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Physiography of Long Beach
Long Beach is situated on a slightly elevated terrace amidst the coastal plain of the Los Angeles basin. The Inglewood-Newport fault system stretches in a northwest-southeast direction defining the hills and geologic features of Long Beach.
The terrace on which Long Beach sits creates the eastern ridge of a valley in which the Los Angeles River flows. The ridge is at some locations very subtle, in other places dramatic, creating vast overlooks into the valley below. Most notable to Long Beach is the City of Signal Hill, which rises to a height of 360 feet and the Palos Verdes Hills, located west of Long Beach, rise to 1480 feet above sea level.
As the region’s rivers became silted in with sand and gravel, they sunk down into the earth and became subsurface aquifers. Three major aquifers lie beneath Long Beach; the 400-foot Gravel, the 200-foot Sand and the Gaspur Zone, which typically contain brine water that improves to potable status further inland. The shallow depths of groundwater along the river preclude the use of recharge basins near the river’s mouth. Together these three aquifers can store approximately thirty million acre-feet of water, which until the 1920s was fresh water. However, industrial pollution and salt-water intrusion contaminated these subsurfaces reservoirs which now, cannot be used for potable water.
The climate of Southern California is classified as Mediterranean, which is characterized by hot summer droughts followed by winter rains.
Along the coastal plain, the high-pressure belts of the subtropics shift northwards in the summer creating average highs of 81.4 degrees Fahrenheit and lows of 62.9 degrees. In the mild winter months, when the high-pressure belt retreats towards the equator, the average highs are 67.3 degrees Fahrenheit with lows of 46.0 degrees. The winter rains are variable but typically bring about 12 inches. Rainfall in the mountains surrounding the coastal plain accounts for 75% of the runoff for the entire region. The mountains also trap ocean breezes, keeping the summer temperatures moderate, as well as trap winter storms, creating the sometimes catastrophic flood events.
Urban heat islands effect large portions of the westside of Long Beach, contributing to higher microclimate temperatures in and around industrial zones or other areas with large paved surfaces and sparse tree canopy. The map shows downtown Long Beach and much of Willmore City engulfed by the heat island effect generated largely from the ports, light industrial zones, and lack of street trees. The map also denotes other pollution sources affecting air quality in the westside of Long Beach. For more information on the urban heat island effect, see Appendix C.
More to come...
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More to come...
@2003 "Long Beach RiverLink: Connecting city to river...envisioning possibilities" is a trademark of the San Pedro Bay Estuary Project.
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