Horizontal Structure Research Articles

Three-dimensional forest structure features extraction based on TomoSAR

Abstract. Forest structure is an important indicator for evaluating forest ecosystem and an indispensable input parameter for estimating forest carbon sink. Synthetic Aperture Radar (SAR) Tomography (TomoSAR), as a novel microwave remote sensing technique with 3D imaging capability, has been demonstrated to be an valuable tool for accurate inversion of forest structure. At present, the forest vertical structure parameters inversion is almost all concentrated on the forest height estimation. However, the spatial structure of forests is complex, and it is not enough to only use the forest height to express the forest structure. This fails to identify tree canopy, branch layer and underlying vegetation layer, etc., resulting in the partial and inaccurate forest vertical structure information. To solve this problem, this paper constructs 3D structural indices from tomograms, namely Horizontal Structure Index (HS) and Vertical Structure Index (VS). The HS primarily describes canopy density, compensating for the lack of information on the horizontal dimension of forest structure provided by traditional TomoSAR techniques; while VS describes the complexity of canopy distribution in the altitude direction, further enriching information on forest structure vertically. In order to verify their feasibility and validity, HS and VS are extracted using six fully-polarized L-band SAR images covering the Krycklan watershed in Sweden. Moreover, the accuracy is verified by using external high-precision LiDAR data. The results indicate a strong correlation between the structural indices extracted from TomoSAR and those extracted from LiDAR.

A relação entre a heterogeneidade da paisagem e os serviços ecossistêmicos em Santa María Huatulco, Oaxaca, México

[Introduction]: The variability of geographic space, in terms of the horizontal structure of landscapes, influences ecology and suggests an association between landscape heterogeneity indices (LHI) and ecosystem services (ES). This relationship is crucial for conservation and sustainable development in Latin America, given the diversity of landscapes, from tropical forests to snow-capped mountains and deserts, which harbor a unique wealth of biodiversity and ecological functions. The objective of this study was to determine the relationship between LHI and ES. [Methodology]: Fourteen landscape heterogeneity indices and seven ecosystem services were calculated in Santa María Huatulco, Oaxaca, and related to the estimated ecosystem services for the same area. [Results]: The models showed a statistically significant relationship between LHI and ES, suggesting that certain LHI can influence the provision and distribution of ES. [Conclusions]: Therefore, understanding how LHI affect ES is essential to promote sustainable development in Latin America.

Flow Exchange In Vegetated Environments: Integrating Experimental Insights Into Practical Engineering

Vegetation provides practical protective tools for estuarine and coastal regions. The roots, stems, and canopy systems of mangroves can divert and retard the flow field within and surrounding vegetation regions (Truong et al., 2019) and also absorb external forces from waves (Phan et al., 2015). The area within the vegetation is usually calmer compared to the unprotected region outside. Consequently, sediment tends to be deposited inside the vegetation region (Vargas Luna et al., 2015). The sediment deposited then may have feedback on the wave and flow field and the growth conditions of the vegetation (Truong et al., 2017). These mutual interactions between ecological area (vegetation), hydrodynamic conditsions (wave and flow field), and morphological conditions (sediment transport) are the crux of any proposed nature-based solutions (NbS). From a hydraulic engineering perspective, these dynamic interactions can translate into the momentum and mass exchange processes between vegetation and nearby areas. By observing the evolution of mangrove forests and associated with the rate of erosion/accretion of the shoreline, Phan, 2015 and Truong., 2017 proposed a hypothesis of “squeezed mangrove forest”, in which “the mangrove width” is considered a crucial length-scales that is related to the sustainable development of the mangroves. This length scale was physically interpreted and connected to the penetration of the mixing layer into the vegetation region (Truong., 2017; Truong et al., 2019). It is noted that whereas the characteristic of the incoming waves mainly controls the penetration of the mixing layer into the coastal mangroves, that of the estuarine mangroves is mainly governed by the characteristic of lateral flow. The latter is the primary focus of this study. Large vortex structures caused by the Kelvin-Helmholtz instability at the vegetation’s edge play an essential role in the transverse exchange of mass and momentum (White & Nepf, 2007; Truong et al., 2019). These structures are usually large compared to the water depths and are termed large horizontal coherent structures (LHCSs). The Reynolds Shear stresses (RSs) induced by LHCSs contribute more than 90% to the total turbulent shear stress at the edge of the floodplain vegetated region (Truong & Uijttewaal 2019). Nevertheless, our understanding of this topic often stems from small-scale laboratory experiments. Whether the presence and characteristic of vortex structures at the interface of the low flow and fast flow region obtained from small-scale physical models remain true for estuaries and coasts has not yet been determined. In order to obtain more insight into the physics of the exchange processes occurring at the vegetation interface at different scales, two unique physical models of vegetated channels have been conducted. One small-scale and another large-scale experiment, both with and without vegetation, were conducted at TU Delft Water Lab and the Korea Institute of Civil Engineering and Building Technology - River Experiment Center (KICT-REC), respectively. Two digital twin models of this flume were subsequently constructed using Delft3D, which were calibrated and validated using the collected datasets. In this study, recent findings pertaining to these experiments are presented

