Urban and built-up land area changes in the United States: an empirical investigation of determinants.

Treesearch

Ralph J. Alig; Robert G. Healy

1987-01-01

Conversion of commodity-producing rural lands to urban and other built-up uses received considerable attention in the professional literature and in the popular press in the early 1980s (U.S. Department of Agriculture and U.S. Council on Environmental Quality 1981 ; Fischel 1982; Raup 1980; Brown, et al. 1982). Although some have concluded that the forces encouraging...

A global fingerprint of macro-scale changes in urban structure from 1999 to 2009

NASA Astrophysics Data System (ADS)

Frolking, Steve; Milliman, Tom; Seto, Karen C.; Friedl, Mark A.

2013-06-01

Urban population now exceeds rural population globally, and 60-80% of global energy consumption by households, businesses, transportation, and industry occurs in urban areas. There is growing evidence that built-up infrastructure contributes to carbon emissions inertia, and that investments in infrastructure today have delayed climate cost in the future. Although the United Nations statistics include data on urban population by country and select urban agglomerations, there are no empirical data on built-up infrastructure for a large sample of cities. Here we present the first study to examine changes in the structure of the world’s largest cities from 1999 to 2009. Combining data from two space-borne sensors—backscatter power (PR) from NASA’s SeaWinds microwave scatterometer, and nighttime lights (NL) from NOAA’s defense meteorological satellite program/operational linescan system (DMSP/OLS)—we report large increases in built-up infrastructure stock worldwide and show that cities are expanding both outward and upward. Our results reveal previously undocumented recent and rapid changes in urban areas worldwide that reflect pronounced shifts in the form and structure of cities. Increases in built-up infrastructure are highest in East Asian cities, with Chinese cities rapidly expanding their material infrastructure stock in both height and extent. In contrast, Indian cities are primarily building out and not increasing in verticality. This new dataset will help characterize the structure and form of cities, and ultimately improve our understanding of how cities affect regional-to-global energy use and greenhouse gas emissions.

Universal scaling of the distribution of land in urban areas

NASA Astrophysics Data System (ADS)

Riascos, A. P.

2017-09-01

In this work, we explore the spatial structure of built zones and green areas in diverse western cities by analyzing the probability distribution of areas and a coefficient that characterize their respective shapes. From the analysis of diverse datasets describing land lots in urban areas, we found that the distribution of built-up areas and natural zones in cities obey inverse power laws with a similar scaling for the cities explored. On the other hand, by studying the distribution of shapes of lots in urban regions, we are able to detect global differences in the spatial structure of the distribution of land. Our findings introduce information about spatial patterns that emerge in the structure of urban settlements; this knowledge is useful for the understanding of urban growth, to improve existing models of cities, in the context of sustainability, in studies about human mobility in urban areas, among other applications.

Urbanization and Land Use Changes in Peri-Urban Area using Spatial Analysis Methods (Case Study: Ciawi Urban Areas, Bogor Regency)

NASA Astrophysics Data System (ADS)

Cahya, D. L.; Martini, E.; Kasikoen, K. M.

2018-02-01

Urbanization is shown by the increasing percentage of the population in urban areas. In Indonesia, the percentage of urban population increased dramatically form 17.42% (1971) to 42.15% (2010). This resulted in increased demand for housing. Limited land in the city area push residents looking for an alternative location of his residence to the peri-urban areas. It is accompanied by a process of land conversion from green area into built-up area. Continuous land conversion in peri-urban area is becoming increasingly widespread. Bogor Regency as part of the Jakarta Metropolitan Area is experiencing rapid development. This regency has been experienced land-use change very rapidly from agricultural areas into urban built up areas. Aim of this research is to analyze the effect of urbanization on land use changes in peri-urban areas using spatial analysis methods. This research used case study of Ciawi Urban Area that experiencing rapid development. Method of this research is using descriptive quantitative approach. Data used in this research is primary data (field survey) and secondary data (maps). To analyze land use change is using Geographic Information System (GIS) as spatial analysis methods. The effect of urbanization on land use changes in Ciawi Urban Area from year 2013 to 2015 is significant. The reduction of farm land is around -4.00% and wetland is around - 2.51%. The increasing area for hotel/villa/resort is around 3.10%. Based on this research, local government (Bogor Regency) should be alert to the land use changes that does not comply with the land use plan and also consistently apply the spatial planning.

The relationship between built-up areas and the spatial development of the mean maximum urban heat island in Debrecen, Hungary

NASA Astrophysics Data System (ADS)

Bottyán, Zsolt; Kircsi, Andrea; Szegedi, Sándor; Unger, János

2005-03-01

The climate of built-up regions differs significantly from rural regions and the most important modifying effect of urbanization on local climate is the urban temperature excess, otherwise called the urban heat island (UHI).This study examines the influence of built-up areas on the near-surface air temperature field in the case of the medium-sized city of Debrecen, Hungary. Mobile measurements were used under different weather conditions between March 2002 and March 2003. Efforts concentrated on the determination of the spatial distribution of mean maximum UHI intensity with special regard to land-use features such as built-up ratio and its areal extensions.In both (heating and non-heating) seasons the spatial distribution of the UHI intensity field showed a basically concentric shape with local anomalies. The mean maximum UHI intensity reaches more than 2.0 °C (heating season) and 2.5 °C (non-heating season) in the centre of the city. We established the relationship between the above-mentioned land-use parameters and mean maximum UHI intensity by means of multiple linear regression analysis. As the measured and predicted mean maximum UHI intensity patterns show, there is an obvious connection between the spatial distribution of urban thermal excess and the land-use parameters examined, so these parameters play a significant role in the development of the strong UHI intensity field over the city.

Cultural Ecosystem Services of Urban Green Spaces-Supply and Demand in The Densely Built-Up Areas. Poznan Old Town Case Study

NASA Astrophysics Data System (ADS)

Ponizy, Lidia; Majchrzak, Weronika; Zwierzchowska, Iwona

2017-12-01

The quality of life of big city dwellers depends on the use of green infrastructure. The idea of a compact city, opposed to urban sprawl, can lead to reduced access to green areas and increased demand for cultural services provided through urban green infrastructure. Considering the above, the aim of the paper was to identify the supply of and demand for cultural ecosystem services related to the urban green spaces in densely built-up urban areas. To find out how important the ability to use green areas for dwellers of the densely built-up areas is, the questionnaire interviews with the residents of the area of the Old Town of Poznan were conducted. Questions in the survey concerned the amount of green spaces and their availability, the way of use, types of activity, factors limiting the use and factors encouraging to visit green spaces and the motives for using green areas away from inhabitants’ place of residence. Respondents claim that there is not enough greenery, especially associated with housing and street side greenery; the amount of parks (which they use most) is slightly higher, in their opinion. Limitations that influence utilising green spaces concern both greenery itself (e.g. insufficient recreational infrastructure, neglected green areas) as well as respondent’s issues (e.g. lack of free time). Improvements to recreational infrastructure and more well-kept green spaces would encourage respondents to utilise it more often. Active participation of inhabitants in developing and maintaining their closest neighbourhood would allow to enlarge green spaces in housing areas and make them more customized to the residents’ needs and requirements in terms of functionality and aesthetic.

Measuring Land Change in Coastal Zone around a Rapidly Urbanized Bay.

PubMed

Huang, Faming; Huang, Boqiang; Huang, Jinliang; Li, Shenghui

2018-05-23

Urban development is a major cause for eco-degradation in many coastal regions. Understanding urbanization dynamics and underlying driving factors is crucial for urban planning and management. Land-use dynamic degree indices and intensity analysis were used to measure land changes occurred in 1990, 2002, 2009, and 2017 in the coastal zone around Quanzhou bay, which is a rapidly urbanized bay in Southeast China. The comprehensive land-use dynamic degree and interval level intensity analysis both revealed that land change was accelerating across the three time intervals in a three-kilometer-wide zone along the coastal line (zone A), while land change was fastest during the second time interval 2002⁻2009 in a separate terrestrial area within coastal zone (zone B). Driven by urbanization, built-up gains and cropland losses were active for all time intervals in both zones. Mudflat losses were active except in the first time interval in zone A due to the intensive sea reclamation. The gain of mangrove was active while the loss of mangrove is dormant for all three intervals in zone A. Transition level analysis further revealed the similarities and differences in processes within patterns of land changes for both zones. The transition from cropland to built-up was systematically targeted and stationary while the transition from woodland to built-up was systematically avoiding transition in both zones. Built-up tended to target aquaculture for the second and third time intervals in zone A but avoid Aquaculture for all intervals in zone B. Land change in zone A was more significant than that in zone B during the second and third time intervals at three-level intensity. The application of intensity analysis can enhance our understanding of the patterns and processes in land changes and suitable land development plans in the Quanzhou bay area. This type of investigation is useful to provide information for developing sound land use policy to achieve urban sustainability in similar coastal areas.

Four decades urban growth and land use change in Samara Russia through remote sensing and GIS techniques

NASA Astrophysics Data System (ADS)

Boori, Mukesh Singh; Choudhary, Komal; Kupriyanov, Alexander; Kovelskiy, Viktor

2015-12-01

This study illustrates the spatio-temporal dynamics of urban growth and land use changes in Samara city, Russia from 1975 to 2015. Landsat satellite imageries of five different time periods from 1975 to 2015 were acquired and quantify the changes with the help of ArcGIS 10.1 Software. By applying classification methods to the satellite images four main types of land use were extracted: water, built-up, forest and grassland. Then, the area coverage for all the land use types at different points in time were measured and coupled with population data. The results demonstrate that, over the entire study period, population was increased from 1146 thousand people to 1244 thousand from 1975 to 1990 but later on first reduce and then increase again, now 1173 thousand population. Built-up area is also change according to population. The present study revealed an increase in built-up by 37.01% from 1975 to 1995, than reduce -88.83% till 2005 and an increase by 39.16% from 2005 to 2015, along with the increase in population, migration from rural areas owing to the economic growth and technological advantages associated with urbanization. Information on urban growth, land use and land cover change study is very useful to local government and urban planners for the betterment of future plans to sustainable development of the city.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, zhifeng; He, Chunyang; Zhou, Yuyu

Urbanization has transformed the world’s landscapes, resulting in a series of ecological and environmental problems. To assess urbanization impacts and improve sustainability, one of the first questions that we must address is: how much of the world’s land has been urbanized? Unfortunately, the estimates of the global urban land reported in the literature vary widely from less than 1% to 3% primarily because different definitions of urban land were used. To evade confusion, here we propose a hierarchical framework for representing and communicating the spatial extent of the world’s urbanized land at the global, regional, and more local levels. Themore » hierarchical framework consists of three spatially nested definitions: “urban area” that is delineated by administrative boundaries, “built-up area” that is dominated by artificial surfaces, and “impervious surface area” that is devoid of life. These are really three different measures of urbanization. In 2010, the global urban land was close to 3%, the global built-up area was 0.65%, and the global impervious surface area was 0.45%, of the word’s total land area (excluding Antarctica and Greenland). We argue that this hierarchy of urban land measures, in particular the ratios between them, can also facilitate better understanding the biophysical and socioeconomic processes and impacts of urbanization.« less

Mapping and Evaluating the Urbanization Process in Northeast China Using DMSP/OLS Nighttime Light Data

PubMed Central

Yi, Kunpeng; Tani, Hiroshi; Li, Qiang; Zhang, Jiquan; Guo, Meng; Bao, Yulong; Wang, Xiufeng; Li, Jing

2014-01-01

In this paper, an Urban Light Index (ULI) is constructed to facilitate analysis and quantitative evaluation of the process of urbanization and expansion rate by using DMSP/OLS Nighttime Light Data during the years from 1992 to 2010. A unit circle urbanization evaluation model is established to perform a comprehensive analysis of the urbanization process of 34 prefecture-level cities in Northeast China. Furthermore, the concept of urban light space is put forward. In this study, urban light space is divided into four types: the core urban area, the transition zone between urban and suburban areas, suburban area and fluorescent space. Proceeding from the temporal and spatial variation of the four types of light space, the pattern of morphologic change and space-time evolution of the four principal cities in Northeast China (Harbin, Changchun, Shenyang, Dalian) is analyzed and given particular attention. Through a correlation analysis between ULI and the traditional urbanization indexes (urban population, proportion of the secondary and tertiary industries in the regional GDP and the built-up area), the advantages and disadvantages as well as the feasibility of using the ULI in the study of urbanization are evaluated. The research results show that ULI has a strong correlation with urban built-up area (R2 = 0.8277). The morphologic change and history of the evolving urban light space can truly reflect the characteristics of urban sprawl. The results also indicate that DMSP/OLS Nighttime Light Data is applicable for extracting urban space information and has strong potential to urbanization research. PMID:24553086

Joint Urban Operations Joint Integrating Concept

DTIC Science & Technology

2007-07-23

24 7. Potential Risks of Adopting this Concept...stresses that urban combat operations are conducted only when required and that built-up areas are isolated and bypassed rather than risking a...Development, Applications (New York: George Braziller , 1968). 7 media, etc., institutions that typify urban society.15 The processes include all

Characterization and spatial modeling of urban sprawl in the Wuhan Metropolitan Area, China

NASA Astrophysics Data System (ADS)

Zeng, Chen; Liu, Yaolin; Stein, Alfred; Jiao, Limin

2015-02-01

Urban sprawl has led to environmental problems and large losses of arable land in China. In this study, we monitor and model urban sprawl by means of a combination of remote sensing, geographical information system and spatial statistics. We use time-series data to explore the potential socio-economic driving forces behind urban sprawl, and spatial models in different scenarios to explore the spatio-temporal interactions. The methodology is applied to the city of Wuhan, China, for the period from 1990 to 2013. The results reveal that the built-up land has expanded and has dispersed in urban clusters. Population growth, and economic and transportation development are still the main causes of urban sprawl; however, when they have developed to certain levels, the area affected by construction in urban areas (Jian Cheng Qu (JCQ)) and the area of cultivated land (ACL) tend to be stable. Spatial regression models are shown to be superior to the traditional models. The interaction among districts with the same administrative status is stronger than if one of those neighbors is in the city center and the other in the suburban area. The expansion of urban built-up land is driven by the socio-economic development at the same period, and greatly influenced by its spatio-temporal neighbors. We conclude that the integration of remote sensing, a geographical information system, and spatial statistics offers an excellent opportunity to explore the spatio-temporal variation and interactions among the districts in the sprawling metropolitan areas. Relevant regulations to control the urban sprawl process are suggested accordingly.

Analysis of land cover/use changes using Landsat 5 TM data and indices.

PubMed

Ettehadi Osgouei, Paria; Kaya, Sinasi

2017-04-01

Urban expansion and unprecedented rural to urban transition, along with a huge population growth, are major driving forces altering land cover/use in metropolitan areas. Many of the land cover classes such as farmlands, wetlands, forests, and bare soils have been transformed during the past years into human settlements. Identification of the city growth trends and the impact of it on the vegetation cover of an area is essential for a better understanding of the sustainability of urban development processes, both planned and unplanned. Analyzing the causes and consequences of land use dynamics helps local government, urban planners, and managers for the betterment of future plans and minimizing the negative effects.This study determined temporal changes in vegetation cover and built-up area in Istanbul (Turkey) using the normalized difference vegetation index (NDVI), soil-adjusted vegetation index (SAVI), and built-up area index (BUAI). The temporal data were based on Landsat 5 Thematic Mapper (TM) images acquired in June of 1984, 2002, 2007, 2009, and 2011. The NDVI was applied to all the Landsat images, and the resulting NDVI images were overlaid to generate an NDVI layer stack image. The same procedure was repeated using the SAVI and BUAI images. The layer stack images revealed those areas that had changed in terms of the different indices over the years. To determine temporal change trends, the values of 150 randomly selected control points were extracted from the same locations in the NDVI, SAVI, and BUAI layer stack images. The results obtained from these control points showed that vegetation cover decreased considerably because of a remarkable increase in the built-up area.

Monitoring of "urban villages" in Shenzhen, China from high-resolution GF-1 and TerraSAR-X data

NASA Astrophysics Data System (ADS)

Wei, Chunzhu; Blaschke, Thomas; Taubenböck, Hannes

2015-10-01

Urban villages comprise mainly low-rise and congested, often informal settlements surrounded by new constructions and high-rise buildings whereby structures can be very different between neighboring areas. Monitoring urban villages and analyzing their characteristics are crucial for urban development and sustainability research. In this study, we carried out a combined analysis of multispectral GaoFen-1 (GF-1) and high resolution TerraSAR-X radar (TSX) imagery to extract the urban village information. GF-1 and TSX data are combined with the Gramshmidt spectral sharpening method so as to provide new input data for urban village classification. The Grey-Level Co-occurrence Matrix (GLCM) approach was also applied to four directions to provide another four types (all, 0°, 90°, 45° directions) of TSX-based inputs for urban village detection. We analyzed the urban village mapping performance using the Random Forest approach. The results demonstrate that the best overall accuracy and the best producer accuracy of urban villages reached with the GLCM 90° dataset (82.33%, 68.54% respectively). Adding single polarization TSX data as input information to the optical image GF-1 provided an average product accuracy improvement of around 7% in formal built-up area classification. The SAR and optical fusion imagery also provided an effective means to eliminate some layover, shadow effects, and dominant scattering at building locations and green spaces, improving the producer accuracy by 7% in urban area classification. To sum up, the added value of SAR information is demonstrated by the enhanced results achievable over built-up areas, including formal and informal settlements.

Urbanization Process Monitoring in Northwest China based on DMSP/OLS Nighttime Light Data

NASA Astrophysics Data System (ADS)

Wang, K.; Bai, L. Y.; Feng, J. Z.

2017-02-01

In recent years, the DMSP/OLS nighttime light data have been widely applied to various fields such as monitoring and evaluation of urbanization, estimation of social economy, economical environment and health effects, hazards analysis, and fisheries research. The general urbanized level in China has rapidly developed since the 1990s, and the cities in northwest China, which were important population centres of the ancient silk road, have also been developed in a high speed thanks to China’s national strategy of Western Development. Given the Xinjiang autonomous region as a core area of One Belt and One Road, it is very necessary to study the urbanization processes and changes of its urban system and the whole northwest region of China. In this paper, we extracted built-up areas of the cities in northwest China in 1992, 1997, 2002, 2007, and 2012, evaluated urban expansion and spatial pattern through appropriate indexes, and also quantitatively analyzed the urbanized level of each city. The results showed that the cities in northwest China generally presented high strong and rapid expansion, but there were some large differences among cities. Urban expansion forms alternate with exterior expansion and interior filling, in general, the cities externally expandedafter 2002 and internally filledbefore 2002, meanwhile, there were a high positive correlation between urban built-up areas and population growth in Xinjiang autonomous.

Evaluating the compatibility of multi-functional and intensive urban land uses

NASA Astrophysics Data System (ADS)

Taleai, M.; Sharifi, A.; Sliuzas, R.; Mesgari, M.

2007-12-01

This research is aimed at developing a model for assessing land use compatibility in densely built-up urban areas. In this process, a new model was developed through the combination of a suite of existing methods and tools: geographical information system, Delphi methods and spatial decision support tools: namely multi-criteria evaluation analysis, analytical hierarchy process and ordered weighted average method. The developed model has the potential to calculate land use compatibility in both horizontal and vertical directions. Furthermore, the compatibility between the use of each floor in a building and its neighboring land uses can be evaluated. The method was tested in a built-up urban area located in Tehran, the capital city of Iran. The results show that the model is robust in clarifying different levels of physical compatibility between neighboring land uses. This paper describes the various steps and processes of developing the proposed land use compatibility evaluation model (CEM).

Integrated Evaluation of Coupling Coordination for Land Use Change and Ecological Security: A Case Study in Wuhan City of Hubei Province, China

PubMed Central

Wang, Zhanqi; Zhang, Hongwei

2017-01-01

As land resources and ecosystems provide necessary materials and conditions for human development, land use change and ecological security play increasingly important roles in sustainable development. This study aims to reveal the mutual-influence and interaction between land use change and ecological security in Wuhan, based on the coupling coordination degree model. As such, it provides strategies for the achievement of the synchronous and coordinated development of urbanization and ecological security. The results showed that, during the period from 2006 to 2012, the size of built-up area in Wuhan increased to 26.16%, and that all the other types of land use reduced due to the urbanization process, which appeared to be the main driving force of land use change. The ecological security in Wuhan has been improving as a whole although it was somewhat held back from 2006 to 2008 due to the rapid growth of built-up area. The coupling coordination analysis revealed that the relationship between built-up area and ecological security was more coordinated after 2008. The results can provide feasible recommendations for land use management and environmental protection from the viewpoint of coordinated development. To achieve sustainable development from economic and ecological perspective, policy makers should control the rate of urban expansion and exert more effort on intensive land use, clean energy development and emission reduction. PMID:29165365

Integrated Evaluation of Coupling Coordination for Land Use Change and Ecological Security: A Case Study in Wuhan City of Hubei Province, China.

PubMed

Chai, Ji; Wang, Zhanqi; Zhang, Hongwei

2017-11-22

As land resources and ecosystems provide necessary materials and conditions for human development, land use change and ecological security play increasingly important roles in sustainable development. This study aims to reveal the mutual-influence and interaction between land use change and ecological security in Wuhan, based on the coupling coordination degree model. As such, it provides strategies for the achievement of the synchronous and coordinated development of urbanization and ecological security. The results showed that, during the period from 2006 to 2012, the size of built-up area in Wuhan increased to 26.16%, and that all the other types of land use reduced due to the urbanization process, which appeared to be the main driving force of land use change. The ecological security in Wuhan has been improving as a whole although it was somewhat held back from 2006 to 2008 due to the rapid growth of built-up area. The coupling coordination analysis revealed that the relationship between built-up area and ecological security was more coordinated after 2008. The results can provide feasible recommendations for land use management and environmental protection from the viewpoint of coordinated development. To achieve sustainable development from economic and ecological perspective, policy makers should control the rate of urban expansion and exert more effort on intensive land use, clean energy development and emission reduction.

Urban Flow and Pollutant Dispersion Simulation with Multi-scale coupling of Meteorological Model with Computational Fluid Dynamic Analysis

NASA Astrophysics Data System (ADS)

Liu, Yushi; Poh, Hee Joo

2014-11-01

The Computational Fluid Dynamics analysis has become increasingly important in modern urban planning in order to create highly livable city. This paper presents a multi-scale modeling methodology which couples Weather Research and Forecasting (WRF) Model with open source CFD simulation tool, OpenFOAM. This coupling enables the simulation of the wind flow and pollutant dispersion in urban built-up area with high resolution mesh. In this methodology meso-scale model WRF provides the boundary condition for the micro-scale CFD model OpenFOAM. The advantage is that the realistic weather condition is taken into account in the CFD simulation and complexity of building layout can be handled with ease by meshing utility of OpenFOAM. The result is validated against the Joint Urban 2003 Tracer Field Tests in Oklahoma City and there is reasonably good agreement between the CFD simulation and field observation. The coupling of WRF- OpenFOAM provide urban planners with reliable environmental modeling tool in actual urban built-up area; and it can be further extended with consideration of future weather conditions for the scenario studies on climate change impact.

Comparison Between Spectral, Spatial and Polarimetric Classification of Urban and Periurban Landcover Using Temporal Sentinel - 1 Images

NASA Astrophysics Data System (ADS)

Roychowdhury, K.

2016-06-01

Landcover is the easiest detectable indicator of human interventions on land. Urban and peri-urban areas present a complex combination of landcover, which makes classification challenging. This paper assesses the different methods of classifying landcover using dual polarimetric Sentinel-1 data collected during monsoon (July) and winter (December) months of 2015. Four broad landcover classes such as built up areas, water bodies and wetlands, vegetation and open spaces of Kolkata and its surrounding regions were identified. Polarimetric analyses were conducted on Single Look Complex (SLC) data of the region while ground range detected (GRD) data were used for spectral and spatial classification. Unsupervised classification by means of K-Means clustering used backscatter values and was able to identify homogenous landcovers over the study area. The results produced an overall accuracy of less than 50% for both the seasons. Higher classification accuracy (around 70%) was achieved by adding texture variables as inputs along with the backscatter values. However, the accuracy of classification increased significantly with polarimetric analyses. The overall accuracy was around 80% in Wishart H-A-Alpha unsupervised classification. The method was useful in identifying urban areas due to their double-bounce scattering and vegetated areas, which have more random scattering. Normalized Difference Built-up index (NDBI) and Normalized Difference Vegetation Index (NDVI) obtained from Landsat 8 data over the study area were used to verify vegetation and urban classes. The study compares the accuracies of different methods of classifying landcover using medium resolution SAR data in a complex urban area and suggests that polarimetric analyses present the most accurate results for urban and suburban areas.

Modelling reduction of urban heat load in Vienna by modifying surface properties of roofs

NASA Astrophysics Data System (ADS)

Žuvela-Aloise, Maja; Andre, Konrad; Schwaiger, Hannes; Bird, David Neil; Gallaun, Heinz

2018-02-01

The study examines the potential of urban roofs to reduce the urban heat island (UHI) effect by changing their reflectivity and implementing vegetation (green roofs) using the example of the City of Vienna. The urban modelling simulations are performed based on high-resolution orography and land use data, climatological observations, surface albedo values from satellite imagery and registry of the green roof potential in Vienna. The modelling results show that a moderate increase in reflectivity of roofs (up to 0.45) reduces the mean summer temperatures in the densely built-up environment by approximately 0.25 °C. Applying high reflectivity materials (roof albedo up to 0.7) leads to average cooling in densely built-up area of approximately 0.5 °C. The green roofs yield a heat load reduction in similar order of magnitude as the high reflectivity materials. However, only 45 % of roof area in Vienna is suitable for greening and the green roof potential mostly applies to industrial areas in city outskirts and is therefore not sufficient for substantial reduction of the UHI effect, particularly in the city centre which has the highest heat load. The strongest cooling effect can be achieved by combining the green roofs with high reflectivity materials. In this case, using 50 or 100 % of the green roof potential and applying high reflectivity materials on the remaining surfaces have a similar cooling effect.

Assessing land take by urban development and its impact on carbon storage: Findings from two case studies in Italy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sallustio, L.; Quatrini, V.; Geneletti, D., E-mail: davide.geneletti@unitn.it

Highlights: • We tested a new methodology for monitoring land take and its effects on C storage. • The ecological impact of urban growth derives from the previous land use. • C loss increases with the naturalness of the territory. • Different urban assets may imply different forms of land take containment. Land take due to urbanization triggers a series of negative environmental impacts with direct effects on quality of life for people living in cities. Changes in ecosystem services are associated with land take, among which is the immediate C loss due to land use conversion. Land use changemore » monitoring represents the first step in quantifying land take and its drivers and impacts. To this end, we propose an innovative methodology for monitoring land take and its effects on ecosystem services (in particular, C loss) under multi-scale contexts. The devised approach was tested in two areas with similar sizes, but different land take levels during the time-span 1990–2008 in Central Italy (the Province of Rome and the Molise Region). The estimates of total coverage of built up areas were calculated using point sampling. The area of the urban patches including each sampling point classified as built up areas in the year 1990 and/or in the year 2008 is used to estimate total abundance and average area of built up areas. Biophysical and economic values for carbon loss associated with land take were calculated using InVEST. Although land take was 7–8 times higher in the Province of Rome (from 15.1% in 1990 to 20.4% in 2008) than in Molise region, our findings show that its relative impact on C storage is higher in the latter, where the urban growth consistently affects not only croplands but also semi-natural land uses such as grasslands and other wooded lands. The total C loss due to land take has been estimated in 1.6 million Mg C, corresponding to almost 355 million €. Finally, the paper discusses the main characteristics of urban growth and their ecological impact leading to risks and challenges for future urban planning and land use policies.« less

Developed land cover of Puerto Rico

Treesearch

William A. Gould; Sebastian Martinuzzi; Olga M. Ramos Gonzalez

2008-01-01

This map shows the distribution of developed land cover in Puerto Rico (Martinuzzi et al. 2007). Developed land cover refers to urban, built-up and non-vegetated areas that result from human activity. These typically include built structures, concrete, asphalt, and other infrastructure. The developed land cover was estimated using Landsat 7 ETM+ satellite images pan...

Construction Land Expansion and Transfer of Gravity Center from 1984 to 2016 : A study on Beijing - Tianjin - Hebei Urban Agglomeration

NASA Astrophysics Data System (ADS)

Lv, Jinxia; Jiang, Weiguo

2017-04-01

With the economic development and technological innovation, urban planning and construction has already broken through the shackles of the natural conditions such as topography and geomorphology, and the social factors such as politics and location have been affected by the urbanization process in the process of urbanization. At the same time, the synergies between urban development and local economy, national policy, industrial distribution and so on are also paid more attention. As the third pole of Chinese economy after the Pearl River Delta and the Yangtze River Delta, the Beijing-Tianjin-Hebei Metropolis Circle has attracted extensive attention on experts and scholars in its urban development and location. In recent years, studies on urban development have not only analyzed the spatial characteristics of urban or urban agglomerations, but also discussed the relationship between urban development and certain elements or phenomena. This paper presents a multi-threshold and multi-feature extraction method for building land using the optical characteristics of different landforms, based on Landsat remote sensing images from 1984 to 2016. The method selected Automated Water Extraction Index (AWEI), Normalized Difference Vegetation Index (NDVI), Soil Extraction Index (SOEI) and Normalized Difference Built-up Index (BUEI) to extract the construction land. It is an example study area of Beijing to extract the construction land in 30 years and to do a examine research. Using the ArcGIS software to calculate, we can get the coordinates of the city center of gravity in Beijing in various years. It can be seen that the center of gravity of built-up area and the movement of the center of gravity in Beijing. The results showed that the construction land in Beijing has an increasing tendency in recent 30 years. The main characteristic of expansion is the way of high-speed outward development. From 1984 to 1999, the center of gravity of the city shifted to the northeast, and from 2000 to 2016 the center of gravity shifted to the southeast. In the further study, we would do a research in the whole area in Beijing-Tianjin-Hebei and pay more attention to built-up land expansion prediction.

The role of green corridors for wildlife conservation in urban landscape: A literature review

NASA Astrophysics Data System (ADS)

Aziz, H. A.; Rasidi, M. H.

2014-02-01

Green corridors are an attempt to mitigate negative effects of the built environment of cities and towns. The corridors act as conservation for rapidly extreme intervention and development of the urban environment. Most importantly, it enables dispersal movement of animals within city areas. Issues relate to wildlife conservation in urban areas has been studied for many years and thus, the research makes a review for how the green corridors contribute to the conservation of urban wildlife. This study reviews groups of articles in disciplines of urban landscape planning and biology conservation to discuss the relationship between elements of green corridors and urban wildlife dispersal movement behaviour in Malaysian context. Accordingly, this research is purposely studied to give understanding on how green corridors contribute to the animals' ability of moving and dispersing within the built-up areas. In advance, it is found that there are three factors contribute to the capability of colonization among urban wildlife which are individual, physical and social factor. Green corridor has been defined as one of the physical factor that influence urban wildlife behaviour movement. Consequently, safety area indicating to animals species for traversing in any time such as at night can be defined as the primary potential corridor.

Urban climate effects on extreme temperatures in Madison, Wisconsin, USA

NASA Astrophysics Data System (ADS)

Schatz, Jason; Kucharik, Christopher J.

2015-09-01

As climate change increases the frequency and intensity of extreme heat, cities and their urban heat island (UHI) effects are growing, as are the urban populations encountering them. These mutually reinforcing trends present a growing risk for urban populations. However, we have limited understanding of urban climates during extreme temperature episodes, when additional heat from the UHI may be most consequential. We observed a historically hot summer and historically cold winter using an array of up to 150 temperature and relative humidity sensors in and around Madison, Wisconsin, an urban area of population 402 000 surrounded by lakes and a rural landscape of agriculture, forests, wetlands, and grasslands. In the summer of 2012 (third hottest since 1869), Madison’s urban areas experienced up to twice as many hours ⩾32.2 °C (90 °F), mean July TMAX up to 1.8 °C higher, and mean July TMIN up to 5.3 °C higher than rural areas. During a record setting heat wave, dense urban areas spent over four consecutive nights above the National Weather Service nighttime heat stress threshold of 26.7 °C (80 °F), while rural areas fell below 26.7 °C nearly every night. In the winter of 2013-14 (coldest in 35 years), Madison’s most densely built urban areas experienced up to 40% fewer hours ⩽-17.8 °C (0 °F), mean January TMAX up to 1 °C higher, and mean January TMIN up to 3 °C higher than rural areas. Spatially, the UHI tended to be most intense in areas with higher population densities. Temporally, both daytime and nighttime UHIs tended to be slightly more intense during more-extreme heat days compared to average summer days. These results help us understand the climates for which cities must prepare in a warming, urbanizing world.

A New Automatic Method of Urban Areas Mapping in East Asia from LANDSAT Data

NASA Astrophysics Data System (ADS)

XU, R.; Jia, G.

2012-12-01

Cities, as places where human activities are concentrated, account for a small percent of global land cover but are frequently cited as the chief causes of, and solutions to, climate, biogeochemistry, and hydrology processes at local, regional, and global scales. Accompanying with uncontrolled economic growth, urban sprawl has been attributed to the accelerating integration of East Asia into the world economy and involved dramatic changes in its urban form and land use. To understand the impact of urban extent on biogeophysical processes, reliable mapping of built-up areas is particularly essential in eastern cities as a result of their characteristics of smaller patches, more fragile, and a lower fraction of the urban landscape which does not have natural than in the West. Segmentation of urban land from other land-cover types using remote sensing imagery can be done by standard classification processes as well as a logic rule calculation based on spectral indices and their derivations. Efforts to establish such a logic rule with no threshold for automatically mapping are highly worthwhile. Existing automatic methods are reviewed, and then a proposed approach is introduced including the calculation of the new index and the improved logic rule. Following this, existing automatic methods as well as the proposed approach are compared in a common context. Afterwards, the proposed approach is tested separately in cities of large, medium, and small scale in East Asia selected from different LANDSAT images. The results are promising as the approach can efficiently segment urban areas, even in the presence of more complex eastern cities. Key words: Urban extraction; Automatic Method; Logic Rule; LANDSAT images; East AisaThe Proposed Approach of Extraction of Urban Built-up Areas in Guangzhou, China

Large-area settlement pattern recognition from Landsat-8 data

NASA Astrophysics Data System (ADS)

Wieland, Marc; Pittore, Massimiliano

2016-09-01

The study presents an image processing and analysis pipeline that combines object-based image analysis with a Support Vector Machine to derive a multi-layered settlement product from Landsat-8 data over large areas. 43 image scenes are processed over large parts of Central Asia (Southern Kazakhstan, Kyrgyzstan, Tajikistan and Eastern Uzbekistan). The main tasks tackled by this work include built-up area identification, settlement type classification and urban structure types pattern recognition. Besides commonly used accuracy assessments of the resulting map products, thorough performance evaluations are carried out under varying conditions to tune algorithm parameters and assess their applicability for the given tasks. As part of this, several research questions are being addressed. In particular the influence of the improved spatial and spectral resolution of Landsat-8 on the SVM performance to identify built-up areas and urban structure types are evaluated. Also the influence of an extended feature space including digital elevation model features is tested for mountainous regions. Moreover, the spatial distribution of classification uncertainties is analyzed and compared to the heterogeneity of the building stock within the computational unit of the segments. The study concludes that the information content of Landsat-8 images is sufficient for the tested classification tasks and even detailed urban structures could be extracted with satisfying accuracy. Freely available ancillary settlement point location data could further improve the built-up area classification. Digital elevation features and pan-sharpening could, however, not significantly improve the classification results. The study highlights the importance of dynamically tuned classifier parameters, and underlines the use of Shannon entropy computed from the soft answers of the SVM as a valid measure of the spatial distribution of classification uncertainties.

Multitemporal mapping of peri-urban carbon stocks and soil sealing from satellite data.

PubMed

Villa, Paolo; Malucelli, Francesco; Scalenghe, Riccardo

2018-01-15

Peri-urbanisation is the expansion of compact urban areas towards low-density settlements. This phenomenon directly challenges the agricultural landscape multifunctionality, including its carbon (C) storage capacity. Using satellite data, we mapped peri-urban C stocks in soil and built-up surfaces over three areas from 1993 to 2014 in the Emilia-Romagna region, Italy: a thinly populated area around Piacenza, an intermediate-density area covering the Reggio Emilia-Modena conurbation and a densely anthropized area developing along the coast of Rimini. Satellite-derived maps enabled the quantitative analysis of spatial and temporal features of urban growth and soil sealing, expressed as the ratio between C in built-up land and organic C in soils (Cc/Co). The three areas show substantial differences in C stock balance and soil sealing evolution. In Piacenza (Cc/Co=0.07 in 1993), although questioned by late industrial expansion and connected residential sprawl (Cc/Co growth by 38%), most of the new urbanisation spared the best rural soils. The Reggio Emilia-Modena conurbation, driven by the polycentricism of the area and the heterogeneity of economic sectors (Cc/Co rising from 0.08 to 0.14 from 1993 to 2014), balances sprawl and densification. Rimini, severely sealed since the 1960s (Cc/Co=0.23 in 1993), densifies its existing settlements and develops an industrial expansion of the hinterland, with Cc/Co growth accelerating from +15% before 2003 to +36% for the last decade. Copyright © 2017 Elsevier B.V. All rights reserved.

Impacts of housing development on nutrients flow along canals in a peri-urban area of Bangkok, Thailand.

PubMed

Honda, R; Hara, Y; Sekiyama, M; Hiramatsu, A

2010-01-01

Change of nutrients load and flow according to land-use change induced by housing development was investigated in Bang Yai, Nonthaburi, Thailand, which located in the peri-urban area of Bangkok. Each house in the newly developed residential community was regulated to be equipped with a septic tank to collect night soil. However, greywater and leachate from the septic tank was collected by a community sewage system and discharged into the canals with insufficient treatment, while the canals still function as infrastructure for irrigation and transportation. In the study area, built-up area became 1.4 times and agricultural fields decreased by 13% from 2003 until 2007. Total nutrients load to the canals was increased by 25% as nitrogen and 14% as phosphorus according to the increase of built-up area. Net nutrients load from agricultural fields was largely set off when we evaluated nutrients inflow from the canals to the agricultural field through irrigation. Consequently, nutrients load from domestic wastewater accounted most of net nutrients load into the canal.

Data on spatiotemporal urban sprawl of Dire Dawa City, Eastern Ethiopia.

PubMed

Taffa, Chaltu; Mekonen, Teferi; Mulugeta, Messay; Tesfaye, Bechaye

2017-06-01

The data presented in this paper shows the spatiotemporal expansion of Dire Dawa City (eastern Ethiopia) and the ensuing land use land cover changes in its peri-urban areas between 1985 and 2015. The data were generated from satellite images of Thematic Mapper (TM), Enhanced Thematic Mapper-Plus (ETM+) and OLI (Operational Land Image) with path/raw value of 166/053 by using Arc GIS 10.1 software. The precision of the images was verified by geolocation data collected from ground control points by using Geographic Positioning System (GPS) receiver. Four LULC classes (built up area, vegetation, barren land and farmland) with their respective spatiotemporal dimensions were clearly identified in the analysis. Built up area had shown an overall annual increment of 15.8% (82 ha per year) from 517 ha in 1985 to 2976 ha in 2015. Expansion took place in all directions but it was more pronounced along the main road towards other nearby towns, recently established business/service areas and the Industrial Park. Barren land, farmland and vegetation areas showed speedy decline over the years.

Comparing production function models for wildfire risk analysis in the wildland-urban interface

Treesearch

D. Evan Mercer; Jeffrey P. Prestemon

2005-01-01

Wildfires create damages in the wildland-urban interface (WUI) that total hundreds of millions of dollars annually in the United States. Understanding how fires are produced in built-up areas near and within fire prone landscapes requires evaluating and quantifling the roles that humans play in fire regimes. We outline a typology of wildfire production functions (WPFs...

An equilibrium analysis of the land use structure in the Yunnan Province, China

NASA Astrophysics Data System (ADS)

van Aken, H. M.; van Veldhoven, A. K.; Veth, C.; de Ruijter, W. P. M.; van Leeuwen, P. J.; Drijfhout, S. S.; Whittle, C. P.; Rouault, M.

2014-06-01

Global land use structure is changing rapidly due to unceasing population growth and accelerated urbanization, which leads to fierce competition between the rigid demand for built-up area and the protection of cultivated land, forest, and grassland. It has been a great challenge to realize the sustainable development of land resources. Based on a computable general equilibrium model of land use change with a social accounting matrix dataset, this study implemented an equilibrium analysis of the land use structure in the Yunnan Province during the period of 2008-2020 under three scenarios, the baseline scenario, low TFP (total factor productivity) scenario, and high TFP scenario. The results indicated that under all three scenarios, area of cultivated land declined significantly along with a remarkable expansion of built-up area, while areas of forest, grassland, and unused land increased slightly. The growth rate of TFP had first negative and then positive effects on the expansion of built-up area and decline of cultivated land as it increased. Moreover, the simulated changes of both cultivated land and built-up area were the biggest under the low TFP scenario, and far exceeded the limit in the Overall Plan for Land Utilization in the Yunnan Province in 2020. The scenario-based simulation results are of important reference value for policy-makers in making land use decisions, balancing the fierce competition between the protection of cultivated land and the increasing demand for built-up area, and guaranteeing food security, ecological security, and the sustainable development of land resources.

An equilibrium analysis of the land use structure in the Yunnan Province, China

NASA Astrophysics Data System (ADS)

Luo, Jiao; Zhan, Jinyan; Lin, Yingzhi; Zhao, Chunhong

2014-09-01

Global land use structure is changing rapidly due to unceasing population growth and accelerated urbanization, which leads to fierce competition between the rigid demand for built-up area and the protection of cultivated land, forest, and grassland. It has been a great challenge to realize the sustainable development of land resources. Based on a computable general equilibrium model of land use change with a social accounting matrix dataset, this study implemented an equilibrium analysis of the land use structure in the Yunnan Province during the period of 2008-2020 under three scenarios, the baseline scenario, low TFP (total factor productivity) scenario, and high TFP scenario. The results indicated that under all three scenarios, area of cultivated land declined significantly along with a remarkable expansion of built-up area, while areas of forest, grassland, and unused land increased slightly. The growth rate of TFP had first negative and then positive effects on the expansion of built-up area and decline of cultivated land as it increased. Moreover, the simulated changes of both cultivated land and built-up area were the biggest under the low TFP scenario, and far exceeded the limit in the Overall Plan for Land Utilization in the Yunnan Province in 2020. The scenario-based simulation results are of important reference value for policy-makers in making land use decisions, balancing the fierce competition between the protection of cultivated land and the increasing demand for built-up area, and guaranteeing food security, ecological security, and the sustainable development of land resources.

Time series evaluation of landscape dynamics using annual Landsat imagery and spatial statistical modeling: Evidence from the Phoenix metropolitan region

NASA Astrophysics Data System (ADS)

Fan, Chao; Myint, Soe W.; Rey, Sergio J.; Li, Wenwen

2017-06-01

Urbanization is a natural and social process involving simultaneous changes to the Earth's land systems, energy flow, demographics, and the economy. Understanding the spatiotemporal pattern of urbanization is increasingly important for policy formulation, decision making, and natural resource management. A combination of satellite remote sensing and patch-based models has been widely adopted to characterize landscape changes at various spatial and temporal scales. Nevertheless, the validity of this type of framework in identifying long-term changes, especially subtle or gradual land modifications is seriously challenged. In this paper, we integrate annual image time series, continuous spatial indices, and non-parametric trend analysis into a spatiotemporal study of landscape dynamics over the Phoenix metropolitan area from 1991 to 2010. We harness local indicators of spatial dependence and modified Mann-Kendall test to describe the monotonic trends in the quantity and spatial arrangement of two important land use land cover types: vegetation and built-up areas. Results suggest that declines in vegetation and increases in built-up areas are the two prevalent types of changes across the region. Vegetation increases mostly occur at the outskirts where new residential areas are developed from natural desert. A sizable proportion of vegetation declines and built-up increases are seen in the central and southeast part. Extensive land conversion from agricultural fields into urban land use is one important driver of vegetation declines. The xeriscaping practice also contributes to part of vegetation loss and an increasingly heterogeneous landscape. The quantitative framework proposed in this study provides a pathway to effective landscape mapping and change monitoring from a spatial statistical perspective.

The Influence of Urban Planning Affected Static and Stable Meteorological Field on Air Pollution

NASA Astrophysics Data System (ADS)

Zhang, Yue; Zhang, Liyuan; Zhang, Yunwei

2018-02-01

Accompany with the rapid urbanized and industrialized process, the built-up area and the number of high-rise buildings increased fast. Urban air quality is facing with the challenge caused by the rapid increase in energy consumption, motor vehicles owned, and the city construction. Long term high precision analysis on Beijing-Tianjin-Hebei region has been conducted in this article, so as to explore the influence of rapid increase in urban size and tall building amount on occurrence frequency of urban static and stable meteorological conditions as well as the contribution to urban PM2.5 pollution.

Development of Time-Series Human Settlement Mapping System Using Historical Landsat Archive

NASA Astrophysics Data System (ADS)

Miyazaki, H.; Nagai, M.; Shibasaki, R.

2016-06-01

Methodology of automated human settlement mapping is highly needed for utilization of historical satellite data archives for urgent issues of urban growth in global scale, such as disaster risk management, public health, food security, and urban management. As development of global data with spatial resolution of 10-100 m was achieved by some initiatives using ASTER, Landsat, and TerraSAR-X, next goal has targeted to development of time-series data which can contribute to studies urban development with background context of socioeconomy, disaster risk management, public health, transport and other development issues. We developed an automated algorithm to detect human settlement by classification of built-up and non-built-up in time-series Landsat images. A machine learning algorithm, Local and Global Consistency (LLGC), was applied with improvements for remote sensing data. The algorithm enables to use MCD12Q1, a MODIS-based global land cover map with 500-m resolution, as training data so that any manual process is not required for preparation of training data. In addition, we designed the method to composite multiple results of LLGC into a single output to reduce uncertainty. The LLGC results has a confidence value ranging 0.0 to 1.0 representing probability of built-up and non-built-up. The median value of the confidence for a certain period around a target time was expected to be a robust output of confidence to identify built-up or non-built-up areas against uncertainties in satellite data quality, such as cloud and haze contamination. Four scenes of Landsat data for each target years, 1990, 2000, 2005, and 2010, were chosen among the Landsat archive data with cloud contamination less than 20%.We developed a system with the algorithms on the Data Integration and Analysis System (DIAS) in the University of Tokyo and processed 5200 scenes of Landsat data for cities with more than one million people worldwide.

Modelled spatiotemporal variability of outdoor thermal comfort in local climate zones of the city of Brno, Czech Republic.

PubMed

Geletič, Jan; Lehnert, Michal; Savić, Stevan; Milošević, Dragan

2018-05-15

This study uses the MUKLIMO_3 urban climate model (in German, Mikroskaliges Urbanes KLImaMOdell in 3-Dimensionen) and measurements from an urban climate network in order to simulate, validate and analyse the spatiotemporal pattern of human thermal comfort outdoors in the city of Brno (Czech Republic) during a heat-wave period. HUMIDEX, a heat index designed to quantify human heat exposure, was employed to assess thermal comfort, employing air temperature and relative humidity data. The city was divided into local climate zones (LCZs) in order to access differences in intra-urban thermal comfort. Validation of the model results, based on the measurement dates within the urban monitoring network, confirmed that the MUKLIMO_3 micro-scale model had the capacity to simulate the main spatiotemporal patterns of thermal comfort in an urban area and its vicinity. The results suggested that statistically significant differences in outdoor thermal comfort exist in the majority of cases between different LCZs. The most built-up LCZ types (LCZs 2, 3, 5, 8 and 10) were disclosed as the most uncomfortable areas of the city. Hence, conditions of great discomfort (HUMIDEX >40) were recorded in these areas, mainly in the afternoon hours (from 13.00 to 18.00 CEST), while some thermal discomfort continued overnight. In contrast, HUMIDEX values in sparsely built-up LCZ 9 and non-urban LCZs were substantially lower and indicated better thermal conditions for the urban population. Interestingly, the model captured a local increase of HUMIDEX values arising out of air humidity in LCZs with the presence of more vegetation (LCZs A and B) and in the vicinity of larger bodies of water (LCZ G). Copyright © 2017 Elsevier B.V. All rights reserved.

Urbanization Reduces Transfer of Diverse Environmental Microbiota Indoors

PubMed Central

Parajuli, Anirudra; Grönroos, Mira; Siter, Nathan; Puhakka, Riikka; Vari, Heli K.; Roslund, Marja I.; Jumpponen, Ari; Nurminen, Noora; Laitinen, Olli H.; Hyöty, Heikki; Rajaniemi, Juho; Sinkkonen, Aki

2018-01-01

Expanding urbanization is a major factor behind rapidly declining biodiversity. It has been proposed that in urbanized societies, the rarity of contact with diverse environmental microbiota negatively impacts immune function and ultimately increases the risk for allergies and other immune-mediated disorders. Surprisingly, the basic assumption that urbanization reduces exposure to environmental microbiota and its transfer indoors has rarely been examined. We investigated if the land use type around Finnish homes affects the diversity, richness, and abundance of bacterial communities indoors. Debris deposited on standardized doormats was collected in 30 rural and 26 urban households in and near the city of Lahti, Finland, in August 2015. Debris was weighed, bacterial community composition determined by high throughput sequencing of bacterial 16S ribosomal RNA (rRNA) gene on the Illumina MiSeq platform, and the percentage of four different land use types (i.e., built area, forest, transitional, and open area) within 200 m and 2000 m radiuses from each household was characterized. The quantity of doormat debris was inversely correlated with coverage of built area. The diversity of total bacterial, Proteobacterial, Actinobacterial, Bacteroidetes, and Firmicutes communities decreased as the percentage of built area increased. Their richness followed the same pattern except for Firmicutes for which no association was observed. The relative abundance of Proteobacteria and particularly Gammaproteobacteria increased, whereas that of Actinobacteria decreased with increasing built area. Neither Phylum Firmicutes nor Bacteroidetes varied with coverage of built area. Additionally, the relative abundance of potentially pathogenic bacterial families and genera increased as the percentage of built area increased. Interestingly, having domestic animals (including pets) only altered the association between the richness of Gammaproteobacteria and diversity of Firmicutes with the built area coverage suggesting that animal ownership minimally affects transfer of environmental microbiota indoors from the living environment. These results support the hypothesis that people living in densely built areas are less exposed to diverse environmental microbiota than people living in more sparsely built areas. PMID:29467728

Multitemporal analysis of Landsat images to detect land use land cover changes for monitoring soil sealing in the Nola area (Naples, Italy)

NASA Astrophysics Data System (ADS)

De Giglio, Michaela; Allocca, Maria; Franci, Francesca

2016-10-01

Land Use Land Cover Changes (LULCC) data provide objective information to support environmental policy, urban planning purposes and sustainable land development. Understanding of past land use/cover practices and current landscape patterns is critical to assess the effects of LULCC on the Earth system. Within the framework of soil sealing in Italy, the present study aims to assess the LULCC of the Nola area (Naples metropolitan area, Italy), relating to a thirty year period from 1984 to 2015. The urban sprawl affects this area causing the impervious surface increase, the loss in rural areas and landscape fragmentation. Located near Vesuvio volcano and crossed by artificial filled rivers, the study area is subject to landslide, hydraulic and volcanic risks. Landsat time series has been processed by means of the supervised per-pixel classification in order to produce multitemporal Land Use Land Cover maps. Then, post-classification comparison approach has been applied to quantify the changes occurring between 1984 and 2015, also analyzing the intermediate variations in 1999, namely every fifteen years. The results confirm the urban sprawl. The increase of the built-up areas mainly causes the habitat fragmentation and the agricultural land conversion of the Nola area that is already damaged by unauthorized disposal of urban waste. Moreover, considering the local risk maps, it was verified that some of the new urban areas were built over known hazardous sites. In order to limit the soil sealing, urgent measures and sustainable urban planning are required.

Application of Machine Learning in Urban Greenery Land Cover Extraction

NASA Astrophysics Data System (ADS)

Qiao, X.; Li, L. L.; Li, D.; Gan, Y. L.; Hou, A. Y.

2018-04-01

Urban greenery is a critical part of the modern city and the greenery coverage information is essential for land resource management, environmental monitoring and urban planning. It is a challenging work to extract the urban greenery information from remote sensing image as the trees and grassland are mixed with city built-ups. In this paper, we propose a new automatic pixel-based greenery extraction method using multispectral remote sensing images. The method includes three main steps. First, a small part of the images is manually interpreted to provide prior knowledge. Secondly, a five-layer neural network is trained and optimised with the manual extraction results, which are divided to serve as training samples, verification samples and testing samples. Lastly, the well-trained neural network will be applied to the unlabelled data to perform the greenery extraction. The GF-2 and GJ-1 high resolution multispectral remote sensing images were used to extract greenery coverage information in the built-up areas of city X. It shows a favourable performance in the 619 square kilometers areas. Also, when comparing with the traditional NDVI method, the proposed method gives a more accurate delineation of the greenery region. Due to the advantage of low computational load and high accuracy, it has a great potential for large area greenery auto extraction, which saves a lot of manpower and resources.

Analysis of Urban Expansion of the Resort City of Al Ain Using Remote Sensing and GIS

NASA Astrophysics Data System (ADS)

Issa, S.; Al Shuwaihi, A.

2009-12-01

The urban growth of AL Ain city has been investigated using remote sensing data for three different dates, 1972, 1990 and 2000. We used three Landsat images together with socio-economic data in a post-classification analysis to map the spatial dynamics of land use/cover changes and identify the urbanization process in Al Ain resort city, United Arab Emirates. Land use/cover statistics, extracted from Landsat Multi-spectral Scanner (MSS). Thematic Mapper (TM) and Enhanced Thematic Mapper plus (ETM +) images for 1972. 1990 and 2000 respectively, revealed that the built-up area has expanded by about 170.53km2. The city was found to have a tendency for major expansion in four different directions: along the Abu Dhabi highway, along Dubai highway, Myziad direction and Hafeet recreational area. Expansion in any direction was found to be governed by the availability of road network, suitability for construction, utilities, economic activities, geographical constraints, and legal factors (boundary with Sultanate of Oman). The road network in particular has influenced the spatial patterns and structure of urban development, so that the expansion of the built-up areas has assumed an accretive as well as linear growth along the major roads. The research concludes that the development is based on conservation of agricultural areas (oases) and reclamation of the desert for farming and agricultural activities. The integration of remote sensing and GIS was found to be effective in monitoring LULC changes and providing valuable information necessary for planning and research.

Determining the impact of urban components on land surface temperature of Istanbul by using remote sensing indices.

PubMed

Bektaş Balçik, Filiz

2014-02-01

For the past 60 years, Istanbul has been experiencing an accelerated urban expansion. This urban expansion is leading to the replacement of natural surfaces by various artificial materials. This situation has a critical impact on the environment due to the alteration of heat energy balance. In this study, the effect upon the urban heat island (UHI) of Istanbul was analyzed using 2009 dated Landsat 5 Thematic Mapper (TM) data. An Index Based Built-up Index (IBI) was used to derive artificial surfaces in the study area. To produce the IBI index, Soil-Adjusted Vegetation Index, Normalized Difference Built-up Index, and Modified Normalized Difference Water Index were calculated. Land surface temperature (LST) distribution was derived from Landsat 5 TM images using a mono-window algorithm. In addition, 24 transects were selected, and different regression models were applied to explore the correlation between LST and IBI index. The results show that artificial surfaces have a positive exponential relationship with LST rather than a simple linear one. An ecological evaluation index of the region was calculated to explore the impact of both the vegetated land and the artificial surfaces on the UHI. Therefore, the quantitative relationship of urban components (artificial surfaces, vegetation, and water) and LST was examined using multivariate statistical analysis, and the correlation coefficient was obtained as 0.829. This suggested that the areas with a high rate of urbanization will accelerate the rise of LST and UHI in Istanbul.

Urbanization on the US landscape: looking ahead in the 21st century.

Treesearch

Ralph J. Alig; Jeffrey D. Kline; Mark Lichtenstein

2004-01-01

Conversion of rural lands to urban and other built-up uses affects the mix of commodities and services produced from the global land base. In the United States, there was a 34% increase in the amount of land devoted to urban and built-up uses between 1982 and 1997. This increase came predominantly from the conversion of croplands and forestland, with the largest...

Remote sensing study of the impact of vegetation on thermal environment in different contexts

NASA Astrophysics Data System (ADS)

Xie, Qijiao; Wu, Yingjiao; Zhou, Zhixiang; Wang, Zhengxiang

2018-02-01

Satellite remote sensing technology provides informative data for detecting the land surface temperature (LST) distribution and urban heat island (UHI) effect remotely and regionally. In this study, two Landsat Thematic Mapper (TM) images acquired on September 26, 1987 and September 17, 2013 were used to derive LST and the normalized difference vegetation index (NDVI) values in Wuhan, China. The relationships between NDVI and LST were examined in different contexts, namely built-up area, farmland, grassland and forest. Results showed that negative correlations between the mean NDVI and LST were detected in all observed land covers, which meant that vegetation was efficient in decreasing surface temperatures and mitigating UHI effect. The cooling efficiency of vegetation on thermal environment varied with different contexts. As mean NDVI increased at each 0.1, the decreased LST values in built-up area, farmland, grassland and forest were 1.4 °C, 1.4 °C, 1.1 °C, 1.9 °C in 1987 and 1.4 °C, 1.7 °C, 1.3 °C, 1.8 °C in 2013, respectively. This finding encourages urban planners and greening designers to devote more efforts in protecting urban forests.

7 CFR 1455.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... documents issued in accordance with this part, except as otherwise provided in this section. (b) The... equivalent stocking) by live trees of any size, including land that formerly had such tree cover and that... trees and forest areas adjacent to urban and built-up lands. Roadside, streamside, and shelterbelt...

7 CFR 1455.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... documents issued in accordance with this part, except as otherwise provided in this section. (b) The... equivalent stocking) by live trees of any size, including land that formerly had such tree cover and that... trees and forest areas adjacent to urban and built-up lands. Roadside, streamside, and shelterbelt...

7 CFR 1455.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... documents issued in accordance with this part, except as otherwise provided in this section. (b) The... equivalent stocking) by live trees of any size, including land that formerly had such tree cover and that... trees and forest areas adjacent to urban and built-up lands. Roadside, streamside, and shelterbelt...

7 CFR 1455.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... documents issued in accordance with this part, except as otherwise provided in this section. (b) The... equivalent stocking) by live trees of any size, including land that formerly had such tree cover and that... trees and forest areas adjacent to urban and built-up lands. Roadside, streamside, and shelterbelt...

An Evaluation of Population Density Mapping and Built up Area Estimates in Sri Lanka Using Multiple Methodologies

NASA Astrophysics Data System (ADS)

Engstrom, R.; Soundararajan, V.; Newhouse, D.

2017-12-01

In this study we examine how well multiple population density and built up estimates that utilize satellite data compare in Sri Lanka. The population relationship is examined at the Gram Niladhari (GN) level, the lowest administrative unit in Sri Lanka from the 2011 census. For this study we have two spatial domains, the whole country and a 3,500km2 sub-sample, for which we have complete high spatial resolution imagery coverage. For both the entire country and the sub-sample we examine how consistent are the existing publicly available measures of population constructed from satellite imagery at predicting population density? For just the sub-sample we examine how well do a suite of values derived from high spatial resolution satellite imagery predict population density and how does our built up area estimate compare to other publicly available estimates. Population measures were obtained from the Sri Lankan census, and were downloaded from Facebook, WorldPoP, GPW, and Landscan. Percentage built-up area at the GN level was calculated from three sources: Facebook, Global Urban Footprint (GUF), and the Global Human Settlement Layer (GHSL). For the sub-sample we have derived a variety of indicators from the high spatial resolution imagery. Using deep learning convolutional neural networks, an object oriented, and a non-overlapping block, spatial feature approach. Variables calculated include: cars, shadows (a proxy for building height), built up area, and buildings, roof types, roads, type of agriculture, NDVI, Pantex, and Histogram of Oriented Gradients (HOG) and others. Results indicate that population estimates are accurate at the higher, DS Division level but not necessarily at the GN level. Estimates from Facebook correlated well with census population (GN correlation of 0.91) but measures from GPW and WorldPop are more weakly correlated (0.64 and 0.34). Estimates of built-up area appear to be reliable. In the 32 DSD-subsample, Facebook's built- up area measure is highly correlated with our built-up measure (correlation of 0.9). Preliminary regression results based on variables selected from Lasso-regressions indicate that satellite indicators have exceptionally strong predictive power in predicting GN level population level and density with an out of sample r-squared of 0.75 and 0.72 respectively.

The influence of land urbanization on landslides: An empirical estimation based on Chinese provincial panel data.

PubMed

Li, Gerui; Lei, Yalin; Yao, Huajun; Wu, Sanmang; Ge, Jianping

2017-10-01

This study used panel data for 28 provinces and municipalities in China from 2003 to 2014 to investigate the relationship between land urbanization and landslides by building panel models for a national sample and subsamples from the three regions of China and studied the problems of landslide prevention measures based on the relationship. The results showed that 1) at the national level, the percentage of built-up area and road density are respectively negative and positive for landslides. 2) At the regional level, the improvement of landslide prevention measures with increasing economic development only appears in built-up areas. The percentage of built-up areas increases the number of landslides in the western region and decreases the number in the central and eastern regions; the degree of decrease in the eastern region is larger than in the central region. Road density increases the number of landslides in each region, and the degree increases gradually from the west to the east. 3) The effect of landslide prevention funding is not obvious. Although the amount of landslide prevention funds decreases the number of landslides at the national level, the degree of increase is too small. Except in the central region, the amount of landslide prevention funding did not decrease the number of landslides effectively in the western and eastern regions. We propose a series of policy implications based on these test results that may help to improve landslide prevention measures. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling reduction of the Urban Heat Island effect to counter-act the effects of climate change in densely built-up areas

NASA Astrophysics Data System (ADS)

Andre, Konrad; Zuvela-Aloise, Maja; Lettmayer, Gudrun; Schwaiger, Hannes Peter; Kaltenegger, Ingrid; Bird, David Neil; Woess-Gallasch, Susanne

2017-04-01

The phenomenon of Urban Heat Islands (UHIs) observed in cities, caused by changes in energy balance due to the structural development of the city as well as by sealed surfaces and a lack of vegetation, is expected to strengthen in the future and will further contribute to heat stress, creating an increased need for energy for cooling and ventilation as well as lowering human comfort. Due to a changing climate, rising heat stress, pronounced by an increased intensity or frequency of heat waves, could have far reaching implications for major Austrian cities in the near future. Simultaneous to this expected increasing of the already existing UHI-effect, it is observable, that continuous densification of the core parts of cities is being intensified through implemented traditional urban planning measures. This is particular relevant for high densely populated districts of the city. Several possible counteractions how to address this challenge are already known, partly investigated in urban modeling studies on the effects of modifying the reflective properties of buildings and urban areas for the city of Vienna. On this experience, within the Austrian FFG and KLIEN Smart Cities project JACKY COOL CHECK (Project Nr. 855554), a wide set of measures to reduce heat stress, consisting of e.g. unsealed surfaces, green areas, green roofs, improve reflective properties of different surfaces etc., for the densely built-up residential and business district of Jakomini in the city of Graz/Styria is investigated, to gain decisive data pointing out the peculiarities of UHIs and the potential cooling effects of these target measures for this local specific area. These results serving as a basis for the selection of sustainable measures that will be implemented, in coordination with local stakeholders and considering their interests.

Spatiotemporal Analysis of Urban Land Cover Changes in Kigali, Rwanda Using Multitemporal Landsat Data and Landscape Metrics

NASA Astrophysics Data System (ADS)

Mugiraneza, T.; Haas, J.; Ban, Y.

2017-11-01

Mapping urbanization and ensuing environmental impacts using satellite data combined with landscape metrics has become a hot research topic. The objectives of the study are to analyze the spatio-temporal evolution of urbanization patterns of Kigali, Rwanda over the last three decades (from 1984 to 2015) using multitemporal Landsat data and to assess the associated environmental impact using landscape metrics. Landsat images, Normalized Difference Vegetation Index (NDVI), Grey Level Co-occurrence Matrix (GLCM) variance texture and digital elevation model (DEM) data were classified using a support vector machine (SVM). Eight landscape indices were derived from classified images for urbanization environment impact assessment. Seven land cover classes were derived with an overall accuracy exceeding 88 % with Kappa Coefficients around 0.8. As most prominent changes, cropland was reduced considerably in favour of built-up areas that increased from 2,349 ha to 11,579 ha between 1984 and 2015. During those 31 years, the increased number of patches in most land cover classes illustrated landscape fragmentation, especially for forest. The landscape configuration indices demonstrate that in general the land cover pattern remained stable for cropland but it was highly changed in built-up areas. Satellite-based analysis and quantification of urbanization and its effects using landscape metrics are found to be interesting for grassroots and provide a cost-effective method for urban information production. This information can be used for e.g. potential design and implementation of early warning systems that cater for urbanization effects.

Coupling of Markov chains and cellular automata spatial models to predict land cover changes (case study: upper Ci Leungsi catchment area)

NASA Astrophysics Data System (ADS)

Marko, K.; Zulkarnain, F.; Kusratmoko, E.

2016-11-01

Land cover changes particular in urban catchment area has been rapidly occur. Land cover changes occur as a result of increasing demand for built-up area. Various kinds of environmental and hydrological problems e.g. floods and urban heat island can happen if the changes are uncontrolled. This study aims to predict land cover changes using coupling of Markov chains and cellular automata. One of the most rapid land cover changes is occurs at upper Ci Leungsi catchment area that located near Bekasi City and Jakarta Metropolitan Area. Markov chains has a good ability to predict the probability of change statistically while cellular automata believed as a powerful method in reading the spatial patterns of change. Temporal land cover data was obtained by remote sensing satellite imageries. In addition, this study also used multi-criteria analysis to determine which driving factor that could stimulate the changes such as proximity, elevation, and slope. Coupling of these two methods could give better prediction model rather than just using it separately. The prediction model was validated using existing 2015 land cover data and shown a satisfactory kappa coefficient. The most significant increasing land cover is built-up area from 24% to 53%.

Alternative Locations for School Buildings.

ERIC Educational Resources Information Center

Earthman, Glen I.

1999-01-01

School systems in urbanized or built-up areas have difficulties locating suitable sites for new buildings. Examples of the use of space in alternative locations include the Parkway Program in Philadelphia; the Work Place School in Alberta, Canada; the Metropolitan Learning Alliance in Minnesota; and the Schoolhouse Boat in Vienna, Austria. (MLF)

Control Scheme of River-lake System from the View of Ecological Sponge Basin aiming at Sponge City Construction

NASA Astrophysics Data System (ADS)

Ding, X.; Liu, J.; Yang, Z.

2017-12-01

China is in the rapid advance of urbanization, and is promoting the Sponge City Construction (SCC) with the characteristics of natural accumulation, natural infiltration and natural purification. The Chinese government selected 16 and 14 cities as pilot cities in 2015 and 2016 respectively to carry out SCC taking Low Impact Development (LID) as the concept. However, in 2015 and 2016, water-logging occurred in 10 cities and 9 cities respectively during the pilot cities. Therefore, relying solely on LID can not solve the problem of urban flood and waterlogging. Except for a series of LID measures during the process of SCC, corresponding control scheme of river-lake system should be established to realize water-related targets. From the view of ecological sponge basin, this study presents the general idea of SCC both in and out of the unban built-up area and the corresponding control scheme of river-lake system: for the regions outside the built-up area, the main aim of SCC is to carry out the top-level design of urban flood control and waterlogging, establish the water security system outside the city for solving the problems including flood control, water resources, water environment and water ecology; for the built-up area, the main aim of SCC is to construct different kinds of urban sponge according to local conditions and develop multi-scale drainage system responding to different intensities of rainfall taking the river-lake system as the core. Taking Fenghuang County of Hunan Province as an example for the application research, the results indicate that, after the implementation of the control scheme of river-lake system: 1) together with other SCC measures including LID, the control rate of total annual runoff in Fenghuang County is expected to be 82.9% which meets the target requirement of 80%; 2) flood control and drainage standards in Fenghuang County can be increased from the current 10-year return to 20-year return; 3) urban and rural water supply guarantee rate is expected to be 98% which meets the target requirement of 95%. Therefore, the control scheme of urban river-lake system in the county is technically feasible, and can effectively solve the problems including flood control, water resources shortage and ecological water demand in the county, thus may provide strong support and guarantee for SCC.

A Pattern-Based Definition of Urban Context Using Remote Sensing and GIS

PubMed Central

Benza, Magdalena; Weeks, John R.; Stow, Douglas A.; López-Carr, David; Clarke, Keith C.

2016-01-01

In Sub-Saharan Africa rapid urban growth combined with rising poverty is creating diverse urban environments, the nature of which are not adequately captured by a simple urban-rural dichotomy. This paper proposes an alternative classification scheme for urban mapping based on a gradient approach for the southern portion of the West African country of Ghana. Landsat Enhanced Thematic Mapper Plus (ETM+) and European Remote Sensing Satellite-2 (ERS-2) synthetic aperture radar (SAR) imagery are used to generate a pattern based definition of the urban context. Spectral mixture analysis (SMA) is used to classify a Landsat scene into Built, Vegetation and Other land covers. Landscape metrics are estimated for Built and Vegetation land covers for a 450 meter uniform grid covering the study area. A measure of texture is extracted from the SAR imagery and classified as Built/Non-built. SMA based measures of Built and Vegetation fragmentation are combined with SAR texture based Built/Non-built maps through a decision tree classifier to generate a nine class urban context map capturing the transition from unsettled land at one end of the gradient to the compact urban core at the other end. Training and testing of the decision tree classifier was done using very high spatial resolution reference imagery from Google Earth. An overall classification agreement of 77% was determined for the nine-class urban context map, with user’s accuracy (commission errors) being lower than producer’s accuracy (omission errors). Nine urban contexts were classified and then compared with data from the 2000 Census of Ghana. Results suggest that the urban classes appropriately differentiate areas along the urban gradient. PMID:27867227

A Pattern-Based Definition of Urban Context Using Remote Sensing and GIS.

PubMed

Benza, Magdalena; Weeks, John R; Stow, Douglas A; López-Carr, David; Clarke, Keith C

2016-09-15

In Sub-Saharan Africa rapid urban growth combined with rising poverty is creating diverse urban environments, the nature of which are not adequately captured by a simple urban-rural dichotomy. This paper proposes an alternative classification scheme for urban mapping based on a gradient approach for the southern portion of the West African country of Ghana. Landsat Enhanced Thematic Mapper Plus (ETM+) and European Remote Sensing Satellite-2 (ERS-2) synthetic aperture radar (SAR) imagery are used to generate a pattern based definition of the urban context. Spectral mixture analysis (SMA) is used to classify a Landsat scene into Built, Vegetation and Other land covers. Landscape metrics are estimated for Built and Vegetation land covers for a 450 meter uniform grid covering the study area. A measure of texture is extracted from the SAR imagery and classified as Built/Non-built. SMA based measures of Built and Vegetation fragmentation are combined with SAR texture based Built/Non-built maps through a decision tree classifier to generate a nine class urban context map capturing the transition from unsettled land at one end of the gradient to the compact urban core at the other end. Training and testing of the decision tree classifier was done using very high spatial resolution reference imagery from Google Earth. An overall classification agreement of 77% was determined for the nine-class urban context map, with user's accuracy (commission errors) being lower than producer's accuracy (omission errors). Nine urban contexts were classified and then compared with data from the 2000 Census of Ghana. Results suggest that the urban classes appropriately differentiate areas along the urban gradient.

Impacts of urban sprawl on the area of downtown lakes in a highly developing city on central China

NASA Astrophysics Data System (ADS)

Zhang, W.; Zhang, Y.

2016-12-01

Wuhan city in central China is full of water resources and numerous lakes are located. Downtown lakes have significant ecological value and ornamental value for urban inhabitants in Wuhan. Under the rapid process of urban sprawl, downtown lakes are occupied by impervious areas. This research uses Landsat images to extract land uses from 1991 to 2013 in Wuhan city , and attempts to find out how urban sprawl affects the water body area decline in space. Two largest downtown lakes in Wuhan city, Donghu Lake located in central city and Tangxunhu Lake located in suburbs, are taken as case study area. A direction change index (DCI) is proposed to evaluate the changes of a specific land use in different directions. The results reveal that two downtown lakes are undergoing rapid water body area decline from 1991 to 2013, with decline rate are -0.022 in Donghu watershed and -0.011 in Tangxunhu watershed. 68.26% and 62.50% of the reduced water body is occupied by built-up land in Donghu watershed and Tangxunhu watershed, respectively. According to DCI, the water body reduce is highly correlated with built-up land increase in all direction. Moreover, it is found that in the Donghu watershed the north-west part suffered significant water body area decline, which is close to central city. While in Tangxunhu watershed, the area of water body declined in north-west, south-west and north-east part, and the area obstructed from central city by the lake was suffering less water body area decline. It is concluded that the water body area of downtown lakes are highly affected by the process of urban sprawl, and the lakes in central districts trends to suffer higher descend than that of the downtown lake located in suburbs. Meanwhile, even for the same downtown lake, the area orientating and close to the central city may suffer more rapid decline than the area that does not orientate to the central city.

Examining Urban Expansion Using Multi-Temporal Landsat Imagery: a Case Study of the Montreal Census Metropolitan Area from 1975 TO 2015, Canada

NASA Astrophysics Data System (ADS)

Ma, Lingfei; Zhao, He; Li, Jonathan

2016-06-01

Urban expansion, particularly the movement of residential and commercial land use to sub-urban areas in metropolitan areas, has been considered as a significant signal of regional economic development. In 1970s, the economic centre of Canada moved from Montreal to Toronto. Since some previous research have been focused on the urbanization process in Greater Toronto Area (GTA), it is significant to conduct research in its counterpart. This study evaluates urban expansion process in Montréal census metropolitan area (CMA), Canada, between 1975 and 2015 using satellite images and socio-economic data. Spatial and temporal dynamic information of urbanization process was quantified using Landsat imagery, supervised classification algorithms and the post-classification change detection technique. Accuracy of the Landsat-derived land use classification map ranged from 80% to 97%. The results indicated that continuous growth of built-up areas in the CMA over the study period resulted in a decrease in the area of cultivated land and vegetation. The results showed that urban areas expanded 442 km2 both along major river systems and lakeshores, as well as expanded from urban centres to surrounded areas. The analysis revealed that urban expansion has been largely driven by population growth and economic development. Consequently, the urban expansion maps produced in this research can assist decision-makers to promote sustainable urban development, and forecast potential changes in urbanization growth patterns.

Urban Modelling Performance of Next Generation SAR Missions

NASA Astrophysics Data System (ADS)

Sefercik, U. G.; Yastikli, N.; Atalay, C.

2017-09-01

In synthetic aperture radar (SAR) technology, urban mapping and modelling have become possible with revolutionary missions TerraSAR-X (TSX) and Cosmo-SkyMed (CSK) since 2007. These satellites offer 1m spatial resolution in high-resolution spotlight imaging mode and capable for high quality digital surface model (DSM) acquisition for urban areas utilizing interferometric SAR (InSAR) technology. With the advantage of independent generation from seasonal weather conditions, TSX and CSK DSMs are much in demand by scientific users. The performance of SAR DSMs is influenced by the distortions such as layover, foreshortening, shadow and double-bounce depend up on imaging geometry. In this study, the potential of DSMs derived from convenient 1m high-resolution spotlight (HS) InSAR pairs of CSK and TSX is validated by model-to-model absolute and relative accuracy estimations in an urban area. For the verification, an airborne laser scanning (ALS) DSM of the study area was used as the reference model. Results demonstrated that TSX and CSK urban DSMs are compatible in open, built-up and forest land forms with the absolute accuracy of 8-10 m. The relative accuracies based on the coherence of neighbouring pixels are superior to absolute accuracies both for CSK and TSX.

Development and Applications of a Comprehensive Land Use Classification and Map for the US

PubMed Central

Theobald, David M.

2014-01-01

Land cover maps reasonably depict areas that are strongly converted by human activities, but typically are unable to resolve low-density but widespread development patterns. Data products specifically designed to resolve land uses complement land cover datasets and likely improve our ability to understand the extent and complexity of human modification. Methods for developing a comprehensive land use classification system are described, and a map of land use for the conterminous United States is presented to reveal what we are doing on the land. The comprehensive, detailed and high-resolution dataset was developed through spatial analysis of nearly two-dozen publicly-available, national spatial datasets – predominately based on census housing, employment, and infrastructure, as well as land cover from satellite imagery. This effort resulted in 79 land use classes that fit within five main land use groups: built-up, production, recreation, conservation, and water. Key findings from this study are that built-up areas occupy 13.6% of mainland US, but that the majority of this occurs as low-density exurban/rural residential (9.1% of the US), while more intensive built-up land uses occupy 4.5%. For every acre of urban and suburban residential land, there are 0.13 commercial, 0.07 industrial, 0.48 institutional, and 0.29 acres of interstates/highways. This database can be used to address a variety of natural resource applications, and I provide three examples here: an entropy index of the diversity of land uses for smart-growth planning, a power-law scaling of metropolitan area population to developed footprint, and identifying potential conflict areas by delineating the urban interface. PMID:24728210

Built-up Land Expansion in Urban China

NASA Astrophysics Data System (ADS)

Chen, Yi; Chen, Zhigang; Huang, Xianjin

2017-04-01

Since the implementation of the reform and opening-up, rapid expansion of built-up land has caused a rapid reduction of arable land. The Ministry of Land and Resources of the People' s Republic of China has strengthened the management of built-up land through the basic arable land protection and the quota allocation of built-up land to control the urban sprawl. In addition, the general land use planning and the annual land use plan have been used to further ensure the effectiveness of land use management and control. However, the trend of built-up land expansion has not been effectively restrained. The built-up land expansion increased from 31.92 × 106 hm2 in 2005 to 38.89 × 106 hm2 in 2012. The rapid expansion of built-up land has been the major feature of land use changes in China and has led to built-up land vacancy and inefficient land use. This paper used a Data Envelopment Analysis (DEA) model to analyze the changes in built-up land efficiency in 336 cities in China from 2005 to 2012 during the implementation of National General Land Use Plan (2006-2020) (NGLUP). The results showed that the built-up land input-output efficiency of most cities declined, and more than half of the cities had excessive inputs of built-up land. Even in the most developed region of China, the built-up land efficiency was relatively low. The paper argues that the NGLUP failed to control the expansion of built-up land and to promote intensive land use. The allocation of built-up land designated by the Plan was not reasonable, and economic development has greatly relied on land inputs, which need to be improved. The paper finally suggests that the built-up land indices should be appropriately directed toward economically underdeveloped regions in central and western China, and the establishment of a withdrawal mechanism for inefficient land would better promote the efficient allocation of built-up land.

Monitoring Spatiotemporal Changes of Heat Island in Babol City due to Land Use Changes

NASA Astrophysics Data System (ADS)

Alavi Panah, S. K.; Kiavarz Mogaddam, M.; Karimi Firozjaei, M.

2017-09-01

Urban heat island is one of the most vital environmental risks in urban areas. The advent of remote sensing technology provides better visibility due to the integrated view, low-cost, fast and effective way to study and monitor environmental and humanistic changes. The aim of this study is a spatiotemporal evaluation of land use changes and the heat island in the time period of 1985-2015 for the studied area in the city of Babol. For this purpose, multi-temporal Landsat images were used in this study. For calculating the land surface temperature (LST), single-channel and maximum likelihood algorithms were used, to classify Images. Therefore, land use changes and LST were examined, and thereby the relationship between land-use changes was analyzed with the normalized LST. By using the average and standard deviation of normalized thermal images, the area was divided into five temperature categories, inter alia, very low, low, medium, high and very high and then, the heat island changes in the studied time period were investigated. The results indicate that land use changes for built-up lands increased by 92%, and a noticeable decrease was observed for agricultural lands. The Built-up land changes trend has direct relation with the trend of normalized surface temperature changes. Low and very low-temperature categories which follow a decreasing trend, are related to lands far away from the city. Also, high and very high-temperature categories whose areas increase annually, are adjacent to the city center and exit ways of the town. The results emphasize on the importance of attention of urban planners and managers to the urban heat island as an environmental risk.

[Vegetation change in Shenzhen City based on NDVI change classification].

PubMed

Li, Yi-Jing; Zeng, Hui; Wel, Jian-Bing

2008-05-01

Based on the TM images of 1988 and 2003 as well as the land-use change survey data in 2004, the vegetation change in Shenzhen City was assessed by a NDVI (normalized difference vegetation index) change classification method, and the impacts from natural and social constraining factors were analyzed. The results showed that as a whole, the rapid urbanization in 1988-2003 had less impact on the vegetation cover in the City, but in its plain areas with low altitude, the vegetation cover degraded more obviously. The main causes of the localized ecological degradation were the invasion of built-ups to woods and orchards, land transformation from woods to orchards at the altitude of above 100 m, and low percentage of green land in some built-ups areas. In the future, the protection and construction of vegetation in Shenzhen should focus on strengthening the protection and restoration of remnant woods, trying to avoid the built-ups' expansion to woods and orchards where are better vegetation-covered, rectifying the unreasonable orchard constructions at the altitude of above 100 m, and consolidating the greenbelt construction inside the built-ups. It was considered that the NDVI change classification method could work well in efficiently uncovering the trend of macroscale vegetation change, and avoiding the effect of random noise in data.

Quantifying landscape pattern and connectivity in a Mediterranean coastal settlement: the case of the Urla district, Turkey.

PubMed

Coskun Hepcan, Cigdem

2013-01-01

This study was aimed at analyzing and interpreting changes in landscape pattern and connectivity in the Urla district, Turkey using core landscape metrics based on a 42-year data derived from 1963 CORONA and 2005 ASTER satellite images and ten 1/25,000 topographical maps (1963-2005). The district represents a distinctive example of re-emerged suburbanization in the Izmir metropolitan area. In order to explore landscape characteristics of the study area, nine landscape composition and configuration metrics were chosen as follows: class area, percentage of landscape, number of patches, patch density, largest patch index, landscape shape index, mean patch size, perimeter area fractal dimension, and connectance index. The landscape configurations in the Urla district changed significantly by 2005 in that the process of (sub-)urbanization in the study area evolved from a rural, monocentric urban typology to a more suburban, polycentric morphology. Agricultural, maquis-phrygana, and forest areas decreased, while the built-up, olive plantation and phrygana areas increased. There was nearly a fivefold increase in the built-up areas during the study period, and the connectivity of the natural landscape declined. To prevent further fragmentation, it is important to keep the existing natural land cover types and agricultural areas intact. More importantly, a sustainable development scenario is required that contains a green infrastructure, or an ecological network planning for conservation and rehabilitation of the vital natural resources in the study area.

Modeling Surface Climate in US Cities Using Simple Biosphere Model Sib2

NASA Technical Reports Server (NTRS)

Zhang, Ping; Bounoua, Lahouari; Thome, Kurtis; Wolfe, Robert; Imhoff, Marc

2015-01-01

We combine Landsat- and the Moderate Resolution Imaging Spectroradiometer (MODIS)-based products in the Simple Biosphere model (SiB2) to assess the effects of urbanized land on the continental US (CONUS) surface climate. Using National Land Cover Database (NLCD) Impervious Surface Area (ISA), we define more than 300 urban settlements and their surrounding suburban and rural areas over the CONUS. The SiB2 modeled Gross Primary Production (GPP) over the CONUS of 7.10 PgC (1 PgC= 10(exp 15) grams of Carbon) is comparable to the MODIS improved GPP of 6.29 PgC. At state level, SiB2 GPP is highly correlated with MODIS GPP with a correlation coefficient of 0.94. An increasing horizontal GPP gradient is shown from the urban out to the rural area, with, on average, rural areas fixing 30% more GPP than urbans. Cities built in forested biomes have stronger UHI magnitude than those built in short vegetation with low biomass. Mediterranean climate cities have a stronger UHI in wet season than dry season. Our results also show that for urban areas built within forests, 39% of the precipitation is discharged as surface runoff during summer versus 23% in rural areas.

Land Use Dynamics of the Fast-Growing Shanghai Metropolis, China (1979–2008) and its Implications for Land Use and Urban Planning Policy

PubMed Central

Zhang, Hao; Zhou, Li-Guo; Chen, Ming-Nan; Ma, Wei-Chun

2011-01-01

Through the integrated approach of remote sensing and geographic information system (GIS) techniques, four Landsat TM/ETM+ imagery acquired during 1979 and 2008 were used to quantitatively characterize the patterns of land use and land cover change (LULC) and urban sprawl in the fast-growing Shanghai Metropolis, China. Results showed that, the urban/built-up area grew on average by 4,242.06 ha yr−1. Bare land grew by 1,594.66 ha yr−1 on average. In contrast, cropland decreased by 3,286.26 ha yr−1 on average, followed by forest and shrub, water, and tidal land, which decreased by 1,331.33 ha yr−1, 903.43 ha yr−1, and 315.72 ha yr−1 on average, respectively. As a result, during 1979 and 2008 approximately 83.83% of the newly urban/built-up land was converted from cropland (67.35%), forest and shrub (9.12%), water (4.80%), and tidal land (2.19%). Another significant change was the continuous increase in regular residents, which played a very important role in contributing to local population growth and increase in urban/built-up land. This can be explained with this city’s huge demand for investment and qualified labor since the latest industrial transformation. Moreover, with a decrease in cropland, the proportion of population engaged in farming decreased 13.84%. Therefore, significant socio-economic transformation occurred, and this would lead to new demand for land resources. However, due to very scarce land resources and overload of population in Shanghai, the drive to achieve economic goals at the loss of cropland, water, and the other lands is not sustainable. Future urban planning policy aiming at ensuring a win-win balance between sustainable land use and economic growth is urgently needed. PMID:22319382

Modelling urban growth in the Indo-Gangetic plain using nighttime OLS data and cellular automata

NASA Astrophysics Data System (ADS)

Roy Chowdhury, P. K.; Maithani, Sandeep

2014-12-01

The present study demonstrates the applicability of the Operational Linescan System (OLS) sensor in modelling urban growth at regional level. The nighttime OLS data provides an easy, inexpensive way to map urban areas at a regional scale, requiring a very small volume of data. A cellular automata (CA) model was developed for simulating urban growth in the Indo-Gangetic plain; using OLS data derived maps as input. In the proposed CA model, urban growth was expressed in terms of causative factors like economy, topography, accessibility and urban infrastructure. The model was calibrated and validated based on OLS data of year 2003 and 2008 respectively using spatial metrics measures and subsequently the urban growth was predicted for the year 2020. The model predicted high urban growth in North Western part of the study area, in south eastern part growth would be concentrated around two cities, Kolkata and Howrah. While in the middle portion of the study area, i.e., Jharkhand, Bihar and Eastern Uttar Pradesh, urban growth has been predicted in form of clusters, mostly around the present big cities. These results will not only provide an input to urban planning but can also be utilized in hydrological and ecological modelling which require an estimate of future built up areas especially at regional level.

