Konstantinos Topouzelis

Konstantinos Topouzelis
University of the Aegean · Department of Marine Sciences

PhD

About

108
Publications
50,897
Reads
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2,045
Citations
Introduction
Dr. Konstantinos Topouzelis holds a Bachelor's degree in Environmental Studies (University of the Aegean, Department of Environment), a Master's degree in Remote Sensing (University of Dundee, Department of Applied Physics & Mechanical Engineering) and a Ph.D. in pollution monitoring from space (National Technical University of Athens, School of Rural and Surveying Engineering). Currently he is an assistant professor in the Department of Marine Sciences, University of the Aegean and he is leading the Marine Remote Sensing Group (MRSG) https://mrsg.aegean.gr/ His main research interest is on the analysis of remote sensing datasets, including satellite and aerial images, for marine and coastal applications.
Additional affiliations
August 2016 - August 2017
University of the Aegean
Position
  • Professor
February 2014 - present
University of the Aegean
Position
  • Lecturer

Publications

Publications (108)
Article
Sentinel-2 (S2) images have been used in several projects to detect large accumulations of marine litter and plastic targets. Their limited spatial resolution though hinders the detection of relatively small floating accumulations of marine debris. Thus, this study aims at overcoming this limit through the exploration of fusion with very high-resol...
Article
Unmanned Aerial Systems (UAS) have been recently used as a close-range remote sensing tool, providing high spatial and temporal resolutions compared to other remote sensing methods. Their abilities have constantly increased their use in many environmental studies with very satisfactory results. However, the acquisition of reliable information for a...
Article
Full-text available
Scientists in the marine domain process satellite images in order to extract information that can be used for monitoring, understanding, and forecasting of marine phenomena, such as turbidity, algal blooms and oil spills. The growing need for effective retrieval of related information has motivated the adoption of semantically aware strategies on s...
Article
Full-text available
Unmanned aerial systems (UAS, aka drones) are being used to map macro-litter on the environment. Sixteen qualified researchers (operators), with different expertise and nationalities, were invited to identify, mark and categorize the litter items (manual image screening, MS) on three UAS images collected at two beaches. The coefficient of concordan...
Article
Floating Marine Litter (FML) are mainly plastics or synthetic polymers that float on the sea surface after being deliberately discarded or unintentionally lost along beaches, rivers or marine environments. In recent years, much focus has been placed on locating, tracking and removing plastic items in both coastal areas and in the open ocean. The us...
Article
Full-text available
Biogenic films are very thin surface oils, frequently observed near aquaculture farms, that affect the roughness and the optical properties of the sea surface, making them visible in SAR and multispectral images. The purpose of this study is to investigate the potential of satellite SAR and multispectral sensors in the detection of biogenic oil fil...
Article
Full-text available
Hyperspectral PRISMA images are new and have not yet been evaluated for their ability to detect marine plastic litter. The hyperspectral PRISMA images have a fine spectral resolution, however, their spatial resolution is not high enough to enable the discrimination of small plastic objects in the ocean. Pansharpening with the panchromatic data enha...
Article
Full-text available
Windrow is a long-established term for the aggregations of seafoam, seaweeds, plankton and natural debris that appear on the ocean surface. Here, we define a “litter windrow” as any aggregation of floating litter at the submesoscale domain (<10 km horizontally), regardless of the force inducing the surface convergence, be it wind or other forces su...
Article
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Whilst both plastic production and inputs at sea have increased since the 1950s, several modelling studies predict a further increase in the coming years in these respective quantities. We compiled scientific literature on trends in marine litter, consisting largely of plastic and microplastics in the ocean, understanding that monitoring programs o...
Article
Full-text available
Marine litter (ML) accumulation in the coastal zone has been recognized as a major problem in our time, as it can dramatically affect the environment, marine ecosystems, and coastal communities. Existing monitoring methods fail to respond to the spatiotemporal changes and dynamics of ML concentrations. Recent works showed that unmanned aerial syste...
