Sinking of California's San Joaquin Valley Seen from Space

[Judi Lynn]

Sinking of California's San Joaquin Valley Seen from Space
By Stephanie Pappas, Live Science Contributor | March 7, 2017 07:15am ET




A map showing the subsidence of the San Joaquin Valley in California. The more yellow the color, the larger the sinking of the land. Some areas around Corcoran have subsided by nearly 2 feet (60 centimeters) in little more than a year.
Credit: NASA Earth Observatory


A new map made with satellite radar data shows the sinking of California's San Joaquin Valley in deceptively tranquil colors.

The map, released by NASA's Earth Observatory, shows land subsidence between May 2015 and September 2016. The valley is sinking because of the pumping of groundwater from underground reservoirs, a problem exacerbated by the state's recent extreme drought.

NASA's Jet Propulsion Laboratory (JPL) has been tasked by the California Department of Water Resources (DWR) with tracking the subsidence, according to the Earth Observatory. The newly released image uses data from the European Space Agency's Sentinel-1A satellite. [It's Raining Spiders! The Weirdest Effects of California's Drought]

Areas with more yellow are subsiding the greatest amount. Near Corcoran, a bowl-like depression sunk about 22 inches (56 centimeters) over little more than a year, according to the Jet Propulsion Laboratory report. This area, which extends about 60 miles (97 kilometers) was already known to be sinking, as was a second subsidence hotspot near El Nido, where the satellite observations showed about 16 inches (40 cm) of subsidence over a bowl with a diameter of 25 miles (40 km).

More:
http://www.livescience.com/58141-san-joaquin-valley-sinking-space-image.html?utm_source=notification

[procon]

1. They're pumping out more ground water than the natural system can replace.

Groundwater levels are dependent on recharge from snow packs, but we've had this long drought in California's and the over pumping by agribiz means the subsidence will increase. The problem shows up the path of streams, canals, and drainage areas as slopes change. There's damage to bridges, roads, railroads, sewers, and buried pipelines, building foundations are also at risk .

In my own rural community, our aquifer is being sucked dry by corporate ag ventures, many based in other countries, and the subsidence, although small, has caused one well failure as thr well casing collapsed.

[AuntPatsy]

2. Ultimately there will be a reckoning....