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Hydrogeologic and water-quality data for the main site, Naval Surface Warfare Center, Dahlgren Laboratory, Dahlgren, Virginia

Hydrogeologic and water-quality data were collected at the Naval Surface Warfare Center, Dahlgren Laboratory at Dahlgren, Virginia, as part of a hydrogeologic assessment of the shallow aquifer system begun in 1992. The U.S. Geological Survey conducted this study to provide the Navy with hydrogeologic data to meet the requirements of a Spill Contingency Plan. This report describes the ground-water observation-well network, hydro- geologic, and water-quality data collected between August 1992 and September 1993. The report includes a description of the locations and con- struction of 35 observation wells on the Main Site. Hydrologic data include lithologic core samples, geophysical logs, and vertical hydraulic conductivity measurements of selected core intervals. Hydrologic data include synoptic and hourly measurements of ground-water levels, observation-well slug tests to determine horizontal hydraulic conductivity, and tide data. Water-quality data include analyses of major dissolved constituents in ground water and surface water.

Open-File Report

Background hydrologic information in potential lignite mining areas in north-central Mississippi, August 1984

The U.S. Geological Survey, in cooperation with the Mississippi Department of Natural Resources, Bureau of Geology, is conducting a hydrologic data collection program in potential lignite-producing areas in Mississippi. During the last two weeks of August 1984, hydrologic data were collected at 15 stream sites that drain potential lignite mining areas in Lafayette, Calhoun, and Yalobusha Counties. Main channel widths ranged from approximately 60 feet at three streams (Coon Creek near Toccopula, Muckaloon Creek near Tula, and Hurricane Creek near Velma) to approximately 120 feet at two streams (Potlockney Creek near Tula, and Savannah Creek near Bruce). Maximum water depths ranged from less than 1.0 foot at most streams to over 5.0 feet at sites on Potlockney Creek near Tula and McGill Creek near Sarepta. Stream discharge ranged from 0.32 cubic feet per second in Persimmon Creek near Bruce to 18.5 cubic feet per second in Puskus Creek near Etta. The specific conductance of stream water ranged from 25 to 160 microsiemens and dissolved solids concentrations ranged from 22 to 91 mg/L (milligrams per liter). Most major ion concentrations were less than 10 mg/L with the exception of calcium (11 mg/L), sodium (12 mg/L) and sulfate (18 mg/L) in the water of Persimmon Creek near Bruce. Dissolved oxygen concentrations were greater than 5.0 mg/L at all but one site. Turbidity values were generally less than 50 units. Nitrate plus nitrite concentrations were equal to or less than 0.10 mg/L in all streams except in Potlockney Creek near Tula where the concentration was 0.11 mg/L. Copper and selenium concentrations in the water at all sampling sites ranged from below the detection limits (1 microgram/g) to 4 micrograms/g (micrograms per gram) and mercury concentrations in bottom material samples ranged from less than 0.01 microgram/g to 0.15 microgram/g. (USGS)

Open-File Report

Numerical simulation of groundwater movement and managed aquifer recharge from Sand Hollow Reservoir, Hurricane Bench area, Washington County, Utah

The Hurricane Bench area of Washington County, Utah, is a 70 square-mile area extending south from the Virgin River and encompassing Sand Hollow basin. Sand Hollow Reservoir, located on Hurricane Bench, was completed in March 2002 and is operated primarily as a managed aquifer recharge project by the Washington County Water Conservancy District. The reservoir is situated on a thick sequence of the Navajo Sandstone and Kayenta Formation. Total recharge to the underlying Navajo aquifer from the reservoir was about 86,000 acre-feet from 2002 to 2009. Natural recharge as infiltration of precipitation was approximately 2,100 acre-feet per year for the same period. Discharge occurs as seepage to the Virgin River, municipal and irrigation well withdrawals, and seepage to drains at the base of reservoir dams. Within the Hurricane Bench area, unconfined groundwater-flow conditions generally exist throughout the Navajo Sandstone. Navajo Sandstone hydraulic-conductivity values from regional aquifer testing range from 0.8 to 32 feet per day. The large variability in hydraulic conductivity is attributed to bedrock fractures that trend north-northeast across the study area. A numerical groundwater-flow model was developed to simulate groundwater movement in the Hurricane Bench area and to simulate the movement of managed aquifer recharge from Sand Hollow Reservoir through the groundwater system. The model was calibrated to combined steady- and transient-state conditions. The steady-state portion of the simulation was developed and calibrated by using hydrologic data that represented average conditions for 1975. The transient-state portion of the simulation was developed and calibrated by using hydrologic data collected from 1976 to 2009. Areally, the model grid was 98 rows by 76 columns with a variable cell size ranging from about 1.5 to 25 acres. Smaller cells were used to represent the reservoir to accurately simulate the reservoir bathymetry and nearby monitoring wells; larger cells were used in the northern and southern portions of the model where water-level data were limited. Vertically, the aquifer system was divided into 10 layers, which incorporated the Navajo Sandstone and Kayenta Formation. The model simulated recharge to the groundwater system as natural infiltration of precipitation and as infiltration of managed aquifer recharge from Sand Hollow Reservoir. Groundwater discharge was simulated as well withdrawals, shallow drains at the base of reservoir dams, and seepage to the Virgin River. During calibration, variables were adjusted within probable ranges to minimize differences among model-simulated and observed water levels, groundwater travel times, drain discharges, and monthly estimated reservoir recharge.

