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At least 1,567 records · Page 87Linked to original sources
USGS1997

Evaluation of ground-water flow and solute transport in the Lompoc area, Santa Barbara County, California

Ground-water quality in the Lompoc area, especially in the Lompoc plain, is only marginally acceptable for most uses. Demand for ground water has increased for municipal use since the late 1950's and has continued to be high for irrigation on the Lompoc plain, the principal agricultural area in the Santa Ynez River basin. As use has increased, the quality of ground water has deteriorated in some areas of the Lompoc plain. The dissolved-solids concentration in the main zone of the upper aquifer beneath most of the central and western plains has increased from less than 1,000 milligrams per liter in the 1940's to greater than 2,000 milligrams per liter in the 1960's. Dissolved- solids concentration have remained relatively constant since the 1960's. A three-dimensional finite-difference model was used to simulate ground-water flow in the Lompoc area and a two-dimensional finite-element model was used to simulate solute transport to gain a better understanding of the ground-water system and to evaluate the effects of proposed management plans for the ground-water basin. The aquifer system was simulated in the flow model as four horizontal layers. In the area of the Lompoc plain, the layers represent the shallow, middle, and main zones of the upper aquifer, and the lower aquifer. For the Lompoc upland and Lompoc terrace, the four layers represent the lower aquifer. The solute transport model was used to simulate dissolved-solids transport in the main zone of the upper aquifer beneath the Lompoc plain. The flow and solute-transport models were calibrated to transient conditions for 1941-88. A steady-state simulation was made to provide initial conditions for the transient-state simulation by using long-term average (1941-88) recharge rates. Model- simulated hydraulic heads generally were within 5 feet of measured heads in the main zone for transient conditions. Model-simulated dissolved- solids concentrations for the main zone generally differed less than 200milligrams per liter from concentrations in 1988. During 1941-88 about 1,096,000 acre-feet of water was pumped from the aquifer system. Average pumpage for this period (22,830 acre-feet per year) exceeded pumpage for the steady-state simulation by 16,590 acre-feet per year. The results of the transient simulation indicate that about 60 percent of this increase in pumpage was contributed by increased recharge, 28 percent by decreased natural discharge from the system (primarily discharge to the Santa Ynez River and transpiration), and 13 percent was withdrawn from storage. Total simulated downward leakage from the middle zone to the main zone in the central plain and upward leakage from the consolidated rocks to the main zone significantly increased in response to increased pumpage, which increased from about 6,240 to 30,870 acre-feet per year from 1941 to 1988. Average dissolved-solid concentration in the middle zone in 1987-88 ranged from 2,000 to 3,000 milligrams per liter beneath the northeastern plain and the dissolved-solids concentration of two samples from the consolidated rocks beneath the western plain averaged 4,300 milligrams per liter. Because the dissolved-solids concentration for the middle zone and the consolidated rocks is higher than the simulated steady-state dissolved-solids concentration of the main zone, the increase in the leakage from these two sources resulted in increased dissolved-solids concentration in the main zone during the transient period. The model results indicate that the main source of increased dissolved- solids concentration in the northeastern and central plains was downward leakage from the middle zone; whereas, upward leakage from the consolidated rocks was the main source of the increased dissolved-solids concentrations in the northwestern and western plains. The models were used to estimate changes in hydraulic head and in dissolved-solids concentration resulting from three proposed management alternatives: (1) average recharge

Water-Resources Investigations Report↗
USGS1985

The ground-water system in the LaGrange Aquifer near LaGrange, southeastern Wyoming

Groundwater is being developed from the La Grange aquifer in southeastern Wyoming. It consists of saturated permeable alluvium that is hydraulically connected with most of the underlying White River Group. In the area of principal interest east of Horse Creek, Hawk Springs Reservoir and 14 adjacent wells used to supplement surface-water supply in the reservoir are in a natural discharge area. Upgradient of the reservoir there are 28 irrigation wells in about a 6-square-mile area. In this area, water levels declined between 3 and 12 feet from 1973 to 1978 causing concern about the effects of well pumpage on the hydrologic system. A digital model was developed and used to simulate the two-dimensional groundwater flow system in the unconfined La Grange aquifer. Transient simulations were made for 1973-78 using 12 time periods and for 1978-80 using 25 time periods. The calibrated digital model was used to simulate four 6-month pumping alternatives including three hypothetical alternatives for the area of principal interest east of Horse Creek. The reservoir altitude was held constant, approximating a reservoir volume 7,000 acre-feet. Pumping alternative 1 simulated historic conditions for 1973-78 including monthly recharge from precipitation which was included in the next three pumping alternatives. For pumping alternative 1, the calculated rate of discharge at the end of the 6-month simulation was 5.2 cubic feet per second from the aquifer to the reservoir. At the end of the 6-month simulations for pumping alternatives 2 and 3, the calculated rate of discharge to the reservoir was decreased to 0.4 cubic feet per second by pumpage from the 14 wells and to 3.8 cubic feet per second by pumpage from the 28 irrigation wells. For pumping alternative 4, pumpage from the total 42 wells resulted in a 1.0 cubic feet per second loss from the reservoir to the aquifer. (USGS)

Water-Resources Investigations Report↗
USGS1987

Ground-water hydrology of the Toppenish Creek basin, Yakima Indian Reservation, Washington