The Wind Profile Characteristics of Super Typhoon Lekima Based on Field Measurement

Many cities in coastal areas are prone to typhoon disasters due to their location on the Pacific storm path, and the direct effect of catastrophic winds can lead to the destruction of low-rise buildings and severe damage to high-rise structures. The purpose of this study was to enhance the understanding of boundary layer wind profiles of strong typhoons in coastal areas and reduce property losses and casualties caused by wind disasters. Based on the field measurements of wind profile acoustic radar in coastal areas, the variation characteristics of the boundary layer wind profile during the passage of super typhoon Lekima were first studied in depth, and the evolution law of the typhoon boundary layer profile was summarized. Then, the effects of typhoon horizontal structure, topography, wind speed, and time distance on the characteristics of the typhoon profile were discussed, respectively. Finally, the evolution characteristics of wind profile parameters were obtained by fitting three wind profile theoretical models. Due to the strong variability of typhoon profile morphology, the theoretical model of wind profile is only applicable to the wind profile from the bottom to the low-level jet height of typhoons, while wind parameters are closely related to the spatial location of the typhoon wind field.

Environmental impacts of materials in masonry residential house

AbstractThis study aims to quantify the environmental impact of a specific family home, with a particular focus on its contribution to climate change. To achieve a more precise assessment, the family home was dissected into various components based on the materials’ function and their location within the structure. The evaluation was conducted using the life cycle assessment (LCA) methodology, considering the “cradle to site” boundaries and utilizing the IPCC GWP100 method. The cumulative contribution of the materials used in the selected house to climate change was found to be 125,000 kg CO2 equivalent (CO2eq). When analyzing the global warming potentials (GWP100) of individual building structures, the calculated values ranged from 3.8 to 62.2 kg CO2eq. The results indicate that the materials for horizontal structures had the lowest global warming potential values, while materials for vertical structures had the highest values. Particular attention was paid to comparing three different ways of transporting materials to the site. The portion of climate change attributable to transportation fell within a range of 10.9–12.3%. Findings verified that road transportation consistently made the greatest contribution to the overall GWP100, regardless of distance, with rail transportation yielding the lowest values. Discrepancies between the highest and lowest values of transport-related GWP100 were determined to be as much as 9.1%. Opting for the most environmentally friendly option, namely rail in this study, could result in savings of 4.9 kg CO2eq per 1 km of transportation distance for the analyzed building materials used per family house.

