Trends in landscape and vegetation change and implications for the Santa Cruz Watershed
Miguel L. Villarreal, Laura M. Norman, Robert H. Webb, Raymond M. Turner
2013, Book, Proceedings of the Science on the Sonoita Plain Symposium
Monitoring and characterizing the interactive effects of land use and climate on land surface processes is a primary focus of land change science, and of particular concern in arid Wells Distribution in Shallow Groundwater Areas Pumping Trends Increase Streamflow Extent Declines 27 environments where both landscapes and livelihoods can be...
Transport and fate of microbial pathogens in agricultural settings
Scott A. Bradford, Veronica L. Morales, Wei Zhang, Ronald W. Harvey, Aaron I. Packman, Arvind Mohanram, Claire Welty
2013, Critical Reviews in Environmental Science and Technology (43) 775-893
An understanding of the transport and survival of microbial pathogens (pathogens hereafter) in agricultural settings is needed to assess the risk of pathogen contamination to water and food resources, and to develop control strategies and treatment options. However, many knowledge gaps still remain in predicting the fate and transport of...
Glacier variability in the conterminous United States during the twentieth century
Gregory J. McCabe, Andrew G. Fountain
2013, Climate Change (116) 565-577
Glaciers of the conterminous United States have been receding for the past century. Since 1900 the recession has varied from a 24 % loss in area (Mt. Rainier, Washington) to a 66 % loss in the Lewis Range of Montana. The rates of retreat are generally similar with a rapid loss in...
Knowledge, transparency, and refutability in groundwater models, an example from the Death Valley regional groundwater flow system
Mary C. Hill, Claudia C. Faunt, Wayne Belcher, Donald S. Sweetkind, Claire R. Tiedeman, Dmitri Kavetski
2013, Physics and Chemistry of the Earth, Parts A/B/C (64) 105-116
This work demonstrates how available knowledge can be used to build more transparent and refutable computer models of groundwater systems. The Death Valley regional groundwater flow system, which surrounds a proposed site for a high level nuclear waste repository of the United States of America, and the Nevada National Security...
Establishing an operational waterhole monitoring system using satellite data and hydrologic modelling: Application in the pastoral regions of East Africa
Gabriel B. Senay, Naga Manohar Velpuri, Henok Alemu, Shahriar Md Pervez, Kwabena O Asante, Gatarwa Karuki, Asefa Taa, Jay Angerer
2013, Pastoralism: Research, Policy and Practice (3) 1-16
Timely information on the availability of water and forage is important for the sustainable development of pastoral regions. The lack of such information increases the dependence of pastoral communities on perennial sources, which often leads to competition and conflicts. The provision of timely information is a challenging task, especially due...
Multitemporal cross-calibration of the Terra MODIS and Landsat 7 ETM+ reflective solar bands
Amit Angal, Xiaoxiong Xiong, Aisheng Wu, Gyanesh Chander, Taeyoung Choi
2013, IEEE Transactions on Geoscience and Remote Sensing (51) 1870-1882
In recent years, there has been a significant increase in the use of remotely sensed data to address global issues. With the open data policy, the data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Enhanced Thematic Mapper Plus (ETM+) sensors have become a critical component of numerous applications. These...
Use of gene-expression programming to estimate Manning’s roughness coefficient for high gradient streams
H. Azamathulla, Robert D. Jarrett
2013, Water Resources Management (27) 715-729
Manning’s roughness coefficient (n) has been widely used in the estimation of flood discharges or depths of flow in natural channels. Therefore, the selection of appropriate Manning’s nvalues is of paramount importance for hydraulic engineers and hydrologists and requires considerable experience, although extensive guidelines are available. Generally,...
Contaminants in stream sediments from seven United States metropolitan areas: part II—sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus
Nile E. Kemble, Douglas K. Hardesty, Christopher G. Ingersoll, James L. Kunz, Paul K. Sibley, Daniel L. Calhoun, Robert J. Gilliom, Kathryn Kuivila, Lisa H. Nowell, Patrick W. Moran
2013, Archives of Environmental Contamination and Toxicology (64) 52-64
Relationships between sediment toxicity and sediment chemistry were evaluated for 98 samples collected from seven metropolitan study areas across the United States. Sediment-toxicity tests were conducted with the amphipod Hyalella azteca (28 day exposures) and with the midge Chironomus dilutus (10 day exposures). Overall, 33 % of the samples were...
