Download or read book Climate Change and California Surface Hydrology written by Marla Ann Schwartz and published by . This book was released on 2016 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding 21st century changes in California surface hydrology is critical to ensuring enough freshwater resources for the state's municipal, ecological and agricultural purposes and assessing future ecosystem health and wildfire risk. To project 21st century surface hydrology over California - a region with highly complex topography that is not well captured by global climate models (GCMs) - downscaling is necessary. This work projects future changes in surface hydrology over the Los Angeles and Sierra Nevada regions through dynamical and statistical downscaling techniques. Dynamical downscaling is employed over Los Angeles to produce 2-km resolution regional projections for the mid-21st-century under an aggressive warming scenario. These projections reveal annual mean runoff and actual evapotranspiration are nearly insensitive to warming. This insensitivity is an artifact of the region's Mediterranean-type climate: Because the warm season receives almost no precipitation, the strongest warming-induced potential evapotranspiration enhancement coincides with dry soils, severely constraining actual evapotranspiration increases. This surprising result highlights that this important semi-arid region is less susceptible to long-term changes in runoff and soil moisture due to its Mediterranean climate. Over the Sierra Nevada Mountains, dynamical downscaling is used to produce high-resolution (3-km) simulations of end-of-21st-century surface hydroclimate. The high resolution and physical realism of these simulations provides unprecedented detail into the elevational dependence of hydroclimate changes and allows us to examine hydroclimate changes at the watershed level. These downscaled simulations reveal future warming leads to a shift toward significantly earlier snowmelt-driven surface runoff timing at each elevation throughout the Sierra Nevada, particularly in mid-elevations (2000-2750m) in the western and northern Sierra. Moreover, these projections show that any precipitation increases are outweighed by warming induced snowpack reductions and evapotranspiration increases, resulting in statistically significant drying of spring and summer soils and a substantial lengthening of the summer dry period. Relationships and patterns that emerge through dynamical downscaling over the Sierra Nevada are exploited to build simple statistical models that mimic dynamical model behavior. Using this hybrid dynamical-statistical downscaling model, high-resolution end-of-21st-century runoff timing and soil moisture changes are projected for all available GCMs from phase 5 of the Coupled Model Intercomparison Project and the four forcing scenarios adopted by the Intergovernmental Panel on Climate Change's Fifth Assessment Report. These multi-model projections allow us to quantify and characterize ensemble-mean changes and the associated uncertainty due to inter-model GCM spread, as well as the consequences associated with choice of emissions scenario. Averaged across the Sierra, April-September soil moisture is projected to decrease 17.1% in the 35-model ensemble mean under RCP8.5 (with an approximate intermodel range of -12.9% to -21.0%), but only 9.1% with an approximate intermodel range of -5.7% to -12.9%) under RCP4.5, a reasonable mitigation scenario.
Download or read book Mid 21st Century Changes to Surface Hydrology Over the Los Angeles Region written by Marla Ann Schwartz and published by . This book was released on 2013 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis explores projected mid-21st century changes to surface hydrological fluxes and states in the Los Angeles region at 2km resolution. This work quantifies and describes potential impacts of climate change to precipitation, runoff, evapotranspiration and soil column moisture content in the Los Angeles region. Little previous research has focused on the impacts of climate change to water resources and surface hydrology in this region. We simulate detailed climatologies of surface hydrology for the late 20th century and mid 21st century. By looking at differences between the future and baseline periods, mid-century changes to surface hydrology relative to the late 20th century can be evaluated in our study region. Using dynamical downscaling techniques and the Weather Research and Forecasting (WRF) model, we develop a detailed high-resolution climatology for the Los Angeles region from coarse-resolution North America Regional Reanalysis (NARR) data and output from five "business as usual" global climate model (GCMs) simulations in the Fifth Coupled Model Intercomparison Project (CMIP5) data archive. Output from the dynamical downscaling WRF simulations is then used to force the offline Noah Land Surface Model (Noah & ndashLSM), which simulates near-surface state variables and surface turbulent fluxes. This methodology allows us to assess potential impacts of climate change to surface hydrology in the Los Angeles region at scales relevant to local policy makers or water resources planners.
Download or read book Modeling the Impacts of Climate Change on Hydrology and Agricultural Pollutant Runoff in California s Central Valley written by Darren L. Ficklin and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Soil and Water Assessment Tool (SWAT) and HYDRUS were used to assess the impact of climate change on the hydrologic cycle (streamflow, surface runoff, groundwater recharge, evapotranspiration, and irrigation water use) and agricultural pollutant runoff (sediment, nitrate, phosphorus, chlorpyrifos, and diazinon) in the Sacramento and San Joaquin River watersheds in California's Central Valley. Five separate studies were constructed. For the first three studies, hydrological responses were modeled in the San Joaquin River watershed using variations of atmospheric CO2 (550 and 970 ppm), temperature (+1.1 and +6.4°C), and precipitation (0%, ±10%, and ±20%) based on Intergovernmental Panel on Climate Change projections. The fourth study used a calibration and an uncertainty analysis technique for the calibration of the Sacramento River watershed. This study confirmed that SWAT was able to capture the large amount of uncertainty within the Sacramento River watershed and successfully simulate streamflow, sediment, nitrate, chlorpyrifos and diazinon loads. The final study used a novel stochastic climate change analysis technique to bracket the 95% confidence interval of potential climate changes. For all studies, increases in precipitation generally changed the hydrological cycle and agricultural runoff proportionally, where increases in precipitation resulted in increases in surface runoff and thus agricultural runoff and vice-versa. Also, for all studies, increasing temperature caused a temporal shift in plant growth patterns and redistributed evapotranspiration and irrigation water demand earlier in the year. Increasing atmospheric CO2 resulted in watershed-wide decreases in evapotranspiration, therefore increasing water yield and streamflow while concurrently decreasing irrigation water use. This research improves the understanding between climate change and hydrology and agricultural pollutant runoff within the Central Valley of California. Theses climate change analyses may be used by water resource managers to evaluate the potential effects of climate change.
