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At least 1,585 records · Page 88Linked to original sources
USGS2000

Creating a standardized watersheds database for the lower Rio Grande/Rio Bravo, Texas

This report describes the creation of a large-scale watershed database for the lower Rio Grande/Rio Bravo Basin in Texas. The watershed database includes watersheds delineated to all 1:24,000-scale mapped stream confluences and other hydrologically significant points, selected watershed characteristics, and hydrologic derivative datasets. Computer technology allows generation of preliminary watershed boundaries in a fraction of the time needed for manual methods. This automated process reduces development time and results in quality improvements in watershed boundaries and characteristics. These data can then be compiled in a permanent database, eliminating the time-consuming step of data creation at the beginning of a project and providing a stable base dataset that can give users greater confidence when further subdividing watersheds. A standardized dataset of watershed characteristics is a valuable contribution to the understanding and management of natural resources. Vertical integration of the input datasets used to automatically generate watershed boundaries is crucial to the success of such an effort. The optimum situation would be to use the digital orthophoto quadrangles as the source of all the input datasets. While the hydrographic data from the digital line graphs can be revised to match the digital orthophoto quadrangles, hypsography data cannot be revised to match the digital orthophoto quadrangles. Revised hydrography from the digital orthophoto quadrangle should be used to create an updated digital elevation model that incorporates the stream channels as revised from the digital orthophoto quadrangle. Computer-generated, standardized watersheds that are vertically integrated with existing digital line graph hydrographic data will continue to be difficult to create until revisions can be made to existing source datasets. Until such time, manual editing will be necessary to make adjustments for man-made features and changes in the natural landscape that are not reflected in the digital elevation model data.

Texas↗
USGS2023

Sequestration and reoxidation of chromium in experimental microcosms

Groundwater containing hexavalent chromium, Cr(VI), downgradient from the Pacific Gas and Electric Company (PG&E) Hinkley compressor station in the Mojave Desert, 80 miles northeast of Los Angeles, California, is undergoing bioremediation using added ethanol as a reductant in a volume of the aquifer defined as the in situ reactive zone (IRZ). This treatment reduces Cr(VI) to trivalent chromium, Cr(III), which is rapidly sequestered by sorption to aquifer particle surfaces and by co-precipitation within iron (Fe) or manganese (Mn) bearing minerals forming in place as reduction proceeds. Successful mitigation of the Cr(VI) plume is projected to require 10–95 years, at which time bioremediation with ethanol will likely cease. This projection assumes that Cr(VI) removal is permanent and that no Cr(III) will oxidize back to Cr(VI) in the event of changing hydrologic conditions that may cause oxygen-rich water to re-enter the IRZ. Laboratory microcosm experiments were done to explore the process of reductive sequestration of Cr(VI) to Cr(III) and the potential for reoxidation of Cr(III) to Cr(VI). In reductive sequestration experiments, batch microcosms were prepared with aquifer materials collected from sites upgradient of the Cr(VI) regulatory plume. Control microcosms were prepared using Fe- and Mn-coated quartz sand. Unfiltered Mojave River groundwater containing an added tracer of isotopically labeled chromium-50 were reacted with microcosm materials for up to 2 years; during this time, bio-reduction was stimulated by repeated additions of diluted ethanol to maintain reduced conditions within appropriate ranges, avoiding sulfate reducing or methanogenic conditions as much as possible while mimicking field conditions. Analysis of chromium-50, Fe, and Mn obtained by sequential extraction from microcosms harvested (incubation terminated and microcosm contents analyzed) at various times showed that some aqueous chromium (Cr) was sorbed to particle surfaces within hours; reduction to Cr(III) and incorporation into amorphous and crystalline solid phases occurred during the next few months. Amorphous Cr-containing fractions included Fe and Mn hydroxides and organic matter. Ultimately, most of the chromium-50 tracer was present in the less reactive crystalline phase. However, Fe and Mn were broadly distributed at later stages of reduction, and both were spatially co-located with Cr on a micrometer (μm) scale. Solid-phase data collected using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and X-ray absorption spectroscopy (XAS) indicated that some Cr(III) was associated with mixed valence Fe oxides like magnetite and Fe-Mn oxides like jacobsite. Additionally, Cr(III) was observed within several μm of Fe and Mn embedded in clays and in mineral coatings. To evaluate the potential for reoxidation of Cr(III) to Cr(VI), additional batch microcosms of aquifer materials and mixtures of Fe- and Mn-coated sand were first reduced for more than 1 year and subsequently oxidized for almost 2 years. Hexavalent chromium was formed and was available for release to the aqueous phase during oxidation of all materials; however, the timing and amount of Cr(VI) formed and released varied among substrates. Artificial substrates containing more Mn produced more Cr(VI). Site material characteristic of recent Mojave River deposits contained within the IRZ produced the least Cr(VI) during oxidation, while site materials composed of older Mojave River aquifer material (containing more Mn) produced more Cr(VI). Site material collected from within the IRZ contained more Cr but produced an intermediate amount of Cr(VI) following oxidation. The combined results of microcosm chemistry and solid-phase analyses showed that the nature and locus of Cr(III) sequestration influenced its vulnerability to reoxidation to Cr(VI). It was concluded that co-location of Cr with Mn at later stages of reduction influenced the susceptibility of Cr(III) to reoxidation in microcosms. Reoxidation of Cr(III) to Cr(VI) was observed in experiments with previously reduced material after just 14 days exposure to oxygen. As much as 10 percent of added Cr was oxidized to Cr(VI) in microcosms prepared using recent Mojave River aquifer material, and as much as 20 percent of added Cr was oxidized to Cr(VI) in microcosms prepared using older Mojave River aquifer material. Less Cr(VI) (less than 3 percent of Cr added before reduction) was released to the aqueous phase, and this release occurred following longer oxygen exposure. Site managers may need to plan for long-term monitoring and the possibility of active maintenance of anoxic conditions within the IRZ to ensure permanent sequestration of Cr after bioremediation with ethanol ceases.

