Modeling the Surface Energy Balance of the Core of an Old Mediterranean City: Marseille.

Science.gov (United States)

Lemonsu, A.; Grimmond, C. S. B.; Masson, V.

2004-02-01

The Town Energy Balance (TEB) model, which parameterizes the local-scale energy and water exchanges between urban surfaces and the atmosphere by treating the urban area as a series of urban canyons, coupled to the Interactions between Soil, Biosphere, and Atmosphere (ISBA) scheme, was run in offline mode for Marseille, France. TEB's performance is evaluated with observations of surface temperatures and surface energy balance fluxes collected during the field experiments to constrain models of atmospheric pollution and transport of emissions (ESCOMPTE) urban boundary layer (UBL) campaign. Particular attention was directed to the influence of different surface databases, used for input parameters, on model predictions. Comparison of simulated canyon temperatures with observations resulted in improvements to TEB parameterizations by increasing the ventilation. Evaluation of the model with wall, road, and roof surface temperatures gave good results. The model succeeds in simulating a sensible heat flux larger than heat storage, as observed. A sensitivity comparison using generic dense city parameters, derived from the Coordination of Information on the Environment (CORINE) land cover database, and those from a surface database developed specifically for the Marseille city center shows the importance of correctly documenting the urban surface. Overall, the TEB scheme is shown to be fairly robust, consistent with results from previous studies.

Energy-urban transition: The Mexican case

International Nuclear Information System (INIS)

Paez, Armando

2010-01-01

In this paper I present a study regarding the institutional conditions of Mexican cities based on a post-petroleum urban model that considers transport, architecture, urban planning and land use, renewable energy sources, energy saving and efficiency, and urban metabolism issues. The model was constructed with recommendations of authors and organizations that have analysed the energy dimension of cities under an energy-availability, environmental or petroleum-independent view. To make the study I sent a questionnaire to some local governments of all the country. The information indicates that Mexican cities do not have institutional conditions to manage the urban-energy transition that signify the end of cheap oil and the peak of world oil production.

Impact of the urban heat island on residents’ energy consumption: a case study of Qingdao

Science.gov (United States)

Ding, Feng; Pang, Huaji; Guo, Wenhui

2018-02-01

This paper examines impact of urban heat island on residents’ energy consumption through comparative analyses of monthly air temperature data observed in Qingdao, Laoshan and Huangdao weather stations. The results show effect of urban heat island is close related with urbanization speed. Recently, effects of urban heat island of Laoshan and Huangdao exceed that of Qingdao, consistent with rapid urbanization in Laoshan and Huangdao. Enhanced effect of urban heat island induces surface air temperature to rise up, further increase electricity energy consumption for air conditioning use in summer and reduce coal consumption for residents heating in winter. Comparing change of residents’ energy consumption in summer and winter, increments in summer are less than reduction in winter. This implicates effect of urban heat island is more obvious in winter than in summer.

Decoupling emissions of greenhouse gas, urbanization, energy and income: analysis from the economy of China.

Science.gov (United States)

Wang, Tianqiong; Riti, Joshua Sunday; Shu, Yang

2018-05-08

The adoption and ratification of relevant policies, particularly the household enrolment system metamorphosis in China, led to rising urbanization growth. As the leading developing economy, China has experienced a drastic and rapid increase in the rate of urbanization, energy use, economic growth and greenhouse gas (GHG) pollution for the past 30 years. The knowledge of the dynamic interrelationships among these trends has a plethora of implications ranging from demographic, energy, and environmental and sustainable development policies. This study analyzes the role of urbanization in decoupling GHG emissions, energy, and income in China while considering the critical contribution of energy use. As a contribution to the extant body of literature, the present research introduces a new phenomenon called "the environmental urbanization Kuznets curve" (EUKC), which shows that at the early stage of urbanization, the environment degrades however, after a threshold point the technique effects surface and environmental degradation reduces with rise in urbanization. Applying the autoregressive distributed lag model and the vector error correction model, the paper finds the presence of inverted U-shaped curve between urbanization and GHG emission of CO 2 , while the same hypothesis cannot be found between income and GHG emission of CO 2 . Energy use in all the models contributes to GHG emission of CO 2 . In decoupling greenhouse gas emissions, urbanization, energy, and income, articulated and well-implemented energy and urbanization policies should be considered.

Urban energy planning in Turku

DEFF Research Database (Denmark)

Fertner, Christian; Christensen, Emil Maj; Große, Juliane

prevailing urban sprawl, characterising urban development since the 1950s. The city is densifying and promoting sustainable urban develop-ment, though at a regional scale with several growth centres. Its future development is envisioned in the “Structure model 2035”, focusing on more compact urban...... development along public transport corridors. From the case report three issues arise which might be of considerable interest in a broader context of the PLEEC project: 1. Working with energy efficient regional urban structure (e.g. regarding urban sprawl) in a low density country and on a voluntary...

Development of an Urban Multilayer Radiation Scheme and Its Application to the Urban Surface Warming Potential

Science.gov (United States)

Aoyagi, Toshinori; Takahashi, Shunji

2012-02-01

To investigate how a three-dimensional structure such as an urban canyon can affect urban surface warming, we developed an urban multilayer radiation scheme. The complete consideration of multiple scattering of shortwave and longwave radiation using the radiosity method is an important feature of the present scheme. A brief description of this scheme is presented, followed by evaluations that compare its results with observations of the effective albedo and radiative temperature for urban blocks. Next, we calculate the urban surface warming potential (USWP), defined as the difference between the daily mean radiative temperature of urban surfaces (which are assumed to be black bodies), including their canyon effects and the daily mean temperature of a flat surface with the same material properties, under a radiative equilibrium state. Assuming standard material properties (albedo and emissivity of 0.4 and 0.9, respectively), we studied the sensitivity of the USWP to various aspect ratios of building heights to road widths. The results show that the temporally-averaged surface temperature of an urban area can be higher than that of a flat surface. In addition, we determined the overestimation of the effective temperature of urban surfaces induced by the overestimation of the radiation distribution to the walls when one uses a single-layer scheme for urban block arrays that have a low sky-view factor less than around 0.5.

Can urban rail transit curb automobile energy consumption?

International Nuclear Information System (INIS)

Lin, Boqiang; Du, Zhili

2017-01-01

With the rapid development of China's economy and the speed of urbanization, China's automobile sector has experienced rapid development. The rapid development of the automobile sector has increased energy consumption. According to the results of this paper, automobile energy consumption accounted for about 10.73% of total energy consumption in China in 2015, about 3.6 times the proportion a decade ago. With the deterioration of urban traffic conditions, relying on expanding the amount of vehicles and city road network cannot solve the problem. Urban rail transit is energy-saving and less-polluting, uses less space, has large capacity, and secure. Urban rail transit, according to the principle of sustainable development, is a green transportation system and should be especially adopted for large and medium-sized cities. The paper uses the binary choice model (Probit and Logit) to analyze the main factors influencing the development of rail transit in Chinese cities, and whether automobile energy consumption is the reason for the construction of urban rail transit. Secondly, we analyze the influence of urban rail transit on automobile energy consumption using DID model. The results indicate that the construction of urban rail traffic can restrain automobile energy consumption significantly, with continuous impact in the second year. - Highlights: • Investigate the main factors influencing the building of rail transit for Chinese cities. • Analyze the influence of urban rail transit on automobile energy consumption by DID model. • The results indicate that the construction of urban rail traffic can restrain automobile energy consumption significantly.

High-frequency fluctuations of surface temperatures in an urban environment

Science.gov (United States)

Christen, Andreas; Meier, Fred; Scherer, Dieter

2012-04-01

This study presents an attempt to resolve fluctuations in surface temperatures at scales of a few seconds to several minutes using time-sequential thermography (TST) from a ground-based platform. A scheme is presented to decompose a TST dataset into fluctuating, high-frequency, and long-term mean parts. To demonstrate the scheme's application, a set of four TST runs (day/night, leaves-on/leaves-off) recorded from a 125-m-high platform above a complex urban environment in Berlin, Germany is used. Fluctuations in surface temperatures of different urban facets are measured and related to surface properties (material and form) and possible error sources. A number of relationships were found: (1) Surfaces with surface temperatures that were significantly different from air temperature experienced the highest fluctuations. (2) With increasing surface temperature above (below) air temperature, surface temperature fluctuations experienced a stronger negative (positive) skewness. (3) Surface materials with lower thermal admittance (lawns, leaves) showed higher fluctuations than surfaces with high thermal admittance (walls, roads). (4) Surface temperatures of emerged leaves fluctuate more compared to trees in a leaves-off situation. (5) In many cases, observed fluctuations were coherent across several neighboring pixels. The evidence from (1) to (5) suggests that atmospheric turbulence is a significant contributor to fluctuations. The study underlines the potential of using high-frequency thermal remote sensing in energy balance and turbulence studies at complex land-atmosphere interfaces.

Benchmarking urban energy efficiency in the UK

International Nuclear Information System (INIS)

Keirstead, James

2013-01-01

This study asks what is the ‘best’ way to measure urban energy efficiency. There has been recent interest in identifying efficient cities so that best practices can be shared, a process known as benchmarking. Previous studies have used relatively simple metrics that provide limited insight on the complexity of urban energy efficiency and arguably fail to provide a ‘fair’ measure of urban performance. Using a data set of 198 urban UK local administrative units, three methods are compared: ratio measures, regression residuals, and data envelopment analysis. The results show that each method has its own strengths and weaknesses regarding the ease of interpretation, ability to identify outliers and provide consistent rankings. Efficient areas are diverse but are notably found in low income areas of large conurbations such as London, whereas industrial areas are consistently ranked as inefficient. The results highlight the shortcomings of the underlying production-based energy accounts. Ideally urban energy efficiency benchmarks would be built on consumption-based accounts, but interim recommendations are made regarding the use of efficiency measures that improve upon current practice and facilitate wider conversations about what it means for a specific city to be energy-efficient within an interconnected economy. - Highlights: • Benchmarking is a potentially valuable method for improving urban energy performance. • Three different measures of urban energy efficiency are presented for UK cities. • Most efficient areas are diverse but include low-income areas of large conurbations. • Least efficient areas perform industrial activities of national importance. • Improve current practice with grouped per capita metrics or regression residuals

Inter-dependence not Over-dependence: Reducing Urban Transport Energy Dependence

Energy Technology Data Exchange (ETDEWEB)

Saunders, Michael James; Rodrigues da Silva, Antonio Nelson

2007-07-01

A major issue of concern in today's world is urban transport energy dependence and energy supply security. In an energy inter-dependent world, energy over-dependence brings risks to urban transport systems. Many urban areas are over-dependent on finite petroleum resources for transport. New technology and the development and integration of renewable resources into transport energy systems may reduce some of the current transport energy dependence of urban areas. However, the most effective means of reducing energy dependence is to first design urban areas for this condition. An urban policy framework is proposed that requires transport energy dependence to be measured and controlled in the urban development process. A new tool has been created for this purpose, the Transport Energy Specification (TES), which measures transport energy dependence of urban areas. This creates the possibility for cities to regulate urban development with respect to energy dependence. Trial assessments were performed in Germany, New Zealand and Brazil; initial analysis by transport and government professionals shows promise of this tool being included into urban policy. The TES combined with a regulatory framework has the potential to significantly reduce transport energy consumption and dependence in urban areas in the future. (auth)

Open innovation in urban energy systems

Energy Technology Data Exchange (ETDEWEB)

Arnold, M. [Technische Universitaet Muenchen, TUM School of Management, Freising (Germany); Barth, V. [Carl von Ossietzky Universitaet Oldenburg, Ecological Economics, Oldenburg (Germany)

2012-08-15

Despite recent efforts, existing urban energy systems still hardly meet the demands of sustainable development or climate change. Meeting these targets thus will require innovations that use energy much more efficiently and emit far less greenhouse gases. These innovations need to be made on the production as well as the consumption side, on all levels, and need to cover not only technical aspects, but even more service solutions. While many of these solutions still need to be developed, some are already invented but only exist in limited market segments. Opening closed urban planning processes and using open innovation tools can foster bottom-up urban energy system transformation by addressing the interactive ways of decision-making integrating company representatives and citizens. While open innovation tools like (open) innovation workshops or ideas competitions are already used by several companies to find and develop new designs and products, there is yet little experience with energy efficiency ideas and bottom-up changes. Therefore, we analyse energy-efficient ideas generated in three different ideas competitions. We discuss the findings for theory and research on open innovation approaches and bottom-up urban changes. Our results show that there are a vast number of ideas available in the public. Open innovation tools offer advanced possibilities to generate energy-efficient solutions.

Evaluation of the impact of the surrounding urban morphology on building energy consumption

Energy Technology Data Exchange (ETDEWEB)

Wong, Nyuk Hien; Chen, Yixing; Hajadi, Norwin; Sathyanarayanan, Haripriya; Manickavasagam, Yamini Vidya [Department of Building, National University of Singapore (Singapore); Jusuf, Steve Kardinal [Center for Sustainable Asian Cities, National University of Singapore (Singapore); Syafii, Nedyomukti Imam [Institute of High Performance Computing (Singapore)

2011-01-15

Empirical models of minimum (T{sub min}), average (T{sub avg}) and maximum (T{sub max}) air temperature for Singapore estate have been developed and validated based on a long-tem field measurement. There are three major urban elements, which influence the urban temperature at the local scale. Essentially, they are buildings, greenery and pavement. Other related parameters identified for the study, such as green plot ratio (GnPR), sky view factor (SVF), surrounding building density, the wall surface area, pavement area, albedo are also evaluated to give a better understanding on the likely impact of the modified urban morphology on energy consumption. The objective of this research is to assess and to compare how the air temperature variation of urban condition can affect the building energy consumption in tropical climate of Singapore. In order to achieve this goal, a series of numerical calculation and building simulation are utilized. A total of 32 cases, considering different urban morphologies, are identified and evaluated to give better a understanding on the implication of urban forms, with the reference to the effect of varying density, height and greenery density. The results show that GnPR, which related to the present of greenery, have the most significant impact on the energy consumption by reducing the temperature by up to 2 C. The results also strongly indicate an energy saving of 4.5% if the urban elements are addressed effectively. (author)

Provincial energy intensity in China: The role of urbanization

International Nuclear Information System (INIS)

Yan, Huijie

2015-01-01

Chinese policymakers have attached great importance to energy intensity reduction. However, the unprecedented urbanization process exercises additional pressure on the realization of energy intensity reduction targets. A better understanding of the impacts of urbanization is necessary for designing effective policies aimed at reaching the next energy intensity reduction targets. This paper empirically investigates the impacts of urbanization on China's aggregate and disaggregated energy intensities using a balanced panel dataset of 30 provinces covering the period from 2000 to 2012 and panel estimation techniques. The results show that urbanization significantly increases aggregate energy intensity, electricity intensity and coal intensity. - Highlights: • This paper investigates the determinants of China's energy intensity. • Urbanization is responsible for the increase in China's energy intensity. • The fluctuation in China's energy intensity is also affected by other key factors.

Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with TEB model

Science.gov (United States)

Khalifa, A.; Marchetti, M.; Bouilloud, L.; Martin, E.; Bues, M.; Chancibaut, K.

2015-06-01

A forecast of the snowfall helps winter coordination operating services, reducing the cost of the maintenance actions, and the environmental impacts caused by an inappropriate use of de-icing. In order to determine the possible accumulation of snow on pavement, the forecast of the road surface temperature (RST) is mandatory. Physical numerical models provide such forecast, and do need an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB) numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with all the energy interactions, with two approaches to evaluate the traffic incidence on RST. Experiments were then conducted to measure the traffic effect on RST increase with respect to non circulated areas. These field data were then used for comparison with forecast provided by this traffic-implemented TEB version.

Cooling and energy saving potentials of shade trees and urban lawns in a desert city

International Nuclear Information System (INIS)

Wang, Zhi-Hua; Zhao, Xiaoxi; Yang, Jiachuan; Song, Jiyun

2016-01-01

Highlights: • We developed a numerical framework incorporating trees in an urban canopy model. • Shade trees have more prominent energy saving potential than urban lawns. • The trade-off between water-energy is a key for urban landscape management. • Urban vegetation can significantly alleviate outdoor thermal stress. - Abstract: The use of urban vegetation in cities is a common landscape planning strategy to alleviate the heat island effect as well as to enhance building energy efficiency. The presence of trees in street canyons can effectively reduce environmental temperature via radiative shading. However, resolving shade trees in urban land surface models presents a major challenge in numerical models, especially in predicting the radiative heat exchange in canyons. In this paper, we develop a new numerical framework by incorporating shade trees into an advanced single-layer urban canopy model. This novel numerical framework is applied to Phoenix metropolitan area to investigate the cooling effect of different urban vegetation types and their potentials in saving building energy. It is found that the cooling effect by shading from trees is more significant than that by evapotranspiration from lawns, leading to a considerable saving of cooling load. In addition, analysis of human thermal comfort shows that urban vegetation plays a crucial role in creating a comfortable living environment, especially for cities located in arid or semi-arid region.

A systems approach to reduce urban rail energy consumption

International Nuclear Information System (INIS)

González-Gil, A.; Palacin, R.; Batty, P.; Powell, J.P.

2014-01-01

Highlights: • An insightful overview of energy usage in urban rail systems is given. • The principal measures to reduce urban rail energy consumption are appraised. • A methodology is proposed to help implement energy saving schemes in urban rail. • Regenerative braking is shown to offer the greatest energy saving potential. - Abstract: There is increasing interest in the potential of urban rail to reduce the impact of metropolitan transportation due to its high capacity, reliability and absence of local emissions. However, in a context characterised by increasing capacity demands and rising energy costs, and where other transport modes are considerably improving their environmental performance, urban rail must minimise its energy use without affecting its service quality. Urban rail energy consumption is defined by a wide range of interdependent factors; therefore, a system wide perspective is required, rather than focusing on energy savings at subsystem level. This paper contributes to the current literature by proposing an holistic approach to reduce the overall energy consumption of urban rail. Firstly, a general description of this transport mode is given, which includes an assessment of its typical energy breakdown. Secondly, a comprehensive appraisal of the main practices, strategies and technologies currently available to minimise its energy use is provided. These comprise: regenerative braking, energy-efficient driving, traction losses reduction, comfort functions optimisation, energy metering, smart power management and renewable energy micro-generation. Finally, a clear, logical methodology is described to optimally define and implement energy saving schemes in urban rail systems. This includes general guidelines for a qualitative assessment and comparison of measures alongside a discussion on the principal interdependences between them. As a hypothetical example of application, the paper concludes that the energy consumption in existing urban

Sustainable Urban Regeneration Based on Energy Balance

Directory of Open Access Journals (Sweden)

Sacha Silvester

2012-07-01

Full Text Available In this paper, results are reported of a technology assessment of the use and integration of decentralized energy systems and storage devices in an urban renewal area. First the general context of a different approach based on 'rethinking' and the incorporation of ongoing integration of coming economical and environmental interests on infrastructure, in relation to the sustainable urban development and regeneration from the perspective of the tripod people, technology and design is elaborated. However, this is at different scales, starting mainly from the perspective of the urban dynamics. This approach includes a renewed look at the ‘urban metabolism’ and the role of environmental technology, urban ecology and environment behavior focus. Second, the potential benefits of strategic and balanced introduction and use of decentralized devices and electric vehicles (EVs, and attached generation based on renewables are investigated in more detail in the case study of the ‘Merwe-Vierhaven’ area (MW4 in the Rotterdam city port in the Netherlands. In order to optimize the energy balance of this urban renewal area, it is found to be impossible to do this by tuning the energy consumption. It is more effective to change the energy mix and related infrastructures. However, the problem in existing urban areas is that often these areas are restricted to a few energy sources due to lack of available space for integration. Besides this, energy consumption in most cases is relatively concentrated in (existing urban areas. This limits the potential of sustainable urban regeneration based on decentralized systems, because there is no balanced choice regarding the energy mix based on renewables and system optimization. Possible solutions to obtain a balanced energy profile can come from either the choice to not provide all energy locally, or by adding different types of storage devices to the systems. The use of energy balance based on renewables as a

The role of urban form as an energy management parameter

International Nuclear Information System (INIS)

Futcher, Julie Ann; Mills, Gerald

2013-01-01

Urban areas are recognised to be significant global energy consumers, and therefore high CO 2 emitters, making energy management at urban scales a relevant research focus. However, one of the main obstacles faced with upgrading existing urban systems to meet target energy reductions is the current rate of refurbishment and new build, where it is estimated that 75% of existing buildings will still be in place by 2050. Moreover limited renewable resources and predicted warming trends place further limitations on policies aimed at carbon management. This paper examines current thinking around energy management associated with building operational and regulated loads and the role of urban form. Its focus is on cooling loads for office buildings in central London and offers a new perspective on energy management at an urban scale by demonstrating (within the 25% redevelopment rate) that when building energy management is considered within an urban context, the overall performance of an urban system can be significantly improved. The work highlights the often overlooked role of urban form on building energy performance (both individually and in combination) and demonstrates that as we move towards a low energy future; the role of urban form becomes increasing significant. - Highlight: ► The work reports on the energy performance patterns of modern office building groups. ► Mutual shading from adjacent buildings significantly lowers cooling loads. ► Demonstrates the role of urban form as an urban energy management parameter.

Relation Decomposing between Urbanization and Consumption of Water-Energy Sources

Science.gov (United States)

Wang, Y.; Xiao, W.; Wang, Y.; Zhao, Y.; Wang, J., , Dr; Jiang, D.; Wang, H.

2017-12-01

Abstract: Water resources and energy, important subsystems of city, are the basic guarantee for the normal operation of city, which play an important role to brace the urbanization. The interdependence between them are increasing along with the rapid development of China's economy. The relationship between urbanization and consumption of energy and water have become the focal point of the scholars, but the research have more attention to the impact of urbanization on two subsystems separately, and do not reveal the effects of urbanization on the water-energy nexus. Thus, there is little consideration upon the different characteristics of China's several regions in water and energy consumption in urbanization. In this paper, the STIRPAT model is built to reveal the relationship between urbanization and the consumption of water and energy. Also, the influence of urbanization on different main body of water and energy consumption are discussed. The different regional main factors of water and energy in the process of urbanization are identified through water and energy panel data of China's thirty provinces. Finally, through the regression analysis of total water consumption data of agriculture, industry, service industry with total energy consumption data, the relationship of water and energy in the process of urban development are analyzed.

Energy in the urban environment: the role of energy use and energy efficiency in buildings; Final

International Nuclear Information System (INIS)

Levine, Mark D.; Meier, Alan K.

1999-01-01

A century ago, the world had many cities of which the greatest were magnificent centers of culture and commerce. However, even in the most industrialized countries at the time, only a tiny fraction of the people lived in these cities. Most people lived in rural areas, in small towns, in villages, and on farms. Visits to a great city were, for most of the population, uncommon events often of great fascination. The world has changed dramatically in the intervening years. Now most of the industrial world lives in urban areas in close proximity to large cities. Industry is often located in these vast urban areas. As the urbanized zones grow in extent, they begin to approach one another, as on the East Coast of the United States. The phenomenon of urbanization has moved to developing countries as well. There has been a flood of migrants who have left impoverished rural areas to seek economic opportunities in urban areas throughout the developing world. This movement from the countryside to cities has changed the entire landscape and economies of developing nations. Importantly, the growth of cities places very great demands on infrastructure. Transportation systems are needed to assure that a concentrated population can receive food from the countryside without fail. They are needed to assure personal and work-related travel. Water supplies must be created, water must be purified and maintained pure, and this water must be made available to a large population. Medical services - and a host of other vital services - must be provided to the population. Energy is a vital underpinning of all these activities, and must be supplied to the city in large quantities. Energy is, in many ways, the enabler of all the other services on which the maintenance of urban life depends. In this paper, we will discuss the evolution of energy use in residential and commercial buildings. This topic goes beyond urban energy use, as buildings exist in both urban and non-urban areas. The topic

Investigation of the effect of sealed surfaces on local climate in urban areas

Science.gov (United States)

Weihs, Philipp; Hasel, Stefan; Mursch-Radlgruber, Erich; Gützer, Christian; Krispel, Stefan; Peyerl, Martin; Trimmel, Heidi

2015-04-01

Local climate is driven by the interaction between energy balance and energy transported by advected air. Short-wave and long-wave radiation are major components in this interaction. Some few studies (e.g. Santamouris et al.) showed that adjusting the grade of reflection of surfaces is an efficient way to influence temperature. The present study investigates the influence of high albedo concrete surfaces on local climate. The first step of the study consisted of experimental investigations: routine measurements of the short and longwave radiation balance, of the ground and of the air temperature and humidity at different heights above 6 different types of sealed surfaces were performed. During this measurement campaign the above mentioned components were measured over a duration of 4 months above two conventional asphalt surfaces, one conventional concrete and three newly developed concrete surfaces with increased reflectances. Measured albedo values amounted to 0.12±0.02 for the asphalt surfaces and to maximum values of 0.56 for high albedo concrete. The maximum difference in surface temperature between the asphalt surfaces and the high albedo concrete surfaces amounted to 15°C. In addition the emission constants of the different sealed surfaces were also determined and were compared to values from literature.. In a second step the urban energy balance model Envi_Met was used to simulate the surface temperature of the six surfaces. The simulated surface temperatures were compared to the measured surface temperatures and statements as to uncertainties of the model simulations were made In a third step, Envi_Met was used to simulate the local climate of an urban district in Vienna. The surface and air temperature and the SW, LW fluxes were calculated for different types of sealed surfaces. By performing calculations of thermal stress indices (UTCI, PMV), statements as to the influence of the type of sealed surface on thermal stress on humans was made.

City-integrated renewable energy for urban sustainability.

Science.gov (United States)

Kammen, Daniel M; Sunter, Deborah A

2016-05-20

To prepare for an urban influx of 2.5 billion people by 2050, it is critical to create cities that are low-carbon, resilient, and livable. Cities not only contribute to global climate change by emitting the majority of anthropogenic greenhouse gases but also are particularly vulnerable to the effects of climate change and extreme weather. We explore options for establishing sustainable energy systems by reducing energy consumption, particularly in the buildings and transportation sectors, and providing robust, decentralized, and renewable energy sources. Through technical advancements in power density, city-integrated renewable energy will be better suited to satisfy the high-energy demands of growing urban areas. Several economic, technical, behavioral, and political challenges need to be overcome for innovation to improve urban sustainability. Copyright © 2016, American Association for the Advancement of Science.

Issues - I. Renewable energies and urban planning law - Urban planning law and renewable energies: I love you, neither I

International Nuclear Information System (INIS)

Gregory Kalfleche

2012-01-01

After having noticed that fossil energies must still be used beside renewable energies, and that renewable energies have some negative impacts on landscape and on the environment, the author highlights the fact that the French urban planning law gives a strong support to small renewable energy production units. In a second part, he shows that despite a commitment for the development of renewable energies, urban planning law mostly remains a constraint as far as the development of large units is concerned

Urbanism and energy in developing regions

Energy Technology Data Exchange (ETDEWEB)

Meier, R.L.; Berman, S.; Dowell, D.

1978-03-01

The pace of urbanization must continue, because in most parts of the world the surplus population in the countryside has nowhere else to go. The world is about 40% urban now and apparently headed for the 80 to 90% share of the total population presently exhibited by the developed countries. Thus, the 1.6 billion urban dwellers in 1978 would become about 3 billion in 1995--if major catastrophes can be avoided. Feasibility assessments for Sao Paulo-Rio de Janeiro, Calcutta, Cairo-Alexandria, Mexico City, and Seoul are presented in the appendices. This analysis-from-a-distance is insufficient to judge how much extra installed electrical generating capacity is required before 1995, the added refining capability for liquid fuels, or the uses for new LNG and coal imports due to be arranged. It is evident that energy (and perhaps also water in most regions) planning is the major determinant of the manner in which these urban areas will adapt to the extraordinary pressures for new settlement. The current round of planning in such metropolitan areas has been addressed to solving traffic-congestion problems, and reorganizing land use in central districts, as the most-pressing issues. Since energy sources and distribution systems now affect the largest and most crucial investments in urban growth it is to be expected that future metropolitan planning may concentrate upon energy efficiency. Energy supplies must be planned to meet requirements set by locally dominant values regarding human services and the environment.

Urban wind energy. State of the Art 2009

Energy Technology Data Exchange (ETDEWEB)

Beller, C.

2009-10-15

Wind energy in urban areas is a new area and a rather blank page concerning design criteria, aesthetics, concepts, minimizing costs etc. Even though the potential energy in the flow is much higher on the country side or off-shore, the erection of wind turbines in urban areas is carried out and also shows perspectives regarding e. g. direct use of the energy instead of redirecting the energy to the grid and reduction of transmission loss. Within the area of urban wind energy, different applications are to be distinguished. The main groups are turbines integrated in buildings, small turbines on already existing buildings and free standing turbines in public areas. In this report, a look is taken on the mentioned applications, a short introduction to urban climate is given, followed by a list of already existing small turbines which are compared. Examples in between, field tests and experiments support the understanding. An overview of current projects set the application of wind turbines in the urban environment in a relevant perspective. (author)

Scenarios for a urban energy transition. Actors, regulations, technologies

International Nuclear Information System (INIS)

Debizet, Gilles; Blanco, Sylvie; Buclet, Nicolas; Forest, Fabrice; Gauthier, Caroline; La Branche, Stephane; Menanteau, Philippe; Schneuwly, Patrice; Tabourdeau, Antoine

2016-01-01

Cities concentrate populations, consumptions, levers of actions, and are places of various experiments for energy transition. This book aims at giving an overview of possible scenarios of development of renewable energies in urban context. It is based on interviews of actors of the energy, building and urban planning sectors by researchers in town planning, management, technology, political and economic sciences. The authors examine what would occur if large companies would manage entire quarters, if local authorities would supervise production and supply, if the State would take control of all fields of action again, or if consumer cooperatives would exchange energy and pool productions. In its different chapters, the book presents four scenarios of energy coordination in urban context by 2040, discuss energy transition in urban spaces, discuss the perspectives of evolution towards more autonomous cities and quarters from an energetic point of view, and discuss business models and urban energetic innovations

An urban energy performance evaluation system and its computer implementation.

Science.gov (United States)

Wang, Lei; Yuan, Guan; Long, Ruyin; Chen, Hong

2017-12-15

To improve the urban environment and effectively reflect and promote urban energy performance, an urban energy performance evaluation system was constructed, thereby strengthening urban environmental management capabilities. From the perspectives of internalization and externalization, a framework of evaluation indicators and key factors that determine urban energy performance and explore the reasons for differences in performance was proposed according to established theory and previous studies. Using the improved stochastic frontier analysis method, an urban energy performance evaluation and factor analysis model was built that brings performance evaluation and factor analysis into the same stage for study. According to data obtained for the Chinese provincial capitals from 2004 to 2013, the coefficients of the evaluation indicators and key factors were calculated by the urban energy performance evaluation and factor analysis model. These coefficients were then used to compile the program file. The urban energy performance evaluation system developed in this study was designed in three parts: a database, a distributed component server, and a human-machine interface. Its functions were designed as login, addition, edit, input, calculation, analysis, comparison, inquiry, and export. On the basis of these contents, an urban energy performance evaluation system was developed using Microsoft Visual Studio .NET 2015. The system can effectively reflect the status of and any changes in urban energy performance. Beijing was considered as an example to conduct an empirical study, which further verified the applicability and convenience of this evaluation system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measure for Measure: Urban Water and Energy

Science.gov (United States)

Chini, C.; Stillwell, A. S.

2017-12-01

Urban environments in the United States account for a majority of the population and, as such, require large volumes of treated drinking water supply and wastewater removal, both of which need energy. Despite the large share of water that urban environments demand, there is limited accounting of these water resources outside of the city itself. In this study, we provide and analyze a database of drinking water and wastewater utility flows and energy that comprise anthropogenic fluxes of water through the urban environment. We present statistical analyses of the database at an annual, spatial, and intra-annual scale. The average daily per person water flux is estimated as 563 liters of drinking water and 496 liters of wastewater, requiring 340 kWh/1000 m3 and 430 kWh/1000 m3 of energy, respectively, to treat these resources. This energy demand accounts for 1% of the total annual electricity production of the United States. Additionally, the water and embedded energy loss associated with non-revenue water (estimated at 15.8% annually) accounts for 9.1 km3of water and 3600 GWh, enough electricity to power 300,000 U.S. households annually. Through the analysis and benchmarking of the current state of urban water fluxes, we propose the term `blue city,' which promotes urban sustainability and conservation policy focusing on water resources. As the nation's water resources become scarcer and more unpredictable, it is essential to include water resources in urban sustainability planning and continue data collection of these vital resources.

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

Science.gov (United States)

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

Modeling The Urban Impact On Semiarid Surface Climate: A Case Study In Marrakesh, Morocco

Science.gov (United States)

Lachir, Asia; Bounoua, Lahouari; Zhang, Ping; Thome, Kurtis; Messouli, Mohamed

2016-01-01

We combine Landsat and MODIS data in the Simple Biosphere Model to assess the impact of urbanization on surface climate in a semiarid city in North Africa. The model simulates highest temperatures in urban class, with spring average maximum temperature differences to other land cover classes ranging between 1.6 C and 6.0 C. During summer, these maximum temperature differences are smallest (0.5 C) with barelands and highest (8.3 C) with irrigated lawns. This excess heating is simulated above and beyond a seasonal temperature average of about 30 C during spring and 44 C during summer. On annual mean, a full urbanization scenario decreases the carbon fixation by 0.13 MtC and increases the daytime mean surface temperature by 1.3 C. This may boost the city energy consumption by 5.72%. Under a 'smart growth' scenario, whereby the city expands on barelands to cover 50% of the study region and all remaining barelands converted to orchards, the carbon fixation is enhanced by 0.04 MtC with a small daytime temperature increase of 0.2 C. Our results indicate that vegetation can mitigate the urban heating. The hydrological cycle indicates that highest ratio of surface runoff to precipitation (43.8%) occurs in urban areas, versus only 16.7 % for all cover types combined.

Modeling the Urban Impact on Semiarid Surface Climate: A Case Study in Marrakech, Morocco

Science.gov (United States)

Lachir, Asia; Bounoua, Lahouari; Zhang, Ping; Thome, Kurtis; Moussouli, Mohamed

2016-01-01

We combine Landsat and MODIS data in the Simple Biosphere Model to assess the impact of urbanization on surface climate in a semiarid city in North Africa. The model simulates highest temperatures in urban class, with spring average maximum temperature differences to other land cover classes ranging between 1.6 C and 6.0 C. During summer, these maximum temperature differences are smallest (0.5 C) with barelands and highest (8.3 C) with irrigated lawns. This excess heating is simulated above and beyond a seasonal temperature average of about 30 C during spring and 44 C during summer. On annual mean, a full urbanization scenario decreases the carbon fixation by 0.13 MtC and increases the daytime mean surface temperature by 1.3 C. This may boost the city energy consumption by 5.72%. Under a 'smart growth' scenario, whereby the city expands on barelands to cover 50% of the study region and all remaining barelands converted to orchards, the carbon fixation is enhanced by 0.04 MtC with a small daytime temperature increase of 0.2 C. Our results indicate that vegetation can mitigate the urban heating. The hydrological cycle indicates that highest ratio of surface runoff to precipitation (43.8%) occurs in urban areas, versus only 16.7 % for all cover types combined.

A model for predicting the potential diffusion of solar energy systems in complex urban environments

International Nuclear Information System (INIS)

La Gennusa, Maria; Lascari, Giovanni; Rizzo, Gianfranco; Scaccianoce, Gianluca; Sorrentino, Giancarlo

2011-01-01

The necessity to reduce greenhouse gases emission produced by energy building consumptions and to cut the energy bill (mainly due to the use of fossil sources) leads to the employment of renewable energy sources in new planned scenarios. In particular, more and more often municipal energy and environmental plans pay great attention to the possibilities of employment of the solar technologies at urban scale. Solar thermal and photovoltaic (PV) systems are, by far, the most suitable tools to be utilized in urban areas. Obviously, the proper adoption of such systems in buildings does call for the availability of calculation methods suitable to provide the actual level of exploitation of solar energy in urban layouts. In this work, a procedure for evaluating the geographical energy potential of building roofs in urban areas is proposed; in particular, the amount of surface on the roof that could be used for the installation of systems able to capture solar radiation for the energy production is investigated. The proposed procedure is based on the use of the GIS technology and 3D cartography. The effectiveness of the proposed method is assessed by means of an application to the town of Palermo (Italy). - Highlights: → The GIS techniques allow to analyze various future scenarios about urban planning. → We propose a procedure for assessing the extension of superficial urban areas useable for the installation of solar systems. → This procedure allow to compile a scale of priority of intervention. → The cost for financing such interventions is compared to the penalty to pay for not achieving the Kyoto goals.

Alleviating Urban Energy Poverty in Latin America

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-02-15

This regional study is comprised of three case studies, which concentrate on Greater Buenos Aires, Caracas and Rio de Janeiro - Caju. Each case focuses on the analysis of specific aspects of urban poverty, energy availability and policies to improve living conditions from the energy point of view. Unlike other developing regions in the world, the problem of energy poverty in Latin America has been concentrated increasingly in the large cities and urban areas. This problem has deep systemic, economic, political, structural and cultural roots. Providing basic energy services to the urban poor is an issue that requires far more attention and expertise than it is receiving today, and therefore WEC has taken the initiative to address this issue, and the results of their study are presented in this report.

Visions of sustainable urban energy systems. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Pietzsch, Ursula [HFT Stuttgart (Germany). zafh.net - Centre of Applied Research - Sustainable Energy Technology; Mikosch, Milena [Steinbeis-Zentrum, Stuttgart (Germany). Europaeischer Technologietransfer; Liesner, Lisa (eds.)

2010-09-15

Within the polycity final conference from 15th to 17th September, 2010, in Stuttgart (Federal Republic of Germany) the following lectures were held: (1) Visions of sustainable urban energy system (Ursula Eicker); (2) Words of welcome (Tanja Goenner); (3) Zero-energy Europe - We are on our way (Jean-Marie Bemtgen); (4) Polycity - Energy networks in sustainable cities An introduction (Ursula Pietzsch); (5) Energy efficient city - Successful examples in the European concerto initiative (Brigitte Bach); (6) Sustainable building and urban concepts in the Catalonian polycity project contributions to the polycity final conference 2010 (Nuria Pedrals); (7) Energy efficient buildings and renewable supply within the German polycity project (Ursula Eicker); (8) Energy efficient buildings and cities in the US (Thomas Spiegehalter); (9) Energy efficient communities - First results from an IEA collaboration project (Reinhard Jank); (10) The European energy performance of buildings directive (EPBD) - Lessons learned (Eduardo Maldonado); (11) Passive house standard in Europe - State-of-the-art and challenges (Wolfgang Feist); (12) High efficiency non-residential buildings: Concepts, implementations and experiences from the UK (Levin Lomas); (13) This is how we can save our world (Franz Alt); (14) Green buildings and renewable heating and cooling concepts in China (Yanjun Dai); (15) Sustainable urban energy solutions for Asia (Brahmanand Mohanty); (16) Description of ''Parc de l'Alba'' polygeneration system: A large-scale trigeneration system with district heating within the Spanish polycity project (Francesc Figueras Bellot); (17) Improved building automation and control systems with hardware-in-the loop solutions (Martin Becker); (18) The Italian polycity project area: Arquata (Luigi Fazari); (19) Photovoltaic system integration: In rehabilitated urban structures: Experiences and performance results from the Italian polycity project in Turin (Franco

Dry deposition on urban surfaces

International Nuclear Information System (INIS)

Roed, J.

1985-01-01

In order to facilitate developing a model for deposition in urban areas, beryllium-7, created by cosmic radiation and fall-out cesium-137, have been used as tracers in measurements designed to find the dry deposition velocity on building surfaces. A literature review has revealed that very little work has been done on deposition in urban areas; therefore, a major effort on meausring the deposition parameter is needed to construct reliable models in this field. Deposition velocities in the range from 0.001-0.04 cm/s have been found. (author)

Managing the urban water-energy nexus

Science.gov (United States)

Escriva-Bou, Alvar; Pulido-Velazquez, Manuel; Lund, Jay R.

2016-04-01

Water use directly causes a significant amount of energy use in cities. In this paper we assess energy and greenhouse emissions related with each part of the urban water cycle and the consequences of several changes in residential water use for customers, water and energy utilities, and the environment. First, we develop an hourly model of urban water uses by customer category including water-related energy consumption. Next, using real data from East Bay Municipal Utility District in California, we calibrate a model of the energy used in water supply, treatment, pumping and wastewater treatment by the utility. Then, using data from the California Independent System Operator, we obtain hourly costs of energy for the energy utility. Finally, and using emission factors reported by the energy utilities we estimate greenhouse gas emissions for the entire urban water cycle. Results of the business-as-usual scenario show that water end uses account for almost 95% of all water-related energy use, but the 5% managed by the utility is still worth over 12 million annually. Several simulations analyze the potential benefits for water demand management actions showing that moving some water end-uses from peak to off-peak hours such as outdoor use, dishwasher or clothes washer use have large benefits for water and energy utilities, especially for locations with a high proportion of electric water heaters. Other interesting result is that under the current energy rate structures with low or no fixed charges, energy utilities burden most of the cost of the conservation actions.

Eight energy and material flow characteristics of urban ecosystems.

Science.gov (United States)

Bai, Xuemei

2016-11-01

Recent decades have seen an expanding literature exploring urban energy and material flows, loosely branded as urban metabolism analysis. However, this has occurred largely in parallel to the mainstream studies of cities as ecosystems. This paper aims to conceptually bridge these two distinctive fields of research, by (a) identifying the common aspects between them; (b) identifying key characteristics of urban ecosystems that can be derived from energy and material flow analysis, namely energy and material budget and pathways; flow intensity; energy and material efficiency; rate of resource depletion, accumulation and transformation; self-sufficiency or external dependency; intra-system heterogeneity; intersystem and temporal variation; and regulating mechanism and governing capacity. I argue that significant ecological insight can be, or has the potential to be, drawn from the rich and rapidly growing empirical findings of urban metabolism studies to understand the behaviour of cities as human-dominated, complex systems. A closer intellectual linkage and cross pollination between urban metabolism and urban ecosystem studies will advance our scientific understanding and better inform urban policy and management practices.

Thermal Characteristics of Urban Landscapes

Science.gov (United States)

Luvall, Jeffrey C.; Quattrochi, Dale A.

1998-01-01

Although satellite data are very useful for analysis of the urban heat island effect at a coarse scale, they do not lend themselves to developing a better understanding of which surfaces across the city contribute or drive the development of the urban heat island effect. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., less than 15 m) to adequately resolve these surfaces and their attendant thermal energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace the benefits of the urban forest. These benefits include mitigating the urban heat island effect, making cities more aesthetically pleasing and more habitable environments, and aid in overall cooling of the community. High spatial resolution thermal data are required to quantify how artificial surfaces within the city contribute to an increase in urban heating and the benefit of cool surfaces (e.g., surface coatings that reflect much of the incoming solar radiation as opposed to absorbing it thereby lowering urban temperatures). The TRN (thermal response number) is a technique using aircraft remotely sensed surface temperatures to quantify the thermal response of urban surfaces. The TRN was used to quantify the thermal response of various urban surface types ranging from completely vegetated surfaces to asphalt and concrete parking lots for Huntsville, AL.

The relevance of rooftops: Analyzing the microscale surface energy balance in the Chicago region

Science.gov (United States)

Khosla, Radhika

Spatial structure in climate variables often exist over very short length scales within an urban area, and this structure is a result of various site-specific features. In order to analyze the seasonal and diurnal energy flows that take place at a microclimatic surface, this work develops a semi-empirical energy balance model. For this, radiation fluxes and meteorological measurements are determined by direct observation; sensible heat and latent heat fluxes by parameterizations; and the heat storage flux by a 1-D mechanistic model that allows analysis of the temperature profile and heat storage within an underlying slab. Two sites receive detailed study: an anthropogenic site, being a University of Chicago building rooftop, and a natural site, outside Chicago in the open country. Two identical sets of instruments record measurements contemporaneously from these locations during June-November 2007, the entire period for which analyses are carried out. The study yields seasonal trends in surface temperature, surface-to-air temperature contrast and net radiation. At both sites, a temporal hysteresis between net radiation and heat storage flux indicates that surplus energy absorbed during daylight is released to the atmosphere later in the evening. The surface energy balance model responds well to site specific features for both locations. An analysis of the surface energy balance shows that the flux of sensible heat is the largest non-radiative contributor to the roof's surface cooling, while the flux of latent heat (also referred to as evaporative cooling) is the largest heat sink for the soil layer. In the latter part of the study, the surface energy balance model is upgraded by adding the capability to compute changes in surface temperature and non-radiative fluxes for any specified set of thermal and reflective roof properties. The results of this analysis allow an examination of the relationship between the roof temperature, the heat flux entering the building

Urban Planners with Renewable Energy Skills

Directory of Open Access Journals (Sweden)

Arto Emerik Nuorkivi

2013-06-01

Full Text Available There is no much tradition to combine urban and energy planning together to fight Climate Change even though energy production with fossil fuels is the main cause to the Change. Pilot training of urban planners in five EU countries such Finland, Germany, Hungary, Spain and the United Kingdom to understand the basics of renewable energy sources (RES and energy efficiency (EE has been carried out during 2011-2012 under co-financing of Intelligent Energy Europe. Organizing such pilot training was challenging for many reasons, but the outcome can be consdered highly statisfactory, based on the recorded feedback of trainees and other stakeholders. The project encourages other planning schools in Europe to learn from the experience and to use the published training materials available in ten languages in their curricula.

