Costas Armenakis

Dr. Costas Armenakis

Associate Professor and Program Director, Geomatics Engineering, Department of Earth and Space Science and Engineering, Lassonde School of Engineering, York University, Ontario, Canada

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 July 2018 in Geosciences
Verified
Journal Article
Open access
PDF file
DRDaniela Rincón
Daniela Rincón
UKUsman T Khan
Usman T Khan
CACostas Armenakis
Costas Armenakis
Given the increase in flood events in recent years, accurate flood risk assessment is an important component of flood mitigation in urban areas. This research aims to develop updated and accurate flood risk maps in the Don River Watershed within the Great Toronto Area (GTA). The risk maps use geographical information systems (GIS) and multi-criteria analysis along with the application of Analytical Hierarchy Process methods to define and quantify the optimal selection of weights for the criteria that contribute to flood risk. The flood hazard maps were generated for four scenarios, each with different criteria (S1, S2, S3, and S4). The base case scenario (S1) is the most accurate, since it takes into account the floodplain map developed by the Toronto and Region Conservation Authority. It also considers distance to streams (DS), height above nearest drainage (HAND), slope (S), and the Curve Number (CN). S2 only considers DS, HAND, and CN, whereas S3 considers effective precipitation (EP), DS, HAND, and S. Lastly, S4 considers total precipitation (TP), DS, HAND, S, and CN. In addition to the flood hazard, the social and economic vulnerability was included to determine the total flood vulnerability in the watershed under three scenarios; the first one giving a higher importance to the social vulnerability, the second one giving equal importance to both social and economic vulnerability, and the third one giving more importance to the economic vulnerability. The results for each of the four flood scenarios show that the flood risk generated for S2 is the most similar to the base case (S1), followed by S3 and S4. The inclusion of social and economic vulnerability highlights the impacts of floods that are typically ignored in practice. It will allow watershed managers to make more informed decisions for flood mitigation and protection. The most important outcome of this research is that by only using the digital elevation model, the census data, the streams, land use, and soil type layers, it is possible to obtain a reliable flood risk map (S2) using a simplified method as compared to more complex flood risk methods that use hydraulic and hydrological models to generate flood hazard maps (as was the case for S1).

27 November 2017 in Geosciences
Verified
Journal Article
Open access
PDF file
CACostas Armenakis
Costas Armenakis
EDErin Xinheng Du
Erin Xinheng Du
SNSowmya Natesan
Sowmya Natesan
RPRavi Persad
Ravi Persad
YZYing Zhang
Ying Zhang
Flood maps alone are not sufficient to determine and assess the risks to people, property, infrastructure, and services due to a flood event. Simply put, the risk is almost zero to minimum if the flooded region is “empty” (i.e., unpopulated, has not properties, no industry, no infrastructure, and no socio-economic activity). High spatial resolution Earth Observation (EO) data can contribute to the generation and updating of flood risk maps based on several aspects including population, economic development, and critical infrastructure, which can enhance a city’s flood mitigation and preparedness planning. In this case study for the Don River watershed, Toronto, the flood risk is determined and flood risk index maps are generated by implementing a methodology for estimating risk based on the geographic coverage of the flood hazard, vulnerability of people, and the exposure of large building structures to flood water. Specifically, the spatial flood risk index maps have been generated through analytical spatial modeling which takes into account the areas in which a flood hazard is expected to occur, the terrain’s morphological characteristics, socio-economic parameters based on demographic data, and the density of large building complexes. Generated flood risk maps are verified through visual inspection with 3D city flood maps. Findings illustrate that areas of higher flood risk coincide with areas of high flood hazard and social and building exposure vulnerability.

21 July 2021 in Sustainability
Verified
Journal Article
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XHXuyang Han
Xuyang Han
CACostas Armenakis
Costas Armenakis
Mojgan JadidiMojgan Jadidi
Mojgan Jadidi
Today, maritime transportation represents a substantial portion of international trade. Sustainable development of marine transportation requires systematic modeling and surveillance for maritime situational awareness. In this paper, we present an enhanced density-based spatial clustering of applications with noise (DBSCAN) method to model vessel behaviours based on trajectory point data. The proposed methodology enhances the DBSCAN clustering performance by integrating the Mahalanobis distance metric, which considers the correlation between the points representing vessel locations. This research proposes applying the clustering method to historical Automatic Identification System (AIS) data using an algorithm to generate a clustering model of the vessels’ trajectories and a model for detecting vessel trajectory anomalies, such as unexpected stops, deviations from regulated routes, or inconsistent speed. Further, an automatic and data-driven approach is proposed to select the initial parameters for the enhanced DBSCAN approach. Results are presented from two case studies using an openly available Gulf of Mexico AIS dataset as well as a Saint Lawrence Seaway and Great Lakes AIS licensed dataset acquired from ORBCOMM (a maritime AIS data provider). These research findings demonstrate the applicability and scalability of the proposed method for modeling more water regions, contributing to situational awareness, vessel collision prevention, safe navigation, route planning, and detection of vessel behaviour anomalies for auto-vessel development towards the sustainability of marine transportation.

