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At least 199 records · Page 11Linked to original sources
USGS2013

Assessment of water-quality data from Long Lake National Wildlife Refuge, North Dakota--2008 through 2012

ong Lake National Wildlife Refuge, located in south-central North Dakota, is an important habitat for numerous migratory birds and waterfowl, including several threatened or endangered species. The refuge is distinguished by Long Lake, which is approximately 65 square kilometers and consists of four primary water management units. Water levels in the Long Lake units are maintained by low-level dikes and water-control structures, which after construction during the 1930s increased the water-storage capacity of Long Lake and reduced the frequency and volume of flushing flows downstream. The altered water regime, along with the negative precipitation:evaporation ratio of the region, may be contributing to the accumulation of water-borne chemical constituents such as salts, trace metals, and other constituents, which at certain threshold concentrations may impair aquatic plant, invertebrate, and bird communities of the refuge. The refuge’s comprehensive conservation planning process identified the need for water-quality monitoring to assess current (2013) conditions, establish comparative baselines, evaluate changes over time (trends), and support adaptive management of the wetland units. In 2008, the U.S. Geological Survey, U.S. Fish and Wildlife Service, and North Dakota Department of Health began a water-quality monitoring program at Long Lake National Wildlife Refuge to address these needs. Biweekly water-quality samples were collected for ions, trace metals, and nutrients; and in situ sensors and data loggers were installed for the continuous measurement of specific conductance and water depth. Long Lake was characterized primarily by sodium, bicarbonate, and sulfate ions. Overall results for total alkalinity and hardness were 580 and 329 milligrams per liter, respectively; thus, Long Lake is considered alkaline and classified as very hard. The mean pH and sodium adsorption ratio for Long Lake were 8.8 and 10, respectively. Total dissolved solids concentrations averaged approximately 1,750 milligrams per liter, and ranged from 117 to 39,700 milligrams per liter. Twelve of the 14 trace metals detected in the water samples had established North Dakota water-quality standards for aquatic life, and only aluminum and copper consistently exceeded these criteria. Aluminum is considered harmful to aquatic biota in acidic (pH less than 5.5) systems and most of the copper standard exceedances were collected from highly concentrated waters because of evaporation and seasonally low water levels. Concentrations for various forms of nitrogen and phosphorus generally were similar to reported regional values. Specific conductance of Long Lake varied seasonally and annually both within and among management units, with values ranging from less than 500 to nearly 40,000 microsiemens per centimeter at 25 degrees Celsius. Long Lake was characterized by consistent seasonal patterns of increasing specific conductance from spring (March and April) to fall (September and October), with levels stabilizing through the end of the sampling season (November). These seasonal patterns in specific conductance were associated with decreasing water levels throughout the summer due primarily to evaporation and continuous water releases through the Unit 1 outlet structure, which resulted in the concentration of salts. Specific conductance of each unit, along with water levels, also varied among years. Overall, specific conductance levels were greatest during the drier year of 2008 when water levels were low. Specific conductance levels were lowest during the spring of 2009 following above-average volumes of fresh water from snowmelt runoff. Comparisons of specific conductance among sample sites that were spatially distributed within each management unit suggested that spatial variability within units was low except for areas associated with local inflows. Data collected during this study revealed consistent seasonal patterns and low within-unit spatial variability of specific conductance. Based on these data results, future sample collection efforts may be reduced, as well as the number of sample locations, to limit sampling costs. Water-quality samples collected monthly or seasonally during the growing season (spring, summer, and fall) from a single representative location within each water-management unit should provide sufficient data to assess seasonal changes in water-quality over time and provide information for Long Lake management decisions.

North Dakota↗
USGS1947

Major winter and nonwinter floods in selected basins in New York and Pennsylvania

The scientific design of flood-control works is based on an evaluation of the hydrologic factors basic to flood events, particularly how rainfall and snow runoff, soil conditions, and channel influences can combine to produce greater or lesser floods. For this purpose an analysis of the pertinent hydrologic data is needed. The methods of analysis adopted should conform as closely as possible to those already in use and must be adapted to the quality of the available information. Maximum floods in 8 basins in New York and Pennsylvania during the winter and nonwinter months were studied, a total of 21 floods. The most outstanding winter flood of record in the North Atlantic region was that of March 1936. Rainfall plus snow melt in the basins studied ranged between 3.04 and 6.87 inches, and associated volumes of direct runoff from 1.88 to 5.63 inches. Winter floods have a common characteristic in their relation to freezing temperature. The antecedent periods, representing a period of snow accumulation and frost penetration, are below freezing, and the flood itself is contemporaneous with a period of above-freezing temperatures, usually associated with rain, during which the previously accumulated snow is melted. A second common characteristic of major winter floods is their tendency to be associated with widespread causal meteorologic conditions. There was a more complete conversion of rainfall and snow melt into runoff during the winter storms studied than during the wettest nonwinter flood. Snow melt during winter floods ranged from 0.04 to 0.07 inch per degree-day above 32° F. The depth of mean areal rainfall produced by the nonwinter storms studied ranged from 3.05 to 4.96 inches. The maximum 24-hour quantity at single stations was 14 inches, which was measured during the storm of July 1935 in New York. The volume of direct runoff ranged between 1.39 and 3.41 inches. The portion of rainfall that was converted into runoff varied in accordance with the rate of antecedent base flow, expressed in second-feet per square mile, and emphasized the influence of antecedent conditions. The average volume of direct runoff during winter floods was 4.24 inches, and the average during nonwinter floods was 2.44 inches. The latter, however, were more concentrated as to time, tending to compensate for large volume of runoff in winter, so that the crest rates of direct runoff averaged 0.056 inches per hour during the winter and 0.051 inches during the nonwinter period.

