Automatic Extraction of Grasses and Individual Trees in Urban Areas Based on Airborne Hyperspectral and LiDAR Data

Urban vegetation extraction is very important for urban biodiversity assessment and protection. However, due to the diversity of vegetation types and vertical structure, it is still challenging to extract vertical information of urban vegetation accurately with single remotely sensed data. Airborne light detection and ranging (LiDAR) can provide elevation information with high-precision, whereas hyperspectral data can provide abundant spectral information on ground objects. The complementary advantages of LiDAR and hyperspectral data could extract urban vegetation much more accurately. Therefore, a three-dimensional (3D) vegetation extraction workflow is proposed to extract urban grasses and trees at individual tree level in urban areas using airborne LiDAR and hyperspectral data. The specific steps are as follows: (1) airborne hyperspectral and LiDAR data were processed to extract spectral and elevation parameters, (2) random forest classification method and object-based classification method were used to extract the two-dimensional distribution map of urban vegetation, (3) individual tree segmentation was conducted on a canopy height model (CHM) and point cloud data separately to obtain three-dimensional characteristics of urban trees, and (4) the spatial distribution of urban vegetation and the individual tree delineation were assessed by validation samples and manual delineation results. The results showed that (1) both the random forest classification method and object-based classification method could extract urban vegetation accurately, with accuracies above 99%; (2) the watershed segmentation method based on the CHM could extract individual trees correctly, except for the small trees and the large tree groups; and (3) the individual tree segmentation based on point cloud data could delineate individual trees in three-dimensional space, which is much better than CHM segmentation as it can preserve the understory trees. All the results suggest that two- and three-dimensional urban vegetation extraction could play a significant role in spatial layout optimization and scientific management of urban vegetation.

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Research on Generation Rules of Chest Width Point Curve Based on 3D Female Mannequin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.796.513 ◽

2013 ◽

Vol 796 ◽

pp. 513-518

Author(s):

Rong Jin ◽

Bing Fei Gu ◽

Guo Lian Liu

Keyword(s):

Point Cloud ◽

Three Dimensional ◽

Upper Body ◽

Secondary Development ◽

Linear Regression Method ◽

Point Cloud Data ◽

Body Type ◽

Cloud Data ◽

Engineering Software ◽

The Individual

In this paper 110 female undergraduates in Soochow University are measured by using 3D non-contact measurement system and manual measurement. 3D point cloud data of human body is taken as research objects by using anti-engineering software, and secondary development of point cloud data is done on the basis of optimizing point cloud data. In accordance with the definition of the human chest width points and other feature points, and in the operability of the three-dimensional point cloud data, the width, thickness, and length dimensions of the curve through the chest width point are measured. Classification of body type is done by choosing the ratio values as classification index which is the ratio between thickness and width of the curve. The generation rules of the chest curve are determined for each type by using linear regression method. Human arm model could be established by the computer automatically. Thereby the individual model of the female upper body mannequin modeling can be improved effectively.

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Assyrian sacred trees in the Brooklyn Museum

Iraq ◽

10.1017/s0021088900002874 ◽

1994 ◽

Vol 56 ◽

pp. 123-133 ◽

Cited By ~ 6

Author(s):

Pauline Albenda

Keyword(s):

Present Author ◽

Ninth Century ◽

Palm Tree ◽

The West ◽

Individual Tree ◽

Sacred Tree ◽

The Individual ◽

Individual Trees ◽

Brooklyn Museum ◽

Tree Type

The Brooklyn Museum houses twelve stone slabs with carved decoration from the Northwest Palace of Ashurnasirpal II. The motif of a stylized tree — the so-called Sacred Tree (see Figs. 1, 4, 6) — appears on seven of those slabs which come from rooms F, I, L, S, T of the ninth century palace at Nimrud. These tree renderings are representative of the sacred tree-type found in ten rooms of the royal residence and the west wing. Approximately 96 sacred trees, in two-register arrangement, appeared on the pictorial decorations in room I; the same motif occurred about 75 times in one-register arrangement on the reliefs of the other rooms. The abundance of the sacred tree motif on the wall decorations of the Northwest Palace attests to the significance of this plant. Its design deserves investigation; in Layard's words, “the tree, evidently a sacred symbol, is elaborately and tastefully formed.”In his study of the Ashurnasirpal II reliefs in American collections, Stearns did not attempt to list the sacred trees, because “variations in the sacred tree occur only in minor details,” and “the tree in itself is rarely useful in identifying the location of the reliefs.” These statements make clear Stearns' belief that the sacred trees were nearly alike. Other scholars, notably Weidner and Reade, have pointed out that on a number of slabs now in American and European museums are carvings of matching half trees, therefore indicating that when paired, these trees belonged to adjoining slabs originally. In trying to match half trees, one finds that individual sacred trees do differ in the rendering of specific details. Bleibtreu, in her analysis of the sacred tree-type, lists three variants of the flower found on the palmette-garland framing the individual tree on three sides. The present author, after examining the sacred trees carved on the slabs in The Brooklyn Museum, concludes that the design of the tree-type is more varied than heretofore presumed, and that its construction is more complex than indicated in previous descriptions of the subjects. An analysis of the Assyrian sacred tree-type may lead to possible conclusions regarding its intended image: a stylized palm tree, a cult object, an emblem of vegetation or “tree of life”, an imperial symbol, or a combination of those forms. In addition, one may consider to what extent the rendering of individual trees was the consequence of artistic inventiveness.

