Boothville, LA Coastal Erosion Rate
Is the coast eroding 16.5 miles northeast of Boothville, LA?
Good news, and an honest one: USGS's data can't distinguish this stretch, 16.5 miles northeast of Boothville, LA, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
What this reading actually covers
USGS surveys the coast in transects spaced a few hundred feet apart; this page groups the nearest ones into a single ~3.5-mile reading for the stretch closest to Boothville, LA, rather than showing one arbitrary line. Segment center: 29.49, -89.20. USGS's Gulf of Mexico assessment last surveyed this stretch through 2001, computing the rate with its LRR method. Other US regions were surveyed in different years, sometimes decades apart, so this page states its own rather than implying one national vintage.
What backs this reading up
46 transects feed this segment's number; 67% of them individually measured retreat. USGS's confidence interval here is ±4.81 ft/yr. The unadjusted figure here, -1.37 ft/yr, would place it 171 of 1211 if ranked directly - but an unreliable rank isn't a useful one, which is exactly why "no significant trend" is the headline instead. Source: USGS Open-File Report 2004-1089. North Redington Beach, FL sits at national rank 1084 for growth (0.84 ft/yr), one reference point among the 1211 scored segments, 403 miles from here. 18.4 miles up the coast, Boothville, LA shows 13.68 ft/yr of eroding.
Boothville, LA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.