment. We have observed only minor erosion or reworking of gravel bars and channel margin deposits stabilized by vegetation encroachment. The Green River in Canyon of Lodore is a scaled-down version of the Colorado River in debris fan-affected Marble and Grand Canyons. Both rivers now exist in varying degrees of sediment deficit due to upstream reservoirs. Coarse sediment from debris fans and hillslopes limits vertical incision and channel migration, focusing the post-dam geomorphic response to sediment imbalance on fine sediment located in eddy sandbars, pools, and channel margin deposits. In

  8. When and how long to flood for insect control

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Early-season flooding for insect pest control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Wisconsin, there is much interest in the spring flood as a means to not only reduce pest populations, but also to facilitate marsh sanitation and provide frost protection. A large-scale field study was undertaken in 2011 to examine how a 30-40 hour spring flood (late May) would affect key insect ...

  10. Shades of Green: Flood control study focused on Duluth, Minnesota

    EPA Science Inventory

    In the aftermath of the economically and environmentally painful flood of 2012, the city of Duluth and the CSC examined ecologically based options to reduce runoff velocities and flood volume in the watershed with assistance and input of Minnesota Duluth's Natural Resources Resea...

  11. Carbonate petroleum reservoirs

    SciTech Connect

    Roehl, P.O.; Choquette, P.W.

    1985-01-01

    This book presents papers on the geology of petroleum deposits. Topics considered include diagenesis, porosity, dolomite reservoirs, deposition, reservoir rock, reefs, morphology, fracture-controlled production, Cenozoic reservoirs, Mesozoic reservoirs, and Paleozoic reservoirs.

  12. Plant communities in relation to flooding and soil characteristics in the water level fluctuation zone of the Three Gorges Reservoir, China.

    PubMed

    Ye, Chen; Zhang, Kerong; Deng, Qi; Zhang, Quanfa

    2013-03-01

    With the filling of the Three Gorges Reservoir, original vegetation in the water level fluctuation zone (WLFZ) between the elevations of 145 and 175 m disappeared due to the reversal of submergence time (winter flooding) and prolonged inundation duration (nearly half a year). To better understand the relationships between the environmental factors and recovered plant communities for reconstructing floristically diverse riparian zone, we conducted a field survey in 11 sites in the WLFZ in June 2010, and vegetation composition, flooding characteristics, heavy metals, and soil major nutrients were determined. Consequently, the canonical correspondence analysis was used to investigate the relationships between plant species composition and flooding characteristics, heavy metal contamination, and soil nutrients. Results demonstrated that vegetation in the WLFZ was dominated by annuals, i.e., Echinochloa crusgalli and Bidens tripartita, and perennials including Cynodon dactylon, and plant species richness and diversity were negatively associated with flooding duration, heavy metal contamination, and nutrients including total phosphorus, available phosphorus, available potassium, and nitrate. Our results suggest that plant species, recovering mainly through soil seed bank and regeneration of remnant individuals, have been influenced by the combined effects of environmental factors. PMID:22968672

  13. 76 FR 39091 - San Luis Obispo Flood Control and Water Conservation District; Notice of Effectiveness of Surrender

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-05

    ... Energy Regulatory Commission San Luis Obispo Flood Control and Water Conservation District; Notice of... for a Conduit Hydroelectric Project \\1\\ to the San Luis Obispo Flood Control and Water Conservation...\\ San Luis Obispo Flood Control and Water Conservation District, 17 FERC ] 62,113 (1981). On October...

  14. CASE STUDY OF MULTI-YEAR PRECIPITATION VARIATIONS AND THE HYDROLOGY OF FORT COBB RESERVOIR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Impacts of decadal precipitation variations on reservoir inflow, flood releases, and pool elevation were investigated for the Fort Cobb Reservoir, a reservoir that controls runoff from an 800 km2 agricultural watershed in central Oklahoma. Difference in mean annual precipitation between multi-year d...

  15. 33 CFR 208.22 - Twin Buttes Dam and Reservoir, Middle and South Concho Rivers, Tex.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Twin Buttes Dam and Reservoir... and Reservoir, Middle and South Concho Rivers, Tex. The Bureau of Reclamation, or its designated agent, shall operate the Twin Buttes Dam and Reservoir in the interest of flood control as follows:...

  16. 33 CFR 208.25 - Pensacola Dam and Reservoir, Grand (Neosho) River, Okla.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pensacola Dam and Reservoir..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.25 Pensacola Dam and Reservoir... Dam, referred to in this section as the Representative shall operate the dam and reservoir in...

  17. Applications of ASFCM(Assessment System of Flood Control Measurement) in Typhoon Committee Members

    NASA Astrophysics Data System (ADS)

    Kim, C.

    2013-12-01

    Due to extreme weather environment such as global warming and greenhouse effect, the risks of having flood damage has been increased with larger scale of flood damages. Therefore, it became necessary to consider modifying climate change, flood damage and its scale to the previous dimension measurement evaluation system. In this regard, it is needed to establish a comprehensive and integrated system to evaluate the most optimized measures for flood control through eliminating uncertainties of socio-economic impacts. Assessment System of Structural Flood Control Measures (ASFCM) was developed for determining investment priorities of the flood control measures and establishing the social infrastructure projects. ASFCM consists of three modules: 1) the initial setup and inputs module, 2) the flood and damage estimation module, and 3) the socio-economic analysis module. First, we have to construct the D/B for flood damage estimation, which is the initial and input data about the estimation unit, property, historical flood damages, and applied area's topographic & hydrological data. After that, it is important to classify local characteristic for constructing flood damage data. Five local characteristics (big city, medium size city, small city, farming area, and mountain area) are classified by criterion of application (population density). Next step is the floodplain simulation with HEC-RAS which is selected to simulate inundation. Through inputting the D/B and damage estimation, it is able to estimate the total damage (only direct damage) that is the amount of cost to recover the socio-economic activities back to the safe level before flood did occur. The last module suggests the economic analysis index (B/C ratio) with Multidimensional Flood Damage Analysis. Consequently, ASFCM suggests the reference index in constructing flood control measures and planning non-structural systems to reduce water-related damage. It is possible to encourage flood control planners and

  18. Diversity and Above-Ground Biomass Patterns of Vascular Flora Induced by Flooding in the Drawdown Area of China's Three Gorges Reservoir

    PubMed Central

    Wang, Qiang; Yuan, Xingzhong; Willison, J.H.Martin; Zhang, Yuewei; Liu, Hong

    2014-01-01

    Hydrological alternation can dramatically influence riparian environments and shape riparian vegetation zonation. However, it was difficult to predict the status in the drawdown area of the Three Gorges Reservoir (TGR), because the hydrological regime created by the dam involves both short periods of summer flooding and long-term winter impoundment for half a year. In order to examine the effects of hydrological alternation on plant diversity and biomass in the drawdown area of TGR, twelve sites distributed along the length of the drawdown area of TGR were chosen to explore the lateral pattern of plant diversity and above-ground biomass at the ends of growing seasons in 2009 and 2010. We recorded 175 vascular plant species in 2009 and 127 in 2010, indicating that a significant loss of vascular flora in the drawdown area of TGR resulted from the new hydrological regimes. Cynodon dactylon and Cyperus rotundus had high tolerance to short periods of summer flooding and long-term winter flooding. Almost half of the remnant species were annuals. Species richness, Shannon-Wiener Index and above-ground biomass of vegetation exhibited an increasing pattern along the elevation gradient, being greater at higher elevations subjected to lower submergence stress. Plant diversity, above-ground biomass and species distribution were significantly influenced by the duration of submergence relative to elevation in both summer and previous winter. Several million tonnes of vegetation would be accumulated on the drawdown area of TGR in every summer and some adverse environmental problems may be introduced when it was submerged in winter. We conclude that vascular flora biodiversity in the drawdown area of TGR has dramatically declined after the impoundment to full capacity. The new hydrological condition, characterized by long-term winter flooding and short periods of summer flooding, determined vegetation biodiversity and above-ground biomass patterns along the elevation gradient in

  19. Polymer flooding

    SciTech Connect

    Littmann, W.

    1988-01-01

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

  20. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas: Reply

    SciTech Connect

    Kerans, C. )

    1990-07-01

    A reply to a comment made on Kerans' paper (AAGP Bull. 1988) by S.J. Mazzullo is presented. The author takes exception that Mazzullo's contention that he left out important types of hydrocarbon reservoirs in the Permian basin of west Texas and points out that his original intention was to model karst-controlled reservoir rocks only.

  1. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Final report

    SciTech Connect

    Pitts, M.

    1995-12-01

    This research studied the oil recovery potential of flooding light oil reservoirs by combining interfacial tension reducing agent(s) with a mobility control agent. The specific objectives were: To define the mechanisms and limitations of co-injecting interfacial tension reduction agent(s) and a mobility control agent to recover incremental oil. Specifically, the study focused on the fluid-fluid and fluid-rock interactions. To evaluate the economics of the combination technology and investigate methods to make the process more profitable. Specific areas of study were to evaluate different chemical concentration tapers and the volume of chemical injection required to give optimal oil recovery.

  2. Communal peeing: a new mode of flood control in ants

    NASA Astrophysics Data System (ADS)

    Maschwitz, Ulrich; Moog, J.

    The behavioral response of the obligate bamboo-nesting ant Cataulacus muticus to nest flooding was studied in a perhumid tropical rainforest in Malaysia and in the laboratory. The hollow internodes of giant bamboo, in which C. muticus exclusively nests, are prone to flooding by heavy rains. The ants showed a two-graded response to flooding. During heavy rain workers block the nest entrances with their heads to reduce water influx. However, rainwater may still intrude into the nest chamber. The ants respond by drinking the water, leaving the nest and excreting water droplets on the outer stem surface. This cooperative 'peeing' behavior is a new survival mechanism adaptive to the ants' nesting ecology. Laboratory experiments conducted with two other Cataulacus species, C. catuvolcus colonizing small dead twigs and C. horridus inhabiting rotten wood, did not reveal any form of water-bailing behavior.

  3. Probable maximum flood control; Yucca Mountain Site Characterization Project

    SciTech Connect

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility.

  4. Design and implementation of a CO{sub 2} flood utilizing advanced reservoir characterization and horizontal injection wells in a shallow shelf carbonate approaching waterflood depletion. Annual Report, July 1, 1995--June 30, 1996

    SciTech Connect

    Chimahusky, J.S.; Hallenbeck, L.D.; Harpole, K.J.; Dollens, K.B.

    1997-05-01

    The work reported herein covers select tasks remaining in Budget Phase I and many of the tasks of Budget Phase II. The principal Tasks in Budget Phase I included in this report are Reservoir Analysis and Characterization; Advanced Technical Studies; and Technology Transfer, Reporting and Project Management Activities for Budget Phase I. The principle Task in Budget Phase II included in this report is Field Demonstration. Completion of these tasks has enabled an optimum carbon dioxide (CO{sub 2}) flood project to be designed, economically evaluated, and implemented in the field. Field implementation of the project commenced during late 1995, with actual CO{sub 2} injection scheduled for start-up in mid-July, 1996. The current project has focused on reducing initial investment cost by utilizing horizontal injection wells and concentrating the project in the best productivity area of the field. An innovative CO{sub 2} purchase agreement (no take-or-pay provisions, CO{sub 2} purchase price tied to West Texas Intermediate (WTI) crude oil price) and gas recycle agreements (expensing costs as opposed to a large upfront capital investment for compression) were negotiated to further improve the project economics. The Grayburg-San Andres section had previously been divided into multiple zones based on the core study and gamma ray markers that correlate wells within the Unit. Each zone was mapped as continuous across the field. Previous core studies concluded that the reservoir quality in the South Cowden Unit (SCU) is controlled primarily by the distribution of a bioturbated and diagenetically-altered rock type with a distinctive {open_quotes}chaotic{close_quotes} texture. The {open_quotes}chaotic{close_quotes} modifier is derived from the visual effect of pervasive, small-scale intermixing of tan oil-stained reservoir rock with tight gray non-reservoir rock.

  5. IMPROVED MISCIBLE NITROGEN FLOOD PERFORMANCE UTILIZING ADVANCED RESERVOIR CHARACTERIZATION AND HORIZONTAL LATERALS IN A CLASS I RESERVOIR - EAST BINGER (MARCHAND) UNIT

    SciTech Connect

    Joe Sinner

    2002-03-26

    The objective of this project is two-fold. It will demonstrate use of nitrogen as a widely available, cost-effective and environmentally superior injectant for miscible floods. It will also demonstrate the effectiveness of horizontal wellbores in reducing gas breakthrough and cycling. It is expected that the demonstration will lead to implementation of nitrogen injection projects in areas without readily available carbon dioxide sources. Technology transfer will occur throughout the project.

  6. Post waterflood CO{sub 2} miscible flood in light oil, fluvial dominated deltaic reservoir. Third quarterly technical progress report, September 15, 1992--June 30, 1993

    SciTech Connect

    Not Available

    1993-07-15

    Texaco`s objective on this project has been to utilize all available technologies, and to develop new ones, to design a CO{sub 2} flood process which is cost effective and can be applied to many other reservoirs throughout the United States. This project will determine the recovery efficiency of CO{sub 2} floods in waterflooded and partial waterdrive reservoirs. A PC-based CO{sub 2} screening model will be developed and a database will be generated to show the utility of this technology throughout the US. After Pre-award costs were approved on September 15, 1992, Texaco proceeded with the implementation phase of the project so that new data could be gathered and necessary steps required to initiate CO{sub 2} injection could be accomplished. An expenditure of $7,080,191 has put Texaco in a position where CO{sub 2} injection can begin by September 1, 1993. The following tasks have been accomplished: (1) 10 workovers (4 injection, 6 producers) are complete. Production has increased from 78 BOPD to 183 BOPD. (2) Reservoir pressure has been increased from 1850 psi-to 2700 psi by injecting saltwater. (3) Compressors, a CO{sub 2} injection pump, and separators have been installed on a floating barge, and is being transported to the field by a tug boat. (4) 3 miles of the 4.5 mile CO{sub 2} pipeline has been installed. (5) A residual oil saturation of 30% to 35% has been measured from a new conventional core. A set of relative permeability curves have been developed.

  7. Dominant geomorphic controls on channel capacity and flood risk in a hydrologically variable fluvial system

    NASA Astrophysics Data System (ADS)

    Daley, James; Croke, Jacky; Thompson, Chris; Cohen, Tim

    2016-04-01

    Traditionally, particular emphasis has been placed on the hydrological characteristics of rivers to understand the role of channel morphology in flood risk. However, in regions of high hydrological variability, the relationship between channel characteristics and flood conveyance is often highly complex. Consequently in these settings, the applicability of stream discharge or steady-state form-process relationships, may be of less use to understanding flood conveyance. In the subtropical region of southeast Queensland, Australia, rivers are characterized by highly variable flows and entrenched channel morphologies. The latter are such dramatic features, they are termed 'macrochannels'. Following the extreme flood of 2011 in the Lockyer Creek in this region, longitudinal variations in the macrochannel form were found to be a significant factor in flood conveyance. Nine reaches were identified on a basis of flood inundation extent, with significant non-linear changes in channel capacity and discharge, alternating between flood expansion and contraction zones with associated increases and decreases in flood risk. Detailed geomorphic and chronostratigraphic analyses presented here indicate that macrochannel capacity is being strongly influenced by the antecedent bedrock topography, resistant valley-fill and abrupt downstream changes in sediment delivery. A large proportion of the valley fill represents a major Late Pleistocene aggradation phase of fine-grained alluvium that overlies older Pleistocene basal sediments. Subsequent channel incision at 10 ka reoccupied a pre-existing bedrock valley and resistant Pleistocene alluvium imposed substantial controls on the capacity for lateral adjustment. Abrupt changes in sediment supply associated with the location of tributaries provide further evidence for geomorphic controls on macrochannel form and capacity. Identification of the dominant geomorphic factors influencing the overall macrochannel form highlights the relative

  8. Estimation of phosphorus flux in rivers during flooding.

    PubMed

    Chen, Yen-Chang; Liu, Jih-Hung; Kuo, Jan-Tai; Lin, Cheng-Fang

    2013-07-01

    Reservoirs in Taiwan are inundated with nutrients that result in algal growth, and thus also reservoir eutrophication. Controlling the phosphorus load has always been the most crucial issue for maintaining reservoir water quality. Numerous agricultural activities, especially the production of tea in riparian areas, are conducted in watersheds in Taiwan. Nutrients from such activities, including phosphorus, are typically flushed into rivers during flooding, when over 90% of the yearly total amount of phosphorous enters reservoirs. Excessive or enhanced soil erosion from rainstorms can dramatically increase the river sediment load and the amount of particulate phosphorus flushed into rivers. When flow rates are high, particulate phosphorus is the dominant form of phosphorus, but sediment and discharge measurements are difficult during flooding, which makes estimating phosphorus flux in rivers difficult. This study determines total amounts of phosphorus transport by measuring flood discharge and phosphorous levels during flooding. Changes in particulate phosphorus, dissolved phosphorus, and their adsorption behavior during a 24-h period are analyzed owing to the fact that the time for particulate phosphorus adsorption and desorption approaching equilibrium is about 16 h. Erosion of the reservoir watershed was caused by adsorption and desorption of suspended solids in the river, a process which can be summarily described using the Lagmuir isotherm. A method for estimating the phosphorus flux in the Daiyujay Creek during Typhoon Bilis in 2006 is presented in this study. Both sediment and phosphorus are affected by the drastic discharge during flooding. Water quality data were collected during two flood events, flood in June 9, 2006 and Typhoon Bilis, to show the concentrations of suspended solids and total phosphorus during floods are much higher than normal stages. Therefore, the drastic changes of total phosphorus, particulate phosphorus, and dissolved phosphorus in

  9. Post waterflood CO{sub 2} miscible flood in light oil, fluvial-dominated deltaic reservoir. Annual report, fiscal year 1996

    SciTech Connect

    1996-08-15

    The Port Neches CO{sub 2} flood has been operating for nearly 4 years. The project performance during the past year has been adversely affected by several factors including: water blockage, low residual oil saturation and wellbore mechanical problems. The company attempted to test a new procedure in a new fault block using CO{sub 2} to accelerate primary production in order to improve the primary reserves net present value. The test was abandoned when the discovery well Polk B-39 for the Marg Area 3 was a dry hole. Also, during this period the company terminated all new CO{sub 2} purchases from Cardox for economical reasons, while continuing to recycle produced CO{sub 2}. A data base for FDD reservoirs for the Louisiana and Texas Gulf Coast Region was developed by LSU and SAIC. This data base includes reservoir parameters and performance data for reservoirs with significant production and OOIP volumes that are amenable to CO{sub 2} injection. A paper discussing the Port Neches CO{sub 2} project was presented at the 1996 SPE/DOE Symposium on Improved Oil Recovery.

  10. Core flooding tests to investigate the effects of IFT reduction and wettability alteration on oil recovery during MEOR process in an Iranian oil reservoir.

    PubMed

    Rabiei, Arash; Sharifinik, Milad; Niazi, Ali; Hashemi, Abdolnabi; Ayatollahi, Shahab

    2013-07-01

    Microbial enhanced oil recovery (MEOR) refers to the process of using bacterial activities for more oil recovery from oil reservoirs mainly by interfacial tension reduction and wettability alteration mechanisms. Investigating the impact of these two mechanisms on enhanced oil recovery during MEOR process is the main objective of this work. Different analytical methods such as oil spreading and surface activity measurements were utilized to screen the biosurfactant-producing bacteria isolated from the brine of a specific oil reservoir located in the southwest of Iran. The isolates identified by 16S rDNA and biochemical analysis as Enterobacter cloacae (Persian Type Culture Collection (PTCC) 1798) and Enterobacter hormaechei (PTCC 1799) produce 1.53 g/l of biosurfactant. The produced biosurfactant caused substantial surface tension reduction of the growth medium and interfacial tension reduction between oil and brine to 31 and 3.2 mN/m from the original value of 72 and 29 mN/m, respectively. A novel set of core flooding tests, including in situ and ex situ scenarios, was designed to explore the potential of the isolated consortium as an agent for MEOR process. Besides, the individual effects of wettability alteration and IFT reduction on oil recovery efficiency by this process were investigated. The results show that the wettability alteration of the reservoir rock toward neutrally wet condition in the course of the adsorption of bacteria cells and biofilm formation are the dominant mechanisms on the improvement of oil recovery efficiency. PMID:23553033

  11. Study and pilot test on a novel EOR method -- coupling PPG conformance control and surfactant flooding

    NASA Astrophysics Data System (ADS)

    Muhammed, Farag Awadh

    The interest in enhanced oil recovery (EOR) methods has re-emerged in recent years; however, significant challenges remain for the widespread deployment of these methods. One major downside to the successful application of EOR technologies in mature reservoirs is conformance problems (e.g. heterogeneity). To mitigate these problems, a novel EOR method which couple preformed particle gel (PPGs) conformance treatment with traditional surfactant flooding in one process is introduced. This dissertation provides a comprehensive study for the proposed method. A series of laboratory tests were carried out to understand the chemical interaction between PPGs and surfactants. A new method to evaluate PPGs strength in the oilfield and laboratory was introduced. Core flooding tests were run to investigate to what extent the coupled method can improve oil recovery using fractured carbonate and sandstone cores. Oilfield pilot tests were implemented in several injection wells located in Kansas. The chemical interaction experiments showed that surfactants concentrations influenced the swelling ratio and strength of PPGs. Fractured core flooding tests showed a higher increase in oil recovery through surfactant forced imbibition process by PPGs than a single method. The new PPG strength measurement apparatus provided a reliable technique to quantitatively evaluate PPG properties in the field. Oilfield pilot tests were implemented successfully in several candidate wells. The treatment s effectively increased the injection pressure of injection wells and reduced water production of adjacent production wells. Overall, this method provides a cost-effective approach for improving oil recovery while also reducing excess water production in mature and fractured reservoirs.

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

    PubMed

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

    2014-01-01

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

  13. DESIGN AND IMPLEMENTATION OF A CO2 FLOOD UTILIZING ADVANCED RESERVOIR CHARACTERIZATION AND HORIZONTAL INJECTION WELLS IN A SHALLOW SHELF CARBONATE APPROACHING WATERFLOOD DEPLETION

    SciTech Connect

    K.J. Harpole; Ed G. Durrett; Susan Snow; J.S. Bles; Carlon Robertson; C.D. Caldwell; D.J. Harms; R.L. King; B.A. Baldwin; D. Wegener; M. Navarrette

    2002-09-01

    The purpose of this project was to economically design an optimum carbon dioxide (CO{sub 2}) flood for a mature waterflood nearing its economic abandonment. The original project utilized advanced reservoir characterization and CO{sub 2} horizontal injection wells as the primary methods to redevelop the South Cowden Unit (SCU). The development plans; project implementation and reservoir management techniques were to be transferred to the public domain to assist in preventing premature abandonment of similar fields. The Unit was a mature waterflood with water cut exceeding 95%. Oil must be mobilized through the use of a miscible or near-miscible fluid to recover significant additional reserves. Also, because the unit was relatively small, it did not have the benefit of economies of scale inherent in normal larger scale projects. Thus, new and innovative methods were required to reduce investment and operating costs. Two primary methods used to accomplish improved economics were use of reservoir characterization to restrict the flood to the higher quality rock in the unit and use of horizontal injection wells to cut investment and operating costs. The project consisted of two budget phases. Budget Phase I started in June 1994 and ended late June 1996. In this phase Reservoir Analysis, Characterization Tasks and Advanced Technology Definition Tasks were completed. Completion enabled the project to be designed, evaluated, and an Authority for Expenditure (AFE) for project implementation submitted to working interest owners for approval. Budget Phase II consisted of the implementation and execution of the project in the field. Phase II was completed in July 2001. Performance monitoring, during Phase II, by mid 1998 identified the majority of producing wells which under performed their anticipated withdrawal rates. Newly drilled and re-activated wells had lower offtake rates than originally forecasted. As a result of poor offtake, higher reservoir pressure was a concern

  14. Abiotic & biotic responses of the Colorado River to controlled floods at Glen Canyon Dam, Arizona, USA

    USGS Publications Warehouse

    Korman, Josh; Melis, Ted; Kennedy, Theodore A.

    2012-01-01

    Closure of Glen Canyon Dam reduced sand supply to the Colorado River in Grand Canyon National Park by about 94% while its operation has also eroded the park's sandbar habitats. Three controlled floods released from the dam since 1995 suggest that sandbars might be rebuilt and maintained, but only if repeated floods are timed to follow tributary sand deliveries below the dam. Monitoring data show that sandbars are dynamic and that their erosion after bar building is positively related with mean daily discharge and negatively related with tributary sand production after controlled floods. The March 2008 flood affected non-native rainbow trout abundance in the Lees Ferry tailwater, which supports a blue ribbon fishery. Downstream trout dispersal from the tailwater results in negative competitive interactions and predation on endangered humpback chub. Early survival rates of age-0 trout increased more than fourfold following the 2008 flood, and twofold in 2009, relative to prior years (2006-2007). Hatch-date analysis indicated that early survival rates were much higher for cohorts that emerged about 2 months after the 2008 flood relative to cohorts that emerged earlier that year. The 2009 survival data suggest that tailwater habitat improvements persisted for at least a year, but apparently decreased in 2010. Increased early survival rates for trout coincided with the increased availability of higher quality drifting food items after the 2008 flood owing to an increase in midges and black flies, preferred food items of rainbow trout. Repeated floods from the dam might sustainably rebuild and maintain sandbars if released when new tributary sand is available below the tailwater. Spring flooding might also sustain increased trout abundance and benefit the tailwater fishery, but also be a potential risk to humpback chub in Grand Canyon.

  15. Torrent floodplain mapping and torrent flood control in Serbia in the conditions of economic crisis

    NASA Astrophysics Data System (ADS)

    Gavrilovic, Z.; Stefanovic, M.

    2009-04-01

    investments. This paper will present the realised results of low-budget mapping of flood zones of torrents and other waterways and the realised preventive techniques of torrential flood control, which were successfully implemented during the great flood of the Danube in 2006. On that occasion, numerous torrential floods endangered the defence system of the river Danube. Key words: Floodplain, flood, torrent, flood defence.

  16. 33 CFR 208.22 - Twin Buttes Dam and Reservoir, Middle and South Concho Rivers, Tex.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Whenever the Twin Buttes Reservoir level is between elevations 1,940.2 (top of conservation pool) and elevation 1,969.1 (top of flood control pool) the flood control discharge facilities shall be operated under... Angelo, Tex. (river mile 60.9); or a 22.8-foot stage (25,000 c.f.s.) on the USGS gage near Paint...

  17. 33 CFR 208.22 - Twin Buttes Dam and Reservoir, Middle and South Concho Rivers, Tex.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Whenever the Twin Buttes Reservoir level is between elevations 1,940.2 (top of conservation pool) and elevation 1,969.1 (top of flood control pool) the flood control discharge facilities shall be operated under... Angelo, Tex. (river mile 60.9); or a 22.8-foot stage (25,000 c.f.s.) on the USGS gage near Paint...

  18. Backwaters in the upper reaches of reservoirs produce high densities of age-0 crappies

    USGS Publications Warehouse

    Dagel, Jonah D.; Miranda, Leandro E.

    2012-01-01

    Reservoir backwaters are aquatic habitats in floodplains of reservoir tributaries that are permanently or periodically flooded by the reservoir. Like many reservoir arms, backwaters are commonly shallow, littoral habitats, but they differ from arms in various respects, including their support of primarily wetland plant assemblages that are tolerant to flooding. Elsewhere, the reservoir floods mainly upland plants that are less tolerant to flooding, producing a band of barren shoreline along the fluctuation zone. We investigated differences in relative abundance of age-0 crappies Pomoxis spp. in backwaters and arms of widely fluctuating flood control reservoirs, examined the effect of water level, and estimated the likelihood and timing with which these habitats are flooded annually. Higher catch rates of age-0 crappies were obtained in backwater habitats than in arm habitats. When inundated during the crappie spawning season, backwaters provided vegetated habitat at lower water levels than arms. Backwaters flooded earlier than arms and remained flooded longer to provide prolonged nursery habitat. Whereas vegetated habitat was inundated almost yearly in backwaters and arms, inundation that was timed to the onset of spawning occurred less regularly. Because of differences in water elevation, vegetated habitats were flooded in time for crappie spawning about every other year in backwaters but only every third year in arms. Recruitment of age-0 crappies was inversely correlated with high water levels during the months preceding the spawning period, perhaps because early flooding degraded the vegetation. Our results suggest that water levels may be managed during late winter and spring to regularly flood wetland vegetation communities in backwaters; however, water levels should be maintained at or below normal pool and should only irregularly flood upland vegetation in reservoir arms to promote the preservation of such vegetation. Furthermore, management efforts to

  19. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect

    Seright, Randall; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Anand; Wavrik, Kathryn

    2001-09-07

    The objectives of this project are: (1) to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas, (2) to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems, and (3) to develop procedures to optimize blocking agent placement in naturally fractured reservoirs. Work was directed at both injection wells and production wells and at vertical, horizontal, and highly deviated wells.

  20. Sequence stratigraphic control on prolific HC reservoir development, Southwest Iran

    USGS Publications Warehouse

    Lasemi, Y.; Kondroud, K.N.

    2008-01-01

    An important carbonate formation in the Persian Gulf and the onshore oil fields of Southwest Iran is the Lowermost Cretaceous Fahliyan formation. The formation in Darkhowain field consists of unconformity-bounded depositional sequences containing prolific hydrocarbon reservoirs of contrasting origin. Located in the high stand systems tract (HST) of the lower sequence encompassing over 200m of oil column are the most prolific reservoir. Another reservoir is over 80m thick consisting of shallowing-upward cycles that are best developed within the transgressive systems tract of the upper sequence. Vertical facies distribution and their paleobathymetry and geophysical log signatures of the Fahliyan formation in the Darkhowain platform reveal the presence of two unconformity-bounded depositional sequences in Vail et al., Van Wagoner et al., and Sarg. The Fahliyan formation mainly consists of platform carbonates composed of restricted bioclastic lime mudstone to packstone of the platform interior, Lithocodium boundstone or ooid-intraclast-bioclast grainstone of the high energy platform margin and the bioclast packstone to lime mudstone related to the off-platform setting.

  1. High-Performance Integrated Control of water quality and quantity in urban water reservoirs by dynamic emulation and model predictive control

    NASA Astrophysics Data System (ADS)

    Castelletti, A.; Galelli, S.; Goedbloed, A.

    2015-12-01

    Retention basins and urban reservoirs are increasingly used to support drinking water supply in large metropolitan contexts, since they make use of a resource, i.e., stormwater, that would be otherwise wasted, thus limiting the amount of water extracted from natural systems or produced with energy-intensive techniques. Yet, the operation of these infrastructures faces a twofold challenge. First, the presence of large impervious areas in urban catchments results in high discharge peaks and runoff volumes and a fast runoff response to rainfall, with consequent very short times of concentration. Second, stormwater transports large amount of pollutants to the receiving water bodies. This paper contributes a novel High-Performance Integrated Control framework to support the real-time operation of urban water supply storages affected by water quality problems. We use a 3D hydrodynamic, high-fidelity, simulation model to predict the main water quality dynamics and inform a real-time controller based on Model Predictive Control. We integrate the simulation model into the control scheme by a model reduction process, where the high-fidelity simulator is first used to identify and then replaced by a low-order dynamic emulator, which runs orders of magnitude faster. The framework is used to design the hourly operation of Marina Reservoir, a 3.2 Mm3 stormwater-fed reservoir located in the centre of Singapore operated for drinking water supply and flood control. Because of its recent formation from a former estuary, the reservoir suffers from high salinity levels, whose dynamics is modelled with Delft3D-FLOW. Results show that the real-time operation designed by our framework drops the minimum salinity levels of nearly 30% while reducing the average annual deficit of drinking water supply by about two times the active storage of the reservoir. Such a win-win solution is obtained by means of a model reduction process that reduced the dimensionality of Delft3D-FLOW by three orders

  2. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect

    Seright, Randal S.

    2000-04-19

    This research project has three objectives. The first objective is to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective is to develop procedures for optimizing blocking-agent placement in wells where hydraulic fractures cause channeling. The third objective is to develop procedures to optimize blocking-agent placement in naturally fractured reservoirs. This research project consists of three tasks, each of which addresses one of the above objectives. Work is directed at both injection wells and production wells and at vertical, horizontal, and highly deviated wells.

  3. Using Chemicals to Optimize Conformance Control in Fractured Reservoirs

    SciTech Connect

    Seright, Randall S.

    2000-09-20

    This research project has three objectives. The first objective is to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective is to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective is to develop procedures to optimize blocking agent placement in naturally fractured reservoirs. This research project consists of three tasks, each of which addresses one of the above objectives. This work is directed at both injection wells and production wells and at vertical, horizontal, and highly deviated wells.

  4. Improved Miscible Nitrogen Flood Performance Utilizing Advanced Reservoir Characterization and Horizontal Laterals in a Class I Reservoir--East Binger (Marchand) Unit

    SciTech Connect

    Joe Sinner

    2006-05-18

    A significant work program was implemented from 2002 to 2005 in the East Binger Unit (''EBU'') miscible nitrogen injection project in an effort to reduce gas cycling and economically increase ultimate oil recovery. This work included the drilling of new wells, both horizontal and vertical, as well as pattern realignment through producer-to-injector conversions. Monitoring of overall performance of the pilot area continues. Response to the various projects continues to be very favorable. Injection into the pilot area, despite being limited at times by problems in the Air Separation Unit of the Nitrogen Management Facility, has increased an average of 60% over levels prior to the project. Meanwhile, gas production and nitrogen content of produced gas have both decreased. After decreasing to 20-25% early in the project, nitrogen recycle (produced nitrogen volume divided by injected nitrogen volume) within the pilot area has risen to about 40%, still far below the 72% prior to initiation of the project. Poor areal sweep efficiency appears to be the primary cause of nitrogen cycling. Seven vertical and three horizontal wells have been drilled in the pilot area throughout the project, and most have had initial produced gas oil ratios and gas nitrogen contents significantly below the field averages. Given similar reservoir conditions of net thickness and gas sweep, vertical wells are performing nearly as well as horizontal wells. Additional vertical well drilling was completed in 2005 following the success of wells drilled from 2002 through 2004.

  5. IMPROVED MISCIBLE NITROGEN FLOOD PERFORMANCE UTILIZING ADVANCED RESERVOIR CHARACTERIZATION AND HORIZONTAL LATERALS IN A CLASS I RESERVOIR - EAST BINGER (MARCHAND) UNIT

    SciTech Connect

    Joe Sinner

    2003-01-31

    Implementation of the work program of Budget Period 2 of the East Binger Unit (''EBU'') DOE Project continues. Major development work planned for the project includes the drilling of three horizontal production and one vertical injection wells, the conversion of five wells from production to injection service, and the expansion of injection capacity at the nitrogen management facility. Other work items include initiation of project monitoring and continued reservoir simulation. EBU 74G-2, the injection well planned to support the production of EBU 64-3H, has been drilled. Completion was underway at the time of this report. EBU 64-3H was fracture-stimulated during the period, further increasing production from this new horizontal well. Drilling of the final two wells of the pilot project is planned for 2003. Both are planned as horizontal producing wells. Work also began on projects aimed at increasing injection in the pilot area. The project to add compression and increase injection capacity at the nitrogen management facility was initiated, with completion targeted for March 2003. Additional producer-to-injector conversions are expected to be implemented around the same time. The revised history match of the simulation model has been completed, and work has begun to evaluate options with forecast simulations. The quality of the history match is significantly improved over the prior match. The predicted distribution of remaining reserves in the field is significantly changed. Decisions on projects planned for implementation later in Budget Period 2 will be guided by new forecasts.

