Author: Taylor Maavara
Publisher:
ISBN:
Category : Biogeochemical cycles
Languages : en
Pages : 175
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Book Description
The damming of rivers represents one of the most far-reaching human modifications to the flows of water and associated matter from land to sea. Globally there are over 70 000 large dams whose reservoirs store more than seven times as much water as natural rivers. Due to increasing demands for energy, irrigation, drinking water, and flood control, the construction of dams will continue into the foreseeable future. Indeed, there is currently an ongoing boom in dam construction, particularly focused in emerging economies, which is expected to double the fragmentation of rivers on Earth. Essential nutrient elements such as phosphorus (P), nitrogen (N), silicon (Si), and carbon (C) are transported and transformed along the land-ocean aquatic continuum (LOAC), forming the basis for freshwater food webs in lakes, rivers, wetlands, reservoirs, and floodplains, and ultimately for marine food webs in estuarine and coastal environments. The dam-driven fragmentation of the rivers along the LOAC will significantly modify global nutrient and C fluxes via elimination from the water column in reservoirs. In this thesis, I quantify in-reservoir elimination and transformation fluxes for phosphorus (P), silicon (Si), and organic carbon (OC), with the goal of determining (1) how much Si, P, and organic C (OC) are retained or eliminated globally due to river damming, (2) how damming modifies the balance of productivity (heterotrophy vs. autotrophy) in river systems worldwide, (3) to what extent damming changes nutrient speciation or reactivity along the LOAC, and (4) if reservoirs retain or eliminate certain nutrients more efficiently than others, and if so, how this decoupling changes nutrient ratios delivered to coastal zones. I address these research questions at the reservoir scale, by quantifying nutrient elimination in Lake Diefenbaker, Saskatchewan, and through the development of spatially explicit global nutrient and carbon models. In Chapter 2, I present a reservoir-scale field study of reactive silicon dynamics in Lake Diefenbaker, a reservoir in Canada's central prairie province of Saskatchewan. I use a year-round dataset of surface water samples and sediment cores to construct a Si budget for the reservoir, including an estimation of the amount of Si buried in the reservoir annually. I use this study to illustrate the differences in retention of Si relative to N and P, and put forth the hypothesis that river damming results in a decoupling of nutrient cycling. This study acts as an introduction to the concept of differential nutrient retention in reservoirs, which I go on to show at the global scale for Si, P, and C in reservoirs in Chapters 3, 4, and 5. Following Chapter 2, I address my research questions by developing a mechanistic approach to global scale biogeochemical modelling. This approach yields spatially explicit results, which allows for the quantification of regional watershed and coastal trends, as well as lumped continental changes. In Chapter 3, the modelling approach itself is introduced, through application to the Si cycle. I show, via a meta-analysis comparing the distribution of physical and chemical parameters of published reservoir Si budgets to reservoirs worldwide, that the existing literature Si budgets are severely limited in their ability to represent the dataset of global reservoirs. I then introduce the mechanistic approach by developing a biogeochemical box model representing Si dynamics in reservoirs. I assign rate expressions to transformation fluxes and input/output fluxes, which are constrained as uniform distributions between limits that encapsulate possible global ranges. Using a Monte Carlo approach, I allow the model to randomly select each rate constant independently for 6000 iterations, generating a database of hypothetical Si dynamics in reservoirs worldwide. I use this generated dataset to establish expressions relating Si retention to water residence time, which I apply to an existing database of global reservoirs. Ultimately I develop a global estimate of dissolved and reactive Si burial in reservoirs for year 2000. Chapters 4 and 5 use the same modelling approach presented in Chapter 3, but applied to riverine P and organic carbon (OC) fluxes. Because the cycles of P and OC have been studied in more detail than Si in the literature, it is possible to constrain higher order probability density functions (PDFs) for many rate constants. In the case of OC, it also becomes possible to use a statistically significant semi-empirical approach to calculate a number of fluxes, as expressions to predict OC dynamics have been established from globally applicable datasets. Using the upstream-catchment area-normalized Global-NEWS model's watershed yields as input to each reservoir, I use the 1970, 2000, 2030 and 2050 model predictions to estimate historical and predict future P and OC elimination by dams. In Chapter 4, I show that damming retains 12% of the global total P load to watersheds in year 2000, potentially rising to 17% by 2030. In Chapter 5, I show that global OC mineralization in reservoirs exceeds carbon fixation (P
Author: Patricia M. Glibert
Publisher: Springer Nature
ISBN: 3031538978
Category :
Languages : en
Pages : 758
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Book Description
Author: Patricia M. Glibert
Publisher: Springer
ISBN: 3319700693
Category : Science
Languages : en
Pages : 460
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Book Description
Harmful algal blooms (HABs) - blooms that cause fish kills, contaminate seafood with toxins, or cause human or ecological health impacts and harm to local economies - are occurring more often, in more places and lasting longer than in past decades. This expansion is primarily the result of human activities, through increased nutrient inputs and various aspects of climate change. The Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) programme promoted international collaboration to understand HAB population dynamics in various oceanographic regimes and to improve the prediction of HABs. This volume introduces readers to the overarching framework of the GEOHAB programme, factors contributing to the global expansion of harmful algal blooms, the complexities of HABs in different habitats, and the forward-looking issues to be tackled by the next generation of GEOHAB, GlobalHAB. The programme brought together an international team of contributing scientists and ecosystem managers, and its outcomes will greatly benefit the international research community.