Utah

Evaluation of the Radar Stage Sensor manufactured by Forest Technology Systems—Results of laboratory and field testing

Two identical Radar Stage Sensors from Forest Technology Systems were evaluated to determine if they are suitable for U.S. Geological Survey (USGS) hydrologic data collection. The sensors were evaluated in laboratory conditions to evaluate the distance accuracy of the sensor over the manufacturer’s specified operating temperatures and distance to water ranges. Laboratory results were compared to the manufacturer’s accuracy specification of ±0.007 foot (ft) and the USGS Office of Surface Water (OSW) policy requirement that water-level sensors have a measurement uncertainty of no more than 0.01 ft or 0.20 percent of the indicated reading. Both of the sensors tested were within the OSW policy requirement in both laboratory tests and within the manufacturer’s specification in the distance to water test over tested distances from 3 to 15 ft. In the temperature chamber test, both sensors were within the manufacturer’s specification for more than 90 percent of the data points collected over a temperature range of –40 to +60 degrees Celsius at a fixed distance of 8 ft. One sensor was subjected to an SDI-12 communication test, which it passed. A field test was conducted on one sensor at a USGS field site near Landon, Mississippi, from February 5 to March 29, 2016. Water-level measurements made by the radar during the field test were in agreement with those made by the Sutron Accubar Constant Flow Bubble Gauge. Upon the manufacturer’s release of updated firmware version 1.09, additional SDI-12 and temperature testing was performed to evaluate added SDI-12 functions and verify that performance was unaffected by the update. At this time, an Axiom data logger is required to perform a firmware update on this sensor. The data confirmed the results of the original test. Based on the test results, the Radar Stage Sensor is a suitable choice for USGS hydrologic data collection.