A groundwater flow model was constructed for the Toppenish Creek basin aquifer system in eastern Washington. Flow was simulated in three aquifer units: (1) the confined old valley fill and shallow basalt (unit 2); (2) the underlying primary basalt (unit 3); and (3) the deep basalt (unit 4). Water levels in the overlying unconfined alluvial aquifer (unit 1) were held fixed. Calibrated transmissivities ranged from 0.01 to 0.48 foot squared per second. Calibrated storage coefficients were 0.0004 to 0.006. The confining-bed leakance ranged from 2.0 x 10 to the minus 11th power to 2.5 x 10 to the minus 10th power feet per second per foot. Under steady-state conditions (1954) annual natural recharge was about 29,000 acre-ft underflow from adjacent basins. Annual pumpage increased from less than 500 acre-ft in 1954 to an average of 19,600 acre-ft for 1971 and 1972. Pumpage caused simulated declines in unit 3 of up to 95 ft for 1955-72. Projected annual declines from 1973-77 using 1971-72 pumpage were about 0.5-1.5 ft in unit 2 and 0.2-1.5 ft in unit 3. The corresponding declines from 1978-82 were 0.2-1.2 ft and 0.2-0.8 ft, respectively. Using 1971-72 pumpage plus 12 ,400 acre-ft per year from unit 3, the calculated annual declines from 1978-82 were 1-36 ft in unit 2 and 4-20 ft in unit 3. (USGS)

Water-Resources Investigations Report↗
USGS1993

Geomorphic and hydraulic assessment of the Bear River in and near Evanston, Wyoming

Geomorphic and hydraulic characteristics of the Bear River in and near Evanston, Wyoming, were assessed to assist planners in stabilizing the river channel. Present-day channel instability is the result of both human-made and natural factors. The primary factor is channelization of the river in Evanston, where several meander loops were cut off artificially during early development of the city. Other contributing factors include channel-width constrictions, bank stabilization, isolated bend cutoffs upstream from the city, and flooding in 1983 and 1984. A geomorphic analysis of bankfull-channel pattern, based on four aerial photographs taken during 1946-86, quantified geomorphic properties (reach sinuosity, bend sinuosity, bend radius of curvature, and bed length) that are characteristic of the study reach. The reach sinuosity of reach 2 (the channelized reach in Evanston) was 1.18 in 1986 and remained about the same throughout the period (1946-86). The reach sinuosity of reach 2 prior to channelization was substantially larger, about 2.3 as determined from maps prepared before 1946. Hydraulic analysis of the present-day channel (surveyed 1981-87) using a one-dimensional water-surface-profile computer model identified a bankfull discharge for the study reach of 3,600 cu ft/sec. A comparison of bankfull hydraulic properties for reaches 1, 2, and 3 indicated that the effects in reach 2 of channelization and channel-width constriction--increased slope, faster velocities, and greater hydraulic radii. The present-day channel slope in reach 2 is 0.00518 ft/ft, whereas a more stable slope would be between 0.00431 ft/ft (present-day slope in reach 1) and 0.00486 ft/ft (present-day slope in reach 3).

Water-Resources Investigations Report↗
USGS2012

Computing daily mean streamflow at ungaged locations in Iowa by using the Flow Anywhere and Flow Duration Curve Transfer statistical methods

The U.S. Geological Survey (USGS) maintains approximately 148 real-time streamgages in Iowa for which daily mean streamflow information is available, but daily mean streamflow data commonly are needed at locations where no streamgages are present. Therefore, the USGS conducted a study as part of a larger project in cooperation with the Iowa Department of Natural Resources to develop methods to estimate daily mean streamflow at locations in ungaged watersheds in Iowa by using two regression-based statistical methods. The regression equations for the statistical methods were developed from historical daily mean streamflow and basin characteristics from streamgages within the study area, which includes the entire State of Iowa and adjacent areas within a 50-mile buffer of Iowa in neighboring states. Results of this study can be used with other techniques to determine the best method for application in Iowa and can be used to produce a Web-based geographic information system tool to compute streamflow estimates automatically. The Flow Anywhere statistical method is a variation of the drainage-area-ratio method, which transfers same-day streamflow information from a reference streamgage to another location by using the daily mean streamflow at the reference streamgage and the drainage-area ratio of the two locations. The Flow Anywhere method modifies the drainage-area-ratio method in order to regionalize the equations for Iowa and determine the best reference streamgage from which to transfer same-day streamflow information to an ungaged location. Data used for the Flow Anywhere method were retrieved for 123 continuous-record streamgages located in Iowa and within a 50-mile buffer of Iowa. The final regression equations were computed by using either left-censored regression techniques with a low limit threshold set at 0.1 cubic feet per second (ft3/s) and the daily mean streamflow for the 15th day of every other month, or by using an ordinary-least-squares multiple linear regression method and the daily mean streamflow for the 15th day of every other month. The Flow Duration Curve Transfer method was used to estimate unregulated daily mean streamflow from the physical and climatic characteristics of gaged basins. For the Flow Duration Curve Transfer method, daily mean streamflow quantiles at the ungaged site were estimated with the parameter-based regression model, which results in a continuous daily flow-duration curve (the relation between exceedance probability and streamflow for each day of observed streamflow) at the ungaged site. By the use of a reference streamgage, the Flow Duration Curve Transfer is converted to a time series. Data used in the Flow Duration Curve Transfer method were retrieved for 113 continuous-record streamgages in Iowa and within a 50-mile buffer of Iowa. The final statewide regression equations for Iowa were computed by using a weighted-least-squares multiple linear regression method and were computed for the 0.01-, 0.05-, 0.10-, 0.15-, 0.20-, 0.30-, 0.40-, 0.50-, 0.60-, 0.70-, 0.80-, 0.85-, 0.90-, and 0.95-exceedance probability statistics determined from the daily mean streamflow with a reporting limit set at 0.1 ft 3 /s. The final statewide regression equation for Iowa computed by using left-censored regression techniques was computed for the 0.99-exceedance probability statistic determined from the daily mean streamflow with a low limit threshold and a reporting limit set at 0.1 ft 3 /s. For the Flow Anywhere method, results of the validation study conducted by using six streamgages show that differences between the root-mean-square error and the mean absolute error ranged from 1,016 to 138 ft 3 /s, with the larger value signifying a greater occurrence of outliers between observed and estimated streamflows. Root-mean-square-error values ranged from 1,690 to 237 ft 3 /s. Values of the percent root-mean-square error ranged from 115 percent to 26.2 percent. The logarithm (base 10) streamflow percent root-mean-square error ranged from 13.0 to 5.3 percent. Root-mean-square-error observations standard-deviation-ratio values ranged from 0.80 to 0.40. Percent-bias values ranged from 25.4 to 4.0 percent. Untransformed streamflow Nash-Sutcliffe efficiency values ranged from 0.84 to 0.35. The logarithm (base 10) streamflow Nash-Sutcliffe efficiency values ranged from 0.86 to 0.56. For the streamgage with the best agreement between observed and estimated streamflow, higher streamflows appear to be underestimated. For the streamgage with the worst agreement between observed and estimated streamflow, low flows appear to be overestimated whereas higher flows seem to be underestimated. Estimated cumulative streamflows for the period October 1, 2004, to September 30, 2009, are underestimated by -25.8 and -7.4 percent for the closest and poorest comparisons, respectively. For the Flow Duration Curve Transfer method, results of the validation study conducted by using the same six streamgages show that differences between the root-mean-square error and the mean absolute error ranged from 437 to 93.9 ft 3 /s, with the larger value signifying a greater occurrence of outliers between observed and estimated streamflows. Root-mean-square-error values ranged from 906 to 169 ft 3 /s. Values of the percent root-mean-square-error ranged from 67.0 to 25.6 percent. The logarithm (base 10) streamflow percent root-mean-square error ranged from 12.5 to 4.4 percent. Root-mean-square-error observations standard-deviation-ratio values ranged from 0.79 to 0.40. Percent-bias values ranged from 22.7 to 0.94 percent. Untransformed streamflow Nash-Sutcliffe efficiency values ranged from 0.84 to 0.38. The logarithm (base 10) streamflow Nash-Sutcliffe efficiency values ranged from 0.89 to 0.48. For the streamgage with the closest agreement between observed and estimated streamflow, there is relatively good agreement between observed and estimated streamflows. For the streamgage with the poorest agreement between observed and estimated streamflow, streamflows appear to be substantially underestimated for much of the time period. Estimated cumulative streamflow for the period October 1, 2004, to September 30, 2009, are underestimated by -9.3 and -22.7 percent for the closest and poorest comparisons, respectively.

