Geology topics

Jason Siemion

Publications and source records attributed to Jason Siemion.

At least 19 recordsLinked to original sources

USGS2025

Leveraging high-frequency sensor data and U.S. National Water Model output to forecast turbidity in a drinking water supply basin

As high-frequency sensor networks increasingly enhance data-driven models of water quality, process-based models like the U.S. National Water Model (NWM) are generating accessible forecasts of streamflow at increasingly dense scales. There is now an opportunity to combine these products to construct actionable water quality forecasts. To that end, we couple streamflow forecasts from the NWM to a gradient-boosted decision tree algorithm (LightGBM) trained on 5+ years of high-frequency monitoring data to forecast in-stream turbidity levels in the Catskill Mountains, NY, USA. Results indicate LightGBM models are capable of relatively skillful predictions, which enable robust forecasts for 1–3 days lead times. LightGBM models offer improvements over a simplified linear model across the entire forecast horizon, and more spatially complex models are more resilient to error at shorter lead times (1–3 days). Moreover, interpretation of model features emphasizes high flows as a driver of turbidity in the region. Results suggest that interpretable, flexible, and efficient machine learning algorithms can produce capable water quality forecasts from streamflow forecasts and expand understanding of process dynamics. The use case illustrated here—to our knowledge the first NWM-based water quality forecast—underscores the potential to employ the NWM to expand national water quality forecasting capacity and can overall serve as a guide for similar efforts in basins across the country.

New York↗

USGS2023

Effects of a large flood on sediment and turbidity reduction projects in the Esopus Creek watershed, NY

On December 24-25, 2020, 7.3 to 14.6 cm of rain fell on a large snowpack in the upper Esopus Creek (UEC) watershed in the Catskill Mountains of New York. The resulting flood had an annual exceedance probability (AEP) of 4 to 20% (recurrence intervals of 25 to 5 years) in streams across the watershed, resulted in substantial geomorphic adjustments in some stream channels, and transported the highest sediment concentrations observed since stream restoration projects in the UEC began in 2012. The largest flooding occurred in the Stony Clove Creek subbasin of the UEC which contains 8 sediment and turbidity reduction projects. The UEC is the primary water source for the Ashokan Reservoir, part of New York City’s unfiltered water-supply system. A network of 16 turbidity-only and 13 suspended sediment and turbidity monitoring stations has been in operation within the UEC since October 2016. One of the primary purposes of this monitoring network is to investigate changes in suspended-sediment concentrations (SSC) and turbidity resulting from sediment and turbidity reduction projects (STRPs) implemented in tributaries to the UEC between 2012 and 2018. During the 2 to 8 years following the installation of the projects and prior to the 2020 flooding, declines in SSC and turbidity were measured at all monitoring sites although there were no flows that exceeded a 50% AEP flood. The flood of December 2020 had a 4-percent AEP at the subbasin outlet (Stony Clove Creek below Ox Clove at Chichester NY, USGS station number 01362370) and provided an opportunity to assess the effectiveness of the STRP following a large flood. An order of magnitude increase in suspended-sediment concentration per unit discharge was measured at the outlet of the Stony Clove Creek subbasin following the flood. Increased SSC persisted for 3 months throughout the range in discharge and for at least 1 year at high discharges following the flood. The concentration-discharge relation returned to near pre-flood levels at low discharges but continued to remain above pre-flood levels at high discharges for more than 1 year. Mapped bank erosion increased in all Stony Clove subbasins following the flood and increases in stream contact with clay-rich glacial till and lacustrine sediments were greater relative to increases in contact with alluvium. Large increases in sediment concentration were observed where contact with glacial lacustrine material also increased. Minor increases in sediment concentration per unit discharge were measured from stream reaches where STRP were constructed and substantially less erosion was noted within those reaches relative to non-STRP reaches, though some breaches in revetments were noted.