Author: Stefan Schmutz
Publisher: Springer
ISBN: 3319732501
Category : Science
Languages : en
Pages : 562
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Book Description
This open access book surveys the frontier of scientific river research and provides examples to guide management towards a sustainable future of riverine ecosystems. Principal structures and functions of the biogeosphere of rivers are explained; key threats are identified, and effective solutions for restoration and mitigation are provided. Rivers are among the most threatened ecosystems of the world. They increasingly suffer from pollution, water abstraction, river channelisation and damming. Fundamental knowledge of ecosystem structure and function is necessary to understand how human acitivities interfere with natural processes and which interventions are feasible to rectify this. Modern water legislation strives for sustainable water resource management and protection of important habitats and species. However, decision makers would benefit from more profound understanding of ecosystem degradation processes and of innovative methodologies and tools for efficient mitigation and restoration. The book provides best-practice examples of sustainable river management from on-site studies, European-wide analyses and case studies from other parts of the world. This book will be of interest to researchers in the field of aquatic ecology, river system functioning, conservation and restoration, to postgraduate students, to institutions involved in water management, and to water related industries.
Author: Kon-Kee Liu
Publisher: Springer Science & Business Media
ISBN: 3540927352
Category : Science
Languages : en
Pages : 757
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Book Description
This book is a product of the joint JGOFS (Joint Global Ocean Flux Study)/LOICZ (Land–Ocean Interactions in the Coastal Zone) Continental Margins Task Team which was established to facilitate continental margins research in the two projects. It contains signi cant information on the physical, biogeochemical, and ecosystems of continental margins nationally and regionally and provides a very valuable synthesis of this information and the physical, biogeochemical and ecosystem processes which occur on continental margins. The publication of this book is timely as it provides a very strong foundation for the development of the joint IMBER (Integrated Marine Biogeochemistry and Ecosystems Research)/LOICZ Science Plan and Implemen- tion Strategy for biogeochemical and ecosystems research in the continental margins and the impacts of global change on these systems. This initiative will move forward integrated biogeochemical and ecosystems research in the continental margins. We thank all the contributors to this volume and especially Kon-Kee Liu who has dedicated a great deal of time to ensuring a high-quality book is published. IMBER Scienti c Steering Committee Julie Hall LOICZ Scienti c Steering Committee Jozef Pacyna v 1 Preface In general, interfaces between the Earth’s larger material reservoirs (i. e. , the land, atmosphere, ocean, and sediments) are important in the control of the biogeoche- cal dynamics and cycling of the major bio-essential elements, including carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and silicon (Si), found in organic matter and the inorganic skeletons, shells, and tests of benthic and marine organisms.
Author: Andy Haines
Publisher: Cambridge University Press
ISBN: 1108613608
Category : Science
Languages : en
Pages : 457
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Book Description
We live in unprecedented times - the Anthropocene - defined by far-reaching human impacts on the natural systems that underpin civilisation. Planetary Health explores the many environmental changes that threaten to undermine progress in human health, and explains how these changes affect health outcomes, from pandemics to infectious diseases to mental health, from chronic diseases to injuries. It shows how people can adapt to those changes that are now unavoidable, through actions that both improve health and safeguard the environment. But humanity must do more than just adapt: we need transformative changes across many sectors - energy, housing, transport, food, and health care. The book discusses specific policies, technologies, and interventions to achieve the change required, and explains how these can be implemented. It presents the evidence, builds hope in our common future, and aims to motivate action by everyone, from the general public to policymakers to health practitioners.