Illinois;Iowa;Minnesota;Missouri;Nebraska;Wisconsi↗
USGS1998

Ground-water flow in the surficial aquifer system and potential movement of contaminants from selected waste-disposal sites at Naval Station Mayport, Florida

Ground-water flow through the surficial aquifer system at Naval Station Mayport near Jacksonville, Florida, was simulated with a two-layer finite-difference model as part of an investigation conducted by the U.S. Geological Survey. The model was calibrated to 229 water-level measurements from 181 wells during three synoptic surveys (July 17, 1995; July 31, 1996; and October 24, 1996). A quantifiable understanding of ground-water flow through the surficial aquifer was needed to evaluate remedial-action alternatives under consideration by the Naval Station Mayport to control the possible movement of contaminants from sites on the station. Multi-well aquifer tests, single-well tests, and slug tests were conducted to estimate the hydraulic properties of the surficial aquifer system, which was divided into three geohydrologic units�an S-zone and an I-zone separated by a marsh-muck confining unit. The recharge rate was estimated to range from 4 to 15 inches per year (95 percent confidence limits), based on a chloride-ratio method. Most of the simulations following model calibration were based on a recharge rate of 8 inches per year to unirrigated pervious areas. The advective displacement of saline pore water during the last 200 years was simulated using a particle-tracking routine, MODPATH, applied to calibrated steady-state and transient models of the Mayport peninsula. The surficial aquifer system at Naval Station Mayport has been modified greatly by natural and anthropogenic forces so that the freshwater flow system is expanding and saltwater is being flushed from the system. A new MODFLOW package (VAR1) was written to simulate the temporal variation of hydraulic properties caused by construction activities at Naval Station Mayport. The transiently simulated saltwater distribution after 200 years of displacement described the chloride distribution in the I-zone (determined from measurements made during 1993 and 1996) better than the steady-state simulation. The advective movement of contaminants from selected sites within the solid waste management units to discharge points was simulated using MODPATH. Most of the particles were discharged to the nearest surface-water feature after traveling less than 1,000 feet in the ground-water system. Most areas within 1,000 feet of a surface-water feature or storm sewer had traveltimes of less than 50 years, based on an effective porosity of 40 percent. Contributing areas, traveltimes, and pathlines were identified for 224 wells at Naval Station Mayport under steady-state and transient conditions by back-tracking a particle from the midpoint of the wetted screen of each well. Traveltimes to contributing areas that ranged between 15 and 50 years, estimated by the steady-state model, differed most from the transient traveltime estimates. Estimates of traveltimes and pathlines based on steady-state model results typically were 10 to 20 years more and about twice as long as corresponding estimates from the transient model. The models differed because the steady-state model simulated 1996 conditions when Naval Station Mayport had more impervious surfaces than at any earlier time. The expansion of the impervious surfaces increased the average distance between contributing areas and observation wells.