Open-File Report

Streams, springs, and volcanic lakes for volcano monitoring

Introduction Volcanic unrest can trigger appreciable change to surface waters such as streams, springs, and volcanic lakes. Magma degassing produces gases and soluble salts that are absorbed into groundwater that feeds streams and lakes. As magma ascends, the amount of heat and degassing will increase, and so will any related geochemical and thermal signal. Subsurface magma movement can cause pressurization that alters hydrostatic head and may induce groundwater discharge. Fluid-pressure changes have been linked to distal volcano-tectonic earthquakes (White and McCausland, 2016; Coulon and others, 2017) and phreatic eruptions (for example, Yamaoka and others, 2016). Clearly, changes in groundwater and surface waters are both indicators of unrest and clues to how and where magma is rising toward the surface. Where possible, it is prudent to incorporate real-time hydrologic data into multiparameter monitoring of restless volcanoes. Hydrologic dynamics can also be tracked by changes in groundwater levels that are commonly measured in shallow boreholes (see of Flinders, A.F., Lowenstern, J.B., Coombs, M.L., and Poland, M.P., eds., Recommended capabilities and instrumentation for volcano monitoring in the United States: U.S. Geological Survey Scientific Investigations Report 2024–5062–K, 5 p., https://doi.org/10.3133/sir20245062k. ">chapter K , this volume, on boreholes; Hurwitz and Lowenstern, 2024). Although inferred to be common, relatively few volcano-hydrology anomalies are well documented, and many are essentially anecdotal (Newhall and others, 2001), reflecting the fact that high-resolution time series remain rare. Extreme examples include the 2008 eruption of Nevado del Huila, Colombia, where relatively minor phreatomagmatic eruptions were accompanied by expulsion of as much as 300 million cubic meters of groundwater from fissures high on the volcano (Worni and others, 2011), generating large lahars. Substantial decreases in flow rate from springs about 8 kilometers from the summit of Mayon Volcano, Philippines, have been noted before most eruptions in the 20th century (Newhall and others, 2001). Stream monitoring at Redoubt Volcano in 2009 allowed Werner and others (2012) to recognize that groundwater was unable to absorb (or scrub) the high flux of volcanic gas and that a high CO 2 /SO 2 precursor signal had been evident for 5 months prior to the eruption. A key to better interpreting hydrologic anomalies—or even identifying them—is therefore obtaining adequate baseline data. Most hydrologic monitoring at U.S. volcanoes has been accomplished by intermittent sampling surveys with annual or less frequent sampling (for example, https://hotspringchem.wr.usgs.gov/index.php ). More frequent sampling, however, generally is needed to establish reliable baselines. A recent hydrologic and hydrothermal monitoring experiment at 25 sites and 10 of the 12 level 4 (very high threat) volcanoes in the U.S. portion of the Cascade Range demonstrated that there is sufficient temporal variability in hydrothermal fluxes, even during quiescent periods, that one-time measurements will commonly have limited interpretive value (Crankshaw and others, 2018). Thus, surveys are best augmented with data from streamgages (for example, Evans and others, 2004; Bergfeld and others, 2008). Streamflow (water discharge) data allow measured temperature and specific conductance to be converted to heat and solute mass fluxes, which could be insightful parameters for detecting anomalous activity (McCleskey and others, 2012). At the Yellowstone Caldera, long-term monitoring of river solutes has allowed calculation of the chloride flux, a proxy for heat discharge (Hurwitz and others, 2007; McCleskey and others, 2016) from the subsurface magma. This is readily accomplished because data from streamgages are continuously recorded and archived by the U.S. Geological Survey (USGS) National Water Information System (NWIS) (USGS, 2024). Similar studies on stratovolcanoes or shield volcanoes would be scientifically useful, and yet are logistically challenging, requiring streamgages on numerous radial drainages complemented by either frequent manual sampling or numerous deployments of equipment to measure water temperature and specific conductance as a proxy for water chemistry. Another challenge is that some volcanic areas, especially shield volcanoes, are characterized by near-surface porous rocks and soils, such that surface streams are rare and replaced by distant, dilute large-volume springs with only a trace of any original volcanically sourced water (Manga, 2001; Hurwitz and others, 2021). Volcanic lakes are worthy of special attention for monitoring efforts, as their temperature and composition can provide evidence of increased flux of volatile-rich fluids from below. Quantifying changes in volatile and heat release from magma can be simpler in lakes than for volcanoes with radial drainages and no major lakes. Moreover, volcanic lakes pose a range of hazards themselves, including phreatomagmatic eruptions, debris flows, flank collapse, tsunamis, and toxic gas release (Mastin and Witter, 2000; Delmelle and others, 2015; Manville, 2015; Rouwet and others, 2015)—hazards that have historically been responsible for substantial loss of life at many volcanoes worldwide (Manville, 2015). Catastrophic CO 2 release at Lake Nyos, Cameroon, in 1986 suffocated about 1,750 people and about 3,500 livestock and was probably triggered by a large landslide into the gas-saturated lake (Kling and others, 1987; Evans and others, 1993). Gas-charged springs in Soda Bay within Clear Lake (California) have caused almost a dozen deaths to bathers in the past hundred years (ABC