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At least 1,369 records · Page 76Linked to original sources
USGS2012

Management implications of the science: Chapter 7 in A synthesis of aquatic science for management of Lakes Mead and Mohave

Lake Mead, particularly its Boulder Basin, is one of the most intensively monitored reservoirs in the United States. With its importance to societal needs and ecosystem benefits, interest in water quality and water resources of Lake Mead will remain high. A number of agencies have authorities and management interests in Lake Mead and maintain individual agency monitoring programs. These programs were enhanced on an interagency basis from 2004 to 2012 to facilitate intensive monitoring in all major basins of the lake. Recognition that increasing stressors and influences in individual basins can affect water quality throughout Lake Mead and gave rise to an even stronger effort towards the development of holistic and effective interagency approaches. In 2010, agency monitoring programs were used to develop a management plan for water-dependent resources at Lake Mead National Recreation Area (LMNRA). The Long-Term Limnological and Aquatic Resource Monitoring and Research Plan for Lakes Mead and Mohave (the Plan; National Park Service, 2010) documented key management questions to be addressed through monitoring and research, and identified interagency strategic objectives for water quality and water-dependent resources. Moreover, the Plan provides a framework for summarizing water quality and water resource information in five resource categories: water quality and limnology; fish and aquatic biota; sediments; birds; and riparian vegetation. The Plan also addresses three stressors to lake resources: contaminants, invasive species, and climate change. For each of these topics, the current (2012) state of knowledge is summarized for LMNRA (table 7-1), including key scientific questions and findings, management implications, and information needs. A more detailed discussion for each topic follows.

Circular↗
USGS1961

Synopsis of geologic and hydrologic results: Chapter A in Geological Survey research 1961

The Geological Survey is engaged in many different kinds of investigations in the fields of geology and hydrology. These investigations may be grouped into several broad, inter-related categories as follows: (a) Economic geology, including engineering geology (b) Regional geologic mapping, including detailed mapping and stratigraphic studies (c) Resource and topical studies (d) Ground-water studies (e) Surface-water studies (f) Quality-of-water studies (g) Field and laboratory research on geologic and hydrologic processes and principles. The Geological Survey also carries on investigations in its fields of competence for other Federal agencies that do not have the required specialized staffs or scientific facilities. Nearly all the Geological Survey's activities yield new data and principles of value in the development or application of the geologic and hydrologic sciences. The purpose of this report, which consists of 4 chapters, is to present as promptly as possible findings that have come to the fore during the fiscal year 1961 the 12 months ending June 30, 1961. The present volume, chapter A, is a synopsis of the highlights of recent findings of scientific and economic interest. Some of these findings have been published or placed on open file during the year; some are presented in chapters B, C, and D; still others have not been published previously. Only part of the scientific and economic results developed during the year can be presented in this synopsis. Readers who wish more complete or more detailed information should consult the bibliography of reports beginning on page A-156 of this volume, and the collection of short articles presented in the companion chapters as follows: Prof. Paper 424-B Articles 1 to 146 Prof. Paper 424-C Articles 147 to 292 Prof. Paper 424-D Articles 293 to 435 A list of investigations in progress in the Geologic and Water Resources Divisions with the names and addresses of the project leaders is given on pages A-110 to A-155 for those interested in work in progress in various areas or on special topics. During the fiscal year 1961, the services of the Geologic and Water Resources Divisions were utilized, or supported financially in part, by the many Federal and State agencies listed on pages A-106 to A-109. The Geological Survey has also cooperated from time to time with other agencies, and some of the work described in these chapters stems from work of previous years in cooperation with agencies not shown on the list. All cooperating agencies are identified where appropriate in the individual short articles in chapters B, C, and D, and they are mentioned in connection with some of the larger programs summarized in chapter A; because of space limitations, however, their contributions are mentioned in many of the short summary paragraphs contained in chapter A.

