Simulated natural hydrologic regime of an intermountain playa conservation site
J.S. Sanderson, N.B. Kotliar, D.A. Steingraeber, C. Browne
2008, Wetlands (28) 363-377
An intermountain playa wetland preserve in Colorado's San Luis Valley was studied to assess how its current hydrologic function compares to its natural hydrologic regime. Current hydrologic conditions were quantified, and on-site effects of off-site water use were assessed. A water-budget model was developed to simulate an unaltered (i.e., natural)...
Transient deterministic shallow landslide modeling: Requirements for susceptibility and hazard assessments in a GIS framework
J. W. Godt, R.L. Baum, W. Z. Savage, D. Salciarini, W.H. Schulz, E. L. Harp
2008, Engineering Geology (102) 214-226
Application of transient deterministic shallow landslide models over broad regions for hazard and susceptibility assessments requires information on rainfall, topography and the distribution and properties of hillside materials. We survey techniques for generating the spatial and temporal input data for such models and present an example using a transient deterministic...
Attribution of declining Western U.S. Snowpack to human effects
D.W. Pierce, T.P. Barnett, H.G. Hidalgo, T. Das, Celine Bonfils, B.D. Santer, G. Bala, M. D. Dettinger, D.R. Cayan, A. Mirin, A.W. Wood, T. Nozawa
2008, Journal of Climate (21) 6425-6444
Observations show snowpack has declined across much of the western United States over the period 1950-99. This reduction has important social and economic implications, as water retained in the snowpack from winter storms forms an important part of the hydrological cycle and water supply in the region. A formal model-based...
Rayleigh-wave dispersive energy imaging and mode separating by high-resolution linear Radon transform
Y. Luo, Y. Xu, Q. Liu, J. Xia
2008, Leading Edge (Tulsa, OK) (27) 1536-1542
In recent years, multichannel analysis of surface waves (MASW) has been increasingly used for obtaining vertical shear-wave velocity profiles within near-surface materials. MASW uses a multichannel recording approach to capture the time-variant, full-seismic wavefield where dispersive surface waves can be used to estimate near-surface S-wave velocity. The technique consists of...
Do non-native plant species affect the shape of productivity-diversity relationships?
J.M. Drake, E.E. Cleland, M. C. Horner-Devine, E. Fleishman, C. Bowles, M. D. Smith, K. Carney, S. Emery, J. Gramling, D.B. Vandermast, J.B. Grace
2008, American Midland Naturalist (159) 55-66
The relationship between ecosystem processes and species richness is an active area of research and speculation. Both theoretical and experimental studies have been conducted in numerous ecosystems. One finding of these studies is that the shape of the relationship between productivity and species richness varies considerably among ecosystems and at...
Summer E. coli patterns and responses along 23 Chicago beaches
R.L. Whitman, M.B. Nevers
2008, Environmental Science & Technology (42) 9217-9224
Concentrations of E. coli in recreational beach water are highly variable both locally and temporally, but a broader understanding of these fluctuations may be explained through coastal observations. Currently, beach contamination study approaches tend to be site-specific underthe belief that politically delineated beaches are unique and management of beaches cannot...
Increasing shallow groundwater CO2 and limestone weathering, Konza Prairie, USA
G.L. Macpherson, J.A. Roberts, J.M. Blair, M.A. Townsend, D.A. Fowle, K. R. Beisner
2008, Geochimica et Cosmochimica Acta (72) 5581-5599
In a mid-continental North American grassland, solute concentrations in shallow, limestone-hosted groundwater and adjacent surface water cycle annually and have increased steadily over the 15-year study period, 1991-2005, inclusive. Modeled groundwater CO2, verified by measurements of recent samples, increased from 10-2.05 atm to 10-1.94 atm, about a 20% increase, from...
Modelling the impact of wind stress and river discharge on Danshuei River plume
W.-C. Liu, W.-B. Chen, R. T. Cheng, M.-H. Hsu
2008, Applied Mathematical Modelling (32) 1255-1280
A three-dimensional, time-dependent, baroclinic, hydrodynamic and salinity model, UnTRIM, was performed and applied to the Danshuei River estuarine system and adjacent coastal sea in northern Taiwan. The model forcing functions consist of tidal elevations along the open boundaries and freshwater inflows from the main stream and major tributaries in the...