News, 2000). A 2005 example of lake overturn and abundant gas release was documented at Mount Chiginagak in Alaska (Schaefer and others, 2008) but did not result in any human casualties. Although thermally stratified lakes, which promote trapping of exsolved magmatic gas, tend to develop in tropical regions, the phenomenon can also arise where salinity creates meromixis (a condition in which a lake does not mix completely), as occurs in Mono Lake, California (Jellison and Melack, 1993; Jellison and others, 1998). If magma erupts or flows into a lake, the interaction between hot magma and cold water can be explosive (Mastin and others, 2004; Zimanowski and others, 2015) and substantially expand the area affected by the eruption. Another hazard is the breaching of crater rims by landslides triggered by volcanic and (or) seismic activity. Under some circumstances, substantial volumes of water can be displaced, leading to large floods and lahars. Late Holocene lake flooding from Aniakchak Crater in the Alaska Peninsula (Waythomas, 2022) and from Paulina Lake in Newberry Crater, Oregon (Chitwood and Jensen, 2000), caused by the failure of outlet sills, testify to the substantial hazards at lake-filled calderas. Several volcanic systems in the United States host lakes known to receive heat and gas from underlying magma. These lakes vary widely in area, depth, and chemical composition. Lakes are present at level 4 volcanoes, including Crater Lake and Newberry Volcano in Oregon; Yellowstone Caldera in Wyoming; Long Valley Caldera, Clear Lake volcanic field, Medicine Lake, and Salton Buttes in California; and Aniakchak Crater, Mount Katmai, Fisher Caldera, Mount Okmok, and Kaguyak Crater, among others, in Alaska. A water lake was present in Halemaʻumaʻu, the crater of Kīlauea, Hawai‘i (fig. F1), from October 2019 to December 2020. Level 3 volcanoes with lakes include Mono Lake volcanic field (Calif.), Mount Bachelor (Ore.), Ukinrek Maars and Mount Chiginagak (Alaska), and Soda Lake (Nevada). In addition, there are lakes at many levels 1 and 2 volcanoes. In the United States, there are no strongly acidic lakes that receive abundant input of magmatic gas, such as those found at Mount Ruapehu (New Zealand), Ijen and Kelud (Indonesia), and Poás (Costa Rica). Nevertheless, many contain fluids that provide clues to magmatic processes below. Since publication of a previous report on recommended instrumentation for volcano monitoring (Moran and others, 2008), continuous hydrologic monitoring has become increasingly feasible. However, changes in water pressure, temperature, and chemistry remain, in general, poorly studied phenomena at volcanoes (Sparks, 2003; National Academies of Sciences, Engineering, and Medicine, 2017). Recent efforts by the USGS have included the temporary study of Cascade Range volcanoes, which included frequent (15 minute to hourly) temporal sampling of temperature, depth, and conductivity (Crankshaw and others, 2018; Ingebritsen and Evans, 2019). At Yellowstone Caldera, many streamgages have now added thermistors and specific conductance sensors, allowing estimation of time-dependent chloride flux as a proxy for variations in subsurface heat flux (McCleskey and others, 2012, 2016). Efforts to better understand lakes have also accelerated, with bathymetric mapping and sampling carried out at several locations in the United States. Especially thorough work was done at Yellowstone Lake thanks to the Hydrothermal Dynamics of Yellowstone Lake (HD-YLAKE, https://hdylake.org ) project, funded primarily by the National Science Foundation. In addition to geophysical surveys and recovery of cores and other samples, HD-YLAKE investigations included remotely operated vehicle (ROV) investigations of hydrothermal vents on the lake floor (fig. F2). Data collected by the ROV provided a better understanding of the thermal and chemical influx from lake-bottom hydrothermal systems (Sohn and others, 2017). In this chapter, we focus on detecting changes in the chemistry, temperature, discharge, or water levels of streams, springs, and lakes that can be caused by seismicity, volumetric strains, or increases in gas flux associated with ascending magma. There is unavoidable overlap with other chapters of this report. Samples of water and gas can also be obtained in boreholes ( of Flinders, A.F., Lowenstern, J.B., Coombs, M.L., and Poland, M.P., eds., Recommended capabilities and instrumentation for volcano monitoring in the United States: U.S. Geological Survey Scientific Investigations Report 2024–5062–K, 5 p., https://doi.org/10.3133/sir20245062k. ">chapter K , this volume; Hurwitz and Lowenstern, 2024), both shallow and deep. Gas monitoring ( of Flinders, A.F., Lowenstern, J.B., Coombs, M.L., and Poland, M.P., eds., Recommended capabilities and instrumentation for volcano monitoring in the United States: U.S. Geological Survey Scientific Investigations Report 2024–5062–E, 11 p., https://doi.org/10.3133/sir20245062e.">chapter E , this volume; Lewicki and others, 2024) relies in part on samples from springs and wells, particularly where measurable gas plumes are absent. Water acts as a trigger and lubricant for landslides and sediment-rich floods, and so hydrology has obvious relevance for lahar monitoring, as discussed in of Flinders, A.F., Lowenstern, J.B., Coombs, M.L., and Poland, M.P., eds., Recommended capabilities and instrumentation for volcano monitoring in the United States: U.S. Geological Survey Scientific Investigations Report 2024–5062–H, 6 p., https://doi.org/10.3133/sir20245062h. ">chapter H (this volume; Thelen and others, 2024). Shared situational awareness among scientists engaged in geophysical, gas, and hydrologic monitoring will improve overall understanding of the volcanic hazard.

