Version History for U.S. Geological Survey Scientific Investigations Report 2021-5094 Methods of Data Collection and Analysis for an Assessment of Karst Aquifer Systems Between Albany and Buffalo, New York By Bradley A. Sporleder, Benjamin N. Fisher, Douglas S. Keto, William M. Kappel, and James E. Reddy ----------------------------------------------------- First posted online October 18, 2021 ----------------------------------------------------- Revised and reposted July 29, 2022, as version 2.0 The report was updated to reflect that the associated data release was updated to version 2.0. Several edits made in the section "Collection of Bedrock and Water-Table Surface Elevation Data" to clarify how groundwater and bedrock elevation maps were created. Changes to the report for the version 2.0 update were written by an additional author of the U.S. Geological Survey, Laura M. DeMott. On the front cover, page i, and page 1, the report author byline was updated from: "By Bradley A. Sporleder, Benjamin N. Fisher, Douglas S. Keto, William M. Kappel, and James E. Reddy" to: "By Bradley A. Sporleder, Benjamin N. Fisher, Douglas S. Keto, William M. Kappel, James E. Reddy, and Laura M. DeMott". On page ii, the text and associated data release reference was updated from: "Associated data release: Sporleder, B.A., Fisher, B.N., Keto, D.S., Demott, L.M., and Fisher, S., 2021, Geospatial data to assess karst aquifer systems between Albany and Buffalo, New York: U.S. Geological Survey data release, https://doi.org/10.5066/P9AYMP94." to: "Associated data for this publication: Sporleder, B.A., DeMott, L.M., Fisher, B.N., Keto, D.S., and Fisher, S., 2021, Geospatial data to assess karst aquifer systems between Albany and Buffalo, New York (ver. 2.0, July 2022): U.S. Geological Survey data release, https://doi.org/10.5066/P9AYMP94.". The following edits were made on page 5 of the report in the section "Collection of Bedrock and Water-Table Surface Elevation Data": The beginning of the sentence "Data points are distributed * * *." was updated to "Depth data points are distributed * * *."; The following paragraph was deleted: "The depths to the surface of the water table were converted from feet to meters. Land-surface elevations were assigned to each of the data points in the bedrock and water-table datasets using the Add Surface Information tool in ArcGIS Pro and the land-surface elevation from the light detection and ranging (lidar) digital elevation model (DEM; New York State Geographic Information Systems (GIS) Clearinghouse, 2020). The bedrock and water-table surface elevations were then calculated by subtracting the depth to bedrock or the depth to the static water level from the elevation of the top of the well casing."; In the sentence following the deleted paragraph, "these elevations" was changed to "these depths"; A sentence was added to the end of the same paragraph: "The depth maps were then subtracted from the land surface elevation digital elevation model (DEM) from the USGS National Elevation Dataset (U.S. Geological Survey and Association of American State Geologists, 2019) to obtain the bedrock and water-table surface elevations (Raster Calculator, ArcGIS Pro)."; In the next paragraph, the sentence "Several different methods of surface interpolation were used to extrapolate bedrock and groundwater surfaces" was updated to "Several different methods of surface interpolation were used to extrapolate bedrock and groundwater depths between data points."; The sentence "The method that produced the lowest root mean square error was selected to generate each bedrock and groundwater surface within each study subarea." was updated to "The method that produced the lowest root mean square error was selected to generate the bedrock and groundwater surfaces for the entire dataset."; The beginning of the sentence "The initial depth surface was smoothed * * *." was updated to "The initial surfaces were smoothed * * *."; and A final sentence was added to the end of the section: "These smoothed groundwater and bedrock surfaces were each then subtracted from the DEM of the land surface, which was resampled to match the cell size of the groundwater and bedrock surface rasters." On page 5 in the section "Surficial Geology," the abbreviation definition "light detection and ranging (lidar)" was added to the first use of "lidar" in this section. On page 8 in the "References Cited" section, the reference to the associated data release was updated from: "Sporleder, B.A., Fisher, B.N., Keto, D.S., Demott, L.M., and Fisher, S., 2021, Geospatial data to assess karst aquifer systems between Albany and Buffalo, New York: U.S. Geological Survey data release, https://doi.org/10.5066/P9AYMP94." to: "Sporleder, B.A., DeMott, L.M., Fisher, B.N., Keto, D.S., and Fisher, S., 2021, Geospatial data to assess karst aquifer systems between Albany and Buffalo, New York (ver. 2.0, July 2022): U.S. Geological Survey data release, https://doi.org/10.5066/P9AYMP94.".