Miramar Beach, FL Coastal Erosion Rate
Is the coast eroding 1.1 miles north of Miramar Beach, FL?
1.1 miles north of Miramar Beach, FL: 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.
The grain of this number
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 Miramar Beach, FL. Centered near 30.40°N, 86.35°W. The survey behind it runs to 2001, in USGS's Gulf of Mexico assessment, using the LRR method. Shoreline surveys aren't repeated every year, so this is the most recent long-term measurement USGS has published for this coast, not a live reading.
What backs this reading up
96 transects feed this segment's number; 100% of them individually measured retreat. Uncertainty on this specific number: 0.27 ft/yr either side. Taken at face value, this segment's raw -0.17 ft/yr reading would land it 537 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS Open-File Report 2004-1089. For scale: Inverness, CA, 2143 miles away, ranks 959 of 1211 nationally for growth, 0.27 ft/yr. 3 miles away, Miramar Beach, FL is the nearest other measured stretch: also no significant trend.
Not this whole stretch, just Miramar Beach itself: the Coastal Change Hazards Portal is USGS's own live version of this data.