公路沿线森林景观及可视性分析

Analysis of Forest Landscape and Visibility Along Highway

以浙江省庆元县主要公路沿线森林景观作为研究对象,对其林分现状及可视性进行分析研究。在获取庆元县数字高程模型和主要公路矢量数据的基础上,采用ArcGIS软件进行可视域分析,提取公路沿线可视范围,并结合森林资源数据进行叠加分析。为了对可视区域进行重要性分级,提出"频率-视距"、"垂直视角"2种可视性测度指标,并与"可视频率"和"视距"指标进行比较。叠加分析结果显示,公路沿线可视范围内非林地占31.76%,生态公益林占36.85%,商品林(地)占31.39%。此外,分别从地类、树种结构和龄组方面对可视域内商品林(地)进行统计分析,并结合林分现状提出相应的林分改造建议。可视性分析结果表明,"频率-视距"法明显优于其它3种方法。

The forest landscape along the main highway in Qingyuan County of Zhejiang Province was taken as the research object,and its stand status and visibility were analyzed and studied.On the basis of the digital elevation model and the main highway vector data of Qingyuan County,the visual range along the highway was extracted using ArcGIS software,and using the spatial overlay technology,the current status of the forest stand in the visual field was studied based on the forest resource data.In order to rank the importance of the visual area,two kinds of visibility measure indexes of the"frequency and sight distance"and the wvertical viewing angle"were put forward,and comparison and analysis were carried out with the"visual frequency"and the"sight distance"indexes.The overlay analysis results show that the non-forest land occupied 31.76%,the ecological public welfare forest occupied 36.85%and the commercial forest(land)occupied 31.39%within the visible area along the highway.In addition,statistical analysis of commercial forest(land)in the visible region was carried out from the aspects of land type,tree species structure and age group.And corresponding suggestions for the forest stand improvement were put forward,according to the present situation of stand.The results of visibility analysis show that the"frequency-sight distance"method is superior to the other three methods.