Greenhouse Gas Emissions - Fluxes and Processes: Hydroelectric Reservoirs and Natural Environments (Environmental Science and Engineering / Environmental Science)

In a time when an unquestionable link between anthropogenic emissions of greenhouse gases and climatic changes has finally been acknowledged and \* widely documented through IPCC reports, the need for precise estimates of greenhouse gas (GHG) production rates and emissions from natural as well as managed ecosystems has risen to a critical level. Future agreements between nations concerning the reduction of their GHG emissions will - pend upon precise estimates of the present level of these emissions in both natural and managed terrestrial and aquatic environments. From this viewpoint, the present volume should prove to a benchmark contribution because it provides very carefully assessed values for GHG emissions or exchanges between critical climatic zones in aquatic en- ronments and the atmosphere. It also provides unique information on the biases of different measurement methods that may account for some of the contradictory results that have been published recently in the literature on this subject. Not only has a large array of current measurement methods been tested concurrently here, but a few new approaches have also been developed, notably laser measurements of atmospheric CO concentration 2 gradients. Another highly useful feature of this book is the addition of - nitoring and process studies as well as modeling. Cover......Page 1 Environmental Science......Page 2 Greenhouse Gas Emissions - Fluxes and Processes......Page 4 ISBN 9783540234555......Page 5 Contents......Page 8 1.1 Greenhouse Gases and Reservoirs......Page 52 1.2.1 Water Quality......Page 58 1.2.2 Plankton......Page 61 1.2.3 Benthos......Page 62 1.3 Contents and Rationales......Page 63 Gross Emissions......Page 66 Abstract......Page 68 2.2 History of the Methods Used by Hydro-Québec......Page 69 2.3.1 Floating Chambers with in situ Laboratory Analysis......Page 70 2.3.2 Floating Chambers with ex situ Laboratory Analysis......Page 73 2.3.3 Floating Chambers Coupled to an NDIR or FTIR Instrument......Page 74 2.3.4 Thin Boundary Layer......Page 76 2.4.2 Effect on the Mode of Transportation of the Samples......Page 78 2.4.4 Quality Control for all Methods......Page 79 2.4.5 Comparison of the two Methods with Syring......Page 83 2.4.6 Comparison of Syringe and Thin Boundary Layer Methods......Page 84 2.4.7 Comparison of Syringe and Automated Instrument Methods......Page 85 2.4.8 Comparison of NDIR and FTIR Instruments......Page 86 2.4.9 Advantages and Disadvantages for Each Method......Page 88 2.5 Conclusion......Page 91 Abstract......Page 92 3.1 Introduction......Page 93 3.2.1 Choice of the Gradient Technique for Flux Estimates......Page 94 3.2.2 Assessing Average CO[sub(2)] and CH[sub(4)] Concentration Gradients......Page 95 3.2.3 Assessing Average GHG fluxes......Page 96 3.3.1 Description of the Optical Paths......Page 97 3.3.2 Spectral Resolution of the Laser Device......Page 99 3.3.3 Description of the Signal Detection......Page 100 3.4.1 Technical Developments and Optimizations......Page 102 3.4.2 CO[sub(2)] and CH[sub(4)] Fluxes at FLUDEX - ELA Experimental Reservoir......Page 103 3.4.3 CO[sub(2)] and CH[sub(4)] Fluxes at Robert-Bourassa Hydroelectric Reservoir......Page 110 3.4.4 Major Benefits of Flux Measurements by Tunable Diode Lasers......Page 114 3.5 Conclusion and Directions for Future Work......Page 115 Abstract......Page 118 4.1 Introduction......Page 119 4.2 Net Ecosystem Exchange of CO[sub(2)] (NEE) in Forests......Page 120 4.3 Net Ecosystem Exchange of CO[sub(2)] in Wetlands......Page 128 4.4 CH[sub(4)] Fluxes in Wetlands......Page 132 4.5 CH[sub(4)] Fluxes in Forests......Page 144 4.6 N[sub(2)]O Fluxes in Forest and Wetland Soils......Page 147 4.8 GHG Budgets in Forests and Wetlands......Page 151 4.9 General Evaluation of Gas Flux Data......Page 156 Abstract......Page 160 5.1 Introduction......Page 161 5.2 Lakes and Reservoirs Sampled in this Study......Page 164 5.2.1 Sediment Sampling for Gases......Page 166 5.2.2 Diffuse Flux Calculations......Page 169 5.3.1 Sediment Gas Diffuse