climate change

Search Results

Browse All Documents

A freshwater conservation blueprint for California: prioritizing watersheds for freshwater biodiversity

Add to Downloads

A freshwater conservation blueprint for California: prioritizing watersheds for freshwater biodiversity
Freshwater Science, University of Chicago Press Journals | April 18, 2018...
Summary
Conservation scientists have adapted conservation planning principles designed for protection of habi- tats ranging from terrestrial to freshwater ecosystems. We applied current approaches...

Conservation scientists have adapted conservation planning principles designed for protection of habi- tats ranging from terrestrial to freshwater ecosystems. We applied current approaches in conservation planning to prioritize California watersheds for management of biodiversity. For all watersheds, we compiled data on the pre- sence/absence of herpetofauna and fishes; observations of freshwater-dependent mammals, selected invertebrates, and plants; maps of freshwater habitat types; measures of habitat condition and vulnerability; and current manage- ment status. We analyzed species-distribution data to identify areas of high freshwater conservation value that op- timized representation of target taxa on the landscape and leveraged existing protected areas. The resulting priority network encompasses 34% of the area of California and includes ≥10% of the geographic range for all target taxa. High-value watersheds supported nontarget freshwater taxa and habitats, and focusing on target taxa may provide broad conservation value. Most of the priority conservation network occurs on public lands (69% by area), and 46% overlaps with protected areas already managed for biodiversity. A significant proportion of the network area is on private land and underscores the value of programs that incentivize landowners to manage freshwater species and habitats. The priority conservation areas encompass more freshwater habitats/ha than existing protected areas. Land use (agriculture and urbanization), altered fire regimes, nonnative fish communities, and flow impairment are the most important threats to freshwater habitat in the priority network, whereas factors associated with changing climate are the key drivers of habitat vulnerability. Our study is a guide to a comprehensive approach to freshwater conservation currently lacking in California. Conservation resources are often limited, so prioritiza- tion tools are valuable assets to land and water managers.

View Document
Become a member to access this feature
Download NowEmail Details
A spatially comprehensive, hydrometeorological data set for Mexico, the U.S., and Southern Canada 1950–2013

Add to Downloads

A spatially comprehensive, hydrometeorological data set for Mexico, the U.S., and Southern Canada 1950–2013
Nature | August 18, 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...

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
Become a member to access this feature
Download NowEmail Details
Accounting for Climate Change
$0.00
Add to Downloads

Accounting for Climate Change
Department of Water Resources | April 29, 2010...
Summary
In recent years, evidence that global climate will have significant effects on water resources in California has continued to accumulate. Climate change can...
In recent years, evidence that global climate will have significant effects on water resources in California has continued to accumulate. Climate change can affect the amount, timing, and form of precipitation, whether rain or snow, that California receives, as well as the sea level of the Pacific Ocean. Moreover, changes in weather, especially temperature, and atmospheric composition can affect water use and consumption. Changes in climate have occurred during the 20th century, with noticeable warming in the last two decades.

Most scientists feel that changes during the last several decades are likely mostly due to human activities, but natural causes and variability cannot be ruled out as a significant component. Likewise, projections of amount of warming and other climate changes during the 21st century are wide ranging, depending on assumptions and models.

A major cause of expected climate change is the increasing amounts of greenhouse gases, such as carbon dioxide, in the atmosphere as a result of man’s activities. These gases, as well as water vapor, allow solar radiation to pass inward through the atmosphere, but trap the longer wave infrared radiation reflected back from the earth’s surface. Greenhouse gases are accumulating in the atmosphere; the following chart shows the gradual build up in carbon dioxide at Mauna Loa in Hawaii, as measured by Scripps Institution of Oceanography scientists. The annual cycle is caused by northern hemisphere vegetation uptake during the growing season. Other significant greenhouse gases are methane, nitrous oxide, halocarbons (like freon and its replacements), and, of course, water vapor itself. Cloud cover is an important element in the global radiation balance.

