High-resolution Aerial Photographs Research Articles

Mapping Topographic and Vegetation Bioshield Mass Recovery along the Shoreline Using Kite Aerial Photography

High-resolution aerial photographs coupled with infra-red images are useful for creating terrain models and vegetation mapping. Kite Aerial Photography (KAP) is very reliable for acquiring low altitude aerial images for low-cost and high spatial resolution. This study examined post-tsunami relief in different coastal ecosystems (i.e., mangrove, coastal shrub and sand dune vegetation) in terms of vegetation bioshield mass and sea level rise scenarios. A KAP platform was created using two light-weight automatic cameras with dual bandpass Red-NIR filters, Picavet stabilizing rig, GPS tracker and a Parafoil kite. The high resolution KAP images were processed to build mosaic images, orthorectified and geo-referenced DEMS using structure-from-motion (SfM) and remote sensing software (Agisoft PhotoScan and ENVI respectively). KAP has been utilized for coastal mapping under two scenarios: (i) Normalized Difference Vegetation Index (NDVI) for vegetation bioshield mass estimation (ii) Digital Elevation Model for sea level rise. We produced 1:1500 scale orthorectified maps of coastal habitats representing coastal shrubs, mangroves and sand dune vegetation. The image processing produced a point cloud with an average density of 35 points/m2; a DEM with 17 cm resolution; and an orthophoto mosaic with an average resolution of 4.3 cm. The preliminary results of this case study demonstrate the application of KAP for costal habitat vulnerability assessment with an advantage of KAP as low-cost, high spatial/temporal resolution, and limited regulation. In conclusion, KAP has a great potential to bridge science with high spatial/temporal resolution in-situ data for environmental monitoring, where our researchers can utilize the data within a low-cost budget.In the future, comparisons of mapping data from different techniques can be improved with a KAP platform. Keywords: Kite Aerial Photography, Coastal habitat, Keyword, NDVI, Structure-from- motion

Accuracy assessment of cadastral maps using high resolution aerial photos

A cadastral map is a map that shows the boundaries and ownership of land parcels. Some cadastral maps show additional details, such as survey district names, unique identifying numbers for parcels, certificate of title numbers, positions of existing structures, section or lot numbers and their respective areas, adjoining and adjacent street names, selected boundary dimensions and references to prior maps. In Iraq / Baghdad Governorate, the main problem is that the cadastral maps are georeferenced to a local geodetic datum known as Clark 1880 while the widely used reference system for navigation purpose (GPS and GNSS) and uses Word Geodetic System 1984 (WGS84) as a base reference datum. The objective of this paper is to produce a cadastral map with scale 1:500 (metric scale) by using aerial photographs 2009 with high ground spatial resolution 10 cm reference WGS84 system. The accuracy assessment for the cadastral maps updating approach to urban large scale cadastral maps (1:500-1:1000) was ± 0.115 meters; which complies with the American Social for Photogrammetry and Remote Sensing Standards (ASPRS).

Change Detection of Plant Communities of High Moor in Kushiro wetland using Bi-temporal high spatial resolution aerial photographs

Change Detection of Plant Communities of High Moor in Kushiro wetland using Bi-temporal high spatial resolution aerial photographs

Spatial pattern analysis and identification type of open green space in Yogyakarta city

Open green Space is a spatial plan model aiming to maintain the quality of the environment. Nowadays, the number and distribution of Open green Space have decreased, particularly in urban areas. Such decline is due to many reasons, one of which is land conversion caused by social activities. This research aimed to analyse the distribution pattern and identify the type of Open green Space in Yogyakarta City. The method in this study using moran's I Index approach, GIS and direct field review. The results showed that the Open green Space was clustered with Moran's Index of 0,074594. Validation with field check indicated that there was an absence of even, thorough, and most recent Open green Space identification. Visual detection using high-resolution satellite images and aerial photos affirmed that many open green spaces had not been inventoried, justifying the need for data update in Yogyakarta City. The identification process resulted in different types of Open green Space, but the most widely distributed ones in Yogyakarta City were in the forms of Private yard, Office park, Green belt, and City Parks.

