1st Edition

Geochemical Processes, Weathering and Groundwater Recharge in Catchments

By O.M. Saether, P. de Caritat Copyright 1996

    Geochemical Processes, Weathering and Groundwater Recharge in Catchments is a specialist book concerned with the natural processes taking place where water interacts with minerals and organic matter at the earth’s surface, in soils or within aquifers. It focuses on the all important interface between the hydrological and geochemical cycles in terrestrial ecosystems, and is thus particularly relevant to understanding the environment. The book is intended primarily as a reference text for graduate students in Earth Sciences, Hydrology or Environmental Sciences, but will be a useful introduction to those studying Chemistry, Biology or Forestry Studies. Geochemical Processes, Weathering and Groundwater Recharge in Catchments presents an overview of the current status of knowledge of catchment studies, with an outline of the challenges of future research.

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    PREFACE -- PARTI: CATCHMENT PROCESSES -- 1 WEATHERING PROCESSES James I. Drever -- 1.1 Definitions of weathering -- 1.2 Types of weathering reaction -- 1.2.1 Congruent dissolution -- 1.2.2 Incongruent dissolution -- 1.3 Cation exchange -- 1.4 Mineral dissolution kinetics -- 1.4.1 Relative rates -- 1.4.2 Effects of solution composition on dissolution rates of silicate minerals -- 1.5 Comparisons between field and laboratory dissolution rates -- 1.6 Modeling approaches -- 1.7 Future research directions References -- 2 COMPOSITION, PROPERTIES AND DEVELOPMENT OF NORDIC SOILS Ole K Borggaard -- 2.1 Introduction -- 2.2 Soil composition -- 2.2.1 Soil air -- 2.2.2 Soil water -- 2.2.3 Soil organic matter (SOM) -- 2.2.4 Soil minerals -- 2.3 Soil properties -- 2.3.1 Physical properties -- 2.3.2 Chemical properties -- 2.4 Soil development processes -- 2.4.1 Decalcification -- 2.4.2 Gleization -- 2.4.3 Lessivage (clay migration) -- 2.4.4 Podzolization -- 2.5 Summary with conclusions -- 2.6 Future research directions -- Appendix A: Definition, terminology, horizons and description of soil -- Appendix B: Classification -- Acknowledgement -- References -- 3 CATCHMENT HYDROLOGY Allan Rodhe & Anund Killingtveit -- 3.1 Introduction -- 3.2 The catchment -- 3.3 Water balance -- 3.4 Runoff processes in the catchment -- 3.5 Soil water storage and flow processes -- 3.6 Mathematical modelling of soil water movement -- 3.6.1 Soil water potential -- 3.6.2 Water flow - Darcy’s law -- 3.6.3 Drainage equilibrium -- 3.7 Groundwater storage and flow -- 3.7.1 Aquifers and aquitards -- 3.7.2 Storage coefficient -- 3.7.3 Groundwater flow -- 3.7.4 Flow velocity -- 3.7.5 Preferential flowpaths - macropore flow -- 3.8 Streamflow generation -- 3.8.1 Hortonian overland flow -- 3.8.2 Variable source area -- 3.8.3 Recharge and discharge areas -- 3.8.4 Groundwater contribution in discharge areas -- 3.9 The role of topography -- 3.10 The HBV-model: A precipitation /runoff-model -- 3.10.1 The snow routine -- 3.10.2 The soil moisture routine -- 3.10.3 The runoff response routine -- 3.11 Model calibration and use -- 3.12 Components of the water budget in the Nordic countries References -- 4 GROUNDWATER RECHARGE David N Lemer -- 4.1 What is recharge? -- 4.1.1 Recharge and related concepts -- 4.1.2 Recharge in the hydrological cycle -- 4.1.3 Objectives of chapter -- 4.2 Hydrogeological environments -- 4.2.1 Introduction -- 4.2.2 Permo-Triassic sandstone of the UK -- 4.2.3 Scandinavian conditions -- 4.3 Precipitation recharge -- 4.3.1 Introduction -- 4.3.2 Lysimeters: Direct