Shop – California Water Library

Page

Showing
1-11 of 183

Per Page

Sort By

21st century California drought risk linked to model fidelity of the El Niño teleconnection

Nature Portfolio (Springer Nature) | September 3rd, 2018

Summary

Greenhouse gas-induced climate change is expected to lead to negative hydrological impacts for southwestern North America, including California (CA). This includes a decr

Greenhouse gas-induced climate change is expected to lead to negative hydrological impacts for southwestern North America, including California (CA). This includes a decrease in the amount and frequency of precipitation, reductions in Sierra snow pack, and an increase in evapotranspiration, all of which imply a decline in surface water availability, and an increase in drought and stress on water resources. However, a recent study showed the importance of tropical Pacific sea surface temperature (SST) warming and an El Niño Southern Oscillation (ENSO)-like teleconnection in driving an increase in CA precipitation through the 21st century, particularly during winter (DJF). Here, we extend this prior work and show wetter (drier) CA conditions, based on several drought metrics, are associated with an El Niño (La Niña)-like SST pattern. Models that better simulate the observed ENSO-CA precipitation teleconnection also better simulate the ENSO-CA drought relationships, and yield negligible change in the risk of 21st century CA drought, primarily due to wetting during winter. Seasonally, however, CA drought risk is projected to increase during the non-winter months, particularly in the models that poorly simulate the observed teleconnection. Thus, future projections of CA drought are dependent on model fidelity of the El Niño teleconnection. As opposed to focusing on adapting to less water, models that better simulate the teleconnection imply adaptation measures focused on smoothing seasonal differences for affected agricultural, terrestrial, and aquatic systems, as well as effectively capturing enhanced winter runoff.

View Document Download Now Email

A 440-Year Reconstruction of Heavy Precipitation in California from Blue Oak Tree Rings

American Meteorological Society (AMS) | January 10th, 2023

Summary

The variability of water year precipitation and selected blue oak tree-ring chronologies in California are both dominated by heavy precipitation delivered during just a f

The variability of water year precipitation and selected blue oak tree-ring chronologies in California are both dominated by heavy precipitation delivered during just a few days each year. These heavy precipitation events can spell the difference between surplus or deficit water supply, and elevated flood risk. Some blue oak chronologies are highly correlated with water year precipitation (r = 0.84) but are equally well correlated (r = 0.82) with heavy precipitation totals ≥25.4 mm (one inch, ≈95th percentile of daily totals, 1949-2004). The blue oak correlation with non-heavy daily totals is much weaker (

View Document Download Now Email

A Measure of Snow: A Report Based on Case Studies of The Snow Survey and Water Supply Forecasting Program

U.S. Department of Agriculture (USDA) | November 1st, 2008

Summary

Snow depth and snow water content data have been collected and disseminated throughout the Western United States for over 100 years. Early snow survey and water s

Snow depth and snow water content data have been collected and disseminated throughout the Western United States for over 100 years. Early snow survey and water supply data were gathered through the efforts of university scientists, beginning with the work of Dr. James E. Church. In 1935, the Soil Conservation Service (SCS), now the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS), established a formal cooperative Snow Survey and Water Supply Forecasting (SS-WSF) Program. The Agency was charged with responsibility for “conducting snow survey and water supply forecasts and the forecasting of irrigation water supplies.” The new Program would also develop consistent methods for measuring snow and reliable models for accurate water supply forecasting. Administered by NRCS, the SS-WSF Program has grown into a network of more than 1,200 manually-measured snow courses and over 750 automated Snowpack Telemetry (SNOTEL) weather stations in 13 Western States, including Alaska. (See map on page 4.) The SS-WSF Program provides manual snow course data collected by NRCS conservation professionals, automated SNOTEL data, and modeled water supply/streamflow volume data as well as issues streamflow forecasts for over 740 locations in the West. The data and the related reports and forecasts, are made available—in near real time for the automated SNOTEL sites—to private industry; to Federal, State, and local government entities; and to private citizens through an extensive Internet delivery system and other distribution channels. With 50-80 percent of the water supply in the West arriving in the form of snow, data on the snowpack provides critical information to decision-makers and water managers throughout the West. The basic data become even more valuable when used in concert with partner organizations to provide water supply forecasting tailored to meet end-user needs. According to researchers from multiple U.S. and international agencies, research centers, and academia, changes in the world’s climate have resulted in a loss of predictability in weather, precipitation, and water transport and accumulation patterns. It is anticipated that the value the SS-WSF Program provides to society will increase over time as climate variability increases. Recently a study was done to see who uses SS-WSF data, how the data are used, and the value of the data. Users of the data were interviewed and specific events and activities were analyzed. This publication is based on that study.

