Guides

• How CoastErosionCheck Calculates a Coast's Erosion Rate — From USGS's raw transects to one segment-level rate: the grid, the averaging, and the significance test, explained.
• What "No Significant Trend" Actually Means — Most of the US coast USGS has measured shows no statistically reliable erosion or growth. Why that's real data, not a failed lookup.
• Why USGS's Coastal Surveys Are a Different Age in Every Region — Gulf data runs to 2001; California's spans 1852-2016. What that means for how current a reading actually is.
• Why Some US Coastline Is Growing, Not Eroding — Sediment builds up faster than it washes away on some stretches of coast. Real examples of accretion, and why it's rarer than erosion.