U.S. Army Corps Of Engineers Research Articles

Analysis of the Impacts of Dikes on Flood Stages in the Middle Mississippi River

AbstractThe US Army Corps of Engineers has constructed numerous river engineering structures in and along the Middle Mississippi River. River training and bank stabilization measures include pile dikes, stone dikes, bendway weirs, chevrons, and revetments. Concerns have long been voiced about the effects of these structures on flood stages. Recent debate concerning the scientific basis for these concerns has been invigorated by specific gauge analysis that appears to show a rising trend in flood stages over the past 150 years. This paper attempts to advance the debate by providing an objective review of the specific gauge analysis technique that explains how the method should be performed and the results interpreted; identifies strengths and limitations; examines the uncertainties associated with application to the Middle Mississippi River given the available data; and reassesses the conclusions that can and cannot reasonably be drawn regarding the impacts of dikes and levees on flood stages, based on spe...

Assessing sediment toxicity: Past, present, and future

Assessing sediment toxicity: Past, present, and future

Research Articles: Preparation Times for Final Environmental Impact Statements Made Available from 2007 through 2010

Annual average environmental impact statement (EIS)-preparation times for all EIS-preparing entities combined were highly variable after 2006 and peaked in 2008 at 1,522 days (4.2 years). The annual average EIS-preparation time for all entities increased from 2007 through 2010 at an average rate of +19.9 days/year. The trend of increasing preparation times measured from 1998 was maintained through 2010, but the average rate of increase, +26.7 days/year, was slightly less than that measured from 1998 through 2006. Annual average EIS-preparation times for the three most prolific EIS producers—US Forest Service, Federal Highway Administration, and US Army Corps of Engineers—generally decreased after 2006. In contrast, the annual average EIS-preparation time for all other EIS-preparing entities combined increased after 2006 at an average rate of +76.2 days/year, and these entities produced 55% of all final EISs after 2006. Preparation times for EISs on general resource management plans required of the US Fore...

The Long Road to Recovery: Environmental Health Impacts of Hurricane Sandy

Building contractor John Pierciey stands in the gutted interior of a 1950s-era home in Manasquan, New Jersey. Wallboard, two layers of wood flooring, a layer of felt—all of it had to be ripped out to rid the house of mold caused by Hurricane Sandy’s storm surge. “This is the sixth house I’ve gutted in a week,” Pierciey says. “Every one is different. You don’t know what you’re going to find until you take them apart.” Residents and volunteers keep warm by a fire barrel in the New Dorp Beach neighborhood of Staten Island, 5 November 2012. Power outages persisted through a cold snap that put temperatures in the single digits. So it is with the environmental health impacts of Hurricane Sandy. Every layer of society, every type of building, has felt the impact of the storm, which struck the U.S. East Coast on 29 October 2012. Incidences of death and illness, though small in number compared with some storms, have come in many forms, the effects still unfolding as time goes by.

Application of the HEC-HMS model for runoff simulation in a tropical catchment

Hydrologic simulation employing computer models has advanced rapidly and computerized models have become essential tools for understanding human influences on river flows and designing ecologically sustainable water management approaches. The HEC-HMS is a reliable model developed by the US Army Corps of Engineers that could be used for many hydrological simulations. This model is not calibrated and validated for Sri Lankan watersheds and need reliable data inputs to check the suitability of the model for the study location and purpose. Therefore, this study employed three different approaches to calibrate and validate the HEC-HMS 3.4 model to Attanagalu Oya (River) catchment and generate long term flow data for the Oya and the tributaries.Twenty year daily rainfall data from five rain gauging stations scattered within the Attanagalu Oya catchment and monthly evaporation data for the same years for the agro meteorological station Henarathgoda together with daily flow data at Dunamale from 2005 to 2010 were used in the study. GIS layers that were needed as input data for the flow simulation were prepared using Arc GIS 9.2 and used in the HEC-HMS 3.4 calibration of the Dunamale sub catchment using daily flow data from 2005 to 2007. The model was calibrated adjusting three different methods. The model parameters were changed and the model calibration was performed separately for the three selected methods, the Soil Conservation Service Curve Number loss method, the deficit constant loss method (the Snyder unit hydrograph method and the Clark unit hydrograph method) in order to determine the most suitable simulation method to the study catchment. The calibrated model was validated with a new set of rainfall and flow data (2008–2010). The flows simulated from each methods were tested statistically employing the coefficient of performance, the relative error and the residual method. The Snyder unit hydrograph method simulates flows more reliably than the Clark unit hydrograph method. As the loss method, the SCS Curve Number method does not perform well.