  6. Understanding satellite-based monthly-to-seasonal reservoir outflow estimation as a function of hydrologic controls

    NASA Astrophysics Data System (ADS)

    Bonnema, Matthew; Sikder, Safat; Miao, Yabin; Chen, Xiaodong; Hossain, Faisal; Ara Pervin, Ismat; Mahbubur Rahman, S. M.; Lee, Hyongki

    2016-05-01

    Growing population and increased demand for water is causing an increase in dam and reservoir construction in developing nations. When rivers cross international boundaries, the downstream stakeholders often have little knowledge of upstream reservoir operation practices. Satellite remote sensing in the form of radar altimetry and multisensor precipitation products can be used as a practical way to provide downstream stakeholders with the fundamentally elusive upstream information on reservoir outflow needed to make important and proactive water management decisions. This study uses a mass balance approach of three hydrologic controls to estimate reservoir outflow from satellite data at monthly and annual time scales: precipitation-induced inflow, evaporation, and reservoir storage change. Furthermore, this study explores the importance of each of these hydrologic controls to the accuracy of outflow estimation. The hydrologic controls found to be unimportant could potentially be neglected from similar future studies. Two reservoirs were examined in contrasting regions of the world, the Hungry Horse Reservoir in a mountainous region in northwest U.S. and the Kaptai Reservoir in a low-lying, forested region of Bangladesh. It was found that this mass balance method estimated the annual outflow of both reservoirs with reasonable skill. The estimation of monthly outflow from both reservoirs was however less accurate. The Kaptai basin exhibited a shift in basin behavior resulting in variable accuracy across the 9 year study period. Monthly outflow estimation from Hungry Horse Reservoir was compounded by snow accumulation and melt processes, reflected by relatively low accuracy in summer and fall, when snow processes control runoff. Furthermore, it was found that the important hydrologic controls for reservoir outflow estimation at the monthly time scale differs between the two reservoirs, with precipitation-induced inflow being the most important control for the Kaptai

  7. An analytical framework for flood water conservation considering forecast uncertainty and acceptable risk

    NASA Astrophysics Data System (ADS)

    Ding, Wei; Zhang, Chi; Peng, Yong; Zeng, Ruijie; Zhou, Huicheng; Cai, Ximing

    2015-06-01

    This paper addresses how much flood water can be conserved for use after the flood season through the operation of reservoir by taking into account the residual flood control capacity (the difference between flood conveyance capacity and the expected inflow in a lead time). A two-stage model for dynamic control of the flood-limited water level (the maximum allowed water level during the flood season, DC-FLWL) is established considering forecast uncertainty and acceptable flood risk. It is found that DC-FLWL is applicable when the reservoir inflow ranges from small to medium levels of the historical records, while both forecast uncertainty and acceptable risk in the downstream affect the feasible space of DC-FLWL. As forecast uncertainty increases (under a given risk level) or as acceptable risk level decreases (under a given forecast uncertainty level), the minimum required safety margin for flood control increases, and the chance for DC-FLWL decreases. The derived hedging rules from the modeling framework illustrate either the dominant role of water conservation or flood control or the trade-off between the two objectives under different levels of forecast uncertainty and acceptable risk. These rules may provide useful guidelines for conserving water from flood, especially in the area with heavy water stress. The analysis is illustrated via a case study with a real-world reservoir in northeastern China.

  8. The geomorphic effectiveness of a large flood on the Rio Grande in the Big Bend region: Insights on geomorphic controls and post-flood geomorphic response

    NASA Astrophysics Data System (ADS)

    Dean, David J.; Schmidt, John C.

    2013-11-01

    Since the 1940s, the Rio Grande in the Big Bend region has undergone long periods of channel narrowing, which have been occasionally interrupted by rare, large floods that widen the channel (termed a channel reset). The most recent channel reset occurred in 2008 following a 17-year period of extremely low stream flow and rapid channel narrowing. Flooding was caused by precipitation associated with the remnants of tropical depression Lowell in the Rio Conchos watershed, the largest tributary to the Rio Grande. Floodwaters approached 1500 m3/s (between a 13 and 15 year recurrence interval) and breached levees, inundated communities, and flooded the alluvial valley of the Rio Grande; the wetted width exceeding 2.5 km in some locations. The 2008 flood had the 7th largest magnitude of record, however, conveyed the largest volume of water than any other flood. Because of the narrow pre-flood channel conditions, record flood stages occurred. We used pre- and post-flood aerial photographs, channel and floodplain surveys, and 1-dimensional hydraulic models to quantify the magnitude of channel change, investigate the controls of flood-induced geomorphic changes, and measure the post-flood response of the widened channel. These analyses show that geomorphic changes included channel widening, meander migration, avulsions, extensive bar formation, and vertical floodplain accretion. Reach-averaged channel widening between 26 and 52% occurred, but in some localities exceeded 500%. The degree and style of channel response was related, but not limited to, three factors: 1) bed-load supply and transport, 2) pre-flood channel plan form, and 3) rapid declines in specific stream power downstream of constrictions and areas of high channel bed slope. The post-flood channel response has consisted of channel contraction through the aggradation of the channel bed and the formation of fine-grained benches inset within the widened channel margins. The most significant post-flood geomorphic

  9. The geomorphic effectiveness of a large flood on the Rio Grande in the Big Bend region: insights on geomorphic controls and post-flood geomorphic response

    USGS Publications Warehouse

    Dean, David J.; Schmidt, John C.

    2013-01-01

    Since the 1940s, the Rio Grande in the Big Bend region has undergone long periods of channel narrowing, which have been occasionally interrupted by rare, large floods that widen the channel (termed a channel reset). The most recent channel reset occurred in 2008 following a 17-year period of extremely low stream flow and rapid channel narrowing. Flooding was caused by precipitation associated with the remnants of tropical depression Lowell in the Rio Conchos watershed, the largest tributary to the Rio Grande. Floodwaters approached 1500 m3/s (between a 13 and 15 year recurrence interval) and breached levees, inundated communities, and flooded the alluvial valley of the Rio Grande; the wetted width exceeding 2.5 km in some locations. The 2008 flood had the 7th largest magnitude of record, however, conveyed the largest volume of water than any other flood. Because of the narrow pre-flood channel conditions, record flood stages occurred. We used pre- and post-flood aerial photographs, channel and floodplain surveys, and 1-dimensional hydraulic models to quantify the magnitude of channel change, investigate the controls of flood-induced geomorphic changes, and measure the post-flood response of the widened channel. These analyses show that geomorphic changes included channel widening, meander migration, avulsions, extensive bar formation, and vertical floodplain accretion. Reach-averaged channel widening between 26 and 52% occurred, but in some localities exceeded 500%. The degree and style of channel response was related, but not limited to, three factors: 1) bed-load supply and transport, 2) pre-flood channel plan form, and 3) rapid declines in specific stream power downstream of constrictions and areas of high channel bed slope. The post-flood channel response has consisted of channel contraction through the aggradation of the channel bed and the formation of fine-grained benches inset within the widened channel margins. The most significant post-flood geomorphic

  10. Geological control on the reservoir characteristics of Olkaria West Geothermal Field, Kenya

    SciTech Connect

    Omenda, Peter A.

    1994-01-20

    The reservoir of the West Olkaria Geothermal Field is hosted within tuffs and the reservoir fluid is characterized by higher concentrations of reservoir CO{sub 2} (10,000-100,000 mg/kg) but lower chloride concentrations of about 200 mg/kg than the East and North East Fields. The West Field is in the outflow and main recharge area of the Olkaria geothermal system. Permeability is generally low in the West Field and its distribution is strongly controlled by the structures. Fault zones show higher permeability with wells drilled within the structures havin larger total mass outputs. However, N-S and NW-SE faults are mainly channels for cold water downflow into the reservoir. Well feeder zones occur mostly at lava-tuff contacts; within fractured lava flows and at the contacts of intrusives and host rocks.

  11. Summary and synthesis of geomorphic studies conducted during the 1996 controlled flood in Grand Canyon

    NASA Astrophysics Data System (ADS)

    Schmidt, John C.

    The 1996 controlled flood demonstrated that a discharge of 1274 m3/s was sufficient to form or rework alluvial deposits along the Colorado River in Grand Canyon. This flood was moderately large in relation to other floods that have occurred since Glen Canyon Dam was completed in 1963. The flood also provided the opportunity to make measurements of physical processes that occurred. The flood caused widespread deposition of sand to elevations 3-5 m above the stage of the administratively-determined minimum daytime dam release of 227 m3/s and caused an increase in the area and volume of the high-elevation parts of sand bars, thereby increasing the number of new campsites. The low-elevation parts of the same eddies were eroded, as were adjacent channel pools. Recently-aggraded debris fans were reworked. Suspended-sediment transport measurements showed that suspended-sand concentrations decreased with time and that transport rates are highest when the channel bed is relatively fine and has a higher proportion of sand. The controlled flood was most effective during the first 4 days when mainstem transport rates and eddy deposition rates were high; debris-fan reworking entirely occurred during the first 4 hrs at one site. Modeling studies strongly indicate that resultant eddy-bar topography depends greatly on the concentration of mainstem suspended sediment and the initial topography of eddies. Large-scale erosion occurred on different days at different sites and had the potential to evacuate large proportions of newly-deposited sand from eddies. The final flood-formed topography of eddy bars was thus highly variable from site to site and from reach to reach.

  12. Improvement of sweep efficiency and mobility control in gas flooding

    SciTech Connect

    Strycker, A.; Llave, F.M.

    1991-04-01

    The application of carbon dioxide or other gases to extract crude oil from depleted reservoirs has been shown to be a technically successful process. However, optimized recoveries are often compromised by poor sweep efficiencies because of low gas viscosities and densities. A new process was investigated that potentially could improve sweep efficiencies by enhancing extractability properties of the injected gas with entrainers. Use of a capillary viscometer to evaluate enhanced viscosities appeared to be the best procedure for evaluating candidate compounds. A mathematical treatment was proposed based on predicting entrainer solubilities and minimum miscibility pressure alterations for carbon dioxide. However, use of many assumptions and approximations limited the effectiveness of this approach to qualitative evaluations. Some 87 compounds were evaluated using this mathematical treatment, and certain monoaromatic compounds were identified for further laboratory testing. 33 refs., 8 figs., 3 tabs.

  13. POLLUTION PREVENTION OPPORTUNITY ASSESSMENT UNITED STATES ARMY CORPS OF ENGINEERS - JOHN H. KERR DAM AND RESERVOIR, BOYDTON, VIRGINIA

    EPA Science Inventory

    The report describes the results of pollution prevention opportunity assessments conducted at a representative U.S. Army Corps of Engineers civil works facilities including a flood control reservoir and associated public use areas. ecommended methods for reducing pollution result...

  14. 76 FR 19753 - Intent To Prepare a Draft Environmental Impact Statement for the `Īao Stream Flood Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-08

    ... ` ao Stream Flood Control Project, Wailuku, Maui, HI AGENCY: Department of the Army, U.S. Army Corps of... design deficiency in the existing ` ao Stream Flood Control Project, Wailuku, Maui, HI. This effort is..., Civil and Public Works Branch (CEPOH-PP-C), Building 230, Fort Shafter, HI 96858- 5440....

  15. HEAT AND MASS TRANSFER IN A FAULT-CONTROLLED GEOTHERMAL RESERVOIR CHARGED AT CONSTANT PRESSURE

    SciTech Connect

    Goyal, K. P.; Narasimhan, T. N.

    1981-12-01

    A two-dimensional mathematical model of a fault controlled geothermal reservoir has been developed. Heated lighter water, rising in the fault, is assumed to charge a reservoir which, in turn, is overlain by a thin impermeable, thermally conducting cap rock. The mass flow rate or the pressure associated with the charging process at the fault inlet is unknown and can only be estimated. Thus, in this paper, the pressure in the fault at the bottom of the reservoir is assumed to be prescribed. Quasi-analytic solutions for the velocity, pressure, and temperature are obtained in the fault-reservoir system for a high Rayleigh number flow. In this approximation, the upwelling fluid does not cool off appreciably until it reaches the cold upper boundary of the reservoir and encounters conductive heat loss. This thermal boundary layer, which is thin at the top of the fault, grows outward laterally and occupies the full thickness of the aquifer far away from the fault. The mathematical model is based on the flow of liquid water in a saturated porous medium. The solution techniques involve the combination of perturbation methods, boundary layer theory and numerical methods. The analysis of this generic model can be applied to liquid dominated geothermal systems where the thickness of the impermeable caprock is very small compared to the depth of the reservoir.

  16. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Quarterly technical progress report, April 1, 1996--June 30, 1996

    SciTech Connect

    Schechter, D.S.

    1996-07-20

    Progress has been made in each of the three project areas during this quarter. Each quarter we are highlighting one project area. This quarter, Task 2 is highlighted with expanded details. Significant progress has been made this quarter in testing the functionalities of the foam-durability apparatus for assessment of foam properties at reservoir conditions. Another surfactant, Alipal{reg_sign} CD-128 at a concentration of 1000 ppm, was used for core flooding experiments. The foam mobility data showed a significant reduction of CO{sub 2} mobility and a favorable mobility dependence on rock permeability. Two slim tube test series and continuous phase equilibrium were done to examine the effects of pressure, temperature, and oil composition on oil displacement efficiency. A new series of core foam tests were completed to study the effects of flow rate, CO{sub 2} fraction (foam) quality, and rock permeability on foam-flow behavior. We are in the process of moving the foam reservoir simulator MASTER from a workstation to a Pentium PC environment and test MASTER on a 166 MHz Pentium PC. IFT of CO{sub 2}/crude oil has been measured using our pendant drop measurement system at 138{degrees}F and pressures from 850 psig to 2200 psig. The CO{sub 2} gravity drainage experiment that is in progress using a 50md Berea core at 138{degrees}F and pressures from 1700 to 2000 psig has reached 48% oil recovery and is continuing to increase. The mathematical model developed previously matches the experimental response accurately.

  17. 33 CFR 203.43 - Inspection of Federal flood control works.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Inspection of Federal flood control works. 203.43 Section 203.43 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for...

  18. Floodplain restoration with flood control: fish habitat value of levee borrow pits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Earthen flood control levees are often built using soil excavated from borrow pits lying parallel to and riverward of the finished levee. After construction, these pits can provide valuable floodplain habitats, and their value is well established along corridors of larger rivers. However, levee bo...

  19. Birth of a megaproject: Political economy of flood control in bangladesh

    NASA Astrophysics Data System (ADS)

    Boyce, James K.

    1990-07-01

    A major flood control initiative has been launched in Bangladesh under the coordination of the World Bank. The bank's five-year Action Plan is intended to initiate a long-term investment program, the specifics of which remain to be determined. Long-term proposals under consideration include the construction of massive embankments along the great rivers of the Bangladesh delta. The wisdom of such a “structural solution” to Bangladesh's flood problems can be questioned on economic, environmental, and technical grounds. Regrettably, the decision-making process has not encouraged wide debate on these questions.

  20. Bristol Floods 1968. Controlled Survey of Effects on Health of Local Community Disaster

    PubMed Central

    Bennet, Glin

    1970-01-01

    An investigation into the health of people in Bristol flooded in July 1968 was made by means of a controlled survey and a study of mortality rates. There was a 50% increase in the number of deaths among those whose homes had been flooded, with a conspicuous rise in deaths from cancer. Surgery attendances rose by 53%, referrals to hospital and hospital admissions more than doubled. In all respects the men appeared less well able to cope with the experience of disaster than the women. PMID:5454327

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  3. Floods and Flash Flooding

    MedlinePlus

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

  4. 33 CFR 208.22 - Twin Buttes Dam and Reservoir, Middle and South Concho Rivers, Tex.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Twin Buttes Dam and Reservoir, Middle and South Concho Rivers, Tex. 208.22 Section 208.22 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.22 Twin Buttes Dam and Reservoir, Middle and South...

  5. 33 CFR 208.25 - Pensacola Dam and Reservoir, Grand (Neosho) River, Okla.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pensacola Dam and Reservoir, Grand (Neosho) River, Okla. 208.25 Section 208.25 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.25 Pensacola Dam and Reservoir, Grand (Neosho) River, Okla....

  6. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Altus Dam and Reservoir, North Fork Red River, Okla. 208.26 Section 208.26 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.26 Altus Dam and Reservoir, North Fork Red River, Okla. The Bureau...

  7. 33 CFR 208.22 - Twin Buttes Dam and Reservoir, Middle and South Concho Rivers, Tex.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Twin Buttes Dam and Reservoir, Middle and South Concho Rivers, Tex. 208.22 Section 208.22 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.22 Twin Buttes Dam and Reservoir, Middle and South...

  8. 33 CFR 208.33 - Cheney Dam and Reservoir, North Fork of Ninnescah River, Kans.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Cheney Dam and Reservoir, North Fork of Ninnescah River, Kans. 208.33 Section 208.33 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.33 Cheney Dam and Reservoir, North Fork of Ninnescah River,...

  9. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Altus Dam and Reservoir, North Fork Red River, Okla. 208.26 Section 208.26 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.26 Altus Dam and Reservoir, North Fork Red River, Okla. The Bureau...

  10. 33 CFR 208.25 - Pensacola Dam and Reservoir, Grand (Neosho) River, Okla.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pensacola Dam and Reservoir, Grand (Neosho) River, Okla. 208.25 Section 208.25 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.25 Pensacola Dam and Reservoir, Grand (Neosho) River, Okla....

  11. 33 CFR 208.33 - Cheney Dam and Reservoir, North Fork of Ninnescah River, Kans.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Cheney Dam and Reservoir, North Fork of Ninnescah River, Kans. 208.33 Section 208.33 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.33 Cheney Dam and Reservoir, North Fork of Ninnescah River,...

  12. Dating sediment in a fast sedimentation reservoir using 137Cs and 210Pb

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 10,000 reservoirs have been constructed in agricultural watersheds in the United States since the 1940s to control floods and sediments. Reservoir sedimentation records provide a unique opportunity to retrospectively study the effects of land use changes and climate variations on sediment produ...

  13. Estimating Reservoir Sedimentation Rates: Long-Term Implications for California's Reservoirs

    NASA Astrophysics Data System (ADS)

    Minear, J. T.; Kondolf, G. M.

    2004-12-01

    This paper presents a compilation and analysis of reservoir sedimentation rates applied to unsurveyed reservoirs in California. A number of reservoirs, primarily in the Coast Ranges, have already filled or are nearly filled with sediment and are being considered for removal, including the Matilija, San Clemente, Rindge and Searsville Dams. Of the over 1,400 dams in California listed in the National Inventory of Dams (NID), only 213 (15%) have been surveyed for reservoir sedimentation, presenting a significant gap in current knowledge. Using previously published reports on reservoir sedimentation rates (excluding flood control and debris flow basins), we determined the median reservoir sedimentation rates for the nine different geomorphic regions in California. For the geomorphic regions with sedimentation data, the median sedimentation rate +/- standard error in m3 km-2 yr-1, and (number of measured reservoirs) are: Siskiyou: 340 +/- 170 (3), Coast Range: 220 +/- 50 (49), Central Valley: 145 +/- 90 (5), Sierra Nevada: 95 +/- 25 (23), Transverse Range: 500 +/- 200 (18), and Peninsular Range: 260 +/- 185 (4). These reservoir sedimentation rates were then applied to the unsurveyed reservoirs. Of the approximately 42 million acre-feet of water storage in the state, approximately 5.14 million acre-feet may be currently occupied by sediment, representing a significant decrease of 12% of the state's water supply. Using the same rates to forecast the effects after 50-years, we found that the reservoirs with most risk of sedimentation are primarily small reservoirs (<2,500 acre-feet), such as municipal water-supply reservoirs, especially those operated by coastal towns and cities. Reservoirs in the Coast and Transverse Ranges are the most at risk, with high sedimentation rates, small reservoirs on large watersheds, and older reservoirs. There are over twenty reservoirs that will likely be full or nearly full in 50-years, including Tinemaha, Pleasant Valley, Lee Lake

  14. Model Study on Potential Contributions of the Proposed Huangpu Gate to Flood Control in Taihu Lake Basin

    NASA Astrophysics Data System (ADS)

    Liu, S.; Zhang, H.; Ye, J.

    2015-12-01

    The Taihu Lake basin, one of the most developed and dynamic regions, is located in the hinterland of the Yangtze River Delta, Eastern China. The largest flood in history is the 1999 flood event with a return period of 1 in 200 years, which is above the current capacity of flooding defense in the basin with a return period of 1 in 50 years. Due to its flat saucer-like terrain, the capacity of the flood control system is dependent on the flood defense infrastructure and the peripheral tidal conditions. The Huangpu River, connecting the Taihu Lake and the Yangtze River, is one of the major drains, which is strongly influenced by high tide conditions in the coastal waters of the Yangtze River. Hence, constructing an estuary gate is considered one of the effective solutions to the flooding problem in the basin. This paper aims to quantitatively analyze the potential contributions of the proposed Huangpu gate to flood control capacity of the basin under various flooding scenarios. It is concluded that the Huangpu gate is an effective mean to evacuate the floodwaters, by reducing peak levels in the upper part of the tide-affected river. It's beneficiaries include the Taihu Lake, the related surrounding areas along the Taipu Canal and the Huangpu River basin. Keywords: Flood control, Estuary gate, Taihu Lake Basin, Scenario analysis, Tide intrusion

  15. Decision support system for optimal reservoir operation modeling within sediment deposition control.

    PubMed

    Hadihardaja, Iwan K

    2009-01-01

    Suspended sediment deals with surface runoff moving toward watershed affects reservoir sustainability due to the reduction of storage capacity. The purpose of this study is to introduce a reservoir operation model aimed at minimizing sediment deposition and maximizing energy production expected to obtain optimal decision policy for both objectives. The reservoir sediment-control operation model is formulated by using Non-Linear Programming with an iterative procedure based on a multi-objective measurement in order to achieve optimal decision policy that is established in association with the development of a relationship between stream inflow and sediment rate by utilizing the Artificial Neural Network. Trade off evaluation is introduced to generate a strategy for controlling sediment deposition at same level of target ratio while producing hydroelectric energy. The case study is carried out at the Sanmenxia Reservoir in China where redesign and reconstruction have been accomplished. However, this model deals only with the original design and focuses on a wet year operation. This study will also observe a five-year operation period to show the accumulation of sediment due to the impact of reservoir storage capacity. PMID:19214002

  16. Improving Gas Flooding Efficiency

    SciTech Connect

    Reid Grigg; Robert Svec; Zheng Zeng; Alexander Mikhalin; Yi Lin; Guoqiang Yin; Solomon Ampir; Rashid Kassim

    2008-03-31

    This study focuses on laboratory studies with related analytical and numerical models, as well as work with operators for field tests to enhance our understanding of and capabilities for more efficient enhanced oil recovery (EOR). Much of the work has been performed at reservoir conditions. This includes a bubble chamber and several core flood apparatus developed or modified to measure interfacial tension (IFT), critical micelle concentration (CMC), foam durability, surfactant sorption at reservoir conditions, and pressure and temperature effects on foam systems.Carbon dioxide and N{sub 2} systems have been considered, under both miscible and immiscible conditions. The injection of CO2 into brine-saturated sandstone and carbonate core results in brine saturation reduction in the range of 62 to 82% brine in the tests presented in this paper. In each test, over 90% of the reduction occurred with less than 0.5 PV of CO{sub 2} injected, with very little additional brine production after 0.5 PV of CO{sub 2} injected. Adsorption of all considered surfactant is a significant problem. Most of the effect is reversible, but the amount required for foaming is large in terms of volume and cost for all considered surfactants. Some foams increase resistance to the value beyond what is practical in the reservoir. Sandstone, limestone, and dolomite core samples were tested. Dissolution of reservoir rock and/or cement, especially carbonates, under acid conditions of CO2 injection is a potential problem in CO2 injection into geological formations. Another potential change in reservoir injectivity and productivity will be the precipitation of dissolved carbonates as the brine flows and pressure decreases. The results of this report provide methods for determining surfactant sorption and can be used to aid in the determination of surfactant requirements for reservoir use in a CO{sub 2}-foam flood for mobility control. It also provides data to be used to determine rock permeability

  17. Growing magma chambers control the distribution of small-scale flood basalts

    PubMed Central

    Yu, Xun; Chen, Li-Hui; Zeng, Gang

    2015-01-01

    Small-scale continental flood basalts are a global phenomenon characterized by regular spatio-temporal distributions. However, no genetic mechanism has been proposed to explain the visible but overlooked distribution patterns of these continental basaltic volcanism. Here we present a case study from eastern China, combining major and trace element analyses with Ar–Ar and K–Ar dating to show that the spatio-temporal distribution of small-scale flood basalts is controlled by the growth of long-lived magma chambers. Evolved basalts (SiO2 > 47.5 wt.%) from Xinchang–Shengzhou, a small-scale Cenozoic flood basalt field in Zhejiang province, eastern China, show a northward younging trend over the period 9.4–3.0 Ma. With northward migration, the magmas evolved only slightly ((Na2O + K2O)/MgO = 0.40–0.66; TiO2/MgO = 0.23–0.35) during about 6 Myr (9.4–3.3 Ma). When the flood basalts reached the northern end of the province, the magmas evolved rapidly (3.3–3.0 Ma) through a broad range of compositions ((Na2O + K2O)/MgO = 0.60–1.28; TiO2/MgO = 0.30–0.57). The distribution and two-stage compositional evolution of the migrating flood basalts record continuous magma replenishment that buffered against magmatic evolution and induced magma chamber growth. Our results demonstrate that the magma replenishment–magma chamber growth model explains the spatio-temporal distribution of small-scale flood basalts. PMID:26581905

  18. Growing magma chambers control the distribution of small-scale flood basalts

    NASA Astrophysics Data System (ADS)

    Yu, Xun; Chen, Li-Hui; Zeng, Gang

    2015-11-01

    Small-scale continental flood basalts are a global phenomenon characterized by regular spatio-temporal distributions. However, no genetic mechanism has been proposed to explain the visible but overlooked distribution patterns of these continental basaltic volcanism. Here we present a case study from eastern China, combining major and trace element analyses with Ar-Ar and K-Ar dating to show that the spatio-temporal distribution of small-scale flood basalts is controlled by the growth of long-lived magma chambers. Evolved basalts (SiO2 > 47.5 wt.%) from Xinchang-Shengzhou, a small-scale Cenozoic flood basalt field in Zhejiang province, eastern China, show a northward younging trend over the period 9.4-3.0 Ma. With northward migration, the magmas evolved only slightly ((Na2O + K2O)/MgO = 0.40-0.66 TiO2/MgO = 0.23-0.35) during about 6 Myr (9.4-3.3 Ma). When the flood basalts reached the northern end of the province, the magmas evolved rapidly (3.3-3.0 Ma) through a broad range of compositions ((Na2O + K2O)/MgO = 0.60-1.28 TiO2/MgO = 0.30-0.57). The distribution and two-stage compositional evolution of the migrating flood basalts record continuous magma replenishment that buffered against magmatic evolution and induced magma chamber growth. Our results demonstrate that the magma replenishment-magma chamber growth model explains the spatio-temporal distribution of small-scale flood basalts.

  19. Growing magma chambers control the distribution of small-scale flood basalts.

    PubMed

    Yu, Xun; Chen, Li-Hui; Zeng, Gang

    2015-01-01

    Small-scale continental flood basalts are a global phenomenon characterized by regular spatio-temporal distributions. However, no genetic mechanism has been proposed to explain the visible but overlooked distribution patterns of these continental basaltic volcanism. Here we present a case study from eastern China, combining major and trace element analyses with Ar-Ar and K-Ar dating to show that the spatio-temporal distribution of small-scale flood basalts is controlled by the growth of long-lived magma chambers. Evolved basalts (SiO2 > 47.5 wt.%) from Xinchang-Shengzhou, a small-scale Cenozoic flood basalt field in Zhejiang province, eastern China, show a northward younging trend over the period 9.4-3.0 Ma. With northward migration, the magmas evolved only slightly ((Na2O + K2O)/MgO = 0.40-0.66; TiO2/MgO = 0.23-0.35) during about 6 Myr (9.4-3.3 Ma). When the flood basalts reached the northern end of the province, the magmas evolved rapidly (3.3-3.0 Ma) through a broad range of compositions ((Na2O + K2O)/MgO = 0.60-1.28; TiO2/MgO = 0.30-0.57). The distribution and two-stage compositional evolution of the migrating flood basalts record continuous magma replenishment that buffered against magmatic evolution and induced magma chamber growth. Our results demonstrate that the magma replenishment-magma chamber growth model explains the spatio-temporal distribution of small-scale flood basalts. PMID:26581905

  20. ACOUSTIC PROFILING OF SEDIMENT ACCUMULATION IN THREE SMALL EROSION CONTROL RESERVOIRS IN NORTH MISSISSIPPI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Northern Mississippi, as part of a preventative erosion control program, the Yazoo-Little Tallahatchie Project (YLTP) created a system of small dams and reservoirs to regulate stream flow and to stop the movement of sediment over large distances. These structures were designed to have a lifetime ...

  1. Operational flood control of a low-lying delta system using large time step Model Predictive Control

    NASA Astrophysics Data System (ADS)

    Tian, Xin; van Overloop, Peter-Jules; Negenborn, Rudy R.; van de Giesen, Nick

    2015-01-01

    The safety of low-lying deltas is threatened not only by riverine flooding but by storm-induced coastal flooding as well. For the purpose of flood control, these deltas are mostly protected in a man-made environment, where dikes, dams and other adjustable infrastructures, such as gates, barriers and pumps are widely constructed. Instead of always reinforcing and heightening these structures, it is worth considering making the most of the existing infrastructure to reduce the damage and manage the delta in an operational and overall way. In this study, an advanced real-time control approach, Model Predictive Control, is proposed to operate these structures in the Dutch delta system (the Rhine-Meuse delta). The application covers non-linearity in the dynamic behavior of the water system and the structures. To deal with the non-linearity, a linearization scheme is applied which directly uses the gate height instead of the structure flow as the control variable. Given the fact that MPC needs to compute control actions in real-time, we address issues regarding computational time. A new large time step scheme is proposed in order to save computation time, in which different control variables can have different control time steps. Simulation experiments demonstrate that Model Predictive Control with the large time step setting is able to control a delta system better and much more efficiently than the conventional operational schemes.

  2. Flood control embankments contribute to the improvement of the health status of children in rural Bangladesh.

    PubMed

    Myaux, J A; Ali, M; Chakraborty, J; de Francisco, A

    1997-01-01

    Every year, Bangladesh experiences major floods that inundate about one-third of the country. Therefore, flood control projects that comprise earthen dikes and irrigation/drainage systems are built along the major rivers to protect the people living in low-lying areas, stabilize the river banks and improve agricultural productivity. However, the adverse effects of these projects are regularly emphasized, such as environmental degradation and reduction of fishing supplies. The Demographic Surveillance System of the International Centre for Diarrhoeal Diseases Research, Bangladesh (ICDDR,B) was used to assess the effect of a flood control programme on the mortality of 0-4-year-old children residing in the Matlab study area. Adjusted mortality rates were used in comparing four adjacent child populations residing either inside or outside a flood-control embankment and according to the type of health services provided in this area. Between the periods 1983-86 and 1989-92, the crude child mortality in the total study area decreased by 37%, from 185.9 per 1000 live births to 117.9 per 1000 live births. Following the construction of the embankment, death rates outside were up to 29% higher in 1-4-year-old children and 9% higher for 0-4-year age group compared to the flood-protected area (P < 0.001). Simultaneously, in the same study area, health interventions contributed to a 40% reduction in mortality among children less than 5 years of age in all causes of deaths (P < 0.001). Migration patterns and the effect of distances to the hospital are discussed. PMID:9509625

  3. A Constrained Differential Evolution Algorithm for Reservoir Management: Optimal Placement and Control of Wells for Geological Carbon Storage with Uncertainty in Reservoir Properties

    NASA Astrophysics Data System (ADS)

    Cihan, A.; Birkholzer, J. T.; Bianchi, M.

    2014-12-01

    Injection of large volume of CO2 into deep geological reservoirs for geologic carbon sequestration (GCS) is expected to cause significant pressure perturbations in subsurface. Large-scale pressure increases in injection reservoirs during GCS operations, if not controlled properly, may limit dynamic storage capacity and increase risk of environmental impacts. The high pressure may impact caprock integrity, induce fault slippage, and cause leakage of brine and/or CO2 into shallow fresh groundwater resources. Thus, monitoring and controlling pressure buildup are critically important for environmentally safe implementation of GCS projects. Extraction of native brine during GCS operations is a pressure management approach to reduce significant pressure buildup. Extracted brine can be transferred to the surface for utilization or re-injected into overlying/underlying saline aquifers. However, pumping, transportation, treatment and disposal of extracted brine can be challenging and costly. Therefore, minimizing volume of extracted brine, while maximizing CO2 storage, is an essential objective of the pressure management with brine extraction schemes. Selection of optimal well locations and extraction rates are critical for maximizing storage and minimizing brine extraction during GCS. However, placing of injection and extraction wells is not intuitive because of heterogeneity in reservoir properties and complex reservoir geometry. Efficient computerized algorithms combining reservoir models and optimization methods are needed to make proper decisions on well locations and control parameters. This study presents a global optimization methodology for pressure management during geologic CO2 sequestration. A constrained differential evolution (CDE) algorithm is introduced for solving optimization problems involving well placement and injection/extraction control. The CDE methodology is tested and applied for realistic CO2 storage scenarios with the presence of uncertainty in

  4. Subtask 1.17 - Measurement of Hydrocarbon Evolution from Coal and Petroleum Reservoirs Under Carbon Dioxide Floods

    SciTech Connect

    Steven B. Hawthorne

    2006-12-31

    The project developed, built, and tested three apparatuses for studying different interactions of carbon dioxide with geologic materials. In Year 1, an online instrument was constructed by coupling a high-pressure carbon dioxide extraction system with a flame ionization detector that can yield a real-time profile and quantitative measurements of hydrocarbons removed from materials such as coal and petroleum reservoir rock. In Years 2 and 3, one instrument was built to measure the excess sorption of carbon dioxide in geologic materials such as coal and showed that measurable uptake of carbon dioxide into the coal matrix is rapid. The final apparatus was built to expose geologic materials to carbon dioxide for long periods of time (weeks to months) under the range of pressures and temperatures relevant to carbon dioxide sequestration. The apparatus allows as many as twenty gram-sized samples of geologic materials to be exposed simultaneously and can also include exposures with geologic brines. The system was used to demonstrate complete conversion of magnesium silicate to magnesium carbonate in less than 4 weeks when exposed to clean water or brine, compared to no measurable conversion of dry magnesium carbonate.

  5. Structural controls on fractured coal reservoirs in the southern Appalachian Black Warrior foreland basin

    USGS Publications Warehouse

    Groshong, R.H., Jr.; Pashin, J.C.; McIntyre, M.R.