Scientific Investigations Report

Investigation of the groundwater system at Masaya Caldera, Nicaragua, using transient electromagnetics and numerical simulation

The distribution of groundwater beneath Masaya Volcano, in Nicaragua, and its surrounding caldera was characterized using the transient electromagnetic method (TEM). Multiple soundings were conducted at 30 sites. Models of the TEM data consistently indicate a resistive layer that is underlain by one or more conductive layers. These two layers represent the unsaturated and saturated zones, respectively, with the boundary between them indicating the water-table elevation. A map of the TEM data shows that the water table in the caldera is a subdued replica of the topography, with higher elevations beneath the edifice in the south-central caldera and lower elevations in the eastern caldera, coinciding with the elevation of Laguna de Masaya. These TEM data, combined with regional hydrologic data, indicate that the caldera in hydrologically isolated from the surrounding region, with as much as 60??m of difference in elevation of the groundwater table across caldera-bounding faults. The water-table information and estimates of fluxes of water through the system were used to constrain a numerical simulation of groundwater flow. The simulation results indicate that basalt flows in the outer parts of the caldera have a relatively high transmissivity, whereas the central edifice has a substantially lower transmissivity. A layer of relatively high transmissivity must be present at depth within the edifice in order to deliver the observed flux of water and steam to the active vent. This hydrologic information about the caldera provides a baseline for assessing the response of this isolated groundwater system to future changes in magmatic activity. ?? 2007.

Journal of Volcanology and Geothermal Research

Percentage change in saturated thickness of the High Plains Aquifer, west-central Kansas, 1950 to average 1980-82

A statistical technique, called kriging, was programmed for a computer to interpolate hydrologic data based on a network of 296 measured values in west-central Kansas and eastern Colorado. The computer program generated estimated values of selected hydrologic data at the center of each 1-mile section in the Western Kansas Groundwater Management District No. 1. This program facilitated contouring of the data that are needed to aid in the management of ground water for irrigation. The kriging technique produced a map that illustrates the percentage change in saturated thickness of the High Plains aquifer from 1950 to average 1980-82 in west-central Kansas. Estimated changes in saturated thickness of the aquifer, as shown on the map, range from about a 50% increase to a 100% decrease. (USGS)

Open-File Report

Recent developments in hydrologic instrumentation

The programs of the U.S. Geological Survey require instrumentation for collecting and monitoring hydrologic data in cold regions. The availability of space-age materials and implementation of modern electronics and mechanics is making possible the recent developments of hydrologic instrumentation, especially in the area of measuring streamflow under ice cover. Material developments include: synthetic-fiber sounding and tag lines; polymer (plastic) sheaves, pulleys, and sampler components; and polymer (plastic) current-meter bucket wheels. Electronic and mechanical developments include: a current-meter digitizer; a fiber-optic closure system for current-meters; non-contact water-level sensors; an adaptable hydrologic data acquisition system; a minimum data recorder; an ice rod; an ice foot; a handled sediment sampler; a light weight ice auger with improved cutter head and blades; and an ice chisel.

American Water Resources Association Technical Pub

Cost effectiveness of the US Geological Survey's stream-gaging programs in New Hampshire and Vermont

Data uses and funding sources were identified for the 73 continuous stream gages currently (1984) being operated. Eight stream gages were identified as having insufficient reason to continue their operation. Parts of New Hampshire and Vermont were identified as needing additional hydrologic data. New gages should be established in these regions as funds become available. Alternative methods for providing hydrologic data at the stream gaging stations currently being operated were found to lack the accuracy that is required for their intended use. The current policy for operation of the stream gages requires a net budget of $297,000/yr. The average standard error of estimation of the streamflow records is 17.9%. This overall level of accuracy could be maintained with a budget of $285,000 if resources were redistributed among gages. Cost-effective analysis indicates that with the present budget, the average standard error could be reduced to 16.6%. A minimum budget of $278,000 is required to operate the present stream gaging program. Below this level, the gages and recorders would not receive the proper service and maintenance. At the minimum budget, the average standard error would be 20.4%. The loss of correlative data is a significant component of the error in streamflow records, especially at lower budgetary levels. (Author 's abstract)

