An Estimated Potentiometric Surface of the Death Valley Region, Nevada and California, Developed Using Geographic Information System and Automated Interpolation Techniques

U.S. Geological Survey (USGS) | July 1st, 1998

An evaluation of atmospheric rivers over the North Pacific in CMIP5 and their response to warming under RCP 8.5

American Geophysical Union (AGU) | November 13th, 2015

Landfalling atmospheric rivers over the North Pacific are evaluated in historical (1980–2005) simulations from 28 models participating in the fifth phase of the Couple

Landfalling atmospheric rivers over the North Pacific are evaluated in historical (1980–2005) simulations from 28 models participating in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) and compared to the Modern-Era Retrospective Analysis for Research and Applications and ERA-Interim reanalyses. Landfalling dates are identified as having spatially elongated high wind and moisture features in physical proximity to the coastline. Model performance relative to reanalysis is found to be quite variable. The majority can resolve the spatial structure of landfalling events, but few correctly resolve the frequency distribution, interannual variability in number and amplitude of moisture flux, and median landfalling latitude. The response of a subset of high-performing models to projected warming at the end of the 21st century is investigated using Representative Concentration Pathway (RCP) 8.5 (2070–2100) projections. Selected models show a broadening of the frequency distribution, with the largest increase in frequency occurring equatorward of peak historical frequency. While there is a robust increase in AR-related moisture transport compared to the historical period, this increase is not linked to more extreme AR events within the context of the projected future climate. The occurrence of years with many AR dates is greater at the end of the 21st century than during the historical period. The equatorward increase in peak historical frequency is colocated with increases in the 850 and 250 hPa zonal winds. The response in moisture flux to warming is mostly thermodynamic, but equatorward of its peak distribution, it is dominated by a dynamic response.

An Evaluation of California’s Adjudicated Groundwater Basins

University of California, Santa Cruz (UC Santa Cruz) | October 1st, 2016

Groundwater is a critical resource in California, providing on average 30 percent of the state’s total water supply and significantly more during dry years. Many commu

Groundwater is a critical resource in California, providing on average 30 percent of the state’s total water supply and significantly more during dry years. Many communities rely exclusively on groundwater, and it is an essential back-up source of water during droughts when pumping increases significantly to compensate for reduced surface supplies. Local groundwater management agencies, special act districts, and court adjudications are the primary institutional arrangements to manage groundwater in California. Increasing groundwater declines in many areas of the state and concomitant negative impacts prompted the passage of the 2014 Sustainable Groundwater Management Act (SGMA). The SGMA established new requirements for 127 high- and medium-priority groundwater basins that are either in overdraft or vulnerable to overdraft to develop sustainable management programs with increased state oversight. The SGMA defines sustainable groundwater management as: “The management and use of groundwater in a manner that can be maintained during the planning and implementation horizon without causing undesirable results.” Undesirable results include: chronic lowering of groundwater levels; significant and unreasonable reduction of groundwater storage; significant and unreasonable seawater intrusion, degraded water quality, and land subsidence; depletions of interconnected surface water that have significant and unreasonable adverse impacts on beneficial uses of the surface water. The SGMA exempts 388 basins categorized as low- and very-low priority, as well as all the adjudicated groundwater basins and 3 basins with pending groundwater adjudications. The SGMA was followed by the passage of Assembly Bill 1390 (AB 1390) and Senate Bill 226 (SB 226) in 2015 that provide some procedures for groundwater adjudications. In the adjudication of a groundwater basin, the court generally defines and determines water rights for all users and provides court-supervised basin management by a Watermaster, who is usually appointed by the court to ensure that the basin is managed in accordance with the court’s decree. Prior to adjudication, key stakeholders and users of the groundwater in a basin often negotiate a stipulation and physical solution to manage the basin, and the court can then accept it in whole or in part, or reject it and craft a different solution to manage the basin. There is limited analysis of the history and current condition of California’s adjudicated basins and the potential for future improvements to the adjudication process. This report for the State Water Resources Control Board (SWRCB) evaluates all of California’s adjudicated basins with respect to sustainable groundwater management as defined in SGMA including: accomplishments, challenges, how management can be improved, and whether there are common elements that result in the sustainable management of an adjudicated groundwater basin.

An Evaluation of Compensatory Mitigation Projects Permitted Under Clean Water Act Section 401 by the California State Water Resources Control Board, 1991-2002

California State Water Resources Control Board (SWRCB) | August 2nd, 2008

The purpose of this project, which was funded by the California State Water Resources Control Board (SWRCB), was to evaluate the compliance and wetland condition of compe

The purpose of this project, which was funded by the California State Water Resources Control Board (SWRCB), was to evaluate the compliance and wetland condition of compensatory wetland mitigation projects associated with Clean Water Act Section 401 Water Quality Certifications throughout California. This was done by selecting, reviewing and performing field evaluations for 143 permit files distributed across the 12 Water Board regions and sub-regions of the State. For each permit file we assessed the extent to which permittees complied with their mitigation conditions, including acreage requirements, whether the corresponding mitigation efforts resulted in optimal wetland condition, and if the habitat acreages gained through compensatory mitigation adequately replaced those lost through the permitted impacts. We found that permittees are largely following their permit conditions (although one-quarter to one-third of the time these are not met), but the resulting compensatory mitigation projects seldom result in wetlands with optimal condition.

