10 research outputs found

    Coastal Dune Vegetation Mapping Using a Multispectral Sensor Mounted on an UAS

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    Vegetation mapping, identifying the type and distribution of plant species, is important for analysing vegetation dynamics, quantifying spatial patterns of vegetation evolution, analysing the effectsof environmental changes and predicting spatial patterns of species diversity. Such analysis can contribute to the development of targeted land management actions that maintain biodiversity and ecological functions. This paper presents a methodology for 3D vegetation mapping of a coastal dune complex using a multispectral camera mounted on an unmanned aerial system with particular reference to the Buckroney dune complex in Co. Wicklow, Ireland. Unmanned aerial systems (UAS), also known as unmanned aerial vehicles (UAV) or drones, have enabled high-resolution and high-accuracy ground-based data to be gathered quickly and easily on-site. The Sequoia multispectral sensor used in this study has green, red, red edge and near-infrared wavebands, and a regular camer with red, green and blue wavebands (RGB camera), to capture both visible and near-infrared (NIR) imagery of the land surface. The workflow of 3D vegetation mapping of the study site included establishing coordinated ground control points, planning the flight mission and camera parameters, acquiring the imagery, processing the image data and performing features classification. The data processing outcomes included an orthomosaic model, a 3D surface model and multispectral imagery of the study site, in the Irish Transverse Mercator (ITM) coordinate system. The planimetric resolution of the RGB sensor-based outcomes was 0.024 m while multispectral sensor-based outcomes had a planimetric resolution of 0.096 m. High-resolution vegetation mapping was successfully generated from these data processing outcomes. There were 235 sample areas (1 m 1 m) used for the accuracy assessment of the classification of the vegetation mapping. Feature classification was conducted using nine diferent classification strategies to examine the efficiency of multispectral sensor data for vegetation and contiguous land cover mapping. The nine classification strategies included combinations of spectral bands and vegetation indices. Results show classification accuracies, based on the nine different classification strategies, ranging from 52% to 75%

    GEOSPATIAL-BASED ENVIRONMENTAL MODELLING FOR COASTAL DUNE ZONE MANAGEMENT

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    Tomaintain biodiversity and ecological functionof coastal dune areas, itis important that practical and effective environmentalmanagemental strategies are developed. Advances in geospatial technologies offer a potentially very useful source of data for studies in this environment. This research project aimto developgeospatialdata-basedenvironmentalmodellingforcoastaldunecomplexestocontributetoeffectiveconservationstrategieswithparticularreferencetotheBuckroneydunecomplexinCo.Wicklow,Ireland.Theprojectconducteda general comparison ofdifferent geospatial data collection methodsfor topographic modelling of the Buckroney dune complex. These data collection methodsincludedsmall-scale survey data from aerial photogrammetry, optical satellite imagery, radar and LiDAR data, and ground-based, large-scale survey data from Total Station(TS), Real Time Kinematic (RTK) Global Positioning System(GPS), terrestrial laser scanners (TLS) and Unmanned Aircraft Systems (UAS).The results identifiedthe advantages and disadvantages of the respective technologies and demonstrated thatspatial data from high-end methods based on LiDAR, TLS and UAS technologiesenabled high-resolution and high-accuracy 3D datasetto be gathered quickly and relatively easily for the Buckroney dune complex. Analysis of the 3D topographic modelling based on LiDAR, TLS and UAS technologieshighlighted the efficacy of UAS technology, in particular,for 3D topographicmodellingof the study site.Theproject then exploredthe application of a UAS-mounted multispectral sensor for 3D vegetation mappingof the site. The Sequoia multispectral sensorused in this researchhas green, red, red-edge and near-infrared(NIR)wavebands, and a normal RGB sensor. The outcomesincludedan orthomosiac model, a 3D surface model and multispectral imageryof the study site. Nineclassification strategies were usedto examine the efficacyof UAS-IVmounted multispectral data for vegetation mapping. These strategies involved different band combinations based on the three multispectral bands from the RGB sensor, the four multispectral bands from the multispectral sensor and sixwidely used vegetation indices. There were 235 sample areas (1 m × 1 m) used for anaccuracy assessment of the classification of thevegetation mapping. The results showed vegetation type classification accuracies ranging from 52% to 75%. The resultdemonstrated that the addition of UAS-mounted multispectral data improvedthe classification accuracy of coastal vegetation mapping of the Buckroney dune complex

