Measuring Historical Coastal Change using GIS and the Change Polygon Approach

Abstract

This study compares two automated approaches, the transect-from-baseline technique and a new change polygon method, for quantifying historical coastal change over time. The study shows that the transect-from-baseline technique is complicated by choice of a proper baseline as well as generating transects that intersect with each other rather than with the nearest shoreline. The change polygon method captures the full spatial difference between the positions of the two shorelines and average coastal change is the defined as the ratio of the net area divided by the shoreline length. Although then change polygon method is sensitive to the definition and measurement of shoreline length, the results are more invariant to parameter changes than the transect-from-baseline method, suggesting that the change polygon technique may be a more robust coastal change method.

Automatic Extraction of Forests from Historical Maps Based on Unsupervised Classification in the CIELab Color Space

“…Capturing this spatial information interest for various studies as those one about long term changes of landscapes, urban development or coastlines evolution (Cousins 2001;Bender et al 2005;Gimmi et al 2011;Smith and Cromley 2012). For few years, a lot of these old maps are available for research thanks to the work of scanning by the national archives in different countries.…”

Spatio-Temporal Change Detection of Ningbo Coastline Using Landsat Time-Series Images during 1976–2015

“…An efficient way to create the baseline is to generate a parallel matching of the general trend of the set of shorelines. As reported in [51], the baseline based on a buffer distance of 1000 m is the most appropriate for all coastlines. Thus, the baseline in this study was built approximately 1000 m onshore using the buffering technique and editing tool of ArcGIS.…”

“…The principle of the transect-from-baseline approach is based on the assumption that the distance associated with this translation is a measurement of shoreline change if the position of a point on one shoreline shifts to a corresponding position on the other time-series shoreline [51]. The Digital Shoreline Analysis System (DSAS) [52], a free extension for ArcGIS, was utilised to measure the distance of shoreline migration through constructing transects automatically from a baseline to a set of historical shoreline data [53].…”

“…The Digital Shoreline Analysis System (DSAS) [52], a free extension for ArcGIS, was utilised to measure the distance of shoreline migration through constructing transects automatically from a baseline to a set of historical shoreline data [53]. A baseline is necessary for this operation, and this baseline must be established adjacent to the general trend of the shoreline series [51]. An efficient way to create the baseline is to generate a parallel matching of the general trend of the set of shorelines.…”

Vectorisation automatique des forêts dans les minutes de la carte d’état-major du 19esiècle

“…L'extraction de ces informations présente un intérêt pour de nombreuses études qui portent par exemple sur les transformations des paysages sur le long terme, le développement urbain, l'évolution du trait de côte, et le changement global (Cousins, 2001 ;Bender et al, 2005 ;Gimmi et al, 2011 ;Smith and Cromley, 2012).…”