Design Of Urban Systems Research Articles

A Clustered, Decentralized Approach to Urban Water Management

Current models in design of urban water management systems and their corresponding infrastructure using centralized designs have commonly failed from the perspective of cost effectiveness and inability to adapt to the future changes. These challenges are driving cities towards using decentralized systems. While there is great consensus on the benefits of decentralization; currently no methods exist which guide decision-makers to define the optimal boundaries of decentralized water systems. A new clustering methodology and tool to decentralize water supply systems (WSS) into small and adaptable units is presented. The tool includes two major components: (i) minimization of the distance from source to consumer by assigning demand to the closest water source, and (ii) maximization of the intra-cluster homogeneity by defining the cluster boundaries such that the variation in population density, land use, socio-economic level, and topography within the cluster is minimized. The methodology and tool were applied to Arua Town in Uganda. Four random cluster scenarios and a centralized system were created and compared with the optimal clustered WSS. It was observed that the operational cost of the four cluster scenarios is up to 13.9 % higher than the optimal, and the centralized system is 26.6% higher than the optimal clustered WSS, consequently verifying the efficacy of the proposed method to determine an optimal cluster boundary for WSS. In addition, optimal homogeneous clusters improve efficiency by encouraging reuse of wastewater and stormwater within a cluster and by minimizing leakage through reduced pressure variations.

A building clustering approach for urban energy simulations

Within the context of amongst others urban energy planning and energy system design, urban and district energy simulations have gained interest to quantify the energy use of existing districts. To reduce calculation time and in absence of adequate detailed building level data, urban energy simulations often deploy reductive modelling approaches based on a limited set of buildings, or archetype buildings. This may lead to significant modelling errors when the archetype buildings are not tailored to the studied location. This paper explores a building clustering approach that harvests available local building information, e.g. geospatial data, to generate a tailored set of archetype buildings. Focussed on simulating the annual heat demand or peak heat demand, this paper evaluates if clustering on building properties can be an alternative to clustering on the energy key performance indicators of interest to define the tailored archetypes. As consumption data on a building level is often not available, such an approach would eliminate the need to simulate the energy use for all buildings. The results show that indeed clustering on the properties is a viable alternative with robust results for both annual energy use and peak energy demand and a comparable accuracy compared to clustering on the targeted performance indicators.

Urban Systems Design: A Conceptual Framework for Planning Smart Communities

Urban systems design arises from disparate current planning approaches (urban design, Planning Support Systems, and community engagement), compounded by the reemergence of rational planning methods from new technology (Internet of Things (IoT), metric based analysis, and big data). The proposed methods join social considerations (Human Well-Being), environmental needs (Sustainability), climate change and disaster mitigation (Resilience), and prosperity (Economics) as the four foundational pillars. Urban systems design integrates planning methodologies to systematically tackle urban challenges, using IoT and rational methods, while human beings form the core of all analysis and objectives. Our approach utilizes an iterative three-phase development loop to contextualize, evaluate, plan and design scenarios for the specific needs of communities. An equal emphasis is placed on feedback loops through analysis and design, to achieve the end goal of building smart communities.

A novel decision support tool for climate-responsive urban design

With the increase of temperature, a tropical country like Singapore will face the challenge of mitigating the anthropogenic heat emissions and urban heat storage to maintain its quality of urban life. However, due to the complex nature of climate and urban fabric, it is difficult for urban planners to make climate-sensitive informed decisions on how to achieve better Outdoor Thermal Comfort (OTC) in an intuitive while holistic way. We develop a holistic and principled decision process via an implementation of a decision support tool which interactively visualizes how climatic factors, urban design scenarios, importance of spatial use, and various acceptability criteria impact the OTC assessment in a simple step-by-step manner. The advantage of this tool is that it serves as an agent-based climate-responsive urban design system that presupposes planner’s trust. A complete working example is provided which demonstrates how a user could choose the optimal scenario for a new public housing estate located at the northeast of Singapore.

