Tsuyoshi Setoguchi

Efficiencies of Infill Developments against Snow Problem in Winter Cities

Abstract It is important to clarify how to apply urban design principles to protect areas within winter climates. Therefore, a question is addressed that do the blocks after infill developments provide desirable environment against snow, or not. The purpose of this paper is to answer this question and clear to understand the desirable block images for reducing snow problems (snowdrifts and snow blow) on its surrounding public spaces on infill developments in Winter Cities. Author studied the differences of the snow problems between ″before″ and ″after″ the infill developments consisted of medium-rise buildings in Downtown Sapporo on snow simulation tests using wind tunnel. On this snow simulation tests, snow problems in the blocks and streets were improved after the infill developments. One of the main reasons of the observations is considered that the little variation of the building heights reduces snow problems on the public spaces in the blocks. For making the desirable spatial images in Winter Cities, the blocks have to be consisted of medium-rise buildings and unified the heights of buildings. The infill developments with medium-rise buildings with unifying building heights are effective against snow problems in downtown area, and making the desirable special block design for Winter Cities.

Development of Urban Design Guidelines with Wind Tunnel Simulations for Downtown Districts in Winter Cities

Abstract Urban design principles in many Chinese cities are similar to each other without considering regional climate variation. Especially in winter cities, without climate responsive urban design principles, most public open spaces are turned into useless places in winter, which is not only because of the low temperature, but is also due to strong wind influenced by the design of surrounding buildings. Therefore, by using wind tunnel simulation, this paper presents one scientific approach to developing original urban design guidelines for cities in cold regions. Taking typical blocks in downtown Shenyang, China as a case study, a series of high-rise buildings with various concepts of podium design are tested in a wind tunnel. According to the results of experiments, the authors concluded several urban design principles concerning regional climate for open space design and streetscape design in downtown Shenyang.

New City Block Design Approaches Incorporating Environmental Assessment for Downtown Districts in Cities with Severe Winter Climates

Urban design approaches in many Japanese cities are based on principles that are similar throughout the country without considering the variety in regional climates. Especially in cities with severe winter weather, providing desirable environments for public spaces under conditions of snow and strong winds is an important issue in urban design. This paper proposes new approaches to urban design with environmental assessments using snow and wind simulations to enable the development of original urban design concepts to improve the quality of public space. Using city blocks in downtown Sapporo, Japan as a case study, a design process flow is established together with conceptual models of city block design, assessing each of the steps of the process. The results of the assessment are then reflected back to the models and re-evaluated with an environmental assessment. With the results, the authors identify a number of principles of city block design for downtown Sapporo.

New Urban Design Approaches with Snow Simulations for Cold and Snowy Cities

abstract An urban design which reduces snow problems is one of the most important approaches in heavy snow and cold climate cities. In this paper, the author evaluated the urban design for the new Wakkanai Station redevelopment project in Hokkaido, Japan. Wakkanai City is the northernmost city of Japan, and is located in a strong snowstorm area. Two types of station design, the Trapezoid type and the Curved-surface type were tested in snow simulations using a wind tunnel that belongs to the Hokkaido Northern Regional Building Research Institute. Comparing the two types of Wakkanai Station redevelopment design, the Curved-surface design is better suited to alleviate the negative impact of snowdrifts on the pedestrian pathway. The formation of snowdrifts in the public areas will be less likely to occur due to obstructions, and there will be better access for passenger transfer and better approach for public transportation and private vehicles. But some provision for the shelter of pedestrians from strong wind should be included in the redevelopment plan. The results of this simulation will be reflected in the station redevelopment planning and design of this project. This urban design study with snow simulations might provide the most progressive approach.

Human Behavior in Downtown Public Spaces during Cooling Periods in Winter Cities

There is an urban design problem that outdoor public spaces are not used for long periods of time within a year due to coldness and snow cover in cities with severe winter climates (winter cities). Therefore, an urban design that promotes activities in these spaces is required for winter cities. The purpose of this paper is to clarify the relationship between outdoor environmental conditions and the behaviors of people in outdoor public spaces. This six-month study conducted a field survey in six kinds of public spaces in downtown Sapporo and analyzed the changes of microclimates and sitting behaviors in these spaces. The analysis revealed that sitting behaviors decreased with temperature drops during the cooling period (20 °C-8 °C), that sunlight could suppress the reduction in the number of sitting behaviors, and that wind speed could suppress the reduction in the duration of sitting behaviors.

Optimization Design of Open Spaces Based on Wind Tunnel and CFD Simulation: Case Study of a Street Canyon in Northern China

Airflow in open spaces can significantly affect spatial quality. Therefore, according to the type of building structures, the airflow also has different forms. Studies have been conducted on the relation between airflow and pedestrian comfort; however, only few of them have focused on comprehensive urban planning that considers different weather conditions and people’s ability to adapt. This research focuses on the differences in wind conditions caused by different spatial forms in different seasons. On the basis of a field survey in both summer and winter in a public open space, evaluation standards developed from environmental meteorological data and public feedback were used to evaluate simulation results. Next, several assumptions about canyon orientation and building types were proposed. Wind tunnel and CFD (computational fluid dynamics) simulations were conducted to evaluate the assumptions. The results showed that the canyon orientation significantly affected overall wind conditions and different building structures affected airflow. This research also provides a method to evaluate urban areas that have complicated wind environments.

Public Square Design with Snow and Wind Simulations Using Wind Tunnel

1.1 The purpose of the research A Snow is one of the most influence points to urban design for snow and cold region. In cities that are located in heavy snowfall and cold regions like Hokkaido, it is important to clarify how to apply urban design principles to protect areas with a harsh winter climate. Specifically, significant issues should be addressed concerning the environmental impact of snow and wind on public spaces of the urban renewal projects. In addition, desirable urban designs providing better environments in public spaces that protect against snow and wind in winter should be developed. The need has been felt for original approaches to urban design in such cities. An urban design which reduces snow problems (e.g. snowdrifts or blowing snow) is one method promoting “symbioses” between humans, snow and cold climate in those cities. In this paper, the author targeted the redevelopment project of the new Wakkanai Station Square, in Hokkaido Japan. The actual project was started in 2003 and produced by City of Wakkanai, as part of the Urban Revitalization Program in Japanese Local Cities. This author and Wakkanai City started the co-research project for a desirable design for Wakkanai Station Square with consideration given to the local climate in winter. In Wakkanai City northernmost city of Japan, the Wakkanai Station and Station Square redevelopment project have been launched. For the Square desirable space design preventing from snow and strong wind is required on the public square. In this paper, the author targeted the redevelopment project of the new Wakkanai Station Square, in Hokkaido Japan. Author focused on a Covered-Walk (CW) design for the square for protecting passengers and pedestrians against snow and wind *1. Two types of CW design were tested in a snow simulation, a leeward side CW type and a windward side CW type. The snow simulation tests were carried out using the wind tunnel in the Hokkaido Northern Regional Building Research Institute. The results of this simulation will be reflected in the square planning and design of this project.