Does spatial configuration matter? Understanding the effects of land cover pattern on land surface temperature in urban landscapes

The effects of land cover composition on land surface temperature (LST) have been extensively documented. Few studies, however, have examined the effects of land cover configuration. This paper investigates the effects of both the composition and configuration of land cover features on LST in Baltimore, MD, USA, using correlation analyses and multiple linear regressions. Landsat ETM + image data were used to estimate LST. The composition and configuration of land cover features were measured by a series of landscape metrics, which were calculated based on a high-resolution land cover map with an overall accuracy of 92.3%. We found that the composition of land cover features is more important in determining LST than their configuration. The land cover feature that most significantly affects the magnitude of LST is the percent cover of buildings. In contrast, percent cover of woody vegetation is the most important factor mitigating UHI effects. However, the configuration of land cover features also matters. Holding composition constant, LST can be significantly increased or decreased by different spatial arrangements of land cover features. These results suggest that the impact of urbanization on UHI can be mitigated not only by balancing the relative amounts of various land cover features, but also by optimizing their spatial configuration. This research expands our scientific understanding of the effects of land cover pattern on UHI by explicitly quantifying the effects of configuration. In addition, it may provide important insights for urban planners and natural resources managers on mitigating the impact of urban development on UHI.     

Accuracy and congruency of three different digital land-use maps

For numerous model applications in the earth and environmental sciences, digital land-use data are indispensable as a source of information on the geographical distribution of the land-use/cover. Therefore, the land-use data sets ATKIS, CORINE Land Cover, and Landsat TM classifications are widely used in Germany. However, the users of these data mostly do not have information on their quality. In this study, the accuracy of the three above-mentioned digital land-use maps was evaluated a posteriori based on the results of a field inventory in two test areas with a total area of 17 km². The results show that the overall accuracy of the land-use maps varies from 0.692 to 0.876. For the individual land-use classes, the user accuracy ranged from less than 0.001 to 0.991. In this paper, the positional congruency of the land-use class polygons among the three maps was also evaluated for a larger study region of 670 km² in the state of Hessen (Germany). This region is a small structured landscape with a relatively high portion of fallow land. In the analysis, the following six land-use classes were considered: urban and traffic areas, forest, water, arable land, pastures and meadows, and fallow land (including other uses). The results showed that the congruency of the land-use classes forest and urban and traffic areas is higher than the congruency of the land-use classes of the open land (arable land, pastures and meadows, fallow).     

Drivers of land abandonment in Southern Chile and implications for landscape planning

In recent decades, land abandonment has become one of the most important trends in land use and cover change. This study identifies drivers of land abandonment in Southern Chile through a spatially explicit statistical model, based on an economic theoretical framework. A logistic regression was used to model the probability of land abandonment, observed as the land cover change from agricultural land to arboreous shrubland or native forest between 1985 and 2007. We relied on census information and land cover data from 2472 farms, which represented 86.6% of the farm population in the study area. Land cover data came from two Landsat scenes taken in 1985 (TM) and 2007 (ETM+). The results from the spatial analysis show that agricultural land covered 30 061 ha in 1985. By 2007, only 16 518 ha had persisted in agriculture, while the rest had been covered by natural vegetation. Soil quality was a significant benefit-related geophysical driver of land abandonment. Important cost related socioeconomic drivers were the distances to secondary roads, aquaculture production centers, and national parks, and the existence of farm subsidies. Significant farm structural variables were the amount of bovine heads and farm's livestock carrying capacity. Variables such as age, education, and place of residence of the farmer were not statistically significant. These results may serve as an important planning tool for land managers, by helping identify areas and farming systems with high probability of land abandonment, and furthermore explore the outcomes of some potential scenarios on the future probability of the process.     

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.     

Predicted effects of residential development on a northern Idaho landscape under alternative growth management and land protection policies

Land use change driven by exurban development can lead to dramatic alterations in the structure and function of landscapes. Residential development outside of urban and suburban zones can disrupt agricultural and forest management operations and ecosystem processes, increase community wildfire hazard, deplete groundwater resources, and lead to social conflict. We assessed two policy tools, urban growth boundaries and agricultural use zoning, for their potential to help manage growth and sustain the rural landscape. Using a survey-based model, we simulated the effects of the two policy tools on land use change and compared the results with predictions of land use change for two rural counties (4794 km²) in northern Idaho developed in a previous project. We measured the effects of predicted exurban development using four measures: number of housing units predicted on productive agricultural lands, number of housing units predicted on a groundwater resource area, changes to a wildfire hazard index for residential structures, and the social acceptability of residential development patterns given current development preferences. The two policy tools impose in substantially different landscape-level residential development patterns when compared to the baseline change prediction and each other. Each tool resulted in a variety of tradeoffs between negative and positive effects among our measures of impact. Our findings demonstrate the importance of using multiple indicators to evaluate growth management and land protection policy tools for making land use planning decisions.     

