| For centuries, the wind environment of villages and towns in severe cold regions has long been a significant factor influencing the villagers’ outdoor comfort in winter. With the expansion of urbanization as well as development of technology and science, the outdoor comfort rather than the indoor one has gradually aroused more public concern, and greenings, as an effective means to improve outdoor wind environment, has gained more and more attention. However, currently, there is still a lack of scientific and systematic research on windproof effect of greenings, whether in terms of evaluation index, planning awareness or forecasting tools; furthermore, relevant research towards a specific region, climate and season is also very scarce. In view of the above circumstances, this paper carried out the following research:To start with, a series of fundamental investigations on the existing status of wind environment and greenings has been conducted among villages and towns in severe cold regions, by means of questionnaire survey, field measurement and literature review; based on which, it went on to illustrate the influencing mechanism and evaluation criteria of greenings’ windproof effects, thus preparing a solid foundation for the following research.Secondly, with the application of ENVI-met, this paper went on to simulate and analyse the windproof effects of four common forms of village greenings(windbreaks, border trees, square landscape and courtyard greening) under various parameter settings(porosity, size, form, interval and wind direction), thus providing references for applying greening for improving wind environment in practice.Finally, based on the common layout modes(determinant, enclosed and scattered modes) of rural residential clusters, the planning methods of greening windproof in response to each layout mode have been come up with through simulation and analyzation; following on from this, the planning methods have been further applied into village and towns through case study. By optimizing and verifying the windproof greening design of a certain town in severe cold regions via simulation, the specific design strategies of windproof greening of villages and towns in severe cold regions in winter have been proposed, upon which further windproof greening design corresponding to specific regions or seasons could be extended. It is found that windproof effects of windbreaks are relatively good with the belt’s length within 100 m to 180 m, the width no less than 14 m, and the height being 10 m. Furthermore, in a certain range, an appropriate increase in belt length and width, as well as in height along the wind direction, will contribute greatly to enhancing the windproof effects. Properly increasing the density of tree branches will achieve a satisfying road wind environment, with 6m as the recommended row spacing. Specifically, the shrubs planting between trees can help to strengthen windproof effects. The wind environment within sqaure is relatively good when the greenery openings are located at the four corners, and this advantage is more obvios when the dominant wind direction is perpendicular to the long side of square. The main greenery within courtyard are shrubs, whose windproof effects are much weaker when compared with that of buidings. The windproof effects shrubs within courtyard are mostly obvious when located at the backyards.With a comprehensive application of simulation, analysation and comparison, the work of this paper laid foundation for assessing and forecasting the windproof effects of village greening in severe cold regions in winter, thus validating the feasibility of the applying numerical simulation into greening planning and design. |