Download or read book Water written by Peter H. Gleick and published by . This book was released on 2000 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Potential Effects of Climate Change on Streamflow Eastern and Western Slopes of the Sierra Nevada California and Nevada written by Anne E. Jeton and published by . This book was released on 1996 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Change Impacts Upon Agriculture and Resources written by Daniel J. Dudek and published by . This book was released on 1988 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Change and Water written by Carol Howe and published by IWA Publishing. This book was released on 2010 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Professionals are sure to understand the effects of climate change on urban water and wastewater utilities with this collection of international scientific papers. Case studies and practical planning, mitigating, and adapting information are provided on greenhouse gases, energy use, and water supply and quality issues.
Download or read book A 2xCo2 Climate Change Simulation Over California Using a Integrated Regional Atmospheric hydrologic Model written by Liqin Tan and published by . This book was released on 1997 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book California 2100 written by Bryan C. Weare and published by . This book was released on 2006 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric Rivers written by F. Martin Ralph and published by Springer Nature. This book was released on 2020-07-10 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the standard reference based on roughly 20 years of research on atmospheric rivers, emphasizing progress made on key research and applications questions and remaining knowledge gaps. The book presents the history of atmospheric-rivers research, the current state of scientific knowledge, tools, and policy-relevant (science-informed) problems that lend themselves to real-world application of the research—and how the topic fits into larger national and global contexts. This book is written by a global team of authors who have conducted and published the majority of critical research on atmospheric rivers over the past years. The book is intended to benefit practitioners in the fields of meteorology, hydrology and related disciplines, including students as well as senior researchers.
Download or read book Sustainable Water and Environmental Management in the California Bay Delta written by National Research Council and published by National Academies Press. This book was released on 2012-10-01 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensively modified over the last century and a half, California's San Francisco Bay Delta Estuary remains biologically diverse and functions as a central element in California's water supply system. Uncertainties about the future, actions taken under the federal Endangered Species Act (ESA) and companion California statues, and lawsuits have led to conflict concerning the timing and amount of water that can be diverted from the Delta for agriculture, municipal, and industrial purposes and concerning how much water is needed to protect the Delta ecosystem and its component species. Sustainable Water and Environmental Management in the California Bay-Delta focuses on scientific questions, assumptions, and conclusions underlying water-management alternatives and reviews the initial public draft of the Bay Delta Conservation Plan in terms of adequacy of its use of science and adaptive management. In addition, this report identifies the factors that may be contributing to the decline of federally listed species, recommend future water-supple and delivery options that reflect proper consideration of climate change and compatibility with objectives of maintaining a sustainable Bay-Delta ecosystem, advises what degree of restoration of the Delta system is likely to be attainable, and provides metrics that can be used by resource managers to measure progress toward restoration goals.
Download or read book California Climate Change Hydrologic Response and Flood Forecasting written by Norman L. Miller and published by . This book was released on 2003 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is strong evidence that the lower atmosphere has been warming at an unprecedented rate during the last 50 years, and it is expected to further increase at least for the next 100 years. Warmer air mass implies a higher capacity to hold water vapor and an increased likelihood of an acceleration of the global water cycle. This acceleration is not validated and considerable new research has gone into understanding aspects of the water cycle (e.g. Miller et al. 2003). Several significant findings on the hydrologic response to climate change can be reported. It is well understood that the observed and expected warming is related to sea level rise. In a recent seminar at Lawrence Berkeley National Laboratory, James Hansen (Director of the Institute for Space Studies, National Aeronautics and Space Administration) stressed that a 1.25 Wm{sup -2} increase in radiative forcing will lead to an increase in the near surface air temperature by 1 C. This small increase in temperature from 2000 levels is enough to cause very significant impacts to coasts. Maury Roos (Chief Hydrologist, California Department of Water Resources) has shown that a 0.3 m rise in sea level shifts the San Francisco Bay 100-year storm surge flood event to a 10-year event. Related coastal protection costs for California based on sea level rise are shown. In addition to rising sea level, snowmelt-related streamflow represents a particular problem in California. Model studies have indicated that there will be approximately a 50% decrease in snow pack by 2100. This potential deficit must be fully recognized and plans need to be put in place well in advance. In addition, the warmer atmosphere can hold more water vapor and result in more intense warm winter-time precipitation events that result in flooding. During anticipated high flow, reservoirs need to release water to maintain their structural integrity. California is at risk of water shortages, floods, and related ecosystem stresses. More research needs to be done to further improve our ability to forecast weather events at longer time scales. Seasonal predictions have been statistical and only recently have studies begun to use ensemble simulations and historical observations to constrain such predictions. Understanding the mechanisms of large-scale atmospheric dynamics and its local impacts remain topics of intensive research. The ability to predict extreme events and provide policy makers with this information, along with climate change and hydrologic response information, will help to guide planning to form a more resilient infrastructure in the future.