Creation and adaptive management of a wild bird habitat on reclaimed land in Osaka Port

We examined the efficacy of habitat creation for shorebirds on reclaimed land in Osaka Port. The Wild Bird Park was laid out on a reclaimed land in Osaka Port in 1983. A modern history of the area as a habitat for shorebirds can be divided into four stages. First, many shorebirds visited the tidal flat of 30 ha that emerged on the south part of the Sakishima, which had been reclaimed from the sea in 1941, but was abandoned between 1950 and 1958 [Notes on Osaka Bay Waders. Private Publishing (in Japanese with English abstract)]. Second, the tidal flat disappeared because of the start of the reclamation of the north part of Sakishima in 1958, and a salt marsh of 85 ha emerged in the north part between 1974 and 1982. Third, the salt marsh disappeared due to the construction and the Wild Bird Park was opened on a part of the salt marsh in 1983. The park had a planted area of 6.5 ha and a sandy area of 12.8 ha, which included two ponds and a lagoon. Fourth, one of the ponds was restored to a tidal flat in 1995 after consultation among the manager, NPO, and scientist as a result of the monitoring. The area of tidal flat increased from 0.2 to 2.6 ha, and the number of shorebirds increased from 205 (the average of 1991–1995) to 1042 (1996). The abundance and species richness of shorebirds is equivalent to those at the first stage (1950s). The species composition of benthic animals had also changed; the dominant group was Chironomid larvae during the second and third stages and Polychaetes during the fourth stage, and the species richness was greatest at the fourth stage. However, the tidal flat of the park had fewer brachyurans and mollusks than natural tidal flats in Japan. This might result in a lower abundance of large sandpipers at the fourth stage compared with that at the first and second stages.     

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.     

Velocity and temperature attenuation of a ceiling-jet along a horizontal tunnel with a flat ceiling and natural ventilation

A series of fire tests was conducted in a small-scale tunnel with dimensions of 10.0 m (L) × 0.75 m (W) × 0.45 m (H) and a rectangular cross-section. Detailed measurements of the velocity and temperature within a steady fire-driven ceiling-jet running along the centre of the ceiling were conducted.Referring to a theoretical derivation process described in the literature as a starting point, correlations representing the velocity and temperature attenuation along the tunnel axis were developed.The values of the coefficients included in the developed correlation for the velocity attenuation were measured using a particle image velocimetry system during the experiments conducted in the small-scale tunnel. The value of the Stanton number was determined by considering the ceiling-jet thickness, which was derived from the velocity distribution. The values of the coefficients included in the developed correlation for the temperature attenuation were also determined based on experimental results described in the literature, which were obtained in a large-scale tunnel constructed using good heat insulation properties.Through these correlations developed for the velocity and temperature attenuations along the tunnel axis, the variation in the Richardson number of the ceiling-jet based on the distance from the fire source position along the tunnel axis was examined, and the position where the ceiling-jet changed from a shooting flow to a tranquil flow was determined. The boundary positions between the shooting and tranquil flows were determined using correlations between the velocity and/or temperature attenuation, which were compared with the variation in the Richardson number along the tunnel axis to verify their appropriateness.     

The significance of landscape relic zones in relation to soil conditions,settlement pattern and territories in Flanders