New York, Pennsylvania↗
USGS2004

Estimating monthly, annual, and low 7-day, 10-year streamflows for ungaged rivers in Maine

Regression equations to estimate monthly, annual, and low 7-day, 10-year (7Q10) streamflows were derived for rivers in Maine. The derived regression equations for estimating mean monthly, mean annual, median monthly, median annual, and low 7Q10 streamflows for ungaged rivers in Maine presented in this report supersede those derived in previous studies. Twenty-six U.S. Geological Survey streamflow-gaging stations on unregulated, rural rivers in Maine with 10 years or more of recorded streamflow were used to develop the regression equations. Ordinary least squares (OLS) regression techniques were used to select the explanatory variables (basin and climatic characteristics) that would appear in the final regression equations. OLS regression of all possible subsets was done with 62 explanatory variables for each of 27 response variables. Five explanatory variables were chosen for the final regression equations: drainage basin area, areal fraction of the drainage basin underlain by sand and gravel aquifers, distance from the coast to the drainage basin centroid, mean drainage basin annual precipitation, and mean drainage basin winter precipitation (the sum of mean monthly precipitation for December, January, and February). Generalized least-squares regression techniques were used to derive the final coefficients and measures of uncertainty for the regression equations. The forms of many of the derived regression equations indicate some physical, mechanistic processes. Drainage basin area is the most statistically important explanatory variable and appears in all derived regression equations. Monthly streamflows are related inversely to the distance from the coast to the drainage basin centroid during December, January, February, and March; that is, the closer a river basin is to the coast, the higher monthly streamflows are per unit drainage basin area during the winter. The relation reverses in May when higher streamflows are attributed to basins farther from the coast. These relations are consistent with colder, inland drainage basins storing more water in snowpack during the winter and releasing it in the spring. The monthly streamflows (and low 7Q10) during July, August, September, and October are related positively to areal fraction of the drainage basin underlain by sand and gravel aquifers. In general, sand and gravel aquifers underlying Maine river basins have excellent water-yielding characteristics and can provide water to streams during low-flow conditions in the summer and early fall.

Maine↗
USGS2007

Wave-driven spatial and temporal variability in sea-floor sediment mobility in the Monterey Bay, Cordell Bank, and Gulf of the Farallones National Marine Sanctuaries

Wind and wave patterns affect many aspects of continental shelves and shorelines geomorphic evolution. Although our understanding of the processes controlling sediment suspension on continental shelves has improved over the past decade, our ability to predict sediment mobility over large spatial and temporal scales remains limited. The deployment of robust operational buoys along the U.S. West Coast in the early 1980s provides large quantities of high-resolution oceanographic and meteorologic data. By 2006, these data sets were long enough to clearly identify long-term trends and compute statistically significant probability estimates of wave and wind behavior during annual and interannual climatic cycles (that is, El Niño and La Niña). Wave-induced sediment mobility on the shelf and upper slope off central California was modeled using synthesized oceanographic and meteorologic data as boundary input for the Delft SWAN model, sea-floor grain-size data provided by the usSEABED database, and regional bathymetry. Differences in waves (heights, periods, and directions) and winds (speeds and directions) between El Niño and La Niña months cause temporal and spatial variations in peak wave-induced bed shear stresses. These variations, in conjunction with spatially heterogeneous unconsolidated sea-floor sedimentary cover, result in predicted sediment mobility widely varying in both time and space. These findings indicate that these factors have significant consequences for both geological and biological processes.

California↗
USGS2017

A land data assimilation system for sub-Saharan Africa food and water security applications

Seasonal agricultural drought monitoring systems, which rely on satellite remote sensing and land surface models (LSMs), are important for disaster risk reduction and famine early warning. These systems require the best available weather inputs, as well as a long-term historical record to contextualize current observations. This article introduces the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS), a custom instance of the NASA Land Information System (LIS) framework. The FLDAS is routinely used to produce multi-model and multi-forcing estimates of hydro-climate states and fluxes over semi-arid, food insecure regions of Africa. These modeled data and derived products, like soil moisture percentiles and water availability, were designed and are currently used to complement FEWS NET’s operational remotely sensed rainfall, evapotranspiration, and vegetation observations. The 30+ years of monthly outputs from the FLDAS simulations are publicly available from the NASA Goddard Earth Science Data and Information Services Center (GES DISC) and recommended for use in hydroclimate studies, early warning applications, and by agro-meteorological scientists in Eastern, Southern, and Western Africa.

Scientific Data↗
USGS2004

Comparison of methods for determining streamflow requirements for aquatic habitat protection at selected sites on the Assabet and Charles Rivers, Eastern Massachusetts, 2000-02