Mind the gaps: horizontal canopy structure affects the relationship between taxonomic and spectral diversity

ABSTRACT Spectral diversity (SD) in reflectance can be used to estimate plant taxonomic diversity (TD) according to the Spectral Variation Hypothesis (SVH). However, contrasting relationships between SD and TD have been reported by different studies. Indeed, multiple factors may affect SD, including spatial and spectral scales, vegetation characteristics and the adopted SD computational method. Here, we tested the SVH over 171 plots within a large and heterogeneous forest area in North-Eastern Italy using Sentinel-2 data, aiming at identifying possible factors affecting the strength and direction of SD-TD relationship. SD was determined using ‘biodivMapR’ (BD) and ‘rasterdiv’ (RD) R packages and 38 possible combinations of SD indices, at both α (within a community) and β (among communities) levels, and computational parameters accounting for spatial and spectral scales. Information on vegetation structure was either retrieved from ground-based or LiDAR data. A Random Forest approach was used to disentangle the relationships between SD, TD and vegetation structure, and to identify the best combination of SD computational parameters. At the α-level, we found negative relationship between TD and RD SD indices, which was mainly driven by the presence of gaps within the forest canopy. As regards BD, we found that this algorithm reduced background contribution on SD and was able to differentiate major forest types (broadleaves vs conifers), but derived α-SD indices were marginally correlated with α-TD. At the β-level, we observed a statistically significant positive correlation between BD SD indices and TD (maximum r = 0.24). Finally, we found stronger correlations and R2 when SD indices were calculated using smaller computation windows and over a larger pixels extraction area. Our findings suggest that vegetation cover and structure play a major role, with respect to inter-species spectral differences, in determining α-SD, and that SD might better capture differences in species composition at the landscape-level rather than the richness of individual communities.

Statistical Evaluation of the Accuracy of Consumer Drone Photogrammetry at a Romanesque Church in Eastern Bavaria (Germany)

For several years, photogrammetric surveys are quite often applied for surveying cultural heritage. For a detailed and accurate result, it is indispensable that the calculated point cloud represents the original geometry of the building in high quality, with vertical and horizontal structures in the same manner. Whereas many published papers in the field of digital heritage documentation are dealing with creating such models or using photogrammetric data for damage detection, only a few papers are investigating the crucial fact of accuracy and how it can be influenced by the used camera resolution. We want to present a case study, in which we compare the photogrammetric point cloud of a normal consumer drone with a high-end device. Beside the actual survey results showing the details of a Romanesque church, a statistical calculation of deviation is shown. It becomes evident that there is only a difference within some millimetres between the corresponding point clouds in most parts of the monument. Hence, it can be stated that, for most applications in heritage protection, affordable consumer unmanned aerial vehicles (UAVs) are sufficient. Only if faint details have to be resolved will a better resolution of the mounted camera be required.

Gradient matters via filament diameter-adjustable 3D printing

Gradient matters with hierarchical structures endow the natural world with excellent integrity and diversity. Currently, direct ink writing 3D printing is attracting tremendous interest, and has been used to explore the fabrication of 1D and 2D hierarchical structures by adjusting the diameter, spacing, and angle between filaments. However, it is difficult to generate complex 3D gradient matters owing to the inherent limitations of existing methods in terms of available gradient dimension, gradient resolution, and shape fidelity. Here, we report a filament diameter-adjustable 3D printing strategy that enables conventional extrusion 3D printers to produce 1D, 2D, and 3D gradient matters with tunable heterogeneous structures by continuously varying the volume of deposited ink on the printing trajectory. In detail, we develop diameter-programmable filaments by customizing the printing velocity and height. To achieve high shape fidelity, we specially add supporting layers at needed locations. Finally, we showcase multi-disciplinary applications of our strategy in creating horizontal, radial, and axial gradient structures, letter-embedded structures, metastructures, tissue-mimicking scaffolds, flexible electronics, and time-driven devices. By showing the potential of this strategy, we anticipate that it could be easily extended to a variety of filament-based additive manufacturing technologies and facilitate the development of functionally graded structures.

