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Climate change is expected to cause more intense and frequent extreme weather events, but we only have a basic understanding of how these events might alter freshwater systems. Storms are likely to impact lake systems through delivery of sediments from watersheds and mixing of the water column, both of which could have important consequences for phytoplankton. Phytoplankton are the base of the food web; their community configuration and how the community changes across seasons have large impacts on ecosystem processes such as energy flow, nutrient cycling, and carbon cycling. External disturbances may abruptly alter phytoplankton community dynamics and thus impact ecosystem function. The effects of storms on the...
Streamflow is declining in many parts of the United States (US) due to factors including groundwater pumping, land use change, and climate change. Streamflow depletion, a reduction in groundwater discharge to a stream due to human activities such as pumping and/or land use change, tends to evolve slowly and can be entirely invisible for many years to decades. This is because streamflow depletion can be masked by the natural and/or climate change-induced variability in streamflow, and groundwater storage can buffer the impacts on streams. The negative effects on both anthropogenic and ecological systems can evolve over decades or more, and specific causes and potential solutions to these issues are often difficult...
Given that Reclamation is conducting multiple long-term water resources assessments at any given time within each of its regions, and given that climate change now must be addressed in such documentation efforts, it is in Reclamation’s interests to have a consistent portrayal of climate change literature within each of these documents. Further, Reclamation can alleviate the burden on project-specific scoping efforts to include development of such narratives by instead developing and maintaining region-applicable narratives. Fiscal year (FY) 2010 involved releasing the first version of “Literature Synthesis on Climate Change Implications for Reclamation’s Water Resources” (pdf). FY 2011 involves completing and releasing...
Categories: Project;
Types: ScienceBase Project;
Tags: Science,
climate change,
environmental compliance,
literature,
water resources
Dam decommissioning is rapidly emerging as an important river restoration strategy in the U.S., with several major removals recently completed or in progress. But few studies have evaluated the far-reaching consequences of these significant environmental perturbations, especially those resulting from removals of large (>10-15 m tall) structures during the last decade. In particular, interactions between physical and ecological aspects of dam removal are poorly known. From recent work, however, observations are now available from several diverse settings nationwide to allow synthesis of key physical and ecological processes associated with dam removals, including fish and benthic community response, reservoir erosion,...
Drylands are integral to the Earth system and the present and future of human society. Drylands encompass more than 40% of the terrestrial landmass and support 34% of the world’s human population. Biocrusts are the “living skin” of Earth’s drylands, sometimes dominating the ground cover and figuring prominently in ecosystem structure and function. Biocrusts are a biological aggregate of cyanobacteria, fungi, algae, lichens and mosses in the surface millimeters of soil. By aggregating soil, biocrusts make sediment less erodible. They also strongly influence the water runoff-infiltration balance. In some ecosystems they generate runoff, whereas in other systems they enhance water capture. Vascular plant germination,...
Groundwater contaminated with naturally occurring arsenic is a widespread problem affecting many alluvial and deltaic aquifer systems throughout the world. The human health toll from consuming groundwater with high levels of arsenic is staggering in its proportions. Furthermore, the use of arsenic contaminated groundwater for irrigation is observed to result in diminished crop yields and thus poses a threat to food security in arsenic affected regions. Decades of research at individual field sites have resulted in the collection of many geochemical and geologic datasets. A key feature of alluvial and deltaic aquifer systems is the large degree of spatial variability in groundwater arsenic concentrations from local...
Categories: Project;
Tags: Active,
All Working Groups,
Environmental Health,
Water Resources,
arsenic,
Fluid injection induced seismicity has been reported since the 1960s. There are currently more than 150,000 injection wells associated with oil and gas production in 34 states in the conterminous US. Pore pressure disturbance caused by injection is generally considered the culprit for injection induced seismicity, but, not all injection causes seismicity. It is not well understood what mechanical and hydrologic conditions cause some sites to be more prone than others to seismicity. The objectives of this proposed research are to utilize existing data on fluid injection and seismicity to (1) identify spatial and temporal correlations between fluid injection and induced seismicity; (2) conduct a hydro-mechanical modeling...