Four methods used to determine streamflow requirements for habitat protection at nine critical riffle reaches in the Assabet River and Charles River Basins were compared. The methods include three standard setting techniques?R2Cross, Wetted Perimeter, and Tennant?and a diagnostic method, the Range of Variability Approach. One study reach is on the main stem of the Assabet River, four reaches are on tributaries to the Assabet River (Cold Harbor Brook, Danforth Brook, Fort Meadow Brook, and Elizabeth Brook), three are on the main stem of the Charles River, and one is on a tributary to the Charles River (Mine Brook). The strength of the R2Cross and Wetted-Perimeter methods is that they may be applied at ungaged locations whereas the Tennant method and the Range of Variability Approach require a period of streamflow record for analysis. Fish community assessments conducted at or near riffle sites in flowing reaches of the Assabet River and Charles River Basins were used to indicate ecological conditions. The fish communities in the main stem and tributary reaches of both the Assabet and Charles River Basins indicated degraded aquatic ecosystems. However, the degree of degradation differs between the two basins. The extreme predominance of tolerant, generalist species in the Charles River fish community demon-strates the cumulative impacts of flow, habitat, and water-chemistry degradation, combined with the effects of nearby impoundments and changing land use. The range of discharges for nine ungaged riffle reaches defined by the median R2Cross 3-of-3 criteria, R2Cross 2-of-3 criteria, and Wetted-Perimeter streamflow requirements, was 0.86 cubic foot per second per square mile, 0.18 cubic foot per second per square mile, and 0.23 cubic foot per second per square mile, respectively. Application of R2Cross and Wetted-Perimeter methods to sites with altered streamflows or at sites that are riffles only at low to moderate flows can result in a greater variability of streamflow requirements than would result if the methods were applied to riffles on natural channels with unaltered streamflows. The R2Cross 2-of-3 criteria and the Wetted-Perimeter streamflow requirements for the Assabet and Charles River sites show narrower interquartile ranges and lower median streamflow requirements than for 10 index streamflow-gaging stations in southern New England. This is especially evident for the R2Cross 2-of-3 criteria and Wetted-Perimeter results that were close to half of the flow requirements determined at the 10 southern New England stations. The R2Cross and Wetted-Perimeter methods were also compared to the Range of Variability Approach analysis and the Tennant Method. The median R2Cross 3-of-3 criteria streamflow requirement for the nine riffles is close to the 75th percentile of the monthly mean flows during the summer low-flow period from six streamflow-gaging stations near the Assabet and Charles River Basins having mostly unaltered flow. This streamflow requirement is close to the median Tennant 40-percent-flow requirement for good habitat condi-tion for the same six nearby stations. The R2Cross 2-of-3 criteria and Wetted-Perimeter results were less than the 25th-percentile of monthly mean flows during the summer months for the six stations. These streamflow requirements are in the poor habitat range as indicated by a Tennant analysis of the same six stations. These comparisons indicate that the R2Cross and Wetted-Perimeter methods underestimate streamflow requirements when applied to sites in smaller drainage areas and channels that are runs at higher flows.

Scientific Investigations Report↗
USGS2011

Hydrogeologic framework, groundwater movement, and water budget in the Chimacum Creek basin and vicinity, Jefferson County, Washington

This report presents information used to characterize the groundwater flow system in the Chimacum Creek basin. It includes descriptions of the geology and hydrogeologic framework; groundwater recharge and discharge; groundwater levels and flow directions; seasonal fluctuations in groundwater level; interactions between aquifers and the surface-water system; and a groundwater budget. The study area covers 124 square miles in northeastern Jefferson County, Washington, and includes the Chimacum Creek basin, which drains an area of about 37 square miles. The area is underlain by a north-thickening sequence of unconsolidated glacial and interglacial deposits that overlie sedimentary and igneous bedrock units that crop out along the margins and western interior of the study area. Six hydrogeologic units consisting of unconsolidated aquifers and confining units, along with an underlying bedrock unit, were identified. A surficial hydrogeologic map was developed and used with well information from 187 drillers' logs to construct 4 hydrogeologic sections, and maps showing the extent and thickness of the units. Natural recharge was estimated using precipitation-recharge relation regression equations developed for western Washington, and estimates were calculated for return flow from data on domestic indoor and outdoor use and irrigated agriculture. Results from synoptic streamflow measurements and water table elevations determined from monthly measurements at monitoring wells are presented and compared with those from a study conducted during 2002-03. A water budget was calculated comprising long-term average recharge, domestic public-supply withdrawals and return flow, self-supplied domestic withdrawals and return flow, and irrigated agricultural withdrawals and return flow.

Washington↗
USGS2012

Hydrologic, water-quality, and biological characteristics of the North Fork Flathead River, Montana, water years 2007-2008

In water year 2007, the U.S. Geological Survey, in cooperation with the National Park Service, began a 2-year study to collect hydrologic, water-quality, and biological data to provide a baseline characterization of the North Fork Flathead River from the United States-Canada border to its confluence with the Middle Fork of the Flathead River near Columbia Falls, Montana. Although mining in the Canadian portion of the North Fork Basin was banned in 2010 by a Memorandum of Understanding issued by the Province of British Columbia, baseline characterization was deemed important for the evaluation of any potential future changes in hydrology, water quality, or aquatic biology in the basin. The North Fork Basin above Columbia Falls (including Canada) drains an area of 1,564 square miles, and the study area encompasses the portion of the basin in Montana, which is 1,126 square miles. Seasonal patterns in the hydrology of the North Fork are dominated by the accumulation and melting of seasonal snowpack in the basin. Low-flow conditions occurred during the late-summer, fall, and winter months, and high-flow conditions coincided with the spring snowmelt. Substantial gains in streamflow occurred along the study reach of the North Fork, 85 percent of which were accounted for by tributary inflows during low-flow conditions, indicating unmeasured streamflow inputs along the main stem were 15 percent or less.

Montana↗
USGS2013

Potential reductions of street solids and phosphorus in urban watersheds from street cleaning, Cambridge, Massachusetts, 2009-11