View Document Download Now Email

A Measure of Snow: Case Studies of the Snow Survey and Water Supply Forecasting Program

U.S. Department of Agriculture (USDA) | September 1st, 2010

Summary

Snow depth and snow water content data have been collected and disseminated throughout the W estern United States for over 100 years. Early Snow Survey and Wate

Snow depth and snow water content data have been collected and disseminated throughout the W estern United States for over 100 years. Early Snow Survey and Water Supply Forecasting data were gathered through the efforts of university scientists. In 1935, the Soil Conservation Service (SCS) was given $36,000 to establish a formal cooperative Snow Survey and Water Supply Forecasting (SSWSF) Program. The agency was charged with the responsibility for “conducting Snow Survey and Water Supply Forecast s and forecasting of irrigation water supplies.” The new program would also develop consistent methods for measuring snow and reliable models for water supply forecasting. Using a case study approach, this report assesses the various uses of data gathered and published by the SSWSF Program and estimates the value of those data in terms of both the market and non-market values of the information. Additionally, it evaluate s the relative merits of maintaining the program as a publicly funded program as opposed to privatizing the program. This study finds that the SSWSF Program is generating both market and non-market benefits to the U.S. economy and to U.S. society as a whole that are worth significantly more than the cost of the program. Should climate variability increase — as is expected by many of those interviewed in the course of completing this study, and as current climate research strongly suggests — the value of the information provided by the SSWSF Program will increase accordingly.

View Document Download Now Email

A Multidataset Assessment of Climatic Drivers and Uncertainties of Recent Trends in Evaporative Demand across the Continental United States

American Meteorological Society (AMS) | April 1st, 2022

Summary

Increased atmospheric evaporative demand has important implications for humans and ecosystems in water-scarce lands. While temperature plays a significant role in drivin

Increased atmospheric evaporative demand has important implications for humans and ecosystems in water-scarce lands. While temperature plays a significant role in driving evaporative demand and its trend, other climate variables are also influential and their contributions to recent trends in evaporative demand are unknown. We address this gap with an assessment of recent (1980–2020) trends in annual reference evapotranspiration (ETo) and its drivers across the continental United States based on five gridded datasets. In doing so, we characterize the structural uncertainty of ETo trends and decompose the relative influences of temperature, wind speed, solar radiation, and humidity. Results highlight large and robust changes in ETo across much of the western United States, centered on the Rio Grande region where ETo increased 135–235 mm during 1980–2020. The largest uncertainties in ETo trends are in the central and eastern United States and surrounding the Upper Colorado River. Trend decomposition highlights the strong and widespread influence of temperature, which contributes to 57% of observed ETo trends, on average. ETo increases are mitigated by increases in specific humidity in non-water-limited regions, while small decreases in specific humidity and increases in wind speed and solar radiation magnify ETo increases across the West. Our results show increases in ETo across the West that are already emerging outside the range of variability observed 20–40 years ago. Our results suggest that twenty-first-century land and water managers need to plan for an already increasing influence of evaporative demand on water availability and wildfire risks. SIGNIFICANCE STATEMENT: Increased atmospheric thirst due to climate warming has the potential to decrease water availability and increase wildfire risks in water-scarce regions. Here, we identified how much atmospheric thirst has changed across the continental United States over the past 40 years, what climate variables are driving the change, and how consistent these changes are among five data sources. We found that atmospheric thirst is consistently emerging outside the range experienced in the late twentieth century in some western regions with 57% of the change driven by temperature. Importantly, we demonstrate that increased atmospheric thirst has already become a persistent forcing of western landscapes and water supplies toward drought and will be an essential consideration for land and water management planning going forward.

