Pupukea, HI Coastal Erosion Rate
Shoreline change 0.4 miles northeast of Pupukea, HI
The coast 0.4 miles northeast of Pupukea, HI shows no statistically significant trend either way. USGS's transects measured a rate here, but it's smaller than the survey's own margin of error for this stretch, so calling it "eroding" or "growing" would overstate what the data actually shows.
What "Pupukea" means on this page
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Pupukea, HI into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 21.66°N, 158.06°W. 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
Averaging 219 separate transects produced this segment's rate, with 78% individually reading as erosion, rather than relying on any single survey line. The published margin on this reading runs ±0.55 ft/yr. Taken at face value, this segment's raw -0.13 ft/yr reading would land it 604 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS Open-File Report 2011-1009. Rank 1015 nationally for growth belongs to Mexico Beach, FL, 4486 miles from this stretch, measured at 0.47 ft/yr. 2.3 miles away, Kawela Bay, HI is the nearest other measured stretch: also no significant trend.
Pupukea, HI on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.