Florida↗
USGS2002

Dynamic interpretation of slug tests in highly permeable aquifers

Considerable progress has been made in developing a theoretical framework for modeling slug test responses in formations with high hydraulic conductivity K . However, several questions of practical significance remain unresolved. Given the rapid and often oscillatory nature of test responses, the traditional hydrostatic relationship between the water level and the transducer‐measured head in the water column may not be appropriate. A general dynamic interpretation is proposed that describes the relationship between water level response and transducer‐measured head. This theory is utilized to develop a procedure for transforming model‐generated water level responses to transducer readings. The magnitude of the difference between the actual water level position and the apparent position based on the transducer measurement is a function of the acceleration and velocity of the water column, test geometry, and depth of the transducer. The dynamic approach explains the entire slug test response, including the often‐noted discrepancy between the actual initial water level displacement and that measured by a transducer in the water column. Failure to use this approach can lead to a significant underestimation of K when the transducer is a considerable distance below the static water level. Previous investigators have noted a dependence of test responses on the magnitude of the initial water level displacement and have developed various approximate methods for analyzing such data. These methods are re‐examined and their limitations clarified. Practical field guidelines are proposed on the basis of findings of this work. The soundness of the dynamic approach is demonstrated through a comparison of K profiles from a series of multilevel slug tests with those from dipole‐flow tests performed in the same wells.

Water Resources Research↗
USGS2017

Geologic assessment of undiscovered oil and gas resources—Lower Cretaceous Albian to Upper Cretaceous Cenomanian carbonate rocks of the Fredericksburg and Washita Groups, United States Gulf of Mexico Coastal Plain and State Waters

In 2010, the U.S. Geological Survey (USGS) assessed Lower Cretaceous Albian to Upper Cretaceous Cenomanian carbonate rocks of the Fredericksburg and Washita Groups and their equivalent units for technically recoverable, undiscovered hydrocarbon resources underlying onshore lands and State Waters of the Gulf Coast region of the United States. This assessment was based on a geologic model that incorporates the Upper Jurassic-Cretaceous-Tertiary Composite Total Petroleum System (TPS) of the Gulf of Mexico basin; the TPS was defined previously by the USGS assessment team in the assessment of undiscovered hydrocarbon resources in Tertiary strata of the Gulf Coast region in 2007. One conventional assessment unit (AU), which extends from south Texas to the Florida panhandle, was defined: the Fredericksburg-Buda Carbonate Platform-Reef Gas and Oil AU. The assessed stratigraphic interval includes the Edwards Limestone of the Fredericksburg Group and the Georgetown and Buda Limestones of the Washita Group. The following factors were evaluated to define the AU and estimate oil and gas resources: potential source rocks, hydrocarbon migration, reservoir porosity and permeability, traps and seals, structural features, paleoenvironments (back-reef lagoon, reef, and fore-reef environments), and the potential for water washing of hydrocarbons near outcrop areas. In Texas and Louisiana, the downdip boundary of the AU was defined as a line that extends 10 miles downdip of the Lower Cretaceous shelf margin to include potential reef-talus hydrocarbon reservoirs. In Mississippi, Alabama, and the panhandle area of Florida, where the Lower Cretaceous shelf margin extends offshore, the downdip boundary was defined by the offshore boundary of State Waters. Updip boundaries of the AU were drawn based on the updip extent of carbonate rocks within the assessed interval, the presence of basin-margin fault zones, and the presence of producing wells. Other factors evaluated were the middle Cenomanian sea-level fall and erosion that removed large portions of platform and platform-margin carbonate sediments in the Washita Group of central Louisiana. The production history of discovered reservoirs and well data within the AU were examined to estimate the number and size of undiscovered oil and gas reservoirs within the AU. Using the USGS National Oil and Gas Assessment resource assessment methodology, mean volumes of 40 million barrels of oil, 622 billion cubic feet of gas, and 14 million barrels of natural gas liquids are the estimated technically recoverable undiscovered resources for the Fredericksburg-Buda Carbonate Platform-Reef Gas and Oil AU.

Alabama, Arkansas, Florida, Louisiana, Mississippi↗
USGS1999

A dynamic water-quality modeling framework for the Neuse River estuary, North Carolina

As a result of fish kills in the Neuse River estuary in 1995, nutrient reduction strategies were developed for point and nonpoint sources in the basin. However, because of the interannual variability in the natural system and the resulting complex hydrologic-nutrient inter- actions, it is difficult to detect through a short-term observational program the effects of management activities on Neuse River estuary water quality and aquatic health. A properly constructed water-quality model can be used to evaluate some of the potential effects of manage- ment actions on estuarine water quality. Such a model can be used to predict estuarine response to present and proposed nutrient strategies under the same set of meteorological and hydrologic conditions, thus removing the vagaries of weather and streamflow from the analysis. A two-dimensional, laterally averaged hydrodynamic and water-quality modeling framework was developed for the Neuse River estuary by using previously collected data. Development of the modeling framework consisted of (1) computational grid development, (2) assembly of data for model boundary conditions and model testing, (3) selection of initial values of model parameters, and (4) limited model testing. The model domain extends from Streets Ferry to Oriental, N.C., includes seven lateral embayments that have continual exchange with the main- stem of the estuary, three point-source discharges, and three tributary streams. Thirty-five computational segments represent the mainstem of the estuary, and the entire framework contains a total of 60 computa- tional segments. Each computational cell is 0.5 meter thick; segment lengths range from 500 meters to 7,125 meters. Data that were used to develop the modeling framework were collected during March through October 1991 and represent the most comprehensive data set available prior to 1997. Most of the data were collected by the North Carolina Division of Water Quality, the University of North Carolina Institute of Marine Sciences, and the U.S. Geological Survey. Limitations in the modeling framework were clearly identified. These limitations formed the basis for a set of suggestions to refine the Neuse River estuary water-quality model.

