HR: 1340h
AN: H53G-1513    [Abstracts]
TI: Using Satellite Imagery to Predict Salinity in a Large Oligohaline Estuary
AU: * Wang, F
EM: fwang5@lsu.edu
AF: Louisiana State University Agricultural Center, School of Renewable Natural Resource, 317A RNR Bldg., Baton Rouge, LA 70803, United States
AU: Xu, Y
EM: yjxu@lsu.edu
AF: Louisiana State University Agricultural Center, School of Renewable Natural Resource, 317A RNR Bldg., Baton Rouge, LA 70803, United States
AB: Ecosystem conditions in and around estuaries are directly affected by fluctuation of their salinity changes. This study utilized satellite imagery and field measurements to develop a model for predicting salinity changes in Lake Pontchartrain, the largest estuary in the Northern Gulf of Mexico. Field salinity measurements from the lake were collected on 30 Oct. 2001, 25 Oct. 2005, and 8 May 2007. Landsat-5 TM images for these dates and additional three dates were pre-processed through "banding" noise reduction and radiometrical correction. Multivariate regression was performed to determine the relationships between measured salinity levels and water reflectance derived from TM bands 1, 2, 3, 4, 5, and 7. The regression model developed was then applied to evaluate the immediate effects of Hurricanes Katrina and Rita on saltwater intrusion into Lake Pontchartrain. The results show that the modeling achieved a high prediction power (R2 =0.83 and RMSE=0.45), with a relatively low prediction error (5.9 %). A close relationship between salinity levels and water-leaving reflectance was found (R2= 0.89), with TM bands 3 and 5 being the most important predictors. The modeled spatial pattern and magnitude of the salinity levels following Katrina and Rita show a strong, immediate effect of the hurricanes on saltwater intrusion across the lake up to the mouths of the freshwater rivers. This study demonstrates that remote sensing techniques can be a powerful tool for predicting salinity changes in large estuaries. The model, if successfully validated, should be applicable for other estuaries in the Northern Gulf of Mexico.
DE: 0480 Remote sensing
DE: 0496 Water quality
SC: Hydrology [H]
MN: 2007 Fall Meeting