Click here to go to the USGS Water Glossaries webpage. (You know you want to spend most of the afternoon there.)
Here’s the release from the United States Geological Survey:
USGS scientists have documented that the carbon that moves through or accumulates in lakes, rivers, and streams has not been adequately incorporated into current models of carbon cycling used to track and project climate change. The research, conducted in partnership with the University of Washington, has been published this week in the Proceedings of the National Academy of Sciences.
The Earth’s carbon cycle is determined by physical, chemical, and biological processes that occur in and among the atmosphere (carbon dioxide and methane), the biosphere (living and dead things), and the geosphere (soil, rocks, and water). Understanding how these processes interact globally and projecting their future effects on climate requires complex computer models that track carbon at regional and continental scales, commonly known as Terrestrial Biosphere Models (TBMs).
Current estimates of the accumulation of carbon in natural environments indicate that forest and other terrestrial ecosystems have annual net gains in storing carbon — a beneficial effect for reducing greenhouse gases. However, even though all of life and most processes involving carbon movement or transformation require water, TBMs have not conventionally included aquatic ecosystems — lakes, reservoirs, streams, and rivers — in their calculations. Once inland waters are included in carbon cycle models, the nationwide importance of aquatic ecosystems in the carbon cycle is evident.
Speaking quantifiably, inland water ecosystems in the conterminous U.S. transport or store more than 220 billion pounds of carbon (100 Tg-C) annually to coastal regions, the atmosphere, and the sediments of lakes and reservoirs. Comparing the results of this study to the output of a suite of standard TBMs, the authors suggest that, within the current modelling framework, carbon storage by forests, other plants, and soils (in scientific terms: Net Ecosystem Production, when defined as terrestrial only) may be over-estimated by as much as 27 percent.
The study highlights the need for additional research to accurately determine the sources of aquatic carbon and to reconcile the exchange of carbon between terrestrial and aquatic environments.
Here’s the abstract:
Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71–149) teragrams of carbon per year (TgC⋅y−1) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9–65) TgC⋅y−1 in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36–110) TgC⋅y−1 or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass–flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity.
Click here to read the fact sheet from the United States Geological Survey. Here’s the introduction:
The U.S. Geological Survey’s (USGS) concept of a national census (or accounting) of water resources has evolved over the last several decades as the Nation has experienced increasing concern over water availability for multiple competing uses. The implementation of a USGS National Water Census was described in the USGS 2007 science strategy document that identified the highest priority science topics for the decade 2007–17. In 2009, the SECURE Water Act (Public Law 111–11, subtitle F) authorized the USGS to create a Water Availability and Use Assessment Program for the Nation, and in 2012, the Department of the Interior WaterSMART initiative provided funding to begin implementation of the USGS National Water Census (NWC).
Generally, the USGS NWC approaches water-availability assessment in terms of a “water budget.” The water-budget approach seeks to better quantify the inflows and outflows of water, as well as the change in storage volume, both nationally and at a regional scale and, by doing so, provides critical information to managers and stakeholders responsible for making water-availability decisions. The NWC has two primary components: Topical Studies and Geographic Focus Area Studies. Topical Studies do research on methods that can provide nationwide estimates of particular water-budget components at the subwatershed scale. Some examples of NWC Topical Studies include estimation of streamflow at ungaged locations; periodic quantification of evapotranspiration; and water use related to development of unconventional oil and gas. These efforts are planned to include additional topics in the future. Geographic Focus Area Studies (FASs) assess water availability and use within a defined geographic area, typically a surface-water drainage basin, to increase the understanding of factors affecting water availability in the region. In the FASs, local stakeholder input helps the USGS identify what components of the water budget are in most need of additional understanding or quantification. Focus Area Studies are planned as 3-year efforts and, typically, three FASs are ongoing in different parts of the country at any given time.
