Evolution of a beach–dune system following a catastrophic storm overwash event: Greenwich Dunes, Prince Edward Island, 1936–2005

Greenwich Dunes, Prince Edward Island National Park, is a sandy mainland and barrier spit beach–dune complex stretching for about 10 km along the northeast shore of Prince Edward Island, Canada. In October 1923, surge associated with an intense storm produced catastrophic overwash along the whole length of the study area. Subsequent evolution of the system was quantified from historic aerial photographs taken in 1936, 1953, 1971, 1997, and 2005. Orthophoto mosaics were generated for each photo set using PCI Geomatica OrthoEngine, a digital photogrammetric software. Linear changes in shoreline position and areal changes in geomorphic units were evaluated for each photo set. In addition, digital elevation models (DEMs) were extracted from the 1953, 1971, and 1997 aerial photos, enabling analysis of topographic and volumetric changes. The 1936 photos show complete destruction of all foredunes, with overwash and transgressive dunes extending 300 to 600 m inland. A descriptive model of the stages of evolution of the system is proposed based on the processes controlling overwash healing and dune stabilization. Detailed topographic and volumetric changes associated with the development of an extensive transgressive dunefield and subsequent stabilization as a result of reduced sand supply due to the growth of a new vegetated foredune complex and vegetation colonization are doccumented for each stage. It was nearly 40 years before a continuous foredune system was re-established and a further 30 years before the inland transgressive dunes became completely stabilized.

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MODEL PENDUGAAN DIAMETER POHON BERBASIS CITRA UNMANNED AERIAL VEHICLE (UAV) PADA HUTAN HUJAN TROPIS PAPUA: STUDI DI PULAU MANSINAM PAPUA BARAT (Model of Tree Diameter Estimation Based on Unmanned Aerial Vehicle (UAV) Image in Papua Tropical Rain Forest: a Study in Mansinam Island Papua Barat)

Jurnal Penelitian Kehutanan Faloak ◽

10.20886/jpkf.2021.5.1.16-30 ◽

2021 ◽

Vol 5 (1) ◽

pp. 16-30

Author(s):

Francine Hematang ◽

◽

Agustinus Murdjoko ◽

Hendri Hendri ◽

◽

...

Keyword(s):

Digital Elevation Model ◽

Unmanned Aerial Vehicle ◽

Land Surface ◽

Aerial Photographs ◽

Aerial Photos ◽

Digital Elevation ◽

Aerial Vehicle ◽

Papua Barat ◽

Elevation Model ◽

Uav Image

Abstract Unmanned aerial vehicles (UAV) have often been used for various purposes, not only for photography but also have been used for science in various scientific fields, including forestry. UAV has the ability to move freely in the air and record objects on the ground with high spatial resolution and wide area coverage. This study aimed to estimate the diameter at breast height (DBH) based on the image generated from the UAV. UAV was used to obtain aerial photographs taken at an altitude of 150 m above the land surface in four sample areas of 27 ha at the study site. Aerial photos were processed using agisoft photoscan software to produce a Digital Elevation Model (DEM) and orthophoto. Tree crowns were delineated from orthophoto and analyzed to obtain crown area and diameter. DBH measurements in the field were carried out on 206 sample trees used to build a DBH estimator model. The correlation test results showed that the crown diameter has a high correlation with DBH so that this variable was used as an independent variable. The best DBH estimator model was the polynomial model with the equation y = 0.0118744 x² + 1.08835 x + 22.8125, where y is DBH and x is the canopy diameter of the aerial photo interpretation results. Estimating DBH using UAV has several benefits, such as reducing time, cost and labour. Abstrak Unmanned aerial vehicle (UAV) sudah sering digunakan untuk berbagai tujuan, bukan hanya untuk fotografi, namun telah dimanfaatkan untuk sains di berbagai bidang keilmuan, termasuk bidang kehutanan. UAV memiliki kemampuan bergerak dengan bebas di udara dan merekam objek di darat dengan resolusi spasial tinggi, dan cakupan areal yang luas. Penelitian ini bertujuan untuk melakukan pendugaan diameter setinggi dada (DBH) berdasarkan citra yang dihasilkan dari UAV. UAV digunakan untuk memperoleh foto udara yang diambil pada ketinggian 150 m di atas permukaan darat pada empat areal sampel seluas 27 ha di lokasi penelitian. Foto udara diproses dengan menggunakan perangkat lunak agisoft photoscan untuk menghasilkan Digital Elevation Model (DEM) dan ortofoto. Tajuk pohon dideliniasi dari ortofoto dan dianalisis untuk memperoleh luas dan diameter tajuk. Pengukuran DBH di lapangan dilakukan terhadap 206 pohon sampel yang selanjutnya digunakan untuk membangun model penduga DBH. Hasil uji korelasi menunjukkan bahwa diameter tajuk mempunyai korelasi yang tinggi dengan DBH sehingga variable ini digunakan sebagai variable bebas. Model terbaik penduga DBH adalah model polinomial dengan persamaan y = 0,0118744 x² + 1,08835 x + 22,8125, dengan y adalah DBH dan x adalah diameter tajuk hasil interpretasi foto udara. Pendugaan DBH menggunakan UAV memiliki beberapa manfaat seperti mampu mengurangi waktu, biaya dan tenaga kerja.