A Framework for the Sustainability Assessment of (Micro)transit Systems

The increasing global focus on sustainability is bringing the question of the sustainability of transport systems—which are still exhibiting numerous negative effects as evidence of their unsustainability—to the fore. While sustainability is an often-discussed concept, tools to guide the practical implementation thereof are limited. This paper presents a framework for an inventory of indicators against which to measure the sustainability of transport systems. While the framework is validated for urban transport systems for increased mobility (here referenced as microtransit systems), the concept is investigated in the context of transport systems in general. A systematic review of the literature was used to develop a framework of 12 areas and 50 indicators of sustainability. Expert reviews, an Analytical Hierarchical Process (AHP), and an Equally Weighted Average (EWA) method were employed to allocate weights to the indicators and to validate the framework for microtransit systems. The framework contributes to the literature by identifying, categorizing, and integrating concepts related to sustainability in transport systems. It is intended to aid short-term decision-making in the design of urban transport systems, to continuously monitor the long-term progress of transport systems against sustainability goals, and to guide policy development. Future work would include enhanced empirical validation of the framework in the context of other types of transport systems, beyond microtransit.

Urban Systems Design Case Study: Tokyo's Sumida Ward

Meeting the needs of increasing environmental and systematic pressures in urban settlements requires the use of integrated and wholistic approaches. The Urban Systems Design (USD) Conceptual Framework joins the metric-based modeling of rationalized methods with human-driven goals to form a combined iterative design and analysis loop. The framework processes information for the fundamental element of cities—humans—to large-scale modeling and decision-making occurring in district- and ward-level planning. There is a need in the planning and design profession to better integrate these efforts at a greater scale to create smart communities that are inclusive and comprehensive in aspects from data management to energy and transportation networks. The purpose of this study is to examine the applicability of this method as it pertains to a model and design integrated approach. Northern Sumida Ward, located in Tokyo, exemplifies the contextualized needs of Tokyo, and Japan, while forming a coherent internal community. Focusing on methodology, our process explores the creation of typologies, metric-based analysis, and design-based approaches that are integrated into modeling. The results of the analyses provide initial evidence regarding the validity of the USD approach in modeling changes to complex systems at differing design scales, connecting various qualities of the built environment, building and urban forms, and diagnostic comparisons between baseline and change conditions. Because of some inconsistencies and the need for further evidence gathering, the methods and processes show that there is much work to be done to strengthen the model and to continue building a more productive field of USD. However, in this framework’s continuing evolution, there is increasing evidence that combining the planning and design of urban systems creates a more resilient, economically viable, sustainable, and comfortable city.

Optimal Alignments for Designing Urban Transport Systems: Application to Seville

The achievement of some of the Sustainable Development Goals (SDGs) from the recent 2030 Agenda for Sustainable Development has drawn the attention of many countries towards urban transport networks. Mathematical modeling constitutes an analytical tool for the formal description of a transportation system whereby it facilitates the introduction of variables and the definition of objectives to be optimized. One of the stages of the methodology followed in the design of urban transit systems starts with the determination of corridors to optimize the population covered by the system whilst taking into account the mobility patterns of potential users and the time saved when the public network is used instead of private means of transport. Since the capture of users occurs at stations, it seems reasonable to consider an extensive and homogeneous set of candidate sites evaluated according to the parameters considered (such as pedestrian population captured and destination preferences) and to select subsets of stations so that alignments can take place. The application of optimization procedures that decide the sequence of nodes composing the alignment can produce zigzagging corridors, which are less appropriate for the design of a single line. The main aim of this work is to include a new criterion to avoid the zigzag effect when the alignment is about to be determined. For this purpose, a curvature concept for polygonal lines is introduced, and its performance is analyzed when criteria of maximizing coverage and minimizing curvature are combined in the same design algorithm. The results show the application of the mathematical model presented for a real case in the city of Seville in Spain.

