Developing a land-cover classification to select indicators of forest ecosystem health in a rapidly urbanizing landscape

As moderate-sized cities become more urbanized, ecosystems are altered by land-use change. Key ecological services, such as clean air and water, drought and flood protection, soil generation and preservation, and detoxification of wastes are disrupted, risking the health and welfare of society. An understanding of ecosystem responses to urbanization is necessary to evaluate and balance short-term needs with long-term sustainability goals. Our main objective was to develop a land management and planning tool using a land-cover classification to select landscape indicators of ecosystem health near Columbus, GA. Spearman's Rho correlations were calculated to compare landscape and field-based indicators. Results suggest there are significant inverse correlations between ‘percent forest land-cover’ and ‘population, housing, and road densities’; ‘tree species richness’ and ‘forest patch density’; ‘percent urban land-cover’ and ‘lichen species richness’; ‘lichen incidence’ and ‘forest perimeter-area fractal dimension’. Overall, there were 152 significant urban/biological correlations obtained from this assessment (Rho ≥ |0.50| and p ≤ 0.10). Such a tool could prove useful to land managers and environmental planners by providing a quick and simple method to assess broad areas of land in a single analysis.     

Diurnal thermal behavior of selected urban objects using remote sensing measurements

This research analyzes and summarizes some thermal behavior of various urban surfaces in time and space using high-resolution video thermal radiometer situated at a height of 103 m, in the city of Tel-Aviv. The physical properties of the various urban elements, their color, the sky view factor (SVF), street geometry, traffic loads, and anthropogenic activity are important among the factors that determine the radiant surface temperature in the urban environment. During daytime, asphalt paved roads and rooftops were found to be the warmest urban elements in our study area. In contrast, exterior walls and trees hold the highest surface temperatures at night. Open spaced surfaces that are exposed to direct solar radiation during daytime and to heat loss at night were characterized by the highest diurnal temperature range. The radiometric stationary experiment revealed the temperature differences between diverse urban coverage to be at most 10 °C; such maximum temperature differences were measured in the early noon hours. The minimal temperatures were observed just before sunrise, when the temperature contrasts (4–5 °C) were smaller than in the early noon hours. The daytime hours between 9–10 a.m. and 5–8 p.m. turned out to be problematic for remote sensing of the urban environment, because the thermal differences between different objects were found to be insignificant. A remote survey aiming to study the urban environment should be conducted twice: in the early morning hours before sunrise (5 a.m.) and in the early noon hours (12–1 p.m.). The knowledge of thermal behavior of various urban components is an important tool for designers and decision-makers. If utilized properly, it can lead to climatic rehabilitation in urban areas and a reduction of the UHI.     

Integrating Augmented Reality with Building Information Modeling: Onsite construction process controlling for liquefied natural gas industry

The extent of effectiveness of real-time communication within BIM environment is somehow restrained due to the limited sense of immersion into virtual environments. The objective of this paper highlights the need for a structured methodology of fully integrating Augmented Reality (AR) technology in BIM. Based on the generic review of BIM in construction, this paper forms the rationales for the onsite information system for construction site activities, and then formulates the methods of configuring BIM + AR prototypes. It is demonstrated that, extended to the site via the “hand” of AR, the BIM solution can address more real problems, such as low productivity in retrieving information, tendency of committing error in assembly, and low efficiency of communication and problem solving.     

Maximum surface settlement based classification of shallow tunnels in soft ground