1 December 2020 in Journal of Unmanned Vehicle Systems
Verified
Journal Article
Closed access
SNSowmya Natesan
Sowmya Natesan
CACostas Armenakis
Costas Armenakis
UVUdayalakshmi Vepakomma
Udayalakshmi Vepakomma
Tree species identification at the individual tree level is crucial for forest operations and management, yet its automated mapping remains challenging. Emerging technology, such as the high-resolution imagery from unmanned aerial vehicles (UAV) that is now becoming part of every forester’s surveillance kit, can potentially provide a solution to better characterize the tree canopy. To address this need, we have developed an approach based on a deep Convolutional Neural Network (CNN) to classify forest tree species at the individual tree-level that uses high-resolution RGB images acquired from a consumer-grade camera mounted on a UAV platform. This work explores the ability of the Dense Convolutional Network (DenseNet) to classify commonly available economic coniferous tree species in eastern Canada. The network was trained using multitemporal images captured under varying acquisition parameters to include seasonal, temporal, illumination, and angular variability. Validation of this model using distinct images over a mixed-wood forest in Ontario, Canada, showed over 84% classification accuracy in distinguishing five predominant species of coniferous trees. The model remains highly robust even when using images taken during different seasons and times, and with varying illumination and angles.

20 April 2018 in Drones
Verified
Journal Article
Open access
PDF file
SNSowmya Natesan
Sowmya Natesan
CACostas Armenakis
Costas Armenakis
GBGuy Benari
Guy Benari
RLRegina Lee
Regina Lee
Unmanned aerial vehicles (UAV) are being used for low altitude remote sensing for thematic land classification using visible light and multi-spectral sensors. The objective of this work was to investigate the use of UAV equipped with a compact spectrometer for land cover classification. The UAV platform used was a DJI Flamewheel F550 hexacopter equipped with GPS and Inertial Measurement Unit (IMU) navigation sensors, and a Raspberry Pi processor and camera module. The spectrometer used was the FLAME-NIR, a near-infrared spectrometer for hyperspectral measurements. RGB images and spectrometer data were captured simultaneously. As spectrometer data do not provide continuous terrain coverage, the locations of their ground elliptical footprints were determined from the bundle adjustment solution of the captured images. For each of the spectrometer ground ellipses, the land cover signature at the footprint location was determined to enable the characterization, identification, and classification of land cover elements. To attain a continuous land cover classification map, spatial interpolation was carried out from the irregularly distributed labeled spectrometer points. The accuracy of the classification was assessed using spatial intersection with the object-based image classification performed using the RGB images. Results show that in homogeneous land cover, like water, the accuracy of classification is 78% and in mixed classes, like grass, trees and manmade features, the average accuracy is 50%, thus, indicating the contribution of hyperspectral measurements of low altitude UAV-borne spectrometers to improve land cover classification.

18 August 2017 in The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Verified
Journal Article
Open access
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AAAbdullah Albourae
Abdullah Albourae
CACostas Armenakis
Costas Armenakis
MKM. Kyan
M. Kyan
Keywords: Heritage, Visualization, 3D Modelling, Augmented Reality, HBIM With the increased exposure to tourists, historical monuments are at an ever-growing risk of disappearing. Building Information Modelling (BIM) offers a process of digitally documenting of all the features that are made or incorporated into the building over its life-span, thus affords unique opportunities for information preservation. BIM of historical buildings are called Historical Building Information Models (HBIM). This involves documenting a building in detail throughout its history. Geomatics professionals have the potential to play a major role in this area as they are often the first professionals involved on construction development sites for many Architectural, Engineering, and Construction (AEC) projects. In this work, we discuss how to establish an architectural database of a heritage site, digitally reconstruct, preserve and then interact with it through an immersive environment that leverages BIM for exploring historic buildings. The reconstructed heritage site under investigation was constructed in the early 15th century. In our proposed approach, the site selection was based on many factors such as architectural value, size, and accessibility. The 3D model is extracted from the original collected and integrated data (Image-based, range-based, CAD modelling, and land survey methods), after which the elements of the 3D objects are identified by creating a database using the BIM software platform (Autodesk Revit). The use of modern and widely accessible game engine technology (Unity3D) is explored, allowing the user to fully embed and interact with the scene using handheld devices. The details of implementing an integrated pipeline between HBIM, GIS and augmented and virtual reality (AVR) tools and the findings of the work are presented.