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This research focuses on understanding processes controlling temporal and spatial variability in aquatic carbon fluxes in headwater streams. Headwater streams are areas of active carbon cycling because of steep topographic gradients, complex soil and vegetation patterns, and an abundance of small lakes and streams. The project will combine information from the following major components: High-frequency measurements of aquatic carbon fluxes using in-stream sensors will provide information on temporal dynamics at unprecedented resolution. A geostatistical model will be developed to characterize relations between landscape type (e.g., wetlands, forest, tundra) and aquatic C dynamics and fluxes. Variations in fluxes...
Geostatistical analyses show that the distribution of soil N, P and K is strongly associated with the presence of shrubs in desert habitats. Shrubs concentrate the biogeochemical cycle of these elements in ?islands of fertility? that are localized beneath their canopies, while adjacent barren, intershrub spaces are comparatively devoid of biotic activity. Both physical and biological processes are involved in the formation of shrub islands. Losses of semiarid grassland in favor of invading shrubs initiate these changes in the distribution of soil nutrients, which may promote the further invasion and persistence of shrubs and cause potential feedbacks between desertification and the Earth's climate system. Published...
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Bottom altitudes of the Mississippi River Valley alluvial aquifer (MRVA) were compiled from interpretations of subsurface geophysical logs (log picks) at about 10,000 boreholes and wells located throughout the Mississippi Alluvial Plain (MAP) that were available from previous investigations. Five sources of the bottom altitude data are listed numerically in the Cross Reference section (below) and correspond with the Ref_code listed in the .shp dataset. Borehole geophysical data (log picks) were referenced (corrected) to the National Elevation Dataset (NED) 10-meter digital elevation model (DEM; https://nationalmap.gov/elevation.html). Log picks that required a DEM correction of less than 20 feet were retained for...
Desert plants can influence the pattern of resources in soil resulting in small-scale enriched zones. Although conceptually simple, the shape, size, and orientation of these "resource islands" are difficult to study in detail using conventional sampling regimes. To demonstrate and alternative approach, we sampled soil under and around individual Artemisia tridentata (sagebrush), a dominant shrub of cool desert environments, and analyzed the samples with univariate statistics and geostatistics. Univariate Halvorson, Jonathan J, Harvey Bolton Jr, Jeffrey L Smith, and Richard E Rossi. ?Geostatistical analysis of resource islands under Artemisia tridentata in the shrub-steppe.? Western North American Naturalist 54,...
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Site data contained in the ScrIntrvls_AllSrcRefs_AllWellsRev.csv dataset define the top and bottom altitudes of well screens in 64,763 irrigation wells completed in the Mississippi River Valley alluvial aquifer (MRVA) that constitute a production zone in the Mississippi Alluvial Plain (MAP) extending across the midwestern and southern United States from Illinois to Louisiana. Each well entry contains an Enumerated Domain Value of the Attribute Label SrcRefNo to identify the state environmental agency that contributed to the database, and enumerated values are associated with specific state agencies by using the Enumerated Domain Value Definition. Screen-top and -bottom altitudes and land surface are referenced (corrected)...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This digital dataset contains the locations of, and links to USGS gages on the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate 50,000 square-kilometer region of California. The complex hydrologic system of the Central Valley is simulated using the USGS numerical modeling code MODFLOW-FMP (Schmidt and others, 2006b). This simulation is referred to here as the CVHM...
Tags: Alameda County, Amador County, Butte County, CV-RASA, Calaveras County, All tags...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This digital dataset contains the percentage of coarse-grained deposits in wells in 15 meter increments and the percentage of coarse-grained deposits in texture model lattice points interpolated from the well data for the Central Valley. The texture model was used as input data for the hydraulic properties portion of the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate 50,000 square-kilometer...