View Document Download Now Email

A multiscale model for El Niño complexity

Nature Portfolio (Springer Nature) | March 11th, 2022

Summary

El Niño-Southern Oscillation (ENSO) exhibits diverse characteristics in spatial pattern, peak intensity, and temporal evolution. Here we develop a three-region multiscal

El Niño-Southern Oscillation (ENSO) exhibits diverse characteristics in spatial pattern, peak intensity, and temporal evolution. Here we develop a three-region multiscale stochastic model to show that the observed ENSO complexity can be explained by combining intraseasonal, interannual, and decadal processes. The model starts with a deterministic three-region system for the interannual variabilities. Then two stochastic processes of the intraseasonal and decadal variation are incorporated. The model can reproduce not only the general properties of the observed ENSO events, but also the complexity in patterns (e.g., Central Pacific vs. Eastern Pacific events), intensity (e.g., 10–20 year reoccurrence of extreme El Niños), and temporal evolution (e.g., more multi-year La Niñas than multi-year El Niños). While conventional conceptual models were typically used to understand the dynamics behind the common properties of ENSO, this model offers a powerful tool to understand and predict ENSO complexity that challenges our understanding of the twenty-first century ENSO.

View Document Download Now Email

A spatially comprehensive, hydrometeorological data set for Mexico, the U.S., and Southern Canada 1950–2013

Nature Portfolio (Springer Nature) | August 18th, 2015

Summary

A data set of observed daily precipitation, maximum and minimum temperature, gridded to a 1/16° (~6 km) resolution, is described that spans the entire country

A data set of observed daily precipitation, maximum and minimum temperature, gridded to a 1/16° (~6 km) resolution, is described that spans the entire country of Mexico, the conterminous U.S. (CONUS), and regions of Canada south of 53° N for the period 1950–2013. The dataset improves previous products in spatial extent, orographic precipitation adjustment over Mexico and parts of Canada, and reduction of transboundary discontinuities. The impacts of adjusting gridded precipitation for orographic effects are quantified by scaling precipitation to an elevation-aware 1981–2010 precipitation climatology in Mexico and Canada. Differences are evaluated in terms of total precipitation as well as by hydrologic quantities simulated with a land surface model. Overall, orographic correction impacts total precipitation by up to 50% in mountainous regions outside CONUS. Hydrologic fluxes show sensitivities of similar magnitude, with discharge more sensitive than evapotranspiration and soil moisture. Because of the consistent gridding methodology, the current product reduces transboundary discontinuities as compared with a commonly used reanalysis product, making it suitable for estimating large-scale hydrometeorologic phenomena.

View Document Download Now Email

A tale of two California droughts: Lessons amidst record warmth and dryness in a region of complex physical and human geography

American Geophysical Union (AGU) | November 19th, 2015

Summary

The state of California has experienced the worst drought in its historical record during 2012–2015. Adverse effects of this multi year event have been far from unifor

The state of California has experienced the worst drought in its historical record during 2012–2015. Adverse effects of this multi year event have been far from uniformly distributed across the region, ranging from remarkably mild in most of California’s densely populated coastal cities to very severe in more rural, agricultural, and wildfire-prone regions. This duality of impacts has created a tale of two very different California droughts—highlighting enhanced susceptibility to climate stresses at the environmental andsocioeconomic margins of California. From a geophysical perspective, the persistence of related atmospheric anomalies has raised a number of questions regarding the drought’s origins—including the role of anthropogenic climate change. Recent investigations underscore the importance of understanding the underlying physical causes of extremes in the climate system, and the present California drought represents an excellent case study for such endeavors. Meanwhile, a powerful El Niño event in the Pacific Ocean offers the simultaneous prospect of partial drought relief but also an increased risk of flooding during the 2015–2016 winter—a situation illustrative of the complex hydroclimatic risks California and other regions are likely to face in a warming world.

