C-CAP Change in Estuarine Tidal Marsh Acres Per HUC12 in GCPO (1996-2010) (DRAFT)

The draft Integrated Science Agenda (ISA) of the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (GCPO) identifies Gulf Coast estuarine tidal marsh as a priority system for conservation. This map series assess change in tidal marsh using the C-CAP Land Cover Change Product (1996 - 2010). 

To facilitate the rapid assessment process we used the NOAA C-CAP Regional Land Cover Change product to assess losses and gains in estuarine emergent and scrub/shrub land cover from (1996-2010).  Though C-CAP change products are available back to 1975 in some regions of the U.S., the earliest change product available along the northern Gulf of Mexico is not until 1996.  C-CAP change products use a combination of Landsat multi-spectral scanner (MSS), thematic mapper (TM) and enhanced thematic mapper (ETM) satellite imagery, aerial photography, and plot-level data in combination with other ancillary data (e.g., digital elevation model, normalized difference vegetation index) for historic and recent eras to produce a matrix of land cover change among C-CAP classes over time.

To assess change amounts within the GCPO Gulf Coast subgeography portions of the C-CAP change product extent we first evaluated estimated losses and gains by class and overall of the C-CAP estuarine emergent and estuarine scrub/shrub classes within each GCPO state.  Losses to and gains from other classes included development, palustrine wetland, water, other estuarine wetland types, unconsolidated shore, non-wetland scrub/shrub, evergreen forest, and grassland/pasture or cultivation.  Start and end date ranges for the land cover change assessment varied by state and ranged from 1994-1997 start dates and 2009-2011 end dates.  We also clipped the C-CAP change product to a 10 km buffer east and west of the GCPO LCC boundary and assessed amount of total estuarine emergent and estuarine scrub/shrub wetland acreage lost, gained, and net change per HUC12 watershed from 1996 - 2010.

The layers presented here represent a sum of acres by HUC12 watershed lost from estuarine emergent and estuarine scrub/shrub classes, gained from other classes to estuarine emergent and estuarine scrub/shrub classes, and net change in acreage per HUC of estuarine emergent and estuarine scrub/shrub.