Prediction of the maximum surface settlement due to shallow tunnelling in soft grounds is a valuable metrics in ensuring safe operations, particularly in urban areas. Although numerous researches have been devoted to this issue, due to the complexity and a large number of the effective parameters, no comprehensive solution to the problem is available. In this study, a shallow tunnel classification system (STCS), based on maximum settlement, is proposed. The STCS holds on the results of several tunnelling projects around the world. The classifier categorises a tunnel based on geometry, ground, and performance characteristics. A decision tree classification method, after training with 20 cases, was successful to predict the maximum settlement for 14 tunnelling projects. The maximum surface settlement predictions were in the form of assigning a class label to each tunnel. Four tunnel classes were defined as follow: (i) class A (maximum settlement < 9.9 mm), (ii) class “B” (10 ⩽ maximum settlement < 19.9 mm), (iii) class “C” (20 ⩽ maximum settlement < 29.9 mm), and (iv) class “D” (maximum settlement ⩾ 30 mm). The most explanatory independent variables were selected, by the STCS, as follow: tunnel depth, diameter, volume loss, and normalised volume loss. The proposed classification scheme can be employed as a decision making aid in settlement prediction/prevention in shallow tunnelling in soft grounds. The STCS is proposed as a supplemental tool to the observational methods, and it is not expected to be a stand-alone measure for settlement.     

Environmental driving forces of urban growth and development: An emergy-based assessment of the city of Rome,Italy

Large urban systems can be considered as the final point of convergence of resources, environmental services and human activities from rural settlements to villages to towns to small and big cities. The emergy synthesis method is applied in order to capture the complexity of urban systems from the point of view of the larger scale, the geobiosphere, where resources come from. Emergy is the total available energy of one kind (usually solar) directly or indirectly used up to drive a system or a process. It can be considered as a measure of a system's demand for environmental support. The population of Rome is 4.43% of total Italian population, with an emergy use of about 4% of total emergy supporting the Italian economy. Emergy use per capita is 5.50E+16 seJ/year, compared to an average value for Italy of 3.60E+16 seJ/year. An empower density of 1.09E+14 seJ/m²/year was calculated for Rome, much higher than for average Italy, 6.86E+12 seJ/m²/year. Finally, the emergy/GDP, an indirect measure of economic performance of the system, is 2.43E+12 seJ/€ for Rome compared to 1.64E+12 seJ/€ for Italy, suggesting that in an urban system (generally characterized by a larger fraction of tertiary activities) the required environmental support for the generation of economic results is much higher than for the whole economic system. Finally, comparison of above performance indicators with similar studies published by other authors (Taipei, San Juan and Macao) points out that Rome has the highest annual emergy per capita (suggesting higher potential standard of living).     

A laboratory study on stone matrix asphalt using ground tire rubber

This research investigated the feasibility using asphalt rubber (AR), produced by blending ground tire rubber (GTR) with an asphalt, as a binder for stone matrix asphalt (SMA). Two different sizes of GTR produced in Taiwan were used. The potential performance of AR–SMA mixtures was also evaluated. The results of this study showed that it was not feasible to produce a suitable SMA mixture using an asphalt rubber made by blending an AC-20 with 30% coarse GTR with a maximum size of 0.85 mm. However, SMA mixtures meeting typical volumetric requirements for SMA could be produced using an asphalt rubber containing 20% of a fine GTR with a maximum size of 0.6 mm. No fiber was needed to prevent drain-down when this asphalt rubber was used. The AR–SMA mixtures were not significantly different from the conventional SMA mixtures in terms of moisture susceptibility from the results of AASHTO T283 tests. The results of the wheel tracking tests at 60 °C show that rutting resistance of AR–SMA mixtures was better than that of the conventional SMA mixtures.     

Shaking table test on reinforcement effect of partial ground improvement for group-pile foundation and its numericalsimulation

In this paper, particular attention was paid to the seismic enhancement effect of group-pile foundation with partial ground improvement method that is used for existing pile foundations in practical engineering. A model test on a full system with a superstructure, a nine-pile foundation and a sandy ground was conducted with the shaking table test device. The model pile is made from aluminum and the model ground is made from Toyoura Sand. The shaking table test device is 120 cm in width and 160 cm in length. The maximum acceleration is 1 g and the maximum displacement is 5 cm. The maximum payload is 16 kN and the highest frequency is 10 Hz. The model ground is carefully prepared to obtain a ground with controllable unified density. Before the shaking table test, the pattern of the partial ground improvement for an existed group-pile foundation is carefully selected using numerical tests with a 3D elastoplastic static finite element analysis. In the analysis, the nonlinear behavior of ground and piles are described by the cyclic mobility model (Zhang et al., 2007) and the axial force dependent model (AFD model) proposed by Zhang and Kimura (2002) can take into consideration of axial-force dependency in the nonlinear moment–curvature relations. The applicability of the numerical analysis has been verified in previous works by comparing the numerical results with a real-scale field tests (Kosa et al., 1998). Based on the results from the numerical tests on seismic enhancement effect of group-pile foundation with ground improvement, an optimum pattern of partial ground improvement of an existing pile foundations has been picked out for shaking table test. A numerical analysis using the program DBLEAVES (Ye, 2007) is also conducted for the same optimum pattern for comparison purposes. The effectiveness of the partial ground improvement method has been proved by both the shaking table test and the numerical analysis.     

