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At least 955 records · Page 53Linked to original sources

USGS2025

Most pinyon-juniper woodland species distributions are projected to shrink rather than shift under climate change

Pinyon–juniper (PJ) woodlands are among the most widespread ecosystems in rangelands of western North America, supporting diverse wildlife habitat, recreation, grazing, and cultural/spiritual enrichment. Anticipating future distribution shifts under changing climate will be critical to climate adaptation and conservation efforts in these ecosystems. Here, we evaluate drivers of PJ tree species’ distributions and project changes in response to future climate change. We developed species distribution models with dryland-focused predictors to project environmental suitability changes across the entirety of three pinyon and six juniper species ranges. We identify areas of robust suitability change by combining suitability projections from multiple emissions scenarios and time periods. PJ species’ suitabilities respond to many temperature and moisture covariates expected to change in the future. Projected responses among PJ species are highly variable, ranging from modest declines with concurrent gains for overall little net change to wide-ranging declines with no gains for overall range contractions. Environmental suitability is projected to decline broadly across the arid United States Southwest and remain relatively stable across the northern Great Basin and Colorado Plateau. Our results suggest unique responses of PJ species to future climate change. We found that species were projected to experience more losses than gains in suitability, for overall range shrinks rather than shifts. Land managers have the capacity to increase woodland resilience to drought, and our results can inform rangeland-wide management planning and conservation efforts in PJ woodlands.

Rangeland Ecology & Management↗

USGS2001

International collaboration: The cornerstone of satellite land remote sensing in the 21st century

Satellite land remotely sensed data are used by scientists and resource managers world-wide to study similar multidisciplinary earth science problems. Most of their information requirements can be met by a small number of satellite sensor types. Moderate-resolution resource satellites and low-resolution environmental satellites are the most prominent of these, and they are the focus of this paper. Building, launching, and operating satellite systems are very expensive endeavors. Consequently, nations should change the current pattern of independently launching and operating similar, largely redundant resource and environmental satellite systems in favor of true and full collaboration in developing, launching, operating, and sharing the data from such systems of the future. The past decade has seen encouraging signs of increasing international collaboration in earth remote sensing, but full collaboration has not yet been attempted. A general strategy to achieve such international collaboration is presented here, including discussion of potential obstacles, ideas for organizing and overseeing the long-term process toward collaboration, and short-term objectives whereby early successes critical to accomplishing long-term goals can be achieved.

Space Policy↗

USGS2019

Mercury exposure and altered parental nesting behavior in a wild songbird

Methylmercury is a neurotoxin and endocrine disruptor and may impair avian reproduction directly through embryotoxicity or by altering parental care behaviors. We studied mercury exposure and incubation behavior of free-living tree swallows (Tachycineta bicolor) nesting in artificial nest boxes. Using small temperature dataloggers, we measured incubation constancy (the proportion of each day the female spent incubating eggs), the number of incubation recesses taken per day, and the duration of incubation recesses. We also assessed maternal mercury exposure by measuring mercury concentrations in both blood and eggs. Females with higher mercury concentrations exhibited lower incubation constancy, took more frequent and shorter incubation recesses, and were more likely to take incubation recesses that caused nest temperature decreases that were likely to slow embryonic development. Overall, females that laid eggs with the highest observed mercury concentration (0.53 μg/g fww) spent an average of 12% less time incubating their eggs over the 14-day incubation period than females that laid eggs with the lowest mercury concentration (0.07 μg/g fww). Because less time spent incubating can lower egg temperatures, slow embryonic development, and potentially lengthen the incubation period, these results suggest that environmentally relevant mercury concentrations may negatively influence reproduction by altering parental nesting behaviors of wild songbirds

Environmental Science & Technology↗

USGS2009

What is a picture worth? A history of remote sensing

Remote sensing is the use of electromagnetic energy to measure the physical properties of distant objects. It includes photography and geophysical surveying as well as newer techniques that use other parts of the electromagnetic spectrum. The history of remote sensing begins with photography. The origin of other types of remote sensing can be traced to World War II, with the development of radar, sonar, and thermal infrared detection systems. Since the 1960s, sensors have been designed to operate in virtually all of the electromagnetic spectrum. Today a wide variety of remote sensing instruments are available for use in hydrological studies; satellite data, such as Skylab photographs and Landsat images are particularly suitable for regional problems and studies. Planned future satellites will provide a ground resolution of 10–80 m. Remote sensing is currently used for hydrological applications in most countries of the world. The range of applications includes groundwater exploration determination of physical water quality, snowfield mapping, flood-inundation delineation, and making inventories of irrigated land. The use of remote sensing commonly results in considerable hydrological information at minimal cost. This information can be used to speed-up the development of water resources, to improve management practices, and to monitor environmental problems.