Material accumulating and washing off urban street surfaces and ultimately into stormwater drainage systems represents a substantial nonpoint source of solids, phosphorus, and other constituent loading to waterways in urban areas. Cost and lack of usable space limit the type and number of structural stormwater source controls available to municipalities and other public managers. Non-structural source controls such as street cleaning are commonly used by cities and towns for construction, maintenance and aesthetics, and may reduce contaminant loading to waterways. Effectiveness of street cleaning is highly variable and potential improvements to water quality are not fully understood. In 2009, the U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, the U.S. Environmental Protection Agency, and the city of Cambridge, Massachusetts, and initiated a study to better understand the physical and chemical nature of the organic and inorganic solid material on street surfaces, evaluate the performance of a street cleaner at removing street solids, and make use of the Source Loading and Management Model (SLAMM) to estimate potential reductions in solid and phosphorus loading to the lower Charles River from various street-cleaning technologies and frequencies. Average yield of material on streets collected between May and December 2010, was determined to be about 740 pounds per curb-mile on streets in multifamily land use and about 522 pounds per curb-mile on commercial land-use streets. At the end-of-winter in March 2011, about 2,609 and 4,788 pounds per curb-mile on average were collected from streets in multifamily and commercial land-use types, respectively. About 86 percent of the total street-solid yield from multifamily and commercial land-use streets was greater than or equal to 0.125 millimeters in diameter (or very fine sand). Observations of street-solid distribution across the entire street width indicated that as much as 96 percent of total solids resided within 9 feet of the curb. Median accumulation rates of street solids and median washoff of street solids after rainstorms on multifamily and commercial land-use streets were also similar at about 33 and 22 pounds per curb-mile per day, and 35 and 40 percent, respectively. Results indicate that solids on the streets tested in Cambridge, Mass., can recover to pre-rainstorm yields within 1 to 3 days after washoff. The finer grain-size fractions tended to be more readily washed from the roadway surfaces during rainstorms. Street solids in the coarsest grain-size fraction on multifamily streets indicated an average net increase following rainstorms and are likely attributed to debris run-on from trees, lawns, and other plantings commonly found in residential areas. In seven experiments between May and December 2010, the median removal efficiency of solids from street surfaces following a single pass by a regenerative-air street cleaner was about 82 percent on study sites in the multifamily land-use streets and about 78 percent on the commercial land-use streets. Median street-solid removal efficiency increased with increasing grain size. This type of regenerative-air street cleaner left a median residual street-solid load on the street surface of about 100 pounds per curb-mile. Median concentrations of organic carbon and total phosphorus (P) on multifamily streets were about 35 and 29 percent greater, respectively, than those found on commercial streets. The median total mass of organic carbon and total P in street solids on multifamily streets was 68 and 75 percent greater, respectively, than those found on commercial streets. More than 87 percent of the mass of total P was determined to be in solids greater than or equal to 0.125 millimeters in diameter for both land-use types. The median total accumulation rate for total P on multifamily streets was about 5 times greater than on commercial streets. Total P accumulation in the medium grain-size fraction was nearly the same for streets within both land-use types at 0.004 pounds per curb-mile per day. Accumulation rates within the coarsest and finest grain-size fractions on multifamily streets were about 11 and 82 times greater than those on the commercial streets. Median washoff of total P was 58 and 48 percent from streets in multifamily and commercial land-use types, respectively, and generally increased with decreasing grain size. Total P median reductions resulting from a single pass of a regenerative-air street cleaner on streets in multifamily and commercial land-use types were about 82 and 62 percent, respectively, and were similar in terms of grain size between both land-use types. A Source Loading and Management Model for Microsoft Windows (WinSLAMM) was applied to a 21.8 acre subcatchment in Cambridge, Mass. The subcatchment area consists of mostly commercial and multifamily land-use types to evaluate the potential reductions of total and particulate solids, and P attributed to street cleaning. Rainwater runoff from rooftops represented between 20 and 50 percent of the total basin runoff. Street surfaces only accounted for about 20 percent of the total basin runoff. Monthly applications of mechanical-brush and vacuum-assisted street cleaners within the subcatchment as defined by SLAMM for areas with long-term (24-hour) on-street parking and monthly parking controls using five average climatic years resulted in total solid reductions of about 3 and 5 percent, respectively. Simulating the regenerative-air street cleaner tested as part of this study resulted in total solid reductions of about 16 percent. Increasing street cleaning frequency to three times weekly increased total solids removal for mechanical-brush, vacuum-assisted, and regenerative-air street cleaners to about 6, 14, and 19 percent, respectively. Monthly applications of mechanical-brush, vacuum-assisted, and regenerative-air street cleaners within the subcatchment resulted in total P reductions of about 1, 3, and 8 percent, respectively. A street cleaning frequency of three times each week for each of the three street-cleaner types increased total P removal to about 3, 7, and 9 percent, respectively.

Massachusetts↗
USGS2025

Bison population dynamics, harvest, and conflict potential under feedground management alternatives at the National Elk Refuge in Jackson, Wyoming

Bison bison (bison) were once abundant across North America but declined due to overharvesting in the late 1800s. The reintroduced population in and around Jackson, Wyoming has averaged 485 individuals between 2018–2023 and is the subject of a planning process to inform management strategies that will guide the U.S. Fish and Wildlife’s next “Bison and Elk Management Plan” for the National Elk Refuge. This small population may benefit from historical winter-feeding operations on the National Elk Refuge because those operations may increase overwinter survival and limit human-bison conflicts, which are the number of individual bison that engage in nuisance, damaging, or otherwise aggressive behaviors with humans and livestock, that may lead to culling and other sources of mortality (for example, vehicle collisions). To inform the next “Bison and Elk Management Plan,” the U.S. Geological Survey used a population model to evaluate five management alternatives for bison and Cervus elaphus canadensis (elk) feedground operations that included continuing the elk and bison feeding program, immediately stopping the feeding program, and three other alternatives that would phase out the feeding program after a period of time. The results indicate that the bison population would be expected to decline over the next 20 years under all alternatives that stop feeding bison on the refuge. Further, this decline would lead to an associated reduction in bison harvest opportunities for resident, nonresident, and Tribal hunters. Finally, human-bison conflicts would also be expected to increase under the no feeding alternatives because bison may venture onto private lands in greater numbers if feed is not provisioned during winter months. In combination, these effects suggest that feeding may lead to better outcomes for bison over the next 20 years; however, these effects may be traded off against other downsides of the feedground program, such as increased rates of animal-to-animal contact on feedgrounds that can lead to disease transmission.