California↗
USGS2024

Groundwater model of the Harney Basin, southeastern Oregon

Groundwater development, mainly for large-scale irrigation, has increased substantially in the Harney Basin of southeastern Oregon since 2010. Concurrently, some areas of the basin experienced groundwater-level declines of more than 100 feet, and some shallow wells have gone dry. The Oregon Water Resources Department has limited new groundwater development in the basin until an improved understanding of the groundwater-flow system is available. The groundwater resources report by Gingerich and others (2022, U.S. Geological Survey Scientific Investigations Report 2021–5103, https://doi.org/10.3133/sir20215103 ) provides that understanding. This report describes the development of a numerical groundwater-flow model that can be used as a tool to help improve that understanding. The Harney Basin Groundwater Model was developed using the finite-difference groundwater-modeling software U.S. Geological Survey modular finite-difference groundwater-flow model (MODFLOW 6) and associated Python pre- and post-processing routines. The groundwater model encompasses the entire 5,240-square-mile Harney Basin and adjacent areas and is calibrated to the hydrologic conditions from 1930 to 2018. The model has a uniform grid consisting of 78,064 nearly square cells, each covering 2,005 by 2,007 feet (about 92 acres) and has 10 layers (780,640 total cells) representing the vertical distribution of hydrogeologic units. The results from the calibrated model simulations indicate that groundwater pumpage exceeded recharge since about the mid-1980s, resulting in an estimated net cumulative depletion of groundwater storage (discharge minus recharge) of about 840,000 acre-feet and also indicated declines in groundwater evapotranspiration and spring and stream discharge. Model simulations show as much as 100 feet of groundwater-level decline in some areas and more than 40 feet of decline in widespread areas in recent decades. Model simulations are consistent with field observations of groundwater levels through time.

Oregon↗
USGS2004

Use of submersible pressure transducers in water-resources investigations

Submersible pressure transducers, developed in the early 1960s, have made the collection of water-level and pressure data much more convenient than former methods. Submersible pressure transducers, when combined with electronic data recorders have made it possible to collect continuous or nearly continuous water-level or pressure data from wells, piezometers, soil-moisture tensiometers, and surface water gages. These more frequent measurements have led to an improved understanding of the hydraulic processes in streams, soils, and aquifers. This manual describes the operational theory behind submersible pressure transducers and provides information about their use in hydrologic investigations conducted by the U.S. Geological Survey.

Techniques of Water-Resources Investigations↗
USGS2007

Vision for a worldwide fluvial-sediment information network

The nations of the world suffer both from the deleterious effects of some natural and human-altered fluxes of fluvial sediment and a lack of consistent and reliable information on the temporal and spatial occurrence of fluvial sediments. Decades ago, this difficulty was unavoidable due to a lack of understanding of the magnitude and scope of environmental influences exerted by fluvial sediment coupled with a dearth of tools for monitoring and studying the data. Such is no longer the case. Fluvial sediment has a broad influence on the environment and humanity. Data needs that were once limited primarily to reservoir and channel maintenance now include issues associated with public water supply; contaminated sediment management; productivity of agricultural lands; stream restoration and watershed health; in-stream biotic stability; post-wildfire channel morphology; dam decommissioning, rehabilitation, or removal; and legal requirements for sediment management (Gray and Glysson, 2005). The adverse effects of poorly managed or unmanaged sediment movement related to these and other issues are well-known qualitatively, and in some cases quantitatively. For example, physical, chemical, and biological damages attributable to fluvial sediment in North America alone are now estimated to range between $20 billion and $50 billion annually (Pimental and others, 1995; Osterkamp and others, 1998; 2004). Capabilities for monitoring, analyzing, storing, and sharing fluvial-sediment data have been developed and, in many cases, are sufficiently mature for consideration for global utilization. Hence, there is not only a strong and expanding need for a global effort to gauge and understand fluvial-sediment characteristics and processes better, but the knowledge and tools to achieve these ends are largely available and ready for their applicability to be evaluated. Given the increasing importance of erosion and sediment processes for water-resources management, an International Sedimentation Initiative (ISI, 2007a), under the United Nations Educational, Scientific, and Cultural Organization’s International Hydrologic Programme (IHP, 2007) was adopted in 2004. The ISI, the focus of which is on sustainable water-resources management on the global scale, features six major activities and projects, which are listed as part of the section entitled, “Relation of the WoFSIN concept to the thrusts of the International Sedimentation Initiative,” that precedes the “Conclusions” section of this paper. Based on the need for more, and more consistent and reliable fluvial-sediment information and on the existence of the ISI and other international and national sediment programs, we envision the need for a Worldwide Fluvial Sediment-Information Network (WoFSIN) with a focus on data acquisition, storage, and dissemination globally. Envisioned components of a WoFSIN, administered largely via the Internet and relying mostly on the benefits derived from existing resources and programs, follow that summary. The goal of the WoFSIN is to maximize the availability and usefulness of the world’s historical and current fluvial-sediment and ancillary data through collaboration with existing programs so as to require few additional resources in the long-term. Thus, the WoFSIN concept was developed recognizing that informed resource management is predicated on the availability of adequate and reliable information. The WoFSIN is described in the ensuing sections in stand-alone fashion, followed by a section that describes the complementary aspects of the WoFSIN and the International Sediment Initiative. Thus, our first objective is to describe the fundamental components of a WoFSIN. Our second objective is to identify overlap or gaps between the WoFSIN and ISI concepts that might be useful in refining the ISI’s ability to meet its global mission to develop decision support for sediment management at the global scale more fully, cost-effectively, and (or) with enhanced quality.