Professional Paper↗
USGS2002

Methods of analysis by the U.S. Geological Survey Organic Geochemistry Research Group: Determination of triazine and phenylurea herbicides and their degradation products in water using solid-phase extraction and liquid chromatography/mass spectrometry

An analytical method for the determination of 7 triazine and phenylurea herbicides and 12 of their degradation products in natural water samples using solid-phase extraction and liquid chromatography/mass spectrometry is presented in this report. Special consideration was given during the development of the method to prevent the formation of degradation products during the analysis. Filtered water samples were analyzed using 0.5 gram graphitized carbon as the solid-phase extraction media followed by liquid chromatography/mass spectrometry. Three different water-sample matrices ground-water, surface-water, and reagent-water samples?spiked at 0.2 and 2.0 micrograms per liter were analyzed. Method detection limits ranged from 0.013 to 0.168 microgram per liter for the parent triazine herbicides and the triazine degradation products. Method detection limits ranged from 0.042 to 0.141 microgram per liter for the parent phenylurea herbicides and their degradation products. Mean recoveries for the triazine compounds in the ground- and surface-water samples generally ranged from 72.6 to 117.5 percent, but deethyl-cyanazine amide was recovered at 140.5 percent. Mean recoveries from the ground- and surface-water samples for the phenylurea compounds spiked at the 2.0-micrograms-per-liter level ranged from 82.1 to 114.4 percent. The mean recoveries for the phenylureas spiked at 0.2-microgram per liter were less consistent, ranging from 87.0 to 136.0 percent. Mean recoveries from reagent-water samples ranged from 87.0 to 109.5 percent for all compounds. The triazine compounds and their degradation products are reported in concentrations ranging from 0.05 to 2.0 micrograms per liter, with the exception of deethylcyanazine and deethylcyanazine amide which are reported at 0.20 to 2.0 micrograms per liter. The phenylurea compounds and their degradation products are reported in concentrations ranging from 0.20 to 2.0 micrograms per liter. The upper concentration limit was 2.0 micrograms per liter for all compounds without dilution.

Open-File Report↗
USGS2020

Assessment of existing groundwater quality data in the Green-Duwamish watershed, Washington

The United States Geological Survey (USGS) provided technical support to the Washington Department of Ecology (Ecology) in their assessment of the role groundwater plays in contributing pollutant loading to the Green-Duwamish River near Seattle, Washington. Ecology is developing watershed hydrology models of the Green-Duwamish watershed, and need to assign realistic contaminant concentrations to the various Hydrologic Response Units represented in their models. The USGS compiled existing groundwater quality data in the Green-Duwamish watershed, and this report summarizes results and interpretation of the dataset, including identifying data gaps and needs for further research and monitoring. The sources of existing data were the USGS’s National Water Information System, Ecology’s Environmental Information Management System, and a compilation of several studies by Leidos, a scientific research company. The water-quality parameters of interest included polychlorinated biphenyl (PCB) Aroclors and congeners, phthalates, carcinogenic polycyclic aromatic hydrocarbons (cPAHs), arsenic, copper, and zinc. Results were grouped into the four subwatersheds delineated in Ecology’s hydrology models: Duwamish, Lower Green, Soos, and Upper Green. Results from the Duwamish subwatershed were further sub-divided by the USGS into the Lower Duwamish, containing land adjacent to the Lower Duwamish Waterway Superfund site, and the Upper Duwamish, containing the remaining area of the Duwamish subwatershed. Groundwater quality data in the Lower Duwamish were treated separately because there is known contamination in this area. The availability of water quality data varied by subwatershed as follows: phthalate data was only available within the Duwamish, PCB data was available within the Duwamish and Lower Green, cPAH data was available within the Duwamish, Lower Green, and Soos, and data for arsenic, copper, and zinc were available within all four subwatersheds. More than 99 percent of the available data was within the Duwamish subwatershed, identifying a need for additional monitoring of groundwater quality in the other subwatersheds.

Washington↗
USGS2020

Implementation of a surface water extent model in Cambodia using cloud-based remote sensing