Remote Sensing of Atlanta's Urban Sprawl and the Distribution of Land Cover and Surface Temperature

Science.gov (United States)

Laymon, Charles A.; Estes, Maurice G., Jr.; Quattrochi, Dale A.; Goodman, H. Michael (Technical Monitor)

2001-01-01

Between 1973 and 1992, an average of 20 ha of forest was lost each day to urban expansion of Atlanta, Georgia. Urban surfaces have very different thermal properties than natural surfaces-storing solar energy throughout the day and continuing to release it as sensible heat well after sunset. The resulting heat island effect serves as catalysts for chemical reactions from vehicular exhaust and industrialization leading to a deterioration in air quality. In this study, high spatial resolution multispectral remote sensing data has been used to characterize the type, thermal properties, and distribution of land surface materials throughout the Atlanta metropolitan area. Ten-meter data were acquired with the Advanced Thermal and Land Applications Sensor (ATLAS) on May 11 and 12, 1997. ATLAS is a 15-channel multispectral scanner that incorporates the Landsat TM bands with additional bands in the middle reflective infrared and thermal infrared range. The high spatial resolution permitted discrimination of discrete surface types (e.g., concrete, asphalt), individual structures (e.g., buildings, houses) and their associated thermal characteristics. There is a strong temperature contrast between vegetation and anthropomorphic features. Vegetation has a modal temperature at about 20 C, whereas asphalt shingles, pavement, and buildings have a modal temperature of about 39 C. Broad-leaf vegetation classes are indistinguishable on a thermal basis alone. There is slightly more variability (+/-5 C) among the urban surfaces. Grasses, mixed vegetation and mixed urban surfaces are intermediate in temperature and are characterized by broader temperature distributions with modes of about 29 C. Thermal maps serve as a basis for understanding the distribution of "hotspots", i.e., how landscape features and urban fabric contribute the most heat to the lower atmosphere.

The urban canyon and building energy use: Urban density versus daylight and passive solar gains

DEFF Research Database (Denmark)

Strømann-Andersen, Jakob Bjørn; Sattrup, Peter Andreas

2011-01-01

.It was found that the geometry of urban canyons has an impact on total energy consumption in the range of up to +30% for offices and +19% for housing, which shows that the geometry of urban canyons is a key factor in energy use in buildings. It was demonstrated how the reflectivity of urban canyons plays...

The surface urban heat island response to urban expansion: A panel analysis for the conterminous United States

Energy Technology Data Exchange (ETDEWEB)

Li, Xiaoma; Zhou, Yuyu; Asrar, Ghassem R.; Imhoff, Marc; Li, Xuecao

2017-12-01

Abstract: Urban heat island (UHI), a major concern worldwide, affects human health and energy use. With current and anticipated rapid urbanization, improved understanding of the response of UHI to urbanization is important for impact analysis and developing effective adaptation measures and mitigation strategies. Current studies mainly focus on a single or a few big cities and knowledge on the response of UHI to urbanization for large areas is very limited. Modelling UHI caused by urbanization for large areas that encompass multiple metropolitans remains a major scientific challenge/opportunity. As a major indicator of urbanization, urban area size lends itself well for representation in prognostic models to investigate the impacts of urbanization on UHI and the related socioeconomic and environmental effects. However, we have little knowledge on how UHI responds to the increase of urban area size, namely urban expansion, and its spatial and temporal variation over large areas. In this study, we investigated the relationship between surface UHI (SUHI) and urban area size in the climate and ecological context, and its spatial and temporal variations, based on a panel analysis of about 5000 urban areas of 10 km2 or larger, in the conterminous U.S. We found statistically significant positive relationship between SUHI and urban area size, and doubling the urban area size led to a SUHI increase of higher than 0.7 °C. The response of SUHI to the increase of urban area size shows spatial and temporal variations, with stronger SUHI increase in the Northern region of U.S., and during daytime and summer. Urban area size alone can explain as much as 87% of the variance of SUHI among cities studied, but with large spatial and temporal variations. Urban area size shows higher association with SUHI in regions where the thermal characteristics of land cover surrounding the urban are more homogeneous, such as in Eastern U.S., and in the summer months. This study provides a

PALM-USM v1.0: A new urban surface model integrated into the PALM large-eddy simulation model

Directory of Open Access Journals (Sweden)

J. Resler

2017-10-01

Full Text Available Urban areas are an important part of the climate system and many aspects of urban climate have direct effects on human health and living conditions. This implies that reliable tools for local urban climate studies supporting sustainable urban planning are needed. However, a realistic implementation of urban canopy processes still poses a serious challenge for weather and climate modelling for the current generation of numerical models. To address this demand, a new urban surface model (USM, describing the surface energy processes for urban environments, was developed and integrated as a module into the PALM large-eddy simulation model. The development of the presented first version of the USM originated from modelling the urban heat island during summer heat wave episodes and thus implements primarily processes important in such conditions. The USM contains a multi-reflection radiation model for shortwave and longwave radiation with an integrated model of absorption of radiation by resolved plant canopy (i.e. trees, shrubs. Furthermore, it consists of an energy balance solver for horizontal and vertical impervious surfaces, and thermal diffusion in ground, wall, and roof materials, and it includes a simple model for the consideration of anthropogenic heat sources. The USM was parallelized using the standard Message Passing Interface and performance testing demonstrates that the computational costs of the USM are reasonable on typical clusters for the tested configurations. The module was fully integrated into PALM and is available via its online repository under the GNU General Public License (GPL. The USM was tested on a summer heat-wave episode for a selected Prague crossroads. The general representation of the urban boundary layer and patterns of surface temperatures of various surface types (walls, pavement are in good agreement with in situ observations made in Prague. Additional simulations were performed in order to assess the

Energy Efficiency and Urban Renewal in the Economies in Transition

International Nuclear Information System (INIS)

Brendow, K.

1997-01-01

The Paper notes the importance of energy consumption in agglomerations (65-70% in the economies in transition) and of related emissions. It assesses the technical and cost-effective potential for a 40% and more decrease in urban energy intensities and SO 2 /NO x emissions by 2020, resulting from a systematic approach to urban as well as energy planning. Compared to approaches worldwide, urban energy renewal in the economies in transition appears, as its beginning, characterized by a traditional focus on existing technological supply sub-systems such as district heating and co-generation. The obstacles to a more systematic approach, including demand side management, are slow progress in urban and energy reforms and a lack of acquaintance with modern planning tools. International cooperation is incommensurate with the long-term challenge of s ustainable urban development . (author)

Remote Sensing of Atlanta's Urban Sprawl and the Distribution of Land Cover and Surface Temperatures

Science.gov (United States)

Laymon, Charles A.; Estes, Maurice G., Jr.; Quattrochi, Dale A.; Arnold, James E. (Technical Monitor)

2001-01-01

Between 1973 and 1992, an average of 20 ha of forest was lost each day to urban expansion of Atlanta, Georgia. Urban surfaces have very different thermal properties than natural surfaces-storing solar energy throughout the day and continuing to release it as sensible heat well after sunset. The resulting heat island effect serves as catalysts for chemical reactions from vehicular exhaust and industrialization leading to a deterioration in air quality. In this study, high spatial resolution multispectral remote sensing data has been used to characterize the type, thermal properties, and distribution of land surface materials throughout the Atlanta metropolitan area. Ten-meter data were acquired with the Advanced Thermal and Land Applications Sensor (ATLAS) on May 11 and 12, 1997. ATLAS is a 15-channel multispectral scanner that incorporates the Landsat TM bands with additional bands in the middle reflective infrared and thermal infrared range. The high spatial resolution permitted discrimination of discrete surface types (e.g., concrete, asphalt), individual structures (e.g., buildings, houses) and their associated thermal characteristics. There is a strong temperature contrast between vegetation and anthropomorphic features. Vegetation has a modal temperature at about 20 C, whereas asphalt shingles, pavement, and buildings have a modal temperature of about 39 C. Broad-leaf vegetation classes are indistinguishable on a thermal basis alone. There is slightly more variability (plus or minus 5 C) among the urban surfaces. Grasses, mixed vegetation and mixed urban surfaces are intermediate in temperature and are characterized by broader temperature distributions with modes of about 29 C. Thermal maps serve as a basis for understanding the distribution of "hotspots", i.e., how landscape features and urban fabric contribute the most heat to the lower atmosphere.

Quantifying Water and Energy Fluxes Over Different Urban Land Covers in Phoenix, Arizona

Science.gov (United States)

Templeton, Nicole P.; Vivoni, Enrique R.; Wang, Zhi-Hua; Schreiner-McGraw, Adam P.

2018-02-01

The impact of urbanization on water and energy fluxes varies according to the characteristics of the urban patch type. Nevertheless, urban flux observations are limited, particularly in arid climates, given the wide variety of land cover present in cities. To help address this need, a mobile eddy covariance tower was deployed at three locations in Phoenix, Arizona, to sample the surface energy balance at a parking lot, a xeric landscaping (irrigated trees with gravel) and a mesic landscaping (irrigated turf grass). These deployments were compared to a stationary eddy covariance tower in a suburban neighborhood. A comparison of the observations revealed key differences between the mobile and reference sites tied to the urban land cover within the measurement footprints. For instance, the net radiation varied substantially among the sites in manners consistent with albedo and shallow soil temperature differences. The partitioning of available energy between sensible and latent heat fluxes was modulated strongly by the presence of outdoor water use, with the irrigated turf grass exhibiting the highest evaporative fraction. At this site, we identified a lack of sensitivity of turbulent flux partitioning to precipitation events, which suggests that frequent outdoor water use removes water limitations in an arid climate, thus leading to mesic conditions. Other urban land covers with less irrigation, however, exhibited sensitivity to the occurrence of precipitation, as expected for an arid climate. As a result, quantifying the frequency and magnitude of outdoor water use is critical for understanding evapotranspiration losses in arid urban areas.

Urban transport energy consumption: Belgrade case study

Directory of Open Access Journals (Sweden)

Jovanović Miomir M.

2015-01-01

Full Text Available More than half of the global population now lives in towns and cities. At the same time, transport has become the highest single energy-consuming human activity. Hence, one of the major topics today is the reduction of urban transport demand and of energy consumption in cities. In this article we focused on the whole package of instruments that can reduce energy consumption and transport demand in Belgrade, a city that is currently at a major crossroad. Belgrade can prevent a dramatic increase in energy consumption and CO2 emissions (and mitigate the negative local environmental effects of traffic congestion, traffic accidents and air pollution, only if it: 1 implements a more decisive strategy to limit private vehicles use while its level of car passenger km (PKT is still relatively low; 2 does not try to solve its transport problems only by trying to build urban road infrastructure (bridges and ring roads; and 3 if it continues to provide priority movement for buses (a dominant form of public transport, while 4 at the same time developing urban rail systems (metro or LRT with exclusive tracks, immune to the traffic congestion on urban streets. [Projekat Ministarstva nauke Republike Srbije, br. 37010

Urban Wind Energy - State of the Art 2009

DEFF Research Database (Denmark)

Beller, Christina

Wind energy in urban areas is a new area and a rather blank page concerning design criteria, aesthetics, concepts, minimizing costs etc. Even though the potential energy in the flow is much higher on the country side or off-shore, the erection of wind turbines in urban areas is carried out and also...

Analysing urban planning implications from an electric vehicles scenario for urban structure-, transport- and energy-systems

Energy Technology Data Exchange (ETDEWEB)

Rid, Wolfgang [Stuttgart Univ. (Germany). Lehrstuhl Stadtplanung und Entwerfen; Fachhochschule Erfurt (Germany). Fachgebiet Stadt- und Regionaloekonomie; Pesch, Franz; Wewer, Max; Sperle, Tilman [Stuttgart Univ. (Germany). Lehrstuhl Stadtplanung und Entwerfen

2013-06-01

Depending on scenarios of actual electric vehicles on the road, ''electric mobility'' will heavily affect urban planning and infrastructure. We analyze these effects by developing an ''urban typology for electro-mobility''. By doing so, we seek to demonstrate that both requirements from electric vehicle scenarios (infrastructure, on-site provision of renewable energy etc.) and potential benefits (noise-reduction, NOx-reduction, modal-split etc.) are dependent on the urban context. The typology was developed according to preliminary studies' results recommending to use the GFZ (Gross Floor Area) and residential density to describe different types of urban structure, but additionally makes use of the proportion of public space and number of resident families (per ha net residential area) to extract five different ''urban types for electro-mobility''. Electro-mobility will have a significant climate effect only if 'green' electric power production is able to provide the additional amount of renewable energy needed. On-site power plants must be further developed to reduce externalities from large scale power plants providing C02-free energy (e.g. externalities from offshore wind energy plants). The potential to produce renewable energy from on-site power plants is dependent on the type of the urban context: Advanced ''plus-energy-concepts'' for example, today, are restricted to building scales of low-density residential zones, whereas in inner city zones, buildings have to provide energy for far more people per floorspace or for cooling purposes, as well. On-site renewable energy plants should be placed in urban settings, where they can work most efficiently and where they can be best integrated into the urban context given, hence, electro-mobility needs to be viewed from an urban perspective. Many other projects, so far, have investigated technical solutions to improve

Urban and energy planning in Santiago de Compostela : Final Report

NARCIS (Netherlands)

Fernandez Maldonado, A.M.

2015-01-01

The purpose of Deliverable 4.2 is to give an overview of urban energy planning in the six PLEEC partner cities. The six reports illustrate how cities deal with different challenges of the urban energy transformation from a structural perspective including issues of urban governance and spatial

URBAN EFFICIENT ENERGY EVALUATION IN HIGH RESOLUTION URBAN AREAS BY USING ADAPTED WRF-UCM AND MICROSYS CFD MODELS

Science.gov (United States)

San Jose, R.; Perez, J. L.; Gonzalez, R. M.

2009-12-01

Urban metabolism modeling has advanced substantially during the last years due to the increased detail in mesoscale urban parameterization in meteorological mesoscale models and CFD numerical tools. Recently the implementation of the “urban canopy model” (UCM) into the WRF mesoscale meteorological model has produced a substantial advance on the understanding of the urban atmospheric heat flux exchanges in the urban canopy. The need to optimize the use of heat energy in urban environment has produced a substantial increase in the detailed investigation of the urban heat flux exchanges. In this contribution we will show the performance of using a tool called MICROSYS (MICRO scale CFD modelling SYStem) which is an adaptation of the classical urban canopy model but on a high resolution environment by using a classical CFD approach. The energy balance in the urban system can be determined in a micrometeorologicl sense by considering the energy flows in and out of a control volume. For such a control volume reaching from ground to a certain height above buildings, the energy balance equation includes the net radiation, the anthropogenic heat flux, the turbulent sensible heat flux, the turbulent latent heat flux, the net storage change within the control volume, the net advected flux and other sources and sinks. We have applied the MICROSYS model to an area of 5 km x 5 km with 200 m spatial resolution by using the WRF-UCM (adapted and the MICROSYS CFD model. The anthropogenic heat flux has been estimated by using the Flanner M.G. (2009) database and detailed GIS information (50 m resolution) of Madrid city. The Storage energy has been estimated by calculating the energy balance according to the UCM procedure and implementing it into the MICROSYS tool. Results show that MICROSYS can be used as an energy efficient tool to estimate the energy balance of different urban areas and buildings.

Evaluation of the WRF-Urban Modeling System Coupled to Noah and Noah-MP Land Surface Models Over a Semiarid Urban Environment

Science.gov (United States)

Salamanca, Francisco; Zhang, Yizhou; Barlage, Michael; Chen, Fei; Mahalov, Alex; Miao, Shiguang

2018-03-01

We have augmented the existing capabilities of the integrated Weather Research and Forecasting (WRF)-urban modeling system by coupling three urban canopy models (UCMs) available in the WRF model with the new community Noah with multiparameterization options (Noah-MP) land surface model (LSM). The WRF-urban modeling system's performance has been evaluated by conducting six numerical experiments at high spatial resolution (1 km horizontal grid spacing) during a 15 day clear-sky summertime period for a semiarid urban environment. To assess the relative importance of representing urban surfaces, three different urban parameterizations are used with the Noah and Noah-MP LSMs, respectively, over the two major cities of Arizona: Phoenix and Tucson metropolitan areas. Our results demonstrate that Noah-MP reproduces somewhat better than Noah the daily evolution of surface skin temperature and near-surface air temperature (especially nighttime temperature) and wind speed. Concerning the urban areas, bulk urban parameterization overestimates nighttime 2 m air temperature compared to the single-layer and multilayer UCMs that reproduce more accurately the daily evolution of near-surface air temperature. Regarding near-surface wind speed, only the multilayer UCM was able to reproduce realistically the daily evolution of wind speed, although maximum winds were slightly overestimated, while both the single-layer and bulk urban parameterizations overestimated wind speed considerably. Based on these results, this paper demonstrates that the new community Noah-MP LSM coupled to an UCM is a promising physics-based predictive modeling tool for urban applications.

Nested High Resolution Modeling of the Impact of Urbanization on Regional Climate in Three Vast Urban Agglomerations in China

Science.gov (United States)

Wang, Jun; Feng, Jinming; Yan, Zhongwei; Hu, Yonghong; Jia, Gensuo

2013-04-01

In this paper, the Weather Research and Forecasting (WRF) model coupled to the Urban Canopy Model (UCM) is employed to simulate the impact of urbanization on the regional climate over three vast city agglomerations in China. Based on high resolution land use and land cover data, two scenarios are designed to represent the non-urban and current urban land use distributions. By comparing the results of two nested, high resolution numerical experiments, the spatial and temporal changes on surface air temperature, heat stress index, surface energy budget and precipitation due to urbanization are analyzed and quantified. Urban expansion increases the surface air temperature in urban areas by about 1? and this climatic forcing of urbanization on temperature is more pronounced in summer and nighttime than other seasons and daytime. The heat stress intensity, which reflects the combined effects of temperature and humidity, is enhanced by about 0.5 units in urban areas. The regional incoming solar radiation increases after urban expansion, which may be caused by the reduction of cloud fraction. The increased temperature and roughness of the urban surface lead to enhanced convergence. Meanwhile, the planetary boundary layer is deepened and water vapor is mixed more evenly in the lower atmosphere. The deficit of water vapor leads to less convective available potential energy and more convective inhibition energy. Finally, these combined effects may reduce the rainfall amount over urban area mainly in summer and change the regional precipitation pattern to a certain extent.

Urban energy consumption: Different insights from energy flow analysis, input–output analysis and ecological network analysis

International Nuclear Information System (INIS)

Chen, Shaoqing; Chen, Bin

2015-01-01

Highlights: • Urban energy consumption was assessed from three different perspectives. • A new concept called controlled energy was developed from network analysis. • Embodied energy and controlled energy consumption of Beijing were compared. • The integration of all three perspectives will elucidate sustainable energy use. - Abstract: Energy consumption has always been a central issue for sustainable urban assessment and planning. Different forms of energy analysis can provide various insights for energy policy making. This paper brought together three approaches for energy consumption accounting, i.e., energy flow analysis (EFA), input–output analysis (IOA) and ecological network analysis (ENA), and compared their different perspectives and the policy implications for urban energy use. Beijing was used to exemplify the different energy analysis processes, and the 42 economic sectors of the city were aggregated into seven components. It was determined that EFA quantifies both the primary and final energy consumption of the urban components by tracking the different types of fuel used by the urban economy. IOA accounts for the embodied energy consumption (direct and indirect) used to produce goods and services in the city, whereas the control analysis of ENA quantifies the specific embodied energy that is regulated by the activities within the city’s boundary. The network control analysis can also be applied to determining which economic sectors drive the energy consumption and to what extent these sectors are dependent on each other for energy. So-called “controlled energy” is a new concept that adds to the analysis of urban energy consumption, indicating the adjustable energy consumed by sectors. The integration of insights from all three accounting perspectives further our understanding of sustainable energy use in cities

Urban energy planning in Eskilstuna

DEFF Research Database (Denmark)

Groth, Niels Boje; Große, Juliane; Fertner, Christian

as a stakeholder of energy initiatives towards the general public. The efficiency of the first is very high, due to an omnipresence of ‘sustainability thinking’. The total effect of the latter is, however, much larger, due to the size of the arena. Principles of urban development are generally acknowledged...... in transport remains the key challenge. At municipal level the consumption of electricity is of special concern. Only about 25% of electricity it is possible to produce by local combined power and district heating plants. Some small additional power may be provided locally by e.g. solar cells...... as an important instrument for sustainability. Urban densification and urban connectivity to transport routes facilitated by public transport are the two main principles. Policies of sustainability are of ‘second-order’ as compared to the economic driven changes of the urban system. A prime ‘first...

Urban Wind Energy

DEFF Research Database (Denmark)

Beller, Christina

important for the implementation of wind energy conversion systems are the macro and micro wind climate, the siting within a micro wind climate and the choice of a wind turbine model most appropriate for the selected site. In the frame of this work, all these important elements are analyzed and a row......New trends e.g. in architecture and urban planning are to reduce energy needs. Several technologies are employed to achieve this, and one of the technologies, not new as such, is wind energy. Wind turbines are installed in cities, both by companies and private persons on both old and new buildings....... However, an overview of the energy content of the wind in cities and how consequently turbines shall be designed for such wind climates is lacking. The objective of the present work is to deliver an objective and fundamental overview of the social, practical and physical conditions relevant...

Urban Soil: Assessing Ground Cover Impact on Surface Temperature and Thermal Comfort.

Science.gov (United States)

Brandani, Giada; Napoli, Marco; Massetti, Luciano; Petralli, Martina; Orlandini, Simone

2016-01-01

The urban population growth, together with the contemporary deindustrialization of metropolitan areas, has resulted in a large amount of available land with new possible uses. It is well known that urban green areas provide several benefits in the surrounding environment, such as the improvement of thermal comfort conditions for the population during summer heat waves. The purpose of this study is to provide useful information on thermal regimes of urban soils to urban planners to be used during an urban transformation to mitigate surface temperatures and improve human thermal comfort. Field measurements of solar radiation, surface temperature (), air temperature (), relative humidity, and wind speed were collected on four types of urban soils and pavements in the city of Florence during summer 2014. Analysis of days under calm, clear-sky condition is reported. During daytime, sun-to-shadow differences for , apparent temperature index (ATI), and were significantly positive for all surfaces. Conversely, during nighttime, differences among all surfaces were significantly negative, whereas ATI showed significantly positive differences. Moreover, was significantly negative for grass and gravel. Relative to the shaded surfaces, was higher on white gravel and grass than gray sandstone and asphalt during nighttime, whereas gray sandstone was always the warmest surface during daytime. Conversely, no differences were found during nighttime for ATI and measured over surfaces that were exposed to sun during the day, whereas showed higher values on gravel than grass and asphalt during nighttime. An exposed surface warms less if its albedo is high, leading to a significant reduction of during daytime. These results underline the importance of considering the effects of surface characteristics on surface temperature and thermal comfort. This would be fundamental for addressing urban environment issues toward the heat island mitigation considering also the impact of urban

Quantifying the Trends in Land Surface Temperature and Surface Urban Heat Island Intensity in Mediterranean Cities in View of Smart Urbanization

Directory of Open Access Journals (Sweden)

Anastasios Polydoros

2018-02-01

Full Text Available Land Surface Temperature (LST is a key parameter for the estimation of urban fluxes as well as for the assessment of the presence and strength of the surface urban heat island (SUHI. In an urban environment, LST depends on the way the city has been planned and developed over time. To this end, the estimation of LST needs adequate spatial and temporal data at the urban scale, especially with respect to land cover/land use. The present study is divided in two parts: at first, satellite data from MODIS-Terra 8-day product (MOD11A2 were used for the analysis of an eighteen-year time series (2001–2017 of the LST spatial and temporal distribution in five major cities of the Mediterranean during the summer months. LST trends were retrieved and assessed for their statistical significance. Secondly, LST values and trends for each city were examined in relation to land cover characteristics and patterns in order to define the contribution of urban development and planning on LST; this information is important for the drafting of smart urbanization policies and measures. Results revealed (a positive LST trends in the urban areas especially during nighttime ranging from +0.412 °K in Marseille to +0.923 °K in Cairo and (b the SUHI has intensified during the last eighteen years especially during daytime in European Mediterranean cities, such as Rome (+0.332 °K and Barcelona (+0.307 °K.

The Impact of Urbanization on Energy Intensity in Saudi Arabia

Directory of Open Access Journals (Sweden)

Mounir Belloumi

2016-04-01

Full Text Available This paper investigates the long-term and causal relationship between energy intensity, real GDP per capita, urbanization and industrialization in Saudi Arabia over the period 1971–2012 using the breakpoint unit root tests developed by Perron (1989 and the autoregressive distributed lag (ARDL model bounds testing to cointegration proposed by Pesaran et al. (2001 and employing a modified version of the Granger causality test proposed by Toda and Yamamoto (1995. Additionally, to test the robustness of the results, the fully modified ordinary least squares (OLS regression, the dynamic OLS regression, and the Hansen test are used. Our results show that the variables are cointegrated when energy intensity is the dependent variable. It is also found that urbanization positively affects energy intensity in both the short term and the long term. Causality tests indicate that urbanization causes economic output that causes energy intensity in the long term. Our results do not support the urban compaction hypothesis where urban cities benefit from basic public services and economies of scale for public infrastructure. Therefore, measures that slow down the rapid urbanization process should be taken to reduce energy intensity in Saudi Arabia. In addition, reducing energy inefficiency in energy consumption should be a strategy to attain sustainable development in the near future in Saudi Arabia.

Urban form and energy use for transport. A Nordic experience

Energy Technology Data Exchange (ETDEWEB)

Naess, P

1995-02-10

The main research problem addressed in this thesis is the possible influence of several urban form variables on the amount of transportation, on the modal split between different means of transport, and on energy use for transportation. This problem is elucidated through five empirical investigations covering different geographic levels in a Nordic context, from individual employees and households to commuting regions. A main feature of the study is the combination of socioeconomic and urban form variables in empirical investigations, employing techniques of multivariate analysis. The investigations of residential areas and job sites have been based on travel surveys, while the investigations where the units of analysis are towns or regions have been based on fuel sales. The socioeconomic data have been collected from official statistics and from questionnaires. It is found that urban form variables exert important influences on transportation energy use. Urban density affects energy use for transportation. A central location of residences as well as workplaces is favourable with respect to energy conservation on an intra-urban scale, but not in a wider geographical context, where decentralization into several dense, relatively self-contained local communities distributed over the region is the most energy-saving pattern of regional development. Urban form characteristics favourable for minimizing transport energy requirements also seem favourable for energy conservation in buildings. 160 refs., 39 figs., 46 tabs.

Urban climate and energy demand interaction in Northern Eurasia

Science.gov (United States)

Kasilova, E. V.; Ginzburg, A. S.; Demchenko, P. F.

2017-11-01

The regional and urban climate change in Northern Eurasia is one of the main challenges for sustainable development of human habitats situated in boreal and temperate areas. The half of primary energy is spent for space heating even under quite a mild European climate. Implementation of the district heating in urban areas is currently seen as one of the key conditions of sustainable development. The clear understanding of main problems of the urban climateenergy demand interaction is crucial for both small towns and megacities. The specific features of the urban energy systems in Finland, Russia and China under the changing climate conditions were studied. Regional manifestations of the climate change were examined. The climate projections were established for urban regions of the Northern Eurasia. It was shown that the climate warming is likely to continue intensively there. History and actual development trends were discussed for the urban district heating systems in Russia, China and Finland. Common challenges linked with the climate change have been identified for the considered areas. Adaptation possibilities were discussed taking into account climate-energy interactions.

Nested high-resolution modeling of the impact of urbanization on regional climate in three vast urban agglomerations in China

Science.gov (United States)

Wang, Jun; Feng, Jinming; Yan, Zhongwei; Hu, Yonghong; Jia, Gensuo

2012-11-01

In this paper, the Weather Research and Forecasting Model, coupled to the Urban Canopy Model, is employed to simulate the impact of urbanization on the regional climate over three vast city agglomerations in China. Based on high-resolution land use and land cover data, two scenarios are designed to represent the nonurban and current urban land use distributions. By comparing the results of two nested, high-resolution numerical experiments, the spatial and temporal changes on surface air temperature, heat stress index, surface energy budget, and precipitation due to urbanization are analyzed and quantified. Urban expansion increases the surface air temperature in urban areas by about 1°C, and this climatic forcing of urbanization on temperature is more pronounced in summer and nighttime than other seasons and daytime. The heat stress intensity, which reflects the combined effects of temperature and humidity, is enhanced by about 0.5 units in urban areas. The regional incoming solar radiation increases after urban expansion, which may be caused by the reduction of cloud fraction. The increased temperature and roughness of the urban surface lead to enhanced convergence. Meanwhile, the planetary boundary layer is deepened, and water vapor is mixed more evenly in the lower atmosphere. The deficit of water vapor leads to less convective available potential energy and more convective inhibition energy. Finally, these combined effects may reduce the rainfall amount over urban areas, mainly in summer, and change the regional precipitation pattern to a certain extent.

How Can China Lighten Up? Urbanization, Industrialization and Energy Demand Scenarios

Energy Technology Data Exchange (ETDEWEB)

Aden, Nathaniel T.; Zheng, Nina; Fridley, David G.

2009-07-01

Urbanization has re-shaped China's economy, society, and energy system. Between 1990 and 2007 China added 290 million new urban residents, bringing the total urbanization rate to 45%. This population adjustment spurred energy demand for construction of new buildings and infrastructure, as well as additional residential use as rural biomass was replaced with urban commercial energy services. Primary energy demand grew at an average annual rate of 10% between 2000 and 2007. Urbanization's effect on energy demand was compounded by the boom in domestic infrastructure investment, and in the export trade following World Trade Organization (WTO) accession in 2001. Industry energy consumption was most directly affected by this acceleration. Whereas industry comprised 32% of 2007 U.S. energy use, it accounted for 75% of China's 2007 energy consumption. Five sub-sectors accounted for 78% of China's industry energy use in 2007: iron and steel, energy extraction and processing, chemicals, cement, and non-ferrous metals. Ferrous metals alone accounted for 25% of industry and 18% of total primary energy use. The rapid growth of heavy industry has led China to become by far the world's largest producer of steel, cement, aluminum, and other energy-intensive commodities. However, the energy efficiency of heavy industrial production continues to lag world best practice levels. This study uses scenario analysis to quantify the impact of urbanization and trade on industrial and residential energy consumption from 2000 to 2025. The BAU scenario assumed 67% urbanization, frozen export amounts of heavy industrial products, and achievement of world best practices by 2025. The China Lightens Up (CLU) scenario assumed 55% urbanization, zero net exports of heavy industrial products, and more aggressive efficiency improvements by 2025. The five dominant industry sub-sectors were modeled in both scenarios using a LEAP energy end-use accounting model. The results of

Surface urban heat island across 419 global big cities.

Science.gov (United States)

Peng, Shushi; Piao, Shilong; Ciais, Philippe; Friedlingstein, Pierre; Ottle, Catherine; Bréon, François-Marie; Nan, Huijuan; Zhou, Liming; Myneni, Ranga B

2012-01-17

Urban heat island is among the most evident aspects of human impacts on the earth system. Here we assess the diurnal and seasonal variation of surface urban heat island intensity (SUHII) defined as the surface temperature difference between urban area and suburban area measured from the MODIS. Differences in SUHII are analyzed across 419 global big cities, and we assess several potential biophysical and socio-economic driving factors. Across the big cities, we show that the average annual daytime SUHII (1.5 ± 1.2 °C) is higher than the annual nighttime SUHII (1.1 ± 0.5 °C) (P < 0.001). But no correlation is found between daytime and nighttime SUHII across big cities (P = 0.84), suggesting different driving mechanisms between day and night. The distribution of nighttime SUHII correlates positively with the difference in albedo and nighttime light between urban area and suburban area, while the distribution of daytime SUHII correlates negatively across cities with the difference of vegetation cover and activity between urban and suburban areas. Our results emphasize the key role of vegetation feedbacks in attenuating SUHII of big cities during the day, in particular during the growing season, further highlighting that increasing urban vegetation cover could be one effective way to mitigate the urban heat island effect.

Measuring Thermal Characteristics of Urban Landscapes

Science.gov (United States)

Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.

1999-01-01

The additional heating of the air over the city is the result of the replacement of naturally vegetated surfaces with those composed of asphalt, concrete, rooftops and other man-made materials. The temperatures of these artificial surfaces can be 20 to 40 C higher than vegetated surfaces. Materials such as asphalt store much of the sun's energy and remains hot long after sunset. This produces a dome of elevated air temperatures 5 to 8 C greater over the city, compared to the air temperatures over adjacent rural areas. This effect is called the "urban heat island". Urban landscapes are a complex mixture of vegetated and nonvegetated surfaces. It is difficult to take enough temperature measurements over a large city area to characterize the complexity of urban radiant surface temperature variability. However, the use of remotely sensed thermal data from airborne scanners are ideal for the task. In a study funded by NASA, a series of flights over Huntsville, Alabama were performed in September 1994 and over Atlanta, Georgia in May 1997. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace, what the benefits are of the urban forest in both mitigating the urban heat island effect, in making cities more aesthetically pleasing and more habitable environments, and in overall cooling of the community. In this presentation we will examine the techniques of analyzing remotely sensed data for measuring the effect of various urban surfaces on their contribution to the urban heat island effect.

Urban Systems and Energy Consumptions: A Critical Approach

Directory of Open Access Journals (Sweden)

Rocco Papa

2014-05-01

Full Text Available City transformations are also due to the development of new energy sources, which have influenced economy and lifestyles, as well as the physical and functional organization of urban systems. Cities are the key place where it is need to act for the achievement of strategic environmental objectives, such as reducing greenhouse gas emissions and energy saving. The hard resolution of these challenges depends on several factors: their multidimensional nature, the change of the economic and settlement development model, and also the complexity of the relationships between the elements that constitute the urban systems and that affect energy consumption. According to this awareness the Project Smart Energy Master for the energy management of territory financed by PON 04A2_00120 R & C Axis II, from 2012 to 2015 has been developed: it is aimed at supporting local authorities in the development of strategies for the reduction of energy consumption through actions designed to change behavior (in terms of use and energy consumption and to improve the energy efficiency of equipment and infrastructure. With the goal of describing some of the results of the methodological phase of this project, this paper proposes a review of the major studies on the issue of energy consumption at the urban scale in the first section; in the second section the outcomes of the first phase of the development of the comprehension/interpretive model related to the identification of the set of physical/environmental variables at urban scale, that most affect the energy consumption, are described; the third makes a critical review of the reference scientific literature, characterised by a too sectoral approach, compared to the complexity of the topic.

First results from the International Urban Energy Balance Model Comparison: Model Complexity

Science.gov (United States)

Blackett, M.; Grimmond, S.; Best, M.

2009-04-01

A great variety of urban energy balance models has been developed. These vary in complexity from simple schemes that represent the city as a slab, through those which model various facets (i.e. road, walls and roof) to more complex urban forms (including street canyons with intersections) and features (such as vegetation cover and anthropogenic heat fluxes). Some schemes also incorporate detailed representations of momentum and energy fluxes distributed throughout various layers of the urban canopy layer. The models each differ in the parameters they require to describe the site and the in demands they make on computational processing power. Many of these models have been evaluated using observational datasets but to date, no controlled comparisons have been conducted. Urban surface energy balance models provide a means to predict the energy exchange processes which influence factors such as urban temperature, humidity, atmospheric stability and winds. These all need to be modelled accurately to capture features such as the urban heat island effect and to provide key information for dispersion and air quality modelling. A comparison of the various models available will assist in improving current and future models and will assist in formulating research priorities for future observational campaigns within urban areas. In this presentation we will summarise the initial results of this international urban energy balance model comparison. In particular, the relative performance of the models involved will be compared based on their degree of complexity. These results will inform us on ways in which we can improve the modelling of air quality within, and climate impacts of, global megacities. The methodology employed in conducting this comparison followed that used in PILPS (the Project for Intercomparison of Land-Surface Parameterization Schemes) which is also endorsed by the GEWEX Global Land Atmosphere System Study (GLASS) panel. In all cases, models were run

Urban Imperviousness Effects on Summer Surface Temperatures Nearby Residential Buildings in Different Urban Zones of Parma

Directory of Open Access Journals (Sweden)

Marco Morabito

2017-12-01

Full Text Available Rapid and unplanned urban growth is responsible for the continuous conversion of green or generally natural spaces into artificial surfaces. The high degree of imperviousness modifies the urban microclimate and no studies have quantified its influence on the surface temperature (ST nearby residential building. This topic represents the aim of this study carried out during summer in different urban zones (densely urbanized or park/rural areas of Parma (Northern Italy. Daytime and nighttime ASTER images, the local urban cartography and the Italian imperviousness databases were used. A reproducible/replicable framework was implemented named “Building Thermal Functional Area” (BTFA useful to lead building-proxy thermal analyses by using remote sensing data. For each residential building (n = 8898, the BTFA was assessed and the correspondent ASTER-LST value (ST_BTFA and the imperviousness density were calculated. Both daytime and nighttime ST_BTFA significantly (p < 0.001 increased when high levels of imperviousness density surrounded the residential buildings. These relationships were mostly consistent during daytime and in densely urbanized areas. ST_BTFA differences between urban and park/rural areas were higher during nighttime (above 1 °C than daytime (about 0.5 °C. These results could help to identify “urban thermal Hot-Spots” that would benefit most from mitigation actions.

Reducing urban heat island effects to improve urban comfort and balance energy consumption in Bucharest (Romania)

Science.gov (United States)

Constantinescu, Dan; Ochinciuc, Cristina Victoria; Cheval, Sorin; Comşa, Ionuţ; Sîrodoev, Igor; Andone, Radu; Caracaş, Gabriela; Crăciun, Cerasella; Dumitrescu, Alexandru; Georgescu, Mihaela; Ianoş, Ioan; Merciu, Cristina; Moraru, Dan; Opriş, Ana; Paraschiv, Mirela; Raeţchi, Sonia; Saghin, Irina; Schvab, Andrei; Tătui-Văidianu, Nataşa

2017-04-01

In the recent decades, extreme temperature events and derived hazards are frequent and trigger noteworthy impacts in Romania, especially over the large urban areas. The cities produce significant disturbances of many elements of the regional climate, and generates adverse effects such as Urban Heat Islands (UHI). This presentation condenses the outputs of an ongoing research project (REDBHI) developed through (2013-2017) focused on developing a methodology for monitoring and forecasting indoor climate and energy challenges related to the intensity of UHI of Bucharest (Romania), based on relevant urban climate zones (UCZs). Multi-criteria correlations between the UHI and architectural, urban and landscape variables were determined, and the vulnerability of buildings expressed in the form of transfer function between indoor micro-climate and outdoor urban environment. The vulnerability of civil buildings was determined in relation with the potential for amplifying the thermal hazards intensity through the anthropogenic influence. The project REDBHI aims at developing innovative and original products, with direct applicability, which can be used in any urban settlement and have market potential with regards to energy design and consulting. The concrete innovative outcomes consist of a) localization of the Bucharest UCZs according to the UHI intensity, identifying reference buildings and sub-zones according to urban anthropic factors and landscape pattern; b) typology of representative buildings with regards to energy consumption and CO2 emitted as a result of building exploitation; c) 3D modelling of the reference buildings and of the thermal/energy reaction to severe climatic conditions d) empirical validation of the dynamic thermal/energy analysis; d) development of an pilot virtual studio capable to simulate climate alerts, analyse scenarios and suggest measures to mitigate the UHI effects, and disseminate the outcomes for educational purposes; e) compendium of

Can Aerosol Offset Urban Heat Island Effect?

Science.gov (United States)

Jin, M. S.; Shepherd, J. M.

2009-12-01

The Urban Heat Island effect (UHI) refers to urban skin or air temperature exceeding the temperatures in surrounding non-urban regions. In a warming climate, the UHI may intensify extreme heat waves and consequently cause significant health and energy problems. Aerosols reduce surface insolation via the direct effect, namely, scattering and absorbing sunlight in the atmosphere. Combining the National Aeronautics and Space Administration (NASA) AERONET (AErosol RObotic NETwork) observations over large cities together with Weather Research and Forecasting Model (WRF) simulations, we find that the aerosol direct reduction of surface insolation range from 40-100 Wm-2, depending on seasonality and aerosol loads. As a result, surface skin temperature can be reduced by 1-2C while 2-m surface air temperature by 0.5-1C. This study suggests that the aerosol direct effect is a competing mechanism for the urban heat island effect (UHI). More importantly, both aerosol and urban land cover effects must be adequately represented in meteorological and climate modeling systems in order to properly characterize urban surface energy budgets and UHI.

Urban food-energy-water nexus: a case study of Beijing

Science.gov (United States)

Wu, Z.; Shao, L.

2017-12-01

The interactions between the food, energy and water sectors are of great importance to urban sustainable development. This work presents a framework to analyze food-energy-water (FEW) nexus of a city. The method of multi-scale input-output analysis is applied to calculate consumption-based energy and water use that is driven by urban final demand. It is also capable of accounting virtual energy and water flows that is embodied in trade. Some performance indicators are accordingly devised for a comprehensive understanding of the urban FEW nexus. A case study is carried out for the Beijing city. The embodied energy and water use of foods, embodied water of energy industry and embodied energy of water industry are analyzed. As a key node of economic network, Beijing exchanges a lot of materials and products with external economic systems, especially other Chinese provinces, which involves massive embodied energy and water flows. As a result, Beijing relies heavily on outsourcing energy and water to meet local people's consumption. It is revealed that besides the apparent supply-demand linkages, the underlying interconnections among food, water and energy sectors are critical to create sustainable urban areas.

Multicriteria Spatial Decision Support Systems for Future Urban Energy Retrofitting Scenarios

Directory of Open Access Journals (Sweden)

Patrizia Lombardi

2017-07-01

Full Text Available Nowadays, there is an increasing concern about sustainable urban energy development taking into account national priorities of each city. Many cities have started to define future strategies and plans to reduce energy consumption and greenhouse gas emissions. Urban energy scenarios involve the consideration of a wide range of conflicting criteria, both socio-economic and environmental ones. Moreover, decision-makers (DMs require proper tools that can support their choices in a context of multiple stakeholders and a long-term perspective. In this context, Multicriteria Spatial Decision Support Systems (MC-SDSS are often used in order to define and analyze urban scenarios since they support the comparison of different solutions, based on a combination of multiple factors. The main problem, in relation to urban energy retrofitting scenarios, is the lack of appropriate knowledge and evaluation criteria. The latter are crucial for delivering and assessing urban energy scenarios through a MC-SDSS tool. The main goal of this paper is to analyze and test two different methods for the definition and ranking of the evaluation criteria. More specifically, the paper presents an on-going research study related to the development of a MC-SDSS tool able to identify and evaluate alternative energy urban scenarios in a long-term period perspective. This study refers to two Smart City and Communities research projects, namely: DIMMER (District Information Modeling and Management for Energy Reduction and EEB (Zero Energy Buildings in Smart Urban Districts.

Do urbanization and industrialization affect energy intensity in developing countries?

