Spectral Analysis of Multispectral Landsat 7 ETM + and ASTER Data for Mapping Land Cover at Qurayah Sabkha, Northern Saudi Arabia

The Qurayyah Sabkha is located on the western coast of the Arabian Gulf in the Eastern Province of Saudi Arabia. The current study aims to determine the number of land cover endmembers that can be detected and mapped using Landsat 7 ETM + and ASTER. Furthermore, the study also aims to determine the spatial distribution of fractional abundances of these endmembers. Clastic sediments, calcite dominate sediments, gypsum, vegetation, water, and quartz sand were identified at the surface the Qurayyah Sabkha using Minimum Noise fraction (MNF), Pixel Purity Index (PPI), and n-D Visualization. Results from Matched Filtering (MF) and Linear Spectral Unmixing (LSU) methods showed good match and revealed that the spatial distributions of gypsum, clastic sediments, and quartz sand have nearly similar pattern as determined from Landsat 7 ETM + and ASTER data. These results also show good correspondence between spectra of sample and image. The present results also revealed good matching between the results obtained from MF, LSU, spectral analyses, and X-ray diffraction (XRD).