以礼泉县2021年国道、县道、乡道景观优化前后的道路绿地为研究对象,采用无人机航测、实地调查及地理信息系统获取道路绿地信息,结合UAV航测生成的DOM,DEM,DSM文件,提取景观特征,提出改造模式,进行景观优化。对优化后的道路绿地抽样分析其物种多样性,通过计算Margalef丰富度指数、Shannon-Wiener多样性指数、Simpson优势度指数、Pielou均匀度指数综合分析多样性特征,提出适用于礼泉县道路绿地系统的发展建议。研究结果表明,1)UAV航测适用于不同景观特征的道路绿地信息采集,在资料收集上具有普适性,道路绿地受道路等级、宽度的影响,景观配置呈现明显差异。礼泉县域内国道绿化景观基础最好,乡道景观基础最差,存在植物种类单一、地域特征缺失、群落结构不丰富、生态效益不佳等缺点。2)基于场地特征提出完善型和改造型景观改造模式,完善型分为局部修改和整体丰富两类,局部修改以“破灰增绿、景观衔接”为设计要点,整体丰富以“添层、加色、补数”为设计要点,改造型以“背景树+观赏灌木+地被”为主要形式。3)景观优化后各等级道路物种多样性提升,整体景观效果显著,对森林城市建设具有一定借鉴意义。

The road green spaces before and after the landscape optimization of national roads,county roads and township roads in Liquan County in 2021 were taken as the research objects.UAV aerial survey,field survey and GIS were used to obtain road green space information,and the DOM,DEM and DSM files generated from UAV aerial survey were combined to extract landscape features,propose transformation patterns and carry out landscape optimization.The species diversity of the optimized road green spaces was sampled and analyzed,and the diversity characteristics were analyzed by calculating the Margalef richness index,Shannon-Wiener diversity index,Simpson dominance index and Pielou evenness index,and recommendations were made for the development of road green space systems in Liquan County.The results of the study show that:1) UAV aerial surveys are suitable for collecting information on road green spaces with different landscape characteristics,and are universal in terms of data collection.Road green spaces are affected by road class and width,and show obvious differences in landscape configuration.The best landscape base of national roads and the worst landscape base of rural roads are found in Liquan County.There are shortcomings such as single plant species,lack of regional characteristics,poor community structure,low ecological benefits,etc.;2) Based on the characteristics of the site,it is proposed to improve the type and transformation of landscape transformation mode.The improvement is divided into two types,namely local modification and overall enrichment.Local modification is based on the design point of "breaking grey and increasing green,landscape articulation";overall enrichment is based on the design point of "adding layers,colors and numbers";the transformation type is based on "background trees+ornamental shrubs+ground cover ";3) The diversity of species on each grade of road is enhanced after landscape optimization,and the overall landscape effect is remarkable,which has certain significance for the construction of forest cities.