Classification of residential areas according to physical vulnerability to natural hazards: a case study of Çanakkale, Turkey.

PubMed

Başaran-Uysal, Arzu; Sezen, Funda; Ozden, Süha; Karaca, Oznur

2014-01-01

The selection of new settlement areas and the construction of safe buildings, as well as rendering built-up areas safe, are of great importance in mitigating the damage caused by natural disasters. Most cities in Turkey are unprepared for natural hazards. In this paper, Çanakkale, located in a first-degree seismic zone and sprawled around the Sartçay Delta, is examined in terms of its physical vulnerability to natural hazards. Residential areas are analysed using GIS (geographic information system) and remote-sensing technologies in relation to selected indicators. Residential areas of the city are divided into zones according to an evaluation of geological characteristics, the built-up area's features, and urban infrastructure, and four risk zones are determined. The results of the analysis show that the areas of the city suitable for housing are very limited. In addition, the historical centre and the housing areas near Sartçay stream are shown to be most problematic in terms of natural disasters and sustainability. © 2014 The Author(s). Disasters © Overseas Development Institute, 2014.

Built Environment and Obesity by Urbanicity in the U.S

PubMed Central

Xu, Yanqing; Wang, Fahui

2015-01-01

Based on the data from the Behavioral Risk Factor Surveillance System 2012, this study examines the association of neighborhood built environments with individual physical inactivity and obesity in the U.S. Multilevel modeling is used to control for the effects of individual socio-demographic characteristics. Neighborhood variables include built environment, poverty level and urbanicity at the county level. Among the built environment variables, a poorer street connectivity and a more prominent presence of fast-food restaurants are associated with a higher obesity risk (especially for areas of certain urbanicity levels). Analysis of data subsets divided by areas of different urbanicity levels and by gender reveals the variability of effects of independent variables, more so for the neighborhood variables than individual variables. This implies that some obesity risk factors are geographically specific and vary between men and women. The results lend support to the role of built environment in influencing people’s health behavior and outcome, and promote public policies that need to be geographically adaptable and sensitive to the diversity of demographic groups. PMID:25864019

Built environment and obesity by urbanicity in the U.S.

PubMed

Xu, Yanqing; Wang, Fahui

2015-07-01

Based on the data from the Behavioral Risk Factor Surveillance System 2012, this study examines the association of neighborhood built environments with individual physical inactivity and obesity in the U.S. Multilevel modeling is used to control for the effects of individual socio-demographic characteristics. Neighborhood variables include built environment, poverty level and urbanicity at the county level. Among the built environment variables, a poorer street connectivity and a more prominent presence of fast-food restaurants are associated with a higher obesity risk (especially for areas of certain urbanicity levels). Analysis of data subsets divided by areas of different urbanicity levels and by gender reveals the variability of effects of independent variables, more so for the neighborhood variables than individual variables. This implies that some obesity risk factors are geographically specific and vary between men and women. The results lend support to the role of built environment in influencing people's health behavior and outcome, and promote public policies that need to be geographically adaptable and sensitive to the diversity of demographic groups. Copyright © 2015 Elsevier Ltd. All rights reserved.

Contribution of land use changes to meteorological parameters in Greater Jakarta: Case 17 January 2014

NASA Astrophysics Data System (ADS)

Nuryanto, D. E.; Pawitan, H.; Hidayat, R.; Aldrian, E.

2018-05-01

The impact of land use changes on meteorological parameters during a heavy rainfall event on 17 January 2014 in Greater Jakarta (GJ) was examined using the Weather Research and Forecasting (WRF) model. This study performed two experimental simulation methods. The first WRF simulation uses default land use (CTL). The second simulation applies the experiment by changing the size of urban and built-up land use (SCE). The Global Forecast System (GFS) data is applied to provide more realistic initial and boundary conditions for the nested model domains (3 km, 1 km). The simulations were initiated at 00:00 UTC January 13, 2014 and the period of modeling was equal to six days. The air temperature and the precipitation pattern in GJ shows a good agreement between the observed and simulated data. The results show a consistent significant contribution of urban development and accompany land use changes in air temperature and precipitation. According to the model simulation, urban and built-up land contributed about 6% of heavy rainfall and about 0.2 degrees of air temperatures in the morning. Simulations indicate that new urban developments led to an intensification and expansion of the rain area. The results can support the decision-making of flooding and watershed management.

Bumble bees (Bombus spp) along a gradient of increasing urbanization.

PubMed

Ahrné, Karin; Bengtsson, Jan; Elmqvist, Thomas

2009-01-01

Bumble bees and other wild bees are important pollinators of wild flowers and several cultivated crop plants, and have declined in diversity and abundance during the last decades. The main cause of the decline is believed to be habitat destruction and fragmentation associated with urbanization and agricultural intensification. Urbanization is a process that involves dramatic and persistent changes of the landscape, increasing the amount of built-up areas while decreasing the amount of green areas. However, urban green areas can also provide suitable alternative habitats for wild bees. We studied bumble bees in allotment gardens, i.e. intensively managed flower rich green areas, along a gradient of urbanization from the inner city of Stockholm towards more rural (periurban) areas. Keeping habitat quality similar along the urbanization gradient allowed us to separate the effect of landscape change (e.g. proportion impervious surface) from variation in habitat quality. Bumble bee diversity (after rarefaction to 25 individuals) decreased with increasing urbanization, from around eight species on sites in more rural areas to between five and six species in urban allotment gardens. Bumble bee abundance and species composition were most affected by qualities related to the management of the allotment areas, such as local flower abundance. The variability in bumble bee visits between allotment gardens was higher in an urban than in a periurban context, particularly among small and long-tongued bumble bee species. Our results suggest that allotment gardens and other urban green areas can serve as important alternatives to natural habitats for many bumble bee species, but that the surrounding urban landscape influences how many species that will be present. The higher variability in abundance of certain species in the most urban areas may indicate a weaker reliability of the ecosystem service pollination in areas strongly influenced by human activity.

The impact of interventions to promote physical activity in urban green space: a systematic review and recommendations for future research.

PubMed

Hunter, Ruth F; Christian, Hayley; Veitch, Jenny; Astell-Burt, Thomas; Hipp, J Aaron; Schipperijn, Jasper

2015-01-01

Evidence is mounting on the association between the built environment and physical activity (PA) with a call for intervention research. A broader approach which recognizes the role of supportive environments that can make healthy choices easier is required. A systematic review was undertaken to assess the effectiveness of interventions to encourage PA in urban green space. Five databases were searched independently by two reviewers using search terms relating to 'physical activity', 'urban green space' and 'intervention' in July 2014. Eligibility criteria included: (i) intervention to encourage PA in urban green space which involved either a physical change to the urban green space or a PA intervention to promote use of urban green space or a combination of both; and (ii) primary outcome of PA. Of the 2405 studies identified, 12 were included. There was some evidence (4/9 studies showed positive effect) to support built environment only interventions for encouraging use and increasing PA in urban green space. There was more promising evidence (3/3 studies showed positive effect) to support PAprograms or PA programs combined with a physical change to the built environment, for increasing urban green space use and PA of users. Recommendations for future research include the need for longer term follow-up post-intervention, adequate control groups, sufficiently powered studies, and consideration of the social environment, which was identified as a significantly under-utilized resource in this area. Interventions that involve the use of PA programs combined with a physical change to the built environment are likely to have a positive effect on PA. Robust evaluations of such interventions are urgently required. The findings provide a platform to inform the design, implementation and evaluation of future urban green space and PAintervention research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of urban design on microclimate and thermal comfort outdoors in warm-humid Dar es Salaam, Tanzania

NASA Astrophysics Data System (ADS)

Yahia, Moohammed Wasim; Johansson, Erik; Thorsson, Sofia; Lindberg, Fredrik; Rasmussen, Maria Isabel

2018-03-01

Due to the complexity of built environment, urban design patterns considerably affect the microclimate and outdoor thermal comfort in a given urban morphology. Variables such as building heights and orientations, spaces between buildings, plot coverage alter solar access, wind speed and direction at street level. To improve microclimate and comfort conditions urban design elements including vegetation and shading devices can be used. In warm-humid Dar es Salaam, the climate consideration in urban design has received little attention although the urban planning authorities try to develop the quality of planning and design. The main aim of this study is to investigate the relationship between urban design, urban microclimate, and outdoor comfort in four built-up areas with different morphologies including low-, medium-, and high-rise buildings. The study mainly concentrates on the warm season but a comparison with the thermal comfort conditions in the cool season is made for one of the areas. Air temperature, wind speed, mean radiant temperature (MRT), and the physiologically equivalent temperature (PET) are simulated using ENVI-met to highlight the strengths and weaknesses of the existing urban design. An analysis of the distribution of MRT in the areas showed that the area with low-rise buildings had the highest frequency of high MRTs and the lowest frequency of low MRTs. The study illustrates that areas with low-rise buildings lead to more stressful urban spaces than areas with high-rise buildings. It is also shown that the use of dense trees helps to enhance the thermal comfort conditions, i.e., reduce heat stress. However, vegetation might negatively affect the wind ventilation. Nevertheless, a sensitivity analysis shows that the provision of shade is a more efficient way to reduce PET than increases in wind speed, given the prevailing sun and wind conditions in Dar es Salaam. To mitigate heat stress in Dar es Salaam, a set of recommendations and guidelines on how to develop the existing situation from microclimate and thermal comfort perspectives is outlined. Such recommendations will help architects and urban designers to increase the quality of the outdoor environment and demonstrate the need to create better urban spaces in harmony with microclimate and thermal comfort.

Effect of urban design on microclimate and thermal comfort outdoors in warm-humid Dar es Salaam, Tanzania.

PubMed

Yahia, Moohammed Wasim; Johansson, Erik; Thorsson, Sofia; Lindberg, Fredrik; Rasmussen, Maria Isabel

2018-03-01

Due to the complexity of built environment, urban design patterns considerably affect the microclimate and outdoor thermal comfort in a given urban morphology. Variables such as building heights and orientations, spaces between buildings, plot coverage alter solar access, wind speed and direction at street level. To improve microclimate and comfort conditions urban design elements including vegetation and shading devices can be used. In warm-humid Dar es Salaam, the climate consideration in urban design has received little attention although the urban planning authorities try to develop the quality of planning and design. The main aim of this study is to investigate the relationship between urban design, urban microclimate, and outdoor comfort in four built-up areas with different morphologies including low-, medium-, and high-rise buildings. The study mainly concentrates on the warm season but a comparison with the thermal comfort conditions in the cool season is made for one of the areas. Air temperature, wind speed, mean radiant temperature (MRT), and the physiologically equivalent temperature (PET) are simulated using ENVI-met to highlight the strengths and weaknesses of the existing urban design. An analysis of the distribution of MRT in the areas showed that the area with low-rise buildings had the highest frequency of high MRTs and the lowest frequency of low MRTs. The study illustrates that areas with low-rise buildings lead to more stressful urban spaces than areas with high-rise buildings. It is also shown that the use of dense trees helps to enhance the thermal comfort conditions, i.e., reduce heat stress. However, vegetation might negatively affect the wind ventilation. Nevertheless, a sensitivity analysis shows that the provision of shade is a more efficient way to reduce PET than increases in wind speed, given the prevailing sun and wind conditions in Dar es Salaam. To mitigate heat stress in Dar es Salaam, a set of recommendations and guidelines on how to develop the existing situation from microclimate and thermal comfort perspectives is outlined. Such recommendations will help architects and urban designers to increase the quality of the outdoor environment and demonstrate the need to create better urban spaces in harmony with microclimate and thermal comfort.

Large-Eddy Simulation of the Impact of Great Garuda Project on Wind and Thermal Environment over Built-Up Area in Jakarta

NASA Astrophysics Data System (ADS)

Yucel, M.; Sueishi, T.; Inagaki, A.; Kanda, M.

2017-12-01

`Great Garuda' project is an eagle-shaped offshore structure with 17 artificial islands. This project has been designed for the coastal protection and land reclamation of Jakarta due to catastrophic flooding in the city. It offers an urban generation for 300.000 inhabitants and 600.000 workers in addition to its water safety goal. A broad coalition of Indonesian scientists has criticized the project for being negative impacts on the surrounding environment. Despite the vast research by Indonesian scientist on maritime environment, studies on wind and thermal environment over built-up area are still lacking. However, the construction of the various islands off the coast may result changes in wind patterns and thermal environment due to the alteration of the coastline and urbanization in the Jakarta Bay. Therefore, it is important to understand the airflow within the urban canopy in case of unpredictable gust events. These gust events may occur through the closely-packed high-rise buildings and pedestrians may be harmed from such gusts. Accordingly, we used numerical simulations to investigate the impact of the sea wall and the artificial islands over built-up area and, the intensity of wind gusts at the pedestrian level. Considering the fact that the size of turbulence organized structure sufficiently large computational domain is required. Therefore, a 19.2km×4.8km×1.0 km simulation domain with 2-m resolution in all directions was created to explicitly resolve the detailed shapes of buildings and the flow at the pedestrian level. This complex computation was accomplished by implementing a large-eddy simulation (LES) model. Two case studies were conducted considering the effect of realistic surface roughness and upward heat flux. Case_1 was conducted based on the current built environment and Case_2 for investigating the effect of the project on the chosen coastal region of the city. Fig.1 illustrates the schematic of the large-eddy simulation domains of two cases with and without Great Garuda Sea Wall and 17 artificial islands. 3D model of Great Garuda is shown in Fig.2. In addition to the cases mentioned above, the simulation will be generated assigning more realistic heat flux outputs from energy balance model and, inflow boundary conditions coupling with mesoscale model (Weather Research and Forecast model).

Predicting Intra-Urban Population Densities in Africa using SAR and Optical Remote Sensing Data

NASA Astrophysics Data System (ADS)

Linard, C.; Steele, J.; Forget, Y.; Lopez, J.; Shimoni, M.

2017-12-01

The population of Africa is predicted to double over the next 40 years, driving profound social, environmental and epidemiological changes within rapidly growing cities. Estimations of within-city variations in population density must be improved in order to take urban heterogeneities into account and better help urban research and decision making, especially for vulnerability and health assessments. Satellite remote sensing offers an effective solution for mapping settlements and monitoring urbanization at different spatial and temporal scales. In Africa, the urban landscape is covered by slums and small houses, where the heterogeneity is high and where the man-made materials are natural. Innovative methods that combine optical and SAR data are therefore necessary for improving settlement mapping and population density predictions. An automatic method was developed to estimate built-up densities using recent and archived optical and SAR data and a multi-temporal database of built-up densities was produced for 48 African cities. Geo-statistical methods were then used to study the relationships between census-derived population densities and satellite-derived built-up attributes. Best predictors were combined in a Random Forest framework in order to predict intra-urban variations in population density in any large African city. Models show significant improvement of our spatial understanding of urbanization and urban population distribution in Africa in comparison to the state of the art.

The Evolution of the Sustainability Assessment Tool SBToolPT: From Buildings to the Built Environment

PubMed Central

Bragança, Luís

2014-01-01

This paper analyses the current trends in sustainability assessment. After about 15 years from the launch of sustainability assessment tools, focused on buildings evaluation, the paradigm of sustainability assessment tools is changing from the building scale to the built environment scale. Currently European cities and cities around the world are concerned with sustainable development, as well as its evolution. Cities seek a way to adapt to contemporary changes, in order to meet the required needs and ensure population's well-being. Considering this, the new generations of sustainability assessment tools are being developed to be used to guide and help cities and urban areas to become more sustainable. Following the trend of the most important sustainability assessment tools, the sustainability assessment tool SBToolPT is also developing its version for assessing the sustainability of the built environment, namely, the urban planning projects and the urban regeneration projects, to be developed in Portugal, the SBToolPT-UP. The application of the methodology to three case studies will demonstrate its feasibility; at the same time this will identify the best practices which will serve as reference for new projects, thereby assisting the development of the tool. PMID:24592171

The evolution of the sustainability assessment tool SBToolPT: from buildings to the built environment.

PubMed

Castanheira, Guilherme; Bragança, Luís

2014-01-01

This paper analyses the current trends in sustainability assessment. After about 15 years from the launch of sustainability assessment tools, focused on buildings evaluation, the paradigm of sustainability assessment tools is changing from the building scale to the built environment scale. Currently European cities and cities around the world are concerned with sustainable development, as well as its evolution. Cities seek a way to adapt to contemporary changes, in order to meet the required needs and ensure population's well-being. Considering this, the new generations of sustainability assessment tools are being developed to be used to guide and help cities and urban areas to become more sustainable. Following the trend of the most important sustainability assessment tools, the sustainability assessment tool SBTool(PT) is also developing its version for assessing the sustainability of the built environment, namely, the urban planning projects and the urban regeneration projects, to be developed in Portugal, the SBTool(PT)-UP. The application of the methodology to three case studies will demonstrate its feasibility; at the same time this will identify the best practices which will serve as reference for new projects, thereby assisting the development of the tool.

Bases of the scientific conception of the “green frame” designing in urban areas for providing ecological safety of the urban environment

NASA Astrophysics Data System (ADS)

Bespalov, V.; Kotlyarova, E.

2017-10-01

In modern conditions of a stable urban areas development special place is occupied by the problem of ecological security of built-up areas, including residential, recreational, industrial areas and objects of transport and engineering infrastructure. The main results of the study are to establish the basis of formation of the concept of choice of energy-efficient technologies and tools of forming an ecologically efficient “green frame” of urban areas on the basis of a single integrated scientific concept. Analysis allowed us to divide the measures for improvement into the following main groups: organizational and planning, engineering and technical and special engineering and environmental. The significance of these results for the construction industry, including transport infrastructure, is to increase the level of environmental safety in the construction and reconstruction of urban areas due to the organization of their improvement on the basis suggested by the authors scientific approach. Its basis is integrated accounting of the natural and climatic features of the landscaping territory, the types and level of environmental impact of negative anthropogenic factors, the features of architectural and planning solutions of the existing or projected on the studied area, the structure and types of green spaces and their functional ecological properties.

Polychlorinated biphenyl concentrations, accumulation rates in soil from atmospheric deposition and analysis of their affecting landscape variables along an urban-rural gradient in Shanghai, China.

PubMed

Fang, Shubo; Cui, Qu; Matherne, Brian; Hou, Aixin

2017-11-01

This study initiated an in-situ soil experimental system to quantify the annual dynamics of polychlorinated biphenyl (PCB) congener's concentrations and accumulation rates in soil from atmosphere deposition in a rural-urban fringe, and correlated them by landscape physical and demographic variables in the area. The results showed that the concentrations of all PCB congeners significantly increased with the sampling time (p < 0.05); nearly all the PCB congener concentrations decreased while moving outwards from the urban center. The moderate average concentrations along the gradient for PCB 8, 18, and 28 were 31.003, 18.825, and 19.505 ng g-1, respectively. Tetra-CBs including PCB 44, 52, 66, and 77 were 10.243, 31.214, 8.330 and 9.530 ng g-1, respectively. Penta-CBs including PCB 101, 105, 118, and 126 were 9.465, 7.896, 17.703, and 6.363 ng g-1, respectively. Hexa-CBs including PCB 128, 138, 153, 170, 180, and 187 were 6.798, 11.522, 4.969, 6.722, 6.317, and 8.243 ng g-1 respectively. PCB 195, 206, and 209 were 8.259, 9.506, and 14.169 ng g-1, respectively. Most of the PCB congeners had a higher accumulation rate approximately 28 km from the urban center. The computed variables were found to affect the soil PCB concentrations with a threshold effect (p < 0.05). Regression analysis showed that the thresholds were 10-20 km, 1 km/km 2 , 30%, and 20% for distance, road density, population change index, and built-up area percentage, respectively. It was concluded that factors related to industrial development, traffic, and urban sprawling (i.e. built-up areas expanding) were the sources of PCBs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Omah displacement and utilization from rural to urban areas, as green design lifestyle

NASA Astrophysics Data System (ADS)

Fajarwati, Ade Ariyani Sari

2017-11-01

Building a house in urban area is very costly and also leaving a bunch amount of construction waste. Many efforts were made to reduce the load of this waste. However, the high demand of residences in metropolitan makes the waste problem needs to be solved together. Based on this problem, author chooses Omah, - a Javanese traditional house, which is built, based on the traditional system of life of Javanese people - displacement from rural to urban area as the alternative solution, as it uses selected materials from nature by considering the sustainability and preservation for future generation. The wooden building is built based on traditional construction system that follows Javanese principles and traditional calculation, based on philosophy and cosmology in the community. This paper will covers utilization of Omah in urban area as an implementation of green design, which refers to the concepts of reuse, reduce, recycle and responsibility. Through expert interviews and field surveys in urban and rural areas, author collected data needed for this paper. Although the functionality of the building is different from rural to urban requirements, the phenomenon of Omah displacement from Javanese habitat to urban living area is well accepted and becomes an interesting trend.

Assessing the impact of urban land cover composition on CO2 flux

NASA Astrophysics Data System (ADS)

Becker, K.; Hinkle, C.

2013-12-01

Urbanization is an ever increasing trend in global land use change, and has been identified as a key driver of CO2 emissions. Therefore, understanding how urbanization affects CO2 flux across a range of climatic zones and development patterns is critical to projecting the impact of future land use on CO2 flux dynamics. A growing number of studies are applying the eddy covariance method to urban areas to quantify the CO2 flux dynamics of these systems. However, interpretation of eddy covariance data in these urban systems presents a challenge, particularly in areas with high heterogeneity due to a mixing of built and green space. Here we present a study aimed at establishing a relationship between land cover composition and CO2 flux for a heterogeneous urban area of Orlando, FL. CO2 flux has been measured at this site for > 4 years using an open path eddy covariance system. Land cover at this site was classified into built and green space, and relative weight of both land covers were calculated for each 30 min CO2 flux measurement using the Schuepp model and a source area based on +/- one standard deviation of wind direction. The results of this analysis established a relationship between built land cover and CO2 flux within the measured footprint of this urban area. These results, in combination with future projected land use data, will be a valuable resource for providing insight into the impact of future urbanization on CO2 flux dynamics in this region.

A new approach for river flood extent delineation in rural and urban areas combining RADARSAT-2 imagery and flood recurrence interval data

NASA Astrophysics Data System (ADS)

Tanguy, Marion; Bernier, Monique; Chokmani, Karem

2015-04-01

When a flood hits an inhabited area, managers and services responsible for public safety need precise, reliable and up to date maps of the areas affected by the flood, in order to quickly roll out and to coordinate the adequate intervention and assistance plans required to limit the human and material damages caused by the disaster. Synthetic aperture radar (SAR) sensors are now considered as one of the most adapted tool for flood detection and mapping in a context of crisis management. Indeed, due to their capacity to acquire data night and day, in almost all meteorological conditions, SAR sensors allow the acquisition of synoptic but detailed views of the areas affected by the flood, even during the active phases of the event. Moreover, new generation sensors such as RADARSAT-2, TerraSAR-X, COSMO-SkyMed, are providing very high resolution images of the disaster (down to 1m ground resolution). Further, critical improvements have been made on the temporal repetitivity of acquisitions and on data availability, through the development of satellite constellations (i.e the four COSMO-Skymed or the Sentinel-1A and 1B satellites) and thanks to the implementation of the International Charter "Space and Major Disasters", which guarantees high priority images acquisition and delivery with 4 to 12 hours. If detection of open water flooded areas is relatively straightforward with SAR imagery, flood detection in built-up areas is often associated with important issues. Indeed, because of the side looking geometry of the SAR sensors, structures such as tall vegetation and structures parallel to the satellite direction of travel may produce shadow and layover effects, leading to important over and under-detections of flooded pixels. Besides, the numerous permanent water-surfaces like radar response areas present in built-up environments, such as parking lots, roads etc., may be mixed up with flooded areas, resulting in substantial inaccuracies in the final flood map. In spite of the many efforts recently done toward the improvements of the accuracy of the processing algorithms for flood detection in urban areas with high resolution SAR imagery, these algorithms still encounter difficulties to detect urban flooded pixels with precision. The difficulties do not seem to be only ascribable to the choice of SAR image processing methods, but can also be imputed to the limitations of the SAR imaging technique itself in urban areas. We propose a fully automatic and effective approach for near-real time delineation of urban and rural flooded areas, which combines the capacity of SAR imagery to detect open water areas, and explicit hydrodynamic characteristics of the region affected by the flood, expressed through flood recurrence interval data. This innovative approach has been tested with RADARSAT-2 Fine and Ultrafine Mode images acquired during the 2011 Richelieu River flooding, in Canada. It proved successful in accurately delineating flooding in urban and rural areas, with a RMSE inferior to 2 pixels.

The global potential of local peri-urban food production

NASA Astrophysics Data System (ADS)

Kriewald, Steffen; Garcia Cantu Ros, Anselmo; Sterzel, Till; Kropp, Jürgen P.

2013-04-01

One big challenge for the rest of the 21st century will be the massive urbanisation. It is expected that more than 7 out of 10 persons will live in a city by the year 2050. Crucial developments towards a sustainable future will therefore take place in cities. One important approach for a sustainable city development is to re-localize food production and to close urban nutrient cycles through better waste management. The re-location of food production avoids CO2 emissions from transportation of food to cities and can also generate income for inhabitants. Cities are by definition locations where fertility accumulates. As cities are often built along rivers, their soils are often fertile. Furthermore, labour force and the possibility of producing fertilizer from human fecal matter within the city promises sustainable nutrients cycles. Although urban and peri-urban agriculture can be found in many cities worldwide and already have a substantial contribution to food supply, it has not jet been comprehensibly structured by research. We combine several worldwide data sets to determine the supply of cities with regional food production, where regional is defined as a production that occurs very close to the consumption within the peri-urban area. Therefore, urban areas are not defined by administrative boundaries but by connected built-up urban areas, and peri-urban area by the surrounding area with the same size multiplied with a scaling parameter. Both together accumulate to an urban-bio-region (UBR). With regard to national food consumption, a linear program achieves the best possible yield on agricultural areas and allows the computation of the fraction of population, which can be nourished. Additionally, several climate scenarios and different dietary patterns were considered. To close the gap between single case studies and to provide a quantitative overview of the global potential of peri-urban food production we used high resolution land-use data Global Land Cover Service (GlobCover), the global agricultural yield dataset from the Global Agro-ecological Zones (GAEZ) and census population data from the Global Rural-Urban Mapping Project, Version 1 (GRUMPv1) to estimate the potential of 2838 UBR worldwide. With regard to making use of local circumstances, the results of potential worldwide peri-urban agriculture emphasize the ongoing investigation of sustainable transitions of the socio-ecologic system. Identifying areas for increased food production while maintaining the natural resources and the urban needs will be a major task for cities in future.

Land Use and Land Cover (LULC) Change Detection in Islamabad and its Comparison with Capital Development Authority (CDA) 2006 Master Plan

NASA Astrophysics Data System (ADS)

Hasaan, Zahra

2016-07-01

Remote sensing is very useful for the production of land use and land cover statistics which can be beneficial to determine the distribution of land uses. Using remote sensing techniques to develop land use classification mapping is a convenient and detailed way to improve the selection of areas designed to agricultural, urban and/or industrial areas of a region. In Islamabad city and surrounding the land use has been changing, every day new developments (urban, industrial, commercial and agricultural) are emerging leading to decrease in vegetation cover. The purpose of this work was to develop the land use of Islamabad and its surrounding area that is an important natural resource. For this work the eCognition Developer 64 computer software was used to develop a land use classification using SPOT 5 image of year 2012. For image processing object-based classification technique was used and important land use features i.e. Vegetation cover, barren land, impervious surface, built up area and water bodies were extracted on the basis of object variation and compared the results with the CDA Master Plan. The great increase was found in built-up area and impervious surface area. On the other hand vegetation cover and barren area followed a declining trend. Accuracy assessment of classification yielded 92% accuracies of the final land cover land use maps. In addition these improved land cover/land use maps which are produced by remote sensing technique of class definition, meet the growing need of legend standardization.

Urban expansion simulation and the spatio-temporal changes of ecosystem services, a case study in Atlanta Metropolitan area, USA.

PubMed

Sun, Xiao; Crittenden, John C; Li, Feng; Lu, Zhongming; Dou, Xiaolin

2018-05-01

Urban expansion can lead to land use changes and, hence, threatens the ecosystems. Understanding the effects of urbanization on ecosystem services (ESs) can provide scientific guidance for land use planning and the protection of ESs. We established a framework to assess the spatial distributions of ESs based on land use changes in the Atlanta Metropolitan area (AMA) from 1985 to 2012. A new comprehensive ecosystem service (CES) index was developed to reflect the comprehensive level of ESs. Associated with the influential factors, we simulated the business as usual scenario in 2030. Four alternative scenarios, including more compact growth (MCG), riparian vegetation buffer (RVB), soil conservation (SC), and combined development (CD) scenarios were developed to explore the optimal land use strategies which can enhance the ESs. The results showed that forest and wetland had the greatest decreases, while low and high intensity built-up lands had the greatest increases. The values of CES and most of ESs decreased significantly due to the sprawling expansion of built-up land. The scenario analysis revealed that the CD scenario performs best in CES value, while it performs the worst in food supply. Compared with the RVB and SC scenarios, MCG scenario is a more optimal land use strategy to enhance the ESs without at the expense of food supply. To integrate multiple ESs into land use planning and decision making, corresponding land management policies and ecological engineering measures should be implemented to enhance: (1) the water yield and water purification in urban core counties, (2) the carbon storage, habitat quality, and recreational opportunity in counties around the core area, and (3) the soil conservation and food supply in surrounding suburban counties. The land use strategies and ecological engineering measures in this study can provide references for enhancing the ESs in the AMA and other metropolitan areas. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling Košice Green Roofs Maps

NASA Astrophysics Data System (ADS)

Poorova, Zuzana; Vranayova, Zuzana

2017-06-01

The need to house population in urban areas is expected to rise to 66% in 2050, according to United Nations. The replacement of natural permeable green areas with concrete constructions and hard surfaces will be noticed. The densification of existing built-up areas is responsible for the decreasing vegetation, which results in the lack of evapotranspiration cooling the air. Such decreasing vegetation causes urban heat islands. Since roofs and pavements have a very low albedo, they absorb a lot of sunlight. Several studies have shown that natural and permeable surfaces, as in the case of green roofs, can play crucial role in mitigating this negative climate phenomenon and providing higher efficiency for the building, leading to savings. Such as water saving, what is the main idea of this research.

Influence of urbanization-driven land use/cover change on climate: The case of Addis Ababa, Ethiopia

NASA Astrophysics Data System (ADS)

Arsiso, Bisrat Kifle; Mengistu Tsidu, Gizaw; Stoffberg, Gerrit Hendrik; Tadesse, Tsegaye

2018-06-01

Land use change is the second most important anthropogenic influence on climate beside the emission of greenhouse gases. Urbanization is leading to significant land use changes in Africa since the continent is undergoing rapid urbanization and population growth in recent decades. Addis Ababa is one of these fast growing cities in the continent. Therefore, detection of land use change is very important to identify its impact on climate and sustainable land use management of the city. The study used Landsat images to generate land use/land cover change map for the city. The normalized difference vegetation index (NDVI) is used to detect the major changes of vegetation cover occurred between 1986 and 2011 as a result of land use and land cover change. Downscaled HadCM3 simulations under A2 and B2 emission scenarios is used to investigate future urban heat island (UHI) over the city of Addis Ababa. In the city, the analysis of Landsat images has shown that the built-up areas have increased by 121.88 km2 within the last 25 years. This finding is consistent with NDVI images taken over the same period that reveal a decline in vegetation cover. The impact of the urbanization-driven land use/cover change has resulted in notable nocturnal urban heat island (UHI) as revealed from an average increase in minimum temperature of 1.5 °C at the centre of the city relative to rural site over the 1960-2001 period. The mean of the 2006-2010 spatial minimum temperature anomaly with respect to the base period mean of 1981-2005 is consistent with the observed UHI. The temperature in the central areas (both commercial and residential sectors) of Addis Ababa is warmer than the surrounding areas. The thermal gradient increase from about 1.44 °C at the centre (Arada, Addis Ketema, Lideta and Kirkos) to 0.21 °C at the peripheral parts of the city (Gulele, Bole, Nefasilk-Lafto, Kolfe Keranio and east of Yeka sub-cities) transecting across the hot (high-density urban) to moderately warm to cool (non-built-up) areas. However, the maximum temperature and rainfall exhibit variability that follows topographic differences. Future urban climate change projections of urban heat island formation under A2 and B2 emission scenarios show that the nocturnal UHI will be intense in winter or dry season episodes in the city. The highest urban warming is from October to December (2.5 °C to 3.2 °C) during 2050s and 2080s.

Growth Scenarios for the City of Guangzhou, China: Transferability and Confirmability

NASA Astrophysics Data System (ADS)

Lehner, A.; Kraus, V.; Wei, C.; Steinnocher, K.

2016-09-01

This work deals with the development of urban growth scenarios and the prevision of the spatial distribution of built-up area and population for the urban area of the city of Guangzhou in China. Using freely-available data, including remotely sensed data as well as census data from the ground, expenditure of time and costs shall remain low. Guangzhou, one of the biggest cities within the Pearl River Delta, has faced an enormous economic and urban growth during the last three decades. Due to its economical and spatial characteristics it is a promising candidate for urban growth scenarios. The monitoring and prediction of urban growth comprises data of population and give them a spatial representation. The model, originally applied for the Indian city Ahmedabad, is used for urban growth scenarios. Therefore, transferability and confirmability of the model are evaluated. Challenges that may occur by transferring a model for urban growth from one region to another are discussed. With proposing the use of urban remote sensing and freely available data, urban planners shall be fitted with a comprehensible and simple tool to be able to contribute to the future challenge Smart Growth.

The impact of urbanization on CO2 emissions in China: an empirical study using 1980-2014 provincial data.

PubMed

Wang, Shijin; Li, Cunfang

2018-01-01

Towns and cities are not only the focus of attention for their consumption of energy and resources; they are also scrutinized closely for their emissions of greenhouse gases. China's urbanization level now exceeds 50%, but there is still much disparity compared with the level of urbanization in developed countries. This study selects China's urban population and carbon emissions data for the years 1980-2014 and discusses the timing and cause effect of urbanization and the corresponding carbon emissions using the Granger causality test and an error correction model (ECM) then uses STIRPAT models to extract six indicators to measure the quality of urbanization, namely, the level of urbanization, area of built-up regions, added value of tertiary industries, disposable income per capita, green areas per capita, and energy intensity. These six indicators represent population agglomeration, the expansion of urban areas, industrial agglomeration, quality of life improvements, ecological conservation, and technological improvements, respectively. The study divides 29 provinces in China into three groups based on the quality of urbanization and analyzes the impacts of the six indicators of urbanization quality on carbon emissions. The findings show that the impacts of different factors on carbon emissions vary substantially among the provinces. Finally, the study uses the findings to give suggestions on how to develop low-carbon urbanization.

Photogrammetric Point Clouds Generation in Urban Areas from Integrated Image Matching and Segmentation

NASA Astrophysics Data System (ADS)

Ye, L.; Wu, B.

2017-09-01

High-resolution imagery is an attractive option for surveying and mapping applications due to the advantages of high quality imaging, short revisit time, and lower cost. Automated reliable and dense image matching is essential for photogrammetric 3D data derivation. Such matching, in urban areas, however, is extremely difficult, owing to the complexity of urban textures and severe occlusion problems on the images caused by tall buildings. Aimed at exploiting high-resolution imagery for 3D urban modelling applications, this paper presents an integrated image matching and segmentation approach for reliable dense matching of high-resolution imagery in urban areas. The approach is based on the framework of our existing self-adaptive triangulation constrained image matching (SATM), but incorporates three novel aspects to tackle the image matching difficulties in urban areas: 1) occlusion filtering based on image segmentation, 2) segment-adaptive similarity correlation to reduce the similarity ambiguity, 3) improved dense matching propagation to provide more reliable matches in urban areas. Experimental analyses were conducted using aerial images of Vaihingen, Germany and high-resolution satellite images in Hong Kong. The photogrammetric point clouds were generated, from which digital surface models (DSMs) were derived. They were compared with the corresponding airborne laser scanning data and the DSMs generated from the Semi-Global matching (SGM) method. The experimental results show that the proposed approach is able to produce dense and reliable matches comparable to SGM in flat areas, while for densely built-up areas, the proposed method performs better than SGM. The proposed method offers an alternative solution for 3D surface reconstruction in urban areas.

Land use/cover change detection and urban sprawl analysis in Bandar Abbas city, Iran.

PubMed

Dadras, Mohsen; Shafri, Helmi Zulhaidi Mohd; Ahmad, Noordin; Pradhan, Biswajeet; Safarpour, Sahabeh

2014-01-01

The process of land use change and urban sprawl has been considered as a prominent characteristic of urban development. This study aims to investigate urban growth process in Bandar Abbas city, Iran, focusing on urban sprawl and land use change during 1956-2012. To calculate urban sprawl and land use changes, aerial photos and satellite images are utilized in different time spans. The results demonstrate that urban region area has changed from 403.77 to 4959.59 hectares between 1956 and 2012. Moreover, the population has increased more than 30 times in last six decades. The major part of population growth is related to migration from other parts the country to Bandar Abbas city. Considering the speed of urban sprawl growth rate, the scale and the role of the city have changed from medium and regional to large scale and transregional. Due to natural and structural limitations, more than 80% of barren lands, stone cliffs, beach zone, and agricultural lands are occupied by built-up areas. Our results revealed that the irregular expansion of Bandar Abbas city must be controlled so that sustainable development could be achieved.

Land Use/Cover Change Detection and Urban Sprawl Analysis in Bandar Abbas City, Iran

PubMed Central

Mohd Shafri, Helmi Zulhaidi; Ahmad, Noordin; Pradhan, Biswajeet; Safarpour, Sahabeh

2014-01-01

The process of land use change and urban sprawl has been considered as a prominent characteristic of urban development. This study aims to investigate urban growth process in Bandar Abbas city, Iran, focusing on urban sprawl and land use change during 1956–2012. To calculate urban sprawl and land use changes, aerial photos and satellite images are utilized in different time spans. The results demonstrate that urban region area has changed from 403.77 to 4959.59 hectares between 1956 and 2012. Moreover, the population has increased more than 30 times in last six decades. The major part of population growth is related to migration from other parts the country to Bandar Abbas city. Considering the speed of urban sprawl growth rate, the scale and the role of the city have changed from medium and regional to large scale and transregional. Due to natural and structural limitations, more than 80% of barren lands, stone cliffs, beach zone, and agricultural lands are occupied by built-up areas. Our results revealed that the irregular expansion of Bandar Abbas city must be controlled so that sustainable development could be achieved. PMID:25276858

Earthquake vulnerability assessment of buildings of ward no. 8 of Haldwani-Kathgodam Municipal Corporation, Uttarakhand, India

NASA Astrophysics Data System (ADS)

Bora, Kritika; Pande, Ravindra K.

2017-07-01

"Earthquake does not kill people; it is the building which kills people". Earthquake is a sudden event below the surface of the earth which results in vertical and horizontal waves that causes destruction. The main aim of this research is to bring into light the unplanned and non-engineered construction practices growing in the Urban areas. Lack of space and continuous migration from hills has resulted in Multistorey construction. The present study is based on primary data collection through Rapid Visual Screening for the assessment of vulnerability of buildings. "Haldwani-Kathgodam being a new Municipal Corporation located in the foot hills of Himalayas is facing same problem. The seismic zonation brings this area into zone 4 of damage risk. Therefore an assessment to estimate the risk of the built up environment is important. This paper presents a systematic and useful way of assessing physical vulnerability of buildings. The present paper will show how the growing pressure on urban area tends to make the built up environment vulnerable towards seismic activities. The challenge today is to make our living environment safe for living. The day by day growing population pressure on urban area as a migration trend in developing countries is leading to high rise building, no planning and reckless construction. For the sake of saving some money people usually do not take the approval from structural engineer. This unplanned and haphazard construction proves non-resistant towards earthquake and brings lives and properties to death and a stand still. The total no. of household in the current study area is 543 whereas the total population is 2497 (2011). The recent formation of Himalayas makes the area more sensitive towards seismic event. The closeness to the Main Boundary thrust brings it to zone 4 in the Seismic Zonation of India i.e., High Damage Risk Zone

Albedo and its Relationship to Land Cover and the Urban Heat Island in the Boston Metropolitan Region

NASA Astrophysics Data System (ADS)

Trlica, A.; Hutyra, L.; Wang, J.; Schaaf, C.; Erb, A.

2016-12-01

The urban built environment creates key changes in the biophysical character of the landscape, including the creation of Urban Heat Islands (UHIs) with increased near-surface temperatures in and around cities. Alteration in surface albedo is believed to partially drive UHIs through greater absorption of solar energy, but few empirical studies have specifically quantified albedo across a heterogeneous urban landscape, or investigated linkages between albedo, the UHI, and other surface socio-biophysical characteristics at a high enough spatial resolution to discern urban-scale features. This study used data derived from observations by Landsat and other remote sensing platforms to measure albedo across a varied urban landscape centered on Boston, Massachusetts, and examined the relationship between albedo, several key indicators of urban surface character (canopy cover, impervious fraction, and population density) and land surface temperature at resolutions of both 30 and 500 m. Albedo tended to be lower in areas with highest urbanization intensity indicators compared to rural undeveloped areas, and areas with lower albedo tended also to have higher median daytime summer surface temperatures. A k-means classification utilizing all the data available for each pixel revealed several distinct patterns of urban land cover corresponding mainly to the density of population and constructed surfaces and their impact on tree canopy cover. Mean 30-m summer surface temperatures ranged from 40.0 °C (SD = 2.6) in urban core areas to 26.2 °C (SD = 1.1) in nearby forest, but we only observed correspondingly large albedo decreases in the highest density urban core, with mean albedo of 0.116 (SD = 0.015) compared with 0.155 (SD = 0.015) in forest. Observations show that lower albedo in the Boston metropolitan region may be an important component of the local UHI in the most densely built-up urban core regions, while the UHI temperature effect in less densely settled peripheral regions is more likely to be driven primarily by reduced evapotranspiration due to diminished tree canopy and greater impervious surface coverage. These results empirically characterize surface albedo across a suite of land cover categories and biophysical characteristics and reveal how albedo relates to surface temperatures in this urbanized region.

Urban biophysical composition and its impact on thermal changes and ecosystem production

NASA Astrophysics Data System (ADS)

Sannigrahi, Srikanta; Rahmat, Shahid; Bhatt, Sandeep

2017-04-01

Human driving forces, especially, urbanization, population pressure, and socioeconomic development are significantly changing the efficiency of ecosystem service provision in an urban ecosystem. Greater Hyderabad Municipal Corporation (GHMC) is the sixth largest urban metropolitan region in India had faced an alarming pace of urban expansion from 1973 to 2015. MODerate Resolution Imaging Spectroradiometer (MODIS) thermal products MOD11A2 and surface reflectance products MOD09A1 were employed in this work to simulate areal and temporal dynamics of Urban Heat Island (UHI) and Diurnal Temperature Range (DTR) of the GHMC region from 2002 to 2015. A Light Use Efficiency (LUE) based Vegetation Photosynthesis Model (VPM) was adopted in this work to quantify Net Primary Production (NPP) and to assess the spatiotemporal changes of NPP during 2002 to 2015. MODIS yearly NPP products MOD17A3 were applied here for the purpose of model validation. Linear Spectral Mixture Analysis (LSMA) technique was employed in this research to generate impervious surface fraction image of GHMC. Spatially explicit gas regulation service included as a regulatory ecosystem service to assess the trade-off between economic viability and ecosystem conservation. Acute urban expansion (over 200%) is mainly accounted to changes the Land Surface Temperature (LST) over 3°C to 4°C in the inner city region during 1991 to 2015. Surface vegetation and moisture dynamics have been evaluated by incorporating Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-up Index (NDBI), Normalized Difference Bareness Index (NDBaI) and Land Surface Water Index (LSWI) for the year of 2002, 2011 and 2015, respectively. The four distinct UHI cluster, i.e. H-H, H-L, L-H & L-L were retrieved from the segmentation of estimated LST using Local Indicators Spatial Autocorrelation (LISA) technique. Further, the Getis-Ord-Gi hotspot analysis method has been employed to identify the local proximity of spatial hot and cold UHI clusters. The areal coverage of built-up urban class was changed from 208.11sq.km in 1973 to 419.55 sq.km in 2015 with 5.03 sq.km/year expansion rate. The selected biophysical indices are found highly sensitive to the changes in land use and land cover (LULC). LST hotspot (H-H) in 2002 was observed in the central and the southeast portion of the region due to the presence of higher thermal anomalies and high concentration of LST (°C). The Island (H-L) part of the city was mostly covered by the built-up urban area in 2002 exhibiting the highest concentration of LST, whereas the mean LST (°C) of the neighboring region is below than the average. GiZScore with low standard deviation value proven the existence of active hotspot of LST and UHI over the central urbanized area in GHMC.A strong negative correlation has found between the selected human driving forces: UHI, LST, population density, settlement density and impervious fraction with NPP ensembles the facts of human control in an urban ecosystem. This study demonstrated the necessity of proper quantification and valuation of urban ecosystem services to achieve effective and efficient decision for urban ecosystem management.

Occurrence and Distribution of Pesticides in the St. Lucie River Watershed, South-Central Florida, 2000-01, Based on Enzyme-Linked Immunosorbent Assay (ELISA) Screening

USGS Publications Warehouse

Lietz, A.C.

2003-01-01

The St. Lucie River watershed is a valuable estuarine ecosystem and resource in south-central Florida. The watershed has undergone extensive changes over the last century because of anthropogenic activities. These activities have resulted in a complex urban and agricultural drainage network that facilitates the transport of contaminants, including pesticides, to the primary canals and then to the estuary. Historical data indicate that aquatic life criteria for selected pesticides have been exceeded. To address this concern, a reconnaissance was conducted to assess the occurrence and distribution of selected pesticides within the St. Lucie River watershed. Numerous water samples were collected from 37 sites among various land-use categories (urban/built-up, citrus, cropland/pastureland, and inte-grated). Samples were collected at inflow points to primary canals (C-23, C-24, and C-44) and at control structures along these canals from October 2000 to September 2001. Samples were screened for four pesticide classes (triazines, chloroacetanilides, chlorophenoxy compounds, and organophosphates) by using Enzyme-Linked Immunosorbent Assay (ELISA) screening. A temporal distribution of pesticides within the watershed was made based on samples collected at the integrated sites during different rainfall events between October 2000 and September 2001. Triazines were detected in 32 percent of the samples collected at the integrated sites. Chloroacetanilides were detected in 60 percent of the samples collected at the integrated sites, with most detections occurring at one site. Chlorophenoxy compounds were detected in 17 percent of the samples collected at the integrated sites. Organophosphates were detected in only one sample. A spatial distribution and range of concentration of pesticides at the 37 sampling sites in the watershed were determined among land-use categories. Triazine concentrations ranged from highest to lowest in the citrus, urban/built-up, and integrated areas, respectively. The highest median triazine concentration was found in the cropland/pastureland area. Chloroacetanilide concentra-tions ranged from highest to lowest in the citrus, integrated, urban/built-up, and cropland/pastureland areas, respectively. Chlorophenoxy compound concentrations ranged from highest to lowest in the urban/built-up, integrated, citrus, and cropland/pastureland areas, respectively. The maximum concentrations of triazines, chloroacetanilides, and chlorophenoxy compounds were 0.63, 1.0, and 14 micrograms per liter, respectively. Organophosphate was detected once at an integrated site at a concentration of 0.20 microgram per liter. Currently, the U.S. Environmental Protection Agency has no aquatic life guidelines for atrazine and metolachlor. However, assuming that all triazine and metolachlor concentrations from ELISA and gas chromatography/mass spectrometry (GC/MS) analyses were the result of atrazine and metolachlor detections, no concentrations exceeded the Canadian aquatic life guidelines for atrazine and metolachlor. One organophosphate detection (0.2 microgram per liter) did exceed the U.S. Environmental Protection Agency aquatic life guideline for chlorpyrifos. The deethylatrazine/atrazine ratio (DAR) is an important indicator of atrazine transport in the environment. The DAR ranged from 0.25 to 0.33, indicating that postapplication runoff was the most likely source of atrazine to the environment at the time of sampling. Deisopropylatrazine is a metabolite of atrazine and structurally similar compounds, such as simazine and cyanazine. The deisopropylatrazine/deethylatrazine ratio (D2R) is an indicator of nonpoint sources of deisopropylatrazine to the environment. The ratio ranged from 1 to 3 in this study, indicating simazine was an important source of deisopropylatrazine to the environment at the time of sampling, as opposed to atrazine alone. Confirmation analyses by GC/MS for triazines detected by ELISA indicated t

An examination of land use impacts of flooding induced by sea level rise

NASA Astrophysics Data System (ADS)

Song, Jie; Fu, Xinyu; Gu, Yue; Deng, Yujun; Peng, Zhong-Ren

2017-03-01

Coastal regions become unprecedentedly vulnerable to coastal hazards that are associated with sea level rise. The purpose of this paper is therefore to simulate prospective urban exposure to changing sea levels. This article first applied the cellular-automaton-based SLEUTH model (Project Gigalopolis, 2016) to calibrate historical urban dynamics in Bay County, Florida (USA) - a region that is greatly threatened by rising sea levels. This paper estimated five urban growth parameters by multiple-calibration procedures that used different Monte Carlo iterations to account for modeling uncertainties. It then employed the calibrated model to predict three scenarios of urban growth up to 2080 - historical trend, urban sprawl, and compact development. We also assessed land use impacts of four policies: no regulations; flood mitigation plans based on the whole study region and on those areas that are prone to experience growth; and the protection of conservational lands. This study lastly overlaid projected urban areas in 2030 and 2080 with 500-year flooding maps that were developed under 0, 0.2, and 0.9 m sea level rise. The calibration results that a substantial number of built-up regions extend from established coastal settlements. The predictions suggest that total flooded area of new urbanized regions in 2080 would be more than 25 times that under the flood mitigation policy, if the urbanization progresses with few policy interventions. The joint model generates new knowledge in the domain between land use modeling and sea level rise. It contributes to coastal spatial planning by helping develop hazard mitigation schemes and can be employed in other international communities that face combined pressure of urban growth and climate change.

A Web-GIS Procedure Based on Satellite Multi-Spectral and Airborne LIDAR Data to Map the Road blockage Due to seismic Damages of Built-Up Urban Areas

NASA Astrophysics Data System (ADS)

Costanzo, Antonio; Montuori, Antonio; Silva, Juan Pablo; Silvestri, Malvina; Musacchio, Massimo; Buongiorno, Maria Fabrizia; Stramondo, Salvatore

2016-08-01

In this work, a web-GIS procedure to map the risk of road blockage in urban environments through the combined use of space-borne and airborne remote sensing sensors is presented. The methodology concerns (1) the provision of a geo-database through the integration of space-borne multispectral images and airborne LiDAR data products; (2) the modeling of building vulnerability, based on the corresponding 3D geometry and construction time information; (3) the GIS-based mapping of road closure due to seismic- related building collapses based on the building characteristic height and the width of the road. Experimental results, gathered for the Cosenza urban area, allow demonstrating the benefits of both the proposed approach and the GIS-based integration of multi-platforms remote sensing sensors and techniques for seismic road assessment purposes.

Six decades of urban growth using remote sensing and GIS in the city of Bandar Abbas, Iran

NASA Astrophysics Data System (ADS)

Dadras, Mohsen; Zulhaidi Mohd Shafri, Helmi; Ahmad, Noordin; Pradhan, Biswajeet; Safarpour, Sahabeh

2014-06-01

Bandar Abbas is the capital city of Hormozgan province, is the south of Iran. The city has witnessed rapid growth in the last three decades, mostly because of its economic, commercial and social attractions. However, forms and operations of urban sprawl may vary in important manners according to determine geographical and historical characteristics, and these difference need to be reviewed with creation geodatabase of spatial and attribute data during past periods until now of urban formation and expansion. We implemented this research to understand Bandar Abbas city growth dynamic during last six decades using aerial photo, Remote Sensing (RS) data and Geographical Information System (GIS), to investigate its sprawl for the during six decades and to prepare a basis for urban planning and management. We calibrated it with geospatial data derived from a time series of aerial photos and satellite images. Treated remote sensing data covering the six decades were used to calculate land use/cover and urban growth. The application of classification techniques to the remote sensing data enabled the extraction of eight main types of land use: agricultural, barren, coastal, hole, river, rocky hill, urban, and built-up. Growth was calculated through Shannon's entropy model. The urbanized area increased from 403.77 ha to 4959.59 ha from 1956 to 2012, a rate almost five times that of the population growth observed in the same period. Such findings make the case of Bandar Abbas important for several reasons. First, Bandar Abbas has undergone a rapid increase in urban sprawl according to urban growth indicators. Second, the urban sprawl quickly grew from medium-sized to large a process considered inappropriate according to physical and structural limitations on urban growth. Lastly, the excessive extension of the built-up boundary in the city resulted in the loss of coastal land and open space, two main sources of tourist attraction and economic sustainable development.

Geospatial Strategy for Adverse Impact of Urban Heat Island in upper atmospheres of the earth Mountain Areas using LANDSAT ETM+ Sensors

NASA Astrophysics Data System (ADS)

Kumar, Amit; Vandana, Vandana

2016-07-01

We are living in the age of the rapidly growing population and changing environmental conditions with advanced technical capacity. This has been resulting in widespread land cover change. Among several human-induced environmental and urban thermal problems are reported to be negatively affecting urban residents in many ways. Urban Heat Islands exist in many large cities especially metropolitan cities and can significantly affect the permafrost layer in mountain areas. The adverse effect of urban heat island has become the subject of numerous studies in recent decades and is reflected in many major mountain cities around the world. The built-up structures in urbanized areas considerably alter land cover thereby affecting thermal energy flow which leads to the development of elevated surface and air temperature. The phenomenon Urban Heat Island implies 'island' of high temperature in cities, surrounded by relatively lower temperature in rural areas. The Urban Heat Island for the temporal period is estimated using geospatial techniques which are then utilized for the impact assessment of the climate of the surrounding regions and how it reduce the sustainability of the natural resources like air, vegetation. The knowledge of surface temperature is important for the study of urban climate and human health. The rapid growth of industries in peri-urban areas results in excessive warming and variations in weather conditions. It leads to soil degradation in frozen areas due to high temperature which leads to melting of snow in mountain areas Remotely sensed data of thermal infrared band in the region of 10.4-12.5 µm of EMR spectrum, available from LANDSAT- ETM+ is proved to be very helpful to identify urban heat islands. Thermal infrared data acquired during the daytime and night time can be used to monitor the heat island associated with urban areas as well as atmospheric pollution. The present paper describes the methodology and resolution dynamic urban heat island change on climate and soil using geospatial approach for Haridwar district of Uttrakhand. NDVI were generated using daytime LANDSAT ETM+ image of November 1990, 2000 and 2015. The temperature of various land use and land cover categories was estimated. In Haridwar district, the temperature is inversely related and negatively correlated with NDVI value. The paper considers this dimension and calculated UHI at multiple scales through surface conditions such as vegetation. The major part of the field were conceded out in moderate summer conditions due to rainfall, yet the heat island intensities obtained in the study were comparable to those observed in earlier studies. Moreover, very high UHI was observed in the later phase of the experiments when usual summer conditions were restored. Also, the present study has showed that heat island effect need not be limited to a particular temperature epoch which signals towards the increasing dominance of anthropogenic heat emissions in rapidly developing cities such as Haridwar District in Uttrakhand, India. The use of the technological resources should be such that it does not affect the sustainability of natural resources. For compensation of the adverse effect of UHI, the urban built up cover should be reduced to an extent but in real, it is not possible due to the proclivity of the human towards urbanization. A thick subsurface layer of soil that remains below freezing point throughout the year, occurring chiefly in polar regions.

Built-Up Area and Land Cover Extraction Using High Resolution Pleiades Satellite Imagery for Midrand, in Gauteng Province, South Africa

NASA Astrophysics Data System (ADS)

Fundisi, E.; Musakwa, W.

2017-09-01

Urban areas, particularly in developing countries face immense challenges such as climate change, poverty, lack of resources poor land use management systems, and week environmental management practices. Mitigating against these challenges is often hampered by lack of data on urban expansion, urban footprint and land cover. To support the recently adopted new urban agenda 2030 there is need for the provision of information to support decision making in the urban areas. Earth observation has been identified as a tool to foster sustainable urban planning and smarter cities as recognized by the new urban agenda, because it is a solution to unavailability of data. Accordingly, this study uses high resolution EO data Pleiades satellite imagery to map and document land cover for the rapidly expanding area of Midrand in Johannesburg, South Africa. An unsupervised land cover classification of the Pleiades satellite imagery was carried out using ENVI software, whereas NDVI was derived using ArcGIS software. The land cover had an accuracy of 85% that is highly adequate to document the land cover in Midrand. The results are useful because it provides a highly accurate land cover and NDVI datasets at localised spatial scale that can be used to support land use management strategies within Midrand and the City of Johannesburg South Africa.

Cost, accuracy, and consistency comparisons of land use maps made from high-altitutde aircraft photography and ERTS imagery

USGS Publications Warehouse

Fitzpatrick, Katherine A.

1975-01-01

Accuracy analyses for the land use maps of the Central Atlantic Regional Ecological Test Site were performed for a 1-percent sample of the area. Researchers compared Level II land use maps produced at three scales, 1:24,000, 1:100,000, and 1:250,000 from high-altitude photography, with each other and with point data obtained in the field. They employed the same procedures to determine the accuracy of the Level I land use maps produced at 1:250,000 from high-altitude photography and color composite ERTS imagery. The accuracy of the Level II maps was 84.9 percent at 1:24,000, 77.4 percent at 1:100,000, and 73.0 percent at 1:250,000. The accuracy of the Level I 1:250,000 maps produced from high-altitude aircraft photography was 76.5 percent and for those produced from ERTS imagery was 69.5 percent The cost of Level II land use mapping at 1:24,000 was found to be high ($11.93 per km2 ). The cost of mapping at 1:100,000 ($1.75) was about 2 times as expensive as mapping at 1:250,000 ($.88), and the accuracy increased by only 4.4 percent. Level I land use maps, when mapped from highaltitude photography, were about 4 times as expensive as the maps produced from ERTS imagery, although the accuracy is 7.0 percent greater. The Level I land use category that is least accurately mapped from ERTS imagery is urban and built-up land in the non-urban areas; in the urbanized areas, built-up land is more reliably mapped.

What are hot and what are not in an urban landscape: quantifying and explaining the land surface temperature pattern in Beijing, China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuang, Wenhui; Liu, Yue; Dou, Yinyin

Understanding how landscape components affect the urban heat islands is crucial for urban ecological planning and sustainable development. The purpose of this research was to quantify the spatial pattern of land surface temperatures (LSTs) and associated heat fluxes in relation to land-cover types in Beijing, China, using portable infrared thermometers, thermal infrared imagers, and the moderate resolution imaging spectroradiometer. The spatial differences and the relationships between LSTs and the hierarchical landscape structure were analyzed with in situ observations of surface radiation and heat fluxes. Large LST differences were found among various land-use/land-cover types, urban structures, and building materials. Within themore » urban area, the mean LST of urban impervious surfaces was about 6–12°C higher than that of the urban green space. LSTs of built-up areas were on average 3–6°C higher than LSTs of rural areas. The observations for surface radiation and heat fluxes indicated that the differences were caused by different fractions of sensible heat or latent heat flux in net radiation. LSTs decreased with increasing elevation and normalized difference vegetation index. Variations in building materials and urban structure significantly influenced the spatial pattern of LSTs in urban areas. By contrast, elevation and vegetation cover are the major determinants of the LST pattern in rural areas. In summary, to alleviate urban heat island intensity, urban planners and policy makers should pay special attention to the selection of appropriate building materials, the reasonable arrangement of urban structures, and the rational design of landscape components.« less

What are hot and what are not in an urban landscape: quantifying and explaining the land surface temperature pattern in Beijing, China

DOE PAGES

Kuang, Wenhui; Liu, Yue; Dou, Yinyin; ...

2014-12-06

Understanding how landscape components affect the urban heat islands is crucial for urban ecological planning and sustainable development. The purpose of this research was to quantify the spatial pattern of land surface temperatures (LSTs) and associated heat fluxes in relation to land-cover types in Beijing, China, using portable infrared thermometers, thermal infrared imagers, and the moderate resolution imaging spectroradiometer. The spatial differences and the relationships between LSTs and the hierarchical landscape structure were analyzed with in situ observations of surface radiation and heat fluxes. Large LST differences were found among various land-use/land-cover types, urban structures, and building materials. Within themore » urban area, the mean LST of urban impervious surfaces was about 6–12°C higher than that of the urban green space. LSTs of built-up areas were on average 3–6°C higher than LSTs of rural areas. The observations for surface radiation and heat fluxes indicated that the differences were caused by different fractions of sensible heat or latent heat flux in net radiation. LSTs decreased with increasing elevation and normalized difference vegetation index. Variations in building materials and urban structure significantly influenced the spatial pattern of LSTs in urban areas. By contrast, elevation and vegetation cover are the major determinants of the LST pattern in rural areas. In summary, to alleviate urban heat island intensity, urban planners and policy makers should pay special attention to the selection of appropriate building materials, the reasonable arrangement of urban structures, and the rational design of landscape components.« less

Using Combination of Planar and Height Features for Detecting Built-Up Areas from High-Resolution Stereo Imagery

NASA Astrophysics Data System (ADS)

Peng, F.; Cai, X.; Tan, W.

2017-09-01

Within-class spectral variation and between-class spectral confusion in remotely sensed imagery degrades the performance of built-up area detection when using planar texture, shape, and spectral features. Terrain slope and building height are often used to optimize the results, but extracted from auxiliary data (e.g. LIDAR data, DSM). Moreover, the auxiliary data must be acquired around the same time as image acquisition. Otherwise, built-up area detection accuracy is affected. Stereo imagery incorporates both planar and height information unlike single remotely sensed images. Stereo imagery acquired by many satellites (e.g. Worldview-4, Pleiades-HR, ALOS-PRISM, and ZY-3) can be used as data source of identifying built-up areas. A new method of identifying high-accuracy built-up areas from stereo imagery is achieved by using a combination of planar and height features. The digital surface model (DSM) and digital orthophoto map (DOM) are first generated from stereo images. Then, height values of above-ground objects (e.g. buildings) are calculated from the DSM, and used to obtain raw built-up areas. Other raw built-up areas are obtained from the DOM using Pantex and Gabor, respectively. Final high-accuracy built-up area results are achieved from these raw built-up areas using the decision level fusion. Experimental results show that accurate built-up areas can be achieved from stereo imagery. The height information used in the proposed method is derived from stereo imagery itself, with no need to require auxiliary height data (e.g. LIDAR data). The proposed method is suitable for spaceborne and airborne stereo pairs and triplets.

Analysis of Urban Growth in Edwardsville Illinois Using Remote Sensing and Population Change

NASA Astrophysics Data System (ADS)

Onuoha, Hilda U.

Rapid urbanization is one of the many critical, global issues. This very significant social and economic phenomenon has brought about much debate in the past twenty years and has become a very important policy issue. Understanding its dynamics and patterns is important to develop appropriate policies and make more informed planning decisions. Many dimensions to the urban land growth have been identified in related literature including drivers, relationship with other factors like population, impacts, and methods of measurement. In this study, urban growth in the Edwardsville area (composed of Edwardsville and Glen Carbon, Illinois) is analyzed spatio-temporally using remote sensing and population change from 1990 to 2015. The objectives of this study are (a) identifying the major land use changes in the Edwardsville area from 1990 to 2015, (b) analyzing the rate of urban growth and its relationship to population change in the area from 1990 to 2015, (c) identifying the general pattern and direction of urban growth in the study area. Using multi-temporal satellite images to classify and derive changes in land cover classes during the study period, results showed that the land cover classes with major changes are the urban/built-up land and agricultural/grassland, with a steady increase in the former and steady decrease in the later. Results also show the highest rate of increase in urban land was between 2000 and 2010. In comparison to population, the both show increase over the study years but urban land shows a higher rate of increase indicating dispersion. To analyze urban growth pattern in the area, the study area was divided into three zones: NE, SE, and W. The SE zone showed the highest amount of the growth and from the results, the infill type of growth was inferred.

The effects of green areas on air surface temperature of the Kuala Lumpur city using WRF-ARW modelling and Remote Sensing technique

NASA Astrophysics Data System (ADS)

Isa, N. A.; Mohd, W. M. N. Wan; Salleh, S. A.; Ooi, M. C. G.

2018-02-01

Matured trees contain high concentration of chlorophyll that encourages the process of photosynthesis. This process produces oxygen as a by-product and releases it into the atmosphere and helps in lowering the ambient temperature. This study attempts to analyse the effect of green area on air surface temperature of the Kuala Lumpur city. The air surface temperatures of two different dates which are, in March 2006 and March 2016 were simulated using the Weather Research and Forecasting (WRF) model. The green area in the city was extracted using the Normalized Difference Vegetation Index (NDVI) from two Landsat satellite images. The relationship between the air surface temperature and the green area were analysed using linear regression models. From the study, it was found that, the green area was significantly affecting the distribution of air temperature within the city. A strong negative correlation was identified through this study which indicated that higher NDVI values tend to have lower air surface temperature distribution within the focus study area. It was also found that, different urban setting in mixed built-up and vegetated areas resulted in different distributions of air surface temperature. Future studies should focus on analysing the air surface temperature within the area of mixed built-up and vegetated area.

Understanding land use change impacts on microclimate using Weather Research and Forecasting (WRF) model

NASA Astrophysics Data System (ADS)

Li, Xia; Mitra, Chandana; Dong, Li; Yang, Qichun

2018-02-01

To explore potential climatic consequences of land cover change in the Kolkata Metropolitan Development area, we projected microclimate conditions in this area using the Weather Research and Forecasting (WRF) model driven by future land use scenarios. Specifically, we considered two land conversion scenarios including an urbanization scenario that all the wetlands and croplands would be converted to built-up areas, and an irrigation expansion scenario in which all wetlands and dry croplands would be replaced by irrigated croplands. Results indicated that land use and land cover (LULC) change would dramatically increase regional temperature in this area under the urbanization scenario, but expanded irrigation tended to have a cooling effect. In the urbanization scenario, precipitation center tended to move eastward and lead to increased rainfall in eastern parts of this region. Increased irrigation stimulated rainfall in central and eastern areas but reduced rainfall in southwestern and northwestern parts of the study area. This study also demonstrated that urbanization significantly reduced latent heat fluxes and albedo of land surface; while increased sensible heat flux changes following urbanization suggested that developed land surfaces mainly acted as heat sources. In this study, climate change projection not only predicts future spatiotemporal patterns of multiple climate factors, but also provides valuable insights into policy making related to land use management, water resource management, and agriculture management to adapt and mitigate future climate changes in this populous region.

HOTEX: An Approach for Global Mapping of Human Built-Up and Settlement Extent

NASA Technical Reports Server (NTRS)

Wang, Panshi; Huang, Chengquan; Tilton, James C.; Tan, Bin; Brown De Colstoun, Eric C.

2017-01-01

Understanding the impacts of urbanization requires accurate and updatable urban extent maps. Here we present an algorithm for mapping urban extent at global scale using Landsat data. An innovative hierarchical object-based texture (HOTex) classification approach was designed to overcome spectral confusion between urban and nonurban land cover types. VIIRS nightlights data and MODIS vegetation index datasets are integrated as high-level features under an object-based framework. We applied the HOTex method to the GLS-2010 Landsat images to produce a global map of human built-up and settlement extent. As shown by visual assessments, our method could effectively map urban extent and generate consistent results using images with inconsistent acquisition time and vegetation phenology. Using scene-level cross validation for results in Europe, we assessed the performance of HOTex and achieved a kappa coefficient of 0.91, compared to 0.74 from a baseline method using per-pixel classification using spectral information.

Quantitative Analysis of Intra Urban Growth Modeling using socio economic agents by combining cellular automata model with agent based model

NASA Astrophysics Data System (ADS)

Singh, V. K.; Jha, A. K.; Gupta, K.; Srivastav, S. K.

2017-12-01

Recent studies indicate that there is a significant improvement in the urban land use dynamics through modeling at finer spatial resolutions. Geo-computational models such as cellular automata and agent based model have given evident proof regarding the quantification of the urban growth pattern with urban boundary. In recent studies, socio- economic factors such as demography, education rate, household density, parcel price of the current year, distance to road, school, hospital, commercial centers and police station are considered to the major factors influencing the Land Use Land Cover (LULC) pattern of the city. These factors have unidirectional approach to land use pattern which makes it difficult to analyze the spatial aspects of model results both quantitatively and qualitatively. In this study, cellular automata model is combined with generic model known as Agent Based Model to evaluate the impact of socio economic factors on land use pattern. For this purpose, Dehradun an Indian city is selected as a case study. Socio economic factors were collected from field survey, Census of India, Directorate of economic census, Uttarakhand, India. A 3X3 simulating window is used to consider the impact on LULC. Cellular automata model results are examined for the identification of hot spot areas within the urban area and agent based model will be using logistic based regression approach where it will identify the correlation between each factor on LULC and classify the available area into low density, medium density, high density residential or commercial area. In the modeling phase, transition rule, neighborhood effect, cell change factors are used to improve the representation of built-up classes. Significant improvement is observed in the built-up classes from 84 % to 89 %. However after incorporating agent based model with cellular automata model the accuracy improved from 89 % to 94 % in 3 classes of urban i.e. low density, medium density and commercial classes. Sensitivity study of the model indicated that southern and south-west part of the city have shown improvement and small patches of growth are also observed in the north western part of the city.The study highlights the growing importance of socio economic factors and geo-computational modeling approach on changing LULC of newly growing cities of modern India.

[Spatial scale effect of urban land use landscape pattern in Shanghai City].

PubMed

Xu, Li-Hua; Yue, Wen Ze; Cao, Yu

2007-12-01

Based on geographic information system (GIS) and remote sensing (RS) techniques, the landscape classes of urban land use in Shanghai City were extracted from SPOT images with 5 m spatial resolution in 2002, and then, the classified data were applied to quantitatively explore the change patterns of several basic landscape metrics at different scales. The results indicated that landscape metrics were sensitive to grain- and extent variance. Urban landscape pattern was spatially dependent. In other words, different landscape metrics showed different responses to scale. The resolution of 40 m was an intrinsic observing scale for urban landscape in Shanghai City since landscape metrics showed random characteristics while the grain was less than 40 m. The extent of 24 km was a symbol scale in a series of extents, which was consistent with the boundary between urban built-up area and suburban area in Shanghai City. As a result, the extent of 12 km away from urban center would be an intrinsic handle scale for urban landscape in Shanghai City. However, due to the complexity of urban structure and asymmetry of urban spatial expansion, the intrinsic handle scale was not regular extent, and the square with size of 24 km was just an approximate intrinsic extent for Shanghai City.

[Land use change and its effects on ecosystem services value in Ji' nan City of Shandong Province, East China].

PubMed

Liu, Jin-Yong; Kong, Fan-Hua; Yin, Hai-Wei; Yan, Wei-Jiao; Sun, Chang-Feng; Xu, Feng

2013-05-01

Based on the GIS software platform, referring to the China 'Terrestrial ecosystem services per unit area value', and by using transition matrix, Costanza evaluation formula, and sensitivity analysis, this paper studied the change characteristics of land use and ecosystem services value in Ji' nan City in 1989-2009. During the study period, the built-up area in the City increased by 99.65 km2, while agriculture land and green space reduced by 103.21 km2, 90.4% of which was taken by the built-up land. The total ecosystem services value decreased from 256.22 x 10(6) yento 214.16 x 10(6) yen, with a decrement of 42.06 x 10(6) yen, mainly due to the decrease in the areas of agriculture land and green space. For the sustainable development of the population, resources, and environment in Ji'nan City, future urban planning should pay more attention on the natural resources protection, reasonable planning of land use structure, and maintenance of ecosystem stability and balance.

The Effects of the Urban Built Environment on Mental Health: A Cohort Study in a Large Northern Italian City.

PubMed

Melis, Giulia; Gelormino, Elena; Marra, Giulia; Ferracin, Elisa; Costa, Giuseppe

2015-11-20

Mental health (MH) has a relevant burden on the health of populations. Common MH disorders (anxiety and non-psychotic depression) are well associated to socioeconomic individual and neighborhood characteristics, but little is known about the influence of urban structure. We analyzed among a Turin (Northwest Italy) urban population the association at area level of different urban structure characteristics (density, accessibility by public transport, accessibility to services, green and public spaces) and consumption of antidepressants. Estimates were adjusted by individual socio-demographic variables (education, housing tenure, employment) and contextual social environment (SE) variables (social and physical disorder, crime rates). Data was extracted from the Turin Longitudinal Study (TLS)-a census-based cohort study following up prospectively the mortality and morbidity of the population. As expected, individual characteristics show the strongest association with antidepressant drug consumption, while among built environment (BE) indicators accessibility by public transport and urban density only are associated to MH, being slightly protective factors. Results from this study, in agreement with previous literature, suggest that BE has a stronger effect on MH for people who spend more time in the neighborhood. Therefore, this research suggests that good accessibility to public transport, as well as a dense urban structure (versus sprawl), could contribute to reduced risk of depression, especially for women and elderly, by increasing opportunities to move around and have an active social life.

Urban structure analysis of mega city Mexico City using multisensoral remote sensing data

NASA Astrophysics Data System (ADS)

Taubenböck, H.; Esch, T.; Wurm, M.; Thiel, M.; Ullmann, T.; Roth, A.; Schmidt, M.; Mehl, H.; Dech, S.

2008-10-01

Mega city Mexico City is ranked the third largest urban agglomeration to date around the globe. The large extension as well as dynamic urban transformation and sprawl processes lead to a lack of up-to-date and area-wide data and information to measure, monitor, and understand the urban situation. This paper focuses on the capabilities of multisensoral remotely sensed data to provide a broad range of products derived from one scientific field - remote sensing - to support urban managing and planning. Therefore optical data sets from the Landsat and Quickbird sensors as well as radar data from the Shuttle Radar Topography Mission (SRTM) and the TerraSAR-X sensor are utilised. Using the multi-sensoral data sets the analysis are scale-dependent. On the one hand change detection on city level utilising the derived urban footprints enables to monitor and to assess spatiotemporal urban transformation, areal dimension of urban sprawl, its direction, and the built-up density distribution over time. On the other hand, structural characteristics of an urban landscape - the alignment and types of buildings, streets and open spaces - provide insight in the very detailed physical pattern of urban morphology on higher scale. The results show high accuracies of the derived multi-scale products. The multi-scale analysis allows quantifying urban processes and thus leading to an assessment and interpretation of urban trends.

A Global Geospatial Ecosystem Services Estimate of Urban Agriculture

NASA Astrophysics Data System (ADS)

Clinton, Nicholas; Stuhlmacher, Michelle; Miles, Albie; Uludere Aragon, Nazli; Wagner, Melissa; Georgescu, Matei; Herwig, Chris; Gong, Peng

2018-01-01

Though urban agriculture (UA), defined here as growing of crops in cities, is increasing in popularity and importance globally, little is known about the aggregate benefits of such natural capital in built-up areas. Here, we introduce a quantitative framework to assess global aggregate ecosystem services from existing vegetation in cities and an intensive UA adoption scenario based on data-driven estimates of urban morphology and vacant land. We analyzed global population, urban, meteorological, terrain, and Food and Agriculture Organization (FAO) datasets in Google Earth Engine to derive global scale estimates, aggregated by country, of services provided by UA. We estimate the value of four ecosystem services provided by existing vegetation in urban areas to be on the order of 33 billion annually. We project potential annual food production of 100-180 million tonnes, energy savings ranging from 14 to 15 billion kilowatt hours, nitrogen sequestration between 100,000 and 170,000 tonnes, and avoided storm water runoff between 45 and 57 billion cubic meters annually. In addition, we estimate that food production, nitrogen fixation, energy savings, pollination, climate regulation, soil formation and biological control of pests could be worth as much as 80-160 billion annually in a scenario of intense UA implementation. Our results demonstrate significant country-to-country variability in UA-derived ecosystem services and reduction of food insecurity. These estimates represent the first effort to consistently quantify these incentives globally, and highlight the relative spatial importance of built environments to act as change agents that alleviate mounting concerns associated with global environmental change and unsustainable development.

The impact of urbanization during half a century on surface meteorology based on WRF model simulations over National Capital Region, India

NASA Astrophysics Data System (ADS)

Sati, Ankur Prabhat; Mohan, Manju

2017-10-01

An estimated 50% of the global population lives in the urban areas, and this percentage is projected to reach around 69% by the year 2050 (World Urbanization Prospects 2009). There is a considerable growth of urban and built-up area during the recent decades over National Capital Region (NCR) of India (17-fold increase in the urban extent). The proposed study estimates the land use land cover changes particularly changes to urban class from other land use types such as croplands, shrubland, open areas, and water bodies and quantify these changes for a span of about five decades. Further, the impact of these land use/land cover changes is examined on spatial and temporal variations of meteorological parameters using the Weather Research and Forecast (WRF) Model. The urbanized areas appear to be one of the regions with highest changes in the values of the fluxes and temperatures where during daytime, the surface sensible heat flux values show a noticeable increase of 60-70 W m-2 which commensurate with increase in urbanization. Similarly, the nighttime LST and T2m show an increase of 3-5 and 2-3 K, respectively. The diurnal temperature range (DTR) of LST and surface temperature also shows a decrease of about 5 and 2-3 K, respectively, with increasing urbanization. Significant decrease in the magnitude of surface winds and relative humidity is also observed over the areas converted to urban form over a period of half a century. The impacts shown here have serious implications on human health, energy consumption, ventilation, and atmospheric pollution.

Spatial heterogeneity and temporal evolution of malaria transmission risk in Dakar, Senegal, according to remotely sensed environmental data.

PubMed

Machault, Vanessa; Vignolles, Cécile; Pagès, Frédéric; Gadiaga, Libasse; Gaye, Abdoulaye; Sokhna, Cheikh; Trape, Jean-François; Lacaux, Jean-Pierre; Rogier, Christophe

2010-09-03

The United Nations forecasts that by 2050, more than 60% of the African population will live in cities. Thus, urban malaria is considered an important emerging health problem in that continent. Remote sensing (RS) and geographic information systems (GIS) are useful tools for addressing the challenge of assessing, understanding and spatially focusing malaria control activities. The objectives of the present study were to use high spatial resolution SPOT (Satellite Pour l'Observation de la Terre) satellite images to identify some urban environmental factors in Dakar associated with Anopheles arabiensis densities, to assess the persistence of these associations and to describe spatial changes in at-risk environments using a decadal time scale. Two SPOT images from the 1996 and 2007 rainy seasons in Dakar were processed to extract environmental factors, using supervised classification of land use and land cover, and a calculation of NDVI (Normalized Difference Vegetation Index) and distance to vegetation. Linear regressions were fitted to identify the ecological factors associated with An. arabiensis aggressiveness measured in 1994-97 in the South and centre districts of Dakar. Risk maps for populated areas were computed and compared for 1996 and 2007 using the results of the statistical models. Almost 60% of the variability in anopheline aggressiveness measured in 1994-97 was explained with only one variable: the built-up area in a 300-m radius buffer around the catching points. This association remained stable between 1996 and 2007. Risk maps were drawn by inverting the statistical association. The total increase of the built-up areas in Dakar was about 30% between 1996 and 2007. In proportion to the total population of the city, the population at high risk for malaria fell from 32% to 20%, whereas the low-risk population rose from 29 to 41%. Environmental data retrieved from high spatial resolution SPOT satellite images were associated with An. arabiensis densities in Dakar urban setting, which allowed to generate malaria transmission risk maps. The evolution of the risk was quantified, and the results indicated there are benefits of urbanization in Dakar, since the proportion of the low risk population increased while urbanization progressed.

Impacts of future urban expansion on summer climate and heat-related human health in eastern China.

PubMed

Cao, Qian; Yu, Deyong; Georgescu, Matei; Wu, Jianguo; Wang, Wei

2018-03-01

China is the largest and most rapidly urbanizing nation in the world, and is projected to add an additional 200 million city dwellers by the end of 2030. While this rapid urbanization will lead to vast expansion of built-up areas, the possible climate effect and associated human health impact remain poorly understood. Using a coupled urban-atmospheric model, we first examine potential effects of three urban expansion scenarios to 2030 on summer climate in eastern China. Our simulations indicate extensive warming up to 5°C, 3°C, and 2°C in regard to low- (>0%), high- (>75%), and 100% probability urban growth scenarios, respectively. The partitioning of available energy largely explains the changes in 2-m air temperatures, and increased sensible heat flux with higher roughness length of the underlying urban surface is responsible for the increase of nighttime planetary boundary layer height. In the extreme case (the low-probability expansion pathway), the agglomeration of impervious surfaces substantially reduces low-level atmospheric moisture, consequently resulting in large-scale precipitation reduction. However, the effect of near-surface warming far exceeds that of moisture reduction and imposes non-negligible thermal loads on urban residents. Our study, using a scenario-based approach that accounts for the full range of urban growth uncertainty by 2030, helps better evaluate possible regional climate effects and associated human health outcomes in the most rapidly urbanizing areas of China, and has practical implications for the development of sustainable urban regions that are resilient to changes in both mean and extreme conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cost-effectiveness and cost utility of community screening for glaucoma in urban India.

PubMed

John, Denny; Parikh, Rajul

2017-07-01

Population-based screening for glaucoma has been demonstrated to be cost-effective if targeted at high-risk groups such as older adults and those with a family history of glaucoma, and through use of a technician for conducting initial assessment rather than a medical specialist. This study attempts to investigate the cost-effectiveness of a hypothetical community screening and subsequent treatment programme for glaucoma in comparison with current practice (i.e. with no screening programme but with some opportunistic case finding) in the urban areas of India. A hypothetical screening programme for both primary open-angle glaucoma and angle-closure disease was built for a population aged between 40 and 69 years in the urban areas of India. Screening and treatment costs were obtained from an administrator of a tertiary eye hospital in India. The probabilities for the screening pathway were derived from published literature and expert opinion. The glaucoma prevalence rates for urban areas were adapted from the Chennai Glaucoma Study findings. A decision-analytical model using TreeAge Pro 2015 was built to model events, costs and treatment pathways. One-way sensitivity analyses were conducted. The introduction of a community screening programme for glaucoma is likely to be cost-effective, the estimated incremental cost-effectiveness ratio (ICER) values being 10,668.68 when compared with no screening programme and would treat an additional 4443 cases and prevent 1790 person-years of blindness over a 10-year period in the urban areas of India. Sensitivity analyses revealed that glaucoma prevalence rates across various age groups, screening uptake rate, follow-up compliance after screening, treatment costs and utility values of health states associated with medical and surgical treatment of glaucoma had an impact on the ICER values of the screening programme. In comparison with current practice (i.e. without a screening programme but with some opportunistic case finding), the introduction of a community screening programme for glaucoma for the 40-69 years age group is likely to be relatively cost-effective if implemented in the urban areas of India. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Low frequency dove coos vary across noise gradients in an urbanized environment.

PubMed

Guo, Fengyi; Bonebrake, Timothy C; Dingle, Caroline

2016-08-01

Urbanization poses a challenge to bird communication due to signal masking by ambient noise and reflective surfaces that lead to signal degradation. Bird species (especially oscines) have been shown to alter their singing behaviour to increase signal efficiency in highly urbanized environments. However, few studies on the effects of noise on song structure have included birds with low frequency vocal signals which may be especially vulnerable to noise pollution due to significant frequency overlap of their signals with traffic noise. We compared the perch coos of spotted doves (Streptopelia chinensis), a species with very low frequency vocalizations, in different background noise levels across urban and peri-urban areas in Hong Kong. We documented a 10% upward shift in the minimum frequency of coos of spotted doves across the noise gradient (a relatively small but significant shift), and a reduced maximum frequency in urban habitats with a higher density of built up area. Hong Kong doves had significantly higher minimum and maximum frequencies than doves from throughout their range (from mostly rural sites). Our results indicate that urban species with extremely low sound frequencies such as doves can alter their vocalizations in response to variable urban acoustic environments. Copyright © 2016 Elsevier B.V. All rights reserved.

Habitat Composition and Connectivity Predicts Bat Presence and Activity at Foraging Sites in a Large UK Conurbation

PubMed Central

Hale, James D.; Fairbrass, Alison J.; Matthews, Tom J.; Sadler, Jon P.

