scholarly journals Ecological connectivity in the three-dimensional urban green volume using waveform airborne lidar

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Stefano Casalegno ◽  
Karen Anderson ◽  
Daniel T. C. Cox ◽  
Steven Hancock ◽  
Kevin J. Gaston
2015 ◽  
Vol 6 (1) ◽  
pp. 19-29 ◽  
Author(s):  
G. Bitelli ◽  
P. Conte ◽  
T. Csoknyai ◽  
E. Mandanici

The management of an urban context in a Smart City perspective requires the development of innovative projects, with new applications in multidisciplinary research areas. They can be related to many aspects of city life and urban management: fuel consumption monitoring, energy efficiency issues, environment, social organization, traffic, urban transformations, etc. Geomatics, the modern discipline of gathering, storing, processing, and delivering digital spatially referenced information, can play a fundamental role in many of these areas, providing new efficient and productive methods for a precise mapping of different phenomena by traditional cartographic representation or by new methods of data visualization and manipulation (e.g. three-dimensional modelling, data fusion, etc.). The technologies involved are based on airborne or satellite remote sensing (in visible, near infrared, thermal bands), laser scanning, digital photogrammetry, satellite positioning and, first of all, appropriate sensor integration (online or offline). The aim of this work is to present and analyse some new opportunities offered by Geomatics technologies for a Smart City management, with a specific interest towards the energy sector related to buildings. Reducing consumption and CO2 emissions is a primary objective to be pursued for a sustainable development and, in this direction, an accurate knowledge of energy consumptions and waste for heating of single houses, blocks or districts is needed. A synoptic information regarding a city or a portion of a city can be acquired through sensors on board of airplanes or satellite platforms, operating in the thermal band. A problem to be investigated at the scale A problem to be investigated at the scale of the whole urban context is the Urban Heat Island (UHI), a phenomenon known and studied in the last decades. UHI is related not only to sensible heat released by anthropic activities, but also to land use variations and evapotranspiration reduction. The availability of thermal satellite sensors is fundamental to carry out multi-temporal studies in order to evaluate the dynamic behaviour of the UHI for a city. Working with a greater detail, districts or single buildings can be analysed by specifically designed airborne surveys. The activity has been recently carried out in the EnergyCity project, developed in the framework of the Central Europe programme established by UE. As demonstrated by the project, such data can be successfully integrated in a GIS storing all relevant data about buildings and energy supply, in order to create a powerful geospatial database for a Decision Support System assisting to reduce energy losses and CO2 emissions. Today, aerial thermal mapping could be furthermore integrated by terrestrial 3D surveys realized with Mobile Mapping Systems through multisensor platforms comprising thermal camera/s, laser scanning, GPS, inertial systems, etc. In this way the product can be a true 3D thermal model with good geometric properties, enlarging the possibilities in respect to conventional qualitative 2D images with simple colour palettes. Finally, some applications in the energy sector could benefit from the availability of a true 3D City Model, where the buildings are carefully described through three-dimensional elements. The processing of airborne LiDAR datasets for automated and semi-automated extraction of 3D buildings can provide such new generation of 3D city models.


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1374
Author(s):  
Hefei Wang ◽  
Zongping Pei

The undergoing trend and development towards urbanization and the consequences of socio-ecological and climate change are increasing the pressure on cities worldwide. The planning of urban green and blue spaces is essential for sustainable urban development, especially for the conservation of urban ecosystems in fast-growing cities. In this context, the spatial-explicit and ecological connectivity analyses of urban green infrastructure are helpful tools for planning and the evaluation of spatial patterns and their changes for the sustainability of urban development. The aim of this study is to understand the influence of urban expansion on the urban green corridors. In this paper, we present an analysis of ecological networks for green infrastructure planning at the city level, making the most out of morphological spatial pattern analysis (MSPA) techniques and social-ecological analysis methods. The findings reveal the changes of spatial patterns of urban green and blue areas in Gaoyou city and disclose its ecological corridors and connectivity from 1990 to 2012. The urban green corridors analysis method proposed here can be used in other cities and allow for the production of spatially detailed urban ecological connectivity assessment and monitoring. Recommendations to enhance and conserve green corridors and ecological networks such as reserving networks in the east of the example city have been concluded. The conclusion obtained using our spatial analysis method can be used in other municipalities to serve as spatial-explicit tools for urban green spaces and land use planning.