International Nuclear Information System (INIS)

Sadorsky, Perry

2013-01-01

Against a backdrop of concerns about climate change, peak oil, and energy security issues, reducing energy intensity is often advocated as a way to at least partially mitigate these impacts. This study uses recently developed heterogeneous panel regression techniques like mean group estimators and common correlated effects estimators to model the impact that income, urbanization and industrialization has on energy intensity for a panel of 76 developing countries. In the long-run, a 1% increase in income reduces energy intensity by − 0.45% to − 0.35%. Long-run industrialization elasticities are in the range 0.07 to 0.12. The impact of urbanization on energy intensity is mixed. In specifications where the estimated coefficient on urbanization is statistically significant, it is slightly larger than unity. The implications of these results for energy policy are discussed. - Highlights: ► The impact of urbanization and industrialization on energy intensity is modeled. ► Use recently developed heterogeneous panel regression techniques ► The model is tested on a panel of developing countries. ► Income has a negative impact on energy intensity. ► Industrialization has a positive impact on energy intensity

A simple tool to evaluate the effect of the urban canyon on daylight level and energy demand in the early stages of building design

DEFF Research Database (Denmark)

Petersen, Steffen; Momme, Amalie Jin; Hviid, Christian Anker

2014-01-01

Daylight is a restricted resource in urban contexts. Rooms situated in an urban context often have a significant proportion of the sky and the sun blocked out by the urban building mass. The reduced direct daylight potential makes daylight reflected from outdoor surfaces an important daylight sou...... the impact of urban canyon parameters on indoor environment and energy performance....

Energy and fuel efficient parallel mild hybrids for urban roads

International Nuclear Information System (INIS)

Babu, Ajay; Ashok, S.

2016-01-01

Highlights: • Energy and fuel savings depend on battery charge variations and the vehicle speed parameters. • Indian urban conditions provide lot of scope for energy and fuel savings in mild hybrids. • Energy saving strategy has lower payback periods than the fuel saving one in mild hybrids. • Sensitivity to parameter variations is the least for energy saving strategy in a mild hybrid. - Abstract: Fuel economy improvements and battery energy savings can promote the adoption of parallel mild hybrids for urban driving conditions. The aim of this study is to establish these benefits through two operating modes: an energy saving mode and a fuel saving mode. The performances of a typical parallel mild hybrid using these modes were analysed over urban driving cycles, in the US, Europe, and India, with a particular focus on the Indian urban conditions. The energy pack available from the proposed energy-saving operating mode, in addition to the energy already available from the conventional mode, was observed to be the highest for the representative urban driving cycle of the US. The extra energy pack available was found to be approximately 21.9 times that available from the conventional mode. By employing the proposed fuel saving operating mode, the fuel economy improvement achievable in New York City was observed to be approximately 22.69% of the fuel economy with the conventional strategy. The energy saving strategy was found to possess the lowest payback periods and highest immunity to variations in various cost parameters.

Optimal energy management of urban rail systems: Key performance indicators

International Nuclear Information System (INIS)

González-Gil, A.; Palacin, R.; Batty, P.

2015-01-01

Highlights: • An overall picture of urban rail energy use is provided. • Performance indicators are developed for urban rail system energy optimisation. • A multi-level methodology for assessing energy efficiency measures is presented. - Abstract: Urban rail systems are facing increasing pressure to minimise their energy consumption and thusly reduce their operational costs and environmental impact. However, given the complexity of such systems, this can only be effectively achieved through a holistic approach which considers the numerous interdependences between subsystems (i.e. vehicles, operations and infrastructure). Such an approach requires a comprehensive set of energy consumption-related Key Performance Indicators (KEPIs) that enable: a multilevel analysis of the actual energy performance of the system; an assessment of potential energy saving strategies; and the monitoring of the results of implemented measures. This paper proposes an original, complete list of KEPIs developed through a scientific approach validated by different stakeholders. It consists of a hierarchical list of 22 indicators divided into two levels: 10 key performance indicators, to ascertain the performance of the whole system and complete subsystems; and 12 performance indicators, to evaluate the performance of single units within subsystems, for example, a single rail vehicle or station. Additionally, the paper gives a brief insight into urban rail energy usage by providing an adequate context in which to understand the proposed KEPIs, together with a methodology describing their application when optimising the energy consumption of urban rail systems

Urban trees and light-colored surfaces as a climate change strategy: Results from the US and potential in developing countries

Energy Technology Data Exchange (ETDEWEB)

Akbari, H.; Sathaye, J. [Lawrence Berkeley National Lab., CA (United States)

1996-12-31

This paper discusses the impact of two strategies in an urban environment for effecting substantial energy savings. They are the use of light colored materials on roofing and other flat surfaces, and the planting of additional trees. The lighter colored roofing materials will reflect more solar heat, resulting in lowered air conditioning costs. The additional trees will provide more shading, thereby increasing comfort, and will act as an aid in dropping the ambient temperature by means of evapotranspiration through the leaf systems. Both of these effects will reduce the direct energy inputs leading to air conditioning loads in an urban setting, and indirectly they will have an impact on urban smog though the lowered ambient temperature. The authors also discuss the applications of these ideas in developing countries, where often building energy costs can consume half of developed electrical capacity, and which tend to be in warmer climates. The density of many major urban areas in developing countries make the use of trees much harder to implement.

Energy prices and the urban poor in India: Some policy imperatives

International Nuclear Information System (INIS)

Bhatia, R.

1989-01-01

The objectives of this paper are: to study the pattern of domestic energy consumption of poor people in selected urban centers in India; to analyse the role of prices in determining the cost of providing energy for lighting and cooking in these urban areas; and to suggest policy alternatives which can reduce the cost meeting basic energy needs of the urban poor. Refs, 10 tabs

Measuring Thermal Characteristics of Urban Landscapes

Science.gov (United States)

Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.

1999-01-01

The additional heating of the air over the city is the result of the replacement of naturally vegetated surfaces with those composed of asphalt, concrete, rooftops and other man-made materials. The temperatures of these artificial surfaces can be 20 to 40 C higher than vegetated surfaces. Materials such as asphalt store much of the sun's energy and remains hot long after sunset. This produces a dome of elevated air temperatures 5 to 8 C greater over the city, compared to the air temperatures over adjacent rural areas. This effect is called the "urban heat island". Urban landscapes are a complex mixture of vegetated and nonvegetated surfaces. It is difficult to take enough temperature measurements over a large city area to characterize the complexity of urban radiant surface temperature variability. However, the use of remotely sensed thermal data from airborne scanners are ideal for the task. In a study funded by NASA, a series of flights over Huntsville, Alabama were performed in September 1994 and over Atlanta, Georgia in May 1997. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., urban forest in both mitigating the urban heat island effect, in making cities more aesthetically pleasing and more habitable environments, and in overall cooling of the community. In this presentation we will examine the techniques of analyzing remotely sensed data for measuring the effect of various urban surfaces on their contribution to the urban heat island effect.

ANALYSIS OF THE INTRA-CITY VARIATION OF URBAN HEAT ISLAND AND ITS RELATION TO LAND SURFACE/COVER PARAMETERS

Directory of Open Access Journals (Sweden)

D. Gerçek

2016-06-01

Full Text Available Along with urbanization, sealing of vegetated land and evaporation surfaces by impermeable materials, lead to changes in urban climate. This phenomenon is observed as temperatures several degrees higher in densely urbanized areas compared to the rural land at the urban fringe particularly at nights, so-called Urban Heat Island. Urban Heat Island (UHI effect is related with urban form, pattern and building materials so far as it is associated with meteorological conditions, air pollution, excess heat from cooling. UHI effect has negative influences on human health, as well as other environmental problems such as higher energy demand, air pollution, and water shortage. Urban Heat Island (UHI effect has long been studied by observations of air temperature from thermometers. However, with the advent and proliferation of remote sensing technology, synoptic coverage and better representations of spatial variation of surface temperature became possible. This has opened new avenues for the observation capabilities and research of UHIs. In this study, "UHI effect and its relation to factors that cause it" is explored for İzmit city which has been subject to excess urbanization and industrialization during the past decades. Spatial distribution and variation of UHI effect in İzmit is analysed using Landsat 8 and ASTER day & night images of 2015 summer. Surface temperature data derived from thermal bands of the images were analysed for UHI effect. Higher temperatures were classified into 4 grades of UHIs and mapped both for day and night. Inadequate urban form, pattern, density, high buildings and paved surfaces at the expanse of soil ground and vegetation cover are the main factors that cause microclimates giving rise to spatial variations in temperatures across cities. These factors quantified as land surface/cover parameters for the study include vegetation index (NDVI, imperviousness (NDISI, albedo, solar insolation, Sky View Factor (SVF, building

Analysis of the Intra-City Variation of Urban Heat Island and its Relation to Land Surface/cover Parameters

Science.gov (United States)

Gerçek, D.; Güven, İ. T.; Oktay, İ. Ç.

2016-06-01

Along with urbanization, sealing of vegetated land and evaporation surfaces by impermeable materials, lead to changes in urban climate. This phenomenon is observed as temperatures several degrees higher in densely urbanized areas compared to the rural land at the urban fringe particularly at nights, so-called Urban Heat Island. Urban Heat Island (UHI) effect is related with urban form, pattern and building materials so far as it is associated with meteorological conditions, air pollution, excess heat from cooling. UHI effect has negative influences on human health, as well as other environmental problems such as higher energy demand, air pollution, and water shortage. Urban Heat Island (UHI) effect has long been studied by observations of air temperature from thermometers. However, with the advent and proliferation of remote sensing technology, synoptic coverage and better representations of spatial variation of surface temperature became possible. This has opened new avenues for the observation capabilities and research of UHIs. In this study, "UHI effect and its relation to factors that cause it" is explored for İzmit city which has been subject to excess urbanization and industrialization during the past decades. Spatial distribution and variation of UHI effect in İzmit is analysed using Landsat 8 and ASTER day & night images of 2015 summer. Surface temperature data derived from thermal bands of the images were analysed for UHI effect. Higher temperatures were classified into 4 grades of UHIs and mapped both for day and night. Inadequate urban form, pattern, density, high buildings and paved surfaces at the expanse of soil ground and vegetation cover are the main factors that cause microclimates giving rise to spatial variations in temperatures across cities. These factors quantified as land surface/cover parameters for the study include vegetation index (NDVI), imperviousness (NDISI), albedo, solar insolation, Sky View Factor (SVF), building envelope

Urban energy generation and the role of cities

DEFF Research Database (Denmark)

Groth, Niels Boje; Fertner, Christian; Große, Juliane

2016-01-01

Although a major part of energy consumption happens in cities, contemporary energy generation is less obviously connected to the urban structure. Energy based on fossil fuels and consumed in transportation is produced at global scale; energy for electricity is usually distributed through a national...... or continental grid; energy for heating, if related to district heating systems or the use of local/regional resources for its generation (e.g. biomass, waste), has a more local or at least regional character. In the latter case, electricity might be a by-product of combined-heat-power plants, but still feeding...... on energy generation and distribution. However, contemporary focus on sustainable and efficient use of resources and energy at local level, mainstreaming of renewable energy production and ideas of urban energy harvesting put energy generation again on the local agenda. The role of cities can be twofold: (1...

Energy in urban and regional planning. ; Energia yhdyskuntasuunnittelussa. Rohkeita ratkaisuja kestaevaempaeaen tulevaisuuteen

Energy Technology Data Exchange (ETDEWEB)

Ahonen, A.-M.; Nuorkivi, A. (eds.)

2013-03-01

Urban and regional planner is the first in the row to choose whether any renewable energy system, comprising production, storing and distribution, will be economic and environmentally sound in the subject planning area during the years to come. In order make right choices, understanding of the links prevailing between urban and energy planning as well as co-planning with energy experts is essential. So far there has not been systematic training to develop these competencies among urban and regional planners. In the UP-RES project (Urban Planners with Renewable Energy Skills) the project partners organized several pilot trainings in Germany, Hungary, Spain and the United Kingdom during 2011-2012. The objective of the pilots was to train planners understand the basics of renewable energy and energy related emissions. Training of urban and regional planners to understand energy issues as well as supporting co-planning between energy and urban planning experts have appeared to be productive ways towards more sustainable communities. This publication has been an essential part of the Finnish pilot training. The learning project case reports in this publication have been written by the training participants as a completion of their course. The cases were made in groups and the topics were chosen by the groups themselves. All projects focused on utilizing renewable energies and promoting energy efficiency in urban and regional planning. This publication consists of five reports: Inclusion of energy on various hierarchical levels of planning: major pain spots, gate keepers and points of impact. Comparison of measuring tools for renewable energy and energy efficiency. Inclusion of renewable energy systems and energy efficiency in regional planning cases in Finnish cities of Oulu, Espoo, Jyvaskyla and Kuopio. Metamorphosis of Talma village to a sustainable suburban area. Measures to improve energy efficiency of spatial plans. Based on the project reports, energy

Characterizing polycyclic aromatic hydrocarbon build-up processes on urban road surfaces

International Nuclear Information System (INIS)

Liu, Liang; Liu, An; Li, Dunzhu; Zhang, Lixun; Guan, Yuntao

2016-01-01

Reliable prediction models are essential for modeling pollutant build-up processes on urban road surfaces. Based on successive samplings of road deposited sediments (RDS), this study presents empirical models for mathematical replication of the polycyclic aromatic hydrocarbon (PAH) build-up processes on urban road surfaces. The contaminant build-up behavior was modeled using saturation functions, which are commonly applied in US EPA's Stormwater Management Model (SWMM). Accurate fitting results were achieved in three typical urban land use types, and the applicability of the models was confirmed based on their acceptable relative prediction errors. The fitting results showed high variability in PAH saturation value and build-up rate among different land use types. Results of multivariate data and temporal-based analyses suggested that the quantity and property of RDS significantly influenced PAH build-up. Furthermore, pollution sources, traffic parameters, road surface conditions, and sweeping frequency could synthetically impact the RDS build-up and RDS property change processes. Thus, changes in these parameters could be the main reason for variations in PAH build-up in different urban land use types. - Highlights: • Sufficient robust prediction models were established for analysis of PAH build-up on urban road surfaces. • PAH build-up processes showed high variability among different land use types. • Pollution sources as well as the quantity and property of RDS mainly influenced PAH build-up. - Sufficient robust prediction models were established for analysis of PAH build-up on urban road surfaces. Pollution sources as well as the quantity and property of RDS mainly influenced PAH build-up.

Retroreflective façades for urban heat island mitigation: Experimental investigation and energy evaluations

International Nuclear Information System (INIS)

Rossi, Federico; Castellani, Beatrice; Presciutti, Andrea; Morini, Elena; Filipponi, Mirko; Nicolini, Andrea; Santamouris, Matheos

2015-01-01

Highlights: • Retro-reflective (RR) materials are an effective strategy for mitigating UHI. • Optical properties of RR materials are assessed by a new experimental facility. • Angular distribution of reflected radiation is assessed during daytime. • RR component is treated as a diffusely reflected radiation by a reduction factor. • An algorithm evaluates the cooling potential of RR materials in urban canyons. - Abstract: The optimization of optical properties of buildings’ envelope and urban paving represents an important research field for reducing the urban heat island effect. The overheating of a surface exposed to sunlight can be reduced by improving solar reflectance. In this sense, several studies have demonstrated the positive effect of cool materials on UHI mitigation. In addition to traditional cool materials, retroreflective (RR) materials have been recently proposed for this application. The present paper aims at the assessment of angular reflectance of RR films for several inclination angles of solar radiation. To reproduce variation of solar radiation’s inclination during the daytime, an ad hoc experimental setup was designed and used. Characterization of RR materials when hit by solar radiation with different inclinations allows to assess their behaviour on daytime if used as novel urban coatings for mitigation of the UHI phenomenon. Measurement results are used as input for an original algorithm which allows to quantify cooling potential of RR materials in terms of energy reflected and sent beyond the urban canyon. The experimental characterization and energy evaluations showed that RR materials could be effectively applied as coatings on urban paving and building envelope, in order to reduce the circulating energy into the canyon

Temporal variations of surface water quality in urban, suburban and rural areas during rapid urbanization in Shanghai, China

International Nuclear Information System (INIS)

Wang Junying; Da Liangjun; Song Kun; Li Bailian

2008-01-01

As the economic and financial center of China, Shanghai has experienced an extensive urban expansion since the early 1980s, with an attendant cost in environmental degradation. We use an integrated pollution index to study the temporal variations of surface water quality in urban, suburban and rural areas between 1982 and 2005. Data on monitored cross-sections were collected from the Shanghai Environmental Monitoring Center. The results indicated that the spatial pattern of surface water quality was determined by the level of urbanization. Surface water qualities in urban and suburban areas were improved by strengthening the environmental policies and management, but were worsening in rural areas. The relationship between economic growth and surface water quality in Shanghai showed an inversed-U-shaped curve, which reflected a similar pattern in most developed countries. This research suggests that decision makers and city officials should be more aware of the recent pollution increases in Shanghai. - An integrated pollution index documents the deterioration of water quality in greater Shanghai, recently most serious in rural sections

Seasonal Variations of the Surface Urban Heat Island in a Semi-Arid City

Directory of Open Access Journals (Sweden)

Sirous Haashemi

2016-04-01

Full Text Available The process of the surface urban heat island (SUHI varies with latitude, climate, topography and meteorological conditions. This study investigated the seasonal variability of SUHI in the Tehran metropolitan area, Iran, with respect to selected surface biophysical variables. Terra Moderate Resolution Imaging Spectroradiometer (MODIS Land Surface Temperature (LST was retrieved as nighttime LST data, while daytime LST was retrieved from Landsat 8 Thermal Infrared Sensor (TIRS using the split-window algorithm. Both data covered the time period from September 2013 to September 2015. To assess SUHI intensity, we employed three SUHI indicators, i.e., the LST difference of urban-rural, that of urban-agriculture and that of urban-water. Physical and biophysical surface variables, including land use and land cover (LULC, elevation, impervious surface (IS, fractional vegetation cover (FVC and albedo, were selected to estimate the relationship between LST seasonal variability and the surface properties. Results show that an inversion of the SUHI phenomenon (i.e., surface urban cool island existed at daytime with the maximal value of urban-rural LST difference of −4 K in March; whereas the maximal value of SUHI at nighttime yielded 3.9 K in May. When using the indicators of urban-agriculture and urban-water LST differences, the maximal value of SUHI was found to be 8.2 K and 15.5 K, respectively. Both results were observed at daytime, suggesting the role of bare soils in the inversion of the SUHI phenomenon with the urban-rural indicator. Maximal correlation was observed in the relationship between night LST and elevation in spring (coefficient: −0.76, night LST and IS in spring (0.60, night LST and albedo in winter (−0.53 and day LST with fractional vegetation cover in summer (−0.41. The relationship between all surface properties with LST possessed large seasonal variations, and thus, using these relationships for SUHI modeling may not be

Fine-resolution Modeling of Urban-Energy Systems' Water Footprint in River Networks

Science.gov (United States)

McManamay, R.; Surendran Nair, S.; Morton, A.; DeRolph, C.; Stewart, R.

2015-12-01

Characterizing the interplay between urbanization, energy production, and water resources is essential for ensuring sustainable population growth. In order to balance limited water supplies, competing users must account for their realized and virtual water footprint, i.e. the total direct and indirect amount of water used, respectively. Unfortunately, publicly reported US water use estimates are spatially coarse, temporally static, and completely ignore returns of water to rivers after use. These estimates are insufficient to account for the high spatial and temporal heterogeneity of water budgets in urbanizing systems. Likewise, urbanizing areas are supported by competing sources of energy production, which also have heterogeneous water footprints. Hence, a fundamental challenge of planning for sustainable urban growth and decision-making across disparate policy sectors lies in characterizing inter-dependencies among urban systems, energy producers, and water resources. A modeling framework is presented that provides a novel approach to integrate urban-energy infrastructure into a spatial accounting network that accurately measures water footprints as changes in the quantity and quality of river flows. River networks (RNs), i.e. networks of branching tributaries nested within larger rivers, provide a spatial structure to measure water budgets by modeling hydrology and accounting for use and returns from urbanizing areas and energy producers. We quantify urban-energy water footprints for Atlanta, GA and Knoxville, TN (USA) based on changes in hydrology in RNs. Although water intakes providing supply to metropolitan areas were proximate to metropolitan areas, power plants contributing to energy demand in Knoxville and Atlanta, occurred 30 and 90km outside the metropolitan boundary, respectively. Direct water footprints from urban landcover primarily comprised smaller streams whereas indirect footprints from water supply reservoirs and energy producers included

Converting Paddy Rice Field to Urban Use Dramatically Altered the Water and Energy Balances in Southern China

Science.gov (United States)

Hao, L.; Sun, G.; Liu, Y.; Qin, M.; Huang, X.; Fang, D.

2017-12-01

Paddy rice wetlands are the main land use type across southern China, which impact the regional environments by affecting evapotranspiration (ET) and other water and energy related processes. Our study focuses on the effects of land-cover change on water and energy processes in the Qinhuai River Basin, a typical subtropical humid region that is under rapid ecological and economical transformations. This study integrates multiple methods and techniques including remote sensing, water and energy balance model (i.e., Surface Energy Balance Algorithm for Land, SEBAL), ecohydrological model (i.e., Soil and Water Assessment Tool, SWAT), and ground observation (Eddy Covariance measurement, etc.). We found that conversion of paddy rice field to urban use led to rise in vapor pressure deficit (VPD) and reduction in ET, and thus resulted in changes in local and regional water and heat balance. The effects of the land-use change on ET and VPD overwhelmed the effects of regional climate warming and climate variability. We conclude that the ongoing large-scale urbanization of the rice paddy-dominated regions in humid southern China and East Asia will likely exacerbate environmental consequences (e.g., elevated storm-flow volume, aggravated flood risks, and intensified urban heat island and urban dry island effects). The potential role of vegetated land cover in moderating water and energy balances and maintaining a stable climate should be considered in massive urban planning and global change impact assessment in southern China.

Renewable Energy in Urban Areas: Worldwide Research Trends

Directory of Open Access Journals (Sweden)

Miguel-Angel Perea-Moreno

2018-03-01

Full Text Available This study aims to highlight the contribution made by different international institutions in the field of urban generation of renewable energy, as a key element to achieve sustainability. This has been possible through the use of the Scopus Elsevier database, and the application of bibliometric techniques through which the articles content published from 1977 to 2017 has been analysed. The results shown by Scopus (e.g., journal articles and conferences proceedings have been taken into account for further analysis by using the following search pattern (TITLE-ABS-KEY ({Renewable energy} AND ({urban} OR ({cit*}. In order to carry out this study, key features of the publications have been taken into consideration, such as type of document, language, thematic area, type of publication, and keywords. As far as keywords are concerned, renewable energy, sustainability, sustainable development, urban areas, city, and energy efficiency, have been the most frequently used. The results found have been broken down both geographically and by institution, showing that China, the United States, the United Kingdom, Italy, Germany and India are the main research countries and Chinese Academy of Sciences, Ministry of Education China and Tsinghua University the major contributing institutes. With regard to the categories, Energy, Environmental Sciences, and Engineering are positioned as the most active categories. The scientific community agrees that the study of the renewable energy generation in cities is of vital importance to achieve more sustainable cities, and for the welfare of a growing urban population. Moreover, this is in line with the energy policies adopted by most of developed countries in order to mitigate climate change effects.

EFFECTS OF PAVEMENT SURFACE TEMPERATURE ON THE MODIFICATION OF URBAN THERMAL ENVIRONMENT

Directory of Open Access Journals (Sweden)

SARAT, Adebayo-Aminu

2012-07-01

Full Text Available Urban centres continue to experience escalating average summer temperature over the last fifty years. Temperature in the urban core cites have been rising due to rapid growth of urbanization in the latter half of the twentieth century (Akbari et al., 1989. Outdoor experiments were conducted to investigate the effects of different movement of materials on the urban thermal environment. Meteorological conditions such as air temperature, pavement surface temperature, Relative humidity and wind velocity were recorded to determine temperature differences among Asphalt/concrete, interlocking bricks and grass surfaces.

Urbanization increased metal levels in lake surface sediment and catchment topsoil of waterscape parks

Energy Technology Data Exchange (ETDEWEB)

Li, Hong-Bo [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Yu, Shen, E-mail: syu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Li, Gui-Lin [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Liu, Yi; Yu, Guang-Bin [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Deng, Hong [Department of Environmental Sciences, Tiantong National Station of Forest Ecosystem, Key Laboratory of Urbanization and Ecological Restoration, East China Normal University, Shanghai 200062 (China); Wu, Sheng-Chun [State Key Laboratory in Marine Pollution, Biology and Chemistry Department, City University of Hong Kong, Hong Kong (China); Wong, Ming-Hung [Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Hong Kong (China)

2012-08-15

Lake surface sediment is mainly derived from topsoil in its catchment. We hypothesized that distribution of anthropogenic metals would be homogenous in lake surface sediment and the lake's catchment topsoil. Anthropogenic metal distributions (cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) in fourteen waterscape parks were investigated in surface sediments and catchment topsoils and possible source homogeneity was tested using stable Pb isotopic ratio analysis. The parks were located along an urbanization gradient consisting of suburban (SU), developing urban (DIU), developed urban (DDU), and central urban core (CUC) areas in Shanghai, China. Results indicated that surface lake sediments and catchment topsoils in the CUC parks were highly contaminated by the investigated anthropogenic metals. Total metal contents in surface sediment and topsoil gradually increased along the urbanization gradient from the SU to CUC areas. Generally, the surface sediments had greater total metal contents than their catchment topsoils. These results suggest that urbanization drives the anthropogenic metal enrichment in both surface sediment and its catchment topsoil in the waterscape parks. Soil fine particles (< 63 {mu}m) and surface sediments had similar enrichment ratios of metals, suggesting that surface runoff might act as a carrier for metals transporting from catchment to lake. Stable Pb isotope ratio analysis revealed that the major anthropogenic Pb source in surface sediment was coal combustion as in the catchment topsoil. Urbanization also correlated with chemical fractionation of metals in both surface sediment and catchment topsoil. From the SU to the CUC parks, amounts of labile metal fractions increased while the residual fraction of those metals remained rather constant. In short, urbanization in Shanghai drives anthropogenic metal distribution in environmental matrices and the sources were homogenous. -- Highlights: Black-Right-Pointing-Pointer Obvious

Urbanization increased metal levels in lake surface sediment and catchment topsoil of waterscape parks

International Nuclear Information System (INIS)

Li, Hong-Bo; Yu, Shen; Li, Gui-Lin; Liu, Yi; Yu, Guang-Bin; Deng, Hong; Wu, Sheng-Chun; Wong, Ming-Hung

2012-01-01

Lake surface sediment is mainly derived from topsoil in its catchment. We hypothesized that distribution of anthropogenic metals would be homogenous in lake surface sediment and the lake's catchment topsoil. Anthropogenic metal distributions (cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) in fourteen waterscape parks were investigated in surface sediments and catchment topsoils and possible source homogeneity was tested using stable Pb isotopic ratio analysis. The parks were located along an urbanization gradient consisting of suburban (SU), developing urban (DIU), developed urban (DDU), and central urban core (CUC) areas in Shanghai, China. Results indicated that surface lake sediments and catchment topsoils in the CUC parks were highly contaminated by the investigated anthropogenic metals. Total metal contents in surface sediment and topsoil gradually increased along the urbanization gradient from the SU to CUC areas. Generally, the surface sediments had greater total metal contents than their catchment topsoils. These results suggest that urbanization drives the anthropogenic metal enrichment in both surface sediment and its catchment topsoil in the waterscape parks. Soil fine particles (< 63 μm) and surface sediments had similar enrichment ratios of metals, suggesting that surface runoff might act as a carrier for metals transporting from catchment to lake. Stable Pb isotope ratio analysis revealed that the major anthropogenic Pb source in surface sediment was coal combustion as in the catchment topsoil. Urbanization also correlated with chemical fractionation of metals in both surface sediment and catchment topsoil. From the SU to the CUC parks, amounts of labile metal fractions increased while the residual fraction of those metals remained rather constant. In short, urbanization in Shanghai drives anthropogenic metal distribution in environmental matrices and the sources were homogenous. -- Highlights: ► Obvious urbanization effect on metal

London and beyond: Taking a closer look at urban energy policy

International Nuclear Information System (INIS)

Keirstead, James; Schulz, Niels B.

2010-01-01

This paper considers the field of urban energy policy, a neglected yet important topic. Cities account for approximately two-thirds of global primary energy consumption creating significant benefits and costs. As a result there has been growing interest in the contribution of cities to global energy policy issues such as climate change but a number of significant questions remain: e.g. how do energy policy processes differ between national and urban scales, and how can cities contribute most effectively to global policy goals? We present the results of interviews with key stakeholders in London to illustrate some unique features of the urban energy policy cycle. We then take a wider view, proposing a research agenda with three key goals: describing the global variety of urban energy consumption and policy; understanding the resulting diversity in responsibility, vulnerability and capacity; and developing shared procedures and solutions. Tackling these questions is vital if cities are to contribute fully to current energy policy efforts.

Influence of Urbanization Factors on Surface Urban Heat Island Intensity: A Comparison of Countries at Different Developmental Phases

Directory of Open Access Journals (Sweden)

Yaoping Cui

2016-07-01

Full Text Available Urbanization is a global problem with demographic trends. The urban heat island plays a dominant role in local climate systems. Despite existing efforts to understand the impacts of multiple urbanization factors on the urban heat island globally, very little is known about the attribution of urban heat island magnitude to urbanization in different locations or developmental phases. In this study, based on global land surface temperature data, urban spatial domain data, gross domestic product (GDP, and population data, we analyzed the influence of multiple urbanization factors on global surface urban heat island intensity (SUHII. We also tentatively compared the abovementioned factors between different regions across the globe, especially between China and the USA, the largest countries that are experiencing or have experienced rapid urbanization in recent decades. The results showed that global SUHII had remarkable spatial heterogeneity due to the geographical and socioeconomic variation between cities. There was a significant correlation between SUHII and population as well as GDP in global cities. Moreover, this study suggested that the impacts of population on SUHII might be stronger in the early stages of urbanization, and the GDP factor would become a critical factor at a certain development level. The urban area also had non-ignorable impacts on SUHII, while the correlation between SUHII and urban shape was relatively weak. All these may imply that the best approach to slow down SUHII is to find other solutions, e.g., optimize the spatial configuration of urban internal landscapes, when the urbanization reaches a high level.

CADDIS Volume 2. Sources, Stressors and Responses: Urbanization - Energy Sources

Science.gov (United States)

Introduction to changes in basal energy sources with urbanization, overview of terrestrial leaf litter dynamics in urban streams, overview of how urbanization can affect primary production, respiration, and dissolved organic carbon quantity and quality.

Structure of the urban moisture field

International Nuclear Information System (INIS)

Sisterson, D.L.; Dirks, R.A.

1975-01-01

In the 26 July 1974 case study in St. Louis as a part of Project METROMEX, aircraft and surface network stations were used to determine specific humidity and potential temperature patterns near the surface and at two levels within the mixing layer. From the data acquired at these three levels, three-dimensional analyses of the moisture fields in the mixing layer were constructed. The mesoscale dry regions observed throughout the mixing layer correspond to the more impervious surfaces of the urban area. From energy budget considerations, latent heat fluxes are small over these impervious surfaces owing to the large runoff of precipitation and the lack of moisture retention capabilities. Hence, urbanization obviously alters the local energy budget. Surface boundary layer conditions are determined by heat and moisture fluxes. A new internal boundary layer within the city is formed after the breakdown of the radiation inversion in order to compensate for the alteration of sensible heat and latent heat energies. Hence, isolated semistagnant urban air is replenished by moisture only as quickly as evapotranspiration from impervious surfaces will allow. The city surface, therefore, is not a sink of moisture, but rather a reduced source relative to rural areas

Urban household energy consumption in Thailand

Energy Technology Data Exchange (ETDEWEB)

Pongsapich, Amara; Wongsekiarttirat, Wathana (Chulalongkorn Univ., Bangkok (Thailand). Social Research Inst.)

1994-05-01

This study was aimed at developing a better understanding of urban household energy consumption in Thailand through a series of in-depth household energy surveys. Households in urban areas used electricity, LPG, charcoal and fuelwood. Traditional biomass fuels such as husk and dung, as well as kerosene, were essentially not used in urban households. Nearly all households used electricity and most households used LPG. Some households used more than one fuel for cooking, particularly LPG and charcoal. There was a great difference in electricity used between the households in Bangkok and other urban areas. Most households in the study areas used LPG stove or burners for cooking. But charcoal stoves were also used by many households for specific culinary purposes. Electric rice-cookers are widely used for convenience. The study suggests that the number of households using charcoal stoves will decrease gradually and fuelwood use will disappear. Saturation rates for refrigerators and colour television sets were very high and air conditioners were common in Bangkok. Some users may be unaware of the benefits of LPG as a cooking fuel. To improve indoor air quality and cooking safety and reduce pressures on forests from commercial fuelwood use, measures to promote LPG should be undertaken. The government should also provide information about efficient appliances and electricity conservation. (Author)

The Power of Micro Urban Structures, Theory of EEPGC - the Micro Urban Energy Distribution Model as a Planning Tool for Sustainable City Development

Directory of Open Access Journals (Sweden)

Tkáč Štefan

2015-11-01

Full Text Available To achieve the smart growth and equitable development in the region, urban planners should consider also lateral energies represented by the energy urban models like further proposed EEPGC focused on energy distribution via connections among micro-urban structures, their onsite renewable resources and the perception of micro-urban structures as decentralized energy carriers based on pre industrialized era. These structures are still variously bound when part of greater patterns. After the industrial revolution the main traded goods became energy in its various forms. The EEPGC is focused on sustainable energy transportation distances between the villages and the city, described by the virtual “energy circles”. This more human scale urbanization, boost the economy in micro-urban areas, rising along with clean energy available in situ that surely gives a different perspective to human quality of life in contrast to overcrowded multicultural mega-urban structures facing generations of problems and struggling to survive as a whole.

The Power of Micro Urban Structures, Theory of EEPGC - the Micro Urban Energy Distribution Model as a Planning Tool for Sustainable City Development

Science.gov (United States)

Tkáč, Štefan

2015-11-01

To achieve the smart growth and equitable development in the region, urban planners should consider also lateral energies represented by the energy urban models like further proposed EEPGC focused on energy distribution via connections among micro-urban structures, their onsite renewable resources and the perception of micro-urban structures as decentralized energy carriers based on pre industrialized era. These structures are still variously bound when part of greater patterns. After the industrial revolution the main traded goods became energy in its various forms. The EEPGC is focused on sustainable energy transportation distances between the villages and the city, described by the virtual "energy circles". This more human scale urbanization, boost the economy in micro-urban areas, rising along with clean energy available in situ that surely gives a different perspective to human quality of life in contrast to overcrowded multicultural mega-urban structures facing generations of problems and struggling to survive as a whole.

Influence of urban resilience measures in the magnitude and behaviour of energy fluxes in the city of Porto (Portugal) under a climate change scenario

International Nuclear Information System (INIS)

Rafael, S.; Martins, H.; Sá, E.; Carvalho, D.; Borrego, C.; Lopes, M.

2016-01-01

Different urban resilience measures, such as the increase of urban green areas and the application of white roofs, were evaluated with the WRF-SUEWS modelling system. The case study consists of five heat waves occurring in Porto (Portugal) urban area in a future climate scenario. Meteorological forcing and boundary data were downscaled for Porto urban area from the CMIP5 earth system model MPI-ESM, for the Representative Concentration Pathway RCP8.5 scenario. The influence of different resilience measures on the energy balance components was quantified and compared between each other. Results show that the inclusion of green urban areas increases the evaporation and the availability of surface moisture, redirecting the energy to the form of latent heat flux (maximum increase of + 200 W m"−"2) rather than to sensible heat. The application of white roofs increases the solar radiation reflection, due to the higher albedo of such surfaces, reducing both sensible and storage heat flux (maximum reductions of − 62.8 and − 35 W m"−"2, respectively). The conjugations of the individual benefits related to each resilience measure shows that this measure is the most effective one in terms of improving the thermal comfort of the urban population, particularly due to the reduction of both sensible and storage heat flux. The obtained results contribute to the knowledge of the surface-atmosphere exchanges and can be of great importance for stakeholders and decision-makers. - Graphical abstract: A combination of white roofs and increased green urban areas has the potential do reduce the sensible heat flux of urban areas, being of great effectiveness in improving the thermal comfort of the urban population under future climate. - Highlights: • Evaluation of energy fluxes behaviour under RCP8.5 climate change scenario • Increase in the frequency, duration and magnitude of severe heat waves • Cities must become resilient to be able to deal with climate change �

Urban Consortium Energy Task Force - Year 21 Final Report

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-04-01

The Urban Consortium Energy Task Force (UCETF), comprised of representatives of large cities and counties in the United States, is a subgroup of the Urban Consortium, an organization of the nation's largest cities and counties joined together to identify, develop and deploy innovative approaches and technological solutions to pressing urban issues.

Complex assessment of urban housing energy sustainability

Science.gov (United States)

Popova, Olga; Glebova, Julia; Karakozova, Irina

2018-03-01

The article presents the results of a complex experimental-analytical research of residential development energy parameters - survey of construction sites and determination of calculated energy parameters (resistance to heat transfer) considering their technical condition. The authors suggest a methodology for assessing residential development energy parameters on the basis of construction project's structural analysis with the use of advanced intelligent collection systems, processing (self-organizing maps - SOM) and data visualization (geo-informational systems - GIS). SOM clustering permitted to divide the housing stock (on the example of Arkhangelsk city) into groups with similar technical-operational and energy parameters. It is also possible to measure energy parameters of construction project of each cluster by comparing them with reference (normative) measures and also with each other. The authors propose mechanisms for increasing the area's energy stability level by implementing a set of reproduction activities for residential development of various groups. The analysis showed that modern multilevel and high-rise construction buildings have the least heat losses. At present, however, ow-rise wood buildings is the dominant styles of buildings of Arkhangelsk city. Data visualisation on the created heat map showed that such housing stock covers the largest urban area. The development strategies for depressed areas is in a high-rise building, which show the economic, social and environmental benefits of upward growth of the city. An urban regeneration programme for severely rundown urban housing estates is in a high-rise construction building, which show the economic, social and environmental benefits of upward growth of the city.

Urban Greening as part ofDistrict Energy Services

OpenAIRE

MELIN, Sébastien

2017-01-01

Work carried out during this master’s thesis is about urban greening and its close integration with district energy systems. Urban greening is the fact to develop green infrastructures (parks, street trees, ...) instead of grey infrastructures (buildings, roads, ...) in cities. Despite that the actual economic value of green infrastructure is less appreciated at first glance and very difficult to valorize, urban greening has many undeniable advantages such as reducing pollution and heat islan...

Residential energy consumption in urban China: A decomposition analysis

International Nuclear Information System (INIS)

Zhao Xiaoli; Li Na; Ma, Chunbo

2012-01-01

Residential energy consumption (REC) is the second largest energy use category (10%) in China and urban residents account for 63% of the REC. Understanding the underlying drivers of variations of urban REC thus helps to identify challenges and opportunities and provide advices for future policy measures. This paper applies the LMDI method to a decomposition of China's urban REC during the period of 1998–2007 at disaggregated product/activity level using data collected from a wide range of sources. Our results have shown an extensive structure change towards a more energy-intensive household consumption structure as well as an intensive structure change towards high-quality and cleaner energy such as electricity, oil, and natural gas, which reflects a changing lifestyle and consumption mode in pursuit of a higher level of comfort, convenience and environmental protection. We have also found that China's price reforms in the energy sector have contributed to a reduction of REC while scale factors including increased urban population and income levels have played a key role in the rapid growth of REC. We suggest that further deregulation in energy prices and regulatory as well as voluntary energy efficiency and conservation policies in the residential sector should be promoted. - Highlights: ► We examine china's residential energy consumption (REC) at detailed product level. ► Results show significant extensive and intensive structure changed. ► Price deregulation in the energy sector has contributed a reduction of REC. ► Growth of population and income played a key role in REC rapid growth. ► We provide policy suggestions to promote REC saving.

Sustainable urban energy planning: A strategic approach to meeting climate and energy goals

Energy Technology Data Exchange (ETDEWEB)

Dobriansky, Larisa

2010-09-15

Meeting our 21st century challenges will require sustainable energy planning by our cities, where over half of the population resides. This already has become evident in the State of California, which has set rigorous greenhouse gas emission reduction targets and timeframes. To attain these targets will necessitate technically-integrated and cost-optimum solutions for innovative asset development and management within urban communities. Using California as a case study, this paper focuses on the crucial role for sustainable energy planning in creating the context and conditions for integrating and optimizing clean and efficient energy use with the urban built environment and infrastructure.

Household pathway selection of energy consumption during urbanization process in China

International Nuclear Information System (INIS)

Sun, Chuanwang; Ouyang, Xiaoling; Cai, Hongbo; Luo, Zhichao; Li, Aijun

2014-01-01

Highlights: • Energy consumption patterns have long-term impacts on energy demand. • We explore determinants and structure of household energy consumption. • Tobit and OLS models are adopted to explore factors influencing energy expenditure. • Residential energy consumption in 2030 is evaluated using scenario analysis. - Abstract: China’s growing energy demand is driven by urbanization. Facing the problem of energy scarcity, residential energy consumption is a crucial area of energy conservation and emissions reduction. Household energy consumption patterns, which are characterized by effects of “path lock-in”, have long-term impacts on China’s energy demand. Based on the survey data, this paper explores factors that influence household energy consumption and analyzes the structure of residential energy consumption in China. Based on the results of analysis of variance (ANOVA), this paper applies the Tobit and Ordinary Least Squares (OLS) models to investigate impacts of variables of “the tiered pricing for household electricity (TPHE)”, “solar energy usage”, “automobile ownership”, “rural or urban areas”, “household income” and “city scale” on the residential energy expenditure. In addition, household energy consumption is estimated under different scenarios including improving the utilization of solar energy, rise in energy prices and the increase in automobile ownership. Residential energy consumption in 2030 is evaluated by simulating different models for urban development. Policy recommendations are suggested for China’s urban development strategy, new energy development and household pathway selection of energy consumption

A brief history and the possible future of urban energy systems

International Nuclear Information System (INIS)

Rutter, Paul; Keirstead, James

2012-01-01

Modern cities depend on energy systems to deliver a range of services such as heating, cooling, lighting, mobility, communications, and so on. This article examines how these urban energy systems came to be, tracing the major transitions from the earliest settlements through to today's fossil-fuelled cities. The underlying theme is “increasing efficiency under constraints” with each transition marked by increasing energy efficiency in service provision, increasing per capita energy use, increasing complexity in the energy system's structure, with innovations driven by a strategic view of the overall system, and accompanied by wider changes in technology and society. In developed countries, the future of urban energy systems is likely to continue many of these trends, with increased efficiency being driven by the constraints of climate change and rising fuel prices. Both supply and demand side technologies are discussed as potential solutions to these issues, with different impacts on the urban environment and its citizens. However in developing countries, rising urban populations and access to basic energy services will drive the next transition. - Highlights: ► Urban energy system transitions in history are reviewed. ► Common features include increased per capita energy use, growing system complexity, and technological innovation. ► Future transitions will be shaped by the constraints of climate change, rising fuel prices, and urbanisation. ► Long-term sustainability depends on ability to innovate rapidly; opportunities exist on supply and demand sides.

Potential Impact of Rainfall on the Air-Surface Exchange of Total Gaseous Mercury from Two Common Urban Ground Surfaces

Science.gov (United States)

The impact of rainfall on total gaseous mercury (TGM) flux from pavement and street dirt surfaces was investigated in an effort to determine the influence of wet weather events on mercury transport in urban watersheds. Street dirt and pavement are common urban ground surfaces tha...

Mineralogical and geochemical patterns of urban surface soils, the example of Pforzheim, Germany

International Nuclear Information System (INIS)

Norra, Stefan; Lanka-Panditha, Mahesh; Kramar, Utz; Stueben, Doris

2006-01-01

This study presents a combined geochemical and mineralogical survey of urban surface soils. Many studies on urban soils are restricted to purely chemical surveys in order to investigate soil pollution caused by anthropogenic activities such as traffic, heating, industrial processing, waste disposal and many more. In environmental studies, chemical elements are often distinguished as lithogenic and anthropogenic elements. As a novel contribution to those studies, the authors combined the analysis of a broad set of chemical elements with the analysis of the main mineralogical phases. The semi-quantification of mineralogical phases supported the assignment of groups of chemical elements to lithogenic or anthropogenic origin. Minerals are important sinks for toxic elements. Thus, knowledge about their distribution in soils is crucial for the assessment of the environmental hazards due to pollution of urban soils. In Pforzheim, surface soils (0-5 cm depth) from various land use types (forest, agriculture, urban green space, settlement areas of various site densities) overlying different geological units (clastic and chemical sediments) were investigated. Urban surface soils of Pforzheim reflect to a considerable degree the mineral and chemical composition of parent rocks. Irrespective of the parent rocks, elevated concentrations of heavy metals (Zn, Cu, Pb, Sn, Ag) were found in soils throughout the whole inner urban settlement area of Pforzheim indicating pollution. These pollutants will tend to accumulate in inner urban surface soils according to the available adsorption capacity, which is normally higher in soils overlying limestone than in soils overlying sandstone. However, inner urban surface soils overlying sandstone show elevated concentrations of carbonates, phyllo-silicates and Fe and elevated pH values compared with forest soils overlying sandstone. Thus, in comparison to forest soils overlying sandstones, inner urban soils overlying sandstone affected by

Dynamics of the Urban Water-Energy Nexuses of Mumbai and London

Science.gov (United States)

De Stercke, S.; Mijic, A.; Buytaert, W.; Chaturvedi, V.