An Evaluation of Juvenile Salmonid Routing and Barrier Effectiveness, Predation, and Predatory Fishes at the Head of Old River, 2009–2012

California Department of Water Resources (DWR) | February 2nd, 2015

The California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) manage the State Water Project (SWP) and Central Valley Project (CVP),

The California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) manage the State Water Project (SWP) and Central Valley Project (CVP), respectively, and are charged to do so in a manner that maintains the survival of anadromous salmonids subject to the terms of the National Marine Fisheries Service’s (NMFS) 2009 Biological Opinion (BO) and 2011 amendments regarding the Long-Term Central Valley Project and State Water Project Operations Criteria and Plan (OCAP). Action IV.1.3 of the NMFS’s 2009 BO instructs these agencies to “consider engineering solutions to further reduce diversion of emigrating juvenile salmonids to the interior and southern Delta, and reduce exposure to CVP and SWP export facilities.” Specifically, one objective of Action IV.1.3 is to “prevent emigrating salmonids from entering channels in the south Delta (e.g., Old River, Turner Cut) that increase entrainment risk to Central Valley steelhead migrating from the San Joaquin River through the Delta.”

An evolutionary parsimonious approach to estimate daily reference evapotranspiration

Nature Portfolio (Springer Nature) | March 20th, 2024

An Evolutionary Theory of Administrative Law

Southern Methodist University | May 25th, 2018

Law evolves to accommodate change—this is axiomatic in most academic legal traditions. But in the era of the administrative state, with congressional gridlock and a jud

Law evolves to accommodate change—this is axiomatic in most academic legal traditions. But in the era of the administrative state, with congressional gridlock and a judiciary hesitant to address policy questions, evolution of statutory law has become much more difficult. This leads to pent up demand for change in legal regimes. If the legislature and the courts cannot provide an outlet for this pressure, where does it go? How does the law continue to change? Although other scholars have looked to agencies as engines of legal change, we lack a theoretical framework to understand how that change happens. I argue that an evolutionary framework provides an informative framework for understanding administrative legal change. I provide three case studies that demonstrate the administrative evolution of the Endangered Species Act. In spite of tremendous advances in conservation, fundamental changes in scientists’ understanding of human impacts on the natural world, and increasingly strident clashes over private property rights and endangered species, the Act has remained largely unchanged for the last 35 years. In a functioning legislative system, the Act would have been amended to accommodate many of these changes. Instead, the case studies show a mechanism of legal change through agency action analogous to the mechanisms underlying biological evolution. Other commentators have argued the administrative state stymies evolution of the law, but this research contradicts that view. Applying an evolutionary framework to administrative actions creates a new theory of administrative evolution of the law, placing administrative analysis within the long tradition of evolutionary approaches to legal change used by commentators from Aristotle to Holmes. In contrast to traditional normative theories of administrative law, an evolutionary approach focuses on how change progresses over time. This theory of administrative evolution of the law also casts new light on a host of normative questions, from the role of judicial review to improvements in agency decision-making. Considering administrative actions within the broader context of the legal evolution promises a fruitful new approach to analyzing administrative law.

An extremeness threshold determines the regional response of floods to changes in rainfall extremes

Nature Portfolio (Springer Nature) | August 26th, 2021

Precipitation extremes will increase in a warming climate, but the response of flood magnitudes to heavier precipitation events is less clear. Historically, there is lit

Precipitation extremes will increase in a warming climate, but the response of flood magnitudes to heavier precipitation events is less clear. Historically, there is little evidence for systematic increases in flood magnitude despite observed increases in precipitation extremes. Here we investigate how flood magnitudes change in response to warming, using a large initial-condition ensemble of simulations with a single climate model, coupled to a hydrological model. The model chain was applied to historical (1961–2000) and warmer future (2060–2099) climate conditions for 78 watersheds in hydrological Bavaria, a region comprising the headwater catchments of the Inn, Danube and Main River, thus representing an area of expressed hydrological heterogeneity. For the majority of the catchments, we identify a ‘return interval threshold’ in the relationship between precipitation and flood increases: at return intervals above this threshold, further increases in extreme precipitation frequency and magnitude clearly yield increased flood magnitudes; below the threshold, flood magnitude is modulated by land surface processes. We suggest that this threshold behaviour can reconcile climatological and hydrological perspectives on changing flood risk in a warming climate.

An Implementation Blueprint for Enhancing Groundwater Recharge in the San Fernando Basin

University of Southern California (USC) | December 31st, 2008

The purpose of this report is to analyze the potential of providing ground water recharge in the San Fernando Basin (SFB) using native water, including the identification

The purpose of this report is to analyze the potential of providing ground water recharge in the San Fernando Basin (SFB) using native water, including the identification of strategic plans for the recharge project.

An Independent Scientific Assessment of Well Stimulation in California Volume II: Potential Environmental Impacts of Hydraulic Fracturing and Acid Stimulations

California Council on Science and Technology (CCST) | July 1st, 2015

In 2013, the California Legislature passed Senate Bill 4 (SB 4), setting the framework for regulation of well stimulation technologies in California, including hydraulic

In 2013, the California Legislature passed Senate Bill 4 (SB 4), setting the framework for regulation of well stimulation technologies in California, including hydraulic fracturing. SB 4 also requires the California Natural Resources Agency to conduct an independent scientific study of well stimulation technologies in California. SB 4 stipulates that the independent study assess current and potential future well stimulation practices, including the likelihood that these technologies could enable extensive new petroleum production in the state; evaluate the impacts of well stimulation technologies and the gaps in data that preclude this understanding; identify potential risks associated with current practices; and identify alternative practices that might limit these risks. (See Box 1.1-1 for a short history of oil and gas production in California.) This scientific assessment addresses well stimulation used in oil and gas production both on land and offshore in California.