New York↗

USGS2022

Bed-material transport in the upper Esopus Creek watershed, Ulster and Greene Counties, New York, 2017–20

The U.S. Geological Survey, in cooperation with the Ashokan Watershed Stream Management Program, investigated the feasibility of bedload monitoring in the upper Esopus Creek watershed, Ulster and Greene Counties, New York, from 2017 to 2020. Traditional bedload samples were collected at two locations: Birch Creek at Big Indian, New York (station 013621955), and Stony Clove Creek at Jansen Road at Lanesville, New York (station 01362336), during two storms. Measured bedload-transport rates ranged from less than 1 to 37.2 short tons per day during the study period. Active and passive tracers were deployed in Stony Clove Creek at Jansen Road to measure bed-material displacement during storms. Accelerometers in the active tracers provided data on the initiation and duration of motion of bed material in the 128- to 190-millimeter size class (B-axis measurement of 175 millimeters). The active tracers were loosely placed on the streambed and were generally mobilized at streamflows of 130–375 cubic feet per second. Displacement of the passive tracers was measured five times and provided data on the variability of displacement of multiple-size classes of bed material by different streamflows. Passive-tracer data also indicated that particles larger than the opening of the Elwha sampler deployed for traditional sampling may have been in transport during sampling. Sediment-generated noise was not distinguishable from background stream noise in hydrophone recordings.

New York↗

USGS2022

Changes in stream chemistry in the east-central Adirondack region of New York State, 2010–2018

Decreased acidic deposition occurred through the 2010s, extending the long-term decrease begun in the early 1980s. The overall decline has resulted in rates of acidic deposition in the Adirondack region that are similar to those estimated for the early 1900s. This achievement increased attention on the issue of acidic deposition recovery and raised the question of how the low deposition levels of the 2010s were affecting the Adirondack region of New York State, where past acidic deposition effects were among the highest in the United States. This report presents stream resampling results of the East-Central Adirondack Stream Survey (ECASS), the Adirondack high-elevation stream sampling program, and the first five years of stream chemistry measurements in the Boreas River Long-Term Monitoring Watersheds. In addition, a regional comparison of stream chemistry between ECASS and the Western Adirondack Stream Survey (WASS) is presented. The primary objective of these stream resampling programs was to evaluate changes in stream chemistry during the 2010s to evaluate ongoing recovery of acidic deposition within the Adirondack region. Streams in the ECASS region (19,658 km 2 ) were sampled during spring snowmelt in 2011, 2017, and 2018; summer baseflow in 2010 and 2017; and late autumn in 2011 and 2017. ECASS stream sampling results for snowmelt in 2018 are also compared with WASS stream sampling results during snowmelt of the same year to provide a spatial assessment of stream chemistry for the entire Adirondack region. In addition, high-elevation streams were sampled in 2010-2011 and 2017 during spring snowmelt and summer baseflow, and three streams in the Boreas River watershed were sampled biweekly from 2014 through 2019. Streams were selected for sampling from the approximately 200 streams sampled originally in both the ECASS and WASS. The original ECASS and WASS streams were randomly selected from the populations of accessible streams within their respective regions. For the study reported here, subsets of streams were selected from the two original groups using a random stratified design based on the stream chemistry of the original ECASS and WASS. ECASS data are presented only for streams that were sampled in each of the seasonal surveys, which was 59, 48, and 61 streams for spring snowmelt, summer baseflow, and autumn surveys, respectively. WASS data are presented for 60 streams and high-elevation data are presented for 11 streams sampled during summer baseflow and 12 streams sampled during spring snowmelt. Overall, mean values of chemical measurements did not indicate large changes between 2010-2011 and 2017-2018 in the ECASS snowmelt, summer baseflow, or autumn surveys. Minimal acidification was observed in mean values measured in any of the surveys. Mean values of acid-neutralizing capacity (ANC) remained above 80 microequivalents per liter (µeq L -1 ), mean pH remained above 6.37, and inorganic monomeric aluminum (Al i ) remained below 1.0 micromoles per liter (µmol L -1 ), with the exception of the mean value of 1.2 µmol L -1 in the 2017 autumn survey. However, in the 2017 and 2018 snowmelt samplings 15% and 10% of the streams, respectively, had Al i concentrations above 1.0 µmol L 1 , the concentration above which is toxic to fish. Based on the estimated total length of headwater streams in the ECASS region of 11,494 km, the 10% of ECASS streams that experienced harmful Al i concentrations (Al i >1.0 µmol L -1 ) during the 2018 snowmelt survey equated to a total length of 1,091 km of headwater stream length in the region. During both summer baseflow and snowmelt sampling, high-elevation streams were less acidic in 2017 than in 2010-2011. However, in 2017 the mean Al i concentration during snowmelt was 2.6 µmol L -1 , a value that reflected low to moderate toxicity to brook trout. Concentrations of Al i in 9 out of the 12 streams were above 1.5 µmol L -1 , which exceeds the value which impairs fish communities. Greater dilution of calcium (Ca 2+ ) concentrations than sulfate (SO 4 2- ) concentrations during snowmelt was a contributing factor to the more acidic stream water measured during snowmelt than summer baseflow. Comparison of 2018 ECASS and WASS snowmelt chemistry under the current low levels of acidic deposition indicated that the spatial pattern of acidification effects on stream chemistry is largely driven by inherent Ca 2+ availability tied to spatial variations in geologic factors that control acid buffering more effectively in the ECASS region than the WASS region. The higher degree of acidification in the WASS region than the ECASS region is likely to extend into the future as a result of the relatively high dissolved organic carbon (DOC) concentrations in the WASS. Pronounced increasing trends in DOC and similarly pronounced decreasing trends in Ca 2+ and nitrate (NO 3 - ) were observed in the streams of all three Boreas River watersheds. These strong increasing DOC trends occurred in streams during a period with little or no indication of further chemical recovery from acidic deposition. The strong DOC trends in Durgin Brook and Balsam Brook, which are streams that are unlikely to have ever experienced more than minimal acidification, suggest the need for further investigation to expand our understanding of the mechanisms behind the increasing DOC trends.

