The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.

The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.

Understanding the internal organization of the Lower Pleistocene 8 Sand reservoir in the Green Canyon 18 field, Gulf of Mexico, helps to increase knowledge of the geology and the petrophysical properties, and hence contribute to production management in the area. Interpretation of log data from 29 wells, core and production data served to detail as much as possible a geological model destined for a future reservoir simulation. Core data showed that the main facies resulting from fine-grained turbidity currents is composed of alternating sand and shale layers, whose extension is assumed to be large. They correspond to levee and overbank deposits that are usually associated to channel systems. The high porosity values, coming from unconsolidated sediment, were associated to high horizontal permeability but generally low kv/kh ratio. The location of channel deposits was not obvious but thickness maps suggested that two main systems, with a northwest-southeast direction, contributed to the 8 Sand formation deposition. These two systems were not active at the same time and one of them was probably eroded by overlying formations. Spatial relationships between them remained unclear. Shingled stacking of the channel deposits resulted from lateral migration of narrow, meandering leveed channels in the mid part of the turbidite system. Then salt tectonics tilted turbidite deposits and led to the actual structure of the reservoir. The sedimentary analysis allowed the discrimination of three facies A, B and E, with given porosity and permeability values, that corresponded to channel, levee and overbank deposits. They were used to populate the reservoir model. Well correlation helped figure out the extension of these facies.

The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.

This study combined flood-frequency analysis, 1-D (one-dimensional) hydraulic modeling using HEC-RAS, and flood-loss modeling using FEMA's Hazus-MH (Hazards U.S. Multi-Hazard) in order to: 1) quantify how different flood-frequency methodologies affect flood-risk assessments, and 2) quantify the impacts of different floodplain-management scenarios along the Middle Mississippi River (MMR). The nine scenarios tested here included various combinations of flood-frequency methodology, buyouts, and levee configurations. The levee configurations analyzed included: 1) current levee configuration, 2) no levees, 3) a 1500 m levee setback, 4) a 1000 m levee setback, and 5) a customized levee setback designed to maximize protection around existing infrastructure. Two study reaches were chosen: (1) an Urban Study Reach within St. Clair and northern Monroe Counties, IL, with levees designed to withstand the 500-year flood and (2) an Agricultural Study Reach within Union and Jackson Counties, IL, with <100-year levees. A flood-frequency analysis was completed for the St. Louis, MO gauging station, and detailed building inventories were used to estimate flood losses on a structure-by-structure basis (Hazus-MH UDF analysis) for an array of floods ranging from the 2- to the 500-year events. These flood-loss estimates were combined with a stochastic levee-failure model. Finally, estimated flood damages from Hazus-MH were integrated across the full range of flood recurrences in order to calculate expected annual damage (EAD). This study's flood-frequency analysis and corresponding flood-loss assessment demonstrate how differences in flood-frequency methodology can significantly impact flood-risk assessments. EAD based on the UMRSFFS (Upper Mississippi River System Flow Frequency Study) flood frequencies was 68% ($45.4 million) lower than EAD based on this study's flood frequencies. This decrease in EAD demonstrates that the UMRSFFS flood frequencies and corresponding stages may significantly underestimate flood risk within the Urban Study Reach. The 100-year discharge in the UMRSFFS appears to be underestimated by an estimated 17% (187,000 cfs), resulting in a 10% (1.6 m) underestimation of the 100-year flood level. Given the magnitude of the EAD, discharge, and stage differences documented here, a reanalysis of the MMR flood frequencies, flood profiles, and flood maps should be considered. The hydraulic modeling completed here showed that levee setbacks and levee removal successfully reduce stages for all recurrence intervals. For the 100-year flood, average reductions ranged from 0.20 m for a 1000 m levee setback to 1.61 m with levees removed. In general, stage reductions increased with increasing discharge and with increasing setback distance. The flood-level reductions are attributed to increased floodwater storage and conveyance across the reconnected floodplain. Compared to the current conditions, the levee setback and levee removal scenarios tested here reduced flood losses for large, infrequent flooding events but increased flood losses for smaller, more frequent flood events. When combined with buyouts of unprotected structures, levee setbacks reduced flood losses for all recurrence intervals. The 1000 m and 1500 m levee setbacks required buyouts in order to reduce EAD; however, a levee setback carefully planned around existing high-value structures reduced EAD with or without buyouts. The planned levee setback configuration combined with buyouts resulted in the largest decreases in EAD: a $16.8 million (55%) decrease in the Urban Study Reach and an $8.3 million (93%) decrease in the Agricultural Study Reach. Overall, this project showed that levee setbacks in combination with buyouts are an economically viable approach for flood-risk reduction along the study reaches and likely elsewhere where levees are widely employed for flood control. Designing a levee setback around existing high-value infrastructure can maximize the benefit of the setback while simultaneously minimizing the costs. Potentially, this type of planned levee configuration could be used as a template for the replacement of aging or failing levee systems.

