Urban Honolulu, HI Coastal Erosion Rate
Shoreline change 2.8 miles south of Urban Honolulu, HI
Good news, and an honest one: USGS's data can't distinguish this stretch, 2.8 miles south of Urban Honolulu, HI, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
What "Urban Honolulu" means on this page
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 Urban Honolulu, HI, rather than showing one arbitrary line. Segment center: 21.28, -157.84. The survey behind it runs to 2007-2010, in USGS's Hawaii assessment, using the WLR 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
This reading comes from 168 individual transects averaged together, 46% of which measured erosion rather than growth. Uncertainty on this specific number: 0.26 ft/yr either side. The unadjusted figure here, 0.04 ft/yr, would place it 813 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 2011-1009. Rank 1211 nationally for growth belongs to Ocean Shores, WA, 2584 miles from this stretch, measured at 12.13 ft/yr. Urban Honolulu, HI, 1.1 miles off, is the adjacent measured stretch, reading slight erosion at 0.24 ft/yr.
Urban Honolulu, HI on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.