Using the Model Coupling Toolkit to couple earth system models
J.C. Warner, N. Perlin, E.D. Skyllingstad
2008, Environmental Modelling and Software (23) 1240-1249
Continued advances in computational resources are providing the opportunity to operate more sophisticated numerical models. Additionally, there is an increasing demand for multidisciplinary studies that include interactions between different physical processes. Therefore there is a strong desire to develop coupled modeling systems that utilize existing models and allow efficient data...
Numerical simulation of the paleohydrology of glacial Lake Oshkosh, eastern Wisconsin, USA
J.A. Clark, K.M. Befus, T.S. Hooyer, P.W. Stewart, T.D. Shipman, C.T. Gregory, D.J. Zylstra
2008, Quaternary Research (69) 117-129
Proglacial lakes, formed during retreat of the Laurentide ice sheet, evolved quickly as outlets became ice-free and the earth deformed through glacial isostatic adjustment. With high-resolution digital elevation models (DEMs) and GIS methods, it is possible to reconstruct the evolution of surface hydrology. When a DEM deforms through time as...
Monitoring a supervolcano in repose: Heat and volatile flux at the yellostone caldera
J. B. Lowenstern, S. Hurwitz
2008, Elements (4) 35-40
Although giant calderas ("supervolcanoes") may slumber for tens of thousands of years between eruptions, their abundant earthquakes and crustal deformation reveal the potential for future upheaval. Any eventual supereruption could devastate global human populations, so these systems must be carefully scrutinized. Insight into dormant but restless calderas can be gained...
Stress tolerance in plants via habitat-adapted symbiosis
R. J. Rodriguez, J. Henson, E. Van Volkenburgh, M. Hoy, L. Wright, F. Beckwith, Y.-O. Kim, R. S. Redman
2008, ISME Journal (2) 404-416
We demonstrate that native grass species from coastal and geothermal habitats require symbiotic fungal endophytes for salt and heat tolerance, respectively. Symbiotically conferred stress tolerance is a habitat-specific phenomenon with geothermal endophytes conferring heat but not salt tolerance, and coastal endophytes conferring salt but not heat tolerance. The same fungal...
Carbon dioxide of Pu`u`O`o volcanic plume at Kilauea retrieved by AVIRIS hyperspectral data
C. Spinetti, V. Carrere, M. Fabrizia Buongiorno, A. J. Sutton, T. Elias
2008, Remote Sensing of Environment (112) 3192-3199
A remote sensing approach permits for the first time the derivation of a map of the carbon dioxide concentration in a volcanic plume. The airborne imaging remote sensing overcomes the typical difficulties associated with the ground measurements and permits rapid and large views of the volcanic processes together with the measurements of volatile components exolving...
A consistent framework for Horton regression statistics that leads to a modified Hack's law
P.R. Furey, B.M. Troutman
2008, Geomorphology (102) 603-614
A statistical framework is introduced that resolves important problems with the interpretation and use of traditional Horton regression statistics. The framework is based on a univariate regression model that leads to an alternative expression for Horton ratio, connects Horton regression statistics to distributional simple scaling, and improves the accuracy in...
Predicted effects of proposed new regulation plans on sedge/grass meadows of Lake Ontario
D.A. Wilcox, Y. Xie
2008, Journal of Great Lakes Research (34) 745-754
Previously described models for predicting the percent of Lake Ontario wetlands that would be occupied by sedge/grass-dominated meadow marsh were used to test four proposed new plans for regulation of lake levels and to make comparisons with the current plan and unregulated conditions. The models for drowned river mouth, barrier...
Application of environmental groundwater tracers at the Sulphur Bank Mercury Mine, California, USA
M.A. Engle, F. Goff, D.G. Jewett, G.J. Reller, J.B. Bauman
2008, Hydrogeology Journal (16) 559-573
Boron, chloride, sulfate, ??D, ??18O, and 3H concentrations in surface water and groundwater samples from the Sulphur Bank Mercury Mine (SBMM), California, USA were used to examine geochemical processes and provide constraints on evaporation and groundwater flow. SBMM is an abandoned sulfur and mercury mine with an underlying hydrothermal system,...
