https://spdx.org/licenses/CC0-1.0https://spdx.org/licenses/CC0-1.0
The widespread influence of land use and natural disturbance on population, community, and landscape dynamics and the long-term legacy of disturbance on modern ecosystems requires that a historical, broad-scale perspective become an integral part of modern ecological studies and conservation assessment and planning. In previous studies, the Harvard Forest Long Term Ecological Research (LTER) program has developed an integrated approach of paleoecological and historical reconstruction, meteorological modeling, air photo interpretation, GIS analyses, and field studies of vegetation and soils, to address fundamental ecological questions concerning the rates, direction, and causes of vegetation change, to evaluate controls over modern species and community distributions and landscape patterns, and to provide critical background for conservation and restoration planning. In the current study, we extend this approach to investigate the link between landscape history and the abundance, distribution, and dynamics of species, communities and landscapes of the Cape Cod to Long Island coastal region, including the islands of Martha's Vineyard, Nantucket, and Block Island. The study region includes many areas of high conservation priority that are linked geographically, historically, and ecologically. This data package includes GIS layers digitized by Harvard Forest researchers from copies of the US Coastal Survey “T-Sheet” maps available from the National Archives in College Park, Maryland. The US Coastal Survey, and then the US Coast and Geodetic Survey mapped the region, or specific parts of it, several times between 1832 and the 1960s. In this project we digitized the earliest T-Sheet available for each location. The original maps were surveyed between 1832 and 1886, with most of them made between 1835 to 1855. The original maps showed features such as roads, farm walls, railroads, buildings, some industrial buildings, saltworks, wharfs, and land cover including woodlands, sandplains, grasslands, open agricultural fields, cultivated areas, fruit tree orchards, wetlands, etc. Many sheets had symbols which differentiated conifer trees from hardwoods. There were some inconsistencies in what features were mapped or how they were drawn between the original T-Sheets. Since we digitized the maps over the course of several different research projects, we did not always digitize all of the same features in each geographic area, therefore users of this data are encouraged to look at scans of the original T-Sheets for their specific areas of interest (links below). We always digitized land cover and roads and occasionally buildings and fences as mentioned in the datasets below.
U.S. Government Workshttps://www.usa.gov/government-works
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We used a before-and-after study design to examine effects of changes in cattle grazing practices on channel stability in Muddy Creek, an arroyo in the Colorado River headwaters. The changes in grazing practices were abrupt and focused on keeping cattle out of the riparian zone and increasing herd movement. We digitized 620 meander loop cutoff geometries within the alluvial valley bottom of Muddy Creek and used the meander loop cutoff rate as a broad measure of channel stability. Poisson regression modeling of meander loop cutoff rate indicated that the change in grazing practices caused a decline in meander loop cutoff rate that was on the scale of an order of magnitude and independent of other hydroclimatic and human-caused factors. The polygon data released here was used to define the area of interest for digitizing meander loop cutoff geometries.