Applications of mesh parameterization and deformation for unwrapping 3D images of rock tunnels

This paper presents analysis on two 3D mesh to 2D map strategies applied to unwrap images of rock tunnels and facilitate visualization of large datasets. First, we examined mesh parameterization algorithms which are used in computer graphics to convert a 3D mesh model to a 2D representation.We found that while these methods were automatic and could provide 2D maps with minimal metric distortion (ie: conservation of lengths in 3D when mapped to 2D), they exhibited twisted shapes and were not intuitive to interpret. Second, we proposed two novel approaches, combining mesh deformation algorithms, which are used in computer animation to reshape a 3D mesh to resemble a 3D plane, and projection onto a 2D plane. We found that while these methods required user interaction and introduced a greater amount of metric distortion, their outputs were fairly intuitive to interpret. To compare the relative merits of mesh parameterization and mesh deformation and projection, the different strategies are applied to a 8.2 m wide by 41 m long by 6.7 m high subsection of a mining tunnel. The metric distortion produced was calculated and their respective output 2D maps are presented and discussed.     

Influence of traffic force on pollutant dispersion of CO,NO and particle matter (PM2.5) measured in an urban tunnel in Changsha,China

Environmental safety issues and ventilation problems caused by the construction of urban tunnel have increasingly been attracting people’s attention. Previous studies in China have mainly focused on vehicle emissions and ventilation control technologies in road tunnels, resulting in a research gap on urban tunnel ventilation engineering design. Therefore, a detailed monitoring investigation was conducted from May 22 to June 2, 2013 in Changsha Yingpan Road Tunnel, China. The study aim was to measure the traffic characteristics, air velocity and the carbon monoxide (CO), nitrogen oxides (NO_x) and fine particulate matter (PM_2.5) concentrations in this tunnel, which has two lanes per bore and multiple ramps. Measurement results show that during the workday morning peak, the maximum traffic flow was 1560 passenger-car-unit/h per lane with vehicle speed around 33.6 km/h in the eastbound tunnel, the average air velocity was 3.07 m/s, and the proportion of the light-duty vehicles (LDV) was 97.3%. Under the traffic force (not open fan), the CO and NO average concentrations at the main tunnel outlet were 20.3 ppm and 1.65 ppm, respectively. The gas pollutant concentrations are effectively controlled within the multiple-ramps tunnel and the design air volume flow is noticeably reduced. The traffic air flow was found to provide 32.5% of the required air volume to dilute NO_x in blocked traffic condition (vehicle speed of 10 km/h). In addition, the PM_2.5 concentration is mainly affected by the value of background outside the tunnel. The result can provide a quantitative assessment method to support pollutant concentration control and contribution of requested air volume by traffic flow in urban complex structure tunnel.     

Effect of calcination temperature on the pozzolanic activity of sugar cane bagasse ash

This work presents the results of the processing of sugar cane bagasse ash (SCBA) under controlled calcination conditions in order to obtain materials with optimum pozzolanic activity. Bagasse samples were burnt in an aired electric oven with a heating rate of 10 °C/min, at 350 °C for 3 h, and at different temperatures ranging from 400 to 800 °C for another 3 h. For all calcination temperatures the pozzolanic activity, structural state of silica and loss on ignition of the ashes were determined. Moreover, the SCBA with greater pozzolanicity was characterized by using chemical analysis, scanning electron microscopy, density, specific surface area and chemical reactivity.     