Conference Paper↗
USGS1995

Selected hydrologic data for urban watersheds in South Carolina, 1983-90

Rainfall and streamflow data were collected at 23 gaging stations located in urban watersheds in South Carolina from 1983-90. The site selection process and the instrumentation used to collect the data are described. A compilation of rainfall and streamflow data in graphic and tabular form for seven selected events at each gaging station are presented. A gaging-station description and a listing of certain streamflow and basin characteristics also are included.

South Carolina↗
USGS1989

US Geological Survey Toxic Substances Hydrology Program: Proceedings of the technical meeting, Phoenix, Arizona, September 26-30, 1988

Crude oil floating at the surface of a shallow aquifer of glacial outwash, near Bemidji, Minnesota, is altered by geochemical processes. Hydrocarbons from the oil are attenuated by several reactions that include aerobic and anaerobic microbial degradation. These degradation reactions result in the development of geochemical facies in the shallow groundwater system. Groundwater most affected by the presence of organic compounds is anoxic, and concentrations of methane, dissolved organic carbon, and total inorganic are high--0.76 millimole/L, 2.9 millimole/L, and 12.3 millimole/L, respectively. The concentrations of chemical species and delta-(13)C isotope values indicate that the plume near the oil lens has become progressively more reducing. Over a 4-year period (1984 through 1987), the concentrations of methane and iron have increased by a factor of > 25. The data suggest that sequential degradation occurs, as predicted by thermo-dynamics: manganese is reduced before iron is reduced, which occurs before methanogenesis. These data provide field evidence that reduction of iron and manganese is an important mechanism of decomposition of organic matter in aquifers. The delta-(13)C values of inorganic carbon of the native groundwater range from -12 ppt to -15 ppt as a result of mixing of soil CO2 with CO2 from the dissolution of carbonates. Non methanogenic biodegradation of oil constituents adds isotopically light CO2 to the groundwater because the oil has a delta-(13)C value of 28 ppt. The delta-(13)C value of inorganic carbon in the reducing zone have become progressively heavier from 1985 through 1987. The maximum change occurs 15 m downgradient from the oil lens, where the delta-(13)C values increased from -21.6 ppt to -5.35 ppt. This change indicates that the plume has become more reducing and methanogenic over time.

Water-Resources Investigations Report↗
USGS2017

Sediment deposition and sources into a Mississippi River floodplain lake; Catahoula Lake, Louisiana

Floodplain lakes are important wetlands on many lowland floodplains of the world but depressional floodplain lakes are rare in the Mississippi River Alluvial Valley. One of the largest is Catahoula Lake, which has existed with seasonally fluctuating water levels for several thousand years but is now in an increasingly hydrologically altered floodplain. Woody vegetation has been encroaching into the lake bed and the rate of this expansion has increased since major human hydrologic modifications, such as channelization, levee construction, and dredging for improvement of navigation, but it remains unknown what role those modifications may have played in altering lake sedimentation processes. Profiles of thirteen 137 Cs sediment cores indicate sedimentation has been about 0.26 cm y − 1 over the past 60 years and has been near this rate since land use changes began about 200 years ago ( 210 Pb, and 14 C in Tedford, 2009). Carbon sequestration was low (10.4 g m − 2 y − 1 ), likely because annual drying promotes mineralization and export. Elemental composition (high Zr and Ti and low Ca and K) and low pH of recent (<~60 y) or surface sediments suggest Gulf Coastal Plain origin, but below the recent sediment deposits, 51% of sediment profiles showed influence of Mississippi River alluvium, rich in base cations such as K + , Ca 2 + , and Mg 2 + . The recent shift to dominance of Coastal Plain sediments on the lake-bed surface suggests hydrologic modification has disconnected the lake from sediment-bearing flows from the Mississippi River. Compared to its condition prior to hydrologic alterations that intensified in the 1930s, Catahoula Lake is about 15 cm shallower and surficial sediments are more acidic. Although these results are not sufficient to attribute ecological changes directly to sedimentological changes, it is likely the altered sedimentary and hydrologic environment is contributing to the increased dominance of woody vegetation.