Mapping surface water over time provides the spatially explicit information essential for hydroclimatic research focused on droughts and flooding. Hazard risk assessments and water management planning also rely on accurate, long-term measurements describing hydrologic fluctuations. Stream gages are a common measurement tool used to better understand flow and inundation dynamics, but gage networks are incomplete or non-existent in many parts of the world. In such instances, satellite imagery may provide the only data available to monitor surface water changes over time. Here, we describe an effort to extend the applicability of the USGS Dynamic Surface Water Extent (DSWE) model to non-US regions. We leverage the multi-decadal archive of the Landsat satellite in the Google Earth Engine (GEE) cloud-based computing platform to produce and analyze 372 monthly composite maps and 31 annual maps (January 1988–December 2018) in Cambodia, a flood-prone country in Southeast Asia that lacks a comprehensive stream gage network. DSWE relies on a series of spectral water indices and elevation data to classify water into four categories of water inundation. We compared model outputs to existing surface water maps and independently assessed DSWE accuracy at discrete dates across the time series. Despite considerable cloud obstruction and missing imagery across the monthly time series, the overall accuracy exceeded 85% for all annual tests. The DSWE model consistently mapped open water with high accuracy, and areas classified as “high confidence” water correlate well to other available maps at the country scale. Results in Cambodia suggest that extending DSWE globally using a cloud computing framework may benefit scientists, managers, and planners in a wide array of applications across the globe.

Remote Sensing↗
USGS2006

The influence of major dams on hydrology through the drainage network of the Sacramento River basin, California

This paper reports basinwide patterns of hydrograph alteration via statistical and graphical analysis from a network of long-term streamflow gauges located various distances downstream of major dams and confluences in the Sacramento River basin in California, USA. Streamflow data from 10 gauging stations downstream of major dams were divided into hydrologic series corresponding to the periods before and after dam construction. Pre- and post-dam flows were compared with respect to hydrograph characteristics representing frequency, magnitude and shape: annual flood peak, annual flow trough, annual flood volume, time to flood peak, flood drawdown time and interarrival time. The use of such a suite of characteristics within a statistical and graphical framework allows for generalising distinct strategies of flood control operation that can be identified without any a priori knowledge of operations rules. Dam operation is highly dependent on the ratio of reservoir capacity to annual flood volume (impounded runoff index). Dams with high values of this index generally completely cut off flood peaks thus reducing time to peak, drawdown time and annual flood volume. Those with low values conduct early and late flow releases to extend the hydrograph, increasing time to peak, drawdown time and annual flood volume. The analyses reveal minimal flood control benefits from foothill dams in the lower Sacramento River (i.e. dissipation of the down-valley flood control signal). The lower part of the basin is instead reliant on a weir and bypass system to control lowland flooding. Data from a control gauge (i.e. with no upstream dams) suggest a background signature of global climate change expressed as shortened flood hydrograph falling limbs and lengthened flood interarrival times at low exceedence probabilities. This research has implications for flood control, water resource management, aquatic and riparian ecosystems and for rehabilitation strategies involving flow alteration and/or manipulation of sediment supplies. Copyright ?? 2006 John Wiley & Sons, Ltd.

River Research and Applications↗
USGS1993

Preliminary evaluation of effects of best management practices in the Black Earth Creek, Wisconsin, priority watershed

Nonpoint-source contamination accounts for a substantial part of the water quality problems in many watersheds. The Wisconsin Nonpoint Source Water Pollution Abatement Program provides matching money for voluntary implementation of various best management practices (BMPs). The effectiveness of BMPs on a drainage-basin scale has not been adequately assessed in Wisconsin by use of data collected before and after BMP implementation. The U.S. Geological Survey, in cooperation with the Wisconsin Department of Natural Resources, monitored water quality in the Black Earth Creek watershed in southern Wisconsin from October 1984 through September 1986 (pre-BMP conditions). BMP implementation began during the summer of 1989 and is planned to continue through 1993. Data collection resumed in fall 1989 and is intended to provide information during the transitional period of BMP implementation (1990-93) and 2 years of post-BMP conditions (1994-95). Preliminary results presented for two subbasins in toe Black Earth Creek watershed (Brewery and Garfoot Creeks) are based on data collected during pre-BMP conditions and the first 3 years of the transitional period. The analysis includes the use of regressions to control for natural variability in the data and, hence, enhance the ability to detect changes. Data collected to date (1992) indicate statistically significant differences in storm mass transport of suspended sediment and ammonia nitrogen at Brewery Creek. The central tendency of the regression residuals has decreased with the implementation of BMPs; hence, the improvement in water quality in the Brewery Creek watershed is likely a result of BMP implementation. Differences in storm mass transport at Garfoot Creek were not detected, primarily because of an insufficient number of storms in the transitional period. As practice implementation continues, the additional data will be used to determine the level of management which results in significant improvements in water quality in the two watersheds. Future research will address techniques for including snowmelt runoff and early spring storms.Nonpoint-source contamination accounts for a substantial part of the water quality problems in many watersheds. The Wisconsin Nonpoint Source Water Pollution Abatement Program provides matching money for voluntary implementation of various best management practices (BMPs). The effectiveness of BMP s on a drainage-basin scale has not been adequately assessed in Wisconsin by use of data collected before and after BMP implementation. The U.S. Geological Survey, in cooperation with the Wisconsin Department of Natural Resources, monitored water quality in the Black Earth Creek watershed in southern Wisconsin from October 1984 through September 1986 (pre-BMP conditions). BMP implementation began during the summer of 1989 and is planned to continue through 1993. Data collection resumed in fall 1989 and is intended to provide information during the transitional period of BMP implementation (1990-93) and 2 years of post-BMP conditions (1994-95). Preliminary results presented for two subbasins in the Black Earth Creek watershed (Brewery and Garfoot Creeks) are based on data collected during pre-BMP conditions and the first 3 years of the transitional period. The analysis includes the use of regressions to control for natural variability in the data and, hence, enhance the ability to detect changes. Data collected to date (1992) indicate statistically significant differences in storm mass transport of suspended sediment and ammonia nitrogen at Brewery Creek. The central tendency of the regression residuals has decreased with the implementation of BMPs; hence, the improvement in water quality in the Brewery Creek watershed is likely a result of BMP implementation. Differences in storm mass transport at Garfoot Creek were not detected, primarily because of an insufficient number of storms in the transitional period. As practice implementation continues, the addit