    2009-01-01

    Coal is a nearly impermeable rock type for which the production of fluids requires the presence of open fractures. Basin-wide controls on the fractured coal reservoirs of the Black Warrior foreland basin are demonstrated by the variability of maximum production rates from coalbed methane wells. Reservoir behavior depends on distance from the thrust front. Far from the thrust front, normal faults are barriers to fluid migration and compartmentalize the reservoirs. Close to the thrust front, rates are enhanced along some normal faults, and a new trend is developed. The two trends have the geometry of conjugate strike-slip faults with the same ??1 direction as the Appalachian fold-thrust belt and are inferred to be the result of late pure-shear deformation of the foreland. Face cleat causes significant permeability anisotropy in some shallow coal seams but does not produce a map-scale production trend. ?? 2008 Elsevier Ltd. All rights reserved.

  6. Structurally controlled and aligned tight gas reservoir compartmentalization in the San Juan and Piceance Basins

    SciTech Connect

    Decker, A.D.; Kuuskraa, V.A.; Klawitter, A.L.

    1995-10-01

    Recurrent basement faulting is the primary controlling mechanism for aligning and compartmentalizing upper Cretaceous aged tight gas reservoirs of the San Juan and Piceance Basins. Northwest trending structural lineaments that formed in conjunction with the Uncompahgre Highlands have profoundly influenced sedimentation trends and created boundaries for gas migration; sealing and compartmentalizing sedimentary packages in both basins. Fractures which formed over the structural lineaments provide permeability pathways which allowing gas recovery from otherwise tight gas reservoirs. Structural alignments and associated reservoir compartments have been accurately targeted by integrating advanced remote sensing imagery, high resolution aeromagnetics, seismic interpretation, stratigraphic mapping and dynamic structural modelling. This unifying methodology is a powerful tool for exploration geologists and is also a systematic approach to tight gas resource assessment in frontier basins.

  7. Axial obliquity control on the greenhouse carbon budget through middle- to high-latitude reservoirs

    NASA Astrophysics Data System (ADS)

    Laurin, Jiří; Meyers, Stephen R.; Uličný, David; Jarvis, Ian; Sageman, Bradley B.

    2015-02-01

    Carbon sources and sinks are key components of the climate feedback system, yet their response to external forcing remains poorly constrained, particularly for past greenhouse climates. Carbon-isotope data indicate systematic, million-year-scale transfers of carbon between surface reservoirs during and immediately after the Late Cretaceous thermal maximum (peaking in the Cenomanian-Turonian, circa 97-91 million years, Myr, ago). Here we calibrate Albian to Campanian (108-72 Myr ago) high-resolution carbon isotope records with a refined chronology and demonstrate how net transfers between reservoirs are plausibly controlled by ~1 Myr changes in the amplitude of axial obliquity. The amplitude-modulating terms are absent from the frequency domain representation of insolation series and require a nonlinear, cumulative mechanism to become expressed in power spectra of isotope time series. Mass balance modeling suggests that the residence time of carbon in the ocean-atmosphere system is—by itself—insufficient to explain the Myr-scale variability. It is proposed that the astronomical control was imparted by a transient storage of organic matter or methane in quasi-stable reservoirs (wetlands, soils, marginal zones of marine euxinic strata, and potentially permafrost) that responded nonlinearly to obliquity-driven changes in high-latitude insolation and/or meridional insolation gradients. While these reservoirs are probably underrepresented in the geological record due to their quasi-stable character, they might have provided an important control on the dynamics and stability of the greenhouse climate.

  8. A methodology to evaluate regional hydraulic controls on flow from hydrocarbon reservoirs into overlying aquifers

    SciTech Connect

    Fryar, A.E.; Kreitler, C.W.; Akhter, M.C.

    1994-09-01

    Because drilling, completion, and abandonment practices for oil and gas wells have improved over the past century, some older abandoned wells may be mechanically deficient or inadequately plugged, thus posing a risk of contamination to underground sources of drinking water. The risk of saltwater contamination of freshwater aquifers through inadequately plugged, abandoned wells increases if the hydraulic potential of the oil- and-gas-bearing brine formations is higher than that in the overlying freshwater aquifers. First, average regional potentiometric surfaces of aquifers and reservoirs are generated from aquifer water-level measurements and the conversion of bottom-hole pressure measurements from oil and gas reservoirs to hydraulic heads. Next, differences in hydraulic heads between aquifers and reservoirs are calculated to delineate regional residual areas of upward (positive) or downward (negative) hydraulic gradients. Third, locations of abandoned wells and class II injection wells are plotted relative to residuals to examine where water flooding, pressure maintenance, and saltwater disposal may cause or exacerbate the potential for upward flow. Three areas were used as case studies for testing the method. Positive residuals in the South Texas basin (informally defined to include the Val Verde basin, Maverick basin, part of the Rio Grande Salt basin, and the Austin Chalk trend) result from natural geopressuring in formations deeper than 6000 ft, which are negligibly affected by class II injection wells. Positive residuals in the greater Permian basin (including the northwestern shelf, Delaware basin, part of the Palo Duro basin, Central Basin platform, Midland basin, southern shelf, and Fort Worth basin) may reflect injection for enhanced recovery in the west and natural hydrologic processes in the eastern shelf region. Residual surfaces for the San Juan basin indicate several areas with a natural potential for upward migration of brine.

  9. An Analytical Framework for Flood Water Conservation Considering Forecast Uncertainty and Acceptable Risk

    NASA Astrophysics Data System (ADS)

    Ding, W.; Zhang, C.

    2015-12-01

    Reservoir water levels are usually not allowed to exceed the flood limited water level (FLWL) during flood season, which neglects the meteorological and real-time forecast information and leads to the great waste of water resources. With the development of weather forecasting, hydrologic modeling, and hydro-climatic teleconnection, the streamflow forecast precision have improved a lot, which provides the technical support for the flood water utilization. This paper addresses how much flood water can be conserved for use after the flood season through the operation of reservoir based on uncertain forecast information by taking into account the residual flood control capacity (the difference between flood conveyance capacity and the expected inflow in a lead time). A two-stage model for dynamic control of the flood limited water level (the maximum allowed water level during the flood season, DC-FLWL) is established considering forecast uncertainty and acceptable flood risk. It is found that DC-FLWL is applicable when the reservoir inflow ranges from small to medium levels of the historical records, while both forecast uncertainty and acceptable risk in the downstream affect the feasible space of DC-FLWL. As forecast uncertainty increases (under a given risk level) or as acceptable risk level decreases (under a given forecast uncertainty level), the minimum required safety margin for flood control increases, and the chance for DC-FLWL decreases. The derived hedging rules from the modeling framework illustrate either the dominant role of water conservation or flood control or the tradeoff between the two objectives under different levels of forecast uncertainty and acceptable risk. These rules may provide useful guidelines for conserving water from flood, especially in the area with heavy water stress.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    USGS Publications Warehouse

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

    2014-01-01

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

  12. POLLUTION PREVENTION OPPORTUNITY ASSESSMENT AT THE U.S. ARMY CORPS OF ENGINEERS JOHN H. KERR DAM AND RESERVOIR - BOYDTON, VIRGINIA

    EPA Science Inventory

    The report describes the results of pollution prevention opportunity assessments conducted at a representative U.S. Army Corps of Engineers civil works facilities including a flood control reservoir and associated public use areas. ecommended methods for reducing pollution result...

  13. STUDY ON FLOOD CONTROL PROPERTIES OF PERMEABLE PAVEMENT USING SATURATED-UNSATURATED SEEPAGE ANALYSIS

    NASA Astrophysics Data System (ADS)

    Yano, Takao; Nishiyama, Satoshi; Ohnishi, Yuzo; Nakashima, Shinichiro; Moriishi, Kazushi; Wada, Minoru

    The rainfall storage and infiltration facility of permeable pavement have been attracted attention as a control measure of flood and an environmental improvement measure in urban areas. However, rainfall infiltration of permeable pavement is unsteady flow and strongly dependent on the behavior of unsaturated zones in the pavement. Moreover, the wet condition of subbase course also has a great influence on the rainfall infiltration of the pavement. That's why previous studies have not made clear the precise the facility of permeable pavement as a flood control. In this paper, experimental studies and simulated analyses were performed to measure the overflow from the pavement under various conditions of rainfall intensities and estimate the rainfall infiltration of the pavement using the measurement data and unsaturated infiltration characteristics of porous asphalt materials. It is clear that this study shows the methods to have a quantitative estimation of the rainfall storage and infiltration facility of permeable pavement.

  14. Hydrologic effects of area B flood control plan on urbanization of Dade County, Florida

    USGS Publications Warehouse

    Kohout, F.A.; Hartwell, J.H.

    1967-01-01

    Swampy low land (Area B) that fringes the Everglades west of Metropolitan Miami, Florida (Area A) probably will be urbanized in the future. Area B will be protected from flooding by huge pumps that will pump water westward from Area B over a levee system into Conservation Area 3B. The total capacity of the pumps will be about 13,400 cubic feet per second which is sufficient to lower water levels 2 inches per day in the 203 square miles of Area B. As this capacity is about equal to the highest gravity-flow discharge to the ocean through existing canals of the Miami area, a great potential. will exist, not only for control of floods, but also for beneficial control and management of a major segment of the water resources in southeastern Florida.

  15. MULTI-RESERVOIR BIOADHESIVE MICRODEVICES FOR INDEPENDENT RATE-CONTROLLED DELIVERY OF MULTIPLE DRUGS

    PubMed Central

    Chirra, Hariharasudhan D.; Desai, Tejal A.

    2012-01-01

    A variety of oral administrative systems such as enterically coated tablets, capsules, particles, and liposomes have been developed to improve oral bioavailability of drugs. However, they suffer from poor intestinal localization and therapeutic efficacy due to the various physiological conditions and high shear fluid flow. Fabrication of novel microdevices combined with the introduction of controlled release, improved adhesion, selective targeting, and tissue permeation may overcome these issues and potentially diminish the toxicity and high frequency of conventional oral administration. Herein, thin, asymmetric, poly(methyl methacrylate); PMMA microdevices were fabricated with multiple reservoirs using photolithography and reactive ion etching. They were loaded with different individual model drug in each reservoir. Enhanced bioadhesion of the microdevices was observed in the presence of a conjugated of targeting protein; tomato lectin to the PMMA surface. As compared to drug encompassing hydrogels, an increase in drug permeation across the caco-2 monolayer was noticed in the presence of a microdevice loaded with the same drug-hydrogel system. Also, the release of multiple drugs from their respective reservoirs was found to be independent from each other. The use of different hydrogel systems in each reservoir showed differences in the controlled release of the respective drugs over the same period of release. These results suggest that in the future, the microfabricated unidirectional multi-drug releasing devices will have an impact over the oral administration of a broad range of therapeutics. PMID:22962019

  16. Hydrologic Flood Routing.

    ERIC Educational Resources Information Center

    Heggen, Richard J.

    1982-01-01

    Discusses a short classroom-based BASIC program which routes stream flow through a system of channels and reservoirs. The program is suitable for analyses of open channel conveyance systems, flood detention reservoirs, and combinations of the two. (Author/JN)

  17. A Decision Support System (talsim) For Integrated Management of Reservoir Controlled Watersheds

    NASA Astrophysics Data System (ADS)

    Lohr, H.; Ostrowski, M.; Leichtfuss, A.

    Both, the European Water Framework Directives and the discussion of the report of the world commission on dams (WCD-Report) ask for efficient and transparent decision support tools for rivers and river basins controlled by reservoir systems. It is evident that in contrast to historical planning conditions new objectives according to sustain- ability criteria have to be considered. Also, climate and land use changes have to be considered to account for changes of the hydrological cycle. In addition to river basin management dam safety has become a major issue in recent European discussions. In most cases decision support systems for reservoir systems have been individually tai- lored systems being only applicable to the system they had been developed for. Any transfer to other systems was strongly restricted as system definition and operation rules were implemented in the program code. Thus, a generic DSS for reservoir sys- tems modelling and optimisation is required to serve as a basic tool to support reser- voir operators and water administration to account for new objectives under changing boundary conditions. During the last six years a DSS for reservoir systems including their catchments and river reaches has been developed to fulfill these requirements (named TALSIM). The work has been supported by the Environmental Agency of the German Federal State of North-Rhine Westfalia. During the development and test phases the DSS has been applied to several reservoir systems in Germany and Africa. At present it is applied to one of the most complex German systems. The scope of the presentation is to present - the new requirements for decision making procedures in reservoir management - the structure of the TALSIM DSS including simulation and optimisation modules - completed and ongoing case studies

  18. Rhizosphere dynamics of two riparian plant species from the water fluctuation zone of Three Gorges Reservoir, P.R. China - pH, oxygen and LMWOA monitoring during short flooding events

    NASA Astrophysics Data System (ADS)

    Schreiber, Christina M.; Schurr, Ulrich; Zeng, Bo; Höltkemeier, Agnes; Kuhn, Arnd J.

    2010-05-01

    Since the construction of the Three Gorges Dam at the Yangtze River in China, the reservoir management created a new 30m water fluctuation zone 45-75m above the original water level. Only species well adapted to long-time flooding (up to several months) will be able to vegetate the river banks and replace the original vegetation. To investigate how common species of the riverbanks cope with submergence, Alternanthera philoxeroides Mart. and Arundinella anomala Steud., two flooding resistant riparian species, have been examined in a rhizotron environment. Short-time (2 days waterlogging, 2 days flooding, 2 days recovery) flooding cycles in the original substrate and long time (14 days waterlogging, flooding, recovery) flooding cycles, in original substrate and sterile glass bead substrate, have been simulated in floodable two-way access rhizotrons. Oxygen- and pH-sensitive foils (planar optodes, PreSens) automatically monitored root reaction in a confined space (2cm2 each) on the backside of the rhizotron, while soil solution samples were taken 2 times a day from the other side of the rhizotron at the corresponding area through filter and steel capillaries. The samples were analyzed by capillary electrophoresis for low molecular weight organic acids (LMWOA, i.e. oxalic, formic, succinic, malic, acetic, glyoxylic, lactic and citric acid). Results show diurnal rhythms of rhizospheric acidification for both species in high resolution, combined with oxygen entry into the root surrounding during waterlogged state. Flooding caused stronger acidification in the rhizosphere, that were however not accompanied by increased occurrence of LMWOA except for acetic and glyoxylic acid. First results from longer flooding periods show stable diurnal rhythms during waterlogging, but no strongly increased activity during the flooding event. Performance of the two species is not hampered by being waterlogged, and they follow a silencing strategy during a longer phase of anoxia without

  19. Mobility control experience in the Joffre Viking miscible CO[sub 2] flood

    SciTech Connect

    Luhning, R.W. ); Stephenson, D.J.; Graham, A.G.

    1993-08-01

    This paper discusses mobility control in the Joffre Viking field miscible CO[sub 2] flood. Since 1984, three injection strategies have been tried: water-alternating-CO[sub 2] (WACO[sub 2]), continuous CO[sub 2], and simultaneous CO[sub 2] and water. The studies showed that simultaneous injection results in the best CO[sub 2] conformance. CO[sub 2]-foam injection has also been investigated.

  20. Reservoir controling factors in the Karaha-Telaga Bodas geothermal field, Indonesia

    USGS Publications Warehouse

    Nemcok, M.; Moore, J.N.; Christensen, Carl; Allis, R.; Powell, T.; Murray, B.; Nash, G.

    2005-01-01

    Karaha - Telaga Bodas geothermal system consists of: 1) a caprock, ranging from several hundred meters to 1600 m thick that is characterized by steep, conductive temperature gradients and low permeabilities; 2) an underlying vapor-dominated zone that extends below sea level; and 3) a deep liquid-dominated zone with measured temperatures up to 353??C. Heat is provided by a 3 km deep tabular granodiorite stock. The effective base of the reservoir is controlled by the stress regime's effect on fractures within volcanic rocks located above the brittle/ductile deformation boundary. The base of the caprock is controlled by the distribution of initially low-permeability lithologies above the reservoir; the extent of pervasive clay alteration that has reduced initial permeabilities; the distribution of secondary minerals deposited by descending waters; and by a downward change from a strike-slip to an extensional stress regime. Producing zones are controlled by both matrix and fracture permeabilities.

  1. Controlling Catalyst Bulk Reservoir Effects for Monolayer Hexagonal Boron Nitride CVD

    PubMed Central

    2016-01-01

    Highly controlled Fe-catalyzed growth of monolayer hexagonal boron nitride (h-BN) films is demonstrated by the dissolution of nitrogen into the catalyst bulk via NH3 exposure prior to the actual growth step. This “pre-filling” of the catalyst bulk reservoir allows us to control and limit the uptake of B and N species during borazine exposure and thereby to control the incubation time and h-BN growth kinetics while also limiting the contribution of uncontrolled precipitation-driven h-BN growth during cooling. Using in situ X-ray diffraction and in situ X-ray photoelectron spectroscopy combined with systematic growth calibrations, we develop an understanding and framework for engineering the catalyst bulk reservoir to optimize the growth process, which is also relevant to other 2D materials and their heterostructures. PMID:26756610

  2. Controlling Catalyst Bulk Reservoir Effects for Monolayer Hexagonal Boron Nitride CVD.

    PubMed

    Caneva, Sabina; Weatherup, Robert S; Bayer, Bernhard C; Blume, Raoul; Cabrero-Vilatela, Andrea; Braeuninger-Weimer, Philipp; Martin, Marie-Blandine; Wang, Ruizhi; Baehtz, Carsten; Schloegl, Robert; Meyer, Jannik C; Hofmann, Stephan

    2016-02-10

    Highly controlled Fe-catalyzed growth of monolayer hexagonal boron nitride (h-BN) films is demonstrated by the dissolution of nitrogen into the catalyst bulk via NH3 exposure prior to the actual growth step. This "pre-filling" of the catalyst bulk reservoir allows us to control and limit the uptake of B and N species during borazine exposure and thereby to control the incubation time and h-BN growth kinetics while also limiting the contribution of uncontrolled precipitation-driven h-BN growth during cooling. Using in situ X-ray diffraction and in situ X-ray photoelectron spectroscopy combined with systematic growth calibrations, we develop an understanding and framework for engineering the catalyst bulk reservoir to optimize the growth process, which is also relevant to other 2D materials and their heterostructures. PMID:26756610

  3. Understanding Satellite-based Monthly-to-Seasonal Reservoir Outflow Estimation as a function of Hydrologic Controls

    NASA Astrophysics Data System (ADS)

    Bonnema, M.; Sikder, M. S.; Hossain, F.; Chen, X.; Miao, Y.; Lee, H.

    2015-12-01

    Growing population and increased demand for water in developing nations is causing an increase in dam construction in these regions. Entities and stakeholders downstream of dams experience drastically altered river flows. When rivers cross international boundaries, these downstream stakeholders often have little knowledge of upstream reservoir operation practices. Satellite remote sensing in the form of radar altimetry and multi-sensor precipitation products can be used as a way to provide downstream stakeholders with the upstream information needed to make important water management decisions. This study uses a mass balance between three hydraulic controls, precipitation induced inflow, evaporation, and reservoir storage change, to estimate reservoir outflow at a monthly time scale. Two reservoirs were examined in differing regions of the world, the Hungry Horse Reservoir in a mountainous region in northwest U.S. and the Kaptai Reservoir in a low-lying, forested region of Bangladesh. It was found that this mass balance method estimated the outflow of Kaptai Reservoir with reasonable skill when compared with observed flows. The estimation of outflow from Hungry Horse Reservoir was similarly skillful for outflows in winter and fall months, but summer and spring outflow estimates had high errors due to snowmelt effects. Furthermore, it was found that the important hydrologic controls for reservoir outflow estimation at the monthly time scale differs between the two reservoirs, with precipitation induced inflow being the most important control for the Kaptai Reservoir and storage change being the most important for Hungry Horse Reservoir. In both cases, a standard energy balance approach of evaporation estimation appeared to have little effect on the accuracy of outflow estimation.

  4. California's Yolo Bypass: Evidence that flood control can be compatible with fisheries, wetlands, wildlife, and agriculture

    USGS Publications Warehouse

    Sommer, T.; Harrell, B.; Nobriga, M.; Brown, R.; Moyle, P.B.; Kimmerer, W.; Schemel, Laurence E.

    2001-01-01

    Unlike conventional flood control systems that frequently isolate rivers from ecologically-essential floodplain habitat, California's Yolo Bypass has been engineered to allow Sacramento Valley floodwaters to inundate a broad floodplain. From a flood control standpoint, the 24,000 ha leveed floodplain has been exceptionally successful based on its ability to convey up to 80% of the flow of the Sacramento River basin during high water events. Agricultural lands and seasonal and permanent wetlands within the bypass provide key habitat for waterfowl migrating through the Pacific Flyway. Our field studies demonstrate that the bypass seasonally supports 42 fish species, 15 of which are native. The floodplain appears to be particularly valuable spawning and rearing habitat for the splittail (Pogonichthys macrolepidotus), a federally-listed cyprinid, and for young chinook salmon (Oncorhynchus tshawytscha), which use the Yolo Bypass as a nursery area. The system may also be an important source to the downstream food web of the San Francisco Estuary as a result of enhanced production of phytoplankton and detrital material. These results suggest that alternative flood control systems can be designed without eliminating floodplain function and processes, key goals of the 1996 Draft AFS Floodplain Management Position Statement.

  5. Optimal control of polymer flooding based on mixed-integer iterative dynamic programming

    NASA Astrophysics Data System (ADS)

    Lei, Yang; Li, Shurong; Zhang, Xiaodong; Zhang, Qiang; Guo, Lanlei

    2011-11-01

    Polymer flooding is one of the most important technologies for enhanced oil recovery. In this article, a mixed-integer optimal control model of distributed parameter systems (DPS) for the injection strategies is established, which involves the performance index as maximum of the profit, the governing equations as the fluid flow equations of polymer flooding and some inequalities constraints, such as polymer concentration and injection amount limitation. The control variables are the volume size, the injection concentration of each slug and the terminal flooding time. For the constant injection rate, the slug size is determined by the integer time stage length, and thus the integer variables are introduced in the DPS. To cope with the optimal control problem (OCP) of this DPS, a mixed-integer iterative dynamic programming incorporating a special truncation procedure to handle integer restrictions on stage lengths is proposed. First, the OCP with variable time stage lengths is transformed into a fixed time stage problem by introducing a normalised time variable. Then, the optimisation procedure is carried out at each stage and preceded backwards in a systematic way. Finally, the numerical results of an example illustrate the effectiveness of the proposed method.

  6. Control of Microbial Sulfide Production with Biocides and Nitrate in Oil Reservoir Simulating Bioreactors

    PubMed Central

    Xue, Yuan; Voordouw, Gerrit

    2015-01-01

    Oil reservoir souring by the microbial reduction of sulfate to sulfide is unwanted, because it enhances corrosion of metal infrastructure used for oil production and processing. Reservoir souring can be prevented or remediated by the injection of nitrate or biocides, although injection of biocides into reservoirs is not commonly done. Whether combined application of these agents may give synergistic reservoir souring control is unknown. In order to address this we have used up-flow sand-packed bioreactors injected with 2 mM sulfate and volatile fatty acids (VFA, 3 mM each of acetate, propionate and butyrate) at a flow rate of 3 or 6 pore volumes (PV) per day. Pulsed injection of the biocides glutaraldehyde (Glut), benzalkonium chloride (BAC) and cocodiamine was used to control souring. Souring control was determined as the recovery time (RT) needed to re-establish an aqueous sulfide concentration of 0.8–1 mM (of the 1.7–2 mM before the pulse). Pulses were either for a long time (120 h) at low concentration (long-low) or for a short time (1 h) at high concentration (short-high). The short-high strategy gave better souring control with Glut, whereas the long-low strategy was better with cocodiamine. Continuous injection of 2 mM nitrate alone was not effective, because 3 mM VFA can fully reduce both 2 mM nitrate to nitrite and N2 and, subsequently, 2 mM sulfate to sulfide. No synergy was observed for short-high pulsed biocides and continuously injected nitrate. However, use of continuous nitrate and long-low pulsed biocide gave synergistic souring control with BAC and Glut, as indicated by increased RTs in the presence, as compared to the absence of nitrate. Increased production of nitrite, which increases the effectiveness of souring control by biocides, is the most likely cause for this synergy. PMID:26696994

  7. Anthropogenic impact on flood-risk: a large-scale assessment for planning controlled inundation strategies along the River Po

    NASA Astrophysics Data System (ADS)

    Domeneghetti, Alessio; Castellarin, Attilio; Brath, Armando

    2013-04-01

    The European Flood Directive (2007/60/EC) has fostered the development of innovative and sustainable approaches and methodologies for flood-risk mitigation and management. Furthermore, concerning flood-risk mitigation, the increasing awareness of how the anthropogenic pressures (e.g. demographic and land-use dynamics, uncontrolled urban and industrial expansion on flood-prone area) could strongly increase potential flood damages and losses has triggered a paradigm shift from "defending the territory against flooding" (e.g. by means of levee system strengthening and heightening) to "living with floods" (e.g. promoting compatible land-uses or adopting controlled flooding strategies of areas located outside the main embankments). The assessment of how socio-economic dynamics may influence flood-risk represents a fundamental skill that should be considered for planning a sustainable industrial and urban development of flood-prone areas, reducing their vulnerability and therefore minimizing socio-economic and ecological losses due to large flood events. These aspects, which are of fundamental importance for Institutions and public bodies in charge of Flood Directive requirements, need to be considered through a holistic approach at river basin scale. This study focuses on the evaluation of large-scale flood-risk mitigation strategies for the middle-lower reach of River Po (~350km), the longest Italian river and the largest in terms of streamflow. Due to the social and economical importance of the Po River floodplain (almost 40% of the total national gross product results from this area), our study aims at investigating the potential of combining simplified vulnerability indices with a quasi-2D model for the definition of sustainable and robust flood-risk mitigation strategies. Referring to past (1954) and recent (2006) land-use data sets (e.g. CORINE) we propose simplified vulnerability indices for assessing potential flood-risk of industrial and urbanized flood prone

  8. Reliable conjunctive use rules for sustainable irrigated agriculture and reservoir spill control

    NASA Astrophysics Data System (ADS)

    Schoups, Gerrit; Addams, C. Lee; Minjares, Jose Luis; Gorelick, Steven M.

    2006-12-01

    We develop optimal conjunctive use water management strategies that balance two potentially conflicting objectives: sustaining irrigated agriculture during droughts and minimizing unnecessary spills and resulting water losses from the reservoir during wet periods. Conjunctive use is specified by a linear operating rule, which determines the maximum surface water release as a function of initial reservoir storage. Optimal strategies are identified using multiobjective interannual optimization for sustainability and spill control, combined with gradient-based annual profit maximization. Application to historical conditions in the irrigated system of the Yaqui Valley, Mexico, yields a Pareto curve of solutions illustrating the trade-off between sustaining agriculture and minimizing spills and water losses. Minimal water losses are obtained by maximizing surface water use and limiting groundwater pumping, such that reservoir levels are kept sufficiently low. Maximum agricultural sustainability, on the other hand, results from increased groundwater use and keeping surface water reservoir levels high during wet periods. Selected optimal operating rules from the multiobjective optimization are tested over a large number of equally probable streamflow time series, generated with a stochastic time series model. In this manner, statistical properties, such as the mean sustainability and sustainability percentiles, are determined for each optimal rule. These statistical properties can be used to select rules for water management that are reliable over a wide range of streamflow conditions.

  9. THE YALOBUSHA RIVER - GRENADA RESERVOIR WATERSHED: SEDIMENT MOVEMENT, ACCUMULATION AND QUALITY IN A MISSISSIPPI INTENSIVE AGRICULTURAL LANDSCAPE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined sedimentation rates, watershed contamination contributions and potential impacts of row cropping (cotton, corn, soybeans, and sweet potato) on a small river and a large downstream flood control reservoir in the loess hills of Mississippi, USA. Grenada Reservoir has a total watershed dra...

  10. Synopsis of integrated science to support the assessment of conservation practices in the Fort Cobb reservoir watershed, southwestern Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Fort Cobb Reservoir in southwestern Oklahoma is an artificial impoundment constructed by the Bureau of Reclamation for water supplies, flood control, and recreation. Success of best-management practices in reducing inflows of sediments and phosphorus to the reservoir prompted the U.S. Departmen...

  11. Assessing and improving steam-assisted gravity drainage: Reservoir heterogeneities, hydraulic fractures, and mobility control foams

    NASA Astrophysics Data System (ADS)

    Chen, Qing

    Steam-assisted gravity drainage (SAGD) is a promising approach for recovering heavy and viscous oil resources. In SAGD, two closely-spaced horizontal wells, one above the other, form a steam-injector and producer pair. The reservoir oil is heated by the injected steam and drains to the producer under the effect of gravity. The success of steam-assisted gravity drainage has been demonstrated by both field and laboratory studies mostly based on homogeneous reservoirs and reservoir models. A comprehensive understanding of the effects of reservoir heterogeneities on SAGD performance, however, is required for wider and more successful implementation. This dissertation presents an investigation of the effects of reservoir heterogeneities on SAGD. In addition, two potential methods, hydraulic fracturing and mobility control using foamed steam, are proposed and reported here to enhance SAGD performance, especially for heterogeneous reservoirs. Reservoir simulations of SAGD are conducted with a number of realizations of Athabasca-type oilsand reservoirs that contain randomly-distributed shales geostatistically generated with a stochastic model. We interpret the complex effects of reservoir heterogeneities by identifying two flow regions, the near well region (NWR) and the above well region (AWR). Our simulations indicate that the drainage flow of hot fluids within the NWR, characterized by short flow length, is very sensitive to the presence of shale, whereas the expansion of the steam chamber in the AWR, characterized by long flow length, is affected adversely only when the AWR contains long, continuous shale or a high fraction of shale. Vertical hydraulic fractures are found to improve steam chamber development considerably for reservoirs with poor vertical communication. For the synthetic reservoir under study, an increase in the oil production rate by a factor of two and considerable improvement of energy efficiency with the cumulative oil-steam ratio lifted from 0.2 to

  12. Design and implementation of a CO{sub 2} flood utilizing advanced reservoir characterization and horizontal injection wells in a shallow shelf carbonate approaching waterflood depletion. Annual report, June 3, 1994--October 31, 1995

    SciTech Connect

    Hallenbeck, L.D.; Harpole, K.J.; Gerard, M.G.

    1996-05-01

    The work reported here covers Budget Phase I of the project. The principal tasks in Budget Phase I are the Reservoir Analysis and Characterization Task and the Advanced Technology Definition Task. Completion of these tasks have enabled an optimum carbon dioxide (CO{sub 2}) flood project to be designed and evaluated from an economic and risk analysis standpoint. Field implementation of the project has been recommended to the working interest owner of the South Cowden Unit (SCU) and approval has been obtained. The current project has focused on reducing initial investment cost by utilizing horizontal injection wells and concentrating the project in the best productivity area of the field. An innovative CO{sub 2} purchase agreement (no take or pay requirements, CO{sub 2} purchase price tied to West Texas Intermediate crude oil price) and gas recycle agreements (expensing cost as opposed to large capital investments for compression) were negotiated to further improve project economics. A detailed reservoir characterization study was completed by an integrated team of geoscientists and engineers. The study consisted of detailed core description, integration of log response to core descriptions, mapping of the major flow units, evaluation of porosity and permeability relationships, geostatistical analysis of permeability trends, and direct integration of reservoir performance with the geological interpretation. The study methodology fostered iterative bidirectional feedback between the reservoir characterization team and the reservoir engineering/simulation team to allow simultaneous refinement and convergence of the geological interpretation with the reservoir model. The fundamental conclusion from the study is that South Cowden exhibits favorable enhanced oil recovery characteristics, particularly reservoir quality and continuity.

  13. Tectonic controls on fault-zone permeability in a geothermal reservoir at Dixie Valley, Nevada

    USGS Publications Warehouse

    Hickman, Stephen; Zoback, Mark; Benoit, Richard

    1998-01-01

    To determine factors controlling permeability variations within and adjacent to a fault-hosted geothermal reservoir at Dixie Valley, Nevada, we conducted borehole televiewer observations of wellbore failure (breakouts and cooling cracks) together with hydraulic fracturing stress measurements in six wells drilled into the Stillwater fault zone at depths of 2 to 3 km. Measurements in highly permeable wells penetrating the main geothermal reservoir indicate that the local orientation of the least horizontal principal stress, Shmin, is nearly optimal for normal faulting on the Stillwater fault. Hydraulic fracturing tests from these wells further show that the magnitude of Shmin is low enough to lead to frictional failure on the Stillwater and nearby subparallel faults, suggesting that fault slip is responsible for the high reservoir productivity. Similar measurements were conducted in two wells penetrating a relatively impermeable segment of the Stillwater fault zone, located approx. 8 and 20 km southwest of the geothermal reservoir (wells 66-21 and 45-14, respectively). The orientation of Shmin in well 66-21 is near optimal for normal faulting on the nearby Stillwater fault, but the magnitude of Shmin is too high to result in incipient frictional failure. In contrast, although the magnitude of Shmin in well 45-14 is low enough to lead to normal faulting on optimally oriented faults, the orientation of the Stillwater fault near this well is rotated by approx. 40?? from the optimal orientation for normal faulting. This misorientation, coupled with an apparent increase in the magnitude of the greatest horizontal principal stress in going from the producing to nonproducing wells, acts to inhibit frictional failure on the Stillwater fault zone in proximity to well 45-14. Taken together, data from the nonproducing and producing wells thus suggest that a necessary condition for high reservoir permeability is that the Stillwater fault zone be critically stressed for

  14. Model-controlled flooding with applications to image reconstruction and segmentation

    NASA Astrophysics Data System (ADS)

    Wang, Quanli; West, Mike

    2012-04-01

    We discuss improved image reconstruction and segmentation in a framework we term model-controlled flooding (MCF). This extends the watershed transform for segmentation by allowing the integration of a priori information about image objects into flooding simulation processes. Modeling the initial seeding, region growing, and stopping rules of the watershed flooding process allows users to customize the simulation with user-defined or default model functions incorporating prior information. It also extends a more general class of transforms based on connected attribute filters by allowing the modification of connected components of a grayscale image, thus providing more flexibility in image reconstruction. MCF reconstruction defines images with desirable features for further segmentation using existing methods and can lead to substantial improvements. We demonstrate the MCF framework using a size transform that extends grayscale area opening and attribute thickening/thinning, and give examples from several areas: concealed object detection, speckle counting in biological single cell studies, and analyses of benchmark microscopic image data sets. MCF achieves benchmark error rates well below those reported in the recent literature and in comparison with other algorithms, while being easily adapted to new imaging contexts.

  15. Salt marsh-atmosphere exchange of energy, water vapor, and carbon dioxide: Effects of tidal flooding and biophysical controls

    NASA Astrophysics Data System (ADS)

    Moffett, Kevan B.; Wolf, Adam; Berry, Joe A.; Gorelick, Steven M.