Whatever the causes, the prospects of significant changes warrant examination of how the State’s water infrastructure and natural systems can accommodate or adapt to climate changes and whether more needs to be done to detect, evaluate and respond to water resource system effects. Many uncertainties remain, primarily on the degree of change to be expected. Responsible planning requires that the California water planning community work with climate scientists and others to reduce these uncertainties and to begin to prepare for those impacts that are well understood, already appearing as trends, or likely to appear. In this section we review possible impacts and address some of the responses appropriate for water planners and managers.

View Document
Become a member to access this feature
Download NowEmail Details
Adaptation Strategies for Agricultural Sustainability in Yolo County, California
$0.00
Add to Downloads

Adaptation Strategies for Agricultural Sustainability in Yolo County, California
California Energy Commission (CEC) | July 31, 2012...
Summary
This place-based case study in an agricultural county in California’s Central Valley focused on the period of 2010–2050, and dealt with biophysical and...
This place-based case study in an agricultural county in California’s Central Valley focused on the period of 2010–2050, and dealt with biophysical and socioeconomic issues related to both mitigation of greenhouse gas (GHG) emissions and to adaptation to an uncertain climate. In the past 100 years, changes in crop acreage has been more related to crop price and availability of irrigation water than to growing degree days during summer, and in fact, summer temperatures have increased less than winter temperatures. Econometric analysis indicated that warmer winters, as projected by Geophysical Fluid Dynamics Laboratory-Bias Corrected Constructed Analog during 2035–2050, could result in less wheat acreage, more alfalfa and tomato acreage, and slight effects on tree and vine crops. The Water Evaluation and Planning (WEAP) model showed that these econometric projections did not reduce irrigation demand under either the B1 or A2 scenarios, but a diverse, water-efficient cropping pattern combined with improved irrigation technology reduced demand to 12 percent below the historic mean.

Collaboration during development of Yolo County’s Climate Action Plan showed that nitrous oxide (mainly from nitrogen fertilizers) was the main source (40 percent) of agricultural emissions. Emissions from cropland and rangeland were several orders of magnitude lower than urbanized land per unit area. A survey distributed to 570 farmers and ranchers achieved a 34 percent response rate. Farmers concerned about climate change were more likely to implement water conservation practices, and adopt voluntary GHG mitigation practices.

Use of the urban growth model (UPlan) showed that channeling much or all future urban development into existing urban areas will increase ecosystem services by preserving agricultural land and open space, immensely reducing the Yolo County’s GHG emissions, and greatly enhancing agricultural sustainability.

View Document
Become a member to access this feature
Download NowEmail Details
Adapting California’s Water Management to Climate Change
$0.00
Add to Downloads

Adapting California’s Water Management to Climate Change
Public Policy Institute of California (PPIC) | January 12, 2009...
Summary
Among the potential impacts of climate change, accelerated sea level rise and a reduced Sierra snowpack are the most certain. Both will pose...
Among the potential impacts of climate change, accelerated sea level rise and a reduced Sierra snowpack are the most certain. Both will pose significant challenges for water supply and flood management. Water utilities have already begun to plan for these changes, but flood control agencies are lagging behind and face greater regulatory constraints. State leadership is needed to resolve some threats, including the risk of catastrophic failure in the Sacramento-San Joaquin Delta. This report was prepared as part of the Preparing California for a Changing Climate project.

