Changes in global groundwater organic carbon driven by climate change and urbanization

Climate change and urbanization can increase pressures on groundwater resources, but little is known about how groundwater quality will change. Here, we use a global synthesis ( n  = 9,404) to reveal the drivers of dissolved organic carbon (DOC), which is an important component of water chemistry and substrate for microorganisms that control biogeochemical reactions. Dissolved inorganic chemistry, local climate and land use explained ~ 31% of observed variability in groundwater DOC, whilst aquifer age explained an additional 16%. We identify a 19% increase in DOC associated with urban land cover. We predict major groundwater DOC increases following changes in precipitation and temperature in key areas relying on groundwater. Climate change and conversion of natural or agricultural areas to urban areas will decrease groundwater quality and increase water treatment costs, compounding existing constraints on groundwater resources. Groundwater is Earth’s largest source of freshwater, but the cost and ease with which it is turned to drinking water is dependent on the concentration of organic carbon. Here the authors show that climate change and urbanization will likely elevate future levels of groundwater dissolved organic carbon across the globe.

[1]  U. Gunten,et al.  Ozonation of drinking water: part II. Disinfection and by-product formation in presence of bromide, iodide or chlorine. , 2003, Water research.

[2]  P. J. Chilton,et al.  Groundwater: the processes and global significance of aquifer degradation. , 2003, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[3]  Cumulative risk analysis of carcinogenic contaminants in United States drinking water , 2019, Heliyon.

[4]  Damien Sulla-Menashe,et al.  MODIS Collection 5 global land cover: Algorithm refinements and characterization of new datasets , 2010 .

[5]  E. Davidson,et al.  Temperature sensitivity of soil carbon decomposition and feedbacks to climate change , 2006, Nature.

[6]  Katherine Meierdiercks,et al.  The role of land surface versus drainage network characteristics in controlling water quality and quantity in a small urban watershed , 2017 .

[7]  M. Berg,et al.  Groundwater Arsenic Contamination Throughout China , 2013, Science.

[8]  R. Wetzel.  Gradient-dominated ecosystems: sources and regulatory functions of dissolved organic matter in freshwater ecosystems , 1992 .

[9]  A. Lawrence,et al.  Groundwater evolution beneath Hat Yai, a rapidly developing city in Thailand , 2000 .

[10]  B. Scanlon,et al.  Ground water and climate change , 2013 .

[11]  K. Seto,et al.  Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools , 2012, Proceedings of the National Academy of Sciences.

[12]  S. Goldberg.  Geochemistry, Groundwater and Pollution , 2006 .

[13]  G. Ozolins,et al.  WHO guidelines for drinking-water quality. , 1984, WHO chronicle.

[14]  Markus Bauer,et al.  Mobilization of arsenic by dissolved organic matter from iron oxides, soils and sediments. , 2006, The Science of the total environment.

[15]  P. Viet,et al.  Arsenic in groundwater of the Red River floodplain, Vietnam: Controlling geochemical processes and reactive transport modeling , 2007 .

[16]  L. Bounoua,et al.  A Method for Mapping Future Urbanization in the United States , 2018 .

[17]  E. Lipczynska-Kochany,et al.  Effect of climate change on humic substances and associated impacts on the quality of surface water and groundwater: A review. , 2018, The Science of the total environment.

[18]  J. L. Parra,et al.  Very high resolution interpolated climate surfaces for global land areas , 2005 .

[19]  S. Carpenter,et al.  Global Consequences of Land Use , 2005, Science.

[20]  D. Postma,et al.  In situ rates of sulfate reduction in an aquifer (Rømø, Denmark) and implications for the reactivity of organic matter , 1994 .

[21]  D. Bossio,et al.  Dissolved organic carbon and disinfection by-product precursor release from managed peat soils. , 2004, Journal of environmental quality.

[22]  M. Ando,et al.  Standards for Drinking Water Quality , 2004 .

[23]  A. Boyce,et al.  Tracing organic matter composition and distribution and its role on arsenic release in shallow Cambodian groundwaters , 2016 .

[24]  R. Sadiq,et al.  Disinfection by-products (DBPs) in drinking water and predictive models for their occurrence: a review. , 2004, The Science of the total environment.

[25]  D. Kleinbaum,et al.  Applied Regression Analysis and Other Multivariate Methods , 1978 .

[26]  M. Futter,et al.  Variability in organic carbon reactivity across lake residence time and trophic gradients , 2017 .

[27]  Kristen M. Hart,et al.  Somatic growth dynamics of West Atlantic hawksbill sea turtles: a spatio‐temporal perspective , 2016 .

[28]  N. Peters,et al.  Evaluation of High-Frequency Mean Streamwater Transit-Time Estimates Using Groundwater Age and Dissolved Silica Concentrations in a Small Forested Watershed , 2014, Aquatic Geochemistry.

