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Mallard II
''Mallard II'' is a wooden-hulled clamshell dredger used to maintain levees on the San Francisco Bay Salt Ponds. ''Mallard II'' was constructed in 1936, and is "probably the oldest operating dredge in California"; she is owned and operated by Cargill Salt. History ''Mallard II'' was built by the Leslie Salt Company (now Cargill) in 1936, and has maintained the levees of the salt ponds ever since, except for a brief period during World War II during which she was used to retrieve artillery shells from the floor of the Bay near Mare Island and the Port Chicago Naval Magazine. Over time, she received extensive upgrades (including a modern engine, steel A-frame and boom). The steel frame was installed by Bethelehem Pacific's San Francisco shipyard in 1954, at which point she maintained levees on over of ponds in the South Bay as well as Napa County. She has been described as a "floating wood-and-metal dinosaur", with a bucket capable of moving as much as of mud per day. Whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dumbarton Bridge (California)
The Dumbarton Bridge is the southernmost of the highway bridges across San Francisco Bay in California. Carrying over 70,000 vehicles and about 118 pedestrian and bicycle crossings daily (384 on weekends), it is the shortest bridge across San Francisco Bay at . Its eastern end is in Fremont, near Newark in the San Francisco Bay National Wildlife Refuge, and its western end is in Menlo Park. Bridging State Route 84 across the bay, it has three lanes each way and a separated bike/pedestrian lane along its south side. Like the San Mateo Bridge to the north, power lines parallel the bridge. History and engineering features The bridge has never been officially named, but its commonly used name comes from Dumbarton Point, named in 1876 after Dumbarton, Scotland. Built originally to provide a shortcut for traffic originating in San Mateo and Santa Clara counties, the bridge served industrial and residential areas on both sides. The earlier bridge opened on January 17, 1927, and was t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Army Corps Of Engineers
, colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = LTG Scott A. Spellmon , commander1_label = Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers , commander2 = MGbr>Richard J. Heitkamp, commander2_label = Deputy Chief of Engineers and Deputy Commanding General , commander3 = MGKimberly M. Colloton, commander3_label = Deputy Commanding General for Military and International Operations , commander4 = MGbr>William H. Graham, commander4_label = Deputy Commanding General for Civil and Emergency Operations , commander5 = COLbr>James J. Handura, commander5_label = Chief of Staff for the U.S. Army Corps of Engi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California Department Of Fish And Wildlife
The California Department of Fish and Wildlife (CDFW), formerly known as the California Department of Fish and Game (CDFG), is a state agency under the California Natural Resources Agency. The Department of Fish and Wildlife manages and protects the state's wildlife, wildflowers, trees, mushrooms, algae (kelp) and native habitats (ecosystems). The department is responsible for regulatory enforcement and management of related recreational, commercial, scientific, and educational uses. The department also prevents illegal poaching. History The Game Act was passed in 1852 by the California State Legislature and signed into law by Governor John Bigler. The Game Act closed seasons in 12 counties for quail, partridge, mallard and wood ducks, elk, deer, and antelope. A second legislative action enacted the same year protected salmon runs. In 1854, the Legislature extended the act to include all counties of California. In 1860, protection controls were extended for trout. Lake Merritt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrow Pit
Digging, also referred to as excavation, is the process of using some implement such as claws, hands, manual tools or heavy equipment, to remove material from a solid surface, usually soil, sand or rock on the surface of Earth. Digging is actually the combination of two processes, the first being the breaking or cutting of the surface, and the second being the removal and relocation of the material found there.Carl Dreher,The Right Way to Dig, ''Popular Science'' (March 1957), p. 179. In a simple digging situation, this may be accomplished in a single motion, with the digging implement being used to break the surface and immediately fling the material away from the hole or other structure being dug. Many kinds of animals engage in digging, either as part of burrowing behavior or to search for food or water under the surface of the ground.Zen Faulkes,Morphological Adaptations for Digging and Burrowing (2013), p. 276-295. Historically, humans have engaged in digging for both of thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clamshell Bucket
A bucket (also called a scoop to qualify shallower designs of tools) is a specialized container attached to a machine, as compared to a bucket adapted for manual use by a human being. It is a bulk material handling component. The bucket has an inner volume as compared to other types of machine attachments like blades or shovels. The bucket could be attached to the lifting hook of a crane, at the end of the arm of an excavating machine, to the wires of a dragline excavator, to the arms of a power shovel or a tractor equipped with a backhoe loader or to a loader, or to a dredge. The name "bucket" may have been coined from buckets used in water wheels, or used in water turbines or in similar-looking devices. Purposes Buckets in mechanical engineering can have a distinct quality from the traditional bucket (pail) whose purpose is to contain things. Larger versions of this type of bucket equip bucket trucks to contain human beings, buckets in water-hauling systems in mines or, for i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lock (water Navigation)
