西北干旱区城镇风雪灾害防护林格局及结构优化配置

In arid area of northwest China, shelterbelt construction is the most economical, effective and sustained approach for combating the threats of gale and snow disasters in cities and towns region. However, large-scale afforestation in a big density is impossible duo to the limitations of water and soil resources. Hence, the shelterbelt should be established in a low density based on rational utilization of water and soil resources; simultaneously its effectual protective period should be in leaf dead term. According to such characteristics and requirements, it is necessary and significant to confirm the reasonable pattern and structure optimization allocation of urban shelterbelt for gale and snow disasters. Therefore, based on the sufficient analysis of climate and meteorological data, geographic environment, roughness of buildings, simulation theory of aerodynamics and field observation, we have studies on regulations of snow drift, characteristics and cause mechanism of gale and snow disasters in order to establish reasonable distribution pattern of shelterbelt. In methods of field observation, simulative experiments, and wind tunnel test, the effects on snow drift of different structure and distribution pattern of arbor and shrubbery are analyzed to discuss optimal parameters of shelterbelt. In short, this study provides theoretical basis of urban shelterbelt construction for combating gale and snow disasters in arid area of Northwest China, and fill in the blank of the study on gale and snow disaster alleviation of settlement environment.

我国西北干旱区部分城镇受风雪灾害威胁严重，建立防护林可以说是最经济、最有效和最持久的方法。但由于受水土资源的制约，不可能大面积、大密度的造林，必须在合理利用水土资源的基础上，建立低密度的防护林网（带）体系，同时需要防护林发生功效的时间主要在枯叶期。基于这样的特点和要求，必须确定城镇风雪防灾林的合理布设格局和优化结构配置。为此，在充分分析气候气象资料、地理环境、建筑物粗糙度的基础上，结合空气动力学仿真理论和野外观测，研究当地风雪流的发生发展规律、风雪灾害特点和成灾机制，构建防护林的分布格局。通过野外观测、现场模拟和室内风洞模型试验，研究不同乔灌植被结构和分布格局对风雪流的影响，探讨防护林结构优化配置参数。为西北干旱区城镇风雪灾害防护林建设提供理论依据，填补人居环境风雪灾害减灾理论研究的空白。

我国西北干旱区部分城镇经常受暴风雪灾害威胁，特别是边疆的一些风口地区，愈加严重，造成大量的人员伤亡和经济损失。建立防护林可以说是最经济、最有效和最持久的防灾减灾方法。但由于受水土资源的制约，不可能大面积、大密度的造林，必须在合理利用水土资源的基础上，结合引种栽培试验，建立低密度、稳定的防护林网（带）体系，同时需要防护林发生功效的时间主要在枯叶期。基于这样的特点和需求，课题组以新疆阿勒泰地区的吉木乃县为对象，通过对当地气候气象、地形地貌的系统分析，结合长时间的实地定点观测，掌握了风雪流发生发展规律、风雪灾害特点和成灾机制，明确“诺海”风是造成吉木乃风雪灾害的最重要因素；通过系统的生态调查，基本摸清了区域的植被资源，筛选出适宜于该地栽培的乡土树种和需要引进的植物种类，并进行栽培试验；以我国西北干旱区典型绿洲和荒漠草原区已建的各种乔灌木防护林带为对象，在野外风场观测的基础上，结合室内风洞模型试验结果分析，提出防护林建设的优化模式，并与吉木乃县政府合作对吉木乃县防护林体系进行空间布局与总体规划设计，部分已经得到实施，防护林防雪效果明显，起到了防灾减灾的作用。在项目支持下，课题组发表中文核心期刊论文2篇，授权发明专利3项、实用新型专利3项，投稿学术论文3篇。