North Carolina↗
USGS2012

Aquatic organism passage at road-stream crossings—synthesis and guidelines for effectiveness monitoring

Restoration and maintenance of passage for aquatic organisms at road-stream crossings represents a major management priority, involving an investment of hundreds of millions of dollars (for example, U.S. Government Accounting Office, 2001). In recent years, passage at hundreds of crossings has been restored, primarily by replacing barrier road culverts with bridges or stream simulation culverts designed to pass all species and all life stages of aquatic life and simulate natural hydro-geomorphic processes (U.S. Forest Service, 2008). The current situation has motivated two general questions: 1. Are current design standards for stream simulation culverts adequately re-establishing passage for aquatic biota? and 2. How do we monitor and evaluate effectiveness of passage restoration? To address the latter question, a national workshop was held in March 2010, in Portland, Oregon. The workshop included experts on aquatic organism passage from across the nation (see table of participants, APPENDIX) who addressed four classes of methods for monitoring effectiveness of aquatic organism passage—individual movement, occupancy, demography, and genetics. This report has been written, in part, for field biologists who will be undertaking and evaluating the effectiveness of aquatic organism passage restoration projects at road-stream crossings. The report outlines basic methods for evaluating road-stream crossing passage impairment and restoration and discusses under what circumstances and conditions each method will be useful; what questions each method can potentially answer; how to design and implement an evaluation study; and points out the fundamental reality that most evaluation projects will require special funding and partnerships among researchers and resource managers. The report is organized into the following sections, which can be read independently: 1. Historical context: In this section, we provide a brief history of events leading up to the present situation involving aquatic organism passage as a useful context for the issues covered herein. 2. Importance of connectivity for aquatic organisms: In this section, we provide background information regarding the movement characteristics of aquatic organisms and their vulnerability to passage impairment, and the importance of connectivity for a broad diversity of aquatic vertebrates and invertebrates. This section should be useful for practitioners in selecting what species to monitor in relation to aquatic organism passage. 3. Methods for evaluating aquatic organism passage: In this section, we present a range of perspectives on alternatives for assessing and monitoring aquatic organism passage impairment and the effectiveness of passage restoration actions, including the following methods: Individual Movement, Occupancy Models, Abundance (Demography), and Molecular Genetic Markers. 4. Relevance, strengths, and limitations of the four methods: In this section, we discuss the utility of each of the methods as a tool for assessing and quantifying passage impairment and restoration effectiveness. 5. Guidelines for selecting a method: In this section, we review some fundamental criteria and guidelines to consider when selecting a method for monitoring in the context of answering three important questions that should be addressed when developing a plan for evaluating aquatic organism passage. 6. Study and monitoring design considerations: In this section, we discuss four key design elements that need to be considered when developing a monitoring design for assessing passage impairment and restoration. The basic objectives of the report are to: 1. Review the movement characteristics of five groups of aquatic organisms that inhabit streams and to assess their general vulnerability to passage impairment at road-stream crossings; 2. Review four methods for monitoring aquatic organism passage impairment and the effectiveness of actions to restore passage at road-stream crossing structures; 3. Assess the relevance, strengths, and limitations of each method as a monitoring tool; 4. Identify and discuss guidelines that will be useful for selecting a monitoring method; and 5. Discuss what we have identified as the four key elements that need to be considered when developing a monitoring design for assessing passage impairment and restoration at road-stream crossings.

Open-File Report↗
USGS2009

Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin, With Special Emphasis on Responses of an Oligotrophic Seepage Lake to Changes in Phosphorus Loading and Water Level

Whitefish Lake, which is officially named Bardon Lake, is an oligotrophic, soft-water seepage lake in northwestern Wisconsin, and classified by the Wisconsin Department of Natural Resources as an Outstanding Resource Water. Ongoing monitoring of the lake demonstrated that its water quality began to degrade (increased phosphorus and chlorophyll a concentrations) around 2002 following a period of high water level. To provide a better understanding of what caused the degradation in water quality, and provide information to better understand the lake and protect it from future degradation, the U.S. Geological Survey did a detailed study from 2004 to 2008. The goals of the study were to describe the past and present water quality of the lake, quantify water and phosphorus budgets for the lake, simulate the potential effects of changes in phosphorus inputs on the lake's water quality, analyze changes in the water level in the lake since 1900, and relate the importance of changes in climate and changes in anthropogenic (human-induced) factors in the watershed to the water quality of the lake. Since 1998, total phosphorus concentrations increased from near the 0.005-milligrams per liter (mg/L) detection limit to about 0.010 mg/L in 2006, and then decreased slightly in 2007-08. During this time, chlorophyll a concentrations and Secchi depths remained relatively stable at about 1.5 micrograms per liter (ug/L) and 26 feet, respectively. Whitefish Lake is typically classified as oligotrophic. Because the productivity in Whitefish Lake is limited by phosphorus, phosphorus budgets were constructed for the lake. Because it was believed that much of its phosphorus comes from the atmosphere, phosphorus deposition was measured in this study. Phosphorus input from the atmosphere was greater than computed based on previously reported wetfall phosphorus concentrations. The concentrations and deposition rates can be used to estimate atmospheric loading in future lake studies. The average annual load of phosphorus to the lake was 232 pounds: 56 percent from precipitation, 27 percent from groundwater, and 16 percent from septic systems. During a series of dry years (low water levels) and wet years (high water levels), the inputs of water and phosphorus ranged by only 10-13 percent. Results from the Canfield and Bachmann eutrophication model and Carlson trophic-state-index equations demonstrated that the lake directly responds to changes in external phosphorus loading, with percent change in chlorophyll a being similar to the percent change in loading and the change in total phosphorus and Secchi depth being slightly smaller. Therefore, changes in phosphorus loading should affect the water quality of the lake. Specific scenarios that simulated the effects of anthropogenic (human-induced) and climatic (water level) changes demonstrated that: surface-water inflow (runoff) based on current development has little effect on pelagic water quality, changes in the inputs from septic systems and development in the watershed could have a large effect on water quality, and decreases in water and phosphorus loading during periods of low water level had little effect on water quality. Sustained high water levels, resulting from several wet years with relatively high water and phosphorus input, however, could cause a small degradation in water quality. Although high water levels may be associated with a degradation in water quality, it appears that anthropogenic changes in the watershed may be more important in affecting the future water quality of the lake. Fluctuations in water levels since 1998 are representative of what has occurred since 1900, with fluctuations of about 3 feet occurring about every 15 years. Based on total phosphorus concentrations inferred from sediment core analysis, there has been little long-term change in water quality and there has been a slight deterioration in water quality following most periods of high water levels. There