Fate of geothermal mercury from Yellowstone National Park in the Madison and Missouri Rivers, USA
David A. Nimick, Rodney R. Caldwell, Donald R. Skaar, Trevor M. Selch
2013, Science of the Total Environment (443) 40-54
Mercury is a worldwide contaminant derived from natural and anthropogenic sources. River systems play a key role in the transport and fate of Hg because they drain widespread areas affected by aerial Hg deposition, transport Hg away from point sources, and are sites of Hg biogeochemical cycling and bioaccumulation. The...
Toxicity of sediments potentially contaminated by coal mining and natural gas extraction to unionid mussels and commonly tested benthic invertebrates
Ning Wang, Christopher G. Ingersoll, James L. Kunz, William G. Brumbaugh, Cindy M. Kane, R. Brian Evans, Steven Alexander, Craig Walker, Steve Bakaletz
2013, Environmental Toxicology and Chemistry (32) 207-221
Sediment toxicity tests were conducted to assess potential effects of contaminants associated with coal mining or natural gas extraction activities in the upper Tennessee River basin and eastern Cumberland River basin in the United States. Test species included two unionid mussels (rainbow mussel, Villosa iris, and wavy-rayed lampmussel, Lampsilis fasciola,...
Assessing the relative bioavailability of DOC in regional groundwater systems
Francis H. Chapelle, Paul M. Bradley, Celeste A. Journey, Peter B. McMahon
2013, Ground Water (51) 363-372
It has been hypothesized that the degree to which a hyperbolic relationship exists between concentrations of dissolved organic carbon (DOC) and dissolved oxygen (DO) in groundwater may indicate the relative bioavailability of DOC. This hypothesis was examined for 73 different regional aquifers of the United States using 7745 analyses of...
Warming and the dependence of limber pine (Pinus flexilis) establishment on summer soil moisture within and above its current elevation range
Andrew B. Moyes, Cristina Castanha, Matthew J. Germino, Lara M. Kueppers
2013, Oecologia (171) 271-282
Continued changes in climate are projected to alter the geographic distributions of plant species, in part by affecting where individuals can establish from seed. We tested the hypothesis that warming promotes uphill redistribution of subalpine tree populations by reducing cold limitation at high elevation and enhancing drought stress at low...
Global change effects on Bromus tectorum L. (Poaceae) at its high-elevation range margin
Amy L. Concilio, Michael E. Loik, Jayne Belnap
2013, Global Change Biology (19) 161-172
Global change is likely to affect invasive species distribution, especially at range margins. In the eastern Sierra Nevada, California, USA, the invasive annual grass, Bromus tectorum, is patchily distributed and its impacts have been minimal compared with other areas of the Intermountain West. We used a series of in situ...
Phosphorus losses from agricultural watersheds in the Mississippi Delta
Yongping Yuan, Martin A. Locke, Ronald L. Bingner, Richard A. Rebich
2013, Journal of Environmental Management (115) 14-20
Phosphorus (P) loss from agricultural fields is of environmental concern because of its potential impact on water quality in streams and lakes. The Mississippi Delta has long been known for its fish productivity and recreational value, but high levels of P in fresh water can lead to algal blooms that...
Effects of road decommissioning on carbon stocks, losses, and emissions in north coastal California
Mary Ann Madej, Joseph Seney, Philip van Mantgem
2013, Restoration Ecology (21) 439-446
During the last 3 decades, many road removal projects have been implemented on public and private lands in the United States to reduce erosion and other impacts from abandoned or unmaintained forest roads. Although effective in decreasing sediment production from roads, such activities have a carbon (C) cost as well...
Thermokarst lakes, drainage, and drained basins
Guido Grosse, Benjamin M. Jones, Christopher D. Arp
John F. Shroder, editor(s)
2013, Book chapter, Treatise on Geomorphology
Thermokarst lakes and drained lake basins are widespread in Arctic and sub-Arctic permafrost lowlands with ice-rich sediments. Thermokarst lake formation is a dominant mode of permafrost degradation and is linked to surface disturbance, subsequent melting of ground ice, surface subsidence, water impoundment, and positive feedbacks between lake growth and permafrost...
Cancer risk from incidental ingestion exposures to PAHs associated with coal-tar-sealed pavement
E. Spencer Williams, Barbara Mahler, Peter C. Van Metre
2013, Environmental Science & Technology (47) 1101-1109
Recent (2009–10) studies documented significantly higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in settled house dust in living spaces and soil adjacent to parking lots sealed with coal-tar-based products. To date, no studies have examined the potential human health effects of PAHs from these products in dust and soil. Here...