2019 ◽  
Vol 9 (12) ◽  
pp. 2452 ◽  
Author(s):  
Minsu Kim

An airborne lidar simulator creates a lidar point cloud from a simulated lidar system, flight parameters, and the terrain digital elevation model (DEM). At the basic level, the lidar simulator computes the range from a lidar system to the surface of a terrain using the geomatics lidar equation. The simple computation effectively assumes that the beam divergence is zero. If the beam spot is meaningfully large due to the large beam divergence combined with high sensor altitude, then the beam plane with a finite size interacts with a ground target in a realistic and complex manner. The irradiance distribution of a delta-pulse beam plane is defined based on laser pulse radiative transfer. The airborne lidar simulator in this research simulates the interaction between the delta-pulse and a three-dimensional (3D) object and results in a waveform. The waveform will be convoluted using a system response function. The lidar simulator also computes the total propagated uncertainty (TPU). All sources of the uncertainties associated with the position of the lidar point and the detailed geomatics equations to compute TPU are described. The boresighting error analysis and the 3D accuracy assessment are provided as examples of the application using the simulator.


2019 ◽  
Vol 16 (7) ◽  
pp. 1493-1503 ◽  
Author(s):  
Shaun R. Levick ◽  
Anna E. Richards ◽  
Garry D. Cook ◽  
Jon Schatz ◽  
Marcus Guderle ◽  
...  

Abstract. Fire regimes across the globe have been altered through changes in land use, land management, and climate conditions. Understanding how these modified fire regimes impact vegetation structure and dynamics is essential for informed biodiversity conservation and carbon management in savanna ecosystems. We used a fire experiment at the Territory Wildlife Park (TWP), northern Australia, to investigate the consequences of altered fire regimes for vertical habitat structure and above-ground carbon storage. We mapped vegetation three-dimensional (3-D) structure in high spatial resolution with airborne lidar across 18 replicated 1 ha plots of varying fire frequency and season treatments. We used lidar-derived canopy height and cover metrics to extrapolate field-based measures of woody biomass to the full extent of the experimental site (R2=0.82, RMSE = 7.35 t C ha−1) and analysed differences in above-ground carbon storage and canopy structure among treatments. Woody canopy cover and biomass were highest in the absence of fire (76 % and 39.8 t C ha−1) and lowest in plots burnt late in the dry season on a biennial basis (42 % and 18.2 t C ha−1). Woody canopy vertical profiles differed among all six fire treatments, with the greatest divergence in height classes <5 m. The magnitude of fire effects on vegetation structure varied along the environmental gradient underpinning the experiment, with less reduction in biomass in plots with deeper soils. Our results highlight the large extent to which fire management can shape woody structural patterns in savanna landscapes, even over time frames as short as a decade. The structural profile changes shown here, and the quantification of carbon reduction under late dry season burning, have important implications for habitat conservation, carbon sequestration, and emission reduction initiatives in the region.


2013 ◽  
Vol 807-809 ◽  
pp. 1921-1927
Author(s):  
Peng Tong ◽  
Hong Cheng Liu ◽  
Shuai Hua Gao

Airborne LiDAR System is a laser detection and ranging system for quickly obtaining high-precision, high-density three-dimensional coordinate data. The target information after the geological disasters can be victimized for disaster assessment and decision analysis to provide effective support, LiDAR provides a new technical means for disaster mitigation, relief works. This paper focuses on the application of airborne LiDAR system in geological disasters, it summarizes some experience of the LiDAR point data acquisition and processing, and the results of the LiDAR point data.


2014 ◽  
Vol 2 (2) ◽  
pp. 123-137 ◽  
Author(s):  
Jennifer Weber ◽  
Terry G. Powis

AbstractThe majority of terrestrial scanning projects in archaeology have focused on heritage documentation, preservation, and the three-dimensional (3D) reconstruction of prominent sites and objects. While these are very important archaeological foci, not many have used terrestrial scanning methods for prospection and feature analysis, similar to the way many have employed airborne LiDAR. While airborne LiDAR scanning is able to situate and analyze archaeological sites on an expansive scale, the ground-based method also captures and defines any landscape anomalies or depressions from cultural features that have remained invisible to the naked eye due to environmental restrictions. In an attempt to test this recording method, we set out to paint a non-invasive, 3D digitized picture of the ancient Maya site of Pacbitun, Belize, using terrestrial scanning to distinctly detail Pacbitun’s structures, plazas, causeways, and karst features. This paper details the process through which 3D terrestrial scanning was executed at Pacbitun and three associated peripheral caves during the 2012 and 2013 field seasons. We discuss the potential laser scanning has for visual analysis in archaeology and evaluate application difficulties encountered in the field, as well as current data interpretation issues.


Sign in / Sign up

Export Citation Format

Share Document