Dauphin Island, AL Coastal Erosion Rate
Is the coast eroding 10.2 miles east of Dauphin Island, AL?
10.2 miles east of Dauphin Island, AL: USGS's transects didn't pick up a trend here that beats the survey's own uncertainty. That's the majority case nationally, and for this stretch specifically it means the coast is holding, not that the data failed to find anything.
What "Dauphin Island" means on this page
This is a roughly 3.5-mile stretch of coast, not one address or parcel - USGS's own transects run every few hundred feet, but that's finer than any one property needs, so this page reports the stretch nearest Dauphin Island, AL. Centered near 30.24°N, 88.00°W. Survey years: 2001, method LRR, from USGS's Gulf of Mexico shoreline-change assessment. That's how current the data is here, real, but not a live feed, since a shoreline survey is a major undertaking, not an annual check-in.
What backs this reading up
96 transects feed this segment's number; 1% of them individually measured retreat. Uncertainty on this specific number: 1.25 ft/yr either side. Taken at face value, this segment's raw 0.89 ft/yr reading would land it 1088 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS Open-File Report 2004-1089. Rank 1196 nationally for growth belongs to Warrenton, OR, 2215 miles from this stretch, measured at 4.64 ft/yr. Dauphin Island, AL, 1.6 miles off, is the adjacent measured stretch, itself no significant trend.
Not this whole stretch, just Dauphin Island itself: the Coastal Change Hazards Portal is USGS's own live version of this data.