Hydrological Sciences Bulletin↗

USGS2017

Submersed aquatic vegetation in Chesapeake Bay: Sentinel species in a changing world

Chesapeake Bay has undergone profound changes since European settlement. Increases in human and livestock populations, associated changes in land use, increases in nutrient loadings, shoreline armoring, and depletion of fish stocks have altered the important habitats within the Bay. Submersed aquatic vegetation (SAV) is a critical foundational habitat and provides numerous benefits and services to society. In Chesapeake Bay, SAV species are also indicators of environmental change because of their sensitivity to water quality and shoreline development. As such, SAV has been deeply integrated into regional regulations and annual assessments of management outcomes, restoration efforts, the scientific literature, and popular media coverage. Even so, SAV in Chesapeake Bay faces many historical and emerging challenges. The future of Chesapeake Bay is indicated by and contingent on the success of SAV. Its persistence will require continued action, coupled with new practices, to promote a healthy and sustainable ecosystem.

Chesapeake Bay↗

USGS2003

Seasonal and spatial distribution of bacterial biomass and the percentage of viable cells in a reservoir of Alabama

Spatial community dynamics of bacterioplankton were evaluated along the length of the former stream channel of Elledge Lake, a small reservoir in western Alabama. The reservoir was strongly stratified from April to October with up to a 10??C temperature difference across the 1 m deep metalimnion. Bacterial biomass was highest during late summer, with a general pattern of increasing abundance from the inflowing river (???10 ??g C l-1) to the dam (???20-30 ??g C l-1). Bacterial numbers also increased following a >10-fold increase in turbidity associated with a major precipitation event, although only ???10% of these cells were viable. The percentage of viable cells generally increased through the stratified period with 50-70% viable cells in late summer. Overall, an average of 38% of bacterial cells were viable, with a range from <20 to 70%. Although these values were similar to those found by others, additional patterns were identified that have not been previously observed: a marked decline in viable cells was found following turbid storm inflows and increases in the percentage of viable cells occurred during spring warming and following autumnal mixing events. Although a modest increase in abundance occurred along the gradient from inflow down-reservoir to the dam, bacterial abundance did not increase near the dam in a pattern coincident with the commonly observed increased algal biomass in the lacustrine portion of reservoir ecosystems. The increases observed in bacterial viability moving from the inflowing rivers towards the dam and later in stratified periods stress the importance of differences in environmental conditions in time and space in regulating bacterial biomass and development, as well as of shifts that would be anticipated accompanying altered hydrological regimes under climatic change.

Journal of Plankton Research↗

USGS2024

Integrating Sr isotopes, microchemistry, and genetics to reconstruct Salmonidae species and life history

Recent approaches to fisheries research emphasize the importance of the coproduction of knowledge in building resilient and culturally mindful fisheries management frameworks. Despite widespread recognition of the need for Indigenous knowledge and historical reference points as baseline data, archaeological data are rarely included in conservation biology research designs. Here we propose a novel multiproxy method to learn from former fisheries stewards by generating archaeological data on past salmonid population parameters. We used a newly developed, high throughput qPCR (HT-qPCR) chip, originally designed for environmental DNA (eDNA), for species identification of archaeological salmonid vertebrae. We combine this with the laser ablation split-stream (LASS) approach to identify ocean-migration versus freshwater residency. We test this multidisciplinary approach using both contemporary and archaeological salmonid samples and new radiocarbon dates from the Tronsdal Site on the Skagit River, Washington State, USA. This is a useful approach for extracting information about Salmonidae species and life history diversity from archaeological remains to reconstruct historic baselines for several population parameters in anadromous species with long periods of freshwater residency. The approach outlined in this paper may be particularly useful for research investigating past fisheries dynamics, offering hundreds to thousands of years of temporal depth for modern fisheries management, harvest policies, restoration ecology, and conservation biology.

