I am confused, this i started beginner in this field, how to calculate shoreline erosion and accretion in arcgis, Now i have digitized different years of shorelines. now what will do next, so experts pls give me your suggestions.
Well, what you could do is: 1. establish a series of control points along your digitised shorelines, with profile lines perpendicular to the shore at these control points. 2. Use the measure tool in ArcMap to measure the distance between each different epoch (age) shoreline along these profile lines. 3. Divide the measured distance by the time difference for each digitised shoreline. This will give you rates of shoreline change (positive for accretion, and negative for erosion) at each profile/control point location. This is, obviously, the manual way of doing things, and something that I had to do to calculate rates of change for my PhD and is, therefore, something I am very familiar with.
Another method is to use the Digital Shoreline Analysis System - available from: http://woodshole.er.usgs.gov/project-pages/dsas/ . This is a freely available shoreline analysis add-on for ArcMap, which can calculate rates of change statistics for historic shoreline data. I haven't actually used it myself, although I did get as far as downloading one of the older versions, but I would go for this first. You can always try the manual way, if you really want to, at a later date.
Dear sir, I have to reference some papers, all are say like that "the vector layers were superimposed and overlay analyses of shoreline changes for estimating the area of erosion and accretion between the period" can you please help me.
Hi, a simple Google search of your key phrases returned many results, all of which are useful. One of the search results is a paper available from academia.edu (https://www.academia.edu/3494239/Shoreline_change_rate_estimation_and_its_forecast_remote_sensing_geographical_information_system_and_statistics-based_approach). This paper goes into some detail as to how shoreline change rates are calculated and how they can be used to predict future coastal change.
The vector layers would be your digitised shorelines, each shoreline should be a different vector layer. Each layer can then be displayed separately, or superimposed on each other. If calculating an end-point rate (EPR) of coastal change, then only the oldest and most recent shoreline need be displayed and measured. Overlay analysis, would be used to calculate the area of shoreline change for a particular stretch of coast. Easiest way would be to create a polygon/series of polygons for each digitised shoreline date, with the perpendicular profile lines as the edges, an arbitrary inland line, and the front of each polygon would be the digitised shoreline. The calculated area of each polygon can then be used to calculate change in area between the epochs/date range. This would only be planimetric areal change, as there would not be any height information (no DEM) to calculate surface area or volumetric change.
You could use euclidean distance calculation in arcgis for the time interval n and extract for shore line n+1 the distances from the distance raster from shore line n.
You could use also GoogleEarth's (available) historical maps (see the upper menu bar), then save and overlay the images - directly or digitized, at the same scale and georeferenced through common reference points (i.e., a tower, a lighthouse, etc.) - using a simple graphic or CAD sw or a GIS, and measure the variations as progradation or recession of the shoreline. About the erosion/accretion (volume of sediment loss/accumulation), you need transverse-to-the coastline topografic/bathimetric profiles of different years, to overlay each other using a common reference point for the same section. Then, is possible to calculate - starting from the older year - the positive (i.e., accretion) and/or negative (i.e., erosion) volumes of sediments, using a GIS module or other CAD sw with Simpson-Cavalieri math formula.
First u have delineate all shorelines from satellite images, 2) Then, you have complete your polyline to polygon for all shorelines, 3) All completed shorelines convert " feature to polygon " , 4) Go to overlay, select " erase ", then select the polygon output feature and select one more image to erase together, remaining places we can getting, then calculate the area of erosion and accretion in attribute tables.
Jeremy Pile hi... I have a question, I already divided the measured distance by the time difference for each digitized shoreline and I got the rates of shoreline change at each control point location. The area is about 600m with 36 control points. Next, how am I going to conclude the overall changes for that area? Do I need to calculate the sum or the average distance from each point?