Jason J. Gurdak

Vulnerability of Recently Recharged Groundwater in Principle Aquifers of the United States To Nitrate Contamination

Recently recharged water (defined here as <60 years old) is generally the most vulnerable part of a groundwater resource to nonpoint-source nitrate contamination. Understanding at the appropriate scale the interactions of natural and anthropogenic controlling factors that influence nitrate occurrence in recently recharged groundwater is critical to support best management and policy decisions that are often made at the aquifer to subaquifer scale. New logistic regression models were developed using data from the U.S. Geological Surveys National Water-Quality Assessment (NAWQA) program and National Water Information System for 17 principal aquifers of the U.S. to identify important source, transport, and attenuation factors that control nonpoint source nitrate concentrations greater than relative background levels in recently recharged groundwater and were used to predict the probability of detecting elevated nitrate in areas beyond the sampling network. Results indicate that dissolved oxygen, crops and irrigated cropland, fertilizer application, seasonally high water table, and soil properties that affect infiltration and denitrification are among the most important factors in predicting elevated nitrate concentrations. Important differences in controlling factors and spatial predictions were identified in the principal aquifer and national-scale models and support the conclusion that similar spatial scales are needed between informed groundwater management and model development.

Optimizing the Water‐Energy‐Food Nexus in the Asia‐Pacific Ring of Fire

Climate change and economic development are causing increased pressure on global water, energy, and food resources, presenting increased levels of trade-offs and conflicts among these resources and stakeholders. Because these resources are interconnected, policy development and resource management require careful consideration of the complex interconnections between nature and society. A balance between risk and resilience is critical for achieving human and environmental security, particularly in Asia’s region within the “Ring of Fire,” which is experiencing drastic social change alongside the huge potential risks and benefits associated with development. The 2011 Fukushima nuclear accident and aftermath underscore the importance of developing policy and management options that maximize security and minimize risk within the waterenergyfood (WEF) nexus. More than 50 scientists from the United States, Canada, Indonesia, the Philippines, and Japan gathered at the Research Institute for Humanity and Nature (RIHN) in Kyoto, Japan, to discuss the WEF nexus within these Ring of Fire countries. This inaugural workshop coincided with the launch of RIHN’s new 5-year project, HumanEnvironmental Security in the AsiaPacific Ring of Fire: WEF Nexus. The outcomes of the workshop will help address the question of how communities can maximize humanenvironmental security by choosing policies and management structures that optimize the WEF nexus. Participants presented countryspecific conflicts and trade-offs in the WEF nexus; a common recommendation was that stakeholders would benefit from a decisionmaking process that is informed early by science. For example, in Japan, conflict resolution between geothermal power generation and hot spring businesses that tap a shared but limited geothermal resource requires an evaluation of socialeconomicenvironmental trade-offs. Common research questions emerged from the presentations and discussions: How can we best manage the trade-offs between nexuses? What is the role of stakeholders in trade-offs and environmental security? What factors determine the optimal governance structure for environmental security? What general lessons can be drawn from each country and the AsiaPacific region? Participants discussed how studies can be designed to best meet countryspecific objectives and allow for intercomparison. The consensus was a risk-based framework, which allows for stressors and impacts to be evaluated using a place-based risk assessment. To enable intercomparison, a common set of risk and resilience indicators was proposed, and approaches for evaluating these indicators will be codeveloped as the project progresses. Finally, the participants discussed and recommended four interdisciplinary approaches: environmental governance, science in/for society, and codesign/ coproduction ap-proaches; biophysical measurements/ analyses using geochemical, coastal oceanographic, geophysical, satellite, hydrological, and ecological techniques; social measurements/ analyses using community surveys, costbenefit/ efficiency analysis, and environmental valuation from socioeconomic, anthropology, psychology, and behavior science method-ologies; and development of integrated indicators/ indices and network analyses of feedback from stakeholder meeting/ workshops. Aiko Endo (RIHN), Fernando Siringan (University of the Philippines), Robert Delinom (Indonesian Institute of Sciences), and other project members are acknowledged. The second WEF nexus workshop will be held in San Francisco, Calif., in December 2014.

