The use of remote sensing and spectroscopy to identify precipitation in volcanic sand targets: A case study of Limassol, Cyprus

Abstract

The lack of available precipitation data in certain areas can be problematic, especially if the area is used as a calibration target. The study was conducted to identify differences between wet and dry sand and to apply the methodology for verifying precipitation from archived satellite images, where rainfall data do not exist. A study area was selected near Limassol Cyprus, consisting of a 250×250 meter area of volcanic beach sand. In-situ spectroradiometric measurements were taken using field spectrometers to obtain the reflectance values of volcanic sand over wet and dry conditions. The varying saturation levels of the sand due to rainfall were examined. The darkest pixel method was used to atmospherically correct a series of Landsat 5 and Landsat 7 satellite images. The mean in-situ in-band reflectance values as found from the ground measurements were compared with the at-satellite reflectance values following atmospheric correction. It was found that precipitation conditions such as rainfall affected the reflectance values of sand. The study found that wet sand had a significantly lower reflectance value compared to dry sand. Therefore, volcanic beach sand can be used as an indicator of precipitation in satellite images.