975 resultados para flooding


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pt.1. Oil and gas developments, [by] Alfred H. Bell, Virginia Kline -- pt. 2. Waterflood operations, [by] Paul A. Witherspoon, Donald A. Pierre.

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pt. 1. Oil and gas developments. Introduction -- Production and value -- Drilling and development -- Productive acreage -- Estimated petroleum reserves -- Gas and gas products -- Underground gas storage -- County reports -- pt. 2. Waterflood operations. Introduction -- Summary of results -- Project numbers, by county -- Illinois waterflood projects operating during 1957 -- Illinois waterflood projects reported abandoned -- Illinois pressure maintenance projects using water injection during 1957.

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Description of a project to reduce ponding and flooding in Cortland by construction of a storm sewer and detention basin for runoff.

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Includes pages and exhibits from the Christopher B. Burke Engineering, Ltd. report analyzing the problems and recommending remedial measures to mitigate flooding in Lemont.

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A recommendation to use a portion of the Illinois General Assembly's appropriation for the Wood River Drainage and Levee District--funds to help defray the District's funding requirements associated with U.S. Army Corps of Engineers' projects--for the construction of the Grassy Lake Pump Station to alleviate interior flooding within the District.

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In November 2006, the flood of record on the upper Nisqually River destroyed part of Sunshine Point Campground in Mount Rainier National Park, Washington. The Nisqually River migrated north and reoccupied five acres of its floodplain; Tahoma Creek partially avulsed into the west floodplain, topping banks of an undersized channel and flooding the campground. I assessed hazards to infrastructure at the old campground location, where the Park proposes to rebuild the remaining campground roads and sites. This assessment focuses on two major hazards: northward Nisqually River migration, which may reincorporate the floodplain into the river destroying infrastructure; and Tahoma Creek avulsions, which may flood the campgroud and deposit sediment burying campground infrastructure. I quantify northward migration by: estimating migration rates and changes to channel width; evaluating river occupation of the pre- and post-2006 campground; and estimating scour depths at revetments protecting the campground. I digitized the Nisqually River channels and channel centerlines from maps and images between 1955 and 2013 into a GIS, which I used to estimate migration rate and river width changes. Centerline migration rates average 9 ft/yr along the length of the Nisqually River study reach; at Sunshine Point lateral migration rates average 11 ft/yr. Maximum migration along the study reach was 19 ft/yr between 2006 and 2009. Greater than average migration rates and channel widths correspond to river confluences and include the Tahoma Creek confluence at Sunshine Point. To determine historical channel locations and the frequency that the river occupied different parts of its floodplain, I digitized the river from maps and images between 1903 and 2013. The Nisqually River flows through Sunshine Point Campground in eight out of 15 historical images. I assess scour at revetments protecting infrastructure from the Nisqually River during a 100-year recurrence interval flood using measured cross-sections. During a 100-year flood, the Nisqually River may scour up to 10 feet below the bed elevation. These scour depths can destabilize critical revetments leaving loose unconsolidated riverbanks exposed to Nisqually River flows. To determine the causes, locations, and frequency of flood hazards from Tahoma Creek avulsions, I field map avulsion channels and compare the results with imagery and channel width changes between 1955 and 2013. Mapped avulsion channels occur with swaths of dead vegetation or nascent vegetation; both dead and recent vegetation are visibly distinct from surrounding vegetation in aerial images. Times of changes to these vegetation anomalies correspond to increases in Tahoma Creek channel width. Avulsions have occurred at least three times in the study period: pre-1955, between 1979 and 1984, and in 2006. The 1984 and 2006 avulsions both occur after increases in Tahoma Creek reach averaged width. The NPS is considering two options to rebuild Sunshine Point Campground, both at the same location. The hazards posed by the Nisqually River and Tahoma Creek at Sunshine Point will affect both construction options equally. Migration hazards to the campground may be reduced by limiting the proposed campground infrastructure to an elevated ridge that has not been occupied by the Nisqually River since 1903. The hazards of damage from migration may be reduced by revetments, which were effective in preventing northward Nisqually River migration in 1959 and 1965. Tahoma Creek avulsions are related increased of Tahoma Creek reach averaged widths, which are near a 58- year maximum, and occurred during a 10-year flood in 1984. The campground may be as susceptible to flooding from avulsions during as little as a 10-year flood. A large avulsion may occur with the next significant Tahoma Creek width increase. Glacial retreat has been shown to increase debris flow activity and increase sediment delivery to Mount Rainier rivers. Increased sediment discharge has been correlated with aggradation, which will further encourage Tahoma Creek avulsions.

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In September 2013, the Colorado Front Range experienced a five-day storm that brought record-breaking precipitation to the region. As a consequence, many Front Range streams experienced flooding, leading to erosion, debris flows, bank failures and channel incision. I compare the effects that debris flows and flooding have on the channel bar frequency, frequency and location of wood accumulation, and on the shape and size of the channel along two flood impacted reaches located near Estes Park and Glen Haven, Colorado within Rocky Mountain National Park and Arapaho-Roosevelt National Forest: Black Canyon Creek (BCC) and North Fork Big Thompson River (NFBT). The primary difference between the two study areas is that BCC was inundated by multiple debris flows, whereas NFBT only experienced flooding. Fieldwork consisted of recording location and size of large wood and channel bars and surveying reaches to produce cross-sections. Additional observations were made on bank failures in NFBT and the presence of boulders in channel bars in BCC to determine sediment source. The debris flow acted to scour and incise BCC causing long-term alteration. The post-flood channel cross-sectional area is as much as 7 to 23 times larger than the pre-flood channel, caused by the erosion of the channel bed to bedrock and the elimination of riparian vegetation. Large wood was forced out of the stream channel and deposited outside of the bankfull channel. Flooding in NFBT caused bank erosion and widening that contributed sediment to channel bars, but accomplished little stream-bed scour. As a result, there was relatively little damage to mid-channel and riparian vegetation, and most large wood remained within the wetted channel.