DCMIP2016: the tropical cyclone test case

Abstract. This paper describes and analyzes the Reed–Jablonowski (RJ) tropical cyclone (TC) test case used in the 2016 Dynamical Core Model Intercomparison Project (DCMIP2016). This intermediate-complexity test case analyzes the evolution of a weak vortex into a TC in an idealized tropical environment. Reference solutions from nine general circulation models (GCMs) with identical simplified physics parameterization packages that participated in DCMIP2016 are analyzed in this study at 50 km horizontal grid spacing, with five of these models also providing solutions at 25 km grid spacing. Evolution of minimum surface pressure (MSP) and maximum 1 km azimuthally averaged wind speed (MWS), the wind–pressure relationship, radial profiles of wind speed and surface pressure, and wind composites are presented for all participating GCMs at both horizontal grid spacings. While all TCs undergo a similar evolution process, some reach significantly higher intensities than others, ultimately impacting their horizontal and vertical structures. TCs simulated at 25 km grid spacings retain these differences but reach higher intensities and are more compact than their 50 km counterparts. These results indicate that dynamical core choice is an essential factor in GCM development, and future work should be conducted to explore how specific differences within the dynamical core affect TC behavior in GCMs.

The main approaches to valuation of the equity capital of oil and gas companies

Subject. This article analyzes the generally accepted approaches to assessing the value of companies on the basis of financial statements data of ExxonMobil, Chevron, ConocoPhillips, Occidental Petroleum, Devon Energy, Anadarko Petroleum, EOG Resources, Apache, Marathon Oil, Imperial Oil, Suncor Energy, Husky Energy, Canadian Natural Resources, Royal Dutch Shell, BP, TOTAL, Eni, Equinor (Statoil), PetroChina, Sinopec, CNOOC, Petrobras, PJSC Gazprom, PJSC NK Rosneft and PJSC LUKOIL for 1999–2018. Objectives. The article aims to determine the specifics of using the methods of cost, income and comparative approaches in assessing the value of share capital of oil and gas companies. Methods. For the study, I used the methods of comparative, and financial and economic analyses, and financial reporting data summarizing. Results. The article finds that the cost approach is quite time-consuming, and it does not take into account the current market situation and future expectations of investors, but is based on financial information. Leading oil and gas corporations have a rather complex vertical and horizontal structure, so the cost approach is acceptable for assessing the minimum cost of small companies in the industry. The income approach takes into account the interests of investors, but its application complicates the reliability of medium-term forecasts for oil prices, which is caused by fluctuations in oil prices inherent in the industry. And the amount of net income and free cash flow in the industry largely depends on oil prices. The comparative approach does not take into account the future interests of investors, but it helps quickly determine the range of possible value of the corporation based on data on transactions and the current market situation. Thus, the analogue company method helps evaluate the cost of equity capital, and the transaction method provides insight into the level of premium for control characteristic of the industry. Conclusions and Relevance. Each of the standard approaches has its own characteristic advantages and disadvantages when assessing the value of oil and gas companies. The findings can be used to appraise the value of oil and gas assets.

Effect of Internal Waves on the Hydrodynamics of a Mediterranean Sea Strait

In the present work, the effects of wind- and tide-induced internal waves in the Rio-Antirio Strait in western Greece were studied by using three-dimensional numerical simulations. For the wind-induced flow in the strait, it emerged that the internal waves’ initiation is associated with the direction of the wind. Tidal action, with or without the combined action of wind, also generates internal waves in the strait, with amplitudes higher than 20 m. The action of the internal waves causes a subsurface inflow of colder waters from the Gulf of Corinth to the Gulf of Patras, as has been also simulated for the case of the wind-induced flow, generating strong hypolimnetic currents. The exchange flowrate between the Gulf of Patras and the Gulf of Corinth appeared to undergo significant modification for the wind-induced flow and had little effect for the pure tidal flow (in windless conditions) due to the development and action of the internal waves at the strait. The combined action of the tide and the wind was found to marginally affect the exchange flowrate between the two gulfs compared to the pure tidal flow. The interaction between the Coriolis effect and internal waves, at least away from the strait, forms a characteristic horizontal structure of flow. The structure of turbulence in the near strait area under the action of internal waves generated by the wind and/or tide was also discussed and compared with the corresponding barotropic flow.