New York↗

USGS2021

The water quality of selected streams in the Catskill and Delaware water-supply watersheds in New York, 1999–2009

From October 1, 1999, through September 30, 2009, water-quality samples were collected, and discharge was measured at 13 streamgages within the Catskill and Delaware watersheds of the New York City water supply system. The Catskill and Delaware watersheds supply about 90 percent of the water needed by 9 million customers. On average, 59 water-quality samples were collected at each station during each year of the study and analyzed for major ions and nutrients. At six stations, suspended-sediment samples were collected during 2001–09, and turbidity samples were collected during 2003–09. Surficial geology exerted a strong influence on the water quality of streams in the region. Stations in the Cannonsville Reservoir watershed, which has a high percentage of glacial till, had circumneutral stream water, whereas stations in the Neversink Reservoir watershed, which has a high percentage of sedimentary bedrock outcrops, had acidic stream water. All stations showed significant decreases in stream water sulfate concentrations during the study period; however, only the most acidic watersheds showed decreases in hydrogen-ion concentration. Two of the most acidic stations, East Branch Neversink River northeast of Denning and Rondout Creek above Red Brook at Peekamoose also had significant decreasing trends in inorganic monomeric aluminum concentrations, a form of aluminum that is toxic to some aquatic biota at concentrations greater than 0.05 milligram per liter. Three stations in the Neversink Reservoir watershed had inorganic monomeric aluminum concentrations that commonly exceeded 0.05 milligram per liter during the study period. At the West Branch Neversink River at Winnisook Lake near Frost Valley station concentrations of inorganic monomeric aluminum exceeded 0.3 milligram per liter at the beginning of the study, but never exceeded that level during the last 2 water years of the study. The East Branch Neversink River northeast of Denning and Rondout Creek above Red Brook at Peekamoose stations also showed decreases in inorganic monomeric aluminum concentrations during the study. The reduction in inorganic monomeric aluminum concentrations were the result of reductions in stream acidity. The reductions in stream acidity were driven by reductions in sulfate concentrations in precipitation in response to emission regulations included in title IV of the Clean Air Act Amendments of 1990 (42 USC §7651). Results indicated increasing trends in sodium and chloride concentrations for all stations with high road density relative to other stations included in the study, which could be a future water-quality concern in the region. The Town Brook watershed southeast of Hobart, the only study watershed that contained dairy farms, had a significant decreasing trend in total dissolved phosphorus concentration that may have been a result of agricultural best management practices implemented on farms by the Watershed Agricultural Program. The watershed with the second highest total phosphorus and total dissolved phosphorus concentrations was a completely forested, but previously agricultural, watershed (Town Brook tributary southeast of Hobart) that had not been actively farmed in about 80 years. The phosphorus concentrations at the Town Brook tributary southeast of Hobart station indicated that previously agricultural watersheds may continue to leach phosphorus to streams for many decades after farming has ceased. At six of the study watersheds, samples of suspended-sediment and turbidity were also collected. The watersheds with the highest suspended-sediment concentrations and turbidity also had the strongest relations between discharge and suspended-sediment concentrations. In general, the relations between discharge and turbidity were not as strong as the relations between discharge and suspended-sediment concentrations. Results indicated strong relations between suspended-sediment concentrations and turbidity levels at each station; however, relations were less strong in the agricultural watersheds. Suspended-sediment concentrations appeared to decrease at the Stony Clove Creek below Ox Clove at Chichester station following a stream stabilization project completed during the study period. However, we were unable to directly attribute the decrease to the stabilization project; there were many complicating variables that made a direct attribution difficult, such as a series of large storms shortly after the stabilization project was completed and differences in flow conditions before and after the project. However, the results have led to additional monitoring within the watershed specifically designed to determine the effectiveness of stream stabilization projects for reducing suspended-sediment concentrations and turbidity in the upper Esopus Creek watershed, the primary source of water to the Ashokan Reservoir. Water quality in the Catskill and Delaware watersheds is generally improving, and although sodium and chloride concentrations increased at some of the stations from 1999 to 2009, the concentrations in 2009 were still well below U.S. Environmental Protection Agency drinking water standards.