Critical Risk Path Method

Existing approaches to risk management in construction procurement primarily dwell on strategies designed for commonly identifiable risk factors in typical project environments. Commonly identifiable risk factors would include too early or late material delivery - a condition typically ameliorated by implementing a Just In Time (JIT) plan; inferior construction materials typically mitigated by employing trusted vendors; or ineffective contractors primarily avoided by the use of experienced contractors. The purpose of this paper is to present a coherent model for procurement risk management for construction and infrastructure development projects within the context of dynamic project environments - complex, or chaotic. For the purpose of this study, a critical risk path activity is one in which a delay of activity completion not only leads to project delay, but does so in a manner that may be fatal to project or at best, far greater than the actual delay. The study incorporates observations and theory with practical application for improving initiatives by emergency infrastructure development response organizations such as FEMA (Federal Emergency Management Agency) and USACE (US Army Corps of Engineers) in the United States, the NEMA (National Emergency Management Agency) in Nigeria, or ANDMA (Afghanistan National Disaster Management Authority) etc. This study presents risk response plans aimed at improving the potential occurrence of positive risk aspects while reducing, or eliminating the same for negative risk occurrences. This study explored material, equipment, and skilled labor procurement strategies related to project risk management from the perspectives of scheduling, cost, and quality - three factors often referred to as the triple project constraints. It identified gaps within specific national and multinational organizations’ approaches, and provided detailed recommendations for process improvements from the procurement management perspective to ensure the potential for successful project outcomes in unstable project conditions.

동수압 모형을 이용한 고립파의 처오름 해석

본 연구에서는 동수압을 고려할 수 있는 수치모형을 제시하였다. 제시한 모형은 유속성분, 자유수면변위와 동수압을 해석하기 위하여, 크게 2단계로 나누어 수치모의를 수행한다. 첫 번째 단계에서는 이전단계에서 구한 동수압과 자유수면변위를 이용하여 운동량방정식을 해석하고, 두 번째 단계에서는 최종적인 유속장과 자유수변변위를 계산한다. 개발된 수치모형을 이용하여 원형섬 주변에서 고립파의 진행과 처오름 현상에 대해 수치모의를 실시하였고, 수치모의 결과는 미국 육군 공병단 해안공학연구소(CERC)의 수리실험 결과와 비교하였다. 수치모의 결과는 실험결과와 잘 일치하였다. A three-dimensional hydrodynamic pressure model is newly developed in this study. The velocity components, the free surface elevations and the hydrodynamic pressures are calculated with two steps in the model. In the first step, the momentum equations are solved using the previously calculated hydrodynamic pressure and free surface elevation within a staggered grid system. In the second step, the velocity fields and free surface elevations are obtained. The developed model is applied to propagation and sub-sequent run-up process of nearshore solitary waves attacking a circular island. The obtained run-up heights are compared with laboratory measurements done by the Coastal Engineering Research Center(CERC), US Army Corps of Engineers. A very reasonable agreement is observed.