Catalyzing frontiers in water-climate-society research: A view from early career scientists and junior faculty

AMEriCAN METEOrOlOGiCAl SOCiETY | 477 AffiliAtions: McNeeley, TesseNdorf, aNd lazrus—NCAR, Boulder, Colorado; lazrus—University of Oklahoma, Norman, Oklahoma; Heikkila—University of Colorado, Denver, Colorado; fergusoN—Colorado School of Mines, Golden, Colorado; arrigo—East Carolina University, Greenville, North Carolina; aTTari—Columbia University, New York, New York; ciaNfraNi— Hampshire College, Amherst, Massachusetts; dilliNg aNd kircHoff—University of Colorado, Boulder, Colorado; gurdak— San Francisco State University, San Francisco, California; kaMpf—Colorado State University, Fort Collins, Colorado; kauNeckis—University of Nevada, Reno, Nevada; lee—San Jose State University, San Jose, California; liNTNer—Rutgers, The State University of New Jersey, New Brunswick, New Jersey; MaHoNey—UCAR, Boulder, Colorado; opiTz-sTapleToN— Institute for Social and Environmental Transition, Boulder, Colorado; ray—University of Hawaii at Manoa, Honolulu, Hawaii; souTH—University of Exeter, Exeter, United Kingdom; sTubblefield—Humboldt State University, Arcata, California; brugger—University of California—Davis, Davis, California CoRREsPonDinG AUtHoR: Shannon M. McNeeley, Advanced Study Program, Research Applications Laboratory/Integrated Science Program, NCAR, P.O. Box 3000, Boulder, CO 80307 E-mail: smcneele@ucar.edu

The Water-Energy-Food Nexus and California’s Sustainable Groundwater Management Act

Water, energy, and food are among the most critically important resources for society. The demand for these resources is likely to increase in the coming decades because of global population growth, climate change, and other socioeconomic forces. This chapter provides a brief outline of some potential impacts and feedbacks of how Water-Energy-Food (WEF) Nexus concepts may help local managers and stakeholders in California, USA design optimal groundwater sustainability plans to best meet the diverse interests in groundwater resources while implementing the State’s new (2014) Sustainable Groundwater Management Act (SGMA) law. Sustainable groundwater resources will in turn likely increase the resilience of the WEF Nexus across California.

Assessment of the impacts of climate variability on total water storage across Africa: implications for groundwater resources management