New York↗

USGS2021

Turbidity–suspended-sediment concentration regression equations for monitoring stations in the upper Esopus Creek watershed, Ulster County, New York, 2016–19

Upper Esopus Creek is the primary tributary to the Ashokan Reservoir, part of the New York City water-supply system. Elevated concentrations of suspended sediment and turbidity in the watershed of the creek are of concern for the system. Water samples were collected through a range of streamflow and turbidity at 14 monitoring sites in the upper Esopus Creek watershed for analyses of suspended-sediment concentration (SSC) and measurements of turbidity. Analyses of the samples provided data that were used to develop cross-section coefficients and turbidity-SSC regression equations for the monitoring sites for the period October 2016 through September 2019. The equations can be used to estimate SSC at a 15-minute timestep for the monitored sites. The equations can be validated for future use by the collection and analysis of additional data.

New York↗

USGS2021

The Biscuit Brook and Neversink Reservoir Watersheds: Long-term investigations of stream chemistry, soil chemistry, and aquatic ecology in the Catskill Mountains, New York, USA, 1983 to 2020

This data note describes the Biscuit Brook and Neversink Reservoir watershed Long-Term Monitoring Data that includes: 1) stream discharge, (1983 – 2020 for Biscuit Brook and 1937 – 2020 for the Neversink Reservoir watershed), 2) stream water chemistry, 1983-2020, at 4 stations, 3) fish survey data from 16 locations in the watershed 1990-2019, 4) soil chemistry data from 2 headwater sub-watersheds, 1993-2012, and 5) periodic stream water chemistry sampling data from 364 locations throughout the watershed, 1983-2020. The Neversink Reservoir watershed in the Catskill Mountains of New York, USA drains an area of 172.5 km 2 . The watershed feeds one of 6 reservoirs in New York City's West of Hudson water supply, which accounts for about 90% of the city's water supply. Biscuit Brook is a 9.63 km 2 tributary sub-watershed within the Neversink Reservoir watershed.

New York↗

USGS2021

The Buck Creek-Boreas River Adirondack Watershed Monitoring Program

The Buck Creek-Boreas River Adirondack Watershed Monitoring Program, located in the Adirondack region of New York State, United States, combines the monitoring of headwater streams, soils, and vegetation based on a watershed design. Continuous monitoring of six watersheds is linked to the sampling of more than 400 additional Adirondack streams between 2003 and 2019 for chemical analysis of 14 constituents throughout the highly valued Adirondack ecoregion that covers an area of more than 24 000 km2. Much of this landscape has a low capacity for acid buffering, but due to spatial variation in geologic features, some areas are moderately to well acid buffered. This program includes data that extends back to the early 1980s and is ongoing. The focus of the program is on the watersheds of headwater Adirondack streams. Soil, vegetation and stream data are used to better understand environmental effects on the linkages of these ecosystem components. Documentation of the long-term responses of Adirondack ecosystems to environmental disturbances such as acid rain, climate change and other unforeseen factors is the primary objective of the program.