2012-01-01

Background Urbanization is characterized by high levels of sealed land-cover, and small, geometrically complex, fragmented land-use patches. The extent and density of urbanized land-use is increasing, with implications for habitat quality, connectivity and city ecology. Little is known about densification thresholds for urban ecosystem function, and the response of mammals, nocturnal and cryptic taxa are poorly studied in this respect. Bats (Chiroptera) are sensitive to changing urban form at a species, guild and community level, so are ideal model organisms for analyses of this nature. Methodology/Principal Findings We surveyed bats around urban ponds in the West Midlands conurbation, United Kingdom (UK). Sites were stratified between five urban land classes, representing a gradient of built land-cover at the 1 km2 scale. Models for bat presence and activity were developed using land-cover and land-use data from multiple radii around each pond. Structural connectivity of tree networks was used as an indicator of the functional connectivity between habitats. All species were sensitive to measures of urban density. Some were also sensitive to landscape composition and structural connectivity at different spatial scales. These results represent new findings for an urban area. The activity of Pipistrellus pipistrellus (Schreber 1774) exhibited a non-linear relationship with the area of built land-cover, being much reduced beyond the threshold of ∼60% built surface. The presence of tree networks appears to mitigate the negative effects of urbanization for this species. Conclusions/Significance Our results suggest that increasing urban density negatively impacts the study species. This has implications for infill development policy, built density targets and the compact city debate. Bats were also sensitive to the composition and structure of the urban form at a range of spatial scales, with implications for land-use planning and management. Protecting and establishing tree networks may improve the resilience of some bat populations to urban densification. PMID:22428015

Habitat composition and connectivity predicts bat presence and activity at foraging sites in a large UK conurbation.

PubMed

Hale, James D; Fairbrass, Alison J; Matthews, Tom J; Sadler, Jon P

2012-01-01

Urbanization is characterized by high levels of sealed land-cover, and small, geometrically complex, fragmented land-use patches. The extent and density of urbanized land-use is increasing, with implications for habitat quality, connectivity and city ecology. Little is known about densification thresholds for urban ecosystem function, and the response of mammals, nocturnal and cryptic taxa are poorly studied in this respect. Bats (Chiroptera) are sensitive to changing urban form at a species, guild and community level, so are ideal model organisms for analyses of this nature. We surveyed bats around urban ponds in the West Midlands conurbation, United Kingdom (UK). Sites were stratified between five urban land classes, representing a gradient of built land-cover at the 1 km(2) scale. Models for bat presence and activity were developed using land-cover and land-use data from multiple radii around each pond. Structural connectivity of tree networks was used as an indicator of the functional connectivity between habitats. All species were sensitive to measures of urban density. Some were also sensitive to landscape composition and structural connectivity at different spatial scales. These results represent new findings for an urban area. The activity of Pipistrellus pipistrellus (Schreber 1774) exhibited a non-linear relationship with the area of built land-cover, being much reduced beyond the threshold of ∼60% built surface. The presence of tree networks appears to mitigate the negative effects of urbanization for this species. Our results suggest that increasing urban density negatively impacts the study species. This has implications for infill development policy, built density targets and the compact city debate. Bats were also sensitive to the composition and structure of the urban form at a range of spatial scales, with implications for land-use planning and management. Protecting and establishing tree networks may improve the resilience of some bat populations to urban densification.

Mapping urban porosity and roughness characteristics as a mean of defining urban ventilation corridors

NASA Astrophysics Data System (ADS)

Wicht, Marzena; Wicht, Andreas; Osińska-Skotak, Katarzyna

2017-10-01

Cities can be characterized with the roughest aerodynamic boundaries, which results in the enhanced turbulent motion and increased drag effect. This leads to reduced wind speeds and directly increases negative effects of living within urban areas. Urban Heat Island, decreased air quality or densely built-up residential/industrial areas occur in many cities, both in temperate and tropical regions, and are included in these negative effects. This case study investigates Warsaw, the capital of Poland, representing a dense, urban environment, located in the temperate zone. It suffers from immense air pollution levels, as well as Urban Heat Island, and the local government is seeking ways to resolve these issues. Among many mitigation techniques, air restoration and exchange system were suggested as appropriate measures, as they address many of the aforementioned issues. The essential elements of such system are ventilation corridors. This paper describes mapping these corridors utilizing the morphometric methods of urban roughness aided by remote sensing data. We focus especially on the terrain topology and texture of single elements, including high vegetation canopy layer. This study considers DSM and different porosity of obstacles, deriving a new outlook at the morphometric methods as a way to improve them. The mapped areas of low roughness characteristics might be appointed as ventilation corridors and play a crucial role in air restoration and exchange system. They may also be included in further planning processes by the local government as preservation areas.

[Chikungunya and urban sprawl on Reunion Island].

PubMed

Aoustin, T

2012-03-01

The proportion of unsanitary housing in French overseas departments is much higher than in mainland France. Reunion Island is no exception to this fact. Between 80 and 90% of housing in Reunion Island was built by squatters with no legal claim or deed to the property. This has resulted in uncontrolled urban sprawl with living conditions reminiscent of those in developing countries. The absence of adequate drainage systems for sewage and rain water and the lack of properly organized garbage disposal that characterizes these sprawl areas constitutes a particularly favorable breeding ground for vector-borne diseases, especially chikungunya. Thus, implementing measures to control this type of settlement and to relocate of people out of existing sprawl areas constitutes a significant tool to control this epidemiological risk. Up to now, public officials have shown a clear reluctance to intervene in sprawl areas despite good knowledge of their location. On June 26th of this year, a law containing provisions relative to the control of urban sprawl and unsanitary housing in overseas departments and territories will come into effect. This law should provide public officials with the legal basis that has up until now been lacking to take action. Persistence in the "wait-and-see" attitude could lead to condemnation by French or European courts.

Offal dumping sites influence the relative abundance and roosting site selection of Black Kites (Milvus migrans govinda) in urban landscape: a study from Kolkata metropolis, India.

PubMed

Mazumdar, Subhendu; Ghose, Dipankar; Saha, Goutam Kumar

2017-12-14

Although Black Kites (Milvus migrans govinda) serve as major scavenging raptor in most of the urban areas, scientific studies on this important ecosystem service provider are almost non-existent in Indian context. The present study was carried out in a metropolis in eastern India to find out the factors influencing relative abundance and roosting site selection of Black Kites. Separate generalized linear models (GLMs) were performed considering encounter rate and roosting Black Kite abundance as response variables. The study conclusively indicated that encounter rates of Black Kites were significantly influenced by the presence of garbage dumps in its vicinity. Numbers of Black Kites were also higher in the roosting sites situated closer to garbage dumps and open spaces. In addition, expected counts of Black Kites significantly increased in roosting sites situated away from buildings and water bodies. However, built-up area and tree cover around the roosting sites had no influence on the abundance of Black Kites therein. With rapid urbanization and changing offal disposal patterns, our findings would be useful to ensure continued availability of food and roosting sites of Black Kites in urban areas.

Urban-development-induced Changes in the Diversity and Composition of the Soil Bacterial Community in Beijing.

PubMed

Yan, Bing; Li, Junsheng; Xiao, Nengwen; Qi, Yue; Fu, Gang; Liu, Gaohui; Qiao, Mengping

2016-12-09

Numerous studies have implicated urbanization as a major cause of loss of biodiversity. Most of them have focused on plants and animals, even though soil microorganisms make up a large proportion of that biodiversity. However, it is unclear how the soil bacterial community is affected by urban development. Here, paired-end Illumina sequencing of the 16 S rRNA gene at V4 region was performed to study the soil microbial community across Beijing's built-up area. Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, Gemmatimonadetes, Verrucomicrobia, Planctomycetes, and Chloroflexi were the dominant phyla in all samples, but the relative abundance of these phyla differed significantly across these concentric zones. The diversity and composition of the soil bacterial community were found to be closely correlated with soil pH. Variance partitioning analysis suggested that urban ring roads contributed 5.95% of the bacterial community variation, and soil environmental factors explained 17.65% of the variation. The results of the current work indicate that urban development can alter the composition and diversity of the soil microbial community, and showed pH to be a key factor in the shaping of the composition of the soil bacterial community. Urban development did have a strong impact on the bacterial community of urban soil in Beijing.

Urban-development-induced Changes in the Diversity and Composition of the Soil Bacterial Community in Beijing

NASA Astrophysics Data System (ADS)

Yan, Bing; Li, Junsheng; Xiao, Nengwen; Qi, Yue; Fu, Gang; Liu, Gaohui; Qiao, Mengping

2016-12-01

Numerous studies have implicated urbanization as a major cause of loss of biodiversity. Most of them have focused on plants and animals, even though soil microorganisms make up a large proportion of that biodiversity. However, it is unclear how the soil bacterial community is affected by urban development. Here, paired-end Illumina sequencing of the 16 S rRNA gene at V4 region was performed to study the soil microbial community across Beijing’s built-up area. Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, Gemmatimonadetes, Verrucomicrobia, Planctomycetes, and Chloroflexi were the dominant phyla in all samples, but the relative abundance of these phyla differed significantly across these concentric zones. The diversity and composition of the soil bacterial community were found to be closely correlated with soil pH. Variance partitioning analysis suggested that urban ring roads contributed 5.95% of the bacterial community variation, and soil environmental factors explained 17.65% of the variation. The results of the current work indicate that urban development can alter the composition and diversity of the soil microbial community, and showed pH to be a key factor in the shaping of the composition of the soil bacterial community. Urban development did have a strong impact on the bacterial community of urban soil in Beijing.

Earth Observation

NASA Image and Video Library

2012-08-09

ISS032-E-017635 (9 Aug. 2012) --- A nighttime view of Kuwait City is featured in this image photographed by an Expedition 32 crew member on the International Space Station. Seen at night Kuwait City, the capital of the small Persian Gulf state of Kuwait, contrasts dramatically with the dark surface of the Persian Gulf (top) and the very sparsely populated desert area (bottom). Night views also show at a glance some aspects of urban geography that are difficult to perceive in daylight images. Here the focus of radial traffic arteries and ?ring roads? guide the eye to the financial center of the city?on the cape extending into Kuwait Bay north of the First Ring Road. The numbering of the ring roads shows the progressive southward development of the city, towards the Seventh Ring Road which still lies outside the built-up area at lower right. The striking differences in color of city lighting also provide information on the urban geography. Areas with lighting of a green tinge are, in each case, newer residential districts. The town of Al Ahmadi (lower right), known for its verdant vegetation, was built in 1946 when oil was struck and stands out with its characteristic blue night lights. Kuwait International Airport, like most major airports around the globe, is particularly bright due to the high concentration of lights.

Understanding land use change impacts on microclimate using Weather Research and Forecasting (WRF) model

DOE PAGES

Li, Xia; Mitra, Chandana; Dong, Li; ...

2017-02-02

In order to explore potential climatic consequences of land cover change in the Kolkata Metropolitan Development area, we projected microclimate conditions in this area using the Weather Research and Forecasting (WRF) model driven by future land use scenarios. Specifically, we considered two land conversion scenarios including an urbanization scenario that all the wetlands and croplands would be converted to built-up areas, and an irrigation expansion scenario in which all wetlands and dry croplands would be replaced by irrigated croplands. Our results indicated that land use and land cover (LULC) change would dramatically increase regional temperature in this area under themore » urbanization scenario, but expanded irrigation tended to have a cooling effect. In the urbanization scenario, precipitation center tended to move eastward and lead to increased rainfall in eastern parts of this region. Increased irrigation stimulated rainfall in central and eastern areas but reduced rainfall in southwestern and northwestern parts of the study area. Our study also demonstrated that urbanization significantly reduced latent heat fluxes and albedo of land surface; while increased sensible heat flux changes following urbanization suggested that developed land surfaces mainly acted as heat sources. In this study, climate change projection not only predicts future spatiotemporal patterns of multiple climate factors, but also provides valuable insights into policy making related to land use management, water resource management, and agriculture management to adapt and mitigate future climate changes in this populous region.« less

Understanding land use change impacts on microclimate using Weather Research and Forecasting (WRF) model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xia; Mitra, Chandana; Dong, Li

In order to explore potential climatic consequences of land cover change in the Kolkata Metropolitan Development area, we projected microclimate conditions in this area using the Weather Research and Forecasting (WRF) model driven by future land use scenarios. Specifically, we considered two land conversion scenarios including an urbanization scenario that all the wetlands and croplands would be converted to built-up areas, and an irrigation expansion scenario in which all wetlands and dry croplands would be replaced by irrigated croplands. Our results indicated that land use and land cover (LULC) change would dramatically increase regional temperature in this area under themore » urbanization scenario, but expanded irrigation tended to have a cooling effect. In the urbanization scenario, precipitation center tended to move eastward and lead to increased rainfall in eastern parts of this region. Increased irrigation stimulated rainfall in central and eastern areas but reduced rainfall in southwestern and northwestern parts of the study area. Our study also demonstrated that urbanization significantly reduced latent heat fluxes and albedo of land surface; while increased sensible heat flux changes following urbanization suggested that developed land surfaces mainly acted as heat sources. In this study, climate change projection not only predicts future spatiotemporal patterns of multiple climate factors, but also provides valuable insights into policy making related to land use management, water resource management, and agriculture management to adapt and mitigate future climate changes in this populous region.« less

Understanding land use change impacts on microclimate using Weather Research and Forecasting (WRF) model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xia; Mitra, Chandana; Dong, Li

To explore potential climatic consequences of land cover change in the Kolkata Metropolitan Development area, we projected microclimate conditions in this area using the Weather Research and Forecasting (WRF) model driven by future land use scenarios. Specifically, we considered two land conversion scenarios including an urbanization scenario that all the wetlands and croplands would be converted to built-up areas, and an irrigation expansion scenario in which all wetlands and dry croplands would be replaced by irrigated croplands. Results indicated that land use and land cover (LULC) change would dramatically increase regional temperature in this area under the urbanization scenario, butmore » expanded irrigation tended to have a cooling effect. In the urbanization scenario, precipitation center tended to move eastward and lead to increased rainfall in eastern parts of this region. Increased irrigation stimulated rainfall in central and eastern areas but reduced rainfall in southwestern and northwestern parts of the study area. This study also demonstrated that urbanization significantly reduced latent heat fluxes and albedo of land surface; while increased sensible heat flux changes following urbanization suggested that developed land surfaces mainly acted as heat sources. In this study, climate change projection not only predicts future spatiotemporal patterns of multiple climate factors, but also provides valuable insights into policy making related to land use management, water resource management, and agriculture management to adapt and mitigate future climate changes in this populous region. (C) 2017 Elsevier Ltd. All rights reserved.« less

Landscape analysis of urban growth patterns in Seremban, Malaysia, using spatio-temporal data

NASA Astrophysics Data System (ADS)

Aburas, Maher M.; Abdullah, Sabrina H.; Ramli, Mohammad F.; As'shari, Zulfa H.

2016-06-01

Urban growth is one of the major issues that have played a significant role in destroying the ecosystem in recent years. Landscape analysis is an important technique widely used to evaluate urban growth patterns. In this study, four land-use maps from 1984, 1990, 2000, and 2010 have been used to analyze an urban landscape. The values of a built-up area were initially computed using a geographic information system environment based on the spatial gradient approach. Mathematical matrices were then used to determine the amount of change in urban patches in each direction. Results of the number of patches, landscape shape index, aggregation index, and total edges confirmed that the urban patches in Seremban, Malaysia, have become more dispersed from 2000 to 2010. The urban patches have also become more continuous, especially in the north-western part of Seremban as a result of the urban development in the Nilai District. These results indicate the necessity to create new policies in the city to protect the sustainability of the land use of Seremban.

Impacts of urbanization on the distribution of heavy metals in soils along the Huangpu River, the drinking water source for Shanghai.

PubMed

Bai, Yang; Wang, Min; Peng, Chi; Alatalo, Juha M

2016-03-01

We investigated the horizontal and vertical distribution of heavy metals (Hg, Pb, Zn, Cu, Cd, As, Ni, and Cr) in soils in the water source protection zone for Shanghai to study the origins of these metals, their connections with urbanization, and their potential risk posed on the ecosystem. Determination of metal concentrations in 50 topsoil samples and nine soil profiles indicated that Hg, Pb, Zn, and Cu were present in significantly higher concentrations in topsoil than in deep soil layers. The spatial distributions of Hg, Pb, Zn, and Cu and contamination hotspots for these metals in the study area were similar to those near heavy industries and urban built-up areas. Emissions from automobiles resulted in increased soil concentrations of Cu, Pb, and Zn along roadsides, while high concentrations of Hg in the soil resulted from recent atmospheric deposition. Calculation of the potential ecological risk indicated that the integrative risk of these heavy metals in most areas was low, but a few sites surrounding high density of factories showed moderate risks.

Urban Green Space Dynamics and Distributional Equity in Kumasi, Ghana

NASA Astrophysics Data System (ADS)

Nero, Bertrand

2016-08-01

Urban green spaces (UGS) are crucial for urban sustainability and resilience to environmental vulnerabilities but are often marginalized in cities in the global south. This paper analyzed the spatio-temporal change, extent and distributional inequities associated with UGS in Kumasi, Ghana. Spatial techniques and Gini index were deployed in the assessments.Kumasi UGS cover is currently 33 % but is declining fourfold faster in recent years (2009-2014) than previously (1986-2002). Shannon entropy for built-up sprawl and mean per capita UGS area in 2014 were 0.99 and 25 m2, respectively. Per capita UGS area for 2009 (r2 = 0.50, p=0.049) and 2014 (r2 = 0.53, p=0.0398) were moderately correlated with socioeconomic conditions of submetropolis. The Gini coefficient for both vegetation and tree cover was 0.26.Green space cover in Kumasi is plummeting and somewhat unevenly distributed. Strategic planning for UGS can ensure ample availability, equity in access, and resilience to climate related vulnerabilities.

[Dynamic changes of urban architecture landscape based on Barista: a case study in Tiexi District of Shenyang City].

PubMed

Zhang, Pei-feng; Hu, Yuan-man; He, Hong-shi; Xiong, Zai-ping; Liu, Miao

2010-12-01

In this paper, three-dimensional building information was extracted from high resolution satellite image based on Barista software. Combined with ArcGIS software, the dynamic changes of the building landscape in Tiexi District of Shenyang City during urban renewal process were analyzed from the conversion contribution rate, building density, average building height, and built-up area rate. It was found that during this urban renewal process, four dominant landscape types (vacant lot, residential building, industrial building, and road) were the main parts of the landscape changes. The areas of vacant lot, residential building, commercial building, and road increased, while that of industrial building decreased. The building density decreased, while the average building height increased. There was an obvious regional variation in building landscape. The building density in industrial district was higher than that in residential district, while the average building height was in adverse. The further from the city center, the lower the building density and building average height.

Striving to Reduce Vulnerability:Lessons from the Poor Community Livelihoodsin the Jakarta Bay Facing High Risk of Rapid Urbanization and Climate Changes

NASA Astrophysics Data System (ADS)

Hidayati, D.; Delinom, R. M.; Abdurachim, A. Y.; Dalimunthe, S.; Haba, J.; Pawitan, H.

2014-12-01

This paper discusses water-food issues in relation to how livelihoods of the poor community in Jakarta Bayarein high risk ofrapid urbanization and climate changes. As a part of the capital city of Indonesia, this area has experienced rapid increase in populationand extensive developments causing significant increase in the built up area. This city is unable to keep with demand on sewers, water and solid waste management, leading to settlement with concentrated slum pockets areas and widespread of flooding. The community is mostly poor people of productive group, live with urban pressure in fragile home and livelihoods.The situation becomes much worse due to the impact of climate change with flooding as the greatest climate and disaster risk. With lack of basic services, coastal water inundation (BanjirRob)commonly occursand floods the community housing areaswithout patternanymore. The community has lack of fresh and clean water sources and facedeconomic problem, particularly significant reduction of fishing activities. Coastal reclamation and water pollution from nearby industries are blamed as the main reason for these problems. Strategies therefore have to be developed, especially increasing community awareness and preparedness, and poverty alleviation, to sustain their livelihoods in this high risk urban area.

Built-Up Area Detection from High-Resolution Satellite Images Using Multi-Scale Wavelet Transform and Local Spatial Statistics

NASA Astrophysics Data System (ADS)

Chen, Y.; Zhang, Y.; Gao, J.; Yuan, Y.; Lv, Z.

2018-04-01

Recently, built-up area detection from high-resolution satellite images (HRSI) has attracted increasing attention because HRSI can provide more detailed object information. In this paper, multi-resolution wavelet transform and local spatial autocorrelation statistic are introduced to model the spatial patterns of built-up areas. First, the input image is decomposed into high- and low-frequency subbands by wavelet transform at three levels. Then the high-frequency detail information in three directions (horizontal, vertical and diagonal) are extracted followed by a maximization operation to integrate the information in all directions. Afterward, a cross-scale operation is implemented to fuse different levels of information. Finally, local spatial autocorrelation statistic is introduced to enhance the saliency of built-up features and an adaptive threshold algorithm is used to achieve the detection of built-up areas. Experiments are conducted on ZY-3 and Quickbird panchromatic satellite images, and the results show that the proposed method is very effective for built-up area detection.

Measuring the food and built environments in urban centres: reliability and validity of the EURO-PREVOB Community Questionnaire.

PubMed

Pomerleau, J; Knai, C; Foster, C; Rutter, H; Darmon, N; Derflerova Brazdova, Z; Hadziomeragic, A F; Pekcan, G; Pudule, I; Robertson, A; Brunner, E; Suhrcke, M; Gabrijelcic Blenkus, M; Lhotska, L; Maiani, G; Mistura, L; Lobstein, T; Martin, B W; Elinder, L S; Logstrup, S; Racioppi, F; McKee, M

2013-03-01

The authors designed an instrument to measure objectively aspects of the built and food environments in urban areas, the EURO-PREVOB Community Questionnaire, within the EU-funded project 'Tackling the social and economic determinants of nutrition and physical activity for the prevention of obesity across Europe' (EURO-PREVOB). This paper describes its development, reliability, validity, feasibility and relevance to public health and obesity research. The Community Questionnaire is designed to measure key aspects of the food and built environments in urban areas of varying levels of affluence or deprivation, within different countries. The questionnaire assesses (1) the food environment and (2) the built environment. Pilot tests of the EURO-PREVOB Community Questionnaire were conducted in five to 10 purposively sampled urban areas of different socio-economic status in each of Ankara, Brno, Marseille, Riga, and Sarajevo. Inter-rater reliability was compared between two pairs of fieldworkers in each city centre using three methods: inter-observer agreement (IOA), kappa statistics, and intraclass correlation coefficients (ICCs). Data were collected successfully in all five cities. Overall reliability of the EURO-PREVOB Community Questionnaire was excellent (inter-observer agreement (IOA) > 0.87; intraclass correlation coefficients (ICC)s > 0.91 and kappa statistics > 0.7. However, assessment of certain aspects of the quality of the built environment yielded slightly lower IOA coefficients than the quantitative aspects. The EURO-PREVOB Community Questionnaire was found to be a reliable and practical observational tool for measuring differences in community-level data on environmental factors that can impact on dietary intake and physical activity. The next step is to evaluate its predictive power by collecting behavioural and anthropometric data relevant to obesity and its determinants. Copyright © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

The Effects of the Urban Built Environment on Mental Health: A Cohort Study in a Large Northern Italian City

PubMed Central

Melis, Giulia; Gelormino, Elena; Marra, Giulia; Ferracin, Elisa; Costa, Giuseppe

2015-01-01

Mental health (MH) has a relevant burden on the health of populations. Common MH disorders (anxiety and non-psychotic depression) are well associated to socioeconomic individual and neighborhood characteristics, but little is known about the influence of urban structure. We analyzed among a Turin (Northwest Italy) urban population the association at area level of different urban structure characteristics (density, accessibility by public transport, accessibility to services, green and public spaces) and consumption of antidepressants. Estimates were adjusted by individual socio-demographic variables (education, housing tenure, employment) and contextual social environment (SE) variables (social and physical disorder, crime rates). Data was extracted from the Turin Longitudinal Study (TLS)—a census-based cohort study following up prospectively the mortality and morbidity of the population. As expected, individual characteristics show the strongest association with antidepressant drug consumption, while among built environment (BE) indicators accessibility by public transport and urban density only are associated to MH, being slightly protective factors. Results from this study, in agreement with previous literature, suggest that BE has a stronger effect on MH for people who spend more time in the neighborhood. Therefore, this research suggests that good accessibility to public transport, as well as a dense urban structure (versus sprawl), could contribute to reduced risk of depression, especially for women and elderly, by increasing opportunities to move around and have an active social life. PMID:26610540

CARETS: A prototype regional environmental information system. Volume 2, parts A and B: Norfolk and environs; a land use perspective

NASA Technical Reports Server (NTRS)

Alexander, R. H. (Principal Investigator); Buzzanell, P. J.; Fitzpatrick, K. A.; Lins, H. F., Jr.; Mcginty, H. K., III

1975-01-01

The author has identified the following significant results. The Norfolk-Portsmouth metropolitan statistical area in southeastern Virginia was the site of intensive testing of a number of land resources assessment methods. Land use and land cover data at three levels of detail were derived by manual image interpretation from both aircraft and satellite sources and used to characterize the 1,766 sq km (682 sq mi) area from the perspective of its various resource-related activities and problems. Measurements at level 1 from 1:100, 000 scale maps revealed 42 percent of the test area (excluding bays and estuaries) to be forest, 28 percent agriculture, 23 percent urban and built-up, 4 percent nonforested wetlands, and 2 percent water. At the same scale and level of detail, 10 percent of the area underwent change from one land use category to another in the period 1959-70, 62 percent of which involved the relatively irreversible change from forest or agriculture to urban uses.

Unraveling the impact of built-environmental self-modification of the local inhabitants in their attempt to reduce the urban flood impact in Grogol, Sukoharjo*

NASA Astrophysics Data System (ADS)

Wanabakti, M. J.; Susilo, C. R.; Nathania, M.; Putri, C. Y.

2018-05-01

Due in part to climate change impact and the lack of environmental awareness of urban societies, urban flood disasters have increased in both frequency and impacted areas. The inevitable destructive impact is also experienced by urban inhabitants within Grogol District, Sukoharjo, Central Java. Situated within the fast-growing peri-urban area of Surakarta, the geographical condition of the district, which is located in the convergence of Bengawan Solo River and four different streamlet rivers is undoubtedly critical to flood. Since the position of the peri-urban area is along the border of Surakarta City and Sukoharjo Regency, the site is a strategic locus of the main city’s urban expansion. However, its border location has made flood-reduction programs challenging to be implemented, due to unclear territorial admiration and distribution. Because of the absence of flood-reduction programs in the area, local inhabitants have been independently developing physical and built environmental modification of their settlements. By analyzing the two-months built environmental fieldwork research in Grogol Sukoharjo, this paper unravels both the success and the conflicting impact of local self-initiative modification in Grogol Sukoharjo. By combining the two-month field observation with the semi-structured interviews in three sub-districts of Grogol, this paper finds that the very pragmatic self-modification taken by the inhabitants results in short-term reductions of flood impact and increases the secure feelings of inhabitants to continue living in their neighborhoods. However, the lack of proper technical supervision from experts and the absence of inter-neighborhood coordination leads to future additional damage on the flood-prone areas of Grogol. The paper also reveals that one pragmatic physical self-modification solution taken by one neighborhood may lead to an extra flood-threat to other neighborhoods.

The spatial-temporal patterns and the driving forces of land-use/cover change in the Dongting Lake area of the middle Yangtze River basin

NASA Astrophysics Data System (ADS)

Li, Rendong; Liu, Jiyuan; Zhuang, Dafang; Gao, Zhiqiang

2004-11-01

Dongting Lake area, located on the southern bank of the middle Yangtze River in central China, is one of the regions experiencing rapid land use change and seriously suffering from flooding disaster in the country. In this paper, a series of land-use coverage was generated through visually interpreting Landsat MSS, TM and ETM images, of 1980, 1990 and 2000 respectively. Then, the spatial-temporal characteristics and the driving forces of the land use changes were analyzed in the study area. The results show that, from 1980 to 2000, the areas of farmland, woodland and non-used land decreased, while those of built-up land, water area and grassland increased. There was a significant shifting from farmland to water or built-up area, and the large-scale reclamation from the lake ever in history has not been found since 1980. The fastest changed area was in Shishou City, Yueyang City and Jinshi City, and the slowest in the eastern and southeastern area. About 49% of the changes were caused by the adjustment of agricultural economic structure, 29.75% by the urbanization and industrialization, and 21.41% by the environmental pressure. The policy, market price and tax on land products also have definitively influences on the land-use changes.

Urban structure and dengue fever in Puntarenas, Costa Rica

PubMed Central

Troyo, Adriana; Fuller, Douglas O.; Calderón-Arguedas, Olger; Solano, Mayra E.; Beier, John C.

2009-01-01

Dengue is currently the most important arboviral disease globally and is usually associated with built environments in tropical areas. Remotely sensed information can facilitate the study of urban mosquito-borne diseases by providing multiple temporal and spatial resolutions appropriate to investigate urban structure and ecological characteristics associated with infectious disease. In this study, coarse, medium and fine resolution satellite imagery (Moderate Resolution Imaging Spectrometer, Advanced Spaceborne Thermal Emission and Reflection Radiometer and QuickBird respectively) and ground-based data were analyzed for the Greater Puntarenas area, Costa Rica for the years 2002–04. The results showed that the mean normalized difference vegetation index (NDVI) was generally higher in the localities with lower incidence of dengue fever during 2002, although the correlation was statistically significant only in the dry season (r=−0.40; p=0.03). Dengue incidence was inversely correlated to built area and directly correlated with tree cover (r=0.75, p=0.01). Overall, the significant correlations between dengue incidence and urban structural variables (tree cover and building density) suggest that properties of urban structure may be associated with dengue incidence in tropical urban settings. PMID:20161131

The Relationship between Habitat Loss and Fragmentation during Urbanization: An Empirical Evaluation from 16 World Cities.

PubMed

Liu, Zhifeng; He, Chunyang; Wu, Jianguo

2016-01-01

Urbanization results in habitat loss and habitat fragmentation concurrently, both influencing biodiversity and ecological processes. To evaluate these impacts, it is important to understand the relationships between habitat loss and habitat fragmentation per se (HLHF) during urbanization. The objectives of this study were two-fold: 1) to quantify the different forms of the HLHF relationship during urbanization using multiple landscape metrics, and 2) to test the validity of the HLHF relations reported in the literature. Our analysis was based on a long-term urbanization dataset (1800-2000) of 16 large cities from around the world. Habitat area was represented as the percentage of non-built-up area in the landscape, while habitat fragmentation was measured using several landscape metrics. Our results show that the relationship between habitat loss and habitat fragmentation during urbanization is commonly monotonic-linear, exponential, or logarithmic, indicating that the degree of habitat fragmentation per se increases with habitat loss in general. We compared our results with 14 hypothesized HLHF relationships based on simulated landscapes found in the literature, and found that four of them were consistent with those of urbanization, whereas the other ten were not. Also, we identified six new HLHF relationships when fragmentation was measured by total core area, normalized total core area, patch density, edge density and landscape shape index, respectively. In addition, our study demonstrated that the "space-for-time" approach, frequently used in ecology and geography, generated specious HLHF relationships, suggesting that this approach is largely inappropriate for analyses of urban landscapes that are highly heterogeneous in space and unusually contingent in dynamics. Our results show both generalities and idiosyncrasies of the HLHF relationship, providing new insights for assessing ecological effects of urbanization.

The Relationship between Habitat Loss and Fragmentation during Urbanization: An Empirical Evaluation from 16 World Cities

PubMed Central

He, Chunyang

2016-01-01

Urbanization results in habitat loss and habitat fragmentation concurrently, both influencing biodiversity and ecological processes. To evaluate these impacts, it is important to understand the relationships between habitat loss and habitat fragmentation per se (HLHF) during urbanization. The objectives of this study were two-fold: 1) to quantify the different forms of the HLHF relationship during urbanization using multiple landscape metrics, and 2) to test the validity of the HLHF relations reported in the literature. Our analysis was based on a long-term urbanization dataset (1800–2000) of 16 large cities from around the world. Habitat area was represented as the percentage of non-built-up area in the landscape, while habitat fragmentation was measured using several landscape metrics. Our results show that the relationship between habitat loss and habitat fragmentation during urbanization is commonly monotonic—linear, exponential, or logarithmic, indicating that the degree of habitat fragmentation per se increases with habitat loss in general. We compared our results with 14 hypothesized HLHF relationships based on simulated landscapes found in the literature, and found that four of them were consistent with those of urbanization, whereas the other ten were not. Also, we identified six new HLHF relationships when fragmentation was measured by total core area, normalized total core area, patch density, edge density and landscape shape index, respectively. In addition, our study demonstrated that the “space-for-time” approach, frequently used in ecology and geography, generated specious HLHF relationships, suggesting that this approach is largely inappropriate for analyses of urban landscapes that are highly heterogeneous in space and unusually contingent in dynamics. Our results show both generalities and idiosyncrasies of the HLHF relationship, providing new insights for assessing ecological effects of urbanization. PMID:27124180

Quantifying urban growth patterns in Hanoi using landscape expansion modes and time series spatial metrics.

PubMed

Nong, Duong H; Lepczyk, Christopher A; Miura, Tomoaki; Fox, Jefferson M

2018-01-01

Urbanization has been driven by various social, economic, and political factors around the world for centuries. Because urbanization continues unabated in many places, it is crucial to understand patterns of urbanization and their potential ecological and environmental impacts. Given this need, the objectives of our study were to quantify urban growth rates, growth modes, and resultant changes in the landscape pattern of urbanization in Hanoi, Vietnam from 1993 to 2010 and to evaluate the extent to which the process of urban growth in Hanoi conformed to the diffusion-coalescence theory. We analyzed the spatiotemporal patterns and dynamics of the built-up land in Hanoi using landscape expansion modes, spatial metrics, and a gradient approach. Urbanization was most pronounced in the periods of 2001-2006 and 2006-2010 at a distance of 10 to 35 km around the urban center. Over the 17 year period urban expansion in Hanoi was dominated by infilling and edge expansion growth modes. Our findings support the diffusion-coalescence theory of urbanization. The shift of the urban growth areas over time and the dynamic nature of the spatial metrics revealed important information about our understanding of the urban growth process and cycle. Furthermore, our findings can be used to evaluate urban planning policies and aid in urbanization issues in rapidly urbanizing countries.

Changing landscape in the Three Gorges Reservoir Area of Yangtze River from 1977 to 2005: Land use/land cover, vegetation cover changes estimated using multi-source satellite data

NASA Astrophysics Data System (ADS)

Zhang, Jixian; Zhengjun, Liu; Xiaoxia, Sun

2009-12-01

The eco-environment in the Three Gorges Reservoir Area (TGRA) in China has received much attention due to the construction of the Three Gorges Hydropower Station. Land use/land cover changes (LUCC) are a major cause of ecological environmental changes. In this paper, the spatial landscape dynamics from 1978 to 2005 in this area are monitored and recent changes are analyzed, using the Landsat TM (MSS) images of 1978, 1988, 1995, 2000 and 2005. Vegetation cover fractions for a vegetation cover analysis are retrieved from MODIS/Terra imagery from 2000 to 2006, being the period before and after the rising water level of the reservoir. Several analytical indices have been used to analyze spatial and temporal changes. Results indicate that cropland, woodland, and grassland areas reduced continuously over the past 30 years, while river and built-up area increased by 2.79% and 4.45% from 2000 to 2005, respectively. The built-up area increased at the cost of decreased cropland, woodland and grassland. The vegetation cover fraction increased slightly. We conclude that significant changes in land use/land cover have occurred in the Three Gorges Reservoir Area. The main cause is a continuous economic and urban/rural development, followed by environmental management policies after construction of the Three Gorges Dam.

Adverse Impact of Electromagnetic Radiation on Urban Environment and Natural Resources using Optical Sensors

NASA Astrophysics Data System (ADS)

Kumar, Pawan; Katiyar, Swati; Rani, Meenu

2016-07-01

We are living in the age of a rapidly growing population and changing environmental conditions with an advance technical capacity.This has resulted in wide spread land cover change. One of the main causes for increasing urban heat is that more than half of the world's population lives in a rapidly growing urbanized environment. Satellite data can be highly useful to map change in land cover and other environmental phenomena with the passage of time. Among several human-induced environmental and urban thermal problems are reported to be negatively affecting urban residents in many ways. The built-up structures in urbanized areas considerably alter land cover thereby affecting thermal energy flow which leads to development of elevated surface and air temperature. The phenomenon Urban Heat Island implies 'island' of high temperature in cities, surrounded by relatively lower temperature in rural areas. The UHI for the temporal period is estimated using geospatial techniques which are then utilized for the impact assessment on climate of the surrounding regions and how it reduce the sustainability of the natural resources like air, vegetation. The present paper describes the methodology and resolution dynamic urban heat island change on climate using the geospatial approach. NDVI were generated using day time LANDSAT ETM+ image of 1990, 2000 and 2013. Temperature of various land use and land cover categories was estimated. Keywords: NDVI, Surface temperature, Dynamic changes.

Analysis of the role of urban vegetation in local climate of Budapest using satellite measurements

NASA Astrophysics Data System (ADS)

Pongracz, Rita; Bartholy, Judit; Dezso, Zsuzsanna; Fricke, Cathy

2016-08-01

Urban areas significantly modify the natural environment due to the concentrated presence of humans and the associated anthropogenic activities. In order to assess this effect, it is essential to evaluate the relationship between urban and vegetated surface covers. In our study we focused on the Hungarian capital, Budapest, in which about 1.7 million inhabitants are living nowadays. The entire city is divided by the river Danube into the hilly, greener Buda side on the west, and the flat, more densely built-up Pest side on the east. Most of the extended urban vegetation, i.e., forests are located in the western Buda side. The effects of the past changing of these green areas are analyzed using surface temperature data calculated from satellite measurements in the infrared channels, and NDVI (Normalized Difference Vegetation Index) derived from visible and near-infrared satellite measurements. For this purpose, data available from sensor MODIS (Moderate Resolution Imaging Spectroradiometer) of NASA satellites (i.e., Terra and Aqua) are used. First, the climatological effects of forests on the urban heat island intensity are evaluated. Then, we also aim to evaluate the relationship of surface temperature and NDVI in this urban environment with special focus on vegetation-related sections of the city where the vegetation cover either increased or decreased remarkably.

Sustainability of Smart Cities under Climate Variability and Climate Change in India

NASA Astrophysics Data System (ADS)

Kumar, R.; Mishra, V.

2015-12-01

India has experienced a rapid urbanization during the past few decades. On the other hand, many parts of the country witnessed significant changes in mean and extreme climate related to precipitation and temperature. Here we analysed urban residence using the remotely sensed data considering the susceptibility of Indian cities to droughts and heat waves. We selected recently announced 100 urban areas that are planned to be developed as smart cities in future. Gridded precipitation data were used to compute SPEI values for frequency and ascertain the extent of droughts in the cities. The heat wave analysis was done in two phases. First phase included analysis using Heat Wave Magnitude Index (HWMI) to determine the intensity of such extreme events. In the second phase, Urban Heat Island (UHI) effect across different ecological configuration was studied for the cities. Land Surface Temperature (LST), urban extent map from MODIS and land-cover maps were used to study the UHI effect. For this, the urban extents were divided into urban core and sub-urban zones based on built up regions in the cities. The urban to rural temperature difference is analysed considering the ecological configuration in the region. The selected cities were categorised based on the biome features surrounding them. The results suggest aggravated condition in the urban space in India with reference to extreme events. For instance, extreme heat waves have substantially increased in India during the last few decades. In many urban areas, the UHI effect contributed a significant warming due to increased urbanization. We estimated projected changes in droughts and heat waves in the selected urban areas using the dynamically downscaled data from the region climate models. Our results suggest that a majority of urban areas are projected to face an elevated risk of temperature related extremes and issues of water sustainability in the coming decades.

Assessment of land use and land cover change using spatiotemporal analysis of landscape: case study in south of Tehran.

PubMed

Sabr, Abutaleb; Moeinaddini, Mazaher; Azarnivand, Hossein; Guinot, Benjamin

2016-12-01

In the recent years, dust storms originating from local abandoned agricultural lands have increasingly impacted Tehran and Karaj air quality. Designing and implementing mitigation plans are necessary to study land use/land cover change (LUCC). Land use/cover classification is particularly relevant in arid areas. This study aimed to map land use/cover by pixel- and object-based image classification methods, analyse landscape fragmentation and determine the effects of two different classification methods on landscape metrics. The same sets of ground data were used for both classification methods. Because accuracy of classification plays a key role in better understanding LUCC, both methods were employed. Land use/cover maps of the southwest area of Tehran city for the years 1985, 2000 and 2014 were obtained from Landsat digital images and classified into three categories: built-up, agricultural and barren lands. The results of our LUCC analysis showed that the most important changes in built-up agricultural land categories were observed in zone B (Shahriar, Robat Karim and Eslamshahr) between 1985 and 2014. The landscape metrics obtained for all categories pictured high landscape fragmentation in the study area. Despite no significant difference was evidenced between the two classification methods, the object-based classification led to an overall higher accuracy than using the pixel-based classification. In particular, the accuracy of the built-up category showed a marked increase. In addition, both methods showed similar trends in fragmentation metrics. One of the reasons is that the object-based classification is able to identify buildings, impervious surface and roads in dense urban areas, which produced more accurate maps.

Old river beds under urbanization pressure. Can we protect valuable aquatic ecosystems within the cities?

NASA Astrophysics Data System (ADS)

Sikorska, Daria; Sikorski, Piotr

2016-04-01

Old river channels are valuable ecosystems in the scale of whole Europe. Protected as Natura 2000 habitats they are characterized by high biodiversity and provide various ecosystem services. River regulation, eutrophication or lack of annual flooding result in an impoverishment and disappearance of these habitats. Moreover they are subjected to severe pressure from uncontrolled expansion of the cities. The aim of this study was to determine factors associated with urbanization mostly contributing to impoverishment of the vegetation associated with the old channels and to identify landscape characteristics favouring high diversity and naturalness. We were seeking for indices that could be implemented in spatial management for preservation of these ecosystems. Vegetation inventory of 28 lakes, being former river Vistula beds near Warsaw was held. The lakes were located in an urban-rural gradient from the city centre, suburban zone to rural areas. Mapping of vegetation was performed for aquatic vegetation, rushes and vegetation of the shores (321 relevés). Human pressure was assessed on the basis of landscape composition of the lakes neighbourhood, characteristic features of the reservoir and water physio-chemical properties. High diversity and naturalness of the vegetation associated with former Vistula River beds was proved. Effects of the human pressure in the vegetation composition were recognized in high share of alien species and impoverishment of native plants. Composition was dependant on the intensity of human pressure in the neighbourhood and was mostly related to percentage of built-up areas and road density. Selected measures allowed to explain not more than 30% of plants composition variation which implies strong effect of local factors. Vegetation composition of former river beds changed significantly along urban-rural gradient, though the trend could be noted only to the city border. Several protection activities were proposed favouring high biodiversity and naturalness of the vegetation, especially for the suburban zone where the lakes were characterized by high diversity but also subjected to highest pressure from increasing percentage of built-up areas in the neighbourhood.

Statistical modeling of urban air temperature distributions under different synoptic conditions

NASA Astrophysics Data System (ADS)

Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Hald, Cornelius; Hartz, Uwe; Jacobeit, Jucundus; Richter, Katja; Schneider, Alexandra; Wolf, Kathrin

2015-04-01

Within urban areas air temperature may vary distinctly between different locations. These intra-urban air temperature variations partly reach magnitudes that are relevant with respect to human thermal comfort. Therefore and furthermore taking into account potential interrelations with other health related environmental factors (e.g. air quality) it is important to estimate spatial patterns of intra-urban air temperature distributions that may be incorporated into urban planning processes. In this contribution we present an approach to estimate spatial temperature distributions in the urban area of Augsburg (Germany) by means of statistical modeling. At 36 locations in the urban area of Augsburg air temperatures are measured with high temporal resolution (4 min.) since December 2012. These 36 locations represent different typical urban land use characteristics in terms of varying percentage coverages of different land cover categories (e.g. impervious, built-up, vegetated). Percentage coverages of these land cover categories have been extracted from different sources (Open Street Map, European Urban Atlas, Urban Morphological Zones) for regular grids of varying size (50, 100, 200 meter horizonal resolution) for the urban area of Augsburg. It is well known from numerous studies that land use characteristics have a distinct influence on air temperature and as well other climatic variables at a certain location. Therefore air temperatures at the 36 locations are modeled utilizing land use characteristics (percentage coverages of land cover categories) as predictor variables in Stepwise Multiple Regression models and in Random Forest based model approaches. After model evaluation via cross-validation appropriate statistical models are applied to gridded land use data to derive spatial urban air temperature distributions. Varying models are tested and applied for different seasons and times of the day and also for different synoptic conditions (e.g. clear and calm situations, cloudy and windy situations). Based on hourly air temperature data from our measurements in the urban area of Augsburg distinct temperature differences between locations with different urban land use characteristics are revealed. Under clear and calm weather conditions differences between mean hourly air temperatures reach values around 8°C. Whereas during cloudy and windy weather maximum differences in mean hourly air temperatures do not exceed 5°C. Differences appear usually slightly more pronounced in summer than in winter. First results from the application of statistical modeling approaches reveal promising skill of the models in terms of explained variances reaching up to 60% in leave-one-out cross-validation experiments. The contribution depicts the methodology of our approach and presents and discusses first results.

Reconstruction of Building Outlines in Dense Urban Areas Based on LIDAR Data and Address Points

NASA Astrophysics Data System (ADS)

Jarzabek-Rychard, M.

2012-07-01

The paper presents a comprehensive method for automated extraction and delineation of building outlines in densely built-up areas. A novel approach to outline reconstruction is the use of geocoded building address points. They give information about building location thus highly reduce task complexity. Reconstruction process is executed on 3D point clouds acquired by airborne laser scanner. The method consists of three steps: building detection, delineation and contours refinement. The algorithm is tested against a data set that presents the old market town and its surroundings. The results are discussed and evaluated by comparison to reference cadastral data.

Central atlantic regional ecological test site: A prototype regional environmental information system, volume 1. [Pennsylvania, Delaware, Maryland, Virginia, and the District of Columbia

NASA Technical Reports Server (NTRS)

Alexander, R. H. (Principal Investigator)

1979-01-01

The author has identified the following significant results. LANDSAT data showed the test region in 1972 to be 9% urban and built-up land, 38% agriculture, 50% forest, 3% nonforested wetlands, and less than 1% barren land, exclusive of water-covered areas. A comprehensive user evaluation revealed greatest demand for high-altitude aerial photography and the detailed maps and data products that can be derived from the metropolitan areas agencies, found relatively little use for LANDSAT imagery at 1:250,000 scale and corresponding manually interpreted land use maps.

Hybrid method for building extraction in vegetation-rich urban areas from very high-resolution satellite imagery

NASA Astrophysics Data System (ADS)

Jayasekare, Ajith S.; Wickramasuriya, Rohan; Namazi-Rad, Mohammad-Reza; Perez, Pascal; Singh, Gaurav

2017-07-01

A continuous update of building information is necessary in today's urban planning. Digital images acquired by remote sensing platforms at appropriate spatial and temporal resolutions provide an excellent data source to achieve this. In particular, high-resolution satellite images are often used to retrieve objects such as rooftops using feature extraction. However, high-resolution images acquired over built-up areas are associated with noises such as shadows that reduce the accuracy of feature extraction. Feature extraction heavily relies on the reflectance purity of objects, which is difficult to perfect in complex urban landscapes. An attempt was made to increase the reflectance purity of building rooftops affected by shadows. In addition to the multispectral (MS) image, derivatives thereof namely, normalized difference vegetation index and principle component (PC) images were incorporated in generating the probability image. This hybrid probability image generation ensured that the effect of shadows on rooftop extraction, particularly on light-colored roofs, is largely eliminated. The PC image was also used for image segmentation, which further increased the accuracy compared to segmentation performed on an MS image. Results show that the presented method can achieve higher rooftop extraction accuracy (70.4%) in vegetation-rich urban areas compared to traditional methods.

Spatial heterogeneity and temporal evolution of malaria transmission risk in Dakar, Senegal, according to remotely sensed environmental data

PubMed Central

2010-01-01

Background The United Nations forecasts that by 2050, more than 60% of the African population will live in cities. Thus, urban malaria is considered an important emerging health problem in that continent. Remote sensing (RS) and geographic information systems (GIS) are useful tools for addressing the challenge of assessing, understanding and spatially focusing malaria control activities. The objectives of the present study were to use high spatial resolution SPOT (Satellite Pour l'Observation de la Terre) satellite images to identify some urban environmental factors in Dakar associated with Anopheles arabiensis densities, to assess the persistence of these associations and to describe spatial changes in at-risk environments using a decadal time scale. Methods Two SPOT images from the 1996 and 2007 rainy seasons in Dakar were processed to extract environmental factors, using supervised classification of land use and land cover, and a calculation of NDVI (Normalized Difference Vegetation Index) and distance to vegetation. Linear regressions were fitted to identify the ecological factors associated with An. arabiensis aggressiveness measured in 1994-97 in the South and centre districts of Dakar. Risk maps for populated areas were computed and compared for 1996 and 2007 using the results of the statistical models. Results Almost 60% of the variability in anopheline aggressiveness measured in 1994-97 was explained with only one variable: the built-up area in a 300-m radius buffer around the catching points. This association remained stable between 1996 and 2007. Risk maps were drawn by inverting the statistical association. The total increase of the built-up areas in Dakar was about 30% between 1996 and 2007. In proportion to the total population of the city, the population at high risk for malaria fell from 32% to 20%, whereas the low-risk population rose from 29 to 41%. Conclusions Environmental data retrieved from high spatial resolution SPOT satellite images were associated with An. arabiensis densities in Dakar urban setting, which allowed to generate malaria transmission risk maps. The evolution of the risk was quantified, and the results indicated there are benefits of urbanization in Dakar, since the proportion of the low risk population increased while urbanization progressed. PMID:20815867

Spatiotemporal Built-up Land Density Mapping Using Various Spectral Indices in Landsat-7 ETM+ and Landsat-8 OLI/TIRS (Case Study: Surakarta City)

NASA Astrophysics Data System (ADS)

Risky, Yanuar S.; Aulia, Yogi H.; Widayani, Prima

2017-12-01

Spectral indices variations support for rapid and accurate extracting information such as built-up density. However, the exact determination of spectral waves for built-up density extraction is lacking. This study explains and compares the capabilities of 5 variations of spectral indices in spatiotemporal built-up density mapping using Landsat-7 ETM+ and Landsat-8 OLI/TIRS in Surakarta City on 2002 and 2015. The spectral indices variations used are 3 mid-infrared (MIR) based indices such as the Normalized Difference Built-up Index (NDBI), Urban Index (UI) and Built-up and 2 visible based indices such as VrNIR-BI (visible red) and VgNIR-BI (visible green). Linear regression statistics between ground value samples from Google Earth image in 2002 and 2015 and spectral indices for determining built-up land density. Ground value used amounted to 27 samples for model and 7 samples for accuracy test. The classification of built-up density mapping is divided into 9 classes: unclassified, 0-12.5%, 12.5-25%, 25-37.5%, 37.5-50%, 50-62.5%, 62.5-75%, 75-87.5% and 87.5-100 %. Accuracy of built-up land density mapping in 2002 and 2015 using VrNIR-BI (81,823% and 73.235%), VgNIR-BI (78.934% and 69.028%), NDBI (34.870% and 74.365%), UI (43.273% and 64.398%) and Built-up (59.755% and 72.664%). Based all spectral indices, Surakarta City on 2000-2015 has increased of built-up land density. VgNIR-BI has better capabilities for built-up land density mapping on Landsat-7 ETM + and Landsat-8 OLI/TIRS.

Impact of greenspaces in city on avian species richness and abundance in Northern Africa.

PubMed

Aouissi, Hani Amir; Gasparini, Julien; Belabed, Adnène Ibrahim; Bouslama, Zihad

2017-08-01

Increasing urbanization is a major challenge in the context of global changes, because this environment is known to negatively impact biodiversity. It is therefore important to identify factors maintaining biodiversity in such areas. Here, we tested in 650 sites whether the greenspaces in urbanized area of Annaba (Algeria) has positive effects on avian species richness and abundances. Our results show that species detection (n=26) is more important during the breeding season as compared to the winter season, and that avian species richness is positively affected by the greenspaces. For most species, greenspaces impact positively their presence and abundances. Only the feral pigeon was less detected in greenspaces as compared to built-up areas. Our study therefore confirmed, for the first time in a Northern African city, that greenspaces significantly increase the species richness and abundances of birds, and shows that the season can profoundly affect such indicators. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Accessibility and independent mobility in rural built environments : challenges and opportunities for young people.

DOT National Transportation Integrated Search

2013-03-01

Much of the research on accessibility and the built environment performed to date have been : conducted in urban settings and most have focused on adults. Few studies addressing this topic : have concerned areas with low population density and fewer ...

Urban heat island in Krakow, Poland: Land use versus land form interaction

NASA Astrophysics Data System (ADS)

Bokwa, A.

2012-04-01

Urban heat island is a well known feature of urban climate, related mainly to the changes in land use in urban areas and anthropogenic heat emission. However, the interaction between the land use and land form in urban areas and its impact on air temperature spatial patterns is much less known. Krakow is a medium size city located in southern Poland, in the valley of the Vistula River. The city is surrounded with convex land forms from three sides, with height differences up to 100 m. Built-up areas of the city can be found in both the valley bottom and on nearby slopes. Numerous studies completed after the Second World War (e.g. Hess 1974, Lewinska et al. 1982, Morawska-Horawska, Cebulak 1981) showed that the characteristic features of the climate of Krakow are e.g. frequent air temperature inversions, poor natural ventilation, large precipitation horizontal gradients. More recent research (e.g. Bokwa 2010) revealed e.g. a thermal asymmetry of the area. On the basis of 3-year (2009-2011) air temperature measurements in 21 points, completed with mobile measurements and analysis of available long-term series, it was proposed to define urban heat island separately in particular vertical zones of the city. Bokwa, A., 2010, Wieloletnie zmiany struktury mezoklimatu miasta na przykladzie Krakowa [Multi-annual changes of the urban mesoclimate structure (using an example of Kraków)], Institute of Geography and Spatial Management, Jagiellonian University, Kraków, 258 pp.; available on-line: http://www.geo.uj.edu.pl/publikacje.php?&lang=1&page=monografie&menu=3&id=000155 Hess M., 1974, Klimat Krakowa {Climate of Krakow], Folia Geogr., ser. Geogr.-Phys., 8, 45-102. Lewińska J., Bartosik J., Baścik J., Czerwieniec M., Zgud K., 1982, Wpływ miasta na klimat lokalny (na przykładzie aglomeracji krakowskiej) [Impact of a city on the local climate using an example of Krakow], Inst. Kształt. Środ., Warszawa. Morawska-Horawska M., Cebulak E., 1981, Badania pionowego zasięgu miejskiej wyspy ciepła nad Krakowem [Studies on vertical extent of urban heat island over Krakow], Folia Geogr., ser. Geogr.-Phys., 14, 43-50.

Using the LCZ framework for change detection and urban growth monitoring

NASA Astrophysics Data System (ADS)

Danylo, Olha; See, Linda; Gomez, Adriana; Schnabel, Georg; Fritz, Steffen

2017-04-01

The world's population reached 7.3 billion in 2015 and it is projected to increase further to 9.7 billion by 2050. Population growth is strongly linked to city expansion, as many people are moving from rural to urban areas. In order to enhance inclusive and sustainable urbanization, we need an efficient workflow for assessing the corresponding SDG (Sustainable Development Goal) targets. In this study we investigate how the Local Climate Zone (LCZ) classification framework can be used for monitoring sustainable urbanization and assess the availability of adequate and safe housing. The original LCZ classification system consists of 10 urban classes, which can be characterized by urban structure, the type of roads and buildings, the density of the built-up area, etc. The other seven classes in the classification scheme include natural land cover classes that do not contain any buildings (e.g., forest, low vegetation, bare land, water, etc). As a case study area we have chosen the cities of Johannesburg and Pretoria in South Africa. According to the 2011 Census, the population of Gauteng province (which includes both Johannesburg and Pretoria) increased by 32.55% compared to 2001 Census and reached 12 million in 2011. A large number of people live in slums and informal housing, which makes this area relevant for such an analysis. Using available satellite images for different years, we classified the case-study areas into the main LCZ classes, including the lightweight lowrise building zone, which corresponds to informal housing. We estimated the land use efficiency as the ratio of the land consumption rate to the population growth rate to illustrate how the LCZ framework can be applied to the assessment of urban growth and to help understand the trajectories of the changes in the urban environment. We show that a low value of this ratio does not necessarily indicate sustainable city expansion, but may instead signal a growing population density in the slum areas.

Mapping the Urban Side of the Earth- the new GUF+ Layer

NASA Astrophysics Data System (ADS)

Gorelick, N.; Marconcini, M.; Üreyen, S.; Zeidler, J.; Svaton, V.; Esch, T.

2017-12-01

From the beginning of the years 2000, it is estimated that more than half of the global population is living in cities and the dynamic trend of urbanization is growing at an unprecedented speed. In such framework, how does expanding population affect the surrounding landscape? Are urban areas making good use of limited space or is rapid urbanization threatening the planet's sustainability? What is the impact of urbanization on vulnerability to natural disasters? To try answering these and other challenging questions, a key information is to reliably know the location and characteristics (e.g. shape, extent, greenness) of human settlements worldwide. In this context, yet from the last decade different global maps outlining urban areas have started being produced. Here, DLR's Global Urban Footprint (GUF) layer, generated on the basis of very high resolution radar imagery, represents one of the most accurate and largely employed datasets. However, in order to overcome still existing limitations of the GUF layer, often originating from specifics of the underlying radar imagery, DLR developed a novel methodology that for the first time exploits mass multitemporal collections of optical and radar satellite imagery. The new approach has been employed for generating the GUF+ 2015 layer, a global map of settlement areas derived at 10m spatial resolution based overall on a joint analysis of hundreds of thousands of Landsat and Sentinel-1 scenes (processed with the support of Google Earth Engine) collected in the years 2014-2015. The GUF+2015 outperforms all other existing global human settlements maps and allows - among others - to considerably improve the detection of very small settlements in rural regions and better outline scattered peri-urban areas. Nevertheless, this is not an arrival but rather a starting point for generating a suite of additional products (GUF+ suite) supposed to support a 360° analysis of global urbanization - e.g. with data on the imperviousness/greenness and the spatiotemporal development of the built-up area over the last decades.

Are Remotely Sensed Trends in the Built Environment and Urban Vegetation Predictive of Changes in Metropolitan Housing Markets?

NASA Astrophysics Data System (ADS)

Endsley, K. A.

2017-12-01

In the midst of a global urbanization trend, residential neighborhoods are undergoing a variety of changes, including neighborhood turnover, the re-location of employment centers, and, recently, the increasing social and economic isolation of the suburbs. In the U.S., where residential lawns account for more area than any other irrigated crop (Polsky et al. 2014, in PNAS), coeval changes in residential populations, the built environment, and vegetation have serious implications for urban sustainability. To date, detailed studies of dynamic neighborhood changes have been hampered by the lack of fine time-series data on neighborhood composition. Most notably, the U.S. Census is conducted only once every decade leading to the likely inaccurate assumption of linear change between Census years. To the extent that human activities alter the built environment and urban ecology, can remotely sensed biophysical changes serve as a good proxy for neighborhood socio-economic changes? In this study, I apply time series data on spectral reflectance, spectral indices, and land-cover abundances from 15-to-25 years of Landsat data to fine-scale data on residential property transactions in two metropolitan areas with different regional economic and environmental contexts: Detroit and Los Angeles. The real estate record provides parcel-level, monthly data on sale prices and tax foreclosures; taken together, these provide a good description of the housing market and an acceptable proxy for neighborhood stability. By comparing lagged features from the remote sensing (RS) archive at different time scales in a non-parametric statistical learning algorithm, I identify which RS features best predict changes in the housing market and compare these associations between the two metropolitan areas and across multiple spatial and temporal scales along an urban to peri-urban gradient.

Urban Development from the Perspective of Geodivesity in South Korea

NASA Astrophysics Data System (ADS)

Mo, Y.; Lee, D. K.; Han Kyul, H.

2015-12-01

In regard to ensuring a sustainable Earth, geodiversity (which is the variety of non-living nature) has been recognized as being equivalent to biodiversity in terms of importance. Geodiversity, as a platform, provides diverse habitats; however when a city is developed, threatened and vulnerable species are seen as important components of conservation but geodiversity is not. This study analyzes the components of geodiversity in cities that developed rapidly, and identifies which characteristics of geodiversity were related to this development. We estimated the components of geodiversity through the use of land cover maps and digital elevation maps (DEMs) in South Korean cities that developed rapidly between the 1980s and early-2010s, such as Yong-in and Namyangju. The relationships between land use changes and geodiversity components were analyzed and a factor analysis for land use changes was conducted using geodiversity components. Results show that even though adjacent rivers and streams, low elevation, and flat surfaces have high geodiversity, these areas were mainly converted into built-up areas and agricultural areas. As such, it can be stated that urban development in these cities has lowered geodiversity. Other geodiversity components related to urban development, such as slope, upslope contributing areas, streams, and lithology, were also identified. To conclude, this study showed how geodiversity components related to urban development has been affected by this growth and how they are intimately connected to each other. Identifying geodiversity in future development sites could help to estimate the most sensitive areas regarding the planned development; therefore, we need to view urban development from a geodiversity perspective.

Insights to urban dynamics through landscape spatial pattern analysis

NASA Astrophysics Data System (ADS)

TV, Ramachandra; Aithal, Bharath H.; Sanna, Durgappa D.

2012-08-01

Urbanisation is a dynamic complex phenomenon involving large scale changes in the land uses at local levels. Analyses of changes in land uses in urban environments provide a historical perspective of land use and give an opportunity to assess the spatial patterns, correlation, trends, rate and impacts of the change, which would help in better regional planning and good governance of the region. Main objective of this research is to quantify the urban dynamics using temporal remote sensing data with the help of well-established landscape metrics. Bangalore being one of the rapidly urbanising landscapes in India has been chosen for this investigation. Complex process of urban sprawl was modelled using spatio temporal analysis. Land use analyses show 584% growth in built-up area during the last four decades with the decline of vegetation by 66% and water bodies by 74%. Analyses of the temporal data reveals an increase in urban built up area of 342.83% (during 1973-1992), 129.56% (during 1992-1999), 106.7% (1999-2002), 114.51% (2002-2006) and 126.19% from 2006 to 2010. The Study area was divided into four zones and each zone is further divided into 17 concentric circles of 1 km incrementing radius to understand the patterns and extent of the urbanisation at local levels. The urban density gradient illustrates radial pattern of urbanisation for the period 1973-2010. Bangalore grew radially from 1973 to 2010 indicating that the urbanisation is intensifying from the central core and has reached the periphery of the Greater Bangalore. Shannon's entropy, alpha and beta population densities were computed to understand the level of urbanisation at local levels. Shannon's entropy values of recent time confirms dispersed haphazard urban growth in the city, particularly in the outskirts of the city. This also illustrates the extent of influence of drivers of urbanisation in various directions. Landscape metrics provided in depth knowledge about the sprawl. Principal component analysis helped in prioritizing the metrics for detailed analyses. The results clearly indicates that whole landscape is aggregating to a large patch in 2010 as compared to earlier years which was dominated by several small patches. The large scale conversion of small patches to large single patch can be seen from 2006 to 2010. In the year 2010 patches are maximally aggregated indicating that the city is becoming more compact and more urbanised in recent years. Bangalore was the most sought after destination for its climatic condition and the availability of various facilities (land availability, economy, political factors) compared to other cities. The growth into a single urban patch can be attributed to rapid urbanisation coupled with the industrialisation. Monitoring of growth through landscape metrics helps to maintain and manage the natural resources.

Quantifying urban growth patterns in Hanoi using landscape expansion modes and time series spatial metrics

PubMed Central

Lepczyk, Christopher A.; Miura, Tomoaki; Fox, Jefferson M.

2018-01-01

Urbanization has been driven by various social, economic, and political factors around the world for centuries. Because urbanization continues unabated in many places, it is crucial to understand patterns of urbanization and their potential ecological and environmental impacts. Given this need, the objectives of our study were to quantify urban growth rates, growth modes, and resultant changes in the landscape pattern of urbanization in Hanoi, Vietnam from 1993 to 2010 and to evaluate the extent to which the process of urban growth in Hanoi conformed to the diffusion-coalescence theory. We analyzed the spatiotemporal patterns and dynamics of the built-up land in Hanoi using landscape expansion modes, spatial metrics, and a gradient approach. Urbanization was most pronounced in the periods of 2001–2006 and 2006–2010 at a distance of 10 to 35 km around the urban center. Over the 17 year period urban expansion in Hanoi was dominated by infilling and edge expansion growth modes. Our findings support the diffusion-coalescence theory of urbanization. The shift of the urban growth areas over time and the dynamic nature of the spatial metrics revealed important information about our understanding of the urban growth process and cycle. Furthermore, our findings can be used to evaluate urban planning policies and aid in urbanization issues in rapidly urbanizing countries. PMID:29734346

Resilient landscapes in Mediterranean urban areas: Understanding factors influencing forest trends.

PubMed

Tomao, Antonio; Quatrini, Valerio; Corona, Piermaria; Ferrara, Agostino; Lafortezza, Raffaele; Salvati, Luca

2017-07-01

Urban and peri-urban forests are recognized as basic elements for Nature-Based Solutions (NBS), as they preserve and may increase environmental quality in urbanized contexts. For this reason, the amount of forest land per inhabitant is a pivotal efficiency indicator to be considered in the sustainable governance, land management, planning and design of metropolitan areas. The present study illustrates a multivariate analysis of per-capita forest area (PFA) in mainland Attica, the urban region surrounding Athens, Greece. Attica is considered a typical case of Mediterranean urbanization where planning has not regulated urban expansion and successive waves of spontaneous growth have occurred over time. In such a context, an analysis of factors that can affect landscape changes in terms of PFA may inform effective strategies for the sustainable management of socio-ecological local systems in light of the NBS perspective. A total of 26 indicators were collected per decade at the municipal scale in the study area with the aim to identify the factors most closely associated to the amount of PFA. Indicators of urban morphology and functions have been considered together with environmental and topographical variables. In Attica, PFA showed a progressive decrease between 1960 and 2010. In particular, PFA progressively declined (1980, 1990) along fringe areas surrounding Athens and in peri-urban districts experiencing dispersed expansion of residential settlements. Distance from core cities and from the seacoast, typical urban functions (e.g., multiple use of buildings and per capita built-up area) and percentage of agricultural land-use in each municipality are the variables most associated with high PFA. In recent years, some municipalities have shown an expansion of forest cover, mainly due to land abandonment and forest recolonization. Findings from this case study have allowed us to identify priorities for NBS at metropolitan level aimed at promoting more sustainable urbanization. Distinctively, proposed NBS basically focus on (i) the effective protection of crop mosaics with relict woodlots; (ii) the improvement of functionality, quality and accessibility of new forests; and (iii) the establishment of new forests in rural municipalities. Copyright © 2017 Elsevier Inc. All rights reserved.

Interdisciplinary Study of Urbanization and Impacts - the Poplex 2014 Field Campaign

NASA Astrophysics Data System (ADS)

Nghiem, S. V.; Masetti, M.; Stevenazzi, S.; Bonfanti, M.; Conforto, A.; Filippini, M.; Fabbri, P.; Pola, M.; Sorichetta, A.; Linard, C.; Pampaloni, P.; Paloscia, S.; Santi, E. S.; Catani, F.; Neumann, G.

2014-12-01

Haphazard urban development may have far reaching impacts not only around the urban vicinity but also across regional and perhaps global scales. To investigate urban change and impacts, the PO PLain EXperiment (POPLEX) was conducted in May 2014. The focus of POPLEX was to conduct the most effective study, by closely coordinating the field campaign with the science team in different zones of the Po Plain in northern Italy, and also with an extension to Florence in the Tuscany region. Northern Italy is one of the most populated areas in Europe and most of its cities registered an urban sprawl pattern in the 2000s. In this view, the POPLEX domain represents a pertinent "pilot area" to identify environmental impacts due to urban sprawl. This is to identify and understand the influence of urban characteristics and urban change on important environmental topics such as: (a) groundwater resource quality assessment and management, (b) air quality assessment, and (c) temperature assessment. POPLEX involved 25 participants from 15 institutions from 5 countries using data from 12 satellites and extensive field networks including approximately 220 meteorological stations, 170 air monitoring stations, hundreds of groundwater monitoring wells, and 20 river gauges together with demographic census data and detailed survey maps of land cover and land use. Innovative processing, with the Dense Sampling Method and Rosette Transform applied to satellite scatterometer data, has allowed a successful development of a spatially and temporally consistent dataset delineating urban extension and thus to monitor the annual rate of changes, in each pixel of a 1-km grid, throughout the decade of 2000s across the landscape without spatial gaps. Such dataset enables the introduction of the time dimension into dynamic analyses combining both anthropogenic and natural factors including atmospheric, geophysical, and hydrogeological characteristics of each study area. Initial results have been obtained and will be presented on: (i) accelerated urbanization gradient in Milan transition areas, (ii) air pollution over urban areas and its constrain in the Po Plain surrounded by mountains, (iii) water contaminations due to urbanization in Lombardy, and (iv) hot-spot urbanization pattern of new built-up pockets in the Florence-Prato plain.

Urban Heat Island in the city of Bari (Italy) ant its relationship with morphological features

NASA Astrophysics Data System (ADS)

Ceppi, C.; Balena, P.; Loconte, P.; Mancini, F.

2012-04-01

The investigation of an Urban Heat Island (UHI) and its relationship with the wide range of factors able to explain its behavior is a very difficult task: the main trouble is represented by the spatial variability of the urban temperature due to the extreme heterogeneousness of the urban coverage and morphological features. In literature it is known that the local surface temperatures are influenced by the changing characteristics in urban surface and modification of land surface processes affecting the surface energy balance and the shape of boundary layer. The whole processes could lead to distinct urban climates. This work is mainly focused on the mechanisms which are actually connecting the urban morphology with the surface temperature as derived by satellite data provided from the ASTER sensor. Urban morphology could be described by several factors depending on the selected scale of analysis. At the macroscale the UHI is more related to the land-use, environmental context and boundary conditions. At the microscale the surface characteristics, urban density, ratio between green and built areas and, construction and built typology are more involved in addition to the composite indicators such as the Sky View factor and the elevation of the built texture. The case study of the city of Bari is faced. It is a medium sized city in the southern Italy, characterized by the presence of a pervasive waterfront and presence of "lame", a natural erosive furrows shallow that are typical of the Apulia country side. Such ephemeral streams convey the stormwater from the plateau of the hilly Murgia areas to the sea. Moreover, the urban complexity of the city exacerbates the spatial variability of the phenomenon. The first step aim at the investigating of the relationship between the thermal behavior and the above mentioned factors by the construction of a set of homogeneous morphological units. The classification is built both in the urban and rural zone. The second step focuses on the development of a spatial statistical analysis based on qualitative and quantitative indicators able to link the classes of urban morphology with the satellite-based surface temperature. The relationships highlighted by such a spatial analysis can be used to model the urban climate and, consequently, develop a new kind of planning more addressed towards the mitigation of the UHI phenomenon.

Connecting Urbanization to Precipitation: the case of Mexico City

NASA Astrophysics Data System (ADS)

Georgescu, Matei

2017-04-01

Considerable evidence exists illustrating the influence of urban environments on precipitation. We revisit this theme of significant interest to a broad spectrum of disciplines ranging from urban planning to engineering to urban numerical modeling and climate, by detailing the simulated effect of Mexico City's built environment on regional precipitation. Utilizing the Weather Research and Forecasting (WRF) system to determine spatiotemporal changes in near-surface air temperature, precipitation, and boundary layer conditions induced by the modern-day urban landscape relative to presettlement conditions, I mechanistically link the built environment-induced increase in air temperature to simulated increases in rainfall during the evening hours. This simulated increase in precipitation is in agreement with historical observations documenting observed rainfall increase. These results have important implications for understanding the meteorological conditions leading to the widespread and recurrent urban flooding that continues to plague the Mexico City Metropolitan Area.

A Backward-Lagrangian-Stochastic Footprint Model for the Urban Environment

NASA Astrophysics Data System (ADS)

Wang, Chenghao; Wang, Zhi-Hua; Yang, Jiachuan; Li, Qi

2018-02-01

Built terrains, with their complexity in morphology, high heterogeneity, and anthropogenic impact, impose substantial challenges in Earth-system modelling. In particular, estimation of the source areas and footprints of atmospheric measurements in cities requires realistic representation of the landscape characteristics and flow physics in urban areas, but has hitherto been heavily reliant on large-eddy simulations. In this study, we developed physical parametrization schemes for estimating urban footprints based on the backward-Lagrangian-stochastic algorithm, with the built environment represented by street canyons. The vertical profile of mean streamwise velocity is parametrized for the urban canopy and boundary layer. Flux footprints estimated by the proposed model show reasonable agreement with analytical predictions over flat surfaces without roughness elements, and with experimental observations over sparse plant canopies. Furthermore, comparisons of canyon flow and turbulence profiles and the subsequent footprints were made between the proposed model and large-eddy simulation data. The results suggest that the parametrized canyon wind and turbulence statistics, based on the simple similarity theory used, need to be further improved to yield more realistic urban footprint modelling.

Air Pollution Abatement Performances of Green Infrastructure in Open Road and Built-up Street Canyon Environments – A Review

EPA Science Inventory

Intensifying the proportion of urban green infrastructure has been considered as one of the remedies for air pollution levels in cities, yet the impact of numerous vegetation types deployed in different built environments has to be fully synthesised and quantified. This review ex...

[Built-up land change and its impact on ecological quality in a fast-growing economic zone: Jinjiang County, Fujian Province, China].

PubMed

Shi, Ting Ting; Xu, Han Qiu; Tang, Fei

2017-04-18

Since China's reform and opening-up, the rapid growth of China's economy has greatly accelerated the expansion of built-up land, which has affected regional ecological environment to a great extent. Taking Jinjiang County of Fujian Province, one of the fastest economic-developing counties in the coastal areas of southeastern China, as a case study area, this paper focused on analyzing the rapid built-up land expansion process of the county and its impact on county's ecological quality using remote sensing techniques. Based on two Landsat images of 1996 and 2015 of Jinjiang, the built-up land of the county was extracted using the index-based built-up index (IBI) and its change was analyzed. In the meantime, the ecological status of Jinjiang was evaluated with a recently-proposed remote sensing based ecological index (RSEI) and the relationship between the built-up land dynamics and the ecological status changes of the county was quantitatively examined. The results showed that during the period from 1996 to 2015, the area of built-up land of Jinjiang had a net increase of 68.54 km 2 , a growth of 45%, and the expansion intensity was 0.55. The expansion of the built-up lands has caused overall degradation of the county's ecological quality. The mean value of RSEI of the county had declined from 0.532 in 1996 to 0.460 in 2015, a drop of13.5%. The area proportion of high ecological-quality grades also significantly fell from 39% in 1996 to 21% in 2015. The built-up land expansion intensity was negatively correlated with the ecological quality change.

Restorative Qualities of and Preference for Natural and Urban Soundscapes.

PubMed

Krzywicka, Paulina; Byrka, Katarzyna

2017-01-01

Psychological restoration in urban agglomerations has become a growing challenge. Although scientific proof of the significance of nature is irrefutable, an increase in built-up areas has led to a decrease in urban greenery. Thus, a growing need for restorativeness in urban surroundings has emerged. To investigate whether positively evaluated sonic environments, represented by natural and urban sounds, have comparable restorative qualities we conducted two studies. The aim of the first (Study 1) was to explore the restorative qualities of positively assessed natural and urban sounds. Participants ( N = 88) were asked to listen and to rate 22 recordings (each 1 min long) either from natural or urban environments. In the second (Study 2) we investigated whether positively evaluated sonic environments (natural and urban), demand for restoration (feeling relaxed or fatigued) and company (being alone or with a friend) affect the restorative qualities of natural and urban soundscapes. After reading assigned scenarios (feeling relaxed or fatigued; being alone or with a friend), participants ( N = 120) were asked to imagine a walk in presented sonic environments and to complete forms (one for each sonic environment) concerning the restorative qualities of given soundscapes (natural and urban). Top five recordings of natural and urban sonic environments were selected from Study 1 and combined into a 154-s soundtrack, to provide a background for the imagined walks in both settings. Our findings confirmed that natural sounds are perceived more favorably than urban recordings. Even when only the most positively assessed soundscapes were compared, nature was still perceived as being more restorative than urban areas. Company of a friend was found to be more beneficial in the urban surroundings, particularly when there was no need for restoration.

Restorative Qualities of and Preference for Natural and Urban Soundscapes

PubMed Central

Krzywicka, Paulina; Byrka, Katarzyna

2017-01-01

Psychological restoration in urban agglomerations has become a growing challenge. Although scientific proof of the significance of nature is irrefutable, an increase in built-up areas has led to a decrease in urban greenery. Thus, a growing need for restorativeness in urban surroundings has emerged. To investigate whether positively evaluated sonic environments, represented by natural and urban sounds, have comparable restorative qualities we conducted two studies. The aim of the first (Study 1) was to explore the restorative qualities of positively assessed natural and urban sounds. Participants (N = 88) were asked to listen and to rate 22 recordings (each 1 min long) either from natural or urban environments. In the second (Study 2) we investigated whether positively evaluated sonic environments (natural and urban), demand for restoration (feeling relaxed or fatigued) and company (being alone or with a friend) affect the restorative qualities of natural and urban soundscapes. After reading assigned scenarios (feeling relaxed or fatigued; being alone or with a friend), participants (N = 120) were asked to imagine a walk in presented sonic environments and to complete forms (one for each sonic environment) concerning the restorative qualities of given soundscapes (natural and urban). Top five recordings of natural and urban sonic environments were selected from Study 1 and combined into a 154-s soundtrack, to provide a background for the imagined walks in both settings. Our findings confirmed that natural sounds are perceived more favorably than urban recordings. Even when only the most positively assessed soundscapes were compared, nature was still perceived as being more restorative than urban areas. Company of a friend was found to be more beneficial in the urban surroundings, particularly when there was no need for restoration. PMID:29046653

Numerical Study of the Wintertime Planetary Boundary Layer Development in the Urban Area of Sao Paulo - Brazil

NASA Astrophysics Data System (ADS)

Ribeiro, F. N. D.; Soares, J.; Oliveira, A. P.; Miranda, R. M.; Chen, F.

2015-12-01

The gradual replacement of natural by built surfaces and the ongoing emission of particulate matter and other pollutants that happens in urban environments, besides degrading the environment, influence the local weather and climate patterns. Urban areas have different albedo, heat and hydraulic capacity and conductivity, roughness, emissivity, and transmissivity, when compared to naturally vegetated areas. This set of characteristics may change the surface energy budget, air temperature, humidity, atmospheric chemical composition, wind direction and velocity, and therefore the planetary boundary layer (PBL) development. The effects of urbanization on the PBL have been studied in many mid-latitude areas, however in the tropical or subtropical areas they are scarce. The MCITY Brazil project developed in 2 cities of Brazil, Sao Paulo (23°32' S) and Rio de Janeiro (latitude 22° 55' S), has provided the necessary data to properly investigate the effects of urbanization in these two cities. The project included a campaign of soundings launched every 3 hours for 10 consecutive days in August (Austral winter) from an airport at the north part of the city of Sao Paulo, that allowed the study of the PBL development, and also the measurements of the components of the energy budget equation by micrometeorological towers. Therefore, the goal of this work is to simulate the development of the PBL in the metropolitan area of Sao Paulo during winter, comparing its characteristics in urbanized and non urbanized sites, in order to assess the impact of urbanization on the development of the PBL in this area. The model used is the Weather Research and Forecast (WRF) with a single layer urban canopy parameterization (SLUCM) and realistic anthropogenic heat diurnal evolution. Preliminary results showed that the model is able to reproduce the PBL development during the campaign, including the passage of a cold-frontal system. The urban PBL reaches greater heights during the day than the PBL in non urban sites, suggesting that the urban sites generate more turbulence. Daytime urban PBL height reaches up to 2000 m and nighttime is usually less than 200 m. The surface turbulent fluxes and the energy budget near the surface will also be compared to observations and discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Güneralp, Burak; Zhou, Yuyu; Ürge-Vorsatz, Diana

Urban areas play a significant role in planetary sustainability. While the scale of impending urbanization is well acknowledged, we have a limited understanding on how urban forms will change and what their impact will be on building energy use. Using both top-down and bottom-up approaches and scenarios, we examine building energy use, specifically, for heating and cooling. We also assess associated cobenefits and trade-offs with human well-being. Globally, the energy use for heating and cooling by midcentury will reach anywhere from about 45 EJ/yr to 59 EJ/yr (respectively, increases of 5% to 40% over the 2010 estimate). Most of thismore » variability is due to the uncertainty in future urban forms of rapidly growing cities in Asia and, particularly, in China. Compact urban development overall leads to less energy use in urban environments. Delaying the retrofit of the existing built environment leads to more savings in building energy use. Potential for savings in the energy use is greatest in China when coupled with efficiency gains. Advanced efficiency makes the least difference compared to the business-as-usual scenario in energy use for heating and cooling in South Asia and Sub-Saharan Africa but significantly contribute to energy savings in North America and Europe. A systemic effort that focuses on both urban form and energy-efficient technologies, but also accounts for potential co-benefits and trade-offs, can contribute to both local and global sustainability. Particularly in mega-urban regions, such efforts can improve local environments for billions of urban residents and contribute to mitigating climate change by reducing energy use in urban areas and associated greenhouse gas emissions.« less

Urban flooding and Resilience: concepts and needs

NASA Astrophysics Data System (ADS)

Gourbesville, Ph.

2012-04-01

During the recent years, a growing interest for resilience has been expressed in the natural disaster mitigation area and especially in the flood related events. The European Union, under the Seventh Framework Programme (FP7), has initiated several research initiatives in order to explore this concept especially for the urban environments. Under urban resilience is underlined the ability of system potentially exposed to hazard to resist, respond, recover and reflect up to stage which is enough to preserve level of functioning and structure. Urban system can be resilient to lot of different hazards. Urban resilience is defined as the degree to which cities are able to tolerate some disturbance before reorganizing around a new set of structures and processes (Holling 1973, De Bruijn 2005). The United Nation's International strategy for Disaster Reductions has defined resilience as "the capacity of a system, community or society potentially exposed to hazards to adapt, by resisting or changing in order to reach and maintain an acceptable level of functioning and structure. This is determined by the degree to which the social system is capable of organizing itself to increase this capacity for learning from past disasters for better future protection and to improve risk reduction measures."(UN/ISDR 2004). According to that, system should be able to accept the hazard and be able to recover up to condition that provides acceptable operational level of city structure and population during and after hazard event. Main elements of urban system are built environment and population. Physical characteristic of built environment and social characteristic of population have to be examined in order to evaluate resilience. Therefore presenting methodology for assessing flood resilience in urban areas has to be one of the focal points for the exposed cities. Strategies under flood management planning related to resilience of urban systems are usually regarding controlling runoff volume, increasing capacity of drainage systems, spatial planning, building regulations, etc. Resilience also considers resilience of population to floods and it's measured with time. Assessment of resilience that is focused on population is following bottom-up approach starting from individual and then assessing community level. Building resilience involves also contribution of social networks, increasing response capacity of communities, self-organization, learning and education and cheering adaptation culture. Measures for improving social side of resilience covers: raising public awareness, implementation of flood forecasting and warning, emergency response planning and training, sharing information, education and communication. Most of these aspects are analyzed with the CORFU FP7 project. Collaborative Research on Flood Resilience in Urban areas (CORFU) is a major project involving 17 European and Asian institutions, funded by a grant from the European Commission under the Seventh Framework Programme. The overall aim of CORFU is to enable European and Asian partners to learn from each other through joint investigation, development, implementation and dissemination of short to medium term strategies that will enable more scientifically sound management of the consequences of urban flooding in the future and to develop resilience strategies according to each situation. The CORFU project looks at advanced and novel strategies and provide adequate measures for improved flood management in cities. The differences in urban flooding problems in Asia and in Europe range from levels of economic development, infrastructure age, social systems and decision making processes, to prevailing drainage methods, seasonality of rainfall patterns and climate change trends. The study cases are, in Europe, the cities of Hamburg, Barcelona and Nice, and in Asia, Beijing, Dhaka, Mumbai, Taipei, Seoul and Incheon.

Sub-kilometer Numerical Weather Prediction in complex urban areas

NASA Astrophysics Data System (ADS)

Leroyer, S.; Bélair, S.; Husain, S.; Vionnet, V.

2013-12-01

A Sub-kilometer atmospheric modeling system with grid-spacings of 2.5 km, 1 km and 250 m and including urban processes is currently being developed at the Meteorological Service of Canada (MSC) in order to provide more accurate weather forecasts at the city scale. Atmospheric lateral boundary conditions are provided with the 15-km Canadian Regional Deterministic Prediction System (RDPS). Surface physical processes are represented with the Town Energy Balance (TEB) model for the built-up covers and with the Interactions between the Surface, Biosphere, and Atmosphere (ISBA) land surface model for the natural covers. In this study, several research experiments over large metropolitan areas and using observational networks at the urban scale are presented, with a special emphasis on the representation of local atmospheric circulations and their impact on extreme weather forecasting. First, numerical simulations are performed over the Vancouver metropolitan area during a summertime Intense Observing Period (IOP of 14-15 August 2008) of the Environmental Prediction in Canadian Cities (EPiCC) observational network. The influence of the horizontal resolution on the fine-scale representation of the sea-breeze development over the city is highlighted (Leroyer et al., 2013). Then severe storms cases occurring in summertime within the Greater Toronto Area (GTA) are simulated. In view of supporting the 2015 PanAmerican and Para-Pan games to be hold in GTA, a dense observational network has been recently deployed over this region to support model evaluations at the urban and meso scales. In particular, simulations are conducted for the case of 8 July 2013 when exceptional rainfalls were recorded. Leroyer, S., S. Bélair, J. Mailhot, S.Z. Husain, 2013: Sub-kilometer Numerical Weather Prediction in an Urban Coastal Area: A case study over the Vancouver Metropolitan Area, submitted to Journal of Applied Meteorology and Climatology.