Idaho, Oregon, Washington↗

USGS2021

Supporting the adaptive capacity of species through more effective knowledge exchange with conservation practitioners

There is an imperative for conservation practitioners to facilitate the ability of biodiversity to adapt to accelerating environmental change. Evolutionary biologists are well-positioned to inform the development of evidence-based management strategies that will effectively support the adaptive capacity of species and ecosystems. Conservation practitioners increasingly accept that management practices must change, but harbor concerns about how to apply recommended changes to their management contexts. Given the goodwill from both conservation practitioners and evolutionary biologists, we believe there is opportunity to accelerate the required changes by promoting closer collaboration between these two groups. We highlight how evolutionary biologists can harness lessons learned via the evidence-based conservation movement to make a substantive contribution to the development of effective conservation management practices. These lessons include: 1) recognising why practitioners do and do not use scientific evidence; 2) building an evidence base that will influence management decisions; 3) translating theory into a format that conservation practitioners can use to inform management practices; and 4) developing strategies for effective knowledge exchange. Although efforts will be required on both sides, we believe there are rewards for both practitioners and evolutionary biologists, not least of which is fostering practices that will help support the long-term persistence of species.

Evolutionary Applications↗

USGS1999

USGS international activities in coal resources

During the last 30 years the U.S. Geological Survey (USGS) has been engaged in coal exploration and characterization in more that 30 foreign countries, including India, Pakistan, China, Turkey, several Eastern European countries, Russia, and other former Soviet Union countries. Through this work, the USGS has developed an internationally recognized capability for assessing coal resources and defining their geochemical and physical characteristics. More recently, these data have been incorporated into digital databases and Geographic Information System (GIS) digital map products. The USGS has developed a high level of expertise in assessing the technological, economic, environmental, and human health impacts of coal occurrences and utilization based on comprehensive characterization of representative coal samples.

Fact Sheet↗

USGS2005

Ground-water vulnerability to nitrate contamination in the mid-atlantic region

The U.S. Environmental Protection Agency?s (USEPA) Regional Vulnerability Assessment (ReVA) Program has developed a set of statistical tools to support regional-scale, integrated ecological risk-assessment studies. One of these tools, developed by the U.S. Geological Survey (USGS), is used with available water-quality data obtained from USGS National Water-Quality Assessment (NAWQA) and other studies in association with land cover, geology, soils, and other geographic data to develop logistic-regression equations that predict the vulnerability of ground water to nitrate concentrations exceeding specified thresholds in the Mid-Atlantic Region. The models were developed and applied to produce spatial probability maps showing the likelihood of elevated concentrations of nitrate in the region. These maps can be used to identify areas that currently are at risk and help identify areas where ground water has been affected by human activities. This information can be used by regional and local water managers to protect water supplies and identify land-use planning solutions and monitoring programs in these vulnerable areas.

Fact Sheet↗

USGS2008

U.S.-Mexico Border Geographic Information System

Geographic Information Systems (GIS) and the development of extensive geodatabases have become invaluable tools for addressing a variety of contemporary societal issues and for making predictions about the future. The United States-Mexico Geographic Information System (USMX-GIS) is based on fundamental datasets that are produced and/or approved by the national geography agencies of each country, the U.S. Geological Survey (USGS) and the Instituto Nacional de Estadistica Y Geografia (INEGI) of Mexico, and the International Boundary and Water Commission (IBWC). The data are available at various scales to allow both regional and local analysis. The USGS and the INEGI have an extensive history of collaboration for transboundary mapping including exchanging digital technology and developing methods for harmonizing seamless national level geospatial datasets for binational environmental monitoring, urban growth analysis, and other scientific applications.

Fact Sheet↗

USGS2022

Detecting algal toxins and organic contaminants of concern in the environment

The U.S. Geological Survey (USGS) Kansas Water Science Center Organic Geochemistry Research Laboratory (OGRL) was established in 1987. The OGRL is a multidisciplinary program that contributes knowledge about the distribution, fate, transport, and effects of new and understudied organic compounds that may affect human health and (or) ecosystems. The OGRL consists of two units: Algal and Other Environmental Toxins Unit and Environmental Organic Chemistry Unit. The OGRL does independent and collaborative research, develops robust analytical methods, and provides fee-for-service analytical laboratory analyses.

