The aim of this thesis was to study coastal waters around the Volturno River mouth (southern Italy) by means of remote sensing techniques. For the purpose of the project five images were acquired between 2011 and 2014 from sensors mounted on both spaceborne and airborne platforms: MIVIS (26/07/2011), Hyperion (01/07/2012), Daedalus ATM (01/08/2012), RapidEye (11/08/2013) and Landsat OLI (09/09/2014). One fieldwork was organized in summer 2014 in order to optically characterize coastal waters using both radiometric measurements and measuring the concentration of optically active water components (i.e. Total Suspended Matter (TSM), Chlorophyll-a (Chl-a) and Colored Dissolved Organic Matter (CDOM)). Images were pre-processed in terms of geo-codification, co-registration, radiometric calibration and atmospheric correction. The elaboration of remotely sensed images included coastline extraction, image classification for the production of water complexity classes and the application of one empirical approach in order to derive maps of Chl-a, TSM and CDOM concentration along coastal waters. The empirical approach was based on finding the best correlation between spectral band ratios and in-situ measured Chl-a, TSM and CDOM concentrations. Through the application of the selected empirical algorithms, maps of Chl-a, TSM and CDOM concentration were obtained for coastal waters from the OLI image. The results showed an increasing gradient of water complexity from pelagic waters toward the coast, as well as a spatial variation in Chl-a, TSM and CDOM concentrations in complex waters near the coast. Generally, TSM concentration gathered from the application of empirical algorithm, is high compared to Chl-a and CDOM concentrations along coastal complex waters. Coastlines extracted from the higher spatial resolution images (Daedalus ATM, MIVIS and RapidEye) were compared, highlighting some changes in the shape of the coast and coastal surface area during time. Both progressions and regressions were observed, which are supposed to be related to both artificial and natural processes such as, man-made constructions and deconstructions, sea level changes and shoreline erosion.
L’obiettivo di questa tesi è lo studio delle acque costiere antistanti la foce del fiume Volturno (Italia meridionale) tramite l’utilizzo di tecniche di telerilevamento. A tale scopo, sono state considerate cinque immagini remote durante il periodo compreso tra il 2011 e il 2014. Le immagini sono state acquisite sia da sensori satellitari che aerei: le acquisizioni satellitari comprendono un’immagine Hyperion (01/07/2012), un’immagine RapidEye (11/08/2013) ed un’immagine LANDSAT OLI (09/09/2014), mentre per le acquisizioni aeree sono state scelte un’immagine MIVIS (26/06/2011) ed un’immagine Daedalus ATM (01/08/2012). A supporto dell’elaborazione delle immagini è stata condotta una campagna di misura in Agosto 2014 con lo scopo di caratterizzare otticamente le acque dell’area di studio tramite misure radiometriche e misure di concentrazione dei parametri otticamente attivi delle acque (Clorofilla-a (Chl-a), Sedimenti Totali Sospesi (TSM) e Sostanza Organica Colorata Disciolta (CDOM)). Le immagini remote sono state prima di tutto pre-processate applicando procedure di geocodifica, co-registrazione, correzione radiometrica ed atmosferica. Le successive fasi di elaborazione delle immagini hanno permesso di estrarre la linea di costa per le diverse date di acquisizione, di caratterizzare le acque marino-costiere in diversi gradi di complessità ottica e di derivare mappe di concentrazione relative a Chl-a, TSM e CDOM tramite l’applicazione di un approccio empirico. Tale approccio si basa sull’analisi della correlazione tra valori spettrali di riflettanza dell’acqua (es. rapporti tra valori di riflettanza in diverse regioni spettrali) e corrispondenti misure di concentrazione di Chl-a, TSM e CDOM. Le relazioni che meglio descrivono il comportamento dei dati misurati in campo sono state utilizzate per mappare la concentrazione delle tre componenti acquatiche lungo la fascia di acque otticamente complesse individuata nell’immagine OLI. I risultati mostrano un gradiente crescente di complessità ottica delle acque passando da acque pelagiche ad acque costiere. Nelle acque costiere otticamente complesse è stata osservata una variabilità spaziale della concentrazione di Chl-a, TSM e CDOM. Inoltre, dall’applicazione degli algoritmi empirici si nota come la concentrazione di TSM sembra essere più rilevante rispetto alla concentrazione delle altre due componenti acquatiche. Tramite il confronto delle linee di costa estratte dalle immagini a più alta risoluzione spaziale (Daedalus ATM, MIVIS e RapidEye) è stato possibile riscontrare alcuni cambiamenti nella forma della linea costiera nel tempo. Sono state osservate sia progressioni che regressioni della costa, probabilmente legate sia a processi naturali (es. erosione costiera) che antropici (es. realizzazione di nuove opere di mantenimento della costa).
Remote sensing observations for monitoring coastal zones : Volturno river mouth case study
DANESHGAR, SABA
2014/2015
Abstract
The aim of this thesis was to study coastal waters around the Volturno River mouth (southern Italy) by means of remote sensing techniques. For the purpose of the project five images were acquired between 2011 and 2014 from sensors mounted on both spaceborne and airborne platforms: MIVIS (26/07/2011), Hyperion (01/07/2012), Daedalus ATM (01/08/2012), RapidEye (11/08/2013) and Landsat OLI (09/09/2014). One fieldwork was organized in summer 2014 in order to optically characterize coastal waters using both radiometric measurements and measuring the concentration of optically active water components (i.e. Total Suspended Matter (TSM), Chlorophyll-a (Chl-a) and Colored Dissolved Organic Matter (CDOM)). Images were pre-processed in terms of geo-codification, co-registration, radiometric calibration and atmospheric correction. The elaboration of remotely sensed images included coastline extraction, image classification for the production of water complexity classes and the application of one empirical approach in order to derive maps of Chl-a, TSM and CDOM concentration along coastal waters. The empirical approach was based on finding the best correlation between spectral band ratios and in-situ measured Chl-a, TSM and CDOM concentrations. Through the application of the selected empirical algorithms, maps of Chl-a, TSM and CDOM concentration were obtained for coastal waters from the OLI image. The results showed an increasing gradient of water complexity from pelagic waters toward the coast, as well as a spatial variation in Chl-a, TSM and CDOM concentrations in complex waters near the coast. Generally, TSM concentration gathered from the application of empirical algorithm, is high compared to Chl-a and CDOM concentrations along coastal complex waters. Coastlines extracted from the higher spatial resolution images (Daedalus ATM, MIVIS and RapidEye) were compared, highlighting some changes in the shape of the coast and coastal surface area during time. Both progressions and regressions were observed, which are supposed to be related to both artificial and natural processes such as, man-made constructions and deconstructions, sea level changes and shoreline erosion.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/103481