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Classification of vegetation in Cucphuong National Park with the aim of large-scale mapping, Vietnam

Geobotanical mapping ◽

10.31111/geobotmap/1994-1995.64 ◽

1996 ◽

pp. 64-67 ◽

Cited By ~ 1

Author(s):

Nguen Nghia Thin ◽

Nguen Ba Thu ◽

Tran Van Thuy

Keyword(s):

National Park ◽

Large Scale ◽

Satellite Images ◽

Field Work ◽

Aerial Photographs ◽

Vegetation Map ◽

Dense Forest ◽

Broad Leaved Forest ◽

Leaved Forest

The tropical seasonal rainy evergreen broad-leaved forest vegetation of the Cucphoung National Park has been classified and the distribution of plant communities has been shown on the map using the relations of vegetation to geology, geomorphology and pedology. The method of vegetation mapping includes: 1) the identifying of vegetation types in the remote-sensed materials (aerial photographs and satellite images); 2) field work to compile the interpretation keys and to characterize all the communities of a study area; 3) compilation of the final vegetation map using the combined information. In the classification presented a number of different level vegetation units have been identified: formation classes (3), formation sub-classes (3), formation groups (3), formations (4), subformations (10) and communities (19). Communities have been taken as mapping units. So in the vegetation map of the National Park 19 vegetation categories has been shown altogether, among them 13 are natural primary communities, and 6 are the secondary, anthropogenic ones. The secondary succession goes through 3 main stages: grassland herbaceous xerophytic vegetation, xerophytic scrub, dense forest.

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COASTAL ALTERATION AND CHANGES IN SHORELINE MORPHOLOGY DUE TO ARTIFICIAL STRUCTURES IN MIIRAKU TOWN ON FUKUE IS. IN THE GOTO ARCHIPELAGO

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.21610/conferencearticle_58b4315256b56 ◽

2017 ◽

Author(s):

Ryo Sakamoto ◽

Satoquo Seino ◽

Hirokazu Suzaki ◽

...

Keyword(s):

Tang Dynasty ◽

National Park ◽

Survey Methods ◽

Aerial Photographs ◽

Sand Transport ◽

The Status ◽

The Tang Dynasty ◽

Coastal Changes ◽

Century Poetry ◽

Nagasaki Prefecture

A construction of breakwaters and other shoreline structures on part of a coast influences drift sand transport in the bay, and causes comprehensive topographic changes on the beach. This study investigated shoreline and coastal changes, taking as an example of Shiraragahama Beach in Miiraku on the northwestern end of Fukue Island, Nagasaki Prefecture (Kyushu, Japan). Miiraku, adjacent to Saikai National Park, appears in the revered 8th century poetry collection “Manyoshu” and served as a port for a ship taken by the Japanese envoy to China during the Tang Dynasty (618-709). Because of the recent development of breakwaters for a fishing harbor, the shore environments of this beach have changed significantly. In this study, the status of silt deposits and topographic changes on this beach arising from the construction of a harbor breakwater were evaluated by comparing aerial photographs taken in different years. Next, the changes in the shoreline visible from aerial photographs from 1947 to 2014 were analyzed. Lastly, the altitude of the beaches was measured using accurate survey methods. The following results were obtained: 1) coastal erosion made rock cliffs to fall off along the shore and deposited sand on this beach; 2) the more serious advances or retreats of the shoreline took place around shoreline structures; 3) sandbars and beach cliffs were formed.