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LiDAR-Based Wildfire Prevention in WUI: The Automatic Detection, Measurement and Evaluation of Forest Fuels

Forests ◽

10.3390/f10020148 ◽

2019 ◽

Vol 10 (2) ◽

pp. 148 ◽

Cited By ~ 4

Author(s):

Marta Fernández-Álvarez ◽

Julia Armesto ◽

Juan Picos

Keyword(s):

Point Clouds ◽

Individual Tree ◽

Forest Fuels ◽

Gis Tools ◽

Biomass Management ◽

Measurement And Evaluation ◽

The Individual ◽

Individual Trees ◽

Height Model

This paper describes a methodology using LiDAR point clouds with an ultra-high resolution in the characterization of forest fuels for further wildfire prevention and management. Biomass management strips were defined in three case studies using a particular Spanish framework. The data were acquired through a UAV platform. The proposed methodology allows for the detection, measurement and characterization of individual trees, as well as the analysis of shrubs. The individual tree segmentation process employed a canopy height model, and shrub cover LiDAR-derived models were used to characterize the vegetation in the strips. This way, the verification of the geometric legal restrictions was performed automatically and objectively using decision trees and GIS tools. As a result, priority areas, where wildfire prevention efforts should be concentrated in order to control wildfires, can be identified.

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A Classification-Segmentation Framework for the Detection of Individual Trees in Dense MMS Point Cloud Data Acquired in Urban Areas

Remote Sensing ◽

10.3390/rs9030277 ◽

2017 ◽

Vol 9 (3) ◽

pp. 277 ◽

Cited By ~ 29

Author(s):

Martin Weinmann ◽

Michael Weinmann ◽

Clément Mallet ◽

Mathieu Brédif

Keyword(s):

Urban Areas ◽

Point Cloud ◽

Point Cloud Data ◽

Cloud Data ◽

Segmentation Framework ◽

Individual Trees

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Evaluation of Different Pooling Methods to Establish a Multi-Century δ18O Chronology for Paleoclimate Reconstruction

Geosciences ◽

10.3390/geosciences9060270 ◽

2019 ◽

Vol 9 (6) ◽

pp. 270 ◽

Cited By ~ 3

Author(s):

Zeynab Foroozan ◽

Jussi Grießinger ◽

Kambiz Pourtahmasi ◽

Achim Bräuning

Keyword(s):

Stable Isotope ◽

Tree Rings ◽

High Frequency ◽

Signal Amplitude ◽

Test Material ◽

Northern Iran ◽

Individual Tree ◽

Cost Efficient ◽

The Individual ◽

Individual Trees

To develop multi-century stable isotope chronologies from tree rings, pooling techniques are applied to reduce laboratory costs and time. However, pooling of wood samples from different trees may have adverse effects on the signal amplitude in the final isotope chronology. We tested different pooling approaches to identify the method that is most cost-efficient, without compromising the ability of the final chronology to reflect long-term climate variability as well as climatic extreme years. As test material, we used δ18O data from juniper trees (Juniperus polycarpus) from Northern Iran. We compared inter-tree and shifted 5-year blocks serial pooling of stable isotope series from 5 individual trees and addition of one single series to a shifted serial pooled chronology. The inter-tree pooled chronology showed the strongest climate sensitivity and most synchronous δ18O variations with the individual tree ring analyses, while the shifted block chronologies showed a marked decline in high-frequency signals and no correlations with climate variables of the growth year. Combinations of block-pooled and single isotope series compensated the high-frequency decline but added tree-individual climatic signals. Therefore, we recommend pooling calendar synchronous tree rings from individual trees as a viable alternative to individual-tree isotope measurements for robust paleoclimate reconstructions.