This study utilized a new database of levee failures along 685 km of the Middle and Lower Mississippi River from St. Louis, MO to Memphis, TN during the past 120 years. The goals of this investigation were to: 1) identify the relative importance of geologic and geomorphic factors that have led to levee failures through the past century along the Mississippi River and 2) measure levee crest elevations to determine if they have increased or decreased between 1998 and 2007 and if they are built to the proper design grade elevation. Logistic regression analysis was utilized to examine selected site characteristics at each levee failure location. These site characteristics (levee failure parameters) included: 1) levee underlain by previous channel fill, 2) presence/absence of borrow pit, 3) location of failure on a meander bend, 4) width of channel, 5) width of floodway, 6) constriction-over-time factor, 7) land-cover type, 8) width of vegetative buffer, 9) sinuosity of channel, 10) intensity of dredging, and 11) presence/absence of bank revetment. Each of these parameters was evaluated using geologic maps, soil survey data, Digital Elevation Models (DEMs), historic river maps, and dredging reports (Winkley, 1977; Pinter et al., 2004). Two models were created for each river reach. The first model for both reaches used a 95% significance threshold, while the second model for the MMR used a 80% significance threshold, and the second model for the LMR used a 90% significance threshold. The first model for the Middle Mississippi River (MMR) identified only the presence/absence of channel fills to predict levee failure as significant, had an R² value of 0.178, a p-value of 0.002, and a percentage accuracy of 68.6%. The second model for the MMR identified the following variables as significant: presence/absence of channel fills to predict levee failure, location of failure on a meander bend, channel width, land-cover type, and intensity of dredging. This model had an R2 value of 0.408, p-value of 0.002, and a percentage accuracy of 74.3%. The 95% model for the Lower Mississippi River (LMR) identified location of failure on a meander bend, land-cover type, constriction-over-time factor, and sinuosity of the channel as significant. This model had an R2 value of 0.326, p-value of 0.003, and a percentage accuracy of 69.5%. The 90% LMR model identified the following variables as significant: the presence/absence of borrow pits, location of failure on meander bend, channel width, land-cover type, constriction-over-time factor, vegetative buffer width, channel sinuosity, and presence/absence of bank revetment. This model had an R2 value of 0.385, p-value of 0.006, and a percentage accuracy of 72.0%. The MMR and LMR models with the 95% significance threshold had no predictors in common because of differences between the two river reaches or possibly because of the small sample size. However, the expanded MMR and LMR models shared three predictors (i.e., meander location, channel width, and land cover type). The second portion of this project used post-processed dual-frequency GPS surveying to measure levee elevations between St. Louis, MO and Cairo, IL. These elevations were compared to the 50-year design flood grade elevations and to a 1998 DEM to identify areas of levee heightening, levee degradation and/or subsidence, and locations of past levee crevasses. This surveying revealed areas that, between 1998 and 2007, were raised up to ~1.5 meters and other areas that degraded or subsided up to ~1.0 meter. Also, the locations of five recent levee crevasses were investigated, showing local increases or decreases at those points. The importance of levee road construction type was identified through many sharp increases or decreases at the transition between road types. Overall, this project showed promising implications for the determination of levee failure susceptibility and proper levee elevation heights using logistic regression analysis and kinematic GPS surveying. The logistic regression models predicted the potential for levee failure based on local site characteristics of levees between St. Louis, MO and Memphis, TN. The high-precision kinematic GPS surveying illustrated levee elevations along the MMR to a high degree of accuracy, allowing for the rapid and efficient identification of areas that do not correspond to the proper design flood grade elevation.

The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.

The main goal of this research is to investigate vulnerability of levees to future slump slides. In the first part, polarimetric synthetic aperture radar (PolSAR) imagery is used as input in an automated classification system for characterizing areas on the levee having anomalies. In addition, a set of in-situ soil data is collected to provide detailed soil properties over the study area. In-situ soil properties of different classes characterized by the classifier are analyzed to determine how similarities between different areas. The second part, a database including of 34 slump slides that occurred in the lower Mississippi River levee system over a period of two years is used. The impacts of rainfall as well as several spatial geometrical and geomorphological variables (including channel width, river sinuosity index, riverbank erosion, channel shape condition and distance to river) are analyzed and tested for significance and used for developing a logistic regression model.

Levees are a significant part of the United States flood protection infrastructure. It is estimated that over 100,000 miles of levees exist in the United States. Most of these levees were designed many years ago to protect farmland and rural areas. As growth continues in the United States, many of these levees are now protecting homes and other important structures. The American Society of Civil Engineers gave the levees in the United States a grade of D- in 2009. To bring flood protection up to modern standards there requires adequate methods of evaluating levees with respect to seepage, erosion, piping and slope instability. Transient seepage analyses provide an effective method of evaluating seepage through levees and its potentially destabilizing effects. Floods against levees usually last for days or weeks. In response to a flood, pore pressures within the levee will change from negative (suction) to positive as the phreatic surface progresses through the levee. These changes can be calculated by finite element transient seepage analyses. In order for the transient seepage analysis to be valid, appropriate soil properties and initial conditions must be used. The research investigation described here provides simple and practical methods for estimating the initial conditions and soil properties required for transient seepage analyses, and illustrates their use through a number of examples. / Ph. D.

Due to inadequate long-term and large-scale observation approach for observation of soil moisture across the globe, this study intends to unveil the importance of using simulated soil moisture fields from land surface models, forced with observed precipitation and near-surface meteorology in monitoring drought and formulating effective water management practices for continued production irrigation applications. This study shows that socio-economic and ecosystem effects can be determined by evaluating spatial-temporal changes in irrigation applications. Thus, it facilitates understanding of the importance of water management and how water, energy, and carbon flows protect our climate and environment. By using Soil Moisture Active Passive (SMAP) in monitoring soil moisture, the information obtained is critical in providing early drought warnings, particularly in those parts of the United States that experience flash agricultural droughts. Further, this study highlights that frequent and reliable soil moisture measurements from SMAP helped improve the predictive capability of weather and climate models.