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Spatially explicit statistical modeling of random and systematic land cover transitions in the main grassland plain of Nech Sar National Park, Ethiopia

Ecological Processes ◽

10.1186/s13717-019-0199-z ◽

2019 ◽

Vol 8 (1) ◽

Cited By ~ 2

Author(s):

Kiros Tsegay Deribew

Keyword(s):

Land Cover ◽

Land Cover Change ◽

Statistical Modeling ◽

National Park ◽

Spatial Extent ◽

Aerial Photographs ◽

Woody Vegetation ◽

Spatially Explicit ◽

Strong Signal ◽

The Past

AbstractThe main grassland plain of Nech Sar National Park (NSNP) is a federally managed protected area in Ethiopia designated to protect endemic and endangered species. However, like other national parks in Ethiopia, the park has experienced significant land cover change over the past few decades. Indeed, the livelihoods of local populations in such developing countries are entirely dependent upon natural resources and, as a result, both direct and indirect anthropogenic pressures have been placed on natural parks. While previous research has looked at land cover change in the region, these studies have not been spatially explicit and, as a result, knowledge gaps in identifying systematic transitions continue to exist. This study seeks to quantify the spatial extent and land cover change trends in NSNP, identify the strong signal transitions, and identify and quantify the location of determinants of change. To this end, the author classifies panchromatic aerial photographs in 1986, multispectral SPOT imagery in 2005, and Sentinel imagery in 2019. The spatial extent and trends of land cover change analysis between these time periods were conducted. The strong signal transitions were systematically identified and quantified. Then, the basic driving forces of the change were identified. The locations of these transitions were also identified and quantified using the spatially explicit statistical model. The analysis revealed that over the past three decades (1986–2019), nearly 52% of the study area experienced clear landscape change, out of which the net change and swap change attributed to 39% and 13%, respectively. The conversion of woody vegetation to grassland (~ 5%), subsequently grassland-to-open-overgrazed land (28.26%), and restoration of woody vegetation (0.76%) and grassland (0.72%) from riverine forest and open-overgrazed land, respectively, were found to be the fully systematic transitions whereas the rest transitions were recorded either partly systematic or random transitions. The location of these most systematic land cover transitions identified through the spatially explicit statistical modeling showed drivers due to biophysical conditions, accessibility, and urban/market expansions, coupled with successive government policies for biodiversity management, geo-politics, demographic, and socioeconomic factors. These findings provide important insights into biodiversity loss, land degradation, and ecosystem disruption. Therefore, the model for predicted probability generally suggests a 0.75 km and 0.72 km buffers which are likely to protect forest and grassland from conversion to grassland and open-overgrazed land, respectively.

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Eighty years of change: vegetation in the montane ecoregion of Jasper National Park, Alberta, Canada

Canadian Journal of Forest Research ◽

10.1139/x02-112 ◽

2002 ◽

Vol 32 (11) ◽

pp. 2010-2021 ◽

Cited By ~ 48

Author(s):

Jeanine M Rhemtulla ◽

Ronald J Hall ◽

Eric S Higgs ◽

S Ellen Macdonald

Keyword(s):

National Park ◽

Vegetation Change ◽

Fire Regime ◽

Reference Conditions ◽

Habitat Diversity ◽

Climatic Conditions ◽

Aerial Photographs ◽

Contributing Factors ◽

Jasper National Park ◽

Closed Canopy

Repeat ground photographs (taken in 1915 and 1997) from a series of topographical survey stations and repeat aerial photographs (flown in 1949 and 1991) were analysed to assess changes in vegetation composition and distribution in the montane ecoregion of Jasper National Park, in the Rocky Mountains of Alberta, Canada. A quantitative approach for assessing relative vegetation change in repeat ground photographs was developed and tested. The results indicated a shift towards late-successional vegetation types and an increase in crown closure in coniferous stands. Grasslands, shrub, juvenile forest, and open forests decreased in extent, and closed-canopy forests became more prevalent. The majority of forest stands succeeded to dominance by coniferous species. Changes in vegetation patterns were likely largely attributable to shifts in the fire regime over the last century, although climatic conditions and human activity may also have been contributing factors. Implications of observed changes include decreased habitat diversity, increased possibility of insect outbreaks, and potential for future high-intensity fire events. Results of the study increase knowledge of historical reference conditions and may help to establish restoration goals for the montane ecoregion of the park.

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The influence of the 1991/92 drought on the woody vegetation of the Kruger National Park

Koedoe ◽

10.4102/koedoe.v38i2.316 ◽

1995 ◽

Vol 38 (2) ◽

Cited By ~ 14

Author(s):

A.J. Viljoen

Keyword(s):

National Park ◽

Woody Species ◽

Aerial Photographs ◽

Woody Vegetation ◽

General Area ◽

Variable Intensity ◽

The North ◽

Olifants River ◽

Area North ◽

The Impact

All observations and data related to the impact of the 1991/92 drought on the woody vegetation, excluding the riverine vegetation of major rivers, are summarised. This includes data from a visual estimate of damage from aerial photographs, surveys on selected sites, and general observations. Despite lower rainfall, the area north of the Olifants River (excluding the far-northern part) was less affected than the area south of it, suggesting that the woody vegetation in the north is more adapted to drought. A characteristic of the drought was the localised distribution pattern and variable intensity of damage to the same species in the same general area. Information on 31 species are presented briefly. Although a large number of woody species was to some extent damaged, when the woody vegetation is considered as a whole, the influence of the drought was not very severe.