Louisiana↗
USGS2009

Forecasting the combined effects of urbanization and climate change on stream ecosystems: from impacts to management options

Streams collect runoff, heat, and sediment from their watersheds, making them highly vulnerable to anthropogenic disturbances such as urbanization and climate change. Forecasting the effects of these disturbances using process-based models is critical to identifying the form and magnitude of likely impacts. Here, we integrate a new biotic model with four previously developed physical models (downscaled climate projections, stream hydrology, geomorphology, and water temperature) to predict how stream fish growth and reproduction will most probably respond to shifts in climate and urbanization over the next several decades. The biotic submodel couples dynamics in fish populations and habitat suitability to predict fish assemblage composition, based on readily available biotic information (preferences for habitat, temperature, and food, and characteristics of spawning) and day-to-day variability in stream conditions. We illustrate the model using Piedmont headwater streams in the Chesapeake Bay watershed of the USA, projecting ten scenarios: Baseline (low urbanization; no on-going construction; and present-day climate); one Urbanization scenario (higher impervious surface, lower forest cover, significant construction activity); four future climate change scenarios [Hadley CM3 and Parallel Climate Models under medium-high (A2) and medium-low (B2) emissions scenarios]; and the same four climate change scenarios plus Urbanization. Urbanization alone depressed growth or reproduction of 8 of 39 species, while climate change alone depressed 22 to 29 species. Almost every recreationally important species (i.e. trouts, basses, sunfishes) and six of the ten currently most common species were predicted to be significantly stressed. The combined effect of climate change and urbanization on adult growth was sometimes large compared to the effect of either stressor alone. Thus, the model predicts considerable change in fish assemblage composition, including loss of diversity. Synthesis and applications . The interaction of climate change and urban growth may entail significant reconfiguring of headwater streams, including a loss of ecosystem structure and services, which will be more costly than climate change alone. On local scales, stakeholders cannot control climate drivers but they can mitigate stream impacts via careful land use. Therefore, to conserve stream ecosystems, we recommend that proactive measures be taken to insure against species loss or severe population declines. Delays will inevitably exacerbate the impacts of both climate change and urbanization on headwater systems.

Journal of Applied Ecology↗
USGS2010

Evaluating effects of potential changes in streamflow regime on fish and aquatic-invertebrate assemblages in the New Jersey Pinelands

Changes in water demand associated with population growth and changes in land-use practices in the Pinelands region of southern New Jersey will have a direct effect on stream hydrology. The most pronounced and measurable hydrologic effect is likely to be flow reductions associated with increasing water extraction. Because water-supply needs will continue to grow along with population in the Pinelands area, the goal of maintaining a sustainable balance between the availability of water to protect existing aquatic assemblages while conserving the surficial aquifer for long-term support of human water use needs to be addressed. Although many aquatic fauna have shown resilience and resistance to short-term changes in flows associated with water withdrawals, sustained effects associated with ongoing water-development processes are not well understood. In this study, the U.S. Geological Survey sampled forty-three 100-meter-long stream reaches during high- and low-flow periods across a designed hydrologic gradient ranging from small- (4.1 square kilometers (1.6 square miles)) to medium- (66.3 square kilometers (25.6 square miles)) sized Pinelands stream basins. This design, which uses basin size as a surrogate for water availability, provided an opportunity to evaluate the possible effects of potential variation in stream hydrology on fish and aquatic-invertebrate assemblage response in New Jersey Pinelands streams where future water extraction is expected based on known build-out scenarios. Multiple-regression models derived from extracted non-metric multidimensional scaling axis scores of fish and aquatic invertebrates indicate that some variability in aquatic-assemblage composition across the hydrologic gradient is associated with anthropogenic disturbance, such as urbanization, changes in stream chemistry, and concomitant changes in high-flow runoff patterns. To account for such underlying effects in the study models, any flow parameter or assemblage attribute that was found to be significantly correlated (|rho| = 0.5000) to known anthropogenic drivers (for example, the amount of urbanization in the basin) was eliminated from analysis. A reduced set of low- and annual-flow hydrologic variables, found to be unrelated to anthropogenic influences, was used to develop assemblage-response models. Many linear (monotonic) and curvilinear bivariate flow-ecology response models were developed for fish and invertebrate assemblages. For example, the duration and magnitude of low-flow events were significant predictors of invertebrate-assemblage complexity (for example, invertebrate-species richness, Plecoptera richness, and Ephemeroptera abundance); however, response models between flow attributes and fish-assemblage structure were, in all cases, more poorly fit. Annual flow variability also was important, especially variability across mean minimum monthly flows and annual mean streamflow. In general, all response models followed upward or downward trends that would be expected given hydrologic changes in Pinelands streams. This study demonstrates that the structural and functional response of aquatic assemblages of the Pinelands ecosystem resulting from changes in water-use practices associated with population growth and increased water extraction may be predictable.

Scientific Investigations Report↗
USGS1988

Climate and ephemeral-stream processes: Twentieth-century geomorphology and alluvial stratigraphy of the Little Colorado River, Arizona

During the first 40 years of the twentieth century, erosion was the dominant geomorphic process affecting the morphology of the Little Colorado River channel. The discharge regimen was one of frequent large floods and high annual discharge that created a wide sandy channel free of vegetation. In the 1940s and early 1950s, average annual precipitation declined, reducing annual discharge to about 57% of that of the preceding period as well as reducing the frequency of large floods. The channel adjusted to the new hydrologic regimen by reducing its width. Parts of the channel were frequently dry, and riparian vegetation, primarily nonnative salt cedar, became established on the higher channel surfaces. Precipitation and discharge thereafter increased and aggradation by overbank deposition was the primary geomorphic process, as indicated by accretion of 2 to 5 m of flood-plain alluvium between 1952 and 1978. Events of 1980, however, suggest that the flood plain has ceased to accrete, although climate has not fluctuated. The flood plain has probably reached a critical height above the channel, beyond which further accretion is unlikely under the existing discharge regimen. The recent history of the Little Colorado broadly suggests that flood-plain development was initiated by climatically induced hydrologic fluctuations. Flood-plain deposits in the stratigraphic column of such ephemeral streams may record repeated adjustments to altered hydrologic conditions.