Numerical Studies of Thermal Conditions in Cities - Systematic Model Simulations of Idealized Urban Domains

NASA Astrophysics Data System (ADS)

Heene, V.; Buchholz, S.; Kossmann, M.

2016-12-01

Numerical studies of thermal conditions in cities based on model simulations of idealized urban domains are carried out to investigate how changes in the characteristics of urban areas influence street level air temperatures. The simulated modifications of the urban characteristics represent possible adaptation measures for heat reduction in cities, which are commonly used in urban planning. Model simulations are performed with the thermodynamic version of the 3-dimensional micro-scale urban climate model MUKLIMO_3. The simulated idealized urban areas are designed in a simplistic way, i. e. defining homogeneous squared cities of one settlement type, without orography and centered in the model domain. To assess the impact of different adaptation measures the characteristics of the urban areas have been systematically modified regarding building height, albedo of building roof and impervious surfaces, fraction of impervious surfaces between buildings, and percentage of green roofs. To assess the impact of green and blue infrastructure in cities, different configurations for parks and lakes have been investigated - e. g. varying size and distribution within the city. The experiments are performed for different combinations of typical German settlement types and surrounding rural types under conditions of a typical summer day in July. The adaptation measures implemented in the experiments show different impacts for different settlement types mainly due to the differences in building density, building height or impervious surface fraction. Parks and lakes implemented as adaptation measure show strong potential to reduce daytime air temperature, with cooling effects on their built-up surroundings. At night lakes generate negative and positive effects on air temperature, depending on water temperature. In general, all adaptation measures implemented in experiments reveal different impacts on day and night air temperature.

Comparative Analysis of InSAR Digital Surface Models for Test Area Bucharest

NASA Astrophysics Data System (ADS)

Dana, Iulia; Poncos, Valentin; Teleaga, Delia

2010-03-01

This paper presents the results of the interferometric processing of ERS Tandem, ENVISAT and TerraSAR- X for digital surface model (DSM) generation. The selected test site is Bucharest (Romania), a built-up area characterized by the usual urban complex pattern: mixture of buildings with different height levels, paved roads, vegetation, and water bodies. First, the DSMs were generated following the standard interferometric processing chain. Then, the accuracy of the DSMs was analyzed against the SPOT HRS model (30 m resolution at the equator). A DSM derived by optical stereoscopic processing of SPOT 5 HRG data and also the SRTM (3 arc seconds resolution at the equator) DSM have been included in the comparative analysis.

Air pollution abatement performances of green infrastructure in open road and built-up street canyon environments - A review

NASA Astrophysics Data System (ADS)

Abhijith, K. V.; Kumar, Prashant; Gallagher, John; McNabola, Aonghus; Baldauf, Richard; Pilla, Francesco; Broderick, Brian; Di Sabatino, Silvana; Pulvirenti, Beatrice

2017-08-01

Intensifying the proportion of urban green infrastructure has been considered as one of the remedies for air pollution levels in cities, yet the impact of numerous vegetation types deployed in different built environments has to be fully synthesised and quantified. This review examined published literature on neighbourhood air quality modifications by green interventions. Studies were evaluated that discussed personal exposure to local sources of air pollution under the presence of vegetation in open road and built-up street canyon environments. Further, we critically evaluated the available literature to provide a better understanding of the interactions between vegetation and surrounding built-up environments and ascertain means of reducing local air pollution exposure using green infrastructure. The net effects of vegetation in each built-up environment are also summarised and possible recommendations for the future design of green infrastructure are proposed. In a street canyon environment, high-level vegetation canopies (trees) led to a deterioration in air quality, while low-level green infrastructure (hedges) improved air quality conditions. For open road conditions, wide, low porosity and tall vegetation leads to downwind pollutant reductions while gaps and high porosity vegetation could lead to no improvement or even deteriorated air quality. The review considers that generic recommendations can be provided for vegetation barriers in open road conditions. Green walls and roofs on building envelopes can also be used as effective air pollution abatement measures. The critical evaluation of the fundamental concepts and the amalgamation of key technical features of past studies by this review could assist urban planners to design and implement green infrastructures in the built environment.

Analysis of the effect of local heat island in Seoul using LANDSAT image

NASA Astrophysics Data System (ADS)

Lee, K. I.; Ryu, J.; Jeon, S. W.

2017-12-01

The increase in the rate of industrialization due to urbanization has caused the Urban Heat Island phenomenon which means that the temperature of the city is higher than the surrounding area, and its intensity is increasing with climate change. Among the cities where heat island phenomenon occur, Seoul city has different degree of urbanization, green area ratio, energy consumption, and population density by each district unit. As a result, the strength of heat island phenomenon is also different. The average maximum temperature in each region may differ by more than 3 °, which is bigger than the suburbs in Seoul and it means that analysis of UHI effect by regional unit is needed. Therefore, this study is to extract the UHI Intensity of the regional unit of the Seoul Metropolitan City using the satellite image, analyzed the difference of intensity according to the regional unit. And do linear regression analysis with variables included in three categories(regional meteorological conditions, anthropogenic heat generation, land use factors). As a result, The UHI Intensity value of the Gu unit is significantly different from the UHI Intensity distribution of the Dong unit. The variable having the greatest positive correlation with UHI Intensity was NDBI(Normalized Difference Built-up Index) which shows the distribution of urban area, and Urban area ratio also has high correlation. There was a negative correlation between mean wind speed but there was no significant correlation between population density and power consumption. The result of this study is to identify the regional difference of UHI Intensity and to identify the factors inducing heat island phenomenon. so It is expected that it will provide direction in urban thermal environment design and policy development in the future.

Extracting Urban Morphology for Atmospheric Modeling from Multispectral and SAR Satellite Imagery

NASA Astrophysics Data System (ADS)

Wittke, S.; Karila, K.; Puttonen, E.; Hellsten, A.; Auvinen, M.; Karjalainen, M.

2017-05-01

This paper presents an approach designed to derive an urban morphology map from satellite data while aiming to minimize the cost of data and user interference. The approach will help to provide updates to the current morphological databases around the world. The proposed urban morphology maps consist of two layers: 1) Digital Elevation Model (DEM) and 2) land cover map. Sentinel-2 data was used to create a land cover map, which was realized through image classification using optical range indices calculated from image data. For the purpose of atmospheric modeling, the most important classes are water and vegetation areas. The rest of the area includes bare soil and built-up areas among others, and they were merged into one class in the end. The classification result was validated with ground truth data collected both from field measurements and aerial imagery. The overall classification accuracy for the three classes is 91 %. TanDEM-X data was processed into two DEMs with different grid sizes using interferometric SAR processing. The resulting DEM has a RMSE of 3.2 meters compared to a high resolution DEM, which was estimated through 20 control points in flat areas. Comparing the derived DEM with the ground truth DEM from airborne LIDAR data, it can be seen that the street canyons, that are of high importance for urban atmospheric modeling are not detectable in the TanDEM-X DEM. However, the derived DEM is suitable for a class of urban atmospheric models. Based on the numerical modeling needs for regional atmospheric pollutant dispersion studies, the generated files enable the extraction of relevant parametrizations, such as Urban Canopy Parameters (UCP).

Decentralized sensor fusion for Ubiquitous Networking Robotics in Urban Areas.

PubMed

Sanfeliu, Alberto; Andrade-Cetto, Juan; Barbosa, Marco; Bowden, Richard; Capitán, Jesús; Corominas, Andreu; Gilbert, Andrew; Illingworth, John; Merino, Luis; Mirats, Josep M; Moreno, Plínio; Ollero, Aníbal; Sequeira, João; Spaan, Matthijs T J

2010-01-01

In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted.

Microhabitats occupied by Loxosceles intermedia and Loxosceles laeta (Araneae: Sicariidae) in Curitiba, Paraná, Brazil.

PubMed

Fischer, Marta Luciane; Vasconcellos-Neto, João

2005-09-01

A survey was done of the environments and substrata occupied by Loxosceles intermedia Mello-Leitão, 1934 and Loxosceles laeta (Nicolet, 1849) (Araneae: Sicariidae) in urban woods and anthropic constructions in Curitiba. In total, 2,099 trees, 364 decaying logs as well as stones and roots, built-up areas, and wasteland in six urban parks and 60 residences were inspected. In total, 1,775 m2 of vegetation was inspected, but spiders and their vestiges were collected only in and around buildings in urban parks and residences. L. intermedia was more common than L. laeta and occurred both indoors and outdoors, whereas L. laeta was more common indoors in wooden houses. The two species did not occur in the same microhabitats, although both preferred paper, wood, and construction materials. Spiders collected in urban parks were heavier than those collected in residences, although only males collected in urban parks were larger than those from residences. The lack of vestiges indicative of a previous occupation in the urban parks suggested that both species occupied primarily the anthropic environment where they found numerous substrata that offered thermal isolation and suitable conditions for web fixation, ecdysis, and reproduction.

Spatio-temporal footprints of urbanisation in Surat, the Diamond City of India (1990-2009).

PubMed

Sharma, Richa; Ghosh, Aniruddha; Joshi, Pawan Kumar

2013-04-01

Urbanisation is a ubiquitous phenomenon with greater prominence in developing nations. Urban expansion involves land conversions from vegetated moisture-rich to impervious moisture-deficient land surfaces. The urban land transformations alter biophysical parameters in a mode that promotes development of heat islands and degrades environmental health. This study elaborates relationships among various environmental variables using remote sensing dataset to study spatio-temporal footprint of urbanisation in Surat city. Landsat Thematic Mapper satellite data were used in conjugation with geo-spatial techniques to study urbanisation and correlation among various satellite-derived biophysical parameters, [Normalised Difference Vegetation Index, Normalised Difference Built-up Index, Normalised Difference Water Index, Normalised Difference Bareness Index, Modified NDWI and land surface temperature (LST)]. Land use land cover was prepared using hierarchical decision tree classification with an accuracy of 90.4 % (kappa = 0.88) for 1990 and 85 % (kappa = 0.81) for 2009. It was found that the city has expanded over 42.75 km(2) within a decade, and these changes resulted in elevated surface temperatures. For example, transformation from vegetation to built-up has resulted in 5.5 ± 2.6 °C increase in land surface temperature, vegetation to fallow 6.7 ± 3 °C, fallow to built-up is 3.5 ± 2.9 °C and built-up to dense built-up is 5.3 ± 2.8 °C. Directional profiling for LST was done to study spatial patterns of LST in and around Surat city. Emergence of two new LST peaks for 2009 was observed in N-S and NE-SW profiles.

Global scenarios of urban density and its impacts on building energy use through 2050

DOE PAGES

Guneralp, Burak; Zhou, Yuyu; Urge-Vorsatz, Diana; ...

2017-01-09

Here, urban areas play a significant role in planetary sustainability. While the scale of impending urbanization is well acknowledged, we have a limited understanding on how urban forms will change and what their impact will be on building energy use. Using both top-down and bottom-up approaches and scenarios, we examine building energy use, specifically, for heating and cooling. We also assess associated cobenefits and trade-offs with human well-being. Globally, the energy use for heating and cooling by midcentury will reach anywhere from about 45 EJ/yr to 59 EJ/yr (respectively, increases of 5% to 40% over the 2010 estimate). Most ofmore » this variability is due to the uncertainty in future urban forms of rapidly growing cities in Asia and, particularly, in China. Compact urban development overall leads to less energy use in urban environments. Delaying the retrofit of the existing built environment leads to more savings in building energy use. Potential for savings in the energy use is greatest in China when coupled with efficiency gains. Advanced efficiency makes the least difference compared to the business-as-usual scenario in energy use for heating and cooling in South Asia and Sub-Saharan Africa but significantly contribute to energy savings in North America and Europe. A systemic effort that focuses on both urban form and energy-efficient technologies, but also accounts for potential co-benefits and trade-offs, can contribute to both local and global sustainability. Particularly in mega-urban regions, such efforts can improve local environments for billions of urban residents and contribute to mitigating climate change by reducing energy use in urban areas and associated greenhouse gas emissions.« less

Global scenarios of urban density and its impacts on building energy use through 2050

DOE Office of Scientific and Technical Information (OSTI.GOV)

Güneralp, Burak; Zhou, Yuyu; Ürge-Vorsatz, Diana

2017-01-09

Urban areas play a significant role in planetary sustainability. While the scale of impending urbanization is well acknowledged, we have a limited understanding on how urban forms will change and what their impact will be on building energy use. Using both top-down and bottom-up approaches and scenarios, we examine building energy use, specifically, for heating and cooling. We also assess associated cobenefits and trade-offs with human well-being. Globally, the energy use for heating and cooling by midcentury will reach anywhere from about 45 EJ/yr to 59 EJ/yr (respectively, increases of 5% to 40% over the 2010 estimate). Most of thismore » variability is due to the uncertainty in future urban forms of rapidly growing cities in Asia and, particularly, in China. Compact urban development overall leads to less energy use in urban environments. Delaying the retrofit of the existing built environment leads to more savings in building energy use. Potential for savings in the energy use is greatest in China when coupled with efficiency gains. Advanced efficiency makes the least difference compared to the business-as-usual scenario in energy use for heating and cooling in South Asia and Sub-Saharan Africa but significantly contribute to energy savings in North America and Europe. A systemic effort that focuses on both urban form and energy-efficient technologies, but also accounts for potential co-benefits and trade-offs, can contribute to both local and global sustainability. Particularly in mega-urban regions, such efforts can improve local environments for billions of urban residents and contribute to mitigating climate change by reducing energy use in urban areas and associated greenhouse gas emissions.« less

Urban ventilation corridors mapping using surface morphology data based GIS analysis

NASA Astrophysics Data System (ADS)

Wicht, Marzena; Wicht, Andreas; Osińska-Skotak, Katarzyna

2017-04-01

This paper describes deriving the most appropriate method for mapping urban ventilation corridors, which, if properly designed, reduce heat stress, air pollution and increase air quality, as well as increase the horizontal wind speed. Urban areas are - in terms of surface texture - recognized as one of the roughest surfaces, which results in wind obstruction and decreased ventilation of densely built up areas. As urban heat islands, private household and traffic emissions or large scale industries occur frequently in many cities, both in temperate and tropical regions. A proper ventilation system has been suggested as an appropriate mitigation mean [1] . Two concepts of morphometric analyses of the urban environment are used on the example of Warsaw, representing a dense, urban environment, located in the temperate zone. The utilized methods include firstly a roughness mapping calculation [2] , which analyses zero plane displacement height (zd) and roughness length (z0) and their distribution for the eight (inter-)cardinal wind directions and secondly a grid-based frontal area index mapping approach [3] , which uses least cost path analysis. Utilizing the advantages and minimizing the disadvantages of those two concepts, we propose a hybrid approach. All concepts are based on a 3D building database obtained from satellite imagery, aided by a cadastral building database. Derived areas (ventilation corridors), that facilitate the ventilation system, should be considered by the local authorities as worth preserving, if not expanding, in order to improve the air quality in the city. The results also include designation of the problematic areas, which greatly obscure the ventilation and might be investigated as to reshape or rebuilt to introduce the air flow in particularly dense areas like city centers. Keywords: roughness mapping; GIS; ventilation corridors; frontal area index Rizwan, A. M., Dennis, L. Y., & Chunho, L. I. U. (2008). A review on the generation, determination and mitigation of Urban Heat Island. Journal of Environmental Sciences, 20(1), 120-128. Gál, T., & Unger, J. (2009). Detection of ventilation paths using high-resolution roughness parameter mapping in a large urban area. Building and Environment, 44(1), 198-206. Wong, M. S., Nichol, J. E., To, P. H., & Wang, J. (2010). A simple method for designation of urban ventilation corridors and its application to urban heat island analysis. Building and Environment, 45(8), 1880-1889.

The inhabited environment, infrastructure development and advanced urbanization in China’s Yangtze River Delta Region

NASA Astrophysics Data System (ADS)

Zhu, Xiaoqing; Gao, Weijun; Zhou, Nan; Kammen, Daniel M.; Wu, Yiqun; Zhang, Yao; Chen, Wei

2016-12-01

This paper analyzes the relationship among the inhabited environment, infrastructure development and environmental impacts in China’s heavily urbanized Yangtze River Delta region. Using primary human environment data for the period 2006-2014, we examine factors affecting the inhabited environment and infrastructure development: urban population, GDP, built-up area, energy consumption, waste emission, transportation, real estate and urban greenery. Then we empirically investigate the impact of advanced urbanization with consideration of cities’ differences. Results from this study show that the growth rate of the inhabited environment and infrastructure development is strongly influenced by regional development structure, functional orientations, traffic network and urban size and form. The effect of advanced urbanization is more significant in large and mid-size cities than huge and mega cities. Energy consumption, waste emission and real estate in large and mid-size cities developed at an unprecedented rate with the rapid increase of economy. However, urban development of huge and mega cities gradually tended to be saturated. The transition development in these cities improved the inhabited environment and ecological protection instead of the urban construction simply. To maintain a sustainable advanced urbanization process, policy implications included urban sprawl control polices, ecological development mechanisms and reforming the economic structure for huge and mega cities, and construct major cross-regional infrastructure, enhance the carrying capacity and improvement of energy efficiency and structure for large and mid-size cities.

Urban and regional land use analysis: CARETS and Census Cities experiment package

NASA Technical Reports Server (NTRS)

Alexander, R. H. (Principal Investigator); Milazzo, V. A.

1973-01-01

The author has identified the following significant results. Areas of post 1970 and 1972 land use changes were identified solely from the Skylab imagery from comparisons with 1970 land use maps. Most land use changes identified involved transition from agriculture to single family residential land use. The second most prominent changes identified from the Skylab imagery were areas presently under construction. Post 1970 changes from Skylab were compared with the 1972 changes noted from the high altitude photographs. A good correlation existed between the change polygons mapped from Skylab and those mapped from the 1972 high altitude aerial photos. In addition, there were a number of instances where additional built-up land use not noted in the 1972 aerial photo as being developed were identified on the Skylab imagery. While these cases have not been documented by field observation, by correlating these areas with the appearance of similar land use areas whose identity has been determined, we can safely say that we have been able to map further occurrences of land use change beyond existing high altitude photo coverage from the Skylab imagery. It was concluded that Skylab data can be used to detect areas of land use change within an urban setting.

How does the seasonality influence utilitarian walking behaviour in different urbanization settings in Scotland?

PubMed

Hong, Jinhyun

2016-08-01

The relationship between the built environment and walking has been analyzed for decades. However, the seasonality effects on the relationship between the built environment and walking have not been well examined even though weather is one of the key determinants of walking. Therefore, this study used 2007-8 Scottish Household Survey data collected over two years and estimated the interaction effects between the urbanization setting (i.e., residential locations: urban, town and rural areas) and seasons (i.e., spring, summer, autumn and winter) on walking. Scottish Urban-rural classification scheme is measured based on the population and access to large cities, and used as a key independent variable. The number of walking days for specific purposes such as work or shopping (utilitarian walking) during the past 7 days is used as a dependent variable. The results show that there are significant geographical variations of seasonality effect on utilitarian walking. That is, people living in rural areas are more sensitive to seasonality impacts than those living in urban areas. In addition, we found that the association between urbanization setting and utilitarian walking varies across seasons, indicating that their relationship can be miss-estimated if we ignore the seasonality effects. Therefore, policy makers and practitioners should consider the seasonality effects to evaluate the effectiveness of land use policy correctly. Finally, we still find the significant association between the urbanization setting and utilitarian walking behaviour with the consideration of seasonality effects, supporting the claim of New Urbanism. Copyright © 2016 Elsevier Ltd. All rights reserved.

Urban Shanty Town Recognition Based on High-Resolution Remote Sensing Images and National Geographical Monitoring Features - a Case Study of Nanning City

NASA Astrophysics Data System (ADS)

He, Y.; He, Y.

2018-04-01

Urban shanty towns are communities that has contiguous old and dilapidated houses with more than 2000 square meters built-up area or more than 50 households. This study makes attempts to extract shanty towns in Nanning City using the product of Census and TripleSat satellite images. With 0.8-meter high-resolution remote sensing images, five texture characteristics (energy, contrast, maximum probability, and inverse difference moment) of shanty towns are trained and analyzed through GLCM. In this study, samples of shanty town are well classified with 98.2 % producer accuracy of unsupervised classification and 73.2 % supervised classification correctness. Low-rise and mid-rise residential blocks in Nanning City are classified into 4 different types by using k-means clustering and nearest neighbour classification respectively. This study initially establish texture feature descriptions of different types of residential areas, especially low-rise and mid-rise buildings, which would help city administrator evaluate residential blocks and reconstruction shanty towns.

Subsurface information for risk-sensitive urban spatial planning in Dhaka Metropolitan City, Bangladesh

NASA Astrophysics Data System (ADS)

Günther, Andreas; Aziz Patwary, Mohammad Abdul; Bahls, Rebecca; Asaduzzaman, Atm; Ludwig, Rüdiger; Ashraful Kamal, Mohammad; Nahar Faruqa, Nurun; Jabeen, Sarwat

2016-04-01

Dhaka Metropolitan City (including Dhaka and five adjacent municipal areas) is one of the fastest developing urban regions in the world. Densely build-up areas in the developed metropolitan area of Dhaka City are subject to extensive restructuring as common six- or lower storied buildings are replaced by higher and heavier constructions. Additional stories are built on existing houses, frequently exceeding the allowable bearing pressure on the subsoil as supported by the foundations. In turn, newly developing city areas are projected in marshy terrains modified by extensive, largely unengineered landfills. In most areas, these terrains bear unfavorable building ground conditions within 30 meters. Within a collaborative technical cooperation project between Bangladesh and Germany, BGR supports GSB in the provision of geo-information for the Capital Development Authority (RAJUK). For general urban planning, RAJUK successively develops a detailed area plan (DAP) at scale 1 : 50000 for the whole Dhaka Metropolitan City area (approx. 1700 km2). Geo-information have not been considered in the present DAP. Within the project, geospatial information in form of a geomorphic map, a digital terrain model and a 3-D subsurface model covering the whole city area have been generated at a scale of 1 : 50000. An extensive engineering geological data base consisting of more than 2200 borehole data with associated Standard Penetration Testing (SPT) and lab data has been compiled. With the field testing (SPT) and engineering geological lab data, the 3-D subsurface model can be parameterized to derive important spatial subsurface information for urban planning like bearing capacity evaluations for different foundation designs or soil liquefaction potential assessments for specific earthquake scenarios. In conjunction with inundation potential evaluations for different flooding scenarios, comprehensive building ground suitability information can be derived to support risk-sensitive urban planning in Dhaka Metropolitan City area at the DAP scale

Assessing the relationship between surface urban heat islands and landscape patterns across climatic zones in China.

PubMed

Yang, Qiquan; Huang, Xin; Li, Jiayi

2017-08-24

The urban heat island (UHI) effect exerts a great influence on the Earth's environment and human health and has been the subject of considerable attention. Landscape patterns are among the most important factors relevant to surface UHIs (SUHIs); however, the relationship between SUHIs and landscape patterns is poorly understood over large areas. In this study, the surface UHI intensity (SUHII) is defined as the temperature difference between urban and suburban areas, and the landscape patterns are quantified by the urban-suburban differences in several typical landscape metrics (ΔLMs). Temperature and land-cover classification datasets based on satellite observations were applied to analyze the relationship between SUHII and ΔLMs in 332 cities/city agglomerations distributed in different climatic zones of China. The results indicate that SUHII and its correlations with ΔLMs are profoundly influenced by seasonal, diurnal, and climatic factors. The impacts of different land-cover types on SUHIs are different, and the landscape patterns of the built-up and vegetation (including forest, grassland, and cultivated land) classes have the most significant effects on SUHIs. The results of this study will help us to gain a deeper understanding of the relationship between the SUHI effect and landscape patterns.

Trends of tropospheric NO2 over the Yangtze River Delta region and the possible linkage to rapid urbanization

NASA Astrophysics Data System (ADS)

Ma, Mingliang; Zhang, Deying; Liu, Qiyang; Song, Yue; Zhou, Jiayuan; Shi, Runhe; Gao, Wei

2017-09-01

Over the past decade, China has experienced a rapid increase in urbanization. The urban built-up areas (population) of Shanghai increased by 16.1% (22.9%) from 2006 to 2015. This study aims to analyze the variations of tropospheric NO2 over Yangtze River Delta region and the impacts of rapid urbanization during 2006-2015. The results indicate that tropospheric NO2 vertical column density (VCD) of all cities in the study area showed an increasing trend during 2006-2011 whereas a decreasing trend during 2011-2015. Most cities showed a lower tropospheric NO2 VCD value in 2015 compared to that in 2006, except for Changzhou and Nantong. Shanghai and Ningbo are two hotspots where the tropospheric NO2 VCD decreased most significantly, at a rate of 22% and 19%, respectively. This effect could be ascribed to the implementation of harsh emission control policies therein. Similar seasonal variability was observed over all cities, with larger values observed in the summer and smaller values shown in the winter. Further investigations show that the observed increasing trend of tropospheric NO2 during 2006-2011 could be largely explained by rapid urbanization linked to car ownership, GDP, power consumption, population and total industrial output. Such effect was not prominent after 2011, mainly due to the implementation of emission control strategies.

An integrated approach to assess the dynamics of a peri-urban watershed influenced by wastewater irrigation

NASA Astrophysics Data System (ADS)

Mahesh, Jampani; Amerasinghe, Priyanie; Pavelic, Paul

2015-04-01

In many urban and peri-urban areas of India, wastewater is under-recognized as a major water resource. Wastewater irrigated agriculture provides direct benefits for the livelihoods and food security of many smallholder farmers. A rapidly urbanizing peri-urban micro-watershed (270 ha) in Hyderabad was assessed over a 10-year period from 2000 to 2010 for changes in land use and associated farming practices, farmer perceptions, socio-economic evaluation, land-use suitability for agriculture and challenges in potential irrigated area development towards wastewater use. This integrated approach showed that the change in the total irrigated area was marginal over the decade, whereas the built-up area within the watershed boundaries doubled and there was a distinct shift in cropping patterns from paddy rice to paragrass and leafy vegetables. Local irrigation supplies were sourced mainly from canal supplies, which accounted for three-quarters of the water used and was largely derived from wastewater. The remainder was groundwater from shallow hard-rock aquifers. Farmer perception was that the high nutrient content of the wastewater was of value, although they were also interested to pay modest amounts for additional pre-treatment. The shift in land use towards paragrass and leafy vegetables was attributed to increased profitability due to the high urban demand. The unutilised scrubland within the watershed has the potential for irrigation development, but the major constraints appear to be unavailability of labour and high land values rather than water availability. The study provides evidence to support the view that the opportunistic use of wastewater and irrigation practices, in general, will continue even under highly evolving peri-urban conditions, to meet the livelihood needs of the poor driven by market demands, as urban sprawl expands into cultivable rural hinterlands. Policy support is needed for enhanced recognition of wastewater for agriculture, with flow-on benefits including improved public health and protection of ecosystem services.

Electricity Consumption Risk Map - The use of Urban Climate Mapping for smarter analysis: Case study for Birmingham, UK.

NASA Astrophysics Data System (ADS)

Antunes Azevedo, Juliana; Burghardt, René; Chapman, Lee; Katzchner, Lutz; Muller, Catherine L.

2015-04-01

Climate is a key driving factor in energy consumption. However, income, vegetation, building mass structure, topography also impact on the amount of energy consumption. In a changing climate, increased temperatures are likely to lead to increased electricity consumption, affecting demand, distribution and generation. Furthermore, as the world population becomes more urbanized, increasing numbers of people will need to deal with not only increased temperatures from climate change, but also from the unintentional modification of the urban climate in the form of urban heat islands. Hence, climate and climate change needs to be taken into account for future urban planning aspects to increase the climate and energy resilience of the community and decrease the future social and economic costs. Geographical Information Systems provide a means to create urban climate maps as part of the urban planning process. Geostatistical analyses linking these maps with demographic and social data, enables a geo-statistical analysis to identify linkages to high-risk groups of the community and vulnerable areas of town and cities. Presently, the climatope classification is oriented towards thermal aspects and the ventilation quality (roughness) of the urban areas but can also be adapted to take into account other structural "environmental factors". This study aims to use the climatope approach to predict areas of potential high electricity consumption in Birmingham, UK. Several datasets were used to produce an average surface temperature map, vegetation map, land use map, topography map, building height map, built-up area roughness calculations, an average air temperature map and a domestic electricity consumption map. From the correlations obtained between the layers it is possible to average the importance of each factor and create a map for domestic electricity consumption to understand the influence of environmental aspects on spatial energy consumption. Based on these results city planners and local authorities can guide their directives and policies towards electricity consumption, demand, generation and distribution.

Network of Green Areas within Collective Housing Communities - Case Study from Timişoara, Romania

NASA Astrophysics Data System (ADS)

Branea, Ana-Maria; Stelian Găman, Marius; Bădescu, Ştefana

2017-10-01

Green areas have always been an essential feature of urban developments, improving the quality of life within a community, both from a social perspective - offering residents a place for relaxation and interaction, as well as from the point of view of disease prevention - improving the overall air quality, but also encouraging inhabitants to spend more time outside. The importance of these areas within a settlement further increases in the present-day context, in which the constant expansion of cities in their surrounding territory, phenomenon known as “urban sprawl”, gradually eliminates the natural green spaces and agricultural terrains from our landscape. This trend has devastating effects on the environment, as well as on the micro-climate of our settlements, characterized, in recent years, by the formation of heat islands within the built tissue. Moreover, the disappearance of natural green areas leads to the constant estrangement of the inhabitants, and especially of young generations, from the natural values and realities. It is thus more important than ever to ensure an adequate percentage of green areas for our cities, uniformly distributed within the urban tissue. Green belts, urban forests, parks, green squares or even urban gardens - all these entities play their parts within the urban green network, having certain radiuses of influence and attraction and thus occupying a specific position within the urban hierarchy. In Romania, the terrains left un-built between the collective housing buildings - or apartment blocks, erected during the communist administration and currently constituting public property, have a huge potential regarding the matter of urban greenery, being easily transformed into active and qualitative green areas. However, the local authorities lack the resources (both financial and in terms of human resources) to efficiently develop and then administrate these areas, which are consequently either abandoned, or used as illegal parking lots. This paper therefore explores the possibilities in which the terrains between collective housing buildings can be exploited by the community and transformed into qualitative green areas, as well as their integration within the hierarchy of the existing green network.

Albedo, Land Cover, and Daytime Surface Temperature Variation Across an Urbanized Landscape

NASA Astrophysics Data System (ADS)

Trlica, A.; Hutyra, L. R.; Schaaf, C. L.; Erb, A.; Wang, J. A.

2017-11-01

Land surface albedo is a key parameter controlling the local energy budget, and altering the albedo of built surfaces has been proposed as a tool to mitigate high near-surface temperatures in the urban heat island. However, most research on albedo in urban landscapes has used coarse-resolution data, and few studies have attempted to relate albedo to other urban land cover characteristics. This study provides an empirical description of urban summertime albedo using 30 m remote sensing measurements in the metropolitan area around Boston, Massachusetts, relating albedo to metrics of impervious cover fraction, tree canopy coverage, population density, and land surface temperature (LST). At 30 m spatial resolution, median albedo over the study area (excluding open water) was 0.152 (0.112-0.187). Trends of lower albedo with increasing urbanization metrics and temperature emerged only after aggregating data to 500 m or the boundaries of individual towns, at which scale a -0.01 change in albedo was associated with a 29 (25-35)% decrease in canopy cover, a 27 (24-30)% increase in impervious cover, and an increase in population from 11 to 386 km-2. The most intensively urbanized towns in the region showed albedo up to 0.035 lower than the least urbanized towns, and mean mid-morning LST 12.6°C higher. Trends in albedo derived from 500 m Moderate Resolution Imaging Spectroradiometer (MODIS) measurements were comparable, but indicated a strong contribution of open water at this coarser resolution. These results reveal linkages between albedo and urban land cover character, and offer empirical context for climate resilient planning and future landscape functional changes with urbanization.

Public health, the APHA, and urban renewal.

PubMed

Lopez, Russ P

2009-09-01

Joint efforts by fields of public health in the last decade have advocated use of the built environment to protect health. Past involvement by public health advocates in urban policy, however, has had mixed results. Although public health has significantly contributed to health improvements, its participation in urban renewal activities was problematic. Health advocates and the American Public Health Association produced guidelines that were widely used to declare inner-city areas blighted and provided a scientific justification for demolishing neighborhoods and displacing mostly poor and minority people. Furthermore, health departments failed to uphold their legal responsibility to ensure that relocated families received safe, affordable housing alternatives. These failures have important implications for future health-related work on the built environment and other core public health activities.

Public Health, the APHA, and Urban Renewal

PubMed Central

2009-01-01

Joint efforts by fields of public health in the last decade have advocated use of the built environment to protect health. Past involvement by public health advocates in urban policy, however, has had mixed results. Although public health has significantly contributed to health improvements, its participation in urban renewal activities was problematic. Health advocates and the American Public Health Association produced guidelines that were widely used to declare inner-city areas blighted and provided a scientific justification for demolishing neighborhoods and displacing mostly poor and minority people. Furthermore, health departments failed to uphold their legal responsibility to ensure that relocated families received safe, affordable housing alternatives. These failures have important implications for future health-related work on the built environment and other core public health activities. PMID:19608955

The Spatial Variations and Hotspots of Ecosystem Service Values in India During 1985 - 2005

NASA Astrophysics Data System (ADS)

Sannigrahi, S.; Bhatt, S.; Paul, S. K.; Sen, S.; Rahmat, S.; Uniyal, B.

2017-12-01

Ecosystem services can be defined as the processes and functions of the natural ecosystem through which the basic needs and demands of human well-being are sustained and fulfilled. In this study, the spatiotemporal variation and clusters of ESV are analyzed during 1985 - 2005 using benefits transfer approach. The spatial heterogeneity of ESV was assessed through Local Morans I, Getis-Ord-Gi hotspot, and Geary's I statistics, respectively. The temporal uncertainty of ESV was estimated through Ecosystem Service Change Index (ESCI), Ecosystem Service Status Index (ESSI). The sensitivity of ESV to land use/land cover changes were estimated using the Coefficient of Elasticity (CE) approach. The variability of ESV in different land-use categories was examined through Coefficient of Variation (CV), Theil Index (TI), Ginni Coefficient and Entropy method. The contribution of ESV to GDP was quantified using the percent of ESV (%ESV) approach. Total eight ecoregions were considered for estimating the changing dynamics of high and low ESV clusters during 1985 - 2005. Among the eight ecoregions, grassland shows the minimum CV of ESV (1.15) during 1985 - 2005, indicating the most stable and undisturbed eco-regions in India during this study period, followed by cropland (CV= 2.0), forest land (2.32), water bodies (3.27), mangrove (3.5) respectively. While, the urban built-up (CV = 15.89) and wetland (CV = 10.91) exhibits the highest CV during 1985 - 2005. The ESCI was found highly negative (-0.05) over forested region, and negative (-0.02) for water bodies, while a very highly positive (0.38), highly positive (0.24), moderate positive (0.06), weakly positive (0.03) and very weak positive (0.02) values have quantified for urban built-up, wetland, mangrove, cropland and, grassland, respectively. The overall ESSI was very good for urban built-up categories (0.24), followed by wetland (0.15), mangrove (0.04), cropland (0.02) and, grassland (0.01), respectively. During this period (1985 - 2005), the changes of ESV were found statistically significant for urban built-up (t = 10.90, P = 0.008), and wetland (t = 15.88, P = 0.004), while the changes were insignificant for rest of the ecoregions.

District-level local measuring program of the urban environment in Budapest

NASA Astrophysics Data System (ADS)

Dian, Csenge; Pongrácz, Rita; Dezsö, Zsuzsanna; Bartholy, Judit

2016-04-01

The natural environment and thus, the climatic conditions are modified by the concentrated human presence of urban areas. In our research we aim to analyze the resulting urban climatic effects in a downtown district of Budapest, Hungary. For this purpose, we have started a measuring program of in-situ measurements in the southern central located district called Ferencváros, which can be found near the river Danube, and mainly consists of 3- and 4-storey older and newly built buildings. The newly built buildings are mainly the results of the Ferencváros local government's efforts to improve the environment for the citizens. Within the framework of the block rehabilitation program, inner parts of the old house blocks were demolished, and inside the blocks common green areas have been created. In our urban climate measurement program air temperature and relative humidity are recorded along a pre-defined path consisting of 22 measuring points, which covers the studied area. The measuring sites are located in different characteristical points of the district, such as green parks, narrow streets, paved squares and roads. In order to calculate the urban heat island intensity, temperature measurements are compared to the hourly recorded data of the Budapest synoptic station (ID number: 12843) located in the southeastern suburb district of the city. After completing an entire year of measurements, the seasonal cycle of temperature and relative humidity differences are analyzed as well, as the diurnal changes and the spatial structure within the study area.

New Energy Efficient Housing Has Reduced Carbon Footprints in Outer but Not in Inner Urban Areas.

PubMed

Ottelin, Juudit; Heinonen, Jukka; Junnila, Seppo

2015-08-18

Avoiding urban sprawl and increasing density are often considered as effective means to mitigate climate change through urban planning. However, there have been rapid technological changes in the fields of housing energy and private driving, and the development is continuing. In this study, we analyze the carbon footprints of the residents living in new housing in different urban forms in Finland. We compare the new housing to existing housing stock. In all areas, the emissions from housing energy were significantly lower in new buildings. However, in the inner urban areas the high level of consumption, mostly due to higher affluence, reverse the gains of energy efficient new housing. The smallest carbon footprints were found in newly built outer and peri-urban areas, also when income level differences were taken into account. Rather than strengthening the juxtaposition of urban and suburban areas, we suggest that it would be smarter to recognize the strengths and weaknesses of both modes of living and develop a more systemic strategy that would result in greater sustainability in both areas. Since such strategy does not exist yet, it should be researched and practically developed. It would be beneficial to focus on area specific mitigation measures.

Commuting Mode Choice in a High-Density City: Do Land-Use Density and Diversity Matter in Hong Kong?

PubMed Central

Sun, Guibo; Sarkar, Chinmoy; Xiao, Yang

2018-01-01

Hong Kong is a densely populated and transit-oriented Chinese city, which provides an ideal urban environment with which to study the various successful facets of land use policy as a model for potential replication to curb increasing car use in other Chinese cities. We examine the commuting mode choice of 203,900 households living in 4768 street blocks in Hong Kong from 2011 census. A street block is the smallest planning unit, made up of one or more housing estates with a homogenous built environment and socioeconomic status. The built environment is measured using the five Ds framework, an international dimensioning framework for classifying and measuring attributes of the built environment for physical activity and travel behaviors. Generalized, multi-level mixed models were applied to detect the associations between travel choice and built environment characteristics, while adjusting for socioeconomic status. Design and destination accessibility had greater effects on the choices to walk and take public transport than on the choice to drive. Density and diversity had only marginal effects on mode choice. Unexpectedly, distance to the urban center had the opposite effect on automobile use to that found in Western studies. Hong Kong residents living close to the urban center were more likely to drive for commuting trips. The contrasting findings between our study and Western studies suggest that the associations between a high-density built environment and travel choice vary with urban context. PMID:29734721

[Urban and population development of the city of Puebla and its metropolitan area].

PubMed

Barbosa Prieto, A

1991-12-01

Metropolitanization has been considered an important problem of regional development in developing countries. Attitudes toward the metropolis have been ambivalent in Latin America. On the 1 hand the metropolis is viewed as an obstacle to development that absorbs resources from the zone of influence and incurs high social costs of urbanization, but on the hand it is also viewed as a form of achieving levels of economic efficiency comparable to those of developed countries. Metropolitan areas should not be viewed as isolated, but rather as important points of demographic and manpower attraction, poles of economic growth and technological and cultural innovation. "Urban areas" and "metropolitan zones" are distinct ways of defining and delimiting urban phenomena. Although there is no consensus as to the exact definitions of these 2 urban units, it is generally accepted that the urban area is the city itself as well as the contiguous built up area reaching in all directions to the onset of nonurban land uses such as forests territorial extension that includes the politico-administrative units with urban characteristics such as work places and residences for nonagricultural workers, and that maintain constant and intense socioeconomic interrelations with the central city. The process of urban planning in the metropolitan zone of Puebla, Mexico, began in institutional form in 1980 with master plans for the population centers of Puebla, Amozoc, San Andres and San Pedro Cholula, and Zacatelco in the state of Tlaxcala. In 1987., an attempt was made by the governments of the states of Puebla and Tlaxcala to develop a plan for the metropolitan zone as a single unit. Population growth was greater within the city of Puebla than in the metropolitan zone from 1960-80, but after 1980 growth in the outlying areas exceeded that in the center city. The population density of the city of Puebla declined from 160/hectare in 1950 to 76/hectare in 1990, the result of progressive dispersion of the population to surrounding municipios. Planning for the city of Puebla must metropolitan zone.

Urban expansion of major cities in the US Great Plains from 2000 to 2009 using scatterometer data

NASA Astrophysics Data System (ADS)

Nguyen, L. H.; Nghiem, S. V.; Henebry, G. M.

2015-12-01

A long-term metric of urban landscape changes provide valuable information for many fundamental studies and applications. Here we studied expansion of the nine largest metropolitan statistical areas (MSA) in the Great Plains from 2000 to 2009 period using QuikSCAT backscatter data processed with the Dense Sampling Method (DSM). A 5x5 Gaussian Kernel Smoothing (with sigma=1) was applied to reduce noise in DSM backscatter images, which have a nominal spatial posting of 1 km. The outputs were then converted into vector files and coupled with the percent impervious surface area (ISA) data from the 2001 and 2011 National Land Cover Datasets to show changes in urban extent using two independent sources. The results demonstrate the capability of DSM scatterometer data to delineate urban extent and change. For instance, the Dallas - Fort Worth (DFW) MSA was separated into three sub-regions based on backscatter (cf. figure). The urban core area is identified by large commercial and industrial structures correspond to a high backscatter center greater than -6 dB. The urban built-up area consisting of smaller buildings falls within the -6 dB and -8 dB contours. Backscatter of the urban edge, where residential and other land uses are mixed, falls within the -8 dB and -10 dB contours. From 2000 to 2009, total urban area in DFW increased from 3484 to 5066 square kilometers, according to the filtered scatterometer data. The change in ISA between 2001 and 2011 within the -8 to -10 dB contour was 101 square kilometers, of which 73% occurred in the northern half of the DFW MSA. The Mann-Kendall trend test applied to the area time series indicates expanding spatial trends in every sub-region. Most changes occurred along the northern suburban edge. The distance between the 2000 and 2009 -10 dB contours ranged from 1.5 to 14.6 km with an average of 6 km and a coefficient of variation of 48%. We will present results for the other eight MSA from Houston, TX to Des Moines, IA.

Decentralized Sensor Fusion for Ubiquitous Networking Robotics in Urban Areas

PubMed Central

Sanfeliu, Alberto; Andrade-Cetto, Juan; Barbosa, Marco; Bowden, Richard; Capitán, Jesús; Corominas, Andreu; Gilbert, Andrew; Illingworth, John; Merino, Luis; Mirats, Josep M.; Moreno, Plínio; Ollero, Aníbal; Sequeira, João; Spaan, Matthijs T.J.

2010-01-01

In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted. PMID:22294927

The built environment and alcohol consumption in urban neighborhoods.

PubMed

Bernstein, Kyle T; Galea, Sandro; Ahern, Jennifer; Tracy, Melissa; Vlahov, David

2007-12-01

To examine the relations between characteristics of the neighborhood built environment and recent alcohol use. We recruited participants through a random digit dial telephone survey of New York City (NYC) residents. Alcohol consumption was assessed using a structured interview. All respondents were assigned to neighborhood of residence. Data on the internal and external built environment in 59 NYC neighborhoods were collected from archival sources. Multilevel models were used to assess the adjusted relations between features of the built environment and alcohol use. Of the 1355 respondents, 40% reported any alcohol consumption in the past 30 days, and 3% reported more than five drinks in one sitting (heavy drinking) in the past 30 days. Few characteristics of the built environment were associated with any alcohol use in the past 30 days. However, several features of the internal and external built environment were associated with recent heavy drinking. After adjustment, persons living in neighborhoods characterized by poorer features of the built environment were up to 150% more likely to report heavy drinking in the last 30 days compared to persons living in neighborhoods characterized by a better built environment. Quality of the neighborhood built environment may be associated with heavy alcohol consumption in urban populations, independent of individual characteristics. The role of the residential environment as a determinant of alcohol abuse warrants further examination.

Built-up Areas Extraction in High Resolution SAR Imagery based on the method of Multiple Feature Weighted Fusion

NASA Astrophysics Data System (ADS)

Liu, X.; Zhang, J. X.; Zhao, Z.; Ma, A. D.

2015-06-01

Synthetic aperture radar in the application of remote sensing technology is becoming more and more widely because of its all-time and all-weather operation, feature extraction research in high resolution SAR image has become a hot topic of concern. In particular, with the continuous improvement of airborne SAR image resolution, image texture information become more abundant. It's of great significance to classification and extraction. In this paper, a novel method for built-up areas extraction using both statistical and structural features is proposed according to the built-up texture features. First of all, statistical texture features and structural features are respectively extracted by classical method of gray level co-occurrence matrix and method of variogram function, and the direction information is considered in this process. Next, feature weights are calculated innovatively according to the Bhattacharyya distance. Then, all features are weighted fusion. At last, the fused image is classified with K-means classification method and the built-up areas are extracted after post classification process. The proposed method has been tested by domestic airborne P band polarization SAR images, at the same time, two groups of experiments based on the method of statistical texture and the method of structural texture were carried out respectively. On the basis of qualitative analysis, quantitative analysis based on the built-up area selected artificially is enforced, in the relatively simple experimentation area, detection rate is more than 90%, in the relatively complex experimentation area, detection rate is also higher than the other two methods. In the study-area, the results show that this method can effectively and accurately extract built-up areas in high resolution airborne SAR imagery.

Rainfall estimation using microwave links. Results from an experimental setup in Luxembourg

NASA Astrophysics Data System (ADS)

Fenicia, Fabrizio; Matgen, Patrick; Pfister, Laurent

2010-05-01

Microwave links represent a valid alternative to traditional rainfall estimation methods. They are commonly used in mobile phone communication, and they constitute built-in widely distributed networks. Due to their ability of providing high temporal and spatial resolution measurements, their use is particularly suitable in urban settings. We here show results from an experimental setup in Luxembourg City, where two dual frequency links have been installed. The links cover a distance of about 4km, and measure power attenuation at 1 min. timestep. The links have been equipped with several recording raingauges, which measure rainfall in real-time communicating through a wireless connection. This set-up has been used to analyze in detail the mapping between attenuation and rainfall intensity, and gain insights into the potential accuracy of these instruments. In addition, we investigated the relation between rainfall and discharge response of the urban area of Luxembourg, which shows the potential utility of high frequency rainfall measurements for urban environments.

Bird diversity and distribution in relation to urban landscape types in northern Rwanda.

PubMed

Gatesire, T; Nsabimana, D; Nyiramana, A; Seburanga, J L; Mirville, M O

2014-01-01

Using the point count method, linear mixed models, Shannon's diversity index, and Bray-Curtis cluster analysis, we conducted a study of the effect of urban fabric layout on bird diversity and distribution in northern Rwanda. The results showed a significant effect of city landscapes on bird richness and relative abundance; residential neighborhoods, institutional grounds, and informal settlements had the highest species diversity in comparison to other microlandscape types. Riversides were characterized by specialized bird species, commonly known to be restricted to wetland environments. Built-up areas and open field landscapes had comparable results. One Albertine Rift endemic bird species, the Ruwenzori Double-collared Sunbird (Cinnyris stuhlmanni), was recorded. Three migratory birds were found in Musanze city for the first time: the Common Sandpiper (Actitis hypoleucos), the Spotted Flycatcher (Muscicapa striata), and the Willow Warbler (Phylloscopus trochilus). Two bird species have not been previously reported in Rwanda: the Garden Warbler (Sylvia borin) and the Lesser Spotted Eagle (Aquila pomarina). The implications of this study are particularly relevant to urban decision makers who should consider the existence of a great diversity of avian fauna when developing and implementing master plans, especially when villages and cities are in proximity of protected areas or natural reserves.

Effects of income and urban form on urban NO2: global evidence from satellites.

PubMed

Bechle, Matthew J; Millet, Dylan B; Marshall, Julian D

2011-06-01

Urban air pollution is among the top 15 causes of death and disease worldwide, and a problem of growing importance with a majority of the global population living in cities. A important question for sustainable development is to what extent urban design can improve or degrade the environment and public health. We investigate relationships between satellite-derived estimates of nitrogen dioxide concentration (NO(2), a key component of urban air pollution) and urban form for 83 cities globally. We find a parsimonious yet powerful relationship (model R(2) = 0.63), using as predictors population, income, urban contiguity, and meteorology. Cities with highly contiguous built-up areas have, on average, lower urban NO(2) concentrations (a one standard deviation increase in contiguity is associated with a 24% decrease in average NO(2) concentration). More-populous cities tend to have worse air quality, but the increase in NO(2) associated with a population increase of 10% may be offset by a moderate increase (4%) in urban contiguity. Urban circularity ("compactness") is not a statistically significant predictor of NO(2) concentration. Although many factors contribute to urban air pollution, our findings suggest that antileapfrogging policies may improve air quality. We find that urban NO(2) levels vary nonlinearly with income (Gross Domestic Product), following an "environmental Kuznets curve"; we estimate that if high-income countries followed urban pollution-per-income trends observed for low-income countries, NO(2) concentrations in high-income cities would be ∼10× larger than observed levels.

Mapping deforestation and urban expansion in Freetown, Sierra Leone, from pre- to post-war economic recovery.

PubMed

Mansaray, Lamin R; Huang, Jingfeng; Kamara, Alimamy A

2016-08-01

Freetown, the capital of Sierra Leone has experienced vast land-cover changes over the past three decades. In Sierra Leone, however, availability of updated land-cover data is still a problem even for environmental managers. This study was therefore, conducted to provide up-to-date land-cover data for Freetown. Multi-temporal Landsat data at 1986, 2001, and 2015 were obtained, and a maximum likelihood supervised classification was employed. Eight land-cover classes or categories were recognized as follows: water, wetland, built-up, dense forest, sparse forest, grassland, barren, and mangrove. Land-cover changes were mapped via post-classification change detection. The persistence, gain, and loss of each land-cover class, and selected land conversions were also quantified. An overall classification accuracy of 87.3 % and a Kappa statistic of 0.85 were obtained for the 2015 map. From 1986 to 2015, water, built-up, grassland, and barren had net gains, whereas forests, wetlands, and mangrove had net loses. Conversion analyses among forests, grassland, and built-up show that built-up had targeted grassland and avoided forests. This study also revealed that, the overall land-cover change at 2001-2015 was higher (28.5 %) than that recorded at 1986-2001 (20.9 %). This is attributable to the population increase in Freetown and the high economic growth and infrastructural development recorded countrywide after the civil war. In view of the rapid land-cover change and its associated environmental impacts, this study recommends the enactment of policies that would strike a balance between urbanization and environmental sustainability in Freetown.

Exposure of coastal built assets in the South Pacific to climate risks

NASA Astrophysics Data System (ADS)

Kumar, Lalit; Taylor, Subhashni

2015-11-01

Pacific island countries (PICs) are situated in a highly dynamic ocean-atmosphere interface, are dispersed over a large ocean area, and have highly populated urban centres located on the coastal margin. The built infrastructure associated with urban centres is also located within close proximity to the coastlines, exposing such infrastructure to a variety of natural and climate change-related hazards. In this research we undertake a comprehensive analysis of the exposure of built infrastructure assets to climate risk for 12 PICs. We show that 57% of the assessed built infrastructure for the 12 PICs is located within 500 m of their coastlines, amounting to a total replacement value of US$21.9 billion. Eight of the 12 PICs have 50% or more of their built infrastructure located within 500 m of their coastlines. In particular, Kiribati, Marshall Islands and Tuvalu have over 95% of their built infrastructure located within 500 m of their coastlines. Coastal adaptation costs will require substantial financial resources, which may not be available in developing countries such as the PICs, leaving them to face very high impacts but lacking the adaptive capacity.

Fine-Scale Population Estimation by 3D Reconstruction of Urban Residential Buildings

PubMed Central

Wang, Shixin; Tian, Ye; Zhou, Yi; Liu, Wenliang; Lin, Chenxi

2016-01-01

Fine-scale population estimation is essential in emergency response and epidemiological applications as well as urban planning and management. However, representing populations in heterogeneous urban regions with a finer resolution is a challenge. This study aims to obtain fine-scale population distribution based on 3D reconstruction of urban residential buildings with morphological operations using optical high-resolution (HR) images from the Chinese No. 3 Resources Satellite (ZY-3). Specifically, the research area was first divided into three categories when dasymetric mapping was taken into consideration. The results demonstrate that the morphological building index (MBI) yielded better results than built-up presence index (PanTex) in building detection, and the morphological shadow index (MSI) outperformed color invariant indices (CIIT) in shadow extraction and height retrieval. Building extraction and height retrieval were then combined to reconstruct 3D models and to estimate population. Final results show that this approach is effective in fine-scale population estimation, with a mean relative error of 16.46% and an overall Relative Total Absolute Error (RATE) of 0.158. This study gives significant insights into fine-scale population estimation in complicated urban landscapes, when detailed 3D information of buildings is unavailable. PMID:27775670

Vegetation growth enhancement in urban environments of the Conterminous United States.

PubMed

Jia, Wenxiao; Zhao, Shuqing; Liu, Shuguang

2018-05-19

Cities are natural laboratories for studying vegetation responses to global environmental changes because of their climate, atmospheric, and biogeochemical conditions. However, few holistic studies have been conducted on the impact of urbanization on vegetation growth. We decomposed the overall impacts of urbanization on vegetation growth into direct (replacement of original land surfaces by impervious built-up) and indirect (urban environments) components, using a conceptual framework and remotely-sensed data for 377 metropolitan statistical areas (MSAs) in the conterminous United States (CONUS) in 2001, 2006, and 2011. Results showed that urban pixels are often greener than expected given the amount of paved surface they contain. The vegetation growth enhancement due to indirect effects occurred in 88.4%, 90.8% and 92.9% of urban bins in 2001, 2006 and 2011, respectively. By defining offset value as the ratio of the absolute indirect and direct impact, we obtained that growth enhancement due to indirect effects compensated for about 29.2%, 29.5% and 31.0% of the reduced productivity due to loss of vegetated surface area on average in 2001, 2006, and 2011, respectively. Vegetation growth responses to urbanization showed little temporal variation but large regional differences with higher offset value in the western CONUS than in the eastern CONUS. Our study highlights the prevalence of vegetation growth enhancement in urban environments and the necessity of differentiating various impacts of urbanization on vegetation growth, and calls for tailored field experiments to understand the relative contributions of various driving forces to vegetation growth and predict vegetation responses to future global change using cities as harbingers. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Understanding of urban hazards, fire, and tsunamis

USGS Publications Warehouse

Hays, Walter W.; ,

1997-01-01

Understanding of the causes and solutions of an urban area's (e.g., Los Angeles, San Diego, San Francisco, Oakland, Seattle, Portland, Anchorage, Salt Lake City, Memphis, St. Louis, Charleston, Boston, San Juan) vulnerability to earthquakes, fire, and tsunamis has increased significantly during the past 50 years, and during the current International Decade for Natural Disaster Reduction (IDNDR). Vulnerability is caused by flaws in planning, siting, design, construction, and use. It is fundamentally dependent upon the hazard, built, and policy environments of the urban area. Reduction of vulnerability is directly related to the decision-making process that calls for the adoption and enforcement of risk management programs (e.g., mitigation, preparedness, emergency response, and recovery measures) that are designed to make the urban area resilient to earthquakes, fires, and, as appropriate, tsunamis.

Consolidating Data of Global Urban Populations: a Comparative Approach

NASA Astrophysics Data System (ADS)

Blankespoor, B.; Khan, A.; Selod, H.

2017-12-01

Global data on city populations are essential for the study of urbanization, city growth and the spatial distribution of human settlements. Such data are either gathered by combining official estimates of urban populations from across countries or extracted from gridded population models that combine these estimates with geospatial data. These data sources provide varying estimates of urban populations and each approach has its advantages and limitations. In particular, official figures suffer from a lack of consistency in defining urban units (across both space and time) and often provide data for jurisdictions rather than the functionally meaningful urban area. On the other hand, gridded population models require a user-imposed definition to identify urban areas and are constrained by the modelling techniques and input data employed. To address these drawbacks, we combine these approaches by consolidating information from three established sources: (i) the Citypopulation.de (Brinkhoff, 2016); (ii) the World Urban Prospects data (United Nations, 2014); and (iii) the Global Human Settlements population grid (GHS-POP) (EC - JRC, 2015). We create urban footprints with GHS-POP and spatially merge georeferenced city points from both UN WUP and Citypopulation.de with these urban footprints to identify city points that belong to a single agglomeration. We create a consolidated dataset by combining population data from the UN WUP and Citypopulation.de. The flexible framework outlined can incorporate information from alternative inputs to identify urban clusters e.g. by using night-time lights, built-up area or alternative gridded population models (e.g WorldPop or Landscan) and the parameters employed (e.g. density thresholds for urban footprints) may also be adjusted, e.g., as a function of city-specific characteristics. Our consolidated dataset provides a wider and more accurate coverage of city populations to support studies of urbanization. We apply the data to re-examine Zipf's Law. Brinkhoff, Thomas. 2016. City Population.EC - JRC; Columbia University, CIESIN. 2015. GHS population grid, derived from GPW4, multi-temporal (1975, 1990, 2000, 2015).United Nations, Department of Economic and Social Affairs, Population Division. 2014. World Urbanization Prospects: 2014 Revision.

Effects of Land Use/Cover Changes and Urban Forest Configuration on Urban Heat Islands in a Loess Hilly Region: Case Study Based on Yan'an City, China.

PubMed

Zhang, Xinping; Wang, Dexiang; Hao, Hongke; Zhang, Fangfang; Hu, Youning

2017-07-26

In this study Yan'an City, a typical hilly valley city, was considered as the study area in order to explain the relationships between the surface urban heat island (SUHI) and land use/land cover (LULC) types, the landscape pattern metrics of LULC types and land surface temperature (LST) and remote sensing indexes were retrieved from Landsat data during 1990-2015, and to find factors contributed to the green space cool island intensity (GSCI) through field measurements of 34 green spaces. The results showed that during 1990-2015, because of local anthropogenic activities, SUHI was mainly located in lower vegetation cover areas. There was a significant suburban-urban gradient in the average LST, as well as its heterogeneity and fluctuations. Six landscape metrics comprising the fractal dimension index, percentage of landscape, aggregation index, division index, Shannon's diversity index, and expansion intensity of the classified LST spatiotemporal changes were paralleled to LULC changes, especially for construction land, during the past 25 years. In the urban area, an index-based built-up index was the key positive factor for explaining LST increases, whereas the normalized difference vegetation index and modified normalized difference water index were crucial factors for explaining LST decreases during the study periods. In terms of the heat mitigation performance of green spaces, mixed forest was better than pure forest, and the urban forest configuration had positive effects on GSCI. The results of this study provide insights into the importance of species choice and the spatial design of green spaces for cooling the environment.

Effects of Land Use/Cover Changes and Urban Forest Configuration on Urban Heat Islands in a Loess Hilly Region: Case Study Based on Yan’an City, China

PubMed Central

Zhang, Xinping; Hao, Hongke; Zhang, Fangfang; Hu, Youning

2017-01-01

In this study Yan’an City, a typical hilly valley city, was considered as the study area in order to explain the relationships between the surface urban heat island (SUHI) and land use/land cover (LULC) types, the landscape pattern metrics of LULC types and land surface temperature (LST) and remote sensing indexes were retrieved from Landsat data during 1990–2015, and to find factors contributed to the green space cool island intensity (GSCI) through field measurements of 34 green spaces. The results showed that during 1990–2015, because of local anthropogenic activities, SUHI was mainly located in lower vegetation cover areas. There was a significant suburban-urban gradient in the average LST, as well as its heterogeneity and fluctuations. Six landscape metrics comprising the fractal dimension index, percentage of landscape, aggregation index, division index, Shannon’s diversity index, and expansion intensity of the classified LST spatiotemporal changes were paralleled to LULC changes, especially for construction land, during the past 25 years. In the urban area, an index-based built-up index was the key positive factor for explaining LST increases, whereas the normalized difference vegetation index and modified normalized difference water index were crucial factors for explaining LST decreases during the study periods. In terms of the heat mitigation performance of green spaces, mixed forest was better than pure forest, and the urban forest configuration had positive effects on GSCI. The results of this study provide insights into the importance of species choice and the spatial design of green spaces for cooling the environment. PMID:28933770

SIRANERISK: Modelling dispersion of steady and unsteady pollutant releases in the urban canopy

NASA Astrophysics Data System (ADS)

Soulhac, L.; Lamaison, G.; Cierco, F.-X.; Ben Salem, N.; Salizzoni, P.; Mejean, P.; Armand, P.; Patryl, L.

2016-09-01

SIRANERISK is an operational model for the simulation of the dispersion of unsteady atmospheric releases of pollutant within and above an urban area. SIRANERISK is built on the same principles as the SIRANE model, and couples a street network model for the pollutant transfers within the urban canopy with a Gaussian puff model for the transfers above it. The performance of the model are here analysed by a detailed comparisons with wind-tunnel experiments. These experiments concern the dispersion of steady and unsteady pollutant releases within and above obstacle arrays with varying geometrical configurations, representing different topologies of idealised urban districts. The overall good agreement between numerical and experimental data demonstrates the reliability of SIRANERISK as an operational tool for the assessment of risk analysis and for the management of crises due to the accidental release of harmful airborne pollutants within a built environment.

Application of GIS to modified models of vehicle emission dispersion

NASA Astrophysics Data System (ADS)

Jin, Taosheng; Fu, Lixin

This paper reports on a preliminary study of the forecast and evaluation of transport-related air pollution dispersion in urban areas. Some modifications of the traditional Gauss dispersion models are provided, and especially a crossroad model is built, which considers the great variation of vehicle emission attributed to different driving patterns at the crossroad. The above models are combined with a self-developed geographic information system (GIS) platform, and a simulative system with graphical interfaces is built. The system aims at visually describing the influences on the urban environment by urban traffic characteristics and therefore gives a reference to the improvement of urban air quality. Due to the introduction of a self-developed GIS platform and a creative crossroad model, the system is more effective, flexible and accurate. Finally, a comparison of the simulated (predicted) and observed hourly concentration is given, which indicates a good simulation.

Flux and turbulence measurements at a densely built-up site in Marseille: Heat, mass (water and carbon dioxide), and momentum

NASA Astrophysics Data System (ADS)

Grimmond, C. S. B.; Salmond, J. A.; Oke, T. R.; Offerle, B.; Lemonsu, A.

2004-12-01

Eddy covariance (EC) observations above the densely built-up center of Marseille during the Expérience sur site pour contraindre les modèles de pollution atmosphérique et de transport d'émissions (ESCOMPTE) summertime measurement campaign extend current understanding of surface atmosphere exchanges in cities. The instrument array presented opportunities to address issues of the representativeness of local-scale fluxes in urban settings. Separate EC systems operated at two levels, and a telescoping tower allowed the pair to be exposed at two different sets of heights. The flux and turbulence observations taken at the four heights, stratified by wind conditions (mistral wind and sea breeze), are used to address the partitioning of the surface energy balance in an area with large roughness elements. The turbulent sensible heat flux dominates in the daytime, although the storage heat flux is a significant term that peaks before solar noon. The turbulent latent heat flux is small but not negligible. Carbon dioxide fluxes show that this central city district is almost always a source, but the vegetation reduces the magnitude of the fluxes in the afternoon. The atmosphere in such a heavily developed area is rarely stable. The turbulence characteristics support the empirical functions proposed by M. Roth.

The relationship between urban form and air pollution depends on seasonality and city size.

PubMed

Liu, Yupeng; Wu, Jianguo; Yu, Deyong; Ma, Qun

2018-06-01

Understanding how urban form is related to air pollution is important to urban planning and sustainability, but the urban form-air pollution relationship is currently muddled by inconsistent findings. In this study, we investigated how the compositional and configurational attributes of urban form were related to different air pollution measures (PM 2.5 , API, and exceedance) in 83 Chinese cities, with explicit consideration of city size and seasonality. Ten landscape metrics were selected to quantify urban form attributes, and Spearman's correlation was used to quantify the urban form-air pollution relationship. Our results show that the urban form and air pollution relationship was dominated by city size and moderated by seasonality. Specifically, urban air pollution levels increased consistently and substantially from small to medium, large, and megacities. The urban form-air pollution relationship depended greatly on seasonality and monsoons. That is, the relationship was more pronounced in spring and summer than fall and winter, as well as in cities affected by monsoons. Urban air pollution was correlated more strongly with landscape composition metrics than landscape configuration metrics which seemed to affect only PM 2.5 concentrations. Our study suggests that, to understand how air pollution levels are related to urban form, city size and seasonality must be explicitly considered (or controlled). Also, in order to mitigate urban air pollution problems, regional urban planning is needed to curb the spatial extent of built-up areas, reduce the degree of urban fragmentation, and increase urban compactness and contiguity, especially for large and megacities.

Practical issues for using solar-reflective materials to mitigate urban heat islands

NASA Astrophysics Data System (ADS)

Bretz, Sarah; Akbari, Hashem; Rosenfeld, Arthur

Solar-reflective or high-albedo, alternatives to traditionally absorptive urban surfaces such as rooftops and roadways can reduce cooling energy use and improve urban air quality at almost no cost. This paper presents information to support programs that mitigate urban heat islands with solar-reflective surfaces: estimates of the achievable increase in albedo for a variety of surfaces, issues related to the selection of materials and costs and benefits of using them. As an example, we present data for Sacramento, California. In Sacramento, we estimate that 20% of the 96 square mile area is dark roofing and 10% is dark pavement. Based on the change in albedo that is achievable for these surfaces, the overall albedo of Sacramento could be increased by 18%, a change that would produce significant energy savings and increase comfort within the city. Roofing market data indicate which roofing materials should be targeted for incentive programs. In 1995, asphalt shingle was used for over 65% of residential roofing area in the U.S. and 6% of commercial. Built-up roofing was used for about 5% of residential roofing and about 30% of commercial roofing. Single-ply membranes covered about 9% of the residential roofing area and over 30% of the commercial area. White, solar-reflective alternatives are presently available for these roofing materials but a low- first-cost, solar-reflective alternative to asphalt shingles is needed to capture the sloped-roof market. Since incoming solar radiation has a large non-visible component, solar-reflective materials can also be produced in a variety of colors.

Quantify landslide exposure in areas with limited hazard information

NASA Astrophysics Data System (ADS)

Pellicani, R.; Spilotro, G.; Van Westen, C. J.

2012-04-01

In Daunia region, located in the North-western part of Apulia (Southern Italy), landslides are the main source of damage to properties in the urban centers of the area, involving especially transportation system and the foundation stability of buildings. In the last 50 years, the growing demand for physical development of these unstable minor hillside and mountain centers has produced a very rapid expansion of built-up areas, often with poor planning of urban and territorial infrastructures, and invasion of the agricultural soil. Because of the expansion of the built-up towards not safe areas, human activities such as deforestation or excavation of slopes for road cuts and building sites, etc., have become important triggers for landslide occurrence. In the study area, the probability of occurrence of landslides is very difficult to predict, as well as the expected magnitude of events, due to the limited data availability on past landslide activity. Because the main limitations concern the availability of temporal data on landslides and triggering events (frequency), run-out distance and landslide magnitude, it was not possible to produce a reliable landslide hazard map and, consequently, a risk map. Given these limitations in data availability and details, a qualitative exposure map has been produced and combined with a landslide susceptibility map, both generated using a spatial multi-criteria evaluation (SMCE) procedure in a GIS system, for obtaining the qualitative landslide risk map. The qualitative analysis has been provided the spatial distribution of the exposure level in the study area; this information could be used in a preliminary stage of regional planning. In order to have a better definition of the risk level in the Daunia territory, the quantification of the economic losses at municipal level was carried out. For transforming these information on economic consequences into landslide risk quantification, it was necessary to assume the temporal probability of landslides, on the basis of the expert knowledge on the landslide phenomena. For each of twenty-five municipalities included in the study area, the expected losses (or consequences), in monetary terms, due to different hazard scenarios have been evaluated. After calculating the economic losses, the total risk at municipal level was evaluated, by generating the risk curves and calculating the area under the curves. The analysis of the risk curves related to the 25 municipalities has showed that the total risk values, expressed in monetary terms, is higher for the bigger municipal areas located in the southern part of the study area where the elevation is lower, as are more numerous the elements at risk distributed on the municipal territory. Finally, this quantitative risk assessment procedure, which calculates the exposure in monetary terms of elements at risk, allows to establish the changes in risk in future with urban development and monetary inflation.

Spatiotemporal Changes of Built-Up Land Expansion and Carbon Emissions Caused by the Chinese Construction Industry.

PubMed

Chuai, Xiaowei; Huang, Xianjin; Lu, Qinli; Zhang, Mei; Zhao, Rongqin; Lu, Junyu

2015-11-03

China is undergoing rapid urbanization, enlarging the construction industry, greatly expanding built-up land, and generating substantial carbon emissions. We calculated both the direct and indirect carbon emissions from energy consumption (anthropogenic emissions) in the construction sector and analyzed built-up land expansion and carbon storage losses from the terrestrial ecosystem. According to our study, the total anthropogenic carbon emissions from the construction sector increased from 3,905×10(4) to 103,721.17×10(4) t from 1995 to 2010, representing 27.87%-34.31% of the total carbon emissions from energy consumption in China. Indirect carbon emissions from other industrial sectors induced by the construction sector represented approximately 97% of the total anthropogenic carbon emissions of the sector. These emissions were mainly concentrated in seven upstream industry sectors. Based on our assumptions, built-up land expansion caused 3704.84×10(4) t of carbon storage loss from vegetation between 1995 and 2010. Cropland was the main built-up land expansion type across all regions. The study shows great regional differences. Coastal regions showed dramatic built-up land expansion, greater carbon storage losses from vegetation, and greater anthropogenic carbon emissions. These regional differences were the most obvious in East China followed by Midsouth China. These regions are under pressure for strong carbon emissions reduction.

Tephra fall clean-up in urban environments

NASA Astrophysics Data System (ADS)

Hayes, Josh L.; Wilson, Thomas M.; Magill, Christina

2015-10-01

Tephra falls impact urban communities by disrupting transport systems, contaminating and damaging buildings and infrastructures, and are potentially hazardous to human health. Therefore, prompt and effective tephra clean-up measures are an essential component of an urban community's response to tephra fall. This paper reviews case studies of tephra clean-up operations in urban environments around the world, spanning 50 years. It identifies methods used in tephra clean-up and assesses a range of empirical relationships between level of tephra accumulation and clean-up metrics such as collected tephra volume, costs, and duration of operations. Results indicate the volume of tephra collected from urban areas is proportional to tephra accumulation. Urban areas with small tephra accumulations (1,000 m3/km2 or an average of 1 mm thickness) may collect < 1% of the total deposit, whereas urban areas which experience large accumulations (> 50,000 m3/km2 or an average of 50 mm thickness) remove up to 80%. This relationship can inform impact and risk assessments by providing an estimate of the likely response required for a given tephra fall. No strong relationship was found between tephra fall accumulation and clean-up cost or duration for urban environments which received one-off tephra falls, suggesting that these aspects of tephra fall clean-up operations are context specific. Importantly, this study highlights the advantage of effective planning for tephra clean-up and disposal in potentially exposed areas.

Implication of relationship between natural impacts and land use/land cover (LULC) changes of urban area in Mongolia

NASA Astrophysics Data System (ADS)

Gantumur, Byambakhuu; Wu, Falin; Zhao, Yan; Vandansambuu, Battsengel; Dalaibaatar, Enkhjargal; Itiritiphan, Fareda; Shaimurat, Dauryenbyek

2017-10-01

Urban growth can profoundly alter the urban landscape structure, ecosystem processes, and local climates. Timely and accurate information on the status and trends of urban ecosystems is critical to develop strategies for sustainable development and to improve the urban residential environment and living quality. Ulaanbaatar city was urbanized very rapidly caused by herders and farmers, many of them migrating from rural places, have played a big role in this urban expansion (sprawl). Today, 1.3 million residents for about 40% of total population are living in the Ulaanbaatar region. Those human activities influenced stronger to green environments. Therefore, the aim of this study is determined to change detection of land use/land cover (LULC) and estimating their areas for the trend of future by remote sensing and statistical methods. The implications of analysis were provided by change detection methods of LULC, remote sensing spectral indices including normalized difference vegetation index (NDVI), normalized difference water index (NDWI) and normalized difference built-up index (NDBI). In addition, it can relate to urban heat island (UHI) provided by Land surface temperature (LST) with local climate issues. Statistical methods for image processing used to define relations between those spectral indices and change detection images and regression analysis for time series trend in future. Remote sensing data are used by Landsat (TM/ETM+/OLI) satellite images over the period between 1990 and 2016 by 5 years. The advantages of this study are very useful remote sensing approaches with statistical analysis and important to detecting changes of LULC. The experimental results show that the LULC changes can image on the present and after few years and determined relations between impacts of environmental conditions.

The Evaluation of GPS techniques for UAV-based Photogrammetry in Urban Area

NASA Astrophysics Data System (ADS)

Yeh, M. L.; Chou, Y. T.; Yang, L. S.

2016-06-01

The efficiency and high mobility of Unmanned Aerial Vehicle (UAV) made them essential to aerial photography assisted survey and mapping. Especially for urban land use and land cover, that they often changes, and need UAVs to obtain new terrain data and the new changes of land use. This study aims to collect image data and three dimensional ground control points in Taichung city area with Unmanned Aerial Vehicle (UAV), general camera and Real-Time Kinematic with positioning accuracy down to centimetre. The study area is an ecological park that has a low topography which support the city as a detention basin. A digital surface model was also built with Agisoft PhotoScan, and there will also be a high resolution orthophotos. There will be two conditions for this study, with or without ground control points and both were discussed and compared for the accuracy level of each of the digital surface models. According to check point deviation estimate, the model without ground control points has an average two-dimension error up to 40 centimeter, altitude error within one meter. The GCP-free RTK-airborne approach produces centimeter-level accuracy with excellent to low risk to the UAS operators. As in the case of the model with ground control points, the accuracy of x, y, z coordinates has gone up 54.62%, 49.07%, and 87.74%, and the accuracy of altitude has improved the most.

Contribution of urban farms to urban ecology of a developing city

NASA Astrophysics Data System (ADS)

Iswoyo, H.; Dariati, T.; Vale, B.; Bryant, M.

2018-05-01

Urban ecology has become a more popular concern as the awareness for mutual sharing between humans and other ecosystem members is increasing. This study aimed at assessing the value of urban farms in the city of Makassar, a fast-developing Indonesian city which according to its city council classification covered significant area of the city. The research employed Rapid Biodiversity Assessment (RBA) to assess quality of urban farms. The method assessed two important aspects of spaces in terms of ecology i.e. vegetation structures and vascular plants. Results showed the biodiversity of urban farms in Makassar compared to other typologies was high. Urban farms in Makassar in general have potential for ecological spots because despite they are more cultural than natural, their high plant biodiversity score, dominance of trees and less built areas make them always available for improvement to become more ecological spots.

Characterisation of Seasonal Temperature Variation in a Shallow, Urban Aquifer: Implications for the Sustainable Development of Ground Source Heating Systems

NASA Astrophysics Data System (ADS)

Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.

2017-04-01

Groundwater thermally enhanced by the Urban Heat Island effect can be utilised by ground source heating systems (GSHSs). However, the near subsurface is subject to seasonal temperature variation reflected in shallow groundwater that can differ by several degrees throughout the year. To sustainably manage the near surface thermal resource an understanding of factors which control variation in groundwater temperature and how these are transmitted through the aquifer is needed. We show that even in relatively small urban areas (Cardiff, U.K., situated on a shallow gravel aquifer) the Zone of Seasonal Fluctuation (ZSF) can vary in depth by 8m. GSHSs are more efficient if they are sited below the ZSF, where temperatures are more stable. In Spring 2014, 48 groundwater monitoring boreholes were profiled at a 1m resolution to measure groundwater temperature across Cardiff. These were reprofiled that Autumn and compared to the Spring temperatures, defining the ZSF. The average depth to the base of the ZSF was 9.5mbgl but ranged from 7.1-15.5mbgl. The amplitude of the differences between Spring and Autumn temperatures also varied. To better understand the high spatial variability 60 boreholes were instrumented with in situ temperature loggers, recording at half-hourly intervals. The first year's data revealed the amplitudes of temperature variation within boreholes with loggers at similar depths were not always consistent. It was also noted that lag times between air temperature and groundwater temperature were not uniform across the sites. The data also showed that where gravels occurred at shallower depths the ZSF tended to be shallower and lag times shorter. The wide spatial variability of the ZSF may be partially explained by differing landuse. Those boreholes in open, grassed areas showed a deeper ZSF than those in built-up areas but built-up areas generally showed the greatest variation between Spring and Autumn temperature profiles, suggesting heat loss from buildings and underground infrastructure plays a part. Natural and anthropogenic factors affecting spatial and temporal groundwater temperatures, either separately or in combination, that have been considered in this study include landuse, depth, lithology/lithostratigraphy, material properties, hydrogeological setting, thermal conductivity, buried infrastructure, land surface temperature, weather effects and solar radiation. This study shows that urban groundwater temperatures can vary greatly across a small area, which has implications for the successful development, and long-term performance of open- and closed-loop GSHSs, and the environmental regulation of these systems. Key to the effective wide-scale use of GSHSs is an understanding of the hydrogeological setting, chiefly how heat is transferred across the aquifer. This study attempts to provide insight into an array of factors which determine heat transfer in the ZSF.

The extent and intensity of the urban heat island in Iași city, Romania

NASA Astrophysics Data System (ADS)

Sfîcă, Lucian; Ichim, Pavel; Apostol, Liviu; Ursu, Adrian

2017-10-01

The study underlines the characteristics of the urban heat island of Iași (Iași's UHI) on the basis of 3 years of air temperature measurements obtained by fixed-point observations. We focus on the identification of UHI development and intensity as it is expressed by the temperature differences between the city centre and the rural surroundings. Annual, seasonal and daily characteristics of Iaşi's UHI are investigated at the level of the classical weather observation. In brief, an intensity of 0.8 °C of UHI and a spatial extension which corresponds to the densely built area of the city were delineated. The Iaşi UHI is stronger during summer calm nights—when the inner city is warmer with 2.5-3 °C than the surroundings—and is weaker during windy spring days. The specific features of Iași's UHI bear a profound connection to the specificity of the urban structure, the high atmospheric stability in the region and the local topography. Also, the effects of Iași's UHI upon some environmental aspects are presented as study cases. For instance, under the direct influence of UHI, we have observed that in the city centre, the apricot tree blossoms earlier (with up to 4 days) and the depth of the snow cover is significantly lower (with up to 10 cm for a rural snow depth of 30 cm) than in the surrounding areas.

Dynamics of Hierarchical Urban Green Space Patches and Implications for Management Policy.

PubMed

Yu, Zhoulu; Wang, Yaohui; Deng, Jinsong; Shen, Zhangquan; Wang, Ke; Zhu, Jinxia; Gan, Muye

2017-06-06

Accurately quantifying the variation of urban green space is the prerequisite for fully understanding its ecosystem services. However, knowledge about the spatiotemporal dynamics of urban green space is still insufficient due to multiple challenges that remain in mapping green spaces within heterogeneous urban environments. This paper uses the city of Hangzhou to demonstrate an analysis methodology that integrates sub-pixel mapping technology and landscape analysis to fully investigate the spatiotemporal pattern and variation of hierarchical urban green space patches. Firstly, multiple endmember spectral mixture analysis was applied to time series Landsat data to derive green space coverage at the sub-pixel level. Landscape metric analysis was then employed to characterize the variation pattern of urban green space patches. Results indicate that Hangzhou has experienced a significant loss of urban greenness, producing a more fragmented and isolated vegetation landscape. Additionally, a remarkable amelioration of urban greenness occurred in the city core from 2002 to 2013, characterized by the significant increase of small-sized green space patches. The green space network has been formed as a consequence of new urban greening strategies in Hangzhou. These strategies have greatly fragmented the built-up areas and enriched the diversity of the urban landscape. Gradient analysis further revealed a distinct pattern of urban green space landscape variation in the process of urbanization. By integrating both sub-pixel mapping technology and landscape analysis, our approach revealed the subtle variation of urban green space patches which are otherwise easy to overlook. Findings from this study will help us to refine our understanding of the evolution of heterogeneous urban environments.

Dynamics of Hierarchical Urban Green Space Patches and Implications for Management Policy

PubMed Central

Yu, Zhoulu; Wang, Yaohui; Deng, Jinsong; Shen, Zhangquan; Wang, Ke; Zhu, Jinxia; Gan, Muye

2017-01-01

Accurately quantifying the variation of urban green space is the prerequisite for fully understanding its ecosystem services. However, knowledge about the spatiotemporal dynamics of urban green space is still insufficient due to multiple challenges that remain in mapping green spaces within heterogeneous urban environments. This paper uses the city of Hangzhou to demonstrate an analysis methodology that integrates sub-pixel mapping technology and landscape analysis to fully investigate the spatiotemporal pattern and variation of hierarchical urban green space patches. Firstly, multiple endmember spectral mixture analysis was applied to time series Landsat data to derive green space coverage at the sub-pixel level. Landscape metric analysis was then employed to characterize the variation pattern of urban green space patches. Results indicate that Hangzhou has experienced a significant loss of urban greenness, producing a more fragmented and isolated vegetation landscape. Additionally, a remarkable amelioration of urban greenness occurred in the city core from 2002 to 2013, characterized by the significant increase of small-sized green space patches. The green space network has been formed as a consequence of new urban greening strategies in Hangzhou. These strategies have greatly fragmented the built-up areas and enriched the diversity of the urban landscape. Gradient analysis further revealed a distinct pattern of urban green space landscape variation in the process of urbanization. By integrating both sub-pixel mapping technology and landscape analysis, our approach revealed the subtle variation of urban green space patches which are otherwise easy to overlook. Findings from this study will help us to refine our understanding of the evolution of heterogeneous urban environments. PMID:28587309

Mapping lightscapes: spatial patterning of artificial lighting in an urban landscape.

PubMed

Hale, James D; Davies, Gemma; Fairbrass, Alison J; Matthews, Thomas J; Rogers, Christopher D F; Sadler, Jon P

2013-01-01

Artificial lighting is strongly associated with urbanisation and is increasing in its extent, brightness and spectral range. Changes in urban lighting have both positive and negative effects on city performance, yet little is known about how its character and magnitude vary across the urban landscape. A major barrier to related research, planning and governance has been the lack of lighting data at the city extent, particularly at a fine spatial resolution. Our aims were therefore to capture such data using aerial night photography and to undertake a case study of urban lighting. We present the finest scale multi-spectral lighting dataset available for an entire city and explore how lighting metrics vary with built density and land-use. We found positive relationships between artificial lighting indicators and built density at coarse spatial scales, whilst at a local level lighting varied with land-use. Manufacturing and housing are the primary land-use zones responsible for the city's brightly lit areas, yet manufacturing sites are relatively rare within the city. Our data suggests that efforts to address light pollution should broaden their focus from residential street lighting to include security lighting within manufacturing areas.

Mapping Lightscapes: Spatial Patterning of Artificial Lighting in an Urban Landscape

PubMed Central

Hale, James D.; Davies, Gemma; Fairbrass, Alison J.; Matthews, Thomas J.; Rogers, Christopher D. F.; Sadler, Jon P.

2013-01-01

Artificial lighting is strongly associated with urbanisation and is increasing in its extent, brightness and spectral range. Changes in urban lighting have both positive and negative effects on city performance, yet little is known about how its character and magnitude vary across the urban landscape. A major barrier to related research, planning and governance has been the lack of lighting data at the city extent, particularly at a fine spatial resolution. Our aims were therefore to capture such data using aerial night photography and to undertake a case study of urban lighting. We present the finest scale multi-spectral lighting dataset available for an entire city and explore how lighting metrics vary with built density and land-use. We found positive relationships between artificial lighting indicators and built density at coarse spatial scales, whilst at a local level lighting varied with land-use. Manufacturing and housing are the primary land-use zones responsible for the city’s brightly lit areas, yet manufacturing sites are relatively rare within the city. Our data suggests that efforts to address light pollution should broaden their focus from residential street lighting to include security lighting within manufacturing areas. PMID:23671566

Impact of the China Healthy Cities Initiative on Urban Environment.

PubMed

Yue, Dahai; Ruan, Shiman; Xu, Jin; Zhu, Weiming; Zhang, Luyu; Cheng, Gang; Meng, Qingyue

2017-04-01

The China Healthy Cities initiative, a nationwide public health campaign, has been implemented for 25 years. As "Healthy China 2030" becomes the key national strategy for improving population health, this initiative is an important component. However, the effects of the initiative have not been well studied. This paper aims to explore its impact on urban environment using a multiple time series design. We adopted a stratified and systematic sampling method to choose 15 China healthy cities across the country. For the selected healthy cities, 1:1 matched non-healthy cities were selected as the comparison group. We collected longitudinal data from 5 years before cities achieved the healthy city title up to 2012. We used hierarchical models to calculate difference-in-differences estimates for examining the impact of the initiative. We found that the China Healthy Cities initiative was associated with increases in the proportion of urban domestic sewage treated (32 percentage points), the proportion of urban domestic garbage treated (30 percentage points), and the proportion of qualified farmers' markets (40 percentage points), all of which are statistically significant (P < 0.05). No significant change was found for increases in green coverage of urban built-up area (5 percentage points), green space per capita (2 square meter), and days with Air Quality Index/Air Pollution Index ≤ 100 (25 days). In conclusion, the China Healthy Cities initiative was associated with significant improved urban environment in terms of infrastructure construction, yet had little impact on green space and air quality.