Since the 18th century and increasingly since the second half of the 20th century, the transformation of the ancient landscape structures has been devastating. In densely populated and highly industrialized areas, such as Flanders (Belgium), only fragments remain from the traditional landscapes of the end of the 18th century. The recently finalized Landscape Atlas of Flanders (2001) gives an inventory of these areas, which are called relic zones and still cover 39% of the country. Their spatial distribution shows a striking way the old communal borders in the periphery of the ancient territories of the villages. Land qualities related to different phases of land occupancy were defined based upon soil and landform. Ten soil associations were overlaid with the relic zone map using ArcView GIS. Distinct soil associations characterize the different historical landscape regions. The spatial correspondence between landscape regions, soil associations and relic zones showed that half of all designated relic zones correspond to at least three major phases and regions of landscape development. The proportion of relic zone areas is extremely low in the urban regions (2.1%), less than average in the sandy area’s and higher than average in the polders, loamy regions and alluvial regions. The average patch size of the relic zones is 2.90 km² for Flanders but varies from 0.13 to 24.35 km². Overall fragmentation is 0.13 patches/km² in Flanders, and this varies from 0.04 (loamy plateaus) to 0.19 (coastal zones). Sizes of communal territories in Flanders vary a lot and so do the eccentricity of the settlement site and the proportion of relic zone area in the territory. Larger territories are found in the sandy regions in the north and the west of Flanders and correspond to recent settlements in former forest areas and heath lands. The average CPA shape index (1.523) indicates that square to rectangular shapes are dominant. Most eccentric sites are situated in the larger territories in northern Flanders. Although, the average coverage of relic zone is about 39%, 45 of the 1086 settlement territories used, have no relic zone. The largest proportion (up to 99% of the communal area) is found in territories along the southern periphery of Flanders region. The landscape relics mapped in the Landscape Atlas of Flanders correspond mainly to more stable landscapes in the periphery of communal territories and to settlements located in the periphery of the Flanders region.     

Effects of land and building usage on population,land price and passengers in station areas: A case study in Fukuoka,Japan

This study uses multiple regression to investigate the effects of land and building use on population, land price, and passengers. Initially, we abstract annual data on land and buildings usage within a radius of 0 m–400 m for railway stations and 400 m–800 m for subway stations in Fukuoka, Japan by using the GIS. We then analyze the relationships between 13 factors of land use and 8 factors of building usage, as well as the related population, land price, and passengers using the quantitative expression method. Using several categories of land use and building usage as explanatory variables, we analyze the degree to which the selected categories affect population, land price, and passengers by using the multiple regression method. This research can aid the further development of land and building usage in the future.     

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.     

Living in in-between spaces: A structure-agency analysis of the India–China and India–Bangladesh borderlands

Research on borderlands in recent years has emphasized the variation in how boundaries and borders operate for different groups of people and institutions in the era of globalization. Capital, goods, and people with resources inhabit an almost “borderless world.” In contrast, people in the less developed regions tend to experience borders more as barriers. Borders create different lived experience for people who reside in particular borderlands as distinctive in-between spaces. This paper contends to understand the formation of borderlands and their meanings in the current context of globalization, especially those created as part of colonization or the legacies thereof. We need to carefully analyze the embedded experience of inhabitants’ informal and fluid lived experiences that straddle national geopolitical disputes, local conflicts and negotiations, and in-between urban spaces characterized by what we call “relative urbanity”. We offer supporting evidence for this argument via a grounded analysis of the links and interactions between people living in and across two borderlands along China’s and Bangladesh’s boundaries with Eastern India—that were a creation of British colonial rule in India and have evolved with and beyond this colonial legacy.     

Modeling urban land development as a continuum to address fine-grained habitat heterogeneity

Natural landscapes are increasingly subjected to impacts associated with urbanization, resulting in loss and degradation of native ecosystems and biodiversity. Traditional classification approaches to the characterization of urbanization may prove inadequate in some human-modified landscapes where complex and unique combinations of conditions can make classification and delineation of patches difficult. We describe a model that depicts existing human development as a fine-grained continuous variable using parcel-based land use data and transportation networks. We derived percent development values across our 88 000-ha study area, the Lake Tahoe basin. Our modeled values were highly correlated with observed levels of development based on high-resolution aerial photographs. We demonstrate how our model of development can be used to address practical conservation questions by evaluating the potential effects of highly interspersed urban land development and wildland conditions on the amount and availability of habitat suitable for the resident California spotted owl (Strix occidentalis occidentalis) at two points in time (current and 40 years in the future). The results indicated that assessments not accounting for the indirect effects of development may overestimate the amount of available habitat by 19–83%. Portraying urbanization as a continuum across entire landscapes captured fine-grained landscape complexity at scales that were relevant to the habitat needs and environmental sensitivities of a species of conservation interest. This relatively simple approach should aid ecologists and landscape planners in evaluating the current or future effects of urbanization on ecological elements and processes.     

