The Development to New Urban Design Approaches with the Wind Tunnel Snow Simulation for Northern Regions

减少积雪问题的城市设计是大雪和寒冷气候城市最重要的方法之一。本文对日本北海道新Wakkanai站重建项目的城市设计进行了评价。澄清如何应用城市设计原则来保护冬季气候地区是很重要的。因此，一个问题是，在填充开发后的街区是否提供了理想的防雪环境。本文的目的是回答这个问题，并清楚地了解在冬季城市的填充物开发中，减少其周围公共空间的积雪问题（雪堆和吹雪）所需的块图像。利用风洞模拟试验研究了札幌市中心城区中高层建筑填筑开发前后积雪问题的差异。在本次积雪模拟试验中，填筑后街区和街道的积雪问题得到了改善。观察结果的一个主要原因被认为是建筑高度的微小变化减少了街区公共空间的积雪问题。为了在冬季城市中形成理想的空间形象，街区必须由中层建筑组成，并统一建筑的高度。采用统一建筑高度的中高层建筑填充开发，有效地解决了市中心的积雪问题，为冬季城市提供了理想的特殊街区设计。模拟的结果将反映在本项目的车站改造规划和设计中。这个城市设计研究与雪模拟可能提供最先进的方法。

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. 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.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.