Launiupoko, HI Coastal Erosion Rate
What USGS measures 0.9 miles southwest of Launiupoko, HI
The coast 0.9 miles southwest of Launiupoko, 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.
The grain of this number
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Launiupoko, HI into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 20.85°N, 156.65°W. USGS's Hawaii assessment last surveyed this stretch through 2007-2010, computing the rate with its WLR method. Other US regions were surveyed in different years, sometimes decades apart, so this page states its own rather than implying one national vintage.
How solid is this number
Averaging 345 separate transects produced this segment's rate, with 84% individually reading as erosion, rather than relying on any single survey line. The published margin on this reading runs ±0.27 ft/yr. Taken at face value, this segment's raw -0.14 ft/yr reading would land it 584 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS Open-File Report 2011-1009. Seaside, OR sits at national rank 1136 for growth (1.36 ft/yr), one reference point among the 1211 scored segments, 2533 miles from here. 2.3 miles away, Lahaina, HI is the nearest other measured stretch: also no significant trend.
Not this whole stretch, just Launiupoko itself: the Coastal Change Hazards Portal is USGS's own live version of this data.