Wyoming↗
USGS2025

Bison population dynamics, harvest, and human conflict potential under feedground management alternatives at the National Elk Refuge in Jackson, Wyoming

Bison bison were once abundant across North America but declined due to overharvesting in the late 1800s. The reintroduced population in and around Jackson, Wyoming has averaged 485 individuals between 2018–2023 and is the subject of a planning process to inform management strategies that will guide the U.S. Fish and Wildlife’s next “Bison and Elk Management Plan” for the National Elk Refuge. This small population may benefit from historical winter-feeding operations on the National Elk Refuge because those operations may increase overwinter survival and limit human-bison conflicts, which are the number of individual bison that engage in nuisance, damaging, or otherwise aggressive behaviors with humans and livestock, that may lead to culling and other sources of mortality (for example, vehicle collisions). To inform the next “Bison and Elk Management Plan,” the U.S. Geological Survey used a population model to evaluate five management alternatives for bison and Cervus elaphus canadensis feedground operations that included continuing the elk and bison feeding program, immediately stopping the feeding program, and three other alternatives that would phase out the feeding program after a period of time. The results indicate that the bison population would be expected to decline over the next 20 years under all alternatives that stop feeding bison on the refuge. Further, this decline would lead to an associated reduction in bison harvest opportunities for resident, nonresident, and Tribal hunters. Finally, human-bison conflicts would also be expected to increase under the no feeding alternatives because bison may venture onto private lands in greater numbers if feed is not provisioned during winter months. In combination, these results suggest that feeding may lead to better outcomes for bison over the next 20 years; however, these effects may be traded off against other downsides of the feedground program, such as increased rates of animal-to-animal contact on feedgrounds that can lead to disease transmission.

Wyoming↗
USGS2006

Synthesis of monthly and annual streamflow records (water years 1950-2003) for Big Sandy, Clear, Peoples, and Beaver Creeks in the Milk River basin, Montana

To address concerns expressed by the State of Montana about the apportionment of water in the St. Mary and Milk River basins between Canada and the United States, the International Joint Commission requested information from the United States government about water that originates in the United States but does not cross the border into Canada. In response to this request, the U.S. Geological Survey synthesized monthly and annual streamflow records for Big Sandy, Clear, Peoples, and Beaver Creeks, all of which are in the Milk River basin in Montana, for water years 1950-2003. This report presents the synthesized values of monthly and annual streamflow for Big Sandy, Clear, Peoples, and Beaver Creeks in Montana. Synthesized values were derived from recorded and estimated streamflows. Statistics, including long-term medians and averages and flows for various exceedance probabilities, were computed from the synthesized data. Beaver Creek had the largest median annual discharge (19,490 acre-feet), and Clear Creek had the smallest median annual discharge (6,680 acre-feet). Big Sandy Creek, the stream with the largest drainage area, had the second smallest median annual discharge (9,640 acre-feet), whereas Peoples Creek, the stream with the second smallest drainage area, had the second largest median annual discharge (11,700 acre-feet). The combined median annual discharge for the four streams was 45,400 acre-feet. The largest combined median monthly discharge for the four creeks was 6,930 acre-feet in March, and the smallest combined median monthly discharge was 48 acre-feet in January. The combined median monthly values were substantially smaller than the average monthly values. Overall, synthesized flow records for the four creeks are considered to be reasonable given the prevailing climatic conditions in the region during the 1950-2003 base period. Individual estimates of monthly streamflow may have large errors, however. Linear regression was used to relate logarithms of combined annual streamflow to water years 1950-2003. The results of the regression analysis indicated a significant downward trend (regression line slope was -0.00977) for combined annual streamflow. A regression analysis using data from 1956-2003 indicated a slight, but not significant, downward trend for combined annual streamflow.

Scientific Investigations Report↗
USGS2017

Geomorphic response of the North Fork Stillaguamish River to the State Route 530 landslide near Oso, Washington