Arizona, New Mexico↗
USGS1996

Factors affecting phosphorus transport at a conventionally-farmed site in Lancaster County, Pennsylvania, 1992-95

The U.S. Geological Survey and the Bureau of Land and Water Conservation of the Pennsylvania Department of Environmental Protection conducted a cooperative study to determine the effects of manure application and antecedent soil-phosphorus concentrations on the transport of phosphorus from the soil of a typical farm site in Lancaster County, Pa., from September 1992 to March 1995. The relation between concentrations of soil phosphorus and phosphorus transport needs to be identified because excessive phosphorus concentrations in surface-water bodies promote eutrophication. The objective of the study was to quantify and determine the significance of chemical, physical, and hydrologic factors that affected phosphorus transport. Three study plots less than 1 acre in size were tilled and planted in silage corn. Phosphorus in the form of liquid swine and dairy manure was injected to a depth of 6-8 inches on two of the three study plots in May 1993 and May 1994. Plot 1 received no inputs of phosphorus from manure while plots 2 and 3 received an average of 56 and 126 kilograms of phosphorus per acre, respectively, from the two manure applications. No other fertilizer was applied to any of the study plots. From March 30, 1993, through December 31, 1993, and March 10, 1994, through August 31, 1994 (the study period), phosphorus and selected cations were measured in precipitation, manure, soil, surface runoff, subsurface flow (at 18 inches below land surface), and corn plants before harvest. All storm events that yielded surface runoff and subsurface flow were sampled. Surface runoff was analyzed for dissolved (filtered through a 0.45-micron filter) and total concentrations. Subsurface flow was only analyzed for dissolved constituents. Laboratory soil-flask experiments and geochemical modeling were conducted to determine the maximum phosphate retention capacity of sampled soils after manure applications and primary mineralogic controls in the soils that affect phosphate equilibrium processes. Physical characteristics, such as particle-size distributions in soil, the suspended sediment and particle-size distribution in surface runoff, and surface topography, were quantified. Hydrologic characteristics, such as precipitation intensity and duration, volumes of surface runoff, and infiltration rates of soil, were also monitored during the study period. Volumes of surface runoff differed by plot. Volumes of surface runoff measured during the study period from plots 1 (0.43 acres), 2 (0.23 acres), and 3 (0.28 acres) were 350,000, 350,000, and 750,000 liters per acre, respectively. About 90 percent of the volume of surface runoff occurred after October 1993 because of the lack of intense precipitation from March 30, 1993, through November 30, 1993. For any one precipitation amount, volumes of surface runoff increased with an increase in the maximum intensity of precipitation and decreased with an increase in storm duration. The significantly higher volume of surface runoff for plot 3 relative to plots 1 and 2 was probably caused by lower infiltration rates on plot 3. Soil concentrations of plant-available phosphorus (PAP) for each study plot were high (31-60 parts per million) to excessive (greater than 60 parts per million) for each depth interval (0-6, 6-12, and 12- 24 inches) and sampling period except for some samples collected at depths of 12-24 inches. The high levels of PAP before manure applications made it difficult to detect any changes in the concentration of soil PAP caused by manure applications. Manure applications to the study area prior to this study resulted in relatively high concentrations of soil PAP; however, the manure applications to plot 3 during the study period did cause an increase in the soil concentration of PAP after the second manure application. The percentages of total phosphorus in plant-available and inorganic forms were about 5 and 80 percent, respectively, in the 0-24--inch depth interval of soil on the study plots. Concentrations of total phosphorus on sand, silt, and clay particles from soil were 700, 1,000, and 3,400 parts per million, respectively. About 70 percent of the total mass of phosphorus in soil to a depth of 24 inches was associated with silt and clay particles. Soil-flask experiments indicated that soils from the study plots were not saturated with respect to phosphorus. Soils had the capacity to retain 694 to 1,160 milligrams of