Land Use Land Cover Changes in Detection of Water Quality: A Study Based on Remote Sensing and Multivariate Statistics.

PubMed

Hua, Ang Kean

2017-01-01

Malacca River water quality is affected due to rapid urbanization development. The present study applied LULC changes towards water quality detection in Malacca River. The method uses LULC, PCA, CCA, HCA, NHCA, and ANOVA. PCA confirmed DS, EC, salinity, turbidity, TSS, DO, BOD, COD, As, Hg, Zn, Fe, E. coli , and total coliform. CCA confirmed 14 variables into two variates; first variate involves residential and industrial activities; and second variate involves agriculture, sewage treatment plant, and animal husbandry. HCA and NHCA emphasize that cluster 1 occurs in urban area with Hg, Fe, total coliform, and DO pollution; cluster 3 occurs in suburban area with salinity, EC, and DS; and cluster 2 occurs in rural area with salinity and EC. ANOVA between LULC and water quality data indicates that built-up area significantly polluted the water quality through E. coli , total coliform, EC, BOD, COD, TSS, Hg, Zn, and Fe, while agriculture activities cause EC, TSS, salinity, E. coli , total coliform, arsenic, and iron pollution; and open space causes contamination of turbidity, salinity, EC, and TSS. Research finding provided useful information in identifying pollution sources and understanding LULC with river water quality as references to policy maker for proper management of Land Use area.

Summary of the Journal of Geoscience Education Urban Theme Issue (Published in November, 2004)

NASA Astrophysics Data System (ADS)

Abolins, M. J.

2004-12-01

The urban geoscience education theme issue includes twelve manuscripts describing efforts to make geoscience more inclusive. These efforts reflect two central beliefs: (1) that urban geoscience education more effectively serves urban residents (slightly more than 80% of the American population) and (2) that urban education encourages minority participation in the geosciences. These convictions spawned educational programs serving many different kinds of learners. Educators developed unique curricula to meet the needs of each audience, but most curricula incorporate content associated with the built environment. The following paragraphs summarize audience characteristics and curricular content. Audience Urban geoscience education served many different kinds of learners. Although most programs targeted an audience with a specific level of educational experience (e.g., elementary school students) at a specific location (e.g., Syracuse, NY), audience characteristics varied greatly from one program to another: (1) Participants included elementary, middle, and high school students, undergraduates (both majors and non-majors), K-12 teachers (both pre-service and in-service), graduate students, realtors, and community members. (2) At least three programs served populations with substantial numbers of African American, Hispanic, and Asian American students. (3) Audiences were drawn from every corner of the nation except the Pacific Northwest and Florida and resided in cities varying greatly in population. These cities included the nation's largest combined metropolitan area (New York City, NY-NJ-CT-PA), other metropolitan areas containing populations of over one million, and communities as small as Ithaca, NY (population: 96,501). As illustrated by the preceding examples, urban geoscience education served learners with different levels of educational experience, some programs focused on minority learners, and program participants lived in cities both big and small. Content Most urban geoscience curricula include content associated with the built environment. Some content is organized around themes that are unique to the largest cities, but much content is explicitly suburban. Examples follow: (1) A good example of a theme unique to the largest cities is the impact of geology on the construction of early Twentieth Century skyscrapers. (2) Much explicitly suburban material addresses human-environment interactions in urbanizing areas. The above examples show that curricula described in the theme issue include content relevant to both big city and suburban learners. Summary Although urban geoscience education programs serve many different kinds of learners, most curricula include content focusing on the built environment. Taken together, urban geoscience education programs utilized content relevant to both big city and suburban learners and served audiences with different levels of educational experience and various ethnic backgrounds.

NY-uHMT: A dense hydro-meteorological network to characterize urban land-atmosphere interactions

NASA Astrophysics Data System (ADS)

Ramamurthy, P.; Lakhankar, T.; Khanbilvardi, R.; Devineni, N.

2016-12-01

Most people in the US live in large Metropolitan areas that have a dense urban core in the center, dominated by built surfaces and surrounded by residential/suburban areas that consist a mix of built, vegetated and permeable surfaces. This creates a gradient in the hydro-meteorological environment giving rise to complex land-atmosphere interactions. Current modeling platforms and observational techniques like tower measurements do not adequately account for the underlying heterogeneity. To address this critical gap in our understanding we have instituted a dense network of sensors in the New York Metropolitan area. This unique urban sensor network consists of instrumentation to monitor soil moisture at multiple depths along with air temperature, relative humidity and precipitation, with room to add additional sensors in the future. The network is autonomous and connected to a centralized server using cellular towers. Apart from describing the spatial variability in hydro-meteorological quantities the network will also aid in conducting high-resolution numerical simulations to study and forecast urban weather and climate. In one such simulation conducted to partition the influence of storage flux, wind pattern and circulation and soil moisture deficit on urban heat island intensity (UHI), we found that the daily variability in UHI in NYC was sensitive to available energy and wind pattern. The long-term trend in UHI was however related to soil moisture deficit. In fact a prolonged heat wave period witnessed during summer 2006 correlated well with an extended dry period and the daily UHI in NYC almost doubled. Moreover, the urban soils also suffered from high degree of dessication, owing to drier urban boundary layer.

Community empowerment strategy by sustainable built environment planning in Urban Kampong

NASA Astrophysics Data System (ADS)

Bawole, P.; Sutanto, HB

2018-03-01

Almost all big cities in developing countries have low-income people who live in Urban Kampong. The poor people live mostly near the city center and occupy vacant areas within the city. It is obvious that the low-income people in urban area have to deal with minimal infrastructure facilities in their settlements. They have to live with bad access to the main road, bad environmental quality, and lack of playgrounds for the children, etc. Many positive aspects that can be found in low-income settlement, if they are observed carefully without having negative prejudice before. Those positive aspects are the creative process of the inhabitant for struggling. Since relationship among the inhabitant is quite close, public spaces are necessary for them, because they use them as a place of communication. Besides, the creativity in building their house mostly with used materials make their housing types unique. As a development approach, the way the poor people develop their housing areas can be formulated as strategic approaches for empowering the inhabitants as well as improving the built environment in which the low-income people live. This paper will explain a research in low-income settlements developed in Yogyakarta city.

Urban wild boars prefer fragmented areas with food resources near natural corridors.

PubMed

Castillo-Contreras, Raquel; Carvalho, João; Serrano, Emmanuel; Mentaberre, Gregorio; Fernández-Aguilar, Xavier; Colom, Andreu; González-Crespo, Carlos; Lavín, Santiago; López-Olvera, Jorge R

2018-02-15

Wild boar populations are expanding throughout the world and intruding into periurban and urban areas. In the last years, wild boar has colonized several European cities, including our study area, the city of Barcelona. It is required to identify the main factors driving wild boar into urban areas prior to establish management measures. We built Boosted Regression Trees (BRT) using 3148 wild boar presences registered in the urban area of Barcelona from 2010 to 2014 to identify the variables correlated with these presences. The variables analysed included proxies for distance to source population, urban food resources, climate and urban habitat structure. Wild boars enter the urban area from close natural habitat using corridors such as streams, preferably in fragmented urban environment, looking for food such as urban green areas or dry pet food from cat colonies. Wild boar presence is higher in spring possibly due to the births of piglets and the dispersion of yearlings during that season, and also when natural resources in the Mediterranean habitat fail to satisfy the nutritional requirements of the wild boar population during the summer season. Management measures derived from this study are currently being applied in the city of Barcelona, including vegetation clearings in the wild boar entrance areas and an awareness campaign aimed at reducing the anthropogenic food availability for wild boars. The methodology used can be applied to other cities with wild boar or even other wildlife species issues. The comparison between the factors attracting wild boars into different urban areas would be helpful to understand the global phenomenon. Copyright © 2017 Elsevier B.V. All rights reserved.

Land use pattern, socio-economic development, and assessment of their impacts on ecosystem service value: study on natural wetlands distribution area (NWDA) in Fuzhou city, southeastern China.

PubMed

Cai, Yuan-Bin; Zhang, Hao; Pan, Wen-Bin; Chen, Yan-Hong; Wang, Xiang-Rong

2013-06-01

This paper quantifies the allocation of ecosystem services value (ESV) associated with land use pattern and qualitatively examined impacts of land use changes and socio-economic factors on spatiotemporal variation of ESV in the Natural Wetland Distribution Area (NWDA), Fuzhou city, China. The results showed that total ESV of the study area decreased from 4,332.16 × 10(6) RMB Yuan in 1989 to 3,697.42 × 10(6) RMB Yuan in 2009, mainly due to the remarkable decreases in cropland (decreased by 55.3 %) and wetland (decreased by 74.2 %). Forest, water, and wetland played major roles in providing ecosystem services, accounting for over 90 % of the total ESV. Based on time series Landsat TM/ETM+ imagery, geographic information system, and historical data, analysis of the spatiotemporal variation of ESV from 1989 to 2009 was performed. It indicated that rapid expansion of urban areas along the Minjiang River resulted in significant changes in land use types, leading to a dramatic decline in ecosystem services. Meanwhile, because of land scarcity and unique ecosystem functions, the emergency of wetland and cropland protection in built-up area has become an urgent task of local authorities to the local government. Furthermore, there was still a significant negative correlation between ESV of cropland and wetland and the GDP. The results suggest that future planning of land use pattern should control encroachment of urban areas into cropland and wetland in addition to scientific and rational policies towards minimizing the adverse effects of urbanization.

Gross Primary Productivity and Vegetation Light Use Efficiency of a Large Metropolitan Region based on CO2 Flux Measurements and WorldView-2 Satellite Imagery

NASA Astrophysics Data System (ADS)

Miller, D. L.; Roberts, D. A.; Clarke, K. C.; Peters, E. B.; Menzer, O.; Lin, Y.; McFadden, J. P.

2017-12-01

Gross primary productivity (GPP) is commonly estimated with remote sensing techniques over large regions of Earth; however, urban areas are typically excluded due to a lack of light use efficiency (LUE) parameters specific to urban vegetation and challenges stemming from the spatial heterogeneity of urban land cover. In this study, we estimated GPP during the middle of the growing season, both within and among vegetation and land use types, in the Minneapolis-Saint Paul, Minnesota metropolitan region (52.1% vegetation cover). We derived LUE parameters for specific urban vegetation types using estimates of GPP from eddy covariance and tree sap flow-based CO2 flux observations and fraction of absorbed photosynthetically active radiation derived from 2-m resolution WorldView-2 satellite imagery. We produced a pixel-based hierarchical land cover classification of built-up and vegetated urban land cover classes distinguishing deciduous broadleaf trees, evergreen needleleaf trees, turf grass, and golf course grass from impervious and soil surfaces. The overall classification accuracy was 80% (kappa = 0.73). The mapped GPP estimates were within 12% of estimates from independent tall tower eddy covariance measurements. Mean GPP estimates ( ± standard deviation; g C m-2 day-1) for the entire study area from highest to lowest were: golf course grass (11.77 ± 1.20), turf grass (6.05 ± 1.07), evergreen needleleaf trees (5.81 ± 0.52), and deciduous broadleaf trees (2.52 ± 0.25). Turf grass GPP had a larger coefficient of variation (0.18) than the other vegetation classes ( 0.10). Mean land use GPP for the full study area varied as a function of percent vegetation cover. Urban GPP in general, both including and excluding non-vegetated areas, was less than half that of literature estimates for nearby natural forests and grasslands.

Mapping intra-urban malaria risk using high resolution satellite imagery: a case study of Dar es Salaam.

PubMed

Kabaria, Caroline W; Molteni, Fabrizio; Mandike, Renata; Chacky, Frank; Noor, Abdisalan M; Snow, Robert W; Linard, Catherine

2016-07-30

With more than half of Africa's population expected to live in urban settlements by 2030, the burden of malaria among urban populations in Africa continues to rise with an increasing number of people at risk of infection. However, malaria intervention across Africa remains focused on rural, highly endemic communities with far fewer strategic policy directions for the control of malaria in rapidly growing African urban settlements. The complex and heterogeneous nature of urban malaria requires a better understanding of the spatial and temporal patterns of urban malaria risk in order to design effective urban malaria control programs. In this study, we use remotely sensed variables and other environmental covariates to examine the predictability of intra-urban variations of malaria infection risk across the rapidly growing city of Dar es Salaam, Tanzania between 2006 and 2014. High resolution SPOT satellite imagery was used to identify urban environmental factors associated malaria prevalence in Dar es Salaam. Supervised classification with a random forest classifier was used to develop high resolution land cover classes that were combined with malaria parasite prevalence data to identify environmental factors that influence localized heterogeneity of malaria transmission and develop a high resolution predictive malaria risk map of Dar es Salaam. Results indicate that the risk of malaria infection varied across the city. The risk of infection increased away from the city centre with lower parasite prevalence predicted in administrative units in the city centre compared to administrative units in the peri-urban suburbs. The variation in malaria risk within Dar es Salaam was shown to be influenced by varying environmental factors. Higher malaria risks were associated with proximity to dense vegetation, inland water and wet/swampy areas while lower risk of infection was predicted in densely built-up areas. The predictive maps produced can serve as valuable resources for municipal councils aiming to shrink the extents of malaria across cities, target resources for vector control or intensify mosquito and disease surveillance. The semi-automated modelling process developed can be replicated in other urban areas to identify factors that influence heterogeneity in malaria risk patterns and detect vulnerable zones. There is a definite need to expand research into the unique epidemiology of malaria transmission in urban areas for focal elimination and sustained control agendas.

Human biometeorological analysis of the thermal conditions of the hot Turkish city of Şanliurfa

NASA Astrophysics Data System (ADS)

Toy, Süleyman; Aytaç, Ahmet Serdar; Kántor, Noémi

2018-01-01

This paper offers a throughout human biometeorological assessment about the thermal conditions of Şanliurfa in one of the hottest parts of Turkey, in the hottest period of the year (from April to October), and a comparative analysis of three built-up types (urban, suburban and rural). Therefore, the values of physiologically equivalent temperature (PET), one of the most extensively used indices, were calculated from basic climate data with the help of the RayMan model. It was found by regarding the resulted mean PET values and the occurrence frequency of extreme heat stress periods (PET values above 41 °C) that the urban area exhibited the most unfavourable properties, followed by the suburban and rural areas. We also found very severe heat stress conditions in the summer, which may be explained by the torrid and arid climate, calm air conditions and the lack of abundant vegetation. Aiming to optimise human thermal conditions, thereby improving local life quality and facilitating international tourism, increment of vegetated areas and water surfaces would be required and, of course, highlighting the traditional methods taking into account the important aspects of sustainability.

Scintillometer measurements above the urban area of London

NASA Astrophysics Data System (ADS)

Pauscher, Lukas; Salmond, Jennifer; Grimmond, C. S. B.; Foken, Thomas

2010-05-01

The spatial heterogeneity of urban surfaces presents a particular challenge to the measurement of turbulent fluxes. This is particularly true close to the urban surface (in the roughness sub-layer (RSL)) where the mosaic of roof top and street canyon surfaces present a complex three dimensional source area. Scintillometery, which offers the ability to make path-averaged measurements of turbulent fluxes of heat and momentum, provides an alternative approach to obtaining more spatially representative data sets in the RSL. In this study three Scintec small aperture scintillometers (SLS 20) were used to measure the sensible heat flux (QH) at a densely built up site at Strand Campus, King's College London, UK. Two different surfaces (courtyard and rooftop) characteristic of the urban environment were investigated simultaneously. One of the SLS was aligned just atop a courtyard (z/zH= 0.9), while the other two were set up in two different heights (z/zH= 1 and z/zH= 1.25) above a rooftop line. Where zH is the mean building height and z is the measurement height above ground level. Special consideration was given to the estimation of the displacement height and the influence of the Monin-Obukov function used for the analysis. To estimate the contribution of the different surface types to the observed fluxes a footprint analysis was carried out for the two rooftop SLS and the eddy covariance system. Fluxes from the two SLS above the rooftop generally agreed well with each other and exhibited a pronounced diurnal cycle. They also showed similar patterns and magnitudes as those measured by an eddy covariance system located close by. In contrast, diurnal flux patterns derived from the measurements atop the courtyard showed marked differences, especially during day time when fluxes often remained smaller.

[Comparition of ecological security stress effects of artificial landscapes on natural landscapes in different rapid urban sprawl areas].

PubMed

Lin, Mei Xia; Lin, Tao; Qiu, Quan Yi; Sun, Cai Ge; Deng, Fu Liang; Zhang, Guo Qin

2017-04-18

The expansion of built-up area will cause stress effect on the regional natural ecological security pattern during urbanization process. Taking rapid expanding regions of four inland and coastal cities as study areas, including Tongzhou in Beijing, Zhengding in Hebei, Tanggu in Tianjin and Xiamen in Fujian, we constructed regional landscape stress indexes according to the principle of landscape ecology and comparatively analyzed the landscape pattern characteristics of rapid expanding regions and the differences of stress effect of artificial landscapes on four natural landscapes ecological security pattern in the process of rapid urbanization. Results showed that landscape erosion indexes of Tongzhou, Zhengding, Tanggu and Xiamen in 2015 were 1.039, 0.996, 1.239 and 0.945, respectively, which indicated that the natural landscapes were eroded significantly. Natural landscape types of those four regions presented different threatened levels. Among all natural landscape types, unused land and waters were worst threatened in Tongzhou, Zhengding and Tanggu, while in Xiamen cultivated land and waters showed the highest threat levels. The waters threat indexes of those four areas were all more than 0.743. Landscape isolation indexes of waters and unused land of the inland cities were greater than those of coastal cities, which meant water distribution of inland cities in the space was less gathered than that of coastal cities. Besides, compared with the other natural landscape, unused land and waters suffered the largest stress from artificial landscapes.

The influence of the interactions between anthropogenic activities and multiple ecological factors on land surface temperatures of urban forests

NASA Astrophysics Data System (ADS)

Ren, Y.

2017-12-01

Context Land surface temperatures (LSTs) spatio-temporal distribution pattern of urban forests are influenced by many ecological factors; the identification of interaction between these factors can improve simulations and predictions of spatial patterns of urban cold islands. This quantitative research requires an integrated method that combines multiple sources data with spatial statistical analysis. Objectives The purpose of this study was to clarify urban forest LST influence interaction between anthropogenic activities and multiple ecological factors using cluster analysis of hot and cold spots and Geogdetector model. We introduced the hypothesis that anthropogenic activity interacts with certain ecological factors, and their combination influences urban forests LST. We also assumed that spatio-temporal distributions of urban forest LST should be similar to those of ecological factors and can be represented quantitatively. Methods We used Jinjiang as a representative city in China as a case study. Population density was employed to represent anthropogenic activity. We built up a multi-source data (forest inventory, digital elevation models (DEM), population, and remote sensing imagery) on a unified urban scale to support urban forest LST influence interaction research. Through a combination of spatial statistical analysis results, multi-source spatial data, and Geogdetector model, the interaction mechanisms of urban forest LST were revealed. Results Although different ecological factors have different influences on forest LST, in two periods with different hot spots and cold spots, the patch area and dominant tree species were the main factors contributing to LST clustering in urban forests. The interaction between anthropogenic activity and multiple ecological factors increased LST in urban forest stands, linearly and nonlinearly. Strong interactions between elevation and dominant species were generally observed and were prevalent in either hot or cold spots areas in different years. Conclusions In conclusion, a combination of spatial statistics and GeogDetector models should be effective for quantitatively evaluating interactive relationships among ecological factors, anthropogenic activity and LST.

Calibrated Multi-Temporal Edge Images for City Infrastructure Growth Assessment and Prediction

NASA Astrophysics Data System (ADS)

Al-Ruzouq, R.; Shanableh, A.; Boharoon, Z.; Khalil, M.

2018-03-01

Urban Growth or urbanization can be defined as the gradual process of city's population growth and infrastructure development. It is typically demonstrated by the expansion of a city's infrastructure, mainly development of its roads and buildings. Uncontrolled urban Growth in cities has been responsible for several problems that include living environment, drinking water, noise and air pollution, waste management, traffic congestion and hydraulic processes. Accurate identification of urban growth is of great importance for urban planning and water/land management. Recent advances in satellite imagery, in terms of improved spatial and temporal resolutions, allows for efficient identification of change patterns and the prediction of built-up areas. In this study, two approaches were adapted to quantify and assess the pattern of urbanization, in Ajman City at UAE, during the last three decades. The first approach relies on image processing techniques and multi-temporal Landsat satellite images with ground resolution varying between 15 to 60 meters. In this approach, the derived edge images (roads and buildings) were used as the basis of change detection. The second approach relies on digitizing features from high-resolution images captured at different years. The latest approach was adopted, as a reference and ground truth, to calibrate extracted edges from Landsat images. It has been found that urbanized area almost increased by 12 folds during the period 1975-2015 where the growth of buildings and roads were almost parallel until 2005 when the roads spatial expansion witnessed a steep increase due to the vertical expansion of the City. Extracted Edges features, were successfully used for change detection and quantification in term of buildings and roads.

The ecological impact of city lighting scenarios: exploring gap crossing thresholds for urban bats.

PubMed

Hale, James D; Fairbrass, Alison J; Matthews, Thomas J; Davies, Gemma; Sadler, Jon P

2015-02-02

As the global population urbanizes, dramatic changes are expected in city lighting and the urban form, which may threaten the functioning of urban ecosystems and the services they deliver. However, little is known about the ecological impact of lighting in different urban contexts. Movement is an important ecological process that can be disrupted by artificial lighting. We explored the impact of lighting on gap crossing for Pipistrellus pipistrellus, a species of bat (Chiroptera) common within UK cities. We aimed to determine whether the probability of crossing gaps in tree cover varied with crossing distance and lighting level, through stratified field surveys. We then used the resulting data on barrier thresholds to model the landscape resistance due to lighting across an entire city and explored the potential impact of scenarios for future changes to street lighting. The level of illumination required to create a barrier effect reduced as crossing distance increased. For those gaps where crossing was recorded, bats selected the darker parts of gaps. Heavily built parts of the case study city were associated with large and brightly lit gaps, and spatial models indicate movement would be highly restricted in these areas. Under a scenario for brighter street lighting, the area of accessible land cover was further reduced in heavily built parts of the city. We believe that this is the first study to demonstrate how lighting may create resistance to species movement throughout an entire city. That connectivity in urban areas is being disrupted for a relatively common species raises questions about the impacts on less tolerant groups and the resilience of bat communities in urban centres. However, this mechanistic approach raises the possibility that some ecological function could be restored in these areas through the strategic dimming of lighting and narrowing of gaps. © 2015 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Effect of synthetic surfaces and vegetation in urban areas on human energy balance and comfort

Treesearch

Thomas F. Stark; David R. Miller

1977-01-01

The thermal balance of a standard man was quantified for a variety of urban and rural summer daytime microclimates. The resulting net heat-load data were correlated with the relative amounts of vegetation and synthetic materials at each site. By extrapolating these results, it is possible to estimate the expected heat load of a proposed development before it is built...

Bird Diversity and Distribution in relation to Urban Landscape Types in Northern Rwanda

PubMed Central

Gatesire, T.; Nsabimana, D.; Nyiramana, A.; Seburanga, J. L.; Mirville, M. O.

2014-01-01

Using the point count method, linear mixed models, Shannon's diversity index, and Bray-Curtis cluster analysis, we conducted a study of the effect of urban fabric layout on bird diversity and distribution in northern Rwanda. The results showed a significant effect of city landscapes on bird richness and relative abundance; residential neighborhoods, institutional grounds, and informal settlements had the highest species diversity in comparison to other microlandscape types. Riversides were characterized by specialized bird species, commonly known to be restricted to wetland environments. Built-up areas and open field landscapes had comparable results. One Albertine Rift endemic bird species, the Ruwenzori Double-collared Sunbird (Cinnyris stuhlmanni), was recorded. Three migratory birds were found in Musanze city for the first time: the Common Sandpiper (Actitis hypoleucos), the Spotted Flycatcher (Muscicapa striata), and the Willow Warbler (Phylloscopus trochilus). Two bird species have not been previously reported in Rwanda: the Garden Warbler (Sylvia borin) and the Lesser Spotted Eagle (Aquila pomarina). The implications of this study are particularly relevant to urban decision makers who should consider the existence of a great diversity of avian fauna when developing and implementing master plans, especially when villages and cities are in proximity of protected areas or natural reserves. PMID:25133203

External built residential environment characteristics that affect mental health of adults.

PubMed

Ochodo, Charles; Ndetei, D M; Moturi, W N; Otieno, J O

2014-10-01

External built residential environment characteristics include aspects of building design such as types of walls, doors and windows, green spaces, density of houses per unit area, and waste disposal facilities. Neighborhoods that are characterized by poor quality external built environment can contribute to psychosocial stress and increase the likelihood of mental health disorders. This study investigated the relationship between characteristics of external built residential environment and mental health disorders in selected residences of Nakuru Municipality, Kenya. External built residential environment characteristics were investigated for 544 residents living in different residential areas that were categorized by their socioeconomic status. Medically validated interview schedules were used to determine mental health of residents in the respective neighborhoods. The relationship between characteristics of the external built residential environment and mental health of residents was determined by multivariable logistic regression analyses and chi-square tests. The results show that walling materials used on buildings, density of dwelling units, state of street lighting, types of doors, states of roofs, and states of windows are some built external residential environment characteristics that affect mental health of adult males and females. Urban residential areas that are characterized by poor quality external built environment substantially expose the population to daily stressors and inconveniences that increase the likelihood of developing mental health disorders.

Significant alteration of Critical Zone processes in urban watersheds: shifting from a transport-limited to a weathering-limited regime

NASA Astrophysics Data System (ADS)

Moore, J.; Bird, D. L.; Dobbis, S. K.; Woodward, G.

2016-12-01

Urban areas and associated impervious surface cover (ISC) are among the fastest growing land use types. Rapid growth of urban lands has significant implications for geochemical cycling and solute sources to streams, estuaries, and coastal waters. However, little work has been done to investigate the impacts of urbanization on Critical Processes, including on the export of solutes from urban watersheds. Despite observed elevated solute concentrations in urban streams in some previous studies, neither solute sources nor total solute fluxes have been quantified due to mixed bedrock geology, lack of a forested reference watershed, or the presence of point sources that confounded separation of anthropologic and natural sources. We investigated the geochemical signal of the urban built environment (e.g., roads, parking lots, buildings) in a set of five USGS-gaged watersheds across a rural (forested) to urban gradient in the Maryland Piedmont. These watersheds have ISC ranging from 0 to 25%, no point sources, and similar felsic bedrock chemistry. Weathering from the urban built environment and ISC produces dramatically higher solute concentrations in urban watersheds than in the forested watershed. Higher solute concentrations result in chemical weathering fluxes from urban watersheds that are 11-13 times higher than the forested watershed and are similar to fluxes from mountainous, weathering-limited watersheds rather than fluxes from transport-limited, dilute streams like the forested watershed. Weathering of concrete in urban watersheds produces geochemistry similar to weathering-limited watersheds with high concentrations of Ca2+, Mg2+, and DIC, which is similar to stream chemistry due to carbonate weathering. Road salt dissolution results in high Na+ and Cl- concentrations similar to evaporite weathering. Quantifying processes causing elevated solute fluxes from urban areas is essential to understanding cycling of Ca2+, Mg2+, and DIC in urban streams and in downgradient estuarine or coastal waters.

Evaluating Water and Energy Fluxes across Three Land Cover Types in a Desert Urban Environment through a Mobile Eddy Covariance Platform

NASA Astrophysics Data System (ADS)

Pierini, N.; Vivoni, E. R.; Schreiner-McGraw, A.; Lopez-Castrillo, I.

2015-12-01

The urbanization process transforms a natural landscape into a built environment with many engineered surfaces, leading to significant impacts on surface energy and water fluxes across multiple spatial and temporal scales. Nevertheless, the effects of different urban land covers on energy and water fluxes has been rarely quantified across the large varieties of construction materials, landscaping and vegetation types, and industrial, commercial and residential areas in cities. In this study, we deployed a mobile eddy covariance tower at three different locations in the Phoenix, Arizona, metropolitan area to capture a variety of urban land covers. The three locations each represent a common urban class in Phoenix: 1) a dense, xeric landscape (gravel cover and native plants with drip-irrigation systems near tall buildings); 2) a high-density urban site (asphalt-paved parking lot near a high-traffic intersection); and 3) a suburban mesic landscape (sprinkler-irrigated turf grass in a suburban neighborhood). At each site, we measured meteorological variables, including air temperature and relative humidity at three heights, precipitation and pressure, surface temperature, and soil moisture and temperature (where applicable), to complement the eddy covariance measurements of radiation, energy, carbon dioxide and water vapor fluxes. We evaluated the tower footprint at each site to characterize the contributing surface area to the flux measurements, including engineered and landscaping elements, as a function of time for each deployment. The different sites allowed us to compare how turbulent fluxes of water vapor and carbon dioxide vary for these representative urban land covers, in particular with respect to the role of precipitation events and irrigation. While the deployments covered different seasons, from winter to summer in 2015, the variety of daily conditions allowed quantification of the differential response to precipitation events during the winter, pre-monsoon, and monsoon seasons in relation to irrigation input or lack thereof. As desert urban areas continue to grow worldwide, it is essential to gain an improved understanding of how the energy and water balances vary across the built environment and their implications on urban climate, energy, hydrologic conditions, and air quality.

The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China.

PubMed

Huang, Qunfang; Lu, Yuqi

2015-07-27

The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957-2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming.

The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China

PubMed Central

Huang, Qunfang; Lu, Yuqi

2015-01-01

The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957–2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming. PMID:26225986

A new urban landscape in East-Southeast Asia, 2000-2010

NASA Astrophysics Data System (ADS)

Schneider, A.; Mertes, C. M.; Tatem, A. J.; Tan, B.; Sulla-Menashe, D.; Graves, S. J.; Patel, N. N.; Horton, J. A.; Gaughan, A. E.; Rollo, J. T.; Schelly, I. H.; Stevens, F. R.; Dastur, A.

2015-03-01

East-Southeast Asia is currently one of the fastest urbanizing regions in the world, with countries such as China climbing from 20 to 50% urbanized in just a few decades. By 2050, these countries are projected to add 1 billion people, with 90% of that growth occurring in cities. This population shift parallels an equally astounding amount of built-up land expansion. However, spatially-and temporally-detailed information on regional-scale changes in urban land or population distribution do not exist; previous efforts have been either sample-based, focused on one country, or drawn conclusions from datasets with substantial temporal/spatial mismatch and variability in urban definitions. Using consistent methodology, satellite imagery and census data for >1000 agglomerations in the East-Southeast Asian region, we show that urban land increased >22% between 2000 and 2010 (from 155 000 to 189 000 km2), an amount equivalent to the area of Taiwan, while urban populations climbed >31% (from 738 to 969 million). Although urban land expanded at unprecedented rates, urban populations grew more rapidly, resulting in increasing densities for the majority of urban agglomerations, including those in both more developed (Japan, South Korea) and industrializing nations (China, Vietnam, Indonesia). This result contrasts previous sample-based studies, which conclude that cities are universally declining in density. The patterns and rates of change uncovered by these datasets provide a unique record of the massive urban transition currently underway in East-Southeast Asia that is impacting local-regional climate, pollution levels, water quality/availability, arable land, as well as the livelihoods and vulnerability of populations in the region.

Assessment of Selânik Street/Ankara as a Living Urban Space

NASA Astrophysics Data System (ADS)

Işıklar, Sena; Kırcı, Nazan

2017-10-01

Urban spaces create their physical existence through streets and the spaces left between the buildings. However, the user activities within the city avail a produced area consisting of streets and buildings to become a living space. According to Jacobs, the more the urban spaces are used, the livelier and more vivacious spaces are going to be provided. The use of space by individuals is in close connection with some characteristics of the space. Among these, the multi-functionality of the space, the regularity in its night and day utility patterns, and the availability of conditions of comfort and aesthetics, its adaptability depending on the requirements of time could be mentioned. In order to scrutinise the relationship between the spatial characteristics of a built-up space and its utility Selânik Street/Ankara was selected as our field of study. Firstly, the characteristics of living spaces have been defined within the study. Then the use of units and the structural analysis of Selânik Street was undertaken; and the area was studied in terms of the use of open spaces and conditions of comfort. The use of space by the users was revealed through observation. As a result of the assessments, the spatial deficiencies of the field of study was identified. Proposals were made for transforming Selânik Street into a living urban space, such as the organisation of its utility patterns, the addition of activities that draw the users to the area, providing conditions of comfort and increasing aesthetic values.

Rainfall-induced landslide vulnerability Assessment in urban area reflecting Urban structure and building characteristics

NASA Astrophysics Data System (ADS)

Park, C.; Cho, M.; Lee, D.

2017-12-01

Landslide vulnerability assessment methodology of urban area is proposed with urban structure and building charateristics which can consider total damage cost of climate impacts. We used probabilistic analysis method for modeling rainfall-induced shallow landslide susceptibility by slope stability analysis and Monte Carlo simulations. And We combined debris flows with considering spatial movements under topographical condition and built environmental condition. Urban vulnerability of landslide is assessed by two categories: physical demages and urban structure aspect. Physical vulnerability is related to buildings, road, other ubran infra. Urban structure vulnerability is considered a function of the socio-economic factors, trigger factor of secondary damage, and preparedness level of the local government. An index-based model is developed to evaluate the life and indirect damage under landslide as well as the resilience ability against disasters. The analysis was performed in a geographic information system (GIS) environment because GIS can deal efficiently with a large volume of spatial data. The results of the landslide susceptibility assessment were compared with the landslide inventory, and the proposed approach demonstrated good predictive performance. The general trend found in this study indicates that the higher population density areas under a weaker fiscal condition that are located at the downstream of mountainous areas are more vulnerable than the areas in opposite conditions.

Impacts of Trees on Urban Environment in the Contiguous United States

NASA Astrophysics Data System (ADS)

Wang, C.; Upreti, R.; Wang, Z.; Yang, J.

2017-12-01

Mounting empirical evidence shows that urban trees are effective in mitigating the thermal stress in the built environment, whereas large scale numerical simulations remain scarce. In this study, we evaluated the effects of shade trees on the built environment in terms of radiative cooling, pedestrian thermal comfort, and surface energy balance, carried out over the contiguous United States (CONUS). A coupled Weather Research and Forecasting-urban modeling system was adopted, incorporating exclusively the radiative shading effect of urban trees. Results show that on average the mean 2-m air temperature in urban areas decreases by 3.06 ˚C, and the 2-m relative humidity increases by 13.62% over the entire CONUS with the shading effect. Analysis of pedestrian thermal comfort shows that shade trees help to improve summer thermal comfort level, but could be detrimental in the winter for Northern cities. In addition, it was found that trees alter the surface energy balance by primarily enhancing the radiative cooling, leading to significant re-distribution of the sensible heat while leaving the ground heat storage comparatively intact.

The Human Appropriation of Ecosystem Service Values (HAESV) in the Sundarban Biosphere Region Using Biophysical Quantification Approach

NASA Astrophysics Data System (ADS)

Sannigrahi, S.; Paul, S. K.; Sen, S.

2017-12-01

Human appropriation, especially unusual changes in land-use and land cover, significantly affects ecosystem services and functions. Driven by the growth of the population and the economy, human demands on earth's land surface have increased dramatically in the past 50 - 100 years. The area studied was divided into six major categories; cropland, mangrove forest, sparse vegetation, built-up urban area, water bodies and sandy coast, and the land coverage was calculated for the years 1973, 1988, 2002 and 2013. The spatial explicit value of the primary regulatory and supporting ecosystem services (climate regulation, raw material production, water regulation) were quantified through the indirect market valuation approach. A light use efficiency based ecosystem model, i.e. Carnegie- Ames-Stanford-Approach (CASA) was employed to estimate the carbon sequestration and oxygen production services of the ecosystem. The ArcGIS matrix transform approach calculated LULC dynamics among the classes. Investigation revealed that the built-up urban area increased from 42.9 km2 in 1973 to 308 km2 in 2013 with a 6.6 km2 yr-1 expansion rate. Similarly, water bodies (especially inland water bodies increased dramatically in the north central region) increased from 3392.1 sq.km in 1973 to 5420 sq.km in 2013 at the expense of semi-natural and natural land resulting in significant changes of ecological and ecosystem services. However, the area occupied by dense mangrove forest decreased substantially during the 40 years (1973 -2013); it was recorded to cover 2294 km2 in 1973 and 1820 km2 in 2013. The results showed that the estimated regulatory and supporting ecosystem services respond quite differently to human appropriation across the regions in both the economic and ecological dimensions. While evaluating the trade-of between human appropriation and ecosystem service changes, it has been estimated that the ecosystem service value of organic matter provision services decreased from 755 US ha-1 in 2000 to 608 US ha-1 in 2013. Therefore, the rigorous and centralised policy for sustainable and regionally balanced land-use planning has been essential in the recent era for economic viability, and ecosystem preservation, to prevent undesirable outcomes.

Understanding Climate Variability of Urban Ecosystems Through the Lens of Citizen Science

NASA Astrophysics Data System (ADS)

Ripplinger, J.; Jenerette, D.; Wang, J.; Chandler, M.; Ge, C.; Koutzoukis, S.

2017-12-01

The Los Angeles megacity is vulnerable to climate warming - a process that locally exacerbates the urban heat island effect as it intensifies with size and density of the built-up area. We know that large-scale drivers play a role, but in order to understand local-scale climate variation, more research is needed on the biophysical and sociocultural processes driving the urban climate system. In this study, we work with citizen scientists to deploy a high-density network of microsensors across a climate gradient to characterize geographic variation in neighborhood meso- and micro-climates. This research asks: How do urbanization, global climate, and vegetation interact across multiple scales to affect local-scale experiences of temperature? Additionally, citizen scientist-led efforts generated research questions focused on examining microclimatic differences among yard groundcover types (rock mulch vs. lawn vs. artificial turf) and also on variation in temperature related to tree cover. Combining sensor measurements with Weather Research and Forecasting (WRF) spatial models and satellite-based temperature, we estimate spatially-explicit maps of land surface temperature and air temperature to illustrate the substantial difference between surface and air urban heat island intensities and the variable degree of coupling between land surface and air temperature in urban areas. Our results show a strong coupling between air temperature variation and landcover for neighborhoods, with significant detectable signatures from tree cover and impervious surface. Temperature covaried most strongly with urbanization intensity at nighttime during peak summer season, when daily mean air temperature ranged from 12.8C to 30.4C across all groundcover types. The combined effects of neighborhood geography and vegetation determine where and how temperature and tree canopy vary within a city. This citizen science-enabled research shows how large-scale climate drivers and urbanization intensity jointly influence the nature and magnitude of coupling between air temperature and tree cover, and demonstrate how urban vegetation provides an important ecosystem service in cities by decreasing the intensity of local urban heat islands.

The place character as land use change determinant in Deli Serdang

NASA Astrophysics Data System (ADS)

Lindarto, D.; Sirojuzilam; Badaruddin; Aulia, DN

2018-03-01

The Mebidangro concept of development (Medan, Binjai, Deli Serdang, Karo) in Sumatera Utara creating peri urban area in region hinterland Medan city especially in Tembung village, Percut Sei Tuan District. This peri urban area is a conjunction of several rural-urban activities that forming a friendly atmosphere. The dynamic of population structure shows occurrence the sprawl of land use change condition. In the site of the urban region showing the unique performance that built the place character. The aim of the study is to uncover the place character as one of land use change determinant factors. The study conducted with quantitative approach intended at obtaining variables which describing several factors forming land use change. Descriptive approach give an idea, justification, and fact-finding with correct interpretation. Data collected through a purposive sampling of 320 respondents who stay and built the building and land between 2010 till 2014. With overlay figure/ground technique, scoring analysis, descriptive quantitative and SEM (Structural Equational Models) gained a result that urban heritage (p=0,008) potentially as one of the main land use change driving factors besides accessibility (p=0,039), infrastructure (p=0,010), social-economic (p=0,038) in fact topographic factor (p=0,663) was inversely potentially. The implication of the findings is required intensive attention toward the form of place character (mosque, the quarter, district activity, peri urban edges city and railway) as determinant factors of land use change considering forming the identity of the rapid change in land use transformation.

An Analysis of the Advantages and Disadvantages of the Air Force Standard Control Panel

DTIC Science & Technology

1989-09-01

comparativ - process. The built-up system required approximately 100 hours to design , install and calibrate. The reader is reminded that the built-up...Summary......................................... 9 Outline of Research Design .................... 9 Ii. Literature Review...133 Question 3 .......................... 133 Area 3: Design Phase ................... 134 Question 4 .......................... 134 Area 4

Assessing the urban solar energy resource potential of Davao City, Philippines, using LiDAR Digital Surface Model (DSM) and GRASS GIS

NASA Astrophysics Data System (ADS)

Teves, Justine; Sola, Eula Fae; Pintor, Ben Hur; Ang, Ma. Rosario Concepcion

2016-10-01

Solar energy is emerging as one of the top options for renewable energy sources in the Philippines, with largescale solar photovoltaic (PV) farms being built all over the country. Solar energy resource in the urban environment has great potential in making a city self-sustaining, but has not been fully explored for the country. In order to represent its potential, reliable resource assessment should be done. This study aims to assess the available solar energy resource in Davao City, a trade and commerce hub in southern Philippines. The functions of GRASS GIS, specifically the r.sun module, in modelling incoming solar radiation is discussed, along with the use of a one-meter LiDAR Digital Surface Model (DSM) and Linke Turbidity coefficients as inputs. The average Julian day of each month was used to compute the Global Horizontal Irradiation (GHI) values under clear-sky or cloudless conditions. To account for the effects of the clouds in the study area, the clear-sky indices (Kc) were computed using data from solar recording stations of the Bureau of Soils and Water Management (BSWM) found within and around the region. These were multiplied to the modelled clear-sky GHI rasters to get the real-sky GHI. The results show that the city's average GHI potential ranges from 2693.79 Wh/m2 and 4453.13 Wh/m2. Average values are particularly higher around the months of March and April, while lower values are seen in the months of November and January. Areas with higher potential are seen in the southern portion of the city, consistent in built-up areas.

Arctic cities and climate change: climate-induced changes in stability of Russian urban infrastructure built on permafrost

NASA Astrophysics Data System (ADS)

Shiklomanov, Nikolay; Streletskiy, Dmitry; Swales, Timothy

2014-05-01

Planned socio-economic development during the Soviet period promoted migration into the Arctic and work force consolidation in urbanized settlements to support mineral resources extraction and transportation industries. These policies have resulted in very high level of urbanization in the Soviet Arctic. Despite the mass migration from the northern regions during the 1990s following the collapse of the Soviet Union and the diminishing government support, the Russian Arctic population remains predominantly urban. In five Russian Administrative regions underlined by permafrost and bordering the Arctic Ocean 66 to 82% (depending on region) of the total population is living in Soviet-era urban communities. The political, economic and demographic changes in the Russian Arctic over the last 20 years are further complicated by climate change which is greatly amplified in the Arctic region. One of the most significant impacts of climate change on arctic urban landscapes is the warming and degradation of permafrost which negatively affects the structural integrity of infrastructure. The majority of structures in the Russian Arctic are built according to the passive principle, which promotes equilibrium between the permafrost thermal regime and infrastructure foundations. This presentation is focused on quantitative assessment of potential changes in stability of Russian urban infrastructure built on permafrost in response to ongoing and future climatic changes using permafrost - geotechnical model forced by GCM-projected climate. To address the uncertainties in GCM projections we have utilized results from 6 models participated in most recent IPCC model inter-comparison project. The analysis was conducted for entire extent of Russian permafrost-affected area and on several representative urban communities. Our results demonstrate that significant observed reduction in urban infrastructure stability throughout the Russian Arctic can be attributed to climatic changes and that projected future climatic changes will further negatively affect communities on permafrost. However, the uncertainties in magnitude and spatial and temporal patterns of projected climate change produced by individual GCMs translate to substantial variability of the future state of infrastructure built on permafrost.

Alternative approaches to condition monitoring in freeway management systems.

DOT National Transportation Integrated Search

2002-01-01

In response to growing concerns over traffic congestion, traffic management systems have been built in large urban areas in an effort to improve the efficiency and safety of the transportation network. This research effort developed an automated cond...

Aquaculture in artificially developed wetlands in urban areas: an application of the bivariate relationship between soil and surface water in landscape ecology.

PubMed

Paul, Abhijit

2011-01-01

Wetlands show a strong bivariate relationship between soil and surface water. Artificially developed wetlands help to build landscape ecology and make built environments sustainable. The bheries, wetlands of eastern Calcutta (India), utilize the city sewage to develop urban aquaculture that supports the local fish industries and opens a new frontier in sustainable environmental planning research.

Global scenarios of urban density and its impacts on building energy use through 2050.

PubMed

Güneralp, Burak; Zhou, Yuyu; Ürge-Vorsatz, Diana; Gupta, Mukesh; Yu, Sha; Patel, Pralit L; Fragkias, Michail; Li, Xiaoma; Seto, Karen C

2017-08-22

Although the scale of impending urbanization is well-acknowledged, we have a limited understanding of how urban forms will change and what their impact will be on building energy use. Using both top-down and bottom-up approaches and scenarios, we examine building energy use for heating and cooling. Globally, the energy use for heating and cooling by the middle of the century will be between 45 and 59 exajoules per year (corresponding to an increase of 7-40% since 2010). Most of this variability is due to the uncertainty in future urban densities of rapidly growing cities in Asia and particularly China. Dense urban development leads to less urban energy use overall. Waiting to retrofit the existing built environment until markets are ready in about 5 years to widely deploy the most advanced renovation technologies leads to more savings in building energy use. Potential for savings in energy use is greatest in China when coupled with efficiency gains. Advanced efficiency makes the least difference compared with the business-as-usual scenario in South Asia and Sub-Saharan Africa but significantly contributes to energy savings in North America and Europe. Systemic efforts that focus on both urban form, of which urban density is an indicator, and energy-efficient technologies, but that also account for potential co-benefits and trade-offs with human well-being can contribute to both local and global sustainability. Particularly in growing cities in the developing world, such efforts can improve the well-being of billions of urban residents and contribute to mitigating climate change by reducing energy use in urban areas.

A study on the interaction and evolution of the spatial expansion and administrative division adjustment in Beijing metropolitan area

NASA Astrophysics Data System (ADS)

Li, Yongfu; Dang, Anrong

2008-10-01

Since 1990s and especially since 2000, the city space of Beijing has grown rapidly. There's no doubt that the urban construction land area is expanding to the suburban areas, which is the result of rapid social and economic growth in the city and also closely related to the reform of "turning county into district". In other words, the adjustment of administrative division in Beijing interacts with the expansion of urban construction land space. Beijing turns counties into districts and introduces regional offices are two distinct evidence. As for the interaction, there're both advantages and disadvantages and the focus of the article is to explore how to exploit the favorable conditions and avoid unfavorable ones. The article takes the town administrative region as the minimum space unit so as to better explore the anisotropism and regional differences of city space expansion as well as the impact caused by the adjustment of administrative divisions. With initial analysis, we find that: firstly, on the contrary to the sharp reduction of farming land, the city construction land are for residential communities, factories and mines increases the fastest; secondly, the big central cluster expansion has great regional difference and the three directions of northwest, north and south grows the fastest, which is mainly caused by the positive guidance of trunk roads including highway construction; thirdly, the land area in central cluster used for new construction projects is mainly located in suburban area, but exurb districts of Daxing and Changping also take up a considerable proportion; fourthly, as for the key exurb towns including Changping, Shunyi, and Fangshan, the built-up area also grows rapidly.

Characterizing Urban Volumetry Using LIDAR Data

NASA Astrophysics Data System (ADS)

Santos, T.; Rodrigues, A. M.; Tenedório, J. A.

2013-05-01

Urban indicators are efficient tools designed to simplify, quantify and communicate relevant information for land planners. Since urban data has a strong spatial representation, one can use geographical data as the basis for constructing information regarding urban environments. One important source of information about the land status is imagery collected through remote sensing. Afterwards, using digital image processing techniques, thematic detail can be extracted from those images and used to build urban indicators. Most common metrics are based on area (2D) measurements. These include indicators like impervious area per capita or surface occupied by green areas, having usually as primary source a spectral image obtained through a satellite or airborne camera. More recently, laser scanning data has become available for large-scale applications. Such sensors acquire altimetric information and are used to produce Digital Surface Models (DSM). In this context, LiDAR data available for the city is explored along with demographic information, and a framework to produce volumetric (3D) urban indexes is proposed, and measures like Built Volume per capita, Volumetric Density and Volumetric Homogeneity are computed.

Near surface geophysics techniques and geomorphological approach to reconstruct the hazard cave map in historical and urban areas

NASA Astrophysics Data System (ADS)

Lazzari, M.; Loperte, A.; Perrone, A.

2009-04-01

This work, carried out with an integrated methodological approach, focuses on the use of near surface geophysics techniques, such as ground penetrating radar GPR and electrical resistivity tomography (ERT), and geomorphological analysis, in order to reconstruct the cave distribution and geometry in a urban context and, in particular, in historical centres. In fact, there are a lot of historical Mediterranean sites born on an original rupestrian settlement, of which often the new generations forgot the memory and new urban areas built on them burying any marks. The interaction during recent centuries between human activity (caves excavation, birth and growth of an urban area) and the characters of the natural environment were the reasons of a progressive increase in hazard and vulnerability levels of several sites. The reconstruction of a detailed cave map distribution is the first step to define the anthropic and geomorphological hazard in urban areas, fundamental basis for planning and assessing the risk. The integrated near surface geophysics and geomorphological techniques have been applied to the case study of Tursi hilltop town and its older nucleus called Rabatana, located in the south-western sector of the Basilicata (southern Italy), representing an interesting example of the deep bond between natural and man-made environments such as precious cultural heritage. The history of this settlement has always been deeply connected with the characteristics of the neighbouring environment and it seems possible that the first settlement was built by excavating the slopes of the sandy relief. It was a typical rupestrian settlement, where meteoric water was stored inside some cisterns excavated on the slopes. During recent centuries, the increase in territory development by humans produced an increase in cave excavation in the Tursi-Rabatana urban area. To reconstruct the extremely complex near-surface hypogeal environment excavated in the sandy layers, a geophysical investigation has been carried out, integrating the method of ERT (a multielectrode system with a Wenner-Schlumberger array layout) with the GPR (profiles were obtained using a SIR 2000-GSSI system equipped with two antennas of 400 and 200 MHz, connected by fiber-optic cables to the control unit) profiling. During the field survey, four ERT measurements and eight GPR profiles were carried out along the road network of Rabatana. The field survey permitted to evidence, for the Rabatana historical site, about 100 caves for which it is possible to see clear entrances, while at least 300 other caves are located in Tursi urban area and surroundings. This survey excludes all the caves and cisterns not directly ispectionable, but well showed in geophysical data. Since 1973, this site was subjected to the evacuation of its inhabitants in a new urban site due to catastrophic landslides caused by intense rainfalls that occurred on January 1972. Starting from 1974, the Rabatana has been almost completely deserted. Recently, a renewed interest for this site has been developed to recover the historical center, removing the current constraint of total evacuation. However at present, the site is still characterized by a particular morphological history and environmental factors that generate widespread risk conditions for the inhabitants and built-up areas. Morphological evolution of the sandy hillslopes on which Tursi town rises is characterized by very intense erosive phenomena such as landslides, deep gullies, rills, and piping, which affect the whole perimeter of urban settlements and threaten the conservation of these sites. From the point of view of the process of physical degradation, the sandy facies are characterized by desiccation cracks to which the piping erosion and detachment blocks along the slopes are closely linked. In some cases large voids do not develop, but seepage erosion and running sand cause morphologically similar surface collapse phenomena (sinkholes). Outlets spreading can cause landslide phenomena (rockfall and toppling) along the steep sandy-clayey slopes. The secular multilevel cave excavation, developed along several fronts beneath the urban area, accelerated the pre-existing morphological processes acting on this site, favouring the water infiltration and subsurface erosional phenomena, characterized by widespread surface piping erosion of sandy bodies. Moreover, climate analysis carried out for the last century showed an increasing trend in rainfall intensity over short durations, which also induced an increase in hazard conditions of the slopes. All the natural and anthropic conditions described above show as a deep knowledge of cave distribution and their geometry is the basis for a good urban planning to apply in historical site particularly vulnerable; it shows also as the integrated near surface geophysics techniques can powerfully contribute to acquire useful information to mitigate the anthropic risk and preserve the historical-monumental heritage.

Description of Dogs and Owners in Outdoor Built-Up Areas and Their More-Than-Human Issues

NASA Astrophysics Data System (ADS)

Gaunet, Florence; Pari-Perrin, Elodie; Bernardin, Geneviève

2014-09-01

Tensions are generated by the inevitable presence of dogs accompanying humans in cities. Built-up outdoor areas, spaces that are "in between" the home and dog parks, are widely frequented by dogs and their owners. The present case study, performed in Lyon (France), is the first to provide a description of these dyads in areas that vary according to terrain, district, dog legislation and use in three areas: a busy street where dogs are allowed and a park and a square where dogs are forbidden. Dog-owner profiles were identified. They adjusted their presence differently across areas and according to anthropogenic and ecological pressures, such as day of the week, time of day, weather, frequentation, and legislation. They mutually adapted their behaviors. Interactions between dogs or owners and other social agents were few; dogs primarily sniffed and urinated. There was little barking, no aggression, minor impact on the environment, and, despite instances of dogs appropriating forbidden areas and dogs off their leashes, the dogs seemed to go virtually unnoticed. The study shows how the need for more-than-human areas is evident in outdoor built-up areas (for instance, the results on types of interaction and activity across areas, absence of a leash, and appropriation of forbidden areas) as well as how the cultural and natural aspects of dogs play out. The results suggest that dog regulations should be adjusted in outdoor built-up areas and that dog parks should be developed.

The impact of extensive green roofs on the improvement of thermal performance for urban areas in Mediterranean climate with reference to the city of Jijel in Algeria

NASA Astrophysics Data System (ADS)

Lehtihet, M. C.; Bouchair, A.

2018-05-01

Buildings with dark surfaces, concrete and pavement, needed for the expansion of cities, absorb huge amounts of heat, increasing the mean radiant temperatures of urban areas and offer significant potential for urban heat island (UHI) effect. The purpose of this work is to investigate the impact of green roofs on the improvement of urban heat performance in Mediterranean climate. A field investigation is carried out using two large-scale modules built in the city of Jijel in the north of Algeria. The first is a bare reinforced concrete slab whereas the second is covered with ivy plants. The experimental site, the air and surface temperature parameters and the various measurement points at the level of the modules are chosen. Measurements are performed using thermo-hygrometer, surface sensors and data acquisition apparatus. The results show that green roofs can be a potential mean of improving the thermal performance of the surrounding microclimate and energy performance of buildings in an urban area. The green roof could be an encouraging strategy against urban heat island effect not only for Mediterranean cities but also for other areas.

The Dynamics of Population, Built-up Areas and their Evolving Associations in Gridded Population across Time and Space

NASA Astrophysics Data System (ADS)

Stevens, F. R.; Gaughan, A. E.; Tatem, A. J.; Linard, C.; Sorichetta, A.; Nieves, J. J.; Reed, P.

2017-12-01

Gridded population data is commonly used to understand the `now' of hazard risk and mitigation management, health and disease modelling, and global change-, economic-, environmental-, and sustainability-related research. But to understand how human population change at local to global scales influences and is influenced by environmental changes requires novel ways of treating data and statistically describing associations of measured population counts with associated covariates. One of the most critical components in such gridded estimates is the relationship between built-up areas and population located in these areas. This relationship is rarely static and accurately estimating changes in built-areas through time and the changing human population around them is critical when applying gridded population datasets in studies of other environmental change. The research presented here discusses these issues in the context of multitemporal, gridded population data, using new technologies and sources of remotely-sensed and modeled built-up areas. We discuss applications of these data in environmental analyses and intercomparisons with other such data across scales.

[Evaluation of perceptions of physical activity related built environment among urban adults with different characteristics in Hangzhou].

PubMed

Ren, Yanjun; Liu, Qingmin; Cao, Chengjian; Su, Meng; Lyu, Jun; Li, Liming

2015-10-01

To understand the perceptions of physical activity-related built environment among urban adults in Hangzhou. A face-to-face interview was conducted among the urban residents aged 25-59 years selected through multistage stratified random sampling in Hangzhou in 2012. The Neighborhood Environment Walkability Scale-Abbreviated (NEWS-A) was used to assess the perception of built environment among residents, including residential building density, the diversities of stores, facilities and others, the accessibility to public service, the street connectivity, walking/cycling facilities, aesthetics, traffic safety, and public security. The multilevel logistic regression model was used to assess the demographic characteristics, BMI and other factors' influence on people's perceptions. Among 1 362 local residents surveyed, no sex, martial status and occupation specific significant differences in the perception of built environment were found. After adjusting other factors, the age group 45-59 years was positively related to the score of street connectivity (OR=2.02, 95% CI: 1.30-3.15). The educational level of college or higher was positively associated with the score of residential building density (OR=1.97, 95% CI: 1.29-3.00) but negatively associated with the score of facility variety (OR=0.65, 95% CI: 0.43-0.97). Overweight or obesity was negatively related to the scores of walking/cycling ways (OR=0.67, 95%CI: 0.48-0.95) and public security (OR=0.75, 95% CI: 0.57-0.99). Compared with the class I residential area, the people in class III residential area had lower perception scores on facility diversity (OR=0.11, 95% CI: 0.04-0.30), accessibility to public service (OR=0.33, 95% CI: 0.11-0.95), street connectivity (OR=0.30, 95% CI: 0.11-0.86) and traffic safety (OR=0.39, 95% CI: 0.17-0.91). The perceptions of physical activity-related built environment was associated with age, educational level, BMI and residential area. The personal characteristics should be considered while performing environment intervention on physical activity.

Integrating local urban climate modelling and mobile sensor data for personal exposure assessments in the context of urban heat island effect

NASA Astrophysics Data System (ADS)

Ueberham, Maximilian; Hertel, Daniel; Schlink, Uwe

2017-04-01

Deeper knowledge about urban climate conditions is getting more important in the context of climate change, urban population growth, urban compaction and continued surface sealing. Especially the urban heat island effect (UHI) is one of the most significant human induced alterations of Earth's surface climate. According to this the appearance frequency of heat waves in cities will increase with deep impacts on personal thermal comfort, human health and local residential quality of citizens. UHI can be very heterogenic within a city and research needs to focus more on the neighborhood scale perspective to get further insights about the heat burden of individuals. However, up to now, few is known about local thermal environmental variances and personal exposure loads. To monitor these processes and the impact on individuals, improved monitoring approaches are crucial, complementing data recorded at conventional fixed stations. Therefore we emphasize the importance of micro-meteorological modelling and mobile measurements to shed new light on the nexus of urban human-climate interactions. Contributing to this research we jointly present the approaches of our two PhD-projects. Firstly we illustrate on the basis of an example site, how local thermal conditions in an urban district can be simulated and predicted by a micro-meteorological model. Secondly we highlight the potentials of personal exposure measurements based on an evaluation of mobile micro-sensing devices (MSDs) and analyze and explain differences between model predictions and mobile records. For the examination of local thermal conditions we calculated ENVI-met simulations within the "Bayerischer Bahnhof" quarter in Leipzig (Saxony, Germany; 51°20', 12°22'). To accomplish the maximum temperature contrasts within the diverse built-up structures we chose a hot summer day (25 Aug 2016) under autochthonous weather conditions. From these simulations we analyzed a UHI effect between the model core (urban area) and the surrounding nesting area (rural area). Preparing for the outdoor application of mobile MSDs we tested their accuracy and performance between several MSDs and reliable sophisticated devices under laboratory conditions. We found that variations mainly depend on the device design and technology (e.g. active/passive ventilation). The standard deviation of the temperature records was quite stable over the whole range of values and the MSDs proved to be applicable for the purpose of our study. In conclusion the benefit of integrating mobile data and micrometeorological predictions is manifold. Mobile data can be used for the investigation of personal exposure in the context of heat stress and for the verification and training of micrometeorological models. Otherwise, model predictions can identify local areas of special climate interest where additional mobile measurements would be beneficial to provide new information for mitigation and adaptation actions.

Urban rainfall monitoring with crowdsourced automatic weather stations in Amsterdam

NASA Astrophysics Data System (ADS)

de Vos, Lotte; Leijnse, Hidde; Overeem, Aart; Uijlenhoet, Remko

2017-04-01

The high density of built-up areas and resulting imperviousness of the land surface makes urban areas vulnerable to extreme rainfall, which can lead to considerable damage. In order to design and manage cities to be able to deal with the growing number of extreme rainfall events, rainfall data is required at higher temporal and spatial resolutions than those needed for rural catchments. However, the density of operational rainfall monitoring networks managed by local or national authorities is typically low in urban areas. A growing number of automatic personal weather stations (PWSs) link rainfall measurements to online platforms. Here, we examine the potential of such crowdsourced datasets for obtaining the desired resolution and quality of rainfall measurements for the capital of the Netherlands. Data from 63 stations in Amsterdam (˜575 km2}) that measure rainfall over at least 4 months in a 17-month period are evaluated. In addition, a detailed assessment is made of three Netatmo stations, the largest contributor to this dataset, in an experimental set-up. The sensor performance in the experimental set-up and the density of the PWS-network are promising. However, features in the online platforms, like rounding and thresholds, cause changes from the original time series, resulting in considerable errors in the datasets obtained. These errors are especially large during low intensity rainfall, although they can be reduced by accumulating rainfall over longer intervals. Accumulation improves the correlation coefficient with gauge-adjusted radar data from 0.48 at 5 min intervals to 0.60 at hourly intervals. Spatial rainfall correlation functions derived from PWS data show much more small-scale variability than those based on gauge-adjusted radar data and those found in similar research using dedicated rain gauge networks. This can largely be attributed to the noise in the PWS data resulting from both the measurement setup and the processes occurring in the data transfer to the online PWS-platform. A double mass comparison with gauge-adjusted radar data shows that the median of the stations resembles the rainfall reference better than the real-time (unadjusted) radar product. Averaging nearby raw PWS measurements further improves the match with gauge-adjusted radar data in that area. These results confirm that the growing number of internet-connected PWSs could successfully be used for urban rainfall monitoring.

Challenges for Schools in Communities with Internal Migration Flows: Evidence from Turkey

ERIC Educational Resources Information Center

Akar, Hanife

2010-01-01

Turkey is a country that has experienced and continues to experience a dramatic degree of both rural-to-urban and inter-regional internal migration. Migrants tend to settle in "gecekondu" areas in either established inner-city neighborhoods or in newer squatter settlements built on undeveloped land bordering rural areas on the urban…

Evaluation of urban flood damages in climate and land use changes: Case Studies from Southeast Asia

NASA Astrophysics Data System (ADS)

Kefi, M.; Binaya, M. K.; Kumar, P.; Fukushi, K.

2017-12-01

Urbanization, changes in land use and global warming increase the threat of natural disasters such as flooding. In recent decades, it was observed a rise of intensity and frequency of flood events. The exposure both of people and the national economy to flood hazards is amplified and can induce serious economic and social damages. For this reason, local governments adopted several strategies to cope with flood risk in urban areas in particular, but a better comprehension of the flood hazard factors may enhance the efficiency of mitigating measures overall. For this research, a spatial analysis is applied to estimate future direct flood damage for 2030 in three Southeast Asian megacities: Jakarta (Indonesia), Metro-Manila (Philippines) and Hanoi (Vietnam). This comprehensive method combined flood characteristics (flood depth) obtained from flood simulation using FLO-2D, land use generated from supervised classification and remote sensing products, property value of affected buildings and flood damage rate derived from flood depth function. This function is established based on field surveys with local people affected by past flood events. Additionally, two scenarios were analyzed to simulate the future conditions. The first one is related to climate change and it is based on several General Circulation Models (GCMs). However, the second one is establish to point out the effect of adaptation strategies. The findings shows that the climate change combined with the expansion of built-up areas increase the vulnerability of urban areas to flooding and the economic damage. About 16%, 8% and 19% of flood inundation areas are expected to increase respectively in Metro-Manila, Jakarta and Hanoi. However, appropriate flood control measures can be helpful to reduce the impact of natural disaster. Furthermore, flood damage maps are generated at a large scale, which can be helpful to local stakeholders when prioritizing their mitigation strategies on urban disaster resilience.

Analysis of potential urban unstable areas and landslide-induced damages on Volterra historical site through a remote sensing approach

NASA Astrophysics Data System (ADS)

Del Soldato, Matteo; Bianchini, Silvia; Nolesini, Teresa; Frodella, William; Casagli, Nicola

2017-04-01

Multisystem remote sensing techniques were exploited to provide a comprehensive overview of Volterra (Italy) site stability with regards to its landscape, urban fabric and cultural heritage. Interferometric Synthetic Aperture Radar (InSAR) techniques allow precise measurements of Earth surface displacement, as well as the detection of building deformations on large urban areas. In the field of cultural heritage conservation Infrared thermography (IRT) provides surface temperature mapping and therefore detects various potential criticalities, such as moisture, seepage areas, cracks and structural anomalies. Between winter 2014 and spring 2015 the historical center and south-western sectors of Volterra (Tuscany region, central Italy) were affected by instability phenomena. The spatial distribution, typology and effect on the urban fabrics of the landslide phenomena were investigated by analyzing the geological and geomorphological settings, traditional geotechnical monitoring and advanced remote sensing data such as Persistent Scatterers Interferometry (PSI). The ground deformation rates and the maximum settlement values derived from SAR acquisitions of historical ENVISAT and recent COSMO-SkyMed sensors, in 2003-2009 and 2010-2015 respectively, were compared with background geological data, constructive features, in situ evidences and detailed field inspections in order to classify landslide-damaged buildings. In this way, the detected movements and their potential correspondences with recognized damages were investigated in order to perform an assessment of the built-up areas deformations and damages on Volterra. The IRT technique was applied in order to survey the surface temperature of the historical Volterra wall-enclosure, and allowed highlighting thermal anomalies on this cultural heritage element of the site. The obtained results permitted to better correlate the landslide effects of the recognized deformations in the urban fabric, in order to provide useful information for future risk mitigation strategies to be planned by the local authorities and the involved technicians and conservators.

Microclimate Evaluation of the Hradec Králové City using HUMIDEX

NASA Astrophysics Data System (ADS)

Rožnovský, Jaroslav; Litschmann, Tomáš; Středová, Hana; Středa, Tomáš; Salaš, Petr; Horká, Marie

2017-09-01

Urban environment differs from the surrounding landscape in terms of the values of meteorological parameters. This is often referred to as the urban heat island (UHI), which in simple terms means higher air temperatures in cities. The cause of these changes lies in the different active surfaces in cities, which subsequently results in a different radiation balance. The higher temperatures, however, also affect the living conditions in the city and during very high temperature periods can have negative effects on the health of the city inhabitants. The results presented in this paper are based on measurements taken over several years at locations near Hradec Králové, which is surrounded by different surface areas. Environment analysis was performed using the Humidex index. The obtained results show that replacing green areas with built-up areas affects temperatures in the city, when air temperatures are very high they significantly increase the discomfort of the inhabitants. Differences in the frequency of discomfort levels are observed especially during periods of high temperatures, at lower temperatures these differences are not significant. Higher frequencies of discomfort are observed at locations with artificial surfaces (asphalt, cobblestones, concrete) and in closed spaces. In contrast, locations with lots of green areas almost always have the value of this index lower or more balanced. The results should therefore be a valid argument for maintaining and extending green areas in cities.

Historical GIS Data and Changes in Urban Morphological Parameters for the Analysis of Urban Heat Islands in Hong Kong

NASA Astrophysics Data System (ADS)

Peng, F.; Wong, M. S.; Nichol, J. E.; Chan, P. W.

2016-06-01

Rapid urban development between the 1960 and 2010 decades have changed the urban landscape and pattern in the Kowloon Peninsula of Hong Kong. This paper aims to study the changes of urban morphological parameters between the 1985 and 2010 and explore their influences on the urban heat island (UHI) effect. This study applied a mono-window algorithm to retrieve the land surface temperature (LST) using Landsat Thematic Mapper (TM) images from 1987 to 2009. In order to estimate the effects of local urban morphological parameters to LST, the global surface temperature anomaly was analysed. Historical 3D building model was developed based on aerial photogrammetry technique using aerial photographs from 1964 to 2010, in which the urban digital surface models (DSMs) including elevations of infrastructures and buildings have been generated. Then, urban morphological parameters (i.e. frontal area index (FAI), sky view factor (SVF)), vegetation fractional cover (VFC), global solar radiation (GSR), Normalized Difference Built-Up Index (NDBI), wind speed were derived. Finally, a linear regression method in Waikato Environment for Knowledge Analysis (WEKA) was used to build prediction model for revealing LST spatial patterns. Results show that the final apparent surface temperature have uncertainties less than 1 degree Celsius. The comparison between the simulated and actual spatial pattern of LST in 2009 showed that the correlation coefficient is 0.65, mean absolute error (MAE) is 1.24 degree Celsius, and root mean square error (RMSE) is 1.51 degree Celsius of 22,429 pixels.

Modeling the intraurban variation in nitrogen dioxide in urban areas in Kathmandu Valley, Nepal.

PubMed

Gurung, Anobha; Levy, Jonathan I; Bell, Michelle L

2017-05-01

With growing urbanization, traffic has become one of the main sources of air pollution in Nepal. Understanding the impact of air pollution on health requires estimation of exposure. Land use regression (LUR) modeling is widely used to investigate intraurban variation in air pollution for Western cities, but LUR models are relatively scarce in developing countries. In this study, we developed LUR models to characterize intraurban variation of nitrogen dioxide (NO 2 ) in urban areas of Kathmandu Valley, Nepal, one of the fastest urbanizing areas in South Asia. Over the study area, 135 monitoring sites were selected using stratified random sampling based on building density and road density along with purposeful sampling. In 2014, four sampling campaigns were performed, one per season, for two weeks each. NO 2 was measured using duplicate Palmes tubes at 135 sites, with additional information on nitric oxide (NO), NO 2 , and nitrogen oxide (NOx) concentrations derived from Ogawa badges at 28 sites. Geographical variables (e.g., road network, land use, built area) were used as predictor variables in LUR modeling, considering buffers 25-400m around each monitoring site. Annual average NO 2 by site ranged from 5.7 to 120ppb for the study area, with higher concentrations in the Village Development Committees (VDCs) of Kathmandu and Lalitpur than in Kirtipur, Thimi, and Bhaktapur, and with variability present within each VDC. In the final LUR model, length of major road, built area, and industrial area were positively associated with NO 2 concentration while normalized difference vegetation index (NDVI) was negatively associated with NO 2 concentration (R 2 =0.51). Cross-validation of the results confirmed the reliability of the model. The combination of passive NO 2 sampling and LUR modeling techniques allowed for characterization of nitrogen dioxide patterns in a developing country setting, demonstrating spatial variability and high pollution levels. Copyright © 2017 Elsevier Inc. All rights reserved.

Electrical imaging for localizing historical tunnels at an urban environment

NASA Astrophysics Data System (ADS)

Osella, Ana; Martinelli, Patricia; Grunhut, Vivian; de la Vega, Matías; Bonomo, Néstor; Weissel, Marcelo

2015-08-01

We performed a geophysical study at a historical site in Buenos Aires, Argentina, corresponding to the location of a Jesuit Mission established during the 17th century, remaining there until the 18th century. The site consisted of a church, cloisters, a school, orchards and a procurator’s office; also several tunnels were built, connecting the mission with different public buildings in the town. In the 19th century the Faculty of Sciences of the University of Buenos Aires was built in a sector of the site originally occupied by an orchard, functioning until its demolition in 1973. At present, this area is a cobbled square. With the aim of preserving and restoring the buried structures, work was carried out in this square looking for tunnels and remains of the basement of the old building. Considering the conductive features of the subsoil, mainly formed by clays and silt, the complex characteristics of the buried structures, and the urban localization of the study area with its consequent high level of environmental electromagnetic noise, we performed pre-feasibility studies to determine the usefulness of different geophysical methods. The best results were achieved from the geoelectrical method. Dipole-dipole profiles with electrode spacings of 1.5 and 3 m provided enough lateral and vertical resolution and the required penetration depth. Reliable data were obtained as long as the electrodes were buried at least 15 cm among the cobble stones. Nine 2D electrical resistivity tomographies were obtained by using a robust inversion procedure to reduce the effect of possible data outliers in the resulting models. The effect on these models of different error estimations was also analyzed. Then, we built up a pseudo-3D model by laterally interpolating the 2D inversion results. Finally, by correlating the resulting model with the original plans, the remains of the expected main structures embedded in the site were characterized. In addition, an anomaly was identified that indicates the presence of a tunnel not previously reported.

Earth Observations taken by the Expedition 27 Crew

NASA Image and Video Library

2011-05-16

ISS027-E-033889 (16 May 2011) --- Izmir Metropolitan Area, Izmir Province in Turkey is featured in this image photographed by an Expedition 27 crew member on the International Space Station. The metropolis of Izmir is located in the western Anatolia region of Turkey. It is the country’s third largest city in terms of population and the second largest port city (after Istanbul). The Izmir region has included urban areas for almost 3,500 years, and the ancient core of the metropolitan area was originally known as Smyrna. Due to its location on the Gulf of Izmir (lower left) with access to the Aegean Sea, Izmir (or Smyrna) has been an important Mediterranean Sea port for most of its history. This detailed photograph highlights the modern urban landscape of the Izmir metropolitan area. Today, the metropolitan area includes eleven districts, many of which were independent neighborhoods prior to agglomeration into “greater Izmir”. Densely built-up residential and commercial districts, characterized by gray to reddish gray rooftops occupy much of the central part of the image. Larger structures with bright white rooftops are indicative of commercial/industrial areas near the Izmir Port at left. Two large sport complexes, the Ataturk Stadium and Sirinyer Hippodrome (horse racing track) are clearly visible at upper left and right respectively. Numerous vegetated parks (green) are located throughout the area. In addition to being a major trade center, greater Izmir is a hub for regional tourism.

Extraction of Built-Up Areas Using Convolutional Neural Networks and Transfer Learning from SENTINEL-2 Satellite Images

NASA Astrophysics Data System (ADS)

Bramhe, V. S.; Ghosh, S. K.; Garg, P. K.

2018-04-01

With rapid globalization, the extent of built-up areas is continuously increasing. Extraction of features for classifying built-up areas that are more robust and abstract is a leading research topic from past many years. Although, various studies have been carried out where spatial information along with spectral features has been utilized to enhance the accuracy of classification. Still, these feature extraction techniques require a large number of user-specific parameters and generally application specific. On the other hand, recently introduced Deep Learning (DL) techniques requires less number of parameters to represent more abstract aspects of the data without any manual effort. Since, it is difficult to acquire high-resolution datasets for applications that require large scale monitoring of areas. Therefore, in this study Sentinel-2 image has been used for built-up areas extraction. In this work, pre-trained Convolutional Neural Networks (ConvNets) i.e. Inception v3 and VGGNet are employed for transfer learning. Since these networks are trained on generic images of ImageNet dataset which are having very different characteristics from satellite images. Therefore, weights of networks are fine-tuned using data derived from Sentinel-2 images. To compare the accuracies with existing shallow networks, two state of art classifiers i.e. Gaussian Support Vector Machine (SVM) and Back-Propagation Neural Network (BP-NN) are also implemented. Both SVM and BP-NN gives 84.31 % and 82.86 % overall accuracies respectively. Inception-v3 and VGGNet gives 89.43 % of overall accuracy using fine-tuned VGGNet and 92.10 % when using Inception-v3. The results indicate high accuracy of proposed fine-tuned ConvNets on a 4-channel Sentinel-2 dataset for built-up area extraction.

Urban vegetation and thermal patterns following city growth in different socio-economic contexts

NASA Astrophysics Data System (ADS)

Dronova, I.; Clinton, N.; Yang, J.; Radke, J.; Marx, S. S.; Gong, P.

2015-12-01

Urban expansion accompanied by losses of vegetated spaces and their ecological services raises significant concerns about the future of humans in metropolitan "habitats". Despite recent growth of urban studies globally, it is still not well understood how environmental effects of urbanization vary with the rate and socioeconomic context of development. Our study hypothesized that with urban development, spatial patterns of surface thermal properties and green plant cover would shift towards higher occurrence of relatively warmer and less vegetated spaces such as built-up areas, followed by losses of greener and cooler areas such as urban forests, and that these shifts would be more pronounced with higher rate of economic and/or population growth. To test these ideas, we compared 1992-2011 changes in remotely sensed patterns of green vegetation and surface temperature in three example cities that experienced peripheral growth under contrasting socio-economic context - Dallas, TX, USA, Beijing, China and Kyiv, Ukraine. To assess their transformation, we proposed a metric of thermal-vegetation angle (TVA) estimated from per-pixel proxies of vegetation greenness and surface temperature from Landsat satellite data and examined changes in TVA distributions within each city's core and two decadal zones of peripheral sprawl delineated from nighttime satellite data. We found that higher economic and population growth were coupled with more pronounced changes in TVA distributions, and more urbanized zones often exhibited higher frequencies of warmer, less green than average TVA values with novel patterns such as "cooler" clusters of building shadows. Although greener and cooler spaces generally diminished with development, they remained relatively prevalent in low-density residential areas of Dallas and peripheral zones of Kyiv with exurban subsistence farming. Overall, results indicate that the effects of modified green space and thermal patterns within growing cities highly vary depending on economy, population trends and historical legacies of planned green spaces. Remote sensing-based metrics such as TVA facilitate their comparisons and offer useful strategies to cost-effectively monitor urban transformation and inform more explicit environmental modeling of cities in the future.

[Capacity of extensive green roof to retain rainwater runoff in hot and humid region.

PubMed

Liu, Ming Xin; Dai, Se Ping; Zhou, Tian Yang; Ruan, Lin; Zhang, Qiao Song

2017-02-01

The water logging has become the environmental problem of major cities with the sharp increase of impermeable urban pavement as the contributing cause. Abroad, the green roof has been widely used as a practical measure to intercept rainwater, yet the capacity of green roof to retain rainwater varies with climate conditions. As the hot and humid climate zone features high temperature, humidity and precipitation, it is meaningful to study the capacity of green roof to retain rainwater under such climatic condition. In this research, 3 plat forms were set up in Guangzhou in rainy and hot summer to test the capability of simple green roof to retain rainwater runoff, and the efficiency of green roof to retain rainwater under local climate conditions was worked out based on the meteorological observation and data measurement during the 13-month test period. The results showed that the simple green roof with a substrate thickness of 30, 50 and 70 mm could retain 27.2%, 30.9% and 32.1% of precipitation and reduce the average peak value by 18.9%, 26.2% and 27.7%, respectively. Given an urban built-up area of 1035.01 km 2 in Guangzhou and a roof area percentage of approximately 37.3% and assuming the green roofs with 30 mm-thick substrate were applied within the area, the light, medium and heavy rain could be delayed at 72.8%, 22.6% and 17.4%, respectively. Accordingly, the rainwater retained could reach up to 14317×10 4 m 3 . It suggested the great potential of the simple green roof in retaining rainwater. The research could serve as reference for the hot and humid climate zone to alleviate water logging and visualize sponge city construction.

Urban air quality

NASA Astrophysics Data System (ADS)

Fenger, Jes

Since 1950 the world population has more than doubled, and the global number of cars has increased by a factor of 10. In the same period the fraction of people living in urban areas has increased by a factor of 4. In year 2000 this will amount to nearly half of the world population. About 20 urban regions will each have populations above 10 million people. Seen over longer periods, pollution in major cities tends to increase during the built up phase, they pass through a maximum and are then again reduced, as abatement strategies are developed. In the industrialised western world urban air pollution is in some respects in the last stage with effectively reduced levels of sulphur dioxide and soot. In recent decades however, the increasing traffic has switched the attention to nitrogen oxides, organic compounds and small particles. In some cities photochemical air pollution is an important urban problem, but in the northern part of Europe it is a large-scale phenomenon, with ozone levels in urban streets being normally lower than in rural areas. Cities in Eastern Europe have been (and in many cases still are) heavily polluted. After the recent political upheaval, followed by a temporary recession and a subsequent introduction of new technologies, the situation appears to improve. However, the rising number of private cars is an emerging problem. In most developing countries the rapid urbanisation has so far resulted in uncontrolled growth and deteriorating environment. Air pollution levels are here still rising on many fronts. Apart from being sources of local air pollution, urban activities are significant contributors to transboundary pollution and to the rising global concentrations of greenhouse gasses. Attempts to solve urban problems by introducing cleaner, more energy-efficient technologies will generally have a beneficial impact on these large-scale problems. Attempts based on city planning with a spreading of the activities, on the other hand, may generate more traffic and may thus have the opposite effect.

Performance of GPS-devices for environmental exposure assessment.

PubMed

Beekhuizen, Johan; Kromhout, Hans; Huss, Anke; Vermeulen, Roel

2013-01-01

Integration of individual time-location patterns with spatially resolved exposure maps enables a more accurate estimation of personal exposures to environmental pollutants than using estimates at fixed locations. Current global positioning system (GPS) devices can be used to track an individual's location. However, information on GPS-performance in environmental exposure assessment is largely missing. We therefore performed two studies. First, a commute-study, where the commute of 12 individuals was tracked twice, testing GPS-performance for five transport modes and two wearing modes. Second, an urban-tracking study, where one individual was tracked repeatedly through different areas, focused on the effect of building obstruction on GPS-performance. The median error from the true path for walking was 3.7 m, biking 2.9 m, train 4.8 m, bus 4.9 m, and car 3.3 m. Errors were larger in a high-rise commercial area (median error=7.1 m) compared with a low-rise residential area (median error=2.2 m). Thus, GPS-performance largely depends on the transport mode and urban built-up. Although ~85% of all errors were <10 m, almost 1% of the errors were >50 m. Modern GPS-devices are useful tools for environmental exposure assessment, but large GPS-errors might affect estimates of exposures with high spatial variability.

Using multivariate analyses and GIS to identify pollutants and their spatial patterns in urban soils in Galway, Ireland.

PubMed

Zhang, Chaosheng

2006-08-01

Galway is a small but rapidly growing tourism city in western Ireland. To evaluate its environmental quality, a total of 166 surface soil samples (0-10 cm depth) were collected from parks and grasslands at the density of 1 sample per 0.25 km2 at the end of 2004. All samples were analysed using ICP-AES for the near-total concentrations of 26 chemical elements. Multivariate statistics and GIS techniques were applied to classify the elements and to identify elements influenced by human activities. Cluster analysis (CA) and principal component analysis (PCA) classified the elements into two groups: the first group predominantly derived from natural sources, the second being influenced by human activities. GIS mapping is a powerful tool in identifying the possible sources of pollutants. Relatively high concentrations of Cu, Pb and Zn were found in the city centre, old residential areas, and along major traffic routes, showing significant effects of traffic pollution. The element As is enriched in soils of the old built-up areas, which can be attributed to coal and peat combustion for home heating. Such significant spatial patterns of pollutants displayed by urban soils may imply potential health threat to residents of the contaminated areas of the city.

An approach to analyzing the intensity of the daytime surface urban heat island effect at a local scale.

PubMed

Xu, Shenlai

2009-04-01

A landscape index LI is proposed to evaluate the intensity of the daytime surface urban heat island (SUHI) effect at a local scale. Three aspects of this landscape index are crucial: the source landscape, the sink landscape, and the contribution of source and sink landscapes to the intensity of the SUHI. Source and sink landscape types are identified using the thermo-band of Landsat 7 with a spatial resolution of 60 m, along with appropriate threshold values for the Normalized Difference Vegetation Index, Modified Normalized Difference Water Index, and Normalized Difference Built-up Index. The landscape index was defined as the ratio of the contributions of the source and sink landscapes to the intensity of the SUHI. The intensity of the daytime SUHI is assessed with the help of the landscape index. Our analysis indicates the landscape index can be used to evaluate and compare the intensity of the daytime SUHI for different areas.

Reduced wind speed improves plant growth in a desert city.

PubMed

Bang, Christofer; Sabo, John L; Faeth, Stanley H

2010-06-10

The often dramatic effects of urbanization on community and ecosystem properties, such as primary productivity, abundances, and diversity are now well-established. In most cities local primary productivity increases and this extra energy flows upwards to alter diversity and relative abundances in higher trophic levels. The abiotic mechanisms thought to be responsible for increases in urban productivity are altered temperatures and light regimes, and increased nutrient and water inputs. However, another abiotic factor, wind speed, is also influenced by urbanization and well known for altering primary productivity in agricultural systems. Wind effects on primary productivity have heretofore not been studied in the context of urbanization. We designed a field experiment to test if increased plant growth often observed in cities is explained by the sheltering effects of built structures. Wind speed was reduced by protecting Encelia farinosa (brittlebush) plants in urban, desert remnant and outlying desert localities via windbreaks while controlling for water availability and nutrient content. In all three habitats, we compared E. farinosa growth when protected by experimental windbreaks and in the open. E. farinosa plants protected against ambient wind in the desert and remnant areas grew faster in terms of biomass and height than exposed plants. As predicted, sheltered plants did not differ from unprotected plants in urban areas where wind speed is already reduced. Our results indicate that reductions in wind speed due to built structures in cities contribute to increased plant productivity and thus also to changes in abundances and diversity of higher trophic levels. Our study emphasizes the need to incorporate wind speed in future urban ecological studies, as well as in planning for green space and sustainable cities.