The Colorado River Basin (CRB) and the Delaware and Apalachicola-Chattahoochee-Flint (ACF) River Basins were selected by the Department of the Interior for the first round of FASs because of the perceived water shortages in the basins and potential conflicts over water supply and allocations. After gathering input from numerous stakeholders in the CRB, the USGS determined that surface-water resources in the basin were already being closely monitored and that the most important scientific contribution could be made by helping to improve estimates of four water-budget components: evapotranspiration losses, snowpack hydrodynamics, water-use information, and the relative importance of groundwater discharge in supporting streamflow across the basin. The purpose of this fact sheet is to provide a brief summary of the CRB FAS results as the study nears completion. Although some project results are still in the later stages of review and publication, this fact sheet provides an overall description of the work completed and cites the publications in which additional information can be found.
From the United States Geological Survey (Curt Meine):
No time seems more fitting than now – with the epic drought in California and major flooding from a nor’easter and Hurricane Joaquin – to pay tribute to Luna B. Leopold, the first chief hydrologist at the USGS. More so than any other scientist, he set the course for the USGS approach to understanding river flows, groundwater and surface water interactions and the value of long-term data collection. Today, the USGS is the world’s largest provider of hydrologic information with a mission to collect and disseminate reliable, impartial, and timely information that is needed to understand the Nation’s water resources.
Born on Oct. 8, 1915 in Albuquerque, Luna Leopold lived a rich life. From his renowned father, the biologist and author Aldo Leopold, he inherited a passion for outdoor life, a respect of craftsmanship, a highly disciplined curiosity, and an appreciation of the complex interactions of human society and natural systems. From his mother Estella, he inherited a deep connection to the semi-arid landscapes and watersheds of the American Southwest, a rich Hispanic cultural tradition, and a keen aesthetic sense. These qualities would meld and develop over time, across an extraordinary career in the earth sciences.
According to the Virtual Luna Leopold Project, “He was trained as a civil engineer (B.S degree), meteorologist (M.S. degree) and geologist (Ph.D.) and his publications reflect that blending of fields. His first publication in 1937 was entitled Relation of Watershed Conditions to Flood Discharge: A Theoretical Analysis and his most recent publication in 2005 was Geomorphic Effects of Urbanization in Forty-one Years of Observations. Few have written papers spanning 68 years, and fewer still have had such an influence on a field or on society.”
Luna Leopold’s creative intellect compelled him to explore the territory where science, policy, ethics, and environmental stewardship come together. In discerning the complex physical processes of stream formation and development, climate, precipitation, erosion, sedimentation, and deposition, he made connections to our human capacity to alter, or adapt to, hydrological realities. He understood that water science could not be separated from the water management and stewardship, which could not be separated from water ethics. On this he has been widely quoted: “Water is the most critical resource issue of our lifetime and our children’s lifetime. The health of our waters is the principal measure of how we live on the land.”
“The stream has to have change”
What he was referring to, of course, was our dominant historic tendency to reduce the inherent flux in stream systems, to manage flowing waters by controlling their dynamic variability. It is a fundamental lesson that several generations now of river managers and stewards have taken to heart and employed in restoration practice.
I suspect I highlighted that line in my notes, in part, because of its rich metaphorical potential. Luna Leopold understood change. He saw the reality of change and the need for change. He was himself an agent of change. In his field work, in his policy work, in his teaching and writing and consulting, he came to a view of rivers, of water, and of our future, that called for change. Through Luna’s understanding of science, history, and aesthetics, he came to perceive a “harmony in natural systems,” and held that “the desire to preserve this harmony must… be incorporated into any philosophy of water management, and I will call this, as did Herodotus, a reverence for rivers. If this is environmental idealism, then let it be said that I am an idealist.”
Wisdom from the past shapes the USGS today
Leopold was best known for work on the geomorphology of rivers, the study of land features and the processes that create and change them. He initiated a new era in the study of rivers, one that involved quantitative approaches that spread to the broader field of geomorphology. His research related meteorology and climatology to landscape process, a concept that has become a central feature of geomorphology. One of his better known papers, The Hydraulic Geometry of Stream Channels, published in 1953, initiated a new era in the quantitative study of rivers and stimulated quantitative approaches in geomorphology generally. Revealing an orderly framework of river behavior, the paper provided a basis for observing rivers worldwide through objective measurements and data collection.