On March 22, 2014, the State Route 530 Landslide near Oso, Washington mobilized 8 million cubic meters of unconsolidated Pleistocene material, creating a valley‑spanning deposit that fully impounded the North Fork Stillaguamish River. The river overtopped the 8-meter high debris impoundment within 25 hours and began steadily incising a new channel through the center of the deposit. Repeat topographic surveys, sediment transport measurements, bedload transport models, and observations of downstream channel change were used to document the establishment of that new channel through the landslide and assess the potential for downstream aggradation or channel change that might increase downstream flood hazards. Efficient erosion of the landslide deposit, associated with the steep knickzone formed by the downstream edge of the deposit, resulted in the re-establishment of a 20–40 meters wide, deeply inset channel through the entire deposit by May 2014, 2 months after the landslide. The mean water-surface elevation of the channel through the landslide decreased 7 meters during that 2-month period, and was about 1 meter above the pre-landslide profile in July 2014. The 2014–15 flood season, which included flows near the 0.5 annual exceedance probability discharge (2-year flood), widened the channel tens of meters, and further lowered the water-surface profile 0.5 meter. The planform position evolved slowly as a result of 5–20-meter high banks predominantly composed of clay-rich, cohesive lacustrine material. Erosion of the landslide deposit delivered a total of 820 thousand metric tons of sediment to the North Fork Stillaguamish River over the 18 months following the landslide. The sediment delivery from the deposit was predominantly fine grained: 77 percent (by mass) of the eroded material was silt or clay (less than 0.063 millimeter [mm]), 19 percent sand (0.063–2 mm), and 4 percent pebbles and cobbles (greater than 2 mm). Over the 18 months following the landslide, the bedload at a site 5 kilometers downstream of the landslide was estimated to be 310±65 thousand metric tons, and the suspended load at that same site was estimated to be 990±110 thousand metric tons. These loads represent the combined input from the landslide and ambient upstream sources; over the study interval, landslide sediment made up about 20–40 percent of the bedload, and 65–85 percent of the suspended-sediment load at this site. At a site 70 kilometers downstream of the landslide, near the mouth of the main‑stem Stillaguamish River, suspended sediment loads were estimated to be about 1,440 thousand metric tons, of which about 600 thousand metric tons, or 30 percent, likely was derived from the landslide. The mass of landslide sediment in suspension at the mouth of the river, and the timing of arrival of that sediment, indicates that about 70 percent of the landslide sediment eroded during the study period was quickly transported through the entire basin, exiting into Puget Sound within weeks of initial entrainment. Empirical bedload transport equations, in conjunction with surficial grain-size data and output from a one‑dimensional hydraulic model, were used to estimate spatial trends in bedload transport capacity, highlighting areas where reach-scale conditions would be most likely to promote deposition of coarse landslide sediment. Transport capacities decreased sharply over a reach about 5 kilometers downstream of the landslide and remained relatively low over the next 10 kilometers downstream. However, the magnitude of calculated transport capacities are large relative to the coarse sediment input from the landslide, suggesting that substantial deposition of landslide sediment was not likely to occur. These assessments were corroborated by observations of channel change, which indicated that the downstream channel response to the landslide was modest and short-lived. The most pronounced downstream effects included a wedge of aggradation just downstream of the landslide, about 1 meter high and extending a kilometer downstream, and a 0.3-meter pulse of aggradation observed 5 kilometers downstream of the landslide. In both locations, peak aggradation and channel response occurred within about a month of the landslide, and both sites had largely recovered to pre-landslide conditions by July 2014. No substantial channel change clearly linked to the landslide was observed after July 2014 except for a modest fining of surficial gravel size distributions and continued recovery and incision of the reach just downstream of the landslide. The muted downstream response of the North Fork Stillaguamish River to the State Route 530 Landslide primarily can be attributed to the cohesive, silt- and clay-rich material that bounded most of the new channel. Although the river efficiently incised a new channel through the deposit, subsequent rates of lateral erosion were slowed by the tall, cohesive banks, limiting the total volume of sediment delivery. Once entrained, however, most landslide material was rapidly transported downstream in suspension with little geomorphic effect. Landslide material coarse enough to travel as bedload was predominantly sand and fine gravel, and sediment transport models and observations of downstream change indicated that the rate of coarse sediment delivery from the landslide did not exceed the rivers ability to transport that material. The generally muted downstream response to sediment delivery from the State Route 530 Landslide, as well as the mechanics of that delivery and response, were generally consistent with observations made following the intentional removal of constructed dams. The rate and efficiency of erosion from the landslide decreased over the period of analysis, as the new channel approached a quasi-equilibrium form. In the absence of additional hillslope activity, rates of erosion from the landslide are likely to be small compared to those over the first 18 months after the landslide. The modest channel response to the highest rates of sediment delivery, and rapid recovery thereafter, indicate that the river should be able to convey the continued supply of landslide-derived sediment effectively with little effect on the downstream morphology and flood risks.

Washington↗
USGS2025

Analysis of summer water temperatures of the lower Virgin River near Mesquite, Nevada, 2019–21

The lower Virgin River is a sandy, shallow reach of the Virgin River that flows from northern Arizona to Lake Mead in Nevada. The Virgin River hosts several native fish species, including two endangered fish, woundfin ( Plagopterus argentissimu ) and Virgin River chub ( Gila seminuda ). All native fish species in the lower Virgin River have experienced reductions in population sizes in the last several decades. Reduced stream flow (especially during summer low-flow conditions) often results in increased water temperatures, which can increase mortality, reduce breeding, limit population connectivity, and favor non-native fish species. This study investigated summer water temperatures and flow in the lower Virgin River near Mesquite, Nev., between Littlefield, Ariz., and Bunkerville, Nev., to evaluate how hydrologic conditions could be affecting native fish species. The 3-year monitoring project involved collection of continuous temperature and discrete discharge measurements at 15 sites from 2019 to 2021 during the summer months from June to September. Results indicate that the lower Virgin River is often greater than 5 degrees Celsius (°C) above the established critical thermal maximum of 31 °C, that the cooling effect of the Littlefield springs dissipates quickly downstream, and that water temperature is affected primarily by atmospheric conditions. Discharge and water temperature are poorly related at normal stable flow conditions.

Arizona, Nevada↗
USGS2023

Field observations and long short-term memory modeling of spectral wave evolution at living shorelines in Chesapeake Bay, USA

Living shorelines as a nature-based solution for climate change adaptation were constructed in many places around the world. The success of this type of projects requires long-term monitoring for adaptive management. The paper presents a novel framework leveraging scientific machine learning methods for accurate and rapid prediction of long-term hydrodynamic forcing impacting living shorelines using short-term measurements of water levels and wind waves in the largest estuary in the U.S. Different from existing data-driven wave prediction models focusing on significant wave heights, this study is focused on the prediction of wave energy spectra in shallow water using winds and tides as the input feature and short-term measurements of wave spectra and water depths as the label. Long Short-Term Memory (LSTM) models were developed using four-month wave measurements in the stormy seasons to predict integral wave parameters and energy spectra for multiple years. The developed models accurately predicted wave heights, peak periods, and energy spectra around the living shorelines, capturing complex wave dynamics, such as wave generation by wind, nonlinear wave-wave interactions, and depth-limited wave breaking in the shallow water of a large estuary. The validated models were then used to determine the long-term wave forcing impacting the living shorelines based on the modeled wave characteristics and spectra. Model results show that the surrogate models utilizing LSTM to predict wave spectra in the frequency domain enable long-term predictions of spectral wave evolution with a minimal computational cost. Our findings provide valuable insights into the efficacy of living shorelines in attenuating wave energy and demonstrate the utility of this approach in assessing the effectiveness of such living shoreline structures.