Remotely-Sensed Urban Wet-Landscapes AN Indicator of Coupled Effects of Human Impact and Climate Change

NASA Astrophysics Data System (ADS)

Ji, Wei

2016-06-01

This study proposes the concept of urban wet-landscapes (loosely-defined wetlands) as against dry-landscapes (mainly impervious surfaces). The study is to examine whether the dynamics of urban wet-landscapes is a sensitive indicator of the coupled effects of the two major driving forces of urban landscape change - human built-up impact and climate (precipitation) variation. Using a series of satellite images, the study was conducted in the Kansas City metropolitan area of the United States. A rule-based classification algorithm was developed to identify fine-scale, hidden wetlands that could not be appropriately detected based on their spectral differentiability by a traditional image classification. The spatial analyses of wetland changes were implemented at the scales of metropolitan, watershed, and sub-watershed as well as based on the size of surface water bodies in order to reveal urban wetland change trends in relation to the driving forces. The study identified that wet-landscape dynamics varied in trend and magnitude from the metropolitan, watersheds, to sub-watersheds. The study also found that increased precipitation in the region in the past decades swelled larger wetlands in particular while smaller wetlands decreased mainly due to human development activities. These findings suggest that wet-landscapes, as against the dry-landscapes, can be a more effective indicator of the coupled effects of human impact and climate change.

Land Use and Land Cover Changes and Urban Sprawl in Riyadh, Saudi Arabia: AN Analysis Using Multi-Temporal Landsat Data and SHANNON'S Entropy Index

NASA Astrophysics Data System (ADS)

Rahman, M. T.

2016-06-01

The city of Riyadh, Saudi Arabia has experienced rapid population growth and urban expansion over the past several decades. Due to such growth, the capital city faces many short and long-term social and environmental consequences. In order to monitor and mitigate some of these consequences, it is essential to examine the past changes and historical growth of the city. It is also essential to measure its urban sprawl over the past few decades. The objective of this study is to fulfil these goals. It does so by first examining the historical growth of the city of Riyadh. To do so, Landsat data over the past two and half decades are classified using a combination of supervised and unsupervised classification techniques. Based on the classification results, the study then uses Shannon's Entropy to measure the urban sprawl in the city. The results show that from 1990-2009, the urban built-up area of the city has increased by 90% in the western, south-eastern, and northern parts. The Shannon's entropy values show that the city is dispersing towards the outskirts of the city. The results from this study will assist city planners and government officials to plan, reduce, and perhaps mitigate some of the social and environmental consequences and enable the growth of the city in a sustainable manner in the near future.

Using High Resolution Commercial Satellite Imagery to Quantify Spatial Features of Urban Areas and their Relationship to Quality of Life Indicators in Accra, Ghana

NASA Astrophysics Data System (ADS)

Sandborn, A.; Engstrom, R.; Yu, Q.

2014-12-01

Mapping urban areas via satellite imagery is an important task for detecting and anticipating land cover and land use change at multiple scales. As developing countries experience substantial urban growth and expansion, remotely sensed based estimates of population and quality of life indicators can provide timely and spatially explicit information to researchers and planners working to determine how cities are changing. In this study, we use commercial high spatial resolution satellite imagery in combination with fine resolution census data to determine the ability of using remotely sensed data to reveal the spatial patterns of quality of life in Accra, Ghana. Traditionally, spectral characteristics are used on a per-pixel basis to determine land cover; however, in this study, we test a new methodology that quantifies spatial characteristics using a variety of spatial features observed in the imagery to determine the properties of an urban area. The spatial characteristics used in this study include histograms of oriented gradients, PanTex, Fourier transform, and line support regions. These spatial features focus on extracting structural and textural patterns of built-up areas, such as homogeneous building orientations and straight line indices. Information derived from aggregating the descriptive statistics of the spatial features at both the fine-resolution census unit and the larger neighborhood level are then compared to census derived quality of life indicators including information about housing, education, and population estimates. Preliminary results indicate that there are correlations between straight line indices and census data including available electricity and literacy rates. Results from this study will be used to determine if this methodology provides a new and improved way to measure a city structure in developing cities and differentiate between residential and commercial land use zones, as well as formal versus informal housing areas.

Impact evaluation of green-grey infrastructure interaction on built-space integrity: an emerging perspective to urban ecosystem service.

PubMed

Tiwary, Abhishek; Kumar, Prashant

2014-07-15

This paper evaluates the role of urban green infrastructure (GI) in maintaining integrity of built-space. The latter is considered as a lateral ecosystem function, worth including in future assessments of integrated ecosystem services. The basic tenet is that integrated green-grey infrastructures (GGIs) would have three influences on built-spaces: (i) reduced wind withering from flow deviation; (ii) reduced material corrosion/degeneration from pollution removal; and (iii) act as a biophysical buffer in altering the micro-climate. A case study is presented, combining the features of computational fluid dynamics (CFD) in micro-environmental modelling with the emerging science on interactions of GGIs. The coupled seasonal dynamics of the above three effects are assessed for two building materials (limestone and steel) using the following three scenarios: (i) business as usual (BAU), (ii) summer (REGEN-S), and (iii) winter (REGEN-W). Apparently, integrated ecosystem service from green-grey interaction, as scoped in this paper, has strong seasonal dependence. Compared to BAU our results suggest that REGEN-S leads to slight increment in limestone recession (<10%), mainly from exacerbation in ozone damage, while large reduction in steel recession (up to 37%) is observed. The selection of vegetation species, especially their bVOC emission potential and seasonal foliage profile, appears to play a vital role in determining the impact GI has on the integrity of the neighbouring built-up environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Temporal trend of green space coverage in China and its relationship with urbanization over the last two decades.

PubMed

Zhao, Juanjuan; Chen, Shengbin; Jiang, Bo; Ren, Yin; Wang, Hua; Vause, Jonathan; Yu, Haidong

2013-01-01

Irrespective of which side is taken in the densification-sprawl debate, insights into the relationship between urban green space coverage and urbanization have been recognized as essential for guiding sustainable urban development. However, knowledge of the relationships between socio-economic variables of urbanization and long-term green space change is still limited. In this paper, using simple regression, hierarchical partitioning and multi-regression, the temporal trend in green space coverage and its relationship with urbanization were investigated using data from 286 cities between 1989 and 2009, covering all provinces in mainland China with the exception of Tibet. We found that: [1] average green space coverage of cities investigated increased steadily from 17.0% in 1989 to 37.3% in 2009; [2] cities with higher recent green space coverage also had relatively higher green space coverage historically; [3] cities in the same region exhibited similar long-term trends in green space coverage; [4] eight of the nine variables characterizing urbanization showed a significant positive linear relationship with green space coverage, with 'per capita GDP' having the highest independent contribution (24.2%); [5] among the climatic and geographic factors investigated, only mean elevation showed a significant effect; and [6] using the seven largest contributing individual factors, a linear model to predict variance in green space coverage was constructed. Here, we demonstrated that green space coverage in built-up areas tended to reflect the effects of urbanization rather than those of climatic or geographic factors. Quantification of the urbanization effects and the characteristics of green space development in China may provide a valuable reference for research into the processes of urban sprawl and its relationship with green space change. Copyright © 2012 Elsevier B.V. All rights reserved.

Global scenarios of urban density and its impacts on building energy use through 2050

PubMed Central

Güneralp, Burak; Zhou, Yuyu; Ürge-Vorsatz, Diana; Gupta, Mukesh; Yu, Sha; Patel, Pralit L.; Fragkias, Michail; Li, Xiaoma; Seto, Karen C.

2017-01-01

Although the scale of impending urbanization is well-acknowledged, we have a limited understanding of how urban forms will change and what their impact will be on building energy use. Using both top-down and bottom-up approaches and scenarios, we examine building energy use for heating and cooling. Globally, the energy use for heating and cooling by the middle of the century will be between 45 and 59 exajoules per year (corresponding to an increase of 7–40% since 2010). Most of this variability is due to the uncertainty in future urban densities of rapidly growing cities in Asia and particularly China. Dense urban development leads to less urban energy use overall. Waiting to retrofit the existing built environment until markets are ready in about 5 years to widely deploy the most advanced renovation technologies leads to more savings in building energy use. Potential for savings in energy use is greatest in China when coupled with efficiency gains. Advanced efficiency makes the least difference compared with the business-as-usual scenario in South Asia and Sub-Saharan Africa but significantly contributes to energy savings in North America and Europe. Systemic efforts that focus on both urban form, of which urban density is an indicator, and energy-efficient technologies, but that also account for potential co-benefits and trade-offs with human well-being can contribute to both local and global sustainability. Particularly in growing cities in the developing world, such efforts can improve the well-being of billions of urban residents and contribute to mitigating climate change by reducing energy use in urban areas. PMID:28069957

Mortality and nursing home placement of dementia patients in rural and urban areas: a cohort study from the Swedish Dementia Registry.

PubMed

Roheger, Mandy; Zupanic, Eva; Kåreholt, Ingemar; Religa, Dorota; Kalbe, Elke; Eriksdotter, Maria; Garcia-Ptacek, Sara

2018-04-14

Life in rural and urban areas differs in regard to social support and health care. Our aim was to examine the association between nursing home placement and survival of patients with dementia living in urban vs. rural areas. We performed a longitudinal cohort study of patients with dementia at time of diagnosis (n = 58 154) and at first follow-up (n = 21 522) including patients registered from 2007 through 2014 in the Swedish Dementia Registry (SveDem). Descriptive statistics are shown. Odds ratios with 95% CI are presented for nursing home placement and hazard ratios for survival analysis. In age- and sex-adjusted analyses, patients living in urban areas were more likely to be in nursing homes at the time of dementia diagnosis than patients in rural areas (1.49, 95% CI: 1.29-1.73). However, there were no differences in rural vs urban areas in either survival after dementia diagnosis (urban: 0.99, 0.95-1.04, intermediate: 1.00, 0.96-1.04), or nursing home placement at first follow-up (urban: 1.00, 0.88-1.13; intermediate: 0.95, 0.85-1.06). Persons with dementia living in rural areas are less likely to live in a nursing home than their urban counterparts at the time of dementia diagnosis, but these differences disappear by the time of first follow-up. Differences in access to nursing homes between urban and rural settings could explain these findings. Results should be considered in the future healthcare decisions to ensure equality of health care across rural and urban areas. © 2018 The Authors. Scandinavian Journal of Caring Sciences published by John Wiley & Sons Ltd on behalf of Nordic College of Caring Science.

Design component method for sensitivity analysis of built-up structures

NASA Technical Reports Server (NTRS)

Choi, Kyung K.; Seong, Hwai G.

1986-01-01

A 'design component method' that provides a unified and systematic organization of design sensitivity analysis for built-up structures is developed and implemented. Both conventional design variables, such as thickness and cross-sectional area, and shape design variables of components of built-up structures are considered. It is shown that design of components of built-up structures can be characterized and system design sensitivity expressions obtained by simply adding contributions from each component. The method leads to a systematic organization of computations for design sensitivity analysis that is similar to the way in which computations are organized within a finite element code.

Of Harlem and Harlan: Non-Metropolitan People as a Minority Group. Revised.

ERIC Educational Resources Information Center

Roman, John H.

Prejudice built up against the rural citizen and his situation is exemplified in the stereotyping inherent in the pejorative terms "pastoral", "bucolic", "hick", etc., and romantic turn-of-the-century debate over whether "modern degeneracy" should be considered urban- or rural-centered. Such holdover…

Noise levels associated with urban land use.

PubMed

King, Gavin; Roland-Mieszkowski, Marek; Jason, Timothy; Rainham, Daniel G

2012-12-01

Recent trends towards the intensification of urban development to increase urban densities and avoid sprawl should be accompanied by research into the potential for related health impacts from environmental exposure. The objective of the current study was to examine the effect of the built environment and land use on levels of environmental noise. Two different study areas were selected using a combination of small area census geography, land use information, air photography, and ground-truthing. The first study area represented residential land use and consisted of two- to three-story single-family homes. The second study area was characteristic of mixed-use urban planning with apartment buildings as well as commercial and institutional development. Study areas were subdivided into six grids, and a location was randomly selected within each grid for noise monitoring. Each location was sampled four times over a 24-h day, resulting in a total of 24 samples for each of the two areas. Results showed significant variability in noise within study areas and significantly higher levels of environmental noise in the mixed-use area. Both study areas exceeded recommended noise limits when evaluated against World Health Organization guidelines and yielded average noise events values in the moderate to serious annoyance range with the potential to obscure normal conversation and cause sleep disturbance.

The extent of shifts in vegetation phenology between rural and urban areas within a human-dominated region.

PubMed

Dallimer, Martin; Tang, Zhiyao; Gaston, Kevin J; Davies, Zoe G

2016-04-01

Urbanization is one of the major environmental challenges facing the world today. One of its particularly pressing effects is alterations to local and regional climate through, for example, the Urban Heat Island. Such changes in conditions are likely to have an impact on the phenology of urban vegetation, which will have knock-on implications for the role that urban green infrastructure can play in delivering multiple ecosystem services. Here, in a human-dominated region, we undertake an explicit comparison of vegetation phenology between urban and rural zones. Using satellite-derived MODIS-EVI data from the first decade of the 20th century, we extract metrics of vegetation phenology (date of start of growing season, date of end of growing season, and length of season) for Britain's 15 largest cities and their rural surrounds. On average, urban areas experienced a growing season 8.8 days longer than surrounding rural zones. As would be expected, there was a significant decline in growing season length with latitude (by 3.4 and 2.4 days/degree latitude in rural and urban areas respectively). Although there is considerable variability in how phenology in urban and rural areas differs across our study cities, we found no evidence that built urban form influences the start, end, or length of the growing season. However, the difference in the length of the growing season between rural and urban areas was significantly negatively associated with the mean disposable household income for a city. Vegetation in urban areas deliver many ecosystem services such as temperature mitigation, pollution removal, carbon uptake and storage, the provision of amenity value for humans and habitat for biodiversity. Given the rapid pace of urbanization and ongoing climate change, understanding how vegetation phenology will alter in the future is important if we wish to be able to manage urban greenspaces effectively.

Multi-Feature Based Information Extraction of Urban Green Space Along Road

NASA Astrophysics Data System (ADS)

Zhao, H. H.; Guan, H. Y.

2018-04-01

Green space along road of QuickBird image was studied in this paper based on multi-feature-marks in frequency domain. The magnitude spectrum of green along road was analysed, and the recognition marks of the tonal feature, contour feature and the road were built up by the distribution of frequency channels. Gabor filters in frequency domain were used to detect the features based on the recognition marks built up. The detected features were combined as the multi-feature-marks, and watershed based image segmentation were conducted to complete the extraction of green space along roads. The segmentation results were evaluated by Fmeasure with P = 0.7605, R = 0.7639, F = 0.7622.

A multiple criteria analysis for household solid waste management in the urban community of Dakar.

PubMed

Kapepula, Ka-Mbayu; Colson, Gerard; Sabri, Karim; Thonart, Philippe

2007-01-01

Household solid waste management is a severe problem in big cities of developing countries. Mismanaged solid waste dumpsites produce bad sanitary, ecological and economic consequences for the whole population, especially for the poorest urban inhabitants. Dealing with this problem, this paper utilizes field data collected in the urban community of Dakar, in view of ranking nine areas of the city with respect to multiple criteria of nuisance. Nine criteria are built and organized in three families that represent three classical viewpoints: the production of wastes, their collection and their treatment. Thanks to the method PROMETHEE and the software ARGOS, we do a pair-wise comparison of the nine areas, which allows their multiple criteria rankings according to each viewpoint and then globally. Finding the worst and best areas in terms of nuisance for a better waste management in the city is our final purpose, fitting as well as possible the needs of the urban community. Based on field knowledge and on the literature, we suggest applying general and area-specific remedies to the household solid waste problems.

A roadmap to effective urban climate change adaptation

NASA Astrophysics Data System (ADS)

Setiadi, R.

2018-03-01

This paper outlines a roadmap to effective urban climate change adaptation built from our practical understanding of the evidence and effects of climate change and the preparation of climate change adaptation strategies and plans. This roadmap aims to drive research in achieving fruitful knowledge and solution-based achievable recommendations in adapting to climate change in urban areas with effective and systematic manner. This paper underscores the importance of the interplay between local government initiatives and a national government for effective adaptation to climate change and takes into account the policy process and politics. This paper argues that effective urban climate change adaptation has a contribution to build urban resilience and helps the achievement of national government goals and targets in climate change adaptation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haapio, Appu, E-mail: appu.haapio@vtt.fi

Requirements for the assessment tools of buildings have increased, assessing of building components or separate buildings is not enough. Neighbourhoods, built environment, public transportations, and services, should be considered simultaneously. Number of population living in urban areas is high and increasing rapidly. Urbanisation is a major concern due to its detrimental effects on the environment. The aim of this study is to clarify the field of assessment tools for urban communities by analysing the current situation. The focus is on internationally well known assessment tools; BREEAM Communities, CASBEE for Urban Development and LEED for Neigborhood Development. The interest towards certificationmore » systems is increasing amongst the authorities, and especially amongst the global investors and property developers. Achieved certifications are expected to bring measureable publicity for the developers. The assessment of urban areas enables the comparison of municipalities and urban areas, and notably supports decision making processes. Authorities, city planners, and designers would benefit most from the use of the tools during the decision making process. - Highlights: Black-Right-Pointing-Pointer The urban assessment tools have strong linkage to the region. Black-Right-Pointing-Pointer The tools promote complementary building and retrofitting existing sites. Black-Right-Pointing-Pointer Sharing knowledge and experiences is important in the development of the tools.« less

Estimation of daily maximum and minimum air temperatures in urban landscapes using MODIS time series satellite data

NASA Astrophysics Data System (ADS)

Yoo, Cheolhee; Im, Jungho; Park, Seonyoung; Quackenbush, Lindi J.

2018-03-01

Urban air temperature is considered a significant variable for a variety of urban issues, and analyzing the spatial patterns of air temperature is important for urban planning and management. However, insufficient weather stations limit accurate spatial representation of temperature within a heterogeneous city. This study used a random forest machine learning approach to estimate daily maximum and minimum air temperatures (Tmax and Tmin) for two megacities with different climate characteristics: Los Angeles, USA, and Seoul, South Korea. This study used eight time-series land surface temperature (LST) data from Moderate Resolution Imaging Spectroradiometer (MODIS), with seven auxiliary variables: elevation, solar radiation, normalized difference vegetation index, latitude, longitude, aspect, and the percentage of impervious area. We found different relationships between the eight time-series LSTs with Tmax/Tmin for the two cities, and designed eight schemes with different input LST variables. The schemes were evaluated using the coefficient of determination (R2) and Root Mean Square Error (RMSE) from 10-fold cross-validation. The best schemes produced R2 of 0.850 and 0.777 and RMSE of 1.7 °C and 1.2 °C for Tmax and Tmin in Los Angeles, and R2 of 0.728 and 0.767 and RMSE of 1.1 °C and 1.2 °C for Tmax and Tmin in Seoul, respectively. LSTs obtained the day before were crucial for estimating daily urban air temperature. Estimated air temperature patterns showed that Tmax was highly dependent on the geographic factors (e.g., sea breeze, mountains) of the two cities, while Tmin showed marginally distinct temperature differences between built-up and vegetated areas in the two cities.

Effect of land cover and green space on land surface temperature of a fast growing economic region in Malaysia

NASA Astrophysics Data System (ADS)

Sheikhi, A.; Kanniah, K. D.; Ho, C. H.

2015-10-01

Green space must be increased in the development of new cities as green space can moderate temperature in the cities. In this study we estimated the land surface temperature (LST) and established relationships between LST and land cover and various vegetation and urban surface indices in the Iskandar Malaysia (IM) region. IM is one of the emerging economic gateways of Malaysia, and is envisaged to transform into a metropolis by 2025. This change may cause increased temperature in IM and therefore we conducted a study by using Landsat 5 image covering the study region (2,217 km2) to estimate LST, classify different land covers and calculate spectral indices. Results show that urban surface had highest LST (24.49 °C) and the lowest temperature was recorded in, forest, rubber and water bodies ( 20.69 to 21.02°C). Oil palm plantations showed intermediate mean LST values with 21.65 °C. We further investigated the relationship between vegetation and build up densities with temperature. We extracted 1000 collocated pure pixels of Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Normalized Difference Built-up Index (NDBI), Urban Index (UI) and LST in the study area. Results show a strong and significant negative correlation with (R2= -0.74 and -0.79) respectively between NDVI, NDWI and LST . Meanwhile a strong positive correlation (R2=0.8 and 0.86) exists between NDBI, UI and LST. These results show the importance of increasing green cover in urban environment to combat any adverse effects of climate change.

Environmental Quality Assessment of Built Areas with High Vacancy

NASA Astrophysics Data System (ADS)

Jiang, Y.; Yuan, Y.; Neale, A. C.

2015-12-01

Around the world, many urban areas are challenged by vacant and abandoned residential and business property. High vacancy areas have often been associated with increasing public safety problems and declining property values and subsequent tax base. High vacancy can lead to visible signs of city decline and significant barriers to the revitalization of cities. Addressing the problem of vacancy requires knowledge of vacancy patterns and their possible contributing factors. In this study, we evaluated the ten year (2005-2015) urban environmental changes for some high vacancy areas. Social and economic variables derived from U.S. census data such as non-white population, employment rate, housing price, and environmental variables derived from National Land Cover Data such as land cover and impervious area, were used as the basis for analysis. Correlation analysis and principle components analysis were performed at the Census Block Group level. Three components were identified and interpreted as economic status, urbanness, and greenness. A synthetic Urban Environmental Quality (UEQ) index was developed by integrating the three principle components according to their weights. Comparisons of the UEQ indices between the 2005 and 2015 in the increasingly high vacancy area provided useful information for investigating the possible associations between social, economic, and environmental factors, and the vacancy status. This study could provide useful information for understanding the complex issues leading to vacancy and facilitating future rehabilitation of vacant urban area.

Population-Adjusted Street Connectivity, Urbanicity and Risk of Obesity in the U.S

PubMed Central

Wang, Fahui; Wen, Ming; Xu, Yanqing

2013-01-01

Street connectivity, defined as the number of (3-way or more) intersections per area unit, is an important index of built environments as a proxy for walkability in a neighborhood. This paper examines its geographic variations across the rural-urban continuum (urbanicity), major racial-ethnic groups and various poverty levels. The population-adjusted street connectivity index is proposed as a better measure than the regular index for a large area such as county due to likely concentration of population in limited space within the large area. Based on the data from the Behavioral Risk Factor Surveillance System (BRFSS), this paper uses multilevel modeling to analyze its association with physical activity and obesity while controlling for various individual and county-level variables. Analysis of data subsets indicates that the influences of individual and county-level variables on obesity risk vary across areas of different urbanization levels. The positive influence of street connectivity on obesity control is limited to the more but not the mostly urbanized areas. This demonstrates the value of obesogenic environment research in different geographic settings, helps us reconcile and synthesize some seemingly contradictory results reported in different studies, and also promotes that effective policies need to be highly sensitive to the diversity of demographic groups and geographically adaptable. PMID:23667278

Effects of living near a new urban motorway on the travel behaviour of local residents in deprived areas: Evidence from a natural experimental study.

PubMed

Foley, Louise; Prins, Richard; Crawford, Fiona; Sahlqvist, Shannon; Ogilvie, David

2017-01-01

We evaluated the effects of a new motorway built through deprived neighbourhoods on travel behaviour in residents. This natural experiment comprised a longitudinal cohort (n=365) and two cross-sectional samples (baseline n=980; follow-up n=978) recruited in 2005 and 2013. Adults from one of three study areas - surrounding the new motorway (South), an existing motorway (East), or no motorway (North) - completed a previous day travel record. Adjusted two-part regression models examined associations between exposure and outcome. Compared to the North, cohort participants in the South were more likely to undertake travel by any mode (OR 2.1, 95% CI 1.0-4.2) at follow-up. Within the South study area, cohort participants living closer to a motorway junction were more likely to travel by any mode at follow-up (OR 4.7, 95% CI 1.1-19.7), and cross-sectional participants living closer were more likely to use a car at follow-up (OR 3.4, 95% CI 1.1-10.7), compared to those living further away. Overall, the new motorway appeared to promote travel and car use in those living nearby, but did not influence active travel. This may propagate socioeconomic inequalities in non-car owners. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

An integrated material metabolism model for stocks of urban road system in Beijing, China.

PubMed

Guo, Zhen; Hu, Dan; Zhang, Fuhua; Huang, Guolong; Xiao, Qiang

2014-02-01

Rapid urbanization has greatly altered the urban metabolism of material and energy. As a significant part of the infrastructure, urban roads are being rapidly developed worldwide. Quantitative analysis of metabolic processes on urban road systems, especially the scale, composition and spatial distribution of their stocks, could help to assess the resource appropriation and potential environmental impacts, as well as improve urban metabolism models. In this paper, an integrated model, which covered all types of roads, intersection structures and ancillary facilities, was built for calculating the material stocks of urban road systems. Based on a bottom-up method, the total stocks were disassembled into a number of stock parts rather than obtained by input-output data, which provided an approach promoting data availability and inner structure understanding. The combination with GIS enabled the model to tackle the complex structures of road networks and avoid double counting. In the case study of Beijing, the following results are shown: 1) The total stocks for the entire road system reached 159 million tons, of which nearly 80% was stored in roads, and 20% in ancillary facilities. 2) Macadam was the largest stock (111 million tons), while stone mastic asphalt, polyurethane plastics, and atactic polypropylene accounted for smaller components of the overall system. 3) The stock per unit area of pedestrian overcrossing was higher than that of the other stock units in the entire system, and its steel stocks reached 0.49 t/m(2), which was 10 times as high as that in interchanges. 4) The high stock areas were mainly distributed in ring-shaped and radial expressways, as well as in major interchanges. 5) Expressways and arterials were excessively emphasized, while minor roads were relatively ignored. However, the variation of cross-sectional thickness in branches and neighborhood roads will have a significant impact on the scale of material stocks in the entire road system. © 2013.

A novel built-up spectral index developed by using multiobjective particle-swarm-optimization technique

NASA Astrophysics Data System (ADS)

Sameen, Maher Ibrahim; Pradhan, Biswajeet

2016-06-01

In this study, we propose a novel built-up spectral index which was developed by using particle-swarm-optimization (PSO) technique for Worldview-2 images. PSO was used to select the relevant bands from the eight (8) spectral bands of Worldview-2 image and then were used for index development. Multiobiective optimization was used to minimize the number of selected spectral bands and to maximize the classification accuracy. The results showed that the most important and relevant spectral bands among the eight (8) bands for built-up area extraction are band4 (yellow) and band7 (NIR1). Using those relevant spectral bands, the final spectral index was form ulated by developing a normalized band ratio. The validation of the classification result using the proposed spectral index showed that our novel spectral index performs well compared to the existing WV -BI index. The accuracy assessment showed that the new proposed spectral index could extract built-up areas from Worldview-2 image with an area under curve (AUC) of (0.76) indicating the effectiveness of the developed spectral index. Further improvement could be done by using several datasets during the index development process to ensure the transferability of the index to other datasets and study areas.

Landcover change and light pollution in Kota Bandarlampung

NASA Astrophysics Data System (ADS)

Rohman, Akmal F.; Hafidz, Muhammad; Hazairin, Azra Q.; Riadini, Fitri

2016-10-01

Excessive emission of light or light pollution at night is one of the elements of environmental pollution. Indirectly light pollution causes increase of fossil fuel use, greenhouse gasses and pollution in the atmosphere. Direct effects of light pollution including: disturbance of animals life, human's psychology and environmental degradation. Light pollution in an area is related with the existence of built-up area and the lack of vegetation as a manifestation of economic and population growth. This research aims to know the relation of land cover changes with light pollution in Bandar Lampung and surrounding with 40 km radius over the last ten years. This research used satellite imagery to obtained data and later does the verification and accuracy tests on the field. The variables used in this research include light pollution radiance value, percentages in the built-up area and vegetation density. Light pollution radiance value is obtained from DMSP-OLS Version 4 satellite images, while the changes of built up and vegetation density data obtained from NDBI dan NDVI from Landsat 8 satellite images. The research area is divided into a grid with a size of 30"×30" which is the same as spatial resolution of DMSP. From sample grids, regression analysis between the percentage of light pollution radiance value with the percentage of NDVI and NDBI index on each grids. The percentages of built up areas and vegetation has 58 % of fair correlation with light emission.

The Built Environment and Its Relationship to the Public’s Health: The Legal Framework

PubMed Central

Perdue, Wendy Collins; Stone, Lesley A.; Gostin, Lawrence O.

2003-01-01

The built environment significantly affects the public’s health. This was most obvious when infectious disease was the primary public health threat during the industrial revolution; unsanitary conditions and overcrowded urban areas facilitated the spread of infection. However, even today in the age of chronic diseases there remains an important connection between population health and the built environment. Physical spaces can expose people to toxins or pollutants and influence lifestyles that contribute to diabetes, coronary vascular disease, and asthma. Public health advocates can help shape the design of cities and suburbs in ways that improve public health, but to do so effectively they need to understand the legal framework. This article reviews the connection between public health and the built environment and then describes the legal pathways for improving the design of our built environment. PMID:12948949

Urban heat island effect: A systematic review of spatio-temporal factors, data, methods, and mitigation measures

NASA Astrophysics Data System (ADS)

Deilami, Kaveh; Kamruzzaman, Md.; Liu, Yan

2018-05-01

Despite research on urban heat island (UHI) effect has increased exponentially over the last few decades, a systematic review of factors contributing to UHI effect has scarcely been reported in the literature. This paper provides a systematic and overarching review of different spatial and temporal factors affecting the UHI effect. UHI is a phenomenon when urban areas experience a higher temperature than their surrounding non-urban areas and is considered as a critical factor contributing to global warming, heat related mortalities, and unpredictable climatic changes. Therefore, there is a pressing need to identify the spatio-temporal factors that contribute to (or mitigate) the UHI effect in order to develop a thorough understanding of their causal mechanism so that these are addressed through urban planning policies. This paper systematically identified 75 eligible studies on UHI effect and reviews the nature and type of satellite images used, the techniques applied to classify land cover/use changes, the models to assess the link between spatio-temporal factors and UHI effect, and the effects of these factors on UHI. The review results show that: a) 54% of the studies used Landsat TM images for modelling the UHI effect followed by Landsat ETM (34%), and MODIS (28%); b) land cover indices (46%), followed by supervised classification (17%) were the dominant methods to derive land cover/use changes associated with UHI effect; c) ordinary least square regression is the most commonly applied method (68%) to investigate the link between different spatio-temporal factors and the UHI effect followed by comparative analysis (33%); and d) the most common factors affecting the UHI effect as reported in the reviewed studies, include vegetation cover (44%), season (33%), built-up area (28%), day/night (25%), population density (14%), water body (12%) together with others. This research discusses the findings in policy terms and provides directions for future research.

Dynamics of land - use change in urban area in West Jakarta

NASA Astrophysics Data System (ADS)

Pangaribowo, R. L.

2018-01-01

This aim to research is to know how land use change in West Jakarta period 2000 - 2010. The research method used is descriptive method with a quantitative approach. Data analysis was done by using the result of research instrument to find out the driving of land change and to know the change of was analyzed using GIS (Geographic Information System) in Arc View GIS 3.3 program and Quantitative Analysis Model Location Quotient (LQ) and Shift-Share Analysis (SSA) In this study. The research instrument used in the analysis was observation and documentation. Based on the analysis conducted, the results of research on land use change in West Jakarta in the period of 10 years from 2000 until 2010 is caused by several aspects that are related to each other, namely political, economic, demographic, and cultural aspects. The land use change occurred in the area which decreased by minus 367,79 hectares (2.87%), the open space area decreased by minus 103.36 hectares (0.8%), the built up area increased by 201.13 hectares (1.57%), and the settlement area was 27.14 hectares (0.21%).

Making unhealthy places: The built environment and non-communicable diseases in Khayelitsha, Cape Town.

PubMed

Smit, Warren; de Lannoy, Ariane; Dover, Robert V H; Lambert, Estelle V; Levitt, Naomi; Watson, Vanessa

2016-05-01

In this paper, we examine how economic, social and political forces impact on NCDs in Khayelitsha (a predominantly low income area in Cape Town, South Africa) through their shaping of the built environment. The paper draws on literature reviews and ethnographic fieldwork undertaken in Khayelitsha. The three main pathways through which the built environment of the area impacts on NCDs are through a complex food environment in which it is difficult to achieve food security, an environment that is not conducive to safe physical activity, and high levels of depression and stress (linked to, amongst other factors, poverty, crime and fear of crime). All of these factors are at least partially linked to the isolated, segregated and monofunctional nature of Khayelitsha. The paper highlights that in order to effectively address urban health challenges, we need to understand how economic, social and political forces impact on NCDs through the way they shape built environments. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The scaling structure of the global road network

PubMed Central

Giometto, Andrea; Shai, Saray; Bertuzzo, Enrico; Mucha, Peter J.; Rinaldo, Andrea

2017-01-01

Because of increasing global urbanization and its immediate consequences, including changes in patterns of food demand, circulation and land use, the next century will witness a major increase in the extent of paved roads built worldwide. To model the effects of this increase, it is crucial to understand whether possible self-organized patterns are inherent in the global road network structure. Here, we use the largest updated database comprising all major roads on the Earth, together with global urban and cropland inventories, to suggest that road length distributions within croplands are indistinguishable from urban ones, once rescaled to account for the difference in mean road length. Such similarity extends to road length distributions within urban or agricultural domains of a given area. We find two distinct regimes for the scaling of the mean road length with the associated area, holding in general at small and at large values of the latter. In suitably large urban and cropland domains, we find that mean and total road lengths increase linearly with their domain area, differently from earlier suggestions. Scaling regimes suggest that simple and universal mechanisms regulate urban and cropland road expansion at the global scale. As such, our findings bear implications for global road infrastructure growth based on land-use change and for planning policies sustaining urban expansions. PMID:29134071

The scaling structure of the global road network.

PubMed

Strano, Emanuele; Giometto, Andrea; Shai, Saray; Bertuzzo, Enrico; Mucha, Peter J; Rinaldo, Andrea

2017-10-01

Because of increasing global urbanization and its immediate consequences, including changes in patterns of food demand, circulation and land use, the next century will witness a major increase in the extent of paved roads built worldwide. To model the effects of this increase, it is crucial to understand whether possible self-organized patterns are inherent in the global road network structure. Here, we use the largest updated database comprising all major roads on the Earth, together with global urban and cropland inventories, to suggest that road length distributions within croplands are indistinguishable from urban ones, once rescaled to account for the difference in mean road length. Such similarity extends to road length distributions within urban or agricultural domains of a given area. We find two distinct regimes for the scaling of the mean road length with the associated area, holding in general at small and at large values of the latter. In suitably large urban and cropland domains, we find that mean and total road lengths increase linearly with their domain area, differently from earlier suggestions. Scaling regimes suggest that simple and universal mechanisms regulate urban and cropland road expansion at the global scale. As such, our findings bear implications for global road infrastructure growth based on land-use change and for planning policies sustaining urban expansions.

Public Health Adaptation to Climate Change in Large Cities: A Global Baseline.

PubMed

Araos, Malcolm; Austin, Stephanie E; Berrang-Ford, Lea; Ford, James D

2016-01-01

Climate change will have significant impacts on human health, and urban populations are expected to be highly sensitive. The health risks from climate change in cities are compounded by rapid urbanization, high population density, and climate-sensitive built environments. Local governments are positioned to protect populations from climate health risks, but it is unclear whether municipalities are producing climate-adaptive policies. In this article, we develop and apply systematic methods to assess the state of public health adaptation in 401 urban areas globally with more than 1 million people, creating the first global baseline for urban public health adaptation. We find that only 10% of the sampled urban areas report any public health adaptation initiatives. The initiatives identified most frequently address risks posed by extreme weather events and involve direct changes in management or behavior rather than capacity building, research, or long-term investments in infrastructure. Based on our characterization of the current urban health adaptation landscape, we identify several gaps: limited evidence of reporting of institutional adaptation at the municipal level in urban areas in the Global South; lack of information-based adaptation initiatives; limited focus on initiatives addressing infectious disease risks; and absence of monitoring, reporting, and evaluation. © The Author(s) 2015.

Building partnerships for healthy environments: research, leadership and education.

PubMed

Thompson, Susan; Kent, Jennifer; Lyons, Claudine

2014-12-01

As populations across the globe face an increasing health burden from rising rates of obesity, diabetes and other lifestyle-related diseases, health professionals are collaborating with urban planners to influence city design that supports healthy ways of living. This paper details the establishment and operation of an innovative, interdisciplinary collaboration that brings together urban planning and health. Situated in a built environment faculty at one of Australia's most prestigious universities, the Healthy Built Environments Program (HBEP) partners planning academics, a health non-government organisation, local councils and private planning consultants in a state government health department funded consortium. The HBEP focuses on three strategic areas: research, workforce development and education, and leadership and advocacy. Interdisciplinary research includes a comprehensive literature review that establishes Australian-based evidence to support the development, prioritisation and implementation of healthy built environment policies and practices. Another ongoing study examines the design features, social interventions and locational qualities that positively benefit human health. Formal courses, workshops, public lectures and e-learning develop professional capacity, as well as skills in interdisciplinary practice to support productive collaborations between health professionals and planners. The third area involves working with government and non-government agencies, and the private sector and the community, to advocate closer links between health and the built environment. Our paper presents an overview of the HBEP's major achievements. We conclude with a critical review of the challenges, revealing lessons in bringing health and planning closer together to create health-supportive cities for the 21st century.

Approach to the land-use change and its influential factors in Loess Plateau of Dingxi Prefecture

NASA Astrophysics Data System (ADS)

Yu, Li; Dong, Suocheng; Hou, Xiaoli; Fan, Zhenjun

2004-11-01

Based on land-use datum (at scale of 100,000) of the interpretation of Landsat Thematic Mapper in 1980, 1995 and 2000, which came from environmental database of the Chinese Academy of Sciences, the authors investigated land-use change and influential factors by the combined use of geographic information systems (GIS) method, Markov model and canonical correlation analysis (CCA) statistical method. The results showed that, in the periods 1980-2000, crop land increased by 0.58 percent (4278.86 hectares), of which 92.93 percent was transformed from grassland and 7.07 percent from forestland. Urban or built-up land increased by 26.23 percent (687.45 hectares), of which 77.35 percent was transformed from cropland. Rural residential land increased by 5.17 percent (1324.37 hectares). Forestland and water land decreased in area. Grassland decreased by 0.57 percent (5706.77 hectares). Secondly, transition rate of landscape spatial pattern among the landscape elements from 1995 to 2000 was slower than that from 1980 to 1995. Land use types as cropland, grassland, woodland and rural residential land were the primary change types from 1995 to 2000. Thirdly, both natural and social economic factors influenced land use pattern. The population and per capita grain yield were positively correlated to rural residential pattern. The spatial distribution of grassland and cropland showed strong positive correlation to annual rainfall and annual air temperature, and negative association to annual per capita net income of rural residents. The poor annual per capita net income of rural residents and investment in capital construction restricted the extended area of urban build-up land. Therefore, the drought is not proportional to pattern of urban build-up land. The study verified the analysis conclusion of influential factors by redundancy degree of CCA. The integration of remote sensing data, GIS, Markov process and CCA provided a comprehensive method to analyze land use pattern and process with influential factors.

Comparison of different statistical modelling approaches for deriving spatial air temperature patterns in an urban environment

NASA Astrophysics Data System (ADS)

Straub, Annette; Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Geruschkat, Uta; Jacobeit, Jucundus; Kühlbach, Benjamin; Kusch, Thomas; Richter, Katja; Schneider, Alexandra; Umminger, Robin; Wolf, Kathrin

2017-04-01

Frequently spatial variations of air temperature of considerable magnitude occur within urban areas. They correspond to varying land use/land cover characteristics and vary with season, time of day and synoptic conditions. These temperature differences have an impact on human health and comfort directly by inducing thermal stress as well as indirectly by means of affecting air quality. Therefore, knowledge of the spatial patterns of air temperature in cities and the factors causing them is of great importance, e.g. for urban planners. A multitude of studies have shown statistical modelling to be a suitable tool for generating spatial air temperature patterns. This contribution presents a comparison of different statistical modelling approaches for deriving spatial air temperature patterns in the urban environment of Augsburg, Southern Germany. In Augsburg there exists a measurement network for air temperature and humidity currently comprising 48 stations in the city and its rural surroundings (corporately operated by the Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health and the Institute of Geography, University of Augsburg). Using different datasets for land surface characteristics (Open Street Map, Urban Atlas) area percentages of different types of land cover were calculated for quadratic buffer zones of different size (25, 50, 100, 250, 500 m) around the stations as well for source regions of advective air flow and used as predictors together with additional variables such as sky view factor, ground level and distance from the city centre. Multiple Linear Regression and Random Forest models for different situations taking into account season, time of day and weather condition were applied utilizing selected subsets of these predictors in order to model spatial distributions of mean hourly and daily air temperature deviations from a rural reference station. Furthermore, the different model setups were evaluated and the relative importance of individual predictors was examined via averaging over orderings (for MLR) and permutation importance (for RF) respectively. The results indicate that MLR is superior to RF with mean squared skill scores reaching up to 0.85 and R2 in leave-one-out cross validation up to 65% for individual situations and setups. The best performing models are obtained for situations with low to medium wind velocities before sunrise and after sunset. Important predictor variables for these situations are percentage of built-up area, sky view factor, and distance from the city centre.

Urban green and grey space in relation to respiratory health in children.

PubMed

Tischer, Christina; Gascon, Mireia; Fernández-Somoano, Ana; Tardón, Adonina; Lertxundi Materola, Aitana; Ibarluzea, Jesus; Ferrero, Amparo; Estarlich, Marisa; Cirach, Marta; Vrijheid, Martine; Fuertes, Elaine; Dalmau-Bueno, Albert; Nieuwenhuijsen, Mark J; Antó, Josep M; Sunyer, Jordi; Dadvand, Payam

2017-06-01

We assessed the effect of three different indices of urban built environment on allergic and respiratory conditions.This study involved 2472 children participating in the ongoing INMA birth cohort located in two bio-geographic regions (Euro-Siberian and Mediterranean) in Spain. Residential surrounding built environment was characterised as 1) residential surrounding greenness based on satellite-derived normalised difference vegetation index (NDVI), 2) residential proximity to green spaces and 3) residential surrounding greyness based on urban land use patterns. Information on wheezing, bronchitis, asthma and allergic rhinitis up to age 4 years was obtained from parent-completed questionnaires. Logistic regression and generalised estimating equation modelling were performed.Among children from the Euro-Siberian region, higher residential surrounding greenness and higher proximity to green spaces were negatively associated with wheezing. In the Mediterranean region, higher residential proximity to green spaces was associated with a reduced risk for bronchitis. A higher amount of residential surrounding greyness was found to increase the risk for bronchitis in this region.Associations between indices of urban residential greenness and greyness with respiratory diseases differ by region. The pathways underlying these associations require further exploration. Copyright ©ERS 2017.

Geological and Geophysical Analysis of the Processes Ground Cracking and Associated Risks in Urban Basins in the Eastern and Northern of Jalisco Block, Mexico.

NASA Astrophysics Data System (ADS)

Suarez-Plascencia, C.

2016-12-01

The Jalisco Block (JB) is located in the western sector of Mexican Volcanic Belt; it is bounded on the east by the Colima graben-Zacoalco and apparently the north by the River Grande de Santiago. Three landform are regionally identified: mountain areas, piedmont and plains formed by deposits of tuffs, volcanic ash and sediment filled. These plains have been progressively urbanized since the sixteenth century; they were built in around the Guadalajara Metropolitan Area, as well as small towns like Sayula, Ciudad Guzman, Zacoalco, Jocotepec and nearby villages, in which all together are populated by about 6 million people. Since 1912 there are records of damages by the continuous formation of ground cracking, this process has increased over the past two decades, affecting natural soil, agricultural areas, urban areas and infrastructure of roads and highways. These cracks generally have a SW-NE orientation similar with the alignment of regional geological structures. They are characterized by settlements and forming steps of a few centimeters, with lengths from 300 to 1000 m and depths of a few centimeters to 15 meters and width of up to 2.5 m. Formed mainly during the rainy season from June to October each year. Recent damages have generated losses of several hundreds of thousands of dollars, especially in Ciudad Guzman, located in southern BJ, where a crack of 2.5 km was observed in 2012 and it has long affected the downtown area, the town of Nextipac-Tesistan, municipality of Zapopan in the northern sector of JB. This territory is formed by a thick deposit of pumice tuffs, which has presented cracks in the years 1912, 1975, 1987, 2004 and 2015, affecting also agricultural and urban areas. The paper will presents results which will analyze and discern through geological, geophysical and with technology of geographic information, the origin of these cracks, which can be associated with active tectonic structures, geo-hydrological processes, extraction of underground water or a combination of these three factors. Mapping of risk areas affected by these geological processes will be presented.

Landsat View: Istanbul, Turkey

NASA Image and Video Library

2017-12-08

Istanbul has been a bustling trade city for thousands of years. In this 1975 image, taken by Landsat, the city centers on the Golden Horn the estuary that flows into the Bosporus Straight at the center of the scene. Shown in false color, vegetation is red, urban areas are gray, and water appears black. A bridge built in 1973 to connect the Asian and European sides of Istanbul is barely visible. By 2011, Istanbul's population had exploded from 2 to 13 million people, and the city has gone through a dramatic expansion. This Landsat 5 image shows densely packed urban areas stretching along the Sea of Marmara and up the Bosporus Straight where a second bridge built in 1988 now crosses the water. ---- NASA and the U.S. Department of the Interior through the U.S. Geological Survey (USGS) jointly manage Landsat, and the USGS preserves a 40-year archive of Landsat images that is freely available over the Internet. The next Landsat satellite, now known as the Landsat Data Continuity Mission (LDCM) and later to be called Landsat 8, is scheduled for launch in 2013. In honor of Landsat’s 40th anniversary in July 2012, the USGS released the LandsatLook viewer – a quick, simple way to go forward and backward in time, pulling images of anywhere in the world out of the Landsat archive. NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Mulch flammability

Treesearch

Wayne Zipperer; Alan Long; Brian Hnton; Alexander Maranghides; William Mell

2007-01-01

Regardless of how horrible and devastating wildland fires are portrayed by the media, they are a natural disturbance that many native ecosystems depend on for regeneration. As the population of the United States increases, more individuals are building their homes in wildlands rather than urban landscapes. Homes built in undeveloped wildland vegetation create areas...

An Automated Approach to Extracting River Bank Locations from Aerial Imagery Using Image Texture

DTIC Science & Technology

2015-11-04

is more likely to be encountered in high latitudes. The technique recognizes areas of urban or rural built environments, such as mowed fields...optical remote sensing of river channel morphology and in-stream habitat : physical basis and feasability. Remote Sensing of the Environment 93: 493

Estimating Urban Gross Primary Productivity at High Spatial Resolution

NASA Astrophysics Data System (ADS)

Miller, David Lauchlin

Gross primary productivity (GPP) is an important metric of ecosystem function and is the primary way carbon is transferred from the atmosphere to the land surface. Remote sensing techniques are commonly used to estimate regional and global GPP for carbon budgets. However, urban areas are typically excluded from such estimates due to a lack of parameters specific to urban vegetation and the modeling challenges that arise in mapping GPP across heterogeneous urban land cover. In this study, we estimated typical midsummer GPP within and among vegetation and land use types in the Minneapolis-Saint Paul, Minnesota metropolitan region by deriving light use efficiency parameters specific to urban vegetation types using in situ flux observations and WorldView-2 high spatial resolution satellite imagery. We produced a land cover classification using the satellite imagery, canopy height data from airborne lidar, and leaf-off color-infrared aerial orthophotos, and used regional GIS layers to mask certain land cover/land use types. The classification for built-up and vegetated urban land cover classes distinguished deciduous trees, evergreen trees, turf grass, and golf grass from impervious and soil surfaces, with an overall classification accuracy of 80% (kappa = 0.73). The full study area had 52.1% vegetation cover. The light use efficiency for each vegetation class, with the exception of golf grass, tended to be low compared to natural vegetation light use efficiencies in the literature. The mapped GPP estimates were within 11% of estimates from independent tall tower eddy covariance measurements. The order of the mapped vegetation classes for the full study area in terms of mean GPP from lowest to highest was: deciduous trees (2.52 gC m -2 d-1), evergreen trees (5.81 gC m-2 d-1), turf grass (6.05 gC m-2 d-1), and golf grass (11.77 gC m-2 d-1). Turf grass GPP had a larger coefficient of variation (0.18) than the other vegetation classes (˜0.10). Mean land use GPP for the full study area varied as a function of percent vegetation cover. Urban GPP in general, both including and excluding non-vegetated areas, tended to be low relative to natural forests and grasslands. Our results demonstrate that, at the scale of neighborhoods and city blocks within heterogeneous urban landscapes, high spatial resolution GPP estimates are valuable to develop comparisons such as within and among vegetation cover classes and land use types.

Assessing Stream Restoration Potential of Recreational Enhancements on an Urban Stream, Springfield, OH

NASA Astrophysics Data System (ADS)

Ritter, J. B.; Evelsizor, A.; Minter, K.; Rigsby, C.; Shaw, K.; Shearer, K.

2010-12-01

Restoration potential of urban streams is inherently constrained by urban infrastructure. Roads and built structures may necessitate a static stream planform while water, sewage, and electrical utilities buried in the stream channel require a stable grade. A privately-led initiative to improve the recreational potential of a 9-km reach of Buck Creek and its tributary Beaver Creek in Springfield, Ohio, includes the modification of four lowhead dams with hydraulic heights up to 3 m. Modifications to the dams include replacing their hydraulic height with a series of drop structures engineered to create hydraulics conducive to kayak play. Two of the lowhead dams have been modified to date. The purpose of this study is to assess the potential benefits of modifications designed for their recreational value for stream restoration. The drop structure is a constructed channel constriction comprised of a hard step in the long stream profile immediately upstream of a scour pool, forming a morphologic sequence of constriction, step, and pool. Up to 4 drop structures are used along a given stream reach, constructed in the area of the former dam, its scour pool and a portion of the impounded area. Though not designed for stream restoration purposes, these structures potentially act as series a riffle-pool sequences. Changes in the stream habitat, water chemistry, and macroinvertebrates in response to dam modification highlight the potential for incorporating stream restoration into the engineering design. Following modification of two of the dams, the in-stream habitat quality, as measured by physical and biological indices, increased at one site and decreased at the other site, depending on whether the uppermost drop structure at the site reduced or expanded the impounded area. In the best case, channel sands and gravels, free of fine sand, silt, and organics, have deposited in a crescentic-shaped bar paralleling and grading to the constriction and step. Greater abundance and diversity of pollution-intolerant macroinvertebrates, supported by higher dissolved oxygen in the substrate, characterizes riffles at these sites.

Population vulnerability to storm surge flooding in coastal Virginia, USA.

PubMed

Liu, Hua; Behr, Joshua G; Diaz, Rafael

2016-07-01

This study aims to assess the vulnerability of populations to storm surge flooding in 12 coastal localities of Virginia, USA. Population vulnerability is assessed by way of 3 physical factors (elevation, slope, and storm surge category), 3 built-up components (road availability, access to hospitals, and access to shelters), and 3 household conditions (storm preparedness, financial constraints to recovering from severe weather events, and health fragility). Fuzzy analysis is used to generate maps illustrating variation in several types of population vulnerability across the region. When considering physical factors and household conditions, the most vulnerable neighborhoods to sea level rise and storm surge flooding are largely found in urban areas. However, when considering access to critical infrastructure, we find rural residents to be more vulnerable than nonrural residents. These detailed assessments can inform both local and state governments in catastrophic planning. In addition, the methodology may be generalized to assess vulnerability in other coastal corridors and communities. The originality is highlighted by evaluating socioeconomic conditions at refined scale, incorporating a broader range of human perceptions and predispositions, and employing a geoinformatics approach combining physical, built-up, and socioeconomic conditions for population vulnerability assessment. Integr Environ Assess Manag 2016;12:500-509. © 2015 SETAC. © 2015 SETAC.

Assessing the effect of wind speed/direction changes on urban heat island intensity of Istanbul.

NASA Astrophysics Data System (ADS)

Perim Temizoz, Huriye; Unal, Yurdanur S.

2017-04-01

Assessing the effect of wind speed/direction changes on urban heat island intensity of Istanbul. Perim Temizöz, Deniz H. Diren, Cemre Yürük and Yurdanur S. Ünal Istanbul Technical University, Department of Meteorological Engineering, Maslak, Istanbul, Turkey City or metropolitan areas are significantly warmer than the outlying rural areas since the urban fabrics and artificial surfaces which have different radiative, thermal and aerodynamic features alter the surface energy balance, interact with the regional circulation and introduce anthropogenic sensible heat and moisture into the atmosphere. The temperature contrast between urban and rural areas is most prominent during nighttime since heat is absorbed by day and emitted by night. The intensity of the urban heat island (UHI) vary considerably depending on the prevailent meteorological conditions and the characteristics of the region. Even though urban areas cover a small fraction of Earth, their climate has greater impact on the world's population. Over half of the world population lives in the cities and it is expected to rise within the coming decades. Today almost one fifth of the Turkey's population resides in Istanbul with the percentage expected to increase due to the greater job opportunities compared to the other cities. Its population has been increased from 2 millions to 14 millions since 1960s. Eventually, the city has been expanded tremendously within the last half century, shifting the landscape from vegetation to built up areas. The observations of the last fifty years over Istanbul show that the UHI is most pronounced during summer season. The seasonal temperature differences between urban and suburban sites reach up to 3 K and roughly haft degree increase in UHI intensity is observed after 2000. In this study, we explore the possible range of heat load and distribution over Istanbul for different prevailing wind conditions by using the non-hydrostatic MUKLIMO3 model developed by DWD (Deutscher Wetterdienst). The study is focused on the spatial gradients of temperature, humidity and winds during summer. The model run by the average temperature and humidity vertical profiles over Istanbul during summer season with 200 m resolution. A series of sensitivity tests are carried out for different wind speeds (1-5 m/sec) and prevailing wind directions. Land use data are created by combining the geographical data obtained from Istanbul Metropolitan Municipality and CORINE Land Cover Raster Data. The land use table involves 25 land use types. The residential areas are classified considering the percentage of the building coverages and the average height of the buildings within the grid cell. The associated parameters in land use table of MUCLIM3 are modified accordingly. Simulations show that the urban model MUCLIM3 is able to capture typical observed characteristics of urban climate of Istanbul qualitatively. The UHI effect at night is stronger at low wind speeds, depending on the two competing factors: reduced cold advection from outlying rural areas and the magnitude of the sensible heat flux over cities which offsets the reduced advective cooling. The preliminary results of the sensitivity tests are discussed by concentrating on the changes of the hot spots in Istanbul, the diurnal cycle range over different land use types at different reference levels of 5m, 30m and 50m, and the vertical profile of the meteorological variables in relation to the sea-breeze circulation. This work is funded by the ERAfrica Project LOCLIM3 and TUBITAK with the Grant Number 114Y047.

Land use/land cover change geo-informative Tupu of Nujiang River in Northwest Yunnan Province

NASA Astrophysics Data System (ADS)

Wang, Jin-liang; Yang, Yue-yuan; Huang, You-ju; Fu, Lei; Rao, Qing

2008-10-01

Land Use/Land Cover Change (LUCC) is the core components of global change researches. It is significant for understanding regional ecological environment and LUCC mechanism of large scale to develop the study of LUCC of regional level. Nujiang River is the upper reaches of a big river in the South Asia--Salween River. Nujiang River is a typical mountainous river which is 3200 kilometer long and its basin area is 32.5 × 105 square kilometer. It locates in the core of "Three Parallel Rivers" World Natural Heritage. It is one of international biodiversity conservation center of the world, the ecological fragile zone and key ecological construction area, as well as a remote undeveloped area with high diversity ethnic. With the rapidly development of society and economy, the land use and land cover changed in a great degree. The function of ecosystem has being degraded in some areas which will not only impact on the ecological construction of local area, but also on the ecological safety of lower reaches -- Salween River. Therefore it is necessary to carry out the research of LUCC of Nujiang River. Based on the theory and methods of geo-information Tupu, the "Spatial Pattern" and "Change Process" of land use of middle reach in Nujiang River from 1974 to 2004 had been studied in quantification and integration, so as to provide a case study in local area and mesoscale in time. Supported by the remote sensing and GIS technology, LUCC Tupu of 1974-2004 had been built and the characteristics of LUCC have been analyzed quantificationally. The results showed that the built-up land (Included in this category are cities, towns, villages, strip developments along highways, transportation, power, and communications facilities, and areas such as those occupied by mills, shopping centers, industrial and commercial complexes, and institutions that may, in some instances, be isolated from urban areas), agriculture land, shrubbery land, meadow & grassland, difficultly/unused land increased from 1974 to 2004, the increased area of shrubbery land was the greatest, while the area of forest, artificial forest, waters, glacier and snow covered land decreased. The biggest decreased area was forest land. The biggest LUCC was the transformation from forest land to shrubbery land, the transformation from forest land to rangeland and agriculture land was the second. The main area of LUCC located at Nujiang River valley, between 2200-3700m of the east slope in the Gaoligong Mountain and 2800-3900m of the west slope of the Biluo Snow Mountain. From the valley to peak of mountain, the main land use type was transited from built-up land, agricultures land, artificial forest land to natural forest, shrubbery and grass land. The natural forest was the main land in the past 30 years. The main driving forces were the increase of population of local area, the governmental policies (Conversion of Farmland to Forests and Grass Land Projects, etc.) and urbanization. In order to accelerate the sustainable development of society economy and the ecological environment protection in this ecological fragile zone, strict management should be adopted to adjust the behaviors of human beings. Finally, VCM (variable clumping method) curve had been used to analyses the internal spatial distribution difference of land-use/land cover which shown that the landscape fragmentation was increased, the number of patches was added, the distance between patches was diminished during the past thirty years (1974-2004).

A global analysis of the urban heat island effect based on multisensor satellite data

NASA Astrophysics Data System (ADS)

Xiao, J.; Frolking, S. E.; Milliman, T. E.; Schneider, A.; Friedl, M. A.

2017-12-01

Human population is rapidly urbanizing. In much of the world, cities are prone to hotter weather than surrounding rural areas - so-called `urban heat islands' - and this effect can have mortal consequences during heat waves. During the daytime, when the surface energy balance is driven by incoming solar radiation, the magnitude of urban warming is strongly influenced by surface albedo and the capacity to evaporate water (i.e., there is a strong relationship between vegetated land fraction and the ratio of sensible to latent heat loss or Bowen ratio). At nighttime, urban cooling is often inhibited by the thermal inertia of the built environment and anthropogenic heat exhaust from building and transportation energy use. We evaluated a suite of global remote sensing data sets representing a range of urban characteristics against MODIS-derived land-surface temperature differences between urban and surrounding rural areas. We included two new urban datasets in this analysis - MODIS-derived change in global urban extent and global urban microwave backscatter - along with several MODIS standard products and DMSP/OLS nighttime lights time series data. The global analysis spanned a range of urban characteristics that likely influence the magnitude of daytime and/or nighttime urban heat islands - urban size, population density, building density, state of development, impervious fraction, eco-climatic setting. Specifically, we developed new satellite datasets and synthesizing these with existing satellite data into a global database of urban land surface parameters, used two MODIS land surface temperature products to generate time series of daytime and nighttime urban heat island effects for 30 large cities across the globe, and empirically analyzed these data to determine specifically which remote sensing-based characterizations of global urban areas have explanatory power with regard to both daytime and nighttime urban heat islands.

Associations of built environment and children's physical activity: a narrative review.

PubMed

Masoumi, Houshmand E

2017-12-20

Childhood obesity has been an epidemic particularly in high-income countries. There is a considerable volume of data and studies depicting the rising number of obese children and adolescents in different countries. As suggested by the literature, physical inactivity is one the main drivers of childhood obesity. This paper addresses the associations of the built environment with physical activity of children in order to find to theoretically facilitate intervention and prevention measures. Literature: There is a large body of literature describing the overall determinants of children's physical activity. The built environment is one of the influential factors that have been partially examined. Among the physical environment indicators, distance to school has been repeatedly reported to be negatively associated with active travels to school; thus, it indirectly affects physical activity of children. Apart from distance to school, some other built environment indicators have also been less researched, such as population and construction densities, distance to the city center, land use mix, and type of urban fabric (urban, suburban, etc.). The purpose of this review was to shed light on some of the less-studied areas of the existing literature related to the relationship between the built environment and physical activity of children aged between 3 and 12 years. The English-language publications, majority of which were peer-reviewed journal papers published in recent years, were collected and descriptively analyzed. Two large categories were the backbone of this narrative review: (1) non-school outdoor activities of children that take place in the residential neighborhood and (2) commuting to school and the related interventions such as safe routes to school. Seven areas were synthesized by this review of the literature. Differences in associations of the built environment and physical activity in (1) different types of urban forms and land uses such as urban, suburban, high-density, etc.; (2) different city sizes such as small towns, mid-sized cities, large cities and megacities; (3) different cultures, subcultures and ethnicities in the same city of country, e.g. the Asian minority of London or the Turkish minority of Germany; (4) between perceptions of parents and children and associations with children's physical activity, e.g. how they perceive safety and security of the neighborhood; (5) associations of the built environment with children's physical activity in less-studied contexts, e.g. many developing and under-developed countries or eastern European countries; (6) differences in built environment - physical activity associations in different regions of the world, e.g. continents; and finally (7) associations between mobility patterns of parents and their children's physical activity, for instance, the frequencies of taking public transport or walk as a commute mode. Researchers are recommended to focus their less-researched subtopics mentioned under the Results section in accordance with local conditions observed in less-researched contexts so that measures and interventions are accordingly planned.

An approach to identification and modelling of artificial grounds in urban area from multidisciplinary data (Oviedo, NW Spain)

NASA Astrophysics Data System (ADS)

Pando, Luis; Flor-Blanco, Germán; María Díaz-Díaz, Luis; Arias, Daniel

2016-04-01

This contribution describes the investigation of changes on urban relief caused by anthropogenic processes in Oviedo (population 215,000), the capital city of Asturias, formerly a Christian kingdom (719-925 AD) located in the north-western Iberian Peninsula. This city is placed on a Mesozoic-Cenozoic basin above a folded Paleozoic basement. Oviedo's subsurface is formed by carbonate and siliciclastic Cretaceous formations, and the overlying fluvial-lacustrine deposits of Paleogene age; the latter are mainly composed of marls, clays and gypsum layers. The urban core, which extends 15 km2, presents an elevation range between 160 to 330 m above mean sea level and the natural slopes reach up 15o in the built-up area. The research involved at first the collection and review of more than 950 borehole logs, presenting the man-made fills an average thickness of 1.9 m with maximum value of 25 m. Then topographic variations that occurred during the period of greatest urban development were analysed through map algebra. The data used to construct Digital Elevation Models (DEM) were provided by 1:5,000 city maps performed since 1869 to the present, all properly georeferenced. The subtraction operations generated Digital Terrain Models representing ground elevation gains and losses during different periods of time, after setting the necessary control points (elevation remains invariant) and corrections in order to avoid altitude deviations between DEMs. The thicknesses estimated for the man-made fills were compared with borehole data to validate the prediction, obtaining good correlations. The GIS-based methodology was complemented by an inspection of the historical evolution of land uses (i.e., using ancient street maps, aerial images interpretation and documentary references since the thirteenth century), and the analysis of all the surficial geological maps that have been published. Man-made grounds were then classified into categories, mainly: (i) earthworks related to urban development; (ii) ground modified by civil engineering; (iii) ground modified by quarrying activities; (iv) dumping sites. Further modified landscapes were studied using more detailed DEMs (up to 1x1 m cell size) to generate isolines maps indicating excavated and filled areas. This research provided valuable information about the distribution, geometry, volume and origin of the main accumulations of man-made fills and excavated areas. Especially noteworthy was the study of topographic changes caused by fills and excavations related to old quarries (extracting limestone, sand and clay). These quarries, abandoned for hundreds of years, are now hardly recognizable due to the growth of the city but have great historical significance. In fact they supplied building stone for some monuments of Oviedo and the Kingdom of Asturias that are included in the World Heritage List of Unesco.

How the built environment affects physical activity: views from urban planning.

PubMed

Handy, Susan L; Boarnet, Marlon G; Ewing, Reid; Killingsworth, Richard E

2002-08-01

The link between the built environment and human behavior has long been of interest to the field of urban planning, but direct assessments of the links between the built environment and physical activity as it influences personal health are still rare in the field. Yet the concepts, theories, and methods used by urban planners provide a foundation for an emerging body of research on the relationship between the built environment and physical activity. Recent research efforts in urban planning have focused on the idea that land use and design policies can be used to increase transit use as well as walking and bicycling. The development of appropriate measures for the built environment and for travel behavior is an essential element of this research. The link between the built environment and travel behavior is then made using theoretical frameworks borrowed from economics, and in particular, the concept of travel as a derived demand. The available evidence lends itself to the argument that a combination of urban design, land use patterns, and transportation systems that promotes walking and bicycling will help create active, healthier, and more livable communities. To provide more conclusive evidence, however, researchers must address the following issues: An alternative to the derived-demand framework must be developed for walking, measures of the built environment must be refined, and more-complete data on walking must be developed. In addition, detailed data on the built environment must be spatially matched to detailed data on travel behavior.

Modeling Urban Air Quality in the Berlin-Brandenburg Region: Evaluation of a WRF-Chem Setup

NASA Astrophysics Data System (ADS)

Kuik, F.; Churkina, G.; Butler, T. M.; Lauer, A.; Mar, K. A.

2015-12-01

Air pollution is the number one environmental cause of premature deaths in Europe. Despite extensive regulations, air pollution remains a challenging issue, especially in urban areas. For studying air quality in the Berlin-Brandenburg region of Germany the Weather Research and Forecasting Model with Chemistry (WRF-Chem) is set up and evaluated against meteorological and air quality observations from monitoring stations as well as from a field campaign conducted in 2014 (incl. black carbon, VOCs as well as mobile measurements of particle size distribution and particle mass). The model setup includes 3 nested domains with horizontal resolutions of 15km, 3km, and 1km, online biogenic emissions using MEGAN 2.0, and anthropogenic emissions from the TNO-MACC-II inventory. This work serves as a basis for future studies on different aspects of air pollution in the Berlin-Brandenburg region, including how heat waves affect emissions of biogenic volatile organic compounds (BVOC) from urban vegetation (summer 2006) and the impact of selected traffic measures on air quality in the Berlin-Brandenburg area (summer 2014). The model represents the meteorology as observed in the region well for both periods. An exception is the heat wave period in 2006, where the temperature simulated with 3km and 1km resolutions is biased low by around 2°C for urban built-up stations. First results of simulations with chemistry show that, on average, WRF-Chem simulates concentrations of O3 well. However, the 8 hr maxima are underestimated, and the minima are overestimated. While NOx daily means are modeled reasonably well for urban stations, they are overestimated for suburban stations. PM10 concentrations are underestimated by the model. The biases and correlation coefficients of simulated O3, NOx, and PM10 in comparison to surface observations do not show improvements for the 1km domain in comparison to the 3km domain. To improve the model performance of the 1km domain we will include an updated emission inventory (TNO-MACC-III) as well as the interpolation of the emission data from 7km to a 1km resolution.

Modeling urban growth by the use of a multiobjective optimization approach: environmental and economic issues for the Yangtze watershed, China.

PubMed

Zhang, Wenting; Wang, Haijun; Han, Fengxiang; Gao, Juan; Nguyen, Thuminh; Chen, Yarong; Huang, Bo; Zhan, F Benjamin; Zhou, Lequn; Hong, Song

2014-11-01

Urban growth is an unavoidable process caused by economic development and population growth. Traditional urban growth models represent the future urban growth pattern by repeating the historical urban growth regulations, which can lead to a lot of environmental problems. The Yangtze watershed is the largest and the most prosperous economic area in China, and it has been suffering from rapid urban growth from the 1970s. With the built-up area increasing from 23,238 to 31,054 km(2) during the period from 1980 to 2005, the watershed has suffered from serious nonpoint source (NPS) pollution problems, which have been mainly caused by the rapid urban growth. To protect the environment and at the same time maintain the economic development, a multiobjective optimization (MOP) is proposed to tradeoff the multiple objectives during the urban growth process of the Yangtze watershed. In particular, the four objectives of minimization of NPS pollution, maximization of GDP value, minimization of the spatial incompatibility between the land uses, and minimization of the cost of land-use change are considered by the MOP approach. Conventionally, a genetic algorithm (GA) is employed to search the Pareto solution set. In our MOP approach, a two-dimensional GA, rather than the traditional one-dimensional GA, is employed to assist with the search for the spatial optimization solution, where the land-use cells in the two-dimensional space act as genes in the GA. Furthermore, to confirm the superiority of the MOP approach over the traditional prediction approaches, a widely used urban growth prediction model, cellular automata (CA), is also carried out to allow a comparison with the Pareto solution of MOP. The results indicate that the MOP approach can make a tradeoff between the multiple objectives and can achieve an optimal urban growth pattern for Yangtze watershed, while the CA prediction model just represents the historical urban growth pattern as the future growth pattern. Moreover, according to the spatial clustering index, the urban growth pattern predicted through MOP is more reasonable. In summary, the proposed model provides a set of Pareto urban growth solutions, which compromise environmental and economic issues for the Yangtze watershed.

Research on the effect of rainfall flood regulation and control of wetland park based on SWMM model—a case study of wetland park in Yuanjia village, Qishan county, Shaanxi province

NASA Astrophysics Data System (ADS)

Xu, Da; Liu, Yijie

2018-02-01

Taking the wetland park of Yuan Village in Qishan County of Shaanxi Province as the research object, this paper makes a reasonable generalization of the study area, and establishes two models of low impact development (LID) and traditional development in the park. Meantime, rainwater in the surrounding built up area is introduced to into the park for digestion. SWMM model is used to simulate the variation of the total runoff, peak flow and peak time of two development models in Wetland Park under one-hour rainfall at different recurrence periods.The runoff control effect in each single LID facility in the one-hour rainfall once during five years in the built-up area is simulated. The simulation results show that the SWMM model can not only quantify the runoff reduction effect of different LID facilities, but also provide theoretical basis and data support for the urban rainfall flood problem. LID facilities have effects on runoff reduction and peak delay. However, the combined LID facility has obvious advantages for the peak time delay and peak flow control. A single LID facility is more efficient in a single runoff volume control. The order of runoff reduction by various LID facilities is as follows: Rain garden>combined LID facility> vegetative swale> bio-retention cell > permeable pavement. The order of peak time delay effect by the LID facilities is as follows: combined LID facility> Rain garden> vegetative swale> bio-retention cell > permeable pavement. The order of peak flow reduction efficiency by various LID facilities is: combined LID facility> Rain garden> bio-retention cell > vegetative swale> permeable pavement.

keep your models up-to-date: connecting community mapping data to complex urban flood modelling

NASA Astrophysics Data System (ADS)

Winsemius, Hessel; Eilander, Dirk; Ward, Philip; Diaz Loaiza, Andres; Iliffe, Mark; Mawanda, Shaban; Luo, Tianyi; Kimacha, Nyambiri; Chen, Jorik

2017-04-01

The world is urbanizing rapidly. According to the United Nation's World Urbanization Prospect, 50% of the global population already lives in urban areas today. This number is expected to grow to 66% by 2050. The rapid changes in these urban environments go hand in hand with rapid changes in natural hazard risks, in particular in informal unplanned neighbourhoods. In Dar Es Salaam - Tanzania, flood risk dominates and given the rapid changes in the city, continuous updates of detailed street level hazard and risk mapping are needed to adequately support decision making for urban planning, infrastructure design and disaster response. Over the past years, the Ramani Huria and Zuia Mafuriko projects have mapped the most flood prone neighbourhoods, including roads, buildings, drainage and land use and contributed data to the open-source OpenStreetMap database. In this contribution, we will demonstrate how we mobilize these contributed data to establish dynamic flood models for Dar Es Salaam and keep these up-to-date by making a direct link between the data, and model schematization. The tools automatically establish a sound 1D drainage network as well as a high resolution terrain dataset, by fusing the OpenStreetMap data with existing lower resolution terrain data such as the globally available satellite based SRTM 30. It then translates these fully automatically into the inputs required for the D-HYDRO modeling suite. Our tools are built such that community and stakeholder knowledge can be included in the model details through workshops with the tools so that missing essential information about the city's details can be augmented on-the-fly. This process creates a continuous dialogue between members of the community that collect data, and stakeholders requiring data for flood models. Moreover, used taxonomy and data filtering can be configured to conditions in other cities, making the tools generic and scalable. The tools are made available open-source.

[Response of water yield function of ecosystem to land use change in Nansi Lake Basin based on CLUE-S model and InVEST model .

PubMed

Guo, Hong Wei; Sun, Xiao Yin; Lian, Li Shu; Zhang, Da Zhi; Xu, Yan

2016-09-01

Land use change has an important role in hydrological processes and utilization of water resources, and is the main driving force of water yield function of ecosystem. This paper analyzed the change of land use from 1990 to 2013 in Nansi Lake Basin, Shandong Province. The future land use in 2030 was also predicted and simulated by CLUE-S model. Based on land use scenarios, we analyzed the influence of land use change on ecosystem function of water yield in nearly 25 years through InVEST water yield model and spatial mapping. The results showed that the area of construction land increased by 3.5% in 2013 because of burgeoning urbanization process, but farmland area decreased by 2.4% which was conversed to construction land mostly. The simulated result of InVEST model suggested that water yield level of whole basin decreased firstly and increased subsequently during last 25 years and peaked at 232.1 mm in 2013. The construction land area would increase by 6.7% in 2030 based on the land use scenarios of fast urbanization, which would lead to a remarkable growth for water yield and risk of flowing flooding. However, the water yield level of whole basin would decrease by 1.2 % in 2013 if 300 meter-wide forest buffer strips around Nansi Lake were built up.

Urban Impact at the Urban-Agricultural Interface in Madison, WI: an Ecosystem Modeling Approach

NASA Astrophysics Data System (ADS)

Logan, K. E.; Kucharik, C. J.; Schneider, A.

2009-12-01

Global population and the proportion of people living in urban areas both continue to grow while average urban density is decreasing worldwide. Because urban areas are often located in the most agriculturally productive lands, expansion of the built environment can cause sharp reductions in land available for cultivation. Conversion of land to urban use also significantly alters climate variables. Urban materials differ from natural land covers in terms of albedo, thermal properties, and permeability, altering energy and water cycles. Anthropogenic heat emissions also alter the energy balance in and around a city. Preliminary analysis of urban impacts around Madison, WI, a small city located in a thriving agricultural region, was performed using the National Land Cover Database (NLCD), MODIS albedo products, ground-based observations, and a simulation of urban expansion, within a geographic information system (GIS). Population of the county is expected to increase by 58% while urban density is projected to decrease by 49% between 1992 and 2030, reflecting projected worldwide patterns. Carbon stored in the top 25cm of soil was found to be over 2.5 times greater in remnant prairies than in croplands and was calculated to be even less in urban areas; projected urban development may thus lead to large losses in carbon storage. Albedo measurements also show a significant decrease with urban development. Projected urban expansion between 2001 and 2030 is expected to convert enough agricultural lands to urban areas to result in a loss of 247,000 tons of crop yield in Dane County alone, based on current yields. For a more complete analysis of these impacts, urban parameters are incorporated into a terrestrial ecosystem model known as Agro-IBIS. This approach allows for detailed comparison of energy balance and biogeochemical cycles between local crop systems, lawns, and impervious city surfaces. Changes in these important cycles, in soil carbon storage, and in crop productivity/yield for 1992 - 2001 and projected 2030 development around Madison, WI will be shown.

Analysis of recent changes of rainfall in the foothill of the Isonzo basin and effects on the safety of urbanized areas

NASA Astrophysics Data System (ADS)

Fazzini, Massimiliano; Vaccaro, Carmela

2015-04-01

The knowledge of the distribution of rainfall in mountain environments Mediterranean is still very complex and requires a comprehensive monitoring and appropriate analytical techniques - statistics to be scientifically valid and easily communicable. The Isonzo's basin - located between Slovenia and Italy within the Julian Alps - has characteristics meteoric absolutely uncommon, revealing the wettest of entire southern side of the Alps. Nonetheless, the climatological studies of detail are very rare; resulting an insufficient knowledge of specific themes, a lack of information for the purpose of territorial planning and especially the development of forecasting future scenarios according to the IPCC guidelines. The lower valley bottom of the Soca river is particularly urbanized and cultivated and the numerous, short minor streams - such as Corno and Versotizza - run within the city of Nova Gorica and Gorizia and their industrial areas. Their torrential regime can cause a flood events in relation to the intensity of more irregular and often very abundant rainfall. In this regard, the meteorological year 2014, was the wettest and perturbed the last thirty years in the whole mountain sector of the Isonzo basin, with punctual values ranging between about 2150 mm in Gorizia and 5600 mm in Musi di Udine, compared to their respective averages of 1400 and 3000 mm in the 1981-2010 period. The high frequency of days with precipitation sufficient to cause local flooding and floods from the minor watercourses is significant increase in recent years; consequently must be considered some fundamental aspects in the planning of little space land not yet urbanized and in the exploitation of agricultural and trade resources - heart of the local economy - increasingly exposed to the floods risk. This study aims to provide a thorough knowledge of the precipitation context of the urban agglomeration of Gorizia - Nova Gorica and its significant around; so to be provided the necessary knowledge to a hydraulic design of that allows the complete safety measures in existing production sites and the correct design of urban areas not yet built up through an comprehensive and precise definition of the areas at flood risk.

Built urban heritage conservation in Islamic societies: Study case in Banda Aceh, Indonesia

NASA Astrophysics Data System (ADS)

Meutia, Z. D.

2017-06-01

This paper aims to find the concept of the built heritage related to Islamic societies with a case study in the city of Banda Aceh through study literature review, with the context of the planning in the era of uncertainty. In this paper will be elaborated and described what it was about heritage and urban heritage and conservation Islamic values in heritage, as well as explain the concept of the built heritage conservation in Islamic societies. Discussion and analysis will be done through its study literature. Literature reviews about built urban heritage conservation and perspective of the Islamic societies in Banda aceh was done using systematic methodology literature review. This methodology summarizes research results earlier that presents the fact that a more comprehensive and balanced. The synthesis of the results conducted using narrative techniques or technique of qualitative. The discovery paper in this paper is to understand the relationship the built heritage conservation of Islamic societies perspective that consider shari’a aspect and local tradition in built urban heritage that can affect to heritage planning.

Evaluation of sustainable walk-up flats in terms of urban housing renewal in coastal area

NASA Astrophysics Data System (ADS)

Septanti, D.; Kisnarini, R.; Setyawan, W.; Utami, ASPR

2018-03-01

Urban housing renewal aims to get added value while maintaining the sustainability of its environmental function and quality [4]. This research discusses the urban renewal which is done by rebuilding the affected area with walk-up flats. There are four aspects to be considered in achieving sustainability, namely: environmental, social, economic, and cultural [14]. This study is focused on cultural aspect. Sustainable walk-up flats, viewed from the micro context perspective, can later be used as one of the terms of reference in assessing the success of urban renewal projects in Indonesia. Especially in coastal areas, it becomes more challenging because coastal communities have different characteristics and the existing urban renewal flats are not necessarily appropriate for the coastal community. The methods used in this study are explorative, descriptive, ex- post, cross-sectional and synchronic evaluation. This research describes the characteristics of citizens, activities at home and the environment. Thus, the conclusions which are drawn by deductive reasoning are done using frequency, mean, etc. A mixed research method is applied combining with the analysis of quantitative and qualitative data collection and interpretation, including determining quantitative indicators and space design attributes, and qualitative user needs. This research is located in Surabaya as a sample of coastal cities with urban and environmental problems. The results of this study are the findings of indicators, directions, and concepts for Sustainable Housing Development in Coastal Areas which further can be made as scientific recommendation (to support the Housing Theory and Urban Renewal) and contribute to practical guidelines for sustainable low-cost walk-up flats in coastal areas.

Differential Responses to Woodland Character and Landscape Context by Cryptic Bats in Urban Environments

PubMed Central

Lintott, Paul R.; Bunnefeld, Nils; Minderman, Jeroen; Fuentes-Montemayor, Elisa; Mayhew, Rebekah J.; Olley, Lena; Park, Kirsty J.

2015-01-01

Urbanisation is one of the most dramatic forms of land use change which relatively few species can adapt to. Determining how and why species respond differently to urban habitats is important in predicting future biodiversity loss as urban areas rapidly expand. Understanding how morphological or behavioural traits can influence species adaptability to the built environment may enable us to improve the effectiveness of conservation efforts. Although many bat species are able to exploit human resources, bat species richness generally declines with increasing urbanisation and there is considerable variation in the responses of different bat species to urbanisation. Here, we use acoustic recordings from two cryptic, and largely sympatric European bat species to assess differential responses in their use of fragmented urban woodland and the surrounding urban matrix. There was a high probability of P. pygmaeus activity relative to P. pipistrellus in woodlands with low clutter and understory cover which were surrounded by low levels of built environment. Additionally, the probability of recording P. pygmaeus relative to P. pipistrellus was considerably higher in urban woodland interior or edge habitat in contrast to urban grey or non-wooded green space. These results show differential habitat use occurring between two morphologically similar species; whilst the underlying mechanism for this partitioning is unknown it may be driven by competition avoidance over foraging resources. Their differing response to urbanisation indicates the difficulties involved when attempting to assess how adaptable a species is to urbanisation for conservation purposes. PMID:25978034

Differential responses to woodland character and landscape context by cryptic bats in urban environments.

PubMed

Lintott, Paul R; Bunnefeld, Nils; Minderman, Jeroen; Fuentes-Montemayor, Elisa; Mayhew, Rebekah J; Olley, Lena; Park, Kirsty J

2015-01-01

Urbanisation is one of the most dramatic forms of land use change which relatively few species can adapt to. Determining how and why species respond differently to urban habitats is important in predicting future biodiversity loss as urban areas rapidly expand. Understanding how morphological or behavioural traits can influence species adaptability to the built environment may enable us to improve the effectiveness of conservation efforts. Although many bat species are able to exploit human resources, bat species richness generally declines with increasing urbanisation and there is considerable variation in the responses of different bat species to urbanisation. Here, we use acoustic recordings from two cryptic, and largely sympatric European bat species to assess differential responses in their use of fragmented urban woodland and the surrounding urban matrix. There was a high probability of P. pygmaeus activity relative to P. pipistrellus in woodlands with low clutter and understory cover which were surrounded by low levels of built environment. Additionally, the probability of recording P. pygmaeus relative to P. pipistrellus was considerably higher in urban woodland interior or edge habitat in contrast to urban grey or non-wooded green space. These results show differential habitat use occurring between two morphologically similar species; whilst the underlying mechanism for this partitioning is unknown it may be driven by competition avoidance over foraging resources. Their differing response to urbanisation indicates the difficulties involved when attempting to assess how adaptable a species is to urbanisation for conservation purposes.

Analysis of the build-up of semi and non volatile organic compounds on urban roads.

PubMed

Mahbub, Parvez; Ayoko, Godwin A; Goonetilleke, Ashantha; Egodawatta, Prasanna

2011-04-01

Vehicular traffic in urban areas may adversely affect urban water quality through the build-up of traffic generated semi and non volatile organic compounds (SVOCs and NVOCs) on road surfaces. The characterisation of the build-up processes is the key to developing mitigation measures for the removal of such pollutants from urban stormwater. An in-depth analysis of the build-up of SVOCs and NVOCs was undertaken in the Gold Coast region in Australia. Principal Component Analysis (PCA) and Multicriteria Decision tools such as PROMETHEE and GAIA were employed to understand the SVOC and NVOC build-up under combined traffic scenarios of low, moderate, and high traffic in different land uses. It was found that congestion in the commercial areas and use of lubricants and motor oils in the industrial areas were the main sources of SVOCs and NVOCs on urban roads, respectively. The contribution from residential areas to the build-up of such pollutants was hardly noticeable. It was also revealed through this investigation that the target SVOCs and NVOCs were mainly attached to particulate fractions of 75-300 μm whilst the redistribution of coarse fractions due to vehicle activity mainly occurred in the >300 μm size range. Lastly, under combined traffic scenario, moderate traffic with average daily traffic ranging from 2300 to 5900 and average congestion of 0.47 were found to dominate SVOC and NVOC build-up on roads. Copyright © 2011 Elsevier Ltd. All rights reserved.

Bright is the New Black - Multi-Year Performance of Generic High-Albedo Roofs in an Urban Climate

NASA Technical Reports Server (NTRS)

Gaffin, S. R.; Imhoff, M.; Rosenzweig, C.; Khanbilvardi, R.; Pasqualini, A.; Kong, A. Y. Y.; Grillo, D.; Freed, A.; Hillel, D.; Hartung, E.

2012-01-01

High-albedo white and cool roofing membranes are recognized as a fundamental strategy that dense urban areas can deploy on a large scale, at low cost, to mitigate the urban heat island effect. We are monitoring three generic white membranes within New York City that represent a cross-section of the dominant white membrane options for U.S. flat roofs: (1) an ethylene propylene diene monomer (EPDM) rubber membrane; (2) a thermoplastic polyolefin (TPO) membrane and; (3) an asphaltic multi-ply built-up membrane coated with white elastomeric acrylic paint. The paint product is being used by New York City s government for the first major urban albedo enhancement program in its history. We report on the temperature and related albedo performance of these three membranes at three different sites over a multi-year period. The results indicate that the professionally installed white membranes are maintaining their temperature control effectively and are meeting the Energy Star Cool Roofing performance standards requiring a three-year aged albedo above 0.50. The EPDM membrane however shows evidence of low emissivity. The painted asphaltic surface shows high emissivity but lost about half of its initial albedo within two years after installation. Given that the acrylic approach is an important "do-it-yourself," low-cost, retrofit technique, and, as such, offers the most rapid technique for increasing urban albedo, further product performance research is recommended to identify conditions that optimize its long-term albedo control. Even so, its current multi-year performance still represents a significant albedo enhancement for urban heat island mitigation.