Mapeamento do uso e da cobertura da terra na Ilha de Santa Catarina, Brasil, com base em imagem de alta resolução espacial

Este trabalho apresenta um mapeamento do uso e cobertura da terra da Ilha de Santa Catarina com base em aerofotografias de alta resolução espacial e na vetorização da Restituição Aerofotogramétrica do Instituto de Planejamento Urbano de Florianópolis (IPUF) na escala 1:2.000. O método de interpretação das classes de mapeamento foi efetuado através da análise e interpretação visual de um mosaico aerofotogramétrico e o sistema de mapeamento foi organizado em 17 classes. Os resultados obtidos revelam o predomínio das classes de vegetação e do tecido urbano. As análises revelaram uma urbanização com densidade pontual e a presença de núcleos densos somente nas antigas áreas de povoamento, nas que abrigam grandes empreendimentos imobiliários ou de planejamento urbano.

Grassland connectivity in fragmented agricultural landscapes of the north-central United States

In the prairies of North America, remnant native grasslands are threatened by continuing agricultural extensification. Fragmentation of the remaining grassland isolates patches and limits the potential for dispersal of native species. We explored these impacts by analyzing the spatial pattern of native grassland habitats in the Prairie Coteau region of eastern South Dakota and western Minnesota, USA. Undisturbed grasslands were mapped using a GIS database of land use history combined with manual interpretation of high-resolution aerial photographs. Network analysis based on graph theory was used to examine how connectivity changed depending on the potential movement distances of organisms and to identify important patches that made large contributions to connectivity throughout the broader network. Interpatch movement was assessed using Euclidian distance as well as cost-weighted distance that assigned lower movement cost to grasslands than to human-modified land cover types. Much of the undisturbed grassland was concentrated in a single large cluster, which was connected to other habitat concentrations via corridors of “stepping stone” patches. A small number of “keystone patches”, whose loss would have a disproportionately large effect on overall connectivity, were also identified. The locations of the major corridors were relatively consistent across different movement distances. Information about patch-level importance for overall network connectivity should be taken into account when prioritizing conservation and restoration. Future studies can build on this research by conducting more detailed assessments focused on particular species of concern and portions of the study area where connectivity is most limited.

Building extraction for 3D city modelling using airborne laser scanning data and high-resolution aerial photo

Light detection and ranging (LiDAR) technology has become a standard tool for three-dimensional mapping because it offers fast rate of data acquisition with unprecedented level of accuracy. This study presents an approach to accurately extract and model building in three-dimensional space from airborne laser scanning data acquired over Universiti Putra Malaysia in 2015. First, the point cloud was classified into ground and non-ground xyz points. The ground points was used to generate digital terrain model (DTM) while digital surface model (DSM) was produced from the entire point cloud. From DSM and DTM, we obtained normalise DSM (nDSM) representing the height of features above the terrain surface. Thereafter, the DSM, DTM, nDSM, laser intensity image and orthophoto were combined as a single data file by layer stacking. After integrating the data, it was segmented into image objects using Object Based Image Analysis (OBIA) and subsequently, the resulting image object classified into four land cover classes: building, road, waterbody and pavement. Assessment of the classification accuracy produced overall accuracy and Kappa coefficient of 94.02% and 0.88 respectively. Then the extracted building footprints from the building class were further processed to generate 3D model. The model provides 3D visual perception of the spatial pattern of the buildings which is useful for simulating disaster scenario for emergency management.

Towards a Transferable UAV-Based Framework for River Hydromorphological Characterization.