Statistical measures of extremal dependence illustrated using measured sea surface elevations from a neighbourhood of coastal locations

The extremal dependence of stationary time-series at pairs of locations can be summarised using one or more of a number of statistics. We illustrate the application of the coefficient of tail dependence, the χ and χ¯ statistics, and the conditional extremes model of Heffernan–Tawn to estimate the extremal dependence in time-series of 3-h maxima of sea surface elevation across a spatial array of measurement gauges at the US Army Corps of Engineers' Field Research Facility on the Atlantic coast of North Carolina. Although the original data are non-stationary, we induce stationarity on a site-by-site basis using a non-parametric model to remove the mean trend. Subsequently, we find that pairs of locations are generally asymptotically dependent. Parameter estimates for the Heffernan–Tawn model, although uncertain, suggest that characteristics of conditional extremes vary systematically with distance from the conditioning site.

Composite Risk Assessment for the Sacramento–San Joaquin Delta Levee System

AbstractThe objectives of this project were to analyze available Sacramento–San Joaquin Delta, California, levee risk information in a Composite Risk Management matrix and examine the results for management decision support. U.S. Army Corps of Engineers (USACE) guidance documents define risk as the “probability and severity of loss linked to hazards” and prescribe a composite risk assessment method. The Delta Risk Management Strategy performed for a group of state and federal partners provided analyses of the relative probability of hazards and severity of risks in the Delta and provide the information needed for a risk analysis compliant with USACE requirements. Composite Risk assessment provides rank-ordered lists of the highest risk zones–those with the greatest probability of failure combined with the most severe consequences–for several hundred protected areas in the Delta. Although uncertainties in the absolute magnitude of the results make them most useful for comparisons, the actual values of the ...

Integrating social vulnerability into federal flood risk management planning

AbstractWhile flood risk management planning in the United States has focused on flood control structures designed to protect the economic value of property, it has consistently undervalued other social impacts associated with flooding. The US Army Corps of Engineers (USACE) recently initiated research aimed at understanding how to incorporate social characteristics into the measures currently utilised in flood control project evaluation and consideration. This paper proposes a methodology for incorporating a known measure of social vulnerability, the Social Vulnerability Index (SoVI), into USACE civil works planning. Using the USACE South Atlantic Division as the study area, this paper evaluates eight different variations of the social vulnerability metric and their potential deployment in USACE projects. Each formulation is compared with the original‐computed SoVI as a means to test its spatial and statistical sensitivity, including an assessment of each variant's robustness, reducibility, scalability, and transferability. Results indicate that while it is possible to create simplified, yet robust, versions of SoVI for individual places, such ‘lite’ metrics tend to fall short in areas of scalability and transferability in relation to the original SoVI formulation.

Restoration of 2011 flood-damaged Birds Point-New Madrid Floodway

D uring the spring 2011 flooding along the Mississippi River, the strong current and sweep of water through the Birds Point, Missouri, levee breach in May of 2011 created a hundred hectares (hundreds of acres) of deep gullies; scoured hundreds of hectares (hundreds of acres) of land; eroded tons of soil; filled ditches with sediment which blocked drainage; created sand deltas; and damaged irrigation equipment, farm buildings, and homes. Reclamation and restoration of these agricultural lands following the US Army Corps of Engineers' (USACE) opening of the New Madrid Floodway to relieve flood pressure on the levee system from the Mississippi River (Camillo 2012; Olson and Morton 2012a, 2012b) has been time consuming and costly to individual landowners and public tax dollars. While levees were rebuilt, ditches cleared of sediment, and many lands in the floodway restored by November of 2012, soil productivity and growing conditions continue to challenge the farmers of this historically highly productive region. The USACE decision to blow up Birds Point levee along the Lower Mississippi River and flood agricultural lands in the New Madrid Floodway (Missouri) (figure 1) was difficult, with substantive legal challenges as well as social and political trade-offs between human life and property…

HAWAII HURRICANE WAVE AND SURGE MODELING AND FAST FORECASTING

The US Army Corps of Engineers' Surge and Wave Island Modeling Studies developed a fast forecasting system for hurricane waves and inundation in Hawaii. The system is based on coupled high-resolution, high-fidelity simulations of waves and surge applying the SWAN and ADCIRC numerical models on a 2D finite-element grid. Additionally, wave runup is simulated on high-resolution cross-shore transects using the Boussinesq-equation model BOUSS-1D. Approximately 1500 storms were simulated to cover the range of hurricane parameters of landfall location, track angle at landfall, central pressure, forward speed, and radius of maximum winds expected to impact Hawaii. To create a forecast system that is fast and robust, a moving least-squares response surface surrogate model was developed based on the high-fidelity model results. The surrogate model is approximately seven orders of magnitude faster than the high-fidelity simulations. The efficiency of the surrogate model allows both deterministic and probabilistic simulations in seconds to minutes on a personal computer.