Water-Resources Investigations Report

Summary appraisals of the nation's ground-water resources – Missouri basin region

The Missouri Basin Region lies in the north-central part of the United States and southern Canada. It includes parts of Alberta and Saskatchewan in Canada; parts of Montana, Wyoming, North Dakota, South Dakota, Minnesota, Iowa, Colorado, Kansas, and Missouri, and all of Nebraska in the United States. The region includes about one-sixth of the contiguous United States and requires large water supplies for irrigation, industrial, public, and rural uses. Climate ranges from semiarid to subhumid. Normal annual precipitation increases generally eastward in the downstream direction, but precipitation is not a dependable source of supply. The Missouri River and its tributaries furnish water to many users, but surface water is often inadequate to meet large demands. Numerous surface reservoirs help to regulate streamflow and provide storage, but they also allow an increase in evapotranspiration, which in some areas exceeds normal precipitation. Ground water occurs in aquifers classified as alluvial deposits of sand and gravel, glacial deposits, dune-sand deposits, basin-fill deposits of sand and gravel, sandstone, siltstone, fractured sandy clay, limestone, and dolomite. Ground water can be developed and managed in an orderly manner provided adequate geologic and hydrologic data are available to determine aquifer characteristics and response to pumping and other hydraulic stresses. These data and determinations are essential to design, testing, and implementation of water management plans. Unconsolidated and semiconsolidated aquifers include valley-fill alluvium, areally extensive alluvium, glacial deposits, and basin-fill deposits. The aquifers normally consist of alluvial sand and gravel that contain unconfined ground water that lies near the land surface. Many wells completed in the alluvial aquifers have high yields of good-quality water because most alluvial aquifers are highly transmissive and hydraulically connected to streams. Aquifers in glacial deposits may be difficult to locate and in some areas contain saline water; nevertheless, these aquifers are sources of water supply for many users. Basin-fill aquifers are as much as several thousand feet thick, and many contain large ground-water supplies. Ground-water mining has occurred in semiconsolidated aquifers because of withdrawals from wells. Unconsolidated and semiconsolidated aquifers have potential for conjunctive use with surface water, recycling to reuse available supplies, artificial recharge, and salvage of evapotranspired water. Sandstone aquifers lie near the land surface and in structural basins. Interbasin movement of ground water occurs in the Virgelle (Milk River aquifer), Fox Hills-basal Hell Creek, and Dakota aquifers. Sandstone aquifers are less transmissive than unconsolidated and semiconsolidated aquifers in general. Confined sandstone aquifers are common, and flowing wells are obtained in many areas. However, flowing wells may cause large declines in water levels if uncontrolled. Water quality is variable in sandstone aquifers but is adequate for most needs. Sandstone aquifers have potential for artificial recharge, induced interaquifer leakage, conjunctive use with surface water, and mining of ground water. Limestone and dolomite aquifers are extensive in the region, but in some areas they lie deep below the land surface. The occurrence of ground water in small pores, fractures, or large caverns causes yields from wells to range widely. Large flows through cavern systems in the aquifers are indicated by large springs in some areas. Water quality is extremely variable and must be considered in any water-development plan. Limestone and dolomite aquifers have potential for development of large water supplies in some areas. The development may be aided by induced recharge and interaquifer leakage. Saline ground water occurs throughout the Missouri Basin Region. Dissolved-solids concentration as much as 30,000 milligrams per liter has been measured in aquifers in glacial deposits in Montana. Saline water is common in sandstone aquifers in Wyoming, North Dakota, and South Dakota; maximum reported concentration is 280,000 milligrams per liter in water from the Tensleep Sandstone in Wyoming. Limestone contains saline water in many areas; maximum dissolved-solids concentration is about 350,000 milligrams per liter for the Madison Group in the Williston Basin in North Dakota. Comprehensive water-management planning in the Missouri Basin Region will require periodic or continuing inventory of precipitation, streamflow, surface-water storage, and ground water. Water demands for irrigation, industrial, public supply, and rural use are increasing rapidly. Reliance on ground-water supplies is increasing even though in many areas the ground water is still mostly undeveloped. Optimal use of water supplies will require the establishment of realistic goals and carefully conceived water-management plans, each of which will necessarily be based on an adequate baseline of hydrologic data and knowledge of the highly variable hydrologic systems in the region.