Conference Paper↗
USGS1992

Hydrologic research at the Princeton, Minnesota management systems evaluation area

The Management Systems Evaluation Area (MSEA) program is part of a multi-scale, inter-agency initiative to evaluate the effects of agricultural management systems on water quality. The program resulted from the integration of the U.S. Department of Agriculture (USDA) Research Plan for Water Quality and the U.S Geological Survey (USGS) Mid-Continent Herbicide Initiative and is part of the President's Water Quality Initiative. The mid-continental corn belt was selected for study because it is an area where about 60% of the Nation's pesticides and nitrogen fertilizers are used.

Minnesota↗
USGS2017

High resolution water body mapping for SWAT evaporative modelling in the Upper Oconee watershed of Georgia, USA

Technological improvements in remote sensing and geographic information systems have demonstrated the abundance of artificially constructed water bodies across the landscape. Although research has shown the ubiquity of small ponds globally, and in the southeastern United States in particular, their cumulative impact in terms of evaporative alteration is less well quantified. The objectives of this study are to examine the hydrologic and evaporative importance of small artificial water bodies in the Upper Oconee watershed in the northern Georgia Piedmont, USA, by mapping their locations and modelling these small reservoirs using the Soil Water Assessment Tool. Comparative Soil Water Assessment Tool models were run with and without the inclusion of small reservoir surface area and volume. The models used meteorological inputs from 1990–2013 to represent years with drought, high precipitation, and moderate precipitation for both the calibration and evaluation periods. Statistical comparison of streamflow indicated that the calibration methodology produced results where the default model simulation without reservoirs fit observed flows more closely than the modified model with small reservoirs included (e.g., Nash–Sutcliffe efficiency of 0.72 vs. 0.64, r 2 of 0.73 vs. 0.66, and percent bias of 11.4 vs. 21.6). In addition, Penman–Monteith, Hargreaves, and Priestley–Taylor evapotranspiration equations were used to estimate actual evaporation from 2,219 small water bodies identified throughout the 1,936.8 km 2 watershed. Depending on the evaporation equation used, water bodies evaporated an average of 0.03–0.036 km 3 /year for the period 2003–2013. Using Penman–Monteith further, if the reservoirs were not considered and average actual evapotranspiration rates from the rest of the basin were applied, only 0.016 km 3 of water would have left the basin as a result of evapotranspiration. This finding suggests construction of small reservoirs increased evaporation by an average of 0.017 km 3 per year (approximately 46,500 m 3 /day). As the construction of small reservoirs continues and high resolution image data used to map these water bodies becomes increasingly available, watershed models that evolve to address the cumulative impacts of small water bodies on evaporation and other hydrologic processes will have greater potential to benefit the water resource management community.