Regional climate gradients in precipitation and temperature in response to climate teleconnections in the Greater Everglades ecosystem of South Florida

Precipitation and temperature in Florida responds to climate teleconnections from both the Pacific and Atlantic regions. In this region south of Lake Okeechobee, encompassing NWS Climate Divisions 5, 6, and 7, modern movement of surface waters are managed by the South Florida Water Management District and the US Army Corps of Engineers for flood control, water supply, and Everglades restoration within the constraints of the climatic variability of precipitation and evaporation. Despite relatively narrow, low-relief, but multi-purposed land separating the Atlantic Ocean from the Gulf of Mexico, South Florida has patterns of precipitation and temperature that vary substantially on spatial scales of 101–102 km. Here we explore statistically significant linkages to precipitation and temperature that vary seasonally and over small spatial scales with El Nino-Southern Oscillation (ENSO), the Atlantic Multidecadal Oscillation (AMO), and the Pacific Decadal Oscillation (PDO). Over the period from 1952 to 2005, ENSO teleconnections exhibited the strongest influence on seasonal precipitation. The Multivariate ENSO Index was positively correlated with winter (dry season) precipitation and explained up to 34 % of dry season precipitation variability along the southwest Florida coast. The AMO was the most influential of these teleconnections during the summer (wet season), with significant positive correlations to South Florida precipitation. These relationships with modern climate parameters have implications for paleoclimatological and paleoecological reconstructions, and future climate predictions from the Greater Everglades system.

Progress and Pollution: Port Cities Prepare for the Panama Canal Expansion

Early in the planning of the Panama Canal, Navy Commander Thomas Oliver Selfridge, Jr., wrote that “advantageous as an interoceanic canal would be to the commercial welfare of the whole world, it is doubly so for the necessities of American interests.”1 And indeed, since the Canal opened in 1914, it has been the main conduit for ocean-going ships carrying trade worldwide. Today the United States ranks number one in tons of cargo passing through the Canal (China ranks number two).2 In 2011 nearly 13,000 ocean-going cargo ships made the passage.3 Starting in the late 1950s (and expanding rapidly thereafter), internationally traded goods started being shipped in large metal containers, making it possible to load and unload cargo by machine instead of by hand and spurring the manufacture of larger ships.4 “Panamax” ships were designed to be just small enough to squeeze through the locks of the Canal.5 Today, even larger ships—called “post-Panamax” because they are too large to fit through the Canal6—make up 16% of the world’s container fleet but account for nearly half the fleet’s cargo capacity.7 To allow these larger ships to transit the Canal and increase its ability to handle higher volumes of ships, Panama is building a third set of locks, with construction expected to be finished in 2015.7 The Panama Canal expansion has sparked the competitive imagination of East Coast and Gulf Coast (EC/GC) port authorities, who hope to capture some of the 70% of U.S. imports currently controlled by West Coast (WC) ports.8 Ports typically make their revenues through leases with shipping lines, wharfage fees, and tariffs. So the more containers a port handles, the more money it can make. Experts at the U.S. Army Corps of Engineers (USACE) call the Panama Canal expansion a likely “game changer” for U.S. trade, potentially redistributing the market share of each coast’s ports, as well as opening up new import and export markets for agricultural and other products along inland waterways.7 Some have estimated that container volumes at EC/GC ports could more than double from 2012 to 2029.7 But with this growth come questions about what major initiatives to expand cargo capacity could mean for public health in these port cities.