Identifying built environmental patterns using cluster analysis and GIS: relationships with walking, cycling and body mass index in French adults.

PubMed

Charreire, Hélène; Weber, Christiane; Chaix, Basile; Salze, Paul; Casey, Romain; Banos, Arnaud; Badariotti, Dominique; Kesse-Guyot, Emmanuelle; Hercberg, Serge; Simon, Chantal; Oppert, Jean-Michel

2012-05-23

Socio-ecological models suggest that both individual and neighborhood characteristics contribute to facilitating health-enhancing behaviors such as physical activity. Few European studies have explored relationships between local built environmental characteristics, recreational walking and cycling and weight status in adults. The aim of this study was to identify built environmental patterns in a French urban context and to assess associations with recreational walking and cycling behaviors as performed by middle-aged adult residents. We used a two-step procedure based on cluster analysis to identify built environmental patterns in the region surrounding Paris, France, using measures derived from Geographic Information Systems databases on green spaces, proximity facilities (destinations) and cycle paths. Individual data were obtained from participants in the SU.VI.MAX cohort; 1,309 participants residing in the Ile-de-France in 2007 were included in this analysis. Associations between built environment patterns, leisure walking/cycling data (h/week) and measured weight status were assessed using multinomial logistic regression with adjustment for individual and neighborhood characteristics. Based on accessibility to green spaces, proximity facilities and availability of cycle paths, seven built environmental patterns were identified. The geographic distribution of built environmental patterns in the Ile-de-France showed that a pattern characterized by poor spatial accessibility to green spaces and proximity facilities and an absence of cycle paths was found only in neighborhoods in the outer suburbs, whereas patterns characterized by better spatial accessibility to green spaces, proximity facilities and cycle paths were more evenly distributed across the region. Compared to the reference pattern (poor accessibility to green areas and facilities, absence of cycle paths), subjects residing in neighborhoods characterized by high accessibility to green areas and local facilities and by a high density of cycle paths were more likely to walk/cycle, after adjustment for individual and neighborhood sociodemographic characteristics (OR = 2.5 95%CI 1.4-4.6). Body mass index did not differ across patterns. Built environmental patterns were associated with walking and cycling among French adults. These analyses may be useful in determining urban and public health policies aimed at promoting a healthy lifestyle.

Analysing the daily cycles of temperature and humidity differences between downtown and suburban environment in Budapest

NASA Astrophysics Data System (ADS)

Pongracz, Rita; Bartholy, Judit; Dezso, Zsuzsanna; Dian, Csenge; Incze, Dora; Kurcsics, Mate

2017-04-01

Urban areas evidently results in a substantial modification of natural environment including the local climatic conditions, which fundamentally influence everyday life. That is why it is important to address urban climatic issues, e.g. the urban heat island effect and its consequences. Due to the strong centralised structure of Hungary the most affected region in Hungary is the capital (Budapest) and its agglomeration area. In this research we aim to analyze the urban climatic effects in a downtown district of Budapest relative to the southeastern suburb district of the city where the synoptic station of Budapest is located. For this purpose, we started a measuring program of in-situ measurements in the spring of 2015 in the southern central located district (district IX), which can be found near the river Danube, and mainly consists of 3- and 4-storey older and newly built buildings. The newly built buildings are mainly the results of the local government's efforts to improve the environment for the citizens. Within the framework of the block rehabilitation program, inner parts of the old house blocks were demolished, and inside the blocks common green areas have been created. In our urban climate measurement program the resulting climatic conditions are evaluated with air temperature and relative humidity data recorded along a pre-defined path, which consists of 24 measuring points within the studied area. The measuring sites are located in different characteristical points of the district, such as green parks, narrow streets, paved squares and roads. In order to calculate the urban heat island intensity, temperature measurements are compared to the hourly recorded data of the synoptic station (ID number: 12843). Our relative humidity measurements are also compared to the humidity in the suburbs. Prior to the summer measuring campaign in 2016, measurements were recorded only in the daytime periods. The measuring period has been extended for 24 hours, thus, continuous 3-day-long temperature and humidity measurements were recorded during 4-6 July 2016. Moreover, new measuring instruments were used during this summer measurements with more accurate sensors and data loggers. After the summer measuring campaign the whole measurement program continued in autumn (6 days starting at 14 pm Thursdays and lasting 24 hours). Thus, summer and autumn daily cycles can be compared in the different types of the urban environment.

Measuring high-density built environment for public health research: Uncertainty with respect to data, indicator design and spatial scale.

PubMed

Sun, Guibo; Webster, Chris; Ni, Michael Y; Zhang, Xiaohu

2018-05-07

Uncertainty with respect to built environment (BE) data collection, measure conceptualization and spatial scales is evident in urban health research, but most findings are from relatively lowdensity contexts. We selected Hong Kong, an iconic high-density city, as the study area as limited research has been conducted on uncertainty in such areas. We used geocoded home addresses (n=5732) from a large population-based cohort in Hong Kong to extract BE measures for the participants' place of residence based on an internationally recognized BE framework. Variability of the measures was mapped and Spearman's rank correlation calculated to assess how well the relationships among indicators are preserved across variables and spatial scales. We found extreme variations and uncertainties for the 180 measures collected using comprehensive data and advanced geographic information systems modelling techniques. We highlight the implications of methodological selection and spatial scales of the measures. The results suggest that more robust information regarding urban health research in high-density city would emerge if greater consideration were given to BE data, design methods and spatial scales of the BE measures.

Determinants of urban resource use and resilience: a comprehensive framework

NASA Astrophysics Data System (ADS)

Romero-Lankao, P.; Bourgeron, P.; Gochis, D. J.; Rothman, D. S.; Wilhelmi, O.

2015-12-01

During the past decades urbanization has proceeded at unprecedented - yet varied - rates across urban areas globally. The social and environmental transformations implied by urban development have put many regions at risk of transforming the very characteristics that make them attractive and healthy. Meanwhile, climate change is adding new sources of risk and an array of uncertainties to the mix. These changes create risks that vary according to the characteristics of the demographic, economic, ecological, built-environment (technological) and governance dimensions of urbanization and urban areas as socioecological systems. However, few studies have explored the variation in these dimensions across urban areas. I will present a comprehensive analytical framework that explores, in urban areas, patterns of interplay, synergy and tradeoff between socio-demographic, economic, technological, ecological, and governance (SETEG) factors as they shape two issues, traditionally analyzed by separate disciplinary domains: resource use and resilience to climate hazards. Three questions guide this effort: 1) What indicators can be used to socio-demographic, economic, technological, ecological, and governance (SETEG) determinants of urban populations' resource use and resilience to climate hazards? 2) What indicators are important? 3) What combinations (i.e., tradeoffs, synergies) of causal factors better explain urban populations' resource use and resilience to hazards? The interplay between these factors as they shape a population's resource use and resilience is not exempted from synergies and tradeoffs that require careful analysis. Consider population density, a key indicator of urban form. Scholars have found that while more compact cities are more energy efficient and emit less GHG, heat stress is much worse in more compact cities. This begs the question of which combination of urban form factors need to be considered by urban planners when designing effective urban/environmental interventions. The framework, that builds on empirical work globally and in the cities of Buenos Aires, Mexico, Santiago and Mumbai, is intended to inform the design of more effective urban mitigation and adaptation policies.

Forest conservation and land development in Puerto Rico.

Treesearch

E.H. Helmer

2004-01-01

In the Caribbean island of Puerto Rico, rapid land-use changes over the past century have included recent landcover conversion to urban/built-up lands. Observations of this land development adjacent to reserves or replacing dense forest call into question how the changes relate to forests or reserved lands. Using existing maps, this study first summarizes island-wide...

Estimation of erosion-accumulative processes at the Inia River's mouth near high-rise construction zones.

NASA Astrophysics Data System (ADS)

Sineeva, Natalya

2018-03-01

Our study relevance is due to the increasing man-made impact on water bodies and associated land resources within the urban areas, as a consequence, by a change in the morphology and dynamics of Rivers' canals. This leads to the need to predict the development of erosion-accumulation processes, especially within the built-up urban areas. Purpose of the study is to develop programs on the assessment of erosion-accumulation processes at a water body, a mouth area of the Inia River, in the of perspective high-rise construction zone of a residential microdistrict, the place, where floodplain-channel complex is intensively expected to develop. Results of the study: Within the velocities of the water flow comparing, full-scale measured conditions, and calculated from the model, a slight discrepancy was recorded. This allows us to say that the numerical model reliably describes the physical processes developing in the River. The carried out calculations to assess the direction and intensity of the channel re-formations, made us possible to conclude, there was an insignificant predominance of erosion processes over the accumulative ones on the undeveloped part of the Inia River (the processes activity is noticeable only in certain areas (by the coasts and the island)). Importance of the study: The study on the erosion-accumulation processes evaluation can be used in design decisions for the future high-rise construction of this territory, which will increase their economic efficiency.

Assessing the Sustainable Development of Coastal Reclamation: A Case of Makassar Using GIS Application

NASA Astrophysics Data System (ADS)

Yurnita, A.; Trisutomo, S.; Ali, M.

2017-07-01

Reclamation has been made in many areas in Indonesia including Makassar, as a response to the present needs of land as the impact of human activity in urban area. This research aims to assess the sustainable development of coastal reclamation and focus on environmental dimension of sustainable urban development. Assessment will be done by reclamation sustainability index (RSI) and analysis by GIS as the tools. RSI was built from previous research that has simplified from many researches and analysis by Structure of Analytic Hierarchy Process (AHP) and expert choice. RSI uses 9 indices from three indicators of environment factor which are coastal resources, building and infrastructure.

Resource management as a key factor for sustainable urban planning.

PubMed

Agudelo-Vera, Claudia M; Mels, Adriaan R; Keesman, Karel J; Rijnaarts, Huub H M

2011-10-01

Due to fast urbanization and increasing living standards, the environmental sustainability of our global society becomes more and more questionable. In this historical review we investigate the role of resources management (RM) and urban planning (UP) and propose ways for integration in sustainable development (SD). RM follows the principle of circular causation, and we reflect on to what extent RM has been an element for urban planning. Since the existence of the first settlements, a close relationship between RM, urbanization and technological development has been present. RM followed the demand for urban resources like water, energy, and food. In history, RM has been fostered by innovation and technology developments and has driven population growth and urbanization. Recent massive resource demand, especially in relation to energy and material flows, has altered natural ecosystems and has resulted in environmental degradation. UP has developed separately in response to different questions. UP followed the demand for improved living conditions, often associated to safety, good manufacturing and trading conditions and appropriate sanitation and waste management. In history UP has been a developing research area, especially since the industrial era and the related strong urbanization at the end of the 18th century. UP responded to new emerging problems in urban areas and became increasingly complex. Nowadays, UP has to address many objectives that are often conflicting, including, the urban sustainability. Our current urban un-sustainability is rooted in massive resource consumption and waste production beyond natural limits, and the absence of flows from waste to resources. Therefore, sustainable urban development requires integration of RM into UP. We propose new ways to this integration. Copyright © 2011 Elsevier Ltd. All rights reserved.

Helicopter support of North Sea oil exploration.

PubMed

Preston, F S

1978-04-01

Exploration for oil beneath the North Sea started in the early 1960's with the discovery of natural gas and oil in the southern part between the coasts of East Anglia and the Netherlands. Since then oil exploration has built up considerably, the main effort moving northwards between the Shetland Islands and the Norwegian coasts. The helicopter offered the most direct and rapid contact with off-shore oil rigs and since these early days and immense helicopter operation has been built up round the borders of the North Sea by all the nations involved. Flying conditions in this area, particularly in winter, are at times difficult if not to say hazardous. Nevertheless, a sophisticated helicopter support service has been built up using modern aircraft and equipment which is unique in aviation history. This paper attempts to trace the history of the service, the operational problems involved and the special needs such as survival equipment and clothing. In addition, a co-ordinated air/sea rescue service largely based on helicopters has been built up and provides not only rescue facilities for possible rig disasters but also for shipping emergencies in the area.

The public health response to 'do-it-yourself' urbanism.

PubMed

Sibbald, Shannon L; Graham, Ross; Gilliland, Jason

2017-09-01

Greater understanding of the important and complex relationship between the built environment and human health has made 'healthy places' a focus of public health and health promotion. While current literature concentrates on creating healthy places through traditional decision-making pathways (namely, municipal land use planning and urban design processes), this paper explores do-it-yourself (DIY) urbanism: a movement circumventing traditional pathways to, arguably, create healthy places and advance social justice. Despite being aligned with several health promotion goals, DIY urbanism interventions are typically illegal and have been categorized as a type of civil disobedience. This is challenging for public health officials who may value DIY urbanism outcomes, but do not necessarily support the means by which it is achieved. Based on the literature, we present a preliminary approach to health promotion decision-making in this area. Public health officials can voice support for DIY urbanism interventions in some instances, but should proceed cautiously.

Integration of logistic regression, Markov chain and cellular automata models to simulate urban expansion

NASA Astrophysics Data System (ADS)

Jokar Arsanjani, Jamal; Helbich, Marco; Kainz, Wolfgang; Darvishi Boloorani, Ali

2013-04-01

This research analyses the suburban expansion in the metropolitan area of Tehran, Iran. A hybrid model consisting of logistic regression model, Markov chain (MC), and cellular automata (CA) was designed to improve the performance of the standard logistic regression model. Environmental and socio-economic variables dealing with urban sprawl were operationalised to create a probability surface of spatiotemporal states of built-up land use for the years 2006, 2016, and 2026. For validation, the model was evaluated by means of relative operating characteristic values for different sets of variables. The approach was calibrated for 2006 by cross comparing of actual and simulated land use maps. The achieved outcomes represent a match of 89% between simulated and actual maps of 2006, which was satisfactory to approve the calibration process. Thereafter, the calibrated hybrid approach was implemented for forthcoming years. Finally, future land use maps for 2016 and 2026 were predicted by means of this hybrid approach. The simulated maps illustrate a new wave of suburban development in the vicinity of Tehran at the western border of the metropolis during the next decades.

Toward a 30m resolution time series of historical global urban expansion: exploring variation in North American cities

NASA Astrophysics Data System (ADS)

Stuhlmacher, M.; Wang, C.; Georgescu, M.; Tellman, B.; Balling, R.; Clinton, N. E.; Collins, L.; Goldblatt, R.; Hanson, G.

2016-12-01

Global representations of modern day urban land use and land cover (LULC) extent are becoming increasingly prevalent. Yet considerable uncertainties in the representation of built environment extent (i.e. global classifications generated from 250m resolution MODIS imagery or the United States' National Land Cover Database) remain because of the lack of a systematic, globally consistent methodological approach. We aim to increase resolution, accuracy, and improve upon past efforts by establishing a data-driven definition of the urban landscape, based on Landsat 5, 7 & 8 imagery and ancillary data sets. Continuous and discrete machine learning classification algorithms have been developed in Google Earth Engine (GEE), a powerful online cloud-based geospatial storage and parallel-computing platform. Additionally, thousands of ground truth points have been selected from high resolution imagery to fill in the previous lack of accurate data to be used for training and validation. We will present preliminary classification and accuracy assessments for select cities in the United States and Mexico. Our approach has direct implications for development of projected urban growth that is grounded on realistic identification of urbanizing hot-spots, with consequences for local to regional scale climate change, energy demand, water stress, human health, urban-ecological interactions, and efforts used to prioritize adaptation and mitigation strategies to offset large-scale climate change. Future work to apply the built-up detection algorithm globally and yearly is underway in a partnership between GEE, University of California in San Diego, and Arizona State University.

Surface temperature statistics over Los Angeles - The influence of land use

NASA Technical Reports Server (NTRS)

Dousset, Benedicte

1991-01-01

Surface temperature statistics from 84 NOAA AVHRR (Advanced Very High Resolution Radiometer) satellite images of the Los Angeles basin are interpreted as functions of the corresponding urban land-cover classified from a multispectral SPOT image. Urban heat islands observed in the temperature statistics correlate well with the distribution of industrial and fully built areas. Small cool islands coincide with highly watered parks and golf courses. There is a significant negative correlation between the afternoon surface temperature and a vegetation index computed from the SPOT image.

Assessing opportunities for physical activity in the built environment of children: interrelation between kernel density and neighborhood scale.

PubMed

Buck, Christoph; Kneib, Thomas; Tkaczick, Tobias; Konstabel, Kenn; Pigeot, Iris

2015-12-22

Built environment studies provide broad evidence that urban characteristics influence physical activity (PA). However, findings are still difficult to compare, due to inconsistent measures assessing urban point characteristics and varying definitions of spatial scale. Both were found to influence the strength of the association between the built environment and PA. We simultaneously evaluated the effect of kernel approaches and network-distances to investigate the association between urban characteristics and physical activity depending on spatial scale and intensity measure. We assessed urban measures of point characteristics such as intersections, public transit stations, and public open spaces in ego-centered network-dependent neighborhoods based on geographical data of one German study region of the IDEFICS study. We calculated point intensities using the simple intensity and kernel approaches based on fixed bandwidths, cross-validated bandwidths including isotropic and anisotropic kernel functions and considering adaptive bandwidths that adjust for residential density. We distinguished six network-distances from 500 m up to 2 km to calculate each intensity measure. A log-gamma regression model was used to investigate the effect of each urban measure on moderate-to-vigorous physical activity (MVPA) of 400 2- to 9.9-year old children who participated in the IDEFICS study. Models were stratified by sex and age groups, i.e. pre-school children (2 to <6 years) and school children (6-9.9 years), and were adjusted for age, body mass index (BMI), education and safety concerns of parents, season and valid weartime of accelerometers. Association between intensity measures and MVPA strongly differed by network-distance, with stronger effects found for larger network-distances. Simple intensity revealed smaller effect estimates and smaller goodness-of-fit compared to kernel approaches. Smallest variation in effect estimates over network-distances was found for kernel intensity measures based on isotropic and anisotropic cross-validated bandwidth selection. We found a strong variation in the association between the built environment and PA of children based on the choice of intensity measure and network-distance. Kernel intensity measures provided stable results over various scales and improved the assessment compared to the simple intensity measure. Considering different spatial scales and kernel intensity methods might reduce methodological limitations in assessing opportunities for PA in the built environment.

Health and the Built Environment: Exploring Foundations for a New Interdisciplinary Profession

PubMed Central

Kent, Jennifer; Thompson, Susan

2012-01-01

The supportive role of the built environment for human health is a growing area of interdisciplinary research, evidence-based policy development, and related practice. Nevertheless, despite closely linked origins, the contemporary professions of public health and urban planning largely operate within the neoliberal framework of academic, political, and policy silos. A reinvigorated relationship between the two is fundamental to building and sustaining an effective “healthy built environment profession.” A recent comprehensive review of the burgeoning literature on healthy built environments identified an emergent theme which we have termed “Professional Development.” This literature relates to the development of relationships between health and built environment professionals. It covers case studies illustrating good practice models for policy change, as well as ways professionals can work to translate research into policy. Intertwined with this empirical research is a dialogue on theoretical tensions emerging as health and built environment practitioners and researchers seek to establish mutual understanding and respect. The nature of evidence required to justify policy change, for example, has surfaced as an area of asynchrony between accepted disciplinary protocols. Our paper discusses this important body of research with a view to initiating and supporting the ongoing development of an interdisciplinary profession of healthy planning. PMID:23028393

[Estimation on value of water and soil conservation of agricultural ecosystems in Xi' an metropolitan, Northwest China].

PubMed

Yang, Wen-yan; Zhou, Zhong-xue

2014-12-01

With the urban eco-environment increasingly deteriorating, the ecosystem services provided by modern urban agriculture are exceedingly significant to maintain and build more suitable environment in a city. Taking Xi' an metropolitan as the study area, based on remote sensing data, DEM data and the economic and social statistics data, the water and soil conservation service of the agricultural ecosystems was valued employing the remote sensing and geographic information system method, covering the reduction values on land waste, soil fertility loss and sediment loss from 2000 to 2011, and analyzed its changes in time and space. The results showed that during the study period, the total value of water and soil conservation service provided by agricultural systems in Xi' an metropolitan was increased by 46,086 and 33.008 billion yuan respectively from period of 2000 to 2005 and from 2005 to 2011. The cultivated land (including grains, vegetables and other farming land), forest (including orchard) and grassland provided higher value on the water and soil conservation service than waters and other land use. Ecosystem service value of water and soil conserva- tion provided by agriculture was gradually decreasing from the southern to the northern in Xi' an metropolitan. There were significantly positive relationship between the ecosystem service value and the vegetation coverage. Forest, orchard and grassland distributed intensively in the southern which had higher vegetation coverage than in northern where covered by more cultivated land, sparse forest and scattered orchard. There were significantly negative correlation between the urbanization level and the value of water and soil conservation. The higher level of urbanization, the lower value there was from built-up area to suburban and to countryside within Xi' an metropolitan.

Socio-economic and ecological transformations of the peri-urban region of Gurgaon: an analysis of the trickle-down effect in the post globalization era

NASA Astrophysics Data System (ADS)

Yadav, A.; Punia, M.

2014-11-01

Economic processes are a manifestation of dynamic complex interdependent array of factors which involves resources, technology and an acting innovative human mind. Production, growth and development are the processes which has vast number of complex drivers, determinants and factors. Innovation, research, diffusion and dissemination are vital instrument of the economic processes of production, which are part of education. Whereas ecological transformations can be corroborated and analyzed by integrating remote sensing based information related to expansion of built-up area beyond city boundaries, extending to peripheries. City reflect economic, environmental, technological and social processes in their change, yet all are in turn profoundly driven by the urban spatial expansion. Metropolitan cities reflects expansion of existing urban and peri-urban areas with a significant socio-ecological transformation in terms of employment, education, and work force participation and land use changes. From the point of view of New Economic Geography (NEG) Theory 2009, the growth dynamic of metros is influenced by their proximity and dependence to a metropolis and the probable spillover effect. Entry point of discussion is the change in production of space in the post globalization era. It attempts to understand city morphology by using remote sensing datasets of LISS IV, IRS-P6 of 5.8 m spatial resolution for 2008 and 2013 and used Gurgaon Municipal Corporation's (GMC) ward boundary to represent socio-political meaning of this expansion and ways of life within the suburb. To understand how city works, detailed analysis related occupational structure, education and informality of ward 31 of Gurgaon and two villages namely Behlpa, Fazalwas and ward 11 of Nuh ( Mewat) along with the village Gabsanpur is attempted as the spatial units of study.

Assessment of Debris Flow Hazards, North Mountain, Phoenix, AZ

NASA Astrophysics Data System (ADS)

Reavis, K. J.; Wasklewicz, T. A.

2014-12-01

Urban sprawl in many western U.S. cities has expanded development onto alluvial fans. In the case of metropolitan Phoenix, AZ (MPA), urban sprawl has led to an exponential outward growth into surrounding mountainous areas and onto alluvial fans. Building on alluvial fans places humans at greater risk to flooding and debris flow hazards. Recent research has shown debris flows often supply large quantities of material to many alluvial fans in MPA. However, the risk of debris flows to built environments is relatively unknown. We use a 2D debris flow modeling approach, aided by high-resolution airborne LiDAR and terrestrial laser scanning (TLS) topographic data, to examine debris flow behavior in a densely populated portion of the MPA to assess the risk and vulnerability of debris flow damage to the built infrastructure. A calibrated 2D debris flow model is developed for a "known" recent debris flow at an undeveloped site in MPA. The calibrated model and two other model scenarios are applied to a populated area with historical evidence of debris flow activity. Results from the modeled scenarios show evidence of debris flow damage to houses built on the alluvial fan. Debris flow inundation is also evident on streets on the fan. We use housing values and building damage to estimate the costs assocaited with various modeled debris flow scenarios.

Urban flood risk mitigation: from vulnerability assessment to resilient city

NASA Astrophysics Data System (ADS)

Serre, D.; Barroca, B.

2009-04-01

Urban flood risk mitigation: from vulnerability assessment to resilient city Bruno Barroca1, Damien Serre2 1Laboratory of Urban Engineering, Environment and Building (L G U E H) - Université de Marne-la-Vallée - Pôle Ville, 5, Bd Descartes - Bâtiment Lavoisier - 77454 Marne la Vallée Cedex 2 - France 2City of Paris Engineering School, Construction - Environment Department, 15 rue Fénelon, 75010 Paris, France In France, as in Europe and more generally throughout the world, river floods have been increasing in frequency and severity over the last ten years, and there are more instances of rivers bursting their banks, aggravating the impact of the flooding of areas supposedly protected by flood defenses. Despite efforts made to well maintain the flood defense assets, we often observe flood defense failures leading to finally increase flood risk in protected area during major flood events. Furthermore, flood forecasting models, although they benefit continuous improvements, remain partly inaccurate due to uncertainties populated all along data calculation processes. These circumstances obliged stakeholders and the scientific communities to manage flood risk by integrating new concepts like stakes management, vulnerability assessments and more recently urban resilience development. Definitively, the goal is to reduce flood risk by managing of course flood defenses and improving flood forecasting models, but also stakes and vulnerability of flooded areas to achieve urban resilience face to flood events. Vulnerability to flood is essentially concentrated in urban areas. Assessing vulnerability of a city is very difficult. Indeed, urban area is a complex system composed by a sum of technical sub-systems as complex as the urban area itself. Assessing city vulnerability consists in talking into account each sub system vulnerability and integrating all direct and indirect impacts generally depending from city shape and city spatial organization. At this time, although some research activities have been undertaken, there are no specific methods and tools to assess flood vulnerability at the scale of the city. Indeed, by studying literature we can list some vulnerability indicators and a few Geographic Information System (GIS) tools. But generally indicators and GIS are not developed specifically at the city scale: often a regional scale is used. Analyzing vulnerability at this scale needs more accurate and formalized indicators and GIS tools. The second limit of existing GIS is temporal: even if vulnerability could be assessed and localized through GIS, such tools cannot assist city managers in their decision to efficiency recover after a severe flood event. Due to scale and temporal limits, methods and tools available to assess urban vulnerability need large improvements. Talking into account all these considerations and limits, our research is focusing on: • vulnerability indicators design; • recovery scenarios design; • GIS for city vulnerability assessment and recovery scenarios. Dealing with vulnerability indicators, the goal is to design a set of indicators of city sub systems. Sub systems are seen like assets of high value and complex and interdependent infrastructure networks (i.e. power supplies, communications, water, transport etc.). The infrastructure networks are critical for the continuity of economic activities as well as for the people's basic living needs. Their availability is also required for fast and effective recovery after flood disasters. The severity of flood damage therefore largely depends on the degree that both high value assets and critical urban infrastructure are affected, either directly or indirectly. To face the challenge of designing indicators, a functional model of the city system (and sub systems) has to be built to analyze the system response to flood solicitation. Then, a coherent and an efficient set of vulnerability of indicators could be built up. With such methods city stakeholders will be informed on how and how much their systems are vulnerable. It is a first level of information that has to be completed to become a real decision making tool. Indeed, we have seen that major floods cause almost always failures in the flood defense system. So potentially the city could face a flood event and managers recovery works. Knowing the vulnerability of the city, direct and indirect impacts, how can managers optimize recovery actions? Our research will focus first on proposing recovery scenarios based on the city system and second on vulnerability indicators to first limit damages during floods and to speed up recovery actions. At last, a GIS will be developed to assist stakeholders to take spatial measures to reduce city system weakness before a flood event and to help them to decide on how to optimize recovery actions after a flood event. Dealing with these two temporal scales will allow obtaining more flood resilient cities.

Acute effects of visits to urban green environments on cardiovascular physiology in women: A field experiment.

PubMed

Lanki, Timo; Siponen, Taina; Ojala, Ann; Korpela, Kalevi; Pennanen, Arto; Tiittanen, Pekka; Tsunetsugu, Yuko; Kagawa, Takahide; Tyrväinen, Liisa

2017-11-01

Epidemiological studies have reported positive associations between the amount of green space in the living environment and mental and cardiovascular human health. In a search for effect mechanisms, field studies have found short-term visits to green environments to be associated with psychological stress relief. Less evidence is available on the effect of visits on cardiovascular physiology. To evaluate whether visits to urban green environments, in comparison to visits to a built-up environment, lead to beneficial short-term changes in indicators of cardiovascular health. Thirty-six adult female volunteers visited three different types of urban environments: an urban forest, an urban park, and a built-up city centre, in Helsinki, Finland. The visits consisted of 15min of sedentary viewing, and 30min of walking. During the visits, blood pressure and heart rate were measured, and electrocardiogram recorded for the determination of indicators of heart rate variability. In addition, levels of respirable ambient particles and environmental noise were monitored. Visits to the green environments were associated with lower blood pressure (viewing period only), lower heart rate, and higher indices of heart rate variability [standard deviation of normal-to-normal intervals (SDNN), high frequency power] than visits to the city centre. In the green environments, heart rate decreased and SDNN increased during the visit. Associations between environment and indicators of cardiovascular health weakened slightly after inclusion of particulate air pollution and noise in the models. Visits to urban green environments are associated with beneficial short-term changes in cardiovascular risk factors. This can be explained by psychological stress relief with contribution from reduced air pollution and noise exposure during the visits. Future research should evaluate the amount of exposure to green environments needed for longer-term benefits for cardiovascular health. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Policy change and governance at the wildland-urban interface: the case of post-wildfire impacts in Boise, Idaho

NASA Astrophysics Data System (ADS)

Lindquist, Eric

2013-04-01

In the summer of 2012 over 1.7 million acres (approximately 6900 sq kilometers) were burned from wildfires in the state of Idaho in the Western United States. While most of the these fires were in rural and wilderness areas, several significant fires occurred at the wildland-urban interface (WUI), threatening houses, communities and the built environment as never before. As the population of the Mountain West in the United States grows, the WUI (the area where homes are being built adjacent to traditionally wild or rural areas and the built environment encroaches on wildlands) is rapidly becoming an at risk area for human habitation. Efforts to make these areas more resilient and sustainable in the face of increasing fire risk, due to increasing drought and climate change, are resulting in efforts to change or adapt disaster response and planning policy. An increase in stakeholders, however, with diverse objectives and resources presents an opportunity to assess the current governance situation for policy change in response to wildland fires in the dynamic and complex context of the WUI. The research presented here will focus on the case of Treasure Valley region of southwest Idaho and Boise, the capitol city of Idaho. This region is illustrative of the growing urban western United States and the pressures from a growing population pushing into the WUI. This research frames fire policy and decision making at the wildland-urban interface within public policy process theory using the example of the summer of 2012 forest fires in Idaho (USA) and focuses on subsequents impact these fires are having on fire planning and policy in the Boise metropolitan region. The focus is on the diverse stakeholders (federal, state and regional agencies, tourism, agriculture and private sector interests, homeowner organizations, and fire response and recovery agencies) and their roles and responsibilities, their interactions, decision and policy processes, the use of science in decision making, post and pre disaster assessments, and subsequent policy changes. The conclusions will reflect on the outlook for the future of the WUI in regard to wildfire risk and response and on the contribution of policy process theory to this policy domain. This paper/poster addresses significant theoretical and empirical issues raised in the Call for Papers for NH7.1 "Spatial and temporal patterns of wildfires: models, theory and reality," including: pre-fire planning and risk management; post-fire evaluation; relation between wildfires and social changes; and the influence of weather and climate change on wildfire activity.

Ground-Coupled Heating-Cooling Systems in Urban Areas: How Sustainable Are They?

ERIC Educational Resources Information Center

Younger, Paul L.

2008-01-01

Ground-coupled heating-cooling systems (GCHCSs) exchange heat between the built environment and the subsurface using pipework buried in trenches or boreholes. If heat pumps in GCHCSs are powered by "green electricity," they offer genuine carbon-free heating-cooling; for this reason, there has been a surge in the technology in recent…

Research the simulation model of the passenger travel behavior in urban rail platform

NASA Astrophysics Data System (ADS)

Wang, Yujia; Yin, Xiangyong

2017-05-01

Based on the results of the research on the platform of the Beijing Chegongzhuang subway station in the line 2, the passenger travel behavior in urban rail platform is divided into 4 parts, which are the enter passenger walking, the passenger waiting distribution and queuing up before the door, passenger boarding and alighting and the alighting passengers walking, according to the social force model, simulation model was built based on Matlab software. Combined with the actual data of subway the Chegongzhuang subway station in the line 2, the simulation results show that the social force model is effective.

Development of land-use regression models for fine particles and black carbon in peri-urban South India.

PubMed

Sanchez, Margaux; Ambros, Albert; Milà, Carles; Salmon, Maëlle; Balakrishnan, Kalpana; Sambandam, Sankar; Sreekanth, V; Marshall, Julian D; Tonne, Cathryn

2018-09-01

Land-use regression (LUR) has been used to model local spatial variability of particulate matter in cities of high-income countries. Performance of LUR models is unknown in less urbanized areas of low-/middle-income countries (LMICs) experiencing complex sources of ambient air pollution and which typically have limited land use data. To address these concerns, we developed LUR models using satellite imagery (e.g., vegetation, urbanicity) and manually-collected data from a comprehensive built-environment survey (e.g., roads, industries, non-residential places) for a peri-urban area outside Hyderabad, India. As part of the CHAI (Cardiovascular Health effects of Air pollution in Telangana, India) project, concentrations of fine particulate matter (PM 2.5 ) and black carbon were measured over two seasons at 23 sites. Annual mean (sd) was 34.1 (3.2) μg/m 3 for PM 2.5 and 2.7 (0.5) μg/m 3 for black carbon. The LUR model for annual black carbon explained 78% of total variance and included both local-scale (energy supply places) and regional-scale (roads) predictors. Explained variance was 58% for annual PM 2.5 and the included predictors were only regional (urbanicity, vegetation). During leave-one-out cross-validation and cross-holdout validation, only the black carbon model showed consistent performance. The LUR model for black carbon explained a substantial proportion of the spatial variability that could not be captured by simpler interpolation technique (ordinary kriging). This is the first study to develop a LUR model for ambient concentrations of PM 2.5 and black carbon in a non-urban area of LMICs, supporting the applicability of the LUR approach in such settings. Our results provide insights on the added value of manually-collected built-environment data to improve the performance of LUR models in settings with limited data availability. For both pollutants, LUR models predicted substantial within-village variability, an important feature for future epidemiological studies. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Vegetation placement for summer built surface temperature moderation in an urban microclimate.

PubMed

Millward, Andrew A; Torchia, Melissa; Laursen, Andrew E; Rothman, Lorne D

2014-06-01

Urban vegetation can mitigate increases in summer air temperature by reducing the solar gain received by buildings. To quantify the temperature-moderating influence of city trees and vine-covered buildings, a total of 13 pairs of temperature loggers were installed on the surfaces of eight buildings in downtown Toronto, Canada, for 6 months during the summer of 2008. One logger in each pair was shaded by vegetation while the other measured built surface temperature in full sunlight. We investigated the temperature-moderating benefits of solitary mature trees, clusters of trees, and perennial vines using a linear-mixed model and a multiple regression analysis of degree hour difference. We then assessed the temperature-moderating effect of leaf area, plant size and proximity to building, and plant location relative to solar path. During a period of high solar intensity, we measured an average temperature differential of 11.7 °C, with as many as 10-12 h of sustained cooler built surface temperatures. Vegetation on the west-facing aspect of built structures provided the greatest temperature moderation, with maximum benefit (peak temperature difference) occurring late in the afternoon. Large mature trees growing within 5 m of buildings showed the greatest ability to moderate built surface temperature, with those growing in clusters delivering limited additional benefit compared with isolated trees. Perennial vines proved as effective as trees at moderating rise in built surface temperature to the south and west sides of buildings, providing an attractive alternative to shade trees where soil volume and space are limited.

Vegetation Placement for Summer Built Surface Temperature Moderation in an Urban Microclimate

NASA Astrophysics Data System (ADS)

Millward, Andrew A.; Torchia, Melissa; Laursen, Andrew E.; Rothman, Lorne D.

2014-06-01

Urban vegetation can mitigate increases in summer air temperature by reducing the solar gain received by buildings. To quantify the temperature-moderating influence of city trees and vine-covered buildings, a total of 13 pairs of temperature loggers were installed on the surfaces of eight buildings in downtown Toronto, Canada, for 6 months during the summer of 2008. One logger in each pair was shaded by vegetation while the other measured built surface temperature in full sunlight. We investigated the temperature-moderating benefits of solitary mature trees, clusters of trees, and perennial vines using a linear-mixed model and a multiple regression analysis of degree hour difference. We then assessed the temperature-moderating effect of leaf area, plant size and proximity to building, and plant location relative to solar path. During a period of high solar intensity, we measured an average temperature differential of 11.7 °C, with as many as 10-12 h of sustained cooler built surface temperatures. Vegetation on the west-facing aspect of built structures provided the greatest temperature moderation, with maximum benefit (peak temperature difference) occurring late in the afternoon. Large mature trees growing within 5 m of buildings showed the greatest ability to moderate built surface temperature, with those growing in clusters delivering limited additional benefit compared with isolated trees. Perennial vines proved as effective as trees at moderating rise in built surface temperature to the south and west sides of buildings, providing an attractive alternative to shade trees where soil volume and space are limited.

The structure, function and value of urban forests in California communities

Treesearch

E. Gregory McPherson; Qingfu Xiao; Natalie S. van Doorn; John de Goede; Jacquelyn Bjorkman; Allan Hollander; Ryan M. Boynton; James F. Quinn; James H. Thorne

2017-01-01

This study used tree data from field plots in urban areas to describe forest structure in urban areas throughout California. The plot data were used with numerical models to calculate several ecosystem services produced by trees. A series of transfer functions were calculated to scale-up results from the plots to the landscape using urban tree canopy (UTC) mapped at 1-...

Land use planning using transit oriented development concept: Case study: Salaya station

NASA Astrophysics Data System (ADS)

Jarritthai, Supanee; Techpeeraparnich, Wasaporn

2017-10-01

The urban sprawl of Bangkok has increased with a motorization rate along with the expansion of the road network to adjacent cities. Nakhonpathom province, located at the southern edge of Bangkok has been affected by the urban sprawl. One of Nakhonpathom's Districts named "Salaya" Salaya has been quickly urbanized due to the establishment of many large academic institutes, such as universities, colleges and high schools as well as many commercial shopping malls. The period of 2013-2017, the Thai government introduced sustainable urban planning policy and promoted the use of public transportation systems. The Light Red Line railway extension of the Bangkok Metro Transit system will soon be constructed and the current Salaya Station will be replaced with new station. Many railway expansion projects will be built, should be designed by using transit-oriented development (TOD) scheme. This paper explores demographic information of the area, the demands of the community and relevant stakeholders for designing of the area using TOD. The proposed land use planning is designed based on the existing condition of the area as much as possible to meet the TOD standard and stakeholders' requirement. The result revealed that the guidelines of transit oriented development concept were of importance not only for planning of urban land use, supporting public transport, but also improving the quality of life.

Assessing the Urban Heat Island Effect Across Biomes in the Continental USA Using Landsat and MODIS

NASA Technical Reports Server (NTRS)

Imhoff, Marc L.; Bounoua, L.; Zhang, Ping; Wolfe, Robert

2011-01-01

Impervious surface area (ISA) from the Landsat TM and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) skin temperature amplitude and its relationship to development intensity, size, and ecological setting for 38 of the most populous cities in the continental United States. Development intensity zones based on %ISA are defined across urban gradients and used to stratify sampling of LST and NDVI. We find that ecological context significantly influences the amplitude of summer daytime UHI (urban - rural temperature difference) with the largest 8 C (average) for cities built in mixed forest biomes. For all cities ISA is the primary driver for increase in temperature explaining 70% of the total variance. Annually, urban areas are warmer than the non-urban fringe by 2.9 C, except in biomes with arid and semiarid climates. The average amplitude of the UHI is asymmetric with a 4.3 C difference in summer and 1.3 C in winter. In desert environments, UHI's point to a possible heat sink effect. Results show that the urban heat island amplitude increases with city size and is seasonally asymmetric for a large number of cities across most biomes. The implications are that for urban areas developed within forested ecosystems the summertime UHI can be quite high relative to the wintertime UHI suggesting that the residential energy consumption required for summer cooling is likely to increase with urban growth within those biomes.

Geo-information for sustainable urban development of Greater Dhaka City, Bangladesh

NASA Astrophysics Data System (ADS)

Günther, Andreas; Asaduzzaman, Atm; Bahls, Rebecca; Ludwig, Rüdiger; Ashraful Kamal, Mohammad; Nahar Faruqa, Nurun

2015-04-01

Greater Dhaka City (including Dhaka and five adjacent municipal areas) is one of the fastest developing urban regions in the world. Densely build-up areas in the developed metropolitan area of Dhaka City are subject to extensive restructuring as common six-storied buildings are replaced by higher and heavier constructions. Additional stories are built on existing houses, frequently exceeding the allowable bearing pressure on the subsoil as supported by the foundations. In turn, newly developing areas are projected in marshy areas modified by extensive, largely unengineered landfills. In many areas, these terrains bear unfavorable building ground conditions, and reliable geospatial information is a major prerequisite for risk-sensitive urban planning. Within a collaborative technical cooperation project between Bangladesh and Germany, BGR supports GSB in the provision of geo-information for the Capital Development authority (RAJUK). For general urban planning, RAJUK successively develops a detailed area plan (DAP) at scale 1 : 50000 for the whole Greater Dhaka City area. Geospatial information have not been considered in the present DAP. Within the project, GSB prepared a detailed geomorphologic map matching the DAP both in areal extent and scale. The geomorphological setting can be used as an important spatial proxy for the characterization of the subsurface since highly segmented, elevated terraces consisting of consolidated sandy Pliocene deposits overlain by stiff Plio-Pleistocene sediments are sharply bordered by low lying-areas. The floodplain and marsh areas are consisting of thick, mechanically weak Holocene fluvial sandy-silty sediments that are sometimes alternated by organic layers. A first expert-based engineering geological reclassification of the geomorphological map resulting in five building ground suitability classes is highly supported by the spatial analysis of extensive archive borehole information consisting of depth-continuous standard penetration test (SPT) observations, engineering geological sample analyses and lithological profiles. The database compiled within the project currently contains more than 1600 locations. The joining of the spatial geomorphological information with the borehole data allows a specific characterization of the building ground classes in terms of bearing capacities for different foundation designs, earthquake-induced subsoil liquefaction potentials and depth-to-engineering rock head considerations. First-order hazard and cost scenarios for several general types of projected settlements can already be broadly evaluated with the data presented in a small scale (DAP scale). However, detailed building ground surveys have to be performed at larger spatial scales (1 : 10000 - 1 : 5000) in areas assigned for new settlements. These involve regular spaced borehole observations, 3-D modeling of the subsurface and geophysical loggings. Within the project, specific representative pilot areas in different geomorphological settings are defined where detailed geospatial building ground investigations are conducted, providing a robust basis for sustainable urban planning related to natural and technological hazards and their associated risks.

Remote Sensing of the Urban Heat Island Effect Across Biomes in the Continental USA

NASA Technical Reports Server (NTRS)

Imhoff, Marc L.; Zhang, Ping; Wolfe, Robert E.; Bounoua, Lahouari

2010-01-01

Impervious surface area (ISA) from the Landsat TM-based NLCD 2001 dataset and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) skin temperature amplitude and its relationship to development intensity, size, and ecological setting for 38 of the most populous cities in the continental United States. Development intensity zones based on %ISA are defined for each urban area emanating outward from the urban core to the nonurban rural areas nearby and used to stratify sampling for land surface temperatures and NDVI. Sampling is further constrained by biome and elevation to insure objective intercomparisons between zones and between cities in different biomes permitting the definition of hierarchically ordered zones that are consistent across urban areas in different ecological setting and across scales. We find that ecological context significantly influences the amplitude of summer daytime UHI (urban-rural temperature difference) the largest (8 C average) observed for cities built in biomes dominated by temperate broadleaf and mixed forest. For all cities combined, ISA is the primary driver for increase in temperature explaining 70% of the total variance in LST. On a yearly average, urban areas are substantially warmer than the non-urban fringe by 2.9 C, except for urban areas in biomes with arid and semiarid climates. The average amplitude of the UHI is remarkably asymmetric with a 4.3 C temperature difference in summer and only 1.3 C in winter. In desert environments, the LST's response to ISA presents an uncharacteristic "U-shaped" horizontal gradient decreasing from the urban core to the outskirts of the city and then increasing again in the suburban to the rural zones. UHI's calculated for these cities point to a possible heat sink effect. These observational results show that the urban heat island amplitude both increases with city size and is seasonally asymmetric for a large number of cities across most biomes. The implications are that for urban areas developed within forested ecosystems the summertime UHI can be quite high relative to the wintertime UHI suggesting that the residential energy consumption required for summer cooling is likely to increase with urban growth within those biomes.

Quantitative estimation of dust fall and smoke particles in Quetta Valley*

PubMed Central

Sami, Muhammad; Waseem, Amir; Akbar, Sher

2006-01-01

Tightening of air quality standards for populated urban areas has led to increasing attention to assessment of air quality management areas, where violation of air quality standards occurs, and development of control strategies to eliminate such violation of air quality standards. The Quetta urban area is very densely built and has heavy motorized traffic. The increase of emissions mainly from traffic and industry are responsible for the increase in atmospheric pollution levels during the last years. The dust examined in the current study was collected by both deposit gauge and Petri dish methods at various sites of Quetta Valley. Smoke particles were obtained by bladder method from the exhausts of various types of motor vehicles. The concentration of lead found in the smoke ranged from 1.5×10−6 to 4.5×10−6. PMID:16773727

Determining urban land uses through building-associated element attributes derived from lidar and aerial photographs

NASA Astrophysics Data System (ADS)

Meng, Xuelian

Urban land-use research is a key component in analyzing the interactions between human activities and environmental change. Researchers have conducted many experiments to classify urban or built-up land, forest, water, agriculture, and other land-use and land-cover types. Separating residential land uses from other land uses within urban areas, however, has proven to be surprisingly troublesome. Although high-resolution images have recently become more available for land-use classification, an increase in spatial resolution does not guarantee improved classification accuracy by traditional classifiers due to the increase of class complexity. This research presents an approach to detect and separate residential land uses on a building scale directly from remotely sensed imagery to enhance urban land-use analysis. Specifically, the proposed methodology applies a multi-directional ground filter to generate a bare ground surface from lidar data, then utilizes a morphology-based building detection algorithm to identify buildings from lidar and aerial photographs, and finally separates residential buildings using a supervised C4.5 decision tree analysis based on the seven selected building land-use indicators. Successful execution of this study produces three independent methods, each corresponding to the steps of the methodology: lidar ground filtering, building detection, and building-based object-oriented land-use classification. Furthermore, this research provides a prototype as one of the few early explorations of building-based land-use analysis and successful separation of more than 85% of residential buildings based on an experiment on an 8.25-km2 study site located in Austin, Texas.

Developing a 1 km resolution daily air temperature dataset for urban and surrounding areas in the conterminous United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xiaoma; Zhou, Yuyu; Asrar, Ghassem R.

High spatiotemporal resolution air temperature (Ta) datasets are increasingly needed for assessing the impact of temperature change on people, ecosystems, and energy system, especially in the urban domains. However, such datasets are not widely available because of the large spatiotemporal heterogeneity of Ta caused by complex biophysical and socioeconomic factors such as built infrastructure and human activities. In this study, we developed a 1-km gridded dataset of daily minimum Ta (Tmin) and maximum Ta (Tmax), and the associated uncertainties, in urban and surrounding areas in the conterminous U.S. for the 2003–2016 period. Daily geographically weighted regression (GWR) models were developedmore » and used to interpolate Ta using 1 km daily land surface temperature and elevation as explanatory variables. The leave-one-out cross-validation approach indicates that our method performs reasonably well, with root mean square errors of 2.1 °C and 1.9 °C, mean absolute errors of 1.5 °C and 1.3 °C, and R 2 of 0.95 and 0.97, for Tmin and Tmax, respectively. The resulting dataset captures reasonably the spatial heterogeneity of Ta in the urban areas, and also captures effectively the urban heat island (UHI) phenomenon that Ta rises with the increase of urban development (i.e., impervious surface area). The new dataset is valuable for studying environmental impacts of urbanization such as UHI and other related effects (e.g., on building energy consumption and human health). The proposed methodology also shows a potential to build a long-term record of Ta worldwide, to fill the data gap that currently exists for studies of urban systems.« less

Wind flow in an urban environment.

PubMed

Dutt, A J

1991-10-01

The wind environment at ground leven in built-up areas is influenced by the extremely complex interaction amongst incident wind, mean vertical velocity gradient, turbulence and the shapes, sizes and layouts of building. Random layout of buildings could generate zones of overspeed and vortices in the connecting passage way between buildings, terraces, opensided shelters, courtyards, which could potentially cause unpleasantness, hazard from resuspended particulates, and airborne rain penetration into the buildings. The paper presents the results of two case studies comprising field measurements made within the Kent Ridge Campus, National University of Singapore, using DANTEC 54N10 Multichannel Flow Analyser and Probes. Results are presented in terms of non-dimensional windspeed coefficients. It is concluded that there is significant increase in windspeed due to channel and venturi effects. This information provides useful guidelines for building plans and layouts to the architects and engineers.

Bright is the new black—multi-year performance of high-albedo roofs in an urban climate

NASA Astrophysics Data System (ADS)

Gaffin, S. R.; Imhoff, M.; Rosenzweig, C.; Khanbilvardi, R.; Pasqualini, A.; Kong, A. Y. Y.; Grillo, D.; Freed, A.; Hillel, D.; Hartung, E.

2012-03-01

High-albedo white and cool roofing membranes are recognized as a fundamental strategy that dense urban areas can deploy on a large scale, at low cost, to mitigate the urban heat island effect. We are monitoring three generic white membranes within New York City that represent a cross section of the dominant white membrane options for US flat roofs: (1) an ethylene-propylene-diene monomer (EPDM) rubber membrane; (2) a thermoplastic polyolefin (TPO) membrane; and (3) an asphaltic multi-ply built-up membrane coated with white elastomeric acrylic paint. The paint product is being used by New York City’s government for the first major urban albedo enhancement program in its history. We report on the temperature and related albedo performance of these three membranes at three different sites over a multi-year period. The results indicate that the professionally installed white membranes are maintaining their temperature control effectively and are meeting the Energy Star Cool Roofing performance standards requiring a three-year aged albedo above 0.50. The EPDM membrane shows evidence of low emissivity; however this had the interesting effect of avoiding any ‘winter heat penalty’ for this building. The painted asphaltic surface shows high emissivity but lost about half of its initial albedo within two years of installation. Given that the acrylic approach is such an important ‘do-it-yourself’, low-cost, retrofit technique, and, as such, offers the most rapid technique for increasing urban albedo, further product performance research is recommended to identify conditions that optimize its long-term albedo control. Even so, its current multi-year performance still represents a significant albedo enhancement for urban heat island mitigation.

Uncertainties in mapping forest carbon in urban ecosystems.

PubMed

Chen, Gang; Ozelkan, Emre; Singh, Kunwar K; Zhou, Jun; Brown, Marilyn R; Meentemeyer, Ross K

2017-02-01

Spatially explicit urban forest carbon estimation provides a baseline map for understanding the variation in forest vertical structure, informing sustainable forest management and urban planning. While high-resolution remote sensing has proven promising for carbon mapping in highly fragmented urban landscapes, data cost and availability are the major obstacle prohibiting accurate, consistent, and repeated measurement of forest carbon pools in cities. This study aims to evaluate the uncertainties of forest carbon estimation in response to the combined impacts of remote sensing data resolution and neighborhood spatial patterns in Charlotte, North Carolina. The remote sensing data for carbon mapping were resampled to a range of resolutions, i.e., LiDAR point cloud density - 5.8, 4.6, 2.3, and 1.2 pt s/m 2 , aerial optical NAIP (National Agricultural Imagery Program) imagery - 1, 5, 10, and 20 m. Urban spatial patterns were extracted to represent area, shape complexity, dispersion/interspersion, diversity, and connectivity of landscape patches across the residential neighborhoods with built-up densities from low, medium-low, medium-high, to high. Through statistical analyses, we found that changing remote sensing data resolution introduced noticeable uncertainties (variation) in forest carbon estimation at the neighborhood level. Higher uncertainties were caused by the change of LiDAR point density (causing 8.7-11.0% of variation) than changing NAIP image resolution (causing 6.2-8.6% of variation). For both LiDAR and NAIP, urban neighborhoods with a higher degree of anthropogenic disturbance unveiled a higher level of uncertainty in carbon mapping. However, LiDAR-based results were more likely to be affected by landscape patch connectivity, and the NAIP-based estimation was found to be significantly influenced by the complexity of patch shape. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessing the effects of land use spatial structure on urban heat islands using HJ-1B remote sensing imagery in Wuhan, China

NASA Astrophysics Data System (ADS)

Wu, Hao; Ye, Lu-Ping; Shi, Wen-Zhong; Clarke, Keith C.

2014-10-01

Urban heat islands (UHIs) have attracted attention around the world because they profoundly affect biological diversity and human life. Assessing the effects of the spatial structure of land use on UHIs is essential to better understanding and improving the ecological consequences of urbanization. This paper presents the radius fractal dimension to quantify the spatial variation of different land use types around the hot centers. By integrating remote sensing images from the newly launched HJ-1B satellite system, vegetation indexes, landscape metrics and fractal dimension, the effects of land use patterns on the urban thermal environment in Wuhan were comprehensively explored. The vegetation indexes and landscape metrics of the HJ-1B and other remote sensing satellites were compared and analyzed to validate the performance of the HJ-1B. The results have showed that land surface temperature (LST) is negatively related to only positive normalized difference vegetation index (NDVI) but to Fv across the entire range of values, which indicates that fractional vegetation (Fv) is an appropriate predictor of LST more than NDVI in forest areas. Furthermore, the mean LST is highly correlated with four class-based metrics and three landscape-based metrics, which suggests that the landscape composition and the spatial configuration both influence UHIs. All of them demonstrate that the HJ-1B satellite has a comparable capacity for UHI studies as other commonly used remote sensing satellites. The results of the fractal analysis show that the density of built-up areas sharply decreases from the hot centers to the edges of these areas, while the densities of water, forest and cropland increase. These relationships reveal that water, like forest and cropland, has a significant effect in mitigating UHIs in Wuhan due to its large spatial extent and homogeneous spatial distribution. These findings not only confirm the applicability and effectiveness of the HJ-1B satellite system for studying UHIs but also reveal the impacts of the spatial structure of land use on UHIs, which is helpful for improving the planning and management of the urban environment.

Reshaping the Built Environment to Reduce Environmental and Public Health Impacts of Summertime Heat

NASA Astrophysics Data System (ADS)

Rosenthal, J. E.; Bakewell, K.

2005-12-01

Many American cities are experiencing two types of warming trends in their local climate that due to global environmental change, and that due to local environmental change. Over the next five decades, urban areas within temperate regions may warm disproportionately compared to tropical and subtropical zones according to the IPCC Special Report on The Regional Impacts of Climate Change, and the frequency of very hot days in these climates is expected to approximately double for an increase of 2-3°C in the average summer temperature. As well, due to urbanized land-cover, air temperatures in cities can register 2 to 10 degrees F higher than in surrounding rural areas, resulting in a hotter environment, higher energy demand, and accelerated smog formation due to the urban heat island effect. Our previous research analyzed the temperature differences over time between NY Central Park (NYCP) station and 23 metropolitan regional weather stations classified according to distance and level of urbanization, and showed a heat island effect existing in NYC, with mean temperatures in the NYCP Station generally higher than the surrounding stations, ranging from 1.20 C to 3.02 C. A difference of at least 1 C already existed at the beginning of the 20th century between the mean temperature in NYC and its surrounding rural areas, and this difference increased over the twentieth century. Summertime heat can create heat stress and other health consequences for urban residents. In cities around the world, summer heat can lead to elevated mortality and morbidity rates, especially during extreme events. The epidemiological literature has identified factors in the built environment and demographic characteristics that can increase the risk of heat-related mortality. The elderly and people with pre-existing illnesses are especially vulnerable; also, being bedridden, living alone, and having poor access to public transportation or air-conditioned places. During the Chicago 1995 heat wave, risk of mortality was higher in the black community, and in those living in certain types of low-income and multi-tenant housing. Interventions in the built environment to promote urban heat island mitigation can reduce ambient temperatures, potentially reducing heat-related mortality rates in vulnerable populations, electricity consumption and air pollutant emissions, and slow ozone formation, an important health stressor. These mitigation measures may also serve as adaptive responses for a range of potential future climate conditions. Here we review current research that assesses the health, air quality, and energy conservation benefits in cities from these interventions in the built environment, and discuss the techniques and research objectives of a new pilot community-based project to mitigate the heat island effect in the South Bronx, New York City through implementation of vegetated and high albedo roofing on residential and institutional buildings. Recent studies use mesoscale climate models and a variety of land-use and land-cover scenarios to project the effects of increasing vegetative fraction and albedo within metropolitan regions and to evaluate the impacts of measures that may serve both as adaptive responses to current conditions and mitigation for future climate variability. Through this perspective, we address the questions: What urban design approaches make for resilient cities in a changing environment? What costs and benefits may be expected by the adoption of heat island mitigation techniques within the New York metropolitan region?

Geospatial analysis of spaceborne remote sensing data for assessing disaster impacts and modeling surface runoff in the built-environment

NASA Astrophysics Data System (ADS)

Wodajo, Bikila Teklu

Every year, coastal disasters such as hurricanes and floods claim hundreds of lives and severely damage homes, businesses, and lifeline infrastructure. This research was motivated by the 2005 Hurricane Katrina disaster, which devastated the Mississippi and Louisiana Gulf Coast. The primary objective was to develop a geospatial decision-support system for extracting built-up surfaces and estimating disaster impacts using spaceborne remote sensing satellite imagery. Pre-Katrina 1-m Ikonos imagery of a 5km x 10km area of Gulfport, Mississippi, was used as source data to develop the built-up area and natural surfaces or BANS classification methodology. Autocorrelation of 0.6 or higher values related to spectral reflectance values of groundtruth pixels were used to select spectral bands and establish the BANS decision criteria of unique ranges of reflectance values. Surface classification results using GeoMedia Pro geospatial analysis for Gulfport sample areas, based on BANS criteria and manually drawn polygons, were within +/-7% of the groundtruth. The difference between the BANS results and the groundtruth was statistically not significant. BANS is a significant improvement over other supervised classification methods, which showed only 50% correctly classified pixels. The storm debris and erosion estimation or SDE methodology was developed from analysis of pre- and post-Katrina surface classification results of Gulfport samples. The SDE severity level criteria considered hurricane and flood damages and vulnerability of inhabited built-environment. A linear regression model, with +0.93 Pearson R-value, was developed for predicting SDE as a function of pre-disaster percent built-up area. SDE predictions for Gulfport sample areas, used for validation, were within +/-4% of calculated values. The damage cost model considered maintenance, rehabilitation and reconstruction costs related to infrastructure damage and community impacts of Hurricane Katrina. The developed models were implemented for a study area along I-10 considering the predominantly flood-induced damages in New Orleans. The BANS methodology was calibrated for 0.6-m QuickBird2 multispectral imagery of Karachi Port area in Pakistan. The results were accurate within +/-6% of the groundtruth. Due to its computational simplicity, the unit hydrograph method is recommended for geospatial visualization of surface runoff in the built-environment using BANS surface classification maps and elevations data. Key words. geospatial analysis, satellite imagery, built-environment, hurricane, disaster impacts, runoff.

Mitigating Wildfire Risk in the Wildland Urban Interface: The Role of Regulations

Treesearch

Cheryl R. Renner; Margaret Reams; Terry Haines

2006-01-01

The growth of residential communities within forest areas throughout the country, and particularly in the West, has increased the danger to life and property from uncontrolled wildfire. The conflict of permanent residential settlements built next to a fire-adapted ecosystem has been further exacerbated by 100 years of fire suppression and an extended drought in the...

The Forest Types and Ages Cleared for Land Development in Puerto Rico.

Treesearch

Todd Kennaway; E. H. Helmer

2007-01-01

On the Caribbean island of Puerto Rico, forest, urban/built-up, and pasture lands have replaced most formerly cultivated lands. The extent and age distribution of each forest type that undergoes land development, however, is unknown. This study assembles a time series of four land cover maps for Puerto Rico. The time series includes two digitized paper maps of land...

Natural Ventilation of Buildings through Light Shafts. Design-Based Solution Proposals

NASA Astrophysics Data System (ADS)

Ángel Padilla-Marcos, Miguel; Meiss, Alberto; Feijó-Muñoz, Jesús

2017-10-01

This work analyses how the built environment affects the quality of the air to be introduced into buildings from light shafts. Several factors such as urban environment and building design intervene in the ability of the light shaft to produce its air change process. Urban areas continuously pollute the air in cities which affects the human health and the environment sustainability. Poor air quality outside buildings supposes a big energy waste to promote an acceptable air quality inside buildings. That requires a large flow rate to maintain the indoor air quality which is translated to an energy efficiency term. The main objective focuses on the impact of standardized architecture design in the quality of the indoor air dependent on the air change in the light shaft. The air change capacity of the outdoor space is numbered analysed using the concept of air change efficiency (ACE). ACE is determined by the built environment, the wind conditions and the design of the building containing light shafts. This concept is comparatively evaluated inside a control domain virtually defined to obtain the mean age of the air for a known air volume. The longer the light shaft in the wind direction is, the better the ACE is compared with other options. Light shafts up to 12 metres high are the most suitable in order to obtain acceptable efficiency results. Other studied cases verify that assumption. Different simplified tools for the technicians to evaluate the design of buildings containing light shafts are proposed. Some strategies of architectural design of buildings with light shafts to be used for ventilation are presented.

Cohort profile: Examining Neighbourhood Activities in Built Living Environments in London: the ENABLE London—Olympic Park cohort

PubMed Central

Ram, Bina; Nightingale, Claire M; Hudda, Mohammed T; Kapetanakis, Venediktos V; Ellaway, Anne; Cooper, Ashley R; Page, Angie; Lewis, Daniel; Cummins, Steven; Giles-Corti, Billie; Whincup, Peter H; Cook, Derek G; Rudnicka, Alicja R; Owen, Christopher G

2016-01-01

Purpose The Examining Neighbourhood Activities in Built Living Environments in London (ENABLE London) project is a natural experiment which aims to establish whether physical activity and other health behaviours show sustained changes among individuals and families relocating to East Village (formerly the London 2012 Olympics Athletes' Village), when compared with a control population living outside East Village throughout. Participants Between January 2013 and December 2015, 1497 individuals from 1006 households were recruited and assessed (at baseline) (including 392 households seeking social housing, 421 seeking intermediate and 193 seeking market rent homes). The 2-year follow-up rate is 62% of households to date, of which 57% have moved to East Village. Findings to date Assessments of physical activity (measured objectively using accelerometers) combined with Global Positioning System technology and Geographic Information System mapping of the local area are being used to characterise physical activity patterns and location among study participants and assess the attributes of the environments to which they are exposed. Assessments of body composition, based on weight, height and bioelectrical impedance, have been made and detailed participant questionnaires provide information on socioeconomic position, general health/health status, well-being, anxiety, depression, attitudes to leisure time activities and other personal, social and environmental influences on physical activity, including the use of recreational space and facilities in their residential neighbourhood. Future plans The main analyses will examine the changes in physical activity, health and well-being observed in the East Village group compared with controls and the influence of specific elements of the built environment on observed changes. The ENABLE London project exploits a unique opportunity to evaluate a ‘natural experiment’, provided by the building and rapid occupation of East Village. Findings from the study will be generalisable to other urban residential housing developments, and will help inform future evidence-based urban planning. PMID:27793838

Radiofrequency Electromagnetic Field Map of Timisoara

NASA Astrophysics Data System (ADS)

Stefu, N.; Solyom, I.; Arama, A.

2015-12-01

There are many electromagnetic field (EMF) sources nowadays acting simultaneously, especially in urban areas, making the theoretical estimation of electromagnetic power at ground level very difficult. This paper reports on EMF maps built with measurements collected in Timisoara, at various radiofrequencies. A grid of 15×15 squares was built (approximate resolution 400m x 400m) and measurements of the average and maximum values of the electric field E, magnetic field H and total power density S at 0.9, 1.8 and 2.4 GHz were collected in every node of the grid. Positions of the nodes in terms of latitude and longitude were also collected. Maps were built presenting the spatial distribution of the measured quantities over Timisoara. Potential influences of EMF on public health are discussed.

Environmental Response of Small Urban Parks in Context of Dhaka City

NASA Astrophysics Data System (ADS)

Tabassum, S.

2018-01-01

Urban green spaces are essential element of urban life which, due to their structure and multi functionality, can play an exemplary role in the vitality and quality of urban life. Urban Parks are not only used as active recreational and leisure areas for its citizens but also an important catalyst for community development and enhancement. These spaces in the city act like its lungs and play a critical role in supporting the ecological and environmental system. In the dense urban areas, even Small Parks (less than one acre in size) can also contribute a lot to improve environmental quality of city life. In a populated city where it is difficult to incorporate large Public Parks, these small green area can complement large Public Park system. Accordingly the study is concerned to evaluate the environmental performances of Small Parks on the built environments of urban Dhaka. The analysis identifies that Small Parks has strong environmental impact, the intensity of which depends on the type and quality of its vegetation, its design parameters, connectivity and of course on surrounding urban morphology. And it is confirmed that park with more canopy tree is suitable for our environment and therefore a good combination of vegetation (wide canopy trees at periphery, medium canopy trees beside internal walkway and small canopy tree, shrub and grass cover elsewhere) are recommended for better environmental performance of Small Parks. The research will be an approach to find the ways and means to restore the Small Parks of Dhaka city to ensure the livability of the city and enhance the quality of city image.

The Wisconsin Assessment of the Social and Built Environment (WASABE): a multi-dimensional objective audit instrument for examining neighborhood effects on health.

PubMed

Malecki, Kristen C; Engelman, Corinne D; Peppard, Paul E; Nieto, F Javier; Grabow, Maggie L; Bernardinello, Milena; Bailey, Erin; Bersch, Andrew J; Walsh, Matthew C; Lo, Justin Y; Martinez-Donate, Ana

2014-11-13

Growing evidence suggests that mixed methods approaches to measuring neighborhood effects on health are needed. The Wisconsin Assessment of the Social and Built Environment (WASABE) is an objective audit tool designed as an addition to a statewide household-based health examination survey, the Survey of the Health of Wisconsin (SHOW), to objectively measure participant's neighborhoods. This paper describes the development and implementation of the WASABE and examines the instrument's ability to capture a range of social and built environment features in urban and rural communities. A systematic literature review and formative research were used to create the tool. Inter-rater reliability parameters across items were calculated. Prevalence and density of features were estimated for strata formed according to several sociodemographic and urbanicity factors. The tool is highly reliable with over 81% of 115 derived items having percent agreement above 95%. It captured variance in neighborhood features in for a diverse sample of SHOW participants. Sidewalk density in neighborhoods surrounding households of participants living at less than 100% of the poverty level was 67% (95% confidence interval, 55-80%) compared to 34% (25-44%) for those living at greater than 400% of the poverty level. Walking and biking trails were present in 29% (19-39%) of participant buffer in urban areas compared to only 7% (2-12%) in rural communities. Significant environmental differences were also observed for white versus non-white, high versus low income, and college graduates versus individuals with lower level of education. The WASABE has strong inter-rater reliability and validity properties. It builds on previous work to provide a rigorous and standardized method for systematically gathering objective built and social environmental data in a number of geographic settings. Findings illustrate the complex milieu of built environment features found in participants neighborhoods and have relevance for future research, policy, and community engagement purposes.

Identifying built environmental patterns using cluster analysis and GIS: Relationships with walking, cycling and body mass index in French adults

PubMed Central

2012-01-01

Background Socio-ecological models suggest that both individual and neighborhood characteristics contribute to facilitating health-enhancing behaviors such as physical activity. Few European studies have explored relationships between local built environmental characteristics, recreational walking and cycling and weight status in adults. The aim of this study was to identify built environmental patterns in a French urban context and to assess associations with recreational walking and cycling behaviors as performed by middle-aged adult residents. Methods We used a two-step procedure based on cluster analysis to identify built environmental patterns in the region surrounding Paris, France, using measures derived from Geographic Information Systems databases on green spaces, proximity facilities (destinations) and cycle paths. Individual data were obtained from participants in the SU.VI.MAX cohort; 1,309 participants residing in the Ile-de-France in 2007 were included in this analysis. Associations between built environment patterns, leisure walking/cycling data (h/week) and measured weight status were assessed using multinomial logistic regression with adjustment for individual and neighborhood characteristics. Results Based on accessibility to green spaces, proximity facilities and availability of cycle paths, seven built environmental patterns were identified. The geographic distribution of built environmental patterns in the Ile-de-France showed that a pattern characterized by poor spatial accessibility to green spaces and proximity facilities and an absence of cycle paths was found only in neighborhoods in the outer suburbs, whereas patterns characterized by better spatial accessibility to green spaces, proximity facilities and cycle paths were more evenly distributed across the region. Compared to the reference pattern (poor accessibility to green areas and facilities, absence of cycle paths), subjects residing in neighborhoods characterized by high accessibility to green areas and local facilities and by a high density of cycle paths were more likely to walk/cycle, after adjustment for individual and neighborhood sociodemographic characteristics (OR = 2.5 95%CI 1.4-4.6). Body mass index did not differ across patterns. Conclusions Built environmental patterns were associated with walking and cycling among French adults. These analyses may be useful in determining urban and public health policies aimed at promoting a healthy lifestyle. PMID:22620266

China's land cover and land use change from 1700 to 2005: Estimations from high-resolution satellite data and historical archives

NASA Astrophysics Data System (ADS)

Liu, Mingliang; Tian, Hanqin

2010-09-01

One of the major limitations in assessing the impacts of human activities on global biogeochemical cycles and climate is a shortage of reliable data on historical land cover and land use change (LCLUC). China had extreme discrepancies in estimating contemporary and historical patterns of LCLUC over the last 3 centuries because of its geographical complexity, long history of land use, and limited national surveys. This study aims to characterize the spatial and temporal patterns of China's LCLUC during 1700-2005 by reconstructing historical gridded data sets from high-resolution satellite data and long-term historical survey data. During this 300 year period, the major characteristics of LCLUC in China have been shrinking forest (decreased by 22%) and expanding cropland (increased by 42%) and urban areas (including urban and rural settlements, factories, quarries, mining, and other built-up land). New cropland areas have come almost equally from both forested and nonforested land. This study also revealed that substantial conversion between forest and woodland can be attributed to forest harvest, forest regeneration, and land degradation. During 1980-2005, LCLUC was characterized by shrinking cropland, expanding urban and forest areas, and large decadal variations on a national level. LCLUC in China showed significant spatial variations during different time periods, which were caused by spatial heterogeneity in vegetation, soils, and climate and regional imbalance in economy development. During 1700-2005, forests shrunk rapidly while croplands expanded in the northeast and southwest of China. During 1980-2005, we found a serious loss of cropland and urban sprawl in the eastern plain, north, and southeast regions of China and a large increase in forested area in the southeast and southwest regions. The reconstructed LCLUC data sets from this study could be used to assess the impacts of land use change on biogeochemical cycles, the water cycle, and the regional climate in China. To further eliminate uncertainties in this data set and make reliable projections of LCLUC for the future, we need to improve our understanding of the drivers of LCLUC and work toward developing an advanced, spatially explicit land use model.

Impact of urban built environment on urban short-distance taxi travel: the case of Shanghai

NASA Astrophysics Data System (ADS)

Wu, Zhuoye; Zhuo, Jian

2018-05-01

The excessive individual motorized transport is the main cause of urban congestion and generates negative consequences on urban environmental quality, energy consumption, infrastructure supply and urban security. Bicycle can compete effectively with automobile for short-distance travels within 3km. If we take action to encourage the rider to shift from automobile to bike for the short-distance travels, it leaves us a great chance to reduce the modal share of individual motorized mode. This paper focus on the spatial impact of built environment on short-distance taxi riders’ travel behaviour. The data sources include taxi trajectory data for a week, demographic data of the Sixth National Census, POI data. In this paper, we figure out the volumes and spatial distribution of short-distance taxi travel in the central city of Shanghai. We build a multiple regression model to quantitative analyze the impact of urban built environment on urban short-distance taxi travel. The findings explain the spatial distribution short-distance taxi travel. In the conclusion, some advice are provided on how planners change the spatial settings to discourage short-distance individual motorized travel.

[Analysis of urban forest landscape pattern in Hefei].

PubMed

Wu, Zemin; Wu, Wenyou; Gao, Jian; Zhang, Shaojie

2003-12-01

Based on the theory and methodology of landscape ecology, the landscape pattern of the study area (17.6 km2) in the downtown of Hefei was analyzed by using the techniques of RS, GPS and GIS. The object was to provide a comprehensive method to study urban forest structure and its function in environmental improvement. The results showed that there were 5 major landscape elements, i.e., building and hard pavement surface, water, road, urban forest, and general green land in the area. The landscape matrix was building and pavement surface, occupied 73.13% of total land. Road was the typical corridor element in the city and occupied 6.89%. Green land occupied 11.44%, in which, urban forest patch occupied 9.18%. There were 408 urban forest patches, with an area of 161.16 hm2. The average area of the patch was 0.396 hm2, and the maximum area was 12 hm2. 48% of urban forest patch was identified as small scale patches with < 500 m2 of area, and only 8.6% of them was larger than 1 hm2. The number of general green land patch was 255, with an area of 39.74 hm2, which accounted for 2.26% of land area, and its average and maximum area was 0.1558 hm2 and 3.86 hm2, respectively. There were 147 water patches, with an area of 149.93 hm2, and occupied 8.54% of land, and the average and maximum area of the patch was 1.02 hm2 and 16 hm2, respectively. In the study area, both of the Shannon-Weiner landscape diversity index and evenness were low, only 0.928 and 0.576, respectively. In addition, the dominance of urban forest patch and general green land was 0.39 showing that the two landscape elements had a certain influence on the environment of the study area. The concept of interior habitat for forest was introduced in this paper, which was employed to make a scale class system of urban forest patch. The threshold area with interior habitat for urban forest patch was 9800 m2, and there was 31.69 hm2 of interior habitat of urban forest in total, which occupied 19.7% of the total area of urban forest patch. This situation was not favorable for providing more habitats to support species diversity. It's suggested that the concept of interior habitat could be employed to identify urban forest patch, and a scale system of small scale patch of urban forest-middle patch-large patch-extra large patch was build in the paper. Based on this system, the ratio of different scales of urban forest patch in the study area should be 2:2:2:3. The authors also suggested that larger pieces (1.5-3.0 hm2) of urban forest patch should be built, and more urban forests should be established in the northeastern part of the city in the future.

Active transportation environments surrounding Canadian schools.

PubMed

O'Loghlen, Sean; Pickett, J William; Janssen, Ian

2011-01-01

Walking or cycling to school represents an opportunity for children to engage in physical activity. The study objectives were to: 1) describe active transportation policies, programs, and built environments of Canadian schools and their surrounding neighbourhoods, and 2) document variations based on urban-rural location and school type (primary vs. secondary vs. mixed primary/secondary schools). 397 schools from across Canada were studied. A school administrator completed a questionnaire and responses were used to assess schools' policies and programs related to active transportation and the safety and aesthetics of their respective neighbourhoods. Built environment features in a 1 km-radius circular buffer around each school were measured using geographic information systems. Greater than 70% of schools had passive policies (e.g., skateboards permitted on school grounds) and facilities (e.g., bicycle racks in secure area to avoid theft) to encourage bicycle and small-wheeled vehicle use. Less than 40% of schools had active programs designed to encourage active transportation, such as organized 'walk to school' days. Garbage in the streets, crime and substance abuse were barriers in most school neighbourhoods. Approximately 42% of schools were located on high-speed roads not amenable to active transportation and 14% did not have a sidewalk leading to the school. Secondary schools had less favourable active transportation policies/programs and neighbourhood safety/aesthetics compared to primary schools. Rural schools had less favourable built environments than urban schools. Canadian children, particularly those from rural areas, face a number of impediments to active transportation as a method of travelling to school.

Urban Morphological Dynamics in Santiago (chile): Proposing Sustainable Indicators from Remote Sensing

NASA Astrophysics Data System (ADS)

Hernández, H. J.; Gutiérrez, M. A.; Acuña, M. P.

2016-06-01

Latin America is one of the world's most urbanised regions, with more than 80% of inhabitants living in urban areas and over 50 cities with at least 1 million inhabitants. The concept of urban structure types (UST) allows the dynamics of a growing urban environment to be captured in its quantity and quality. They are defined as areas of homogenous appearance in the urban matrix with a recognisable mixture of built-up areas and open spaces. We used the vegetation-impervious-soil (V-I-S) model approach to classify and monitor different types of USTs in Santiago (~800 km2), Chile between 1985 and 2015. The V-I-S model is based on a simplification of the large diversity of urban land cover types in three general categories: vegetation, impervious surfaces and soil. These categories were obtained by processing Landsat-5 TM and Landsat-8 OLI images. First, we applied standard radiometric calibration and co-registration methods to all datasets. Second, using a linear spectral unmixing algorithm we performed a soft classification of urban land cover types (end members): trees, shrubs, herbaceous plants, soils, buildings, roads and water bodies. All end members were validated using a combination of photointerpretation on high-resolution images (~1 m) and field data collection (only for 2015). In each pixel we used the resulting probability scores, logically grouped, to obtain final values for each V-I-S component. Third, we used statistical clustering of V-I-S values to create a set of eight pixel groups, which we interpreted as USTs and mapped them for each date. The overall accuracy for V-I-S components in 1985 and 2015 were 78% and 82%, respectively, and errors did not exhibit any spatial correlation. The main sources of differentiation between USTs were the trade-off proportions between vegetation and impervious components, whereas soil proportions remained near 5% across the city in both dates. To analyse the change in UST spatial configuration between dates, we used a set of selected landscape metrics and discussed their use as indicators for sustainable urban development. These indicators relate to the dispersion pattern of urban growth, the connectivity of open green space and the complexity in the composition of the UST types within the different sectors of the city. We were able to identify, using the dynamics exhibited by the USTs, three main zones: (1) city centre, where USTs of high-intensity development predominate, (2) eastern high-income areas whose spatial structure is marked by a relatively high urbanisation intensity with a very large proportion of vegetated spaces, and (3) peripheral areas, with significant changes in composition and configuration of USTs, in recent decades, showing high rates of urbanisation, shifting from low-medium to high densities. We concluded that these patterns and their dynamics are mainly determined by the spatial socio-economic stratification of the population.

[Evolution of hospital concept in Italy].

PubMed

Grosso, G; Contarino, F; Biondi, M; Mistretta, A

2009-01-01

Hospital building trade was born before the origin of Healthcare System and followed the complex development of healthcare during all the past years to present day. At the beginning of 700's, when infective pathology was predominant and hygienic conditions was parameter of quality, pavilions structure took place. These hospitals required wide land to be built on, with a high surface area to volume ratio and a horizontal development. There were about 1200-1500 sleeping accommodations in large rooms (ward) where patients were split up. The typical pavilions structure were used until half 900's when it was replaced with a new concept of building trade, the mono-polibloc. They were buildings with vertical development that minimized horizontal distances and operating costs. Every floor has confinement and service rooms and represent a single and autonomous operating unit. Nowadays hospitals building trade point to use the flat-tower model that enhance the distinction between confinement area (with a vertical development-monobloc) and diagnosis, care and services area (with a horizontal development-flat). The challenge we willface in the future is to convert healthcare buildings to other uses like trading centres and services areas, to improve structures' flexibility, to better include them in the context of the urban and natural setting.

A disadvantaged advantage in walkability: findings from socioeconomic and geographical analysis of national built environment data in the United States.

PubMed

King, Katherine E; Clarke, Philippa J

2015-01-01

Urban form-the structure of the built environment-can influence physical activity, yet little is known about how walkable design differs according to neighborhood sociodemographic composition. We studied how walkable urban form varies by neighborhood sociodemographic composition, region, and urbanicity across the United States. Using linear regression models and 2000-2001 US Census data, we investigated the relationship between 5 neighborhood census characteristics (income, education, racial/ethnic composition, age distribution, and sex) and 5 walkability indicators in almost 65,000 census tracts in 48 states and the District of Columbia. Data on the built environment were obtained from the RAND Corporation's (Santa Monica, California) Center for Population Health and Health Disparities (median block length, street segment, and node density) and the US Geological Survey's National Land Cover Database (proportion open space and proportion highly developed). Disadvantaged neighborhoods and those with more educated residents were more walkable (i.e., shorter block length, greater street node density, more developed land use, and higher density of street segments). However, tracts with a higher proportion of children and older adults were less walkable (fewer street nodes and lower density of street segments), after adjustment for region and level of urbanicity. Research and policy on the walkability-health link should give nuanced attention to the gap between persons living in walkable areas and those for whom walkability has the most to offer. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Improvement of urban water environment of Kaohsiung City, Taiwan, by ecotechnology.

PubMed

Yang, Lei

2012-01-01

Kaohsiung City is the second largest city in Taiwan and suffers from serious floods during the wet season, but it also badly needs water during the dry season. As economic development advances and pollutants increase, water pollution and shortage of water resources become issues of concern for local people in Kaohsiung. A project has been proposed by the city government and executed by the authors to establish a system of sustainable water management in urban areas. In this system, the Caogong Canals, irrigation channels which were established 170 years ago during the Ching Dynasty of China and are still used today for irrigation, were renovated to bring stable and clean water to the urban areas. It is planned to pump clean water into the canal from a river near the city. In this project, 12 constructed wetland systems, functioning as wetland parks, stormwater storage tanks or eco-detention ponds, were built in the city, and the Caogong Canals are planned to connect all these urban constructed wetlands in the second stage of the project.

Potential Climate Change Impacts on the Built Environment in the United States and Implications for Sustainability

NASA Astrophysics Data System (ADS)

Quattrochi, D.

2012-12-01

The built environment consists of components that have been made by humans at a range of scales from small (e.g., houses, shopping malls) to large (e.g., transportation networks) to highly modified landscapes such as cities. The impacts of climate change on the built environment, therefore, may have a multitude of effects on humans and the land. The impact of climate change may be exacerbated by the interaction of different events that singly may be minor, but together may have a synergistic set of impacts that are significant. Also, there may be feedback mechanisms wherein the built environment, particularly in the form of cities, may affect weather and the climate on local and regional scales. Besides having a host of such interactions, the impacts of climate change on urban areas will likely have thresholds, below which effects are incidental or of mild consequence, but beyond which the effects quickly become major. Hence, a city may be able to cope with prolonged heat waves, but if this is combined with severe drought, the overall result could be significant or even catastrophic, as accelerating demand for energy to cooling taxes water supplies needed both for energy supply and municipal water needs. Moreover, urban areas may be affected by changes in daily and seasonal high or low temperatures or precipitation, which may have a much more prolonged impact than the direct effect of these events. Thus, the cumulative impacts of multiple events may be more severe than those of any single event. Primary hazards include sea level rise and coastal storms, heat waves, intense precipitation, drought, extreme wind events, urban heat islands, and secondary air pollutants, and cold air events including frozen precipitation. Indicators need to be developed to provide a consistent, objective, and transparent overview of major variations in climate impacts, vulnerabilities, adaptation, and mitigation activities. Overall, indicators of climate change on the built environment should: 1) provide meaningful, authoritative climate-relevant measures about the status, rates, and trends of key physical, ecological, and societal variables and values to inform decisions on management, research, and education at regional to national scales; 2) identify climate-related conditions and impacts to help develop effective mitigation and adaptation measures and reduce costs of management; and 3) document and communicate the climate-driven dynamic nature and condition of Earth's systems and societies, and provide a coordinated. This presentation will provide an overview of possible climate impacts on the built environment. Also, given that spatial analysis and remote sensing techniques will be of paramount importance in assessing these impacts and in preparing adaptation strategies, the presentation will provide examples of how these techniques can be used to identify potential impacts of climate change on the built environment.

Development of a smart flood warning system in urban areas: A case study of Huwei area in Taiwan

NASA Astrophysics Data System (ADS)

Yang, Sheng-Chi; Hsu, Hao-Ming; Kao, Hong-Ming

2016-04-01

In this study, we developed a smart flood warning system to clearly understand flood propagations in urban areas. The science and technology park of Huwei, located in the southwest of Taiwan, was selected as a study area. It was designated to be an important urban area of optoelectronics and biotechnology. The region has an area about 1 km2 with approximately 1 km in both length and width. The discrepancy between the highest and lowest elevations is 6.3 m and its elevation decreases along the northeast to the southwest. It is an isolated urban drainage area due to its urban construction plan. The storm sewer system in this region includes three major networks that collect the runoff and drain to the detention pond where is located in the southwest corner of the region. The proposed smart flood warning system combines three important parts, i.e. the physical world, the cyber-physical interface, and the cyber space, to identify how the flood affects urban areas from now until the next three hours. In the physical world, when a rainfall event occurs, monitoring sensors (e.g. rainfall gauges and water level gauges built in the sewer system and ground surface), which are established in several essential locations of the study area, collect in situ hydrological data and then these data being transported to the cyber-physical interface. The cyber-physical interface is a data preprocess space that includes data analysis, quality control and assurance, and data integration and standardization to produce the validated data. In the cyber space, it has missions to receive the validated data from the cyber-physical interface and to run the time machine that has flood analyses of data mining, inundation scenarios simulation, risk and economic assessments, and so on, based on the validated data. After running the time machine, it offers the analyzed results related to flooding planning, mitigation, response, and recovery. According to the analyzed results, the decision supporting system, therefore, can publish warning information in urban areas at the right time. Keywords: flood warning system, flood mitigation, inundation.

Freight transportation and the potential for invasions of exotic insects in urban and periurban forests of the United States.