    2010-10-01

    The degree to which short-duration, transient floods modify wetland-atmosphere exchange of energy, water vapor, and carbon dioxide (CO2) is poorly documented despite the significance of flooding in many wetlands. This study explored the effects of transient floods on salt marsh-atmosphere linkages. Eddy flux, micrometeorological, and other field data collected during two tidal phases (daytime versus nighttime high tides) quantified the salt marsh radiation budget, surface energy balance, and CO2 flux. Analysis contrasted flooded and nonflooded and day and night effects. The salt marsh surface energy balance was similar to that of a heating-dominated sparse crop during nonflooded periods but similar to that of an evaporative cooling-dominated, well-watered grassy lawn during flooding. Observed increases in latent heat flux and decreases in net ecosystem exchange during flooding were proportional to flood depth and duration, with complete CO2 flux suppression occurring above some flood height less than the canopy height. Flood-induced changes in the salt marsh energy balance were dominated by changes in sensible heat flux, soil heat flux, and surface water heat storage. Parameters suitable for predicting the salt marsh surface energy balance were obtained by calibrating common models (e.g., Penman-Monteith, Priestley-Taylor, and pan coefficient). Biophysical controls on salt marsh-atmosphere exchange were identified following calibration of models describing the coupling of canopy photosynthesis and stomatal conductance in the salt marsh. The effects of flooding on salt marsh-atmosphere exchange are temporary but strongly affect the marsh water, carbon, and energy balance despite their short duration.

  16. Strategies to diagnose and control microbial souring in natural gas storage reservoirs and produced water systems

    SciTech Connect

    Morris, E.A.; Derr, R.M.; Pope, D.H.

    1995-12-31

    Hydrogen sulfide production (souring) in natural gas storage reservoirs and produced water systems is a safety and environmental problem that can lead to operational shutdown when local hydrogen sulfide standards are exceeded. Systems affected by microbial souring have historically been treated using biocides that target the general microbial community. However, requirements for more environmentally friendly solutions have led to treatment strategies in which sulfide production can be controlled with minimal impact to the system and environment. Some of these strategies are based on microbial and/or nutritional augmentation of the sour environment. Through research sponsored by the Gas Research Institute (GRI) in Chicago, Illinois, methods have been developed for early detection of microbial souring in natural gas storage reservoirs, and a variety of mitigation strategies have been evaluated. The effectiveness of traditional biocide treatment in gas storage reservoirs was shown to depend heavily on the methods by which the chemical is applied. An innovative strategy using nitrate was tested and proved ideal for produced water and wastewater systems. Another strategy using elemental iodine was effective for sulfide control in evaporation ponds and is currently being tested in microbially sour natural gas storage wells.

  17. Inland Flood Hazards

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen E.

    2000-07-01

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

  18. Development of a model-based flood emergency management system in Yujiang River Basin, South China

    NASA Astrophysics Data System (ADS)

    Zeng, Yong; Cai, Yanpeng; Jia, Peng; Mao, Jiansu

    2014-06-01

    Flooding is the most frequent disaster in China. It affects people's lives and properties, causing considerable economic loss. Flood forecast and operation of reservoirs are important in flood emergency management. Although great progress has been achieved in flood forecast and reservoir operation through using computer, network technology, and geographic information system technology in China, the prediction accuracy of models are not satisfactory due to the unavailability of real-time monitoring data. Also, real-time flood control scenario analysis is not effective in many regions and can seldom provide online decision support function. In this research, a decision support system for real-time flood forecasting in Yujiang River Basin, South China (DSS-YRB) is introduced in this paper. This system is based on hydrological and hydraulic mathematical models. The conceptual framework and detailed components of the proposed DSS-YRB is illustrated, which employs real-time rainfall data conversion, model-driven hydrologic forecasting, model calibration, data assimilation methods, and reservoir operational scenario analysis. Multi-tiered architecture offers great flexibility, portability, reusability, and reliability. The applied case study results show the development and application of a decision support system for real-time flood forecasting and operation is beneficial for flood control.

  19. Controls on reservoir development in a shelf carbonate: Upper Jurassic smackover formation of Alabama

    SciTech Connect

    Kopaska-Merkel, D.C.; Mann, S.D.; Schmoker, J.W.

    1994-06-01

    Hydrocarbon reservoirs of the Upper Jurassic Smackover Formation in Alabama are predominately oolitic and pelletal dolostone. Pore systems are dominated by moldic and secondary intraparticle pores, intercrystalline pores, or mixtures of these pore types. All Smackover reservoirs in Alabama have been strongly affected by early cementation, dissolution of calcium-carbonate allochems, and dolomitization. Dolomitization of the Smackover in Alabama included penecontemporaneous, early burial, and late (deep) burial episodes. Fabric-selective dolomitization yielded reservoirs strongly influenced by both depositional fabric and diagenesis. Nonselective dolomitization yielded reservoirs with intercrystalline pore systems shaped primarily by diagenesis. Thermal exposure is inversely related to porosity, but the relationship is weak (r{sup 2} < 0.5). Fabric-selective dolostone is slightly more porous than nonselective dolostone when averaged over the entire study area (averages of 18.1% and 15.1%, respectively; p = 0.0001), but nonselective dolostone is more porous at a given level of equivalent vitrinite reflectance. Smackover fields on the north flank of the Wiggins arch are unusually porous given their level of thermal maturity, and are unusual in other ways as well. Local porosity variation was controlled by depositional fabric, early cementation, dissolution, and burial compaction and cementation. Regional permeability variation cannot be explained using existing data. Permeability is locally controlled by pore-throat size, the effects of dolomite crystal-size distribution, early cementation, fracturing, and burial compaction and cementation. Pore-throat size exhibits the strongest overall correlation with permeability (r{sup 2} = 0.54). Permeability and porosity are strongly correlated locally, but the regional correlation is weak.

  20. Quantification of Libby Reservoir Levels Needed to Maintain or Enhance Reservoir Fisheries, 1983-1987 Methods and Data Summary.

    SciTech Connect

    Chisholm, Ian

    1989-12-01

    Libby Reservoir was created under an International Columbia River Treaty between the United States and Canada for cooperative water development of the Columbia River Basin. The authorized purpose of the dam is to provide power, flood control, and navigation and other benefits. Research began in May 1983 to determine how operations of Libby dam impact the reservoir fishery and to suggest ways to lessen these impacts. This study is unique in that it was designed to accomplish its goal through detailed information gathering on every trophic level in the reservoir system and integration of this information into a quantitative computer model. The specific study objectives are to: quantify available reservoir habitat, determine abundance, growth and distribution of fish within the reservoir and potential recruitment of salmonids from Libby Reservoir tributaries within the United States, determine abundance and availability of food organisms for fish in the reservoir, quantify fish use of available food items, develop relationships between reservoir drawdown and reservoir habitat for fish and fish food organisms, and estimate impacts of reservoir operation on the reservoir fishery. 115 refs., 22 figs., 51 tabs.

  1. Processes occurring in reservoirs receiving biogenic and polluting substances

    SciTech Connect

    Vasil'ev, Yu.S.; Rolle, N.N.

    1988-04-01

    Various aspects of biogenic pollution on the water quality of reservoirs and its effect on ichthyofauna were analyzed. The effects of fertilizer runoffs and other pollutant pathways, such as the decay of flooded vegetation, into reservoirs were addressed. The dependence of fish survival times on nitrite concentrations was charted. On the basis of an optimization model for the economic development of drainage basins with ecological limitations, the Leningrad Polytechnic Institute developed instructions for calculating the removal of biogenic elements and selecting water protection measures which were tested on a number of streams of the Lake Ladoga Basin and other areas and which provide engineering means for evaluating and controlling the eutrophication of reservoirs.

  2. Problems related to water quality and algal control in Lopez Reservoir, San Luis Obispo County, California

    USGS Publications Warehouse

    Fuller, Richard H.; Averett, Robert C.; Hines, Walter G.

    1975-01-01

    A study to determine the present enrichment status of Liopez Reservoir in San Luis Obispo county, California, and to evaluate copper sulfate algal treatment found that stratification in the reservoir regulates nutrient release and that algal control has been ineffective. Nuisance algal blooms, particularly from March to June, have been a problem in the warm multipurpose reservoir since it was initially filled following intense storms in 1968-69. The cyanophyte Anabaena unispora has been dominant; cospecies are the diatoms Stephanodiscus astraea and Cyclotella operculata, and the chlorophytes Pediastrum deplex and Sphaerocystis schroeteri. During an A. unispora bloom in May 1972 the total lake surface cell count was nearly 100,000 cells/ml. Thermal stratification from late spring through autumn results in oxygen deficiency in the hypolimnion and metalimnion caused by bacterial oxidation of organic detritus. The anaerobic conditions favor chemical reduction of organic matter, which constitute 10-14% of the sediment. As algae die, sink to the bottom, and decompose, nutrients are released to the hypolimnion , and with the autumn overturn are spread to the epilimnion. Algal blooms not only hamper recreation, but through depletion of dissolved oxygen in the epilimnion may have caused periodic fishkills. Copper sulfate mixed with sodium citrate and applied at 1.10-1.73 lbs/acre has not significantly reduced algal growth; a method for determining correct dosage is presented. (Lynch-Wisconsin)

  3. Tectonic control of the crustal organic carbon reservoir during the Precambrian

    NASA Technical Reports Server (NTRS)

    Des Marais, D. J.

    1994-01-01

    Carbon isotopic trends indicate that the crustal reservoir of reduced, organic carbon increased during the Proterozoic, particularly during periods of widespread continental rifting and orogeny. No long-term trends are apparent in the concentration of organic carbon in shales, cherts and carbonates. The age distribution of 261 sample site localities sampled for well-preserved sedimentary rocks revealed a 500-700-Ma periodicity which coincided with tectonic cycles. It is assumed that the numbers of sites are a proxy for mass of sediments. A substantial increase in the number of sites in the late Archean correlates with the first appearance between 2.9 and 2.5 Ga of extensive continental platforms and their associated sedimentation. It is proposed that the size of the Proterozoic crustal organic carbon reservoir has been modulated by tectonic control of the volume of sediments deposited in environments favorable for the burial and preservation of organic matter. Stepwise increases in this reservoir would have caused the oxidation state of the Proterozoic environment to increase in a stepwise fashion.

  4. Flow structures and sandbar dynamics in a canyon river during a controlled flood, Colorado River, Arizona

    USGS Publications Warehouse

    Wright, S.A.; Kaplinski, M.

    2011-01-01

    In canyon rivers, debris fan constrictions create rapids and downstream pools characterized by secondary flow structures that are closely linked to channel morphology. In this paper we describe detailed measurements of the three-dimensional flow structure and sandbar dynamics of two pools along the Colorado River in the Grand Canyon during a controlled flood release from Glen Canyon Dam. Results indicate that the pools are characterized by large lateral recirculation zones (eddies) resulting from flow separation downstream from the channel constrictions, as well as helical flow structures in the main channel and eddy. The lateral recirculation zones are low-velocity areas conducive to fine sediment deposition, particularly in the vicinity of the separation and reattachment points and are thus the dominant flow structures controlling sandbar dynamics. The helical flow structures also affect morphology but appear secondary in importance to the lateral eddies. During the controlled flood, sandbars in the separation and reattachment zones at both sites tended to build gradually during the rising limb and peak flow. Deposition in shallow water on the sandbars was accompanied by erosion in deeper water along the sandbar slope at the interface with the main channel. Erosion occurred via rapid mass failures as well as by gradual boundary shear stress driven processes. The flow structures and morphologic links at our study sites are similar to those identified in other river environments, in particular sharply curved meanders and channel confluences where the coexistence of lateral recirculation and helical flows has been documented. Copyright 2011 by the American Geophysical Union.

  5. Diagnostic Assessment of the Difficulty Using Direct Policy Search in Many-Objective Reservoir Control

    NASA Astrophysics Data System (ADS)

    Zatarain-Salazar, J.; Reed, P. M.; Herman, J. D.; Giuliani, M.; Castelletti, A.

    2014-12-01

    Globally reservoir operations provide fundamental services to water supply, energy generation, recreation, and ecosystems. The pressures of expanding populations, climate change, and increased energy demands are motivating a significant investment in re-operationalizing existing reservoirs or defining operations for new reservoirs. Recent work has highlighted the potential benefits of exploiting recent advances in many-objective optimization and direct policy search (DPS) to aid in addressing these systems' multi-sector demand tradeoffs. This study contributes to a comprehensive diagnostic assessment of multi-objective evolutionary optimization algorithms (MOEAs) efficiency, effectiveness, reliability, and controllability when supporting DPS for the Conowingo dam in the Lower Susquehanna River Basin. The Lower Susquehanna River is an interstate water body that has been subject to intensive water management efforts due to the system's competing demands from urban water supply, atomic power plant cooling, hydropower production, and federally regulated environmental flows. Seven benchmark and state-of-the-art MOEAs are tested on deterministic and stochastic instances of the Susquehanna test case. In the deterministic formulation, the operating objectives are evaluated over the historical realization of the hydroclimatic variables (i.e., inflows and evaporation rates). In the stochastic formulation, the same objectives are instead evaluated over an ensemble of stochastic inflows and evaporation rates realizations. The algorithms are evaluated in their ability to support DPS in discovering reservoir operations that compose the tradeoffs for six multi-sector performance objectives with thirty-two decision variables. Our diagnostic results highlight that many-objective DPS is very challenging for modern MOEAs and that epsilon dominance is critical for attaining high levels of performance. Epsilon dominance algorithms epsilon-MOEA, epsilon-NSGAII and the auto adaptive Borg

  6. Reservoir performance under uncertainty in hydrologic impacts of climate change

    NASA Astrophysics Data System (ADS)

    Raje, Deepashree; Mujumdar, P. P.

    2010-03-01

    Relatively few studies have addressed water management and adaptation measures in the face of changing water balances due to climate change. The current work studies climate change impact on a multipurpose reservoir performance and derives adaptive policies for possible future scenarios. The method developed in this work is illustrated with a case study of Hirakud reservoir on the Mahanadi river in Orissa, India, which is a multipurpose reservoir serving flood control, irrigation and power generation. Climate change effects on annual hydropower generation and four performance indices (reliability with respect to three reservoir functions, viz. hydropower, irrigation and flood control, resiliency, vulnerability and deficit ratio with respect to hydropower) are studied. Outputs from three general circulation models (GCMs) for three scenarios each are downscaled to monsoon streamflow in the Mahanadi river for two future time slices, 2045-65 and 2075-95. Increased irrigation demands, rule curves dictated by increased need for flood storage and downscaled projections of streamflow from the ensemble of GCMs and scenarios are used for projecting future hydrologic scenarios. It is seen that hydropower generation and reliability with respect to hydropower and irrigation are likely to show a decrease in future in most scenarios, whereas the deficit ratio and vulnerability are likely to increase as a result of climate change if the standard operating policy (SOP) using current rule curves for flood protection is employed. An optimal monthly operating policy is then derived using stochastic dynamic programming (SDP) as an adaptive policy for mitigating impacts of climate change on reservoir operation. The objective of this policy is to maximize reliabilities with respect to multiple reservoir functions of hydropower, irrigation and flood control. In variations to this adaptive policy, increasingly more weightage is given to the purpose of maximizing reliability with respect to

  7. Loop Heat Pipe Transient Behavior Using Heat Source Temperature for Set Point Control with Thermoelectric Converter on Reservoir

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly done by cold biasing the reservoir and using electrical heaters to provide the required control power. With this method, the loop operating temperature can be controlled within 0.5K or better. However, because the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if the LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP was carried out to investigate the effects on the LHP operation when the control temperature sensor was placed on the heat source instead of the reservoir. In these tests, the LHP reservoir was cold-biased and was heated by a control heater. Test results show that it was feasible to use the heat source temperature for feedback control of the LHP operation. In particular, when a thermoelectric converter was used as the reservoir control heater, the heat source temperature could be maintained within a tight range using a proportional-integral-derivative or on/off control algorithm. Moreover, because the TEC could provide both heating and cooling to the reservoir, temperature oscillations during fast transients such as loop startup could be eliminated or substantially reduced when compared to using an electrical heater as the control heater.

  8. Operational water management of Rijnland water system and pilot of ensemble forecasting system for flood control

    NASA Astrophysics Data System (ADS)

    van der Zwan, Rene

    2013-04-01

    The Rijnland water system is situated in the western part of the Netherlands, and is a low-lying area of which 90% is below sea-level. The area covers 1,100 square kilometres, where 1.3 million people live, work, travel and enjoy leisure. The District Water Control Board of Rijnland is responsible for flood defence, water quantity and quality management. This includes design and maintenance of flood defence structures, control of regulating structures for an adequate water level management, and waste water treatment. For water quantity management Rijnland uses, besides an online monitoring network for collecting water level and precipitation data, a real time control decision support system. This decision support system consists of deterministic hydro-meteorological forecasts with a 24-hr forecast horizon, coupled with a control module that provides optimal operation schedules for the storage basin pumping stations. The uncertainty of the rainfall forecast is not forwarded in the hydrological prediction. At this moment 65% of the pumping capacity of the storage basin pumping stations can be automatically controlled by the decision control system. Within 5 years, after renovation of two other pumping stations, the total capacity of 200 m3/s will be automatically controlled. In critical conditions there is a need of both a longer forecast horizon and a probabilistic forecast. Therefore ensemble precipitation forecasts of the ECMWF are already consulted off-line during dry-spells, and Rijnland is running a pilot operational system providing 10-day water level ensemble forecasts. The use of EPS during dry-spells and the findings of the pilot will be presented. Challenges and next steps towards on-line implementation of ensemble forecasts for risk-based operational management of the Rijnland water system will be discussed. An important element in that discussion is the question: will policy and decision makers, operator and citizens adapt this Anticipatory Water

  9. Characterizing regulated reservoirs dynamics in regional to global scale hydrologic models

    NASA Astrophysics Data System (ADS)

    Beighley, E.; Yoon, Y.; Lee, H.; Pavelsky, T.; Allen, G. H.

    2015-12-01

    Lakes and reservoirs are widely used for water supply and flood control resulting in regulated release of outflows that are nonconcurrent with inflows. In hydrologic modeling applications, accounting for the regulated behavior of reservoirs distributed throughout a river system poses a significant challenge because detailed reservoir operation rules or strategies can be difficult or not possible to obtain. Building on this problem, this study addresses the science questions: Can we model reservoir water storage changes and outlet discharges based on satellite measurements of river water surface elevation and inundated area, and How does repeat cycle, mission duration and measurement uncertainty impact our ability to characterize reservoir behavior? A modeling framework suitable for regional to global applications and based on the forthcoming Surface Water and Ocean Topography (SWOT) satellite mission is presented. Although our framework can be combined with data assimilation techniques for real-time flood forecasting, our goal is to represent reservoir storage patterns in large-scale hydrologic models for simulating: (i) impacts of future climate and/or land cover conditions on water resources, and (ii) synthetic storm events (e.g., 100-yr flood) or event catalogs for flood hazard and risk assessments. In-situ and remotely sensed reservoir dynamics are presented for select locations in the Mississippi River Basin and used in the Hillslope River Routing (HRR) hydrologic model to simulate downstream flow dynamics.

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

    SciTech Connect

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

    2010-12-16

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

  11. A case-control comparison of durability and cost between implanted reservoir and percutaneous catheters in cancer patients.

    PubMed

    McCready, D; Broadwater, R; Ross, M; Pollock, R; Ota, D; Balch, C

    1991-11-01

    A case-control study was performed to compare the durability and cost of implanted reservoir catheter systems with percutaneous central venous catheters. Twenty cancer patients had reservoir systems placed in 1985 for chemotherapy delivery. The control group consisted of 60 cancer patients, matched according to age, sex, and diagnosis who were part of a group of more than 700 patients with percutaneous catheters inserted during the same period. The reservoir catheters were found to function for a significantly (P less than 0.0001) longer time (495 +/- 54 days) compared to the percutaneous catheters (197 +/- 22 days). The total cost for each system was calculated by adding the charges for an average insertion (reservoir = $1738, percutaneous = $562) to the maintenance charges accumulated over the catheters' lifespan. Reservoir catheters were associated with a significantly greater total cost than percutaneous catheters ($2233 +/- 54, $1453 +/- 102, respectively) but, if the total cost was spread out over the lifespan of the catheter by dividing the total cost by duration of use, reservoir catheters can be less expensive on a per diem basis. The break point occurs at approximately 6 months. For use less than 6 months, percutaneous catheters are cheaper primarily because of their lower insertion costs, but, for longer periods, reservoir catheters become cheaper because of lower maintenance costs and because a second percutaneous catheterization would likely be necessary. PMID:1758171

  12. Quality of surface water before implementation of a flood-control project in Chaska, Minnesota

    USGS Publications Warehouse

    Tornes, L.H.

    1981-01-01

    Samples were collected for 1 year from East Creek, Chaska Creek, and Courthouse Lake in Chaska, Minnesota, to determine the water quality before implementation of a flood-control project proposed by the U.S. Army Corps of Engineers. The creeks had similar water-quality characteristics. Data indicate that ground water may be the primary source of dissolved solids, sulfate, chloride, and chromium in the creeks. The pesticides alachlor, atrazine, simazine, and 2,4-D were found in water samples from both creeks but were well below the lethal concentrations for fish. Courthouse Lake, a 57-foot-deep stream-trout lake, had a mean summer trophic-state index of 35. Phytoplankton populations varied seasonally, and blue-green algae were predominant only in late summer. The algal-pollution index was highest in late summer, but did not provide evidence of high organic pollution. The apparently successful recovery of Courthouse Lake from past inundations by Minnesota River floodwaters having total phosphorus concentrations as high as 0.66 milligram per liter suggests that the lake, in time, will also recover from the added runoff expected as a result of implementing the flood-control project. The runoff could temporarily raise the total phosphorus concentration in the lake from 0.03 to 0.12 milligram per liter and raise the spring trophic-state index from 49 to 69.

  13. 75 FR 18238 - United States Section; Final Environmental Impact Statement, Flood Control Improvements and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-09

    ..., overtopping, piping/sand boils, under-seepage, and severe surface and slope erosion. The flooding also... existing levee during the September 2008 flooding (including severe erosion, levee breaches, and...

  14. Environmental Effects of Storage Preservation Practices: Controlled Flushing of Fine Sediment from a Small Hydropower Reservoir

    NASA Astrophysics Data System (ADS)

    Espa, Paolo; Castelli, Elena; Crosa, Giuseppe; Gentili, Gaetano

    2013-07-01

    Sediment flushing may be effective in mitigating loss of reservoir storage due to siltation, but flushing must be controlled to limit the impact on the downstream environment. A reliable prediction of the environmental effects of sediment flushing is hindered by the limited scientific information currently available. Consequently, there may be some controversy as regards to management decisions, planning the work, and monitoring strategies. This paper summarizes the main results of a monitoring campaign on the stream below a small alpine hydropower reservoir subjected to annual flushing between 2006 and 2009. The removed sediment was essentially silt, and the suspended solid concentration (SSC) of the discharged water was controlled to alleviate downstream impact. Control was achieved through hydraulic regulation and mechanical digging, alternating daytime sediment evacuation, and nocturnal clear water release. The four operations lasted about two weeks each and had an average SSC of about 4 g L-1. Maximum values of SSC were generally kept below 10 g L-1. Downstream impact was quantified through sampling of fish fauna (brown trout) and macroinvertebrate in the final reach of the effluent stream. The benthic community was severely impaired by the flushing operations, but recovered to pre-flushing values in a few months. As expected, the impact on brown trout was heavier on juveniles. While data biasing due to fish removal and re-stocking cannot be ruled out, the fish community seems to have reached a state of equilibrium characterized by a lower density than was measured before the flushing operations.

  15. Wildlife reservoirs of bovine tuberculosis worldwide: hosts, pathology, surveillance, and control.

    PubMed

    Fitzgerald, S D; Kaneene, J B

    2013-05-01

    Bovine tuberculosis due to Mycobacterium bovis is a zoonotic disease classically carried by cattle and spilling over into humans primarily by the ingestion of milk. However, in recent decades, there have been many endemic geographic localities where M. bovis has been detected infecting wildlife reservoirs, limiting the progress toward eradication of this disease from cattle. These include cervids in North America, badgers in Great Britain, feral pigs in Europe, brushtailed possums in New Zealand, and buffalo in South Africa. An overview of these wildlife hosts will provide insight into how these reservoirs maintain and spread the disease. In addition, the authors summarize the pathology, current ongoing methods for surveillance, and control. In many instances, it has proven to be more difficult to control or eradicate bovine tuberculosis in wild free-ranging species than in domesticated cattle. Furthermore, human influences have often contributed to the introduction and/or maintenance of the disease in wildlife species. Finally, some emerging themes regarding bovine tuberculosis establishment in wildlife hosts, as well as conclusions regarding management practices to assist in bovine tuberculosis control and eradication in wildlife, are offered. PMID:23169912

  16. Evaluating changes to reservoir rule curves using historical water-level data

    USGS Publications Warehouse

    Mower, Ethan; Miranda, Leandro E.

    2013-01-01

    Flood control reservoirs are typically managed through rule curves (i.e. target water levels) which control the storage and release timing of flood waters. Changes to rule curves are often contemplated and requested by various user groups and management agencies with no information available about the actual flood risk of such requests. Methods of estimating flood risk in reservoirs are not easily available to those unfamiliar with hydrological models that track water movement through a river basin. We developed a quantile regression model that uses readily available daily water-level data to estimate risk of spilling. Our model provided a relatively simple process for estimating the maximum applicable water level under a specific flood risk for any day of the year. This water level represents an upper-limit umbrella under which water levels can be operated in a variety of ways. Our model allows the visualization of water-level management under a user-specified flood risk and provides a framework for incorporating the effect of a changing environment on water-level management in reservoirs, but is not designed to replace existing hydrological models. The model can improve communication and collaboration among agencies responsible for managing natural resources dependent on reservoir water levels.

  17. Flow Focusing as a Control on the Width of Canyons Formed by Outburst Floods

    NASA Astrophysics Data System (ADS)

    Lapotre, M. G.; Lamb, M. P.; Halliday, C. K.

    2012-12-01

    Spectacular canyons exist on the surfaces of Earth and Mars that were carved by ancient outburst megafloods. These canyons often have steep headwalls and were eroded into jointed rock. This suggests that canyon formation is driven by upstream retreat of waterfalls through toppling failure. Discharge reconstructions remain difficult, however, because we do not understand quantitatively the links between canyon formation and canyon morphology. Here we propose that the width of canyon headwalls is set by the shear stress distribution around the rim of the canyon, which governs the propensity for toppling failure, and that this distribution is controlled by focusing of flood water into the canyon head. To test this hypothesis, we performed a series of numerical simulations of 2-D, depth-averaged, turbulent flow using the hydraulic numerical modeling suite ANUGA Hydro and mapped the shear stresses along the rim of canyons of various geometries. The numerical simulations were designed to explore three dimensionless variables: the aspect ratio of the canyon (length normalized by width), the canyon width relative to the normal flow depth, and the Froude number. Preliminary results show that flow focusing at the head of a canyon can lead to heightened shear stresses there compared to the sides of the canyon. Flow focusing is most efficient for subcritical flows with large canyon aspect ratios, suggesting that canyons grow in all directions until they reach a critical length which depends on the Froude number only. Canyons longer than this critical length maintain a uniform width during canyon formation. Earth-analog canyons, where flood depths were constrained from previous paleo-hydraulic studies, show good agreement with our numerical predictions, suggesting that flow focusing may set the width of canyons during megafloods. Model results allow a link between process and form that will enable us to constrain better flood discharges on Earth and Mars, where other robust

  18. Mobility control and scaleup for chemical flooding. Annual report, October 1981-September 1982

    SciTech Connect

    Pope, G.A.

    1984-11-01

    The ongoing objectives of this project are: (1) to determine quantitatively the effects of dispersion, relative permeabilities, apparent viscosity and inaccessible pore volume on micellar/polymer flooding, and (2) to develop numerical simulators which incorporate these and other features of the process, so that mobility control design and scaleup of the micellar/polymer flooding process can be better accomplished. Section 2 of this report includes the results for capillary desaturation experiments for low tension fluids in Berea. These results show that some residual brine remains during microemulsion flooding even at the highest capillary number obtained in this experiment. Section 2 also includes more extensive results from the dispersion and relative permeability experiments. This section also includes data which extends the dispersion and relative permeability results from the case of two-phase flow to include initial results of three-phase flow at steady state. Section 3 is a complete description of our updated simulator. Section 4 describes and gives the results of an oil recovery experiment. Section 5 compares the results of this oil recovery experiment with our simulator. The agreement is the best obtained so far. Section 6 compares our simulator with a Sloss experiment reported by Gupta. Again, the agreement is good and demonstrates the capability of the improved simulator to account for the separation of alcohol and surfactant. Section 7 contains the results of several 2-D areal simulations involving new features of the 2-D simulator reported last year. Section 8 is a list of some of the major conclusions of this simulation research. Section 9 is an SPE paper combining the results of Senol with Walsh, a Ph.D. student of Lake and Schechter. Her polymer experiments were interpreted using Walsh's geochemical simulator. 133 references, 118 figures, 21 tables.

  19. Frameworks for amending reservoir water management

    USGS Publications Warehouse

    Mower, Ethan; Miranda, Leandro E.

    2013-01-01

    Managing water storage and withdrawals in many reservoirs requires establishing seasonal targets for water levels (i.e., rule curves) that are influenced by regional precipitation and diverse water demands. Rule curves are established as an attempt to balance various water needs such as flood control, irrigation, and environmental benefits such as fish and wildlife management. The processes and challenges associated with amending rule curves to balance multiuse needs are complicated and mostly unfamiliar to non-US Army Corps of Engineers (USACE) natural resource managers and to the public. To inform natural resource managers and the public we describe the policies and process involved in amending rule curves in USACE reservoirs, including 3 frameworks: a general investigation, a continuing authority program, and the water control plan. Our review suggests that water management in reservoirs can be amended, but generally a multitude of constraints and competing demands must be addressed before such a change can be realized.

  20. Sequential CCR5-Tropic HIV-1 Reactivation from Distinct Cellular Reservoirs following Perturbation of Elite Control

    PubMed Central

    Watters, Sarah A.; Mlcochova, Petra; Maldarelli, Frank; Goonetilleke, Nilu; Pillay, Deenan; Gupta, Ravindra K.

    2016-01-01

    Background HIV Elite Controllers may reveal insights into virus persistence given they harbour small reservoir sizes, akin to HIV non-controllers treated early with combination antiretroviral therapy. Both groups of patients represent the most promising candidates for interventions aimed at sustained remission or ‘cure’. Analytic treatment interruption (ATI) in the latter group leads to stochastic rebound of virus, though it is unclear whether loss of elite control is also associated with similar rebound characteristics. Methods We studied three discrete periods of virus rebound during myeloma related immune disruption over 2.5 years in an elite controller who previously underwent autologous stem cell transplantation (ASCT) in the absence of any antiretroviral therapy. Single genome sequencing of the V1-V4 region of env in PBMC and plasma was performed and phylogenies reconstructed. Average pairwise distance (APD) was calculated and non-parametric methods used to assess compartmentalisation. Coreceptor usage was predicted based on genotypic algorithms. Results 122 single genome sequences were obtained (median 26 sequences per rebound). The initial rebounding plasma env sequences following ASCT represented two distinct lineages, and clustered with proviral DNA sequences isolated prior to ASCT. One of the lineages was monophyletic, possibly indicating reactivation from clonally expanded cells. The second rebound occurred 470 days after spontaneous control of the first rebound and was phylogenetically distinct from the first, confirmed by compartmentalisation analysis, with a different cellular origin rather than ongoing replication. By contrast, third rebound viruses clustered with second rebound viruses, with evidence for ongoing evolution that was associated with lymphopenia and myeloma progression. Following ASCT a shift in tropism from CXCR4-tropic viruses to a CCR5-tropic population was observed to persist through to the third rebound. Conclusions Our data

  1. Deriving joint optimal refill rules for cascade reservoirs with multi-objective evaluation

    NASA Astrophysics Data System (ADS)

    Zhou, Yanlai; Guo, Shenglian; Xu, Chong-Yu; Liu, Pan; Qin, Hui

    2015-05-01

    Reservoirs are one of the most efficient infrastructures for integrated water resources development and management; and play a more and more important role in flood control and conservation. Optimal refill operation before the end of flood season is a valuable and effective approach to compromise the flood control, hydropower generation and comprehensive utilization of water resources of river basins. An integrated model consisting of a flood control risk analysis module, a utilization benefits analysis module and a multi-objective evaluation module was proposed in this study to derive joint optimal refill rules for cascade reservoirs. The Jinsha River and Three Gorges cascade reservoirs in the Changjiang River basin of China are selected for a case study. Sixty-one years of observed daily runoff data from 1950 to 2010 have been used to test the model. The results indicate that the proposed model can make an effective tradeoff between flood control and utilization benefits. Joint optimal synchronous and asynchronous refill rules can generate 3.25% and 2.78% more annual average hydropower, respectively and improve the fullness storage rate without increasing flood control risk comparing with the original designed operating rules.

  2. Identification of physical parameters controlling the dominance of algal species in a subtropical reservoir.

    PubMed

    Chien, Y C; Wu, S C; Wu, J T

    2009-01-01

    Eutrophication is a serious problem of water resource management in Taiwan. The occurrence of annoying algal species as well as abnormally abundant algal mass threatens the quality of water supply. The growth and decline of a specific phytoplankton species are affected by environmental factors, including light, nutrients, temperature, etc. There have been many investigations on the effects of individual factors on the abundance and composition of algal populations. However, many analyses on the effects of environmental factors, especially the concentration of nutrients, on phytoplankton failed to identify the controlling factors on the dynamic change of the phytoplankton species. This study used statistical methods to isolate the effect of seasons on the phytoplankton growth and searched for the relationships between the nutrient concentrations and the abundance of different algal species in Feitsui Reservoir based on the data obtained from 1995 to 2003. We found that the dynamic change of dominance of some species of phytoplankton was strongly related to the seasonal factors. The controlling factors of the survival of an algal species were the settling and mobility of the phytoplankton, the mixing depth and the vertical mixing strength of the water bodies. According to our preliminary findings, the influence of physical factors, varying seasonally, outweighs the influence of nutrients on the algal species composition in Feitsui Reservoir in Taiwan. PMID:19809140

  3. Regional parent flood frequency distributions in Europe - Part 2: Climate and scale controls

    NASA Astrophysics Data System (ADS)

    Salinas, J. L.; Castellarin, A.; Kohnová, S.; Kjeldsen, T. R.

    2014-11-01

    This study aims to better understand the effect of catchment scale and climate on the statistical properties of regional flood frequency distributions. A database of L-moment ratios of annual maximum series (AMS) of peak discharges from Austria, Italy and Slovakia, involving a total of 813 catchments with more than 25 yr of record length is presented, together with mean annual precipitation (MAP) and basin area as catchment descriptors surrogates of climate and scale controls. A purely data-based investigation performed on the database shows that the generalized extreme value (GEV) distribution provides a better representation of the averaged sample L-moment ratios compared to the other distributions considered, for catchments with medium to higher values of MAP independently of catchment area, while the three-parameter lognormal distribution is probably a more appropriate choice for drier (lower MAP) intermediate-sized catchments, which presented higher skewness values. Sample L-moment ratios do not follow systematically any of the theoretical two-parameter distributions. In particular, the averaged values of L-coefficient of skewness (L-Cs) are always larger than Gumbel's fixed L-Cs. The results presented in this paper contribute to the progress in defining a set of "process-driven" pan-European flood frequency distributions and to assess possible effects of environmental change on its properties.

  4. Quantification of Libby Reservoir Water Levels Needed to Maintain or Enhance Reservoir Fisheries, 1983 Final Report.

    SciTech Connect

    Shepard, Bradley B.