Probabilistic seismic hazard in the San Francisco Bay area based on a simplified viscoelastic cycle model of fault interactions
F. F. Pollitz, David P. Schwartz
2008, Journal of Geophysical Research B: Solid Earth (113)
We construct a viscoelastic cycle model of plate boundary deformation that includes the effect of time-dependent interseismic strain accumulation, coseismic strain release, and viscoelastic relaxation of the substrate beneath the seismogenic crust. For a given fault system, time-averaged stress changes at any point (not on a fault) are constrained to...
Quantile regression applied to spectral distance decay
D. Rocchini, B.S. Cade
2008, IEEE Geoscience and Remote Sensing Letters (5) 640-643
Remotely sensed imagery has long been recognized as a powerful support for characterizing and estimating biodiversity. Spectral distance among sites has proven to be a powerful approach for detecting species composition variability. Regression analysis of species similarity versus spectral distance allows us to quantitatively estimate the amount of turnover in...
Evolution of the Mazatzal province and the timing of the Mazatzal orogeny: Insights from U-Pb geochronology and geochemistry of igneous and metasedimentary rocks in southern New Mexico
J.M. Amato, A.O. Boullion, A.M. Serna, A.E. Sanders, G. L. Farmer, G. E. Gehrels, J. L. Wooden
2008, Geological Society of America Bulletin (120) 328-346
New U-Pb zircon ages, geochemistry, and Nd isotopic data are presented from three localities in the Paleoproterozoic Mazatzal province of southern New Mexico, United States. These data help in understanding the source regions and tectonic setting of magmatism from 1680 to 1620 Ma, the timing of the Mazatzal orogeny, the...
Effective mitigation of debris flows at Lemon Dam, La Plata County, Colorado
V.G. deWolfe, P.M. Santi, J. Ey, J.E. Gartner
2008, Geomorphology (96) 366-377
To reduce the hazards from debris flows in drainage basins burned by wildfire, erosion control measures such as construction of check dams, installation of log erosion barriers (LEBs), and spreading of straw mulch and seed are common practice. After the 2002 Missionary Ridge Fire in southwest Colorado, these measures were...
Geophysical data integration, stochastic simulation and significance analysis of groundwater responses using ANOVA in the Chicot Aquifer system, Louisiana, USA
A. Rahman, F.T.-C. Tsai, C.D. White, D.A. Carlson, C. S. Willson
2008, Hydrogeology Journal (16) 749-764
Data integration is challenging where there are different levels of support between primary and secondary data that need to be correlated in various ways. A geostatistical method is described, which integrates the hydraulic conductivity (K) measurements and electrical resistivity data to better estimate the K distribution in the Upper Chicot...
Mantle structure beneath the western edge of the Colorado Plateau
C.R. Sine, D. Wilson, W. Gao, S.P. Grand, R. Aster, J. Ni, W.S. Baldridge
2008, Geophysical Research Letters (35)
Teleseismic traveltime data are inverted for mantle Vp and Vs variations beneath a 1400 km long line of broadband seismometers extending from eastern New Mexico to western Utah. The model spans 600 km beneath the moho with resolution of ~50 km. Inversions show a sharp, large-magnitude velocity contrast across the...
Soil sail content estimation in the Yellow River delta with satellite hyperspectral data
Yongling Weng, Peng Gong, Zhi-Liang Zhu
2008, Canadian Journal of Remote Sensing (34) 259-270
Soil salinization is one of the most common land degradation processes and is a severe environmental hazard. The primary objective of this study is to investigate the potential of predicting salt content in soils with hyperspectral data acquired with EO-1 Hyperion. Both partial least-squares regression (PLSR) and conventional multiple linear...
Temporal evolution of continental lithospheric strength in actively deforming regions
W. Thatcher, F. F. Pollitz
2008, GSA Today (18) 4-11
It has been agreed for nearly a century that a strong, load-bearing outer layer of earth is required to support mountain ranges, transmit stresses to deform active regions and store elastic strain to generate earthquakes. However the dept and extent of this strong layer remain controversial. Here we use a...
Relative importance of natural disturbances and habitat degradation on snail kite population dynamics
J. Martin, W.M. Kitchens, Christopher E. Cattau, M.K. Oli
2008, Endangered Species Research (6) 25-39
Natural disturbances and habitat degradation are major factors influencing the dynamics and persistence of many wildlife populations, yet few large-scale studies have explored the relative influence of these factors on the dynamics and persistence of animal populations. We used longterm demographic data and matrix population models to examine the potential...