Flux......Page 173 5.3.2 Relationships Between Sediment Gas Fluxes and Lake and Reservoir Trophic Conditions......Page 177 Acknowledgements......Page 183 Abstract......Page 186 6.1 Introduction......Page 187 6.2 Soil Organic Carbon Density......Page 188 6.3 Physical and Biological Factors Affecting SOC Density......Page 196 6.4 Uncertainties of SOC Estimates......Page 200 6.5 Organic Carbon in Vegetation......Page 201 6.6 High Spatial Heterogeneity of Biomass......Page 204 6.7 Uncertainties in Evaluating the Organic Carbon in Vegetation......Page 209 6.8 Total Carbon Densities and Stocks of Forest Biomes......Page 212 6.9 Export of Organic Carbon to Aquatic Ecosystems......Page 214 6.10 Conclusion......Page 216 Abstract......Page 218 7.2 Estuaries: Some Useful Definitions for Describing Carbon Cycling and Gas Emissions......Page 219 7.3 Organic Carbon Sources and Mineralization in Estuaries......Page 221 7.4 Estuarine Specificity for Gas Transfer......Page 222 7.5 Carbon Dioxide Emissions......Page 225 7.6 Methane Emissions......Page 231 7.7 Significance at the Global Scale......Page 237 Acknowledgments......Page 238 8.1 Introduction......Page 240 8.2.1 Study Areas......Page 241 8.2.2 Measurement of GHG Fluxes and Other Variables......Page 243 8.3.1 Spatial Variation of GHG Emissions......Page 249 8.3.2 Temporal Variation of GHG Emission from Reservoirs......Page 260 8.4 Conclusion......Page 262 9.1 Introduction......Page 264 9.2.1 Study Areas......Page 265 9.2.3 General Chemical Characteristics of the Water Bodies......Page 270 9.3 Results and Discussion......Page 274 9.4 Conclusion......Page 281 10.1 Introduction......Page 282 10.2.1 The model......Page 284 10.3.1 ELARP......Page 288 10.3.2 FLUDEX......Page 290 10.4 Discussion......Page 292 10.5 Conclusions......Page 296 11.1 Introduction......Page 298 11.2.1 Site Description......Page 299 11.3 Methodology......Page 300 11.4 Results and Discussion: Gross Emissions of CO[sub(2)] and CH[sub(4)] from Brazilian Power Dams......Page 302 11.5 Concluding Remarks and Future Orientations......Page 310 11.6.1 Procedures for Capturing Bubbles......Page 312 11.6.2 Calculation of Averages of Greenhouse Gases Emissions by Bubbles......Page 313 11.6.4 Principle of Exchange Rates Measurement......Page 315 Acknowledgements......Page 322 12.1 Introduction......Page 324 12.2.2 Measurements......Page 326 12.3.1 Observed and Predicted Emissions Over 20 Years......Page 328 12.3.3 Long Term Data and Recent Flux Measurements......Page 336 12.4 Conclusion and Perspective......Page 340 12.4.1 Future Initiatives......Page 341 Acknowledgments......Page 343 Processes Leading to GHG Production......Page 344 Abstract......Page 346 13.1 Introduction......Page 347 13.2.1 Field Site and Sample Collection......Page 349 13.2.3 Experimental Conditions......Page 350 13.2.4 Measurements of Carbon Dioxide and Methane......Page 353 13.2.5 Production of Gases......Page 354 13.3.1 Soil Samples......Page 355 13.3.2 Vegetation Samples......Page 359 13.4 Conclusion......Page 367 Acknowledgements......Page 369 14.1 Introduction......Page 370 14.2.1 Study Site......Page 372 14.2.3 In situ Sampling Measurements......Page 374 14.3 Model Construction......Page 376 14.4 Estimation of the FCO[sub(2 prod)]./FCO[sub(2 atm. eq.)] for the Robert-Bourassa Reservoir......Page 377 14.5 Estimating FCO[sub(2 atm. eq)] and Mean CO[sub(2)] Flux at the Air-Water Interface......Page 379 14.6 Estimate of the Mean Annual Diffusive CO[sub(2)] Flux from the Robert-Bourassa Reservoir......Page 383 14.7 Comments and Conclusions......Page 384 Abstract......Page 386 15.1 Introduction......Page 387 15.2.1 Study Site and Reservoir Construction......Page 388 15.2.2 Theoretical Approach to Quantification of Net Reservoir CO[sub(2)] and CH[sub(4)] Production, Gross DIC Production and NPP, and CH[sub(4)] Production and CH[sub(4)] Oxidation......Page 391 15.2.3 Inorganic C and CH[sub(4)] Mass Budgets and Stable Carbon Isotopic Ratio Mass Budgets......Page 393 15.2.4 δ[sup(13)]C Values of Gross DIC Production, NPP, CH[sub(4)] Production and Oxidation......Page 395 15.2.5 Analytical Methods......Page 397 15.3.1 Inorganic C and CH[sub(4)] Budgets and Net Reservoir