[29]  D. Lapworth,et al.  Macronutrient status of UK groundwater: Nitrogen, phosphorus and organic carbon. , 2016, The Science of the total environment.

[30]  R. Wetzel.  Gradient-dominated ecosystems: sources and regulatory functions of dissolved organic matter in freshwater ecosystems , 1992, Hydrobiologia.

[31]  John P. Bloomfield,et al.  Pore-throat size distributions in Permo-Triassic sandstones from the United Kingdom and some implications for contaminant hydrogeology , 2001 .

[32]  U. Gunten.  Ozonation of drinking water: part II. Disinfection and by-product formation in presence of bromide, iodide or chlorine. , 2003 .

[33]  U. Schwertmann.  Inhibitory Effect of Soil Organic Matter on the Crystallization of Amorphous Ferric Hydroxide , 1966, Nature.

[34]  D. Lapworth,et al.  Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health , 2017, Hydrogeology Journal.

[35]  X. Álvarez‐Salgado,et al.  Dissolved organic carbon leaching from plastics stimulates microbial activity in the ocean , 2018, Nature Communications.

[36]  R. Harrington.  Part II , 2004 .

[37]  D. Jenkinson,et al.  Model estimates of CO2 emissions from soil in response to global warming , 1991, Nature.

[38]  Y. Fan,et al.  Global Patterns of Groundwater Table Depth , 2013, Science.

[39]  Peter A. Rogerson,et al.  A Statistical Method for the Detection of Geographic Clustering , 2010 .

[40]  R. C. Macridis.  A review , 1963 .

[41]  Andrea Richts,et al.  WHYMAP and the Groundwater Resources Map of the World 1:25,000,000 , 2011 .

[42]  Tigran Nikoghosyan,et al.  United Nations Children’s Fund (UNICEF) , 2018, Yearbook of International Cooperation on Environment and Development 1998–99.

[43]  G. Fogg,et al.  Dispersion of groundwater age in an alluvial aquifer system , 2002 .

[44]  T. Burt,et al.  Human impact on long‐term organic carbon export to rivers , 2017 .

[45]  P. Williams,et al.  Dissolved organic matter tracers reveal contrasting characteristics across high arsenic aquifers in Cambodia: A fluorescence spectroscopy study , 2019, Geoscience Frontiers.

[46]  Chris Freeman,et al.  An enzymic 'latch' on a global carbon store , 2001, Nature.

[47]  D. Saha,et al.  Role of shallow alluvial stratigraphy and Holocene geomorphology on groundwater arsenic contamination in the Middle Ganga Plain, India , 2015, Environmental Earth Sciences.

[48]  P. Smedley,et al.  Baseline groundwater chemistry in Scotland's aquifers , 2017 .

[49]  M. Schnitzer,et al.  EVIDENCE FOR INTERLAMELLAR ADSORPTION OF ORGANIC MATTER BY CLAY IN A PODZOL SOIL , 1971 .

[50]  M. Wilkins,et al.  Microbial Community Cohesion Mediates Community Turnover in Unperturbed Aquifers , 2018, mSystems.

[51]  J. Stoddard,et al.  Dissolved organic carbon trends resulting from changes in atmospheric deposition chemistry , 2007, Nature.

[52]  P. Bradley,et al.  Assessing the Relative Bioavailability of DOC in Regional Groundwater Systems , 2012, Ground water.

[53]  D. Monteith,et al.  Export of organic carbon from peat soils , 2001, Nature.

[54]  Yun-Hwei Shen.  Sorption of natural dissolved organic matter on soil , 1999 .

[55]  Michael O. Rivett,et al.  Nitrate occurrence and attenuation in the major aquifers of England and Wales , 2007, Quarterly Journal of Engineering Geology and Hydrogeology.

[56]  F. Landerer,et al.  Emerging trends in global freshwater availability , 2018, Nature.

[57]  Charles F. Harvey,et al.  Arsenic Mobility and Groundwater Extraction in Bangladesh , 2002, Science.

[58]  M. Helmers,et al.  Effects of native perennial vegetation buffer strips on dissolved organic carbon in surface runoff from an agricultural landscape , 2014, Biogeochemistry.

[59]  B. Morris,et al.  Tracing groundwater flow and sources of organic carbon in sandstone aquifers using fluorescence properties of dissolved organic matter (DOM) , 2008 .

[60]  Carl Richards,et al.  Landscape influences on water chemistry in Midwestern stream ecosystems , 1997 .

[61]  Approaches to stream solute load estimation for solutes with varying dynamics from five diverse small watersheds , 2016 .

[62]  C. Tucker,et al.  Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999 , 2003, Science.

[63]  G. Kling,et al.  Variation in dissolved organic matter controls bacterial production and community composition. , 2006, Ecology.

[64]  A. Boyce,et al.  Dual in-aquifer and near surface processes drive arsenic mobilization in Cambodian groundwaters. , 2019, The Science of the total environment.

[65]  A. Utton.  The Development of International Groundwater Law , 1982 .