California Central Valley
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- For the Central Valley of Costa Rica, see Valle Central.
The California Central Valley is a large, flat valley that dominates the central portion of the U.S. state of California. It is home to many of California's most productive agricultural efforts. The California Central Valley stretches nearly 400 miles (600 km) north to south, its northern half referred to as the Sacramento Valley and its southern half as the San Joaquin Valley. The two halves are joined by the shared delta of the Sacramento and San Joaquin Rivers, a large expanse of interconnected canals, streambeds, sloughs, marshes and peat islands.
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[edit] Boundaries and population
Bounded by the Cascade Range to the north, the Sierra Nevada to the east, the Tehachapi Mountains to the south, and the Coast Ranges and San Francisco Bay to the west, the valley is a vast agricultural region drained by the Sacramento and San Joaquin rivers.
These counties are commonly associated with the Central Valley:
- North San Joaquin (San Joaquin, Stanislaus, Merced)
About 5.7 million people live in the Central Valley today.
The six largest cities, in order of population, are Fresno, Sacramento, Bakersfield, Stockton, Modesto and Visalia.
[edit] Geology
The flatness of the valley floor contrasts with the rugged hills or gentle mountains that are typical of most of California's terrain. The valley is thought to have originated below sea level as an offshore area depressed by subduction of the Farallon Plate into a trench further offshore.
It was later enclosed by the uplift of the Coast Ranges, with its original outlet into Monterey Bay. Faulting moved the Coast Ranges, and a new outlet developed near what is now San Francisco Bay. Over the millennia, the valley was filled by the sediments of these same ranges, as well as the rising Sierra Nevada to the east; that filling eventually created an extraordinary flatness just barely above sea level; at one time the annual snow melt turned the entire valley into an inland lake.
The one notable exception to the flat valley floor is Sutter Buttes, the remnants of an extinct volcano just to the northwest of Yuba City which is 44 miles north of Sacramento.
[edit] Climate
The Central Valley is hot and dry during the summer and cool and damp in winter, when frequent ground fog known regionally as "tule fog" can be impenetrable. Summer temperatures reach into the mid to upper 90s F (30s C), and occasional heat waves might bring temperatures well over 100 F (38 C), with some locations topping out at around 120 F (49 C). Winter and spring comprise the rainy season — although during the late summer, southeasterly winds aloft can bring thunderstorms of tropical origin, mainly in the southern half of the San Joaquin Valley. The northern half of the Central Valley (the Sacramento Valley) has more precipitation than the dryer southern San Joaquin Valley.
[edit] Rivers and delta
The Sacramento and San Joaquin Rivers flow through the northern and southern halves of the valley, respectively. The two rivers join to form the San Joaquin-Sacramento River Delta, an unusual inverted river delta, behind the Carquinez Strait. Major tributaries of these two rivers include:
[edit] Sacramento Valley
[edit] San Joaquin Valley
- Cosumnes River
- Mokelumne River
- Stanislaus River
- Tuolumne River
- Merced River
- Chowchilla River
- Fresno River
- San Joaquin River
- Kings River
- Kern River
[edit] Major cities
Major cities in the Central Valley include Fresno (464,727), Sacramento (450,000), Bakersfield (312,000) Stockton, ( 289,800) Modesto (206,300), and Visalia (110,000).
[edit] Culture and politics
Culturally and politically, the Central Valley is more conservative than the densely populated urban regions of California such as the San Francisco Bay Area and Los Angeles. Some cities, such as the college towns of Chico and Davis (home to the California State University, Chico and the University of California, Davis, respectively), are more liberal than the rest of the Valley, but their surrounding counties are typically conservative. The city of Sacramento is also more liberal than the Valley average, but its surrounding suburbs, particularly in Placer and El Dorado Counties, are conservative.
The Central Valley should not be confused with "the Valley" that is home to Valley girls, the San Fernando Valley in the Los Angeles region.
[edit] Agriculture
The Central Valley is one of the most productive agricultural regions in the world. It is commonly referred to as the "fruit basket of the world." Virtually all non-tropical crops are grown here. Early farming was concentrated close to the Sacramento-San Joaquin Delta, where the water table was high year round and water transport more readily available, but subsequent irrigation projects have brought many more parts of the valley into productive use. For example, the Central Valley Project was formed in 1935 to redistribute and store water for agricultural and municipal purposes with dams and canals.
It was in the Central Valley, especially in and around Delano, that farm labor leader Cesar Chavez organized Mexican American grape pickers into a union in the 1960s, the National Farmworkers Association (NFWA), in order to improve their working conditions.
[edit] Social issues
Since the 1980s, Bakersfield, Fresno, Visalia, Tracy and Modesto have exploded in both size and population, as housing values along the coast increased. Many people from the San Francisco Bay Area have moved out to more rural areas in search of more affordable housing, congesting roads between their Valley homes and their Bay Area jobs.
These cities (along with Sacramento) have been confronted by big-city problems, including violent crime, drug trafficking, organized crime, traffic congestion, and air pollution. The San Joaquin Valley now has the worst air quality in California, along with the highest asthma rates, and like the more populous areas, its cities are subject to stringent anti-pollution laws.
[edit] Highways and Infrastructure
Interstate 5 and California State Route 99 run, roughly parallel, north-south through the valley. Interstate 80 crosses it east-west from Nevada to San Francisco. In addition to highways, the California Aqueduct follows I-5 from Tracy on southwards to Southern California across the Transverse Ranges. PG&E's and Western Area Power Administration's system of three 500 kV wires (Path 15 and Path 66) run through the valley. Path 26 also runs in the southernmost part of the San Joaquin Valley.
[edit] External links
- Great Valley Center
- Students for the Central Valley
- Valley Vision
- Photos of the Central Valley - Terra Galleria
de:Kalifornisches Längstal fr:Vallée Centrale de Californie ja:カリフォルニアセントラルヴァレー
