Editing Central Valley (California) (section)

=== Landslides ===
There is a very strong positive correlation between rainfall and slow-moving [[landslide]]s in Northern California, especially in the Central Valley region. Changes in climate and precipitation levels have shown that consistent average rainfall has increased the number and intensity of landslides within the past 5–6 years. This information was shown in a study that focused on the behavior of these slow-moving landslides and how their nature changed with years of extreme average rainfall versus minimal average rainfall. In 2016, the average annual precipitation levels were lower because of a drought that was coming to an end at that time. The minimal rainfall in that year showed that 119 landslides had been moving. Comparatively, in 2017, there were very extreme levels of precipitation in the Central Valley, which cause 312 landslides to move that year.<ref>{{Cite journal|last1=Handwerger|first1=Alexander L.|last2=Fielding|first2=Eric J.|last3=Huang|first3=Mong-Han|last4=Bennett|first4=Georgina L.|last5=Liang|first5=Cunren|last6=Schulz|first6=William H.|date=2019|title=Widespread Initiation, Reactivation, and Acceleration of Landslides in the Northern California Coast Ranges due to Extreme Rainfall|url=https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JF005035|journal=Journal of Geophysical Research: Earth Surface|language=en|volume=124|issue=7|pages=1782–1797|doi=10.1029/2019JF005035|bibcode=2019JGRF..124.1782H|hdl=10871/39639 |s2cid=197567643|issn=2169-9011|hdl-access=free}}</ref> Slow-moving landslides are impacted even if the intensity of the rainfall is not as severe.

Consistent, moderately intense rainfall increases the saturation of water in the ground. This over-saturation is what causes the movement of a slow-moving landslide, rather than the more quick-moving and rigorous landslides that also occur in this region of California. Quick-moving landslides are caused by very intense rain, or sometimes earthquakes, that make a greater difference in the land in a shorter amount of time. According to a survey paper written in 1988 about a storm that occurred in 1982 in the Central Valley region, rainstorms that can cause that type of landslide to happen about every 5 years. Landslides to higher degrees, such as the ones that happened due to the 1982 storm, only occur every 20 to 100+ years. This intense storm in the San Francisco Bay area caused a lot of damage as a result of moving debris and landslides. They caused damage to the land and put people living in these areas that are susceptible to these disasters in great harm. The aftermath of this storm involved millions of dollars in retributions to restore the land and surrounding areas. It also led people to make greater efforts into planning around the danger of these landslides, as in how to manipulate the land to accommodate the consequences.