San Joaquin Valley Subsidence Analysis README. Written: Joel Dudas, 3/12/2017. Amended: Ben Brezing, 4/2/2019. DWR’s Division of Engineering Geodetic Branch received a request in 1/2017 from Jeanine Jones to produce a graphic of historic subsidence in the entirety of the San Joaquin Valley. The task was assigned to the Mapping & Photogrammetry Office and the Geospatial Data Support Section to complete by early February. After reviewing the alternatives, the decision was made to produce contours from the oldest available set of quad maps for which there was reasonable certainty about quality and datum, and to compare that to the most current Valley-wide DEM. For the first requirement, research indicated that the 1950’s vintage quad maps for the Valley were the best alternative. Prior quad map editions are uneven in quality and vintage, and the actual control used for the contour lines was extremely suspect. The 1950’s quads, by contrast, were produced primarily on the basis of 1948-1949 aerial photography, along with control corresponding to that period, and referenced to the National Geodetic Vertical Datum of 1929. For the current set, the most recent Valley-wide dataset that was freely available, in the public domain, and of reasonable accuracy was the 2005 NextMap SAR acquisition (referenced to NAVD88). The primary bulk of the work focused on digitizing the 1950’s contours. First, all of the necessary quads were downloaded from the online USGS quad source https://ngmdb.usgs.gov/maps/Topoview/viewer/#4/41.13/-107.51. Then the entire staff of the Mapping & Photogrammetry Lab (including both the Mapping Office and GDDS staff) proceeded to digitize the contours. Given the short turnaround time constraint and limited budget, certain shortcuts occurred in contour development. While efforts were made to digitize accurately, speed really was important. Contours were primarily focused only on agricultural and other lowland areas, and so highlands were by and large skipped. The tight details of contours along rivers, levees, and hillsides was skipped and/or simplified. In some cases, only major contours were digitized. The mapping on the source quads itself varied….in a few cases on spot elevations on benchmarks were available in quads. The contour interval sometimes varied, even within the quad sheet itself. In addition, because 8 different people were creating the contours, variability exists in the style and attention to detail. It should be understood that given the purpose of the project (display regional subsidence patterns), that literal and precise development of the historic contour sets leaves some things to be desired. These caveats being said, the linework is reasonably accurate for what it is (particularly given that the contours of that era themselves were mapped at an unknown and varying actual quality). The digitizers tagged the lines with Z values manually entered after linework that corresponded to the mapped elevation contours. Joel Dudas then did what could be called a “rough” QA/QC of the contours. The individual lines were stitched together into a single contour set, and exported to an elevation raster (using TopoToRaster in ArcGIS 10.4). Gross blunders in Z values were corrected. Gaps in the coverage were filled. The elevation grid was then adjusted to NAVD88 using a single adjustment for the entire coverage area (2.5’, which is a pretty close average of values in this region). The NextMap data was extracted for the area, and converted into feet. The two raster sets were fixed to the same origin point. The subsidence grid was then created by subtracting the old contour-derived grid from the NextMAP DEM. The subsidence grid that includes all of the values has the suffix “ALL”. Then, to improve the display fidelity, some of the extreme values (above +5’ and below -20’*) were filtered out of the dataset, and the subsidence grid was regenerated for these areas and suffixed with “cut.” The purpose of this cut was to extract some of the riverine and hilly areas that produced more extreme values and other artifacts purely due to the analysis approach (i.e. not actual real elevation change). * - some of the areas with more than 20 feet of subsidence were omitted from this clipping, because they were in heavily subsided areas and may be “real subsidence.”The resulting subsidence product should be perceived in light of the above. Some of the collar of the San Joaquin Valley shows large changes, but that is simply due to the analysis method. Also, individual grid cells may or may not be comparing the same real features. Errors are baked into both comparison datasets. However, it is important to note that the large areas of subsidence in the primary agriculture area agree fairly well with a cruder USGS subsidence map of the Valley based on extensometer data. We have confidence that the big picture story these results show us is largely correct, and that the magnitudes of subsidence are somewhat reasonable. The contour set can serve as the baseline to support future comparisons using more recent or future data as it becomes available. It should be noted there are two key versions of the data. The “Final Deliverables” from 2/2017 were delivered to support the initial Public Affairs press release. Subsequent improvements were made in coverage and blunder correction as time permitted (it should be noted this occurred in the midst of the Oroville Dam emergency) to produce the final as of 3/12/2017. Further improvements in overall quality and filtering could occur in the future if time and needs demand it. Update (4/3/2019, Ben Brezing): The raster was further smoothed to remove artifacts that result from comparing the high resolution NextMAP DEM to the lower resolution DEM that was derived from the 1950’s quad map contours. The smoothing was accomplished by removing raster cells with values that are more than 0.5 feet different than adjacent cells (25 meter cell size), as well as the adjacent cells. The resulting raster was then resampled to a raster with 100 meter cell size using cubic resampling technique and was then converted to a point feature class. The point feature class was then interpolated to a raster with 250 meter cell size using the IDW technique, a fixed search radius of 1250 meters and power=2. The resulting raster was clipped to a smaller extent to remove noisier areas around the edges of the Central Valley while retaining coverage for the main area of interest.