Scientific Investigations Report↗
USGS2005

An assessment of volcanic threat and monitoring capabilities in the United States: Framework for a National Volcano Early Warning System

Executive Summary NVEWS – a National Volcano Early Warning System – is being formulated by the Consortium of U.S. Volcano Observatories (CUSVO) to establish a proactive, fully integrated, national-scale monitoring effort that ensures the most threatening volcanoes in the United States are properly monitored in advance of the onset of unrest and at levels commensurate with the threats posed. Volcanic threat is the combination of hazards (the destructive natural phenomena produced by a volcano) and exposure (people and property at risk from the hazards). The United States has abundant volcanoes, and over the past 25 years the Nation has experienced a diverse range of the destructive phenomena that volcanoes can produce. Hazardous volcanic activity will continue to occur, and – because of increasing population, increasing development, and expanding national and international air traffic over volcanic regions – the exposure of human life and enterprise to volcano hazards is increasing. Fortunately, volcanoes exhibit precursory unrest that if detected and analyzed in time allows eruptions to be anticipated and communities at risk to be forewarned with reliable information in sufficient time to implement response plans and mitigation measures. In the 25 years since the cataclysmic eruption of Mount St. Helens, scientific and technological advances in volcanology have been used to develop and test models of volcanic behavior and to make reliable forecasts of expected activity a reality. Until now, these technologies and methods have been applied on an ad hoc basis to volcanoes showing signs of activity. However, waiting to deploy a robust, modern monitoring effort until a hazardous volcano awakens and an unrest crisis begins is socially and scientifically unsatisfactory because it forces scientists, civil authorities, citizens, and businesses into “playing catch up” with the volcano, trying to get instruments and civil-defense measures in place before the unrest escalates and the situation worsens. Inevitably, this manner of response results in our missing crucial early stages of the volcanic unrest and hampers our ability to accurately forecast events. Restless volcanoes do not always progress to eruption; nevertheless, monitoring is necessary in such cases to minimize either over-reacting, which costs money, or under-reacting, which may cost lives. Volcano monitoring in the U.S. is conducted by five volcano observatories, supported primarily by the USGS Volcano Hazards Program. Under the Stafford Act, the USGS is responsible for issuing timely warnings of potential volcanic disasters to the affected populace and civil authorities. To make maximum use of the Nation’s scientific resources, the USGS operates the observatories with the help of universities and other governmental agencies, through formal partnerships. At present, about half of the most threatening U.S. volcanoes are monitored at a basic level with real-time sensors (primarily seismic arrays), and a few are well monitored with a suite of modern instrument types and methods. However, monitoring capabilities at many hazardous volcanoes are known to be sparse or antiquated, and some hazardous volcanoes have no ground-based monitoring whatsoever.

Marianas Islands↗
USGS2003

Effects of Aquifer Development and Changes in Irrigation Practices on Ground-Water Availability in the Santa Isabel Area, Puerto Rico

The alluvial aquifer in the area of Santa Isabel is located within the South Coastal Plain aquifer of Puerto Rico. Variations in precipitation, changes in irrigation practices, and increasing public-supply water demand have been the primary factors controlling water-level fluctuations within the aquifer. Until the late 1970s, much of the land in the study area was irrigated using inefficient furrow flooding methods that required large volumes of both surface and ground water. A gradual shift in irrigation practices from furrow systems to more efficient micro-drip irrigation systems occurred between the late 1970s and the late 1980s. Irrigation return flow from the furrow-irrigation systems was a major component of recharge to the aquifer. By the early 1990s, furrow-type systems had been replaced by the micro-drip irrigation systems. Water levels declined about 20 feet in the aquifer from 1985 until present (February 2003). The main effect of the changes in agricultural practices is the reduction in recharge to the aquifer and total irrigation withdrawals. Increases in ground-water withdrawals for public supply offset the reduction in ground-water withdrawals for irrigation such that the total estimated pumping rate in 2003 was only 8 percent less than in 1987. Micro-drip irrigation resulted in the loss of irrigation return flow to the aquifer. These changes resulted in lowering the water table below sea level over most of the Santa Isabel area. By 2002, lowering of the water table reversed the natural discharge along the coast and resulted in the inland movement of seawater, which may result in increased salinity of the aquifer, as had occurred in other parts of the South Coastal Plain. Management alternatives for the South Coastal Plain aquifer in the vicinity of Santa Isabel include limiting groundwater withdrawals or implementing artificial recharge measures. Another alternative for the prevention of saltwater intrusion is to inject freshwater or treated sewage effluent into wells along the coast. A digital ground-water flow model was developed to provide information for water managers to evaluate some of these alternatives. After calibration of the ground-water model to historical data, four simulations of ground-water management strategies were performed: ground-water conservation, surface infiltration over existing agricultural fields, or infiltration along streams and canals, or injection wells along the coast. Simulations of four alternative water management strategies indicate that current condition of water levels below sea level near the coast can be reversed to raise water levels above sea level by either: (1) about a 27 percent reduction in 2003 ground-water withdrawal rates; (2) application of about 1,700 million gallons per year of artificial recharge over more than half of the current agricultural areas; (3) injection of about 3 million gallons per day (1,095 million gallons per year) of freshwater or treated wastewater in wells distributed along the coast; (4) injection of about 3.5 million gallons per day (1,280 million gallons per year) of freshwater or treated wastewater in wells distributed along canals and streams.