CO[sub(2)] and CH[sub(4)] Production......Page 398 15.3.2 Gross Reservoir DIC Production and Consumption Via NPP......Page 400 15.3.3 CH[sub(4)] Production and Oxidation......Page 407 15.3.4 Reservoir GHG Production, OC Storage, and Timescale......Page 408 15.3.5 Extrapolation of FLUDEX Results to Other Studies......Page 410 15.4 Conclusions......Page 413 16.1.1 Emission of Greenhouse C Gases......Page 414 16.1.2 Contribution of Soils from Forest Ecosystems......Page 416 16.2 Organic Carbon in Forest Soils......Page 417 16.2.1 Biogeochemical Cycle of Organic Carbon in Forested Ecosystems......Page 418 16.2.2 Key Role of Forest Soils in the Organic Carbon Cycle......Page 421 16.2.3 Nature and Properties of Organic Substances in Soils......Page 423 16.2.4 Functions of Organic Carbon in Soils......Page 427 16.2.5 Links between Carbon and Other Elemental Cycles in Forest Soils......Page 429 16.3.1 Forest Ecosystems from Northeastern North America......Page 436 16.3.3 Forest Ecosystems from Northwestern Europe......Page 444 16.3.4. Carbon Pools and Fluxes in Northern Wetlands......Page 445 16.4.1 Net Role of Soils on the Cycling of Organic Carbon in Terrestrial Ecosystems......Page 448 16.4.2 Changes in the Transport of DOC from Terrestrial to Aquatic Ecosystems......Page 450 17.1 Introduction......Page 452 17.2.1 Long-term Data Set (1978-1984)......Page 454 17.2.2 Recent Data Set......Page 458 17.3.1 Long-term Variation in Zooplankton Community (1978-1984)......Page 459 17.3.2 Relation with Water Quality and Trophic Status......Page 461 17.3.3 Recent Data Set: A Comparison between Reservoirs......Page 463 17.4 Discussion......Page 467 17.5 Conclusions......Page 471 Abstract......Page 472 18.1 Introduction......Page 473 18.2.1 Site Description and Sample Collection......Page 474 18.2.2 Physico-Chemical Variables......Page 475 18.2.3 Bacterial Methane Metabolism......Page 476 18.3.1 Methanogenesis......Page 479 18.3.2 Methanotrophy......Page 485 18.4.1 Methanogenesis......Page 488 18.4.2 Methanotrophy......Page 491 18.5 Methane Biogeochemistry and Concluding Remarks......Page 494 Acknowledgments......Page 496 Abstract......Page 498 19.1 Introduction......Page 499 19.2 Study Sites and Methods......Page 500 19.3.1 Temperature and DOC......Page 502 19.3.2 Bacterial Abundance and Production in the Study Sites......Page 504 19.4.1 Factors Affecting Bacterioplankton Activities (i.e. Production, Specific Production and% HNA)......Page 506 19.4.2 Bacterioplankton Activities and Variations in CO[sub(2)] Fluxes to the Atmosphere......Page 509 19.4.3 Contribution of Bacterioplankton Activities to CO[sub(2)] Fluxes from Freshwaters to the Atmosphere......Page 510 19.5 Conclusion......Page 513 Abstract......Page 514 20.1 Introduction......Page 515 20.2 Study Site......Page 516 20.3 Methods......Page 518 20.4.1 Phytoplankton Biomass......Page 521 20.4.2 Areal Gross Production......Page 523 20.4.3 Areal Planktonic Respiration......Page 524 20.4.4 Spatial Variation of the Production: Respiration Ratio......Page 525 20.4.5 Gross Primary Production and Total Respiration Mass Balance and their Relationship to CO[sub(2)] Flux at the Water-Air Interface......Page 534 Abstract......Page 540 21.2 Ultraviolet Radiation and Dissolved Organic Matter......Page 541 21.2.1 Types of Dissolved Organic Matter......Page 542 21.2.2 Dissolved Organic Matter Quality......Page 543 21.2.3 Photoreactions and DOM......Page 545 21.2.4 Ionic Conditions......Page 549 21.3.1 Plankton......Page 550 21.3.2 Harmful Effects of UV on Microorganisms......Page 552 21.4.1 Vegetation......Page 553 21.4.4 Estimate of the Rate of Photooxidation in Reservoirs......Page 554 21.5 Conclusion......Page 557 22.1 Introduction......Page 560 22.2.1 The Example of the Petit Saut Reservoir and the Downstream River......Page 562 22.2.2 Measurements......Page 564 22.3.1 Stratification and General Water Quality......Page 565 22.3.2 Methane Production and Oxidation in the Reservoir......Page 569 22.3.3 Principal Factors Influencing Water Quality......Page 572 22.4.1 Evidence of a Consumption of Dissolved Oxygen in the Downstream Sinnamary River Due to an Oxidation of Dissolved Methane......Page 575 22.4.2 