Urban Systems Design: From “science for design” to “design in science”

Urban Systems Design: From “science for design” to “design in science”

Hybrid green-blue-gray decentralized urban drainage systems design, a simulation-optimization framework

Recent studies suggested hybrid green-blue-gray infrastructures (HGBGI) as the most promising urban drainage systems that can simultaneously combine reliability, resilience, and acceptability of gray infrastructures (networks of pipes) with multi-functionality, sustainability, and adaptability of green-blue infrastructures (GBI). Combining GBI and gray measures for designing new urban drainage systems forms a nonlinear multimodal mixed integer-real optimization problem that is highly constrained and intractable. For this purpose, this study presents a simulation-optimization framework to optimize urban drainage systems considering HGBGI alternatives and different degrees of centralization. The proposed framework begins with the characterization of the site under design and drawing the base graph. Then, different layouts with different degrees of centralization are generated and hydraulically designed using a recent algorithm called hanging gardens algorithm. After introducing the feasible GBI to the model, we now perform second optimization to find the optimum distribution of GBIs in a way that minimizes total life cycle costs of GBIs and pipe networks. Finally, resiliency and sustainability of different scenarios are evaluated using several design storms that provide material for final assessment and decision-making. The performance of the proposed framework is evaluated using a real large-scale case study, a part of the city of Ahvaz in Iran. Finally, results are presented and discussed with recommendations for future studies.

Designing and modeling innovation across scales for urban water systems

Effective, sustainable management of urban water systems, including drinking water, stormwater, wastewater, and natural water systems, is critical to the health and well-being of people in urban areas and the ecosystems that encompass them. The demands of human population growth, aging infrastructure, and changing climate will increase pressure on these systems and require future innovations in water management. Planning for urban water systems will increasingly require collaborations between water professionals and researchers to imagine, design and model the response of novel urban water systems to future conditions. We highlight benefits and challenges of transdisciplinary projects for integrated urban water management; organized broadly into: (1) engagement of water managers and planners; (2) transdisciplinary design of innovative systems, and once designed; (3) modeling and evaluation of urban water system response to various innovations. We describe the development of a multi-scale approach to design and evaluation of innovative urban water systems, and illustrate its application using examples from the Willamette River Basin and Portland, Oregon. The scenario-based approach described here offers several key contributions to the design and modeling of innovation. First, this process provides the opportunity to convene professionals and researchers, who do not typically collaborate, as participants in a collaborative process. Second, it engages participants in thinking together across land and water management sectors to develop plausible futures at multiple spatial extents and multidecadal time horizons. Third, it helps to identify critical gaps in extant water modeling capabilities, and thus helps define the near-term research agenda for modelers.

Conceptual Design of Urban E-Bus Systems with Special Focus on Battery Technology

AbstractMany cities have announced ambitious plans to introduce zero-emission electric bus systems. The transformation process to electric bus systems opens up a vast design space as different charging strategies, charging technologies and battery types are available. Therefore, a profound assessment strategy is necessary to find a “most suitable system solution” under given strategic and operational requirements.In this study, we present a new methodology for conceptual design of urban electric bus systems. First, the available e-bus technologies are analysed with a special focus on charging systems, battery technology and aging. Relational functional analysis is used to derive a suitable simulation model. Based on the operational requirements, an energetic simulation of the e-bus is carried out, and the required battery capacity is obtained. Subsequently, the design space is reduced by applying a qualitative cost- technology compatibility matrix taking cost and battery aging into account. The applicability of the model is shown for an exemplary realistic operational scenario to identify three most expedient concepts, which are finally validated with an in-depth analysis.