Seasonality, Latitudinal Dependence, and Structural Evolution of Arctic Cyclones

Abstract Arctic cyclones (ACs) are an important component of the Arctic climate system. While previous studies focused on case studies or samples of intense ACs, an AC tracking algorithm is applied here to ERA5 to provide more than 9300 tracks. This large sample enables evaluations of seasonality, latitudinal dependence, and the structural evolution of ACs using storm-centered composite analysis and phase space analysis. The structures of ACs of different genesis regions, polar versus midlatitude, are also examined and compared. The results show that ACs typically have an asymmetric horizontal structure with cold air to the west and warm air to the east of the cyclone center. Cyclone asymmetry decreases, and the circulation becomes more barotropic in higher latitudes. ACs of polar origin are more symmetric than ACs of midlatitude origin and dominate the cyclone occurrences over the Arctic Ocean. Regarding seasonality, winter ACs are more intense and have a stronger horizontal asymmetry, and the cyclonic circulation extends higher into the stratosphere than summer ACs. In contrast, summer ACs have stronger warm anomalies in the lower stratosphere associated with subsidence above the cyclone center, and the cyclonic circulation typically does not extend beyond 50 hPa. The latitudinal and seasonal variations of AC structure are consistent with the latitudinal and seasonal differences in environmental baroclinicity. Additionally, our analyses show that the structural evolution of ACs is characterized by reduced vertical tilt and asymmetry, weakened temperature contrast between west and east sectors in troposphere, and reduced updraft strength in the later stage of the AC life cycle. Significance Statement Arctic cyclones play a crucial role in climate projections and risk assessments for Arctic infrastructure, transportation, and other human activities. This study aims to enhance our understanding of Arctic cyclone characteristics, including their origin, structure, seasonality, and evolution. We discovered that Arctic cyclones exhibit various structures in different environments. Their degrees of symmetry, vertical tilts, temperature contrasts, and updraft strengths vary with season, latitude, and life cycle stage.

A new automatic geo-electric self-potential imaging technique for diverse sustainable development scenarios

This study introduces a rapid and efficient inversion algorithm designed for the interpretation of self-potential responses originating from mineralized and ore sources and hydrothermal activity, specifically addressing spherical, vertical, and horizontal cylindrical structures. The algorithm leverages local wavenumber and correlation imaging techniques to enhance accuracy in modeling. The correlation factor (Cf value) is crucial in this approach, calculated as the correlation between the local wavenumber of the measured self-potential field and that of the computed field. The algorithm identifies the maximum correlation Cf value (CF-max) as indicative of the optimal true model parameters. To validate the proposed algorithm, it was applied to three theoretical examples—one with contamination from regional background and another with multiple sources with and without different types of noises (random Gaussian and white Gaussian noises). Additionally, the approach was tested on three distinct real field cases related to mining, ore investigation and hydrothermal activity in India, Germany and USA. Through a comprehensive analysis of results from theoretical and real-world scenarios, including comparisons with different available data and literature information, the study concludes that the method is effective, applicable to multiple sources, accurate, and does not necessitate prior knowledge of the source shape. This algorithm presents a promising advancement in the field of self-potential interpretation for mineral exploration and geothermal exploration.

Decoding the complexity of the Brazilian pork supply chain

Purpose This research examines the impact of governance structures within the Brazilian pork supply chain on the necessary controls for exportation. Specifically, the goal is to unravel the intricacies of this supply chain and decode its complexity.Design/methodology/approach Using transaction cost economics as a theoretical lens, we surveyed the main bodies responsible for the export and quality assurance sectors of Brazilian organizations that trade and export pork. Our sample comprises 53.5% of the country’s pork exporting companies during the period analyzed.Findings The presence of vertical and horizontal governance structures in the pork export chain stands out. While the vertical structure enables greater control due to command relations, there are trust and cooperation relations in the horizontal structure. This makes it possible to establish mechanisms to control health, quality, safety and traceability in both structures. We also identified each company’s characteristics: formation configuration (if the cooperative, publicly traded company, or other modality), capital stock, location, the average daily slaughter of pigs for export and sows per producer. We conclude that the organizations have concerns related to the food safety programs, as there are programs that seek transparency throughout the process in many supply chain stages.Research limitations/implications Studies that relate the level of orientation to the export market with the occurrence or risk of corrupt and opportunistic behavior and the coordination mechanisms adopted may represent an interesting and important opportunity for studies.Originality/value This study helps to understand the complexity of the Brazilian pork supply chain.