2016-12-01

Both in developing as well as industrialized countries, cities are seeing their populations increase as more people concentrate in urban settlements. This burdens existing water and energy systems, which are also increasingly stressed on the supply side due to availability, and policy goals. In addition to the water and energy embedded in the electricity, fuels and water delivered to the city, the linkages in the urban environment itself are important and in magnitude they significantly exceed those upstream in the case of industrialized countries. However, little research has been published on urban water-energy linkages in developing countries. For cities in general, there is also a dearth of studies on the dynamics of these linkages with urban growth and socioeconomic development, and hence of the mutual influence of the urban water and energy systems. System dynamics modeling was used to understand and simulate these dynamics, building on modeling techniques from the water, energy, and urban systems literature. For each of the two characteristically different cities of Mumbai and London a model was constructed and calibrated with data from various public sources and personal interviews. The differences between the two cases are discussed by means of the models. Transition pathways to sustainable cities with respect to water use, energy use and greenhouse gas emissions are illustrated for each city. Furthermore, uncertainties and model sensitivity, and their implications, are presented. Finally, applicability of either or a hybrid of these models to other cities is investigated.

Making cities energy efficient. Urban and regional planning adopting RES

Energy Technology Data Exchange (ETDEWEB)

Ahonen, A.-M.; David, T.; Dorfner, J. [and others

2013-06-01

This report summarises the outcomes of a 30 months duration continuing education project entitled 'Urban Planners with Renewable Energy Skills' (UP-RES). The project was carried out by a multi-disciplinary international consortium with the aim of informing planners and related professionals about energy-efficient and CO{sub 2} reducing technologies, practices and systems that can be developed across urban areas to serve whole communities. This report provides an overview of the key issues: The overall project approach to devising a training program based on preceding training needs analysis The key tasks involved in creating the training materials The marketing of the training as well as evaluation results Best practise examples of RES in urban planning. The UP-RES project has focused on several major target groups. These include those groups directly involved in taking forward renewable energy projects for whom the UP-RES training was principally focused; those who wish to deliver such training programmes; and policy makers who are ultimately responsible for the decisions that govern how widely such technologies will be implemented. Each of these groups has its own perspective concerning renewable energy technologies so the report is structured accordingly: For professionals involved in implementation: Among those professions that are likely to become involved with renewable energy initiatives in urban areas are urban planners, architects, energy suppliers, developers, building owners, and consulting engineers. For these professionals chapters 3.2 (summary of training need analysis) and 4 (best practise examples) are most likely to appeal. For training experts and organisations: Training programmes that address the relevance of renewable energies in urban areas require a comprehensive set of materials. As an example of how to organise training courses and lessons learnt, chapter 3 might be interesting. For the generally interested: Renewable energies are

Energy and sustainable urban transport development in China: Challenges and solutions

International Nuclear Information System (INIS)

Zhang, Xilang; Hu, Xiaojun

2002-01-01

This paper presents an overview of urban road transport development and challenges in energy consumption in China. It relates sustainable urban road transport development with energy consumption and environmental management. It analyzes the main challenges related to urban road transport development: energy security, low efficiency in energy utilization, and unsustainable environmental management. It also discusses necessary technological and policy initiatives to deal with these challenges: e.g., promoting the development and dissemination of cleaner vehicle technologies, substitution of LPG, CNG, LNG and bio fuels for gasoline and diesel, strengthening regulations on vehicle emissions, expediting public transport development, and the effective management of the soaring private cars. (author)

Energy and sustainable urban transport development in China: Challenges and solutions

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xilang; Hu, Xiaojun

2002-07-01

This paper presents an overview of urban road transport development and challenges in energy consumption in China. It relates sustainable urban road transport development with energy consumption and environmental management. It analyzes the main challenges related to urban road transport development: energy security, low efficiency in energy utilization, and unsustainable environmental management. It also discusses necessary technological and policy initiatives to deal with these challenges: e.g., promoting the development and dissemination of cleaner vehicle technologies, substitution of LPG, CNG, LNG and bio fuels for gasoline and diesel, strengthening regulations on vehicle emissions, expediting public transport development, and the effective management of the soaring private cars. (author)

Panel estimation for urbanization, energy consumption and CO2 emissions: A regional analysis in China

International Nuclear Information System (INIS)

Zhang Chuanguo; Lin Yan

2012-01-01

As urbanization accelerates, urban areas play a leading role in energy consumption and CO 2 emissions in China. The existing research is extensively concerned with the relationships between urbanization, energy consumption and CO 2 emissions in recent years, but little attention has been paid to the regional differences. This paper is an analysis of the impact of urbanization on energy consumption and CO 2 emissions at the national and regional levels using the STIRPAT model and provincial panel data from 1995 to 2010 in China. The results showed that urbanization increases energy consumption and CO 2 emissions in China. The effects of urbanization on energy consumption vary across regions and decline continuously from the western region to the central and eastern regions. The impact of urbanization on CO 2 emissions in the central region is greater than that in the eastern region. The impact of urbanization on energy consumption is greater than the impact on CO 2 emissions in the eastern region. And some evidences support the argument of compact city theory. These results not only contribute to advancing the existing literature, but also merit particular attention from policy makers and urban planners in China. - Highlights: ► We analyze the impact of urbanization on energy use and CO 2 emissions in China. ► Urbanization increases energy consumption and CO 2 emissions in China. ► The effects of urbanization on energy use and CO 2 emissions vary across regions.

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

Energy Technology Data Exchange (ETDEWEB)

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

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 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.

Synergies and trade-offs between energy-efficient urbanization and health

Science.gov (United States)

Ahmad, Sohail; Pachauri, Shonali; Creutzig, Felix

2017-11-01

Energy-efficient urbanization and public health pose major development challenges for India. While both issues are intensively studied, their interaction is not well understood. Here we explore the relationship between urban infrastructures, public health, and household-related emissions, identifying potential synergies and trade-offs of specific interventions by analyzing nationally representative household surveys from 2005 and 2012. Our analysis confirms previous characterizations of the environmental-health transition, but also points to an important role of energy use and urbanization as modifiers of this transition. We find that non-motorized transport may prove a sweet spot for development, as its use is associated with lower emissions and better public health in cities. Urbanization and improved access to basic services correlate with lower short-term morbidity (STM), such as fever, cough and diarrhea. Our analysis suggests that a 10% increase in urbanization from current levels and concurrent improvement in access to modern cooking and clean water could lower STM for 2.4 million people. This would be associated with a modest increase in electricity related emissions of 84 ktCO2e annually. Promoting energy-efficient mobility systems, for instance by a 10% increase in bicycling, could lower chronic conditions like diabetes and cardio-vascular diseases for 0.3 million people while also abating emissions. These findings provide empirical evidence to validate that energy-efficient and sustainable urbanization can address both public health and climate change challenges simultaneously.

Contrasting effects of urbanization and agriculture on surface temperature in eastern China

Science.gov (United States)

Decheng Zhou; Dan Li; Ge Sun; Liangxia Zhang; Yongqiang Liu; Lu Hao

2016-01-01

The combined effect of urbanization and agriculture, two most pervasive land use activities, on the surface climate remains poorly understood. Using Moderate Resolution Imaging Spectroradiometer data over 2010–2015 and forests as reference, we showed that urbanization warmed the land surface temperature (LST), especially during the daytime and in growing seasons (...

Energy performance of areas for urban development (Arkhangelsk is given as example)

Science.gov (United States)

Popova, Olga; Glebova, Yulia

2017-01-01

The present research provides an overview and analysis of the legal framework and the technology to increase energy save and energy efficiency. The challenges of the mentioned activities implementation in urban areas are revealed in the paper. A comparison was made of the principal methods of increasing energy efficiency that is based on payback period. The basic shortcomings of the methods used are found. The way of capital reproducing assets acquisition is proposed with consideration of the rate of wear and tear and upgrading of urban residential development. The present research aims at characterizing energy sustainability of urban areas for forming the information basis that identifies capital construction projects together within the urban area. A new concept - area energy sustainability is introduced in the study to use system-structural approach to energy saving and energy efficiency. Energy sustainability of the area as an integral indicator of the static characteristics of the territory is considered as a complex involving the following terms: energy security, energy intensity and energy efficiency dynamic indicators of all the components of the power system of the area. Dimensions and parameters of energy sustainability of the area are determined. Arkhangelsk is given as example.

Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with the TEB model

Science.gov (United States)

Khalifa, A.; Marchetti, M.; Bouilloud, L.; Martin, E.; Bues, M.; Chancibaut, K.

2016-02-01

Snowfall forecasts help winter maintenance of road networks, ensure better coordination between services, cost control, and a reduction in environmental impacts caused by an inappropriate use of de-icers. In order to determine the possible accumulation of snow on pavements, forecasting the road surface temperature (RST) is mandatory. Weather outstations are used along these networks to identify changes in pavement status, and to make forecasts by analyzing the data they provide. Physical numerical models provide such forecasts, and require an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB) numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with two approaches to evaluate traffic incidence on RST. Experiments were then conducted to measure the effect of traffic on RST increase with respect to non-circulated areas. These field data were then used for comparison with the forecast provided by this traffic-implemented TEB version.

Citywide Impacts of Cool Roof and Rooftop Solar Photovoltaic Deployment on Near-Surface Air Temperature and Cooling Energy Demand

Science.gov (United States)

Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Martilli, A.

2016-10-01

Assessment of mitigation strategies that combat global warming, urban heat islands (UHIs), and urban energy demand can be crucial for urban planners and energy providers, especially for hot, semi-arid urban environments where summertime cooling demands are excessive. Within this context, summertime regional impacts of cool roof and rooftop solar photovoltaic deployment on near-surface air temperature and cooling energy demand are examined for the two major USA cities of Arizona: Phoenix and Tucson. A detailed physics-based parametrization of solar photovoltaic panels is developed and implemented in a multilayer building energy model that is fully coupled to the Weather Research and Forecasting mesoscale numerical model. We conduct a suite of sensitivity experiments (with different coverage rates of cool roof and rooftop solar photovoltaic deployment) for a 10-day clear-sky extreme heat period over the Phoenix and Tucson metropolitan areas at high spatial resolution (1-km horizontal grid spacing). Results show that deployment of cool roofs and rooftop solar photovoltaic panels reduce near-surface air temperature across the diurnal cycle and decrease daily citywide cooling energy demand. During the day, cool roofs are more effective at cooling than rooftop solar photovoltaic systems, but during the night, solar panels are more efficient at reducing the UHI effect. For the maximum coverage rate deployment, cool roofs reduced daily citywide cooling energy demand by 13-14 %, while rooftop solar photovoltaic panels by 8-11 % (without considering the additional savings derived from their electricity production). The results presented here demonstrate that deployment of both roofing technologies have multiple benefits for the urban environment, while solar photovoltaic panels add additional value because they reduce the dependence on fossil fuel consumption for electricity generation.

Spatial Variation and Distribution of Urban Energy Consumptions from Cities in China

Directory of Open Access Journals (Sweden)

Yanpeng Cai

2010-12-01

Full Text Available With support of GIS tools and Theil index, the spatial variance of urban energy consumption in China was discussed in this paper through the parallel comparison and quantitative analysis of the 30 provincial capital cities of mainland China in 2005, in terms of scale, efficiency and structure. The indicators associated with urban energy consumption show large spatial variance across regions, possibly due to diversities of geographic features, economic development levels and local energy source availability in China. In absolute terms, cities with the highest total energy consumption are mostly distributed in economic-developed regions as Beijing-Tianjin-Tangshan Area, Yangtze River Delta and Pearl River Delta of China, however, the per capita urban energy use is significantly higher in the Mid-and-Western regions. With regard to the energy mix, coal still plays the dominant role and cities in Mid-and-Western regions rely more on coal. In contrast, high quality energy carrier as electricity and oils are more used in southeast coastal zone and northern developed areas. The energy intensive cities are mainly located in the northwest, while the cities with higher efficiency are in southeast areas. The large spatial variance of urban energy consumption was also verified by the Theil indices. Considering the Chinese economy-zones of East, Middle and West, the within-group inequalities are the main factor contributing to overall difference, e.g., the Theil index for per capita energy consumption of within-group is 0.18, much higher than that of between group (0.07, and the same applies to other indicators. In light of the spatial variance of urban energy consumptions in China, therefore, regionalized and type-based management of urban energy systems is badly needed to effectively address the ongoing energy strategies and targets.

The Influence of Roof Material on Diurnal Urban Canyon Breathing

Science.gov (United States)

Abuhegazy, Mohamed; Yaghoobian, Neda

2017-11-01

Improvements in building energy use, air quality in urban canyons and in general urban microclimates require understanding the complex interaction between urban morphology, materials, climate, and inflow conditions. Review of the literature indicates that despite a long history of valuable urban microclimate studies, more comprehensive approaches are needed to address energy, and heat and flow transport in urban areas. In this study, a more comprehensive simulation of the diurnally varying street canyon flow and associated heat transport is numerically investigated, using Large-eddy Simulation (LES). We use computational modeling to examine the impact of diurnal variation of the heat fluxes from urban surfaces on the air flow and temperature distribution in street canyons with a focus on the role of roof materials and their temperature footprints. A detailed building energy model with a three-dimensional raster-type geometry provides urban surface heat fluxes as thermal boundary conditions for the LES to determine the key aero-thermodynamic factors that affect urban street ventilation.

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

Science.gov (United States)

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.

Understanding the behavior of carbon dioxide and surface energy fluxes in semiarid Salt Lake Valley, Utah, USA

Science.gov (United States)

Ramamurthy, Prathap

This dissertation reports the findings from the Salt Lake Valley flux study. The Salt Lake Valley flux study was designed to improve our understanding of the complex land-atmosphere interactions in urban areas. The flux study used the eddy covariance technique to quantify carbon dioxide and surface energy budget in the semiarid Salt Lake Valley. Apart from quantifying fluxes, the study has also added new insight into the nature of turbulent scalar transport in urban areas and has addressed some of the complications in using Eddy Covariance technique in urban areas. As part of this experiment, eddy fluxes of CO2 and surface energy fluxes were measured at two sites, with distinct urban landforms; One site was located in a suburban neighborhood with substantial vegetative cover, prototypical of many residential neighborhoods in the valley. The other CO2 site was in a preurban surrounding that resembled the Salt Lake Valley before it was urbanized. The two sites were intentionally chosen to illustrate the impact of urbanization on CO 2 and surface energy flux cycles. Results indicate that the suburban site acted as a sink of CO2 during the midday period due to photosynthesis and acted as a source of CO2 during the evening and nighttime periods. The vegetative cover around the suburban site also had a significant impact on the surface energy fluxes. Contribution from latent heat flux was substantially high at the suburban site during the summer months compared to sensible heat. The turbulence investigation found that the general behavior of turbulence was very much influenced by local factors and the statistics did not always obey Monin-Obukhov Similarity parameters. This investigation also found that the scalar (co)spectra observed at the suburban site were characterized by multiple peaks and were different compared to (co)spectra reported over forest and crop canopies. The study also observed multiscale CO2 transport at the suburban site during the convective period

Influence of urban resilience measures in the magnitude and behaviour of energy fluxes in the city of Porto (Portugal) under a climate change scenario

Energy Technology Data Exchange (ETDEWEB)

Rafael, S., E-mail: sandra.rafael@ua.pt; Martins, H.; Sá, E.; Carvalho, D.; Borrego, C.; Lopes, M.

2016-10-01

Different urban resilience measures, such as the increase of urban green areas and the application of white roofs, were evaluated with the WRF-SUEWS modelling system. The case study consists of five heat waves occurring in Porto (Portugal) urban area in a future climate scenario. Meteorological forcing and boundary data were downscaled for Porto urban area from the CMIP5 earth system model MPI-ESM, for the Representative Concentration Pathway RCP8.5 scenario. The influence of different resilience measures on the energy balance components was quantified and compared between each other. Results show that the inclusion of green urban areas increases the evaporation and the availability of surface moisture, redirecting the energy to the form of latent heat flux (maximum increase of + 200 W m{sup −2}) rather than to sensible heat. The application of white roofs increases the solar radiation reflection, due to the higher albedo of such surfaces, reducing both sensible and storage heat flux (maximum reductions of − 62.8 and − 35 W m{sup −2}, respectively). The conjugations of the individual benefits related to each resilience measure shows that this measure is the most effective one in terms of improving the thermal comfort of the urban population, particularly due to the reduction of both sensible and storage heat flux. The obtained results contribute to the knowledge of the surface-atmosphere exchanges and can be of great importance for stakeholders and decision-makers. - Graphical abstract: A combination of white roofs and increased green urban areas has the potential do reduce the sensible heat flux of urban areas, being of great effectiveness in improving the thermal comfort of the urban population under future climate. - Highlights: • Evaluation of energy fluxes behaviour under RCP8.5 climate change scenario • Increase in the frequency, duration and magnitude of severe heat waves • Cities must become resilient to be able to deal with climate change �

Evaluating Cool Impervious Surfaces: Application to an Energy-Efficient Residential Roof and to City Pavements

Science.gov (United States)

Rosado, Pablo Javier

Summer urban heat island (UHI) refers to the phenomenon of having higher urban temperatures compared to the those in surrounding suburban and rural areas. Higher urban air temperatures lead to increased cooling demand, accelerates the formation of smog, and contributes to the generation of greenhouse gas emissions. Dark-colored impervious surfaces cover a significant fraction of an urban fabric, and as hot and dry surfaces, are a major contributor to the UHI effect. Adopting solar-reflective ("cool") roofs and cool pavements, and increasing the urban vegetation, are strategies proven to mitigate urban heat islands. These strategies often have an "indirect" effect (ambient cooling) and "direct" effect (change in solar energy flux entering the conditioned space) on the energy use of buildings. This work investigates some elements of the UHI mitigation strategies, specifically the annual direct effect of a cool roof, and the direct and indirect effects of cool pavements. The first topic researched in this paper consists in an experimental assessment of the direct effects from replacing a conventional dark roof with a highly energy-efficient cool roof. The study measures and calculates the annual benefits of the cool roof on the cooling and heating energy uses, and the associated emission reductions. The energy savings attributed to the cool roof are validated by measuring the difference between the homes in the heat loads that entered the conditioned space through the ceiling and HVAC ducts. Fractional annual cooling energy savings (26%) were 2.6 times the 10% daily cooling energy savings measured in a previous study that used a white coating to increase the albedo of an asphalt shingle roof by the same amount (0.44). The improved cooling energy savings (26% vs. 10%) may be attributed to the cool tile's above-sheathing ventilation, rather than to its high thermal mass. The roof also provided energy savings during the heating season, yielding fractional annual gas

Mitigating the surface urban heat island: Mechanism study and sensitivity analysis

Science.gov (United States)

Meng, Chunlei

2017-08-01

In a surface urban heat island (SUHI), the urban land surface temperature (LST) is usually higher than the temperature of the surrounding rural areas due to human activities and surface characteristics. Because a SUHI has many adverse impacts on urban environment and human health, SUHI mitigation strategies are very important. This paper investigates the mechanism of a SUHI based on the basic physical laws that control the formation of a SUHI; five mitigation strategies are proposed, namely: sprinkling and watering; paving a pervious surface; reducing the anthropogenic heat (AH) release; using a "white roof"; increasing the fractional vegetation cover or leaf area index (LAI). To quantify the effect of these mitigation strategies, 26 sets of experiments are designed and implemented by running the integrated urban land model (IUM). The results of the sensitivity analysis indicate that sprinkling and watering is an effective measure for mitigating a SUHI for an entire day. Decreasing the AH release is also useful for both night- and daytime SUHI mitigation; however, the cooling extent is proportional to the diurnal cycle of AH. Increasing the albedo can reduce the LST in the daytime, especially when the solar radiation is significant; the cooling extent is approximately proportional to the diurnal cycle of the net radiation. Increasing the pervious surface percentage can mitigate the SUHI especially in the daytime. Increasing the fractional vegetation cover can mitigate the SUHI in the daytime but may aggravate the SUHI at night.

Smartness and Urban Resilience. A Model of Energy Saving

Directory of Open Access Journals (Sweden)

Carmela Gargiulo

2015-10-01

The results have shown that the possibility of identifying an "ideal" sustainable urban form, able to maximize energy efficiency, still remains theoretical, opening up the possibility that there are different consumption patterns due to the different physical, environmental and building characteristics of urban areas.

The Effects of Domestic Energy Consumption on Urban Development Using System Dynamics

Science.gov (United States)

Saryazdi, M. D.; Homaei, N.; Arjmand, A.

2018-05-01

In developed countries, people have learned to follow efficient consumption patterns, while in developing countries, such as Iran, these patterns are not well executed. A large amount of energy is almost consumed in buildings and houses and though the consumption patterns varies in different societies, various energy policies are required to meet the consumption challenges. So far, several papers and more than ten case studies have worked on the relationship between domestic energy consumption and urban development, however these researches did not analyzed the impact of energy consumption on urban development. Therefore, this paper attempts to examine the interactions between the energy consumption and urban development by using system dynamics as the most widely used methods for complex problems. The proposed approach demonstrates the interactions using causal loop and flow diagrams and finally, suitable strategies will be proposed for urban development through simulations of different scenarios.

Recovery of energetically overexploited urban aquifers using surface water

Science.gov (United States)

García-Gil, Alejandro; Vázquez-Suñé, Enric; Sánchez-Navarro, José Ángel; Mateo Lázaro, Jesús

2015-12-01

Shallow aquifers have an important role in reducing greenhouse gases through helping manage the temperature of urban environments. Nevertheless, the uncontrolled rapid use of shallow groundwater resources to heat or cool urban environments can cause thermal pollution that will limit the long term sustainability of the resource. Therefore, there is a need for appropriate mitigation/remediation strategies capable of recovering energetically overexploited aquifers. In this work, a novel remediation strategy based on surface water recharge into aquifers is presented. To evaluate the capabilities of such measures for effective remediation, this strategy is optimized for a management problem raised in the overheated "Urban Alluvial Aquifer of Zaragoza" (Spain). The application of a transient groundwater flow and heat transport model under 512 different mitigation scenarios has enabled to quantify and discuss the magnitude of the remediation effect as a respond to injection rates of surface water, seasonal schedule of the injection and location of injection. The quantification of the relationship between these variables together with the evaluation of the amount of surface water injected per year in each scenario proposed have provided a better understanding of the system processes and an optimal management alternative. This work also makes awareness of the magnitude of the remediation procedure which is in an order of magnitude of tenths of years.

Surface Energy and Setting Process of Contacting Surfaces

Directory of Open Access Journals (Sweden)

M. V. Musokhranov

2014-01-01

Full Text Available The paper deals with a challenge in terms of ensuring an accuracy of the relative position of the conjugated surfaces that is to determine a coefficient of friction. To solve it, there is a proposal to use the surface energy, as a tool that influences the contacting parts nature. Presently, energy of the surface layers at best is only stated, but not used in practice.Analysis of the conditions of interaction between two contacting surfaces, such as seizing and setting cannot be explained only from the position of the roughness parameters. It is found that these phenomena are explained by the appearing gripe (setting bridges, which result from the energy of interaction between two or more adjacent surfaces. The emerging phenomenon such as micro welding, i.e. occurring bonds, is caused by the overflow of energy, according to the theory of physics, from the surface with a high level of energy to the surface with the smaller one to balance the system as a whole.The paper shows that through the use of process, controlling the depth of the surface layer and creating a certain structure, the energy level of the material as a whole can be specified. And this will allow us to provide the necessary performance and mechanical properties. It means to create as many gripe bridges as possible to ensure continuous positioning i.e. a fixed connection of the contacting surfaces.It was determined that to increase a value of the friction coefficient, the physical and mechanical properties of the surface layer of the parts material must be taken into account, namely, in the part body accumulate the energy to be consumed for forming the surface.The paper gives recommendations for including the parts of the surface energy in the qualitative indicators of characteristics. This will make a technologist, when routing a process, to choose such operations and modes to provide the designer-specified parameters not only of the accuracy and surface finish, but also of the

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

Science.gov (United States)

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.

Associating Land Surface Temperature Retrieved From Satellite and Unmanned Aerial Vehicle Data With Urban Cover and Topography in Aburrá Valley

Science.gov (United States)

Guzmán, G.; Hoyos Ortiz, C. D.

2017-12-01

Urban heat island effect commonly refers to temperature differences between urban areas and their countrysides due to urbanization. These temperature differences are evident at surface, and within the canopy and the boundary layer. This effect is heterogeneous within the city, and responds to urban morphology, prevailing materials, amount of vegetation, among others, which are also important in the urban balance of energy. In order to study the relationship between land surface temperature (LST) and urban coverage over Aburrá Valley, which is a narrow valley locate at tropical Andes in northern South America, Landsat 8 mission products of LST, density of vegetation (normalized difference vegetation index, NDVI), and a proxy of soil humidity are derived and used. The results are analyzed from the point of view of dominant urban form and settlement density at scale of neighborhoods, and also from potential downward solar radiation received at the surface. Besides, specific sites were chosen to obtain LST from thermal imaging using an unmanned aerial vehicle to characterize micro-scale patterns and to validate Landast retrievals. Direct relationships between LST, NDVI, soil humidity, and duration of insolation are found, showing the impact of the current spatial distribution of land uses on surface temperature over Aburrá Valley. In general, the highest temperatures correspond to neighborhoods with large, flat-topped buildings in commercial and industrial areas, and low-rise building in residential areas with scarce vegetation, all on the valley bottom. Landsat images are in the morning for the Aburrá Valley, for that reason the coldest temperatures are prevalent at certain orientation of the hillslope, according with the amount of radiation received from sunrise to time of data.

Total pollution effect of urban surface runoff.

Science.gov (United States)

Luo, Hongbing; Luo, Lin; Huang, Gu; Liu, Ping; Li, Jingxian; Hu, Sheng; Wang, Fuxiang; Xu, Rui; Huang, Xiaoxue

2009-01-01

For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD (chemical oxygen demand), TSS (total suspend solid), TP (total phosphorus), TN (total nitrogen) and BOD (biochemical oxygen demand). The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters: rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 (mass first flush ratio) and FF30 (first 30% of runoff volume) can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs (best management practices) facilities.

3D modeling of satellite spectral images, radiation budget and energy budget of urban landscapes

Science.gov (United States)

Gastellu-Etchegorry, J. P.

2008-12-01

DART EB is a model that is being developed for simulating the 3D (3 dimensional) energy budget of urban and natural scenes, possibly with topography and atmosphere. It simulates all non radiative energy mechanisms (heat conduction, turbulent momentum and heat fluxes, water reservoir evolution, etc.). It uses DART model (Discrete Anisotropic Radiative Transfer) for simulating radiative mechanisms: 3D radiative budget of 3D scenes and their remote sensing images expressed in terms of reflectance or brightness temperature values, for any atmosphere, wavelength, sun/view direction, altitude and spatial resolution. It uses an innovative multispectral approach (ray tracing, exact kernel, discrete ordinate techniques) over the whole optical domain. This paper presents two major and recent improvements of DART for adapting it to urban canopies. (1) Simulation of the geometry and optical characteristics of urban elements (houses, etc.). (2) Modeling of thermal infrared emission by vegetation and urban elements. The new DART version was used in the context of the CAPITOUL project. For that, districts of the Toulouse urban data base (Autocad format) were translated into DART scenes. This allowed us to simulate visible, near infrared and thermal infrared satellite images of Toulouse districts. Moreover, the 3D radiation budget was used by DARTEB for simulating the time evolution of a number of geophysical quantities of various surface elements (roads, walls, roofs). Results were successfully compared with ground measurements of the CAPITOUL project.

Influence of urban resilience measures in the magnitude and behaviour of energy fluxes in the city of Porto (Portugal) under a climate change scenario.

Science.gov (United States)

Rafael, S; Martins, H; Sá, E; Carvalho, D; Borrego, C; Lopes, M

2016-10-01

Different urban resilience measures, such as the increase of urban green areas and the application of white roofs, were evaluated with the WRF-SUEWS modelling system. The case study consists of five heat waves occurring in Porto (Portugal) urban area in a future climate scenario. Meteorological forcing and boundary data were downscaled for Porto urban area from the CMIP5 earth system model MPI-ESM, for the Representative Concentration Pathway RCP8.5 scenario. The influence of different resilience measures on the energy balance components was quantified and compared between each other. Results show that the inclusion of green urban areas increases the evaporation and the availability of surface moisture, redirecting the energy to the form of latent heat flux (maximum increase of +200Wm(-2)) rather than to sensible heat. The application of white roofs increases the solar radiation reflection, due to the higher albedo of such surfaces, reducing both sensible and storage heat flux (maximum reductions of -62.8 and -35Wm(-2), respectively). The conjugations of the individual benefits related to each resilience measure shows that this measure is the most effective one in terms of improving the thermal comfort of the urban population, particularly due to the reduction of both sensible and storage heat flux. The obtained results contribute to the knowledge of the surface-atmosphere exchanges and can be of great importance for stakeholders and decision-makers. Copyright © 2016 Elsevier B.V. All rights reserved.

URBAN FEATURES AND ENERGY CONSUMPTION AT LOCAL LEVEL

Directory of Open Access Journals (Sweden)

Ali Soltani

2012-12-01

Full Text Available There has been a growing interest in discovering the human effects on the environment and energy consumption in recent decades. It is estimated that the share of energy consumed in transportation and housing systems are around 20 and 30 percent of total energy consumption respectively. Furthermore, the residential greenhouse emissions depend on urban form and structure. This paper explores the effects of urban features on residential energy consumption at neighborhood level using data collected through household questionnaire (n=140. Two residential districts in metropolitan Shiraz, south of Iran, were selected as case study areas. Different features of two areas were compared including building density, typology, housing location, parcel size, floor area and construction materials. Ordinary linear regression was used to discover the impact of explanatory variables on energy consumption. It was found that some physical variables such as parcel size, setback and number of floors played significant roles in explaining the variances exist in energy use level. The results can be used by governmental agencies to modify land use policies and subdivision rules in hope of saving energy and achieving a sustainable community.

Energy transition and urban ecological inequalities

International Nuclear Information System (INIS)

Hamman, Philippe; Christen, Guillaume

2017-01-01

This paper deals with social inequalities in the relationship to the environment, by looking at the capacity of actors to mobilize around renewable energy initiatives in the context of the energy transition. It is based on field surveys (qualitative and quantitative) on an urban scale, conducted between 2012 and 2015 in the metropolitan area of Strasbourg. We show that the emphasis on resident involvement masks the reality of rather prescriptive 'eco-innovations'; and that the differentiated relations of the inhabitants to the technical tools meant to materialize renewable energy reveal ecological inequalities that reinforce socio-economic division in the city

The State of U.S. Urban Water: Data and the Energy-Water Nexus

Science.gov (United States)

Chini, Christopher M.; Stillwell, Ashlynn S.

2018-03-01

Data on urban water resources are scarce, despite a majority of the U.S. population residing in urban environments. Further, information on the energy required to facilitate the treatment, distribution, and collection of urban water are even more limited. In this study, we evaluate the energy-for-water component of the energy-water nexus by providing and analyzing a unique primary database consisting of drinking water and wastewater utility flows and energy. These anthropogenic fluxes of water through the urban environment are used to assess the state of the U.S. urban energy-water nexus at over 160 utilities. The average daily per person water flux is estimated at 560 L of drinking water and 500 L of wastewater. Drinking water and wastewater utilities require 340 kWh/1,000 m3 and 430 kWh/1,000 m3 of energy, respectively, to treat these resources. The total national energy demand for water utilities accounts for 1.0% of the total annual electricity consumption of the United States. Additionally, the water and embedded energy loss associated with non-revenue water accounts for 9.1 × 109 m3 of water and 3,100 GWh, enough electricity to power 300,000 U.S. households annually. Finally, the water flux and embedded energy fluctuated monthly in many cities. As the nation's water resources become increasingly scarce and unpredictable, it is essential to have a set of empirical data for continuous evaluation and updates on the state of the U.S. urban energy-water nexus.

Framework for reports on urban energy planning in 6 case cities

DEFF Research Database (Denmark)

Fertner, Christian; Groth, Niels Boje; Große, Juliane

a general model for energy efficiency and sustainable city planning. By connecting scientific excellence and innovative enterprises in the energy sector with ambitious and well-organized cities, the project aims to reduce energy use in Europe in the near future and will therefore be an important tool...... on the case study reports (D4.2). The wider target group are other PLEEC partners who are interested in WP4’s work as well as other professionals who would like to get inspiration how to conduct an analysis of energy issues in relation to spatial planning and urban form in medium-sized cities. Five main...... chapters are suggested to follow in all case study reports: • Overview of city (geography, socio-economic, history, …) • Historical urban development and spatial planning development • Evolution of national and local energy planning • Management of urban planning and energy today • Pilot projects / good...

Modeling urban building energy use: A review of modeling approaches and procedures

Energy Technology Data Exchange (ETDEWEB)

Li, Wenliang; Zhou, Yuyu; Cetin, Kristen; Eom, Jiyong; Wang, Yu; Chen, Gang; Zhang, Xuesong

2017-12-01

With rapid urbanization and economic development, the world has been experiencing an unprecedented increase in energy consumption and greenhouse gas (GHG) emissions. While reducing energy consumption and GHG emissions is a common interest shared by major developed and developing countries, actions to enable these global reductions are generally implemented at the city scale. This is because baseline information from individual cities plays an important role in identifying economical options for improving building energy efficiency and reducing GHG emissions. Numerous approaches have been proposed for modeling urban building energy use in the past decades. This paper aims to provide an up-to-date review of the broad categories of energy models for urban buildings and describes the basic workflow of physics-based, bottom-up models and their applications in simulating urban-scale building energy use. Because there are significant differences across models with varied potential for application, strengths and weaknesses of the reviewed models are also presented. This is followed by a discussion of challenging issues associated with model preparation and calibration.

Energy Contribution of OFMSW (Organic Fraction of Municipal Solid Waste to Energy-Environmental Sustainability in Urban Areas at Small Scale

Directory of Open Access Journals (Sweden)

Umberto Di Matteo

2017-02-01

Full Text Available Urban waste management is one of the most challenging issues in energy planning of medium and large cities. In addition to the traditional landfill method, many studies are investigating energy harvesting from waste, not as a panacea but as a foreseeable solution. Thermo-chemical conversion to biogas, or even bio-methane under certain conditions, could be an option to address this challenge. This study focuses on municipal solid waste conversion to biogas as a local energy supply for the cities. Three urban models and their subdivision into urban areas were identified along with a typical Organic Fraction of Municipal Solid Waste (OFMSW matrix for each urban area. Then, an energy analysis was carried out to provide an optimization map for an informed choice by urban policy-makers and stakeholders. The results highlighted how the urban context and its use could affect the opportunity to produce energy from waste or to convert it in fuel. So, in this case, sustainability means waste turning from a problem to a renewable resource.

Occurrence of polycyclic aromatic hydrocarbons in surface sediments of a highly urbanized river system with special reference to energy consumption patterns

International Nuclear Information System (INIS)

Zhang Kai; Wang Jizhong; Liang Bo; Zeng, Eddy Y.

2011-01-01

Sediment samples collected from downstream of the Dongjiang River, a highly urbanized river network within the Pearl River Delta of South China, were analyzed for 28 polycyclic aromatic hydrocarbons (PAHs). Total concentrations of 28 PAHs, 16 priority PAHs designated by the United States Environmental Protection Agency (USEPA) and the seven carcinogenic PAHs classified by the USEPA ranged from 480 to 4600, 100 to 3400 and 10 to 1700 ng/g dry weight, respectively. Principal component analysis-based stepwise multivariate linear regression showed that sediment PAHs were predominantly derived from coal combustion, refined fossil fuel combustion and oil spills, accounting for 37%, 32% and 23%, respectively, of the total loading. The levels of sediment PAHs remained steady from 2002 to 2008, during which fossil fuel consumption had doubled, probably reflecting efforts to control PAH emissions from fossil fuel combustion. Finally, use of natural gas and liquefied petroleum gas in automobiles should be encouraged to improve environmental quality. - Highlights: → PAHs in sediment showed similar input sources as those in air particles. → Combustion of fossil fuel is the predominant source for sediment PAHs. → Local efforts to control PAHs emissions from fossil fuel combustion were effective. → Promotion of natural gas and liquefied petroleum gas can reduce emissions of PAHs. - Occurrence of PAHs in surface sediments from a highly urbanized river system is assessed in relation to energy consumption patterns.

Energy Transition in the Nebular City: Connecting Transition Thinking, Metabolism Studies, and Urban Design

Directory of Open Access Journals (Sweden)

Griet Juwet

2018-03-01

Full Text Available Transforming urban infrastructures is an essential part of creating more sustainable urban regions. But rethinking these complex systems requires a better understanding of their spatial dimensions and their relation with urban morphology and spatial structure. This paper addresses that gap by examining different conceptualizations of technical infrastructure and space in science, technology and society studies (STS, transition thinking, urban metabolism studies, and urban political ecology, and draws connections with the spatial perspective of urban planning and design. It illustrates and tests these concepts through the case of energy transition in the Flemish region of Belgium. Transport and supply networks have played a crucial role in facilitating, structuring, and reproducing the region’s characteristic dispersed and energy-intensive urban landscape. Bringing different disciplinary perspectives together, the research broadens the conceptualization of the spatial dimension in transition thinking, and identifies useful concepts and design parameters for urban design to engage with the technical and socio-political complexity of transforming urban infrastructure. It reveals the energy transition as an inherently spatial project, and explores the spatially and socio-politically transformative potential of the transition towards a new energy system.

China's energy demand and its characteristics in the industrialization and urbanization process

International Nuclear Information System (INIS)

Jiang Zhujun; Lin Boqiang

2012-01-01

China is currently in the process of industrialization and urbanization, which is the key stage of transition from a low-income country to a middle-income country and requires large amount of energy. The process will not end until 2020, so China's primary energy demand will keep high growth in the mid-term. Although each country is unique considering its particular history and background, all countries are sharing some common rules in energy demand for economic development. Based on the comparison with developed countries, here, we report some rules in the process of industrialization and urbanization as follows: (1) urbanization always goes along with industrialization; (2) the higher economic growth is, the higher energy demand is; (3) economic globalization makes it possible to shorten the time of industrialization, but the shorter the transition phase is, the faster energy demand grows; (4) the change of energy intensity presents as an “inverted U” curve, but whose shape can be changed for different energy policy. The above rules are very important for the Chinese government in framing its energy policy. - Highlights: ► China's energy demand will maintain high growth in mid-term. ► Urbanization always goes along with industrialization. ► Higher economic growth needs more energy. ► The energy intensity presents as an “inverted U” curve.

Energy efficiency and urbanism: Guide for urbanism planning energetically efficiency; Eficiencia energetica y urbanismo: Guia del planeamiento urbanistico energeticamente eficiente

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The present book summarizes the urbanism in the context of energy efficiency. the book has 4 chapters and 3 annexes: The energy in the context of substantiality, the soil planning, recommendations for the urbanism planning with substantiality criteria and small description URBE project.

Energy transition or incremental change? Green policy agendas and the adaptability of the urban energy regime in Los Angeles

International Nuclear Information System (INIS)

Monstadt, Jochen; Wolff, Annika

2015-01-01

Drawing on recent research in urban policy studies and social studies of technology, this paper examines the capability of urban energy regimes in adapting to environmental policy pressures. Focusing on the case of the City of Los Angeles, we critically analyze the transformative capacity of the city's recent energy and climate policies and the innovation patterns of its urban infrastructure regime. This case study suggests that despite considerable success in switching from coal to renewable energies, the patterns of sociotechnical change in Los Angeles still tend to supplement and sustain the existing regime. Sociotechnical change in Los Angeles tends to unfold incrementally through adjustments within the established patterns of the existing regime. - Highlights: • Theory-guided case study on the transition of the urban energy regime in Los Angeles. • Evaluation of the transformative capacity of environmental policies. • Assessment of the adaptability and innovation patterns of urban infrastructure regimes. • The policy changes have sustained the existing regime and unfold incrementally

Heavy metal contamination in surface runoff sediments of the urban area of Vilnius, Lithuania

Directory of Open Access Journals (Sweden)

Gytautas Ignatavičius

2017-02-01

Full Text Available Surface runoff from urbanized territories carries a wide range of pollutants. Sediments in untreated runoff from direct discharge stormwater systems significantly contribute to urban waterway pollution. In this study, heavy metal (Pb, Zn, Cu, Cr, Ba, As and Fe contamination in surface runoff sediments of the urban area of the city of Vilnius was investigated. The surface runoff sediment samples were collected from seven dischargers with the highest volume rate of water flow and concentrations of suspended solids. The geospatial analysis of the distribution of heavy metals shows that there are several active pollution sources supplying the dischargers with contaminated sediments. Most of these areas are located in the central part of the city and in old town with intense traffic. Principal components analysis and t-test results clearly depicted the significantly different chemical compositions of winter and autumn surface sediment samples. The sampling approach and assessment of results provide a useful tool to examine the contamination that is generated in urban areas, distinguish pollution sources and give a better understanding of the importance of permeable surfaces and green areas.

Direct Energy Consumption Associated Emissions by Rural-to-Urban Migrants in Beijing.

Science.gov (United States)

Ru, Muye; Tao, Shu; Smith, Kirk; Shen, Guofeng; Shen, Huizhong; Huang, Ye; Chen, Han; Chen, Yilin; Chen, Xi; Liu, Junfeng; Li, Bengang; Wang, Xilong; He, Canfei

2015-11-17

Hundreds of millions of rural residents have migrated to cities in China in recent years. Different lifestyles and living conditions lead to substantial changes in their household energy. Here, we present the result of a survey on direct household energy use of low-skilled rural-to-urban migrants in Beijing. The migrants moved up the energy ladder immediately after arriving in the city by replacing biomass fuels with coal, electricity, and liquefied petroleum gas. After the original shift, pattern of household energy use by the migrants has not changed much over decades, likely due to the long-existing household registration system (Hukou). As a result, the mix of energy types used by the rural-to-urban migrants were different from those by long-term urban residents, although total quantities were similar. Shifting from biomass fuels to coal, the migrants emitted 2.4 times more non-neutral CO2 than rural residents and 14% more than urban residents. The migration also resulted in significant increase in emissions of SO2 and mercury but dramatic decreases in some incomplete combustion products including particulate matter. All these changes have significant implication on air quality, health, and climate considering the scale of urbanization in China.

Urban energy planning in Tartu

DEFF Research Database (Denmark)

Große, Juliane; Groth, Niels Boje; Fertner, Christian

The Estonian planning system allots the main responsibilities for planning activities to the local level, whereas the regional level (county) is rather weak. That implies a gap of cooperation on the regional level, leading to dispersed urban development in suburban municipalities and ongoing urban...... sprawl in the vicinity of Tartu. This development appears contrary to the concept of “low-density urbanised space” as formulated in the National Spatial Plan “Estonia 2030+” (NSP) as the central spatial development concept for Estonia and also to a compact and intensive city development as formulated...... in the Master Plan of Tartu. Since Tartu has no relevant big industries, the main employers are the municipality and the university, energy related challenges occur from transport and residential (district) heating. The modal split shows big differences between journeys within Tartu and journeys between Tartu...

The Factors Influencing Transport Energy Consumption in Urban Areas: a Review

Directory of Open Access Journals (Sweden)

Rocco Papa

2014-05-01

Full Text Available Transport energy consumption accounts for about one third of total energy consumption in EU. Despite significant advances in transport technology and fuel formulation, transport energy consumption has increased in most EU countries over the last three decades. This increase in consumption occurred as a result of factors such as higher car ownership, a growth in automobile use and an increase in vehicle distances traveled. As travel and land-use are a function of one another, it is often hypothesized that changing urban structure can result in changes in energy consumption. Understanding how different land use characteristics may influence travel behaviour and the corresponding energy consumption is crucial for planners and policy makers in order to develop strategic actions to shrink the environmental footprint of the urban transportation sector. The aim of this article is to review the current literature on the connections between land use, travel behavior and energy consumption. In particular, this paper seeks to identify the determinants of transport energy consumption in urban areas by reviewing evidence from empirical studies. To this aim, nine characteristics of land use are presented and their effects on both travel behaviour and energy use are discussed Our review shown that, in contrast to the focus on the effect of the built environment on travel, only few researchers have empirically investigated the linkage between the built environment and transportation energy use. The research described in this paper has been developed within the PON04a2_E Smart Energy Master project. It represents part of a much broader research project aimed at the development of an integrated model of urban energy efficiency.