台北市城市设计制度构建经验与启示

台北市城市设计制度构建经验与启示

Simulating Marginal and Dependence Behaviour of Water Demand Processes at Any Fine Time Scale

Uncertainty-aware design and management of urban water systems lies on the generation of synthetic series that should precisely reproduce the distributional and dependence properties of residential water demand process (i.e., significant deviation from Gaussianity, intermittent behaviour, high spatial and temporal variability and a variety of dependence structures) at various temporal and spatial scales of operational interest. This is of high importance since these properties govern the dynamics of the overall system, while prominent simulation methods, such as pulse-based schemes, address partially this issue by preserving part of the marginal behaviour of the process (e.g., low-order statistics) or neglecting the significant aspect of temporal dependence. In this work, we present a single stochastic modelling strategy, applicable at any fine time scale to explicitly preserve both the distributional and dependence properties of the process. The strategy builds upon the Nataf’s joint distribution model and particularly on the quantile mapping of an auxiliary Gaussian process, generated by a suitable linear stochastic model, to establish processes with the target marginal distribution and correlation structure. The three real-world case studies examined, reveal the efficiency (suitability) of the simulation strategy in terms of reproducing the variety of marginal and dependence properties encountered in water demand records from 1-min up to 1-h.

Decision tree (DT), generalized regression neural network (GR) and multivariate adaptive regression splines (MARS) models for sediment transport in sewer pipes.

Sediment deposition in sewers and urban drainage systems has great effect on the hydraulic capacity of the channel. In this respect, the self-cleansing concept has been widely used for sewers and urban drainage systems design. This study investigates the bed load sediment transport in sewer pipes with particular reference to the non-deposition condition in clean bed channels. Four data sets available in the literature covering wide ranges of pipe size, sediment size and sediment volumetric concentration have been utilized through applying decision tree (DT), generalized regression neural network (GR) and multivariate adaptive regression splines (MARS) techniques for modeling. The developed models have been compared with conventional regression models available in the literature. The model performance indicators, showed that DT, GR and MARS models outperform conventional regression models. Result shows that GR and MARS models are comparable in terms of calculating particle Froude number and performing better than DT. It is concluded that conventional regression models generally overestimate particle Froude number for the non-deposition condition of sediment transport, while DT, GR and MARS outputs are close to their measured counterparts.

The Sustainability System Design for Urban Planning

In Taiwan, rapidly increasing urban population has outstripped the ability of urban public infrastructure, regional resources and the surrounding environment to support it. This has led to social problems such as overcrowding, congestion, energy shortages, excessive building density, lack of green space, excessive waste volume, environmental population and crime. These have had a negative impact not only within cities but upon their surrounding areas as well. Consequently, this study proceeds to explore the main urban design factors that affect sustainability of urban development concerning Taiwan cities. Through the evaluation decision-making system model and expert groups giving evaluation values and feedback, the study found twenty- eight items of key influencing factors with eight major objectives, and propose strategies for sustainable development in the future to improve the quality and quantity of urban design and cities competitiveness. This research, in addition to providing references to relevant urban sustainability system design for deployment and R&D, also provides developing and underdeveloped countries access to urban sustainable development assessment and forecasts for the future.

Study on the layout method of Urban underground parking system-a case of underground parking system in the Central business District in linping New City of Hangzhou

In the face of imbalance between supply and demand of parking facilities in urban central business district (CBD) areas and the increasingly prominent parking problems, it has become necessary to develop and construct underground parking systems so as to alleviate ground traffic pressure and reduce traffic congestion. Underground parking system planning includes the following main components: system level division, parking scale determination, entrance and exit settings, and internal flow organization of the system. By analyzing the current parking characteristics of the CBD in Linping New City of Hangzhou, and based on indicators such as base conditions of the underground parking system, the total number of parking berths and the number of parking units, a scoring standard is used to determine a grading method for the underground parking system. According to different levels of underground parking system, and based on the number of system parking units and the number of vehicles entering and leaving the system during peak hours, the principle of setting the number of entrances and exits of underground parking system is clearly defined. According to the layout pattern of underground parking system and the internal traffic flow analysis of the vehicles entering and leaving the system, the setting of underground vehicle lanes and underground parking units in the system is taken into account to determine the internal traffic organization of underground parking system. This research provides a reference for the planning and design of urban underground parking systems.