New York↗

USGS2021

Have sustained acidic deposition decreases led to increased calcium availability in recovering watersheds of the Adirondack region of New York, USA?

Soil calcium depletion has been strongly linked to acidic deposition in eastern North America and recent studies have begun to document the recovery of soils in response to large decreases in acidic deposition. However, increased calcium availability has not yet been seen in the B horizon, where calcium depletion has been most acute, but mineral weathering is critically important for resupplying ecosystem calcium. This study provides new data in seven watersheds in the Adirondack region (New York, USA), where acidic deposition impacts on soils and surface waters have been substantial and recovery remains slow. Initial sampling in 1997–1998 and 2003–2004 was repeated in 2009–2010, 2014, 2016 and 2017. Exchangeable calcium concentrations increased by an average of 43% in the Oe horizon of three watersheds where this horizon was sampled (10.7–15.3 cmol c kg −1 ). Changes in calcium were not seen in the individual watersheds of the Oa and B horizons, but as a group, a significant increase in calcium was measured in the upper B horizon. Liming of a calcium-depleted watershed also tripled calcium concentration in the upper B horizon in 5 years. However, stream calcium in unlimed watersheds decreased over the study period. Small increases in B-horizon calcium may be underway

New York↗

USGS2021

Methods of liming to accelerate the reversal of acidic deposition effects in calcium-depleted Adirondack watersheds

Acidic deposition levels in the Adirondack region of New York State at the close of 2020 declined to values estimated for the early 20th century before the emergence of large-scale industrialization. However, chemical recovery of surface waters has lagged as a result of soil calcium (Ca) depletion, and long-term monitoring has not provided a clear indication that soil Ca availability has begun to increase. Recent computer modeling of Adirondack streams suggests that recovery goals may not be met in Ca-depleted watersheds for decades even with aggressive reductions in acidic deposition. The delayed response of soils and surface waters to reduced deposition has prompted consideration of adding Ca in the form of lime to increase the rate at which the effects of acidic deposition are being reversed through decreased pollutant emissions alone. In this regard, an experiment was conducted from 2013–2019 to evaluate the utility of liming to accelerate recovery in Adirondack stream watersheds that drain directly into Honnedaga Lake, near Forestport, NY. Results of this research were combined with relevant research results from prior liming studies to develop a methodology for the use of liming to accelerate reversal of acidic deposition effects tailored for the Adirondack region of New York State. This document presents (1) a rationale for liming in the context of the current acidic deposition regime, (2) an assessment of benefits and risks to be considered with various application methods, (3) a suggested method for selecting watersheds where liming would be most beneficial, and (4) an explanation of the primary factors that need to be addressed to successfully implement watershed liming.

New York↗

USGS2019

Response of water chemistry and young-of-year brook trout to channel and watershed liming in streams showing lagging recovery from acidic deposition

Reductions in sulfur emissions have initiated chemical recovery of surface waters impacted by acidic deposition in the Adirondack region of New York State. However, acidified streams remain common in the region, which limits recovery of brook trout ( Salvelinus fontinalis ) populations. To investigate liming as a method to accelerate recovery of brook trout, the channels of two acidified streams were limed annually from 2012 to 2015, and an entire watershed of a third acidified tributary was limed by helicopter in 2013. Stream flow, water chemistry, and density of young-of-year (YOY) brook trout were measured in limed streams, an untreated acidified stream, and a buffered reference stream. Lime additions increased pH and acid-neutralizing capacity and decreased inorganic monomeric aluminum concentrations to less than 2.0 μmol/L, the minimum concentration at which in situ brook trout mortality has been documented. However, of the two channel-limed streams, only stream T8 showed a significant response (P < 0.01) in YOY density, increasing from a mean of 0.4 fish/m2 before liming to 2.7 fish/m2 after liming. No YOY brook trout response was observed in the stream within the limed watershed. Groundwater inputs to streams were identified by relative differences in temperature and concentrations of silica and sodium. YOY brook trout densities increased only in the channel-limed stream (T8) with suitable groundwater inputs for fall spawning and a summer nursery. Results suggest that targeted liming of acidified streams with the necessary groundwater habitat could be beneficial in accelerating recovery of brook trout populations.