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The State Lands Commission has prepared the Significant Lands Inventory (report) for the California Legislature as a general identification and classification of those unconveyed State school lands and tide and submerged lands which possess significant environmental values. The publication incorporates evaluated and pertinent comments received on the initial draft report which was circulated statewide in February 1975.The absence of a particular digitized waterway in the dataset does not mean that the State does not claim ownership of that parcel or waterway, or that such specific parcel or waterway has no significant environmental values. This dataset is not intended to establish ownership, only to identify those parcels which possess significant environmental values. Staff was unable to physically inventory all of the considered lands; instead, the advice and participation of those with known environmental expertise was utilized as additional to staff survey.Tide and submerged lands are digitized in the WaterBody and WaterLine feature classes; WaterLines for coastal areas, WaterBody for inland areas. Tide and submerged lands under the jurisdiction of the State Lands Commission are those sovereign lands received from the Federal Government by virtue of California's admission to the Union on an equal footing with the original States. Such lands, and State interest therein, are generally the lands waterward of the ordinary high water mark of the Pacific Ocean (seaward to a three-mile limit); tidal bays, sloughs, estuaries; and, navigable lakes and streams within the State.School Lands are digitized in the SchoolLand feature class. State school lands under the jurisdiction of the Commission are largely composed of the 16th and 36th sections of each township. The Federal Government transferred these lands to the State in 1853, in order to establish a financial foundation for a public school system. In cases where the 16th and 36th sections were mineral in character, incomplete as to acreage total, or already claimed or granted by the Federal Government, the State was permitted to select other lands "in lieu" of the specific sections.The public trust of commerce, navigation and fisheries which the State retains on patented sovereign lands should also be considered included in this inventory. Wherever a waterway, or body of water, is listed or mapped, the common trust state interest in patented sovereign lands, if any, is also included.The State Lands Commission emphasized when it adopted this report at its December 1, 1975 meeting that all tide and submerged lands are significant by the nature of their public ownership. Only because of the methodology used for this report are all of these waterways not specifically listed in this inventory.It is the intent of the State Lands Commission that the Significant Lands Inventory be periodically updated. This dataset should be considered informational, to assist the Legislature, the Commission, and the public in considering the environmental aspects of a proposed project and the significant values to be protected therein.
The Community Interest Zone (CIZ) dataset illustrates consultation areas reserved on behalf of 21 Entitlement First Nations represented by the Treaty Land Entitlement Committee as contained within the Treaty Land Entitlement Framework Agreement signed May 29th 1997, and the Peguis Treaty Entitlement Agreement signed April 29, 2008.The CIZ boundary is based on the 1:500,000 Province of Manitoba base map and a 30-km radius drawn from a specific existing reserve boundary. The boundary of the Peguis Notice Area was included in the Peguis Treaty Entitlement Agreement and has been digitized using a heads-up digitizing method. The areas have been squared off to include the whole section where only part of a section is intersected by the 30-km radius.For more information on individual agreements please visit the Manitoba government website: https://www.gov.mb.ca/inr/settlements-and-other-agreements/index.htmlFields included [Alias (Field Name): Field description]OBJECTID (OBJECTID): Sequential unique whole numbers that are automatically generatedID Number (ID): A unique number identifying the Community Interest ZoneFirst Nation (FIRST_NATION): Name of the First Nation for whom the Community Interest Zone area is reservedCommunity Interest Zone Name (NAME): Name of Community Interest Zone area