    1984-07-01

    The first six months of the fishery investigations in Libby Reservoir were aimed at developing suitable methodology for sampling physical-chemical limnology, fish food availability, fish food habits, and seasonal distribution and abundance of fish populations. Appropriate methods have been developed for all aspects with minor modification of original proposed methodologies. Purse seining has yet to be tested. Physical-chemical limnologic sampling could be reduced or subcontracted with the U.S. Geologic Survey to allow for more intensive sampling of fish food or fish distribution portions of the investigation. Final sample design will be determined during 1983-84. Future directions of the study revolve around two central issues, the potential for flexibility in reservoir operation and determination of how reservoir operation affects fish populations. Simulated maximum drawdown levels during a 40-year period were controlled by power in seven out of eight years. Drawdowns were generally within 10 feet of the flood control rule curve, however. There may be more flexibility with regards to timing of refill and evacuation. This aspect needs to be evaluated further. Production and availability of fish food, suitability of reservoir habitat, and accessibility of off-reservoir spawning and rearing habitat were identified as components of fish ecology which reservoir operation could potentially impact. Two models based on trophic dynamics and habitat suitabilities were suggested as a framework for exploring the relationship of reservoir operation on the fish community.

  5. The August 2002 flood in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Sercl, P.; Stehlik, J.

    2003-04-01

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

  6. Controls of DSi in streams and reservoirs along the Kaveri River, South India.

    PubMed

    Meunier, J D; Riotte, J; Braun, J J; Sekhar, M; Chalié, F; Barboni, D; Saccone, L

    2015-01-01

    There is an increasing body of evidence showing that land use may affect the concentration and flux of dissolved silica (DSi) and amorphous, biogenic Si particles (ASi/BSi) in surface waters. Here, we present a study of riverine waters collected within the Kaveri River Basin, which has a long history of land occupation with +43% population increase in the watershed during the last 30 years associated with agricultural practices including canal irrigation from reservoirs and, more recently, bore well pumping. We report total dissolved solids (TDS) and suspended material (TSM) for 15 river stations and 5 reservoirs along the Kaveri itself and its main tributaries sampled during pre-monsoon, monsoon and post-monsoon periods in 2006 and 2007. The TDS in the Kaveri River globally increases from the upper reaches (humid to sub-humid climate) to the lower reaches (semi-arid climate), and at a given station from monsoon (M) to hot season (HS). The DSi concentrations range from 129 μmol L(-1) (M) to 390 μmol L(-1) (HS) in the main Kaveri stream and reaches up to 686 μmol L(-1) in the Shimsha River (HS). Our results indicate that DSi and the main solutes of the Kaveri River have not drastically changed since the last 30 years despite the population increase. The pollution index of Van der Weijden and Pacheco (2006) ranges from 13% to 54% but DSi does not seem to be affected by domestic wastewater. ASi is mostly composed of diatoms and phytoliths that both play roles in controlling DSi. We suggest that DSi and ASi delivered to the cultivated areas through irrigation from reservoir may have two important consequences: increasing Si bioavailability for crops and limiting Si flux to the ocean. PMID:25244037

  7. Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon.

    PubMed

    Cross, Wyatt F; Baxter, Colden V; Donner, Kevin C; Rosi-Marshall, Emma J; Kennedy, Theodore A; Hall, Robert O; Kelly, Holly A Wellard; Rogers, R Scott

    2011-09-01

    Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high-flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, U.S.A., in an effort to reestablish pulsed flood events, redistribute sediments, improve conditions for native fishes, and increase understanding of how dam operations affect physical and biological processes. We quantified secondary production and organic matter flows in the food web below Glen Canyon dam for two years prior and one year after an experimental controlled flood in March 2008. Invertebrate biomass and secondary production declined significantly following the flood (total biomass, 55% decline; total production, 56% decline), with most of the decline driven by reductions in two nonnative invertebrate taxa, Potamopyrgus antipodarum and Gammarus lacustris. Diatoms dominated the trophic basis of invertebrate production before and after the controlled flood, and the largest organic matter flows were from diatoms to the three most productive invertebrate taxa (P. antipodarum, G. lacustris, and Tubificida). In contrast to invertebrates, production of rainbow trout (Oncorhynchus mykiss) increased substantially (194%) following the flood, despite the large decline in total secondary production of the invertebrate assemblage. This counterintuitive result is reconciled by a post-flood increase in production and drift concentrations of select invertebrate prey (i.e., Chironomidae and Simuliidae) that supported a large proportion of trout production but had relatively low secondary production. In addition, interaction strengths, measured as species impact values, were strongest between rainbow trout and these two taxa before and after the flood, demonstrating that the dominant consumer-resource interactions were not

  8. Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon

    USGS Publications Warehouse

    Cross, Wyatt F.; Baxter, Colden V.; Donner, Kevin C.; Rosi-Marshall, Emma J.; Kennedy, Theodore A.; Hall, Robert O., Jr.; Wellard Kelly, Holly A.; Rogers, R. Scott

    2011-01-01

    Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high-flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, USA, in an effort to reestablish pulsed flood events, redistribute sediments, improve conditions for native fishes, and increase understanding of how dam operations affect physical and biological processes. We quantified secondary production and organic matter flows in the food web below Glen Canyon dam for two years prior and one year after an experimental controlled flood in March 2008. Invertebrate biomass and secondary production declined significantly following the flood (total biomass, 55% decline; total production, 56% decline), with most of the decline driven by reductions in two nonnative invertebrate taxa, Potamopyrgus antipodarum and Gammarus lacustris. Diatoms dominated the trophic basis of invertebrate production before and after the controlled flood, and the largest organic matter flows were from diatoms to the three most productive invertebrate taxa (P. antipodarum, G. lacustris, and Tubificida). In contrast to invertebrates, production of rainbow trout (Oncorhynchus mykiss) increased substantially (194%) following the flood, despite the large decline in total secondary production of the invertebrate assemblage. This counterintuitive result is reconciled by a post-flood increase in production and drift concentrations of select invertebrate prey (i.e., Chironomidae and Simuliidae) that supported a large proportion of trout production but had relatively low secondary production. In addition, interaction strengths, measured as species impact values, were strongest between rainbow trout and these two taxa before and after the flood, demonstrating that the dominant consumer—resource interactions were not

  9. Automated Liquid-Level Control of a Nutrient Reservoir for a Hydroponic System

    NASA Technical Reports Server (NTRS)

    Smith, Boris; Asumadu, Johnson A.; Dogan, Numan S.

    1997-01-01

    A microprocessor-based system for control of the liquid level of a nutrient reservoir for a plant hydroponic growing system has been developed. The system uses an ultrasonic transducer to sense the liquid level or height. A National Instruments' Multifunction Analog and Digital Input/Output PC Kit includes NI-DAQ DOS/Windows driver software for an IBM 486 personal computer. A Labview Full Development system for Windows is the graphical programming system being used. The system allows liquid level control to within 0.1 cm for all levels tried between 8 and 36 cm in the hydroponic system application. The detailed algorithms have been developed and a fully automated microprocessor based nutrient replenishment system has been described for this hydroponic system.

  10. Insights into the Effects of the Spatial Configuration of Flood Retention Ponds on Flood Frequency

    NASA Astrophysics Data System (ADS)

    Ayalew, T. B.; Krajewski, W. F.; Mantilla, R.

    2014-12-01

    the basin. Although the results show that the effect of distributed flood retention ponds on the flood frequency reduces in the downstream direction, the fact that they are distributing the flood control benefits across the catchment, as opposed to a single big reservoir located at the catchment outlet, makes them an attractive and viable flood mitigation alternative.

  11. [The dilemma of data flood - reducing costs and increasing quality control].

    PubMed

    Gassmann, B

    2012-09-01

    Digitization is found everywhere in sonography. Printing of ultrasound images using the videoprinter with special paper will be done in single cases. The documentation of sonography procedures is more and more done by saving image sequences instead of still frames. Echocardiography is routinely recorded in between with so called R-R-loops. Doing contrast enhanced ultrasound recording of sequences is necessary to get a deep impression of the vascular structure of interest. Working with this data flood in daily practice a specialized software is required. Comparison in follow up of stored and recent images/sequences is very helpful. Nevertheless quality control of the ultrasound system and the transducers is simple and safe - using a phantom for detail resolution and general image quality the stored images/sequences are comparable over the life cycle of the system. The comparison in follow up is showing decreased image quality and transducer defects immediately. PMID:22945822

  12. Environmental effects of storage preservation practices: controlled flushing of fine sediment from a small hydropower reservoir.

    PubMed

    Espa, Paolo; Castelli, Elena; Crosa, Giuseppe; Gentili, Gaetano

    2013-07-01

    Sediment flushing may be effective in mitigating loss of reservoir storage due to siltation, but flushing must be controlled to limit the impact on the downstream environment. A reliable prediction of the environmental effects of sediment flushing is hindered by the limited scientific information currently available. Consequently, there may be some controversy as regards to management decisions, planning the work, and monitoring strategies. This paper summarizes the main results of a monitoring campaign on the stream below a small alpine hydropower reservoir subjected to annual flushing between 2006 and 2009. The removed sediment was essentially silt, and the suspended solid concentration (SSC) of the discharged water was controlled to alleviate downstream impact. Control was achieved through hydraulic regulation and mechanical digging, alternating daytime sediment evacuation, and nocturnal clear water release. The four operations lasted about two weeks each and had an average SSC of about 4 g L(-1). Maximum values of SSC were generally kept below 10 g L(-1). Downstream impact was quantified through sampling of fish fauna (brown trout) and macroinvertebrate in the final reach of the effluent stream. The benthic community was severely impaired by the flushing operations, but recovered to pre-flushing values in a few months. As expected, the impact on brown trout was heavier on juveniles. While data biasing due to fish removal and re-stocking cannot be ruled out, the fish community seems to have reached a state of equilibrium characterized by a lower density than was measured before the flushing operations. PMID:23733251

  13. 33 CFR 211.6 - Rights which may be granted by the Secretary of the Army in river and harbor and flood control...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Rights which may be granted by the Secretary of the Army in river and harbor and flood control property. 211.6 Section 211.6... and flood control property. (a) Leases. (1) The Secretary of the Army is authorized, whenever he...

  14. Post waterflood CO{sub 2} miscible flood in light oil, fluvial-dominated deltaic reservoir. Annual report, October 1, 1993--September 30, 1994

    SciTech Connect

    Bou-Mikael, S.

    1995-07-01

    Texaco Exploration and Production Inc. (TEPI) and the U.S. Department of Energy (DOE) entered into a cost sharing cooperative agreement to conduct an Enhanced Oil Recovery demonstration project at Port Neches. The field is located in Orange County near Beaumont, Texas. The project will demonstrate the effectiveness of the CO{sub 2}, miscible process in Fluvial Dominated Deltaic reservoirs. It will also evaluate the use of horizontal CO{sub 2} injection wells to improve the overall sweep efficiency. A data base of FDD reservoirs for the gulf coast region will be developed by LSU, using a screening model developed by Texaco Research Center in Houston. Finally, the results and the information gained from this project will be disseminated throughout the oil industry via a series of SPE papers and industry open forums. Reservoir characterization efforts for the Marginulina sand, are in progress utilizing conventional and advanced technologies including 3-D seismic. Sidewall and conventional. cores were cut and analyzed, lab tests were conducted on reservoir fluids, reservoir BHP pressure and reservoir voidage were monitored as shown. Texaco is utilizing the above data to develop a Stratamodel to best describe and characterize the reservoir and to use it as an input for the compositional simulator. The current compositional model is being revised to integrate the new data from the 3-D seismic and field performance under CO{sub 2} injection, to ultimately develop an accurate economic model. All facilities work has been completed and placed in service including the CO{sub 2} pipeline and metering equipment, CO{sub 2} injection and production equipment, water injection equipment, well work and injection/production lines. The horizontal injection well was drilled and completed on January 15, 1994. CO{sub 2} purchases from Cardox continue at an average rate of 3600 MCFD. The CO{sub 2} is being injected at line pressure of 1350 psi.

  15. Methods of Control of the Leishmania infantum Dog Reservoir: State of the Art

    PubMed Central

    Podaliri Vulpiani, Michele; Iannetti, Luigi; Paganico, Daniela; Iannino, Filomena; Ferri, Nicola

    2011-01-01

    Leishmania infantum is a protozoan parasite causing severe vector-borne visceral diseases both in humans and dogs. The latter are the most important natural reservoir and therefore should be the main target of control measures. The real efficacy of seropositive dogs culling as a direct control method is still debated, and the new sensitivity of large part of population considers ethically unacceptable this kind of approach. Treatment of infectious dogs with one of the available therapeutic protocols is recommendable as it allows to reduce parasite burdens and therefore the possibility of transmission of Leishmania infantum to vectors. Vaccination has been proven to be a very effective control tool, but the absence of a commonly recognized diagnostic method able to distinguish vaccinate from seropositive individuals is still an important limit. Concerning indirect control methods, a number of studies have demonstrated the efficacy of topical insecticides treatment (collars, spot-on, and sprays) in reducing incidence and prevalence of L. infantum. Also, the reduction of the odds of seroconversion in humans in endemic areas has been reported after the application of indirect control measures on dogs. The contemporary use of direct and indirect methods is even more effective in reducing seroprevalence in dogs. PMID:21772963

  16. A Global Hydrological Model with Reservoir Operation Scheme: Global and Regional Applications (Invited)

    NASA Astrophysics Data System (ADS)

    Hanasaki, N.; Masaki, Y.; Mateo, C.; Kanae, S.; Oki, T.

    2013-12-01

    More than 45000 large dams have been constructed all over the world, and their total storage capacity exceeds 7000 km3 which corresponds to approximately 20% of the total annual global river discharge. Explicit incorporation of reservoir operation is indispensable for global-/macro-scale hydrological models, since their storage capacity and potential of altering flow regime are too large to neglect. Our presentation consists of three parts. In the first part, the H08 model, a global hydrological model with reservoir operation scheme is introduced. The H08 model includes an algorithm to estimate reservoir operating rules of individual reservoirs. This enables us to apply the model to the regions and periods with no recorded reservoir operation. The key concepts and challenges of the model are discussed. In the second part, the role of reservoirs in water scarcity is globally assessed. In many parts of the world, local people are suffered from temporal variability in precipitation and river flow. The contribution of reservoirs to water scarcity alleviation is quantitatively and globally assessed. The assessment is extended to the future periods utilizing the latest climate and socio-economic scenarios. In the last part, a regional model application is introduced. The Chao Phraya River in Thailand was suffered from a severe flood in 2011. Vast area was inundated for months and the economic damages reached 40 billion USD. The Chao Phraya River has two major reservoirs and their role is crucial for both water use and flood control. The H08 model is substantially enhanced and applied to the basin to reproduce the 2011 floods. The tradeoff between water use and flood control was investigated by changing reservoir operation options.

  17. [Research progress on phosphorus budgets and regulations in reservoirs].

    PubMed

    Shen, Xiao; Li, Xu; Zhang, Wang-shou

    2014-12-01

    Phosphorus is an important limiting factor of water eutrophication. A clear understanding of its budget and regulated method is fundamental for reservoir ecological health. In order to pro- mote systematic research further and improve phosphorus regulation system, the budget balance of reservoir phosphorus and its influencing factors were concluded, as well as conventional regulation and control measures. In general, the main phosphorus sources of reservoirs include upstream input, overland runoff, industrial and domestic wastewater, aquaculture, atmospheric deposition and sediment release. Upstream input is the largest phosphorus source among them. The principal output path of phosphorus is the flood discharge, the emission load of which is mainly influenced by drainage patterns. In addition, biological harvest also can export a fraction of phosphorus. There are some factors affecting the reservoir phosphorus balance, including reservoirs' function, hydrological conditions, physical and chemical properties of water, etc. Therefore, the phosphorus budgets of different reservoirs vary greatly, according to different seasons and regions. In order to reduce the phosphorus loading in reservoirs, some methods are carried out, including constructed wetlands, prefix reservoir, sediment dredging, biomanipulation, etc. Different methods need to be chosen and combined according to different reservoirs' characteristics and water quality management goals. Thus, in the future research, it is reasonable to highlight reservoir ecological characteristics and proceed to a complete and systematic analysis of the inherent complexity of phosphorus budget and its impact factors for the reservoirs' management. Besides, the interaction between phosphorus budget and other nutrients in reservoirs also needs to be conducted. It is fundamental to reduce the reservoirs' phosphorus loading to establish a scientific and improved management system based on those researches. PMID:25876422

  18. The aging of America's reservoirs: In-reservoir and downstream physical changes and habitat implications

    USGS Publications Warehouse

    Juracek, Kyle E.

    2015-01-01

    Reservoirs are important for various purposes including flood control, water supply, power generation, and recreation. The aging of America's reservoirs and progressive loss of water storage capacity resulting from ongoing sedimentation, coupled with increasing societal needs, will cause the social, economic, environmental, and political importance of reservoirs to continually increase. The short- and medium-term (<50 years) environmental consequences of reservoir construction and operation are well known and include an altered flow regime, lost connectivity (longitudinal, floodplain), an altered sediment regime, substrate compositional change, and downstream channel degradation. In general, reservoir-related changes have had adverse consequences for the natural ecosystem. Longer term (>50 years) environmental changes as reservoirs enter “old” age are less understood. Additional research is needed to help guide the future management of aging reservoir systems and support the difficult decisions that will have to be made. Important research directions include assessment of climate change effects on aging and determination of ecosystem response to ongoing aging and various management actions that may be taken with the intent of minimizing or reversing the physical effects of aging.

  19. N2O fluxes from the littoral zone of a Chinese reservoir

    NASA Astrophysics Data System (ADS)

    Yang, M.; Geng, X. M.; Grace, J.; Jia, Y. F.; Liu, Y. Z.; Jiao, S. W.; Shi, L. L.; Lu, C.; Zhou, Y.; Lei, G. C.

    2015-08-01

    There have been few studies of greenhouse gas emissions from reservoirs, despite the remarkable growth in the number of reservoirs in developing countries. We report a case study that focuses on the littoral zone of a major Chinese reservoir, where we established measurements of N2O fluxes using the static chamber technique at five different water levels (deep water, shallow water, seasonally flooded, control for seasonally flooded, and non-flooded). The "control for seasonal flooded" had similar vegetation to the "seasonally flooded" but was not actually flooded as it was on a higher piece of land. Seasonal, diurnal and spatial variations of N2O flux and environmental factors were monitored throughout the growing season which included a flood event during summer rains. The N2O flux ranged from -136.6 to 381.8 μg m-2 h-1 averaging 6.8 μg m-2 h-1. Seasonal and spatial variation was significant but diurnal variation was not. Non-flooded dry land emitted more N2O than flooded land, no matter whether it was permanently or seasonally flooded. Piecewise correlation was found between N2O flux, air temperature and soil nitrate concentration. Positive correlation was shown between N2O flux and dissolved oxygen in water. There were significantly higher emissions from farmland. We compared these results with our recently published study of CH4 emissions, carried out simultaneously at the same site as those in the present study. Completely different patterns between the two gases are demonstrated. We conclude that the littoral zone is a hotspot for N2O emissions in the summer, especially when the shores of the lake are used for the farming of maize. But in terms of the overall greenhouse gas budget, the fluxes of N2O are not as important as those of CH4.

  20. Using GEFS ensemble forecasts for decision making in reservoir management in California

    NASA Astrophysics Data System (ADS)

    Scheuerer, M.; Hamill, T.; Webb, R. S.

    2015-12-01

    Reservoirs such as Lake Mendocino in California's Russian River Basin provide flood control, water supply, recreation, and environmental stream flow regulation. Many of these reservoirs are operated by the U.S. Army Corps of Engineers (Corps) according to water control manuals that specify elevations for an upper volume of reservoir storage that must be kept available for capturing storm runoff and reducing flood risk, and a lower volume of storage that may be used for water supply. During extreme rainfall events, runoff is captured by these reservoirs and released as quickly as possible to create flood storage space for another potential storm. These flood control manuals are based on typical historical weather patterns - wet during the winter, dry otherwise - but are not informed directly by weather prediction. Alternative reservoir management approaches such as Forecast-Informed Reservoir Operations (FIRO), which seek to incorporate advances in weather prediction, are currently being explored as means to improve water supply availability while maintaining flood risk reduction and providing additional ecosystem benefits.We present results from a FIRO proof-of-concept study investigating the reliability of post-processed GEFS ensemble forecasts to predict the probability that day 6-to-10 precipitation accumulations in certain areas in California exceed a high threshold. Our results suggest that reliable forecast guidance can be provided, and the resulting probabilities could be used to inform decisions to release or hold water in the reservoirs. We illustrate the potential of these forecasts in a case study of extreme event probabilities for the Russian River Basin in California.

  1. Sequence stratigraphic and synsedimentary tectonic controls on reservoir compartmentalization in a transgressive sequence set: Almond formation, southwest Wyoming

    SciTech Connect

    Krystinik, L.F.; Mead, R.H. )

    1996-01-01

    The Campanian upper Almond Formation in Southwestern Wyoming contains at least 15 aggradational to backstepping microtidal to low mesotidal barrier/shoreline complexes laid down during a period of net transgression from 72 to 70.5 million years ago. Reservoir compartmentalization in the upper Almond occurs at several scales, including an aggradational to retrogradations sequence set composed of 3 retrogradational parasequence sets; numerous parasequences, and diverse barrier sub-facies units. The lowstand shorelines of these sequence sets stack aggradationally prior to transgression by a really extensive, marine mudstone horizons which separate the sequences. Highstand systems tracts are poorly preserved, often completely removed below fourth of fifth order sequence boundaries which cause seaward jumps of facies in excess of 30 Km and place fluvial sediment, coal and lagoonal deposits abruptly over marine mudstone. Each sequence in the upper Almond is composed of several parasequences (sanding-upward, storm-dominated barrier shorefaces) which intercalate with marine mudstone to the east and grade into oyster-bearing, organic-rich lagoonal mudstone to the west. Compartmentalization in the barrier complexes occurs at most parasequence boundaries and in association with major sub-facies; boundaries (barrier margins, tidal inlets, flood-tidal deltas, washover fans). Further reservoir compartmentalization is induced by synsedimentary faulting and subsidence which locally preserve isolated reservoir-quality barrier/shoreline sandstone bodies by dropping them below the depth of ravinement (5-30 m). The recognition of synsedimentary faulting and subsequent ravinement is critical to accurate sequence stratigraphic analysis and for prediction of reservoir compartments.

  2. Sequence stratigraphic and synsedimentary tectonic controls on reservoir compartmentalization in a transgressive sequence set: Almond formation, southwest Wyoming

    SciTech Connect

    Krystinik, L.F.; Mead, R.H.

    1996-12-31

    The Campanian upper Almond Formation in Southwestern Wyoming contains at least 15 aggradational to backstepping microtidal to low mesotidal barrier/shoreline complexes laid down during a period of net transgression from 72 to 70.5 million years ago. Reservoir compartmentalization in the upper Almond occurs at several scales, including an aggradational to retrogradations sequence set composed of 3 retrogradational parasequence sets; numerous parasequences, and diverse barrier sub-facies units. The lowstand shorelines of these sequence sets stack aggradationally prior to transgression by a really extensive, marine mudstone horizons which separate the sequences. Highstand systems tracts are poorly preserved, often completely removed below fourth of fifth order sequence boundaries which cause seaward jumps of facies in excess of 30 Km and place fluvial sediment, coal and lagoonal deposits abruptly over marine mudstone. Each sequence in the upper Almond is composed of several parasequences (sanding-upward, storm-dominated barrier shorefaces) which intercalate with marine mudstone to the east and grade into oyster-bearing, organic-rich lagoonal mudstone to the west. Compartmentalization in the barrier complexes occurs at most parasequence boundaries and in association with major sub-facies; boundaries (barrier margins, tidal inlets, flood-tidal deltas, washover fans). Further reservoir compartmentalization is induced by synsedimentary faulting and subsidence which locally preserve isolated reservoir-quality barrier/shoreline sandstone bodies by dropping them below the depth of ravinement (5-30 m). The recognition of synsedimentary faulting and subsequent ravinement is critical to accurate sequence stratigraphic analysis and for prediction of reservoir compartments.

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

    NASA Astrophysics Data System (ADS)

    Gunawan, A. P.

    2015-12-01

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

  4. Post waterflood CO{sub 2} miscible flood in light oil fluvial - dominated deltaic reservoirs. Fourth quarterly progress report, July 1, 1995--September 30, 1995

    SciTech Connect

    1995-11-10

    Production from the Marg Area 1 at Port Neches is averaging 222 BOPD for this quarter. The production drop is due in part to mechanical problems and to poor sweep efficiency caused by water blockage that prevented the CO{sub 2} from contacting new residual oil deeper in the reservoir. Alternating water and gas injection assisted to some extent in maintaining oil production and improved the reservoir yield by reducing the gas production. A workover was performed on well Kuhn No. 38 to correct failed gravel pack setting. Production from the well was restored to 60 BOPD. Plugging of the injection wells continue to be a problem, reducing the injection rate in critical areas of the reservoir, near well Kuhn No. 15R. Texaco drilled the well Polk B No. 39 to The Marg Area 3 reservoir to gain structural position based on the 3D seismic, and found the sand present as anticipated. However, the sand did not have any hydrocarbon accumulation. For this reason, Texaco will abandon testing the idea of utilizing CO{sub 2} to accelerate the primary production rate and reduce water production and primary production cycle time, in the reservoir.

  5. A chemical EOR benchmark study of different reservoir simulators

    NASA Astrophysics Data System (ADS)

    Goudarzi, Ali; Delshad, Mojdeh; Sepehrnoori, Kamy

    2016-09-01

    Interest in chemical EOR processes has intensified in recent years due to the advancements in chemical formulations and injection techniques. Injecting Polymer (P), surfactant/polymer (SP), and alkaline/surfactant/polymer (ASP) are techniques for improving sweep and displacement efficiencies with the aim of improving oil production in both secondary and tertiary floods. There has been great interest in chemical flooding recently for different challenging situations. These include high temperature reservoirs, formations with extreme salinity and hardness, naturally fractured carbonates, and sandstone reservoirs with heavy and viscous crude oils. More oil reservoirs are reaching maturity where secondary polymer floods and tertiary surfactant methods have become increasingly important. This significance has added to the industry's interest in using reservoir simulators as tools for reservoir evaluation and management to minimize costs and increase the process efficiency. Reservoir simulators with special features are needed to represent coupled chemical and physical processes present in chemical EOR processes. The simulators need to be first validated against well controlled lab and pilot scale experiments to reliably predict the full field implementations. The available data from laboratory scale include 1) phase behavior and rheological data; and 2) results of secondary and tertiary coreflood experiments for P, SP, and ASP floods under reservoir conditions, i.e. chemical retentions, pressure drop, and oil recovery. Data collected from corefloods are used as benchmark tests comparing numerical reservoir simulators with chemical EOR modeling capabilities such as STARS of CMG, ECLIPSE-100 of Schlumberger, REVEAL of Petroleum Experts. The research UTCHEM simulator from The University of Texas at Austin is also included since it has been the benchmark for chemical flooding simulation for over 25 years. The results of this benchmark comparison will be utilized to improve

  6. 4D seismic to image a thin carbonate reservoir during a miscible C02 flood: Hall-Gurney Field, Kansas, USA

    USGS Publications Warehouse

    Raef, A.E.; Miller, R.D.; Franseen, E.K.; Byrnes, A.P.; Watney, W.L.; Harrison, W.E.

    2005-01-01

    The movement of miscible CO2 injected into a shallow (900 m) thin (3.6-6m) carbonate reservoir was monitored using the high-resolution parallel progressive blanking (PPB) approach. The approach concentrated on repeatability during acquisition and processing, and use of amplitude envelope 4D horizon attributes. Comparison of production data and reservoir simulations to seismic images provided a measure of the effectiveness of time-lapse (TL) to detect weak anomalies associated with changes in fluid concentration. Specifically, the method aided in the analysis of high-resolution data to distinguish subtle seismic characteristics and associated trends related to depositional lithofacies and geometries and structural elements of this carbonate reservoir that impact fluid character and EOR efforts.

  7. Managing the Arroyo Seco for Flood Prevention, Erosion Control, Waterway and Habitat Restoration

    SciTech Connect

    Sanchez, L; Wang, C; Laurant, J

    2003-02-06

    One of the most important tasks for a site facility manager is to ensure that appropriate channel erosion controls are applied to on-site drainage channels. These erosion controls must minimize risks to the public and structures. Water and sediment loads commonly originate from off-site sources and many of the traditional reactionary measures (installing rip-rap or some other form of bed or bank armor) simply transfer or delay the problem. State and federal agency requirements further complicate the management solution. One case in point is the Arroyo Seco, an intermittent stream that runs along the southwest corner of the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. In 2001, LLNL contracted Questa Engineering Corporation to conduct hydraulic, geomorphic, and biological investigations and to prepare an alternatives and constraints analysis. From these investigations, LLNL has selected a water management plan that encompasses overall flood prevention, erosion control, and waterway and habitat restoration and enhancement elements. The most unique aspect of the Arroyo Seco management plan is its use of non-traditional and biotechnical techniques.

  8. Architecture Controls on Reservoir Performance of Zubair Formation, Rumaila and West Qurna Oilfields in the Southern Iraq

    NASA Astrophysics Data System (ADS)

    Al-Ziayyir, Haitham; Hodgetts, David

    2015-04-01

    The main reservoir in Rumaila /West Qurna oilfields is the Zubair Formation of Hautervian and Barremian age. This silicilastic formation extends over the regions of central and southern Iraq. This study attempts to improve the understanding of the architectural elements and their control on fluid flow paths within the Zubair Formation. A significant source of uncertainty in the zubair formation is the control on hydrodynamic pressure distribution. The reasons for pressure variation in the Zubair are not well understood. This work aims to reduce this uncertainty by providing a more detailed knowledge of reservoir architecture, distribution of barriers and baffles, and reservoir compartmentalization. To characterize the stratigraphic architecture of the Zubair formation,high resolution reservoir models that incorporate dynamic and static data were built. Facies modelling is accomplished by means of stochastic modelling techniques.The work is based on a large data set collected from the Rumaila oilfields. These data, comprising conventional logs of varying vintages, NMR logs, cores from six wells, and pressure data, were used for performing geological and petrophysical analyses.Flow simulation studies have also been applied to examine the impact of architecture on recovery. Understanding of geology and reservoir performance can be greatly improved by using an efficient, quick and viable integrated analysis, interpretation, and modelling.

  9. Coupled hydrogeomorphic and woody-seedling responses to controlled flood releases in a dryland river

    USGS Publications Warehouse

    Wilcox, Andrew C.; Shafroth, Patrick B.

    2013-01-01

    Interactions among flow, geomorphic processes, and riparian vegetation can strongly influence both channel form and vegetation communities. To investigate such interactions, we took advantage of a series of dam-managed flood releases that were designed in part to maintain a native riparian woodland system on a sand-bed, dryland river, the Bill Williams River, Arizona, USA. Our resulting multiyear flow experiment examined differential mortality among native and nonnative riparian seedlings, associated flood hydraulics and geomorphic changes, and the temporal evolution of feedbacks among vegetation, channel form, and hydraulics. We found that floods produced geomorphic and vegetation responses that varied with distance downstream of a dam, with scour and associated seedling mortality closer to the dam and aggradation and burial-induced mortality in a downstream reach. We also observed significantly greater mortality among nonnative tamarisk (Tamarix) seedlings than among native willow (Salix gooddingii) seedlings, reflecting the greater first-year growth of willow relative to tamarisk. When vegetation was small early in our study period, the effects of vegetation on flood hydraulics and on mediating flood-induced channel change were minimal. Vegetation growth in subsequent years resulted in stronger feedbacks, such that vegetation's stabilizing effect on bars and its drag effect on flow progressively increased, muting the geomorphic effects of a larger flood release. These observations suggest that the effectiveness of floods in producing geomorphic and ecological changes varies not only as a function of flood magnitude and duration, but also of antecedent vegetation density and size.

  10. Reservoir Systems in Changing Climate

    NASA Astrophysics Data System (ADS)

    Lien, W.; Tung, C.; Tai, C.

    2007-12-01

    Climate change may cause more climate variability and further results in more frequent extreme hydrological events which may greatly influence reservoir¡¦s abilities to provide service, such as water supply and flood mitigation, and even danger reservoir¡¦s safety. Some local studies have identified that climate change may cause more flood in wet period and less flow in dry period in Taiwan. To mitigate climate change impacts, more reservoir space, i.e. less storage, may be required to store higher flood in wet periods, while more reservoir storage may be required to supply water for dry periods. The goals to strengthen adaptive capacity of water supply and flood mitigation are conflict under climate change. This study will focus on evaluating the impacts of climate change on reservoir systems. The evaluation procedure includes hydrological models, a reservoir water balance model, and a water supply system dynamics model. The hydrological models are used to simulate reservoir inflows under different climate conditions. Future climate scenarios are derived from several GCMs. Then, the reservoir water balance model is developed to calculate reservoir¡¦s storage and outflows according to the simulated inflows and operational rules. The ability of flood mitigation is also evaluated. At last, those outflows are further input to the system dynamics model to assess whether the goal of water supply can still be met. To mitigate climate change impacts, the implementing adaptation strategies will be suggested with the principles of risk management. Besides, uncertainties of this study will also be analyzed. The Feitsui reservoir system in northern Taiwan is chosen as a case study.

  11. How secure is subsurface CO2 storage? Controls on leakage in natural CO2 reservoirs

    NASA Astrophysics Data System (ADS)

    Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, Stuart

    2014-05-01

    Carbon Capture and Storage (CCS) is the only industrial scale technology available to directly reduce carbon dioxide (CO2) emissions from fossil fuelled power plants and large industrial point sources to the atmosphere. The technology includes the capture of CO2 at the source and transport to subsurface storage sites, such as depleted hydrocarbon reservoirs or saline aquifers, where it is injected and stored for long periods of time. To have an impact on the greenhouse gas emissions it is crucial that there is no or only a very low amount of leakage of CO2 from the storage sites to shallow aquifers or the surface. CO2 occurs naturally in reservoirs in the subsurface and has often been stored for millions of years without any leakage incidents. However, in some cases CO2 migrates from the reservoir to the surface. Both leaking and non-leaking natural CO2 reservoirs offer insights into the long-term behaviour of CO2 in the subsurface and on the mechanisms that lead to either leakage or retention of CO2. Here we present the results of a study on leakage mechanisms of natural CO2 reservoirs worldwide. We compiled a global dataset of 49 well described natural CO2 reservoirs of which six are leaking CO2 to the surface, 40 retain CO2 in the subsurface and for three reservoirs the evidence is inconclusive. Likelihood of leakage of CO2 from a reservoir to the surface is governed by the state of CO2 (supercritical vs. gaseous) and the pressure in the reservoir and the direct overburden. Reservoirs with gaseous CO2 is more prone to leak CO2 than reservoirs with dense supercritical CO2. If the reservoir pressure is close to or higher than the least principal stress leakage is likely to occur while reservoirs with pressures close to hydrostatic pressure and below 1200 m depth do not leak. Additionally, a positive pressure gradient from the reservoir into the caprock averts leakage of CO2 into the caprock. Leakage of CO2 occurs in all cases along a fault zone, indicating that

  12. [Dynamics of tritium content in flood-lands reservoirs of the Pripyat river and cooling pond of the Chernobyl nuclear plant].