View Document
Become a member to access this feature
Download NowEmail Details
Adapting to Climate Change and Drought in Selected California Groundwater Basins: Local Achievements and Challenges

Add to Downloads

Adapting to Climate Change and Drought in Selected California Groundwater Basins: Local Achievements and Challenges
California Natural Resources Agency | August 27, 2018...
Summary
Climate change projections are for higher temperatures and extreme droughts by the end of the 21st century. This will alter the natural recharge...
Climate change projections are for higher temperatures and extreme droughts by the end of the 21st century. This will alter the natural recharge of groundwater, including decreased inflow from runoff, increased evaporative losses, and warmer and shorter winter seasons, impacts that are likely to exacerbate already existing groundwater overdraft in many basins. Additionally, the imported surface water that can be delivered from the Central Valley Project (CVP) and State Water Project (SWP) to areas reliant on this water for groundwater recharge and consumptive use is projected to be less reliable and more expensive. Yet groundwater is a critical water supply source during drought when it compensates for reduced surface water supplies. The need for proactive adaptation strategies to address the extreme droughts projected under climate change are frequently discussed, yet there are limited examples of such groundwater management strategies. This paper therefore explores:

1) How groundwater management agencies are planning for drought

2) What new approaches are currently being used that show promise for addressing the more extreme droughts projected under climate change?

View Document
Become a member to access this feature
Download NowEmail Details
Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 1: Water Rights Administration and Oversight During Major Statewide Droughts, 1976–2016

Add to Downloads

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 1: Water Rights Administration and Oversight During Major Statewide Droughts, 1976–2016
California Natural Resources Agency | August 30, 2018...
Summary
Climate change has already begun to affect California’s hydrology and water resources, and droughts are likely to become more frequent, longer, and more...

Climate change has already begun to affect California’s hydrology and water resources, and droughts are likely to become more frequent, longer, and more intense in the future (see Section 2.2.4). This project is designed to help state water governance and decision-making structures adapt to this changing climatic reality. We focus on how one of California’s primary water management institutions, the State Water Resources Control Board (Board), has responded in the past, and could better respond in the future, to droughts and their attendant challenges, including water shortage, uncertainty, and conflict.

Click here for Part 2.

View Document
Become a member to access this feature
Download NowEmail Details
Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 2: Improving Water Rights Administration and Oversight for Future Droughts

Add to Downloads

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 2: Improving Water Rights Administration and Oversight for Future Droughts
California Natural Resources Agency | August 30, 2018...
Summary
In California, droughts are likely to become more frequent, longer, and more intense in the future, posing increasing challenges for water management, and...
In California, droughts are likely to become more frequent, longer, and more intense in the future, posing increasing challenges for water management, and raising the stakes for effective drought response. This project aims to help state water governance and decision-making structures adapt to the changing climatic reality. In a companion report in this volume, we analyzed the strategies the State Water Resources Control Board (Board) used for water rights administration and oversight during the last four major statewide droughts. Our findings suggest that more proactive planning and preparation, enabling reduced reliance on in-drought improvisation, would improve the Board’s future drought responses. This report builds on that retrospective analysis with specific recommendations.

Click here for Part 1.

View Document
Become a member to access this feature
Download NowEmail Details
Advancing Hydro-Economic Optimization to Identify Vulnerabilities and Adaptation Opportunities in California’s Water System

Add to Downloads

Advancing Hydro-Economic Optimization to Identify Vulnerabilities and Adaptation Opportunities in California’s Water System
California Natural Resources Agency | August 27, 2018...
Summary
Long-term shifts in the timing and magnitude of reservoir inflows will affect water supply reliability in California. Hydro-economic models can help explore climate...
Long-term shifts in the timing and magnitude of reservoir inflows will affect water supply reliability in California. Hydro-economic models can help explore climate change concerns by identifying system vulnerabilities and adaptation strategies for statewide water operations. This work contributes a new open-source limited foresight implementation of the CALVIN model, a hydro-economic model including roughly 90% of California’s urban and agricultural water demands. The model includes the ability to determine water allocations on an annual basis without knowledge of future availability, and to efficiently evaluate ensembles of streamflow projections representing a range of possible future climates. We then assess the vulnerability of the statewide system to changes in total annual runoff and the fraction of runoff occurring during winter, which primarily depends on temperature. Results are analyzed with a focus on adaptation strategies, aided by the economic representation of water demand in the model. These strategies include changes to reservoir operating policies, and conveyance and storage expansion. As water availability decreases, model results show quadratic increases in shortage cost, and corresponding increases in the marginal costs of adaptation strategies and environmental flow constraints. Reservoirs adapt to warmer climates by increasing average storage levels in winter and routing excess runoff to downstream reservoirs with available capacity. Both small and large changes to reservoir operations were observed compared to historical hydrology, showing that no single operating strategy achieves optimality for all reservoirs. Increasing the fraction of winter flow causes small increases in total shortage cost, indicating the ability to manage a changing hydrologic regime with adaptive reservoir operations. The results of this project improve estimates of the cost of climate change to California’s water system under a range of future conditions and highlight adaptation strategies that minimize costs of increased hydrologic variability.

