Browsing by Subject "Erosion"

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Open Access
Determining Living Shoreline Distribution in North Carolina: A Mixed Methods Study
(2023-04-28) Lienhard, Kathryn; Fairbairn, Nicholas
Coastal landowners in North Carolina have traditionally deployed hardened structures like seawalls and bulkheads to protect coastal development from erosion and inundation. However, living shorelines have emerged in recent decades as a more ecologically integrated solution, incorporating natural and human-made components to address erosion. To date, few studies have used geospatial tools to understand the deterministic factors driving the distribution of living shorelines in North Carolina. We consider how the distribution of living shorelines varies with a community’s socioeconomic demographics, proximity to enabling institutions, and vulnerability to coastal inundation. We explore the barriers that homeowners face in acquiring a living shoreline and the perceptions that inform their decisions. Using a mixed methods approach, our study uses geospatial tools, decision-tree analysis, and semi-structured interviews with coastal landowners to distill the primary determinants governing the distribution of living shorelines across North Carolina’s coast. We find that among coastal census tracts in North Carolina, the distribution of living shorelines has a significant negative correlation with the percent of the population living in poverty, suggesting that income constrains implementation of these projects. In contrast, vulnerability to coastal inundation and proximity to enabling institutions are not predictive of living shoreline distribution. Interviews elucidate that access to information and relevant networks, capacity to navigate the installation process, and ability to pay informed many homeowners’ decisions to install a living shoreline. Taken together, our findings shed light on the need to consider equity and vulnerability in shoreline protection and coastal restoration.
Open Access
ESTIMATING THE EFFECTS OF SHORELINE CHANGE ON PROPERTY VALUES IN SANDWICH, MA USING A HEDONIC REGRESSION MODEL
(2007-05) Eberbach, Steve C.
Shoreline erosion poses a destructive threat to many densely developed coastal areas. This project uses a hedonic regression model to estimate whether or not the risks posed by shoreline change significantly influence property values in Sandwich, MA. Sandwich, MA is a historic town located on the inner reaches of Cape Cod with approximately 7.9 miles of Cape Cod Bay shoreline. Two sets of independent variables were used: 1) structural characteristics describing the physical qualities of a home, and 2) environmental characteristics measuring the risk posed to coastal properties by shoreline erosion. Results show that six of seven environmental variables are significant, including the primary variable of interest, Geotime. These results are compared to Atlantic region results published by The Heinz Center in 2000. Recommendations are made on opportunities to extend and improve the model for use in the future.
Open Access
Micro-topographic roughness analysis (MTRA) highlights minimally eroded terrain in a landscape severely impacted by historic agriculture
(Remote Sensing of Environment, 2019-03-01) Brecheisen, ZS; Cook, CW; Heine, PR; Richter, DDB
© 2018 Elsevier Inc. The 190 km2 Calhoun Critical Zone Observatory in the Piedmont region of South Carolina, USA lies in an ancient, highly weathered landscape transformed by historic agricultural erosion. Following the conversion of largely hardwood forests to cultivated fields and pastures for ~200 years, excess runoff from fields led to extreme sheet, rill, and gully erosion across the landscape. Roads, terraces, and a variety of other human disturbances have increased the landscape's surface roughness. By the 1950s, cultivation-based agriculture was largely abandoned across most of the Southern Piedmont due to soil erosion, declining agricultural productivity, and shifting agricultural markets. Secondary forests, dominated by loblolly and shortleaf pines, have since regrown on much of the landscape, including the 1500 km2 Sumter National Forest, which was purchased from farmers and private land owners in the 1930s. Although this landscape was intensively farmed for approximately 150 years, there are a few hardwood forest stands and even entire small watersheds that have never been plowed and degraded by farming. Such relatively old hardwood stands and watersheds comprise relic landforms whose soils, regoliths, and vegetation are of interest to hydrologists, environmental historians, biogeochemists, geomorphologists, geologists, pedologists, and others interested in understanding the legacy of land-use history in this severely altered environment. In this work we champion the need for high-resolution terrain mapping and demonstrate how Light Detection And Ranging (LiDAR) digital elevation model (DEM) data and microtopographic terrain roughness analyses (MTRA) can be used to infer land use history and management. This is accomplished by analyzing fine scale variation in terrain slope across the 1190 km2 CCZO using data derived from three independent and overlapping LiDAR datasets at varying spatial resolutions. Terrain slope variability MTRA is further compared to three other methods of capturing and quantifying fine-scale surface roughness. We lastly demonstrate how these analyses can be employed in concert with historic aerial photography from the 1930's, contemporary Landsat remote sensing data, and ecological field data to identify reference relic landforms: hardwood stands, hillslopes, and small watersheds that have experienced minimal anthropogenic erosion for study and conservation.