Search results for "water surface"
showing 3 items of 3 documents
Monitoring Water Surface and Level of a Reservoir Using Different Remote Sensing Approaches and Comparison with Dam Displacements Evaluated via GNSS
2018
Remote sensing allowed monitoring the reservoir water level by estimating its surface extension. Surface extension has been estimated using different approaches, employing both optical (Landsat 5 TM, Landsat 7 ETM+ SLC-Off, Landsat 8 OLI-TIRS and ASTER images) and Synthetic Aperture Radar (SAR) images (Cosmo SkyMed and TerraSAR-X). Images were characterized by different acquisition modes, geometric and spectral resolutions, allowing the evaluation of alternative and/or complementary techniques. For each kind of image, two techniques have been tested: The first based on an unsupervised classification and suitable to automate the process, the second based on visual matching with contour lines…
Detection of a reservoir water level using shape similarity metrics
2017
The matching between reservoirs’ water edge and digital elevation model’s (DEM) contour lines allowed determining the water level at the acquisition date of satellite images. A preliminary study was conducted on the Castello dam (Magazzolo Lake), between Alessandria della Rocca and Bivona (Agrigento, south-Italy). The accuracy assessment of the technique was than evaluated from the comparison between classified and reference objects using similarity metrics about the shape, theme, edge and position, through the plugin STEP of open source software GIS. Moreover, an independent GIS technique was implemented to evaluate the water level, based on a distances’ array between existing contour line…
Dam displacements monitoring by using GNSS and remote sensing techniques
Il presente lavoro mira a valutare le potenzialità delle tecniche satellitari per il monitoraggio delle dighe. In particolare, l’attenzione è stata rivolta alle dighe di terra, poichè queste rappresentano la tipologia costruttiva più diffusa ed i modelli esistenti in letteratura sono in grado di descriverne gli spostamenti solo nell’ipotesi di conoscere accuratamente tutti parametri geotecnici e strutturali che caratterizzano la composizione della diga stessa. Negli ultimi anni, è stato ampiamente dimostrato che le tecniche satellitari da remoto sono in grado di individuare con elevata accuratezza, il comportamento di grandi strutture (incluse le dighe), valutandone spostamenti e deformazio…