phosphorus per kilogram of soil. The measured retention capacity probably exceeded the actual retention capacity of soil because laboratory conditions optimized the contact time between soil and test solutions. Geochemical modeling indicated that the primary mineralogical controls on the concentration of dissolved phosphorus in surface runoff and subsurface flow were aluminum and iron oxides and strengite (if it exists). Aluminum and iron oxides bind phosphate in solution and strengite is an iron-phosphate mineral. The mineralization of organic phosphorus into dissolved inorganic forms could also supply phosphorus to surface runoff and subsurface flow. Phosphorus inputs to the plots during the study period were from precipitation and manure. Phosphorus inputs from precipitation were negligible. The loads of phosphorus to the plots from manure applications in May 1993 and May 1994 were 112 and 251 kilograms per acre for plots 2 and 3, respectively; about 60 percent of the load occurred in 1994. Phosphorus outputs in surface runoff differed between study plots. The cumulative yields of total phosphorus during the study period for plots 1, 2, and 3 were 1.12, 1.24, and 1.69 kilograms per acre, respectively. Differences between plots were primarily evident for dissolved yields of phosphorus. The percentage of the total phosphorus output in surface runoff that was in the dissolved phase varied from 6 percent for plot 1 to 26 percent for plot 3. The cumulative yields of dissolved phosphorus from plots 2 and 3 were 135 and 500 percent greater, respectively, than the dissolved yield from plot 1. Even though volumes of surface runoff were different on the plots, the primary cause of the difference between plots in the yield of dissolved phosphorus in surface runoff was differences in the concentration of dissolved phosphorus. After the second manure application, concentrations of dissolved phosphorus in surface runoff on plots 2 and 3 were significantly higher than the concentration for plot 1. An increase in the concentration of dissolved phosphorus in subsurface flow from plots 2 and 3 was measured after manure applications. The mean concentrations of dissolved phosphorus in subsurface flow after the first manure application were 0.29, 0.57, and 1.45 milligrams per liter of phosphorus for plots 1, 2, and 3, respectively. The loss of dissolved phosphorus in surface runoff was related to the soil concentration of PAP. The model relating dissolved phosphorus in surface runoff to soil PAP indicated that concentrations of dissolved phosphorus in surface runoff would exceed 0.1 milligram per liter if soil concentrations of PAP exceeded 9 parts per million; this PAP concentration was exceeded by each study plot. Over 50 percent of the variation of dissolved phosphorus in surface runoff was explained by soil concentrations of PAP in the 0-6-inch depth interval. The loss of suspended phosphorus in surface runoff was primarily affected by the particle-size distribution of suspended sediment in surface runoff. Surface runoff was enriched with fines relative to the soil matrix. Generally, over 90 percent of sediment in runoff was comprised of silt and clay particles; only 50-60 percent of particle sizes from the intact soil matrix were in the silt- to clay-size range. Concentrations of suspended phosphorus in surface runoff were not significantly related to soil concentrations of total phosphorus in the 0-6-inch depth interval. Concentrations of dissolved phosphorus in subsurface flow were also related to soil concentrations of PAP. The relation indicated that dissolved concentrations of phosphorus in subsurface flow would exceed 0.1 milligram per liter if soil concentrations of PAP in the 0-6-inch depth interval of soil were greater than 49 parts per million; this PAP concentration was exceeded by each study plot. The significant relation of high concentrations of dissolved phosphorus in water to soil concentrations of PAP indicated that soils with comparable concentrations of soil PAP would be potential sources of dissolved phosphorus to surface water and subsurface water tables. The percentage of the total phosphorus lost from a system in the dissolved form increased as soil concentrations of PAP increased. This indicates that best-management practices to reduce phosphorus losses from this system not only need to target suspended forms of phosphorus but also dissolved forms. Practices aimed at reducing the loss of dissolved phosphorus from the system increase in importance with an increase in soil concentrations of PAP.