Tags: Alameda County, Amador County, Butte County, CV-RASA, Calaveras County, All tags...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This digital dataset contains the compaction data for 24 extensometers used for observations in the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate 50,000 square-kilometer region of California. The complex hydrologic system of the Central Valley is simulated using the USGS numerical modeling code MODFLOW-FMP (Schmid and others, 2006). This simulation is referred to here as the CVHM (Faunt, 2009)....
Tags: Alameda County, Amador County, Butte County, CV-RASA, Calaveras County, All tags...
As the population and industrial infrastructure of the United States continue to grow, the demand for water and the need to forecast water resources accurately are intensifying. Hence, the National Weather Service maintains a set of conceptual, continuous, hydrologic simulation models used to generate extended streamflow predictions, water supply outlooks and flood forecasts that are the basis for major water management and disaster emergency services decisions for the United States. A vital component of the hydrologic simulation models is a snow accumulation and ablation model that uses observed temperature and precipitation data to simulate snow cover conditions. The simulated model states are updated throughout...
Although various studies have shown that corn ethanol reduces greenhouse gas (GHG) emissions by displacing fossil fuel use, many of these studies fail to include how land-use history affects the net carbon balance through changes in soil carbon content. We evaluated the effectiveness and economic value of corn and cellulosic ethanol production for reducing net GHG emissions when produced on lands with different land-use histories, comparing these strategies with reductions achieved by set-aside programs such as the Conservation Reserve Program (CRP). Depending on prior land use, our analysis shows that C releases from the soil after planting corn for ethanol may in some cases completely offset C gains attributed...
Strontium isotope sourcing has become a common and useful method for assigning sources to archaeological artifacts. In Chaco Canyon, an Ancestral Pueblo regional center in New Mexico, previous studies using these methods have suggested that significant portion of maize and wood originate in the Chuska Mountains region, 75 km to the East. In the present manuscript, these results were tested using both frequentist methods (to determine if geochemical sources can truly be differentiated) and Bayesian methods (to address uncertainty in geochemical source attribution). It was found that Chaco Canyon and the Chuska Mountain region are not easily distinguishable based on radiogenic strontium isotope values. The strontium...
Categories: Publication; Types: Citation; Tags: Agriculture, Anthropology, Archaeology, Archaeometry, Atoms, All tags...
The R factor, an index of rainfall erosivity in the universal soil loss equation (USLE), fundamentally governs water related soil loss from agricultural plots and is based on well studied empirical relations. Soil particles and adsorbed contaminants from agricultural runoff inevitably end up in water-courses and ultimately the Great Lakes system, disturbing natural habitat, reducing water clarity and quality. We here use over 22 years of records containing hourly precipitation recordings for 453 meteorological-recording sites in Ontario, southwestern Quebec, Michigan, Ohio, Pennsylvania, and New York to estimate the R factor surrounding the lower Laurentian Great Lakes. We generate annual and monthly R factor maps...
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The U.S. Geological Survey (USGS) used the Borehole data to characterize the hydrogeology in the Central Valley of California for the updated Central Valley Hydrologic Model (CVHM2). These data encompass the inputs and outputs for the three-dimensional (3D) hydrogeologic Framework for the Central Valley, California, a part of the Central Valley Hydraulic Framework version 2 (CVHM2) project. These files include the shapefiles with flow layers (Flow_model_grid.zip), a scatter dataset of the modeled Central Valley (PercentCoarse_CV_50ft.csv), and the well log information and kriging parameters for the Central Valley (Kriging_Table.xlxs).
Categories: Data; Tags: Alameda County, Amador County, Butte County, Calaveras County, California, All tags...
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These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. Abstract: This digital dataset contains the virtual wells used for pumpage for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate 50,000 square-kilometer region of California. The complex hydrologic system of the Central Valley is simulated using the U.S. Geological Survey (USGS) numerical modeling code MODFLOW-FMP (Schmid and others, 2006). This simulation is referred to here as the CVHM (Faunt,...