This geodatabase includes spatial datasets that represent the Texas Coastal Uplands and Mississippi Embayment aquifer system in the States of Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas. Included are: (1) polygon extents; datasets that represent the aquifer system extent, the entire extent subdivided into subareas or subunits, and any polygon extents of special interest (outcrop areas, no data available, areas underlying other aquifers, anomalies, for example), (2) raster datasets for the altitude of each aquifer subarea or subunit, (3) altitude, and/or if applicable, thickness contours used to generate the surface rasters, (4) georeferenced images of the figures that were digitized to create the altitude and thickness contours. The images and digitized contours are supplied for reference. The extent of the Texas Coastal Uplands and Mississippi Embayment aquifer system is derived from the linework in the aquifer system extent maps in U.S. Geological Survey Professional Paper 1416-B (USGS PP 1416-B), plates 11, 13, 15, 16, and 17, and from a digital version of the aquifer extents presented in the U.S. Geological Survey Hydrologic Atlas 730, Chapters E and F. The Texas Coastal Uplands and Mississippi Embayment aquifer system has 6 aquifer subunits, in order from the most surficial to the deepest: A1: Upper Claiborne aquifer, A2: Middle Claiborne aquifer, A3: Lower Claiborne- Upper Wilcox aquifer, A4: Middle Wilcox aquifer, A5: Lower Wilcox aquifer, A6: McNairy-Nacatoch aquifer. The altitude and thickness contours for each available subunit were digitized from georeferenced figures of altitude contours in USGS PP 1416-B, and the resultant top and bottom altitude values were interpolated into surface rasters within a GIS using tools that create hydrologically correct surfaces from contour data, derives the altitude from the thickness (depth from the land surface), and merges the subareas into a single surface. The primary tool was an enhanced version of "Topo to Raster" used in ArcGIS, ArcMap, Esri 2014. The raster surfaces were corrected for the areas where the altitude of an underlying layer of the aquifer exceeded altitude of an overlying layer.
Open Government Licence - Canada 2.0https://open.canada.ca/en/open-government-licence-canada
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This polygon dataset represents Community Interest Zones (CIZ) reserved on behalf of 21 Entitlement First Nations as per the Treaty Land Entitlement Framework Agreement and the Notice Area for the Peguis Treaty Entitlement Agreement. The Community Interest Zone (CIZ) dataset illustrates consultation areas reserved on behalf of 21 Entitlement First Nations represented by the Treaty Land Entitlement Committee as contained within the Treaty Land Entitlement Framework Agreement signed May 29th 1997, and the Peguis Treaty Entitlement Agreement signed April 29, 2008. The CIZ boundary is based on the 1:500,000 Province of Manitoba base map and a 30-km radius drawn from a specific existing reserve boundary. The boundary of the Peguis Notice Area was included in the Peguis Treaty Entitlement Agreement and has been digitized using a heads-up digitizing method. The areas have been squared off to include the whole section where only part of a section is intersected by the 30-km radius. For more information on individual agreements please visit the Manitoba government website: https://www.gov.mb.ca/inr/settlements-and-other-agreements/index.html Fields included [Alias (Field Name): Field description] OBJECTID (OBJECTID): Sequential unique whole numbers that are automatically generated ID Number (ID): A unique number identifying the Community Interest Zone First Nation (FIRST_NATION): Name of the First Nation for whom the Community Interest Zone area is reserved Community Interest Zone Name (NAME): Name of Community Interest Zone area
This geodatabase contains spatial datasets that represent the Coastal Lowlands aquifer system in the States of Alabama, Florida, Louisiana, and Texas. Included are: (1) polygon extents; datasets that represent the aquifer system extent, the entire extent subdivided into subareas or subunits, and any polygon extents of special interest (outcrop areas, no data available, areas underlying other aquifers, anomalies, for example), (2) altitude, and/or if applicable, thickness contours used to generate the surface rasters, (3) raster datasets for the altitude of each aquifer subarea or subunit, (4) georeferenced images of the figures that were digitized to create the altitude or thickness contours. The