San Gabriel Canyon
The San Gabriel River is a mostly urban waterway flowing southward through Los Angeles and Orange Counties, California in the United States. It is the central of three major rivers draining the Greater Los Angeles Area, the others being the Los Angeles River and Santa Ana River. The river's watershed stretches from the rugged San Gabriel Mountains to the heavily developed San Gabriel Valley and a significant part of the Los Angeles coastal plain, emptying into the Pacific Ocean between the cities of Long Beach and Seal Beach. The San Gabriel once ran across a vast alluvial flood plain, its channels shifting with winter floods and forming extensive wetlands along its perennial course, a relatively scarce source of fresh water in this arid region. The Tongva people and their ancestors have inhabited the San Gabriel River basin for thousands of years, relying on the abundant fish and game in riparian habitats. The river is named for the nearby Mission San Gabriel Arcángel, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Los Alamitos, California
Los Alamitos () is a city in Orange County, California. The city was incorporated in March 1960. The population was 11,780 at the 2020 census, up from 11,449 at the 2010 census. The adjacent unincorporated community of Rossmoor uses the same 90720 ZIP code in its mailing address, but is not part of the city. The Los Alamitos Race Course is named for the city, but lies in the neighboring city of Cypress. The USA Water Polo National Aquatic Center is located on the Joint Forces Training Base - Los Alamitos. History The history of the area during the Californio period and after U.S. annexation is detailed in the article on Rancho Los Alamitos. The town of Los Alamitos was established in 1896 by Lewellyn Bixby to support the new sugar beet factory in town built by the extremely wealthy Clark Brothers. William Andrews Clark, a future Senator from Montana, had built his fortune in mining, banking and logging in that state. His younger brother, J. Ross Clark, managed their op ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Urban Stream
An urban stream is a formerly natural waterway that flows through a heavily populated area. Urban streams are often polluted by urban runoff and combined sewer outflows. Water scarcity makes flow management in the rehabilitation of urban streams problematic. Description Governments may alter the flow or course of an urban stream to prevent localized flooding by river engineering: lining stream beds with concrete or other hardscape materials, diverting the stream into culverts and storm sewers, or other means. Some urban streams, such as the subterranean rivers of London, run completely underground. These modifications have often reduced habitat for fish and other species, caused downstream flooding due to alterations of flood plains, and worsened water quality. Restoration efforts Some communities have begun stream restoration projects in an attempt to correct the problems caused by alteration, using techniques such as daylighting and fixing stream bank erosion caused by he ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Riprap
Riprap (in North American English), also known as rip rap, rip-rap, shot rock, rock armour (in British English) or rubble, is human-placed rock or other material used to protect shoreline structures against scour and water, wave, or ice erosion. Ripraps are used to armor shorelines, streambeds, bridge abutments, foundational infrastructure supports and other shoreline structures against erosion. Common rock types used include granite and modular concrete blocks. Rubble from building and paving demolition is sometimes used, as well as specifically designed structures called tetrapods. Riprap is also used underwater to cap immersed tubes sunken on the seabed to be joined into an undersea tunnel. Environmental effects Sediment effects Ripraps cause morphological changes in the riverbeds they surround. One such change is the reduction of sediment settlement in the river channel, which can lead to scouring of the river bed as well as coarser sediment particles. This can be com ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Channelization (river)
River engineering is a discipline of civil engineering which studies human intervention in the course, characteristics, or flow of a river with the intention of producing some defined benefit. People have intervened in the natural course and behaviour of rivers since before recorded history—to manage the water resources, to protect against flooding, or to make passage along or across rivers easier. Since the Yuan Dynasty and Ancient Roman times, rivers have been used as a source of hydropower. From the late 20th century, the practice of river engineering has responded to environmental concerns broader than immediate human benefit. Some river engineering projects have focused exclusively on the restoration or protection of natural characteristics and habitats. Hydromodification encompasses the systematic response to alterations to riverine and non-riverine water bodies such as coastal waters (estuaries and bays) and lakes. The U.S. Environmental Protection Agency (EPA) has de ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Debris Flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally have bulk densities comparable to those of rock avalanches and other types of landslides (roughly 2000 kilograms per cubic meter), but owing to widespread sediment liquefaction caused by high pore-fluid pressures, they can flow almost as fluidly as water. Debris flows descending steep channels commonly attain speeds that surpass 10 m/s (36 km/h), although some large flows can reach speeds that are much greater. Debris flows with volumes ranging up to about 100,000 cubic meters occur frequently in mountainous regions worldwide. The largest prehistoric flows have had volumes exceeding 1 billion cubic meters (i.e., 1 cubic kilometer). As a result of their high sediment concentrations and mobility, debris flows can be very de ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Los Angeles Flood Of 1938