Applied Ocean Research↗
USGS2005

Sediment-transport investigations of the upper Yellowstone River, Montana, 1999 through 2001: Data collection, analysis, and simulation of sediment transport

The upper Yellowstone River in Montana is an important State and national water resource, providing recreational, agricultural, and commercial benefits. Floods in 1996 and 1997, with recorded peak discharges having recurrence intervals close to 100 years, caused substantial streambank erosion and hill- slope mass wasting. Large quantities of sand-, gravel-, and cobble-sized material entrained by the flood flows became flood-bar deposits, creating a source of sediment available for transport during future floods. The flood damage and resulting sedimentation raised concerns about potential streambank-stabilization projects and how the river and riparian corridor might be managed in the future. The U.S. Geological Survey, in cooperation with the Park Conservation District, the Montana Department of Transportation, and the U.S. Army Corps of Engineers, investigated sediment transport in the upper Yellowstone River near Livingston from 1999 through 2001 as part of a cumulative effects study to provide a scientific basis for future river management decisions. The purpose of this report is to present the results of data collection, analysis, and simulation of sediment transport for the upper Yellowstone River. The study area included a 13.5-mile study reach of the upper Yellowstone River where substantial sediment transport occurred in 1996 and 1997. In this study area, the upper Yellowstone River is a high gradient, coarse-bed stream having a slope of about 0.0028 foot per foot or more than 14 feet per mile. The study area drains about 3,551 square miles, and runoff results primarily from snowmelt during the spring and summer months. As part of sediment-transport investigations, the U.S. Geological Survey surveyed river cross sections, characterized streambed-material particle size using particle counts and sieve analyses, and collected bedload- and suspended-sediment data during three runoff seasons (1999-2001). Data were collected for stream discharges that ranged from 2,220 cubic feet per second (typical of pre- and post-runoff discharge) to 25,100 cubic feet per second (about 125 percent of bankfull discharge). The distribution of streambed-material particle size was determined, and sediment-transport curves for bedload discharge, suspended-sediment discharge, and total-sediment discharge were developed. The threshold values of streamflow and average stream velocity needed for initiation of bedload transport for selected sediment-size classes showed that little to no bedload was transported for an average stream velocity below about 3 feet per second, and the only particle size transported as bedload at that velocity was sand. Over the range of stream discharges sampled and with silt- and finer-sized particles excluded, bedload discharge averaged about 18 percent of the total-sediment discharge, equal to bedload discharge plus suspended-sediment discharge. At the lowest and highest stream discharges sampled, bedload was, respectively, less than about 2 percent and about 30 percent of the total-sediment discharge. Over the range of stream discharges sampled, the sand-sized part of the total suspended-sediment discharge averaged about 48 percent, where the total suspended-sediment discharge included sand-, silt- and finer-sized particles. At the lowest and highest stream discharges sampled, the sand-sized part of the total suspended-sediment discharge was, respectively, less than about 16 percent and about 50 percent of the total suspended-sediment discharge. The sediment-transport curves were compared to curves for selected sites in the western United States having drainage areas ranging from 21 square miles to over 20,000 square miles. Daily sediment loads transported at bankfull discharge were calculated for each site and results were plotted in relation to drainage area. Results based on the 1999-2001 data-collection period indicate that the estimated daily bedload transported at bankfull discharge in the upper Yellowstone River exceeded the envelope line that bounds the upper end of the data for other selected sites in the Northern Rocky Mountains and is similar in magnitude to that for selected sites in Alaska having braided channels and glacial and snowmelt runoff. Similar comparisons for suspended sediment indicate that daily suspended-sediment load at bankfull discharge is relatively high in the upper Yellowstone River, plotting slightly above the envelope line that bounds the upper end of the data for other selected sites in the Northern Rocky Mountains. Sediment data were used to develop individual transport equations for seven size classes of sediment ranging from small cobbles to very fine sand. A step-wise regression procedure relating sediment discharge to important hydraulic variables showed that average stream velocity was the only significant variable at the 95-percent confidence level. Bedload and suspended-sediment data and equations indicate that more sand is transported for a given velocity than any other particle size, and very little sand-size sediment load is transported below an average stream velocity of about 2.5 feet per second. Transport of coarser-sized sediment (limited to bedload) becomes very little for an average velocity less than about 3.5 feet per second. Results for the 1999-2001 data-collection period indicate that sediment transport in the upper Yellowstone River tends to be limited more by the transport capacity of the stream (capacity or transport limited), than to the availability of sediment in the watershed (supply limited). Sediment data collected and analyzed were used to simulate sediment transport in the study reach using the BRIdge Stream Tube model for Alluvial River Simulation, or BRI-STARS computer model. The model was calibrated and verified using selected data from historical runoff periods. Simulated total-sediment loads, on a reach-averaged basis, were in good agreement with the total-sediment loads determined from the transport curve for the 2-year flood hydrograph but were considerably smaller for the total-sediment loads determined from the transport curve for the 50-, 100-, and 500-year flood hydrographs. The differences probably were largely due to the inability of the model to simulate streambank erosion, hillslope mass-wasting, and other channel-widening processes, which had supplied substantial quantities of sediment to the channel during the 1996 and 1997 floods, and probably continued to contribute to the sediment load in the subsequent years (1999-2001) when the data were collected. Furthermore, the transport curve was applied beyond the measured data for the highest discharges, and may thus be unreliable. Also, the transport curve derived from only limited data may not apply over the full duration of the hydrograph and sediment might be transported over only a portion of the hydrograph, especially for rivers like the upper Yellowstone where snowmelt runoff predominates. The true sediment discharge is, therefore, unknown and might be closer to the simulated values than to the values calculated from the transport curve.