Dilemmas of energy efficient urban development in three Nordic cities

DEFF Research Database (Denmark)

Große, Juliane; Fertner, Christian; Groth, Niels Boje

Energy is high on the agenda of the European Union and in current urban development. In this study we focus on the role of urban planning in energy efficiency in 3 Northern European cities - Turku (FI), Eskilstuna (SE) and Tartu (EE). The case studies were developed in close collaboration between...... the authors and representatives of the cities. The research was carried out by field trips, interviews and analysis of local reports and planning documents. This work was done in the framework of the EU-FP7 project PLEEC (Planning for energy efficient cities), GA no. 314704, www.pleecproject.eu...

Global analysis of urban surface water supply vulnerability

International Nuclear Information System (INIS)

Padowski, Julie C; Gorelick, Steven M

2014-01-01

This study presents a global analysis of urban water supply vulnerability in 71 surface-water supplied cities, with populations exceeding 750 000 and lacking source water diversity. Vulnerability represents the failure of an urban supply-basin to simultaneously meet demands from human, environmental and agricultural users. We assess a baseline (2010) condition and a future scenario (2040) that considers increased demand from urban population growth and projected agricultural demand. We do not account for climate change, which can potentially exacerbate or reduce urban supply vulnerability. In 2010, 35% of large cities are vulnerable as they compete with agricultural users. By 2040, without additional measures 45% of cities are vulnerable due to increased agricultural and urban demands. Of the vulnerable cities in 2040, the majority are river-supplied with mean flows so low (1200 liters per person per day, l/p/d) that the cities experience ‘chronic water scarcity’ (1370 l/p/d). Reservoirs supply the majority of cities facing individual future threats, revealing that constructed storage potentially provides tenuous water security. In 2040, of the 32 vulnerable cities, 14 would reduce their vulnerability via reallocating water by reducing environmental flows, and 16 would similarly benefit by transferring water from irrigated agriculture. Approximately half remain vulnerable under either potential remedy. (letter)

Within-Class and Neighborhood Effects on the Relationship between Composite Urban Classes and Surface Temperature

Directory of Open Access Journals (Sweden)

Peleg Kremer

2018-02-01

Full Text Available Understanding the relationship between urban structure and ecological function—or environmental performance—is important for the planning of sustainable cities, and requires examination of how components in urban systems are organized. In this paper, we develop a Structure of Urban Landscape (STURLA classification, identifying common compositions of urban components using Berlin, Germany as a case study. We compute the surface temperature corresponding to each classification grid cell, and perform within-cell and neighborhood analysis for the most common composite classes in Berlin. We found that with-class composition and neighborhood composition as well as the interaction between them drive surface temperature. Our findings suggest that the spatial organization of urban components is important in determining the surface temperature and that specific combinations, such as low-rise buildings surrounded by neighborhood trees, or mid-rise buildings surrounded by high-rise buildings, compound to create a cooling effect. These findings are important for developing an understanding of how urban planning can harness structure-function relationships and improve urban sustainability.

Sustainable urban rail systems: Strategies and technologies for optimal management of regenerative braking energy

International Nuclear Information System (INIS)

González-Gil, Arturo; Palacin, Roberto; Batty, Paul

2013-01-01

Highlights: • Review of principal regenerative braking strategies and technologies for urban rail. • Different energy storage technologies are assessed for use in urban rail. • Optimising timetables is a preferential measure to improve energy efficiency. • Energy storage systems improve efficiency and reliability of urban rail systems. • Reversible substations allow for a complete recovery of braking energy. - Abstract: In a society characterised by increasing rates of urbanisation and growing concerns about environmental issues like climate change, urban rail transport plays a key role in contributing to sustainable development. However, in order to retain its inherent advantages in terms of energy consumption per transport capacity and to address the rising costs of energy, important energy efficiency measures have to be implemented. Given that numerous and frequent stops are a significant characteristic of urban rail, recuperation of braking energy offers a great potential to reduce energy consumption in urban rail systems. This paper presents a comprehensive overview of the currently available strategies and technologies for recovery and management of braking energy in urban rail, covering timetable optimisation, on-board and wayside Energy Storage Systems (ESSs) and reversible substations. For each measure, an assessment of their main advantages and disadvantages is provided alongside a list of the most relevant scientific studies and demonstration projects. This study concludes that optimising timetables is a preferential measure to increase the benefits of regenerative braking in any urban rail system. Likewise, it has been observed that ESSs are a viable solution to reuse regenerative energy with voltage stabilisation and energy saving purposes. Electrochemical Double Layer Capacitors has been identified as the most suitable technology for ESSs in general, although high specific power batteries such as Li-ion may become a practical option for on

Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs.

Science.gov (United States)

Edmondson, J L; Stott, I; Davies, Z G; Gaston, K J; Leake, J R

2016-09-19

Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-sized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health.

Urban Thermodynamic Island in a Coastal City Analysed from an Optimized Surface Network

Science.gov (United States)

Pigeon, Grégoire; Lemonsu, Aude; Long, Nathalie; Barrié, Joël; Masson, Valéry; Durand, Pierre

2006-08-01

Within the framework of ESCOMPTE, a French experiment performed in June and July 2001 in the south-east of France to study the photo-oxidant pollution at the regional scale, the urban boundary layer (UBL) program focused on the study of the urban atmosphere over the coastal city of Marseille. A methodology developed to optimize a network of 20 stations measuring air temperature and moisture over the city is presented. It is based on the analysis of a numerical simulation, performed with the non-hydrostatic, mesoscale Meso-NH model, run with four nested-grids down to a horizontal resolution of 250 m over the city and including a specific parametrization for the urban surface energy balance. A three-day period was modelled and evaluated against data collected during the preparatory phase for the project in summer 2000. The simulated thermodynamic surface fields were analysed using an empirical orthogonal function (EOF) decomposition in order to determine the optimal network configuration designed to capture the dominant characteristics of the fields. It is the first attempt of application of this kind of methodology to the field of urban meteorology. The network, of 20 temperature and moisture sensors, was implemented during the UBL-ESCOMPTE experiment and continuously recorded data from 12 June to 14 July 2001. The measurements were analysed in order to assess the urban thermodynamic island spatio-temporal structure, also using EOF decomposition. During nighttime, the influence of urbanization on temperature is clear the field is characterized by concentric thermo-pleths around the old core of the city, which is the warmest area of the domain. The moisture field is more influenced by proximity to the sea and airflow patterns. During the day, the sea breeze often moves from west or south-west and consequently the spatial pattern for both parameters is characterized by a gradient perpendicular to the shoreline. Finally, in order to assess the methodology adopted, the

Sea-town interactions over Marseille: 3D urban boundary layer and thermodynamic fields near the surface

Science.gov (United States)

Lemonsu, A.; Pigeon, G.; Masson, V.; Moppert, C.

2006-02-01

3D numerical simulations with the Meso-NH atmospheric model including the Town Energy Balance urban parameterization, are conducted over the south-east of France and the one million inhabitants city of Marseille in the frameworks of the ESCOMPTE-UBL program. The geographic situation of the area is relatively complex, because of the proximity of the Mediterranean Sea and the presence of numerous massifs, inducing complex meteorological flows. The present work is focused on six days of the campaign, characterized by the development of strong summer sea-breeze circulations. A complete evaluation of the model is initially realized at both regional- and city-scales, by using the large available database. The regional evaluation shows a good behavior of the model, during the six days of simulation, either for the parameters near the surface or for the vertical profiles describing the structure of the atmosphere. The urban-scale evaluation indicates that the fine structure of the horizontal fields of air temperature above the city is correctly simulated by the model. A specific attention is then pointed to the 250-m horizontal resolution outputs, focused on the Marseille area, for two days of the campaign. From the study of the vertical structure of the Urban Boundary Layer and the thermodynamic fields near the surface, one underscores the important differences due to the regional and local flows, and the complex interactions that occur between the urban effects and the effects of sea breezes.

Energy in the urban environment. Proceedings of the 22. annual Illinois energy conference

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

The conference addressed the energy and environmental challenges facing large metropolitan areas. The topics included a comparison of the environmental status of cities twenty years ago with the challenges facing today`s large cities, sustainable economic development, improving the energy and environmental infrastructure, and the changing urban transportation sector. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

RAINWATER MANAGEMENT AIMING TO IMPROVE THE QUALITY OF URBAN SURFACE RUNOFF

Directory of Open Access Journals (Sweden)

I. HAIDU

2015-10-01

Full Text Available Rainwater Management Aiming to Improve the Quality of Urban Surface Runoff. Currently many urban areas experience the quality degradation of rooftop runoff and accumulated rainwater. The present study aims to estimate the volume of water draining from rooftops within an area of 0.68 km² in the municipality of Cluj-Napoca. The volume of water flowing from rooftops presents a beneficial alternative not only for collecting rainwater for later use, but also for reducing the volume of water and for improving surface runoff quality in urban areas. The procedure was based on the Michel Simplified SCS-CN model, a derived variant of the most popular hydrological model, the Soil Conservation Service Curve Number (SCS-CN. The results of the applied method reveal that the highest rooftop runoff water values correspond to the summer months, these being based on daily rainfall data. Estimating the volume of water draining from rooftops for future harvesting is an important step in the sustainable management of rainwater in urban areas and in improving water quality.

Wastewater treatment and reuse in urban agriculture: exploring the food, energy, water, and health nexus in Hyderabad, India

Science.gov (United States)

Miller-Robbie, Leslie; Ramaswami, Anu; Amerasinghe, Priyanie

2017-07-01

Nutrients and water found in domestic treated wastewater are valuable and can be reutilized in urban agriculture as a potential strategy to provide communities with access to fresh produce. In this paper, this proposition is examined by conducting a field study in the rapidly developing city of Hyderabad, India. Urban agriculture trade-offs in water use, energy use and GHG emissions, nutrient uptake, and crop pathogen quality are evaluated, and irrigation waters of varying qualities (treated wastewater, versus untreated water and groundwater) are compared. The results are counter-intuitive, and illustrate potential synergies and key constraints relating to the food-energy-water-health (FEW-health) nexus in developing cities. First, when the impact of GHG emissions from untreated wastewater diluted in surface streams is compared with the life cycle assessment of wastewater treatment with reuse in agriculture, the treatment-plus-reuse case yields a 33% reduction in life cycle system-wide GHG emissions. Second, despite water cycling benefits in urban agriculture, only contamination and farmer behavior and harvesting practices. The study uncovers key physical, environmental, and behavioral factors that constrain benefits achievable at the FEW-health nexus in urban areas.

PALM-USM v1.0: A New Urban Surface Model Integrated into the PALM Large-eddy Simulation Model

Czech Academy of Sciences Publication Activity Database

Resler, Jaroslav; Krč, Pavel; Belda, Michal; Juruš, Pavel; Benešová, N.; Lopata, J.; Vlček, O.; Damašková, D.; Eben, Kryštof; Derbek, P.; Maronga, P.; Kanani-Sühring, F.

2017-01-01

Roč. 10, č. 10 (2017), s. 3635-3659 ISSN 1991-959X Grant - others:UrbanAdapt(XE) EHP-CZ02-OV-1-036-2015; Ga MŠk(CZ) LM2015070 Program:CZ02 Biodiverzita a ekosystémové služby / Monitorování a integrované plánování a kontrola v životním prostředí/ Adaptace na změnu klimatu Institutional support: RVO:67985807 Keywords : urban modelling * PALM * LES * surface energy balance * radiative transfer * model evaluation * infrared camera Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences Impact factor: 3.458, year: 2016

Household energy preferences for cooking in urban Ouagadougou, Burkina Faso

International Nuclear Information System (INIS)

Ouedraogo, Boukary

2006-01-01

An extensive survey on household expenditures in Ouagadougou, the capital of Burkina Faso, was used to analyze the factors determining urban household energy choices using a multinomial logit model. Wood-energy remains the preferred fuel of most urban households in the country; though rational, the choice is not sustainable as it portends a threat to the savanna woodlands and the economy. Many important policies have been adopted by public authorities to minimize household wood-energy consumption and to substitute it by alternative fuel. Despite the magnitude of all these policies, the depletion rate of the forest resource is increasing. A kind of inertia is thus observed for household preferences for cooking fuel. This model analyzes the sociological and economic variables of household energy preferences for cooking in Ouagadougou. The analyses show that the inertia of household cooking energy preferences are due to poverty factors such as low income, poor household access to electricity for primary and secondary energy, low house standard, household size, high frequency of cooking certain meals using woodfuel as cooking energy. The descriptive analyses show that the domestic demand for wood-energy is strongly related to household income. The firewood utilization rate decreases with increasing household income. In other words, this fuel appears as a 'transition good' for these households which aim for other sources of energy for cooking that are more adapted for urban consumption. This implies that a price subsidy policy for liquid petroleum gas (LPG) and its cook stoves could significantly decrease the utilization rate of wood-energy

Contamination by urban superficial runoff: accumulated heavy metals on a road surface

Directory of Open Access Journals (Sweden)

Carlos Alfonso Zafra Mejía

2007-01-01

Full Text Available Studying the behaviour of accumulated contamination on urban surfaces is important in designing control methods minimising the impacts of surface runoff on the environment. This paper presents data regarding the sediment collected on the surface of an urban road in the city of Torrelavega in northern Spain during a period of 65 days during which 132 samples were collected. Two types of sediment collection samples were obtained: vacuumed dry samples (free load and those swept up following vacuuming (fixed load. The results showed that heavy metal concentration in the collected sediment (Pb, Zn, Cu and Cd was inversely proportional to particle diameter. High heavy metal concentrations were found in the smaller fraction (63 pm. Regression equations were calculated for heavy metal concentration regarding particle diameter. Large heavy metal loads were found in the larger fraction (125 pm. The results provide information for analysing runoff water quality in urban areas and designing treatment strategies.

Biomimetic Urban Design: Ecosystem Service Provision of Water and Energy

Directory of Open Access Journals (Sweden)

Maibritt Pedersen Zari

2017-03-01

Full Text Available This paper presents an ecosystem biomimicry methodology for urban design called ecosystem service analysis. Ecosystem services analysis can provide quantifiable goals for urban ecological regeneration that are determined by site specific ecology and climate of an urban area. This is important given the large negative environmental impact that most cities currently have on ecosystems. If cities can provide some of their own ecosystem services, pressure may be decreased on the surrounding ecosystems. This is crucial because healthier ecosystems enable humans to better adapt to the impacts that climate change is currently having on urban built environments and will continue to have in the future. A case study analyzing two ecosystem services (provision of energy and provision of water for an existing urban environment (Wellington, New Zealand is presented to demonstrate how the ecosystem services analysis concept can be applied to an existing urban context. The provision of energy in Wellington was found to be an example of an ecosystem service where humans could surpass the performance of pre-development ecosystem conditions. When analyzing the provision of water it was found that although total rainfall in the urban area is almost 200% higher than the water used in the city, if rainwater harvested from existing rooftops were to meet just the demands of domestic users, water use would need to be reduced by 20%. The paper concludes that although achieving ecological performance goals derived from ecosystem services analysis in urban areas is likely to be difficult, determining site and climate specific goals enable urban design professionals to know what a specific city should be aiming for if it is to move towards better sustainability outcomes.

Assessing the Impact of Urbanization Using Remote Sensing On A Global Scale, Past Present And Future Directions

Science.gov (United States)

Luvall, J. C.

2016-12-01

It is estimated that by the year 2025, 80% of the world's population will live in cities. This conversion of the natural landscape vegetation into man-made urban structures such as roads and buildings drastically alter the regional surface energy budgets, hydrology, precipitation patterns, and meteorology. The urban heat island (UHI) results from the energy that is absorbed by man-made materials during the day and is released at night resulting in the heating of the air within the urban area. The magnitude of the air temperature differences between the urban and surrounding countryside can be 2-8 o C. The UHI was one of the earliest recognized and measured phenomena of urbanization which was reported as early as 1833 for London (Howard, 1833) and 1862 for Paris. Research studies from many cities have documented that these effects range from decreases in air quality, increased energy consumption, and alteration of regional climate to direct effects on human health. To understand why the UHI phenomena exists, it is useful to define the surface in terms of the surface energy budget. Surface temperature and albedo are major components of the surface energy budget. Knowledge of it is important in any attempt to describe the radiative and mass fluxes that occur at the surface. Use of energy terms in modeling surface energy budgets allows the direct comparison of various land surfaces encountered in an urban landscape, from vegetated (forest and herbaceous) to non-vegetated (bare soil, roads, and buildings). These terms are also easily measured using remote sensing from aircraft or satellite platforms allowing one to examine the spatial variability of the urban surface. Planned NASA space borne missions include an ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) a five channel, 37x 50m resolution thermal instrument on space station and a Hyperspectral Infrared Imager (HyspIRI), a 30m resolution hyperspectral and 60m resolution multispectral

Characterizing heavy metal build-up on urban road surfaces: Implication for stormwater reuse

International Nuclear Information System (INIS)

Liu, An; Liu, Liang; Li, Dunzhu; Guan, Yuntao

2015-01-01

Stormwater reuse is increasingly popular in the worldwide. In terms of urban road stormwater, it commonly contains toxic pollutants such as heavy metals, which could undermine the reuse safety. The research study investigated heavy metal build-up characteristics on urban roads in a typical megacity of South China. The research outcomes show the high variability in heavy metal build-up loads among different urban road sites. The degree of traffic congestion and road surface roughness was found to exert a more significant influence on heavy metal build-up rather than traffic volume. Due to relatively higher heavy metal loads, stormwater from roads with more congested traffic conditions or rougher surfaces might be suitable for low-water-quality required activities while the stormwater from by-pass road sections could be appropriate for relatively high-water-quality required purposes since the stormwater could be relatively less polluted. Based on the research outcomes, a decision-making process for heavy metals based urban road stormwater reuse was proposed. The new finding highlights the importance to undertaking a “fit-for-purpose” road stormwater reuse strategy. Additionally, the research results can also contribute to enhancing stormwater reuse safety. - Highlights: • Heavy metal (HM) build-up varies with traffic and road surface conditions. • Traffic congestion and surface roughness exert a higher impact on HM build-up. • A “fit-for-purpose” strategy could suit urban road stormwater reuse

Characterizing heavy metal build-up on urban road surfaces: Implication for stormwater reuse

Energy Technology Data Exchange (ETDEWEB)

Liu, An [Research Centre of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, 518055 Shenzhen (China); Cooperative Research and Education Centre for Environmental Technology, Kyoto University–Tsinghua University, 518055 Shenzhen (China); Liu, Liang; Li, Dunzhu [Research Centre of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, 518055 Shenzhen (China); Guan, Yuntao, E-mail: guanyt@tsinghua.edu.cn [Research Centre of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, 518055 Shenzhen (China); School of Environment, Tsinghua University, Beijing 100084 (China)

2015-05-15

Stormwater reuse is increasingly popular in the worldwide. In terms of urban road stormwater, it commonly contains toxic pollutants such as heavy metals, which could undermine the reuse safety. The research study investigated heavy metal build-up characteristics on urban roads in a typical megacity of South China. The research outcomes show the high variability in heavy metal build-up loads among different urban road sites. The degree of traffic congestion and road surface roughness was found to exert a more significant influence on heavy metal build-up rather than traffic volume. Due to relatively higher heavy metal loads, stormwater from roads with more congested traffic conditions or rougher surfaces might be suitable for low-water-quality required activities while the stormwater from by-pass road sections could be appropriate for relatively high-water-quality required purposes since the stormwater could be relatively less polluted. Based on the research outcomes, a decision-making process for heavy metals based urban road stormwater reuse was proposed. The new finding highlights the importance to undertaking a “fit-for-purpose” road stormwater reuse strategy. Additionally, the research results can also contribute to enhancing stormwater reuse safety. - Highlights: • Heavy metal (HM) build-up varies with traffic and road surface conditions. • Traffic congestion and surface roughness exert a higher impact on HM build-up. • A “fit-for-purpose” strategy could suit urban road stormwater reuse.

Building Analysis for Urban Energy Planning Using Key Indicators on Virtual 3d City Models - the Energy Atlas of Berlin

Science.gov (United States)

Krüger, A.; Kolbe, T. H.

2012-07-01

In the context of increasing greenhouse gas emission and global demographic change with the simultaneous trend to urbanization, it is a big challenge for cities around the world to perform modifications in energy supply chain and building characteristics resulting in reduced energy consumption and carbon dioxide mitigation. Sound knowledge of energy resource demand and supply including its spatial distribution within urban areas is of great importance for planning strategies addressing greater energy efficiency. The understanding of the city as a complex energy system affects several areas of the urban living, e.g. energy supply, urban texture, human lifestyle, and climate protection. With the growing availability of 3D city models around the world based on the standard language and format CityGML, energy system modelling, analysis and simulation can be incorporated into these models. Both domains will profit from that interaction by bringing together official and accurate building models including building geometries, semantics and locations forming a realistic image of the urban structure with systemic energy simulation models. A holistic view on the impacts of energy planning scenarios can be modelled and analyzed including side effects on urban texture and human lifestyle. This paper focuses on the identification, classification, and integration of energy-related key indicators of buildings and neighbourhoods within 3D building models. Consequent application of 3D city models conforming to CityGML serves the purpose of deriving indicators for this topic. These will be set into the context of urban energy planning within the Energy Atlas Berlin. The generation of indicator objects covering the indicator values and related processing information will be presented on the sample scenario estimation of heating energy consumption in buildings and neighbourhoods. In their entirety the key indicators will form an adequate image of the local energy situation for

Sustainable urban regeneration based on energy balance

NARCIS (Netherlands)

Van Timmeren, A.; Zwetsloot, J.; Brezet, H.; Silvester, S.

2012-01-01

In this paper, results are reported of a technology assessment of the use and integration of decentralized energy systems and storage devices in an urban renewal area. First the general context of a different approach based on 'rethinking' and the incorporation of ongoing integration of coming

Energy And Environment in Urban Regeneration. Studies for a Method of Analysis of Urban Periphery

Directory of Open Access Journals (Sweden)

Paolo De Pascali

2014-05-01

Full Text Available Despite planning of urban regeneration has been theorized from several decades, today activating concrete programs encounters major difficulties. Moreover, the structural nature of economic crisis and the operators tendency to maintaining obsolete models of urban transformation certainly do not help to overcome the stalemate.The article argues, however, that this framework appears to evolve under the influence of some external factors that bring to the fore the importance of the energy - environmental components in the renewal of the existing city.This address, focused on the concept of urban environment, seems to identify new principles of economic environmental sustainability of the city that converge towards social models of smart community and urban models of smart city.The article then describes the research in progress regarding an operative method to define explicit and replicable bases of the urban environment concept to be considered in plans of urban renewal. Main fields of observation and measurement are “urban comfort” and “anthropogenic load (pollution”. An experimental application of the analysis is developed on the eastern area of Rome. Finally, the paper offers specific lines for the research development.

Reassessment of urbanization effect on surface air temperature trends at an urban station of North China

Science.gov (United States)

Bian, Tao; Ren, Guoyu

2017-11-01

Based on a homogenized data set of monthly mean temperature, minimum temperature, and maximum temperature at Shijiazhuang City Meteorological Station (Shijiazhuang station) and four rural meteorological stations selected applying a more sophisticated methodology, we reanalyzed the urbanization effects on annual, seasonal, and monthly mean surface air temperature (SAT) trends for updated time period 1960-2012 at the typical urban station in North China. The results showed that (1) urbanization effects on the long-term trends of annual mean SAT, minimum SAT, and diurnal temperature range (DTR) in the last 53 years reached 0.25, 0.47, and - 0.50 °C/decade, respectively, all statistically significant at the 0.001 confidence level, with the contributions from urbanization effects to the overall long-term trends reaching 67.8, 78.6, and 100%, respectively; (2) the urbanization effects on the trends of seasonal mean SAT, minimum SAT, and DTR were also large and statistically highly significant. Except for November and December, the urbanization effects on monthly mean SAT, minimum SAT, and DTR were also all statistically significant at the 0.05 confidence level; and (3) the annual, seasonal, and monthly mean maximum SAT series at the urban station registered a generally weaker and non-significant urbanization effect. The updated analysis evidenced that our previous work for this same urban station had underestimated the urbanization effect and its contribution to the overall changes in the SAT series. Many similar urban stations were being included in the current national and regional SAT data sets, and the results of this paper further indicated the importance and urgency for paying more attention to the urbanization bias in the monitoring and detection of global and regional SAT change based on the data sets.

Nested 1D-2D approach for urban surface flood modeling

Science.gov (United States)

Murla, Damian; Willems, Patrick

2015-04-01

Floods in urban areas as a consequence of sewer capacity exceedance receive increased attention because of trends in urbanization (increased population density and impermeability of the surface) and climate change. Despite the strong recent developments in numerical modeling of water systems, urban surface flood modeling is still a major challenge. Whereas very advanced and accurate flood modeling systems are in place and operation by many river authorities in support of flood management along rivers, this is not yet the case in urban water management. Reasons include the small scale of the urban inundation processes, the need to have very high resolution topographical information available, and the huge computational demands. Urban drainage related inundation modeling requires a 1D full hydrodynamic model of the sewer network to be coupled with a 2D surface flood model. To reduce the computational times, 0D (flood cones), 1D/quasi-2D surface flood modeling approaches have been developed and applied in some case studies. In this research, a nested 1D/2D hydraulic model has been developed for an urban catchment at the city of Gent (Belgium), linking the underground sewer (minor system) with the overland surface (major system). For the overland surface flood modelling, comparison was made of 0D, 1D/quasi-2D and full 2D approaches. The approaches are advanced by considering nested 1D-2D approaches, including infiltration in the green city areas, and allowing the effects of surface storm water storage to be simulated. An optimal nested combination of three different mesh resolutions was identified; based on a compromise between precision and simulation time for further real-time flood forecasting, warning and control applications. Main streets as mesh zones together with buildings as void regions constitute one of these mesh resolution (3.75m2 - 15m2); they have been included since they channel most of the flood water from the manholes and they improve the accuracy of

Energy requirements of consumption: Urban form, climatic and socio-economic factors, rebounds and their policy implications

International Nuclear Information System (INIS)

Wiedenhofer, Dominik; Lenzen, Manfred; Steinberger, Julia K.

2013-01-01

Household consumption requires energy to be used at all stages of the economic process, thereby directly and indirectly leading to environmental impacts across the entire production chain. The levels, structure and determinants of energy requirements of household consumption therefore constitute an important avenue of research. Incorporating the full upstream requirements into the analysis helps to avoid simplistic conclusions which would actually only imply shifts between consumption categories without taking the economy wide effects into account. This paper presents the investigation of the direct and indirect primary energy requirements of Australian households, contrasting urban, suburban and rural consumption patterns as well as inter- and intra-regional levels of inequality in energy requirements. Furthermore the spatial and socio-economic drivers of energy consumption for different categories of energy requirements are identified and quantified. Conclusions regarding the relationships between energy requirements, household characteristics, urban form and urbanization processes are drawn and the respective policy implications are explored. - Highlights: • We statistically analyze the energy requirements of consumption in Australia. • Contrasting urban/suburban/rural consumption patterns and spatial inequality. • Energy requirements are influenced by urban form, income and demographics. • Urban households require less direct energy, but their total consumption is higher. • Significant rebound effects can be expected when direct energy use is decreased

Urban sound energy reduction by means of sound barriers

Science.gov (United States)

Iordache, Vlad; Ionita, Mihai Vlad

2018-02-01

In urban environment, various heating ventilation and air conditioning appliances designed to maintain indoor comfort become urban acoustic pollution vectors due to the sound energy produced by these equipment. The acoustic barriers are the recommended method for the sound energy reduction in urban environment. The current sizing method of these acoustic barriers is too difficult and it is not practical for any 3D location of the noisy equipment and reception point. In this study we will develop based on the same method a new simplified tool for acoustic barriers sizing, maintaining the same precision characteristic to the classical method. Abacuses for acoustic barriers sizing are built that can be used for different 3D locations of the source and the reception points, for several frequencies and several acoustic barrier heights. The study case presented in the article represents a confirmation for the rapidity and ease of use of these abacuses in the design of the acoustic barriers.

Urban sound energy reduction by means of sound barriers

Directory of Open Access Journals (Sweden)

Iordache Vlad

2018-01-01

Full Text Available In urban environment, various heating ventilation and air conditioning appliances designed to maintain indoor comfort become urban acoustic pollution vectors due to the sound energy produced by these equipment. The acoustic barriers are the recommended method for the sound energy reduction in urban environment. The current sizing method of these acoustic barriers is too difficult and it is not practical for any 3D location of the noisy equipment and reception point. In this study we will develop based on the same method a new simplified tool for acoustic barriers sizing, maintaining the same precision characteristic to the classical method. Abacuses for acoustic barriers sizing are built that can be used for different 3D locations of the source and the reception points, for several frequencies and several acoustic barrier heights. The study case presented in the article represents a confirmation for the rapidity and ease of use of these abacuses in the design of the acoustic barriers.

A comparative analysis of urban energy governance in four European cities

International Nuclear Information System (INIS)

Morlet, Clémence; Keirstead, James

2013-01-01

Cities are at the forefront of efforts to combat climate change and in this paper, we examine the influence of urban energy governance on these policy goals. An innovative framework for quantifying the combined governance of cities and energy systems is presented before focusing on a detailed study of London, Paris, Berlin and Copenhagen. By applying an optimization model to assess the lowest cost technology pathways to achieve emission reduction targets, the links between the governance of urban energy systems and the cost of achieving carbon targets are shown. Additionally a novel metric of scenario similarity is introduced in order to evaluate the difficulty of hypothesized energy system transitions. The results indicate that these tools can be valuable in identifying similar cities for the sharing of best practice, for performing comparative evaluations of energy transitions, and for reinforcing the need to complement quantitative assessments with a more holistic appreciation of local context. - Highlights: • Novel framework for comparing urban energy systems and their governance is presented. • Applied to four European cities with focus on climate change issues. • Bhattacharyya's distance introduced as measure of energy system scenario similarity. • Results suggest Paris is closest to its 2020 climate goals, London furthest

The importance of surface finish to energy performance

Directory of Open Access Journals (Sweden)

Smith Geoff B.

2017-01-01

Full Text Available Power generation in solar energy systems, thermal control in buildings and mitigation of the Urban Heat Island problem, are all sensitive to directional response to incoming radiation. The radiation absorption and emission profile also plays a crucial role in each system's response and depends strongly on surface finish. This important sensitivity needs wider recognition in materials data sheets, system modeling, plus in materials and environmental engineering. The impact of surface roughness on thermal response of natural and man-made external environments is examined. Important examples will be given of the role of surface finish within each class. Total emittance links to the way surface finish influences directional emittance E(θ. Smooth surface thermal emittance on PV module covers, many solar absorbers, some roof paints, polished concrete, and glass windows can be up to 15% different from insulator results based on fully diffuse models of the same material. Widespread evidence indicates smooth metals and low-E solar absorber surfaces cool faster, and smooth insulators slower than previously thought. Matt paint is cooler than low sheen paint under the same solar heating impacts and normal concrete cooler than polished. Emittance for water is the prime environmental example of oblique impacts as it reflects strongly at oblique incidence, which leads to a significant drop in E(θ. Ripples or waves however raise water's average emittance. A surprise in this work was the high sensitivity of total E and its angular components to roughness in the depth range of 0.1–0.8 μm, which are well under ambient thermal IR wavelengths of 3–30 μm but common in metal finishing. Parallel energy flows such as evaporation and convective cooling vary if emittance varies. Thermal image analysis can provide insights into angular radiative effects.

City and Energy Infrastructures between Economic Processes and Urban Planning

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Giuseppe Mazzeo

2013-11-01

Full Text Available The paper deals with the issues related to the relationship between city, energy, economic factors and city planning. These issues are analyzed from a theoretical point of view and are placed in a logical path based on three assumptions. The first considers the city as an intelligent system constantly evolving. The second considers the city as a system where economic processes come out at their highest level affecting other aspects of social and urban structure. The third considers the planning as the weak link in the process of urban development, one of the most exposed to economic and social pressures.Energy production has experienced a great progress since steam and electricity were discovered. Each stage of this evolution has affected city and territory introducing significant physical signs, changing the ways of carrying out functions and creating new needs and new activities. The energy revolution, based on sustainable sources and on skillful management of the networks, will strongly affect the city and the way of organizing the activities, their location, dimension, and the shape of the spaces.The paper explores some of the issues related to the relationship between urban system and energy.The first section analyzes the meaning of the intelligent city as an entity that is constantly changing and constantly adapting. The second section analyzes the role of the energy systems in the evolution of the activities and of the city’s image. The last section investigates the role of the economic factors in the evolution of the shape and meaning of city, pointing out that the way towards smart and green urban systems will largely depend on their economic advantage. 

Surface runoff from urban areas. New aspects; Neue Aspekte in der Behandlung von Siedlungsabfluessen

Energy Technology Data Exchange (ETDEWEB)

Fuchs, Stephan [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Bereich Siedlungswasserwirtschaft und Wasserguetewirtschaft; Lambert, Benedikt [Bioplan Landeskulturgesellschaft, Sinsheim (Germany); Grotehusmann, Dieter [Ingenieurgesellschaft fuer Stadthydrologie, Hannover (Germany)

2010-12-15

The surface runoff from urban areas is one of the most important sources of pollutants emitted into surface waters. Suspended solids which act as a transport vehicle for many anthropogenic pollutants (e. g. heavy metals, PAH) are a key factor in this regard. The development of efficient measures of storm water runoff treatment thus requires a further differentiation of suspended solids in a fine (clay and silt) and coarse (sand and gravel) fraction. Both fractions show distinctly different characteristics in pollutant loading, transport and retention on urban surfaces and sewer systems. The primary aim of storm water runoff treatment is the reduction of the fine particles which are always highly loaded with anthropogenic pollutants. In contrast the coarse particles are almost unpolluted especially if they have a low organic share. The widespread sedimentation tanks with surface loadings between 10 and 2 m/h are very inefficient. A significant, save and lasting reduction of the emitted load of fine particles requires a considerable reduction of the surface loads. That can be achieved with the installation of lamellar settler or the utilization of the very large volumes of flood management tanks frequently present in urban areas. Filtration plants are highly efficient but there application in urban areas is limited due to their high space demands. (orig.)

Air pollution prevention through urban heat island mitigation: An update on the urban heat island pilot project

Energy Technology Data Exchange (ETDEWEB)

Gorsevski, V.; Taha, H.; Quattrochi, D.; Luvall, J.

1998-07-01

Urban heat islands increase the demand for cooling energy and accelerate the formation of smog. They are created when natural vegetation is replaced by heat-absorbing surfaces such as building roofs and walls, parking lots, and streets. Through the implementation of measures designed to mitigate the urban heat island, communities can decrease their demand for energy and effectively cool the metropolitan landscape. In addition to the economic benefits, using less energy leads to reductions in emission of CO{sub 2}--a greenhouse gas--as well as ozone (smog) precursors such as NOx and VOCs. Because ozone is created when NOx and VOCs photochemically combine with heat and solar radiation, actions taken to lower ambient air temperature can significantly reduce ozone concentrations in certain areas. Measures to reverse the urban heat island include afforestation and the widespread use of highly reflective surfaces. To demonstrate the potential benefits of implementing these measures, EPA has teamed up with NASA and LBNL to initiate a pilot project with three US cities. As part of the pilot, NASA will use remotely-sensed data to quantify surface temperature, albedo, the thermal response number and NDVI vegetation of each city. This information will be used by scientists at Lawrence Berkeley National Laboratory (LBNL) along with other data as inputs to model various scenarios that will help quantify the potential benefits of urban heat island mitigation measures in terms of reduced energy use and pollution. This paper will briefly describe this pilot project and provide an update on the progress to date.

The Urban Food-Water Nexus: Modeling Water Footprints of Urban Agriculture using CityCrop

Science.gov (United States)

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.

Shift in the microbial community composition of surface water and sediment along an urban river.

Science.gov (United States)

Wang, Lan; Zhang, Jing; Li, Huilin; Yang, Hong; Peng, Chao; Peng, Zhengsong; Lu, Lu

2018-06-15

Urban rivers represent a unique ecosystem in which pollution occurs regularly, leading to significantly altered of chemical and biological characteristics of the surface water and sediments. However, the impact of urbanization on the diversity and structure of the river microbial community has not been well documented. As a major tributary of the Yangtze River, the Jialing River flows through many cities. Here, a comprehensive analysis of the spatial microbial distribution in the surface water and sediments in the Nanchong section of Jialing River and its two urban branches was conducted using 16S rRNA gene-based Illumina MiSeq sequencing. The results revealed distinct differences in surface water bacterial composition along the river with a differential distribution of Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes and Acidobacteria (P urban water. PICRUSt metabolic inference analysis revealed a growing number of genes associated with xenobiotic metabolism and nitrogen metabolism in the urban water, indicating that urban discharges might act as the dominant selective force to alter the microbial communities. Redundancy analysis suggested that the microbial community structure was influenced by several environmental factors. TP (P urban river. These results highlight that river microbial communities exhibit spatial variation in urban areas due to the joint influence of chemical variables associated with sewage discharging and construction of hydropower stations. Copyright © 2018 Elsevier B.V. All rights reserved.

A Study of the Oklahoma City Urban Heat Island Effect Using a WRF/Single-Layer Urban Canopy Model, a Joint Urban 2003 Field Campaign, and MODIS Satellite Observations

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Hengyue Zhang

2017-09-01

Full Text Available The urban heat island effect (UHI for inner land regions was investigated using satellite data, ground observations, and simulations with an Single-Layer Urban Canopy Parameterization (SLUCP coupled into the regional Weather Research Forecasting model (WRF, http://wrf-model.org/index.php. Specifically, using the satellite-observed surface skin temperatures (Tskin, the intensity of the UHI was first compared for two inland cities (Xi’an City, China, and Oklahoma City (OKC, which have different city populations and building densities. The larger population density and larger building density in Xi’an lead to a stronger skin-level UHI by 2 °C. However, the ground observed 2 m surface air temperature (Tair observations showed an urban cooling island effect (UCI over the downtown region in OKC during the daytime of 19 July 2003, from a DOE field campaign (Joint Urban 2003. To understand this contrast between satellite-based Tskin and ground-based Tair, a sensitivity study using WRF/SLUCP was analyzed. The model reproduced a UCI in OKC. Furthermore, WRF/Noah/SLUCM simulations were also compared with the Joint Urban 2003 ground observations, including wind speeds, wind directions, and energy fluxes. Although the WRF/SLUCM model failed to simulate these variables accurately, it reproduced the diurnal variations of surface temperatures, wind speeds, wind directions, and energy fluxes reasonably well.

An experiment for urban energy autonomy in Seoul: The One ‘Less’ Nuclear Power Plant policy

International Nuclear Information System (INIS)

Lee, Taehwa; Lee, Taedong; Lee, Yujin

2014-01-01

This study examines an experiment in energy self-sufficiency in Seoul, Republic of Korea, through a particular energy policy called the One Less Nuclear Power Plant (OLNPP) policy. We define an urban energy experiment as a purposive intervention for energy transition from an energy system based on nuclear and fossil fuels to one based on renewable energy and energy demand management. We suggest three findings. First, we find that the themes of our theoretical framework policy backgrounds, governance and policy contents have played important roles for Seoul’s energy experiments aimed at urban energy autonomy. In particular, political leadership based on the mayor’s previous experiences contributed significantly to the formation and implementation of this policy. Second, the OLNPP policy adds a social or moral dimension to urban energy policies. The norm change from an environmental and economic focus to a focus on the combination of social, environmental, and economic considerations is a unique contribution of the OLNPP policy to urban experiments in energy transition. Third, we find that experiments through purposive interventions serve as a means for facilitating urban energy governance where the actors involved can communicate and enhance their new ideas and practices. - Highlights: • We analyze One Less Nuclear Power Plant policy, with background, governance and content framework. • The OLNPP policy aims to achieve energy self-sufficiency at a local scale. • An urban energy experiment is for energy transition to renewable energy and energy demand management. • A unique contribution of Seoul’s energy experiment is changing norms by adding a moral dimension

Sustainable Urban (re-Development with Building Integrated Energy, Water and Waste Systems

Directory of Open Access Journals (Sweden)

Tae-Goo Lee

2013-03-01

Full Text Available The construction and service of urban infrastructure systems and buildings involves immense resource consumption. Cities are responsible for the largest component of global energy, water, and food consumption as well as related sewage and organic waste production. Due to ongoing global urbanization, in which the largest sector of the global population lives in cities which are already built, global level strategies need to be developed that facilitate both the sustainable construction of new cities and the re-development of existing urban environments. A very promising approach in this regard is the decentralization and building integration of environmentally sound infrastructure systems for integrated resource management. This paper discusses such new and innovative building services engineering systems, which could contribute to increased energy efficiency, resource productivity, and urban resilience. Applied research and development projects in Germany, which are based on integrated system approaches for the integrated and environmentally sound management of energy, water and organic waste, are used as examples. The findings are especially promising and can be used to stimulate further research and development, including economical aspects which are crucial for sustainable urban (re-development.

Occurrence, distribution and risks of antibiotics in urban surface water in Beijing, China.

Science.gov (United States)

Li, Wenhui; Gao, Lihong; Shi, Yali; Liu, Jiemin; Cai, Yaqi

2015-09-01

The occurrence and distribution of 22 antibiotics, including eight fluoroquinolones, nine sulfonamides and five macrolides, were investigated in the urban surface waters in Beijing, China. A total of 360 surface water samples were collected from the main rivers and lakes in the urban area of Beijing monthly from July 2013 to June 2014 (except the frozen period). Laboratory analyses revealed that antibiotics were widely used and extensively distributed in the surface water of Beijing, and sulfonamides and fluoroquinolones were the predominant antibiotics with the average concentrations of 136 and 132 ng L(-1), respectively. A significant difference of antibiotic concentrations from different sampling sites was observed, and the southern and eastern regions of Beijing showed higher concentrations of antibiotics. Seasonal variation of the antibiotics in the urban surface water was also studied, and the highest level of antibiotics was found in November, which may be due to the low temperature and flow of the rivers during the period of cold weather. Risk assessment showed that several antibiotics might pose high ecological risks to aquatic organisms (algae and plants) in surface water, and more attention should be paid to the risk of antibiotics to the aquatic environment in Beijing.

Modeling Impact of Urbanization in US Cities Using Simple Biosphere Model SiB2

Science.gov (United States)

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

2016-01-01

We combine Landsat- and the Moderate Resolution Imaging Spectroradiometer (MODIS)-based products, as well as climate drivers from Phase 2 of the North American Land Data Assimilation System (NLDAS-2) in a Simple Biosphere land surface model (SiB2) to assess the impact of urbanization in continental USA (excluding Alaska and Hawaii). More than 300 cities and their surrounding suburban and rural areas are defined in this study to characterize the impact of urbanization on surface climate including surface energy, carbon budget, and water balance. These analyses reveal an uneven impact of urbanization across the continent that should inform upon policy options for improving urban growth including heat mitigation and energy use, carbon sequestration and flood prevention.

A research agenda for a people-centred approach to energy access in the urbanizing global south

Science.gov (United States)

Broto, Vanesa Castán; Stevens, Lucy; Ackom, Emmanuel; Tomei, Julia; Parikh, Priti; Bisaga, Iwona; To, Long Seng; Kirshner, Joshua; Mulugetta, Yacob

2017-10-01

Energy access is typically viewed as a problem for rural areas, but people living in urban settings also face energy challenges that have not received sufficient attention. A revised agenda in research and practice that puts the user and local planning complexities centre stage is needed to change the way we look at energy access in urban areas, to understand the implications of the concentration of vulnerable people in slums and to identify opportunities for planned management and innovation that can deliver urban energy transitions while leaving no one behind. Here, we propose a research agenda focused on three key issues: understanding the needs of urban energy users; enabling the use of context-specific, disaggregated data; and engaging with effective modes of energy and urban governance. This agenda requires interdisciplinary scholarship across the social and physical sciences to support local action and deliver large-scale, inclusive transformations.