Thermography as a technique for monitoring early age temperatures of hardening concrete

The exothermal character of cement hydration reactions causes concrete to endure temperature changes during the first days after casting, with associated volumetric deformations that may induce undesired cracking. The capability to predict temperature evolution in concrete since casting is thus important to back decisions that avoid detrimental thermal cracking in concrete structures. Even though several approaches exist to model the early age behavior of concrete, the laboratory or in situ verification of numerical predictions is scarce, and mostly done with embedded temperature sensors, with limited sampling points. The present research intends to evaluate the performance of the thermography technique in the continuous monitoring of surface temperatures of a hydrating 0.40 × 0.40 × 0.40 m³ concrete cube, in which embedded thermal sensors are also used. By using thermography, simultaneous monitoring of the visible surfaces of the specimen is possible, thus providing comprehensive information regarding the evolution of surface temperatures. The temperatures monitored with the thermography, as well as with the embedded temperature sensors, are finally used as a benchmark example for validation of a 3D finite element numerical code for thermal analysis developed by the authors. The use of thermography images for validation of finite element results is rather more advantageous than the use of standard single point temperature measurements, in view of the large facility and wide range of comparison provided by the simultaneous visualization of temperature surface color maps (measured and simulated).     

Coherence and fragmentation of landscape patterns as characterized by correlograms: A case study of Estonia

The homogenization and fragmentation of landscapes caused by intensive management is an increasing problem worldwide. Therefore, there is need for development of methods that help to improve sustainable management and maintain the identity of landscapes. We proposed that landscape coherence is the similarity between soil pattern (potential landscape) and land use intensity (actual landscape), which may be investigated by means of correlograms. We studied the spatial autocorrelation (Moran's I) of raster format soil maps and land use maps (1:10,000; 10 m pixel size) in 35 study areas representing all landscape regions in Estonia. Various soil characteristics were taken into consideration in compiling the scale of contrast of 17 soil groups, whereas 19 land use types were ordered according to the intensity of human influence. We use a simple characteristic based on correlograms: a half-value distance lag, h_I = 0.5, a distance where Moran's I equals 0.5. According to the value of h_I = 0.5, in till-covered areas, the landscape structure is more fragmented in uplands than in lowlands. We found two study areas where the soil pattern was coherent with land use intensity, and detected a tendency that human influence makes the landscape pattern in uplands more homogeneous and in lowlands more heterogeneous, whereas the similarity between landscape patterns in lowlands and uplands is increasing due to human influence. This concept of coherence helps planners and decision makers to determine the optimal land use in landscapes by either reducing or increasing the fragmentation of the landscape pattern.     

Interactive fire spread simulations with extinguishment support for Virtual Reality training tools

Virtual Reality training for fire fighters and managers has two main advantages. On one hand, it supports the simulation of complex scenarios like big cities, where a fire cannot be simulated in the real world. On the other hand, fire fighting VR simulators allow trainees to experience situations as similar as possible to real fire, reducing the probability of accidents when they are practising exercises with real fire.The success of the Virtual Reality training tools also depends on how close to reality the simulation process is. This work provides fire spread algorithms for forest and urban environments, which can be used at interactive rates. Due to the interactive nature of the algorithms, the users are able to fight the fire by throwing extinguishing agents.Although the algorithms assume many simplifications of the problem, their behaviour is satisfactory. This is due to the efficient management of the cell states in a 3 m×3 m cell grid. Also the variables that have more influence on fire propagation constitute the core of the algorithms. The overall system deals with user extinguishment actions, natural and artificial firebreaks, variable wind conditions (even at a cell level) and non-contiguous fire propagation (embers and spotting fires). The unified forest/urban model leads to an object oriented architecture which supports the fire propagation algorithms. This also allows the system to compute efficiently mixed forest–urban environments.     