Fact Sheet↗

USGS2007

Finding the Exotic Faucet Snail (Bithynia tentaculata): Investigation of Waterbird Die-Offs on the Upper Mississippi River National Wildlife and Fish Refuge

Beginning in 2002, there have been major waterbird die-offs every spring and fall in Lake Onalaska (Navigation Pool 7 of the Upper Mississippi River) located near La Crosse, Wisconsin. This area is part of the Upper Mississippi River National Wildlife and Fish Refuge (UMR Refuge) and lies within the Mississippi Flyway, through which an estimated 40 percent of the continent's waterfowl migrate. Through the 2006 spring migration, total mortality on the UMR Refuge was estimated at 22,000 to 26,000 birds, primarily American coots (Fulica americana) and lesser scaup (Aythya affinis). Two trematodes (Sphaeridiotrema globulus and Cyathocotyle bushiensis) that use the exotic faucet snail (Bithynia tentaculata) as an intermediate host were found to infect and kill the waterbirds. The faucet snail was introduced into the United States from Europe in the late 1800s. Because Lake Onalaska is a major spring and fall stop-over area for waterfowl in the Mississippi Flyway, concerns were raised that the snail and trematodes may be spreading to other waterfowl stop-over areas on the river. Exploratory sampling for faucet snails was conducted in 2005 and 2006 in navigation Pools 4-9 (excluding Pool 5a which is located between Pools 5 and 6), 11, and 13. Infected snails were found in all the sampled pools except Pool 6. To our knowledge, these are the first records of faucet snails and associated trematodes beyond those found in Pool 7, Lake Onalaska. Waterbird die-offs are becoming a UMR Refuge-wide problem. Information obtained through research and monitoring, including the identification of the origin of infections in snails and birds and the role various environmental factors have on this process, should help guide managers to develop effective mitigation and control measures.

Open-File Report↗

USGS2007

A GIS Analysis of Seagrass Resources and Condition Within Padre Island National Seashore, Texas

A survey of the seagrass resources of Padre Island National Seashore was conducted in fall 2002 and 2003, with additional sampling through 2006, to resolve distribution questions. Location coordinates were recorded to thousandths of minutes of latitude and longitude and converted to decimal degrees (minus decimal degrees for longitude) for import into ArcView (Environmental Systems Research Institute, Inc.). The seagrass core frequency data were developed as a theme in ArcView and overlaid on digital orthophoto quarter quadrangles of the U.S. Geological Survey to show sample depth with respect to mean sea level and frequency of occurrence of seagrass for five samples collected from every station sampled. These data were used to draw boundaries of area submerged at mean sea level and seagrass meadow in relation to the boundary of Padre Island National Seashore. Frequency of seagrass occurrence, mean plant height, shoot density, plant height multiplied by shoot density, live biomass, and dead biomass on a 1' latitude by 0.25' longitude grid were collected, and their distribution was plotted in space and according to depth. A User Guide for displaying data in ArcView is included at the end of this report. Seagrasses covered almost two-thirds of the regularly flooded part of Laguna Madre within the borders of Padre Island National Seashore. Comparisons with earlier surveys showed that substantial areas of seagrass cover had been lost in deep water between 1988 and 1998 as a result of a persistent phytoplankton bloom, and little recovery has occurred since. Maximum depth of seagrass occurrence responded to changes in water clarity. In contrast, much of the cover at shallow to intermediate depths lost at the south end of the study area between 1988 and 1998 was replaced by 2003. The seven stations with greatest plant height were located in this area of recent recolonization. Continuity of cover as measured by frequency of occurrence was high except near the edge of seagrass meadow. Decrease in this measure may be an indicator of meadow fragmentation, signaling deterioration of seagrass meadow before loss. The other measures of condition were so variable that they were insensitive indicators of impending change.