Insights into dynamic switching behavior and electric field distribution of depletion-mode GaN HEMT with bonding pad over active layout

Bonding pad over active (BPOA) layout, which stacks traditional horizontal structure pad electrodes vertically above the active area, is an area-effective device architecture and packaging-enabled solution for GaN-based high electron mobility transistors (HEMTs). In this work, the dynamic switching and electric field distribution of such layout, as well as associated capacitance–voltage and trapping characteristics, are comprehensively studied on D-mode GaN-on-sapphire HEMT by performing numerical simulations. In terms of different pad electrodes covering the active area, BPOA is composed of various structures such as gate-related and drain-related BPOAs (i.e. G-BPOA and D-BPOA), among which G-BPOA exhibits inferior switching characteristics due to the additional introduction of Miller capacitance that prolongs the device switching, while breakdown voltage of D-BPOA is 400–900 V lower than other BPOA counterparts due to the interplay between D-BPOA and the drain electrode. Furthermore, the effects of trap capture cross section and trap density on switching characteristics are evaluated. These results highlight the differences in electrical characteristics of various structures within the BPOA layout, and provide valuable insights into BPOA device design and performance improvement.

The influence of sandwich panel cladding on horizontal structure stiffness

This paper presents a study on the influence of sandwich panel roof cladding on the horizontal stiffness of load-bearing steel structures (stressed skin action). A full-scale test was carried out on a steel monopitch portal frame structure made in two stages – without (bare steel structure) and with roof sandwich panel cladding. Data obtained from both stages of the test are presented and are used to demonstrate the significant increase in horizontal stiffness caused by the cladding system. The test data were then used to validate an FE numerical model. A roof cladding made of composite panels is relatively stiff in its own plane. However, the critical detail is the connection of the panels to the sub-structure (e.g. purlins or rafters), i.e. the screw bearing capacity. Even within the serviceability limits, the internal sheet of the composite panel suffers a certain level of permanent bearing damage. Based on the test data, the results of the FE numerical model and the analytical approach for calculating the shear stiffness of the sandwich panels, the approach for taking into account the influence of the cladding on the horizontal stiffness was derived and compared. This approach is believed to be safe and simple for practical use, and it leads to load-bearing structure members with more slender cross-sections. In addition, the data and results that are obtained expand the limited amount of available data related to stressed skin action.

An Airborne Multifrequency Microwave Analysis of Precipitation within Two Winter Cyclones

Abstract NASA’s Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) field campaign gathered data using “satellite-simulating” (albeit with higher-resolution data than satellites currently provide) and in situ aircraft to study snowstorms, with an emphasis on banding. This study used three IMPACTS microwave instruments—two passive and one active—chosen for their sensitivity to precipitation microphysics. The 10–37-GHz passive frequencies were well suited for detecting light precipitation and differentiating rain intensities over water. The 85–183-GHz frequencies were more sensitive to cloud ice, with higher cloud tops manifesting as lower brightness temperatures, but this did not necessarily correspond well to near-surface precipitation. Over land, retrieving precipitation information from radiometer data is more difficult, requiring increased reliance on radar to assess storm structure. A dual-frequency ratio (DFR) derived from the radar’s Ku- and Ka-band frequencies provided greater insight into storm microphysics than reflectivity alone. Areas likely to contain mixed-phase precipitation (often the melting layer/bright band) generally had the highest DFR, and high-altitude regions likely to contain ice usually had the lowest DFR. The DFR of rain columns increased toward the ground, and snowbands appeared as high-DFR anomalies. Significance Statement Winter precipitation was studied using three airborne microwave sensors. Two were passive radiometers covering a broad range of frequencies, while the other was a two-frequency radar. The radiometers did a good job of characterizing the horizontal structure of winter storms when they were over water, but struggled to provide detailed information about winter storms when they were over land. The radar was able to provide vertically resolved details of storm structure over land or water, but only provided information at nadir, so horizontal structure was less well described. The combined use of all three instruments compensated for individual deficiencies, and was very effective at characterizing overall winter storm structure.