The links between climate variability, depicted by time series of oceanic indices, and changes in total water and groundwater storage are investigated across nine large aquifer basins of the African continent. The Gravity Recovery and Climate Experiment (GRACE) mission’s observations represent a remarkable tool that can provide insight into the dynamics of terrestrial hydrology in areas where direct in situ observations are limited. In order to evaluate the impact of interannual and multidecadal climate variability on groundwater resources, this study assesses the relationship between synoptic controls on climate and total water storage estimates from (i) GRACE from 2002 to 2013 and (ii) a two-variable climate-driven model that is able to reconstruct past storage changes from 1982 to 2011. The estimates are then compared to time series of groundwater levels to show the extent to which total water storage covaries with groundwater storage. Results indicate that rainfall patterns associated with the El Niño Southern Oscillation (ENSO) are the main driver of changes in interannual groundwater storage, whereas the Atlantic MultiDecadal Oscillation (AMO) plays a significant role in decadal to multidecadal variability. The combined effect of ENSO and AMO could trigger significant changes in recharge to the aquifers and groundwater storage, in particular in the Sahel. These findings could help decision-makers prepare more effective climate-change adaptation plans at both national and transboundary levels.RésuméLes liens entre la variabilité climatique, représentés par des séries chronologiques d’indices océaniques, et les changements de volumes d’eau total et d’eaux souterraines stockés (réserves d’eau) sont étudiées au niveau de neuf grands bassins aquifères du continent africain. Les observations de la mission Gravity Recovery and Climate Experiment (GRACE) constituent un outil remarquable, susceptible d’approfondir les connaissances sur la dynamique de l’hydrologie superficielle dans les secteurs où les observations de terrain sont limitées. Afin d’évaluer l’impact de la variabilité interannuelle et multidécennale du climat sur les ressources en eau souterraine, cette étude évalue la relation entre le climat et les estimations de volume total des réserves en eau, à partir (i) des données graphiques de GRACE de 2002 à 2013 et (II) des données graphiques des résultats d’un modèle à deux variables assujetti sur le climat susceptible de reconstituer les évolutions passées des réserves entre 1982 et 2011. Les estimations sont ensuite comparées aux chroniques des niveaux piézométriques afin de montrer dans quelle mesure les réserves en eau totales varient avec les réserves en eau souterraine. Les résultats indiquent que le comportement des précipitations associé à l’oscillation australe – El Niño (ENSO) contrôle les modifications interannuelles des réserves en eaux souterraines, alors que l’oscillation multidécennale atlantique (AMO) joue un rôle significatif dans la variabilité décennale à multidécennale. Les effets combinés d’ENSO et d’AMO peuvent provoquer des modifications notables de la recharge des aquifères et des réserves en eau souterraine, en particulier dans le Sahel. Ces résultats pourraient aider les décideurs à préparer des plans d’adaptation au changement climatique plus efficaces, tant au niveau national que transfrontalier.ResumenLas relaciones entre la variabilidad climática, representada por series de tiempo de índices oceánicos, y los cambios en el almacenamiento total de agua y agua subterránea se investigan en nueve grandes cuencas de acuíferos del continente africano. Las observaciones de la misión Gravity Recovery and Climate Experiment (GRACE) representan una herramienta notable que puede proporcionar información sobre la dinámica de la hidrología terrestre en áreas donde las observaciones directas in situ son limitadas. Con el fin de evaluar el impacto de la variabilidad climática interanual y multidecadal en los recursos de agua subterránea, este estudio evalúa la relación entre los controles sinópticos sobre el clima y las estimaciones de almacenamiento total de agua de (i) GRACE de 2002 a 2013 y (ii) un modelo de dos variables forzado por el clima que es capaz de reconstruir los cambios de almacenamiento pasados desde 1982 hasta 2011. Las estimaciones se comparan con series temporales de niveles de agua subterránea para mostrar el grado en que el almacenamiento total de agua covaría con el almacenamiento de agua subterránea. Los resultados indican que los patrones de lluvia asociados con la Oscilación Austral de El Niño (ENSO) son el principal impulsor de los cambios interanuales de almacenamiento del agua subterránea, mientras que la Oscilación Multidecadal del Atlántico (AMO) desempeña un papel significativo en la variabilidad decadal a multidecadal. El efecto combinado de ENSO y AMO podría desencadenar cambios significativos en la recarga de los acuíferos y el almacenamiento de agua subterránea, en particular en el Sahel. Estos hallazgos podrían ayudar a los responsables de la toma de decisiones a preparar planes de adaptación al cambio climático más efectivos tanto a nivel nacional como transfronterizo.摘要调查研究了非洲大陆9个大型含水层盆地由海洋指数时间序列描述的气候变化与整个水储量和地下水储量变化之间的联系。重力恢复和气候试验项目观测结果展示了在直接现场观测受限的地区可以深入了解陆地水文动力学的一种卓越的工具。为了评估年际和数个十年间的气候变化对地下水资源的影响,本研究评价了天气对气候的控制因素和整个出水量估算值之间的相互关系,出水量估算值是2002年到2013年通过重力恢复和气候试验以及1982年到2011年通过能够重建过去储量变化的二变量气候驱使模型得到的。然后估算值与地下水水位的时间序列对比,显示出整个水储量与地下水储量的共变程度。结果表明,与厄尔尼诺南振荡相关的降雨模式是年际地下水储量变化的主要驱动力,而大西洋数十年振荡在十年间到数十年间变化中发挥着重要作用。厄尔尼诺南振荡和大西洋数十年振荡的综合影响可触发含水层补给量和地下水储量发生重大变化,特别是在萨赫勒地带。这些发现有助于决策者在国家和跨界层面上制定更有效的气候变化适应规划。ResumoOs elos entre variabilidade climática, ilustradas por series temporais de índices oceânicos, e alterações no armazenamento de agua total e subterrânea são estudados em nove bacias aquíferas do continente Africano. As observações da missão GRACE (Gravity Recovery and Climate Experiment) representam uma ferramenta notável que permite compreender as dinâmicas da hidrologia terrestre em áreas onde observações diretas são limitadas. De forma a avaliar o impacto da variabilidade climática interanual e multidecadal nos recursos hídricos subterrâneos, este estudo avalia a relação entre controles sinóticos sobre o clima e estimativas do armazenamento total de agua a partir de (i) GRACE de 2002 a 2013 e (ii) um modelo de duas variáveis derivadas do clima capaz de reconstruir as alterações de armazenamento de 1982 a 2011. As estimativas são subsequentemente comparadas com as series temporais de níveis de aguas subterrâneas de forma a demonstrar o quanto o armazenamento total de agua covaria com o armazenamento de águas subterrâneas. Resultados indicam que os padrões de precipitação associados com El Nino Oscilação Sul (ENOS) são os impulsionadores principais da variação interanual de armazenamento das águas subterrâneas, enquanto que a Oscilação Multidecadal do Atlântico (OMA) tem um papel importante na variabilidade multidecadal. O efeito conjunto do ENOS e OMA poderá desencadear mudanças significativas na recarga dos aquíferos e no armazenamento de águas subterrâneas, em particular no Sahel. Estes resultados podem ajudar decisores a preparar planos para adaptação as mudanças climáticas a nível nacional e transfronteiriço mais efetivos.