images and digitized contours are supplied for reference. The extent of the Coastal Lowlands aquifer system is from the combined digitized linework of the Coastal Lowlands aquifer system extent maps in U.S. Geological Survey Professional Paper 1416-C (USGS PP 1416 C), plates 9, 10, 11, 14, and 16, figures A. Included is the "no data available" extent of Subarea 2 (see description below). The Coastal Lowlands aquifer system has 5 aquifer subunits, A = shallowest, B, C, D, E = deepest. There are two subareas. Subarea 1 is the area described in USGS PP 1416-C. Subarea 2 is the part of the aquifer in Alabama and Florida, east of the USGS PP 1416-C extent; there are no data for this subarea. The altitudes of the top surfaces of the subunits were digitized from georeferenced images of altitude contours; the altitudes of the bottom surfaces of the subunits were generated from the thickness contours of each subunit. Subunit A1 (Holocene - upper Pleistocene deposits, Permeable Zone A) Subunit A2 (lower Pleistocene - upper Pliocene deposits, Permeable Zone B) Subunit A3 (lower Pleistocene - upper Miocene deposits, Permeable Zone C) Subunit A4 (middle Miocene deposits, Permeable Zone D) Subunit A5 (lower Miocene - upper Oligocene deposits, Permeable Zone E) Digitizing of the extent and thickness/altitude linework was done by the USGS Oklahoma Water-Science Center. Subunit thickness datasets, and altitude datasets were interpolated into surface rasters within a GIS using tools that create hydrologically correct surfaces from contour data, derives the altitude from the thickness (depth from the overlying surface), and merges the subareas into a single surface. The primary tool was "Topo to Raster" used in ArcGIS, ArcMap, Esri 2014
Toronto’s Don River Valley is arguably the city’s most distinctive physical feature. As a provider of water, power, sustenance, building materials, and transportation, it has played an important role in the city’s settlement and development. The river valley has changed dramatically in the years since European settlement, particularly during the late nineteenth and early twentieth century, when the Lower Don River was straightened and channelized and the huge marsh at its mouth drained and filled. Today, the Lower Valley forms the foundation for one of the most densely populated areas in Canada, outlining as it does the eastern portion of Toronto’s downtown core and radiating residential areas. This project documents historical changes in the landscape of the Don River Valley. Drawing from the wide range of geographical information available for the Don River watershed (and the Lower Don in particular), including historical maps, geological maps, fire insurance plans, planning documents, and city directories, the project uses Geographic Information Systems software to place, compile, synthesize and interpret this information and make it more accessible as geospatial data and maps. The project is a work in progress. To date, we have scanned several dozen historical maps of Toronto and the Don River watershed, and compiled the following geospatial datasets: 1) changes to the river channel and shoreline of Toronto harbour, 1858-1918; 2) industrial development in the Lower Don River Watershed, 1857-1951 (as points, and in some cases polygons); 3) historical mill sites in the Don River Watershed, 1825; 18524) land ownership in the watershed, 1860 and 1878; and 4) points of interest in the watershed. In the future, we hope to expand the project to include data from other Toronto area watersheds and other parts of the city. The project was conducted through a collaboration between Jennifer Bonnell, a doctoral student in the History of Education program at the University of Toronto's Ontario Institute for Studies in Education (OISE/UT) - now at York University in the History Department and Marcel Fortin, the Geographic Information Systems (GIS) and Map Librarian at the University of Toronto's Map and Data Library. Financial and in-kind support was provided by the Network in Canadian History and Environment (NiCHE) and the University of Toronto Libraries. Valuable research support for the Points of Interest pages came from Lost Rivers, a community-based urban ecology organization focused on building public awareness of the City's river systems. Jordan Hale, a University of Toronto Geography student conducted much of the digitization and database work.This project could not have been completed without their skilled assistance and dedication.