High-resolution remotely sensed data characterizes indices of avifaunal habitat on private residential lands in a global metropolis

Urban ecosystems are dominated by private lands which poses a significant hurdle to performing field-based assessment of wildlife. An alternative approach is to characterize indices of animal habitat in difficult-to-access areas using data from airborne remote sensing platforms. Characterizing indices of wildlife habitat using remotely sensed data is common in natural systems but has received less attention within urban ecosystems. We tested the utility of using remotely sensed data from high-resolution airborne sensors, including LiDAR, a measure of vertical habitat structure, NDVI, a measure of greenness, image texture, a measure of horizontal habitat structure, and parcel level land-cover data, along with field-based street-tree measurements to predict bird abundance and richness across Greater Los Angeles, California, USA. We surveyed birds and gathered street-tree data on public lands of residential neighborhoods and processed the remote sensing data in 50-m and 300-m circular buffers of bird survey locations to capture data primarily on private, residential land across three winter field seasons (2016–18, 2019/20) at 23 locations along a tree-canopy cover gradient. Data from LiDAR processed as an index for the density of trees summarized in the 50-m and 300-m extents were the strongest univariate predictors of avifaunal abundance and richness explaining 75 % and 74 % of the likelihood in fitted models. NDVI, image texture, land cover, and street-tree density measures were weaker univariate predictors than models fitted with LiDAR data. Models including LiDAR and ground-based street-tree measurements accounted for upwards of 80 % of the variability in avifaunal abundance and richness, particularly for bird species associated with trees and shrubs. We recommend the prioritization of high-resolution remote sensing data, particularly LiDAR, in combination with field-based habitat measures e.g., street trees, to characterize indices of avifaunal habitat on public and private lands of cities, which could help to improve our understanding of the distribution of birds across urban areas.

Structural Stability and Weak Points Mechanism of a High and Vertical Enclosed Isolated Phase Bus

Recently, with the rapid rise of new energy generation, pumped storage power stations also have experienced rapid development. Due to the considerable vertical height of these power stations, high and vertical enclosed isolated phase buses (EIPB) are more and more widely used. This type of high and vertical EIPB structure differs from the horizontal EIPB structure, as it is more significantly influenced by the gravitational load during actual operation. Thus, it is crucial to investigate the stability of the novel high and vertical EIPB structure under its own gravity load. In this study, the strength of the I-beam and cross-arm of the EIPB under the influence of the gravitational load was studied through analytical calculations and finite element static analysis. The results indicate that the strength of the I-beam and cross-arm is within the threshold of the corresponding material’s load-bearing capacity, demonstrating the stability of the EIPB structure. This work holds significant value for the structural design and further optimization of high and vertical EIPB.

Species composition and mangrove forest structure in Buano Island, Moluccas

Mangrove forests are protected areas that play an important role for coastal communities on small islands. This study aims to convey data and information about the structure and composition of mangrove species on Buano Island. The Importance Value Index (INP) obtained from vegetation analysis is used as an indicator to describe the composition and structure of mangrove forests. The plot-assisted path method is used in vegetation analysis. 9 illustrative paths with a width of 200 m were created which were divided into 9 segments, there were 54 plots to obtain data and types of mangroves. The research results showed that there were 12 types of mangrove trees and forest regeneration (Heritiera littoralis, Rhizopora Mucronata, Rhizopora stylosa, Rhizopora apiculata, Ceriops Tagal, Sonneratia alba, Bruguiera gymnorrhiza, Lumnitzera racemose, Aegiceras corniculatum, Deriss trifoliata, Nypa fruticans, Xylocarpus granatum). The dominant species is R. mucronata. The vegetation structure at both locations also has a similar pattern the same, where the vertical structure has 2 layers/stratum of trees and both are dominated by trees with a height of 6-10 meters. Meanwhile, for the horizontal structure, the distribution of diameter classes at both locations is even, marked by a graph that forms an L curve.