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A specific type of natural log jam in the upper alluvial reach of the Carbon River was found to influence secondary channel avulsion, causing flooding hazards to the adjacent Carbon River Road in the northwest quadrant of Mount Rainier National Park, Washington. The fence-like natural log jam was characterized by large woody debris buttressed horizontally against standing riparian trees (i.e. ìfence railsî and ìfence postî). The objectives of this report are two-fold. First, physical characteristics and spatial distribution were documented to determine the geomorphic controls on the fence-like log jams. Second, the function and timing of the natural log jam in relation to channel avulsion was determined to provide insight into flooding hazards along the Carbon River Road. The fence-like log jams are most abundant in the upper reaches of the Carbon River between 3.0 and 5.5 kilometers from the Carbon Glacier terminus, where longitudinal gradient significantly decreases from about 0.06 to 0.03. Sediment impoundment can occur directly upstream of the fence-like log jam, creating vertical bed elevation difference as high as 1.32 meters, and can form during low magnitude, high frequency flood event (3.5-year recurrence interval). In some locations, headcuts and widening of secondary channel were observed directly to the side of the log jams, suggesting its role in facilitating secondary channel avulsions. Areas along the Carbon River Road more prone to damages from avulsion hazards were identified by coupling locations of the log jams and Relative Water Surface Elevation map created using the 1-meter 2012 Light Detection and Ranging Digital Elevation Map. Ultimately, the results of this report may provide insight to flooding hazards along the Carbon River Road from log jam-facilitated channel avulsion.

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Thesis (Master's)--University of Washington, 2016-06

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Spatial gradients in mangrove tree height in barrier islands of Belize are associated with nutrient deficiency and sustained flooding in the absence of a salinity gradient. While nutrient deficiency is likely to affect many parameters, here we show that addition of phosphorus (P) to dwarf mangroves stimulated increases in diameters of xylem vessels, area of conductive xylem tissue and leaf area index (LAI) of the canopy. These changes in structure were consistent with related changes in function, as addition of P also increased hydraulic conductivity (K-s), stomatal conductance and photosynthetic assimilation rates to the same levels measured in taller trees fringing the seaward margin of the mangrove. Increased xylem vessel size and corresponding enhancements in stern hydraulic conductivity in P fertilized dwarf trees came at the cost of enhanced midday loss of hydraulic conductivity and was associated with decreased assimilation rates in the afternoon. Analysis of trait plasticity identifies hydraulic properties of trees as more plastic than those of leaf structural and physiological characteristics, implying that hydraulic properties are key in controlling growth in mangroves. Alleviation of P deficiency, which released trees from hydraulic limitations, reduced the structural and functional distinctions between dwarf and taller fringing tree forms of Rhizophora mangle.

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Soil absorption systems (SAS) are used commonly to treat and disperse septic tank effluent (STE). SAS can hydraulically fail as a result of the low permeable biomat zone that develops on the infiltrative surface. The objectives of this experiment were to compare the hydraulic properties of biomats grown in soils of different textures, to investigate the long-term acceptance rates (LTAR) from prolonged application of STE, and to assess if soils were of major importance in determining LTAR. The STE was applied to repacked sand, Oxisol and Vertisol soil columns over a period of 16 months, at equivalent hydraulic loading rates of 50, 35 and 8 L/m(2)/d, respectively Infiltration rates, soil matric potentials, and biomat hydraulic properties were measured either directly from the soil columns or calculated using established soil physics theory. Biomats 1 to 2 cm thick developed in all soils columns with hydraulic resistances of 27 to 39 d. These biomats reduced a 4 order of magnitude variation in saturated hydraulic conductivity (K.) between the soils to a one order of magnitude variation in LTAR. A relationship between biomat resistance and organic loading rate was observed in all soils. Saturated hydraulic conductivity influenced the rate and extent of biomat development. However, once the biomat was established, the LTAR was governed by the resistance of the biomat and the sub-biomat soil unsaturated flow regime induced by the biomat. Results show that whilst initial soil K. is likely to be important in the establishment of the biomat zone in a trench, LTAR is determined by the biomat resistance and the unsaturated soil hydraulic conductivity, not the K, of a soil. The results call into question the commonly used approach of basing the LTAR, and ultimately trench length in SAS, on the initial K, of soils. (c) 2006 Elsevier Ltd. All rights reserved.

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The operation of polymer electrolyte membrane fuel cells (PEMFCs) with dry feeds has been examined with different fuel cell flow channel designs as functions of pressure, temperature and flow rate. Auto-humidified (or self-humidifying) PEMFC operation is improved at higher pressures and low gas velocities where axial dispersion enhances back-mixing of the product water with the dry feed. We demonstrate auto-humidified operation of the channel-less, self-draining fuel cell, based on a stirred tank reactor; data is presented showing auto-humidified operation from 25 to 115 degrees C at 1 and 3 atm. Design and operating requirements are derived for the auto-humidified operation of the channel-less, self-draining fuel cell. The auto-humidified self-draining fuel cell outperforms a fully humidified serpentine flow channel fuel cell at high current densities. The new design offers substantial benefits for simplicity of operation and control including: the ability to self-drain reducing flooding, the ability to uniformly disperse water removing current gradients and the ability to operate on dry feeds eliminating the need for humidifiers. Additionally, the design lends itself well to a modular design concept. (c) 2005 Elsevier B.V. All rights reserved.