Possibility of using roof openings for natural ventilation in a shallow urban road tunnel

Naturally ventilated urban vehicular tunnels with multiple roof openings have increased in China. Unnecessary gas (polluted air or fire smoke) are expected to be exhausted out through openings. Whether its safety standards can be satisfied or not still needs to be verified. In this paper, a safe CO concentration was firstly discussed, and a heat risk level of very high to extreme up to 46 °C was given. Secondly, a real 1410 m tunnel was proposed, and a 1/10 scale model tunnel was reproduced. Ambient winds of 0.95 m/s in prototype and 0.3 m/s in model were considered. Under normal traffic test, a track circuit was constructed with model vehicles moving on it to form traffic wind, and once the air velocity was larger than 0.31 m/s, the airflows were found to be not relevant to the Reynolds number. The traffic winds were weakened by openings. For three of all tested traffic, the actual air velocities were larger than the required ones, so its air qualities were satisfied. In firing test, two sets of burning experiments were conducted with which the heat release rates (HRR) were 8.35 kW and 13.7 kW. Large amounts of smoke were exhausted out of openings, and the high-temperature was not significant. Full-scale numerical simulations were carried out to verify the experimental results respectively using Fluent 6.0 for normal traffic and FDS 4.07 for firing. The simulations were compared well with the experiments. Further FDS simulations show that the openings’ mass flow rates are influenced little by ambient temperature; with the increasing length of the buried section, much smoke accumulate inside leading to a high temperature; having 4–5 openings in one shaft group is oversize in the actual engineering design.     

Correlations among mechanical properties of steel fiber reinforced concrete

In this paper, applicability of previously published empirical relations among compressive strength, splitting tensile strength and flexural strength of normal concrete, polypropylene fiber reinforced concrete (PFRC) and glass fiber reinforced concrete (GFRC) to steel fiber reinforced concrete (SFRC) was evaluated; moreover, correlations among these mechanical properties of SFRC were analyzed. For the investigation, a large number of experimental data were collected from published literature, where water/binder ratio (w/b), steel fiber aspect ratio and volume fraction were reported in the general range of 0.25–0.5, 55–80 and 0.5–2.0%, respectively, and specimens were cylinders with size of Φ 150 × 300 mm and prisms with size of 150 × 150 × 500 mm. Results of evaluation on these published empirical relations indicate the inapplicability to SFRC, also confirm the necessity of determination on correlations among mechanical properties of SFRC. Through the regression analysis on the experimental data collected, power relations with coefficients of determination of 0.94 and 0.90 are obtained for SFRC between compressive strength and splitting tensile strength, and between splitting tensile strength and flexural strength, respectively.     

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).     

Service life prediction of a concrete bridge structure subjected to carbonation

Carbonation-induced corrosion in concrete may often occur in a high carbon dioxide environment. In this study, the risk of carbonation of a concrete bridge in an urban area was evaluated by measuring the carbonation rate and concrete cover depth in three different parts: the sound, cracked and construction joint parts of cover concrete. The average carbonation rate was ordered by the sound > joint > cracked parts, and the concrete cover depth measured by an ultrasonic detector indicated the slightly greater value than the designed one (50.0 mm). Then, the carbonation-free service life at the depth of the steel was calculated, based on in situ information, by the safety factor method and the Monte Carlo simulation. The service life calculated by the two methods was mostly identical. The sensitivity of the carbonation rate and concrete cover depth to the time to carbonation at the depth of the steel was mathematically determined.     

Permeability of high-performance concrete subjected to elevated temperature (600 °C)

Permeability is one of the most important parameters to quantify the durability of high-performance concrete. Permeability is closely related with the spalling phenomenon in concrete at elevated temperature. This parameter is commonly measured on non-thermally damaged specimens. This paper presents the results of an experimental investigation carried out to study the effect of elevated temperature on the permeability of high-performance concrete. For this purpose, three types of concrete mixtures were prepared: (i) control high-performance concrete; (ii) high-performance concrete incorporating polypropylene fibres; and (iii) high-performance concrete made with lightweight aggregates. A heating–cooling cycle was applied on 160 × 320 mm, 110 × 220 mm, and 150 × 300 mm cylindrical specimens. The maximum test temperature was kept as either 200 or 600 °C. After the thermal treatment, 65 mm thick slices were cut from each cylinder and dried prior to being subjected to permeability test. Results of thermal gradients in the concrete specimens during the heating–cooling cycles, compressive strength, and splitting tensile strength of concrete mixtures are also presented here. A relationship between the thermal damage indicators and permeability is presented.