South Lahontan

Postfire Sediment Mobilization and its Downstream Implications Across California, 1984–2021

American Geophysical Union (AGU) | August 27th, 2024

PPIC Statewide Survey: Californians and the Environment

Public Policy Institute of California (PPIC) | July 28th, 2022

With California facing a severe drought and wildfire season, public awareness has risen of the impact of climate change as well as state policies to reduce greenhouse gas

With California facing a severe drought and wildfire season, public awareness has risen of the impact of climate change as well as state policies to reduce greenhouse gas emissions. A sharp increase in petroleum prices has led to discussions about expanding oil production and renewable energy sources. These are among the key findings of a statewide survey on environmental issues conducted by the Public Policy Institute of California from July 8 to 15, 2022.

PPIC Statewide Survey: Californians and the Environment

Public Policy Institute of California (PPIC) | August 8th, 2024

Californians have been facing a record heat wave and wildfires across the state this summer. The state’s multibillion-dollar budget deficit prompted spending cuts for

Californians have been facing a record heat wave and wildfires across the state this summer. The state’s multibillion-dollar budget deficit prompted spending cuts for climate and energy programs. In response, the legislature approved a $10 billion state bond for the November ballot that asks voters to approve more funding for drought, floods, wildfires, coastal resilience, and extreme heat mitigation. The deep partisan divide on climate and energy policies surfaced in the presidential debate on June 27. These are the key findings of the Californians and the Environment survey on local, state, and national issues and coastal and inland topics that was conducted June 24–July 2, 2024.

Precipitation History of the Mojave Desert Region, 1893–2001

U.S. Geological Survey (USGS) | July 1st, 2004

The Mojave Desert region covers 152,000 square km of the Southwestern United States. Recent studies by U.S. Geological Survey (USGS) and other scientists suggest

The Mojave Desert region covers 152,000 square km of the Southwestern United States. Recent studies by U.S. Geological Survey (USGS) and other scientists suggest that the region may become drier for the next 2 to 3 decades, in a pattern similar to mid-20th century dry conditions. Because the region’s population has increased rapidly since the mid-1950s, a repeat of such a dry episode could have severe consequences not only for residents but also for the desert’s diverse and fragile ecosystems.

Precipitation regime classification for the Mojave Desert: Implications for fire occurrence

Journal of Arid Environments (Elsevier) | September 29th, 2015

Long periods of drought or above-average precipitation affect Mojave Desert vegetation condition, biomass and susceptibility to fire. Changes in the seasonality of preci

Long periods of drought or above-average precipitation affect Mojave Desert vegetation condition, biomass and susceptibility to fire. Changes in the seasonality of precipitation alter the likelihood of lightning, a key ignition source for fires. The objectives of this study were to characterize the relationship between recent, historic, and future precipitation patterns and fire. Classifying monthly precipitation data from 1971 to 2010 reveals four precipitation regimes: low winter/low summer, moderate winter/moderate summer, high winter/low summer and high winter/high summer. Two regimes with summer monsoonal precipitation covered only 40% of the Mojave Desert ecoregion but contain 88% of the area burned and 95% of the repeat burn area. Classifying historic precipitation for early-century (wet) and mid-century (drought) periods reveals distinct shifts in regime boundaries. Early-century results are similar to current, while the mid-century results show a sizeable reduction in area of regimes with a strong monsoonal component. Such a shift would suggest that fires during the mid-century period would be minimal and anecdotal records confirm this. Predicted precipitation patterns from downscaled global climate models indicate numerous epochs of high winter precipitation, inferring higher fire potential for many multi-decade periods during the next century.

Predicting California Water-Year Types Using Seasonal Climate Forecasts

American Meteorological Society (AMS) | August 1st, 2025

Preliminary Evaluation of the Hydrogeologic System in Owens Valley, California

U.S. Geological Survey (USGS) | January 8th, 1988

Owens Valley is a major source of water for southern California and presently (1986) provides more than 60 percent of the supply for Los Angeles. Since 1970, ground-water

Owens Valley is a major source of water for southern California and presently (1986) provides more than 60 percent of the supply for Los Angeles. Since 1970, ground-water withdrawal from Owens Valley has increased, and a decline in the health of vegetation has been reported. In 1982, a cooperative project to study the hydrogeology and plant ecology of Owens Valley was begun by Inyo County, the Los Angeles Department of Water and Power, and the U.S. Geological Survey. As part of this project, the available data and present hydrologic concepts of Owens Valley were evaluated by using a ground-waterflow model. Results of this preliminary evaluation are being used to guide data collection and the development of more sophisticated hydrologic models.

Preliminary hydrogeologic assessment near the boundary of the Antelope Valley and El Mirage Valley groundwater basins, California

U.S. Geological Survey (USGS) | July 19th, 2017

Priorities for California's Water: Responding to the Changing Climate

Public Policy Institute of California (PPIC) | November 18th, 2021

Water is central to how California adapts to a changing climate. To those of us steeped in the complexities of managing the state’s water resources, the current fast-mo

Water is central to how California adapts to a changing climate. To those of us steeped in the complexities of managing the state’s water resources, the current fast-moving drought—coming on the heels of the record-breaking 2012–16 drought—is a stark reminder that we must accelerate preparation for the disruptive changes underway. Californians have taken steps to address major threats to our water resources. But a recent IPCC report underscored that the climate is changing faster than anticipated, and that many of these changes are already locked in. Rising temperatures are making our winters shorter and our droughts more intense, outpacing our ability to manage water supplies and the natural environment. We need to act with urgency to adapt to these changes. And we need to rethink how we store water. This brief examines how the current drought and a changing climate are affecting California’s ability to manage water and lays out priority actions to address major challenges—including some urgent short-term actions should the drought continue into next year.

Priorities for California’s Water

Public Policy Institute of California (PPIC) | November 14th, 2022

This report considers the state of water in California: What changes are we seeing now, and what should we expect in the near future? Then it examines how these climate s

This report considers the state of water in California: What changes are we seeing now, and what should we expect in the near future? Then it examines how these climate shifts will impact urban and rural communities, agriculture, and the environment. Finally, it explores wet-year strategies that will help Californians get through the dry years.