The multiple protocols that have been developed to characterize river hydromorphology, partly in response to legislative drivers such as the European Union Water Framework Directive (EU WFD), make the comparison of results obtained in different countries challenging. Recent studies have analyzed the comparability of existing methods, with remote sensing based approaches being proposed as a potential means of harmonizing hydromorphological characterization protocols. However, the resolution achieved by remote sensing products may not be sufficient to assess some of the key hydromorphological features that are required to allow an accurate characterization. Methodologies based on high resolution aerial photography taken from Unmanned Aerial Vehicles (UAVs) have been proposed by several authors as potential approaches to overcome these limitations. Here, we explore the applicability of an existing UAV based framework for hydromorphological characterization to three different fluvial settings representing some of the distinct ecoregions defined by the WFD geographical intercalibration groups (GIGs). The framework is based on the automated recognition of hydromorphological features via tested and validated Artificial Neural Networks (ANNs). Results show that the framework is transferable to the Central-Baltic and Mediterranean GIGs with accuracies in feature identification above 70%. Accuracies of 50% are achieved when the framework is implemented in the Very Large Rivers GIG. The framework successfully identified vegetation, deep water, shallow water, riffles, side bars and shadows for the majority of the reaches. However, further algorithm development is required to ensure a wider range of features (e.g., chutes, structures and erosion) are accurately identified. This study also highlights the need to develop an objective and fit for purpose hydromorphological characterization framework to be adopted within all EU member states to facilitate comparison of results.

Impacts of Urbanization on Vegetation Phenology over the Past Three Decades in Shanghai, China

Vegetation phenology manifests the rhythm of annual plant life activities. It has been extensively studied in natural ecosystems. However, major knowledge gaps still exist in understanding the impacts of urbanization on vegetation phenology. This study addresses two questions to fill the knowledge gaps: (1) How does vegetation phenology vary spatially and temporally along a rural-to-urban transect in Shanghai, China, over the past three decades? (2) How do landscape composition and configuration affect those variations of vegetation phenology? To answer these questions, 30 m × 30 m mean vegetation phenology metrics, including the start of growing season (SOS), end of growing season (EOS), and length of growing season (LOS), were derived for urban vegetation using dense stacks of enhanced vegetation index (EVI) time series from images collected by Landsat 5–8 satellites from 1984 to 2015. Landscape pattern metrics were calculated using high spatial resolution aerial photos. We then used Pearson correlation analysis to quantify the associations between phenology patterns and landscape metrics. We found that vegetation in urban centers experienced advances of SOS for 5–10 days and delays of EOS for 5–11 days compared with those located in the surrounding rural areas. Additionally, we observed strong positive correlations between landscape composition (percentage of landscape area) of developed land and LOS of urban vegetation. We also found that the landscape configuration of local land cover types, especially patch density and edge density, was significantly correlated with the spatial patterns of vegetation phenology. These results demonstrate that vegetation phenology in the urban area is significantly different from its rural surroundings. These findings have implications for urban environmental management, ranging from biodiversity protection to public health risk reduction.

Photo Interpretation and GIS as a support tool for Archaeology

This work presents photo interpretation integration techniques of high resolution aerial photographs and satellite images. Through the use of this methodology, it is possible to identify Dolmens located in the Center Alentejo - Portugal, and recover archaeological information. From the observation of dolmens it was perceived the shape of these objects visualised in vertical images. The use of Remote Sensing techniques in conjunction with ArcGIS allowed to confirm and to know the interpretation keys of these monuments. This feature keys allow to identify and recognise sites already identified as well as new buildings.

661 Comparison of high-resolution aerial photography with manual field collection in assessing the control of red cedar using goats

661 Comparison of high-resolution aerial photography with manual field collection in assessing the control of red cedar using goats

SHORELINE CHANGE DETECTION AND COASTAL EROSION MONITORING USING DIGITAL PROCESSING OF A TIME SERIES OF HIGH SPATIAL RESOLUTION REMOTE SENSING DATA

The long term change of the shoreline is a phenomenon, which is factored in the design of construction projects along the coastal zone. This study presents a methodology that aims to quantify the shoreline displacement rate. The described methodology involves the interpretation of different remote sensing data types, which make up a quite dense time series of representations for the coastline spanning from 1987 to 2012. The representation of the shoreline is based on geometrically corrected (ortho-rectified), historical, analogue, panchromatic, high resolution aerial photos of the area (1987, 1996) and latest generation, digital, multispectral, high resolution satellite images (2000, 2008, 2012). In all cases the images were digitally processed and optically optimized in order to produce a highly accurate representation of the shoreline in each time period. All the data were imported in a Geographic Information System platform, where they were subjected to comparison and geo-statistical analysis. A large number of sections perpendicular to the coast (every 100 meters) was drawn and the relative motion of the coastline was calculated for each of them. The average rate of the calculated erosion is in the order of 24mm/year whilst extreme rates of 1m/year were also observed in specific positions.