Categories: pre-SM502.8; Tags: Alameda County, Amador County, Butte County, CV-RASA, Calaveras County, All tags...
Rocky Mountain National Park (RMNP), Colorado, USA, contains a diversity of plant species. However, many exotic plant species have become established, potentially impacting the structure and function of native plant communities. Our goal was to quantify patterns of exotic plant species in relation to native plant species, soil characteristics, and other abiotic factors that may indicate or predict their establishment and success. Our research approach for field data collection was based on a field plot design called the pixel nested plot. The pixel nested plot provides a link to multi-phase and multi-scale spatial modeling-mapping techniques that can be used to estimate total species richness and patterns of plant...
Desert plants can influence the pattern of resources in soil resulting in small-scale enriched zones. Although conceptually simple, the shape, size, and orientation of these "resource islands" are difficult to study in detail using conventional sampling regimes. To demonstrate and alternative approach, we sampled soil under and around individual Artemisia tridentata (sagebrush), a dominant shrub of cool desert environments, and analyzed the samples with univariate statistics and geostatistics. Univariate statistics revealed that soil variables like total inorganic-N, soluble-C, and microbial biomass-C were distributed with highest mean values within about 25 cm of the plant axis and significantly lower mean values...
Although various studies have shown that corn ethanol reduces greenhouse gas (GHG) emissions by displacing fossil fuel use, many of these studies fail to include how land-use history affects the net carbon balance through changes in soil carbon content. We evaluated the effectiveness and economic value of corn and cellulosic ethanol production for reducing net GHG emissions when produced on lands with different land-use histories, comparing these strategies with reductions achieved by set-aside programs such as the Conservation Reserve Program (CRP). Depending on prior land use, our analysis shows that C releases from the soil after planting corn for ethanol may in some cases completely offset C gains attributed...
Although various studies have shown that corn ethanol reduces greenhouse gas (GHG) emissions by displacing fossil fuel use, many of these studies fail to include how land-use history affects the net carbon balance through changes in soil carbon content. We evaluated the effectiveness and economic value of corn and cellulosic ethanol production for reducing net GHG emissions when produced on lands with different land-use histories, comparing these strategies with reductions achieved by set-aside programs such as the Conservation Reserve Program (CRP). Depending on prior land use, our analysis shows that C releases from the soil after planting corn for ethanol may in some cases completely offset C gains attributed...
    map background search result map search result map Headwater C fluxes Digital surfaces of the bottom altitude and thickness of the Mississippi River Valley alluvial aquifer and site data within the Mississippi Alluvial Plain project region Digital surfaces and site data of well-screen top and bottom altitudes defining the irrigation production zone of the Mississippi River Valley alluvial aquifer within the Mississippi Alluvial Plain project region Central Valley Hydrologic Model version 2 (CVHM2): Three-Dimensional Framework Model Measured compaction for 24 extensometers in the Central Valley U.S. Geological Survey Stream Gages located in the Central Valley, California Virtual wells used for pumpage for the Central Valley Hydrologic Model (CVHM) Percent Coarse in wells in 15 meter increments and Texture Model Percent Coarse at Lattice Points for the Central Valley from Faunt (2009) Headwater C fluxes U.S. Geological Survey Stream Gages located in the Central Valley, California Virtual wells used for pumpage for the Central Valley Hydrologic Model (CVHM) Central Valley Hydrologic Model version 2 (CVHM2): Three-Dimensional Framework Model Measured compaction for 24 extensometers in the Central Valley Percent Coarse in wells in 15 meter increments and Texture Model Percent Coarse at Lattice Points for the Central Valley from Faunt (2009) Digital surfaces of the bottom altitude and thickness of the Mississippi River Valley alluvial aquifer and site data within the Mississippi Alluvial Plain project region Digital surfaces and site data of well-screen top and bottom altitudes defining the irrigation production zone of the Mississippi River Valley alluvial aquifer within the Mississippi Alluvial Plain project region