Georgia↗
USGS1986

Water resources activities in Kentucky, 1986

The U.S. Geological Survey, Water Resources Division, conducts three major types of activities in Kentucky in order to provide hydrologic information and understanding needed for the best management of Kentucky 's and the Nation 's water resources. These activities are: (1) Data collection and dissemination; (2) Water-resources appraisals (interpretive studies); and (3) Research. Activities described in some detail following: (1) collection of surface - and groundwater data; (2) operation of stations to collect data on water quality, atmospheric deposition, and sedimentation; (3) flood investigations; (4) water use; (5) small area flood hydrology; (6) feasibility of disposal of radioactive disposal in deep crystalline rocks; (7) development of a groundwater model for the Louisville area; (8) travel times for streams in the Kentucky River Basin; (9) the impact of sinkholes and streams on groundwater flow in a carbonate aquifer system; (10) sedimentation and erosion rates at the Maxey Flats Radioactive Waste Burial site; and (11) evaluation of techniques for evaluating the cumulative impacts of mining as applied to coal fields in Kentucky. (Lantz-PTT)

Open-File Report↗
USGS1999

Oculina Bank: Sidescan sonar and sediment data from a deep-water coral reef habitat off east-central Florida

The Experimental Oculina Research Reserve (EORR) is located along the shelf edge off east-central Florida in water depths of about 60 to 100 meters. It is about 7.5 km wide and 43 km long and encompasses numerous high-relief rocky pinnacles where Oculina varicosa , a fragile deep-water coral, grows. These coral reefs have historically been the sites of prolific grouper spawning aggregations and have supported a large variety of other reef fish (Gilmore and Jones, 1992). Serious decline of the fishery in the area prompted the establishment of the EORR. The data presented in this open-file report were collected as part of a cooperative project between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program and the National Marine Fisheries Service (NMFS) of the National Oceanographic and Atmospheric Administration (NOAA). The project’s goal was to provide reconnaissance geologic maps of the Experimental Oculina Research Reserve and an unprotected control area north of the reserve to support the NMFS studies of grouper spawning aggregations. To accomplish this, we collected sidescan sonar data and sediment samples throughout both study areas and used video and observations from a manned submersible at selected sites. This report includes digital mosaics of the sidescan sonar data, tabulated sediment data, and interpretative maps of the seafloor geology. The video and submersible observations are not included in this report, but were used in the interpretation of the sidescan data.

Open-File Report↗
USGS2005

Proceedings of the Federal Interagency Sediment Monitoring Instrument and Analysis Research Workshop, September 9-11, 2003, Flagstaff, Arizona

The Advisory Committee on Water Information's Subcommittee on Sedimentation sponsored the Federal Interagency Sediment Monitoring Instrument and Analysis Research Workshop on September 9-11, 2003, at the U.S. Geological Survey Flagstaff Field Center, Arizona. The workshop brought together a diverse group representing most Federal agencies whose mission includes fluvial-sediment issues; academia; the private sector; and others with interests and expertise in fluvial-sediment monitoring ? suspended sediment, bedload, bed material, and bed topography ? and associated data-analysis techniques. The workshop emphasized technological and theoretical advances related to measurements of suspended sediment, bedload, bed material and bed topography, and data analyses. This workshop followed and expanded upon part of the 2002 Federal Interagency Workshop on Turbidity and Other Sediment Surrogates (http://water.usgs.gov/pubs/circ/2003/circ1250/), which initiated a process to provide national standards for measurement and use of turbidity and other sediment-surrogate data. This report provides a description of the salient attributes of the workshop and related information, major deliberations and findings, and principal recommendations. This information is available for evaluation by the Subcommittee on Sedimentation, which may opt to develop an action plan based on the recommendations that it endorses for consideration by the Advisory Committee on Water Information.