Article
Full-text available
Marine conservation and management require detailed and accurate habitat mapping, which is usually produced by collecting data using remote sensing methods. In recent years, unmanned aerial systems (UAS) are used for marine data acquisition, as they provide detailed and reliable information through very high-resolution orthophoto-maps. However, as...
Article
Full-text available
The objective of this study is to evaluate the efficiency of two well-known algorithms (Ocean Colour 4 for MERIS [OC4Me] and neural net [NN]) used in the calculation of chlorophyll-a (Chl-a) from the Sentinel-3 Ocean and Land Colour Instrument (OLCI) compared to in situ measurements covering the Mediterranean Sea. In situ data set, obtained from th...
Article
Full-text available
The identification of oceanographic circulation related features is a valuable tool for environmental and fishery management authorities, commercial use and institutional research. Remote sensing techniques are suitable for detection, as in situ measurements are prohibitively costly, spatially sparse and infrequent. Still, these imagery application...
Article
Full-text available
Marine habitat mapping is essential for updating existing information, preserving, and protecting the marine environment. Unmanned Aerial Systems (UAS) are an important tool for monitoring and mapping coastal and marine environment because of their ability to provide very high-resolution aerial imagery.Environmental conditions have a critical role...
Article
Full-text available
The use of unmanned aerial systems (UAS) over the past years has exploded due to their agility and ability to image an area with high-end products. UAS are a low-cost method for close remote sensing, giving scientists high-resolution data with limited deployment time, accessing even the most inaccessible areas. This study aims to produce marine hab...
Article
Full-text available
Sustained observations are required to determine the marine plastic debris mass balance and to support effective policy for planning remedial action. However, observations currently remain scarce at the global scale. A satellite remote sensing system could make a substantial contribution to tackling this problem. Here, we make initial steps towards...
Article
Full-text available
Aerial surveys in coastal areas using Unmanned Aerial Vehicles (UAVs) present many limitations. However, the need for detailed and accurate information in a marine environment has made UAVs very popular. The aim of this paper is to present a protocol which summarizes the parameters that affect the reliability of the data acquisition process over th...
Article
Full-text available
In the last year, the Greek islands of the eastern Aegean Sea were the main entrance points used by refugees arriving in the EU. The crossing between Turkey and the eastern Aegean islands is carried out using mostly small inflatable boats. Additionally, wooden and plastic vessels of various sizes are abandoned at the beaches upon arrival together w...
Preprint
Full-text available
Marine domain awareness is important for crisis management in case of accidents but also as a surveillance tool against illicit discharge activities. Copernicus Sentinel-1 data are used for the detection of spills as they are provided free and in near real time. The availability of data and the recently developed cloud infrastructures give the oppo...
Article
Full-text available
Dynamic processes in coastal zones and human activities in the coastal environment produce pressure on cultural heritage, especially in touristic places. Unmanned aerial systems (UAS) are used as an additional tool for monitoring cultural heritage sites in sensitive coastal areas. UASs provide low-cost accurate spatial data and high-resolution imag...
Article
A rapidly rising amount of plastic litter on land and at sea is becoming a global wicked environmental problem. Here, we present an innovative exploratory application of unmanned aerial systems (UAS) and open-access satellite imagery in remote detection of floating plastics in natural seawater, through a dedicated aquatic environment experiment. We...
Conference Paper
Full-text available
In the epoch of anthropogenic climate change that nature is traversing, the vastly biodiverse coastal ecosystems in Mediterranean suffer from significant impacts. The silent, overlooked and degraded, yet remarkable ecosystem service providers, Mediterranean seagrasses can mitigate the resulting impacts by relentlessly sequestering the so-called ‘bl...
Article
Coastline change and human activities in shoreline zones are two factors indicating the vulnerability and the quality of a coastal environment. In this article, coastline evolution and spatiotemporal differences on coastal touristic infrastructure are presented as two case studies. Both case studies have increasing interest among scientists monitor...