PubMed

Colunga-Garcia, Manuel; Haack, Robert A; Adelaja, Adesoji O

2009-02-01

Freight transportation is an important pathway for the introduction and dissemination of exotic forest insects (EFI). Identifying the final destination of imports is critical in determining the likelihood of EFI establishment. We analyzed the use of regional freight transport information to characterize risk of urban and periurban areas to EFI introductions. Specific objectives were to 1) approximate the final distribution of selected imports among urban areas of the United States, 2) characterize the final distribution of imports in terms of their spatial aggregation and dominant world region of origin, and 3) assess the effect of the final distribution of imports on the level of risk to urban and periurban forests from EFI. Freight pattern analyses were conducted for three categories of imports whose products or packaging materials are associated with EFI: wood products, nonmetallic mineral products, and machinery. The final distribution of wood products was the most evenly distributed of the three selected imports, whereas machinery was most spatially concentrated. We found that the type of import and the world region of origin greatly influence the final distribution of imported products. Risk assessment models were built based on the amount of forestland and imports for each urban area The model indicated that 84-88% of the imported tonnage went to only 4-6% of the urban areas in the contiguous United States. We concluded that freight movement information is critical for proper risk assessment of EFI. Implications of our findings and future research needs are discussed.

Preserving ecosystem services in urban regions: challenges for planning and best practice examples from Switzerland.

PubMed

Tobias, Silvia

2013-04-01

This article presents a literature review that explores the challenges for planning in urban regions in connection with the preservation of ecosystem services. It further presents some best practice examples for meeting these challenges. The demand for the provision of ecosystem services within urban regions changed during the transition from a largely agrarian society to an industrial society and, most recently, to a service society. Although in the past, provisioning services such as food production or the provision of raw material were decisive for urban development, today cultural services, e.g., clear views or nearby recreation areas, have become increasingly important. According to the literature, soil sealing is the greatest threat urbanization poses toward ecosystem services, as it compromises all of them. Spatially extensive cities with a high building density particularly inhibit regulating services like the regulation of temperature or water surface runoff. Conversely, scattered settlement patterns may lead to very small remnants of open space that cannot reasonably serve as natural habitat, agricultural land, or recreation area. The challenges for planning in urban regions are: 1) specifying regulations that define outer limits to the development of each settlement unit, 2) comprehensive planning with focal points for development, and limiting access and development at other places, and 3) compensating for new soil sealing by restoring nearby sealed areas. The article presents 3 best-practice examples that support these principles: designating areas with a particular soil quality that should not be built over, offering incentives for corporate planning in urban regions, and restoring a country road in connection with a motorway construction. Copyright © 2013 SETAC.

Preserving Ecosystem Services in Urban Regions: Challenges for Planning and Best Practice Examples from Switzerland

PubMed Central

Tobias, Silvia

2013-01-01

This article presents a literature review that explores the challenges for planning in urban regions in connection with the preservation of ecosystem services. It further presents some best practice examples for meeting these challenges. The demand for the provision of ecosystem services within urban regions changed during the transition from a largely agrarian society to an industrial society and, most recently, to a service society. Although in the past, provisioning services such as food production or the provision of raw material were decisive for urban development, today cultural services, e.g., clear views or nearby recreation areas, have become increasingly important. According to the literature, soil sealing is the greatest threat urbanization poses toward ecosystem services, as it compromises all of them. Spatially extensive cities with a high building density particularly inhibit regulating services like the regulation of temperature or water surface runoff. Conversely, scattered settlement patterns may lead to very small remnants of open space that cannot reasonably serve as natural habitat, agricultural land, or recreation area. The challenges for planning in urban regions are: 1) specifying regulations that define outer limits to the development of each settlement unit, 2) comprehensive planning with focal points for development, and limiting access and development at other places, and 3) compensating for new soil sealing by restoring nearby sealed areas. The article presents 3 best-practice examples that support these principles: designating areas with a particular soil quality that should not be built over, offering incentives for corporate planning in urban regions, and restoring a country road in connection with a motorway construction. Integr Environ Assess Manag 2013; 9: 243–251. © 2013 SETAC PMID:23307283

Assessing summertime urban air conditioning consumption in a semiarid environment

NASA Astrophysics Data System (ADS)

Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Wang, M.; Svoma, B. M.

2013-09-01

Evaluation of built environment energy demand is necessary in light of global projections of urban expansion. Of particular concern are rapidly expanding urban areas in environments where consumption requirements for cooling are excessive. Here, we simulate urban air conditioning (AC) electric consumption for several extreme heat events during summertime over a semiarid metropolitan area with the Weather Research and Forecasting (WRF) model coupled to a multilayer building energy scheme. Observed total load values obtained from an electric utility company were split into two parts, one linked to meteorology (i.e., AC consumption) which was compared to WRF simulations, and another to human behavior. WRF-simulated non-dimensional AC consumption profiles compared favorably to diurnal observations in terms of both amplitude and timing. The hourly ratio of AC to total electricity consumption accounted for ˜53% of diurnally averaged total electric demand, ranging from ˜35% during early morning to ˜65% during evening hours. Our work highlights the importance of modeling AC electricity consumption and its role for the sustainable planning of future urban energy needs. Finally, the methodology presented in this article establishes a new energy consumption-modeling framework that can be applied to any urban environment where the use of AC systems is prevalent.

The perceived and built environment surrounding urban schools and physical activity among adolescent girls.

PubMed

Hager, Erin R; Witherspoon, Dawn O; Gormley, Candice; Latta, Laura W; Pepper, M Reese; Black, Maureen M

2013-02-01

Neighborhood perceived/built environment and physical activity (PA) associations have been examined for adolescents around homes, but not surrounding schools. The purpose of this paper is to examine if positive perceptions/built environment in neighborhoods surrounding schools predict PA among low-income, urban adolescent girls. Measures include: minutes in moderate-vigorous PA (MVPA, ankle accelerometry), perceptions of the school environment (questionnaire), built environment (neighborhood audit). Analyses include multi-level models. Two hundred twenty-four sixth and seventh grade girls [mean(sd) age = 12.1(0.7) years] from 12 schools serving low-income, primarily African American communities; mean MVPA 35.4 min (mean days assessed = 5.8). Girls in schools with more positive perceptions of the neighborhood environment surrounding the school were less active (β = 7.2, p = 0.043). Having "places to go within walking distance" (perceptions) and number of food stores near school (built environment) positively relate to MVPA (β = 5.5, p = 0.042 and β = 0.59, p = 0.047). Among neighborhoods surrounding urban schools, positive perceptions do not predict PA; accessibility, via both perceived and built environment, support PA.

Review of Strategies for Thermal Efficiency in Landscape Planning of Cities for Conservation of Energy and Enhanced Climatic Resilience to Urban Warming

NASA Astrophysics Data System (ADS)

Imam, Aabshar U. K.; Banerjee, Uttam Kumar

2017-09-01

Thermal discomfort, increased energy consumption, and heat related stress are some of the most prominent consequences of urban warming. Instances of heat related deaths have been reported; the elderly and the poor remain especially vulnerable. Urban greening has often been cited as an economically efficient method for inducing ambient cooling. Consequently, increased impetus is given to provision of public green spaces. However, a general increase in urban green cover especially in the form of parks and green spaces may be inadequate to achieve desired results. This article serves to highlight the thermal heterogeneity of landcape elements and stresses on the need for strategic shade provision. The originality of this study lies in the fact that it provides a comparative review of energy conservation potential of public and private green spaces. It is found that large parks may not have substantial cooling effect on the indoor built environment. Moreover, people tend to spend more time indoors than outdoors. Thus the need for greening of private areas has become an undeniable climatic necessity. The potential of shade trees, green walls, and roof gardens for cooling of built environment are discussed with quantitative evidences of their thermal and economic benefits. Parameters incurring cost expenditure and weaknesses of the greening strategies are enumerated for enabling prudent selection/implementation of strategies. Proposals are generated to improve climatic resilience to urban warming and for diligent planning of cities.

Residential greenness and birth outcomes: evaluating the influence of spatially correlated built-environment factors.

PubMed

Hystad, Perry; Davies, Hugh W; Frank, Lawrence; Van Loon, Josh; Gehring, Ulrike; Tamburic, Lillian; Brauer, Michael

2014-10-01

Half the world's population lives in urban areas. It is therefore important to identify characteristics of the built environment that are beneficial to human health. Urban greenness has been associated with improvements in a diverse range of health conditions, including birth outcomes; however, few studies have attempted to distinguish potential effects of greenness from those of other spatially correlated exposures related to the built environment. We aimed to investigate associations between residential greenness and birth outcomes and evaluate the influence of spatially correlated built environment factors on these associations. We examined associations between residential greenness [measured using satellite-derived Normalized Difference Vegetation Index (NDVI) within 100 m of study participants' homes] and birth outcomes in a cohort of 64,705 singleton births (from 1999-2002) in Vancouver, British Columbia, Canada. We also evaluated associations after adjusting for spatially correlated built environmental factors that may influence birth outcomes, including exposure to air pollution and noise, neighborhood walkability, and distance to the nearest park. An interquartile increase in greenness (0.1 in residential NDVI) was associated with higher term birth weight (20.6 g; 95% CI: 16.5, 24.7) and decreases in the likelihood of small for gestational age, very preterm (< 30 weeks), and moderately preterm (30-36 weeks) birth. Associations were robust to adjustment for air pollution and noise exposures, neighborhood walkability, and park proximity. Increased residential greenness was associated with beneficial birth outcomes in this population-based cohort. These associations did not change after adjusting for other spatially correlated built environment factors, suggesting that alternative pathways (e.g., psychosocial and psychological mechanisms) may underlie associations between residential greenness and birth outcomes.

Multi-layer planting as a strategy of greening the transitional space in high-rise buildings: A review

NASA Astrophysics Data System (ADS)

Prihatmanti, Rani; Taib, Nooriati

2018-03-01

The issues regarding the rapid development in the urban have resulted in the increasing number of infrastructure built, including the high-rise buildings to accommodate the urban dwellers. Lack of greeneries due to the land limitation in the urban area has increased the surface radiation as well as the air temperature that leads to the Urban Heat Island (UHI) phenomena. Where urban land is limited, growing plants vertically could be a solution. Plants, which are widely known as one of the sustainability elements in the built environment could be integrated in building as a part of urban faming by growing edible plant species. This is also to address the food security issue in the urban as well as high-density cities. Since space is limited, the function of transitional space could be optimized for the green space. This paper explores the strategy of greening transitional space in the high-rise setting. To give a maximum impact in a limited space, multi-layer planting concept could be introduced. This concept is believed that multiple layers of plants could modify the microclimate, as well as the radiation to the building, compare to single layer plant. In addition to that, the method selected also determines the efficacy of the vertical greeneries. However, there are many other limitations related to the multi-layer planting method if installed in a transitional space that needs to be further studied. Despite its limitations, the application of vertical greeneries with multi-layer planting concept could be a promising solution for greening the limited space as well as improving the thermal comfort in the high-rise building.

Changing Bee and Hoverfly Pollinator Assemblages along an Urban-Rural Gradient

PubMed Central

Bates, Adam J.; Sadler, Jon P.; Fairbrass, Alison J.; Falk, Steven J.; Hale, James D.; Matthews, Tom J.

2011-01-01

Background The potential for reduced pollination ecosystem service due to global declines of bees and other pollinators is cause for considerable concern. Habitat degradation, destruction and fragmentation due to agricultural intensification have historically been the main causes of this pollinator decline. However, despite increasing and accelerating levels of global urbanization, very little research has investigated the effects of urbanization on pollinator assemblages. We assessed changes in the diversity, abundance and species composition of bee and hoverfly pollinator assemblages in urban, suburban, and rural sites across a UK city. Methodology/Principal Findings Bees and hoverflies were trapped and netted at 24 sites of similar habitat character (churchyards and cemeteries) that varied in position along a gradient of urbanization. Local habitat quality (altitude, shelter from wind, diversity and abundance of flowers), and the broader-scale degree of urbanization (e.g. percentage of built landscape and gardens within 100 m, 250 m, 500 m, 1 km, and 2.5 km of the site) were assessed for each study site. The diversity and abundance of pollinators were both significantly negatively associated with higher levels of urbanization. Assemblage composition changed along the urbanization gradient with some species positively associated with urban and suburban land-use, but more species negatively so. Pollinator assemblages were positively affected by good site habitat quality, in particular the availability of flowering plants. Conclusions/Significance Our results show that urban areas can support diverse pollinator assemblages, but that this capacity is strongly affected by local habitat quality. Nonetheless, in both urban and suburban areas of the city the assemblages had fewer individuals and lower diversity than similar rural habitats. The unique development histories of different urban areas, and the difficulty of assessing mobile pollinator assemblages in just part of their range, mean that complementary studies in different cities and urban habitats are required to discover if these findings are more widely applicable. PMID:21858128

A Disadvantaged Advantage in Walkability: Findings from Socioeconomic and Geographic Analysis of National Built Environment Data in the United States.

EPA Science Inventory

Urban form-the structure of the built environment-can influence physical activity, yet little is known about how walkable design differs according to neighborhood sociodemographic composition. We studied how walkable urban form varies by neighborhood sociodemographic composition,...

Inverse association between urbanicity and treatment resistance in schizophrenia.

PubMed

Wimberley, Theresa; Pedersen, Carsten B; MacCabe, James H; Støvring, Henrik; Astrup, Aske; Sørensen, Holger J; Horsdal, Henriette T; Mortensen, Preben B; Gasse, Christiane

2016-07-01

Living in a larger city is associated with increased risk of schizophrenia; and world-wide, consistent evidence shows that the higher the degree of urbanicity the higher the risk of schizophrenia. However, the association between urbanicity and treatment-resistant schizophrenia (TRS) as a more severe form of schizophrenia or separate entity of schizophrenia has not been fully explored yet. We aimed to investigate the association between urbanicity and incidence of TRS. A large Danish population-based cohort of all individuals with a first schizophrenia diagnosis after 1996 was followed until 2013 applying survival analysis techniques. TRS was assessed using a treatment-based proxy, defined as the earliest observed instance of either clozapine initiation or hospital admission due to schizophrenia after having received two prior antipsychotic monotherapy trials of adequate duration. Among the 13,349 schizophrenia patients, 17.3% experienced TRS during follow-up (median follow-up: 7years, inter-quartile range: 3-12years). The 5-year risk of TRS ranged from 10.5% in the capital area to 17.6% in the rural areas. Compared with individuals with schizophrenia residing in the capital area, hazard ratios were 1.44 (1.31-1.59) for provincial areas and 1.60 (1.43-1.79) for rural areas. Higher rates of TRS were found in less urbanized areas. The different direction of urban-rural differences regarding TRS and schizophrenia risk may indicate urban-rural systematic differences in treatment practices, or different urban-rural aetiologic types of schizophrenia. Copyright © 2016 Elsevier B.V. All rights reserved.

Using phytotechnologies to remediate brownfields, landfills, and other urban areas

Treesearch

R.S. Zalesny Jr.; Jill Zalesny

2010-01-01

Urban areas requiring remedial work has prompted the use of phytotechnologies to improve water quality, soil health, and biodiversity, as well as to achieve sustainable social and economic goals. Phytotechnologies directly use plants to clean up contaminated groundwater, soil, and sediment.

Built Expansion and Global Climate Change Drive Projected Urban Heat: Relative Magnitudes, Interactions, and Mitigation

NASA Astrophysics Data System (ADS)

Krayenhoff, E. S.; Georgescu, M.; Moustaoui, M.

2016-12-01

Surface climates are projected to warm due to global climate change over the course of the 21st century, and demographic projections suggest urban areas in the United States will continue to expand and develop, with associated local climate outcomes. Interactions between these two drivers of urban heat have not been robustly quantified to date. Here, simulations with the Weather Research and Forecasting model (coupled to a Single-Layer Urban Canopy Model) are performed at 20 km resolution over the continental U.S. for two 10-year periods: contemporary (2000-2009) and end-of-century (2090-2099). Present and end of century urban land use are derived from the Environmental Protection Agency's Integrated Climate and Land-Use Scenarios. Modelled effects on urban climates are evaluated regionally. Sensitivity to climate projection (Community Climate System Model 4.0, RCP 4.5 vs. RCP 8.5) and associated urban development scenarios are assessed. Effects on near-surface urban air temperature of RCP8.5 climate change are greater than those attributable to the corresponding urban development in many regions. Interaction effects vary by region, and while of lesser magnitude, are not negligible. Moreover, urban development and its interactions with RCP8.5 climate change modify the distribution of convective precipitation over the eastern US. Interaction effects result from the different meteorological effects of urban areas under current and future climate. Finally, the potential for design implementations such as green roofs and high albedo roofs to offset the projected warming is considered. Impacts of these implementations on precipitation are also assessed.

Factors influencing spatial pattern in tropical forest clearance and stand age: Implications for carbon storage and species diversity.

Treesearch

E. H. Helmer; Thomas J. Brandeis; Ariel E. Lugo; Todd Kennaway

2008-01-01

Little is known about the tropical forests that undergo clearing as urban/built-up and other developed lands spread. This study uses remote sensing-based maps of Puerto Rico, multinomial logit models and forest inventory data to explain patterns of forest age and the age of forests cleared for land development and assess their implications for forest carbon storage and...

Relations between nature-based solutions of green-blue area accessibility and socio-economic-ethnic patterns in the urban Stockholm region

NASA Astrophysics Data System (ADS)

Goldenberg, Romain; Kalantari, Zahra; Destouni, Georgia

2017-04-01

More than half of the world's population lives in cities, a proportion expected to increase to two thirds by 2050 (United Nations (UN), 2015). In this study, we investigate the spatial relationships that may exist between income and/or nationality homogeneity/heterogeneity levels of urban populations and their accessibility to local green-blue areas as possible nature-based solutions for sustainable urban design. For this investigation, we consider as a concrete case study the urban region of Stockholm, Sweden, for which we compile and use available land-cover and vegetation density data (the latter in terms of Normalised Difference Vegetation Index, NDVI) in order to identify and assess the spatial distributions of various green-blue area types and aspects. We further combine this data with spatial distribution data for population density, income and nationality, as well as with road-network data for assessing population travel times to nearby green-blue areas within the region. The present study results converge with those of other recent studies in showing large socio-economic-ethnic segregation in the Stockholm region. Moreover, the present data combination and analysis also show large spatial differences in and important socio-economic-ethnic correlations with accessibility to local green areas and nearby water bodies. Specifically, population income and share of Swedish nationals are well correlated in this region, with increases in both of these variables implying greater possibility to choose where to live within the region. The living choices of richer and more homogeneous (primarily Swedish) population parts are then found to be areas with greater local vegetation density (local green areas as identified by high-resolution NDVI data) and greater area extent of nearby water bodies (blue areas). For comparison, no such correlation is found between increased income or Swedish nationality homogeneity and accessibility to nearby forest areas (overall green area extent) or built facilities for recreation and sports. The found living choice correlations point at the importance of green-blue area parts as possible nature-based solutions in urban design and planning, with potential to improve wellbeing and social sustainability for the whole urban population and not just its rich component.

The Urban Environmental Monitoring/100 Cities Project: Legacy of the First Phase and Next Steps

NASA Technical Reports Server (NTRS)

Stefanov, William L.; Wentz, Elizabeth A.; Brazel, Anthony; Netzband, Maik; Moeller, Matthias

2009-01-01

The Urban Environmental Monitoring (UEM) project, now known as the 100 Cities Project, at Arizona State University (ASU) is a baseline effort to collect and analyze remotely sensed data for 100 urban centers worldwide. Our overarching goal is to use remote sensing technology to better understand the consequences of rapid urbanization through advanced biophysical measurements, classification methods, and modeling, which can then be used to inform public policy and planning. Urbanization represents one of the most significant alterations that humankind has made to the surface of the earth. In the early 20th century, there were less than 20 cities in the world with populations exceeding 1 million; today, there are more than 400. The consequences of urbanization include the transformation of land surfaces from undisturbed natural environments to land that supports different forms of human activity, including agriculture, residential, commercial, industrial, and infrastructure such as roads and other types of transportation. Each of these land transformations has impacted, to varying degrees, the local climatology, hydrology, geology, and biota that predate human settlement. It is essential that we document, to the best of our ability, the nature of land transformations and the consequences to the existing environment. The focus in the UEM project since its inception has been on rapid urbanization. Rapid urbanization is occurring in hundreds of cities worldwide as population increases and people migrate from rural communities to urban centers in search of employment and a better quality of life. The unintended consequences of rapid urbanization have the potential to cause serious harm to the environment, to human life, and to the resulting built environment because rapid development constrains and rushes decision making. Such rapid decision making can result in poor planning, ineffective policies, and decisions that harm the environment and the quality of human life. Slower, more thought-out, decision making could result in more favorable outcomes. The harm to the environment includes poor air quality, soil erosion, polluted rivers and aquifers, and loss of wildlife habitat. Human life is then threatened because of increased potential for disease spreading, human conflict, environmental hazards, and diminished quality of life. The built environment is potentially threatened when cities are built in areas that can be impacted by events such as hurricanes, tsunamis, earthquakes, fires, and landslides. Our goals include assessing the threat of such events on cities and the people living there.

A study on the relationship between carbon budget and ecosystem service in urban areas according to urbanization

NASA Astrophysics Data System (ADS)

Lee, S. J.; Lee, W. K.

2017-12-01

The study on the analysis of carbon storage capacity of urban green spaces with increasing urban forest. Modern cities have experienced rapid economic development since Industrial Revolution in the 18th century. The rapid economic growth caused an exponential concentration of population to the cities and decrease of green spaces due to the conversion of forest and agricultural lands to build-up areas with rapid urbanization. As green areas including forests, grasslands, and wetlands provide diverse economic, environmental, and cultural benefits, the decrease of green areas might be a huge loss. Also, the process of urbanization caused pressure on the urban environment more than its natural capacity, which accelerates global climate change. This study tries to see the relations between carbon budget and ecosystem services according to the urbanization. For calculating carbon dynamics, this study used VISIT(Vegetation Integrated Simulator for trace gases) model. And the value that ecosystem provides is explained with the concept of ecosystem service and calculated by InVEST model. Study sites are urban and peri-urban areas in Northeast Asia. From the result of the study, the effect of the urbanization can be understood in regard to carbon storage and ecosystem services.

Violent crime in San Antonio, Texas: an application of spatial epidemiological methods.

PubMed

Sparks, Corey S

2011-12-01

Violent crimes are rarely considered a public health problem or investigated using epidemiological methods. But patterns of violent crime and other health conditions are often affected by similar characteristics of the built environment. In this paper, methods and perspectives from spatial epidemiology are used in an analysis of violent crimes in San Antonio, TX. Bayesian statistical methods are used to examine the contextual influence of several aspects of the built environment. Additionally, spatial regression models using Bayesian model specifications are used to examine spatial patterns of violent crime risk. Results indicate that the determinants of violent crime depend on the model specification, but are primarily related to the built environment and neighborhood socioeconomic conditions. Results are discussed within the context of a rapidly growing urban area with a diverse population. Copyright © 2011 Elsevier Ltd. All rights reserved.

Engineering geological mapping in Wallonia (Belgium) : present state and recent computerized approach

NASA Astrophysics Data System (ADS)

Delvoie, S.; Radu, J.-P.; Ruthy, I.; Charlier, R.

2012-04-01

An engineering geological map can be defined as a geological map with a generalized representation of all the components of a geological environment which are strongly required for spatial planning, design, construction and maintenance of civil engineering buildings. In Wallonia (Belgium) 24 engineering geological maps have been developed between the 70s and the 90s at 1/5,000 or 1/10,000 scale covering some areas of the most industrialized and urbanized cities (Liège, Charleroi and Mons). They were based on soil and subsoil data point (boring, drilling, penetration test, geophysical test, outcrop…). Some displayed data present the depth (with isoheights) or the thickness (with isopachs) of the different subsoil layers up to about 50 m depth. Information about geomechanical properties of each subsoil layer, useful for engineers and urban planners, is also synthesized. However, these maps were built up only on paper and progressively needed to be updated with new soil and subsoil data. The Public Service of Wallonia and the University of Liège have recently initiated a study to evaluate the feasibility to develop engineering geological mapping with a computerized approach. Numerous and various data (about soil and subsoil) are stored into a georelational database (the geotechnical database - using Access, Microsoft®). All the data are geographically referenced. The database is linked to a GIS project (using ArcGIS, ESRI®). Both the database and GIS project consist of a powerful tool for spatial data management and analysis. This approach involves a methodology using interpolation methods to update the previous maps and to extent the coverage to new areas. The location (x, y, z) of each subsoil layer is then computed from data point. The geomechanical data of these layers are synthesized in an explanatory booklet joined to maps.

Fast food restaurant locations according to socioeconomic disadvantage, urban-regional locality, and schools within Victoria, Australia.

PubMed

Thornton, Lukar E; Lamb, Karen E; Ball, Kylie

2016-12-01

Features of the built environment provide opportunities to engage in both healthy and unhealthy behaviours. Access to a high number of fast food restaurants may encourage greater consumption of fast food products. The distribution of fast food restaurants at a state-level has not previously been reported in Australia. Using the location of 537 fast food restaurants from four major chains (McDonald׳s, KFC, Hungry Jacks, and Red Rooster), this study examined fast food restaurant locations across the state of Victoria relative to area-level disadvantage, urban-regional locality (classified as Major Cities, Inner Regional, or Outer Regional), and around schools. Findings revealed greater locational access to fast food restaurants in more socioeconomically disadvantaged areas (compared to areas with lower levels of disadvantage), nearby to secondary schools (compared to primary schools), and nearby to primary and secondary schools within the most disadvantaged areas of the major city region (compared to primary and secondary schools in areas with lower levels of disadvantage). Adjusted models showed no significant difference in location according to urban-regional locality. Knowledge of the distribution of fast food restaurants in Australia will assist local authorities to target potential policy mechanisms, such as planning regulations, where they are most needed.

Roads as sources of heavy metals in urban areas. The Covões Catchment experiment, Coimbra, Portugal

NASA Astrophysics Data System (ADS)

Ferreira, António J. D.; Soares, Daniel; Ferreira, Carla S. S.; Walsh, Rory P. D.

2015-04-01

Cities are the home to 50% of the human specie [UN 2011 Ramalho & Hobbs 2012], whose wellbeing, way of life and exposure to hazard situations are directly related to the built environment. Cities are often seen as ecological systems just a short step away from collapse [Newman 2006]. Being a human construction, cities disrupt the natural cycles and the patterns of temporal and spatial distribution of environmental and ecological processes. Urbanization produces ruptures in biota, water, energy and nutrients connectivity that can lead to an enhanced exposure to disruptive events that hamper the wellbeing and the resilience of urban communities in a global change context. A major issue in what concerns the threats to human and ecosystem health in urban areas is the presence of heavy metals, and the related processes that govern their source, transport and fade r uptake by the vegetation. In this work, we present an analysis of heavy metal sources and transport processes at various types of roads within the Ribeira dos Covões peri-urban experimental catchment in central Portugal. The surveyed heavy metals (Cadmium, Lead, Coper, and Zinc) show significant differences as a result of the type of rainfall event, the length of the antecedent dry spell, the traffic volume and the heavy metals sources. For some locations, namely for the roads with heavy traffic volume, the heavy metal concentrations exceed the limits established by law, which has severe implications to the downstream ecosystems and to the possible use of the water from roads to close the resources loop in urban areas, namely in what concerns their use to water the urban green infrastructure or to irrigate the urban agriculture fields.

Wind-Induced Air-Flow Patterns in an Urban Setting: Observations and Numerical Modeling

NASA Astrophysics Data System (ADS)

Sattar, Ahmed M. A.; Elhakeem, Mohamed; Gerges, Bishoy N.; Gharabaghi, Bahram; Gultepe, Ismail

2018-04-01

City planning can have a significant effect on wind flow velocity patterns and thus natural ventilation. Buildings with different heights are roughness elements that can affect the near- and far-field wind flow velocity. This paper aims at investigating the impact of an increase in building height on the nearby velocity fields. A prototype urban setting of buildings with two different heights (25 and 62.5 cm) is built up and placed in a wind tunnel. Wind flow velocity around the buildings is mapped at different heights. Wind tunnel measurements are used to validate a 3D-numerical Reynolds averaged Naviers-Stokes model. The validated model is further used to calculate the wind flow velocity patterns for cases with different building heights. It was found that increasing the height of some buildings in an urban setting can lead to the formation of large horseshoe vortices and eddies around building corners. A separation area is formed at the leeward side of the building, and the recirculation of air behind the building leads to the formation of slow rotation vortices. The opposite effect is observed in the wake (cavity) region of the buildings, where both the cavity length and width are significantly reduced, and this resulted in a pronounced increase in the wind flow velocity. A significant increase in the wind flow velocity in the wake region of tall buildings with a value of up to 30% is observed. The spatially averaged velocities around short buildings also increased by 25% compared to those around buildings with different heights. The increase in the height of some buildings is found to have a positive effect on the wind ventilation at the pedestrian level.

Methodological proceedings to evaluate the physical accessibility in urban historic sites.

PubMed

Ribeiro, Gabriela Sousa; Martins, Laura Bezerra; Monteiro, Circe Maria Gama

2012-01-01

Historic urban sites are set by cultural and social diversities, generating multiple activities and use and access to these sites should be available to all people including those with disabilities. Taking into consideration that using the same methodology that was used in different historic sites researches with positive results facilitates replication, we aimed to develop methodological procedures that identify conditions of physical accessibility in open public spaces and access to public buildings in historic urban sites to support proposals about design requirements for improvements to the problems diagnosed and control inadequacies of the physical environment. The study methods and techniques from different areas of knowledge culminated in a proposal built with an emphasis on user participation that could be applied with low cost and in relatively short period of time.

Is Climate Chang Responsible to Recent Urban Flooding in Devloping Cities in Africa? A Case study of Addis Ababa City, Ethiopia

NASA Astrophysics Data System (ADS)

Moges, Semu; Raschid-Sally, Liqa; Gebremichael, Mekonnen

2013-04-01

Cities in Africa show extraordinary expansion of the built environment and imperviousness of the surface condition. Addis Ababa is a case in point, where over the priod of 1984 to 2002, the city asphalted area has increased from 4.72 sq.km (1984) to 27.7 sq.km (2002). Similarly the paved area has expanded five fold from the original 11.1 sq.km, whilst the built environment expanded from 60.1 to 212.7 sq.km. Using hydrological modeling, we demonstrated due to the surface condition change, runoff generation potential has shown significant increase from 28% (in 1984) to 45% (in 2002), showing over 60% change in the runoff volume. The changing condition of the surface is increasing anabtedly, worsening the flooding condition. Similarly, climate change study shows likely increase of precipitation in and around Addis Ababa by about 13 to 17% and comparative increase in flooding. Unlike many cities in Europe, cities in developing countries are confronted with impact emanating from climate change as well as surface condition change. The impact of flooding caused due to the expansion of built environment is found to be more significant in the short term that the climate change, however, the climate change may dominate the long term future of flooding pattern as cities mature towards 2050. Therefore, It is important to view the impacts expansion of built environment and climate change in tandem in future time horizon since the dominance of the impact is different in different temporal scale. In the case of Addis Ababa, we strongly present the following four suggesions: i) the city adminstration re-estabilish the abandoned flood and drainage department of the city as the main flood regulatory and management body working in tandem with Addis Ababa Roads Authority, Water Supply and Sanitation Authority and Urban Planning Authority; ii) The old design guidlines for palnning and design of urban drainage system is not working any more (assumed stationarity condition), we suggest the planning and design criteria of urban drainage systems be immediately revised and incorporated to reflect the new reality of hydrologial non-stationarity; iii) for Addis Ababa City to be Resilient, we suggest implementation of 'Best Managemnt Practice" that incorporates arresting runoff from the source for benefial use, application of runoff treatment practices (open space, infiltration galleries, retardnat ponds, etc) and flood flow control drainage system based on new design criteria, and iv) instituting improved weather forecasting and early warning system.

Impact of regional afforestation on climatic conditions in metropolitan areas: case study of Copenhagen

NASA Astrophysics Data System (ADS)

Stysiak, Aleksander Andrzej; Bergen Jensen, Marina; Mahura, Alexander

2016-04-01

Like most other places, European metropolitan areas will face a range of climate-related challenges over the next decades that may influence the nature of urban life across the continent. Under future urbanization and climate change scenarios the well-being and comfort of the urban population might become progressively compromised. In urban areas, the effects of the warming climate will be accelerated by combination of Urban Heat Island effect (UHI) and extreme heat waves. The land cover composition directly influences atmospheric variability, and can either escalate or downscale the projected changes. Vegetation, forest ecosystems in particular, are anticipated to play an important role in modulating local and regional climatic conditions, and to be vital factor in the process of adapting cities to warming climate. This study investigates the impact of forest and land-cover change on formation and development of temperature regimes in the Copenhagen Metropolitan Area (CPH-MA). Potential to modify the UHI effect in CPH-MA is estimated. Using 2009 meteorological data, and up-to-date 2012 high resolution land-cover data we employed the online integrated meteorology-chemistry/aerosols Enviro-HIRLAM (Environment - High Resolution Limited Area Model) modeling system to simulate air temperature (at 2 meter height) fields for a selected period in July 2009. Employing research tools (such as METGRAF meteorological software and Geographical Information Systems) we then estimated the influence of different afforestation and urbanization scenarios with new forests being located after the Danish national afforestation plan, after proximity to the city center, after dominating wind characteristics, and urbanization taking place as densification of the existing conurbation. This study showed the difference in temperature up to 3.25°C, and the decrease in the spatial extent of temperature fields up to 68%, depending on the selected scenario. Performed simulations demonstrated that well-positioned and well-sized afforestation at the regional scale can significantly affect the spatial distribution, structure and intensity of the temperature field. This study points to vegetation having practical applications in urban and regional planning for modifying local climatic conditions. Keywords: Urban Heat Island, Afforestation, Land cover change, Urban planning, Climate change adaptation, Enviro-HIRLAM

Improving the environment in urban areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamkus, V.V.

1994-12-31

The author discusses the need for improvements to the environment in urban areas, and efforts being made under the direction of the Environmental Protection Agency (EPA) to address these problems. The impact the new Clean Air Act can have on emissions from gasoline powered autos, diesel burning trucks, fixed emission sources ranging from utilities to chemical plants, and consumer products like hair sprays and charcoal starters, will all work together to improve air quality in urban areas. The author also discusses Brownfields Economic Redevelopment Plan efforts being supported by the EPA in a coordinated plan to get municipalities involved inmore » cleaning up areas with pollution, to remove the blight on the urban areas, provide new land for development, and promote additional jobs.« less

Characterizing continuous urban growth using composited time-series Landsat data

NASA Astrophysics Data System (ADS)

Song, X. P.; Sexton, J. O.; Huang, C.; Feng, M.; Channan, S.; Baker, M. E.; Townshend, J. R.

2014-12-01

Impervious surfaces are land cover features through which water cannot penetrate into the soil. As an indicator of urban land use, impervious surface cover (ISC) is disproportionally important to human beings-although covering only 0.5% of the Earth's terrestrial surface, cities support over 50% the Earth's population. The increasing demand for built-up space by a growing urban population has been driving land use change in urban areas worldwide. An increase in ISC can significantly impact the biophysical characteristics of land surface, such as altering the local surface energy balance, or transforming regional hydrological systems. Remotely sensed data is commonly used as the primary data source for extracting impervious surface information for monitoring urban growth, but current studies often lack the sufficient temporal resolution or thematic detail to reveal the long-term, nonlinear development of impervious surfaces over time. In a previous study (Sexton et al. 2013), we created an annual stack of 30-m percent ISC estimates for the Washington DC-Baltimore metropolitan region from 1984 to 2010 by compositing all available Landsat images in the USGS archive. Here we developed a robust time-series method to detect impervious surface change. The method employs a customized logistic function for every pixel to model the continuous process of urban growth. It quantifies the fractional intensity of ISC change at the sub-pixel level and also characterizes the timing and length (in years) of urban development. The new method detects change based on a sequence of observations before, during and after change and thus is highly resistant to random noises. Our results showed that the DC-Baltimore metropolitan region experienced an accelerated growth pathway from the late 1980s to the late 2000s. The majority of urban and sub-urban development occurred at scales finer than the Landsat resolution (30 m), with a region-wide mean intensity of 46% ISC increase. Our study demonstrates the value of the long-term and fine temporal resolution data offered by the Landsat archive, and also highlights the possible limitations of Landsat's spatial resolution in characterizing continuous urban development.

Drivers, trends, and potential impacts of long-term coastal reclamation in China from 1985 to 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian, Bo; Wu, Wenting; Yang, Zhaoqing

Driven by rapid economic development, population growth, and urbanization, China has experienced severe coastal land reclamation over the last decades, which resulted in significant loss of coastal wetland and wildlife habitat, and degradation of marine ecosystems. This study used advanced remote-sensing techniques to analyze the spatial and temporal distributions of coastal reclamation in China and investigated the relationships between coastal land reclamation and coastal economy, population growth, and urbanization. Analysis of long-term Landsat images time series from 1985 to 2010 in 5-year intervals, in combination with remotely sensed image techniques, indicated a sharp increasing trend of land reclamation after 2005,more » which accounted for over 35% of China’s total reclamation during the 25-year period since 1985. High-intensity coastal reclamation in China was mainly driven by the booming economy associated with urbanization and industrial development in the coastal region. Analysis indicated that coastal land reclamation is closely correlated with the GDP per capita in China. Study results of Landsat images showed that 754,697 ha of coastal wetlands have been reclaimed across all coastal provinces and metropolises from 1985 to 2010, at an annual rate of 5.9%. Coastal areas within the three major economic zones (Bohai Bay, Yangtze River Delta, and Pearl River Delta) were found to generally have higher reclamation rates. For example, the built-up area in Shanghai, which is located in the Yangtze River Delta, increased more than five times from 1985 to 2010. Approximately 35% of the reclamation occurred in Bohai Bay, in which the CRI between 2005 and 2010 was three times higher than the average CRI over the 25-year period.« less

Public spaces and urban sustainability in the tropical built environment

NASA Astrophysics Data System (ADS)

Yusof, Y. M.; Kozlowski, M.

2018-01-01

Sustainability is an overarching sense of responsibility towards the future. On a city-wide level, urban sustainability incorporates a wide body of changes especially as they relate to the built environment, all of which intended at creating a livable place. This paper discusses existing public spaces in view of their achievement against a set of criteria for the built environment. The paper introduces performance design criteria for the tropical built environment. The key findings indicate that long-term strategies, guidance and directions for the city and region can achieve development which corresponds to local climate, synergies and provide a higher proportion of public spaces that offer something for everyone.

The Influence of Weather Variation, Urban Design and Built Environment on Objectively Measured Sedentary Behaviour in Children.

PubMed

Katapally, Tarun Reddy; Rainham, Daniel; Muhajarine, Nazeem

2016-01-01

With emerging evidence indicating that independent of physical activity, sedentary behaviour (SB) can be detrimental to health, researchers are increasingly aiming to understand the influence of multiple contexts such as urban design and built environment on SB. However, weather variation, a factor that continuously interacts with all other environmental variables, has been consistently underexplored. This study investigated the influence of diverse environmental exposures (including weather variation, urban design and built environment) on SB in children. This cross-sectional observational study is part of an active living research initiative set in the Canadian prairie city of Saskatoon. Saskatoon's neighbourhoods were classified based on urban street design into grid-pattern, fractured grid-pattern and curvilinear types of neighbourhoods. Diverse environmental exposures were measured including, neighbourhood built environment, and neighbourhood and household socioeconomic environment. Actical accelerometers were deployed between April and June 2010 (spring-summer) to derive SB of 331 10-14 year old children in 25 one week cycles. Each cycle of accelerometry was conducted on a different cohort of children within the total sample. Accelerometer data were matched with localized weather patterns derived from Environment Canada weather data. Multilevel modeling using Hierarchical Linear and Non-linear Modeling software was conducted by factoring in weather variation to depict the influence of diverse environmental exposures on SB. Both weather variation and urban design played a significant role in SB. After factoring in weather variation, it was observed that children living in grid-pattern neighbourhoods closer to the city centre (with higher diversity of destinations) were less likely to be sedentary. This study demonstrates a methodology that could be replicated to integrate geography-specific weather patterns with existing cross-sectional accelerometry data to understand the influence of urban design and built environment on SB in children.

Cancer incidence and mortality: A cohort study in China, 2008-2013.

PubMed

Pan, Rui; Zhu, Meng; Yu, Canqing; Lv, Jun; Guo, Yu; Bian, Zheng; Yang, Ling; Chen, Yiping; Hu, Zhibin; Chen, Zhengming; Li, Liming; Shen, Hongbing

2017-10-01

The National Central Cancer Registry of China (NCCR) was the only available source of cancer monitoring in China, even though only about 70% of cancer registration sites were qualified by now. In this study, based on a national large prospective cohort-the China Kadoorie Biobank (CKB), we aimed to provide additional cancer statistics and compare the difference of cancer burden between urban and rural areas of China. A total of 497,693 cancer-free participants aged 35-74 years were recruited and successfully followed up from 2004 to 2013 in 5 urban and 5 rural areas across China. Except for traditional registration systems, the national health insurance system and active follow-up were used to determine new cancer incidents and related deaths. The mortality-to-incidence ratio (MIR) was used to compare the differences of cancer burden between urban and rural areas of China. We found that cancer mortality coincided well between our cohort and NCCR, while the incidence was much higher in our cohort. Based on CKB, we found the MIR of all cancers was 0.54 in rural areas, which was approximately one-third higher than that in urban areas with 0.39. Cancer profiles in urban areas were transiting to Western distributions, which were characterized with high incidences of breast cancer and colorectal cancer; while cancers of the esophagus, liver and cervix uteri were still common in rural areas of China. Our results provide additional cancer statistics of China and demonstrate the differences of cancer burden between urban and rural areas of China. © 2017 UICC.

Residential Greenness and Birth Outcomes: Evaluating the Influence of Spatially Correlated Built-Environment Factors

PubMed Central

Davies, Hugh W.; Frank, Lawrence; Van Loon, Josh; Gehring, Ulrike; Tamburic, Lillian; Brauer, Michael

2014-01-01

Background: Half the world’s population lives in urban areas. It is therefore important to identify characteristics of the built environment that are beneficial to human health. Urban greenness has been associated with improvements in a diverse range of health conditions, including birth outcomes; however, few studies have attempted to distinguish potential effects of greenness from those of other spatially correlated exposures related to the built environment. Objectives: We aimed to investigate associations between residential greenness and birth outcomes and evaluate the influence of spatially correlated built environment factors on these associations. Methods: We examined associations between residential greenness [measured using satellite-derived Normalized Difference Vegetation Index (NDVI) within 100 m of study participants’ homes] and birth outcomes in a cohort of 64,705 singleton births (from 1999–2002) in Vancouver, British Columbia, Canada. We also evaluated associations after adjusting for spatially correlated built environmental factors that may influence birth outcomes, including exposure to air pollution and noise, neighborhood walkability, and distance to the nearest park. Results: An interquartile increase in greenness (0.1 in residential NDVI) was associated with higher term birth weight (20.6 g; 95% CI: 16.5, 24.7) and decreases in the likelihood of small for gestational age, very preterm (< 30 weeks), and moderately preterm (30–36 weeks) birth. Associations were robust to adjustment for air pollution and noise exposures, neighborhood walkability, and park proximity. Conclusions: Increased residential greenness was associated with beneficial birth outcomes in this population-based cohort. These associations did not change after adjusting for other spatially correlated built environment factors, suggesting that alternative pathways (e.g., psychosocial and psychological mechanisms) may underlie associations between residential greenness and birth outcomes. Citation: Hystad P, Davies HW, Frank L, Van Loon J, Gehring U, Tamburic L, Brauer M. 2014. Residential greenness and birth outcomes: evaluating the influence of spatially correlated built-environment factors. Environ Health Perspect 122:1095–1102; http://dx.doi.org/10.1289/ehp.1308049 PMID:25014041

Modelling heavy metals build-up on urban road surfaces for effective stormwater reuse strategy implementation.

PubMed

Hong, Nian; Zhu, Panfeng; Liu, An

2017-12-01

Urban road stormwater is an alternative water resource to mitigate water shortage issues in the worldwide. Heavy metals deposited (build-up) on urban road surface can enter road stormwater runoff, undermining stormwater reuse safety. As heavy metal build-up loads perform high variabilities in terms of spatial distribution and is strongly influenced by surrounding land uses, it is essential to develop an approach to identify hot-spots where stormwater runoff could include high heavy metal concentrations and hence cannot be reused if it is not properly treated. This study developed a robust modelling approach to estimating heavy metal build-up loads on urban roads using land use fractions (representing percentages of land uses within a given area) by an artificial neural network (ANN) model technique. Based on the modelling results, a series of heavy metal load spatial distribution maps and a comprehensive ecological risk map were generated. These maps provided a visualization platform to identify priority areas where the stormwater can be safely reused. Additionally, these maps can be utilized as an urban land use planning tool in the context of effective stormwater reuse strategy implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatiotemporal dynamics of LUCC from 2001 to 2010 in Yunnan Province, China

NASA Astrophysics Data System (ADS)

Li, Z. J.; Yu, J. S.; Yao, X. L.; Chen, X.; Li, Z. L.

2016-08-01

LUCC (Land use and land cover change) is increasingly regarded as an important component of global environmental change and sustainable development. In this study, regional land cover type maps were drawn using the MODIS products from 2001 and 2010 based on the modified classification scheme embodied by the characteristics of land cover in Yunnan. Dynamic change in each type of land cover was investigated by classification statistics, dynamic transfer matrices, and landscape pattern metrics. In addition, the driving factors of LUCC were discussed. The results showed that the land cover types of the Yunnan province, especially woodland (WL), cropland (CL) and grassland (GL), had experienced noticeable changes with an area of about 30% of land during the study period. And there was an obvious vertical distribution pattern for land cover types. The average altitude of different land cover types from the highest to the lowest were unused land (UUT), WL, GL, water (WT), urban and built-up areas (UB) and CL. The average slope for most of the land-cover types did not vary over the past 10 years. Stabilization and homogenization will be the direction of land cover in the future according to landscape metrics analysis. The regional differences of land use structure in the area are strongly influenced by such factors as the geographical position, level of economic development and land use policy. The new policy of land use, Construction of Mountainous Town, would be provided to achieve the economical and intensive utilization of land resources during the rapid development of urbanization and industrialization in Yunnan.

Urban growth in American cities : glimpses of U.S. urbanization

USGS Publications Warehouse

Auch, Roger; Taylor, Janis; Acevedo, William

2004-01-01

The Earth's surface is changing rapidly. Changes are local, regional, national, and even global in scope. Some changes have natural causes, such as earthquakes or drought. Other changes, such as urban expansion, agricultural intensification, resource extraction, and water resources development, are examples of human-induced change that have significant impact upon people, the economy, and resources. The consequences that result from these changes are often dramatic and widespread (Buchanan, Acevedo, and Zirbes, 2002)It is the role of the U.S. Geological Survey (USGS) to provide useful and relevant scientific information both to the agencies within the Department of the Interior and to the Nation in general. In an effort to comply with this task, USGS scientists are assessing the status of, and the trends in, the Nation's land surface. This assessment provides useful information for regional and national land use decisionmaking. This knowledge can be used to deal with issues of significance to the Nation, such as quality-of-life, ecology of urban environments, ecosystem health, ecological integrity, water quality and quantity concerns, resource availability, vulnerability to natural hazards, safeguards to human health, air and land quality, and accessibility to scientific information. Results of these assessments can also be analyzed to reveal rates and trends in land use change. Results from urban growth studies provide a firm foundation for continuing research that explores the consequences of human modification of the landscape.The USGS seeks to illustrate and explain the spatial history of urban growth and corresponding land use change. Scientists are studying urban environments from a regional perspective and a time scale of decades to measure the changes that have occurred in order to help understand the impact of anticipated changes in the future.Within this booklet are pairs of images of selected urbanized regions from across the Nation. These image pairs illustrate the transformation that these areas have undergone over two decades. Specifically, they depict changes in the extent of urban land. Each change pair is composed of one image from the 1970s and one image from the 1990s. Accompanying each image pair is a brief historical geography of factors that helped facilitate major changes that have occurred since the founding of the main city and the consequences and challenges of regional urban growth. The goal of this publication is to provide an illustration of urban change that is easily understood by a broad audience.The images used throughout this booklet were generated from land cover data developed by the USGS. The data sources include the Geographic Information Retrieval and Analysis System (GIRAS) for the 1970s images and the National Land Cover Dataset (NLCD) for the 1990s images. GIRAS digital maps are based on photointerpretations completed in the mid-1970s. The NLCD is a land cover dataset for the conterminous United States based on 1992 Landsat thematic mapper (TM) satellite imagery and supplemental data (fig. 1a and fig. 1b). The USGS distributes both of these land use and land cover digital datasets.The images were developed by using a geographic information system (GIS). The GIRAS and NLCD datasets were used to identify urban land within each region. In the final images all urban areas are shown in red. A shaded-relief map of each region was used to display the topographic context of the red polygon coverage. For all of these images, urban land is defined as areas transformed into a built-up environment for human use. It includes residential areas, commercial and industrial developments, transportation features, and institutions.

The Urban Food-Water Nexus: Modeling Water Footprints of Urban Agriculture using CityCrop

NASA Astrophysics Data System (ADS)

Tooke, T. R.; Lathuilliere, M. J.; Coops, N. C.; Johnson, M. S.

2014-12-01

Urban agriculture provides a potential contribution towards more sustainable food production and mitigating some of the human impacts that accompany volatility in regional and global food supply. When considering the capacity of urban landscapes to produce food products, the impact of urban water demand required for food production in cities is often neglected. Urban agricultural studies also tend to be undertaken at broad spatial scales, overlooking the heterogeneity of urban form that exerts an extreme influence on the urban energy balance. As a result, urban planning and management practitioners require, but often do not have, spatially explicit and detailed information to support informed urban agricultural policy, especially as it relates to potential conflicts with sustainability goals targeting water-use. In this research we introduce a new model, CityCrop, a hybrid evapotranspiration-plant growth model that incorporates detailed digital representations of the urban surface and biophysical impacts of the built environment and urban trees to account for the daily variations in net surface radiation. The model enables very fine-scale (sub-meter) estimates of water footprints of potential urban agricultural production. Results of the model are demonstrated for an area in the City of Vancouver, Canada and compared to aspatial model estimates, demonstrating the unique considerations and sensitivities for current and future water footprints of urban agriculture and the implications for urban water planning and policy.

Master-planned in exurbia: examining the drivers and impacts of master-planned communities at the urban fringe

Treesearch

Jenna H. Tilt; Lee Cerveny

2013-01-01

Smart growth strategies of infill and compact growth in existing suburban cities will most likely not be sufficient to absorb a new US household growth in the future. To meet housing demands and preferences, master-planned communities will continue to be built in outlying exurban areas. However, little is known about the impacts these communities may have on the...

Assessment of the landslide and flood risks in São Paulo City, Brazil

NASA Astrophysics Data System (ADS)

Vieira, Bianca; Listo, Fabrízio

2010-05-01

In Brazilian cities, especially during summer, the landslides and floods cause disaster and economic losses. Aricanduva basin is one of the most critical in the Metropolitan Region of São Paulo (RMSP), where many types of morphodynamic processes occur. This is the largest river basin in São Paulo City. The current situation is characterized by intense urbanization, soil sealing and consequent reduction of soil infiltration, increasing the frequency of flood events in this area. Thus, the main objective of this paper is to map risk areas of landslides and floods in the sub-basin Limoeiro, located in the head of the Aricanduva basin. For mapping the risk areas, we prepared a record field to floods and landslides, based on several studies. Initially, it were identified the natural indicators (vegetation, topography, surface cover and drainage) and anthropogenic (urban pattern, soil cover, building types, occupation density, road conditions, infrastructure, drainage systems, distance between houses and slope, at the top and base, and the drainage channel). On the second step of this research, we identified the evidences of mass movements (scars, cracks, subsidence, trees, poles and inclined walls). Thus, on the basis of this analysis it was possible to define the risk probability: R1 (low or no risk), R2 (moderate), R3 (high) and, R4 (very high). Subsequently, by means of oblique photographs (taken from helicopter flight) it was possible to define risk areas in the basin. In all the sectors identified, were recorded approximately 903 urban settlements. The results showed that from the 25 sectors of risk, 14 sectors (56%) presented landslide risk and 11 (44%), flood risk. Of the sectors that showed landslide risk areas, 21% have very high probability (R4), 21% high (R3), 29% moderate (R2) and 29% low (R1). The sectors at flood risk presented 45% of very high probability (R4), 10% high (R3), 18% moderate (R2) and 27% low (R1). There is large presence of sediments from landslides, debris and remnants of buildings. The drainage systems are precarious and there is runoff on the surface and sewage pipes on soil surface. Some houses were built without keeping safe distance from the top and bottom of the slope, increasing landslide risk. Others were built very close to the stream. There are cracks in the houses and walls and trees inclined by mass movements and riverbank erosion. In general, the urban occupation, after deforesting, characterized by land fragmentation and by settlements without urban infrastructure, occurred in the terrain less favorable to the occupation, where a natural susceptibility to landslides and flood processes exists. Thus, we believe that this mapping can help the identification of the active processes (landslides and floods) and the assessment of risk areas. Therefore, these maps can be used by public administration on identifying areas more appropriate to urban occupation.

An overview of 2016 WISE Urban Summer Observation Campaign (WUSOC 2016) in the Seoul metropolitan area of South Korea

NASA Astrophysics Data System (ADS)

Jung, Jae-Won; Kim, Sang-Woo; Shim, Jae-Kwan; Kwak, Kyung-Hwan

2017-04-01

The Weather Information Service Engine (WISE), launched project of the Korea Meteorological Administration (KMA), aims to operate the urban meteorological observation network from 2012 to 2019 and to test and operate the application weather service (e.g., flash flood, road weather, city ecology, city microclimate, dispersion of hazardous substance etc.) in 2019 through the development of Advanced Storm-scale Analysis Prediction System(ASAPS) for the production of storm-scale hazard weather monitoring and prediction system. The WISE institute has completed construction of 31 urban meteorological observation cities in Seoul metropolitan area and has built a real-time test operation and verification system by improving the ASAPS that produces 1 km and 6 hour forecast information based on the 5 km forecast information of KMA. Field measurements of 2016 WISE Urban Summer Observation Campaign (WUSOC 2016) was conducted in the Seoul metropolitan area of South Korea from August 22 to October 14, 2016. Involving over 70 researchers from more than 12 environmental and atmospheric science research groups in South Korea, WUSOC2016 focused on special observations, severe rain storm observations using mobile observation car and radiosonde, wind profile observations using Wind Doppler Lidar and radiosonde, etc., around the Seoul metropolitan area. WUSOC2016 purpose at data quality control, accuracy verification, usability check, and quality improvement of ASAPS at observation stations constructed in WISE. In addition, we intend to contribute to the activation of urban fusion weather research and risk weather research through joint observation and data sharing.

Modeling urbanized watershed flood response changes with distributed hydrological model: key hydrological processes, parameterization and case studies

NASA Astrophysics Data System (ADS)

Chen, Y.

2017-12-01

Urbanization is the world development trend for the past century, and the developing countries have been experiencing much rapider urbanization in the past decades. Urbanization brings many benefits to human beings, but also causes negative impacts, such as increasing flood risk. Impact of urbanization on flood response has long been observed, but quantitatively studying this effect still faces great challenges. For example, setting up an appropriate hydrological model representing the changed flood responses and determining accurate model parameters are very difficult in the urbanized or urbanizing watershed. In the Pearl River Delta area, rapidest urbanization has been observed in China for the past decades, and dozens of highly urbanized watersheds have been appeared. In this study, a physically based distributed watershed hydrological model, the Liuxihe model is employed and revised to simulate the hydrological processes of the highly urbanized watershed flood in the Pearl River Delta area. A virtual soil type is then defined in the terrain properties dataset, and its runoff production and routing algorithms are added to the Liuxihe model. Based on a parameter sensitive analysis, the key hydrological processes of a highly urbanized watershed is proposed, that provides insight into the hydrological processes and for parameter optimization. Based on the above analysis, the model is set up in the Songmushan watershed where there is hydrological data observation. A model parameter optimization and updating strategy is proposed based on the remotely sensed LUC types, which optimizes model parameters with PSO algorithm and updates them based on the changed LUC types. The model parameters in Songmushan watershed are regionalized at the Pearl River Delta area watersheds based on the LUC types of the other watersheds. A dozen watersheds in the highly urbanized area of Dongguan City in the Pearl River Delta area were studied for the flood response changes due to urbanization, and the results show urbanization has big impact on the watershed flood responses. The peak flow increased a few times after urbanization which is much higher than previous reports.

Urban and non-urban differences in community living and participation among individuals with serious mental illnesses.

PubMed

Townley, Greg; Brusilovskiy, Eugene; Salzer, Mark S

2017-03-01

Despite a wealth of studies examining the relationship between urbanicity (i.e., living in an urban area) and psychological distress, there is a paucity of research examining the relationship between urbanicity, community living, and community participation of adults with serious mental illnesses. This study addresses this knowledge gap by assessing urban and non-urban differences in community participation, sense of community, mental health stigma, and perceptions of the neighborhood environment among individuals with serious mental illnesses living independently throughout the United States. A total of 300 individuals with serious mental illnesses recruited from 21 outpatient mental health service organizations in 15 states completed a phone survey about their community living and participation experiences. Urbanicity was examined at two spatial scales (block group and county), and independent-samples t-tests were employed to assess urban and non-urban differences in community living and participation variables. Levels of community participation and perceptions of neighborhood quality and crime were higher in urban block groups; sense of community was higher in urban counties; and perceptions of mental health stigma were higher in non-urban counties. Results inform the methodological literature on best practices for assessing urbanicity, as well as interventions aimed at increasing community participation and improving aspects of the built and social environment that affect individuals who experience mental health distress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Advanced DInSAR analysis for building damage assessment in large urban areas: an application to the city of Roma, Italy

NASA Astrophysics Data System (ADS)

D'Aranno, Peppe J. V.; Marsella, Maria; Scifoni, Silvia; Scutti, Marianna; Sonnessa, Alberico; Bonano, Manuela

2015-10-01

Remote sensing data play an important role for the environmental monitoring because they allow to provide systematic information on very large areas and for a long period of time. Such information must be analyzed, validated and incorporated into proper modeling tools in order to become useful for performing risk assessment analysis. These approaches has been already applied in the field of natural hazard evaluation (i.e. for monitoring seismic, volcanic areas and landslides). However, not enough attention has been devoted to the development of validated methods for implementing quantitative analysis on civil structures. This work is dedicated to the comprehensive utilization of ERS / ENVISAT data store ESA SAR used to detect deformation trends and perform back-analysis of the investigated structures useful to calibrate the damage assessment models. After this preliminary analysis, SAR data of the new satellite mission (ie Cosmo SkyMed) were adopted to monitor the evolution of existent surface deformation processes and to detect new occurrence. The specific objective was to set up a data processing and data analysis chain tailored on a service that sustains the safe maintenance of the built-up environment, including critical construction such as public (schools, hospital, etc), strategic (dam, highways, etc) and also the cultural heritage sites. The analysis of the test area, in the southeastern sector of Roma, has provided three different levels and sub-levels of products from metropolitan area scale (territorial analysis), settlement scale (aggregated analysis) to single structure scale (damage degree associated to the structure).

Modeling Global Urbanization Supported by Nighttime Light Remote Sensing

NASA Astrophysics Data System (ADS)

Zhou, Y.

2015-12-01

Urbanization, a major driver of global change, profoundly impacts our physical and social world, for example, altering carbon cycling and climate. Understanding these consequences for better scientific insights and effective decision-making unarguably requires accurate information on urban extent and its spatial distributions. In this study, we developed a cluster-based method to estimate the optimal thresholds and map urban extents from the nighttime light remote sensing data, extended this method to the global domain by developing a computational method (parameterization) to estimate the key parameters in the cluster-based method, and built a consistent 20-year global urban map series to evaluate the time-reactive nature of global urbanization (e.g. 2000 in Fig. 1). Supported by urban maps derived from nightlights remote sensing data and socio-economic drivers, we developed an integrated modeling framework to project future urban expansion by integrating a top-down macro-scale statistical model with a bottom-up urban growth model. With the models calibrated and validated using historical data, we explored urban growth at the grid level (1-km) over the next two decades under a number of socio-economic scenarios. The derived spatiotemporal information of historical and potential future urbanization will be of great value with practical implications for developing adaptation and risk management measures for urban infrastructure, transportation, energy, and water systems when considered together with other factors such as climate variability and change, and high impact weather events.

Changing ecosystem service values following technological change.

PubMed

Honey-Rosés, Jordi; Schneider, Daniel W; Brozović, Nicholas

2014-06-01

Research on ecosystem services has focused mostly on natural areas or remote places, with less attention given to urban ecosystem services and their relationship with technological change. However, recent work by urban ecologists and urban designers has more closely examined and appreciated the opportunities associated with integrating natural and built infrastructures. Nevertheless, a perception remains in the literature on ecosystem services that technology may easily and irreversibly substitute for services previously obtained from ecosystems, especially when the superiority of the engineered system motivated replacement in the first place. We emphasize that the expected tradeoff between natural and manufactured capital is false. Rather, as argued in other contexts, the adoption of new technologies is complementary to ecosystem management. The complementarity of ecosystem services and technology is illustrated with a case study in Barcelona, Spain where the installation of sophisticated water treatment technology increased the value of the ecosystem services found there. Interestingly, the complementarity between natural and built infrastructures may remain even for the very ecosystems that are affected by the technological change. This finding suggests that we can expect the value of ecosystem services to co-evolve with new technologies. Technological innovation can generate new opportunities to harness value from ecosystems, and the engineered structures found in cities may generate more reliance on ecosystem processes, not less.

Urban sprawl and body mass index among displaced Hurricane Katrina survivors.

PubMed

Arcaya, Mariana; James, Peter; Rhodes, Jean E; Waters, Mary C; Subramanian, S V

2014-08-01

Existing research suggests that walkable environments are protective against weight gain, while sprawling neighborhoods may pose health risks. Using prospective data on displaced Hurricane Katrina survivors, we provide the first natural experimental data on sprawl and body mass index (BMI). The analysis uses prospectively collected pre- (2003-2005) and post-hurricane (2006-2007) data from the Resilience in Survivors of Katrina (RISK) project on 280 displaced Hurricane Katrina survivors who had little control over their neighborhood placement immediately after the disaster. The county sprawl index, a standardized measure of built environment, was used to predict BMI at follow-up, adjusted for baseline BMI and sprawl; hurricane-related trauma; and demographic and economic characteristics. Respondents from 8 New Orleans-area counties were dispersed to 76 counties post-Katrina. Sprawl increased by an average of 1.5 standard deviations (30 points) on the county sprawl index. Each one point increase in sprawl was associated with approximately .05kg/m(2) higher BMI in unadjusted models (95%CI: .01-.08), and the relationship was not attenuated after covariate adjustment. We find a robust association between residence in a sprawling county and higher BMI unlikely to be caused by self-selection into neighborhoods, suggesting that the built environment may foster changes in weight. Copyright © 2014 Elsevier Inc. All rights reserved.

Urban Sprawl and Body Mass Index Among Displaced Hurricane Katrina Survivors

PubMed Central

Arcaya, Mariana; James, Peter; Rhodes, Jean; Waters, Mary C; Subramanian, S V

2014-01-01

Objective Existing research suggests that walkable environments are protective against weight gain, while sprawling neighborhoods may pose health risks. Using prospective data on displaced Hurricane Katrina survivors, we provide the first natural experimental data on sprawl and body mass index (BMI). Methods The analysis uses prospectively collected pre- (2003–2005) and post-hurricane (2006–2007) data from the Resilience in Survivors of Katrina (RISK) project on 280 displaced Hurricane Katrina survivors who had little control over their neighborhood placement immediately after the disaster. The county sprawl index, a standardized measure of built environment, was used to predict BMI at follow-up, adjusted for baseline BMI and sprawl; Hurricane-related trauma; and demographic and economic characteristics. Results Respondents from 8 New Orleans-area counties were dispersed to 76 counties post-Katrina. Sprawl increased by an average of 1.5 standard deviations (30 points) on the county sprawl index. Each one point increase in sprawl was associated with approximately .05 kg/m2 higher BMI in unadjusted models (95%CI: .01–.08), and the relationship was not attenuated after covariate adjustment. Conclusions We find a robust association between residence in a sprawling county and higher BMI unlikely to be caused by self-selection into neighborhoods, suggesting that the built environment may foster changes in weight. PMID:24732717

Modeling urban expansion in Yangon, Myanmar using Landsat time-series and stereo GeoEye Images

NASA Astrophysics Data System (ADS)

Sritarapipat, Tanakorn; Takeuchi, Wataru

2016-06-01

This research proposed a methodology to model the urban expansion based dynamic statistical model using Landsat and GeoEye Images. Landsat Time-Series from 1978 to 2010 have been applied to extract land covers from the past to the present. Stereo GeoEye Images have been employed to obtain the height of the building. The class translation was obtained by observing land cover from the past to the present. The height of the building can be used to detect the center of the urban area (mainly commercial area). It was assumed that the class translation and the distance of multi-centers of the urban area also the distance of the roads affect the urban growth. The urban expansion model based on the dynamic statistical model was defined to refer to three factors; (1) the class translation, (2) the distance of the multicenters of the urban areas, and (3) the distance from the roads. Estimation and prediction of urban expansion by using our model were formulated and expressed in this research. The experimental area was set up in Yangon, Myanmar. Since it is the major of country's economic with more than five million population and the urban areas have rapidly increased. The experimental results indicated that our model of urban expansion estimated urban growth in both estimation and prediction steps in efficiency.

From poison ponds to pleasure spots.

PubMed

Rao, E Nageswara

2008-10-01

The Hyderabad Metropolitan Area had 562 lakes at one time, but only 162 now remain. These are polluted to various degrees and pose environmental and health hazards. The Hussain Sagar Lake provided water for irrigation and drinking until 1930 and supported aquatic life till 1976. It is now contaminated by organic chemicals discharged by many industrial estates in its basin. An estimated 28,190 cmum of industrial effluents and domestic sewage are let into it daily. Phenols, benzenes, cyanides, and toxic metals make it poisonous. The ground water around the lake is also polluted. The polluted lakes ruin vegetable farms, kill fetuses in the womb, and cause mental retardation, still births, and infertility. In the city's outskirts, clinically confirmed cancer is 11 times higher and heart ailments 16 times more than elsewhere. The Hyderabad Urban Development Authority (HUDA) took up a Lake Conservation and Restoration Project as part of its Green Environment Program in 2002. Several lakes have been restored by setting up effluent (or sewage) treatment plants. HUDA also built lake parks with recreation facilities and environment education centers. HUDA also organized jointly with the World Water Institute, Pune, India, an international workshop on urban lake conservation and management in June 2003. It adopted the Hyderabad Declaration which, among other things, states the worthy aim of restoring all the water bodies by 2009. Even if it takes a few more years, the restoration of all the polluted lakes will usher in multiple benefits to Hyderabad citizens.

Impact of urban sprawl on overweight, obesity, and physical activity in Sydney, Australia.

PubMed

Garden, Frances L; Jalaludin, Bin B

2009-01-01

Obesity and inadequate physical activity are major risk factors for many diseases. The built environment plays an important role in influencing participation in physical activity. We aimed to determine whether urban sprawl in Sydney, Australia is associated with overweight/obesity and levels of physical activity. We used a cross-sectional multilevel study design to relate urban sprawl (based on population density) measured at an area level to overweight/obesity and levels of physical activity measured at an individual level whilst controlling for individual and area level covariates in metropolitan Sydney. Individual level data were obtained from the 2002 and 2003 New South Wales Population Health Survey. We had information on 7,290 respondents. The mean population density was 2,168 persons per square kilometer (standard deviation=1,741, range=218-7,045). After controlling for individual and area level covariates, for an inter-quartile increase in sprawl, the odds of being overweight was 1.26 (95% CI=1.10-1.44), the odds of being obese was 1.47 (95% CI=1.24-1.75), the odds of inadequate physical activity was 1.38 (95% CI=1.21-1.57), and the odds of not spending any time walking during the past week was 1.58 (95% CI=1.28-1.93). Living in more sprawling suburbs increases the risk of overweight/obesity and inadequate physical activity despite the relatively low levels of urban sprawl in metropolitan Sydney. Modifications to the urban environment to increase physical activity may be worthwhile.

Emissions of nitrogen oxides from US urban areas: estimation from Ozone Monitoring Instrument retrievals for 2005-2014

DOE PAGES

Lu, Z.; Streets, D. G.; de Foy, B.; ...

2015-05-28

Satellite remote sensing of tropospheric nitrogen dioxide (NO 2) can provide valuable information for estimating surface nitrogen oxides (NO x) emissions. Using an exponentially-modified Gaussian (EMG) method and taking into account the effect of wind on observed NO 2 distributions, we estimate three-year moving-average emissions of summertime NO x from 35 US urban areas directly from NO 2 retrievals of the Ozone Monitoring Instrument (OMI) during 2005–2014. Following the conclusions of previous studies that the EMG method provides robust and accurate emission estimates under strong-wind conditions, we derive top-down NO x emissions from each urban area by applying the EMGmore » method to OMI data with wind speeds greater than 3–5 m s -1. Meanwhile, we find that OMI NO 2 observations under weak-wind conditions (i.e., < 3 m s -1) are qualitatively better correlated with the surface NO x source strength in comparison to all-wind OMI maps; and therefore we use them to calculate the satellite-observed NO 2 burdens of urban areas and compare with NO x emission estimates. The EMG results show that OMI-derived NO x emissions are highly correlated ( R > 0.93) with weak-wind OMI NO 2 burdens as well as bottom-up NO x emission estimates over 35 urban areas, implying a linear response of the OMI observations to surface emissions under weak-wind conditions. The simultaneous, EMG-obtained, effective NO 2 lifetimes (~3.5 ± 1.3 h), however, are biased low in comparison to the summertime NO 2 chemical lifetimes. In general, isolated urban areas with NO x emission intensities greater than ~ 2 Mg h -1 produce statistically significant weak-wind signals in three-year average OMI data. From 2005 to 2014, we estimate that total OMI-derived NO x emissions over all selected US urban areas decreased by 49%, consistent with reductions of 43, 47, 49, and 44% in the total bottom-up NO x emissions, the sum of weak-wind OMI NO 2 columns, the total weak-wind OMI NO 2 burdens, and the averaged NO 2 concentrations, respectively, reflecting the success of NO x control programs for both mobile sources and power plants. The decrease rates of these NO x-related quantities are found to be faster (i.e., -6.8 to -9.3% yr -1) before 2010 and slower (i.e., -3.4 to -4.9% yr -1) after 2010. For individual urban areas, we calculate the R values of pair-wise trends among the OMI-derived and bottom-up NO x emissions, the weak-wind OMI NO 2 burdens, and ground-based NO 2 measurements; and high correlations are found for all urban areas (median R = 0.8), particularly large ones ( R up to 0.97). The results of the current work indicate that using the EMG method and considering the wind effect, the OMI data allow for the estimation of NO x emissions from urban areas and the direct constraint of emission trends with reasonable accuracy.« less

Emissions of nitrogen oxides from US urban areas: estimation from Ozone Monitoring Instrument retrievals for 2005–2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Z.; Streets, D. G.; de Foy, B.

Satellite remote sensing of tropospheric nitrogen dioxide (NO 2) can provide valuable information for estimating surface nitrogen oxides (NO x) emissions. Using an exponentially modified Gaussian (EMG) method and taking into account the effect of wind on observed NO 2 distributions, we estimate 3-year moving-average emissions of summertime NO x from 35 US (United States) urban areas directly from NO 2 retrievals of the Ozone Monitoring Instrument (OMI) during 2005–2014. Following conclusions of previous studies that the EMG method provides robust and accurate emission estimates under strong-wind conditions, we derive top-down NO x emissions from each urban area by applyingmore » the EMG method to OMI data with wind speeds greater than 3–5 m s -1. Meanwhile, we find that OMI NO 2 observations under weak-wind conditions (i.e., < 3 m s −1) are qualitatively better correlated to the surface NO x source strength in comparison to all-wind OMI maps; therefore, we use them to calculate the satellite-observed NO 2 burdens of urban areas and compare with NO x emission estimates. The EMG results show that OMI-derived NO x emissions are highly correlated ( R > 0.93) with weak-wind OMI NO 2 burdens as well as with bottom-up NO x emission estimates over 35 urban areas, implying a linear response of the OMI observations to surface emissions under weak-wind conditions. The simultaneous EMG-obtained effective NO 2 lifetimes (~ 3.5 ± 1.3 h), however, are biased low in comparison to the summertime NO 2 chemical lifetimes. In general, isolated urban areas with NO x emission intensities greater than ~ 2 Mg h -1 produce statistically significant weak-wind signals in 3-year average OMI data. From 2005 to 2014, we estimate that total OMI-derived NO x emissions over all selected US urban areas decreased by 49 %, consistent with reductions of 43, 47, 49, and 44 % in the total bottom-up NO x emissions, the sum of weak-wind OMI NO 2 columns, the total weak-wind OMI NO 2 burdens, and the averaged NO 2 concentrations, respectively, reflecting the success of NO x control programs for both mobile sources and power plants. The decrease rates of these NO x-related quantities are found to be faster (i.e., -6.8 to -9.3 % yr −1) before 2010 and slower (i.e., -3.4 to -4.9 % yr −1) after 2010. For individual urban areas, we calculate the R values of pair-wise trends among the OMI-derived and bottom-up NO x emissions, the weak-wind OMI NO 2 burdens, and ground-based NO 2 measurements, and high correlations are found for all urban areas (median R= 0.8), particularly large ones ( R up to 0.97). The results of the current work indicate that using the EMG method and considering the wind effect, the OMI data allow for the estimation of NO x emissions from urban areas and the direct constraint of emission trends with reasonable accuracy.« less

Emissions of nitrogen oxides from US urban areas: estimation from Ozone Monitoring Instrument retrievals for 2005-2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Z.; Streets, D. G.; de Foy, B.

Satellite remote sensing of tropospheric nitrogen dioxide (NO 2) can provide valuable information for estimating surface nitrogen oxides (NO x) emissions. Using an exponentially-modified Gaussian (EMG) method and taking into account the effect of wind on observed NO 2 distributions, we estimate three-year moving-average emissions of summertime NO x from 35 US urban areas directly from NO 2 retrievals of the Ozone Monitoring Instrument (OMI) during 2005–2014. Following the conclusions of previous studies that the EMG method provides robust and accurate emission estimates under strong-wind conditions, we derive top-down NO x emissions from each urban area by applying the EMGmore » method to OMI data with wind speeds greater than 3–5 m s -1. Meanwhile, we find that OMI NO 2 observations under weak-wind conditions (i.e., < 3 m s -1) are qualitatively better correlated with the surface NO x source strength in comparison to all-wind OMI maps; and therefore we use them to calculate the satellite-observed NO 2 burdens of urban areas and compare with NO x emission estimates. The EMG results show that OMI-derived NO x emissions are highly correlated ( R > 0.93) with weak-wind OMI NO 2 burdens as well as bottom-up NO x emission estimates over 35 urban areas, implying a linear response of the OMI observations to surface emissions under weak-wind conditions. The simultaneous, EMG-obtained, effective NO 2 lifetimes (~3.5 ± 1.3 h), however, are biased low in comparison to the summertime NO 2 chemical lifetimes. In general, isolated urban areas with NO x emission intensities greater than ~ 2 Mg h -1 produce statistically significant weak-wind signals in three-year average OMI data. From 2005 to 2014, we estimate that total OMI-derived NO x emissions over all selected US urban areas decreased by 49%, consistent with reductions of 43, 47, 49, and 44% in the total bottom-up NO x emissions, the sum of weak-wind OMI NO 2 columns, the total weak-wind OMI NO 2 burdens, and the averaged NO 2 concentrations, respectively, reflecting the success of NO x control programs for both mobile sources and power plants. The decrease rates of these NO x-related quantities are found to be faster (i.e., -6.8 to -9.3% yr -1) before 2010 and slower (i.e., -3.4 to -4.9% yr -1) after 2010. For individual urban areas, we calculate the R values of pair-wise trends among the OMI-derived and bottom-up NO x emissions, the weak-wind OMI NO 2 burdens, and ground-based NO 2 measurements; and high correlations are found for all urban areas (median R = 0.8), particularly large ones ( R up to 0.97). The results of the current work indicate that using the EMG method and considering the wind effect, the OMI data allow for the estimation of NO x emissions from urban areas and the direct constraint of emission trends with reasonable accuracy.« less

Evaluation of an atmospheric model with surface and ABL meteorological data for energy applications in structured areas

NASA Astrophysics Data System (ADS)

Triantafyllou, A. G.; Kalogiros, J.; Krestou, A.; Leivaditou, E.; Zoumakis, N.; Bouris, D.; Garas, S.; Konstantinidis, E.; Wang, Q.

2018-03-01

This paper provides the performance evaluation of the meteorological component of The Air Pollution Model (TAPM), a nestable prognostic model, in predicting meteorological variables in urban areas, for both its surface layer and atmospheric boundary layer (ABL) turbulence parameterizations. The model was modified by incorporating four urban land surface types, replacing the existing single urban surface. Control runs were carried out over the wider area of Kozani, an urban area in NW Greece. The model was evaluated for both surface and ABL meteorological variables by using measurements of near-surface and vertical profiles of wind and temperature. The data were collected by using monitoring surface stations in selected sites as well as an acoustic sounder (SOnic Detection And Ranging (SODAR), up to 300 m above ground) and a radiometer profiler (up to 600 m above ground). The results showed the model demonstrated good performance in predicting the near-surface meteorology in the Kozani region for both a winter and a summer month. In the ABL, the comparison showed that the model's forecasts generally performed well with respect to the thermal structure (temperature profiles and ABL height) but overestimated wind speed at the heights of comparison (mostly below 200 m) up to 3-4 ms-1.

Reducing Community Vulnerability to Wildland Fires in Southern California

NASA Astrophysics Data System (ADS)

Keeley, J. E.

2010-12-01

In the US fires are not treated like other hazards such as earthquakes but rather as preventable through landscape fuel treatments and aggressive fire suppression. In southern California extreme fire weather has made it impossible to control all fires and thus loss of homes and lives is a constant threat to communities. There is growing evidence that indicate we are not likely to ever eliminate fires on these landscapes. Thus, it is time to reframe the fire problem and think of fires like we do with other natural hazards such as earthquakes. We do not attempt to stop earthquakes, rather the primary emphasis is on altering human infrastructure in ways that minimize community vulnerability. In other words we need to change our approach from risk elimination to risk management. This approach means we accept that we cannot eliminate fires but rather learn to live with fire by communities becoming more fire adapted. We potentially can make great strides in reducing community vulnerability by finding those factors with high impacts and are sensitive to changes in management. Presently, decision makers have relatively little guidance about which of these is likely to have the greatest impact. Future reductions in fire risk to communities requires we address both wildland and urban elements that contribute to destructive losses. Damage risk or D is determined by: D = f (I, S, E, G, H) where I = the probability of a fire starting in the landscape S = the probability of the fire reaching a size sufficient to reach the urban environment E = probability of it encroaching into the urban environment G = probability of fire propagating within the built environment H = probability of a fire, once within the built environment, resulting in the destruction of a building. In southern California, reducing I through more strategic fire prevention has potential for reducing fire risk. There are many ignition sources that could be reduced, such as replacing power line ignitions with underground lines, strategically employing arson patrols during Santa Ana wind events, enforcing regulations on power equipment use in wildland areas, k-rail barriers along roads to reduce fire spread into wildland areas etc. S, or the probability of fire reaching urban environments has historically been the primary focus of state and federal fire management activities. There is a need for greater focus on understanding the most strategic application of wildland fuel treatments. E, the probability of fire encroaching into the urban environment, has largely been addressed in the past by attention to wildland-urban interface (WUI) fuel treatments. The one factor that has perhaps the greatest potential for impacting E are patterns of urban growth, both in strategic placement and spatial patterning within communities, and this is an area where alternative future growth scenarios could have huge impacts on fire outcomes. G, the chance of fire propagating within the urban environment is a function of urban fuels, which include both home construction and landscaping. This area has the potential for effecting large changes in fire losses dependent upon future regulations on plantings in the urban environment.

Whose Sense of Place? Re-thinking Place Concept and Urban Heritage Conservation in Social Media Era

NASA Astrophysics Data System (ADS)

Dameria, Christin; Akbar, Roos; Natalivan Indradjati, Petrus

2018-05-01

A change in a conservation approach that is now more focused on the conservation of a place than on a single object has placed an understanding of a place as an important concept that must be understood in urban heritage planning. However, the urban place perspective has been shifted, as a result of the change of attitude of people living in the urban area due to the rising of social media. This paper argues the concept of place in the heritage conservation planning, especially in the area designed to be tourism objects, which needs to be revisited. The very dynamic urban people as a result of technology and information must be considered. In order to understand the man-place relationship, the sense of place concept is the most common concept used and in the current context of heritage conservation, the review of place concept could be traced by understanding who is the owner of a sense of place in the social media era. In the current academic literature, the common discourse says the local community as the owner of the sense of place because visitors have limited chance to own the sense of place. This paper also argues that the shift of place perspective due to social media could be the catalyst in creating a strong sense of place for visitors. To support the argument, this paper uses the study of Concept of Mediatization and Concept of Parochial that have successfully explained how social media provides indirect experience based on people-place interaction and a sense of familiarity of an unknown or strange place. Therefore, this paper states that in the sense of place context: (1) the experience factor, as one of the factors in the creation of a sense of place, does not need to be physically experienced but it can be built based on other person’s personal reflection. It also gives an opportunity to make a self-interpretation about the value of the heritage place; (2) sense of familiarity, which is believed to be owned by the locals only due to the period of staying in the area, can be owned by persons who have never visited the place. That is why when the tourists come to visit the heritage place with their own interpretation of experience built previously they are very potential to have a strong sense of place when doing activities in such short time of visit. In the context of heritage planning, this change will certainly have an impact on (1) the change of the stakeholder mapping of urban heritage area conservation, and (2) the change of place-making concept in an effort to conserve the public space of heritage areas, where heritage planning needs to make room for digital dimension contribution as one form of advancement in information technology that has become the urban lifestyle of today.

Geospatial Analysis of Atmospheric Haze Effect by Source and Sink Landscape

NASA Astrophysics Data System (ADS)

Yu, T.; Xu, K.; Yuan, Z.

2017-09-01

Based on geospatial analysis model, this paper analyzes the relationship between the landscape patterns of source and sink in urban areas and atmospheric haze pollution. Firstly, the classification result and aerosol optical thickness (AOD) of Wuhan are divided into a number of square grids with the side length of 6 km, and the category level landscape indices (PLAND, PD, COHESION, LPI, FRAC_MN) and AOD of each grid are calculated. Then the source and sink landscapes of atmospheric haze pollution are selected based on the analysis of the correlation between landscape indices and AOD. Next, to make the following analysis more efficient, the indices selected before should be determined through the correlation coefficient between them. Finally, due to the spatial dependency and spatial heterogeneity of the data used in this paper, spatial autoregressive model and geo-weighted regression model are used to analyze atmospheric haze effect by source and sink landscape from the global and local level. The results show that the source landscape of atmospheric haze pollution is the building, and the sink landscapes are shrub and woodland. PLAND, PD and COHESION are suitable for describing the atmospheric haze effect by source and sink landscape. Comparing these models, the fitting effect of SLM, SEM and GWR is significantly better than that of OLS model. The SLM model is superior to the SEM model in this paper. Although the fitting effect of GWR model is more unsuited than that of SLM, the influence degree of influencing factors on atmospheric haze of different geography can be expressed clearer. Through the analysis results of these models, following conclusions can be summarized: Reducing the proportion of source landscape area and increasing the degree of fragmentation could cut down aerosol optical thickness; And distributing the source and sink landscape evenly and interspersedly could effectively reduce aerosol optical thickness which represents atmospheric haze pollution; For Wuhan City, the method of adjusting the built-up area slightly and planning the non-built-up areas reasonably can be taken to reduce atmospheric haze pollution.

Mass balance and decontamination times of Polycyclic Aromatic Hydrocarbons in rural nested catchments of an early industrialized region (Seine River basin, France).

PubMed

Gateuille, David; Evrard, Olivier; Lefevre, Irène; Moreau-Guigon, Elodie; Alliot, Fabrice; Chevreuil, Marc; Mouchel, Jean-Marie

2014-02-01

Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in soils and their subsequent release in rivers constitute a major environmental and public health problem in industrialized countries. In the Seine River basin (France), some PAHs exceed the target concentrations, and the objectives of good chemical status required by the European Water Framework Directive might not be achieved. This investigation was conducted in an upstream subcatchment where atmospheric fallout (n=42), soil (n=33), river water (n=26) and sediment (n=101) samples were collected during one entire hydrological year. PAH concentrations in atmospheric fallout appeared to vary seasonally and to depend on the distance to urban areas. They varied between 60 ng·L(-1) (in a remote site during autumn) and 2,380 ng·L(-1) (in a built-up area during winter). PAH stocks in soils of the catchment were estimated based on land use, as mean PAH concentrations varied between 110 ng·g(-1) under woodland and 2,120 ng·g(-1) in built-up areas. They ranged from 12 to 220 kg·km(-2). PAH contamination in the aqueous phase of rivers remained homogeneous across the catchment (72 ± 38 ng·L(-1)). In contrast, contamination of suspended solid was heterogeneous depending on hydrological conditions and population density in the drainage area. Moreover, PAH concentrations appeared to be higher in sediment (230-9,210 ng·g(-1)) than in the nearby soils. Annual mass balance calculation conducted at the catchment scale showed that current PAH losses were mainly due to dissipation (biodegradation, photo-oxidation and volatilization) within the catchments (about 80%) whereas exports due to soil erosion and riverine transport appeared to be of minor importance. Based on the calculated fluxes, PAHs appeared to have long decontamination times in soils (40 to 1,850 years) thereby compromising the achievement of legislative targets. Overall, the study highlighted the major role of legacy contamination that supplied the bulk of PAHs that are still found nowadays in the environment. © 2013.