Water-Resources Investigations Report↗
USGS1985

Effects of flood control alternatives on fish and wildlife resources of the Malheur-Harney lakes basin

Malheur Lake is the largest freshwater marsh in the western contiguous United States and is one of the main management units of the Malheur National Wildlife Refuge in southeastern Oregon. The marsh provides excellent waterfowl production habitat as well as vital migration habitats for birds in the Pacific flyway. Water shortages have typically been a problem in this semiarid area; however, record snowfalls and cool summers have recently caused Malheur Lake to rise to its highest level in recorded history. This has resulted in the loss of approximately 57,000 acres of important wildlife habitat as well as extensive flooding of local ranches, roads, and railroad lines. Because of the importance of the Refuge, any water management plan for the Malheur-Harney Lakes Basin needs to consider the impact of management alternatives on the hydrology of Malheur Lake. The facilitated modeling workshop described in this report was conducted January 14-18, 1985, under the joint sponsorship of the Portland Ecological Services Field Office and the Malheur National Wildlife Refuge, Region 1, U.S. Fish and Wildlife Service (FWS). The Portland Field Office is responsible for FWS reporting requirements on Federal water resource projects while the Refuge staff has management responsibility for much of the land affected by high water levels in the Malheur-Harney Lakes Basin. The primary objective of the workshop was to begin gathering and analyzing information concerning potential fish and wildlife impacts, needs, and opportunities associated with proposed U.S. Army Corps of Engineers (COE) flood control alternatives for Malheur Lake. The workshop was structured around the formulation of a computer model that would simulate the hydrologic effects of the various alternatives and any concommitant changes in vegetation communities and wildlife use patterns. The simulation model is composed of three connected submodels. The Hydrology submodel calculates changes in lake volume, elevation, and surface area, as well as changes in water quality, that result from the proposed water management projects (upstream storage, upstream diversions, drainage canals) and the no action alternative. The Vegetation submodel determines associated changes in the areal extent of wetland and upland vegetation communities. Finally, the Wildlife submodel calculates indices of abundance or habitat suitability for colonial nesting birds (great egret, double-crested cormorant, white-faced ibis), greater sandhill crane, diving ducks, tundra swan, dabbling ducks, and Canada goose based on hydrologic and vegetation conditions. The model represents the Malheur-Harney Lakes Basin, but provides water quantity and quality indicators associated with additional flows that might occur in the Malheur River Basin. Several management scenarios, representing various flood control alternatives and assumptions concerning future runoff, were run to analyze model behavior. Scenario results are not intended as an analysis of all potential management actions or assumptions concerning future runoff. Rather, they demonstrate the type of analysis that could be conducted if the model was sufficiently refined and tested. Early in a model development project, the process of building the model is usually of greater benefit than the model itself. The model building process stimulates interaction among agencies, assists in integrating existing information, and helps identify research needs. These benefits usually accrue even in the absence of real predictive power in the resulting model. This workshop initiated interaction among the primary State and Federal resource and development agencies in a nonadversarial forum. The exchange of information and expertise among agencies provided the FWS with the best information currently available for use in the Planning Aid Letter it will develop at the Reconnaissance state of the COE study. If the COE subsequently initiates a Feasability Study, this information will be refined further and will aid the FWS in preparing its Coordination Act Report on any flood control alternative proposed by the COE. The model building and testing process also helped identify model limitations and more general information needs that should be evaluated for further study prior to preparation of an FWS Coordination Act Report. Major needs associated with the Hydrology submodel include a more detailed representation of hydrologic units (separately consider Harney Lake, Mud Lake, and Malheur Lake or the three hydrological units within Malheur Lake, rather than a combined lake system) and explicitly representation of groundwater storage and discharge in water budget calculations. A better representation of the hydrological units will require more detailed topographic data for the basin, capacity-elevation and elevation-surface area curves for each unit, and better water flow data between the units. Additional water quality parameters and constraints on proposed canal operation due to conditions in the Malheur River might also be added. Key Vegetation submodel needs include fine-tuning existing vegetation relationships in the model and adding relationships to address the influence of historical conditions on vegetation development, effects of very rapid changes in lake level, effects of wildlife populations (e.g., carp, muskrat), responses of vegetation to habitat management actions (e.g, haying, grazing, burning), and better representation of sago pondweed dynamics. A complementary geographic information system might also be developed for spatial analyses. Major needs that should be evaluated for the Wildlife submodel include addition of other wildlife species that have important effects on habitat on the Refuge (e.g., carp, muskrat) and consideration of additional life-cycle requisites and controlling variable for species presently in the model. Some of these limitations could perhaps be overcome if historical data on habitat conditions were developed to use with historical data on wildlife populations.

Oregon↗
USGS1958

The solusphere - its inferences and study

Water is a fundamental geologic agent active in rock decomposition, erosion, and synthesis. Solutes in water are of particular interest to geochemists as sources of raw material for synthesis or as products of decomposition. When geochemical studies move from the laboratory into natural environment many variables relating to solute hydrology must be considered. As a focal point there has been designed a graphical representation of solute hydrology, the solusphere, which embodies the concepts of land-water occurrence and movement on which are superimposed geologic, biologic, physical, chemical, and cultural processes affecting solutes. The solusphere is demonstrated by passing an imaginary plane through the centre of the earth. This plane intercepts concentric zones designated as rock flowage, saturation, aeration, surface activity, and atmosphere. Transport processes carry solutes within and between zones without alteration or conversion. However, whether stationary or in motion, the water's solute character is constantly subject to (1) alteration processes that change concentration by addition or subtraction of solutes or solvent without loss of solute identities, and (2) conversion processes that change the chemical state and form of solutes. The geochemist is concerned with specific conversion processes, but he also must consider transport, alteration, and other conversion processes that are continually modifying the materials with which he is dealing in nature. The solusphere is an attempt to organize processes affecting the chemical quality of land waters into a unified field of science much like the field of marine chemistry.

Geochimica et Cosmochimica Acta↗
USGS2007

Sediment discharge into a subsiding Louisiana deltaic estuary through a Mississippi River diversion

Wetlands of the Mississippi River deltaic plain in southeast Louisiana have been hydrologically isolated from the Mississippi River by containment levees for nearly a century. The ensuing lack of fluvial sediment inputs, combined with natural submergence processes, has contributed to high coastal land loss rates. Controlled river diversions have since been constructed to reconnect the marshes of the deltaic plain with the river. This study examines the impact of a pulsed diversion management plan on sediment discharge into the Breton Sound estuary, in which duplicate 185 m3 s-1-diversions lasting two weeks each were conducted in the spring of 2002 and 2003. Sediment delivery during each pulse was highly variable (11,300-43,800 metric tons), and was greatest during rising limbs of Mississippi River flood events. Overland flow, a necessary transport mechanism for river sediments to reach the subsiding backmarsh regions, was induced only when diversion discharge exceeded 100 m3 s-1. These results indicate that timing and magnitude of diversion events are both important factors governing marsh sediment deposition in the receiving basins of river diversions. Though the diversion serves as the primary source of river sediments to the estuary, the inputs observed here were several orders of magnitude less than historical sediment discharge through crevasses and uncontrolled diversions in the region, and are insufficient to offset present rates of relative sea level rise. ?? 2006 Elsevier Ltd. All rights reserved.