View Document Download Now Email

A Twenty-First-Century California Observing Network for Monitoring Extreme Weather Events

American Meteorological Society (AMS) | August 27th, 2013

Summary

During Northern Hemisphere winters, the West Coast of North America is battered by extratropical storms. The impact of these storms is of paramount concern to California,

During Northern Hemisphere winters, the West Coast of North America is battered by extratropical storms. The impact of these storms is of paramount concern to California, where aging water supply and flood protection infrastructures are challenged by increased standards for urban flood protection, an unusually variable weather regime, and projections of climate change. Additionally, there are inherent conflicts between releasing water to provide flood protection and storing water to meet requirements for the water supply, water quality, hydropower generation, water temperature and flow for at-risk species, and recreation. To improve reservoir management and meet the increasing demands on water, improved forecasts of precipitation, especially during extreme events, are required. Here, the authors describe how California is addressing their most important and costliest environmental issue-water management-in part, by installing a state-of-the-art observing system to better track the area's most severe wintertime storms.

View Document Download Now Email

Advances in Sub-seasonal to Seasonal Prediction Relevant to Water Management in the Western United States

American Meteorological Society (AMS) | July 21st, 2022

Summary

Water management in the semi-arid western United States (U.S.) is a challenging endeavor that evolves from year to year based on large-scale atmospheric and oceanic condi

Water management in the semi-arid western United States (U.S.) is a challenging endeavor that evolves from year to year based on large-scale atmospheric and oceanic conditions. This region has frequently experienced prolonged periods of drought with substantial socioeconomic impacts; the most recent instance involves California entering its third consecutive drought year. As context for the economic implications of drought, California’s enacted state budget for the Fiscal Year 2021-22 authorizes more than $600 million for the California Department of Water Resources for providing immediate drought support to local water agencies (CA State Budget 2021a); this amount is part of a package of more than $5 billion over four years for water resilience and drought preparedness (CA State Budget 2021b). For drought preparedness, state and local water managers would like to rely on skillful forecasts on timescales that span the spectrum between weather forecasts and climate predictions. Despite recent improvements in developing sub-seasonal (2- to 6-weeks lead) and seasonal (2- to 6-months lead) prediction systems that compete with and/or outperform existing dynamical and statistical models (e.g., Gibson et al. 2021, Switanek et al. 2020, DeFlorio et al. 2019), forecasting limitations have hindered crucial management decisions for western U.S. water managers, especially related to longer-lead planning, budgeting, resource allocation, and better preparedness for wet and dry extremes (DeFlorio et al. 2021). Improved understanding of physical phenomena and processes governing weather and climate extremes and utilization of emerging forecast methodologies are critical to developing skillful S2S forecast products relevant to water management.

View Document Download Now Email

Page : 1

Type

Book/Textbook (1)
Bulletin (3)
California Water Plan (4)
Case study (6)
Conference proceedings (3)
Essay (1)
Fact sheet (2)
Groundwater Sustainability Plan (GSP) review findings (1)
Guidance Document (2)
Handbook/Guide (1)
Journal Article (127)
magazine (2)
Manual (2)
Model (51)
NGO Position Paper (1)
Policy (1)
Policy Brief (1)
Report (17)
Research Article (1)
Science Panel Report (4)
Technical Report (6)
White Paper (1)