    PubMed

    Gudkov, D I

    1999-01-01

    Tritium content in water from natural and artificial reservoirs within 30-km exclusion zone of the Chernobyl NPP has been determined. The increase of Tritium activity in the involved water reserwous has been registered in May 1994 and April 1995. As supposed the source of the increase, nuclear power plants, equipped with WWER reactors and located in catchment area of Pripyat river. PMID:10689425

  13. Design and Implementation of a C02 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells in a Shallow Shelf Carbonate Approaching Waterflood Depletion

    SciTech Connect

    1997-08-01

    The objective is to utilize reservoir characteristics and advanced technologies to optimize the design of a carbon dioxide (CO2) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. Also the project seeks to demonstrate the performance and economic viability of the project in the field.

  14. Beaver dams, hydrological thresholds, and controlled floods as a management tool in a desert riverine ecosystem, Bill Williams River, Arizona

    USGS Publications Warehouse

    Andersen, D.C.; Shafroth, P.B.

    2010-01-01

    Beaver convert lotic stream habitat to lentic through dam construction, and the process is reversed when a flood or other event causes dam failure. We investigated both processes on a regulated Sonoran Desert stream, using the criterion that average current velocity is < 0.2 m s-1 in a lentic reach. We estimated temporal change in the lotic:lentic stream length ratio by relating beaver pond length (determined by the upstream lentic-lotic boundary position) to dam size, and coupling that to the dam-size frequency distribution and repeated censuses of dams along the 58-km river. The ratio fell from 19:1 when no beaver dams were present to < 3:1 after 7 years of flows favourable for beaver. We investigated the dam failure-flood intensity relationship in three independent trials (experimental floods) featuring peak discharge ranging from 37 to 65 m3 s-1. Major damage (breach ??? 3-m wide) occurred at ??? 20% of monitored dams (n = 7-86) and a similar or higher proportion was moderately damaged. We detected neither a relationship between dam size and damage level nor a flood discharge threshold for initiating major damage. Dam constituent materials appeared to control the probability of major damage at low (attenuated) flood magnitude. We conclude that environmental flows prescribed to sustain desert riparian forest will also reduce beaver-created lentic habitat in a non-linear manner determined by both beaver dam and flood attributes. Consideration of both desirable and undesirable consequences of ecological engineering by beaver is important when optimizing environmental flows to meet ecological and socioeconomic goals. ?? 2010 John Wiley & Sons, Ltd.

  15. [Community Structure Characteristics of Diatom in Reservoirs Located in the South of Jiangsu Province, China and Its Control Factors].

    PubMed

    Ren, Jie; Zhou, Tao; Zhu, Guang-wei; Jin, Ying-wei; Cui, Yang; Xu, Hai; Zhu, Meng-yuan; Xia, Ming-fang; Chen, Wei-min

    2016-05-15

    In order to understand the community structure characteristics of Bacillariophyta and its controlling factors in reservoirs located in the Southeast, China, in the geographic background of hills landscape and humid climate, 18 reservoirs were investigated in June, 2015, during the period with high risk of diatom bloom, covering water quality, and the community structures of phytoplankton. The correlations between Bacillariophyta and other planktons with nutrients, water depth, storage capacity, etc. were analyzed. The results showed that, 10 reservoirs reached the light extent of diatom bloom ( density between 100 x 10⁴-1,000 x 10⁴ cells · L⁻¹ reservoirs in this area were generally in mesotrophic or eutrophic state with considerably high total nitrogen concentrations; total phosphorus and trophic level index were both closely correlated with Bacillariophyta biomass. Phormidium in Cyanophyta was the dominating generus among phytoplankton in terms of density; with respect to biomass, Bacillariophyta, Chlorophyta and Cyanophyta were the top three phylum, and Bacillariophyta accounted for 46. 8% of the total phytoplankton biomass, becoming the most important one resulting in abnormal propagation of algae; Synedra (51.5%) and Cyclotella (21.4%) were the main dominating genera in Bacillariophyta, together with Achnanthes and Melosira. Deep water was favored by Bacillariophyta to dominate among different phyla. Larger ratio between catchment and reservoir storage capacity, on the other hand, caused the increase of trophic level and chlorophyll, and benefited the shift of dominating phytoplankton from Bacillariophyta to Chlorophyta and Cyanophyta, by which, the risk of algae bloom would be increased. It reveals that to alleviate the risk of algae bloom and protect drinking water resources, catchment management is crucial for the studied reservoirs. And the establishment of nutrient reduction strategies needs to consider the features of each individual reservoir, i

  16. Controls on nitrous oxide production and consumption in reservoirs of the Ohio River Basin

    NASA Astrophysics Data System (ADS)

    Beaulieu, Jake J.; Nietch, Christopher T.; Young, Jade L.

    2015-10-01

    Aquatic ecosystems are a globally significant source of nitrous oxide (N2O), a potent greenhouse gas, but estimates are largely based on studies conducted in streams and rivers with relatively less known about N2O dynamics in reservoirs. Due to long water residence times and high nitrogen (N) loading rates, reservoirs support substantial N processing and therefore may be particularly important sites of N2O production. Predicting N2O emissions from reservoirs is difficult due to complex interactions between microbial N processing in the oxygen-poor hypolimnion and oxygen-rich epilimnion. Here we present the results of a survey of N2O depth profiles in 20 reservoirs draining a broad range of land use conditions in four states in the U.S. Nitrous oxide was supersaturated in the epilimnion of 80% of the reservoirs and was undersaturated in only one, indicating that reservoirs in this region are generally a source of N2O to the atmosphere. Nitrous oxide was undersaturated in the hypolimnion of 10 reservoirs, supersaturated in 9, and transitioned from supersaturation to undersaturation in 1 reservoir that was monitored periodically from midsummer to fall. All reservoirs with a mean hypolimnion nitrate concentration less than 50 µg N L-1 showed evidence of net N2O consumption in the hypolimnion. All reservoirs sampled during lake turnover supported N2O production throughout the water column. These results indicate that N2O dynamics in reservoirs differ widely both among systems and through time but can be predicted based on N and oxygen availability and degree of thermal stratification.

  17. Intelligent control for modeling of real-time reservoir operation, part II: artificial neural network with operating rule curves

    NASA Astrophysics Data System (ADS)

    Chang, Ya-Ting; Chang, Li-Chiu; Chang, Fi-John

    2005-04-01

    To bridge the gap between academic research and actual operation, we propose an intelligent control system for reservoir operation. The methodology includes two major processes, the knowledge acquired and implemented, and the inference system. In this study, a genetic algorithm (GA) and a fuzzy rule base (FRB) are used to extract knowledge based on the historical inflow data with a design objective function and on the operating rule curves respectively. The adaptive network-based fuzzy inference system (ANFIS) is then used to implement the knowledge, to create the fuzzy inference system, and then to estimate the optimal reservoir operation. To investigate its applicability and practicability, the Shihmen reservoir, Taiwan, is used as a case study. For the purpose of comparison, a simulation of the currently used M-5 operating rule curve is also performed. The results demonstrate that (1) the GA is an efficient way to search the optimal input-output patterns, (2) the FRB can extract the knowledge from the operating rule curves, and (3) the ANFIS models built on different types of knowledge can produce much better performance than the traditional M-5 curves in real-time reservoir operation. Moreover, we show that the model can be more intelligent for reservoir operation if more information (or knowledge) is involved.

  18. [Microbial metabolic characteristics and ecological controlling in petroleum reservoir--a review].

    PubMed

    Gao, Peike; Ma, Ting; Liu, Rulin

    2011-06-01

    Petroleum reservoir has a variety of microbes with diverse metabolic characteristics and great diversity. These microbes play an important role in geochemical cycle. Research on their metabolism and ecological relationships enables the understanding of Microbial Enhanced Oil Recovery (MEOR). Based on the present researches, we review the microbial metabolic characteristics and ecological relationships in oil reservoir. PMID:21866693

  19. Design and implementation of a CO2 flood utilizing advanced reservoirs characterization and horizontal injection wells in a shallow shelf carbonate approaching water floods depletion: Technical progress report, January 1, 1997--March 31, 1997

    SciTech Connect

    Chimahusky, J.S., Casteel, J.F.

    1997-05-01

    The first objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO{sub 2}) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second objective is to demonstrate the performance and economic viability of the project in the field. All work this quarter falls within the demonstration project.

  20. 33 CFR 208.82 - Hetch Hetchy, Cherry Valley, and Don Pedro Dams and Reservoirs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Hetch Hetchy, Cherry Valley, and Don Pedro Dams and Reservoirs. 208.82 Section 208.82 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.82 Hetch Hetchy, Cherry Valley, and Don Pedro Dams and...

  1. 33 CFR 208.82 - Hetch Hetchy, Cherry Valley, and Don Pedro Dams and Reservoirs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Hetch Hetchy, Cherry Valley, and Don Pedro Dams and Reservoirs. 208.82 Section 208.82 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE FLOOD CONTROL REGULATIONS § 208.82 Hetch Hetchy, Cherry Valley, and Don Pedro Dams and...

  2. Age at Virologic Control Influences Peripheral Blood HIV Reservoir Size and Serostatus in Perinatally-Infected Adolescents

    PubMed Central

    Persaud, Deborah; Patel, Kunjal; Karalius, Brad; Rainwater-Lovett, Kaitlin; Ziemniak, Carrie; Ellis, Angela; Chen, Ya Hui; Richman, Douglas; Siberry, George K.; Van Dyke, Russell B.; Burchett, Sandra; Seage, George R.; Luzuriaga, Katherine

    2014-01-01

    Importance Combination antiretroviral therapy (cART) initiated within several weeks of HIV infection in adults limits proviral reservoirs that preclude HIV cure. Biomarkers of restricted proviral reservoirs may aid in the monitoring of HIV remission or cure. Objectives To quantify peripheral blood proviral reservoir size in perinatally HIV-infected adolescents and to identify correlates of limited proviral reservoirs. Design, Setting, and Participants A cross-sectional study including 144 perinatally HIV-infected (PHIV+) youth (median age: 14.3 years), enrolled in the US-based Pediatric HIV/AIDS Cohort Study, on durable (median: 10.2 years) cART, stratified by age at virologic control. Main Outcome and Measures The primary endpoint was peripheral blood mononuclear cell (PBMC) proviral load following virologic control at different ages. Correlations between proviral load and markers of active HIV production (HIV-specific antibodies, 2-long terminal repeat (2-LTR) circles), and markers of immune activation and inflammation were also assessed. Results Proviral reservoir size was markedly reduced in the PHIV+ youth who achieved virologic control by age 1 year (4.2 [interquartile range, 2.6-8 6] copies per 1 million PBMCs) compared to those who achieved virologic control between 1-5 years of age (19.4 [interquartile range, 5.5-99.8] copies per 1 million PBMCs) or after age 5 years (−(70.7 [interquartile range, 23.2-209.4] copies per 1 million PBMCs; P < .00l). A proviral burden <10 copies/million PBMCs was measured in 11 (79%), 20 (40%), and 13 (18%) participants with virologic control at ages <1 year, 1-5 years, and >5 years, respectively (p<0.001). Lower proviral load was associated with undetectable 2-LTR circles (p<0.001) and HIV negative or indeterminate serostatus (p<0.001), but not with concentrations of soluble immune activation markers CD14 and CD163. Conclusions and Relevance Early effective cART along with prolonged virologic suppression after perinatal HIV

  3. Development of improved-mobility control agents for surfactant/polymer flooding. Final report

    SciTech Connect

    Martin, F D; Donaruma, L G; Hatch, M J

    1982-02-23

    During the first year, the initial phase of the project included a literature survey of surfactant/polymer flooding, a summary of the current status of DOE-sponsored polymer and surfactant/polymer field projects, and a survey of oil industry personnel regarding difficulties encountered in the use of commercially available polymers. Major problems in the use of partially hydrolyzed polyacrylamides were identified. Purpose of Phase 1 was to delineate the strengths and weaknesses of commercial polymers. Laboratory tests in the second phase then were designed to measure and compare the factors considered to be of greatest importance. During the second year of the project, the Phase 2 baseline screening tests were completed, and Phase 3 work commenced on the synthesis, characterization, and preliminary screening of new or modified polymers. During the final year of the project, the preliminary screening tests were completed and polymers of interest were evaluated in more detail. This final report contains highlights of the significant accomplishments of the project and presents our conclusions regarding the development of improved mobility control agents. The work has shown that moderate changes in the basic structure of acrylamide polymers can produce significant effects on performance in oil recovery applications. Better viscosity retention in brine can be obtained by stiffening the polymer chain of acrylamide-type materials. Enhanced shear stability can be attained by increasing the polymer hydrophilicity.

  4. Design and Implementation of a CO(2) Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells in Shallow Shelf Carbonate Approaching Waterflood Depletion

    SciTech Connect

    Harpole, K.J.; Dollens, K.B.; Durrett, E.G.; Bles, J.S

    1997-10-31

    The first objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second objective is to demonstrate the performance and economic viability of the project in the field. All work this quarter falls within the demonstration project.

  5. Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion

    SciTech Connect

    Czirr, Kirk

    1999-10-28

    The first project objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO2) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second project objective is to demonstrate the performance and economic viability of the project in the field. All work during the fourth quarter falls within the demonstration project.

  6. Design and Implementation of a C02 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells in a Shallow Carbonate Approaching Waterflood Depletion

    SciTech Connect

    J. Scott Bles; Kimberly B. Dollens

    1998-04-28

    The first project objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO2) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second project objective is to demonstrate the performance and economic viability of the project in the field. All work during the fourth quarter falls within the demonstration project.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  8. Post waterflood CO{sub 2} miscible flood in light oil fluvial: Dominated deltaic reservoirs. Third quarterly report, April 1, 1995--June 30, 1995

    SciTech Connect

    1995-07-15

    Production from the Marg Area 1 at Port Neches is averaging 337 BOPD for this quarter. The production drop is due to fluctuation in both GOR and BS&W on various producing wells, low water injectivity in the reservoir and shut-in one producing well to perform a workover to replace a failed gravel pack setting. Coil tubing work was performed on 2 injection wells in order to resume injection of water and CO{sub 2} in the reservoir. The Marg Area 2 did not respond favorably to CO{sub 2} injection in the Kuhn No. 6 well. For this reason Texaco will not pursue any further development of this section of the reservoir due mainly to low target reserves. Instead Texaco will reallocate the money to a new Marg segment (Marg Area 3) in order to test a new process that will utilize the CO{sub 2} to accelerate the primary production rates and reduce cycle time. Also the process should reduce water disposal cost, cash lifting cost, operating cost and increase the NPV of the reserves.

  9. Post waterflood CO{sub 2} miscible flood in light oil fluvial dominated deltaic reservoirs. Second quarterly technical progress report, [January 1, 1995--March 31, 1995

    SciTech Connect

    1995-07-01

    Production from the Marg Area 1 at Port Neches is averaging 392 barrels of oil per day (BOPD) for this quarter. The production drop is due to fluctuation in both GOR and BS&W on various producing well, coupled with low water injectivity in the reservoir. We were unable to inject any tangible amount of water in the reservoir since late January. Both production and injection problems are currently being evaluated to improve reservoir performance. Well Kuhn (No. 6) was stimulated with 120 MMCF of CO{sub 2}, and was placed on production in February 1, 1995. The well was shut in for an additional month after producing dry CO{sub 2} initially. The well was opened again in early April and is currently producing about 40 BOPD. CO{sub 2} injection averaged 11.3 MMCFD including 4100 MMCFD purchased from Cardox, while water injection averaged 1000 BWPD with most of the injection occurring in the month of January.

  10. Response of ground-water levels of flood control operations in three basins, south-eastern Florida

    USGS Publications Warehouse

    Pitt, William A.J.

    1974-01-01

    Three basins in southeastern Florida were investigated to determine the changes in ground-water levels and canal flows that occurred in response to operation of coastal water-control structures in each canal. All three basins are underlain by the Biscayne aquifer. They are, Snapper Creek Canal basin, where the Biscayne aquifer is of high permeability; the Snake Creek Canal basin, where the aquifer is of moderate permeability; and the Pompano-Cypress Canal basin, where the aquifer is of low permeability. In each basin, drainage is a function of permeability; thus, where the permeability of the aquifer is high, drainage is excellent. The coastal water-conrol structures are intended to afford flood protection in the three basins. In general the control operation criteria for flood control in newly developing areas in southeastern Florida do not provide adequate protection from flooding because of the time required for the aquifer to respond to changes in the controls. Adequate protection would require increasing the density of secondary drainage canals, but this could achieved only by reducing the quantity of water available for recharging those segments of the Biscayne aquifer adjacent to the canals. (Woodrad-USGS)

  11. Reservoir-flooded river mouth areas as sediment traps revealing erosion from peat mining areas - Jukajoki case study in eastern Finland

    NASA Astrophysics Data System (ADS)

    Tahvanainen, Teemu; Meriläinen, Henna-Kaisa; Haraguchi, Akira; Simola, Heikki

    2016-04-01

    Many types of soil-disturbing land use have caused excess sedimentation in Finnish lakes. Identification and quantification of catchment sources of sediment material is crucial in cases where demands for remediation measures are considered. We studied recent (50 yr) sediments of four small rivers, all draining to a reservoir impounded in 1971. Catchments of two of the rivers had had peat mining activities from early 1980s until recently, exposing large areas of peat surfaces to erosion. The water level of the reservoir had risen to the river mouth areas of all rivers, while in each case, the river mouth areas still form riverine narrows separable from the main reservoir, hence collecting sedimentation from their own catchments. The original soils under the reservoir water level could readily be observed in core samples, providing a dated horizon under recent sediments. In addition, we used 137Cs-stratigraphies for dating of samples from original river bed locations. As expected, recent sediments of rivers with peat mining influence differed from others e.g. by high organic content and C:N ratios. Stable isotopes 13C and 15N both correlated with C:N (r = 0.799 and r = -0.717, respectively) and they also differentiated the peat-mining influenced samples from other river sediments. Principal components of the physical-chemical variables revealed clearer distinction than any variables separately. Light-microscopy revealed abundance of leafs of Sphagnum mosses in peat-mining influenced river sediments that were nearly absent from other rivers. Spores of Sphagnum were, however, abundant in all river sediments indicating their predominantly airborne origin. We find that combination of several physical-chemical characters rather than any single variable and microscopy of plant remains can result in reliable recognition of peatland-origin of sediment material when non-impacted sites are available for comparison. Dating of disturbed recent sediments is challenging. River

  12. A grassed waterway and earthen dams to control muddy floods from a cultivated catchment of the Belgian loess belt

    NASA Astrophysics Data System (ADS)

    Evrard, Olivier; Vandaele, Karel; van Wesemael, Bas; Bielders, Charles L.

    2008-08-01

    Muddy floods, i.e. runoff from cultivated areas carrying large quantities of soil, are frequent and widespread in the European loess belt. They are mainly generated in dry zero-order valleys and are nowadays considered as the most likely process transferring material eroded from cultivated hillslopes during the Holocene to the flood plain. The huge costs of muddy flood damages justify the urgent installation of control measures. In the framework of the 'Soil Erosion Decree' of the Belgian Flemish region, a 12 ha-grassed waterway and three earthen dams have been installed between 2002-2004 in the thalweg of a 300-ha cultivated dry valley in the Belgian loess belt. The measures served their purpose by preventing any muddy flood in the downstream village, despite the occurrence of several extreme rainfall events (with a maximum return period of 150 years). The catchment has been intensively monitored from 2005-2007 and 39 runoff events were recorded in that period. Peak discharge (per ha) was reduced by 69% between the upstream and the downstream extremities of the grassed waterway (GWW). Furthermore, runoff was buffered for 5-12 h behind the dams, and the lag time at the outlet of the catchment was thereby increased by 75%. Reinfiltration was also observed within the waterway, runoff coefficients decreasing by a mean of 50% between both extremities of the GWW. Sediment discharge was also reduced by 93% between the GWW's inflow and the outlet. Before the installation of the control measures, specific sediment yield (SSY) of the catchment reached 3.5 t ha - 1 yr - 1 and an ephemeral gully was observed nearly each year in the catchment. Since the control measures have been installed, no (ephemeral) gully has developed and the SSY of the catchment dropped to a mean of 0.5 t ha - 1 yr - 1 . Hence, sediment transfer from the cultivated dry valley to the alluvial plain should dramatically decrease. Total cost of the control measures that are built for a 20 year-period is

  13. Controlled sediment flushing at the Cancano Reservoir (Italian Alps): Management of the operation and downstream environmental impact.

    PubMed

    Espa, Paolo; Brignoli, Maria Laura; Crosa, Giuseppe; Gentili, Gaetano; Quadroni, Silvia

    2016-11-01

    Sediment flushing may be effective to preserve reservoir storage, but concerns arise about sustainability for downstream freshwater ecosystems. We report on the controlled flushing of approximately 110,000 tons of silt from a 120 Mm(3) reservoir on the Adda River, the main tributary of Lake Como, Italy. Technical constraints prevented flushing during high flows, and the operation had to be spread out over three consecutive years (2010-2012) and, for each year, over a rather long time span (40-50 days). To mitigate the downstream impact, the suspended sediment concentration (SSC) of the evacuated water was controlled by regulating the dislodging works inside the reservoir, increasing the streamflow in the regulated tributaries, and operating an instream settling basin. SSC and water flow as well as benthic macroinvertebrates and trout were monitored as far as 28 km below the reservoir. At the most upstream gauging station, SSC peaked up to 100 g/l and ranged from 3.5 to 8 g/l on average per each operation. Stream quality metrics based on macroinvertebrate data evidenced the impairment due to flushing; however, the benthic community showed high resilience, recovering to pre-flushing conditions in 6-9 months. Trout data were biased by stocking and sport fishing and were more difficult to be interpreted. The trout population wouldn't seem remarkably altered, even if a non-negligible impact could be deduced through pre/post-event sample comparison. PMID:27448244

  14. Orbital changes, variation in solar activity and increased anthropogenic activities: controls on the Holocene flood frequency in the Lake Ledro area, Northern Italy

    NASA Astrophysics Data System (ADS)

    Vannière, B.; Magny, M.; Joannin, S.; Simonneau, A.; Wirth, S. B.; Hamann, Y.; Chapron, E.; Gilli, A.; Desmet, M.; Anselmetti, F. S.

    2013-05-01

    Two lacustrine sediment cores from Lake Ledro in northern Italy were studied to produce chronologies of flood events for the past 10 000 yr. For this purpose, we have developed an automatic method that objectively identifies the sedimentary imprint of river floods in the downstream lake basin. The method was based on colour data extracted from processed core photographs, and the count data were analysed to capture the flood signal. Flood frequency and reconstructed sedimentary dynamics were compared with lake-level changes and pollen inferred vegetation dynamics. The results suggest a record marked by low flood frequency during the early and middle Holocene (10 000-4500 cal BP). Only modest increases during short intervals are recorded at ca. 8000, 7500, and 7100 cal BP. After 4500-4000 cal BP, the record shows a shift toward increased flood frequency. With the exception of two short intervals around 2900-2500 and 1800-1400 cal BP, which show a slightly reduced number of floods, the trend of increasing flood frequency prevailed until the 20th century, reaching a maximum between the 16th and the 19th centuries. Brief-flood frequency increases recorded during the early and middle Holocene can be attributed to cold climatic oscillations. On a centennial time scale, major changes in flood frequency, such as those observed after ca. 4500/4000 and 500 cal BP, can be attributed to large-scale climatic changes such as the Neo-glacial and Little Ice Age, which are under orbital and possibly solar control. However, in the Bronze Age and during the Middle Ages and modern times, forest clearing and land use probably partially control the flood activity.

  15. Diagenetic controls on reservoir heterogeneity in Cretaceous Mishrif Formation in Zeta-1 well, offshore Dubai

    SciTech Connect

    Videtich, P.E.; McLimans, R.K.; Frank, H.J.

    1989-03-01

    The Zeta-1 well tested a thickened lens of the Cretaceous Mishrif Formation located east of Fateh field in offshore Dubai, United Arab Emirates. Initial petrographic study of Mishrif core showed it to be a homogeneous, mollusk-rudist packstone that apparently underwent similar diagenesis throughout. However, geochemical analyses of the ore identified a horizon where sharp changes in the elemental and stable carbon isotope compositions occur. The authors interpret those changes to be due to a discontinuity that divides the packstone into upper and lower units. There is a marked change in porosity coincident with the discontinuity from 13% in the lower unit to 24% in the upper unit. Evidence for oil migration at Zeta-1 is retained in the form of oil fluid inclusions trapped within calcite cements. However, oil inclusions are found only in cements near or above the discontinuity. This suggests that oil migration was confined to the upper packstone, whereas cementation continued unrestricted in the lower packstone, resulting in diminished porosity. The lack of an updip seal is the apparent reason why commercial quantities of oil did not accumulate at Zeta-1. Geothermometry studies of fluid inclusions entrapped in late blocky calcite spar that occludes much of the porosity indicate that the cement originated at depth from a high-density brine, consistent with the above scenario. Thus, the heterogeneity in the reservoir rock is related to early diagenesis, controlled in part by the discontinuity, deep burial cementation, and migration of oil.

  16. Dolomitization as control on reservoir quality - case study: Block III, Lake Maracaibo, Venezuela

    SciTech Connect

    Marquez, X.

    1989-03-01

    Paleocene carbonate sequences in Block III, Lake Maracaibo, have always been neglected, even though similar sequences such as those reported in the Smackover Formation, Gulf of Mexico coastal plain, USA, have shown great hydrocarbon potential. Core study in well VLC-950 shows that the Paleocene carbonate sequence consists of four oolitic facies: skeletal-oolitic rudstones (C1), oolitic packstones/grainstones(C2), oolitic grainstones (C3), and sandy oolitic grainstones (C4), all deposited in a prospective shallowing-upward carbonate sand sequence. Diagenetic processes such as micritization, calcite cementation, solution, dolomitization, and compaction have modified the original textures of these facies. It seems that the dolomitization has been the most important in controlling effective porosity. Dolomitization has occurred in the whole sequence. In C1, it is represented by isolated, fine, euhedral crystals. In C2, dolomitization has selectively replaced the oolites with a mosaic of coarse, anhedral crystals. In C3, dolomitization has selectively replaced the calcite cement and to a much lesser extent the oolites. Oolites not dolomitized have been selectively leached, resulting in well-developed oomoldic porosity that forms the reservoirs. In C4, dolomitization is minor, and it is represented by isolated, very fine crystals. Petrophysical analysis revealed that in C3 the porosity value is 19%, permeability is 1.21 md, and oil saturation is 80%; in C1, C2, and C4, porosity averages 4.3%, permeability is 0.06 md, and oil saturation is negligible.

  17. Orbital changes, variation in solar activity and increased anthropogenic activities: controls on the Holocene flood frequency in the Lake Ledro area, Northern Italy

    NASA Astrophysics Data System (ADS)

    Vannière, B.; Magny, M.; Joannin, S.; Simonneau, A.; Wirth, S. B.; Hamann, Y.; Chapron, E.; Gilli, A.; Desmet, M.; Anselmetti, F. S.

    2012-09-01

    Two lacustrine sediment cores from Lake Ledro in Northern Italy were studied to produce chronologies of flood events for the past 10 000 yr. For this purpose, we have developed an automatic method that objectively identifies the sedimentary imprint of river floods in the downstream lake basin. The automatic counting of flood deposits was based on colour data extracted from processed core photographs, and the count data were processed to capture the flood signal. Automatic quantification was compared with naked-eye counting. Counts were performed twice on the proximal and distal cores to provide an objective and reproducible record of flood frequency. Geophysical and geochemical analyses made it possible to distinguish event deposits from background sedimentation. Flood frequency and reconstructed sedimentary dynamics were compared with lake-level changes and pollen dynamics inferred from vegetation data. The data suggest a record marked by low flood frequency during the early and middle Holocene (10 000-4500 cal BP). Only modest increases during short intervals are recorded at ca. 8000, 7500, and 7100 cal BP. The last third of the Holocene is characterised by a shift toward increased flood frequency at ca. 4500-4000 cal BP. With the exception of two short intervals around 2900-2500 and 1800-1400 cal BP, which show a slightly reduced number of floods, the trend of increasing flood frequency prevailed until the 20th century, reaching a maximum between the 16th and the 19th centuries. Brief-flood frequency increases recorded during the early and middle Holocene can be attributed to cold climatic oscillations. On a centennial time scale, major changes in flood frequency, such as those observed at ca. 4500 and 500 cal BP, can be attributed to large-scale climatic changes such as the Neo-glacial and Little Ice Age, which are under orbital and possibly solar control. The role of climate as the main forcing factor in flood activity is supported by the lake-level records

  18. Flood control project selection using an interval type-2 entropy weight with interval type-2 fuzzy TOPSIS

    NASA Astrophysics Data System (ADS)

    Zamri, Nurnadiah; Abdullah, Lazim

    2014-06-01

    Flood control project is a complex issue which takes economic, social, environment and technical attributes into account. Selection of the best flood control project requires the consideration of conflicting quantitative and qualitative evaluation criteria. When decision-makers' judgment are under uncertainty, it is relatively difficult for them to provide exact numerical values. The interval type-2 fuzzy set (IT2FS) is a strong tool which can deal with the uncertainty case of subjective, incomplete, and vague information. Besides, it helps to solve for some situations where the information about criteria weights for alternatives is completely unknown. Therefore, this paper is adopted the information interval type-2 entropy concept into the weighting process of interval type-2 fuzzy TOPSIS. This entropy weight is believed can effectively balance the influence of uncertainty factors in evaluating attribute. Then, a modified ranking value is proposed in line with the interval type-2 entropy weight. Quantitative and qualitative factors that normally linked with flood control project are considered for ranking. Data in form of interval type-2 linguistic variables were collected from three authorised personnel of three Malaysian Government agencies. Study is considered for the whole of Malaysia. From the analysis, it shows that diversion scheme yielded the highest closeness coefficient at 0.4807. A ranking can be drawn using the magnitude of closeness coefficient. It was indicated that the diversion scheme recorded the first rank among five causes.

  19. Experience in operating the Bratsk Reservoir

    SciTech Connect

    Nazarov, A.V.

    1984-04-01

    The Bratsk reservoir is the largest in the USSR and second largest in the world. Initially, the reservoir was expected to be filled by the end of 1966. However, the actual filling was not completed until September of 1967. During filling and in the first years of operation it was constantly necessary to deal with floating timber in order to ensure normal operation of the hydrostation, navigation safety, conditions for fishery, and fulfillment of the sanitary requirements. During seasonal variations of the reservoir level about 160 sq km of the shore zone was subjected to variable flooding and waterlogging. Maximum erosion occurred on expanded stretches, and within their limits on slopes composed of loam and sand deposits. Within the narrows, where the banks are composed mainly of hard and soft rocks and wave action is weak, erosion is negligible. Wind setup and setdown cause maximum denivellation of the water surface. The maximum increase of the level during setup reaches 232 cm and the maximum decrease during setdown is 24 cm. Seiche oscillations with various amplitudes and periods are observed on the reservoir surface. The main uses of the complex are hydropower, water transport, timber floating, water supply, and fishery. For the successful development of the shores of reservoirs it is necessary to select the construction sites with consideration of possible occurrence of karstic and landslide processes; the construction of heavy structures requires special karst-control measures. 3 references, 3 figures, 1 table.

  20. 78 FR 43906 - Proposed Flood Hazard Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-22

    ... Riverside Riverside County Flood Control County. and Water Conservation District, 1995 Market Street... SECURITY Federal Emergency Management Agency Proposed Flood Hazard Determinations AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice. SUMMARY: Comments are requested on proposed flood...

  1. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas

    SciTech Connect

    Kerans, C.

    1988-10-01

    Petroleum production from restricted shelf carbonates of the Lower Ordovician Ellenburger group is commonly considered to have been a result of a pervasive, relatively homogeneous tectonic fracture system within the reservoir rock. However, regional facies and diagenetic (paleokarst) studies of Ellenburger strata, based on cores and wireline logs, have demonstrated that significant reservoir compartmentalization was caused by karst modification in the upper part of the unit. 19 figures.

  2. Reservoir controls on the occurrence and production of gas hydrates in nature

    USGS Publications Warehouse

    Collett, Timothy Scott

    2014-01-01

    modeling has shown that concentrated gas hydrate occurrences in sand reservoirs are conducive to existing well-based production technologies. The resource potential of gas hydrate accumulations in sand-dominated reservoirs have been assessed for several polar terrestrial basins. In 1995, the U.S. Geological Survey (USGS) assigned an in-place resource of 16.7 trillion cubic meters of gas for hydrates in sand-dominated reservoirs on the Alaska North Slope. In a more recent assessment, the USGS indicated that there are about 2.42 trillion cubic meters of technically recoverable gas resources within concentrated, sand-dominated, gas hydrate accumulations in northern Alaska. Estimates of the amount of in-place gas in the sand dominated gas hydrate accumulations of the Mackenzie Delta Beaufort Sea region of the Canadian arctic range from 1.0 to 10 trillion cubic meters of gas. Another prospective gas hydrate resources are those of moderate-to-high concentrations within sandstone reservoirs in marine environments. In 2008, the Bureau of Ocean Energy Management estimated that the Gulf of Mexico contains about 190 trillion cubic meters of gas in highly concentrated hydrate accumulations within sand reservoirs. In 2008, the Japan Oil, Gas and Metals National Corporation reported on a resource assessment of gas hydrates in which they estimated that the volume of gas within the hydrates of the eastern Nankai Trough at about 1.1 trillion cubic meters, with about half concentrated in sand reservoirs. Because conventional production technologies favor sand-dominated gas hydrate reservoirs, sand reservoirs are considered to be the most viable economic target for gas hydrate production and will be the prime focus of most future gas hydrate exploration and development projects.