View Document
Become a member to access this feature
Download NowEmail Details
Agricultural Damages and Losses from ARkStorm Scenario Flooding in California

Add to Downloads

Agricultural Damages and Losses from ARkStorm Scenario Flooding in California
American Society of Civil Engineers (ASCE) | November 17, 2016...
Summary
Scientists designed the ARkStorm scenario to challenge the preparedness of California communities for widespread flooding with a historical precedence and increased likelihood under...

Scientists designed the ARkStorm scenario to challenge the preparedness of California communities for widespread flooding with a historical precedence and increased likelihood under climate change. California is an important provider of vegetables, fruits, nuts, and other agricultural products to the nation. This study analyzes the agricultural damages and losses pertaining to annual crops, perennial crops, and livestock in California exposed to ARkStorm flooding. Statewide, flood damage is incurred on approximately 23% of annual crop acreage, 5% of perennial crop acreage, and 5% of livestock, e.g., dairy, feedlot, and poultry, acreage. The sum of field repair costs, forgone income, and product replacement costs span $3.7 and $7.1 billion (2009) for a range of inundation durations. Perennial crop loss estimates dominate, and the vulnerability of orchards and vineyards has likely increased with recent expansion. Crop reestablishment delays from levee repair and dewatering more than double annual crop losses in the delta islands, assuming the fragile system does not remain permanently flooded. The exposure of almost 200,000 dairy cows to ARkStorm flooding poses livestock evacuation challenges.

View Document
Become a member to access this feature
Download NowEmail Details

Search

climate change

Search

Browse All Documents

Type

Topic

Keywords

Publisher

Publication Year

Hydrologic Region

Index By

A freshwater conservation blueprint for California: prioritizing watersheds for freshwater biodiversity

A freshwater conservation blueprint for California: prioritizing watersheds for freshwater biodiversity

Become a member to access this feature

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

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

Become a member to access this feature

Accounting for Climate Change

Accounting for Climate Change

Become a member to access this feature

Adaptation Strategies for Agricultural Sustainability in Yolo County, California

Adaptation Strategies for Agricultural Sustainability in Yolo County, California

Become a member to access this feature

Adapting California’s Water Management to Climate Change

Adapting California’s Water Management to Climate Change

Become a member to access this feature

Adapting to Climate Change and Drought in Selected California Groundwater Basins: Local Achievements and Challenges

Adapting to Climate Change and Drought in Selected California Groundwater Basins: Local Achievements and Challenges

Become a member to access this feature

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 1: Water Rights Administration and Oversight During Major Statewide Droughts, 1976–2016

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 1: Water Rights Administration and Oversight During Major Statewide Droughts, 1976–2016

Become a member to access this feature

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 2: Improving Water Rights Administration and Oversight for Future Droughts

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 2: Improving Water Rights Administration and Oversight for Future Droughts

Become a member to access this feature

Advancing Hydro-Economic Optimization to Identify Vulnerabilities and Adaptation Opportunities in California’s Water System

Advancing Hydro-Economic Optimization to Identify Vulnerabilities and Adaptation Opportunities in California’s Water System

Become a member to access this feature

Agricultural Damages and Losses from ARkStorm Scenario Flooding in California

Agricultural Damages and Losses from ARkStorm Scenario Flooding in California

Become a member to access this feature