This will be a short post. I georeferenced an image from 1954 ordered from the USGS last semester and digitized the centerline of the Tickfaw River in ArcGIS. Comparing this route (1954) with the more recent route (2004) I do a lot of my analysis with was really interesting. I already knew about the giant cut-off that occured sometime in the 1980s or 1990s, but when I overlaid the digitized routes, it really pops visually. Also of note is the lateral migration of the river. With these two river routes established and georeferenced, it is possible to calculate lateral migration rates over a 50 year time span. I can do this manually, but coding it in Arc would be ideal. Regularly spaced data points would remove any bias I might project into my calculations unknowingly. Enough talk... here are some images.
1954 aerial imagery with the Tickfaw traced in red.
2004 aerial imagery with the Tickfaw traced in blue.
With the imagery removed and both routes visible, 50 years of laterial migration can be observed.
Future plans: automating a way to measure the distance between two points of equal latitude along each route and then plotting a frequency distribution to get a better handle on the lateral migration rates.
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