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Deriving Individual-Tree Biomass from Effective Crown Data Generated by Terrestrial Laser Scanning

Remote Sensing ◽

10.3390/rs11232793 ◽

2019 ◽

Vol 11 (23) ◽

pp. 2793

Author(s):

Yujie Zheng ◽

Weiwei Jia ◽

Qiang Wang ◽

Xu Huang

Keyword(s):

Laser Scanning ◽

Three Dimensional ◽

Terrestrial Laser Scanning ◽

Tree Height ◽

Biomass Estimation ◽

Tree Biomass ◽

Crown Height ◽

Individual Tree ◽

Cloud Data ◽

Biomass Equations

Biomass reflects the state of forest management and is critical for assessing forest benefits and carbon storage. The effective crown is the region above the lower limit of the forest crown that includes the maximum vertical distribution density of branches and leaves; this component plays an important role in tree growth. Adding the effective crown to biomass equations can enhance the accuracy of the derived biomass. Six sample plots in a larch plantation (ranging in area from 0.06 ha to 0.12 ha and in number of trees from 63 to 96) at the Mengjiagang forest farm in Huanan County, Jiamusi City, Heilongjiang Province, China, were analyzed in this study. Terrestrial laser scanning (TLS) was used to obtain three-dimensional point cloud data on the trees, from which crown parameters at different heights were extracted. These parameters were used to determine the position of the effective crown. Moreover, effective crown parameters were added to biomass equations with tree height as the sole variable to improve the accuracy of the derived individual-tree biomass estimates. The results showed that the minimum crown contact height was very similar to the effective crown height, and an increase in model accuracy was apparent (with R a 2 increasing from 0.846 to 0.910 and root-mean-square error (RMSE) decreasing from 0.372 kg to 0.286 kg). The optimal model for deriving biomass included tree height, crown length from minimum contact height, crown height from minimum contact height, and crown surface area from minimum contact height. The novelty of the article is that it improves the fit of individual-tree biomass models by adding crown-related variables and investigates how the accuracy of biomass estimation can be enhanced by using remote sensing methods without obtaining diameter at breast height.

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MANAGEMENT OF INDIVIDUAL TREE DIAMETER GROWTH AND IMPLICATIONS FOR PRUNING FOR BRAZILIAN Eucalyptus grandis Hill ex Maiden

FLORESTA ◽

10.5380/rf.v36i3.7519 ◽

2006 ◽

Vol 36 (3) ◽

Cited By ~ 8

Author(s):

Leif Nutto ◽

Peter Spathelf ◽

Irene Seling

Keyword(s):

Eucalyptus Grandis ◽

Rotation Period ◽

Coefficient Of Determination ◽

Individual Tree ◽

Rotation Periods ◽

Crown Cover ◽

Short Rotation ◽

Crown Width ◽

The Individual ◽

Individual Trees

In the present work a thinning program and a model describing dynamic of crown base recession for Eucalyptus grandis was established on an individual tree basis. Therefore, 485 trees were measured on temporary plots in forests of the companies Klabin Riocell (Guaíba), Todeschini (Cachoeira do Sul), the Federal University of Santa Maria and Aracruz Company, located in Rio Grande do Sul, Espirito Santo and Bahia, Brazil. A straight relationship between crown width and diameter at breast height (DBH) was found by using regression analysis. The equation obtained was crown width = e0.504+0.0307* DBH, with a coefficient of determination of 0.78 and a standard error of 0.034. With this equation the standing space of the individual trees was calculated over the whole rotation period, taking into account a crown cover of 70 %. Therefore the number of trees which can be grown on a hectare was derived for different variants of management systems aiming to produce eucalypt sawlogs in short rotation periods. Beside this a multivariate model describing height of crown base as a function of DBH and total height was found. Based upon this model the dynamics of crown base recession for different site qualities and thinning regimes are described, giving advice for time and intensity of green pruning.

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An Equation for Estimating Total Volume of Both Stands and Single Trees of Black Spruce

The Forestry Chronicle ◽

10.5558/tfc59026-1 ◽

1983 ◽

Vol 59 (1) ◽

pp. 26-29 ◽

Cited By ~ 1

Author(s):

F. Evert

Keyword(s):

Picea Mariana ◽

Black Spruce ◽

Direct Reference ◽

Individual Tree ◽

Stand Volume ◽

Volume Equation ◽

The Individual ◽

Individual Trees

A stand volume equation is presented for black spruce (Picea mariana (Mill.)B.S.P.), based on a sample of 785 felled trees. To ensure that the equation will provide accurate estimates of the volume of both variously stocked stands and of individual trees, stand volume was expressed as the sum of individual tree volumes without direct reference to the size of the area that the trees occupy. The equation will reduce the problem of forecasting stand volume to the simpler problem of forecasting separately the individual components in the stand-volume equation.