Leopold retired from the USGS in 1972, having had a distinguished 22-year career where his focus on research and interpretation of data made a profound impact on the earth sciences. His enthusiasm for rivers proved contagious, inspiring generations of colleagues and students to devote their talents to the pursuit of science and to its application for society. Following his USGS career, Leopold, became a professor in the Department of Geology and Geophysics and the Department of Landscape Architecture at the University of California, Berkeley. He passed away in 2006 at the age of 90.
Today, as our nation is faced with the challenge of balancing a finite freshwater supply among competing needs, including agriculture, drinking water, energy production, and ecosystem health, we can appreciate even more Luna Leopold’s combination of field knowledge, leadership, and wisdom. His reverence for rivers, his way of connecting head and heart, has continued to inform new generations of scientists, policy-makers, land stewards, and philosophers who are extending his insights, exploring new dimensions in water ethics, and putting that ethic into practice. The stream has to have change. The change that Leopold helped to initiate and inspire must come. It comes more predictably, perhaps, in natural systems than in human ones. But now, as we come to know how the human and natural inevitably flow together, we can perhaps allow reverence and knowledge to flow together as well—as they did through Luna’s life.
Click through to read the report. Here’s the release from the United States Geological Survey (Dennis A. Wentz, Mark E. Brigham, Lia C. Chasar, Michelle A. Lutz, and David P. Krabbenhoft):
Major Findings and Implications
Mercury is a potent neurotoxin that accumulates in fish to levels of concern for human health and the health of fish-eating wildlife. Mercury contamination of fish is the primary reason for issuing fish consumption advisories, which exist in every State in the Nation. Much of the mercury originates from combustion of coal and can travel long distances in the atmosphere before being deposited. This can result in mercury-contaminated fish in areas with no obvious source of mercury pollution.
Three key factors determine the level of mercury contamination in fish—the amount of inorganic mercury available to an ecosystem, the conversion of inorganic mercury to methylmercury, and the bioaccumulation of methylmercury through the food web. Inorganic mercury originates from both natural sources (such as volcanoes, geologic deposits of mercury, geothermal springs, and volatilization from the ocean) and anthropogenic sources (such as coal combustion, mining, and use of mercury in products and industrial processes). Humans have doubled the amount of inorganic mercury in the global atmosphere since pre-industrial times, with substantially greater increases occurring at locations closer to major urban areas.
In aquatic ecosystems, some inorganic mercury is converted to methylmercury, the form that ultimately accumulates in fish. The rate of mercury methylation, thus the amount of methylmercury produced, varies greatly in time and space, and depends on numerous environmental factors, including temperature and the amounts of oxygen, organic matter, and sulfate that are present.
Methylmercury enters aquatic food webs when it is taken up from water by algae and other microorganisms. Methylmercury concentrations increase with successively higher trophic levels in the food web—a process known as bioaccumulation. In general, fish at the top of the food web consume other fish and tend to accumulate the highest methylmercury concentrations.
This report summarizes selected stream studies conducted by the U.S. Geological Survey (USGS) since the late 1990s, while also drawing on scientific literature and datasets from other sources. Previous national mercury assessments by other agencies have focused largely on lakes. Although numerous studies of mercury in streams have been conducted at local and regional scales, recent USGS studies provide the most comprehensive, multimedia assessment of streams across the United States, and yield insights about the importance of watershed characteristics relative to mercury inputs. Information from other environments (lakes, wetlands, soil, atmosphere, glacial ice) also is summarized to help understand how mercury varies in space and time.
More USGS coverage here
Click here to go to the USGS website. This site is not safe for history buffs at work — you may spend your entire day there.
Here’s the release from the United States Geological Survey (Anne Berry Wade/Leigh Cooper/Tanya Gallegos). (Multiply meters cubed used by 264.172052 to get gallons used). Here’s an excerpt:
The amount of water required to hydraulically fracture oil and gas wells varies widely across the country, according to the first national-scale analysis and map of hydraulic fracturing water usage detailed in a new USGS study accepted for publication in Water Resources Research, a journal of the American Geophysical Union. The research found that water volumes for hydraulic fracturing averaged within watersheds across the United States range from as little as 2,600 gallons to as much as 9.7 million gallons per well.
More oil and gas coverage here.