Circular↗
USGS2026

Sentinel-2 for chlorophyll-a water quality monitoring: A review of validation evidence and application potential

Water quality monitoring is integral to preserving the health of freshwater ecosystems, and satellite remote sensing has emerged as one monitoring method. Sentinel-2, in particular, has been valuable for water quality monitoring due to its 5-day global temporal revisit time and spatial resolution that ranges from 10 to 60 metres. Sentinel-2 can be used to measure and monitor chlorophyll-a, which historically has been used as an indicator of water quality, eutrophication and harmful algal blooms. Our goal was to review aquatic chlorophyll-a Sentinel-2 research to assess the types of validation evidence reported. Validation evidence is defined here as the set of information key to assessing algorithm performance, and include the spatial and temporal scales of satellite validation, reported in situ sampling method context information, demonstration of validation results through plots, and appropriate algorithm performance metrics. We highlight how the body of literature collectively contributes to advancing a national scale chlorophyll-a product that could support future resource management applications. Our review of 122 published studies indicated that much of the validation evidence corresponded to early stages, as defined by the NASA data maturity framework, due to a limited focus on individual lakes and limited detail on methodology for reproducibility. Prioritizing data accessibility for both in situ data and satellite workflows used in published studies; reporting methods with transparency and consistency; and using standard algorithm performance metrics could provide a consistent framework to support and enhance the utility of satellite inland water quality research. These three quality assurance mechanisms can promote effective evaluation of approaches for remote sensing of chlorophyll-a. Adopting these quality criteria could enable the integration of validation evidence from multiple studies, supporting more spatially and temporally representative products that would advance these approaches towards maturation for broader application.

International Journal of Remote Sensing↗
USGS2020

The next frontier: Making research more reproducible

Science and engineering rest on the concept of reproducibility. An important question for any study is: are the results reproducible? Can the results be recreated independently by other researchers or professionals? Research results need to be independently reproduced and validated before they are accepted as fact or theory. Across numerous fields like psychology, computer systems, and water resources there are problems to reproduce research results (Aarts et al. 2015; Collberg et al. 2014; Hutton et al. 2016; Stagge et al. 2019; Stodden et al. 2018). This editorial examines the challenges to reproduce research results and suggests community practices to overcome these challenges. Coordination is needed among the authors, journals, funders and institutions that produce, publish, and report research. Making research more reproducible will allow researchers, professionals, and students to more quickly understand and apply research in follow-on efforts and advance the field.

Journal of Water Resources Planning and Management↗
USGS2013

Incorporating probabilistic seasonal climate forecasts into river management using a risk-based framework

[1] Despite the influence of hydroclimate on river ecosystems, most efforts to date have focused on using climate information to predict streamflow for water supply. However, as water demands intensify and river systems are increasingly stressed, research is needed to explicitly integrate climate into streamflow forecasts that are relevant to river ecosystem management. To this end, we present a five step risk-based framework: (1) define risk tolerance, (2) develop a streamflow forecast model, (3) generate climate forecast ensembles, (4) estimate streamflow ensembles and associated risk, and (5) manage for climate risk. The framework is successfully demonstrated for an unregulated watershed in southwest Montana, where the combination of recent drought and water withdrawals has made it challenging to maintain flows needed for healthy fisheries. We put forth a generalized linear modeling (GLM) approach to develop a suite of tools that skillfully model decision-relevant low flow characteristics in terms of climate predictors. Probabilistic precipitation forecasts are used in conjunction with the GLMs, resulting in season-ahead prediction ensembles that provide the full risk profile. These tools are embedded in an end-to-end risk management framework that directly supports proactive fish conservation efforts. Results show that the use of forecasts can be beneficial to planning, especially in wet years, but historical precipitation forecasts are quite conservative (i.e., not very “sharp”). Synthetic forecasts show that a modest “sharpening” can strongly impact risk and improve skill. We emphasize that use in management depends on defining relevant environmental flows and risk tolerance, requiring local stakeholder involvement.

Montana↗
USGS2000

Sleepers River, Vermont: a Water, Energy, and Biogeochemical Budgets Program site

The Sleepers River Research Watershed in northeastern Vermont was established by the Agricultural Research Service (ARS) of the U.S. Department of Agriculture in 1959 and is now operated jointly by the U.S. Geological Survey (USGS) and the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL), will collaboration from several other Federal Agencies and Universities. The USGS has contributed to the understanding of hydrological processes and added a major biogeochemical cycling research component in the last 10 years of Sleepers River's 40-year history as a field laboratory. The USGS uses hydrologic measurements and chemical and isotopic tracing techniques to determine how water moves from the hillslope to the stream, and what processes cause chemical changes, such as neutralization of acid rain. Research results provide insights on how pollutants move through ecosystems, and how ecosystems may respond to climatic change.

Vermont↗