Water-Resources Investigations Report↗
USGS2010

Mount Rainier National Park and Olympic National Park Elk Monitoring Program Annual Report 2010

Fiscal year 2010 was the third year of gathering data needed for protocol development while simultaneously implementing what is expected to be the elk monitoring protocol at Mount Rainier (MORA) and Olympic (OLYM) national parks in the North Coast and Cascades Network (NCCN). Elk monitoring in these large wilderness parks relies on aerial surveys from a helicopter. Summer surveys are planned for both parks and are intended to provide quantitative estimates of abundance, sex and age composition, and distribution of migratory elk in high elevation trend count areas. Spring surveys are planned at Olympic National Park and are intended to provide quantitative estimates of abundance of resident and migratory elk on low-elevation winter ranges within surveyed trend count areas. An unknown number of elk is not detected during surveys. The protocol under development aims to estimate the number of missed elk by applying a model that accounts for detection bias. Detection bias in elk surveys in MORA will be estimated using a double-observer sightability model that was developed based on data from surveys conducted in 2008-2010. The model was developed using elk that were previously equipped with radio collars by cooperating tribes. That model is currently in peer review. At the onset of protocol development in OLYM there were no existing radio- collars on elk. Consequently double-observer sightability models have not yet been developed for elk surveys in OLYM; the majority of the effort in OLYM has been focused on capturing and radio collaring elk to permit the development of sightability models for application in OLYM. As a result, no estimates of abundance or composition are included in this annual report, only raw counts of the numbers of elk seen in surveys. At MORA each of the two trend count areas (North Rainier herd, and South Rainier herd) were surveyed twice. 290 and 380 elk were counted on the two replicates in the North Rainier herd, and 621 and 327 elk counted on the two replicate South Rainier counts. At Olympic National Park, each of three spring trend count areas was surveyed once in March 2010. 27 elk were observed in the South Fork Hoh trend count area, 137 elk were observed in the Hoh trend count area, and 131 elk were observed in the Queets trend count area. In September 2010, 18 elk were captured and fitted with radio collars as part of a contracted animal capture, eradication and tagging of animals (ACETA) operation. These animals will be available to contribute double-observer sightability data in future spring and summer surveys. There were no summer surveys for elk in OLYM in 2010.

Washington↗
USGS2005

Hydrogeology and ground-water/surface water interactions in the Des Moines River valley, southwestern Minnesota, 1997-2001

Increased water demand in and around Windom led the U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources, local water suppliers, and Cottonwood County, to study the hydrology of aquifers in the Des Moines River Valley near Windom. The study area is the watershed of a 30-kilometer (19-mile) reach of the Des Moines River upstream from Windom. Based on stratigraphic analysis, two hydrologically and genetically separate surficial aquifers underlie the study area. The Windom aquifer has a saturated thickness of 34 meters (111 feet), and the Des Moines aquifer has a saturated thickness of 33 meters (108 ft). The surficial aquifers are relatively isolated from deeper aquifers by till, but some leakage probably occurs. Recharge to the aquifers is from areal recharge, from Cottonwood Lake, and from edge recharge. Pumping at the Windom well field induces substantial amounts of Cottonwood Lake water into the aquifer. During this study, the water level in a well located between two Red Rock wells and the river was lower than the river level during two periods. During those periods, water in the Des Moines River had the potential to recharge the aquifer. Discharge from the aquifers is primarily to municipal wells, the Des Moines River, and other surface waters. Most of the ground-water samples collected in the study area consisted of calcium-magnesium bicarbonate waters. Corn and soybean herbicides and their degradates were detected at low concentrations in 14 of 27 ground-water samples and in all 3 river samples. Metolachlor ethane sulfonic acid was the most commonly detected compound and also was detected at the highest concentrations. Nutrient concentrations in ground-water samples were skewed low with high outliers, and nutrient concentrations in river samples generally were less than analytical reporting limits. Nearly all recharge to the aquifer in the ground-water simulation was from edge recharge (80 percent). Calibrated net areal recharge ranged from 17 to 30 percent of the average annual precipitation. Isotopic composition of ground water and Cottonwood Lake water indicated about one-half of the water withdrawn from the Windom aquifer is from Cottonwood Lake. Scenarios tested with the calibrated model involved increased ground-water withdrawals and changes in recharge to simulate drier or wetter weather conditions. Doubling the withdrawals from all wells in the model had a small effect except in the Windom well-field area. Maximum head declines in the Red Rock well field and the Jeffers city well were less than 40 centimeters (15 inches). In the Windom well field, the maximum head decline was 11 meters (36 feet). The Windom well field does not induce recharge from the Des Moines River. The addition of a new well that pumped 2,000 cubic meters per day (0.44 million gallons per day) in the Augusta Lake Valley area caused a 0.83-meter-deep (2.72-foot-deep) cone of depression that extended to the valley walls. The drought scenario and the high-precipitation scenario resulted in head changes in the northern part of the Augusta Lake Valley area, in the southwestern part of the Red Rock area, and near the valley edges. Long-term withdrawals of water for public supplies may cause a net decrease in ground-water discharge to surface water. Water that does not evaporate, or that is not exported, is discharged to the Des Moines River but with changed water quality. Because ground-water and surface-water qualities in the study area are similar, the ground-water discharge probably has little effect on river water quality.