  3. Microbial diversity in methanogenic hydrocarbon-degrading enrichment cultures isolated from a water-flooded oil reservoir (Dagang oil field, China)

    NASA Astrophysics Data System (ADS)

    Jiménez, Núria; Cai, Minmin; Straaten, Nontje; Yao, Jun; Richnow, Hans H.; Krüger, Martin

    2015-04-01

    Microbial transformation of oil to methane is one of the main degradation processes taking place in oil reservoirs, and it has important consequences as it negatively affects the quality and economic value of the oil. Nevertheless, methane could constitute a recovery method of carbon from exhausted reservoirs. Previous studies combining geochemical and isotopic analysis with molecular methods showed evidence for in situ methanogenic oil degradation in the Dagang oil field, China (Jiménez et al., 2012). However, the main key microbial players and the underlying mechanisms are still relatively unknown. In order to better characterize these processes and identify the main microorganisms involved, laboratory biodegradation experiments under methanogenic conditions were performed. Microcosms were inoculated with production and injection waters from the reservoir, and oil or 13C-labelled single hydrocarbons (e.g. n-hexadecane or 2-methylnaphthalene) were added as sole substrates. Indigenous microbiota were able to extensively degrade oil within months, depleting most of the n-alkanes in 200 days, and producing methane at a rate of 76 ± 6 µmol day-1 g-1 oil added. They could also produce heavy methane from 13C-labeled 2-methylnaphthalene, suggesting that further methanogenesis may occur from the aromatic and polyaromatic fractions of Dagang reservoir fluids. Microbial communities from oil and 2-methyl-naphthalene enrichment cultures were slightly different. Although, in both cases Deltaproteobacteria, mainly belonging to Syntrophobacterales (e.g. Syntrophobacter, Smithella or Syntrophus) and Clostridia, mostly Clostridiales, were among the most represented taxa, Gammaproteobacteria could be only identified in oil-degrading cultures. The proportion of Chloroflexi, exclusively belonging to Anaerolineales (e.g. Leptolinea, Bellilinea) was considerably higher in 2-methyl-naphthalene degrading cultures. Archaeal communities consisted almost exclusively of representatives of

  4. Assessing the impacts of reservoir operation to floodplain inundation by combining hydrological, reservoir management, and hydrodynamic models

    NASA Astrophysics Data System (ADS)

    Mateo, Cherry May; Hanasaki, Naota; Komori, Daisuke; Tanaka, Kenji; Kiguchi, Masashi; Champathong, Adisorn; Sukhapunnaphan, Thada; Yamazaki, Dai; Oki, Taikan

    2014-09-01

    A catastrophic flood event which caused massive economic losses occurred in Thailand, in 2011. Several studies have already been conducted to analyze the Thai floods, but none of them have assessed the impacts of reservoir operation on flood inundation. This study addresses this gap by combining physically based hydrological models to explicitly simulate the impacts of reservoir operation on flooding in the Chao Phraya River Basin, Thailand. H08, an integrated water resources model with a reservoir operation module, was combined with CaMa-Flood, a river routing model with representation of flood dynamics. The combined H08-CaMa model was applied to simulate and assess the historical and alternative reservoir operation rules in the two largest reservoirs in the basin. The combined H08-CaMa model effectively simulated the 2011 flood: regulated flows at a major gauging station have high daily NSE-coefficient of 92% as compared with observed discharge; spatiotemporal extent of simulated flood inundation match well with those of satellite observations. Simulation results show that through the operation of reservoirs in 2011, flood volume was reduced by 8.6 billion m3 and both depth and area of flooding were reduced by 40% on the average. Nonetheless, simple modifications in reservoir operation proved to further reduce the flood volume by 2.4 million m3 and the depth and area of flooding by 20% on the average. By modeling reservoir operation with a hydrodynamic model, a more realistic simulation of the 2011 Thai flood was made possible, and the potential of reducing flood inundation through improved reservoir management was quantified.

  5. Reservoir water level drawdown as a novel, substantial, and manageable control on methane release to the atmosphere

    NASA Astrophysics Data System (ADS)

    Harrison, J.; Deemer, B. R.; Birchfield, M. K.

    2014-12-01

    Reservoirs constitute a globally important source of atmospheric methane (CH4). Although it is reasonably well-established that hydrostatic and barometric pressure can influence rates of CH4 release from lake and tidal sediments, the relationship between water-level manipulation and CH4 release from man-made impoundments has not been quantified or characterized. Furthermore, cross-system controls on CH4 production and release to the atmosphere have not been established. We collected CH4 emission (diffusion and ebullition) data for 8 reservoirs in the U.S. Pacific Northwest that are subject to a range of trophic conditions and water level management regimes. Our aim was to: (1) characterize CH4 emissions from these systems, and (2) quantify effects of water level management and eutrophication on CH4 fluxes. Results indicate very high fluxes, in some cases the highest reported reservoir emission rates, and a strong correspondence between lake level reduction and CH4 emissions, including quantitatively important bursts of CH4 bubbling. In one reservoir, drawdown-associated CH4 fluxes accounted for over 25% of annual CH4 emissions in a period of just 16 days (4% of the year). Average CH4 ebullition rates in a reservoir managed for hydropower peaking were nearly three-fold higher than in a paired upstream reservoir managed to maintain a constant water level (528 mg CH4 m-2 d-1 and 187 mg CH4 m-2 d-1 respectively). Highest gas fluxes were observed during the water level drawdown component of the hydropower peaking cycle (14.3 g CH4 m-2 d-1). In addition we observe a strong, positive relationship between eutrophication (as indicated by surface Chl a concentrations) and CH4 production (r2 = 0.88; P<0.001) and between eutrophication and the sensitivity of CH4 emissions to drawdown (r2 = 0.84; P<0.001). This work suggests that manipulation of water levels can significantly affect CH4 emissions from reservoirs to the atmosphere, and that sampling programs that miss drawdown

  6. Use and Limitations of Electron Flood Gun Control of Surface Potential During XPS: Two Non-homogeneous Sample Types

    SciTech Connect

    Baer, Donald R.; Engelhard, Mark H.; Gaspar, Dan J.; Lea, Alan S.; Windisch, Charles F.

    2002-10-01

    The ability of charge compensation methods to control the surface potentials for two types of non-homogenous samples is examined. Results demonstrate that two newer types of charge compensation systems have improved performance in relation to some previous flood gun methods and reaffirm the concept that a primary objective of charge compensation is to find conditions for which the surface potential of the specimen is as uniform as possible. However, experiments involving both flood gun use and specimen grounding, demonstrate that peak broadening and shifting can occur when two (or more) potentials are present in the region of analysis. Finally, the ability of interface charge to shift specimen potentials and measured binding energies demonstrates fundamental limitations to the absolute accuracy of binding energy measurements, but also remind us that charging phenomena can be used to obtain important information about the sample.

  7. The effects of gravity on micellar-polymer flooding under North Sea conditions; A simulation study

    SciTech Connect

    Shook, M. ); Pope, G.A.; Sepehrnoori, K. )

    1991-01-01

    A three-dimensional, multiphase, compositional simulator has been used to investigate micellar-polymer flooding in heterogeneous reservoirs that exhibit large gravitational effects. A North Sea operator provided reservoir data incorporating the various conditions that cause gravity to become an important factor in flood design: large well spacing, large permeabilities, and light, low-viscosity oil. A series of sensitivity studies were conducted by varying the base case reservoir data to enhance the effects of gravity relative to the viscous driving force. In addition, the effects of mobility control were also examined through the addition/exclusion of polymer in the chemical slug and drive fluid. In all of the sensitivity studies conducted, it appeared that gravitational effects can be favorable in micellar-polymer flooding. Furthermore, for the reservoir description studied here, large gravity effects can mitigate the effects of poor vertical sweep caused by an unfavorable mobility ratio. This result suggests the possibility of designing a chemical flood without including polymer for sweep control.

  8. Flood vulnerability of the Karun river system and short-term mitigation measures

    NASA Astrophysics Data System (ADS)

    Heidari, Ali

    2013-04-01

    The Karun river basin has accommodated a large number of hydro projects, including reservoirs, hydropower plants (HPPs), water conveyance systems, and irrigation networks. Recent extreme floods in the basin have resulted in damage to the vulnerable floodplain areas and have devastated dam sites that are under construction. Structural and non-structural approaches were pursued to reduce flood damage in the region, after extreme floods in 2005 and 2006. Resistible cofferdams, along with an early flood forecasting system (EFFS) and emergency action plan (EAP), have been identified as short-term solutions in this paper. The EFFS incorporates a regional numerical weather forecast system, rainfall-runoff models, a reservoir flood control simulation model, flood routing, and two-dimensional inundation models. The maximum lead time of the forecast is 4 to 5 days, depending on the location of the sites, which is sufficient to evacuate the area and the possible damage centers. In addition to the EFFS, an EAP for dam break and extreme flood events was made after identifying hazardous zones and potential damage to vulnerable areas. Moreover, the EAP includes maps of hazardous zones and access maps to safe areas in the damage centers, mainly in the large cities of the floodplain area.

  9. Monitoring and research to describe geomorphic effects of the 2011 controlled flood on the Green River in the Canyon of Lodore, Dinosaur National Monument, Colorado and Utah

    USGS Publications Warehouse

    Mueller, Erich R.; Grams, Paul E.; Schmidt, John C.; Hazel, Joseph E., Jr.; Kaplinski, Matt; Alexander, Jason A.; Kohl, Keith

    2014-01-01

    In 2011, a large magnitude flow release from Flaming Gorge Reservoir, Wyoming and Utah, occurred in response to high snowpack in the middle Rocky Mountains. This was the third highest recorded discharge along the Green River downstream of Flaming Gorge Dam, Utah, since its initial closure in November 1962 and motivated a research effort to document effects of these flows on channel morphology and sedimentology at four long-term monitoring sites within the Canyon of Lodore in Dinosaur National Monument, Colorado and Utah. Data collected in September 2011 included raft-based bathymetric surveys, ground-based surveys of banks, channel cross sections and vegetation-plot locations, sand-bar stratigraphy, and painted rock recovery on gravel bars. As part of this surveying effort, Global Navigation Satellite System (GNSS) data were collected at benchmarks on the canyon rim and along the river corridor to establish a high-resolution survey control network. This survey control network allows for the collection of repeatable spatial and elevation data necessary for high accuracy geomorphic change detection. Nearly 10,000 ground survey points and more than 20,000 bathymetric points (at 1-meter resolution) were collected over a 5-day field campaign, allowing for the construction of reach-scale digital elevation models (DEMs). Additionally, we evaluated long-term geomorphic change at these sites using repeat topographic surveys of eight monumented cross sections at each of the four sites. Analysis of DEMs and channel cross sections show a spatially variable pattern of erosion and deposition, both within and between reaches. As much as 5 meters of scour occurred in pools downstream from flow constrictions, especially in channel segments where gravel bars were absent. By contrast, some channel cross sections were stable during the 2011 floods, and have shown almost no change in over a decade of monitoring. Partial mobility of gravel bars occurred, and although in some locations

  10. Prediction and exploitation of basement-controlled production trends in Piceance Basin fractured tight gas reservoirs: Results of an integrated analysis

    SciTech Connect

    Hoak, T.E.; Klawitter, A.L.

    1995-12-31

    The ability to delineate and accurately predict fracured reservoir conditions represents critical information necessary for field development srategies, and development of play concepts in less-developed areas. To demonstrate relationships between fracture-controlled production, stratigraphy and structural geology, the Piceance Basin is being used as the site for an integrated fracture detection and reservoir characterization program utilizing high-resolution aeromagnetics, seismic, and conventional subsurface structural and stratigraphic mapping. In the Piceance Basin, there are two primary controls on well performance. The first is reservoir thickness and the second is deliverability, a funciton of fracture permeability. Reservoir thickness is controlled by depositional systems whereas fracture permeability is controlled by tectonic deformation. In Rulison Field, a sidetrack well with a 142 foot difference in bottomhole location shows a 50% difference in net sandstone pay between the two wellbores. This intense variability underscores the difficulty of predicting sand geometries in the basin. Depositional systems analysis is important as a means of predicting reservoir quality and reservoir thickness, however, in the Piceance Basin, reservoir thickness and quality cannot be accurately predicted because of complex fluvial and paludal stratigraphy, In addition, stratigraphy does not exert the greatest control on production economics. Instead, fracture permeability is the predictable and most important variable for successful development programs. In support of this, the orientation of fracture-controlled production trends lie either orthogonal or oblique to depositional trends in White River Dome, Divide Creek, Shire Gulch, Plateau, Grand Valley, Parachute and Rulison fields.

  11. Field test of cosurfactant-enhanced alkaline flooding

    SciTech Connect

    Falls, A.H.; Thigpen, D.R.; Nelson, R.C.; Ciaston, J.W.; Lawson, J.B.; Good, P.A.; Ueber, R.C.; Shahin, G.T.

    1994-08-01

    To demonstrate that cosurfactant-enhanced alkaline flooding is viable in recovering waterflood residual oil from sandstone reservoirs in the near-offshore Gulf of Mexico, a series of tests is being conducted in the White Caste field, Louisiana. The strategy adopted was to pilot the technology in three stages: (1) a flood without polymer to prove features of the process unrelated to achieving mobility control, (2) a test of process polymer injectivity in the same reservoir, and (3) a full process demonstration in a shallower sand. The first phase of the pilot is described in this paper; pilot design, slug formulation, and operations are summarized and key responses are documented and interpreted. Ref. 2 describes the polymer injectivity test. The final pilot stage has not been initiated yet.

  12. Factors controlling reservoir quality in tertiary sandstones and their significance to geopressured geothermal production

    SciTech Connect

    Loucks, R.G.; Richmann, D.L.; Milliken, K.L.

    1981-01-01

    Variable intensity of diagenesis is the factor primarily responsible for contrasting regional reservoir quality of Tertiary sandstones from the upper and lower Texas coast. Detailed comparison of Frio sandstone from the Chocolate Bayou/Danbury Dome area, Brazoria County, and Vicksburg sandstones from the McAllen Ranch Field area, Hidalgo County, reveals that extent of diagenetic modification is most strongly influenced by (1) detrital mineralogy and (2) regional geothermal gradients. The regional reservoir quality of Frio sandstones from Brazoria County is far better than that characterizing Vicksburg sandstones from Hidalgo County, especially at depths suitable for geopressured geothermal energy production. However, in predicting reservoir quality on a site-specific basis, locally variable factors such as relative proportions for porosity types, pore geometry as related to permeability, and local depositional environment must also be considered. Even in an area of regionally favorable reservoir quality, such local factors can significantly affect reservoir quality and, hence, the geothermal production potential of a specific sandstone unit.

  13. Post waterflood CO2 miscible flood in light oil fluvial - dominated deltaic reservoirs. Technical progress report, October 1, 1994--December 30, 1994. 1st Quarter, fiscal year 1995

    SciTech Connect

    1994-01-15

    Production is averaging about 450 BOPD for the quarter. The fluctuation was primarily due to a temporary shutdown of CO{sub 2} delivery and maturing of the first WAG cycle. CO{sub 2} and water injection were reversed again in order to optimize changing yields and water cuts in the producing wells. Measured BHP was close to the anticipated value. A limited CO{sub 2} volume of 120 MMCF was injected to stimulate well Kuhn No. 6 to test the Huff-Puff process, since the well did not respond to CO{sub 2} injection from the main reservoir. The well will be placed on February 1, 1995. Total CO{sub 2} injection averaged this quarter about 8.8 MMCFD, including 3.6 MMCFD purchased CO{sub 2} from Cardox. The stratigraphy of the sand deposits is also discussed.

  14. Floods of November 1978 to March 1979 in Arizona and west-central New Mexico

    USGS Publications Warehouse

    Aldridge, Byron Neil; Hales, T.A.

    1984-01-01

    Severe flooding occurred in parts of the Little Colorado and Gila River basins as a result of a storm that occurred December 17-20, 1978. The central highlands received 3 to 10 inches of precipitation that was augmented by snowmelt to altitudes of 10,000 feet. The storm was preceded by extremely large amounts of rainfall and runoff in November and was followed by other periods of high runoff in January and March 1979. In some areas flood peaks in November, January, or March were higher than the peak of December 1978. At Winslow, the discharge of the Little Colorado River in December 1978 was the highest since at least 1952. The discharge of the Gila River above the San Francisco River was probably the highest since at least 1891, and in the Safford Valley, the peak was the highest since 1916. The Agua Fria River below Waddell Dam had the highest discharge since 1919. The flood of December 1978 caused 12 deaths and caused damage that was probably in excess of $150 million in Arizona and west-central New Mexico. Damage was estimated to be $51.8 million in Maricopa County, Arizona. Floods caused extensive agricultural damage along the Gila River in Virden Valley in New Mexico and in Duncan, York, and Safford Valleys in Arizona. Duncan, Arizona, was flooded with as much as 7 feet of water. The flood crest on the Gila River in December 1978 moved from Redrock, New Mexico, to Duncan, Arizona, in about 6 hours, which is more rapid than during other recent floods but is comparable to the travel-time recorded in 1941. Travel-time in the reach varies with discharge and is about 14 hours for discharges of 10,000 cubic feet per second and 5 hours for discharges of more than 40,000 cubic feet per second. Water-conservation reservoirs on the Gila, Salt, Verde, and Agua Fria Rivers and a flood-control reservoir on the Gila River had a major influence on the magnitude of floods downstream from the reservoirs. All runoff from the Gila River basin upstream from Coolidge Dam, Arizona

  15. Facies control on reservoir properties within a barrier island complex, Sparta Formation, Pointe Coupee Parish, Louisiana

    SciTech Connect

    Lemoine, R.C.; Moslow, T.F.; Ferrell, R.E.

    1988-02-01

    Analysis of conventional core, well logs, and petrophysical data has yielded an interpretation of the Sparta B sandstone in south-central Louisiana as a prograding barrier island complex. Four sedimentary facies possess reservoir potential: lower shoreface, upper shoreface, storm washover, and tidal-inlet channel sandstone facies. Distinct porosity and permeability values are associated with each reservoir facies. Predictable porosity and permeability trends associated with the Sparta B sandstone barrier island complex allows for identification of distinct fluid flow units within the sequence. In addition, individual sedimentary facies possess characteristic well log signatures; therefore, the geometry, thickness variability, and lateral continuity of each fluid flow unit can be determined and heterogeneities within the reservoir interval can be resolved.

  16. Assessing and optimising flood control options along the Arachthos river floodplain (Epirus, Greece)

    NASA Astrophysics Data System (ADS)

    Drosou, Athina; Dimitriadis, Panayiotis; Lykou, Archontia; Kossieris, Panagiotis; Tsoukalas, Ioannis; Efstratiadis, Andreas; Mamassis, Nikos

    2015-04-01

    We present a multi-criteria simulation-optimization framework for the optimal design and setting of flood protection structures along river banks. The methodology is tested in the lower course of the Arachthos River (Epirus, Greece), downstream of the hydroelectric dam of Pournari. The entire study area is very sensitive, particularly because the river crosses the urban area of Arta, which is located just after the dam. Moreover, extended agricultural areas that are crucial for the local economy are prone to floods. In the proposed methodology we investigate two conflicting criteria, i.e. the minimization of flood hazards (due to damages to urban infrastructures, crops, etc.) and the minimization of construction costs of the essential hydraulic structures (e.g. dikes). For the hydraulic simulation we examine two flood routing models, named 1D HEC-RAS and quasi-2D LISFLOOD, whereas the optimization is carried out through the Surrogate-Enhanced Evolutionary Annealing-Simplex (SE-EAS) algorithm that couples the strengths of surrogate modeling with the effectiveness and efficiency of the EAS method.

  17. Biocompetitive exclusion technology: A field system to control reservoir souring and increasing production

    SciTech Connect

    Sandbeck, K.A.; Hitzman, D.O.

    1995-12-31

    Biogenic formation of sulfide in reservoirs by Sulfate Reducing Bacteria (SRB) causes serious plugging, corrosion, and environmental safety problems. The production of sulfide can be decreased, and its concentration reduced, by the establishment and growth of an indigenous microbial population which results in a replacement of the SRB population. This approach to modify the reservoir ecology utilizing preexisting carbon sources coupled with the introduction of an alternate electron acceptor forms the basis of a new Biocompetitive Exclusion technology which has the potential to enhance oil recovery and decrease paraffin deposition and corrosion. Preliminary field results from an ongoing DOE-sponsored research program will be discussed.

  18. Geological and production characteristics of strandplain/barrier island reservoirs in the United States

    SciTech Connect

    Cole, E.L.; Fowler, M.; Jackson, S.; Madden, M.P.; Reeves, T.K.; Salamy, S.P.; Young, M.A.

    1994-12-01

    The Department of Energy`s (DOE`s) primary mission in the oil research program is to maximize the economically and environmentally sound recovery of oil from domestic reservoirs and to preserve access to this resource. The Oil Recovery Field Demonstration Program supports DOE`s mission through cost-shared demonstrations of improved Oil Recovery (IOR) processes and reservoir characterization methods. In the past 3 years, the DOE has issued Program Opportunity Notices (PONs) seeking cost-shared proposals for the three highest priority, geologically defined reservoir classes. The classes have been prioritized based on resource size and risk of abandonment. This document defines the geologic, reservoir, and production characteristics of the fourth reservoir class, strandplain/barrier islands. Knowledge of the geological factors and processes that control formation and preservation of reservoir deposits, external and internal reservoir heterogeneities, reservoir characterization methodology, and IOR process application can be used to increase production of the remaining oil-in-place (IOR) in Class 4 reservoirs. Knowledge of heterogeneities that inhibit or block fluid flow is particularly critical. Using the TORIS database of 330 of the largest strandplain/barrier island reservoirs and its predictive and economic models, the recovery potential which could result from future application of IOR technologies to Class 4 reservoirs was estimated to be between 1.0 and 4.3 billion barrels, depending on oil price and the level of technology advancement. The analysis indicated that this potential could be realized through (1) infill drilling alone and in combination with polymer flooding and profile modification, (2) chemical flooding (sufactant), and (3) thermal processes. Most of this future potential is in Texas, Oklahoma, and the Rocky Mountain region. Approximately two-thirds of the potentially recoverable resource is at risk of abandonment by the year 2000.

  19. Process-orientated simulation of tillage practices and land use change to optimize distributed flood control measures

    NASA Astrophysics Data System (ADS)

    Disse, M.; Rieger, W.

    2009-04-01

    Not only climate change affects hydrological systems but also land use change and agricultural tillage practises have an important impact on infiltration and runoff generation. In the last five to six decades monocropping, drainage and rectification of small rivers were carried out to optimize crop yields and economic benefits. However, in recent years more holistic and sustainable management concepts are required. The advantages of ecological management of land, soil and water resources are manifold: the biodiversity is higher, the buffer function of soils will be conserved and both low water and floods are positive affected. The target of the presented research project which is financed by the Bavarian environment agency, is to establish an optimal flood retention concept in a mesoscale catchment of 150 km² which emphasizes ecological flood measures like best tillage practices, small retention basins and renaturation of small rivers. To quantify the effects of these measures the water balance model WaSiM-ETH was used. The grid-based water flow and balance simulation model WaSiM-ETH is a well-established tool for investigating the spatial and temporal variability of hydrological processes in complex river basins. The model can be seen as a reasonable compromise between detailed physical basis and minimum data requirements (http://www.wasim.ch/en/index.html). WaSiM was coupled with a 2d-ground water model and an additional drainage tool. Different vegetation was parameterized with high spatial and temporal resolution. Additionally, future climate scenarios like the extension of vegetation periods were considered. The effectiveness of decentralized retention basins could be simulated by a new implemented see storage tool. The presentation will give quantitative results for different flood control measures. The pros and cons of physically based approaches in hydrological modelling will be discussed.

  20. 33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Texas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Texas. In the interest of flood control, the Lower Colorado River Authority (LCRA) shall operate the Marshall Ford Dam and... (Mansfield Dam and Lake Travis), Colorado River, Texas. 208.19 Section 208.19 Navigation and Navigable...

  1. [Mercury dynamics of several plants collected from the water-level fluctuation zone of the Three Gorges Reservoir area during flooding and its impact on water body].

    PubMed

    Zhang, Xiang; Zhang, Cheng; Sun, Rong-guo; Wang, Ding-yong

    2014-12-01

    Submerged plants are a major source for the abnormal elevation of methylmercury in reservoir. Several specific plants (Echinochloa crusgalli, Cynodondactylon and Corn stover) were collected and inundated in a simulated aquatic environment in the laboratory for investigating the mercury (Hg) dynamics in plants and the release process into water, aiming to find out the properties of Hg dynamics of plants under inundation conditions and its impact on water body in the Water-Level Fluctuation Zone of the Three Gorges Reservoir Area. The results showed that the contents of total mercury in several plants were in the range of 9. 21-12.07 ng x g(-1), and the percentage content of methylmercury (MeHg) was about 1%-2%. The content of total mercury (THg) in plants gradually decreased, by 35.81%-55.96%, whereas that of the dissolved mercury (DHg) increased sharply, by 103.23% -232.15%, which indicated an emission of Hg from plants to water in the process of decomposition. Furthermore, the state of inundation provided sufficient conditions for the methylation process in plants and therefore caused an increase of the content of methylmercury in the plant residues, which was 3.04-6.63 times as much as the initial content. The concentration of dissolved methylmercury (DMeHg) in the overlying water also increased significantly by 14.84- 16.05 times compared with the initial concentration. Meanwhile, the concentration of dissolved oxygen (DO) in the overlying water was significantly and negatively correlated with DMeHg. On the other hand, the concentration of dissolved organic carbon (DOC) in the overlying water was significantly and positively correlated with DMeHg. During the whole inundation period, the increase of DHg in the overlying water accounted for 41.74% -47.01% of the total amount of THg emission, and there was a negative correlation between the content of THg in plant residues and that of DHg in the overlying water. PMID:25826925

  2. A diagnostic assessment of evolutionary algorithms for multi-objective surface water reservoir control

    NASA Astrophysics Data System (ADS)

    Zatarain Salazar, Jazmin; Reed, Patrick M.; Herman, Jonathan D.; Giuliani, Matteo; Castelletti, Andrea

    2016-06-01

    Globally, the pressures of expanding populations, climate change, and increased energy demands are motivating significant investments in re-operationalizing existing reservoirs or designing operating policies for new ones. These challenges require an understanding of the tradeoffs that emerge across the complex suite of multi-sector demands in river basin systems. This study benchmarks our current capabilities to use Evolutionary Multi-Objective Direct Policy Search (EMODPS), a decision analytic framework in which reservoirs' candidate operating policies are represented using parameterized global approximators (e.g., radial basis functions) then those parameterized functions are optimized using multi-objective evolutionary algorithms to discover the Pareto approximate operating policies. We contribute a comprehensive diagnostic assessment of modern MOEAs' abilities to support EMODPS using the Conowingo reservoir in the Lower Susquehanna River Basin, Pennsylvania, USA. Our diagnostic results highlight that EMODPS can be very challenging for some modern MOEAs and that epsilon dominance, time-continuation, and auto-adaptive search are helpful for attaining high levels of performance. The ɛ-MOEA, the auto-adaptive Borg MOEA, and ɛ-NSGAII all yielded superior results for the six-objective Lower Susquehanna benchmarking test case. The top algorithms show low sensitivity to different MOEA parameterization choices and high algorithmic reliability in attaining consistent results for different random MOEA trials. Overall, EMODPS poses a promising method for discovering key reservoir management tradeoffs; however algorithmic choice remains a key concern for problems of increasing complexity.

  3. Controls on nitrous oxide production and consumption in reservoirs of the Ohio River Basin

    EPA Science Inventory

    Aquatic ecosystems are a globally significant source of nitrous oxide (N2O), a potent greenhouse gas, but estimates are largely based on studies conducted in streams and rivers with relatively less known about N2O dynamics in lakes and reservoirs. Due to long water residence tim...

  4. Post waterflood CO{sub 2} miscible flood in light oil, fluvial-dominated deltaic reservoirs. 3rd Quarterly report, April 1, 1994--June 30, 1994

    SciTech Connect

    Not Available

    1994-07-15

    Production from the Port Neches CO{sub 2} continue to improve. five wells responded to CO{sub 2} injection and currently are flowing with the exception of well No. 6, which has been placed on gas lift to draw the CO{sub 2} to the vicinity. Current production is about 400 BOPD from the five producing wells. Total CO{sub 2} injection is averaging 10 MMCFD, including 4 MMCFD purchased from Cardox and 6 MMCFD of recycled gas. Reservoir pressure increased from 2697 psi in May, to 2890 psi in June due to over-injection. An additional water injection pump was installed to handle the increasing volume of produced water. Also a workover was performed on Well No. 33 to take out the gas lift valves and eliminate communication. Two papers were presented at the SPE/DOE symposium that was held in Tulsa this April. The screening model has been released to the DOE and was made public during the month of May.

  5. Effects of 500 years of eutrophication and flooding control on lowland lake development

    NASA Astrophysics Data System (ADS)

    Kirilova, E.; van Hardenbroek, M.; Heiri, O.; Cremer, H.; Lotter, A. F.

    2009-04-01

    Nutrient enrichment and the ecology of surface waters have been intensively studied in lowland regions. However, detailed palaeolimnological reconstructions of the trophic and flooding history of floodplain lakes are still rare. In the Netherlands dike-breaches caused by high floods of the river Rhine formed a new type of lake since the Middle Ages. These dike-breach lakes were strongly impacted by the development of channel systems in their catchment, agriculture, and repeated flooding events. Here we present a multiproxy palaeolimnological study of past nutrient loading and ecology of the dike-breach lake De Waay which is located on the Rhine-Meuse delta (The Netherlands). The lake was created in A.D. 1496 as a result of damage done to a dike by floating ice and the subsequent dike-breach due to a flooding event. A sediment core of 11.5 m was recovered from Lake De Waay and diatoms, Cladocera, and geochemistry were analyzed in the sediment. From the beginning of the lake's existence to the end of the 18th century diatom-inferred total phosphorus (TP) concentrations were above 300 µg/l, suggesting hypertrophic conditions. Cladoceran assemblages reflect the lake's pioneer stage and suggest a lack of rooted aquatic macrophytes resulting from low water-transparency, possibly caused by frequent floods. Until the late 18th century floods occurred regularly in the area, as shown by the elevated Ti values in the sediments, indicative of high erosion from the floodplain and runoff from the surrounding agricultural catchment. This caused the exceptionally high sedimentation rates and elevated nutrient contents of the lake waters. Since the beginning of the 19th century sewage input and flooding frequency were strongly reduced by the construction of new ditches, canals, and dikes. The improved sewage and dike systems are reflected by decreased TP concentrations of 40-150 µg/l. The increased stability of littoral habitats led to an increased diversity in the Cladocera

  6. Assessment of aquatic plants in the reservoirs of AES-tietê and development of an integrated control model for the most important species.

    PubMed

    Velini, Edivaldo Domingues; Galo, Maria Lourdes B T; Carvalho, Fernando Tadeu; Martins, Dagoberto; Cavenaghi, Anderson Luis; Trindade, Maria Lúcia Bueno; Bravin, Luis Fernando N; Negrisoli, Eduardo; Antuniassi, Ulisses Rocha; Simionato, José L A; Santos, Silvio C A

    2005-01-01

    The general objective of this work was to develop a monitoring and management model for aquatic plants that could be used in reservoir cascades in Brazil, using the reservoirs of AES-Tietê as a study case. The investigations were carried out at the reservoirs of Barra-Bonita, Bariri, Ibitinga, Promissão, and Nova-Avanhandava, located in the Tietê River Basin; Agua Vermelha, located in the Grande River Basin; Caconde, Limoeiro, and Euclides da Cunha, which are part of the Pardo River Basin; and the Mogi-Guaçu reservoir, which belongs to the Mogi-Guaçu River basin. The main products of this work were: development of techniques using satellite-generated images for monitoring and planning aquatic plant control; planning and construction of a boat to move coating plant masses and an airboat equipped with a DGPS navigation and application flow control system. Results allowed to conclude that the occurrence of all types of aquatic plants is directly associated with sedimentation process and, consequently, with nutrient and light availability. Reservoirs placed at the beginning of cascades are more subject to sedimentation and occurrence of marginal, floating and emerged plants, and are the priority when it comes to controlling these plants, since they provide a supply of weeds for the other reservoirs. Reservoirs placed downstream show smaller amounts of water-suspended solids, with greater transmission of light and occurrence of submerged plants. PMID:15656166

  7. Sequence stratigraphic controls on reservoir characterization and architecture: case study of the Messinian Abu Madi incised-valley fill, Egypt

    NASA Astrophysics Data System (ADS)

    Abdel-Fattah, Mohamed I.; Slatt, Roger M.

    2013-12-01

    Understanding sequence stratigraphy architecture in the incised-valley is a crucial step to understanding the effect of relative sea level changes on reservoir characterization and architecture. This paper presents a sequence stratigraphic framework of the incised-valley strata within the late Messinian Abu Madi Formation based on seismic and borehole data. Analysis of sand-body distribution reveals that fluvial channel sandstones in the Abu Madi Formation in the Baltim Fields, offshore Nile Delta, Egypt, are not randomly distributed but are predictable in their spatial and stratigraphic position. Elucidation of the distribution of sandstones in the Abu Madi incised-valley fill within a sequence stratigraphic framework allows a better understanding of their characterization and architecture during burial. Strata of the Abu Madi Formation are interpreted to comprise two sequences, which are the most complex stratigraphically; their deposits comprise a complex incised valley fill. The lower sequence (SQ1) consists of a thick incised valley-fill of a Lowstand Systems Tract (LST1)) overlain by a Transgressive Systems Tract (TST1) and Highstand Systems Tract (HST1). The upper sequence (SQ2) contains channel-fill and is interpreted as a LST2 which has a thin sandstone channel deposits. Above this, channel-fill sandstone and related strata with tidal influence delineates the base of TST2, which is overlain by a HST2. Gas reservoirs of the Abu Madi Formation (present-day depth ˜3552 m), the Baltim Fields, Egypt, consist of fluvial lowstand systems tract (LST) sandstones deposited in an incised valley. LST sandstones have a wide range of porosity (15 to 28%) and permeability (1 to 5080mD), which reflect both depositional facies and diagenetic controls. This work demonstrates the value of constraining and evaluating the impact of sequence stratigraphic distribution on reservoir characterization and architecture in incised-valley deposits, and thus has an important impact on

  8. Distillation Column Flooding Predictor

    SciTech Connect

    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

  9. Subduction-modified oceanic crust mixed with a depleted mantle reservoir in the sources of the Karoo continental flood basalt province

    NASA Astrophysics Data System (ADS)

    Heinonen, Jussi S.; Carlson, Richard W.; Riley, Teal R.; Luttinen, Arto V.; Horan, Mary F.

    2014-05-01

    The great majority of continental flood basalts (CFBs) have a marked lithospheric geochemical signature, suggesting derivation from the continental lithosphere, or contamination by it. Here we present new Pb and Os isotopic data and review previously published major element, trace element, mineral chemical, and Sr and Nd isotopic data for geochemically unusual mafic and ultramafic dikes located in the Antarctic segment (Ahlmannryggen, western Dronning Maud Land) of the Karoo CFB province. Some of the dikes show evidence of minor contamination with continental crust, but the least contaminated dikes exhibit depleted mantle - like initial ɛNd (+9) and 187Os/188Os (0.1244-0.1251) at 180 Ma. In contrast, their initial Sr and Pb isotopic compositions (87Sr/86Sr = 0.7035-0.7062, 206Pb/204Pb = 18.2-18.4, 207Pb/204Pb = 15.49-15.52, 208Pb/204Pb = 37.7-37.9 at 180 Ma) are more enriched than expected for depleted mantle, and the major element and mineral chemical evidence indicate contribution from (recycled) pyroxenite sources. Our Sr, Nd, Pb, and Os isotopic and trace element modeling indicate mixed peridotite-pyroxenite sources that contain ˜10-30% of seawater-altered and subduction-modified MORB with a recycling age of less than 1.0 Ga entrained in a depleted Os-rich peridotite matrix. Such a source would explain the unusual combination of elevated initial 87Sr/86Sr and Pb isotopic ratios and relative depletion in LILE, U, Th, Pb and LREE, high initial ɛNd, and low initial 187Os/188Os. Although the sources of the dikes probably did not play a major part in the generation of the Karoo CFBs in general, different kind of recycled source components (e.g., sediment-influenced) would be more difficult to distinguish from lithospheric CFB geochemical signatures. In addition to underlying continental lithosphere, the involvement of recycled sources in causing the apparent lithospheric geochemical affinity of CFBs should thus be carefully assessed in every case.

  10. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas: Discussion

    SciTech Connect

    Mazzullo, S.J. )

    1990-07-01

    A discussion is presented on a paper by Charles Kerans (AAPG Bull. 1988). The paper dealt with karst-associated porosity and hydrocarbon reservoir heterogenity in Ellengurger (Lower Ordovician) carbonates in the Permian basin of west Texas. The purpose of this paper is not to dispute the model presented by Kerans, but instead to present some alternative models of reservoir occurrence that are not considered in his paper and that are also widely applicable to the Ellenburger and correlative strata in the Mid-Continent. The discussion is based on regional lithostratigraphy and subsurface mapping studies of the Ellenburger in the southern Midland basin, specifically in Irion, Reagan, Crockett, Schleicher, and Sterling counties (Texas).