Conference Paper
Full-text available
MARINE-EO is a Research and Development project using a Pre-Commercial Procurement (PCP) mechanism with the scope to develop innovative beyond the state-of-the-art downstream applications which meet the demand of maritime authorities and stakeholders, leveraging on the existing services and other products from the Copernicus portfolio. More specifi...
Article
MARINE-EO is a Research and Development project using a Pre-Commercial Procurement (PCP) mechanism with the scope to develop innovative beyond the state-of-the-art downstream applications which meet the demand of maritime authorities and stakeholders, leveraging on the existing services and other products from the Copernicus portfolio. More specifi...
Conference Paper
Last years the role of Unmanned Aerial Systems becoming more and more crucial in a wide variety of scientific aspects that need fast and reliable geodata to monitor coastal cultural heritage areas. The dynamic processes in the coastal zone and human activities on the coastal environment produce pressure in cultural heritage especially in touristic...
Article
Full-text available
An important population of the endemic Mediterranean fan mussel Pinna nobilis thrives in the marine protected area of the Gera Gulf (Lesvos island, northeastern Aegean Sea, Greece), and was assessed for the first time. To estimate the abundance, spatial distribution and habitat use of fan mussels in the Gera Gulf, a distance sampling underwater sur...
Article
Full-text available
Seagrasses are traversing the epoch of intense anthropogenic impacts that significantly decrease their coverage and invaluable ecosystem services, necessitating accurate and adaptable, global-scale mapping and monitoring solutions. Here, we combine the cloud computing power of Google Earth Engine with the freely available Copernicus Sentinel-2 mult...
Conference Paper
The collection of detailed and accurate information about marine habitats and flora species is crucial for mapping, monitoring and management of marine and coastal environments. Remote sensing is widely used to collect information at marine environments, while in recent years the potential use of UAS for mapping is examined. The aim of this paper i...
Conference Paper
Abstract Last years the role of Unmanned Aerial Systems becoming more and more crucial in a wide variety of scientific aspects that need fast and reliable geodata. Nowadays UAS have a prominent role in post-earthquake damage assessment as they are capable of collecting high in resolution data for mapping the results of a catastrophic event. The imp...
Conference Paper
Seagrass meadows play a vital role in coastal ecosystems health as constitute an important pillar of the coastal environment. So far, regional scale habitat mapping was implemented with the use of freely available medium scale satellite images (Sentinel-2 or Landsat-8). The Unmanned Aerial Systems (UAS) have increase the spatial resolution of the o...
Article
Seagrass meadows are one of the most important coastal habitats across the globe. These are mainly constituted by the marine plants of the genus Posidonia and Thalassia. In the Mediterranean Sea, Posidonia oceanica is the dominant endemic plant that affects physical, biogeochemical and biological processes. The decline in the spatial distribution h...
Conference Paper
Full-text available
This study presents the methodology followed for the evaluation of buildings damage after the earthquake of 12 th of June in Vryssa, Lesvos island. For this purpose, VHR multispectral images from a flight from a UAS were acquired. The methodology consisted of two main steps. Firstly, through the orthorectification and radiometric calibration proced...
Conference Paper
Full-text available
The aim of this paper is to present the methodology followed and the results obtained by the synergistic exploitation of geo-information methods towards 3D mapping of the impact of the catastrophic earthquake of June 12th 2017 on the traditional settlement of Vrisa on the island of Lesvos, Greece. A campaign took place for collecting: a) more than...
Conference Paper
Full-text available
Efficient and effective spatial data collection is crucial in cases of catastrophic events. Resources efficiency and project effectiveness are two aspects that need special attention especially when there are spatial and temporal constraints. There is limited literature regarding efficiency and effectiveness in spatial data collection approaches. T...