Download or read book California Water written by Arthur L. Littleworth and published by Solano Press Books. This book was released on 1995 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Future Regional Climate Change in the Ten Hydrologic Regions of California written by Lisa C. Sloan and published by . This book was released on 2005 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Integrated Water Operations in California written by Mustafa Sahin Dogan and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Several management and climate cases are evaluated with the updated CALVIN, a hydro-economic optimization model of California's inter-tied water supply infrastructure. Updates to the CALVIN model include new projected 2050 agricultural target demands and scarcity penalties, improvements to network-flow representation, especially agricultural, urban, and wildlife refuge demands, and extended surface and ground water hydrology, now covering an 82-year historical inflow hydrology. A new energy price scheme is applied to CALVIN, which incorporates hourly energy price variations into monthly CALVIN operations. Using one constant average price for a month underestimates hydropower revenue and overestimates pumping costs. Hourly-varying moving average prices improved representation of hydropower revenue without creating significant scarcities to agricultural and urban water users. Effects of ending long-term groundwater overdraft in the Central Valley are evaluated with several management cases using CALVIN. The cases include effects of Delta outflow and Delta exports from a "no overdraft" policy. The least cost overdraft that minimizes groundwater pumping and scarcity costs is calculated for the 82-year period. Prohibiting Delta exports result in severe water scarcities south of the Delta. Water operations are more economical when overdraft is ended with adaptations, such as more Delta exports, increased groundwater banking, and water trades, than historical operations with overdraft. Finally, climate change effects under a warmer and drier climate scenario are studied and results are compared to historical hydrology. A drier and warmer climate shifts the timing and magnitude of stream flows. Spring snowmelt decreases and winter flows increase. Modelled reduction in rim inflows averages about 28%. This warmer-drier climate increases water scarcities, but adverse effects can be diminished with water sales, higher Delta exports, more conjunctive use, and wastewater recycling.
Download or read book Climate Change and Groundwater Use Impacts to Groundwater and Spring Hydrology written by Terry T. Fisk and published by . This book was released on 2011 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project evaluates the affects of climate change, and to some degree groundwater pumping, on the magnitude and timing of changes in groundwater levels and spring discharge in the Amargosa Desert in southwest Nevada and a portion of Death Valley National Park in eastern California. This is important because, almost without exception, groundwater is the sole source of water for ecosystem and human needs in southern Nevada and Death Valley National Park. The research focused on how the groundwater flow system in the Amargosa Desert, Nevada and Furnace Creek area of Death Valley National Park will respond to climate change, and comparison of the magnitude of climate response to that of continued groundwater pumping. This research will assist in developing a quantitative understanding of groundwater-spring dynamics so that changes to aquatic ecosystems that depend on groundwater flow may be predicted. The U.S. Geological Survey transient groundwater model for the Death Valley Regional Flow System was used for this project. Impacts to the groundwater flow system corresponding to possible climate change scenarios were simulated by varying recharge in the model. Synthesized results of global circulation climate models downscaled to the Death Valley region indicate average temperature will increase by approximately 3.4°C and average precipitation will decline by approximately 0.33 millimeters per month during the 21 st Century. Simulated groundwater head changes resulting from climate change relative to baseline 20th Century conditions ranged from an increase of 0.34 meters to a decline of 2 meters, depending on the recharge (climate) scenario. Simulated groundwater discharge changes relative to baseline conditions ranged from an increase of 369 m3 /day to a decline of 2,130 m3 /day. The primary conclusion of this project is that climate change will affect the Amargosa Desert and Death Valley groundwater system and will likely exacerbate conditions of limited water supply. However, local and regional groundwater pumping have and will continue to have much greater affect on the groundwater system. Even if climate change results in increased precipitation and recharge, groundwater decline will continue as a result of pumping in the Death Valley regional groundwater flow system.
Download or read book California Drought written by Betsy A. Cody and published by DIANE Publishing. This book was released on 2010-10 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: California experienced severe water supply shortages in 2009, which led to economic disruption across the state, incl. losses in agricultural areas in the western portion of the Central Valley ¿ areas already experiencing declines in the housing industry and the economic downturn in general. At the same time, several fish species whose habitat lie at the heart of California¿s water supply system and throughout its northern rivers are in decline and some face the possibility of extinction. This situation too has had economic implications, resulting in job and income losses in northern California. Contents of this report: (1) Intro.; (2) What is Drought?; (3) Drought in California; (4) Regulatory Restrictions Affecting Water Deliveries; (5) California Water Rights. Illus.
