Draft prototype. This map shows how
land cover changed on Hawaiʻi Island from to , summarized by
ahupuaʻa and moku. We are sharing it to learn what is useful and what looks inaccurate, so please flag anything that seems suspicious.
How to read it
% changed is the share of an ahupuaʻa's mapped land whose land cover class in
differs from . Ahupuaʻa with less than ha of mapped land are listed but not ranked.
Main change is the most common from/to pair of classes in that ahupuaʻa.
Land cover view shows one year at a time; press Play to watch 2000 to 2020.
Change view shows only pixels that changed, colored by their new class.
Possible noise ("flicker")
Satellite land cover maps sometimes switch a pixel between Grass/Shrub and Tree Cover from year to year without any
real change on the ground. Pixels that switched back and forth two or more times are gray on the Change view. An
ahupuaʻa is marked noise? when more than half of its change is this kind of flicker.
Low flicker does not prove a change is real: a one-time mislabel would not be caught.
Things to know
Several Puna ahupuaʻa rank highest because the 2018 Kīlauea eruption covered forest and grassland with lava. That
change is real but natural.
Pixels are 30 m, so small changes (a single house, a narrow stream bank) are often missed.
2020 land cover is provisional in the source data.
Basemap imagery is from different dates than the land cover maps. The 2000 imagery covers only part of the island.
Data
Land cover: USGS LCMAP Hawaii Collection 1.0, primary land cover, 30 m, annual.
Ahupuaʻa and moku: Hawaiʻi Statewide GIS Program (OHA, DLNR SHPD). Some names in this layer may be misspelled; flag any you notice.
Streams: DAR Streams (2008), Hawaiʻi Statewide GIS Program. Solid lines are perennial, dashed are non-perennial.