New York↗

USGS2018

Long-term changes in soil and stream chemistry across an acid deposition gradient in the northeastern United States

D eclines in acidic deposition across Europe and North America have led to decreases in surface water acidity and signs of chemical recovery of soils from acidification. To better understand the link between recovery of soils and surface waters, chemical trends in precipitation, soils, and streamwater were investigated in three watersheds representing a depositional gradient from high to low across the northeastern United States. Significant declines in concentrations of H + (ranging from −1.2 to −2.74 microequivalents [μeq] L −1 yr −1 ), NO 3 − (ranging from −0.6 to −0.84 μeq L −1 yr −1 ), and SO 4 2− (ranging from −0.95 to −2.13 μeq L −1 yr −1 ) were detected in precipitation in the three watersheds during the period 1999 to 2013. Soil chemistry in the A horizon of the watershed with the greatest decrease in deposition showed significant decreases in exchangeable Al and increases in exchangeable bases. Soil chemistry did not significantly improve during the study in the other watersheds, and base saturation in the Oa and upper B horizons significantly declined in the watershed with the smallest decrease in deposition. Streamwater SO 4 2− concentrations significantly declined in all three streams (ranging from −2.01 to −2.87 μeq L −1 yr −1 ) and acid neutralizing capacity increased (ranging from 1.38 to 1.60 μeq L −1 yr −1 ) in the two streams with the greatest decreases in deposition. Recovery of soils has likely been limited by decades of acid deposition that have leached base cations from soils with base-poor parent material.

Journal of Environmental Quality↗

USGS2017

The response of soil and stream chemistry to decreases in acid deposition in the Catskill Mountains, New York, USA

The Catskill Mountains have been adversely impacted by decades of acid deposition, however, since the early 1990s, levels have decreased sharply as a result of decreases in emissions of sulfur dioxide and nitrogen oxides. This study examines trends in acid deposition, stream-water chemistry, and soil chemistry in the southeastern Catskill Mountains. We measured significant reductions in acid deposition and improvement in stream-water quality in 5 streams included in this study from 1992 to 2014. The largest, most significant trends were for sulfate (SO 4 2− ) concentrations (mean trend of −2.5 μeq L −1 yr −1 ); hydrogen ion (H + ) and inorganic monomeric aluminum (Al im ) also decreased significantly (mean trends of −0.3 μeq L −1 yr −1 for H + and −0.1 μeq L −1 yr −1 for Al im for the 3 most acidic sites). Acid neutralizing capacity (ANC) increased by a mean of 0.65 μeq L −1 yr −1 for all 5 sites, which was 4 fold less than the decrease in SO 4 2− concentrations. These upward trends in ANC were limited by coincident decreases in base cations (−1.3 μeq L −1 yr −1 for calcium + magnesium). No significant trends were detected in stream-water nitrate (NO 3 − ) concentrations despite significant decreasing trends in NO 3 − wet deposition. We measured no recovery in soil chemistry which we attributed to an initially low soil buffering capacity that has been further depleted by decades of acid deposition. Tightly coupled decreasing trends in stream-water silicon (Si) (−0.2 μeq L −1 yr −1 ) and base cations suggest a decrease in the soil mineral weathering rate. We hypothesize that a decrease in the ionic strength of soil water and shallow groundwater may be the principal driver of this apparent decrease in the weathering rate. A decreasing weathering rate would help to explain the slow recovery of stream pH and ANC as well as that of soil base cations.

New York↗

USGS2016

Suspended-sediment and turbidity responses to sediment and turbidity reduction projects in the Beaver Kill, Stony Clove Creek, and Warner Creek Watersheds, New York, 2010–14

Suspended-sediment concentrations (SSCs) and turbidity were monitored within the Beaver Kill, Stony Clove Creek, and Warner Creek tributaries to the upper Esopus Creek in New York, the main source of water to the Ashokan Reservoir, from October 1, 2010, through September 30, 2014. The purpose of the monitoring was to determine the effects of suspended-sediment and turbidity reduction projects (STRPs) on SSC and turbidity in two of the three streams; no STRPs were constructed in the Beaver Kill watershed. During the study period, four STRPs were completed in the Stony Clove Creek and Warner Creek watersheds. Daily mean SSCs decreased significantly for a given streamflow after the STRPs were completed. The most substantial decreases in daily mean SSCs were measured at the highest streamflows. Background SSCs, as measured in water samples collected in upstream reference stream reaches, in all three streams in this study were less than 5 milligrams per liter during low and high streamflows. Longitudinal stream sampling identified stream reaches with failing hillslopes in contact with the stream channel as the primary sediment sources in the Beaver Kill and Stony Clove Creek watersheds.