Influence of dietary carbon on mercury bioaccumulation in streams of the Adirondack Mountains of New York and the Coastal Plain of South Carolina, USA
Karen Riva-Murray, Paul M. Bradley, Lia C. Chasar, Daniel T. Button, Mark E. Brigham, Barbara C. Scudder Eikenberry, Celeste A. Journey, Michelle A. Lutz
2013, Ecotoxicology (22) 60-71
We studied lower food webs in streams of two mercury-sensitive regions to determine whether variations in consumer foraging strategy and resultant dietary carbon signatures accounted for observed within-site and among-site variations in consumer mercury concentration. We collected macroinvertebrates (primary consumers and predators) and selected forage fishes from three sites in...
An alternative process model of preferential contaminant travel times in the unsaturated zone: Application to Rainier Mesa and Shoshone Mountain, Nevada
Brian A. Ebel, John R. Nimmo
2013, Environmental Modeling & Assessment (18) 345-363
Simulating contaminant transport in unsaturated zones with sparse hydraulic property information is a difficult, yet common, problem. When contaminant transport may occur via preferential flow, simple modeling approaches can provide predictions of interest, such as the first arrival of contaminant, with minimal site characterization. The conceptual model for unsaturated zone...
The response of Lake Tahoe to climate change
G.B. Sahoo, S.G. Schladow, J.E. Reuter, R. Coats, M. Dettinger, J. Riverson, B. Wolfe, M. Costa-Cabral
2013, Climatic Change (116) 71-95
Meteorology is the driving force for lake internal heating, cooling, mixing, and circulation. Thus continued global warming will affect the lake thermal properties, water level, internal nutrient loading, nutrient cycling, food-web characteristics, fish-habitat, aquatic ecosystem, and other important features of lake limnology. Using a 1-D numerical model - the Lake...
Small-scale turbidity currents in a big submarine canyon
Jingping Xu, James P. Barry, Charles K. Paull
2013, Geology Today (41) 143-146
Field measurements of oceanic turbidity currents, especially diluted currents, are extremely rare. We present a dilute turbidity current recorded by instrumented moorings 14.5 km apart at 1300 and 1860 m water depth. The sediment concentration within the flow was 0.017%, accounting for 18 cm/s gravity current speed due to density...
The interactive effects of excess reactive nitrogen and climate change on aquatic ecosystems and water resources of the United States
Jill Baron, E. K. Hall, B. T. Nolan, J. C. Finlay, E. S. Bernhardt, J. A. Harrison, F. Chan, E.W. Boyer
2013, Biogeochemistry (114) 71-92
Nearly all freshwaters and coastal zones of the US are degraded from inputs of excess reactive nitrogen (Nr), sources of which are runoff, atmospheric N deposition, and imported food and feed. Some major adverse effects include harmful algal blooms, hypoxia of fresh and coastal waters, ocean acidification, long-term harm to...
Sensitivity analysis of lake mass balance in discontinuous permafrost: the example of disappearing Twelvemile Lake, Yukon Flats, Alaska (USA)
S.M. Jepsen, C.I. Voss, Michelle Ann Walvoord, J.R. Rose, B. J. Minsley, B. D. Smith
2013, Hydrogeology Journal (21) 185-200
Many lakes in northern high latitudes have undergone substantial changes in surface area over the last four decades, possibly as a result of climate warming. In the discontinuous permafrost of Yukon Flats, interior Alaska (USA), these changes have been non-uniform across adjacent watersheds, suggesting local controls on lake water budgets....
Effects of linking a soil-water-balance model with a groundwater-flow model
Jennifer S. Stanton, Derek W. Ryter, Steven M. Peterson
2013, Ground Water Journal (51) 613-622
A previously published regional groundwater-flow model in north-central Nebraska was sequentially linked with the recently developed soil-water-balance (SWB) model to analyze effects to groundwater-flow model parameters and calibration results. The linked models provided a more detailed spatial and temporal distribution of simulated recharge based on hydrologic processes, improvement of simulated...
Environmental factors regulating the recruitment of walleye Sander vitreus and white bass Morone chrysops in irrigation reservoirs
Jason A. DeBoer, Kevin L. Pope, Keith D. Koupal
2013, Ecology of Freshwater Fish (22) 43-54
Understanding the environmental factors that regulate fish recruitment is essential for effective management of fisheries. Generally, first-year survival, and therefore recruitment, is inherently less consistent in systems with high intra- and interannual variability. Irrigation reservoirs display sporadic patterns of annual drawdown, which can pose a substantial challenge to recruitment of...