Colorado, Iowa, Kansas, Minnesota, Missouri, Monta

Hydrologic maps of Ogallala Aquifer, west-central Kansas, 1979-81

A mathematical technique, called kriging, was programmed for a computer to interpolate hydrologic data based on a network of measured values in west-central Kansas. The computer program generated estimated values at the center of each 1-mile section in the Western Kansas Groundwater Management District No. 1 and facilitated contouring of selected hydrologic data that are needed in the effective management of ground water for irrigation. The kriging technique produced various maps that illustrated hydrologic conditions in the Ogallala aquifer, the principal source of water in west-central Kansas. Maps of the aquifer, which use a 3-year average, included the 1979-81 water-table altitudes, which ranged from about 2,580 to 3,720 feet; the 1979-81 saturated thicknesses, which ranged from about 0 to 250 feet; and the percentage changes in saturated thickness from 1950 to 1979-81, which ranged from about a 40-percent increase to a 100-percent decrease. A map showing errors of estimate also was provided as a measure of reliability for the 1979-81 water-table altitudes. Errors of estimate ranged from 2 to 24 feet. (USGS)

Open-File Report

High-quality unsaturated zone hydraulic property data for hydrologic applications

In hydrologic studies, especially those using dynamic unsaturated zone moisture modeling, calculations based on property transfer models informed by hydraulic property databases are often used in lieu of measured data from the site of interest. Reliance on database-informed predicted values has become increasingly common with the use of neural networks. High-quality data are needed for databases used in this way and for theoretical and property transfer model development and testing. Hydraulic properties predicted on the basis of existing databases may be adequate in some applications but not others. An obvious problem occurs when the available database has few or no data for samples that are closely related to the medium of interest. The data set presented in this paper includes saturated and unsaturated hydraulic conductivity, water retention, particle-size distributions, and bulk properties. All samples are minimally disturbed, all measurements were performed using the same state of the art techniques and the environments represented are diverse.

Water Resources Research

The US Geological Survey stream-gaging program in west-central Florida

The results of a study of the network of the stream-gaging program in west-central Florida are documented. Selected hydrologic data, including drainage area, period of record, and mean annual flow were compiled for the 57 continuous-record gaging stations which were active in 1985. Additionally, selected hydrologic data for 20 discontinued gaging stations are included. Data uses and funding sources were identified for the stations currently being operated in west-central Florida with a budget of $320,000. All stations have been identified as having valid and needed uses, all stations are properly funded, and no short-term project stations exist within the stream-gaging program. On the basis of the analysis, it was concluded that all stations in the present stream-gaging program should be continued in operation. Future studies also will be required because of changes in demands for streamflow information with subsequent addition and deletion of gaging stations. (USGS)

Water-Resources Investigations Report

Framework for a U.S. Geological Survey Hydrologic Climate-Response Program in Maine

This report presents a framework for a U.S. Geological Survey (USGS) hydrologic climate-response program designed to provide early warning of changes in the seasonal water cycle of Maine. Climate-related hydrologic changes on Maine's rivers and lakes in the winter and spring during the last century are well documented, and several river and lake variables have been shown to be sensitive to air-temperature changes. Monitoring of relevant hydrologic data would provide important baseline information against which future climate change can be measured. The framework of the hydrologic climate-response program presented here consists of four major parts: (1) identifying homogeneous climate-response regions; (2) identifying hydrologic components and key variables of those components that would be included in a hydrologic climate-response data network - as an example, streamflow has been identified as a primary component, with a key variable of streamflow being winter-spring streamflow timing; the data network would be created by maintaining existing USGS data-collection stations and establishing new ones to fill data gaps; (3) regularly updating historical trends of hydrologic data network variables; and (4) establishing basins for process-based studies. Components proposed for inclusion in the hydrologic climate-response data network have at least one key variable for which substantial historical data are available. The proposed components are streamflow, lake ice, river ice, snowpack, and groundwater. The proposed key variables of each component have extensive historical data at multiple sites and are expected to be responsive to climate change in the next few decades. These variables are also important for human water use and (or) ecosystem function. Maine would be divided into seven climate-response regions that follow major river-basin boundaries (basins subdivided to hydrologic units with 8-digit codes or larger) and have relatively homogeneous climates. Key hydrologic variables within each climate-response region would be analyzed regularly to maintain up-to-date analyses of year-to-year variability, decadal variability, and longer term trends. Finally, one basin in each climate-response region would be identified for process-based hydrologic and ecological studies.