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LiDAR Applications to Estimate Forest Biomass at Individual Tree Scale: Opportunities, Challenges and Future Perspectives

Forests ◽

10.3390/f12050550 ◽

2021 ◽

Vol 12 (5) ◽

pp. 550

Author(s):

Dandan Xu ◽

Haobin Wang ◽

Weixin Xu ◽

Zhaoqing Luan ◽

Xia Xu

Keyword(s):

Remote Sensing ◽

Laser Scanning ◽

Forest Biomass ◽

Remotely Sensed ◽

Tree Level ◽

Biomass Estimation ◽

Future Perspectives ◽

Individual Tree ◽

The Individual ◽

Individual Trees

Accurate forest biomass estimation at the individual tree scale is the foundation of timber industry and forest management. It plays an important role in explaining ecological issues and small-scale processes. Remotely sensed images, across a range of spatial and temporal resolutions, with their advantages of non-destructive monitoring, are widely applied in forest biomass monitoring at global, ecoregion or community scales. However, the development of remote sensing applications for forest biomass at the individual tree scale has been relatively slow due to the constraints of spatial resolution and evaluation accuracy of remotely sensed data. With the improvements in platforms and spatial resolutions, as well as the development of remote sensing techniques, the potential for forest biomass estimation at the single tree level has been demonstrated. However, a comprehensive review of remote sensing of forest biomass scaled at individual trees has not been done. This review highlights the theoretical bases, challenges and future perspectives for Light Detection and Ranging (LiDAR) applications of individual trees scaled to whole forests. We summarize research on estimating individual tree volume and aboveground biomass (AGB) using Terrestrial Laser Scanning (TLS), Airborne Laser Scanning (ALS), Unmanned Aerial Vehicle Laser Scanning (UAV-LS) and Mobile Laser Scanning (MLS, including Vehicle-borne Laser Scanning (VLS) and Backpack Laser Scanning (BLS)) data.

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Application of UAV Photogrammetry with LiDAR Data to Facilitate the Estimation of Tree Locations and DBH Values for High-Value Timber Species in Northern Japanese Mixed-Wood Forests

Remote Sensing ◽

10.3390/rs12172865 ◽

2020 ◽

Vol 12 (17) ◽

pp. 2865

Author(s):

Kyaw Thu Moe ◽

Toshiaki Owari ◽

Naoyuki Furuya ◽

Takuya Hiroshima ◽

Junko Morimoto

Keyword(s):

Forest Management ◽

Forest Canopy ◽

3D Structure ◽

Three Dimensional ◽

Lidar Data ◽

Timber Species ◽

Individual Tree ◽

Aerial Photogrammetry ◽

Broadleaf Species ◽

The Individual

High-value timber species play an important economic role in forest management. The individual tree information for such species is necessary for practical forest management and for conservation purposes. Digital aerial photogrammetry derived from an unmanned aerial vehicle (UAV-DAP) can provide fine spatial and spectral information, as well as information on the three-dimensional (3D) structure of a forest canopy. Light detection and ranging (LiDAR) data enable area-wide 3D tree mapping and provide accurate forest floor terrain information. In this study, we evaluated the potential use of UAV-DAP and LiDAR data for the estimation of individual tree location and diameter at breast height (DBH) values of large-size high-value timber species in northern Japanese mixed-wood forests. We performed multiresolution segmentation of UAV-DAP orthophotographs to derive individual tree crown. We used object-based image analysis and random forest algorithm to classify the forest canopy into five categories: three high-value timber species, other broadleaf species, and conifer species. The UAV-DAP technique produced overall accuracy values of 73% and 63% for classification of the forest canopy in two forest management sub-compartments. In addition, we estimated individual tree DBH Values of high-value timber species through field survey, LiDAR, and UAV-DAP data. The results indicated that UAV-DAP can predict individual tree DBH Values, with comparable accuracy to DBH prediction using field and LiDAR data. The results of this study are useful for forest managers when searching for high-value timber trees and estimating tree size in large mixed-wood forests and can be applied in single-tree management systems for high-value timber species.

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