Article
Full-text available
Efficient and effective spatial data collection is crucial in cases of catastrophic events. Resources efficiency and project effectiveness are two aspects that need special attention especially when there are spatial and temporal constraints. There is limited literature regarding efficiency and effectiveness in spatial data collection approaches. T...
Article
Seagrass meadows are among the most valuable coastal ecosystems on earth due to their structural and functional roles in the coastal environment. This study demonstrates remote sensing's capacity to produce seagrass distribution maps on a regional scale. The seagrass coverage maps provided here describe and quantify for the first time the extent an...
Article
Full-text available
The effective conservation of marine biodiversity through an integrated ecosystem-based management approach requires a sound knowledge of the spatial distribution of habitats and species. Although costly in terms of time and resources, acquiring such information is essential for the development of rigorous management plans and the meaningful priori...
Conference Paper
The significance of coastal habitat mapping lies in the need to prevent from anthropogenic interventions and other factors. Until 2015, Landsat-8 (30m) imagery were used as medium spatial resolution satellite imagery. So far, Sentinel-2 satellite imagery is very useful for more detailed regional scale mapping. However, the use of high resolution or...
Conference Paper
Coastline change and marine litter concentration in shoreline zones are two different emerging problems indicating the vulnerability as well as the quality of a coastal environment. Both problems present spatiotemporal changes due to weather and anthropogenic factors. Traditionally spatiotemporal changes in coastal environments are monitored using...
Conference Paper
Full-text available
Beaches, which form the most significant natural resource of the Aegean Archipelago, are under increasing erosion risk due to projected mean sea level rise (MSLR) and changes in the magnitude/frequency of extreme sea levels (ESLS). In the framework of the ERABEACH project, the erosion risk of all beaches of 6 Aegean islands (Lesvos, Chios, Thira, K...
Article
Full-text available
One of the most important linear features on the monitoring of coastline is critical. The study of coastal system processes and coastal zone environmental management requires the information about coastlines and their changes. In this study, a methodology that extracts coastline efficiently by processing high-resolution orthophotos derived by UAV i...
Article
For the effective conservation of vulnerable marine populations, knowledge of their distributions and spatially-explicit management actions are essential. The use of physical features or coarse habitat types as surrogates of species distribution often does not provide an accurate enough, and hence useful, mapping of where species occur. This is fur...
Chapter
Operational monitoring of oil discharges using synthetic aperture radar (SAR) images contributes significantly toward fewer occurrences of oil spills on the sea surface. Until now commercial satellites like ERS-1/2, ENVISAT, Radarsat-1/2, TerraSAR-X, and COSMO-SkyMed were used for this purpose. However, their data availability was challenging and r...
Conference Paper
Full-text available
Satellite remote sensing investigation can contribute to a multitude of applications such as the study of the environment and oceanography. The aim of this study is to present the space-time variation between specific environmental parameters for a period of eleven years (2000 2010) in the region of Northeast Aegean. This study produced conclusions...
Poster
In the present work we study the correlation of surface suspended material concentrations (SPM) derived from medium-scale satellite data (spatial resolution of 30m) with the diffuse attenuation coefficient (Kd490) in the water column of N. Aegean Sea. Furthermore, their effect in the identification of seagrass meadows (mainly Posidonia) was examine...
Poster
Full-text available
In the present work we study the correlation of surface suspended material concentrations (SPM) derived from medium-scale satellite data (spatial resolution of 30m) with the diffuse attenuation coefficient (Kd490) in the water column of N. Aegean Sea. Furthermore, their effect in the identification of seagrass meadows (mainly Posidonia) was examine...
Poster
Full-text available
According to the Aichi Biodiverity Target 11 set by the Convention on Biological Diversity, states are committed to protect 10% of marine coastal areas by 2020. In line with this, the ultimate goal of the MARISCA project is to propose a network of Marine Protected Areas (MPAs) for the conservation of all important and vulnerable habitats and specie...