This dataset contains Soil Survey Geographic Database (SSURGO) data on prime farmlands, clipped to the Mohawk River Watershed. SSURGO depicts information about the kinds and distribution of soils on the landscape. The soil map and data used in the SSURGO product were prepared by soil scientists as part of the National Cooperative Soil Survey. This data was collected by Stone Environmental, Inc. for the New York State Department of State with funds provided under Title 11 of the Environmental Protection Fund. This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The information was prepared by digitizing maps, by compiling information onto a planimetric correct base and digitizing, or by revising digitized maps using remotely sensed and other information. This data set consists of georeferenced digital map data and computerized attribute data. The map data are in a soil survey area extent format and include a detailed, field verified inventory of soils and miscellaneous areas that normally occur in a repeatable pattern on the landscape and that can be cartographically shown at the scale mapped. A special soil features layer (point and line features) is optional. This layer displays the location of features too small to delineate at the mapping scale, but they are large enough and contrasting enough to significantly influence use and management. The soil map units are linked to attributes in the National Soil Information System relational database, which gives the proportionate extent of the component soils and their properties. Mohawk River Watershed Processing: The original dataset was clipped for use in the Mohawk River Watershed Management Plan. The data was re-projected from Albers to UTM 18N, NAD 83. Attributes of interest were extracted and summarized. View Dataset on the Gateway
These data were collected by the U.S. Bureau of Land Management (BLM) in New Mexico at both the New Mexico State Office and at the various field offices. This dataset is meant to depict the federal mineral (or subsurface) interest of land parcels within New Mexico. No attempt is made to depict the mineral interest of non-federal entities. BLM's Master Title Plats are the official land records of the federal government and serve as the primary data source for depiction of federal mineral interest lands. Auxilliary source are referenced, as well, for the depiction of federal mineral interest. Collection of this dataset began in the 1980's using the BLM's ADS software to digitize information at the 1:24,000 scale. In the mid to late 1990's the data was converted from ADS to ArcInfo software and merged into tiles of one degree of longitude by one half degree of latitude. These tiles were regularly updated. The tiles were merged into a statewide coverage. The source geodatabase for this shapefile was created by loading the merged ArcInfo coverage into a personal geodatabase. The geodatabase data were snapped to a more accurate GCDB derived land network, where available. In areas where GCDB was not available the data were snapped to digitized PLSS. This shapefile has been created by exporting the geodatabase feature class.
This data was collected by the U.S. Bureau of Land Management (BLM) in New Mexico at both the New Mexico State Office and at the various field offices. This dataset is meant to depict the federal mineral (or subsurface) interest of land parcels within New Mexico. No attempt is made to depict the mineral interest of non-federal entities. BLM's Master Title Plats are the official land records of the federal government and serve as the primary data source for depiction of federal mineral interest lands. Auxilliary source are referenced, as well, for the depiction of federal mineral interest. Collection of this dataset began in the 1980's using the BLM's ADS software to digitize information at the 1:24,000 scale. In the mid to late 1990's the data was converted from ADS to ArcInfo software and merged into tiles of one degree of longitude by one half degree of latitude. These tiles were regularly updated. The tiles were merged into a statewide coverage. The source geodatabase for this shapefile was created by loading the merged ArcInfo coverage into a personal geodatabase. The geodatabase data were snapped to a more accurate GCDB derived land network, where available. In areas where GCDB was not available the data were snapped to digitized PLSS. This shapefile has been created by exporting the geodatabase feature class.