Montana↗
USGS2004

Ground-water and surface-water flow and estimated water budget for Lake Seminole, southwestern Georgia and northwestern Florida

Lake Seminole is a 37,600-acre impoundment formed at the confluence of the Flint and Chattahoochee Rivers along the Georgia?Florida State line. Outflow from Lake Seminole through Jim Woodruff Lock and Dam provides headwater to the Apalachicola River, which is a major supply of freshwater, nutrients, and detritus to ecosystems downstream. These rivers,together with their tributaries, are hydraulically connected to karst limestone units that constitute most of the Upper Floridan aquifer and to a chemically weathered residuum of undifferentiated overburden. The ground-water flow system near Lake Seminole consists of the Upper Floridan aquifer and undifferentiated overburden. The aquifer is confined below by low-permeability sediments of the Lisbon Formation and, generally, is semiconfined above by undifferentiated overburden. Ground-water flow within the Upper Floridan aquifer is unconfined or semiconfined and discharges at discrete points by springflow or diffuse leakage into streams and other surface-water bodies. The high degree of connectivity between the Upper Floridan aquifer and surface-water bodies is limited to the upper Eocene Ocala Limestone and younger units that are in contact with streams in the Lake Seminole area. The impoundment of Lake Seminole inundated natural stream channels and other low-lying areas near streams and raised the water-level altitude of the Upper Floridan aquifer near the lake to nearly that of the lake, about 77 feet. Surface-water inflow from the Chattahoochee and Flint Rivers and Spring Creek and outflow to the Apalachicola River through Jim Woodruff Lock and Dam dominate the water budget for Lake Seminole. About 81 percent of the total water-budget inflow consists of surface water; about 18 percent is ground water, and the remaining 1 percent is lake precipitation. Similarly, lake outflow consists of about 89 percent surface water, as flow to the Apalachicola River through Jim Woodruff Lock and Dam, about 4 percent ground water, and about 2 percent lake evaporation. Measurement error and uncertainty in flux calculations cause a flow imbalance of about 4 percent between inflow and outflow water-budget components. Most of this error can be attributed to errors in estimating ground-water discharge from the lake, which was calculated using a ground-water model calibrated to October 1986 conditions for the entire Apalachicola?Chattahoochee?Flint River Basin and not just the area around Lake Seminole. Evaporation rates were determined using the preferred, but mathematically complex, energy budget and five empirical equations: Priestley-Taylor, Penman, DeBruin-Keijman, Papadakis, and the Priestley-Taylor used by the Georgia Automated Environmental Monitoring Network. Empirical equations require a significant amount of data but are relatively easy to calculate and compare well to long-term average annual (April 2000?March 2001) pan evaporation, which is 65 inches. Calculated annual lake evaporation, for the study period, using the energy-budget method was 67.2 inches, which overestimated long-term average annual pan evaporation by 2.2 inches. The empirical equations did not compare well with the energy-budget method during the 18-month study period, with average differences in computed evaporation using each equation ranging from 8 to 26 percent. The empirical equations also compared poorly with long-term average annual pan evaporation, with average differences in evaporation ranging from 3 to 23 percent. Energy budget and long-term average annual pan evaporation estimates did compare well, with only a 3-percent difference between estimates. Monthly evaporation estimates using all methods ranged from 0.7 to 9.5 inches and were lowest during December 2000 and highest during May 2000. Although the energy budget is generally the preferred method, the dominance of surface water in the Lake Seminole water budget makes the method inaccurate and difficult to use, because surface water makes up m

Florida, Georgia↗
USGS2012

Effects of urban best management practices on streamflow and phosphorus and suspended-sediment transport on Englesby Brook in Burlington, Vermont, 2000-2010

An assessment of the effectiveness of several urban best management practice structures, including a wet extended detention facility and a shallow marsh wetland (together the "wet extended detention ponds"), was made using data collected from 2000 through 2010 at Englesby Brook in Burlington, Vermont. The purpose of the best management practices was to reduce high streamflows and phosphorus and suspended-sediment loads and concentrations and to increase low streamflows. Englesby Brook was monitored for streamflow, phosphorus, and suspended-sediment concentrations at a streamgage downstream of the best management practice structures for 5 years before the wet extended detention ponds were constructed in 2005 and for 4 years (phosphorus and suspended-sediment concentrations) or 5 years (streamflow) after they were constructed. The period after construction of the best management practice structures was wetter and had higher discharges than the period before construction. Despite the wetter conditions, streamflow duration curves provided evidence that the streamflow regime appeared to have shifted so that the percentages of low streamflows have increased and those of high streamflows may have slightly decreased. Two other hydrologic measures showed improvements in the years following construction of the best management practices: the percentage of annual discharge transported during the 3 days with highest discharges and the number of days with zero streamflow have both decreased. Evidence was mixed for the effectiveness of the best management practices in reducing phosphorus and suspended-sediment concentrations and loads. Annual phosphorus and suspended-sediment loads, monthly loads, low-streamflow concentrations, storm-averaged streamflow-adjusted concentrations, and total storm loads either did not change significantly or increased in the period after construction. These results likely were because of the wetter conditions in the period after construction. For example, monthly loads assessed using analysis of covariance, which compensated for the effects of streamflow on loads, suggested no difference in phosphorus or suspended-sediment loads between the two periods, whereas the comparison of monthly loads without factoring in streamflow showed an increase. This result could be viewed as evidence that the ponds may have mitigated the effect of greater discharges in the period after construction by preventing a corresponding increase in loads. In another analysis used to adjust for the difference in discharge between the two comparison periods, annual and monthly load results were grouped into dry and wet years. Large (50 percent) reductions in annual loads were observed when data from dry (or wet) years before construction were compared with data from dry (or wet) years after construction. When paired monthly loads of each constituent were grouped into dry and wet years, approximately the same number of months had increases as did decreases with the magnitudes of the decreases generally larger than the magnitudes of the increases. These differences in magnitude explain the decrease in annual loads for dry and wet years. The close association of phosphorus with suspended-sediment data suggested that most of the phosphorus was in the particulate form and was controlled by suspended-sediment dynamics.

Vermont↗