USGS ScienceSearch

Geology topics

Elijah Ramsey III

Publications and source records attributed to Elijah Ramsey III.

20 records · Page 2Linked to original sources

The measurement of mangrove characteristics in southwest Florida using spot multispectral data

An intensive in situ sampling program near Marco Island, Florida during 19–23 October 1988 collected information on mangrove type, maximum canopy height, and percent canopy closure. These data were correlated with selected vegetation index information derived from analysis of SPOT multispectral (XS) data obtained on 21 October 1988. The Normalized Difference (ND) vegetation index information was the most highly correlated index with percent canopy closure (r=0.91). Percent canopy closure information can be used as a surrogate for mangrove density which is of great value when predicting which parts of the mangrove ecosystem are at greatest risk after an oil spill occurs. Such information is very valuable when constructing oil spill Environmental Sensitivity Index (ESI) Maps for tropical regions of the world.

Florida

Remote sensing of water quality

Water property data were collected within 3 cooling water reservoirs (active to inactive, large [1,068 ha] to small [68.6 ha]. oligotrophic to eutrophic) at 31 locations. A description of the water characteristics was obtained including algal pigments, total suspended particles, dissolved and particulate organic matter, and total particle absorption spectra. Field data included generated water volume reflectance spectra and secchi depth. Specialized regression techniques were used to derive specific absorption coefficients from measured water property concentrations and total particle absorption spectra. Subsequently, using first order approximations relating water volume reflectance to water intrinsic properties, generated absorption coefficients were combined with an optimization procedure that minimized the difference between the observed and predicted water volume reflectances resulting in specific backscatter coefficient estimates.

South Carolina