Analysis of forest structural complexity using airborne LiDAR data and aerial photography in a mixed conifer–broadleaf forest in northern Japan

Determining forest structural complexity, i.e., a measure of the number of different attributes of a forest and the relative abundance of each attribute, is important for forest management and conservation. In this study, we examined the structural complexity of mixed conifer–broadleaf forests by integrating multiple forest structural attributes derived from airborne LiDAR data and aerial photography. We sampled 76 plots from an unmanaged mixed conifer–broadleaf forest reserve in northern Japan. Plot-level metrics were computed for all plots using both field and remote sensing data to assess their ability to capture the vertical and horizontal variations of forest structure. A multivariate set of forest structural attributes that included three LiDAR metrics (95th percentile canopy height, canopy density and surface area ratio) and one image metric (proportion of broadleaf cover), was used to classify forest structure into structural complexity classes. Our results revealed significant correlation between field and remote sensing metrics, indicating that these two sets of measurements captured similar patterns of structure in mixed conifer–broadleaf forests. Further, cluster analysis identified six forest structural complexity classes including two low-complexity classes and four high-complexity classes that were distributed in different elevation ranges. In this study, we could reliably analyze the structural complexity of mixed conifer–broadleaf forests using a simple and easy to calculate set of forest structural attributes derived from airborne LiDAR data and high-resolution aerial photography. This study provides a good example of the use of airborne LiDAR data sets for wider purposes in forest ecology as well as in forest management.

Impervious Surface Detection in Semi-Urban Environment Using Lidar Data and High Resolution Aerial Photographs

Land use information plays a vital role in effective management of natural resources in any country. It helps manage water, soil, nutrients and plants, animals and provides relationships between land use dynamics, economics and social conditions both in urban and rural areas. The land use and land cover mapping is always a dynamic issue in every country because of the dynamic nature of the land use. Knowledge of land use change patterns has important implications in sustainable development and sustainable environmental management. Impervious surfaces are generally defined as any anthropogenic materials that water cannot infiltrate. Increase in impervious land in urban area is causing high accumulation of storm water during the wet season and causing widespread flooding.This research develops an improved method for impervious land use detection using object–oriented classification system. Although pixel-based approaches have certain strong merits and remain in widespread use, operating at the spatial scale of the pixel can have major drawbacks. Foremost among these is that a pixel’s spatial extent may not match the extent of the land cover feature of interest. That is pixel’s spatial extent may not match the extent of the land cover feature of interest-the problem of mixed pixels may lead to misclassification. Also, when object of interest is considerably larger than the pixel size such as VHR images, urban area comparisons show that the object oriented approach is superior to pixel based approach in terms of accuracy. Object Oriented classification technique is used to separate urban and non-urban features. Negative values of NDVI helped to classify impervious area. Non elevated impervious surfaces are well addressed by NDVI threshold. LiDAR data is used to separate elevated impervious area. By and large, the research shows that impervious land in urban area can be detected using the developed technique with satisfactory accuracy.