Building of an Aerating Weir in the Plant Outlet Canal in Order to Guarantee 2 mg L[sup(-1)] of DO in the Downstream Sinnamary River......Page 578 22.4.3 Historical Reconstruction (1994-2002) of the DM Concentrations and Fluxes in the Water Crossing the Dam......Page 579 22.4.4 Efficiency of DM Elimination in the Near Downstream of the Dam (1994-2002)......Page 581 22.4.5 DM Emissions to the Atmosphere in the Sinnamary River Downstream of the Aerating Weir......Page 584 22.4.6 A New Assessment of the Methane Emissions to the Atmosphere in the Downstream Sinnamary River (1994-2002 Period)......Page 587 22.4.8 The Role of DM Oxidation in the DO Budget of the Downstream Sinnamary......Page 588 22.5 General Conclusion......Page 589 Acknowledgements......Page 591 Modelling......Page 592 23.1 Introduction......Page 594 23.2 Methods Used to Estimate Gas Exchange......Page 595 23.3 Discussion of the Methods......Page 597 23.4 Using a Model to Assist Interpretation......Page 599 23.5 Other Sources of Variability......Page 602 23.6 Conclusion......Page 605 24.1 Introduction......Page 606 24.2 Thermodynamic Lake Models......Page 608 24.3.1 Energy Balance Equations......Page 609 24.3.2 Turbulent Diffusion......Page 610 24.3.4 Ice Model......Page 614 24.4 Calculation of CO[sub(2)] and CH[sub(4)] Fluxes at the Air-Water Interface......Page 615 24.4.2 Thin Boundary Layer (TBL)......Page 616 24.5.1 Model Definition of Atmospheric GHG Concentrations and GHG Sources and Sinks......Page 618 24.5.2 Sensitivity Test and Validation......Page 620 24.5.3 Application: Comparison of the Annual CO[sub(2)] Emissions for Two Reservoirs in Central Northern Québec......Page 623 24.6 Conclusion......Page 624 Abstract......Page 628 25.1 Introduction......Page 629 25.2.1 Basic configuration of the reservoir......Page 632 25.2.2 Constitutive equations of the model......Page 635 25.3 Mass transfer of CO[sub(2)] and CH[sub(4)] at the water-air interface......Page 636 25.3.1 Wind effect......Page 637 25.3.3 Mass transfer coefficient for carbon dioxide and methane......Page 638 25.3.4 Effect of ice formation......Page 640 25.3.7 Effect of pH......Page 643 25.3.8 Kinetic parameters......Page 644 25.3.9 Numerical solution of the constitutive equations......Page 647 25.4.1 Input data to the model......Page 649 25.4.2 Simulation with the model......Page 656 25.5.1 Model characteristics......Page 664 25.5.2 Performance of the model......Page 665 Acknowledgements......Page 666 Abstract......Page 668 26.1.1 Terrestrial Ecosystems......Page 669 26.1.2 Aquatic Ecosystems......Page 671 26.1.3 Estuaries......Page 673 26.2 The Issue of Greenhouse Gases in Hydroelectric Reservoirs......Page 675 26.2.1 Flooded Soils and Sediments......Page 676 26.2.2 Water Column......Page 681 26.2.3 Exchange at the Water-Air Interface......Page 682 26.2.4 Reservoir Characteristics......Page 686 26.2.5 Assessment of Net GHG Emissions from Reservoirs......Page 687 26.2.6 Comparison of GHG Emissions from Various Energy Sources......Page 688 26.2.6 Conclusion and Unresolved Issues......Page 690 References......Page 692 This is the first book to provide measurements of greenhouse gases from both aquatic and terrestrial environments as well as from hydroelectric reservoirs. This monograph not only presents the state-of-the-art techniques for measuring the emissions of greenhouse gases, but also demonstrates the mechanisms or processes leading to the emissions of greenhouse gases. It offers the reader a synthesis of what we understand of GHG emission after 12 years of research in boreal ecosystems, the estimations of gross and net emissions from hydroelectric reservoirs, the impact of hydroelectric reservoirs on climate change, as well as a comparison of the different alternatives for producing energy in relation to GHG emissions. "This is the first book to provide measurements of greenhouse gases from both aquatic and terrestrial environments as well as from hydroelectric reservoirs. This monograph not only presents the state-of-the-art techniques for measuring the emissions of greenhouse gases, but also demonstrates the mechanisms or processes leading to the emissions of greenhouse gases."--BOOK JACKET