Author: Christopher Osburn
Publisher: Frontiers Media SA
ISBN: 2832504922
Category : Science
Languages : en
Pages : 171
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Book Description
Author: Sanjeev Sharma
Publisher: John Wiley & Sons
ISBN: 1119696321
Category : Science
Languages : en
Pages : 324
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Book Description
Wetlands Conservation An up-to-date overview of approaches for addressing wetlands degradation and its effects on ecosystem services, human health, and other ecosystems Wetlands are essential sources of biodiversity, water purification, groundwater replenishment, flood control, storm protection, sediment retention, recreation and tourism, and more. Human exploitation of natural resources over the past 200 years has caused significant wetlands degradation and loss. Although the Ramsar Convention of 1971 drafted polices for wetland conservation and responsible use, many wetland sites remain inadequately conserved or managed. Maintaining the ecological balance and equilibrium of wetlands requires a clear understanding of the vital role of wetlands, the difficulties they face, and the policies enacted for their protection. Wetlands Conservation: Current Challenges and Future Strategies summarizes both current and emerging management strategies, trends, and policies regarding wetlands protection around the world. The authors provide accurate scientific information on wetlands while discussing the effects of climate change, global warming, modernization in agriculture, and other key topics. Designed to assist in the development of future solutions for wetlands conservation and management strategies, this important volume: Highlights the environmental, socioeconomic, and cultural importance of wetlands Identifies the factors responsible for the failure of many conservation initiatives Describes the natural and anthropogenic factors of wetlands degradation Discusses the role of community-based wetlands conservation and management Explores Ramsar wetlands conservation and its impacts worldwide Wetlands Conservation: Current Challenges and Future Strategies is an invaluable resource for graduate and postgraduate students, researchers, ecologists, policymakers, conservation organizations, and others working in the field of natural resources management.
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309072549
Category : Nature
Languages : en
Pages : 107
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Book Description
Scientists have long sought to unravel the fundamental mysteries of the land, life, water, and air that surround us. But as the consequences of humanity's impact on the planet become increasingly evident, governments are realizing the critical importance of understanding these environmental systemsâ€"and investing billions of dollars in research to do so. To identify high-priority environmental science projects, Grand Challenges in Environmental Sciences explores the most important areas of research for the next generation. The book's goal is not to list the world's biggest environmental problems. Rather it is to determine areas of opportunity thatâ€"with a concerted investmentâ€"could yield significant new findings. Nominations for environmental science's "grand" challenges were solicited from thousands of scientists worldwide. Based on their responses, eight major areas of focus were identifiedâ€"areas that offer the potential for a major scientific breakthrough of practical importance to humankind, and that are feasible if given major new funding. The book further pinpoints four areas for immediate action and investment.
Author:
Publisher: Academic Press
ISBN: 0080878857
Category : Science
Languages : en
Pages : 4604
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Book Description
The study of estuaries and coasts has seen enormous growth in recent years, since changes in these areas have a large effect on the food chain, as well as on the physics and chemistry of the ocean. As the coasts and river banks around the world become more densely populated, the pressure on these ecosystems intensifies, putting a new focus on environmental, socio-economic and policy issues. Written by a team of international expert scientists, under the guidance of Chief Editors Eric Wolanski and Donald McClusky, the Treatise on Estuarine and Coastal Science, Ten Volume Set examines topics in depth, and aims to provide a comprehensive scientific resource for all professionals and students in the area of estuarine and coastal science Most up-to-date reference for system-based coastal and estuarine science and management, from the inland watershed to the ocean shelf Chief editors have assembled a world-class team of volume editors and contributing authors Approach focuses on the physical, biological, chemistry, ecosystem, human, ecological and economics processes, to show how to best use multidisciplinary science to ensure earth's sustainability Provides a comprehensive scientific resource for all professionals and students in the area of estuarine and coastal science Features up-to-date chapters covering a full range of topics