Assessing the collaborative capacity of the U.S. Army Corps of Engineers: Relevant literature, a practical assessment tool, and reflections on third‐party roles

AbstractThis article focuses on the third‐party roles in a 2008 to 2010 assessment of the collaborative capacity of the U.S. Army Corps of Engineers (USACE). Within USACE, the effort was led by the Institute for Water Resources' Conflict Resolution & Public Participation Center. Third‐party assistance was provided by a professional environmental facilitator under contract to USACE. Data were obtained through an online assessment tool (n = 230) and nine workshops. A national stakeholder Review Group and a cadre of internal liaisons to field personnel provided input at strategic milestones. The resulting collaborative capacity development recommendations are now being implemented.

The USACE and Post-Katrina New Orleans

In this article, we present demolition data to explore the way the patterns of demolition carried out by the U.S. Army Corps of Engineers (USACE) were constituted as a social problem by residents of the Lower Ninth Ward and members of the broader New Orleans community. Through a study of newspaper stories and press interviews about the implementation process, we find evidence of a gap that exists between the interpretation of the demolitions by residents of the Lower Ninth, and the need to carry out disaster clean-up among city officials and the USACE. This gap, we suggest, is constitutive of an implementation problem that may best be dealt with in policymaking processes focused on planning for disasters.

Data Enhancement and Standardization Using AIS and GIS: A Public and Private Effort

Over time, a number of federal agencies have been involved in collecting and maintaining marine navigation data. Similarly, private industry involved in maritime commerce also collects and maintains its own proprietary navigation-related database. In several cases, data collected by federal agencies and industry is incomplete, and over time these data sets become inconsistent and often unreliable. In addition, operational inefficiencies arise when private industry data are shared between different owners, operators, and service providers. Most federal agencies also face similar issues of incompatibility and incompleteness of marine navigation data. To address these problems, the U.S. Army Corps of Engineers (USACE) has initiated an effort to standardize and enhance navigation and maritime data across selected government agencies through the Federal Initiative for Navigation Data Enhancement (FINDE). On the private industry side, the Corps has been involved in the Federal-Industry Logistics Standardization (FILS) initiative. In parallel, the Corps has initiated an effort to enhance the data and make them even more accurate by using the Automatic Identification System (AIS). This paper documents these efforts and demonstrates how GIS technology has been incorporated to enhance data acquisition to detect vessel stops, particularly at docks and terminals.

An analytical approach for levee underseepage analysis

Summary Levee underseepage analyses are commonly performed to assess the risk of erosion and piping of levee foundation soils. They are also commonly used to estimate the quantity of seepage that is expected to pass beneath a levee over time, and to assess the risk of excessively high pore pressures at various points in the foundation. A variety of approaches have historically been utilized to perform steady-state underseepage analyses in levees, including flow-nets, closed-form analytical solutions, and numerical techniques such as finite difference or finite element analyses. This paper provides a derivation of a series of closed-form “blanket theory” analytical equations that can be used to perform a levee underseepage analysis. This derivation starts from a generic confined flow analytical solution, of the type that is common in groundwater flow analyses. The solution is then extended to simulate semiconfined flow beneath a levee in a shallow aquifer. Equations are presented for calculating total head and seepage quantity values for different model boundary conditions. A typical example problem is used to compare the analytical equations that are derived with the analytical equations that are presented in the US Army Corps of Engineers (USACE) levee design manual. The results provide validation for both the equations that are presented and the conventional USACE analytical design approach. Using the results from the example problem, general guidance and suggestions are provided for designers that use closed-form analytical approaches for modeling levee underseepage.

