GIS Case Study

Using Mapping Technology to Decipher and Understand a Forgotten Landscape
1775 Plat OverlayThe sheer size of rural historic areas can be an impediment to its preservation because it can be so difficult (and prohibitively expensive) to survey the significant cultural and natural resources in the area one is trying to protect.. However, new advances in Geographic Information Systems (GIS) mapping tools allow for a more feasible and cost-effective approach to surveying large tracts of rural land. In order to document the historic landscape of the Ashley River corridor, large tracts of land to the south and west of Ashley River Road were surveyed using a combination of computer mapping with overlays of historic maps and targeted field surveys. 

Completed Digitized MapIn order to do this, HCF worked with local cultural resources firm, Brockington and Associates. Instead of using a more traditional archaeological survey that involves physically walking the area and testing the ground through a series of spaced, small shovel test pits, Brockington archaeologist and GIS specialist, Inna Moore proposed the creation of a GIS database. She argued that, using GIS, potential archaeological sites could be identified by overlaying historic plats and maps onto aerials and current topographic maps. Field survey could then confirm or negate their presence and integrity. Eventually, we could generate maps that would include the locations of old roads, long-lost structures and settlements, inland rice fields and canals, earthen property boundaries, phosphate mining ditches and more.

Colonoware, 7 ChimneysCounty maps, aerial photos, previously recorded archaeological sites and other known architectural features were collected along with maps ranging in date from the late 17th to the early 20th century. These were then geo-referenced with the current views and maps. This involved locating and coordinating key intersections, and landform features such as earthen boundary lines and water lines that appeared on both, and then overlaying them so that these features lined up.

Site 16 small baseA field team tested the accuracy and potential of this new method with a sample of the overlay. The team soon confirmed that this method would yield superb results. Upon reaching a location or site that appeared on historic maps, the surveyors fanned out within the immediate area to look for any visible remains of cultural or landscape features. These could include brick foundations, brick fragments, aboveground artifact scatter, as well as landscape features like canals, ditches, ornamental plantings and more. Moore took the information gleaned from the extensive survey work and generated an impressive number of maps documenting the landscape.

site 17This broad-based approach allowed us to create, for the first time, a view of the overall cultural landscape located within the forested lands across the road from the showplace plantations situated along the banks of the Ashley River. This allowed the broader history of the area to be told. 

Source: Moore, Gwendolyn. 2009. Using GIS to Reevaluate the Ashley River Historic District. Prepared by Brockington and Associates for Historic Charleston Foundation. Mt. Pleasant, SC.

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