161 resultados para Waterway


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通过对单厢式矩形断面、单厢式梯形断面、迷宫式、旋流式等 4种结构形成的沉沙池沉沙效率对比试验表明 ,以迷宫式沉沙池效果最佳 ,平均沉沙效率可达 88.3%。此种结构形式的断面尺寸为 1m、宽 0 .4m ,迷宫室底部比集水渠低 0 .2 m,迷宫分成 5个小厢室 ,每个厢室长 0 .146 m,沉沙池首部的静水池深 0 .2 5 m

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This paper presents the findings from an experimental investigation in to the nature and extent of the scouring that occurs when a ship berths in front of a perpendicular quay wall within the confines of a harbor. It examines the interaction between the relative position of the quay wall to the central axis of the ship and the influence of angle of the vessel's rudder on the magnitude of the scouring produced. The experimental programme covered a range of sediment sizes, propeller diameters and speeds of rotation and rudder angles. Also, methods for calculating the depth of expected scour are presented in terms of initial semi-empirical equations for the data range under investigation.

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As a consequence of increased levels of flooding, largely attributable to urbanization of watersheds (and perhaps climate change, more frequent extreme rainfall events are occurring and threatening existing critical infrastructure. Many of which are short-span bridges over relatively small waterways (e.g., small rivers, streams and canals). Whilst these short-span bridges were designed, often many years ago, to pass relatively minor the then standard return-period floods, in recenttimes the failure incidence of such short-span bridges has been noticeably increasing. This is suggestive of insufficient hydraulic capacity or alternative failure mechanism not envisaged at the time of design e.g. foundation scour or undermining. This paper presen ts, and draws lessons, from bridge failures in Ireland and the USA. For example, in November 2009, the UK and Ireland were subjected to extraordinarily severe weather conditions for several days. The resulting flooding led to the collapse of three UK bridges that were generally 19th century masonry arch bridges, withrelatively shallow foundations. Parallel failure events have been observed in the USA. To date, knowledge of the combined effect of waterway erosion, bridge submergence, and geotechnical collapse has not been adequately studied. Recent research carried out considered the hydraulic analysis of short span bridges under flood conditions, but no consideration was given towards the likely damage to these structures due to erosive coupling of hydraulic and geotechnical factors. Some work has been done to predict the discharge downstream of an inundated arch, focusing onpredicting afflux, as opposed to bridge scour, under both pressurized and free-surface flows, but no ! predictive equation for scour under pressurized conditions was ever considered. The case studies this paper presents will be augmented by the initial findings from the laboratory experiments investigating the effects of surcharged flow and subsequent scour within the vicinity of single span arch bridges. Velocities profiles will be shown within the vicinity of the arch, in addition to the depth of consequent scour, for a series of flows and model spans. The data will be presented and correlated to the most recent predictive equations for submerged contraction and abutment scour. The accuracy of these equations is examined, and the findings used as a basis for developing further studies in relation to short span bridges.

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Salmonid populations of many rivers are rapidly declining. One possible explanation is that habitat fragmentation increases genetic drift and reduces the populations' potential to adapt to changing environmental conditions. We measured the genetic and eco-morphological diversity of brown trout (Salmo trutta) in a Swiss stream system, using multivariate statistics and Bayesian clustering. We found large genetic and phenotypic variation within only 40 km of stream length. Eighty-eight percent of all pairwise F(ST) comparisons and 50% of the population comparisons in body shape were significant. High success rates of population assignment tests confirmed the distinctiveness of populations in both genotype and phenotype. Spatial analysis revealed that divergence increased with waterway distance, the number of weirs, and stretches of poor habitat between sampling locations, but effects of isolation-by-distance and habitat fragmentation could not be fully disentangled. Stocking intensity varied between streams but did not appear to erode genetic diversity within populations. A lack of association between phenotypic and genetic divergence points to a role of local adaptation or phenotypically plastic responses to habitat heterogeneity. Indeed, body shape could be largely explained by topographic stream slope, and variation in overall phenotype matched the flow regimes of the respective habitats.

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Ontario Editorial Bureau (O.E.B.)