measurement -- 4.3.3 Empirical methods -- 4.3.4 Soil moisture budgeting method -- 4.3.5 Darcian approaches -- 4.3.6 Tracer techniques -- 4.3.7 Variability of recharge across catchments -- 4.3.8 Localised recharge -- 4.4 Recharge from rivers -- 4.4.1 River types -- 4.4.2 Rivers in contact with the water table -- 4.4.3 River recharge estimation methods -- 4.4.4 Groundwater response under ephemeral rivers -- 4.4.5 Water balances -- 4.4.6 Darcian approaches -- 4.4.7 Tracer techniques for groundwater recharge from river -- 4.5 Interaquifer flows -- 4.6 Net recharge over a region -- 4.6.1 Introduction -- 4.6.2 Water table rise -- 4.6.3 Hydrograph analysis for groundwater discharge -- 4.6.4 Inverse techniques -- 4.6.5 Aquifer-wide tracers -- 4.7 Concluding remarks -- References -- PART 2: TECHNIQUES FOR CATCHMENT STUDIES -- 5 CHEMICAL ANALYSIS OF ROCKS AND SOILS -- Magne 0degard -- 5.1 Introduction -- 5.2 Historical development -- 5.3 Total analysis versus partial analysis -- 5.4 Analytical methods -- 5.4.1 X-ray fluorescence (XRF) -- 5.4.2 Inductively coupled plasma atomic emission spectrometry (ICP-AES) -- 5.4.3 Atomic absorption spectrometry (AAS) -- 5.5 Quality control -- References -- 6 COLLECTION AND ANALYSIS OF GROUNDWATER SAMPLES John Mather -- 6.1 Introduction -- 6.2 Data quality -- 6.3 Sample collection and analysis -- 6.3.1 Field parameters -- 6.3.2 Laboratory measurements -- 6.3.3 Pore water analysis -- 6.4 Representation of data -- 6.5 Water quality standards -- Appendix A: Prescribed concentrations or values specified in the UK Water -- Supply (Water Quality) regulations 1989 -- References -- 7 ENVIRONMENTAL ISOTOPES AS TRACERS IN CATCHMENTS Sylvi Haldorsen, Gunnhild Riise, Berit Swensen & Ronald S. Sletten -- 7.1 Introduction -- 7.1.1 Environmental isotopes -- 7.1.2 The use of environmental isotopes in small catchments -- 7.2 Oxygen and hydrogen isotopes -- 7.2.1 Stable isotopes: 180 and 2H(D) -- 7.2.2 Application of 8180 and 8D in catchment studies -- 7.2.3 Tritium -- 7.3 Carbon isotopes -- 7.3.1 The 14C isotope -- 7.3.2 The 13C isotope -- 7.4 Nitrogen isotopes -- 7.4.1 Nitrogen isotope variations in precipitation -- 7.4.2 S15N of NO3 in the pedosphere and groundwater -- 7.4.3 Pollution studies in catchments and groundwater aquifers -- 7.5 Sulphur isotopes -- 7.5.1 Some examples of sulphur isotopes studies -- 7.6 Conclusions Acknowledgements References -- 8 FIELD INSTRUMENTATION -- Anund Killingtveit, Knut Sand & Nils Roar Scelthun -- 8.1 Streamflow measurements -- 8.1.1 Introduction -- 8.1.2 Measurement of stage -- 8.1.3 Discharge measurement methods -- 8.1.4 Stage-discharge relation -- 8.1.5 Practical considerations -- 8.2 Automatic data acquisition systems in hydrology -- 8.2.1 Introduction -- 8.2.2 Main structure and system components -- 9 CATCHMENT MASS BALANCE James I. Drever -- 9.1 Introduction -- 9.2 Terms in the mass balance equation -- 9.2.1 Solutes in outflow -- 9.2.2 Solutes from the atmosphere -- 9.2.3 Changes in the exchange pool -- 9.2.4 Changes in the biomass -- 9.2.5 Chemical weathering -- 9.3 Mass balance and mineral weathering -- 9.3.1 The Sierra Nevada, California, USA -- 9.3.2 Absaroka mountains, Wyoming, USA -- 9.3.3 Adirondack mountains, New York, USA -- 9.3.4 Sogndal, Norway -- 9.4 The problem of excess calcium -- 9.4.1 South Cascade Glacier, Washington, USA -- 9.4.2 Loch Vale, Colorado, USA -- 9.4.3 Discussion -- 9.5 Conclusions -- 9.6 Future directions in research References -- 10 NATURAL ORGANIC MATTER IN CATCHMENTS James F. Ranville & Donald L. Macalady -- 10.1 Introduction -- 10.2 The nature and origin of natural organic