Determinants of winter indoor temperatures in low income households in England

The objective of this study is to quantify the extent to which variation in heating season indoor temperatures is explained by dwelling and household characteristics and increased by energy efficiency improvements in low income households. A survey of dwellings in the Warm Front home energy efficiency scheme was carried out in five urban areas of England. Half-hourly living room and main bedroom temperatures were recorded for 2–4 weeks over two winters. For each dwelling, regression of indoor on outdoor temperature was used to obtain estimates of daytime living room and night time bedroom temperatures under standardized conditions (outdoor temperature of 5 °C). The results indicate that the median standardized daytime living room temperature was 19.1 °C and the median standardized night time bedroom temperature 17.1 °C. Temperatures were influenced by property characteristics, including its age, construction and thermal efficiency and also by the household number of people and the age of the head of household. Dwellings that received both heating and insulation measures through the Warm Front scheme had daytime living room temperatures 1.6 °C higher than pre-intervention dwellings, night time bedroom temperatures were 2.8 °C higher. Warm Front energy efficiency improvements lead to substantial improvements of both living room and bedroom temperatures which are likely to have benefits in terms of thermal comfort and well-being.     

The dependence of offshore turbulence intensity on wind speed

Four years of 10 min mean wind data from the offshore measuring platform FINO1 (Forschung in Nord-und Ostsee 1) in the German Bight have been analyzed to obtain the dependence of turbulence intensity on the wind speed. The investigated dataset is unique in so far as no high quality long-term measurements with a height resolution of 10 m at heights between 33 and 103 m and a minimum distance to the coast of 45 km have been available so far.Wave height and therefore sea surface roughness and turbulence intensity increase with increasing wind speed. The influence of the surface roughness decreases with height. Results are compared to previous results and to the specifications given by the IEC wind turbine standards 61400-1 and 61400-3.     

Estimating geometrical and mechanical REV based on synthetic rock mass models at Brunswick Mine

This paper uses a case study from Brunswick Mine in Canada to determine a representative elementary volume (REV) of a jointed rock mass in the vicinity of important underground infrastructure. The equivalent geometrical and mechanical property REV sizes were determined based on fracture systems modeling and numerical experiments on a synthetic rock mass. Structural data collected in massive sulphides were used to generate a large fracture system model (FSM), 40 m×40 m×40 m. This FSM was validated and subsequently sampled to procure 40 cubic specimens with a height to width ratio of 2 based on sample width from 0.05 to 10 m. The specimens were introduced into a 3D particle flow code (PFC3D) model to create synthetic rock mass (SRM) samples. The geometrical REV of the rock mass was determined based on the number of fractures in each sampled volume (P₃₀) and the volumetric fracture intensity (P₃₂) of the samples. The mechanical REV was estimated based on the uniaxial compressive strength (UCS) and elastic modulus (E) of the synthetic rock mass samples.The REV size of the rock mass was determined based on a series of statistical tests. The T-test was used to assess whether the means of the samples were statistically different from each other and the F-test to compare the calculated variance. Finally, the coefficient of variation, for the synthetic rock mass geometrical and mechanical properties, was plotted against sample size. For this particular site the estimated geometrical REV size of the rock mass was 3.5 m×3.5 m×7 m, while the mechanical property REV size was 7 m×7 m×14 m. Consequently, for engineering purposes the largest volume (7 m×7 m×14 m) can be considered as the REV size for this rock mass.     

Experimental study of the mechanical behavior of continuous glass and carbon yarn-reinforced mortars

This work aims to evaluate the possibilities of cementitious materials reinforcement by continuous alkaline resistant AR glass or carbon yarns. Bond flexural tests and flexural tests on 7 × 7 × 28-cm specimens were performed at various ages of the mortar and with various layouts and, volume fractions of yarn. The flexural tests showed the capacity of yarn to improve the strength and ductility of the mortar. A definition of the effectiveness of a yarn as reinforcement is given as proportional to the ratio of the post-cracking maximal load on the product of the strength of yarn and the volume fraction of yarns. The effectiveness of a yarn seems to depend on its structure: the one of the carbon yarn, made up of micrometric filaments, is lower than the one of the glass yarn, made up of millimetric strands. Losses of strength and ductility were observed between 28 days and a year for the glass yarn-reinforced mortars. For the carbon yarn-reinforced mortars, post-cracking strength increases with time.