Integrating ecosystem services in the assessment of urban energy trajectories – A study of the Stockholm Region

International Nuclear Information System (INIS)

Mörtberg, Ulla; Goldenberg, Romain; Kalantari, Zahra; Kordas, Olga; Deal, Brian; Balfors, Berit; Cvetkovic, Vladimir

2017-01-01

Urban development trajectories are changing towards compact, energy-efficient cities and renewable energy sources, and this will strongly affect ecosystem services (ES) that cities are dependent on but tend to disregard. Such ES can be provisioning, regulating and cultural ES, around which competition over land resources will increase with energy system shifts. Much of this can be foreseen to take place within urbanising regions that are simultaneously the living environment of a major part of the human population today. In order to inform critical urban policy decisions, tools for integrated assessment of urban energy and transport options and ecosystem services need to be developed. For this purpose, a case study of the Stockholm region was conducted, analysing three scenarios for the future urbanisation of the region, integrating a transport energy perspective and an ES perspective. The results showed that a dense but polycentric development pattern gives more opportunities for sustainable urban development, while the dense monocentric scenario has apparent drawbacks from an ES perspective. The methodology is compatible with a model integration platform for urban policy support and will thus enable integrated policy assessment of complex urban systems, with the goal of increasing their sustainability. - Highlights: • A diffuse urban pattern leads to low access to jobs and high energy consumption. • A dense monocentric urban pattern implies high energy efficiency and low access to ES. • A dense polycentric urban pattern allows for a combination of urban functions. • ES needs to be integrated into sustainability assessments of urban policy options.

The Effect of Increasing Surface Albedo on Urban Climate and Air Quality: A Detailed Study for Sacramento, Houston, and Chicago

Directory of Open Access Journals (Sweden)

Zahra Jandaghian

2018-03-01

Full Text Available Increasing surface reflectivity in urban areas can decrease ambient temperature, resulting in reducing photochemical reaction rates, reducing cooling energy demands and thus improving air quality and human health. The weather research and forecasting model with chemistry (WRF-Chem is coupled with the multi-layer of the urban canopy model (ML-UCM to investigate the effects of surface modification on urban climate in a two-way nested approach over North America focusing on Sacramento, Houston, and Chicago during the 2011 heat wave period. This approach decreases the uncertainties associated with scale separation and grid resolution and equip us with an integrated simulation setup to capture the full impacts of meteorological and photochemical reactions. WRF-ChemV3.6.1 simulated the diurnal variation of air temperature reasonably well, overpredicted wind speed and dew point temperature, underpredicted relative humidity, overpredicted ozone and nitrogen dioxide concentrations, and underpredicted fine particular matters (PM2.5. The performance of PM2.5 is a combination of overprediction of particulate sulfate and underprediction of particulate nitrate and organic carbon. Increasing the surface albedo of roofs, walls, and pavements from 0.2 to 0.65, 0.60, and 0.45, respectively, resulted in a decrease in air temperature by 2.3 °C in urban areas and 0.7 °C in suburban areas; a slight increase in wind speed; an increase in relative humidity (3% and dew point temperature (0.3 °C; a decrease of PM2.5 and O3 concentrations by 2.7 µg/m3 and 6.3 ppb in urban areas and 1.4 µg/m3 and 2.5 ppb in suburban areas, respectively; minimal changes in PM2.5 subspecies; and a decrease of nitrogen dioxide (1 ppb in urban areas.

Comprehensive Forecast of Urban Water-Energy Demand Based on a Neural Network Model

Directory of Open Access Journals (Sweden)

Ziyi Yin

2018-03-01

Full Text Available Water-energy nexus has been a popular topic of rese arch in recent years. The relationships between the demand for water resources and energy are intense and closely connected in urban areas. The primary, secondary, and tertiary industry gross domestic product (GDP, the total population, the urban population, annual precipitation, agricultural and industrial water consumption, tap water supply, the total discharge of industrial wastewater, the daily sewage treatment capacity, total and domestic electricity consumption, and the consumption of coal in industrial enterprises above the designed size were chosen as input indicators. A feedforward artificial neural network model (ANN based on a back-propagation algorithm with two hidden layers was constructed to combine urban water resources with energy demand. This model used historical data from 1991 to 2016 from Wuxi City, eastern China. Furthermore, a multiple linear regression model (MLR was introduced for comparison with the ANN. The results show the following: (a The mean relative error values of the forecast and historical urban water-energy demands are 1.58 % and 2.71%, respectively; (b The predicted water-energy demand value for 2020 is 4.843 billion cubic meters and 47.561 million tons of standard coal equivalent; (c The predicted water-energy demand value in the year 2030 is 5.887 billion cubic meters and 60.355 million tons of standard coal equivalent; (d Compared with the MLR, the ANN performed better in fitting training data, which achieved a more satisfactory accuracy and may provide a reference for urban water-energy supply planning decisions.

The Role of Vegetation in Mitigating Urban Land Surface Temperatures: A Case Study of Munich, Germany during the Warm Season

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Sadroddin Alavipanah

2015-04-01

Full Text Available The Urban Heat Island (UHI is the phenomenon of altered increased temperatures in urban areas compared to their rural surroundings. UHIs grow and intensify under extreme hot periods, such as during heat waves, which can affect human health and also increase the demand for energy for cooling. This study applies remote sensing and land use/land cover (LULC data to assess the cooling effect of varying urban vegetation cover, especially during extreme warm periods, in the city of Munich, Germany. To compute the relationship between Land Surface Temperature (LST and Land Use Land Cover (LULC, MODIS eight-day interval LST data for the months of June, July and August from 2002 to 2012 and the Corine Land Cover (CLC database were used. Due to similarities in the behavior of surface temperature of different CLCs, some classes were reclassified and combined to form two major, rather simplified, homogenized classes: one of built-up area and one of urban vegetation. The homogenized map was merged with the MODIS eight-day interval LST data to compute the relationship between them. The results revealed that (i the cooling effect accrued from urban vegetation tended to be non-linear; and (ii a remarkable and stronger cooling effect in terms of LST was identified in regions where the proportion of vegetation cover was between seventy and almost eighty percent per square kilometer. The results also demonstrated that LST within urban vegetation was affected by the temperature of the surrounding built-up and that during the well-known European 2003 heat wave, suburb areas were cooler from the core of the urbanized region. This study concluded that the optimum green space for obtaining the lowest temperature is a non-linear trend. This could support urban planning strategies to facilitate appropriate applications to mitigate heat-stress in urban area.

Impact of vegetation growth on urban surface temperature distribution

International Nuclear Information System (INIS)

Buyadi, S N A; Mohd, W M N W; Misni, A

2014-01-01

Earlier studies have indicated that, the temperature distribution in the urban area is significantly warmer than its surrounding suburban areas. The process of urbanization has created urban heat island (UHI). As a city expands, trees are cut down to accommodate commercial development, industrial areas, roads, and suburban growth. Trees or green areas normally play a vital role in mitigating the UHI effects especially in regulating high temperature in saturated urban areas. This study attempts to assess the effects of vegetation growth on land surface temperature (LST) distribution in urban areas. An area within the City of Shah Alam, Selangor has been selected as the study area. Land use/land cover and LST maps of two different dates are generated from Landsat 5 TM images of the year 1991 and 2009. Only five major land cover classes are considered in this study. Mono-window algorithm is used to generate the LST maps. Landsat 5 TM images are also used to generate the NDVI maps. Results from this study have shown that there are significant land use changes within the study area. Although the conversion of green areas into residential and commercial areas significantly increase the LST, matured trees will help to mitigate the effects of UHI

Study of the Relationships between the Spatial Extent of Surface Urban Heat Islands and Urban Characteristic Factors Based on Landsat ETM+ Data

Directory of Open Access Journals (Sweden)

Jinqu Zhang

2008-11-01

Full Text Available Ten cities with different population and urban sizes located in the Pearl River Delta, Guangdong Province, P.R. China were selected to study the relationships between the spatial extent of surface urban heat islands (SUHI and five urban characteristic factors such as urban size, development area, water proportion, mean NDVI (Normalized Vegetation Index and population density, etc. The spatial extent of SUHI was quantified by using the hot island area (HIA. All the cities are almost at the same latitude, showing similar climate and solar radiation, the influence of which could thus be eliminated during our computation and comparative study. The land surface temperatures (LST were retrieved from the data of Landsat 7 Enhanced Thematic Mapper Plus (ETM+ band 6 using a mono-window algorithm. A variance-segmenting method was proposed to compute HIA for each city from the retrieved LST. Factors like urban size, development area and water proportion were extracted directly from the classification images of the same ETM+ data and the population density factor is from the official census. Correlation and regression analyses were performed to study the relationships between the HIA and the related factors, and the results show that HIA is highly correlated to urban size (r=0.95, population density (r=0.97 and development area (r=0.83 in this area. It was also proved that a weak negative correlation existed between HIA and both mean NDVI and water proportion for each city. Linear functions between HIA and its related factors were established, respectively. The HIA can reflect the spatial extent and magnitude of the surface urban heat island effect, and can be used as reference in the urban planning.

Designing integrated energy and spatial development for sustainable urban areas in the Northern Netherlands

NARCIS (Netherlands)

Zheng, Ling

2006-01-01

This study aims to reduce CO2 emission in an efficient way in urban areas by reducing conventional energy use and implementing renewable energy. The research urban area is Zuidlanden, located in the south of Leeuwarden in the north of the Netherlands. The

High-Resolution Mapping of Urban Surface Water Using ZY-3 Multi-Spectral Imagery

Directory of Open Access Journals (Sweden)

Fangfang Yao

2015-09-01

Full Text Available Accurate information of urban surface water is important for assessing the role it plays in urban ecosystem services under the content of urbanization and climate change. However, high-resolution monitoring of urban water bodies using remote sensing remains a challenge because of the limitation of previous water indices and the dark building shadow effect. To address this problem, we proposed an automated urban water extraction method (UWEM which combines a new water index, together with a building shadow detection method. Firstly, we trained the parameters of UWEM using ZY-3 imagery of Qingdao, China. Then we verified the algorithm using five other sub-scenes (Aksu, Fuzhou, Hanyang, Huangpo and Huainan ZY-3 imagery. The performance was compared with that of the Normalized Difference Water Index (NDWI. Results indicated that UWEM performed significantly better at the sub-scenes with kappa coefficients improved by 7.87%, 32.35%, 12.64%, 29.72%, 14.29%, respectively, and total omission and commission error reduced by 61.53%, 65.74%, 83.51%, 82.44%, and 74.40%, respectively. Furthermore, UWEM has more stable performances than NDWI’s in a range of thresholds near zero. It reduces the over- and under-estimation issues which often accompany previous water indices when mapping urban surface water under complex environmental conditions.

Urban energy management today: Ten year compendium of UCETF programs. Products and expertise of the Urban Consortium Energy Task Force, 1979--1989

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

The reports listed in this Overview summarize projects conducted through the Urban Consortium Energy Task Force by local government staff who have defined and implemented many of the energy strategies described above. Reports from their projects illustrate effective approaches to plan and implement these strategies, as well as software tools, surveys, and technical instruments valuable to other local government officials conducting similar projects.

Unexpectedly high soil organic carbon stocks under impervious surfaces contributed by urban deep cultural layers

Science.gov (United States)

Bae, J.; Ryu, Y.

2017-12-01

The expansion of urban artificial structures has altered the spatial distribution of soil organic carbon (SOC) stocks. The majority of the urban soil studies within the land-cover types, however, focused on top soils despite the potential of deep soils to store large amounts of SOC. Here, we investigate vertical distribution of SOC stocks in both impervious surfaces (n = 11) and adjacent green spaces (n = 8) to a depth of 4 m with in an apartment complex area, Seoul, Republic of Korea. We found that more than six times differences in SOC stocks were observed at 0-1 m depth between the impervious surfaces (1.90 kgC m-2) and the green spaces (12.03 kgC m-2), but no significant differences appeared when comparing them at the depth of 0-4 m. We found "cultural layers" with the largest SOC stocks at 1-2 m depth in the impervious surfaces (15.85 kgC m-2) and 2-3 m depths in urban green spaces (12.52 kgC m-2). Thus, the proportions of SOC stocks at the 0-1 m depth to the total of 0-4 m depth were 6.83% in impervious surfaces and 32.15% in urban green spaces, respectively. The 13C and 15N stable isotope data with historical aerial photographs revealed that the cropland which existed before 1978 formed the SOC in the cultural layers. Our results highlight that impervious surface could hold large amount of SOC stock which has been overlooked in urban carbon cycles. We believe this finding will help city planners and policy makers to develop carbon management programs better towards sustainable urban ecosystems.

Impacts of urbanization on national transport and road energy use: Evidence from low, middle and high income countries

International Nuclear Information System (INIS)

Poumanyvong, Phetkeo; Kaneko, Shinji; Dhakal, Shobhakar

2012-01-01

Few attempts have been made to investigate quantitatively and systematically the impact of urbanization on transport energy use for countries of different stages of economic development. This paper examines the influence of urbanization on national transport and road energy use for low, middle and high income countries during 1975–2005, using the Stochastic Impacts by Regression on Population, Affluence and Technology (STIRPAT) model. After controlling for population size, income per capita and the share of services in the economy, the main results suggest that urbanization influences national transport and road energy use positively. However, the magnitude of its influence varies among the three income groups. Changes in urbanization appear to have a greater impact on transport and road energy use in the high income group than in the other groups. Surprisingly, the urbanization elasticities of transport and road energy use in the middle income group are smaller than those of the low income group. This study not only sheds further light on the existing literature, but also provides policy makers with insightful information on the link between urbanization and transport energy use at the three different stages of development. - Highlights: ► Overall, urbanization increases national transport and road energy use. ► Urbanization elasticities of transport energy use differ across development stages. ► Urbanization elasticities in high-income group are higher than in other groups.

Urban physics : effect of the micro-climate on comfort, health and energy demand

NARCIS (Netherlands)

Moonen, P.; Defraeye, T.W.J.; Dorer, V.; Blocken, B.J.E.; Carmeliet, J.E.

2012-01-01

The global trend towards urbanization explains the growing interest in the study of the modification of the urban climate due to the heat island effect and global warming, and its impact on energy use of buildings. Also urban comfort, health and durability, referring respectively to pedestrian

Optimal urban water conservation strategies considering embedded energy: coupling end-use and utility water-energy models.

Science.gov (United States)

Escriva-Bou, A.; Lund, J. R.; Pulido-Velazquez, M.; Spang, E. S.; Loge, F. J.

2014-12-01

Although most freshwater resources are used in agriculture, a greater amount of energy is consumed per unit of water supply for urban areas. Therefore, efforts to reduce the carbon footprint of water in cities, including the energy embedded within household uses, can be an order of magnitude larger than for other water uses. This characteristic of urban water systems creates a promising opportunity to reduce global greenhouse gas emissions, particularly given rapidly growing urbanization worldwide. Based on a previous Water-Energy-CO2 emissions model for household water end uses, this research introduces a probabilistic two-stage optimization model considering technical and behavioral decision variables to obtain the most economical strategies to minimize household water and water-related energy bills given both water and energy price shocks. Results show that adoption rates to reduce energy intensive appliances increase significantly, resulting in an overall 20% growth in indoor water conservation if household dwellers include the energy cost of their water use. To analyze the consequences on a utility-scale, we develop an hourly water-energy model based on data from East Bay Municipal Utility District in California, including the residential consumption, obtaining that water end uses accounts for roughly 90% of total water-related energy, but the 10% that is managed by the utility is worth over 12 million annually. Once the entire end-use + utility model is completed, several demand-side management conservation strategies were simulated for the city of San Ramon. In this smaller water district, roughly 5% of total EBMUD water use, we found that the optimal household strategies can reduce total GHG emissions by 4% and utility's energy cost over 70,000/yr. Especially interesting from the utility perspective could be the "smoothing" of water use peaks by avoiding daytime irrigation that among other benefits might reduce utility energy costs by 0.5% according to our

Effects of landscape composition and pattern on land surface temperature: An urban heat island study in the megacities of Southeast Asia.

Science.gov (United States)

Estoque, Ronald C; Murayama, Yuji; Myint, Soe W

2017-01-15

Due to its adverse impacts on urban ecological environment and the overall livability of cities, the urban heat island (UHI) phenomenon has become a major research focus in various interrelated fields, including urban climatology, urban ecology, urban planning, and urban geography. This study sought to examine the relationship between land surface temperature (LST) and the abundance and spatial pattern of impervious surface and green space in the metropolitan areas of Bangkok (Thailand), Jakarta (Indonesia), and Manila (Philippines). Landsat-8 OLI/TIRS data and various geospatial approaches, including urban-rural gradient, multiresolution grid-based, and spatial metrics-based techniques, were used to facilitate the analysis. We found a significant strong correlation between mean LST and the density of impervious surface (positive) and green space (negative) along the urban-rural gradients of the three cities, depicting a typical UHI profile. The correlation of impervious surface density with mean LST tends to increase in larger grids, whereas the correlation of green space density with mean LST tends to increase in smaller grids, indicating a stronger influence of impervious surface and green space on the variability of LST in larger and smaller areas, respectively. The size, shape complexity, and aggregation of the patches of impervious surface and green space also had significant relationships with mean LST, though aggregation had the most consistent strong correlation. On average, the mean LST of impervious surface is about 3°C higher than that of green space, highlighting the important role of green spaces in mitigating UHI effects, an important urban ecosystem service. We recommend that the density and spatial pattern of urban impervious surfaces and green spaces be considered in landscape and urban planning so that urban areas and cities can have healthier and more comfortable living urban environments. Copyright © 2016 Elsevier B.V. All rights reserved.

Seasonal and Spatial Variation of Surface Urban Heat Island Intensity in a Small Urban Agglomerate in Brazil

Directory of Open Access Journals (Sweden)

Elis Dener Lima Alves

2016-12-01

Full Text Available In recent years, SUHIs (surface urban heat islands have been greatly emphasized in urban climate studies, since it is one of the climate phenomena most influenced by human action. In this study, temporal and spatial variations of SUHIs in the cities of Ceres and Rialma (Brazil were investigated; satellite Landsat 8 TIRS/OLI images from 2013 to 2016 were used for this purpose. The results showed that in all seasons, two relationships were observed, one positive and one negative. An N D V I (Normalized Difference Vegetation Index of 0.2 is the divider of this relationship: up to this value, the relationship is positive, that is, the higher the N D V I value, the higher the surface temperature, while the relationship is negative at an N D V I greater than 0.2. There was high seasonal variation in the SUHIs, with the highest intensities recorded in the spring and summer (±12 °C, and the lowest in the winter. These temporal variations were attributed to the annual cycle of precipitation, which directly involves the robustness of the Cerrado vegetation. SUHIs occupied, on average, an area three times larger than the area of SUCIs (surface urban cool islands. The highest values of SUCIs were observed in water bodies and in valley bottoms. Overall, SUHIs showed high intensities; however, a more intense core area, such as in large cities, was not observed.

Remote sensing of impervious surface growth: A framework for quantifying urban expansion and re-densification mechanisms

Science.gov (United States)

Shahtahmassebi, Amir Reza; Song, Jie; Zheng, Qing; Blackburn, George Alan; Wang, Ke; Huang, Ling Yan; Pan, Yi; Moore, Nathan; Shahtahmassebi, Golnaz; Sadrabadi Haghighi, Reza; Deng, Jing Song

2016-04-01

A substantial body of literature has accumulated on the topic of using remotely sensed data to map impervious surfaces which are widely recognized as an important indicator of urbanization. However, the remote sensing of impervious surface growth has not been successfully addressed. This study proposes a new framework for deriving and summarizing urban expansion and re-densification using time series of impervious surface fractions (ISFs) derived from remotely sensed imagery. This approach integrates multiple endmember spectral mixture analysis (MESMA), analysis of regression residuals, spatial statistics (Getis_Ord) and urban growth theories; hence, the framework is abbreviated as MRGU. The performance of MRGU was compared with commonly used change detection techniques in order to evaluate the effectiveness of the approach. The results suggested that the ISF regression residuals were optimal for detecting impervious surface changes while Getis_Ord was effective for mapping hotspot regions in the regression residuals image. Moreover, the MRGU outputs agreed with the mechanisms proposed in several existing urban growth theories, but importantly the outputs enable the refinement of such models by explicitly accounting for the spatial distribution of both expansion and re-densification mechanisms. Based on Landsat data, the MRGU is somewhat restricted in its ability to measure re-densification in the urban core but this may be improved through the use of higher spatial resolution satellite imagery. The paper ends with an assessment of the present gaps in remote sensing of impervious surface growth and suggests some solutions. The application of impervious surface fractions in urban change detection is a stimulating new research idea which is driving future research with new models and algorithms.

Impact of Urban Climate Landscape Patterns on Land Surface Temperature in Wuhan, China

Directory of Open Access Journals (Sweden)

Yasha Wang

2017-09-01

Full Text Available Facing urban warming, mitigation and adaptation strategies are not efficient enough to tackle excessive urban heat, especially at the local scale. The local climate zone (LCZ classification scheme is employed to examine the diversity and complexity of the climate response within a city. This study suggests that zonal practice could be an efficient way to bridge the knowledge gap between climate research and urban planning. Urban surfaces classified by LCZ are designated as urban climate landscapes, which extends the LCZ concept to urban planning applications. Selecting Wuhan as a case study, we attempt to explore the climatic effect of landscape patterns. Thermal effects are compared across the urban climate landscapes, and the relationships between patch metrics and land surface temperature (LST are quantified. Results indicate that climate landscape layout is a considerable factor impacting local urban climate. For Wuhan, 500 m is an optimal scale for exploring landscape pattern-temperature relationships. Temperature contrast between surrounding landscape patches has a major influence on LST. Generally, fragmental landscape patches contribute to heat release. For most climate landscape types, patch metrics also have a significant effect on thermal response. When three metrics are included as predictive variables, 53.3% of the heating intensity variation can be explained for the Large Lowrise landscape, while 57.4% of the cooling intensity variation can be explained for the Water landscape. Therefore, this article claims that land-based layout optimization strategy at local scale, which conforms to planning manner, should be taken into account in terms of heat management.

Differentiated surface fungal communities at point of harvest on apple fruits from rural and peri-urban orchards.

Science.gov (United States)

Shen, Youming; Nie, Jiyun; Li, Zhixia; Li, Haifei; Wu, Yonglong; Dong, Yafeng; Zhang, Jianyi

2018-02-01

The diverse fungal communities that colonize fruit surfaces are closely associated with fruit development, preservation and quality control. However, the overall fungi adhering to the fruit surface and the inference of environmental factors are still unknown. Here, we characterized the fungal signatures on apple surfaces by sequencing internal transcribed spacer 1 (ITS1) region. We collected the surface fungal communities from apple fruits cultivated in rural and peri-urban orchards. A total of 111 fungal genera belonging to 4 phyla were identified, showing remarkable fungal diversity on the apple surface. Comparative analysis of rural samples harboured higher fungal diversity than those from peri-urban orchards. In addition, fungal composition varied significantly across apple samples. At the genus level, the protective genera Coniothyrium, Paraphaeosphaeria and Periconia were enriched in rural samples. The pathogenic genera Acremonium, Aspergillus, Penicillium and Tilletiposis were enriched in peri-urban samples. Our findings indicate that rural samples maintained more diverse fungal communities on apple surfaces, whereas peri-urban-planted apple carried potential pathogenic risks. This study sheds light on ways to improve fruit cultivation and disease prevention practices.

Does financial development increase energy consumption? The role of industrialization and urbanization in Tunisia

International Nuclear Information System (INIS)

Shahbaz, Muhammad; Lean, Hooi Hooi

2012-01-01

This paper assesses the relationship among energy consumption, financial development, economic growth, industrialization and urbanization in Tunisia from 1971 to 2008. The autoregressive distributed lag bounds testing approach to cointegration and Granger causality tests is employed for the analysis. The result confirms the existence of long-run relationship among energy consumption, economic growth, financial development, industrialization and urbanization in Tunisia. Long-run bidirectional causalities are found between financial development and energy consumption, financial development and industrialization, and industrialization and energy consumption. Hence, sound and developed financial system that can attract investors, boost the stock market and improve the efficiency of economic activities should be encouraged in the country. Nevertheless, promoting industrialization and urbanization can never be left out from the process of development. We add light to policy makers with the role of financial development, industrialization and urbanization in the process of economic development. - Highlights: ► We find the existence of long-run relationship among variables. ► Financial development is positively related to energy consumption. ► Bidirectional causal relationship between financial development and energy consumption. ► Sound and developed financial system should be encouraged.

Modeling Linkages Between Effective Impervious Surface and Urban Vegetation Productivity in Semi-arid Environments

Science.gov (United States)

Shields, C. A.; Tague, C.

2010-12-01

With a majority of the world's population now living in urban areas, the role of vegetation in urban ecosystems warrants increased attention. We address the question of how the fine scale (significantly impact the productivity of vegetation and uptake of C and N. To gain insight into how landscape features influence vegetation productivity, we use a coupled ecohydrogic model to estimate impacts of the amount and arrangement of impervious surfaces on vegetation water use. We use the model to explore how concepts from research in natural semi-arid ecosystems can be applied in the urban context. Ecological research in semi-arid ecosystems has shown that the arrangement of vegetated and bare surfaces plays a key role in regulating both runoff and ecosystem water use and productivity. Systems that include a mixture of bare and vegetated surfaces, for example, tend to show less runoff and more productivity than those with more homogeneous cover. In some instances, patchiness of bare and vegetated surfaces is more important than total vegetated area in determining rates of runoff and vegetation use of rainfall. In an urban context, impervious surfaces can be viewed as analogous to the bare surfaces present in undeveloped ecosystems. We consider not only the total impervious area (TIA), but also the effect of impervious area with a direct hydrologic connection to the stream network, effective impervious area (EIA). While increases in total impervious area (TIA) have been widely shown to impact catchment hydrology, the role of effective impervious area (EIA) has been less extensively studied. A consensus is emerging from the literature that EIA is as important or even more important than TIA as an indicator of catchment response to urbanization. Ecohydrologic models offer a tool to quantify the role of EIA on water availability and plant productivity and demonstrate the potential of urban areas to act as C or N sinks (and minimize the impacts such as increased storm runoff

Energy saving and recovery measures in integrated urban water systems

Science.gov (United States)

Freni, Gabriele; Sambito, Mariacrocetta

2017-11-01

The present paper describes different energy production, recovery and saving measures which can be applied in an integrated urban water system. Production measures are often based on the installation of photovoltaic systems; the recovery measures are commonly based on hydraulic turbines, exploiting the available pressure potential to produce energy; saving measures are based on substitution of old pumps with higher efficiency ones. The possibility of substituting some of the pipes of the water supply system can be also considered in a recovery scenario in order to reduce leakages and recovery part of the energy needed for water transport and treatment. The reduction of water losses can be obtained through the Active Leakage Control (ALC) strategies resulting in a reduction in energy consumption and in environmental impact. Measures were applied to a real case study to tested it the efficiency, i.e., the integrated urban water system of the Palermo metropolitan area in Sicily (Italy).

Managing urban energy system: A case of Suzhou in China

International Nuclear Information System (INIS)

Liang Sai; Zhang Tianzhu

2011-01-01

Managing urban energy system is vital for energy conservation and CO 2 reduction. Integrating energy input-output model with carbon emission pinch analysis, we propose a framework for managing urban energy system. This framework could analyze current energy demands and CO 2 emissions, predict their future possibilities and optimize energy mix of key sectors under CO 2 emission constraints. Key sectors are identified by the energy input-output table from both direct and accumulative perspectives. Moreover, taking Suzhou, a typical manufacturing center and export-oriented city in China, as a case example, energy metabolism of Suzhou in 2020 is predicted using energy input-output model. And three sectors named Coking, Smelting and pressing of metals and Production and supply of electric power are identified to have big effects on CO 2 emissions. Subsequently, energy mix of three identified key sectors is optimized under CO 2 emission constraints by the carbon emission pinch analysis. According to the results, clean energy sources will occupy a great position in Suzhou's future energy demands. And the reuse of wastes as energy sources should be limited to achieve CO 2 mitigation targets. Finally, policy implications of results and future work are discussed. - Research highlights: → We construct a framework for sustainable energy system management. → We apply the framework in a typical manufacturing center named Suzhou in China. → Key sectors for CO 2 emissions are identified, and energy mix is optimized. → Policy implications of results and future work are discussed.

Spatial Modeling of Urban Vegetation and Land Surface Temperature: A Case Study of Beijing

Directory of Open Access Journals (Sweden)

Chudong Huang

2015-07-01

Full Text Available The coupling relationship between urban vegetation and land surface temperature (LST has been heatedly debated in a variety of environmental studies. This paper studies the urban vegetation information and LST by utilizing a series of remote sensing imagery covering the period from 1990 to 2007. Their coupling relationship is analyzed, in order to provide the basis for ecological planning and environment protection. The results show that the normalized difference vegetation index (NDVI, urban vegetation abundance (UVA and urban forest abundance (UFA are negatively correlated with LST, which means that both urban vegetation and urban forest are capable in decreasing LST. The apparent influence of urban vegetation and urban forest on LST varies with the spatial resolution of the imagery, and peaks at the resolutions ranging from 90 m to 120 m.

3. national sittings on energy ''energy, urban mobility,... tomorrow: which responsibilities for the local governments?''; 3. assises nationales de l'energie. ''Energie, mobilite urbaine,... demain: quelles responsabilites pour les collectivites locales?''

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This conference deals with the local government policy concerning the energy mastership of the transportation sector. Sixteen workshops discussed on the problem of the urban mobility in an environmental quality context: legal provisions affecting the energy mastership, mobility in the urban area, regulations, clean technologies enhancement, the public information impact on the energy consumption and the financial means. (A.L.B.)

Urban Heat Islands

Science.gov (United States)

Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.; Estes, Maury G.

2011-01-01

It is estimated that by the year 2025, 80% of the world's population will live in cities. This conversion of the natural landscape vegetation into man-made urban structures such as roads and buildings drastically alter the regional surface energy budgets, hydrology, precipitation patterns, and meteorology. Research studies from many cities have documented these effects range from decreases in air quality, increased energy consumption and alteration of regional climate to direct effects on human health.

Proceedings: energy from urban wastes workshop, Washington, DC, September 11-12, 1978

Energy Technology Data Exchange (ETDEWEB)

Cohen, A.S.; Brooks, C. (eds.)

1979-06-01

This workshop, for members of public interest groups, was sponsored by DOE's Urban Waste Technology Branch to provide information on the use of urban waste as an energy resource. A separate abstract was prepared for each of seven presentations plus the Summary of discussions. Two acts are included as appendices: (1) Public Law 95-238: Department of Energy Act of 1978 - Civilian Applications; and (2) Public Law 94-580: Resource Conservation and Recovery Act of 1976.

Impacts of land use and land cover on surface and air temperature in urban landscapes

Science.gov (United States)

Crum, S.; Jenerette, D.

2015-12-01

Accelerating urbanization affects regional climate as the result of changing land cover and land use (LCLU). Urban land cover composition may provide valuable insight into relationships among urbanization, air, and land-surface temperature (Ta and LST, respectively). Climate may alter these relationships, where hotter climates experience larger LULC effects. To address these hypotheses we examined links between Ta, LST, LCLU, and vegetation across an urban coastal to desert climate gradient in southern California, USA. Using surface temperature radiometers, continuously measuring LST on standardized asphalt, concrete, and turf grass surfaces across the climate gradient, we found a 7.2°C and 4.6°C temperature decrease from asphalt to vegetated cover in the coast and desert, respectively. There is 131% more temporal variation in asphalt than turf grass surfaces, but 37% less temporal variation in concrete than turf grass. For concrete and turf grass surfaces, temporal variation in temperature increased from coast to desert. Using ground-based thermal imagery, measuring LST for 24 h sequences over citrus orchard and industrial use locations, we found a 14.5°C temperature decrease from industrial to orchard land use types (38.4°C and 23.9°C, respectively). Additionally, industrial land use types have 209% more spatial variation than orchard (CV=0.20 and 0.09, respectively). Using a network of 300 Ta (iButton) sensors mounted in city street trees throughout the region and hyperspectral imagery data we found urban vegetation greenness, measured using the normalized difference vegetation index (NDVI), was negatively correlated to Ta at night across the climate gradient. Contrasting previous findings, the closest coupling between NDVI and Ta is at the coast from 0000 h to 0800 h (highest r2 = 0.6, P urbanized regions of southern California, USA decrease Ta and LST and spatial variation in LST, while built surfaces and land uses have the opposite effect. Furthermore

A global analysis of the urban heat island effect based on multisensor satellite data

Science.gov (United States)

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.

The implementation of biofiltration systems, rainwater tanks and urban irrigation in a single-layer urban canopy model

Science.gov (United States)

Demuzere, Matthias; Coutts, Andrew; Goehler, Maren; Broadbent, Ashley; Wouters, Hendrik; van Lipzig, Nicole; Gebert, Luke

2015-04-01

Urban vegetation is generally considered as a key tool to modify the urban energy balance through enhanced evapotranspiration (ET). Given that vegetation is most effective when it is healthy, stormwater harvesting and retention strategies (such as water sensitive urban design) could be used to support vegetation and promote ET. This study presents the implementation of a vegetated lined bio-filtration system (BFS) combined with a rainwater tank (RWT) and urban irrigation system in the single-layer urban canopy model Community Land Model-Urban. Runoff from roof and impervious road surface fractions is harvested and used to support an adequate soil moisture level for vegetation in the BFS. In a first stage, modelled soil moisture dynamics are evaluated and found reliable compared to observed soil moisture levels from biofiltration pits in Smith Street, Melbourne (Australia). Secondly, the impact of BFS, RWT and urban irrigation on ET is illustrated for a two-month period in 2012 using varying characteristics for all components. Results indicate that (i) a large amount of stormwater is potentially available for indoor and outdoor water demands, including irrigation of urban vegetation, (ii) ET from the BFS is an order of magnitude larger compared to the contributions from the impervious surfaces, even though the former only covers 10% of the surface fraction and (iii) attention should be paid to the cover fraction and soil texture of the BFS, size of the RWT and the surface fractions contributing to the collection of water in the RWT. Overall, this study reveals that this model development can effectuate future research with state-of-the-art urban climate models to further explore the benefits of vegetated biofiltration systems as a water sensitive urban design tool optimised with an urban irrigation system to maintain healthy vegetation.

Comparison of household consumption and regional production approaches to assess urban energy use and implications for policy

International Nuclear Information System (INIS)

Baynes, Timothy; Lenzen, Manfred; Steinberger, Julia K.; Bai Xuemei

2011-01-01

Assessment of urban energy use may proceed by a number of methods. Here we derive an energy account from local statistics, and compare them with an input output (IO) analysis as applied to Melbourne, Australia. These approaches highlight different aspects of urban energy use and comparable outputs are presented together to assess consistency, to identify complementarities and discuss the insight each approach brings to understanding urban energy. The IO method captures the direct and embodied primary energy requirements of local household expenditure (235.8 GJ/capita/year) while the regional assessment more directly accounts for local production activity (258.1 GJ/capita/year). The parity of these results is unexpected for a developed city with a strong tertiary sector. Sectoral detail reveals differences between the primary energy required by Melbourne's economic structure and that ultimately required through the full supply chain relating to household expenditure. This is accompanied by an IO analysis of the geography of Melbourne's 'energy catchment'. It is suggested that the IO consumption and regional production approaches have particular relevance to policies aimed at consumption behaviour and economic (re)structuring, respectively. Their complementarity further suggests that a combined analysis would be valuable in understanding urban energy futures and economic transitions elsewhere. - Highlights: → We compare an IO approach and a regional assessment of an urban energy use case. → Unusually, regional assessment of the primary energy use exceeds that from IO. → Sectoral and geographical detail reveals the urban consumption/production character. → We discuss the relative merits and policy utility of the different methods. → A combined approach is recommended for urban energy and economic transitions.

Wind Tunnel Study on Flows over Various Two-dimensional Idealized Urban-liked Surfaces

Science.gov (United States)

Ho, Yat-Kiu; Liu, Chun-Ho

2013-04-01

Extensive human activities (e.g. increased traffic emissions) emit a wide range of pollutants resulting in poor urban area air quality. Unlike open, flat and homogenous rural terrain, urban surface is complicated by the presence of buildings, obstacles and narrow streets. The irregular urban surfaces thus form a random roughness that further modifies the near-surface flows and pollutant dispersion. In this study, a physical modelling approach is employed to commence a series of wind tunnel experiments to study the urban-area air pollution problems. The flow characteristics over different hypothetical urban roughness surfaces were studied in a wind tunnel in isothermal conditions. Preliminary experiments were conducted based on six types of idealized two-dimensional (2D) street canyon models with various building-height-to-street-width (aspect) ratios (ARs) 1, 1/2, 1/4, 1/8, 1/10 and 1/12. The main instrumentation is an in-house 90o X-hotwire anemometry. In each set of configuration, a sampling street canyon was selected near the end of the streamwise domain. Its roof level, i.e. the transverse between the mid points of the upstream and downstream buildings, was divided into eight segments. The measurements were then recorded on the mid-plane of the spannwise domain along the vertical profile (from building roof level to the ceiling of wind tunnel) of the eight segments. All the data acquisition processes were handled by the NI data acquisition modules, NI 9239 and CompactDAQ-9188 hardware. Velocity calculation was carried out in the post-processing stage on a digital computer. The two-component flow velocities and velocity fluctuations were calculated at each sampling points, therefore, for each model, a streamwise average of eight vertical profiles of mean velocity and velocity fluctuations was presented. A plot of air-exchange rate (ACH) against ARs was also presented in order to examine the ventilation performance of different tested models. Preliminary results

Transfer of glyphosate and its degradate AMPA to surface waters through urban sewerage systems.

Science.gov (United States)

Botta, Fabrizio; Lavison, Gwenaëlle; Couturier, Guillaume; Alliot, Fabrice; Moreau-Guigon, Elodie; Fauchon, Nils; Guery, Bénédicte; Chevreuil, Marc; Blanchoud, Hélène

2009-09-01

A study of glyphosate and aminomethyl phosphonic acid (AMPA) transfer in the Orge watershed (France) was carried out during 2007 and 2008. Water samples were collected in surface water, wastewater sewer, storm sewer and wastewater treatment plant (WWTP). These two molecules appeared to be the most frequently detected ones in the rivers and usually exceeded the European quality standard concentrations of 0.1microg L(-1) for drinking water. The annual glyphosate estimated load was 1.9 kg year(-1) upstream (agricultural zone) and 179.5 kg year(-1) at the catchment outlet (urban zone). This result suggests that the contamination of this basin by glyphosate is essentially from urban origin (road and railway applications). Glyphosate reached surface water prevalently through storm sewer during rainfall event. Maximum concentrations were detected in storm sewer just after a rainfall event (75-90 microg L(-1)). High concentrations of glyphosate in surface water during rainfall events reflected urban runoff impact. AMPA was always detected in the sewerage system. This molecule reached surface water mainly via WWTP effluent and also through storm sewer. Variations in concentrations of AMPA during hydrological episodes were minor compared to glyphosate variations. Our study highlights that AMPA and glyphosate origins in urban area are different. During dry period, detergent degradation seemed to be the major AMPA source in wastewater.

Energy saving and emission reduction of China's urban district heating

International Nuclear Information System (INIS)

Chen, Xia; Wang, Li; Tong, Lige; Sun, Shufeng; Yue, Xianfang; Yin, Shaowu; Zheng, Lifang

2013-01-01

China's carbon dioxide (CO 2 ) emission ranks highest in the world. China is committed to reduce its CO 2 emission by 40% to 45% from the 2005 levels by 2020. To fulfill the target, China's CO 2 emission reduction must exceed 6995 million tons. Energy consumption and CO 2 emission of China's urban district heating (UDH) are increasing. The current policy implemented to improve UDH focuses on replacing coal with natural gas to reduce energy consumption and CO 2 emission to some extent. This paper proposes that heat pump heating (HPH) could serve as a replacement for UDH to help realize energy-saving and emission-reduction goals to a greater extent. The paper also analyzes the impact of this replacement on the heating and power generation sectors. The results show that replacing coal-based UDH with HPH decreases energy consumption and CO 2 emission by 43% in the heating sector. In the power generation sector, the efficiency of power generation at the valley electricity time increases by 0.512%, and the ratio of peak–valley difference decreases by 16.5%. The decreases in CO 2 emission from the heating and power generation sectors cumulatively account for 5.55% of China's total CO 2 emission reduction target in 2020. - Highlights: ► Replacing urban district heating with heat pump heating. ► Impact of heat pump heating on heating and power generation sectors. ► Potential of energy saving and emission reduction for heat pump heating. ► China should adjust current urban heating strategy

Energy and exergy utilizations of the Chinese urban residential sector

International Nuclear Information System (INIS)

Liu, Yanfeng; Li, Yang; Wang, Dengjia; Liu, Jiaping

2014-01-01

Highlights: • The energy and exergy use in China’s urban residential sector between 2002 and 2011 are analyzed. • The primary locations and causes of energy and exergy losses in the CURS are identified. • The large gap between the energy and exergy efficiencies implies great potential for energy saving. • The exergy utilization can be improved by using appropriate technology, management and policy. - Abstract: In this paper, the energy and exergy utilizations in the Chinese urban residential sector (CURS) are analyzed by considering the energy and exergy flows for the years between 2002 and 2011. The energy and exergy efficiencies of this sector are calculated to examine the potential for advancing the ‘true’ energy efficiency and determine the real energy losses. The results demonstrate large differences between the overall energy efficiencies (62.8–70.2%) and the exergy efficiencies (11.0–12.2%) for the years analyzed. The sizable gap between the energy and exergy efficiencies implies a high potential for energy savings in the CURS. Future energy saving strategies should pay more attention to the improvement in exergy efficiencies. Moreover, it is found that direct fuel use constituted the primary exergy losses of the CURS; coal-fired boiler heating systems cause approximately 35% of the total exergy losses. Gas stoves, cogeneration systems, coal stoves and gas water heaters constitute 15.3%, 15%, 5.5% and 4.9% of the total exergy losses, respectively

Simulation of trace metals and PAH atmospheric pollution over Greater Paris: Concentrations and deposition on urban surfaces

Science.gov (United States)

Thouron, L.; Seigneur, C.; Kim, Y.; Legorgeu, C.; Roustan, Y.; Bruge, B.

2017-10-01

Urban areas can be subject not only to poor air quality, but also to contamination of other environmental media by air pollutants. Here, we address the potential transfer of selected air pollutants (two metals and three PAH) to urban surfaces. To that end, we simulate meteorology and air pollution from Europe to a Paris suburban neighborhood, using a four-level one-way nesting approach. The meteorological and air quality simulations use urban canopy sub-models in order to better represent the effect of the urban morphology on the air flow, atmospheric dispersion, and deposition of air pollutants to urban surfaces. This modeling approach allows us to distinguish air pollutant deposition among various urban surfaces (roofs, roads, and walls). Meteorological model performance is satisfactory, showing improved results compared to earlier simulations, although precipitation amounts are underestimated. Concentration simulation results are also satisfactory for both metals, with a fractional bias Paris region. The model simulation results suggest that both wet and dry deposition processes need to be considered when estimating the transfer of air pollutants to other environmental media. Dry deposition fluxes to various urban surfaces are mostly uniform for PAH, which are entirely present in fine particles. However, there is significantly less wall deposition compared to deposition to roofs and roads for trace metals, due to their coarse fraction. Meteorology, particle size distribution, and urban morphology are all important factors affecting air pollutant deposition. Future work should focus on the collection of data suitable to evaluate the performance of atmospheric models for both wet and dry deposition with fine spatial resolution.

A wind tunnel study of flows over idealised urban surfaces with roughness sublayer corrections

Science.gov (United States)

Ho, Yat-Kiu; Liu, Chun-Ho

2017-10-01

Dynamics in the roughness (RSLs) and inertial (ISLs) sublayers in the turbulent boundary layers (TBLs) over idealised urban surfaces are investigated analytically and experimentally. In this paper, we derive an analytical solution to the mean velocity profile, which is a continuous function applicable to both RSL and ISL, over rough surfaces in isothermal conditions. Afterwards, a modified mixing-length model for RSL/ISL transport is developed that elucidates how surface roughness affects the turbulence motions. A series of wind tunnel experiments are conducted to measure the vertical profiles of mean and fluctuating velocities, together with momentum flux over various configurations of surface-mounted ribs in cross flows using hot-wire anemometry (HWA). The analytical solution agrees well with the wind tunnel result that improves the estimate to mean velocity profile over urban surfaces and TBL dynamics as well. The thicknesses of RSL and ISL are calculated by monitoring the convergence/divergence between the temporally averaged and spatio-temporally averaged profiles of momentum flux. It is found that the height of RSL/ISL interface is a function of surface roughness. Examining the direct, physical influence of roughness elements on near-surface RSL flows reveals that the TBL flows over rough surfaces exhibit turbulence motions of two different length scales which are functions of the RSL and ISL structure. Conclusively, given a TBL, the rougher the surface, the higher is the RSL intruding upward that would thinner the ISL up to 50 %. Therefore, the conventional ISL log-law approximation to TBL flows over urban surfaces should be applied with caution.

