An inverted river delta is a river delta in which the narrow end of the delta emerges on the seafront and the wide end is located further inland, so that with respect to the seafront, the locations of both ends of the delta are inverted.
An inverted river delta is a river delta in which the narrow end of the delta emerges on the seafront and the wide end is located further inland, so that with respect to the seafront, the locations of both ends of the delta are inverted.
River deltas typically form on flat, coastal floodplains: the narrow end located at the point where a river fans out and deposits sediment in a region extending outward into the body of water which the river empties. In the case of an inverted delta, the delta is located at the waterway's exit from a large, flat valley, yet still inside the valley. The sediment is dropped within the valley and the clear water then exits into a bay or the ocean, so the apex of the delta is at this exit, a configuration said to be inverted from that usually seen. Inverted deltas typically do not last long in geological terms, since they tend to fill up with sediments rather quickly and eventually become normal deltas[ citation needed ].
A classic example of an inverted river delta is the Sacramento-San Joaquin River Delta, which lies at the confluence of the Sacramento and San Joaquin rivers in California. [1] The water from the rivers that drain the entire, large California Central Valley exit through the Carquinez Strait, a narrow gap in the Coast Range. An inverted river delta exists behind this strait.
Another example is the delta of the Tagus river in Portugal, although due to sedimentation this delta is now only very partially inverted, with the valley now mostly filled with sediment. It is still about 15 km wide and 25 km long, compared with the 2 km wide exit into the sea, and forms a large lagoon with large and very shallow sand banks which go uncovered during low tides. The delta used to be even bigger thousands of years ago.
San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the cities of San Francisco, San Jose, and Oakland.
A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a very long period. Some valleys are formed through erosion by glacial ice. These glaciers may remain present in valleys in high mountains or polar areas.
The Sacramento River is the principal river of Northern California in the United States and is the largest river in California. Rising in the Klamath Mountains, the river flows south for 400 miles (640 km) before reaching the Sacramento–San Joaquin River Delta and San Francisco Bay. The river drains about 26,500 square miles (69,000 km2) in 19 California counties, mostly within the fertile agricultural region bounded by the Coast Ranges and Sierra Nevada known as the Sacramento Valley, but also extending as far as the volcanic plateaus of Northeastern California. Historically, its watershed has reached as far north as south-central Oregon where the now, primarily, endorheic (closed) Goose Lake rarely experiences southerly outflow into the Pit River, the most northerly tributary of the Sacramento.
The Tagus is the longest river in the Iberian Peninsula. The river rises in the Montes Universales near Teruel, in mid-eastern Spain, flows 1,007 km (626 mi), generally westward, and empties into the Atlantic Ocean in Lisbon.
The Central Valley is a broad, elongated, flat valley that dominates the interior of California. It is 40–60 mi (60–100 km) wide and runs approximately 450 mi (720 km) from north-northwest to south-southeast, inland from and parallel to the Pacific coast of the state. It covers approximately 18,000 sq mi (47,000 km2), about 11% of California's land area. The valley is bounded by the Coast Ranges to the west and the Sierra Nevada to the east.
The San Joaquin River is the longest river of Central California. The 366-mile (589 km) long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suisun Bay, San Francisco Bay, and the Pacific Ocean. An important source of irrigation water as well as a wildlife corridor, the San Joaquin is among the most heavily dammed and diverted of California's rivers.
The San Joaquin Valley is the southern half of California's Central Valley. Famed as a major breadbasket, the San Joaquin Valley is an important source of food, producing a significant part of California's agricultural output.
The Sacramento Valley is the area of the Central Valley of the U.S. state of California that lies north of the Sacramento–San Joaquin River Delta and is drained by the Sacramento River. It encompasses all or parts of ten Northern California counties. Although many areas of the Sacramento Valley are rural, it contains several urban areas, including the state capital, Sacramento. Since 2010, statewide droughts in California have further strained both the Sacramento Valley's and the Sacramento metropolitan region's water security.
The Governor Edmund G. Brown California Aqueduct is a system of canals, tunnels, and pipelines that conveys water collected from the Sierra Nevada Mountains and valleys of Northern and Central California to Southern California. Named after California Governor Edmund Gerald "Pat" Brown Sr., the over 400-mile (640 km) aqueduct is the principal feature of the California State Water Project.
San Pablo Bay is a tidal estuary that forms the northern extension of San Francisco Bay in the East Bay and North Bay regions of the San Francisco Bay Area in northern California.
The Carquinez Strait is a narrow tidal strait located in the Bay Area of Northern California, United States. It is part of the tidal estuary of the Sacramento and the San Joaquin rivers as they drain into the San Francisco Bay. The strait is eight miles (13 km) long and connects Suisun Bay, which receives the waters of the combined rivers, with San Pablo Bay, a northern extension of the San Francisco Bay.
The Sacramento–San Joaquin River Delta, or California Delta, is an expansive inland river delta and estuary in Northern California. The Delta is formed at the western edge of the Central Valley by the confluence of the Sacramento and San Joaquin rivers and lies just east of where the rivers enter Suisun Bay, which flows into San Francisco Bay, then the Pacific Ocean via San Pablo Bay. The Delta is recognized for protection by the California Bays and Estuaries Policy. Sacramento–San Joaquin Delta was designated a National Heritage Area on March 12, 2019. The city of Stockton is located on the San Joaquin River at the eastern edge of the delta. The total area of the Delta, including both land and water, is about 1,100 square miles (2,800 km2). Its population is around 500,000.
The California Central Valley grasslands is a temperate grasslands, savannas, and shrublands ecoregion in California's Central Valley. It a diverse ecoregion containing areas of desert grassland, prairie, savanna, riparian forest, marsh, several types of seasonal vernal pools, and large lakes such as now-dry Tulare Lake, Buena Vista Lake, and Kern Lake.
The Cosumnes River is a river in northern California in the United States. It rises on the western slope of the Sierra Nevada and flows approximately 52.5 miles (84.5 km) into the Central Valley, emptying into the Mokelumne River in the Sacramento-San Joaquin Delta.
The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest public water and power utilities in the world, providing drinking water for more than 27 million people and generating an average of 6,500 GWh of hydroelectricity annually. However, as it is the largest single consumer of power in the state itself, it has a net usage of 5,100 GWh.
Clifton Court Forebay is a reservoir in the San Joaquin River Delta region of eastern Contra Costa County, California, 17 mi (27 km) southwest of Stockton. The estuary region the forebay is located in is only 1m to 3m above mean sea level.
The San Francisco Estuary together with the Sacramento–San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.
Alhambra Creek is a stream in Contra Costa County, in the East Bay region of the San Francisco Bay Area in northern California.
The Great Valley Sequence of California is a 40,000-foot (12 km)-thick group of related geologic formations that are Late Jurassic through Cretaceous in age on the geologic time scale. These sedimentary rocks were deposited during the late Mesozoic Era in an ancient seaway that corresponds roughly to the outline of the modern Great Valley of California.
The geology of California is highly complex, with numerous mountain ranges, substantial faulting and tectonic activity, rich natural resources and a history of both ancient and comparatively recent intense geological activity. The area formed as a series of small island arcs, deep-ocean sediments and mafic oceanic crust accreted to the western edge of North America, producing a series of deep basins and high mountain ranges.