Geology topics

Research about Danville, Vermont

Source-linked reports with geographic coverage including Danville, Vermont.

5 recordsLinked to original sources

USGS2025

Long-term trends of streamwater chemistry in an agricultural watershed: Effects of anthropogenic and climatic factors

The chemistry of headwater streams is a key indicator of the health of riparian zones and surrounding terrestrial ecosystems. This chemistry is shaped by biogeochemical processes, including chemical weathering, and anthropogenic activities that interact with one another and are sensitive to climate. Elucidating trends in streamwater chemistry and the drivers that underpin them is essential for informing land-management decisions and anticipating water-quality issues that may affect downstream waters. In this work, we investigated the effects of anthropogenic and climatic factors on long-term variations in the chemistry of a first-order stream draining an agricultural catchment nested within the Sleepers River Research Watershed in Vermont, USA. We observed statistically significant increases in alkalinity and the concentrations of calcium and magnesium over a 31-year period for which 17 years of measurements were available. Through the application of generalized linear models, we found that the upward trends in alkalinity and calcium were associated with rising air temperatures, while a response to historical acid deposition played a minor role. We hypothesize that increased production of biogenic carbon dioxide and organic acids in soil and groundwater may lead to increases in chemical weathering rates under warmer climate conditions. This study emphasizes the important role of rising temperatures in the long-term increase in streamwater alkaline solutes, potentially overshadowing other influences like acidification recovery and agricultural practices. It also highlights the importance of comprehensive, long-term research to understand climate impacts on chemical weathering and inland water chemistry, which is critical for managing water quality and understanding regional and global carbon cycles.

Vermont↗

USGS2022

Hydrology and biogeochemistry datasets from Sleepers River Research Watershed, Danville, Vermont, USA

The Sleepers River Research Watershed (SRRW) in Danville, Vermont, USA, was established in 1957 by the U.S Department of Agriculture, Agricultural Research Service (ARS). The 111-km 2 area was selected as a representative mixed-land-use upland landscape in the northeastern USA, with the objective to study fundamental hydrological processes. The U.S. Geological Survey (USGS) currently operates SRRW and is the fourth federal agency to lead it. SRRW has hosted historic research on snowmelt modelling and streamflow generation processes, and USGS has augmented this hydrological foundation with biogeochemical cycling research. This data note describes five freely available data releases in stable repositories, extending to the late 2010s, from the indicated start date: aqueous chemistry and isotopes (1991); precipitation, water temperature, and streamflow (1991); groundwater levels (1991); ground frost depth (1983); and snow depth and water equivalent (1960). USGS research at SRRW is expected to continue, and we plan to update these releases every 1–3 years.

Vermont↗

USGS1997

Level II scour analysis for Bridge 8 (DANVTH00020008) on Town Highway 2, crossing the Morrill Brook, Danville, Vermont

This report provides the results of a detailed Level II analysis of scour potential at structure DANVTH00020008 on Town Highway 2 crossing Morrill Brook, Danville, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in North-East Vermont. The 4.74-mi 2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest with a residence on the upstream right bank. In the study area, Morrill Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 60 ft and an average channel depth of 8 ft. The predominant channel bed material is cobble with a median grain size (D 50 ) of 67.0 mm (0.220 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 9, 1995, indicated that the reach was stable. The Town Highway 2 crossing of Morrill Brook is a 59-ft-long, two-lane bridge consisting of one 57-foot steel-beam span (Vermont Agency of Transportation, written communication, March 24, 1995). The bridge is supported by vertical, concrete abutments. The channel is skewed approximately 5 degrees to the opening while the opening-skew-toroadway is 0 degrees. The scour protection measure at the site included type-2 stone fill (less than 36 inches diameter) along the base of the left abutment. There was type-1 stone fill (less than 12 inches diameter) along the base of the right abutment. There was also type-3 stone fill (less than 48 inches diameter) along both upstream banks at the location of previous bridge abutments. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for modelled flows ranged from 0.1 to 0.4 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.0 to 8.7 ft. The worst-case abutment scour occurred at the 100-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

Vermont↗

USGS1997

Level II scour analysis for Bridge 4 (DANVTH00010004) on Town Highway 1, crossing Joes Brook, Danville, Vermont

This report provides the results of a detailed Level II analysis of scour potential at structure DANVTH00010004 on Town Highway 1 crossing Joes Brook, Danville, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in northeastern Vermont. The 42.5-mi 2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture along the upstream and downstream left banks with trees and brush along the immediate banks. The upstream and downstream right banks are forested. In the study area, Joes Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 68 ft and an average bank height of 5 ft. The channel bed material ranges from gravel to bedrock with a median grain size (D 50 ) of 80.1 mm (0.263 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 22, 1995, indicated that the reach was stable. The Town Highway 1 crossing of Joes Brook is a 49-ft-long, two-lane bridge consisting of one 45-foot steel-beam span (Vermont Agency of Transportation, written communication, March 17, 1995). The opening length of the structure parallel to the bridge face is 45 ft.The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening and the computed opening-skew-to-roadway is 15 degrees. A scour hole 1.0 ft deeper than the mean thalweg depth was observed along the right abutment during the Level I assessment. The scour hole also extends upstream and downstream of the bridge, along the right side of the channel. The scour protection measures at the site include type-2 stone fill (less than 36 inches diameter) at the upstream end of the upstream left wingwall and along the entire base length of the downstream right wingwall. Type-3 stone fill (less than 48 inches diameter) is along the entire base length of the upstream right wingwall and type-5 protection (stone block wall) is along the upstream right bank. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows was computed to be zero ft. Abutment scour ranged from 11.7 to 13.0 ft along the right abutment and from 6.6 to 9.4 ft along the left abutment. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich and Hire equations (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

Vermont↗

USGS1997

Level II scour analysis for Bridge 25 (DANVTH00610025) on Town Highway 61, crossing Water Andric Brook, Danville, Vermont

This report provides the results of a detailed Level II analysis of scour potential at structure DANVTH00610025 on Town Highway 61 crossing Water Andric Brook, Danville, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the New England Upland section of the New England physiographic province in northeastern Vermont. The 9.69-mi 2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture on the downstream left bank while the upstream right bank is grass with trees along the immediate banks. The downstream right bank and upstream left bank are forested. In the study area, Water Andric Brook has a straight channel with a slope of approximately 0.007 ft/ft, an average channel top width of 45 ft and an average bank height of 4 ft. The predominant channel bed material is gravel with a median grain size (D 50 ) of 53.4 mm (0.175 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 22, 1995, indicated that the reach was stable. The Town Highway 61 crossing of Water Andric Brook is a 24-ft-long, two-lane bridge consisting of one 22-foot concrete slab span (Vermont Agency of Transportation, written communication, March 24, 1995). The opening length of the structure parallel to the bridge face is 22.9 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 5 degrees to the opening and the computed opening-skewto-roadway is 5 degrees. The VTAOT computed opening-skew-to-roadway is zero degrees. A scour hole 0.5 ft deeper than the mean thalweg depth was observed along the upstream half of the left abutment during the Level I assessment. The only scour protection measure at the site was type-2 stone fill (less than 36 inches diameter) at the upstream end of the upstream left wingwall. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. In addition, the incipient roadway-overtopping discharge is determined and analyzed as another potential worst-case scour scenario. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.7 to 1.3 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 9.1 to 12.5 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

Vermont↗