Open-File Report↗

USGS2013

Review of a model to assess stranding of juvenile salmon by ship wakes along the Lower Columbia River, Oregon and Washington

Long period wake waves from deep draft vessels have been shown to strand small fish, particularly juvenile Chinook salmon Oncorhynchus tschawytcha, in the lower Columbia River (LCR). The U.S. Army Corps of Engineers is responsible for maintaining the shipping channel in the LCR and recently conducted dredging operations to deepen the shipping channel from an authorized depth of 40 feet(ft) to an authorized depth of 43 ft (in areas where rapid shoaling was expected, dredging operations were used to increase the channel depth to 48 ft). A model was developed to estimate stranding probabilities for juvenile salmon under the 40- and 43-ft channel scenarios, to determine if channel deepening was going to affect wake stranding (Assessment of potential stranding of juvenile salmon by ship wakes along the Lower Columbia River under scenarios of ship traffic and channel depth: Report prepared for the Portland District U.S. Army Corps of Engineers, Portland, Oregon). The U.S. Army Corps of Engineers funded the U.S. Geological Survey to review this model. A total of 30 review questions were provided to guide the review process, and these questions are addressed in this report. In general, we determined that the analyses by Pearson (2011) were appropriate given the data available. We did identify two areas where additional information could have been provided: (1) a more thorough description of model diagnostics and model selection would have been useful for the reader to better understand the model framework; and (2) model uncertainty should have been explicitly described and reported in the document. Stranding probability estimates between the 40- and 43-ft channel depths were minimally different under most of the scenarios that were examined by Pearson (2011), and a discussion of the effects of uncertainty given these minimal differences would have been useful. Ultimately, however, a stochastic (or simulation) model would provide the best opportunity to illustrate uncertainty within a given set of model predictions, but such an approach would require a substantial amount of additional data collection. Several review questions focused on the accuracy and precision of the model estimates, but we were unable to address these questions because of the limited data that currently exists regarding wake stranding in the LCR. Additional field studies will be required to validate findings from Pearson (2011), if concerns regarding accuracy and precision remain a priority. Although the Pearson (2011) model provided a useful examination of stranding under pre-construction and post-construction conditions, future research will be required to better understand the effects of wake stranding on juvenile salmonids throughout the entire LCR. If additional information on wake stranding is desired in the future, the following topics may be of interest: (1) spatial examination of wake stranding throughout the entire LCR; (2) additional evaluation of juvenile salmonid behavior and population dynamics; (3) assessing and integrating predicted changes in ship development; and (4) assessing and integrating predicted changes in climate on environmental factors known to cause stranding.

Oregon;Washington↗

USGS2015

Simulation of nitrogen attenuation in a subterranean estuary, representative of the southern coast of Cape Cod, Massachusetts

A two-dimensional model was developed by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, to assess flow and chemical reaction associated with groundwater discharge through the subterranean estuary representative of coastal salt ponds of southern Cape Cod. The model simulated both the freshwater and saltwater flow systems and accounted for density-dependent flow, tidal fluctuation, and chemical reactivity among oxygen, dissolved organic carbon, nitrate, and ammonia. Not previously incorporated into one model, the interaction of these effects can now be simulated in the subterranean estuary context. An analysis of the flow system under mean-tide conditions was conducted first to provide the initial conditions for a subsequent analysis that included the effects of tidal fluctuations. Tidal fluctuations were simulated with a repeated couplet that represented a high tide-low tide sequence and alternating locations of head-dependent flux boundaries placed along the simulated seabed, above and below the levels of the respective high and low tides. Boundary conditions for chemical species included nitrate in recharge, and oxygen and organic matter (including organic nitrogen) in infiltrating solutions of head-dependent boundaries. Reaction chemistry was limited to oxidative degradation of organic matter (including remineralization of ammonia) with oxygen or nitrate as electron acceptors and nitrification of ammonia in the presence of oxygen. Simulations using the SEAWAT-2000 computer program resulted in two mixing zones-between freshwater and saltwater in a deep saltwater wedge and in an intertidal salt zone, which results from tidal fluctuation. The mixing zones are the principal locations where nitrogen attenuation reactions occurred-between organic matter in the saltwater zones of the aquifer and nitrate in the freshwater zone. In mean-tide PHT3D model simulations, 15 percent of nitrogen that is recharged was attenuated because of reaction with dissolved organic matter, a denitrification reaction that reduces nitrate to nitrogen gas. When a fluctuating tide was simulated, the amount of recharged nitrogen that was denitrified increased to 20 percent. Chemical reaction was controlled by the rate of mixing of freshwater and saltwater, which contained the reactants nitrate and dissolved organic matter, respectively, necessary for nitrogen attenuation reactions to take place. Reaction occurred in both the deep saltwater wedge and in an increased denitrification. However, mixing may also have been enhanced partly by numerical dispersion.