matter -- 10.2.1 Nature of natural organic matter -- 10.2.2 Origin of natural organic matter -- 10.3 Geochemical reactions of natural organic matter -- 10.3.1 Weathering and natural organic matter in catchments -- 10.3.2 Development of natural organic matter profiles in catchments -- 10.3.3 Hydrological controls on the transport of natural organic matter -- 10.3.4 Redox chemistry of metal-organic complexes -- 10.3.5 Natural organic matter and metal ion transport -- 10.4 Interactions between natural organic matter and anthropogenic chemicals -- 10.4.1 Transport of pollutant metals as dissolved natural organic matter complexes -- 10.4.2 Effects of sorption /partitioning to natural organic matter on the transport of organic chemicals -- 10.4.3 Effects of natural organic matter on hydrolytic reactions -- 10.4.4 Oxidation /reduction reactions facilitated by natural organic matter -- 10.4.5 Colloidal natural organic matter and facilitated transport -- 10.4.6 Natural organic matter... sink for pollutants or facilitator of transport? Mysteries and research questions -- 10.5 Conclusions -- 10.6 Future research directions -- References -- 11 RELATIONSHIP BETWEEN ROCK, SOIL AND GROUNDWATER COMPOSITIONS John Mather -- 11.1 Introduction -- 11.2 The source term -- 11.3 Factors affecting groundwater chemistry -- 11.4 Reactions in the unsaturated zone -- 11.4.1 Gas dissolution and redistribution -- 11.4.2 Carbonate and silicate dissolution -- 11.4.3 Sulphide oxidation -- 11.4.4 Gypsum precipitation and dissolution -- 11.4.5 Cation exchange -- 11.4.6 Organic reactions -- 11.5 Reactions in the saturated zone -- 11.5.1 Carbonate and silicate dissolution -- 11.5.2 Dissolution of soluble salts -- 11.5.3 Redox reactions -- 11.5.4 Cation exchange -- 11.6 Saline groundwaters -- 11.7 Groundwater compositions -- 11.8 Anthropogenic influences -- 11.8.1 Agricultural pollution -- 11.8.2 Industrial pollution -- 11.8.3 Acid rain -- 11.9 Conclusions -- 11.10 Future research -- References -- 12 TOWARDS COUPLING HYDROLOGICAL, SOIL AND WEATHERING PROCESSES WITHIN A MODELLING PERSPECTIVE Colin Nealy Alice J. Robson & Nils Christophersen -- 12.1 Introduction -- 12.1.1 General -- 12.2 A case study from Wales -- 12.2.1 Description of the study area -- 12.2.2 Hydrochemistry -- 12.3 Sources contributing to stream flow -- 12.3.1 Rationale -- 12.3.2 Hydrograph separation -- 12.3.3 Hydrograph separation using continuous data -- 12.3.4 Conclusions concerning water mixing relationships -- 12.4 Chemical mixing, speciation and solubility controls for aluminium -- 12.4.1 Rationale -- 12.4.2 Modelling chemical speciation -- 12.4.3 Mixing model results -- 12.5 Modelling studies -- 12.5.1 Modelling background -- 12.5.2 Short term modelling studies -- 12.5.3 Long term modelling studies -- 12.6 Towards integrated models -- 12.6.1 Developing a cation exchange model accounting for soil heterogeneity -- 12.6.2 Summary of findings -- 12.7 Discussions -- 12.8 Recommendations -- 12.9 Conclusions -- 12.10 Future research directions -- References -- 13 CHEMICAL CHANGES ATTENDING WATER CYCLING THROUGH -- A CATCHMENT - AN OVERVIEW -- Patrice de Caritat & Ola M. Saether -- 13.1 Introduction -- 13.2 The geochemical cycle -- 13.3 The water cycle -- 13.4 Every drop of rain -- 13.5 Soil searching -- 13.6 The water table -- 13.7 Discharge! -- 13.8 All the rivers run -- Acknowledgements -- A non-comprehensive list of useful references -- LIST OF AUTHORS -- INDEX.

    Biography

    Dr Ola M Saether and Patrice de Caritat are senior research scientists at the Geochemistry and Hydrogeology Section of the Geological Survey of  Norway.