    UAVs for the Environmental Sciences

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    This book gives an overview of the usage of UAVs in environmental sciences covering technical basics, data acquisition with different sensors, data processing schemes and illustrating various examples of application

    Remote Sensing Applications in Coastal Environment

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    Coastal regions are susceptible to rapid changes, as they constitute the boundary between the land and the sea. The resilience of a particular segment of coast depends on many factors, including climate change, sea-level changes, natural and technological hazards, extraction of natural resources, population growth, and tourism. Recent research highlights the strong capabilities for remote sensing applications to monitor, inventory, and analyze the coastal environment. This book contains 12 high-quality and innovative scientific papers that explore, evaluate, and implement the use of remote sensing sensors within both natural and built coastal environments

    Geo-Information Technology and Its Applications

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    Geo-information technology has been playing an ever more important role in environmental monitoring, land resource quantification and mapping, geo-disaster damage and risk assessment, urban planning and smart city development. This book focuses on the fundamental and applied research in these domains, aiming to promote exchanges and communications, share the research outcomes of scientists worldwide and to put these achievements better social use. This Special Issue collects fourteen high-quality research papers and is expected to provide a useful reference and technical support for graduate students, scientists, civil engineers and experts of governments to valorize scientific research

    Science-based restoration monitoring of coastal habitats, Volume Two: Tools for monitoring coastal habitats

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    Healthy coastal habitats are not only important ecologically; they also support healthy coastal communities and improve the quality of people’s lives. Despite their many benefits and values, coastal habitats have been systematically modified, degraded, and destroyed throughout the United States and its protectorates beginning with European colonization in the 1600’s (Dahl 1990). As a result, many coastal habitats around the United States are in desperate need of restoration. The monitoring of restoration projects, the focus of this document, is necessary to ensure that restoration efforts are successful, to further the science, and to increase the efficiency of future restoration efforts

    Conservation of U.K. dune system native Lacertidae species.

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    After years of decline, resulting in the extinction of the sand lizard Lacerta agilis in Wales, the species has now been returned to several dune system sites which also contain the viviparous lizard Zootoca vivipara. As dune system habitats are becoming an increasingly important habitat type in the UK for L. agilis, providing a relatively safe haven for these and Z. vivipara populations from anthropogenic change, it is time to ensure the long-term survival of these populations. In this study, environmentally advantageous conditions for detection of both species were established for three dune system sites in North-West Wales. Surface temperature, UV, cloud cover and wind speed were identified as being the most influential detection parameters, with cloud cover and wind speed noted as having a negative influence on detection. Furthermore, favoured habitat was identified and ‘suitable habitat’ modelled for both species. Across the research sites both species were found to utilise habitats of a similar composition with reintroduced L. agilis favouring specific habitat features such as basking direction and degree of angle of their basking position. Habitat and site utilisation models indicate that for highly mobile dune systems L. agilis dispersal across a site is not of concern. For static or eroding dune systems, large, connected areas of favoured habitats are absent. In this situation, L. agilis dispersal (from introduction locations) is limited. Mean yearly L. agilis dispersal distances of 19.64 m – 28 m represents an approximate trend across the three research sites. The physical presence of L. agilis alone, however, does not constitute a successful reintroduction. Genetic diversity of the reintroduced populations was observed to be lower than those calculated in naturally occurring British populations. This is a matter of conservation concern, with a number of targeted mitigatory measures proposed to improve the genetic integrity, reducing the chance of population extinction(s). Mean time to extinction estimates indicate that for populations on highly mobile dune systems population survival times of between 11.4 yrs and 63.1 yrs could be expected. This is reduced for static or eroding dune system sites. The implications of these findings for the conservation of L. agilis and Z. vivipara are discussed in the context of current challenges and future management requirements. It is hoped that this thesis will help guide the future development of the reintroduction program, and in addition, provide a sound scientific basis for the future management of reintroduction sites and species monitoring
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