Analytical Calibration Approach to Develop a Seepage Model for the London Avenue Canal Load Test

The U.S. Army Corps of Engineers (USACE) conducted a load test along a portion of the London Avenue Canal as a part of an extensive study following the events of Hurricane Katrina to investigate the performance of I-walls and levees. A 45.7 m (150 ft) long section of the I-wall was hydraulically loaded, and pore pressures and displacements were measured in the vicinity of the I-wall through an extensive instrumentation system. The acquired data were assessed to develop a seepage model that would be applicable to the London Avenue Canal and areas where the soil conditions are similar. Two-dimensional and three-dimensional finite-element seepage analyses were conducted, a parametric study was performed, and a statistical calibration technique was developed to better estimate the actual field conditions in the numerical modeling. Based on this analysis, soil properties and finite-element boundary conditions are recommended for future analyses of the London Avenue Canal and other canals having similar subsurface conditions.

제내 비탈끝 배수공을 이용한 제방의 침투조절에 관한 연구

하천 제방은 홍수 시 유수를 원활하게 소통시키고 제내지를 보호하기 위해 하천을 따라 축조한 시설이다. 하지만 이러한 제방도 침투로 인해 제내지측 사면에 포화표면이 지속적으로 발생하게 되면, 제방은 파괴될 수 있다. 제체 침투에 의해 발생되는 침윤선은 적절한 배수 체계를 이용하여 강하될 수 있다. 본 연구의 목적은 제내지 비탈 끝에 설치되는 배수공을 통한 침투조절의 효과를 제시하고, 각기 다른 형상을 하고 있는 미국의 공병단과 일본의 국토개발기술연구센터에서 제시한 배수공의 효과를 비교, 검토하는데 있다. 이를 위해 배수공의 포함 여부에 따른 제방 침투에 관한 모형실험을 수행하였다. 축조된 제방 모형의 규격은 둑마루폭 0.5m, 하부폭 2.6m, 사면경사 1 : 2, 제방 높이 0.55m이고, 제외지측 수위는 0.5m이다. 미 공병단의 배수공은 삼각형이고 일본의 국토개발기술연구센터의 배수공은 사각형이며, 각각의 배수공 폭은 0.4m로 설치하였다. 배수공을 포함하지 않은 제방 모형에서는 침투에 의해 제내지측 사면에 포화표면이 발생하였으나, 미 공병단과 일본의 국토개발기술연구센터에서 제시한 배수공을 포함한 제방에서는 모두 포화표면이 발생하지 않았다. 이러한 모형실험의 결과는 SEEP/W를 통한 수치모의 모형의 보정과 검증에 활용되었다. 그리고 배수공의 폭을 5 cm씩 줄여가며 수치모의를 수행해 본 결과, 일본의 국토개발기술연구센터식 배수공이 미국의 공병단식 배수공에 비해 다소 안정한 것으로 분석되었다. 또한, 일본의 국토개발기술연구센터식 배수공은 시공이 쉬운 장점이 있다. 본 연구의 결과는 향후 배수공을 이용한 제방의 침투조절 계획에 활용될 수 있을 것으로 전망된다. The levee is the facility which is constructed along with river for the protection of landside and for passage of water when there is a flood. When the seepage is exposed to the atmosphere on the landside surface of levee, it may eventually lead to levee failure. The seepage water may be removed from the landside surface by a properly designed drainage system. The purpose of the study is to show seepage control effect of a pervious toe drain, and to compare two drainage methods of a pervious toe drain. One is the pervious toe drain suggested by U.S. Army Corps of Engineers (USACE) and the other is that suggested by Japan Institute of Construction Engineering (JICE). The levee model constructed has the following dimension: the base width is 2.6 m; the crest width is 0.4 m; the side slope 1 : 2. The water depth in the riverside is 0.5 m. The shape of the toe drain by USACE is triangular. The shape of the toe drain by JICE is rectangular. They were installed with the base length of 0.4 m. The levee model without the toe drain showed saturation surface on the land side in the experiment but not with the toe drain. The experiment results was applied to a numerical analysis model using SEEP/W to calibrate and verify. The numerical analysis results for 35 cm and 30 cm drain width showed that the drain by JICE is a little bit safer than the drain by USACE. It is also easier to construct the toe drain by JICE. The results in the study would be applied to plan the seepage control for a levee with pervious toe drain.