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Visible and near-infrared digital images for determination of ice velocities and surface elevation during a surge on Osbornebreen, a tidewater glacier in Svalbard

Annals of Glaciology ◽

10.3189/s026030550001226x ◽

1997 ◽

Vol 24 ◽

pp. 255-261 ◽

Cited By ~ 8

Author(s):

Cecilie Rolstad ◽

Jostein Amlien ◽

Jon-Ove Hagen ◽

Bengt Lundén

Keyword(s):

Velocity Field ◽

Near Infrared ◽

Aerial Photographs ◽

Correlation Technique ◽

Digital Elevation ◽

Compressive Flow ◽

Tidewater Glacier ◽

Extension Zone ◽

Elevation Model ◽

Cross Correlation Technique

A field of vectors showing the average velocity of the surging glacier Osbornebreen, Svalbard, was determined by comparing sequential SPOT (Système pour l’Observation de la Terre) and Landsat thematic mapper images. Crevasses which developed during the initial phase of the surge in the winter of 1986–87 were tracked using a fast Fourier chip cross-correlation technique. A digital elevation model (DEM) was developed using digital photogrammetry on aerial photographs from 1990. This new DEM was compared with a map drawn in 1966. The velocity field could be almost entirely determined with 1 month separation of the images, but only partly determined with images 1 year apart, due to changes of the crevasse pattern. The velocity field is similar to that found for Kronebreen, a continuously fast-moving tidewater glacier. No distinct zones of compressive flow were present and the data gave no evidence of a compression zone/surge front traveling downstream. The velocity field, the rapid advance of the terminus and the development of transverse crevasses in the upper accumulation area within a 6 month period may indicate that the surge developed as a zone of extension starting near the terminus and propagating quickly upstream. The crevasse pattern in the images is therefore interpreted to be the result of the extension zone traveling upstream, and, as the whole glacier starts to slide, the crevasse pattern alters according to the bedrock topography.

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A Novel Method for Feature Extraction and Classification for an Aerial Image and LiDAR Data with Genetic Algorithm

International Journal of Computer Science and Informatics ◽

10.47893/ijcsi.2012.1050 ◽

2012 ◽

pp. 264-270

Author(s):

Manjunath B. E ◽

D. G. Anand ◽

Mahant. G. Kattimani

Keyword(s):

Feature Extraction ◽

Light Detection And Ranging ◽

Aerial Image ◽

Lidar Data ◽

Light Detection ◽

Aerial Photos ◽

The Earth ◽

Digital Elevation ◽

Land Surveying ◽

Novel Method

Airborne Light Detection and Ranging (LiDAR) provides accurate height information for objects on the earth, which makes LiDAR become more and more popular in terrain and land surveying. In particular, LiDAR data offer vital and significant features for land-cover classification which is an important task in many application domains. Aerial photos with LiDAR data were processed with genetic algorithms not only for feature extraction but also for orthographical image. DSM provided by LiDAR reduced the amount of GCPs needed for the regular processing, thus the reason both efficiency and accuracy are highly improved. LiDAR is an acronym for Light Detection and Ranging, which is typically defined as an integration of three technologies into a single system, which is capable of acquiring a data to produce accurate Digital Elevation Models.

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Recent, rapid and profound changes to glacier morphology and dynamics, Juneau Icefield, Alaska

10.5194/egusphere-egu21-1539 ◽

2021 ◽

Author(s):

Bethan Davies ◽

Jacob Bendle ◽

Robert McNabb ◽

Jonathan Carrivick ◽

Christopher McNeil ◽

...