Angola Coastal Mapping and Tactics for Oil Spill Response

ABSTRACT The Angolan oil and gas industry workgroup (ACEPA-Associação das Companhias de Exploração e Produção de Angola) continues to collaborate in the development and completion of oil spill response initiatives as responsible operators and committed participants in the IMO-IPIECA Global Initiative for West, Central and Southern Africa (GI WACAF). Between 2012–2015, a comprehensive program of oil spill response planning, geodatabase development, mapping, and guides were completed for the entire coast of Angola. Low altitude aerial video surveys that combine oblique imagery and a verbal commentary record were recorded as the foundation for mapping coastal sensitivities, ESI characterization, shore zone and backshore operational definition, and shoreline segmentation. Other information added to the coastal geodatabase includes operational and logistical considerations such as land access and boat launch locations, proposed sites for staging, holding of temporary wastes, industrial and human use (fishing, recreational), and nearshore access constraints. A key aspect of the shoreline mapping effort was to build the information into a stand-alone pre-shoreline cleanup assessment technique (SCAT)-database that provides layered information for each of the 1999 shoreline segments. Digital video and high-resolution oblique aerial photos for 2400 km of coastline are geo-referenced and integrated into the GIS system with viewer software that allows the user to “fly” the shoreline. Shoreline attributes for biological, socioeconomic, and human use were used to rank 117 sensitive sites. The 45 highest priority sensitive sites were surveyed and detailed geographic response plans (GRPs) for site protection strategies and tactics were compiled into two atlases. The comprehensive coastal characterization, segmentation, and priority site protection plans provide the Angola government and oil industry with spill preparedness tools that are world-class.

Recognition and mapping of lacustrine relict coastal features using high resolution aerial photographs and LiDAR data

Shallow lakes in semiarid regions experience frequent water level fluctuations. Each long-lasting episode of water-level lowering leaves behind abandoned littoral forms and deposits whose identification and mapping is hampered by their smooth relief. Given the difficulty of recognising these possible relict forms using traditional geomorphological techniques, two sources of information were employed in the present work: high resolution (1:15,000) aerial photographs and a digital terrain model (DTM) generated from LiDAR data. The improved definition of surface elevation enhanced the quality of geomorphological mapping as well as the accurate delineation of subtle geoforms. The method was applied to Gallocanta Lake, a highly fluctuating shallow lake 14 km2 in area and less than 3 m deep located in a mountainous semiarid area of NE Spain. As a result, a sequence of relict coastal features (RCF) with high lateral continuity has been identified around the lakebed. These include well-preserved spits with recurved hooks, counter-spits, bays closed by barrier islands, beach ridges, deltas and cliffs. The highly precise LiDAR-derived topographic maps suggest a much greater extension of the lacustrine environment during the Late Pleistocene, reaching at least 51 km2 of water surface and about 13 m of depth above the present lake bottom. The method presented in this paper generates very detailed palaeogeographical maps that are particularly useful for reconstructing lake changes in semiarid environments as a function of climate change.

A multidisciplinary approach to digital mapping of dinosaurian tracksites in the Lower Cretaceous (Valanginian-Barremian) Broome Sandstone of the Dampier Peninsula, Western Australia.

The abundant dinosaurian tracksites of the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone of the Dampier Peninsula, Western Australia, form an important part of the West Kimberley National Heritage Place. Previous attempts to document these tracksites using traditional mapping techniques (e.g., surface overlays, transects and gridlines combined with conventional photography) have been hindered by the non-trivial challenges associated with working in this area, including, but not limited to: (1) the remoteness of many of the tracksites; (2) the occurrence of the majority of the tracksites in the intertidal zone; (3) the size and complexity of many of the tracksites, with some extending over several square kilometres. Using the historically significant and well-known dinosaurian tracksites at Minyirr (Gantheaume Point), we show how these issues can be overcome through the use of an integrated array of remote sensing tools. A combination of high-resolution aerial photography with both manned and unmanned aircraft, airborne and handheld high-resolution lidar imaging and handheld photography enabled the collection of large amounts of digital data from which 3D models of the tracksites at varying resolutions were constructed. The acquired data encompasses a very broad scale, from the sub-millimetre level that details individual tracks, to the multiple-kilometre level, which encompasses discontinuous tracksite exposures and large swathes of coastline. The former are useful for detailed ichnological work, while the latter are being employed to better understand the stratigraphic and temporal relationship between tracksites in a broader geological and palaeoecological context. These approaches and the data they can generate now provide a means through which digital conservation and temporal monitoring of the Dampier Peninsula’s dinosaurian tracksites can occur. As plans for the on-going management of the tracks in this area progress, analysis of the 3D data and 3D visualization will also likely provide an important means through which the broader public can experience these spectacular National Heritage listed landscapes.