  11. Hydrogeologic controls on induced seismicity in crystalline basement rocks due to fluid injection into basal reservoirs.

    PubMed

    Zhang, Yipeng; Person, Mark; Rupp, John; Ellett, Kevin; Celia, Michael A; Gable, Carl W; Bowen, Brenda; Evans, James; Bandilla, Karl; Mozley, Peter; Dewers, Thomas; Elliot, Thomas

    2013-01-01

    A series of Mb 3.8-5.5 induced seismic events in the midcontinent region, United States, resulted from injection of fluid either into a basal sedimentary reservoir with no underlying confining unit or directly into the underlying crystalline basement complex. The earthquakes probably occurred along faults that were likely critically stressed within the crystalline basement. These faults were located at a considerable distance (up to 10 km) from the injection wells and head increases at the hypocenters were likely relatively small (∼70-150 m). We present a suite of simulations that use a simple hydrogeologic-geomechanical model to assess what hydrogeologic conditions promote or deter induced seismic events within the crystalline basement across the midcontinent. The presence of a confining unit beneath the injection reservoir horizon had the single largest effect in preventing induced seismicity within the underlying crystalline basement. For a crystalline basement having a permeability of 2 × 10(-17)  m(2) and specific storage coefficient of 10(-7) /m, injection at a rate of 5455 m(3) /d into the basal aquifer with no underlying basal seal over 10 years resulted in probable brittle failure to depths of about 0.6 km below the injection reservoir. Including a permeable (kz  = 10(-13)  m(2) ) Precambrian normal fault, located 20 m from the injection well, increased the depth of the failure region below the reservoir to 3 km. For a large permeability contrast between a Precambrian thrust fault (10(-12)  m(2) ) and the surrounding crystalline basement (10(-18)  m(2) ), the failure region can extend laterally 10 km away from the injection well. PMID:23745958

  12. Interface control volume finite element method for modelling multi-phase fluid flow in highly heterogeneous and fractured reservoirs

    NASA Astrophysics Data System (ADS)

    Abushaikha, Ahmad S.; Blunt, Martin J.; Gosselin, Olivier R.; Pain, Christopher C.; Jackson, Matthew D.

    2015-10-01

    We present a new control volume finite element method that improves the modelling of multi-phase fluid flow in highly heterogeneous and fractured reservoirs, called the Interface Control Volume Finite Element (ICVFE) method. The method drastically decreases the smearing effects in other CVFE methods, while being mass conservative and numerically consistent. The pressure is computed at the interfaces of elements, and the control volumes are constructed around them, instead of at the elements' vertices. This assures that a control volume straddles, at most, two elements, which decreases the fluid smearing between neighbouring elements when large variations in their material properties are present. Lowest order Raviart-Thomas vectorial basis functions are used for the pressure calculation and first-order Courant basis functions are used to compute fluxes. The method is a combination of Mixed Hybrid Finite Element (MHFE) and CVFE methods. Its accuracy and convergence are tested using three dimensional tetrahedron elements to represent heterogeneous reservoirs. Our new approach is shown to be more accurate than current CVFE methods.

  13. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations; 1991 Annual Report.

    SciTech Connect

    Griffith, Janelle R.; McDowell, Amy C.; Scholz, Allan T.

    1995-08-01

    The purpose of this study was to collect biological data from Lake Roosevelt to be used in the design of a computer model that would predict biological responses to reservoir operations as part of the System Operation Review program. Major components of the Lake Roosevelt model included: quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times. This report summarized the data collected on Lake Roosevelt for 1991 and includes limnological, zooplankton, benthic macroinvertebrate, fishery, and reservoir operation data. Discussions cover reservoir operation affect upon zooplankton, benthic macroinvertebrates, and fish. Reservoir operations brought reservoir elevations to a low of 1,221.7 in April, the result of power operations and a flood control shift from Dworshak Dam, in Idaho, to Grand Coulee Dam. Water retention times were correspondingly low reaching a minimum of 14.7 days on April 27th.

  14. Real-Time Flood Estimation by Using Radar Rainfall data and Distributed Rainfall-Runoff Model

    NASA Astrophysics Data System (ADS)

    Yu, P.; Chou, J.; Chiu, Y.; Yang, T.; Kuo, C.

    2011-12-01

    This study aims to establish a flood prediction model in Dajia River by using a grid-based distributed rainfall-runoff model (GDRRM) combined with the predicted QPESUMS radar rainfalls. Flood disasters caused damage to human and property. A proper flood prediction model can provide warning messages against disasters. Since the radar rainfall technology has been developed for years, it has the ability to represent the precipitation in each location. Coupling the real-time radar rainfall with the distributed rainfall-runoff model, it can be used to provide the probable flow in downstream. The study area, Dajia River basin, is located in central Taiwan. The river flow is mainly controlled by two major reservoirs, Shih-Kang Dam in downstream and Te-Chi Reservoir in upstream. Thus, three components are considered for establishing the flood prediction model. The first one is the application of radar rainfalls. The real-time and predicted (1-3hr ahead) radar rainfall data provided by the Central Weather Bureau, Taiwan were set as the input data. It can represent the actual distributed rainfalls of the basin. The second one is the estimation of reservoir inflow by using a GDRRM. The basin was divided into 1234 regular grids (1km by 1km) to exhibit the heterogeneity in the watershed. The parameters of GDRRM were generated by using DEM, Formosat-2 satellite image and soil map to represent the actual geography and physiography of each grid. With the input of real-time and predicted radar rainfall data, the inflow of Te-Chi Reservoir and Shih-Kang Dam can be calculated by using two GDRRMs respectively. The third one is the operation rules of reservoir used for simulating the outflow of the reservoirs during the flow simulation. Then, the downstream (Shih-Kang Dam) GDRRM coupled with the operation rules was used to calculate the outflow of the Te-Chi Reservoir. Thus, the flood can be predicted in advance during typhoon period. The results revealed that the flood prediction

  15. Relative Importance of Beaver and Low Recurrence Interval Floods in Controlling Water Table Position in Mountain Riparian Wetlands

    NASA Astrophysics Data System (ADS)

    Westbrook, C. J.; Cooper, D. J.; Baker, B. W.; MacDonald, L. H.

    2004-05-01

    Spring peak runoff and beaver dams alter stream stage, and therefore control the position of the water table in riparian wetlands. This study poses the hypothesis that beaver, by building cross-channel dams, can maintain higher groundwater levels in riparian wetlands than low recurrence interval floods. Water level data from approximately 200 wells were used to create potentiometric maps of water levels for the summers of 2002 and 2003 along a 900 m reach the Colorado River in Rocky Mountain National Park, Colorado. The lowest discharge on record occurred in 2002 while the second highest peak discharge in 49 years occurred in 2003 because of an above average snowpack and a rapid snowmelt. A 2 m tall beaver dam was present the first summer and absent the following summer. The beaver dam inundated approximately 12 ha, while overbank flooding from the 2003 peak flow inundated only 5.5 ha of the riparian area. Agglomerative cluster analysis identified the wells affected by the beaver dam. In 2002, water levels in wells affected by the beaver dam were constant and near the ground surface, while in 2003 the water levels declined rapidly after peak runoff. These results suggest that beaver activities, while seldom quantified, are important in controlling water table position in mountain riparian wetlands.

  16. Flood magnitude frequency and lithologic control on bedrock river incision in post-orogenic terrain

    NASA Astrophysics Data System (ADS)

    Jansen, John D.

    2006-12-01

    Mixed bedrock-alluvial rivers-bedrock channels lined with a discontinuous alluvial cover-are key agents in the shaping of mountain belt topography by bedrock fluvial incision. Whereas much research focuses upon the erosional dynamics of such rivers in the context of rapidly uplifting orogenic landscapes, the present study investigates river incision processes in a post-orogenic (cratonic) landscape undergoing extremely low rates of incision (< 5 m/Ma). River incision processes are examined as a function of substrate lithology and the magnitude and frequency of formative flows along Sandy Creek gorge, a mixed bedrock-alluvial stream in arid SE-central Australia. Incision is focused along a bedrock channel with a partial alluvial cover arranged into riffle-pool macrobedforms that reflect interactions between rock structure and large-flood hydraulics. Variations in channel width and gradient determine longitudinal trends in mean shear stress ( τb) and therefore also patterns of sediment transport and deposition. A steep and narrow, non-propagating knickzone (with 5% alluvial cover) coincides with a resistant quartzite unit that subdivides the gorge into three reaches according to different rock erodibility and channel morphology. The three reaches also separate distinct erosional styles: bedrock plucking (i.e. detachment-limited erosion) prevails along the knickzone, whereas along the upper and lower gorge rock incision is dependent upon large formative floods exceeding critical erosion thresholds ( τc) for coarse boulder deposits that line 70% of the channel thalweg (i.e. transport-limited erosion). The mobility of coarse bed materials (up to 2 m diameter) during late Holocene palaeofloods of known magnitude and age is evaluated using step-backwater flow modelling in conjunction with two selective entrainment equations. A new approach for quantifying the formative flood magnitude in mixed bedrock-alluvial rivers is described here based on the mobility of a key

  17. Origin of Columbia River flood basalt controlled by propagating rupture of the Farallon slab.

    PubMed

    Liu, Lijun; Stegman, Dave R

    2012-02-16

    The origin of the Steens-Columbia River (SCR) flood basalts, which is presumed to be the onset of Yellowstone volcanism, has remained controversial, with the proposed conceptual models involving either a mantle plume or back-arc processes. Recent tomographic inversions based on the USArray data reveal unprecedented detail of upper-mantle structures of the western USA and tightly constrain geodynamic models simulating Farallon subduction, which has been proposed to influence the Yellowstone volcanism. Here we show that the best-fitting geodynamic model depicts an episode of slab tearing about 17 million years ago under eastern Oregon, where an associated sub-slab asthenospheric upwelling thermally erodes the Farallon slab, leading to formation of a slab gap at shallow depth. Driven by a gradient of dynamic pressure, the tear ruptured quickly north and south and within about two million years covering a distance of around 900 kilometres along all of eastern Oregon and northern Nevada. This tear would be consistent with the occurrence of major volcanic dikes during the SCR-Northern Nevada Rift flood basalt event both in space and time. The model predicts a petrogenetic sequence for the flood basalt with sources of melt starting from the base of the slab, at first remelting oceanic lithosphere and then evolving upwards, ending with remelting of oceanic crust. Such a progression helps to reconcile the existing controversies on the interpretation of SCR geochemistry and the involvement of the putative Yellowstone plume. Our study suggests a new mechanism for the formation of large igneous provinces. PMID:22337059

  18. Pakistan Flooding

    Atmospheric Science Data Center

    2013-04-16

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

  19. Research Spotlight: The varying life expectancies of American reservoirs

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2011-04-01

    Tasked with controlling floods, coping through droughts, generating electricity, maintaining the flow of drinking water, preserving species' habitats, and managing the local environment, the United States' large-scale freshwater management system is important. Unfortunately, as sediment is washed from river basins to reservoirs, the persistent addition of material eats away at a reservoir's capacity and, consequently, its useful life expectancy. Understanding the integrity of the reservoir system is particularly important, with climate projections anticipating warmer, drier conditions for some parts of the country. Using a database of sedimentation surveys conducted between 1775 and 1993, Graf et al. calculate the life expectancies of many of the nation's reservoirs. They find that although most of the country's large reservoirs were built between 1950 and 1960, they have a wide range of expiration dates. They find that most large reservoirs, those with capacities greater than 1.2 cubic kilometers (0.29 cubic mile), have useful life expectancies ranging from 200 to more than 1000 years, with the lowest average life expectancy in the interior West. (Water Resources Research, doi:10.1029/2009WR008836, 2010)

  20. Distillation Column Flooding Predictor

    SciTech Connect

    2002-02-01

    This factsheet describes a research project whose goal is to develop the flooding predictor, an advanced process control strategy, into a universally useable tool that will maximize the separation yield of a distillation column.

  1. A microfluidic reciprocating intracochlear drug delivery system with reservoir and active dose control

    PubMed Central

    Kim, Ernest S.; Gustenhoven, Erich; Mescher, Mark J.; Pararas, Erin E. Leary; Smith, Kim A.; Spencer, Abigail J.; Tandon, Vishal; Borenstein, Jeffrey T.; Fiering, Jason

    2014-01-01

    Reciprocating microfluidic drug delivery, as compared to steady or pulsed infusion, has unique features which may be advantageous in many therapeutic applications. We have previously described a device, designed for wearable use in small animal models, which periodically infuses then withdraws a sub-microliter volume of drug solution to and from the endogenous fluid of the inner ear. This delivery approach results in zero net volume of liquid transfer while enabling mass transport of compounds to the cochlea by means of diffusion and mixing. We report here on an advanced wearable delivery system aimed at further miniaturization and complex dose protocols. Enhancements to the system include the incorporation of a planar micropump to generate reciprocating flow and a novel drug reservoir which maintains zero net volume delivery and permits programmable modulation of the drug concentration in the infused bolus. The reciprocating pump is fabricated from laminated polymer films and employs a miniature electromagnetic actuator to meet the size and weight requirements of a head-mounted in vivo guinea pig testing system. The reservoir comprises a long microchannel in series with a micropump, connected in parallel with the reciprocating flow network. We characterized in vitro the response and repeatability of the planar pump and compared the results with a lumped element simulation. We also characterized the performance of the reservoir, including repeatability of dosing and range of dose modulation. Acute in vivo experiments were performed in which the reciprocating pump was used to deliver a test compound to the cochlea of anesthetized guinea pigs to evaluate short-term safety and efficacy of the system. These advances are key steps toward realization of an implantable device for long-term therapeutic applications in humans. PMID:24302432

  2. Tectonic controls on fracture permeability in a geothermal reservoir at Dixie Valley, Nevada

    SciTech Connect

    Hickman, S.; Zoback, M.

    1998-08-01

    To help determine the nature and origins of permeability variations within a fault-hosted geothermal reservoir at Dixie Valley, Nevada, the authors conducted borehole televiewer logging and hydraulic fracturing stress measurements in six wells drilled into the Stillwater fault zone at depths of 2--3 km. Televiewer logs from wells penetrating the highly permeable portion of the fault zone revealed extensive drilling-induced tensile fractures. As the Stillwater fault at this location dips S45{degree}E at {approximately} 53{degree} it is nearly at the optimal orientation for normal faulting in the current stress field. Hydraulic fracturing tests from these permeable wells show that the magnitude of S{sub hmin} is very low relative to the vertical stress S{sub v}. Similar measurements conducted in two wells penetrating a relatively impermeable segment of the Stillwater fault zone 8 and 20 km southwest of the producing geothermal reservoir indicate that the orientation of S{sub hmin} is S20{degree}E and S41{degree}E, respectively, with S{sub hmin}/S{sub v} ranging from 0.55--0.64 at depths of 1.9--2.2 km. This stress orientation is near optimal for normal faulting on the Stillwater fault in the northernmost non-producing well, but {approximately} 40{degree} rotated from the optimal orientation for normal faulting in the southernmost well. The observation that borehole breakouts were present in these nonproducing wells, but absent in wells drilled into the permeable main reservoir, indicates a significant increase in the magnitude of maximum horizontal principal stress, S{sub Hmax}, in going from the producing to non-producing segments of the fault. The increase in S{sub Hmaz}, coupled with elevated S{sub hmin}/S{sub v} values and a misorientation of the Stillwater fault zone with respect to the principal stress directions, leads to a decrease in the proximity of the fault zone to Coulomb failure. This suggests that a necessary condition for high reservoir permeability

  3. Biological souring and mitigation in oil reservoirs.

    PubMed

    Gieg, Lisa M; Jack, Tom R; Foght, Julia M

    2011-10-01

    Souring in oil field systems is most commonly due to the action of sulfate-reducing prokaryotes, a diverse group of anaerobic microorganisms that respire sulfate and produce sulfide (the key souring agent) while oxidizing diverse electron donors. Such biological sulfide production is a detrimental, widespread phenomenon in the petroleum industry, occurring within oil reservoirs or in topside processing facilities, under low- and high-temperature conditions, and in onshore or offshore operations. Sulfate reducers can exist either indigenously in deep subsurface reservoirs or can be "inoculated" into a reservoir system during oil field development (e.g., via drilling operations) or during the oil production phase. In the latter, souring most commonly occurs during water flooding, a secondary recovery strategy wherein water is injected to re-pressurize the reservoir and sweep the oil towards production wells to extend the production life of an oil field. The water source and type of production operation can provide multiple components such as sulfate, labile carbon sources, and sulfate-reducing communities that influence whether oil field souring occurs. Souring can be controlled by biocides, which can non-specifically suppress microbial populations, and by the addition of nitrate (and/or nitrite) that directly impacts the sulfate-reducing population by numerous competitive or inhibitory mechanisms. In this review, we report on the diversity of sulfate reducers associated with oil reservoirs, approaches for determining their presence and effects, the factors that control souring, and the approaches (along with the current understanding of their underlying mechanisms) that may be used to successfully mitigate souring in low-temperature and high-temperature oil field operations. PMID:21858492

  4. Spatial and temporal distribution of mercury in Caballo and Elephant Butte Reservoirs, Sierra County, New Mexico

    SciTech Connect

    Caldwell, C.A.; Canavan, M.

    1998-05-01

    Caballo and Elephant Butte reservoirs are located in south-central New Mexico of the Rio Grande. The reservoirs are managed together for flood control and irrigation. As a result, Caballo Reservoir undergoes seasonal water volume fluctuations creating large littoral or shallow areas. Water and sediment samples were collected monthly for one year (July 1995 to June 1996) in Caballo Reservoir to examine spatial and temporal variability of total mercury (THg) and monomethylmercury (MMHg). Concentrations of THg and MMHg were greatest in water and sediments at the site located in the seasonally flooded area (Palomas) compared to five sites in deep water. In contrast, concentrations of MMHg from the five site were at or below 1.0 ng/g. The percentages of THg in the MMHg form was greatest in sediment collected from the Palomas site from September 1995 to June 1996 (5.4-33.8%) compared to sediment from the five sites in deep water. By October 1995, a site above Caballo Reservoir in the Rio Grande had greater concentrations of dissolved MMHg (0.508 ng/L) than the Palomas site (0.411 ng/L). The presence of a potential source of contamination upriver, in addition to a series of unrelated events (fire and late summer rains), precipitated a second study from July 1996 to June 1997. Thus, the second year was initiated to determine the sources of THg and MMHg entering Caballo Reservoir.

  5. Modeling Reservoir-River Networks in Support of Optimizing Seasonal-Scale Reservoir Operations

    NASA Astrophysics Data System (ADS)

    Villa, D. L.; Lowry, T. S.; Bier, A.; Barco, J.; Sun, A.

    2011-12-01

    HydroSCOPE (Hydropower Seasonal Concurrent Optimization of Power and the Environment) is a seasonal time-scale tool for scenario analysis and optimization of reservoir-river networks. Developed in MATLAB, HydroSCOPE is an object-oriented model that simulates basin-scale dynamics with an objective of optimizing reservoir operations to maximize revenue from power generation, reliability in the water supply, environmental performance, and flood control. HydroSCOPE is part of a larger toolset that is being developed through a Department of Energy multi-laboratory project. This project's goal is to provide conventional hydropower decision makers with better information to execute their day-ahead and seasonal operations and planning activities by integrating water balance and operational dynamics across a wide range of spatial and temporal scales. This presentation details the modeling approach and functionality of HydroSCOPE. HydroSCOPE consists of a river-reservoir network model and an optimization routine. The river-reservoir network model simulates the heat and water balance of river-reservoir networks for time-scales up to one year. The optimization routine software, DAKOTA (Design Analysis Kit for Optimization and Terascale Applications - dakota.sandia.gov), is seamlessly linked to the network model and is used to optimize daily volumetric releases from the reservoirs to best meet a set of user-defined constraints, such as maximizing revenue while minimizing environmental violations. The network model uses 1-D approximations for both the reservoirs and river reaches and is able to account for surface and sediment heat exchange as well as ice dynamics for both models. The reservoir model also accounts for inflow, density, and withdrawal zone mixing, and diffusive heat exchange. Routing for the river reaches is accomplished using a modified Muskingum-Cunge approach that automatically calculates the internal timestep and sub-reach lengths to match the conditions of

  6. Warm Season Storms, Floods, and Tributary Sand Inputs below Glen Canyon Dam: Investigating Salience to Adaptive Management in the Context of a 10-Year Long Controlled Flooding Experiment in Grand Canyon National Park, AZ, USA

    NASA Astrophysics Data System (ADS)

    Jain, S.; Melis, T. S.; Topping, D. J.; Pulwarty, R. S.; Eischeid, J.

    2013-12-01

    The planning and decision processes in the Glen Canyon Dam Adaptive Management Program (GCDAMP) strive to balance numerous, often competing, objectives, such as, water supply, hydropower generation, low flow maintenance, maximizing conservation of downstream tributary sand supply, endangered native fish, and other sociocultural resources of Glen Canyon National Recreation Area and Grand Canyon National Park. In this context, use of monitored and predictive information on the warm season floods (at point-to-regional scales) has been identified as lead-information for a new 10-year long controlled flooding experiment (termed the High-Flow Experiment Protocol) intended to determine management options for rebuilding and maintaining sandbars in Grand Canyon; an adaptive strategy that can potentially facilitate improved planning and dam operations. In this work, we focus on a key concern identified by the GCDAMP, related to the timing and volume of tributary sand input from the Paria and Little Colorado Rivers (located 26 and 124 km below the dam, respectively) into the Colorado River in Grand Canyon National Park. Episodic and intraseasonal variations (with links to equatorial and sub-tropical Pacific sea surface temperature variability) in the southwest hydroclimatology are investigated to understand the magnitude, timing and spatial scales of warm season floods from this relatively small, but prolific sand producing drainage of the semi-arid Colorado Plateau. The coupled variations of the flood-driven sediment input (magnitude and timing) from these two drainages into the Colorado River are also investigated. The physical processes, including diagnosis of storms and moisture sources, are mapped alongside the planning and decision processes for the ongoing experimental flood releases from the Glen Canyon Dam which are aimed at achieving restoration and maintenance of sandbars and instream ecology. The GCDAMP represents one of the most visible and widely recognized

  7. The Variation Characteristic of Sulfides and VOSc in a Source Water Reservoir and Its Control Using a Water-Lifting Aerator.

    PubMed

    Shi, Jian-Chao; Huang, Ting-Lin; Wen, Gang; Liu, Fei; Qiu, Xiao-Peng; Wang, Bao-Shan

    2016-01-01

    Sulfides and volatile organic sulfur compounds (VOSc) in water are not only malodorous but also toxic to humans and aquatic organisms. They cause serious deterioration in the ecological environment and pollute drinking water sources. In the present study, a source water reservoir-Zhoucun Reservoir in East China-was selected as the study site. Through a combination of field monitoring and in situ release experiments of sulfides, the characteristics of seasonal variation and distribution of sulfides and VOSc in the reservoir were studied, and the cause of the sulfide pollution was explained. The results show that sulfide pollution was quite severe in August and September 2014 in the Zhoucun Reservoir, with up to 1.59 mg·L(-1) of sulfides in the lower layer water. The main source of sulfides is endogenous pollution. VOSc concentration correlates very well with that of sulfides during the summer, with a peak VOSc concentration of 44.37 μg·L(-1). An installed water-lifting aeration system was shown to directly oxygenate the lower layer water, as well as mix water from the lower and the upper layers. Finally, the principle and results of controlling sulfides and VOSc in reservoirs using water-lifting aerators are clarified. Information about sulfides and VOSc fluctuation and control gained in this study may be applicable to similar reservoirs, and useful in practical water quality improvement and pollution prevention. PMID:27092517

  8. Dynamic-reservoir lubricating device

    NASA Technical Reports Server (NTRS)

    Ficken, W. H.; Schulien, H. E.

    1968-01-01

    Dynamic-reservoir lubricating device supplies controlled amounts of lubricating oil to ball bearings during operation of the bearings. The dynamic reservoir lubricating device includes a rotating reservoir nut, a hollow cylinder filled with lubricating oil, flow restrictors and a ball bearing retainer.

  9. Loudon surfactant flood pilot--overview and update

    SciTech Connect

    Bragg, J.R.; Canning, J.W.; Gale, W.W.

    1983-03-01

    A successful surfactant (microemulsion) flood pilot test in a watered-out portion of the Weiler sand, Loudon Field, Illinois (USA) was completed in October, 1981. The microemulsion system tested was designed to be effective in the presence of highsalinity formation water containing 104,000 ppm (mg/1) total dissolved solids (TDS) without use of a preflush. The test was conducted in a single, 0.68acre (2752 m/sup 2/) 5-spot operated in a manner that approximated a confined pattern. The test was highly successful, recovering 60% of the oil remaining after waterflood. Cores from a post-flood well drilled within the pattern have confirmed the low final oil saturations and low surfactant retention achieved in the flood. Although oil recovery was excellent, loss of mobility control in the polymer drive bank and premature breakthrough of lower-salinity drive water were observed part-way through the test. Laboratory and field studies conducted since flood termination have confirmed that loss was caused by bacterial degradation of the xanthan biopolymer used. Several biocides were tested in the laboratory and in a field injection experiment to determine their effectiveness against the bacteria contaminating the pilot. Formaldehyde was shown to kill bacteria within the formation, have negligible absorption on reservoir rock, and permit propagation of undegraded polymer. Based on these test results, formaldehyde should protect xanthan biopolymer from bacterial degradation in future microemulsion floods at Loudon.

  10. Pollution prevention opportunity assessment at the US Army Corps of Engineers John H. Kerr Dam and Reservoir, Boydton, Virginia. Report for July-September 1994

    SciTech Connect

    Buschow, R.; Bowman, D.; Smith, J.

    1995-08-01

    The report describes the results of pollution prevention opportunity assessments conducted at a representative U.S. Army Corps of Engineers civil works facilities including a flood control reservoir and associated public use areas. Recommended methods for reducing pollution resulting primarily from the operation of these facilities are addressed.

  11. Modeling of reservoir operation in UNH global hydrological model

    NASA Astrophysics Data System (ADS)

    Shiklomanov, Alexander; Prusevich, Alexander; Frolking, Steve; Glidden, Stanley; Lammers, Richard; Wisser, Dominik

    2015-04-01

    Climate is changing and river flow is an integrated characteristic reflecting numerous environmental processes and their changes aggregated over large areas. Anthropogenic impacts on the river flow, however, can significantly exceed the changes associated with climate variability. Besides of irrigation, reservoirs and dams are one of major anthropogenic factor affecting streamflow. They distort hydrological regime of many rivers by trapping of freshwater runoff, modifying timing of river discharge and increasing the evaporation rate. Thus, reservoirs is an integral part of the global hydrological system and their impacts on rivers have to be taken into account for better quantification and understanding of hydrological changes. We developed a new technique, which was incorporated into WBM-TrANS model (Water Balance Model-Transport from Anthropogenic and Natural Systems) to simulate river routing through large reservoirs and natural lakes based on information available from freely accessible databases such as GRanD (the Global Reservoir and Dam database) or NID (National Inventory of Dams for US). Different formulations were applied for unregulated spillway dams and lakes, and for 4 types of regulated reservoirs, which were subdivided based on main purpose including generic (multipurpose), hydropower generation, irrigation and water supply, and flood control. We also incorporated rules for reservoir fill up and draining at the times of construction and decommission based on available data. The model were tested for many reservoirs of different size and types located in various climatic conditions using several gridded meteorological data sets as model input and observed daily and monthly discharge data from GRDC (Global Runoff Data Center), USGS Water Data (US Geological Survey), and UNH archives. The best results with Nash-Sutcliffe model efficiency coefficient in the range of 0.5-0.9 were obtained for temperate zone of Northern Hemisphere where most of large

  12. An R package for the design, analysis and operation of reservoir systems

    NASA Astrophysics Data System (ADS)

    Turner, Sean; Ng, Jia Yi; Galelli, Stefano

    2016-04-01

    We present a new R package - named "reservoir" - which has been designed for rapid and easy routing of runoff through storage. The package comprises well-established tools for capacity design (e.g., the sequent peak algorithm), performance analysis (storage-yield-reliability and reliability-resilience-vulnerability analysis) and release policy optimization (Stochastic Dynamic Programming). Operating rules can be optimized for water supply, flood control and amenity objectives, as well as for maximum hydropower production. Storage-depth-area relationships are in-built, allowing users to incorporate evaporation from the reservoir surface. We demonstrate the capabilities of the software for global studies using thousands of reservoirs from the Global Reservoir and Dam (GRanD) database fed by historical monthly inflow time series from a 0.5 degree gridded global runoff dataset. The package is freely available through the Comprehensive R Archive Network (CRAN).

  13. Structural control of geothermal reservoirs in extensional tectonic settings: An example from the Upper Rhine Graben

    NASA Astrophysics Data System (ADS)

    Meixner, Jörg; Schill, Eva; Grimmer, Jens C.; Gaucher, Emmanuel; Kohl, Thomas; Klingler, Philip

    2016-01-01

    In extensional tectonic settings major structural elements such as graben boundary faults are typically oriented subparallel to the maximum horizontal stress component SHmax. They are often structurally accompanied by transfer zones that trend subparallel to the extension direction. In the Upper Rhine Graben, such transfer faults are typically characterized by strike-slip or oblique-slip kinematics. A major re-orientation of the regional stress field by up to 90° of the Upper Rhine Graben in the Early Miocene led to the present-day normal and strike-slip faulting regimes in the North and South of the Upper Rhine Graben, respectively, and a transition zone in-between. Consequently, conditions for fault frictional failure changed significantly. Moreover, it has been observed during tracer and stimulation experiments that such transfer faults may be of major importance for the hydraulic field of geothermal reservoirs under the present stress condition, especially, when located between production and injection well. In this context we have investigated slip and dilation tendencies (TS and TD) of major structural elements at reservoir scale for two representative geothermal sites, Bruchsal (Germany) and Riehen (Switzerland), located close to the Eastern Main Boundary Fault of the Upper Rhine Graben. We have evaluated the quality and uncertainty range of both tendencies with respect to potential variation in SHmax orientation. Despite significant differences in orientation of the structures and the stress regimes, the resulting variation of TS and TD reveal major similarities concerning the reactivation potential of both, the graben-parallel structures and the transfer faults. The conditions of criticality for tensile failure and non-criticality for shear failure suggest that transfer faults are most likely naturally permeable structures with low stimulation potential. This is in agreement with the absence of both immediate tracer recovery and seismicity in the studied

  14. Diagenetic control of reservoir quality of Araba and Naqua diagenetic quartzarenites (Cambrian), Gebel Araba-Qabeliat, Southwest Sinai, Egypt

    SciTech Connect

    Abdel-Wahab, A. ); Mcbride, E.F. )

    1991-03-01

    Sandstones of the marine Lower Cambrian Araba Formation and the overlying fluvial Upper Cambrian( ) Naqus Formation in Gebel Araba-Qabeliat, southwest Sinai (the eastern side of the Gulf of Suez) were studied to evaluate the major factors controlling potential hydrocarbon reservoir quality. The formations have a composite thickness of 873 m and overlie Precambrian granite and metamorphic rocks and underlie Cretaceous marine strata. The framework composition of both sandstones is almost entirely quartz with trace amounts of muscovite, K-feldspar, and heavy minerals. Up to 21.5% oversize pores, some filled with younger cements, attest to extensive dissolution loss of detrital grains, chiefly feldspar. Because the final mineralogical maturation of these quartzarenites was through diagenesis, they are diagenetic quartzarenites. Following deposition, the introduction of thin coatings of infiltered clay was followed by the precipitation of 6.3% unhomogeneously distributed quartz cement. Some outcrop samples contain pore-occluding gypsum cement or mixtures of gypsum and halite cement. Sr{sup 87}/Sr{sup 86} ratios of seven samples of gypsum cement have values (0.7077 to 0.7083) that are equal to Miocene and slightly younger seawater. These Cambrian sandstones have excellent reservoir potential (mean thin section porosity = 25.7%) because they contained few ductile grains to enhance compaction, and they developed significant amounts of secondary pores by both dissolution of calcite cement and unstable detrital grains. Kaolinite and dickite are potential problems for hydrocarbon production in some beds.

  15. Abiotic control of underwater light in a drinking water reservoir: Photon budget analysis and implications for water quality monitoring

    NASA Astrophysics Data System (ADS)

    Watanabe, Shohei; Laurion, Isabelle; Markager, Stiig; Vincent, Warwick F.

    2015-08-01

    In optically complex inland waters, the underwater attenuation of photosynthetically active radiation (PAR) is controlled by a variable combination of absorption and scattering components of the lake or river water. Here we applied a photon budget approach to identify the main optical components affecting PAR attenuation in Lake St. Charles, a drinking water reservoir for Québec City, Canada. This analysis showed the dominant role of colored dissolved organic matter (CDOM) absorption (average of 44% of total absorption during the sampling period), but with large changes over depth in the absolute and relative contribution of the individual absorption components (water, nonalgal particulates, phytoplankton and CDOM) to PAR attenuation. This pronounced vertical variation occurred because of the large spectral changes in the light field with depth, and it strongly affected the average in situ diffuse absorption coefficients in the water column. For example, the diffuse absorption coefficient for pure-water in the ambient light field was 10-fold higher than the value previously measured in the blue open ocean and erroneously applied to lakes and coastal waters. Photon absorption budget calculations for a range of limnological conditions confirmed that phytoplankton had little direct influence on underwater light, even at chlorophyll a values above those observed during harmful algal blooms in the lake. These results imply that traditional measures of water quality such as Secchi depth and radiometric transparency do not provide a meaningful estimate of the biological state of the water column in CDOM-colored lakes and reservoirs.

  16. 33 CFR 211.6 - Rights which may be granted by the Secretary of the Army in river and harbor and flood control...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Rights which may be granted by the Secretary of the Army in river and harbor and flood control property. 211.6 Section 211.6 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE REAL ESTATE ACTIVITIES OF THE CORPS OF ENGINEERS...

  17. Framework for the comparison of the performance of restoration of floodplain retention vs. technical retention basins for the reduction of flood risk

    NASA Astrophysics Data System (ADS)

    Szolgay, Ján.; Danáčová, Michaela; Pástorová, Jana

    2010-05-01

    conditions. The applicability of this model parametrisation was verified on floods not used for the travel-time vs. peak-discharge analysis. Further a simple conceptual model of the flood detention reservoirs planned to be constructed on the Morava River was also proposed. The model assumes, that the forecast lead time during floods is sufficient to control the operation of these. Since the changes detected in the travel-time of floods peaks were included in the parameterisation of the multilinear model, the changes in design floods could have been assessed by frequency analysis of flood peaks gained by the simulation of the attenuation of a series of flood waves. Eighty flood waves of annual maximum floods from the period 1923-2002 were routed for pre-river training conditions, which represent a total restoration of lost flood plains, present river bed conditions and through the planned reservoirs. The past, present and expected flood regime of the lower Morava River was statistically analyzed, design floods were compared and the effectiveness of the proposed measures discussed.

  18. Living on the Edge of Stagnant Water: An Assessment of Environmental Impacts of Construction-Phase Drainage Congestion Along Dhaka City Flood