DOI: 10.5061/dryad.fn2z34tzw
title: Exponential growth of private coastal infrastructure influenced by geography and race in South Carolina, USA

description: Homeowners in coastal environments often augment their access to estuarine
 ecosystems by building private docks on their personal property. Despite
 the commonality of docks, particularly in the Southeastern United States,
 few works have investigated their historical development, their
 distribution across the landscape, or the environmental justice dimensions
 of this distribution. In this study, we used historic aerial photography
 to track the abundance and size of docks across six South Carolina
 counties from the 1950s to 2016. Across our roughly 60-year study period,
 dock abundance grew by two orders of magnitude, the mean length of newly
 constructed docks doubled, and the cumulative length of docks ballooned
 from 34 to 560 km. Additionally, we drew on census data interpolated into
 consistent 2010 tract boundaries to analyze the racial and economic
 distribution of docks in 1994, 1999, 2011, and 2016. Racial composition,
 measured as the percentage of a tract’s population that was White,
 positively correlated with dock abundance in each year. Median household
 income and dock abundance were only correlated in 2011. Taken together,
 these metrics indicate the growing desire for direct estuary access,
 however, that access does not appear to be equally spread across racial
 groups. Because docks enhance estuarine access and demarcate private
 property, our study provides longitudinal insights into environmental
 justice concerns related to disparate private property ownership. We found
 a persistent correlation between the racial characteristics of an area and
 dock abundance, strongly indicating that White South Carolinians have had
 disproportionately greater private water access for the past two decades.
description: Dock data was collected via historic aerial imagery of the South
 Carolina coast. Pre-1990 imagery was obtained from the University of South
 Carolina library, 1994 and 1999 imagery was obtained from the South
 Carolina Department of Natural Resources, and 2011 imagery was obtained
 from the US Department of Agriculture National Agriculture Imagery
 Program’s Geospatial Data Gateway
 (https://nrcs.app.box.com/v/gateway/folder/19350726983). Census data was
 obtained from the NHGIS and Historical Housing Unit and Urbanization
 Database at the tract level using their crosswalk files to interpolate
 1990 and 2000 data to 2010 tract geographies. Docks
 were tracked across decades in ArcGIS Pro and statistical models were run
 using R. Greater methodological detail is provided in the "Historic
 Infrastructure Methodology" file in the
 "Historic_Dock_Supplemental" folder on Zenodo. All pre-1990
 images therein are reproduced with permission of the University of South
 Carolina library.
description: R, ArcGIS Pro Version 2.9 or greater.
description: # Exponential growth of private coastal infrastructure influenced by
 geography and race in South Carolina, USA --- This data set contains
 ArcGIS Pro files and a CSV of every structure identified in the study. The
 code used to run the models can be found on the associated Zenodo page in
 the "Historic_Dock_Code" folder. Additional methodological
 information and model diagnostics can be found in the
 "Historic_Dock_Supplemental" folder on the associated Zenodo
 page. If you have any questions or requests please email Jeffrey Beauvais
 (he/him) at [beauvais.work@gmail.com](mailto:beauvais.work@gmail.c) ##
 Description of the Data and file structure ### Parent folder:
 Historic\_Dock\_ArcPro\_Files Contains a geodatabase (.gdb file) with
 final point layers used in the analysis for dock counts, lengths, and
 geographic boundaries. Intermediate files were redundant and excluded but
 available upon request. Some folders within are empty and automatically
 generated by ArcGIS Pro when loading the program. These are necessary for
 loading the ArcGIS Pro files. The functional files used to generate the
 raw data are located in the "Histortic_Dock_ArcPro_Files.gdb"
 (.gdb = geodatabase file), which can only be loaded within ArcGIS Pro: *
 "Boundaries_OriginalNHGIS_Tracts2010_UTM": Contains 2010 tract
 boundaries. Only contains tracts in the 6 study counties. *
 "WAI_DockCount_2011_Final_GCS": Contains only the base
 ("B") points of docks used in the analysis of dock counts. The
 attribute table contains the following columns: * OBJECTID &
 OBJECTID_1: ID value automatically generated by ArcGIS Pro (unused). *
 Shape: Automatically generated by ArcGIS Pro to designate the type of
 shape present (all values are "Point"). * Unique ID: As it
 sounds, a unique identifier given to each dock. Concatenation of the
 County, Structure_ID, and Point_Position columns. * County: The South
 Carolina county the structure was located in. * Structurte_ID: Unique
 number assigned to each structure. * Structure_Type: The kind of coastal
 infrastructure listed. * Point_Position: The location of the point placed
 on the structure. Entries are all "B" (base, where the structure
 connects to land). * GISJOIN: The census tract the point is located in.
 Used to summarize dock information at the tract level. * Notes: Reference
 notes for the structure. * Year_Added: The year of imagery the structure
 was first identified in. * Year_Defunct: The year of imagery a structure
 was noted to have disappeared. * Decade_Added: As with year added, but the
 entry reports the corresponding census decade used the analysis. *
 Decade_Defunct: As with year defunct, but the entry reports the
 corresponding census decade used the analysis. * Length: The length of the
 structure (meters) * X_B & X_E: The longitude of the base (X_B) and
 end (X_E) point (NAD 1983 geographic coordinate system). Used in tandem
 with Y_B & Y_E to calculate the length of the structure. * Y_B &
 Y_E: The latitutde of the base (Y_B) and end (Y_E) point (NAD 1983
 geographic coordinate system). Used in tandem with X_B & X_E to
 calculate the length of the structure. *
 "WAI_DockLength_2011_Final_GCS": Contains on the base
 ("B") points of docks used in the analysis of dock lengths.
 Contains a different number of docks than those used in the count analysis
 because some docks underwent changes in their length during the study
 period (e.g., storm damage or extensions). Contains the same columns in
 the attribute table above. ### Loose files: *
 "Dock_Points_2011_8-9-2022.csv": File containing every structure
 identified in the study. Contains the following columns: * UniqueID: As it
 sounds, a unique identifier given to each dock. Concatenation of the
 County, Structure_ID, and Point_Position columns. * County: The South
 Carolina county the structure was located in. * Structure_ID: Unique
 number assigned to each structure. * Structure_Type: The kind of coastal
 infrastructure listed. * Point_Position: The location of the point placed
 on the structure. Entries are either a "B" (base, where the
 structure connects to land) or an "E" (end). * Notes: Reference
 notes for the structure. * Year_Added: The year of imagery the structure
 was first identified in. * Year_Defunct: The year of imagery a structure
 was noted to have disappeared. * X: The longitude of the point (NAD 1983
 geographic coordinate system). * Y: The latitutde of the point (NAD 1983
 geographic coordinate system). * OBJECTID: ID value automatically
 generated by ArcGIS Pro (unused). ## Sharing/access Information All data
 contained therein are publishable under CC0 license. Additional pre-1990
 aerial photography is owned by the University of South Carolina library.
 Those wishing to view these original images need to contact Bill Sudduth
 ([sudduthw@mailbox.sc.edu](mailto:sudduthw@mailbox.sc.edu)) with a
 request.