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St. Francis Dam
The St. Francis Dam was a concrete gravity dam located in San Francisquito Canyon in Los Angeles County, California, United States, built from 1924 to 1926 to serve Los Angeles's growing water needs. It catastrophically failed in 1928 due to a defective soil foundation and design flaws, triggering a flood that claimed the lives of at least 431 people. The collapse of the dam is considered to be one of the worst American civil engineering disasters of the 20th century and remains the second-greatest loss of life in California's history, after the 1906 San Francisco earthquake and fire. The St. Francis Dam was built to create a large regulating and storage reservoir that was an integral part of the Los Angeles Aqueduct. It was located in San Francisquito Canyon of the Sierra Pelona Mountains, about northwest of downtown Los Angeles, and approximately north of the present day city of Santa Clarita, California. The dam was designed and built between 1924 and 1926 by the Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Francisquito Canyon
San Francisquito Canyon is a canyon created through erosion of the Sierra Pelona Mountains by the San Francisquito Creek, in Los Angeles County, Southern California. Geography The canyon cuts through the Sierra Pelona Mountains, which are central part of the Transverse Ranges system of California. At the San Francisquito Canyon head is the San Francisquito Pass, which the early routes between Los Angeles and the San Joaquin Valley crossed. The canyon grows wider as it approaches the Santa Clarita Valley. The middle and upper portions of this canyon fall within the Angeles National Forest. History Mining San Francisquito Canyon was the site of placer mining for gold by Spanish missionaries from the San Fernando and San Buenaventura Missions, and later by Mexican Californios. Their activity stopped in 1848, when the gold discovery at Sutter's Mill started the California Gold Rush. Placer mining later occurred in the canyon into at least the late 19th century. St. Francis D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles Department Of Water And Power
The Los Angeles Department of Water and Power (LADWP) is the largest municipal utility in the United States with 8,100 megawatts of electric generating capacity (2021-2022) and delivering an average of 435 million gallons of water per day to more than four million residents and local businesses in the City of Los Angeles. It was founded in 1902 to supply water to residents and businesses in the Los Angeles and surrounding communities. In 1917, it began to deliver electricity to portions of the city. It has been involved in a number of controversies and media portrayals over the years, including the 1928 St. Francis Dam failure and the books ''Water and Power'' and ''Cadillac Desert''. History Private operators By the middle of the 19th century, Los Angeles's rapid population growth magnified problems with the city's water distribution system. At that time, a system of open, often polluted ditches, was reasonably effective at supplying water for agricultural production but was n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles County
Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the most populous county in the United States and in the U.S. state of California, with 9,861,224 residents estimated as of 2022. It is the most populous non–state-level government entity in the United States. Its population is greater than that of 40 individual U.S. states. At and with 88 incorporated cities and many unincorporated areas, it is home to more than one-quarter of California residents and is one of the most ethnically diverse counties in the United States. Its county seat, Los Angeles, is also California's most populous city and the second-most populous city in the United States, with about 3.9 million residents. In recent times, statewide droughts in California have placed great strain on the County’s (and the City of Los Angeles's) water security. History Los Angeles County is one of the original counties of California, created at the time of stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics with the major subdisciplines of number theory, algebra, geometry, and analysis, respectively. There is no general consensus among mathematicians about a common definition for their academic discipline. Most mathematical activity involves the discovery of properties of abstract objects and the use of pure reason to prove them. These objects consist of either abstractions from nature orin modern mathematicsentities that are stipulated to have certain properties, called axioms. A ''proof'' consists of a succession of applications of deductive rules to already established results. These results include previously proved theorems, axioms, andin case of abstraction from naturesome basic properties that are considered true starting points of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topography
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary science and is concerned with local detail in general, including not only relief, but also natural, artificial, and cultural features such as roads, land boundaries, and buildings. In the United States, topography often means specifically ''relief'', even though the USGS topographic maps record not just elevation contours, but also roads, populated places, structures, land boundaries, and so on. Topography in a narrow sense involves the recording of relief or terrain, the three-dimensional quality of the surface, and the identification of specific landforms; this is also known as geomorphometry. In modern usage, this involves generation of elevation data in digital form (DEM). It is often considered to include the graphic representation of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroelectricity
Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewable energy, renewable sources combined and also more than nuclear power. Hydropower can provide large amounts of Low-carbon power, low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once a hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel-powered energy plants. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word ''tremor'' is also used for Episodic tremor and slip, non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drought
A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, and O. Zolina, 2021Water Cycle Changes In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1055–1210, doi:10.1017/9781009157896.010. This means that a drought is "a moisture deficit relative to the average water availability at a given location and season". A drought can last for days, months or years. Drought ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sabotage
Sabotage is a deliberate action aimed at weakening a polity, effort, or organization through subversion, obstruction, disruption, or destruction. One who engages in sabotage is a ''saboteur''. Saboteurs typically try to conceal their identities because of the consequences of their actions and to avoid invoking legal and organizational requirements for addressing sabotage. Etymology The English word derives from the French word , meaning to "bungle, botch, wreck or sabotage"; it was originally used to refer to labour disputes, in which workers wearing wooden shoes called interrupted production through different means. A false etymology, popular but incorrect account of the origin of the term's present meaning is the story that poor workers in the Belgian city of Liège would throw a wooden into the machines to disrupt production. One of the first appearances of and in French literature is in the of d'Hautel, edited in 1808. In it the literal definition is to 'make nois ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Owens Valley
Owens Valley (Numic Numic is a branch of the Uto-Aztecan language family. It includes seven languages spoken by Native American peoples traditionally living in the Great Basin, Colorado River basin, Snake River basin, and southern Great Plains. The word Numic com ...: ''Payahǖǖnadǖ'', meaning "place of flowing water") is an arid valley of the Owens River in eastern California in the United States. It is located to the east of the Sierra Nevada (U.S.), Sierra Nevada, west of the White Mountains (California), White Mountains and Inyo Mountains, and north of the Mojave Desert. It sits on the west edge of the Great Basin section, Great Basin. The mountain peaks on the West side (including Mount Whitney) reach above in elevation, while the floor of the Owens Valley is about , making the valley the deepest in the United States. The Sierra Nevada casts the valley in a rain shadow, which makes Owens Valley "the Land of Little Rain." The bed of Owens Lake, now a predominantly dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles City Council
The Los Angeles City Council is the legislative body of the Los Angeles, City of Los Angeles in California. The council is composed of 15 members elected from single-member districts for four-year terms. The President of the Los Angeles City Council, president of the council and the president pro tempore are chosen by the council at the first regular meeting of the term (after June 30 in odd-numbered years until 2017 and the second Monday of December in even-numbered years beginning in 2020). An assistant president pro tempore is appointed by the President. As of 2020, council members receive an annual salary of $207,000 per year, which is among the highest city council salary in the nation. Regular council meetings are held in the Los Angeles City Hall, City Hall on Tuesdays, Wednesdays and Fridays at 10 am except on holidays or if decided by special resolution. Current members Officers: *President of the Los Angeles City Council, President of the Council: Paul Krekorian (since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