Minnesota↗
USGS2009

Topographic Change Detection at Select Archeological Sites in Grand Canyon National Park, Arizona, 2006-2007

Topographic change of archeological sites within the Colorado River corridor of Grand Canyon National Park (GCNP) is a subject of interest to National Park Service managers and other stakeholders in the Glen Canyon Dam Adaptive Management Program. Although long-term topographic change resulting from a variety of natural processes is typical in the Grand Canyon region, a continuing debate exists on whether and how controlled releases from Glen Canyon Dam, located immediately upstream of GCNP, are impacting rates of site erosion, artifact transport, and the preservation of archeological resources. Continued erosion of archeological sites threatens both the archeological resources and our future ability to study evidence of past cultural habitation. Understanding the causes and effects of archaeological site erosion requires a knowledge of several factors including the location and magnitude of the changes occurring in relation to archeological resources, the rate of the changes, and the relative contribution of several potential causes, including sediment depletion associated with managed flows from Glen Canyon Dam, site-specific weather patterns, visitor impacts, and long-term climate change. To obtain this information, highly accurate, spatially specific data are needed from sites undergoing change. Using terrestrial lidar data collection techniques and novel TIN- and GRID-based change-detection post-processing methods, we analyzed topographic data for nine archeological sites. The data were collected using three separate data collection efforts spanning 16 months (May 2006 to September 2007). Our results documented positive evidence of erosion, deposition, or both at six of the nine sites investigated during this time interval. In addition, we observed possible signs of change at two of the other sites. Erosion was concentrated in established gully drainages and averaged 12 cm to 17 cm in depth with maximum depths of 50 cm. Deposition was concentrated at specific locations outside of drainages but generally was spread over larger areas (tens to hundreds of square meters). Maximum depths of deposition averaged 12 cm to 15 cm and reached as much as 35 cm. Overall, we found that the spatial distribution and magnitudes of surface change are specific to each site and that a thorough understanding of the geomorphology, weather, and sand supply is requisite for a complete understanding of the data. Additional work in combining these results with site-specific weather, hydrology, and geomorphology data will assist in the development of working models for determining the causes of the documented topographic changes.

Scientific Investigations Report↗
USGS2023

Moving Aircraft River Velocimetry (MARV): Framework and proof-of-concept on the Tanana River

Information on velocity fields in rivers is critical for designing infrastructure, modeling contaminant transport, and assessing habitat. Although non-contact approaches to measuring flow velocity are well established, these methods assume a stationary imaging platform. This study eliminates this constraint by introducing a framework for moving aircraft river velocimetry (MARV). The workflow takes as input images acquired from an airplane and involves orthorectification, frame overlap analysis, image enhancement, particle image velocimetry (PIV), and aggregation of the resulting velocity vectors onto a prediction grid. We also use new metrics to quantify the agreement between image-derived and field-measured velocity vectors in terms of both orientation and magnitude. The potential of MARV was evaluated using data from two Alaskan rivers: a large, highly turbid channel and its smaller, clearer tributary. Sediment boil vortices on the mainstem provided natural features trackable via PIV and estimated velocities corresponded closely with field measurements ( R 2 up to 0.911). We compared an exhaustive approach that evaluates overlap for all frame combinations to a simpler rolling window implementation and found that the more efficient algorithm did not compromise accuracy. Sensitivity analysis suggested that the method was robust to window parameterization. Comparing PIV output from different flying heights and imaging systems indicated that larger pixels led to higher accuracy and that a more advanced dual-camera system provided superior performance. Results from the tributary were less encouraging, presumably due to a lack of trackable features in visible images. Testing across a range of rivers is needed to assess the generality of MARV.

Water Resources Research↗
USGS2002

Delineation of the Troy Bedrock Valley and particle-tracking analysis of ground-water flow underlying Belvidere, Illinois

The U.S. Geological Survey, U.S. Environmental Protection Agency, and Illinois Environmental Protection Agency began a study of the hydrogeology, flow system, and distribution of contaminants in the aquifers underlying Belvidere, Ill., and vicinity in 1992. As part of the study, the ancestral Troy Bedrock Valley, located about 1.5 miles west of Belvidere, was identified as an important part of the ground-water-flow system. In the deepest parts of the valley, the basal Glenwood confining unit may be absent; thick deposits of sand and gravel that infill part of the valley may directly overlie the sandstone St. Peter aquifer, a regionally important source of water for public supply. With few deep wells open to the St. Peter aquifer present in the valley to provide necessary geologic information, tritium and other water-chemistry data were collected from eight wells to possibly delineate areas where the confining unit may be absent; the data also provide baseline water-quality information for an area expecting changes in land use and increases in water withdrawal. Also as part of the study, particle-tracking analysis was done using an available flow model to (1) identify possible discharge locations of ground water and contaminants and (2) delineate areas contributing recharge to the Belvidere municipal wells. This report presents and interprets water-chemistry data collected during December 2000 and presents results of particle-tracking analysis. Ground water in samples from two of four wells open to the St. Peter aquifer appears to have recharged after 1954, suggesting that the Glenwood confining unit may be absent near the wells. Other hydrogeologic and water-chemistry data, however, were inconclusive or contradictory. Concentrations of iron, manganese, and lead exceeded maximum contaminant levels in five or less samples, but materials associated with the water-distribution systems appear to contribute to the elevated concentrations above natural levels. Particle-tracking analysis indicates that most ground-water flow beneath possible contaminant-source areas discharges from the glacial drift aquifer to the Kishwaukee River. Most of the source areas are in or near Belvidere and are within 1,500 feet of the river. The analysis also indicates the possibility that in parts of the study area, some ground water does not discharge to the river, but flows beneath the Kishwaukee River in the underlying carbonate Galena-Platteville aquifer. Ground water that discharges to the one municipal well open to the glacial drift aquifer is estimated to travel over 1 mile in less than 25 years. Simulated residence (travel) times of ground water from the base of the glacial drift aquifer to the six municipal wells open, in part, to the Galena-Platteville aquifer, are estimated at less than about 40 years. Because fractures in this aquifer are unaccounted for in the flow model, actual areas contributing recharge are likely larger and travel times faster than those simulated for most of the municipal wells. Tritium data indicate that, in general, travel times from the land surface to the deepest parts of the Galena-Platteville aquifer are less than 46 years. Methyl tertiary-butyl ether data indicate that travel times to the upper part of the aquifer may be less than 16 years. The water-quality-based estimates of travel time generally are consistent with the estimates from particle-tracking analysis.

Illinois↗