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Survey map of the Second Welland Canal created by the Welland Canal Company along the western edge of the Town of St. Catharines. Although not labelled, the Second Welland Canal can be seen running through the map along with its tow path, which is located on the southwestern edge of the waterway. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are identified and include streets and roads (ex. Ontario Street and Road to Hamilton), Artesian Mineral Well, Dr. Mack's Artesian Well, Stephenson House Mineral Well and Gas Works, New Brewery, Old Brewery, Welland House Mineral Well, L. Shickluna's Shipyard, Vinegar Manufactory, Merritt's Covered Race, Mitchels Wharf, Sail Loft, an office, a tavern, two barns, a boathouse, a structure belonging to T. Nihan (or P. Nihen), and some store houses. Properties and property owners of note are: Concession 6 Lot 20, William H. Merritt, E. S. Adams, William Chace, Jacob Hainer, J. Taylor, and J. P. Merritt.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the Town of St. Catharines. Identified structures associated with the Canal include Lock 4, Hydraulic Race, floating tow path, and the Canal waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include streets and roads (ex. Geneva Street, St. Paul Street, Queenston Street, Niagara Street and Mill Street), C. Phelp's Grist Mill and Store House, Stinson's Distillery, and several unnamed bridges. Properties and property owners of note are: Concession 6 Lot 16, J. R. Benson, Calvin Phelps, J. Hudson, David Gray, A. Roberts, Mrs. McDonell, J. S. McDonell, T. B. Wragg, J. Donaldson, W. Barr Jr., C. L. Hall, G. Ward, Ridout Bros and Co., and the St. Catharines Grass Co.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the Grantham Township between the Town of St. Catharines and Merritton. Identified structures associated with the Canal include Locks 9 and 10, waste weirs, the towing path, a 2nd towing path, and the Canal waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include roads (ex. Road to Centreville), hydraulic race, and the Centreville Mill. Properties and property owners of note are: Concession 8 Lots 12 and 12, Lewis Traver, Richard Ash, John Bradley, Owen Clifford, Orson Phelps, C. Bradley, the W. C. Loan Company, and T. Towers Mill Lot.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the canal along Chippewa Creek in Thorold Township. Identified structures and features associated with the Canal include the towing path, float bridge, and the waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include a road allowance between Lot 213 and 214, Chippewa Creek, an unnamed creek, and the Old Canal. Wetlands adjacent to Chippewa Creek are illustrated. Properties and property owners of note are: Lots 213 and 214, Samuel Hill, and Duncan Coleman. The boundary of the land deeded to Coleman is outlined in blue.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the canal along Chippewa Creek in Thorold Township. Identified structures and features associated with the Canal include the towing path, the back ditch, and the waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include roads (ex. Road to Welland), Chippewa Creek, and a pond. Properties and property owners of note are: Lots 214, 215, 216 and 222, and Heaslip.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the canal in the Thorold Township between Port Robinson and Welland. Identified structures and features associated with the Canal include the towing path, a ditch, and the waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include a road allowance between two lots, the Spoil Bank, and a pond. Properties and property owners of note are: Lot 222, 223, and 215, Hagar, Alem Marr, and Heaslip.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the canal in the Thorold Township between Port Robinson and Welland. Identified structures and features associated with the Canal include the towing path, back ditch, and the waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include roads and streets (ex. Road to Port Robinson), Quaker Bridge, Hagar's Wood Wharf, Spoil Bank, and several ponds. Properties and property owners of note are: Lots 222, 223, and 224, Johnathan Hagar, E. Shotwell, and Alem Marr.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the canal in the Thorold Township between Port Robinson and Welland. Identified structures and features associated with the Canal include the towing path, back ditches, and the waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include several road allowances, two bridges(Northern most bridge would be the Quaker Bridge), Spoil Bank, two ponds, and several fences. Properties and property owners of note are: Lot 229, and Jacob Silverthorne.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the canal in the Thorold Township between Port Robinson and Welland. Identified structures and features associated with the Canal include the towing path, a ditch, foot of the slope of bank, and the waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include roads (ex. Road to Wellandville), a bridge, a marsh, Spoil Bank, and a fence running along the canal. Properties and property owners of note are: Lot 238, Broken Lot 238, and J. Burger.

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Survey map of the Second Welland Canal created by the Welland Canal Company showing the canal as it crosses Chippewa Creek in the Thorold Township near Welland. Identified structures and features associated with the Canal include the towing path, the old canal, the aqueduct lock, the new aqueduct, and the waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include roads (ex. Aqueduct Road, and Road to Weland), Chippewa Creek, the Spoil Bank, a house and a barn. Properties and property owners of note are: Lots 239, 247, and 248, Joseph Burgar, and Smith Shotwell.