Open-File Report

A framework for effective use of hydroclimate models in climate-change adaptation planning for managed habitats with limited hydrologic response data

Climate-change adaptation planning for managed wetlands is challenging under uncertain futures when the impact of historic climate variability on wetland response is unquantified. We assessed vulnerability of Modoc National Wildlife Refuge (MNWR) through use of the Basin Characterization Model (BCM) landscape hydrology model, and six global climate models, representing projected wetter and drier conditions. We further developed a conceptual model that provides greater value for water managers by incorporating the BCM outputs into a conceptual framework that links modeled parameters to refuge management outcomes. This framework was used to identify landscape hydrology parameters that reflect refuge sensitivity to changes in (1) climatic water deficit (CWD) and recharge, and (2) the magnitude, timing, and frequency of water inputs. BCM outputs were developed for 1981–2100 to assess changes and forecast the probability of experiencing wet and dry water year types that have historically resulted in challenging conditions for refuge habitat management. We used a Yule’s Q skill score to estimate the probability of modeled discharge that best represents historic water year types. CWD increased in all models across 72.3–100 % of the water supply basin by 2100. Earlier timing in discharge, greater cool season discharge, and lesser irrigation season water supply were predicted by most models. Under the worst-case scenario, moderately dry years increased from 10–20 to 40–60 % by 2100. MNWR could adapt by storing additional water during the cool season for later use and prioritizing irrigation of habitats during dry years.

California

Framework for a U.S. Geological Survey hydrologic climate-response program in Maine

It is important to monitor hydrologic systems in the United States that could change dramatically over the short term as a result of climate change. Many ecological effects of climate change can be understood only if hydrologic data networks are in place. Because of its humid, temperate climate and its substantial annual snowpack, Maine’s seasonal water cycle is sensitive to air temperature changes (Hodgkins and others, 2003). Monitoring of relevant hydrologic data would provide important baseline information against which future climate change can be measured. A series of recent investigations by the U.S. Geological Survey (USGS) has documented changes in several components of the water cycle, including earlier snowmelt runoff in Maine during the last 30 to 40 years (Hodgkins and others, 2003), earlier lake- and river-ice breakups (Hodgkins and others, 2002; Hodgkins and others, 2005), and a denser and thinner late-winter snowpack (Hodgkins and Dudley, 2006). Snowmelt runoff timing was measured as the date, each year, by which half of the total winter-spring streamflow passed a streamflow-gaging station. Historical snowmelt runoff timing for the Piscataquis River in central Maine is shown in figure 1 as an example. Results of climate projections input to hydrologic models indicate that hydrologic trends, such as earlier spring snowmelt runoff, are expected to continue into the future (Hayhoe and others, 2007). These trends could affect species at the southern edge of their range in Maine, such as Atlantic salmon and Canada lynx, and may also affect availability of water for human use. This fact sheet describes the framework of a hydrologic climate-response program that would improve understanding of the effects of future climate change in Maine.

Maine

Review of the hydrologic data-collection network in the St. Joseph River basin, Indiana

The St. Joseph River Basin data-collection network in the St. Joseph River for streamflow, lake, ground water, and climatic stations was reviewed. The network review included only the 1700 sq mi part of the basin in Indiana. The streamflow network includes 11 continuous-record gaging stations and one partial-record station. Based on areal distribution, lake effect , contributing drainage area, and flow-record ratio, six of these stations can be used to describe regional hydrology. Gaging stations on lakes are used to collect long-term lake-level data on which to base legal lake levels, and to monitor lake-level fluctuations after legal levels are established. More hydrogeologic data are needed for determining the degree to which grouhd water affects lake levels. The current groundwater network comprises 15 observation wells and has four purposes: (1) to determine the interaction between groundwater and lakes; (2) to measure changes in groundwater levels near irrigation wells; (3) to measure water levels in wells at special purpose sites; and (4) to measure long-term changes in water levels in areas not affected by pumping. Seven wells near three lakes have provided sufficient information for correlating water levels in wells and lakes but are not adequate to quantify the effect of groundwater on lake levels. Water levels in five observation wells located in the vicinity of intensive irrigation are not noticeably affected by seasonal withdrawals. The National Weather Sevice operates eight climatic stations in the basin primarily to characterize regional climatic conditions and to aid in flood forecasting. The network meets network-density guidelines established by the World Meterological Organization for collection of precipitation and evaporation data but not guidelines suggested by the National Weather Service for density of precipitation gages in areas of significant convective rainfalls. (Author 's abstract)

Indiana