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the chamber itself (usually then called a caisson) that rises and falls. Locks are used to make a river more easily navigable, or to allow a canal to cross land that is not level. Later canals used more and larger locks to allow a more direct route to be taken. Pound lock A ''pound lock'' is most commonly used on canals and rivers today. A pound lock has a chamber with gates at both ends that control the level of water in the pound. In contrast, an earlier design with a single gate was known as a flash lock. Pound locks were first used in China during the Song Dynasty (960–1279 AD), having been pioneered by the Song politician and naval ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subsidence
Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, which distinguishes it from slope movement. Processes that lead to subsidence include dissolution of underlying carbonate rock by groundwater; gradual compaction of sediments; withdrawal of fluid lava from beneath a solidified crust of rock; mining; pumping of subsurface fluids, such as groundwater or petroleum; or warping of the Earth's crust by tectonic forces. Subsidence resulting from tectonic deformation of the crust is known as tectonic subsidence and can create accommodation for sediments to accumulate and eventually lithify into sedimentary rock. Ground subsidence is of global concern to geologists, geotechnical engineers, surveyors, engineers, urban planners, landowners, and the public in general.National Research Council, 1991. ''Mitigating losses from land subsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion procee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Francisco Bay Area
The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Governments to include the nine counties that border the aforementioned estuaries: Alameda, Contra Costa, Marin, Napa, San Mateo, Santa Clara, Solano, Sonoma, and San Francisco. Other definitions may be either smaller or larger, and may include neighboring counties that do not border the bay such as Santa Cruz and San Benito (more often included in the Central Coast regions); or San Joaquin, Merced, and Stanislaus (more often included in the Central Valley). The core cities of the Bay Area are San Francisco, San Jose, and Oakland. Home to approximately 7.76 million people, Northern California's nine-county Bay Area contains many cities, towns, airports, and associated regional, state, and national parks, connected by a comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Reclamation
Land reclamation, usually known as reclamation, and also known as land fill (not to be confused with a waste landfill), is the process of creating new land from oceans, seas, riverbeds or lake beds. The land reclaimed is known as reclamation ground or land fill. In some jurisdictions, including parts of the United States, the term "reclamation" can refer to returning disturbed lands to an improved state. In Alberta, Canada, for example, reclamation is defined by the provincial government as "The process of reconverting disturbed land to its former or other productive uses." In Oceania, it is frequently referred to as land rehabilitation. History One of the earliest large-scale projects was the Beemster Polder in the Netherlands, realized in 1612 adding of land. In Hong Kong the Praya Reclamation Scheme added of land in 1890 during the second phase of construction. It was one of the most ambitious projects ever taken during the Colonial Hong Kong era.Bard, Solomon. 002 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Jose, California
San Jose, officially San José (; ; ), is a major city in the U.S. state of California that is the cultural, financial, and political center of Silicon Valley and largest city in Northern California by both population and area. With a 2020 population of 1,013,240, it is the most populous city in both the Bay Area and the San Jose–San Francisco–Oakland, CA Combined Statistical Area, San Jose-San Francisco-Oakland Combined Statistical Area, which contain 7.7 million and 9.7 million people respectively, the List of largest California cities by population, third-most populous city in California (after Los Angeles and San Diego and ahead of San Francisco), and the List of United States cities by population, tenth-most populous in the United States. Located in the center of the Santa Clara Valley on the southern shore of San Francisco Bay, San Jose covers an area of . San Jose is the county seat of Santa Clara County, California, Santa Clara County and the main component of the San ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redwood City, California
Redwood City is a city on the San Francisco Peninsula in Northern California's Bay Area, approximately south of San Francisco, and northwest of San Jose. Redwood City's history spans its earliest inhabitation by the Ohlone people to being a port for lumber and other goods. The county seat of San Mateo County in the heart of Silicon Valley, Redwood City is home to several global technology companies including Oracle, Electronic Arts, Evernote, Box, and Informatica. The city's population was 84,292 according to the 2020 census. The Port of Redwood City is the only deepwater port on San Francisco Bay south of San Francisco. According to the United States Census Bureau, the city has an area of , of which is land and (44.34%) is water. A major watercourse draining much of Redwood City is Redwood Creek, to which several significant river deltas connect, the largest of which is Westpoint Slough. History The earliest known inhabitants of the area which was to become Redwoo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