Influence of Urban Microclimate on Air-Conditioning Energy Needs and Indoor Thermal Comfort in Houses

Directory of Open Access Journals (Sweden)

Feng-Chi Liao

2015-01-01

Full Text Available A long-term climate measurement was implemented in the third largest city of Taiwan, for the check of accuracy of morphing approach on generating the hourly data of urban local climate. Based on observed and morphed meteorological data, building energy simulation software EnergyPlus was used to simulate the cooling energy consumption of an air-conditioned typical flat and the thermal comfort level of a naturally ventilated typical flat. The simulated results were used to quantitatively discuss the effect of urban microclimate on the energy consumption as well as thermal comfort of residential buildings. The findings of this study can serve as a reference for city planning and energy management divisions to study urban sustainability strategies in the future.

Evaluating the impact of built environment characteristics on urban boundary layer dynamics using an advanced stochastic approach

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J. Song

2016-05-01

Full Text Available Urban land–atmosphere interactions can be captured by numerical modeling framework with coupled land surface and atmospheric processes, while the model performance depends largely on accurate input parameters. In this study, we use an advanced stochastic approach to quantify parameter uncertainty and model sensitivity of a coupled numerical framework for urban land–atmosphere interactions. It is found that the development of urban boundary layer is highly sensitive to surface characteristics of built terrains. Changes of both urban land use and geometry impose significant impact on the overlying urban boundary layer dynamics through modification on bottom boundary conditions, i.e., by altering surface energy partitioning and surface aerodynamic resistance, respectively. Hydrothermal properties of conventional and green roofs have different impacts on atmospheric dynamics due to different surface energy partitioning mechanisms. Urban geometry (represented by the canyon aspect ratio, however, has a significant nonlinear impact on boundary layer structure and temperature. Besides, managing rooftop roughness provides an alternative option to change the boundary layer thermal state through modification of the vertical turbulent transport. The sensitivity analysis deepens our insight into the fundamental physics of urban land–atmosphere interactions and provides useful guidance for urban planning under challenges of changing climate and continuous global urbanization.

Urban energy consumption and related carbon emission estimation: a study at the sector scale

Science.gov (United States)

Lu, Weiwei; Chen, Chen; Su, Meirong; Chen, Bin; Cai, Yanpeng; Xing, Tao

2013-12-01

With rapid economic development and energy consumption growth, China has become the largest energy consumer in the world. Impelled by extensive international concern, there is an urgent need to analyze the characteristics of energy consumption and related carbon emission, with the objective of saving energy, reducing carbon emission, and lessening environmental impact. Focusing on urban ecosystems, the biggest energy consumer, a method for estimating energy consumption and related carbon emission was established at the urban sector scale in this paper. Based on data for 1996-2010, the proposed method was applied to Beijing in a case study to analyze the consumption of different energy resources (i.e., coal, oil, gas, and electricity) and related carbon emission in different sectors (i.e., agriculture, industry, construction, transportation, household, and service sectors). The results showed that coal and oil contributed most to energy consumption and carbon emission among different energy resources during the study period, while the industrial sector consumed the most energy and emitted the most carbon among different sectors. Suggestions were put forward for energy conservation and emission reduction in Beijing. The analysis of energy consumption and related carbon emission at the sector scale is helpful for practical energy saving and emission reduction in urban ecosystems.

The Effectiveness of Light Shelf in Tropical Urban Context

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Binarti Floriberta

2016-12-01

Full Text Available Light shelf was developed to create uniform indoor illuminance. However, in hot climates the unshaded clerestory above the shelf transmits high solar heat gain. In dense urban context, these advantages and disadvantages might vary regarding the context and position of the fenestration. This study employed an integrated energy simulation software to investigate the effectiveness of light shelf application in a tropical urban context in terms of building energy consumption. Radiance and EnergyPlus based simulations performed the effects of urban canyon aspect ratio and external surface albedo on the daylighting performances, space cooling load, as well as the lighting energy consumption of the building equipped with lightshelves in 2 humid tropical cities. Comparison of the energy performances of 3 fenestration systems, i.e. fenestration without any shading device, with overhangs, and with light shelves, yielded some recommendations concerning the best application of light shelf on the certain floor levels and aspect ratio of the urban context.

The Urban Fabric of the City as Its Affects Thermal Energy Responses Derived from Remote Sensing Data

Science.gov (United States)

Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G., Jr.

2000-01-01

The physical geography of the city affects numerous aspects of its interlinked biophysical, social, and land-atmosphere characteristics - those attributes that come together to form the total urban environment. One approach to studying the multitude of interactions that occur as a result of urbanization is to view the city from a systems ecology perspective, where energy and material cycle into and out of the urban milieu. Thus, the urban ecosystem is synergistic in linking land, air, water, and living organisms in a vast network of interrelated physical, human, and biological process. Given the number and the shear complexity of the exchanges and, ultimately, their effects, that occur within the urban environment, we are focusing our research on looking at how the morphology or urban fabric of the city, drives thermal energy exchanges across the urban landscape. The study of thermal energy attributes for different cities provides insight into how thermal fluxes and characteristics are partitioned across the city landscape in response to each city's morphology. We are using thermal infrared remote sensing data obtained at a high spatial resolution from aircraft, along with satellite data, to identify and quantify thermal energy characteristics for 4 U.S. cities: Atlanta, GA, Baton Rouge, LA, Salt Lake City, UT, and Sacramento, CA. Analysis of how thermal energy is spatially distributed across the urban landscapes for these cities provides a unique perspective for understanding how the differing morphology of cities forces land-atmosphere exchanges, such as the urban heat island effect, as well as related meteorological and air quality interactions. Keyword: urban ecosystems, remote sensing, urban heat island

An energy and mortality impact assessment of the urban heat island in the US

International Nuclear Information System (INIS)

Lowe, Scott A.

2016-01-01

Increased summer energy use and increased summer heat related mortality are the two most cited detrimental impacts of the urban heat island (UHI). An assessment of these impacts was made that considered the annual impact of the UHI, not just the summer impact. It was found that in north of the US there was a net decrease in energy use from the UHI, as heating energy reductions were larger than the increase in cooling energy. In the south there was a net energy increase from the UHI. The impact of the UHI on heat related deaths was an estimated increase of 1.1 deaths per million people. The impact of the UHI on cold related deaths was an estimated decrease of 4.0 deaths per million people. These estimates are caveated by the acknowledgement that compounding factors influence mortality. Hypothermia related death rates were three times higher in rural areas than urban areas. This is surprising as the homeless population is usually considered the most at risk, yet they mostly live in urban areas. - Highlights: • The urban heat island (UHI) may actually be beneficial in colder cities in the US in terms of energy use • The UHI may cause an increase in heat related mortality of ~ 1 deaths per million • In winter the UHI may decrease cold related mortality by ~ 4 deaths per million • Cold related death rates were 3 times higher in rural areas although the homeless population live mainly in urban areas

An energy and mortality impact assessment of the urban heat island in the US

Energy Technology Data Exchange (ETDEWEB)

Lowe, Scott A., E-mail: Scott.lowe@manhattan.edu

2016-01-15

Increased summer energy use and increased summer heat related mortality are the two most cited detrimental impacts of the urban heat island (UHI). An assessment of these impacts was made that considered the annual impact of the UHI, not just the summer impact. It was found that in north of the US there was a net decrease in energy use from the UHI, as heating energy reductions were larger than the increase in cooling energy. In the south there was a net energy increase from the UHI. The impact of the UHI on heat related deaths was an estimated increase of 1.1 deaths per million people. The impact of the UHI on cold related deaths was an estimated decrease of 4.0 deaths per million people. These estimates are caveated by the acknowledgement that compounding factors influence mortality. Hypothermia related death rates were three times higher in rural areas than urban areas. This is surprising as the homeless population is usually considered the most at risk, yet they mostly live in urban areas. - Highlights: • The urban heat island (UHI) may actually be beneficial in colder cities in the US in terms of energy use • The UHI may cause an increase in heat related mortality of ~ 1 deaths per million • In winter the UHI may decrease cold related mortality by ~ 4 deaths per million • Cold related death rates were 3 times higher in rural areas although the homeless population live mainly in urban areas.

Does urbanization affect energy intensities across provinces in China?Long-run elasticities estimation using dynamic panels with heterogeneous slopes

International Nuclear Information System (INIS)

Ma, Ben

2015-01-01

Although there has been extensive debate in the literature that addresses the impact of urbanization on total energy use, the relative magnitude of each impact channel has not been empirically examined and urbanization's effects on energy transition dynamics in China remains unknown. Using panel datasets at the provincial level from 1986 to 2011, this paper employs dynamic models to investigate both the long-run and short-run elasticities of urbanization on energy intensities and the most significant impact channel is identified. Coal intensity and electricity intensity are also modeled to reveal energy transition dynamics driven by urbanization. A set of newly developed regression techniques, namely well-performed common correlated effects mean group (CCEMG) and augmented mean group (AMG) estimators, are used to treat residual cross-sectional dependence, nonstationary residuals, and unlikely-to-hold homogeneous slope assumptions. The results obtained verify that the net effects of urbanization on overall energy intensity and electricity intensity are statistically positive, with long-run elasticities of 0.14% to 0.37% and 0.23% to 0.29%, respectively, whereas China's urbanization does not significantly increase coal intensity. The fact that short-run elasticities account for a majority of corresponding long-run values indicates that the short-run effect, that is, indirect energy use induced by urban infrastructures is the most significant impact channel of urbanization on energy use in China. An energy transition from high-pollution coal to clean electricity is also present in China, although the fundamental transition to renewable energy is still in its infancy. From a regional perspective, urbanization exerts asymmetric impacts on provincial energy use so that energy policies associated with urbanization should be province-specific. The findings also illustrate that for a panel dataset on regional dimension within large and fast-growing economies such

Urban percent impervious surface and its relationship with land surface temperature in Yantai City, China

International Nuclear Information System (INIS)

Yu, Xinyang; Lu, Changhe

2014-01-01

This study investigated percent impervious surface area (PISA) extracted by a four-endmember normalized spectral mixture analysis (NSMA) method and evaluated the reliability of PISA as an indicator of land surface temperature (LST). Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) images for Yantai city, eastern China obtained from USGS were used as the main data source. The results demonstrated that four-endmember NSMA method performed better than the typical three-endmember one, and there was a strong linear relationship between LST and PISA for the two images, which suggest percent impervious surface area provides an alternative parameter for analyzing LST quantitatively in urban areas

Modification of Surface Energy via Direct Laser Ablative Surface Patterning

Science.gov (United States)

Wohl, Christopher J., Jr. (Inventor); Belcher, Marcus A. (Inventor); Connell, John W. (Inventor); Hopkins, John W. (Inventor)

2015-01-01

Surface energy of a substrate is changed without the need for any template, mask, or additional coating medium applied to the substrate. At least one beam of energy directly ablates a substrate surface to form a predefined topographical pattern at the surface. Each beam of energy has a width of approximately 25 micrometers and an energy of approximately 1-500 microJoules. Features in the topographical pattern have a width of approximately 1-500 micrometers and a height of approximately 1.4-100 micrometers.

Surface energy anisotropy of tungsten

Energy Technology Data Exchange (ETDEWEB)

Kumar, R; Grenga, H E [Georgia Inst. of Tech., Atlanta (USA). School of Chemical Engineering

1976-10-01

Field-ion microscopy was used to study the faceting behavior and/or surface energy anisotropy of tungsten in vacuum and in hydrogen. In vacuum below 1700 K the activation energy for (110) facet growth agreed with values previously reported for surface diffusion on tungsten. The observed anisotropy values at 0.5 Tsub(m), where Tsub(m) is the absolute melting temperature of tungsten (approximately 3680 K), were different from those previously reported at higher temperatures and more nearly agreed with broken bond calculations based on Mie potential using m=5, n=8, and a 1.5% lattice expansion. Hydrogen appeared to have a negligible effect on surface energy anisotropy, but did preferentially increase surface diffusion rates on (310) regions.

Regulating urban surface runoff through nature-based solutions - An assessment at the micro-scale.

Science.gov (United States)

Zölch, Teresa; Henze, Lisa; Keilholz, Patrick; Pauleit, Stephan

2017-08-01

Urban development leads to changes of surface cover that disrupt the hydrological cycle in cities. In particular, impermeable surfaces and the removal of vegetation reduce the ability to intercept, store and infiltrate rainwater. Consequently, the volume of stormwater runoff and the risk of local flooding rises. This is further amplified by the anticipated effects of climate change leading to an increased frequency and intensity of heavy rain events. Hence, urban adaptation strategies are required to mitigate those impacts. A nature-based solution, more and more promoted in politics and academia, is urban green infrastructure as it contributes to the resilience of urban ecosystems by providing services to maintain or restore hydrological functions. However, this poses a challenge to urban planners in deciding upon effective adaptation measures as they often lack information on the performance of green infrastructure to moderate surface runoff. It remains unclear what type of green infrastructure (e.g. trees, green roofs), offers the highest potential to reduce discharge volumes and to what extent. Against this background, this study provides an approach to gather quantitative evidence on green infrastructure's regulation potential. We use a micro-scale scenario modelling approach of different variations of green cover under current and future climatic conditions. The scenarios are modelled with MIKE SHE, an integrated hydrological simulation tool, and applied to a high density residential area of perimeter blocks in Munich, Germany. The results reveal that both trees and green roofs increase water storage capacities and hence reduce surface runoff, although the main contribution of trees lies in increasing interception and evapotranspiration, whereas green roofs allow for more retention through water storage in their substrate. With increasing precipitation intensities as projected under climate change their regulating potential decreases due to limited water

Residential building energy conservation and avoided power plant emissions by urban and community trees in the United States

Science.gov (United States)

David J. Nowak; Nathaniel Appleton; Alexis Ellis; Eric Greenfield

2017-01-01

Urban trees and forests alter building energy use and associated emissions from power plants by shading buildings, cooling air temperatures and altering wind speeds around buildings. Field data on urban trees were combined with local urban/community tree and land cover maps, modeling of tree effects on building energy use and pollutant emissions, and state energy and...

Understanding the Impact of Urbanization on Surface Urban Heat Islands—A Longitudinal Analysis of the Oasis Effect in Subtropical Desert Cities

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Chao Fan

2017-06-01

Full Text Available We quantified the spatio-temporal patterns of land cover/land use (LCLU change to document and evaluate the daytime surface urban heat island (SUHI for five hot subtropical desert cities (Beer Sheva, Israel; Hotan, China; Jodhpur, India; Kharga, Egypt; and Las Vegas, NV, USA. Sequential Landsat images were acquired and classified into the USGS 24-category Land Use Categories using object-based image analysis with an overall accuracy of 80% to 95.5%. We estimated the land surface temperature (LST of all available Landsat data from June to August for years 1990, 2000, and 2010 and computed the urban-rural difference in the average LST and Normalized Difference Vegetation Index (NDVI for each city. Leveraging non-parametric statistical analysis, we also investigated the impacts of city size and population on the urban-rural difference in the summer daytime LST and NDVI. Urban expansion is observed for all five cities, but the urbanization pattern varies widely from city to city. A negative SUHI effect or an oasis effect exists for all the cities across all three years, and the amplitude of the oasis effect tends to increase as the urban-rural NDVI difference increases. A strong oasis effect is observed for Hotan and Kharga with evidently larger NDVI difference than the other cities. Larger cities tend to have a weaker cooling effect while a negative association is identified between NDVI difference and population. Understanding the daytime oasis effect of desert cities is vital for sustainable urban planning and the design of adaptive management, providing valuable guidelines to foster smart desert cities in an era of climate variability, uncertainty, and change.

Parametrisation of the variety of human behaviour related to building energy consumption in the Town Energy Balance (SURFEX-TEB v. 8.2

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R. Schoetter

2017-07-01

Full Text Available The anthropogenic heat flux can be an important part of the urban surface energy balance. Some of it is due to energy consumption inside buildings, which depends on building use and human behaviour, both of which are very heterogeneous in most urban areas. Urban canopy parametrisations (UCP, such as the Town Energy Balance (TEB, parametrise the effect of the buildings on the urban surface energy balance. They contain a simple building energy model. However, the variety of building use and human behaviour at grid point scale has not yet been represented in state of the art UCPs. In this study, we describe how we enhance the Town Energy Balance in order to take fractional building use and human behaviour into account. We describe how we parametrise different behaviours and initialise the model for applications in France. We evaluate the spatio-temporal variability of the simulated building energy consumption for the city of Toulouse. We show that a more detailed description of building use and human behaviour enhances the simulation results. The model developments lay the groundwork for simulations of coupled urban climate and building energy consumption which are relevant for both the urban climate and the climate change mitigation and adaptation communities.

Parametrisation of the variety of human behaviour related to building energy consumption in the Town Energy Balance (SURFEX-TEB v. 8.2)

Science.gov (United States)

Schoetter, Robert; Masson, Valéry; Bourgeois, Alexis; Pellegrino, Margot; Lévy, Jean-Pierre

2017-07-01

The anthropogenic heat flux can be an important part of the urban surface energy balance. Some of it is due to energy consumption inside buildings, which depends on building use and human behaviour, both of which are very heterogeneous in most urban areas. Urban canopy parametrisations (UCP), such as the Town Energy Balance (TEB), parametrise the effect of the buildings on the urban surface energy balance. They contain a simple building energy model. However, the variety of building use and human behaviour at grid point scale has not yet been represented in state of the art UCPs. In this study, we describe how we enhance the Town Energy Balance in order to take fractional building use and human behaviour into account. We describe how we parametrise different behaviours and initialise the model for applications in France. We evaluate the spatio-temporal variability of the simulated building energy consumption for the city of Toulouse. We show that a more detailed description of building use and human behaviour enhances the simulation results. The model developments lay the groundwork for simulations of coupled urban climate and building energy consumption which are relevant for both the urban climate and the climate change mitigation and adaptation communities.

Rapid modification of urban land surface temperature during rainfall

Science.gov (United States)

Omidvar, H.; Bou-Zeid, E.; Song, J.; Yang, J.; Arwatz, G.; Wang, Z.; Hultmark, M.; Kaloush, K.

2017-12-01

We study the runoff dynamics and heat transfer over urban pavements during rainfall. A kinematic wave approach is combined with heat storage and transfer schemes to develop a model for impervious (with runoff) and pervious (without runoff) pavements. The resulting framework is a numerical prognostic model that can simulate the temperature fields in the subsurface and runoff layers to capture the rapid cooling of the surface, as well as the thermal pollution advected in the runoff. Extensive field measurements were then conducted over experimental pavements in Arizona to probe the physics and better represent the relevant processes in the model, and then to validate the model. The experimental data and the model results were in very good agreements, and their joint analysis elucidated the physics of the rapid heat transfer from the subsurface to the runoff layer. Finally, we apply the developed model to investigate how the various hydrological and thermal properties of the pavements, as well as ambient environmental conditions, modulate the surface and runoff thermal dynamics, what is the relative importance of each of them, and how we can apply the model mitigate the adverse impacts of urbanization.

Exploring the relationship between urbanization and energy consumption in China using ARDL (autoregressive distributed lag) and FDM (factor decomposition model)

International Nuclear Information System (INIS)

Liu, Yaobin

2009-01-01

The paper develops a function of energy consumption, population growth, economic growth and urbanization process, and provides fresh empirical evidences for urbanization and energy consumption for China over the period 1978-2008 through the use of ARDL testing approach and factor decomposition model. The results of the bounds test show that there is a stable long run relationship amongst total energy consumption, population, GDP (Gross domestic product) and urbanization level when total energy consumption is the dependent variable in China. The results of the causality test with ECM (error correction model) specification, the short run and long run dynamics of the interested variables are tested, indicating that there exists only a unidirectional Granger causality running from urbanization to total energy consumption both in the long run and in the short run. At present, the contribution share which urbanization drags the energy consumption is smaller than that in the past, and the intensity holds a downward trend. Therefore, together with enhancing energy efficiency, accelerating the urbanization process that can cut reliance on resource and energy dependent industries is a fundamental strategy to solve the sustainable development dilemma between energy consumption and urbanization.

Exploring the relationship between urbanization and energy consumption in China using ARDL (autoregressive distributed lag) and FDM (factor decomposition model)

Energy Technology Data Exchange (ETDEWEB)

Liu, Yaobin [Research Center of the Central China Economic Development, Nanchang University, Nanchang 330047 (China)

2009-11-15

The paper develops a function of energy consumption, population growth, economic growth and urbanization process, and provides fresh empirical evidences for urbanization and energy consumption for China over the period 1978-2008 through the use of ARDL testing approach and factor decomposition model. The results of the bounds test show that there is a stable long run relationship amongst total energy consumption, population, GDP (Gross domestic product) and urbanization level when total energy consumption is the dependent variable in China. The results of the causality test with ECM (error correction model) specification, the short run and long run dynamics of the interested variables are tested, indicating that there exists only a unidirectional Granger causality running from urbanization to total energy consumption both in the long run and in the short run. At present, the contribution share which urbanization drags the energy consumption is smaller than that in the past, and the intensity holds a downward trend. Therefore, together with enhancing energy efficiency, accelerating the urbanization process that can cut reliance on resource and energy dependent industries is a fundamental strategy to solve the sustainable development dilemma between energy consumption and urbanization. (author)

SLC summer 2010 university - The ocean in the climate-energy problem, urban policies. Proceedings

International Nuclear Information System (INIS)

2010-09-01

This document brings together the available presentations given at the summer 2010 university of the SLC (save the climate) organization on the topics of the ocean in the climate-energy problem, and of the urban policies. Nine presentations (slides) are compiled in this document and deal with: 1 - Biofuels made from micro-algae: stakes and challenges (Olivier Bernard, Comore - INRIA /CNRS/UPMC); 2 - The energy of waves (Alain Clement, Ecole Centrale de Nantes); 3 - The sea, new source of renewable energies? (J.J. Herou, EDF CIH); 4 - Oceans acidification: the other CO 2 problem (James Orr, Pierre Simon Laplace Institute - IPSL, Laboratory of climate and environmental Sciences - LSCE, CEA-CNRS-UVSQ); 5 - Oceans and carbon cycle (Laurent Bopp, IPSL/LSCE); 6 - Renewable marine energies (Yann-Herve De Roeck, France Energies Marines); 7 - Energy renovation of buildings (Jean-Claude Terrier, Mesac Europe); 8 - Modevur research project - Modeling of urban development, sketch of a development typology of chinese cities (Clement-Noel Douady); 9 - Urban areas in the fight against climate change: stakes, knowledge and controversies (Francois Menard, PUCA)

Surface energy of metal alloy nanoparticles

Science.gov (United States)

Takrori, Fahed M.; Ayyad, Ahmed

2017-04-01

The measurement of surface energy of alloy nanoparticles experimentally is still a challenge therefore theoretical work is necessary to estimate its value. In continuation of our previous work on the calculation of the surface energy of pure metallic nanoparticles we have extended our work to calculate the surface energy of different alloy systems, namely, Co-Ni, Au-Cu, Cu-Al, Cu-Mg and Mo-Cs binary alloys. It is shown that the surface energy of metallic binary alloy decreases with decreasing particle size approaching relatively small values at small sizes. When both metals in the alloy obey the Hume-Rothery rules, the difference in the surface energy is small at the macroscopic as well as in the nano-scale. However when the alloy deviated from these rules the difference in surface energy is large in the macroscopic and in the nano scales. Interestingly when solid solution formation is not possible at the macroscopic scale according to the Hume-Rothery rules, it is shown it may form at the nano-scale. To our knowledge these findings here are presented for the first time and is challenging from fundamental as well as technological point of views.

Monitoring surface urban heat island formation in a tropical mountain city using Landsat data (1987-2015)

Science.gov (United States)

Estoque, Ronald C.; Murayama, Yuji

2017-11-01

Since it was first described about two centuries ago and due to its adverse impacts on urban ecological environment and the overall livability of cities, the urban heat island (UHI) phenomenon has been, and still is, an important research topic across various fields of study. However, UHI studies on cities in mountain regions are still lacking. This study aims to contribute to this endeavor by monitoring and examining the formation of surface UHI (SUHI) in a tropical mountain city of Southeast Asia -Baguio City, the summer capital of the Philippines- using Landsat data (1987-2015). Based on mean surface temperature difference between impervious surface (IS) and green space (GS1), SUHI intensity (SUHII) in the study area increased from 2.7 °C in 1987 to 3.4 °C in 2015. Between an urban zone (>86% impervious) and a rural zone (<10% impervious) along the urban-rural gradient, it increased from 4.0 °C in 1987 to 8.2 °C in 2015. These results are consistent with the rapid urbanization of the area over the same period, which resulted in a rapid expansion of impervious surfaces and substantial loss of green spaces. Together with landscape composition variables (e.g. fraction of IS), topographic variables (e.g. hillshade) can help explain a significant amount of spatial variations in surface temperature in the area (R2 = 0.56-0.85) (p < 0.001). The relative importance of the 'fraction of IS' variable also increased, indicating that its unique explanatory and predictive power concerning the spatial variations of surface temperature increases as the city size becomes bigger and SUHI gets more intense. Overall, these results indicate that the cool temperature of the study area being situated in a mountain region did not hinder the formation of SUHI. Thus, the formation and effects of UHIs, including possible mitigation and adaptation measures, should be considered in landscape planning for the sustainable urban development of the area.

A Specified Procedure for Distress Identification and Assessment for Urban Road Surfaces Based on PCI

Directory of Open Access Journals (Sweden)

Giuseppe Loprencipe

2017-04-01

Full Text Available In this paper, a simplified procedure for the assessment of pavement structural integrity and the level of service for urban road surfaces is presented. A sample of 109 Asphalt Concrete (AC urban pavements of an Italian road network was considered to validate the methodology. As part of this research, the most recurrent defects, those never encountered and those not defined with respect to the list collected in the ASTM D6433 have been determined by statistical analysis. The goal of this research is the improvement of the ASTM D6433 Distress Identification Catalogue to be adapted to urban road surfaces. The presented methodology includes the implementation of a Visual Basic for Application (VBA language-based program for the computerization of Pavement Condition Index (PCI calculation with interpolation by the parametric cubic spline of all of the density/deduct value curves of ASTM D6433 distress types. Also, two new distress definitions (for manholes and for tree roots and new density/deduct curve values were proposed to achieve a new distress identification manual for urban road pavements. To validate the presented methodology, for the 109 urban pavements considered, the PCI was calculated using the new distress catalogue and using the ASTM D6433 implemented on PAVERTM. The results of the linear regression between them and their statistical parameters are presented in this paper. The comparison of the results shows that the proposed method is suitable for the identification and assessment of observed distress in urban pavement surfaces at the PCI-based scale.

Global Cooling: Effect of Urban Albedo on Global Temperature

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hashem; Menon, Surabi; Rosenfeld, Arthur

2007-05-22

In many urban areas, pavements and roofs constitute over 60% of urban surfaces (roof 20-25%, pavements about 40%). The roof and the pavement albedo can be increased by about 0.25 and 0.10, respectively, resulting in a net albedo increase for urban areas of about 0.1. Many studies have demonstrated building cooling-energy savings in excess of 20% upon raising roof reflectivity from an existing 10-20% to about 60%. We estimate U.S. potential savings in excess of $1 billion (B) per year in net annual energy bills. Increasing albedo of urban surfaces can reduce the summertime urban temperature and improve the urban air quality. Increasing the urban albedo has the added benefit of reflecting more of the incoming global solar radiation and countering the effect of global warming. We estimate that increasing albedo of urban areas by 0.1 results in an increase of 3 x 10{sup -4} in Earth albedo. Using a simple global model, the change in air temperature in lowest 1.8 km of the atmosphere is estimated at 0.01K. Modelers predict a warming of about 3K in the next 60 years (0.05K/year). Change of 0.1 in urban albedo will result in 0.01K global cooling, a delay of {approx}0.2 years in global warming. This 0.2 years delay in global warming is equivalent to 10 Gt reduction in CO2 emissions.

Opportunities for Saving Energy and Improving Air Quality in Urban Heat Islands

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hashem

2007-07-01

World energy use is the main contributor to atmospheric CO2. In 2002, about 7.0 giga metric tons of carbon (GtC) were emitted internationally by combustion of gas, liquid, and solid fuels (CDIAC, 2006), 2 to 5 times the amount contributed by deforestation (Brown et al., 1988). The share of atmospheric carbon emissions for the United States from fossil fuel combustion was 1.6 GtC. Increasing use of fossil fuel and deforestation together have raised atmospheric CO{sub 2} concentration some 25% over the last 150 years. According to global climate models and preliminary measurements, these changes in the composition of the atmosphere have already begun raising the Earth's average temperature. If current energy trends continue, these changes could drastically alter the Earth's temperature, with unknown but potentially catastrophic physical and political consequences. During the last three decades, increased energy awareness has led to conservation efforts and leveling of energy consumption in the industrialized countries. An important byproduct of this reduced energy use is the lowering of CO{sub 2} emissions. Of all electricity generated in the United States, about one-sixth is used to air-condition buildings. The air-conditioning use is about 400 tera-watt-hours (TWh), equivalent to about 80 million metric tons of carbon (MtC) emissions, and translating to about $40 billion (B) per year. Of this $40 B/year, about half is used in cities that have pronounced 'heat islands'. The contribution of the urban heat island to the air-conditioning demand has increased over the last 40 years and it is currently at about 10%. Metropolitan areas in the United States (e.g., Los Angeles, Phoenix, Houston, Atlanta, and New York City) have typically pronounced heat islands that warrant special attention by anyone concerned with broad-scale energy efficiency (HIG, 2006). The ambient air is primarily heated through three processes: direct absorption of solar radiation

Surface Energy Balance in Jakarta and Neighboring Regions As Simulated Using Fifth Mesoscale Model (MM5

Directory of Open Access Journals (Sweden)

Yopi Ilhamsyah

2014-04-01

Full Text Available The objective of the present research was to assess the surface energy balance particularly in terms of the computed surface energy and radiation balance and the development of boundary layer over Jakarta and Neighboring Regions (JNR by means of numerical model of fifth generation of Mesoscale Model (MM5. The MM5 with four domains of 9 kilometers in spatial resolution presenting the outermost and the innermost of JNR is utilized. The research focuses on the third and fourth domains covering the entire JNR. The description between radiation and energy balance at the surface is obtained from the model. The result showed that energy balance is higher in the city area during daytime. Meanwhile, energy components, e.g., surface sensible and latent heat flux showed that at the sea and in the city areas were higher than other areas. Moreover, ground flux showed eastern region was higher than others. In general, radiation and energy balance was higher in the daytime and lower in the nighttime for all regions. The calculation of Bowen Ratio, the ratio of surface sensible and latent heat fluxes, was also higher in the city area, reflecting the dominations of urban and built-up land in the region. Meanwhile, Bowen Ratio in the rural area dominated by irrigated cropland was lower. It is consistent with changes of land cover properties, e.g. albedo, soil moisture, and thermal characteristics. In addition, the boundary layer is also higher in the city. Meanwhile western region dominated by suburban showed higher boundary layer instead of eastern region.

Energy demand in China: Comparison of characteristics between the US and China in rapid urbanization stage

International Nuclear Information System (INIS)

Lin, Boqiang; Ouyang, Xiaoling

2014-01-01

Highlights: • Energy demand characteristics of the US and China were compared. • Major factors affecting energy demand were examined based on the panel data and the cointegration models. • China’s energy demand would reach 5498.13 Mtce in 2020 and 6493.07 Mtce in 2030. • Urbanization can be an opportunity for low-carbon development in China. - Abstract: China’s energy demand has shown characteristics of rigid growth in the current urbanization stage. This paper applied the panel data model and the cointegration model to examine the determinants of energy demand in China, and then forecasts China’s energy demand based on the scenario analysis. Results demonstrate an inverted U-shaped relationship between energy demand and economic growth in the long term. In business as usual scenario, China’s energy consumption will reach 6493.07 million tons of coal equivalent in 2030. The conclusions can be drawn on the basis of the comparison of characteristics between the US and China. First, energy demand has rigid growth characteristics in the rapid urbanization stage. Second, coal-dominated energy structure of China will lead to the severe problems of CO 2 emissions. Third, rapid economic growth requires that energy prices should not rise substantially, so that energy conservation will be the major strategy for China’s low-carbon transition. Major policy implications are: first, urbanization can be used as an opportunity for low-carbon development; second, energy price reform is crucial for China’s energy sustainability

[Analysis of first flush effect of typical underlying surface runoff in Beijing urban city].

Science.gov (United States)

Ren, Yu-Fen; Wang, Xiao-Ke; Ouyang, Zhi-Yun; Hou, Pei-Qiang

2013-01-01

Rapid increase of the urban impervious underlying surfaces causes a great increase of urban runoff and the accumulation of pollutants on the roof and road surfaces brings many pollutants into the drainage system with the runoff, and it thus becomes a great threat to the urban water environment. To know the runoff pollution process and to build scientific basis for pollutant control, runoff processes from the roof and road surfaces were monitored and analyzed from 2004 to 2006, and the runoff EMC (Event Mean Concentration) was calculated. It was found that two types of runoff were seriously polluted by COD and TN. The COD and TN of roof runoff exceeded the fifth level of the surface water environmental quality standard (GB 3838-2002) by 3.64 and 4.80 times, respectively, and the COD and TN of road runoff exceeded by 3.73 and 1.07 times, respectively. M (V) curve was used to determine the relation between runoff volume and runoff pollution load. Various degrees of the first flush phenomenon were found for TSS, COD, TN and TP in roof runoff. But this phenomenon occurred only for TSS and TP of the road runoff, and on the whole it was not obvious. Properties of the underlying surfaces, rainfall intensity, and pollutant accumulation are all important factors affecting the roof and road runoff pollutant emission characteristics.

SURFACE SYMMETRY ENERGY OF NUCLEAR ENERGY DENSITY FUNCTIONALS

Energy Technology Data Exchange (ETDEWEB)

Nikolov, N; Schunck, N; Nazarewicz, W; Bender, M; Pei, J

2010-12-20

We study the bulk deformation properties of the Skyrme nuclear energy density functionals. Following simple arguments based on the leptodermous expansion and liquid drop model, we apply the nuclear density functional theory to assess the role of the surface symmetry energy in nuclei. To this end, we validate the commonly used functional parametrizations against the data on excitation energies of superdeformed band-heads in Hg and Pb isotopes, and fission isomers in actinide nuclei. After subtracting shell effects, the results of our self-consistent calculations are consistent with macroscopic arguments and indicate that experimental data on strongly deformed configurations in neutron-rich nuclei are essential for optimizing future nuclear energy density functionals. The resulting survey provides a useful benchmark for further theoretical improvements. Unlike in nuclei close to the stability valley, whose macroscopic deformability hangs on the balance of surface and Coulomb terms, the deformability of neutron-rich nuclei strongly depends on the surface-symmetry energy; hence, its proper determination is crucial for the stability of deformed phases of the neutron-rich matter and description of fission rates for r-process nucleosynthesis.

Integrating Surface Water Management in Urban and Regional Planning, Case Study of Wuhan in China

NARCIS (Netherlands)

Du, N.

2010-01-01

The main goal of the study is to examine and develop a spatial planning methodology that would enhance the sustainability of urban development by integrating the surface water system in the urban and regional planning process. Theoretically, this study proposes that proactive-integrated policy and

Examining Urban Impervious Surface Distribution and Its Dynamic Change in Hangzhou Metropolis

Directory of Open Access Journals (Sweden)

Longwei Li

2016-03-01

Full Text Available Analysis of urban distribution and its expansion using remote sensing data has received increasing attention in the past three decades, but little research has examined spatial patterns of urban distribution and expansion with buffer zones in different directions. This research selected Hangzhou metropolis as a case study to analyze spatial patterns and dynamic changes based on time-series urban impervious surface area (ISA datasets. ISA was developed from Landsat imagery between 1991 and 2014 using a hybrid approach consisting of linear spectral mixture analysis, decision tree classifiers, and post-processing. The spatial patterns of ISA distribution and its dynamic changes in eight directions—east, southeast, south, southwest, west, northwest, north, and northeast—at the temporal scale were analyzed with a buffer zone-based approach. This research indicated that ISA can be extracted from Landsat imagery with both producer and user accuracies of over 90%. ISA in Hangzhou metropolis increased from 146 km2 in 1991 to 868 km2 in 2014. Annual ISA growth rates were between 15.6 km2 and 48.8 km2 with the lowest growth rate in 1994–2000 and the highest growth rate in 2005–2010. Urban ISA increase before 2000 was mainly due to infilling within the urban landscape, and, after 2005, due to urban expansion in the urban-rural interfaces. Urban expansion in this study area has different characteristics in various directions that are influenced by topographic factors and urban development policies.

A research agenda for a people-centred approach to energy access in the urbanizing global south

DEFF Research Database (Denmark)

Broto, Vanesa Castán; Stevens, Lucy; Ackom, Emmanuel

2017-01-01

focused on three key issues: understanding the needs of urban energy users; enabling the use of context-specific, disaggregated data; and engaging with effective modes of energy and urban governance. This agenda requires interdisciplinary scholarship across the social and physical sciences to support...

Geospatial Technologies to Improve Urban Energy Efficiency

Directory of Open Access Journals (Sweden)

Bharanidharan Hemachandran

2011-07-01

Full Text Available The HEAT (Home Energy Assessment Technologies pilot project is a FREE Geoweb mapping service, designed to empower the urban energy efficiency movement by allowing residents to visualize the amount and location of waste heat leaving their homes and communities as easily as clicking on their house in Google Maps. HEAT incorporates Geospatial solutions for residential waste heat monitoring using Geographic Object-Based Image Analysis (GEOBIA and Canadian built Thermal Airborne Broadband Imager technology (TABI-320 to provide users with timely, in-depth, easy to use, location-specific waste-heat information; as well as opportunities to save their money and reduce their green-house-gas emissions. We first report on the HEAT Phase I pilot project which evaluates 368 residences in the Brentwood community of Calgary, Alberta, Canada, and describe the development and implementation of interactive waste heat maps, energy use models, a Hot Spot tool able to view the 6+ hottest locations on each home and a new HEAT Score for inter-city waste heat comparisons. We then describe current challenges, lessons learned and new solutions as we begin Phase II and scale from 368 to 300,000+ homes with the newly developed TABI-1800. Specifically, we introduce a new object-based mosaicing strategy, an adaptation of Emissivity Modulation to correct for emissivity differences, a new Thermal Urban Road Normalization (TURN technique to correct for scene-wide microclimatic variation. We also describe a new Carbon Score and opportunities to update city cadastral errors with automatically defined thermal house objects.

Rural-urban household energy use and inter-relation in the Central Region of the Sudan

International Nuclear Information System (INIS)

Elgizouli, I.A.R.

1990-01-01

Urban and rural household energy consumption accounts for the major part of total energy consumption in most African countries. It ranges between 50 and 70 percent in African countries with medium per capita incomes and between 58 and 93 percent in those with low per capita incomes. Satisfying household energy needs takes up a substantial portion of the income of the urban household, while in the rural areas much time and effort are spent collecting wood instead of in more productive activities. Woodfuel meets over 85 percent of household energy demand in most African countries. This high level of consumption will remain, irrespective of the country's per capita income: woodfuel will continue to play a major role in the economics of developing countries and especially in the living standards of both rural and urban poor. The two major issues which must be considered are whether the forest resources are going to meet the future demand for woodfuel and whether prices will remain affordable to the low income groups. This paper deals with household energy issues with special reference to the Central Region in the Sudan. It assesses local resources in the region, analyzes consumption patterns of both rural and urban households, and discusses possible solutions to the impact of current energy practices

Responses of herbaceous plants to urban air pollution: Effects on growth, phenology and leaf surface characteristics

International Nuclear Information System (INIS)

Honour, Sarah L.; Bell, J. Nigel B.; Ashenden, Trevor W.; Cape, J. Neil; Power, Sally A.

2009-01-01

Vehicle exhaust emissions are a dominant feature of urban environments and are widely believed to have detrimental effects on plants. The effects of diesel exhaust emissions on 12 herbaceous species were studied with respect to growth, flower development, leaf senescence and leaf surface wax characteristics. A diesel generator was used to produce concentrations of nitrogen oxides (NO x ) representative of urban conditions, in solardome chambers. Annual mean NO x concentrations ranged from 77 nl l -l to 98 nl l -1 , with NO:NO 2 ratios of 1.4-2.2, providing a good experimental simulation of polluted roadside environments. Pollutant exposure resulted in species-specific changes in growth and phenology, with a consistent trend for accelerated senescence and delayed flowering. Leaf surface characteristics were also affected; contact angle measurements indicated changes in surface wax structure following pollutant exposure. The study demonstrated clearly the potential for realistic levels of vehicle exhaust pollution to have direct adverse effects on urban vegetation. - Fumigation experiments demonstrate adverse effects of exhaust emissions on urban vegetation

Assessment of photobiological safety of energy-efficiency urban lighting

Directory of Open Access Journals (Sweden)

Łukasz Stanisław Pierzchała

2018-02-01

Full Text Available Exceeding the safe threshold for exposure on high energy radiation (UV and blue light could cause the emergence of a number of diseases. Eyesight is particularly sensitive to excessive lighting. This paper presents the laboratory research on the assessment of the photobiological risk generated by the energy-efficiency urban lighting. The results show that LED lighting systems can be a source of radiation that significantly negatively affects the eyesight and could contribute to circadian rhythm disorders.

Food-Energy Interactive Tradeoff Analysis of Sustainable Urban Plant Factory Production Systems

Directory of Open Access Journals (Sweden)

Li-Chun Huang

2018-02-01

Full Text Available This research aims to analyze the food–energy interactive nexus of sustainable urban plant factory systems. Plant factory systems grow agricultural products within artificially controlled growing environment and multi-layer vertical growing systems. The system controls the supply of light, temperature, humidity, nutrition, water, and carbon dioxide for growing plants. Plant factories are able to produce consistent and high-quality agricultural products within less production space for urban areas. The production systems use less labor, pesticide, water, and nutrition. However, food production of plant factories has many challenges including higher energy demand, energy costs, and installation costs of artificially controlled technologies. In the research, stochastic optimization model and linear complementarity models are formulated to conduct optimal and equilibrium food–energy analysis of plant factory production. A case study of plant factories in the Taiwanese market is presented.

The urban wind energy potential for integrated roof wind energy systems based on local building height distributions

NARCIS (Netherlands)

Blok, R.; Coers, M.D.

2017-01-01

An Integrated Roof Wind Energy System (IRWES) is a roof mounted structure with an internal wind turbine that uses smart aerodynamics to catch and accelerate wind flow. It has been designed for application on (existing) buildings in the urban environment. To estimate the maximum total wind energy

Discovering the energy, economic and environmental potentials of urban wastes: An input–output model for a metropolis case

International Nuclear Information System (INIS)

Song, Junnian; Yang, Wei; Li, Zhaoling; Higano, Yoshiro; Wang, Xian’en

2016-01-01

Highlights: • A waste-to-energy system is constructed incorporating various urban wastes and technologies. • Waste-to-energy industries are formed and introduced into current socioeconomic system. • A novel input–output simulation model is developed and applied to a metropolis. • Complete energy, economic and environmental potentials of urban wastes are discovered. - Abstract: Tremendous amounts of wastes are generated in urban areas due to accelerating industrialization and urbanization. The current unreasonable waste disposal patterns and potential energy value of urban wastes necessitates the promotion of waste-to-energy implementation. This study is intent on discovering the complete energy, economic and environmental potentials of urban wastes taking municipal solid wastes, waste oil, organic wastewater and livestock manure into consideration. A waste-to-energy system is constructed incorporating these wastes and five waste-to-energy technologies. A novel input–output simulation model is developed and applied to a metropolis to introduce the waste-to-energy system into the current socioeconomic system and form five waste-to-energy industries. The trends in waste generation and energy recovery potential, economic benefits and greenhouse gas mitigation contribution for the study area are estimated and explored from 2011 to 2025. By 2025, biodiesel production and power generation could amount to 72.11 thousand t and 1.59 billion kW h respectively. Due to the highest energy recovery and the most subsidies, the organic wastewater biogas industry has the highest output and net profit, followed by the waste incineration power generation industry. In total 17.97 million t (carbon dioxide-equivalent) accumulative greenhouse gas emission could be mitigated. The organic wastewater biogas industry and waste incineration power generation industry are more advantageous for the study area in terms of better energy, economic and environmental performances. The

Conceptualizing urban household energy use: Climbing the 'Energy Services Ladder'

International Nuclear Information System (INIS)

Sovacool, Benjamin K.

