Mapping exposed and buried river channels using remote sensing techniques with an example from Mubra channel, The Negev, Israel

The Halutza, Agur and Shunra sand dunes are the continuation of the great northern Sinai dunes. Playa sediments from the late Quaternary are found on upper parts of river channels in the area of the dunes of the Northwest Negev and represent disorder in the drainage system caused by wandering of the dunes during other periods. This research examines the ability to use Synthetic Aperture Radar data (SAR), Ground Penetrating Radar (GPR) and other shallow geophysical methods as ground truth in combination with optical and IR data, for detection, identification and mapping of buried channels under sand and exposed channels in the Negev Height, Israel. The buried continuation of Mubra channel, under the Shunra sand dunes towards the west can be seen at a distance of 285 meters from 30:58:42N, 34:36:03E, while it can not be clearly seen in the Landsat TM image in the IR range. The SIR-C image, having several frequencies and polarizations, exhibits meaningful differences in reflectance between Mubra channel and its surroundings. The wavelengths and polarizations that improve the contrast between reflectance from the river channel and the sand are (in descending order): L(HV), L(HH) and C(HH).