The Los Angeles flood of 1938 was one of the largest floods in the history of Los Angeles, Orange, and Riverside Counties in southern California. The flood was caused by two Pacific storms that swept across the Los Angeles Basin in February-March 1938 and generated almost one year's worth of precipitation in just a few days. Between 113–115 people were killed by the flooding. The Los Angeles, San Gabriel, and Santa Ana Rivers burst their banks, inundating much of the coastal plain, the San Fernando and San Gabriel Valleys, and the Inland Empire. Flood control structures spared parts of Los Angeles County from destruction, while Orange and Riverside Counties experienced more damage. The flood of 1938 is considered a 50-year flood. It caused $78 million of damage ($ in dollars), making it one of the costliest natural disasters in Los Angeles' history. In response to the floods, the U.S. Army Corps of Engineers and other agencies began to channelize local streams in concre ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Spanish Missions In California
The Spanish missions in California ( es, Misiones españolas en California) comprise a series of 21 religious outposts or missions established between 1769 and 1833 in what is now the U.S. state of California. Founded by Catholic priests of the Franciscan order to evangelize the Native Americans, the missions led to the creation of the New Spain province of Alta California and were part of the expansion of the Spanish Empire into the most northern and western parts of Spanish North America. Following long-term secular and religious policy of Spain in Spanish America, the missionaries forced the native Californians to live in settlements called reductions, disrupting their traditional way of life. The missionaries introduced European fruits, vegetables, cattle, horses, ranching, and technology. Immense reductions in the population of Indigenous peoples of California occurred through the introduction of European diseases, which quickly spread as native people were f ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mission San Gabriel Arcángel
Mission San Gabriel Arcángel ( es, Misión de San Gabriel Arcángel) is a Californian mission and historic landmark in San Gabriel, California. It was founded by Spaniards of the Franciscan order on "The Feast of the Birth of Mary," September 8, 1771, as the fourth of what would become twenty-one Spanish missions in California. San Gabriel Arcángel was named after the Archangel Gabriel and often referred to as the "Godmother of the Pueblo of Los Angeles." The mission was built and run using what has been described as slave labor from nearby Tongva villages, such as Yaanga and was built on the site of the village of Toviscanga. When the nearby Pueblo de los Ángeles was built in 1781, the mission competed with the emerging pueblo for control of Indigenous labor. The mission was designed by Antonio Cruzado, who gave the building its capped buttresses and the tall narrow windows, which are unique among the missions of the California chain. A large stone cross stands in the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tongva People
The Tongva ( ) are an Indigenous people of California from the Los Angeles Basin and the Southern Channel Islands, an area covering approximately . Some descendants of the people prefer Kizh as an endonym that, they argue, is more historically accurate. In the precolonial era, the people lived in as many as 100 villages and primarily identified by their village rather than by a pan-tribal name. During colonization, the Spanish referred to these people as Gabrieleño and Fernandeño, names derived from the Spanish missions built on their land: Mission San Gabriel Arcángel and Mission San Fernando Rey de España. ''Tongva'' is the most widely circulated endonym among the people, used by Narcisa Higuera in 1905 to refer to inhabitants in the vicinity of Mission San Gabriel. Along with the neighboring Chumash, the Tongva were the most influential people at the time of European encounter. They had developed an extensive trade network through '' te'aats'' (plank-built boats). ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Alluvium
Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is typically geologically young and is not consolidated into solid rock. Sediments deposited underwater, in seas, estuaries, lakes, or ponds, are not described as alluvium. Floodplain alluvium can be highly fertile, and supported some of the earliest human civilizations. Definitions The present consensus is that "alluvium" refers to loose sediments of all types deposited by running water in floodplains or in alluvial fans or related landforms. However, the meaning of the term has varied considerably since it was first defined in the French dictionary of Antoine Furetière, posthumously published in 1690. Drawing upon concepts from Roman law, Furetière defined ''alluvio ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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San Gabriel Valley
The San Gabriel Valley ( es, Valle de San Gabriel) is one of the principal valleys of Southern California, lying immediately to the east of the eastern city limits of the city of Los Angeles, and occupying the vast majority of the eastern part of Los Angeles County, California. Surrounding features include: * San Gabriel Mountains on the north, * San Rafael Hills to the west, with Los Angeles Basin beyond, * Crescenta Valley to the northwest, * Puente Hills to the south, with the coastal plain of Orange County beyond, * Chino Hills and San Jose Hills to the east, with the Pomona Valley and Inland Empire beyond. * The city limits of Los Angeles bordering its western edge. The San Gabriel valley derives its name from the San Gabriel River that flows southward through the center of the valley, which itself was named for the Spanish Mission San Gabriel Arcángel originally built in the Whittier Narrows in 1771. At one time predominantly agricultural, the San Gabriel Vall ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Drainage Basin
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the '' drainage divide'', made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern. Other terms for a drainage basin are catchment area, catchment basin, drainage area, river basin, water basin, and impluvium. In North America, they are commonly called a watershed, though in other English-speaking places, "watershed" is used only in its original sense, that of a drainage divide. In a closed drainage basin, or endorheic basin, the water converges to a single point inside the basin, known as a sink, which may be a permanent lake, a dry lake, or a point where surface water is lost underground. Drainage basins are simi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |