Mapping river recharge rates with stable isotopes and tritium-helium groundwater ages

<p>While climate change will challenge the future of California’s water resources, groundwater can buffer variability in precipitation and streamflow, if managed sustainably. Enhanced river recharge is an important tool to reach sustainable groundwater management in the California Central Valley (USA). Understanding and predicting recharge rates of river water, either natural river bank infiltration or managed aquifer recharge (MAR) during floods (Flood-MAR) or on agricultural land (Ag-MAR) is essential to evaluate the sustainability of groundwater management plans. Groundwater ages, combined with other isotopic and noble gas evidence, can elucidate surface water-groundwater interactions and support river recharge rates calculations over longer time periods.</p><p>Our study is focused on the recharge from the Cosumnes River in the California Central Valley. The Cosumnes River forms the boundary between the Sacramento Valley groundwater basin to the north and the San Joaquin Valley groundwater basin to the south. For this study, 28 new samples were collected for the analysis of 3H/3He age, noble gases, and stable isotopes. 25 additional samples from the California Waterboards Groundwater Ambient Monitoring and Assessment (GAMA) Shallow Aquifer Assessment program were included, which were collected and analyzed by the USGS California Water Science Center in 2017.</p><p>We find that 28% of groundwater in the San Joaquin – Cosumnes groundwater subbasin originated as river water recharge, based on the interpolated mean δ<sup>18</sup>O (7.7 ‰ ), compared with river water (-9 ‰) and local precipitation recharge (-7 ‰) end-members. River water is a source of modern recharge, resulting in high tritium concentrations close to the Cosumnes River. In contrast, ambient groundwater from local precipitation recharge is predominantly pre-modern or fossil, containing less than 1 pCi/L tritium. Combining groundwater ages with the distance to the river, aquifer thickness, and porosity, estimates of river water recharge rate vary between 0.02 km<sup>3</sup>/yr and 0.035 km<sup>3</sup>/yr. These quantitative estimates of river water recharge will constrain the numerical groundwater flow model for this basin and aid groundwater managers in developing sustainability plans to balance groundwater pumping with recharge rates.</p>

Reviewer Acknowledgements

International Journal of Social Science Studies (IJSSS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether IJSSS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 8, Number 2Amin Ali Almubar, University of El Imam Al mahdi, SudanAna Uka, Beder University, AlbaniaAnastasia Panagakos, Cosumnes River College, USAAntónio Calha, Polytechnic Institute of Portalegre, PortugalBassam Yousef Ibrahim Banat, Al-Quds University, PalestineEnzo Loner, University of Trento, ItalyFernando Aragón-Durand, National Autonomous University of Mexico, MexicoJesster Pasule Eduardo, Nueva Ecija University of Science and Technology, PhilippinesJuanita GOICOVICI, University Babeș-Bolyai of Cluj-Napoca, RomaniaKatja Eman, Univerza v Mariboru, SloveniaMei-Ling Lin, National Open University, TaiwanRonaldo R. Larioque, NUEVA ECIJA UNIVERSITY OF SCIENCE AND TECHNOLOGY, PhilippinesXian-Liang Tian, Zhongnan University of Economics and Law, China

Reviewer Acknowledgements

International Journal of Social Science Studies (IJSSS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether IJSSS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 6, Number 2 Agboola O. Paul, Universiti Teknologi Malaysia, MalaysiaAhmet Yıkmış, Abant Izzet Baysal Univeersity, TurkeyAmany Albert, Beni-Suef University, EgyptAnastasia Panagakos, Cosumnes River College, USAAntónio Calha, Polytechnic Institute of Portalegre, PortugalBo Li, St Ambrose University, USAE.Ozan Aksoz, Anadolu University, TurkeyJehu Onyekwere Nnaji, University of Naples II, Italy and Globe Visions Network Italy, ItalyJohn Boulard Forkuor , Kwame Nkrumah University of Science and Technology (KNUST) , GhanaJulia M. Mack, Gannon University, USAMohammad Naji Shah Mohammadi, Kuala Lumpur, MalaysiaQingzhi Huan, Peking University, ChinaRasa Poceviciene, Siauliai University, LithuaniaRemigiusz Kijak, "University of Warsaw", PolandSandro Serpa, University of the Azores, PortugalShariq aziz butt, Superior University Lahore, PakistanValentina Evangelista, G. d’Annunzio University, ItalyXian-Liang Tian, Zhongnan University of Economics and Law, ChinaYanzhe Zhang, Jilin University, China, China/Australia

Reviewer Acknowledgements

International Journal of Social Science Studies (IJSSS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether IJSSS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 6, Number 1 Agboola O. Paul, Universiti Teknologi Malaysia, MalaysiaAmanda ElBassiouny, Spring Hill College, USAAnastasia Panagakos, Cosumnes River College, USAAntónio Calha, Polytechnic Institute of Portalegre, PortugalGhazali Bello Abubakar, Sokoto State University, NigeriaHyejin Lee, Tufts University, MA, USA and Konkuk University, Seoul, South Korea, USAJadranka Svarc, Institute of Social Sciences Ivo Pilar, Zagreb, CroatiaJamie Spinney, Saint Mary’s University, CanadaJehu Onyekwere Nnaji, University of Naples II, Italy and Globe Visions Network Italy, ItalyJulia M. Mack, Gannon University, USAMickey Langlais, University of Nebraska – Kearney, USAMohammad Naji Shah Mohammadi, Kuala Lumpur, MalaysiaShun - Jen Hsiao, University of Washington, USATimbre Wulf-Ludden, University of Nebraska at Kearney, USA

Reviewer Acknowledgements

International Journal of Social Science Studies (IJSSS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether IJSSS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 5, Number 6 Amanda ElBassiouny, Spring Hill College, USAAnastasia Panagakos, Cosumnes River College, USAAyşegül Sili Kalem, Necmettin Erbakan Universitesi, TurkeyCaroline Schmitt, Johannes Gutenberg University Mainz, GermanyEmanuele Achino, C. D. T. O., ItalyImran Ali Sandano, Zhejiang University, ChinaJianquan Cheng, Manchester Metropolitan University, UKJosé María Fernandez-Crehuet, Universidad Politecnica de Madrid, SpainJulia M. Mack, Gannon University, USAK.O. Aramide, The Polytechnic Ibadan, NigeriaKatja Eman, Univerza v Mariboru, SloveniaLaura Diaconu Maxim, "Alexandru Ioan Cuza University" of Iasi, RomaniaRachita Shrivastava Roy, Department of Higher Education,Chhatisgarh-India, IndiaYanzhe Zhang, Jilin University, ChinaZlatan Begić, University of Tuzla, Bosnia and Herzegovina

Reviewer Acknowledgements

International Journal of Social Science Studies (IJSSS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether IJSSS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 5, Number 2 Abdul Azim Akhtar, Institute of Objective Studies, IndiaAgboola O. Paul, Universiti Teknologi Malaysia, MalaysiaAnastasia Panagakos, Cosumnes River College, USAAntónio Calha, Polytechnic Institute of Portalegre, PortugalBegoña Montero-Fleta, Universitat Politécnica de València, SpainE.Ozan Aksoz, Anadolu University, TurkeyEmanuele Achino, C. D. T. O., ItalyHenry Poduthas, West Texas A&M University, USAJehu Onyekwere Nnaji, University of Naples II, Italy and Globe Visions Network, ItalyK. O. Aramide, The Polytechnic Ibadan, NigeriaKatja Eman, Univerza v Mariboru, SloveniaLaura Diaconu Maxim, "Alexandru Ioan Cuza University" of Iasi, RomaniaLuigia Simona Sica, University of Naples “Federico II”, ItalyMałgorzata Haładewicz, Opole University of Technology, PolandRasa Poceviciene, Siauliai University, LithuaniaRaymond Chan, City University of Hong Kong, Hong KongSandro Serpa, University of the Azores, Portugal James YoungEditorial AssistantOn behalf of,The Editorial Board of International Journal of Social Science StudiesRedfame Publishing9450 SW Gemini Dr. #99416Beaverton, OR 97008, USAURL: http://ijsss.redfame.com