Categories: Data,
Project;
Tags: All Working Groups,
Completed,
Energy and Minerals,
Natural Hazards,
Seismicity,
Streams and rivers have a limited spatial extent, but are increasingly recognized as key components of regional biogeochemical cycles. The collective metabolic processing of organisms, known as ecosystem metabolism, is centrally important to nutrient cycling and carbon fluxes in these environments, but is poorly integrated into emerging biogeochemical concepts. This line of inquiry lags behind other aspects of regional biogeochemistry because of the lack of long-term, regionally-diverse studies of stream metabolism. With a few exceptions, metabolism studies have focused on small headwater catchments using short-term (days to weeks) observation. As a consequence, basic patterns and controls of this fundamental process,...
Categories: Data,
Project;
Tags: Active,
All Working Groups,
Aquatic carbon,
Ecosystems,
Water Quality,
Water in the United States is used for myriad activities on a daily basis, such as for food (irrigation, aquaculture, livestock), energy (thermoelectric power or hydropower generation), and public water supply for domestic, commercial or industrial purposes. Yet, we lack an national accounting of how and where water is used on a temporal scale more frequent than every 5 years, and a spatial scale greater than county level. The “water data drought” in the U.S. and globally is one of the key barriers inhibiting our understanding of how the environment sustains society and how society alters the environment. The world’s best mesoscale water use dataset is the USGS Water-Use report (the so-called “water census”), which...
Rivers are the veins of the landscape, providing environmental benefits that are disproportionately high relative to their aerial extent; shedding flood waters, hosting aquatic ecosystems, transporting solutes and energy-rich materials, and storing and transforming pollutants into less harmful forms. From uplands to the coasts, rivers facilitate key biogeochemical reactions that cumulatively influence water quality. Many of the reactions are optimized outside the main channel, in hyporheic zones, riparian zones, and floodplain areas, where riverine water is in close contact with geochemically and microbially-active sediments. However, little is known about the distribution, intermittency, and overall effectiveness...
Fluid circulation in the Earth’s crust plays an essential role in surface, near surface, and crustal dynamics. Near the surface, soil water and groundwater interact with each other and with rivers, lakes and wetlands, affecting weathering, soil formation, ecosystem evolution and biogeochemical cycles. Further down (1km), fluid flow affects diagenesis, hydrocarbon maturation and migration, ore deposits, faulting and earthquakes, and geothermal resources. The myriad flow pathways are driven by hydraulic gradients but controlled by the permeability of the crust material. To date, a large‐scale dataset of crustal permeability does not exist, inhibiting the understanding of large‐scale processes and the integration of...
Categories: Project;
Tags: All Working Groups,
Climate Models,
Completed,
Core Science Systems,
Crustal Process Models,
Global climate change is putting unprecedented pressure on global croplands and their water use, vital for ensuring future food security for the world's rapidly expanding human population. The end of the green green revolution (productivity per unit of land) era has meant declining global per capita agricultural production requiring immediate policy responses to safeguard food security amidst global climate change and economic turbulence. Above all, global croplands are water guzzlers, consuming between 60-90% of all human water use. With increasing urbanization, industrialization, and other demands (e.g., bio-fuels) on water there is increasing pressure to reduce agricultural water use by producing more food from...
Drought impacts on terrestrial ecosystems have increased globally in the 21st century, and droughts are expected to become more frequent, extreme, and spatially extensive in the future. Historical site-based observations are inadequate to predict how future extreme water deficits will affect the global terrestrial surface, because future droughts and their impacts may be more extreme than they have been historically and reach well beyond a single ecosystem. This USGS Powell Center working group will conduct the first comprehensive synthesis of ecosystem impacts across a coordinated, globally distributed drought experiment network of over 100 sites that have imposed an extreme multi-year drought. Knowledge about...
Groundwater plays a critical role in the water balance, however the groundwater component of the hydrologic cycle is frequently overlooked at basin scales because it is difficult to observe and quantify. We address this problem through a novel framework that combines existing hydrological models and data sets with groundwater flux estimates across Earth's largest system of lakes; the Laurentian Great Lakes. Aside from serving as a template for combining surface and ground water data and models, the Laurentian Great Lakes recently transitioned from a period characterized by water scarcity (water levels on the lakes were persistently below average from 1998 through 2013) to extreme water abundance (all-time high...
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