Keyword(s):

Little Ice Age ◽

Ice Age ◽

Aerial Photographs ◽

Equilibrium Line Altitude ◽

Regional Warming ◽

Geomorphological Mapping ◽

Glacier Recession ◽

Digital Elevation ◽

High Resolution Satellite Imagery ◽

Global Sea Level

The Alaskan region (comprising glaciers in Alaska, British Columbia and Yukon) contains the third largest ice volume outside of the Greenland and Antarctic ice sheets, and contributes more to global sea level rise than any other glacierised region defined by the Randolph Glacier Inventory. However, ice loss in this area is not linear, but in part controlled by glacier hypsometry as valley and outlet glaciers are at risk of becoming detached from their accumulation areas during thinning. Plateau icefields, such as Juneau Icefield in Alaska, are very sensitive to changes in Equilibrium Line Altitude (ELA) as this can result in rapidly shrinking accumulation areas. Here, we present detailed geomorphological mapping around Juneau Icefield and use this data to reconstruct the icefield during the &#8220;Little Ice Age&#8221;. We use topographic maps, archival aerial photographs, high-resolution satellite imagery and digital elevation models to map glacier lake and glacier area and volume change from the Little Ice Age to the present day (1770, 1948, 1979, 1990, 2005, 2015 and 2019 AD). Structural glaciological mapping (1979 and 2019) highlights structural and topographic controls on non-linear glacier recession.&#160; Our data shows pronounced glacier thinning and recession in response to widespread detachment of outlet glaciers from their plateau accumulation areas. Glacier detachments became common after 2005, and occurred with increasing frequency since then. Total summed rates of area change increased eightfold from 1770-1948 (-6.14 km2 a-1) to 2015-2019 (-45.23 km2 a-1). Total rates of recession were consistent from 1770 to 1990 AD, and grew increasingly rapid after 2005, in line with regional warming.

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The new Swiss Glacier Inventory SGI2016: a detailed cartographic representation of Swiss glacier extent and supraglacial debris-cover

10.5194/egusphere-egu21-5873 ◽

2021 ◽

Author(s):

Andreas Linsbauer ◽

Matthias Huss ◽

Elias Hodel ◽

Andreas Bauder ◽

Mauro Fischer ◽

...

Keyword(s):

Surface Area ◽

Swiss Alps ◽

Aerial Images ◽

Aerial Photographs ◽

Slope Aspect ◽

Relative Area ◽

Glacier Surface ◽

Glacier Inventory ◽

Digital Elevation ◽

Debris Cover

With increasing anthropogenic greenhouse gas emissions and corresponding global warming, glaciers in Switzerland are shrinking rapidly as in many mountain ranges on Earth. Repeated glacier inventories are a key task to monitor such glacier changes and provide detailed information on the extent of glaciation, and important parameters such as area, elevation range, slope, aspect etc. for a given point or a period in time. Here we present the new Swiss Glacier Inventory (SGI2016) that has been acquired based on high-resolution aerial imagery and digital elevation models in cooperation with the Federal Office of Topography (swisstopo) and Glacier Monitoring in Switzerland (GLAMOS), bringing together topological and glaciological knowhow. We define the process, workflow and required glaciological adaptations to compile a highly accurate glacier inventory based on the digital Swiss topographic landscape model (swissTLM3D).The SGI2016 provides glacier outlines (areas), supraglacial debris cover, ice divides and location points of all glaciers in Switzerland referring to the years 2013-2018, whereas most of the glacier outlines have been mapped based on aerial images acquired between 2015-2017 (75% in number and 87% in area), with the centre year 2016. The SGI2016 maps 1400 individual glacier entities with a total glacier surface area of 961 km2 (whereof 11% / 104 km2 are debris-covered) and constitutes the so far most detailed cartographic representation of glacier extent in Switzerland. Analysing the dependencies between topographic parameters and debris-cover fraction on the basis of individual glaciers reveals that short glaciers with a moderate mean slope and glaciers with a low median elevation tend to have high debris fractions. A change assessment between the SGI1973 and SGI2016 based on individual glacier entities affirms the largest relative area changes for small glaciers and for low-elevation glaciers, whereas the largest glaciers show small relative area changes, though large absolute changes. The analysis further indicates a tendency for glaciers with a high share of supraglacial debris to show larger relative area changes.Despite of an observed strong glacier volume loss between 2010 and 2016, the total glacier surface area of the SGI2016 is somewhat larger than reported in the last Swiss glacier inventory SGI2010. Even though both inventories were created based on swisstopo aerial photographs, the additional data, tools, resources and methodologies used by the professional cartographers digitizing glacier outlines in 3D for the SGI2016, are able to explain the counter-intuitive difference between SGI2010 and SGI2016. A direct comparison of these two datasets is thus not meaningful, but an experiment where a representative glacier sample of the SGI2010 was re-assessed based on the approaches of the SGI2016 led to an upscaled total glacier surface area of 1010 km2 for the Swiss Alps around 2010. This indicates an area loss of 49 km2 between the two last Swiss glacier inventories. As swisstopo data products are and will be regularly updated, the SGI2016 is the first step towards a consistent and accurate data product of repeated glacier inventories in six-year time intervals that promises a high comparability for individual glaciers and glacier samples.

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