New York↗

USGS2016

Methods of soil resampling to monitor changes in the chemical concentrations of forest soils

Recent soils research has shown that important chemical soil characteristics can change in less than a decade, often the result of broad environmental changes. Repeated sampling to monitor these changes in forest soils is a relatively new practice that is not well documented in the literature and has only recently been broadly embraced by the scientific community. The objective of this protocol is therefore to synthesize the latest information on methods of soil resampling in a format that can be used to design and implement a soil monitoring program. Successful monitoring of forest soils requires that a study unit be defined within an area of forested land that can be characterized with replicate sampling locations. A resampling interval of 5 years is recommended, but if monitoring is done to evaluate a specific environmental driver, the rate of change expected in that driver should be taken into consideration. Here, we show that the sampling of the profile can be done by horizon where boundaries can be clearly identified and horizons are sufficiently thick to remove soil without contamination from horizons above or below. Otherwise, sampling can be done by depth interval. Archiving of sample for future reanalysis is a key step in avoiding analytical bias and providing the opportunity for additional analyses as new questions arise.

Journal of Visualized Experiments↗

USGS2015

Coastal plain pond water quality and mercury contend of biota of the Long Island Central Pine Barrens and Mashomack Preserve: Effects of atmospheric deposition and human development

Pine barrens are considered an imperiled ecosystem in the northeastern U.S. The Suffolk County Pine Barrens, once the second largest in the Northeast, were substantially reduced and fragmented by development during the 20th century. The coastal plain ponds being considered in this study occur in central Suffolk County within the Long Island Central Pine Barrens region. This highly unique natural environment, embedded with forests and woodlands, resulted from its glacial origins and a land use history that predates European colonization. Included in this study was The Nature Conservancy’s Mashomack Preserve, located on Shelter Island between Peconic Bay and Gardiner’s Bay. There are no freshwater ponds in the Mashomack Preserve, but this area was included with the Central Pine Barrens investigation, because Shelter Island has a similar geologic and land-use history that has resulted in a similarly unique low-nutrient forest and woodland ecosystem with extremely coarse-textured soils.

New York↗

USGS2015

Acidic deposition along the Appalachian Trail corridor and its effects on acid-sensitive terrestrial and aquatic resources

The Appalachian National Scenic Trail (AT), a unit of the National Park Service (NPS), spans nearly 2,200 miles from Georgia to Maine, encompassing a diverse range of ecosystems. Acidic deposition (acid rain) threatens the AT’s natural resources. Acid rain is a result of sulfur (S) and nitrogen (N) compounds produced from fossil fuel combustion, motor vehicles, and agricultural practices. The AT is particularly vulnerable to S and N because it passes along ridgetops that receive higher levels of acid rain than lower valley terrain, and these ridges are often underlain by bedrock with minimal ability to buffer acidic inputs. Further, there are numerous S and N emission sources across the region. In the environment, acidic deposition can lower the pH of streams and soils which can ultimately affect fish, invertebrates, and vegetation that inhabit these areas. To address this concern, the MegaTransect Deposition Effects Study evaluated the condition and sensitivity of the AT corridor with respect to acidic deposition, and defined air pollution thresholds (critical and target loads) and recovery rates. Findings indicate that additional S emission reductions are needed to restore the AT.

Connecticut, Georgia, Maine, Maryland, Massachuset↗

USGS2014

Long-term soil monitoring at U.S. Geological Survey reference watersheds

Monitoring the environment by making repeated measurements through time is essential to evaluate and track the health of ecosystems (fig. 1). Long-term datasets produced by such monitoring are indispensable for evaluating the effectiveness of environmental legislation and for designing mitigation strategies to address environmental changes in an era when human activities are altering the environment locally and globally.

Fact Sheet↗