Agricultural land use and watersheds in Hawaii
Shuhan Song
2/18/2020
Introduction
Hawaii has experienced agricultural land use change from 1980 to 2015, a shift from the plantation era in sugar and pineapple production to growing more diversified crops (State of Hawaii 2016). Agriculture, closely tied to and usually clustered around water sources, uses one-third of all water withdrawn in the US every day (US EPA 2015). In this project, I mapped agricultural land use (1976) and watersheds (2017) in Hawaii main islands (Figure 1) and provided zoomed views to subgroups of islands.
Figure 1: Hawaii main islands. Image download from mother’s niche.
Data Source
The land use/cover and watersheds data are downloaded from Hawaii Statewide GIS Program. I filtered out agricultural landcover types and renamed Horticultural Areas to represent Orchards, Groves, Vineyards, Nurseries and Ornamental Horticultural Areas.
Maps
Overall maps
Cropland and pasture dominate the agricultural land use in Hawaii in 1976 (Figure 2). Agricultural lands tend to be created near the shore where most watersheds were branched and clustered.
Figure 2: Agricultural land use and watersheds in Hawaii. Overall, most watersheds in Hawaii have area less than 5 square miles (light blue in lower map). Also, agricultural land use was significantly dominated by cropland (green in upper map) and pasture, where the former was largely used to produce sugar in 1976. Data source: Hawaii Statewide GIS Program.
Look at each island
Land use for agriculture varied among each islands.
Figure 2: Agricultural land use and watersheds in Hawaii Island. Land use is dominated by cropland and pasture. Horticultural areas also presented near cropland and pasture. Most agricultural lands clustered in the north side of the island where most watersheds were found. Data source: Hawaii Statewide GIS Program.
Figure 3: Agricultural land use and watersheds in Molokai, Maui, Kahoolawe, and Lanai Islands. Land use is dominated by cropland and pasture. Horticultural areas also presented in Maui island but was very limited in size. No land use for agriculture in Kahoolawe. Data source: Hawaii Statewide GIS Program.
Figure 4: Agricultural land use and watersheds in Oahu Islands. Land use is also dominated by cropland and pasture. The other three types of area (confined feeding operations, horticultural areas, and other agricultural land) were also presented but were very small in size. Data source: Hawaii Statewide GIS Program.
Figure 5: Agricultural land use and watersheds in Kauai and Niihau Islands. Land use in Kauai island is dominated by cropland and pasture while horticultural areas presented in both islands. Data source: Hawaii Statewide GIS Program.
Options to view it interactively
To get a even closer look at the agricultural land use, please explore the interactive maps below! Note: the colors in the maps below are different from the static maps above.