This geodatabase contains the spatial datasets that represent the Edwards-Trinity aquifer system in the States of Arkansas, Oklahoma, and Texas. Included are: (1) polygon extents; datasets that represent the aquifer system extent, the entire extent subdivided into subareas or subunits, and any polygon extents of special interest (no data available, areas underlying other aquifers, anomalies, for example), (2) raster datasets for the altitude of each aquifer subarea or subunit, (3) altitude, and/or if applicable, thickness contours used to generate the surface rasters, (4) georeferenced images of the figures that were digitized to create the altitude or thickness contours. The images and digitized contours are supplied for reference. The extent of the Edwards-Trinity aquifer system encompasses all subunits. It is delineated from the linework of the Edwards-Trinity aquifer system extent and outcrop maps of the U.S. Geological Survey Hydrologic Atlas 730-E (USGS HA 730-E) , available at http://water.usgs.gov/ogw/NatlAqCode-reflist.html. Included are the "no data available" extent polygons where there were no altitude data available for the bottom surface of the Edwards-Trinity aquifer system. These were digitized from USGS HA-730-E, figure 81, and U.S. Geological Survey Water-Resources Investigations Report 85-4116 (USGS WRIR 85-4116), plate 9, and U.S. Geological Survey Water-Resources Investigations Paper 91-4071 (USGS WRIR 91-4071), plate 1. The Edwards-Trinity aquifer system has three aquifer subunits, but for the purposes of this geodatabase only the ultimate top and bottom surface rasters are published. The altitudes for the top surface raster are from georeferenced images of altitude contours from USGS HA-730-E, figures 84, 98 and 114, and USGS WRIR 85-4116, plate 8. In the areas where the Edwards-Trinity top surface underlies the Pecos River alluvial aquifer (USGS HA 730-E, Pecos River Basin alluvial aquifer), and the High Plains aquifer (see USGS HA 730-E, High Plains aquifer), the altitude of the bottom those two aquifers is the top of the Edwards-Trinity aquifer system. The altitudes of the bottom surface raster are from georeferenced images of altitude contours from USGS HA-730-E figure 81, USGS WRIR 85-4116 plate 9, and USGS WRIR 91-4071 plate 1. The altitude contours were interpolated into surface rasters within a GIS using tools that create hydrologically correct surfaces from contour data, derives the altitude from the thickness (depth from the land surface) if necessary, and merges the subareas into a single surface. The primary tool was "Topo to Raster" used in ArcGIS, ArcMap, Esri 2014. ArcGIS Desktop: Release 10.2 Redlands, CA: Environmental Systems Research Institute.
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https://spdx.org/licenses/CC0-1.0https://spdx.org/licenses/CC0-1.0
The widespread influence of land use and natural disturbance on population, community, and landscape dynamics and the long-term legacy of disturbance on modern ecosystems requires that a historical, broad-scale perspective become an integral part of modern ecological studies and conservation assessment and planning. In previous studies, the Harvard Forest Long Term Ecological Research (LTER) program has developed an integrated approach of paleoecological and historical reconstruction, meteorological modeling, air photo interpretation, GIS analyses, and field studies of vegetation and soils, to address fundamental ecological questions concerning the rates, direction, and causes of vegetation change, to evaluate controls over modern species and community distributions and landscape patterns, and to provide critical background for conservation and restoration planning. In the current study, we extend this approach to investigate the link between landscape history and the abundance, distribution, and dynamics of species, communities and landscapes of the Cape Cod to Long Island coastal region, including the islands of Martha's Vineyard, Nantucket, and Block Island. The study region includes many areas of high conservation priority that are linked geographically, historically, and ecologically. This data package includes GIS layers digitized by Harvard Forest researchers from copies of the US Coastal Survey “T-Sheet” maps available from the National Archives in College Park, Maryland. The US Coastal Survey, and then the US Coast and Geodetic Survey mapped the region, or specific parts of it, several times between 1832 and the 1960s. In this project we digitized the earliest T-Sheet available for each location. The original maps were surveyed between 1832 and 1886, with most of them made between 1835 to 1855. The original maps showed features such as roads, farm walls, railroads, buildings, some industrial buildings, saltworks, wharfs, and land cover including woodlands, sandplains, grasslands, open agricultural fields, cultivated areas, fruit tree orchards, wetlands, etc. Many sheets had symbols which differentiated conifer trees from hardwoods. There were some inconsistencies in what features were mapped or how they were drawn between the original T-Sheets. Since we digitized the maps over the course of several different research projects, we did not always digitize all of the same features in each geographic area, therefore users of this data are encouraged to look at scans of the original T-Sheets for their specific areas of interest (links below). We always digitized land cover and roads and occasionally buildings and fences as mentioned in the datasets below.