Estuarine, Coastal and Shelf Science↗
USGS2008

Isotopic variations of dissolved copper and zinc in stream waters affected by historical mining

Zinc and Cu play important roles in the biogeochemistry of natural systems, and it is likely that these interactions result in mass-dependent fractionations of their stable isotopes. In this study, we examine the relative abundances of dissolved Zn and Cu isotopes in a variety of stream waters draining six historical mining districts located in the United States and Europe. Our goals were to (1) determine whether streams from different geologic settings have unique or similar Zn and Cu isotopic signatures and (2) to determine whether Zn and Cu isotopic signatures change in response to changes in dissolved metal concentrations over well-defined diel (24-h) cycles. Average δ 66 Zn and δ 65 Cu values for streams varied from +0.02‰ to +0.46‰ and −0.7‰ to +1.4‰, respectively, demonstrating that Zn and Cu isotopes are heterogeneous among the measured streams. Zinc or Cu isotopic changes were not detected within the resolution of our measurements over diel cycles for most streams. However, diel changes in Zn isotopes were recorded in one stream where the fluctuations of dissolved Zn were the largest. We calculate an apparent separation factor of ∼0.3‰ ( 66/64 Zn) between the dissolved and solid Zn reservoirs in this stream with the solid taking up the lighter Zn isotope. The preference of the lighter isotope in the solid reservoir may reflect metabolic uptake of Zn by microorganisms. Additional field investigations must evaluate the contributions of soils, rocks, minerals, and anthropogenic components to Cu and Zn isotopic fluxes in natural waters. Moreover, rigorous experimental work is necessary to quantify fractionation factors for the biogeochemical reactions that are likely to impact Cu and Zn isotopes in hydrologic systems. This initial investigation of Cu and Zn isotopes in stream waters suggests that these isotopes may be powerful tools for probing biogeochemical processes in surface waters on a variety of temporal and spatial scales.

Geochimica et Cosmochimica Acta↗
USGS2023

At what scales does a river meander? Scale-specific sinuosity (S3) metric for quantifying stream meander size distribution

Stream bend geometry is linked to terrain features, hydrologic and ecologic conditions, and anthropogenic forces. Knowledge of the distributions of geometric properties of streams advances understanding of changing landscape conditions and associated processes that operate over a range of spatial scales. Statistical decomposition of sinuosity in natural linear features has proven a longstanding challenge and a particular impediment to automated analysis. This paper demonstrates that sinuosity can vary with the magnitude of units at which it is measured (measurement scales). The paper derives a scale-specific sinuosity (S3) metric intended to measure stream bend geometry across a range of measurement scales. The metric is warranted for analysis and modeling at measurement scales equal or similar to the spatial process and landscape conditions under investigation. Derived from the Richardson (1961) plot, the S3 metric quantifies a frequency signature of planform bend sizes spanning a range of measurement units, enabling visual and quantitative analysis of bend geometry in linear stream features. Derivation of the metric makes evident a systematic relationship between stream bend size, sinuosity, and measurement scale, formalizing a relationship between sinuosity and fractal dimension. The paper shows the utility of the S3 metric in examining bend patterns for synthetic and real-world linear stream data.

Geomorphology↗
USGS2023

The Far-Field imprint of the late Paleozoic Ice Age, its demise, and the onset of a dust-house climate across the Eastern Shelf of the Midland Basin, Texas

The late Paleozoic is a period of pronounced climatic and tectonic change, characterized by the onset and disappearance of continental-scale glaciers across polar Gondwana, the formation of Pangea, and widespread large igneous province volcanism. The low-latitude equatorial tropics are assumed to be places of persistent warm and wet climatic conditions throughout the Phanerozoic, which through intense silicate weathering, exert a major influence on Earth’s climate via the consumption of atmospheric carbon through carbonic hydrolytic weathering, formation of clay minerals and deliverability of alkalinity to ocean basins. Here we investigate the late Paleozoic sedimentary record of the Eastern Shelf of the Midland Basin in order to refine the climatic and provenance record of this region. The Eastern Shelf of the Midland Basin was situated within the equatorial tropics throughout the late Paleozoic and was connected to the open ocean through a network of fluvial systems that drained into the marine Midland Basin. We present new U-Pb zircon geochronology (19 samples, 2591 analyses) and sedimentary petrography (11 samples, 5800 grain counts), which we integrate with previously published paleobotany, paleosol chemistry and clay mineralogy to provide a holistic climate and tectonic record from this region. We observe major changes in sedimentary processes that we attribute to the formation of Pangea, eustatic changes linked to a dynamic high-latitude glaciation and teleconnections with low latitude hydrology, and a long-term shift in the Earth climate system all of which result in a dynamic sediment provenance history. Late Pennsylvanian and earliest Permian deposits are enriched in zircons with local affinity and interpreted to reflect local uplift and repeat incision across the basin margin, the latter a result of glacioeustatic forcing during an “everwet” climate. A major paleoenvironmental shift occurs in the late early Permian, which is reflected by the transition from fluvial to mixed fluvial-aeolian and ultimately aeolian dominant sedimentation by the late Permian. The transition from fluvial to aeolian dominant sedimentation is accompanied by a change in clay chemistry, sedimentary rock textual maturity, paleosol morphology and a threefold increase in Paleozoic zircons in the mid to late Permian strata. Widespread loess deposits across equatorial Pangea during the Permian have been used to argue for the possibility of equatorial glaciers situated in highland settings during the early Permian. Conversely, our data suggest initiation of a substantial component of aeolian deposition across the field areas, which is coincident with widespread ice loss across high latitude Gondwana, and ultimately highlights the teleconnections between high latitude glaciation and the low latitude hydrologic cycle.

Texas↗