2011-01-01

This article begins by defining energy services and identifying how they differ according to sector, urban and rural areas, and direct and indirect uses. It then investigates household energy services divided into three classes: lower income, middle income, and upper income. It finds that the primary energy technologies involved with low-income households involve a greater number of fuels and carriers, ranging from dung and fuelwood to liquefied petroleum gas and charcoal, but a fewer number of services. Middle-income households throughout the world tend to rely on electricity and natural gas, followed by coal, liquefied petroleum gas, and kerosene. These homes utilize energy to produce a much broader range services. The upper class or rich have access to the same energy fuels, carriers, and technologies as middle-income homes and families, but consume more energy (and more high luxury items). The study highlights how focusing on energy services reorients the direction of energy policy interventions, that energy services are neither uniform nor innate, and by noting exciting areas of potential research. - Research highlights: → The primary energy technologies involved with low-income households involve a greater number of fuels and carriers, ranging from dung and fuelwood to liquefied petroleum gas and charcoal, but a fewer number of services. → Middle-income households throughout the world tend to rely on electricity and natural gas, followed by coal, liquefied petroleum gas, and kerosene. These homes utilize energy to produce a much broader range services. → The upper class or rich have access to the same energy fuels, carriers, and technologies as middle-income homes and families, but consume more energy (and more high luxury items).

Analysis of surface contributions to external doses in a radioactively contaminated urban environment designed by the EMRAS-2 Urban Areas Working Group

International Nuclear Information System (INIS)

Hwang, Won Tae; Jeong, Hae Sun; Jeong, Hyo Joon; Kim, Eun Han; Han, Moon Hee; Kim, In Gyu

2013-01-01

Highlights: ► External dose and contribution from radio-activated surface were evaluated for EMRAS-2 Urban Areas Working Group scenarios. ► The external doses showed a distinctive difference with the locations and precipitation. ► The contribution of contaminated surfaces for external dose depends on locations and precipitation. ► These results provide the essential information for decision-making support of countermeasures. - Abstract: The EMRAS-2 Urban Areas Working Group, which is supported by the IAEA, has designed a variety of accidental scenarios to test and improve the capabilities of the models used for an evaluation of radioactive contamination in an urban environment. A variety of models including a Korean model, METRO-K, are used for predictive results on the hypothetical scenarios. This paper describes the predictive results of METRO-K for the hypothetical scenarios designed in the Working Group. The external dose resulting from the air contamination of Co-60 was evaluated, and its contribution was analyzed with time as a function of the location of a receptor and precipitation conditions at the time of the contamination event. As a result, the external doses showed a distinctive difference with the locations to be evaluated and the precipitation conditions. Moreover, the contribution of contaminated surfaces for external doses was strongly dependent on the locations to be evaluated and the precipitation conditions. These results will provide essential information to assist the decision-making of appropriate countermeasures in an emergency situation of a radioactively contaminated urban environment

Urban Physics: Effect of the micro-climate on comfort, health and energy demand

OpenAIRE

Moonen, Peter; Defraeye, Thijs; Dorer, Viktor; Blocken, Bert; Carmeliet, Jan

2012-01-01

The global trend towards urbanisation explains the growing interest in the study of the modification of the urban climate due to the heat island effect and global warming, and its impact on energy use of buildings. Also urban comfort, health and durability, referring respectively to pedestrian wind/thermal comfort, pollutant dispersion and wind-driven rain are of interest. Urban Physics is a well-established discipline, incorporating relevant branches of physics, environmental chemistry, aero...

Assessment of two loss methods for estimation of surface runoff in Zaafrania urban catchment, North-East of Algeria

OpenAIRE

Dahdouh Yacina; Ouerdachi Lahbassi

2018-01-01

Surface runoff is a major problem in urban catchments; its generation is always related to the amount of effective rainfall dropped over the surface, however in urban catchments the process is considerably altered by the emergence of impervious areas. In this study the Soil Consevation Service – curve number (SCS-CN) and the Green–Ampt loss methods were used in rainfall-runoff modelling in the Zaafrania urban catchment which is located in Annaba city in the north east of Algeria. The two loss...

Effects of Urbanization and Seasonal Cycle on the Surface Urban Heat Island Patterns in the Coastal Growing Cities: A Case Study of Casablanca, Morocco

Directory of Open Access Journals (Sweden)

Hicham Bahi

2016-10-01

Full Text Available The urban heat island (UHI phenomenon is a harmful environmental problem in urban areas affecting both climatic and ecological processes. This paper aims to highlight and monitor the spatial distribution of Surface UHI (SUHI in the Casablanca region, Morocco, using remote sensing data. To achieve this goal, a time series of Landsat TM/ETM+/OLI-TIRS images was acquired from 1984 to 2016 and analyzed. In addition, nocturnal MODIS images acquired from 2005 to 2015 were used to evaluate the nighttime SUHI. In order to better analyze intense heat produced by urban core, SUHI intensity (SUHII was computed by quantifying the difference of land surface temperature (LST between urban and rural areas. The urban core SUHII appears more significant in winter seasons than during summer, while the pattern of SUHII becomes moderate during intermediate seasons. During winter, the average daytime SUHII gradually increased in the residential area of Casablanca and in some small peri-urban cities by more than 1 °C from 1984 to 2015. The industrial areas of the Casablanca region were affected by a significant rise in SUHII exceeding 15 °C in certain industrial localities. In contrast, daytime SUHII shows a reciprocal effect during summer with emergence of a heat island in rural areas and development of cool islands in urban and peri-urban areas. During nighttime, the SUHII remains positive in urban areas year-round with higher values in winter as compared to summer. The results point out that the seasonal cycle of daytime SUHII as observed in the Casablanca region is different from other mid-latitude cities, where the highest values are often observed in summer during the day.

Using Cool Roofs to Reduce Energy Use, Greenhouse Gas Emissions, and Urban Heat-island Effects: Findings from an India Experiment

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hashem; Xu, Tengfang; Taha, Haider; Wray, Craig; Sathaye, Jayant; Garg, Vishal; Tetali, Surekha; Babu, M. Hari; Reddy, K. Niranjan

2011-05-25

energy in India. Meteorological simulations in this study indicated that a reduction of 2C in air temperature in the Hyderabad area would be likely if a combination of increased surface albedo and vegetative cover are used as urban heat-island control strategies. In addition, air-temperature reductions on the order of 2.5-3.5C could be achieved if moderate and aggressive heat-island mitigation measures are adopted, respectively. A large-scale deployment of mitigation measures can bring additional indirect benefit to the urban area. For example, cooling outside air can improve the efficiency of cooling systems, reduce smog and greenhouse gas (GHG) emissions, and indirectly reduce pollution from power plants - all improving environmental health quality. This study has demonstrated the effectiveness of cool-roof technology as one of the urban heat-island control strategies for the Indian industrial and scientific communities and has provided an estimate of the national energy savings potential of cool roofs in India. These outcomes can be used for developing cool-roof building standards and related policies in India. Additional field studies, built upon the successes and lessons learned from this project, may be helpful to further confirm the scale of potential energy savings from the application of cooler roofs in various regions of India. In the future, a more rigorous meteorological simulation using urbanized (meso-urban) meteorological models should be conducted, which may produce a more accurate estimate of the air-temperature reductions for the entire urban area.

Innovative approach for achieving of sustainable urban water supply system by using of solar photovoltaic energy

Directory of Open Access Journals (Sweden)

Jure Margeta

2017-01-01

Full Text Available Paper describes and analyses new and innovative concept for possible integration of solar photovoltaic (PV energy in urban water supply system (UWSS. Proposed system consists of PV generator and invertor, pump station and water reservoir. System is sized in such a manner that every his part is sized separately and after this integrated into a whole. This integration is desirable for several reasons, where the most important is the achievement of the objectives of sustainable living in urban areas i.e. achieving of sustainable urban water supply system. The biggest technological challenge associated with the use of solar, wind and other intermittent renewable energy sources RES is the realization of economically and environmentally friendly electric energy storage (EES. The paper elaborates the use of water reservoires in UWSS as EES. The proposed solution is still more expensive than the traditional and is economically acceptable today in the cases of isolated urban water system and special situations. Wider application will depend on the future trends of energy prices, construction costs of PV generators and needs for CO2 reduction by urban water infrastructure.

A new scheme for urban impervious surface classification from SAR images

Science.gov (United States)

Zhang, Hongsheng; Lin, Hui; Wang, Yunpeng

2018-05-01

Urban impervious surfaces have been recognized as a significant indicator for various environmental and socio-economic studies. There is an increasingly urgent demand for timely and accurate monitoring of the impervious surfaces with satellite technology from local to global scales. In the past decades, optical remote sensing has been widely employed for this task with various techniques. However, there are still a range of challenges, e.g. handling cloud contamination on optical data. Therefore, the Synthetic Aperture Radar (SAR) was introduced for the challenging task because it is uniquely all-time- and all-weather-capable. Nevertheless, with an increasing number of SAR data applied, the methodology used for impervious surfaces classification remains unchanged from the methods used for optical datasets. This shortcoming has prevented the community from fully exploring the potential of using SAR data for impervious surfaces classification. We proposed a new scheme that is comparable to the well-known and fundamental Vegetation-Impervious surface-Soil (V-I-S) model for mapping urban impervious surfaces. Three scenes of fully polarimetric Radsarsat-2 data for the cities of Shenzhen, Hong Kong and Macau were employed to test and validate the proposed methodology. Experimental results indicated that the overall accuracy and Kappa coefficient were 96.00% and 0.8808 in Shenzhen, 93.87% and 0.8307 in Hong Kong and 97.48% and 0.9354 in Macau, indicating the applicability and great potential of the new scheme for impervious surfaces classification using polarimetric SAR data. Comparison with the traditional scheme indicated that this new scheme was able to improve the overall accuracy by up to 4.6% and Kappa coefficient by up to 0.18.

EVALUATION OF URBANIZATION INFLUENCES ON URBAN ...

African Journals Online (AJOL)

Osondu

2012-07-27

Jul 27, 2012 ... climate over the cities that affect human comfort and his environment. Proper urban ... Key Words: Urbanization, Comfort, Pollution, Modification, Albedo, Urban Heat Island ... effects of land surface change on the climate of a.

Modelling and observing urban climate in the Netherlands

International Nuclear Information System (INIS)

Van Hove, B.; Steeneveld, G.J.; Heusinkveld, B.; Holtslag, B.; Jacobs, C.; Ter Maat, H.; Elbers, J.; Moors, E.

2011-06-01

The main aims of the present study are: (1) to evaluate the performance of two well-known mesoscale NWP (numerical weather prediction) models coupled to a UCM (Urban Canopy Models), and (2) to develop a proper measurement strategy for obtaining meteorological data that can be used in model evaluation studies. We choose the mesoscale models WRF (Weather Research and Forecasting Model) and RAMS (Regional Atmospheric Modeling System), respectively, because the partners in the present project have a large expertise with respect to these models. In addition WRF and RAMS have been successfully used in the meteorology and climate research communities for various purposes, including weather prediction and land-atmosphere interaction research. Recently, state-of-the-art UCM's were embedded within the land surface scheme of the respective models, in order to better represent the exchange of heat, momentum, and water vapour in the urban environment. Key questions addressed here are: What is the general model performance with respect to the urban environment?; How can useful and observational data be obtained that allow sensible validation and further parameterization of the models?; and Can the models be easily modified to simulate the urban climate under Dutch climatic conditions, urban configuration and morphology? Chapter 2 reviews the available Urban Canopy Models; we discuss their theoretical basis, the different representations of the urban environment, the required input and the output. Much of the information was obtained from the Urban Surface Energy Balance: Land Surface Scheme Comparison project (PILPS URBAN, PILPS stands for Project for Inter-comparison of Land-Surface Parameterization Schemes). This project started in March 2008 and was coordinated by the Department of Geography, King's College London. In order to test the performance of our models we participated in this project. Chapter 3 discusses the main results of the first phase of PILPS URBAN. A first

Surface temperatures in New York City: Geospatial data enables the accurate prediction of radiative heat transfer.

Science.gov (United States)

Ghandehari, Masoud; Emig, Thorsten; Aghamohamadnia, Milad

2018-02-02

Despite decades of research seeking to derive the urban energy budget, the dynamics of thermal exchange in the densely constructed environment is not yet well understood. Using New York City as a study site, we present a novel hybrid experimental-computational approach for a better understanding of the radiative heat transfer in complex urban environments. The aim of this work is to contribute to the calculation of the urban energy budget, particularly the stored energy. We will focus our attention on surface thermal radiation. Improved understanding of urban thermodynamics incorporating the interaction of various bodies, particularly in high rise cities, will have implications on energy conservation at the building scale, and for human health and comfort at the urban scale. The platform presented is based on longwave hyperspectral imaging of nearly 100 blocks of Manhattan, in addition to a geospatial radiosity model that describes the collective radiative heat exchange between multiple buildings. Despite assumptions in surface emissivity and thermal conductivity of buildings walls, the close comparison of temperatures derived from measurements and computations is promising. Results imply that the presented geospatial thermodynamic model of urban structures can enable accurate and high resolution analysis of instantaneous urban surface temperatures.

A Comparative study on the Role of Energy Efficiency in Urban Planning Instruments of Iran and Germany

Directory of Open Access Journals (Sweden)

Mahta Mirmoghtadaee

2015-12-01

Full Text Available In recent years energy efficiency in different levels become of prime importance. Studies have been shown that urban planning can play a critical role in this area. At the same time in oil-producing countries like Iran, energy efficiency has not been considered as a national priority. However, in recent years with increase in the population growth, rapid urbanization and acceleration of environmental degradation, the issue is gaining more importance. Iran has adopted its first national building code on energy efficiency in 90’s. However, as the country lacks a hierarchical energy planning system, its achievements were below the expectations. To improve the situation, it is important to study the experiences of other countries. Germany with a solid and successful energy planning in different scales can be considered as one of the pioneering countries, and its programs could be used as a guideline to achieve similar goals in other countries. Recently the German government has adopted a highly ambitious energy program, called “Energy transition” (Energiewende. The program will affect all planning instruments and ordinances in the country. As a comprehensive and upper level plan, "Energy transition" can be studied form different viewpoints. In the current study, its influence on urban planning instruments will be the main focus. The main objective is to compare the role of energy in urban planning instruments of Iran and Germany, and to develop some solutions and strategies to be considered in Iran. The first step in this study is the introduction of urban planning systems and instruments in the two countries, then the role of energy in each country will be introduced and with an analytical review, some suggestion for Iranian planning instruments will be made. Using comparative study as the research methodology, the study will focus on "comprehensive plan" and "detailed plan" as two main urban planning instruments in Iran, and "binding land

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

Science.gov (United States)

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.

Impact of energy subsidies on energy consumption and supply in Zimbabwe. Do the urban poor really benefit?

International Nuclear Information System (INIS)

Dube, Ikhupuleng

2003-01-01

Twenty percent of Zimbabwe's urban poor households are still to be connected to the grid. The majority of these households are poor. There are several reasons why the Zimbabwe urban poor are still not connected to the grid, the most important one being the household incomes and the cost of different sources of energy. In order to facilitate wider usage of electricity by the poor, the policy makers have introduced a subsidy policy. The objective of this paper is to ascertain the extent to which the poor urban households could afford the cost of electricity with or without subsidies. This gives an indication on whether contrary to the current thinking, subsidies are decisive for the affordability of electricity by the urban households. The paper also examines the distribution of the subsidies, amongst the different urban household income categories and other economic sectors. Furthermore the impact of such subsidies on the utility's finances is assessed

Build-up dynamics of heavy metals deposited on impermeable urban surfaces.

Science.gov (United States)

Wicke, D; Cochrane, T A; O'Sullivan, A

2012-12-30

A method using thin boards (3 cm thick, 0.56 m(2)) comprising different paving materials typically used in urban environments (2 asphalt types and concrete) was employed to specifically investigate air-borne deposition dynamics of TSS, zinc, copper and lead. Boards were exposed at an urban car park near vehicular traffic to determine the rate of contaminant build-up over a 13-day dry period. Concentration profiles from simulated rainfall wash-off were used to determine contaminant yields at different antecedent dry days. Maximum contaminant yields after 13 days of exposure were 2.7 kg ha(-1) for TSS, 35 g ha(-1) zinc, 2.3 g ha(-1) copper and 0.4 g ha(-1) lead. Accumulation of all contaminants increased over the first week and levelled off thereafter, supporting theoretical assumptions that contaminant accumulation on impervious surfaces asymptotically approaches a maximum. Comparison of different surface types showed approximately four times higher zinc concentrations in runoff from asphalt surfaces and two times higher TSS concentrations in runoff from concrete, which is attributed to different physical and chemical compositions of the pavement types. Contaminant build-up and wash-off behaviours were modelled using exponential and saturation functions commonly applied in the US EPA's Stormwater Management Model (SWMM) showing good correlation between measured and modelled concentrations. Maximum build-up, half-saturation time, build-up rate constants and wash-off coefficients, necessary for stormwater contaminant modelling, were determined for the four contaminants studied. These parameters are required to model contaminant concentrations in urban runoff assisting in stormwater management decisions. Copyright © 2012 Elsevier Ltd. All rights reserved.

From Problems to Potentials : The Urban Energy Transition of Gruž, Dubrovnik

NARCIS (Netherlands)

van den Dobbelsteen, A.A.J.F.; Martin, C.L.; Keeffe, Greg; Pulselli, Riccardo; Vandevyvere, Han

2018-01-01

IIn the challenge for a sustainable society, carbon-neutrality is a critical objective for all cities in the coming decades. In the EU City-zen project, academic partners collaborate to develop an urban energy transition methodology, which supports cities in making the energy transition to

Optimal Intra-Urban Hierarchy of Activity Centers—A Minimized Household Travel Energy Consumption Approach

Directory of Open Access Journals (Sweden)

Jie Zhang

2015-08-01

Full Text Available An intra-urban hierarchy of activity centers interconnected by non-motorized and public transportation is broadly believed to be the ideal urban spatial structure for sustainable cities. However, the proper hinterland area for centers at each level lacks empirical study. Based on the concentric structure of everyday travel distances, working centers, shopping centers, and neighborhood centers are extracted from corresponding types of POIs in 286 Chinese cities at the prefectural level and above. A U-shaped curve between Household Transportation Energy Consumption (HTEC per capita and center density at each of the three levels has been found through regression analysis. An optimal intra-urban hierarchy of activity centers is suggested to construct energy-efficient cities.

Modeling urban storm rainfall runoff from diverse underlying surfaces and application for control design in Beijing.

Science.gov (United States)

Ouyang, Wei; Guo, Bobo; Hao, Fanghua; Huang, Haobo; Li, Junqi; Gong, Yongwei

2012-12-30

Managing storm rainfall runoff is paramount in semi-arid regions with urban development. In Beijing, pollution prevention in urban storm runoff and storm water utilization has been identified as the primary strategy for urban water management. In this paper, we sampled runoff during storm rainfall events and analyzed the concentration of chemical oxygen demand (COD), total suspended solids (TSS) and total phosphorus (TP) in the runoff. Furthermore, the first flush effect of storm rainfall from diverse underlying surfaces was also analyzed. With the Storm Water Management Model (SWMM), the different impervious rates of underlying surfaces during the storm runoff process were expressed. The removal rates of three typical pollutants and their interactions with precipitation and underlying surfaces were identified. From these rates, the scenarios regarding the urban storm runoff pollution loading from different designs of underlying previous rates were assessed with the SWMM. First flush effect analysis showed that the first 20% of the storm runoff should be discarded, which can help in utilizing the storm water resource. The results of this study suggest that the SWMM can express in detail the storm water pollution patterns from diverse underlying surfaces in Beijing, which significantly affected water quality. The scenario analysis demonstrated that impervious rate adjustment has the potential to reduce runoff peak and decrease pollution loading. Copyright © 2012 Elsevier Ltd. All rights reserved.

Household energy use in urban Venezuela: Implications from surveys in Maracaibo, Valencia, Merida, and Barcelona-Puerto La Cruz

Energy Technology Data Exchange (ETDEWEB)

Figueroa, M.J.; Sathaye, J.

1993-08-01

This report identifies the most important results of a comparative analysis of household commercial energy use in Venezuelan urban cities. The use of modern fuels is widespread among all cities. Cooking consumes the largest share of urban household energy use. The survey documents no use of biomass and a negligible use of kerosene for cooking. LPG, natural gas, and kerosene are the main fuels available. LPG is the fuel choice of low-income households in all cities except Maracaibo, where 40% of all households use natural gas. Electricity consumption in Venezuela`s urban households is remarkably high compared with the levels used in households in comparable Latin American countries and in households of industrialized nations which confront harsher climatic conditions and, therefore, use electricity for water and space heating. The penetration of appliances in Venezuela`s urban households is very high. The appliances available on the market are inefficient, and there are inefficient patterns of energy use among the population. Climate conditions and the urban built form all play important roles in determining the high level of energy consumption in Venezuelan urban households. It is important to acknowledge the opportunities for introducing energy efficiency and conservation in Venezuela`s residential sector, particularly given current economic and financial constraints, which may hamper the future provision of energy services.

Validation of Martilli's urban boundary layer scheme with measurements from two mid-latitude European cities

Science.gov (United States)

Hamdi, R.; Schayes, G.

2007-08-01

Martilli's urban parameterization scheme is improved and implemented in a mesoscale model in order to take into account the typical effects of a real city on the air temperature near the ground and on the surface exchange fluxes. The mesoscale model is run on a single column using atmospheric data and radiation recorded above roof level as forcing. Here, the authors validate Martilli's urban boundary layer scheme using measurements from two mid-latitude European cities: Basel, Switzerland and Marseilles, France. For Basel, the model performance is evaluated with observations of canyon temperature, surface radiation, and energy balance fluxes obtained during the Basel urban boundary layer experiment (BUBBLE). The results show that the urban parameterization scheme represents correctly most of the behavior of the fluxes typical of the city center of Basel, including the large heat uptake by the urban fabric and the positive sensible heat flux at night. For Marseilles, the model performance is evaluated with observations of surface temperature, canyon temperature, surface radiation, and energy balance fluxes collected during the field experiments to constrain models of atmospheric pollution and transport of emissions (ESCOMPTE) and its urban boundary layer (UBL) campaign. At both urban sites, vegetation cover is less than 20%, therefore, particular attention was directed to the ability of Martilli's urban boundary layer scheme to reproduce the observations for the Marseilles city center, where the urban parameters and the synoptic forcing are totally different from Basel. Evaluation of the model with wall, road, and roof surface temperatures gave good results. The model correctly simulates the net radiation, canyon temperature, and the partitioning between the turbulent and storage heat fluxes.

Paradigm shift in urban energy systems through distributed generation: Methods and models

International Nuclear Information System (INIS)

Manfren, Massimiliano; Caputo, Paola; Costa, Gaia

2011-01-01

The path towards energy sustainability is commonly referred to the incremental adoption of available technologies, practices and policies that may help to decrease the environmental impact of energy sector, while providing an adequate standard of energy services. The evaluation of trade-offs among technologies, practices and policies for the mitigation of environmental problems related to energy resources depletion requires a deep knowledge of the local and global effects of the proposed solutions. While attempting to calculate such effects for a large complex system like a city, an advanced multidisciplinary approach is needed to overcome difficulties in modeling correctly real phenomena while maintaining computational transparency, reliability, interoperability and efficiency across different levels of analysis. Further, a methodology that rationally integrates different computational models and techniques is necessary to enable collaborative research in the field of optimization of energy efficiency strategies and integration of renewable energy systems in urban areas. For these reasons, a selection of currently available models for distributed generation planning and design is presented and analyzed in the perspective of gathering their capabilities in an optimization framework to support a paradigm shift in urban energy systems. This framework embodies the main concepts of a local energy management system and adopts a multicriteria perspective to determine optimal solutions for providing energy services through distributed generation.

Occurrence, distribution and seasonal variation of organophosphate flame retardants and plasticizers in urban surface water in Beijing, China

International Nuclear Information System (INIS)

Shi, Yali; Gao, Lihong; Li, Wenhui; Wang, Yuan; Liu, Jiemin; Cai, Yaqi

2016-01-01

The occurrence, spatial distribution and seasonal variation of 14 organophosphate esters (OPEs) were investigated in urban surface water (river and lake water) from July 2013 to June 2014 in Beijing, China. Sewage influent and effluent samples, as well as rainwater and road runoff samples were also analyzed as the potential sources of OPEs in surface water. Tris(2-chloro-1-methylethyl) phosphate (TCPP) and tris(2-chloroethyl) phosphate (TCEP) were the most abundant OPEs with the average concentrations of 291 ng L"−"1 and 219 ng L"−"1, respectively. Relatively high concentrations of OPEs were detected in rivers located at southern and eastern urban of Beijing, which was probably attributed to the treated and untreated sewage discharge. Besides, higher levels of OPEs were observed in urban surface water in the summer, and the wet deposition (rainfall) was confirmed to be an important factor for this observation. Risk assessment showed low or medium risk of OPEs for the organisms (algae, crustacean and fish). - Highlights: • High levels of OPEs were detected in urban surface water of Beijing, China. • Seasonal variation revealed higher levels of OPEs in the summer. • Wastewater, rainwater and road runoff samples were analyzed as sources of OPEs. • The risks of OPEs to the organisms (algae, crustacean and fish) were assessed. - The occurrence, spatial distribution and seasonal variation of OPEs in urban surface water were investigated from densely populated big city (Beijing, China).

A model for radiological dose assessment in an urban environment

International Nuclear Information System (INIS)

Hwang, Won Tae; Kim, Eun Han; Jeong, Hyo Joon; Suh, Kyung Suk; Han, Moon Hee

2007-01-01

A model for radiological dose assessment in an urban environment, METRO-K has been developed. Characteristics of the model are as follows ; 1) mathematical structures are simple (i.e. simplified input parameters) and easy to understand due to get the results by analytical methods using experimental and empirical data, 2) complex urban environment can easily be made up using only 5 types of basic surfaces, 3) various remediation measures can be applied to different surfaces by evaluating the exposure doses contributing from each contamination surface. Exposure doses contributing from each contamination surface at a particular location of a receptor were evaluated using the data library of kerma values as a function of gamma energy and contamination surface. A kerma data library was prepared for 7 representative types of Korean urban building by extending those data given for 4 representative types of European urban buildings. Initial input data are daily radionuclide concentration in air and precipitation, and fraction of chemical type. Final outputs are absorbed dose rate in air contributing from the basic surfaces as a function of time following a radionuclide deposition, and exposure dose rate contributing from various surfaces constituting the urban environment at a particular location of a receptor. As the result of a contaminative scenario for an apartment built-up area, exposure dose rates show a distinct difference for surrounding environment as well as locations of a receptor

A climate responsive urban design tool: a platform to improve energy efficiency in a dry hot climate

Science.gov (United States)

El Dallal, Norhan; Visser, Florentine

2017-09-01

In the Middle East and North Africa (MENA) region, new urban developments should address the climatic conditions to improve outdoor comfort and to reduce the energy consumption of buildings. This article describes a design tool that supports climate responsive design for a dry hot climate. The approach takes the climate as an initiator for the conceptual urban form with a more energy-efficient urban morphology. The methodology relates the different passive strategies suitable for major climate conditions in MENA region (dry-hot) to design parameters that create the urban form. This parametric design approach is the basis for a tool that generates conceptual climate responsive urban forms so as to assist the urban designer early in the design process. Various conceptual scenarios, generated by a computational model, are the results of the proposed platform. A practical application of the approach is conducted on a New Urban Community in Aswan (Egypt), showing the economic feasibility of the resulting urban form and morphology, and the proposed tool.

Analysis of surface air temperature variations and local urbanization effects on central Yunnan Plateau, SW China

Science.gov (United States)

He, Yunling; Wu, Zhijie; Liu, Xuelian; Deng, Fuying

2018-01-01

With the surface air temperature (SAT) data at 37 stations on Central Yunnan Plateau (CYP) for 1961-2010 and the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime light data, the temporal-spatial patterns of the SAT trends are detected using Sen's Nonparametric Estimator of Slope approach and MK test, and the impact of urbanization on surface warming is analyzed by comparing the differences between the air temperature change trends of urban stations and their corresponding rural stations. Results indicated that annual mean air temperature showed a significant warming trend, which is equivalent to a rate of 0.17 °C/decade during the past 50 years. Seasonal mean air temperature presents a rising trend, and the trend was more significant in winter (0.31 °C/decade) than in other seasons. Annual/seasonal mean air temperature tends to increase in most areas, and higher warming trend appeared in urban areas, notably in Kunming city. The regional mean air temperature series was significantly impacted by urban warming, and the urbanization-induced warming contributed to approximately 32.3-62.9 % of the total regional warming during the past 50 years. Meantime, the urbanization-induced warming trend in winter and spring was more significant than that in summer and autumn. Since 1985, the urban heat island (UHI) intensity has gradually increased. And the urban temperatures always rise faster than rural temperatures on the CYP.

Analysis of energy flow during playground surface impacts.

Science.gov (United States)

Davidson, Peter L; Wilson, Suzanne J; Chalmers, David J; Wilson, Barry D; Eager, David; McIntosh, Andrew S

2013-10-01

The amount of energy dissipated away from or returned to a child falling onto a surface will influence fracture risk but is not considered in current standards for playground impact-attenuating surfaces. A two-mass rheological computer simulation was used to model energy flow within the wrist and surface during hand impact with playground surfaces, and the potential of this approach to provide insights into such impacts and predict injury risk examined. Acceleration data collected on-site from typical playground surfaces and previously obtained data from children performing an exercise involving freefalling with a fully extended arm provided input. The model identified differences in energy flow properties between playground surfaces and two potentially harmful surface characteristics: more energy was absorbed by (work done on) the wrist during both impact and rebound on rubber surfaces than on bark, and rubber surfaces started to rebound (return energy to the wrist) while the upper limb was still moving downward. Energy flow analysis thus provides information on playground surface characteristics and the impact process, and has the potential to identify fracture risks, inform the development of safer impact-attenuating surfaces, and contribute to development of new energy-based arm fracture injury criteria and tests for use in conjunction with current methods.

Energy assessment of peri-urban horticulture and its uncertainty: Case study for Bogota, Colombia

Energy Technology Data Exchange (ETDEWEB)

Bojaca, C.R. [Centro de Investigaciones y Asesorias Agroindustriales, Facultad de Ciencias Naturales, Universidad de Bogota Jorge Tadeo Lozano, P.O. Box: 140196, Chia (Colombia); Schrevens, E. [Department of Biosystems, Faculty of Applied Bioscience Engineering, Katholieke Universiteit Leuven, Geo-Institute, Celestijnenlaan 200 E, 3001 Heverlee (Belgium)

2010-05-15

Scarce information is available about the energy use pattern of horticultural commodities in general and more specifically for peri-urban horticulture. Peri-urban horticulture in the outskirts of Bogota is an important source of vegetables for Colombia's capital city. Based on detailed follow-ups and periodic field measurements an output-input energy balance was performed with the main objective to study the energy use efficiency of those systems. An uncertainty analysis on the input factors and on the energy equivalents was then applied. Over a measurement period of 18-month, the energy use for coriander, lettuce, radish and spinach was investigated, respectively 12.1, 18.8, 6.6 and 10.7 GJ ha{sup -1} were consumed in these cropping systems. Negative balances were observed for all species exception made for spinach where an output:input ratio of 1.16 was found. The two-way uncertainty analysis showed the highest uncertainty for N-based fertilization while no significant effect was observed for seeds in direct sowing crops. Sustainability of peri-urban horticulture around Bogota is compromised not only because of the city expansion but also due to its inefficient energy use. Technical improvements are required to ensure the environmental subsistence of this important sector for the metropolitan area of the city. (author)

A Surface Temperature Initiated Closure (STIC) for surface energy balance fluxes

DEFF Research Database (Denmark)

Mallick, Kaniska; Jarvis, Andrew J.; Boegh, Eva

2014-01-01

The use of Penman–Monteith (PM) equation in thermal remote sensing based surface energy balance modeling is not prevalent due to the unavailability of any direct method to integrate thermal data into the PM equation and due to the lack of physical models expressing the surface (or stomatal......) and boundary layer conductances (gS and gB) as a function of surface temperature. Here we demonstrate a new method that physically integrates the radiometric surface temperature (TS) into the PM equation for estimating the terrestrial surface energy balance fluxes (sensible heat, H and latent heat, λ......E). The method combines satellite TS data with standard energy balance closure models in order to derive a hybrid closure that does not require the specification of surface to atmosphere conductance terms. We call this the Surface Temperature Initiated Closure (STIC), which is formed by the simultaneous solution...

Multiple sources of boron in urban surface waters and groundwaters

Energy Technology Data Exchange (ETDEWEB)

Hasenmueller, Elizabeth A., E-mail: eahasenm@wustl.edu; Criss, Robert E.

2013-03-01

Previous studies attribute abnormal boron (B) levels in streams and groundwaters to wastewater and fertilizer inputs. This study shows that municipal drinking water used for lawn irrigation contributes substantial non-point loads of B and other chemicals (S-species, Li, and Cu) to surface waters and shallow groundwaters in the St. Louis, Missouri, area. Background levels and potential B sources were characterized by analysis of lawn and street runoff, streams, rivers, springs, local rainfall, wastewater influent and effluent, and fertilizers. Urban surface waters and groundwaters are highly enriched in B (to 250 μg/L) compared to background levels found in rain and pristine, carbonate-hosted streams and springs (< 25 μg/L), but have similar concentrations (150 to 259 μg/L) compared to municipal drinking waters derived from the Missouri River. Other data including B/SO{sub 4}{sup 2-}−S and B/Li ratios confirm major contributions from this source. Moreover, sequential samples of runoff collected during storms show that B concentrations decrease with increased discharge, proving that elevated B levels are not primarily derived from combined sewer overflows (CSOs) during flooding. Instead, non-point source B exhibits complex behavior depending on land use. In urban settings B is rapidly mobilized from lawns during “first flush” events, likely representing surficial salt residues from drinking water used to irrigate lawns, and is also associated with the baseflow fraction, likely derived from the shallow groundwater reservoir that over time accumulates B from drinking water that percolates into the subsurface. The opposite occurs in small rural watersheds, where B is leached from soils by recent rainfall and covaries with the event water fraction. Highlights: ► Boron sources and loads differ between urban and rural watersheds. ► Wastewaters are not the major boron source in small St. Louis, MO watersheds. ► Municipal drinking water used for lawn

Food-Energy Interactive Tradeoff Analysis of Sustainable Urban Plant Factory Production Systems

OpenAIRE

Li-Chun Huang; Yu-Hui Chen; Ya-Hui Chen; Chi-Fang Wang; Ming-Che Hu

2018-01-01

This research aims to analyze the food–energy interactive nexus of sustainable urban plant factory systems. Plant factory systems grow agricultural products within artificially controlled growing environment and multi-layer vertical growing systems. The system controls the supply of light, temperature, humidity, nutrition, water, and carbon dioxide for growing plants. Plant factories are able to produce consistent and high-quality agricultural products within less production space for urban a...

Effectiveness of Different Urban Heat Island Mitigation Methods and Their Regional Impacts

Science.gov (United States)

Zhang, N.

2017-12-01

Cool roofs and green roofs are two popular methods to mitigate urban heat island and improve urban climate. The effectiveness of different urban heat island mitigation strategies in the summer of 2013 in the Yangtze River Delta, China is investigated using the WRF (Weather Research and Forecasting) model coupled with a physically based urban canopy model. The modifications to the roof surface changed the urban surface radiation balance and then modified the local surface energy budget. Both cool roofs and green roofs led to lower surface skin temperature and near-surface air temperature. Increasing the roof albedo to 0.5 caused a similar effectiveness as covering 25% of urban roofs with vegetation; increasing roof albedo to 0.7 caused a similar near-surface air temperature decrease as 75% green roof coverage. The near-surface relative humidity increased in both cool roof and green roof experiments because of the combination of the impacts of increases in specific humidity and decreases in air temperature. The regional impacts of cool roofs and green roofs were evaluated using the regional effect index. The regional effect could be found in both near-surface air temperature and surface specific/relative humidity when the percentage of roofs covered with high albedo materials or green roofs reached a higher fraction (greater than 50%). The changes in the vertical profiles of temperature cause a more stable atmospheric boundary layer over the urban area; at the same time, the crossover phenomena occurred above the boundary layer due to the decrease in vertical wind speed.

Multilayer Relaxation and Surface Energies of Metallic Surfaces

Science.gov (United States)

Bozzolo, Guillermo; Rodriguez, Agustin M.; Ferrante, John

1994-01-01

The perpendicular and parallel multilayer relaxations of fcc (210) surfaces are studied using equivalent crystal theory (ECT). A comparison with experimental and theoretical results is made for AI(210). The effect of uncertainties in the input parameters on the magnitudes and ordering of surface relaxations for this semiempirical method is estimated. A new measure of surface roughness is proposed. Predictions for the multilayer relaxations and surface energies of the (210) face of Cu and Ni are also included.

Urban sustainable energy development: A case study of the city of Philadelphia

Science.gov (United States)

Argyriou, Iraklis

This study explores the role of cities in sustainable energy development through a governance-informed analysis. Despite the leading position of municipalities in energy sustainability, cities have been mostly conceptualized as sites where energy development is shaped by external policy scales, i.e. the national level. A growing body of research, however, critiques this analytical perspective, and seeks to better understand the type of factors and dynamics that influence energy sustainability within a multi-level policy context for urban energy. Given that particular circumstances are applicable across cities, a context-specific analysis can provide insight regarding how sustainable energy development takes place in urban areas. In applying such an analytical perspective on urban energy sustainability, this study undertakes a qualitative case study analysis for the city of Philadelphia, Pennsylvania, by looking at four key local policy initiatives relevant to building energy efficiency and solar electricity development at the municipal government and city-wide level. The evaluation of the initiatives suggests that renewable electricity use has increased substantially in the city over the last years but the installed capacity of local renewable electricity systems, including solar photovoltaics, is low. On the other hand, although the city has made little progress in meeting its building energy efficiency targets, more comprehensive action is taken in this area. The study finds that the above outcomes have been shaped mainly by four factors. The first is the city government's incremental policy approach aiming to develop a facilitative context for local action. The second is the role that a diverse set of stakeholders have in local sustainable energy development. The third is the constraints that systemic policy barriers create for solar power development. The fourth is the ways through which the relevant multi-level policy environment structures the city

Validation of the Martilli's Urban Boundary Layer Scheme with measurements from two mid-latitude European cities

Science.gov (United States)

Hamdi, R.; Schayes, G.

2005-07-01

The Martilli's urban parameterization scheme is improved and implemented in a mesoscale model in order to take into account the typical effects of a real city on the air temperature near the ground and on the surface exchange fluxes. The mesoscale model is run on a single column using atmospheric data and radiation recorded above roof level as forcing. Here, the authors validate the Martilli's urban boundary layer scheme using measurements from two mid-latitude European cities: Basel, Switzerland and Marseilles, France. For Basel, the model performance is evaluated with observations of canyon temperature, surface radiation, and energy balance fluxes obtained during the Basel urban boundary layer experiment (BUBBLE). The results show that the urban parameterization scheme is able to reproduce the generation of the Urban Heat Island (UHI) effect over urban area and represents correctly most of the behavior of the fluxes typical of the city center of Basel, including the large heat uptake by the urban fabric and the positive sensible heat flux at night. For Marseilles, the model performance is evaluated with observations of surface temperature, canyon temperature, surface radiation, and energy balance fluxes collected during the field experiments to constrain models of atmospheric pollution and transport of emissions (ESCOMPTE) and its urban boundary layer (UBL) campaign. At both urban sites, vegetation cover is less than 20%, therefore, particular attention was directed to the ability of the Martilli's urban boundary layer scheme to reproduce the observations for the Marseilles city center, where the urban parameters and the synoptic forcing are totally different from Basel. Evaluation of the model with wall, road, and roof surface temperatures gave good results. The model correctly simulates the net radiation, canyon temperature, and the partitioning between the turbulent and storage heat fluxes.

estimation of land surface temperature of kaduna metropolis, nigeria

African Journals Online (AJOL)

Zaharaddeen et. al

Land surface temperature can provide noteworthy information about the surface ... modelling the surface energy balance (Kalma, et al., 2008; ... Landsat, in addition some of the Landsat data have cloud cover and ..... The Impact Of Urban.

Urban Form Energy Use and Emissions in China: Preliminary Findings and Model Proof of Concept

Energy Technology Data Exchange (ETDEWEB)

Aden, Nathaniel; Qin, Yining; Fridley, David

2010-12-15

Urbanization is reshaping China's economy, society, and energy system. Between 1990 and 2008 China added more than 300 million new urban residents, bringing the total urbanization rate to 46%. The ongoing population shift is spurring energy demand for new construction, as well as additional residential use with the replacement of rural biomass by urban commercial energy services. This project developed a modeling tool to quantify the full energy consequences of a particular form of urban residential development in order to identify energy- and carbon-efficient modes of neighborhood-level development and help mitigate resource and environmental implications of swelling cities. LBNL developed an integrated modeling tool that combines process-based lifecycle assessment with agent-based building operational energy use, personal transport, and consumption modeling. The lifecycle assessment approach was used to quantify energy and carbon emissions embodied in building materials production, construction, maintenance, and demolition. To provide more comprehensive analysis, LBNL developed an agent-based model as described below. The model was applied to LuJing, a residential development in Jinan, Shandong Province, to provide a case study and model proof of concept. This study produced results data that are unique by virtue of their scale, scope and type. Whereas most existing literature focuses on building-, city-, or national-level analysis, this study covers multi-building neighborhood-scale development. Likewise, while most existing studies focus exclusively on building operational energy use, this study also includes embodied energy related to personal consumption and buildings. Within the boundaries of this analysis, food is the single largest category of the building energy footprint, accounting for 23% of the total. On a policy level, the LCA approach can be useful for quantifying the energy and environmental benefits of longer average building lifespans. In

Mode selection of China's urban heating and its potential for reducing energy consumption and CO2 emission

International Nuclear Information System (INIS)

Chen, Xia; Wang, Li; Tong, Lige; Sun, Shufeng; Yue, Xianfang; Yin, Shaowu; Zheng, Lifang

2014-01-01

China's carbon dioxide (CO 2 ) emission ranks the highest in the world. CO 2 emission from urban central heating, which has an average annual growth rate of 10.3%, is responsible for 4.4% of China's total CO 2 emission. The current policy for improving urban central heating focuses on replacing coal with natural gas. This paper analyzes the existing situation and problems pertaining to urban heating, and evaluates the potential for reducing energy consumption and CO 2 emission by heat pump heating. The results show that the current policy of replacing coal with natural gas for urban central heating decreases energy consumption and CO 2 emission by 16.6% and 63.5%, respectively. On the other hand, replacing coal-based urban central heating with heat pump heating is capable of decreasing energy consumption and CO 2 emission by 57.6% and 81.4%, respectively. Replacing both urban central and decentralized heating with heat pump heating can lead to 67.7% and 85.8% reduction in energy consumption and CO 2 emission, respectively. The decreases in CO 2 emission will account for 24.5% of China's target to reduce total CO 2 emission by 2020. - Highlights: • Existing situation and problems of urban heating in China. • Feasibility of heat pump heating in China. • Potential of energy saving and emission reduction for heat pump heating. • China should adjust urban heating strategy. • Replacing urban central heating and decentralized heating with heat pump heating

Analysis of Global Urban Temperature Trends and Urbanization Impacts

Science.gov (United States)

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

2018-04-01

Due to urbanization, urban areas are shrinking green spaces and increasing concrete, asphalt pavement. So urban climates are different from non-urban areas. In addition, long-term macroscopic studies of urban climate change are becoming more important as global urbanization affects global warming. To do this, it is necessary to analyze the effect of urbanization on the temporal change in urban temperature with the same temperature data and standards for urban areas around the world. In this study, time series analysis was performed with the maximum, minimum, mean and standard values of surface temperature during the from 1980 to 2010 and analyzed the effect of urbanization through linear regression analysis with variables (population, night light, NDVI, urban area). As a result, the minimum value of the surface temperature of the urban area reflects an increase by a rate of 0.28K decade-1 over the past 31 years, the maximum value reflects an increase by a rate of 0.372K decade-1, the mean value reflects an increase by a rate of 0.208 decade-1, and the standard deviation reflects a decrease by rate of 0.023K decade-1. And the change of surface temperature in urban areas is affected by urbanization related to land cover such as decrease of greenery and increase of pavement area, but socioeconomic variables are less influential than NDVI in this study. This study are expected to provide an approach to future research and policy-planning for urban temperature change and urbanization impacts.

The socioeconomic impact of energy saving renovation measures in urban buildings

OpenAIRE

Mikulić, Davor; Rašić Bakarić, Ivana; Slijepčević, Sunčana

2016-01-01

The purpose of the paper is to investigate the role of measures oriented to energy savings in residential buildings in the economic development at the regional level. The aim of the paper is to estimate overall socio-economic impact of energy saving renovation measures in the Croatian urban areas. Impact assessment is based on input–output methodology which is able to quantify direct and indirect effects of investment in the energy saving projects on the economic activity and employment...