Optimization of timber harvest-visual space allocation for forested landscape

随着越来越多的土地在视觉上受到管理活动的影响，公众对环境-包括其美学价值-的关注也在增加。这些关切中最重要的往往是木材采伐的视觉效果。本研究的主要目的是：（1）从三个不同的角度，即期望的视觉特征、消极的和积极的视觉元素，确定林分内视域的视觉质量目标。引入层次分析法（AHP）对影响视觉视域环境建立的各种因素进行评估，克服了在确定视觉特征和要素优先级时的诸多困难。（2）分析了影响中景和背景视距离下视觉吸收能力的主要景观因子。景观特征的描述定义为： 关于我们 采用德尔菲法对各要素、原理和变量进行了定量分析。对上述景观的分析表明，景观的视觉吸收能力受地形、坡度、对比度、距重要位置的距离等因素的影响较大。（3）通过生成透视图，展示拟议的替代木材采伐/道路布局系统，产生森林景观的视觉设计技术。图纸显示如何变化会出现从选定的观察点，并显示景观作为一个网格的扭曲广场或符号代表树，道路，空地，天际线走廊等拟议的图形系统创建准确的透视演示切割单位边界线和其他关键的地标功能。这使得设计师和地块之间可以立即进行互动，快速来回收敛到最佳设计。这些信息对于景观设计师和伐木工程师来说应该是有用的，他们为了规划满足视觉冲击的木材收获而合作。少

Public concern for the environment -including its esthetic values- has increased as more and more land has been visually affected by management activities. Often foremost among these concerns has been the visual effect of timber harvesting. Many timber harvest activities introduce harsh and incongruous visual elements into the landscape.The main points of this research are to:(1)identify visual quality objectives adopted for the viewshed within the forest stand from three different perspectives;desired visual characters, negative and positive visual elements. The AHP-system was introduced to estimate various factors which affected establishment of visual viewshed circumstances and it could overcome many of the difficulties of the priority determination on desired visual characters and elements.(2)analyze predominant landscape factors that affect the visual absorption capability in the middle- and background viewing distances. The description of the landscape characters was defined in t … More erms of the elements, principles and variables by employing the Delphi-method. An analysis of landscapes above showed that the visual absorption capability was much affected by landform, slope, contrast, distance from significant positions, etc.(3)produce visual design techniques of forested landscapes by generating perspective drawings that show proposed alternative timber harvesting/road layout systems. Drawings show how changes would appear from selected viewing points and show landscapes as either a grid of distored squares or by symbols representing tree, roads, clearings, skyline corridors, etc. The proposed graphic system created accurate perspective presentations of cutting unit boundary lines and other key land mark features. This permits immediate interaction between the designer and the plot, with rapid back and forth convergence towards the best design.The information should be useful to landscape architects and logging engineers teamed for the purpose of planning timber harvests that meet visual impact. Less