INTEGRATING AERIAL MAPPING AND FIELD INVESTIGATIONS OF NEW ENGLAND FIELDSTONE WALLS: A CASE STUDY FOR THREE CONTRASTING FORESTED LOCALES IN NORTHEASTERN CONNECTICUT

LiDAR mapping of New England's stone walls, even at ~1m scale, is an exercise in remote sensing and GIS analysis. Walls are either present or absent, with little differentiation. In contrast, field description and classification is based almost entirely on features invisible on aerial imagery, namely wall segmentation, structure, height, width, stone lithology, stone shape, stone placement, and degree of preservation. For example, in one suggested taxonomy, there are 18 variants and subtypes of six types of walls within the family of freestanding walls. Different geological, archaeological, and historical interpretations emerge from both ends of the spectrum from aerial imagery to field characterization. This study was designed as a pilot project to combine these approaches to enhance the interpretation of stone walls at the scale of individual farms and small villages.

We selected three contrasting, forested study areas for analysis: 1) UConn Forest, a former rough hillside pasture midway between alluvial and glaciofluvial valley bottom sediments and more productive upland soils; 2) Wormwood Hill, a low slope, heavily farmed property with portions still cleared through the 1930s and with a proximal-to-distal gradient in land use intensity away from the road/residences; and 3) Ashford Reservation, an abandoned mill village with surrounding farmland. The basic method was to map each study area using the same LiDAR techniques, and then carefully classify and describe all wall segments on the ground using the same checklist protocol.

Overall, the three study areas had commonalities and clear quantitative differences, for example in the frequency of single, double, broad, band, blocking, enclosing, and supporting walls. The abundance of stone bands (the most primitive wall structure), and broad and double walls in UConn Forest (#1) and Wormwood Hill (#2) indicate that management of waste stone was an important causal factor. In Wormwood Hill's upland setting, the systematic change in wall type and height away from the road/residence is consistent with a known chronology and intensity of use. The restriction of supporting, enclosing, and blocking, walls at Ashford Reservation (#3) is consistent with its setting as a hydropower village setting with buildings and a cemetery.