Topic

Agriculture (4)
Basic Information (1)
Climate Change (122)
Drought & Hydrology (54)
Ecosystem & Species Management (6)
Estuary News (2)
Flood Management (63)
Geohydrology (1)
Geohydrology (1)
Groundwater (6)
History (5)
Human Right to Water (1)
Infrastructure (6)
Integrated Regional Water Management (1)
Levees (1)
Modeling (87)
Planning & Management (43)
Sacramento-San Joaquin Delta (7)
Science Management (4)
Storage (7)
Stormwater (8)
Uncategorized (1)
Upper Watershed Management (13)
Water & Energy (3)
Water Project Operations (8)
Water Quality (1)
Water Supply (148)
Water Use & Efficiency (1)

Keywords

agriculture (4)
agriculture water use and efficiency (1)
anadromous fish (1)
atmospheric rivers (57)
California Water Plan (1)
Central Valley (5)
Central Valley Project (CVP) (1)
climate change (117)
Colorado River (10)
conjunctive use (1)
debris flow (1)
Delta conveyance (1)
disadvantaged communities (DACs) (1)
drought (40)
earthquake (1)
ecosystem management (4)
Estuary News (2)
flood management (79)
flows (4)
Gravity Recovery and Climate Experiment (GRACE) (1)
groundwater (1)
Groundwater Exchange (8)
groundwater pumping impacts (3)
groundwater recharge (1)
Groundwater Sustainability Plan (GSP) (1)
history (6)
infrastructure (6)
irrigation (1)
land use (2)
modeling (94)
monitoring (4)
planning and management (29)
pollutants (1)
risk assessment (18)
Sacramento–San Joaquin Delta (8)
salinity (1)
science management (2)
sea level rise (2)
sediment (1)
snowpack (19)
State Water Project (SWP) (2)
storage (8)
stormwater (8)
streams (3)
Sustainable Groundwater Management Act (SGMA) (1)
upper watershed management (5)
urban water conservation (1)
water and energy (1)
water markets (1)
water project operations (6)
water supply (5)
water supply forecasting (183)

Publisher

American Association for the Advancement of Science (AAAS) (2)
American Geophysical Union (AGU) (40)
American Meteorological Society (AMS) (40)
American Water Resources Association (AWRA) (2)
California Department of Water Resources (DWR) (16)
California Energy Commission (CEC) (2)
California Public Utilities Commission (CPUC) (1)
Climate (MDPI) (1)
Climate Dynamics (Springer) (4)
Climatic Change (Springer) (1)
Delta Stewardship Council (Delta Council) (2)
Earth Science Reviews (Elsevier) (1)
Ecological Society of America (ESA) (1)
Hydrology (MDPI) (1)
International Association for Hydro-Environment Engineering and Research (1)
Journal of Hydrology (Elsevier) (1)
National Academy of Sciences (NAS) (3)
Nature Portfolio (Springer Nature) (41)
Pacific Institute (1)
Public Policy Institute of California (PPIC) (1)
Royal Meteorological Society (RMS) (1)
San Francisco Estuary Partnership (SFEP) (2)
Scientific American (1)
U.S. Bureau of Reclamation (USBR) (4)
U.S. Department of Agriculture (USDA) (4)
U.S. Geological Survey (USGS) (3)
U.S. Global Change Research Program (1)
University of California, Davis (UC Davis) (2)
University of Colorado, Boulder (1)
Utah State University (1)
Water (MDPI) (1)

Basin

San Joaquin Valley - Kern 5-022.14 (1)

Hydrological Region

Central Coast (35)
Colorado River (30)
Lower Basin States and Mexico - Colorado River (60)
National (24)
North Coast (39)
North Lahontan (32)
Sacramento River (52)
San Francisco Bay (37)
San Joaquin River (45)
South Coast (40)
South Lahontan (34)
Tulare Lake (34)
Upper Basin States - Colorado River (44)

Reset

Search for:

CONTACT