The spatial organization of ecosystem services in river‐floodplains

AbstractRiver‐floodplains are hotspots for many ecosystem services (ES), and thus, understanding how these services are spatially organized along river systems is essential. General principles from river‐floodplain ecology may provide guidance for understanding these spatial patterns, yet such concepts have rarely been incorporated into spatial assessments of ES. Using a lens of riverine concepts, we contrasted how floodplain ES capacity and diversity (orchard production, forage production, carbon storage, paddle route quality, fish capacity) vary with longitudinal river‐floodplain position. High spatial resolution aerial photography (2006) facilitated detection of floodplain features contributing to the production of ES. We also determined how river reach types are linked to production of ES. We found that ES capacity varied considerably with longitudinal position and reach type. Agricultural capacity was concentrated in lower reaches, high‐quality paddle routes in middle‐lower reaches, and fish capacity and carbon storage in upper reaches. Furthermore, the highest diversity of ES was concentrated in the lowland floodplain reaches. Our results suggest river‐floodplain concepts can improve spatial assessments of ES, increase our understanding of the relationships among biological features and ES, and thus help us better manage some of the key ES trade‐offs.

Drones for justice: inclusive technology and river-related action research along the Kapuas

Abstract. This article discusses the potential of using drones for community-based counter-mapping. Drawing on action research conducted along the Kapuas River in West Kalimantan, Indonesia, we describe how drones were used for political interventions against land grabs by palm oil and mining companies. We share our experience of how to use drones to generate high-resolution aerial photographs that can be stitched together to create GPS-referenced maps that can support local communities' land rights. We argue that do-it-yourself drones can reduce the costs of and expertise hitherto associated with counter-mapping. While this creates the potential for a more inclusive technology, the question of who controls the technology and to what end is a political one. We conclude by comparing two interventions and discuss why the drone technology could be appropriated by local activists in one case but not in the other.

Monitoring of wetland inundation dynamics in the Delmarva Peninsula using Landsat time-series imagery from 1985 to 2011

Wetlands provide important ecosystem services, the provision of which is largely controlled by fluctuations in inundation and soil saturation. Inundation is highly dynamic and can vary substantially through time in response to multiple drivers, including precipitation and evapotranspiration. This research focused on developing a practical and effective framework for regional, long-term monitoring of wetland inundation dynamics using airborne LiDAR intensity data (Lang et al., 2013) and Landsat time-series imagery. Subpixel water fraction (SWF) maps indicating the percent of surface water within each 30-m pixel were generated on an annual basis over the entire Delmarva Peninsula on the East Coast of the United States from 1985 to 2011. Comprehensive accuracy assessments of the SWF maps were conducted using historical high-resolution aerial photography to determine the reference condition. The assessment resulted in an estimated root mean square error (RMSE) of 7.78% for the sample of open water areas (mean SWF was ~40% for this region of the map). Moreover, a separate accuracy assessment targeting inundation in wetlands (i.e. presence or absence of water) yielded an overall accuracy of 93%. Accuracies derived indicated that Landsat data can be calibrated to accurately extract long-term water information at the regional scale. Characteristics of inundation were examined with respect to different wetland types defined by water regime and dominant vegetation types, as well as different physical drivers. Results showed that tidal wetlands typically exhibited more intensive inundation than nontidal wetlands, and a higher degree of inundation was associated with emergent wetlands compared to wetland areas dominated by woody vegetation. Analysis of change drivers revealed that tide exerted a statistically significant influence on coastal inundation with r2 values of 32–36% and p<0.01, whereas inundation changes in inland wetland areas were in part driven by precipitation with r2 values of 25–34% and p<0.08. Because an up-to-date archive of Landsat imagery is globally available and LiDAR data are becoming increasingly more affordable, the developed framework can be easily implemented to generate a continuous inundation record in many regions of the globe to assist in ongoing and future studies focused on wetland hydrology and wetland management.