Power quality and losses in 0.38 kV rural distribution networks

The guidelines for the design of rural and urban power supply systems do not consider the issues of reactive power compensation and reduction in additional losses due to unbalanced and non-sinusoidal conditions. At the same time, today’s rural power consumers have a great number of non-linear loads in their residential premises. Moreover, the unbalanced phase currents and voltages are an established fact. The paper aims to demonstrate the extent to which power quality and losses vary in real rural 0.38 kV networks. To this end, the objectives were posed to study the operation of two facilities: 1- switchgear at the cottage (with an installed capacity of 15 kW); 2- switchgear at the communal entrance hallway for 60 apartments in an apartment building (with an installed capacity of 75 kW).

Urban transportation system design and feasibility analysis: a case study of Lagos Mega-City

This paper examines how urban transportation, urban mobility and urban land Planning at urban Centres influence urban space that serves a variety of human needs; housing, working, social interaction, leisure, and mobility of persons and goods. Transportation and planning are co-dependent, mutually influencing each other in complex and dynamic ways. To create a livable urban environment, there is a need to balance transportation with planning. The skewers of any of these will result in serious environment issues. To identify the role and impact of road transportation in a mega city, the research methodology adopted in this work utilized environmental management system techniques. Key impacts on local community includes exchange of energy, function and maintenance of ordered structures, directly or indirectly supplied and maintained by natural system. Various socio-economic activities and professional judgment from the findings shows that spatial distribution of housing, working, shopping, leisure and other activities determines aver-age trip distances in urban mobility. High population density as well as a mixture of land use for various social and economic activities, maintains low distances between origin and destination of urban trips. It also shows that road development parameters were well within the range of metropolis city, the low density urban development and large road areas increases trip length and lead to higher share of automobile trips. The study recommends that the state government should engaged in traffic management by adjusting the use of existing road system to improve traffic operation with-out resorting to major new constructions, provision of time-based traffic lights, and enforcement of traffic lights and signs, manning of road junctions by traffic wardens, constructing overhead bridges and zebra crossings, encouragement of park and ride system and educating drivers and ensure compulsory written test before the issuance of any driving license. This can be embarked through a technology- supported joint venture that aims to integrate and systematically optimize the State’s intermodal transportation system.

Urban Data Integration Using Proximity Relationship Learning for Design, Management, and Operations of Sustainable Urban Systems

AbstractThe world is rapidly urbanizing, with 66% of the world’s population expected to reside in cities by 2050. This massive influx of new urban citizens is putting enormous pressure on city syst...

Design and operation of urban wastewater systems considering reliability, risk and resilience

Reliability, risk and resilience are strongly related concepts and have been widely utilised in the context of water infrastructure performance analysis. However, there are many ways in which each measure can be formulated (depending on the reliability of what, risk to what from what, and resilience of what to what) and the relationships will differ depending on the formulations used. This research has developed a framework to explore the ways in which reliability, risk and resilience may be formulated, identifying possible components and knowledge required for calculation of each and formalising the conceptual relationships between specified and general resilience. This utilises the Safe & SuRe framework, which shows how threats to a water system can result in consequences for society, the economy and the environment, to enable the formulations to be derived in a logical manner and to ensure consistency in any comparisons. The framework is used to investigate the relationship between levels of reliability, risk and resilience provided by multiple operational control and design strategies for an urban wastewater system case study. The results highlight that, although reliability, risk and resilience values may exhibit correlations, designing for just one is insufficient: reliability, risk and resilience are complementary rather than interchangeable measures and one cannot be used as a substitute for another. Furthermore, it is shown that commonly used formulations address only a small fraction of the possibilities and a more comprehensive assessment of a system's response to threats is necessary to provide a comprehensive understanding of risk and resilience.