Topical Collection: Climate-change research by early-career hydrogeologists

Scientific outreach, international networking, collaboration and adequate courses are needed in both developed and developing countries to enable early-career hydrogeologists to promote long-term multidisciplinary approaches to cope with climate-change issues and emphasize the importance of groundwater in a global strategy for adaptation. One such collaboration has involved the Early Career Hydrogeologists’ Network of the International Association of Hydrogeologists (ECHN-IAH) and the UNESCO International Hydrological Programme’s (IHP) Groundwater Resources Assessment under the Pressures of Humanity and Climate Changes (GRAPHIC) project. This collaboration seeks to foster the education and involvement of the future generation of water leaders in the debate over groundwater and climate change.RésuméLe rayonnement scientifique, le réseautage international, la collaboration et des cursus de formation adéquats sont nécessaires dans les pays développés et en développement permettre aux hydrogéologues en début de carrière de promouvoir des approches multidisciplinaires à long terme pour faire face aux questions de changement climatique et insister sur l’importance des eaux souterraines dans une stratégie globale d’adaptation. L’une de ces collaborations a impliqué le réseau des hydrogéologues en début de carrière de l’association internationale des hydrogéologues (RHDC-AIH) et le projet d’évaluation des ressources en eau souterraine sous contraintes de l’humanité et des changements climatiques (GRAPHIC) du programme hydrologique international de l’UNESCO (PHI). Cette collaboration vise à favoriser l’éducation et la participation de la génération future des leaders du domaine de l’eau dans le débat concernant les eaux souterraines et le changement climatique.ResumenLa divulgación científica, la creación de redes internacionales, la colaboración y cursos adecuados son necesarios tanto en países desarrollados como en desarrollo para permitir a los hidrogeólogos jóvenes a promover enfoques multidisciplinarios a largo plazo para hacer frente a los problemas del cambio climático y enfatizar la importancia del agua subterránea en una estrategia global de adaptación. Una de estas colaboraciones ha sido la Early Career Hydrogeologists’ Network de la Asociación Internacional de Hidrogeólogos (ECHN-IAH) y el proyecto Pressures of Humanity and Climate Changes (GRAPHIC) de la UNESCO International Hydrological Programme’s (IHP) Groundwater Resources Assessment. Esta colaboración busca fomentar la educación y la participación de la futura generación de líderes del agua en el debate sobre las aguas subterráneas y el cambio climático.摘要发达国家和发展中国家需要科学上的延伸、国际网络化、合作及充足的课程,使青年水文地质学家能够促进长期多学科方法应对气候变化问题,在全球适应战略中强调地下水的重要性。一项这样的合作涉及国际水文地质学家协会青年水文地质学家网络及联合国教科文组织的人类和气候变化压力下水文计划地下水资源评价项目。这项合作寻求地下水和气候变化争论中有关未来一代水领导的教育和参与问题。RiassuntoDivulgazione scientifica, networking internazionale, collaborazione e corsi di formazione sono elementi necessari, sia nei paesi avanzati che in quelli in via di sviluppo, per premettere ai giovani idrogeologi di promuovere ricerche multidisciplinari volte ad affrontare le emergenze associate ai cambiamenti climatici e ad enfatizzare l’importanza delle acque sotterranee nelle strategie di adattamento globale. Una collaborazione di questo tipo ha coinvolto l’Early Career Hydrogeologists’ Network della Associazione Internazionale di Idrogeologia (ECHN-IAH) e il gruppo “Valutazione delle risorse idriche sotterranee sotto le pressioni dell’umanità e cambiamenti climatici” (Groundwater Resources Assessment under the Pressures of Humanity and Climate Changes - GRAPHIC) del Programma Idrogeologico Internazionale (IHP) dell’UNESCO (UNESCO-IHP). Questa collaborazione mira a promuovere l’educazione e il coinvolgimento della futura generazione di leader dell’acqua nel dibattito sulle acque sotterranee e sui cambiamenti climatici.ResumoDivulgação científica, trabalhos em redes internacionais, colaboração e cursos adequados são necessários tanto nos países desenvolvidos como nos países em desenvolvimento para permitir que os hidrogeólogos em início de carreira promovam abordagens multidisciplinares de longo prazo para lidar com questões de mudança climática e enfatizem a importância das águas subterrâneas em uma estratégia global de adaptação. Uma dessas colaborações envolveu a Rede de Hidrogeólogos em início de carreira da Associação Internacional de Hidrogeólogos (ECHN-IAH) e o Programa Hidrológico Internacional da UNESCO (IHP) com o projeto sobre Avaliação dos Recursos Hídricos Subterrâneos sob Pressões da Humanidade e Mudanças Climáticas (GRAPHIC). Esta colaboração busca promover a educação e o envolvimento da geração futura de líderes da água no debate sobre as águas subterrâneas e as mudanças climáticas.