Massachusetts↗

USGS1978

Geotechnical properties of sediments from the Continental Shelf south of Icy Bay, northeastern Gulf of Alaska

Studies of geotechnical properties of marine sediments have recently intensified as the search for natural resources has expanded on the continental shelf. The U. S. Geological Survey has begun a detailed evaluation of geologic environmental conditions in continental shelf regions in order to facilitate safe development of continental shelf resources. Investigations of geohazards in the northeastern Gulf of Alaska (Fig. 1) began in 1974 when 6500 km of high and medium resolution seismic reflection data were collected from the eastern gulf between Yakutat and Montague Island (Carlson, Bruns and Molnia, 1975; Von Huene and others, 1975). The first extensive sediment sampling program was begun in 1975 when approximately 400 samples of continental shelf sediments were collected from the same area of the gulf (Carlson and others, 1977b). A limited number of geotechnical measurements were made from these samples and samples collected by subsequent programs, however, systematic measurement of geotechnical properties was not started until the 1977 cruise of the NOAA ship DISCOVERER. Once unstable environments or "geohazards", such as slumps and slides, are delineated, geotechnical testing is an important means of quantifying such geologic processes and consequently furthering our understanding of them. The purposes of this report are two-fold: (1) to report variations of physical properties in 1-2 meter gravity cores and (2) to recognize any variations in the areal distribution of these properties within and adjacent to an area of mass movement in the northeastern Gulf of Alaska.

Alaska↗

USGS2012

Estimation of baseline daily mean streamflows for ungaged locations on Pennsylvania streams, water years 1960-2008

Water-resource managers use daily mean streamflows to generate streamflow statistics and analyze streamflow conditions. An in-depth evaluation of flow regimes to promote instream ecological health often requires streamflow information obtainable only from a time series hydrograph. Historically, it has been difficult to estimate daily mean streamflow for an ungaged location. The U.S. Geological Survey (USGS), in cooperation with the Pennsylvania Department of Environmental Protection, Susquehanna River Basin Commission, and The Nature Conservancy, has developed the Ba seline S treamflow E stimator (BaSE) to estimate baseline streamflow at a daily time scale for ungaged streams in Pennsylvania using data collected during water years 1960–2008. Baseline streamflow is minimally altered by regulation, diversion, or mining, and other anthropogenic activities. Daily mean streamflow is estimated in BaSE using a methodology that equates streamflow as a percentile from a flow duration curve for a particular day at an ungaged location with streamflow as a percentile from the flow duration curve for the same day at a reference streamgage that is considered to be hydrologically similar to the ungaged location. An appropriate reference streamgage is selected using map correlation, in which variogram models are developed that correlate streamflow at one streamgage with streamflows at all other streamgages. The percentiles from a flow duration curve for the ungaged location are converted to streamflow through the use of regression equations. Regression equations used to predict 17 flow-duration exceedance probabilities were developed for Pennsylvania using geographic information system-derived basin characteristics. The standard error of prediction for the regression equations ranged from 11 percent to 92 percent with the mean of 31 percent. The map correlation method for estimating streamflow was tested at locations within two pilot basins, the Upper Delaware River Basin and the Lower Susquehanna River Basin, before being applied statewide. Reference streamgages within the pilot basins were used as ungaged locations for analyzing the map correlation method. Correlation using Spearman’s rho and centroid distance performed as well as, or better than, the method using the closest streamgage as a reference streamgage. Map correlation using the correlation metrics identified in the pilot basins was applied to 156 streamgages in and near Pennsylvania. BaSE uses the map correlation method and flow-duration exceedance probability regression equations to estimate baseline daily mean streamflow for an ungaged location. The output from BaSE is a Microsoft Excel® report file that summarizes the reference streamgage and ungaged location information, including basin characteristics, percent difference in basin characteristics between the two locations, any warning associated with the basin characteristics, mean and median streamflow for the ungaged location, and a daily hydrograph of streamflow for water years 1960–2008 for the ungaged location. The daily mean streamflow for the ungaged location can be exported as a text file to be used as input into other statistical software packages. BaSE estimates daily mean streamflow for baseline conditions only, and any alterations to streamflow from regulation, large water use, or substantial mining are not reflected in the estimated streamflow.

Pennsylvania↗